The tribological performance of grease lubricated point-contact bearing systems

脂润滑点接触轴承系统的摩擦学性能

• 批准号: 239156-2012
• 负责人: Benabdallah, Habib
• 金额: $ 1.46万
• 依托单位: Royal Military College of Canada
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=594236
• 关键词: tribological; performance; grease; lubricated; point

Lubrication is the introduction of a substance (fluid or solid) between the contact surfaces of moving parts to reduce friction and wear, and to dissipate heat. In a Hydrodynamic regime, ideal conditions can be created through design to develop a convergent wedge of lubricant able to fully support the bearing load while separating completely the mating surfaces. On the other hand, elasto-hydrodynamic (EHL) regime is generated when the load is carried by very small contact area, causing significant surface elastic deformation. Although the pressure distribution along the conjunction and film thickness can be predicted with accuracy, anticipating the traction is problematic, as the rheological properties of the film are difficult to predict, keeping in mind that the pressure may induce a large variation of the viscosity. Grease acts as a sealant to prevent leakage and impede the entrance of corrosive contaminants, and it is a good damping and noise-suppressor medium; it is therefore a very common lubricant. Although grease is used to lubricate more than 80% of at least 20 billion bearings mounted on a large number of mechanical systems, limited knowledge of its behavior, previously thought to be similar to oil, is causing problems of premature failures in applications related to cutting-edge technology. Lubrication using grease is believed to generate starved mixed-EHL, meaning that the film is thinner and thus contact between at least some asperities takes place. Therefore the prediction of the friction in these systems becomes an even more challenging task due to the requirement to combine the traction in a discontinuous film and the component arising from the interaction of the asperities, which are deformed due to the loading and pressure as well as subjected to wear. The aim of this research is to develop and experimentally validate mathematical models for the prediction of friction and lubrication-failure applicable to grease-lubricated starved sliding contact. A successful outcome will definitely constitute a great achievement toward the development of cutting-edge technology and for the production of higher performance bearing-mechanisms, which will generate substantial energy savings and environmental benefits.

润滑是在运动部件的接触面之间引入一种物质（流体或固体），以减少摩擦和磨损，并散发热量。在流体力学条件下，可以通过设计来创造理想的条件，开发一种能够完全支持轴承载荷的会聚楔形润滑剂，同时完全分离配合表面。另一方面，当载荷在很小的接触面积上承载时，产生弹水动力（EHL）区，导致表面产生较大的弹性变形。虽然沿连接处的压力分布和膜厚可以准确地预测，但预测牵引力是有问题的，因为膜的流变特性很难预测，记住压力可能会引起粘度的大变化。润滑脂起到密封胶的作用，防止泄漏，阻碍腐蚀性污染物的进入，是一种良好的阻尼和降噪介质；因此，它是一种非常常见的润滑剂。尽管润滑脂被用于润滑安装在大量机械系统上的至少200亿个轴承中的80%以上，但对其行为的有限了解（以前被认为与油相似）正在导致与尖端技术相关的应用过早失效的问题。使用润滑脂的润滑被认为会产生严重的混合ehl，这意味着膜更薄，因此至少会发生一些凸起之间的接触。因此，由于需要将不连续膜中的牵引力与由于载荷、压力和磨损而变形的凸起相互作用产生的成分结合起来，这些系统中的摩擦预测变得更加具有挑战性。本研究的目的是建立并实验验证适用于油脂润滑饥渴滑动接触的摩擦和润滑失效预测的数学模型。一个成功的结果肯定会构成对尖端技术的发展和生产更高性能的轴承机构的巨大成就，这将产生大量的节能和环境效益。