In this article, MGA discusses the key factors to consider with regards to pneumatic cylinder selection. Covering basic knowledge like the working principle of pneumatic cylinders to more advanced theories like as pneumatic cylinder calculation formula, this guide will provide key insight for your decision-making process.
The working principle of pneumatic cylinders
There are many industrial applications which require linear motion during the operating sequence; the most cost-effective way to achieve this is with a pneumatic cylinder.
Before we get into the more technical aspects of pneumatic cylinders and the different types available, it is important to understand how they work and what function they help achieve.
The working principle of a pneumatic cylinder involves turning a source of stationary power into a useful output motion. These motions could be blocking, clamping, ejecting or applying force. Pneumatic cylinders use compressed air acting on a piston inside the cylinder to move along the linear path and achieve this goal.
In application, the body of the actuator is connected to a support frame and the end of the rod is connected to a machine element that requires movement. A control valve is then used to direct compressed air into the actuator to begin its process.
Pneumatic cylinder selection
Now that we have covered how a pneumatic cylinder functions, we can begin to cover the different types of pneumatic cylinders that are available.
One of the most important factors in your pneumatic cylinder selection process is to ensure that your actuator chosen will appropriately match the application it is used with, particularly with regards to the force required.
Aside from this, other qualities which should inform your selection should include it’s shape, material and size. To provide an example, if the application in question operates at higher temperatures, stainless steel cylinders would be an ideal match.
The most common pneumatic cylinders are rod-style cylinders, which consist of a piston and rod moving inside a closed cylinder. This type of actuator has two subcategories which should factor into your pneumatic cylinder selection process; single acting and double acting pneumatic cylinders.
A single-acting pneumatic cylinder uses a single air-port to allow compressed air to enter the cylinder and move the piston to the position desired. It also has an internal spring which returns the piston back to its starting position once the air pressure has been removed. A typical use for a single-acting cylinder might be assisting with heavy duty jobs such as lifting heavy materials. As such, they can often be found in pumps or hydraulic rams.
On the other hand, double-acting pneumatic cylinders have an air-port at either end and will move the piston forwards and backwards by the port that receives the high-pressure air. Double-acting actuators may be found in machinery such as steam engines, where both backwards and forwards motions would be required.
An alternative option to consider is rodless pneumatic cylinders. These are designed with the piston connected to an external carriage by a mechanical or magnetic coupling system. Rodless actuators are ideal for any applications that require a long stroke or where space is at a premium and can be used in an array of industries.
Pneumatic cylinder calculation formula
Now that we have covered the different types of pneumatic cylinders available, you should have a clearer understanding of what to consider in your pneumatic cylinder selection process.
You may want to consider applying the pneumatic cylinder calculation formula to your decision-making process. This is used for calculating the force in the cylinder. The general rule of thumb is force = pressure x area.
The force is measured in Newtons, the air pressure is measured Newton’s per millimetre squared and the area is measured in millimetre squared.
By following this equation, you will have a better understanding of how effective your chosen actuator can be.