| 摘要 |
PURPOSE:To improve efficiency, by a method wherein a disc type oscillating body is employed as an oscillating body while radial secondary and circumferential tertiary bending oscillation is employed as the oscillating mode of an ultrasonic motor. CONSTITUTION:The oscillating body 9 of an ultrasonic motor is constituted of a piezoelectric ceramics 8, bonded to one of the main surfaces of a disc type elastic body 7. A projection body 10 for the take-out of a mechanical output is provided on the other main surface of the elastic body. A moving body 13 is constituted of the friction member 11 of wear-resistant material and another elastic body 12, which are bonded to each other. The moving body 13 contacts the projection body 10 of the oscillating body 9 with a pressure through said friction member 11. Further, the structure of the electrodes of the disc type piezoelectric ceramics 8 is provided with a length equivalent to the 1/2 of a wave length in the peripheral directions respectively with the group of electrodes EF, whose directions of polarization of neighboring electrodes are reverse to the direction of the thickness of the electrodes whereby the traveling wave of radial secondary and circumferential tertiary bending oscillation is excited in the oscillating body 9. As a result, the kinetic energy of the oscillating body 9 is increased. |
