US Patent 11548590 Drive unit and electrically assisted vehicle

A drive unit includes an electric motor including an output shaft including an output gear; a pedal crank shaft extending through a housing, rotatably supported by the housing, and including a driven gear; and a transmission to transmit a torque of the output gear of the electric motor to the driven gear. The transmission includes a decelerator rotatably supported by the housing, and an idle gear rotatably supported by the housing. The decelerator increases the torque of the output shaft of the electric motor, and the increased torque is transmitted to the driven gear via the idle gear.