Forecasting model for the ideal pre-force of cylindrical bending rotation ultrasonic motor

The force factor formula of stator based on bending vibration and piezoelectric plate sandwich was deduced. It indicated that, aiming to the ultrasonic motor whose stator uses the bending vibration mode of free beam, disposing the PZT elements on the great strain which was the wave loop of bending vibration was the optimal method. A forecasting model for the ideal pre-force of cylindrical bending rotation ultrasonic motor was established. The forecasting model illuminated that the ideal pre-force was a performance parameter which had some relationship to the factors such as input exciting voltage, stator dimensions, PZT element dimensions and disposed positions. A prototype of cylindrical bending rotation ultrasonic motor was utilized to validate the forecasting model. The results showed that the values of forecasting and testing were 21.6 N and 20 N, respectively, and the two methods got a good agreement.