Influence of the ultrafine oil additives on friction and vibration in journal bearings

In order to study the influence of ultrafine additives on hydrodynamic lubrication in journal bearings, this paper combines experimental and simulative approaches. The lubricants׳ samples were obtained by means of adding the fullerene black, fullerenes, molybdenum disulfide and fluoropolymer in quantity no higher than 0.05% of the mass in base low-viscosity mineral oil. The experiment was made during the run-down of the rotor, and we measured the friction coefficient in the journal bearing and the vibrations of its housing. The simulation model based on the developed methodology of setting and solving of the variational problem, allowed to explain and reproduce the results of the experiment. Ultrafine additives significantly decreased the load-carrying capacity and the friction coefficient in the journal bearing, as well as the vibration level in the bearing. The rate of lowering of friction and vibration directly depended on the level of pseudoplastic properties of the sample. The best results were shown by samples with fullerene black and fluoropolymer.