缸套表面环槽织构润滑性能数值分析

Numerical Analysis on Lubrication Performance of Surface Ring-Groove Texturing on Cylinder Liner

为了改善缸套-活塞环摩擦副润滑性能,在缸套表面采取了环槽织构措施,通过数值计算的方法,研究了环槽形新型织构的润滑摩擦机理,并对比分析了环槽与圆形凹腔织构润滑性能的差异。结果表明:当活塞环经过环槽织构时,在运动方向上,环槽中心圆柱前槽与后槽分别产生油膜压力较小与较大的动压润滑效应,即环槽能产生二次动压效应;与相同外径的圆形凹腔织构相比,存在一个最佳槽宽能有效改善润滑摩擦性能,在此数值以外,合适的槽宽能使环槽润滑性能较好,相比于圆形凹腔织构,润滑油膜压力分布更为均匀,最小膜厚比增加,摩擦力和摩擦平均有效压力均呈下降趋势,其原因是二次动压效应与面积占有率对环槽影响的叠加中,前者占据了主导地位;过小的槽宽会使得环槽织构润滑效果恶化。

To improve the lubrication performance of the cylinder liner-piston ring, the ring-shaped grooves were textured on the liner surface. Through numerical simulation, the friction and lubrication mechanism of the novel texture was studied, and its lubrication performance was compared with the circle dimple texture. The results show that when the piston ring passes by the ring-shaped grooves along the piston moving direction, twice hydrodynamic effects, the smaller and the larger oil pressure occur at the inlet side and the outlet side of the groove respectively. Compared with the circle dimple with the same diameter, an optimized width of the ring-shaped grooves exists. Furthermore, the well-designed groove can improve the lubrication condition of ring-liner contact because of the thicker oil film and its more homogeneous pressure distribution. As a result, the friction force and the Friction Mean Effective Pressure(FMEP) all decrease. The reason for this is the influence of twice hydrod-ynamic effect and area ratio on the ring groove, and the former occupies the leading position; However, the lubrication condition will deteriorate if the groove width is too small.