23 Jul 2024


‘Breakthrough’ motor combines strengths of different technologies

Mahle says that its efficient magnet-free motor with offer environmental and cost advantages

The German automotive powertrain supplier Mahle is developing a magnet-free motor that, it claims, will operate with an efficiency of more than 95% at almost all operating points. The motor uses an inductive – and thus contact-, wear- and maintenance-free – technology to transmit power between the motor’s stationary and rotating parts.

Mahle says that the asynchronous motor, which generates magnetic fields using excitation coils in the rotor, combines the strengths of different motor technologies in one product. It does not use any rare-earth materials, making it environmentally attractive, and offering advantages in terms of costs and resource security.

“Our magnet-free motor can certainly be described as a breakthrough, because it provides several advantages that have not yet been combined in a product of this type,” explains Dr Martin Berger, vice-president of corporate research and advanced engineering at Mahle. “As a result, we can offer our customers a product with outstanding efficiency at a comparatively low cost.”

Energy is transmitted to the rotor via an alternating field. The energy is converted into DC to power the magnetic coils, avoiding the need for permanent magnets. The coils induce a magnetic field in the motor’s airgap, causing it to produce torque. Depending on the operating point, the field can be controlled easily – unlike PM machines, according to Mahle.

The rugged motor technology is aimed principally at automotive drivetrains and is said to be scalable, allowing it to be used in anything from small passenger cars to large commercial vehicles. It is expected to be a few years before the technology is available commercially.

“With our new electric motor, we’re living up to our responsibility as a sustainably operating company,” says Mahle’s chairman and chief financial officer, Michael Frick. “Dispensing with magnets and therefore the use of rare-earth elements offers great potential not only from a geopolitical perspective, but also with regard to the responsible use of nature and resources.”