A Novel Worm Drive for Rehabilitation Robot Joint

Aiming at the rehabilitation robot joint, a novel worm drive consisting of a planar internal gear and a crown worm is presented. Theoretical calculation confirms that small induced principal curvatures, big sliding angles and large meshing area exist on the conjugate surfaces, indicating that the new worm drive is of smaller contact stress and better lubrication. A new machining method for crown worm is proposed based on the principle of virtual center distance. The crown worm and planar internal gear are manufactured. This study is expected to give rise to a new insight on the design of the future rehabilitation robot joint.