Torsional vibration damper mechanism for gas turbine engine

Abstract

A torsional vibration damper mechanism for damping torsional vibration of a first drive shaft, a second drive shaft, or both. The torsional vibration damper mechanism includes a third drive shaft mechanically coupled to the first drive shaft, the second drive shaft, or both. The third drive shaft is configured to reduce or substantially eliminate torsional vibrations in the first drive shaft, the second drive shaft, or both.

Description

Technical Field

[0001] The present disclosure generally relates to drive shafts in gas turbine engines and, more particularly, to torsional vibration damper mechanisms for gas turbine engines. Background Art

[0002] An engine, particularly a gas or combustion turbine engine, is a rotary engine that extracts energy from a flow of combustion gases passing through the engine onto a plurality of turbine blades. Turbine engines have been used in land and marine locomotion as well as in power generation. Turbine engines are commonly used in aviation applications, such as for aircraft, including helicopters and airplanes. In an aircraft, a turbine engine is used for propulsion. In land applications, turbine engines are often used for power generation.

[0003] Complex machines, such as turbine engines, include rotating systems to convert energy into work, or use, for example, gears to rotate drive shafts and, in some cases, gearboxes to transfer rotation from one component to another. Vibration of components or parts, including drive shafts, during operation adds stress to the components or parts, which can lead to potential failures. Brief Description of the Drawings

[0004] The above and other features and advantages will be apparent from the following more particular description of various exemplary embodiments, as illustrated in the accompanying drawings, in which like reference numerals generally represent the same, functionally similar, and / or structurally similar elements.

[0005] Figure 1 is a schematic view of a turbine engine according to an embodiment of the present disclosure.

[0006] Figure 2 is a schematic view of a turbine engine according to an embodiment of the present disclosure, showing the connection between the fan assembly, the LPC assembly, and the LPT assembly via a first drive shaft, and the connection between the HPC assembly and the HPT assembly via a second drive shaft.

[0007] Figure 3A is a schematic view showing a torsional vibration coupling between the fan assembly and the LPC assembly and the LPT assembly via a first drive shaft according to an embodiment of the present disclosure.

[0008] Figure 3B is a schematic view showing a torsional vibration coupling between the fan assembly and the LPT assembly and the LPC assembly via a first drive shaft according to another embodiment of the present disclosure.

[0009] Figure 4 is a schematic view of a torsional vibration damper mechanism according to an embodiment of the present disclosure, the torsional vibration damper mechanism being coupled to the first drive shaft to reduce torsional vibration in the first drive shaft.

[0010] Figure 5 is a schematic cross-sectional view of a first drive shaft employing a torsional vibration damper mechanism according to another embodiment of the present disclosure.

[0011] Figure 6A and Figure 6B each show a graph of the relationship between the torsional vibration θ and the lengths of the first drive shaft and the third drive shaft of the torsional vibration damper mechanism according to an embodiment of the present disclosure.

[0012] Figure 7 is a schematic cross-sectional view of a first drive shaft employing another torsional vibration damper mechanism according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] Additional features, advantages, and embodiments of the present disclosure are set forth or apparent by considering the following detailed description, the drawings, and the claims. Further, the following detailed description is exemplary and is intended to provide further explanation without limiting the scope of the claimed present disclosure.

[0014] Various embodiments of the present disclosure are discussed in detail below. While specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the present disclosure.

[0015] In the following specification and claims, the terms "optional" or "optionally" may be used to indicate that a subsequent described event or circumstance may or may not occur, and the description includes instances where the event occurs and instances where the event does not occur.

[0016] As used herein, the terms "axial" and "axially" refer to a direction and orientation that extends substantially parallel to the centerline of a turbine engine or a burner. Further, the terms "radial" and "radially" refer to a direction and orientation that extends substantially perpendicular to the centerline of a turbine engine. A turbine engine includes, for example, a turbojet engine, a turboprop engine, a turbofan engine, or a turboshaft engine.

[0017] Embodiments of the present disclosure are directed to systems and methods for suppressing torsional vibrations of a shaft. A shaft (such as an elongated shaft) may have a relatively high inertia, which may cause torsional vibrations in the shaft. For example, the connection of a low-pressure (LP) and / or booster compressor (LPC) assembly coupled to a front fan assembly and an LP drive shaft may cause torsional vibrations in the LP drive shaft. Additionally, the presence of a gearbox between the LPC assembly and the LP drive shaft can further excite the torsional vibration response in the LP drive shaft. Therefore, to reduce or substantially eliminate torsional vibrations, a torsional vibration damper mechanism is used. For example, the torsional vibration damper mechanism may be integrated with a rotating shaft anywhere that can maximize the effectiveness of the damper.

[0018] In some embodiments, the torsional vibration mechanism includes aligning two different vibration modes of a main shaft and an integrated shaft with a flexible attachment to limit the response by aligning a node with an antinode. The mechanism can be placed anywhere where damper effectiveness is desired and space is available.

[0019] In some embodiments, the torsional vibration damper mechanism may include viscoelastic materials or smart materials such as shape memory alloy (SMA). Alternatively or additionally, trapped highly viscous fluids can be used to damp torsional vibrations.

[0020] In some embodiments, a combination of a rigid member and a flexible member can be provided with vibration damping inserts. For example, the vibration damping insert can include an inverted Y-shaped beam insert that couples an inertial inner ring to one or more outer rings. The inverted Y-shaped beam insert can be tuned for a torsional mode of interest. The insert can also include viscoelastic materials.

[0021] Any torque fluctuations will cause displacement of the flexible member or shaft relative to the damping element. Benefits of using the torsional vibration mechanism include, but are not limited to, providing controlled torsional vibrations for slender architectures. Otherwise, rotor components released from high torque pulsations may cause high cycle fatigue (HCF).

[0022] Figure 1 is a schematic view of a turbine engine 10 according to an embodiment of the present disclosure. The turbine engine 10 includes a fan assembly 12, a low-pressure and / or booster compressor (LPC) assembly 14, a high-pressure compressor (HPC) assembly 16, and a combustor assembly 18. The fan assembly 12, the LPC assembly 14, the HPC assembly 16, and the combustor assembly 18 are coupled in fluid communication. The turbine engine 10 further includes a high-pressure turbine (HPT) assembly 20 that is coupled in fluid communication with the combustor assembly 18 and a low-pressure turbine (LPT) assembly 22. The fan assembly 12 includes an array of fan blades 24 that extend radially outward from a rotor disk 26. The LPT assembly 22 is coupled to the fan assembly 12 and the LPC assembly 14 by a first drive shaft 28 (LP shaft), and the HPT assembly 20 is coupled to the HPC assembly 16 by a second drive shaft 30 (HP shaft). The turbine engine 10 has an air inlet 32 and an exhaust outlet 34. The turbine engine 10 has a centerline (axis) 36 about which the fan assembly 12, the LPC assembly 14, the HPC assembly 16, the HPT assembly 20, and the LPT assembly 22 rotate.

[0023] In operation, air entering the turbine engine 10 through the air inlet 32 is directed through the fan assembly 12 toward the LPC assembly 14. Compressed air is discharged from the LPC assembly 14 toward the HPC assembly 16. Highly compressed air is directed from the HPC assembly 16 toward the combustor assembly 18, where it is mixed with fuel, and the air and fuel mixture is burned within the combustor assembly 18. The hot combustion gases generated by the combustor assembly 18 are directed toward the HPT assembly 20 and the LPT assembly 22. The combustion gases are then exhausted from the turbine engine 10 via the exhaust outlet 34.

[0024] Figure 2 is a schematic view of a turbine engine 10 according to an embodiment of the present disclosure, showing the connection between the fan assembly 12, the LPC assembly 14, and the LPT assembly 22 via the first drive shaft 28, and the connection between the HPC assembly 16 and the HPT assembly 20 via the second drive shaft 30. As Figure 2 shown, the turbine engine 10 further includes a plurality of stator assemblies 42, 44, and 46. The stator assembly 42 is disposed between the LPC assembly 14 and the HPC assembly 16. The stator assembly 44 is disposed between the HPT assembly 20 and the LPT assembly 22. The stator assembly 46 is disposed at the rear end of the LPT assembly 22. The combustor assembly 18 is disposed between the HPC assembly 16 and the HPT assembly 20. The turbine engine 10 further includes a plurality of bearings 51, 52, 53, 54, and 55. The plurality of bearings 51, 52, 53, 54, and 55 are disposed at different points to connect the LPC assembly 14, the HPC assembly 16, the HPT assembly 20, and the LPT assembly 22 to the stator assembly 42, the stator assembly 44, and the stator assembly 46, respectively. In an embodiment, a gearbox 60 may be disposed between the LPC assembly 14 and the first drive shaft 28. For example, the gearbox 60 may be disposed between the bearing 51 and the bearing 52 connected to the stator assembly 42. The gearbox 60 may be used to change the rotational speed transmitted from the LPC assembly 14 and the first drive shaft 28.

[0025] In an embodiment, the first drive shaft 28 (LP shaft) may have a relatively high inertia relative to other rotating components, which may cause torsional vibrations in the first drive shaft 28. For example, when the first drive shaft 28 (LP shaft) is connected to the fan assembly 12, the first drive shaft 28 (LP shaft) may have a relatively high inertia towards the end of the shaft, and the fan assembly 12 has a relatively larger mass and / or a larger radius compared to the mass and / or radius of other rotating components (e.g., other fan blades in the LPT). Generally, since the moment of inertia of an object is proportional to the mass of the object and the radius of the object, a larger mass and / or radius will result in a higher moment of inertia. For example, the connection of the LPC assembly 14 coupled to the front fan assembly 12 via the first drive shaft 28 may cause torsional vibrations in the first drive shaft 28. Additionally, the gearbox 60 disposed between the LPC assembly 14 and the first drive shaft 28 may further excite the torsional vibration response in the first drive shaft 28. The unwanted torsional vibrations in the first drive shaft 28 should be eliminated because over time, the vibrations will introduce stress on the first drive shaft 28 itself and other components or assemblies coupled to the first drive shaft 28. Therefore, in order to reduce or substantially eliminate the torsional vibrations, a torsional vibration damper mechanism 70 is used. The torsional mechanism 70 will be described in detail in the following paragraphs. In an embodiment, as Figure 2 shown, the torsional vibration damper mechanism 70 may be disposed between the fan assembly 12 and the LPC assembly 14 and the LPT assembly 22 via the first drive shaft 28. For example, the torsional vibration damper mechanism 70 may be integrated with the rotating shaft anywhere where the damper effectiveness can be enhanced or maximized. The term "substantially eliminate" as used herein means to eliminate at least 95% of the unwanted torsional vibrations.

[0026] Figure 3A FIG. is a schematic diagram showing the vibrational torsional coupling between the fan assembly 12 together with the LPC assembly 14 and the LPT assembly 22 via the first drive shaft 28 according to an embodiment of the present disclosure. In Figure 3A , the fan assembly 12 ( Figure 2 shown in Figure 2 ) together with the LPC assembly 14 ( Figure 2 shown in Figure 2 ) is schematically represented by the box 13. The first drive shaft 28 couples the box 13 schematically representing the fan assembly 12 together with the LPC assembly 14 to the LPT assembly 22. In this configuration, the first drive shaft 28 may have a certain stiffness schematically depicted by the spring 27, and the spring 27 has a constant K representing the vibrational torsional coupling of the first drive shaft 28. Figure 3A is schematically depicted Figure 2 the configuration shown in

[0027] Figure 3B FIG. is a schematic diagram showing another embodiment of the present disclosure of the fan assembly 12 and the LPT assembly 22 ( Figure 2shown together with the LPC component 14( Figure 2 schematic illustration of a vibration torsional coupling via a first drive shaft 28 between the one shown in Figure 3B In, the LPT component 22 together with the LPC component 14 is schematically represented by a box 23. The first drive shaft 28 couples the fan component 12 to the box 23 that schematically represents the LPT component 22 together with the LPC component 14. In this structure, the first drive shaft 28 can have another stiffness schematically depicted via a spring 29, and the spring 29 has a constant K’ representing the vibration torsional coupling of the first drive shaft 28.

[0028] Although the vibration torsional coupling is described in the above paragraph as being in the first drive shaft 28 (LP shaft), a torsional vibration coupling can equally exist in the second drive shaft 30 (HP shaft). Accordingly, a torsional vibration damper mechanism 70 can also be used in the second drive shaft 30 (HP shaft). For example, a first torsional vibration damper mechanism can be used in the first drive shaft 28, and a second torsional vibration damper mechanism separate from the first torsional vibration damper mechanism can be used in the second drive shaft 30. The torsional vibration damper mechanism 70 can be used as the first torsional vibration damper mechanism or the second torsional vibration damper mechanism.

[0029] In the following paragraphs, the torsional vibration damper mechanism 70 is described as being used in the first drive shaft 28. However, alternatively or additionally, the torsional vibration damper mechanism 70 can also be used in the second drive shaft 30.

[0030] Figure 4 is a schematic illustration of a torsional vibration damper mechanism 70 according to an embodiment of the present disclosure, and the torsional vibration damper mechanism 70 is coupled to the first drive shaft 28 to reduce torsional vibration in the first drive shaft 28. In this embodiment, the torsional vibration damper mechanism 70 can be, for example, a mass body coupled to the first drive shaft 28. For example, this mass body can be heavier or have a larger size (e.g., a larger radius, etc.) to increase the moment of inertia, thereby reducing the tendency of torsional vibration of the first drive shaft 28. For example, as Figure 4 shown, this mass body can be a third drive shaft 71 that is mechanically coupled to the first drive shaft 28 using mechanical coupling members 72A and 72B. As Figure 4 shown, the third drive shaft 71 is coupled to the first drive shaft 28 at spaced-apart positions. The third drive shaft 71 is coupled to the first drive shaft 28 at a first position using the mechanical coupling member 72A to provide a first coupling spring constant K1, and is coupled to the first drive shaft 28 at a second position spaced apart from the first position using the mechanical coupling member 72B to provide a second coupling spring constant K2. For example, the third drive shaft 71 can have a larger radius and / or a larger mass than the radius and / or mass of the first drive shaft 28.

[0031] As Figure 4 shown, the mechanical coupling 72A has a first coupling spring constant K1 (at the first position), and the mechanical coupling 72B has a second coupling spring constant K2 (at the second position). In an embodiment, the second coupling spring constant K1 can be greater than the first coupling spring constant K1 (K2 > K1). Thus, the coupling between the third drive shaft 71 and the first drive shaft 28 at the second position is stiffer (or more rigid) than the coupling between the third drive shaft 71 and the first drive shaft 28 at the first position. In an embodiment, the coupling between the first drive shaft 28 and the third drive shaft 71 at the first position (i.e., the first coupling spring constant K1) can be tuned to reduce or substantially eliminate torsional vibrations in the first drive shaft 28. In an embodiment, the tuned spring stiffness K1, the first position (i.e., the coupling axial position), and the secondary shaft geometry can be selected to achieve a desired vibration mode of the third drive shaft, thereby reducing or substantially eliminating vibrations in the first drive shaft 28. Thus, instead of providing a third drive shaft 71 having a mass and / or a higher radius greater than the mass or radius of the first drive shaft 28, or in addition to providing a third drive shaft 71 having a mass and / or a higher radius greater than the mass or radius of the first drive shaft 28, the coupling stiffness between the third drive shaft 71 and the first drive shaft 28, or the coupling position (the first position) can be selected to reduce or substantially eliminate torsional vibrations in the first drive shaft 28.

[0032] Figure 5 is a schematic cross-sectional view of the first drive shaft 28 employing a torsional vibration damper mechanism 80 according to another embodiment of the present disclosure. As Figure 5 shown, the torsional vibration damper mechanism 80 is coupled to the first drive shaft 28. In this embodiment, the torsional vibration damper mechanism 80 includes a third drive shaft 81. In an embodiment, the third drive shaft 81 of the torsional vibration damper mechanism 80 is a hollow drive shaft disposed within the first drive shaft 28. The third drive shaft 81 can have a hollow cavity 81A. The first drive shaft 28 is a hollow drive shaft. The first drive shaft 28 has a hollow cavity 84. The third drive shaft 81 is an inner shaft disposed within the cavity 84 of the first drive shaft 28. In an embodiment, the dimensions (e.g., radius, length) of the third drive shaft 81 are smaller than the dimensions (e.g., radius, length) of the first drive shaft 28. In an embodiment, the mass of the third drive shaft 81 is greater than the mass of the first drive shaft 28 and / or the second drive shaft 30.

[0033] In some embodiments, the vibration mode shapes of the first drive shaft 28 and / or the second drive shaft 30 can be aligned with the vibration mode shape of the torsional vibration damper mechanism 80 to reduce torsional vibrations in the first drive shaft 28. A flexible attachment can be used to couple the torsional vibration damper mechanism 80 to the first drive shaft 28 by aligning a node of the first drive shaft 28 with an antinode of the torsional vibration damper mechanism 80 to limit the vibration response, thereby limiting the response. The torsional vibration damper mechanism 80 can be placed anywhere where damper effectiveness is desired and space is available.

[0034] In some embodiments, in addition to the third drive shaft 81, the torsional vibration damper mechanism 80 further includes a plurality of vibration damping inserts 82 disposed in a cavity 84 between the third drive shaft 81 and the first drive shaft 28. The plurality of vibration damping inserts 82 can include a combination of rigid members and flexible members. For example, the plurality of vibration damping inserts 82 can include a plurality of inverted Y-shaped beam inserts 82A to couple the third drive shaft 81 of the torsional vibration damper mechanism 80 to the first drive shaft 28. The plurality of inverted Y-shaped beam inserts 82A can be tuned for torsional vibration modes of interest in the first drive shaft 28. The plurality of vibration damping inserts 82 can further include a plurality of damping elements 82B. The plurality of damping elements 82B are configured to couple the plurality of inverted Y-shaped beam inserts 82A to the third drive shaft 81 of the torsional vibration damper mechanism 80. The plurality of vibration damping inserts 82 can also include a plurality of coupling elements 82C. The plurality of coupling elements 82C are configured to couple the plurality of inverted Y-shaped beam inserts 82A to the first drive shaft 28. In an embodiment, the plurality of damping elements 82B can include a viscoelastic material, such as a shape memory alloy (SMA). In another embodiment, the plurality of damping elements 82B can include springs and / or viscous fluids to provide spring compression and / or fluid friction damping. Alternatively or additionally, a trapped viscous fluid can also be provided in the cavity 84 between the third drive shaft 81 of the torsional vibration damper mechanism 80 and the first drive shaft 28 to further suppress torsional vibrations.

[0035] Figure 6A and Figure 6B each show a graph of the torsional vibration θ versus the length of the first drive shaft 28 and / or the second drive shaft 30 ( Figure 2 shown in) and the length of the third drive shafts 71, 81 of the torsional vibration damper mechanisms 70 ( Figure 4 shown in), 80 ( Figure 5 shown in) according to embodiments of the present disclosure. As Figure 6A and Figure 6BAs shown, the first drive shaft 28 has a first oscillation mode, in which the torsional amplitude θ increases as the length of the first drive shaft 28 increases. The third drive shafts 71, 81 have a second oscillation mode, in which the torsional amplitude θ increases negatively as the length of the first drive shaft 28 increases, then increases positively and crosses the first node (zero amplitude), and then decreases again to the second node (zero amplitude). The third drive shafts 71, 81 having the second oscillation mode are coupled to the first drive shaft 28 having the first oscillation mode to limit the angular torsion or twist in the first drive shaft 28. The second oscillation mode of the third drive shafts 71, 81 limits or reduces the first oscillation mode of the first drive shaft 28.

[0036] The coupling of the third drive shafts 71, 81 to the first drive shaft 28 can be a direct coupling, or a coupling through the mechanical coupling 72A or a plurality of vibration damping inserts 82. As Figure 6A shown, the coupling of the third drive shafts 71, 81 to the first drive shaft 28 can be achieved at a first position (length). As Figure 6B shown, the coupling of the third drive shafts 71, 81 to the first drive shaft 28 can be achieved at a second position (length) different from the first length. Therefore, the torsional vibration damping can be adjusted by adjusting the position (or length) of the third drive shafts 71, 81 of the torsional vibration damper mechanisms 70, 80 relative to the first drive shaft 28.

[0037] The torsional vibration mechanisms 70, 80 described in the above paragraphs are used to suppress or reduce or substantially eliminate the torsional vibration in the first drive shaft 28. However, alternatively or additionally, the torsional vibration mechanisms 70, 80 can also be used to suppress or reduce or substantially eliminate the torsional vibration in the second drive shaft 30. Therefore, the above description of the torsional vibration mechanisms 70, 80 for the first drive shaft 28 also applies to the second drive shaft 30.

[0038] Figure 7 is a schematic cross-sectional view of the first drive shaft 28 employing the torsional vibration damper mechanism 90 according to another embodiment of the present disclosure. As Figure 7 shown, the torsional vibration damper mechanism 90 is coupled to the first drive shaft 28. In this embodiment, the torsional vibration damper mechanism 90 includes an inner disk 92 and a plurality of torque transmission struts 94, and the plurality of torque transmission struts 94 are configured to couple the first drive shaft 28 to the third drive shaft 81 (not shown in Figure 7 but shown in Figure 5 ). As Figure 7As shown, four torque transfer struts 94 are provided. However, any number of torque transfer struts 94 (e.g., two or more torque transfer struts) can be used. The inner disk 92 and the plurality of torque transfer struts 94 are disposed within the first drive shaft 28. The first drive shaft 28 is a hollow drive shaft. The first drive shaft 28 has a hollow cavity 96. The torsional vibration damper mechanism 90 is disposed within the hollow cavity 96 of the first drive shaft 28.

[0039] In an embodiment, the inner disk 92 of the torsional vibration damper mechanism 90 has a hollow cavity 91A and a plurality of slots 91B for coupling the torsional vibration damper mechanism 90 to the third drive shaft 81 ( Figure 7 not shown). The plurality of torque transfer struts 94 are coupled to the inner disk 92 at a first end 94A and are coupled to the first drive shaft 28 at a second end 94B using a plurality of coupling elements 98 (e.g., bolts).

[0040] In some embodiments, the vibration mode of the first drive shaft 28 can be aligned with the vibration mode of the torsional vibration damper mechanism 90 together with the third drive shaft 81 ( Figure 7 not shown) to reduce torsional vibration in the first drive shaft 28. A flexible attachment can be used to further couple the torsional vibration damper mechanism 90 to the first drive shaft 28 by aligning the node of the first drive shaft 28 with the antinode of the torsional vibration damper mechanism 90 to limit the vibration response, thereby further limiting the response. The torsional vibration damper mechanism 90 can be placed anywhere where damper effectiveness is desired and space is available.

[0041] In some embodiments, in addition to the inner disk 92 and the plurality of torque transfer struts 94, the torsional vibration damper mechanism 90 further includes a plurality of vibration damping inserts 100 disposed within the hollow cavity 96 between the inner disk 92 and the first drive shaft 28. As Figure 7 shown, four vibration damping inserts 100 are provided. However, any number of vibration damping inserts 100 (e.g., two or more vibration damping inserts) can be used.

[0042] A plurality of vibration damping inserts 100 may include a combination of rigid members and flexible members. For example, the plurality of vibration damping inserts 100 may include a plurality of inverted Y-shaped beam inserts 100A to couple the inner disk 92 of the torsional vibration damper mechanism 90 to the first drive shaft 28. The plurality of inverted Y-shaped beam inserts 100A may be tuned for torsional vibration modes of interest in the first drive shaft 28. The plurality of vibration damping inserts 100 may further include a plurality of damping elements 100B. The plurality of damping elements 100B are configured to couple the plurality of inverted Y-shaped beam inserts 100A to the inner disk 92 of the torsional vibration damper mechanism 90. The plurality of damping elements 100B may be disposed in slots 91C within the inner disk 92. The slots 91C may be disposed near a first end 94A of the plurality of torque transfer struts 94. The plurality of vibration damping inserts 100 may also include a plurality of coupling elements 100C. The plurality of coupling elements 100C are configured to couple the plurality of inverted Y-shaped beam inserts 100A to the first drive shaft 28. In an embodiment, the plurality of damping elements 100B may include a viscoelastic material such as a shape memory alloy (SMA). In another embodiment, the plurality of damping elements 100B may include springs and / or viscous fluids to provide spring compression and / or fluid friction damping.

[0043] A further aspect is provided by the subject matter of the following clauses.

[0044] Aspects of the present disclosure provide a torsional vibration mechanism for suppressing torsional vibrations of a first drive shaft, a second drive shaft, or both. The torsional vibration damper mechanism includes a third drive shaft mechanically coupled to the first drive shaft, the second drive shaft, or both. The third drive shaft is configured to reduce or substantially eliminate torsional vibrations in the first drive shaft, the second drive shaft, or both.

[0045] The torsional vibration damper mechanism according to the above clause, wherein the third drive shaft is directly coupled to the first drive shaft, the second drive shaft, or both.

[0046] The torsional vibration damper mechanism according to any one of the above clauses, wherein a radius of the third drive shaft is less than a radius of the first drive shaft, the second drive shaft, or both.

[0047] The torsional vibration damper mechanism according to any one of the above clauses, wherein a mass of the third drive shaft is greater than a mass of the first drive shaft, the second drive shaft, or both.

[0048] The torsional vibration damper mechanism according to any one of the above clauses, further comprising a mechanical coupling configured to mechanically couple the third drive shaft to the first drive shaft, the second drive shaft, or both.

[0049] The torsional vibration damper mechanism according to any one of the above items, wherein the third drive shaft is a hollow drive shaft disposed within the cavity of the first drive shaft, the second drive shaft, or both.

[0050] The torsional vibration damper mechanism according to any one of the above items, further comprising a plurality of vibration damping inserts disposed in the cavity between the third drive shaft and the first drive shaft, the second drive shaft, or both, the plurality of vibration damping inserts being configured to mechanically couple the third drive shaft to the first drive shaft, the second drive shaft, or both.

[0051] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of vibration damping inserts includes a plurality of inverted Y-shaped beam inserts configured to couple the third drive shaft to the first drive shaft, the second drive shaft, or both, wherein the plurality of inverted Y-shaped beam inserts are tunable for a torsional vibration mode of interest in the first drive shaft, the second drive shaft, or both.

[0052] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of vibration damping inserts includes a plurality of damping elements configured to couple the plurality of inverted Y-shaped beam inserts to the third drive shaft.

[0053] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of damping elements includes a viscoelastic material, a shape memory alloy (SMA), a spring, or a viscous fluid, or any combination thereof, to provide spring compression or fluid friction damping.

[0054] The torsional vibration damper mechanism according to any one of the above items, further comprising a trapped viscous fluid disposed in the cavity between the third drive shaft and the first drive shaft, the second drive shaft, or both.

[0055] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of vibration damping inserts includes a plurality of inverted Y-shaped beam inserts and a plurality of coupling elements configured to couple the plurality of inverted Y-shaped beam inserts to the first drive shaft.

[0056] The torsional vibration damper mechanism according to any one of the above items, wherein the first drive shaft, the second drive shaft, or both have a first oscillation mode, the third drive shaft has a second oscillation mode, and the second oscillation mode of the third drive shaft limits or reduces the first oscillation mode of the first drive shaft, the second drive shaft, or both.

[0057] The torsional vibration damper mechanism according to any one of the above items, wherein the position of the third drive shaft is adjustable relative to the position of the first drive shaft, the second drive shaft, or both to adjust torsional vibration damping.

[0058] A torsional vibration damper mechanism for suppressing torsional vibration of a first drive shaft, a second drive shaft, or both, the torsional vibration damper mechanism including an inner disk and a plurality of torque transmission struts configured to couple the first drive shaft or the second drive shaft to a third drive shaft, wherein the third drive shaft together with the torsional vibration damper mechanism is configured to reduce or substantially eliminate torsional vibration in the first drive shaft, the second drive shaft, or both.

[0059] The torsional vibration damper mechanism according to the above item, wherein the torsional vibration damper mechanism is disposed within a hollow cavity of the first drive shaft, a hollow cavity of the second drive shaft, or both.

[0060] The torsional vibration damper mechanism according to any one of the above items, wherein the inner disk of the torsional vibration damper mechanism has a hollow cavity and a plurality of slots for coupling the torsional vibration damper mechanism to the third drive shaft 81.

[0061] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of torque transmission struts are coupled to the inner disk at a first end and are coupled to the first drive shaft at a second end using a plurality of coupling elements.

[0062] The torsional vibration damper mechanism according to any one of the above items, further comprising a plurality of vibration damping inserts disposed in a cavity of the first drive shaft between the inner disk and the first drive shaft.

[0063] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of vibration damping inserts include a plurality of inverted Y-shaped beam inserts to couple the inner disk of the torsional vibration damper mechanism to the first drive shaft or the second drive shaft, or both.

[0064] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of inverted Y-shaped beam inserts are tuned for torsional vibration modes of interest in the first drive shaft or the second drive shaft.

[0065] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of vibration damping inserts include a plurality of damping elements.

[0066] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of damping elements are configured to couple the plurality of inverted Y-shaped beam inserts to the inner disk of the torsional vibration damper mechanism.

[0067] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of damping elements are disposed in grooves within the inner disk.

[0068] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of vibration damping inserts include a plurality of coupling elements configured to couple the plurality of inverted Y-shaped beam inserts to the first drive shaft or the second drive shaft.

[0069] The torsional vibration damper mechanism according to any one of the above items, wherein the plurality of damping elements include a viscoelastic material, a shape memory alloy (SMA), a spring, or a viscous fluid to provide spring compression and / or fluid friction damping.

[0070] According to another aspect of the present disclosure, a turbine engine includes a first drive shaft, a second drive shaft, and a torsional vibration damper mechanism that includes a third drive shaft mechanically coupled to the first drive shaft, the second drive shaft, or both. The third drive shaft is configured to reduce or substantially eliminate torsional vibrations in the first drive shaft, the second drive shaft, or both.

[0071] The turbine engine according to the above item, wherein the third drive shaft is directly coupled to the first drive shaft, the second drive shaft, or both.

[0072] The turbine engine according to any one of the above items, wherein the radius of the third drive shaft is less than the radius of the first drive shaft, the second drive shaft, or both, or the mass of the third drive shaft is greater than the mass of the first drive shaft, the second drive shaft, or both.

[0073] The turbine engine according to any one of the above items, wherein the torsional vibration damper mechanism further includes a mechanical coupling configured to mechanically couple the third drive shaft to the first drive shaft, the second drive shaft, or both.

[0074] The turbine engine according to any one of the above items, wherein the third drive shaft is a hollow drive shaft disposed within a cavity of the first drive shaft, the second drive shaft, or both.

[0075] A turbine engine according to any one of the preceding clauses, wherein the torsional vibration damper mechanism further comprises a plurality of vibration damping inserts disposed in the cavity between the third drive shaft and the first drive shaft, the second drive shaft, or both, the plurality of vibration damping inserts being configured to mechanically couple the third drive shaft to the first drive shaft, the second drive shaft, or both.

[0076] A turbine engine according to any one of the preceding clauses, wherein the plurality of vibration damping inserts comprises a plurality of inverted Y-shaped beam inserts configured to couple the third drive shaft to the first drive shaft, the second drive shaft, or both, wherein the plurality of inverted Y-shaped beam inserts is tunable for a torsional vibration mode of interest in the first drive shaft, the second drive shaft, or both.

[0077] A turbine engine according to any one of the preceding clauses, wherein the plurality of vibration damping inserts comprises a plurality of damping elements configured to couple the plurality of inverted Y-shaped beam inserts to the third drive shaft.

[0078] A turbine engine according to any one of the preceding clauses, wherein the plurality of damping elements comprises a viscoelastic material, a shape memory alloy (SMA), a spring, or a viscous fluid, or any combination thereof, to provide spring compression or fluid friction damping.

[0079] A turbine engine according to any one of the preceding clauses, further comprising a fan assembly, a low-pressure turbine assembly, and a low-pressure compressor assembly, wherein the low-pressure turbine assembly is coupled to the fan assembly and the low-pressure compressor assembly by the first drive shaft.

[0080] A turbine engine according to any one of the preceding clauses, further comprising a high-pressure turbine assembly and a high-pressure compressor assembly, wherein the high-pressure turbine assembly is coupled to the high-pressure compressor assembly by the second drive shaft.

[0081] Although the foregoing description is directed to preferred embodiments of the present disclosure, other variations and modifications will be apparent to those skilled in the art and may be made without departing from the spirit or scope of the present disclosure. Additionally, features described in connection with one embodiment of the present disclosure may be used in combination with other embodiments, even if not explicitly stated above.

Claims

1. A torsional vibration damper mechanism for suppressing torsional vibration of a first drive shaft, a second drive shaft, or both, characterized in that: The torsional vibration damper mechanism comprises: a third drive shaft mechanically coupled to the first drive shaft, the second drive shaft, or both, Wherein the third drive shaft is configured to reduce or substantially eliminate torsional vibrations in the first drive shaft, the second drive shaft, or both.

2. The torsional vibration damper mechanism according to claim 1, characterized in that: in, The third drive shaft is directly coupled to the first drive shaft, the second drive shaft, or both.

3. The torsional vibration damper mechanism according to claim 1, characterized in that: in, The radius of the third drive shaft is smaller than the radius of the first drive shaft, smaller than the radius of the second drive shaft, or smaller than both the radius of the first drive shaft and the radius of the second drive shaft.

4. The torsional vibration damper mechanism according to claim 1, characterized in that: in, The mass of the third drive shaft is greater than the mass of the first drive shaft, greater than the mass of the second drive shaft, or greater than both the mass of the first drive shaft and the mass of the second drive shaft.

5. The torsional vibration damper mechanism according to claim 1, characterized in that: Further included is a mechanical coupling configured to mechanically couple the third drive shaft to the first drive shaft, the second drive shaft, or both.

6. The torsional vibration damper mechanism according to claim 1, characterized in that: in, The first drive shaft, the second drive shaft, or both have a first oscillation mode, and the third drive shaft has a second oscillation mode, and the second oscillation mode of the third drive shaft limits or reduces the first oscillation mode of the first drive shaft, the second drive shaft, or both.

7. The torsional vibration damper mechanism according to claim 1, characterized in that: in, The position of the third drive shaft relative to the first drive shaft, the second drive shaft, or both, is adjustable to adjust torsional vibration damping.

8. The torsional vibration damper mechanism according to claim 1, characterized in that: in, The third drive shaft is a hollow drive shaft disposed within a cavity of the first drive shaft, the second drive shaft, or both.

9. The torsional vibration damper mechanism according to claim 8, characterized in that: Further comprising a plurality of vibration damping inserts disposed in the cavity between the third drive shaft and the first drive shaft, the second drive shaft, or both, the plurality of vibration damping inserts being configured to mechanically couple the third drive shaft to the first drive shaft, the second drive shaft, or both.

10. The torsional vibration damper mechanism according to claim 9, characterized in that in, The plurality of vibration damping inserts includes a plurality of inverted Y-beam inserts and a plurality of coupling elements configured to couple the plurality of inverted Y-beam inserts to the first drive shaft.

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