Abstract: On a partition wall splitting the interior of a case into a gear chamber and a motor chamber, a through hole and a gutter member are provided. The through hole is provided for communication between the gear chamber and the motor chamber. The gutter member extends into the gear chamber below the through hole, and a tip end part thereof is provided above an oil storage part. Oil guided from the motor chamber into the gear chamber through the through hole of the partition wall is guided to the oil storage part through the gutter member, so that, for the oil storage part provided at a wall part not the partition wall of the case and not in contact with the partition wall, more oil can be stored.