US4283647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Annular segment permanent magnet single air gap electric motor
Assignee: Singer Co
•
Filing: 1979-08-30
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Granted: 1981-08-11
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Expires: 1999-08-30
Abstract
Abstract A single air gap permanent magnet electric motor is provided with field magnets formed as thick annular segments concentric with the axis of rotation of a solid non-magnetic cylindrical armature. The field magnets are magnetized radially to the axis and have oppositely polarized pole faces facing the axis. The ratio of the thickness to the inner diameter of the annular segments is maintained within a defined range to provide for a high magnetic flux density across the single air gap.
Inventors
- 👤 John A. Herr
- 👤 Wolfgang Jaffe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:27
CPC Classifications
H; H02; H02K; H02K23/00; H02K23/02; H02K23/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
In an electric motor having a solid non-magnetic cylindrical armature with commutated windings thereon, and means rotationally mounting said armature about the cylindrical axis thereof radially within a single air gap formed by peripheral permanent magnets having oppositely polarized pole faces facing the axis of said armature, the improvement wherein said permanent magnets are formed as substantially equal size annular segments concentric with said axis and magnetized radially to said axis, each of said annular segments having an inner diameter D and a thickness T obeying the relationship 0.7D<T<1.3D.
Claim 2
Dependent Claim
89 words
In an electric motor having a solid non-magnetic cylindrical armature with commutated windings thereon, and means rotationally mounting said armature about the cylindrical axis thereof radially within a single air gap formed by peripheral permanent magnets having oppositely polarized pole faces facing the axis of said armature, the improvement wherein said permanent magnets are formed as substantially equal size annular segments concentric with said axis and magnetized radially to said axis, each of said annular segments having an inner diameter D and a thickness T obeying the relationship 0.7D<T<1.3D.
Claim 3
Dependent Claim
22 words
The improvement according to claim 1 wherein the edges of said permanent magnets are substantially radially oriented with respect to said axis.
Claim 4
Dependent Claim
17 words
The improvement according to claim 1 wherein said permanent magnets are made from high energy ceramic magnets.
Claim 5
Dependent Claim
20 words
The improvement according to claim 1 wherein each of said annular segments extends over an arc length of approximately 145°.
References Cited (Backward Citations)
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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) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |