Low-Friction Torque Bearing

LFT-Series

CAT.NO.B1023E-A

For the future of our planet environment

The Evolution of Rolling Bearings
The technology of “moving” and “rolling”

LFT-Series
Low-Friction Torquewith as little resistance as possible
has evolved since ancient times as an eternal theme,
blossomed as bearing technology and continued to evolve.

LFT-Series
JTEKT, since its time as Koyo Seiko, has constantly focused on friction and lubricationin efforts to reduce bearing torque and, in the 1980s, successfully developed theworld’s first low-torque tapered roller bearing, the LFT. New generations emerged as theproduct evolved - LFT-II, III and IV, and these have helped to improve the fuel efficiency ofautomobiles.
Currently, JTEKT applies low-torque technology to other bearing types such as ballbearings and hub units, and offers an extensive LFT bearing lineup.
JTEKT’s LFT-Series of low-torque bearings will continue evolving hereon into the future.
* LFT is an abbreviation for Low-Friction Torque and JTEKT’s registered trademark.

TRB-LFT

BB-LFT

HUB-LFTNRB-LFT

LubricantReduced agitating resistance◯◯◯◯

Reduced in viscous rollingresistance(Bearing ring-rolling element)

◯◯

◯

◯

Reduced sliding friction
resistance(Roller-inner ring rib)◯−−−

Reduced sliding friction
resistance(Roller-cage)−−−◯

Bearings are essential to all industries.
Therefore, reduction of energy loss (torque loss) in bearings through size / weight reduction,efficiency enhancement, etc. helps reduce CO2 emissions
across all industries and ultimately
contributes to the prevention of global warming,
which is a reflection of the ancient Japanese saying“Constant dripping wears away a stone”.

LFT-Series
incorporated technologies

SealReduced friction
resistance1◯2

Super-Low Friction Torque Tapered Roller Bearing (LFT-IV)

Low-Friction Torque Ball Bearing

TRB-LFT

BB-LFT

FeaturesFeatures

In order to optimally control the amount of lubricant that flows through the bearing, this bearing uses resin witha high degree of design freedom for its cage material and has reduced lubricant mixing resistance. Bearing life
in contaminated oil has also been improved- Horizontal deployment of structure used on super-low friction torque tapered roller bearing to control oil inflow- By optimizing cage and inner /outer ring shape, oil flow to bearing is restricted and mixing loss is reduced by up to30% compared to conventional angular contact ball bearings- Reduced amount of contaminants infiltrating the bearing and improved durability in contaminated oil by 1.5 times

Fast

Oil flow rate

Outer ring

Low pressure zone

<Mechanisms for reducing oil inflow>- Flow of lubricant in proximity of cage end face
separates from cage
- A low pressure zone is generated at lubricant
entry point, reducing flowCageFlow fromcage separates
Slow

Speed vector diagram

LFT-Ⅰ

LFT-Ⅱ

LFT-Ⅲ

LFT-Ⅳ

Double row low-friction torque ball bearing
for differential pinions

Structure of ultra-low torque tapered roller
bearing (LFT-IV) to control oil inflow

Single row low-friction torque ball bearing
for differential pinions

Major Fields of Application and Effects
Evolution of TRB-LFTFeatures
Friction torque reduction effect(compared to standard models)- Used on the pinion support of differential units to improve vehicle fuel efficiency byOptimization of shape androughness at contact portionof rib and roller

Special crowning of
inner / outer ring raceways

Controlled volume of oil
flow / Optimized internal

Optimal control of oil
inflow with a resin cage

-10％

-20％

-50％

-65％

Major Fields of Application and Effects- Used on the pinion support of differential units to improve vehicle fuel efficiency by

Next-generation high performance productDevelopedproductHigh performance
tapered roller bearing with resin cage
(improved anti-seizure)In addition to low-loss through high degree of design freedom usinga resin cage and longer life in contaminated oil (LFT-IV), this bearing
offers extended oil-free seizure time

3

2.5%

1%

Next-generation high performance product

Low-Friction Torque Deep Groove Ball Bearing
Supporting High Axial Loads- 10% smaller outer diameter than conventional deep groove ball bearings and improved
anti-axial load
- Compared to tapered roller bearings with equivalent load allowance (JTEKT’s LFT-II),torque loss reduced by up to 50%
1) Anti-axial load performance improved byincreasing depth of raceway groove on theside subjected to axial load

Resin cage

Groove inside pocket

Oil groove

Minimizes oil shortages and triples
oil-free seizure time2) Improved contaminant resistance / torquereduction by adopting a cage with oil flow
control

LubricantRetains lubricant ingroove and minimizes
oil shortages

Improved anti-seizure

Current productDeveloped product(standard deep groove ball bearing)4

Low-Friction Torque Hub Unit

Base Technology Supporting the LFT-Series

HUB-LFT

Mechanism analysis

Fluid analysis

Analysis of axle system
3000.03000.02000.01000.00.0Features

2000.01000.0
-9.70

-0.30

- Optimization of thickener, base oil and additive for hub operating environment, developed new grease achieving thetrade-off features of improved bearing life and reduced friction torque- Adopted a double axial lip seal achieving low-friction torque without adversely affecting sealing performance[ HUB Assembly torque ]1.2

50% less

Torque ratio

1
Double axial lip seal

0.30

9.70

Calculates precise torque by dynamic
analysis utilizing a program developed by
JTEKT and accounting for ball sliding
behavior

Analyzes lubricant flow, reduce agitating
resistance and reflects results in optimal
designInvestigates axis support rigidity, bearinglife, surface pressure, etc. for the overallunit then proposes optimal bearings

Visualization of oil flow

Measuring loss on an actual unit

Oil membrane measurement

Simulates lubricant flow under actual
operating conditions then proposes lowfriction torque bearings

Evaluation technology that enables accurate
detection of torque loss

Ensure required oil membrane by visualizing
oil-membrane state at time of low-friction
torque grease and poor lubrication

0.8
0.6
0.4
0.20Current productDeveloped productLow-friction torque grease

Major Fields of Application and Effects- Used on 4W of vehicles to improve vehicle fuel efficiency by0.5%

Actual vehicle evaluation technology

Low-Friction Torque Needle Roller Thrust Bearing

NRB-LFTFeatures- Reduced sliding resistance between roller end
face and cage by optimizing cage shape

Proving Ground Enables Testing / Evaluations Simulating Roads Worldwide

Cage

RollerFully utilizing our knowledge as a world-leading systems supplier, JTEKT conducts driving evaluations and analyses ofproducts installed in vehicles. We exhaustively pursue the highest standards in product safety and operation on a test
course capable of simulating various road and weather conditions of regions around the world. As a total systems
supplier, our highest value is to provide our customers with products that deliver outstanding performance and the best
quality that help to make automobiles that are more than just fun to drive.
ZY
Contact points between theroller end face and cage(roller center proximity-line contact)

Pocket end is convex

Cage pocket(View Z)

Cross-sectional view of pocket(View Y)

Major Fields of Application and Effects- Improved vehicle fuel efficiency through adoption on transmission unit
(independent friction torque reduction of 50 to 60% depending on conditions)5■ Iga Proving Ground・Site area: 500,000m2
・Course area: 170,000m2
・Combined circuit length: 2,200m
・Dynamics pad area: 54,000m2

・Straight-line track ・Winding track
・Fording track ・Dynamics pad
・Noise evaluation track

6

JTEKT Corporation WEB site
https://www.jtekt.co.jp/e/

JTEKT Bearing WEB site

JTEKT Overseas hubs

https://koyo.jtekt.co.jp/en/

https://www.jtekt.co.jp/e/company/global.html

The contents of this catalog are subject to change without prior notice. Every possible effort
has been made to ensure that the data herein is correct; however, JTEKT cannot assume
responsibility for any errors or omissions.

Reproduction of this catalog without
written consent is strictly prohibited.

CAT. NO. B1023E-A
17.10-15BCH