Patent US3732448A successfully refreshed from Google Patents.
US3732448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronous electric motor
Assignee: ELECTROMOTORENFAB DORDT NV
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Filing: 1971-04-06
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Granted: 1973-05-08
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Expires: 1991-04-06
Abstract
Abstract A polyphase synchronous A C motor having rectangular wave power input includes a stator having axially spaced core members, a D. C. winding between the core members and a polyphase winding extending through the core members. The rotor has two squirrel cage sections, one aligned within each core member and each squirrel cage section carries a pole piece. Each pole piece has a pair of diametrically opposed radially projecting poles and the poles of one pole piece are displaced 90* with respect to the poles of the other pole piece. The motor has a total of four circumferentially spaced poles and thus presents a pole pitch of 90* for each phase. The polyphase winding has at least one winding per phase. In one embodiment the poles have a circumferential width ( 90*) equal to the pole pitch and the polyphase windings have a like circumferential width. In another embodiment the poles have a circumferential width ( 60*) which is two-thirds of the pole pitch and, again, the polyphase windings have a like circumferential width.
Inventors
- 👤 L Schiethart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:56
CPC Classifications
H; H02; H02K; H02K19/00; H02K19/02; H02K19/10; H02K19/103; H02K19/14; H02K19/16; H02K19/18; H02K19/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
222 words
A synchronous A.C. motor comprising, in combination: a housing having at least a pair of axially spaced core members disposed therein; D.C. winding means disposed between said core members for establishing a closed D.C. magnetic field extending axially within said housing and passing radially through said core members; polyphase winding means extending through said core members and circumferentially of said housing for establishing a rotating magnetic field within said housing; a rotor journalled in said housing concentrically of said core members and said winding means, said rotor including a shaft, squirrel cage winding means fixed to said shaft and including circumferentially spaced electrically conducting rods and remote end plates disposed in planes substantially straddling said core members, and a pair of pole pieces within the confines of said squirrel cage winding means and each pole piece having a plurality of radially projecting and uniformly circumferentially spaced poles with the radially projecting poles of one pole piece being displaced circumferentially with respect to the poles of the other pole piece to lie in alignment with the spaces thereof; said polyphase winding means comprising a plurality of circumferentially spaced coils for each phase with each coil having a width in the peripheral direction around said rotor substantially equal to thE pole pitch and each pole having substantially the same peripheral width as the coils.
Claim 2
Dependent Claim
222 words
A synchronous A.C. motor comprising, in combination: a housing having at least a pair of axially spaced core members disposed therein; D.C. winding means disposed between said core members for establishing a closed D.C. magnetic field extending axially within said housing and passing radially through said core members; polyphase winding means extending through said core members and circumferentially of said housing for establishing a rotating magnetic field within said housing; a rotor journalled in said housing concentrically of said core members and said winding means, said rotor including a shaft, squirrel cage winding means fixed to said shaft and including circumferentially spaced electrically conducting rods and remote end plates disposed in planes substantially straddling said core members, and a pair of pole pieces within the confines of said squirrel cage winding means and each pole piece having a plurality of radially projecting and uniformly circumferentially spaced poles with the radially projecting poles of one pole piece being displaced circumferentially with respect to the poles of the other pole piece to lie in alignment with the spaces thereof; said polyphase winding means comprising a plurality of circumferentially spaced coils for each phase with each coil having a width in the peripheral direction around said rotor substantially equal to thE pole pitch and each pole having substantially the same peripheral width as the coils.
Claim 3
Dependent Claim
224 words
A synchronous A.C. motor comprising, in combination: a housing having at least a pair of axially spaced core members disposed therein; D.C. winding means disposed between said core members for establishing a closed D.C. magnetic field extending axially within said housing and passing radially through said core members; polyphase winding means extending through said core members and circumferentially of said housing for establishing a rotating magnetic field within said housing; a rotor journalled in said housing concentrically of said core members and said winding means, said rotor including a shaft, squirrel cage winding means fixed to said shaft and including circumferentially spaced electrically conducting rods and remote end plates disposed in planes substantially straddling said core members, and a pair of pole pieces within the confines of said squirrel cage winding means and each pole piece having a plurality of radially projecting and uniformly circumferentially spaced poles with the radially projecting poles of one pole piece being displaced circumferentially with respect to the poles of the other pole piece to lie in alignment with the spaces thereof; said polyphase winding means comprising a plurality of circumferentially spaced coils for each phase with each coil having a width in the peripheral direction around said rotor substantially equal to two-thirds of the pole pitch and each pole having substantially the same peripheral width as the coils.
Claim 4
Dependent Claim
224 words
A synchronous A.C. motor comprising, in combination: a housing having at least a pair of axially spaced core members disposed therein; D.C. winding means disposed between said core members for establishing a closed D.C. magnetic field extending axially within said housing and passing radially through said core members; polyphase winding means extending through said core members and circumferentially of said housing for establishing a rotating magnetic field within said housing; a rotor journalled in said housing concentrically of said core members and said winding means, said rotor including a shaft, squirrel cage winding means fixed to said shaft and including circumferentially spaced electrically conducting rods and remote end plates disposed in planes substantially straddling said core members, and a pair of pole pieces within the confines of said squirrel cage winding means and each pole piece having a plurality of radially projecting and uniformly circumferentially spaced poles with the radially projecting poles of one pole piece being displaced circumferentially with respect to the poles of the other pole piece to lie in alignment with the spaces thereof; said polyphase winding means comprising a plurality of circumferentially spaced coils for each phase with each coil having a width in the peripheral direction around said rotor substantially equal to two-thirds of the pole pitch and each pole having substantially the same peripheral width as the coils.
Claim 5
Dependent Claim
14 words
A synchronous motor as defined in claim 1 wherein said pole pitch is 90*.
Claim 6
Dependent Claim
15 words
A synchronous motor as defined in claim 2 wherein said pole pitch is 90* .
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) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |