| 摘要 |
PURPOSE:To rotate a rotor stably, by forming at least one of pressure contacting surfaces of a diaphragm and the rotor and of the rotor and a biasing member into a curved surface having a centripetal effect. CONSTITUTION:Within a case 1, a vibration-proof member 2, a piezoelectric element 3 and a vibrator 4 are arranged coaxially and integrally. The whole top surface of the vibrator 4 is formed into a gentle incline a. A contact surface of the rotor 5 with the vibrator is provided with an incline b complementary to the incline a. If a biasing member 7 is rotated, the rotor 5 and the vibrator 4 are in contact under pressure and a centripetal force by the effect of the inclines a-d is applied to the rotor 5. Therefore, a concentricity of the rotor 5 can be obtained, even if there is no rotor retaing mechanism such as a rotating shaft. |
