2017 Award Winners
Award-winning project: Optimization of the manufacturing technology for Wiegand wires used as an energy source
Project partners: SEW-Eurodrive GmbH & Co. KG, Bruchsal | Steinbeis Transfer Center Materials Development and Testing (WEP), Wiernsheim
In order to develop energy-self-sufficient, contactless revolution counters, SEW-Eurodrive GmbH & Co. KG in Bruchsal has for many years been working on the concept of the ‘Wiegand sensor’ – a component which has the unique property of being able to serve not only as a signal transmitter but also as a power source. This involves using a high-energy pulse, independent of rotational speed, to power ultra-low-power electronics, which enable the shaft of an electric motor to be counted whilst the motor is de-energised. At the heart of the sensor is the Wiegand wire, which was patented by John Wiegand in 1978. When the thin metal wire, made of a ferromagnetic alloy, is subjected to a very specific, suitable cold-forming process, it acquires the property of being able to spontaneously change its magnetic axial orientation.
In collaboration with the Steinbeis Transfer Centre for Materials Development and Testing (STZ WEP), SEW-Eurodrive developed quality analysis methods to significantly improve energy efficiency and achieve an optimal manufacturing process with reliable results. Using a specially developed preparation methodology, the Steinbeis experts were able to visualise the different magnetic zones of the wire and publish these findings for the first time in the research community. In further investigations of meticulously prepared material samples, in addition to systematic microstructural analyses extending into the deeper microstructure of the Wiegand wires, insights were gained into the almost complete spectrum of properties (mechanical, thermal, magnetic). This essential comprehensive picture could only be achieved through the combined application of numerous materials science analytical methods, all of which are fully available to the STZ WEP in the materials laboratory at Pforzheim University.
The ongoing and mutually reinforcing collaboration between the two partners has now been recognised with the Steinbeis Foundation’s Transfer Prize – the Löhn Prize. Ultimately, Wiegand wires can be produced to a previously unattainable standard of quality, which has the potential to revolutionise the multi-turn angular position encoder market in the near future.