Skeleton oil seal is relatively simple, generally composed of three parts: oil seal body, strengthen the skeleton and since the tight coil spring. FAG bearing seal body is divided into according to the different parts of the bottom of the waist edge and seal lip. Typically, the skeleton oil seal in the free state, the diameter is smaller than the shaft diameter, that is, a certain amount of interference. Therefore, when the oil seals after loading the oil seal seat and the shaft oil seal edge of the pressure and force of contraction of the coil spring from the tight on the shaft a certain radial tightening force, the pressure decreases rapidly after a period of time to run and even disappear, and thus, together with the spring can always compensate for oil seal from the tightening force.

Sealing principle: the SKF bearing oil seal edge to control the oil film between the oil seal and the shaft, this film has fluid lubrication characteristics. In the role of liquid surface tension, the stiffness of the film happens to make the film in contact with air-side to form a new moon surface, preventing the leakage of working medium, in order to achieve sealing of the axis of rotation. Oil seal sealing ability, depending on the thickness of the sealing surface of the film thickness is too large, the oil seal leak; the thickness is too small, dry friction may occur, causing the oil seal and shaft wear; no oil film between the seal lip and the shaft, you could easily cause heat, wear and tear.

Therefore, during installation, you must put some oil in the ring, INA bearing skeleton oil seal and the vertical axis line, if vertical oil seal sealing lip will lubricating oil drained from the shaft, can lead to excessive wear of the sealing lip. In operation, the lubricant in the housing slightly oozing a little, in order to achieve the ideal state form a film at the sealing surface.