Refrigerator compressors typically use a type of lubrication system known as "splash lubrication" to ensure proper lubrication of moving parts. This system does not require an oil pump but relies on the design and movement of the compressor components to distribute oil effectively.
Here's how splash lubrication works in a refrigerator compressor:
Oil Sump: The compressor contains an oil sump, which is a reservoir at the bottom of the compressor housing. This sump holds an adequate amount of lubricating oil to ensure a continuous supply throughout the compressor.
Rotating Components: Within the compressor, there are rotating components such as the crankshaft and connecting rods. These components dip into the oil sump as they rotate.
Oil Splashing: As the crankshaft and connecting rods rotate, they dip into the oil sump during their movement. When they come in contact with the oil, they pick up a thin film of lubricating oil on their surfaces.
Oil Distribution: Once the rotating components have picked up the oil, they carry the oil film with them as they move upward. When the crankshaft and connecting rods reach the upper portion of their cycle, the momentum causes the oil to splash onto other parts of the compressor, such as the piston walls and cylinder walls.
Lubrication: The splashed oil forms a thin lubricating film on various moving parts of the compressor, including the piston, cylinder, and other critical components. This film reduces friction and wear, ensuring smooth operation and extending the life of the compressor.
The key to effective splash lubrication is the careful design of the compressor's internal components and their motion to ensure adequate oil distribution to all critical areas. Proper oil viscosity and quality are also essential for maintaining an efficient lubrication process.
While splash lubrication is a common and effective method for small to medium-sized refrigeration compressors, larger compressors used in industrial applications might utilize more sophisticated lubrication systems, such as forced lubrication with an oil pump, to ensure reliable and consistent lubrication under higher loads and more demanding conditions.