Basic Structure of Hydraulic Cylinders

　　The main parts of a hydraulic cylinder include the cylinder head, cylinder cap, cylinder tube, piston, piston rod, guide sleeve, seals, and tie rods. The cylinder head and cap are usually made of rolled steel or cast iron. The cylinder tube is generally made of seamless steel pipe, with an inner hole processed to a high degree of smoothness to reduce internal friction and extend the life of the seals.
　　The piston is mostly made of cast iron or steel, fixed to the piston rod using various methods. Exhaust and buffering are options on most cylinders and can often be added without changing the profile size. The piston rod is typically made of high-strength steel, surface carburized, ground, polished, and chrome-plated to withstand wear and corrosion. Corrosive atmospheric conditions usually require a stainless steel rod, which can be chrome-plated to withstand wear or first nickel-plated and then hard chrome-plated to meet corrosion resistance requirements
　　. The guide sleeve supports the piston rod as it moves back and forth and is mostly made of ball-milled cast iron, usually removable without disassembling the entire cylinder. The rod seal device typically includes an external dust ring to remove dust and contaminants from the rod and prevent them from being drawn in, a main seal to seal the internal hydraulic pressure of the cylinder, and a hydraulic buffering ring in high-pressure cylinders to reduce the pressure on the main seal, improving the sealing effect and life of the main seal.