Interaction of gear tooth friction and misalignment effect on the vibro-acoustics of spiral bevel gears

This work investigates the combined effect of misalignment and elastohydrodynamic lubrication (EHL) of spiral bevel gears. The analysis employs a proposed EHL model on an asymmetric grid to calculate the pressure, the film thickness, and the friction force to determine their combined effect with misalignment on the dynamics of spiral bevel gears. First, the gear mesh parameters, such as rolling velocity and quasi-static mesh force, are calculated using a specialized tooth contact analysis program with and without misalignment. These results are then -applied to the proposed EHL model to calculate contact pressure and film thickness, from which the gear tooth friction force and the coefficient of friction are determined. Finally, a multi-body nonlinear dynamic model which considers the effect of lubrication and friction force is applied and the dynamic response of spiral bevel gear are compared to examine the combined effect of misalignment and friction. It should be noted that practical spiral bevel gears applications will have both misalignment and friction between the gear tooth surfaces. Thus, this study is of importance as it represents the actual scenario in which the spiral bevel gears are employed.