对一种基于弯曲振动模式压电超声马达中的突出问题──摩擦、噪声及其对马达性能的影响进行了研究．考察了马达转子摩擦材料、转子与定子之间的压力、工作频率、电路匹配等因素对马达运转噪声、转速力矩输出和运转平稳性等的影响．实验结果揭示，马达运转噪声除了与摩擦材料有密切关系外，还与其它诸多因素有关．实验中还发现，改变定子与转子之间的压力，不仅马达噪声大小会发生变化，而且噪声的主频成分也会改变． A prominent problem in piezoelectric ultrasonic motor based on flexural vibration mode - friction, noise and its influence on motor performance was studied. The influences of the motor rotor friction material, the pressure between the rotor and the stator, the operating frequency and the circuit matching on the running noise, torque output and running stability of the motor were investigated. The experimental results reveal that the operating noise of the motor is closely related to friction materials, but also to many other factors. Experiments also found that changing the pressure between the stator and the rotor not only changes the size of the motor noise but also changes the dominant frequency component of the noise.