Features and Configurations
The double-end support design and unique pin gear
mechanism provide the following advantages
- Capable of 5 times the rated torque
- High torsional rigidity
- Low backlash [1 arc.min]
- High torque density (capable of high torque with downsized gear)
- Capable of high reduction ratio (MAX I = 258:1)
A set of internal main bearings (large angular ball bearings)
enables complete support of heavy external loads.
- The hollow shaft structure that allows routing of cables through the reduction gear
- Pre-greased
- Coupling and motor flange provide easy motor mounting
Principle of Operation
Rotation of the servo motor is transmitted through the
input gear to the large center gear, and is then
transmitted through the small center gear to the spur
gear. At this point, the speed is reduced accordingly
to the gear ratio between the small center gear and
the spur gear. This operation is carried out in the First
reduction section.
Since they are directly connected, the crankshafts
have the same rotational speed as the spur gears.
Two RV gears are mounted around the needle
bearings on the eccentric region of the crankshaft. (In
order to balance the equal amount of force, two RV
gears are mounted).
When the crankshafts rotate, the two RV gears
mounted on the eccentric sections also revolve
eccentrically around the input axis (crank movement).
Pins are arrayed in a constant pitch in the grooves
inside the case. The number of pins is just one larger
than the number of RV teeth.
As the crankshafts revolve one complete rotation, the
RV gears revolve eccentrically one pitch of a pin
(crank movement), with all the RV teeth in contact
with all of the pins.
The rotation is then output to the shaft (output shaft) via
the crankshaft so that the crankshaft rotation speed can
be reduced in proportion to the number of pins.
The total reduction ratio is the product of the first reduction ratio multiplied by the second reduction ratio.
Model Code
Rating Table
| Model Code |  |
 |
 |
 |
 |
 |
|---|---|---|---|---|---|---|
| Ratio Code (Speed Ratio) | 081(81） | 100(99.82） | 109(109） | 101(100.5） | 106(105.83） | 115(115） |
| 108(108） | 142(141.68） | 153(152.6） | 150(150） | 156(155.96） | 157(157） | |
| 153(153） | 184(184） | 196(196.2） | 210(210） | 206(206.09） | 207(207） | |
| 189(189） | 233(233.45） | 240(239.8） | 258(258） | 245(245.08） | 253(253） | |
| 243(243） | ||||||
N-m(lb-in) |
98(868） | 265(2344） | 490(4340） | 980(8680） | 1960(17359） | 3136(27775） |
rpm |
15 | 15 | 15 | 15 | 15 | 15 |
Hr |
6000 | 6000 | 6000 | 6000 | 6000 | 6000 |
N-m(lb-in) |
245(2170） | 662(5859） | 1225(10850） | 2450(21699） | 4900(43398） | 7840(69437） |
N-m(lb-in) |
490(4340） | 1323(11718） | 2450(21699） | 4900(43398） | 9800(86796） | 15680(138874） |
rpm |
48 | 36 | 30 | 24 | 18 | 15 |
rpm |
80 | 60 | 50 | 40 | 30 | 25 |
Backlash arc.min |
1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
Lost Motion arc.min |
1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
Torsional R:G:dity N-m/arc.min (lb-in/arc.min) |
47(417） | 147(1302） | 255(2257） | 510(4513） | 980(8680） | 1960(17359） |
| Capacity of Main Bearing | ||||||
N-m(lb-in) |
686(6076） | 980(8680） | 1764(15623） | 2450(21699） | 8820(78117） | 20580(182272） |
N-m(lb-in) |
1372(12152） | 1960(17359） | 3528(31247） | 4900(43398） | 17640(156233） | 39200(347185） |
N(lb) |
5880(1323） | 8820(1984） | 11760(2646） | 13720(3087） | 19600(4409） | 29400(6614） |
mm |
91.2 | 112 | 136.8 | 148.9 | 204.4 | 245.9 |
Rated Torque
Rated Output Speed
Rated Life [Continuous]
Allowable Acceleration/
Momentary Maximum
Allowable Output Speed
Allowable Output Speed
Allowable Moment
Momentary Maximum
Maximum Thrust Load
Dimension α- 1. The rating table shows the specification values of each reduction gear.
- 2. The allowable output speed may be limited by heat depending on the operation rate.
- 3. For the moment of inertia of the reduction gear, refer to the external dimension drawings of the reduction gear and the coupling.
- 4. For dimension α, refer to "Allowable Moment And Maximum Axial Load".
