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

Different machines require different types of hydraulic cylinders. Hydraulic cylinders are mainly categorized by their structural forms into piston cylinders, plunger cylinders, and swing cylinders, each type serving different functions.

There are two types of hydraulic cylinder: single-rod cylinder and double-rod cylinder. The single-rod cylinder has a piston rod only at one end, with both ends serving as the outlet and return ports, 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, it moves to the right.

Hydraulic cylinders feature identical piston rod diameters on both sides, resulting in equal effective working areas at the piston ends. When the same pressure and flow of oil are introduced 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 minimal, such as on grinding machine tables.