Inner shroud damper for vibration reduction

Abstract

An inner shroud damper for a gas turbine engine includes at least one carrier including a joint coupled to an inner shroud, the at least one carrier having a first side and a second side, and at least one mass damper coupled to the at least one carrier.

Description

Technical Field

[0001] The present disclosure relates generally to gas turbines and, more particularly, to inner shroud dampers for vibration reduction. Background Art

[0002] A gas turbine engine generally includes an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section in a sequential flow order. In operation, air enters the inlet section and flows to the compressor section, where one or more axial compressors progressively compress the air until it reaches the combustion section, thereby producing combustion gases. The combustion gases flow from the combustion section through a hot gas path defined within the turbine section, and then exit the turbine section via the exhaust section. Summary of the invention

[0003] Methods, apparatus, systems, and articles of manufacture for reducing turbine engine vibrations are disclosed.

[0004] Certain examples provide an apparatus comprising: at least one arm including a joint to couple to an inner shroud, the at least one arm having a first side and a second side; and at least one mass damper coupled to the at least one arm.

[0005] Certain examples provide a gas turbine engine including an inner shroud, a seal box coupled to the inner shroud, and an inner shroud damper including at least one arm disposed within the seal box and at least one mass damper coupled to the at least one arm, the at least one arm including a joint coupled to the inner shroud.

[0006] Certain examples provide an apparatus that includes means for coupling at least one arm to an inner shroud and means for damping engine vibrations, the means for damping coupled to the at least one arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 An example gas turbine engine is shown.

[0008] Figure 2 Shows Figure 1 An example cross-sectional side view of a high pressure compressor of a turbofan engine is shown in .

[0009] Figure 3 An example cross-sectional view of a first example inner shroud damper is shown.

[0010] Figure 4A and 4B Shows Figure 3 An example perspective view of a first example inner shroud damper.

[0011] Figure 5AAn example cross-sectional view of a second example inner shroud damper is illustrated.

[0012] Figure 5B Picture shows Figure 5A An example perspective view of a second example inner shroud damper.

[0013] The drawings are not drawn to scale. On the contrary, the thickness of the layer or region can be magnified in the drawings. Although the layers and regions with clear lines and boundaries are shown in the figures, some or all of these lines and / or boundaries may be idealized. In fact, the boundaries and / or lines may be unobservable, mixed and / or irregular. Generally, the same reference numerals will be used throughout the drawings and the accompanying written description to refer to the same or similar parts. As used in this patent, it is stated that any part (e.g., layer, film, region, zone or plate) is in any way on (e.g., positioned on, located on, set on or formed on, etc.) another part, indicating that either the referenced part is in contact with another part, or the referenced part is above another part, and one or more intermediate parts are located between them. As used herein, unless otherwise specified, connection references (e.g., attachment, connection, connection and engagement) may include intermediate members between elements referenced by the connection reference and / or relative movement between those elements. Therefore, connection references do not necessarily infer that two elements are directly connected and / or are in a fixed relationship with each other. As used herein, stating that any part is "in contact with" another part is defined to mean that there is no intermediate part between the two parts. DETAILED DESCRIPTION

[0014] Engine and component vibrations occur during normal engine operation. For example, forces acting on one or more airfoils (e.g., blades, vanes, etc.) during engine operation may cause one or more airfoils to vibrate an undesirable amount, thereby introducing stress and ultimately wear on one or more airfoils. Component vibration mode responses to engine vibrations or other sources include airfoil mode responses (e.g., one airfoil is vibrating), soldier mode responses (e.g., one or more airfoils attached to a shroud vibrate together), etc. Vibration mode responses may eventually lead to airfoil wear (e.g., trunnion cracking, trunnion locking, etc.). There is a constant need to reduce the vibration response of components. Certain examples provide an inner shroud damper that absorbs relatively high energy and acts as an anti-mode for certain vibration frequencies, thereby improving the durability of one or more airfoils and an associated engine.

[0015] In the detailed description below, reference is made to the accompanying drawings which form a part thereof, and in which specific examples that can be put into practice are shown by way of example. These examples are described in sufficient detail to enable those skilled in the art to practice the subject matter, and it should be understood that other examples can be utilized. Therefore, the following detailed description is provided to describe example embodiments, and is not to be considered as limiting the scope of the subject matter described in this disclosure. Certain features from the different aspects described below can be combined to form yet new aspects of the subject matter discussed below.

[0016] Descriptors "first", "second", "third", etc. are used herein to identify multiple elements or components that can be referred to separately. Unless otherwise specified or understood from the context of their use, such descriptors are not intended to confer any meaning of priority, physical order or arrangement in a list, or time ordering, but are merely used as labels to refer to multiple elements or components, respectively, to facilitate understanding of the disclosed examples. In some examples, the descriptor "first" can be used to refer to an element in the detailed description, while the same element can be referred to in the claims by different descriptors such as "second" or "third". In such cases, it should be understood that such descriptors are only used to facilitate reference to multiple elements or components.

[0017] The terms "upstream" and "downstream" refer to relative directions with respect to the flow of fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing. As used herein, "vertical" refers to a direction perpendicular to the ground. As used herein, "horizontal" refers to a direction parallel to the centerline of the gas turbine engine 100. As used herein, "lateral" refers to a direction perpendicular to the axial vertical direction (e.g., entering and leaving the engine). Figure 1 , 2 etc. plane).

[0018] Various terms are used herein to describe the orientation of features. As used herein, the orientation of features, forces, and moments are described with reference to the axial direction, radial direction, and circumferential direction of the vehicle associated with the features, forces, and moments. In general, the figures are labeled with a set of axes, including an axial axis A, a radial axis R, and a circumferential axis C.

[0019] "Include" and "comprising" (and all their forms and tenses) are used herein as open-ended terms. Thus, whenever a claim adopts any form of "include" or "comprising" (e.g., includes, contains, has, etc.) as a preamble 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 preamble of a claim, it is open-ended in the same manner as the terms "include" and "comprising" are open-ended. The term "and / or" when used in the form of, for example, A, B, and / or C, refers to any combination or subset of A, B, C, such as (1) A alone, (2) B alone, (3) C alone, (4) A and B, (5) A and C, (6) B and C, and (7) A and B and C. As used herein in the context of describing structures, components, items, objects, and / or things, the phrase "at least one of A and B" is intended to refer to any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects, and / or things, the phrase "at least one of A or B" is intended to refer to any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities, and / or steps, the phrase "at least one of A and B" is intended to refer to any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities, and / or steps, the phrase "at least one of A or B" is intended to refer to any of (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.

[0020] As used herein, singular references (e.g., "a", "a", "first", "second", etc.) do not exclude the plural. As used herein, the term "a" or "an" entity refers to one or more of that entity. The terms "a" (or "a"), "one or more" and "at least one" may be used interchangeably herein. In addition, although listed separately, multiple devices, elements or method actions may be implemented by, for example, a single unit or processor. In addition, although individual features may be included in different examples or claims, these may be combined, and inclusion in different examples or claims does not mean that the combination of features is not feasible and / or not advantageous.

[0021] The gas turbine engine includes multiple rows of buckets, multiple rows of rotor blades, etc. In some examples, the buckets of the gas turbine engine are variable stator buckets ("VSV"), which allow individual stator buckets to rotate about their respective axes (e.g., radial axes). In some existing designs, the VSV and shroud assembly include a 360-degree segment, two 180-degree segments, or other number of segments that form a single row of stators associated with a particular stage of the compressor. Although the examples disclosed herein are described with reference to a stator in a compressor, the examples disclosed herein may be applied to stators in any section of a gas turbine engine.

[0022] In some examples, the rotation of the VSV is controlled by a trunnion disposed within the shroud and / or a sealed box below the shroud and VSV. As used herein, a "trunnion" is a part and / or feature that allows parts and / or features to be supported thereon and / or rotated thereby. In some prior art, tests have shown that the trunnion may have unfavorable cracking and fatigue, depending on the vibration response mode (e.g., soldier mode response, etc.). In view of the shroud end mass, the vibration response during engine operation is based at least in part on the conflicting design parameters of the VSV (e.g., stiffness, durability, etc.). This response can cause the trunnion to lock (e.g., stop rotating) within the sealed box, which can reduce engine performance and fatigue the VSV. For example, during a particular vibration response, the cylindrical shape of the trunnion may deform in a manner that causes three points of the trunnion to contact the shroud, which prevents the trunnion from rotating, thereby locking the VSV. In addition, trunnion locking can cause fatigue and cracking of the cylindrical trunnion.

[0023] Based on the reduction of engine vibration, the examples disclosed herein can reduce the undesirable effects caused by these deformations in the engine. For example, by coupling an internal mass damper to an internal shroud of a gas turbine engine, the vibration response is mitigated. The internal mass damper may include one or more arms, one or more mass dampers, and the like.

[0024] Reference will now be made in detail to examples of the present invention, one or more of which are illustrated in the accompanying drawings. Each example is provided to explain the present invention, not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as part of one example may be used together with another example to produce yet another example. Therefore, the present invention is intended to encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0025] Figure 1 1 is a schematic cross-sectional view of a prior art turbofan-type gas turbine engine 100 (“turbofan engine 100”). Figure 1As shown, turbofan engine 100 defines a longitudinal or axial centerline axis 102 extending therethrough for reference. Generally, turbofan engine 100 may include a core turbine or gas turbine engine 104 disposed downstream of a fan section 106 .

[0026] The core turbine 104 generally includes a substantially tubular casing 108 that defines an annular inlet 110. The casing 108 may be formed by a single shell or multiple shells. The casing 108 surrounds a compressor section having a supercharger or low-pressure compressor 112 ("LP compressor 112") and a high-pressure compressor 114 ("HP compressor 114"), a combustion section 116, a turbine section having a high-pressure turbine 118 ("HP turbine 118") and a low-pressure turbine 120 ("LP turbine 120"), and an exhaust section 122 in a series flow relationship. A high-pressure shaft or spool 124 ("HP shaft 124") is drivingly coupled to the HP turbine 118 and the HP compressor 114. A low-pressure shaft or spool 126 ("LP shaft 126") is drivingly coupled to the LP turbine 120 and the LP compressor 112. The LP shaft 126 may also be coupled to a fan spool or shaft 128 of the fan section 106. In some examples, LP shaft 126 may be directly coupled to fan shaft 128 (ie, a direct drive configuration). In an alternative configuration, LP shaft 126 may be coupled to fan shaft 128 via reduction gear 130 (eg, an indirect drive or geared configuration).

[0027] like Figure 1 As shown, fan section 106 includes a plurality of fan blades 132 coupled to and extending radially outward from fan shaft 128. An annular fan casing or nacelle 134 circumferentially surrounds fan section 106 and / or at least a portion of core turbine 104. Nacelle 134 is supported relative to core turbine 104 by a plurality of circumferentially spaced outlet guide vanes 136. In addition, a downstream section 138 of nacelle 134 may surround an outer portion of core turbine 104 to define a bypass airflow passage 140 therebetween.

[0028] like Figure 1As shown, air 142 enters an inlet portion 144 of the turbofan engine 100 during operation of the turbofan engine 100. A first portion 146 of the air 142 flows into the bypass flow passage 140, while a second portion 148 of the air 142 flows into the inlet 110 of the LP compressor 112. One or more successive stages of LP compressor stator vanes 150 and LP compressor rotor blades 152 coupled to the LP shaft 126 progressively compress the second portion 148 of the air 142 flowing through the LP compressor 112 to be directed to the HP compressor 114. Next, one or more successive stages of HP compressor stator vanes 154 and HP compressor rotor blades 156 coupled to the HP shaft 124 further compress the second portion 148 of the air 142 flowing through the HP compressor 114. This provides the compressed air 158 to the combustion section 116, where it is mixed with fuel and combusted to provide combustion gases 160.

[0029] The combustion gases 160 flow through the HP turbine 118, where one or more successive stages of HP turbine stator blades 162 and HP turbine rotor blades 164 coupled to the HP shaft 124 extract a first portion of kinetic and / or thermal energy from the combustion gases 160. This energy extraction supports the operation of the HP compressor 114. The combustion gases 160 then flow through the LP turbine 120, where one or more successive stages of LP turbine stator blades 166 and LP turbine rotor blades 168 coupled to the LP shaft 126 extract a second portion of thermal and / or kinetic energy therefrom. This energy extraction causes the LP shaft 126 to rotate, thereby supporting the operation of the LP compressor 112 and / or the rotation of the fan shaft 128. The combustion gases 160 then exit the core turbine 104 through the exhaust section 122 of the core turbine 104.

[0030] As with the turbofan engine 100, the core turbine 104 is used for similar purposes and sees similar environments in land-based gas turbines, turbojets, and non-ducted fan engines, where the ratio of the first portion 146 of air 142 to the second portion 148 of air 142 is less than that of the turbofan engine, and where the fan section 106 does not have a nacelle 134. In each of the turbofan engine, turbojets, and non-ducted engines, a speed reduction device (e.g., a speed reduction gearbox 130) may be included between any shaft and the spool. For example, the speed reduction gearbox 130 may be disposed between the LP shaft 126 and the fan shaft 128 of the fan section 106.

[0031] Figure 2 Shows Figure 1 An example cross-sectional side view of an HP compressor 114 of a turbofan engine 100 is shown. The HP compressor 114 includes one or more consecutive stages. Figure 2 The illustrated example includes a first stage 206, a second stage 208 axially downstream of the first stage 206, a third stage 210 axially downstream of the second stage 208, and a fourth stage 212 axially downstream of the third stage 210. However, the HP compressor 114 may include more or fewer stages as needed or desired.

[0032] Each of the stages 206, 208, 210, 212 includes a row 214 of stator vanes 202 and a row 216 of rotor blades 204. The stator vanes 202 in row 214 are circumferentially spaced apart. In the examples disclosed herein, the stator vanes 202 are variable stator vanes ("VSV 202"), which may be coupled to one or more synchronizing rings or brackets, for example. The synchronizing rings or brackets are coupled to an actuator to rotate the VSV 202 at least partially about a radial axis. For example, the VSV 202 is coupled to a VSV lever arm 230. In the examples disclosed herein, the VSV 202 may rotate about an axis in a radial direction R to mitigate compressor stall or surge. Each VSV 202 includes a trunnion 227 to couple with a corresponding inner shroud 226. In Figure 2 In the example shown, the trunnion 227 is disposed radially inwardly from the engine case 232. Figure 2 In the example shown, inner shroud 226 is coupled to a sealed box 228 .

[0033] Similarly, rotor blades 204 in row 216 are also circumferentially spaced apart. Figure 2 In the example shown, the row 216 of rotor blades 204 is positioned axially downstream of the row 214 of stator vanes 202. Each rotor blade 204 includes a connection portion 234 (not labeled relative to the rotor blades 204 of stages 208, 210, 212) extending radially inward from the engine case 232 for coupling with a corresponding rotor disk 218. The connection portion may include an axial dovetail, a circumferential dovetail, a fir tree, or other connection portion shape.

[0034] The rows 214 of the stator blades 202 and the rows 216 of the rotor blades 204 of each of the stages 206, 208, 210, 212 collectively define a compressed gas path 222 through which the second portion 148 of the air 142 flows. In particular, the stator blades 202 direct the second portion 222 of the air 142 onto the rotor blades 204, which imparts kinetic energy to the second portion 148 of the air 142. In this regard, the rotor blades 204 convert the second portion 148 of the air 142 flowing through the HP compressor 114 into the compressed air 158. If the exit guide vanes are included, the exit guide vanes direct the compressed air flow 158 into the combustion section 116.

[0035] A coupling, such as a labyrinth seal 224, is located between each pair of adjacent rotor disks 218. For example, Figure 2 In the example shown, the first labyrinth seal 224 is located between the rotor disks 218 of the first and second stages 206, 208. The second labyrinth seal 224 is located between the rotor disks 218 of the second and third stages 208, 210. The third labyrinth seal 224 is located between the rotor disks 218 of the third and fourth stages 210, 212. The fourth labyrinth seal 224 is axially positioned downstream of the rotor disk 218 of the fourth stage 212. The labyrinth seal 224 prevents interstage leakage of the second portion 148 of the air 142 across the compressor stages 206, 208, 210, 212. In addition, the labyrinth seal 224 allows relative rotation between each row 214 of the stator vanes 202 and the adjacent rotor disk 218. This allows the rotor blades 204 to rotate while the stator vanes 202 remain stationary. In other examples, the coupling may be a brush seal (not shown) or any type of suitable seal. In this regard, when the HP turbine 118 drives the HP shaft 124 , all of the rotor disks 218 rotate in unison. Furthermore, each of the labyrinth seals 224 is coupled with each corresponding pair of adjacent rotor disks 218 , thereby defining a rotor disk space 220 .

[0036] Figure 3 An example cross-sectional view of an example first inner shroud damper 300 is illustrated. Figure 3 Examples of graphics include Figure 1 and Figure 2 1 is a perspective view of a cross-sectional side view of the HP compressor 114. The HP compressor 114 includes a VSV 202 of a row 214 of a second stage 208. However, rows 214 of stages 206, 210, 212 may additionally or alternatively be included. Figure 3 Only one VSV 202 is shown, but it should be understood that one or more VSVs 202 may be included. The HP compressor 114 includes an inner shroud 226 and a seal box 228 , including an inner shroud damper 300 .

[0037] The inner shroud damper 300 includes a first carrier 302, a second carrier 304, and a mass damper 306. In the examples disclosed herein, the first carrier 302 and the second carrier 304 act as carriers for the mass damper 306. For example, the carriers 302, 304 act as interfaces between the mass damper 306 and the inner shroud 226. The carriers 302, 304 may be arms, segments, etc. However, other configurations and / or methods may be used to couple the mass damper 306 to the inner shroud 226. The carriers 302, 304 are disposed within the inner shroud 226 and the sealed box 228. In some examples, the carriers 302, 304 are curved beam structures such that they circumferentially pass through the sealed housing (e.g., sealed box 228) of the inner shroud 226. However, the carriers 302, 304 may be other shapes that are combined with the inner shroud 226. The carriers 302, 304 may be cantilever bolted arms coupled to the inner shroud 226. The carrier, as shown by carriers 302, 304, can be any material suitable for the environment and compatible within the shield and damping system. In some examples, carriers 302, 304 are steel. However, carriers 302, 304 can additionally or alternatively be titanium, iron, nickel alloys, etc., with sufficient strength, fatigue, and / or other material properties for vibration reduction.

[0038] The mass damper 306 is disposed between the first carrier 302 and the second carrier 304. In the examples disclosed herein, the mass damper 306 is bolted, brazed and / or retained to the carriers 302, 304. For example, the mass damper 306 is integrally brazed or otherwise retained to the carriers 302, 304. In some examples, the mass damper 306 and the carriers 302, 304 are integrally brazed to the inner shroud 226. In some examples, the mass damper 306 is a honeycomb structure (e.g., an array of hollow cells formed between walls). In some examples, the mass damper 306 includes one or more layers of honeycomb structure. However, the mass damper 306 is additionally or alternatively an inertial mass, a viscoelastic material (e.g., rubber, silicone, etc.), etc.

[0039] In the examples disclosed herein, the mass damper 306 provides mass damping behavior during engine operation. For example, the mass damper 306 absorbs energy (e.g., vibration energy) during engine operation and acts as an anti-mode to certain vibration responses. That is, the VSV 202 vibrates at a first frequency during normal engine operation based on the design parameters of the VSV 202 (e.g., durability, stiffness, etc.). The mass damper 306 can be tuned (e.g., designed to have a certain durability, stiffness, weight, etc.) to vibrate at a second frequency during normal engine operation, so that the second frequency interferes with the first frequency. That is, the mass damper 306 can be tuned to act as an anti-mode to the vibration of the gas turbine engine 100. For example, the gas turbine engine 100 can vibrate at a first frequency of 10 Hz. The mass damper 306 can be tuned to vibrate at a second frequency that is an integral of the non-system response, such as 13 Hz or 14 Hz. The vibrations of the mass damper 306 interfere with the vibrations of the VSV 202 and thus dampen the vibrations of the VSV 202 .

[0040] Figure 4A Pictured Figure 3 2. An example perspective view of a first inner shroud damper 300 of FIG. The inner shroud damper 300 includes a first joint 402 and a second joint 404. For example, the first carrier 302 is coupled to the inner shroud 226 via the first joint 402, and the second carrier 304 is coupled to the inner shroud 226 via the second joint 404. However, other configurations and / or methods may be used to couple the inner shroud damper 300 to the inner shroud 226. In some examples, the joints 402, 404 may be used to form a device for coupling at least one carrier (e.g., the first carrier 302, the second carrier 304) to the inner shroud (e.g., the inner shroud 226). In some examples, the joints 402, 404 are bolts. However, the joints 402, 404 may be screws, pins, etc.

[0041] exist Figure 4A In the example shown, the inner shroud damper 300 includes three mass dampers 306. However, the inner shroud damper 300 may include more or fewer mass dampers 306. For example, the inner shroud damper 300 includes a first mass damper 406, a second mass damper 408, and a third mass damper 410. Figure 4AIn the example shown, the first carrier 302 has a first side 412 and a second side 414, and the second carrier 304 has a first side 416 and a second side 418. The mass dampers 406, 408, 410 are coupled to the second side 414 of the first carrier 302 and the first side 416 of the second carrier 304. In some examples, the number of mass dampers 306 corresponds to the number of VSVs 202 (e.g., a one-to-one ratio, a two-to-one ratio, etc.). The mass dampers 306 (e.g., the mass dampers 406, 408, 410) are circumferentially spaced apart. At least the mass dampers 306 (e.g., the first mass damper 406, the second mass damper 408, the third mass damper 410, etc.) may be used to implement a device for damping engine vibrations.

[0042] Figure 4B An example perspective view of the joint 404 is shown. For example, the second carrier 304 is disposed in the sealed box 228. The joint 404 of the second carrier 304 may couple the second carrier 304 to the inner shroud 226 (not shown).

[0043] Figure 5A An example cross-sectional view of a second example inner shroud damper 500 is illustrated. Figure 5A The illustrated example includes a portion of the VSV 202 and the labyrinth seal 224. The inner shroud damper 500 includes a carrier 502, a first mass damper 504, and a second mass damper 506. The carrier 502 is a curved beam structure such that the carrier 502 circumferentially passes through a sealed housing (e.g., a sealed box 228) of the inner shroud 226. However, the carrier 502 may be other shapes that are combined with the inner shroud 226. For example, the carrier 502 may be a cantilever bolted arm coupled to the inner shroud 226. Figure 5A In the example shown, carrier 502 is disposed between mass dampers 504, 506. The carrier, as shown by carriers 302, 304, can be any material suitable for the environment and compatible within the shield and damping system. For example, carrier 502 is steel. However, carrier 502 can additionally or alternatively be a titanium alloy, iron or nickel alloy having sufficient strength, fatigue and / or other material properties, etc., for vibration reduction.

[0044] Figure 5B Shows Figure 5A FIG. 5 is an example perspective view of a second example inner shroud damper 500 . Figure 5B The example shown includes a carrier 502, a first mass damper 504, a second mass damper 506, and a joint 508. However, other configurations and / or methods may be used to couple the inner shroud damper 500 to the inner shroud 226. The carrier 502 is coupled to the inner shroud 226 via the joint 508. In some examples, the joint 508 is a bolt. However, the joint 508 may be a screw, a pin, etc.

[0045] Figure 5B The illustrated example of includes a pair of mass dampers (e.g., a first mass damper 504 and a second mass damper 506 are aligned). However, the inner shroud damper 500 may include additional or fewer mass dampers (e.g., mass dampers 504, 506) and / or pairs of mass dampers. The carrier 502 has a first side 510 and a second side 512. The first mass damper 504 is bolted, brazed, and / or retained to the first side 510 of the carrier 502. The second mass damper 506 is bolted, brazed, and / or retained to the second side 512 of the carrier 502. For example, the mass dampers 504, 506 are integrally brazed or otherwise retained to the carrier 502. In some examples, the mass dampers 504, 506 and the carrier 502 are integrally brazed to the inner shroud 226. In some examples, the mass dampers 504, 506 are honeycomb structures (e.g., an array of hollow cells formed between walls). However, the mass dampers 504, 506 can be inertial masses, viscoelastic materials (e.g., rubber, silicone, etc.), etc. In the examples disclosed herein, the mass dampers 504, 506 provide mass damping behavior during engine operation. For example, the mass dampers 504, 506 absorb energy (e.g., vibration energy) during engine operation and act as anti-modes for certain vibration responses. That is, the VSV 202 vibrates at a first frequency during normal engine operation based on the design parameters of the VSV 202 (e.g., durability, stiffness, etc.). The mass dampers 504, 506 can be tuned (e.g., designed to have a certain durability, stiffness, weight, etc.) to vibrate at a second frequency during normal engine operation so that the second frequency interferes with the first frequency.

[0046] In the examples disclosed herein, the second inner shroud damper 500 may include one or more pairs of mass dampers. In some examples, the number of mass damper pairs corresponds to the number of VSVs 202 (e.g., a one-to-one ratio, a two-to-one ratio, etc.). The mass damper pairs are circumferentially spaced apart. Figure 5B In the example shown, the pair of mass dampers 504, 506 are aligned relative to each other. In some examples, the first mass damper 504 and the second mass damper 506 are not paired (eg, the second mass damper 506 is offset relative to the first mass damper 504).

[0047] The inner shroud damper 300 and / or the inner shroud damper 500 may prevent and / or reduce strain caused by engine vibrations of the VSV 202 during normal engine operation. The reduction / prevention of engine vibrations increases the reliability of the VSV 202 and the durability of the VSV 202. For example, the improved reliability / durability of the VSV 202 may reduce the risk of stalling due to blade locking. Additionally or alternatively, the inner shroud damper 300 and / or the inner shroud damper 500 reduces the weight, cost, etc. of the gas turbine engine 100.

[0048] In operation, the inner shroud damper (e.g., inner shroud damper 300 and / or inner shroud damper 500) coupled to the inner shroud 226 within the seal box 228 provides damping to act in an anti-mode manner to vibrations generated by the gas turbine engine 100. That is, the examples disclosed herein improve the reliability / durability of the gas turbine engine by reducing vibrations of the gas turbine engine (e.g., vibrations of one or more airfoils, etc.). In some examples, the inner shroud damper prevents engine vibrations, which reduces deformation and / or strain caused by gas turbine operation.

[0049] Although certain example methods, apparatus, and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture that fully fall within the scope of the claims of this patent.

[0050] Example methods, apparatus, systems, and articles of manufacture for reducing vibration are disclosed herein.

[0051] Further aspects of the invention are provided by the subject matter of the following clauses. Example 1 includes an inner shroud damper for a gas turbine engine, the inner shroud damper comprising: at least one carrier including a joint coupled to an inner shroud, the at least one carrier having a first side and a second side; and at least one mass damper coupled to the at least one carrier.

[0052] Example 2 includes the inner shroud damper of any preceding clause, wherein the at least one carrier is a curved beam structure.

[0053] Example 3 includes the inner shroud damper of any preceding clause, wherein the at least one carrier is disposed within a sealed box coupled to the inner shroud.

[0054] Example 4 includes the inner shroud damper of any preceding clause, wherein the joint is a bolt.

[0055] Example 5 includes the inner shroud damper of any preceding clause, wherein the at least one mass damper is tuned to act anti-mode to engine vibrations based on at least one of durability, stiffness, or weight.

[0056] Example 6 includes the inner shroud damper of any preceding clause, wherein the at least one mass damper is a honeycomb structure.

[0057] Example 7 includes the inner shroud damper of any preceding clause, wherein the at least one carrier is a first carrier and the joint is a first joint, further comprising a second carrier including a second joint coupled to the inner shroud, the second carrier having a first side and a second side.

[0058] Example 8 includes the inner shroud damper of any preceding clause, wherein the at least one mass damper is coupled to the second side of the first carrier and the first side of the second carrier.

[0059] Example 9 includes an inner shroud damper according to any preceding clause, wherein the at least one mass damper is a first mass damper, further comprising a second mass damper, the second mass damper being coupled to the second side of the first carrier and the first side of the second carrier, the second mass damper being circumferentially spaced apart from the first mass damper.

[0060] Example 10 includes the inner shroud damper of any preceding clause, wherein the at least one mass damper is a first mass damper coupled to the first side of the at least one carrier, further comprising a second mass damper coupled to the second side of the at least one carrier.

[0061] Example 11 includes the inner shroud damper of any preceding clause, wherein the first mass damper and the second mass damper are aligned.

[0062] Example 12 includes the inner shroud damper of any preceding clause, wherein the first mass damper is offset from the second mass damper.

[0063] Example 13 includes a gas turbine engine comprising: an inner shroud; a seal box coupled to the inner shroud; and an inner shroud damper comprising at least one carrier disposed inside the seal box and at least one mass damper coupled to the at least one carrier, the at least one carrier comprising a joint coupled to the inner shroud.

[0064] Example 14 includes the gas turbine engine of any preceding clause, wherein the at least one carrier is a curved beam structure.

[0065] Example 15 includes the gas turbine engine of any preceding clause, the at least one mass damper being tuned to act anti-mode to engine vibrations based on at least one of durability, stiffness, or weight.

[0066] Example 16 includes the gas turbine engine of any preceding clause, wherein the at least one mass damper is a honeycomb structure.

[0067] Example 17 includes a gas turbine engine according to any preceding clause, wherein the at least one carrier is a first carrier frame and the joint is a first joint, further comprising a second carrier, the second carrier comprising a second joint coupled to the inner shroud, the second carrier having a first side and a second side.

[0068] Example 18 includes the gas turbine engine of any preceding clause, wherein the at least one mass damper is coupled to the second side of the first carrier and the first side of the second carrier.

[0069] Example 19 includes the gas turbine engine of any preceding clause, wherein the at least one mass damper is a first mass damper coupled to a first side of the at least one carrier, further comprising a second mass damper coupled to a second side of the at least one carrier.

[0070] Example 20 includes an inner shroud damper for a gas turbine engine, the inner shroud damper comprising: means for coupling at least one carrier to the inner shroud; and means for damping engine vibrations, the means for damping coupled to the at least one carrier.

[0071] The following claims are hereby incorporated into the Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.

Claims

1. An inner shroud damper of a gas turbine engine, wherein the gas turbine engine defines an axial direction and a radial direction, characterized in that: The inner shroud damper comprises: At least one carrier, the at least one carrier comprising: a curved structure having a first side and a second side along the axial direction; a joint extending from the curved structure in the radial direction, the joint being configured to be coupled to an inner shroud of the gas turbine engine; and At least one mass damper is directly coupled to the first side or the second side of the curved structure of the at least one carrier.

2. The inner shroud damper according to claim 1, characterized in that: The at least one carrier is disposed within a sealed box coupled to the inner shroud.

3. The inner shroud damper according to claim 1, characterized in that: The joints are bolts.

4. The inner shroud damper according to claim 1, characterized in that: Wherein the at least one mass damper is tuned to act anti-mode to engine vibrations based on at least one of durability, stiffness, or weight.

5. The inner shroud damper according to claim 1, characterized in that: Wherein the at least one mass damper is a honeycomb structure.

6. The inner shroud damper according to claim 1, characterized in that: Wherein the at least one carrier is a first carrier and the joint is a first joint, further comprising a second carrier comprising a second joint coupled to the inner shroud, the curved structure of the second carrier having a first side and a second side.

7. The inner shroud damper according to claim 6, characterized in that: Wherein the at least one mass damper is coupled to the second side of the curved structure of the first carrier and to the first side of the curved structure of the second carrier.

8. The inner shroud damper according to claim 6, characterized in that: Wherein the at least one mass damper is a first mass damper, further comprising a second mass damper coupled to the second side of the curved structure of the first carrier and the first side of the curved structure of the second carrier, the second mass damper being circumferentially spaced apart from the first mass damper.

9. The inner shroud damper according to claim 1, characterized in that: Wherein the at least one mass damper is a first mass damper coupled to the first side of the curved structure of the at least one carrier, further comprising a second mass damper coupled to the second side of the curved structure of the at least one carrier.

10. The inner shroud damper according to claim 9, characterized in that: Wherein the first mass damper and the second mass damper are aligned.

11. The inner shroud damper according to claim 9, characterized in that: Wherein the first mass damper is offset from the second mass damper.

12. A gas turbine engine, the gas turbine engine defining an axial direction and a radial direction, characterized in that: include: Inner shroud; a sealing box coupled to the inner shroud; and An inner shroud damper, the inner shroud damper comprising at least one carrier disposed inside the sealed box, the at least one carrier comprising: a curved structure having a first side and a second side along the axial direction; a joint extending from the curved structure in the radial direction, the joint being configured to be coupled to the inner shroud; and At least one mass damper is directly coupled to the first side or the second side of the curved structure of the at least one carrier.

13. The gas turbine engine according to claim 12, characterized in that Wherein the at least one mass damper is tuned to act anti-mode to engine vibrations based on at least one of durability, stiffness, or weight.

14. The gas turbine engine according to claim 12, characterized in that Wherein the at least one mass damper is a honeycomb structure.

15. The gas turbine engine according to claim 12, characterized in that Wherein the at least one carrier is a first carrier and the joint is a first joint, further comprising a second carrier comprising a second joint coupled to the inner shroud, the curved structure of the second carrier having a first side and a second side.

16. The gas turbine engine according to claim 15, characterized in that Wherein the at least one mass damper is coupled to the second side of the curved structure of the first carrier and to the first side of the curved structure of the second carrier.

17. The gas turbine engine according to claim 12, characterized in that Wherein the at least one mass damper is a first mass damper coupled to a first side of the curved structure of the at least one carrier, further comprising a second mass damper coupled to a second side of the curved structure of the at least one carrier.

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