双跨转子-轴承系统裂纹-碰摩故障的非线性响应研究

分析了带有裂纹-碰摩故障的具有三轴承支承的双跨弹性转子系统的复杂非线性运动。在同时考虑轴承油膜力和碰摩发生时转静件间的相对速度对非线性摩擦力的影响基础上,构造了双跨裂纹-碰摩弹性转子-轴承系统动力学模型,并对系统裂纹、碰摩及其耦合故障对系统非线性动力学响应的影响进行了数值仿真研究。单一裂纹故障时系统响应在超临界转速区有短暂的混沌运动;单一碰摩故障时系统响应在亚临界转速区有拟周期运动出现;裂纹-碰摩耦合故障时在超临界转速区有较大范围的周期4运动区间,小裂纹对系统非线性特性的影响不明显。研究结果为转子-轴承系统故障诊断、动态设计和安全运行提供了一定的理论依据和参考。

STUDY ON NONLINEAR RESPONSE OF TWO-SPAN ROTOR-BEARING SYSTEM WITH COUPLING FAULTS OF CRACK AND RUB-IMPACT

The complex non-linear responses analyzed are of a two-span elastic rotor-beating system with coupling faults of crack and rub-impact supported on three plain journal bearings. A dynamic model of the rotor-bearing system is established considering the oil film force and the nonlinear friction force. The nonlinear dynamics behaviors that induced by crack, rub-impact and coupling faults are numerically studied. Chaos motion appears within the super-critical speed range in the cracked rotor-bearing system, quasi-periodic motion within the sub-critical speed range in the rub-impact rotor-bearing system. Period-4 motion appears within the super-critical speed range in coupling faults of crack and rub-impact system. The influence on the nonlinear characteristics of the system is not clear when the crack is small. The results may bring up theoretical references for fault diagnoses, dynamic design, and security running to rotor-bearing system.