Traction Drive Unit

Reducer for high-accuracy feeding

Minimal rotation irregularity
No backlash
Low noise, low vibration

CAT.NO.B1011E-AA Traction Drive Unit
conceived from bearing core technologies

Ideal for High-accuracy Feeding

The traction drive unit is a power transmission based on the rolling contact between rollers and is capable of smooth,rattle-free power transfer. High-accuracy and high-strength rollers are subjected to elastic deformation prior toSpecification Examples

assembly, achieving high pressure force. Additionally, by introducing traction grease that becomes highly viscous underhigh pressure, it is possible to achieve excellent power transfer while securing lubricity.

No Backlash TypePrinciple and Structure

Double-row ball bearings

Bearing or bushing

①φ60
②φ67

Output side(planetary revolution )(sun shaft)

Reduction ratio i=DdD+dd

D:Stationary ring bore diameter
d:Sun shaft outer diameter
Reduction ratio: 3 - 12 (1-stage)
Large reduction ratio is possible
if made multistage

Planetary roller
Lubricant: Traction grease

MotorBushingµ:Traction coefficient
P:Pressure force

P

Input sideSun shaft

Min.35Traction force T=µP

P.C.D. 98
φ64

DrivenMotor①φ6②φ8Traction force T(rolling transfer force)

Highly-viscous lubricant

The compact design incorporates
a bushing in the planetary roller.

φ90P

Traction drive

φ8Drive

Compact Type

Backlash has been eliminated and friction reduced by adjusting
the internal clearance of the ball bearings in the planetary roller.

1560118

Reduction ratio

100 (2-stage reduction)
2N・mTorque (output shaft)

Reduction ratio

Rotating speed
fluctuation coefficient±0.5% or less

Backlash

0.01deg or lessStationary ring

Torque (output shaft)Rotating speed
fluctuation coefficient①②105

2〜4N・m

7.5〜12N・m±0.5％ or lessCustomization according to customer requests is available,
so please do not hesitate to contact us.

Application of JTEKT Core Technologies
Taking bearing technologies accumulated over many years
under the KOYO brand and applying them to traction drive units.
❶Materials, heat treatment technology❸High-precision machining technology❷Tribology technology❹Analysis technology❶High-strength material❶Optimal heat treatment❷Optimal contact
surface characteristics❸High-precision machining

Application Examples■Printers■Machine tools

Eliminate speed irregularity of feeding drum

■FPD manufacturing equipment

Contributes to improving image quality
Polygon motor■ROBOT❹Optimal surfacepressure calculation

And more
Polarization lensPrinted material
Laser generator❹EHL theoretical analysis❷Lubrication theoretical analysis(Highly viscous traction grease)

Traction drive

Rotation stability

No backlash

Low noise, low vibration

Feeding drumReducer with a Minimal Rotation Irregularity Unachievable Using Gears
FeaturesBacklash

2Rotation irregularity

BacklashNoise/Vibration

High-speed performance

Torque capacity

Traction drive◎◎◎○△

Planetary gear△△△△◎0.5

Output shaft load torque (N・m)

Mechanism

Backlash
0.25

0Clearance

Deflection-0.25

Measurement examples
Rotation irregularity
2%0%

-0.05

00.05

Output torsion angle (deg)

0.1

0.15

0.2

Electric micrometer
Torque sensor

Motor
Fixate the motor shaft

Traction drive (No Backlash Type)

Output shaft

0.2

0.3

0.4

0.5

80%

0.6

Time (s)Traction drive

2%1%

Rotating speed
fluctuation coefficient (%) =(Rotation irregularity)

0%Speed fluctuation
×100
Average rotating speed of output shaft

-1%

00.1

0.2

0.3
Time (s)0.4

Measurement method

0.5

Rotary encoder

2.0k

Planetary gear

52
50

Gear noise

1.5k

30

Motor noise

500

400

1k

1.5k

Frequency（Hz）

2k

20

2.5k

Traction drive

Gear noise
eliminated!

1440

1k

30

Motor noise

500

400

1k

1.5k

Frequency（Hz）

Vibration

0.6

Inertial load drum

Motor

Run the motor at a set speed measuring
rotating speed of the output shaft using
the rotary encoder
Plate spring coupling

Traction drive

Output shaft※Reduction ratio: 10, stepping motor drive
Motor operating speed: 100 rpm

15

Planetary gear
105

Traction drive
01000

2000

3000

4000

Rotating speed of sun shaft（min -1）

52
50

Gear noise
eliminated!

1.5k

40

1k

4

2.0k

Rotating speed（min -1）

0.1

Noise

3

sound pressure（dB）

0Reduced by

Rotating speed（min -1）

-1%

-2%

-0.1

Measure the torsion angle of the output shaft
when the motor shaft is fixed and torque isapplied to the output shaft clockwise
and counter-clockwise
Torque load

1%-2%

-0.15

Measurement method

Precision planetary gear

Vibration value（m/s 2）

Rotating speed fluctuation coefficient（%）

Rotating speed fluctuation coefficient（%）

1-0.5-0.2

No Backlash

Traction drive

Planetary gear

5000

sound pressure（dB）

Comparison with planetary gear

Vibration
reduced byapprox. 90%

2k20

2.5k14

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 possibleeffort 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.B1011E-A

Printed in japan '15.05-1CCH