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: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=547225
• 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表面之间引入一种物质（流体或固体），以减少摩擦和磨损，并散热。在流体动力学状态下，可以通过设计来创造理想的条件，以开发能够完全支撑轴承载荷同时完全分离配合表面的润滑剂的收敛楔。另一方面，当载荷由非常小的接触面积承载时，产生弹性流体动力学（EHL）区域，引起显著的表面弹性变形。虽然可以准确地预测沿着接合处的压力分布和膜厚度，但是预测牵引力是有问题的，因为膜的流变性质难以预测，记住压力可能引起粘度的大的变化。润滑脂作为密封剂，防止泄漏和阻止腐蚀性污染物的进入，它是一种良好的阻尼和噪音抑制介质;因此它是一种非常常见的润滑剂。尽管润滑脂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中过早失效的问题。使用润滑脂的润滑被认为会产生饥饿混合EHL，这意味着膜更薄，因此至少一些粗糙体之间发生接触。因此，在这些系统中的摩擦的预测成为一个更具挑战性的任务，由于需要联合收割机的牵引力在一个不连续的膜和组件所产生的相互作用的凹凸不平，这是由于负载和压力变形，以及受到磨损。本研究的目的是开发和实验验证数学模型的预测适用于脂润滑饥饿滑动接触的摩擦和润滑故障。一个成功的结果肯定会构成一个伟大的成就，对尖端技术的发展和生产更高性能的轴承机制，这将产生大量的能源节约和环境效益。