织构化滑动轴承混合润滑与磨损耦合数值模型

Numerical Coupled Model of Mixed Lubrication Wear for Textured Journal Bearing

基于统计学模型建立织构化轴承混合润滑与磨损的计算模型,通过生成轴瓦虚拟粗糙表面,分别利用平均流量雷诺方程、K-E弹塑性接触模型、Boussinesq积分、Archard型磨损方程求解油膜压力、粗糙峰接触压力、轴瓦的弹性变形和轴瓦表面磨损量。通过有限差分法和牛顿下山法对模型进行数值模拟,得到不同偏心率下的油膜压力、油膜厚度、轴瓦弹性变形、轴瓦表面粗糙峰接触压力及磨损量,并与其他混合润滑模型进行对比,验证了该模型的有效性。以圆形凹坑织构为例,研究在多种工况下,润滑状态转化以及织构对磨损过程的影响。研究表明:织构可以形成二次润滑,有利于流体润滑;随偏心率增大,进入混合润滑状态后,承载能力、粗糙峰接触载荷迅速增加,摩擦因数出现拐点;在混合润滑状态下,磨损过程前期表面织构会造成轴承承载性能降低和增大磨损,随着滑动轴承进一步磨损,表面织构可以起到减磨作用。

Based on statistical model,the calculation model of hybrid lubrication and wear of textured bearing was established.By generating virtual rough surface of bearing bush,the average flow Reynolds equation,K-E elastic-plastic contact model,Boussinesq integral and Archard wear equation were used to solve oil film pressure,rough peak contact pressure,elastic deformation of bearing bush and shaft,and abrasion on tile surface respectively.The finite difference method and Newton downhill method were used to solve the model of hybrid lubrication and wear,and the oil film pressure,rough peak contact pressure,elastic deformation of bearing bush and shaft,and abrasion on tile surface at different eccentricities were obtained.The calculation results were compared with those of other mixed lubrication models,and the validity of the model was verified.Taking circular pit texture as an example,the effects of lubrication state transformation and texture on wear process under various working conditions were studied.The results show that texture can form secondary lubrication,which is beneficial to fluid lubrication.With the increase of eccentricity,the load-carrying capacity and rough peak contact load are increased rapidly,and the inflection point of friction coefficient appears.In the mixed lubrication state,the surface texture will reduce the load-carrying capacity and increase the wear in the early stage of wear process,while with the further wear of sliding bearings,the surface texture can play a role in reducing wear.