Nonlinear dynamic behaviour and severity of lightly loaded gear rattle under different vibro-impact models and internal excitations

Abstract This investigation comprehensively compared the elastic contact and the modified stiff impact models, aiming for the lightly loaded backlash-induced gear rattle. Three meshing force models in backlash are incorporated into the elastic model independently. Unlike the previous uncoupled stiff impact model, the modified impact model considers the coupling between the pinion and gearwheel. Three scenarios were investigated with different components of two internal excitations, static transmission error (STE) induced periodical backlash and the time-varying meshing stiffness (TVMS). The analytical results show that the free and forced gear motion, nonlinear characteristics and rattle severity are strongly affected by STE rather than TVMS. Two studied hydrodynamic lubricant (HDL) models show different damping effects. The forced gear motion state and rattle sensitivities show a noticeable difference below 40rad/s2 and turn to a slight variation above 60rad/s2. Finally, the HDL model containing only the oil squeeze effect will likely match the experimental results. The experimentally detected STE component of the gearwheel suggests that an acceptable model should be considered in the gear rattle model.