US5240376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
SPF/DB hollow core fan blade
Assignee: McDonnell Douglas Corp
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Filing: 1991-07-31
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Granted: 1993-08-31
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Expires: 2011-07-31
Abstract
Abstract A hollow core fan blade for a gas turbine engine, having a continuous leading edge, is fabricated using a four-sheet superplastic forming/diffusion bonding process which results in a cost-efficient and lightweight, yet strong, structure. The rotor blade is comprised of a face sheet which has a 180 degree bend therein so that the two face sheet ends are aligned. Bonded to opposing sides of the face sheet are first and second core sheets, between which is the hollow core. To fabricate the blade, a core sheet assembly is inserted inside the prepared face sheet, thereby forming a Ti-Pack (titanium pack) assembly having a plurality of pressure-tight cells. The Ti-Pack is inserted into a cavity within a die, after which the rotor blade, having predetermined design characteristics, is superplastically formed by heating the die and selectively pressurizing the plurality of cells.
Inventors
- 👤 Alexander Velicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:28
CPC Classifications
B; B21; B21D; B21D26/00; B21D26/02; B21D26/053; B21D26/055; B23; B23P; B23P15/00; B23P15/04; F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/147; F04; F04D; F04D29/00; F04D29/02; F04D29/023; F04D29/26; F04D29/32; F04D29/321; F04D29/324; F05; F05D; F05D2230/00; F05D2230/20; F05D2230/23; F05D2230/232; F05D2230/236; F05D2230/50; F05D2230/54; F05D2300/00; F05D2300/10; F05D2300/17; F05D2300/174; F05D2300/20; F05D2300/22; F05D2300/226; F05D2300/2261; F05D2300/50; F05D2300/501; F05D2300/60; F05D2300/603; F05D2300/6032; F05D2300/614; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T29/49336; Y10T29/49337; Y10T29/49339; Y10T29/49341
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
110 words
A hollow core rotor blade for a turbine engine, comprising: a generally airfoil-shaped outer structure comprised of a superplastically formed, diffusion bonded sheet material, said outer structure having a trailing edge and a leading edge, said leading edge having an outer surface; and a hollow core spacing having at least one web extending therethrough and being enclosed by said outer structure, said at least one web being either generally vertical or generally horizontal in orientation; wherein the outer surface of said leading edge is formed from a single sheet of material and is therefore structurally continuous and seamless, thereby allowing said rotor blade to be relatively lightweight, efficient, and durable.
Claim 2
Dependent Claim
110 words
A hollow core rotor blade for a turbine engine, comprising: a generally airfoil-shaped outer structure comprised of a superplastically formed, diffusion bonded sheet material, said outer structure having a trailing edge and a leading edge, said leading edge having an outer surface; and a hollow core spacing having at least one web extending therethrough and being enclosed by said outer structure, said at least one web being either generally vertical or generally horizontal in orientation; wherein the outer surface of said leading edge is formed from a single sheet of material and is therefore structurally continuous and seamless, thereby allowing said rotor blade to be relatively lightweight, efficient, and durable.
Claim 3
Dependent Claim
22 words
The rotor blade as recited in claim 1, wherein said at least one web comprises a plurality of vertical or horizontal webs.
Claim 4
Dependent Claim
22 words
The rotor blade as recited in claim 1, wherein said at least one web comprises a plurality of vertical and horizontal webs.
Claim 5
Dependent Claim
25 words
The rotor blade as recited in claim 1, wherein said turbine engine is a gas turbine engine and said rotor blade is a fan blade.
Claim 6
Dependent Claim
18 words
The rotor blade as recited in claim 1, wherein said outer structure is comprised of a titanium alloy.
Claim 7
Dependent Claim
28 words
The rotor blade as recited in claim 1, wherein said outer structure is comprised of a matrix structure, with composite fibers being embedded within said superplastically formed material.
Claim 8
Dependent Claim
24 words
The rotor blade as recited in claim 6, wherein said fibers are oriented in a longitudinal direction, thereby increasing bending stiffness of the blade.
Claim 9
Dependent Claim
14 words
The rotor blade as recited in claim 6, wherein said fibers comprise silicon carbide.
Claim 10
Dependent Claim
44 words
The rotor blade as recited in claim 6, wherein said outer structure is comprised of a titanium metal matrix structure, with silicon carbide fibers being embedded therein, said silicon carbide fibers being oriented in a longitudinal direction to increase bending stiffness of the blade.
Claim 11
Dependent Claim
17 words
The rotor blade as recited in claim 6, wherein said composite fibers comprise silicon carbide fiber mats.
Claim 12
Dependent Claim
115 words
A hollow core rotor blade for a turbine engine, comprising: a generally airfoil-shaped outer structure comprised of a superplastically formed, diffusion bonded sheet material, said outer structure having a trailing edge and a leading edge and being comprised of a matrix structure, with generally longitudinally oriented composite fibers being embedded within said superplastically formed material to increase the bending stiffness of the blade, said leading edge having an outer surface; and a hollow core spacing enclosed by said outer structure; wherein the outer surface of said leading edge is formed from a single sheet of material and is therefore structurally continuous and seamless, thereby allowing said rotor blade to be relatively lightweight, efficient, and durable.
Claim 13
Dependent Claim
115 words
A hollow core rotor blade for a turbine engine, comprising: a generally airfoil-shaped outer structure comprised of a superplastically formed, diffusion bonded sheet material, said outer structure having a trailing edge and a leading edge and being comprised of a matrix structure, with generally longitudinally oriented composite fibers being embedded within said superplastically formed material to increase the bending stiffness of the blade, said leading edge having an outer surface; and a hollow core spacing enclosed by said outer structure; wherein the outer surface of said leading edge is formed from a single sheet of material and is therefore structurally continuous and seamless, thereby allowing said rotor blade to be relatively lightweight, efficient, and durable.
Claim 14
Dependent Claim
14 words
The rotor blade as recited in claim 11, wherein said fibers comprise silicon carbide.
Claim 15
Dependent Claim
17 words
The rotor blade as recited in claim 11, wherein said composite fibers comprise silicon carbide fiber mats.
Claim 16
Dependent Claim
14 words
The rotor blade as recited in claim 11, wherein said matrix structure comprises titanium.
References Cited (Backward Citations)
GB524138A
Cited
US2759246A
Cited
US3623204A
Cited
US4043498A
Cited
US4217397A
Cited
US4343593A
Cited
US4882823A
Cited
US5018271A
Cited
US4934580A
Cited
US5072871A
Cited
US5099573A
Cited
US5083371A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-30 | 1997-03-01 | 1997-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-30 | 2001-03-01 | 2001-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-30 | 2005-03-01 | 2005-08-31 | $7700.00 | Window Closed / Lapsed |