Design and Experiment of a Clamping-Drive Alternating Operation Piezoelectric Actuator.

In recent years, piezoelectric actuators, represented by inertial and inchworm actuators, have been widely applied because of their high accuracy and excellent responsiveness. Despite the development of various piezoelectric actuators, there remain some flaws in this technology. The sticking point is that the piezoelectric actuators based on the friction driving principle are prone to unwanted backward motion when outputting stepping motion. It is thus urgent to explore solutions from the perspectives of principle and structure. In this paper, a clamping-drive alternating operation piezoelectric actuator is proposed, the two feet of which are driven by two piezoelectric stacks, respectively. Due to double-foot alternate drive guide movement, backward movement is prevented in theory. By adopting the double-layer stator structure, integrated processing and assembly are facilitated. Meanwhile, a double flexible hinge mechanism is installed in the stator to prevent the drive foot from being overturned due to ineffectiveness and premature wear. In addition, the stator is equipped with the corresponding preload mechanism and clamping device. After the cycle action mechanism of one cycle and four steps is expounded, a model is established in this study to further demonstrate the principle. With the prototype produced, a series of experiments are performed. In addition, the amplitude of actuation of the stator is tested through amplitude experiment. The performance of the stator is evaluated by conducting experiments in the alternating step and single step actuation modes. Finally, the test results are analyzed to conclude that the actuator operating in either of these two modes can meet the practical needs of macro and micro actuation.