US3934332A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making electrical coils having improved strength and oil permeability
Assignee: Westinghouse Electric Corp
•
Filing: 1974-11-26
•
Granted: 1976-01-27
•
Expires: 1994-11-26
Abstract
Abstract A porous, electrical insulating adhesive substrate is made, by uniformly coating a flexible, porous sheet material with adhesive resin particles having an average particle size of between about 37 to 420 microns, the adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution, and then heating the coated sheet material between about 85 DEG to 250 DEG C, forming a discontinuous 0.25 to 7 mil dry coating of discrete adhesive particles having substantially rounded cross sections bonded to the sheet material, said adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution; the coated sheet may then be inserted as oil permeable layer insulation between high voltage windings and low voltage windings and between layers of high and low voltage windings in a wound coil assembly, after which the assembly can be heated at a temperature and for a time effective to securely bond the winding layers together, to provide a porous, oil permeable, bonded transformer coil assembly.
Inventors
- 👤 Floyd F. Trunzo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:34
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/02; H01F41/04; H01F41/12; H01F41/122
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
266 words
A method of making an oil permeable, bonded transformer comprising the steps of: A. continuously, uniformly coating both sides of a flexible, porous sheet material having a thickness of between about 1 to 30 mils with dry adhesive resin particles having an average particle size of between about 37 to 420 microns, said coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution; B. heating the coated sheet material between about 85° to 250°C for an effective period of time, forming a discontinuous 0.25 to 7 mil dry coating of discrete adhesive particles having substantially rounded cross sections bonded to each side of the sheet material, said adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution, to provide a porous, oil permeable resin particle coated layer insulation; C. winding electrical conductors into turns, to form at least two different windings including a high voltage winding and a low voltage winding and inserting the porous, oil permeable, resin particle coated layer insulation between the high voltage winding and low voltage winding and between layers of the high voltage winding and the low voltage winding, to provide a wound coil assembly; D. heating the wound coil assembly at a temperature and for a time effective to securely bond the winding layers together, while still providing an adhesive covering of the layer insulation of between about 5 to 50 percent, to provide a porous, oil permeable bonded coil assembly; and E. impregnating the wound, bonded coil assembly with an insulating oil
Claim 2
Independent Claim
266 words
A method of making an oil permeable, bonded transformer comprising the steps of: A. continuously, uniformly coating both sides of a flexible, porous sheet material having a thickness of between about 1 to 30 mils with dry adhesive resin particles having an average particle size of between about 37 to 420 microns, said coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution; B. heating the coated sheet material between about 85° to 250°C for an effective period of time, forming a discontinuous 0.25 to 7 mil dry coating of discrete adhesive particles having substantially rounded cross sections bonded to each side of the sheet material, said adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution, to provide a porous, oil permeable resin particle coated layer insulation; C. winding electrical conductors into turns, to form at least two different windings including a high voltage winding and a low voltage winding and inserting the porous, oil permeable, resin particle coated layer insulation between the high voltage winding and low voltage winding and between layers of the high voltage winding and the low voltage winding, to provide a wound coil assembly; D. heating the wound coil assembly at a temperature and for a time effective to securely bond the winding layers together, while still providing an adhesive covering of the layer insulation of between about 5 to 50 percent, to provide a porous, oil permeable bonded coil assembly; and E. impregnating the wound, bonded coil assembly with an insulating oil
Claim 3
Dependent Claim
56 words
The method of claim 1, wherein the wound coil assembly of step (C) is first placed in a transformer container, vacuum impregnated with an insulating oil comprising a hydrocarbon liquid and then the transformer container heated at a temperature and for a time effective to securely bond the winding layers together, while still providing an adhesive
Claim 4
Dependent Claim
39 words
The method of claim 1, wherein the sheet material is a cellulosic sheet material, the resin is a thermoset resin, said resin being bonded to the sheet material but not thermoset in step (B) but being heated to a
Claim 5
Dependent Claim
37 words
The method of claim 1, wherein the resin is applied to the sheet material with an electrostatic spray apparatus, the resin is heated in step (B) by an infrared heater and the sheet material speed through the
Claim 6
Dependent Claim
36 words
The method of claim 3, wherein the sheet material is paper, the thermoset resin comprises an epoxy resin and the wound coil assembly is heated in step (D) between about 100° to 175°C for about 1
Claim 7
Dependent Claim
37 words
The method of claim 3, wherein the conductors are insulated and selected from the group consisting of copper and aluminum, the bonded coil assembly of step (D) is placed in a transformer container and vacuum impregnated in
Claim 8
Dependent Claim
14 words
The method of claim 5, wherein the epoxy resin contains about 10 to 60
Claim 9
Dependent Claim
13 words
The method of claim 5, wherein the paper contains an effective amount of
Claim 10
Independent Claim
210 words
A method of making an oil permeable, bonded electrical apparatus comprising the steps of: A. continuously, uniformly coating both sides of a flexible, porous sheet material having a thickness of between about 1 to 30 mils with dry adhesive resin particles having an average particle size of between about 37 to 420 microns, said coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution; B. heating the coated sheet material between about 85° to 250°C for an effective period of time, forming a discontinuous 0.25 to 7 mil dry coating of discrete adhesive particles having substantially rounded cross sections bonded to each side of the sheet material, said adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution, to provide a porous, oil permeable resin particle coated layer insulation; C. engaging the resin particle coated layer insulation with a conductor; D. heating the combined conductor and layer insulation at a temperature and for a time effective to securely bond the conductor and layer insulation together, while still providing an adhesive covering of the layer insulation of between about 5 to 50 percent; and E. impregnating the combined conductor and layer insulation with an
Claim 11
Independent Claim
210 words
A method of making an oil permeable, bonded electrical apparatus comprising the steps of: A. continuously, uniformly coating both sides of a flexible, porous sheet material having a thickness of between about 1 to 30 mils with dry adhesive resin particles having an average particle size of between about 37 to 420 microns, said coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution; B. heating the coated sheet material between about 85° to 250°C for an effective period of time, forming a discontinuous 0.25 to 7 mil dry coating of discrete adhesive particles having substantially rounded cross sections bonded to each side of the sheet material, said adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution, to provide a porous, oil permeable resin particle coated layer insulation; C. engaging the resin particle coated layer insulation with a conductor; D. heating the combined conductor and layer insulation at a temperature and for a time effective to securely bond the conductor and layer insulation together, while still providing an adhesive covering of the layer insulation of between about 5 to 50 percent; and E. impregnating the combined conductor and layer insulation with an
Claim 12
Dependent Claim
16 words
The method of claim 9 wherein the conductor is an electrical winding of electrical conductor turns.
References Cited (Backward Citations)
US3203823A
Cited
US3246271A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |