Oil cylinder, also known as hydraulic cylinder, is a hydraulic mechanical component, widely used in machinery, metallurgy, shipbuilding, mining, aviation and other fields, for the realization of mechanical movement and force transmission. The working principle of the cylinder is to use the high-pressure oil of the hydraulic system as the driving force, controlled by the valve, the oil enters the cylinder, and the piston in the cylinder generates thrust or tension, so as to realize the movement, lifting, clamping and other actions of the mechanical device. The cylinder is usually composed of cylinder, piston, sealing ring, thrust, connecting rod, guide rod and other components.