WARF: P02287US

Dual-Rotor, Radial-Flux, Toroidally-Wound, Permanent Magnet Machine with High Efficiency and High Torque Density


Thomas Lipo, Ronghai Qu

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a dual-rotor, radial-flux, toroidally-wound, permanent magnet machine that simultaneously exhibits both high efficiency and high torque density.
OVERVIEWHigh torque density and high efficiency are two of the most desirable features of electrical machines. A significant amount of research over the past two decades has focused on improving these parameters. Several new motor topologies have been proposed to increase efficiency and torque density; however, these designs use rare earth magnets (i.e., neodymium-iron-boron magnets), which drive up the materials cost of these machines. In addition, some of these topologies are restricted to low speed applications.
THE INVENTIONUW-Madison researchers have developed a machine topology suitable for high speed applications that simultaneously exhibits high efficiency and high torque density. Their dual-rotor, radial-flux, toroidally-wound, permanent magnet machine also employs inexpensive ferrite magnets, making these machines inexpensive to produce.
  • Aeronautics
  • Wheel motors for hybrid vehicles
  • Generators
  • Provides both high torque density and high efficiency
  • Possesses high overload capacity
  • Low-cost
  • Suitable for moderate speed and high speed applications
Contact Information
For current licensing status, please contact Emily Bauer at or 608-960-9842.
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Since its founding in 1925 as the patenting and licensing organization for the University of Wisconsin-Madison, WARF has been working with business and industry to transform university research into products that benefit society. WARF intellectual property managers and licensing staff members are leaders in the field of university-based technology transfer. They are familiar with the intricacies of patenting, have worked with researchers in relevant disciplines, understand industries and markets, and have negotiated innovative licensing strategies to meet the individual needs of business clients.