| 摘要 |
PURPOSE: To provide arm ultrasonic motor composed of a smaller number of parts and capable of obtaining stable pressurizing spring action. CONSTITUTION: The ultrasonic motor is provided with a rotor A having a shaft 5 and a frictional material 4, a stator B having a vibrating substance 1 and a piezoelectric substance 2 for generating an elastic surface wave, a frame 10, a bracket 9, a stator holder 13 aligned and fixed to the frame 10 for holding the stator B, and a frame-side bearing 7, a bracket-side bearing 6, a pressurizing coil spring 8 for pressurizing the frictional material 4 of the rotor A to the vibrating substance 1 of the stator B, and a thrust board 12 which is between the pressurizing coil spring 8 and the shaft 5, receives the force of the pressurizing coil spring 8 and transmits this force to the shaft 5, and has a diameter larger than that of the pressurizing coil spring 8. Besides, it has a cylindrical part 9a provided with a stepped part in the inner surface having the thrust board 12 and the pressurizing coil spring 8 inside provided on the pressurizing spring receiving side of the bracket 9. |
