An inertial piezoelectric plate type rotary motor

Investigation of a novel design inertial type piezoelectric motor is presented in the paper. Research was performed to validate operation principle and to investigate dynamic characteristics of the motor. Motor has simple design and consist of rectangular bronze stator, clamping frame, eight lead zirconate titanate (PZT) plates and a conical rotor. PZT plates are glued on the stator from both sides and are used to excite second in-plane bending mode. Excitation of the motor is carried out by two saw-tooth signals with phases shifted by π. Rotor is located at the center of the stator. Rotation motion of the rotor is based on stick-slip operation principle. Proposed piezoelectric motor is flat and can be used for the applications where space and mounting volume are critical. Numerical investigation of the piezoelectric motor based on finite elements method was performed in order to obtain natural frequency and modal shape of the stator, to investigate dynamic characteristics and to validate operation principle of the motor. Proper geometric parameters of the stator were obtained by solving optimization problem. A prototype of the motor was made and investigations of the mechanical, thermal and electrical characteristics were performed. The results of the numerical and experimental investigations are discussed.