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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
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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 05:18
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
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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

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