Patent ID: 6852061

Claim:
A steerable wheel motor assembly for moving construction lifts and scaffold equipment comprising: a spindle bracket configured to be pivotably mounted at an upper end to the equipment for rotation about a vertical axis; an electric motor mounted to a lower end of said spindle racket, said motor having an output shaft that rotates about an axis when electrical power is supplied to the motor, said shaft positioned through a shaft opening into a hollow interior portion of the lower end of the spindle bracket; a substantially hollow cylindrical wheel hub mounted to said spindle bracket for rotation about a horizontal axis coincident with the axis of rotation of said output shaft; said wheel hub having an exterior surface to which a wheel can be mounted, an interior surface surrounding said hollow interior portion of the lower end of the spindle bracket, and an interior edge and an exterior edge between the exterior and interior surfaces, said hub supported for rotation by a first set of bearings positioned adjacent said interior edge of said hub, and a second set of bearings positioned inwardly from said exterior edge of said hub; a multi-stage planetary gear system mounted around the output shaft of the motor and positioned within the hollow interior portion of spindle bracket and totally within the hollow cylindrical wheel hub between said exterior edge and said interior edge, said planetary gear system having an input sun gear positioned between said second set of bearings and said exterior edge of said hub and mounted on the output shaft of said motor so that rotation of said output shaft and input sun gear provide input mechanical force to said planetary gear system, and an output ring gear positioned between said first set of bearings and said second set of bearings and joined to the interior surface of said wheel hub, said output ring gear engaging output planetary gears of an output stage of said multistage planetary gear system so that rotation of said output planetary gears causes said output gear and wheel hub to rotate so there is an advantageous application of mechanical force through the planetary gear system directly to the wheel hub.