Engine Lubrication System Construction

The purpose of engine lubricating system is oil supply to the rubbing surfaces of the engine parts, that reducing friction between them. This in turn allows you to reduce the loss of engine power for overcome friction. During engine operation motor oil is circulation between the engine details, provide cooling and save them from wearing. It`s need note that oil layer on the piston do the better engine compression.

Lubrication system in automobiles

Automobile engines have combined lubrication system. In this case, especially loaded engine parts, such as main and connecting rod bearings of the crankshaft, camshaft bearings, rocker arms and other parts are lubricating under pressure.  And other parts are lubricated by splashing oil in engine.

It`s need to note that lubrication by pressure is produced some methods: continuous or pulsating supply of engine oil to the rubbing surfaces.  

Lubrication system construction

Lubrication system consists of lubrication pump 3 (which is inside the crankcase 22), lube oil filter 17,   main oil lines 6 with channels, oil cooler 8, oil filler neck with cap 9, oil level gauge  26 and others parts.

How an engine lubrication system works

The lubrication pump is driven by a camshaft using two gears. The gear is made integrally with the camshaft, and the wheel is mounted on the intermediate shaft of the lubrication pump drive. By engine operation the oil from the crankcase 22 is running by the pump through the oil receiver 2 and pumped into the filter 17.

Lubrication System Construction

Lubrication System Construction

1 and 18 – oil drain plugs; 2 – oil receiver; 3 – lubrication pump; 4 – oil pressure relief valve; 5 – crankshaft; 6 – main oil line; 7 – camshaft; 8 – oil cooler; 9 – oil filler neck with cap; 10 – rocker arm; 11 – engine block cover; 12 – engine block head; 13 – valve; 14 – valve push rod; 15 – push rod; 16 – oil pressure gauge;   17 – oil filter; 19 – oil pressure sensor; 20 – limit valve; 21 – oil cooler tap; 22 – oil pan; 23 – connecting rod hole; 24 and 25 – oil channels; 26 – oil level gauge;  27 – oil groove; 28 and 32 – oil drainage channels; 29 – plug; 30 – crankshaft oil channel; 31- dirt traps; 33 – tube for gear wheels lubrication; 34 – grooves on the camshaft neck; 35 – camshaft gear wheel; 36 – crankshaft gear wheel.

The oil enters the oil line passed the filter, and from the oil line is moving through the transverse channels in the cylinder block. Then oil is supplied to the crankshaft main bearings 5 and the camshaft bearings.

There are drilled holes for the passage of oil to the main necks of the crankshaft in the upper bearing bushes of the main bearings.  Oil distribution grooves are made on the main bearing shells, constantly communicating with the channels 30 drilled in the cheeks, through which oil flows from the main journals to the crankpin journals. There are dirt traps 31 for additional oil centrifugal cleaning in the crank pin journals of the crankshaft. After that, the oil enters to the mating crank pin of the crankshaft – the connecting rod bearing.

Some engines have the small holes 23 are made in the lower heads of the connecting rods. Pulsating oil flow is supplied to the cylinder walls or camshaft cams through them (when they coincide with the holes in the connecting rods of the crankshaft).

The rocker arms 10 and upper valve push rod are also lubricated by a pulsating flow. The fifth camshaft journal has an annular groove. When the shaft rotation, this groove connects the vertical channel 25 to the channel in the cylinder block. The oil enters the channel 24 of the head engine block 12 from the channel 25. Also there is a hole through which oil is supplied to the rocker arm. Oil is supplied to the upper tips of the rods through the channels in the short arms of the rocker arm. Flowing down the rods, the oil lubricates their lower tips, pushers 15 and cams of the camshaft, and then flows into the oil pan. The oil is sprayed up by the rotating parts of the crank mechanism, forming an oil mist. There is a hole in the cylinder front end of the block into which the tube 33 was inserted. By the camshaft rotates, oil enters through the groove 34, the tube 33 to the camshaft gear wheels 35 and 36.

Valves of engine lubrication system

There are three valves in engine lubrication system: oil pressure relief valve 4 (located in lubrication pump cap), regulator valve, limit valve 20.