Additive Drives: 3D Printed Windings for Electric Cars

“We have taken a big step in the copper processing process.” – Jakob Jung

Additive Drives, recently founded and headquartered in Dresden, Germany, continues to improve “e-machines” in terms of performance. Now, with new 3D printed windings and coils, the Additive Drives engineering team has been able to realize greater efficiency for electric motors (and thus, electric cars) through intense “re-thinking” in design and engineering.

While conventional manufacturing yields typical round wire winding, when compared to 3D printed coils, the Additive Drives team found that as the new design played a vital role as the source of heat, dissipation was improved, solving a common—and previously limiting—issue.

Managing Director Jakob Jung explained in a recent interview that while an electric motor may appear to be basic, there are numerous parts at play on the inside, to include thermal mechanics, structural mechanics, and electromagnetics. Designs must be compact and even “elegantly” considered as there is little space to work with, leading to the re-think in engineering and placement of smaller pieces.

Jakob Jung is managing director of Additive Drives. (Image: Additive Drives)

As 3D printing transforms numerous industries today, new parts may be created or improved in ways never before possible with conventional technology. While the dental and medical realm has been enormously affected, as well as aerospace, construction, and so much more, the automotive industry has reaped countless benefits—and they just keep coming due to the ability to make parts that are more affordable, lighter in weight but stronger, and easily adjusted for nearly any design specifications.

Conventional windings tend to be limited and challenging to perfect as conductors, processes, and geometry must match. With novel procedures created by Additive Drives and a customized laser melting system, they are able to prevent voids and issues with improper fit for grooves. The amount of copper is increased when filling in grooves, resulting in less electrical resistance.

“The variable shape also favors heat dissipation, because every wire has thermal contact with the coil’s so-called laminated core, so there are no hotspots,” said Jung. “Overall, the engine’s output can be increased by up to 45 percent.”

Cross-section of a classic round wire winding: Each conductor lies in the space between the conductors below and above. The copper fill factor is about 45 percent. (Image: Additive Drives)

Cross-section of 3D printed individual coils: Manufactured using the selective laser melting process, each turn can be adjusted so that the available slot area is used as effectively as possible. The copper fill factor is about 65 percent. (Image: Additive Drives)

The final winding, consisting of 3D printed coils. (Image: Additive Drives)

For the electric motor, overall, much of the improvements made in the 3D printing industry revolve around refinements for dealing with high temperatures. Production is also much faster for parts like windings, with turnaround times cut from as much as six months to as little as a few weeks.

Cross-section through the complete electric motor. (Image: Additive Drives)

Companies like Volkswagen have employed 3D printing in manufacturing electric cars, as well as luxury dealer Genesis, and organizations like Taiwan Automotive Research Consortium. Industry next-gen leaders like Keracel are also transforming batteries for electric cars, partnering with other manufacturers and 3D printing solid-state batteries. Additive manufacturing within this space allows leading companies to accelerate progress with electric cars.