Because of the temperature rising of USM, load changes, and vicinal surrounding changes and so on, the resonant frequency will shift and impedance is not matching, leading to working stability drop.

• 由于超声波电机的温升、负载变化及周围环境变化等原因，使电机的谐振频率发生漂移及匹配电感选择不合适，这将影响超声波电机运行的稳定性。