Research on Startup Reliability of Ultrasonic Motors

作为一种在航空航天和武器系统有着广泛用途的新型微电机,超声电机的启动可靠性影响了其进一步的推广应用。该文通过理论分析将影响电机可靠启动的因素定位为定、转子摩擦界面阻力的增加以及定子的非线性振动,其中摩擦界面阻力增加包括摩擦材料嵌入定子槽中以及摩擦材料与定子的粘接。结合仿真分析和实验研究,证明超声电机定子振动的非线性是影响电机可靠启动的根本原因,越靠近共振频率非线性越严重,而定、转子接触界面的粘接以及摩擦材料嵌入定子齿使定子谐振频率升高,也就使原有工作频率更接近共振频率,从而导致电机定频启动困难。最后提出利用定子振动的非线性,采取降频启动的方法,可有效提高电机启动可靠性,为超声电机的推广应用打下良好基础。

Though ultrasonic motors are extensively used in aerospace and weapon systems as a new kind of micro motors, the start-up unreliability problem limits their application. In this paper, firstly, the theoretical analysis indicates that the reliability degrades due to two reasons. First one is the frictional resistance on the contacting surface between the stator and the rotor, which is caused by the frictional material embedded in the stator and the bonding between them. Second one is the nonlinear vibration of the stator.