Analysis On The Influences Of Surface Wear On The Ehl Of Involute Spur Grar

A transient thermal elastohydrodynamic lubrication (thermal EHL or TEHL) model of wearing surfaces in line contacts using the Ree-Eyring fluid of an involute spur gear has been developed. Based on the multi-grid (MG) method for solving the pressures, the multi-level multi-integration (MLMI) approach for obtaining the elastic deformation, a sequential column sweeping scheme for solving the energy equations and the numerical technique through shear stress analysis to get equivalent viscosity of non-Newtonian fluid, a series of complete numerical solutions have been obtained. Many influence factors such as thermal effects, surface wear, dynamic load, transient effects and the rheology characteristics of fluid are considered in this model. Mainly includes three parts: the transient isothermal EHL of surface wear of spur gear, the transient thermal EHL of surface wear of spur gear and the effect of dynamic load on the transient thermal EHL of surface wear of spur gear.Firstly, a transient isothermal EHL model of an involute spur gear has been developed on the base of geometric and transmission relations. Using multi-grid technique and considering the variation of entrainment velocity, equivalent curvature and dynamic load and surface wear induced by the effect of one or two pairs of teeth contact. , a comparative analysis solution has been obtained respectively with surface wear before and after about a bump and continuous wave roughness. The results show that the film pressure and the friction factor decrease and film thickness largen comparison with non wearing surface.Secondly, considering the effect of pressure and density and viscosity caused by temperature, a complete solution of thermal EHL of wearing surfaces has been obtained by calculating energy equation and basic equations.Thirdly, considering the effect of dynamic load on the engagement process of one pair of teeth on elastohydrodynamic lubrication of gear, the central film pressure, the central film thickness, the minimum thickness, the friction factor and the peak temperature rise along the contact line appear unstable fluctuations.