PURPOSE: To control input torque constant and eliminate differential phoenomena by controlling the torque of an input shaft directly with either of right or left DCM, and synchronizing the speeds between right and left axle shafts.

CONSTITUTION: The driving of a DC motor M2 is controlled with a torque controller 301, and a DC motor M3 with a speed controller 5-2. The difference between the reference torque TP' from a torque setter 4 and the output of a torque meter 2-1 provided to an input engine shaft is determined with an operational amplifier 8-2, and a torque controller 3-2 controls the absorption torque of the motor M2 so as to make said difference zero. The difference in the number of revolutions of the respective motors M2, M3 outputted from pilot generators 7-2, 7-3 is determined with an operational amplifier 8-3, and the controller 5-2 controls the number of revolutions of the motor M3 so as to make this difference zero. if TP' is given, the torque of an input engine shaft 10 is controlled under the constant value thereof. The M2 and M3 share and absorb the torque of the input engine shaft equally and the TP' us generated in the input engine shaft.