The wheel hub motor on the Frecc0 demo vehicle. (Fraunhofer IFAM)

Fraunhofer researchers are engineering wheel hub motors, which are integrated into a car's wheels, and could become the accepted drive concept for electric vehicles. The scientists are testing these and several other components on the "Frecc0," their demonstration vehicle.

Working jointly in a multidisciplinary cooperation of 33 Fraunhofer institutes, they are paving the way for future technologies in all areas of electromobility.

One advantage of wheel hub motors is that manufacturers can dispense with the conventional engine bay - the space under the hood or bonnet - since the motors are attached directly to the wheels of the vehicle. This opens up opportunities for car designers when drafting the layout of the vehicle.

By dispensing with the transmission and differential, the mechanical transmission elements suffer no losses or wear and tear. Moreover, the direct drive on each individual wheel may improve the drive dynamic and drive safety.

The researchers are developing not only individual components, but the total system as well. They assemble the components on their concept car, the Frecc0 (Fraunhofer E-Concept Car Type 0). Starting next year, automobile manufacturers and suppliers will also be able to use the Frecc0 for testing new components. The basis of this demo model is an existing car - the new Artega GT manufactured by Artega Automobil GmbH. The establishment of this platform and the engineering of the wheel hub motor are run by Fraunhofer System Research for Electromobility.

"We are developing a wheel hub motor that integrates all essential electric and electronic components, especially the power electronics and electronic control systems, into the installation space of the motor. Thus, no external electronics are necessary and the number and scope of the feed lines can be minimized. There is a marked increase in power compared to the wheel hub motors currently available on the market. Moreover, there is an innovative security and redundancy concept, which guarantees drive safety – even if the system breaks down," explains Professor Matthias Busse, head of the Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research IFAM.

In contrast to conventional vehicles, electric cars can recapture the energy that comes from braking, and feed it back into the battery. The researchers are working on maximizing this energy recapture in the future. The conventional braking system still in use will only be needed in emergency situations.