Common dynamic seal device for hydraulic system of the cause of the problem and countermeasure

Common dynamic seal device for hydraulic system of the cause of the problem and countermeasure - 2020 06 - And a reciprocating motion seal the causes and countermeasures of common failures here two typical sealing system - a combination of slip-ring seal and Y seal in the application of the hydraulic cylinder reciprocating motion. The advantages of the combination of slip-ring seal is mainly the piston structure is compact, and due to the slip ring lubricating material itself, low friction coefficient, hydraulic cylinder for reciprocating motion when very small friction resistance, and can avoid the hydraulic cylinder 'crawl' and abnormal noise. Y seal is the most widely used a lip seals, sealing device is a kind of more economic. The main advantages are low cost and reliable sealing performance. But the structure of the piston size slightly bigger than the former, the piston seal in the work exists in left and right two lip packing produce between back pressure and seal condition is not stable, and seal back up and move, will happen to seal lip margin or chew the phenomenon such as cutting the root. To prevent this phenomenon, can adopt the following measures: 1. Control the slip plane with precision ( Hg/fg) ； Control of the gap between the piston and cylinder inner diameter; The integral piston. 2. Control the gap at the same time, gas channel mouth; The integral piston. 3. Along the piston ends facing the lip seal grooves parts processing and uniform conducting oil hole, at the same time control the clearance. 4. In the lip seal grooves and pure rubber bearing ring. Made of nitrile rubber and polyurethane rubber Y ring in use in the light of the cause of the problem and elimination method are shown in table 1 and table 2 respectively. Table 1 NBR Y circle of common fault causes and countermeasures of table 2 Y polyurethane rubber ring common fault causes and countermeasures, rotating sealing device common fault causes and countermeasures rotating sealing device is composed of skeleton oil seal and its hole ( Oil seal installation cavity) And the corresponding dynamic sealing pair of couple ( Axis) . Its general performance for the oil seal type of outside diameter and hole leakage between the mating surface, and the oil seal lip margin between the rotor and the leakage, and some of the reasons for these two kinds of leakage. Along the outer diameter of oil seal and a hole between the mating surface has oil seal leakage causes of hole size is too big, rough surface oil seal hole or holes, oil seal caused by improper assembly device malposition and loss of oil seal diameter circle, etc. ; Along the seal between the sealing lip margin and the axial surface leakage reasons of oil seal lip margin excessive wear or eccentric wear, lip rims have Nick, damage and deformation defects, due to improper assembly lip cock, spring, fall off and labial margin flip, rubber metamorphism cause swelling and hardening, eccentric shaft, rough and defects, etc. Specific reasons and the countermeasures are shown in table 3. Table 3 rotating sealing device with skeleton oil seal common fault causes and countermeasures