A piezoelectric inchworm actuator based on the principle of flexible amplification

Piezoelectric inchworm actuators have a wide application in the field of Nano positioning and ultra-precision detecting instruments which depend on the characteristics of large stroke, high resolution and rigidity, quick response speed, small size, high driving force, low power consumption, not being affected by electromagnetic interference, and so on. A new piezoelectric inchworm actuator based on the principle of flexible amplification is developed in this paper. In the moving mechanism of the actuator, its clamping mechanism adopts symmetrical lever amplification structure, and its middle drive mechanism uses compound bridge structure. Theoretical analysis and finite element analysis are carried out to design the hinge structure which has influences on the properties of the moving mechanism. High precision cross roller guide ways are utilized to improve the positioning accuracy of the actuator. The laboratory platform of the piezoelectric inchworm actuator is built. A controlling program of the actuator is compiled by Lab-VIEW. Then, the properties of the actuator are tested. The experimental results show that the working stroke of the actuator is 50 mm, the minimum step pitch is 60 μm the maximum step pitch is 105 μm the fast speed is 2.04 mm/s, the maximum clamping force is 21 N, the maximum dead load is 500 g, and the average speed of the actuator can reach 1.47 mm/s when the driving frequency is 50 Hz and the load is 1 kg.