Study on the vibration couplings of a traveling wave piezoelectric stator excited by a longitudinal and bending hybrid transducer

In a previous study, the authors have proposed, designed and fabricated a cylindrical traveling wave piezoelectric motor excited by a longitudinal and bending hybrid composite transducer. This study focuses the research on the vibration coupling problems of the proposed stator. After the introduction of the working principle of the motor, harmonic analysis is developed to gain the input impedance characteristics of the longitudinal and bending vibration modes of single transducer; the electromechanical coupling factors are calculated to evaluate the energy transfer efficiency. Then, the input impedance characteristics of the two vibration modes of the stator are analyzed to gain the corresponding electromechanical coupling factors. At last, the resonance frequencies of the transducer and cylinder are adjusted to obtain their effects on the electromechanical coupling factors. The study results can guide the design of traveling wave motors that utilized sandwich transducers as actuators.