Hydraulic oil can generally be divided into two categories: ordinary oil and special oil.
1, mechanical oil:
Domestic machine oil is divided into 7 grades according to the kinematic viscosity at 50°C. The more commonly used ones are No. 10, No. 20 and No. 30. It is an industrial medium-quality lubricant, which is widely used in the lubrication of various machine tools and machinery. It is very common in hydraulic transmission. But the chlorination stability is poor, and it is often used in less demanding occasions. 2. Turbine oil (turbine oil): It has a high degree of oxidation resistance at high temperatures, and has high anti-emulsification properties. It has low acidity and ash content, 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 that of turbine oil
3, diesel engine oil:
The oil is added with anti-oxidation, anti-corrosion and engine cleaning additives, which has good lubricating performance. Generally used in hydraulic transmission systems of tractors, construction machinery and lifting and transporting machinery. No. 11 is commonly used in summer and No. 8 is commonly used in winter. The price is slightly higher than the first two oils.
In these ordinary oils, since no or very few special additives are added, foam is prone to occur during transmission. Large sound, poor viscosity and temperature (the smaller the viscosity change with temperature, the better). Especially the viscosity increases very quickly at low temperature, which is not suitable for use in low temperature occasions.
4, thickened hydraulic oil:
is a kind of special hydraulic oil newly trial-produced in our country in recent years. There are several grades of upper thick and blue thick: no formal standard has been established yet. It has low freezing point, good oxidation stability, good anti-rust and river slip performance. Because of the addition of thickener, the viscosity changes little with humidity; it is cold-resistant and can be used at low temperatures: less foaming during work, low noise , It can be used in hydraulic systems such as construction machinery, engineering machinery, hoisting and transporting machines.
5, precision machine tool hydraulic oil;
is a refined lubricating oil with additives such as anti-oxidation, anti-wear, anti-foam, anti-corrosion and improving viscosity and temperature. Good viscosity and temperature. It is suitable for the hydraulic system of precision machine tools, but cannot be used for low temperature.
6, aviation hydraulic oil:
is also called red oil because it is usually dyed red. It is a specially processed lubricating oil with additives to improve viscosity-temperature and lubricity. It has a low freezing point and good viscosity-temperature performance. It is widely used in empty hydraulic transmission systems. This kind of oil is suitable for low-temperature work, and has a lower viscosity at room temperature, but the price is more expensive (4-7 times the price of mechanical oil).
7, steering gear hydraulic oil:
is mainly used in the hydraulic system of ship steering gear.
8. Synthetic spindle oil:
It was formerly called special spindle oil. It has a very low freezing point, good lubricity and corrosion resistance. It is a high-grade oil, mainly used in hydraulic transmission, and the price is similar to that of steam turbine oil.
