Under the action of the skeleton oil seal, the rigidity of the oil film just makes the oil film and the air contact end form a crescent surface, which prevents the leakage of the working medium and realizes the sealing of the rotating shaft. The sealing ability of the oil seal depends on the thickness of the oil film on the sealing surface. If the thickness is too large, the oil seal will leak; if the thickness is too small, dry friction may occur, causing the oil seal and shaft to wear; if there is no oil film between the sealing lip and the shaft, it is easy to cause heat and wear. . Therefore, when installing, it is necessary to apply some oil on the sealing ring, and at the same time ensure that the skeleton oil seal is perpendicular to the axis line. If it is not perpendicular, the sealing lip of the oil seal will drain the lubricating oil from the shaft, which will also lead to excessive sealing of the lip. wear. During operation, the lubricant in the casing seeps out a little, so that it is ideal to form an oil film on the sealing surface.