How To Improve The Service Life Of Hydraulic Cylinders?

1. In the use of hydraulic cylinders, measures to prevent the intrusion of pollutants should be added, and measures should be taken to control the intrusion of pollutants into the cylinder, such as adding efficient air filters in the breathing holes of the fuel tank, filtering new oil, and setting good anti- In addition to the dust seal ring, etc., it is also necessary to improve the anti-pollution ability of the hydraulic cylinder itself.

2. In terms of design, improve the structural form and material of the seal product, and adopt the seal structure form combining the combined seal product and the hybrid seal, the life of the hydraulic cylinder will be significantly prolonged. The wear ring and slip ring are generally made of PTFE+graphite. Because pure PTFE is prone to plastic creep, it is only suitable for hydraulic cylinders with low pressure and low wear resistance. If the sealing ring used is filled with graphite to form a new composite material, the wear resistance and hardness are increased by 2 to 3 times, the ability to resist plastic creep is increased by 2 to 3 times, the initial deformation caused by the load pressure is reduced by 30 to 60%, and the rigidity is improved. 2~3 times, the thermal dimensional stability increases by 2 times, and the hardness increases by 10~15%. The elastic force of the O-ring seal makes the sealing slip ring close to the sealing surface, and the sealing pressure is generated to achieve the sealing effect. When the internal hydraulic pressure increases, the O-ring seal will be further deformed to squeeze the slip ring, thereby increasing the sealing pressure and improving the sealing effect. The structure has the characteristics of low friction coefficient, good wear resistance, automatic compensation for wear and absorption of hard particles in the oil cylinder, and can achieve complete sealing effect. If the seal of the piston rod adopts a mixture of O-ring + Yx-ring, O-ring + Yx-ring is mixed In order to prevent internal pressure between the Yx-ring and the O-ring seal, it should be processed in the middle of 1 ~5.1 vent holes. Experience has shown that when the piston rod is retracted into the cylinder, the "oil leakage" (low-pressure oil film accumulation) that exists between the two seals is brought back into the cylinder, and no leakage flows out through the small holes. With this structure, the oil film of the piston rod can be controlled to a small extent regardless of the working condition of the hydraulic cylinder. The compression amount (dynamic seal) of the O-ring is generally controlled at about 10% of its cross-sectional size.

3. In terms of the selection of accessories, the material, shape and compression amount of the seal have a great influence on the service life and working efficiency of the hydraulic cylinder. In addition to reliable sealing, it should also have a longer service life and less friction. loss. At present, there are many manufacturers of seals in China, and it is also crucial to choose reliable and stable seals.

4. In terms of manufacturing and processing, after the surface of the piston rod is chrome-plated, the post-plating polishing should be changed to the post-plating polishing method. Although this needs to increase the thickness of the coating before grinding (generally about 0.02 in the diameter direction), it can be chrome-plated very well, and it tests the bonding force of the coating. In addition, due to the microscopic unevenness of the grinding surface, lubricating oil can be stored in the valley, which not only improves wear resistance, but also prolongs the service life. Such as sleeve cylinder products, there is a big gap between the service life of post-plating polishing and post-plating polishing, especially in mass production. Strictly clean the door flashes and burrs of mechanical components, especially the edges and small metal burrs at the sealing groove, and strictly clean them before assembly. Rolling is used for finishing the bore of the cylinder, which can significantly improve the fatigue strength and stress-corrosion resistance of the surface of the cylinder. The roughness of the friction surface is generally controlled between Ra0.4 and 0.8.