Analysis of a crown-compensated impulse drying press roll : the lubrication problem

We consider the lubrication problem occuring in the channel formed by the inside surface of a rotating crown-compensated impulse drying press roll and the bottom surface of an internal hydrostatic shoe. By matching the mass flow of the lubricant through the capillaries in the shoe, which feed the channel, to the mass flow in the channel itself, and using a wedge approximation to the curvilinear channel, we are able to analytically compte expressions for the velocity fields in each distinct subregion of the channel, and the tangential and normal forces acting on the bottom of the shoe and the inside surface of the roll; these forces are then used to set up a system of equilibrium equations that are solved numerically for given applied loads and roll speeds. A complete discussion of results for two different shoe/roll configurations is presented along with some comparisons with experimental data.