旋转型行波超声电机定子模态频率的一致性调节

从分析超声电机的工作机理出发,指出旋转型行波超声电机定子两相模态频率不一致影响超声电机旋转稳定性和输出效率。针对材料不均匀或加工误差引起的两相模态频率不一致的问题,利用结构摄动理论,通过求解定子的动力学方程,找到了调节两相模态频率一致性的方法。利用这一方法,以南京航空航天大学研制的某TRUM-60型超声电机为例,进行了AN SY S有限元计算,寻找合适的调节位置,并对两相模态频率不一致进行了调节,利用多普勒激光测振仪,对修改前后的定子的模态频率进行了测试,两相模态频率差从调节前的0.42kH z变为调节后的0.04 kH z。结果表明:这种方法对于调节定子两相模态频率的一致性是非常有效的。

Adjusting Traveling Wave Type Ultrasonic Motor Stator Modal Frequencies Into Coincidence

It is pointed out that the difference of the two modal frequencies affects the speed stability and the efficiency of the ultrasonic motor by analyzing operation mechanism of traveling wave type ultrasonic motor.The two modal frequencies are always different because of material property variation and machining errors.In order to solve the problem,the dynamic equation of the stator is solved with the structural perturbation theory,then a method is found by resolving the equation,thus adjusting the two modal frequencies into the same one.A test is made with a TRUM-60 made in Research Center of Ultrasonic Motors at Nanjing University of Aeronautics & Astronautics,in which the stator is cut at the appropriate position according to the ANSYS software,and the difference of the two modal frequencies of the stator is changed as 0.04 kHz from 0.42 kHz by the PCV-Z-040-F polytec scanning vibrometer.The result shows that the method is effective for adjusting two modal frequencies of ultrasonic motor stator into coincidence.