Substantially Parallel Flux Uncluttered Rotor Machines (U-Machine)

Stage: Development
A general concern based on the supply and demand trend of the permanent magnet (PM) raw materials suggests the need for elimination of these materials from electric motors (and generators) to control future costs. This invention discloses a new motor topology that eliminates the PM. Other innovations include brushless adjustable field excitation for high starting torque, field weakening, and power factor improvement and novel locks for higher peak speed. This novel machine shows promising potential to meet the DOE's FY-2020 motor targets for vehicle applications.

The motor consists of a stator punching core with multi-phase stator windings. The rotor is made of a unique lamination core which reduces the surface loss on the rotor. Grooves between poles are used for the insertion of locks or their equivalents that use the vacant space of the grooves for latching purpose. The rotor punching core is assembled to the rotor hub with keys and key ways for torque transmission. Two parallel magnetic fluxes are produced by two toroidal coils located in the stationary excitation cores. At each end of the rotor punching core, an end piece that contacts every other pole transfers the flux from the stationary excitation core to the rotor.

Applications and Industries

  • Electric automotive propulsion
  • Industrial motors and generators
  • Auto manufacturers
  • Industrial motor/generator manufacturers


  • Peak motor speed can increase further from the existing drive motors for reductions in cost, weight, and volume of the motor
  • No permanent magnets in the motor for cost and temperature advantages
  • Mutual beneficial influences (such as the reduction of inverter loading from improved motor power factor) among the motor, power electronics, and cooling of the drive system
  • The advanced performance of the permanent magnet (PM) motors (such as strong starting torque) are not only retained but also enhanced