Occurrence of Wall Slip in Elastohydrodynamic Lubrication Contacts
Occurrence of Wall Slip in Elastohydrodynamic Lubrication Contacts
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DOI：
10.1007/s11249-009-9414-x
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发表时间：
2009-02
影响因子：
3.2
通讯作者：
F. Guo;F. Guo;P. Wong;M. Geng;M. Kaneta
中科院分区：
文献类型：
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作者：
F. Guo;F. Guo;P. Wong;M. Geng;M. Kaneta
初步的实验工作已经进行，以确定在弹性流体动力润滑（EHL）连接的高压聚丁烯的一些边界滑移现象。油的运动是通过在光学弹流润滑试验装置中钢球撞击玻璃块上的油层而容易形成的截留来表示的。在以下条件下研究了撞击后截留物的横向运动：（i）纯滚动，（ii）纯玻璃块滑动（钢球静止）和（iii）纯球滑动（玻璃块静止）。据观察，在纯滚动的夹带油内的接触区域内的卷吸速度，这是相关的弹流理论。在纯玻璃块滑动条件下，截留油芯的速度小于卷吸速度，并且在极端情况下，该芯可以接近静止。在纯滚珠滑动条件下，油芯以大于卷吸速度的速度移动。结果表明，在实验条件下，油/钢球界面比油/玻璃（镀铬）界面能承受更高的剪切应力，后者界面存在相对滑动的边界滑移。此外，滑移量随着压力的增加而增加。这些实验提供了壁面滑移存在的证据，壁面滑移导致了异常的弹流油膜轮廓，其特征在于如前所述的入口凹坑。
Preliminary experimental work has been carried out to identify some of the boundary slip phenomena of highly pressurised polybutenes in an elastohydrodynamic lubrication (EHL) conjunction. The movement of the oil is signified using an entrapment that can be readily formed by the impact of a steel ball against a layer of oil on a glass block in an optical EHL test apparatus. The post-impact lateral movement of the entrapment was investigated under the conditions: (i) pure rolling, (ii) pure glass block sliding (steel ball stationary) and (iii) pure ball sliding (glass block stationary). It was observed that under pure rolling the entrapped oil travels within the contact region at the entrainment speed, which is correlated with EHL theory. Under pure glass block sliding conditions, the speed of the entrapped oil core is less than the entrainment speed, and in the extreme cases, this core can be nearly stationary. Under pure ball sliding conditions, the oil core moves at a speed greater than the entrainment speed. The observation indicates that the oil/steel ball interface can sustain higher shear stress than the oil/glass (chromium coated) interface and there is a boundary slip in terms of relative sliding at the latter interface under the experimental conditions. Furthermore, the amount of slip increases with an increase in the pressure. These experiments provide evidence of the existence of wall slippage, which leads to the abnormal EHL film profile characterised with an inlet dimple as reported earlier.