| 摘要 |
PROBLEM TO BE SOLVED: To allow a vibrating body to vibrate stably and prevent suppression of vibration by installing, at the nodes of vibration of the vibrating body, elastic support members which elastic-deform according to the vibration condition of the vibrating body and support the vibrating body against pressure. SOLUTION: This ultrasonic motor has projections 13 for expanding vibration and elastic supporting members 18a, 18b formed on an upper face of a vibrating body 12. The projections 13 not only expand the vibration displacement of the vibrating body 12 and transmits it to a rotor body but also transmits pressure to the vibrating body 12. With a piezoelectric element excited, progressive waves appear in the circumferential direction on the vibrating body 12 and nodes appear at the positions 12b, 12c in the diameter direction, but the elastic support members elastic-deform at other positions than the nodes according to the vibration displacement of the vibrating body 12. Furthermore, pressure is applied to the vibrating body 12 through the projections 13 and generates bending moment downward in the vibrating body. However, the elastic support members 18a, 18b apply force against the pressure to the vibrating body and lessen the bending moment. By this method, the vibrating body can be allowed to vibrate stably and suppression of vibration can be prevented. |
