Additively manufactured air-cooled lightweight rotor for an automotive electric motor

Additive manufacturing of rotors for electrical machines offers great potential in terms of cooling and lightweight construction due to the various design possibilities offered by this method. This paper explains how additive manufacturing can be used to design an electrical machine rotor for an automotive application. To take advantage of the benefits of additive manufacturing, various modifications, such as an air-cooling system and lightweight structures, were included in the rotor. The disadvantages of additive manufacturing, such as comparatively large minimum manufacturing widths of the edge bridges and easier formation of eddy currents, were addressed through limiting modifications. The completed design was built and tested on a motor test bench. The results showed that such a machine can be feasibly manufactured and can provide comparable or even better performance than a conventionally manufactured motor.