Õlitihends

Õlitihends, often translated as oil seal or grease seal, are mechanical components used to retain lubricant within a housing while preventing the ingress of contaminants. They are typically found in rotating or reciprocating machinery where shafts pass through a casing. The primary function of an oil seal is to create a barrier that prevents oil or grease from escaping and to keep dirt, dust, water, and other impurities from entering the lubricated area.

The most common type of oil seal consists of a flexible lip made from a synthetic rubber material, such as nitrile rubber (NBR), silicone rubber (VMQ), or fluoroelastomer (FKM). This lip is designed to press against the moving shaft with a controlled amount of interference. The elasticity of the rubber ensures that the lip maintains contact and seals effectively even as the shaft rotates or reciprocates. Many oil seals also incorporate a metal casing or outer shell, which provides rigidity and facilitates installation by allowing the seal to be pressed into its housing. Some designs may include a garter spring behind the lip to maintain consistent sealing pressure, especially under varying temperature and pressure conditions.

Oil seals are critical for the longevity and performance of many mechanical systems, including engines, transmissions, gearboxes, pumps, and bearings. By preventing lubricant loss, they ensure proper lubrication of moving parts, reducing friction and wear. Simultaneously, by excluding contaminants, they protect sensitive components from damage and premature failure. The selection of an appropriate oil seal depends on factors such as the operating temperature, the type of lubricant, shaft speed, pressure, and the environment in which the machinery operates.