Hydraulic oil can generally be divided into two categories: ordinary oil and special oil.
1. Mechanical oil:
Domestic machinery oil is divided into 7 grades according to 50°C kinematic viscosity.The more commonly used ones are No. 10, No. 20 and No. 30.It is an industrial medium-quality lubricating oil and is widely used in the lubrication of various machine tools and machinery. The application in hydraulic transmission is very common. However, the stability of chlorination is poor, and it is often used in occasions with low requirements. 2. Turbine oil (turbine oil): It has high oxidation resistance at high temperature and high emulsification resistance. It has low acidity and ash, no mechanical impurities, and is purer than mechanical oil. It is generally used in hydraulic systems with higher requirements. The price is about 1/3~1/2 more expensive than mechanical oil.
2. Transformer oil:
It is a highly refined oil with no mechanical impurities, low acidity and low ash content, and has a high degree of oxidation resistance. The price is similar to steam turbine oil
3. Diesel engine oil:
Oil is added with anti-oxidation, anti-corrosion and engine cleaning additives, with good lubricating performance. It is generally used in the hydraulic transmission system of tractors, construction machinery and lifting transportation machinery. No. 11 is commonly used in summer and No. 8 in winter. The price is slightly higher than the first two oils.
Above these ordinary oils, because no or few special additives are added, it is easy to generate foam during transmission. The sound is loud and the viscosity and temperature are poor (the smaller the viscosity changes with temperature, the better). Especially at low temperatures, the viscosity increases rapidly, and it is not suitable for low temperature applications.
4. Thickened hydraulic oil:
is a kind of special hydraulic oil newly trial-produced in my country in recent years. There are several grades of super thick and blue thick: no formal standard has been formulated yet. It has low freezing point, anti-oxidation stability, good anti-rust and river slip performance. Due to the addition of thickener, the viscosity changes little with humidity; cold resistance, can be used at low temperature: less foaming during work, less noise , Can be used in hydraulic systems of construction machinery, construction machinery, hoisting conveyor maple and so on.
5. Precision machine tool hydraulic oil;
is a refined lubricating oil with additives such as anti-oxidation, anti-wear, anti-foam, anti-corrosion and improved viscosity and temperature. Good viscosity and temperature. Suitable for the hydraulic system of precision machine tools, but not for low temperature.
6. Aviation hydraulic oil:
is usually called red oil because it is usually dyed red. It is a specially processed lubricating oil with additives to improve viscosity temperature and lubricity. The freezing point is low and the viscosity temperature performance is very good. It is widely used in empty hydraulic transmission systems. This oil is suitable for low temperature work, the viscosity is lower at room temperature, but the price is more expensive (4 to 7 times the price of mechanical oil).
7. Servo hydraulic oil:
is mainly used in the hydraulic system of ship steering servo.
8. Synthetic spindle oil:
Formerly known as special spindle oil, it has a very low freezing point, good lubricity and corrosion resistance, is a high-grade oil, mainly used in hydraulic transmission, the price is similar to steam turbine oil.
