| 摘要 |
PURPOSE:To promote conversion efficiency by forming a stator from an amorphous glass having a large friction factor and a small oscillation absorption factor. CONSTITUTION:An ultrasonic motor is such that a rotary shaft 9 is supported through a bearing 12 on a boss of the central part of an generally disc-like base 4. A spacer 11 is supported on the base 4, on which the circumferential edge of an internal hole of an generally flat ring-like stator 3 is disposed. An external thread is made on the periphery of the boss of the base 4 and is screwed into an internal thread of a holder 10 so that the stator 3 has the spacer 11 and the holder 10 together as a unit. At that time, the stator 3 is constituted of an amorphous glass 1 of SiO2-Al2O3-Y2O3-La2O3 and a ring-like piezo-electric element 2. Accordingly, when alternating voltage is applied, the piezo-electric element 2 oscillates and generates a traveling wave, and a rotary body 6 is pressed down by a flat spring 13 through a rubber sheet 14, so that a friction member 7 of a rotor 8 is brought into contact with the upper part of a tooth G of a large diameter ring section of the glass 1, and moment of rotation is provided. |
