Swing hinge for fan blades

Abstract

An engine is provided that defines a longitudinal axis. The engine includes: a turbine; a fan drivenly coupled to the turbine, the fan being a forward thrust fan and having: a hub; a plurality of fan blades, the plurality of fan blades including a first fan blade; and a pivoting hinge integrated into or coupled to the first fan blade, at least a portion of the first fan blade being movable about the pivoting hinge to define a variable angle with respect to the longitudinal axis.

Description

Technical Field

[0001] This disclosure relates to a oscillating hinge for fan blades in a gas turbine engine. Background Technology

[0002] Gas turbine engines typically consist of a turbine and a rotor assembly. Gas turbine engines, such as turbofan engines, are used for aircraft propulsion. In the case of turbofan engines, the rotor assembly can be configured as a fan assembly.

[0003] The fan assembly can be ducted or ductless. Ductless fan assemblies are open to ambient airflow, which may include off-axis airflow due to crosswinds or large angles of attack of the gas turbine engine at low speeds. This can result in asymmetric lift on the fan assembly.

[0004] Improvements that reduce lift asymmetry on fan assemblies would be welcome in the field. Attached Figure Description

[0005] The complete and enabling disclosure of this disclosure, including its best mode, is set forth in the specification with reference to the accompanying drawings, for those skilled in the art, wherein:

[0006] Figure 1 This is a cross-sectional view of a gas turbine engine according to an exemplary aspect of this disclosure.

[0007] Figure 2 Based on exemplary aspects of this disclosure Figure 1 A schematic diagram of a turbine engine and a swing hinge.

[0008] Figure 3 yes Figure 1 Turbo engines and Figure 2 Another schematic diagram of a swing hinge.

[0009] Figure 4 It has Figure 3 A close-up schematic cross-sectional view of the fan blades along the axis of the swing hinge.

[0010] Figure 5 yes Figure 4 A close-up diagram of the fan blades and the oscillating hinge, as shown along... Figure 4 As observed in line 5-5.

[0011] Figure 6 This is a schematic diagram of a swing hinge according to an exemplary aspect of this disclosure.

[0012] Figure 7 This is a schematic diagram of a fan blade according to an exemplary aspect of this disclosure.

[0013] Figure 8Based on exemplary aspects of this disclosure Figure 7 A schematic diagram of an exemplary fan blade and a swing hinge in operation. Detailed Implementation

[0014] Reference will now be made in detail to the present embodiments of this disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerals and letter reference numerals to denote features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to denote similar or analogous portions of this disclosure.

[0015] The term "exemplary" as used herein means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as superior to or beneficial to other implementations. Furthermore, unless specifically stated otherwise, all embodiments described herein should be considered exemplary.

[0016] 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 the individual components.

[0017] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, in the case of a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine nozzle or exhaust port.

[0018] 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, and "downstream" refers to the direction in which the fluid flows.

[0019] Unless otherwise stated herein, the terms “connection”, “attachment”, etc., refer to both direct connection, fixation or attachment and indirect connection, fixation or attachment via one or more intermediate components or features.

[0020] Unless the context clearly indicates otherwise, the singular forms “a,” “one,” and “the” include plural references.

[0021] For example, in the context of "at least one of A, B and C", the term "at least one" means only A, only B, only C, or any combination of A, B and C.

[0022] As used throughout the specification and claims, approximate language is applied to modify any quantitative expression that allows for variation without altering its underlying function. Therefore, values ​​modified by one or more terms such as “approximately,” “about,” and “substantially” are not limited to specified exact values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 1%, 2%, 4%, 10%, 15%, or 20%. These approximate margins may apply to a single value, to either or both endpoints of a defined numerical range, and / or to a margin within a range between endpoints.

[0023] In this specification and throughout the claims, scope limitations are combined and interchanged, and unless the context or language otherwise indicates otherwise, such scope is identified and includes all subscopes contained therein. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0024] As used herein, "third flow" refers to a non-primary airflow capable of increasing fluid energy to generate a small fraction of the total propulsion system thrust. The third flow typically receives inlet air (air from a duct downstream of the main fan) rather than free-flowing air (as with the main fan). The pressure ratio of the third flow can be higher than that of the primary propulsion flow (e.g., bypass or propeller-driven propulsion flow). Thrust can be generated through dedicated nozzles or by mixing the airflow through the third flow with the primary propulsion flow or core airflow, for example, by introducing it into a common nozzle.

[0025] In some exemplary embodiments, the operating temperature of the airflow through the third flow can be below the engine's maximum compressor discharge temperature, and more specifically, below 350 degrees Fahrenheit (e.g., below 300 degrees Fahrenheit, below 250 degrees Fahrenheit, below 200 degrees Fahrenheit, and at least as high as ambient temperature). In some exemplary embodiments, these operating temperatures can facilitate heat transfer to or from the airflow through the third flow and the separate fluid flow. Furthermore, in some exemplary embodiments, the airflow through the third flow can contribute less than 50% of the total engine thrust under takeoff conditions (at least, for example, 2% of the total engine thrust), or more specifically, when operating at rated takeoff power under operating conditions at sea level, static flight speed, and an ambient temperature of 86 degrees Fahrenheit.

[0026] Furthermore, in some exemplary embodiments, the overall system performance can be passively adjusted or purposefully modified during engine operation by means of various aspects of the third flow (e.g., airflow, mixing, or exhaust characteristics) and the aforementioned exemplary percentage of total thrust contribution, in order to adjust or optimize overall system performance under a wide range of potential operating conditions.

[0027] The term "turbine" refers to a machine that includes one or more compressors, a heating section (e.g., a combustion section), and one or more turbines that together produce torque output.

[0028] The term "gas turbine engine" refers to an engine that has a turbine as its power source, either entirely or partially. Examples of gas turbine engines include turbofan engines, turboprop engines, turbojet engines, turboshaft engines, and hybrid electric versions of one or more of these engines.

[0029] The term "combustion section" refers to any heat addition system used in a turbine. For example, the term combustion section may refer to a section including one or more of a knock combustion assembly, a rotating knock combustion assembly, a pulse knock combustion assembly, or other suitable heat addition assembly. In some exemplary embodiments, the combustion section may include an annular burner, a can-shaped burner, a can-annular burner, a vortex burner (TVC), or other suitable combustion systems, or combinations thereof.

[0030] Unless otherwise stated, the terms “low” and “high,” or their respective comparatives (e.g., lower, higher, where applicable), when used with compressors, turbines, shafts, or spool components, refer to relative speeds within an engine. For example, “low turbine” or “low-speed turbine” defines a component configured to operate at a speed (e.g., maximum permissible speed) lower than that of the engine’s “high turbine” or “high-speed turbine.”

[0031] The term "hub" typically refers to the radially inner portion of a fan, including the fan rotor assembly, rotor disc, one or more trunnions, etc.

[0032] As used herein, the terms "monolithic" or "single" to describe a structure refer to a structure formed integrally from a continuous material or group of materials, without seams, joints, etc. The monolithic single structure described herein can be formed to have the structure by additive manufacturing, or alternatively by casting or other processes.

[0033] This disclosure generally relates to a system for accommodating asymmetric disk loads in ductless fans or propellers. More specifically, this disclosure generally relates to a system for incorporating a mechanical oscillating hinge into the fan blades of a gas turbine engine. The ductless fan of a gas turbine engine may be open to ambient airflow. This includes off-axis airflow due to crosswinds or large angles of attack of the gas turbine engine at low spacespeeds. This results in asymmetric lift on the fan assembly of the gas turbine engine and can cause high loads per revolution (“1P load”) in the turbine engine and any mounting structures attached thereto.

[0034] Typically, a mechanical oscillating hinge is provided, which allows the fan blades to move in the axial direction of the turbine engine's travel. This can alter the effective angle of attack of the airflow on the fan blades, thereby reducing lift asymmetry. Furthermore, the mechanical oscillating hinge can allow some of the asymmetric lift to be absorbed by the fan blades themselves as the fan blades move axially.

[0035] In another embodiment, the system may also allow the blades to tilt backward toward or against the nacelle of the gas turbine engine during in-flight shutdown or otherwise when not rotating, thereby reducing frontal area and drag during in-flight shutdown.

[0036] Referring now to the accompanying drawings, where the same numerals indicate the same elements throughout the drawings. Figure 1 This is a schematic diagram of the aircraft's engine 100 (e.g., a turboprop or turbofan). Figure 1 As shown, the engine 100 has a longitudinal axis 112 or axial centerline extending therethrough for reference. The engine 100 also defines an upstream end 114 (or front end) and a downstream end 116 (or rear end) for reference.

[0037] Typically, the axial direction A extends parallel to the longitudinal axis 112, the radial direction R extends outward and inward from the longitudinal axis 112 in a direction orthogonal to the axial direction A, and the circumferential direction C extends 360° around the longitudinal axis 112.

[0038] Engine 100 includes turbine 120. Typically, turbine 120 includes a compressor section, a combustion section, a turbine section, and an exhaust section in a sequential flow order. For example... Figure 1 As shown, turbine 120 includes a core cowling 122 or core duct that defines an annular core inlet 124.

[0039] The core cowling 122 also at least partially encloses the low-pressure system and the high-pressure system. For example, the core cowling 122 shown at least partially encloses and supports a turbocharger or low-pressure (“LP”) compressor 126 for pressurizing air entering the turbine 120 through the core inlet 124. A high-pressure (“HP”), multi-stage, axial compressor 128 receives pressurized air from the LP compressor 126 and further increases the air pressure. The pressurized air flows downstream to the combustor 130 in the combustion section, where fuel is injected into the pressurized air flow and ignited to increase the temperature and energy level of the pressurized air.

[0040] It should be understood that, as used herein, the terms “high / low speed” and “high / low pressure” are used interchangeably with respect to high-pressure / high-speed systems and low-pressure / low-speed systems. Furthermore, it should be understood that the use of the terms “high” and “low” in the same context to distinguish between the two systems does not imply any absolute speed and / or pressure values.

[0041] High-energy combustion products flow downstream from burner 130 to high-pressure turbine 132. High-pressure turbine 132 drives high-pressure compressor 128 via high-pressure shaft 136. In this respect, high-pressure turbine 132 is drivably connected to high-pressure compressor 128.

[0042] The high-energy combustion products then flow to the low-pressure turbine 134. The low-pressure turbine 134 drives components of the low-pressure compressor 126 and the fan section 150 via a low-pressure shaft 138. In this respect, the low-pressure turbine 134 is drivably connected to the components of the low-pressure compressor 126 and the fan section 150. In this example embodiment, the LP shaft 138 is coaxial with the HP shaft 136. After driving each of the turbines 132 and 134, the combustion products exit the turbine 120 through the turbine exhaust nozzle 140.

[0043] The turbine 120 defines a working gas flow path or core duct 142 extending between the core inlet 124 and the turbine exhaust nozzle 140. The core duct 142 is an annular duct generally located inside the core fairing 122 in the radial direction R. The working gas flow path through the core duct 142 of the turbine 120 may be referred to as a second flow.

[0044] The engine includes a rotor assembly, which includes a fan section 150. The fan section 150 includes a fan 152, which is the main fan in this example embodiment. Figure 1 In the illustrated embodiment, fan 152 is an open rotor or ductless fan 152. As shown, fan 152 includes an array of fan blades 154. Figure 1 (Only one is shown in the image). The fan blade 154 is, for example, rotatable about the longitudinal axis 112. As described above, the fan 152 is drivenly connected to the low-pressure turbine 134 via the LP shaft 138.

[0045] The fan 152 can be directly connected to the LP shaft 138 in a direct drive configuration or via a reduction gearbox 155, for example, in an indirect drive or gear drive configuration.

[0046] Each fan blade 154 has a root and a tip, and an airfoil defined therebetween. Each fan blade 154 defines a central blade axis 156. In this embodiment, each fan blade 154 of the fan 152 can rotate about its respective central blade axis 156, for example, in unison with each other. One or more actuators 158 are provided to facilitate this rotation, and are therefore used to change the pitch of the fan blades 154 about their respective central blade axes 156. The one or more actuators 158 may be collectively referred to as a pitch changing mechanism. In some embodiments, the pitch changing mechanism may include a hydraulic actuator (or an electric actuator or a mechanical actuator) that controls the pitch of the fan blades 154.

[0047] Fan section 150 also includes an outlet guide vane array 160, which includes outlet guide vanes (OGV) 162 arranged around a longitudinal axis 112. Figure 1 (Only one is shown in the image) or fan guide vane. Each outlet guide vane 162 has a root and a tip, as well as a span defined between them.

[0048] Each exit guide vane 162 defines a central blade axis 164. In this embodiment, each exit guide vane 162 of the exit guide vane array 160 can rotate about its respective central blade axis 164, for example, in unison with each other. In other embodiments, each exit guide vane 162 of the exit guide vane array 160 can rotate independently about its central blade axis 164 to different degrees. One or more actuators 166 are provided to facilitate this rotation and are therefore used to change the pitch of the exit guide vanes 162 about their respective central blade axes 164.

[0049] The flow path through the outlet guide vane 162 can be referred to as the first flow.

[0050] In addition to the ductless fan 152, a ducted fan or intermediate fan 180 is included behind the fan 152, such that the engine 100 includes both a ducted fan and a ductless fan, both used to generate thrust by moving air through at least a portion of the engine 100. The ducted intermediate fan 180 is shown at approximately the same axial position as the outlet guide vane 162 and radially inside the outlet guide vane 162.

[0051] As shown in the figure, the duct-type intermediate fan 180 includes an array of intermediate fan blades 182. Figure 1(Only one is shown in the image). The fan blades 182 are rotatable, for example, about the longitudinal axis 112. In the depicted embodiment, the ducted fan 180 is driven by a low-pressure turbine 134 (e.g., coupled to the LP shaft 138).

[0052] The fan shroud 190 annularly surrounds at least a portion of the core shroud 122 and is generally positioned radially R outside at least a portion of the core shroud 122. Specifically, a downstream section of the fan shroud 190 extends above the forward portion of the core shroud 122 to define a fan flow path or fan duct 192. The fan flow path or fan duct 192 may be referred to as a third flow of the engine 100. The third flow extends from or along the length of the compressor section to provide a flow path for the rotor assembly above the turbine 120.

[0053] Incoming air enters fan duct 192 through fan duct inlet 196 and exits through fan duct nozzle 198 to generate thrust. Fan duct 192 is an annular duct generally positioned radially R outside core duct 142. The area of ​​fan duct nozzle 198 is variable. For example, fan duct nozzle 198 has a variable area, which is controlled by actuator 199 to change the area of ​​fan duct nozzle 198. The area of ​​fan duct nozzle 198 at least partially determines the thrust through fan duct 192.

[0054] Fan duct 192 includes a fan duct guide vane array 200, which includes fan duct guide vanes 202 disposed around a longitudinal axis 112. Figure 1 (Only one is shown in the image). Each fan duct guide vane 202 has a root and a tip, as well as an airfoil defined between them. The fan duct guide vane array 200 is an array of guide vanes for the fan duct 192, which may also be referred to as a third flow. In alternative embodiments, such as a dual-flow engine architecture, the fan duct 192 is omitted.

[0055] The fan shroud 190 and the core shroud 122 may be supported by a plurality of substantially radially extending, circumferentially spaced fixed struts. Figure 1 (Not shown) Connections and supports. Each of the fixed struts may have an aerodynamic profile to guide airflow therefrom. Other struts besides the fixed struts may be used to connect and support the fan fairing 190 and / or the core fairing 122.

[0056] The fan duct 192 and the core duct 142 may extend at least partially together (generally axially) on opposite sides (e.g., opposite radial sides) of the core fairing 122. For example, the fan duct 192 and the core duct 142 may each extend directly from the leading edge 194 of the core fairing 122 and may extend generally axially and partially together on opposite radial sides of the core fairing 122.

[0057] Engine 100 also defines or includes inlet duct 210. Inlet duct 210 extends between engine inlet 212 and core inlet 124 / fan duct inlet 196. Engine inlet 212 is generally defined at the front end of fan cowl 190. Inlet duct 210 is an annular duct located radially R inside fan cowl 190.

[0058] The air flowing downstream along inlet duct 210 is diverted by the splitter or the leading edge 194 of the core fairing 122 into the core duct 142 and fan duct 192, and is not necessarily uniform. Inlet duct 210 is wider than core duct 142 in the radial direction R. Inlet duct 210 is also wider than fan duct 192 in the radial direction R.

[0059] In an exemplary embodiment, the air passing through fan duct 192 may be relatively cold (e.g., at a lower temperature) than one or more fluids used in turbine 120. In this way, one or more heat exchangers may be disposed within fan duct 192 and used to cool one or more fluids from the core engine, wherein air passes through fan duct 192 as a resource for removing heat from fluids (e.g., compressor bleed air, oil, or fuel). By positioning fan duct inlet 196 downstream of fan duct 180 in fan duct 192 (such that the airflow through fan duct 192 is a pressurized airflow from fan 180), during engine 100 operation, the airflow through fan duct 192 may have sufficient pressure such that the pressure drop experienced by the airflow at such one or more heat exchangers in fan duct 192 may not prevent the airflow from providing the desired thrust to engine 100 as it exits through fan duct nozzle 198.

[0060] Although not depicted, in some exemplary embodiments, engine 100 may also include one or more heat exchangers in other annular ducts or flow paths of engine 100 (e.g., in inlet duct 210, in turbine flow path or core duct 142, in turbine section and / or turbine exhaust nozzle 140, etc.).

[0061] Inlet pipe 210 includes an inlet guide vane array 220, which includes inlet guide vanes 222 arranged around longitudinal axis 112. Figure 1(Only one is shown in the image). Each inlet guide vane 222 has a root and a tip, as well as a span defined between them. The inlet guide vane array 220 is a guide vane array for the inlet pipe 210.

[0062] Each inlet guide vane 222 defines a central blade axis 224. In this embodiment, each inlet guide vane 222 of the inlet guide vane array 220 can rotate about its respective central blade axis 164, for example, in unison with each other. One or more actuators 226 are provided to facilitate this rotation and are therefore used to change the pitch of the inlet guide vanes 222 about their respective central blade axes 224.

[0063] It should be understood that Figure 1 The exemplary engine 100 depicted is merely an example, and in other exemplary embodiments, engine 100 may have any other suitable configuration. For example, aspects of this disclosure can be used with any other suitable aviation gas turbine engine (e.g., turboshaft engine, turboprop engine, turbojet engine, etc.). Furthermore, aspects of this disclosure can also be used with any aero-derivative gas turbine engine (e.g., marine gas turbine engine).

[0064] Other gas turbine engines to which this disclosure is applicable may have alternative configurations. For example, such engines may have an alternative number of interconnecting shafts (e.g., two) and / or an alternative number of compressors and / or turbines. Furthermore, the engine may exclude a gearbox disposed in the drivetrain from the turbine to the compressor and / or fan, may be configured as a dual-flow gas turbine engine (e.g., excluding fan duct 192), may exclude intermediate fan 180, etc.

[0065] Furthermore, it should be understood that other engine configurations may also be used in other exemplary embodiments of this disclosure. For example, in other exemplary embodiments of this disclosure, the duct-type fan 180 may be configured as part of a "fan on blades" configuration, wherein fan blades 182 are mounted to or extend from internal compressor blades (e.g., from internal low-pressure compressor or turbocharger rotor blades).

[0066] Now for reference Figure 2 and Figure 3 Provided Figure 1 A schematic diagram of an exemplary gas turbine engine 100. More specifically, Figure 2 The exemplary aspect of this disclosure includes a swing hinge 300. Figure 1 A schematic diagram of the fan blades 154 of the fan 152 of an exemplary gas turbine engine 100, as observed along the radial direction R of the gas turbine engine 100. Figure 3It is observed along the axial direction A of the gas turbine engine 100. Figure 1 A schematic diagram of the fan blade 154 and the gas turbine engine 100.

[0067] In this way, it should be understood that fan 152 ( Figure 1 (As shown) may be a forward thrust fan and includes a plurality of fan blades 154 and a hub 106 rotatable together with the plurality of fan blades 154. For clarity, Figure 2 and Figure 3 Only one of the multiple fan blades 154 is depicted in the text and is described in more detail below; similarly, Figure 2 and Figure 3 The image depicts a single swing hinge 300.

[0068] A gas turbine engine 100 defines a longitudinal axis 112 and includes a turbine 120 and a fan section 150 drivably coupled to the turbine 120. The fan 152 is a forward thrust fan and includes a hub 106, fan blades 154, and a pivot hinge 300. The pivot hinge 300 is integrated into or coupled to the fan blades 154. As described above, Figure 2 and Figure 3 The image depicts a single swing hinge 300 and fan blades 154. However, it should be understood that multiple fan blades 154 (see [reference needed]) are also present. Figure 1 Each of the following can include a swing hinge 300, which is integrated into or connected to the corresponding fan blade 154.

[0069] As will be discussed in more detail below, at least a portion of the fan blade 154 is movable about the oscillating hinge 300 to define a variable angle with respect to the longitudinal axis 112. In this way, the oscillating hinge 300 allows the fan blade 154 to adapt to asymmetrical disk loads of the fan section 150 and also helps to counteract asymmetrical lift encountered during forward travel. This mechanical structure incorporated into the fan blade 154 allows the fan blade 154 to move in the axial direction A (e.g., along the direction of travel; see details). Figure 3 It oscillates, and as will be discussed in more detail below, in the circumferential direction C (e.g., opposite to the direction of rotation; see details). Figure 2 The hinge 300 swings on the fan blades. This swing hinge 300 can reduce the load on the fan blades 154 by 1P.

[0070] As briefly noted above, the swing hinge 300 is integrated into or attached to the fan blade 154, which allows the fan blade 154 to be in a fully extended position and a fully swing position (in Figure 2 and Figure 3The fan blades 154 (represented by dashed lines) oscillate in the axial direction A and the circumferential direction C. Figure 3 As shown, the circumferential portion of the fan blade 154 that moves is as follows: Figure 2 As shown. In this way, it will be understood that at least a portion of the fan blade 154 is movable about the oscillating hinge 300 to define a variable oscillating hinge angle 302 relative to the longitudinal axis 112. The oscillating hinge angle 302 can vary between approximately 90 degrees (fully extended) and approximately 45 degrees (fully oscillating) or any other suitable angle in between. It is worth noting that both centrifugal force and drag force tend to pull the fan blade 154 toward its fully extended (normal operating) position.

[0071] Furthermore, it should be understood that, Figure 2 and Figure 3 In one embodiment, the oscillating hinge 300 is integrated into the fan blade 154 such that the fan blade 154 defines an outer portion 304 radially R outside the oscillating hinge 300 and an inner portion 306 radially R inside the oscillating hinge 300. The fan blade 154 also defines a leading edge 308 and a trailing edge 310. The oscillating hinge 300 also defines an oscillating hinge axis 312 (see...). Figure 4 and 5 The outer portion 304 can rotate relative to the inner portion 306 about the pivot hinge axis 312.

[0072] In the illustrated embodiment, the outer portion 304 constitutes at least 80%, for example at least about 85%, or for example at least about 90%, of the span of the fan blade 154. In other embodiments, the swing hinge 300 may be further positioned in the radial direction R such that the fan blade 154 is engaged with the swing hinge.

[0073] from Figure 2 and Figure 3 It can be understood that the pivot hinge axis 312 extends from the leading edge 308 to the trailing edge 310. More specifically, Figure 4 A close-up schematic cross-sectional view of a fan blade 154 with a swing hinge axis 312 is provided. Figure 4 It is along Figure 3Viewed from line 4-4, i.e., looking inward along the radial direction R. As shown, the pivot hinge axis 312 extends from the leading edge 308 to the trailing edge 310, and the outer portion 304 defines a rotational direction 314 about the pivot hinge axis 312. As noted, the pivot hinge axis 312 defines a first angle 316 with the longitudinal axis 112 (and more specifically with the plane 318 defined by the longitudinal axis 112 and the radial direction R), which is between 0 degrees and 180 degrees, for example between 10 degrees and 85 degrees, for example between 15 degrees and 75 degrees. In this way, the rotational direction 314 is not parallel to the longitudinal axis 112 of the gas turbine engine 100, but is defined with the longitudinal axis 112 at an angle that can be approximately equal to the first angle 316.

[0074] In addition, it is now also referenced Figure 5 Provided Figure 4 A close-up illustration of fan blade 154, as shown along... Figure 4 As observed in line 5-5. Figure 5 The view may be referred to as a plan view of one side of the fan blade 154 (e.g., the suction side of the fan blade 154). As noted, the pivot hinge axis 312 extends from the leading edge 308 of the fan blade 154 to the trailing edge 310. However, it should also be understood that the pivot hinge axis 312 also defines a second angle 320 with the longitudinal axis 112 (and more specifically, with the plane 322 defined by the tangent of the pivot hinge axis 312 to the leading edge 308 of the fan blade 154 and the circumferential direction C at the intersection of the axial direction A and the longitudinal axis 112). The second angle 320 may be greater than 0 degrees and less than 90 degrees, for example, between approximately 5 degrees and 45 degrees. In this way, it should be understood that when the fan blade 154 pivots backward about the pivot hinge axis 312 in the direction of rotation 314, the angle of attack of the fan blade 154 changes, the pitch effectively decreases as the fan blade 154 moves forward in the direction of rotation 314, and the pitch effectively increases as the fan blade 154 moves backward in the direction of rotation 314.

[0075] Now for reference Figure 6 According to an exemplary aspect of this disclosure, a schematic diagram of a swing hinge 300 integrated into a fan blade 154 is provided. The swing hinge 300 may be incorporated into the foregoing reference. Figures 1 to 5 In one or more of the gas turbine engine 100, fan 152 and / or fan blades 154 described.

[0076] In the illustrated embodiment, the fan blade 154 includes an outer portion 304 in the radial direction R and an inner portion 306 in the radial direction R. A pivot hinge 300 is integrated into the fan blade 154 between the outer portion 304 and the inner portion 306. The pivot hinge 300 includes a roller bearing 324, a thrust bearing 326, and a hinge axis 328. The pivot hinge 300, and more specifically the hinge axis 328, defines a pivot hinge axis 312. In particular, the roller bearing 324 and the thrust bearing 326 facilitate rotation of the outer portion 304 of the fan blade 154 relative to the inner portion 306 of the fan blade 154 about the pivot hinge axis 312. More specifically, the bearings 324 and 326 facilitate rotation of the inner portion 306 and the outer portion 304 of the fan blade 154 about the hinge axis 328.

[0077] The oscillating hinge 300 may also include a biasing member 330. The biasing member 330 may be an elastomer or a mechanical spring, positioned to bias the fan blades 154 toward a fully extended position, for example, when the fan 152 is stopped or during engine startup. However, the biasing member 330 still allows the fan blades 154 to move toward an oscillating position (e.g., rearward tapering) when the aircraft is stopped in flight. The relatively simple oscillating hinge 300 (which includes a single axis of rotation) ensures that the fan blades 154 do not contact each other and will follow a specific arc in their movement.

[0078] In other embodiments, the swing hinge 300 can be configured as any other suitable hinge, such as a piano hinge. Regarding the piano hinge, it can be a continuous hinge that is substantially straight and sized to extend substantially the entire length of the connected components (e.g., outer portion 304 and inner portion 306).

[0079] The relatively simple design of the oscillating hinge 300 offers several advantages. For example, because there is an oscillating hinge 300 on each fan blade 154, they are easily accessible and can be maintained independently. Additionally, the oscillating hinge 300 has relatively small movement and may not require cooling or oil flow. Furthermore, the oscillating hinge 300 may not require any sensors or rapidly moving actuators on the rotating fan blade 154.

[0080] Using one or more of the exemplary swing hinges 300 of this disclosure with the fan blades 154 of the fan 152 of this disclosure can allow for higher rotational speeds of the fan 152 because the load on the fan 152 can be reduced. For example, the fan blades 154 can be configured to rotate at speeds between approximately 800 revolutions per minute (“rpm”) and approximately 4,000 rpm.

[0081] Brief Review Figure 1In some embodiments, the gas turbine engine 100 may also include a pitch actuation system for changing the pitch of the fan blades 154 of the fan 152. The pitch actuation system rotates the fan blades 154 to change the pitch of the fan blades 154 independently of the oscillating hinge 300. However, based on the configuration of the oscillating hinge 300 and the oscillating hinge axis 312, rotation of the outer portion 304 of the fan blades 154 about the oscillating hinge axis 312 may also allow for a change in the effective pitch angle of the fan blades 154. For example, in at least some exemplary aspects, for every 1 degree of rotation about the oscillating hinge axis 312, the fan blades 154 themselves may have a 1-degree pitch change. In this way, when the fan blades 154 are in the fully extended position, they can be fully feathered to resist the incoming airflow.

[0082] Now for reference Figure 7 and Figure 8 The operation of the fan blades 154, including the swing hinge 300, will be described in more detail. Figure 7 A schematic diagram of a fan blade 154 is provided, which can move about a pivot hinge 300 (not shown) between an extended position and a feathering position (dashed line). Figure 8 The effect of the fan blades 154 feathering during operation with a non-uniform inlet airflow 350 is shown by the circumferential rotation of the fan blades 154.

[0083] First refer to Figure 7 It should be understood that as the fan blades 154 feather, the effective pitch angle of the fan blades 154 increases, which changes the relative angle of attack of the inlet airflow 350, and also changes the lift (and thus the thrust) generated by the fan blades 154.

[0084] Now for reference Figure 8 The fan blades 154 are depicted at four different positions in the plane of rotation (shown view); a first position 352, a second position 354 (1 / 4 rotation), a third position 356 (1 / 2 rotation), and a fourth position 358 (3 / 4 rotation). As noted, the oscillating hinge 300 is angled relative to this plane of rotation to allow the above-mentioned... Figure 7 The operation indicated.

[0085] A vector diagram is provided at each of these locations, showing the direction of rotation of the fan blade 154 (vector line 360) and the direction of the inlet airflow 350 on the fan blade 154 (vector line 362; see...). Figure 7 The movement of the element 350 and the fan blade 154 via the swing hinge 300 (vector line 364). Figure 8The graphical description in the figure represents crossflow operating conditions (e.g., low forward speed and high crosswind). With this configuration, at the first position 352 and the third position 356, the inlet airflow experienced by the fan blades 154 is relative to the axial direction.

[0086] At the second position 354, fan blade 154 is descending, allowing it to effectively experience a higher airspeed. Fan blade 154 rotates rearward about the pivot hinge axis 312, effectively reducing the angle of attack of fan blade 154 to ensure uniform force distribution around fan 152. Similarly, at the fourth position 358, fan blade 154 is ascending. As fan blade 154 rotates upward, it encounters a lower airspeed. However, the reduction in lift is offset by the oscillating motion at the second position 354, which is opposite to the aforementioned oscillating motion, effectively increasing the angle of attack of fan blade 154 to ensure uniform force distribution around fan 152.

[0087] It is worth noting that at each of these positions, the physical fan blade root pitch is constant, but the effective angle of attack changes due to the oscillating motion.

[0088] Furthermore, it should be understood that when the fan blade 154 rotates, the thrust that pulls the blade backward is offset by the centrifugal force that pulls the fan blade 154 radially out of the hub and the drag force that pulls the fan blade 154 tangentially backward in its rotational direction to the fully extended position.

[0089] Furthermore, it should be understood that when the fan blades 154 are not rotating, aerodynamics can push the fan blades 154 back, including the fan blades 154 (see [link to article]). Figure 1 The nacelle of the gas turbine engine is designed to reduce its frontal area and drag. Centrifugal and drag forces on the fan blades 154 are balanced with thrust, forming a natural damping system. Thrust is balanced by centrifugal force, allowing the fan blades 154 to float and providing natural damping for asymmetric forces.

[0090] It should be understood that, in some embodiments, the fan according to embodiments of the present disclosure may include a plurality of oscillating hinges and a plurality of fan blades, wherein each oscillating hinge is coupled to or integrated into a corresponding fan blade among the plurality of fan blades. The oscillating hinges may allow movement of the fan blades in the axial direction A, which can reduce lift asymmetry by changing the effective angle of attack on the fan blades. The oscillating hinges also allow some of the asymmetric lift to be absorbed by the inertia of the fan blades themselves during axial movement. Optionally, the oscillating hinges may also allow the fan blades to rest rearward against the nacelle when not rotating, thereby reducing frontal area and drag during in-flight shutdowns.

[0091] Furthermore, it includes multiple oscillating hinges, each of which is connected to or integrated into a corresponding fan blade among multiple fan blades, allowing each corresponding fan blade to fully extend as it rotates about its respective oscillating hinge axis. Thus, when the fan blades are fully rotated about their respective oscillating hinge axes, their fan blades can be fully feathered. The maximum angle at which the fan blades can feather (also known as the "cone") can be determined by the oscillating hinge angle relative to the longitudinal axis (see [reference]). Figure 3 This is determined by [the specific mechanism]. At maximum rearward deflection, the fan blade pitch has changed, making it fully feathered. When using an angled oscillating hinge, the fan blades are fully feathered without additional actuation.

[0092] As will be further understood, although the inclusion of a swaying hinge can provide natural feathering of the fan blades at relatively low speeds and in flight when the fan blades are not rotating, this may not negatively impact the thrust of the gas turbine engine, as drag and centrifugal forces would likely pull the fan blades out to full extension when the fan is rotating at relatively high speeds. Therefore, when the gas turbine engine is operating at relatively high speeds, the fan blades will remain fully extended, and the angle of attack will ultimately not change.

[0093] This written description uses examples to disclose this disclosure, including best practices, and also enables any person skilled in the art to practice this disclosure, including making and using any apparatus or system and performing any incorporated methods. The patentable scope of this disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such 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 substantially different from the literal language of the claims.

[0094] Further aspects are provided by the following topics:

[0095] An engine defining a longitudinal axis includes: a turbine; a fan drivenly coupled to the turbine, the fan being a forward thrust fan and including: a hub; a plurality of fan blades, the plurality of fan blades including a first fan blade; and a pivoting hinge integrated into or coupled to the first fan blade, at least a portion of the first fan blade being movable about the pivoting hinge to define a variable angle with respect to the longitudinal axis.

[0096] According to any of the foregoing clauses, the variable angle is between approximately 90 degrees and approximately 45 degrees.

[0097] According to any of the foregoing clauses, the oscillating hinge is integrated into the first fan blade.

[0098] According to any of the preceding clauses of the engine, wherein the first fan blade includes an outer portion and an inner portion, wherein the outer portion is rotatable relative to the inner portion about the oscillating hinge.

[0099] According to any of the preceding clauses of the engine, wherein the oscillating hinge includes a biasing member positioned to bias the oscillating hinge toward a fully extended position.

[0100] According to any of the foregoing clauses, the plurality of blades are configured to rotate at a speed between approximately 800 rpm and approximately 4000 rpm.

[0101] The engine according to any of the foregoing clauses further includes a plurality of oscillating hinges, wherein the oscillating hinge is a first oscillating hinge of the plurality of oscillating hinges, and wherein each of the plurality of fan blades includes at least one portion that is movable about a corresponding one of the plurality of oscillating hinges to define a variable angle with respect to the longitudinal axis.

[0102] According to any of the preceding clauses, the oscillating hinge defines an oscillating hinge axis, and the oscillating hinge axis defines an angle greater than 0 with a plane defined by the longitudinal axis and the radial direction of the engine.

[0103] According to any of the preceding clauses of the engine, wherein the swing hinge defines a swing hinge axis, and wherein the swing hinge axis defines an angle greater than 0 with a plane defined by the tangent in the circumferential direction at the intersection of the longitudinal axis and the swing hinge axis with the leading edge of the first fan blade.

[0104] According to any of the preceding clauses, the oscillating hinge includes a hinge axis defining the axis of the oscillating hinge.

[0105] The engine described in any of the foregoing clauses is a turbofan engine.

[0106] According to any of the foregoing clauses, the fan is a ductless fan.

[0107] The engine according to any of the foregoing clauses further includes: a pitch actuation system, wherein the first fan blade defines a pitch, and wherein the pitch actuation system rotates the first fan blade to change the pitch of the first fan blade independently of the oscillating hinge.

[0108] A fan blade for a fan of an engine defining a longitudinal axis, the fan blade comprising: an airfoil portion configured to rotate about the longitudinal axis to generate thrust during operation of the engine; and a pivot hinge integrated into or coupled to the airfoil portion, at least a portion of the airfoil portion being movable about the pivot hinge to define a variable angle with the longitudinal axis during operation of the engine.

[0109] The fan blades according to any of the foregoing clauses, wherein the variable angle is between approximately 90 degrees and approximately 45 degrees.

[0110] Fan blades according to any of the foregoing clauses, wherein the oscillating hinge is integrated into the airfoil portion of the fan blade.

[0111] A fan blade according to any of the foregoing clauses, wherein the airfoil portion of the fan blade comprises an outer portion and an inner portion, wherein the outer portion is rotatable relative to the inner portion about the oscillating hinge.

[0112] According to any of the preceding clauses, the fan blade, wherein the oscillating hinge includes a biasing member positioned to bias the oscillating hinge toward a fully extended position.

[0113] The fan blade according to any of the foregoing clauses, wherein the oscillating hinge includes a hinge axis defining the axis of the oscillating hinge.

[0114] According to any of the preceding clauses, the fan blade, wherein the oscillating hinge defines an oscillating hinge axis, and wherein the oscillating hinge axis defines an angle greater than 0 with a plane defined by the tangent in the circumferential direction at the intersection of the longitudinal axis and the oscillating hinge axis with the leading edge of the first fan blade.

Claims

1. An engine defining a longitudinal axis and having an axial direction extending parallel to said longitudinal axis, characterized in that, include: Turbine; A fan, the fan being driven and coupled to the turbine, the fan being a forward thrust fan and comprising: Wheel hub; Multiple fan blades, said multiple fan blades including a first fan blade; and A swing hinge, which is integrated into or connected to the first fan blade, at least a portion of the first fan blade being movable about the swing hinge to define a variable angle with respect to the longitudinal axis; The swing hinge defines a swing hinge axis, and the swing hinge axis defines an angle greater than 0 with the plane, wherein the plane is defined by the axial direction and the tangent in the circumferential direction at the intersection of the swing hinge axis and the leading edge of the first fan blade.

2. The engine according to claim 1, characterized in that, The variable angle is between 90 degrees and 45 degrees.

3. The engine according to claim 1, characterized in that, The swing hinge is integrated into the first fan blade.

4. The engine according to claim 3, characterized in that, The first fan blade includes an outer portion and an inner portion, wherein the outer portion is rotatable relative to the inner portion about the oscillating hinge.

5. The engine according to claim 1, characterized in that, The oscillating hinge includes a biasing member positioned to bias the oscillating hinge toward a fully extended position.

6. The engine according to claim 1, characterized in that, The plurality of blades are configured to rotate at speeds between 800 rpm and 4000 rpm.

7. The engine according to claim 1, characterized in that, It further includes a plurality of oscillating hinges, wherein the oscillating hinge is a first oscillating hinge of the plurality of oscillating hinges, and wherein each of the plurality of fan blades includes at least one portion that is movable about a corresponding one of the plurality of oscillating hinges to define a variable angle with respect to the longitudinal axis.

8. The engine according to claim 1, characterized in that, The swing hinge defines a swing hinge axis, and the swing hinge axis defines an angle greater than 0 with a plane defined by the longitudinal axis and the radial direction of the engine.

9. The engine according to claim 1, characterized in that, The swing hinge includes a hinge axis that defines the axis of the swing hinge.

10. The engine according to claim 1, characterized in that, The engine mentioned is a turbofan engine.

11. The engine according to claim 1, characterized in that, The fan mentioned is a ductless fan.

12. The engine according to claim 1, characterized in that, Further includes: A pitch actuation system, wherein the first fan blade defines the pitch, and wherein the pitch actuation system rotates the first fan blade to change the pitch of the first fan blade independently of the oscillating hinge.

13. A fan blade for a fan in a turbine engine, the turbine engine defining a longitudinal axis and having an axial direction extending parallel to the longitudinal axis, characterized in that, The fan blades include: Airfoil portion, the airfoil portion being rotatable about the longitudinal axis to generate thrust during operation of the turbine engine; and A swing hinge, which is integrated into or connected to the airfoil portion, at least a portion of the airfoil portion being movable about the swing hinge to define a variable angle with the longitudinal axis during operation of the turbine engine; The swing hinge defines a swing hinge axis, and the swing hinge axis defines an angle greater than 0 with the plane, wherein the plane is defined by the axial direction and the tangent in the circumferential direction at the intersection of the swing hinge axis and the leading edge of the fan blade.

14. The fan blade according to claim 13, characterized in that, The variable angle is between 90 degrees and 45 degrees.

15. The fan blade according to claim 13, characterized in that, The swing hinge is integrated into the airfoil portion of the fan blade.

16. The fan blade according to claim 15, characterized in that, The airfoil portion of the fan blade includes an outer portion and an inner portion, wherein the outer portion is rotatable relative to the inner portion about the oscillating hinge.

17. The fan blade according to claim 13, characterized in that, The oscillating hinge includes a biasing member positioned to bias the oscillating hinge toward a fully extended position.

18. The fan blade according to claim 13, characterized in that, The swing hinge includes a hinge axis that defines the axis of the swing hinge.

Images