| 摘要 |
PURPOSE:To improve efficiency, by a method wherein the bending oscillations of radial secondary and circumferentially tertiary or higher are employed as the oscillation modes of an ultrasonic motor while an oscillating body is attached to a shaft through a screw, threaded at the central part of the oscillating body. CONSTITUTION:The oscillating body 9 of an ultrasonic motor is provided with a small hole at the central part thereof while a screw 19 is threaded on the inner periphery of the small hole. The screw 20 is also threaded on a shaft 14 in the same manner. The shaft 14 is fixed to a base table 15 at the lower part of the shaft 14 while the oscillating body 9 is fixed through the shaft 14 and the screws 19, 20. A moving body 13 is attached to the upper part of the shaft 14 through a bearing 16 and is pressed against the oscillating body 9 by a leaf spring 17 and a pressure regulator 18 so as to contact the oscillating body 9. Said oscillating body 9 is constituted by bonding a piezoelectric ceramics 8 to one of the main surfaces of an elastic body 7. The structure of the electrode of the piezoelectric ceramics 8 is constituted so that the circumferential length thereof is equivalent to the 1/2 of a wave length and the like, therefore, the traveling wave of radial secondary and circumferential quartic bending oscillation is excited in the oscillating body 9. According to this method, the loss of the motor may be reduced and the motor, having a good efficiency, may be obtained. |
