Eccentric differential screw actuating, torque multiplying and speed changing device

摘要

An eccentric differential screw usable for torque multiplying, speed changing, positioning and actuating functions is disclosed. The disclosed device produces output between fixed output member positions. A rotatable shaft having threaded portions, constrained axially, acting as a screw, is threadably engaged by fine threads to a floating nut-screw acting as a nut. The same floating nut-screw acting as a screw axially eccentric with respect to the axis of the said fine threads is threadably engaged by coarse threads to a rotatable nut. The unique motions of the parts and the self-locking behavior of the device being made achievable by the eccentricity of the axes of the said fine and coarse threads. The speed ratio of the device is dependent on the ratio of the leads of the fine and coarse threads.