In order to help you understand the cause of hydraulic cylinder failure, the following are the important things that make these hard-working actuators unable to work, so that you can better avoid hydraulic cylinder failure. This articleZhongyou Heavy IndustrySeven major reasons for the failure of the hydraulic cylinder.
1) Leakage seal
The seal is made of soft material and is the weak part of any cylinder. This failure is common for many reasons. Heat can cause them to decompose, and they may be damaged by scraping piston rods, or rupture due to pressure peaks. They are also subject to chemical corrosion and/or wear from dust and abrasives. Sealing failure is easy to detect. When the rod is wet and has an oil ring, and dust and debris are deposited on the wet area, dust may accumulate around the gland. You may also find fluid deposits under cylinders or machines.
2) Fluid contamination
The fluid running the cylinder is always at risk of being contaminated by debris and abrasive particles, which can cause damage to almost all components. It can block the ports, damage the surface finish of the cylinder rod, accelerate seal wear, and enter between the piston and the work surface. Hydraulic oil will naturally degrade over time, but poor machine conditions and problems such as wiper seals can increase the chance of hydraulic oil contamination.
3) The piston rod has scratches
This is the common one. The condition of the piston rod is extremely important for the service life of the hydraulic seals, so it is very important to keep them in good condition. However, this is not always easy to do, especially for cylinders working in extreme environments. In such extreme environments, objects may come into contact with the chrome surface of the piston rod and form deep scratches with very sharp edges. As the cylinder extends and retracts, the seal passes over these sites and is rapidly sliced and damaged. Seal leakage is inevitable and will happen soon. Fortunately, the damaged piston rod can be re-plated to restore the surface finish.
4) Bent piston rod
A bent rod occurs when the diameter and material strength of the rod are insufficient to withstand the load applied to it. When this happens, components such as pistons and seals will not align and lose the ability to control hydraulic fluid pressure. Hydraulic oil leakage is an inevitable result.
5) Barrel expansion
The expansion of the cylinder tube is usually caused by insufficient wall thickness and/or material strength for the working pressure of the cylinder. Expansion occurs when the cylinder is deformed, and the correct tolerance between the piston seal and the pipe wall is lost, allowing high-pressure fluid to bypass the seal. This high fluid velocity can lead to erosion of the seal, including localized heating caused by the pressure drop across the piston, resulting in reduced seal life.
6) Nicks of cylinder diameter
The cylinder hole nicks are manifested as heavy wear or deep cuts on the inside of the hole wall. This is typically evident at the barrel where the piston is in the fully extended position, and less support results in increased forces and friction. Cylinder bore scoring is common in long stroke cylinders. Incorrect cylinder installation or failure to accommodate certain changes in alignment may also increase the occurrence of cylinder scratches. In some applications, the cylinder will withstand greater lateral forces, which may cause the rod to become stuck in the barrel, causing the cylinder to score.
7) Patchwork weld
Tail welding is a catastrophic failure, which means that the welding surface (such as the mounting point) breaks or separates. Cracked welds are always a serious problem, and if left untreated, it may cause catastrophic consequences, which may cause personnel injury or equipment damage. Tight welding is usually a signal that the force applied to the cylinder is too large or abnormal. There are many situations that can cause this result, such as poor condition of the machine or hydraulic system, external impact or improper operation.
Hydraulic cylinders are subjected to huge forces throughout their service life, which means that they are always at risk of failure. However, it is important to understand why hydraulic cylinders fail in order to anticipate problems during the production process and reduce the occurrence of unexpected maintenance. In general, a structured proactive maintenance plan will help avoid many common things that can cause hard-working actuators to fail.