Patent US5488260A successfully refreshed from Google Patents.
US5488260A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Encapsulated magnets in a permanent magnet rotor
Assignee: Johnson Electric SA
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Filing: 1993-10-15
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Granted: 1996-01-30
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Expires: 2013-10-15
Abstract
Abstract In a permanent magnet rotor, the circumferential gaps between circumferentially spaced sintered or cast magnets are filled by a plastic or resin material which also coats the outer circumferential surface of the magnets to secure the magnets to the rotor base. The plastic or resin material has a filler of particulate permanent magnet material to thereby provide a more gradual circumferential variation in magnetic flux between circumferentially adjacent magnets.
Inventors
- 👤 Marc A. Heyraud
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:52
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/272; H02K1/274; H02K1/2753; H02K1/278; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/49012
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
72 words
A permanent magnet rotor for an electric motor, the rotor comprising: a cylindrical rotor base; a plurality of permanent magnets located circumferentially around said rotor base with a respective circumferential gap located between adjacent permanent magnets; a binder located in each of said gaps and having a magnetic material dispersed therein, said magnetic material in each said circumferential gap being magnetized with a radial magnetic flux which varies circumferentially across said gap.
Claim 2
Dependent Claim
72 words
A permanent magnet rotor for an electric motor, the rotor comprising: a cylindrical rotor base; a plurality of permanent magnets located circumferentially around said rotor base with a respective circumferential gap located between adjacent permanent magnets; a binder located in each of said gaps and having a magnetic material dispersed therein, said magnetic material in each said circumferential gap being magnetized with a radial magnetic flux which varies circumferentially across said gap.
Claim 3
Dependent Claim
15 words
The permanent magnet of claim 1, wherein said binder is formed of a resin material.
Claim 4
Dependent Claim
23 words
The permanent magnet of claim 1, wherein said binder also coats an outer circumferential surface of each of said plurality of permanent magnets.
Claim 5
Dependent Claim
38 words
The permanent magnet rotor of claim 1, wherein said radial magnetic flux is greatest in the area adjacent the permanent magnets and is the lowest in the area of said gaps which is located in between adjacent magnets.
Claim 6
Dependent Claim
27 words
The permanent magnet of claim 1, wherein the radial flux around said rotor only falls to zero along radial planes passing through the gaps between adjacent magnets.
Claim 7
Dependent Claim
15 words
The permanent magnet of claim 5, wherein said binder is formed of a resin material.
Claim 8
Dependent Claim
15 words
The permanent magnet of claim 4, wherein said binder is formed of a resin material.
Claim 9
Independent Claim
107 words
A method for forming a permanent magnet rotor for an electric motor, the method comprising the steps of: obtaining a cylindrical base having a plurality of blocks of permanent magnetic material located circumferentially around said rotor base with a respective circumferential gap located between adjacent blocks of permanent magnetic material, a binder being located in each of said gaps and having a magnetic material dispersed therein; and simultaneously magnetizing said blocks of permanent magnetic materials and said magnetic material dispersed in each said circumferential gap, said magnetic material dispersed in each said circumferential gap being magnetized with a radial magnetic flux which varies circumferentially across said gap.
Claim 10
Independent Claim
107 words
A method for forming a permanent magnet rotor for an electric motor, the method comprising the steps of: obtaining a cylindrical base having a plurality of blocks of permanent magnetic material located circumferentially around said rotor base with a respective circumferential gap located between adjacent blocks of permanent magnetic material, a binder being located in each of said gaps and having a magnetic material dispersed therein; and simultaneously magnetizing said blocks of permanent magnetic materials and said magnetic material dispersed in each said circumferential gap, said magnetic material dispersed in each said circumferential gap being magnetized with a radial magnetic flux which varies circumferentially across said gap.
Claim 11
Dependent Claim
14 words
The method of claim 8, wherein said binder is formed of a resin material.
Claim 12
Dependent Claim
22 words
The method of claim 8, wherein said binder coats an outer circumferential surface of each of the blocks of permanent magnetic material.
Claim 13
Dependent Claim
38 words
The method of claim 8, wherein said magnetizing step causes the radial magnetic flux in the area adjacent the permanent magnets to be greatest and the radial magnetic flux in the area between adjacent magnets to be lowest.
Claim 14
Dependent Claim
54 words
The method of claim 8, where said magnetizing step causes the radial magnetic flux between first and second of said permanent magnets to vary from a maximum level adjacent said first permanent magnet, through zero halfway between the first and second permanent magnets and back to a maximum level adjacent said second permanent magnet.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-29 | 1999-07-31 | 2000-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-29 | 2003-07-31 | 2004-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-29 | 2007-07-31 | 2008-01-30 | $7700.00 | Window Closed / Lapsed |