Abstract:Coatings are widely used in roller bearings to enhance interface performance and improve fatigue life.In order to study the effect of coatings material properties on the lubrication performance of the roller bearings,the finite length line contact elastohydrodynamic lubrication model incorporating with coating properties was established.The influence of the coating material properties and coating thickness on lubricant film pressure and film thickness were investigated.The results show that as the coating thickness increases,the minimum film thickness for the stiff coating initially increases then decreases,while the minimum film thickness for the soft coating initially decreases then increases at light loads,and always decreases at heavy load.As the velocity increases,the pressure spike at the exit region increases,especially for the stiff coating.And the film thickness also increases,the flat region of the film decreases,the local reduction of the film thickness at the exit region increases.In order to improve the lubrication performance,when using a thicker soft coating,the crown value of the roller should be increased.However,when using a thicker stiff coating,the crown value of the roller should be reduced.