定子表面织构对超声电机性能的影响

针对超声电机摩擦材料磨损严重和温升高的问题，采用在定子表面加工微织构的方法，提高了电机机械特性并降低了摩擦材料磨损. 首先，用显微镜测量超声电机定子表面摩擦材料黏着区域，设计出三种不同密度的凹坑织构，采用激光的方法加工在定子表面；然后，测试超声电机负载特性、效率特性和温升特性并观察定子表面. 结果表明:3-凹坑织构定子电机空载转速最高，相比光滑定子电机高出12.1%，5-凹坑织构定子电机堵转转矩和最大效率最高，分别高于光滑定子电机13.04%和17.1%，同时电机的温升也有所降低. 通过观察定子表面发现，凹坑织构有大幅降低摩擦材料黏着的作用，这种作用可以增加电机接触界面能量转换效率，提高了电机的性能并降低了摩擦材料的磨损. 

Effect of Stator Surface Texture on the Performances of an Ultrasonic Motor

Aiming at the problem-solving of the severe wear and temperature rise of friction materials used in ultrasonic motors, by using the method of fabricating micro-texture on the stator surface, the mechanical properties of ultrasonic motor was improved and the wear of friction material was reduced. Firstly, the positions of material adhesive area on the stator surface was measured by a microscope. After that three different density textures were designed and fabricated on stator surface by laser. Then, the speed-torque characteristics, efficiency-torque characteristics and temperature rise of the motor were tested. Meanwhile, the stator surface was observed. The results showed that the no-load speed of 3-dimple-texture stator was the highest, which was 12.1% higher than that of smooth stator. The stall torque and efficiency of 5-dimple-texture stator was the highest, which were 13.04% and 17.1% higher than that of smooth stator motor respectively. The temperature rise of textured stator was also reduced. By observing stator surface, it was found that the dimple texture greatly reduced the adhesion of the friction material, which can increase the energy conversion efficiency of the motor contact interface, improved the motor performance and reduced the wear of the friction material.