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U.S. Department of Energy
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Axial gap permanent-magnet machine with reluctance poles and PM element covers

Patent ·
OSTI ID:986533

An electric machine (10) has a disk-shaped rotor (24) disposed in an operating space between two opposing stator assemblies (11, 12) to provide two axial air gaps (15, 16). The rotor (24) has a hub (28) and an outer ring (26) of non-magnetic material and is further provided with a plurality of permanent magnetic elements (25) for coupling flux that is induced by the magnetic field of the stator assemblies (11, 12). The permanent magnetic elements (25) are spaced apart and reluctance poles (27) are positioned in spaces between the magnetic elements (25) to couple additional flux induced by the magnetic field of the stator assemblies (11, 12). Various constructions and shapes (40-45) for the PM magnetic elements (25) are disclosed, and including PM covers (60) of ferromagnetic material for enhancing q-axis flux in the air gaps (15, 16) and for reducing harmonics where toothed stators are used. Methods of providing increased torque using the the various rotor constructions are also disclosed.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-00OR22725
Assignee:
UT-Battelle LLC (Oak Ridge, TN)
Patent Number(s):
7,514,833
Application Number:
11/228,698
OSTI ID:
986533
Country of Publication:
United States
Language:
English