有限长滑动轴承非线性油膜力的近似解法

本文中提出了一种求解有限长径向滑动轴承非线性油膜力的近似解析方法.在滑动轴承-转子系统非线性动力行为分析中,油膜力计算模型通常采用"π"油膜假设,但是,实际工况中油膜的存在区域并非是"π"区域,运行时油膜中出现气穴,破裂成条纹状(即具有Reynolds边界条件).本文中的近似解析方法采用Reynolds边界条件,基于变分原理,运用分离变量法求解油膜的压力分布,其中油膜压力的周向分离函数通过无限长轴承的油膜压力分布获得,油膜的破裂终止位置角通过连续条件确定,轴向分离函数运用变分原理并结合周向函数求得.计算结果表明:本文中提出的方法和有限元方法的结果吻合得很好.在此基础上,分析了一些轴承参数对油膜压力分布的影响.

An Approximate Solution Method for Nonlinear Oil Film Forces of Finite Length Journal Sliding Bearing

An approximate analytical method is proposed for calculating nonlinear oil film forces of finite length journal sliding bearing.The dynamic "π" oil film assumption is usually taken to determine nonlinear oil film forces in the dynamic analysis of hydrodynamic journal bearing-rotor system.In practice,oil film usually ruptures,and then cavitation arises,cavitaion of oil film results in Reynolds boundary conditions,i.e.,oil film field is not "π" zone in the lubrication.In this paper,based on the variational principle,the method of separation of variables was employed to obtain the pressure distribution with Reynolds boundary conditions.The pressure distribution of infinite long journal bearing model was taken as a circumferential separable function of the pressure distribution.The termination positions of oil film in circumferential direction were determined by using the continuity condition.The axial separable function of the pressure distribution was obtained by the variational principle and the circumferential separable function.The results calculated by the proposed method were in good agreement with the oil film forces by the finite element method.Meanwhile,the influence of the bearing parameters on the pressure distribution was also analyzed.