Surface layer analysis of helical grooved journal bearings after abrasive tests

Abstract

Hydrodynamic bearings can suffer from serious damage when operating in contaminated environments or under starved lubrication conditions. In such situations, hydrodynamic journal bearings with helical groove are less sensitive to damage compared with plain bearings. Contaminants are removed from contact zones by the helical groove on journal surface. The goal of this study is to clarify the wear mechanisms of journal bearings with helical groove on journal surface. Microscopic observations were made and residual stresses were measured to analyse the surface layer after abrasive wear tests. The surface of a smooth journal bearing deteriorated more extensively after the abrasive wear tests when compared with a grooved journal bearing. It was found that much more particles of Al2O3 were embedded in the soft material of the bearing that co-acted with smooth journal. The concentration of Al2O3 was reduced by groove on the journal surface, allowing contaminants to move out of the bearing clearance before they penetrate into material.