Technical Field
Disclosed herein are fan blades for gas turbine engines and methods of manufacturing such fan blades. The disclosed fan blades include at least one cavity in the airfoil section of the fan blade and at least one through hole that extends from the root of the fan blade to the cavity.
Description of the Related Art
In the field of gas turbine engines used for aircraft, weight reduction results in fuel savings. One known means for reducing the weight of a gas turbine engine is to include hollow cavities in some of the components that do not need to be solid metal or solid composite material to meet structural requirements. One such component is a fan blade, also known as a type of airfoil. Some fan blades include a titanium or aluminum body with recesses or cavities disposed in the non-flow path convex side of the fan blade, also known as the suction side of the fan blade. The opposite side of the fan blade is the concave or pressure side. The cavities may be covered by a composite cover, typically made from fibers and resin. The cover is may be coated with a damage resistant coating.
While fan blades with cavities contribute to weight reduction, there is a continuing need for additional means for reducing the weight of gas turbine engine components while not adversely affecting the strength of the component. This need still extends to fan blades, including fan blades with covered cavities as discussed above. Consequently, there is a continued need for improved fan blade designs that are lightweight, but structurally strong enough to meet all operating requirements.
In one aspect, a light weight fan blade for a gas turbine engine is disclosed. The fan blade may include an airfoil connected to a root. The airfoil may include a pressure side and a suction side. The suction side may include at least one cavity. The fan blade may further include at least one through hole extending through the root to the cavity.
In another aspect, a fan blade assembly is disclosed. The disclosed fan blade assembly may include a hub coupled to a plurality of radially outwardly extending fan blades. Each fan blade may include an airfoil connected to a root. Each airfoil may include a pressure side and a suction side. Each suction side may include at least one cavity. And, each fan blade may also include at least one through hole extending from the root to the cavity of its respective fan blade.
In yet another aspect, a method for fabricating a fan blade of a gas turbine engine is disclosed. The disclosed method may include manufacturing a body that includes an airfoil and a root. The airfoil may include a pressure side and a suction side. The suction side may include at least one cavity. The method may further include forming at least one through hole through the root and into the cavity. The through hole may be formed by drilling, ball end milling, laser hole manufacturing or other techniques known to those skilled in the art. The method may further include covering the cavity with a cover.
In any one or more of the embodiments described above, each root may include an inner face disposed between and connected to a pair of pressure faces. The pressure faces may extend from the interface to the airfoil. Further, the through hole may extend from the inner face of the root to the cavity.
In any one or more of the embodiments described above, the through hole(s) may be capped or plugged at the inner face of the root to prevent migration of condensation.
In any one or more of the embodiments described above, the at least one through hole is a plurality of through holes.
In any one or more of the embodiments described above, a cover may be disposed over the cavity and adhered to the suction side of the airfoil.
In any one or more of the embodiments described above, the cavity may include a plurality of cavities.
In any one or more of the embodiments described above, the fan blade may further include a plurality of through holes, each through hole extending from the root to one of the plurality of cavities.
In any one or more of the embodiments described above, the cover for the cavity or cavities may be fabricated from fibers and resin.
In any one or more of the embodiments described above, the cover for the cavity or cavities may be fabricated from a fluoroelastomer.
In any one or more of the embodiments described above, the cavity may include at least three cavities and the through hole may include at least six through holes, with two through holes extending from the root to each cavity.
In any one or more of the embodiments described above, the fan blade may further include at least one hole that extends from the root into the airfoil, but which terminates short of the cavity or cavities.
In any one or more of the embodiments described above, the cavity may include a plurality of cavities and the through hole may include a plurality of through holes. Each through hole may extend from the root to one of the cavities. Further, the fan blade may further include at least one hole that extends from the root into the airfoil, but which terminates short of any of the plurality of cavities. In a further refinement of this concept, the fan blade may include a plurality of holes that extend from the root into the airfoil, but which terminate short of any of the plurality of cavities.
In any one or more of the embodiments described above, the inner face of the root may be covered with a spacer that is received in a slot in the rotor that accommodates the root of the airfoil. More specifically, the spacer may be sandwiched between the inner face of the root and the base surface of the slot in the rotor that accommodates the root of the fan blade.
Other advantages and features will be apparent from the following detailed description when read in conjunction with the attached drawings.
For a more complete understanding of the disclosed methods and apparatuses, reference should be made to the embodiment illustrated in greater detail on the accompanying drawings, wherein:
It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein.
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For aerodynamic purposes, the cavity or cavities 33 may be covered with a robust, yet lightweight cover 31 as shown in
Typically, the cover 31 may be fabricated from a fiber/resin composite material such as carbon fiber reinforced polymer (CFRP) and/or glass fiber reinforced polymer (GFRP) or an elastomer, such as a fluropolymer elastomer like VITONĀ®. Alternatively, the cover 31 may be metallic, such as, but not limited to, aluminum, titanium, or various alloys thereof. If the cover 31 is fabricated from a metal or alloy, an additional coating may be optional. However, an additional coating may be applied over the cover 31 if the cover is fabricated from a CFRP, GFRP, fluropolymer elastomer or other composite materials.
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While only certain embodiments of been set forth, alternative embodiments and various modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of the present disclosure.
This application is a National Phase Application of Patent Application PCT/US2014/051196 filed on Aug. 15, 2014, which claims the benefit of and priority to U.S. Provisional Patent Application No. 61/921,719 filed Dec. 30, 2013, the contents each of which are incorporated herein by reference in their entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2014/051196 | 8/15/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/102676 | 7/9/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5407326 | Lardellier | Apr 1995 | A |
5634771 | Howard et al. | Jun 1997 | A |
5692881 | Leibfried | Dec 1997 | A |
6296172 | Miller | Oct 2001 | B1 |
6431837 | Velicki | Aug 2002 | B1 |
7118346 | Read | Oct 2006 | B2 |
7972116 | Read | Jul 2011 | B2 |
8366378 | Beckford | Feb 2013 | B2 |
8545183 | Webb | Oct 2013 | B2 |
20040169022 | Mega et al. | Sep 2004 | A1 |
20080014095 | Moniz | Jan 2008 | A1 |
Number | Date | Country |
---|---|---|
0924381 | Jun 1999 | EP |
0926312 | Jun 1999 | EP |
844068 | Aug 1960 | GB |
Entry |
---|
International Search Report for International Application No. PCT/US2014/051196; dated Nov. 24, 2014. |
Written Opinion for International Application No. PCT/US2014/051196; dated Nov. 24, 2014. |
Supplementary European Search Report for Application No. EP 14 87 7448. |
Number | Date | Country | |
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20160327055 A1 | Nov 2016 | US |
Number | Date | Country | |
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61921719 | Dec 2013 | US |