Efficient lightweight motors for electric vehicles

For the widespread implementation of electromobility, cost-effective and flexible production of efficient electric drive technology is an integral component. Among other things, new lightweight construction concepts can reduce the vehicle weight and thus decrease energy consumption during acceleration. In addition to the existing lightweight construction areas, such as the body, future efforts will also focus on optimizing the weight of the electric motor. Developing series-ready production technologies is the goal of the "ProLeMo" project, in which the Karlsruhe Institute of Technology (KIT) is involved.

While current stationary electric motors already achieve a high efficiency of up to 95 percent, realizing a batch and variant-flexible series production remains a major challenge for manufacturing technology. At the same time, the aim is to increase the ratio of motor power to motor weight — the power-to-weight ratio — thereby contributing to vehicle weight reduction. "This requires, on the one hand, integrating new materials into the motors, and on the other hand, achieving simplified manufacturing for the motor components," explains Manuel Peter from the Institute of Production Science (wbk) at KIT. To address these challenges, the collaborative project ProLeMo relies on a comprehensive and interdisciplinary approach involving partners from industry and academia. The goal is to increase the power-to-weight ratio of electric motors while simultaneously simplifying manufacturing processes.

The wbk investigates solutions for the use of fiber-reinforced plastics in electric motors within ProLeMo. Over the next three years, the researchers will develop the necessary process chain to produce a demonstrator. This will enable the manufacturing of the considered motor components — rotor, stator, and housing with integrated cooling. The Institute of Vehicle System Technology (FAST) develops the components from fiber-reinforced composites and ensures, through the use of modern simulation tools, that they meet the requirements.

The involved partners cover all the necessary competencies for this project. The consortium coordinator is Witten-Stein cyber motor GmbH, which specializes in the development and manufacturing of high-performance, permanent magnet synchronous motors. In the area of injection molding technology, Arburg GmbH + Co KG is working on the use of alternative, moldable materials for motor components. For machining tasks and fiber placement, Index-Werke GmbH & Co. KG Hahn & Tessky is involved in the project, focusing on lathes and turning-milling centers. The process and machine development for manufacturing the required coils is handled by Aumann GmbH. Research support is provided by the Institute of Production Science (wbk) and the Institute of Vehicle System Technology (FAST) at KIT, for the three-year duration of the project.

The research project is funded with a total volume of 3.3 million euros, with 1.7 million euros provided by the Federal Ministry for Economic Affairs and Climate Action (BMWi). The project sponsor is the German Aerospace Center (DLR).