Composite-type electromagnet and radial magnetic bearing
First Claim
1. A composite-type electromagnet comprising:
- an electromagnet having a controlling coil wound around an electromagnet core formed of a magnetic material;
a biasing permanent magnet in contact with the electromagnet core so that only a minute gap exists at a junction between the electromagnet core and the permanent magnet; and
a filling material having a high permeability and a high saturation magnetic flux density disposed in the minute gap.
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Accused Products
Abstract
A composite-type electromagnet for a radial magnetic bearing has four composite-type electromagnet parts. Each part has four electromagnet cores formed of a magnetic material. The cores each have two protruding poles. A control coil is wound around each of the protruding poles and a biasing permanent magnet is disposed between each of the cores. The electromagnet cores and the biasing permanent magnets are in direct contact such that only a minute gap exists at a junction therebetween. A viscous material, adhesive material, or a magnetic fluid such as grease, having therein a material having high permeability and high saturation magnetic flux density is disposed in the minute gap so as to minimize magnetic flux leakage at the junction.
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Citations
13 Claims
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1. A composite-type electromagnet comprising:
- an electromagnet having a controlling coil wound around an electromagnet core formed of a magnetic material;
a biasing permanent magnet in contact with the electromagnet core so that only a minute gap exists at a junction between the electromagnet core and the permanent magnet; and
a filling material having a high permeability and a high saturation magnetic flux density disposed in the minute gap. - View Dependent Claims (2, 6, 7)
- an electromagnet having a controlling coil wound around an electromagnet core formed of a magnetic material;
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3. A radial magnetic bearing comprising:
- a controlling electromagnet having a controlling coil wound around an electromagnet core formed of a magnetic material;
a biasing permanent magnet in contact with the electromagnet core so that only a minute gap exists at a junction between the electromagnet core and the permanent magnet; and
a filling material having a high permeability and a high saturation magnetic flux density disposed in the minute gap. - View Dependent Claims (5)
- a controlling electromagnet having a controlling coil wound around an electromagnet core formed of a magnetic material;
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4. A radial magnetic bearing for supporting a shaft, comprising:
- an annular member formed by alternately arranging around the shaft four electromagnet cores each having two protruding poles and four biasing permanent magnets;
an electromagnet formed of eight controlling coils wound around the protruding poles to form four composite-type electromagnet parts consisting of a +Y-axis composite-type electromagnet part, a −
Y-axis composite-type electromagnet part, a +X-axis composite-type electromagnet part and a −
X-axis composite-type electromagnet part, each composite-type electromagnet part being formed by the combination of a respective biasing permanent magnet, two opposite protruding poles adjacent each of the biasing permanent magnets, and two controlling coils wound around the protruding poles; and
a filling material having a high permeability and a high saturation magnetic flux density disposed in a minute gap existing in a junction between each electromagnet core and biasing permanent magnet.
- an annular member formed by alternately arranging around the shaft four electromagnet cores each having two protruding poles and four biasing permanent magnets;
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8. A radial magnetic bearing for rotatably supporting a cylindrical shaft, comprising:
- a plurality of electromagnets each comprised of a core formed of a magnetic material and a coil wound around the core, the electromagnets being arranged annularly to surround the cylindrical shaft;
a plurality of biasing permanent magnets disposed between adjacent ones of the electromagnets so each biasing permanent magnet abuts two of the cores and two of the biasing permanent magnets abut each core, each of the biasing permanent magnets being in direct contact with the two cores adjacent opposite ends thereof such that only a minute gap exists at a junction between each core and the adjacent permanent magnets; and
a material having a high permeability and a high saturation magnetic flux density disposed in the minute gap. - View Dependent Claims (9)
- a plurality of electromagnets each comprised of a core formed of a magnetic material and a coil wound around the core, the electromagnets being arranged annularly to surround the cylindrical shaft;
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10. A rotary device comprising:
- a housing;
a cylindrical shaft disposed in the housing; and
at least one magnetic bearing for supporting the shaft in the housing without coming into contact with the shaft, the at least one magnetic bearing comprising a plurality of electromagnets arranged annularly about the cylindrical shaft, and a permanent magnet disposed between adjacent electromagnet cores, each permanent magnet being in direct contact with two adjacent electromagnets disposed on opposite sides thereto so that only a minute gap exists between each permanent magnet and the two adjacent electromagnets, and a material having a high permeability and a high saturation magnetic flux density disposed in the minute gap. - View Dependent Claims (11, 12, 13)
- a housing;
Specification