Local Calculation of Load-Dependent Gear Power Losses of Cylindrical Gears

Abstract

The primary design criteria for gearboxes are (i) power density and load capacity; (ii) noise, vibration, and harshness; and (iii) efficiency and heat balance. To meet these design criteria, it is essential to use accurate calculation models throughout the design process. The total power loss can be divided into portions of gears, bearings, seals, and other machine elements, of which the load-dependent gear power loss often makes up the most significant portion. The existing literature provides a number of calculation methods with varying levels of detail for mesh-local models that promise high accuracy; however, these are rarely used, partly due to a lack of validation. This study systematically compares mesh-averaged and mesh-local calculation models using experimental results from a twin-disk tribometer and various cylindrical gears. The study includes a wide range of operating conditions and different gear oils. Three calculation levels I, II, and III are defined. The results show good agreement between the calculated and measured load-dependent gear power losses, with the mesh-local models showing high accuracy. When comparing results for an internal gear, the mesh-local calculation model calculates 30% lower load-dependent gear power losses than the mesh-averaged calculation model, which aligns with initial experimental results. The findings of this study suggest that mesh-local models are viable for wider application.