Patent attributes
A universal wheel driving system includes a sun gear provided to receive power from a power source, a ring gear provided so that a rotation axis thereof is moved relative to a rotation axis of the sun gear and a wheel is concentrically connected to the ring gear, at least one gear train engaged to the sun gear and the ring gear and configured to allow relative motion between the rotation axes of the sun gear and the ring gear and to form a continuous power transmission state therebetween, a carrier constantly supporting a position of a rotation axis of a final pinion of the at least one gear train with respect to a position of the rotation axis of the ring gear, and a suspension portion configured to support the carrier to be movable upward and downward with respect to a vehicle body.