Patent US5739614A successfully refreshed from Google Patents.
US5739614A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-phase unipolar driving brushless DC motor
Assignee: Minebea Co Ltd
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Filing: 1997-03-11
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Granted: 1998-04-14
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Expires: 2017-03-11
Abstract
Abstract A two-phase unipolar driving brushless DC motor of a radial gap type having a rotor position detector includes a main-pole yoke having main-poles, an interpole yoke coaxially provided with the main-pole yoke in a superposed manner and having interpoles and an axial short-circuit portion or member provided in an axially extending portion in magnetic fluxes formed in the main-poles and interpoles. This structure allows for easy winding of coils around the main-poles and enhanced winding space factor in order to increase the starting torque and to improve the motor efficiency.
Inventors
- 👤 Yuzuru Suzuki
- 👤 Sakae Fujitani
- 👤 Kenichi Makino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:23
CPC Classifications
H; H02; H02K; H02K21/00; H02K21/12; H02K21/22; H02K1/00; H02K1/06; H02K1/12; H02K1/14; H02K1/146; H02K29/00; H02K29/03
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
169 words
A two-phase unipolar driving brushless DC motor including: a stator assembly comprising a main-pole yoke having an axis and main-poles around which coils are wound and are arranged circumferentially of said main-pole yoke and an interpole yoke provided coaxially with said main-pole yoke in a superposed manner and having interpoles which are arranged circumferentially of said interpole yoke; a rotor assembly disposed coaxially with said main-pole yoke and said interpole yoke and provided with a rotor magnet having the same number of poles as said main-poles; magnetic flux circuits formed in said main-poles and said interpoles, for forming circulating magnetic fluxes in said main-poles and said interpoles; axial magnetic short-circuit means provided in a vicinity of and around said axis of said main-pole yoke and at and between said main-pole yoke and said interpole yoke, for guiding a part of said magnetic flux along said axis of said main-pole yoke; and a rotor position detector disposed at said rotor assembly and provided immovably with respect to said stator assembly.
Claim 2
Dependent Claim
169 words
A two-phase unipolar driving brushless DC motor including: a stator assembly comprising a main-pole yoke having an axis and main-poles around which coils are wound and are arranged circumferentially of said main-pole yoke and an interpole yoke provided coaxially with said main-pole yoke in a superposed manner and having interpoles which are arranged circumferentially of said interpole yoke; a rotor assembly disposed coaxially with said main-pole yoke and said interpole yoke and provided with a rotor magnet having the same number of poles as said main-poles; magnetic flux circuits formed in said main-poles and said interpoles, for forming circulating magnetic fluxes in said main-poles and said interpoles; axial magnetic short-circuit means provided in a vicinity of and around said axis of said main-pole yoke and at and between said main-pole yoke and said interpole yoke, for guiding a part of said magnetic flux along said axis of said main-pole yoke; and a rotor position detector disposed at said rotor assembly and provided immovably with respect to said stator assembly.
Claim 3
Dependent Claim
25 words
The motor according to claim 1, wherein said axial magnetic short-circuit means comprises axial magnetic short-circuit members extending along said axis of said main-pole yoke.
Claim 4
Dependent Claim
23 words
The motor according to claim 1, wherein said main-pole yoke and said interpole yoke have contact portions forming said axial magnetic short-circuit means.
Claim 5
Dependent Claim
21 words
The motor according to claim 1, wherein said interpole yoke having said interpoles comprises laminated plates made of a ferromagnetic material.
Claim 6
Dependent Claim
42 words
The motor according to claim 1, further comprising a motor driving circuit board made of a ferromagnetic material, and wherein said interpole yoke forms a part of said motor driving circuit board and said main-pole yoke is fixed to said interpole yoke.
Claim 7
Dependent Claim
15 words
The motor according to claim 5, wherein said interpole yoke includes said magnetic short-circuit means.
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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) | 2001-04-13 | 2001-10-13 | 2002-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-13 | 2005-10-13 | 2006-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-13 | 2009-10-13 | 2010-04-14 | $7700.00 | Window Closed / Lapsed |