ESTABLISHMENT OF THERMAL ELASTOHYDRODYNAMIC LUBRlCATION

热弹性流体动力润滑的建立

基本信息

批准号：
13450067
负责人：
NISHIKAWA Hiroshi
金额：
$ 9.34万
依托单位：
Kyushu Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

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

当集中滚动/滑动接触时，接触材料的导热系数存在差异时，所考察的导热系数低的材料的表面温度高于导热系数高的材料的表面温度和粘度。特别是，当导热系数低的材料的表面速度大于导热系数高的材料的表面速度时，会产生额外的压力峰值，从而形成厚膜或油膜。酒窝是温度-粘度楔形作用形成的薄膜压力峰值在韧窝的形成中起着重要作用，而多重韧窝是由主压力峰值和压力尖峰的相互作用引起的。实验结果可以得到更多的解释。通过考虑三维能量平衡和非牛顿油流行为，获得的其他重要结果总结如下：1.在椭圆形接触中，当油夹带矢量沿着接触的短主轴定向时。椭圆形时，形成的韧窝是稳定的，但当夹带矢量沿主轴线方向时，形成的韧窝是不稳定的。夹带角的变化对温度分布起着重要作用，但不影响最大温度牵引力。 2.当滑辊比足够小时，牵引系数受压缩加热和非牛顿流动行为控制。粘性加热对牵引力的影响。系数随着滑辊比的增加而增加。3.在接触材料具有相同导热系数的情况下，当接触材料的热性能不同时，导热系数越大，牵引系数和总膜厚度越大。另外，热导率高的表面的速度应大于热导率低的表面，以防止滚动接触疲劳。