表面划痕对滚子副润滑状态的影响

基于试验中观察到的滚子表面划痕现象,采用数值方法研究了不同供油条件下,划痕对滚子副润滑性能的影响,并与已有试验进行了比较,讨论了划痕长度和深度的影响.结果表明,划痕会影响滚子副的油膜压力和厚度,使得划痕中心油膜压力减小,膜厚增加;同时,划痕边缘处油膜压力增大,膜厚减小.供油层厚度越小,即乏油程度越严重,划痕边缘处的油膜压力及其梯度越大,膜厚越小.划痕越长,划痕越深,划痕中心的油膜压力越低,而膜厚越大.因此,划痕虽增大了滚子副划痕中心的膜厚,降低其压力,但同时增大了划痕附近的压力,减小了膜厚,在乏油条件下尤其如此,因此,划痕会加速滚子副的局部磨损.

Effects of the surface scratch on the lubricating status of roller pairs

Based on the roller surface scratch observed in the experiment,the influence of the scratch on the lubricating performance of the roller pair was investigated under different oil-supply conditions by means of the numerical method.Comparison between the numerical and experimental results was made,and the effects of the scratch length and depth were discussed.Results show that the pressure and thickness of the oil film in the roller pair are influenced by the scratch,and at the centre of the scratch,the pressure decreases and the film thickness increases.Simultaneously,the pressure increases and the film thickness decreases near the scratch edge.The less the thickness of the oil-supply layer,i.e.,the more serious the starvation,the larger the oil pressure and its grades near the scratch edge.The longer and deeper the scratch,the lower the pressure and the larger the film thickness at the center of the scratch.Therefore,the scratch can cause the film thickness to increase and the pressure to decrease at the center of the roller’s scratch,meanwhile,it increases the pressure and decreases the film thickness at the two ends of the scratch,especially in the starved lubricating case.In conclusion,the scratch can accelerate the wear of the roller pair.