The layout of the elements of the lubrication system of engines 3S-GE, 4A-FE, 7A-FE: 1 - oil pump, 2 - oil intake, 3 - pressure reducing valve, 4 - oil filter, 5 - oil cooler, 5 - oil cooler.
These engines use a full-flow oil cleaning lubrication system with pressurized oil supply to the main moving parts and assemblies of the engine. The lubrication system includes: an oil sump, an oil pump, an oil filter and various elements that provide oil to various moving parts of the engine. Oil from the sump is pumped into the oil filter through the oil intake by an oil pump. Part of the oil immediately after the oil pump is sent to the oil cooler.
After passing through the oil filter, part of the oil is fed through various channels in the cylinder block and through the holes to the crankshaft main bearings. Oil flows through the holes in the crankshaft to the connecting rod bearings of the crankshaft. The lubrication of the cylinder walls and the lower part of the piston crown is carried out mainly by spraying. For lubrication of the piston pin, a special hole is provided in the piston head of the connecting rod and in the piston pin bushing.
Part of the oil after passing through the oil filter through the drillings in the cylinder block is sent to the cylinder head for lubrication:
- the driven gear of the intake camshaft;
- camshaft journals:
- cams;
- valve lifters and valve stems;
- exhaust camshaft drive gear;
After performing its functions, the oil under the action of gravity (by gravity) returns to the tray.
To control the oil level in the crankcase, a dipstick is installed on one side of the oil pump housing.
Oil pump
The oil pump takes oil from the engine sump through the oil receiver and delivers it under pressure to various friction units. An oil receiver with a strainer is located in front of the oil pump inlet pipe. The oil pump itself is a three-way pump. Inside it are the driving and driven rotors with internal gearing, which rotate in the same direction. Since the axes of the male and female rotors are offset from each other, the space between both rotors changes as they turn. Oil is sucked into the pump when the space between the rotors expands and swept when the space between the rotors narrows.
Oil pressure regulator (pressure reducing valve)
At high speeds, the amount of oil supplied by the oil pump is excessive compared to the amount necessary to lubricate the rubbing pairs. Oil pressure regulator (pressure reducing valve) prevents excess oil supply. At low speeds, the regulator valve closes the bypass channel under the action of a spring. But at high speeds, the oil pressure rises sharply, the oil pressure force overcomes the spring force, and the regulator valve opens. Excess oil returns to the sump through the valve.
Oil filter
The oil filter is a full-flow type with a replaceable paper filter element. metal particles (wear products), airborne dirt particles, carbon particles and other types of contaminants can enter the oil during use, resulting in increased engine wear or clogging (channel narrowing) oil lines, preventing oil circulation. An oil filter installed in the oil line allows these particles to be trapped as the oil passes through it. The filter is installed on the outside of the engine, which makes it relatively easy to replace the filter element. A bypass valve is installed in front of the filter element, which opens with an increase in pressure in front of the filter, which occurs if the filter element is clogged with contaminants. The bypass valve opens when the oil pressure force exceeds the force of the valve spring. In this case, the oil passes through the bypass channel, bypassing the oil filter, and is directed directly to the main engine oil line.