多点接触乏油弹流润滑模型及试验研究

Study on Starved Oil Elastohydrodynamic Lubrication Model and Experiments of Multi-point Contacts

为探讨多点接触乏油弹流润滑机制,基于球与滚道接触区域的排油和补油平衡,建立适用于不同润滑状态的油膜厚度计算模型,可以计算从充分供油、乏油到干涸乏油的中心膜厚以及油膜不平衡时中心膜厚随滚动次数的衰减。利用自制的球-盘接触光干涉弹流试验装置,通过安装双镜筒同时获取相邻球的油膜图像,研究多点接触中相邻球的轨道重合和不重合时前球尾迹对后球油膜图像和中心膜厚的影响。结果表明:乏油润滑条件下,前后球的轨道不重合时轨道之间可相互补油;前后球的轨道重合时,在给定供油条件下,随着滚动线速度增加,入口弯液面逐渐靠近接触区域,中心油膜厚度增加,与相同工况下乏油润滑模型计算的膜厚对比吻合较好,验证了所建乏油润滑模型的正确性。

In order to explore the starved-oil elastohydrodynamic lubrication(EHL)mechanism of multi-point contacts,a model for calculating the film thickness under different lubrication states was established based on the balance of oil replenishment and extrusion in the contact area of ball and raceway.It can calculate the center film thickness and the decrease of film thickness with the number of rolling times from fully flooded,starved and parched lubrication.The self-made ball-on-disc light interference EHL test rig was used to simultaneously acquire the oil film images of the adjacent balls by installing the double lens barrel.The effects of the track of the previous ball on the oil film image and center film thickness of the following ball were studied under the adjacent orbits coincide or do not coincide.The results show that under the starved-oil lubrication condition,the tracks can complement oil each other when the orbits of the previous ball and the latter ball do not coincide.When the orbits of the adjacent balls coincide,under the given oil supply conditions,as the rolling velocity increases,the inlet meniscus gradually approaches the contact area and the center film thickness is increased.The result of film thickness is consistent with that calculated by the starved-oil lubrication model under the same working conditions,which verifies the correctness of the model.