Simulation-based optimization of gearing efficiency using thin coatings

In order to increase the energy efficiency of gearboxes, the further viscosity reduction of gear oils to reduce splash and pumping losses is a suitable measure. However, the use of lowviscosity lubricants and the increase in the power density of gear units lead to increased operation of the gear teeth in the mixed friction regime. To counteract increasing wear, the use of friction- and wear-reducing thin coatings (DLC coatings) can be a possible solution. A good match between lubricant and coating is important here. Tests or thermo-elastohydrodynamic (TEHD) simulations can be used to evaluate the potential of coated tooth flanks. Simulations provide the opportunity to perform a potential evaluation at an early stage of development without generating high costs for prototype production. Selected TEHD simulations with different DLC coatings are used to show the influence of a coating on pinion and/or wheel on temperature development, frictional losses and efficiency, and which thermo-physical properties of the coatings are advantageous. © 2023 The Authors.