Systems and methods associated with a tuned vibration absorber

Abstract

An example tuned vibration absorber includes: a mass member; a base; and a flexible structure that couples the mass member to the base, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the base.

Description

Systems and Methods Associated with a Tuned Vibration AbsorberCROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to U.S. Provisional Patent Application No. 63 / 553,196, filed on February 14, 2024, and U.S. Provisional Patent Application No. 63 / 687,372, filed on August 27, 2024, the entire contents of all of which are herein incorporated by reference as if fully set forth in this description.BACKGROUND

[0002] A tuned vibration absorber (TVA) is a vibration control device that is added to a structure to provide a damping effect or to increase the impedance of a structure at a joint. Particularly, the TVA can be used to suppress resonance or attenuate the vibration of a structure at a particular forcing frequency.

[0003] In order to be effective, a TVA typically have a spring member, may be lightly damped, and is precisely tuned to a particular frequency. Thus, the TVA operates as a spring-mass system that vibrates at a particular frequency to cancel or attenuate vibrations of a vibrating device (e.g., an engine). As such, a TVA requires a stable tuned frequency and a stable damping level to provide the intended benefits.

[0004] Transmissibility can be defined as the ratio of an output to an input. For example, transmissibility can refer to the ratio of the force transmitted to the force applied. As such, transmissibility can be referred to as an amplification, where maximum amplification occurs when forcing frequency and natural frequency of a system coincide.

[0005] In some applications, it may be desirable to configure a TVA to have a high transmissibility (e.g., large mass response or movement relative to base input) to provide a significant force output that reduces the vibration. In these cases, it may be desirable for thetuned frequency of the TVA to remain unchanged when subjected to various environmental changes (e.g., environment temperature changes).

[0006] In some conventional TVAs, metal springs (e.g., coil springs, wave springs, or the like) are used. Such metal springs can provide high transmissibility but often have little damping, and thus high stresses may occur in the springs, leading to fatigue or failure. Further, such metal springs are difficult to manufacture in a manner that causes the springs to sustain motion without fatigue issues.

[0007] In other conventional TVAs, elastomeric springs are used. Such elastomeric springs may provide enhanced damping. However, such elastomeric springs are sensitive to temperature variation in both elastic and damping stiffnesses, and their tuned frequency and peak transmissibility thus change with temperature variations, which might not be desirable.

[0008] It may thus be desirable to have a TVA that can have high peak transmissibility at resonance and moderate damping to control or reduce stresses, while being minimally affected by temperature variations and being efficient to manufacture. It is with respect to these and other considerations that the disclosure made herein is presented.SUMMARY

[0009] The present disclosure describes implementations that relate to systems and methods associated with a tuned vibration absorber.

[0010] In a first example implementation, the present disclosure describes a tuned vibration absorber including: a mass member; an inner member disposed, at least partially, within the mass member such that an annular space is formed between the mass member and the inner member; and a flexible structure disposed in the annular space, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the inner member.

[0011] In a second example implementation, the present disclosure describes a tuned vibration absorber including: a mass member; a base; and a flexible structure that couples the mass member to the base, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the base.

[0012] In a third example implementation, the present disclosure describes an isolation system or assembly including the tuned vibration absorber of the first or second example implementation coupled to a structure.

[0013] In a fourth example implementation, the present disclosure describes a method of operating or using the tuned vibration absorber of the first or second example implementation.

[0014] In a fifth example implementation, the present disclosure describes a method of making the tuned vibration absorber of the first or second example implementation using additive manufacturing techniques.

[0015] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, implementations, and features described above, furtheraspects, implementations, and features will become apparent by reference to the figures and the following detailed description.BRIEF DESCRIPTION OF THE FIGURES

[0016] Figure 1 illustrates a cross-sectional side view of an isolation system including a TVA, according to an example implementation.

[0017] Figure 2 illustrates a perspective view of the TVA of Figure 1, according to an example implementation.

[0018] Figure 3 illustrates a perspective cross-sectional view of the TVA of Figure 2, according to an example implementation.

[0019] Figure 4 illustrates a partial perspective cross-sectional view of the TVA of Figure 2, according to an example implementation.

[0020] Figure 5 illustrates another partial perspective cross-sectional view of the TVA of Figure 2, according to an example implementation.

[0021] Figure 6 illustrates a partial cross-sectional side view of the TVA of Figure 2, according to an example implementation.

[0022] Figure 7 illustrates a cross-sectional elevational view of the TVA of Figure 2, according to an example implementation.

[0023] Figure 8A illustrates a top view of a junction plate, according to an example implementation.

[0024] Figure 8B illustrates a TVA having the junction plate of Figure 8A coupling a plurality of spring columns to a mass member of the TVA, according to an example implementation.

[0025] Figure 8C illustrates a top view of another junction plate, according to an example implementation.

[0026] Figure 9 illustrates a partial top view of a TVA, according to an example implementation.

[0027] Figure 10A illustrates a partial top view of a TVA, according to an example implementation.

[0028] Figure 10B illustrates a shape of a cross section of a column of a plurality of columns of the TVA of Figure 10A, according to an example implementation.

[0029] Figure 11 A illustrates a partial perspective view of the TVA of Figure 2 in an unfinished state, according to an example implementation.

[0030] Figure 11B illustrates a partial cross-sectional elevational view of the TVA of Figure 11 A in the unfinished state, according to an example implementation.

[0031] Figure 12 illustrates a partial cross-sectional elevational view of the TVA after machining some features, according to an example implementation.

[0032] Figure 13 illustrates a partial perspective view of a TVA in an unfinished state, according to an example implementation.

[0033] Figure 14 is a flowchart of a method for using or operating a TVA, according to an example implementation.

[0034] Figure 15A illustrates a perspective view of a TVA, according to an example implementation.

[0035] Figure 15B illustrates a perspective cross-sectional view of the TVA of Figure 15 A, according to an example implementation.DETAILED DESCRIPTION

[0036] Disclosed herein is a TVAthat can achieve high peak transmissibility at resonance and moderate damping to control or reduce stresses, while being minimally affected by temperature variations and being efficient to manufacture.

[0037] Figure 1 illustrates a cross-sectional side view of an isolation system 10 including a TVA 100, according to an example implementation. The isolation system 10 including the TVA 100 is configured to reduce dynamic vibration transmitted between a vibrating member (e.g., an engine; not shown), and a supporting structure 12 (e.g., an aircraft yolk, spar, or beam structure).

[0038] The isolation system 10 and the TVA 100 are effective at a predetermined operating frequency “fo” but is also effective within a narrow range about “fo.” In an example, “fo” coincides with a predominant disturbance frequency, such as the cruise frequency of an aircraft engine. It may be desirable, that the range of isolation encompasses normal variations in engine speed, for example, variations in engine speed due to cruise, takeoff, and landing maneuvers.

[0039] It should be understood that the isolation system 10 having the TVA 100 can be used in any application where any vibrating member is attached to a structure. In particular, it should be understood that the TVA 100 may be used as a stand-alone apparatus. For example, the TVA 100 may be directly attached to any vibrating machinery or vehicle component, etc. that is vibrating in three directions to absorb vibrations thereof.

[0040] In an example, the TVA 100 is tuned such that it exhibits a first resonant frequency “fni” in a first direction and a second resonant frequency “fnf’ in a second direction, where each of these frequencies is tuned such that it occurs slightly below the most common operating frequency “fo.” In an example, both frequencies may be the same.

[0041] Figure 2 illustrates a perspective view of the TVA 100, and Figure 3 illustrates a perspective cross-sectional view of the TVA 100, according to an example implementation. The TVA 100 has a mass member 102, an inner member 104, a flexible structure 106, an outer base plate 108, and an elastomeric member 110. In the example implementation of Figures 1- 3, the TVA 100 is clamped to the supporting structure 12 via a rod 14, which is inserted through the inner member 104, and nut 16, for example. The outer base plate 108 and the elastomeric member 110 of the TVA 100 are not shown in Figure 1 to reduce visual clutter in the drawing, but it should be understood that the TVA 100 in Figure 1 can include these components.

[0042] Referring to Figures 2-3, the mass member 102 has a generally cylindrical body and is hollow (has a cylindrical central cavity therein) as shown. The mass member 102 can be made of a metallic material and its mass or weight is tuned to vibrate at a particular frequency to counteract, attenuate, or cancel vibrations.

[0043] The inner member 104 is also generally cylindrical and is disposed, at least partially, within the central cavity of the mass member 102 such that an annular space 112 is formed between the mass member 102 and the inner member 104. The inner member 104 can also be hollow as depicted. The inner member 104 has a base 114 that radially extends outward to interface with the outer base plate 108 as shown.

[0044] In an example, the inner member 104 is configured to be coupled to a structure (e.g., the supporting structure 12 shown in Figure 1) to which a vibrating device is attached. In this example, the TVA 100 is configured such that the mass member 102 vibrates at a resonant frequency that cancels resonant vibration of the vibrating device.

[0045] The elastomeric member 110 (e.g., rubber component or the like) is axially interposed between the bottom surface of the mass member 102 and the outer base plate 108 as shown.The elastomeric member 110 can be bonded to one or both of the mass member 102 and theouter base plate 108, for example. The elastomeric member 110 is configured to operate as a damping element.

[0046] The flexible structure 106 is disposed in the annular space 112 and flexibly interconnects the inner member 104 to the mass member 102. Particularly, the flexible structure 106 is attached or coupled to the inner member 104, by being attached to the base 114 for example, and is also coupled to the mass member 102.

[0047] Figure 4 illustrates a partial perspective cross-sectional view of the TVA 100, Figure 5 illustrates another partial perspective cross-sectional view of the TVA 100, and Figure 6 illustrates a partial cross-sectional side view of the TVA 100, according to an example implementation. In Figures 4-6, a portion of the mass member 102 is removed to reveal details of the flexible structure 106. Figures 4-6 are described together.

[0048] In the example implementation of Figures 4-6, the flexible structure 106 includes a plurality of columns 116 configured as cantilever beams operating as spring members. In an example, as shown, the plurality of columns 116 can include concentric sets of columns in a circular pattern, such as outer set of columns 118 and inner set of columns 120 shown in Figure 5. More or fewer sets of columns can be used. Also, columns might not be concentric, and might not be arranged in a circular pattern in other implementations.

[0049] Figure 7 illustrates a cross-sectional elevational view of the TVA 100, according to an example implementation. Referring to Figures 4-7 together, respective first ends (e.g., proximal end 119 in Figure 7) of a first subset of the columns such as column 122 are attached to or made integral with the base 114 of the inner member 104. On the other hand, respective first ends (proximal end 121 in Figure 7) of a second subset of columns such as column 124 are attached to or made integral with the mass member 102.

[0050] While respective first ends (proximal ends 119, 121) of the plurality of columns 116 are attached to either the base 114 or the mass member 102, respective second ends 125 of the plurality of columns 116 are connected or coupled to at least one junction plate 126 shown in Figures 4, 7. As such, the respective second ends 125 of the plurality of columns 116 move together by virtue of being coupled to the junction plate 126 such that the plurality of columns 116 are configured as guided-end cantilever beams. The junction plate 126 can provide increased motion capability and lower stiffness, for example.

[0051] As mentioned above, multiple sets of columns can be used in the flexible structure 106. In an example, one junction plate can tie or couple two sets of columns, e.g., the junction plate 126 coupling the outer set of columns 118 and the inner set of columns 120. In an example, more sets of columns and more junction plates can be used. In such examples, if there are N sets of columns, an N-l number of junction plates can be used. However, other arrangements are contemplated.

[0052] With the configuration shown in in the figures, the plurality of columns 116 are blended or integrated at both ends to minimize stress concentration (see Figure 7 for example). In one example, the respective second ends 125 of the plurality of columns 116 where they attach or couple to the junction plate 126 can be filleted and they blend with the junction plate 126 to reduce stress.

[0053] Further, in an example, additive manufacturing techniques, such as three-dimensional (3D) printing powder fusion techniques, can be used to make the TVA 100. In this example, having the filleted ends can minimize the angles at the connection between the plurality of columns 116 with the junction plate 126 to facilitate printing such a support-less structure.

[0054] Referring to Figure 5, for example, the space or clearance around and between the plurality of columns 116, the mass member 102, and the inner member 104 allow for movementand flexing of the plurality of columns 116. This way, the flexible structure 106 (e.g., the plurality of columns 116) provide spring-like characteristics for the TVA 100.

[0055] Figure 7 illustrates an axial direction 128, a first radial direction 130, and a second radial direction 132, all perpendicular to each other. The flexible structure 106 can flex in both radial directions 130, 132, for example.

[0056] In one example, the TVA 100 can have a particular natural frequency in the axial direction 128, and the TVA 100 (e.g., the mass member 102 and the flexible structure 106) can be configured or tuned to respond and provide vibration absorption in one or both of the radial directions 130, 132. In an example, the natural frequency in the axial direction 128 can be established well above the tuned frequency in the radial directions.

[0057] In examples, a junction plate can be configured in a manner that facilitates tuning the natural frequencies in two or three directions. Particularly, a junction plate can be configured (e.g., as a truss structure representing an open lattice or other configurations as described below) to provide a controlled stiffness along with the flexible structure 106 (e.g., the plurality of columns 116) to allow tuning all three directions (the axial direction 128, the first radial direction 130, and the second radial direction 132) either at the same frequency or at specific different desired frequencies. In these examples, the junction plate may connect the ends of the plurality of columns 116 to the mass member 102.

[0058] Figure 8A illustrates a top view of a junction plate 300, according to an example implementation. The junction plate 300 represents an alternative to the junction plate 126, for example. Also, while the junction plate 126 connects the ends of the plurality of columns 116 to each other, the junction plate 300 connects the ends of the plurality of columns 116 to the mass member 102 as described below with respect to Figure 8B.

[0059] In the example implementation of Figure 8A, the junction plate 300 is configured as a disk 302 (e.g., a flat, slotted disk) having a plurality of radial slots 304 formed in a circular array about the disk 302. The junction plate 300 can be 3D-printed on a laser powder bed with slot cut at the top. A pressured ring-shaped retainer can be used to join the junction plate 300 to the mass member 102.

[0060] While the plurality of columns 116 of the TVA 100 are stiff in the axial direction 128, and react primarily in the radial directions 130, 132 by bending, the junction plate 300 is capable of flexing axially. The junction plate 300 may be stiff in a radial direction, but is configured to permit flexing and axial motion. This way, the mass member 102 can respond axially on the junction plate 300, while the mass member 102 and the junction plate 300 respond radially together at the same time. This way, the radially-moving mass is larger than the axially-moving mass as the radially-moving mass includes the junction plate 300.

[0061] Natural frequencies in the axial direction 128 and the radial directions 130, 132 can be a stepped approach. First, mass can be added or moved to the mass member 102 to achieve desired axial frequency. Such added or removed mass, however may affect radial tuning. To compensate for such change in radial tuning frequency and to achieve a particular radial tuning frequency, mass can be added or removed from an inboard side 306 of the junction plate 300. A flexing length 308 of the flexure element of the junction plate 300 can also be adjusted to achieve particular frequencies.

[0062] Figure 8B illustrates a TVA 310 having the junction plate 300 coupling the plurality of columns to the mass member 102, according to an example implementation. As shown, the junction plate 300 extends radially to an outer perimeter of the TVA 310. A band 312 couples the junction plate 300 to the mass member 102.

[0063] Further, in the example implementation of Figure 8B, the TVA 310 includes a tube 314 that couples the junction plate 300 to another junction plate 316 that is configured similar to the junction plate 300. With this configuration, the junction plates 300, 316 allow for axial flexiing while being stiff in a radial / lateral direction, while the plurality of columns 116 are stiff in the axial direction, but allow flexing in the radial / lateral direction.

[0064] Other configurations of the junction plate can be used.

[0065] Figure 8C illustrates a perspective view of a junction plate 400, according to an example implementation. The junction plate 400 represents an alternative to the junction plate 126, for example. In the example implementation of Figure 8C, the junction plate 400 is configured as a disk 402 having a plurality of flexure elements 404 formed in a circular array about the disk 402, with gaps 406 (e.g., triangular-shaped gaps as shown) therebetween. As shown, the flexure elements 404 can each be generally shaped as a fork having flat members that are interleaving with each other. As such, the disk 402 can also be considered as a slotted disk with an alternative configuration to the junction plate 300.

[0066] Each of the flexure elements 404 can have a flexing length 408, which relates to the stiffness and amount of movement permissible for a given material. Longer flexing lengths may achieve softer spring rates and tuning to a lower natural frequency. Such longer flexing lengths may also reduce stresses under high input deflection and mass response.

[0067] The junction plate 400 can replace the junction plate 300 in Figure 8B and may be configured to couple the plurality of columns 116 to the mass member 102. Also, it may be connected via the tube 314 to a bottom junction plate that is configured similar to the junction plate 400.

[0068] As such, the junction plate 126, 300, 400 can be configured to have a particular structure that provides different directional stiffnesses, thus rendering the TVA 100 tunable in threedirections. Although the junction plate 126 is used in the description below and other Figures, it should be understood that the junction plate 300, 400 can be used in any of the configurations described herein.

[0069] Referring back to Figure 7, in an example, the outer base plate 108 can be press fitted or otherwise coupled to the base 114 of the inner member 104. This configuration allows transmission of load in the radial directions 130, 132.

[0070] Although the plurality of columns 116 (e.g., the outer set of columns 118 and the inner set of columns 120) are shown to be formed in circular arrays or patterns, other configurations are contemplated.

[0071] Figure 9 illustrates a partial top view of the TVA 100, according to an example implementation. As shown in Figure 9, instead of circular arrays, the outer set of columns 118 and the inner set of columns 120 may be formed in an elliptical array. Other patterns (e.g., rectangular, square, etc.) are possible. Further, although the plurality of columns 116 are each shown to have a circular cross section, other cross section shapes can be used.

[0072] Figure 10A illustrates a partial top view of the TVA 100, and Figure 10B illustrates a shape of a cross section of a column of the plurality of columns 116, according to an example implementation. As shown in Figure 10A, instead of circular cross-section, the plurality of columns 116 can have other shapes such as an elliptical cross section. Other cross sectional shapes (e.g., rectangular, square, irregular, etc.) are contemplated.

[0073] As such, in some examples, the cross-sectional shape of the respective columns of the plurality of columns 116 can be asymmetric. As schematically depicted in Figure 10B, an asymmetric cross-sectional shape allows different stiffness, and therefore tuning, in a first direction 134 (e.g., the first radial direction 130) compared to a second direction 136 (e.g., the second radial direction 132).

[0074] In examples, the cross-sectional shape of the respective columns of the plurality of columns 116 may vary along a length of the column (in the axial direction 128). This way, the stiffness of the plurality of columns 116 can further be tuned as desired. As such, the number, shape, and configuration of the plurality of columns 116 can be tuned to achieve a particular resonant frequency for the mass member 102, for example.

[0075] As mentioned above, the configuration of the TVA 100 may facilitate making the TVA 100 via additive manufacturing processes such as 3D printing. Using such additive manufacturing methods may enable the TVA 100 to have no mechanical joints between the flexible structure 106 (e.g., the plurality of columns 116) and the mass member 102. These methods may also permit the TVA 100 to have a compact configuration with any shape or size that can provide an enhanced or optimal stiffness.

[0076] A 3D printing manufacturing process may generally involve construction of the TVA 100 from a Computer-Aided Design (CAD) model or a digital 3D model. 3D printing can be accomplished by a variety of processes in which material is deposited, joined or solidified under computer control, with the material being added together, typically layer by layer.

[0077] In a particular example, a Powder Bed Fusion (PBF) 3D printing additive manufacturing process can be used. A PBF process may include using different printing techniques such as direct metal laser sintering (DMLS), electron beam melting (EBM), selective heat sintering (SHS), selective laser melting (SLM), or selective laser sintering (SLS).

[0078] Thus, the PBF method can use either a laser or electron beam to melt and fuse material powder together. PBF processes involve the spreading of the powder material over previous layers. There are different mechanisms to enable this, including a roller or a blade. A hopper or a reservoir below or aside the powder bed provides material supply.

[0079] As an example, making the TVA 100, which is made of metals for instance, may involve sintering the powder, layer by layer. In a selective heat sintering process, a heated thermal print head is used to fuse powder material together. Layers are added with a roller in between fusion of layers. A platform lowers the TVA accordingly as printing progresses.

[0080] As an example, a PBF process for making the TVA 100 from a 3D model may generally involve spreading a layer (e.g., having a thickness of 0.1 millimeter) of material over the build platform. A laser is then applied to fuse the first layer or first cross section of the model. A new layer of powder can then be spread across the previous layer using a roller. Further layers or cross sections are fused and added. The process repeats until the TVA 100 is substantially formed. Additional features of the TVA 100 can then be machined as described below.

[0081] In an example, loose, unfused powder remains in position but can be removed during post processing. In an example, when the 3D printing process is completed, the TVA 100 might not be in its final form, and further processing may be performed.

[0082] Figure 11 A illustrates a partial perspective view of the TVA 100 in an unfinished state, and Figure 11B illustrates a partial cross-sectional elevational view of the TVA 100 in the unfinished state, according to an example implementation. In Figure 11 A, a portion of the mass member 102 is removed to reveal inner details of the TVA 100.

[0083] Figures 11A-11B show the TVA 100 in an as-printed configuration (after the 3D printing process is performed). After printing, the TVA 100 can be heat-treated using hot isostatic pressure, for example, which can be used to improve fatigue performance and enable the TVA 100 to withstand higher stresses therein.

[0084] As shown in the example as-printed configuration of Figures 11 A-l IB, the plurality of columns 116 may be printed in their final form. However, some features can then be machinedto finalize the TVA 100. This way, additive manufacture processes with support-less structure can be facilitated. Optimization for 3D printing can minimize subsequent machining.

[0085] Figure 12 illustrates a partial cross-sectional elevational view of the TVA 100 after machining some features, according to an example implementation. Comparing Figure 12 to Figure 11B, a bottom portion of the mass member 102 is machined to remove some material and form the base 114 of the inner member 104.

[0086] Further, internal features of the inner member 104 can be formed or machined. For example, a through-hole 138 may be drilled into the inner member. A chamfer 140 may then be machined on the interior surface of the inner member 104 as shown. As such, the 3D printing process may be simplified, while final details or features can be machined subsequently.

[0087] As shown, in this example, the mass member 102, the inner member 104, and the flexible structure 106 are integral with each other in a unitary construction configuration. The outer base plate 108 and the elastomeric member 110 can then be added to complete construction of the TVA 100.

[0088] As mentioned above, the elastomeric member 110 is used to impart damping characteristics of the TVA 100. In some example, other damping features can be added to facilitate tuning the performance of the TVA 100.

[0089] Figure 13 illustrates a partial perspective view of a TVA 200 in an unfinished state, according to an example implementation. The TVA 200 is similar to the TVA 100 in several features, and common components are labeled with the same reference numbers.

[0090] The TVA 200 has a mass member 202 that differs from the mass member 102 in that the mass member 202 in this example implementation can have one or more internal cavities formed therein during manufacturing (e.g., during the 3D printing additive manufacturingprocess). For example, the mass member 202 can have four internal cavities disposed in a circular array within the mass member 202.

[0091] A portion of the mass member 202 is not shown in Figure 13 to reveal two of the internal cavities, internal cavity 204 and internal cavity 206. In an example, the internal cavities can be separated by respective barriers. For instance, the internal cavities 204, 206 are separated by a barrier 208 as shown. More or fewer internal cavities can be used as desired.

[0092] In an example, the internal cavities (e.g., the internal cavities 204, 206) contain solid particles. These solid particles provide damping characteristics to the TVA 200 and can facilitate controlling peak resonance transmissibility of the TVA 200. The number and shape of internal cavities can vary as desired to tune damping, mass, and transmissibility of the TVA 200.

[0093] In one example, the mass member 202 include access ports, openings, or holes (e.g., longitudinal holes), such as hole 210 and hole 212, to provide access to and from the respective internal cavities. Particularly, the holes (e.g., the holes 210, 212) facilitate removal of metal powder after the 3D printing additive manufacture process is completed.

[0094] The holes (e.g., the holes 210, 212) can also be used to insert particles into the respective internal cavities for damping. In an example, the holes can be used to insert heavy metal material particles (e.g., bismuth, cast or powder, tungsten powder, etc.) to increase mass, while allowing for optimal material selection (e.g., stainless steel 15-5PH) for the flexible structure 106 (e.g., the plurality of columns 116), the inner member 104, and the junction plate 126.

[0095] In an example, during the additive manufacturing process, particles could be fused inside the internal cavities in a structure of a particular shape such as pyramid-type structure or pyramid-shaped structure or other shapes, with mostly unfused powder surrounding such structure. Some or all of the unfused powder can then be removed from the internal cavity,thereby creating space for movement of the particles, enabling particle-type damping. In this example, diameters of the holes (e.g., the holes 210, 212) is made smaller than the diameter of the particles such that the particles are retained within the internal cavities. In an example, the holes (e.g., the holes 210, 212) can be plugged after insertion of the particles, e.g., via press- fitted plugs or the like.

[0096] In one example, during the additive manufacturing process, particles can be fused inside the internal cavities as spheres or other shapes, with mostly unfused powder surrounding them. Some or all of the unfused powder can then be removed from the internal cavities creating space for movement of the particles enabling particle-type damping as mentioned in the example above. The holes (e.g., the holes 210, 212), inertial forces, or ultrasonic vibration can be used to separate or break apart any joining of the particles, such that the particles can move independently.

[0097] In another example, the mass member 202 might not include holes. In this example, to save time and cost of the additive manufacturing process, the internal cavities can be filled with unfused powder, where the powder operates as a mass included in the mass member 202. In one example, the outer shell of the mass member 102 surrounding the internal cavities may have a different density compared to a respective density of the particles in the internal cavities, allowing for lower energy and less time for the fusing process.

[0098] The configurations of the TVAs 100, 200 may provide several advantages over conventional TVAs. Conventional TVAs having metal springs have low damping, and can thus have high transmissibility (large motion of the mass member), which leads to large stresses. For example, some metal springs have shown transmissibility of greater than 50 at resonance, and such high transmissibility can lead to fatigue or failure. On the other hand, elastomeric springs may have lower transmissibility (because of their higher damping) but suffer from sensitivity to temperature variations compared to metal springs, which render theirperformance inconsistent. For example, a spring made of steel may show variations of about2% over a temperature range between -65°F and 350°F. This variation is due to the small change in material modulus of the metal relative to temperature. In the same temperature range, elastomeric materials can exhibit a change in modulus of greater than 30%. This large modulus change can cause changes in the tuned frequency of the TVA and can be detrimental.

[0099] With the configuration of the TVAs 100, 200, using the flexible structure 106 having the plurality of columns 116 as metal cantilever beams providing spring-like characteristics in bending may provide low damping, which can result in high transmissibility (large motion of the mass member 102). However, with the flexible structure 106 being a metallic spring, temperature sensitivity is limited. Further, the elastomeric member 110 provides damping characteristics as described above. As such, the TVAs 100, 200 may provide the benefits of both metallic and elastomeric springs.

[0100] Particularly, the TVAs 100, 200, despite using the elastomeric member 110, may provide a stable performance over temperature. This is due to the fact that the elastomeric material of the elastomeric member 110 provides only a portion of the stiffness of the combined spring supporting the mass member 102, as the flexible structure 106 provides the other portion of stiffness.

[0101] Further, any change in the modulus of the elastomeric member 110 might have a reduced impact on the damping characteristics of the combined TVA. 110. For this reason, the elastomeric member 110 can be selected to have high damping characteristics, and may thus provide the damping required to control the peak transmissibility at resonance (e.g., to be limited between 7-40), with less overall sensitivity to temperature variation due to the flexible structure 106 being metallic.

[0102] As an example for illustration only, table 1 below shows the stiffnesses to support a mass with changes from 68°F to 5°F. The elastomeric member 110 exhibits an increase of 20% in the elastic modulus and 10% in the damping modulus, while the final combined stiffness change is only 4% with final transmissibility above 13 at resonance. The change in tuned frequency for a purely elastomeric spring might have been larger, e.g., a 20% change as noted above. The use of a low damping elastomer without a metallic spring to achieve the high transmissibility at resonance at both 68°F and 5°F temperatures might not be possible, while the TVAs 100, 200 are capable of achieving such performance targets.Table 1

[0103] For calculations of table 1, the stiffness is normalized relative to the elastomer elastic stiffness, a single degree of freedom mass system is assumed and a unity mass used. Changes in elastomer properties are representative for typical elastomer materials.

[0104] However, in some examples, such as applications involving vibratory environments with low input vibration (e.g., 1G or less input vibration), the TVAs 100, 200 may be used without the elastomeric member 110.

[0105] Further, the use of particle damping inside the mass member 102 as described above with respect to the TVA 200 may permit the addition of damping to control the peaktransmissibility at resonance to the desired range of about 7-40 without having to use the elastomeric member 110. Particle damping, which involves using metal particles, may be less sensitive to temperature and may enable the TVA 200 to be more stable in tuned frequency and peak transmissibility at resonance.

[0106] Also, the use of particle damping and stainless steel for the plurality of columns 116 may allow expansion of the temperature range that the TVA 200 can operate within. Conventional elastomeric materials might not be able to operate at temperatures above 350°F without loss in strength properties, which affects performance. With particle damping using 15-5PH stainless steel particles, for example, the TVA 200 may be capable of operating in a temperature range from -300°F to 600°F. In an example, using an Inconel 718 type material (e.g., a Nickel alloy) for the TVA 200 and high temperature metallic particles can extend the operating temperature range to well above 1000°F.

[0107] Further, particle size and number as well as the shape of the internal cavities (e.g., the internal cavities 204, 206) can be adjusted to obtain the desired damping characteristics. Particle damping may be particularly advantageous as it might provide increased damping as the mass response increases within limits. Under low input vibrations, the particles may provide limited damping, but the higher transmissibility at resonance under this low input condition might not create excessive stress in the plurality of columns 116. As the input increase, the particles may react and generate higher damping, limiting the response (the magnitude or amplitude of movement of the mass member 102) and protecting the plurality of columns 116 from large stresses.

[0108] Particles of a certain mass can be 3D printed as mentioned above. The plurality of columns 116 can be configured with a certain stiffness and the particles may have a defined mass, and therefore a discrete frequency of the TVA may be excited at a particular frequencyto provide a resonant peak and purposely separate the particle mass from the flexible structure106.

[0109] In examples, the internal cavities may be used without particle damping. In these examples, the internal cavities may provide a discrete tunable function by changing the powder density to whatever is desired to tune the performance of the TVA.

[0110] Further, the configuration of the plurality of columns 116 of the flexible structure 106 can be adjusted or tuned to avoid fatigue damage due to vibratory input at the tuned frequency. For instance, for high input vibration levels for a given required mass, the length of the columns can be increased, or more sets of columns may be added, or the allowed peak transmissibility is limited to reduce stresses. The plurality of columns 116 are operating generally as guided- end cantilever beams in bending with generally fully reversing fatigue stresses.

[0111] Further, the configuration of the TVAs 100, 200 has redundant columns that share the load and an interlocking assembly, which prevents the mass member 102 and the inner member 104 from completely separating from each other. Thus, this configuration is inherently damage-tolerant, which provides a safety improvement and structural integrity. Also, the plurality of columns 116 are contained in a way that provides an increased measure of safety from damage due to shipping and handling.

[0112] Figure 14 is a flowchart of a method 500 for using or operating the TVA 100, according to an example implementation. For example, the method 500 can be implemented to couple the TVA 100 to the supporting structure 12 to which a vibrating device is mounted to operate the isolation system 10.

[0113] The method 500 may include one or more operations, or actions as illustrated by one or more of blocks 502-504. Although the blocks are illustrated in a sequential order, these blocks may in some instances be performed in parallel, and / or in a different order than thosedescribed herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and / or removed based upon the desired implementation.

[0114] At block 502, the method 500 includes providing the TVA 100 having the mass member 102; the inner member 104 disposed, at least partially, within the mass member 102 such that the annular space 112 is formed between the mass member 102 and the inner member 104; and the flexible structure 106 disposed in the annular space 112, wherein the flexible structure 106 comprises a plurality of columns 116 configured as cantilever beams operating as spring members that flexibly interconnect the mass member 102 to the inner member 104. The term “providing” as used herein, and for example with regard to the TVA 100 or other components, includes any action to make the TVA 100 or any other component available for use, such as bringing the TVA 100 to an apparatus or to a work environment for further processing (e.g., mounting other components).

[0115] At block 504, the method 500 includes coupling the inner member 104 to the supporting structure 12 to which a vibrating device is mounted or attached. For example, the inner member 104 can be clamped to the supporting structure 12 via the rod 14, which is inserted through the inner member 104, and nut 16, as shown in Figure 1.

[0116] The method 500 can further include any of the steps or operations described above.

[0117] Although the configurations shown in Figures 1-13 and the method of Figure 14 are directed to an example implementation where the flexible structure 106 (e.g., the plurality of columns 116) is disposed within the mass member 102 or in the annular space 112 between the mass member 102 and the inner member 104, it is contemplated that a flexible structure similar to the flexible structure 106 can be mounted external to a mass member and operate in a similar manner.

[0118] Figure 15A illustrates a perspective view of a TVA 600, and Figure 15B illustrates a perspective cross-sectional view of the TVA 600, according to an example implementation. The TVA 600 includes a mass member 602, base 604, and a flexible structure 606 mounted external to the mass member 602. In an example, the mass member 602 can be mounted to the base 604 or can be integral with the base 604 (e.g., unitary construction). The flexible structure 606 can include a plurality of columns connecting the mass member 602 to the base 604 as depicted.

[0119] In examples, an elastomeric member (not shown; similar to the elastomeric member 110) can be mounted to the base 604 (underneath the base 604) such that when the base 604 is mounted to a component to dampen or controls its vibration, the elastomeric member is interposed between the base 604 and the component. In other examples, the elastomeric member may be disposed between the mass member 602 and the base 604. The elastomeric member reacts in shear, for example.

[0120] In one example, the mass member 602 can be cylindrical like the mass member 102 or the mass member 202. In the example implementation of Figures 15A-15B, the mass member 602 is generally formed as a rectangular prism 608 having a circular plate 610 formed at its end. The mass member 602 may include a conical or tapered portion 612 that connects the rectangular prism 608 to the circular plate 610. The shape of the mass member 602 is not meant to be limiting and can be configured to have other shapes.

[0121] The mass member 602 can be made of a metallic material and its mass or weight is tuned to vibrate at a particular frequency to counteract, attenuate, or cancel vibrations.

[0122] In an example, the base 604 is configured to be coupled to a structure (e.g., the supporting structure 12 shown in Figure 1) to which a vibrating device is attached. In thisexample, the TVA 600 is configured such that the mass member 602 vibrates at a resonant frequency that cancels resonant vibration of the vibrating device.

[0123] The flexible structure 606 is disposed external to the mass member 602 and is configured to flexibly interconnect the base 604 to the mass member 602. Particularly, the flexible structure 606 is attached or coupled to both the base 604 and the mass member 602.

[0124] In the example implementation of Figures 15A-15B, the flexible structure 606 includes a plurality of columns. For instance, as depicted, the flexible structure 606 includes column 614, column 616, column 618, and column 620. However, more or fewer columns can be used.

[0125] The columns 614-620 can be configured as cantilever beams operating as spring members. Particularly, the columns 614-620 are connected at one end (bottom end in Figures 15A-15B) to the base 604 (which can be mounted to a vibrating device), while being connected at the other end (top end) to the circular plate 610 of the mass member 602, with the circular plate 610 being free to move. The circular plate 610 can operate as any of the junction plates described above, e.g., the junction plates 126, 300, 400.

[0126] Particularly, the TVA 600 can have extensions or ears such as ear 622 protruding radially from the circular plate 610, and the column 614-620 are connected at their ends to such ears (e.g., the column 614 is coupled to the ear 622). With this configuration, the columns 614- 620 are configured as guide-ended cantilever beams. More or fewer sets of columns can be used, and different patterns and spacing might be used.

[0127] The columns 614-620 provide a controlled stiffness in the a plane perpendicular to the length of the columns. The controlled stiffness in the plane perpendicular to the length of the columns allows for the mass member 602 to have a natural frequency in this plane at a desired value (e.g., between 50 and 500 Hz). The high stiffness in the columns 614-620 along theirlength and the spacing of the columns 614-620 keeps the cocking modes above the translational natural frequencies.

[0128] Referring to Figure 15B, the mass member 602 may be hollow, having an internal space 624 formed therein. The mass member 602 may also have a hole 626 formed in the circular plate 610 and the tapered portion 612 to provide a path to the internal space 624. The hole 626 can be used to insert or introduce particles into to the internal space 624 of the mass member 602. Such particles can be similar to the particles described above with respect to the TVA 200 of Figure 13 and may operate in a similar manner.

[0129] The size of the hole 626 is based on the size of the particles to be introduced into the internal space 624. After the particles are inserted into the intern space 624, a plug can be press fitted or threaded into the hole 626 to plug it.

[0130] The TVA 600 can also be made using additive manufacturing techniques as described above with respect to the TVAs 100, 200.

[0131] It should be noted that the mass member 602 can be configured similar to the mass member 102 or the mass member 202 described above. The base 604 can also be configured similar to any of the inner masses described above. Also, the flexible structure 606 and the columns 614-620 can be similar to the flexible structure 106 and the plurality of columns 116 described above.

[0132] As such, whether the flexible structure is mounted within an annular space between a mass member and an inner member (e.g., the TVAs 100, 200) or mounted external to the mass member (e.g., the TVA 600), the disclosed TVAs generally have a mass member coupled to a base, which can be mounted to a vibrating device, with a flexible structure (e.g., plurality of columns) configured to flexibly interconnect the mass member to the base.

[0133] The detailed description above describes various features and operations of the disclosed systems with reference to the accompanying figures. The illustrative implementations described herein are not meant to be limiting. Certain aspects of the disclosed systems can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.

[0134] Further, unless context suggests otherwise, the features illustrated in each of the figures may be used in combination with one another. Thus, the figures should be generally viewed as component aspects of one or more overall implementations, with the understanding that not all illustrated features are necessary for each implementation.

[0135] Additionally, any enumeration of elements, blocks, or steps in this specification or the claims is for purposes of clarity. Thus, such enumeration should not be interpreted to require or imply that these elements, blocks, or steps adhere to a particular arrangement or are carried out in a particular order.

[0136] Further, devices or systems may be used or configured to perform functions presented in the figures. In some instances, components of the devices and / or systems may be configured to perform the functions such that the components are actually configured and structured (with hardware and / or software) to enable such performance. In other examples, components of the devices and / or systems may be arranged to be adapted to, capable of, or suited for performing the functions, such as when operated in a specific manner.

[0137] By the term “substantially” or “about” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those with skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0138] The arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, operations, orders, and groupings of operations, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

[0139] While various aspects and implementations have been disclosed herein, other aspects and implementations will be apparent to those skilled in the art. The various aspects and implementations disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims, along with the full scope of equivalents to which such claims are entitled. Also, the terminology used herein is for the purpose of describing particular implementations only, and is not intended to be limiting.

[0140] Embodiments of the present disclosure can thus relate to one of the enumerated example embodiments (EEEs) listed below.

[0141] EEE 1 is a tuned vibration absorber comprising: a mass member; an inner member disposed, at least partially, within the mass member such that an annular space is formed between the mass member and the inner member; and a flexible structure disposed in the annular space, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the inner member.

[0142] EEE 2 is the tuned vibration absorber of EEE 1, wherein the mass member is generally cylindrical and hollow, thereby forming a cylindrical central cavity in which the inner member is disposed, at least partially.

[0143] EEE 3 is the tuned vibration absorber of any of EEEs 1-2, wherein the inner member is generally cylindrical and comprises a base extending radially outward, wherein the tuned vibration absorber further comprises: an outer base plate disposed about the base of the inner member.

[0144] EEE 4 is the tuned vibration absorber of EEE 3, further comprising: an elastomeric member that is axially interposed between the mass member and the outer base plate.

[0145] EEE 5 is the tuned vibration absorber of any of EEEs 1-4, wherein the plurality of columns of the flexible structure comprises concentric sets of columns disposed in the annular space.

[0146] EEE 6 is the tuned vibration absorber of EEE 5, wherein the concentric sets of columns comprise at least an outer set of columns and an inner set of columns.

[0147] EEE 7 is the tuned vibration absorber of any of EEEs 5-6, wherein the concentric sets of columns are disposed in a circular array or an elliptical array.

[0148] EEE 8 is the tuned vibration absorber of any of EEEs 1-7, wherein a cross section of a column of the plurality of columns is circular or elliptical.

[0149] EEE 9 is the tuned vibration absorber of any of EEEs 1-8, wherein a cross section of a column of the plurality of columns varies a long a length of the column.

[0150] EEE 10 is the tuned vibration absorber of any of EEEs 1-9, wherein respective first ends of a first subset of columns of the plurality of columns are attached to the inner member, wherein respective first ends of a second subset of columns of the plurality of columns are attached to the mass member such that the flexible structure couples the inner member to the mass member.

[0151] EEE 11 is the tuned vibration absorber of EEE 10, wherein respective second ends of the first subset of columns and the second subset of columns are coupled to a junction plate such that the plurality of columns are configured as guided-end cantilever beams.

[0152] EEE 12 is the tuned vibration absorber of EEE 11, wherein the junction plate is configured as a disk having a plurality of slots formed in a circular array about the disk.

[0153] EEE 13 is the tuned vibration absorber of EEE 12, wherein the inner member is generally cylindrical and comprises a base that extends radially outward, wherein the base is configured as a respective disk having a respective plurality of slots formed in a respective circular array about the respective disk.

[0154] EEE 14 is the tuned vibration absorber of any of EEEs 1-13, wherein the mass member comprises one or more internal cavities formed therein.

[0155] EEE 15 is the tuned vibration absorber of EEE 14, wherein the one or more internal cavities are separated from each other by respective barriers.

[0156] EEE 16 is the tuned vibration absorber of any of EEEs 14-15, wherein the mass member comprises a plurality of particles disposed in the one or more internal cavities.

[0157] EEE 17 is the tuned vibration absorber of EEE 16, wherein a density of the mass member is larger than a respective density of the plurality of particles.

[0158] EEE 18 is the tuned vibration absorber of any of EEEs 16-17, wherein the plurality of particles are fused in a structure of a particular shape.

[0159] EEE 19 is the tuned vibration absorber of EEE 18, wherein the plurality of particles are fused in a sphere or pyramid-type structure.

[0160] EEE 20 is the tuned vibration absorber of any of EEEs 15-19, wherein the one or more internal cavities are formed in a circular array within the mass member.

[0161] EEE 21 is a tuned vibration absorber comprising: a mass member; a base; and a flexible structure that couples the mass member to the base, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the base. The mass member can be the mass member of any of EEEs 1-20. Also, the flexible structure and plurality of columns can be any of the flexible structure and plurality of columns of EEEs 1-20.

[0162] EEE 22 is an isolation system including the tuned vibration absorber of any of EEEs 1-21 coupled or mounted to a vibrating device.

[0163] EEE 23 is a method of using or operating the tuned vibration absorber of any of EEEs 1-21.

[0164] EEE 24 is a method of making the tuned vibration absorber of any of EEEs 1-21 using additive manufacturing techniques.

Claims

CLAIMSWhat is claimed is:

1. A tuned vibration absorber comprising: a mass member; an inner member disposed, at least partially, within the mass member such that an annular space is formed between the mass member and the inner member; and a flexible structure disposed in the annular space, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the inner member.

2. The tuned vibration absorber of claim 1, wherein the mass member is generally cylindrical and hollow, thereby forming a cylindrical central cavity in which the inner member is disposed, at least partially.

3. The tuned vibration absorber of claim 1, wherein the inner member is generally cylindrical and comprises a base extending radially outward, wherein the tuned vibration absorber further comprises: an outer base plate disposed about the base of the inner member.

4. The tuned vibration absorber of claim 3, further comprising: an elastomeric member that is axially interposed between the mass member and the outer base plate.

5. The tuned vibration absorber of claim 1, wherein the plurality of columns of the flexible structure comprises concentric sets of columns disposed in the annular space.

6. The tuned vibration absorber of claim 5, wherein the concentric sets of columns are disposed in a circular array or an elliptical array.

7. The tuned vibration absorber of claim 1, wherein a cross section of a column of the plurality of columns is circular or elliptical.

8. The tuned vibration absorber of claim 1, wherein a cross section of a column of the plurality of columns varies a long a length of the column.

9. The tuned vibration absorber of claim 1, wherein respective first ends of a first subset of columns of the plurality of columns are attached to the inner member, wherein respective first ends of a second subset of columns of the plurality of columns are attached to the mass member such that the flexible structure couples the inner member to the mass member.

10. The tuned vibration absorber of claim 9, wherein respective second ends of the first subset of columns and the second subset of columns are coupled to a junction plate such that the plurality of columns are configured as guided-end cantilever beams.

11. The tuned vibration absorber of claim 10, wherein the junction plate is configured as a disk having a plurality of slots formed in a circular array about the disk.

12. The tuned vibration absorber of claim 11, wherein the inner member is generally cylindrical and comprises a base that extends radially outward, wherein the base is configured as a respective disk having a respective plurality of slots formed in a respective circular array about the respective disk.

13. The tuned vibration absorber of claim 1, wherein the mass member comprises one or more internal cavities formed therein.

14. The tuned vibration absorber of claim 13, wherein the one or more internal cavities are separated from each other by respective barriers.

15. The tuned vibration absorber of claim 13, wherein the mass member comprises a plurality of particles disposed in the one or more internal cavities.

16. The tuned vibration absorber of claim 15, wherein a density of the mass member is larger than a respective density of the plurality of particles.

17. The tuned vibration absorber of claim 15, wherein the plurality of particles are fused in a structure of a particular shape.

18. The tuned vibration absorber of claim 17, wherein the plurality of particles are fused in a sphere or pyramid-type structure.

19. The tuned vibration absorber of claim 14, wherein the one or more internal cavities are formed in a circular array within the mass member.

20. A tuned vibration absorber comprising: a mass member; a base; anda flexible structure that couples the mass member to the base, wherein the flexible structure comprises a plurality of columns configured as cantilever beams operating as spring members that flexibly interconnect the mass member to the base.

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