US Patent 7775060 Drive unit for electric vehicle

A drive unit for an electric vehicle is comprised of a motor, an inverter which supplies alternating current electric power to the motor, a speed reducer which is connected to the motor, and a cooling system which cools the motor, the inverter and the speed reducer. The speed reducer reduces a revolution speed of a mechanical output of the motor. The cooling system comprises a heat exchanger at which first refrigerant for receiving heat of at least one of the motor and the inverter receives heat of second refrigerant for receiving heat of at least one of the motor and the speed reducer.