FAG imported bearing seat sealing improvement plan "multi-stage pressure relief sealing technology" experimental bearing seat sealing ring, and reduces lubricating oil leakage by reducing the pressure difference at both ends of the sealing element in a working environment without the need for disassembly to a large extent. At the same time, residual leaked lubricating oil is returned to the oil tank to achieve the purpose of preventing shaft seal leakage. Specific main technical indicators: The experimental bearing seat sealing ring of the "multi-stage pressure relief sealing technology" can be replaced in the original position of the main shaft without disassembly, and there is no abnormal leakage of lubricating oil during the normal operation cycle of two years. The specific research content is as follows.

Research on Selection of Sealing Materials and Optimization of Sealing Ring Performance

In response to the working conditions and external environment of ships, as well as the existing shortcomings of zero diameter sealing rubber rings, a new type of sealing rubber ring more suitable for the middle bearing seat of the stern shaft of ships is selected or developed. The research on the selection of sealing materials mainly adopts experimental research methods. Select several groups of materials with good elasticity, aging resistance and wear resistance, make sealing rubber rings with wear self compensation function and reasonable contact surface, carry out targeted wear resistance and sealing performance tests, and select the sealing rubber rings suitable for the FAG imported bearing seat in the middle of the ship's stern shaft. The sealing material technology is mainly to use the existing mature technology in China, 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 that requires a longer period of specialized research. The research on the structure and stress deformation of seals mainly adopts finite element analysis methods to provide a basis for structural design. Using design analysis and experimental methods to reduce the pressure on the friction surface and reduce friction and wear. The research on the anti-wear performance and service life of seals mainly adopts experimental research methods. By comparing various sealing materials through experiments, a step-by-step optimization method is adopted to select the appropriate bearing seat sealing rubber ring. 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 rotation of the shaft to be sealed, are important parameters for considering functional safety in design. In order to conduct evaluations, 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 erosion, tendency to clump, and solid components. This plays a fundamental role in sealing design for products or slurries with high solid content.

Development of Sealing Structure for FAG Imported Bearing Seat

The single stage sealing effect is not ideal, and the lubricating oil leakage of the bearing seat is relatively serious. On the premise of meeting the structural dimensions of the shaft system, it is proposed to develop a new sealing system for the middle bearing seat of the stern shaft. The new system adopts a two-stage sealing and oil blocking ring structure, and the new oil blocking ring can partially prevent the lubricating oil in the oil tank from seeping out along the surface of the shaft and forming a seal for leakage. If there is a leakage in the first stage seal, lubricating oil will enter the cavity between the two seals. Due to the oil leakage circuit at the bottom of the cavity, the leaked lubricating oil will not form pressure in the cavity, and there will be basically no oil leakage in the second stage seal. It can be seen that the multi-stage pressure relief seal reduces the degree of damage to vulnerable parts and extends their service life. Its seal uses 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 small amount of medium passes through the first stage rubber ring, the second stage rubber ring acts. The external pressure is greater than the pressure inside the shaft seal. Under the pressure difference between the inner and outer boundaries, the two stage sealing rings simultaneously act to firmly press the rubber ring onto the main shaft, achieving a sealing effect; When the FAG imported bearing operates, the pressure inside the shaft seal is greater than atmospheric pressure, and the first stage sealing ring plays a role. The leakage pressure generated by the lubricating oil entering the sealing ring oil seal 1 is converted into kinetic energy to work on the rubber ring, firmly pressing the sealing ring oil seal 2 onto the main shaft, achieving the sealing effect. Therefore, multi-stage sealing is achieved through secondary sealing elements using the effect of liquid pressure difference, rather than relying on packing compression or spring action to achieve sealing requirements. According to pressure and structural requirements, rubber rings can also be added to achieve multi-stage sealing fit, greatly extending the service life of the seal, avoiding frequent replacement of the seal, and achieving good sealing effect.