There are many reasons for the failure of the hydraulic system of an excavator, generally including hydraulic oil pollution, air influence, hydraulic oil leakage, etc. This article analyzes the causes of the first two types of failures and their countermeasures in detail:

Hydraulic oil contamination

Contamination of hydraulic oil will block and damage hydraulic components, cause malfunctions, may cause filter blockage, affect work performance, cause accidents, make the filter useless, cause a vicious cycle of hydraulic system, accelerate hydraulic component wear, and increase leakage , It seriously affects the stability and reliability of the system, and also accelerates the deterioration of hydraulic oil. The long-term existence of pollutants will corrode hydraulic components. The following points should be taken to prevent hydraulic oil pollution:

1: Try to prevent water from entering the hydraulic oil. Check and replace the hydraulic oil regularly. Sample the hydraulic oil of the excavator at regular intervals. If it does not meet the requirements, replace it in time. When changing the hydraulic oil, all hydraulic components must be thoroughly cleaned.

2: In a very harsh working environment, use a dust ring and protective cover to protect the piston rod to prevent dust and abrasives from entering the working medium.

3: During refueling, oil level inspection and maintenance operations, impurities enter the hydraulic oil and enter the hydraulic system through the worn oil seals and seal rings. The parts removed for maintenance should be kept clean to prevent contamination.

 Air influence

Under atmospheric pressure, the hydraulic oil contains about 6% ~ 12% air. When the pressure of the hydraulic oil is lower than the atmospheric pressure, the air dissolved in the hydraulic oil will be quickly separated from the water, resulting in a large number of bubbles. The air bubbles flow with the hydraulic oil to the higher pressure parts, and the air bubbles burst due to high pressure, which causes cavitation, accelerates the oxidation and corrosion damage of the components, causes the formation of pits on the surface of the hydraulic system components, and accelerates the wear of the hydraulic system components. How to solve these problems, we should pay attention to the following points

1: Try to avoid the air in the hydraulic oil from turning into gas, try to use a larger diameter hydraulic oil pipe to reduce local resistance and avoid local high pressure.

2: The joint is loose and the sealing ring is damaged. The hydraulic system should have good sealing, and the joints should be tight and firm.

3: The bubbles generated when refueling are brought into the oil tank and merged into the hydraulic oil. Special components should be installed in the fuel tank to reduce the generation of bubbles in the hydraulic system, and a bubble separation net should be installed, which can separate about 90% of the bubbles.