US5030864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-phase electrical machine with reduced cogging torque
Assignee: US Philips Corp
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Filing: 1989-09-06
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Granted: 1991-07-09
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Expires: 2009-09-06
Abstract
Abstract An electrical multipole machine comprises a first machine section (1), a second machine section (3) and a machine shaft (5), about which one machine section is rotatable relative to the other machine section. The first machine section comprises an annular permanent-magnet body (11) having a plurality of adjacent pole pairs (N; S). The second machine section comprises a lamination assembly (25) having teeth (27-35) and coils (37-45). The teeth comprise tooth surfaces (47-55) which are geometrically spaced from one another by slots (57-65) and from the magnet body by an air gap (67). Near the air gap the slots extend in a tangential direction over at least 80 electrical degrees and at the most 90 electrical degrees, or over at least 130 electrical degrees and at the most 150 electrical degrees. The ratio between the number of poles and the number of teeth is either 4:3 or 2:3.
Inventors
- 👤 Henricus M. van Hout
- 👤 Jan Janson
- 👤 Johannes H. H. Janssen
- 👤 Robertus I. Van Steen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:04
CPC Classifications
H; H02; H02K; H02K23/00; H02K21/00; H02K21/12; H02K21/22; H02K21/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
131 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, slots formed in said body to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the tooth surfaces having equal tangential dimensions, each of the slots extending over at least 80 electrical degrees and at the most 90 electrical degrees in a tangential direction, and the number of poles and the number of teeth being in a ratio of 4:3 to each other; and a machine shaft about which one machine section is rotatable relative to the other machine section.
Claim 2
Dependent Claim
131 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, slots formed in said body to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the tooth surfaces having equal tangential dimensions, each of the slots extending over at least 80 electrical degrees and at the most 90 electrical degrees in a tangential direction, and the number of poles and the number of teeth being in a ratio of 4:3 to each other; and a machine shaft about which one machine section is rotatable relative to the other machine section.
Claim 3
Dependent Claim
131 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, slots formed in said body to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the tooth surfaces having equal tangential dimensions, each of the slots extending over at least 130 electrical degrees and at the most 150 electrical degrees in a tangential direction, and the number of poles and the number of teeth being in a ratio of 4:3 to each other; and a machine shaft about which one machine section is rotatable relative to the other machine section.
Claim 4
Dependent Claim
131 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, slots formed in said body to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the tooth surfaces having equal tangential dimensions, each of the slots extending over at least 130 electrical degrees and at the most 150 electrical degrees in a tangential direction, and the number of poles and the number of teeth being in a ratio of 4:3 to each other; and a machine shaft about which one machine section is rotatable relative to the other machine section.
Claim 5
Dependent Claim
131 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, in which body slots extending over at least 80 electrical degrees and at the most 90 electrical degrees in a tangential direction near an air gap are formed to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the tooth surfaces having equal tangential dimensions, and the number of poles and the number of teeth being in a ratio of 2:3 to each other; and a machine shaft about which one machine section is rotatable relative to the other section.
Claim 6
Dependent Claim
131 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, in which body slots extending over at least 80 electrical degrees and at the most 90 electrical degrees in a tangential direction near an air gap are formed to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the tooth surfaces having equal tangential dimensions, and the number of poles and the number of teeth being in a ratio of 2:3 to each other; and a machine shaft about which one machine section is rotatable relative to the other section.
Claim 7
Dependent Claim
133 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, slots formed in said body to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the number of poles and the number of teeth is in a ratio of 2:3 to each other, the tooth surfaces having equal tangential dimensions, and the slots near the air gap extending over at least 130 electrical degrees and at the most 150 electrical degrees in a tangential direction, and a machine shaft about which one machine section is rotatable relative to the other machine section.
Claim 8
Dependent Claim
133 words
A three-phase electrical machine, comprising: a first machine section comprising an annular permanent-magnet body having a plurality of adjacent pole pairs, each comprising a north pole and a south pole; a second machine section comprising a soft-magnetic body and at least one coil, slots formed in said body to define teeth, which each have a tooth surface for cooperation with said poles via an air gap, the number of poles and the number of teeth is in a ratio of 2:3 to each other, the tooth surfaces having equal tangential dimensions, and the slots near the air gap extending over at least 130 electrical degrees and at the most 150 electrical degrees in a tangential direction, and a machine shaft about which one machine section is rotatable relative to the other machine section.
Claim 9
Dependent Claim
37 words
An electrical machine as claimed in claim 1 or 3, characterized in that near the air gap the slots extend over at least 86 electrical degrees and at the most 90 electrical degrees in a tangential direction.
Claim 10
Dependent Claim
37 words
An electrical machine as claimed in claim 2, or 4 characterized in that near the air gap the slots extend over at least 143 electrical degrees and at the most 147 electrical degrees in a tangential direction.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |