Aircraft engine oils are designed to lubricate engine moving parts under a wide range of operating temperatures. This reduces friction between engine moving parts which includes gears, bearings, camshaft, rocker arms, cylinder walls, and piston rings. Engine oil provides additional functionalities for engine cooling, cleanliness, and corrosion inhibition.
Aviation lubricants encompass a wide range of lubricating oils used in aircraft propulsion systems. The engine oil is specifically designed to lubricate and cool the engine mechanical system.
The engine components that are typically lubricated with engine oil include engine main shaft bearings, accessory drive gearbox components, and sump seals.
Lubricating oil is very important for the aircraft propulsion system, without oil all moving parts of the engine would wear out very quickly, and also generate unwanted heat. Oil forms a layer between the moving parts and reduces friction.
Principles of Engine Lubrication
The primary purpose of lubricating oil is to reduce friction between moving parts. Because liquid lubricants or oils can be circulated readily, they are used universally in aircraft engines.
In theory, fluid lubrication is based on the actual separation of the surfaces so that no metal-to-metal contact occurs. As long as the oil film remains unbroken, metallic friction is replaced by the internal fluid friction of the lubricant.
Functions of Engine Oil
- To reduce friction.
- The oil film acts as a cushion between metal parts.
- As oil circulates through the engine, it absorbs heat from the pistons and cylinder walls.
- The oil also aids in forming a seal between the piston and the cylinder wall to prevent leakage of the gasses from the combustion chamber.
- Oils clean the engine by reducing abrasive wear by picking up foreign particles and carrying them to a filter where they are removed.
- The oil also prevents corrosion on the interior of the engine by leaving a coating of oil on parts when the engine is shut down.