Correctly select the basic requirements for hydraulic oil in hydraulic machines

    Hydraulic press, no matter which series of hydraulic press, hydraulic press, press as a hydraulic press manufacturer for so many years, Taizhou Rongmei Hydraulic Machinery Manufacturing Co., Ltd. will explain to you the selection of hydraulic oil for hydraulic presses. Practice has shown that the reasonable and correct selection of hydraulic oil is of great significance for ensuring the working performance of the hydraulic system, extending the service life of the system and components, and improving the working reliability of the hydraulic system and components.

1.The basic requirements for hydraulic oil in the hydraulic system in the hydraulic machine: hydraulic oil stone is the working medium for transmitting and converting energy in hydraulic transmission, and at the same time plays the role of lubricant. The performance of hydraulic oil is directly related to the working performance of the hydraulic system.

 

2.Types and properties of hydraulic oil: At present, hydraulic oil for hydraulic machines in my country is classified as follows according to its composition and properties:

 

Commonly used hydraulic oils in hydraulic systems:

 

Petroleum type: ordinary hydraulic oil, hydraulic guide oil, anti-wear hydraulic oil, low temperature hydraulic oil, high viscosity index hydraulic oil, machine oil (substitute), turbine oil (substitute), other special hydraulic oil;

 

Emulsified type: oil-in-water emulsion, water-in-oil emulsion;

 

Synthetic type: water-glycol liquid, phosphate ester liquid, others.

 

Among the above classifications, petroleum-based hydraulic oil is the most widely used working medium in hydraulic transmission systems, and the property indicators of different types of hydraulic oil are also different.

 

From the perspective of the requirements for using hydraulic oil in hydraulic systems, the following points can be summarized:

 

1. It has good compatibility with various materials used in hydraulic systems, including metal, plastic, paint, rubber, etc.

 

2. It has good thermal stability, oxidation stability and hydrolysis stability.

 

3. Suitable year and good viscosity-temperature performance. Too much plating of hydraulic oil will increase the mechanical wear power of the system, and too small a viscosity of the hydraulic oil in the hydraulic machine will increase the volume loss power of the system. Therefore, the hydraulic oil plating should be selected appropriately to minimize the sum of mechanical and volume losses of the system. The so-called good viscosity-temperature performance means that the viscosity change of the oil should be as small as possible within the range of operating temperature changes. To sum up, the viscosity of hydraulic oil used in general hydraulic systems is mostly between (0.115cm2/s) and (0.6cm2/s). The viscosity index value of hydraulic oil is required to be above 90, and the excellent one is above 100.

 

4. It has good fluidity, and the flow point and freezing point of the oil should be low. Generally, the flow point of mineral oil-based hydraulic oil is between -5°C and -15°C, and the low-condensing oil can reach -45°C.

 

5. It has good flame resistance, and the flash point and ignition point of the oil should be high. Generally, the flash point of mineral oil-based hydraulic oil is between 150°C and 220°C.

 

6. It has good lubricity and high oil film strength, reducing the wear of the friction surfaces of the hydraulic system.

 

7. Has good anti-rust effect.

 

8. The air solubility is small, the foaming property is small and defoaming is easy. It has low water absorption and is easy to separate from water.

 

9. The bulk modulus should be large.

 

10. It is non-toxic to the human body and has obvious stimulating effect.

 

  Dongguan Shengshi Weiye Machinery Technology Co., Ltd. specializes in the production of Forging Press, Deep Drawing Hydraulic Press, Gravity Casting Machine, Four-column Servo Press, C Type Pneumatic Press and other machines. Friends in need are welcome to pay attention and learn more.