What are the characteristics of internal combustion engine oil?

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What are the characteristics of internal combustion engine oil?

Internal combustion engine oil is also called motor oil and engine oil. It is a kind of lubricating oil which is mainly composed of mineral base oil or synthetic base oil, and modulated by adding additives such as cleaning and dispersing agents and antioxidant and anti-corrosion additives.

Internal combustion engine oil is in the more loaded conditions of work, for example, the piston ring on the cylinder wall of the friction speed is very large (large engines in 3500 ~ 4000r/min for 10 ~ 12m/s, small engines in 3800 ~ 4000r/min for 9 ~ 11m/s), and the engine combustion chamber temperature changes in a wide range, from -35 ℃ (winter start) to Above 2200℃ (during combustion). Therefore, it requires the following main properties:

① Viscosity and viscosity-temperature properties

Viscosity and viscosity-temperature property is one of the important properties of internal combustion engine oil. The viscosity of internal combustion engine oil is mainly determined by the maximum viscosity for low-temperature start-up and the minimum viscosity that can maintain the oil film under high-temperature shear. The viscosity of the oil flow performance is generally bad, so that after the start of the friction surface for a long time without adequate lubrication; viscosity is too small, the oil film is easy to destroy, sealing effect is not good, the oil consumption increases, but also produce wear.

Internal combustion engine oil viscosity must take into account the better high temperature and low temperature viscosity, that is, the oil has a good viscosity and temperature performance. Good viscosity and temperature properties of the oil, can maintain satisfactory startup, the correct oil cycle and high temperature to keep the engine from being worn.

② clean dispersion performance

Internal combustion engine oil cleaning and dispersing performance is mainly to solve and inhibit the oxidized colloid in the oil and carbon generation or removal, so that it is suspended in the oil, not easy to deposit on the parts; and the original deposits on the parts of the deposits can be washed down, suspended in the oil, through the filter will be filtered out to avoid the tendency to reduce the piston varnish and carbon generation.

③Antioxidant property

Internal combustion engine oil in the use of conditions, due to temperature, air and metal catalytic effect, the oil is often easy to oxidize and deteriorate. Oil oxidation generates acidic compounds, easy to corrode engine parts. Oxidized substances will be further oxidized to generate macromolecules of gelatinous and asphaltene substances, so that the viscosity of the oil increases affecting the normal use.

④Anti-wear performance

Internal combustion engine oil wear resistance and oil viscosity and viscosity properties, clean dispersion and corrosion resistance and other properties. The main factor affecting anti-wear performance is the engine operating conditions, the lubricant in the metal surface to maintain the ability of the oil film. Good lubrication performance can ensure reliable lubrication of machine parts, to avoid wear and tear of machine parts. Otherwise, when the engine load increases, the oil film is destroyed, thus forming dry friction, resulting in wear and abrasion of machine parts, and even sintering.

Gasoline engine oil and diesel engine oil due to the structure and working conditions are different, diesel engine load, low speed, for compression ignition, gasoline engine speed is high, for ignition. Therefore, the performance of gasoline engine oil and diesel engine oil is naturally different, gasoline engine oil pays more attention to high-temperature oxidation resistance and anti-wear performance, while diesel engine oil pays more attention to cleaning and dispersing performance, acid-neutralizing ability and corrosion resistance.