Vehicle power output device

A vehicle power output device for driving a first and second rotary electric machine (24, 64) in an efficient range in a wide driving region and for eliminating the need for a complicated mechanism and control. A planetary gear mechanism (30) combines the rotational drive force of a first shaft (26) rotationally driven by a first rotary electric machine (24) and the rotational drive force of a second shaft (66) rotationally driven by a second rotary electric machine (64) and transmits the combined rotational drive force to a drive shaft (32) with the rotational speed increased. The rotational drive force of the second shaft (66) in the forward direction is transmitted to the planetary gear mechanism (30) via a first one-way clutch unit (72) and a first power transmitting mechanism. The rotational drive force of the second shaft (66) in the opposite direction is transmitted to the drive shaft via a second one-way clutch unit (74) and a second power transmitting mechanism.