today Huai'an Crane Rental Company Explain the reason why the crane hydraulic cylinder is unstable!

1. The crane hydraulic pump or oil cylinder enters air.

Air compression or expansion will cause the piston to slide or crawl. The elimination measures are to check the hydraulic pump, set a special exhaust device, and quickly operate the full stroke several times.

2. The hydraulic cylinder has convergence.

crane Improper assembly of parts in the hydraulic cylinder, deformation, wear of parts or excessive form and position tolerance, and excessive action resistance make the piston speed of the hydraulic cylinder change with different travel positions, resulting in sliding or crawling. The reason is that the poor assembly quality of parts, surface damage or iron chips generated by sintering increase the resistance and speed. For example, the piston is not concentric with the piston rod or the piston rod is bent, the hydraulic cylinder or piston rod deviates from the installation position of the guide rail, and the seal ring is too tight or loose. The solution is to repair or adjust, replace damaged parts and clean up iron chips.

3. The hydraulic cylinder has poor lubrication or poor hole processing.

Huai'an Crane Rental Remind that due to the relative motion of the piston and cylinder barrel, guide rail and piston rod, if the lubrication is poor or the hydraulic cylinder bore diameter is poor, the wear will be aggravated and the straightness of the cylinder centerline will be reduced. In this way, when the piston works in the hydraulic cylinder, the friction resistance will be greatly reduced, resulting in sliding or crawling. The elimination method is to first repair and grind the hydraulic cylinder, then prepare the piston according to the matching requirements, and then grind the piston rod and configure the guide sleeve.

4、 crane The quality of seals is directly related to sliding or crawling.

When the O-ring is used under low pressure, compared with the U-ring, the surface pressure of the O-ring is high, the dynamic and static friction resistance difference is large, and the O-ring is easy to slip or crawl; The surface pressure of U-ring increases with the increase of pressure. Although the sealing effect also increases correspondingly, the difference between dynamic friction resistance and static friction resistance will also increase. The internal pressure increases, which affects the elasticity of the rubber. As the contact resistance of the lip increases, the seal ring will roll and the lip edge will extend, which is easy to cause sliding or crawling. To avoid overturning, it can be stabilized by supporting environmental protection.