What are main the reasons for the damages of hydraulic cylinders?

The engineering hydraulic cylinder is composed of two parts: the main engine and the control arrangement. The main part of the hydraulic press includes the fuselage, the main cylinder, the ejector cylinder and the liquid filling device. The power system consists of a fuel tank, a high-pressure pump, a low-pressure control system, an electric motor, and different pressure valves and directional valves. The general method of the hydraulic cylinder of the power hydraulic press is a thick-walled high-pressure vessel with one end open and one end closed. The structure of the hydraulic cylinder of the hydraulic press can generally be divided into three parts, namely the cylinder bottom, the flange and the middle thick-walled cylinder. The working cylinders of hydraulic presses are heavily loaded and frequently operated, and are often prematurely damaged due to improper planning, manufacturing or use.

Most of the damaged parts of the cylinder are in the arc part connecting the flange and the hydraulic cylinder barrel, and secondly in the arc part where the cylinder wall transitions to the bottom of the cylinder. A small amount of cracks are formed on the cylinder wall, and some are damaged due to severe cavitation. From the point of view of use, it has generally endured a high number of operating loads when it is damaged, and cracks are gradually formed and expanded, which are fatigue damage. There are many factors affecting the service life of engineering hydraulic cylinders, which should be analyzed in combination with specific conditions, but in general, there are the following aspects:

1. The wall of the hydraulic cylinder tube. Generally, cracks appear on the inner wall of the hydraulic cylinder tube and gradually develop outward. The lines develop outward, and the cracks are mostly distributed longitudinally, or at an angle of 40 degrees to the busbar of the hydraulic cylinder tube wall.

2. The flange part of the hydraulic cylinder. First, the lines appear on the surface of the cylinder flange at the transition arc, and gradually expand to the circumferential direction and the inner wall, or the crack may extend to the nail hole, causing the flange to fall. The ring cracked and fell off.

3. Bottom of the hydraulic cylinder. Circumferential cracks first appeared at the beginning of the inner surface of the transition arc at the bottom of the hydraulic cylinder, and gradually expanded to the outer wall and even cracked.

4. Cavitation. The engineering hydraulic cylinder is also damaged by honeycomb pitting caused by cavitation, and cavitation is easily generated on the inner wall of the entry hole.

5. Reasons for planning. The structural dimension planning is unreasonable, such as the flange height is too small or the flange outer diameter is too large, so that the structure should be too high and damaged.