Indispensable - What are the functions of lubricating oil?
author: Leila
2024-07-22
Lubricating oil is a liquid lubricant used in various types of machinery to reduce friction and protect machinery and processed parts. It mainly plays the role of lubrication, cooling, rust prevention, cleaning, sealing and buffering. Lubricating oil accounts for 85% of all lubricating materials. There are many types and brands. The current annual global consumption is about 38 million tons. The general requirements for lubricating oil are:
(1) Reduce friction and anti-wear, reduce friction resistance to save energy, reduce wear to extend the life of machinery and improve economic benefits; continuously deliver clean engine oil to the friction surface of the engine's running parts to form a good lubricating film (using friction between liquids instead of rolling or sliding friction between solids) for lubrication to reduce the movement and wear of the parts.
(2) Cooling: Due to the circulation of engine oil, part of the heat generated by friction can be taken away and dissipated, so as to reduce the temperature of the parts. It is required to discharge friction heat out of the machine at any time;
(3) Sealing, the engine oil layer between the piston and the cylinder wall can reduce air leakage during piston movement and increase the sealing between the piston and the cylinder wall. It is required to prevent leakage, dust and cross-flow;
(4) Anti-corrosion and anti-rust, requiring protection of the friction surface from oil deterioration or external erosion;
(5) Clean flushing can remove the metal chips from friction, keep the friction surface of the machine parts clean and reduce friction. It is required to clean and remove the scale on the friction surface;
(6) Stress dispersion and buffering, load dispersion and impact relief and shock absorption;
(7) Kinetic energy transmission, hydraulic system and remote control motor and friction stepless transmission, etc.
Under normal circumstances, engine oil will also be consumed. In a fundamental sense, there is no engine that absolutely does not consume engine oil. The reasons are as follows: 1. Engine oil is used to lubricate the piston, piston ring and cylinder. When the piston moves downward, it will leave a layer of oil film on the cylinder wall. When the vehicle decelerates, the high negative pressure generated will suck some of this engine oil into the combustion chamber. This engine oil, like some of the oil film left on the cylinder wall, is burned by the high-temperature combustion gas during the combustion process. 2. Engine oil is also used to lubricate the intake valve stem and is sucked into the combustion chamber. High-temperature exhaust gas will also burn the oil used to lubricate the exhaust valve. The following are factors that affect oil consumption: 1. Oil viscosity: The lower the viscosity of the oil, the worse its sealing effect, and the more oil is sucked into the combustion chamber. 2. Vehicle driving conditions: High-speed driving and frequent acceleration and deceleration will increase oil consumption. 3. During high-speed driving, the diluted components will evaporate, so excessive oil consumption will be found after high-speed driving. 4. Since the new engine has not been run-in, it will consume more oil. Toyota's maximum oil consumption during the running-in period is: maximum 1.0L (liter) / 1000km (kilometers).
From the above analysis, it can be seen that checking the oil level is one of the key items in daily vehicle maintenance. Another point is that the oil will become thinner due to the adsorption of water vapor during use, so it is difficult to correctly judge the actual oil level when judging the oil consumption. Therefore, even if the oil level is normal, we must change it regularly according to the mileage requirements. Finally, I recommend that you check the oil level every 1,000 kilometers at most. If conditions permit, it is best to check it every time you refuel.
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