Planetary Gearheads  
  Spur Gearheads  




V Series (IG-13V, 16V and 22V) planetary gearheads offer higher torque thanks to optimum design and are of simple construction realized by sintered components. R Series (IG-16R and 22R) planetary gearheads have very small backlash thanks to highly precise machining and assembly.
Higher torque transmittable.
81% per stage
Input-output position:
Same center
Input/output rotating direction:






Centered around RB-35 Series, the world standard, selection can be made from a wide range of products according to applications such as size and torque.
RB-35V Series has been developed on the concept of "long life and continuous run" and can be combined with brushless motors. The product lineup is enriched by the quiet type RB-35C employing a helical gear at the first stage and RB-35P most suitable for intermittent run.
Small torque but thinner and quieter design is possible.
90% per stage
Input-output position:
Same center or different center
Input/output rotating direction:
Varies depending on number of stages

(Planetary gear)
Diameter Rated torque Reduction ratio
IG-10 NEW f10 MAX 147mNm 1/16-1/1024
IG-13V f10 MAX 294mNm 1/16-1/425
IG-16 f12 MAX 196mNm 1/4-1/843
IG-16V f12 MAX 490mNm 1/19-1/850
IG-16R f12 MAX 588mNm 1/4-1/2418
IG-22C f13 MAX 196mNm 1/4-1/483
IG-22V f13 MAX 785mNm 1/4-1/509
IG-22R f16 MAX 981mNm 1/5-1/3125
(spur gear)
Diameter Rated torque Reduction ratio
RA-12R f12 MAX 147mNm 1/7-1/208
RA-16R f16 MAX 294mNm 1/10-1/1413
RB-35V f37 MAX 196mNm 1/32-1/792
RB-35C f37 MAX 490mNm 1/6-1/684
RB-35P f37 MAX 588mNm 1/6-1/3000
RB-38 f42 MAX 196mNm 1/11-1/270
RTJ-100 36×66 MAX 785mNm 1/151-1/908
RTJ-900 60×100 MAX 981mNm 1/24-1/706

    Planetary Gearhead
    (1) Bottom plate
    (2) Planetary gear
    (3) Carrier
    (4) Internal gear
    (5) Bearing
    (6) Output shaft
Planetary Gearhead

    Spur Gearhead
    (1) Bottom plate
    (2) Small gear
    (3) Shaft
    (4) Large gear
    (5) Bearing
    (6) Output shaft
Spur Gearhead

♦ Gearheads
A gearhead mechanism capable of increasing torque by reducing the motor speed. An approximate value can be calculated using the following equation. The reduction ratio has been established for each model. Please see the pages of products.
♦ Gear efficiency
Gearheads have mechanical loss (gear meshing, bearing friction, etc.). Generally, for each meshing of one stage, an efficiency of 81% for planetary gears and 90% for spur gears is used in calculation. The gear efficiency, however, varies largely depending on such factors as motor torque and speed therefore is presented as a reference value. When used at a lower torque, the efficiency will drop significantly.
      <An example of calculation of efficiency>
        ·Spur gear 3-stage meshing
          Efficiency(η)=0.9× 0.9× 0.9= 0.73(73%)
        ·Planetary gear 2-stage meshing
          Efficiency(η)=0.81× 0.81= 0.66(66%)
♦ Backlash
The amount of gearheads backlash depends on a play required for smooth meshing and a play between the shaft and the bearing. Note, however, it increases under load due to elastic deformation.
Backlash            Planetary Gearheads,Spur Gearheads
                Reference image