Hydraulic Cylinder Leak of the Excavator

I believe that everyone must have encountered the oil leakage of the hydraulic cylinder. For the excavator, once the hydraulic cylinder leaks, there will be a phenomenon of slow lifting and insufficient digging force.

Under normal circumstances, the leakage of hydraulic cylinders is divided into internal leakage and external leakage. As long as we look closely, we can judge the cause of external leakage. It is difficult to judge the internal leakage of the hydraulic cylinder because the internal leakage is not directly observable.

1. Internal leakage

The oil leakage is caused by deformation, ageing, wear and tear of the main oil seal.

Generally, in the long-term high-temperature and high-pressure, high-speed movement, the main oil seal is easy to age. Even the best oil seal has the possibility of deformation in this case, and the probability of good oil seal modification is small. After the Y-type oil seal is changed, there is no tension in the sealing lip, resulting in oil leakage.

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When working, a large amount of dust and impurities will adhere to the cylinder rod. The dustproof oil seal can prevent dust and impurities from entering the cylinder and prevent damage to the cylinder and the oil seal. In the case of damage to the dust seal, the dust will directly enter the cylinder head and direct damage. The oil seal and the oil cylinder will wear out in the case of a large amount of dust, and the inner lip is obviously worn.

The cylinder is black and the inner wall is strained. The lead of the additive in the inner wall of the spray adheres to the surface of the cylinder under long-term high-temperature friction, which means that the wear ring needs to be replaced. The wear ring (cup) is very important in the cylinder, one is for wear resistance, and the other is to eliminate the impact of lateral force. If it is not replaced after wear, the cylinder will be black, the main oil seal will seep (because the main oil seal cannot be effectively eliminated due to the impact of the lateral force), and the cylinder is pulled.

2. External leakage

Reasons can be: Cracking of the cylinder inlet and outlet tubing joints can also cause leakage of the hydraulic cylinder. Oil leakage is caused by defects on the cylinder block or cylinder end cover. The deterioration of the lubricating oil causes the temperature of the cylinder to rise abnormally, which causes the sealing ring to age. The piston rod is pulled up to the groove, there are pits and so on. The seal of the piston rod protruding end and the piston rod is damaged, mostly due to the pulling of the piston cylinder, and also caused by ageing. The piston rod protruding end and the cylinder sleeve sealing seal damage is mostly due to the seal ageing caused by long-term use.

3. Precautions for the use of hydraulic cylinders

In normal use, we should pay attention to protecting the outer surface of the piston rod to prevent the damage of the seals caused by bumps and scratches. Now some construction machinery cylinders are designed with protective plates. Although there are, we still have to pay attention to prevent bumps and Scratches.

We should also pay attention to checking the joints of various threads and bolts frequently, and find that the looseness is immediately tightened.

Remember full-scale tests should be running 3-5 strokes before use. The purpose of this is to exhaust the air in the system and preheat the systems, so as to effectively avoid the presence of air or water in the system, causing a gas explosion in the cylinder block, which will damage the seals, cause cylinder leakage, etc. malfunction.

Normal maintenance: we should pay attention to the regular replacement of hydraulic oil, timely cleaning of the system filter to ensure the cleanliness of the hydraulic oil, which is also very important for extending the life of the hydraulic cylinder.

After each work is completed, we need to pay attention to the size of the arm and the bucket to maintain an optimal state, that is, to ensure that the hydraulic oil in the hydraulic cylinder is all returned to the hydraulic tank, to ensure that the hydraulic cylinder is not under pressure. Because the hydraulic cylinder is subjected to pressure in one direction for a long time, it also causes damage to the seal.

The oil leakage of the hydraulic cylinder can be avoided by using high-quality seal kits from YBAS.