There are several materials used to manufacture oil seals. They are discussed below.
Seals are classified by O.D. wall material, lip type, and whether they have a spring or not.
Major oil seals are specified in ISO 6194-1 and JIS B 2402-1.
Table 2 shows the common types of oil seals, while Table 3 shows the features of each type of oil seal.
Table 4 lists the JTEKT oil seal type codes and corresponding ISO and JIS standards.
This is one of the frequent reasons for oil seal failure, and this is majorly because of the volatility of any of the elastomer’s constituents. These causative constituents may be part of the elastomer formulation, or gases that got entrapped in the elastomer during the molding process. The deceiving fact about this failure is that sometimes the oil seal won’t show any visual sign of out-gassing, however, sometimes when the out-gassing is extreme, they shrink.
Die-cut rubber gaskets offer several advantages over other sealing materials, such as flexibility, resilience, chemical resistance, and thermal stabilityFront pump input seal
For bisphenol-cured VDF/HFP/TFE polymers, calcium hydroxide level should be low and magnesium oxide level should be high to promote adhesion to metal inserts. Thermal black or mineral fillers generally give good adhesion.3 For most adhesive systems, it is necessary to limit postcure temperatures to about 200°C (392°F).3
However, proper installation and maintenance of TC oil seals are crucial for their effective functioningCommon materials used in oil seals include nitrile rubber, fluorine rubber, silicone rubber, acrylic rubber, polyurethane, polytetrafluoroethylene, etc. When selecting the material of the oil seal, the compatibility of the material with the working medium, the adaptability to the working temperature range and the ability of the lip to follow the rotating shaft at high speed must be considered. When the oil seal is working, the temperature of its lip is higher than the working medium temperature by 20~50°C. Attention should be paid when selecting the oil seal material. The working range of the oil seal is related to the material used for the oil seal: the material is nitrile rubber (-40~120°C), Aggreko rubber (ACM) -30~180°C, fluorine rubber (FPM) -25~300°C.
The choice between 55%, 80%, and 10% oil seals largely depends on the specific demands of the application. Engineers must consider factors like operating pressure, speed, temperature, and the type of fluid being sealed. The right selection can significantly enhance machine performance, reduce maintenance costs, and improve overall productivity.The main function of a shaft oil seal is to prevent the leakage of fluids and gases from the system