A novel FSI-thermal coupled TEHD model and experimental validation through indirect film thickness measurements for the lubricating interface in external gear machines

A novel fluid-structure interaction-thermal coupled model for the lateral lubricating gaps between gears and lateral bushes in external gear machines (EGM) is presented in this study. The model is the first of the lateral lubricating interface in EGMs capable of considering heat transfer, thermal effects in the fluid film and solid components as well as thermo-elastic deformation of the solids enabling prediction of the film thickness in EGM lateral gaps considering thermoelastohydrodynamic lubrication. Model validation is performed using lateral gap leakage measurement which is dependent on absolute film thickness. A novel relative lubricant film thickness measurement method in gear machines using capacitive sensors is also presented, and used to validate the spatial film thickness predictions from the model.