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US 4,547,713 AGranted
Toroidally wound brushless DC motor
AssigneeKollmorgen Technologies Corporation
InventorsLawrence W. Langley, Robert L. Fisher
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Abstract
A high speed DC brushless motor in which the stator is toroidal and the stator core does not include winding slots. In the preferred embodiment the core material for the stator is an amorphous metal alloy which provides high speed motor efficiency. For some applications core materials like ferrite or low silicon-alloys can be used. According to one embodiment of the invention a ferrite shielding ring can be added surrounding the motor to further improve high speed efficiency.
Claims7
In a high speed electric motor, the combination of:
- a magnetic stator core,
- in the shape of ring without winding slots
- made from alloy magnetic material having flux density (B sat) above 0.3 Tesla, a resistivity above 40 uohm-cm, and a core loss below 0.30 watts/kg's;
- a rotor movable relative to said core, said rotor including at least one rare earth permanent magnet;
- a stator winding located in the air gap between said rotor and said stator core;
- a Hall device position detector for indicating the position of said permanent magnet;
- and
- means coupled to said position detector for energizing said winding to provide a rotating magnetic field.
5 more elements
Dependencies are inferred from the claim text.