What is the pneumatic cylinder?
A pneumatic cylinder is a mechanical device designed to convert the energy of a fluid (either compressed gas, typically air, or hydraulic fluid, such as oil) into linear mechanical force and motion. It is a fundamental component in pneumatic, hydraulic, and some mechanical systems, widely used across industries for tasks involving pushing, pulling, lifting, clamping, or moving objects.
Pneumatic air cylinder serves as a type of air operated actuator in pneumatic components that uses compressed air to operate a piston to produce linear or rotary motion. At its core, a basic pneumatic cylinder consists of several key parts: a cylinder barrel (the main body), a piston that fits tightly inside the barrel, a piston rod connected to the piston (extending out of one end), end caps (sealing the ends of the barrel), and seals (to prevent fluid leakage). When pressurized fluid is introduced into one side of the piston, it creates a force that moves the piston either forward (extending the rod) or backward (retracting the rod), generating linear motion.
Pneumatic cylinders are categorized based on their working fluid: pneumatic cylinders use compressed air, while hydraulic cylinders rely on pressurized liquid. They vary in size, from small, precision pneumatic cylinders in medical devices to large, heavy-duty ones in construction equipment or industrial machinery, but all share the core function of translating fluid energy into controlled linear movement.
There are various types of pneumatic cylinders, classified based on their structure, function, and application scenarios. Here is an explanation of the common types:
1. According to Structural Form
Piston Pneumatic cylinders
These are the most widely used pneumatic cylinders, where the piston moves back and forth inside the pneumatic cylinder barrel to output force or displacement.
Single-acting pneumatic cylinders: There is only one air inlet at one end. The piston is pushed in one direction by air pressure, and the return stroke relies on a spring, gravity, or external load. They have a simple structure and low cost but feature asymmetric output force. They are suitable for short-stroke and light-load scenarios (such as clamping devices).
Double-acting pneumatic cylinders: Both ends of the pneumatic cylinder barrel have air inlets. The piston is driven to reciprocate by alternating air intake, with both forward and reverse directions powered by air pressure. They offer large and symmetric output force, customizable strokes, and are widely used in automated production lines, machine tools, etc.
Rotary Pneumatic cylinders
They output rotational swing motion around an axis (usually with an angle less than 360°) instead of linear displacement.
Principle: Air pressure drives a vane or gear mechanism to convert linear force into swing torque.
Applications: Scenarios requiring angular positioning, such as valve switching and rotary joints of manipulators.
Rod Guided pneumatic cylinders: Equipped with guide rods or linear guides to ensure stable movement of the piston rod and resist lateral loads, suitable for precision positioning.
Rodless pneumatic cylinders: The piston is embedded in the pneumatic cylinder barrel, and the load is driven by a slider connected to the piston, saving installation space. They are used in occasions with limited axial space, such as material conveying lines.
Compacts air cylinder:
It is a cylindrical metal part used to guide the piston to perform linear reciprocating motion inside it. It is designed to be lighter and thinner. Compared with traditional pneumatic cylinders, it can occupy less space and can effectively save installation space. It is particularly suitable for occasions with limited space and releases greater flexibility for equipment structure design.
Mini Air cylinders:
Mini aircylinder is a small pneumatic or electric actuator with compact size and high performance. It uses compressed air as the power source. When compressed air enters the cylinder through the air inlet, it pushes the piston to move linearly in the pneumatic cylinder, and then drives the piston rod connected to it to extend or retract, realizing the pushing, pulling, lifting, clamping and other actions of mechanical parts. By controlling the direction and flow of air intake and exhaust, the movement direction and speed of the piston can be accurately controlled.
