Do you know these functions of engine oil?
Many friends know that the engine oil needs to be changed when the vehicle is maintained, but many people don’t know what the function of engine oil is and how to choose engine oil. Today, Xiao Jia will introduce you to the knowledge about engine oil!
Automobile lubricating oil can be generally divided into three types because of its different functions: engine oil, gearbox and differential oil, and grease (butter). The most common thing in vehicle maintenance is to change the engine oil.
Engine oil has five functions.
Lubrication function: the function of engine oil is to fill and lubricate the surfaces of moving parts and reduce the friction between moving parts. Its working principle is: the engine oil is pressurized by the oil pump and transported between the rotating parts, and an oil film is formed on the two friction surfaces to separate them, thus reducing the contact surface between moving parts, thus reducing wear and prolonging the service life of parts. There is surface friction between piston and cylinder, crank-connecting rod mechanism, cam valve train, gear rotating mechanism, etc., which must be lubricated by engine oil to ensure normal working conditions.
Cooling function: engine oil can bring back part of the heat generated between the rotating parts of the engine to the oil pan, and achieve the cooling effect through the oil pan wall. Some engines are also equipped with special engine oil radiators to achieve better cooling effect, so as to ensure the normal temperature between the rotating parts of the engine and keep the engine in normal working condition for a long time.
Sealing function: The engine oil also has a sealing function. For example, the engine piston ring and the cylinder wall are filled with engine oil, so that the contact surface and the gap have both a lubricating function and a sealing function, so that the piston can reduce air leakage when inhaling and compressing, and ensure the normal working compression ratio. If the piston ring and cylinder wall are worn, the sealing effect of engine oil can be improved by adjusting the viscosity of engine oil or adding engine oil additives, thus improving the working condition of the engine.
Cleaning function: The engine oil is pressurized by the oil pump and transported between the rotating parts of various parts for lubrication and heat dissipation. At the same time, it can also wash and clean the rotating working surface of the parts, bring the dust particles entering the engine and the garbage generated by the work to the oil pan, and keep the engine parts, rotating working surface and oil passage clean and smooth through the oil collection net and oil filter, thus ensuring the normal operation of the engine.
Rust-proof function: The working environment of the engine is complicated, and the climate change in spring, summer, autumn and winter will easily cause the metal parts to rust and deform, which will affect the normal operation of the engine and shorten its service life. The oil is pressurized by the oil pump and supplied to all parts and metal surfaces through the oil passage to form an oil film to isolate the air, which can prevent the metal surface from oxidation and rust and improve the service life of the engine.
If the engine is likened to the heart of a car, then the engine oil is the blood of the engine, which is a necessary condition to ensure the normal operation of the engine. Understanding the knowledge of engine oil, correctly selecting and using engine oil, and regularly replacing and maintaining it are very important to ensure the normal operation of the engine and prolong its service life.
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Written by Yang Chen, video.
Editor: Wang Lihui, Wu Lirong