Pneumatic Cylinders

A pneumatic cylinder—also called an air cylinder—is a linear actuator that uses compressed air to generate motion and force. It converts the potential energy stored in compressed air into mechanical work by moving a piston within a sealed barrel.

Core components

• Barrel: The cylindrical housing that guides the piston.
• Piston: Separates two air chambers and translates air pressure into force.
• Piston rod: Connects the piston to the external load to transmit force.
• End caps (heads): Seal the barrel ends and provide ports for air.
• Seals and bearings: Keep air contained and reduce friction/wear.
• Ports: Connect to the pneumatic circuit (e.g., supply and exhaust).
• Mountings: Fixtures (e.g., feet, clevis, trunnion) to attach the cylinder to machinery.
• Optional features: Cushions, magnetic piston for sensing, rod scrapers/wipers, integrated
guides.

How it works (principle of operation)

• Compressed air enters a cylinder chamber via a port.
• Pressure acts on the piston area, producing force \(F\).
• The piston moves, extending or retracting the rod, doing mechanical work on the load.
• Exhaust air leaves through the opposite port (and through silencers/flow controls as needed).

For a basic double‑acting cylinder:

• Extend: Pressurise the cap-end chamber; exhaust the rod-end.
• Retract: Pressurise the rod-end chamber; exhaust the cap-end.

For a single‑acting cylinder:

• Pressurise to move in one direction; an internal spring or external force returns it when air is vented.

Pneumatic cylinders are widely used due to their simple, economical and durable design. They can produce immense force over a broad range of velocities, making them a popular choice for a wide range of applications. Pneumatic cylinders are commonly used in automotive, manufacturing and engineering industries and some of the most common uses of a pneumatic cylinder include: • Air brakes on cars or buses • Moving items from a conveyor belt • Opening an industrial door • Lift an item to join another process Pneumatic cylinders are available in a wide range of materials and dimensions. The size, style and configuration of a pneumatic cylinder will depend on the desired application.

While the basic use of a pneumatic cylinder is to generate force and motion from air pressure through an influx of pressurised gas, the specific role of a pneumatic cylinder will depend on the application of the product. In manufacturing industries, pneumatic cylinders are often used for heavy lifting and opening valves and doors, taking things on or off conveyor belts and lifting heavy objects. However, they have a different role when applied to the automotive industry, where they are used for suspension and brakes on cars and trucks.