Variable Ratio Transmission Elements for Motor Drive Shafts
A motor transmission element includes an axle, an expandable circumferential component and multiple rolled electroactive polymer (EAP) devices. The circumferential component is located at a contact radius from the axle for connection to a different rotating body and is mechanically connected to the axle. The rolled EAP devices are mechanically connected to the circumferential component and the axle. Each rolled EAP device has a pair of input electrodes and is configured to deform substantively parallel to a roll longitudinal axis upon application of a voltage difference. Deformation of a rolled EAP device causes a change in the contact radius. A voltage difference that expands the rolled EAP device increases the contact radius, and thereby the circumference of the transmission element. By varying the voltage, a continuously variable ratio can be achieved between a rate of rotation of the transmission element and a rate of rotation of the second body.
Patent Status: U.S. patent(s) 7075213 issued.CONTACT: