Experimental comparison between partially crowned and logarithmic roller profiles in cylindrical roller bearings

Abstract

A logarithmic profile is an essentially optimal geometry for rolling machine elements such as bearing rollers and raceways. Under most conditions of loading, it yields less stresses to give longer endurance. Lundberg first suggested the basic profile, and some researchers followed him by modifying it to suit engineering requirements. The authors also proposed a mathematical optimization method for various profiles including a logarithmic one in roller bearing applications. In this paper, rolling contact fatigue life tests are carried out to make a comparison of logarithmic, standard partially crowned and modified partially crowned rollers when they are applied to cylindrical roller bearings. Results show that the logarithmic and modified partially crowned rollers are comparable in fatigue life, and outlast the standard partially crowed rollers if they are fully lubricated. On the other hand, under poor lubrication, the logarithmic rollers are found to yield outstanding fatigue life over the modified partially crowned ones.