Internal Friction of Ball Bearings at Very Low Temperatures

Results of the study on the internal friction of steel ball bearings made of X65Cr14 alloy and ceramic bearings made of zirconium oxide operating at temperatures lowered by liquid nitrogen down to –195 °C are presented in this paper. Standard grease added by the manufacturer, while graphite and molybdenum disulphide powder were used for lubrication of the bearings during the measurements. Tests were also carried out to examine the performance of the bearings operating without lubrication. The power of bearing internal friction versus temperature was measured. The lowest bearing internal friction was observed for molybdenum disulphide, whose effective lubricating performance was verified for both types of ball bearings. Graphite powder was almost equally effective with the advantage of being suitable for use in machines that come into contact with food.