| 摘要 |
PURPOSE:To reduce set driving frequency and the resonance frequency of a stator by providing a vibrator being stuck to the stator and generating progressive waves, a means pushing a rotor against the stator by specified welding force and an adjusting means diminishing welding force when load torque is increased. CONSTITUTION:When a piezoelectric vibrator 9 is supplied with AC power, the piezoelectric vibrator 9 is expanded and contracted, and progressive-wave vibrations are generated on a stator 7. A stabilizer 12 is disposed between a rotor 10 and a belleville spring 11 so that the welding force of the belleville spring 11 is applied uniformly onto the whole circumferential surface of the rotor 10, a welding-force adjusting mechanism is composed of cam faces 6b, 16b and steel balls 17a, 17b, 17c, 17d, and the magnitude of load torque is converted into displacement in the axial direction of a holder 16. The rotor 10 is pushed against the stator 7 by weak welding force on large load. Accordingly, the difference of set driving frequency and the resonance frequency of the stator can be held at a small value. |
