Oil gets into an air compressor in a few primary ways, depending on the type of compressor. The most common reason is because oil is deliberately injected into the compression chamber in oil-lubricated compressors to lubricate and seal the moving parts. Let's break down the reasons:
Oil-Lubricated Air Compressors: Intentional Injection
In oil-lubricated air compressors, oil serves a crucial role:
- Lubrication: Oil reduces friction between the piston, cylinder walls, and other moving parts, minimizing wear and tear.
- Sealing: The oil helps create a tighter seal between the piston rings and cylinder walls, preventing air leakage and maintaining compression efficiency.
- Cooling: The oil absorbs heat generated during compression, preventing overheating and damage.
During operation, oil is pumped or splashed into the compression chamber where it mixes with the air being compressed. After compression, a separator removes most of the oil before the compressed air exits the system.
Oil-Free Air Compressors: Malfunctions Lead to Oil Contamination
While "oil-free" compressors are designed to operate without oil in the compression chamber, oil contamination can still occur due to:
- Seal Failure: If the seals around the crankshaft or other lubricated components fail, oil can leak into the compression chamber.
- Overfilling: Adding too much oil to the crankcase can cause it to splash or seep into the compression area.
- Improper Maintenance: Neglecting regular maintenance, such as replacing worn seals or filters, can increase the risk of oil leaks.
Common Entry Points for Oil Leaks in All Compressors:
Whether an oil-lubricated compressor is leaking excessively or an oil-free compressor has oil where it shouldn't, consider these areas:
- Crankcase Seals: Worn or damaged seals around the crankcase are a primary source of leaks.
- Cylinder Head Gasket: A faulty cylinder head gasket can allow oil to seep into the compression chamber.
- Air Filter: A saturated or damaged air filter can allow oil mist to be drawn into the system.
- Hoses and Fittings: Loose or damaged hoses and fittings can leak oil.
Addressing Oil in Your Air Compressor
If you find excessive oil in the output air of an oil-lubricated compressor, or any oil in the output air of an oil-free compressor, it's essential to:
- Identify the source of the oil.
- Repair or replace the faulty components.
- Maintain the compressor according to the manufacturer's recommendations.
By understanding how oil can get into your air compressor and taking proactive measures, you can ensure optimal performance and longevity.
