Rough tooth flank thermal elastohydrodynamic lubrication analysis model of spiral bevel gears

For time-varying meshing interface geometric and physical state evolution, an innovative rough tooth flank thermal elastohydrodynamic lubrication (TEHL) model is proposed for spiral bevel gears having complex meshing interface behaviors. Firstly, numerical simulation to the actual tooth flank generation is used for macro tooth flank geometry modeling. Then, numerical loaded contact analysis (NLTCA) solution showing a high computational efficiency is applied to output time-varying contact parameters including geometric curvature, entrainment and sliding velocity, load and pressure distribution are determined as the important input to TEHL computation. Moreover, a TEHL analysis model is established by considering non-Newton fluid and entrainment effect. In particular, the measured tooth flank roughness is added into the macro flank to get a new rough tooth flank TEHL analysis model. Some equation simplification and flow coefficient computational strategies are employed to get accurate oil film performance assessment. Finally, a spiral bevel gear set from aerospace engine central transmission system is exercised to show the effect of analysis model on micro flank TEHL performances for spiral bevel gears.