The Effect of Surface Roughness to Elastohydrodynamic Lubrication in Spur Gear with non-Newtonian Lubricant

Abstract

This paper presents the effect of surface roughness to performance characteristics of transientisothermal elastohydrodynamic lubrication in line contact of spur gear with non-Newtonian fluids. The timedependent Reynolds equation, elastic equation and viscosity equation were formulated for compressible fluid.Newton-Raphson method and multigrid method were implemented to obtain the film pressure profiles, filmthickness profiles and traction coefficient in the contact region at various loads and speeds. The simulationresults show that roughness amplitude has a significant effect on the film pressure in the contact region. Thefilm thickness decrease but traction coefficient increases when surface of gear teeth was rough surface. Thefilm thickness reaches its minimum at approach point when the line of action increase film thickness wasincrease. The minimum traction coefficient was occurrence at pitch point. The increasing loads, film pressureand traction coefficient increase but film thickness decrease. The film thickness and traction coefficientincrease when the speeds increase.