A pump includes an external gear, an internal gear surrounding the external gear to mesh with the external gear, a pump chamber to house the internal gear and the external gear, a suction inlet to suck an oil into the pump chamber, and a discharge outlet to discharge the oil from inside the pump chamber. The housing includes an outer cover having the pump chamber defined therein, and a first oil passage defined in the outer cover and connected to the discharge outlet. The motor shaft includes a second oil passage connected to the first oil passage, and a first through hole to connect the second oil passage to the motor shaft. The second oil passage opens into the first oil passage at the end portion of the motor shaft.