A novel stick-slip piezoelectric rotary actuator designed by employing a centrosymmetric flexure hinge mechanism

Abstract

Although the stick-slip piezoelectric linear actuators have been widely investigated, the design of stick-slip piezoelectric rotary actuators is rarely reported and the corresponding output performances could be further improved. In this study, by employing a centrosymmetric flexure hinge mechanism, a novel stick-slip piezoelectric rotary actuator was designed. Its structure and working processes were addressed in detail, and the main structural parameters of the centrosymmetric flexure hinge mechanism were designed by the finite-element method. After that, a prototype was fabricated and a series of experiments were performed to test its output performances. The experimental results showed that under various driving voltages, the actuator could output stable angular displacement, and with increase in the driving voltage, the angular speed tended to linearly increase. Under the driving voltage of 100 V and driving frequency of 600 Hz, the actuator reached a maximum angular speed of about 55 000 μrad s−1. The driving resolution of the actuator was 0.34 μrad, and the maximum vertical loading capacity and torque were tested to be 6 kg and 30 N · mm, respectively. In addition, both clockwise and anticlockwise rotations were realized by simply changing the direction of the driving voltage waveform, and furthermore, under the same experimental conditions, very similar output performances were achieved in clockwise and anticlockwise rotations. Compared with some previously reported stick-slip piezoelectric rotary actuators, it was confirmed that the vertical loading capacity and driving resolution of the designed actuator here had been improved, which would be beneficial to its practical application.