Design and Simulation of Ultrasonic Linear Motor using Multilayer Ceramic Actuator

In comparison with conventional electromagnetic motors, ultrasonic motors have many advantages such as a large torque at the low velocity, good controllability, rapid response, quiet operation, simple structure and non electromagnetic field induction, etc. These features have led to the development of various ultrasonic motors in many industrial fields. Hence, in this study, ultrasonic linear motor using multilayer structured ceramic actuator was designed and simulated using ANSYS of finite element method(FEM) simulator for investigating the optimum conditions of it. The ultrasonic linear motor studied in this paper was designed using the 1st longitudinal (L₁) and 4th bending (B₄) vibration. The size of ceramic actuator is 15 mm long and 5 mm wide. And one-layer thickness of actuator is 60 mu m. The dimension of linear motor is 61 times 5 times 3 mm. The sectional size of projection is 1.5 times 5 mm. The driving voltage of the motor was very low as 5 Vrms. With the increase of the number of piezoelectric ceramic layers, displacement of node was increased up to 21 layered ceramic actuator and then decreased. Maximum z displacement of node was about 7.02 mum at the 21 layered ultrasonic motor.