Abstract: The vehicle drive device comprises a motor for driving wheels, an inverter for driving the motor, a rotational position sensor for detecting rotation of the motor, a gear mechanism for transmitting an output of the motor to wheels, an oil pump for circulating oil, and cases housing the motor, inverter, rotational position sensor, gear mechanism, and oil pump. The motor, inverter, rotational position sensor gear mechanism oil pump and cases are formed as an integral structure.

Abstract: The invention provides a power transmission apparatus for vehicle which can realize a high torque transmission efficiency and a high reduction gear ratio of a reduction gear unit with a more compact structure, and a vehicle-driving electric machinery system using the power transmission apparatus for vehicle. The power transmission apparatus for vehicle comprises a motor, a reduction gear unit for decelerating power outputted from the motor, and a differential gear unit for distributing the power decelerated by the reduction gear unit to left and right wheels. The reduction gear unit is a reduction gear mechanism including a plurality of gears mounted over a shaft which is rotatably held by a housing in a fixed position. The reduction gear unit and the differential gear unit are arranged within an area in oppositely facing relation to an axial end surface of the motor.