Franke: Innovative winding technology for the ultimate electric car

In this segment of the electric car industry, customers expect performance, efficiency and reliability. With a six-figure price tag, these vehicles have to be the best of the best and able to travel long distances between charges.

How do you build an engine that is half the size of current gasoline engines but delivers over 600 hp – for a car capable of over 1,000 hp? Schaeffler ELMOTEC STATOMAT delivers that solution. The German company, based near Frankfurt, has been part of the Schaeffler Group since 2019 and is the global leader in winding machines for the automotive, industrial and household appliance markets.

Leader in flat wire shaft winding

This mechanical engineering company is a pioneer and driver of innovation in this technological field. In order to build these super electric car engines, Schaeffler ELMOTEC STATOMAT mastered the process of flat wire wave shaft winding. Compared with the traditional hairpin process, the flat wire wave is processed into a continuously mesh, significantly reducing the number of welds which are the primary cause of motor failure. These more compact windings lower electrical loss and result in more power and reliability.

Individual bearing assemblies with wire race bearings

To achieve successful stator winding, it’s essential to simultaneously lay flat copper wires from multiple directions without causing damage. Schaeffler ELMOTEC STATOMAT achieves this by employing twelve Franke bearing assemblies per winding machine. These assemblies are aligned and move linearly with each other, ensuring precision without tolerance errors, as highlighted by Dominik Knopp, project manager at Schaeffler ELMOTEC STATOMAT. The precision of Franke bearing assemblies enables these machines to maintain the required tight tolerances.

Franke’s wire race element technology allows for customizable assemblies, enabling selection of materials, dimensional flexibility, and load capacity to optimize performance. Designer Kai-Uwe Pahl lauds this flexibility, noting it provided ample room for system design according to development goals. Additionally, Franke wire race bearings boast compactness and high center clearance, as highlighted by Kai-Uwe Pahl, who explains that these bearings ensured sufficient winding space without exceeding machine dimensions. The lightweight aluminum material used in bearing housings further enhances precision by reducing moving mass.

Successful Collaboration

In order to optimize the bearing assembly designs throughout the developmental process, close collaboration between Schaeffler ELMOTEC STATOMAT and Franke was necessary. “We regularly discussed the state of affairs and all relevant stakeholders were present,” says Franke commercial consultant Heike Faustmann. The two teams were very open and transparently as they handled tasks and challenges. Their open communication helped to build mutual trust and understanding.

Fast and flexible responses

Franke account manager, Michael Bärstecher, points out that Franke’s skill and experience rose to meet the requirements of this demanding project. The employees involved in the project were satisfied to have successfully met the challenges and satisfied the customer’s requirements. Dominik Knopp from Schaeffler ELMOTEC STATOMAT stated: “We have direct contacts at Franke for all topics. We have always received well-founded answers to our wishes and questions quickly. Even with short-term changes in the course of the project, Franke was an understanding partner and reacted quickly and flexibly.”

For more information, please visit: https://www.franke-gmbh.com/news-stories/overview/