A stick-slip piezoelectric actuator with high assembly interchangeability

The stick-slip piezoelectric actuator with simple driving signal and structure is a very promising type for achieving the high resolution and large stroke. However, as a typical actuator working by the friction-inertia principle, the contact between the stator and mover requires precise adjustment, which brings difficulty for the assembly of the actuator. Excessive assembly errors may even cause the piezoelectric actuator to fail to work. Accordingly, to decrease the effects of assembly factors on the output performances and enhance the assembly interchangeability of stick-slip piezoelectric actuators, a method of low stiffness contact was proposed in this study, which used the flexible foot to replace the generally employed rigid foot with high stiffness. By comparing with the rigid foot actuator, the feasibility of the proposed method was theoretically analyzed first. Then, the effects of preload deformation and three potential assembly errors (deflection, overturning and pitching) on the output performances were characterized. Finally, a highly interchangeable actuator with compact structure was designed, and its abilities for quick disassembly and assembly, interchangeability of the stator and large-stroke stable motion were tested. Experimental results indicated that the proposed actuator can achieve good motion stability and high interchangeability. The strategy of low stiffness contact can significantly decrease the assembly requirement, which is beneficial to the practical production and application of stick-slip piezoelectric actuators.