Patent US5035578A successfully refreshed from Google Patents.
US5035578A
Expired / Lapsed
US
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Blading for reaction turbine blade row
Assignee: Siemens Energy Inc
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Filing: 1989-10-16
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Granted: 1991-07-30
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Expires: 2009-10-16
Abstract
Abstract A blade for a steam turbine has a concave, pressure-side surface which has a constant radius of curvature, while the convex, suction-side surface has a continuously increasing radius curvature. The constantly increasing radius of curvature allows fluid to accelerate and thus ensure a small boundary layer of thickness. The center of gravity of the blade tenon is located above the center of gravity of the airfoil which will reduce the steam bending stress applied at the base of the airfoil as well as at the root of the rotor blade.
Inventors
- 👤 Mank H. Tran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:00
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/141; Y; Y10; Y10S; Y10S416/00; Y10S416/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
87 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; and a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edges, convex and concave surfaces forming an airfoil, wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge; and wherein blade orientation is about 46°±3°.
Claim 2
Dependent Claim
87 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; and a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edges, convex and concave surfaces forming an airfoil, wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge; and wherein blade orientation is about 46°±3°.
Claim 3
Dependent Claim
101 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; and a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edge, convex and concave surfaces forming an airfoil, wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge, and wherein the radius of curvature along the concave, pressure-side surface is substantially constant, and wherein blade orientation is about 46°±3°.
Claim 4
Dependent Claim
101 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; and a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edge, convex and concave surfaces forming an airfoil, wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge, and wherein the radius of curvature along the concave, pressure-side surface is substantially constant, and wherein blade orientation is about 46°±3°.
Claim 5
Dependent Claim
163 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edge, convex and concave surfaces forming an airfoil, wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge; and a tenon formed on top of the airfoil, a cross-section of the tenon having a center of gravity offset from a center of gravity of the blade airfoil, wherein the center of gravity of the airfoil is at an intersection of x--x and y--y axes, and the center of gravity of a cross-section of the tenon is located near the y--y axis and above the center of gravity of the airfoil, wherein the x--x axis is in the direction of the steam flow.
Claim 6
Dependent Claim
163 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edge, convex and concave surfaces forming an airfoil, wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge; and a tenon formed on top of the airfoil, a cross-section of the tenon having a center of gravity offset from a center of gravity of the blade airfoil, wherein the center of gravity of the airfoil is at an intersection of x--x and y--y axes, and the center of gravity of a cross-section of the tenon is located near the y--y axis and above the center of gravity of the airfoil, wherein the x--x axis is in the direction of the steam flow.
Claim 7
Dependent Claim
24 words
A blade for a steam turbine as recited in claim 3, wherein the radius of curvature along the concave, pressure-side surface is substantially constant.
Claim 8
Dependent Claim
17 words
A blade for a steam turbine as recited in claim 3, wherein blade orientation is about 46°±3°.
Claim 9
Dependent Claim
35 words
A blade for a steam turbine as recited in claim 3, wherein the axis of the minimum principal moment of inertia of the tenon is at about a 65° angle relative to the x--x axis.
Claim 10
Dependent Claim
174 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edge, convex and concave surfaces forming an airfoil; wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge, and wherein the radius of curvature along the concave, pressure-side surface is substantially constant; a tenon formed on top of the airfoil, a cross-section of the tenon having a center of gravity offset from a center of gravity of the airfoil, wherein the center of gravity of the airfoil is at an intersection of x--x and y--y axes, and he center of gravity of a cross-section of the tenon is located near the y--y axis and above the center of gravity of the airfoil, wherein the x--x axis is in the direction of steam flow.
Claim 11
Dependent Claim
174 words
A blade for a steam turbine comprising: a leading edge; a trailing edge; a concave, pressure-side surface extending between the leading and trailing edges, and having a radius of curvature; a convex, suction-side surface extending between the leading and trailing edges, and having a radius of curvature, said leading edge, trailing edge, convex and concave surfaces forming an airfoil; wherein the radius of curvature along the convex, suction-side surface continuously increases from the leading edge to the trailing edge, and wherein the radius of curvature along the concave, pressure-side surface is substantially constant; a tenon formed on top of the airfoil, a cross-section of the tenon having a center of gravity offset from a center of gravity of the airfoil, wherein the center of gravity of the airfoil is at an intersection of x--x and y--y axes, and he center of gravity of a cross-section of the tenon is located near the y--y axis and above the center of gravity of the airfoil, wherein the x--x axis is in the direction of steam flow.
Claim 12
Dependent Claim
17 words
A blade for a steam turbine as recited in claim 7, wherein blade orientation is about 46°±3°.
Claim 13
Dependent Claim
32 words
A blade for a steam turbine as recited in claim 7, wherein the minimum principal moment of inertia of the tenon is at about a 65° angle relative to the x--x axis.
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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) | 1994-07-29 | 1995-01-28 | 1995-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-29 | 1999-01-28 | 1999-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-29 | 2003-01-28 | 2003-07-30 | $7700.00 | Window Closed / Lapsed |