1. may be200 ton hydraulic pressAir is mixed in the hydraulic system;
2. Due to poor lubrication, the guide rail is not parallel to the axis of the hydraulic cylinder, the sealing pressure of the piston rod is too tight, and the piston rod is bent and deformed, etc., the friction force changes greatly during the working stroke of the hydraulic cylinder and causes crawling.
3. In the oil inlet throttling speed control system, the hydraulic cylinder has no back pressure or insufficient back pressure, and when the external load changes, the cylinder speed changes
4. The flow pulsation of the hydraulic pump is large, and the vibration of the overflow valve causes the pressure pulsation of the system, which is caused by the fluctuation of the input pressure oil of the hydraulic cylinder.
5. The valve port of the throttle valve is blocked, the system leakage is unstable, and the pressure reducing valve in the speed control valve is not flexible, which causes the flow to be unstable and causes crawling