松动-碰摩耦合故障转子系统振动特性分析

Vibration Characteristic of a Rotor-Bearing System with Pedestal Looseness and Rub-Impact

针对动态油膜力下带有支座松动 碰摩耦合故障的转子 轴承系统的非线性动力学模型,采用数值模拟等方 法,考察其随转速比变化及改变最大松动间隙值时发生松动和碰摩故障的分岔与混沌特性,并分别与相同参数条件 下带有支座松动故障的转子系统和碰摩故障转子系统进行比较,得到如下结论:该耦合故障系统中碰摩与松动故障 主要发生在主共振区、油膜振荡区及转速比大于3.4的转速范围内,发生碰摩故障时系统运动多为混沌运动;随着 松动最大间隙值的减小,碰摩的转速范围越来越大,而发生松动的转速范围越来越小;两种故障的产生相对独立。

Simulations show that the bifurcation and chaotic behavior of the looseness-rubbing rotor system vary with the rotating angular speed under different maximum loosed inter-space values by using unsteady oil film forces based on the nonlinear dynamic model of a rotor-bearing system with pedestal looseness and rub-impact. The simulation results were compared with those of looseness rotor-bearing system and those of rub-impact rotor-bearing system separately with the same parameters. The comparison results show that the rubbing and looseness mainly occurred within the critical speed region, oil whip region, and the high speed rigion such as Ω>3.4. The chaotic motion can be observed when the rub -impact fault took place. As the maximum loosed inter-space value decreases, the rubbing speed region becomes wider and the loosed speed region becomes narrower than those when the maximum loosed inter-space value is large. The two faults are independent of each other.