针对行波型超声波电动机定子压电陶瓷(Piezoelectric,PZT)的胶粘问题,通过对定子的机电耦合效应有限元动力学模型的分析与计算,研究了胶粘层材料特性、厚度对超声波电动机定子振动特性的影响。重点分析不同激励条件下定子边缘缺胶和夹有气泡对胶层的抗剪切能力和定子振动特性的影响;分别从改进电动机定子结构和PZT粘结工艺方面探讨了提高胶粘层抗剪切能力的措施,确定了胶层最佳参数和电动机定子胶粘工艺及结构优化设计思想。结果表明:胶层厚度对电动机定子频率影响不大,但对其振动特性的影响较大,在保证可靠的粘结强度下降低胶层厚度有利于提高电动机性能。基于该工艺和设计思想研制的直径80mm行波型超声波电动机性能稳定,堵转力矩达到1.2N·m,空载转速80r/min,研究结果有助于超声波电动机的产业化。
Focused on the bonding of the piezoelectric ceramic of traveling wave type ultrasonic motors (TWUSM), the effects of the material characteristics and the thickness of the adhesive layer on the vibrating performances of the stator are studied based on the electromechanical coupling finite element model of the stator, and the resisting-shear and vibrating performances of the adhesive layer under different excitating conditions are detailedly analyzed. The methods of improving the bonding quality of the piezoelectric ceramic are presented, and the bonding process and the optimum design of the TWUSM stator are determined at last. It is shown that the thickness of the adhesive layer has little effect on the stator frequency, but great effect on the stator vibration characteristics, and on the premise of enough bond strength, reducing the thickness of the adhesive layer can improve the performance of the TWUSM. Based on the bonding process and optimum design, the 80 mm TWUSM prototype has a good performance that the maximum torque is 1.2 N · m and the no-load rotational speed is 80 r/min.The researching results contribute to the industrialization of USM.