微织构对径向滑动轴承承载能力的影响机理

Influence mechanism of micro texture on load carrying capacity of journal bearing

为了揭示表面微织构对径向滑动轴承承载能力的影响规律及机理,以指导滑动轴承微织构的优化设计,在考虑空化效应和紊流影响的前提下,采用基于N-S方程的CFD技术建立了三维织构化滑动轴承的仿真分析模型,分析了微织构分布位置、形状和尺寸对轴承承载能力的影响,并从微织构对油膜压力的影响这一层面,探讨了微织构对滑动轴承承载能力的影响机理.分析表明:微织构的存在一方面具有增加油膜厚度、降低织构区油膜压力的负面作用,另一方面也具有推迟油膜破裂、扩大油膜承载区的积极作用,这两方面的共同作用形成了微织构对滑动轴承承载能力的影响机制;微织构对轴承承载能力的双重作用,导致只有在轴承主要承载区附近布置微织构方可提升承载能力,且当微织构布置于有利于提升滑动轴承性能的位置时,存在一个最优的织构轴向分布率、密度、宽度和深度,使得滑动轴承的承载能力最大.

In order to reveal the influence and mechanism of surface textures on the load carrying ca- pacity of journal bearing for texture optimization design, the three-dimensional models of journal bear- ing with textures were simulated with CFD method based on Navier Stokes equation, considering cavi- tation and turbulence effect. The influence of textures locations, shapes and geometries on the load carrying capacity of journal bearing were analysed, and the influence mechanism was studied based on the influence of textures on the oil-film pressure. The results show that, the textures can increase the film thickness and decrease the oil-film pressure, which may decrease the load carrying capacity of journal bearings. And the textures can also delay the rupture of the film and expand the load carrying region, which may increase the load carrying capacity. The double effect of textures on the load carry- ing capacity of journal bearings is the reason why the textures distributed in load carrying region can improve the load carrying capacity of journal bearings, and there is an optimal combination of axial distribution rate, density, width and depth of textures for the journal bearings to reach the largest load carrying capacity.