Tribological and aerosol mechanics aspects of oil mist lubrication

Abstract

The tribological performance of the oil mist lubrication has been evaluated. A ten bearing censored group endurance was conducted to evaluated the influence of oil mist lubrication on the life of rolling element bearings as compared to conventional oil sump lubrication. It has been found that the oil mist lubrication provides better fatigue and wear protection to the bearings compared to the conventional sump lubrication, under identical operating conditions. The performance of the test bearings were also monitored for the oil mist and oil sump lubrication for prolonged periods of time operating under identical conditions. The test bearings with oil mist lubrication operated cooler (about 10° C) and with less friction (about 25%) compared to the conventional oil sump lubrication. It has also been found that oil mist (under the test conditions) formed and maintained a carbonaceous solid lubricating layer on the operating surfaces of bearings. The basic operating principles (aerosol aspects) of the oil mist lubrication system have been investigated for the first time. The study included the penetration of oil mist in the supply line, reclassification of oil mist and deposition of oil mist in bearings. The results indicate that there is room for improvements in the basic operation of the oil mist lubrication system. The results should form a basis for improving the system to provide the best possible protection to bearing surfaces with the least amount of oil and stray mist.