Electric motors with housing made from polymer materials would be significantly lighter than the models currently available. However, it is not yet possible to construct such motors, since although state-of-the-art, fiber-reinforced polymer materials are on a par with metal housing in terms of stability, they are significantly worse at conducting heat. The scientists at the Fraunhofer Institute for Chemical Technology ICT and Karlsruhe Institute of Technology (KIT) want to resolve this problem with a directly-cooled electric motor with integrated lightweight housing (DEmiL).
An electric motor consists of a rotating rotor and a static stator. The stator contains the copper windings that the electricity flows through – and this is where the majority of electrical losses occur. The researchers now want to use rectangular flat wires here, which can be wound more tightly in the stator. This leaves more space for the cooling channel inside the stator; the metallic cooling sleeve used in electric motors up until now is no longer needed. According to the scientists, this not only results in a reduction in the overall weight, but also in lower thermal inertia and higher continuous output from the motor.