Hydraulic cylinder piston sliding or crawling will make the hydraulic cylinder work instability. Do you know the reason for it? Do you know what to do with it? The following article is mainly for you to talk about.
(1) hydraulic cylinder internal astringency. Improper assembly of the internal parts of the hydraulic cylinder, deformation, wear or tolerance of shape and position exceeds the limit, too much action resistance, so that the speed of the hydraulic cylinder piston changes with the different stroke position, and there is sliding or crawling. Most of the reasons are due to the poor assembly quality of parts, surface scars or sintered iron filings, so that the resistance increased, speed down. For example: piston and piston rod different heart or piston rod bending, hydraulic cylinder or piston rod on the guide rail installation position deviation, sealing ring installed too tight or too loose. The solution is to repair or adjust, replace the damaged parts and remove the iron filings.
(2) poor lubrication or hydraulic cylinder aperture processing out of tolerance. Because the piston and cylinder, guide rail and piston rod have relative movement, if the lubrication is poor or the hydraulic cylinder aperture is out of tolerance, it will aggravate wear, so that the cylinder centerline linearity is reduced. In this way, when the piston works in the hydraulic cylinder, the friction resistance will be large and small, resulting in sliding or crawling. The solution is to repair the grinding hydraulic cylinder, and then according to the requirements of the piston, repair the piston rod, the configuration guide sleeve.

(3) Hydraulic pump or hydraulic cylinder forgings into the air. Air compression or expansion causes the piston to slip or creep. The elimination measure is to check the hydraulic pump, set up a special exhaust device, fast operation of the full stroke and return several exhaust.
(4) the quality of seals is directly related to slip or creep. When o-ring is used at low pressure, compared with U-ring, it is easy to slip or creep because of the higher surface pressure and the difference of static and static friction resistance. U-shaped seal surface increases with the increase of pressure as the pressure, although sealing effect also increase, but the dynamic and static friction resistance is larger, the difference between the internal pressure increases, the influence of rubber elasticity, the contact resistance is increased due to the lip margin, sealing ring will be tilting and lip edge elongation, also easy to cause slipping or crawl, can be used to prevent the tilting bearing ring keep its stability.
Above is the main content of this article, I hope to be able to help you.