Proper lubrication of all the moving parts is extremely important in engine operation. The function of the lubrication system is lubricating engine all friction surfaces of the parts, to reduce friction and wear between moving parts of the engine, to take away surfaces heat as well as debris left by worn part and to improve the sealing of cylinder.
There are meanwhile many functions in lubricating system, such as, lubricating, radiating, cleaning, anticorrosion, sealing, vibration reduction and hydraulic pressure.
- Oil pan
It is used for the storage of oil and sealed with combined surface of body in gasket and glue.
- Oil pump
It is used for the suction of the oil in the bottom shell and the force to each lubricating part in a certain pressure.
- Pressure limiting valve
Oil pump driven by the engine, the oil quantity increases and the oil pressure rise while the engine speed increasing. In order to avoid excessive pressure, a pressure limiting valve is provided in the oil path of lubrication. When the engine oil pressure exceeds the set number, the excess lubricating oil flow back into the oil sump after pressure limiting valve is opened.
- Oil passage
The main function of oil passage is to transport pressure oil pumped out by oil pump to the friction surfaces of various parts; oil channel is casted directly in the cylinder body and cylinder head or machining in some parts, which can be divided into the main oil path and the branch oil passage. The main oil passage generally refers to the oil channel which cast in the cylinder wall and is arranged longitudinally along the engine while others are divided oil.
- Oil filter
It is used for filtering impurities in the lubricating oil, which can be divided into the strainer, the coarse filter and the fine filter according to the different diameters of impurities that can be filtered and respectively link to the main oil passage in parallel way or series way.
- Oil radiator
Oil radiator is usually installed in the front of cooling-water radiator and connected with main oil channel in parallel way. While working, oil pump supplies oil for the main oil gallery, where the oil flow through the pressure limiting valve, the switch of oil radiator and oil pipe, then into the oil radiator and flow back into the oil pan from the oil pipe after cooling, flowing circularly in this way.