Onboard ships, lubrication is required for all types of equipment. The main engine lube oil pump is in charge of lubricating and cooling the internal components of the engine, which are in contact with each other, causing friction and heat, resulting in part overheating. Lubrication not only keeps things cool but also keeps dirt and pollutants out.
There are several tanks, coolers, and other equipment for the main engine lube oil pump system in ships. The schematic of the ship’s main engine lubricating system is shown below.
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Main Engine Sump Tank / Drain Tank
The main engine lubricating oil sump is a big chamber enclosed by cofferdams where the lubricant is stored. It is in a double bottom underneath the main engine, below the crankcase. Nowadays, submersible pumps are used, which are immersed in the oil and directly draw suction from the sump tank. After being circulated in the main engine, the lubricating oil returns to the main engine sump through a perforated plate and tiny magnets.
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Submersible Pumps for Main Engine Lubrication
The lubrication oil system is made up of two screw pumps that distribute lubricating oil to all of the engine’s components. Lube oil is sent from the distribution manifold to different working components of the engine, such as bearings, guides, under piston space, hydraulic power supply unit, and so on.
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Auto Backwash Filter
The Automatic Backflush filters efficiently separate pollutants according to size when used in combination with a centrifugal separator as part of the main engine lube oil pump system or fuel oil treatment system. Backflushing helps prevent residual particles from adhering to filter surfaces. Long service intervals are ensured, and manual cleaning, filter replacement, and filter disposal expenses are greatly reduced.
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Main Engine Lube Oil Cooler
Filters for marine lubricant oil are installed right after the pumps, on the discharge side. They are in a place to keep even the tiniest particles out of the system. The cooler has a bypass valve because if the lube oil temperature at the pump is already low, the lube oil is bypassed, which means it does not flow through the cooler.
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Distribution Manifold
After passing through the lube oil cooler, the lubricating oil is sent to the distribution manifold, where it is dispersed to all of the engine’s components. A telescopic pipe transports the majority of the lubricating oil to the crosshead. Oil is routed from the crosshead to the under piston space, guides, and crosshead bearings. It now travels from the connecting rod’s drillings to the bottom end bearing.
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Cylinder Oil Storage Tank
Cylinder lubricating oil is stored in two different tanks on board. To mitigate the acidic effects of sulfuric oxides created as a by-product of the combustion process, lubricating oil with high alkalinity is employed against fuel oil with high sulphur content.
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Cylinder Oil Daily Tank
The main engine lube oil pump flows from a cylinder oil storage tank into a cylinder oil daily tank depending on daily lube oil use. There is no inadvertent or automated lube oil filling since the lube oil is filled using a manual valve.
Having a daily tank allows you to keep an eye on the amount of lubricant oil you use daily. Furthermore, it is the same tank that delivers, purifies, and stores lubricant oil.
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Cylinder Oil Lubricator
The cylinder oil lubricator must inject lubricant into the groves/quills on the liner body. By creating a “W” shape, these grooves in the shape of quills provide for equal dispersion of lubricating oil.
The lubricating oil is given twice in the cylinder throughout a full rotation of the crankshaft. Once when the piston descends and once as it ascends. The engine’s speed or load determines the quantity of lubricating oil required.
