Mixed and thermal elastohydrodynamic simulation of cylindrical gear designs

In light of the current efforts to protect the climate and reduce CO 2 emissions, the reduction of load-dependent gear power loss and extension of lifetime are key objectives in gearbox design. In order to achieve this, accurate and detailed prediction models are required. This study employs a mixed TEHL simulation model, which is integrated into an iterative scheme that includes the calculation of gear bulk temperature. The validity of the simulated load-dependent gear power losses was verified for a range of gear geometries and operating conditions. A comparison with mesh- and contact-averaged approaches demonstrates higher accuracy. An exemplarily analysis of the load-dependent gear power loss through local analysis and tooth flank geometry modification shows a potential to reduce the relative load-dependent gear power losses by over 50%. Simulated surface and depth volume material stresses indicate that a tooth flank geometry modification exerts a pronounced effect on the distribution of material stress in lubricated gear contacts. The mixed TEHL simulation approach allows for mesh- and contact-local gear design considering gear power loss and load capacity.