US Patent 11938809 Universal driving device

A universal driving device includes a sun gear rotatably provided; a ring gear disposed on a rotation plane coplanar to a rotation plane of the sun gear and provided so that a rotation shaft of the ring gear is movable relative to a rotation shaft of the sun gear; and a gear train engaging the sun gear to the ring gear and configured to allow a relative motion between the rotation shaft of the sun gear and the rotation shaft of the ring gear and define a continuous power transmission state between the sun gear and the ring gear.