The rotary function in Koppert's so-called cup filler is no longer driven entirely pneumatically, but using the rotary drive unit ERMS from the Festo Simplified Motion Series. This allows Koppert's customers to benefit from the simplicity of pneumatics but the speed and accuracy of servo technology. Moreover, the total solution provides all the possibilities to collect data for optimisation and maintenance purposes.
From pneumatic to electric
To stay ahead in its own market, Koppert's engineering department is always keen to improve or expand its portfolio. Engineer Roshan Gangapersad, for example, works daily on innovative ideas for, on the one hand, standard machines or, on the other, specials commissioned by specific customers. Packaging machines, among others, have his attention.
"Roughly speaking, we have two packaging machines," he points out. "The Multipacker, and an XL version of that, and the fully automatic cup and bucket filler. The latter is designed to spring stacks of cups and then place them under a fixed filling position. After filling the pack, for example with snack vegetables, a lid is applied and pressed on. It is also possible to apply a printed label. Finally, the packaging goes onto a conveyor belt for further processing or transport."
Increasing speed
The various processes throughout the filling, sealing and disposal process were previously carried out purely pneumatically. This included the use of a valve island, pneumatic (rotary) cylinders and valves and an air conditioning unit. A fine and robust solution, but with the desire to increase the speed of the process by running the rotary cylinder faster, the company ran into the limits of pneumatics. The engineers were therefore keen to switch to an electric drive and enlisted the help of Festo to help with sizing and selecting the right components.
"We looked at different solutions always encountered limitations. In terms of speed and accuracy, for example, a servo motor was a very attractive solution. This just does NOT fit in with our desire to keep the machine simple for our customers. If our customer wants to change the actuator because he is going to run a different product, he should be able to do this easily, efficiently and, of course, safely. However, when using a servo motor, you would have to bring in a trained electro-mechanic to properly disconnect and reconnect the wiring and safely put the actuator back into operation. After all, you are also working with 230 VAC."
As an alternative, Festo proposed the rotary drive unit ERMS. This unit is part of the Simplified Motion Series (SMS) that Festo specially developed as the answer to electrification. Each component in this series is a complete system consisting of a shaft, (servo) motor and matching controller. All elements are characterised by simplicity and are tailored as a total solution to realise point-to-point movements. These can be controlled for power and speed by manually entering the parameters directly on the device. No complex software, no control cabinet and no 230 V AC voltage but a safe 24 VDC. It only requires two cables: one for powering the motor and one for the control and logic signals.
To make the elements from the SMS suitable for seamless integration into a variety of machines and systems, control is via digital IO similar to pneumatics, or via IO-Link. Koppert opted for IO-Link because it enables more. For example, parameters can easily be read and adjusted remotely. The same applies to the logged process values or the end-position setting. Moreover, IO-Link offers the possibility of positioning with the Simplified Motion Series and commissioning is simple thanks to the plug&work® principle.
For the customer
Roshan: "This proposal allowed me to realise exactly the solution I needed. Precisely because the ERMS is an integrated solution, replacing this turntable is simple. It does not even require a separate electro-mechanic; at our customers the much more frequent ‘mechanical’ mechanic or even the machine operator can take care of this operation. It is a matter of reading the required values, disconnecting two cables, exchanging the actuator and reconnecting the cables."
Besides the easy and quick exchange of the ERMS, the company sees great advantages in using IO-Link to access the available data. By monitoring voltage and current, among other things, upcoming failures can be identified at an early stage. For example, a current that keeps rising can indicate misalignment or increasing friction. Roshan: "The great thing is that you can also read this data remotely which means that if necessary when there are problems, we can log in to our customer's premises, and see directly whether we can use this data to identify the cause of the problems."
For Koppert
Finally, the solution is also a pleasure to work with for the machine builder himself. For example, the turntable features a sealed hollow shaft that allows an integrated feed-through for pipes and hoses. Furthermore, it provides a standardised mounting interface and integrated end-position detection. This makes installation during machine assembly easy.
Roshan concludes, "I am very happy with this final result. Through good consultation sessions with Festo and the combination of their expertise and our knowledge of our customers, the machine has become faster but not more complex. A good starting point to see where we can use the SMS even further. Soon, for example, we will apply different Simplified Motion actuators such as the EPCS for linear motion. An ideal concept for a variety of machines."