Effect of Roller Profile and Misalignment in EHL of Finite Line Contacts

All the rollers of cylindrical and tapered roller bearing are axially profiled to relieve high edge stress concentration caused by mainly their finite length and by misalignment. In this paper, a numerical solution of the EHL of finite line contacts is presented for axially profiled and misaligned (tilted) cylindrical roller. Applying a finite difference method with non-uniform grids and the Newton-Raphson method, the highly nonlinear problems are systematically solved. Physically consistent solutions are obtained for moderate load and material parameters, and very small misalignment. For two different dub-off radii and various misalignment angles, contours and sectional plots of pressure and film shape near edge regions are compared, and variations of the minimum film thicknesses are showed. The effect of misalignment on the EHL pressure distribution is much higher than the film shapes. The absolute minimum film thickness decreases highly with misalignment angle and profile radius while the central minimum film thickness at the footprint center is nearly constant.