轴向往复运动下微槽轴承混合润滑数值模型

Numerical model of mixed lubrication for microgroove bearing considering axial reciprocating motion

建立了考虑轴向往复运动以及轴颈偏斜的人字槽滑动轴承混合润滑(Mixed-EHL)数值模型。通过瞬态平均雷诺方程求解了考虑表面粗糙度效应的油膜压力,通过影响系数法求得轴瓦内表面弹性变形,而界面接触压力则由Lee-Ren粗糙峰接触模型求得。通过数值模拟得到了承载力、接触载荷比、摩擦因数等参数随时间的变化规律,并研究了往复运动间距及偏斜角对混合润滑性能的影响。研究表明:油膜力与轴向速度呈同相变化,接触载荷与轴向速度呈反相变化;随运动间距的增大,滑动轴承在反向运动历程中的承载能力和润滑性能显著降低;偏斜角增大会降低轴承的混合润滑性能以及承载能力。

A numerical model was developed to investigate the mixed lubrication performance of herringbone grooved journal bearing when axial reciprocating motion and journal misalignment were considered.The oil film pressure considering the roughness effect can be obtained by transient average Reynolds equation.The elastic deformation can be obtained through influence function method,and the contact pressure can be simulated by Lee-Ren asperity contact model.The variation of oil-film force,contact load ratio,and friction coefficient with time were investigated by numerical simulation,and the effect of axial movement amplitude and misalignment angle on mixed lubrication performance were also studied.The research suggests that the oil-film force is corresponding over axial velocity,and the contact pressure shows inverse variation with axial velocity.Besides,the increase of axial movement amplitude in negative movement state will result in a significant reduction in load capacity and lubrication performance of journal bearing.The research also shows that the load capacity and lubrication performance of journal bearing decrease with the increase in misalignment angle.