Product Introductions

Examples of Reciprocal Motion Applicationsof LFR SEALTM
1. Introduction

unique shape.
⑶ Improvement of pressure resistance

Since its development and launch as a low-torque seal

In order to prevent the seal from protruding intofor rotary applications, LFR SEALTM has been used

the gap between the axis and the seal, the shapemainly in the circular tables of machine tools, and hasof the seal is designed to prevent protrusion,

received a good reputation with our customers. Inthereby improving pressure resistance.

order to further expand the application of LFR⑷ Longer life

SEALTM, we have considered the application of LFR⑵ Low-torque and ⑶ improvement of pressure

SEALTM as a seal for reciprocating machinery. In thisresistance achieved longer life.

report, we introduce the results of evaluating LFR
by air pressure under reciprocating motion

test conditions.

⑸ Improvement in ease of installation
The seal has a double pressure seal shape with nospecific direction to prevent incorrect installation. By
making it a single structure of elastomer and resin

2. F eatures of the LFR SEALTM
low-torque seal for rotary applications

material, it has the equivalent ease of installation as
an O-ring.
installation as for O-rings.

2-1）Design concept

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The design concept of the LFR SEALTM is shown in⑴ - ⑸ . This concept solves the problem of conventionalrotary seals, which has been a challenge. Figure 1 shows
the structure of the LFR SEALTM. The base material isan elastomer with excellent elasticity, and the sliding

Figure1

Structure of LFR SEALTM

surface is covered with a low-friction resin material,
which is simultaneously molded into a single structure.

2-2）Comparison of rotational torqueThe specifications of LFR SEALTM and rotary torque

Design concept

comparison packing are shown in Table1. The packing is⑴ Small space

for axis diameter of φ30mm, and it was measured at a

In consideration of versatility, the seal mounting

rotational speed of 100 rpm and air pressure of 0 to 0.5

groove is the same as the groove dimensions of theMPa.

standard O-ring for motion（JIS B 2401 - 1 P series）.

The results of rotational torque measurement are shown

It is smaller in space than conventional slipper seals.

in Figure2. It can be confirmed that LFR SEALTM has⑵ Low - torque

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SEALTM

low-torque compared to O-rings and U - packings.

Low - torque was realized by placing a resinmaterial with a low coefficient of friction on thesliding surface with the axis, and by designing a24

Examples of Reciprocal Motion Applications of LFR SEALTM

Table1①

Table3Specifications of comparison packing

Comparison packing Cross-sectional
No.
（Model）
shape
LFR SEAL（LFR30）

Evaluation test conditions

Material

ItemConditions

NBR+PTFE with filler

Shaft diametar

φ30mmStroke

200mm

Speed

150mm/s

GasAirPressure

0.5MPaO-ring（P30）

NBR③U-packing（UPR30）

NBR④Σ-ring（Forφ30）

NBR+PTFE with filler⑤X-ring（R30）

NBR

MotionLubrication
condition

200mm stroke、4,500cycle
Apply grease to the packing and shaft.
For your reference：Amount of grease
10cc/packing per 1pc
Apply a thin layer of grease to the shaft.

Torque［N・m］②

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Pressure［MPa］

Figure2

Measurement results of rotational torque

3. Reciprocating motion test conditions

Schematics of the testing machine

The sliding of the axis is designed to reciprocate with a
servo cylinder（STP servo cylinder manufactured byand comparison

Horiuchi Machinery）. The groove size of each packing ispackings are shown in Table2. The packing was for axis

designed to match the groove size of each evaluation

diameter of φ30mm. The evaluation packings were thepacking.

The specifications of LFR SEAL

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Figure3TMsame type as the packings used in the rotational torquemeasurement in section 2 - 2）
. The evaluation test
conditions are shown in Table3, and the schematics ofthe testing machine is shown in Figure3.

4. Reciprocating motion
evaluation test results
The results of the characterization are shown in Table4.

Table2

Specifications of comparison packingpacking Cross-sectional
No. Comparison（Model）
shapeMaterial

The measurement results of leakage amount and sliding
resistance are shown in Figures4 and 5.
The amount of leakage of LFR SEALTM was small at①

LFR SEAL（LFR30）

NBR+PTFE with filler②O-ring（P30）

NBR

be used under reciprocating conditions. In addition, at③

U-packing（UPR30）

NBR

was larger than that of U - packing and other comparable

Σ-ring（Forφ30）

low air pressure, the sliding resistance of LFR SEALTM
products.

④（Composite packing ofO-ring and PTFE resin
processed product）

NBR+
PTFE with filler⑤X-ring（R30）

NBR

25

less than 0.05 cc / min, and it was confirmed that it could

Product Introductions

Table4No. Comparison
packing

5. Summary

Characterization results

Leakage(Standard leakage
Compared with3.4cc/min or less)

Sliding
exothermic
resistance Presence of temperature
stick-slip(Compare with［℃］※ 1U-packing)We believe that LFR SEALTM can be used as a seal for①

LFR SEALGoodLarge

None25℃

reciprocating motion without any sealing problems.

②O-ring

GoodLarge

None

25℃

However, since the design concept of LFR SEALTM is③U-packing

Good─

None

26℃

such that it can be used for hydraulic pressure at 14④

Σ-ring

GoodLarge

None

26℃

MPa without protrusion, the sliding resistance value may⑤

X-ring

GoodLarge

None

26℃

be large when used for air pressure applications.

※1

Ambient temperature of testing machine：23℃

6. Conclusion
In this report, we introduced the evaluation results ofLFR SEALTM under air pressure and reciprocating
conditions. We are also planning to do an evaluation test
under hydraulic pressure and reciprocating conditions.
In the future, we are planning to conduct evaluation
under high - pressure hydraulic environment, which is
LFR SEALTM’s specialty, and introduce examples of its

Figure4

Leakage measurement results

If you are interested in LFR SEALTM as a rotary seal,
reciprocating seal, or "rotary & reciprocating" seal, pleasecontact your nearest LFR SEALTM sales representative.

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use in reciprocating motion, so please look forward to it.

7. References
1）‌Akihiro Nagano: VALQUA Technical Journal, No.30,
9-13（2016）2）‌Low Friction Seal for VALQUA Rotation, Catalog,
LA08,（2017）
Figure5

Measurement results of sliding resistance※ LFR SEAL is a registered trademark of VALQUA Corporation.
※ Registered as a Japanese design.

Tetsuya Tokumaru
Research and Development Division
Research and Development Department

26No.40