US3654503A
Expired / Lapsed
US
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Synchronous motors with field starting resistor arrangement
Assignee: Westinghouse Electric Corp
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Filing: 1970-09-24
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Granted: 1972-04-04
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Expires: 1990-09-24
Abstract
Abstract A synchronous motor is provided with starting resistors connected on each field coil or between pairs of field coils so as to confine the induced field current to only the portion of the field coils nearest the air gap. This results in less flux leakage and increases the contribution to pull-in torque of the field coils near synchronous speed so the machine can be brought into synchronism with a higher load torque than otherwise.
Inventors
- 👤 Eugene C Whitney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:41
CPC Classifications
H; H02; H02K; H02K19/00; H02K19/02; H02K19/10; H02K19/12; H02K19/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A synchronous dynamoelectric machine comprising: inductively related machine elements including a stator and a rotor; a first of said machine elements having an armature winding thereon; a second of said machine elements having a plurality of field poles thereon each having a face toward said first machine element, a damper winding on each of said poles on said face and a field coil around each of said poles, said field coils being mutually interconnected and each comprising a plurality of radially stacked turns; and resistive means connected with said field coils to limit the number of said turns in which induced field current flows when said machine is started.
Claim 2
Dependent Claim
109 words
A synchronous dynamoelectric machine comprising: inductively related machine elements including a stator and a rotor; a first of said machine elements having an armature winding thereon; a second of said machine elements having a plurality of field poles thereon each having a face toward said first machine element, a damper winding on each of said poles on said face and a field coil around each of said poles, said field coils being mutually interconnected and each comprising a plurality of radially stacked turns; and resistive means connected with said field coils to limit the number of said turns in which induced field current flows when said machine is started.
Claim 3
Dependent Claim
26 words
The subject matter of claim 1 wherein: said resistive means comprises a plurality of resistor elements each connected between an adjacent pair of said field coils.
Claim 4
Dependent Claim
28 words
The subject matter of claim 1 wherein: said resistive means comprises, on each of said field coils, a single resistor element connected across a number of turns thereof.
Claim 5
Dependent Claim
46 words
The subject matter of claim 2 wheRein said resistor elements are connected to said filled coils for increasing motor starting torque by limiting said turns in which induced field current flows when said machine is started to a number of turns nearest said first machine element.
Claim 6
Dependent Claim
47 words
The subject matter of claim 2 wherein: said resistor elements are connected to said field coils for decreasing motor starting torque by limiting said turns in which induced field current flows when said machine is started to a number of turns farthest from said first machine element.
Claim 7
Dependent Claim
63 words
The subject matter of claim 4 wherein: said first machine element is said stator, said second machine element is said rotor and is positioned within said stator; said field coils are serially interconnected; and said resistor elements are individually connected between an adjacent pair of said field coils that are mutually interconnected between their respective turns that are nearest said other machine element.
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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |