11/03/2024
Linear Motion: Ask the expert
Against the backdrop of rising energy costs, the need to increase productivity and reduce downtime is a key focus for manufacturers.
However, when it comes to selecting linear actuators for motion applications, there are some questions that may be raised when specifying an electric or pneumatic solution.
Here, Simon Gass, Product Marketing Manager, Actuators, from Norgren answers some of the most asked questions when it comes to pneumatic and electric linear actuation solutions.
Is the actuation market continuing to remain strong?
Put simply, for manufacturers needing to move a load quickly, reliably and, cost-effectively between two fixed points; or, for applications which are limited to a small installation space or are dealing with a hazardous operating environment (such as exposure to extreme temperatures or flammable areas), then specifying a pneumatic solution could be preferable.
Here, we’re seeing technological innovation, as seen in the Norgren ISOLine range, which brings with it an increase in performance. Providing an adaptive cushioning system (ACS), it automatically adjusts the cylinder cushioning for changing loads, so manual cushion screw setting is not required.
Suitable for a wide variety of applications, from heavy industrial to clean food and beverage and even rail, pneumatic actuators, such as the Norgren ISOLine, offer manufacturers a fit-and-forget solution which can efficiently perform at low pressures, while also lowering the overall weight of the machine.
In addition, with energy costs an ever-present concern, an option some manufacturers are considering is to upgrade to an energy saving actuator such as the ISO footprint compatible Norgren IVAC, which offers a compressed air usage saving of up to 50%.
What are some of the benefits of electric actuation?
While the operational benefits of more traditional pneumatic solutions are better understood, the growing use of electric actuation, in response to more complex machine requirements, means manufacturers and OEMs now have more choice for linear actuation solutions.
Electric actuation brings with it another level of precise control, flexibility, guaranteed repeatability, and force in comparison to similar size pneumatic actuators. It is proving increasingly popular in sectors such as packaging, material handling and automotive.
Electric actuators can provide the highest degree of precision-control over the linear motion stroke, offering unmatched performance when it comes to controlling speed, position, accuracy and repeatability. For example, accuracies of +/-0.02mm for repeatable positioning are possible with some ball screw drive technologies.
In addition, multiple intermediate positions can be achieved, and in-built positioning flexibility allows several actuators to move in unison, changing speed without the need to stop or overrun a position. Precise acceleration and deceleration control, as seen in the Norgren ELION Electric Actuator range, also allows the cylinders to glide into position without stopping abruptly, making electric actuation suitable for applications where vibration and disruptive movement is not acceptable. For harsh operating environments, such as the food and beverage sectors, and process applications including cement works, and powder transportation, OEMs need a solution which further enhances sealing protection. To this end, the Norgren ELION IP65 rod-style actuator conforms to the international standard for ingress protection from foreign objects and liquids, as defined by IEC/EN 60529.
Finally, electric actuation can make a significant contribution to lowering running costs and improving the operating environment. With electromechanical components efficiently converting electricity to mechanical power, energy savings and a reduction in energy consumption are possible as the motor is only energised when movement is required, or an external force is present. As a result, electric actuation helps create a cleaner and quieter operating environment.
What about the role of hydraulic actuation?
Interestingly, we’re seeing an increase in the number of hydraulic applications moving towards electric actuation. The main reason behind this is simply that electric systems are often less complex than hydraulic ones and there’s the obvious issue of potential oil leaks. Again, with the drive towards more sustainable processes, electric offers OEMs a more energy efficient form of linear motion.
Of course, it cannot replace all hydraulic applications, especially where high force is required. However, for lower force applications, we are seeing customers move away from hydraulics to electric.
How is the drive towards digitalisation impacting the actuation market?
The Industrial Internet of Things (IIoT) is increasing connectivity between machines and operators. Therefore, the ability to extract real-time data streams via networked sensor technology can help manufacturers monitor and analyse actuator performance.
Key indicators such as operating temperature, level of current and position can be quickly visualised and offer valuable insight to help identify ongoing running levels and avoid unwanted downtime, improving productivity and reducing cost.
Is there a role for both pneumatic and electric actuators?
Of course, while the benefits of electric and pneumatic linear actuators are clear, manufacturers must also recognise there may be applications that require both. These include large, multiple axis machines, where a combination of electric and pneumatic actuation can be appropriate as there may be both simple and complex linear motion positioning requirements.
To further support those working in industry to understand their exact application needs surrounding linear motion, Norgren’s team of industry experts have created an easy-to-use online application configurator tool to provide machine builders and end users with the ability to select and purchase correctly sized actuation solutions for the application in hand. For more information, click here