Review and Study of Effect of Water Contaminants in Lubrication in Ball Bearing through Vibration Analyses

Abstract

Rolling element bearings are common in rotating machinery, automobiles and aerospace etc. For friction less and continuous running, bearing is lubricated with grease. Greases are contaminated with solid particles and liquids. This is one of the main reason for bearing failure, here we analyze and study the effect of liquid contaminant in lubrication on vibration response. It is difficult, but not impossible, to study the ingress of liquid (water) into bearings. Water is contaminated/ entrapped in various forms like rain water, soapy water, salt water and municipal cor. water etc. These water is contaminated with greases due to rain, human error, experiment etc. The ability of a lubricating grease to withstand, reject or absorb water is different for different greases. Hence we investigate the effect of liquid contamination of lubricant on the behaviour of rolling bearings. Bearing with contaminants are subject to failure under continuous running, so there Liquid contaminate such as water with salt, soap solution at different concentration level and rain water is used to contaminate the lubricant. An experimental test is to be performed on the ball bearings and the trends in the amount of vibration affected by the contamination of the grease determined. Vibration signatures were analyzed with respect to root mean square (RMS) values of amplitude in terms of acceleration and also with respect to acceleration values at particular defect frequencies. In rolling bearings, a sudden increase in vibration can be indicative of failure occurrence.