A Frictional Efficiency Loss Model for Helical Gears Available to Purchase

In this study, a methodology for prediction of mechanical efficiency of helical gear pairs is proposed. It combines a gear load distribution model with a friction coefficient computation model. The load distribution model is used to provide contact pressures and other contact parameters to the friction coefficient model. Two different approaches are used for the computation of the friction coefficient. The first approach employs a number of published empirical friction coefficient formulae that were typically obtained through twin-disk tests. The second approach uses a rough-surface, thermal elastohydrodynamic lubrication (EHL) model. A simplified, smooth-surface version of the EHL-based model is also proposed. The friction coefficient distributions along the tooth contact surfaces are then used to calculate the friction forces that yield the instantaneous mechanical efficiency loss of the gear pair at a given mesh angle. The model is used to study the influence of a number of design, lubricant and surface related parameters as well as load and speed on the mechanical efficiency of helical gear pairs.