纯滑动椭圆接触条件下急停对弹流润滑表面凹陷现象的影响

Effect of a Sudden Stop on the Variation of EHL Surface Dimple Phenomenon under a Simple Sliding Motion in Elliptical Contact

在光干涉滚子-盘试验机上,研究在纯滑动椭圆接触条件下急停对弹流润滑表面凹陷现象的影响,通过改变载荷与速度的大小,观察"温度-黏度楔"凹陷油膜在急停过程中向挤压凹陷油膜的转化情况,并使用双光干涉图像处理软件对油膜中截面膜厚进行测量。实验结果表明:载荷增加时,"温度-黏度楔"凹陷出现的时间与凹陷到达接触区中心的时间均缩短;当速度不同时,急停过程中"温度-黏度楔"凹陷的产生时间不同,但都会向接触区中心移动;随稳态速度的增加,在速度急剧降低为0的阶段,初始油膜厚度高,油膜厚度下降较快;在速度为0的恒载荷纯挤压阶段,油膜厚度下降较慢。

The effect of a sudden stop on the variation of surface dimple phenomenon of elastohydrodynamic lubrication( EHL) in elliptical contact under simple sliding motion was studied on a roller-disk test rig using optical interferometric technique with the spherical steel roller fixed in a lower holder.By changing the entraining velocity and load,the transition of a "temperature-viscosity wedge"dimple into a squeezed entrapment of oil film by a sudden stop was investigated,and the pictures were measured using a dichromatic interference intensity modulation( DIIM) software to obtain the mid-section film thickness.The experimental results show that as the load increases,the occurrence of the "temperature-viscosity wedge"dimple is earlier and the time when the dimple reaches the center of the contact zone become shorter. When the speed is different,the time of the occurrence of "temperature-viscosity wedge"dimple during a sudden stop is different,but the dimples all move to the center of the contact area.As the speed increases,at the sudden stop stage with the rapid change of speed,the initial oil film thickness is higher,and the oil film thickness decreases rapidly,while at the zero speed stage,the oil film thickness decreases slowly.