The following is a simple analysis of hydraulic cylinders, such as the reasons for poor airtightness and leakage found:
For example, the seals in the cylinder are old, or not properly installed. Or the oil of the hydraulic cylinder is not up to standard: the oil of the hydraulic cylinder is not regularly inspected according to the requirements, and the oil exceeds the standard, resulting in wear and tear of the rubber seals; or due to the moisture in the oil, so that the servo valve group is corroded and damaged, thus causing leakage.
Combined surface sealing is not tight: the general use of gaskets or applying flat sealant method to seal, if the sealant is not completely dry, it will lead to sealing surface breakage, resulting in leakage. Supply and return pipe joints are not sealed tightly: the reasons for this situation are: loose pipe joints, loose sealing gaskets, pipeline sand holes, oil seepage from the switching valve of the petrol station filter, internal leakage of the valve and so on. In these cases, it is necessary to disassemble the petrol station filter switching valve oil seepage and valve internal leakage to determine the specific location.
Excessive oil flow in the bearing box: Under normal circumstances, when the oil supply flow is too large, due to the high rotor speed and the rise in lubricant temperature, it will inevitably cause the oil level in the bearing box to exceed the specified upper limit, thus causing shaft seal leakage. In addition, too much oil pressure may also cause shaft seal leakage.
The most leaking part of the bearing box is the shaft seal. The oil leakage is caused by the long-term wear and aging of the O-ring and frame oil seal, as well as unreasonable installation during maintenance. In the process of use, the leakage of the shaft seal is difficult to control and difficult to be detected. Its most obvious feature is the slow lowering of the oil level in the oil station. Occasionally, there will be oil from the leakage in the fan casing, expansion joints, baffles and other places where the sealing is not tight, and during the shutdown inspection, it can also be seen that there is a large amount of accumulated oil on the inner wall of the outlet of the air box behind the casing and on the blades.
