Sealed ball bearing，On both ends of the ball bearing, corresponding seals are installed. With dust cover and with seal, two different performance, one is dustproof, one is sealed. The seal is to keep the grease (oil) inside the bearing not to be lost in use, and the unclean grease outside is not easy to flow in to ensure the bearing is in lubrication state; the dustproof is to protect the dust or harmful gas outside the bearing from entering the inner cavity of the bearing to prevent damage to the bearing.
sealed ball bearing，Bearing installation sealing device, in order to ensure the lubrication of the bearing and dustproof, sealing device is located on the shaft at both ends of the installed bearing. With the development of industry, especially the food industry, modern office machinery and the popularity of home appliances, requiring compact equipment design, weight reduction but also to prevent the four rolling bearing non-contact seal leakage, air leakage, which appears bearing itself with sealing device bearings.
Commonly there are rubber or engineering plastic seals, there are also steel plate punching seal (or dust cover). Its seal ring sealing structure is diverse, and its sealing effect is not the same. There is a gap between the seal ring and the shaft, called non-contact sealing, the smaller the gap, the better the sealing effect, but the smaller the allowed shaft speed; the opposite is the opposite. If there is no gap between the seal and the shaft, it is called contact seal. The larger the contact area of the seal contact lip, the better the sealing effect, but the smaller the speed of the shaft is allowed, and vice versa.
Bearing dustproof and sealing how to indicate: dustproof with Z, sealing with S (felt ring seal with FS; rubber seal with LS).
ZZ: retaining ring type steel plate bearing dust cover, miniature bearings with, stamping processing of metal steel plate with spring tight ring fixed on the outer ring structure.
2Z: stamping type steel plate bearing dust cover, reduce grease seepage, with stamping process to metal steel plate reinforced on the outer ring structure.
TT: Retaining ring type Teflon bearing seal, mainly used for miniature bearings, adding glass fiber Teflon seal with a spring tight ring fixed on the outer ring structure.
2RS: Contact rubber bearing seal, effectively prevent the intrusion of external foreign objects, rubber seal embedded in the outer ring of the bearing, seal and inner ring slight contact.
The standard material of dust cap for sealed ball bearing is cold rolled tin plated steel plate, sometimes ASI-300 specification stainless steel is also used.
①Silicone rubber: MQ/PMQ/VMQ/PVMP, temperature range: -70~200 degrees Celsius; hardness: 25~80; characteristics: resistance to high temperature and dryness, higher wear resistance, aging resistance to sunlight and ozone; limitations: poor surface wear and crack resistance.
②Hydrogenated (NBR): HNBR/NEM, temperature range: -35~165 degrees Celsius; hardness: 50~90; characteristics: heat resistance, high ductility, chemical corrosion resistance; limitations: not suitable for ultra-low temperature conditions, avoid direct sunlight and chemical erosion.
③Fluorine rubber: FKM/FPM, temperature range: -28~200 degrees Celsius; hardness: 50~95; characteristics: high temperature resistance, significant chemical corrosion resistance, corrosion resistance to petroleum products; restrictions: not suitable for low temperature working conditions.
④Polypropylene rubber: ACM Rubber, temperature range: -18~175 degrees Celsius; hardness: 40~90; characteristics: strong resistance to hot oil, sunlight and ozone erosion while having strong anti-cracking properties; limitations: poor waterproof performance, not suitable for ultra-low temperature working conditions.
