A rear wheel driving unit of a hybrid vehicle includes an oil catch tank that stores oil splashed from an oil sump formed on a bottom of a casing body by a driven gear of a differential. A slinger chamber to which the oil is supplied from the oil catch tank has a slinger disposed therein that is driven by the motor through gears. To cool the motor, the oil is supplied from the oil catch tank to an oil passage in a main shaft leading to the inside of a motor shaft by gravitational force. The oil splashed from the slinger chamber by the slinger is supplied to the oil passage to effectively cool the motor using the lubricating oil from the differential.