Bearing seal do you know how many? How to choose seal used in different occasions? - bearing knowledge

In the rolling bearing two end face, will be equipped with corresponding sealing device. With dust cover with sealing ring, two performance is different, one is dustproof, one is the seal. Sealing is to keep the grease inside the bearing ( Oil) In use does not leak, the outside is not clean grease is also not easy to flow into, to ensure bearing in the lubrication state; Dust is to protect the dust or harmful gas bearing outside will not enter the bearing inner chamber, in case of bearing damage. Open, plastic cover seal, no seal, iron cover sealed bearings bearing installation sealing device is in recent years, in the past of the bearing are open, in order to ensure the bearing lubrication and dustproof, sealing device is located in the bearings on both ends of the shaft. Along with the development of the industry, food industry, in particular, the popularity of the modern office machinery and electrical appliances, equipment design is compact, the weight and four rolling bearing non-contact seal to prevent leakage, leakage, it appears the bearing itself bearing with seal. Common seal with a rubber or engineering plastic, also have a steel plate punch the sealing ring ( Or dust cover) 。 The sealing ring seal structure is varied, the sealing effect is different also. There is gap between seal ring and the rotation, said non-contact seal, the smaller the gap, the better sealing effect, but allow the speed of the shaft is smaller; Instead. Sealing ring with no clearance between shaft, said contact seal, seal lip contact contact area is larger, the better sealing effect, but interface xu shaft speed is smaller, on the contrary. Rubber seal bearing dustproof and sealing how said: dustproof expressed in Z, sealing with S ( Felt ring seal with FS said; LS in rubber seal) 。 Dust cover ZZ: retaining ring type dust cover plate bearing, miniature bearing, stamping processing of metal plate with a spring ring is fixed on the outer ring structure. 2 z: stamping steel plate bearing dust cover, reduce grease exudation, the metal steel plate by stamping processing reinforcement on the outer ring structure. Sealing ring TT: retaining ring type teflon bearing seals, mainly for the miniature bearing, the join of glass fiber teflon sealing ring with a spring ring is fixed on the outer ring structure. 2 rs: touch rubber bearing sealing ring, effectively prevent the invasion of the external foreign body, the rubber sealing ring embedded bearing outer ring, sealing ring in contact with the inner ring slightly. In according to the specific environment is different, the use of bearing dust cover and seal material used is not the same. The following simple introduce several kinds of materials used in the dust cover and seal. 1, bearing dust cover material bearing standard of dust cover material is cold rolled galvanized tin plate, also can use the ASI - sometimes 300 specifications of the stainless steel. 2, bearing seal ring material bearing ring with nitrile rubber as main material, in view of the high temperature environment, fluorine rubber and silicone rubber has been widely used. (1) silicone rubber: MQ/PMQ/VMQ/PVMP, temperature range: - 70 ~ 200 degrees Celsius; Hardness: 25 ~ 80; Features: high temperature and dry resistance, high wear resistance, the sunshine and ozone aging resistance; Limitations: the surface wear and poor crack resistance. (2) the hydrogenated ( Nitrile rubber) : HNBR/NEM, temperature range: - 35 to 165 degrees Celsius; Hardness: 50 ~ 90; Characteristics: resist heat, high ductility, corrosion resistance; Limitations: not suitable for ultra-low temperature conditions, avoid direct sunlight and chemical erosion. (3) : fluorine rubber FKM/FPM, temperature range: - 28 ~ 200 degrees Celsius; Hardness: 50 ~ 95; Features: high temperature resistant, significant resistance to corrosive, for oil products have corrosion resistance; Limitations: not suitable for low temperature working condition. (4) pp Rubber: ACM Rubber, temperature range: - 18 to 175 degrees Celsius; Hardness: 40 ~ 90; Characteristics: hot oil, sunshine and ozone erosion have a stronger ability to resist strong crack resistance at the same time; Limitations: the waterproof performance is poor, not suitable for ultra-low temperature working condition. Bearing with dust cover or seal related to the use requirements of the bearing. Dust cover is not in contact with the bearing inner ring, is contact installation. Sealing ring in contact with the bearing inner ring, is contact the installation. Therefore, dust cover bearing limit rotational speed is higher than the sealing ring of bearing, and seal bearing protection grade is higher than the dust cover, seal bearing the waterproof performance is good, seal bearing can better prevent oil outflow. Bearing seal is first and foremost in deep groove bearing enormous quantity wide application is more, in recent years, all kinds of rolling bearing with different bearing seal ring. So sealed bearing technology is one of the important direction of development, different structure bearing and use of different operating mode, require sealing ring structure and different materials.