US4719378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brushless motor having permanent magnet rotor and salient pole stator
Assignee: Yaskawa Electric Corp
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Filing: 1986-08-21
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Granted: 1988-01-12
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Expires: 2006-08-21
Abstract
Abstract In a brushless motor, the number of magnetic poles P and the number of salient poles S are identified by: P=2×(m×k+l) S=2×m×k wherein m represents the number of phases and k represents an integer greater than 2. The windings wound about the k adjoining salient poles are made to belong to the same phase, but adjacent poles are oppositely wound.
Inventors
- 👤 Takashi Katsuma
- 👤 Masao Kitoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:00
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02K29/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
145 words
A brushless motor having a rotor magnet with a number of P of magnetic poles and a stator core facing the rotor magnet across an air gap, the stator core having a number S of salient poles about which stator windings are respectively wound for m phases, the rotor magnet being driven into rotation by detecting the rotary position of the rotor magnet relative to the stator core and by sequentially changing over phase currents passing through the stator windings, wherein said numbers P and S are defined as P=2×(m×k+1) S=2×m×k wherein k represents an integer greater than 2, and each said salient pole having said stator windings of only one phase and 2×m salient groups of k said salient poles, each said salient pole of each group having said stator windings of the same phase, the direction of winding varying for alternate salient poles.
Claim 2
Dependent Claim
145 words
A brushless motor having a rotor magnet with a number of P of magnetic poles and a stator core facing the rotor magnet across an air gap, the stator core having a number S of salient poles about which stator windings are respectively wound for m phases, the rotor magnet being driven into rotation by detecting the rotary position of the rotor magnet relative to the stator core and by sequentially changing over phase currents passing through the stator windings, wherein said numbers P and S are defined as P=2×(m×k+1) S=2×m×k wherein k represents an integer greater than 2, and each said salient pole having said stator windings of only one phase and 2×m salient groups of k said salient poles, each said salient pole of each group having said stator windings of the same phase, the direction of winding varying for alternate salient poles.
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) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |