How to maximise your pneumatic cylinder’s performance
When designing linear motion systems, pneumatics offer a simple, flexible and cost-effective solution. Furthermore, when you work with Matara, they can be fully specified to your needs, allowing for high durability and little maintenance, resulting in systems that can run for years without issue. This alone is why our range of pneumatic components used in these systems are so popular across a wide variety of industries including food processing, automotive, woodworking and ceramics.
Often, when specifying your pneumatic linear motion system, pneumatic cylinders act as a key component in your circuit. Therefore, it is imperative that you take into consideration multiple factors when specifying and installing your cylinder.
Correct cylinder selection
In traditional pneumatic cylinders (ISO VDMA type), a rod is used to push and pull the load from the piston. When specifying your standard cylinder, you must think about whether your cylinder needs to be single-acting or double-acting.
Single-acting means that air is only supplied to one side of the piston, resulting in an internal spring return is needed to bring the piston back to its original position. This often equates to a less compact solution due to the size of the spring, and a more inconsistent output force due to the resistance force of the spring. As a result, double-acting cylinders are seen as the industry standard.
Double-acting cylinders allow for air to be supplied to chambers on both sides of the cylinder. Whilst this may be seen as a negative, due to the increase in air consumption, this configuration allows for better control and enables higher cycle rates.
Compared to a traditional pneumatic cylinder, a rodless pneumatic cylinder can give a more compact solution. This is because instead of using an extended rod, the rodless pneumatic cylinder moves the load parallel to the piston. As a result, you can achieve the same stroke as a traditional cylinder but in less space. Furthermore, by using a rodless pneumatic cylinder, you eliminate the possibility of rod buckling.
When choosing your cylinder, you also have to take into account the environment that it is going into. Some key questions to ask yourself may be:
- Will you have to select specialised seals to that can accommodate high-temperature environments?
- Are you accounting for any corrosive materials that may come into contact with the cylinder body?
- Is there any swarf or particles that may impede the linear movement?
- Does your factory have adequate air pressure, or will pneumatic boosters, or duplex cylinders need to be used?
Once you have selected your cylinder type, the next step would be to ensure that your cylinder has the correct bore size and stroke length for your application.
Firstly, pneumatic cylinders with larger than needed diameters can consume excessive amounts of air and increase the application’s cycle time. Furthermore, this results in a system that costs more to purchase and maintain over time. However, it is often advised that in order to overcome internal friction, you should allow for a safety margin when handling the calculated moveable load.
Secondly, if you over-specify a stroke length, you will waste energy and add to cycle time. This is because of the excessive travel distance and material weight. Furthermore, you may find complications when trying to install and mount your cylinder due to excessive space being taken up.
Take care when installing
Upon planning for the installation of your cylinder it is important to consider which mounting option is best for your application in order to maximise efficiency. For instance, if you are looking to have a quick and easy installation of a standard pneumatic cylinder, foot and flange mounting options are often preferred. However, if you are expecting a centred load, a trunnion or rear clevis mount may provide a solution to the side load stress that may occur otherwise. Furthermore, when using a rear clevis, on a horizontal mounting, a centre trunnion option should be installed at the point the cylinder balances. This is because it would help to counteract the bending moment.
Secondly, the load that the cylinder will be moving should be taken into consideration, especially when applying a long-stroked cylinder. This is because an unsupported load creates instability, which can lead to rod buckling and a breakdown in your production line. As such, it is important to consider the external guiding of the load you are moving. This can be achieved by mounting the load on linear motion components such as linear rail and guides or linear shafting. However, it is important that when installing the cylinder and external guides, both are aligned correctly so that the cylinder does not jam or stop completely.
Create an efficient air preparation system
Often, pneumatic circuits are designed without due care and attention to energy and efficiency, often resulting in an increase in incurred maintenance costs in the long run. Furthermore, it is often seen that energy is wasted when supply pressure is increased, as it is often wrongly believed that it increases the performance of the cylinder.
To truly build an efficient pneumatic system, a clever installation of pressure sensors and regulators should not be over-looked. For example, by thoroughly planning the installation and situating key components close to the cylinder, you will be less likely to run into air pressure issues. Furthermore, efficiency and accuracy are becoming ever more achievable with the introduction of electro-pneumatic components into the UK market.
Secondly, it is advised that filtration and lubrication units are to be introduced into a pneumatic circuit to improve the air quality. This is particularly the case when using pneumatic cylinders, as often poor air quality cause in corrosion to cylinder seals. As a result, this could lead to an incurred cost from maintenance and downtime in production.
Pneumatic cylinder solutions from Matara
Contact our expert team at Matara UK to find out more about our range of standard and rodless pneumatic cylinders. Get in touch with the team by calling us on +44 (0)1684 850000 or email firstname.lastname@example.org.