The real cause of piston damage of crushing hammer

My friends who often use hammers may have encountered piston fracture, but they don't know why. Of course, they are responsible for the quality. Maybe everyone agrees that it is caused by fatigue. Although fatigue is also a major cause, there are also weather problems. Human factors are involved in it, which has a lot to do with the operation.

To prolong the service life, in addition to the normal maintenance, we should also remember the operation essentials. The grease is basically filled once in two hours to maintain the lubricity of the drill rod and piston striking surface. The piston is not easy to deform. If the piston deforms, it will also cause wear to the cylinder liner and oil seal. After the cylinder liner is worn, it will cause oil leakage, and at the same time, it will cause weak hitting If the cylinder liner is worn too much, the hammer will be scrapped, the wear of drill sleeve will be reduced, and the replacement cycle will be prolonged.

Scratch on the working surface: ① impurities mixed in the hydraulic oil; ② the gap between the guide sleeve of the drill rod is too large, and the guide sleeve is invalid. When the piston strikes on the drill rod, it receives an oblique reaction force, which can decompose an axial force and a radial force. The radial force can push the piston to one side, the original clearance disappears, the oil film is damaged, and dry friction is formed between the cylinder and the piston surface, resulting in scratch on the piston surface.

Working surface depression, cracks and cracks around the depression: ① carburized low alloy steel piston is the internal cause of impact face depression, cracks and cracks. Through a large number of investigations, we found that most of carburized low alloy steel piston failed due to impact depression, cracks and cracks. ② The hardness difference between the piston striking part and the drill rod striking part should be appropriate.