(1) Prevent oil contamination
The suction port of the hydraulic pump should be equipped with a strainer, and the suction port should be at a certain distance from the bottom of the tank; the high pressure fine filter should be installed at the oil outlet, and the filtering effect should meet the working requirements of the system to prevent the dirt from clogging and causing the hydraulic system. Failure; a filter should be installed on the hydraulic tank baffle to remove impurities that are not filtered out of the return filter. A metal protective ring should be installed on the hydraulic cylinder to prevent dirt from being carried into the cylinder and prevent muddy water and light radiation from colliding with the hydraulic cylinder. The hydraulic components should be inspected and cleaned before installation. Regularly check the hydraulic oil. Once the oil is found to be deteriorated, the foam is high, the sediment is large, and the oil and water are separated, the system should be cleaned immediately and the oil changed. Before the new oil is added to the fuel tank, it should be settled by static precipitation. After filtration, it can be added. If necessary, an intermediate oil tank can be set up to precipitate and filter the new oil to ensure the oil is clean.
(2) The roughness of the sealing surface should be appropriate
If the roughness of the hydraulic system relative motion surface is too high or axial scratches will occur, the roughness will be too low. When the mirror surface is reached, the lip of the sealing ring will scrape off the oil film, making the oil film difficult to form and the sealing edge is generated. High temperature, which aggravates wear and tear, 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 a low roughness. The surface roughness of the dynamic sealing parts such as hydraulic cylinders and slide valves should be between Ra0.2 and 0.4 дm to ensure that the oil film on the sliding surface during movement is not destroyed. When an axial scratch occurs on the rods of the hydraulic cylinder and the slide valve, the lighter can be polished with metallographic sandpaper, and the heavy one should be plated and repaired.
(3) Reasonable design and processing of sealed trenches
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 groove size of the static seal between the piston and the piston rod is small, there is no slight room for movement in the groove, and the bottom of the seal will be damaged by the reaction force, resulting in oil leakage. The design of the sealing groove (mainly the structural shape, size, geometrical tolerance of the groove and the roughness of the sealing surface) shall be strictly in accordance with the standard requirements.
To prevent the oil from leaking outward from the static seal, the size and tolerance of the seal groove of the static seal must be reasonably designed, so that the static seal after installation can be squeezed and deformed to fill the micro-pits of the mating surface, and the seal can be sealed. The internal stress is raised above the pressure being sealed. When the part stiffness or bolt pre-tightening force is not large enough, the mating surface will be separated under the action of oil pressure, causing the gap to be too large. As the mating surface moves, the static seal becomes a dynamic seal.