US5581869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Repair method for sealing liquid-cooled stator bar end fittings for a generator
Assignee: General Electric Co
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Filing: 1995-08-15
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Granted: 1996-12-10
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Expires: 2015-08-15
Abstract
Abstract The method includes repairing the stator bar end fittings used for the electrical and hydraulic connections at the stator bar ends of a generator with suitable integrity to be as good as new or better than an in-kind replacement with new components for the stator bar. The method addresses the need to repair leaks in liquid cooled generator end windings and the respective end fittings. In particular, the method repairs leaks that develop between the joints of interior adjacent strands and between the outermost strands and the end fitting. The method employs the replacement of the original end fitting with another end fitting similar in geometry. A majority of the original end fitting along with the original window (if any) is preserved and utilized as a ring to surround and compress the strand bundle, with the original braze intact, thus preserving the original geometry of the strand bundle. After repairing the strands, the machined ring is inserted into the replacement end fitting and brazed with an alloy with a lower temperature melting point than the original alloy in order to keep intact the prior brazing. The replacement end fitting of the repaired stator bar end may now be connected to the generator winding, insulated and returned to service in the same manner as that of a new stator bar.
Inventors
- 👤 Andrew J. Travaly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:21
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/04; H02K3/24; H02K15/00; H02K15/30; H02K15/33; H02K15/35; H02K15/38; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/49718; Y10T29/49721; Y10T29/49723; Y10T29/49725; Y10T29/49726; Y10T29/49728; Y10T29/49732; Y10T29/49742
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
128 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of: removing a portion of said end fitting to expose the ends of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing any voids in the original braze between said strands and said ring by brazing with a second alloy; inserting said ring and said strand ends into a replacement end fitting having an internal cavity shaped to receive said ring and said strand ends; brazing said ring into said replacement end fitting.
Claim 2
Independent Claim
128 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of: removing a portion of said end fitting to expose the ends of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing any voids in the original braze between said strands and said ring by brazing with a second alloy; inserting said ring and said strand ends into a replacement end fitting having an internal cavity shaped to receive said ring and said strand ends; brazing said ring into said replacement end fitting.
Claim 3
Dependent Claim
21 words
The method according to claim 1 wherein the step of removing a portion of said end fitting is accomplished by machining.
Claim 4
Dependent Claim
20 words
The method according to claim 1 wherein at least one of said strands brazed into said end fitting is hollow.
Claim 5
Dependent Claim
24 words
The method according to claim 1 wherein the original end fitting has a side having a cut-out section over which is placed a window.
Claim 6
Dependent Claim
16 words
The method according to claim 1 wherein the original end fitting comprises a four sided housing.
Claim 7
Dependent Claim
16 words
The method according to claim 1 wherein the replacement end fitting comprises a four sided housing.
Claim 8
Dependent Claim
34 words
The method according to claim 1 further including the step of cleaning the areas between a strand and either an adjacent strand or the interior of said continuous ring prior to brazing a void.
Claim 9
Dependent Claim
16 words
The method according to claim 7 wherein the step of cleaning includes using a chemical solvent.
Claim 10
Dependent Claim
28 words
The method according to claim 1 wherein said void is braze repaired with a repair alloy whose temperature melting point is lower than that of the original alloy.
Claim 11
Dependent Claim
42 words
The method according to claim 1 wherein said replacement end fitting is brazed with an alloy whose temperature melting point is lower than either the original or repair alloys used so as not to disturb the original braze during said brazing process.
Claim 12
Independent Claim
121 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of: removing a portion of said end fitting to expose the ends of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing any voids in the original braze between the strands by brazing; inserting said ring and said strand ends into a replacement end fitting having an internal cavity shaped to receive said ring and said strand ends; brazing said ring into said replacement end fitting.
Claim 13
Independent Claim
121 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of: removing a portion of said end fitting to expose the ends of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing any voids in the original braze between the strands by brazing; inserting said ring and said strand ends into a replacement end fitting having an internal cavity shaped to receive said ring and said strand ends; brazing said ring into said replacement end fitting.
Claim 14
Dependent Claim
21 words
The method according to claim 1 wherein the step of removing a portion of said end fitting is accomplished by machining.
Claim 15
Dependent Claim
20 words
The method according to claim 1 wherein at least one of said strands brazed into said end fitting is hollow.
Claim 16
Dependent Claim
24 words
The method according to claim 1 wherein the original end fitting has a side having a cut-out section over which is placed a window.
Claim 17
Dependent Claim
16 words
The method according to claim 1 wherein the original end fitting comprises a four sided housing.
Claim 18
Dependent Claim
16 words
The method according to claim 1 wherein the replacement end fitting comprises a four sided housing.
Claim 19
Dependent Claim
34 words
The method according to claim 1 further including the step of cleaning the areas between a strand and either an adjacent strand or the interior of said continuous ring prior to brazing a void.
Claim 20
Dependent Claim
16 words
The method according to claim 7 wherein the step of cleaning includes using a chemical solvent.
Claim 21
Dependent Claim
28 words
The method according to claim 1 wherein said void is braze repaired with a repair alloy whose temperature melting point is lower than that of the original braze.
Claim 22
Dependent Claim
44 words
The method according to claim 11 wherein said ring is brazed into said replacement fitting with an alloy whose temperature melting point is lower than either the original or repair alloys used so as not to disturb the such brazes during said brazing process.
Claim 23
Independent Claim
98 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of. removing a portion of said end fitting to expose said one end of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing voids in the original braze alloy between the remaining strands; and securing a replacement end fitting to said continuous ring.
Claim 24
Independent Claim
98 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of. removing a portion of said end fitting to expose said one end of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing voids in the original braze alloy between the remaining strands; and securing a replacement end fitting to said continuous ring.
Claim 25
Independent Claim
118 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of: removing a portion of said end fitting to expose said one end of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing any voids in the original braze alloy between said strands and said ring by brazing with a second alloy; and brazing a replacement end fitting having a cavity to receive said one end of said strands to said continuous ring.
Claim 26
Independent Claim
118 words
A method of repairing a stator bar having a plurality of strands brazed with an original alloy into an end fitting surrounding one end of said strands, comprising the steps of: removing a portion of said end fitting to expose said one end of the strands, the remaining portion of said end fitting shaped in the form of a continuous ring around said strands and having some original braze alloy remaining between said strands and said ring; sealing any voids in the original braze alloy between said strands and said ring by brazing with a second alloy; and brazing a replacement end fitting having a cavity to receive said one end of said strands to said continuous ring.
References Cited (Backward Citations)
US4274021A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-12-10 | 2000-06-10 | 2000-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-10 | 2004-06-10 | 2004-12-10 | $3760.00 | Window Closed / Lapsed |
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