121(10G) Types (Double clutches)

These share the same basic structure as the 121-[ ]-20 type clutch/brake units. They are double-clutch units that have a through-shaft structure and place clutches (101-[ ]-15 types) at both ends of the drum.The hub may be used as the input for two-stage speed-change/forward-reverse operation, or the shaft may be used as the input for power distribution or the like. Select the input method that works best for you. Just as with the 121-[ ]-20, the construction holds up well under radial loads due to a wide bearing span, so it can be used under high tension when mounted with V pulleys, spur gears or the like.

121 (10G) Types


ModelSizeDynamic friction torque Td [N・m]Static friction torque Ts [N・m]Coil (at 20℃)Heat resistance classMax. rotation speed [min-1Rotating part moment of inertia J [kg・m2Total work performed until readjustment of the air gap ET [J]Armature pull-in time ta [s]Torque build-up time tp [s]Torque decaying time td [s]Mass [kg]
Voltage [V]Wattage [W]Current [A]Resistance [Ω]For hub inputFor shaft input
121-06-10G0655.5DC24110.4652B30001.55×10-41.05×10-436×106C: 0.020/B: 0.015C: 0.041/B: 0.033C: 0.020/B: 0.0151.7
121-08-10G081011DC24150.6338B30004.75×10-43.00×10-460×106C: 0.023/B: 0.016C: 0.051/B: 0.042C: 0.030/B: 0.0253.1
121-10-10G102022DC24200.8329B30001.44×10-39.45×10-4130×106C: 0.025/B: 0.018C: 0.063/B: 0.056C: 0.050/B: 0.0306.5
121-12-10G124045DC24251.0423B30004.50×10-32.75×10-3250×106C: 0.040/B: 0.027C: 0.115/B: 0.090C: 0.065/B: 0.05010.5
121-16-10G168090DC24351.4616B30001.34×10-29.05×10-3470×106C: 0.050/B: 0.035C: 0.160/B: 0.127C: 0.085/B: 0.05521
121-20-10G20160175DC24451.8813B25004.18×10-22.65×10-210×108C: 0.090/B: 0.065C: 0.250/B: 0.200C: 0.130/B: 0.07038.5
121-25-10G25320350DC24602.509.6B20009.80×10-27.45×10-220×108C: 0.115/B: 0.085C: 0.335/B: 0.275C: 0.210/B: 0.12570

*The dynamic friction torque, Td, is measured at a relative speed of 100 min-1. Depending on the initial torque characteristics, break-in to condition the engaging surfaces may also be required.

*The rotating part moment of inertia for shaft input is the value with one armature type-5.


SizeDimensions of part
SizeShaft dimensions
Q1 Q2 S1 S2 U1 U2 V1 V2 X1 X2 W1, 2
062520113812.539.5M4×0.7, length: 83-M4×0.7, length: 43° to 120°60°4
08302514451647M4×0.7, length: 83-M4×0.7, length: 63° to 120°60°5
10403019552157M6×1, length: 114-M4×0.7, length: 84° to 90°45°5
12504024642767M6×1, length: 114-M4×0.7, length: 84° to 90°45°7
16605028753178M6×1, length: 116-M5×0.8, length: 86° to 60°30°7
208060389041.593.5M10×1.5, length: 174-M6×1, length: 124° to 90°45°10
25110704211545.5118.5M10×1.5, length: 178-M6×1, length: 128° to 45°22.5°12

*The input/output keyways are old JIS standard class 2 while the key is old JIS standard class 1. Note that the keyway dimensions of the unit hub part do not conform to JIS standards. Check them on the dimensions table above.

*When inserting pulleys or the like onto input/output shafts, use the supplied insertion set.

*The 121-25-10G base is a casting.