The effect of surface layer with bleeding properties in rolling/sliding contact

Rolling/sliding contact of two layered rotating cylinders is analyzed. The substrate of each cylinder is modeled as an elastic body. Under loading, th e surface layer is allowed to deform as an elastic or viscoelastic body and lubricant can release from this layer and enter the contact providing the lubrication with limited flow rate. The influence of the surface layer prop erties on contact pressure, film thickness and friction coefficient is anal yzed for various operating conditions. The results indicate that due to the bleeding properties of the surface layer the EHD regime of lubrication has some distinctive properties. The film thickness tends to a constant value and the coefficient of rolling friction decreases as the Sommerfeld number increases for both the elastic and viscoelastic models of the surface layer .