Abstract: A new time domain drive model of longitudinal and torsional hybrid type ultrasonic motor(TLHUSM) is developed using dynamic principle. The load characteristics of the test TLHUSM, such as revolution speed, torque, and efficiency，can be calculated numerically by means of this model. It is shown that the measured load characteristics of the motor agree with calculated that by using the model. As a result, the validity of proposed model is experimentally confirmed. The proposed model can be used as theoretical guidelines for design and characteristic evaluation of the TLHUSM.

Key words: Hybrid type, Standing wave, Time domain model, Ultrasonic motor