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US 4,605,874 AGranted
Brushless D.C. dynamoelectric machine having ferrite material magnetic circuit
AssigneeMaghemite Inc.
InventorEric Whiteley
Life of this patent
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Abstract
A dynamoelectric machine which may operate in a motor mode or a generator mode is described wherein substantially the entire magnetic circuit is provided by ferrite material. In one particular embodiment, hard ferrite permanent magnet segments are mounted on a rotor plate while soft ferrite magnet segments with electrical coil windings mounted thereon are provided in a stator spaced apart from the rotor by an air gap. Other embodiments of the concept are described.
Claims6
A brushless D.C. dynamoelectric machine, which comprises:
- a disc-like rotor element comprising hard ferrite toroid means providing a plurality of magnetic poles of alternating polarity and mounted for rotation about its axis,
- a disc-like stator element comprising soft ferrite toroid means and mounted coaxially with and spaced apart from the rotor element, said soft ferrite toroid means being formed with radially-directed coil winding-receiving slots, and
- electrical coil windings mounted to said stator in said slots and each spanning one rotor pole pitch.
A brushless D.C. dynamoelectric machine, which comprises:
- a disc-like stator element,
- a disc-like rotor element mounted coaxially with and spaced apart from the stator element for rotation about its axis,
- permanent magnet hard ferrite toroid means mounted on said rotor element to provide a plurality of magnetic poles of alternating polarity,
- high permeability soft ferrite toroid means mounted on said stator element, said soft ferrite toroid means being formed as a continuous toroid having a radially-sloping surface defining a narrower thickness at the inner periphery than at the outer periphery, and
- electrical coil windings provided in association with said soft ferrite toroid means by being arranged on the surface of the toroid with the same conductor length subtended at the toroid inner diameter as at the outer diameter.
2 more elements
Dependencies are inferred from the claim text.