A thermal tribo-dynamic mechanical power loss model for spur gear Pairs

•Couple the gear dynamics and gear tribology disciplines.•Include thermal lubrication behavior.•Investigate mechanical power loss under thermal tribo-dynamic condition.

This study proposes a formulation for the description of the gear mesh mechanical power loss under the thermal tribo-dynamic condition. A six degree-of-freedom motion equation set and the thermal mixed elastohydrodynamic lubrication governing equations are coupled to model the mechanical power loss under the condition where the gear dynamics and tribology disciplines interact. The important role of the gear thermal tribo-dynamics in power loss is demonstrated by comparing the predictions of the proposed model to those under the thermal quasi-static condition, and those under the iso-thermal tribo-dynamic condition. Considering an example spur gear pair, the impacts of the lubricant inlet temperature, input torque, and surface roughness on gear mesh mechanical power loss under the thermal tribo-dynamic condition are also investigated.