转子通过临界转速时碰摩热效应对振动特性的影响

转子-定子之间的碰撞与摩擦是一个危害性很大的现象，也是十分复杂的物理过程．这一过程消耗的机械能，绝大部分生成热能．尽管每次碰撞与摩擦的热效应对转子影响很小，但是由于热量的散失相对于转子的振动来说是一个较慢的过程，一旦出现较频繁的碰摩，热载荷的累积效应是不容忽视的．转子通过临界转速时，如果振动幅度过大就会导致碰摩．碰撞引起转子振动相位的变化，而碰摩产生的热挠曲将会延长碰摩过程．在建立了转子与定子之间的弹性碰撞接触、摩擦和热传导的简化模型的基础上，应用数值方法分析了转子通过临界转速时上述碰摩过程的一个简单例子．

The effect of rub-impact thermal effects on vibration characteristics of a rotor passing through critical speed

The collision and friction between rotor and stator is a complex physics process, in which most of the mechanical energy caused by collision and friction is converted into heat. Even though each collision does not affect the rotor significantly,and the decreasing of temperature takes a longer time compared with the vibration period of rotor, the accumulated thermal effects must be taken into account. When the rotor passes through the critical speed, rub-impacts are liable to happen because of the larger vibration amplitude. Collisions cause the variation of vibration phase, and the corresponding thermal bending prolongs the process of collisions. In this paper,a simplified model was set up to describe the elastic collision contact and friction between rotor and stator, and then an example was numerically computed and analyzed in order to examine the effect of rub-impact thermal effects on the vibration characteristics of a rotor passing the critical speed.