A contact model of ring type traveling wave ultrasonic motors is proposed in this paper in order to investigate the dynamic contact and friction drive mechanism between the stator and rotor. Differing from previous contact models of ring type traveling wave ultrasonic motors, the Dahl friction model is adopted and the stator teeth are taken into account in the proposed model. The normal stress, the tangential stress, and the torque-speed characteristics of the motor are evaluated in detail based on the proposed model. Finally, the torque-speed values of the prototype motor are measured and compared with the calculation ones. The results show that the calculation values are in good agreement with the experimental values, which validates the proposed model. Moreover, the proposed contact model is compared with previous contact models that adopt Coulomb friction law and meanwhile ignore stator teeth by assuming teeth surfaces to be continuous. The comparison results show that the proposed model is more accurate than previous models.

为了研究定转子之间的动态接触和摩擦驱动机制，本文提出了一种环形行波超声电机的接触模型。与以往环形行波超声电机的接触模型不同，该模型采用Dahl摩擦模型，并在所提出的模型中考虑了定子齿。基于所提出的模型，对电机的法向应力、切向应力和转矩-速度特性进行了详细评估。最后，测量原型电机的转矩-速度值并与计算值进行比较。结果表明，计算值与实验值吻合良好，验证了所提出的模型。而且，所提出的接触模型与之前采用库仑摩擦定律的接触模型进行了比较，同时假设齿面是连续的，同时忽略了定子齿。比较结果表明，所提出的模型比以前的模型更准确。