Modal analysis and moving performance of a single-mode linear ultrasonic motor

A single-mode linear ultrasonic motor was developed in this study. On the stator, a group of four pieces of piezoelectric ceramics PZT8 were utilized to generate the ultrasonic vibration. A specially designed modal conversion horn with an oblique beam was applied to transfer the longitudinal vibration to an additional bending vibration. Modal analysis was conducted by finite element method to illustrate the elliptical vibration process. Then the output performance (e.g. output thrust and output velocity) of the motor was evaluated via a series of experiments. The results show that the simulated amplitudes of longitudinal vibration and bending vibration are 9.6 μm and 3.4 μm, respectively, which match well with the tested results. The output thrust increases with the increase of voltage. The largest output thrust is 10 N at the voltage of 600 V_p-p, and the biggest output velocity is 200 mm/s at the supplied frequency of 19.8 kHz and the driving angle of 45°. The output velocity also decreases with the increase of applied load.