The development history of bearing sealing technology1

The development history of bearing sealing technology

Corresponding sealing devices are installed on both ends of the newly developed rolling bearing. Its function, on the one hand, is to keep the grease (oil) inside the bearing from being lost during use, to ensure that the bearing is in a lubricated state, and on the other hand to protect the dust outside the bearing or the harmful gas from the seal factory from entering the bearing cavity, To prevent damage to the bearing. Commonly there are rubber or engineering plastic sealing rings, and there are also sealing rings (or dust caps) punched from steel plates. The sealing structure of its sealing ring is various, and its sealing effect is also different. If there is a gap between the seal ring and the shaft, it is called a non-contact seal. The smaller the gap, the better the sealing effect, but the smaller the allowable shaft speed; on the contrary, the opposite is true. If there is no gap between the seal ring and the rotating shaft, it is called a contact seal. The larger the contact area of ​​the seal ring's contact lip, the better the sealing effect, but the smaller the allowable shaft speed, and vice versa. The main research content of sealing technology is to research and develop corresponding sealing devices applied in different working conditions, as well as the compatibility of the sealing ring material and the corresponding grease. The selection of the bearing installation sealing device is a matter of more than 4 years in the mechanical seal factory. In the past, the bearings were all open. In order to ensure the lubrication and dustproof of the bearing, the sealing device was installed on the shaft at both ends of the bearing. With the development of the industry, especially the popularization of the food industry, modern office machinery and home appliances, the equipment is required to be compact in design, and the mechanical seal of the weight pump should be reduced to prevent water leakage and air leakage. First of all, it is widely used in deep groove bearings with a large quantity and a wide range. In recent years, various types of rolling bearings have appeared with different sealing rings. Bearing sealing is one of the important directions for the development of bearing technology. A quarter has been installed with sealing rings. In the next ten years, there will be 2-3 kinds of bearing structures every year, and 20-30 million sets of bearings will be developed into sealed structure bearings. Different structural bearings and different working conditions require different structures and materials of the sealing ring, so the research and development workload is very large. Development trends at home and abroad Several major bearing companies in Japan (Seiko, Toyo, Fujiyoshi, etc.) represent the development direction of bearing sealing technology. They have an early history in the development of sealed bearing device technology, and the research depth is large, and the current sealing technology is relatively mature. It has developed from a single sealing lip to multiple sealing lips, and developed a non-contact seal from a contact seal; from the perspective of product types, both ball bearings and roller bearings are available. Following the international development trend, my country has also developed several types of bearings with sealing rings, deep groove ball bearings, water pump bearings, railway (tapered roller) bearings, needle roller bearings and short-element cylindrical roller bearings, among which deep groove ball bearings The output is the largest and the application is the most extensive. According to the recent quality inspection results of my country's sealed bearings by the State Technology Bureau, my country's sealed bearings have serious structural design problems, poor sealing effect, serious grease leakage, and strong user feedback. After analysis, the main reason is that the design structure of the current sealing ring in my country is unreasonable, the inner ring does not have a sealing groove, and the manufacturing accuracy is not high. Therefore, the future development trend of bearing sealing technology in my country is: to carry out sealing technology experiments represented by deep groove ball bearings, to find the best sealing ring structure and best sealing life, to carry out research on sealing materials, to find wear resistance, aging resistance, resistance to wear and tear. High temperature and anti-corrosion materials lay a technical foundation for improving the life of contact seals and developing seals that work under high temperature conditions or under harmful atmosphere conditions. Main research content and goals According to the current situation of poor quality of sealed bearings in my country, the main research content in the future is: firstly, research and test, and screen out the sealing ring structure of deep groove ball bearings and develop the corresponding bearing inner ring sealing groove structure, and carry out the current deep groove ball bearing. The replacement of the sealing structure of the groove ball bearing. Strive to make the sealing performance of this type of bearing catch up with the advanced level of similar products in the late 1990s in 2005; secondly, combined with the development of my country's car industry, develop high-temperature sealed bearings suitable for long-term work at high temperatures of 120-180 °C; The third is a new sealing structure for the series of tapered cylindrical roller bearings represented by railway vehicle bearings.