Preventive Measures Of Hydraulic System Leakage (1)

1. Prevent oil contamination

The oil suction port of the hydraulic pump should be installed with a coarse filter, and the oil suction port should be a certain distance from the bottom of the fuel tank; the oil outlet should be installed with a high-pressure fine filter, and the filtering effect should meet the working requirements of the system to prevent the hydraulic system from being blocked by dirt. Failure; a filter screen should be installed on the separator of the hydraulic oil tank to remove impurities not filtered by the oil return filter. A metal protective ring should be installed on the hydraulic cylinder to prevent dirt from being brought into the cylinder, and to prevent leakage caused by the erosion of the hydraulic cylinder by muddy water and light radiation; the internal iron filings and impurities should be checked and cleaned before the hydraulic components are installed. ; Regularly check the hydraulic oil. Once the oil is deteriorated, there is much foam, there is a lot of sediment, and the oil and water are separated, the system should be cleaned and the oil should be changed immediately. Before adding the new oil to the oil tank, it should be allowed to stand for precipitation, and then it can be added after filtering. If necessary, an intermediate oil tank can be set up for the precipitation and filtering of the new oil to ensure the cleanliness of the oil.

2. The roughness of the sealing surface should be appropriate

If the roughness of the surface of the hydraulic system relative to the moving pair is too high or there is an axial scratch, leakage will occur; if the roughness is too low, the lip of the sealing ring will scrape off the oil film when it reaches the mirror surface, making it difficult to form the oil film, and the sealing edge will be generated. High temperature will increase wear, so the roughness of the sealing surface should not be too high or too low. The sliding surface in contact with the sealing ring must have low roughness. The surface roughness of dynamic seals such as hydraulic cylinders and slide valves should be between Ra0.2～0.4дm to ensure that the oil film on the sliding surface does not move during movement. destroyed. When there are axial scratches on the rods of the hydraulic cylinder and slide valve, the light ones can be polished with metallographic sandpaper, and the heavy ones should be repaired by electroplating.

3. Reasonable design and processing of sealing grooves

The design or processing of the hydraulic cylinder seal groove is a prerequisite for reducing leakage and preventing premature failure of the oil seal. If the size of the groove of the static seal between the piston and the piston rod is too small, the sealing ring has no small room for movement in the groove, and the bottom of the sealing ring will be damaged by the reaction force, resulting in oil leakage. The design of the sealing groove (mainly the structural shape, size, shape and position tolerance of the groove and the roughness of the sealing surface, etc.) should be carried out in strict accordance with the standard requirements.

To prevent the oil from leaking out from the static seal, the size and tolerance of the sealing groove of the static seal must be reasonably designed, so that the installed static seal can fill the microscopic pits on the mating surface after being squeezed and deformed, and can seal the seal. The internal stress is raised above the pressure being sealed. When the rigidity of the parts or the pre-tightening force of the bolts is not large enough, the mating surfaces will be separated under the action of oil pressure, resulting in excessive clearance. With the movement of the mating surfaces, the static seal becomes a dynamic seal.