The oil film in a closing gap
The oil film in a closing gap
复制标题
DOI：
10.1098/rspa.1962.0064
复制
发表时间：
1960-06
期刊：
影响因子：
--
通讯作者：
H. Christensen
中科院分区：
文献类型：
--
作者：
H. Christensen
本文给出了两圆柱体间有润滑膜时法向接近的弹性流体动力学问题的一种解法。对于常粘性和刚性材料的特殊情况，以及粘性随压力变化的情况，都找到了解析解。在电子计算机的帮助下，通过使用迭代数值处理，解决了具有恒定或压力依赖粘度的物体的弹性变形的更一般的情况。结果发现，一个非常高的压力可能会开发在润滑油膜在有限的气缸分离。随着膜厚的进一步减小，最大压力的值减小，并且随着膜厚接近零，压力分布收敛到赫兹干接触形式。对于施加到气缸上的给定载荷，所达到的最大压力值在很大程度上取决于参数α E的值，即压力粘度系数和弹性系统的等效杨氏模量的乘积。此外，一旦压力达到足够高的值，它对负载的增加变得极其敏感;负载的小幅增加将导致最大压力的大幅增加。进行了一些实验，以检查一些理论预测。在这些实验中，一个加载钢球被允许接近各种材料的抛光表面，其表面被润滑膜覆盖，然后测量在表面产生的塑性变形。这些试验清楚地表明了润滑剂的影响，在每种情况下，润滑剂的压痕深度都明显大于赫兹干接触冲击下产生的相应压痕深度。实验结果表明，最大压力和olE值之间的相关性和它的敏感性，在高压下的负载增加的理论预测。
This paper presents a solution to the elasto-hydrodynamic problem of normal approach of two cylindrical bodies separated by a lubricating film. Analytic solutions are found for the special cases of constant viscosity and rigid material and also for pressure-dependent viscosity. The more general case accounting for elastic deformation of the bodies with constant or pressure dependent viscosity was solved by using an iterative numerical process with the help of an electronic computer. It is found that a very high pressure may be developed in the lubricant film at a finite separation of the cylinders. As the film thickness is further reduced, the value of the maximum pressure decreases and as the film thickness approaches zero, the pressure distribution converges to the Hertzian dry contact form. For a given load applied to the cylinders, the value of the maximum pressure reached depends to a large extent upon the value of the parameter ocE, i.e. the product of the pressure coefficient of viscosity and the equivalent Young’s modulus of the elastic system. Also, once the pressure has reached a sufficiently high value it becomes extremely sensitive to an increase in load; a small increase in load will produce a large increase in maximum pressure. A number of experiments were performed in order to check some of the theoretical predictions made. In these experiments a loaded steel ball was allowed to approach the polished surface of various materials whose surfaces were covered by a lubricant film, and the plastic deformations produced in the surface were then measured. These tests showed clearly the influence of the lubricant in that in every case the depth of the impressions with lubricant was significantly larger than the corresponding ones produced under Hertzian, dry contact impacts. The experimental results indicate a correlation between maximum pressure and the value of olE and its sensitivity to increase in load at high pressure as predicted by the theory.