A Computer Program Package for the Prediction of EHL and Mixed Lubrication Characteristics, Friction, Subsurface Stresses and Flash Temperatures Based on Measured 3-D Surface Roughness

Friction at the Contact Between Bearing Balls and Cotton-Phenolic Cage Material

“…Above this speed, insufficient oil is present to be entrained into the contact, leading to thinner films than in a fully flooded contact at the same speed.' 9 The contacts in these experiments are probably starved, particularly at high speeds. The exact effect of starvation on the COF is complicated by the effects of asperity contacts, particularly with a surface as rough as that of cotton-phenolic.…”

“…Models of elastohydrodynamic contacts have begun to address these questions, but for contacts under very different operating conditions than those in these experiments. 9 A third possibility for lower COF at high speed than predicted by room-temperature, fully flooded conditions is slip between the lubricant and the surface. When solving the Reynold's equation, one component of the boundary conditions is usually the "no-slip" condition, in which the oil at the surface is assumed to travel at the speed of the surface, and all the sheer takes place within the oil and none between the surface and the oil.…”

Friction coefficient in mixed lubrication: A simplified analytical approach for highly loaded non-conformal contacts

“…In order to determine the fraction of load supported by the lubricant film, Zhu and Hu 11 propose the load share function (7) for point contact With regard to the friction coefficient, various results have been published for boundary lubrication. 4,29,30 In the case of steel-steel contacts, values have been determined around 0.07-0.15, which depend on the type and amplitude of the roughness, 11 with higher values corresponding to polished surfaces.…”

“…7 As this effect becomes increasingly pronounced, it tends towards a boundary lubrication regime, which is characterised by the roughness asperities withstanding the entire load. 3,6 As a result of an intensive research, numerous models [7][8][9][10][11] have been developed to predict friction (or traction) coefficient and other parameters of interest in non-conformal contacts under mixed lubrication, with increasing levels of precision and complexity, especially through the use of simulations based on numerical calculations.…”

Effects of Geometry Design Parameters on the Static Strength and Dynamics for Spiral Bevel Gear

“…Zhu and Hu [18] and Castro and Seabra [19] proposed the following definition of the load share function for point contacts given by …”