Abstract
In this paper, we propose a novel rotor embedded disk type multi-degree-of-freedom (MDOF) spherical ultrasonic motor (SUSM). The MDOF-SUSM consists of a spherical rotor and a stator vibrator with all-in-one structure, the spherical rotor is embedded in a stator vibrator with a spherical inner surface, and a motor shaft is mounted on the rotor. The stator vibrator with piezoceramic disks and plates stuck on its surfaces can excite five vibration modes, independently and simultaneously. The spherical rotor of the motor can rotate around three axes by combining two vibration modes among the five vibration modes. This paper describes the basic construction and the operating principle of the rotor embedded type MDOF-SUSM, modal analysis results about the stator vibrator, and some measurement results from the first trial manufacture to verify the operating principle and research the Z-axis rotation. The MDOF-SUSM in this study has possibilities of a simple structure, compact and small size, lightweight, and a large torque-to-weight ratio.
