| 摘要 |
PURPOSE:To obtain an ultrasonic motor having a large turning force by equipping an apparatus with a vibrator using a piezoelectric ceramic plate formed into a circular arc, where two opposed short sides are inscribed in a circle, and with a torus circumscribed with said short sides in a manner of applying a static compressive stress bias to said sides. CONSTITUTION:A stator 11 is composed of a multiple mode vibrator of primary longitudinal-secondary bending vibration, and a rotor 12 is fastened with a bolt 13 so as to contact the stator 11 to apply a static compressive stress bias to the stator 11. On the other hand, when AC signals with phases differing 90 deg. from each other at a degenerate multiple mode vibrating resonance frequency are inputted to the stator 11, an elliptic vibration is forcibly excited in two contact faces of the stator 11 and rotor 12 so that said rotor 12 rotates. |
