针对高转速下滑动轴承易出现高阶油膜失稳的问题,建立考虑陀螺效应的单跨双盘转子系统集中质量模型,其中左、右轴承分别采用弹簧-阻尼模型和短轴承非线性油膜力模型。考虑两圆盘偏心反相位情况,通过轴心轨迹、时域波形、频谱图和三维谱图,分析转子系统在升速过程中出现的油膜失稳规律及产生的复杂非线性动力学特性。通过搭建模型试验台,对仿真结果进行验证。理论和试验结果均表明:在较高转速下系统会同时出现前两阶油膜振荡,油膜振荡会激起与转频和前两阶振荡频率有关的组合频率成分,且1阶和2阶油膜振荡共存时存在能量转换现象。
Aiming at the oil-film instability problem of the sliding bearing at a high speed, a single span rotor system with two discs is studied. Considering the gyroscopic coupling effect, a lumped mass model of the rotor system is established where the left and the fight bearings are simulated by a spring-damping model and a no-linear oil-film force model of the short bearing, respectively. Considering the eccentricities of two discs in opposite phases, the oil-film instability rule and the complicated nonlinear dynamic characteristics of the rotor system are analyzed by the rotor orbit, time domain waveform, amplitude spectrum and spectrum cascade. Experiments are performed by using a test rig to verity the simulation results. Theoretical analysis and experimental results all show that the first two oil whip will occur simultaneously at higher rotating speeds, oil-film instability can excite the complicated combination frequency components of the first and second oil-whip frequencies and the energy can be transformed between the first oil whip and the second one.