The Tribological Performance of Frictional Pair of Gas–Liquid Miscible Backflow Pumping Seal in Oil–Air Environment

The gas–liquid miscible backflow pumping seal (G-LMBPHS) is a non-contact mechanical that suitable for high-speed bearing chambers. However, the tribological properties and wear mechanisms of frictional pair G-LMBPHS in an oil–air environment have not yet been comprehensively studied. In this study, six pairs, consisting three hard materials (18Cr2Ni4WA, Al2O3 coating, Cr2O3 coating) two soft (metal-impregnated graphite [Metal-IG] resin-impregnated [Resin-IG]), were analyzed using disc-on-disc tribometer. An was created minimal quantity lubrication (MQL) system closed chamber. results show COF four pairs coatings graphites decreases gradually with increasing rotational speed, composed coating Resin-IG lowest between 0.022 0.03. Therefore, are mixed condition. lubricant adsorbed stored pits on surface coatings, enhancing hydrodynamic effect spiral grooves reducing by up to 45%. Metal-IG has better resistance than Resin-IG, lightest wear. This study provides important basis selection environments.