Pneumatic actuators are fundamental to many processing plants and manufacturers, selected for their ability to work tirelessly on compressed air with high force to speed ratios and a relatively low financial investment upfront. However, there is a raft of pneumatic actuators, including single- and double-acting, rod and rodless, linear and rotary.
Not only that, but they can be configured in a whole variety of ways depending on the process that they are driving. So, if you are asking yourself the question: how do I choose a pneumatic actuator? You are not alone. We have put together 5 top tips to help when choosing your pneumatic actuator.
Consider the directional force required for your actuator
Whether you want your pneumatic actuator to work only in one direction, or to have the ability to use force either back and forth or up and down, will dictate whether you should opt for a single- or double-acting actuator. Single-acting cylinders use one airport to let compressed air enter the cylinder to move the piston to the desired position. There is an internal mechanism to return the piston to the rest position when the pressure is removed, usually a spring. This means a single action actuator can only do work in one direction. Double-acting cylinders have an air port at each end and will move the piston forward and back by alternating the port that receives the high-pressure air. These actuators can do a full load in both directions. So, your first question is: Do you want your actuator to travel in both directions?
Think about the load that you need the actuator to move
How much work do you need the actuator to do? Pneumatic cylinders have no fine-grained control. All the force of the piston is supplied until the extent of the cylinder is reached. The theoretical force available in a pneumatic actuator is the piston surface area multiplied by the supplied air pressure. In single-action cylinders the return mechanism force must be subtracted. Your second question, therefore, is: how much load should my pneumatic actuator carry?
What is the required distance of travel for the load on your actuator?
The required distance for the load to move determines stroke length of the actuator. Actuators with rods tend to be better for extension of loads whereas rodless actuators have a stroke length roughly equal to that of the overall assembly but can carry a higher load. You need to think about how far you need your pneumatic actuator to travel each time.
Consider the working space available for the actuator
The amount of space available for the actuator to operate in defines either the cylinder and piston length or a rodless actuator’s physical dimensions. Rodless actuators have a smaller overall footprint and are therefore often favoured within processing environments where space can be limited. The question here, then, is: how much room do I have for my pneumatic actuator to work within?
What level of control do you need from your pneumatic actuator?
Rodless cylinders tend to have greater precision compared to other linear actuators, which is vital if you are looking for accuracy and repeatability. However, if your key attribute is speed or force, this may not be the best option.
When choosing your pneumatic actuator there are a whole variety of issues to consider. Space available and distance of travel, the precision required, the load type and weight and the directional force needed are just some of the factors you need to take into account. If you are still asking, how do I choose a pneumatic actuator? Why not speak to the experts?
Best Pneumatics have a vast range of pneumatic actuators available to select from, as well as the expertise and know-how to guide you in your choice. Call Best Pneumatics for a discussion on which pneumatic actuator will best suit your application on 01254 39055 or email [email protected].