oilsealed

Oilsealed, often written with a hyphen as oil-sealed, refers to systems and components that rely on oil to create a seal and provide lubrication at moving interfaces. The term is used for oil-sealed bearings, oil-sealed vacuum pumps, and other seals in which an oil film or oil-filled chamber forms a barrier to gas flow while keeping surfaces lubricated.

In oil-sealed bearings, a thin film of oil between bearing surfaces reduces friction and prevents metal-to-metal contact. The oil also acts as a barrier against contaminants. In oil-sealed vacuum pumps and similar devices, oil is circulated through the pump housing, and oil vapor and oil films help restrict backflow of air and maintain lubrication under differential pressures. Seal designs may combine oil with labyrinth seals or gaskets to improve leakage control.

Common applications include vacuum technology (oil-sealed rotary vane and scroll pumps), gearboxes and pumps used in chemical and petroleum processing, and machinery that operates under moderate vacuum or high lubrication demands. Maintenance typically involves monitoring oil cleanliness, changing oil at intervals, and repairing or replacing seals that show wear.

Advantages of oil-sealed designs include effective sealing at low to moderate pressures, good lubrication, and relatively simple construction. Disadvantages include the potential for oil leaks, oil contamination of the process fluid, environmental concerns, and the need for regular oil maintenance and disposal.

Related concepts include oil seals and shaft seals, oil-lubricated bearings, and vacuum pump technology.