An oil seal is a sealing component used to prevent the leakage of lubricating oil and the intrusion of external impurities. It is widely employed in various mechanical devices. Its primary function is to isolate the lubricated components within the transmission mechanism from the output components, thereby preventing the leakage of lubricating oil. The structure of an oil seal typically consists of a metal frame, a tightening spring, and a sealing rubber. Common materials include nitrile rubber, fluororubber, and polyurethane, etc. The types of oil seals include single-lip oil seals, double-lip oil seals, and liquid-sealing oil seals, which are suitable for different working conditions and requirements.