Development of Ultrasonic Micro Motor with a Coil Type Stator

Abstract

The motor is one of the most important actuators and its miniaturization is strongly desired in the market in order to make electro – mechanical systems as small as possible. Ultrasonic motors are commercially applied to a focussing device of camera and etc. and there exists further demands to miniaturize them so as to adopt to mobile phone, automobile actuators, and micro surgery devices like IVUS. However, the conventional ultrasonic motors are based on a surface propagation and transmission of vibration wave, inevitably, they need many parts and there is a certain limit to miniaturize. Taking these points into account, the present paper proposes a new concept [1,2] in which a coil type stator contacts on a cylindrical rotor directly, hence, the structure becomes very simple and can realize miniaturization. Four different types of ideas and prototypes are proposed, manufactured and tested their fundamental performances.