可倾瓦径向滑动轴承完整动特性系数的分析模型

基于可倾瓦径向滑动轴承瓦块的扰动特性,提出了计算轴承完整动力系数的数学解析模型。在由单块瓦和轴颈构成的子系统上建立局部动坐标参考系,全局广义位移向量可以通过简练的步骤转换为局部动坐标系下轴颈的位移向量,利用求解固定瓦轴承动力特性的方法求得的局部动坐标系下的油膜力又可以精确地转换为全局坐标系下的表达形式,全局坐标系下的油膜力向量关于广义位移和广义速度的Jocabian矩阵形成轴承的完整动力特性系数;利用Newton-Raphson方法同时求解瓦块和轴颈在给定的静态载荷下的平衡位置,其中所需用到的系数矩阵恰好为轴承油膜力关于广义位移的Jocabian矩阵的负值,在得到平衡位置的同时可以获得轴承完整的刚度和阻尼矩阵。数值算例证明了此方法的有效性。

An analysis method of full dynamic coefficients of a tilting-pad journal bearing

A mathematical model is presented for analyzing the dynamic characteristics of a tilting-pad bearing.This model gives very concise expressions of the full dynamic coefficient matrix of a tilting-pad bearing.The global generalized coordinates associated with degrees of freedom including both journal and each pad are exactly transformed to the journal coordinates relative to the local pad coordinate system(a moving system).Furthermore,the film forces associated with local moving system are transformed to the global generalized forces.Derivatives of the generalized forces give the Jacobian matrices with respect to displacements and velocities of all generalized coordinates.Then the Jacobian matrix with respect to displacements is used to find the equilibrium position of the journal and each pad at a given static load by Newton-Raphson method.The negative Jacobian matrices at equilibrium position are just the full dynamic coefficient matrices.Numerical examples show that the method works satisfactorily.