Early engines used O-rings (also called packing rings or toric joints) as seals (first patented in 1896). These are just mechanical gaskets in the shape of a torus (a circular ring--like a lifesaver), seated in a groove and compressed during assembly between two or more parts. It creates a seal at the interface. However, O-rings require a fluid film to lubricate them. They have limited usefulness in vacuum application and at extremes of temperature. The modern oil seal represents a significant improvement over the simple O-ring because it effectively seals in lubrication and prevents contamination from outside under a wide range of pressures and temperatures.

Oil Seal Buying Guide

Installation techniques must be carefully selected and executed to ensure the seal functions correctly throughout its service life. Each technique addresses specific installation needs and ensures long-term reliablity.

Hub Oil Seal: Significance in Automotive and Industrial Applications

One of the key benefits of floating oil seals is their ability to provide a secure and reliable seal even in high-pressure environments. Unlike traditional seals that rely on compression to create a seal, floating oil seals utilize a unique design that allows them to float on the oil and adjust their position as needed to maintain an effective seal. This design not only enhances the reliability of the seal but also helps to prolong the lifespan of the seal by reducing wear and tear.

Before fitting the oil seal, it is essential to check that the oil seal, shaft and bore are clean and undamaged. The surfaces the oil seal will come into contact with must be free of sharp points or burrs. The sealing lip is fragile, so even minimal damage can cause a leak. It is also important that the shaft and bore are correctly finished.