Measurement of lubrication conditions in a rolling element bearing in a refrigerant environment

Abstract

PurposeThe ability to build up a film thickness separating the contacts in the bearing is essential to assure long service life of rolling element bearings. Rolling element bearings used in refrigeration suffer from poor film thickness due to decreased viscosity of the lubricant by the dilution of refrigerant in the oil. The purpose of this paper is to redesign a bearing test apparatus equipped with a capacitance measuring device able to monitor the lubrication status in the bearing online and include experiments to verify the capacitance measuring technique.Design/methodology/approachThe objective is to design a complete system to study film build up in rolling element bearings in a refrigerant environment and to use and evaluate the capacitance/resistance measuring technique.FindingsThe investigation shows good correlation between denting on tested bearings and the identified contacts by the capacitance measuring apparatus. The method is also useful when studying lift‐off or run‐in of a bearing.Originality/valueIn this paper, a bearing test apparatus is redesigned and equipped with a capacitance measuring device able to monitor the lubrication status in the bearing on‐line. The paper includes experiments to verify the capacitance measuring technique.