FAG Imported Bearing Seat Seal Failure Reasons and Improvement Schemes

FAG's imported bearing seat seal improvement scheme "multi-stage pressure relief seal technology" experimental bearing seat seal ring, and reduces the oil leakage effect by reducing the pressure difference between the two ends of the seal without the need for a large degree of disassembly such as shaft extraction. , At the same time, the residual leaked lubricating oil will flow back to the oil tank to achieve the purpose of preventing leakage of the shaft seal. Specific main technical indicators: "multi-stage pressure relief type sealing technology" experimental bearing seat sealing ring can be replaced without dismantling the main shaft in situ, and there is no abnormal leakage of lubricating oil during the two-year period of normal operation. The specific research contents are as follows.

Research on sealing material selection and performance optimization of sealing ring

In view of the working conditions and external environment of ships and the existing shortage of zero-diameter sealing rubber rings, a new sealing rubber ring that is more suitable for the intermediate bearing seat of the stern shaft of ships is selected or developed. The research of sealing material selection mainly adopts the method of experimental research. Select several groups of materials with good elasticity, anti-aging and wear resistance, make a sealing rubber ring with wear self-compensation function and reasonable contact surface, and carry out targeted wear resistance and sealing performance tests, preferably suitable for the middle of the stern shaft of the ship FAG imported bearing seat sealing rubber ring, the sealing material technology mainly uses the existing domestic mature technology, and improves it on this basis as needed to meet the requirements. This is mainly due to the fact that this technology is a special technology and requires a long time of specialized research. The finite element analysis method is mainly used to study the structure and stress deformation of the seal, which provides the basis for the structural design. Design analysis and experimental methods are used to reduce the pressure on the friction surface and reduce friction and wear. The research on the anti-wear performance and life of seals is also mainly based on experimental research methods. Through the experimental comparison of a variety of sealing materials, a step-by-step optimization method is used to select the appropriate sealing rubber ring for the bearing seat. The selection of sealing sequence, material and additional equipment depends on different parameters. The pressure and temperature of the medium to be sealed as well as the diameter and number of revolutions of the shaft to be sealed are important parameters for functional safety in the design. For evaluation, the pressure of the product and the roughness of the sealing surface are often used as evaluation values. Other edge conditions include installation environment, product characteristics such as chemical attack, tendency to cake and solid parts. This plays a fundamental role in seal design for products or slurries with high solids content.

Development of Sealing Structure of FAG Imported Bearing Seat

The sealing effect of single-stage seal is not ideal, and the leakage of lubricating oil in the bearing seat is relatively serious. On the premise of satisfying the shaft structure size, it is proposed to develop a new concept of the sealing system of the stern shaft intermediate bearing seat. The new system adopts the structure of secondary seal and oil deflector. The new oil deflector can partially prevent the lubricating oil in the oil tank from seeping along the surface of the shaft. leak out of the seal. If the first-stage seal leaks, the lubricating oil will enter the cavity between the two seals. Since there is an oil drain circuit at the bottom of the cavity, the leaked lubricating oil will not form pressure in the cavity, and the second-stage seal will basically not leak. oil phenomenon. It can be seen that the multi-stage pressure relief seal reduces the damage of wearing parts and prolongs the service life. The seal adopts one positive pressure rubber ring and one negative pressure rubber ring. When the medium passes through the seal, the first-stage rubber seal seals the medium. Even if a little medium passes through the first-stage rubber ring, the second-stage rubber ring plays a role, and the external pressure is greater than the pressure inside the shaft seal, and the pressure difference between the inside and outside Under the action of the two-stage seal ring at the same time, the rubber ring is firmly pressed on the main shaft, which has a sealing effect; when the FAG imported bearing is running, the pressure in the shaft seal is greater than the atmospheric pressure, and the first-stage seal ring plays a role and enters The leakage pressure generated by the lubricating oil in the sealing ring oil seal 1 is converted into kinetic energy to do work on the rubber ring, and the sealing ring oil seal 2 is firmly pressed on the main shaft, which has a sealing effect. Therefore, the multi-stage seal is realized by the action of the liquid pressure difference and through the secondary sealing element, rather than by packing extrusion or spring action to achieve the sealing requirements, and according to the pressure and structural requirements, a rubber ring can also be added to achieve multi-stage sealing. It can greatly extend the service life of the seal, avoid frequent replacement of the seal, and achieve a better sealing effect.