Fan assembly for engine with redundant trunnion retention

Abstract

A fan assembly for an engine has fan blades, a disk having a disk segment, a trunnion mechanism having a trunnion at least partially passing through the disk segment, and first and second attachment systems. The trunnion has a platform and a shaft. The fan blades are adjacent to the platform of the trunnion. The trunnion is attached to the disk segment along a preload path using a first attachment system. The first and second attachment systems also include first and second retention features separate from the preload path, respectively. During normal operation of the fan assembly, the first attachment system retains the trunnion within the disk along the first load path. When the trunnion fails, the first and second retention features together retain the trunnion within the disk section along a second load path, the first load path being different than the second load path.

Description

Technical Field

[0001] The present disclosure relates generally to a fan assembly for a gas turbine engine and, more particularly, to a redundant fan blade retention feature for a fan assembly for a gas turbine engine. Background Art

[0002] A gas turbine engine typically includes a fan section and a core arranged to be in flow communication with each other. The core of a gas turbine engine typically includes a compressor section, a combustion section, a turbine section, and an exhaust section in a serial flow order. In operation, an air flow is provided from a fan to the inlet of the compressor section, where one or more axial compressors gradually compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned in the combustion section to provide combustion gases. The combustion gases are directed from the combustion section to the turbine section. The flow of combustion gases passing through the combustion section drives the combustion section and is then directed through the exhaust section to, for example, the atmosphere. In a specific configuration, the turbine section is mechanically coupled to the compressor section by a shaft extending in the axial direction of the gas turbine engine.

[0003] The fan section includes a fan assembly having a plurality of fan blades having a radius greater than the core of the gas turbine engine. The plurality of fan blades are typically driven by a shaft. Each of the plurality of blades may be attached to a trunnion mechanism, which in turn is attached to a disk. The trunnion mechanism is capable of rotating relative to the disk to allow the pitch of the plurality of fan blades to be changed. Thus, the trunnion mechanism may be attached to the disk using a variety of bearings and other accompanying structures.

[0004] In order to improve the safety of the gas turbine engine, the components downstream of the fan section are designed to take into account the possibility that the attachment system that attaches the trunnion to the disk may fail. However, such a configuration can reduce the efficiency of the gas turbine engine. For example, the increased armor weight added to the fuselage of the gas turbine engine can reduce the efficiency of the gas turbine engine.

[0005] Therefore, it would be beneficial to have a fan assembly for a gas turbine engine having one or more features to retain the trunnion and the fan blades attached thereto to the disk in the event of a failure of the attachment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A complete and enabling disclosure for one of ordinary skill in the art is set forth in the specification, which refers to the accompanying drawings, in which:

[0007] Figure 1 is a schematic cross-sectional view of a gas turbine engine with an unducted fan according to an embodiment of the present disclosure.

[0008] Figure 2is a perspective view of a variable pitch fan of a gas turbine engine according to an embodiment of the present disclosure.

[0009] Figure 3 An exploded perspective view of a portion of a fan assembly of a gas turbine engine, particularly illustrating a disk segment, a trunnion mechanism, and a first attachment system and a second attachment system according to an embodiment of the present disclosure.

[0010] Figure 4 yes Figure 3 A stereogram of the disc segment and trunnion mechanism.

[0011] Figure 5 yes Figure 3 A side cross-sectional view of the disc segment and trunnion mechanism.

[0012] Figure 6 yes Figure 5 A top view of a segmented insert of a fan assembly.

[0013] Figure 7 A side cross-sectional view of a portion of a fan assembly of a gas turbine engine, particularly illustrating a disk segment, a trunnion mechanism, and first and second attachment systems according to an embodiment of the present disclosure.

[0014] Figure 8 A side cross-sectional view of a portion of a fan assembly of a gas turbine engine, particularly illustrating a disk segment, a trunnion mechanism, and first and second attachment systems according to an embodiment of the present disclosure.

[0015] Fig. 9 yes Figure 8 A top view of a portion of a fan assembly, particularly showing the disc segment and the first insert.

[0016] Fig.10 A side cross-sectional view of a portion of a fan assembly of a gas turbine engine, particularly illustrating a disk segment, a trunnion mechanism, and first and second attachment systems according to an embodiment of the present disclosure.

[0017] Fig.11 yes Fig.10 A top view of a portion of a fan assembly, particularly showing the disc segment and the first insert.

[0018] Fig.12 A side cross-sectional view of a portion of a fan assembly of a gas turbine engine, particularly illustrating a disk segment, a trunnion mechanism, and first and second attachment systems according to an embodiment of the present disclosure.

[0019] Fig.13A side cross-sectional view of a portion of a fan assembly of a gas turbine engine, particularly illustrating a disk segment, a trunnion mechanism, and first and second attachment systems according to an embodiment of the present disclosure.

[0020] Fig.14 A block diagram illustrating components that may be included in a controller according to an embodiment of the present disclosure.

[0021] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present disclosure. DETAILED DESCRIPTION

[0022] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. Each example is provided in an explanation of the present disclosure, rather than limiting the present disclosure. In fact, it will be appreciated by those skilled in the art that various modifications and variations may be made to the present disclosure without departing from the scope or spirit of the present disclosure. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to encompass such modifications and variations within the scope of the appended claims and their equivalents.

[0023] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0024] For example, the term "at least one of" in the context of "at least one of A, B, or C" means only A, only B, only C, or any combination of A, B, and C.

[0025] The term “turbomachine” refers to a machine that includes one or more compressors, a heat generating section (eg, a combustion section), and one or more turbines that together produce a torque output.

[0026] The term "gas turbine engine" refers to an engine having a turbine as all or part of its power source. Example gas turbine engines that may be used in the present disclosure include unducted turbofan engines, ducted turbofan engines, and / or turboprop engines.

[0027] The term "combustion section" refers to any heat addition system of a turbomachine. For example, the term combustion section may refer to a section that includes one or more of a deflagration combustion assembly, a rotating detonation combustion assembly, a pulse detonation combustion assembly, or other suitable heat addition assemblies. In certain example embodiments, the combustion section may include an annular combustor, a can combustor, a tubular combustor, a trapped vortex combustor (TVC), or other suitable combustion systems, or combinations thereof.

[0028] As used herein, the term "rotor" refers to any component of a rotating machine (eg, a turbine engine) that rotates about an axis of rotation. For example, the rotor may include a shaft or spool of a rotating machine (eg, a turbine engine).

[0029] As used herein, the term "stator" refers to any component of a rotating machine (e.g., a turbine engine) having a configuration and arrangement coaxial with a rotor of the rotating machine. The stator may be arranged radially inward or radially outward along a radial axis relative to at least a portion of the rotor. Additionally or alternatively, the stator may be axially arranged adjacent to at least a portion of the rotor.

[0030] The terms "low" and "high" or their respective comparatives (e.g., lower, higher, where applicable), when used with a compressor, turbine, shaft or spool component, etc., refer to relative speeds within an engine unless otherwise indicated. For example, a "low turbine" or "low-speed turbine" defines a component that is configured to operate at a lower speed (e.g., maximum allowable speed) than a "high turbine" or "high-speed turbine" of the engine.

[0031] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0032] The terms "upstream" and "downstream" refer to relative directions with respect to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, while "downstream" refers to the direction to which the fluid is flowing.

[0033] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the centerline of the gas turbine engine. Additionally, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the centerline of the gas turbine engine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations extending in an arc around the centerline of the gas turbine engine.

[0034] The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attachment as well as indirect coupling, fixing, or attachment through one or more intermediate components or features, unless otherwise specified herein.

[0035] As used herein, the terms "first," "second," "third," etc. may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of each component.

[0036] The term "adjacent" as used herein with respect to two walls and / or surfaces means that the two walls and / or surfaces are in contact with each other, or that the two walls and / or surfaces are separated only by one or more non-structural layers, and the two walls and / or surfaces are in a series contact relationship with the one or more non-structural layers (i.e., a first wall / surface contacts the one or more non-structural layers, and the one or more non-structural layers contacts the second wall / surface).

[0037] As used herein, the term "integral" or "unitary" used to describe a structure refers to a structure formed integrally from a continuous material or group of materials without seams, connecting joints, etc. The integral, unitary structures described herein can be formed by additive manufacturing to have the structure, or formed by a casting process, etc.

[0038] Here and throughout the specification and claims, range limitations are combined and interchanged, and these ranges are identified and include all sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints are independently combinable with each other.

[0039] In general, the present disclosure relates to a fan assembly having a redundant / fail-safe blade retention system in addition to a primary load path. In certain engine configurations, the fan blade root (also referred to as an trunnion) is attached to a fan disk via a bearing to achieve the desired fan blade pitch change. The bearing / attachment system is designed for certain load conditions and bird intrusion loads, and includes a redundant / fail-safe blade retention system designed to minimize the impact on the total weight of the fan assembly. Specifically, the fan assembly includes a fan blade, a trunnion mechanism with a trunnion, a first attachment system and a second attachment system, and a disk with a disk segment. The trunnion extends at least partially through the disk segment and is attached to the disk segment along a preload path (i.e., the load path designed for the fan assembly in normal operation) using a first attachment system. In addition, the first attachment system and the second attachment system also include a first retention feature and a second retention feature, respectively, which are separated from the preload path, thereby defining an alternative, fail-safe load path.

[0040] Thus, during normal operation of the engine, the first attachment system secures the trunnion to the disk segment along a first load path defined by the trunnion, the first attachment system, the disk, and the fan blade. However, when the trunnion fails (thereby preventing portions of the first attachment system from functioning as designed), the first retention features and the second retention features of the first attachment system and the second attachment system, respectively, together retain the trunnion within the disk segment along a second load path different from the first load path (i.e., an alternative, fail-safe load path).

[0041] In at least some embodiments, the blade retention system may be incorporated into a fan assembly having an unducted configuration (e.g., a fan assembly without an outer nacelle surrounding the fan assembly). In such a configuration, the blade retention system may reduce the likelihood that a fan blade will become loose and contact the fuselage of, for example, an aircraft including an engine having an unducted fan assembly.

[0042] Referring now to the drawings, wherein like numerals represent like elements throughout the several views, Figure 1 is a schematic cross-sectional view of a gas turbine engine 10 according to an embodiment of the present disclosure. Specifically, Figure 1 A turbofan engine having a rotor assembly having a single-stage unducted rotor blade is provided. Therefore, the rotor assembly may be referred to herein as a "unducted fan", or the entire engine 10 may be referred to as a "unducted turbofan engine". In addition, Figure 1 The engine 10 includes a third flow path extending from the compressor section to the rotor assembly above the turbine, as will be explained in greater detail below.

[0043] For reference, the engine 10 defines an axial direction A, a radial direction R, and a circumferential direction C. Further, the engine 10 defines an axial centerline or longitudinal axis 12 extending along the axial direction A. Generally, the axial direction A extends parallel to the longitudinal axis 12, the radial direction R extends outwardly and inwardly from the longitudinal axis 12 to the longitudinal axis 12 in a direction orthogonal to the axial direction A, and the circumferential direction extends three hundred sixty degrees (360°) around the longitudinal axis 12. The engine 10 extends between a front end 14 and a rear end 16, e.g., along the axial direction A.

[0044] The engine 10 includes a turbine 20 and a rotor assembly (also referred to as a fan section 50) located upstream thereof. Generally, the turbine 20 includes a compressor section, a combustion section, a turbine section, and an exhaust section in a flow series order. Specifically, as shown in FIG. Figure 1 As shown, the turbine 20 includes a core housing 22 that defines an annular core inlet 24. The core housing 22 also at least partially surrounds a low-pressure system and a high-pressure system. For example, the core housing 22 shown at least partially surrounds and supports a supercharger or low-pressure ("LP") compressor 26 for pressurizing air entering the turbine 20 through the core inlet 24. A high-pressure ("HP"), multi-stage, axial-flow compressor 28 receives the pressurized air from the LP compressor 26 and further increases the pressure of the air. The pressurized air flow flows downstream to the combustor 30 of 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.

[0045] It should be understood that as used herein, the terms "high / low speed" and "high / low pressure" are used interchangeably for high pressure / high speed systems and low pressure / low speed systems. In addition, it should be understood that the terms "high" and "low" are used in the same context to distinguish between the two systems and are not meant to imply any absolute speed and / or pressure values.

[0046] The high energy combustion products flow downstream from the combustor 30 to the HP turbine 32. The HP turbine 32 drives the HP compressor 28 via a high pressure shaft 36. In this regard, the HP turbine 32 is drivingly coupled to the HP compressor 28. The high energy combustion products then flow to the LP turbine 34. The LP turbine 34 drives the LP compressor 26 and components of the fan section 50 via an LP shaft 38. In this regard, the LP turbine 34 is drivingly coupled to components of the LP compressor 26 and the fan section 50. In the exemplary embodiment, the LP shaft 38 is coaxial with the HP shaft 36. After driving each of the HP and LP turbines 32, 34, the combustion products exit the turbine 20 through a turbine exhaust nozzle 40.

[0047] Thus, the turbine 20 defines a working gas flow path or core duct 46 that extends between the core inlet 24 and the turbine exhaust nozzle 40. The core duct 46 is an annular duct located generally inwardly of the core shroud 22 in the radial direction R. The core duct 46 (e.g., the working gas flow path through the turbine 20) may be referred to as a secondary flow.

[0048] The fan section 50 includes a fan 52, which is the main fan in this example embodiment. Figure 1 In the illustrated embodiment, the fan 52 is an open rotor or unducted fan 52. In this manner, the engine 10 may be referred to as an open rotor engine.

[0049] As shown, fan 52 includes an array of fan blades 54 ( Figure 1 Only one is shown). Fan blades 54 are capable of rotating, for example, about longitudinal axis 12. As described above, fan 52 is drivingly coupled to low pressure turbine 34 via LP shaft 38. Figure 1 In the embodiment shown in FIG. 5 , the fan 52 is coupled to the LP shaft 38 via a reduction gearbox 55 , for example, in an indirect drive or gear drive configuration.

[0050] In addition, the array of fan blades 54 can be arranged equally spaced about the longitudinal axis 12. Each fan blade 54 has a root and a tip and a span defined therebetween. Each fan blade 54 defines a central blade axis 56. For the present embodiment, each fan blade 54 of the fan 52 is capable of rotating about its central blade axis 56, for example in unison with one another. One or more actuators 58 are provided to facilitate such rotation, and thus can be used to change the pitch of the fan blades 54 about their respective central blade axes 56.

[0051] The fan section 50 also includes a fan guide vane array 60 ( Figure 1 The fan guide vanes 62 are arranged around the longitudinal axis 12. For this embodiment, the fan guide vanes 62 cannot rotate around the longitudinal axis 12. Each fan guide vane 62 has a root and a tip and a span defined therebetween. The fan guide vanes 62 can be arranged as shown in FIG. Figure 1 It is shown unshielded, or may be shielded, for example, by an annular shroud spaced outwardly in the radial direction R from the tip of the fan guide vanes 62 or attached to the fan guide vanes 62 .

[0052] Each fan guide vane 62 defines a central blade axis 64. For the present embodiment, each fan guide vane 62 of the fan guide vane array 60 is capable of rotating about its respective central blade axis 64, for example in unison with one another. One or more actuators 66 are provided to facilitate such rotation and thus may be used to change the pitch of the fan guide vanes 62 about their respective central blade axis 64. However, in other embodiments, each fan guide vane 62 may be fixed or unable to pitch about its central blade axis 64. The fan guide vanes 62 are mounted to a fan housing 70.

[0053] like Figure 1 As shown, in addition to the unducted fan 52, a ducted fan 84 is also included behind the fan 52, so that the engine 10 includes both ducted fans and unducted fans, both of which are used to generate thrust by the movement of air without passing through at least a portion of the turbine 20 (e.g., for the illustrated embodiment, without passing through the HP compressor 28 and the combustion section). The ducted fan 84 is capable of rotating about the same axis as the fan blades 54 (e.g., the longitudinal axis 12). For the illustrated embodiment, the ducted fan 84 is driven by the low-pressure turbine 34 (e.g., coupled to the LP shaft 38). In the illustrated embodiment, as described above, the fan 52 may be referred to as a primary fan, while the ducted fan 84 may be referred to as a secondary fan. It should be understood that these terms "primary" and "secondary" are for convenience and do not imply any special importance, authority, etc.

[0054] The ducted fan 84 includes a plurality of fan blades ( Figure 1 The fan blades are arranged in a single stage, and thus the ducted fan 84 may be referred to as a single-stage fan. The fan blades of the ducted fan 84 may be arranged equally spaced about the longitudinal axis 12. Each blade of the ducted fan 84 has a root and a tip and a span defined therebetween.

[0055] The fan cover 70 annularly surrounds at least a portion of the core cover 22, and is generally located outside at least a portion of the core cover 22 in the radial direction R. Specifically, a downstream section of the fan cover 70 extends on the front portion of the core cover 22 to define a fan duct flow path, or simply referred to as a fan duct 72. According to the present embodiment, the fan flow path or the fan duct 72 can be understood as forming at least a portion of the third flow of the engine 10.

[0056] Incoming air may enter the fan duct 72 through the fan duct inlet 76 and may be discharged through the fan exhaust nozzle 78 to generate propulsive thrust. The fan duct 72 is an annular duct that is generally positioned outside the core duct 46 in the radial direction R. The fan cowl 70 and the core cowl 22 are connected together and are connected by a plurality of substantially radially extending, circumferentially spaced fixed struts 74 ( Figure 1 The fan duct 72 and the core duct 46 may be supported by the fan duct 70 and the core duct 22. ... Each fixed strut 74 may have an aerodynamic profile to guide the air flowing therefrom. In addition to the fixed struts 74, other struts may also be used to connect and support the fan duct 70 and / or the core duct 22. In many embodiments, the fan duct 72 and the core duct 46 may at least partially extend together (generally axially) on the opposite sides (e.g., the opposite radial sides) of the core duct 22. For example, the fan duct 72 and the core duct 46 may each extend directly from the leading edge 44 of the core duct 22, and may partially extend together generally axially on the opposite radial sides of the core duct 22.

[0057] The engine 10 further defines or includes an inlet duct 80. The inlet duct 80 extends between the engine inlet 82 and the core inlet 24 / fan duct inlet 76. The engine inlet 82 is generally defined at the front end of the fan cowl 70 and is positioned between the fan 52 and the fan guide vane array 60 in the axial direction A. The inlet duct 80 is an annular duct that is positioned inside the fan cowl 70 in the radial direction R. Air flowing downstream along the inlet duct 80 is divided (not necessarily evenly) into the core duct 46 and the fan duct 72 by the fan duct splitter or the leading edge 44 of the core cowl 22. In the illustrated embodiment, the inlet duct 80 is wider than the core duct 46 in the radial direction R. The inlet duct 80 is also wider than the fan duct 72 in the radial direction R.

[0058] It is noteworthy that for the illustrated embodiment, the engine 10 also includes an array of inlet guide vanes 86 located in the inlet duct 80, upstream of the ducted fan 84 and downstream of the engine inlet 82. The array of inlet guide vanes 86 is arranged around the longitudinal axis 12. For the present embodiment, the inlet guide vanes 86 cannot rotate around the longitudinal axis 12. Each inlet guide vane 86 defines a central blade axis (not labeled for clarity) and can rotate around its respective central blade axis, for example, in unison with each other. Therefore, the inlet guide vanes 86 can be considered as variable geometry components. One or more actuators 88 are provided to facilitate such rotation, and can therefore be used to change the pitch of the inlet guide vanes 86 around their respective central blade axes. However, in other embodiments, each inlet guide vane 86 may be fixed or unable to pitch around its central blade axis.

[0059] In addition, engine 10 includes an array of outlet guide vanes 90 located downstream of ducted fan 84 and upstream of fan duct inlet 76. Like the array of inlet guide vanes 86, the array of outlet guide vanes 90 is not rotatable about longitudinal axis 12. However, for the illustrated embodiment, unlike the array of inlet guide vanes 86, the array of outlet guide vanes 90 is configured as fixed pitch outlet guide vanes.

[0060] In addition, it should be understood that for the illustrated embodiment, the fan exhaust nozzle 78 of the fan duct 72 is further configured as a variable geometry exhaust nozzle. Therefore, the engine 10 includes one or more actuators 68 for adjusting the variable geometry exhaust nozzle. For example, the variable geometry exhaust nozzle can be configured to change the total cross-sectional area (e.g., the area of ​​the nozzle in a plane perpendicular to the longitudinal axis 12) to adjust the amount of thrust generated based on one or more engine operating conditions (e.g., temperature, pressure, mass flow rate, etc. of the airflow passing through the fan duct 72). Fixed geometry exhaust nozzles may also be used.

[0061] The combination of the array of inlet guide vanes 86 located upstream of ducted fan 84, the array of outlet guide vanes 90 located downstream of ducted fan 84, and fan exhaust nozzle 78 may more efficiently generate third flow thrust Fn during one or more engine operating conditions. 3S .

[0062] In addition, reference Figure 1In an exemplary embodiment, the air passing through the fan duct 72 may be relatively cooler (e.g., lower in temperature) than one or more fluids used in the turbine 20. Therefore, one or more heat exchangers 94 may be positioned in thermal communication with the fan duct 72. For example, one or more heat exchangers 94 may be disposed within the fan duct 72 and used to cool one or more fluids from the core engine using the air passing through the fan duct 72 as a resource for removing heat from the fluid (e.g., compressor exhaust, oil, or fuel).

[0063] Although not shown, heat exchanger 94 may be an annular heat exchanger extending substantially 360 degrees (e.g., at least 300 degrees, such as at least 330 degrees) in fan duct 72. In this manner, heat exchanger 94 may effectively utilize air passing through fan duct 72 to cool one or more systems (e.g., lube oil system, compressor exhaust, electrical components, etc.) of engine 10. Heat exchanger 94 uses air passing through fan duct 72 as a heat sink and accordingly increases the temperature of the air downstream of heat exchanger 94 exiting fan exhaust nozzle 78.

[0064] It should be understood that Figure 1 The engine 10 shown and described herein is for example only, and embodiments of the present disclosure may also be incorporated into other gas turbine engines. For example, in other exemplary embodiments, embodiments of the present disclosure may also be incorporated into a ducted turbofan engine (e.g., a turbofan engine having an outer nacelle surrounding a plurality of fan blades of a fan).

[0065] Still refer to Figure 1 , now also refer to Figure 2 , the fan section 50 includes a variable pitch fan assembly 48 having a plurality of fan blades 54 coupled to the disk 42 in a spaced apart manner. The disk 42 may have a generally annular shape about an axial direction A1, as described below. The fan blades 54 extend outwardly from the disk 42 generally in a radial direction R1. Each fan blade 54 is also capable of rotating relative to the disk 42 about a central blade axis 56 by virtue of the fan blades 54 being operably coupled to an actuator 58, wherein the actuator 58 is configured to change the pitch of the fan blades 54 in unison.

[0066] Special References Figure 2 , showing Figure 11. A perspective view of an embodiment of a fan assembly 48 of a fan section 50 of an engine 10 of FIG. For the illustrated embodiment, the fan assembly 48 includes twelve (12) fan blades 54. From a loading perspective, such a number of blades can allow the span of each fan blade 54 to be reduced, so that the overall diameter of the fan assembly 48 can also be reduced. That is, in other embodiments, the fan assembly 48 can have any suitable number of blades and any suitable diameter. In certain suitable embodiments, the fan includes at least eight (8) blades. In another suitable embodiment, the fan can have at least fifteen (15) blades. In yet another suitable embodiment, the fan can have at least eighteen (18) blades. In one or more of these embodiments, the fan includes twenty-six (26) or fewer blades, such as twenty (20) or fewer blades.

[0067] Each fan blade 54 is attached to the disk 42 using a trunnion mechanism 100. More specifically, the disk 42 includes a plurality of disk segments 92 that are rigidly coupled together or integrally molded together in a generally annular shape (e.g., a polygonal shape). Each fan blade 54 is coupled to a corresponding disk segment 92 using a corresponding trunnion mechanism 100. For the illustrated embodiment, each trunnion mechanism 100 includes a trunnion 102, a first attachment system 96, and a redundant second attachment system 98.

[0068] In addition, each trunnion 102 includes a platform 95 for attachment to a corresponding one of the fan blades 54 and a shaft 97 extending at least partially through a corresponding one of the disk segments 92 (see, e.g., Figure 3 As will be discussed in greater detail herein, trunnion 102 is attached to disk segment 92 using first attachment system 96 and second attachment system 98 , depending on whether a fault has occurred in fan assembly 48 .

[0069] Thus, during operation of fan assembly 48 and rotation of disk 42, trunnion mechanisms 100 help retain their associated fan blade 54 on disk 42 or disk segment 92. More specifically, each trunnion mechanism 100 helps provide a secure connection for fan blade 54 about longitudinal axis 12 ( Figure 1 ) provides a load path from the corresponding fan blade 54 to the corresponding disk segment 92. In addition, the trunnion mechanism 100 or its first attachment system 96 facilitates the corresponding fan blade 54 relative to the disk 42 about the central blade axis 56 ( Figure 1 )Rotate.

[0070] Reference now Figure 3 , according to an embodiment of the present disclosure, a single disc segment 92 and a trunnion mechanism 100 are depicted respectively. More specifically, Figure 3An exploded perspective view of a disk segment 92 and a trunnion mechanism 100 according to an embodiment of the present disclosure is provided. As shown, each trunnion mechanism 100 generally defines an axial direction A2, a radial direction R2, and a circumferential direction C2. The axial direction A2 of the trunnion mechanism 100 may be substantially parallel to the central blade axis 56 ( Figure 1 ), so it can be roughly parallel to Figure 1 The engine 10 defines a radial direction R1.

[0071] Furthermore, as described above, the trunnion mechanism 100 generally includes the trunnion 102 and the first and second attachment systems 96, 98 (see, e.g., Figure 5 ). In addition, as shown, the trunnion 102 generally includes a platform 95 and a shaft 97. The platform 95 of the trunnion 102 defines an axial dovetail groove 104, which extends generally in the radial direction R2 of the trunnion mechanism 100 for receiving a dovetail tenon 106. For clarity, the dovetail tenon 106 is depicted as a separate component, however, in practice, the dovetail tenon 106 may be a built-in integral part of the fan blade 54 (i.e., the root of the fan blade 54). More specifically, for the illustrated embodiment, the axial dovetail groove 104 defines an outer end 105 in the radial direction R2 of the trunnion mechanism 100, so that the dovetail tenon 106 can slide into the axial dovetail groove 104 defined in the platform 95. However, it should be understood that in other embodiments, the fan blade 54 may be attached to the disk 42 or disk segment 92 in any other suitable manner.

[0072] For example, in other embodiments, the trunnion mechanism 100 may include a spar-type trunnion, wherein the shaft 97 of the trunnion 102 extends substantially into the fan blade 54 and forms a frame for the fan blade 54. For such embodiments, the shaft 97 of the trunnion 102 may be integrally formed with at least a portion of the fan blade 54. Additionally or alternatively, the trunnion mechanism 100 may include a trunnion capable of receiving a pinned root of the fan blade 54. For such embodiments, the pin may extend through an opening in the trunnion 102 that is aligned with an opening in the root of the fan blade 54.

[0073] See also Figure 3 and Figure 5 The first attachment system 96 generally includes one or more bearings 108, 126, one or more inserts 116 disposed between the trunnion 102 and the disc segment 92, one or more bearing supports 120, 124 ( Figure 5 ) and at least one coupling nut 122 ( Figure 5 ). Specifically, Figure 3 and Figure 5As shown, the first attachment system 96 may include a first line contact bearing 108 (eg, having an inner race 110 , an outer race 112 , and a plurality of rollers 114 ) and a second line contact bearing 126 (eg, having an inner race 128 , an outer race 130 , and a plurality of rollers 132 ).

[0074] like Figure 5 As shown, in the illustrated embodiment, the first line contact bearing 108 is oriented at a different angle (measured from the centerline axis of the roller 114 relative to the axial direction A2, and measured from the centerline axis of the roller 132 relative to the axial direction A2) than the second line contact bearing 126. More specifically, the line contact bearings 108, 126 are preloaded with each other in a face-to-face (or dual) arrangement, wherein the centerline axes are oriented substantially perpendicular to each other. However, it should be understood that in other embodiments, the line contact bearings 108, 126 can be arranged in series instead so as to be oriented substantially parallel to each other.

[0075] Furthermore, for use as bearings 108, 126, at least the following types of line contact type rolling element bearings are considered: cylindrical roller bearings; cylindrical roller thrust bearings; tapered roller bearings; spherical roller bearings; spherical roller thrust bearings; needle roller bearings; and tapered roller needle bearings. When assembled, the coupling nut 122 ( Figure 5 ) engages with the line contact bearing 126 (or any other suitable component) to clamp the remaining components of the trunnion mechanism 100 between the coupling nut 122 and the disc segment 92, thereby maintaining the trunnion mechanism 100 attached to the disc segment 92.

[0076] However, it should be understood that in other embodiments, the first attachment system 96 of the trunnion mechanism 100 may additionally or alternatively include any other suitable type of bearing. For example, in other embodiments, the trunnion mechanism 100 may include a ball bearing or any other suitable bearing. Moreover, in still other embodiments, any other suitable first attachment system may be provided to attach the trunnion 102 to the disc segment 92. Now referring to Figure 3-5 , the disk segment 92 may further include a collar 134 , wherein the collar 134 extends away from the disk segment 92 generally in the axial direction A2 .

[0077] Reference now Figure 5-13 , various partial views of an embodiment of a fan assembly 48 are shown. With particular reference to Figure 5 , shows a side cross-sectional view of an embodiment of a disk segment 92 and a trunnion mechanism 100 of a fan assembly 48 according to the present disclosure. For example, as shown, the trunnion 102 is attached to the disk segment 92 using the first attachment system 96, such as along a preload path 136 defined by bearings 108, 126, insert 116, bearing supports 120, 124, and coupling nut 122.

[0078] In addition, as shown, the first attachment system 96 and the second attachment system 98 include a first retention feature 146 and a second retention feature 150, respectively. More specifically, in an embodiment, as shown, the first retention feature 146 and the second retention feature 150 are separated from the preload path 136 (i.e., loads do not pass through the first retention feature 146 and the second retention feature 150 during normal operation). Therefore, during operation of the fan assembly 48, the first attachment system 96 retains the trunnion 102 within the disk 42 along the first load path 138 (e.g., through the trunnion 102, the disk segment 92, and then through the fan blade 54). However, when the trunnion 102 fails (as shown by reference numeral 142), the first retention feature 146 and the second retention feature 150 together retain the trunnion 102 within the disk segment 92 along the second load path 140. Specifically, in an embodiment, as shown Figure 5 As shown, first load path 138 is distinct from second load path 140 such that a failure 142 in trunnion 102 does not cause fan blade 54 to release from disk segment 92. Additionally, as shown, first load path 138 and second load path 140 are generally defined inboard of outer surface 144 of disk segment 92 of disk 42.

[0079] In addition, if Figure 5 As shown, the first retention feature 146 of the first attachment system 96 can be a first protrusion 147 of the first insert 116 of one or more inserts 116 described herein. In such an embodiment, as shown, the first protrusion 147 is received in a corresponding first recess 148 of the disc segment 92 of the disc 42.

[0080] In addition, if Figure 6 As shown, the first insert 116 may have a generally annular or ring-like shape. Therefore, in an embodiment, the first insert 116 may be segmented. Specifically, as shown in FIG. Figure 6 As shown, the first insert 116 can be segmented into a plurality of segments 117 that are arranged together to form a generally annular or ring-like shape. In addition, as shown, the plurality of segments 117 of the first insert 116 can be held together using, for example, a retaining member 119 (which can be a spring).

[0081] In addition, refer again Figure 5 , the second retaining feature 150 may be a second protrusion 151 of the second insert 118 of the second attachment system 98. In such an embodiment, the second protrusion 151 is configured to engage with a corresponding second protrusion 152 of the shaft 97 of the trunnion 102. Furthermore, as shown, during normal operation of the engine 10, a gap 154 ​​is maintained between the second protrusion 151 of the second insert 118 and the corresponding second protrusion 152 of the shaft 97 of the trunnion 102.

[0082] Thus, in an embodiment, when the trunnion 102 fails 142, the gap 154 ​​closes, causing the second protrusion 151 of the second insert 118 to engage with the corresponding second protrusion 152 of the shaft 97 of the trunnion 102 to maintain the trunnion 102 and the fan blade 54 fixed within the disk segment 92 of the disk 42. In such an embodiment, as shown, when the trunnion 102 fails 142, the second load path 140 can be at least partially defined by the first protrusion 147 and the second protrusion 151. Thus, in an example, the first retention feature 146 and the second retention feature 150 are configured to retain the trunnion 102 in the disk segment 92 and together provide a redundant retention capability of the trunnion 102 within the disk 42 (or more specifically, the collar 134 of the disk segment 92).

[0083] In certain embodiments, such as Figure 5 , 7 As shown in FIG. 8 , the corresponding second protrusion 152 of the shaft 97 of the trunnion 102 may be a flange 156 integrally formed with the shaft 97. In an alternative embodiment, as shown in FIG. Fig.12 and 13 As shown, the corresponding second protrusion 152 of the shaft 97 may be defined by a plurality of fasteners 158 extending through at least a portion of the trunnion 102 .

[0084] Reference now Figure 7 , shows a side cross-sectional view of another embodiment of a disk segment 92 and trunnion mechanism 100 of a fan assembly 48 according to the present disclosure. Figure 5 In addition to the features shown, Figure 7 The embodiment also includes a fastening member 160 extending through the shaft 97 of the trunnion 102 and at least a portion of the fan blade 54. In some embodiments, for example, the fastening member 160 can be a fastener or a cable. For example, in an embodiment, as Figure 7 As shown, the fastening member 160 is a fastener 166 having a fastener head 168 and a fastener shaft 170. Additionally, as shown, the shaft 97 of the trunnion 102 may also be provided with a flange 163 such that the fastener shaft 170 of the fastener 166 may be received therethrough.

[0085] Thus, during normal operation of engine 10, fastener head 168 is spaced apart from flange 163 via gap 162; gap 154 ​​is maintained between second protrusion 151 of second insert 118 and corresponding second protrusion 152 of shaft 97 of trunnion 102; and trunnion 102 and fan blade 54 are retained within disk segment 92 of disk 42 via first attachment system 96, for example, as shown along preload path 136.

[0086] Thus, in an embodiment, when the trunnion 102 fails, as indicated by reference numerals 142 and 143, the gaps 154, 162 are closed, the second protrusion 151 of the second insert 118 engages with the corresponding second protrusion 152 of the shaft 97, and the fastener head 168 engages with the corresponding flange 163 to retain the trunnion 102 and the fan blade 54 within the disk segment 92 of the disk 42. In such an embodiment, as shown, when the trunnion 102 fails 142, the second load path 140 can be at least partially defined by the first protrusion 147 and the second protrusion 151. Thus, in an example, the first retention feature 146 and the second retention feature 150 are configured to retain the trunnion 102 in the disk segment 92 when the trunnion 102 fails (even in multiple places as shown by 142 and 143).

[0087] Reference now Figure 8 , 9 13, various views of further embodiments of the disk segment 92 and the trunnion mechanism 100 of the fan assembly 48 according to the present disclosure are shown. Specifically, as shown in the figure, Figure 8 , 9 The first retention feature 146 of the first attachment system 96 of the embodiment of FIG. 13 includes a plurality of fasteners 186 that pass through the disc segment 92 of the disc 42 and are fixed to the first insert 116. For example, as Fig. 9 As shown, the plurality of fasteners 186 may be arranged circumferentially around the disc segment 92. Thus, in embodiments, the plurality of fasteners 186 may be used in place of, or in addition to, the first protrusions 147 of the first insert 116. Furthermore, in such embodiments, as shown, when the trunnion 102 fails, the second load path 140 is at least partially defined by the plurality of fasteners 186 (as well as the first insert 116 and the second insert 118).

[0088] Reference now Fig.10 and 11 , various views of another embodiment of a disk segment 92 and a trunnion mechanism 100 of a fan assembly 48 according to the present disclosure are shown. Specifically, as shown in the figure, Fig.10 and 11 The second retention feature 150 of the second attachment system 98 of the embodiment also includes a frame member 188 fixed to the flange 190 of the disk segment 92 of the disk 42. In such an embodiment, as shown, when the trunnion 102 fails (as shown at 142), the second load path 140 is at least partially defined by the frame member 188.

[0089] More specifically, if Fig.10 and 11As shown, during normal operation of engine 10, one or more radially extending projections 189 of frame member 188 are spaced apart from edge 194 of disk segment 92 of disk 42 via gap 192. Furthermore, during normal operation of engine 10, trunnion 102 and fan blade 54 are retained within disk segment 92 of disk 42 along first load path 138 via first attachment system 96. Thus, in an embodiment, when trunnion 102 fails, as shown by reference numeral 142, gap 192 closes and radially extending projection 189 of frame member 188 engages (e.g., contacts) edge 194 of disk segment 92 of disk 42 to maintain fixation of trunnion 102 and fan blade 54 within disk segment 92 of disk 42.

[0090] In additional embodiments, Figure 5 , 7 , 8 and 10, the fan assembly 48 may also include at least one sensor 172, 174, 175 for monitoring the gaps 154, 162, 192, because changes in the gaps 154, 162, 192 indicate an imbalance of the fan blades 54 and a potential failure of the trunnion 102. In such an embodiment, as an example, the sensors 172, 174, 175 may be connected to the controller 176 ( Fig.14 ) are communicatively coupled, the controller 176 is configured to generate an alarm if the gaps 154, 162 are closed and / or reduced.

[0091] For example, Fig.14 , a block diagram of components that may be included in the controller 176 according to the present disclosure is shown. As shown, the controller 176 may include one or more processors 178 and one or more memory devices 180, configured to perform various computer-implemented functions (e.g., execute the methods, steps, calculations, etc. disclosed herein and store related data). In addition, the controller 176 may also include a communication module 182 to facilitate the controller 176 to communicate with the sensors 172, 174, 175 ( Figure 5 , 7 , 8 and 10).

[0092] In addition, as shown, the communication module 182 may include a sensor interface 184 (e.g., one or more analog-to-digital converters) to allow signals transmitted from the sensors 172, 174, 175 to be converted into signals that can be understood and processed by the processor 178. It should be understood that the sensors 172, 174, 175 may be communicatively coupled to the communication module 182 using any suitable means. For example, Fig.14As shown, the sensors 172, 174, 175 can be coupled to the sensor interface 184 via a wired connection. However, in other embodiments, the sensors 172, 174, 175 can be coupled to the sensor interface 184 via a wireless connection, such as by using any suitable wireless communication protocol known in the art. Thus, the processor 178 can be configured to receive one or more signals from the sensors 172, 174, 175.

[0093] As used herein, the term "processor" refers not only to what is known in the art as an integrated circuit included in a computer, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. The processor 178 may also be configured to calculate advanced control algorithms and communicate with various Ethernet or serial protocols (Modbus, OPC, CAN, etc.) as well as classical analog or digital signals. In addition, the memory device 180 may generally include a memory element, including but not limited to a computer-readable medium (e.g., a random access memory (RAM)), a computer-readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disk read-only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD), and / or other suitable memory elements. Such a memory device 180 may generally be configured to store suitable computer-readable instructions, which, when executed by the processor 178, configure the controller 176 to perform various functions as described herein.

[0094] As can be seen from the description herein, various embodiments of gas turbine engines are provided. Certain of these embodiments may be non-ducted single-spool gas turbine engines or ducted turbofan engines. Various additional aspects of one or more of these embodiments are discussed herein. These exemplary aspects may be combined with one or more of the exemplary gas turbine engines discussed above with respect to the accompanying drawings.

[0095] For example, in some embodiments of the present disclosure, the engine may include a heat exchanger located in an annular duct (eg, located in the third flow).The heat exchanger may extend substantially continuously in a circumferential direction of the gas turbine engine.

[0096] In one or more of these embodiments, the threshold power or disk load of the fan (e.g., an unducted single rotor or primarily forward fan) at cruise altitude during the cruise operating mode may range from 25 hp / ft2 to 100 hp / ft2. 2 ) or greater. In a specific embodiment of the engine, the structure provided herein produces 80 hp / ft at cruising altitude during the cruise operating mode. 2 and 160hp / ft 2or higher power loads, depending on whether the engine is an open rotor or ducted engine.

[0097] In various embodiments, the engine of the present disclosure is applied to a carrier with a cruising altitude of up to about 65,000 feet. In certain embodiments, the cruising altitude is between about 28,000 feet and about 45,000 feet. In certain embodiments, the cruising altitude is expressed as a flight altitude based on the standard air pressure at sea level, wherein the cruising flight condition is between FL280 and FL650. In another embodiment, the cruising flight condition is between FL280 and FL450. In certain embodiments, the cruising altitude is at least defined based on air pressure, wherein based on a sea level pressure of about 14.70psia and a sea level temperature of about 59 degrees Fahrenheit, the cruising altitude is between about 4.85psia and about 0.82psia. In another embodiment, the cruising altitude is between about 4.85psia and about 2.14psia. It should be understood that in certain embodiments, the cruising altitude range defined by pressure can be adjusted based on different reference sea level pressures and / or sea level temperatures.

[0098] It should be understood, therefore, that an engine of this configuration may be configured to produce at least about 25,000 pounds and less than about 80,000 pounds of thrust during operation at rated speed, such as about 25,000 to 50,000 pounds of thrust during operation at rated speed, such as about 25,000 to 40,000 pounds of thrust during operation at rated speed.

[0099] Moreover, in certain exemplary embodiments, the rotor assembly may define a rotor diameter (or fan diameter) that is at least 10 feet, such as at least 11 feet, such as at least 12 feet, such as at least 13 feet, such as at least 15 feet, such as at least 17 feet, such as up to 28 feet, such as up to 26 feet, such as up to 24 feet, such as up to 18 feet. For example, referring to Figure 1 In an embodiment of the present invention, the fan 52 may define a fan diameter as described above.

[0100] Thus, in one or more of these embodiments, it will be appreciated that a blade retention system may be incorporated into an engine having a relatively large diameter ductless fan. A larger fan diameter may allow for improved efficiency during at least certain operations, and may be achieved at least in part by removing an outer nacelle surrounding the fan. However, increasing the size of the fan may result in heavier fan blades, and removing the outer nacelle may take away the built-in fan blade guards of an aircraft containing such an engine. Therefore, an engine having such a ductless fan may be more likely to require auxiliary retention features for the fan blades to reduce the likelihood of the fan blades detaching from the fan and the engine during operation.

[0101] In various embodiments, it should be understood that the ratio of the number of blades included in the engine can be less than, equal to, or greater than 1:1. For example, in a particular embodiment, the engine includes twelve (12) fan blades and ten (10) blades. In other embodiments, the blade assembly includes a larger ratio of the number of blades to the number of fan blades. For example, in a particular embodiment, the engine includes ten (10) fan blades and twenty-three (23) blades. For example, in certain embodiments, the ratio of the number of blades included in the engine to the number of blades can be between 1:2 and 5:2. This ratio can be adjusted based on various factors, including the size of the blades, to ensure that the desired amount of vortex is removed from the airflow discharged by the main fan.

[0102] Furthermore, in certain exemplary embodiments, when the engine includes a tertiary flow and an intermediate fan (a ducted fan located behind the main forward fan), the ratio R1 / R2 can be between about 1 and 10, or between 2 and 7, or at least about 3.3, at least about 3.5, at least about 4, and less than or equal to about 7, where R1 is the radius of the main fan and R2 is the radius of the intermediate fan.

[0103] It should be understood that various embodiments of the engine (e.g., the unducted single rotor engine shown and described herein) may allow normal subsonic aircraft cruise altitude operations at speeds of Mach 0.5 or above. In certain embodiments, the engine allows normal aircraft operations between Mach 0.55 and Mach 0.85 at cruise altitude. In yet other specific embodiments, the engine allows normal aircraft operations between Mach 0.75 and Mach 0.85. In certain embodiments, the engine allows rotor blade tip speeds of 750 feet per second (fps) or less. In other embodiments, the rotor blade tip speed under cruise flight conditions may be 650 to 900 fps, or 700 to 800 fps.

[0104] The fan pressure ratio (FPR) of the fan of the fan assembly may be 1.04 to 1.20, or in some embodiments 1.05 to 1.1, or in some embodiments less than 1.08 when measured at the fan blades at cruise flight conditions.

[0105] In order to operate the gas turbine engine with a fan having the above characteristics to define the above FPR, a gear assembly can be provided to reduce the speed of the fan assembly relative to the drive shaft (e.g., a low-pressure shaft coupled to a low-pressure turbine). In some embodiments, the gear ratio of the input speed to the output speed is greater than 4.1. For example, in a specific embodiment, the gear ratio is in the range of 4.1 to 14.0, in the range of 4.5 to 14.0, or in the range of 6.0 to 14.0. In certain embodiments, the gear ratio is in the range of 4.5 to 12 or in the range of 6.0 to 11.0. Therefore, in some embodiments, the fan can be configured to rotate at a speed of 700 to rpm under cruise flight conditions, while the power turbine (e.g., the low-pressure turbine) is configured to rotate at a speed of 2,500 to 15,000 rpm under cruise flight conditions. In a specific embodiment, the fan can be configured to rotate at a speed of 850 to 1,350 rpm under cruise flight conditions, while the power turbine is configured to rotate at a speed of 5,000 to 10,000 rpm under cruise flight conditions.

[0106] With regard to the turbine of the gas turbine engine, the compressor and / or turbine may include various numbers of stages. As disclosed herein, the number of stages includes the number of rotors or blades in a particular component (e.g., a compressor or turbine). For example, in some embodiments, the low-pressure compressor may include 1 to 8 stages, the high-pressure compressor may include 8 to 15 stages, the high-pressure turbine may include 1 to 2 stages, and / or the low-pressure turbine (LPT) may include 3 to 7 stages. Specifically, the LPT may have 4 stages, or between 4 and 7 stages. For example, in certain embodiments, the engine may include a single-stage low-pressure compressor, an 11-stage high-pressure compressor, a two-stage high-pressure turbine, and an LPT of 4 or between 4 and 7 stages. As another example, the engine may include a three-stage low-pressure compressor, a 10-stage high-pressure compressor, a two-stage high-pressure turbine, and a 7-stage low-pressure turbine.

[0107] The core engine is typically enclosed in an outer casing that defines half of the core diameter (Dcore), which can be considered as the maximum extension from the centerline axis (reference to R). In certain embodiments, the engine includes a length (L) from the longitudinal (or axial) front end to the longitudinal rear end. In various embodiments, the engine defines a ratio of L / Dcore to provide reduced installation resistance. In one embodiment, L / Dcore is at least 2. In another embodiment, L / Dcore is at least 2.5. In some embodiments, L / Dcore is less than 5, less than 4 and less than 3. In various embodiments, it should be understood that L / Dcore is applicable to non-ducted single-rotor engines.

[0108] Reduced installation drag can further improve efficiency, such as improving specific fuel consumption. Additionally or alternatively, reduced drag can enable cruise altitude engines and aircraft to operate at the above Mach numbers at cruise altitude. Certain embodiments can still provide such benefits, namely, reducing the interaction noise between blade assemblies and vane assemblies and / or reducing the overall noise generated by the engine by means of structures located in the annular duct of the engine.

[0109] Although the above-described embodiments describe unshrouded or open rotor engines, it should be understood that the disclosed aspects provided herein may be applied to shrouded or ducted engines, partially ducted engines, rear fan engines, or other gas turbine engine configurations, including engines for marine, industrial, or aviation propulsion systems.

[0110] Further aspects are provided by the subject matter of the following clauses:

[0111] A fan assembly for an engine, the fan assembly comprising: a fan blade; a disk, the disk having a generally annular shape and comprising a disk segment; a trunnion mechanism, the trunnion mechanism comprising a trunnion, a first attachment system and a second attachment system, the trunnion comprising a platform and a shaft, the fan blade being adjacent to the platform of the trunnion, the trunnion extending at least partially through the disk segment and being attached to the disk segment along a preload path using the first attachment system, the first attachment system and the second attachment system respectively comprising a first retaining feature and a second retaining feature separate from the preload path, wherein during operation of the fan assembly, the first attachment system retains the trunnion within the disk along a first load path, and wherein, when the trunnion fails, the first retaining feature and the second retaining feature together retain the trunnion within the disk segment along a second load path, the first load path being different from the second load path.

[0112] A fan assembly as claimed in any preceding clause, wherein the first load path and the second load path are defined inboard of an outer surface of the disk segment of the disk.

[0113] A fan assembly as described in any preceding clause, wherein the first attachment system includes one or more bearings, one or more inserts arranged between the trunnion and the disk segment of the disk, one or more bearing supports, and at least one coupling nut.

[0114] A fan assembly according to any preceding clause, wherein the first retention feature of the first attachment system comprises a first protrusion of a first insert of the one or more inserts, the first protrusion being received within a corresponding first recess of the disk segment of the disk, and when the trunnion fails, the second load path is at least partially defined by the first protrusion of the first insert.

[0115] A fan assembly as claimed in any preceding clause, wherein the first insert is segmented into a plurality of segments arranged together to form a generally annular or ring-like shape.

[0116] A fan assembly as claimed in any preceding clause, wherein the plurality of segments of the first insert are held together using retaining members.

[0117] A fan assembly according to any preceding clause, wherein the first retention feature of the first attachment system includes a plurality of fasteners that pass through the disk segment of the disk and are secured to the first insert, and when the trunnion fails, the second load path is at least partially defined by the plurality of fasteners.

[0118] A fan assembly according to any preceding clause, wherein the second retention feature of the second attachment system includes a second protrusion of a second insert, the second insert being configured to engage with a corresponding second protrusion of the shaft of the trunnion, wherein when the trunnion fails, the second protrusion of the second insert engages the corresponding second protrusion of the shaft of the trunnion to keep the trunnion and the fan blade fixed within the disk segment of the disk.

[0119] A fan assembly as described in any preceding clause, wherein the second protrusion is a flange formed integrally with the second insert.

[0120] A fan assembly as described in any preceding clause, wherein the second protrusion is defined by a plurality of fasteners extending through at least a portion of the trunnion.

[0121] A fan assembly according to any preceding clause, wherein the second attachment system further includes a fastening member extending through the shaft of the trunnion and at least a portion of the fan blade, wherein when the trunnion fails, the fastening member engages a corresponding flange of the shaft of the trunnion to further retain the trunnion and the fan blade within the disk segment of the disk.

[0122] A fan assembly according to any preceding clause, further comprising at least one sensor for monitoring a gap between the fastening member and the corresponding flange, wherein when the gap is closed, an imbalance of the fan blade caused by a failure of the trunnion is detectable, and the at least one sensor is communicatively connected to a controller, and the controller is configured to generate an alarm when the gap is closed.

[0123] A fan assembly as described in any preceding clause, wherein the securing member comprises at least one of a fastener or a cable.

[0124] A fan assembly as described in any preceding clause, wherein the second attachment system further comprises a frame member secured to a flange of the disk segment of the disk, the second load path being at least partially defined by the frame member when the trunnion fails.

[0125] The fan assembly of any preceding clause, wherein the fan assembly is a ductless fan assembly defining a fan diameter of at least 10 feet and at most 28 feet.

[0126] An engine comprises: a core engine; and a variable pitch fan assembly, the variable pitch fan assembly being mechanically connected to the core engine, the fan assembly comprising: a fan blade; a disk having a generally annular shape and comprising a disk segment; a trunnion mechanism, the trunnion mechanism comprising a trunnion, a first attachment system and a second attachment system, the trunnion comprising a platform and a shaft, the fan blade being adjacent to the platform of the trunnion, the trunnion extending at least partially through the disk segment and being attached to the disk segment along a preload path using the first attachment system, the first attachment system and the second attachment system respectively comprising a first retaining feature and a second retaining feature separated from the preload path, wherein during operation of the fan assembly, the first attachment system retains the trunnion within the disk along a first load path, and wherein, when the trunnion fails, the first retaining feature and the second retaining feature together retain the trunnion within the disk segment along a second load path, the first load path being different from the second load path.

[0127] An engine as claimed in any preceding clause, wherein the first load path and the second load path are defined inboard of an outer surface of the disk segment of the disk.

[0128] An engine as described in any preceding clause, wherein the first attachment system includes one or more bearings, one or more inserts arranged between the trunnion and the disk segment of the disk, one or more bearing supports and at least one coupling nut.

[0129] An engine according to any preceding clause, wherein the first retaining feature of the first attachment system comprises a first protrusion of a first insert of the one or more inserts, the first protrusion being received within a corresponding first recess of the disc segment of the disc, and when the trunnion fails, the second load path is at least partially defined by the first protrusion of the first insert.

[0130] An engine as claimed in any preceding clause, wherein the first insert is segmented into a plurality of segments arranged together to form a generally annular or ring-like shape, and wherein the plurality of segments of the first insert are held together using retaining members.

[0131] An engine according to any preceding clause, wherein the second retaining feature of the second attachment system comprises a second protrusion of a second insert, the second insert being configured to engage with a corresponding second protrusion of the shaft of the trunnion, wherein when the trunnion fails, the second protrusion of the second insert engages the corresponding second protrusion of the shaft of the trunnion to maintain the trunnion and the fan blade fixed within the disk segment of the disk.

[0132] This written description uses examples to describe the presently disclosed subject matter and also to enable those skilled in the art to practice such subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the presently disclosed subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that are insubstantially different from the literal language of the claims.

Claims

1. A fan assembly for an engine, characterized in that: The fan assembly comprises: Fan blades; a disk having a generally annular shape and comprising disk segments; a trunnion mechanism, the trunnion mechanism comprising a trunnion, a first attachment system and a second attachment system, the trunnion comprising a platform and a shaft, the fan blade being adjacent to the platform of the trunnion, the trunnion extending at least partially through the disk segment and being attached to the disk segment along a preload path using the first attachment system, the first attachment system and the second attachment system comprising first and second retention features, respectively, separate from the preload path, wherein, during operation of the fan assembly, the first attachment system retains the trunnion within the disk along a first load path, and Wherein, when the trunnion fails, the first retention feature and the second retention feature together retain the trunnion within the disk segment along a second load path, the first load path being different from the second load path.

2. The fan assembly according to claim 1, characterized in that: Wherein the first load path and the second load path are defined inside an outer surface of the disk segment of the disk.

3. The fan assembly according to claim 1, characterized in that: Wherein the first attachment system includes one or more bearings, one or more inserts arranged between the trunnion and the disk segment of the disk, one or more bearing supports and at least one coupling nut.

4. The fan assembly according to claim 3, characterized in that: wherein the first retaining feature of the first attachment system comprises a first protrusion of a first insert of the one or more inserts, the first protrusion being received within a corresponding first recess of the disk segment of the disk, and when the trunnion fails, the second load path is at least partially defined by the first protrusion of the first insert.

5. The fan assembly according to claim 4, characterized in that: Wherein the first insert is segmented into a plurality of segments, the plurality of segments being arranged together to form a generally annular or ring-like shape.

6. The fan assembly according to claim 5, characterized in that: Wherein the plurality of segments of the first insert are held together using retaining members.

7. The fan assembly according to claim 3, characterized in that: wherein the first retention feature of the first attachment system comprises a plurality of fasteners passing through the disc segment of the disc and secured to the one or more inserts, wherein the second load path is at least partially defined by the plurality of fasteners when the trunnion fails.

8. The fan assembly according to claim 3, characterized in that: wherein the second retention feature of the second attachment system comprises a second protrusion of a second insert, the second insert being configured to engage with a corresponding second protrusion of the shaft of the trunnion, wherein when the failure of the trunnion occurs, the second protrusion of the second insert engages the corresponding second protrusion of the shaft of the trunnion to keep the trunnion and the fan blade fixed within the disk segment of the disk.

9. The fan assembly according to claim 8, characterized in that: Wherein the second protrusion is a flange integrally formed with the second insert.

10. The fan assembly according to claim 8, characterized in that Wherein the second protrusion is defined by a plurality of fasteners extending through at least a portion of the trunnion.

Images