| 摘要 |
PURPOSE: To obtain a high efficiency with minimum consumption by selecting a set angle a to be equal to or a little larger than a static friction angle. CONSTITUTION: In a piezoelectric motor, a drive pin 2 is fixed in a hole 2a of a piezoelectric vibration element 1 and tilted at an angle α to a perpendicular line 3 to an armature 4 which can rotate around the axis 4a. The armature 4 is pressed against the free end of the drive pin 2 by a pressure shown by an arrow F. As the result, a contact surface of the drive pin 2 comes into contact with a friction surface 6 of the armature 4. The piezoelectric vibration element 1 generates vibration in the direction perpendicular to the friction surface 6 of the armature 4, in the direction indicated by a double arrow 7, and the armature 4 is moved in the direction of an arrow 8 every time when the surface 9 of the vibration element 1 approaches the friction surface 6 thereof. On the occasion, the angle αis selected to be equal to or a little larger than a static friction angle αH defined by αH=tan<-1> μ [μ denotes a coefficient of friction between the drive pin 2 and the friction surface 6]. Thereby a high driving efficiency is obtained. |
