Development of the translational and rotational piezoelectric actuator using a single stator (1st report) - Design of the stator by finite element mothod analysis

We report the development of a piezoelectric actuator having a single stator with rotational and translational motion (TR motor). The stator has been fabricated as a rectangular metallic solid with a through-hole. The surface of the inner circle of the hole generates rotational and translational vibration modes, transferring the energy to a shan, when the voltage at each resonant frequency is applied to the piezoelectric elements. In this paper, the driving principle of the TR motor was clarified using finite element methods (FEM). The characteristic analysis showed the mode shapes and the natural frequency, and then the figure of the stator was designed. The dynamic analysis of the inner surface generated elliptical motions and indicated the motions of the TR motor. Several stators of TR motor were made varying the figure of the length in direction to the axis. The impedance characteristics of the stators have accorded with the simulation.