A generator motor includes a stator, a rotor that rotates relative to the stator, and a motor housing that houses the stator and the rotor. The motor housing includes a housing main body that encloses a periphery of the stator and the rotor and a cover that is attached to an end surface of the housing main body so as to cover an opening formed on the end surface, which is on an opposite side to an engine, of the housing main body. A drain hole for draining water inside the motor housing to below the motor housing is formed between a lower end of the cover and the end surface of the housing main body. The motor housing includes a covered section that covers the drain hole from below at a position that is lower than the drain hole.