An Improved Friction Coefficient Calculation Model for Gear Pair with Spalling Fault

As one of the classical excitation types, gear friction status in meshing zone has a significant impact on vibration-noise levels of gear transmission systems (GTSs). Moreover, existing simulation models are difficult to effectively calculate the friction coefficient of gear pairs with spalling faults considering surface morphology, which is not conducive to fault diagnosis of GTSs. Motivated by this, this study presents a tooth surface modeling method to simulate the localized spalling defects using Gaussian filter, further an elastohydrodynamic lubrication (EHL) model is improved for calculation of friction coefficient. Subsequently, the changes in friction coefficient under different-size spalling defects are investigated. On the one hand, the proposed method has a higher accuracy in solving the friction coefficient of meshing area. On the other hand, the size of spalling defects is proven to be a key factor affecting the friction coefficient. These findings are of significance for gear fault diagnosis and maintenance.