ESTABLISHMENT OF THERMAL ELASTOHYDRODYNAMIC LUBRlCATION

当在集中滚动/滑动接触中接触材料的导热率存在差异时，具有低导热率的材料的表面温度高于具有高导热率的材料的表面温度。因此，润滑油的温度和粘度在整个油膜上变化。特别地，当具有低热导率的材料的表面速度大于具有高热导率的材料的表面速度时，产生额外的压力峰值，因此通过温度-粘度楔作用形成厚膜或凹坑。油膜压力峰值对凹坑的形成起着重要作用，多凹坑是主压力峰值和压力尖峰共同作用的结果。实验结果可以通过考虑三维能量平衡和非牛顿流体的流动行为得到更详细的解释。其他重要结果获得 ...更多信息 艾德的研究结果如下：1.在椭圆形接触中，当油液卷吸矢量沿着接触椭圆的短主轴方向时，形成的凹坑是稳定的，而当油液卷吸矢量沿着接触椭圆的长主轴方向时，形成的凹坑是不稳定的。卷吸角的变化对温度分布有重要影响，但对最高温度影响不大。当滑滚比足够小时，牵引系数受压缩加热和非牛顿流动行为的控制。粘性加热对牵引系数的影响随着滑滚比的增大而增大。3.在接触材料具有相同热导率的情况下，热导率越大，牵引系数和总膜厚越大。当接触材料的热性能彼此不同时，具有高导热率的表面的速度应大于具有低导热率的表面的速度，以防止滚动接触疲劳。少

When there is a difference in thermal conductivity of the contact materials in concentrated rolling/sliding contacts, the surface temperature of the material having a low thermal conductivity is higher than that of the material having a high thermal conductivity. Consequently, the temperature and viscosity of the lubricating oil vary across the oil film. In particular, when the surface velocity of the material having a low thermal conductivity is larger than that of the material having a high thermal conductivity, an extra pressure peak is generated, and thus a thick film or a dimple is formed by the temperature-viscosity wedge action. The film pressure peaks play an important role in the formation of dimple, and multi-dimples are caused by the cooperated interaction of the main pressure peak and pressure spike. The experimental results can be explained in more detail by considering three dimensional energy balance and non-Newtonian oil flow behavior. The other important results obtain … More ed are summarized as follows :1.In elliptical contacts, when the oil entrainment vector is directed along the minor principal axis of the contact ellipse, the dimples formed are stable, but when the entrainment vector is directed along the major principal axis, the dimples formed are unstable. The change of the entrainment angle plays an important role in the temperature distribution but does not influence the maximum temperature. The traction coefficient hardly depends on the entrainment angle.2.When the slide-roll ratio is small enough, the traction coefficient is controls by the compressive heating and non-Newtonian flow behavior. The effect of the viscous heating on the traction coefficient increases with increasing in the slide-roll ratio.3.In cases where the contacting materials have the same thermal conductivity, a larger thermal conductivity leads to a larger traction coefficient and overall film thickness. When the thermal properties of the contacting materials differ each other, the velocity of the surface having a high thermal conductivity should be larger than that having a low thermal conductivity, in order to prevent the rolling contact, fatigue. Less