An Impact Inertial Piezoelectric Actuator With High Thrust–Weight Ratio Driven by Coupling the Inertial Force and Friction Force

Impact inertial piezoelectric actuators are favored with their simple control and structure, high resolution, etc. However, achieving a high thrust–weight ratio remains a challenge due to the positive correlation between the thrust force and inertial mass. To address this issue, an impact inertial piezoelectric actuator driven by coupling the inertial force and friction force is proposed in this article. Then, the corresponding structural design, operating principle, force analysis of the motion process, and parameter determination of the actuator were discussed in detail. An actuator prototype with the size of 32 × 29.4 × 6 mm ³ and mass of 8.2 g was manufactured, and a series of tests were performed under various preload deformations, voltages, frequencies, and loads. The experimental results showed that the actuator driven by coupling the inertial force and friction force could effectively enhance the thrust–weight ratio, and it achieved a maximum thrust–weight ratio of 54.42, far surpassing other actuators of the same type. Meanwhile, the actuator exhibited a maximum thrust force of 4.46 N, comparable to actuators with larger inertial masses. Furthermore, the actuator possessed excellent frequency stability and good adaptability in the motion angle and preload deformation.