Patent ID: 7270204

Claim:
An electrically motorized wheel assembly comprising: an axle support designed to be joined to a body of a carrier to be equipped with the wheel assembly; an axle supported rotatably by said axle support, the axle extending from said axle support in an axial direction thereof; a wheel mounted on said axle to be allowed to revolve on said axle, said wheel being made up of a hollow cylindrical wall and a center wall extending from an inner peripheral surface of the cylindrical wall inward to form an inner chamber which has an opening oriented toward the body of the carrier; a motor secured to the axle support to have an output shaft from which torque is outputted, the output shaft extending eccentrically from the axle and having a head extending into the inner chamber of said wheel close to the inner peripheral surface of the cylindrical wall of said wheel in substantially parallel to said axle; a torque transmission mechanism working to increase the torque, as produced by said motor, and transmit it to said wheel, said torque transmission mechanism being disposed in the inner chamber of said wheel; and a protective cover including a central hole through which said axle passes, an outer peripheral portion, and a motor mount, the outer peripheral portion extending inside said wheel through a gap between an outer circumference thereof and the inner peripheral surface of the cylindrical wall of said wheel, the motor mount having thereon said motor to have the head thereof extending inside the inner chamber of said wheel, said protective cover being retained by said axle support and extending in a radial direction of said wheel to substantially close the opening of the inner chamber of said wheel to hermetically enclose said torque transmission mechanism within the inner chamber.