How to choose the correct use of hydraulic oil for different hydraulic systems?

(1) Pollution wear of components

Various pollutants in the oil cause various forms of wear of the components, and solid particles enter the clearance of the moving pair, resulting in cutting wear or fatigue wear on the surface of the parts. The impact of solid particles on the surface of components in high speed liquid flow causes erosion wear. The water in the oil and the products of the oil oxidation and deterioration have a corrosive effect on the components. In addition, the air in the oil of the system causes cavitation, resulting in erosion and destruction of the component surface.

(2) Component plugging and clamping failure

Solid particles block the gap and orifice of the hydraulic valve, causing the valve core to block and clamp, affecting the working performance, and even leading to serious accidents.

(3) Accelerate the deterioration of oil performance

The heat energy of the water and air in the oil is the main condition for the oxidation of the oil, and the metal particles in the oil play an important catalytic role in the oxidation of the oil, in addition, the water and suspended bubbles in the oil significantly reduce the strength of the oil film between the moving pairs, so that the lubrication performance is reduced. To this end, the following should be done:

(1) According to the instructions, choose the appropriate hydraulic oil. ① The type and precision requirements of hydraulic oil must be based on the specific provisions and requirements of the hydraulic system and component manufacturers; ② If substitute oil is used for some reason, the performance requirements of the original oil should be met as far as possible; Do not mix different grades of hydraulic oil.

(2) A closed oil tank is used, and an air filter with certain precision is installed at the population of the oil tank.

(3) During use, moisture and emulsion should be prevented. Dust. Infringer of fiber debris and other mechanical debris.

(4) The amount of hydraulic oil should be appropriate. The oil amount of the hydraulic tank should be kept within the specified oil level range after the system pipeline and components are filled with oil.

(5) Components, pipelines and systems must be strictly cleaned before being put into use.

(6) Must be strictly filtered when refueling. Check the oil filter frequently and replace it when dirty.

(7) Check the quality of hydraulic oil regularly to keep the hydraulic oil clean. When checking the quality of hydraulic oil, the following three aspects are mainly checked: ① The oxidation degree of hydraulic oil in use, due to changes in temperature, oxygen in the air and the action of sunlight, it will gradually be oxidized, so that its viscosity and other properties change. The degree of oxidation is usually judged from the color and smell of the hydraulic oil. If the hydraulic oil is dark brown in color and has a foul smell, it has been oxidized. The darker the brown, the stronger the odor, the more oxidized it is. At this time, new oil should be replaced. ② The degree of water in hydraulic oil if the hydraulic oil is mixed with water, it will reduce its lubrication performance and corrode metal. There are usually two ways to determine the degree of water mixed in hydraulic oil, one is according to the change of color and smell, such as the color of hydraulic oil is milky, the smell has not changed, it means that the water is too much. The second is to take a small amount of hydraulic oil drops on the hot iron plate, if the sound of "horn" is issued, it indicates that it contains water. At this time, new oil should be replaced. After mechanical work for a period of time, take a few drops of hydraulic oil on the hand, twist it with your fingers, and see if there are metal particles, or observe whether there are tiny flashes in the sun. If there are more metal particles or flash points, it is proved that the hydraulic oil contains more mechanical impurities. At this time, the hydraulic oil should be replaced, or the hydraulic oil should be released, and the precipitation of not less than 42h is carried out, and then the filter is used.

(8) When replacing hydraulic oil, pay attention to the fact that the machine has just finished working, and the hydraulic oil is released when it is hot (so that it is easy to bring out mechanical impurities, oil, etc.). The specific method is to manipulate the working device so that it is placed in the highest position, turn off the engine, use its own weight to drop, so that the cylinder is completely discharged, and then thoroughly clean the fuel tank and the corresponding pipeline, and add new hydraulic oil.

(9) Correct cleaning of the hydraulic system. It is best to use the same hydraulic oil used in the system. Do not use kerosene or diesel as cleaning fluid. The maximum flow rate should be used when cleaning, so that the liquid flow in the pipeline is turbulent, and the action of each executive element is completed in order to flush out the pollutants from the various pumps, alarms and hydraulic cylinders. After cleaning, drain the cleaning liquid in the hot state, and add new working oil according to the method of replacing oil.

Large table hydraulic press