Main functions of engine oil
1. Lubrication: there is rapid relative sliding between piston and cylinder, and between spindle and bearing bushing. In order to prevent the parts from wearing too fast, it is necessary to establish an oil film between the two sliding surfaces. There is an oil film with sufficient thickness to separate the surfaces of relatively sliding parts, so as to achieve the purpose of reducing wear.
2. Auxiliary cooling: Because the specific heat value of engine oil is low, and it has no cooling effect inside the engine. However, due to the heat generated by fuel combustion in the engine, when the engine is working, the engine oil can bring the heat back to the engine oil tank and then radiate it into the air to help the water tank cool the engine. What really plays a cooling role is the water (or antifreeze) outside the engine shell.
3. Cleaning: Good engine oil can bring carbides, sludge and worn metal particles on engine parts back to the oil tank through circulation, and wash away the dirt generated on the working surface of the parts through the flow of lubricating oil.
4. Sealing and leak-proof: Engine oil can form a sealing ring between the piston ring and the piston to reduce gas leakage and prevent external pollutants from entering.
5. Rust prevention and corrosion protection: Lubricating oil can be adsorbed on the surface of parts to prevent water, air, acidic substances and harmful gases from contacting with parts.
6. Shock absorption and buffering: When the engine cylinder pressure rises sharply, the load on the piston, piston plate, connecting rod and crankshaft bearing suddenly increases, and this load is lubricated through the bearing, so that the impact load it bears plays a buffering role.
7. Anti-wear: Adding lubricant to the friction surface can reduce the friction coefficient, thus reducing the friction resistance, saving energy consumption and reducing wear: the lubricant between the friction surfaces can reduce the wear caused by abrasive wear, surface fatigue and adhesive wear.
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