Copper winding for electric drive 3D printed via binder jetting

Tennessee-based startup Maxxwell Motors has successfully partnered with ExOne on the development of a unique 3D printed copper winding design for its innovative axial flux electric motors. The e-winding part can be used in electric cars as well as a range of other heavy-duty vehicles and industrial devices.

ExOne and Maxxwell have successfully proved a new concept for binder jet 3D printing a high-efficiency copper e-winding design that eliminates many of the challenges that come with the traditional manufacturing of copper coils for electric motors. This new process eliminates the need for traditional coil wrapping, bending, tooling, and other inefficient process steps, also improving final part performance.

“In one of Maxxwell Motor’s patented electric motor designs, the copper coils for the stator winding fully surround the motors to conduct electricity and can be seen in the areas marked 132A and 132B. Approximately 36 coils are used in a standard motor design in each of those areas, but Maxxwell and ExOne aim to consolidate all the coils into a single 3D printed part, saving time and money.When we 3D print it, a lot of the challenges just go away, and we can actually improve the performance of the motor itself,” Paritee said. “At Maxxwell, we’re taking the most sustainable, and additive manufacturing, point of view as possible to truly improve efficiency, reduce waste and optimize performance.”

Founded in 2018 based on a vision of improving how electric motors are designed and manufactured, without rare-earth magnets, Maxxwell holds nine U.S and global patents and has launched two products, a 10 kW air-cooled motor-generator and a 150 kW liquid-cooled motor.

The company is led by the team of Chairman Gary Wells, the former CEO and current board member of Wells’ Dairy, maker of Blue Bunny and other ice cream brands, and CEO Michael Paritee, a former General Motors executive that managed several advanced vehicle programs and has guided technology firms for more than a decade.

Optimized copper windings and rotors in electric motors are among the factors enabling the automotive industry’s transition to hybrid and pure electric power vehicles. However, current methods of manufacturing the windings are costly, inefficient, and limit designs in a way that also limits their performance.

ExOne and Maxxwell have successfully proved out a new concept for binder jet 3D printing a high-efficiency design in copper that eliminates many of the challenges that come with traditional manufacturing. Additional development and testing are now underway.

Ultimately, Maxxwell’s goal is to binder jet 3D print winding assemblies as a monolithic piece, eliminating the need for coil wrapping, bending, tooling, and welding of individual parts together.

When produced with binder jet 3D printing, the final part would require less manufacturing steps and energy utilization, as well as less material waste to produce – also resulting in components that are more efficient and deliver improved performance. What’s more, high-speed binder jetting is relatively affordable.

“The ExOne team is proud to work with both traditional manufacturers and visionary startups working to change the world with innovative concepts such as these,” said John Hartner, ExOne’s CEO. “As the automotive industry enters a new era of electrification, our world-class team of engineers stands ready to help solve some of the most pressing challenges with our binder jet 3D printing technology.”