US4557704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Junction structure of turbine shaft
Assignee: Niterra Co Ltd
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Filing: 1984-10-31
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Granted: 1985-12-10
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Expires: 2004-10-31
Abstract
Abstract Composite turbine shaft includes a ceramic shaft and a metal shaft, both ends being butt-joined by brazing wherein a center void is provided in the ceramic shaft end so as to secure good heat insulation as well as strong junction even under the difference in thermal expansion between the ceramic shaft and the metal shaft.
Inventors
- 👤 Masaya Ito
- 👤 Seiji Mori
- 👤 Noboru Ishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:00
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/02; F01D5/026; F16; F16C; F16C3/00; F16C3/02; F16D; F16D1/00; F16D1/02; F16D1/027; F16C2226/00; F16C2226/30; F16C2226/32; F16C2226/34; F16C2360/00; F16C2360/23; F16C2360/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
75 words
In a composite shaft comprised of a ceramic shaft and a metal shaft which is butt-joined to the end of the ceramic shaft, the ceramic shaft being on the side of a rotor to be operated at a higher temperature than the metal shaft, the improvement comprises a junction structure of the composite shaft wherein a void for heat insulation is provided only within the central portion of the abutting end of said ceramic shaft.
Claim 2
Dependent Claim
75 words
In a composite shaft comprised of a ceramic shaft and a metal shaft which is butt-joined to the end of the ceramic shaft, the ceramic shaft being on the side of a rotor to be operated at a higher temperature than the metal shaft, the improvement comprises a junction structure of the composite shaft wherein a void for heat insulation is provided only within the central portion of the abutting end of said ceramic shaft.
Claim 3
Dependent Claim
16 words
The shaft as defined in claim 1, wherein the ceramic shaft is solid with the rotor.
Claim 4
Dependent Claim
22 words
The shaft as defined in claim 1, wherein the composite shaft is a turbine shaft and the rotor is a turbine rotor.
Claim 5
Dependent Claim
23 words
The shaft as defined in claim 1, wherein the void has a diameter of no greater than 80% of the ceramic shaft diameter.
Claim 6
Dependent Claim
22 words
The shaft as defined in claim 4, wherein the void has a diameter of at least 30% of the ceramic shaft diameter.
Claim 7
Dependent Claim
22 words
The shaft as defined in claim 5, wherein the void has a length of at least 20% of the ceramic shaft diameter.
Claim 8
Dependent Claim
21 words
The shaft as defined in claim 1, wherein the junction includes brazing to join said ceramic shaft and the metal shaft.
Claim 9
Dependent Claim
21 words
The shaft as defined in claim 7, wherein the junction includes a buffer material layer between the ends of both shafts.
Claim 10
Dependent Claim
24 words
The shaft as defined in claim 7, wherein the junction includes a metallized layer on the surface of the end of the ceramic shaft.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-09 | 1989-06-10 | 1989-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-09 | 1993-06-10 | 1993-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-09 | 1997-06-10 | 1997-12-10 | $7700.00 | Window Closed / Lapsed |