Modeling and Analysis of High-Load and High-Speed Involute Spur Gear Systems in Adverse Lubrication

This article presents a mathematical model for the meshing of involute spur gears in mixed lubrication. The model is formulated by integrating a gear meshing model with a thermal tribofilm mixed lubrication model. The resulting model can produce a number of important meshing variables from which the gear meshing performance and the tooth surface damage may be assessed. The model is used to analyze the performance of a high-load and high-speed gear system under various degrees of mixed lubrication. The results show a stronger desire to use low-module and high-pressure-angle gears than that suggested in earlier studies under good lubrication conditions. The results also show the high importance of enhanced heat transfer design of the system to prevent or reduce the possibility of the gear system migrating into temperature-induced unfavorable lubrication conditions. Although the model is developed for spur gears and results are obtained around a nominal system, the relations of the gear meshing tribology to the meshing loss and tooth surface damage behind these results should be fundamentally the same as those in other high-load and high-speed gear systems of different sizes and types. Therefore, the results and analysis may serve as qualitative guidance for the design considerations of high-performance gear systems in general.