US5088894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Turbomachine blade fastening
Assignee: Siemens Energy Inc
•
Filing: 1990-05-02
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Granted: 1992-02-18
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Expires: 2010-05-02
Abstract
Abstract Crack formation in the root portion of a turbine blade is prevented by locating the trailing edge of the air foil portion at the base section thereof in close vertical proximity to the uppermost root neck, thus minimizing trailing edge overhang which has been determined to be the cause of root tracking.
Inventors
- 👤 Ashok T. Patel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:02
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/141; F05; F05D; F05D2240/00; F05D2240/20; F05D2240/30; F05D2240/301
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
211 words
A turbine blade comprising: an air foil portion having a leading edge, a trailing edge, a convex suction-side surface, a concave pressure-side surface, a tip section at one end, and a base section at the other, opposite end; a platform portion from which the air foil portion extends and having a convex side and a concave side; a root portion having a convex side, a concave side, a root center line and extending from the platform portion in a direction opposite the air foil portion and having a plurality of root necks including an uppermost root neck, each root neck having symmetrically formed opposite surfaces extending radially inwardly towards the root center line and having a width corresponding to the horizontal straight line distance between two parallel arcuate lines defined by radially innermost points on the opposite surfaces, wherein, at a plane section where the air foil portion meets the platform portion, the trailing edge of the air foil portion is in close proximity to the arcuate line of the uppermost root neck on the concave side of the root portion to minimize trailing edge overhang and wherein the airfoil portion is free standing and has a length of 32 inches, and the uppermost root neck width is about 1.56 inches.
Claim 2
Dependent Claim
211 words
A turbine blade comprising: an air foil portion having a leading edge, a trailing edge, a convex suction-side surface, a concave pressure-side surface, a tip section at one end, and a base section at the other, opposite end; a platform portion from which the air foil portion extends and having a convex side and a concave side; a root portion having a convex side, a concave side, a root center line and extending from the platform portion in a direction opposite the air foil portion and having a plurality of root necks including an uppermost root neck, each root neck having symmetrically formed opposite surfaces extending radially inwardly towards the root center line and having a width corresponding to the horizontal straight line distance between two parallel arcuate lines defined by radially innermost points on the opposite surfaces, wherein, at a plane section where the air foil portion meets the platform portion, the trailing edge of the air foil portion is in close proximity to the arcuate line of the uppermost root neck on the concave side of the root portion to minimize trailing edge overhang and wherein the airfoil portion is free standing and has a length of 32 inches, and the uppermost root neck width is about 1.56 inches.
Claim 3
Dependent Claim
17 words
A turbine blade as recited in claim 1, wherein the trailing edge overlies the uppermost root neck.
Claim 4
Dependent Claim
25 words
A turbine blade as recited in claim 1, wherein the leading edge has a diameter which decreases from the base section to the tip section.
Claim 5
Dependent Claim
26 words
A turbine blade as recited in claim 1, wherein the suction-side surface of the air foil portion has a flat-back portion extending from the trailing edge.
Claim 6
Dependent Claim
26 words
A turbine blade as recited in claim 4, wherein the flat back portion has a length which increases from the base section to the tip section.
Claim 7
Dependent Claim
32 words
A turbine blade as recited in claim 5, wherein the flat back portion is angled relative to vertical, and the degree of angle decreases from the base section to the tip section.
Claim 8
Dependent Claim
21 words
A turbine blade as recited in claim 6, wherein the tip section angle of the flat back portion is about 40.
Claim 9
Dependent Claim
25 words
A turbine blade as recited in claim 1, wherein the trailing edge has a width which decreases from the base section to the tip section.
References Cited (Backward Citations)
US1719415A
Cited
US1793468A
Cited
US2027745A
Cited
US2709052A
Cited
US2848193A
Cited
US3112914A
Cited
US4650399A
Cited
EP0112003A1
Cited
US4824328A
Cited
US4919593A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-17 | 1995-08-19 | 1996-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-17 | 1999-08-19 | 2000-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-17 | 2003-08-19 | 2004-02-18 | $7700.00 | Window Closed / Lapsed |