超声波马达的真空和温度特性研究

研究了超声波马达在非常状态下的驱动行为,选取了5种工程塑料作为转子摩擦材料,利用真空试验机和自制的与其相匹配的超声波马达模拟试验台,采用对比试验方法,研究了接触预紧力、真空度和环境温度等对行波型超声波马达的驱动特性的影响。结果表明,随着预紧力和真空度的增加,马达的堵转力矩增加而空载转速下降;随着环境温度的增加马达的空载转速下降。运用声学理论分析了真空度对接触状态的影响,得出声悬浮作用使定子和转子的动态接触力减小的结论。在真空状态下,超声波马达的堵转力矩比常态下提高的主要原因是声悬浮作用降低引起定子和转子的动态接触力增加所致。

Performance of ultrasonic motor under vacuum and high temperature condition

The performance of ultrasonic motor under abnormal conditions are researched, with five kinds of engineering plastics chosen as the rotor friction materials of traveling wave ultrasonic motor (TWUSM). By means of contrast test methods, effects of pre-load,degree of vacuum and surrounding temperature on friction driving properties of TWUSM are studied by using vacuum equipment and simulative TWUSM tester suitable. The results show that stalling torque increases and no load speed decreases with the increase of the pre-load and degree of vacuum. The no load speed decreases with the increase of surrounding temperature. Effects of degree of vacuum on contact states are analyzed by acoustics theory. The conclusion is that action of acoustic levitation makes dynamic contact force between stator and rotor reduce. The major reason the stalling torque in vacuum is higher than that in normal is that the effects of acoustic levitation decrease and the dynamic contact force increases.