POWER TRANSMISSION DEVICE AND VEHICLE

[Problem] To protect a power transmission device from external heat. [0002] [Solution] This power transmission device comprises a motor, a gear mechanism connected downstream from the motor, and a box for accommodating the gear mechanism and lubricating oil. A first cooling box, into which a coolant for cooling the motor is introduced, is provided on the outer periphery of the motor. A second cooling box, which is connected such that coolant can circulate between the second cooling box and the first cooling box, is provided on the outer periphery of the box.