带柔性静子部件的轴承共腔涡轴发动机碰摩特征

Rub-impact characteristics of bearing co-cavity turboshaft engine with flexible static parts

为研究具有轴承共腔结构的涡轴发动机在发生转、静子碰摩时转子-机匣系统动力学特征及机匣振动响应特征,建立了简化的转子-机匣碰摩动力学模型,并通过Runge-Kutta法进行求解。仿真结果表明:当发生转、静子碰摩时,机匣响应频谱中出现转子高倍频及其组合频率成分,高倍频成分幅值随碰摩程度加重而增大。对该型发动机进行台架试车实验,验证了该模型和结论的有效性。并利用不具有该结构的某第二代涡轴发动机试车的碰摩数据,进一步验证了带柔性静子部件的轴承共腔发动机中双转子间存在运动耦合,为涡轴发动机振动监控与故障诊断提供一定的理论依据。

In order to study the dynamic characteristics of the rotor system and the vibration response characteristics of the casing for the rotor and stator rub of bearing co-cavity structure,a simplified rotor-casing impact dynamics model was established and solved by the Runge-Kutta method.Simulation results showed that when the rotor and stator were rubbed,the frequency doubling and combined frequency of the rotor appeared in the casing response spectrum.Meanwhile,the amplitude of frequency doubling component increased with the degree of rubbing.The bench experiment of this engine was carried out to verify the validity of the model and conclusion.And it was further verified that there was motion coupling between the two rotors in the bearing co-cavity engine with flexible stator parts by utilizing the rubbing data of a second-generation turboshaft engine experiment without this structure.This work may provide some theoretical basis of the vibration monitoring of the turboshaft engine,and it is also beneficial to the fault diagnosis in the future.