Mercedes-Benz demonstrates EV motor with axial flux in concept car One-Eleven

CARLSBAD, CALIF. – In 1969, a few months after humans first walked on the surface of the moon, Mercedes-Benz debuted a revolutionary new concept car at that year’s Frankfurt auto show. Called the C111, this orange-and-black coupé featured dramatic gull-wing doors, but also served as a test bed for new technology, including a four-rotor Wankel rotary engine. Now, 54 years later, it has drawn inspiration from that car for its latest concept, the Vision One-Eleven. It is also orange and also shows new technology, in this case very small and lightweight axial flux electric motors.

Axial flux motors aren’t exactly new – most optical drives use them, for example, but they aren’t very common in automotive applications. The one-off Jeep Magneto used axial-flux engines, as did hybrid supercars from Acura, McLaren, and Ferrari. In the case of the Italian OEM, it sources the engines from Yasa, a British company acquired by Mercedes in 2021.

Like the much more common radial flux motor, an axial flux motor uses magnets (permanent magnets in this case), soft iron to transport the flux, copper as the material connected to the drive, and an aluminum housing.

“But that’s where the similarity ends,” says Tim Woolmer, who founded Yasa in 2009 to commercialize his PhD research. “So in a radial flux machine, the flux travels from the permanent magnets to the stator, around the stator yoke and then falls back into the rotor forming a loop. So the flux in the air gap moves radially, hence the name “radial flux machine,” explained he out.

“On the axial flux machine with two sheaves and one stator, the flux in this case actually travels from rotor to rotor right through the stator, then goes around the back steel in the rotor and then back through the stator through another coil,” Wolmer said.