US Patent 7990004 Reduction drive device

A reduction drive device is compact, hardly causes an electric motor thereof to vibrate, and has improved noise/vibration controllability. The reduction drive device includes the electric motor attached to a casing and capable of outputting torque, first and second reduction mechanisms supported by the casing, to reduce and transmit the rotational output of the electric motor, and a rear differential supported by the casing, to distribute the rotational output reduced by the first and second reduction mechanisms to a pair of axle shafts. Rotor, stator, and brush of the electric motor partly overlap the rear differential when seen in a rotation radius direction.