Hydraulic cylinder manufacturer Hydraulic system Leakage form and treatment method

The leakage of hydraulic system can be divided into internal leakage and external leakage according to the flow direction. External leakage mainly refers to the leakage of hydraulic oil from the system to the environment, which is generated in the hydraulic pipeline, hydraulic valve Hydraulic cylinder And hydraulic pump（ Hydraulic motor ）External; Internal leakage refers to the leakage of hydraulic oil from the high pressure side to the low pressure side in the system due to the existence of the pressure difference between the high pressure side and the low pressure side and the failure of seals, such as the leakage of oil from the high pressure chamber to the low pressure chamber in hydraulic transmission; Leakage from the pressure channel in the reversing valve to the oil return channel, etc. The main forms of leakage include crevice leakage, multi pore leakage, adhesive leakage and dynamic leakage.

1. Gap leakage

There are mainly two kinds of crevice leakage in the hydraulic system of construction machinery, the leakage at the fixed seal (static joint surface) and the leakage at the moving seal (dynamic joint surface). The leakage part of the fixed seal mainly includes the joint between the head of the hydraulic cylinder and the cylinder barrel; The moving seal mainly includes the position between the hydraulic cylinder piston and the inner wall of the cylinder barrel, and between the piston rod and the cylinder head guide sleeve. The amount of gap leakage is related to pressure difference, gap and other factors.

2. Porous leakage

Due to the influence of surface roughness, the two surfaces of various cover plates in hydraulic components cannot be completely contacted. At the micro depression where the two surfaces do not contact, many gaps with various cross section shapes and sizes are formed. The cross section size of the gap is related to the surface roughness. For multi void leakage, the liquid needs to flow through many curved voids. When conducting the sealing performance test, the leakage can only be exposed after a certain pressure holding time.