Vibration isolation device with thermally conductive air chamber and method of manufacture

Abstract

The present application discloses an embodiment of an isolation assembly configured to reduce transmission of excited vibrations between a support surface and a payload at an excitation frequency much higher than a resonant frequency of an isolator. In one embodiment, the isolation assembly includes a housing assembly having a housing body having an air chamber formed therein, the housing assembly supported by the support surface. The air chamber is configured to receive at least one fluid therein. A mass engagement member configured to support at least a portion of the payload is supported by the air chamber, and at least one thermally conductive member in thermal communication with the housing body is disposed within the air chamber. The thermally conductive member is configured to transfer thermal energy from the fluid in the air chamber to the housing body and to a surrounding environment.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. patent application Ser. No. 17 / 721,834, entitled "Vibration Isolation Device with Thermally Conductive Air Chamber and Manufacturing Method," filed April 15, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] background Pneumatic vibration isolators are used in a variety of applications to create vibration-free environments for precision laboratory and manufacturing operations in optoelectronics, life sciences, microelectronics, and nanotechnology. In addition to effective vibration isolation characterized by a natural frequency of only 1 Hz, pneumatic vibration isolators offer high load capacities that allow 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 air chamber) that are configured to provide the necessary energy dissipation to avoid excessive resonant vibrations.

[0003] While these prior art pneumatic isolators have been found to be useful in the past, numerous shortcomings have been identified. For example, prior art pneumatic isolators that utilize flow resistive orifice damping elements do not provide highly effective isolation at frequencies substantially higher than the resonant frequency of the isolator (e.g., 10-500 Hz). In view of the above, there continues to be a need for improved pneumatic isolators that provide highly effective isolation at high frequencies while still providing acceptable performance at resonant frequencies. Summary of the Invention

[0004] overview The present application discloses embodiments of an isolation assembly configured to reduce transmission of excitation vibrations between a support surface and a payload at an excitation frequency much higher than the resonant frequency of the isolator (e.g., in the range of 5 Hz to 500 Hz). In one embodiment, the isolation assembly has a resonant frequency of about 1 Hz. In another embodiment, the isolation assembly has a resonant frequency in the range of about 1 Hz to 5 Hz. In one embodiment, the excitation vibration is about 5 times the resonant frequency vibration. In another embodiment, the excitation vibration is about 10 times the resonant frequency vibration.

[0005] In one embodiment, the vibration isolation assembly includes a housing assembly having a housing body with an air chamber formed therein, the housing assembly supported by a support surface. The air 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 air chamber, and at least one first thermally conductive member in thermal communication with the housing body is disposed within the air chamber. The first thermally conductive member is configured to transfer thermal energy from the fluid in the air chamber to the housing body and to the surrounding environment. In some embodiments, the mass engagement member is configured to adjust a vertical position of the payload.

[0006] The first thermally conductive member may be formed from a material selected from the group consisting of aluminum, steel, stainless steel, copper, copper-tungsten, brass, bronze, polymer, diamond, composite material, and ceramic material. In one embodiment, the first thermally conductive member is a honeycomb structure. In another embodiment, the first thermally conductive member includes a thermally conductive body having a plurality of channels formed therein. The channels may have any of a variety of shapes, including square, rectangular, triangular, pentagonal, hexagonal, octagonal, trapezoidal, circular, elliptical, or oval. In another embodiment, the first thermally conductive member is formed from a metal mesh. In another embodiment, the first thermally conductive member is formed from a plurality of metal tubes. In yet another embodiment, the first thermally conductive member is a heat sink. In yet another embodiment, the first thermally conductive member is formed from a ceramic material. The air chamber may be disposed in thermal communication with a thermally conductive fluid in contact with the exterior surface of the housing body. In one embodiment, the payload supported by the vibration isolation assembly is an optical tabletop or a portion of an optical tabletop. In another embodiment, the vibration isolation assembly may further include a second thermally conductive member secured to an outer surface of the housing body. The second thermally conductive member may be formed from a variety of materials, including aluminum, steel, stainless steel, copper, copper-tungsten, brass, bronze, polymer, diamond, composite materials, and ceramic materials. Either the first thermally conductive member or the second thermally conductive member may be monolithically formed with the housing body of the housing assembly. In another embodiment, the first thermally conductive member is a 3D printed structure in thermal communication with the housing body, formed separately from or monolithically with the housing body. The first thermally conductive member may be in thermal communication with a mass engagement member and / or a payload or a portion of the payload, and the mass engagement member may be configured to absorb thermal energy from the air chamber. Thermal energy absorbed by the first thermally conductive member and transferred to the housing body may be transferred away from the housing body by radiation, free convection, or forced convection.In another embodiment, 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 other embodiments, the heat exchanger is disposed in fluid communication with a secondary heat transfer device, such as a chiller. [Brief description of the drawings]

[0007] BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments of the improved anti-vibration assembly are explained in more detail by the accompanying drawings.

[0008] [Figure 1] FIG. 1 shows a schematic cross-sectional view of a single-chamber pneumatic vibration isolator.

[0009] [Diagram 2] FIG. 2 shows a mechanical model diagram of the single-chamber pneumatic vibration isolator shown in FIG.

[0010] [Diagram 3] FIG. 3 shows a schematic cross-sectional view of a two-chamber pneumatic vibration isolator.

[0011] [Figure 4] FIG. 4 shows a mechanical model diagram of the dual-chamber pneumatic vibration isolator shown in FIG.

[0012] [Diagram 5] FIG. 5 shows a graph of a typical vibration transmissibility response for the pneumatic isolator shown in FIGS.

[0013] [Figure 6] FIG. 6 shows a cross-sectional view of another embodiment of a pneumatic isolator.

[0014] [Figure 7]FIG. 7 shows an experimental graph of vibration transmissibility response for the embodiment of the pneumatic isolator shown in FIG. 6 compared to the dual chamber pneumatic isolator shown in FIG.

[0015] [Figure 8] FIG. 8 shows a cross-sectional view of another embodiment of a pneumatic isolator.

[0016] [Figure 9] FIG. 9 shows a perspective view of the air housing and thermally conductive member shown in FIG.

[0017] [Figure 10] FIG. 10 shows a detailed cross-sectional plan view of an embodiment of a thermally conductive member.

[0018] [Figure 11-13] 11-13 show cross-sectional plan views of various embodiments of pneumatic isolator housings having thermally conductive members.

[0019] [Figure 14] FIG. 14 illustrates a perspective view of an embodiment of a pneumatic isolator housing body and thermally conductive member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Detailed Description Hereinafter, examples of embodiments will be described with reference to the accompanying drawings. Unless explicitly stated, in the drawings, the sizes, positions, etc. of components, features, elements, etc., and the distances therebetween are not necessarily to scale and may be exaggerated for ease of understanding. Like numbers refer to like elements throughout the drawings. Thus, the same or similar numbers may be described with reference to other drawings even if they are not mentioned or described in the corresponding drawings. Also, elements without reference numbers may be described with reference to other drawings.

[0021] The terms used in the specification are for the purpose of describing certain exemplary embodiments only and are not intended to be limiting. Unless otherwise defined, all terms (including technical and scientific terms) used in the specification have the same meaning as commonly understood by one of ordinary skill in the art. As used herein, the singular is intended to include the plural unless the content clearly indicates otherwise. Also, the terms "at least one," "at least," and "one or more" are intended to include both the singular and the plural, as appropriate to the context. Furthermore, it should be understood that the terms "comprise" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise indicated, terms such as "first" and "second" are only used to distinguish elements from one another. For example, one fitting can be referred to as a "first fitting," and similarly, another fitting can be referred to as a "second fitting," or vice versa.

[0022] Unless otherwise indicated, spatially relative terms such as "below," "lower," "lower side," "upper," and "opposite side" may be used herein for ease of description in describing the relationship of an element or feature to another element or feature as depicted in the figures. It should be understood that spatially relative terms are intended to include different orientations in addition to those depicted in the figures. For example, an element described as being "below" or "below" another element or feature would be oriented "above" the other element or feature if the object in the figure were inverted. Thus, the exemplary term "below" may include both an upward and downward orientation. If an object is oriented in another way (e.g., rotated 90 degrees or at another orientation), 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 figures for the purpose of facilitating the reader's understanding of the figures and the specification, but do not necessarily indicate that any particular feature or element is aligned or orthogonal to other features or elements.

[0023] Paragraph numbers used herein, unless specifically noted, are for organizational purposes only and should not be construed as limiting the subject matter described. It will be understood that many different forms, embodiments and combinations are possible without departing from the spirit and teachings of the present disclosure, and the present disclosure should not be construed as being limited to the example embodiments described herein. Rather, these examples and embodiments are provided so that this disclosure will be complete and all-inclusive, and will fully convey the scope of the disclosure to those skilled in the art.

[0024] The embodiments disclosed herein relate generally to vibration isolation assemblies (also referred to herein as "pneumatic isolators", "vibration isolators", or "isolators"). One particular application of vibration isolation assemblies is as an optical table system. A typical optical table system includes an optical table top and one or more (e.g., four) vibration isolation assemblies capable of supporting the optical table top. The optical table top is often constructed of upper and lower plates with a honeycomb core located between the plates, providing a lightweight rigid structure for its size and rigidity. Optical table systems are used for experiments requiring lasers, optical components (e.g., lenses, mirrors, prisms), light measurement equipment (e.g., photodetectors, power meters, cameras), among other equipment. Such experiments are particularly sensitive to vibrations, and the vibration isolation assemblies described herein are used to prevent floor vibrations (also referred to herein as "input vibrations" or "excited vibrations") (e.g., from people walking, elevator movements in buildings, passing vehicles, and rotating machines such as electric motors) from reaching the equipment mounted on the optical tabletop. In addition, the vibration isolation assemblies described herein are also used to prevent or reduce vibrations from the optical tabletop to the floor or other supporting surface (e.g., another optical tabletop). Excited vibrations occur at various frequencies or frequency ranges depending on the source, and are typically measured in units of Hertz (Hz). The term "transmissibility" as used herein is defined as the amount of excited vibration that is transferred from one mass to another mass (e.g., from the floor to the optical tabletop or vice versa).

[0025] FIG. 1 shows a schematic cross-sectional view of an isolation assembly 10. The isolation assembly 10 includes a housing 14 defining a single air chamber 16 of 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 of mass m1. The isolation assembly 10 is supported on a support surface 20. In operation, the air chamber 16 acts as a spring to prevent the transmission of vibrations between the support surface 20 and the payload 24. The isolation assembly 10 is also referred to herein as a "single chamber isolator 10."

[0026] 2 shows a mechanical model of a single chamber isolator 10 with a payload 24 of mass m1, where the combined stiffness of the air chamber and diaphragm is shown as K1. Returning to FIG1, a known problem with the design of a single chamber isolator 10 is that any vibration excitation of the support surface 20, i.e., a transient excitation of the support surface 20, can cause excessive resonant vibration of the payload 24 at the resonant frequency of the oscillator defined by the stiffness K1 and mass m1.

[0027] FIG. 3 shows a schematic cross-sectional view of an isolation assembly 30 (also referred to herein as a "two-chamber isolator 30") including a vibration damping portion provided as a flow-resistance orifice 46 configured to provide pneumatic communication between two air chambers. The isolation assembly 30 includes a housing 34 and a partition 44 defining a first air chamber 36 (also known as a "follower chamber") of volume V1 and a second air chamber 38 (also known as a "damping chamber") of volume V2. The first air chamber 36 and the second air chamber 38 are in pneumatic communication with each other via the flow-resistance orifice 46 designed to provide a viscous flow of gas between the chambers 36 and 38. The first chamber 36 is sealed by a diaphragm 32 supporting a mass-engaging member 48 (e.g., a piston) configured to support a payload 50 of mass m1 (e.g., an optical tabletop or a portion of an optical tabletop). The isolation assembly 30 is supported on a support surface 42 (e.g., a floor). During operation, the air chambers 36 and 38 act as springs to prevent transmission of excited vibrations between the payload 50 and the support surface 42, effectively isolating the payload from excited vibrations from the support surface 42. The flow-resisting orifices 46 provide energy dissipation to prevent or reduce excessive sympathetic vibrations.

[0028] FIG. 4 shows a mechanical model of a two-chamber isolator 30 with a payload 50 of mass m1, where 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 low excitation frequencies (f→0), the resistance to gas flow through the flow-resistance orifice 46 is small and the dynamic stiffness K(f) of the dual-chamber isolator 30 reaches a minimum value K L , which corresponds to the first and second chambers 36, 38 acting as a single chamber. As the excitation frequency increases, the resistance to gas flow through the flow-resistance orifice 46 increases, and the dynamic stiffness K(f) of the dual-chamber isolator 30 reaches its highest limit value K H, which corresponds to the first chamber 36 operating alone. As a result, at low excitation frequencies the two-chamber isolator operates like a large volume isolator (e.g., having a volume equal to V1+V2) that is more effective at low natural frequencies, and at high excitation frequencies the two-chamber isolator operates as a small volume isolator (e.g., having a volume equal to V1) that is not as effective at high natural frequencies.

[0029] Figure 5 shows a graph of vibration transmissibility between a support surface and a payload as a function of the frequency (f) of the exciting vibration for a constant mass = m1, illustrating the trade-off between damping of resonant vibrations at high frequencies and vibration isolation performance. Figure 5 shows the transmissibility curve of an isolation assembly 10 with a payload m1 (shown as a dotted line) and an isolation assembly 30 with the same payload m1 and the same total air volume (shown as a solid line). At an exciting frequency f = 50 Hz, the transmissibility of the single chamber isolator 10 is approximately 3 x 10 -3 However, the transmission rate of the two-chamber isolator 30 is approximately 3×10 -2 This results in a difference in transmissibility ΔT between the vibration isolators 10 and 30 on a logarithmic scale. 50 =10, which is a difference in magnitude of the order of 10.

[0030] At a resonant frequency of f=1 Hz, the transmissibility of the single chamber isolator 10 is approximately 20 and the transmissibility of the two chamber isolator 30 is approximately 5. This results in a transmissibility difference ΔT1=4 at 1 Hz. This represents a four-fold difference between the transmissibility of the single chamber isolator 10 and the two chamber isolator 30. In many applications, such a high transmissibility at the resonant frequency is unacceptable, so the two chamber isolator design is preferred as it provides damping, whereas the single chamber isolator design does not, and the better vibration isolation performance at high frequencies of the single chamber isolator 10 is not worth the trade-off of poor vibration isolation performance at resonance. It is important to note that the transmissibility curves shown in FIG. 5 are typical of the single chamber and two chamber isolator designs. The exact transmissibility curves and frequency response of the single chamber and two chamber isolator designs may vary depending on the payload mass and various other conditions.

[0031] 6 shows a schematic cross-sectional view of an embodiment of an isolation assembly 100 configured to prevent or reduce the transmission of excited vibrations between a support surface and a payload at high vibration excitation frequencies, with improved performance at low frequencies compared to that of the isolation assembly 10. In this embodiment, the isolation assembly 100 includes a volume V in pneumatic communication with a pressure source (not shown) formed therein. h6 includes a housing assembly 300 including a housing body 302 having an air chamber 310 of m. The embodiment shown in FIG. 6 includes a single air chamber formed in the housing body 302, however, one skilled in the art will appreciate that any number of air chambers of various sizes, shapes, and / or cross-sectional dimensions may be formed in the housing body 302. The air chamber 310 is sealed by a diaphragm 330 that engages and supports a mass engagement 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 of mass m (e.g., an optical table or a portion of an optical table). The housing body 302 and mass engagement member 400 may be formed from a variety of materials, including, but not limited to, aluminum, steel, stainless steel, copper, brass, bronze, polymers, composites, and ceramic materials. In one embodiment, the mass m is approximately 500 kilograms, however, one skilled in the art will appreciate that the vibration isolation assembly 100 may be configured to support payloads having a variety of masses. In this embodiment, the air chamber 310 is configured to receive a thermally conductive compressible fluid 320 at a pressure selected to support the mass engagement member 400 and the payload 500. In this embodiment, the fluid 320 is air, although one skilled in the art would understand that any compressible fluid (e.g., an inert gas such as argon, helium, nitrogen, etc.) may be used. In other embodiments, the fluid 320 may include a liquid. Thus, the air chamber 302 may instead include a hydraulic chamber. In other embodiments, the fluid 320 may include both a gas and a liquid. Thus, in other embodiments, the air chamber 320 may form a fluid chamber configured to support the mass engagement 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 floor or other structure).The vibration isolation assembly 100 further includes at least one thermally conductive member 340 in thermal communication with the housing body 302, located within the air chamber 310, and configured to absorb thermal energy generated in the air chamber 310 from the compression of the fluid 320 and transfer the thermal energy to the housing body 302. From the housing body 302 the thermal energy is transferred to the surrounding environment. The thermal energy may be transferred away from the housing body 302 or to the surrounding environment by radiation, free convection, or forced convection (e.g., a fan directed at the housing body 302). In general, the thermally conductive member 340 is configured to place the thermally conductive material in intimate contact with as much of the fluid 320 as possible. In this embodiment, the thermally conductive member 340 has a volume V. h 6 as volume 350. Anti-vibration assembly 100 with thermally conductive member 340 is also referred to herein as "thermally conductive isolator 100." In one embodiment, mass engaging member 400 may be positioned in thermal communication with payload 500 such that mass engaging member 400 may absorb thermal energy from air chamber 310 and transfer it to payload 500 and / or the surrounding environment.

[0032] The thermally conductive member 340 expands as the fluid 320 dynamically compresses during the oscillatory changes in the air volume as the mass-engaging member 400 moves vertically while supporting the payload 500. h The thermally conductive member 340 is configured to absorb heat energy generated within the air chamber 310. Because air or other gases that may be used as fluid 320 have poor thermal conductivity, 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, effectively increasing the thermal conductivity of the air within the air chamber 310. To do so, the thermally conductive member 340 is generally configured to absorb heat energy generated within the volume V of the air chamber 310. hThe thermally conductive member 340 may be provided as a porous thermally conductive structure that transfers thermal energy generated within the mass engaging member 400 to the housing body 302 from where it is transferred to the surrounding environment. The thermally conductive member 340 may be provided as a thermally conductive body having a plurality of channels formed therein. In this embodiment, the thermally conductive member 340 is provided as a honeycomb structure (such as that shown in FIG. 10) having hexagonal flow passages oriented parallel to the vertical movement of the mass engaging member 400. While many honeycomb structures have cells having a hexagonal shape or geometry, the term "honeycomb" as used in describing the embodiments herein should not be construed as being limited to a hexagonal shape or geometry and thus may have other shapes or geometries. The honeycomb structure may be formed from a variety of materials, including, but not limited to, aluminum, steel, stainless steel, copper, copper-tungsten, brass, bronze, polymers, composites, ceramic materials, and nanostructured materials (e.g., carbon nanotubes).

[0033] FIG. 10 shows a detailed cross-sectional plan view of an embodiment of a honeycomb structure used to form the thermally conductive member 340 located within the housing body 302. The honeycomb structure includes a plurality of cells 344 that vertically penetrate the air chamber 310. Each cell 344 defines an air volume 348 and shares at least one thermally conductive cell wall 346 with at least one adjacent cell. As a result, thermal energy can be conducted along the walls of each cell to the walls of the adjacent cells and ultimately to the housing body 302 from where it can be radiated, conducted, or convected to the surrounding environment. In this embodiment, each cell 344 has a width H, although in some embodiments, each cell may have a different width. When so configured, each fluid molecule within the air volume 348 is located only a distance H / 2 away from the thermally conductive cell wall 346, effectively increasing the thermal conductivity of the gas within the air chamber 310 shown in FIG. 6. In this embodiment, the cells are 6 millimeters wide, meaning that all of the fluid molecules within the honeycomb structure are no more than 3 millimeters from the thermally conductive material that forms the cell walls 346. In the illustrated embodiment, each cell 344 has the same width, although in other embodiments, the cells 344 may have different widths.

[0034] In one embodiment, as shown in FIG. 9 , the thermally conductive member 340 is placed in direct contact with the housing body 302 by forcing the honeycomb structure into the housing body 302 such that a portion of the outer honeycomb cells 344 deforms at the junction 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 other fluid may be forced (e.g., by a fan) through the air volume 348 of each cell 344 to convectively conduct thermal energy away from the respective cell 344 and into the housing body 302. In another embodiment, air or other fluid may be drawn (e.g., by a fan or vacuum pump) through the air volume 348 of each cell 344 to advect thermal energy away from the respective cell 344 and into the housing body 302. In other embodiments, the fluid 320 may be circulated through the different cells 344 by a variety of different devices or methods. In this embodiment, the total volume of air in the honeycomb cells is equal to the total volume V of the air chamber 310 (see FIG. 6). h 90% of the mass of the honeycomb cells 344, while the remaining volume 350 above the thermally conductive member 340 provides sufficient space to allow the mass-engaging member 400 to move vertically during operation. The respective proportions of the air volume in the honeycomb cells 344 and the remaining volume 350 may be adjusted to provide optimal vibration isolation performance for various applications. For example, in one embodiment, for a vibration environment where the excitation frequency is expected to be in the range of 40-55 Hz, the proportion may be 90% / 10%. In another embodiment, for a vibration environment where the excitation frequency is expected to be in the range of 56-70 Hz, the proportion may be 80% / 20%.

[0035] In another embodiment, one or more thermal conductors, such as a hexagonal shaped conductor 600, may be disposed within one or more of the honeycomb cells 344, as shown in FIG. 10. In another embodiment, one or more thermal conductors 650 having a circular cross section may be inserted into the thermally conductive member 340 to increase the thermal conductivity from the thermally conductive member 340 to the housing body 302. In one embodiment, the thermal conductors 600, 650 may be provided as solid metal (e.g., copper) rods. In another embodiment, the conductors 600, 650 may be provided as heat pipes. One skilled in the art will appreciate that any type or number of thermal conductors may be disposed within the thermally conductive member 340.

[0036] While the cells 344 in the embodiment depicted in FIG. 10 have a hexagonal shape, 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 have a star shape or a random shape. One skilled in the art will appreciate that the cells 344 may be formed in many different shapes configured to maximize or regulate the heat transfer from the fluid 320 inside the air chamber 310 to the housing 304 and then to the surrounding environment. While the possible shapes listed above may describe exact geometric shapes, one skilled in the art will appreciate that manufacturing methods may produce shapes approximating the shapes listed above without departing from the spirit and teachings of the present disclosure.

[0037] Returning to FIG. 6, the thermally conductive member 340 may be formed from a variety of materials having different thermal conductivities and different mechanical configurations. Exemplary materials for the thermally conductive member 340 include, but are not limited to, aluminum, steel, stainless steel, copper, copper-tungsten, brass, bronze, polymers, diamond, composites, 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 237-247 W / mK, which is approximately 9,000 times that of air. The thermal conductivity of copper is 398 / 390 W / mK. The thermal conductivity of tungsten is approximately 173 W / mK. Additionally, the thermally conductive member 340 may be formed from a variety of materials having different specific heats measured in units of joules per kilogram-Kelvin (J / kg-K). For example, in one embodiment, the thermally conductive member 340 may be formed from aluminum, which has a specific heat of approximately 920 J / kg-K. In another embodiment, the thermally conductive member 340 may be formed from copper, which has a specific heat of approximately 377 J / kg-K. Those skilled in the art will appreciate that the thermally conductive member 340 may be formed from materials having a variety of specific heats.

[0038] Returning to FIG. 6, in some embodiments, one or more additional thermally conductive members or devices 360 may be disposed in thermal contact with the outer periphery of the housing body 302 to maximize the transfer of thermal energy from the housing body 302 to the surrounding environment. In one embodiment, the thermally conductive 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 number of cooling fins (not shown). Exemplary materials for 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 that transfers thermal energy to the surrounding environment by radiation or free convection. In other embodiments, the heat sink 360 may include one or more fans capable of directing air flow over the heat sink 360 to transfer thermal energy to the surrounding environment by forced convection. In other embodiments, heat sink 360 may include one or more thermoelectric coolers. In yet other embodiments, a thermally conductive member may be disposed between housing body 302 and support surface 200 to allow thermal energy from housing body 302 to be conducted to support surface 200 and then to the surrounding environment. One skilled in the art will appreciate that any type or number of heat sinks or other heat transfer devices may be disposed in thermal communication with housing body 302 and the surrounding environment.

[0039] 7 shows an experimental graph of vibration transmissibility between a support surface and a payload as a function of the frequency of the exciting vibration to compare the transmissibility of the dual chamber isolator 30 and at least one embodiment of the thermally conductive isolator 100 as described with respect to FIG. 6. Both isolators have the same total air volume and support the same load. The transmissibility of the vibration isolation assembly 100 is lower than that of the dual chamber isolator 30 starting at an exciting frequency of about 4 Hz. At approximately 50 Hz, the transmissibility of the vibration isolation assembly 100 is about 2×10 -4and the transmissibility of the vibration isolation assembly 30 is approximately 2×10 -3 This is the difference in transmissibility ΔT at 50 Hz on a logarithmic scale. 50 = 10, which is a difference in magnitude of 10 times.

[0040] At a resonant frequency of around 1 Hz, the thermally conductive isolator 100 has a transmissibility of about 4 and the two-chamber isolator 30 has a transmissibility of about 3. This results in a transmissibility difference at 1 Hz of ΔT1=1.33, which means that at resonance, the thermally conductive isolator 100 has approximately 1.33 times the transmissibility of the two-chamber isolator 30. In many applications, such a trade-off is acceptable since the thermally conductive isolator 100 has only a slightly higher transmissibility than the two-chamber isolator at resonance, and at 50 Hz has a transmissibility ten times lower than the two-chamber isolator.

[0041] The transmissibility curve of the thermally conductive isolator 100 shown in FIG. 7 is illustrative of only one embodiment of the thermally conductive isolator 100. The thermally conductive isolator 100 may have various types of transmissibility curves, i.e., frequency / isolation response to excitation vibration, depending on the payload mass, the exact design of the thermally conductive isolator 100, and various other conditions. For example, in one embodiment, the thermally conductive isolator 100 may have a resonant frequency between 1 and 50 Hz, or may resonate at an excitation frequency between 1 Hz and 50 Hz. In one embodiment, the excitation vibration may be a multiple of the resonance frequency. For example, in one embodiment, the excitation vibration may be 5-10 times the resonance frequency, although one skilled in the art will appreciate that the excitation vibration may be any multiple of the resonance frequency. In one embodiment, the thermally conductive isolator 100 may be configured to have a lower transmissibility (e.g., for a two-chamber isolator) at an excitation vibration frequency in the range of 2 Hz to 20 Hz. In other embodiments, the thermally conductive isolator 100 may be configured to have a lower transmissibility at excitation vibration frequencies ranging from 5 Hz to 50 Hz. In other embodiments, the thermally conductive isolator 100 may be configured to have a lower transmissibility at excitation vibration frequencies ranging from 50 Hz to 500 Hz. One skilled in the art will appreciate that the thermally conductive isolator 100 may provide improved vibration isolation performance over a dual chamber isolator at any excitation vibration frequency, frequency range, or frequency band.

[0042] 8 shows a schematic cross-sectional view of an embodiment of a thermally conductive pneumatic isolator having an active heat transfer system, such as a thermal management system 1000, disposed in thermal communication with a thermally conductive member 340. In this embodiment, the vibration isolation assembly 100 has substantially the same configuration as described with respect to FIG. hThe thermal management system 1000 includes a housing assembly 300 having a housing body 302 defining an air chamber 310 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 supporting a payload 500 (e.g., an optical table or a portion of an optical table) having a mass m. In this embodiment, the thermal management system 1000 includes a heat transfer device 1002 extending into the air chamber 310 and the thermally conductive member 340. In this embodiment, the heat transfer device 1002 does not impede the flow of the fluid 320 from a region above the heat transfer device 1002 to a region below the heat transfer device 1002. Examples of the heat transfer device 1002 include, but are not limited to, an air-to-air heat exchanger, an air-to-water heat exchanger, a heat pipe, a heat pump, a forced air convection system, a thermoelectric cooler, or the like, or any combination thereof. In this embodiment, the heat-transfer device 1002 is in fluid and thermal communication with a secondary heat-transfer device 1006 (eg, a chiller) via a conduit, tube, or pipe 1004 .

[0043] 9-13 illustrate various embodiments of a thermally conductive member that may be disposed within the housing body 302 of the thermally conductive isolator 100. FIG. 9 illustrates an embodiment of the housing body 302 having a thermally conductive member 340 provided as a honeycomb structure. In this embodiment, the housing body 302 includes a plurality of extended regions 304 formed therein, each of which has a fastener passage 306 formed therein that is configured to receive a fastener (not shown) used to fasten the housing body 302 to other components of the vibration isolation assembly 100. A plurality of reliefs 342 are formed in the thermally conductive member 340, each of which corresponds to an extended region 304 of the housing body 302, such that physical and thermal contact between the thermally conductive member 340 and the inner surface of the housing body 302 is maximized.

[0044] FIG. 10 illustrates a detailed cross-sectional plan view of an embodiment of a honeycomb structure used to form a thermally conductive member 340 located within the housing body 302. The embodiment illustrated in FIG. 10 is described in more detail above with respect to FIG. 6. The honeycomb structure includes a plurality of cells 344 that extend vertically through the air chamber 310. Each cell 344 defines an air volume 348 and shares at least one thermally conductive cell wall 346 with at least one adjacent cell. As a result, thermal energy is conducted along the wall of each cell to the wall of an adjacent cell and ultimately to the housing body 302 from where it can be radiated, conducted, or convected to the surrounding environment. In this embodiment, each cell 344 has a width H, although in some embodiments, each cell may have a different width.

[0045] 11 illustrates a plan cross-sectional view of the housing body 302 having a thermally conductive member 700 disposed therein. In one embodiment, the thermally conductive member 700 is formed from a wire mesh or wire wool configured to absorb thermal energy in the air chamber 310 and conduct it to the housing body 302. In another embodiment, the thermally conductive member 700 may be formed from a plurality of rectangular tubes or other rectangular members having an air volume formed therein and configured to absorb thermal energy in the air chamber 310 and conduct it to the housing body 302. In another embodiment, the thermally conductive member 700 may be formed from a porous metal foam or other porous foam formed from a thermally conductive material that allows fluid 320 to circulate between the cells such that thermal energy generated in the air chamber 310 is conducted to the housing body 302.

[0046] 12 illustrates a cross-sectional plan view of the housing body 302 having a thermally conductive member 800 disposed therein. In one embodiment, the thermally conductive member 800 is formed from a plurality of thermally conductive plates (e.g., formed from aluminum or other thermally conductive material) configured to absorb thermal energy in the air chamber 310 and conduct it to the housing body 302. In other embodiments, the thermally conductive member 800 may be formed from a plurality of heat sinks disposed within the housing body 302 and configured to absorb thermal energy in the air chamber 310 and conduct it to the housing body 302.

[0047] 13 illustrates a cross-sectional plan view of the housing body 302 having a thermally conductive member 900 disposed therein. In one embodiment, the thermally conductive member 900 is formed from a plurality of circular tubes or pipes arranged in thermal communication with one another, with an air volume formed within each of the tubes or pipes, configured to absorb thermal energy within the air chamber 310 and conduct it to the housing body 302.

[0048] 14 illustrates an embodiment of a housing 380 that may be used within the thermally conductive isolator 100. In this embodiment, the housing 380 includes a housing body 382 having a thermally conductive member 390 disposed therein. In this embodiment, the housing body 382 includes a plurality of extension regions 386 formed therein, each having a fastener passage 388 formed therein that is configured to receive a fastener (not shown) that is used to fasten the housing body 382 to other components of the thermally conductive isolator 100. The housing body 382 has a plurality of heat transfer members 384 (e.g., cooling fins) formed on at least one inner surface thereof that are configured to conduct thermal energy from the heat transfer members 390 (and elsewhere within the air chamber 310 of the vibration isolation assembly 100) to the exterior of the housing body 382, ​​from where the thermal energy may be dissipated to the surrounding environment. Thermally conductive member 390 may be formed from any of the materials or configurations discussed above with respect to thermally conductive member 340. In another embodiment, thermal transfer member 384 may extend further into housing body 382 and may be configured to collectively provide sufficient thermal conductivity to the air within air chamber 310 such that a separate thermally conductive member 390 is not required. Thus, multiple thermal transfer members 384 may effectively form a thermally conductive member monolithically formed with housing body 382. In other embodiments, thermally conductive member 390 may be provided as a 3D printed structure formed separately or monolithically with housing body 382.

[0049] The above describes the embodiments and examples of the present invention and should not be construed as being limiting thereto. Although some specific embodiments and examples have been described with reference to the drawings, those skilled in the art will readily recognize that many modifications to the disclosed embodiments and examples and other embodiments are possible without significantly departing from the novel teachings and advantages of the present invention. Accordingly, 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, those skilled in the art will understand that the subject matter of any sentence, paragraph, example or embodiment can be combined with some or all of the subject matter of any other sentence, paragraph, example or embodiment, unless such combinations are mutually exclusive. Thus, the scope of the present invention should be determined by the following claims and the equivalents of such claims to be included therein.

Claims

1. A vibration isolation assembly configured to reduce the transmission of at least one vibration between at least one support surface and at least one payload, A housing having at least one housing body having at least one air chamber formed inside which is configured to receive at least one air fluid, and the at least one housing being supported by at least one support surface, At least one mass engaging member supported by the at least one air 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 thermal conductive member located inside the at least one air chamber and thermally in contact with the at least one housing body, Equipped with, The at least one first thermal conductive member is configured to transfer a quantity of thermal energy from the at least one air fluid in the at least one air chamber to the at least one housing body. The transfer of thermal energy from the at least one air fluid to the at least one housing body reduces the transmission of vibration from the at least one support surface to the at least one payload. Vibration isolation assembly.

2. The vibration isolation assembly according to claim 1, wherein the at least one first heat-conducting member is at least one honeycomb structure.

3. The vibration isolation assembly according to claim 2, wherein at least one of the honeycomb structures is made of metal.

4. The vibration isolation assembly according to claim 1, wherein the at least one first thermal conductive member includes at least one thermal conductive body having a plurality of channels formed inside.

5. The vibration isolation assembly according to 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, rectangular, triangular, pentagonal, hexagonal, octagonal, trapezoidal, circular, elliptical, and oval.

6. The vibration isolation assembly according to claim 1, wherein the at least one first heat-conducting member is formed from at least one metal mesh.

7. The vibration isolation assembly according to claim 1, wherein the at least one first heat-conducting member is formed from a plurality of metal tubes.

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

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

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

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

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

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

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

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

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

17. The vibration isolation assembly according to claim 15, wherein the at least one vibration is about 10 times the vibration at the resonant frequency.

18. The vibration isolation assembly according to claim 1, wherein the at least one payload is at least one optical tabletop.

19. The vibration isolation assembly according to claim 1, further comprising at least one second heat-conducting member fixed to at least one outer surface of the at least one housing body.

20. The vibration isolation assembly according to claim 19, wherein the at least one second heat-conducting member is at least one heat sink.

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

22. The vibration isolation assembly according to claim 1, wherein the at least one air chamber is arranged to be in thermal contact with at least one heat-conductive fluid that is in contact with at least one outer surface of the at least one housing body.

23. The vibration isolation assembly according to claim 1, wherein the at least one first thermal conductive member is formed monolithically with the at least one housing body.

24. The vibration isolation assembly according to claim 1, wherein the at least one first thermally conductive member is in thermal contact with the at least one payload.

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

26. The vibration isolation assembly according to claim 25, wherein the at least one thermal management system includes at least one heat exchanger.

27. The vibration isolation assembly according to claim 26, wherein the at least one heat exchanger is in fluid communication with at least one secondary heat transfer device.

28. The vibration isolation assembly according to claim 26, wherein the at least one heat exchanger is at least one air-to-air heat exchanger.

29. The vibration isolation assembly according to claim 26, wherein the at least one heat exchanger includes at least one thermoelectric cooler.

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

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