Sensors in printed wear-resistant parts indicate maintenance requirements and warn of overload.
Wear-resistant parts often have to withstand considerable adverse influences such as abrasive dust, high speeds or chemicals. So as to recognise the wear of special parts produced with additive methods, igus has used 2-component printing to create the possibility of manufacturing parts printed in 3D. Manufactured in filament printing, they warn against overload and report their maintenance requirements. What is special about them: for the first time, the sensors are directly "printed into" the parts. As a result, they not only have extremely short delivery times and low costs but also feature useful Industry 4.0 options.
Industry 4.0 stands for the progress of digitisation, and thus also the monitoring of machines and their components. In the worst case, just one component failure can cause production to come to a standstill. With the help of the Internet of Things (IoT), machines and components are meant to connect, communicate with each other and display possible error messages, giving people the chance to react in time. Therefore, igus has developed intelligent solutions for condition monitoring and predictive maintenance under the name of smart plastics. It is used for machine parts made of high-performance polymers, such as energy chains, cables, linear guides or also plain bearings. The result: the components do not simply go into "defective" status under harsh environmental conditions, but rather announce this defect as a need for maintenance. With this development, igus has established the integration of their machine elements into a smart production compatible with Industry 4.0.
Monitoring service life
You can precisely calculate the service life of all igus products with online tools. For this reason, igus has an on-site 3,800 square metre test laboratory.
At i.Cee - the software-based igus solutions for predictive maintenance - all data from the laboratory is used as a basis for calculating the estimated service life. To enable users to monitor their components during operation, igus has been offering smart plastics solutions for their energy chains and cables since 2016. Shortly afterwards, the intelligent slewing ring bearing and the smart linear guides followed, and in 2019 the first intelligent plain bearing made with injection moulding was introduced. The principle of the smart plain bearing: technology integrated in the bearing detects wear in advance and gives the user a signal in good time before the wear limit is reached. Maintenance can be planned in advance, and unnecessary replacement and unplanned machine and system failures are avoided. After many series of tests in the laboratory, igus developed the first isense standard range for its lubrication-free iglidur plain bearings in 2020. Here, the body of the plain bearing consists of two components: the internal, customised iglidur material and an outer hard polymer shell that protects the bearing. In order to measure the amount of wear, a sensor is used between the two components. "The catalogue range includes five materials with which we can cover a large part of highly stressed applications", says Stefan Loockmann-Rittich, Division Manager iglidur Plain Bearing Technology at igus GmbH. The FDA-compliant material iglidur A180, which is specifically designed for use in the food industry, the heavy-duty bearing iglidur Q2E for use in construction machinery and agricultural engineering, the all-rounder material iglidur G, the endurance runner iglidur J as well as iglidur P210 as a specialist for pivoting and rolling applications are also included. "We have primarily developed smart iglidur for difficult-to-access bearing points and for applications where no regular maintenance intervals have been planned."
Smart special parts from the 3D printer
But what about the monitoring of special parts? Here, igus offers a new solution with the 3D printer: additive manufacturing meets Industry 4.0. igus engineers have now succeeded in combining both in a single production step: for the first time, sensors are printed into the additively manufactured tribo-component using multi-material printing. "Long before the failure, the intelligent 3D printed component signals that a replacement is imminent. Furthermore, it can detect overload and stop the application immediately, thus avoiding further damage at the bearing point and the entire system", explains Tom Krause, Head of the Business Unit Additive Manufacturing at igus GmbH. Due to multi-material printing, also referred to as 2-component printing, the developers at igus are able to produce such intelligent special parts in only one work step. The sensor layer is applied to those parts of the component that will be subjected to load. The components are manufactured from iglidur I150 or iglidur I180 filaments and a specially developed electrically conductive 3D printing material that bonds well with the tribo-filament. The user can avoid high tool costs and receives the individual plain bearing within just five days.
Wear or load are monitored
Currently, two concepts are possible: if the electrically conductive material is located between the layers subject to wear, it can warn against overloading. Because if the load changes, the electrical specifications also change. The machine can be stopped and further damage can be prevented. To determine the load limits, the bearing must be calibrated accordingly. If, on the other hand, the conductor track is embedded in the sliding surface, the wear can be measured via the change in electrical specifications. Predictive maintenance is possible with the 3D printed component. This can involve one or several layers. The multi-layer method is particularly suited for parts that move in the z-plane. If the 3D printed components are also used in the pre-series stage, the collected wear or load data provide additional information about the service life of the individual component or the planned application in the series. This makes it easier to adapt and optimise the development process.
System connection according to customer requirements
For connecting printed intelligent wear-resistant parts, igus offers two possibilities of contacting. Either, the operator uses threaded inserts, via which the contacts can be screwed on, or there are open contacts at the outer shell of the plain bearing, as it is the case with isense plain bearing technology. The plain bearings have to be inserted in a housing and adjusted. Afterwards, the contacts are joined with a connector via a hole in this housing. The measured data of the sensors can be integrated by the machine and equipment operators into their systems in different ways. In the simplest case, light emitting diodes are used that indicate the condition temporarily or continuously in red or green. Furthermore, cost-effective isense evaluation units are available. Here, the condition is visually displayed and provided in the customer's local network via WLAN. The predictive information is really interesting for the customer. When the so-called i.Cee:local devices know the movement information, they can report a pending product replacement in good time or warn against unexpected events. Sensors and i.Cee:local devices can be connected with a wire or wirelessly. The latter is often used with moving plant parts without their own power supply (LoRa radio standard). From here, the integration of data to the IoT, cloud system or to the customer network is possible on a wire-bound basis. "The customers have the freedom to read the data and prepare the server information in the way that suits them best", explains Richard Habering, Head of Business Unit smart plastics.
World's first: igus prints intelligence into 3D manufactured components, making predictive maintenance possible for the first time at low cost, even for individual wear-resistant parts. (Source: igus GmbH)
For connecting printed intelligent wear-resistant parts, igus offers two possibilities of contacting. Either, the operator uses threaded inserts, via which the contacts can be screwed on, or there are open contacts at the outer shell of the plain bearing. (Source: igus GmbH)
The measured data of the sensors can be integrated by the machine and equipment operators into their systems in different ways. (Source: igus GmbH)
Wear detected in time with smart lubrication-free plain bearings from igus (source: igus GmbH)
From forklifts to packaging machines: isense plain bearings provide information about their wear and warn in good time before the stoppage of plant or machinery. (Source: igus GmbH)
Comments
Post a Comment