Vibration isolation device with thermally conductive pneumatic chamber and manufacturing method thereof

Abstract

Embodiments of a vibration isolation assembly configured to reduce transmission of excitation vibrations between a support surface and a payload at an excitation frequency substantially higher than a resonant frequency of the isolator are disclosed. In one embodiment, the vibration isolation assembly includes a housing assembly having a housing body with a pneumatic chamber formed therein, where the housing assembly is supported by the support surface. The pneumatic chamber is configured to receive at least one fluid therein. A mass engaging member configured to support at least a portion of the payload is supported by the pneumatic chamber, and at least one thermally conductive member in thermal communication with the housing body is positioned within the pneumatic chamber. The thermally conductive member is configured to transfer thermal energy from the fluid in the pneumatic chamber to the housing body and into an ambient environment.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application serial number 17 / 721,834, filed on April 15, 2022, entitled "Vibration Isolation Apparatus with Thermally Conductive Pneumatic Chamber, and Method of Manufacture," the contents of which are incorporated herein by reference. Background Art

[0003] Pneumatic vibration isolators are used in a variety of applications to create a vibration-free environment for precision experiments and manufacturing operations in optoelectronics, life sciences, microelectronics, and nanotechnology. In addition to effective vibration isolation characterized by natural frequencies as low as 1 Hz, pneumatic vibration isolators also provide high load capacity that enables isolation of large equipment such as high-power lasers, atomic force microscopes, scanning tunneling microscopes, cryostats, and large optical assemblies. Some vibration isolators contain damping elements (e.g., flow resistance orifices in the pneumatic chamber) configured to provide the energy dissipation necessary to avoid excessive resonant vibrations.

[0004] While these prior art pneumatic vibration isolators have proven useful in the past, a number of disadvantages have been discovered. For example, prior art pneumatic vibration isolators that use flow resistance orifice damping elements do not provide efficient vibration isolation at frequencies substantially above the resonant frequency of the isolator (e.g., 10 Hz to 500 Hz). In view of the foregoing, there continues to be a need for an improved pneumatic vibration isolator that provides efficient isolation at high frequencies while providing acceptable performance at the resonant frequency. Summary of the invention

[0005] The present application discloses a specific example of a vibration isolation assembly, which is configured to reduce the transmission of excited vibrations between a support surface and a payload at an excitation frequency significantly higher than the resonant frequency of the isolator (e.g., in the range of 5 Hz to 500 Hz). In one specific example, the vibration isolation assembly has a resonant frequency of about 1 Hz. In another specific example, the vibration isolation assembly has a resonant frequency between about 1 Hz and 5 Hz. In one specific example, the excited vibration is about five times the vibration having the resonant frequency. In another specific example, the excited vibration is about ten times the vibration having the resonant frequency.

[0006] In one embodiment, the vibration isolation assembly includes a housing assembly having a housing body having a pneumatic chamber formed therein, wherein the housing assembly is supported by a support surface. The pneumatic chamber is configured to receive at least one fluid therein. A mass engagement member configured to support at least a portion of a payload is supported by the pneumatic chamber, and at least one first thermally conductive member in thermal communication with the housing body is positioned within the pneumatic chamber. The first thermally conductive member is configured to transfer thermal energy from the fluid in the pneumatic chamber to the housing body and to the surrounding environment. In some embodiments, the mass engagement member is configured to adjust the vertical position of the payload.

[0007] The first heat-conducting member may be formed of a material selected from a group consisting of aluminum, steel, stainless steel, copper, copper tungsten, brass, bronze, polymers, diamond, composite materials and ceramic materials. In one embodiment, the first heat-conducting member is a honeycomb structure. In another embodiment, the first heat-conducting member includes a heat-conducting body in which a plurality of channels are formed. The channel may have any of a variety of shapes, including square, rectangular, triangular, pentagonal, hexagonal, octagonal, trapezoidal, circular, elliptical or oval shapes. In an alternative embodiment, the first heat-conducting member is formed by a metal mesh. In another embodiment, the first heat-conducting member is formed by a plurality of metal tubes. In yet another embodiment, the first heat-conducting member is a heat sink. In yet another embodiment, the first heat-conducting member is formed by a ceramic material. The pneumatic chamber may be placed in thermal communication with a heat-conducting fluid in contact with the outer surface of the housing body. In one embodiment, the effective load supported by the vibration isolation assembly is an optical table or a portion of an optical table. In another specific example, the vibration isolation assembly may include a second heat-conducting member fixed to the outer surface of the housing body, wherein the second heat-conducting member may be formed of various materials, including aluminum, steel, stainless steel, copper, copper tungsten, brass, bronze, polymers, diamond, composite materials and ceramic materials. Either the first heat-conducting member or the second heat-conducting member may be integrally formed with the housing body of the housing assembly. In another specific example, the first heat-conducting member is a 3D printed structure that is thermally connected to the housing body, which is formed separately from the housing body or integrally formed. The first heat-conducting member may be thermally connected to the mass engagement member and / or the payload or a portion of the payload, and the mass engagement member may be configured to absorb thermal energy from the pneumatic chamber. The thermal energy absorbed by the first heat-conducting member and transmitted to the housing body can be transmitted away from the housing body by radiation, free convection or forced convection. In an alternative specific example, the vibration isolation assembly includes a thermal management system configured to remove thermal energy from the housing body. The thermal management system may include a heat exchanger, such as an air-to-air heat exchanger or a thermoelectric cooler. In another embodiment, the heat exchanger is placed in fluid communication with an auxiliary heat transfer device, such as a refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various embodiments of the improved vibration isolation assembly will be explained in more detail with the aid of the accompanying drawings, in which:

[0009] FIG1 shows a schematic cross-sectional view of a single-chamber pneumatic vibration isolator;

[0010] Figure 2 A diagram showing a mechanical model of the single-chamber pneumatic vibration isolator shown in FIG1 ;

[0011] FIG3 shows a schematic cross-sectional view of a dual-chamber pneumatic vibration isolator;

[0012] Figure 4 A diagram showing a mechanical model of the double-chamber pneumatic vibration isolator shown in FIG3 ;

[0013] Figure 5 A graph showing a typical vibration transmissibility response of the pneumatic vibration isolators shown in FIGS. 1 and 3 ;

[0014] Figure 6 A cross-sectional view showing an alternative embodiment of a pneumatic vibration isolator;

[0015] Figure 7 Compared with the double chamber pneumatic vibration isolator shown in Figure 3, Figure 6 An experimental graph of the vibration transmissibility response of the specific example of the pneumatic vibration isolator shown in FIG.

[0016] Figure 8 A cross-sectional view showing another embodiment of a pneumatic vibration isolator;

[0017] Fig. 9 exhibit Figure 8 A perspective view of the aerodynamic housing and thermally conductive components shown in FIG.

[0018] Fig.10 A detailed plan cross-sectional view showing a specific example of a thermally conductive member;

[0019] Figure 11 to Figure 13 showing plan cross-sectional views of various embodiments of a pneumatic vibration isolator housing having a thermally conductive member; and

[0020] Fig.14 A perspective view showing a specific example of a pneumatic vibration isolator housing body and a heat conductive member. DETAILED DESCRIPTION

[0021] Exemplary embodiments are described herein with reference to the accompanying drawings. Unless otherwise expressly stated, in the drawings, the size, position, etc. of components, features, elements, etc., and any distances therebetween are not necessarily drawn to scale and may be exaggerated for clarity. In the drawings, the same number always refers to the same element. Therefore, the same or similar number may be described with reference to other drawings, even if it is neither mentioned nor described in the corresponding drawings. In addition, elements that are not even represented by reference numbers may be described with reference to other drawings.

[0022] The terms used herein are only for the purpose of describing specific illustrative specific examples, and are not intended to be restrictive. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those of ordinary skill in the art are generally understood. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural form as well. In addition, depending on the context, the terms "at least one", "at least one" and "one or more" may be intended to include both the singular and plural forms. It should be recognized that the terms "comprises" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or components when used in this specification, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. Unless otherwise indicated, terms such as "first", "second" and the like are only used to distinguish one element from another element. For example, one coupler may be referred to as a "first coupler," and similarly, another coupler may be referred to as a "second coupler," or vice versa.

[0023] Unless otherwise indicated, for ease of description, spatially relative terms such as "below," "beneath," "lower," "above," and "upper," "opposing," etc. may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the drawings. It should be recognized that spatially relative terms are intended to encompass different orientations other than the orientation depicted in the drawings. For example, if the object in the drawings is flipped, an element described as "below" or "under" other elements or features will be oriented "above" the other elements or features. Thus, the exemplary term "below" may encompass both above and below orientations. The object may be otherwise oriented (e.g., rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may be interpreted accordingly. A set of reference axes (e.g., X, Y, Z), directions or coordinates, and rotations about them (e.g., θX, θY, θZ) may be included in the drawings to facilitate orientation of the reader to facilitate understanding of the drawings and description, and does not necessarily indicate that any particular feature or element is aligned or orthogonal to any other feature or element.

[0024] The paragraph numbers used herein are for organizational purposes only and, unless otherwise expressly stated, should not be construed as limiting the subject matter described. It should be understood that many different forms, specific examples, and combinations are possible without departing from the spirit and teachings of the present disclosure, and therefore the present disclosure should not be construed as limited to the exemplary specific examples set forth herein. Instead, these examples and specific examples are provided so that the present disclosure will be thorough and complete, and will convey the scope of the present disclosure to those skilled in the art.

[0025] Specific examples disclosed herein generally relate to vibration isolation assemblies (also referred to herein as "pneumatic vibration isolators," "vibration isolators," or "isolators"). One particular application of vibration isolation assemblies is in optical bench systems. A typical optical bench system includes an optical bench top and one or more vibration isolation assemblies (e.g., four) operable to support the optical bench top. The optical bench top is typically constructed of an upper plate and a lower plate with a honeycomb core positioned between the plates, thereby providing a rigid structure that is low in weight relative to its size and stiffness. Optical bench systems are used for experiments involving lasers, optical components (e.g., lenses, mirrors, prisms), optical measurement instruments (e.g., optical detectors, power meters, cameras), and other equipment. Such experiments are particularly sensitive to vibration, and the vibration isolation assemblies described herein are used to prevent vibrations of the base plate (also referred to herein as "input vibrations" or "excitation vibrations") (e.g., due to human footsteps, movement of building hoists, passing vehicles, and rotating machinery such as electric motors) from reaching equipment mounted on the optical bench top. In addition, the vibration isolation assemblies described herein are also used to prevent or reduce vibrations from the optical table to the base plate or other supporting surface (e.g., another optical table). Depending on the source, the excited vibration occurs at various frequencies or frequency ranges, which are usually measured in Hertz (Hz). The term "transmissibility" as used herein is defined as the amount of excited vibration transmitted from one mass to another mass (e.g., from the base plate to the optical table, or vice versa).

[0026] FIG. 1 shows a schematic cross-sectional view of a vibration isolation assembly 10. The vibration isolation assembly 10 includes a housing 14 defining a single pneumatic chamber 16 having a volume V in pneumatic communication with a pressure source (not shown). The chamber 16 is sealed by a diaphragm 12 that engages and supports a mass engagement member 22 configured to support a payload 24 having a mass m1. The vibration isolation assembly 10 is supported by a support surface 20. During operation, the pneumatic chamber 16 acts as a spring to prevent the transfer of vibrations between the support surface 20 and the payload 24. The vibration isolation assembly 10 is also referred to herein as a "single chamber isolator 10".

[0027] Figure 2 A mechanical model of a single chamber isolator 10 is shown, wherein the effective load 24 has a mass m1, wherein the combined stiffness of the pneumatic chamber and the diaphragm is denoted as K1. Referring back to FIG1, a known disadvantage of the design of the single chamber isolator 10 is that some vibration excitations of the support surface 20 or transient excitations of the support surface 20 may cause the effective load 24 to excessively resonate at the resonant frequency of the oscillator defined by the stiffness K1 and the mass m1.

[0028] 3 shows a schematic cross-sectional view of a vibration isolation assembly 30 (also referred to herein as a "dual chamber isolator 30") that includes a vibration damping feature provided as a flow resistance orifice 46 that is configured to provide pneumatic communication between two pneumatic chambers. The vibration isolation assembly 30 includes a housing 34 and a diaphragm 44, thereby defining a first pneumatic chamber 36 (also referred to as a "compliance chamber") having a volume V1 and a second pneumatic chamber 38 (also referred to as a "damping chamber") having a volume V2. The first pneumatic chamber 36 and the second pneumatic chamber 38 are pneumatically connected to each other via a flow resistance orifice 46 that is designed to provide a viscous gas flow between the chambers 36 and 38. The first chamber 36 is sealed by a diaphragm 32 that supports a mass engaging member 48 (e.g., a piston) that is configured to support a payload 50 (e.g., an optical table or a portion of an optical table) having a mass m1. The vibration isolation assembly 30 is supported by a support surface 42 (e.g., a base plate). During operation, pneumatic chambers 36 and 38 act as springs to prevent excitation vibrations from being transferred between payload 50 and support surface 42, effectively isolating the payload from excitation vibrations from support surface 42. Flow resistance orifices 46 provide energy dissipation to prevent or reduce excessive resonant vibrations.

[0029] Figure 4 A mechanical model of a dual chamber isolator 30 with a payload 50 of mass m1 is shown. Here, K2 represents the stiffness of the upper chamber 36, K3 represents the stiffness of the lower chamber 38, and C 12 represents the viscosity of the gas moving through the orifice 46, and K d represents the stiffness of the diaphragm 32. The dynamic stiffness of the dual-chamber pneumatic isolator 30 has two extreme values. At a low excitation frequency (f→0), the gas flow resistance through the flow resistance orifice 46 is low, and the dynamic stiffness K(f) of the dual-chamber isolator 30 presents a minimum value K L , which corresponds to the first chamber 36 and the second chamber 38 acting as a single chamber. At a higher excitation frequency, the gas flow resistance through the flow resistance orifice 46 increases, and the dynamic stiffness K(f) of the dual-chamber isolator 30 approaches the maximum limit value K H , which corresponds to the first chamber 36 acting alone. Thus, at lower excitation frequencies, the dual-chamber isolator acts as a more effective large-volume isolator (e.g., volume equal to V1+V2) with a low natural frequency, while at higher excitation frequencies, the dual-chamber isolator acts as a less effective small-volume isolator (e.g., volume equal to V1) with a higher natural frequency.

[0030] Figure 5 A graph showing the vibration transmissibility between the support surface and the effective load as a function of the frequency (f) of the exciting vibration at constant mass = rm is shown, and depicts the tradeoff between resonant vibration damping and vibration isolation performance at higher frequencies. Figure 5 The transmissibility curve of the vibration isolation assembly 10 with effective load rm (shown by the dashed line) and the transmissibility curve of the vibration isolation assembly 30 with the same effective load rm and the same total air volume (shown by the solid line) are shown. At the excitation frequency f = 50 Hz, the transmissibility of the single-chamber isolator 10 is about 3×10 -3 , and the transmission rate of the double-chamber isolator 30 is about 3×10 -2 This gives the transmissibility difference ΔT on a logarithmic scale between vibration isolators 10 and 30 50 =10, the difference is an order of magnitude (10 times) difference.

[0031] At the resonant frequency of f = 1 Hz, the transmissibility of the single chamber isolator 10 is about 20, and the transmissibility of the dual chamber isolator 30 is about 5. This gives a transmissibility difference of ΔT1 = 4 at 1 Hz. This represents a 4-fold difference between the transmissibility of the single chamber isolator 10 and the dual chamber isolator 30. In most applications, this high transmissibility at the resonant frequency is unacceptable, so the dual chamber isolator design is favored because it provides damping, while the single chamber isolator design does not, and the better isolation performance of the single chamber isolator 10 at higher frequencies is not worth the trade-off of poor isolation performance at resonance. It is important to note that Figure 5 The transmissibility curves shown in are typical of single and dual compartment isolator designs. The exact transmissibility curves and frequency responses of single and dual compartment isolator designs may vary depending on the mass of the payload and various other conditions.

[0032] Figure 6 A schematic cross-sectional view of a specific example of a vibration isolation assembly 100 is shown, the vibration isolation assembly being configured to prevent or reduce the transfer of excitation vibrations between a support surface and a payload at high vibration excitation frequencies while providing improved performance at low frequencies compared to the performance of the vibration isolation assembly 10. In this specific example, the vibration isolation assembly 100 includes a housing assembly 300 having a housing body 302 having a pneumatic chamber 310 having a volume V in pneumatic communication with a pressure source (not shown) formed therein. h .although Figure 6The specific example shown in includes a single pneumatic chamber formed within the housing body 302, but those skilled in the art will appreciate that any number of pneumatic chambers of any variety of sizes, shapes, and / or lateral dimensions may be formed within the housing body 302. The pneumatic chamber 310 is sealed by a diaphragm 330 that engages and supports a mass engaging member 400 (e.g., a piston) that is movably coupled to the housing body 302 and configured to support and adjust the vertical position of a payload 500 (e.g., an optical bench or a portion of an optical bench) having a mass m. The housing body 302 and the mass engaging member 400 may be formed of a variety of materials, including, but not limited to, aluminum, steel, stainless steel, copper, brass, bronze, polymers, composite materials, and ceramic materials. In one specific example, the mass m is approximately 500 kilograms, but those skilled in the art will appreciate that the vibration isolation assembly 100 may be configured to support payloads having a wide variety of masses. In this specific example, the pneumatic chamber 310 is configured to contain a thermally conductive compressible fluid 320 at a pressure selected to support the mass engaging member 400 and the payload 500. In this specific example, the fluid 320 is air, but those skilled in the art will understand that any compressible fluid (e.g., an inert gas such as argon, helium, nitrogen, etc.) may be used. In another specific example, the fluid 320 may include a liquid. Thus, the pneumatic chamber 302 may alternatively include a hydraulic chamber. In another specific example, the fluid 320 may include both a gas and a liquid. Thus, in another specific example, the pneumatic chamber 320 may form a fluid chamber configured to support the mass engaging member 400 that is movably coupled to the housing body 302. The vibration isolation assembly 100 is supported by a support surface 200 (e.g., a base plate or other structure). The vibration isolation assembly 100 further includes at least one thermally conductive member 340 positioned in the pneumatic chamber 310, in thermal communication with the housing body 302, and configured to absorb thermal energy generated in the pneumatic chamber 310 by the compression of the fluid 320 and transfer the thermal energy to the housing body 302, wherein the thermal energy is transferred to the surrounding environment. The thermal energy can be transferred away from the housing body 302 and can be transferred to the surrounding environment by radiation, free convection, or forced convection (e.g., a fan directed toward the housing body 302). Generally, the thermally conductive member 340 is configured to place the thermally conductive material in close contact with as much of the fluid 320 as possible. In this specific example, the thermally conductive member 340 occupies a volume V h About 90% of the volume, and the remaining volume Figure 6 340. The vibration isolation assembly 100 having the thermally conductive member 340 may also be referred to herein as a "thermally conductive isolator 100." In some specific examples, the mass engaging member 400 may be positioned in thermal communication with the payload 500 so that the mass engaging member 400 may absorb thermal energy from the pneumatic chamber 310 and transfer it to the payload 500 and / or the surrounding environment.

[0033] The heat conducting member 340 is configured to absorb heat generated when the fluid 320 is dynamically compressed during a vibration change in the volume of the air when the mass engaging member 400 moves vertically while supporting the payload 500. h Since air or other gases that can be used as fluid 320 are poor thermal conductors, the thermally conductive member 340 is configured to place a thermally conductive material (e.g., a metal such as aluminum) as close as possible to as much of the fluid volume as possible, thereby effectively increasing the thermal conductivity of the air in the pneumatic chamber 310. To this end, the thermally conductive member 340 is generally provided as a porous thermally conductive structure that distributes heat in the volume V of the pneumatic chamber 310. h The heat energy generated in the heat transfer to the housing body 302, thereby transferring the heat energy to the surrounding environment. The heat conductive member 340 can be provided as a heat conductive body having a plurality of channels formed therein. In this specific example, the heat conductive member 340 is provided as a honeycomb structure (e.g., Fig.10 ), which has hexagonal passages oriented parallel to the vertical motion of the mass engaging member 400. Although most honeycomb structures have cells with hexagonal shapes or geometries, the term "honeycomb" used in describing specific examples herein should not be interpreted as limited to hexagonal shapes or geometries, and thus may also have other shapes or geometries. The honeycomb structure may be formed of any of a variety of materials, including but not limited to aluminum, steel, stainless steel, copper, copper tungsten, brass, bronze, polymers, composite materials, ceramic materials, and nanostructured materials (e.g., carbon nanotubes).

[0034] Fig.10 A close-up plan cross-section of a specific example of a honeycomb structure for forming a thermally conductive member 340 positioned in a housing body 302 is shown. The honeycomb structure includes a plurality of cells 344 extending vertically through a pneumatic chamber 310. Each cell 344 defines a pneumatic volume 348 and shares at least one thermally conductive cell wall 346 with at least one adjacent cell, such that thermal energy can be conducted along the wall of each cell to the wall of an adjacent cell and ultimately to the housing body 302, where the thermal energy is radiated, conducted, or convected into the surrounding environment. In this specific example, each cell 344 has a width H, but in some specific examples, individual cells may have different widths. When so configured, each fluid molecule in each pneumatic volume 348 is positioned no more than a distance H / 2 away from the thermally conductive cell wall 346, thereby effectively increasing Figure 63. The thermal conductivity of the gas within the pneumatic chamber 310 shown in FIG. 3. In this embodiment, the width of the cell is 6 mm, which means that all fluid molecules within the honeycomb structure are no closer than about 3 mm to the thermally conductive material forming the cell wall 346. In the illustrated embodiment, each cell 344 has the same width, but in other embodiments, the cells 344 may have different widths.

[0035] In a specific example, Fig. 9 , the thermally conductive member 340 is placed in direct contact with the housing body 302 by pressing the honeycomb structure into the housing body 302, so that some of the outer honeycomb cells 344 are deformed at the connection between the housing body 302 and the thermally conductive member 340, thereby providing sufficient thermal contact between the thermally conductive member 340 and the housing body 302. In another embodiment, the thermally conductive member 340 is bonded to the housing body 302 by a thermally conductive adhesive (not shown). In another embodiment, air or another fluid can be forced (e.g., by a fan) through the aerodynamic volume 348 of each cell 344 so as to convect thermal energy away from each cell 344 to the housing body 302. In another embodiment, air or another fluid can be drawn (e.g., by a fan or vacuum pump) through the aerodynamic volume 348 of each cell 344 so as to advect thermal energy away from each cell 344 to the housing body 302. In another embodiment, the fluid 320 can be circulated through different cells 344 by a variety of different devices or methods. In this specific example (ref. Figure 6 ), the combined volume of the air in the honeycomb unit is the total volume V of the pneumatic chamber 310 h The volume 350 above the heat conducting member 340 is approximately 90%, while the remaining volume 350 above the heat conducting member 340 provides sufficient space to allow the mass engaging member 400 to move vertically during operation. The respective percentages of the air volume in the honeycomb unit 344 and the remaining volume 350 can be customized to provide optimal insulation performance for various applications. For example, in one specific example, for a vibration environment where the excitation frequency is expected to be in the range of 40 Hz to 55 Hz, this ratio can be 90% / 10%. In another specific example, for a vibration environment where the excitation frequency is expected to be in the range of 56 Hz to 70 Hz, this ratio can be 80% / 20%.

[0036] In alternative embodiments, such as Fig.10, one or more thermal conductors (e.g., hexagonal conductors 600) may be placed within one or more of the honeycomb cells 344. In another specific example, one or more thermal conductors 650 having a circular cross-section may be inserted into the thermally conductive member 340 to increase the rate of heat transfer from the thermally conductive member 340 to the housing body 302. In one specific example, the thermal conductors 600, 650 may be provided as solid metal (e.g., copper) rods. In another specific example, the conductors 600, 650 may be provided as heat pipes. It will be appreciated by those skilled in the art that any type or number of thermal conductors may be placed in the thermally conductive member 340.

[0037] Although Fig.10 The cells 344 in the illustrated embodiment shown in are hexagonal, but in other embodiments, the cells 344 may have a square, rectangular, triangular, pentagonal, octagonal, trapezoidal, circular, oval, or elliptical shape. In other embodiments, the cells 344 may be star-shaped or randomly shaped. It will be appreciated by those skilled in the art that the cells 344 may be formed into a variety of shapes configured to maximize or customize heat transfer from the fluid 320 within the pneumatic chamber 310 to the housing 304 and to the surrounding environment. Although the possible shapes listed above may represent precise geometric shapes, it will be appreciated by those skilled in the art that manufacturing methods may produce shapes that approximate the shapes listed above without departing from the spirit and teachings of the present disclosure.

[0038] Return to reference Figure 6 , the thermally conductive member 340 can be formed of a wide variety of materials having different thermal conductivities and different mechanical configurations. Exemplary materials of the thermally conductive member 340 include, but are not limited to, aluminum, steel, stainless steel, copper, copper tungsten, brass, bronze, polymers, diamond, composite materials, ceramic materials, and nanostructured materials (e.g., carbon nanotubes). Thermal conductivity is measured in units of watts per meter-Kelvin (W / mK). The thermal conductivity of air is approximately 0.026 W / mK. The thermal conductivity of aluminum is between 237 W / mK and 247 W / mK, which is approximately 9,000 times the thermal conductivity of air. The thermal conductivity of copper is 398 / 390 W / mK. The thermal conductivity of tungsten is approximately 173 W / mK. In addition, the thermally conductive member 340 can be formed of a wide variety of materials having different specific heat capacities, which are measured in units of joules per kilogram-Kelvin (J / kg-K). For example, in one embodiment, the thermally conductive member 340 may be made of aluminum having a specific heat capacity of about 920 J / kg-K. In another embodiment, the thermally conductive member 340 may be made of copper having a specific heat capacity of about 377 J / kg-K. It will be appreciated by those skilled in the art that the thermally conductive member 340 may be made of materials having any of a variety of specific heat capacities.

[0039] Return to reference Figure 6In some embodiments, in order to maximize the transfer of heat energy from the housing body 302 to the surrounding environment, one or more additional heat-conducting members or devices 360 may be placed in thermal contact with the outer surface of the housing body 302. In one embodiment, the heat-conducting device 360 ​​is provided as a heat sink attached to the outer surface of the housing body 302. The heat sink 360 may include a plurality of cooling fins (not shown). Exemplary materials of the heat sink 360 include metals with high thermal conductivity (e.g., aluminum, copper, bronze, copper tungsten, magnesium, etc. or any combination thereof) or metals with a combination of high heat capacity and high thermal conductivity, such as copper or copper tungsten. In one embodiment, the heat sink 360 is a single passive device, thereby transferring heat energy to the surrounding environment by radiation or free convection. In another embodiment, the heat sink 360 may include one or more fans, which are operable to guide air flow through the heat sink 360 to transfer heat energy to the surrounding environment by forced convection. In another embodiment, the heat sink 360 may include one or more thermoelectric coolers. In yet another specific example, a thermally conductive member may be placed between the housing body 302 and the support surface 200 so that thermal energy from the housing body 302 may be conducted to the support surface 200 and to the surrounding environment. Those skilled in the art will appreciate that any type or number of heat sinks or other heat transfer devices may be placed in thermal communication with the housing body 302 and the surrounding environment.

[0040] Figure 7 An experimental graph showing the vibration transmissibility between the support surface and the effective load as a function of the frequency of the exciting vibration is provided to compare the dual chamber isolator 30 with the Figure 6 The transmissibility of at least one embodiment of the thermally conductive isolator 100 described above is compared. Both isolators have the same total air volume and support the same load. Starting at an excitation frequency of about 4 Hz, the transmissibility of the vibration isolation assembly 100 is less than the transmissibility of the dual chamber isolator 30. At about 50 Hz, the transmissibility of the vibration isolation assembly 100 is about 2×10 -4 , and the transmission rate of the vibration isolation assembly 30 is about 2×10 -3 This is the transmissibility difference ΔT on a logarithmic scale at 50 Hz 50 =10, the difference is an order of magnitude (10 times) difference.

[0041] At a resonant frequency of about 1 Hz, the thermally conductive isolator 100 has a transmissivity of about 4, and the dual chamber isolator 30 has a transmissivity of about 3. This gives a transmissivity difference of ΔT1 = 1.33 at 1 Hz, which means that the transmissivity of the thermally conductive isolator 100 at resonance is about 1.33 times that of the dual chamber isolator 30. In many applications, this tradeoff is acceptable because the transmissivity of the thermally conductive isolator 100 at resonance is only slightly greater than that of the dual chamber isolator, but the transmissivity at 50 Hz is 10 times that of the dual chamber isolator.

[0042] Figure 7 The transmissibility curve of the thermally conductive insulator 100 shown in is only illustrative of one specific example of the thermally conductive insulator 100. The thermally conductive insulator 100 may have any of a variety of transmissibility curves or frequency / insulation responses to the excitation vibration, depending on a wide variety of factors, including the mass of the effective load, the exact design of the thermally conductive insulator 100, and on a variety of other conditions. For example, in some specific examples, the thermally conductive insulator 100 may have a resonant frequency between 1 Hz and 50 Hz, or may experience resonance at an excitation frequency between 1 Hz and 50 Hz. In some specific examples, the excitation vibration may be a multiple of the resonant frequency. For example, in one specific example, the excitation vibration may be between 5 and 10 times the resonant frequency, but those skilled in the art will appreciate that the excitation vibration may be any multiple of the resonant frequency. In one specific example, the thermally conductive insulator 100 may be configured to provide a lower transmissibility (e.g., relative to a dual chamber insulator) at an excitation vibration frequency in the range of 2 Hz to 20 Hz. In another embodiment, the thermally conductive isolator 100 can be configured to provide a lower transmissivity at an excitation vibration frequency in a range of 5 Hz to 50 Hz. In other embodiments, the thermally conductive isolator 100 can be configured to provide a lower transmissivity at an excitation vibration frequency in a range of 50 Hz to 500 Hz. It will be appreciated by those skilled in the art that the thermally conductive isolator 100 can provide improved insulation performance relative to a dual chamber isolator at any excitation vibration frequency, frequency range, or frequency band.

[0043] Figure 8 A schematic cross-sectional view of an embodiment of a thermally conductive pneumatic isolator 100 is shown having an active heat transfer system, such as a thermal management system 1000, placed in thermal communication with a thermally conductive member 340. In this embodiment, the vibration isolation assembly 100 has a thermally conductive member 340 having an active heat transfer system, such as a thermal management system 1000, placed in thermal communication with a thermally conductive member 340. Figure 6 The configuration described is substantially the same configuration, wherein the housing assembly 300 has a housing body 302 that defines a volume V h310 filled with a compressible fluid 320 at a pressure selected to support a payload 500. The housing assembly 300 rests on a support surface 200 and has a mass engagement member 400 that supports a payload 500 having a mass m (e.g., an optical bench or a portion of an optical bench). In this specific example, the thermal management system 1000 includes a heat transfer device 1002 extending into the pneumatic chamber 310 and the thermally conductive member 340. In this specific example, the heat transfer device 1002 does not prevent the fluid 320 from flowing from an area above the heat transfer device 1002 to an area below the heat transfer device 1002. Exemplary heat transfer devices 1002 include, but are not limited to, air-to-air heat exchangers, air-to-water heat exchangers, heat pipes, heat pumps, forced air convection systems, thermoelectric coolers, the like, or any combination thereof. In this particular example, the heat transport device 1002 is in fluid and thermal communication with an auxiliary heat transport device 1006 (eg, a cooler) via a conduit, tube, or pipe 1004 .

[0044] Figures 9 to 13 Various specific examples of thermally conductive components that may be placed in the housing body 302 of the thermally conductive isolator 100 are shown. Fig. 9 A specific example of a housing body 302 is shown in which a thermally conductive member 340 is provided as a honeycomb structure. In this specific example, the housing body 302 includes a plurality of extended regions 304 formed in the housing body 302, wherein each extended region 304 has a fastener passage 306 formed therein, wherein the fastener passage 306 is configured to receive a fastener (not shown) for securing the housing body 302 to other components of the vibration isolation assembly 100. A plurality of protrusions 342 are formed in the thermally conductive member 340, wherein each protrusion 342 corresponds to an extended region 304 of the housing body 302, so as to maximize physical and thermal contact between the thermally conductive member 340 and the inner surface of the housing body 302.

[0045] Fig.10 A close-up plan cross-section showing a specific example of a honeycomb structure used to form a thermally conductive member 340 positioned in the housing body 302. Figure 6 Describe in more detail Fig.10 . The honeycomb structure includes a plurality of cells 344 extending vertically through the pneumatic chamber 310. Each cell 344 defines a pneumatic volume 348 and shares at least one thermally conductive cell wall 346 with at least one adjacent cell, so that thermal energy can be conducted along the wall of each cell to the wall of an adjacent cell and ultimately to the housing body 302, where the thermal energy is radiated, conducted, or convected to the surrounding environment. In this embodiment, each cell 344 has a width H, but in some embodiments, individual cells may have different widths.

[0046] Fig.11 A plan cross-sectional view of the housing body 302 is shown, the housing body having a heat conductive member 700 disposed therein. In one specific example, the heat conductive member 700 is formed of a steel mesh or steel wool configured to absorb thermal energy within the pneumatic chamber 310 and conduct the thermal energy to the housing body 302. In another specific example, the heat conductive member 700 may be formed of a plurality of square tubes or other square members having air volumes formed therein, wherein the tubes or square members are configured to absorb thermal energy within the pneumatic chamber 310 and conduct the thermal energy to the housing body 302. In another specific example, the heat conductive member 700 may be formed of a porous metal foam or other porous foam formed of a thermally conductive material, the porous metal foam or other porous foam allowing the fluid 320 to circulate between its cells so that the thermal energy generated in the pneumatic chamber 310 is conducted to the housing body 302.

[0047] Fig.12 A plan cross-sectional view of the housing body 302 is shown having a thermally conductive member 800 disposed therein. In one specific example, the thermally conductive member 800 is formed of a plurality of thermally conductive plates (e.g., formed of aluminum or other thermally conductive materials) configured to absorb thermal energy within the pneumatic chamber 310 and conduct the thermal energy to the housing body 302. In another specific example, the thermally conductive member 800 may be formed of a plurality of heat sinks positioned in the housing body 302 and configured to absorb thermal energy within the pneumatic chamber 310 and conduct the thermal energy to the housing body 302.

[0048] Fig.13 A plan cross-sectional view of the housing body 302 is shown having a thermally conductive member 900 disposed therein. In one specific example, the thermally conductive member 900 is formed by a plurality of circular tubes or ducts disposed in thermal communication with one another, each tube or duct having an air volume formed therein, wherein the circular tubes or ducts are configured to absorb thermal energy within the pneumatic chamber 310 and conduct the thermal energy to the housing body 302.

[0049] Fig.14A specific example of a housing 380 that can be used in a thermally conductive isolator 100 is shown. In this specific example, the housing 380 includes a housing body 382 having a thermally conductive member 390 disposed therein. In this specific example, the housing body 382 includes a plurality of extension regions 386 formed in the housing body 382, ​​wherein each extension region 386 has a fastener passage 388 formed therein, wherein the fastener passage 388 is configured to receive a fastener (not shown) for securing the housing body 382 to other components of the thermally conductive isolator 100. A plurality of heat transfer members 384 (e.g., cooling fins) are formed on at least one interior surface of the housing body 382, ​​wherein the heat transfer members 384 are configured to conduct thermal energy from the thermally conductive member 390 (and elsewhere in the pneumatic chamber 310 of the vibration isolation assembly 100) to the exterior of the housing body 382, ​​wherein the thermal energy is dissipated to the surrounding environment. The thermally conductive member 390 may be formed of any of the materials or configurations described above with respect to the thermally conductive member 340. In alternative embodiments, the heat transfer members 384 may extend further into the housing body 382 and may be configured such that the heat transfer members collectively provide sufficient thermal conductivity to the air in the pneumatic chamber 310 such that a separate thermally conductive member 390 is not required. Thus, the plurality of heat transfer members 384 may effectively form a thermally conductive member integrally formed with the housing body 382. In other embodiments, the thermally conductive member 390 may be provided as a 3D printed structure that is formed separately from or integrally formed with the housing body 382.

[0050] The foregoing describes the specific examples and paradigms of the present invention and should not be construed as limiting them. Although several specific specific examples and paradigms have been described with reference to the drawings, it will be readily understood by those skilled in the art that many modifications may be made to the disclosed specific examples and paradigms and other specific examples without substantially departing from the novel teachings and advantages of the present invention. Therefore, all such modifications to the subject matter described herein are intended to be included within the scope of the present invention as defined in the claims. For example, it will be understood by those skilled in the art that the subject matter of any sentence, paragraph, example or specific example may be combined with some or all of the subject matter in other sentences, paragraphs, examples or specific examples, unless such combinations are mutually exclusive. Therefore, the scope of the present invention should be determined by the appended claims, wherein the equivalents of the claims are included therein.

Claims

1. A vibration isolation assembly configured to reduce the transmission of at least one excitation vibration between at least one support surface and at least one payload, comprising: at least one housing assembly having at least one housing body having at least one pneumatic chamber formed therein, the at least one pneumatic chamber configured to receive at least one fluid, wherein the at least one housing assembly is supported by the at least one support surface; at least one mass engaging member supported by the at least one pneumatic chamber, the at least one mass engaging member configured to support at least a portion of the at least one payload; at least one first thermally conductive member positioned within the at least one pneumatic chamber, the at least one first thermally conductive member being in thermal communication with the at least one housing body; Wherein the at least one first thermally conductive member is configured to transfer thermal energy from the at least one fluid in the at least one pneumatic chamber to the at least one housing body. 2 . The vibration isolation assembly according to claim 1 , wherein the at least one first thermally conductive member is at least one honeycomb structure.

3. A vibration isolation assembly according to claim 2, wherein the at least one honeycomb structure is metallic. 4 . The vibration isolation assembly of claim 1 , wherein the at least one first thermally conductive member comprises at least one thermally conductive body having a plurality of channels formed therein.

5. The vibration isolation assembly of claim 4, wherein the channel formed in the at least one first thermally conductive member has a shape selected from the group consisting of square, rectangle, triangle, pentagon, hexagon, octagon, trapezoid, circle, ellipse, oval. The vibration isolation assembly of claim 1 , wherein the at least one first thermally conductive member is formed of at least one metal mesh. 7 . The vibration isolation assembly of claim 1 , wherein the at least one first thermally conductive member is formed of a plurality of metal tubes.

8. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is at least one heat sink.

9. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is formed of at least one ceramic material.

10. The vibration isolation assembly of claim 1, wherein the at least one exciting vibration has a frequency between 5 Hz and 30 Hz.

11. The vibration isolation assembly of claim 1, wherein the at least one exciting vibration has a frequency between 30 Hz and 70 Hz.

12. The vibration isolation assembly of claim 1, wherein the at least one exciting vibration has a frequency between 70 Hz and 150 Hz.

13. The vibration isolation assembly of claim 1, wherein the at least one exciting vibration has a frequency between 100 Hz and 200 Hz.

14. The vibration isolation assembly of claim 1, wherein the at least one exciting vibration has a frequency between 100 Hz and 500 Hz.

15. The vibration isolation assembly of claim 1, wherein the vibration isolation assembly has a resonant frequency between approximately 1 Hz and 5 Hz.

16. The vibration isolation assembly of claim 15, wherein the at least one exciting vibration is about five times the vibration having the resonant frequency.

17. The vibration isolation assembly of claim 15, wherein the at least one exciting vibration is about ten times greater than a vibration having a resonant frequency.

18. The vibration isolation assembly of claim 1, wherein the at least one payload is at least one optical table.

19. The vibration isolation assembly of claim 1, further comprising at least one second thermally conductive member secured to at least one exterior surface of the housing body.

20. The vibration isolation assembly of claim 19, wherein the at least one second thermally conductive member is at least one heat sink.

21. The vibration isolation assembly of claim 1, wherein at least one of the at least one housing body and the at least one mass engaging member is formed of a material selected from the group consisting of aluminum, steel, stainless steel, copper, brass, bronze, polymers, composites, and ceramic materials.

22. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is formed of a material selected from the group consisting of aluminum, steel, stainless steel, copper, copper tungsten, brass, bronze, polymers, diamond, composites, and ceramic materials.

23. The vibration isolation assembly of claim 1, wherein the at least one pneumatic chamber is placed in thermal communication with at least one thermally conductive fluid in contact with at least one exterior surface of the at least one housing body.

24. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is at least one 3D printed structure in thermal communication with the at least one housing body.

25. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is integrally formed with the at least one housing body.

26. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is at least one 3D printed structure integrally formed with the at least one housing body.

27. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is in thermal communication with the at least one mass engaging member.

28. The vibration isolation assembly of claim 1, wherein the at least one first thermally conductive member is in thermal communication with the at least one payload.

29. The vibration isolation assembly of claim 1, wherein the thermal energy is transferred away from the at least one housing body by forced convection.

30. The vibration isolation assembly of claim 1, wherein the thermal energy is transferred away from the at least one housing body by free convection.

31. The vibration isolation assembly of claim 1, wherein the thermal energy is transferred away from the at least one housing body by radiation.

32. The vibration isolation assembly of claim 1, further comprising at least one thermal management system configured to remove thermal energy from the at least one housing body.

33. A vibration isolation assembly according to claim 32, wherein the at least one thermal management system comprises at least one heat exchanger.

34. A vibration isolation assembly according to claim 33, wherein the at least one heat exchanger is in fluid communication with at least one auxiliary heat transfer device.

35. A vibration isolation assembly according to claim 33, wherein the at least one heat exchanger is at least one air-to-air heat exchanger.

36. The vibration isolation assembly of claim 33, wherein the at least one heat exchanger comprises at least one thermoelectric cooler.

37. The vibration isolation assembly of claim 1, wherein the at least one mass engaging member is configured to adjust a vertical position of the at least one payload.

38. The vibration isolation assembly of claim 1, wherein the at least one mass engaging member is configured to absorb thermal energy from the at least one pneumatic chamber.

39. A vibration isolation assembly comprising: at least one housing assembly having at least one housing body having at least one fluid chamber formed therein, the at least one fluid chamber being configured to receive at least one fluid therein; at least one mass engaging member movably coupled to the at least one housing body and supported by the at least one fluid chamber, the at least one mass engaging member configured to support at least a portion of at least one payload; At least one first thermally conductive member is positioned within the at least one fluid chamber, the at least one first thermally conductive member being in thermal communication with the at least one housing body and configured to transfer thermal energy from the at least one fluid in the at least one fluid chamber to the at least one housing body.

Images