The seal shown in Fig. 14.2 is a relatively simple design; most automotive seals are more complex. Dust lips are often used to keep outside contaminants away from the oil lip seals; such seals thus have undercuts that make demolding more difficult. Fluoroelastomer compounds used for such undercut shapes must have reasonably high elongation at break at molding temperatures to avoid tearing the part during demolding. The metal insert is often U-shaped, and stock may be molded to form a thin layer over the outside of the insert. Since both compression and injection molding methods are used, suppliers of fluoroelastomers for shaft-seal applications often must provide different versions of the same polymer composition-medium to high viscosity for compression molding, and low to medium viscosity for injection molding. Different precompounds may be necessary to accommodate relatively long compression-molding times at low temperature and very short injection-molding times at high temperature.
What are Oil Seals and the different types?
• More compact thanks to the thin plate (uses a high-strength steel plate)
It is possible to get custom-made seals manufactured at reasonable rates from good-quality manufacturers if the readymade seal specification doesn’t meet the requirement.
Oil seals come in a vast range of materials and compounds. Even older materials, such leather, are still used today. Nitrile is among the most common materials for oil seals but is slowly losing ground to PTFE, which is gaining popularity due to its effectiveness in high-speed applications.
Construction of an Oil Seal
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.