FABRICATED HYBRID TURBINE BLADE
A blade for a turbine includes: a support structure of high strength material as a central portion of the blade, the support structure including a root and a body extending to a tip, the body providing a leading edge, a trailing edge and mounting section; and a honeycomb skin attached to the mounting section for providing a lightweight airfoil portion of the blade. A method and a turbine are included.
Latest General Electric Patents:
- GAS TURBINE ENGINES INCLUDING EMBEDDED ELECTRICAL MACHINES AND ASSOCIATED COOLING SYSTEMS
- GAS DELIVERY SYSTEM OF AN ADDITIVE MANUFACTURING MACHINE
- System and method for analyzing noise in electrophysiology studies
- Methods and systems for cable management
- Unit cell structures including stiffening patterns
1. Field of the Invention
The invention herein relates to rotating components for a turbine and in particular to embodiments of turbine blades.
2. Description of the Related Art
Turbine engines, such as those used for aircraft propulsion and power generation, rely upon arrays of aerodynamic blades for turning of a central shaft. Depending on a location within the turbine, the blade may be subjected to thermal stress arising from combustion gases. In addition, all of the blades (also referred to as “buckets”) are subject to mechanical stress associated with rotation about a central axis of the shaft.
Many designs for blades are known. However, due at least to demands for improved output and efficiency of each turbine, there is an ever increasing need for lighter weight and more mechanically robust blades.
BRIEF DESCRIPTION OF THE INVENTIONIn one embodiment, the invention includes a blade for a turbine, the blade including: a support structure of high strength material, as a central portion of the blade, the support structure including a root and a body extending to a tip, the body providing a leading edge, a trailing edge and a mounting section; and a honeycomb skin attached to the mounting section for providing a lightweight airfoil portion of the blade.
In another embodiment, the invention includes a method for fabricating a blade for a turbine, the method including: using a high strength material, forming a central portion of the blade, the central portion including a root and a body extending to a tip, the body providing a leading edge, a trailing edge and mounting section; and attaching a honeycomb skin to a surface of the central portion to provide an airfoil of the blade.
In a further embodiment, the invention includes a turbine including: at least one blade including a support structure of high strength material, the support structure including a root and a body extending to a tip, the body providing a leading edge, a trailing edge and a mounting section; and a honeycomb skin attached to the mounting section for providing a lightweight airfoil portion of the blade.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTIONReferring now to
The terminology “compressor” “low pressure turbine,” “steam turbine” and the like are illustrative of locations within the turbine 1 where the blades disclosed herein may be used. Accordingly, such terminology is merely illustrative and is not limiting of the invention herein.
Referring now to
In general, the blade 10 includes a high strength support structure 21. The high strength support structure 21 assumes an aerodynamic shape near the root (refer to sections D-D and C-C in
For convenience, the high strength support structure 21 may be referred to as a “core” or a “central portion” and by other similar terms. The honeycomb skin 23 may be referred to as providing a “airfoil” “an aerodynamic portion” and by other similar terms.
Exemplary materials for the high strength support structure 21 and the honeycomb skin 23 include alloys such as a superalloy, a cobalt based alloy, a hardened alloy, a carbide based alloy, a nickel based alloy, a undirectionally solidified alloy, an iron based alloy, a wrought austenitic stainless steel, a martensitic stainless steel, a ferritic stainless steel, a carbon steel, a common titanium alloy and an inter-metallic titanium alloy. In some embodiments, a ceramic matrix composite material may be used.
The high strength support structure 21 may be fabricated using various techniques, such as, without limitation, casting, forging, welding (such as to assemble various parts), brazing, sanding, polishing, etching and the like. Fabrication of the high strength support structure 21 may include execution of combinations of techniques and through various stages of assembly.
In some embodiments, the high strength support structure 21 includes one to many perforations (not shown). In further embodiments, the high strength support structure 21 may include at least one of concave and convex gripping features. In such embodiments, the perforations and the gripping features 24 (examples being shown in
The honeycomb skin 23 may be attached to the high strength support structure 21 by use of various techniques. For example the honeycomb skin 23 may be at least one of brazed, such as by using braze tapes or powder, welded such as by fusion welding, bonded, such as by diffusion bonding and attached by other techniques. In general, the honeycomb skin 23 is attached to the high strength support structure 21 using techniques that provide for durable operation of the blade 10 under normal operating conditions.
Referring now to
Referring now to
The recessed zone may be included by a variety of techniques, such as, for example, machining, casting, etching and the like. Included in the recessed zone may be at least one gripping feature 24. The gripping feature 24 generally provides an irregular surface feature to improve the attachment of the overlap 41 or the honeycomb skin 23.
Referring now to
An aspect ratio (Height, H, divided by Width, W (H/W)) for each cell 55 is about 2.5. However, the aspect ratio may range from about 0.5 to about 6.
As also shown in
Referring now to
Having thus described aspects of the blade 10, it should be noted that the blade 10 may be implemented as a rotating component in any one of an aircraft engine (gas turbine 1), power generation gas turbine 1 and steam turbine 1.
For implementation in the aircraft engine, the blade 10 may be implemented advantageously in the fan compressor forward stages and the low pressure turbine latter stages. Similarly for the power generation gas turbine 1, the blade 10 may be implemented advantageously in the compressor forward stages and the turbine latter stages. In a steam turbine application, the blade 10 could be implemented advantageously in the low pressure section where the rotating blades become very large.
Accordingly, the teachings herein provide for a large annulus area blade that uses a light weight honeycomb skin 23 forming an airfoil bonded (i.e., attached) to the high strength support structure 21.
This results in improved gas turbine output and efficiency by increased exit annulus area beyond a conventional high strength alloy casting. As the turbine power gets larger, a higher exit annulus area is required to maintain efficiency. In prior art designs, mass of the airfoil may increase exponentially to maintain stresses within material capability. In contrast, this invention reduces mass of the airfoil by replacing solid metal with the honeycomb skin 23.
In some embodiments, the high strength support structure 21 includes a thin wall casting or forging with a wall thickness less than about 0.03 inches at the tip 11. In other embodiments, an overall reduction of weight for the blade 10 is about 50%.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Claims
1. A blade for a turbine, the blade comprising:
- a support structure of high strength material, as a central portion of the blade, the support structure comprising a root and a body extending to a tip, the body providing a leading edge, a trailing edge and a mounting section; and
- a honeycomb skin attached to the mounting section for providing a lightweight airfoil portion of the blade.
2. The blade as in claim 1, wherein the support structure comprises one to many perforations.
3. The blade as in claim 1, wherein the support structure comprises at least one gripping feature.
4. The blade as in claim 1, wherein the support structure comprises a material that is at least one of a superalloy, a cobalt based alloy, a hardened alloy, a carbide based alloy, a nickel based alloy, a undirectionally solidified alloy, a iron based alloy, a wrought austenitic stainless steel, a martensitic stainless steel, a ferritic stainless steel, a carbon steel, a common titanium alloy and an inter-metallic titanium alloy.
5. The blade as in claim 1, wherein the honeycomb skin comprises a material that is at least one of a superalloy, a cobalt based alloy, a hardened alloy, a carbide based alloy, a nickel based alloy, a undirectionally solidified alloy, a iron based alloy, a wrought austenitic stainless steel, a martensitic stainless steel, a ferritic stainless steel, a carbon steel, a common titanium alloy and an inter-metallic titanium alloy.
6. The blade as in claim 1, comprising an overlap of honeycomb skin on at least one of the leading edge and the trailing edge.
7. The blade as in claim 1, wherein an interface between the mounting section and the honeycomb skin comprises at least one of a brazed, a bonded and a welded interface.
8. The blade as in claim 1, wherein the honeycomb skin further comprises an inner surface.
9. The blade as in claim 1, wherein an angle between a wall of the honeycomb skin and a plane that is normal to a face of the mounting section is between about minus sixty degrees to about plus sixty degrees.
10. The blade as in claim 1, wherein an angle for a vertex of a cell of the honeycomb skin is between about twenty degrees to about seventy degrees.
11. The blade as in claim 1, wherein an aspect ratio for cells of the honeycomb skin ranges between about 0.5 to about 6.
12. A method for fabricating a blade for a turbine, the method comprising:
- using a high strength material, forming a central portion of the blade, the central portion comprising a root and a body extending to a tip, the body providing a leading edge, a trailing edge and mounting section; and
- attaching a honeycomb skin to a surface of the central portion to provide an airfoil of the blade.
13. The method as in claim 12, wherein attaching comprises at least one of brazing, bonding, welding and fusing the honeycomb skin to the central portion.
14. The method as in claim 12, further comprising attaching an overlap to at least one of the trailing edge and the leading edge.
15. The method as in claim 12, further comprising designing the support structure to include dimensions for installation into one of a compressor of a gas turbine, a low pressure turbine, and a steam turbine.
16. The method as in claim 12, wherein forming comprises at least one of casting, forging, welding, brazing, sanding, polishing and etching.
17. A turbine comprising:
- at least one blade comprising a support structure of high strength material, the support structure comprising a root and a body extending to a tip, the body providing a leading edge, a trailing edge and a mounting section; and
- a honeycomb skin attached to the mounting section for providing a lightweight airfoil portion of the blade.
18. The turbine of claim 17, wherein at least one blade is comprised within one of a compressor of a gas turbine, a low pressure turbine, and a steam turbine.
19. The turbine of claim 17, comprising one of an aircraft gas turbine and a power generation gas turbine.
Type: Application
Filed: Oct 28, 2008
Publication Date: Apr 29, 2010
Applicant: GENERAL ELECTRIC COMPANY (Schenectady, NY)
Inventors: James William Vehr (Easley, SC), Paul Stephen Dimascio (Greer, SC), Bradley Taylor Boyer (Greenville, SC)
Application Number: 12/259,599
International Classification: F01D 5/14 (20060101);