Measurement of Lubrication Condition in Rolling Element Bearings

Rolling element bearing performance is strongly dependent upon the degree of separation of rolling elements and raceways by means of a lubricant film. In critical applications, it is important to know the degree of surface separation, but the operating conditions are often not known in sufficient detail to make accurate calculations and the effects of some conditions are not yet adequately understood. This paper describes a new instrument for directly measuring lubrication conditions in rolling element bearings in their application and in the laboratory. The capabilities of the instrument are demonstrated by comparison between calculated and measured degree of separation in a special test setup where details of the operating condition are known. The new instrument is a valuable tool for achieving optimum initial lubrication condition in a bearing application and in monitoring for lubrication failure.