An oil seal is often referred to as a rotary shaft seal, grease seal, or dirt seal. Oil seals are used to retain grease in a case or housing. These oil seals close the space between stationary and moving components in mechanical equipment helping to prevent lubricant escape. Oil seals are crucial because they prevent harmful contaminants from entering the machinery. These seals are one of the most popular dynamic seals. The oil seals cover high-speed rotating shafts and low pressure. Any place you find a bearing is used to support a rotating shaft, you can most likely see an oil seal to keep lubricating fluids in the system while keeping contamination out. These seals consist of rubber elastomer bonded to a metal can and usually have a garter spring that helps keep the lip against the shaft.
Oil Seals are typically installed adjacent to a bearing, sealing in or sealing out, as necessary, the various liquids, gases, or solids encountered by the particular mechanism. Some Oil Seals are split for easy installation. Split Oil Seals help to reduce downtime by not dismantling machinery. Split Oil Seals are recommended for horizontal shafts. Oil Seals typically have a single lip or a double lip. Oil Seals are generally the least expensive component, but they serve to be the most important because they protect the more expensive components such as the bearings and gears.
Regularly checking and replacing Oil Seals are a part of successful preventative maintenance.