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Substantially Parallel Flux Uncluttered Rotor Machines (U-Machine)

Oak Ridge National Laboratory

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Projected performance/speed characteristics of the novel U-machine motor
Projected performance/speed characteristics of the novel U-machine motor

Technology Marketing SummaryA 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.DescriptionThe 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.Benefits
  • 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
Applications and Industries
  • Electric automotive propulsion
  • Industrial motors and generators
  • Auto manufacturers
  • Industrial motor/generator manufacturers
Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Patent 8,330,319
Substantially parallel flux uncluttered rotor machines
A permanent magnet-less and brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by polyphase alternating currents. An uncluttered rotor is positioned within the magnetic rotating field and is spaced apart from the stator. An excitation core is spaced apart from the stator and the uncluttered rotor and magnetically couples the uncluttered rotor. The brushless excitation source generates a magnet torque by inducing magnetic poles near an outer peripheral surface of the uncluttered rotor, and the stator currents also generate a reluctance torque by a reaction of the difference between the direct and quadrature magnetic paths of the uncluttered rotor. The system can be used either as a motor or a generator
Oak Ridge National Laboratory 12/11/2012
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
ORNL ID#2227Development - patent pendingAvailable01/22/201002/02/2010

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To: David Sims<>