Where is the oil pump for?

    Oil pumps are usually either inside the oil pan and driven by a camshaft or outside the pan and driven by a crankshaft. When those engine parts start moving, the pump starts working at the same time to pump oil to reduce friction and wear between moving parts and prevent the engine from seizing. An engine needs oil to lubricate moving parts, prevent corrosion, collect dirt and sludge, and absorb some of the heat generated by a running engine. The oil pump provides the force that delivers oil through galleries and passages around the engine. Oil pumps are usually either inside the oil pan and driven by a camshaft or outside the pan and driven by a crankshaft. When those engine parts start moving, the pump starts working at the same time to pump oil to reduce friction and wear between moving parts and prevent the engine from seizing. If an oil pump stops working, or there is little or no oil because of leaks, engine parts can overheat in a matter of seconds and seize from a lack of lubrication. Checking or replacing an oil pump is not part of routine service or maintenance, but because it’s critical to an engine any warning signs should be addressed immediately. An illuminated oil system warning light (usually red with the outline of a vintage oil can) or low-pressure indication on an oil pressure gauge are signs that the oil level is extremely low, the pump is not operating at normal speed or there’s a related problem that needs prompt attention. When a warning light comes on, the best approach is to shut the engine off, wait several minutes and check the oil level. If the oil level is normal and the warning light comes on again when the engine is restarted, continuing to run the engine increases the risk of major damage.

1.Lubrication system
   The lubrication system has two basic functions: to lubricate the compressor's moving components and to cool the system by removing heat from the compressor's moving parts. While all compressors must have a lubrication system, the actual design and function of these systems will vary depending on compressor type.

   The lubricating system for centrifugal or dynamic compressors is designed to provide bearing lubrication. In smaller compressors, the lubrication systems may consist of individual oil baths located at each of the main shaft bearings. In larger compressors, such as a bullgear design, a positive system is provided to inject oil into the internal, tilting-pad bearings located at each of the pinion shafts inside the main compressor housing. In positive lubrication systems, a gear-type pump is normally used to provide positive circulation of clean oil within the compressor. In some cases, the main compressor shaft directly drives this pump. In others, a separate motor-driven pump is used. Positive displacement compressors use their lubrication system to provide additional functions. The lubrication system must inject sufficient quantities of clean fluid to provide lubrication for the compressor's internal parts, such as pistons and lobes, and to provide a positive seal between moving and stationary parts. The main components of a positive displacement compressor's lubrication system consist of an oil pump, filter, and heat exchanger. The crankcase of the compressor acts as the oil sump. A lockable drain cock is installed at the lowest end of the crankcase to permit removal of any water accumulation that has resulted from sweating of the crankcase walls. The oil passes through a strainer into the pump. It then flows through the heat exchanger, where it is cooled. After the heat exchanger, the cooled oil flows directly to the moving parts of the compressor before returning to the crankcase sump. A small portion is diverted to the oil injector if one is installed. The oil that is injected into the cylinder seals the space between the cylinder wall and the piston rings. This prevents compressed air from leaking past the pistons, and thus improves the compressor's overall efficiency.

1.2 Oil separator
    The basic purpose of an oil separator is to clean the pressurized air of any oil contamination, which is highly detrimental to pneumatically controlled instrumentation. A separator consists of an inlet, a series of internal baffle plates, a wire mesh screen, a sump, and an outlet. The pressurized air enters the separator and immediately passes through the baffle plates. As the air impinges on the baffle plates it is forced into making sharp directional changes as it passes through each baffle section. As a result, the oil droplets separate from the air and collect on the baffles before dropping into the separator's sump. After the air clears the baffle section, it then passes through the wire mesh screen where any remaining oil is trapped. The relatively oil-free air continues to the air reservoir for storage. The air reservoir acts as a final separator where moisture and oil is eventually removed. The air reservoir has drain traps installed at its lowest point where any accumulated moisture/oil is automatically discharged.