Influence of spin on film thickness in elastohydrodynamic starved point contacts. (April 2021)

• Record Type: Journal Article
• Authors: Porras-Vazquez, Alberto; Fillot, Nicolas; Vergne, Philippe; Philippon, David; Morales-Espejel, Guillermo E.
• Is Part Of: Tribology international. Volume 156(2021)
• Publication Date: 2021-04
• Subjects: Elastohydrodynamic lubrication -- Spin -- Starvation -- Flange roller-end contact; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2020.106825
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: The roller-end/flange contact in rolling-element bearings represents a crucial design point. Some of the main aspects defining the contact are its particular kinematics, integrating spinning and the occurrence of starved conditions, due to high curvature radii of the region. In the present study, we present the equations characterizing both spinning and starvation in isothermal EHD contacts lubricated by a Newtonian fluid. After the validation of the model for the case without spin, the analysis focuses, firstly, on characterizing the influence of spinning on the film thickness profile, particularly its global minimum film thickness. Secondly, it aims to evaluate how spinning interacts with starvation in circular contacts, quantifying its effects on the film thickness. Finally, this work provides analytical expressions to predict film thickness in such specific operating conditions. Graphical abstract: Numerical interferograms of 4 cases combining spin and no spin, as well as fully-flooded and starved conditions. Image 1 Highlights: A new model, integrating spinning and diphasic flow, evaluates the influence of starvation in large-size spinning contacts. From various spin and lubricant supply cases, it is shown that spin has little to no effect on the maximum film thickness. Film thickness reduction with spin differs from classical starvation and becomes irregular along the transverse direction. While spinning generates local maxima and minima in the contact area, starvation further reduces the overall film thickness. If exposed to both phenomena, film thickness reduction is more important in the local maxima area, where the speed is faster. The effect of both spin and starvation on critical film thickness changes can be quantified by analytical expressions.