ROD-TYPE ULTRASONIC MOTOR USING 2 DEGENERATE 2ND FLEXURAL VIBRATION MODES AND CHARACTERISTIC CONSIDERATION USING ITS EQUIVALENT-CIRCUIT EXPRESSION

This paper deals with a simplified equivalent circuit of an ultrasonic motor and its application to the estimation of motor characteristics. Investigation of this equivalent circuit is conducted from the viewpo int of systematization of research on ultrasonic motors. The equivalen t circuit must follow the principle of motor operation and must be exp ressed simply. We have considered the characteristics of an ultrasonic motor using its equivalent circuit expression. We propose simplified equivalent circuits of a rod-type ultrasonic motor using the two degen erate second flexural vibration modes; moreover, we show that the maxi mum torque, the suitable load, and power transmission can be easily es timated. As a result, we found that the estimated maximum torque was s ufficiently close to the measured one and that the power transmission could be estimated by correction of the measured value of internal res istance.