Compact, high efficiency electric motor with less rare earths for hybrid electric vehicles

The United States Army is currently undergoing a shift to hybrid electric vehicles (HEVs), which it plans to complete by 2035, with the goal of harnessing key advantages critical for future warfare. These advantages include stealthier movement and silent reconnaissance watch, lower fuel consumption, lower maintenance and improved mobility in complex off road terrain enhancing overall lethality. Existing electric motors, a key component of HEV drivetrains, have limitations. Radial flux motors, the most used by electric vehicle (EV) manufacturers, tend to have lower motor efficiency, less torque, lower power density and a higher reliance on rare earth (RE) metals. Also, they are typically longer (nearly two thirds longer in axial length) and heavier (often >50% more weight). They also often require gearboxes because of their tendency to spin at speeds more than 20,000 rpm for high efficiency operation. These add to lower the fuel efficiency of radial flux motors, and ultimately, the range of the vehicle they are propelling. Leveraging the established advantages of axial flux motor technology, Torev Corp. has developed a proprietary stator architecture to produce a lightweight, compact 150kW double axial flux motor. The novel stator structure generates a high strength looped magnetic field with near zero leakage flux loss to maximize efficiency and torque density, while reducing the RE metal content. With this novel design, Torev’s motors will outperform existing radial flux and axial flux motor technologies. The stator coil structure also allows Torev to achieve direct drive, eliminating the need for a gearbox or driveshaft. Unlike existing complex axial flux motors, Torev’s innovative modular design lends itself to simplified manufacturing. To date, Torev has developed a 1kW prototype that has undergone third party testing and successfully demonstrated the electromagnetic principles of the stator structure and the high efficiency of its motor. The company is currently developing a family of higher power motors targeting HEV and BEV applications.