考虑表面粗糙度和热效应的线接触非牛顿混合润滑分析

A Non-Newtonian Mixed EHL Model of Line Contact Considering Asperity and Thermal Effect

为了研究表面粗糙度及热效应对非牛顿混合润滑的影响,基于平均流量模型,考虑表面粗糙度以及热效应,建立线接触非牛顿混合润滑模型。研究表面粗糙度对膜厚、膜厚比、平均摩擦因数、载荷比以及温度分布的影响,并与等温解进行比较。结果表明:随着表面粗糙度的增大,油膜温度逐渐升高,尤其是出口区与入口区的温升最为显著,且油膜温升越大,载荷比及平均摩擦因数越大,膜厚比越小;与等温解相比,热解的膜厚比及平均摩擦因数小,载荷比大;等温与热条件相比,中心膜厚与最小膜厚随表面粗糙度的变化趋势差异显著,说明热效应对混合润滑的影响不可忽略。

To investigate the influence of surface roughness and thermal effect on non-Newtonian mixed lubrication,based on the average flow model,considering the surface roughness and thermal effect,a non-Newtonian mixed lubrication model of line contact was established.The effects of surface roughness on the film thickness,the film thickness ratio,the average friction coefficient,the load ratio and the temperature distribution were studied,and the thermal and isothermal solution was compared.The results show that,with the increase of surface roughness,the temperature of oil film is increased gradually,especially in the exit and entrance areas,and the higher the oil film temperature rise,the larger the load ratio and the average friction coefficient,the smaller the film thickness ratio.Compared with the isothermal solution,the film thickness ratio and the average friction coefficient of thermal solution are smaller,and the load ratio is greater.The difference of variation in the central and minimum film thickness versus the surface roughness between the isothermal and thermal conditions is significant.Therefore,thermal effect in mixed lubrication can not be neglected.