Hydraulic press crawling is very harmful. It can damage the working surface quality (roughness) and machining accuracy of hydraulic equipment, reduce the service life of hydraulic machine tools and tools, and even produce waste products and accidents. Therefore, it must be eliminated.

The actuating element (hydraulic cylinder or hydraulic motor) of hydraulic press equipment often needs very low speed, such as moving several millimeters or less than 1mm per minute or rotating several revolutions per minute. At this time, there will be obvious uneven speed, intermittent movement and stop, one fast and one slow, one jump and one stop. This phenomenon of hydraulic press becomes creeping, that is, the problem of low speed stability. The minimum speed without creeping phenomenon is called the critical speed of motion stability.

The same is crawling, and its fault phenomenon is different: regular crawling, regular crawling; Some creep irregularly and with large amplitude; Some crawls occur at very low speeds. The reasons for these different crawling phenomena are different: some are mainly mechanical, some are hydraulic, some are air in oil, and some are poor lubrication. For the maintenance and operation of hydraulic equipment of hydraulic press, the maintenance personnel must constantly summarize and summarize, quickly find out the causes of crawling and eliminate them. To solve the problem of hydraulic press crawling, the following aspects should be taken into consideration. Focus on solving the friction state of moving parts and the balance of machine motion:

1) The precision of the guide rail is poor, and the guide rail surface (V-shaped, flat guide rail) is seriously distorted.

2) There are rust spots on the guide rail surface.

3) The pressing plate insert of the guide rail is adjusted too tightly, and the dynamic and static friction coefficients of the guide rail pair materials vary greatly.

4) The guide rail is poorly scraped, the points are not enough, and the points are uneven.

5) The oil groove on the guide rail is not good, the depth is too shallow, it has been worn off during operation, the oil groove is uneven, and the length of the oil groove is too short.

6) The guide rail of the hydraulic equipment of the new hydraulic press has not been run in.

7) The axis line of the hydraulic cylinder on the hydraulic press is not parallel to the guide rail.

8) The arresting section in the cylinder block hole of the hydraulic cylinder on the hydraulic press is rusted (local section crawls) and strained.

9) The hydraulic cylinder hole, piston rod and piston on the hydraulic press have poor accuracy

10) The hydraulic cylinder and installation accuracy on the hydraulic press are poor, and the concentricity of the piston, piston rod, cylinder hole and cylinder cover hole is poor.

11) The hydraulic cylinder piston or cylinder head seal is too tight, blocked or loose.

12) The shutdown time is too long, and the water in the oil (especially the grinder coolant) causes some parts to rust.

13) The hydrostatic guide rail restrictor is blocked, and the guide rail is out of oil.