Gas turbine engine rotor blade having root section with composite and metallic portions

Abstract

A rotor blade for a gas turbine engine includes an airfoil section and a root section extending between an upstream surface and a downstream surface in a longitudinal direction. The root section further extends between an inner surface at an inner end of the root section and an outer end coupled to the airfoil section along a radial direction. Further, the root section extends between a first side surface and a second side surface along a circumferential direction. Further, the root section defines a longitudinal centerline extending along the longitudinal direction, the longitudinal centerline positioned equidistant from the inner surface and the outer end in the radial direction. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, the longitudinal centerline extending through the second portion of the root section.

Description

[0001] This application is a divisional application of the invention patent application filed on September 3, 2021, with application number 202111031773.2 and invention title "Gas Turbine Engine Rotor Blade Having a Root Section with Composite and Metal Parts". Technical Field

[0002] This topic relates to gas turbine engines, and more specifically, to the rotor blades of gas turbine engines. Background Technology

[0003] A turbofan engine typically consists of a fan, a nacelle, and a core gas turbine engine located within the nacelle. During turbofan operation, the core gas turbine engine drives or otherwise rotates the fan's rotor blades relative to the nacelle. The rotation of the rotor blades generates a pressurized airflow, which can support the operation of the core gas turbine engine and / or serve as propulsive thrust for propelling the aircraft.

[0004] Typically, turbofan engines can have either a closed rotor configuration or an open rotor configuration. More specifically, in a closed rotor configuration, the fan is located inside the nacelle. Conversely, in an open rotor configuration, the fan is located outside the nacelle. In this respect, open rotor configurations generally allow for the use of larger fans than closed rotor configurations. However, when the engine has an open rotor configuration, it may be necessary to position one or more metal cables within each rotor blade of the fan. For example, one end of each cable is attached to the root section of the rotor blade, while the other end of the cable is positioned within the airfoil section of the blade.

[0005] In many cases, turbofan rotor blades (e.g., fan rotor blades and / or core gas turbine engines) are formed from composite materials to reduce the weight of the turbofan engine and / or increase its operating temperature range. However, the use of composite materials in turbofan engine rotor blades presents various challenges. For example, it is difficult to securely attach metal cables to the root section of composite fan rotor blades.

[0006] Therefore, improved rotor blades for gas turbine engines will be welcomed in this technology. Summary of the Invention

[0007] Aspects and advantages of the invention will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practice of the invention.

[0008] In one aspect, this subject matter relates to rotor blades for gas turbine engines. The rotor blade includes an airfoil section and a root section, the root section extending longitudinally between an upstream surface and a downstream surface of the root section. The root section further extends radially between an inner surface located at an inner end of the root section and an outer end connected to the airfoil section. Furthermore, the root section extends circumferentially between a first side surface and a second side surface. Additionally, the root section defines a longitudinal centerline extending longitudinally and equidistantly positioned radially from the inner surface and the outer end. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, the longitudinal centerline extending through the second portion of the root section.

[0009] On the other hand, this subject matter relates to a gas turbine engine. The gas turbine engine includes a fan, a compressor section, a turbine section, and rotor blades located within one of the fan, compressor, or turbine sections. The rotor blades further include an airfoil section and a root section, the root section extending longitudinally between an upstream surface and a downstream surface of the root section. The root section further extends radially between an inner surface located at an inner end of the root section and an outer end connected to the airfoil section. Furthermore, the root section extends circumferentially between a first side surface and a second side surface. Additionally, the root section defines a longitudinal centerline extending longitudinally and equidistantly positioned radially from the inner surface and the outer end. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, the longitudinal centerline extending through the second portion of the root section.

[0010] These and other features, aspects, and advantages of the invention will become better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Attached Figure Description

[0011] The complete and practical disclosure of the invention, including its preferred mode, is set forth in the description with reference to the accompanying drawings, for those skilled in the art, wherein:

[0012] Figure 1 This is a schematic cross-sectional view of one embodiment of a gas turbine engine;

[0013] Figure 2 This is a side view of one embodiment of the rotor blades of a gas turbine engine;

[0014] Figure 3 This is a partial perspective view of an embodiment of the root section of a rotor blade of a gas turbine engine;

[0015] Figure 4 It is roughly along Figure 4 The cross-sectional view of the root section taken by line 4-4 in the figure shows, in particular, the longitudinal centerline of the root section extending through the various composite and metal parts of the root section.

[0016] Figure 5 It is roughly along Figure 4 The cross-sectional view of the root section taken by line 5-5 in the figure shows, in particular, the metal portion of the root section that partially forms the various surfaces of the root section;

[0017] Figure 6 This is a partial cross-sectional view of another embodiment of the root section of a rotor blade of a gas turbine engine, particularly showing the composite portion of the root section forming the surface of the root section;

[0018] Figure 7 This is a partial cross-sectional view of another embodiment of the root section of a gas turbine engine rotor blade, specifically showing the metal portion of the root section extending radially outward beyond the bottom end of the airfoil section of the rotor blade; and

[0019] Figure 8 This is a partial cross-sectional view of another embodiment of the root section of a rotor blade of a gas turbine engine, particularly showing that the metal portion of the root section has a different cross-sectional shape than the composite portion of the rotor blade.

[0020] Reference numerals are used repeatedly in this specification and drawings to indicate the same or similar features or elements of the invention. Detailed Implementation

[0021] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each embodiment is provided to explain the invention and not to limit it. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the invention without departing from the scope or spirit of the invention. For example, a feature shown or described as part of one embodiment may be used with another embodiment to produce another embodiment. Therefore, the invention is intended to cover these modifications and variations within the scope of the appended claims and their equivalents.

[0022] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of a single component.

[0023] Furthermore, the terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, while "downstream" refers to the direction in which the fluid flows.

[0024] Furthermore, unless otherwise specified, the terms “low,” “high,” or their corresponding degrees of comparison (e.g., lower, higher, as applicable) refer to relative speeds within the engine. For example, a “low-pressure turbine” operates at pressures typically lower than those of a “high-pressure turbine.” Alternatively, unless otherwise specified, the above terms may be understood as their highest degree. For example, a “low-pressure turbine” may refer to the turbine with the lowest maximum pressure within a turbine section, while a “high-pressure turbine” may refer to the turbine with the highest maximum pressure within a turbine section.

[0025] Generally, this subject matter is designed for rotor blades of gas turbine engines. As described below, the disclosed rotor blades can be incorporated into the fan, compressor, or turbine of a gas turbine engine. More specifically, the rotor blade includes an airfoil section and a root section. The root section extends longitudinally between an upstream surface and a downstream surface. Furthermore, the root section extends radially between an inner surface located at its inner end and an outer end connected to the airfoil section. In this respect, the root section defines a longitudinal centerline that extends longitudinally and is equidistant from the inner surface and the outer end in the radial direction.

[0026] The root section of the rotor blade is formed of a combination of composite and metallic materials. Specifically, in several embodiments, the root section includes one or more portions formed of a composite material (e.g., ceramic matrix composite (CMC)). Furthermore, in these embodiments, the root section includes one or more portions formed of a metallic material, such as a titanium-based alloy, an aluminum-based alloy, and / or a nickel-based alloy. Additionally, a longitudinal centerline of the root section extends through the metallic portion. In some embodiments, the metallic portion forms part of the outer surface of the root section. However, in other embodiments, the composite portion forms the outer surface of the root section (i.e., the metallic portion may be encapsulated within the composite portion).

[0027] Using a rotor blade root section with both a composite portion and a metallic portion, with the longitudinal centerline of the root section extending through the metallic portion, offers various technical advantages. For example, one or more metallic cables can be positioned within the rotor blade. One end of each metallic cable is attached to (e.g., embedded in) the metallic portion of the root section, thus providing a more secure connection than attaching the cable to a fully composite root section. Additionally, including a composite portion within the rotor blade (as opposed to a fully metallic root section) reduces the rotor blade's weight and increases its operating temperature range.

[0028] Now refer to the attached diagram, Figure 1This is a schematic cross-sectional view of one embodiment of a gas turbine engine 10. In the illustrated embodiment, the engine 10 is configured as an open rotor or ductless turbofan engine. However, in alternative embodiments, the engine 10 may be configured as a closed rotor or ducted turbofan engine, a turbojet engine, a turboprop engine, a turboshaft gas turbine engine, or any other suitable type of gas turbine engine.

[0029] Typically, engine 10 includes a fan 12 and a core engine 14 extending along an axial centerline 16. More specifically, fan 12 may include a fan rotor 18 and a plurality of fan rotor blades 20 (one shown) coupled to fan rotor 18. In this respect, the fan rotor blades 20 are spaced apart from each other circumferentially along fan rotor 18 and extend outward from rotor 18. Furthermore, core engine 14 may be positioned downstream of fan 12 along axial centerline 16. As shown, core engine 14 is rotatably coupled to fan rotor 18 via low-pressure (LP) shaft 22, thereby allowing core engine 14 to rotate fan 12.

[0030] In several embodiments, the engine 10 also includes a nacelle or housing 24 surrounding various components of the core engine 14. More specifically, the nacelle 24 typically surrounds or encloses the compressor section 26, combustion section 28, turbine section 30, and exhaust section 32 in a sequential flow order. For example, in some embodiments, the compressor section 26 may include a low-pressure (LP) compressor 34 and a high-pressure (HP) compressor 36, with the high-pressure compressor 36 positioned downstream of the LP compressor 34 along an axial centerline 12. Each compressor 34, 36 may further include one or more rows of stator blades 38 staggered with one or more rows of compressor rotor blades 40. Furthermore, in some embodiments, the turbine section 30 includes a high-pressure (HP) turbine 42 and a low-pressure (LP) turbine 44, with the low-pressure (LP) turbine 44 positioned downstream of the HP turbine 42 along an axial centerline 12. Each turbine 42, 44 may further include one or more rows of stator blades 46 staggered with one or more rows of turbine rotor blades 48.

[0031] Additionally, the engine 10 includes a low-pressure (LP) shaft 22 and a high-pressure (HP) shaft 50 concentrically positioned around the LP shaft 22. In such an embodiment, the HP shaft 50 is rotatably connected to the rotor blades 48 of the HP turbine 42 and the rotor blades 40 of the HP compressor 36, such that rotation of the HP turbine rotor blades 48 rotatably drives the HP compressor rotor blades 40. As shown, the LP shaft 22 is directly connected to the rotor blades 48 of the LP turbine 44 and the rotor blades 40 of the LP compressor 34. Furthermore, the LP shaft 22 is connected to the fan 12 via a gearbox 52. In this respect, rotation of the LP turbine rotor blades 48 rotatably drives the LP compressor rotor blades 40 and the fan blades 20.

[0032] In several embodiments, engine 10 can generate thrust to propel the aircraft. More specifically, during operation of engine 10, fan 12 pressurizes incoming air (indicated by arrow 54). In this respect, a first portion of the pressurized air 54 (indicated by arrow 56) flows around nacelle 24 (i.e., the exterior of nacelle 24) toward the rear of engine 10. Conversely, a second portion of air 54 (indicated by arrow 58) is directed to compressor section 26 of core engine 14. The second portion 58 of air 54 first flows through LP compressor 34, where rotor blades 40 progressively compress the second portion 58 of air 54. Next, the second portion 58 of air 54 flows through HP compressor 36, where rotor blades 40 continue to progressively compress the second portion 58 of air 54. The compressed second portion 58 of air 54 is then delivered to combustion section 28. In combustion section 28, the second portion 58 of air 54 mixes with fuel and burns to produce high-temperature and high-pressure combustion gases 60. Subsequently, the combustion gases 60 flow through the HP turbine 42, from which the HP turbine rotor blades 48 extract a first portion of kinetic and / or thermal energy. This energy extraction causes the HP shaft 50 to rotate, thereby driving the HP compressor 36. The combustion gases 60 then flow through the LP turbine 44, from which the LP turbine rotor blades 48 extract a second portion of kinetic and / or thermal energy. This energy extraction causes the LP shaft 22 to rotate, thereby driving the LP compressor 40 and the fan 12 via the gearbox 52. The combustion gases 60 then exit the core engine 14 through the exhaust section 32.

[0033] The above and Figure 1 The configuration of the gas turbine engine 10 shown is provided only to place the subject matter in an exemplary field of use. Therefore, the subject matter can be readily adapted to any type of gas turbine engine configuration, including other types of aerospace-based gas turbine engines, marine-based gas turbine engines, and / or land-based / industrial gas turbine engines.

[0034] Figure 2 This is a side view of one embodiment of rotor blade 100, which can be incorporated into an engine in place of fan rotor blade 20, compressor rotor blade 40, and / or turbine rotor blade 48. As shown, rotor blade 100 defines a longitudinal direction L, a radial direction R, and a circumferential direction C. Typically, the longitudinal direction L extends parallel to the axial centerline 16 of the engine, the radial direction R extends approximately orthogonally to the axial centerline 16, and the circumferential direction C extends approximately concentrically around the axial centerline 16.

[0035] In some embodiments, the rotor blade 100 includes an airfoil section 102 and a root section 104. More specifically, in these embodiments, the airfoil section 102 extends outwardly from the root section 102 along a radial direction R to a tip 106. Furthermore, the airfoil 102 includes a pressure-side surface 108 and an opposing suction-side surface (not shown). In this respect, the pressure-side surface 108 and the suction-side surface are joined together or interconnected at the leading edge 110 and trailing edge surface 112 of the airfoil 102. Additionally, as will be described below, the root section 104 secures the rotor blade 100 to a rotor disk (not shown), which is coupled to the LP shaft 22 (…). Figure 1 ) or HP axis 50 ( Figure 1 However, in alternative embodiments, rotor blade 100 may have any other suitable configuration. For example, in one embodiment, rotor blade 100 may include a platform positioned along the radial direction R between airfoil section 102 and root section 104.

[0036] Figure 3-5 These are various views of one embodiment of the root section 104 of the rotor blade 100. Specifically, Figure 3 This is a partial 3D view of the root segment 104. Furthermore, Figure 4 It is roughly along Figure 4 A cross-sectional view of the root segment 104 taken from line 4-4. Furthermore, Figure 5 It is roughly along Figure 4 The cross-sectional view of the root segment 104 cut by line 5-5 in the figure.

[0037] like Figure 3-5 As shown, the root section 104 extends along the longitudinal direction L, the radial direction R, and the circumferential direction C. More specifically, the root section 104 extends along the longitudinal direction L between the upstream surface 114 and the downstream surface 116 of the root section 104. Furthermore, the root section 104 extends along the radial direction R between the inner end 118 and the outer end 120 of the root section 104, with the inner surface 122 of the root section 104 located at the inner end 118. The outer end 120 of the root section 104 is connected to the inner end 124 of the airfoil section 102. Additionally, the root section 104 extends along the circumferential direction C between the first side surface 126 and the second side surface 128. Furthermore, as... Figure 4 As shown in the best embodiment, the root section 104 defines a longitudinal centerline 130 extending in the longitudinal direction L, which is equidistantly positioned in the radial direction R from the inner surface 122 of the root section 104 and the outer end 120 of the root section 104.

[0038] In some embodiments, the root segment 104 may have a dovetail shape. More specifically, as Figure 3 and 5As shown, in these embodiments, when the root segment 104 extends inward along the radial direction R from its outer end 120 to a position 132 located between the inner end 118 and the outer end 120 along the radial direction R, the side surfaces 126, 128 extend outward in the circumferential direction C (i.e., away from the longitudinal centerline 130). Furthermore, when the root segment 104 extends inward along the radial direction R from position 132 to its inner end 118, the side surfaces 126, 128 extend inward in the circumferential direction C (i.e., toward the longitudinal centerline 130). Therefore, the side surfaces 126, 128 can define a V-shaped shape that provides a dovetail structure to the root segment 104. However, in alternative embodiments, the root segment 104 can have any other suitable construction, such as a clip or cedar wood construction.

[0039] In addition, such as Figure 3-5 As shown, one or more metal cables 134 may be coupled to a portion located within the root section 104. Specifically, when the gas turbine engine (e.g., engine 10) has an open rotor configuration, it may be necessary to position one or more metal cables 134 together with the rotor blades 100 of the associated fan section (e.g., fan section 12). Thus, in several embodiments, the metal cables 134 may be partially located within the airfoil section 102 and partially located within the root section 104. For example, each metal cable 134 may extend from a first end 136 located within the root section 104 to a second end (not shown) located within the airfoil section 102. As will be described below, the first end 136 of each metal cable 134 may be coupled to a portion of the root section 104. Furthermore, the metal cables 134 may be formed of any suitable metallic material, such as titanium-based alloys, aluminum-based alloys, or nickel-based alloys.

[0040] Furthermore, the root section 104 includes one or more portions 138 formed of a composite material and one or more portions 140 formed of a metallic material. Specifically, in several embodiments, the composite portion 138 may be positioned between the metallic portions 140. For example, as... Figure 3 and 4As shown, in the illustrated embodiment, the root segment 104 includes a first composite portion 138A, a second composite portion 138B, and a third composite portion 138C, as well as a first metal portion 140A and a second metal portion 140B. In this respect, the first metal portion 140A is positioned along the longitudinal direction L between the first composite portion 138A and the second composite portion 138B. Similarly, the second metal portion 140B is positioned along the longitudinal direction L between the second composite portion 138B and the third composite portion 138C. In this respect, the first composite portion 138A forms the upstream surface 114 of the root segment 104, while the third composite portion 138C forms the downstream surface 116 of the root segment 104. However, in alternative embodiments, the root segment 104 may include any other suitable number of composite portions 138 and / or metal portions 140. Furthermore, the composite portions 138 and / or metal portions 140 may be positioned or arranged within the root segment 104 in any other suitable manner.

[0041] Furthermore, the composite portion 138 of the root segment 104 can be formed of any suitable composite material. For example, the composite material can be selected from, but is not limited to, ceramic matrix composites (CMC), polymer matrix composites (PMC), metal matrix composites (MMC), or combinations thereof. Suitable examples of matrix materials for CMC matrices are ceramic powders, including but not limited to silicon carbide, alumina, silicon oxide, and combinations thereof. Suitable examples of matrix materials for PMCs include, but are not limited to, epoxy-based matrices, polyester-based matrices, and combinations thereof. Suitable examples of MMC matrix materials include, but are not limited to, powdered metals, such as, but not limited to, aluminum or titanium, which can be melted into a continuously molten liquid metal capable of encapsulating fibers present in the component before cooling into a solid ingot with embedded fibers. The resulting MMC is a metal article with increased stiffness, and the metal portion (matrix) is the primary load-carrying element.

[0042] Furthermore, the metal portion 140 of the root section 104 can be formed of any suitable metallic material. In several embodiments, the metal portion can be formed of the same metallic material as the metal cable to facilitate a secure connection between them. For example, the metal portion can be formed of a titanium-based alloy, an aluminum-based alloy, or a nickel-based alloy.

[0043] The root segment 104, formed by one or more composite portions 138 and one or more metallic portions 140, offers various technical advantages. More specifically, as Figure 4As shown, the longitudinal centerline 130 of the root section 104 extends through each metal portion 140. That is, the region of each metal portion 140 is located at the radial center of the root section 104. Furthermore, in several embodiments, a first end 136 of each metal cable 134 is connected to one of the metal portions 140. For example, as... Figure 4 and 5 As shown, in the illustrated embodiment, a first end 136 of one of the metal cables 134 is embedded or otherwise encased within a first metal portion 140A, while a first end 136 of the other metal cable 134 is embedded or otherwise encased within a second metal portion 140B. In this respect, attaching the first end 136 of the metal cable 134 to the metal portion of the root section 104 provides a more secure connection than attaching the cable to a fully composite root section. That is, a metal-to-metal connection is stronger than a metal-to-composite connection. Furthermore, positioning the metal portion at the radial center of the root section further increases the strength of the cable / root connection. Additionally, including a composite portion within the root section 104 (as opposed to a fully metal root section) reduces the weight of the rotor blade 100 and increases the operating temperature range of the rotor blade 100.

[0044] The metal portion 140 of the root segment 104 may be exposed or encapsulated by the composite portion 138. Specifically, in some embodiments, the metal portion 140 may be exposed such that the metal portion 140 forms a region of one or more surfaces of the root segment 104. For example, in Figure 3-5 In the embodiment of the root segment 104 shown, the metal portion 140 forms the region of the inner surface 122, the first side surface 126, and the second side surface 128. In other embodiments, the metal portion 140 may be encapsulated within or otherwise closed by the composite portion 138. In these embodiments, the composite portion 138 forms the entire surface of the root segment 104. For example, in Figure 6 In the embodiment shown, the metal portion 140 is surrounded by the composite portion 138, such that the composite portion 138 defines an upstream surface 114, a downstream surface 116, an inner surface 122, a first side surface 126, and a second side surface 128.

[0045] like Figure 4 and 5 As shown. In several embodiments, the metal portion 140 may be positioned radially inward from the inner end 124 of the airfoil 102. In these embodiments, the metal portion 140 may not extend radially beyond the outer end 120 of the root section 104. However, as Figure 7As shown, in other embodiments, the metal portion 140 may extend in the radial direction R beyond the inner end 124 of the airfoil 102. In such an embodiment, a region of the metal portion 140 may be positioned outward in the radial direction R from the inner end 124 of the airfoil segment 102.

[0046] Furthermore, the composite portion 138 and the metal portion 140 of the root segment 104 can have any suitable cross-sectional shape. Specifically, in several embodiments, the metal portion 140 can have the same cross-sectional shape as the composite portion 138 and / or the entire root segment 104 (i.e., in a plane defined by the radial direction R and the circumferential direction C). For example, in Figure 5 and 6 In the illustrated embodiment, the metal portion 140 has the same dovetail cross-sectional shape as the composite portion 138 and the entire root segment 104. In other embodiments, the metal portion 140 may have a different cross-sectional shape than the composite portion 138 and / or the entire root segment 104 (i.e., in a plane defined by the radial direction R and the circumferential direction C). For example, in Figure 8 In the illustrated embodiment, the metal portion 140 has a rectangular cross-sectional shape, while the composite portion 138 and the entire root section 104 have a dovetail cross-sectional shape.

[0047] This written description uses examples to disclose the invention, including the best mode, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any combined methods. The patentable scope of the invention is defined by the claims, but may include other examples that would occur to those skilled in the art. These other examples are intended to be within the scope of the claims if they include structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not significantly different from the literal language of the claims.

[0048] Other aspects of the invention are provided by the subject matter of the following provisions:

[0049] A rotor blade for a gas turbine engine, characterized in that the rotor blade comprises: an airfoil section; and a root section extending longitudinally between an upstream surface and a downstream surface of the root section, the root section further extending radially between an inner surface located at an inner end of the root section and an outer end connected to the airfoil section, the root section further extending circumferentially between a first side surface and a second side surface, the root section defining a longitudinal centerline extending along the longitudinal direction and equidistantly positioned with respect to the inner surface and the outer end in the radial direction, the root section comprising a first portion formed of a composite material and a second portion formed of a metallic material, wherein the longitudinal centerline extends through the second portion of the root section.

[0050] The rotor blade according to one or more of these provisions further includes: a metal cable, the metal cable being partially located within the airfoil section and partially located within the root section, the metal cable including an end connected to a second portion of the root section.

[0051] Rotor blades according to one or more of these provisions, wherein the end of the metal cable is embedded within the second portion of the root section.

[0052] Rotor blades according to one or more of these provisions, wherein the first portion of the root section forms the upstream surface, the downstream surface, the inner surface, the first side surface, and the second side surface.

[0053] Rotor blades according to one or more of these provisions, wherein the second portion of the root section forms part of at least one of the inner surface, the first side surface, or the second side surface.

[0054] Rotor blades according to one or more of these provisions, wherein the second portion of the root section forms a portion of the inner surface, the first side surface, and the second side surface.

[0055] The rotor blade according to one or more of these provisions, wherein the root section further includes a third portion formed of the metallic material, the third portion of the root section being spaced apart from the second portion of the root section in the longitudinal direction.

[0056] Rotor blades according to one or more of these provisions, wherein the first portion of the root section is positioned along the longitudinal direction between the second portion of the root section and the third portion of the root section.

[0057] The rotor blade according to one or more of these provisions further includes: a first metal cable connected to the second portion of the root section; and a second metal cable connected to the third portion of the root section.

[0058] Rotor blades according to one or more of these provisions, wherein the root section defines a dovetail cross-sectional shape.

[0059] Rotor blades according to one or more of these provisions, wherein the first portion of the root section and the second portion of the root section define the same cross-sectional shape.

[0060] Rotor blades according to one or more of these provisions, wherein the first portion of the root section and the second portion of the root section define different cross-sectional shapes.

[0061] Rotor blades according to one or more of these provisions, wherein the second portion of the root section extends outward along the radial direction beyond the inner end of the airfoil section.

[0062] Rotor blades according to one or more of these provisions, wherein the composite material comprises a ceramic-based composite or a polymer-based composite.

[0063] Rotor blades according to one or more of these provisions, wherein the metallic material includes at least one of titanium, aluminum or nickel.

[0064] A gas turbine engine includes: a fan; a compressor section; a turbine section; and a rotor blade positioned within one of the fan, the compressor section, or the turbine section. The rotor blade includes: an airfoil section; and a root section extending longitudinally between an upstream surface and a downstream surface of the root section. The root section further extends radially between an inner surface located at an inner end of the root section and an outer end connected to the airfoil section. The root section further extends circumferentially between a first side surface and a second side surface. The root section defines a longitudinal centerline extending along the longitudinal direction and equidistantly positioned in the radial direction from the inner surface and the outer end. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, wherein the longitudinal centerline extends through the second portion of the root section.

[0065] The gas turbine engine according to one or more of these provisions further includes: a metal cable, the metal cable being partially located within the airfoil section and partially located within the root section, the metal cable including an end connected to a second portion of the root section.

[0066] A gas turbine engine according to one or more of these provisions, wherein the end of the metal cable is embedded within the second portion of the root section.

[0067] A gas turbine engine according to one or more of these provisions, wherein the first portion of the root section forms the upstream surface, the downstream surface, the inner surface, the first side surface, and the second side surface.

[0068] A gas turbine engine according to one or more of these provisions, wherein the second portion of the root section forms part of at least one of the inner surface, the first side surface, or the second side surface.

Claims

1. A rotor blade for a gas turbine engine, characterized in that, The rotor blades include: Airfoil section; A root section extends longitudinally between an upstream surface and a downstream surface of the root section, and further extends radially between an inner surface located at an inner end of the root section and an outer end connected to the airfoil section. The root section further extends circumferentially between a first side surface and a second side surface. The root section defines a longitudinal centerline extending longitudinally and equidistantly positioned in the radial direction from the inner surface and the outer end. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, the first portion and the second portion being sequentially spaced apart in the longitudinal direction. The first portion forms the upstream surface and the downstream surface, and the first portion and the second portion together form the inner surface, the first side surface, and the second side surface. The longitudinal centerline extends through the second portion of the root section.

2. The rotor blade according to claim 1, characterized in that, Further includes: A metal cable, which is partially located within the airfoil section and partially located within the root section, the metal cable including an end portion connected to a second portion of the root section.

3. The rotor blade according to claim 2, characterized in that, The end of the metal cable is embedded within the second portion of the root section.

4. The rotor blade according to claim 1, characterized in that, The root section defines a dovetail-shaped cross-section.

5. The rotor blade according to claim 1, characterized in that, The first portion and the second portion of the root section define different cross-sectional shapes.

6. The rotor blade according to claim 1, characterized in that, The composite material mentioned above includes ceramic-based composites or polymer-based composites.

7. The rotor blade according to claim 1, characterized in that, The metallic material mentioned herein includes at least one of titanium, aluminum, or nickel.

8. A rotor blade for a gas turbine engine, characterized in that, The rotor blades include: Airfoil section; and A root section extends longitudinally between an upstream surface and a downstream surface of the root section. The root section further extends radially between an inner surface located at an inner end of the root section and an outer end connected to the airfoil section. The root section further extends circumferentially between a first side surface and a second side surface. The root section defines a longitudinal centerline extending along the longitudinal direction and equidistantly positioned in the radial direction from the inner surface and the outer end. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, the first and second portions being sequentially spaced apart in the longitudinal direction. The second portion extends radially outward beyond the inner end of the airfoil section. The longitudinal centerline extends through the second portion of the root section.

9. The rotor blade according to claim 8, characterized in that, Further includes: A metal cable, which is partially located within the airfoil section and partially located within the root section, the metal cable including an end portion connected to a second portion of the root section.

10. The rotor blade according to claim 9, characterized in that, The end of the metal cable is embedded within the second portion of the root section.

11. The rotor blade according to claim 8, characterized in that, The first portion of the root section forms the upstream surface, the downstream surface, the inner surface, the first side surface, and the second side surface.

12. The rotor blade according to claim 8, characterized in that, The first portion and the second portion of the root section define the same cross-sectional shape.

13. The rotor blade according to claim 8, characterized in that, The first portion and the second portion of the root section define different cross-sectional shapes.

14. The rotor blade according to claim 8, characterized in that, The composite material mentioned above includes ceramic-based composites or polymer-based composites.

15. The rotor blade according to claim 8, characterized in that, The metallic material mentioned herein includes at least one of titanium, aluminum, or nickel.

16. A rotor blade for a gas turbine engine, characterized in that, The rotor blades include: Airfoil section; and A root section extends longitudinally between an upstream surface and a downstream surface of the root section. The root section further extends radially between an inner surface located at its inner end and an outer end connected to the airfoil section. The root section further extends circumferentially between a first side surface and a second side surface. The root section defines a longitudinal centerline extending along the longitudinal direction and equidistantly positioned in the radial direction from the inner surface and the outer end. The root section includes a first portion formed of a composite material and a second portion formed of a metallic material, the first and second portions being sequentially spaced apart in the longitudinal direction, and defining the same cross-sectional shape. The longitudinal centerline extends through the second portion of the root section.

17. The rotor blade according to claim 16, characterized in that, Further includes: A metal cable, which is partially located within the airfoil section and partially located within the root section, the metal cable including an end portion connected to a second portion of the root section.

18. The rotor blade according to claim 17, characterized in that, The end of the metal cable is embedded within the second portion of the root section.

Images