Study of a Spherical Ultrasonic Motor for haptic display system

In this paper, we examine a Spherical Ultrasonic Motor (SUSM) for the haptic display system. Experimental system consists of a force sensor and a SUSM comprising one spherical rotor and three ring-shaped stators. The stator is made from an elastic body and piezoelectric elements for vibration. The stators and the rotor are in pressure contact with each other. The frequency and the phase difference of the stators' vibration can be controlled and we can generate torque of the rotor. Some experiments were briefly investigated to examine the performances of the proposed haptic display method.