NASA

Contractor Report 174710

USAAVSCOM

Technical Report 85-F-l

JNASA-CE-17471Q) EEVIEW AND C8ITICAL N86-24991

ANALYSIS: BOLLING-ELEHEilT EEAEING S FOE

SYSTEH LIFE AHD E SUABILITY Final Report

(Ir»ia (Arthur S,) Co., Inc.) 234 p Oaclas

flC A11/HF A01 CSCL 131 G3/37 43055

11-

Arthur S. Irwin, William J. Anderson, and William J. Derner

Arthur S. Irwin Co., Inc.

Bemus Point, New York 14712

March 1985

Prepared for

Lewis Research Center

Under Contract NAS 3-23520

NASA

National Aeronautics and

Space Administration
CONTENTS

ABSTRACT . 1

INTRODUCTION 1

GENERAL DISCUSSION 5

RECOMMENDED SPECIFICATIONS 9

Specification for Ball and CyTindrUal Roller Bearings 9

Specification for Rework, Refurbishment, and Restoration of

Aircraft Engine and Power Transmission Cylindrical Roller

and Ball Bearings 24

BEARING DATA AND LIFE ANALYSIS 37

RECOMMENDATIONS 40

APPENDICES

A - ATTENDANCE LIST, FIRST INDUSTRY COORDINATION MEETING ... . 61

B - WRITTEN COMMENTS ON FIRST INDUSTRY COORDINATION MEETING . . 63

C - ATTENDANCE LIST, SECOND INDUSTRY COORDINATION MEETING. . . 159

D - WRITTEN COMMENTS ON SECOND INDUSTRY COORDINATION MEETING . 161

E - TYPICAL DRAWINGS WITH DATA FORMATS 215
NASA CONTRACTOR REPORT 174710

REVIEW AND CRITICAL ANALYSIS - ROLLING-ELEMENT BEARINGS

FOR SYSTEM LIFE AND RELIABILITY

Arthur S. Irwln, William J. Anderson, and William J. Derner

ABSTRACT

A ba.l 1 and cylindrical roller bearing technical specification which

Incorporates the latest state-of-the-art advancements was prepared with the

fullest cooperation and participation of a broad Industry committee for the

purpose of Improving bearing reliability 1n U.S. Army aircraft. An

examination of current U.S. Army aviation bearing designs and applications,

Including life analyses, was made 1n preparing the specification. A bearing

restoration and refurbishment specification was also prepared, with the goal

of Improving bearing availability.

INTRODUCTION

The work reported herein was conducted 1n an effort to Improve both the

reliability and the availability of ball and cylindrical roller bearings

used 1n U.S. Army aircraft. To accomplish these goals (Improved reliability

and availability), two specifications were prepared under the cognizance of

the NASA Lewis Research Center Bearing, Gearing, and Transmission Section.

The latter group had been requested by the U.S. Army Troop Support and

Aviation Materiel Readiness Command (TSARCOM) through the U.S. Army Aviation

Systems Research and Development Command to review and critically analyze

rolling-element bearings being utilized throughout U.S. Army Aviation.

To improve rolling-element bearing reliability , a technical

specification Incorporating the latest state-of-the-art advancements was

prepared. An examination of current U.S. Army aviation bearing designs and

applications was made; this Included life analyses of a large group of

representative bearings. To achieve the broadest perspective and range of

viewpoints, a committee made up of representatives of the helicopter

industry, the bearing Industry (who supply bearings to the U.S. Army

Aviation), and aircraft and aircraft engine manufacturers was formed to

review, modify, and recommend the final ball and cylindrica l roller bearing

specification to TSARCOM.

To improve bearing availabilit y (and aircraft readiness), a bearing

restoration and refurbishment specification was prepared. Bearing

restoration refers to the regrinding of used bearings to new bearing

tolerances, includin g the replacement of the rolling elements. Bearing

refurbishment refers to bearings which are cleaned, Inspected, and fitted

with new rolling elements. Previous work on bearing refurbishment and
restoration performed by NASA and the U.S. Army Research and Development

Command was reviewed (ref. 1). As with the technical specification, the

full participation of the Industry committee was solicited and received.

This program was conceived on a relatively simple premise: Improving the

life and reliability of any component part will Increase the readiness of

the assembly. In addition, reducing the scatter 1n t1me-to-fa1lure data can

make possible more realistic and effective prediction of replacement needs

for that component, specifically bearings.

The use of rolling-element bearings over many years 1n a large variety

of rotating and oscillating applications provides the following advantages:

1. Predicted and actual life and scatter data, conventionally

presented 1n acceptable, statistically compatible form. For example,

bearing lives are universally displayed 1n the form of Welbull plots, which

are based on the relationship:

In In 1/S = e In L/A

S = probability of survival

L = life 1n millions of revolutions

A = characteristic life

e = dispersion exponent (slope of Welbull plot)

Mission and utilization Integrate to service life, Interrupted but not

terminated at overhaul. Characteristic life and dispersion data are

available from test and service experience.

2. Life Increases available now. Through the use of Improved

technology, ball and roller bearing lives and reliabilities have Increased

dramatically over the last forty years. A major factor contributing to this

progress has been the Instigation of technologically sophisticated efforts

mounted and supported by governmental agencies and their contractors. Most

programs have been focused on the rapidly Increasing requirements of

aircraft jet engines. Therefore, the first points of application of the new

bearing technology have been 1n jet engines, specifically 1n those bearings

which support the main shaft turbine-compressor rotors.

Starting 1n the early 1940's new developments 1n the making of bearing

steels started coming on-stream, as shown 1n figure 1. These developments

were triggered by proposal and acceptance of a comprehensive material

specification, 1n this case, for AMS 6440 and AISI 52100 steel (A, fig. 1).

About 1941, new heat treatment equipment became available which Incorporated

Improved temperature controls and recorders. The use of neutral atmospheres

during heat treatment practically eliminated surface decarburlzatlon (B,

fig. i).

As requirements grew, facility expansions budgeted Installation of

larger electric arc furnaces producing larger billets. Reducing larger

billets to size for tubing or Individual forglngs refines grain and breaks
down the size of Inclusions and segregation. This trend toward larger

billets has continued, applied to various melting and remeltlng processes

(C, fig. 1).

Major advances 1n melting practice evolved over a period covering 1952

to the early 1970's: About 1952, Introduction of Immersion thermocouples

permitted better control of steel melting (D, fig. 1). Some significant

manufacturing process changes were made 1n the 1950's. One such change

which Improved bearing 1dent1c1ty 1s shoegrlndlng (E, fig. 1). In the case

of at least one ball bearing manufacturer, ball bearing races previously

were ground on equipment which chucked the rings 1n a head which oscillated

about a perpendicular axis, thus, by generation, determining the geometric

center of the race. Race eccentricity and wobble (face runout) became

functions of the condition of the chucking surfaces, and equipment wear and

dirt produced Increasing bearing Inaccuracies.

This arrangement was superceded by equipment 1n which the parts are

supported by shoes contacting the cylindrical outside diameters of the

bearing rings. They are pulled Into the shoes and rotated by a magnetic

plate turning about a center slightly offset from the center of the rings as

fixed by the shoes. With this concept, 1t 1s practically Impossible to

grind eccentricity and face runout Into the parts, and the transverse rad11

of the races, controlled by the grinding wheel dresser, are more consistent.

Vacuum melting reduces the quanltlty and alters the type of Inclusions

and trace elements present 1n the steel, as well as releasing entrapped

gases. When vacuum Induction melted (VIM) electrodes are vacuum arc (CEVM

or VAR) remelted, the resulting material (VIM-VAR) 1s cleaner and more

segregation-free than that produced by VIM alone (F, fig. 1). Also,

nondestructive testing, using eddy current and ultrasonic methods, was

applied to billets, bars, and tubing (G, fig. 1). In this time period,

vacuum degassing of molten steel 1n the ladle drastically reduced oxide type

Inclusions, even 1n standard bearing material (H, fig. 1).

Moving along Into the 1960's, we find argon atmosphere protection of the

molten steel during teeming (I, fig. 1).

Prior to the 1950's as-ground races were hand polished to Improve finish

and appearance. Overly-aggressive polishing could create a thin layer of

plastically displaced or smeared material which was softer and therefore

more prone to fatigue failure. This manual process was replaced by

mechanized honing 1n which all parts are smoothed 1n a more uniform manner

(J, fig. 1). These and similar developments led to Improved product

consistency, permitting quality control by process controls and audits and

reducing human element variability (K, fig. 1).

Based on experience gained with higher temperature bearing applications,

bearing designs trended toward Increased Internal clearances to reduce the

possibility of abusive Internal loading, such as by excessive radial or

axial preloading distortion, and cage designs were modified to accomodate

more precession of the rolling elements, such as promoted by misalignment.

Although laboratory life-testing reflected the trend toward Increased

lives even before 1959, 1t was 1n 1968 that ball bearing catalogs were

changed to triple calculated LIQ lives (fig. 1).
The Interdependent, stepping-stone progression, with each Improvement

clarifying a cause-and-effect relationship, finally reduced failures due to

gross material defects or geometric variations, permitting Identification of

different mechanisms of bearing deterioration and study of the causes of

these Initiatory failure modes. As a "state-of-the-art" report, under the

auspices of the ASME, a design guide was made available 1n 1971, permitting

refined life calculations Incorporating the effects of some of the variables

listed previously (ref. 2). The life calculation refinements are Invoked as

a series of factors reflecting material composition, melting practice, heat

treatment, hardness, lubrication (Including elastohydrodynamlc effects),

speed of operation, and mounting misalignment.

In 1979 NASA summarized the chronological Increase 1n relative bearing

life over the period with which we are concerned for aircraft turbine engine

bearings (ref. 3). This progression 1s also shown 1n figure 1 for premium

material. The factors accredited for the life Increases Indicated are

defined as "NASA Applied Technology" and listed as:

Race and Ball Hardness

Surface Finish

Design

Lubrication

Material

Fiber Orientation

The potential for lives as high as 100 times the AFBMA rated lives was

recognized (ref. 4).

3. Failure modes Identifiable and predictable from computerized

analysis. The first use of digital computers for the analysis of bearings,

1n 1959, can be credited to A. B. Jones (ref. 5). Improving on a tedious

tabular method, this program predicted ball motion based on a hypothesis

concerning kinematic behavior. Progressively this relatively simple concept

was expanded by Jones (ref. 6) and others to Include gyroscopic moments as

well as lubricant effects Including pressure and temperature dependent

viscosity factors. Around 1966 a cylindrical roller bearing analysis

appeared, followed by separate competitive refinements which are still being

pursued. Some of the more recent analyses and resulting computer programs

are given 1n refs. 7 to 12. These computer programs may be used for various

purposes, from Initial bearing selection to post-mortems. Since they

recognize the significance of design, metallurgy, and metrology, as well as

speeds, loads, and lubrication, they serve well to critique many facets of

bearing applications and permit optimization thereof.

For example, the ratio of lubricant film thickness to surface roughness

1s critical to life, up to some value. Above this value, Increasing the

ratio does not help; life 1s then a function of some other factor, such as

material properties. If the ratio of film thickness to surface roughness 1s

marginal, a need to reduce bearing and/or lubricant temperature 1s
Indicated. This Increases oil viscosity and thereby Increases oil film

thickness. If 1t 1s Impractical to reduce temperatures, Improving race and

rolling-element finishes may raise the ratio out of a critical range.

Improvements 1n surface finish were Investigated as a means for life

Improvement of some of the critical bearings for which life analyses are

reported herein. The Specification for Ball and Cylindrical Roller Bearings

lists, under Drawing Requirements, the data required as Inputs to the

computer to generate Information on such critical criteria.

4. Basic material quality monitored by accepted sophisticated

procedures.

5. Manufacturing controls 1n place, Including quality data acquisition

and retention, traceablHty, and permanent product Identification.

6. Life test data available on effect of parts replacement from

relnspected and reworked stocks.

Thus 1t can be seen, as reflected 1n figure 1, that dramatic

Improvements 1n rolling-element bearing technology have been Instituted over

the past four decades. Anything less than full Implementation of this

bearing technology 1n critical applications such as U.S. Army aircraft would

seem to be remiss.

The authors wish to express their gratitude to TSARCOM for their

sponsorship of the program, and to acknowledge the valuable support and

Insights provided by Messrs. Harold H. Coe and Erwln V. Zaretsky of the

Bearing, Gearing, and Transmission Section, NASA Lewis Research Center, Mr.

Gilbert.J. Weden of the Propulsion Laboratory, AARTL, and Mr. Martin Joseph,

TSARCOM. We further wish to thank those Individuals and organizations who

contributed and participated 1n this work.

GENERAL DISCUSSION

The Arthur S. Irwln Co. was under contract with the NASA Lewis Research

Center under sponsorship of the U.S. Army Troop Support and Aviation

Materiel Readiness Command (TSARCOM) to Improve both the reliability and the

availability of ball and cylindrical roller bearings used 1n U.S. Army

aircraft. To accomplish this, the following work was performed 1n

accordance with the contractual statement of work:

A. An analysis of designs and applications of certain ball and roller

bearings 1n current usage 1n Army helicopters, Including those 1n critical

supply.

B. A life and performance analysis with recommendations for possible

redesign of the bearings, Incorporating the newest rolling-element bearing

technology.

C. Development of a rolling-element bearing technical specification

(Specification for Ball and Cylindrical Bearings) specifically oriented to

the requirements of the U.S. Army Aviation Systems Command. This

specification Incorporates currently approved design and Indicates material,

manufacturing, and other technology which would Improve life, reliability,

and/or performance of the bearings.
0. Preparation of a rolling-element bearing refurbishment and

restoration technical specification, specifically oriented to the

requirements of the U.S. Army Aviation Systems Command.

These specifications are 1n a form which assists Army purchasing

personnel 1n obtaining replacement bearings, some of which are currently

purchased only from prime contractors.

Pursuing A above, data packages on some 44 bearings were obtained from

TSARCOM and critical data tabulated. Table 1 presents the results of this

effort. Using these data, an analysis was performed as described 1n the

Bearing Analysis section Included later 1n this report.

In accordance with the Contract Work Statement, these specifications, 1n

their progressive drafts from first to final, were coordinated and reviewed

with the aerospace bearing Industry who specifically manufacture bearings as

prime contractor or subcontractor for the Army Aviation Systems Command,

helicopter manufacturers, and the aircraft and aircraft engine manufacturers

who manufacture aircraft and/or aircraft engines for the U.S. Army.

In addition to transmlttal of material by mall, two meetings of the

representatives were held, followed by submlttal of written comments.

Appendix A lists attendees and appendix B lists comments received from the

First Industry Coordination Meeting. Appendix C lists attendees and

appendix D lists comments received from the Second Industry Coordination

Meeting.

From the first Industry Coordination Meeting, there was unanimous

agreement among the Industry representatives that the prime contractors and

first level subcontractors must play a part 1n determining the

specifications and enforcement procedures to be applied using their data 1n

current use or as developed.

Industry representatives saw no obstacles to making such data available

and strongly recommended continuing use of the prime contractor's

specifications, as well as vendor approval/quality control and drawing

control procedures.

The position taken by the Industry representatives was recognized and

adopted for this project even though 1t differed from the previous program

Intention. Basically and briefly, their position was that the prime

contractors should continue to provide the main channels for selection,

direction, and surveillance of the manufacturers and vendors of the

bearings, and this was extended to Include those engaged 1n bearing rework.

The program activity was then and therefore shifted from that of

creating a comprehensive specification to replace the systems of

communication and control existing between the prime contractors and their

vendors to specifications which take advantage of the existing channels for

flow of technical and contractual information, as well as surveillance and

control. Authority for application or delegation of enforcement of

requirements has been extended to Include cognizant government agencies.

Since these systems have developed over some years, the various prime

contractor/vendor working arrangements have become unique and diverse.
Finding common ground required, 1n addition to the second Industry

Coordination Meeting, progressive revisions of the specifications.

After this series of revisions, the specifications were finalized by

TSARCOM. In the preparation of these specifications, present prime

contractor practices, drawings, specifications, and procedures were

referenced. However, these specifications permit the Identification of the

characteristics to be upgraded to achieve the performance Improvements

Indicated earlier 1n this report.

Review of prime contractors' bearing drawings revealed wide diversity

and even Inadequacy 1n defining requirements 1n bearing geometry, metrology,

and applicable specifications. In most cases, bearings could not be quoted

or manufactured from prime contractors' drawings alone. Our specification

lists the characteristics needed and the specifications to be referenced by

public or prime contractors' designations. The only exceptions to complete

Information needed by a vendor to permit quoting, producing, and shipping

bearings deal with packaging requirements, which are usually covered 1n the

Purchase Orders since they may vary for Identical bearings from .order to

order. In addition, since bearing technology Includes analytical

evaluations, data required for such analyses are Included 1n the drawing

requirements listed 1n the specification. The technical Specification for

Ball and Cylindrical Roller Bearings 1s Included 1n the Recommended

Specifications section.

To demonstrate the use of this section of the specification, a drawing

format was constructed and data from four General Electric Co. drawings were

transferred to this format. While most of the data requirements were

thereby satisfied, some could not be translated from the GE drawings as

presently prepared. These are Included herewith as appendix E.

Practically all the requirements of the technical Specification for Ball

and Cylindrical Roller Bearings apply to bearings processed under the

specification "Rework, Refurbishment, and Restoration of Aircraft Engine and

Power Transmission Cylindrical Roller and Ball Bearings," which 1s Included

1n the Recommended Specifications section.

In the Industry Coordination Meeting on 24 January 1983, Dr. James F.

D111 (AFWAL/POSL) presented Information on activities of the Tr1-Serv1ce

Committee on Bearing Rework. From their material, three documents were

adopted which pertain to our proposed Rework, Refurbishment, and Restoration

processing: MIL-B-58105, NAVAIR 01-1A-503, and NAVAIR 02-1-517. Again

Industry representatives recommended continuing use of prime contractor's

specifications, subcontractor approval, and quality assurance procedures,

Including drawing controls. In our specification, authority for application

or delegation of enforcement of requirements, or portions thereof, has been

extended to Include cognizant government agencies.

This specification addresses four progressive process provinces or

levels by which bearings may be returned to operational status:

Level I. - Processing bearings Involves Inspecting a used bearing,

checking/comparing 1t to new bearing requirements. This process Involves:
a. Demagnetization

b. Cleaning

c. Nondestructive testing

d. Visual/microscopic Inspection

e. Minor repair: buffing and polishing of Inactive and active

surfaces, stoning of nicks and gouges 1n corner rad11

f. Dimensional Inspection

g. Reassembly (to Include retainer rlvettlng or snap-In retention)

h. Dynamic testing (1f required): rotation of bearing rings to permit

evaluation of noise level, torque characteristics, and/or similar

functional parameters

1. Lubrication/preservation - as covered 1n the purchase order

Level II. - Refurbishment of bearings 1s rework of bearings that goes

beyond the scope of Level I Processing. This encompasses all of the

operations of Processing plus one or more of the following:

a. Replace rolling elements

b. Rework/replace retainers

c. Interchange of used components and/or substitution of new

components to create a different assembly Identity

d. Grinding and/or plating of mounting surfaces as necessary to return

to original drawing dimensions

e. Honing (superf1n1sh1ng) of raceways (not to exceed .0003 Inches

total metal removal per surface)

Level III. - Restoration of bearings Involves the removal of material by

a grinding operation. This term encompasses all of the operations of Level

I Processing and Level II Refurbishment plus one or more of the following:

a. Grinding of raceways - up to .003 Inches per side

b. Installation of oversize rolling elements

c. Installation of original or replacement retainer when required

Level IV. - Remanufacturlng of bearings Involves rework of bearings

where new components beyond the rolling elements are manufactured. This

term encompasses all of the operations of processing and may Involve those

of either refurbishing or regrlndlng on the old parts which are reused and

one or more of the following:
a. Manufacturing of a new raceway

b. Manufacturing of a new retainer

After a series of revisions to Incorporate suggested Improvements, this

specification was finalized by TSARCOM.

RECOMMENDED SPECIFICATIONS

Specification for Ball and Cylindrical Roller Bearings

1. Scope: This specification covers the requirements for the qualification

and procurement of gas turbine engine malnshaft and propulsion power train

rolling-element bearings. At the discretion of the cognizant military

authority, the specification may also be applied to those bearings In

critical supply.

2. Applicable Documents, when and as referenced 1n applicable drawings and

other control documents: Use latest versions 1n effect at date of contract.

2.1. Specifications

2.1.1. Specifications specifically referenced 1n body of this

Specification for Ball and Cylindrical Roller Bearings

AMS-2251 Tolerances, Low Alloy Steel Bars

AMS-2253 Tolerances, Carbon and Alloy Steel Tubing

AMS-2259 Chemical Check Analysis Limits

AMS-2300 Premium Aircraft - Quality Steel, Cleanliness, Magnetic

Particle Inspection Procedure

AMS-2310 Qualification Sampling of Steels, Transverse Tensile

Properties

AMS-2350 Standards and Test Methods

AMS-2375 Control of Forglngs - First Article Inspection

AMS-2410 Plating-Silver, Nickel Strike, High Bake

AMS-2412 Plating-Silver, Copper Strike, Low Bake

AMS-2808 Identification, Forglngs

AMS-4616 Bars, Forglngs, and Tubing

AMS-5749 VIM-VAR 86-42

AMS-6265 VIM-VAR AISI 9310 (carbuMzed)

AMS-6276 Steel Balls, Forglngs, and Tubing (8620)
AMS-6414

AMS-6415

AMS-6419

AMS-6444

AMS-6490

AMS-6491

ASTM A 535

2.1.2.

listed 1n 2.1.1

AMS-2404

AMS-2418

AHS-2430

AMS-2526

AMS-6275

AMS-7225

AMS-7226

MIl-B-197

MIL-C-11796

MIL-H-6875

MIL-I-6866

MIL-I-6868

MIL-I-45208

MIL-L-7808

MIL-L-23699

MIL-Q-9858

QQ-C-320

Bars, Forglngs, and Tubing

Bars, Forglngs, and Tubing

Bars, Forglngs, and Tubing

CEVM AISI 52100 Bars, Forglngs, and Tubing

Bars, Forglngs, and Tubing

VIM-VAR AISI M-50

Specifications for Special Quality Ball and Roller

Bearing Steel

Supportive Specifications referenced 1n those specifications

Plating-Nickel Electroless

Plating Copper

Shot Peenlng

Coating, Thin Lubricating Film, Molybdenum D1sulf1de

Impingement Applied

Steel Balls, Forglngs, and Tubing - .4Cr, .45N1, .12Mo,

.00038 (.15-.20C)

Rivets - Steel, Carbon

Steel - Austen1t1c, Corrosion Resistant (18Cr, 9N1)

Bearings, Antifriction, Associated Parts and

Subassemblles, Preparation for Delivery of

Corrosion Preventive Compound, Petroleum, Hot Application

Heat Treatment of Steels (Aircraft Practice), Process for

Inspection, Penetrant Method of

Inspection Process, Magnetic Particle

Inspection System Requirements

Lubricating 011, Aircraft, Turbine Engine, Synthetic Base

NATO code Number 0-148

Lubricating 011, Aircraft Turbine Engine Synthetic Base

Quality Program Requirements

Federal Specification Chromium Plating (Electro-deposited)

10
AMCP-706-203 Engineering Design Handbook - Helicopter Engineering Part

Three - Quality Assurance

2.2. Standards

2.2.1. Standards specifically referenced 1n body of the

Specification for Ball and Cylindrical Roller Bearings

ASTM A 604 Macroetch Testing of Consumable Electrode Vacuum Arc

Remelted Steel Bars and Billets

ASTM B 350 Standard Methods for Chemical Analysis of Carbon Steel,

Low Alloy Steel, Silicon Electrical Steel, Ingot, Ingot

Iron, and Wrought Iron

ASTM B 584 Standard Specification for Copper Alloy Sand Castings for

General Applications

ASTM E 18 Tests for Rockwell Hardness and Rockwell Superficial

Hardness of Metallic Materials

ASTM E 45 Inclusion Ratings - Jernkontoret Charts

ASTM E 59 Sampling Steel and Iron for Determination of Chemical

Composition

ASTM E 112 Standard Methods for Estimating the Avg. Gr. Sz. of Metals

ASTM E 588-76 Detection of Forge Inclusions 1n Bearing Quality Steel by

the Ultrasonic Method

ANSI B 46.1 Surface Texture (Surface Roughness, Wavlness, and Lay)

ANSI Y 14.5 Dimensioning and Tolerandng for Engineering Drawings

MIL-STD-045662 TraceabHUy to NBS Standards

MIL-STD-143 Standards and Specifications, Order of Precedence for the

Selection of

MIL-STD-1520 Corrective Action and Disposition System for

Nonconformlng Material

MIL-STD-1535 Supplier Quality Assurance Program Requirements

MIL-STD-271 Nondestructive Testing Requirements for Metals

MIL-STD-880 Engineering Drawing Practices

MIL-I-45208 Inspection System Requirements

MIL-I-6868 Inspection Process, Magnetic Particle

MIL-H-6875 Heat Treatment of Steels (Aircraft Practice) Process for

11
DOO-STD-100 Engineering Drawing Practices

2.2.2. Supportive Standards referenced 1n those standards listed

1n 2.2.1.

MIL-STD-129 Marking for Shipment and Storage

3. Qualification/Certification - Sources for bearing procurement must be

qualified by the original contractor, by dynamic testing, or by quality

audit.

In Heu of testing of the specific bearing procured, qualification may

be based on prior testing of another bearing size of similar material, type,

and family produced by the manufacturer using current processes.

Bearings procured by other than the prime contractor shall be

permanently marked to Indicate name of procurement activity, as well as

other markings required to ensure traceabHlty.

3.1. Requal1f1cat1on Requirements - On those bearings for which a new

facility 1s to be utilized, or for which a significant process or design

change 1s Intended, requallf1cat1on 1s required. The cognizant authority

may conduct the qualification by testing or quality audit, or may delegate

this responsibility.

3.2. Recert1f1cat1on Requirements - On those bearings which have been

out of production for four years or more, recert1f1cat1on of processes and

standards by the original/prime contractor 1s required. As an alternative,

the cognizant government authority may perform the recert1f1cat1on.

4. Inspection - Inspection of assemblies and components shall be conducted

1n accordance with negotiated quality plans which shall Include record

requirements.

4.1. Inspection Details - First article Inspection details shall be

recorded and maintained as a permanent record. Subsequent Inspection

requirements shall be per the quality plan.

5. Rejection - All components and assemblies which are rejected may be

Identified and held for Quality/Material Review Board action. Those

components which may be reworked shall be rerouted at the discretion of the

manufacturer, providing the original drawing requirements are met.

Assemblies may be disassembled and reassembled providing this 1s

accomplished In accordance with the negotiated Quality Control Plan.

6. Change Control - There may be no significant change to the original

design, material, tolerances, basic process, quality control plan, heat

treat, post heat treat, or rework procedures without prior approval of the

original contractor or the cognizant government authority. "Significant" 1s

to be defined by the procurement agency.

6.1. Change Control Approval - Any request for change shall be the

responsibility of the vendor to submit and obtain approval prior to the

Initiation of work on the contract.

12
7. Process and Inspection Approval - All process operations and Inspection

procedures will be evaluated and confirmed by the original equipment

manufacturer or the cognizant government authority or his delegated

representative to ensure compliance with currently accepted aerospace

Industry standards. This will Include all destructive and nondestructive

methods and Quality Control Plans and Inspection methods.

7.1. Process and Inspection Changes - These shall be requested and

approval pursued as stated 1n paragraph 6, with the exception that

processing may continue, verbal approval having been granted. It shall be

the responsibility of the vendor to provide documentation 1n each such

Instance.

8. Drawing Requirements - Drawings shall be 1n accordance with DOD-STD-100

and MIL-STD-880 and shall contain the Information listed 1n the following

paragraphs. Where existing drawings are Incomplete, they may be

supplemented to Include the following data: bearing usage(s), qualified

sources, change numbers, bearing Installation, and operating data necessary

for analysis of the bearing as applied, etc. Separate sections may be

utilized to define design and Include process data and details to be covered

by Quality Control requirements.

8.1. General Bearing Requirements, where specified

8.1.1. Type of bearing

8.1.2. Bore

8.1.3. -00

8.1.4. Width

8.1.5. Pitch diameter

8.1.6. AFBMA class

8.1.7. Size and number of rolling elements per row

8.1.8. Number of rows of rolling elements

8.1.9. Description of details for special mounting or removal

procedures such as puller grooves, retention, etc.

8.1.10. Radial clearance (total) and gage load for determining

radial clearance

8.1.11. Diametral clearance for retainer to piloting ring land

8.1.12. Retainer overall width, (max.)

8.1.13. Retainer bore to O.D. concentricity

8.1.14. Retainer land width

8.1.15. Pilot ring locating diameter concentricity to pilot land

13
8.1.16. Rolling element to retainer pocket clearance

8.1.17. Ball or roller drop (max.)

8.1.18. Minimum clearance between rolling element and cage to be

measured with rolling element and cage positioned 1n a simulated operating

position to produce the closest approach between rolling element .and the

cage retention feature

8.1.19. Retainer material condition and hardness

8.1.20. Retainer plating required and thickness per AMS-2412 or

AMS-2410

8.1.21. Surface finish roughness (A-A) rolling contact surfaces

8.1.22. Surface roughness (A-A) for mounting surface

8.1.23. Surface finish roughness (A-A) for retainer pockets and

retainer piloting surfaces

8.1.24. Loblng, wavlness, and chatter tolerances applicable to

bearing bore and outer diameter

8.1.25. Surface treatments or coatings required

8.1.26. Assembly cross-corner dimensions as required

8.1.27. Flushness requirements (where applicable)

8.1.28. End play or end float limits (max.) and gage load for each

play check

8.1.29. Material for rings and rolling elements

AMS 6491 VIM-VAR AISI M-50

AMS 6444 * VIM-VAR AISI 52100

AMS 6276 CEVM AISI 8620 (carburlzed)

AMS 6265 * VIM-VAR AISI 9310 (carburlzed)

AMS 5749 VIM-VAR B6-42 (440-c modified)

* Finalized specification not currently available.

8.1.30. Special heat treatment required to Include details of

mlcrostructure and retained austenlte requirements

8.1.31. Surface hardness, as required, at operating temperatures:

AMS 6491 Re 60 (m1n.)

14
AMS 6444 Re 58 (m1n.)

AMS 5749 Re 60 (m1n.)

8.1.32. Bearing operating temperature range and stabilization

temperature required to ensure against excessive growth of elements or

undesirable transformation products, Including retained austenlte:

Material Retained Austenlte (max.)

AMS 6491 2 percent .

AMS 6444 2 percent

AMS 5749 5 percent

AMS 6276 and AMS 6265 5 percent

8.1.33. Required verification of bearing material procurement,

Inspection, and evaluation requirements to ensure cleanliness, grain

control, and sufficiency of working after the Ingot 1s formed to provide the

documentation for traceablHty. (Paragraph 10)

8.1.34. Identification requirements

8.1.35. Requirements for nltal etch staining to be removed from

specific surfaces, where applicable

8.1.36. Inner ring high point to be Identified, 1f required

8.1.37. Grain orientation angle limit for rings (See 8.3.8.)

8.2. Cylindrical Roller Bearing Requirements - In addition to the

general requirements listed ,1n paragraph 8.1., the following are required

for cylindrical roller bearings, where specified:

8.2.1. Roller roundness

8.2.2. Roller diameter and length, nominal

8.2.3. Roller crown radius to crown drop coordinates

8.2.4. Roller flat length and centrallty

8.2.5. Roller end squareness

8.2.6. Roller corner radius runout with respect to roller

cylindrical section, 1f required

8.2.7. Roller to flange, end clearance

8.2.8. Flange height and layback angle

8.2.9. Roller corner dimensions

15
8.2.10. Roller end finish (A-A)

8.2.11. Cage balance tolerance and balancing speed, 1f required

8.2.12. Diameter and length variation within one roller set

8.2.13. Requirement, 1f any, for roller complement to be retained

1n the cage when removed from Its associated ring

8.3. Ball Bearing Requirements: In addition to the general requirements

listed 1n paragraph 8.1., the following are required for ball bearings where

specified:

8.3.1. Contact angle, unmounted; gage load for measuring

8.3.2. Inner-ring groove radius as a percentage of ball diameter

8.3.3. Outer-ring groove radius as a percentage of ball diameter

8.3.4. Runout of split-ring contact face with respect to the bore

of the split ring, 1f required

8.3.5. Ring groove diameter and tolerance, 1f required

8.3.6. Maximum step at race split

8.3.7. Ball grade and ball complement diameter variation

8.3.8. Ring grain orientation to be substantially parallel to

groove surfaces, 1f required (may be negotiated)

8.3.9. Cage balance limit and balancing speed range; diameter for

locating during balancing, 1f required

8.3.10 Identification required to ensure alignment and load

sharing of matched sets of multi-row bearings

8.3.11. Bearing preload, 1f applicable

8.4. Data for Engineering Reference

8.4.1. Operating spectrum

8.4.1.1. Flight condition

8.4.1.2. Percent time

8.4.1.3. Bearing Speed (r.p.m.)

8.4.1.4. Load - axial

8.4.1.5. Radial

16
8.4.1.6. Temperatures

8.4.1.6.1. Inner race and adjacent mating parts

8.4.1.6.2. Outer race and adjacent mating parts

8.4.1.6.3. Rolling elements

8.4.1.6.4. Lubricant - o1l-1n

8.4.1.6.5. 011-out

8.4.2. Mounted bearing radial clearance

8.4.2.1. At room temperature

8.4.2.2. At operating temperature

8.4.3. Shim angle (or equlv.)

8.4.4. Shim thickness, used when grinding split ball bearing rings

(or equlv.)

8.4.5. Race depths (percent ball d1a.)

8.4.6. Cage pocket detail dimensions

8.4.6.1. Circumferential

8.4.6.2. Axial

8.4.6.3. Radial height, m1n.

8.4.7. Diametral clearance for retainer to non-piloting ring

8.4.8. Cage piloting surfaces effective width

8.4.9. Designated lubricant: If lubricant 1s nonstandard, the

following data 1s required:

8.4.9.1. Pressure viscosity coefficient at 100 °F and

210 °F

8.4.9.2. Density at 60 °F

8.4.9.3. Thermal conductivity

8.4.9.4. Thermal expansion

8.4.10. Notes:

8.4.10.1. Where practical, retainer shall be designed to

permit removal of rolling elements from the rings without cutting or bending

tangs. The rolling elements shall be retained 1n the retainer by a

"snap-In" configuration.

17
8.4.10.2. Rolling elements shall be harder than the rings

by one of two points, Rockwell "C" (1f specified).

9. Inspection Processes - All Inspection methods and processes must be

approved and certified by the prime contractor.

9.1. Inspection Methods and Processes to be approved (as required)

9.1.1. Hardness, heat treatment verification, metallurgical test

results, and austenlte determination

9.1.2. Decarbur1zat1on determination, Including allowable

decarburlzatlon on noncrltlcal surfaces

9.1.3. Grinding burn detection and evaluation

9.1.4. Magnetic particle Inspection

9.1.5. Surface defect examination and evaluation (visual and

fluorescent penetrant)

9.1.6. Ultrasonic Inspection for subsurface defects

9.1.7. Eddy current Inspection

9.1.8. X-ray diffraction Inspection

9.1.9. Surface texture evaluation and control

9.1.10. Plating process control and verification

9.1.11. Coating process control and verification

9.1.12. Peenlng process control and verification

9.1.13. Quality control verification and traceablHty

9.2. Inspection Standards

9.2.1. Standards of acceptance for all Inspection processes to

Include dimensional masters traceable to the National Bureau of Standards or

proved equal 1n control and verification to Industry standards, using

MIL-STD-45662 certification document

10. Material - Rings and Rolling Elements

TYPE: HIGH CARBON, HIGH SPEED, CORROSION RESISTANT AND

CARBURIZING STEELS, VACUUM INDUCTION MELTED AND VACUUM ARC

REMELTED MATERIAL FOR BALL AND ROLLER BEARINGS

10.1. Scope

10.1.1. This specification covers forglngs, forging stock, tubing,

bars, rods, and colls to be used 1n the manufacture of high quality ball and

roller bearings.

18
10.2. Process:

10.2.1. The steel/electrode may be produced employing vacuum

Induction melting process during Initial melting, followed by remeltlng

employing vacuum arc remeltlng (consumable electrode) process. The Initial

electrode may be both melted and cast under vacuum.

10.2.2. For manufacture of bearings 1n this category, the bearing

supplier shall purchase, control, and test raw material to this

specification and provide certification thereto.

10.3. Referenced Specifications: The following documents are Integral

parts of this specification. (Use latest Issue 1n effect at time of

Issuance of procurement contract for each.)

10.3.1. Aerospace Material Specifications:

AMS-2251 Tolerances, Low Alloy Steel Bars

AMS-2253 Tolerances, Carbon and Alloy Steel Tubing

AMS-2259 Chemical Check Analysis Limits

AMS-2300 Premium Aircraft - Quality Steel, Cleanliness, Magnetic

Particle Inspection Procedures

AMS-2310 Qualification Sampling of Steels, Transverse Tensile

Properties

AMS-2350 Standards and Test Methods

AMS-2375 Control of Forglngs - First Article Inspection

AMS-2808 Identification, Forglngs

AMS-4616 Bars, Forglngs, and Tubing

AMS-6414 Bars, Forglngs, and Tubing

AMS-6415 Bars, Forglngs, and Tubing

AMS-6419 Bars, Forglngs, and Tubing

AMS-6444 CEVM AISI 52100 Bars, Forglngs, and Tubing

AMS-6490 Bars, Forglngs, and Tubing

AMS-6491 VIM-VAR AISI M-50

10.3.2. American Society for Testing and Materials

ASTM E 18 Tests for Rockwell Hardness and Rockwell Superficial

Hardness of Metallic Materials

19
ASTM E 59 Sampling Steel and Iron for Determination of Chemical

Composition

ASTM E 112 Standard Methods for Estimating the Avg. Gr. Sz. of Metals

ASTM E 350 Standard Methods for Chemical Analysis of Carbon Steel,

Low-Alloy Steel, Silicon Electrical Steel, Ingot, Ingot

Iron, and Wrought Iron

ASTM E 588-76 Detection of Forge Inclusions 1n Bearing Quality Steel by

the Ultrasonic Method

ASTM A 535 Specifications for Special Quality Ball and Roller Bearing

Steel

ASTM A 604 Macroetch Testing of Consumable Electrode Vacuum Arc

Remelted Steel Bars and Billets

10.3.3. Government Standards

MIL-STD-143 Standards and Specifications, Order of Precedence for the

Selection of

MIL-STD-271 Nondestructive Testing Requirements for Metals

MIL-H-6875 Heat Treatment of Steels (Aircraft Practice), Process for

MIL-I-6868 Inspection Process, Magnetic Particle

MIL-I-45208 Inspection System Requirements

ANSI B46.1 Surface Texture (Surface Roughness, Wavlness, and Lay)

10.4 Chemical Composition

10.4.1. The steel shall conform to the requirements as established

1n applicable AMS standards

10.4.2. A chemical analysis shall be obtained and reported for the

master heat for all elements listed 1n Paragraph 10.4.1. In addition to the

heat analysis, each remelt Ingot shall be analyzed for carbon and manganese.

10.4.3. Check analysis may be made by the purchaser 1n accordance

with the latest revision of ASTM 59 and AMS 2259 with the exception that

check limits for carbon content shall be controlled to assure desired

hardenabmty (-.01 to +.03).

10.5. Form and Condition - To perform Immersion ultrasonic tests, the

M-50, 52100, and BG-42 materials shall be furnished 1n annealed and

centerless ground or turned condition and the carburlzlng grades 1n

normalized or tempered condition, with a maximum hardness suitable for

finishing to 125 m1cro1nch RMS maximum.

20
10.6. Quality Tests

10.6.1. Material shall be uniform 1n quality and condition, clean,

sound, and free from foreign materials and from surface and Internal defects

detrimental to fabrication or to performance of parts. The material shall

have uniform macrostructure and grain flow.

10.6.2. The manufacturer shall be held responsible for the quality

of the material being furnished and shall make the necessary tests to ensure

this quality.

10.6.3. Magnetic Particle Stepdown Test (1f not ultrasonlcally

tested)

10.6.3.1. Specimens shall be taken from 4 Inch square

billets representing the top and bottom of each Ingot.

10.6.3.2. Specimens shall be Inspected 1n accordance with

AMS 2300.

10.6.3.3. No additional ultrasonic test required

10.6.4. Macroetch

10.6.4.1. Billet Inspection - Transverse disc sections

shall be cut from both ends of all billets or bars prior to rolling Into

bars or extrusion Into tubes. The samples shall be etched 1n accordance

with ASTM A 604 1n hot hydrochloric add and water (1:1) at 160 to 180 °F

for sufficient time to develop a well-defined macrostructure.

10.6.4.1.1. Samples shall show no Imperfection

such as pipes, cracks, porosity, segregation, and Inclusion detrimental to

fabrication or performance.

10.6.4.1.2. Samples shall exhibit

macrostructure equal to or better than the following macrophotographs of

ASTM A 604

Class Condition Severity

1 Freckles A

2 White Spots A

3 Radial Segregation B

4 Ring Pattern C

10.6.4.2. Finished Product Inspection

10.6.4.2.1. Transverse disc sections shall be

removed from both ends of bars and tubes and etched 1n accordance with

ASTM A 604 1n hot hydrochloric add and water (1:1) at 160 to 180 °F for

sufficient time to develop a well-defined macrostructure.

21
10.6.4.2.2. Samples shall show freedom from

pipes, porosity, Inclusions, decarburlzatlon, seams, Internal, or external

defects.

10.6.4.2.3. If samples are representative of

material prior to centerless grind/turn operation, any surface defects,

seams, or decarburlzatlon must be within the stock removal zone.

10.6.4.2.4. Samples shall exhibit no evidence

of segregation when examined visually (no magnification).

10.6.5. Grain Size - The grain size shall be 8 or finer with

occasional grains as large as 5 permissible when determined 1n accordance

with procedures prescribed 1n ASTM E 112.

10.6.6. Inclusion Content - Radial specimens, approximately 0.28

sq. 1n. 1n surface area shall be taken midway between center and surface of

transverse discs removed from billet/bar representative of the top and

bottom of each Ingot. The hardened specimens shall be polished on a face

longitudinal to the direction of rolling and rated for Inclusion content 1n

accordance with the Jernkontoret Chart, Method 0 Plate III of ASTM E 45. No

specimen shall exceed the following limits:

Inclusion Rating

Type

Thin

Heavy

A

1.5

0

B

1.0

0

C

1.0

0

D

1.5

0

10.6.6.1 For types A, B, and C thin combined, there

shall be not more than three fields, No. 1.5A or No. l.OB and C types, and

not more than five other lower rateable A type thin fields per specimen.

For types A, B, C, and D heavy, there shall be not more than 1 1n each

category.

10.6.6.2. A rateable field 1s defined as one which has a

type A, B, C, or D Inclusion rating of at least No. 1.0 thin or heavy 1n

accordance with the Jernkontoret Chart, Plate III ASTM E 45.

10.6.7. Reponse to Heat.Treatment - Specimens shall demonstrate

hardness within the specified limits when tested for hardenablHty or heat

treatment response as specified.

10.6.8. Decarburlzatlon - Decarburlzatlon shall be within limits

specified 1n applicable specifications such as AMS 6491.

10.6.9. Ultrasonic Inspection

10.6.9.1. Bars and forging rounds shall be Immersion

ultrasonic tested 1n accordance with approved procedures.

22
10.6.9.2. The ultrasonic test shall cover both shear and

longitudinal directions and be calibrated to reject the following defects:

Direction Size and Type

Shear Wave .004 deep x .050 long shot

Longitudinal Wave 50 percent of 2/64 1n. flat bottomed

hole Depth: half of section dim.

These criteria are sensitive to bar size; calibration and test details to be

negotiated between material vendor, bearing manufacturer, prime contractor,

and government representatives.

10.7. Surface Defects - Bars or rods shall be of surface condition or

centerless ground to a finish commensurate with ultrasonic testing

requirements.

10.8. Tolerances - Unless otherwise specified, tolerances shall conform

to the following:

10.8.1. Bars: Latest Issue of AMS 2251, as applicable

10.8.2. Tubing: Latest Issue of AMS 2253, as applicable to

Mechanical Type

10.9. Rejection - Material not conforming to this specification or to

authorized modifications will be subject to rejection.

10.10. Inspection

10.10.1 The bearing supplier shall be responsible for assuring

that all tests and Inspections promulgated 1n this specification are

performed.

10.10.2. Material accepted by the original purchaser, which

subsequently reveals defects not detected during Inspection, 1s subject to

rejection.

10.10.3. Test methods to be followed shall be 1n conformance with

ASTM Issue 1n AMS 2350 when ASTM methods are specified.

10.11 Material Certification

10.11.1. The bearing supplier shall require and maintain complete

certification for all raw material.

10.11.2. The material certification shall contain the following

Information:

1. Mill source

2. Purchase order number

3. Heat numbers

23
4. Quantity per heat

5. Material specification number (Inc. revision number)

6. Size

7. Numerical results of specified tests

8. When material capability requirements are specified, vendor must

certify either actual test data or certify capability

9. Chemical analysis

10. Condition of material supplied, I.e., hot rolled, hot rolled

annealed, cold drawn, etc.

11. Results of MPI tests

12. Results of nonmetalUc Inclusion ratings

13. Results of ultrasonic testing

14. Results of test for response to heat treatment

Specification for Rework, Refurbishment, and Restoration of Aircraft Engine

and Power Transmission Cylindrical Roller and Ball Bearings

1. Scope - This specification shall provide for the optimized utilization

of aircraft engine, helicopter main power train transmission, and auxiliary

bearings determined to be critical either by virtue of their performance,

function, or availability.

1.1 Sources - Those bearings to be processed under the provisions of

this specification may be used bearings removed after service, unused

bearings returned from the field, or rejected bearings returned for

relnspectlon and salvage.

2. Applicable Documents - See specification for ball and cylindrical roller

bearings for general specifications, standards, and other supporting

documentation. In addition the following will apply:

MIL-B-58105 Bearing Restoring by Raceway Grinding

NAVAIR 01-1A-503 (TM 55-1500-322-24) US Navy Bearing Manual

NAVAIR 02-1-517 US Navy Standard Maintenance Procedures for Pratt and

Whitney Aircraft Engines

3. Qualification/Certification - Sources for bearing refurbishment and

restoration must be qualified by the original contractor or the cognizant

government agency by dynamic testing or quality audit.

In Heu of testing of the specific bearing being processed,

qualification may be based on prior evaluation of another bearing size of

24
similar material, type, and family produced by the source using continued

unchanged processes.

Refurbished or restored bearings shall be permanently marked to Indicate

name of procurement agency as well as all other markings required to ensure

traceabUHy.

3.1. Requalif1cat1on Requirements - On those bearings for which a new

facility 1s to be utilized, or for which a significant process of design

change 1s Intended, requallf1cat1on 1s required. The cognizant government

authority may conduct the qualification by testing or quality audit, or may

delegate this responsibility.

3.2. Recertlf1cat1on Requirements - For those bearings which have not

been processed for four years or more, recertlf1cat1on of processes and

standards by the original/prime contractor 1s required. As an alternative,

the cognizant government authority may perform the recert1f1cat1on.

4. Process - The refurbishment-restoration process will, 1n general,

proceed 1n accordance with the flow chart shown on the Bearing Processes

Chart.

5. Inspection - Inspection of assemblies and components shall be conducted

1n accordance with negotiated quality plans, which shall Include record

requirements.

5.1. Inspection Details - First article Inspection details shall be

recorded and maintained as a permanent record. Subsequent Inspection

requirements shall be per the quality plan.

6. Rejection - All components and assemblies which are rejected shall be

Identified and held for Quality/Material Review Board action. Those

components which may be reworked shall be rerouted at the discretion of the

rework manufacturer, providing the original drawing requirements are met.

Assemblies may be reworked, dismantled, and reassembled providing this 1s

accomplished 1n accordance with a negotiated quality control plan.

7. Change Control - There may be no change to the original design,

material, tolerances, basic processes, quality control plan, heat treat,

post heat treat, or rework procedures without prior approval of the original

contractor or the cognizant government authority.

7.1. Change Control Approval - Any request for change shall be the

responsibility of the vendor to submit prior to the Initiation of work on

the contract.

8. Process and Inspection Approval - After award of a production contract,

all process operations and inspection procedures will be evaluated and

confirmed by the cognizant government authority or his delegated

representative, to ensure compliance with currently accepted aerospace

industry standards. This will include all destructive and nondestructive

methods and quality control plans and Inspection methods.

8.1. Process and Inspection Changes - These shall be requested and

approval pursued as stated in paragraph 7.

25
8.2. Process and Inspection Deviation Approval - These shall be

requested and approval pursued as stated 1n paragraph 7, with the exception

that processing may continue, verbal approval having been granted. It shall

be the responsibility of the vendor to provide documentation of each such

Instance.

9. Definitions - See Glossary

10. Rework Process - Bearing rework 1s divided Into three categories:

Processing, Refurbishment, and Restoration. These operations will be

conducted as detailed 1n TM 55-1500-322-24, HIL-B-58105 and as further

specified 1n this document. The basic procedure 1s Illustrated 1n the

Bearing Processes Chart.

For disassembly, bearings with nonremovable retainer-roller sets require

removing retainer rivets or permanently distorting retainer web portions.

Bearings with rlvetted retainers may be reassembled by Installing new

rivets, but distorted retainers must be rejected.

10.1. Level I - Processing bearings Involves Inspecting a used bearing,

checking/comparing 1t to new bearing drawing requirements. This process

Involves:

a. Demagnetization

b. Cleaning

c. Nondestructive testing

d. Visual/microscopic Inspection

e. Minor repair: buffing and polishing of Inactive and active

surfaces, stoning of nicks and gouges 1n corner rad11

f. Dimensional Inspection

g. Reassembly (to Include retainer rlvettlng or snap-In retention)

h. Dynamic testing (1f required): rotation of bearing rings to

permit evaluation of noise level, torque characteristics, and/or

similar functional parameters

1. Lubrication/preservation - as covered 1n the purchase order

j. Packaging - as covered 1n the purchase order

10.2. Level II - Refurbishment of bearings 1s rework of bearings that

goes beyond the scope of Processing (per 10.1). This encompasses all of the

operations of Processing plus one or more of the following:

a. Replace rolling elements

b. Rework/replace retainers

26
c. Interchange of used components and/or substitution of new

components to create a different assembly Identity

d. Grinding and/or plating of mounting surfaces as necessary to

return to original drawing dimensions

e. Honing (superf1n1sh1ng) of raceways (not to exceed .0003 Inches

total metal removal per surface)

10.3. Level III - Restoration of bearings Involves the removal of

material by a grinding operation. This term encompasses all of the

operations of Processing (per 10.1) and Refurbishment (per 10.2) plus one or

more of the following operations:

a. Grinding of raceways - up to .003 Inches per side

b. Installation of oversize rolling elements

c. Installation of original or replacement retainer when required

10.4. Level IV - RemanufactuMng of bearings Involves rework of

bearings, where new components beyond the rolling elements are

manufactured. This term encompasses all the operations of processing and

may Involve those of either refurbishing or regrlndlng of the old parts

which are reused and one or more of the following:

a. Manufacturing of a new raceway

b. Manufacturing of a new retainer

10.5. Additional methods or operations may be substituted for those

noted 1n the above TM 55-1500-322-24 or 1n MIL-B-58105 1f approved by the

original contractor or the cognizant government authority.

10.6. Identification - to maintain traceablHty, 1n all cases the

bearing rings and cages will carry permanent marking Including original

Identification as well as the bearing rework contractor, lot, and date of

completion for all successive reworks. For any part, the permissible number

of reworks shall not exceed five.

11. Preservation and Packaging shall be provided 1n accordance with the

original purchase order, unless specified otherwise.

12. Issue and Storage shall be 1n accordance with TM 55-1500-322-24 when the

required qualification has been accomplished. Follow-on lots shall be

released for use 1n accordance with the purchase order.

27
GLOSSARY

AA - Finish: Arithmetic Average - a numerical value of surface finish

obtained by measuring the vertical distance from the mean line of an

Irregular surface to the profile in the same manner as with RMS, adding

these measurements and dividing by the number of measurements

ABEC 1. ABEC 5. ABEC 7. ABEC 9: Annular Bearing Engineers Committee

(AFBMA) designations Indicating degrees of ball bearing precision

Active Surfaces: The areas on the rings, rolling elements, and cage

that engage another surface 1n rolling or sliding contact, as the bearing

rotates

AFBMA: Ant1-Fr1ct1on Bearing Manufacturers Association

Angular-Contact Bearing: A type of ball bearing whose Internal

clearance and ball raceway locations are such as to result 1n a definite

contact angle and predetermined relationship of Inner to outer ring

surfaces, when loaded axlally

ANSI: American National Standards Institute

Antifriction Bearing: A bearing using rolling elements such as balls,

rollers, or needle rollers

AQL: Acceptable Quality Level 1s a value specified for a type or group

of defects characteristic of an Item or product. The specified AQL value

(example - AQL of 0.4) 1s referred to 1n the appropriate sampling plan table

of MIL-STD-105. The number of defects for each AQL 1s then obtained that

will determine whether to accept or reject the lot

Axial Clearance: see End Play

Axial Load (Thrust): Force applied to the bearing 1n line with the

bearing axis

Ball Complement: Size and number of balls used 1n a ball bearing

Bearing Axis: The Imaginary center line about which the outer or Inner

ring will revolve

Bearing Stack: Matched mutlple assembly of two or more bearings

Bore Diameter: Inside diameter of Inner ring

Bore. Outer Ring: Inner diameter of outer ring

Boundary Dimensions: Dimensions for bore, outside diameter, width, and

corner(s)

Burnish: A luster or polish on a surface caused by friction or rubbing

contact

28
Cage (retainer, separator): A device, partially surrounding the rolling

elements and traveling with them, with the purpose of spacing the rolling

elements 1n proper relationship to each other, preventing mutual abrading

Centrifugal: Moving or acting 1n a direction away from a center or axis

of rotation

Clearance. Axial: see End Play

Clearance. Radial: Radial Internal clearance 1s the total diametrical

movement of the undamped ring when the specified radial load 1s reversed

Cone: The Inner ring of a tapered roller bearing

Contact Angle: Angle between plane perpendicular to bearing axis and

line drawn between centers of contact of balls to Inner and outer ring

raceways

Convex: A surface that 1s curved outward 1n the center

Corrosion: A process which destroys the metal by chemical or

electrochemical action and converts it to an oxide, hydroxide, or sulfate

compound

Crack: A break, fracture, fissure, crevice, or separation in the

structure of the part

Critical Defect: A defect that judgment and experience Indicate is

likely to result in hazardous or unsafe conditions for Individuals using,

maintaining, or depending upon the product; or a defect that judgment and

experience indicate is likely to prevent performance of the tactical

function of a major end item such as an aircraft, missile, or space vehicle

Crowned Roller: Having a very large radius profile on both sides of a

straight cylindrical center section to provide a modified line contact with

the raceways

Defect: (discrepancy) Any deviation of a part from specified

requirements

Diametrical Stability: The degree of stability that hardened steel may

have to resist growth or permanent expansion (a function of the amount of

retained austenite)

Duplex Bearing: Single-row ball or tapered roller bearings specially

ground for use in matched sets. They are manufactured with a controlled

relationship of axial location of the inner and outer ring faces. Usually

they are arranged in pairs for mounting face-to-face (DF), back-to-back

(DB), or tandem (DT). When more than two bearings comprise a set, they are

arranged in tandem or in combinations of DT-DB or DT-DF.

Dynamic Balance: That condition in a rotating body reflecting how

closely the mass axes are coincident or the same as the rotational axis

29
Eccentricity (radial runout): Occurs when the center of one circular

surface 1s not coincident (the same) as the center of another surface. Ex:

Nonunlform thickness between the bore and the ball groove of an Inner ring

End Play (Test): The bearing 1s to be lubricated with light oil and one

of Its rings clamped to prevent axial movement. The specified reversing

measuring load 1s applied to the undamped ring so that the resultant

movement of that ring 1s parallel to the bearing axis. The end play 1s the

total movement of the undamped ring when the load 1s applied first 1n one

direction and then the other.

Flaking: A condition of advance surface fatigue where small pieces of

metal are loosened from the base material

Fluting: A form of pitting 1n which pits occur 1n a regular pattern so

as to form transverse grooves or flutes 1n the raceway

Fretting (fret wear, fretting corrosion, false brlnelUng): The rapid

abrasion that occurs at the Interface between contacting, highly loaded

metal surfaces when subjected to vibratory motions of low amplitude, usually

accompanied by the formation of oxides of the abraded metal

Galling: The transfer of material from one surface to another during

sliding .contact

Groove Runout with Reference Side. Inner Ring: see Raceway Runout with

Reference Side, Inner Ring

Groove Runout with Reference Side. Outer Ring: see Raceway Runout with

Reference Side, Outer Ring

Hardness: Resistance of metal to plastically deform, determined by

Indentation

Height of Raceway Shoulder: Distance from bottom of respective raceway

to Inner-ring outer diameter or outer-ring Inner diameter (same as race

depth)

Inclusion: A void, discontinuity, or solid foreign particle 1n the

molecular structure of metal

Inner Race: Raceway of Inner ring

Inner Ring: The Inner component of a bearing

Inside Diameter: Dimension across center of ring bore, may bemused to

express dimension across bore of snap ring, shield, seal, etc.

Inspection: The process of measuring, examining, testing, or otherwise

comparing the unit or product (bearing) with the requirement

Inspection. Quality Conformance (CQI): All examinations and tests

performed for the purpose of determining conformance with specified

requirements

30
Inspection. 100 percent: An Inspection 1n which Specified

characteristics of each bearing are examined or tested to determine

conformance with requirements

Internal Clearance: see Clearance, Radial

Lands: The flat surfaces on either side of the raceway or rings

Land Riding Retainer: A retainer guided by either the Inner-ring or

outer-ring lands

Laps: Discontinuities or Irregularities 1n the material as a result of

heading or forging

Lay: Direction of the predominant surface pattern

Loading Groove (filling slot): Notch 1n raceway to permit assembly of a

maximum number of rolling elements

Loading Groove Bearing: A bearing of maximum capacity type 1n which

there 1s Introduced, by means of a filling slot or loading groove, more

balls or rollers than can be Incorporated 1n a non-filling slot or

Conrad-type bearing

Lot: This term shall mean Inspection lot, a collection of bearings or

kits from which a sample 1s to be drawn and Inspected to determine

conformance with the acceptability criteria.

Lot Size: The lot size 1s the number of bearings 1n a lot.

Ma.lor Defect: A defect, other than critical, that 1s likely to result

1n failure, or to materially reduce the usability of the product for Its

Intended purpose

Martenslte: A phase of steel with a body-centered crystalline structure

characterized by a needle-Uke mlcrostructure

Matching: Inner and outer rings 1n duplex bearing sets that are matched

for face flushness, bore, O.D., and eccentricity, within specified tolerances

Micron: One millionth of a meter, 1 micron equals .00003937 Inches.

Minor Defect: A defect that 1s not likely to materially reduce the

usability of the bearing for Its Intended purpose, or 1s a departure from

established standards having minimal Influence 1n the effective use or

operation of the unit

Nominal: Approximate or rated value

Outside Diameter Squareness with Side (Test): One side of the outer

ring 1s supported on a flat plate of suitable dimensions (with Inner ring

free) and held against a stop located close to the lower corner of the

outside diameter. The Indicator 1s applied directly above the stop close to

the upper corner of the outside diameter. The deviation from the outside

31
diameter squareness with side 1s the difference between the minimum and

maximum reading of the Indicator when rotating the outer ring one revolution.

Parallelism of Sides: The difference between the largest and smallest

width of the bearing rings

Pitch Diameter. Rolling Elements: The diameter of the center line of

the rolling elements

Pitting: Minute removal of material from surfaces through fatigue,

corrosion, or electrical arcing

Plastic Flow: Deformation that permanently remains after removing the

load which caused 1t

Pocket Cage: That portion of cage which 1s shaped to receive the

rolling element

Precision; The degree of agreement of repeated measurements of a

quantity. Compare with accuracy.

Preload: Predetermined Internal thrust (axial) load deliberately

Imposed by design 1n certain duplex bearing sets to provide Increased radial

and/or axial rigidity

Processed Bearing: A bearing that has been used and then cleaned,

Inspected, gaged, tested, and preserved for additional use

Profile: The contour (external outline) of a surface 1n a plane

perpendicular (right angle) to the surface

Profile (measured): A representation of the profile obtained by

Instrumental means

QCL: Quality Characteristics List

Race: same as Raceway

Raceway: The contact path of the rolling element on rings of roller

bearings

Raceway Diameter: Diameter of the Inner- or outer-ring raceway of a

bearing

Raceway. Inner Ring: Roller or ball track or groove 1n the Inner ring

Raceway. Outer Ring: Roller or ball track or groove 1n the outer ring

Raceway Runout, with Reference Side. Inner Ring (Test): Mount bearing

on arbor having a very slight taper (preferably 0.0001 to 0.0002 1n. on the

diameter per Inch of length). Support outer ring 1n horizontal position and

apply Indicator to side of inner ring. The deviation from groove

parallelism with side is the difference between the maximum and the minimum

reading when rotating the arbor one revolution.

32
Raceway Runout, with Reference Side. Outer Ring (Test): Mount bearing

on arbor having a very slight taper (preferably 0.0001 to 0.0002 1n. on the

diameter per Inch of length). Apply a true running weight to the outer

ring. Support arbor 1n a vertical position and apply Indicator to side of

outer ring. The deviation from groove parallelism with side 1s the

difference between the maximum and minimum reading when rotating outer ring

one revolution.

Radial Clearance: see Clearance, Radial

Radial Load; Force applied to the Inner or outer rings perpendicular to

the bearing axis

Radial Runout (Test): Mount bearing on arbor having a very slight taper

(0.0001 to 0.0002 1n. on diameter per Inch of length). Apply Indicator on

center of stationary outer ring. The radial runout 1s the difference

between the maximum and minimum reading when rotating the arbor one

revolution. Corrections should be made for the Inaccuracy of the arbor.

Radial Type Bearing: A rolling-element bearing primarily designed to

support a radial load perpendicular to shaft axis

Random Sampling: Plan for choosing sample units 1n a random or

nonregular pattern for quality Inspection

Rating Life (L-|0): Number of hours at a given speed that 90 percent

of a group of Identical bearings will attain or exceed before the first

Indication of fatigue cracking or spalUng

RBEC 1. RBEC 5: Designations Indicating degrees of roller bearing

precision, Roller Bearing Engineers Committee (AFBMA)

Ref1n1sh: To restore an existing surface finish without removing all

the existing finish

Refurbishment: Refurbishment 1s defined as the process of removing the

rolling elements from used bearings, disassembling, Inspecting, and cleaning

the bearing and replacing the rolling elements with new elements.

Restoration: Restoration is defined as the process of grinding the

raceways of used bearings and replacing the rolling elements with oversized

elements whereby the internal geometry and clearances in the bearing are

maintained.

Retainer: see Cage

Rework: The overall procedure for cleaning, reworking, refurbishing,

restoring, and reissuing of used or rejected bearings

Rockwell Hardness Test: A test for determining the hardness of a

material based on the depth of penetration of a specified penetrator Into

the specimen under specified load conditions

33
Roller: Load carrying rolling element of cylindrical, conical, or

curvilinear contour

Roller Complement: Size and number of rollers 1n a bearing

Roller Diameter: Maximum diameter of straight rollers

Roller Length: Distance between the ends or faces of the roller

Rolling Bearing: A bearing using rolling elements such as balls,

rollers, or needles to reduce friction and to support load

Runout: The amount that one surface lacks of being co-planar with

another surface of the same part

Runout. Radial: see Radial Runout

Sample: A sample consists of one or more parts drawn from a lot, the

parts being selected at random without regard to their quality.

Sampling Plan: A sampling plan Indicates the number of bearings from

each lot which are to be Inspected and the criteria for determining the

acceptability of the lot.

Scratches: Linear abrasions on the surface

Scuffs: A series of small superficial or shallow scratches

Separables: A bearing assembly that may be completely or partially

disassembled without permanently deforming any of Its component parts

Separator: see Cage

Side Runout. Inner Ring (Test): Mount bearing on arbor having a very

slight taper (0.0001 to 0.0002 1n. on diameter per Inch of length). Apply

Indicator against side of Inner ring. The side runout 1s the difference

between the maximum and minimum reading when rotating the arbor one

revolution.

Skew: Slant, twist, nonsymmetrlcal, nonunlform distribution

Smearing or Pickup: Removal of raceway, ball, or cage material due to

skidding contact and its red1spos1t1on at another point 1n the form of a

smear

SpalUng: Actual removal of material from raceway or rolling element

surfaces 1n the form of flakes, resulting 1n cavities - fatigue related

Squareness of P.P./Bore with Face: The squareness (90° angle) of the

face with the outside diameter/bore of a ring

Staking: A method of retaining a bearing by displacing housing material

over the chamfer or of displacing retainer material to contain a rolling

element 1n the pocket

34
Stains: Surface discoloration

Standard: A physical or numerical limit which 1s used as a reference

Statistical: Of, relating to, or dealing with the collection and

analytical Interpretation of numerical data

Superficial: Affecting only the surface of an object

Surface Texture: Repetitive or random deviations from the nominal

surface which form the pattern of the surface. Include roughness, wavlness,

lay, and flaws.

Tandom Duplex Mounting: Assembly of two or more ball bearings mounted

so as to divide the thrust load

Tarnish: A stain on the surface

Temper: To soften hardened steel by reheating at a temperature below

the hardening temperature

Thrust Bearing: A ball or roller bearing with space between rings

oriented perpendicular to the axis of rotation. It 1s primarily Intended to

carry thrust loads.

Used Bearing: A bearing that has seen service and has been subjected to

operating loads

Width. Bearing: The width of the Individual ring and cage parts, or

face of Inner ring to opposite face of the maximum axial envelope dimension,

whichever 1s greater

Width. Inner Ring: Dimension across the Inner ring

Width. Outer Ring: Dimension across the outer ring

35
Carbon Remover Required

Agitated MIL-C-14460 Wash

Agitated Water Rinse

Agitated Water Displacement

Dip MIL-C-11796

Agitated PD 680 Rinse

Agitated MIL-T-81533 Wash _

Refurbishment

See Paragraph 10.2

Restoration

See Paragraph 10.3

Demagnetize

PD 680 Wash

Agitated Hot 011 Dip

Agitated PD 680 Wash

Agitated MIL-T-82533 Dip

Pre-1nspect1on and/or dismantling

See Paragraph 10.1

Buffing

Agitated PD 680 Wash and Hand

Spray Cleaning

Visual Inspection

Dimensional Inspection

Demagnetize

Assembly

Wash 1n agitated dip tank with

MIL-C-15074

Wash 1n Agitated PD 680

Identification

Additional cleaning as required

Preservation

Packaging

BEARING PROCESSES CHART

36
BEARING DATA AND LIFE ANALYSIS

Bearing Data Tabulation

Table 1 lists the array, of data tabulated for twenty-six ball and

cylindrical roller bearings. In most cases complete data on bearing cage

geometry were not available, so 1t was necessary to estimate noncrltlcal

cage dimensions such as width for the calculation of cage mass used 1n the

bearing life analysis. In some cases 1t was also necessary to assume a

roller crown configuration because 1t was not specified.

Shaft and housing geometries and fits were generally not available so

bearing operating clearances had to be assumed for the life analysis.

Because of the variation 1n completeness of available bearing data on

manufacturers drawings, standard drawing formats and data tables were

generated. These are shown with four examples of General Electric Co.

bearings 1n the figures of appendix E.

Computer Analysis of Bearing Life

A total of 44 bearings were analyzed. The results are summarized 1n

tables 2 through 5. Fatigue lives were analyzed using the computer program

SHABERTH developed by SKF Industries, Inc. Attempts to analyze three ,

additional cylindrical roller bearings with lobed raceways and large roller

complements using the computer program CYBEAN were unsuccessful due to

convergence difficulties caused by the large roller complements. Data on :

several tapered and spherical roller bearings were also received from

TSARCOM. These were not programmed because the specification 1s limited to

ball and cylindrical roller bearings. Data on several additional ball and

cylindrical roller bearings were Incomplete and Insufficient for fatigue

life analysis, so the total bearing analysis effort was limited to 44

bearings. Bearing fatigue life data are summarized 1n table 2.

From Initial calculations, the Lyg Hves for many of the bearings

seemed quite low, much lower, in fact, than the lives for many of the

bearings calculated by the manufacturer. Manufacturer's data for the

bearings 1n two aircraft transmissions, the CH-47D and AH-1J, were received

from TSARCOM and were used for the comparison. The generally low fatigue

lives calculated using SHABERTH prompted detailed Investigations using

selected bearings on the effects of surface finish, radial clearances, oil

viscosity, and operating temperature on fatigue life. In addition, the

lives of CH-47D bearings were calculated for cubic mean and maximum power

loads with both MIL-L-7808 and MIL-L-23699 oils for direct comparison with

manufacturer's data (table 3). Similarly, the AH-U bearing lives were

calculated at 60 percent and 100 percent power loads for direct comparison

with manufacturer's data (table 4). In all , a total of 119 computer runs

were made 1n the initial phase of the bearing analysis. Because of the wide

variance in the fatigue lives predicted for selected CH-47D bearings and the

manufacturer's data, a follow up program was conducted with the manufacturer

using his temperature data and a material life factor of 6 (table 5). The

resulting life comparisons are discussed below.

3-7
The following assumptions were made for the purposes of the analysis:

The data received were limited to detailed bearing geometry, loads, speeds,

and o1l-1n temperature (210 °F). No Information on actual operating

temperatures, shaft fits, shaft and housing geometry, and shaft and housing

materials was furnished, so 1t was necessary to make engineering assumptions

of operating contact angle for ball bearings and operating clearance for

cylindrical roller bearings.

In all the 1nt1al phase studies a material life factor of 1 was

assumed. The fatigue life for any assumed material life factor can easily

be calculated by multiplying by the factor. Bearing operating temperatures

were assumed to be 230 to 240 °F. In most cases, this 1s probably low. As

a result, the predicted bearing lives are probably higher than 1f an

Increased operating temperature was assumed. The lubricant life factor 1s

calculated by the program. It 1s a direct result of the calculated

elastohydrodynamlc film thickness at both rolling element - race contacts

and the composite surface roughnesses.

Table 2 lists the lubricant-life factors at the outer and Inner race

contacts for each of the bearing life calculations. When the lubricant life

factor 1s less than 1, there 1s a penalty on life due to Incomplete

elastohydrodynamlc lubricant films and asperity Interactions 1n the Hertzian

contacts.

Tables 3 and 4 give comparisons of predicted bearing lives

(manufacturer's and this effort using SHABERTH) assuming a material life

factor of 1 and bearing temperatures of 230 to 240 °F for, respectively,

CH-47D bearings and AH-1J bearings. Further correspondence and data Input

from the CH-470 manufacturer led to the data tabulated 1n table 5. The

assumptions here were a material-life factor of 6 and a bearing temperature

of 170 °F.

i

Effects of Design and Operating Variables

In a number of cases where low bearing lives were obtained with the

Initial set of assumptions made, multiple runs were made varying surface

finish, cylindrical roller bearing diametral clearance, oil viscosity

effects (MIL-L-7808 and MIL-L-23699 oils), and bearing operating temperature

to determine their effects on bearing life. These data are tabulated 1n

table 2.

Surface Finish Effects. - A number of bearings were analyzed, not only i

with the manufacturer's specified surface finishes for the outer, Inner, and

rolling elements, but also with Improved surface finishes to determine what

the theoretical effect of better surface finishes would be on their fatigue

lives.

In some cases the elastohydrodynamlc film conditions are extremely

marginal and Improvements 1n surface finish from the standard 8 y1n. RMS on

both races and 4 pin. RMS on the rolling elements, to 4 y1n. throughout, and

even to 2 y1n. throughout, showed no Improvement 1n life. Examples of

bearings 1n this category are 204-040-424, 204-040-136, and 114-DS-160. A

slight Improvement 1n life of bearing 145-DS-018 was noted with an assumed

Improved race surface finish. The life Improvement was rather nominal, from

38
49 to 58 hours. This slight Improvement comes about because the EHD

conditions were too marginal to achieve any significant Improvement 1n life

through the Improved surface finish.

Several bearings showed significant Improvement 1n life when an Improved

surface finish condition was assumed. In this category are Included

bearings 114-DS-665, 114-DS-284A, 114-DS-667, and 114-DS-571. These

bearings showed life Improvement factors from 3 up to about 10. Life data

with the manufacturer's specified surface finishes are listed.

Diametral Clearance Effects. - The life of cylindrical roller bearings,

particularly heavily loaded bearings, 1s clearance-sensitive. Bearings

70952-08557 and 114-DS-665 Illustrate this. Improvements 1n life of about 2

to 1 can result with decreasing diametral clearance, resulting 1n Improved

roller load distribution. An excessively large operating clearance can

result 1n a life penalty. A detailed analysis to optimize the running

clearance 1n bearings where life 1s marginal can be potentially beneficial.

011 Viscosity Effects. - Some bearings show Improved life with the

higher viscosity MIL-L-23699 oil than with MIL-L-7808 oil. If EHD film

thicknesses are very marginal (low film thickness - surface roughness

ratio), no Improvement 1n life 1s likely to be seen. An example 1s bearing

204-040-136. If lambda, the film thickness - surface roughness ratio, 1s 1n

the range from 0.5 to 1.5 with the lower viscosity oil, then a significant

Improvement 1n predicted life can be expected with a higher viscosity oil.

Examples are bearings 205-040-246, 114-DS-668, and 114-DS-670.

Operating Temperature. - An effect similar to that seen with different

viscosity oils can be obtained by assuming a range of bearing operating

temperatures. As the assumed bearing operating temperature Increases, the

fatigue life would be expected to decrease because the effective oil

viscosity decreases. This has the effect of diminishing the EHD film

thickness conditions lowering the lubricant life factor. Bearing 6038-T-48,

a split Inner-ring ball bearing, was analyzed assuming bearing operating

temperatures ranging from 239 to 428 °F. Over this range of operating

temperatures there 1s a significant change 1n the viscosity of the oil. For

this particular study the oil chosen was MIL-L-23699. The predicted L-|g

life at 239 °F 1s 702 hours and 1t steadily decreases to a predicted LIQ

life of 98 hours at 428 °F. This Illustrates the significant effect that

operating temperatures can have on bearing predicted life. In order to

accurately predict the effects of oil viscosity on bearing life, 1t 1s

necessary to know what the actual bearing operating temperatures are.

Comparisons with Manufacturer's Life Data

Fatigue lives predicted by SHABERTH are generally lower than those

calculated by the manufacturers of the AH-1J and CH-47D aircraft. For the

AH-1J bearings, 1f a material life factor of 5 1s assumed, then the two sets

of bearing lives agree reasonably well. The disparities 1n predicted lives

for the CH-47D bearings, shown 1n table 3, are greater, sometimes exceeding

an order of magnitude. The data 1n table 3 and table 4 (AH-1J bearings)

assume a material life factor of 1 and bearing temperatures of 230 to

240 °F. The disparities 1n the CH-47D bearing data prompted a follow up

study with the manufacturer. Manufacturer's temperature data (a bulk oil

39
temperature of 160 °F and a bearing temperature of 170 °F) and a material

life factor of 6 were used. The resulting data are shown 1n table 5.

Agreement 1s reasonably good, but still lower than the manufacturer's

predictions. These differences may be due partly to the fact that only

single bearing solutions were obtained 1n this Investigation because

complete shaft and housing geometry data and fits were not available. The

validity of bearing fatigue life predictions can only be determined by

rigorous testing under conditions which accurately simulate actual operating

conditions and by comparisons with field experience. An 1n-depth

examination of field experience with the AH-1J and CH-47D bearings would be

Invaluable. In particular, the methodology of predicting life 1n the low

lambda (ratio of EHD film thickness to surface roughness) region needs to be

explored.

It 1s Important to note that the AFBMA method disallows the use of a

material life factor greater than 1 at low lambda ratios, when EHD

conditions are marginal. Under poor EHD conditions an Increased Incidence

of surface-originated failures can be expected. Under such conditions

material cleanliness becomes less Important. For many of the AH-1J and

CH-47D bearings EHD film conditions are marginal because of heavy loads, so

the validity of using a high material life factor 1s questionable. This

needs to be verified by comparisons with either or both rigorous fatigue

life testing and field experience.

RECOMMENDATIONS

In order to assess the value of the two specifications presented 1n this

report they must be Integrated Into the Army system and Implemented.

Realistically, no specification 1n Its Initial form, even when reviewed by a

broad spectrum of potential suppliers, can be expected to be flawless. Only

by Implementation and use will whatever shortcomings that do exist come to

the surface. By use 1n the Army system, any called for modifications and/or

additions can be periodically Incorporated to eventually arrive at

specifications which will both Improve quality control of ball and

cylindrical roller bearings and Increase availability. The value of

programs like this can only be realized 1f the results are Implemented.

In the case of the Specification for Ball and Cylindrical Roller

Bearings, distribution to candidate vendors should elicit proposals to

Include the data Items which are lacking. The engineering representatives

of Industry foresaw no difficulty 1n making this Information available. One

of the most glaring aspects of the present procurement system 1s the lack of

complete data on bearings procured.

With the Specification for Ball and Cylindrical Roller Bearings 1n place

providing definition of bearing variables and operating conditions, positive

findings could result from a study of the effect of Improving bearing life

and reliability (reduction 1n life scatter) on readiness of complete

helicopters. This could lead to reduction 1n the number of helicopters

required to maintain a specified effective force.

The specification "Rework, Refurbishment, and Restoration of Aircraft

Engine and Power Transmission Cylindrical Roller and Ball Bearings" should

be Integrated Into Army procedures and upgraded as required, based on

40
experience with Its use. Full Implementation will require, after a period

of familiarization by Army personnel, some hands-on participation by experts

1n specialized fields Including, but not limited to:

Identifying and quantifying significant variables

Use and malntanence of equipment

Recognizing causes of dimensional and textural variations, Including

Interrelated discrepancies

Organizing and scheduling such talent to be available as required 1s a

challenging assignment.

The Importance of compiling complete operating conditions and geometry

data for all bearings cannot be overemphasized. The computer life analysis

procedure can be used to Investigate the possibility of enhancing the life

expectancy of any bearing through geometry optimization (Improved surface

finish, cylindrical roller bearing diametral play, and ball-bearing contact

angle and curvatures). Of course, life predictions are not meaningful

unless field experience 1s logged for comparison with predicted lives.

Careful computer life studies along with possible geometry changes should be

considered for any bearings which exhibit less than satisfactory service

lives.

REFERENCES

1. Hanau, H., et al., "Bearing Restoration by Grinding", Proc. Joint Army -

NASA Seminar, USAAVSCOM-TR-76-27, May, 1976.

2. Bamberger, E. N., et al., "Life Adjustment Factors for Ball and Roller

Bearings - An Engineering Design Guide", ASME, N.Y., N.Y., 1971.

3. Rohllk, H. E., Coe, H. H., Crouse, J. E., Hody, W. F., Jones, R. E., and

Klann, J. 1.: "Turbomachlnery Technology", from Selected Technology for

the Gas Industry. NASA SP 5103, March 1975, pp. 129-186.

4. Bamberger, E. N., Zaretsky, E. V., and Signer, H., "Endurance and Failure

Characteristics of Main-Shaft Jet Engine Bearing at 3 x 106 DN",

J. Lubr. Techno!., Trans. ASME, Ser. F, Vol. 98, No. 4, Oct. 1976,

pp. 580-585.

5. Jones, A. B., "Ball Motion and Sliding Friction 1n Ball Bearings", J.

Basic Engr., Trans. ASME, Ser. D, Vol. 81, No. 1, March 1959, pp. 1-12.

6. Jones, A. B., "A General Theory for Elastlcally Constrained Ball and

Radial Roller Bearings under Arbitrary Load and Speed Conditions", J.

Basic. Engr., Trans. ASME, Ser. D, Vol. 82, No. 2, June 1960, pp.

309-320.

7. Harris, T.A., "An Analytical Method to Predict Skidding 1n Thrust Loaded

Angular - Contact Ball Bearings", J. Lubr. Technol., Trans. ASME, Ser. F,

Vol. 93, No. 1, Jan. 1971, pp. 17-24.

41
8. Crecellus, W. J., Harris, T. A., and Muldel, M. H., "Dynamic Analysis of

High-Speed Ball Bearings Under Combined Loading", SKF-AE-72A004, SKF

Industries, Inc., 1972.

9. Crecellus, W. J., Heller, S., and Ch1u, Y.P., "Improved Flexible

Shaft-Bearing Thermal Analysis with NASA Friction Models and Cage

Effects", SKF-AL-76P003, SKF Industries, Inc., Feb. 1976.

10. Kleckner, R. J., and P1rv1cs, J., "High-Speed Cylindrical Roller Bearing

Analysis, SKF Computer Program CYBEAN, Volume I, Analysis",

SKF-AL-78P022-Vol. I, SKF Industries, Inc., King of Prussia, Pa., NASA

CR-159460, 1978.

11. Kleckner, R. 3., and Plrvlcs, 3., "High-Speed Cylindrical Roller Bearing

Analysis, SKF Computer Program CYBEAN. Volume II, Users Manual,"

SKF-AL-78P023-Vol. 2, SKF Industries, Inc., King of Prussia, Pa., NASA

CR-159461, 1978.

12. Kleckner, R. J., P1rv1cs, J., and Castelll, V., "High Speed Cylindrical

Rolling Element Bearing Analysis 'CYBEAN1 Analytical Formulation" J.

Lubr. Technol., Trans. ASME, Ser. F, Vol. 102, No. 3, July 1979,

pp. 380-390.

42
TABLE 1. - TYPICAL INDIVIDUAL BEARING DATA

ITEM

Type of Bearing

Bore, in

O.D., in

Width, in

Rows and Number of

Roll Elements

Ball or Roller Dia., in

Contact Angle

Race Configuration

I Ring Curvature

0 Ring Curvature

Type of Retainer

Ball/Pocket Clearance

Retainer/Ring Cl.

I Ring O.D./O.R. I.D.

I Ring Surface Finish*

0 Ring Surface Finish*

Roll. El, Surf. Finish*

Speed

Oil in °F

Thrust Load, Ib.

Radial Load, Ib.

Radial Cl. Unmounted

Cage Land Width, in

1

BEARING NUMBER

7-113100062

Ang. Cont. Ball

2.5591

4.7244

2.7165

3/14 (one

opposed)

.6875

30° DT

25° preload

0 Ring relieved, I

Ring Full

Shoulders

52 percent

± 1/2 percent

52 percent

± 1/2 percent

1 pc. mach'd

AG/plate, I

Ring Land Rdg

.018

I Ring

.011-. 019

3.257

6 min.

6 min.

2 min.

20,000

210 °F

2691

.4517

.0069/.0077

see note 1.

205-040-246

Ang. Cont. Ball

3.1491

5.5118

3.0709

3/15 (one

opposed)

.78125

25° Unmtd.

0 Ring relieved, I

Ring Full

Shoulders

52 percent

± 1 percent

52 percent

± 1 percent

1 pc. mach'd

I Ring Land

Riding

.0077 min.

I Ring

4.718

3 min.

6600

210 °F

4274

3175

see note 2.

70951-08363

Deep Groove

Ball, Split

I Ring

4.7244

7.874

2.7559

2/16

1.062

38-1/2'

* 1-1/2°

Deep Groove

I Ring Split

52 percent

(.5525)

51.5 percent

(.5472)

1 pc. mach'd

I Ring Land

Riding

.025-. 03

.015-. 025

5.870

8 min.

8 min.

4 min.

258

210- °F

14,437

6315

.0125 min.

see note 3

70951-08362

Deep Groove

Ball, Split

I Ring

2.3622

4.320

.8661

1/14

.625

28°

* 1-1/2°

Full Shoulder

I ring, one

hole from

bore

52 percent

51.5 percent

1 piece

Land Riding

.022-. 030

.013/.022

3.085

8 min.

8 min.

4 min.

20,900

210 °F

0

1003

.004 min.

see note 4.

2-300-056

Deep Groove

Ball, Split

I Ring

2.7559

4.9213

.9449

1/15

.6875

25-1/2°

Full Shoulder

52 percent

51.5 percent

1 piece

Land Riding

.020-. 027

.016/.022

3.495

8 min.

8 min.

2 min.

19,700

210 °F

1133

44

.0042/.005

see note 5.

* AA min.

43
TABLE 1. - Continued.

ITEM

Type of Bearing

Bore, in

O.D., in

Width, in

Rows and Number of

Roll Elements

Ball or Roller Dia., in

Contact Angle

Race Configuration

I Ring Curvature

0 Ring Curvature

Type of Retainer

Ball /Pocket Clearance

Retainer/Ring Cl.

I Ring O.D./O.R. I.D.

I Ring Surface Finish*

0 Ring Surface Finish*

Roll. El, Surf. Finish*

Speed

Oil in °F

Thrust Load, Ib.

Radial Load, Ib.

Radial Cl. Unmounted

Cage Land Width, in

BEARING NUMBER

1-300-015

Split I Ring

Deep Groove

Ball

1.9685

3.5433

.7874

1/13

.5000

19-1/4°

Full Shoulder

52 percent

52 percent

One Piece

Land Riding

.015-. 024

.012/.017

2.515

10 min.

10 min.

4 min.

24,000

210 °F

450

0

.0037/.0047

see note 6

5034-T-28

Split I Ring

Deep Groove

Ball

1.5748

3.3465

.984

1/12

.5625

26* * 2°

Full Shoulder

Flanged O.R.

Split I.R.

52 percent

± 1/4 percent

as above

One Piece

0 Ring

Land Riding

.015-. 020

.012/.017

12.823

4 min.

4 min.

2 min.

20,900

210 'F

720

80

.0035/.0047

see note 7

6038-T-48

Split I Ring

Deep Groove

Ball

1.808

2.900

.636

1/15

.375

31.5" ± 1.5°

Full Shoulder

Split I.R.

53 percent

± 1/4 percent

51 -

51-1/2 percent

One Piece

0 Ring

Land Riding

.010-. 015

.029 max.

2.602

4 min.

4 min.

2 min.

44,700

210 °F

417

62

.027/.0035

see note 8

70952-08557

Cy. Rol. Dbl.

Ribbed I Ring

STR.O.R.

6.4961

8.4646

.9449**

1/30

.6299D

.6299L

Double Ribbed

I Ring

STR.O.R.

One Piece

Mach'd I Ring

Land Riding

.015/.025

7.096

8 min.

8 min.

4 min.

258

210 °F

0

7086

.0074/.0099

7095208556

Cyl. Rol. Dbl.

Ribbed I Ring

STR.O.R.

7.874

9.8425

.9449

1/39

.5906D

.5906L

Double Ribbed

I Ring

STR.O.R.

One Piece

Mach'd I Ring

Land Riding

.012/.022

8.497

8 min.

8 min.

4 min.

1206

210 °F

0

4842

.0093/.0113

* AA min.

** I Ring has extended length for set-screw mounting

44
TABLE 1. - Continued.

ITEM

Type of Bearing

Bore, in

O.D., in

Width, in

Rows and Number of

Roll Elements

Bal 1 or Rol ler Oia. , in

Contact Angle

Race Configuration

I Ring Curvature

0 Ring Curvature

Type of Retainer

Ball/Pocket Clearance

Retainer/Ring Cl .

I Ring O.D./O.R. I.D.

I Ring Surface Finish*

0 Ring Surface Finish*

Roll. El, Surf. Finish*

Speed

Oil in °F

Thrust Load, Ib.

Radial Load, Ib.

Radial Cl. Unmounted

Cage Land Width, in

BEARING NUMBER

114-DS-665

Cyl. Rol. Dbl.

Ribbed Inner

STR.O.R.

2.9528

6.2992

1.4567

1/12

.9843D

.9746L

Double Ribbed

I Ring w/ext'd

Hub STR.O.R.

One Piece

Mach'd I Ring

Land Riding

.Oil/. 016 circ

.020/.025 Axial

.006/.016

3.950 calcul

8 min.

8 min.

8 min.

15,066

210 °F

0

4999

.0025/.0030

.211

5034-T-06

Cyl. Rol. Dbl.

Ribbed 0 Ring

Ext'd STR I.R.

1.5768

2.6772

.5906

1/14

.27560

.2756L

Double Ribbed

0 Ring

STR. I.R.

One Piece

Mach. 0 Ring

Land Riding

.006/.013 Ax

.005/.013 circ

.006/.014

2.291

4 min.

4 min.

4 min.

20,900

210 °F

0

80

.0010/.0014

.096 Calc.

5035-T-69

Cyl. Rol. Dbl

Ribbed 0 'Ring

STR. I.R.

1.5700

,2.1963

.395

1/14

.19690**

.1969L

Double Ribbed

0 Ring

STR. I.R.

One Piece

Mach. 0 Ring

Land Riding

.006/.013 Ax

.005/.013 cir

.005/.013

1.988

4 min.

4 min.

4 min.

20,900

210 °F

0

60

.0007/.0011

.081 Calc.

5036-T-87

Cyl. Rol. Dbl.

Ribbed 0 Ring

.STR. I.R.

1.9695'

2.8897

.532

1/18

.2756D

.2756L

Double Ribbed

0 Ring

STR. I.R.

One Piece

Mach. 0 Ring

Land Riding

.006/.013 Ax

.005/.013 cir

.006/.0013

2.607

4 min.

4 min.

4 min.

44,700

210 °F

0

80

.0016/.0020

.100 Calc.

2-300-034

Cyl. Rol. Dbl.

Ribbed 0 Ring

NO I.R.

2.0448 under

rollers

2.9528

.6299

1/18

.3150D

.3150L

Double Ribbed

0 Ring

One Piece

Mach. 0 Ring

Land Riding

.002/.018

2.559

6 min.

2 min.

16,000

210 °F

0

4

.100 Calc.

P.O. =2. 360

* AA min.

** Crown radius = 10" .065 cyl. length

45
TABLE 1. - Continued.

ITEM

Type of Bearing

Bore, in

O.D., in

Width, in

Rows and Number of

Roll Elements

Ball or Roller Dia., in

Contact Angle

Race Configuration

I Ring Curvature

0 Ring Curvature

Type of Retainer

Ball/Pocket Clearance

Retainer/Ring Cl.

I Ring O.D./O.R. I.D.

I Ring Surface Finish*

0 Ring Surface Finish*

Roll. El, Surf. Finish*

Speed

Oil in °F

Thrust Load, Ib.

Radial Load, Ib.

Radial Cl. Unmounted

Cage Land Width, in

BEARING NUMBER

2-300-035

Cyl. Rol. Dbl.

Ribbed I Ring

STR. O.R.

3.3465

5.1177

.8661

1/22

.4921D

.5443L

Double Ribbed

I Ring STR

O.R.

One Piece

Mach'd I Ring

Land Riding

.016/.022A

.008/.012D

.012/.022

3.9713

8 min.

8 min.

5 min.

19,700

210 °F

0

163

rounded up

.0035/.004

.133 Calc.

P.O. =4. 257

6876011

Cyl Rol. Dbl.

Ribbed 0 Ring

NO I.R.

1.1424 under

rollers

1.6535

.3543

1/unk.

One Piece

Mach. 0 Ring

Land Riding

1.414

51,120

210 °F

0

9.25

6871508

Deep Groove

Ball Brg. w/

frac'd 0 Ring

w/O.R.ret rgs

.7874

1.6535

.5856

1/11

.2812

20.5°

Deep Groove

w/frac'd

0 Ring

53 percent

52 percent

One Piece

Mach 0 Ring

Land Riding

.007/.017 Tot

Dia. Clear.

1.381

51,120

210 °F

157

13.3

.0014/. 0021

2-300-011

Deep Groove

Split I Ring

2 Row Ball

Brg

2.5591

4.7244

2 rows 1.811

1 row .9055

2/14

.6875

23-29°

Deep Groove

Split I Ring

.004 Grinding

Shims

51 percent

52 percent

One Piece

Mach. 0 Ring

Land Riding

R.D. 3.6417

.01457. 0185

.020/.025

4.059

8 min.

8 min.

2 min.

16,000

210 °F

2730

88

.0033/.0043

.0078 Calc.

2-300-059

Med. Groove

Double Row

Ball Brg.

2.1654

3.1496

1.0236 overall

.5118 one row

2/16

.3125

15°

Med. Groove

Solid I Ring

51 percent

52 percent

Two Piece

Ri vetted I Rg

Land Riding

.008/.013

.014/.022

2.481

6 min.

6 min.

2 min.

16,000

210 °F

350

89

.00087.0012

.160 min.

* AA min.

46
TABLE 1. - Continued.

ITEM

Type of Bearing

Bore, in

O.D., in

Width, in

Rows and Number of

Roll Elements

Ball or Roller Dia., in

Contact Angle

Race Configuration

I Ring Curvature

0 Ring Curvature

Type of Retainer

Ball /Pocket Clearance

Retainer/Ring Cl.

I Ring O.D./O.R. I.D.

I Ring Surface Finish*

0 Ring Surface Finish*

Roll. El, Surf. Finish*

Speed

Oil in °F

Thrust Load, Ib.

Radial Load, Ib.

Radial Cl . Unmounted

Cage Land Width, in

BEARING NUMBER

5034-T-07

Dbl. Row

opposed angular contact Sp

I ring, 1 pc

0 rg. 1 w/ext

Ig. for puller

groove

2.4016

4.0400

1.717 overall

1/15

.5625

22.5°-27.5°

1 pc dbl row .

0 rg. separate

I rings opposed contacts

(relieved

center) 1 w/

puller groove

52 percent

± 1/4 percent

52 percent

± 1/4 percent

One Piece

Mach. 0 Ring

Land Riding

.015/.021

.012/.017

3.563

4 min.

4 min.

2 min.

20,900

210 °F

985

60

.0038/.0046

.092 Calc.

145-DS-017

Ang. contact

Dbl. row w/1

pc 0 ring and

2 pc opposed

inner s

2.9528

5.1181

1.8898 overall

.9843 row

2/16

.6875

30°

1 pc dbl row

O.R. separate

inner rgs. w/

opposed cont.

rel. cen. 0 rg

w/flanged OD

52 percent

52 percent

One Piece

Mach. 0 Ring

Land Riding

.008/.017

.017/.025

4.401

6 min.

6 min.

2 min.

3930

210 °F

1061

1185

.0072/.0082

.107 Calc.

P.O. =3. 9903

SB-1062

Back-back 2

row angular

contact relieved 0

rings

**facing out

3.1496

4.3307 .

1.2598 overall

2/24

.3750

17°

Deep Groove

I Ring relieve 0 ring

One Piece

Mach. I Ring

Guided (offset

.0023/.0027)

3.51 min.

.0022/.0028

204-040-136

Deep Groove

Split inner

ring

4.3302

6.6929

.9843

1/21

.6875

40°

Deep Groove

Split I Ring

52 percent

± 1 percent

54 percent

± 1 percent

* AA min.

** O.D. one piece

47
TABLE 1. - Continued.

ITEM

Type of Bearing

Bore, in

O.D., in

Width, in

Rows and Number of

Roll Elements

Ball or Roller Dia., in

Contact Angle

Race Configuration

I Ring Curvature

0 Ring Curvature

Type of Retainer

Ball/Pocket Clearance

Retainer/Ring Cl.

I Ring O.D./O.R. I.D.

I Ring Surface Finish*

0 Ring Surface Finish*

Roll. El, Surf. Finish*

Speed

Oil in °F

Thrust Load, Ib.

Radial Load, Ib.

Radial Cl. Unmounted

Cage Land Width, in

BEARING NUMBER

204-040-036

Rev. U

Deep Groove

Split I Ring

4.3302

6.6929

.9843

1/20

.750

29.5° ± 2°

One Piece 0

Ring, Split I

Ring

52 percent

± 1 percent

54 percent

± 1 percent

One Piece

mach'd inner

ring riding

.014 (ref)

5.133

.010/.0119

see note 9

204-040-036

Rev. V

Deep Groove

Split I Ring

4.3302

6.6929

.9843

1/21

.6875

40°

One Piece

0 Ring, Split

I Ring

One Piece

mach'd inner

ring riding

.005 (ref)

5.133

AA min.

48
TABLE 1. - Concluded.

Note 1. 7-113100062

25° Contact Angle w/preload - 30° w/o

Clearance .0069-.0077 in, .0047-.0055 in

No preload data other than this.

Note 2. 205-040-246

Gage load - 100 Ib./row

Preload on the bearing - 640 Ib.

Preload on tandem pair ± 50 Ib./bearing

P.O. 4.3307 in

Steel Shaft dia. 3.1501 - 3.1505 in Fit .0007 in loose - .0014 in tight

Housing bore 5.5110 - 5.5118 in Steel liner fit .0001 in L-.0008 in T

Note 3. 70951-08363

Shim thickness .010 in

Faces flush under 2500 Ib. gage load for each bearing

Note 4. 70951-08362

Faces flush under 250 Ib. gage load

Shim thickness .005 in

Note 5. 2-300-056

Shim .004 in

Retainer land .092 in

P.O. 3.8386 in

Note 6. 1-300-015

Shim .003 in

Retainer land .108 in

Note 7. 5034-T-28

Shim .004 in

Retainer land .092 in

P.O. 2.434 in

Note 8. 6038-T-48

Shim .009 in

Retainer land .092 in

P.O. 2.354 in

Note 9. 204-040-036

Radial clearance determined with split inner rings clamped

49
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56
TABLE 3-COMPARISON OF PREDICTED BEARING LIVES

CH-47D Bearings

i Bearing No.

I

i

j 145-DS-034

i

i

j 145-DS-018

i

i 114-DS-668

|

i 1 14-DS-669

j

i 1 14-DS-670 i

j

| 1 I4-OS-664

i

Oi,

7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

1

Cubic Mean Load

NAS 3-23520

35850

474

1800

2488

3664

912

1702

i 367

M'fr.

>i 00000

12216

60300

3800

5200

Maximum Power Load

NAS 3-23520

49

303

430

583

89

195

50

M'fr.

> 100000

1280

2082

9820

432

792

57
TABLE 4-COMPARISON OF PREDICTED BEARING LIVES

AH-1J Bearings

Bearing No.

204-040-136

(Brg V)

204-040-270

(Brg VI)

205-040-249

(Brg 11)

205-040-246

(Brg 1)

212-040-456

(Brg XX11 )

212-040-143

(Brg XVI )

212-040-144

(Brg Xlll)

204-040-424

(Brg Xll )

212-040-455

(Brg XXI)

Oil

.7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

7808

23699

60% Load

NAS 3-23520

313

313

19840

19840

2786

2786

306^ >

210

210

449

450

242

242

593

601

M'f r.

2298

40318

9615

1356

659

1476

1072

2143

6562

100% Load

NAS 3-23520

8)

81

3279

3279

316

316

976")

2238

46

46

93

163

75

257

328

321

M'fr.

521

6576

1092

421

184

410

314

710

652

(l) Single bearing life- loads assumed are .33R, .5T and .33M

58
TABLE 5- COMPARISON OF PREDICTED BEARING LIVES (Manufacturer's Data)

CH-47D Bearings

Assumptions:

Bearing temperature= 170°F

Bulk Oil temperature=160°F

Material life factor= 6

Bearing No.

1 14-DS-664

1 14-DS-668

1 14-DS-669

1 14-DS-670

O il

7808

23699

7808

23699

7808

23699

7808

23699

Cubic Mean Load

NAS 3-23520

950

2776

3268

4163

11086

29772

2392

2651

M'f'r

5200

12216

60300

3800

Maximum Power Load

NAS 3-23520

119

406

605

809

1652

5009

281

379

M'f'r

. 792

2082

9820

432

59
8

NOIiVlN3WnyiSNI 1V3M1 1V3H

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Ol

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60
NAS3-23520

APPENDIX A

ATTENDANCE LIST

FIRST INDUSTRY COORDINATION MEETING

January 24-25, 1983

NAME COMPANY

1. Acurlo, John

2. Anderson, William

3. Battles, Roy

4. Branhof, Edward

5. Campbell, Arthur

6. Chase, William

7. Derner, William

8. 0111, James

9. Dutta, Mitten

10. George, Richard

11. Gilbert, Robert

12. Ironside, William

13. Irwln, Arthur

14. Joseph, Martin

15. Keller, Carl

16. Lagasse, Normand

17. Lenskl, Joseph

18. Llnhares, James

19. L1tts, Richard

20. Lundqulst, Daniel

21. McBaln, Neal

22. Malott, R. Clayton

AVRADCOM

ASICO

Bell Helicopters

TSARCOM

Fafnlr

Split Ballbearing

ASICO

A1r Force

AVRADCOM

Kaydon

Garrett Turbine Engine

Pratt and Whitney

ASICO

TSARCOM

Sikorsky

AVCO Lycomlng

Boeing Vertol

AVRADCOM

SKF

TRW

Split Ballbearing

Detroit Diesel

61
NAME

23. McCabe, Jack

24. Morrlssey, T. L.

25. P1neo, Carroll

26. Poole. William

27. Saw1ck1. Hank

28. Scheldt, R. N.

29. Schuetz, Harold

30. Signer. Hans

31. Stern, Helmut

32. Weden, G11

33. Zaretsky, E. V.

COMPANY

MTI

Rollway

General Electric

Pratt and Whitney

Hughes Helicopter

Detroit Diesel

AVRADCOH

Industrial Tectonics

Industrial Tectonics

AVRADCOM

NASA Lewis

62
APPENDIX B

WRITTEN COMMENTS ON FIRST INDUSTRY COORDINATION MEETING

1. Boeing Vertol Co. letter Feb. 2, 1983 (J.M. Lenskl)

letter Feb. 18, 1983 (J. W. Lenskl)

letter June 2. 1983 (J. W. Lenskl)

2. Detroit Diesel Allison letter Feb. 15, 1983 (R. Scheldt)

3. General Electric letter Feb. 10, 1983 (C. B. P1neo)

letter Feb. 22, 1984 (C. B. P1neo)

4. Hughes Helicopter, Inc. letter Feb. 23, 1983 (H. E. Saw1ck1)

5. Industrial Tectonics, Inc. letter Feb. 18, 1983 (H. R. Signer)

letter Mar. 9, 1983 (H. R. Signer)

6. Kaydon Corp. letter Feb. 8, 1983 (R. F. George)

7. Pratt and Whitney Aircraft Group letter Feb. 2, 1983 (W. R. Ironside)

letter Feb. 14, 1983 (W. E. Poole)

note Feb. 14, 1983 (W. E. Poole)

8. Rollway letter Mar. 16, 1983 (T. L. Morrlssey)

9. Sikorsky Aircraft letter Feb. 21, 1983 (C. H. Keller)

10. SKF Industries, Inc. letter Feb. 23, 1983 (R. A. L1tts)

11. TRW Bearings D1v. letter Jan. 31, 1983 (D. Lundqulst)

63
BOEING VERTOL COMPANY S

P.O. Box 16858

Philadelphia. Pennsylvania 19142

7484-JWL-064

February 2, 1983

Arthur S. Irwin Company, Inc.

Technology Consultants

Driftwood Center

Bemus Point, New York 14712

Subject: Summary of Comments Made During Industry Coordination Meeting

- January 24 and 25, 1983

References: (1) Draft of Proposed Critical Bearing Procurement Specification

(2) Draft of Specification - Optimized Bearing Utilization

Dear Art:

I would like to thank you for the opportunity to participate in the Industry

Coordination meeting held in Clevelapd, Ohio on NASA Contract NAS3-23520.

During this two day meeting, many comments were made concerning Boeing Vertol

engineering review of your proposed bearing specifications, references (1)

and (2). This letter is intended to summarize the major comments made during

this meeting. Enclosed is a statement of my review of the specifications and

also a marked up copy of each specification showing recommended changes. If

you have any questions concerning these comments, please call me.

Also during the subject meeting, Bill Anderson indicated that his analysis of

several of our bearings showed very low B-10 lives. Please request Bill to

send me some information concerning these bearings and I will provide him with

our analysis to determine differences in B-10 life.

Looking forward to seeing you again at the next meeting in May.

Sincerely,

BOEING VERTOL-<^MPANY

/mj

Enclosure

64
REVIEW COMMENTS ON BEARING SPECIFICATIONS REFERENCES (1) AND (2)

The intent of the two proposed specifications [references (1) and (2)] is not

very clear. It appears that the specifications were developed to insure that

bearing performance would be improved thus reducing supply problems and also

that information could be available on the drawings to insure proper control

and analysis. It is my opinion that these specifications will not accomplish

these objectives and may result in additional supply problems and higher initial

cost of bearings. If only drawings which were issued after the mid 1970's were

reviewed, you would find that most of this information is available on Boeing

Vertol drawings and that bearing designs are adequate for the application.

The information requested in reference (1) is intended to improve the performance

of bearings and allow for computer analysis of the bearing. Bearing performance

due to fatigue life is not a major cause of bearing rejections. A survey of

bearings rejected at the Corpus Christi Army Depot for the years 1969, 1971 and

1977 show that bearing fatigue failure represented only 1% to 3% of the bearings

rejected. Most bearings are rejected due to corrosion, handling damage, contamination, etc. which are not addressed by these specifications. All information

required to conduct a computer analysis of a given bearing does not belong on a

design drawing. Only information required to make and inspect the bearing should

be on the drawing. Other information belongs in the stress report for the aircraft drive system. Shaft fits, materials, loads, temperatures, etc. should and

could be provided in a stress report. This information should be requested by

the government when the contract for a new aircraft is issued.

The issuance of a common bearing specification for engines and transmissions may

also cause additional problems. There are major differences between engine

bearings and transmission bearings. Most helicopter transmission bearings are

heavily loaded and operate at low to moderate speeds. Materials other than

VIM-VAR M-50 are used because of fits, gear/shaft materials, lower temperatures

and cost considerations. Experience with M-50 in helicopter transmissions has

not always been successful. Fracture and low fatigue lives have occurred. The

option of other materials should be considered in this specification. Also,

other types of bearings such as spherical roller, tapered roller and needle roller

bearings should be included for transmission applications.

The specification for inspection and repair of bearings may cause additional

problems. Many of the current helicopter transmission bearings do not have

separable cages. Bending of tangs or drilling of rivets is not considered to

be good inspection techniques. We have experienced cage failures due to these

operations. Therefore, new cages would be required during inspection of many

of the current bearings inspected per this specification. Also, unless the rework operation is conducted by a facility that is familiar with aircraft bearings,

many potential problems may occur due to improper rework and/or assembly procedures. This factor should be considered when estimating cost savings and

improved scheduling.

65
A final word of caution should be made. If the intent of these specifications

is to update all active bearing designs, major problems will be experienced.

Increase cost for bearing fabrication and bearing drawing changes (bearing detail, next assembly and top assembly drawings) and schedule delays will be

encountered. If these specifications are to be applied to future bearing

designs, then the system can handle and react to these specifications without

a major impact on cost and lead times. Industry has been improving on its

bearing drawings and will continue to do so in the future. More effort should

be directed toward maintenance and handling problems which have been the major

contributors toward bearing supply shortages.

Attached is a marked-up coyp of both specifications. Several recommended

changes are shown. If you have any questions concerning these comments, please

call me on (215) 522-3902. I hope that these comments will assist you in

developing the final specifications on bearings.

66
SPECIFICATIONS

FOR

BALL AND CYLINDRICAL ROLLER BEARINGS

67
ARTHUR S. IRW1N CO

Ttchnology Consultants

Driftwood, R. F. D. 1

Bemus Point, NY 14712

ORIGINAL PAGE S3

Of POOR QUAirTY

MILITARY SPECIFICATION

CRITICAL BEARING PROCUREMENT

[FICATION , - *Ajk**''' *££***+

1 . Scope - this specif icatioir covers the requirements for the qualification

and procurement of^crlticaT^engine and propulsion power train rolling element

bearings .

2. Applicable documents - specifications:

MIL-STD-10

MIL-STD-129

MIL-STD-143

MIL-STD-271

MIL-I-6868

MIL-I-6S66

KIL-H-6875

MIL-C-11796

MiL-B-197

MIL-L-7808

MIL-L-23699

ANSI B46.1

QQ-C-320

AJC-6490

AMS-6491

AMS-2410

AMS-2412

AMS-4616

AMS-2418

AM3-2526

AMS-2430

AMS-2404

ASTM E 588-76

ASTM E 112

ASTM E 18

ASTM B U7-71 Alloy 864

ANSI YU.5

3.. Qualification - Sources for bearing procurement must be qualified by the

original contractor or by TSARCOK.

3.1 Qualification requirements - A statisically significant quantitj^-'

of each bearing must bo successfully operated through* an overhaul

riod without failure in, a flight - weight installation when subj ected

a load - temperature - speed spectrum determined to be controlling

•K by the contractor or military authority.

•J^ 3.2 Reoualification - No less frequently than every 24 months, a statistically significant sample (as determined by the controlling'military

authority) shall be requalified by testing under the current requirements

compatible with current operating regimes in the field.

Inspection - Unless otherwise agreed-to in writing by the cognizant military

authority, all drawing-listed and other noted characteristics ^sh^ll be 100/5

inspected by the contractor and shall be verified by theTOS/yinspector.

Sample plans must be negotiated with the contracting authority^^flei

4.1 Inspection details - Dimensional details shall be verified in detail

to insure achievement-of all characteristics on the drawing. Additional detailed

inspection shall be performed to insure compliance with all drawing notes and

references,^including referenced specifications and processes (to include those

noted in paragraph 2).

5. Procurement - No bearings may be procured from other than qualified sources.

continued next page

68
ORIGINAL PAGE 5S

OF POOR QUALITY

6. Rejection - All components and assemblies which are rejected shall be

UMBMftp identified and removed from the production facility when the DCAS

decision is: Rejection. Salvage or revMK can only be considered after Quality -

Review Board recommendations are studied and approved by the cognizant military

authority.

7. Changs Control - There may be no change to the design, material, tolerances,

processing, quality control plan, procurement sources, heat treat, inspection

standards, nor shop operations or routings without the express written prior

f.nproval of the original contractor or the cognizant military authority.

7.1 Change Control Approval - Any request for change shall be the responsibility of the vendor to submit prior to the initiation of work on the

contract and approvals must be on hand prior to the start of the operation on

which the chorige is to be made.

8. Process and Inspection Approval - Prior to the award of a production contract,

~.ll process operations and all inspection procedures and details will be evaluated and confirmed by the cognizant DCA5 inspectors -to insure compliance with

currently accepted aerospace industry standards. This will include all destructive and non-destructive methods, as well as quality control plans and scaiple

sizes.

8.1. Process and Inspection Changes - As required in paragraph 7, no alteration or change in any operation, process, or inspection procedure may be

icdo without prior review, evaluation, orid approval by the original approval

authority.

en

9. Graving Requirements - All drivings pertinent to the procurement of these

critical bearings shall include tho essential'data and callouts in a format

that complies with the following checklist. It shall be the responsibility of the

original contractor to update his drawings for use by TSARCOM as directed in

his current or follow-on contracts. That information not specifically noted on

the checklist but essential for definition and control of significant characteristics will also be provided by the contractor in compliance with the intent

of thir, specification. These drawings will be completed in a manner prescribed

by ANSI m. 5.

9.ft. Drawing Checklist

V

1X9.1.1. Type of bearing

f"9.1.2. Bore

1X9.1.3. O.D.

^9.1'./... Width

V9.1.5. A7BMA class

• 9.1.6. Number of rolling elements per row

V/9.1.7. Number of rows of rolling elements

^•9.1.8. Basic dynaTnic radial load rating per AFBMA,

Basic static radial load rating per AFBXA

ASTHUR S. IRWIN CO.

Technology Consultants

Trtftwood. R. F. D. I

Srmus-Point, NY 14712

continued next page

69
• ^

3.

1.10. Basic .dynamic thrust rating where applicable

^9.1.11. Basic static thrust rating per AJ^XA where applicable

X9.1.12. Radial internal clearance (total)

• 9.1.13. Gage load for determining radial clearance

• 9.1.14. Diametral clearance for retainer-to-piloting ring

• 9.1.15. Diametral clearance for retainer-to-non-piloting ring

^•9.1.16. Retainer overall width (.H*aO

{

9.1.17. Retainer end face parallelism

9.1.18. Retainer bore-to-O.D. concentricity

9.1.19. Pilot-ring Loeating-diameter concentricity to pilot

diameter

^ 9.1.20. Rolling element to retainer pocket clearance

W*9.1.21. Rolling element complement pitch diameter

9.1.22. Rolling element clearance from tang or retention device

in the operating (mounted) condition

t^9.1.23. Retainer material and hardness

4^*9.1.24.. Retainer plating required arid thickness (per A>3 24.12 )»

V9.1.25. Retainer plating corner build-up tolerance (opntxJto-)

s-^9.1.26. Retainer land-width in contact with the piloting diameter

,\ ix9.1.27. Retainer details and dimensions ^ofrte^At^

w»9.1.23. Surface finish roughness A-A for rolling contact surfaces

9.1.29. Surface finish roughness A-A for mounting surfaces

ix9.1.30. Surface finish roughness A-A for retainer and retainer

piloting surfaces.

9.1.31. Lobing, waviness and chatter tolerances to operating

and mounting surfaces. Peak to valley limits to be given for a

range of lobes per circumference of from 3 to 33- C O^/7o*>/H->)

9.1.32. Special surface texture modifications required {oftno*"H.J

1^9.1.33. Surface treatments of coatings required

I--9.1.34. Assembly cross corner dimensions required

w*9.1.35. Flushness requirements (where applicable)

^9.1.36. 2nd piny or end float limits

• 9.1.37. Gage lo.id for end play check

v-^9.1.38. Material for rings and rolling elements

^9.1.39. Special he.it treat required (vhere applicable)

i-x9.1.40. Hardness range required

•X9.1.//I. Dsoring operating temperature range and the stabilization

temperature required to provide against growth of elements or

undesirable transformation products

9.1.4.2.'Bearing materiel procurement, inspection and evaluation

requirements to insure cleanliness, grain control, sufficiency

of working after the ingot is formed and to provide documentation

for tracer.bility. (See 11 )

.1.4.3. Outer ring/inner ring details to prevent creep, circumferential notion or shifting

I.44.. Description of details for special mounting or removing

procedures

ARTHUR S. IRWIN CO. INC. ±. , , Technology Consultants continued next page

Driftwood Center

Bwnus Point, NY J4712

70
UR s. !*W:N co. INC. ORIGINAL PAGE {$

j!o*y Co!ws!{f.flt*

ffwood OnJer

Point. NY 14712

TfAwfcRy Cww^MS Qf pQQp QUALrrY

Driftwood Center ^ '

.A5. Identification- requirements ether than ctandard

military rcquirener.ts

9. 1.4.6. Packaging recuiremer.ts ('dflrtoa/aO

9.1./*7. Installation data

9.1.A7.1. Housing fit, material & vail thickness

9.1.47.2. Shaft fit, materiel and- vail thickness

.A8. Requirement for all evidence of nital etch stainin

to be removed from rolling contact s^fzces £et*4~i"«**^*:'-

.A9. Xnximur! diameter and/or length of rolling elements

to be used with production retainers

ix- 9. 1.50. Standard heat treat procedure or specification reouired

^9.1.51. Inner rias high point 'to be identified (<9p&*J>)

9.2. Cylir.dricnl Searing Requirements - In addition to the general requirements listed in paragraph 9.*, the following are required for cylindrical

bearings .

•^9.2.1. Roller dimeter

*^9.2.2. Holler length

w"9.2.3. Roller crovn radius

9.2./,.. Roller effective length

.9.2.5. Roller erova drop coordinates

.6. Roller cr.d squareness

.7. Roller corner radius runout vith respect .to toller cylindrical oection x

w 9.2.8. Roller, corner diswHBSWM &*>A. ffrf"

^9.2.9. Roller er.d face finish A-A

»**9.2.10. Cage balance tolerance and balancing speed

•*• 9.2.11. C.-ije diameter for locating during balancing

**" 9.2.1 2. Dioneter variation vithin one roller set

^9.2.13. Rcq'.urorr.er.t, if any, for roller cosiplenent to be retained

^

n ^'ie cr-2Q when renoved frora its associated ring

>x-Q,9.'!/- Roller corrxLenent dinraeter variation

9.3. Boll Bearing Requircir.er.ts

^•9.3.''. Contact angle

^9.3.2. Inner ring groove radius as a percentage of ball diameter

'-"9.3.3. Outer rir.s croove radius as a percentage of ball dierieter

w»9.3.A. Shirn thic>.r.ess to be used when grinding split rings

^•9.3.5. Rrr.out of split ring contact face with respect to the bore

of the split rir?g

^9.3.6. Ring groove diasieter and tolerance

^*9.3.7. Gage loac. for ncasuring contact angle

•^9.3.8. Shim.ar.gle

•-9.3.9. Boll gr.-.de

^9.3.10. Ball sphericity and ball complement diameter variation

required e^t^U^c^J^!

fc"*9..3.11. Ring grain orientation to be ...... Yjlniii l UtiH^ p

gr

v-^9.3.12. Cage balance required and balancing speed range along

with diameter for locating during balancing

*-*9.3.13. Identification required to insure alignment and loadsharing of matched sets of multi row bearings

continued next page ... .......

71
ARTHUR S. IRWIX CO. INC.

Technology Consultants 5»

Driftwood Center

Semu* Point. NY 14712

. Race depth as a percentage of ball diameter

. Bearing preload, if any

feiuga load

. Ball groove wobble permissable

^"9.3.18. Standoff of ball groove from locating end face of ring

10. Inspection Processes -^A^ljjispection methods and processes must be approved

• . • si • • v . i &0^* ify^^^^^mf ff^ • i i « • • « • j_ • • * * ^^t < /H

and certified by the c^iggn HglilL-j uLlliuu*Lj a dalagnUd Uluuufch POAOi

10.1 Inspection^ofioSs to be certified

w* 10.1.1. Hardness, metallurgical structure, austenite determination

and material stabilization verification

^10.1.2. Decarburizatior. determination

^•10.1.3. Grindigs burn detection and evaluation

1^10.1.4.. MagnafflK'eTaluation

•10.1.5. Visual defect exanination and evaluation

1^10.1.6. Ultrasonic inspection for subsurface defects

•xlO.1.7. Fluorescent penetrant inspection for surface defects

X'lO.I.S. Surface texture evaluation and control

^10.1.9. Plating process control and verification

. *XI0.1.10. Coating process control and verification

i^10.1,11. S*B*«iB»»» peening process control and verification

^ MO. 1.12. Quality control verification and traceability

10.2. Material Review Board

10.2.1. There shall be provided a formal Material Review Board

procedure and activity which shall be verified by the procuring

agency representative and it shall be presented to the cognizant

military authority for approval in writing.

10.2.2. Material Review 3oard members shall be certified to the

/u7«Ac-re>A -flC.«tS representative and shall not be replaced without acknowledgement by the cognizant military authority.

10.2.3. The Material Review Board shall be the only representative

of the contractor authorized to communicate with the DCAS representative and request deviations.

10.3. Inspection Standards

10.3.1. Standards of acceptance for all inspection processes to

include dimensional masters shall be traceable to the National

Bureau of Standards or shall be proved equal in control and

verification to industry standards.

continued next page

72
ORIGINAL PAGE IS

ARTHUR S. IRWSN CO. INC. **^ POOR QUALITY

Technology Consultants

Driftwood Center .

11. Material - Rings an•&2%%j&&< d Rolling Elements &**^^

-

Type: AISI M-50 HIGH SPEED STEEL, VACUUM INDUCTION MELTED AND VACUUM ARC

REMELTED MATERIAL FOR BALL AND CYLINDRICAL ROLLER BEARINGS

11.1. SCOPE:

11.1.1 This specification covers HAgh gpnnd Forgings, forging stock, nechanical

tubing bars, rods, and coils to be used in the manufacture of high quality

ball and roller bearings.

11.2. PROCESS:

11.2.1 The steel/electrode shall be produced employing vacuum induction melting

process during initial melting, followed by remelting employing vacuum arc

remelting (consumable electrode) process. The initial electrode shall be both

melted and cast under vacuum.

11.2.2 For manufacture of bearings in this category, the bearing supplier shall

purchase, control and test raw material to this specification and certify

confornance thereof.

11.3. REFERENCED SPECIFICATIONS:

The following documents are integral parts of this specification. (Use latest

issue of each.)

.11.3.1 Aerospace Material Specifications:

AMS 2808 Identification, forgings

AMS' 2259 Chemical check analysis limits

AMS 2300 Premium Aircraft-Tiality Steel Cleanliness

Magnetic Particle Inspection Procedure

AMS 2251 Tolerances, low alloy steel bars

AMS 2253 Tolerances, carbon and alloy steel tubing

AMS 2310 Qualification sampling of steels, transverse

tensile properties

AMS 2350 Standards and test methods

AMS 6491 VIM-VAR AISI M-50 steel

11.3.2 American Society for Testing and Materials:

ASTM E112 Estimating the average grain size of metals

ASTM E350 Chemical analysis of carbon steel, low alloy steel,

silicon electrical steel, ingot iron and wrought iton

73
ARTHUR S. IRWIS CO. INC.

Technology Consultonts

Driftwood Center

Bomus Point. NY 14712

ASTM /504 Xacro etch testing of consumable electrode vacuum

arc remelted steel bars and billets

11.4. CHEMICAL COMPOSITION:

11.4.1 The steel shall conform to the following requirements as to Chemical

Composition:

Element

Carbon

Manganese

Phosphorus

Sulfur

Copper

Silicon

0.80 - 0.85

0.15 - 0.35

0.015 Max.

0.008 Max.

0.10 Max.

0.25 Max.

Chromium

Molybdenum

Vanadium

Xickel

Cobalt

Tungsten

4.00 - 4.25

4.00 - 4.50

0.90 - 1/10

0.15 Max.

0.25 Max.

0.25 Max.

11.4.2 A chemical analysis shall be obtained and reported for the master heat for

all elements listed in Para. '4.1. In addition to the heat analysis, each

remelt V.A.R. ingot shall be analyzed for carbon and manganese.

11.4.3 Check analysis may be made by the purchaser in accordance vith the latest

revision of ASTM 59 and AMS 2259 with the exception that check limits for

carbon shall be -0.01 under min. in lieu of ±o".03 per AMS 2259.

11.5. "OHM AN'D CONDITION:

The material shall be supplied in annealed and centerless ground or turned with

a surface finish of 125 3XS or better as necessary to perform immersion ultrasonic

test recuirements per Para. 6.7. Bars or forgir.g rounds shall have-a max.

hardness" of 3MN" 229.

11.6. QUALITY TESTS:

11.6.1 Material shall be uniform in quality and condition, clean, sound and free

.from foreign materials and from surface and internal defects detrimental

to fabrication or to performance of parts. The material shall have r-avr"irui.

<tiull,P uniform mac restructure and grain flow.

*i1.6.2 The manufacturer shall be held responsible for the quality of the material

being furnished and shall make the necessary tests to insure this quality.

74
8,

ARTHUR S. IRW1N CO. INC. ORIGINAL PAGE IS

Technology Consultants __ Q^., -,,„, -_,

Driftwood Center OF POOR QUALITY

Bcmus Point. NY 14712

11.6.3 Magnetic Particle Ste^dovn Test;

11.6.3.1 Specimens shall be taken fron 4 inch square billets

representing the top and bottom of each ingot.

11.6.3.2 Specimens shall be inspected in accordance with AXS 2300.

11.6.4 Macroetch;

11.6.4.1 Billet Inspection: Transverse disc sections shall be cut from both

ends of all billets or bars prior to rolling into bars or extrusion

into tubes. The samples shall be etched in accordance with ASTX A604

in hot hydorchloric acid and water (1:1) at 160-180*7 for sufficient

time to develop a well-defined macrostructure.

11.6.4.1.1 Samples shall show freedom frox pipe, porosity, inclusioas,

segregates or segregation •.

11.6.4.L.2 Samples shall exhibit macrostructure equal or better

than the following aacrophotographs of ASTX A604:

Condition Severity

Freckles A

White Spots A

Radial segregation A

Ring pattern A

11.6.4.2 Finish Product Inspection:

11.6.4.2.1 Transverse disc sections shall be removed from both ends

of all bars and tubes and etched in accordance with ASTX

A604 in hot hydrochloric acid and water (1:1) at 160-18C"?

for sufficient time to develop a well-defined nacrostructure.

11.6.4.2.2 Samples shall show freedom from pipe, porosity, inclusions,

decarburization,-seams^internal or external defects.

11.6.4.2.3 If samples are representative of material prior to centerless

grind/turn operation, any surface defects, seams or decarburization must be within the stock removal zone.

75
ARTHUR S. IRWIN CO. INC.

Technology Consultants

Driftwood Center

Bcmus Point. NY J4712

11.6.4.2.4 Samples shall exhibit no evidence of segregation when

examined visually (no magnification).

11.6.5 Grain Size;

The grain size shall be 8 or finer vith occasional grains as large as 5

permissible when determined in accordance with procedures prescribed in

ASTM E112.

11.6.6 Inclusion Content;

Radial specimens, approximately 0.28 sq. in. in surface area shall be

taken midway between center and surface of transverse discs removed from

billet/bar representative of the top and bottom of each ingot. The hardened

specimens shall be polished on a face longitudinal to the direction of

rolling and rated for inclusion content in accordance with the Jernkontoret

Chart, Method D, Plate III of ASTM E45. No specimen shall exceed the following limits:

Inclusion Sating

Type A B C_ D.

Thin 1.5 l7o 1.0 l7s

Heavy 1.0 0 0 0

11.6.6.1 For types A, B and C thin combined, there shall be not more than

three fields of So. 1.5A type or No. l.OB and C types and not core

than five other lower rateable A type thin fields per specimen.

For type D thin, there shall be not more than three No. 1.5 fields

and no more than five other lower rateable D type thin fields per

specimen.

T1j6.6.2 A rateable field is defined as one which has a type A, B, C or D

inclusion rating of at least No. 1.0 thin or heavy in accordance

with the Jernkontoret Chart, Plate III, ASTM E45.

11.6.7 Ultrasonic Inspection:

11.6.7.1 All bars and forging rounds shall be immersion

ultrasonic tested in accrodance with, approved procedures.

76
ARTHUR S. 1RWIN CO. INC.

Technology Consultants

Driftwood Center

Bcmus Point. NY 14712

11.6.7.2 The ultrasonic test shall cover both shear and longitudinal

directions and be calibrated to reject the following defects:

Direction Size and Type

Shear .002 x .050 slot

Longitudinal 2056 of 1/6£ in. flat bottomed hole -

Depth: half of section dim.

11.. 7. DEOARBURISATI6N AND SURFACE DEFECTS:

Bars •!' toafeBB shall be of surface condition or centerless ground to a finish

commensurate vith ultrasonic testing requirements.

11.8. TOLERANCES:

Unless otherwise specified, tolerances shall conform to the following:

11.8.1 Bars: Latest issue of. AMS 2251., as applicable

11.8.2 Tubing: Latest issue of A>5 2253 , as applicable to Mechanical Type

11.9. REJECTIONS:

Material not cor-forair.g to this specification or to authorized modifications

will be subject to rejection.

11.10. INSPECTION:

11.10.1 -The bearing supplier shall be responsible for assuring that all tests

and inspections promulgated in this specification are performed.

11.10.2 Material accepted .by theA purchaser, which subsequently reveals defects

not detected curing inspection, is subject to rejection.

11.10.3 Test methods to be followed shall be in conforaance with the ASTM issue

listed in.Al'S 2350, vhen ASTM methods are specified.

77
ARTHUR S. 1RWIN CO. INC. 11,

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

11.11. MATERIAL CERTIFICATION:

11. "*'.*. The bearing supplier shell recuire and aaihtain coaplote certification

for all raw arterial.

11-. 11.2 The material certification shall contain, the following indorsation:

1. Xiir source.

2. Purchase order nuaber

3. Heat numbers

4. Quantity per heat

5. Material specification rxunber (inc. revision txunber)

6. Size

7. Numerical results of specified tests

8. When inaterial capability requirements are specified, vendor

must certify either actual test data or certify capability

9. Chemical analysis

10. Condition of material supplied, i.e. hot rolled, hot rolled

annealed cord drawn, etc.

11. Results of X?I tests

12. lesults of non-netallic inclusion ratings

13'. Results of ultrasonic testing

78
ORIGINAL PAGE IS

OF POOR QUALITY

• •

SPECIFICATION - OPTIMIZED BEARING UTILIZATION

SCOPE t This specification will cover the cleaning, dismantling, Inspection re-evaluation, segregation and rework of bearings which

require no refurbishment. It will also provide for tho.se bearings

which require restoration and refurbishment.

CLEANINGS All bearings will be subjected to ultrasonic cleaning in a

fluid approved for the process such as* Freon or other OSHA acceptable materials which can remove the decomposed lubrication products and dirt on the various surfaces. It is particularly important in this process that filtration be provided to eliminate all

particles greater than 5 microns in size at a rate equal to the

total volume being processed through the filter every five minutes.

Further, it is essential that the filtered material be supplied

through a separate hose and nozzle for washing through the bearing,

purging from it any accumulated contaminates. The bath in which

the bearings are suspended shall be excited ultrasonically by an

approved method so that particles within the bearing will be kept

in motion and suspended in the fluid.

PRELIMINARY INSPECTION* After cleaning and drying, bearings will be

dismantled partially to separate the inner ring (or outer ring)

from the roller/retainer assembly. It will be found that some

bearings are so designed that the rolling element retainer assembly

can be removed intact and will then be available for inspection

separately. In these bearings it is possible to make a complete

study of the rolling contact surfaces of the individual rings and

to subject them to NDT evaluation.

After the separation of the components from the assembly, a preliminary inspection shall be conducted to separate those which

obviously are not capable of continued utilization. 'Those demon- , /

strating badly scarred surfaces, temper coloTa._dua to overheating. -

f'f"-J

galling, deep scores, impact damage resulting in severe brinells

obvoius to the eye, unmagnified, shall be scrapped.Similarly, impact damage resulting in rupture of the surface .and tearing of the

surface shall be cause for scrapping.

NDT EVALUATION* Components separated and cleaned and having passed

preliminary inspection and considered acceptable for further evaluation will be subjected to magnaflux, addy wggent,'«lt»r>gmirU'

•apictlc roponniioG, fluorescent particle penetrant examination

and others that may be added in the future.

Indications, on any surfaces, visible to the naked eye or exceeding

the standards established for aircraft quality rolling element components shall be scrapped at this time.

continued next page

79
2.

VISUAL. EXAMINATION OF ROLLING CONTACT SURFACES* Utilizing a 2 to 5

power magnifying glass, all rolling contact surfaces will be visually inspected to detect cracks, tears, operating smears due to

sliding or insufficient lubrication. In addition, any evidence of

tempering indicating exposure to excessive temperatures shall be

cause for rejection, "ihrmlil -Mirri ba °"y ^"°e^»T% n^ +.n t.mnpflTHng

spopttoai in muni JiuifW uiCtl alatularJ. yiPcaJui'iiiui BMidaaae ef nt^al

ntnh i» 1i 1 ft liji imnmrij mil \\\\\ i |ulni. in —^3

When it is found that all components of a bearing have passed the

above examination satisfactorily, they may be reassembled as sets

(as they originally were removed from service) for continued use.

Parts from two or more bearings must not be mixed.

VISUAL EXAMINATION OF RIKG M3UNTING SURFACES: The mounting surfaces

of inner rings and outer rings shall be examined and dimensionally

verified to insure that their operating dimensions have not been

modified due to wear or build-up during operation. Where such evidence is present and detected dimensionally, such bearings require

regrinding and the complete assemblies shall be reclassified as requiring restoration.

DIMENSIONAL VERIFICATION* General accumulation of fretted material

which is of such a nature as to only increase the average diameter of the O.D. or reduce the average diameter of the I.D. may be

considered for additional verification. Local polishing to remove

such spots may be acceptable, providing the original grinding nap

is not destroyed in the adjacent areas. Where local buffing has

been successful, the parts shall be verified dimensionally to insure that local areas not exceeding 5 degrees of arc around the

circumference, nor greater in width than 1/10 of the overall

length below the original surface can be considered acceptable.

The assembly can be reconstituted with these components.

Where such efforts are not successful, it will be necessary to set

the parts up for regrinding, in which case .002 in. material thickness per side shall be removed prior to replating and regrinding.

VISUAL EXAMINATION OF RETAINER WEAR AREA: The locating surfaces for

the retainer contacts with the ring flanges shall be examined to

insure against detrimental wear which has resulted in pickout or

welding/galling of these areas. Where only genera] wear is found,

these parts shall be examined dimensionally to insure that only

those parts with less than .0005 in. wear on the diameter shall

be used in assemblies to be made of the original components.

Where the pilot surface retainer demonstrates some wear, it is

.essential that the rolling elements be removed from the pockets

in at least 2 sectors of the retainer to insure against detrimental

wear in this area. If the wear does not exceed .0005 in. the reassembly can be performed with these components, with the rolling

elements restored to their original pockets.

80
DETERMINATION OF NEED FOR RETAINER NDT EXAMINATION AND REFLATING i

Where there la significant wear on the retainer as to cause it to

be rejected for immediate reassembly, the plating shall be stripped

and the part shall be subjected to 1!DT examination depending. upon

its original material. Ferrous materials will be mngnaHiiNBr. Nonferrous materials will be subjected to fluorescent penetrant examination.

After passing this examination with no evidence of cracks, especially near the base of the tangs or in the end rings of the retaVner, the parts shall be replated and restored to the bearing

after verification of its after-plating dimensions to the requirements of the original drawings.

DETERMINATION OF THE NEED FOR RESTORATION: Where there is evidence of

surface deterioration, such as galling, frosting, micro-spelling,

or light brinell marks of less than .002 in. in depth; the components of an assembly shall be restored via the following steps.

Re-establish the mounting surfaces and locating surfaces of the

bearing.

These surfaces shall be ground undersize approximately .002 in.

on the side, replated and reground to original bearing dimensions

and tolerances.

STANDARD RACE GRINDING STOCK REMOVALS » If the race surfaces are rejectable by applicable standards, they may be reground to remove

0&.003 in. per side (material thickness) from each race. Care must

be exercised to prevent metallurgical deterioration (burning) due

to excessive pressure and friction from the grinding Awheel . During

this operation it is essential that the original locating surfaces

shall have been determined and that the part shall be mounted on

the spindle or chuck so that the centrality of the raceway groove

shall be maintained with respect to the original mounting surfaces.

This process shall be monitored by nital etch inspection to insure

that grinding burns have not been introduced into the components.

Evidence of the nital etch examination subsequently shall be removed by vibratory finishing under approved methods.

REINSPECTION FOR VERIFICATION OF DIMENSIONAL DETAILS: All characteristics shall be evaluated 100$ to insure compliance with the original

drawing requirements except for the raceway dimensions which shall

be .006 in. different from the original.

PROCUREMENT OF REPLACEMENT ROLLING ELEMENTS: Procurement and evaluation

of materials shall be in accordance with the Critical Bearing Procurement Specification.

continued next page

81
u.

Inspection process to verify dimensions and grinding control

shall be in accordance with requirements spelled out in the original bearing procurement specification.

GRADING AND MATCHING OF DIAMETERS AND ROLLER LENGTHS TO RING SETSt

All rings shall have been measured with diameters and cross-race

dimensions such as. flange to flange dimensions or race curvstures

recorded so that the appropriate diameter and length of rollers

or balls shall be made available to provide for the original

drawing functional geometry.

PREASSEMBLY VERIFICATION OF DIMENSIONS OF MATCHED PARTS: Suitable

quality control plans must be available and followed to insure

that, in matching of parts, there are no deviations permissable

and the assemblies are completed with components that will provide for the proper clearances and rolling element diameter and

length variations.

ASSEMBLY: All components will be processed through an ultrasonic

cleaner to insure against any particulate contaminant and/or

corrosive materials. Parts shall be subjected to spot checks to

assure absence of corrosion. All parts will be coated with the

appropriate mntrr1n\nn mill nil nut nn '

t+ ^Qq^-tM<».^».i^. Assembly shall be completed in accordance with a written assembly process which will

be available to the military inspector for his verification and

audit.

POST ASSEMBLY INSPECTION: There shall be a 10056 inspection of the

assembled bearings to assure:

A. Proper internal clearance

B. Proper rotation and freedom of the retainer - ball or roller set

C. Proper clearance between the rolling elements and the retainer

tang in the assembled bearing (if applicable)

D. Smooth operation free from any clicks, rubbing, noises or catches

apparent by feel of the inspector.

MARKING, CODING AND SEGREGATION FOR PACKAGING: This shall be accom-^/^ &&*>* ,JL

plished in accordance with the original drawing requirements. '^rjT *L\ /-'**"• (,

l

~

SAMPLING FOR QUALIFICATION TESTING AND SCAS VERIFICATION: The appropriate military authority shall, after consultation with the original contractor and bearing manufacturer, establish a qualification test and sanplir.g plan to which the original lot from each

re-manufacture or restoration manufacturer shall be subjected.

Subsequent sampling for qualification testing shall be at the discretion of the appropriate military authority.

82
BOEING VERTOL COMPANY

P.O.Box 16858

Philadelphia. Pennsylvania 19142

7484-JWL-068

February 18, 1983

Arthur S. Irwin Company, Inc.

Driftwood Center

Bemus Point, New York 14712

Subject: Carburizing Steels Used in Helicopter Drive System Bearings

Reference: Letter dated February 10, 1983 from Arthur S. Irwin

Dear Art:

There are several grades of carburizing steels used in the helicopter drive

system bearings at Boeing Vertol. These materials can be used for the fabrication of one element (inner or outer race) or for the complete bearing. Our

experience with carburized steel bearings has been very good. The attached

table will list the carburizing steel which have been used and specifications

to which the material is certified. The Boeing Vertol specifications listed

are for VIM-VAR and immersion ultrasonic inspected material.

If you have any questions concerning these materials, please contact me.

Sincerely,

BOEING VERTQfe^COMPANY

Lenski Jr.

Senior Engineer

/mj

Attachment

83
SUMMARY OF CARBURIZING STEELS

USED AT BOEING VERTOL

BEARING MATERIAL

SAE 9310

SAE 8620

SAE 4340

HIGH HOT HARDNESS

CARBURIZING STEEL

(5CR-1.4MO-1.35W)

"VASCO"

SPECIFICATION FOR

OLDER AIRCRAFT

AMS 6265

AMS 6276

AMS 6415

PREFERRED SPECIFICATION

NEW AND FUTURE AIRCRAFT

BMS 7-249 TYPE III

(VIM-VAR UTS)

—

BMS 7-250

(VIM-VAR UTS)

BMS 7-223 TYPE III

(VIM-VAR UTS)

OTHER LESS USED STEELS:

CEVM 4620

CEVM 4320

CEVM KRUPP (3310)

CEVM CBS 600 (HIGH HOT HARDNESS)

84
BOEING VERTOL COMPANY

P.O.Box 16858

Philadelphia. Pennsylvania 19142

June 2, 1983

8-7484-JWL-105

Arthur S. Irwln Co., Inc.

Driftwood Center

3emus Point, New York 14712

Subject: Specifications for Ball and Cyl1ndr1cal Roller

Bearings and Rework and Restoration of Aircraft

Engine and Power Transmission Bearings

Qe*r Art:

I am sorry that I was unable to attend the Industry Coordination

Meeting in Cleveland on June 1 and 2. I have reviewed the subject

specifications and would like to provide the following comments

*?<" your information.

o Review of Specification for Ball and Cylindrical Roller Bearings

The specification date, April 29, 1983, appears to be acceptable to Boeing Vertol as presented. All of the problem areas

stated during the January meeting have been corrected.

Presently, Boeing Vertol is working to the basic requirements

of this specification for all new and future bearing designs.

We feel that these requirements are essential for controlling

the design, quality and performance of helicopter transmission

bearings. The only area of this specification that may cause

some problems at Boeing Vertol is Section 8. Our present system of drawing format will have to be modified to meet the

three sheet format requested. Presently, installation and

operating data are not included on drawings but are generally

placed in the drive system stress report for each helicopter.

Although all critical bearing data is available at Boeing

Vertol, it may be difficult for an outside source to easily

locate this information. I feel that your proposed requirement would alleviate this problem.

Section 10 (Material) is acceptable to Boeing Vertol if the

bearing vendors can provide material to this specification.

Boeing Vertol depends upon the bearing vendors to provide the

material to manufacture the bearings. The better the quality

and control of the material, the better the performance of

the bearings should be. Boeing Vertol has improved on the

quality of the gear steels used in the helicopter but we depend

upon the bearing companies to continue to improve on the quality

of bea-ring steels. Unless there are major problems with meeting the requirements of this section, Boeing Vertol agrees with

the material specification, as presented.

85
ORIGINAL PAGE IS

OF POOR QUAtrnr

Other than a few typing errors (MIL-I-7808 versus MIL-L-7808,

etc.)» Boeing Vertol does not recommend any changes to the

proposed specification. Our present bearing drawings and

control requirements for critical bearings (D210-10302-1)

appear to comply with this specification. Therefore, we see

no problems with meeting this specification for all future

bearing designs. If this specification was added to existing

designs, substantial cost increase and delays in procurement

of bearings would be expected.

Review of Specification for Rework, Refurbishment and

Restoration of Aircraft Engine and Power Transmission

Cylindrica l and Ball Bearings

Boeing Vertol has not been involved in any rework, refurbishment or restoration of any bearings except for planet gear/

bearing assemblies. The rework of planet gear/bearing assemblies is conducted by the original bearing supplier. Only

the gear is returned and a new inner race and roller assembly

is installed and the assembly reidentifled. All other bearings which may be overhauled at Boeing Vertol are inspected

to requirements similar to NAVAIR 01-1A-503. Only minor repair (buffing or polishing) is conducted during this inspection.

The requirements of this specification are esential for controllin g rework of bearings. Due to the critical design and

tolerances of power transmission bearings, it is important

that only qualified sources be approved for this type of work.

Boeing Vertol feels that only the original bearing supplie r

should be selected for rework of a given bearing. Until the

experience and skill levels are achieved at the Army depot

level, refurbishment and restoration of bearings should only

be done by the original contractor.

The need for reworking bearings is increasing daily, but until

adequate controls and service experience can be obtained on

reworked bearings, rework of critical bearings should be

approached with caution.

Sincerely,

86
Detroit Diesel Allison

Division of General Motors Corporation Indianapolis operations

P.O. Box 894

Indianapolis, Indiana 46206-0894

February 15, 1983 Phone: (317)242-5000

Cable: GM COMM IND A

File No. A0490

Arthur S. Irwin, Co., Inc.

Driftwood Center

Bemus Point, New York 14712

Attention: Mr. Arthur S. Irwin

Dear Mr. Irwin:

During the meetings of January 24 and 25, 1983 at Cleveland with

representatives of your company, NASA-Lewis Research Center, U. S. Army and

U. S. Air Force, aircraft engine and airframe builders and rolling element

bearing manufacturers two proposed military specifications were discussed in

considerable detail. The first specification covers the requirements for the

qualification and procurement of critical engine and propulsion powertrain

rolling element bearings. The second specification is described as optimized

bearing utilization and covers the requirements for determining if used

rolling element bearings are in need of reworking and if they are in need of

reworking how this should be done.

It is in response to your request for written comments from the attendees that

the following comments are made. Where appropriate these comments are

referenced the proposed specification copies distributed at the above meeting

with these comments further referenced in terms of page numbser, section

number or heading, paragraph number and line number. Where comments outside

of the discussion and consensus at the above meeting are necessary such

rationale is also included.

Specifications for Ball and Cylindrical Roller Bearings. This specification

apparently was prompted by the material requirement for hot hardness

properties provided by M50 tool steel. The inherent brittleness of this

material causing at times very rapid crack propagation and ultimate failure

has given concern towards using other or alternate materials.

87 DA !-i (4-e:;
Mr. Arthur S. Irwin from R.N.S. Scheldt

February 15, 1983

-2-

Page 1, Section 1. Consider specifying which materials are covered by this

specification. Also, consider this specification referring only to ball and

cylindrical roller bearings.

Page 1, Section 2. Apparently "MIL-STD-10" should be changed to

"MIL-STD-100", Specifications MIL-STD-1535, MIL-STD-1520, AMS-6415 and ASTM

584 should also be considered for inclusion.

Page 1, Section 4, line 2, "100% inspected" should be changed to "100%

non-destructively inspected".

Page 1, Section 4, line 3. Change "contractor" to "sub-contractor". Change

"DCAS inspector" to "Government authority or equivalent".

Page 1, Section 4, lines 4 and 5. Delete words following "contracting

authority".

Page 1, Section 4, line 4. Replace "Sample plans" with "Approved sample

plans".

Page 2, Section 6. Include the contractor in the decision making process.

Page 2, Section 7. Add facilities to the group of no change items.

Page 2, Section 8, line 1. Replace "Prior to" with "After".

Page 2, Section 8. Include the contractor in the decision making process.

Page 2, Section 8, line 4. Replace, "accepted aerospace industry standards"

with a better definition.

Page 2, Section 8.1, line 2. Replace "operation" with "specification".

Page 2, section 8.2. Delete this section.

Page 2 and 3, section 9.1. Identify on the drawing as engineering data or

reference items 9.1.8, 9.1.9, 9.1.10, 9.1.11, 9.1.14, 9.1.15, 9.1.21, 9.1.36

and 9.1.41.

88
Mr. Arthur S. Irwin from R.N.S. Scheldt

February 15, 1983

-3-

Page 3, Section 9.1. Consider deleting items 9.1.16, 9.1.17, and 9.1.25.

Page 3, Section 9.1. List as a reference dimension items 9.1.22, 9.1.36 and

9.1.37.

Page 3, Section 9.1. Sharpen the definition of 9.1.27.

Pages 3 and 4, Section 9.1. Use another specification to cover items 9.1.32,

9.1.29, 9.1.42 and 9.1.48.

Page 4, Section 9.1.47. Consider omission.

Page 4, Section 9.1.51. Add "if required".

Page 4, New Section 9.1.52. Add ball or roller drop.

Page 4, Section 9.2.1. Add "and roundness".

Page 4, Section 9.2.3. Add "and flat length".

Page 4, Section 9.2.7. Add "when required".

Page 4, Section 9.2.8. Consider specifying in terms of breakout dimensions

and end blend requirements.

Page 4, Section 9.3.1. Add "specified as required".

Page 4, Section 9.3. Identify as reference dimensions items 9.3.4 and 9.3.8.

Pages 4 and 5, Section 9.3. Add "if required" to items 9.3.5, 9.3.7, 9.3.11,

9.3.14 and 9.3.15.

Page 4, Section 9.3.11. Add orientation angle dimension.

Page 4, Section 9.3.12. Replace "balance required" with "balance as required",

Page 5, Section 9.3. Delete items 9.3.16 and 9.3.18.

Page 5, Section 9.3.17. Correct "permissable" to "permissible".

Page 5, Section 10, line 2. Replace "certified by the cognizant military

authority as delegated through DCAS", with "certified by the prime contractor".

Page. 5, Section 10.1. Replace "Methods to be certified" with "Methods and

Processes to be Certified".

89
Mr. Arthur S. Irwin from R.N.S. Scheldt

February 15, 1983

-4-

Page 5, Section 10.1.2. Add "decarburization allowed on nonfunctional

surfaces".

Page 5, Section 10.1.4. Replace "Magnaflux evaluation with, "Magnetic

particle inspection evaluation".

Page 5, Section 10.1.5. Replace "Visual" with "Surface".

Page 5, Section 10.1.11. Replace "Shot bead peening" with "Peening".

Page 5, New Section 10.1.1.3. X-Ray Diffraction.

Page 5, New Section 10.1.14. Magnetic perturbation.

Page 5, Section 10.2. Consider deleting items 10.2.2 and 10.2.3.

Page 5, Section 10.3.1. Consider if dimensional masters may be traceable to a

source other than the National Bureau of Standards.

Page 6, Section 11.1.1. Replace "High Speed Forgings, forging stock,

mechanical tubing bars" with "forgings, forging stock, tubing, bars".

Page 6, Section 11.3.1. Consider adding AMS 2375.

Page 7, Section 11.3.2. Consider replacing, "ASTM E604" With "ASTM A604".

Page 7, Section 11.4.1. Replace "Chemical Composition" with "chemical

composition".

Page 7, Section 11.4.3, line 3. Clarify minimum carbon requirement so as to

assure desired hardenability.

Page 8, Section 11.6.3. Add "With no additional ultrasonic test required".

Page 9, Section 11.6.6, table. Change ratings for heavy; B, C and D types

from "0" to "1.0".

Page 9, Section 11.6.6.1. Include limits for heavy fields.

Page 9, Section 11.6.7.1, Line 2. Correct "accrodance to "accordance".

Page 10, Section 11.10.2, line 1. Replace "the purchaser" with "the original

Durchaser".

90
Mr. Arthur S. Irwin from R.N.S. Scheidt

February 15, 1983

-5-

Specificatipn - Optimized Bearing Utilization. This specification apparently

was sought to provide the Armed Services greater capability to overcome,

1) uncertainty of procurement, especially during wartime conditions, 2) lack

of availability from "too few" approved sources, and 3) logistics constraints

imposed by current procurement and inventory practices. Should this

specification lead to reworking the individual components of a given bearing,

especially for the critical surfaces and geometry internally, the impact on

continued field usage could well be expected to be premature failure, perhaps

catastrophic. Such undesirable possibilities are enhanced by lack of skill,

facilities, and expertise on the part of those actually doing the reworking.

It is well known that fatigue damage is not easily measured before spalling is

visually seen. Further the fatigue damaged material is not totally removed by

machining to arbitrary depths of 0.002 or 0.003 inches. Thus, the reworked

bearing is only capable of continuing to provide satisfactory service with an

appreciable handicap.

Some may argue that the service life of a rolling element bearing is primarily

limited by such conditions as wear, contamination, lack of lubrication and

abuse in handling and not fatigue life. However, the load carrying capacity

and the corresponding expected fatigue life are still important considerations

in selecting bearings in any design and it would not seem prudent to fall

short in this area.

Of at least as great an importance as the reprocessing of bearings is the

impact that each bearing in any mechanism has on the reliability of the total

system. There should be less willingness to rework a critical bearing than to

rework a non-critical bearing.

More detailed comments to this proposed specification below.

Page 1, section on cleaning. Include alternate cleaning methods and whether

the bearings are to be cleaned in the assembled or disassembled condition.

Page 1, section on preliminary inspection, paragraph 2. Degree of distress

should be described in terms of limiting dimensions.

Page 1, section on NOT evaluation, paragraph 1, line 3. Eddy current testing

may not be necessary.

Page 1, section on NOT evaluation, paragraph 1, line 4. Delete "magnetic

resonance".

91
Mr. Arthur S. Irwin from R.N.S. Scheidt

February 15, 1983

-6-

Page 1, section on NOT evaluation, paragraph 1, line 5. Replace "others that

may be added in the future" with "others as required by the original

manufacturer".

Page 3, section on standard race grinding stock removals. Grinding removal

amount seems too arbitrary. Residual stresses resulting from grinding feeds,

speeds and grits appear uncontrolled.

Page 3, section on reinspection for verification of dimensional details, line

3. Grinding removal amount seems arbitrary.

Page 4, section on preassembly verification of dimensions of matched parts,

line 3. Correct "permissable" to "permissible".

Page 4, section on sampling for qualification testing and SCAS verification,

paragraph 1, line 1. Replace "SCAS" with "Military".

Additional comments:

1. New parts replacing used parts should be coded for traceability.

2. Some position should be clarified as to liability in case of an accident

caused by a bearing having reworking processing and/or having

sub-components from sources different from those for the original bearing.

R.N.S. Scheidt

Staff Research Engineer

Technical Services, R&D

Transmission Engineering

RNSS/bjs

cc:

92
GENERA L ELECTRIC

GENERAL ELECTRIC COMPANY . . 1000 WESTERN AVENUE

LYNN, MASSACHUSETTS 01910, Phone (617) 594-0100

AIRCRAF T

ENGINE

GROU P

Subject: Industry Coordination Meeting

on NASA Contract NAS3-23520

Rolling Element Bearings

February 10, 1983

Arthur S. Irwin Co., Inc.

Bemus Point

New York 14712

Dear Sir:

Comments and recommendations are hereby transmitted concerning

your industry coordination meeting held in Cleveland

24, 25 January, 1983.

Also attached are copies of my expense report and receipts

showing the cost (in the amount of $240.23) associated

with attending the subject meeting (see attached expense

account remarks).

Very truly yours,

.CARROLL B. PINEO

Principal Engineer, Bearings & Lube Systems

Lynn Product Engineering Department

attachments

/m

93
SPECIFICATION - OPTIMIZED BEARING UTILIZATION

Much of the inspection and handling procedures for new and used rolling contact

bearings are well covered in the technical manual, "Maintenance of Aeronautical

Antifriction Bearings for Organizational, Intermediate and Depot Maintenance

Levels". This manual is identified as:

NAVAIR 01-1A-503

TM55-1500-322-24

It is recommended that this manual be adopted in situations where the prime

contractor has not issued similar service limits and instructions, regarding

bearing cleaning, handling and inspection.

In addition, it is also recommended that the efforts of the Joint Service

Committee on Bearing Refurbishment headed by Dr. J. Dill at Wright-Patterson

be utilized to the fullest extent during the formulative period to avoid duplication of effort and to promote uniform terminology.

It is also suggested that the prime contractor's recommendations be sought regarding

which bearings are to be refurbished and what category or degree of refurbishment

should be permitted.

Specific Paragraphs

Cleaning

Adopt NAVAIR 01-1A-503 or technical order of prime contractor.

Preliminary Inspection

Prior to inspection, bearings need to be classified for the degree of refurbishment

to be performed and disposition according to configuration (separable vs. nonseparable) and defect types for which no refurbishment is permitted. Need to

carefully define terminology such as "scrap" when the intent is further disposition

or not fit for refurbishment.

NOT Evaluation

Need to address this phase of inspection for bearings in the completely dismantled

state. Some apparent inconsistencies exist here:

If bearing is already dismantled, then a decision has already been made to

refurbish it. Normal practice is then to discard rollers, cage; salvage rings

which could be FPI/MPI inspected at that time. All other NDT processes would

not apply to the used raceways due to surface imperfections which cause too

much "background scatter" or which cannot be interpreted. Same reasoning applies

to balls except snap in ball cage design may allow cage re-use.

94
-2-

Visual Examination of Rolling Contact Surfaces

Use limits provided by prime contractor in technical order manuals. If none

exists, adopt NAVAIR 01-1A-503.

Visual Examination of Mounting Surfaces

Limits and reclassification per prime contractor technical order, or adopt

NAVAIR 01-1A-503.

Dimensional Verification

Use prime contractor technical order instructions and limits. If none exist,

establish limits and instruction for each component to be refurbished by item

number and part number so that bearing application considerations are properly

addressed.

Do not agree that removal of a fixed amount of material is the way to go.

Suggest that stock removal up to a limit specified for each part number as

recommended by the prime contractor.

Visual Examination of Retainer

 : • •

This section should be in two parts: those nonseparable from the bearing, bent

tang, riveted and those where elements can be snapped in and out without damage

or deformation.

Use technical order limits of prime contractor or request limits to be established.

Determination of Need for Retainer NDT Examination and ReplatMig

Normally, serviceability limits permit some wear through plating into base

material. Generally, wear through the plate into the base metal is in cage

pockets, or scoring on the guide lands.

Wear into base metal may also include embedded debris which must be removed

prior to plating. This could mean machining of cage after stripping. Economically,

it would seem better to replace the total cage with a new one at this point.

Should address above conditions, stock removal permitted, plate thickness, clearance

allowed, and control of all processes associated with this.

95
-3-

Determination of the Need for Restoration

If this paragraph refers to mounting surfaces, it appears that regrinding must

be set up from the raceways which is backwards from original manufacture. There

is serious question if this can be done on existing equipment and, if so, the

potential damage to the raceways either due to distortion or tooling is worrysome. Accuracy required is per original requirement.

Recommend removal of local high metal and expansion of serviceability limits be

substituted for regrind/replate.

Standard Race Grinding Stock Remove

Need same process control here that is applied to original manufacture. Speeds,

feeds, stock removal per pass, contour accuracy, control of residual stress,

etc., etc.

Reinspection for Verification of Dimensional Details

6 mil change for each raceway results in 12 mil change to rolling element.

Change wording to " original drawing requirements and refurbishment drawing

allowable modifications."

Procurement of Replacement Rolling Elements

Add heat lot and grind lot traceability requirements.

Grading and Matching of Diameters and Roller Lengths to Ring Sets;

Preassembly Verification....Matched Sets.

Need to define process control for all these items similar to prime contractor

requirements placed on original vendor's processes.

Post Asse/nbly Inspection

Please refer to all the items deemed subject to inspection on the proposed

TSARCOM bearing specification. Quality plan is required.

Sampling/Qualification etc.

Also see Refurbishment Committee effort, re Dr. J. Dill, Wright Field.

96
January 31, 1983

TSARCOM PROPOSED BEARING SPECIFICATION

General Comment

It is recommended that the proposed specification be redirected to

establish prime contractor requirements for the preparation of

bearing drawings' and specifications rather than for the actual

drawing format and specifications.

This will allow present prime contractors who now comply to the

intent of this proposed specification- to continue to use their

existing standards, drawing formats and specifications without

unnecessary changes.

Prime contractor authority and responsibility for implementation of

all aspects of these requirements regarding subcontractors and vendors

are unquestioned practices at present for main shaft bearings and

should likewise be the case for other components such as transmissions

and other vehicle mounted equipment.

The following comments regarding individual paragraphs of the proposed

specification should be considered in the context of the foregoing

general comment, as an overriding posture from this participant.

Specific Comments - Specification Paragraphs and Sub Paragraphs

Title: Critical Bearing Procurement Scope

1. A bearing may be critical due to becoming in short supply,

due to its operating condition being severe, due to consequence

of failure, unique features, etc. If critical due to short

supply this is a temporal situation which would not relegate

the bearing to the category addressed by this specification.

It appears that the content of the specification and proposed

drawing information content is directed at high performance

bearings. The title and scope should be redefined accordingly.

It would appear that criticality due to short supply is not a

part of this effort and is not really addressed herein.

It is also suggested that at least two categories of bearings

be addressed at least on the drawing requirements similar to

our GE drawing formats: main engine or accessory drive formats.

2. Applicable Documents -

This list should include and be limited to all the applicable

specifications invoked within the body of the specification.

97
3. Qualification

Agree that sources should be qualified by prime contractor

but not TSARCOM.

3.1 Qualification Requirements

Qualification requirements vary from that of individual

parts like a bearing to that of the total vehicle which

qualifies all components within the vehicle. Recommend

that the specification state that the prime contractor shall

establish qualification and source approval requirements

as required and subject to approval by the cognizant

military authority.

4. Inspection

Recommend these requirements as written be replaced by wording

with the following intent"

A quality control plan shall be established by the prime

contractor subject to approval by the cognizant military

authority.

4.1 Inspection Details

Suggest the following: A list of significant processes,

dimensions, and other attributes shall be prepared by the

vendor and submitted for approval to the prime contractor.

The quality plan shall address first article inspection

requirements as well as periodic monitoring of all items as

listed within the significant processes list, but not be

limited thereto.

6. Rejection

Specification to require the prime contractor to adopt standard

MRB established procedures.

7. and 7.1 Change Control

Change control procedures are well established for prime

contractors under military contract. Recommend that these

same procedures be prescribed for prime contractors for

vehicles and equipment within the intended use of the

proposed specification similar to that for engine contractors.

8. Process and Inspection Approval

Recommend proposed specification require prime contractor to formulate quality control plan which address these items. Said plans

by the prime contractor are subject to approval as required by

the cognizant military authority.

98
9. Drawing Requirements (Including Sub Paragraphs)

Recommend that the wording of this section allow existing drawing formats and specifications in use by prime contractors be

acceptable, provided that they, contain.the data and intent

sought. This should also provide for abreviated formats which

apply as defined by the prime contractor to less critical

bearings in accessory gearboxes for example. (This practice

is in use today at General Electric AEBG.)

Compliance to ANSI Y14.5 or other such standards should be

specified if prime contractor does not have established drawing

standards which meet the intent of section 9.

Recommend that the format description allow provision to present

data via data sheets, drawing details specifications, standards

in any combination to allow vendors and prime contractors to

use established practices where practical.

9.1.47

Installation data may be obtained from design reports

prescribed by prime contractor model specifications.

Installation data does not belong on the individual part

drawing but rather on the next higher assembly. Submittal of data lists and design reports could be required

as part of the contract requirement as stated by the

military at the time of contract award.

10. Inspection Processes

Again recommend that this type requirement is required in the

prime contractors quality control plan subject to approval by

the cognizant military authority.

99
GENERALS ELECTRIC

GENERAL ELECTRIC COMPANY 1000 WESTERN AVENUE

LYNN, MASSACHUSETTS 01910, Phone (617) 594-0100

AIRCRAF T

ENGINE

GROUP

February 22, 1983

Arthur S. Irwin Co. Inc.

Driftwood

Bemus Point, N. Y. 14712

Attention: Arthur S. Irwin

Dear Art,

At the present time, we do not have any carburring grades of steel

in our rolling element bearings used in GE engines, Lynn or Evendale.

T64 turboprop engine models utilize AISI 9310 carburized gear

shaftings as the inner race of a roller bearing. There are no

Army applications of this turboprop engine model.

Regards,

CARROLL B. PINEO, Principal Engineer

Bearings & Lube Systems Technology

IMZ 240G7, ext 4784

/m

100
Hughes Helicopters, Inc.

Culver City. California 90230

February 23, 1983

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, New York 14712

Dear Art, .

In response to your request of February 10, 1983,

enclosed are sections of our nose box and main transmission.

The basic bearings are M-50 with silver plated steel cages.

However, all the roller bearing inner races are eliminated

and they operate on carburized or nitrided material. As

noted in the attached cross section we do have some unusual

.combinations of bearing materials.

 :

I hope this answers your request, if not, we would be glad

'to send further details.

Very truly yours,

H. E. Sawicki

HES/daj

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104
INDUSTRIAL TECTONICS, INC.

18301 SANTA FE AVENUE, RANCHO DOMINGUEZ, CA 90224 • (213) 537-3750

MANUFACTURER S OF PRECISION BALLS AND BEARING S

bearing division '.

February 18, 1983

Arthur S. Irvin Co., Inc.

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

Specification for Ball and Cylindrical Roller Bearings

Industry Coordination Meeting on Contract NAS3-23520

Gentlemen:

I wish to congratulate Mr. Art Irvin and Mr. Bill Derner for a

well-conducted meeting on January 24 and 25, 1983. The subject

at hand and the numerous comments by the participants were

certainly interesting. Per your request I summarized some of my

thoughts:

Para. 1 - The heed for a specification that standardizes

contractor drawing requirements and provides for * increased

technical documentation was orally explained. Somewhere in the

document, preferably in the "scope" section, this purpose

should be stated. Also, the word "critical" in the title and

scope needs to be explained.

In general, if your specification is not to result in vastly

increased cost of bearings, it should be held simple and

contain only requirements that are truly essential. The draft

discussed at the meeting contained too many detailed requirements. It was suggested that technical data can be specified

on engineering drawings without imposing pertinent inspections

of the hardware. In our experience, the temptation to inspect

all drawing features is irresistable. A typical example exists

with bearings for Navy nuclear reactors. The incredibly high

price of these bearings is a direct consequence of applicable

inspection and documentation requirements.

Para. 2 - Of the "Applicable documents - specifications" we find

only AMS 6491, ASTM E112 and ANSI Y14.5 in the subsequent text.

Your specification must indicate in what way the listed documents are to apply (e.g. the present text in last sentence of

para. 4.1 is not acceptable).

105
Arthur S. irvin Co., Inc.

February 18, 1983

Page 2

To guard against "unqualified" shops manufacturing bearings we

suggest you add the requirement for the bearing vendor's QC

system to meet MIL-Q-9858. This statement would fit well as a

second sentence in your spec paragraph 3.

Para. 3.1 - Suggest you replace these vague and undefined

requirements with a more concrete definition: Who has to do

what, and when.

Para. 3.2 - We seriously question the technical merit and the

cost impact of this requirement.

Para. 4 - One-hundred percent inspection of all drawing features

should be limited to small prototype quantities. For production orders industry-accepted sampling plans should automatically be implemented.

Para. 4.1 - Is redundant and should be omitted.

Para. 5 - Change to read: "No production orders of bearings

may be procured from other than qualified sources (reference

para. 3)."

Para. 6 - Secondary operations to correct reworkable discrepancies and/or replacing rejected components of an assembly

are standard practice in all manufacturing plants. We see no

reasons to restrict this logical procedure. Rewrite paragraph

as follows: "Non-reworkable bearing parts which have been

'rejected' shall be permanently identified and/or removed from

the production floor. Salvaging operations may proceed only

upon approval by the cognizant military authority."

Para. 7 - The proposed text is totally unworkable. Would result

in no bearings getting made. Changes should be classified by

levels of importance and only the highest level should be subject to prior approval requirements. Suggest to rewrite as

follows: "Upon qualification, bearing vendor shall not implement

changes in material, heat treat cycles and inspection levels

unless such changes have received prior approval."

Para. 8 - Must be rewritten: "Processing outlines and general

inspection plans shall be required of a qualified vendor prior

to awarding production contracts."

Para. 8.1 - Suggest a rewrite: "Major deviations from the

approved processing outlines and inspection plans shall require

prior approval by the original approval authority."

Para. 8.2 - Delete this paragraph in its entirety.

Para. 9 - In the first sentence delete the word "critical" and

substitute "pertinent" for the word "essential."

Para. 9.1 - Drawing checklist

1 Q , INDUSTRIA L TECTONICS, INC.
Arthur S. Irvin Co., Inc.

February 18, 1983

Page 3

Para. 9.1.1 through 9.1,. 9 ... OK

Para.'s 9.1.10 and 9.1.11 seem to require a clarification:

Does the. spec propose to include basic load rating (Ca) for

thrust ball and/or thrust roller bearings or is it meant to

include load capacities in thrust direction for radial ball

and/or radial roller bearings? (Refer to ANSI/AFBMA, Standard 9 - 1978, pg. 4, para. 4.2.1 and ANSI/AFBMA, Standard

11 - 1978, pg. 7, table 3 and pertaining note.)

Para. 9.1.12 through 9.1.14 - OK

Para. 9.1.15 - Omit

Para. 9.1.16 - OK

Para. 9.1.17 - Omit

Para. 9.1.18 through 9.1.20 - OK

Para. 9.1.21 - Add notation- " (reference)."

Para. 9.1.22 - Replace with ball/roller drop in retainer pocket

in radial direction, retainer centered."

Para. 9.1.23- OK

Para. 9.1.24 - Omit any reference to plat-ing specif ication (s) .

Para. 9.1.25 and 9.1.26 - Omit

Para. 9.1.27 - "Retainer views and dimensions sufficient to

define part outline."

Para. 9.1.28 and 9.1.29 - OK .

Para. 9.1.30 - "Surface finish roughness A-A for retainer

pockets and piloting surfaces."

Para. 9.1.31 and 9.1.32 - Omit

Para. 9.1.33 - "Special surface treatments or coatings, where

applicable." .

Para.-. 9.1.34 and 9.1.35 - Combine: "Bearing ring face flushness

and/or cross-corner dimension, where required."

Para. 9.1.36 - Suggest this, text should be assigned to paragraphs

9.2 and 9.3 (end play in radial ball bearings and end float for

radial roller bearings).

INDUSTRIAL TECTONICS, INC.
Arthur S. Irvin Co., Inc.

February 18, 1983

Page 4

Para. 9.1.37 - As above, to appear in paragraph 9.3.

Para. 9.1.38 through 9.1.41 - Place at differenct location,

preferably following 9.1.11. In para. 9.1.41 insert "Minimum"

before "stabilization temperature."

Para. 9.1.42 - Rewrite: "Applicable specifications for bearing

material procurement, inspection and evaluation requirements."

Para. 9.1.43 and 9.1.44 - Combine, using the following text:

"Outer/inner ring configurations, showing details of

anti-rotation features or puller grooves, etc."

Para. 9.1.45 - "Identification marking requirements."

Para. 9.1.46 and 9.1.47 - Omit; should not be part of a bearing

drawing.

Para. 9.1.48 - "Nital etch removal requirements."

Para. 9.1.49 - Delete, is redundant to 9.1.20.

Para. 9.1.50 - Delete, is redundant to 9.1.41.

Para. 9.1.51 - "Inner/outer ring high point of eccentricity

marking, as required."

Para. 9.2 - Add "roller" (two places) between words "cyclindrical" and "bearing (s)."

Para. 9.2.1 and 9.2.2 - OK

Para. 9.2.3 - Add "(nominal or reference)."

Para. 9.2.4 - Change to "minimum roller (cylindrical) flat

length."

Para. 9.2.5 - "Roller crown inspection points (gage point and

crown drop)."

Para. 9.2.6 through 9.2.9 - OK

Para. 9.2.10 and 9.2.11 - Add "where applicable"

Para. 9.2.12 and 9.2.14 - Combine: "Roller cylindricity (where

applicable) and roller complement diameter variation."

Para. 9.2.13 - Delete. Requirement is addressed in proposed

text of 9.1.22.

Para. 9.2.X - For purpose of completeness note that

roller-to-channel width clearance and channel side wall lay-back

angles (or special configuration) have not been mentioned.

108

INDUSTRIAL TECTONICS, INC.
Arthur S. Irvin Co., Inc.

February 18, 1983

Page 5

Para. 9.3 -."Ball bearing requirements - In addition to general

requirements.listed in para. 9.1,. the following are required

for ball bearings."

Para. 9.3.1 through 9.3.4 - These call-outs, combined with

9.1.12 and 9.1.36 are over specified. For this reason, either

contact angle (9.3.1) or shim thickness' (9.3.4) may be used, but

not the combination of both.

Para. 9 . 3 . 5 - OK

Para-. 9.3.6 - Omit if this text infers race diameters and

tolerances.

Para. 9.3.7 - Add "(if applicable)" and list after 9.3.1.

Para. 9.3.8 - Omit

Para. 9.3.9 and 9.3.10 - Combine: "Ball diameter and grade.

Special sphericity/or lot diameter variation tolerances, if

different from ball grade specifications."

Para. 9.3.11 - Omit

Para. 9.3.12 - OK, except why not combine this paragraph with

9.2.10 and 9.2.11 and list it in para. 9.1?

Para. 9.3.13 - OK

Para. 9.3.14 - Preceed with "minimum."

Para. 9.3.15 - "Preload limits (or nominal value) for bearing

stacks, if applicable."

Para. 9.3.16 - Omit (see 9.3.7)

Para. 9.3.17 - Omit (is part of AFBMA standards)

Para. 9.3.18 - Add: "(ref., applicable only for unsymmetrical

ring(s))."

Para. 10 - OK

Para. 10.1.1 - Change to: "Hardness, heat treat verification

(charts), metallurgical test results."

Para. 10.1.2 through 10.1.12 - OK, except replace "magniflux"

with "magnetic particle inspection"; add "eddy current inspection"; omit word "bead"; and in ALL cases, add: "as required."

Para. 10.2 and 10.3 - Delete. As previously suggested, reference

should be made to the requirements of MIL-Q-9858.

1 Q g INDUSTRIA L TECTONICS, INC.
Arthur S. Irvin Co., Inc.

February 18, 1983

Page 6

Para. 11 through 11.10 - Delete in its entirety! There is no

justifiable reason why a material specification should be added

to or made a part of a specification describing ball and roller

bearings. We suggest existing material specifications be used

rather than inventing and imposing yet another specification.

Restricting all bearings to M-50 does not appear desirable from

a technical or economical viewpoint.

Para. 11.11 through 11.11.2.13 - OK

I hope these comments, while not all positive, will be accepted

as constructive critique and will assist you in the preparation

of your next draft.

Sincerely yours,

Hans R. Signer

Chief Engineer

HRS:1m

INDUSTRIAL TECTONICS, INC.
INDUSTRIAL TECTONICS, INC.

18301 SANTA FE AVENUE, RANCHO OOMINGUEZ, CA 90224 • (213) 537-3750

MANUFACTURER S OF PRECISION BALLS AND BEARING S

bearing division

March 9, 1983

Arthur S. Irvin Co., Inc.

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

Specification - Optimized Bearing Utilization

Industry Coordination Meeting on Contract NAS3-23520

Gentlemen:

A preliminary draft of the "Optimized Bearing Utilization"

specification was presented at the meeting.' Accordingly, my

comments are of a conceptual nature only.

As a first action item you may want to meet'with Dr. Jim Dill

of WPAFB to discuss his effort which, to my knowledge, was

sponsored by the joint chiefs of staff. His study defined the

various levels of bearing restoration and the associated

nomenclature. Your OBU spec then should be structured to

clearly define the desired levels of activities.

Even though not stated in the present text, I surmise that it is

the purpose of your specification to give instructions to the

Government Rework Facilities, i.e., overhaul personnel, on exactly

how bearings are to be cleaned, evaluated, "serviced" and eventually returned for use. In any event, the multitude of bearing

types encountered should be addressed. For instance, the specification could be organized reflecting a "flow chart" for the

distinctly different tasks applicable to ball bearings, roller

bearings, separable and non-separable bearings.

Cleaning: Caution must be exercised when ultrasonically cleaning

assembled bearings. Depending on the bearing type and the level

of contamination, washing with solvents.or degreasing may be

preferable. High levels of filtration and cleanliness should

apply only to "final cleaning," prior to lubrication and reuse.

Vibratory cleaning and/or honing of disassembled bearing components may be considered as being viable options.

Preliminary Visual Inspection: Include severe corrosion as being

cause for.immediate rejection.

I ll
Arthur S. Irvin Co., Inc.

March 9, 1983

Page 2

NOT Evaluations: Presumably the methods listed are meant to be

available options to be selectively used where best applicable.

The test methods, limits of acceptance and the disposition of

the bearings should be further discussed. The specification

should give guidance as to when a bearing can be reused as is,

must be scrapped, or if a rework is advisable what level of

rework should be applied.

Visual Examination of Retainer Wear Area: How do you propose to

measure wear of .00025 inch per surface on retainer pockets and

lands? Typically, the plate thickness of retainers is .001

to .002 inch. Stripping and replating is necessary when the base

metal is visible due to wear or when the plating is damaged by

chipping or blistering. Retainers that are not plated can be

used until distress on the functional surfaces is visible.

Determination of the Need for Restoration: We recommend that no

race grinding be performed in army overhaul depots. A military

specification, MIL-B-58105, is already in existence, describing

the process of bearing restoration by grinding. While that

specification is quite comprehensive and well conceived, it also

requires certain revisions. For instance, we recommend that

restoration by grinding be preceeded by an engineering analysis

of the bearing geometry. That specification should further be

expanded to permit replacement of individual bearing components

in addition to rolling elements on bearing designs where this

approach may be either technically or economically more desirable

than regrinding both inner and outer rings. Standard size rather

than oversize rolling elements can then be used as replacement.

Marking of Processed Bearings: We suggest that appropriate

marking be applied to the bearings, indicating the overhaul

activity performed.

Sincerely yours,

Hans R. Signer

Chief Engineer

HRS:1m

INDUSTRIAL TECTONICS, INC.

112
Phone (616

286

)

0

 755-374

 McCracken

1 Tele

, P.O

x

.

 22-843

 Box 68

6

8 ~KAYDO _ N

Muskegon, Michigan 49443 UURPORATIU N

February 8, 1983

Mr. Arthur S. Irwin

Arthur S. Irwin Company, Inc.

Driftwood

Bemus Point, NY 14712

Subject: Industry Coordination Meetings on NASA Contract NA53-23520

REVIEW AND CRITICAL ANALYSIS ROLLING ELEMENT BEARINGS FOR

SYSTEM LIFE AND RELIABILITY

Dear Mr. Irwin:

Having attended the first two sessions of subject meetings held at the Cleveland

Airport Holiday Inn on January 24 and 25, 1983, I offer the following recommendations in response to your request.

Recognizing that the primary motivation for the specifications for procurement

of new bearings and for rework, restoration, and refurbishment of used bearings

was the recent short supply of M-50 bearings we would point out that a similar

situation existed relative to 52100 and carburized bearings. And because for a

variety of reasons designers will continue to specify bearings and bearing/gears

of 52100, 9310, 8620 and other steels, we strongly urge that either the

specifications be broadened to include them or that companion specifications for

these bearings be written.

In either case, we laud those from TSARCOM and NASA/LEWIS who recognize the

benefits to be derived from the existence of such specifications and are pleased

to participate in their review. Confirming and supplementing the verbal statements made during the sessions just held, we submit the following comments.

Hopefully, to keep this brief for your benefit I have omitted the many suggestions

on which I did not make the initial statement and which proved to be non-controversial

since in those cases either I assume Bill Derner made appropriate notes or others

will comment, or both.

A. Procurement Specification

2. Add documents listed in 11.3 and omitted here. Also add

specs, for 52100 (AMS 6440 and 44) and carburizing race

materials and for steel cages (AMS 6414 and 15), bronze

and silicon iron bronze cages and specs, for quality

(MIL-Q-9858) and inspection (MIL-I-45208).

3.2 Substitute requalification required only if major change

in product or process. Add Q.C. audit required and

first article inspection again required if over 1 year

since manufacture of previous order.

FOLLOWING ARE OUR REGISTERED TRADEMARKS - YOUR ASSURANCE OF KAYDON QUALITY.

KAYDON Endura-Slim Lami-Seal Endurakote wireX

Reali-Slim Reali-Seal Lami-Shield Thin-Shell Bowser

113
KAYDO

CORPORATIO

N

N

Arthur S. Irwin Company, Inc.

February 8, .1983

Page 2

4. Amend to provide for "first article inspection" where

sampling is permitted.

7. Amend to state the basic purpose. Forbid changes which

would have an adverse effect on the end-product; require

that all changes be reported to avoid innocently committing

the former.

8. Substitute "equipment manufacturer" for "cognizant DCAS

inspectors".

8.2 Amend to essentially the same as 7. above, substituting

"process deviations" for "changes".

9. Qualify such that listed items must appear on drawings

only "if applicable and required to assure proper function

of bearing".

9.1 Separate and identify those items that are "for engineering

reference only" and such are not subject to the inspection

process: 9.1.5, 8, 9, 10, 11, 15, 21, and 47, also 9.3.9.

Omit 9.1.17 arid 46, the latter to be included in Purchase

Order to properly provide for variety of requirements not

related to the bearing or its application(s).

Add surface defects allowed (nicks, dents, scratches, etc.)

Add microstructure requirements statement.

Add limitations on retained austenite.

Add decarburization limits on non-functional surfaces.

Add any NDT requirements.

9.2 Add:

Roller roundness

Limitations on roller drop in cage

Roller/guide flange clearance

Guide flange configuration detail

Omit either 9.2.12 or 14 (duplication)

114
KAYDO

CORPORATIO

N

N

Arthur S. Irwin Company, Inc.

February 8, 1983

Page 3

9.3 Restate 9.3.11 to "Grain flow orientation, when important

to satisfactory bearing performance, shall be as negotiated

between equipment manufacturer and bearing supplier.

NOTE - This statement should also be added to 9.2 - or

both statements omitted and a single statement

added to 9.1.

Redefine 9.3.17 as "maximum out of parallelism of ball groove

and face(s)".

10. Substitute "equipment manufacturer" for "cognizant military

authority as delegated thru DCAS".

10.1 Add "and Processes" to title.

Substitute "magnetic particle inspection" for "magnaflux".

Add "eddy current inspection".

11. Material - See the second paragraph of our letter.

11.6.4.1.2 Change Severity for Class 3 Radial Segregation to B

Change Severity for Class 4 Ring Pattern to C to agree with

AMS 6491.

11.6.5 Change grain size to 7 or finer to agree with AMS 6491.

11.6.6 Change Includion Rating to:

Type

Thin

Heavy

A

1.5

1.0

B

1.0

1.0

C

1.0

1.0

D

1-5

1.0

to agree with AMS 6491.

11.6.6.1 Add appropriate statements for Types A thru D Heavy.

11.11.2 Add "Results of test for response to heat treatment" as

Item 14.

115
KAYDO

CORPORATIO

N

N

Arthur S. Irwin Company, Inc.

February 8, 1983

Page 4

B. Utilization Specification

CLEANING: Add precautionary statement; ultrasonic cleaning of

assembled bearings can result in serious damage to vital

surfaces. Recognize and provide for use of other cleaning

methods such as "force flushing".

PRELIMINARY INSPECTION: Provide for tang-type and line indent-type cages.

NOT EVALUATION: Add noise testing if performed on bearings originally;

this would have to be done before dismantling, obviously.

Change first paragraph after "examination" to "and/or

others required to qualify parts for further use".

Change "or" to "and" in second paragraph.

DIMENSIONAL VERIFICATION: Regarding grinding, plating, and regrinding

to restore I.D.'s and O.D.'s to original dimensions we

recommend:

1. Leaving stock removal amount up to contractor,

specifying instead that plating after grind be

tightly bonded and uninterrupted.

2. Specifying baking after plating to prevent hydrogen

embrittlement.

3. Specifying the plating material(s) allowed. We

would limit this to hard chrome.

4. Call out the applicable Government Specification(s).

We would call out QQ-C-320, Class 1.

STANDARD RACE GRINDING STOCK REMOVALS:

Add honing as a stock removal method.

Change stock removal callout to .003 inch maximum per side.

If the intent is to standardize on roller size, state this

directly. No one value of stock removal will suit all

situations.

. Amend second sentence (Care must....) to require same control

as for new bearings.

116
KAYDO

CORPORATIO

N

N

Arthur S. Irwin Company, Inc.

February 8, 1983

Page 5

ASSEMBLY: Amend third sentence to, "all parts will be coated with a

auitable material as called out in the procurement

document".

MARKING, CODING, AND SEGREGATION FOR PACKAGING:

Regarding marking and coding, this should provide for

inclusion of time in service, identification of facility

doing the work, and maintenance of traceability. Regarding.

packaging, as with new bearings this is better provided for

in the purchase document.

Art, is there are questions about any of these recommendations of the supporting

arguments for them, please give us the opportunity to discuss them further with

you or Bill Derner. It has been a pleasure working with you on this project and

I look forward to the next meeting on May 17 and 18.

Sincerely,

KAYDON CORPORATION

Richard F. George

Vice President-Engineering

cc: T.A. Bushar/K.D. Harestad/R.A. Laferriere

M.L. Hoard/P. VanGennep

117
JC^^ ©

East Hartford, Connecticut 06108

February 2t 1983

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, New York 14712

Attention: Mr. Arthur S. Irwin

Subject: Industry Coordination Meeting - Jan. 24 & 25, 1983

NASA Contract NAS3-23520

Bearing Specification - Comments

Dear Sir,

The subject meeting was interesting and extremely informative. Mr. Bill

Derner should be commended on the manner in which he conducted the

sessions. I feel that the information exchange should prove to be

beneficial to all of the participants. Because of the wide cross-section

of representatives (bearing, engine, helicopter manufacturers, NASA, Army

etc.) the meeting presented a rare opportunity to discuss the varied

aspects of bearing manufacture, procurement and utilisation.

Per your request, I have listed a few additional items and/or comments

which you may want to consider for inclusion in your proposed specification. The items are summarized in the attachment. I have also

included my P&WA expense report and my mail -stop for future correspondence.

Sincerely yours,

PRATT & WHITNEY AIRCRAFT GROUP

Commercial Engineering

W. R. Ironside

mb

enclosures

118
Attachment

Bearing Specification - NAS3-23520

Comments:

1) Section 3, Qualification

. The cage vibration modes should be established to determine if

there are any driving frequencies (ball passing, gear mesh,

etc.) that coincide with the cage natural frequency.

2) Section 8.2 (Process Deviation Approval) and 10.2 (Material Review

Board)

. A reasonable time limit should be established for approval or

response.

3) Section 9, Drawing Check List - Add:

. Roller drop

. Roller flat centrality/crown drop uniformity

. Roller end concavity

. Split inner ring ball bearing - radial mismatch in groove at split

faces (control to prevent ball from contacting the split face edge

during load reversal).

4) Section 9.1.47, Installation Data

. Some bearing part numbers are used in several different locations.

The applications have a wide range of environments and/or

operating conditions (speeds, loads, thermals, lubrication, etc.).

It would be difficult to place all of this information on a

bearing drawing.

5) Section 10.1, Inspection Methods

. Add eddy current.

6) Cage Design/Refurbishment - The bearing spec, should state that a "snapin'' type roller retention scheme is preferred over "bent tang" (if

assembly permits). This would allow the rollers to be removed for roller path

inspection and eliminate the concern about tang re-bending and breakage

during refurbishment.

W. R. Ironside - Mail Stop 163-10

Pratt & Whitney Aircraft

400 Main Street

East Hartford, CT. 06108

119
SPECIFICATIONS

FOR

BALL AND CYLINDRICAL ROLLER BEARINGS

120
-I"

«

v

o

6. Rejection - All components and assemblies which are rejected shall be pas»-

Tpgney^.Ty *AmM fi art _ nr rl i- mnii

or rework can only be considered after Quality/4*«

Review Board recommendations I are studied and approved by the cognizant military

4, authority. I I v> P r « <, *• i \ r*-\» «.< v

7. Change Control - There may be no change'to the design, material, tolerances,

processing, quality control plan, procurement sources^ ho at "tfftat, inspection

standards, nor shop operations or_routings without(the wcpfooo «filHen pmL'qr*'

aMHEOSZg. of the" brigihal" contractor or the cognizant military "authority.")

"7.1 Change Control 'Approval - Any request for change shall be"the responsibility of the vendor to submit prior to the initiation of work on the

contract and approvals must be on hand prior to the start of the operation on

which the change is to be made. v

S. Process and Inspection Approval - Sasdbias^D the award of a production contract,

.".11 process operations and all inspection-procedures and details will be evaluated and confirmed by the cognizant DOA^ inspectors -to insure compliance with

currently accepted aerospace industry standards. This will include all destructive and non-destructive methods, as well as quality control f1 pr»°i•*""* '""liltrl^.

_fri "QP

8.1. Process and Inspection Changes - As required in paragraph 7, no alteration or change in any operation, process, or inspection procedure may be

"ir.de without prior review, evaluation, arid approval by the original approval

authority.

8.2. Process Deviation Approval - Deviations from approved processes or

inspection standards require formal Material Review Board action and submission

to the cognizant authority prior to commission, omission or deviation. Written

•••\pproval is required prior to any deviation by the vendor.

c>. Drawing Requirements - All drawings pertinent to the procurementAof these

critical bearings shall include the essential 'data and callbuts in a format

that complies with the following checklist. It shall be the responsibility of the

original contractor to update his drawings for use by TSARCOM as directed in

his current or follow-on contracts. That information not specifically noted on

the checklist but essential for definition and control of significant characteristics will also be provided by the contractor in compliance with the intent

of this specification. These drawings will be completed in a manner prescribed

by ANSI YU.5.

9.71. Drawing Checklist

9.1.1. Type of bearing

9..1.2. Bore

-9.1.3. O.D.

9.1 Jy. Width

i 9.1.5. AFBMA _

rolling elements per row

9.1. 7.; Number of rows of rolling elements

fl 9.1.8. Basic dynamic radial load rating per AJBMA

A- 9.1.9. Basic static radial load rating per AFBMA

driftwood. R. F. D. I

Bomus Point, NY 14712

121
3.

9.1.10. Basic .dynamic thrust rating where applicable

9.1.11. Basic static thrust rating per AFBMA where applicable

— 9. 1.1 2 Jj Radial internal clearance (total)

9.1.1 3« [.Gage load for determining radial clearance

— 9." .14. Diametral clearance for retainer-to-piloting ring

9.1.15. Diametral clearance for retainer-to-non-piloting ring

9.1.16. Retainer overall width C****') O ; c»««. p.»ot>^ *<;<"< »-ct\$-

9.1. 17. TTiliuncr onf fnrr pmTTnli im «.<«•.€,*•"«• ^;

9.1.18. Retainer bore-to-O.D. concentricity

— 9.1.19. Pilot-ring io eating-diameter concentricity to pilot

diameter __ ^___^" "fc^-^^^wM^^^^efcX*.

- 9.1.20. Rolling element to retainer pocket clearance ^°"*'

 ref

9.1.21. Rolling element_cpmplement pitch diameter ^

9.1.22. Rolling elemen^clearance from tang or retention device

in the operating (mounted) condition

— 9.1.23. Retainer material and hardness

9.1.24.. Retainer plating required and thickness (per AKS 2412

—...9.1.^5. Roto-inci* plating cornoi' build- -up- •fcolora»oo •

— 9-rJrgfrr -Rotninor landirlth in antrUe-b with »ho pi-lo*iBg

— '9.1.23. Surface finish roughness A-A for rolling contact surfaces

9.1.29. Surface finish roughness A-A for mounting surfaces

— 9.1.30. Surface finish roughness A-A for retainer and retainer

piloting surfaces. 4,Ppl>co.b'«-

9.1.31. Lobing, waviness' and chatter tolerancesAto operating

and mounting surfaces. Poalc *to valloy limit c to bo givon for a

-j^aige uf leboo por oir.aumfoponuu uJ fi'uau 9 lu 99.

pecial aui-faea tgrtm-c moJifl

^.1.33. surface' treatments J^ coating^ required

• — 9.1.34. Assembly cross corner dimensions required:^?nf

— 9.1.35. Flushnens requirements (where applicable)

9.1.36. End play or end float limits (•*>«.»•)

— 9.1.37. Gage load for end play check

—9.1 .38, Material for rings and rolling elements

9.1 .39, Special heat treat require^, (where applicable)

—9 .1 .4-0 . Hardness range required -o^il ^o<"tpo«e»,ri.

9.1.4-1. Bearing operating temperature range and the stabilizatio n

temperature required to provide against growth of elements or

undesirable transformation products

""9.1.42. Bearing material procurement, inspection and evaluation

requirements to insure cleanliness, grain control, sufficiency

of working after the ingot is formed and to provide documentation

for traceability. (See 11 )

— ^,1.4-3-. Outer ring/inner ring ript.rril- tn -prmrent nrnnp, m>nnm ..

• — fnrimlnnl mf*tiii7n nr

P. 9.1.44-. Description of details for special mounting or removing

procedures

ARTHUR S. IRWIN CO. INC. t. , . Technology Consultants continued next page

Driftwood Center

Bemu.? Point. NY 14712

122
ARTHUR S. IRWIN CO. INC. „„,. „„„„

Technology Consu'tsnts "«WIV/»L p^gg fo £.

Driftwood Center »F pQQR Q

 c

S«mus Point. NY 14712

 U"fll

 '

——9.1.4.5. Identification- requirements.

•'^lUaij^u^ii ii.1n

.9111461 r-aoltagip.g requirementgft, 9.1.47. Installation data ,

9.1.47.1. Housing fit, material & wall thlcloaess

9.1.47.2. Shaft fit, material and- wall thickness

9.1.48. Requirement for all evidence of nital etch staining

to be removed from rolling contact surfaces, tf

-0,1 f,n , VnT^n»i^ ^^.,^1^1 j-miiyt'iF 1ni|i.t.li of rni:

9.1.50. 6-tecdasd Heat treat yroooduro or specification required

9.1.51. Inner ring high point 'to be identified, ^.r^v/.vc*

9.2. Cylindrical Bearing Requirements - In addition to the general requirements listed in paragraph 9.1, the following are required for cylindrical

bearings .

— r 9.2.1 . Roller diameter

— 9.2.2. Roller length

— 9.2.3. Roller crown radius, ev

..- 9.3.4. Roller effective loge^fe , . + io tf KA_«, Cfcnfv-cJ.f-(

^ -V l*.r ic-jrh*"*- j crown dropTcoordinates/-

9.2.6. Roller end squareness

— 9.2.7. Roller corner radius runout with respect .to ijoller cylindrical section, 14 **«N »*•*.*. «A,tj.i.f r/ i

^ + 9.2.8. Roller corner dimensions "**-* *' *"^* °""c*

6° 9.2.9. Roller end face finish A-A

 P"^c

 Ur

( 9.2.10. Cage balance tolerance and balancing speed > |f

^ 9.2.11. Coca diomotcg feii- la eating durfaig .

9.2.12. Diameter variation within one roller set

"V 9.2.13. Requirement, if any, for roller complement to be retained

in the cage when removed from its associated ring

?.?. Vn Ttnllnr rnnplamont fl,l ........ ?n' i 11- n InUhin iniiMini l

9.3. Ball Be^vring Requirements

9.3.1. Contact angle/uvk<noo<>it«a..>

9.3.2. Inner ring groove radius as a percentage of ball diameter

9.3.3. Outer ring groove radius as a percentage of ball diameter

R^ 9. 3. A. Shim thickness to be used when grinding split rings

9.3.5. Rnnout of split ring contact face with respect to the bore

of the split ring , i-f ve^»ircA.

9.3.6. Ring groove diameter end tolerance

— 9v3->7^_Gage load for noacur-ing contact angle

P- ••9,J.Q.

 chlm angla ^hiry> *A'*

9.3.9. Ball grade, vyf.

--- 9.3.10. Ball sphericity and ball complement diameter variation

required ,-& >^•«^>'^r«•«i• « rf

9.3.11. Ring grAin orientation to be substantially parallel to

groove surf aces/[ «b >« v»««joti1atcA>)

9.3.12. Cage balance required and balancing speed range a^aag-- ',

****h diameter for locating during balancing , *•* vv^oi***. .

9.3.13. Identification required to insure alignment and loadsharing of matched sets of -multi row bearings

continued next page ............

123
ORIGINAL PAGE IS

ARTHUR S. 1RW1N CO. INC. QC PQQR OUALnv

onsultants

 vr

Technology Consultants ruu«yu«UIT

 vr

 ruu«yu«UIT 5.

Driftwood Center

Bemus Point. NY 14712

9.3.14-. Race depths as « percentages of ball diameter

9.3.15. Bearing preload, if «jjt *•» t»hc*.j»)«..

— y*J. 1«r uunuacu arrg±e

3 TJn-n r-rnn

8-. Otjadaff iof-b, ait

P1I10

Lt

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-evoa

aujion gago jioaa

vu fruinriwmUR*-<tad-£ec«>-o£Ldug.

10. Inspection Processes - All inspection methods and processes must be approve*?

and certified by the cognizant military authority as delegated through DCAS.

10.1 Inspection Methods to be certified

10.1.1. Hardness, metallurgical structure, austenite determination

and material stabilization verification

10.1.2. Decarburization determination

10 o 1.3. Grinding burn detection and evaluation

10.1.4. M"C

10.1. .5. Visual defect examination and evaluation.^

10.1.6. Ultrasonic inspection for subsurface dejects

10.1.7. Fluorescent penetrant inspection for surface defects

10.1«8. Surface texture evaluation and control

10.1.9. Plating process control

 vand verification

10.1.10. Coating process control and verification

10.1.11. Shot bsad peening process control and verification

10.1.12. Quality control verification and traceability

10.2. Material Review Board

10.2.1. There shall be provided a formal Material Review Board

procedure and activity which shall be verified by the procuring

agency representative and it shall be presented to the cognizant

military authority for approval in writing.

10.2.2. Material Review Board members shall be certified to the

DCAS representative and shall not be replaced. without acknowledgement by the cognizant military authority.

10.2.3. The Material Review Board shall be the only representative

of the contractor authorized to communicate with the DCAS representative and request deviations.

10.3. Inspection Standards

10.3.1. Standards of acceptance for all inspection processes to

include dimensional masters shall be traceable to the National

Bureau of Standards or shall be proved equal in control and

verification to industry standards.

continued next page

124
Data 1s required to permit review of bearing design and analysis of

performance. Such may be presented 1n Appendices, (separate sheets), or on

the face of bearing drawings, clearly designated as not regularly requiring

Inspection to the level applied to production bearings:

9. Drawing Requirements - The desired characteristics of high technology

bearings are defined by engineering drawings and specifications called out

on such drawings. It 1s of advantage to TSARCOH that these drawings be

prepared to a standard format 1n the manner prescribed by ANSI Y 14.5.

However, existing drawings will serve the desired purpose, 1f they are

complete and Include the following:
ARTHUR S. IRWIN CO. INC.

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

11. Material - Rings and Rolling Elements

Type: AISI M-50 HIGH SPEED STEEL. VACUUM INDUCTION MELTED AND VACUUM ARC

. REMELTED MATERIAL FOR BALL AND CYLINDRICAL HOLLER BEARINGS

11.1. SCOPE:

11. .1 This specification covers High Speed Forgings, forging stock, mechanical

tubing bars, rods, and coils to be used ir the manufacture of high quality

ball and roller bearings.

11.2. PROCESS:

11.2.1 The steel/electrode shall be produced employing vacuum induction melting

process during initial melting, followed by remelting employing vacuum arc

remelting (consumable electrode) process. The initial electrode shall be both

melted and cast under vacuum.

11.2.2 For manufacture of bearings in this category, the bearing supplier shall

purchase, control and test raw material to this specification and certify

conformance thereof.

11.3. REFERENCED SPECIFICATIONS:

The following documents are integral parts of this specification. (Use latest

issue of each.)

11.3.1 Aerospace Material Specifications:

AMS 2808 Identification, forgirgs

AMS 2259 Chemical check analysis limits

AMS 2300 Premium Aircraft-Quality Steel Cleanliness

Magnetic Particle Inspection Procedure

AMS 2251 Tolerances, low alloy steel bars

AMS 2253 Tolerances, carbon and alloy steel tubing

AMS 2310 Qualification sampling of steels, transverse

tensile properties

AMS 2350 Standards and test methods

AMS 6491 VIM-VAR AISI M-50 steel

ftfKT-37i" Co«ft<r») of •fev«tv\<3$ - £'v-jf oLvfielt initfOttlcm

11.3.2 American Society for Testing and Materials:

ASTM E112 Estimating the average grain size of metals

ASTM E350 Chemical analysis of carbon steel, low alloy steel,

silicon electrical steel, ingot iron and wrought iion

126
ARTHUR S. IRWIN CO. INC. OPtfMiuii. 7

Technology Consultants "K/GIWAL PAGE l«

Driftwood Center OF PQQP QlM I ITW

Bemus Point, NY 14712 " DUALITY

ASTM 5&W Macro etch testing of consumable electrode vacuum

arc remelted steel bars and billets

11.A. CHEMICAL COMPOSITION:

11.4.1 The steel shall conform to the following requirements as td Chemical

Composition; r St* 4 / ,\rS,t tf (AJ j-pp I, (,»4J<~ »*»t ftcfj

/" Element

\ Carbon /' 0.80 - 0.85 ^Chromium /^4.00 - 4.25

J Manganese \ 0.15 - 0.35 ( Molybdenum \ 4.00 - 4.50

] Phosphorus ) 0.015 Max. \ Vanadium J 0.90 - 1.10

/ Sulfur J 0.008 Max. < Nickel < 0.15 Max.

Copper / 0.10 Max. Cobalt 0.25 Max.

V Silicon I 0.25 Max. ( Tungsten I 0.25 Max.

11..4.2 A chemical analysis shall be obtained and reported for the master heat for

all elements listed in Para. 4.1. In addition to the heat analysis, each

remelt V.A.R. ingot shall be analyzed for carbon and manganese.

11.4.3 Check analysis may be made by the purchaser in accordance with the latest

revision of ASTM 59 and AMS 2259 with the exception that check limits for

carbon shall be -0.01 under min. in lieu of ±0.03 per AMS 2259.

11.5. FORM AND CONDITION:

The material shall be supplied in annealed and centerless ground or turned with

a surface finish of 125 RMS or better as necessary to perform immersion ultrasonic

test requirements per Para. 6.7. Bars or forging rounds shall have a max.

hardness of BHN 229.

11.6. QUALITY TESTS:

11.6.1 Material shall be uniform in quality and condition, clean, sound and free

from foreign materials and from surface and internal defects detrimental

to fabrication or to performance of parts. The material shall have substantially uniform macrostructure and grain flow.

11.6.2 The manufacturer shall be held responsible for the quality of the material

being furnished and shall make the necessary tests to insure this quality.

127
ARTHUR S. IRWIN CO. INC

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

1*1.6.3 Magnetic Particle Stepdown Test;

11.6.3.1 Specimens shall be taken from 4 inch square billets

representing the tapand^tam of<>•*& ingot.

11.6.3.2 Specimens shall be inspected^ in accordance with AMS 2300.

11.6.4 Macroetch;

11.6.4.1 Billet Inspection: Transverse disc sections shall be cut from both

ends of all billets or bars prior to rolling into bars or extrusion

into tubes. The samples shall be etched in accordance with ASTM A604

in hot hydorchloric acid and water (1:1) at 160-180°? for sufficient

time to develop a well-defined macrostructure.

11.6.4.1.1 Samples shall show freedom froai pipo, porosity, inclusions,

segregates or segregation.

11 i&. 4.1.2 Samples shall exhibit macrostructure equal or better

than the following macrophotographs of ASTX A604:

Condition Severity

Freckles A

White Spots A

Radial segregation A

Ring pattern A

11.6.4.2 Finish Product Inspection:

11.6.4.2.1 Transverse disc sections shall be removed from both ends

of all bars and tubes and etched in accordance with ASTM

A604 in hot hydrochloric acid and water (1:1) at 160-180"?

for sufficient time to develop a well-defined macrostructure.

11.6.4.2.2 Samples shall show freedom from pipe, porosity, inclusions,

decarburization,-seams^internal or external defects.

11.6.4.2.3 If samples are representative of material prior to centerless

grind/turn operation, any surface defects, seams or decarburization must be within the stock removal zone.

128
PRATT & WHITNEY AIRCRAFT GROUP

GOVERNMENT PRODUCTS DIVISION

Mr. W. E. Poole

M/S B-162

P. O. Box 2691

West Palm Beach, Florida 33402

14 February 1983

Mr. Arthur S. Irwin

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, New York 14712

Dear Art:

It was a pleasure to see you again. As you requested at the Cleveland

meeting, I am sending you my comments on the bearing specification proposed by ASICO for TSARCOM. My comments are fairly general in nature and

are intended to show areas we feel are unnecessary or are restrictive to

the point of serious cost or delivery impact. My comments are referenced

to the paragraph numbers in the proposed specification.

PARAGRAPH NUMBER

3.

4.

5.

6.

7 & 8.

UNITED

TECHNOLOGIES

Remove the phrase "statistically significant"; any

quantity can be statistically significant but confidence may be low. Where feasible, qualification

should be in the actual application. I suggest

something like: "Quantity required for qualification and the qualification test to be jointly agreed

upon by the prime contractor and Government."

As now written, this can be extremely restrictive.

I suggest you delete the first sentence.

Delete, this is redundant with Paragraph 3.

Don't permanently mark rejects until scrap decision

is made. In this, and most other cases, the prime

contractor should be the reviewing authority because

of his access to the design details and background.

Of course, this is subject to approval by the procuring agency.

These overlap and should be combined, or clearly

separated into design and process changes. Also,

as currently written the supplier has no flexibility

even with details such as grinding wheel speed, feed

rates, etc. These paragraphs have the potential of

being very restrictive; are you sure you need, want

or can afford this control ?

129
Pratt & Whitney fiircraft

Mr. Arthur S. Irwin

14 February 1983

Page Two

PARAGRAPH NUMBER (Continued)

10.

11.

This enormous list of drawing requirements must be

handled with care. This list combined with the 100%

inspection requirements of Paragraph 4 could be a

"show stopper".

It would be better to place responsibility for inspection method approval with the prime contractor. In

most cases the mechanisms are already in place. The

MRB responsibilities need to be split between the

supplier (responsible for undimensioned characteristics)

and the prime contractor (responsible for print and

specification compliance).

Alternate materials need to be allowed; 52100, 440C and

carburizing grades are fully acceptable when properly

applied. Should this bearing spec, include all the

materials requirements ? Perhaps separate material

specifications which are referenced in this spec.

Also, do you really feel that this premium quality

material is required across the board ? I suspect

that AMS spec, materials are adequate for many applications.

I don't have specific comments for the refurbishment spec. Since there

is an active effort by the Tri Services Committee, chaired by Jim Dill,

to do the same job I feel one spec, is enough. In any event, your efforts

should be compatible with the Tri Services project.

I hope this helps your task,

at the next review meeting.

Sincerely,

UNITED TECHNOLOGIES CORPORATION

PRATT & WHITNEY AIRCRAFT GROUP

Government Products Division

I'm looking forward to seeing you again

cc: E. M. Beverly

R. L. Thomas

William E. Poole

WEP/gjt

130
ORIGINAL PAGE IS

OF POOR QUALITY

APPENDIX A - GLOSSARY

AA - Finish;. Arithmetic Average - a numerical value of surface finish

obtained by measuring the vertical distance from the mean line of an irregular surface to the profile in the same manner as with RMS, adding

these measurements and dividing by the number of measurements.

ABEC 1, ADCC 3,'ABEC 5, ABEC 7, ABEC 9: Annular Bearing Engineers

Committee (AF8MA) designations indicating degrees of ball bearing precision.

_Absolwte-F7ft*«K—Ei'*»rfi *gnnhlr nf f'iMiiinn nut iiin n Mir pi

with no-f

Active Surfaces: The contact areas on the rings and rolling elements

that are generated as the bearing is rotated.

AFBMA: Anti-Friction Bearing Manufacturers Association

Angular-Contact Bearing: A type of ball bearing whose internal clearances

and ball raceway locations are such as to result in a definite contact

angle and predetermined relationship of inner to outer ring faces, W»*w a

ANSI; Americal National Standards Institute

Antifriction Bearing: A bearing using rolling elements such as. balls, rollers

or needles.

AQL: Acceptable Quality Level is a value specified for a type or group of

defects characteristics of an item or product. The specified AQL value

(example - AQL of 0.4) is referred to in the appropriate sampling plan

table of MIL STD 105. The number of defects for each AQL is then obtained that will determine whether to accept or reject the lot.

Axial Clearance: see End Play

Axi-cd Load (Thrust): .Pressure applied to the bearing parallel to the bearing

axis.

Back-to-Back Assembly: A duplex pair of matched ball bearings with

outer ring backs adjacent.

Ball Complement: Size and number of balls used in a baM bearing.

Bearing Axis: The imaginary center line about which the outer or inner

ring will turn.

Bearing Stack: Matched multiple assembly of two or more bearings.

ARTHUR S. IRWIN CO. INC.

Bemus Point, NY 14712

131
Bore Diameter: Inside diameter of inner ring.

.Sec/. Inr""- Q-^g. Surface 01-00 of bore diameter. ^—

Bore, Outer Ring: Inner diameter surface or land area.

Boundary Dimensions: Dimensions for bore, outside diameter, width

and corner.(sj.

-Buiiiii,li.—A luslfef'Or poHsh un a auifaie uy friction or rubbing contact.*

Cage (retainer, separator): A device, parfiaHy surrounding the rolling

elements and traveling with them, with themain purpose of spacing the

rolling elements in proper relationship to each other.

Centrifugal; Moving or acting in a direction away from a center or axis.

Clearance, Axial: see End Play

Clearance, Radial; Radial internal clearance is the total diametrical movement of the undamped ring when the specified load is reversed.

Cone: The inner ring of a tapered roller bearing.

Contact Angle: Angle between plane perpendicular to bearing axis and

line drawn between centers of contact of balls to inner and outer ring

raceways.

Convex: A surface that is curved or bulged outward in the center.

Corrosion: A process which destroys the metal by chemical or electrochemical action and converts it to an oxide, hydroxide, or sulfate compound.

Crack: A break, fracture, fissure, crevipe or separation in the structure

of the part.

Critical Defect: A defect that judgment and experience indicate is likely

to result in hazardous or unsafe conditions for individuals using, maintaining,

or depending upon the product; or a defect that judgment and experience

indicate is likely to prevent performance of the tactical function of a

major end item such as an aircraft, missile or space vehicle.

Crowned Roller; Having a very large radius profile on both sides of a

straight cylindrical center section to provide a modified line contact

with the raceways.

Defect: (discrepancy) Any deviation of a part from specified requirements.

ARTHUR S. IRWIN CO. INC

Technology Consultants continued next page

Driftwood Center

TIUS Point. NY 14712

132
.-V^e -7-

Diametral Clearance: see Clearance, Radia!

Dimensional Stability: The degree of stability that hardened steel may

have to resist growth or permanent expansion ( a function of the amount of

retained austenite.)

Duplex Bearing: Matched set of two preloaded bea'rlngs.

Dynamic Balance: That condition in a rotating body where the mass axis

are coincident or the same.

Eccentricity (radial runout): Occurs when the center of one circular surface is not coincident (the same) as the center of another surface. Ex:

Nonuniform thickness between the bore and the ball groove of an inner

ring.

End Play (Test): The bearing is to be lubricated with liqht oil and one of its rings

clamped to prevent axial movement, the specified reversing measuring

load is applied to the undamped ring so that resultant movement of that

ring is parallel to the bearing axis, the end play is the total movement

of the undamped ring when the load is applied fl rst in one direction and

then the other.

Flaking: A condition.of advanced fatigue where small nieces of metal are

loosened from the base material.

Fluting: A form of pitting in which pits occur in a regular pattern so as

to form transverse grooves or flutes in the raceway.

Fretting ( fret wear, fretting corrosion, false brinelling): The rapid abrasion that occurs at the interface between contacting, highly" loaded metal

surfaces when subjected to vibratory motions or low amplitude. Usually

accompanied by the formation of oxides of the abraded metal.

Galling: The transfer of material from one surface to another during

sliding contact.

Groove Runout with Reference Side, Inner ring: see Raceway Runout with

Reference Side, Inner Ring

Groove Runout with Reference Side, Outer Ring; see Raceway Runout with

Reference Side, Outer Ring

Hardness: Resistance of metal to plastically deform, determined by indentation.

Height of Raceway Shou!der: Vertical distance from bottom of raceway

ARTHUR S. IRWIN CO. INC.

Technology Consultants continued next page

Driftwood Center

Bcraus Point. NY 14712

133
Page -8-

to inner ring outer diameter or outer ring diameter (same as race depth).

Inclusion; A-void, discontinuity, or solid foreign particle in the molecular

structure of metal.

Inner Race: Raceway of inner ring

Inner Ring: The inner component of a bearing.

Inside Diameter: Dimension across center of ring bore. May be used to

express dimension across bore of snap ring, shield, seal, etc.

a.

Inspection: The process of measuring, exemining, testing, or otherwise

comparing the unit or product (bearing) with the requirement.

Inspection, Quality Conformance (CQl): All examinations and tests performed

for the purpose of determining conformance with specified requirements.

Inspection, 100%: An inspection in which Specified characteristics of each

bearing are examined or tested to determine conformance with requirements.

Internal Clearance: see Clearance, Radia!

Lands: The flat surfaces on both sides of the raceway or rings.

Land Riding Retainer: A retainer guided by either the inner ring or

outer ring.

Laps: Discontinuities or irregularities in the material as a result of working.

Lay: Direction of the predominant surface pattern.

Loading Groove (filling slot): Notch in raceway to permit assembly of a

maximum number of rolling, elements.

Loading Groove Bearirc: A bearing of •maximum capacity type, in which

there is introduced, by means of a filling slot or loading groove, more balls

or rollers that can be incorporated in a non-filling slot or Conrad-type bearing.

Lot: This term shall mean "Inspection Lot", a collection of bearings

or kits from which a sample is to be drawn and inspected to determine

conformance with the acceptability criteria.

Lot Size: The lot size is the number of .bearings in a lot.

Major Defect: A defect other than critical, that is likely to result in

failure, or to materially reduce the usability of 'the product for its inARTHUR S. IRWIN CO. INC

Technology Consultants

Driftwood Center

Bcmus Point, NY 14712

134
tended purpose.

Martensite: A phase of steel with a body-centered crystalline structure

characterized by a needle like microstructure.

Matching: Inner and outer rings in duplex sets that are matched for bore t

O.D., and eccentricity, within specified tolerances..

Micron: One millionth of a meter, 1 micron equals .00003937 inches.

Minor Defect: A defect that is not likely to materially reduce the usability of the bearing for its intended purpose, or is a departure from

established standards having minimal bearing on the effective use or operation of theunit.

Nominal: Approximate or rated value.

Outside Diameter Squareness with Side (Test): One side of the outer ring is supported on a flat plate of suitable dimensions (with inner ring free) and helci

against a stop located close to the lower corner of the outside diameter. The

indicator is applied directly above the stop close to the upper corner of

the outside diameter. The deviation from the outside diameter squareness

with side is the difference between the minimum and maximum reading of

the indicator when rotating the outer ring one revolution.

Parallelism of Sides: The difference between the largest and smallest

width of the bearing rings. .

-PeHtettW*. CAlUiuu in the funn uf vuiy Jinull Jtumulc partiUtJ.r*-

Tliu external boundary or surface of a budy;

Pitch Diameter, Rolling Elements: The diameter of the canter line

of the rolling elements.

Pitting: Minute removal of raceway of ball surfaces through fatigue,

corrosion or electrical arcing.

Plastic Flow: Deformation that permanently remains after removing the

load which caused it.

Pocket, Cage: That portion of cage which is shaped to receive the rolJjng

element.

Precision: The degree of agreement of repeated measurements of a quanARTHUR S. IRWIN CO. INC *'**•

 ComPare with

 accuracy.

Technoiosy Consultants

Driftwood Ccnccr continued next page .....................

Ecouu Poiat. NY 14712

135
Page -10-

Preload: Thrust loading a bearing in a unit to increase rigidity. Preloading

decreases deformation and deflection by absorbing the initial portion of the

deflection curve which is steep and increasing at a high rate. The result is

that the deflection is more uniform andi has less magnitude throughout

the loading range.

Processed Bearing: A bearing that has been used and then cleaned, inspected,

gaged, tested and preserved for additional use.

Profile: The contour (external outline) of a surface in a plane perpendicular (right angle) to the surface.

Profile (measured); A representation of the profile abtained by instrumental means.

QCL: Quality Characteristics List

Race: see Ring

Raceway: The contact path of the rolling element ori rings of rolling

bearing.

Raceway Diameter; Diameter of the inner or outer ring raceway of a

bearing.

Raceway, Inner Ring: Track or groove for rolling elements in the inner

ring.

Raceway, Outer Ring; Track or groove for rolling elements in the outer

ring.

Raceway Runout with Reference Side, Inner Ring (Test): Mount bearing on arbor

having a very slight taper (preferably 0.0001 to 0.0002 in. on the diameter

per inch of length). Support outer ring In horizontal position and apply

indicator to side of inner ring. The deviation from groove parallelism with

srde is the difference between the maximum and minimum reading when

rotating the arbor one revolution.

Raceway Runout with Reference Side, Outer Ring (Test): Mount bearing on arbor

havirvg a very slight taper (preferably O.C001 to 0.0002 in. on the diameter

per inch of length). Apply a true ruunning weight to. the outer ring. Support

arbor in a vertical position and apply indicator to side of outer ring. The

deviation from groove parallelism with side is the difference between the

maximum and minimum reading when rotating outer ring one revolution.

Radial Clearance: see Clearance, Radial

ARTHUR S. IRWIN CO. INC

Technology Consultants continued next, page

Driftwood Center

Ecmus Point. NY 14712

136
-1'iRadi'al Load: Pressure applied to the inner or outer rings perpendicular

to the bearing axis.

Radial Runout (Test): Mount bearing on arbor havino. a verv slioht taner (0.0001

to 0.0002 in. on diameter per inch of length). Apply indicator on center of

stationary outer ring. The radial runout is the difference between the

minimum and maximum reading when rotating the arbor one revolution. Corrections should be made for the inaccuracy of the arbor.

Radial Type Bearing: A rolling bearing primarily designed to support a

radial load perpendicular to shaft axis.

Random Sampling:Plan for choosing sample units in a random or nonreaular pattern

for quality inspection.

Rating Life (Lip): Number of hours at a given speed that 90% of a group

of identical bearings will atain or exceed before the first indication of

fatigue cracking or spalling.

RSEC I, RBEC 5: Designations indicating degrees of roller bearing precision.

Roller Bearing Engineers Committee (AFBMA)

Refinish: To restore an existing surface finish without removing all the

existing finish.

Refurbish; To repair bearings by replacement or worn and/or defective

parts and resurfacing any surface including raceways.

Restoration: To return a bearing to original assembly print dimensions

by regrinding raceways and rebuilding with oversize rolling elements.

Detained Austenite: Unconverted austenite phase remaining »in steel after

heat treating to obtain the harder, more fati-gue resistant martensitic steel.

Retainer: see Caae

Rework: The overall procedure for cleaning, reworking, refurbishing, restoring and reissuing of used or rejected bearings.

RFI; Ready for issue.

Rockwell Hardness Test: A test for determining the hardness of a material

based on the depth of penetration .of a specified penetrator into the specimen under specified load conditions.

Roller: Load-carrying rolling element. r^a.^ be c.^1 ;«<!<•»wJ , 4-*f-r«J »

-.Kaped .

ARTHUR S. IRWIN CO. INC.

Technology Consultants

Drifcwooo Center continued next page

Scmus Point. NY 14712

137
ORIGINAL PAGE IS

Of- POOR QUALITY

Roller Aj--..Tibly; Rollers' and cage.

Roller Complement: Size and number of rollers in a tearing.

Roller Diameter: Maximum circular dimensions of straight roHers.

R-oller Length: Distance between the ends or faces of the roller.

Rolling Searing: A bearing using rolling elements such as balls, rollers,

or needles to reduce friction and to support load.

Runout: The amount that one surface lacks of being true with another

surface of the same part.

Runout, Radial: see Radial Runout

Sample: A sample consists of one or more parts drawn from a lot,

the parts being selected at random without regard to their quality.

Sampling Plan: A sampling plan indicates the number of bearings from

each lot which are to be inspected and the criteria for determining the

acceptability of the lot.

Scratches: Linear abrasions on the surface.

Scuffs: A series of small superficial or shallow scratches.

Separable: A bearing assembly that may be separated completely or

partially into its component parts.

Separator: see Cage.

Side Runout, Inner Ring (Test): Mount bearing on arbor having a verv slight

taper (0.0001 to 0.0002 in. on diameter per inch of length). Apply indicator against side of inner ring. The side runout is the difference between

the maximum and minimum reading when rotating the arbor one revolution.

Skew: Slant, twist, nonsymetrical, nonuniform distribution.

Smearing or Pickup: Removal of raceway or ball material die to skidding

contact and its redisposition at another point in the form of smear.

Spalling: Actual removal of material from raceway or rolling element

surfaces in the form of flakes, resulting in cavities - fatigue related.

Split Ball Bearing: A ball bearing having either one or both rings split

across the raceway so as to facilitate assembly.

R s. :R\VIN co. :.\c.

Tcehnojo-y Consultant* continued next page

D.-iftwood Confer

Semus Point. NY 147:2

138
P&ge -13-

Squareness of O.Dii/Bore with Face: The squareness (90° angle) of the face

with the outside diameter/bore of a ring.

Staking: A method of retaining a bearing by disolacina housing material over

the chamfer.

Stains: Surface discoloration.

Standard: A physical or numerical limit which is used as a reference.

(Plug gage = physical and a surface roughness limit = numerical).

Statistical: Of, relating to, or dealing with the collection and analytical

interpretation of numerical data.

Superficial: Effecting only the surface of an object.

Surface Texture: Repetitive or random deviations from the nominal surface which form the pattern of the surface. Includes roughness, waviness,

lay and flaws.

Tandem Duplex •Mounting: Assembly of two or more ball bearings mounted

so as to/a'ivi.tfev the thrust load.

Tarnish: A stain on the surface.

Temper: To soften hardened steel by reheating at a temperature bebow

the hardening temperature.

Thrust Bearing: A ball or roller bearing with space between rings oriented perpendicular to the axis of rotation. It is primarily intended to

carry thrust loads.

Used Bearing: A bearing that has seen service and has been subjected to

operating loads.

Width: The distance from one face of inne.r ring to opposite face of

outer ring.

Width, Inner Ring: Dimension across the inner ring.

Width, Outer Ring: Dimension across the outer ring.

ARTHUR S. IRWIVCO. INC.

Technology Consultants

Driftwood Center

Scmus Point, NY 14712

139
From. gV// 10*1*-

To: /&/ JZ*><'« Date: */'*

\»sT J'T f""' I*TM

* f»r w «<**$* *r

r>'*^, t***-^

J c*rre»<f/« t*sA.

I i *

-ft* /»+tT

ScJi is «oo) t>l £

PRATT& WHITNEY AIRCRAFT GROUP

Government Products Division

PWA 11138

140
ROLLWAy

Roll way Bearing Division 315-457-6211

P.O. Box 4BS7 Telex: 93-7265

Syracuse. New York 13221

March 16, 1983

Arthur s. Irwin Co., Inc.

Driftwood

Bemus Point, N.Y. 14712

Dear Art,

After many interruptions am finally commenting on the specification

for ball and cylindrical roller bearings reviewed at the Industry

Coordination Meeting January 24-25 1983.

Although Martin Joseph and you kept telling us that the word

"critical" meant "supply critical" not "application critical", we

.just couldn't seem to be able to keep this in focus. Our reasoning

is that today supply critical means any bearing component fabricated

from CEVM 8620 material and tomorrow may mean something else, depending on work stoppages, shortages of critical alloying elements, or

whatever.

There seems to be no challenge from the propulsion and power train

representatiges, or from the bearing manufacturer reprssentatives,

that a specification is required for high performance bearings that

protects the original contractor and TSARCOM against the procurement

by governmental agencies of substitute bearings from an unsubstantiated

source during periods of bearings being critical in supply.

There also seemed to be a concensus that not all bearings in propulsion and power train systems were required to be classified as high

performance and that the original contractor should so denote which

bearing positions are to be classified as high performance. With

this in mind, it would require that the specification be expanded to

cover more materials than VIM-VAR M50.

Regarding inspection, we feel that 100% inspection of all drawings

listed and other noted characteristics is too broad a brush and should

be negotiated with the original contractor or TSARCOM before placement and acceptance of an order.

141

DIVISION OF LIPE-ROLLWAY CORPORATION
ROLLWAy

-2-

Regards

T. L. Morrissey

Manager

Quality & Engineering

TLM/rvg

U2
UNITED • North Main Street

TECHNOLOGIES Stratford, Connecticut 06601

SIKORSKY (203)386-4000

AIRCRAFT

February 23, 1983 SEL-7715

Arthur S. Irwin Company, Inc.

Dri ftwood

Bemus Point, New York 14712

Attention: Mr. Arthur S. Irwin, President

Enclosure (1) Comments on Specifications for Ball and

Cylindrica l Rolle r Bearings

Enclosure (2) Comments on Specification - Optimized

Bearing Utilizatio n

Subject: ASICO Meeting on Bearing Specifications

At the subject meeting in Cleveland , Ohio on January 24

and 25, it was requested that comments and opinions stated

during the meeting be summarized.

Accordingly , Enclosures (1) and (2) are submitted for your

review. In addition , the followin g highlight s are my mai n

areas of concern.

1. The specification requires the use of materials (particularl y M-50) and design detail usuall y associated with

t he desig n of hig h speed engine bearings.

In many cases, bearings designed for helicopter transmission s do not need these desig n features and alternate ring materials , such as case-hardened steels, are

required to achiev e satisfactory performance.

2. Traditionally, all the design features contained on

source control drawings require source or destination

inspection by Quality Assurance. The additio n of data

required for detailed engineering analysis of bearing

performance characteristics wil l require modificatio n

of the source control format to allo w the inclusio n of

this data for Engineerin g use only.

3. The refurbishment or restoration of us'ed aircraft bearings

must be carefully controlled and the performance of these

bearings in service must be closely monitered.

143
Page 2

It is essential that any bearing that is reworked in this

manner be reidentiffed so that the rework that was accomplishe d is completely traceable. Also, the identification

of the facility performing the rework must be permanently

marked on the bearing so that any impact on component

warrantees or product integrity may be properly assessed.

I am hopeful that these problems can be resolved and am

looking forward to our next meeting scheduled for May.

Sincerely yours,

UNITED TECHNOLOGIES

Carl H. Keller, Jr.

Supervisor-Tribology

Transmission Systems

Design and Development

CHKrl d

P.S. In response to your recent letter dated 2/10/83, the following

carburizing steel grades and specifications are used in helicopter drive systems:

Specification

AMS6265

AMS6276

Timken

144
ENCLOSURE (1) COMMENTS ON SPECIFICATIONS FOR BALL AND

CYLINDRICA L ROLLER BEARINGS.

Paragrap a h

— 1 . The type of bearings should be defined, i.e., ball ,

cylindrica l roller bearings included ; tapered roller

bearings not included. The useage for the bearings

should also be defined, i.e., main shaft, mai n and

tail drive bearings are included ; accessory bearings,

free wheel unit bearings and drive shaft bearings are

not included. The work "critical" should be replaced

because the meaning of the word is very controversial

with reference to aircraft bearings.

2. Other thru-hardened steels (52100), case hardened steels

(9310,8620 CBS 600) and steel for cages (AMS 6415) should

be added.

3. The term "statistically significant" use in 3.1 and 3.2

is not definitive . Requalificatio n per 3.2 should be a

quality/engineering audit, not hardware testing.

6. Sub-contractor (usually bearing vendor) should determine

if parts can be salvaged or repaired. Contractor should

determine if variation s or deviation s are acceptable.

7. Need to differentiate between significan t and insignifi -

cant changes. Should include change in facility as

significan t change.

8. Process specifications and inspection procedures should

be approved by Contractor. Deviations must be approved

by Contractor engineerin g and quality.

9. Items 9.1.8, 9.1.9, 9.1.10, 9.1.11 and 9.1.47 should not be

on the drawing as these calculate d capacitie s and instal-

^ latio n data are not inspectable and are irrelevant with

regard to the manufacture of the bearing. Item 9.1.46

shoul d not be include d as the packagin g is dependent on

e nd useage and cannot be predicted durin g design . Completely detailin g all bearing components on a source control

drawing is contrary to the intent of thi s type of drawi ng whic h is to control the bearing desig n by limitin g

procurement to the approved sources and by demonstrating

performance wit h suitable qualificatio n tests. If the

intention of providin g complete detail s for each bearing

component is for engineerin g reference rather than inspection, then a new procedure must be implemented to allo w

engineerin g data to be referenced on these drawings.

10. Inspection methods and processes must be approved and certified by the prime contractor. In 10.2, MRB activity

shal l be approved by prime contractor. Paragraph s 10.2.2

and 10.2.3 should be deleted.

11. As stated in 2., other bearings steels should be included .

145
ENCLOSURE (2) COMMENTS ON SPECIFICATION - OPTIMIZED BEARIN G

UTILIZATION

Paragraph Title -- Suggest title be changed to Specification for Refurbishment and Restoration of Aircraft Engine and Power

Transmission Bearings.

Scope -- Should includ e type of bearings and where

these bearings are typically used.

Cleanin g -- Other methods besides ultrasonic cleanin g should

be permitted. In fact, ultra-sonic cleaning wil l not

adequately clean many assembled bearings which have

been inducted for overhaul. Also need warning that

components from different vendors should not be mixed

Preliminary Inspection -- Does not includ e provisions for nonseparable bearings. Temper colors frequently occur

due to oil staining.

N OT Evaluatio n -- Appropriate specifications and accept/reject

criteria should be give n for each NOT method.

Visua l Examinatio n of Rin g Mounted Surfaces -- Dimensiona l

verificatio n should only be required if any wear or

build-u p i s visuall y detectable.

Determination of Need for Retainer NOT Examinatio n and Replating-- Retainers with bent tangs shoul d not be salvage d

if rebending of the tangs is required.

Standard Race Grindin g Stock Removals -- Raceway honin g should

also be i ncluded .

Assembly -- Parts should be properly preserve'd. Preservation

requirements not usuall y depicted on bearing source

control drawing.

Marking , Codin g and Segregation for Packagin g -- Permanent

markin g is required to indicat e that a bearing was

refurbished or restored and where the rework was done.

146
SKF TECHNOLOGY SERVICES

SKF INDUSTRIES, INC.

February 23, 1983

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, NY 14712

Attention: Mr. Arthur S. Irwin

President

Subject: SKF Comments Regarding Proposed Specifications for

NASA Contract NAS3-23520

Reference: Industry Coordination Meeting Held January 24, and

25, 1983 in Cleveland, Ohio

Dear'Mr. Irwin:

As requested during the referenced meeting, below are the SKF

comments concerning the ball and cylindrical roller bearing specification and the specification for optimized bearing utilization. The comments detailed in this letter are the same as

those that were given by the writer during the two day conference.

Specification for Ball and Cylindrical Roller Bearings

1. Scope; It is felt that the term "critical" should be redefined as it implies a critical bearing application rather

than a need to procure bearings in an expedited manner.

2. Applicable Documents Specification; MIL-STD-10 has been

replaced by MIL-STD-100.Request AMS 6415 and AMS 6414 cage

material and AISI 52100 steel be added. ASTM-B-147-71 Alloy

864 is not an active specification. It has been replaced

with ASTM-B-584 Alloy.

3., Qualification; It is SKF's opinion that the qualification

3.1 requirements should be redefined. SKF assumes that the

qualification testing would not be performed by the bearing

supplier but rather by the O.E.M.

3.2 Requalification; It is felt that the requirement that a

statistically significant sample of bearings be requalified no less frequently than every 24 months is too restrictive. We do not see a need to requalify a bearing

on this basis if the bearings are in active production and

no design changes have been made.

P.O. BOX 515.1100 FIRST AVE.. KING OF PRUSSIA. PA 19406 I (215) 265-1900

TELEX 84-6474 | TWX 510-660-2660

147
February 23, 1983

Industry Coordination Meeting

Page 2

4. Inspection; It is SKF's opinion that the sampling plans

that would be acceptable should be spelled out in this specification. We do not believe that the sampling plan should

fall under the authority of the cognizant military individual.

The sampling plans could be detailed prior to the acceptance

of the first production order rather than after. If it is not

approved prior to a production order, it would require 100%

sampling of all characteristics which could be expensive depending upon how large the first production order is.

4.1 Inspection Details; The first article requirement should

be defined in this paragraph.

5. Procurement; No comment.

6. Rejection; The last sentence makes reference to a quality

review board. It is SKF's recommendation that it be defined

as a Quality/Material review board.

7. Change Control; The way the paragraph is defined it would

be very difficult to manufacture a bearing. The bearing

suppliers need the flexibility to make decisions to keep

the production line moving. It is our feeling that with

the paragraph stating that we must receive written approval

prior to the implementation of any change, we would not be

able to ship bearings to satisfy the critical jieeds. It is

SKF's recommendation that the paragraph state that the change

control system of each bearing supplier will satisfy this

requirement.

7.1 Change Control Approval; Comments the same as paragraph

7.

8. Process and Inspection Approval; The word "prior" should be

changed to "after".The sentence implies that a bearing supplier would have to detail all their production and process

controls and may not receive a contract. If a bearing supplier

is competitive, then the processes could be approved after the

award of the contract.

8.1 The word "specifications" should also be added to the process and inspection changes. Comments are the same as 7

above.

8.2 Process Deviation Approval: There should be an individual

specified that a supplier could contact to review and get

an opinion regarding the acceptability of a process deviation or change. A lot of time will be wasted while the

SKF TECHNOLOGY SERVICES

SKF INDUSTRIES. INC.

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February 23, 1983

Industry Coordination Meeting

Page 3

official paperwork is sent, received, and forwarded back

to the bearing supplier. This again, would not help the

supply of critical bearings.

9. Drawing Requirements: The drawing requirements should be

specified as required. If all these requirements are placed

on the drawing it will involve a great deal of inspection.

Therefore, it is suggested that the majority of these items

which are not critical to the operation of the bearing be

specified as "Engineering Data" or "Reference".

9.1.17 Retainer End Face Parallelism; Should be removed. No

need for this requirement.

9.1.24 AMS 2410 plating should be added as an option.

9.1.25 Should be removed since it is very difficult to measure

a silverplate corner build-up tolerance on a retainer.

9.1.31 The term "chatter tolerances" should be defined.

9.1.42 It is felt that a specification for each material should

be written to control the bearing material procurement.

9.1.45 Identification Requirements; A specification should be

written or the identification requirements spelled out

in this specification.

9.1.51 The inner ring high point should only be marked on critical bearings if it is required.

9.2 Cylindrical Bearing Requirements: Once again, the majority

or the requirements listed in paragraph 9.2 should be identified as "Reference" or "Engineering Data".

9.2.4 Roller Effective Length; Should be defined.

9.2.7 Roller Corner Runout; Should only be specified if

required.

9.2.10 Cage Balance; Should only be specified if required.

9.2.11 Cage Diameter for Locating During Balance; Should only

be specified if required.

The following items should be added, if required: grain

flow, roller end to flange clearance, flange angle and

configuration, 2-point and 3-point out of roundness.

SKF TECHNOLOGY SERVICES

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February 23, 1983

Industry Coordination Meeting

Page 4

9.3 Ball Bearing Requirements;

9.3.1 Contact Angle; Specified only as required.

9.3.4 Shim Thickness; Should be specified as a reference.

9.3.7 Cage Load for Measuring Contact Angle; Should only be

specified if required.

9.3.11 Ring Grain; Orientation to be substantially parallel to

groove surfaces. The word "substantially" should be defined. It is also requested that this be specified only

when required. This requirement precludes the use of

hammer forgings, bar stock or tubing for the bearings.

9.3.12 Cage Balance; Specify only when required.

9.3.15 Bearing Preload; This should be specified as required.

9.3.16 Contact Angle Verification Gauge Load; Should be removed.

9.3.18 Stand-off of Ball Groove from locating end face of ring

should be removed.

10. Inspection Processes; The words "cognizant military authority

as delegated through DCAS" should be removed and replaced with

"prime contractor".

10.1 Inspection Methods to be Certified; The term "and processes"

should be added after "inspection methods". It should be

spelled out who will do the certification.

10.1.1 Material Stabilization Verification; This statement

should be defined.

10.1.4 The term "magnaflux" should be replaced with "magnetic

particle inspection".

10.1.5 Visual Defect Examination; Should be specified as surface defect examination.

10.1.11 The term "shot beed" should be removed. The term "eddy

current inspection" should be added as an acceptable

method.

10.2 Material Review Board; Paragraphs 10.2.2 and 10.2.3 should

be removed.

SKF TECHNOLOGY SERVICES

SKF INDUSTRIES. INC.
February 23, 1983

Industry Coordination Standards

Page 5

10.3 Inspection Standards; The term "industry standards" should

be defined as this is a vague statement.

11. Material; -This specification only defines M50 type steels.

There are many mainshaft and accessory bearings that are

manufactured AISI 52100 steels as well as carburized materials.

It is SKF's recommendation that different types of materials

be added to the materials list.

11.1

11.1.1 The term "high speed" should be removed from the type of

forgings. This implies that only ring rolled forgings

can be used.

11.2 Processes; No comment.

11.3 Reference Specification; No comment.

11.3.1 Aerospace Materials Specifications; Reference to the

added materials should be made to this paragraph.

11.3.2 American Society for Testing Materials; ASTM-E604 should

be ASTM-A604.

11.4 Chemical Composition; No comment.

11.4.2 No comment.

11.4.3 The paragraph references the limits for carbon content

as -.01 under minimum in lieu of + or - 0.03 per AMS 2259.

This is a deviation from the current material composition

for M50 type steel. SKF is requesting that the requirements, as specified in AMS 2259 be retained.

11.5 Forming Condition; No comment.

11.6 Quality Tests; No comment.

11.6.1 The last sentence makes reference to the fact that the

material shall have substantially uniform macro-structure

and grain flow. The term "substantially" should be

removed from the paragraph.

11.6.2 No comment.

11.6.3 Magnetic Particle Stepdown Test; This requirement should

be specified only where required. It is not standard pracSKF TECHNOLOGY SERVICES

SKF INDUSTRIES, INC. 1 51
February 23, 1983

Industry Coordination Meeting

Page 6

tice to perform a magnetic particle stepdown test if the

material is ultrasonically tested.

11.6.3.1 This paragraph states that specimens shall be taken

from 4 inch square billets representing the top and

bottom of each ingot. We would prefer that the paragraph state to check the top and bottom of the first,

middle and last ingots.

11.6.4 Macroetch; No comment.

11.6.4.1.2 The conditions for freckles, white spots, radial

segregation and ring pattern are specified as having

a severity reading of "A" for all four items. The

ratings for the severity should be changed to A, A,

B and C respectively. This is in line with current

material inspection requirements.

11.6.4.2 Finished product Inspection; No comment.

11.6.5 Grain Size; No comment.

11.6.6 Inclusion contest should be "inclusion content". Ratings are specified for inclusion content of both thin

and heavy types. The requirements for heavy type B, C,

and D which are specified as zeros should «be changed to

1.0. The requirements of zero are tighter than current

material standards for M50 steel.

11.6.6.1 If inclusion ratings of 1.0 are added in 11.6.6 a statement will have to be added defining the number and quantity of the rateable fields for heavy types.

11.6.7 Ulatrasonic Inspectiont No comment.

11.6.7.2 The term "shear" should be defined. In addition, the

longitudinal requirement of 20% of the 1/64" flat

bottom hole-depth: half of section dimension, appears

to be tighter than current standards. It is suggested

that the material suppliers be contacted to see if

they can consistently meet this requirement.

11.7 Decarburization of Surface Defects; No comment.

11.8 Tolerances; No comment.

11.9 Rejections; No comment.

11.10 Jnspection:

SKF TECHNOLOGY SERVICES

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February 23, 1983

Industry Coordination Meeting

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11.10.2 The term "original" should be added before "purchaser".

11.11 Material Certification; No comment.

Optimized Bearing Utilization Specification

Scope; No comment.

Cleaning; This paragraph specifically states that ultrasonic

cleaning must be used. It is suggested that other cleaning

methods be shown as acceptable options.

Preliminary Inspection; Reference is made to bearings which

are separable. With separable designs it is easy to review the

rolling contact surface. A statement should be added regarding

bearings that are non-separable. Those bearings which are nonseparable will more than likely have to be dismantled by cutting

the cage from the bearing. It is felt in these type bearings

the cage and rolling items should automatically be replaced.

NTD Evaluation; The term "magnaflux" should be replaced with

"magnetic particle". The term "ultrasonic magnetic resonance"

should be removed. In addition, rather than specifying that

all the subject NTD's must be performed, it might be better to

specify some inspections are required.

Visual Examination of Rolling Contact Surfaces; This paragraph

specifies that a 2 to 5 power magnifying glass be used. This

should be removed and replaced with the un-aided eye. In addition, reference is made to the evidence of nital etch in this

paragraph. It is felt that this should be removed from the

examination as this is a NDT requirement.

Visual Examination of Ring Mounting Surfaces; No comment.

Dimensional Verification; Instead of specifying .002" material

thickness per side shall be removed, it would be better to

specify a maximum material removal amount. There is no need

to remove a given amount of material if it is not necessary.

In addition, replating is specified. The type and method of

plating should be specified.

Visual Examination of Retainer Wear Area; The paragraph implies that the rolling elements can be removed from the bearings. This is possible with separable assemblies, however,

bearings which are non-separable should have the retainers

SKF TECHNOLOGY SERVICES

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February 23, 1983

Industry Coordination Meeting

Page 8

replaced since some sort of cutting, bending or twisting of the

cage may be required to remove rolling elements from the nonseparable assemblies. Cages and rolling elements should automatically be replaced.

Determination of Need for Retainer NTD Examination and

Replating;The term "magnaflux" should be replaced with "magnetic particle inspection". Reference is also made to non-ferrous materials which will be subjected to florescent penetrant

examination. It should also be permissible to subject ferrous

material cages to florescent penetrant examination.

The second paragraph mentions that the parts should be replaced to the original drawing requirements. In some cases,

depending on the degree of wear over, maximum plating may be

required to bring the dimensions within original drawing requirements. If this is done, then the maximum silverplate

thickness as specified in the original drawings may be violated.

This should be clarified.

Determination of the Need For Restoration; Once again, a maximum amount of stock removal should be specified.

Standard Race Grinding Stock Removal; As noted above, the

requirement that .003" per side material thickness must be

removed from each race should be replaced by a maximum depth

of stock removal.

Reference is made that the grinding process shall be monitored

by nital etch inspection. Different methods should be added,

such as eddy current inspection. It also states that the nital

etch shall be removed by vibratory finishing. Other methods of

etch removal should be specified as options.

Reinspection for Verification of Dimensional Details: The

requirement that all characteristics be evaluated 100% to

insure compliance with the original drawing requirements

should be revised to specify particular dimensions that would

need to be evaluated 100%. The rest of the parameters could

be checked on a sample basis. In addition, a maximum diameter

should be specified for the oversize roller paths.

Procurement of Replacement Rolling Elements: No comment.

Grading and Matching of Diameters and Rolling Lengths to

Ring Sets; Specific references is made only to roller bearings.

Different types of bearings should also be added to this

paragraph.

SKF TECHNOLOGY SERVICES

SKF INDUSTRIES. INC. -, 54
February 23, 1983

Industry Coordination Meeting

Page 9

Preassembly Verification of Ass«*TMhly of Matched Parts; No

comment.

Assembly; Reference is made to specifically using ultrasonic

cleaning to clean the parts. Other methods of cleaning should

be added to this paragraph.

Post-Assembly Inspection; No comment.

Marking, Coding and Segregation for Packaging: A definite

system should be spelled out in this specification which will

detail the marking methods allowed. A suggestion would be to

use AS478. In addition a requirement should be added for material traceability during the repair process.

Sampling for Qualification Testing and D'CAS Verification; A

sampling plan should be established in this specification and

should not be left up to the appropriate military authority.

I hope that these comments will be useful to you during the review

of the proposed specifications. If you have any questions regarding these comments, please feel free to contact me.

Sincerely,

R. A. Litts

Applications Engineering

RAL/jh

cc: J. L. Blake

S. J. Paine

SKF TECHNOLOGY SERVICES

SKF INDUSTRIES. INC. . 155
TRWBEARINGS DIVISION

January 31, 1983

Arthur S. Irwin Company, Inc.

Driftwood

Bemust Point, New York 14712

Subject: Industry Coordination Meeting - January 24 and 25, 1983

NASA Contract NAS3-23520: Review and Critical Analysis

Rolling Element Bearings for System Life and Reliability.

Dear Art,

At the time of the subject meeting, responses were requested from

attendees. Following are TRW's comments regarding specific points.

Before preceding to the specifics, I would like to make two general

comments.

First - Please accept congratulations on the manner in which the meeting

was conducted. You, Bill Derner and Bill Anderson organized a tremendous amount of material for our studies and discussions. Due to the

prior organization and the manner in which the meeting was conducted,

a tremendous volume of material was reviewed.

Second - There is concern at TRW as to the "over-kill" aspects of the

specification. While TRW is in an excellent position to supply bearings

to the highest level of technology, there remains a question as to the

need for over-specified bearings in every position in every engine or

helicopter gear train. Perhaps two levels of sophistication should be

considered: one level for high speed, heavily loaded bearings and a

second level for lower speed, lightly loaded bearings. In our opinion,

the second level should allow the designer to select 52100 steel, for

example.

Paragraph 2 - Applicable documents - specifications:

•Specifications listed in Paragraph 11.3 are not included.

•Quality specifications such as MTL-I-45208, MIL-Q-9858, MIL-STD 1535, MIL-STD

1520 are not listed.

•AMS 6414 or 6415 which is used extensively for cage materials is not.

listed.

•Several comments were made at the meeting regarding the preferability

of AMS 2412 silver plating in lieu of AMS 2410.

Paragraph 3 - Qualification

•Requalification criteria should be: a significant change in design,

material or manufacturing procedure and plant location. If a part has

not been manufactured for a period of time (such as 24 months), a new

first article inspection should be performed.

BEARINGS DIVISION OF TRW INC.

4O2 CHANDLER STREET JAMESTOWN. NEW YORK 14701

TELEPHONE (7161 661-2600 TELEX 91527 BEARINGS

156
Arthur Slrwin company, Inc. SHEET NUMBER

 2

January 31, 1983

•The engine manufacturers and the helicopter manufacturers indicated

that qualification or requalification should be a responsibility of

the original prime contractor.

Paragraph 4 - Inspection

.Quality sampling plans must be negotiated before placement of a production order.

The role of DCAS was discussed. It was pointed out that DCAS does not

verify measurements, but monitor quality systems.

•Once process capability is demonstrated, a sampling plan should be permitted.

Paragraph 6 - Rejection

•Rework of parts is an on-going function as part of the regular manufacturing process. Only major repair procedures should be subject to

approval. The approval authority should be the prime contractor rather

than the cognizant military authority.

Paragraph 7 - Change Control

•The change control as listed is more restrictive than any current requirement from bearing customers. Restrictive change control system

will ensure the perpetuation of obsolete manufacturing practices and

result in a substantial increase in bearing prices and decreased

availability. TRW feels strongly that print and specification requirements should deal with measurable requirements to be incorporated in

the bearing, and not focused on nit-picking details as to how the part

is manufactured. The imposition of a restrictive change control system

could have a result which is entirely counterproductive to the aim of

the specification which is to enhance the availability of reliable

bearings.

Paragraph 9 - Drawing Requirements

•It seemed to be the consensus of the meeting that engineering data

which would be useful in analyzing bearing performance should be

supplied by the prime contractor on a separate sheet, rather than to

over-complicate the drawing by having details extraneous to the actual

material, inspection and manufacturing requirements.

•NOT.requirements should be listed on the print as well as the allowability of the use of associated sampling plans.

•Paragraph 9.1.27 should read "other critical retainer details as

required".

•Packaging requirements as listed in Paragraph 9.1.46 should not be

listed on the drawing.

•Under 9.2 cylindrical bearing requirements, in certain cases it is

important, that the bearing drawing list additional details such as

the roller end clearance, sidewall configuration, roller drop in the

cage, and bilobe/trilobe features.

•Under 9.3 ball bearing requirements, it is important that the interrelationship between contact angle, IRC and end play be recognized.

Specification of all of these requirements has the impact of drastically increasing prices and loss of availability.

MRC

BEARINGS

157
Arthur S. Irwin Company, Inc. 3

January 31, 1983 SHEET NUMBER

•Paragraph 9.3.11 should be modified to indicate that specific

grain orientation should be specified only as required. This also

has a substantial increase on costs in many cases.

Paragraph 10 - Inspection Processes

•The prime contractor should have responsibility for reviewing inspection

methods and processes, and not DCAS.

•Paragraph 10.1.2 should be worded in such a way as to suggest the

allowability of decarburization on non-critical surfaces. Failure to

do so will negate many cost reduction programs which are underway to

permit the usage of "black" surfaces.

•Usage of eddy current on rolling elements and raceways is accelerating.

•All prime contractors have established methods for dealing with deviated

material. Material review board procedures are ordinarily followed for

self-authorization of deviant parts. The controls established by the

prime contractors have proved to be effective throughput the years.

The following comments are applicable to the proposed specification for

optimized bearing utilization (repair/rework/refurbishment) :

.The controls established under the new bearing specification outline a

carefully controlled approval procedure for original equipment bearings.

It is inconsistent that the rework specification does not have similar

controls established. TRW is concerned about the product liability

aspects of unauthorized sources performing rework on our product.

•TRW has extensive experience in refurbishing mainshaft jet engine bearings

We do not ultrasonic clean parts on receipt, but use an abrasive slurry

method for preparing the parts for further examination and rework.

Lengthly discussions were held regarding rework of non-separable bearings

•Several of the prime contractors pointed out the dangers associated with

rebending tangs. There are similar concerns associated with disassembly

of the cage in a conrad type bearing and subsequent reuse of the parts.

•NDT evaluation of components should follow the same requirements as

exist on the original equipment product.

•Visual examination of rolling contact surfaces. TRW uses the unaided

eye. Questionable indications are clarified through the use of magnification. Any parts subject to retempering should be thrown out.

•TRW has had excellent results in replacing all of the original rotating

components: inner rings, rollers, balls and cages in our refurbishment

program.

•Replating of cages in excess of the amount specified on the prime

contrator's print should not be permitted. TRW discards cages -showing

base wear of the metal.

•FPI should be used as an NDT option to MPI for steel cages.

• TRW questions the economic friability of regrinding in general. The

logistics associated with maintaining a supply of components with extra

stock as well as special cages to accommodate oversized rolling elements

makes this entire procedure questionable. It is very important for

critical bearings that the cage pocket clearance not be altered from the

original design intent.

•Original equipment requirements do not encompass ultrasonic cleaning for

new bearings. The imposition of this procedure for restored bearings

is questionable.

•It is believed that the specification should set up a special marking

procedure to clearly indicate that the bearing has been reworked, and

the source of such reworking.

Daniel Lundquist

DL/ds Manager Aircraft Engineering

158
NAS3-2352Q

NAME

APPENDIX C

ATTENDANCE LIST

SECOND INDUSTRY COORDINATION MEETING

COMPANY

June 1-2, 1983

1. Anderson, William

2. Artuso, John

3. Battles, Roy

4. Blroscak, Ron

5. Branhof, Edward

6. Campbell, Arthur

7. ColUnge, Kenneth

8. Derner, William

9. Dutta, MHten

10. George, Richard

11. Gilbert, Robert

12. Ironside, William

13. Irwln, Arthur

14. Joseph, Martin

15. Keller, Carl

16. Lagasse, Normand

17. Llnhares, James

18. Lundqulst, Daniel

19. Malott, R. Clayton

20. Morrlssey, T. L.

21. P1neo, Carroll

22. Poole, William

ASICO

A1r Force

Bell Helicopter

FAG

AVRADCOM

Fafnlr

AVCO Lycomlng

ASICO

AVRADCOM

Kaydon

Garrett Turbine Engine

Pratt and Whitney

ASICO

TSARCOM

Sikorsky

AVCO Lycomlng

AVRADCOM

TRW

Detroit Diesel

Rollway

General Electric

Pratt and Whitney

159
NAME . COMPANY

23. Ross, W. J. Split Ballbearing

24. Scheldt, R. N. Detroit Diesel

25. Schuetz, Harold AVRADCOM

26. Signer, Hans Industrial Tectonics

27. Weden, G11 AVRADCOM

28. Zaretsky, 1. V. NASA

160
APPENDIX D

WRITTEN COMMENTS ON SECOND INDUSTRY COORDINATION MEETING

1. Boeing Vertol Co. letter Sept. 20, 1983 (J. W. Lenskl)

Encl.: Pg. 1 - RRR Spec.

Pgs. 3,4 - Procurement Spec.

2. Detroit Diesel Allison letter June 29, 1983 (R. N. Scheldt)

3. FAG Bearings Corp. letter June 28, 1983 (R. M. Blroscak)

4. General Electric letter Sept. 6, 1983 (C. B. P1neo)

5. Industrial Tectonics, Inc. letter June 24, 1983 (H. R. Signer)

End.: Pgs. 5 thru 13 - RRR Spec., Glossary

6. Kaydon Corp. letter June 3, 1983 (R. F. George)

End.: Pgs. 5 thru 13 - RRR Spec., Glossary

7. Pratt and Whitney Aircraft Group note June 4, 1983 (W. E. Poole)

End.: Pgs. 5 thru 13 - RRR Spec., Glossary

letter Sept. 21, 1983 (W. R. Ironside)

8. Rollway letter Sept. 7, 1983 (T. L. Morrlssey)

9. Split Ballbearing letter Nov. 3, 1983 (W. J. Ross)

10. TRW Bearings D1v. letter June 6, 1983 and Sept. 15, 1983 (0. Lundqulst)

161
BOEING VERTOL COMPANY

P.O.Box 16858

Philadelphia. Pennsylvania 19142

7484-JWL-127

September 20, 1983

Arthur S. Irwin Co. Inc.

Driftwood Center

Bemus Point, NY 14712

Subject: Specification for Ball and Cylindrical Roller Bearings and Rework,

Refurbishment and Restoration of Aircraft Engine and Power Transmission Bearings

Dear Art:

The two documents submitted by your letter of August 24, 1983 have been reviewed

and several comments are provided in this letter. Boeing Vertol generally agrees

with the wording of these documents except for two areas. These areas have been

added since the last reading. Our comments concerning these areas are as follows.

1. In both documents, Section 3. - Qualification/Certification

Reference Enclosures 1 and 2

Boeing Vertol does not feel that qualification of a bearing can be accomplished

by similarity with another part. Each part should be qualified under a given

set of load conditions by actual testing of the part. Therefore, this paragraph

should be removed from both documents.

2. In the Specification Document, Section 6. - Change Control

Reference Enclosure 3

The word significant should be removed and also the last sentence should be

deleted. Boeing Vertol does not allow any change in the control plan without

prior approval. Many non significant changes have resulted in problems.

Therefore, the interpretation of significant should not be made by a person

unfamiliar with the part and its application.

162
Arthurs S. Irwin Co. Inc.

September 20, 1983

Page 2

Other than the few comments made above, the two documents as presented would

be acceptable to Boeing Vertol. Most of the requirements of these documents

are currently in effect in one form or another. These documents will make it

more uniform for all suppliers of aircraft engines or power transmissions.

I hope that these comments will be helpful in finalizing your specifications.

If you have any questions concerning these comments, please call me on

(215) 522-3902.

Sincerely,

BOEING VERT0ZT COMPANY

I. Lenski Jr.

"Seniof Engineer

/mj

Enclosures

163
Enclosure (1)

August 5, 1983

SPECIFICATION

Rework. Refurbishment and Restoration of Aircraft Engine and Power Transit salon Cy"H"di»<^M^ Ro^j.er and Ball Bearings

1. Scope - This specification shall prorlde for the optimised utilisation

of aircraft engine, Bain power line transmission and auxiliary bearings

determined to be critical either by virtue of their performance, function

or availability.

1.1. Sources - Those bearings to be processed under the provisions

of this specification may be used bearings removed after service, unused

bearings returned from the field, or rejected bearings returned fpr reinspection and salvage.

2. Applicable Doctnents - See Bearing Procurement Specification f

for general specifications, standards and other supporting documentation.

In addition the following will apply s

MIL B 58105 Bearing Restoring by Bacevay Grinding

KAVAIR 01-11-503 (TM 55-1500-322-24) US lavy Bearing Manual

HAVAIB 02-1-517 US Havy Standard Maintenance Procedures for Pratt fc

Whitney Aircraft Bigines

3. Qualification/Certification - Sources for bearing refurbishment and

restoration must be qualified by the original contractor or the cognizant

government agency by dynamic testing or quality audit.

Refurbished or restored bearings shall be permanently marked to Indicate

name of procurement agency, as well as all other markings required to

ensure traceability.

3.1. Requallficatlon Requirements - On those bearings for which a

new facility is to be utilised, or for which a significant process or

design change is intended, requallfication is required. The cognisant

government authority may conduct the qualification by testing or quality

audit, or may delegate this responsibility.

3.2. Recertiflcation Requirements - For those bearings which have

not been processed for four years or more, recertiflcation of processes

and standards by the original/prime contractor is required. As an alternative the cognisant government authority may perform the reeertlfication.

ARTHUR S. IRWIN CO. INC

Technology Comuituu continued next page

Driftwood Couer

Bemu* Petal, NY 14712

164
ORIGINAL PAGE jg

OF POOR QUALTfY Page -3-

AHSI I 14.5

MIL-STD-045662

MIL-STD-U3

MIL-STD-1520

MTL-BTD-1535

HIL-STD-880

KIL-I-45208

MIL-I-6868

MIL-H-6875

DOD-STD-100

2.2.2.

listed in 2.

MIL-STD-129

.2.1.

Dimensioning and Tolerancing for Engineering

Drawings

Traceability to HBS Standards

Standards and Specifications, Order of Precedence

for the Selection of

Corrective Action and Disposition System for

Nonconforming Material

Supplier Quality Assurance Program Requirements

nondestructive Testing Requirements for Metals

Engineering Craving Practices

Inspection System Requirements

Inspection Process, Magnetic Particle

Heat Treatment of Steels (Aircraft Practice) Process for

Engineering Drawing Practices

Supportive Standards referenced in those standards

Marking for Shipment and Storage

3. Qualification/Certification - Sources for hearing procurement must

be qualified by the original contractor, by dynamic testing or quality

audit.

Bearings Procured by other than the prime contractor shall be permanently marked to Indicate name of procurement activity, as veil as other

markings required to ensure traceabillty.

3.1. Requalification Requirements - On those bearings for which

a new facility is to be utilized, or for which a significant process

or design change is intended, requalification is required. The cognisant authority may conduct the qualification by testing or quality

audit, or may delegate this responsibility.

3.2. Recertiflcation Requirements - On those bearings which have

been out of production for four years or more, recertiflcation of

processes and standards by the original/prime contractor is required.

As an alternative, the cognisant government authority may perform the

recertification.

4. Inspection - Inspection of assemblies and components shall be

conducted in accordance with negotiated quality plans which shall

include record requirements.

ARTHUR S. IRWIN CO. INC

Tcctwology ConwItMU

Driftwood Ctatcr

Bcrous Petal, NY 14712

continued next page

165
Enclosure (3)

Page -4-

4.1. Inspection Details - first article Inspection details shall

be recorded and Maintained as a permanent record. Subsequent inspection

requirements shall be per the quality plan.

5. Rejection - All components and assemblies which are rejected may be

identified and held for Quality/Material Review Board action. Those

components which may be reworked shall be rerouted at the discretion

of the manufacturer, providing the original drawing requirements are

met. Assemblies may be disassembled and reassembled providing this is

accomplished in accordance with the negotiated Quality Control Plan.

6 . Change Control - There may be no &&&&&& change to the original

design, material, tolerances, basic process, quality control plan, heat

treat, post heat treat or rework procedures without prior approval of

the original contractor or the cognizant government authority.

/^

6.1. Change Control Approval - Any request for change shall be

the responsibility of the vendor to submit, and obtain approval prior

to the initiation of work on the contract.

7. Process and Inspection Approval - All process operations and inspection procedures will be evaluated and confirmed by the original

equipment manufacturer or the cognizant government authority or his

delegated representative, to ensure compliance with currently accepted

aerospace industry standards. This will include all destructive and

non-destructive methods and Quality Control Plans and Inspection methods.

7.1. Process and Inspection Changes - These shall be requested and

approval pursued as stated in paragraph 6, with the exception that processing may continue, verbal approval having been granted. It shall be

the responsibility of the vendor to provide documentation in each such

instance.

8. Drawing Requirements - Drawings shall be in accordance with DOD-STD100 and KEL-STD-880 and shall contain the Information listed in the

following paragraphs. Where existing drawings are ioooaplete, they

may be supplemented to include the following da tat bearing usage(a),

qualified sources, change numbers, bearing installation and operating

data necessary for analysis of the bearing as applied, etc. Separate

sections may be utilized to define design and include process data

and details to be covered by Quality Control requirements.

8.1. General Bearing Requirements, where specified

ARTHUR S. IRWIN CO. INC

Technology CoMuiunu continued next page

Driftwood Ccater

Bemus Point. NY 14712

166
Detroit Diesel Allison

Division of General Motors Corporation

June 29, 1983

Indianapolis Operations

P.O. Box 894

Indianapolis, Indiana 46206-0894

Phone: (317)242-5000

Cable: GM COMM IND A

File No. A0491

Arthur S. Irwin Co., Inc.

Driftwood Center

Bemus Point, NY 14712

Dear Mr. Irvin:

During the meetings of June 1 and 2, 1983 at Cleveland with representatives of

your company, NASA - Lewis Research Center, U. S. Army and U. S. Air Force,

aircraft engine and air frame builders and rolling bearing manufacturers

revisions of two proposed military specifications were discussed in

considerable detail. These revisions were based on your consideration of

those comments, both verbal and written, resulting from our previous review

during similar meetings of January 24 and 25, 1983. The first specification

covers the requirements for the qualification and procurement of gas turbine

engine mainshafts and propulsion power train rolling element bearings. At the

discretion of the cognizant military authority, this specification may also be

applied to those bearings in critical supply. The second specification is

described as the requirements for the rework, refurbishment and restoration of

aircraft engine and power transmission cylindrical roller and ball bearings.

This latter specification includes the means of determining if such action is

required and if required how this is to be done.

It is in response to your request for written comments form the attendees that

the following comments are made. Where appropriate these comments are

referenced to the proposed specification copies distributed prior to the above

meeting in terms of page number, section number or heading, paragraph number

and line number. Where comments outside of the discussion and consensus at

the above meeting are necessary such rationale is also included.

Specification for Ball and Cylindrical Roller Bearings. This specification

dated April 29, 1983 now includes materials other than the M50 tool steel

initially discussed. For the M50 tool steel the inherent hardness

characteristic is very desireable but its inherent brittleness at times

leading to its very rapid crack propagation and ultimate failure has been

considered by some as very undesireable.

167
File No. A0491

June 29, 1983

Page 2

Page 2, Section 2.1. Specifications AMS6265 and AMS6276 should be considered

for inclusion.

Page 4, Section 8.1.16. The portion of the first sentence in the note

beginning with "retainer" and ending with "tangs" should be omitted.

Page 4, Section 8.1.17. The word "mounted" should be replaced with the word

"unmounted".

Page 5, Section 8.1.22. Insert the word "pockets" before the word "and".

Page 5, Section 8.1.23. Change to "Lobing, waviness and chatter tolerances

applicable to bore and outer diameters".

Page 5, Section 8.1.24. Replace the word "required" with the word

"requirements".

Page 5, Section 8.1.28. Consider replacing "VCEM" with "CEVM" in three

places. Consider adding "VIM-VAR 52100" and "VIM-YAR 9310".

Page 5. Section 8.1.30.1. Discussion indicated that the contention that

rolling elements having a hardness one to two points Rockwell"C" harder than

the rings provide improved fatigue life is controversial.

Page 5, Section 8.1.31 Some concern was expressed as to whether AMS7276

should be replaced with AMS6276 as the proper specification.

Page 5, Section 8.1.32, Line 4. Replace "traceablility" with "traceability".

Page 5, Section 8.1.34. Delete "for all evidence".

Page 6, Section 8.2.2. Add "and diameter".

Page 6, Section 8.2.12. Insert "and length" after the word "Diameter".

Page 6, Section 8.3. Add after "Ball Bearing Requirements", "In addition to

the general requirements listed in paragraph 8.1, the following are required

for ball bearings:".

Page 6, Sections 8.4.1, 8.4.2, 8.4.3, and 8.4.4. The consensus of the

discussion indicated omitting these load ratings. I believe that some

standard for load ratings should be specified.

Page 7, Section 8.4.6. Omit. This is already covered in section 8.1.5.

168
File No. A0491

June 29, 1983

Page 3

Page 7, Section 8.4.8. Omit.

Page 7, Sections 8.4.9, 8.4.10 and 8.4.11. Omit. This is already covered in

Section 8.3.

Page 7, Section 9.1.5. There was some question how a visual inspection could

be certifiable as a meaningful record.

Page 7, Section 9.2.1. Specification MIL-STD-45616 may be included as a

reference standard.

Page 9, Section 10.4.2, Line 2. Replace "4.1" with "10.4.1".

Page 11, Section 10.6.6.1, Line 6. Consider replacing "thick" with "heavy".

Page 12, Section 10.10.3, Line 1. Correct "mehtods" to "methods".

Page 13, Item 10, Line 2. Correct "cord" to "cold".

Specification for Rework, Refurbishment and Restoration of Aircraft Engine and

Power Transmission Cylindrical Roller and Ball Bearings.The initial four

page draft of this specification has been expanded to thirteen pages dated

May 18, 1983. The following comments apply to the later draft.

Page 1, Title. Insert the word "Roller" after the word "Cylindrical".

Page 1, Section 2. Include the respective titles to the three specification

to the three specified documents.

Page 1, Section 3. The threshold of acceptance for this dynamic test for

qualification should be specified. It is suggested that confidence

statements, performance ratios and relative criticality be a part of such a

definition.

Page 2, Section 6, Line 4. Insert the word "rework" before the word

"manufacturer".

Page 2, Section 6, Line 6. Should read in part "in accordance with a

negotiated quality control plan.".

Page 3, Section 10.1, Item e. Inactive and active surfaces are to be defined.

Page 3, Section 10.1, Item g. Dynamic testing to be further defined relative

to noise level, torque characteristics and/or similar dynamic parameters.

Page 3, Section 10.2, Item c. Add "or provide new components".

169
File No. A0491

June 29, 1983

Page 4

Page 3, Section 10.5. Original identification should also be maintained.

Traceability of all components should be provided.

Page 4. Cleaning methods should allow adequate alternate methods in four

places on this flow chart.

Page 5. See later comments relating to regrinding.

Page 6, Bore Diameter. Replace the word "Inside" with "Inner".

Page 6, Boundary Dimensions. Replace "corner.(s)." with "corner(s)".

Page 6, Burnish. Burnish is more commonly used as a verb or processing method

rather than a condition.

Page 7, Dimensional Stability. Could be more directly defined in terms of

metallurgical transformations and corresponding volumetric increases or

decreases.

Page 7, Dynamic Balance. Consider changing to "That condition for a rotating

body where the axis of rotation is a true principal central axis of the body.".

Page 7, Eccentricity. This parameter is a linear distance. Consider "The

linear distance between the center of a generated circular (cylindrical)

surface with respect to the center of another generated circular (cylindrical)

surface of the same body.".

Page 8, Inclusion. Consider omitting the word "molecular".

Page 8, Inspection, 100%. Replace "Specified" with "specified".

Page 8, Lands. Replace "flat" with "cylindrical".

Page 8, Land Riding Retainer, Line 2. Add the word "land" after the word

"ring".

Page 9, Nominal. Consider "Characteristic or typical value".

Pae 9, Particulate. Delete"Existing in the form of".

Page 10, Profile (measured). Replace the word "obtaimed" with "obtained".

Page 11, Rating Life (L10), Line 2. Replace "atain or exceed" with "attain".

Page 11, Roller. Consider "Cylindrical rolling element.".

no
File No. A0491

June 29, 1983

Page 5

Page 12, Skew. Correct "nonsymetrical" to "nonsymmetrical" or "asymmetrical".

Page 12, Smearing or Pickup, Line 1.. Correct "die" to "due".

The title of this proposed specification is not fully descriptive in that

bearing rework as described in section 10 is divided into three categories,

namely processing, refurbishment and restoration. Processing bearings

involves the lowest level of effort and includes demagnetization, cleaning,

non-destructive testing, visual inspection, minor repair (buffing and

polishing), dimensional inspection, dynamic testing, lubrication and

packaging. Refurbishment of bearings includes the above processing of

bearings and one or more of replacing rolling elements, reworking or replacing

retainers, interchanging components, buffing or housing of mounting surfaces

and housing of raceways (less than 0.00015 inch total metal removal per

surface). Restoration of bearings includes processing of bearings and

refurbishment of bearings as well as one or more of raceway grinding (up to

0.002 inch per surface), installing oversize rolling elements and installing a

replacement retainer when required.

The above possibilities result in the following areas of serious concern.

1. Traceability. A set of records properly maintained would be required

for each individual bearing to determine which agency, original

manufacturer and all subsequent reworking groups have contributed and in

what way to the current condition of this particular bearing. Mixed

lots of manufactured components are also likely to be involved.

2. Product Liability. In addition to the original manufacturer, the

various aircraft engine and power transmission builders and end users

another group of remanufacturers contribute to the well being or

degrading of individual bearings and their performance capabilities.

This tends to force innocent parties to be liable should litigation

occur.

3. Readiness. New replacement components for bearings are likely to be

made by currently established bearing manufacturers. On this basis

manufacturing replacement components may be considered as small lots of

various specialty items and thus are not considered commercially

attractive until accumulative quantities are sufficiently large which in

turn results in protracted delays in delivery. A possible alternative

is to have smaller, less experienced personnel and limited or inadequate

facilities be used to shorten promised delivery times. This latter

alternative may be expected to provide an inferior product. This

dilemma would especially apply to non-standard rolling elements and

cages.

171
File No. A0491

June 29, 1983

Page 6

4. Degradation of Reliability. The effect of regrinding raceways on

reworked bearing fatigue life was discussed June 1 and 2. The

conclusions reached from these comments are certainly not clear. Some

have said that reworked bearings used in commercial aircraft perform as

well or better than new bearings. Similar activities in Israel for

aircraft usage was described by Mr. E. V. Zaretsky of National

Aeronautics and Space Administration (NASA). Current inspection and a

fatigue life testing program at Southwest Research Institute was

described by Mr. M. Joseph of the U. S. Army Troop Support and Aviation

Material Readiness Command (TSARCOM). However hard data for the above

situations was not presented.

In the 1950's a prominent ball bearing manufacturer ran controlled laboratory

tests to evaluate the endurance qualities of used bearing rings which had been

ground to remove all surface evidence of fatigue failure. Test results

indicated the following:

1. Fatigue failure is likely to recur in a short period of time at the same

location of previous distress. The heavier the load, the more likely is

the recurrence and the worse the life comparison.

2. Surface fatigue failure is more likely to occur in reground bearings

than in new bearings even when no surface fatigue had occurred in the

original bearings prior to regrinding.

During intended usage rolling bearing raceway and rolling element materials

undergo subsurface metallurgical changes. Mr. T. A. Harris^ describes this

with photomicrographs as stress cycled structure having white deformation

bands and lenticular carbide formations and showing orientation of carbides to

direction of rolling. This almost certainly indicates that that material

undergoing such changes has given up some of its initial fatigue resistance.

Therefore in order to provide a reworked bearing with fatigue resistance

equivalent to that for a new bearing nearly all of the stress cycled material

should be removed. Further if the bearing raceways had been heat treated in a

manner to provide a beneficial residual stress field regrinding the raceways

would further degrade the bearing fatigue resistance through altering the

residual stress field.

T. A. Harris, "Rolling Bearing Analysis", John Wiley and Sons, Inc.,

New York, N.Y., 1966, pages 134-136.

172
FAG BEARINGS CORPORATION

•,_100 years oi industrial ball production I~

11883

"1983

1 1 a HAMILTON AVE. P.O. BOX B1 1

STAMFORD. COMNECTICUT OSSO^

PHONE: I3O3) 337-1 SBO/TELEX 96-593-3

TWX 71 O-47d-OB91 /CABLE FAG USA

June 28,1983

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, New York 14712

Attention: Mr. Arthur S. Irwin, President

REF: FAG Comments Regarding June 1,

Coordination Meeting

2, 1983 Industry

Dear Mr. Irwin,

SPECIFICATION FOR BALL AND CYLINDRICAL ROLLER BEARINGS

Of greatest concern towards implementation of this specification is the need

for "qualification" of any bearing made by a manufacturer that has not previously

made the particular design. FAG feels that the prime contractor must coordinate

between the bearing manufacturer and the particular government agency to assure

all parties of ending up with a safe, trouble free bearing.

On the subject of rolling element vs ring hardness, it depends on the

individual case but in general FAG doesn't believe that the rolling element

hardness should be harder than the rings. Once again this should be up to the

engine, airframe manufacturer and bearing company to decide.

As discussed, specifics regarding materials should be left out of this

particular specification.

As far as a permanent record is concerned in paragraph 4.1, we feel that

it should be a specified number of years or stated per P.O.

Finally, it can be said that we will support the intent of this document

providing the revisions of our June meeting are made and the major question

concerning qualification and certification of the manufacturing house are

resolved between the U.S. Government and the prime contractor. Before giving

final acceptance FAG would like to see the finalized specification.

SPECIFICATION FOR REWORK AND RESTORATION OF AIRCRAFT ENGINE AND POWER

TRANSMISSION CYLINDRICAL ROLLER AND BALL BEARINGS

As the question concerning liability is still not a cut and dry subject, FAG

feels that rework and restoration of bearings should only be done by certified

aircraft bearing manufacturers.

precision ball & roller bearings

173

(cont'd)
FAG BEARINGS CORPORATION

Page 2

June 28, 1983

Arthur S. Irwin Co., Inc.

Bemus Point, New York 14712

Attention: Mr. Arthur S. Irwin, President

REF: FAG Comments Regarding June 1, 2, 1983 Industry

Coordination Meeting

As liability is a prime concern the specification should address this subject

to at least some degree.

The same comments regarding qualification as stated in the "specification for

ball and cylindrical roller bearings" apply here. The P.C. should be involved

in this process at least as a coordinator.

Another comment regarding this specification is that an additional technical

document must be formulated related to engineering specific requirements

controlling refurbishment.

In the definition section although it may be picky the definition of a "ball"

is left out and the "roller" definition is not specific enough.

Section 10.2.e (refurbishment) should be restated to read "honing (superfinishing)

of raceways (not to exceed .00015" total metal removal per surface) as well as

polishing of all active and inactive surfaces (not to exceed .00008" in total

metal removal per surface) .

In paragraph 5.1 the permanent record should be specified to a certain number

of years or stated on the P.O.

Finally, the subject of part marking must be further addressed as well as

acceptable number of times a bearing can undergo "restoration".

Finally, FAG will support this document providing the June meeting comments as

well as those stated above are taken into account and providing the coordinated

engineering drawings are submitted for approval. Before giving final acceptance

FAG would like to review the finalized specification.

Sincerely,

Ron M. Biroscak

Aircraft Sales Engineer

RMB:dn

174
GENERA L 0 ELECTRI C

AIRCRAFT ENGINE BUSINESS GROUP

GENERAL ELECTRIC COMPANY • 1000 WESTERN AVENUE • LYNN, MASSACHUSETTS 01910 • (617) 594-0100

September 6, 1983

Subject: Specification, Ball/Roller Bearing.

Specification, Refurbishment/Restoration.

Arthur S. Irwin Co. Inc.

Driftwood

Bemus Point, N. Y. 14712

Gentlemen:

In response to your request to express a position on the subject specification

effort, the following comments reflect our appraisal of the matter.

In general we agree with the intent of the effort to more precisely describe

and control precision bearings for use by the military where this description

and control has been absent in the past.

At the present time, our drawing and specification system encompasses all of

the material addressed by the two proposed documents, and therefore they are

considered to be superfluous in our case. The worry item here is the tendency

for the proposed specification to request not only the required information

sought but also impose specific limits. This is contrary to most documents

of this nature and can lead to conflict and complicated contract negotiations.

The subject specifications should also include wording to the effect that

existing drawings and specifications meeting the intent of the proposed

specifications are acceptable and may be used in lieu of these proposed specifications.

Yours truly,

C. B. PINEO, Principal Engineer

Bearings & Lube Systems Technology

IMZ 240G7, ext 4784

/m

cc JC Clark, H62, Evendale

PA Chipouras, Manager-Lynn Products Eng'g Dept., 240G6

175
INDUSTRIAL TECTONICS, INC.

18301 SANTA FE AVENUE, RANCHO DOMINGUEZ, CA 90224 • (213) 537-3750

MANUFACTURER S OF PRECISION BALLS AND BEARING S

bearing division

June 24, 1983

Arthur S. Irvin Co., Inc.

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

Industry Coordination Meeting on Contract NAS 3-23520

(a) Specification for Ball and Cylindrical Roller Bearings.

(b) Specification - Rework, Refurbishment and Restoration

of Aircraft Engine and Power Transmission Cylindrical-Roller

and Ball Bearings.

Gentlemen:

It was a pleasure to attend the meetings of June 1 and 2, 1983. I

felt that all participants offered constructive critiques, worthy of

your consideration.

My written comments are somewhat delayed due to interference by

several schedule-sensitive projects. Hope they can still by considered in your final evaluation. Generally I feel tha*t the specs will

be accepted by the industry if the major comments offered at the

meeting are incorporated. The following critique includes some rather

major points which should be addressed, as well as a few harmless

editorial suggestions.

(a) Specification for Ball and Cylindrical Roller Bearings.

Paragraph 2. Applicable Documents: As mentioned in my earlier letter

the specification should indicate in what way the listed documents

are to apply. The present text contains specs not listed in para. 2.1,

Conversely, this paragraph lists several specs which are never implemented by the text. We also recommend that the latest document

revisions at the time of a RFQ apply to the pertaining contract.

Paragraph 3.1.1. Bearings which have been out of production for

four years should require requalification only if the results of a

vendor quality audit indicate the need for requalification.

Paragraph 5. Rejection: The third sentence could be rephrased as

follows: "Bearings may be disassembled, components reworked, and

reassembled when done in accordance with established procedures."

176
Arthur S. Irvin Co., Inc.

June 24, 1983

Pace 2

Paragraph 6. Change Control: "There may be no significant change to

the original design, material, tolerances, basic processes,..."

[Underlined sections denote inserted or changed wording in existing

text.]

Paragraph 7. "Process and Inspection Approval - Unless previously

accomplished, after award of.... This will include Quality Control

plans and all destructive and non-destructive test and inspection

methods."

Paragraph 7.2. Editorial comment: "...with the exception that processing may continue, based on verbal authorization to proceed..."

Paragraph 8. "Drawing requirements - the required characteristics....

Drawings shall consist of three sheets:

(a) Sheet I will define the bearing design, including the applicable

process data listed in this paragraph, and the outlined quality

control requirements.

(b) Sheet 2 will list bearing usage(s),...

(c) Sheet 3 ...

[Don't know why sheets 2 and 3 couldn't be combined.]

Paragraph 8.1.27 should be inserted after 8.1.9.

Paragraph 8.1.30. Suggest a maximum hardness also be spcified.

Paragraph 8.2. "...requirements listed in 8.1, the following data

shall be furnished for cylindrical roller bearings, as applicable;"

Paragraph 8.2.4. "Nominal roller P.P. flat length and centrality"

Paragraph 8.2.12. "Roller diameter and length variations within one

roller set"

Paragraph 8.3. Ball Bearing Requirements: A similar introductory

statement as used in paragraph 8.2 should be used (see also note

regarding 8.2, above).

Paragraph 8.3.11. "Bearing axial preload, if applicable."

Paragraphs 8.4.3. and 8.4.4. - There is a need for clarification. ITI

made this same observation in the February 18, 1983, review.

INDUSTRIAL TECTONICS, INC.

177
Arthur S. Irvin Co., Inc.

June 24, 1983

Page 3

Paragraphs 8.4.11. and 8.4.12. should appear in paragraph 8.3.

Paragraph 8.4.13 - Delete, as this appears as 8.1.12.

Paragraph 10 - Prior to issuing this specification it is mandatory

that this section be reviewed by several steel manufacturers to

ascertain that commercially available material meets all the specified

requirements.

(b) Specification - Rework, Refurbishment and Restoration of Aircraft

Engine and Power Transmission Cylindrical-Roller and Ball Bearings.

Paragraph 2. Applicable Documents - Suggest the spec titles be added

to the associated numbers.

Paragraph 3. Qualification - Define "dynamic test."

Paragraph 3.1. Requalification - The same comment applies as for

paragraph 3.1.1 of spec for ball and roller bearings, above.

Paragraph 6. Rejection - See comments for paragraph 5 of spec for

ball and roller bearings, above.

Paragraph 7.1. It appears useful to have a means for requesting

changes during work on a contract.

Paragraph 10.1. (e) - Buffing and polishing of active surfaces

should be restricted.

Paragraph 10.3. Restoration should be preceeded by a detailed design

analysis of the modified geometry to assure that the restored bearing

will have same integrity as original design. This analysis must, as

a minimum, evaluate internal bearing geometry (radial and end play,

contact and shim angles as applicable) as well as cage-to-rolling

element interfaces (pocket clearances and interaction with retention

features).

Grinding of bearing surfaces should be performed only by qualified

bearing manufacturers.

Regrinding one raceway and replacing the mating ring, using new

standard-size rolling elements, should be listed as a viable option

to the process now shown.

INDUSTRIAL TECTONICS, INC.

178
Arthur S. Irvin Co., Inc.

June 24, 1983

Page 4

Paragraph 10.5. Identification should include a symbol or code indicating the level of rework and number of reworks performed.

Flowcharts, figures #1 and #2: The initial bearing inspection should

result in a decision regarding subsequent activities: either per 10.1

or 10.2 or 10.3. Hence, refurbishment (10.2) and restoration (10.3)

should be shown as parallel (either/or) activities rather than

in-series activities. It seems to make little sense to first refurbish a bearing and subsequently restore it.

The footnotes to figure #2 should be deleted. Instead refer to

applicable text in the body of the specification.

Appendix A - Glossary. Don't fully understand the value of this

section. Per your request, I am enclosing a copy, marked with minor

comments.

I'll be pleased to answer any questions you might have on the above.

Sincerely yours,

Hans R. Signer

Chief Engineer

HRS:lm

Enclosure

INDUSTRIAL TECTONICS, INC.

179
__._. .«,, Pace -5-

ORIGINAL PAGE SS

Si POOR QUALITY

APPENDIX A - GLOSSARY

AA - Finish:. Arithmetic Average - a numerical value of surface finish

obtained by measuring the vertical distance from the mean line of an irregular surface to the profile in the same manner as with RMS, adding

these measurements and dividing by the number of measurements.

A3EC 1, ifeDEft ABEC 5, ABEC 7, ABEC 9: Annular Bearing Engineers

Committee (AF3MA) designations indicating degrees of ball bearing precision.

Absolute Filters: Filters capable of filtering out given size particles

with near 100% efficiency.

Active Surfaces: The contact areas on the rings and rolling elements

that ere generated as the bearing is rotated.

AFBMA: Anti-Friction Bearing Manufacturers Association

Angular-Contact Bearing: A type of ball bearing whose internal clearances

and bell raceway locations are such as to result in a definite contact

angle and predetermined relationship of inner to outer ring faces.

AN.'SI: America! National Standards Institute

Antif

 r!ct'on Searing: A bearing using rolling elements such as balls, rollers

or needles.

AOL: Acceptable Ouality Level -is a va'ue' specif ied for a type or grouo of

defects characteristics of an item or product. The specified AOL value

(examp'e - AOL of 0.4) is referred to in the appropriate sampling plan

tat'e cf MIL STD 105. The number of defects for each AOL "is then obtained that will determine whether to accept or reject the lot.

Axis ' Clearance: see End Piay

force. ti> li^-t. tf?lkAxi.g' Leg. fThrvst): Pf ooiu'c applied to the bearing parallel tu the bearing

aziF. ~~~

Sack-to-Back Assembly: A c'ur'ex pair of matched ball beanngs with [ I'

o'_:er r-;ng back? adjacent. C

Ball Complement: Size and number cf balls used in a baj! bearing.

ng Axis: The '"-.aginary center line about which the outer or inner

w

Jno Stack: Matched mu't'iple assembly cf two or more beanngs.

S. IRWI N CO. I >C.

Point. NY l*7i:

:-°"> Consultants continued next paoe

..>ooc Center

180
Pace -5-

ORIGINAL PAGE IS

Bore Diameter: Inside diameter of inner ring. TM POOR QUALITY

Rino: Surfnrn 7ir9i of h

Bore, Out.er Ring: Inner diameter ourfoce or land area. <y

Boundary Dimensions: Dimensions for bore, outside diameter, width

and corner/vS).

Burnish: A luster or polish on a surface by friction or rubbing contact.

Cage (retainer, separator): A device, parfiaily surrounding the rolling

elements and traveling with them, with themain purpose of spacing the

rolling elements in proper relationship to each other.

Centrifugal: Moving or acting in a direction away from a center or axis^i.

Clearance. Axial: see End Play

Clearance, Radial: Radial internal clearance is the total diametrical movement of the undamped rina when the specified^load is reversed..

'£-.r*^>«jG

Cone: The inner ring of a tapered roller bearing.

Contact Ang!e: Ang!e between plane perpendicular to bearing aris and

line drawn between certers of contact of• balls to inner and outer ring

raceways.

Convex: A surface that is curved ir bulnrf outward ih the center.

Corrosion: A process which destroys the metal by chemical or* electrochemical action and converts it to an oxide, hydroxide, or sulfate compound.

C

r

ack: A break, fracture, fissure, crevice or separation in' the structure

of the. part.

C

r

itica ! Defect: A defect that iudcment and exoerie.nce indicate is likelv

to result in Hazardous or unsafe conditions for individuals using, maintaining,

0' defending upon the product; or a defect that judgment and experience

indicate is likely to prevent performance of the tactical function of a

major end item sucK'as an aircraft, missile or space vehicle.

Crowned Rolle-: Having a ve-y large radius profile on both sides of a

straight "cylindrical center section to provide a modified line contact

with the raceways.

Defect: (discreDancy) Any deviation of a part frcm specified recuirerrersts.

APTKUR S. ;R»V;\ CO. T-C

Technology Consultants - continue d next pace

Center

Eenus Point. NY

181
Pace -7-

Diametra! Clearance: see Clearance, Radiai

Dimensional Stabi'ity: The decree of stability that hardened steel may

have to resist growth or permanent expansion ( a function of the amount of

retained austenite.)

Dup'ex Bearing: Matched set of two preloaded bearings.

Dynamic Balance: That condition in a rotating body where the mass

are coincident or the

Eccentricity (radial runout): Occurs when the center of one circular surface is not coincident (the same) as the center of another surface. Ex:

Nonuniform thickness between the bore and the ball groove of an inner

ring.

End P!ey (Test): The bearinp is to be lubricated with lipht oil and .one c* its fines

ciarnped to prevent axial movement, the specified reversing measuring

load is applied to the undamped ring so that resultant movement of that

ring is parallel to the bearing axis, the end play is the total movemento

x

 the unclamoec ring when the load is applied fi rst in one direction and

t^en the other.

c

'akinc: A condition of advanced/\f atigue where small pieces e* metal ere

loosened from the base material.

-lutinc: A form c* pitting in which pits occur in a regular pattern so as

tc 'crm transverse grooves or flutes in the raceway.

F-ettinc ( *ret wea-, fretting corrosion, false brine!!inc): The rapid abrasion that occurs at the interface between contacting, highly loaded metai

surfaces when subjected to vibratory motions or lew amplitude. Usually

accompanied by the formation of- oxides of the abraded metal.

G2'!i~c: ~he transfer of material from one surface to another dying

s

:

 ic'irc "contact.

Groove ^'jr-out with Reference Side, Inner r;nc: see Raceway Runout with

Reference S:c-e, inner Ring

Groove Runout wit1-

1

 Reference S;de. Cuter P^g: see Raceway Runout with

^ofgrpnce Sice, Cuter R:ng

Hardness: Resistance c* rretc! to plastically de'orm, determined by incentation.

He.'C^t o* Raceway S^ou'de-: We AJ^u' distance from bottom o*

A?T:-:I:? s. :R\V;N co. INT.

Technology Consu'tcnrs continue d next page

c Ccr.rcr

T-crnus Pc!r:. N

182
ORIGINAL PAGE IS

OF POOR QUALITY ^

to inner ring outer diameter or outer ring diameter (same as race depth).

indusicn: A-void, discontinuity, cr solid foreign particle in the molecular

structure of metal.

inner Race: Raceway cf inner ring

inne1- Ring: The inner component of a bearing.

Inside Diameter: Dimension across center of ring bore. May be used to

express dimension across bore of snap ring, shield, seal, etc.

inspection: The process of measuring, exemining, testing, or ~therwise

comparing the unit or product (bearing) with the requirement.

Inspection. Quality Conformance (CO!): Ai! examinations and tests pe-fcrmed

f

cr the purpose of determining conf ormance, with specified requirements.

inspection, "00°/c: An inspection in which Specified characteristics of each

bearing are examined or tested to determine conformance with recuirem't ts.

'nterna' C!earance: see Clearance, R&dial

Ls^ds: The flat surfaces on both sides of the raceway or rings.

Lane Ric'inr R-taine': A ret?.;ner guided by either the inn.er ring o1

Lacs: Discontinuities or irregu'enties in tKe material as a result of

Lay; Direction cf the p-ec'c^nant surface pattern.

Loading Groove (*!!i:~g s'ot): Notch

 ;n raceway to permit assemb'.y o* a

maximum number of rc.:iinc elements.

Lcerise Grocv e Bea'inc: A bea.'ing cf maximum capacity type, in which

f--ere is int'ocucec. by means cf a filling s'ot or Icac'inc crocve, more bal's

cr 'o'!ers that can be inco-oorated in a non-fi!!ing siot or Conrad-type bearir

Lot: This term shall mea^ "inspection Lot", a cc'iection of bearings

or Kits *'om v;hich a sample is tc be drawn and inspected to determine

ccn'ormance with the acceptability criteria.

Lot ?;ze: The lot size is t'ne rvji-ber of bearincs in a lot.

Vajc r Defeat: A de'ect pthe- t^en critical, that is like'y to resu't

f s : ; u<"e. c: t; materia!:y reduce t^e useb-Mity o* the product for its

•JR s. :RW:\ co. INC.

Driftwood Cer,;cr

.<. ?o:r.;. NV U'

183
rage -£-

tended purpose.

Msrter.site: A phase of steei witn a body-c-enterec crystalline structure

cnaracterized by a needle like micrcstructure.

N/iatcr.ing: Inner and cuter rings in dupiex/^sets -r.at £re matched fo.-Abcre

O.D., and eccentricity, within specified tolerances.

Micron: One millionth of a meter, 1 micron equals .00003957 inches.

Minor Defect: A oefect that is not likely to materially reduce the usability of the bearing for its intended purpose, or is a departure from

established standards having minimal bear lag on the effective use or operation of the unit.

Nominal: Approximate or rated value.

Outside Diameter Squareness with Side (Test): One sice of the outer ring is supported on a flat plate of suitable dimensions (with inner ring free) anc held

against a stop located close to tne lower corner of the outside diameter. The

indicator is applied directly above the stop c.os'e to the upper corner of

the outside diameter. The deviation from the outside diameter squareness

with side is the difference between the rninimum and maximum reading of

the indicator when rotating the outer ring or.e revolution.

Fareiielism of Sices: The difference between the largest and sma;;est

width of the bearing rings.

Participate: Existing in the form of very srr.au separate particles.

Periphery: The external boundary or surface of a body.

Pitch Diameter. Rolling Ele.mer.ts: The diameter of tne center line

of the roiling e.err.ents.

Pitting: Minute removal cf r'i~mTQi r* cul surfaces througr. fatigue,

corrosion or electrical arcing.

Plastic Fiow: Deformation that permanently remains after removing the

load whicn caused it.

Pocket. Cage: That portion of cage which is shaped to receive the roij.i

element.

Precision: The degree of agreement of repeatec measurements of a qu&

AX7;-:U3 S. IRWIN CO. INC.

 tity' Corr*£:e with

 accuracy.

Technology Cor.suitints

Drifrwooi Center continued next page

Pol.-.:. NY I47i2

184
ORIGINAL PAGE IS

©F POOR QUALITY

p

,~ ~^-

3

'?;oad: /\vv"ust icadingfa bearing in a unit to increase rigidity. Preloadin

' •-"•--•"- /J /J .£ ' , •K - y *> 'binq th e initial portion

that t^o djfiget'on iu muie. oi.ifui

Processed Bearing: A bearing that has been used and then cleaned, inspected,

caged, tested and preserved for additional use.

Profile: The contour (external outline) of a surface in a plane perpendicula- (right angle) to the surface.

Profile (measured): A representation o* the profile abtained by instrumenta;

 means.

CC-L: Quality Characteristics List

Race: see Rinc

Raceway: The contact path of the rolling element on rings of rowing

Raceway Diameter: Diameter c* the inner or outer ring raceway of a

bearinc.

Raceway, Inner Ring: Ti

r inc.

Raceway, Outer Ring;

rinc .

-groove

 fpr rolling elements in the inner

groove for roMing elements in the outer

Raceway Runout with Reference Side, Inner Ring (Test): Mount bearing on arbor

having a very slight taoer (preferably 0.0001 to 0.0002 in. on the diameter

per inch of length). Support outer ring in horizontal position and apply

indicator to side of inner rina. The deviation from groove parallelism with

s

:

de is the difference between the maximum and minimum reading when

rctat;r*g the arbor one revolution.

Raceway Runout with Reference Side, Outer Ring (Test): Mount bearing on arbor

naving a very slight taper (preferably 0.0001 to 0.0002 in. on the diameter

per inch of length). Acp'y a true rtunning weight to- the outer ring. Support

arbor in a vertical position and apply indicator to side of outer ring. T^e

deviation from groove parallelism with side is the difference between tKe

maximum and minimum reading when rotating outer ring one revolution.

Radial C'earance: see Clearance, Radia!

AP.THVR S. IRWIN CO. INC.

Technology Consultants

Drif:woo<I Center

ECT^S Pont.' NY \4~7\ 2

continued next oaoe

185
_

to the bearing axis.

Radial Runout (Test): Mount bearing on arbor havina a verv sliaht taoe<- (C.OC01

to C.C-OC2 in. on diameter per inch of length). Apply indicator on center of

stationary cuter ring. The radial runout is the difference between the

m'-i'mum and maximum reading when rotating the arbor one revolution. Corrections should be made for the inaccuracy of the arbor.

Radia1 Ty^e Bearing: A roll ing^bearlng primarily designed to support a

•

r

ac;ai icac! peroencicu'ar to shaft axis.

i inc:Dlan for choosing sarro'e units in a random or nonreo'jlar pattern

fcr quality inspection.

Rating Life (L-jp): Number of hours at a given speed that 90% of a group

o~ icenticai bearings wil l atain or exceed before the first indication of

fatigue cracking or spacing.

R5EC 1, R8EC 5: Designations indicating degrees of roller bearing precision.

Roller Bearing Engineers Committee (AFBMA)

Refin'sh: To restore an existing surface finish without removing all the

ex:stirg finish.

Refurb!sh: To repair beamings by replacement o^worn and/or defective

carts, a* ' ~~

Restoration: To 'return a bearing to original assembly print dimensions

by rec'inding raceways and "rebuilding with oversize rolling elements.

'r?eta ci"*ed austenite ohase remaining in steel after

;

ned Austenite : -Ue«

neat treat:ng to ootain the harder, more fatigue resistant rrartensitic steel.

Reta' re" : see C a c 5

Rework : : ue overall procedure for cleaning, reworking, refurbishing,

 resto'i^c and reissuing of used or rejected bearings.

Rockwel l Hardness Test: A test for determining the hardness of a material

based on the c'errth of penetration of a spec'r;ec penetrator into the specimen under soecified load conditions.

I

R o!-er: Load-carrying, ""ciiinp element.

A?,TXL?. S. IRVVIN CO. INC.

Teeh,-.o!'o2y Consuirartts

D."i'"."-»ood Center

3o-.s Point. NY 14712

continued ^ext cace

186
ORIGINAL PAGE IS

 Pa"e

 ~

1 2

~

OF POOR QUALITY

aoo.

R c' i g r Co~p!ement: Sire and number c* rollers in a -bearing.

Rcl'e'r Diameter; Maximum circular ciimonciono-of straight rollers.

R-o:!er Lenct'v Distance between the ends or faces of the roller.

Rc-'Hnc 3eari

n

a: A bearing usi"g

 ro!!'n

g elements such as balls, rollers,

z~ neec'es :? reduce friction and to support load.

R'jnCL't: """hs amount ^at O"9 ?'.""^?T°

 lg^^g

 rf ^B:no truo with

!

jnput. R^di 3': se^ Rac'is' Ru^cut

e: A sample consists of one cr more parts drawn from a lot.

;5Tts be;ng se'ected at randcm without regard to their quality.

oc P!an: A sam.plinc plan indicates the number of bearinas f'om

sac'"1 Tot w^ ;c h are to be inspected and t:ne criteria for determining the

acceptability of the lot.

Scratc'''?5: Linear abrasions on tie S'j'face.

Sc'jffs: A series of small s^ce-^lcia! or shallow scratches.

Serarabie: A bearing assembly that ~^ay be -separated comp'etely or

its ccmponent..

see Cace.

S:c'° R-"0'.'t. Inne'.Rinc (Test): Vount bearing on arbor having a very sl'gh

:ace" (C.OCC'1 to O.CCC2 in. on diameter per inch of length). Apply indicate.' Hca:

n;t s:de cf :nne

r

 r;nc. "!"^e s:de

 ru".0'jt Is the difference between

the maximum and mini^uT1. read'ng when rotation the arbcr cne revclut

:

on.

S'<ew: Sla^t, twist, nonsymet'ical, non.'jniform distribution.

- —3^- fl*«.

S""ear:ng or Pickup: Removal cx raceway,9P- bal/^material -d*e to skiddi-c

co~~2c c ana its red:sccsition at another point in t^e form of smear.

Sca;'.;ng: Actual removai of material •'rom raceway cr rcl'ino element

surfaces in t^e *crm of flakes ,

 resu!t;

ng In cavities - 'aticue re'ate-d.

.:.-. ?. :?.\v:\ cc. INC.

3.-;.":v.-:.od C«:;r """"' ^~e~ "^' ^^^

..- Point, NY ;.;-;;

187
Page -13-

Scuareness of O.D./3ore with Face: The squareness (90° angle) of the face

w • t ~ t n s outside diameter/ bo^e of i ring.

Staking: A method of retaining a bearing by disnlacina housing material over

the chamfer.

Sta;ns: Surface discoloration.

Standg.-c: A physical or numerical limit which is used as a reference.

• -lug cage = physical and a surface roughness limit = numerical).

Statistical: Cf, relating to, or dealing with the collection and analytical

irte'pretation of numerical data.

S-jcerricia!: Effecting only the surface of an object.

Surface Texture: Repetitive or random deviations from the nominal surface which form the pattern cf the surface. Includes roughness, waviness,

lay and flaws.

Tandem Duplex Mounting: Assembly of two cr more ball bearings mounted

sc as to divide the thrust load.

Tarnish: A stain on the surface.

Temper; To soften hardened steel by reheating at a temperature betow

the hardening temperature.

"hrust Searing: A ball or roller bearing with space between rings orie^tec pe-pencicular to the axis of rotation. It is primarily intended to

carry thrust loads.

Used 3earinc: A bearing that has seen service and has been subjected to

cserating leads.

Width. Inner Ring: Dimension across the inner ring.

Width, Outer Ring: Dimension across the cuter ring.

A.rr:-:v3 s. ;R\VIN co. INC.

Tcch.-.o.'ogy Consulranrs

"ri'cwood Center

:;-r^us ?oin:. NY IiTJ2

188
Phone (616

286

)

0

Muskegon

 755-374

 McCracken

1

, Michiga

 Tele

, P.O

x

.

 22-843

 Bo

n 4944

x 688

3

6

 CORPORATIO

 — KAYDON

N

June 3, 1983

Mr. Arthur s. Irwin

Arthur S. Irwin Company, Inc.

Driftwood

Bemus Point, NY 14712

Subject: Industry Coordination Meetings on NASA Contract

NA53-23520

Dear Mr. Irwin:

Having now attended the concluding two sessions of subject meetings

I offer the following comments, which may be regarded as the official

position of KAYDON CORPORATION with respect to the Qualification

and Procurement Specification as well as the Rework, Refurbishment,

and Restoration Specification:

1. Despite the many differing opinions expressed, there

was near-unanimous agreement on all important issues.

2. Assuming amendment as generally agreed the specificaions

will be useful documents which should serve well their

intended purpose. In answer to Martin Joseph's question,

we would respond positively to RFQ's subject to the

specifications.

3. Because of the importance of three amendments, I recite

here my understanding of the essence of the general

consensus:

a. Recertification by Quality Audit by the original

contractor is an acceptable alternate to testing

to requalify a bearing manufacturer that has not

made a particular bearing for four years or more.

b. in Par. 7 of the Qualification and Procurement

Specification, processes and inspections should

also be approved by the prime contractor.

c. To the RR&R specification should be added the

requirement for specific engineering documentation

of allowable modifications of the bearing at issue.

Such documentation may be prepared by the prime

contractor or by the RR&R manufacturer and shall be

approved by the contracting agency.

FOLLOWING ARE OUR REGISTERED TRADEMARKS - YOUR ASSURANCE OF KAYDON QUALITY

KAYDON Endura-Slim Lami-Seal Endurakote WireX

Reali-Slim Reali-Seal Lami-Shield Thin-Shell Bowser

189
KAYDO

CORPORATIO

N

N

Arthur S. Irwin Company, Inc.

June 3, 1983

Page 2

In accordance with your request I also attach herewith a copy of

the Glossary marked up with our suggested revisions.

Art, it's been a pleasure and privilege working with you on this

important project. Also, I believe Bill Derner should be

commended for both his excellent editorial work as well as his

masterful monitoring of the work sessions. And last, but not

least, let's give a hearty "thanks" to Barb Metcalf for all her

behind-the-scenes assistance in making everything run smoothly.

Sincerely,

KAYDON CORPORATION

Richard F. Gej

Vice President Engineering

ss

cc: T. Bushar/K. Harestad/R. Laferriere

M. Hoard/P. VanGennep

Enclosures

190
Page -5-

APPENDIX A - GLOSSARY

AA - Finish:. Arithmetic Average - a numerical value of surface finish

obtained by measuring the vertical distance from the mean line of an irregular surface to the profile in the same manner as with RMS, adding

these measurements and dividing by the number of measurements.

ABEC 1, ADCC 0, ABEC 5, ABEC 7, ABEC 9: Annular Bearing Engineers

Committee (AFBMA) designations indicating degrees of ball bearing precision.

Absolute filters: Filters capable of filtering out given size particles

with near 100% efficiency.

Active Surfaces; Tho -contact aroac on tho rinyu and ilrtllny elements .

t-hnt tirr gpnpratod nn the hoaring jp rctotrrt, •*?*—•' +,**$•». +*-«. ri~g*, r»K'^ « _

5<""i*.«-« i~. fo Hi»<j «*• fl'id,'** mefidw «s •*-!•.«

4Ue %/

Ball Complement: Size and number of balls used in a ball bearing.

Bearing Axis: The imaginary center line about which the outer or inner

ring will turn.

Bearing Stack: Matched multiple assembly of two or more bearings.

ARTHUR S. IRW1N CO. INC.

Technology Consultants ..

Driftwood Center continu<

Betnus Point. NY I47I2

191

AFBMA: Anti-Friction Bearing Manufacturers Association

Angular-Contact Bearing; A type of ball bearing whose internal clearances

and ball raceway .locations are such as to result in a definite contact

angle and predetermined relationship of inner to outer ring faces.

ANSI: Americal National Standard? Institute

or

Antifriction Bearing: A bearing using rolling elements such as ballsA rollers

or noodloo.

AQL; Acceptable Quality Level is a value specified for a type or group of

defects characteristics of an item or product. The specified AQL value

(example - AQL of 0.4) is referred to in the appropriate sampling plan

table of MIL STD 105. The number of defects for each AQL is then obtained that wilt determine whether to accept or reject the lot:

Axial Clearance: see End Play

Axial Load (Thrust): Pressure applied to the bearing parallel to the bearing

aris.

a*qu.U/ <*n4-AC^"

Back-to-Back Assembly: A duplex pair of matched ball bearings w+*fc-n/Jie*« ]•'««•

outor nng-booko-edjeeent. j* <*«>'•>« +te *»• 'l/r««-*u>«y poi«k of c.«*rt~*c.+ ;*-h?rsrc

'
Page -6-

Bore Diameter: Inside diameter of inner ring.

Bore, Inner Ring: Surface area of bore diameter.

Bore, Outer Ring: Inner diameter surface or land area.

Boundary Dimensions; Dimensions for bore, outside diameter, width

and corner (s).

Burnish: A luster or polish on a surface by friction or rubbing contact.

_^__«_^_«_— /V

Cage (retainer, separator): A device, partially surrounding the rolling

elements and traveling with them, with theme** purposes of spacing the

rolling elements in proper relationship to each other, o.<n

'

Centrifugal: Moving or acting in a direction away from a center or axis.

Clearance, Axial: see End Play

Clearance, Radial: Radial internal clearance is the total diametrical, movement of the undamped ring when the specified load is reversed..

Cone: The inner ring of a tapered roller bearing.

Contact Angle: Angle between plane perpendicular to bearing axis and

line drawn between centers of contact of balls to inner and outer ring

raceways.

Convex: A surface that is curved or bulged outward in the center.

Corrosion: A process which destroys the metal by chemical or electrochemical action and converts it to an oxide, hydroxide, or sulfate compound.

Crack: A break, fracture, fissure, crevice or separation in the structure

of the part.

Critical Defect: A defect that judgment and experience indicate is likely

to result in hazardous or unsafe conditions for individuals using, maintaining,

or depending upon the product; or. a defect that judgment and experience

indicate is likely to prevent performance of the tactical function of a

major end item such as an aircraft, missile or space vehicle.

Crowned Roller: Having a very large radius profile on both sides of a

straight cylindrical center section to provide a modified line contact

with the raceways.

Defect: (discrepancy) Any deviation of a part from specified requirements.

ARTHUR S. IRWIN CO. INC.

Technology Consultants continued next page ......................

Drifcwood Center

Bcmus Point. NY 14712

192
ORIGINAL PAGE IS Page -7-

OF POOR QUALITY

Diametral Clearance: see Clearance, Radial

Dimensional Stability: The degree of stability that hardened steel may

have to resist growth or permanent expansion ( a function of the amount of

retained austenite.)

Duplex Bearing: Matched set of two preloaded bearings.

Dynamic Balance: That condition in a rotating body where the mass axis

are coincident or the same.

Eccentricity (radial runout): Occurs when the center of one circular surface is not coincident (the same) as the center of another surface. Ex:

Nonuniform thickness between the bore and the ball groove of an inner

ring.

End Play (Test): The bearing is to be lubricated with light oil and one of its rings

clamped to prevent axial movement, the specified reversing measuring

load is applied to.the unclamped ring so that resultant movement of that

ring is parallel to the bearing axis, the end play is the total movement

of the unclamped ring when the load is applied fi rst in one direction and

then the other.

Flaking: A condition of advanced fatigue where small pieces of metal are

loosened from the base material.

Fluting: A form of pitting in which pits occur in a regular pattern so as

to form transverse grooves or flutes in the raceway.

Fretting ( fret wear, fretting corrosion, false brinelling): The rapid abrasion that occurs at the interface between contacting, highly loaded metal

surfaces when subjected to vibratory motions or low amplitude. Usually

accompanied by the formation of oxides of the abraded metal.

Galling: The transfer of material from one surface to another during

sliding contact.

Groove Runout with Reference Side, Inner ring: see Raceway Runout with

Reference Side, Inner Ring

Groove Runout with Reference Side, Outer Ring: see Raceway Runout with

Reference Side, Outer Ring

Hardness: Resistance of metal'to plastically deform, determined by inc'entation.

Height of Raceway Shoulder: Vertical distance froir bottom of raceway

ARTHUR S. IRWIN CO. INC.

Technology Consultants continued next pace

Driftwood Center

Semus Point, NY 14712

c - b

193
Page -8-

to inner ring outer diameter or outer ring diameter (same as race depth).

Inclusion: A -void, discontinuity, or solid foreign particle in the molecular

structure of metal.

Inner Race: Raceway of inner ring

Inner Ring; The inner component of a bearing.

Inside Diameter: Dimension across center of ring bore. May be used to

express dimension across bore of snap ring, shield, seal, etc.

Inspection: The process of measuring, exemining, testing, or otherwise

comparing the unit or product (bearing) with the requirement.

Inspection, Quality Conformance (CQI): All examinations and tests performed

for the purpose of determining conformance with specified requirements.

Inspection, 100%: An inspection in which Specified characteristics of each

bearing are examined or tested to determine conformance with requirements.

Internal Clearance: see Clearance, Radial

Lands: The flat surfaces on both sides of the raceway or rings.

Land Riding Retainer: A retainer guided by either the inner ring or

outer ring.

Laps: Discontinuities or irregularities in the material as a result of working.

Lay: Direction of the predominant surface pattern.

Loading Groove (filling slot): Notch in raceway to permit assembly of a

maximum number of rolling, elements.

Loading Groove Bearing; A bearing of maximum capacity type, in which

there is introduced, by means of a filling slot or loading groove, more balls

or rollers that can be incorporated in a non-filling slot or Conrad-type bearing.

^ This term shall mean "Inspection Lot", a collection of bearings

or l<its from which a sample is to be drawn and inspected to determine

conformance with the acceptability criteria.

Lot Size: The lot size is the number of bearings in a lot.

Major Defect: A defect other than critical, that is likely to result in

failure, or to materially reduce the usability of the product for its inATTHl.'2 S. nWlN CO. INC.

Technology Consultants

Drir;woo<! Center

Bcmus Pom'. NY K712

194
ORIGINAL PAGE IS Page -9-

OF POOR QUALITY

tended purpose.

Martensite: A phase of steel with a body-c-entered crystalline structure

characterized by a needle like micro-structure.

Matching: Inner and outer rings in duplex sets that are matched for bore

O.D., and eccentricity, within specified tolerances.

Micron; One millionth of a meter- 1 micron equals .00003937 inches.

Minor Defect: A defect that is not likely to materially reduce the usability of the bearing for its intended purpose, or is a departure from

established standards having minimal bearing on the effective use or operation of theunit.

Nominal: Approximate or rated value.

Outside Diameter Squareness with Side (Test): One side of the outer ring is sopported on a flat plate of suitable dimensions (with inner ring free) and held

against a stop located close to the lower corner of the outside diameter.

indicator is applied directly above the stop close to the upper corner of

the outside diameter. The deviation from the outside diameter squareness

with side is the difference between the minimum and maximum reading of

the indicator when rotating the outer ring one revolution.

Parallelism of Sides: The difference between the largest and smallest

width of the bearing rings.

. Particulate: Existing in the form of very small separate particles.

Periphery: The external boundary or surface of a body.

Pitch Diameter, Rolling Elements: The diameter of the center line

of the rolling elements.

Pitting: Minute removal of raceway of ball surfaces through fatigue,

corrosion or electrical arcing.

Plastic Flow: Deformation that permanently remains after removing the

load which caused it.

Pocket, Cage: That portion of cage which is shaped to receive the rolJ.ing

element.

Precision: The degree of agreement of repeated measurements of a quanARTHUS S. IRWIN CO. INC.

 tjty- ComPare with

 accuracy.

Technology Consultants

Driftwood Center continued next page

Bcmus Point, NY 14712

195
Page -10-

Preload: Thrust loading a bearing in a unit to increase rigidity. Preloading

decreases deformation and deflection by absorbing the initial portion of the

deflection curve which is steep and increasing at a high rate. The result fs

that the deflection is more uniform and« has less magnitude throughout

the loading range.

Processed Bearing; A bearing that has been used and then cleaned, inspected,

gaged, tested and preserved for additional use.

Profile: The contour (external outline) of a surface in a plane perpendicular (right angle) to the surface.

Profile (measured): A representation of the profile abtained by instrumental means.

QCL: Quality Characteristics List

Race: see Ring

Raceway: The contact path of the rolling element ori rings of rolling

bearing.

Raceway Diameter: Diameter of the inner or outer ring raceway of a

bearing.

Raceway, Inner Ring: Track or groove for rolling elements in the inner

rino.

Rac-eway, Outer Ring;

ring.

Track or groove for rolling elements Jn the outer

Raceway Runout with Reference Side, Inner Ring (Test): Mount bearing on arbor

having a very slight taper (preferably 0.0001 to 0.0002 in. on the diameter

per inch of length). Support outer ring in horizontal position and apply

indicator to side of inner ring. The deviation from groove parallelism with

side is the difference between the maximum and minimum reading when

rotating the arbor one revolution.

Raceway Runout with Reference Side, Outer Ring (Test): Mount bearing on arbor

having a very slight taper (p'efersbly 0.0001 to 0.0002 in. on the diameter

per inch of length). Apply a true ruunning weight to. the outer ring. Support

arbor in a vertical position and apply indicator to side of outer ring. The

deviation from groove parallelism with side is the difference between the

maximum and minimum reading when rotating outer ring one revolution.

Radial Clearance: see Clearance, Radial

A7.THUR S. IRWIN CO. INC.

Technology Consultants

Driftwood Center

Bemus Point, NY 14712

continued next page

196
ORIGINAL PAGE IS

OF POOR QUALITY Page -11-

Radial Load: Pressure applied to the inner or outer rings perpendicular

to the bearing axis.

Radial Runout (Test): Mount bearing on arbor havino. a verv slioht tan«r (0.0001

to 0.0002 in. on diameter per inch of length). Apply indicator on center of

stationary outer ring. The radial runout is the difference between the

minimum and maximum reading when rotating the arbor one revolution. Corrections should be made for the inaccuracy of the arbor.

Radial Type Bearing: A rolling bearing primarily designed to support a

radial load perpendicular to shaft axis.

Random Sampling:Plan for choosing sample units in a random or nonreoular oattern

for quality inspection.

Rating Life (Lip): Number of hours at a given speed that 90% of a group

of identical bearings will atain or exceed before the first indication of

fatigue cracking or spalling.

RBEC 1, R3EC 5: Designations indicating degrees of roller bearing precision.

Roller Bearing Engineers Committee (AFBMA)

Refinish: To restore an existing surface finish without removing all the

existing finish.

Refurbish: To repair bearings by replacement or worn and/or defective

parts and resurfacing any surface including raceways.

Restoration: To return a bearing to original assembly print dimensions

by regrinding raceways and rebuilding with oversize rolling elements.

Austenite: Unconverted austenite phase remaining in steel after

heat treating to obtain the harder, more fatigue resistant martensitic steel.

Retainer: see Cage

Rework: The overall procedure for cleaning, reworking, refurbishing, re-' .

storing and reissuing of used or rejected bearings.

RFI: Ready for issue.

el! Hardness Test: A tert for determining the hardness of a material

based on the depth of penetrst'on of a specified penetrator into the specimen under soecified 'cad conditions.

Roller: Load-carryinc rollinp element.

TXUa S. IRWIN CO. INC.

Tcchno.'ojy Consultants

Driftwood Center

3e,T,ns ?o:nt, NY 14712

continued next page

197
Page -12-

Roller Assembly: Rollers and cage.

Roller Complement: Rjje and number of rollers in a tearing.

Roller Diameter; Maximum circular dimensions of straight rollers.

Roller Length: Distance between the ends or faces of the roller.

Rolling Bearing; A bearing using rolling elements such as balls, rollers,

or needles to reduce friction and to support load.

Runout: The amount that one surface lacks of being true with another

surface of the same part.

Runout, Radial: see Radial Runout

Sample: A sample consists of one or more parts drawn from a lot,

the parts being selected at random without regard to their quality.

Sampling Plan: A sampling plan indicates the number of bearings from

each lot which are to be inspected and the criteria for determining the

acceptability of the lot.

Scratches; Linear abrasions on the surface.

Scuffs: A series of small superficial or shallow scratches.

Separable: A bearing assembly that may be separated completely or

partially into its component parts.

Separator: see Cage.

Side Runout, Inner Ring (Test): Mount bearing on arbor having a very slight

taoer (C.OC01 to C.C002 in. on diameter per inch of length). Apply indicator against side of inner ring. The side runout is the difference between

the maximum and minimum reading when rotating the arbor one revolution.

Skew: Slant, twist, nonsymetrical, nonuniform distribution.

Smearing or Pickup: Removal c<- raceway or ball material die to skidding

contact and its redisposltio" at another point in the form of smear.

3 pailipc: Actual removal of material from raceway or rolling element

surfaces in the forrp of flakes, resulting in cavities - fatigue related.

Solit Ball Bearing: A ball bearing having either one or both rings split

across the raceway so as to facilitate assembly.

A.TTHUR S. IRWIN CO. INC.

sy Consultants continued next page

Driftwood Center

 s

Scmt-s Point. NY I47I2

198
Page -13-

Squareness of P.P./Bore with Face: The squareness (90° angle) of the face

with the outside diameter/bore of a ring.

Staking: A method of retaining a bearing by disolacina housing material over

the chamfer.

Stains: Surface discoloration.

Standard: A physical or numerical limit which is used as a reference.

(Plug gage = physical and a surface roughness limit = numerical).

Statistical: Of, relating to, or dealing with the collection and analytical

interpretation of numerical data.

A

Superficial: Affecting only the surface of an object.

Surface Texture: Repetitive or random deviations from the nominal surface which form the pattern of the surface. Includes roughness, waviness,

!ay and flaws.

Tandem Duplex Mounting; Assembly of two or more ball- bearings mounted

so as to divide the thrust load.

Tarnish: A stain on the surface.

Temper: To soften hardened steel by reheating at a temperature betow

the hardening temperature.

Thrust Bearing: A ball or roller bearing with space between rings oriented perpendicular to the axis of rotation. It is primarily intended to

carry thrust loads.

Used Bearing: A bearing that h?.s seen service and has been subjected to

operating loads.

Width: The distance frcm ore face of inner ring to opposite face of

outer ring. •

Width, Inner Ring: Dimension across the inner ring.

Width, Outer Ring:. Dimension across the outer ring.

xua s. :R\V:N co. INC.

Technology Consultants

Drl.':wood Center

Point. NY 14712

199
To: r- -cvo Date:

 6

"L.

c

* •"!

ftcr > ^T v«ws. V*-r

T«»> " FW* U^WVf.WuAi'wM.A" •'* Wui-as ,

PRATT & WHITNEY AIRCRAFT GROUP

Government Products Division %rfiKSbuw«».

PWA 11136

200
ORIGINAL PAGE IS Page _5_

OF. POOR QUALITY

APPENDIX A -. GLOSSARY

AA - Finish:. Arithmetic Average - a numerical val.ue of surface finish

obtained by measuring the vertical distance from the mean line of an irregular surface to the profile in the same manner as with RMS, adding

these measurements and dividing by the number of measurements.

ABEC 1, ABCC 3} ABEC 5, ABEC 7, ABEC 9: Annular Bearing Engineers

Committee (AF8MA) designations indicating degrees of ball bearing precision.

jLbsoiute-Pinefs;—Filtpr«! rsmrhlr nf filliiiin'i nut '|i, ii r riartirlftt-

 fl—

of f irior|i-y

Active Surfaces: The contact areas on the rings and rolling elements

that are generated as the bearing is rotated.

AFBMA: Anti-Friction Bearing Manufacturers Association

Angular-Contact Bearing: A type of ball bearing whose internal clearances

and ball raceway locations are such as to result in a definite contact .. ,

angle and predetermined relationship of inner to outer ring faces, u**-n axv<ul ^ I0*-'

ANSI: America! National Standards Institute

Antifriction Beanng: A bearing using rolling elements such as balls, rollers

or needles.

AQL: Acceptable Quality Level is a value specified for a type or group of

defects characteristics of an item or product. The specified AQL value

(example - AQL of 0.4) is referred to in the appropriate sampling plan

table of MIL STD 105. The number of :defects for each AQL is then obtained that will determine whether to accept or reject the lot.

Axial Clearance: see End Play.

Axi-al Load (Thrust): Pressure applied to the bearing parallel to the bearing

azis.

Back-to-Back Assembly: A duplex pair of matched ball bearings with

outer r-ing backs adjacent.

Ball Complement: Size and number of balls used in a ba^l bearing.

Bearing Axis: The imaginary center line about which the outer or inner

ring will turn.

Bearing Stack: Matched multiple assembly of two or more bearings.

ARTHUR S. IRVVIN CO. INC.

Technology Consultants continued next page ..................

rifw

 s Driftwood Center

u.s Foin:. NY >47!2

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Page -6-

t

Bore Diameter: Inside diameter of inner ring.

•Sece^inaer-atogr—Surface OI-CQ of bore diomotcr.

 9—-

Bore, Outer Ring: Inner diameter surface or land area.

Boundary Dimensions: Dimensions for bore, outside diameter, width

and corner.(s). ~

-Duini&li:—A luster 6f polish on a t>ui face by friction or rubbing eontoct.18--—

Cage (retainer, separator): A device, partially surrounding the rolling

elements and traveling with them, with themain purpose of spacing the

rolling elements in proper relationship to each other.

Centrifugal: Moving or acting in a direction away from a center or axis.

Clearance, Axial: see End Play

Clearance, Radial: Radial internal clearance is the total diametrical movement of the undamped ring when the specified load is reversed.

Cone: The inner ring of a tapered roller bearing.

Contact Ancle: Angle between plane perpendicular to bearing axis and

line drawn between centers of contact of/balls to inner and outer ring

raceways.

Convex: A surface that is curved or bulged outward in the center.

Corrosion: A process which destroys the metal by chemical or electrochemical action and converts it to an oxide, hydroxide, or sulfate compound.

Crack: A break, fracture, fissure, crevice or separation in the structure

of the part.

Critical Defect: A defect that judgment and experience indicate is likely

to result in hazardous or unsafe conditions for individuals using, maintaining,

or depending upon the product; or a defect that judgment and experience

indicate is likely to prevent performance of the tactical function of a

major end item such as an aircraft, missile or space vehicle.

Crowned Roller: Having a very large radius profile on both sides of a

straight cylindrical center section to provide a modified line contact

with the raceways.

Defect: (discrepancy) Any deviation of a part from specified requirements.

ARTHUR S. IRWIN CO. INC.

Technology Consultants continued next page

Driftwood Center

Scmus Point, NY 14712

202
Page -7-

Diametral Clearance: see Clearance, Radial

Dimensional Stability: The degree of stability that hardened steel may

have to resist growth or permanent expansion ( a function of the amount of

retained austenite.)

Duplex Bearing: Matched set of two preloaded bearings.

Dynamic Balance: That condition in a rotating body where the mass axis

are coincident or the same.

Eccentricity (radial runout): Occurs when the center of one circular surface is not coincident (the same) as the center of another surface. Ex:

Nonuniform thickness between the bore and the ball groove of an inner

ring.

End Play (Test): The bearing is to be lubricated with liqht oil and one of its rings

clamped to prevent axial movement, the specified reversing measuring

load is applied to the undamped ring so that resultant movement of that

ring is parallel to the bearing axis, the end play is the total movement

of the unclamped ring when the load is applied fi rst in one direction and

then the other.

Flaking: A condition of advanced fatigue where small pieces of metal are

loosened from the base material.

Fluting: A form of pitting in which pits occur in a regular pattern so as

to form transverse grooves or flutes in the raceway.

Fretting ( fret wear, fretting corrosion, false brinelling): The rapid abrasion that occurs at the interface between contacting, highly loaded metal

surfaces when subjected to vibratory motions or low amplitude. Usually

accompanied by the formation of oxides of the abraded metal.

Galling: The transfer of material from one surface to another during

sliding contact.

Groove Runout with Reference Side, Inner ring: see Raceway Runout with

Reference Side, Inner Ring

Groove Runout with Reference Side, Outer Ring: see Raceway Runout with

Reference Side, Outer Ring

Hardness: Resistance of metalto plastically deform, determined by indentation.

Height of Raceway Shoulder: -Vertical distance from bottom of raceway

ARTHUR s. ;R\VIN co. INC.

Technology Consultants continued next page

Driftwood Center

Bcmus Point, NY I47I2

203
Page -8-

to inner ring outer diameter or outer ring diameter (same as race depth).

Inclusion: A-void, discontinuity, or solid foreign particle in the molecular

structure of metal.

Inner Race: Raceway of inner ring

Inner Ring: The inner component of a bearing.

Inside Diameter: Dimension across center of ring bore. May be used to

express dimension across bore of snap ring, shield, seal, etc.

OL.

Inspection: The process of measuring, exemining, testing, or otherwise

comparing the unit or product (bearing) with the requirement.

Inspection. Quality Confcrmance (CQI): All examinations and tests performed

for the purpose of determining conformance with specified requirements.

Inspection, 100%: An inspection in which Specified characteristics of each

bearing are examined or tested to determine conformance with requirements.

Internal Clearance: see Clearance, Radial

Lands: The flat surfaces on both sides of the raceway or rings.

Land Riding Retainer: A retainer guided by either the inner ring or

outer rina.

*•* •

Laps: Discontinuities or irregularities in the material as a result of working.

Lay: Direction of the predominant surface pattern.

Loading Groove (filling slot): Notch in raceway to permit assembly of a

maximum number of rolling, elements.

Loading Groove Bearing: A bearing of maximum capacity type, in which

there is introduced, by means of a filling slot or loading groove, more balls

or rollers that can,be incorporated in a non-filling slot or Conrad-type bearing.

Lot: This term shall mean "Inspection Lot", a collection of bearings

or kits from which a sample is to be drawn and inspected to determine

conformance with the acceptability criteria.

Lot Size: The lot size is the number of bearings in a lot.

N/lajor Defect: A defect other than critical, that is I'ikely to result in

failure, or to materially reduce the usability of the product for its inASTHUR S. IRWiN CO. INC.

Technology Consultants

Driftwood Center

Ecmas Poirt, NY 14712

204
Page -9-

tended purpose.

Martensite: A phase of steel with a body-centered crystalline structure

characterized' by a needle like microstructure.

Matching: inner and outer rings in duplex sets that are matched for bore t

O.D., and eccentri.city, within specified tolerances.

Micron: One millionth of a meter, 1 micron equals .00003937 inches.

Minor Defect: A defect, that is not likely to materially reduce the usability of the bearing for its intended purpose, or is a departure from

established standards having minimal bearing on the effective use or operation of theunit.

Nominal: Approximate or rated value.

Outside Diameter Squareness with Sice (Test): One side of the outer ring is supported on a flat plate of suitable dimensions (with inner ring free) and held

against a stop located close to the lower corner of the outside diameter. The

indicator is applied directly above the stop close to the upper corner of

the outside diameter. The deviation from the outside diameter squareness

with side is the difference between the rninimum and maximum reading of

the indicator when rotating the outer ring one revolution.

Parallelism of Sides: The difference between the largest and smallest

width of the bearing rings.

Sl__

-Particutate:—Cxit»liiiy in the fur in of'veiy amoll aeparote particlesT

•Pei iplmryr—Tliu BiAlcrnol boundary or surface of A uudyr—^—

Pitch Diameter, Rolling Elements: The diameter of the center line

of the rolling elements. '

Pitting: Minute removal of raceway of ball surfaces through fatigue,

corrosion or electrical arcing.

Plastic Flow: Deformation that permanently remains after removing the

load which caused it.

Pocket, Cage: That portion of cage which is shaped to receive the rolJ.ing

element.

Precision: The degree of agreement of repeated measurements of a quanARTHUR S. IRWIN CO. INC. ''^

 ComP£re with

 accuracy.

Technology Consultants

Driftwood Center continued next page

EC.-TIUS Point, NY 14712

205
Page -10-

Preload: Thrust loading a bearing in a unit to increase rigidity. Preloading

decreases deformation and deflection by absorbing the initial portion of the

deflection curve which is steep and increasing at a high rate. The result is

that the deflection is more uniform andi has less magnitude throughout

the loading range.

Processed Bearing: A bearing that has been used and then cleaned, inspected,

gaged, tested and preserved for additional use.

P-of ile: The contour (external outline) of a surface in a plane perpendi-

(right angle) to the surface.

Profile (measured): A representation of the profile abtained by instrumental means.

QCL: Quality Characteristics List

Race: see Ring

Raceway: The contact path of the rolling element ori rings of rolling

bearing.

Raceway Diameter: Diameter of the inner or outer ring raceway of a

bearing.

Ftaceway, Inner Ring: Track or groove for rolling elements in the inner

ring.

Raceway, Outer Ring: Track or groove for rolling elements in the outer

ring.

Raceway Runout with Reference Side, Inner Ring (Test); Mount bearing on arbor

"having a very slight taper (preferably 0.0001 to 0.0002 in. on the diameter

per inch of length). Support outer ring !n horizontal position and apply

indicator to side of inner ring. The deviation from groove parallelism with

srde is the difference between the maximum and minimum reading when

rotating the arbor one revolution.

F^aceway Runout with Reference Side, Outer Ring (Test): Mount bearing on arbor

"having a very slight taper (oreverably O.C001 to O.OC02 in. on the diameter

per inch of length). Apply a true ruunning weight to, the outer ring. Support

arbor in a vertical position and apply indicator to side of outer ring. The

deviation from groove parallelism with side is the difference between the

maximum and minimum reading when rotating outer ring one revolution.

Radial Clearance: see Clearance, Radial

ARTHUR S. IRWIN CO. INC.

Teclmoiogy Consultants continued next, page ...................

Driftwood Center

Dcmus Point. NY X712

206
ORIGINAL PAGE IS Page -11-

OF PbOR QUALFTY

Radial Load: Pressure applied to the inner or outer rings perpendicular

to the bearing axis.

Radial Runout (Test): Mount bearing on arbor having a very sliqht tansr f0.0001

to 0.0002 in. on diameter per inch of length). Apply indicator on center of

stationary outer ring. The radial runout is the difference between the

minimum and maximum reading when rotating the arbor one revolution. Corrections should be made for the inaccuracy of the arbor.

Radial Type Bearing: A rolling bearing primarily designed to support a

radial load perpendicular to shaft axis.

Random SamplingrPlan for choosing sample units in a random or nonregular pattern

for quality inspection.

Rating Life (L-|p)'- Number of hours at a given speed that 90% of a group

of identical bearings will atain or exceed before the first indication of

fatigue cracking or spalling.

RBEC 1, RBEC 5: Designations indicating degrees of roller bearing precision.

Roller Bearing Engineers Committee (AF3MA)

Refinish: To restore an existing surface finish without removing all the

existing finish.

Refurbish: To repair bearings by replacement or worn and/or defective

parts and resurfacing any surface including raceways.

Restoration: To return a bearing to original assembly print dimensions

by regrinding raceways and rebuilding with oversize rolling elements.

Detained Austenite: Unconverted austenite phase remaining in steel after

heat treating to obtain the harder, more fatigue resistant martensitic steel.

Retainer: see Cage

Rework: The overall procedure for cleaning, reworking, refurbishing, restoring and reissuing of used or rejected bearings.

RFI: Ready for issue.

Rockwell Hardness Test: A test for determining the hardness of a material

based on the depth of penetration of a specified penetrator into the specimen under specified load conditions.

Roller: Load-carrying rolling element, t^o.^ W<, c^l.'r.JncaJ , 4-«.p <• r e <1 «r

^>Kfl£? 6^O •

ARTHUR S. ,'RWIN CO. INC.

Technology Consultants

Drifcwood Center continued next page

Scrr.us Point, NY ',4712

207
Page -12-

Roller Assembly: Rollers and cage.

Roller Complement: Sjre and number of rollers in a -bearing.

Roller Diameter: Maximum circular dimensions of straight rollers.

Roller Length: Distance between the ends or faces of the roller.

Rolling Bearing: A bearing using rolling elements such as balls, rollers,

or needles to reduce friction and to support load.

Runout: The amount that one surface lacks of being true with another

surface of the same part.

Runout, Radial: see Radial Runout

Sample: A sample consists of one or more parts drawn from a lot,

the parts being selected at random without regard to their quality.

Samp'ing Plan: A sampling plan indicates the number of bearings from

each lot which are to be inspected and the criteria for determining the

scceptability of the lot.

Scratches: Linear abrasions on the surface.

Scuffs: A series .of small superficial or shallow scratches.

Separable: A bearing assembly that may be separated completely or

partially into its component parts.

Separator: see Cage.

Side Runout, !nne- Ring (Test): Mount bearing on arbor having a very slight

taper (O.OOC1 to O.COC2 in. on diameter per inch of length). Apply indica"-

tor against side of inner ring. The side runout is the difference between

the maximum and minimum reading when rotating the arbor one revolution,

Skewj Slant, twist, nonsymetrical, nonuniform distribution.

Smearing or Pickup: Rerrova! of raceway or ball material die to skidding

contact and its redisposition at another point in the form of smear.

Spalling: Actual removal of material from raceway or rolling element

surfaces in the form of flakes, resulting in cavities - fatigue related.

Split Ball Bearing: A ball bearing having either one or both rings split

across the raceway so as to facilitate assembly.

ARTHUR S. IRWIN CO. INC. '

josy Consultants continued next pace

'v-r.rtr? ICente e>n?ar ' ^ r

Serr.us Point. NY M712

208
RIGINAL PAGE IS

OF POOR QUALITY

Page -13-

Squareness of O.D./Bore with Face: The squareness (90° angle) of the face

with the outside diameter/bore of a ring.

Staking: A method of retaining a bearing by displacing housing material over

the chamfer.

Stains: Surface discoloration.

Standard: A physical or numerical limit which is used as a reference.

(Plug gage = physical and a surface roughness limit = numerical).

Statistical: Of, relating to, or dealing with the collection and analytical

interpretation of numerical data.

Superficial: Effecting only the surface of an object.

Surface Texture: Repetitive or random deviations from the nominal surface which form the pattern of the surface. Includes roughness, waviness,

lay and flaws.

Tandem Duplex -Mounting: Assembly of two or more ball bearings mounted

so as to/olvUie. the thrust load.

Tarnish: A stain on the surface.

Temper: To soften hardened steel by reheating at a temperature betmv

the hardening temperature.

Thrust Bearing: A ball or roller bearing with space between rings oriented perpendicular to the axis of rotation. It is primarily intended to

carry thrust loads.

Used Searing: A bearing that has seen service and has been subjected to

operating loads.

Width: The distance from one face of inner ring to opposite 'ace of

outer ring.

Width, Inner Fling: .Dimension across the inner ring.

Width, Outer Ring:. Dimension across the outer ring.

TKuS S. IRWIN CO. INC.

Technology Cor.suIta.Tis

Orif:woo(S Cenrcr

Serr.us Point. NY K7I2

209
PRATT & WHITNEY AIRCRAFT GROUP

East Hartford, Connecticut 06108

September 21, 1983

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, New York 14712

Attention: Mr. Arthur S. Irwin

Subject: Bearing Specifications -

. Ball and Cylindrical Roller Bearing Spec., Dated 8/10/83

. Rework, Refurbishment Spec., Dated 8/5/83

Reference: Letter, Arthur S. Irwin Co. to Bill Ironside, August 24, 1983

The revised bearing specifications have been reviewed. Since the specifications are being drafted for the U.S. Army, our Florida Operations

(Government Products Division) will provide a consolidated P&WA response

to the documents. If clarification or additional information is required,

please feel free to contact us.

Sincerely,

PRATT & WHITNEY AIRCRAFT GROUP

Connecticut Operations

W. R. Ironside

mb

UNITED

TECHNOLOGIES

210
ROLLWAy

Rodway Bearing Division 315-457-6211

P.Q Box 4827 Telex: 93-7265

• Syracuse. New York 13221

September 7, 1983

Arthur S. Irwin Co., Inc.

Driftwood

Bemus Point, N.Y. 13712

Attention: Mr. Arthur S. Irwin

Reference: Procurement and Rework Specifications

Dear Art:

We have reviewed the rework specification dated 5 August 1983 and the

procurement specification dated 10 August 1983 and consider them

adequate for defining the characteristics and controls necessary for

Army procurement of replacement bearings including those salvaged by

rework.

Very truly yours,

ROLLWAY BEARING

T. L. Morrissey

Manager

Engineering & Quality

TLM/rvg

DIVEION CDF LIPE-ROLLWAY CORPORATION

211
Split Ballbearing

DIVISION OF MPB CORPORATION

HIGHWAY FOUR. LEBANON. NEW HAMPSHIRE 03786

TELEPHONE: 603-448-3000

TWX: 710-366-1661

November 3, 1983

Arthur S. Irwin Co., Inc.

Technology Consultants

Driftwood

Bemus Point, NY 14712

Attention: Mr. Arthur S. Irwin, President

ASICO Program Manager

Subject: Specification for Ball § Cylindrical Roller Bearings

Rework, Refurbishment and Restoration

Dear Mr. Irwin:

We have reviewed the subject specification and would note that we are

primarily interested in the "Rework, Refurbishment and Restoration"

portion at this time.

With the addition of the quality audit in Paragraph 3.1 (of both

specifications) as an option in lieu of qualification testing, we

feel that the documents are now in a form that will be workable at

Split Ballbearing.

Yours truly,

Wm. J. Roos

Supervisor, Advance

Product Development

WJR/bt

cc: ALP

212
TRWBEARINGS DIVISION

June 6, 1983

Mr. Arthur S. Irwin, President

ASICO, Inc.

Driftwood

Bemus Point, New York 14712

Dear Mr. Irwin:

SUBJECT: 1. Specification for ball and cylindrical roller bearings

2. Rework, Refurbishment and Restoration of Aircraft

Engine and Power Transmission cylindrical and ball

bearings

In the opinion of TRW Bearings Division, the subject documents can

serve the purpose of standardization of requirements for new aircraft

bearings and for overhaul of used bearings, providing that changes

are made consistent with comments presented at the Coordination meeting on June 1 & 2, 1983.

Very truly yours,

Dan Lundquist

Manager, Aircraft Engineering

/nmt

BEARINGS DIVISION OF TRW INC.

402 CHANDLER STREET JAMESTOWN, NEW YORK 14701

TELEPHONE (716) 661-2600 TELEX 91527 BEARINGS

213
BEARINGS DIVISION

September 15, 1983

Mr. Arthur S. Irwin

Driftwood

Bemus Point, N.Y. 14712

Subject: Specification for Ball and Roller Bearings

Rework, Refurbishment and Restoration

Ref: ASICO Letter 8/24/83

Dear Mr. Irwin:

The following comment applies to paragraph 8.1.17 of the proposed ball

and roller bearing specification.

8.1.17 currently reads, "rolling element minimum clearance from the

tang or retention device as in the operating condition, where applicable."

Proposed rewording is: "minimum clearance between rolling element and

cage,to be measured with rolling element and cage positioned in a simulated operating position to produce the closest approach between rolling

element and the cage retention feature."

The following comment applies to paragraph 10.5 of the refurbishment

specification. To the best of our knowledge there is no statistical test

evidence to suggest the existance of a finite endurance life for aircraft

bearings. We submit that there should be no limit imposed on the number

of times that a bearing could be refurbished. On the other hand, bearings should not be restored (re-ground) more than once since the use of

oversized rolling elements will destroy the design relationships necessary

for proper bearing functioning.

The following comment applies to paragraph 8 of the general ball and

roller bearing specification. MIL-STD-880 is not listed as a current

specification in the official register of government standards.

Very truly yours,

Dan Lundquist

Manager Aircraft Engineering

DL/fmr

cc: J.K. Bailey

C.H. Morse

BEARINGS DIVISION OF TRW INC.

4O2 CHANDLER STREET JAMESTOWN, NEW YORK 147O1

TELEPHONE (716) 661-2600 TELEX 91527 BEARINGS

214
APPENDIX E

TYPICAL DRAWINGS WITH DATA FORMATS

"U.S.Government Printing Office: 1985 — 559-109/10436

215
ORIGINAL PAG6 »

OF POOR

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OF

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THESE FACES FLOSHWVTHIM.OOoeN

ec BALL-S MUST BE RETAILED IN RETAINER WHEN REMOVED PROM RACES

2S SPECIAL HEAT TREAT REQUIRED TO INCLUDE DETAILS OF

MICROSTRUCTURE AND RETAINED AUSTENITE REQUIREMENTS PER.^E

iA INNER RING HIGH POIWT OF ECCENTRICITY TO BE IDENTIFIED

£3 N ITAL ETCH STAINS TO BE REMOVED

2E VENDOR SUBSTANTIATIOM REQUIRED

cTI fc> VENDOR IDENTIFICATION REQUIREMEATTS

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» RETAINER FACE TO BEARING FACE CLEARANCE

18 LOBING , WAVINESs.i CHATTER TOLERANCES

OF BEARING BORE & O.D.

H PILOT RING LOCATING DIAM. CONCENTRICITY

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IS PITCH DIAMETER

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13 BEARING MATERIALS STABILIZED TO OPERATE AT -CJ5TO+8OO F.

IS SURFACE

ROUGHNESS (AA)

RING PILOT SURFACE

RETAINER POCKET

RETAINER PILOT SURFACE

BEARING O.D.

BEARING BORE

[INNER RACE

II RETAINER

(DIMENSIONS &

ENGINEERING

REQUIREMENTS ARE

AFTER PLATING)

IO ROLLING ELEMENT

RING MATERIAL

OUTER RACE

ROLLING. ELEMENT

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HARDNESS

PLATING SPECIFICATION

PLATING THICKNESS

TYPE OF RETENTION

HARDNESS Rc

SPECIFICATION

9 ROLLING ELEMENT TO RETAINER POCKET CL'RANCE.

fi RETAINER BORE TO O.D. CONCENTRICITY

7 RETAINER WIDTH, MAX.

(. RETAINER PILOT CLEARANCE , DIAMETRAL

5 RADIAL CLEARANCE UNDER II LB.GAGE LOAD

4 NUMBER OF ROLLING ELEMENTS PER ROW

3 SIZE OF ROLLING ELEMENTS

2--/S.FBMA CLASS

M

MACHII4«OC.O-C.A

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I THIS BEARIN& MUST CONFORM TO THE PREMIUM

AIRCRAFT QUALITY REQUIREMENTS OF <&. SPEC:

M50TF3 C

L

BLEND SMOOTH

WITH BORE.

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3

Z.401C.

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t END PLAY UNDER UL&&AGE LOAD

& CONTACT ANGLE UNDER 22LB.&AGE LOAD

5 SHIM THICKNESS FOR SPLIT RIMGS

A MAX. jTCP AT SPLIT (SPLIT RINGS)

3 SHIM ANGLE

£ RACE GROOVE DEPTH %

OF BALL DIAMETER

1 RACE GROOVE CURVATURE %

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6 ROLLER TO FLANGE/END CLEARANCE

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BEARING,BALL.ANNULAR

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FOLDOUT FRAME

PAGE BLANK NOT FILMED

FRAMg
APPLICATION NUMBER

NEXT ASS'Y DRWG NO.

OPERATING SPECTRUM :

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LUBRICAMT- OIL -IN

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RACE DEPTHS ••(•/. BALL OIA.)

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CAC,E WEIGHT, LBS.

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NO. OF ROLLING ELEMENTS

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MIL STANDARD | MIL-L-1806

T^-UURlCANT IS NONSTAND THE

IS REQUIRED

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DENSITY

'THERMS-CONDUCTIVITY'

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NOTES:

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BEARING EALL ANNULAR N^

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LOAD -AXIAL. UBS

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OUTER RACE & ADJACENT MATIWG PACES

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LU&RICANT DATA:

MIL. STAK1DARD TM IL-L-76O6

FOLLO

RlCANT 15 NON-STAND THE

TA IS REQUIRED

PRESSURE. VlSCeSJTY®lOO

PRESSURE VISCOSITY

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THE RINGS WITHOUT CUTTING. OR BENDING. TANGS.

THE ROLLING ELEMENTS SMALL BE- RETAINED IN

THE RETAINER BY A "SWAP-IN" CONFIGURATION.

Z. ROLLING ELEMENTS SHALL BE. MARdER THAN THE

RINGS BY ONE OR TWO POINTS, ROCKWE.LL *C*.

(IF SPE.CIFIE.D)

HOLDOUT FRAME

FQLBOUT FRAME

BEARING

DATE: \\-<V'B3

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6,038T48 5HE6.T Z

DRAWING NUMBER
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23 NITAL ETCH STAINS TO BE REMOVED

K VENDOR SUBSTANTIATION REQUIRED

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SPEC.

2ORETA.INER FACES TO BE PARALLEL WITHIM 6~OTAUl .OO2.

It RETAINER FACE TO BEARING FACE CLEARANCE

18 LOSING .WAVINESS.i CHATTER TOLERANCES

OF BEARING BORE & O.D.

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7 RETAINER WIDTH, MAX.

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4 NUMBER OP ROLLING ELEMEMTS

3 SIZE OF ROLLING ELEMENTS

AFBMA CLASS (RBEC)

.001-

.ooz.

C.O-C.4

.002.

14

THIS BEARIN& MUST CONFORM TO THE PREMIUM

AIRCRAFT QUALITY REQUIREMENTS OF &E SPECS:

M&OTFS c\-.- A (MAhjuc,1! a.e>ec CLOSS s fl so

.OI»R

E PLACES

•ADJACENT SIDES OF EACH

POCKET MUST BE

PERPENDCULAR WITHIN .OOI

-CROSS WEB MUST BE

PERPENDICULAR TO

SIDES WITHIN .OOI5

L.CW3REF

THIS EDGE OF TAN i TO BE

PARALLEL TO AXIS JF BRG.

WITHIN 5* AFTER f JNDING

.O3O-.O4OR.

BLEWD

8 RUNOUTXJF SPLIT RING CONTACT FACE WITH

RESPECT TtXBpRE. OF SPLIT RIMG

GRAIN ORIENTATION TO BE SUBSTANTIALLY

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1 END PLAV

G, CONTACT ANGLE LENDER

t>AGE LOAD ^S

5 SHIM THICKNESS

4 '••:••-• .-.TCI- AT SPLIT

3 SHIM ANGLE

Z RACE

OF BALL lAMETE-R

I RACH"GROOV£ CURVATURE. %

BALL DIAMETER

OUTER

INNER

.O4O R. MAX.

TO CLEvM* .O5O R.

4 PLACES

.010-.080

Z PLACES

Z PLACES

.006

MIM.

.OIO R

^-BREAK ALL TAB EDGES .OIO-.OZO

£.511

i.SOT

33 WITH RETAINER A&AINST OLfTER RACE SHOULDER «ROLLER

AGAINST OUTER RACE iRETAINER BRIDGE SECT.^A MIN.CLRANCt

- OF.OO3TOBE MAINTAINED RETWEEN ROLLER * I'.r. TANG

19 ROLLER POCKET l-OCATE.D IN RETAINED WfTHIN

DlA. OFTR'JE PO&iTIOM

IS ROLLER COMPLiWENT TO BE RETAIUilD

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IT MIN.CLRANCe-ROLLERTORETAINER RK.TEfTTiON

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is END FLOAT

(4 ROLLER LENGTH i DIAMETER VARiATlOKI RiR BRG.

II CAGE UMBANCe AT SOO R.P.M.

IZ ROLLER END FACE FIKJ1SW

I ROLLER CORNER RADIUS

10 FLANGE: LAYBACK ANGLE

<3 FLANGE WEIGHT

8 ROLLER TO FLANGE END CLEARANCE

ROLLER CORNER RADIUS RUMOUT WITH

RESPECT TO ROLLER CYLINDRICAL SECTION

6. ROLLER END SQUARENESS

S ROLLE1R FLAT CENTRAL!

ROLLER FuAT LENGTH

3 ROLLER CROWN DROP

ROLLER CROWN RADIUS

I ROLLE.R ROUNDNESS

MKRWAJ'-E

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.0018

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£•> IKJ.

BEARING

.„„ ~H-

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FRAME FQLPOUTFRMSS
APPLICATION NUMBER

NEXT ASS'Y DWG. NO.

OPERATING SPECTRUM :

FLIGHT CONDITION

2

V"

1

% TIME

BEARIN3 SPEED , RPM

LOAD -AXIAL

RADIAL, UBS.

TEMPERATURES (°F) '.

INNER RACE & ADJACENT MATING FACES

OUTER RACE & ADJACENT MATING FACES

ROLLING ELEMENTS

OIL- OUT

BEARING RADIAL CL'RANCE AT OPERATING TEMP.

1

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80

^40

£30

£48

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BASIC BEARING DATA

BEARING RADIAL CL RANCE AT ROOM TEMPERATURE

PITCH DIAMETER

' ROLLER DIAMETER

ROLLER LENGTH

NO. OF ROLLINS ELEMENTS

ROLLER SPHERICAL RADUS(ENDj

ROLLEP CROWM RADIUS _j

ROLLER FLAT LENGTH

OUTER RACEWAV EFFECTIVE LENGTH ("AXIAL )

INNE-R RACEWAY EFFECTIVE LENGTH OxiAL)

OUTER RACEWAY CROWN RADIUS

INNER RACEWAY CROWN RADIUS

OUTER RACEWAY FLANGE ANGLE

OUTER RING FLANGE TO ROLLER END PLAY

SURFACE ROUGHNESS

OUTER RACEWAY

INNER RACEWAY

ROLLERS

ROLLER ENDS

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CAGE :

TYPE

RAIL LAND DIAMETER

SINGLE RAIL WIDTH

RAIL TO LAND DIAME^P/-- CLEAPAMCF.

CAGE POCKET CLEARANCE ^AV !A'._ C'^nns)

CAGE WEIGHT (LBS. 'i

LOB ING :

HEIGHT

NUMBER

LOAD ORIENTATION

.OOI£

a.iSLo

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14

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.393

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8

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LUBRICANT DATA :

MIL - STANDARD [MTUTT16O6~

NOTES -. ,

I. WHEJRE PRACTICAL, RETAINED SHALL 6E DESIGNED

TO PERM IT REMOVAL OF ROLLING ELEMEUTS FROM

THE RiNGS WITHOUT CUTTING OR BEMD'.NG TANGS.

THE ROLJ_\WG ELEM&MTB SWALL. BE RE.TA.INED BY

A "SNAP-H-J " CONFIGURATiOL.

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DATE: U -\0-5j

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SHEETS

DflAWINO NUMBER

•POST 18AB-1ST - 18 « 24
WTTH THRUST INDIRECTION

SHOWN $ END PLAY REMOVED

UNDER MLB.GASE LOAD THESE

PACES TO BE FLUSH WITHIN

JXOS 4 CROSS CORNER DIMENSION

MET

FCUPOUT

K

WHEN BALLACAGE COMPLEMENT ARE REMOVED FROM RACES,

BALLS 70 BE RETAINED IN RETAINER

SPECIAL HEAT TREAT REQUIRED TO INCLUDE DETAILS OF

MICROSTRUCTURE AND RETAILED AUSTENITE REQUIREMENTS .PER. Gp SPEC.

INNER RING HIGH POINT OF ECCE.NTR IClTY TO BE IDENTIFIED

NITAL ETCH STAINS TO BE RE.MOVED

VENDOR SUBSTANTIATION REQUIRED

b> VENDOR IDENTIFICATION REQUIREMS.KJTS

2ORETA.INER FACES TO BE PARALLEL WITHIM (TOTAL) ,OO£

fl RETAINER FACE TO BEARING FACE CLEARANCE

18 LOSING , WAVINESS, 4 CHATTER TOLERANCES

OF 8EARIWG BORE & O.O.

II PILOT RING LOCATING OlAM. CONCENTRIClTV

IG> RETAINER LAND WIDTH

IS PITCH DIAMETER

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.005

.001

.103

£.464

15 BEARING, MATERIALS 5TABILIZEOTO OPERATE AT-GSTC.*8OO* F.

SURFACE

ROUGHNESS (AA)

RING PILOT SURFACE.

RETAINER POCKETRETAINER

BEARING O.D.

BEARING BORE

iINNER RACE

ROLLING ELEME.NT

II RETAINER

(DIMENSIONS &

ENGINEERING

REQUIREMENTS ARE

AFTER PLATING)

OUTER RACE

MATERIAL SPECIFICATION

HARDNESS Rc

PLATING SPECIFICATION

PLATING THICKNESS

TYPE OF RETENTION

IO ROLLING ELEMENT

RING MATERIAL

HARDNESS Rt

SPECIFICATION G>

9 ROUJNG ELEMENT TO RETAINER POCKET CL'RANCE

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^ RETAINER WIDTH,

(. RETAINER PILOT CLEARANCE, , DIAMETRAL.

5 RADIAL, CLEARANCE UNDER It L-B.'GAGE LOAD

4 NUMBER OF ROLLING ELEMENTS

3 SIZE OP ROLLING ELE.MENT5

CLASS

\z

30-35

AMS

£4 IE

TAN6

6.0-C.4

.171

TUIS BEARING MUST CONFORM TO THE PREMIUM

AIRCRAFT QUALITY REQUIREMENTS oF.c^e SPEC.

M50TF5 CL-ft (&6AI2lMC,&) &5EX O.-5

>3 ROLLER POCKET i-OCATEO I

NjlA. OF TRUE PO&mOW

I&, ROLLER DROP(RpLLER CEMTEREDIN RETAINER

15 END FLOAT\ /

14 ROLLER LENQT\4 DIAMETER VARIATIQK1 PER BRG.

IbCAGE (JM6ANCE A^T R.P.M. /

\Z. BALL POCKET LOCATED IN RET. ,DIA OF TRUE POS.TION

ii CAGE UNBALANCE: AT SOORPM (NO ALTERATIONS)

IO INNER RING O.Q RUNOUT WHEN BORE IS U^ED AS REF.

1 RING GRAIN ORIENTATION TO BE SUBSTAN

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.OO (.

3&M-CM.

.OOI

TIALLY

SPEC.

& RUNOUT OF SPLIT RING CONTACT FACE WITH

RESPECT TO BORE. OF SPLIT RING

1 END PLAV UNDER II Li. &AGE LOAD MAX.

&, CONTACT ANGLE UNDER £i LB&AGE LOAD

5 SHIM THICKNESS FOR SPLIT RINGS

4 MAX. STEP AT SPLIT (SPLIT RINGS)

3 SHIM ANGLE

£ RACE GROOVE DEPTH %

OF BALL DIAMETER

1 RACE GROOVE. CURVATURE %

OF BALL DIAMETER

OUTER

INNER

OUTER

INNER

.0001

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IZ ROLLER END FACE F1KIISH

I I ROLLER CORNER

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9 FUANGE HEIGHT

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APPLICATION NUMBER

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°/0TlME

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LOAD - AXIAL , L.BS .

RADIAL, LBS.

TEMPERATURES •-

INNER RACE & ADJACENT MATING FACES

OUTER RACE & ADJACENT MATING PACE-b

ROLUIUG ELEMENTS

LUBRICAMT - OIL-IKI

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" CAGE POCKE.T DETAIL DIMENSIONS \

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___ AXIAL

RADIAL HEIGHT, MlN.

CAGE GUIDING LAND CONTACT EFFECTiVIE

~ PILOT DIAMETRAL CLEARANCE

CAGE WIDTH

BASIC BEARING DATA '

BEARING RADIAL CL'RAKICE AT ROOM TEMPERATURE

RIK1GS

CAGE TYPE

CAGE LAND RlDlKiG

PITCH DIAMETER

NO. OF' ROLLING ELEMENTS

Bf LI. DIAMETER

CONTACT ANGi_E

OU'TER RACE ^yRyATURE

INNER RACE' CURVATUPE

•...URPACE

OUTER RACE

i\ ;NER RACE

CALL

10° £4

.004

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.095

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p.R.R.

".52.

4-

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2.

LUBRICANT DATA:

MIL L Mn--\--~ie>oe>

bRiCANT is NON-bTANDTHE

IS REQUIRED

PRESSURE VT

"PRESSURE VISCOSITY

NOTEb

I. WHERE PRACTICAL., RETAINER SHALL. BE DESIGNED

TO PE.RMIT REMOVAU OF ROLLING E.I_EME.NTt> FROM

THE RIM&S WITHOUT CUTTING OR BENDIMG. TANGf,.

THE ROLLING ELEMENTS SHALL BE. RETAINED IN

THE RETAINER BY A "SMAP-IN " COM FIGURATION.

E.ROLLING. ELEMENTS SHALL BE WARDER THAK1 TME

RIN&S BY ONE OR TWO POINTS, ROCKWEE.LL "C".

(IF SPECIFIED)

FODOUTFRAJUg

BEARING

APPROVED BV

BEARING|EALL1ANNULAR N^

BO34T2.5

ORAWINO NUUB£R

T 1BAB 1ST- 18i 24
1. Report NO. NASA CR. 174710

USAAVSCOM-TR-85-F-l

2. Government Accession No. 3. Recipient's Catalog No.

4. Title and Subtitle

Review and Critical Analysis - Rolling-Element

Bearings for System Life and Reliability

5. Report Date

March 1985

6. Performing Organization Code

7. Authors) "

Arthur S. Irwin, William J. Anderson,

and Willia m J. Derner

8. Performing Organization Report No.

None

10. Work Unit No.

9. Performing Organization Name and Address

Arthur S. Irwin Co., Inc.

Driftwood Center

Bemus Point, New York 14712

11. Contract or Grant No.

NAS 3-23520

12. Sponsoring Agency Name and Address

NASA Lewis Research Center, Cleveland, Ohio 44135,

and U.S. Army Aviation Systems Command,

St. Louis, Missouri

13. Type of Report and Period Covered

Contractor Report

14. Sponsoring Agency Code

505-33-7C

15. Supplementary Notes

Final report. Project Managers, Erwin V. Zaretsky, Structures Division, NASA

Lewis Research Center, Cleveland, Ohio 44135, and Martin Joseph, U.S. Army

Aviation Systems Command, St. Louis, Missouri.

16. Abstract

A ball and cylindrical roller bearing technical specificationjtfhich incorporates

the latest state-of-the-art advancements was prepared with the fullest cooperation and participation of a broad industry committee for the purpose of improving bearing reliability in U.S. Army aircraft. An examination of current U.S.

Army aviation bearing designs and applications, including life analyses, was made

in preparing the specification. A bearing restoration and refurbishment specification was also prepared, with the goal of improving bearing availability.

17. Key Words (Suggested by Author(s))

Rolling-element bearings; Bearing

specification; Bearing manufacture and

procurement; Bearing refurbishment and

restoration

18. Distribution Statement

Unclassified - unlimited

STAR Category 37

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of pages

233

22. Price'

All

*For sale by the National Technical Information Service, Springfield, Virginia 22161
National Aeronautics and

Space Administration

Lewis Research Center

Cleveland. Ohio 44135

Official Business

Penalty for Private Use $300

SECOND CLASS MAIL

ADDRESS CORRECTION REQUESTED

S.MAIL

Postage and Fees Paid

National Aeronautics and

Space Administration

NASA-451

NASA