Effect of micro and macro pits of journal surface on radial pressure distribution of journal bearing

Abstract

The aim of this study is to find the optimum journal surface micro and macro pits (pores) to improve the load carrying capacity of journal bearing. The effects of various surface porosities on pressure distribution in radial bearings have been investigated. The journals used for experiment in this paper are separated in two groups. Various surface porosities have been achieved by subjecting the surfaces of the two aluminium journals (Al-6063) in the first group (CHE-I, CHE-II) to chemical reaction (etching process). The journals in the second group (COM-I, COM-II, COM-III) have been made of metal matrix composite (MMC) with aluminium based reinforced with SiC ceramic particles, using stir casting technique. For comparison of pressure distribution with that of non-porous journal, a smooth-surfaced journal (NPJ) is used. It has been found that an optimum size and distributive range of micro and macro-pits exists, where the load carrying capacity can be increased at approximately twice over that of an un-textured surface.