★ The paper presents a new design of standing-wave ultrasonic motor. ★ The specific design can internally amplify the deformations of the piezoelectric blocks by one or two orders. ★ The design enables the motor to have two different operating modes with same or similar natural frequencies. ★ The two operating modes superimpose with each other and generate elliptical trajectories on the driving contact head. ★ The motor achieves velocity in decimeter scale, satisfying fast speed requirement as a positioning actuator.
The purpose of this research is to present a new design of standing-wave ultrasonic motor. This motor uses three piezoelectric actuating blocks which deform appropriately when powered up. The deformations of the blocks in ultrasonic range are internally amplified via the design of the motor by about 80 times and collectively yield an elliptical trajectory for the driving head of the motor. Finite Element Analysis using ANSYS was performed for both dynamic analysis and optimization of a prototype motor. The numerical results verified that at steady state, the motor can achieve vibrations in micro-meter level and the velocity can reach decimeter scale, satisfying the fast speed requirement as a positioning actuator.