An Orthogonal and Stereoscopic Amplifying Mechanism with Nonparasitic Displacement for Parallel Piezoelectric Inchworm Actuators

In this paper, an orthogonal and stereoscopic amplifying mechanism (OSAM) is proposed, which can be applied to two degree-of-freedom parallel piezoelectric inchworm actuators, breaking away from the conventional thinking of designing driving mechanism for inchworm actuator within a single plane. OSAM, a stereoscopic driving mechanism, achieves displacement in the X and Y directions across two orthogonal planes using a single piezoelectric ceramic (PZT). Theoretically, it eliminates parasitic displacement beyond the desired output direction, effectively resolving the problem of coupling error associated with parallel inchworm drives. Hence, utilizing OSAM as the driving mechanism, inchworm actuators offer the advantages of nonparasitic motion, simple motion principle, and compact structure. Results show that under an input force of 100 N, OSAM achieves the output displacement of 159.21 µm in the X direction and 193.72 µm in the Y direction. The magnification ratio for the X and Y directions is 6.126 and 7.454, respectively. And the simulation results show that the structure has high resonant frequency and can satisfy the high frequency motion demand of piezoelectric actuator.