Aligned and misaligned contacts of rollers to races in elastohydrodynamic finite line conjunctions

Abstract

The paper provides a solution for finite line concentrated contact of a roller-to-race under aligned and misaligned conditions. The lubricated contact conjunction is subject to an elastohydrodynamic regime of lubrication under isothermal conditions. Of particular interest are the edge stress discontinuities, represented by large secondary pressure spikes at the side constriction and to the rear exit in the contact domain. These pressure ‘pips’ are considerably larger in magnitude than those occurring in the central exit of the contact. The presence of pressure peaks inhibits the flow of lubricant in their vicinity, causing islands of minimum lubricant film thickness at the sides of the contact, referred to as the end closure films. The paper shows that the film shape and pressure distribution at the extremities of a finite line contact are not revealed by the traditional line contact solutions usually undertaken. The flow pattern becomes more complex with roller misalignment and the edge effects described are exacerbated. The paper provides the first ever solution of misaligned roller-to-race contact for moderate to high loaded elastohydrodynamic conjunctions. The numerical predictions conform well with both experimental and numerical findings of others for the cases where similar work has been reported.