COMPUTER SIMULATION AND MODELLING OF STANDING WAVE PIEZOELECTRIC ULTRASONIC MOTOR USING A SINGLE FLEXURAL TRANSDUCER

This paper presents a standing wave piezoelectric ultrasonic using a flexural vibration transducer. The motor consists of three main parts, stator, rotor and sliding element. The stator is a single piezoceramic flexural vibration bar. The rotor is made up of the motor driving wheel and the shaft. A computer simulation and modelling using finite element analysis for the proposed motor is discussed and used in the motor design development process. Finite element analysis has been used to evaluate the motor structure by performing an algebraic solution of a set of equations, describing an ideal model structure, with a finite number of variables. The established simulation and modelling for ultrasonic motor using finite element analysis enabled to select, the material of the flexural transducer, defining the operating parameters for the motor, determining the principles of motion and proposing an innovative technique to control the direction of motion, by controlling the phase between the two modes of vibrations. This enabled to create two directions of motion from a single vibration bar. A prototype of the proposed motor was fabricated and measured. This showed that operating parameters of the fabricated prototype are: frequency equal to 40.7 KHz, voltage: 50: 100 volt and current: 50: 100 m-amperes. This is showed a close agreement with FEA. Typical output of the prototype is no-load travelling speed of 28 mm/s, a resolution on the order of micrometers and a dynamic response <100 mu sec. The motor is able to carry a load equal to 0.78 Newton. The developed motor has been used successfully in EDM industrial applications.