US3679925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical apparatus with corona suppression means
Assignee: Westinghouse Electric Corp
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Filing: 1971-02-02
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Granted: 1972-07-25
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Expires: 1991-02-02
Abstract
Abstract In electrical apparatus in which high voltages may occur between two closely spaced conductive members, at least one of which is insulated by a coating of insulation, and in which the electric field gradient parallel to the surface of this insulated conductor in some area is sufficient to cause surface corona, an additional member of electrical insulation is introduced to this area to form a new insulation surface with a lower field gradient, thus suppressing surface corona. To suppress end corona between the end portion of a stator coil and the stator core of a dynamoelectric machine, a collar encircling the coil at the face of the core is provided in accordance with this invention. The invention facilitates the production of high voltage machines in which the coils are insulated by post impregnation (i.e., after winding on the core).
Inventors
- 👤 Emil M Fort
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:03
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/32; H02K3/40
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
130 words
A high voltage dynamoelectric machine comprising: a stator including a magnetic core with at least one slot extending therethrough, a coil of an electrical conductor wound around said core with a portion disposed within said slot and an end portion extending into a gaseous medium beyond an end face of said core, said coil comprising at least one conductive turn embedded in a mass of insulation by impregnation after said turns are wound on said core, a corona suppressing insulation collar around said coil and in contact with the insulation on said coil and that on said end face, said collar completely encircling said end portion of said coil and occupying a volume through which the shortest paths between said end face and said end portion of said coil occur.
Claim 2
Dependent Claim
130 words
A high voltage dynamoelectric machine comprising: a stator including a magnetic core with at least one slot extending therethrough, a coil of an electrical conductor wound around said core with a portion disposed within said slot and an end portion extending into a gaseous medium beyond an end face of said core, said coil comprising at least one conductive turn embedded in a mass of insulation by impregnation after said turns are wound on said core, a corona suppressing insulation collar around said coil and in contact with the insulation on said coil and that on said end face, said collar completely encircling said end portion of said coil and occupying a volume through which the shortest paths between said end face and said end portion of said coil occur.
Claim 3
Dependent Claim
36 words
The subject matter of claim 1 wherein: said collar is of an absorbent insulating matrix impregnated with a resinous insulating material that also comprises a component of the insulation in which said conductive turn is embedded.
Claim 4
Dependent Claim
28 words
The subject matter of claim 1 wherein: said magnetic core of said stator and said coil are operated with a voltage difference therebetween of at least 10,000 volts.
Claim 5
Independent Claim
96 words
A method of making electrical apparatus capable of operation at high voltages with low probability of corona, comprising the steps of: assembling electrically conductive members of the apparatus to be operated at substantially different voltages; placing a continuous member of an insulating material in corners between said conductive members that otherwise would be occupied by the gaseous ambient in which the apparatus operates; impregnating the assembled conductive members with an insulation medium to provide solid insulation between said conductors and to securely bond said member of insulating material to said conductive members without a gap therebetween.
Claim 6
Independent Claim
96 words
A method of making electrical apparatus capable of operation at high voltages with low probability of corona, comprising the steps of: assembling electrically conductive members of the apparatus to be operated at substantially different voltages; placing a continuous member of an insulating material in corners between said conductive members that otherwise would be occupied by the gaseous ambient in which the apparatus operates; impregnating the assembled conductive members with an insulation medium to provide solid insulation between said conductors and to securely bond said member of insulating material to said conductive members without a gap therebetween.
Claim 7
Dependent Claim
20 words
The subject matter of claim 4 wherein: said member of insulating material is a preformed solid member of insulating material.
Claim 8
Dependent Claim
15 words
The subject matter of claim 4 wherein: said member is of an absorbent insulating matrix.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |