Design of a Cross-Type Ultrasonic Rotary Motor with a Simple Structure

摘要

In this study, the characteristics of a novel ultrasonic rotary motor with a cross-type stator were investigated. The previous cross-type ultrasonic motor had a stator with 8 piezoelectric ceramics of different poling directions attached, but the new cross-type ultrasonic motor had a stator with only 4 ceramics. The number of ceramics can be reduced by controlling the poling direction of the ceramic. To get an optimized design for the new cross-type ultrasonic motor, we simulated an elastic body by changing the size of the stator. The displacement of the stator was examined by using a finite element analysis. When the thickness of the elastic body was decreased, the displacement increased. When the thickness of the elastic body was decreased, the displacement that occurred in a direction tangential to the contact surface decreased. When the ceramics was thin, the displacement of the stator was observed to be large. These results indicate that the crosstype ultrasonic motor can be miniaturized by controlling the size and the resonant mode of the elastic body.