非稳态油膜力对转子系统盘轴松动故障的影响研究  

Effects of unsteady oil film force on rotor system with loose disk and shaft

作　　者：刘杰[1] 李志农[1] 卢文秀[2] LIU Jie;LI Zhinong;LU Wenxiu(MOE Key Lab of Nondestructive Testing Technology,Nanchang Hangkong University,Nanchang 330063,China;Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]南昌航空大学无损检测技术教育部重点实验室,南昌330063 [2]清华大学机械工程系,北京100084

出　　处：《振动与冲击》2019年第17期268-275,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51675258; 51261024; 51075372);机械传动国家重点实验室开放基金(SKLMT-KFKT-201514)

摘　　要：当盘轴松动时,油膜涡动会对转轴的运动轨迹造成影响,从而影响转盘和转轴的碰摩,转盘和转轴的碰摩又会对油膜涡动造成很大扰动,非稳态油膜力对转子系统盘轴松动故障的影响具有重要研究价值。利用Hertz接触理论和非稳态非线性油膜力建立了盘轴松动故障转子-轴承系统的运动微分方程,利用四阶龙格-库塔法对其进行数值仿真,并经过实验验证。讨论了非稳态油膜力对转盘转动状态的影响及油膜间隙对转子系统振动特性的影响。研究结果表明:转盘无量纲转速有高低两种状态,不考虑油膜力的转子系统转盘转速进入高转速状态时,转轴转速低于考虑油膜力的转子系统;随油膜间隙增大,轴承端的运动轨迹经历类似周期运动状态、混乱状态、类似周期运动状态,运动轨迹的形状变得越来越细长,转轴中心的运动轨迹像一个不断旋转的扇形,无明显变化规律,系统的频率成分基本无变化,但各频率成分的幅值会有不同的变化。研究成果对盘轴松动故障的建模及动力学特性研究具有重要的参考价值。When disk and shaft of a rotor system are loose,oil whirl can affect shaft motion trajectory,and lead to rubbing between disk and shaft,this rubbing can cause large disturbance to oil whirl,so study on effects of unsteady oil film force on rotor system with loose disk and shaft is valuable.Here,dynamic differential equations of a rotor-bearing system with loose disk and shaft were established with Hertz impact-contact theory and unsteady and nonlinear oil film force.The fourth-order Runge-Kutta method was used to solve these equations,and the numerical simulation results were verified with tests.The effects of unsteady oil film force on disk rotating state and effects of oil film clearance on vibration characteristics of the rotor system were discussed.The results showed that disk dimensionless rotating speed has two states of high rotating speed and low one;when the rotor system does not consider oil film force and its disk rotating speed enters high speed state,its shaft rotating speed is lower than that of the rotor system considering oil film force;with increase in oil film gap,bearing center motion trajectory undergoes quasi-periodic motion state,chaos one and quasi-periodic one,and its shape becomes more and more slender;shaft center motion trajectory is like a rotating sector without obvious variation law,frequency components of the rotor system are basically unchanged,but their amplitudes have different changes;the study results provide an important reference for modeling of rotor systems with loose disk and shaft and studying their dynamic characteristics.

关 键 词：盘轴松动 非线性振动 HERTZ接触 故障诊断 非稳态油膜力 

分 类 号：TH113.1[机械工程—机械设计及理论] O322[理学—一般力学与力学基础]