(1) hydraulic top internal astringency. Hydraulic top internal parts installation is not reasonable, parts deformation, damage or size tolerance exceeds the limit, posture friction resistance is too large, so that the hydraulic top piston speed changes with the difference of the stroke arrangement, slippage or crawling. Most of the reason is because of the poor quality of parts installation, surface scar or calcination caused by the iron pin, so that the friction resistance expanded, the rate is reduced. For example: the piston and the piston rod is not the same as the heart or the piston rod bending, hydraulic thousand jin top or piston rod on the slide rail installation partial, hydraulic seals installed too tight or too loose. Pneumatic jack company solution is to repair or adjust again, remove damaged parts and eliminate iron pins.

(2) poor wetting or hydraulic top diameter production and processing deviation. Because the piston and cylinder liner, slide rail and piston rod, etc. have relative speed, if the wetting is not good or the diameter deviation of hydraulic thousand pounds top, it will increase the damage, so that the cylinder liner axis parallel linear reduction. In that way, the customized piston of the hydraulic jack works in the top of the hydraulic pressure, when the friction resistance will be too large or small, resulting in slippage or crawling. The cleaning method is to grind the hydraulic top first, and then equip the piston, the grinding piston rod and the guiding sleeve according to the provisions of mutual cooperation.

(3) hydraulic pump or hydraulic jack into the gas. Compressed air or swelling can cause the piston to slip or crawl. Cleaning countermeasures are to check the hydraulic oil pump, set up a professional gas-water separator, and quickly operate the exhaust pipe with full travel arrangement.

(4) The quality of hydraulic seals is immediately related to sliding or crawling. O type seal ring in low voltage application, and U type seal ring is more, because the surface pressure is higher, the difference of sound friction is relatively large, very easy to cause sliding or crawling; U-shaped seal surface pressure of the working pressure of ascension and expansion, while sealing effect also corresponds to ascend, but sound friction will increase, the difference between the gas pressure increase, plastic deformation, pressure touch because of labial margin expansion, sealing ring can overturn and labial margin stretch, it is easy to slip or crawl, Pneumatic jack manufacturers can choose support ring to maintain its stability in order to avoid overturning.

Detailed analysis of hydraulic jack fault detection