US Patent 11511623 Power transmission device and vehicle including the same

A power train for a vehicle, the power train includes: a motor including a rotatable shaft; a reducer coupled to the motor; a gear train disposed at least partially inside the reducer, to transmit rotational force generated by the motor; and a wheel rotatable by receiving power from the reducer or by transmitting power generated by its rotation to the reducer, wherein the gear train is configured to transmit power from the motor to the reducer or to transmit power from the reducer to the motor based upon comparison of a rotational angular velocity of the rotatable shaft and a rotational angular velocity of the reducer.