摘要 |
PURPOSE:To suppress noise by setting the differential inherent vibration of standing wave having vibration mode lower than the differential inherent vibration which may cause noise. CONSTITUTION:A vibration wave motor comprises an elastic body 28, a piezoelectric element, a rotor, and the like. The elastic body 28 is formed into a ring and a plurality of grooves are provided at the side of pressure contact face. Forty grooves 28b-28o are made slightly deeper than other groove 28a in order to prevent generation of progressive wave in unnecessary mode and the dynamic rigidity is varied. By such arrangement, generation of unnecessary progressive vibration wave can be prevented. |