Friction and flash temperature prediction of mixed lubrication in elliptical contacts with arbitrary velocity vector

The effects of friction and flash temperature are of significant importance on energy consumption and surface failures of mechanical components. However, available friction and flash temperature prediction method may not be appropriate for the condition occurring in real contact, such as spiral bevel and hypoid gears that entraining and sliding velocity directions do not coincide with the principal axis of ellipse, and most of them operate in the mixed lubrication regime due to large sliding speed and serious surface roughness. In the present study, a friction and flash temperature prediction approach for this problem is proposed based on a mixed EHL model most recently developed by Pu and Zhu et al. (2014) [20]. Besides, the prediction method is validated by comparing its results with experimental measurements by means of a roughness ellipsoid-on-disc contacts considering the surface velocity directions under severe operating conditions. In addition, numerical simulations are conducted to systematically study the influence of surface velocity directions corresponding to different sliding velocity on friction coefficient and flash temperature distribution in wide ranges of speed and load. As a result, the proposed friction and flash temperature prediction approach can be employed as an engineering tool for performance improvement of spiral bevel and hypoid gears and the other transmission components with the same characteristics. (C) 2016 Elsevier Ltd. All rights reserved.