Hydraulic cylinders convert hydraulic energy into mechanical energy, performing linear reciprocating or oscillating movements. They have a simple structure, operate smoothly during reciprocating movements, and are therefore widely used in various construction machinery, marine vessels, and machine tool industries.

Different machines require different types of hydraulic cylinders. Hydraulic cylinders are mainly classified into piston cylinders, plunger cylinders, and swinging cylinders, each with its own specific functions.

There are two types of hydraulic cylinder pistons: single-piston and double-piston cylinders. The single-piston hydraulic cylinder has a piston rod at only one end, with both ends serving as outlets and inlets for the hydraulic fluid, thereby enabling bidirectional movement, also known as a double-acting cylinder. Hydraulic cylinders are commonly used in construction machinery such as hydraulic excavators.

Dual-piston hydraulic cylinders have extending piston rods at both ends, with a composition similar to that of a single-piston rod cylinder. When the right chamber of the cylinder is filled with oil and the left chamber returns the oil, the piston moves to the left; otherwise, the piston moves to the right.

Hydraulic cylinders, with piston rods of equal diameter on both sides, have the same effective working area at both ends of the piston. If oil of the same pressure and flow rate is input into both ends, the piston generates equal thrust and reciprocating speed. Such hydraulic cylinders are commonly used in applications where the reciprocating speed is the same but the thrust is very small, such as on the worktable of a grinding machine.