Research of a leaf spring ultrasonic motor

This paper analyses a kind of leaf spring ultrasonic motor (USM). A radial vibration of the stator is excited by PZT and then the radial displacement is converted to a rotation of the rotor by the bending of leaf springs. The dynamics model of the motor is firstly studied by theoretical method and then the amplitude-frequency characteristic of the stator is calculated by the Finite Element Method (FEM). A prototype is fabricated and impendence-frequency characteristics are tested. The experiment results are in good agreement with theoretic analysis which verify the reasonableness of the theoretic model.