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 cross-type ultrasonic motor can be miniaturized by controlling the size and the resonant mode of the elastic body.