FAG's imported bearing seat seal improvement plan "multi-stage pressure relief seal technology" experimental bearing seat seal ring can reduce lubricating oil leakage by reducing the pressure difference between the two ends of the seal without the need for extensive disassembly of the shaft. , and at the same time, the residual leaked lubricating oil flows back to the oil tank to achieve the purpose of shaft seal leakage prevention. Specific main technical indicators: "Multi-stage pressure relief seal technology" experimental bearing seat seal ring can be replaced without disassembly of the spindle in situ, and there will be no abnormal leakage of lubricating oil during the two-year normal operation cycle. The specific research content is as follows.
Research on sealing material selection and sealing ring performance optimization
In view of the working conditions and external environment of the ship and the existing shortcomings of the zero-diameter sealing ring, a new sealing ring that is more suitable for the intermediate bearing seat of the ship's stern shaft is selected or developed. The research on sealing material selection mainly adopts experimental research methods. Select several groups of materials with good elasticity, aging resistance and wear resistance to make sealing rubber rings with wear self-compensation function and reasonable contact surface. Conduct targeted wear resistance and sealing performance tests, preferably suitable for the middle of the ship's stern shaft. FAG imported bearing seat sealing rings and sealing material technology mainly use the existing domestic mature technology, and improve on this basis as needed to meet the requirements. This is mainly due to the fact that this technology is a specialized technology and requires a long period of specialized research. The structure and stress deformation research of seals mainly uses finite element analysis method to provide basis for structural design. Use design analysis and experimental methods to reduce the pressure on the friction surface and reduce friction and wear. Research on the anti-wear performance and life of seals mainly uses experimental research methods. Through experimental comparison of various sealing materials, a suitable bearing seat sealing ring is selected using a step-by-step optimization method. The selection of sealing sequence, materials 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 the installation environment, product characteristics such as chemical attack, tendency to agglomerate, and solid components. This plays a fundamental role in seal design for products or slurries with high solid content.
Development of sealing structure of FAG imported bearing seat
The sealing effect of the single-stage seal is not ideal, and the lubricating oil leakage of the bearing seat is serious. On the premise of meeting the structural dimensions of the shaft system, it is planned to develop a new sealing system concept for the stern shaft intermediate bearing seat. The new system adopts a secondary seal plus oil retaining ring structure. The new oil retaining ring can partially prevent the lubricating oil in the oil tank from seeping along the shaft surface. A leak occurs from the seal. If the first-level 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-level 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 extends the service life. The seal uses 1 positive pressure rubber ring and 1 negative pressure rubber ring. When the medium passes through the seal, the first-stage rubber seal seals the medium. Even if a small amount of medium passes through the first-stage rubber ring, the second-stage rubber ring comes into play. The external pressure is greater than the pressure inside the shaft seal, and the pressure difference between the inside and outside is Under the action of the FAG imported bearing, the two-stage sealing ring works at the same time to press the rubber ring firmly on the main shaft, which has a sealing effect; when the FAG imported bearing is running, the pressure inside the shaft seal is greater than the atmospheric pressure, and the first-stage sealing ring works, entering 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 against the main shaft, thereby achieving a sealing effect. Therefore, multi-stage sealing is achieved by utilizing the effect of liquid pressure difference and through secondary sealing elements, rather than relying on packing extrusion or spring action to achieve sealing requirements. According to pressure and structural requirements, rubber rings can also be added to achieve multiple levels of sealing. Level sealing cooperation greatly extends the service life of the seal, avoids frequent replacement of seals, and achieves better sealing effect.
