Motor Oil: What Requirements Do You Need To Meet?
Automobile motor oil circulates in the lubrication system, and the number of cycles can reach 100 times per hour. The working conditions of the oil are very bad. During the cycle, the oil is in constant contact with the high-temperature metal wall and air, and it is oxidized and deteriorated. The fuel vapor, exhaust gas, metal scraps and carbon deposits in the crankcase are severely contaminated. In addition, the working temperature of the oil varies widely: the ambient temperature at the start of the motor; the average temperature of the oil in the crankcase can reach 95 ° C or higher during normal motor operation. At the same time, the oil is also in contact with high temperature parts of 180 to 300 ° C and is heated intensely. What are the characteristics of motor oil to meet the harsh environment? Eaton Char-lynn Motor Description
1) Appropriate viscosity
The viscosity of the oil has a great influence on the operation of the motor. The viscosity is too small, it is easy to be lost from the friction surface under high temperature and high pressure, and the oil film of sufficient thickness cannot be formed; if the viscosity is too large, the cold start is difficult, and the oil cannot be pumped to the friction surface. The viscosity of the oil changes with temperature. The temperature rises and the viscosity decreases; the temperature decreases and the viscosity increases.
2) Excellent oxidation stability
Oxidation stability refers to the ability of an motor oil to resist oxidation without permanently changing its properties. When the oil is oxidized by contact with oxygen in the air during use and storage, the color of the oil becomes dark, the viscosity increases, the acidity increases, and colloidal deposits are generated. Oxidatively deteriorated oil will corrode motor parts and even damage the motor.
3) Good corrosion resistance
The oil is inevitably oxidized during use to form various organic acids. Such acidic substances have corrosive effects on metal parts, which may cause spots, pits or peeling of the alloy layer on the surface of the bearing such as copper lead and cadmium nickel.
4) lower foaming
As the oil circulates and splashes quickly in the lubrication system, foam is inevitably generated. If there is too much foam, or if the foam cannot be quickly removed, it will cause insufficient oil supply to the friction surface. The method of controlling foam formation is to add a foam inhibitor to the motor oil.
5) Strong clean dispersion
The clean dispersibility of the oil refers to the ability of the oil to disperse, loosen and remove the carbon deposits and dirt attached to the surface of the part. In order to have a clean dispersion of the oil, it is necessary to add a clean dispersing additive.
6) High extreme pressure
The lubrication state between the friction surfaces of the oil film is less than 0.3 to 0.4 μm, which is called boundary lubrication. It is customary to lubricate the boundary under high temperature and high pressure, which is called extreme pressure lubrication. The anti-wear properties of motor oil under extreme pressure are called extreme pressure.