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  We all know that hydraulic oil, when pressurized into a hydraulic cylinder, generates significant pressure. This pressure is utilized in numerous mechanical devices. Below, we will discuss the knowledge about hydraulic cylinders. Hope this helps.

　　A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into linear reciprocating (or oscillating) mechanical motion. It features a simple structure and reliable operation. When used for reciprocating motion, it eliminates the need for a speed reducer, has no transmission gap, and provides smooth movement. Therefore, it is widely used in hydraulic systems of various machinery.

　　The output force of a hydraulic cylinder is directly proportional to the effective area of the piston and the pressure difference across it. A hydraulic cylinder essentially consists of a cylinder and cylinder head, piston and piston rod, seals, cushioning device, and exhaust device. Cushioning and exhaust devices vary depending on the specific application; other devices may be required.

　　Hydraulic cylinders typically consist of main parts such as a rear cover, cylinder, piston rod, piston assembly, and front cover. To prevent oil leakage from the hydraulic cylinder or leakage from the high-pressure chamber into the low-pressure chamber, sealing devices are installed between the cylinder and end caps, piston and piston rod, piston and cylinder, and piston rod and front cover. A dust cover is also installed on the outside of the front cover. To prevent the piston from hitting the cylinder head at the end of a rapid return stroke, a cushioning device is installed at the end of the hydraulic cylinder. Sometimes, an exhaust device is also installed.

　　Cylinder: This is the main body of the hydraulic cylinder, forming a sealed chamber with the cylinder head and piston to drive piston movement.

　　Cylinder Head: Installed at both ends of the hydraulic cylinder, forming a tight oil chamber with the cylinder. There are usually several connection methods, such as welding, threading, bolting, keyed joints, and levers, typically selected based on operating pressure, cylinder connection method, and operating environment.

　　Piston Rod: The main component for transmitting force in the hydraulic cylinder. The material is generally medium carbon steel (such as 45# steel).

　　Piston: The main component that converts hydraulic energy into mechanical energy, directly affecting the force and speed of the hydraulic cylinder.

　　Guide Bush: The guide bush guides and supports the piston rod. It has high precision, low frictional resistance, and good wear resistance, and must be able to withstand the pressure, bending force, and impact vibration of the piston rod. It has an internal sealing device to ensure a sealed chamber within the cylinder, and an external dust seal to prevent impurities, dust, and moisture from entering and damaging the seals.

　　Cushioning Device: When driven by fluid pressure, the piston and piston rod have significant momentum. Upon reaching the end caps and bottom of the cylinder, mechanical collisions occur, generating considerable impact pressure and noise. A cushioning device is used to mitigate this impact. Its working principle involves converting kinetic energy into heat energy through throttling of the oil (all or part) in the low-pressure chamber of the cylinder. The heat is then transferred from the circulating oil to the outside of the hydraulic cylinder.