Lubrication system is generally composed of oil sump, oil pump, pressure limiting valve and bypass valve, oil filter, oil cooler, sensor and oil pressure gauge, thermometer and so on.  

 

 

Lubrication: The surface of moving parts is lubricated to reduce friction resistance and wear, as well as reduce the power consumption of the engine.  

Cleaning: The oil circulates continuously in the lubrication system to clean the friction surface and take away the dust and other foreign matter.  

Cooling: The oil circulates in the lubrication system to take away the heat generated by friction and play a cooling role.  

Sealing: The oil film is formed between moving parts to improve their sealing property, which is conducive to preventing air leakage or oil leakage.  

Anti-rust: The oil film is formed on the surface of parts to protect the surface of parts and prevent corrosion and rust.  

Hydraulic function: Lubricating oil can be used as hydraulic oil for hydraulic functions, such as hydraulic tappets.  

Shock absorption and buffering: The oil film is formed on the surface of moving parts to absorb shock and reducing vibration, playing a shock absorption and buffering role.  

 

 

Pressure lubrication: through the use of oil pump, the lubricating oil with a certain pressure will be continuously sent to the friction surface. For example, The oil film is formed at main crankshaft bearing, connecting rod bearing and camshaft bearing, rocker arm and so on to ensure lubrication.  

Splash lubrication: it refers to make use of oil droplets or oil mist splashing from moving parts when the engine is working to lubricate the friction surface, which can lubricate the cylinder wall bearing lighter load on the outside, the piston pin with relatively small sliding speed, the cam surface & the tappets of the valve distribution mechanism and so on.  

 

Regular lubrication: for engine auxiliary devices with small load, only regular and quantitative lubricating grease is required, such as water pumps and generator bearings. It does not belong to the working category of lubrication system. In recent years, bearings containing wear-resistant lubricating materials (such as nylon, molybdenum disulfide, etc.) have been used in engines to replace bearings filled with grease.  

 

Types of lubricants: lubricating oil and lubricating grease  

 

1. Types of lubricating oil in China:  

(1) Lubricating oil for gasoline engine: SC, SD, SE, SF, SG, SH  

(2) Lubricating oil for diesel engine: CC, CD, CD-II, CF, CF-4  

 

2. Types of grease: calcium base lubricating grease, sodium base lubricating grease, calcium and sodium base lubricating grease, complex calcium base lubricating grease, general lithium base lubricating grease, graphite calcium base lubricating grease.