Technical Information

Hydraulic Brakes
BK, AB, FB, SB, RP Serieswww.danfoss.com

Technical Information
Hydraulic Brakes

Revision history

2 | © Danfoss | June 2019

Table of revisions
Date

ChangedRev

June 2019

Spelling and grammatical updates

0103

Nov 2017

Updated SB 930 max. release pressure rating

0102

Mar 2017

First edition

0101

BC00000383en-000103

Technical Information
Hydraulic Brakes
Contents
Technical Information
Operating Recommendations..................................................................................................................................................... 4
Oil Type........................................................................................................................................................................................... 4
Fluid Viscosity and Filtration................................................................................................................................................... 4
Installation and Start-up...........................................................................................................................................................4
Hydraulic Motor Safety Precaution.......................................................................................................................................4
Hydraulic Brake Precaution..................................................................................................................................................... 4
Allowable Bearing and Shaft Loading.......................................................................................................................................5
Vehicle Drive Calculations.............................................................................................................................................................6
Induced Side Load............................................................................................................................................................................9
Hydraulic Equations...................................................................................................................................................................... 10
Shaft Nut Information...................................................................................................................................................................11
BK 913 and 915 Series
BK 913 and 915 Series Housings...............................................................................................................................................14
BK 913 and 915 Series Technical Information......................................................................................................................14
BK 913 and 915 Series Shafts..................................................................................................................................................... 16
BK 913 and 915 Series Ordering Information...................................................................................................................... 16
AB 920 Series
AB 920 Series Housings................................................................................................................................................................17
AB 920 Series Technical Information...................................................................................................................................... 18
AB 920 Series Shafts...................................................................................................................................................................... 19
AB 920 Series Ordering Information....................................................................................................................................... 19
FB 925 Series
FB 925 Series Housings................................................................................................................................................................ 20
FB 925 Series Technical Information....................................................................................................................................... 21
FB 925 Series Shafts.......................................................................................................................................................................22
FB 925 Series Ordering Information........................................................................................................................................ 22
SB 930 Series
SB 930 Series Housings................................................................................................................................................................ 24
SB 930 Series Shafts.......................................................................................................................................................................25
SB 930 Series Technical Information....................................................................................................................................... 26
SB 930 Series Installation Information....................................................................................................................................26
SB 930 Series Ordering Information........................................................................................................................................27
RP 960 Series
RP 960 Series Ordering Information........................................................................................................................................29© Danfoss | June 2019

BC00000383en-000103 | 3

Technical Information
Hydraulic Brakes
Technical Information

Operating Recommendations
Oil Type
Hydraulic oils with anti-wear, anti-foam and demulsifiers are recommended for systems incorporating
Danfoss motors. Straight oils can be used but may require VI (viscosity index) improvers depending on
the operating temperature range of the system. Other water based and environmentally friendly oils may
be used, but service life of the motor and other components in the system may be significantly
shortened. Before using any type of fluid, consult the fluid requirements for all components in the systemfor compatibility. Testing under actual operating conditions is the only way to determine if acceptable
service life will be achieved.
Fluid Viscosity and Filtration
Fluids with a viscosity between 20 - 43 cSt [100 - 200 S.U.S.] at operating temperature is recommended.
Fluid temperature should also be maintained below 85°C [180° F]. It is also suggested that the type ofpump and its operating specifications be taken into account when choosing a fluid for the system. Fluidswith high viscosity can cause cavitation at the inlet side of the pump. Systems that operate over a wide
range of temperatures may require viscosity improvers to provide acceptable fluid performance.
Danfoss recommends maintaining an oil cleanliness level of ISO 17-14 or better.
Installation and Start-up
When installing a Danfoss motor it is important that the mounting flange of the motor makes full contact
with the mounting surface of the application. Mounting hardware of the appropriate grade and size must
be used. Hubs, pulleys, sprockets and couplings must be properly aligned to avoid inducing excessive
thrust or radial loads. Although the output device must fit the shaft snug, a hammer should never beused to install any type of output device onto the shaft. The port plugs should only be removed from the
motor when the system connections are ready to be made. To avoid contamination, remove all matterfrom around the ports of the motor and the threads of the fittings. Once all system connections are
made, it is recommended that the motor be run-in for 15-30 minutes at no load and half speed to remove
air from the hydraulic system.
Hydraulic Motor Safety Precaution
A hydraulic motor must not be used to hold a suspended load. Due to the necessary internal tolerances,
all hydraulic motors will experience some degree of creep when a load induced torque is applied to a
motor at rest. All applications that require a load to be held must use some form of mechanical brakedesigned for that purpose.
Hydraulic Brake Precaution

C Caution
Danfoss’ brakes are intended to operate as static or parking brakes. System circuitry must be designed tobring the load to a stop before applying the brake.
To achieve proper brake release operation, it is necessary to bleed out any trapped air and fill brakerelease cavity and hoses before all connections are tightened. To facilitate this operation, all motor/
brakes feature two release ports. One or both of these ports may be used to release the brake in the unit.
Motor/brakes should be configured so that the release ports are near the top of the unit in the installed
position.
Once all system connections are made, one release port must be opened to atmosphere and the brakerelease line carefully charged with fluid until all air is removed from the line and motor/brake releasecavity. When this has been accomplished the port plug or secondary release line must be reinstalled. In
the event of a pump or battery failure, an external pressure source may be connected to the brake releaseport to release the brake, allowing the machine to be moved.
4 | © Danfoss | June 2019

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Technical Information
Hydraulic Brakes
Technical Information
Allowable Bearing and Shaft LoadingThis catalog provides curves showing allowable radial loads at points along the longitudinal axis of the
motor. They are dimensioned from the mounting flange. Two capacity curves for the shaft and bearings
are shown. A vertical line through the centerline of the load drawn to intersect the x-axis intersects thecurves at the load capacity of the shaft and of the bearing.
In the example below, the maximum radial load bearing rating is between the internal roller bearings
illustrated with a solid line. The allowable shaft rating is shown with a dotted line.
The bearing curves for each model are based on laboratory analysis and testing conducted at Danfoss.
The shaft loading is based on a 3:1 safety factor and 330 Kpsi tensile strength. The allowable load is thelower of the curves at a given point. For instance, one inch in front of the mounting flange the bearing
capacity is lower than the shaft capacity. In this case, the bearing is the limiting load. The motor userneeds to determine which series of motor to use based on their application knowledge.
ISO 281 Ratings vs. Manufacturer's Ratings
Published bearing curves can come from more than one type of analysis. The ISO 281 bearing rating is aninternational standard for the dynamic load rating of roller bearings. The rating is for a set load at a speedof 33 1/3 RPM for 500 hours (1 million revolutions). The standard was established to allow consistentcomparisons of similar bearings between manufacturers. The ISO 281 bearing ratings are based solely on
the physical characteristics of the bearings, removing any manufacturers specific safety factors or
empirical data that influences the ratings.
Manufacturers’ ratings are adjusted by diverse and systematic laboratory investigations, checked
constantly with feedback from practical experience. Factors taken into account that affect bearing life arematerial, lubrication, cleanliness of the lubrication, speed, temperature, magnitude of the load and thebearing type.
The operating life of a bearing is the actual life achieved by the bearing and can be significantly different
from the calculated life. Comparison with similar applications is the most accurate method for bearing life
estimations.
-100

-75

-50

-25

0

25

50

75

100

mm

9000

4000

8000

3500
445 daN [1000 lb]

7000

3000

6000

445 daN [1000 lb]
2500

5000
2000
4000
1500

3000
SHAFT

1000

2000
BEARING

1000
lb

-100

-75

-50

-25

0

25

50

500
daN

75

100

mm
P109320© Danfoss | June 2019

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Technical Information
Hydraulic Brakes
Technical Information
Example Load Rating for Mechanically Retained Needle Roller Bearings
Bearing Life L10(C/P)p [106 revolutions]

L10

nominal rating lifeC

dynamic load ratingP

equivalent dynamic load

Life Exponent p

10/3 for needle bearings

Bearing Load Multiplication Factor Table
RPM

Factor

50

1.23

100

1.00

200

0.81

300

0.72

400

0.66

500

0.62

600

0.58

700

0.56

800

0.50

Vehicle Drive Calculations
When selecting a wheel drive motor for a mobile vehicle, a number of factors concerning the vehicle
must be taken into consideration to determine the required maximum motor RPM, the maximum torquerequired and the maximum load each motor must support. The following sections contain the necessary
equations to determine this criteria. An example is provided to illustrate the process.
Sample application (vehicle design criteria)
vehicle description

4 wheel vehicle

vehicle drive

2 wheel drive

GVW

1,500 lbs.

weight over each drive wheel

425 lbs.

rolling radius of tires

16 in.

desired acceleration

0-5 mph in 10 sec.

top speed

5 mph

gradability

20%

worst working surface

poor asphalt

To determine maximum motor speed
RPM = (2.65 x KPH x G) / rm or RPM = (168 x MPH x G) / ri

6 | © Danfoss | June 2019

KPH

max. vehicle speed (kilometers/hr)

MPHmax. vehicle speed (miles/hr)

BC00000383en-000103

Technical Information
Hydraulic Brakes
Technical Information
G

gear reduction ratio (if none, G = 1)rmrolling radius of tire (meters)rirolling radius of tire (inches)

RPM = (168 x 5 x 1) / 16 = 52.5
To determine maximum torque requirement of motor
To choose a motor(s) capable of producing enough torque to propel the vehicle, it is necessary to
determine the Total Tractive Effort (TE) requirement for the vehicle. To determine the total tractive effort,
the following equation must be used:
TE = RR + GR + FA + DP (lbs or N)
TE

Total tractive effort

RR

Force necessary to overcome rolling resistanceGR

Force required to climb a gradeFA

Force required to accelerate

DP

Drawbar pull required

The components for this equation may be determined using the following steps.
Step One: Determine Rolling Resistance
Rolling Resistance (RR) is the force necessary to propel a vehicle over a particular surface. It is
recommended that the worst possible surface type to be encountered by the vehicle be factored into theequation.
RR = (GVW / 1000) x R (lb or N)
GVW

gross (loaded) vehicle weight (lb or kg)

Rsurface friction (value from Rolling Resistance on page 7)

Rolling Resistance© Danfoss | June 2019

Concrete (excellent)

10

Concrete (good)

15

Concrete (poor)

20

Asphalt (good)

12

Asphalt (fair)

17

Asphalt (poor)

22

Macadam (good)

15

Macadam (fair)

22

Macadam (poor)

37

Cobbles (ordinary)55

Cobbles (poor)

37

Snow (2 inch)

25

Snow (4 inch)

37

Dirt (smooth)

25

Dirt (sandy)

37

Mud

37 to 150

BC00000383en-000103 | 7

Technical Information
Hydraulic Brakes
Technical Information
Rolling Resistance (continued)
Sand (soft)

60 to 150

Sand (dune)

160 to 300

Step Two: Determine Grade Resistance
Grade Resistance (GR) is the amount of force necessary to move a vehicle up a hill or “grade.” This
calculation must be made using the maximum grade the vehicle will be expected to climb in normal
operation.
To convert incline degrees to % Grade:% Grade = [tan of angle (degrees)] x 100
GR = (% Grade / 100) x GVW (lb or N)
Example: GR = (20 / 100) x 1500 lbs = 300 lbs
Step Three: Determine Acceleration ForceAcceleration Force (FA) is the force necessary to accelerate from a stop to maximum speed in a desiredtime.
FA = (KPH x GVW (N)) / (35.32 x t) or FA = (MPH x GVW (lb)) / (22 x t)ttime to maximum speed (seconds)

Example: FA = (5 x 1500 lbs) / (22 x 10) = 34 lbs
Step Four: Determine Drawbar Pull
Drawbar Pull (DP) is the additional force, if any, the vehicle will be required to generate if it is to be used
to tow other equipment. If additional towing capacity is required for the equipment, repeat steps one
through three for the towable equipment and sum the totals to determine DP.
Step Five: Determine Total Tractive Effort
The Tractive Effort (TE) is the sum of the forces calculated in steps one through three above. On low
speed vehicles, wind resistance can typically be neglected. However, friction in drive components may
warrant the addition of 10% to the total tractive effort to insure acceptable vehicle performance.
TE = RR + GR + FA + DP (lb or N)
Example: TE = 33 + 300 + 34 + 0 (lbs) = 367 lbs
Step Six: Determine Motor Torque
The Motor Torque (T) required per motor is the Total Tractive Effort divided by the number of motors
used on the machine. Gear reduction is also factored into account in this equation.
T = (TE x rm) / (M x G) Nm per motor or T = (TE x ri) / (M x G) lb-in per motorM

number of driving motors

Example: T = (367 x 16) / (2 x 1) lb-in/motor = 2936 lb-in
Step Seven: Determine Wheel Slip
To verify that the vehicle will perform as designed in regards to tractive effort and acceleration, it isnecessary to calculate wheel slip (TS) for the vehicle. In special cases, wheel slip may actually be desirable
to prevent hydraulic system overheating and component breakage should the vehicle become stalled.
TS = (W x f x rm) / G (Nm per motor) or TS = (W x f x ri) / G (lb-in per motor)
8 | © Danfoss | June 2019

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Technical Information
Hydraulic Brakes
Technical Informationfcoefficient of friction (see Coefficient of friction (f) on page 9)Wloaded vehicle weight over driven wheel (lb or N)

Example: TS = (425 x .06 x 16) / 1 = lb-in/motor = 4080 lbs
Coefficient of friction (f)Steel on steel

0.3

Rubber tire on dirt

0.5

Rubber tire on a hard surface

0.6 - 0.8

Rubber tire on cement

0.7

To determine radial load capacity requirement of motor
When a motor used to drive a vehicle has the wheel or hub attached directly to the motor shaft, it iscritical that the radial load capabilities of the motor are sufficient to support the vehicle. After calculating
the Total Radial Load (RL) acting on the motors, the result must be compared to the bearing/shaft load
charts for the chosen motor to determine if the motor will provide acceptable load capacity and life.
RL = sqrt(W2 + (T / ri)2) lb or RL = sqrt(W2 + (T / rm)2) kg
Example: RL = sqrt(4252 + (2936 / 16)2) = 463 lbs
Once the maximum motor RPM, maximum torque requirement, and the maximum load each motor must
support have been determined, these figures may then be compared to the motor performance charts
and to the bearing load curves to choose a series and displacement to fulfill the motor requirements forthe application.
Induced Side LoadIn many cases, pulleys or sprockets may be used to transmit the torque produced by the motor. Use of
these components will create a torque induced side load on the motor shaft and bearings. It is importantthat this load be taken into consideration when choosing a motor with sufficient bearing and shaft
capacity for the application.

Radius 76 mm [3.00 in]

Torque1129 Nm[10000 lb-in]

P109321© Danfoss | June 2019

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Technical Information
Hydraulic Brakes
Technical Information
To determine the side load, the motor torque and pulley or sprocket radius must be known. Side load
may be calculated using the formula below. The distance from the pulley/sprocket centerline to themounting flange of the motor must also be determined. These two figures may then be compared to thebearing and shaft load curve of the desired motor to determine if the side load falls within acceptableload ranges.
Distance

TorqueSide Load = RadiusSide Load = 14855 Nm [3333 lbs]

P109322

Hydraulic Equations
Multiplication Factor

Abbreviation

1012

T

tera

109

G

giga

106

M

mega

103

K

kilo

102

h

hecto

101

da

deka

10-1

d

deci

10-2

c

centi

Theo. Speed (RPM)

Prefix(1000 x LPM) / Displacement (cm3/rev)(231 x GPM) / Displacement (in3/rev)

Theo. Torque (lb-in)(Bar x Disp. (cm3/rev)) / 20 pi(PSI x Disp. (in3/rev) / 6.28

Power In (HP)(Bar x LPM) / 600(PSI x GPM) / 1714

Power Out (HP)

10 | © Danfoss | June 2019

(Torque (Nm) x RPM) / 9543

BC00000383en-000103

Technical Information
Hydraulic Brakes
Technical Information(Torque (lb-in) x RPM) / 63024

Shaft Nut Information
The tightening torques listed with each nut should only be used as a guideline. Hubs may require higher
or lower tightening torque depending on the material. Consult the hub manufacturer to obtainrecommended tightening torque. To maximize torque transfer from the shaft to the hub, and tominimize the potential for shaft breakage, a hub with sufficient thickness must fully engage the taper
length of the shaft.
Hub engagement

Incorrect

Correct
P109323© Danfoss | June 2019

BC00000383en-000103 | 11

Technical Information
Hydraulic Brakes
Technical Information
35MM TAPERED SHAFTS
M24 x 1.5 ThreadA

Slotted Nut
6 [.24]6 [.22]

42 [1.64]

15 [.59]

36 [1.42]
Torque Specifications:32.5 daNm [240 ft.lb.]

1” TAPERED SHAFTS
3/4-28 ThreadA

Slotted Nut

B

Lock NutC
23 [.92]

6 [.24]

Solid Nut

16 [.63]

5 [.19]33 [1.29]

33 [1.29]

12 [.48]

28 [1.12]
Torque Specifications:

20 - 23 daNm [150 - 170 ft.lb.]

24 [.95]

33 [1.28]

3.5 [.14]

29 [1.13]
Torque Specifications:

28 [1.10]

24 - 27 daNm [180 - 200 ft.lb.]

12 [.47]

28 [1.11]
Torque Specifications:

20 - 23 daNm [150 - 170 ft.lb.]

1-1/4” TAPERED SHAFTS
1-20 ThreadA

Slotted Nut

B

Lock Nut

6 [.25]C

Solid Nut

16 [.63]

29 [1.14]

5 [.19]40 [1.57]

44 [1.73]

14 [.55]

38 [1.48]
Torque Specifications:

38 daNm [280 ft.lb.] Max.

30 [1.18]

44 [1.73]

4 [.16]35 [1.38]
Torque Specifications:

34 [1.34]

33 - 42 daNm [240 - 310 ft.lb.]

14 [.55]

38 [1.48]
Torque Specifications:

38 daNm [280 ft.lb.] Max.

1-3/8” & 1-1/2” TAPERED SHAFTS
1 1/8-18 ThreadA

Slotted Nut

B

Lock NutC
35 [1.38]

6 [.22]

Solid Nut

16 [.63]

5 [.19]51 [2.00]

48 [1.90]

15 [.61]42 [1.66]
Torque Specifications:41 - 54 daNm [300 - 400 ft.lb.]

44 [1.73]
Torque Specifications:

36 [1.42]

44 [1.73]

4 [.16]34 - 48 daNm [250 - 350 ft.lb.]

48 [1.90]

42 [1.66]
Torque Specifications:

15 [.61]
41 - 54 daNm [300 - 400 ft.lb.]
P109324

12 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes
BK 913 and 915 Series

Overview
With safety an increasingly important factor in the design and manufacture of equipment, it has become
necessary to add a brake to many critical machine functions. In response to that concern, Danfoss offers
BK Series brakes. Based on technology proven in Danfoss integrated motor/brakes, this spring-applied,hydraulically released brake provides up to 1500 Nm [13,300 lb-in] of holding torque for static brakeapplications.
Other features contribute to the superior operation and durability of the BK brakes. All internal
components, including roller bearings, brake disks, springs and seals were chosen for maximum
durability. To further extend the life of the unit and reduce noise, all internal components run in an oilbath. Two brake release ports are also provided to simplify plumbing and bleeding of the brake releasecircuit during installation. All of these features combine to make BK Series brakes a top choice for any
static brake application requiring up to 1500 Nm [13,300 lb-in] of holding torque.
Features / Benefits•••

Heavy-duty roller bearings support high shaft loads and provide long life.
Dual release ports allow easier bleeding of brake release cavity.
Oil-filled cavity immerses all components providing quiet operation and reduced wear.

Typical Applications
Wheel drives, positioners, conveyors, door openers, swing drives, aerial work platforms and more

P109449

Specifications© Danfoss | June 2019913 Series Holding Torque1130 Nm [10,000 lb-in]

915 Series Holding Torque1500 Nm [13,300 lb-in]

Release Pressure

28 bar [400 psi]

Maximum Release Pressure

207 bar [3,000 psi]

Release Volume

11.5 cm3 [0.7 in3]

Max. Speed

250 rpm

Max. Operating Temperature

82 °C [180 °F]

Weight16.8 kg [37 lb]

Fluid Type

Mineral based oil

BC00000383en-000103 | 13

Technical Information
Hydraulic Brakes
BK 913 and 915 Series
BK 913 and 915 Series Housings
Dimensions shown are without paint. Paint thickness can be up to 0.13 [.005].
4-Hole, Brake Mount, Aligned Ports
4-HOLE, BRAKE MOUNT, ALIGNED PORTS

K30

7/16-20 UNF(4) Ø 13 [.52]

59 [2.34]

14.2 [.558]
11.3 [.443]

50 [1.95](2) SAE J51 4b
7/16-20 Release Ports,
Min. Depth 11 [.45]

25 [1.00]

7/16-20 Fill HolePort Plug Installed

101.6 [3.999]
101.5 [3.997]

Ø 200 [7.88]

Ø 178 [7.00]

90°

13 [.50]913 Series - 107 [4.21]
915 Series - 117 [4.61]

P109450

BK 913 and 915 Series Technical Information

Allowable Shaft Load / Bearing Curve
The bearing curve represents allowable bearing loads based on ISO 281 bearing capacity for an L10 life of
2,000 hours at 100 rpm. Radial loads for speeds other than 100 rpm may be calculated using the Bearing
Load Multiplication Factor Table on page 6.

14 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes
BK 913 and 915 Series
BK 913 Series Brake - Side Load Chart
913 SERIES BRAKE - SIDE LOAD CHART
9000

0

25

50

75

100

125

150

175

200

225 mm445 daN [1000 lb]

8000
7000

4000

3500

445 daN [1000 lb]

3000

6000
2500
5000

SHAFT

2000

4000
1500

3000

1000

2000
BEARING

500

1000
lb

0

1

2

3

4

5

6

7

8

9

in

daN

P109451

BK 915 Series Brake - Side Load Chart
915 SERIES BRAKE - SIDE LOAD CHART
9000

0

25

50

75

100

125

150

175

200

225 mm445 daN [1000 lb]

8000
7000

4000

3500

445 daN [1000 lb]

3000

6000
2500
5000

SHAFT
2000

4000
1500

3000

1000

2000
BEARING

500

1000
lb

0

1

2

3

4

5

6

7

8

9

in

daN

P109452© Danfoss | June 2019

BC00000383en-000103 | 15

Technical Information
Hydraulic Brakes
BK 913 and 915 Series
BK 913 and 915 Series Shafts
31

1-1/2” Tapered
913 Series - 176 [6.92]
915 Series - 185 [7.29]

8.0 [.314]
8.0 [.313]

19 [.75]

45 [1.78]

5 [.20]31.8 [1.250]
30.5 [1.200]

38.1 [1.499]
38.0 [1.498]
4 [.15]
Ø4 [.17]

1:8 Taper
A slotted hex nut is standard on thisshaft.
P109453

Max. Torque: 2700 Nm [19900 lb-in]

BK 913 and 915 Series Ordering Information

12

1. CHOOSE SERIES DESIGNATION

3

4

5

5. SELECT A PAINT OPTION

67913 Hydraulic Brake

A

Black

915 Hydraulic BrakeZ

No Paint

2. SELECT A HOLDING TORQUE OPTION

6. SELECT A VALVE CAVITY / CARTRIDGE OPTION

000 Standard

A

3. SELECT A MOUNT & PORT OPTION

7. SELECT AN ADD-ON OPTION

K30 4-Hole, Brake Mount, Aligned Ports, 7/16-20 UNF

AStandard

4. SELECT A SHAFT OPTIONC

Solid Hex Nut

31

8. SELECT A MISCELLANEOUS OPTION

1-1/2” Tapered

8

None

AA None16 | © Danfoss | June 2019

P109454BC00000383en-000103

Technical Information
Hydraulic Brakes
AB 920 Series

Overview
The AB series is a multi-wet-disc-brake that provides superior performance; all internal components are
fully immersed in pre-filled fluid and are environmentally sealed to prevent contamination and corrosion
while providing brake durability and maintaining proper holding capacity. Compact design and large
holding torque along with a lower release pressure and lower free turn torque saves your space andreduces cost. Two brake release ports provide simple plumbing and the bleeding of the brake releasecircuit during installation.
Features / Benefits

•
•
•
•
•

Compact design.
Ball bearings support higher shaft loads and provide longer life shaft seal life.
Dual release ports allow easier bleeding of brake release cavity.
Oil-filled cavity immerses all components providing quiet operation.
Large holding torque with lower release pressure and free turn torque.

Typical Applications
Wheel drives, positioners, conveyors, door openers, swing drives, aerial work platforms and more

P109449

Specifications
Holding Torque475 Nm [4,200 lb-in]

Release Pressure

20 bar [290 psi]

Maximum Release Pressure

207 bar [3,000 psi]

Release Volume

9.0 cm3 [0.55 in3]

Max. Speed

250 rpm

Max. Operating Temperature

82 °C [180 °F]

Weight9.25 kg [20.4 lb]

Fluid Type

Mineral based oil

AB 920 Series Housings
Dimensions shown are without paint. Paint thickness can be up to 0.13 [.005].

© Danfoss | June 2019

BC00000383en-000103 | 17

Technical Information
Hydraulic Brakes
AB 920 Series
4-Hole, Brake Mount
4-HOLE, BRAKE MOUNT

K30

7/16-20 UNF

82.41 [3.244]
81.39 [3.204]
47 [1.85] Max.

30°

30°

Ø149.35 [5.880]
Ø149.10 [5.870](2) 1/8-28 Fill Port30°

Ø110 [4.33]
Max.

Ø95.28 [3.750]
Ø95.12 [3.746]

Ø178 [6.99]

Ø82 [3.23]
Max.

30°

30°

(2) 7/16-20 UNF Release Port,
Min. Depth 12 [.45]Ø13.7 [.539]
Ø13.5 [.532]
P109456

AB 920 Series Technical Information

Allowable Shaft Load / Bearing Curve
The bearing curve represents allowable bearing loads based on ISO 281 bearing capacity for an L10 life of
2,000 hours at 100 rpm. Radial loads for speeds other than 100 rpm may be calculated using the Bearing
Load Multiplication Factor Table on page 6.
AB 920 Series Brake - Side Load Chart
920 SERIES BRAKE - SIDE LOAD CHART
2800

0

25

50

75

100

125

150

175

200

225 mm1200

111 daN [250 lb]

2400

1000
111 daN [250 lb]

2000

800
1600
600
1200
BEARING

800

400

200

400

lb

0

1

2

3

4

5

6

7

8

9

in

daN

P109457

18 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes
AB 920 Series
AB 920 Series Shafts
13

22

1” Tapered
35.18 [1.384]
34.68 [1.366]

6.35 [.250]
6.30 [.248]

90.47 [3.562]
87.43 [3.442]
7.95 [.313]
7.93 [.312]

19 [.75]

31.70 [1.248]
31.38 [1.235]

4.7 [.185]

31.75 [1.250]
31.70 [1.248]

3.30 [.130]
3.09 [.121]

Ø3.96 [.156]

31.70 [1.248]
31.38 [1.235]

4.7 [.185]

Ø25.425 [1.001]
Ø25.375 [.999]

Ø4.42 [.174]

Taper 1:8

3/4-16 UNF Slotted Hex Nut

88.64 [3.489]
85.59 [3.369]

35.15 [1.383]
34.65 [1.365]

19 [.75]

2.65 [.108]
2.63 [.100]

1-1/4” Tapered

Taper 1:8

1-20 UNEF Slotted Hex Nut

P109458

AB 920 Series Ordering Information

12

1. CHOOSE SERIES DESIGNATION

3

4

5

5. SELECT A PAINT OPTION

67920 Hydraulic Brake

A

Black

2. SELECT A HOLDING TORQUE OPTION

B

Black, Unpainted Mounting Surface

000 475 Nm [4200 lb-in]

6. SELECT A VALVE CAVITY / CARTRIDGE OPTION

3. SELECT A MOUNT & PORT OPTIONA

K30 4-Hole, Brake Mount, 7/16-20 UNF

7. SELECT AN ADD-ON OPTION

4. SELECT A SHAFT OPTIONA

131” Tapered

8. SELECT A MISCELLANEOUS OPTION

22

1-1/4” Tapered

AA 1.50 [.060] Pilot Height (Standard)
AY

8

None

Standard

3.18 [.125] Pilot Height

AZ 6.35 [.250] Pilot Height
TC Single Throttle Valve With Standard Pilot Height
TD Two Throttle Valves With Standard Pilot Height© Danfoss | June 2019

P109459

BC00000383en-000103 | 19

Technical Information
Hydraulic Brakes
FB 925 Series

Overview
The FB series is a multi-wet-disc-brake that provides superior performance; all internal components are
fully im- mersed in pre-filled fluid and are environmentally sealed to prevent contamination andcorrosion while providing brake durability and maintaining proper holding capacity. Compact design andlarge holding torque along with a lower release pressure and lower free turn torque saves your space andreduces cost.
Features / Benefits

•
•
•
•

Compact design.
Heavy-duty roller bearings support higher shaft loads and provide longer life shaft seal life.
Oil-filled cavity immerses all components providing quiet operation.
Large holding torque with lower release pressure and free turn torque.

Typical Applications
Wheel drives, positioners, conveyors, door openers, swing drives, aerial work platforms and more

P109460

Specifications
Release Pressure

20 bar [290 psi]

Maximum Release Pressure

207 bar [3,000 psi]

Release Volume

9.0 cm3 [0.55 in3]

Max. Speed

250 rpm

Max. Operating Temperature

82 °C [180 °F]

Weight10.9 kg [24 lb]

Fluid Type

Mineral based oil

FB 925 Series Housings
Dimensions shown are without paint. Paint thickness can be up to 0.13 [.005].

20 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes
FB 925 Series
4-Hole, Brake Mount
4-HOLE, BRAKE MOUNT

K30

85.1 [3.350]
84.7 [3.334]

7/16-20 UNF

10.4 [.409]
8.6 [.339]

15°

1/8-28 Fill Port

7/16-20 UNF Release Port,
Min. Depth 11.5 [.45]Ø159 [6.26]

Ø110 [4.33]
Max.

Ø114.25 [4.498]
Ø114.20 [4.496]

87.3 [3.44]
86.7 [3.42]
Ø186 [7.32] Max.

Ø13.8 [.540]
Ø13.2 [.520]
45°

47 [1.85] Max.

P109461

FB 925 Series Technical Information

Allowable Shaft Load / Bearing Curve
The bearing curve represents allowable bearing loads based on ISO 281 bearing capacity for an L10 life of
2,000 hours at 100 rpm. Radial loads for speeds other than 100 rpm may be calculated using the Bearing
Load Multiplication Factor Table on page 6.
FB 925 Series Brake - Side Load Chart
925 SERIES BRAKE - SIDE LOAD CHART
9000

0

25

50

75

100

125

150

175

200

225 mm111 daN [250 lb]

8000
7000

4000

3500

111 daN [250 lb]

3000

6000

2500

5000
2000
4000
1500

3000

1000

BEARING

2000

500

1000
lb

0

1

2

3

4

5

6

7

8

9

in

daN

P109462© Danfoss | June 2019

BC00000383en-000103 | 21

Technical Information
Hydraulic Brakes
FB 925 Series
FB 925 Series Shafts
31

D7

1-1/2” Tapered

32mm Tapered

150.50 [5.925]
148.78 [5.857]

144.50 [5.689]
142.75 [5.621]

42.25 [1.663]
41.75 [1.644]
7.95 [.313]
7.93 [.312]

21 [.83]

31.70 [1.248]
31.38 [1.235]

5.5 [.217]

36.25 [1.427]
35.75 [1.408]

7.95 [.313]
7.93 [.312]

21 [.83]

31.70 [1.248]
31.38 [1.235]

5.5 [.217]

Ø38.10 [1.500]
Ø38.05 [1.498]

32.00 [1.260]
31.95 [1.258]

3.30 [.130]
3.09 [.122]

3.30 [.130]
3.09 [.122]
Taper 1:8
Ø4.4 [.173]

Taper 1:8

Ø4.4 [.173]

1-20 UNEF Slotted Hex Nut

1-1/8-18 UNEF Slotted Hex Nut

P109463

FB 925 Series Ordering Information

12

1. CHOOSE SERIES DESIGNATION

3

4

5

5. SELECT A PAINT OPTION

67925 Hydraulic Brake

A

Black

2. SELECT A HOLDING TORQUE OPTION

B

Black, Unpainted Mounting Surface

350 350 Nm [3100 lb-in]

6. SELECT A VALVE CAVITY / CARTRIDGE OPTION

550 550 Nm [4900 lb-in]A

650 650 Nm [5750 lb-in]

7. SELECT AN ADD-ON OPTION

3. SELECT A MOUNT & PORT OPTIONA

K30 4-Hole, Brake Mount, 7/16-20 UNF

8. SELECT A MISCELLANEOUS OPTION

4. SELECT A SHAFT OPTIONAA None

31

8

None

Standard

1-1/2” Tapered

D7 32mm Tapered

22 | © Danfoss | June 2019

P109464BC00000383en-000103

Technical Information
Hydraulic Brakes
SB 930 Series

Overview
The SB Series is a multiple-wet-disc-brake that provides superior performance in an extremely compact
package. Unlike conventional brakes offered today, the SB brake is performance-matched to fit the fullrange of small-frame SAE A mount motors available today. With an overall diameter of less than 137mm[5.4 in] the SB has a holding capacity in excess of 620 Nm [5,500 lb-in] and is easily mated to a variety of
global industry standard motor mounting and shaft options. In addition, the SB Series can be used as astand-alone brake solution without an input drive motor. This option further opens design flexibility tomeet a wider variety of application needs.
Features / Benefits

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

All wear components are fully immersed in fluid (wet multi-disc design)
Performance-matched to fit small-frame motors with SAE A mounts
Release pressure independent of motor pressure
Brake directly coupled to the output shaft
Wide-variety of input and output shaft options
Environmentally sealed / factory prefilled with oil
Proven, Quiet, Trouble-Free Operation
Compact, Cost-Effective Package
Simplifies System Circuits - Eliminates Need for Pressure- Reducing Valve
Series Operating Capability
Reliable Performance - Fewer Critical Components
Design Flexibility
Global Interchangeability
Suited for “Stand Alone” Brake Applications
Ease of Installation

Typical Applications
Wheel drives, positioners, conveyors, door openers, swing drives, aerial work platforms and more

P109465© Danfoss | June 2019

BC00000383en-000103 | 23

Technical Information
Hydraulic Brakes
SB 930 SeriesSpecifications
Code

225

315

415

520

620

Holding Torque

225 Nm [2,000 lb- 315 Nm [2,800 lb- 415 Nm [3,700 lb- 520 Nm [4,600 lb- 620 Nm [5,500 lbin]
in]
in]
in]
in]

Max. Release
Pressure

207 bar [3,000psi]

207 bar [3,000psi]

207 bar [3,000psi]

207 bar [3,000psi]

207 bar [3,000psi]

Full Release
Pressure

23 bar [330 psi]

23 bar [330 psi]

23 bar [330 psi]

36 bar [520 psi]

36 bar [520 psi]

Release Volume

8.3 cm3 [.51 in3]

8.3 cm3 [.51 in3]

8.3 cm3 [.51 in3]

8.3 cm3 [.51 in3]

8.3 cm3 [.51 in3]

Max. Speed

250 rpm

250 rpm

250 rpm

250 rpm

250 rpm

Unit Weight

8 kg [17.6 lb]

8 kg [17.6 lb]

8 kg [17.6 lb]

8 kg [17.6 lb]

8 kg [17.6 lb]

SB 930 Series Housings
Dimensions shown are without paint. Paint thickness can be up to 0.13 [.005].
2-HOLE, SAE A BRAKE MOUNT

A10

7/16-20 UNF A11

G 1/4

115.1 [4.53] Max.

95.3 [3.75]

A10 - 42.3 [1.67]
A11 - 41.6 [1.64]

6 [.24]
Brake Release Port

106.4 [4.19]
17°130.8 [5.15]
129.3 [5.09]

82.7 [3.255]
82.6 [3.253]

82.6 [3.250]
82.5 [3.248]

71.8 [2.83]*(4) Fill and Drain Ports

13.7 [.54]4-HOLE, SAE A BRAKE MOUNT

Brake Release PortA30

7/16-20 UNF A31
115.1 [4.53] Max.

17°

6 [.24](2) M12 x 1.75
Mounting Holes

9.5 [.374]

22.6 [.89]130.8 [5.15]
129.3 [5.09]

G 1/4

A30 - 42.3 [1.67]
A31 - 41.6 [1.64]

71.8 [2.83]

82.7 [3.255]
82.6 [3.253]

82.6 [3.250]
82.5 [3.248]

106.4 [4.19]
13.7 [.54]130.1 [5.12]*(4) Fill and Drain Ports
22.6 [.89]Cast Dimensions are ± 0.8 mm [.030 in.] *Fill and drain ports for filling and draining the brake only.
No system connections are to be made to the fill and drain ports. These ports are not suitable for use in a cooling loop.

24 | © Danfoss | June 2019

9.5 [.374]
130.8 [5.15]
129.3 [5.09](2) M12 x 1.75
Mounting Holes

P109466

BC00000383en-000103

Technical Information
Hydraulic Brakes
SB 930 Series
Cast Dimensions are ± 0.8 mm [.030 in.] *Fill and drain ports for filling and draining the brake only.
No system connections are to be made to the fill and drain ports. These ports are not suitable for use in acooling loop.

SB 930 Series Shafts
ZW

ZY

1” Straight, 6B Input

ZT

25mm Straight, 25mm Input

25mm Straight, 6B Input

52 [2.03]

52 [2.03]

43 [1.68]

43 [1.68]
6.4 [.251]
6.4 [.250]

25.9 [1.02]
24.6 [.970]

8.0 [.315]
8.0 [.313]

5 [.18]28.2 [1.110]
28.0 [1.101]

28.0 [1.102]
27.7 [1.091]

25.4 [.999]
25.4 [.998]

32mm Straight, 25mm Input

ZU

5 [.21]
Ø25.0 [.984]
Ø25.0 [.983]

M8 x 1.25, Min. Depth 18 [.70]5/16-18 UNC,
Min. Depth 18 [.70]ZX

30.9 [1.218]
29.7 [1.168]

32mm Straight, 6B Input

ZZ

6B Spline, 6B Input

67 [2.62]

52 [2.03]

56 [2.22]
10.0 [.394]
9.9 [.392]

34.8 [1.372]
34.5 [1.359]

43 [1.68]

32.6 [1.285]
31.4 [1.235]

6B Spline
SAE J499 Standard

12 [.46]

Ø25.3 [.996]
Ø25.2 [.992]

Ø32.0 [1.260]
Ø31.9 [1.259]
M8 x 1.25, Min. Depth 18 [.70]5/16-18 UNC,
Min. Depth 18 [.70]

6B INPUT DIMENSIONS

58.6 [2.3]

20 [.78] Min.

25MM INPUT DIMENSIONS
Mounting
SurfaceMounting
Surface26.6 [1.047]

6.3 [2.5]

Ø29.9 [1.177]

Ø 25.4 [1.00]

10.1 [.398]

58.6 [2.3]

26.6 [1.047]

Ø29.9 [1.177]

8.1 [.319]

28.4 [1.12]

Ø 25.1 [.99]10.1 [.398]

P109468© Danfoss | June 2019

BC00000383en-000103 | 25

Technical Information
Hydraulic Brakes
SB 930 Series
SB 930 Series Technical Information

Allowable Shaft Load / Bearing Curve
The bearing curve represents allowable bearing loads based on ISO 281 bearing capacity for an L10 life of
2,000 hours at 100 rpm. Radial loads for speeds other than 100 rpm may be calculated using the Bearing
Load Multiplication Factor Table on page 6.
SB 930 Series Brake - Side Load Chart
930 SERIES BRAKE - SIDE LOAD CHART
8000

-100

-75

-50

-25

0

25

50

75

mm
3500

7000

145 daN [320 lb]

6000

3000

145 daN [320 lb]

2500

5000
2000
4000
1500

3000

1000

2000

lb

500

BEARING

1000

-4

-3

-2

-1

0

1

2

3

in

daN

P109467

SB 930 Series Installation Information
The SB Brake is a wet multi-disc type static brake and is shipped factory filled with fluid. The fluid used is astandard SAE 20 hydraulic fluid. A hydraulic motor can be mounted to the SB Brake to provide a complete
motor/brake package. A shipping cover protects and seals the input interface until it is ready for
installation. The shipping cover is removed by removing the two cap screws and following the motor
installation procedure below. Mounting pilot surfaces need to be free of paint or other substances forproper assembly and leak-free performance. Standard SB brakes are sold unpainted with an easy toremove shipping cover. Stand-alone SB brakes come standard painted and factory installed cover.
The input interface must be sealed to keep the brake environmentally protected and bearings fully
immersed in fluid for proper lubrication and long life. Standard SAE 20 hydraulic oil is used in the brakecavity as well as typically used in hydraulic systems.
An internal seal is provided to seal long-pilot motors. When a short-pilot motor is used, an o-ring face sealis needed to properly seal the motor/brake interface. Two mounting bolts (M12 x 1.75 thread) and an oring seal with mounting instructions are included in the brake installation kit 930999001 and shippedwith each SB Brake.

26 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes
SB 930 Series
930 Series Brake Installation
930 SERIES BRAKE INSTALLATION
2.3 [.090]
2.1 [.084]
To remove cover, pierce andpry with a sharp awl.

Face Seal

When using the 930 Series as aStand-Alone unit, this cover is
not to be removed. It retains oil
needed to lubricate the bearings.

Factory Installed
Pilot Seal

2.54 [.100]
P109470

The factory installed pilot seal may be left in place. However, this seal will not provide proper sealing for motors withshort pilot mounts, therefore, the face seal contained in the mounting kit must be used.

The factory installed pilot seal may be left in place. However, this seal will not provide proper sealing for
motors with short pilot mounts, therefore, the face seal contained in the mounting kit must be used.
SB 930 Series Ordering Information

12

1. CHOOSE SERIES DESIGNATION

3

4

5

6

5. SELECT A PAINT OPTION

930 Hydraulic Brake

A

Black

2. SELECT A HOLDING TORQUE

B

Black, Unpainted Mounting Surface

Z

No Paint

225 225 Nm [2000 lb-in]

520 520 Nm [4600 lb-in]

315 315 Nm [2800 lb-in]

620 620 Nm [5500 lb-in]

7

6. SELECT A VALVE CAVITY / CARTRIDGE OPTION

415 415 Nm [3700 lb-in]A

3. SELECT A MOUNT & PORT OPTION

7. SELECT AN ADD-ON OPTION

A10 2-Hole, SAE A Brake Mount, 7/16-20 UNF

A

A11 2-Hole, SAE A Brake Mount, G 1/4

8. SELECT A MISCELLANEOUS OPTION

A30 4-Hole, SAE A Brake Mount, 7/16-20 UNF
A31 4-Hole, SAE A Brake Mount, G 1/4

8

None

Standard

AA Standard

4. SELECT A SHAFT OPTIONZT 25mm Straight, 6B Input

ZX 32mm Straight, 25mm Input

ZU 32mm Straight, 6B Input

ZY 25mm Straight, 25mm Input

ZW 1” Straight, 6B Input

ZZ 6B Spline, 6B Input© Danfoss | June 2019

P109469BC00000383en-000103 | 27

Technical Information
Hydraulic Brakes
RP 960 Series

Overview
The 960 Series is a device designed to replace existing, costly and complicated hydraulic brake releasehand pumps that are present on various types of mobile equipment. It is typically used to release various
types of spring applied/ hydraulically released brakes. Depending on the brake, typically 1-5 pumps of
the 960 will release the brake. This enables equipment to be moved to a service area or a recharge/refuelstation.
To operate, the equipment operator must depress the valve rod until it is firmly seated. The operator
must then pump the pump rod until the brakes are released. If the hydraulic circuit is pressurized at any
time during or after the 960 has released the brakes, the valve rod will automatically pop out and themobile equipment will revert to its normal operation. This serves as a built in safety feature that ensuresthe equipment’s normal braking operation is never accidentally disabled.
The 960 is a simplified product compared to competitive brands that are currently available. In addition,
the product is a cost competitve alterative that offers superior performance and design flexibility.
Specifications••

Typical output flow 1cm3 [.06 in3] - 2cm3 [.12 in3] per stroke depending upon oil viscosity, speed ofstroke, and pressure.
Maximum working pressure of 276 bar [4000 psi].

Schematic

LEFT BRAKE

B1

RIGHT BRAKE

P109471

28 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes
RP 960 Series
RP 960 Series Ordering Information

960020A10AAAAORDER CODES

960020A11AAAA

9 [.38]99 [3.90]

960020A12AAAA

41 [1.62]

26 [1.04]
StrokePump Rod45 [1.78]

24 [.95]

28 [1.10](2) 3/8-16 UNC
Through Mounting Holes
35 [1.38]
Valve Rod22 [.85]

9 [.36]76 [3.00]

9 [.27]25 [1.00]

The 960020A10AAAA has 7/16-20 UNF Ports. The 960020A11AAAA has #4 JIC fittings pre-installed. The 960020A12AAAA has G 1/4 Ports.

© Danfoss | June 2019

14 [.55]

P109472

BC00000383en-000103 | 29

Technical Information
Hydraulic Brakes

30 | © Danfoss | June 2019

BC00000383en-000103

Technical Information
Hydraulic Brakes© Danfoss | June 2019

BC00000383en-000103 | 31

Technical Information
Hydraulic Brakes

32 | © Danfoss | June 2019

BC00000383en-000103

Products we offer:

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

DCV directional control
valvesElectric converters
Electric machines
Electric motors

Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic andelectric components. We specialize in providing state-of-the-art technology and solutions
that excel in the harsh operating conditions of the mobile off-highway market as well as themarine sector. Building on our extensive applications expertise, we work closely with you toensure exceptional performance for a broad range of applications. We help you and othercustomers around the world speed up system development, reduce costs and bring vehicles
and vessels to market faster.

Hydrostatic pumps

Danfoss Power Solutions – your strongest partner in mobile hydraulics and mobile
electrification.

Orbital motors

Go to www.danfoss.com for further product information.

PLUS+1® controllers

We offer you expert worldwide support for ensuring the best possible solutions foroutstanding performance. And with an extensive network of Global Service Partners, we also
provide you with comprehensive global service for all of our components.

Hydrostatic motors

PLUS+1® displays
PLUS+1® joysticks andpedals
PLUS+1® operator
interfaces
PLUS+1® sensors
PLUS+1® software
PLUS+1® software services,support and training
Position controls andsensors
PVG proportional valves
Steering components andsystems
Telematics

Hydro-Gear
www.hydro-gear.com

Local address:

Daikin-Sauer-Danfoss
www.daikin-sauer-danfoss.com

Danfoss
Power Solutions (US) Company
2800 East 13th Street
Ames, IA 50010, USA
Phone: +1 515 239 6000

Danfoss
Power Solutions GmbH & Co. OHG
Krokamp 35
D-24539 Neumünster, Germany
Phone: +49 4321 871 0

Danfoss
Power Solutions ApS
Nordborgvej 81
DK-6430 Nordborg, Denmark
Phone: +45 7488 2222

Danfoss
Power Solutions Trading(Shanghai) Co., Ltd.
Building #22, No. 1000 Jin Hai Rd
Jin Qiao, Pudong New District
Shanghai, China 201206
Phone: +86 21 3418 5200

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order provided that such alterations can be made without subsequent changes being necessary in specifications already agreed.
All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.

© Danfoss | June 2019

BC00000383en-000103