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Cause Of Oil Leakage In Hydraulic Cylinder

Pressure under 16MPA hydraulic cylinder is called the low-pressure hydraulic cylinder, it is widely used in bulldozers, loaders, graders and cranes and other construction machinery. This kind of hydraulic cylinder seals the domestic and foreign often uses the oil-resistant rubber as the material, such as the nitrile rubber, the cloth and the EPDM rubber and so on.

The sealing part of the hydraulic cylinder is two parts: the outer seal includes a static seal between the cylinder and the cylinder head and a moving seal between the cylinder head and the piston rod.Hydraulic Cylinder 

The function of the two is to ensure that the hydraulic cylinder does not produce external leakage, and the inner seal includes a dynamic seal between the piston and the inner diameter of the cylinder and a static sealing part of the piston and the piston rod connection. The performance status of these seals is the key to determine whether the hydraulic cylinder can achieve the design capability.Hydraulic Cylinder 

In order to ensure the static sealing performance between cylinder and cylinder head, in addition to choosing reasonable static fit clearance and suitable o-ring, it is best to assemble nylon backing on the extrusion side of O-ring, which can improve the bearing capacity of the sealing ring, increase the pretension of flange bolts or head screws, and prevent the loosening of vibration in the work. Causes the static seal face to the dislocation to wear, causes the seal piece to be damaged.Hydraulic Cylinder

The gap between piston rod and cylinder head guide sleeve is not up to the original design requirement. Because of the long-term use, the leading part of the grinding loss circle, tension, gap increase or gap oil film seal damage, etc. is the main factor that causes the piston rod oil leakage. In this state, even if the replacement of new seals, will still produce hydraulic oil from the piston rod outside the leakage of symptoms.Hydraulic Cylinder

All seals of the Assembly shall conform to the standard material. Y-shaped, V-shaped, U-shaped, yx-shaped seals such as the appearance of quality may not have concave and convex, impurities, bubbles, scratches and burr flying edge and other defects, dust-proof coil loaded into the piston rod should not be bitten, or should replace the new pieces. Use gasoline or cleaning oil before assembly (strictly prohibit diesel or kerosene) to clean all fittings, the residue of the inner and outer ring groove of the cylinder head is wiped clean with a thick cloth or a cotton cloth, which can be loaded into the seal, and the hydraulic oil should be coated on the contact surface of the sealing part and the guide sleeve (no dry assembly).Hydraulic Cylinder 

When the cylinder head is loaded into the piston rod, it is best to assemble it from the horizontal or vertical direction, and when the two concentric is ensured, the hardwood stick is gently penetrated. The condition can also be processed a guide cone sleeve, and then with the nut to enter or with a hardwood into, so as not only protect the oil seal surface, but also ensure that the cylinder head can be smoothly loaded into the cylinder.Hydraulic Cylinder