基于几何条件的可倾瓦轴承油膜边界条件判定方法

Analysis of Oil Film Boundary Conditions of Tilting Pad Bearing Based on a Geometrical Model

针对可倾瓦轴承的雷诺方程,基于瓦块几何模型获得各个瓦块的边界条件,利用轴心、各瓦块中心与轴承之间的耦合关系,采用有限差分法计算分析油膜压力的分布。理论推导表明,瓦块的位置仅由瓦块预置参数、轴心的位置决定;数值结果表明,轴承的承载力随偏心率增大呈增大趋势。结合具体算例看出,当轴颈位置确定时,可确定各瓦块实际偏位角和偏心率,进而可对各瓦块方程分别进行求解。建立一种可行的边界条件确定法则,为可倾瓦轴承的建模提供了理论依据。

The geometric model describing the boundary conditions of tilting-pad bearings was studied. The coupling effect of the shaft axis, pad center and bearing center locations was analyzed to solve the Reynolds equation and analyze the film pressure distribution by means of finite difference method. Theoretical derivation indicates that the position of each pad is determined by preset parameters and the location of shaft center only. Numerical results show that the bearing capacity increases with the increase of the eccentricity ratio. A case study demonstrates that once the shaft center location is determined, the angle of displacement and the eccentricity ratio can be determined correspondingly, thus the dynamic equation of each pad can be solved. The feasibility law of the boundary conditions has been established, which provides a theoretical basis for the modeling of tilting pad bearings.