Mitsubishi Heavy Industries Technical Review Vol. 49 No. 3 (September 2012)
47

Development of TSDB Series Planetary Traction Reducer
with Improved Reliability andTorque Transmission Performance

E n g i n e e r i n g D e pa r t m e n t
M a c h i n e To o l

The power transition principle of a planetary traction reducer is rolling contact, which allows
high rotational accuracy, non backlash and low noise, all of which are difficult to attain with
gear-type reducers. Planetary traction reducers are currently used in resin film/sheet productionlines and coating machines where a high rotational accuracy is required. In the midst of increasing
demand for highly functional film sheets, wider variations of materials, thinner film and larger andfaster production are under way, and the need for a new high-torque and highly accurate planetary
traction reducer is increasing. We have developed the TSDB series high-torque-type planetary
traction reducer to meet current needs. The features and applications of the product are introduced
below:|1. Specifications
The TSDB series has two sizes of 125 and 160.
Table 1 shows the main specifications.
Specifications of high-torque TSDB series

N

4.5
6.3
8
10

1800 1300 1950
1800 1650 2475
1800 1000 1500
1800 750 1125

960
960
430
430

12.5
20
30
40
50

1800
1800
1800
1800
1800

600
1300
1650
1650
1500

900
1950
2475
2475
2250

0
620
620
620
270

63
90
125
250
320

1800
1800
1800
1800
1800

1500
1300
1650
1650
1650

2250
2250
2475
2475
2475

270
230
230
230
100

500

1800 1500 2250

100

1

2

3

6800

6800

6800

610

756

768

Nm

Nm

N

N

2600
3300
2000
1500

3900 1200
4950 1200
3000 530 11000 758
2250 530

1200
2600
3300
3300
3300

1800
3900
4950
4950
4950

0960
960
960 11000 913
430

3300
2600
3300
3300
3300

4950
3900
4950
4950
4950

430
370
370
370 11000 992
1603300 4950

160

Back lashOutput shaft

N

Angular velocity
fluctuation rate

Input shaft

Nm

Total length

Momentary
Max.

Nm

Output shaft

Rated

min-1

Input shaft

Input shaft speed-CommonMomentary
Max.

Nominal reduction
ratio

Stage

TSDB160
Output shaft Allowable
torqueradial load
Rated

Reduction stage type

TSDB125
Output shaft Allowable
torqueradial load

Total length

Table 1% or Sec orless less

0.07

120.18100.4

10

Mitsubishi Heavy Industries Technical Review Vol. 49 No. 3 (September 2012)
48|2. Features
2.1

A Problem in the Existing Model

Planetary traction reducers require high-pressure contact among rollers to avoid slips
between the internal cylindrical rollers, and for that, contacting pressure is given using elastic
deformation on the internal roller. This method allows the contacting pressure to be easily set andfacilitates ease of assembly and disassembly.
However, reducers have sometimes caused the machine to stop with the sudden destructionof the internal rollers when slight slips occur with momentary overloading, etc., as the inner surfaceof the internal rollers are always under tensile stress.

2.2

Improvement(1)

The affect on the reducer on the occasion of momentary overload, etc., was reduced as aresult of a review of the shape of the internal components. (Improvement of reliability)
With the change of the internal roller shape and loading mechanism to apply contactpressure to the internal rollers, the propagation of cracks is delayed even when a slight slip isgenerated. In addition, long-term stable production is ensured.
(2) Torque increased by 120 – 200% compared with existing series reducers
To allow larger and thinner film sheet production, the optimization of contact pressure
was conducted for each reduction ratio, and increased torque was obtained. This allows areduction of the planetary roller reducer size, which tends to be larger than gear-type reducers.
(3) Can replace existing series
The total length, shaft center height and installation bolt positions on the legs are thesame as those of the conventional series in consideration of existing series reducer replacement.
When the required torque is the same as that of a conventional reducer, the shaft diameter isunchanged to allow trouble-free replacement.
(4) Addition of non backlash specification
A non backlash specification, which was not available in the existing high-torque series,
has been realized with the reconsideration of internal structure to allow the production of higher
quality film and sheets.
(5) Wider reduction ratio
The 6 existing high-torque versions (13 standard versions) have been increased to 15versions.

|3. Future Development
The 160 and 125 size introduced in this paper are high-torque specifications mainly targetingthe film and sheet industries. We are happy to respond to other customer specifications including
outside diameter, total length, shape and torque. For example, a small reducer of φ60 in diameterand 2 Nm output torque has been supplied. We would like to share the concept and features ofplanetary traction reducers with domestic and overseas customers, and proceed with thedevelopment and design of new products.