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Rodless cylinders are considered to be excellent for operation within automatic applications. In this article, we take a look at the options available for pneumatic actuators, their use in automatic applications, and exactly how a rodless cylinder does work. 

First, let’s get a quick refresh on Pneumatic actuators and how they are the unsung heroes of automatic applications. In recent times, electric actuators have taken the starring role due to their precision control and acceleration/deceleration rates, and hydraulic actuators still steal the show where loads are weighty. 

However, where an application needs clean operation, minimal financial investment and high force to speed ratios, pneumatic actuators remain the most effective equipment for the job. That is the reason you will find them throughout processing and manufacturing plants in a broad range of operations. 

How do pneumatic actuators work?

An actuator converts energy – usually electrical, hydraulic or pneumatic – into mechanical force to enable controlled movement. In the world of automation, actuators are used in robotic arms, in shifting loads between processes, for adjusting the height of equipment such as saw blades, or for jobs within the packaging process. Any process that requires movement is likely to involve an actuator of some kind. 

A pneumatic actuator uses pressurised air or gas to convert potential energy into rotary or linear motion. For the majority of pneumatic actuators in automatic applications, they have linear stroke setups with two or more piston stops. It is common to use air cushions or damping seals to minimise the stop times.

Why use a pneumatic actuator?

As well as being cost-effective and offering an excellent force-speed ratio, pneumatic actuators perform well in situations where sparking from an electric actuator could cause a potential fire hazard, such as with flammable materials or chemicals. They are also especially appropriate for the rapid operation of valves. 

Pneumatic cylinders are often the preferred option in industrial settings because compressed air is readily available. They can function between 15 and 110 psi and come in both single- and double-acting variants. 

Single-acting actuators will only move loads in one direction; they are of a straightforward design, which is an advantage where ruggedness and reliability are required. 

Double-acting actuators are more common within automated applications; they move loads both back and forward or up and down, providing an excellent level of control overload movements. 

What are the benefits of a rodless actuator?

Rodless actuators are extremely common in processing and manufacturing environments. Since the housing contains the entire actuator assembly, the overall footprint of the product for any given movement is smaller than a conventional linear actuator. This gives them greater structural strength and load-bearing characteristics. 

Rod-type cylinders carry restrictions in terms of the ability to offer long strokes; because the cylinder rod is unsupported, it tends to flex in the extended position, which can lead to premature wear and the need for more regular maintenance. Rodless cylinders, however, are held within a self-contained unit, which means fewer components and a longer lifecycle as well as more controlled, precise movement. 

Rodless pneumatic cylinders can be configured in endless ways to suit any number of production processes, and it is this versatility that makes them such a popular choice. 

How does a rodless cylinder work?

With rodless cylinders, an internal piston moves within the cylinder barrel where compressed air drives it. Depending on the air pressure on each port, the piston moves in either direction along the length of the cylinder. The piston is attached to a carrier that is attached to a load and moves with the piston. There are usually buffers at both ends of the barrel to prevent hard stops after full travel. This design gives the advantages of having a stroke length that is comparable to the assembly’s size, no rod buckling to worry about with high loads or long strokes, and it delivers the same force in both directions.

Clients often ask us questions such as how does a rodless cylinder work and what are the benefits of pneumatic rodless actuators in an automation environment? We hope to have offered some explanation in answer to those questions.

We have a complete range of rodless actuators in stock and the expertise to offer guidance on which one would be best suited to any given application. Contact Best Pneumatics on 01254 390555 or [email protected].

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Categories: Guides

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].

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Categories: Uncategorised

If you are wondering what type of pneumatic actuator is best suited for your application, you have come to the right place. With a range of linear and non-linear pneumatics actuator products available, each being designed to convert energy in either a linear or rotary motion, knowing the difference between rodless cylinders, mini rotary actuators and stainless steel actuators is critical.

In this article, we look at the key differences between rodless cylinders, mini rotary actuators and stainless steel cylinders, as well as the typical applications each pneumatic cylinder/actuator serves.

What Pneumatic Actuator Is Suited To My Fluid Power Application?

Here at Best Pneumatics, we have a vast range of pneumatic actuators to suit most application requirements. Whether you operate in a potentially explosive environment or you require a bespoke pneumatics actuator to generate energy using compressed air or gas, we have the solution for you.

With more than 30 years of experience in providing pneumatics actuators to both customers and suppliers, our team of experts will listen to you to understand all of your pneumatic requirements. Here are some popular pneumatic actuators available to purchase on our online store and common uses.

Mini-rotary actuators

Mini-rotary actuators are designed to provide a quick and efficient rotary movement, also referred to as a turning movement. Known for being highly durable, mini-rotary actuators offer long stroke lengths and are generally lighter in weight. This type of pneumatic actuator is typically suited for several applications including, robotics and material handling.

At Best Pneumatics, we supply mini-rotary actuators from the world-renowned brand, SMC and offer both rack and piston and vane rotary actuators. With different mini-rotary actuators available including the CRJ Series and CRA1-Z Series, whatever sized mini-rotary actuator you require for your application needs we have a wide range of options available.

Rodless cylinder

When you have a long stroke application or require a small, compact device tailored to the operation of your application then it could be that one of our rodless cylinders is the solution for you. With magnetic coupled rodless cylinders available (significantly undergone size improvements in recent years) and even rodless cylinders suitable for high precision applications our range really does hold the answer to your application challenges. We also have a range of linear and cam follower guide rodless cylinders, amongst many others.

Stainless steel actuators

If you are looking for the type of pneumatic actuator that is best suited for highly corrosive environments, look no further than our stainless steel range of pneumatic actuators. These devices ensure long-lasting pneumatic actuator life and offer high wear resistance. Alternatively, if you operate in potentially explosive environments, we stock pneumatic cylinders with ATEX approval, a certification ensuring your pneumatic actuator is incredibly safe.

Choosing a pneumatic actuator for your application

At Best Pneumatics, we have a wide range of pneumatic actuators including ISO cylinders, and other popular models. As proud suppliers of SMC, if you aren’t quite sure which pneumatic actuator your industrial application requires, contact us at [email protected] or on 01254 390555.

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Categories: Guides

Understanding the difference between hydraulic and pneumatic cylinders is important when it comes to making the product selection and the impact on the throughput of your application. In this article, we look at the key differences and similarities between the two and weigh up their pros and cons to show why pneumatic cylinders are the superior choice in most circumstances.

While both have their advantages and disadvantages, as well as mechanical similarities, we believe choosing pneumatic cylinders have the edge when it comes to efficiency, speed and performance reliability. Here are the key differences between hydraulic and pneumatic cylinders that will justify this preference.

How Pneumatic Cylinders Work

Pneumatic cylinders are dependant on an air compressor, which is used to draw atmospheric air through an intake valve that then feeds through to a receiver tank. It is here that this atmospheric air is then compressed, something that cannot be achieved using fluids as you would with hydraulic cylinders, enabling high-pressure density to be achieved through the exertion of force.

The compressed air passes flow through to the pneumatic actuator, where it is transferred into mechanical energy and used to initiate motion. Now, this process does work in much the same way as it does within a hydraulic system with the same end goal in mind. So what is the difference between hydraulic and pneumatic cylinders that make pneumatic the better choice?

Limitations Of Hydraulic Cylinders

When compared to pneumatic cylinders, a hydraulics cylinders biggest drawback is the fact that the hydraulic oil used faces considerable energy losses when flowing through restricted spaces. There is also higher rates of resistance than you would experience with the compressed air used in a pneumatic cylinder.

Furthermore, due to the fact air is released during the use of hydraulic oil, a hydraulic cylinder struggles to deliver the high actuation velocities that a pneumatic cylinder can, thanks largely to its inability to expand at higher speeds and with greater force.

Why Choose Pneumatic Cylinders Over HydrauliC

Of course, there are scenarios where an argument can be made for the use of hydraulic cylinders over pneumatic cylinders. This is largely due to the hydraulic cylinders ability to sustain operation with few energy losses. However, for us, pneumatic cylinders hold the lion share of the advantages between the two.

Some of the key advantages to pneumatic cylinders include the following:

  • Lower upfront costs
  • High levels of durability
  • High mechanical reliability
  • Reduced maintenance

All of the above are important benefits for a plant manager to consider when managing the function of their application. These advantages also mean that pneumatic cylinders are also the cost-effective choice, and this coupled with the fact they are flexible for use across a wide range of industrial-scale applications puts them out ahead of the hydraulic alternative.

To learn more about our pneumatic cylinder offering and to purchase online, visit our Pneumatic Actuators page. Alternatively, if you need further support with your application or wish to carry out a direct purchase you can contact us by email on [email protected] or by calling us on 01254 395 000.

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