可倾瓦滑动轴承系统线性稳定性分析

提出可倾瓦轴承系统解析模型并对其进行线性稳定性分析。采用Newton-Raphson和pad assembly这两种方法,可获得系统完整的动力特性系数。基于这些动力特性系数,建立系统的运动微分方程并进行复特征值分析,易求得用来检验系统稳定性的轴瓦临界质量和系统阻尼比。结果表明:预负荷、转速及支点位置均对可倾瓦轴承系统的稳定性有着较大的影响,合理选取这些参数有助于提高系统的稳定临界值。

LINEAR STABILITY ANALYSIS OF TILTING-PAD JOURNAL BEARING SYSTEM

A mathematical model is presented to study the linear stability of tilting-pad journal bearing system.By employing the Newton-Raphson method and the pad assembly technique,the full dynamic coefficients involving the shaft degrees of freedom as well as the pad degrees of freedom are obtained.Based on these dynamic coefficients,the perturbation equations including self-excited motion of the rotor and rotational motion of the pads are established.Through analyzing complex eigenvalues depending on these differential equations,it is easy to determine the pad critical mass and damping ratio used to exam the stability of the system.The computing results show that some factors,such as preload coefficient,pivot position and rotor speed,significantly affect the stability of tilting-pad journal bearing system.Reasonable selection of the parameter values is helpful to enhance the stability threshold of the system.