Metal blade beam retention system

Abstract

Systems, devices, articles of manufacture, and methods for attaching an airfoil to a hub to achieve pitch control actuation are disclosed, including: a beam that is part of a base of the airfoil; a trunnion coupled to the hub, the trunnion for receiving a beam; the beam is positioned relative to the trunnion such that a portion of the airfoil having a length greater than a diameter of the airfoil is retained within the trunnion to resist torque by the length of the airfoil retained within the trunnion; a split ring surrounding the inside of the trunnion, the split ring aligned with a notch on the airfoil, the notch on the airfoil being shaped to allow the split ring to move toward the airfoil of the trunnion; and a nut removably coupled to the trunnion, the nut positioned to prevent the split ring from moving away from the base of the trunnion.

Description

Technical Field

[0001] The present disclosure relates generally to an airfoil assembly, and more particularly, to an airfoil assembly. Background Art

[0002] A turbine engine, particularly a gas turbine engine or combustion turbine engine, is a rotary engine that extracts energy from an airflow that passes through a fan having a plurality of fan blades, then enters the engine through a series of compressor stages comprising pairs of rotating blades and stationary vanes, passes through a combustor, and then passes through a series of turbine stages comprising pairs of rotating blades and stationary vanes. The blades are mounted on a rotating disk, while the vanes are mounted on a stator disk.

[0003] During operation, air is drawn into the compressor section through the fan section, where it is compressed in the compressor and mixed with fuel in the combustor to produce hot combustion gases. These combustion gases flow downstream through the turbine stage, where the air expands and is discharged from the exhaust section. The expansion of the air in the turbine section is used to drive the rotating sections of the fan and compressor sections. The intake, compression, and expansion of the air are achieved in part by the rotation of various rotating blades mounted on the respective disks of the fan, compressor, and turbine sections. The rotation of the rotating blades creates mechanical stresses along various parts of the blades, particularly where the blades are mounted to the disks. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 is a schematic cross-sectional view of a turbine engine according to an exemplary embodiment of the present disclosure.

[0005] Figure 2 is applicable to Figure 1 Schematic diagram of an airfoil assembly within a turbine engine, the airfoil assembly including an airfoil, a trunnion, and a beam.

[0006] Figure 3 It is from Figure 2 Schematic cross-sectional view of the airfoil assembly viewed along section line III-III in , further illustrating a bifurcated tail portion of the beam having a set of branches defining an intermediate gap, the airfoil assembly having a wedge received within the intermediate gap.

[0007] Figure 4 is a schematic diagram of a pitch control assembly for holding a metal beam in accordance with the teachings of the present disclosure.

[0008] Figure 5 According to the teachings of this disclosure Figure 4 Schematic diagram of the first trunnion assembly retention system.

[0009] Figure 6 According to the teachings of this disclosure Figure 4 Schematic diagram of the second trunnion assembly retention system.

[0010] Generally, the same reference numerals will be used throughout the drawings and accompanying written description to refer to identical or similar components. The drawings are not necessarily drawn to scale. Rather, the thickness of layers or regions may be exaggerated in the drawings. Although the drawings show layers and regions with clear lines and boundaries, some or all of these lines and / or boundaries may be idealized. In practice, these boundaries and / or lines may be invisible, blurred, and / or irregular. DETAILED DESCRIPTION

[0011] Open rotor engines, or unducted fans, generate thrust without an engine casing. They draw in and compress air, which then passes through an open rotor. The rapid rotation of the propeller accelerates the air, generating thrust for flight. To achieve potential fuel savings, open rotor engines utilize fan blade pitch control mechanisms that allow for pitch control actuation of the fan blades during various phases of flight.

[0012] Various aspects of the present disclosure relate to an airfoil assembly for a turbine engine. The airfoil assembly includes an airfoil and a trunnion. In some examples, the airfoil is referred to as a lift-generating device. The base of the airfoil includes a beam, also known as the blade root, which provides structural support for the airfoil and bears flight loads. In some examples, the beam may be referred to as a support device. When the aircraft is on the ground, the beam bears the weight of the airfoil. The airfoil assembly, specifically the beam, is retained within the trunnion by wedges. In some examples, the trunnion is referred to as a device for receiving the airfoil. For ease of explanation, the present disclosure will be described with respect to an airfoil assembly for a turbine engine, specifically, a fan blade of the turbine engine. However, it will be understood that the various aspects of the present disclosure described herein are not limited thereto and may be generally applicable to other engines or other parts of a turbine engine. For example, the present disclosure may be applied to airfoil assemblies in other engines or vehicles and may be used to provide benefits in industrial, commercial, and residential applications.

[0013] As used herein, the term "metallic" refers to a material comprising a metal, such as, but not limited to, titanium, iron, aluminum, stainless steel, and nickel alloys. A metallic material or alloy may be a combination of at least two or more elements or materials, at least one of which is a metal.

[0014] As used herein, "include" and "comprising" (and all forms and tenses thereof) are open-ended terms. Thus, whenever a claim uses any form of "include" or "comprising" (e.g., includes, comprises, having, etc.) as an introductory phrase or in any type of claim recitation, it should be understood that additional elements, terms, etc. may be present without exceeding the scope of the corresponding claim or recitation. As used herein, when the phrase "at least" is used as a transitional term, such as in the introductory phrase of a claim, it is open-ended like "include" and "comprising." The term "and / or," for example, when used in the form "A, B, and / or C," refers to any combination or subset of A, B, and C, such as (1) A only, (2) B only, (3) C only, (4) A and B, (5) A and C, (6) B and C, or (7) A and B and C. In the context of describing structures, components, items, objects, and / or things herein, the phrase "at least one of A and B" is intended to refer to embodiments that include any of the following: (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, in the context of describing structures, components, items, objects, and / or things herein, the phrase "at least one of A or B" is intended to refer to embodiments that include any of the following: (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. In the context of describing the performance of a process, instruction, act, activity, etc. herein, the phrase "at least one of A and B" is intended to refer to embodiments that include any of the following: (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, in the context of describing the performance of a process, instruction, act, activity, etc. herein, the phrase "at least one of A or B" is intended to refer to embodiments that include any of the following: (1) at least one A, (2) at least one B, or (3) at least one A and at least one B.

[0015] As used herein, singular references (e.g., "a," "an," "first," "second," etc.) do not exclude plural references. The term "a" or "an" object herein refers to one or more of that object. The terms "a" (or "an"), "one or more," and "at least one" are used interchangeably herein. Furthermore, although listed separately, multiple devices, elements, or actions may be implemented by, for example, the same entity or object. Additionally, although individual features may be included in different examples or claims, these features may be combined, and inclusion in different examples or claims does not mean that a combination of features is not feasible and / or without advantage.

[0016] As used herein, unless otherwise specified, the term "above" describes the relationship of two components relative to the Earth. A first component is above a second component if at least a portion of the second component is located between the Earth and the first component. Similarly, as used herein, a first component is "below" a second component when the first component is closer to the Earth than the second component. As described above, a first component can be above or below a second component, with one or more of the following: with another component in between, without another component in between, with the first and second components in contact, or with the first and second components not in direct contact with each other.

[0017] As used herein, connection references (eg, "attached," "coupled," "adjoined," "connected," and "joined"),

[0018] Unless otherwise indicated, connective references may include intermediate members between the elements involved and / or relative movement between such elements. Therefore, connective references do not necessarily imply that two elements are directly connected and / or in fixed relation to each other. As used herein, the statement that any component is "in contact with" another component is defined to mean that there are no intermediate components between the two components.

[0019] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, with respect to fluid flow, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction to which the fluid is flowing. However, as used herein, the terms "upstream" and "downstream" may also refer to the flow of an electrical current.

[0020] Unless otherwise expressly stated, descriptors such as "first," "second," and "third" as used herein do not imply or indicate any priority, physical order, list arrangement, and / or any form of sorting, but are merely used as labels and / or arbitrary names to distinguish elements to facilitate understanding of the disclosed examples. In some examples, the descriptor "first" may be used to refer to an element in the detailed description, while a different descriptor (such as "second" or "third") may be used to refer to the same element in the claims. In this case, it should be understood that these descriptors are only used to clearly distinguish these elements in the discussion context (e.g., claims), as these elements may share the same name in other cases.

[0021] As used herein, the words "substantially" and "approximately" are used to modify the object / value they describe to account for possible deviations in real-world applications. For example, one of ordinary skill in the art will understand that due to manufacturing tolerances and / or other real-world imperfections, dimensions may not be exact values, and "substantially" and "approximately" may be used to modify these dimensions. For example, unless otherwise specified herein, "substantially" and "approximately" may indicate that these dimensions may be within a tolerance range of + / - 10%.

[0022] Some turbine engines may include a variable-pitch airfoil that can be selectively rotated to adjust or otherwise modify the flow of fluid through the variable-pitch airfoil. The variable-pitch airfoil is movable through the use of a trunnion and a beam. The trunnion rotates about an axis of rotation, thereby rotating the beam and the variable-pitch airfoil. The trunnion is coupled to or otherwise formed with the beam, which serves as the base of the airfoil.

[0023] Figure 1 1 is a schematic cross-sectional view of a turbine engine 110 for an aircraft. Turbine engine 110 has a generally longitudinally extending axis or centerline 112 extending from a forward end 114 to an aft end 116. Turbine engine 110 includes, in downstream series flow relationship: a fan section 118 including a fan 120; a compressor section 122 including a supercharger or low-pressure (LP) compressor 124 and a high-pressure (HP) compressor 126; a combustion section 128 including a combustor 130; a turbine section 132 including an HP turbine 134 and an LP turbine 136; and an exhaust section 138.

[0024] The fan section 118 includes a fan casing 140 surrounding the fan 120. The fan 120 includes a plurality of fan blades 142 arranged radially about the engine centerline 112. The HP compressor 126, the combustor 130, and the HP turbine 134 form the engine core 144 of the turbine engine 110, which produces combustion gases. The engine core 144 is surrounded by a core casing 146, which can be coupled to the fan casing 140.

[0025] An HP shaft or spool 148 is coaxially disposed about the engine centerline 112 of the turbine engine 110, drivingly connecting the HP turbine 134 with the HP compressor 126. An LP shaft or spool 150 is coaxially disposed about the engine centerline 112 of the turbine engine 110 and is located within the larger diameter annular HP spool 148, drivingly connecting the LP turbine 136 with the LP compressor 124 and the fan 120. The spools 148, 150 are rotatable about the engine centerline and are coupled to a plurality of rotatable elements, collectively defining a rotor 151.

[0026] The LP compressor 124 and the HP compressor 126 each include a plurality of compressor stages 152, 154, in each of which a set of compressor blades 156, 158 rotate relative to a corresponding set of stationary compressor vanes 160, 162 to compress or boost the fluid flow passing through the stage. Within a single compressor stage 152, 154, the plurality of compressor blades 156, 158 may be arranged in an annular pattern and may extend radially outward from the blade platform relative to the engine centerline 112 to the blade tip, with the corresponding stationary compressor vanes 160, 162 located upstream and adjacent to the rotating compressor blades 156, 158. Note that Figure 1 The numbers of blades, vanes, and compressor stages shown are chosen for illustration purposes only; other numbers are possible.

[0027] The compressor blades 156, 158 of the compressor stage may be mounted to (or integral with) a disk 161 mounted on a respective one of the HP and LP spools 148, 150. The stationary compressor vanes 160, 162 of the compressor stage may be mounted on the core housing 146 in a circumferential arrangement.

[0028] The HP turbine 134 and the LP turbine 136 each include a plurality of turbine stages 164, 166, in each of which a set of turbine blades 168, 170 rotate relative to a corresponding set of stationary turbine vanes 172, 174 (also referred to as nozzles) to extract energy from the fluid flow passing through the stage. Within a single turbine stage 164, 166, the plurality of turbine blades 168, 170 may be arranged in an annular pattern and may extend radially outward relative to the engine centerline 112, with the corresponding stationary turbine vanes 172, 174 located upstream and adjacent to the rotating turbine blades 168, 170. Note that Figure 1 The number of blades, buckets, and turbine stages shown in FIG are chosen for illustrative purposes only; other numbers are possible.

[0029] Turbine blades 168, 170 included in the turbine stage may be mounted on disks 171 mounted on respective ones of the HP and LP spools 148, 150. Turbine buckets 172, 174 included in the compressor stage may be mounted on the core housing 146 in a circumferential arrangement.

[0030] In contrast to the rotor portion, the stationary portion of the turbine engine 110, such as the stationary blades 160, 162, 172, 174 in the compressor section 122 and the turbine section 132, may also be individually or collectively referred to as a stator 163. Therefore, the stator 163 may refer to the combination of all non-rotating elements in the turbine engine 110.

[0031] During operation, the airflow exiting fan section 118 is split so that a portion of the airflow is directed into LP compressor 124. LP compressor 124 then supplies a pressurized airflow 176 to HP compressor 126, which further pressurizes the air. Pressurized airflow 176 from HP compressor 126 is mixed with fuel and ignited in combustor 130, thereby producing combustion gases. HP turbine 134 extracts a portion of the work from these gases to drive HP compressor 126. The combustion gases are exhausted into LP turbine 136, which extracts additional work to drive LP compressor 124. The exhaust gases are ultimately exhausted from turbine engine 110 through exhaust section 138. The drive of LP turbine 136 drives LP spool 150, which rotates fan 120 and LP compressor 124.

[0032] A portion of pressurized airflow 176 can be diverted from compressor section 122 as bleed air 177. Bleed air 177 can be diverted from pressurized airflow 176 and supplied to engine components requiring cooling. The temperature of pressurized airflow 176 entering combustor 130 is elevated above the temperature of the bleed air. Bleed air 177 can be used to reduce the temperature of core components downstream of combustor 130. Bleed air 177 can also be used by other systems.

[0033] The remainder of the airflow, referred to as bypass airflow 178, bypasses the LP compressor 124 and the engine core 144 and is discharged from the turbine engine 110 through a row of stationary blades, more specifically, through an outlet guide vane assembly 180 at the fan exhaust side 18, which includes a plurality of airfoil guide vanes 182. More specifically, a row of circumferentially arranged and radially extending airfoil guide blades 182 is used adjacent the fan section 118 to exert some directional control on the bypass airflow 178.

[0034] Some of the air provided by the fan 120 can bypass the engine core 144 and be used to cool certain parts of the turbine engine 110, particularly hot parts, and / or to cool or power other parts of the aircraft. In the context of a turbine engine, the hot parts of the engine are generally located downstream of the combustor 130, particularly the turbine section 132, with the HP turbine 134 being the hottest part because it is directly downstream of the combustion section 128. Other sources of cooling fluid can be, but are not limited to, exhaust fluid from the LP compressor 124 or the HP compressor 126.

[0035] Figure 2 is applicable to Figure 1FIG2 is a schematic diagram of an airfoil assembly 230 within turbine engine 110. Airfoil assembly 230 may include an airfoil 232, which may be any suitable airfoil within turbine engine 110. As non-limiting examples, airfoil 232 may be a blade from among the plurality of fan blades 142, or a blade from among the compressor blades 156, 158, or the turbine blades 168, 170. It is contemplated that airfoil 232 may be a blade, bucket, airfoil, or other component of any turbine engine, such as, but not limited to, a gas turbine engine, a turboprop engine, a turboshaft engine, a ducted turbofan engine, an unducted turbofan engine, or an open rotor turbine engine.

[0036] Airfoil 232 may include a wall 238 defining an interior 248. Wall 238 may extend between a leading edge 244 and a trailing edge 246, thereby defining a chord-wise direction (C). Wall 238 may also extend between a root 240 and a tip of fan blade 242, thereby defining a span-wise direction (S). Wall 238 may be a composite wall made from one or more layers of composite material. The one or more layers of material may be applied during the same or different stages of manufacturing airfoil 232.

[0037] As a non-limiting example, the wall 238 may include at least a polymer matrix composite (PMC) portion or a polymer portion. A polymer matrix composite may include, but is not limited to, a thermoset (epoxy, phenolic) or thermoplastic (polycarbonate, polyvinyl chloride, nylon, acrylic) matrix and embedded glass fiber, carbon fiber, steel fiber, or Kevlar. TM fiber.

[0038] Airfoil assembly 230 may further include a beam 236 and a trunnion 234. Beam 236 may extend into interior 248, or beam 236 may be formed as part of or extend from root 240. Beam 236 may be operably coupled to trunnion 234. Beam 236 may be made of any suitable material, such as, but not limited to, a composite material. For example, beam 236 may be a metal composite. Trunnion 234 may be made of any suitable material, such as, but not limited to, a metal material or a composite material. It should be understood that the term composite material may also include metal, but having a composite structure (e.g., a metal matrix composite). In the case of composite materials, beam 236 and / or trunnion 234 may be any suitable composite material, such as a composite material, a laminated skin, a woven or braided composite material, or any other suitable composite material.

[0039] The airfoil 232 has a span length (L) measured along the spanwise direction (S) from the root 240 at 0% of the span length (L) to the tip of the fan blade 242 at 100% of the span length (L). The entirety of the beam 236 may be located at a position less than 20% of the span length (L). Alternatively, the beam 236 may extend beyond 20% of the span length (L).

[0040] During operation of airfoil assembly 230, trunnion 234 can rotate about pitch axis (Pax) in a rotational direction (Rd). Because beam 236 couples trunnion 234 to airfoil 232, rotation of trunnion 234 in the rotational direction (Rd) causes airfoil 232 to rotate about pitch axis (Pax). This rotation can be used to control the pitch of airfoil assembly 230, such that airfoil assembly 230 is defined as a variable pitch airfoil assembly. Figure 4 ) is actuated in axial motion to provide twisting to control the pitch of the airfoil assembly 230. The pitch of the airfoil assembly 230 may be adjusted based on the turbine engine (e.g., Figure 1 The arm assembly 402 is actuated in a variety of ways, such as by a counterweight, a piston, etc.

[0041] Figure 3 It is from Figure 2 Schematic cross-sectional view of the airfoil assembly 230 viewed along the section line III-III in FIG. For ease of illustration, the airfoil 232 ( Figure 2 ) is removed from the airfoil assembly 230 .

[0042] The trunnion 334 includes a wall 363, the inner surface 362 of which at least partially defines a flared socket 364 of the trunnion 334. The flared socket 364 extends between an open top 370 and a bottom 368. The beam 336 extends through the open top 370 and into the interior 248. The bottom 368 can be an open bottom or a sealed / closed bottom. The flared socket 364 can have a variety of shapes, including rectangular or, as shown, a tapered shape having at least one flared cross-section.

[0043] The beam extends along a centerline axis 350 and terminates at a first end 360 within a flared socket 364. The beam 336 includes a forked tail portion 352 with a set of branches. As a non-limiting example, the set of branches includes a first branch 354 and a second branch 356 defining an intermediate gap 358 therebetween. The intermediate gap 358 extends axially into the beam 336 and terminates at an apex 359. The width of the first branch 354 and the width of the second branch 356 vary along the axial extent of the forked tail portion 352. As a non-limiting example, each branch in the set of branches includes a maximum width (W1) and a minimum width (W2), which are defined as the maximum and minimum radial distances, respectively, between the intermediate gap 358 and a portion of the forked tail portion 352 radially outward from the intermediate gap 358. The maximum width (W1) may be located axially closer to the first end 360 than the minimum width (W2). As a non-limiting example, the maximum width (W1) may be at the first end 360, while the minimum width (W2) may be axially closest to the apex 359. The beam 336 may be symmetrical or asymmetrical about the centerline axis 350.

[0044] The wedge 372 can be received within the intermediate gap 358. The wedge 372 can be maintained in place within the intermediate gap 358 by frictional contact. Alternatively, the wedge 372 can be coupled to the beam 336 by any suitable connection method, such as, but not limited to, bonding, curing, welding, adhering, fastening, etc. The wedge 372 can be made of any suitable material. As a non-limiting example, the wedge 372 can include a metal material or a composite material. As a non-limiting example, the airfoil assembly 330 can include a beam 336 including a composite material, a trunnion 334 including a metal material, and a wedge 372 including a metal material. As shown, the wedge 372 is solid. However, it will be understood that the interior of the wedge 372 or at least a portion of the wedge 372 can be hollow.

[0045] The wedge 372 is used to retain the beam 336 within the trunnion 334. When the wedge 372 is received within the intermediate gap 358, the wedge 372 pushes the beam 336, and specifically the forked tail 352, radially outward relative to the centerline axis 350, such that the beam 336 maintains contact with the inner surface 362 of the trunnion 334. Although a gap is shown between the wedge 372 and the beam 336, it will be appreciated that the wedge 372 can be sized to fill the entire intermediate gap 358.

[0046] Figure 4 4 is a schematic diagram of a pitch control assembly for retaining a metal beam of an airfoil in accordance with the teachings of the present disclosure. The pitch control assembly includes an arm assembly 402, a trunnion 404, a hub 406, a bearing 408, an airfoil 410, a beam 412, and a trunnion assembly retention system 414.

[0047] The arm assembly 402 is connected to a trunnion 404, which is located inside a hub 406. The trunnion 404 is able to rotate due to the presence of a bearing 408 between the trunnion 404 and the hub 406. The trunnion is a retention system for an airfoil 410 having a beam 412 that is held in place by an assembly referred to as a trunnion assembly retention system 414 ( Figure 5 There is a description in ).

[0048] During operation, Figure 4 The arm assembly 402 in FIG. 404 rotates the trunnion 404 within the hub 406, thereby controlling the pitch of the airfoil 410. The airfoil 410 is connected to the trunnion 404 by a beam 412, which is held in place by a trunnion assembly retention system 414. The trunnion assembly retention system 414 disclosed herein enables the removability of the airfoil 410.

[0049] Figure 5 According to the teachings of this disclosure Figure 4 FIG4 is a schematic diagram of an example first trunnion assembly retention system 414. First trunnion assembly retention system 414 includes beam 412, trunnion 404, a split ring 504 consisting of at least two parts, and a locknut 506. Beam 412 has a retaining groove 503 defined therein for locking beam 412 in place. In some examples, retaining groove 503 may be referred to as a retaining device. In certain configurations, trunnion 404 may include an optional auxiliary retaining groove 505 for retaining split ring 504.

[0050] During assembly, the trunnion assembly retention system 414 allows the beam 412 to slide into the trunnion 404 (e.g., a receiving device) until it contacts the base of the trunnion 404. Once the beam 412 is in place (e.g., in contact with the bottom of the trunnion 404), the split ring 504 is placed around the beam 412 and received inside the trunnion 404. The split ring 504 slides down the trunnion 404 toward the base of the trunnion 404 until it reaches the retaining groove 503. The split ring 504 slides into the retaining groove 503 (e.g., a retaining device), which prevents the split ring 504 from sliding off the base of the trunnion 404 while allowing the split ring 504 to secure the beam 412 within the trunnion 404. Figure 5 As shown in the example of FIG, the trunnion 404 includes a threaded portion, and the locknut 506 is threadedly connected to the trunnion 404. Figure 5 In the example shown, the trunnion 404, the beam 412, the split ring 504, and the locknut 506 are arranged in rotational symmetry about the centerline 508. Any metal components of the assembly may be made of, for example, titanium, stainless steel, or nickel.

[0051] During operation, the trunnion assembly retention system 414 secures the beam 412 to the trunnion 404 using the split ring 504 and the locknut 506. Figure 4 As shown, the trunnion assembly retention system 414 removably secures an airfoil 410 (e.g., a lift-generating device) to the hub 406. The airfoil 410 is coupled to a beam 412 that slides into the trunnion 404. Figure 4 As shown, trunnion 404 is coupled to hub 406 . Figure 5 4. The diagram shows how the split ring 504 slides around the beam 412 and is located inside the trunnion 404. The split ring 504 is able to slide along the length of the trunnion 404. In some examples, the split ring 504 is referred to as a coupling device. A retaining groove 503 is provided on the beam 412, and its shape is designed to allow the split ring 504 to be accommodated in the retaining groove 503 so that the split ring 504 can only move in a single direction toward the base of the trunnion 404 (for example, the retaining groove 503 prevents the split ring 504 from moving away from the base of the hub 406). A lock nut 506 is threaded inside the trunnion 404 to apply pressure, provide a radial preload to the split ring 504, and limit the outward movement of the split ring 504. Therefore, the lock nut 506 is also referred to as a nut or a limiting device. The split ring 504 holds the beam (and accordingly the airfoil 410, Figure 5 404). The split ring 504 further secures the beam 412 toward the base of the trunnion 404. The split ring 504 helps ensure that the length L 510 of the beam 412 is seated in the trunnion 404. The length L 510 of the portion of the beam 412 seated in the hub 406, secured by the split ring 504, is at least greater than the diameter of the airfoil 410 to balance the bending moment reaction force. By threading the locknut 506 down the trunnion 404 to hold the components in place, a radial preload is applied to the locknut 506, inducing a radial reaction force at the inner diameter of the trunnion 404.

[0052] Figure 6 According to the teachings of this disclosure Figure 4 FIG2 is a schematic diagram of an exemplary second trunnion assembly retention system 601. Second trunnion assembly retention system 601 includes trunnion 404, beam 412, split ring 604, and locknut 606. Beam 412 defines a first retaining groove 603 for locking airfoil 410 in place. Trunnion 404 also defines a second retaining groove 605 as a secondary securing mechanism to prevent loosening. Trunnion 404, beam 412, split ring 604, and locknut 606 are arranged rotationally symmetrically about centerline 608.

[0053] During assembly, the second trunnion assembly retaining system 601 allows the beam 412 to slide into the trunnion 404. Once the beam 412 is in place, the split ring 604 is placed around the trunnion 404. The split ring is positioned along the retaining wall toward the Figure 4 The ear shaft 404 in the middle slides downward until it reaches the first retaining groove 603. The split ring 604 slides into the first retaining groove 603, which prevents the split ring 604 from sliding off the ear shaft 404 (and subsequent Figure 4The hub 406 in the trunnion 404 can slide off, and can allow the split ring 604 to more firmly fix the airfoil 410 inside the trunnion 404. A second retaining groove 605 is shown in this example to prevent the split ring 604 from loosening. Figure 6 As shown in the example of , the trunnion 404 includes a threaded portion, and the locknut 606 is threadedly connected to the trunnion 404.

[0054] During operation, Figure 6 These components are used to removably secure the airfoil 410 (e.g., a lift-generating device) to the Figure 4 The trunnion 404 (e.g., receiving device) in the hub 406 is mounted on the airfoil 410. The airfoil 410 slides into the trunnion 404. The split ring 604 (e.g., coupling device) slides around the trunnion 404 and can slide along the length of the trunnion 404. The airfoil 410 is provided with a first retaining groove 603 (e.g., retaining device or fixing means), which is shaped to allow the split ring to be received in the first retaining groove 603 so that the split ring 604 can only move in one direction toward the hub 406 (e.g., the first retaining groove 603 prevents the split ring 604 from moving out of the hub 406). Figure 4 404). A locknut 606 (e.g., a restraining device) is threaded onto the trunnion 404 to apply pressure to the split ring 604 and restrict outward movement of the split ring 604. The split ring 604 further secures the airfoil 410 and beam 412 within the trunnion 404 (and subsequently Figure 4 The split ring 604 helps ensure that the length L 610 of the airfoil 410 is seated in the trunnion. The length L 610 of the portion of the airfoil 410 that is seated in the trunnion 404, secured by the split ring 604, is at least greater than the diameter of the airfoil 410 to balance the bending moment reaction force. By threading the locknut 606 down the trunnion 404 to hold the components in place, a radial preload is provided to the locknut 606. Figure 4 A radial reaction force is induced at the inner diameter of the middle trunnion 404 .

[0055] In summary, it can be appreciated that example systems, apparatus, articles of manufacture, and methods have been disclosed that allow fan blades to be retained and removed from a beam and hub. Improved retention is achieved due to the radial preload provided by the locknut, which positions the blade based on a specific ratio of blade length to blade diameter. This improved positioning provides improved bending moment reaction.

[0056] Further aspects of the present disclosure are provided by the subject matter of the following clauses:

[0057] An exemplary apparatus for attaching an airfoil to a hub includes a trunnion coupled to the hub, the trunnion receiving a beam of the airfoil, the beam forming a base of the airfoil, the beam positioned relative to the trunnion such that a portion of the beam having a length greater than a diameter of the airfoil is retained within the trunnion to resist moments due to the length of the airfoil retained within the trunnion; a split ring surrounding an inside of the trunnion, the split ring aligned with a notch on the airfoil, the notch shaped to allow movement of the split ring toward the base of the trunnion; and a nut removably coupled to the trunnion, the nut positioned relative to the split ring to apply pressure to the split ring to limit movement of the beam relative to the trunnion.

[0058] The exemplary apparatus of any preceding clause, wherein the airfoil has a retaining groove for retaining the split ring.

[0059] The exemplary apparatus of any preceding clause, wherein the trunnion has a retaining groove for retaining the split ring.

[0060] The exemplary apparatus of any preceding clause, wherein the split ring comprises at least two parts.

[0061] The exemplary device of any preceding clause, wherein the trunnion is made of at least one of titanium, stainless steel, or nickel.

[0062] The exemplary apparatus of any preceding clause, wherein the pressure applied to the split ring by the nut is a radial preload that induces a radial reaction force at the inner diameter of the trunnion.

[0063] The example apparatus of any preceding clause, wherein the trunnion is coupled to an arm that controls the pitch of the airfoil by rotating the trunnion within the hub.

[0064] An exemplary apparatus for receiving and coupling an airfoil to a hub in an engine includes a trunnion coupled to the hub for receiving a beam of the airfoil; a split ring surrounding an inside of the trunnion; and a nut removably coupled to the trunnion, the nut being further from a base of the trunnion than the split ring.

[0065] The exemplary apparatus of any preceding clause, wherein the trunnion has a retaining groove for retaining the split ring.

[0066] The exemplary apparatus of any preceding clause, wherein the split ring comprises at least two parts.

[0067] The exemplary device of any preceding clause, wherein the trunnion is made of at least one of titanium, stainless steel, or nickel.

[0068] The exemplary apparatus of any preceding clause, wherein the split ring is shaped to fit within a retaining groove on the airfoil.

[0069] The exemplary apparatus of any preceding clause, wherein the nut applies pressure to the split ring to prevent the split ring from sliding off the base of the trunnion, the pressure resulting from a radial preload created at the inner diameter of the trunnion.

[0070] The exemplary apparatus of any preceding clause, wherein the trunnion is coupled to an actuator arm that controls the pitch of the airfoil by rotating the trunnion within the hub.

[0071] An exemplary apparatus includes first means for receiving a second means for generating lift, third means for coupling the second means to the first means, and fourth means for limiting removal of the third means from the first means, the fourth means being removably coupled to the first means.

[0072] The exemplary device of any preceding clause, wherein the second device is shaped to fit within the retaining device of the first device.

[0073] The exemplary device of any preceding clause, wherein the second device is shaped to fit within a retaining device in the second device.

[0074] The exemplary apparatus of any preceding clause, wherein the second apparatus comprises at least two parts.

[0075] The exemplary device of any preceding clause, wherein the third device is made of at least one of titanium, stainless steel, or nickel.

[0076] The exemplary apparatus of any preceding clause, further comprising a fifth means for rotating the first means to control a pitch associated with generating the second means. The following claims are incorporated herein by reference. Although certain exemplary systems, apparatus, articles of manufacture, and methods have been disclosed herein, the scope of this patent is not limited thereto. On the contrary, this patent covers all systems, apparatus, articles of manufacture, and methods fairly falling within the scope of the claims herein.

Claims

1. A device for attaching an airfoil to a hub, characterized in that The device comprises: a trunnion coupled to the hub; a beam forming a base of the airfoil, the beam being positioned relative to the trunnion such that a portion of the beam having a length greater than a diameter of the airfoil is retained within the trunnion to resist moments by the length of the airfoil retained within the trunnion; a split ring surrounding the inside of the trunnion, the split ring being aligned with a notch on the airfoil, the notch on the airfoil being shaped to allow the split ring to move toward the base of the trunnion; and A nut is removably coupled to the trunnion, the nut being positioned relative to the split ring to apply pressure to the split ring to limit movement of the beam relative to the trunnion.

2. The device according to claim 1, characterized in that in, The airfoil defines a retaining groove for retaining the split ring.

3. The device according to claim 1, characterized in that in, The trunnion defines a retaining groove for retaining the split ring.

4. The device according to claim 1, characterized in that in, The split ring comprises at least two parts.

5. The device according to claim 1, characterized in that in, The trunnion is made of at least one of titanium, stainless steel or nickel.

6. The device according to claim 1, characterized in that in, The pressure applied to the split ring by the nut is a radial preload that causes a radial reaction force at the inner diameter of the trunnion.

7. The device according to claim 1, characterized in that in, The trunnion is coupled to an arm that controls the pitch of the airfoil by rotating the trunnion within the hub.

8. An apparatus for receiving and coupling an airfoil to a hub in an engine, characterized in that The device comprises: a trunnion coupled to the hub, the trunnion for receiving a beam of the airfoil; a split ring surrounding an inside of the trunnion; and A nut is removably coupled to the trunnion, the nut being positioned further from a base of the trunnion than the split ring.

9. The device according to claim 8, characterized in that in, The trunnion defines a retaining groove for retaining the split ring.

10. The device according to claim 8, characterized in that in, The split ring comprises at least two parts.

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