PIEZOELECTRIC MOTOR USING CANTILEVER BEAM TWIST SUPERSONIC VIBRATOR

摘要

PURPOSE:To reduce the size and the weight and to increase the torque of a piezoelectric motor by press-bonding a rotor on the end of a supersonic vibrator which twists and bendably vibrates. CONSTITUTION:Piezoelectric thickness vibrators 31, 32 are formed of doughnut- shaped ceramics, and polarized through silver electrode films formed on the front and back surfaces. A terminal board 42 of the same shape as the vibrators is interposed between the positive electrode sides of two vibrators 31, 32, a terminal board 41 is superposed at the negative load side, aluminum washers 2, 5 are superposed on the outside, and a cap bolt 6 is passed through a bolt hole at the bottom side of the washer 6. A hollow shaft is erected at the center of a rotor 8, a bolt 10 is inserted through a coil spring 11 sandwiched by bearings 91, 92 at the shaft, and press-bonded to the end of the beam 11 by the spring 11 in the shape for supporting the rotation of the rotor 8 by the bearings 91, 92. Leads 71, 72 are passed through the vibrators 31, 32 and a sinusoidal wave voltage is applied to rotate the rotor 8.