Patent ID: 7455612

Claim:
A rotatively driving apparatus comprising: a first member; a second member, wherein the first member and the second member are relatively rotatable; a differential rotation amplification mechanism for amplifying a differential rotation between the first member and the second member; a rotor rotatable so as to interlock with an amplified differential rotation amplified by the differential rotation amplification mechanism; and a rotation controlling mechanism for controlling a rotation of the rotor, wherein the differential rotation amplification mechanism and the rotor are disposed on an identical axis, the first member comprises a rotating shaft coupled to a propeller shaft that transmits a torque from a main driving source, and the second member is a drive pinion shaft rotatably supported by a bearing supporting portion in a casing, and an electric motor is disposed on an outer peripheral side of the bearing supporting portion, and the rotor is rotatably supported by an outer periphery of the bearing supporting portion through a bearing.