Basics of the electropiezoelasticity theory of piezoelectric motors with linear and rotary motion

Abstract

The paper presents the basics of the theory of electropiezoelasticity and adaptation of this theory to description of the simplest electromechanical converters − piezoelectric type electric motors. Because piezoelectricity and elasticity are coupled by complex piezoelasticity constitutive compounds, the formulation of a general mathematical model for these motors is not possible. Therefore, equations for structurally simple piezoelectric motors with linear and rotational motion have been formulated in the paper. Motors with linear movement are characterized by a flat or tube form. Rotary motors, on the other hand, have a cylindrical or disc-shaped form. The electric field, in the adopted forms of piezoelectric motors generating a piezoelectric effect, is a single-field perpendicular to the direction of motion. The determined equations could be simplified by reduction of some constitutive parameters, but it requires a detailed analysis of material compounds and consideration in the interactions of forces and torques in these motors, also strong piezoelectric stresses, which determine a specific kinetics. Keywords: piezoelectric motors with translational and rotary motion, equations of electric-piezoelasticity.