Heavy-load precise gas-magnetic composite low-frequency micro-vibration isolator for high-end instrument equipment

Abstract

A heavy-load precise gas-magnetic composite low-frequency micro-vibration isolator for high-end instrument equipment belongs to the technical field of precise vibration isolation and is formed by coaxially nesting a movable magnetic ring array and a fixed magnetic ring array, the movable magnetic ring array and the fixed magnetic ring array are both formed by 2n + 1 (n > = 1, n belongs to N +) layers of uniform-section magnetic rings which are arranged in an array manner along the axial direction and are vertically magnetized between the adjacent layers, the overall structure is vertically symmetrical about the (n + 1) th layer of magnetic ring; first-layer magnetic rings of the movable magnetic ring array and the fixed magnetic ring array are magnetized reversely along the radial direction, and the bottom surfaces of the first-layer magnetic rings coincide; when one layer is added, the magnetization direction of the movable magnetic ring is clockwise rotated by 90 degrees, and the magnetization direction of the fixed magnetic ring is anticlockwise rotated by 90 degrees; the device is simple in structure and convenient to install and maintain, high negative rigidity and zero magnetic force characteristics can be generated, the dynamic vibration isolation rigidity is reduced under the condition that heavy-load precise micro-vibration isolation bearing of dozens of tons to thousands of tons is not changed, and low-frequency or near-zero-frequency vibration isolation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of precision vibration isolation, in particular to a heavy-load precision gas-magnetic composite low-frequency micro-vibration isolation device for high-end instruments and equipment. Background Art

[0002] With the rapid iteration and upgrading of large-scale precision processing equipment, measuring instruments and large-scale cutting-edge scientific experimental systems, the processing and measurement accuracy of high-end precision instruments and equipment has entered the nanometer and sub-nanometer levels, and their sensitivity to micro-vibrations in the environment has gradually increased. Even low-frequency, micro-vibration interference that cannot be detected by human senses can seriously affect the accuracy of large-scale precision processing equipment, measuring instruments and large-scale cutting-edge scientific experimental systems. Therefore, it is necessary to weaken or isolate environmental vibrations, especially low-frequency, micro-vibrations, which are crucial to the accuracy of high-end precision instruments and equipment in the fields of large-scale precision processing, measurement and cutting-edge scientific experiments.

[0003] Stiffness is the core parameter that determines the vibration isolation bandwidth, and is directly related to the effect of the micro-vibration isolation platform on vibrations of different frequencies. The smaller the stiffness of the micro-vibration isolator, the wider the vibration isolation frequency band and the better the low-frequency micro-vibration isolation effect; however, the low stiffness characteristics will lead to high static deformation, low stability and weak anti-interference ability, reducing the load-bearing capacity of the micro-vibration isolation platform. Therefore, how to reduce the vibration isolation stiffness without affecting the load-bearing capacity is the key to improving the vibration isolation performance. The parallel negative stiffness structure can reduce the vibration isolation stiffness and expand the vibration isolation frequency band without affecting the load-bearing capacity. However, the existing research on negative stiffness structures is mainly aimed at small optical micro-vibration isolation platforms and devices, the mass of which is usually within kilograms to hundreds of kilograms; when facing large-scale precision processing equipment, measuring instruments, and large-scale cutting-edge scientific experimental systems, which require heavy-duty micro-vibration isolation of tens of tons to thousands of tons, the negative stiffness generated is low, and the effect of reducing the vibration isolation stiffness and expanding the vibration isolation bandwidth is minimal. Therefore, for large-scale precision micro-vibration isolation systems with large load-bearing capacity, large size and complex structure, how to reduce their vibration isolation stiffness and expand the vibration isolation frequency band is the key to achieving high-performance vibration isolation.

[0004] Patent No. CN202010897879.X discloses a bistable nonlinear energy device based on electromagnetic negative stiffness. The upper and lower magnetic rings and the upper and lower coils exert attractive force on the middle magnetic ring to form an online adjustable electromagnetic negative stiffness spring. The electromagnetic negative stiffness spring and the pressure spring are connected in parallel to form a bistable nonlinear energy device. When the coil is not energized, the performance of the permanent magnetic negative stiffness is adjusted by adjusting the distance between the upper and lower magnetic rings and the middle magnetic ring. When the coil is energized, the electromagnetic negative stiffness performance is adjusted in real time by adjusting the current in the upper and lower coils and the distance between the upper and lower coils and the middle magnetic ring. Patent No. CN202211512185.5 discloses a low-frequency vibration isolation device based on linear magnetic negative stiffness, which realizes linear magnetic negative stiffness through three magnetic rings arranged with equal spacing along the axial direction and coaxial annular coils configured outside each permanent magnet, wherein the three annular coils are arranged vertically coaxially and symmetrically to form an attractive electromagnetic negative stiffness mechanism, and the three magnetic rings and three annular coils are arranged vertically coaxially and symmetrically to form a repulsive electromagnetic negative stiffness mechanism, and the coupling of the attractive electromagnetic negative stiffness mechanism and the repulsive electromagnetic negative stiffness mechanism realizes the nonlinear offset of the softening stiffness characteristic and the hardening stiffness characteristic. Patent No. CN202311009285.0 discloses a magnetic vibration isolation device and a vibration isolation method with adjustable stiffness, which realizes the adjustable negative stiffness characteristic through four cubic moving permanent magnets arranged inside the vibration isolator and a pair of cubic permanent magnets and a pair of electromagnets fixedly installed in a cross shape. Among them, the adjustable gap between the moving permanent magnet and the fixed permanent magnet realizes the coarse adjustment of the negative stiffness, and the current in the electromagnet realizes the fine adjustment of the negative stiffness. The above technical solutions are all composed of cubic permanent magnets or annular permanent magnets and other gap array arrangements, which have significant magnetic leakage problems and can provide relatively low negative stiffness values.

[0005] Professor Cui Junning of Harbin Institute of Technology proposed an ultra-low frequency air spring isolator (1. "Air spring isolator based on electromagnetic negative stiffness structure", ZL202010605223.6; 2. Ultra-low frequency air spring isolator based on axially magnetized magnetic ring negative stiffness structure, ZL202010606309.0; 3. Large-load ultra-low frequency air spring isolator based on negative stiffness magnetic spring, ZL202010605236.3; 4. Ultra-low frequency isolator based on vertically magnetized magnetic ring negative stiffness structure, ZL202010605241.4), which uses radially reversed magnetization, axially co-magnetized, and mutually perpendicular magnetization inner and outer magnetic rings to achieve negative stiffness characteristics, and uses the eddy currents generated by the relative motion of the inner and outer magnetic rings to work together with the built-in throttle holes to form an efficient damping mechanism, thereby effectively attenuating vibration energy and improving the stability and vibration isolation performance of the vibration isolation system. Patent No. CN202311375790.7 discloses a high linear magnetic negative stiffness mechanism with stator-motor staggered configuration, which coaxially nests stator magnetic rings and mover magnetic rings with the same excitation direction and repulsive magnetic force, and arranges them in multiple layers along the z direction or alternately in multiple columns along the horizontal direction to increase the negative stiffness value provided by the force between the stator magnetic ring and the mover magnetic ring in the z direction, and improves the linearity of the negative stiffness characteristics by setting an initial bias between the mover magnetic ring and the stator magnetic ring of the same layer. Compared with the negative stiffness structural scheme based on equal gap array arrangement of cubic permanent magnets, the scheme of coaxial nesting of inner and outer magnetic rings with radial reverse magnetization, axial same direction magnetization, and perpendicular magnetization, and arranging them in equal gap arrays along a certain direction can improve the negative stiffness value. However, in the above technical scheme, the stator and the mover in the negative stiffness mechanism are both single magnetic rings that are radially magnetized or axially magnetized. For such magnetic rings that are uniformly magnetized along a certain direction, the excitation magnetic fields formed on their inside, outside or upper and lower sides are symmetrical, but only one side of the magnetic field is utilized, while the other side is idle, resulting in that the magnetic field utilization rate of this scheme still needs to be optimized, and the resulting negative stiffness value has little effect on reducing the stiffness of large-scale precision micro-vibration isolation platforms weighing tens to thousands of tons.

[0006] In summary, how to provide a device that can reduce the stiffness of heavy-load precision micro-vibration isolation through structural and principle innovation and expand the low-frequency vibration isolation band is of great significance to reducing the interference of environmental micro-vibrations on high-end precision instruments and equipment, ensuring the optimal working environment of high-end precision instruments and equipment, and thus improving the accuracy of high-end precision instruments and equipment. Summary of the invention

[0007] The core goal of the present invention is to solve the negative impact of environmental vibration interference on high-end precision instruments and equipment, and to design a high-end instrument and equipment heavy-duty precision gas-magnetic composite low-frequency micro-vibrator using composite magnetic levitation technology and precision air flotation system. The device utilizes a multi-layer vertically magnetized equal-section magnetic ring array to enhance the working side magnetic field, weaken the non-working side magnetic field, and form a unilateral high magnetic density magnetic field. The vertically magnetized moving magnetic ring array and the fixed magnetic ring array are coaxially nested to achieve high negative stiffness characteristics, and are connected in parallel with a large air flotation isolator to reduce the natural frequency of the vibration isolation and expand the vibration isolation range. This design can provide an "ultra-quiet" environment for ultra-precision instruments such as ultra-precision lithography machines, high-resolution satellite cameras, and ultra-precision machine tools, significantly improving the accuracy of high-end instruments.

[0008] The technical solution of the present invention is:

[0009] High-end instrument equipment heavy-duty precision air-magnetic composite low-frequency vibration isolation device, using air flotation to stably support loads of tens to thousands of tons, and combined with magnetic levitation technology to produce high negative stiffness characteristics, effectively reducing the vibration isolation stiffness, and achieving low-frequency or even near-zero-frequency vibration isolation; it is characterized by: including a load platform, a vertically magnetized space negative stiffness array and a large air-floating vibration isolation device; the large air-floating vibration isolation device includes an upper cover plate, an elastic membrane, a main gas tank, an additional gas tank and compressed gas, the upper cover plate is fixedly connected to the load platform, and forms a closed air chamber with the elastic membrane and the main gas tank, and compressed gas is introduced into the closed air chamber; the vertically magnetized space negative stiffness array includes a coaxially mounted moving magnetic ring mounting part, a moving magnetic ring array, a fixed magnetic ring array and a fixed magnetic ring fixing part, which are arranged in sequence from the axis along the radius outward, and the moving magnetic ring The mounting piece is a cylindrical structure with a T-shaped cross-section, the top of which is fixedly connected to the load platform, and the bottom of which maintains a certain gap with the ground; the dynamic magnetic ring array is tightly matched and fixedly mounted on the outer side of the dynamic magnetic ring mounting piece, and its bottom is pressed and fixed by the dynamic magnetic ring positioning piece; a gap is provided radially between the dynamic magnetic ring array, the fixed magnetic ring array, and the fixed magnetic ring fixing piece, and the fixed magnetic ring fixing piece is an annular sleeve with deep grooves arranged along the circumference of the inner side, the bottom of which is fixed, and the top of which maintains a certain gap with the load platform; the fixed magnetic ring array is tightly matched and fixedly mounted in the deep groove on the inner side of the fixed magnetic ring fixing piece, and its top is pressed and fixed by the fixed magnetic ring positioning piece; the dynamic magnetic ring array and the fixed magnetic ring array are both composed of 2n+1 layers of equal-section magnetic rings arranged in an axial array and perpendicularly magnetized between adjacent layers, where n≥1, n∈N + ; The heights of the magnetic rings in the same layer in the moving magnetic ring array and the fixed magnetic ring array are equal, and the heights of the magnetic rings in the odd-numbered layers are equal, and the heights of the magnetic rings in the even-numbered layers are equal; the first layer of magnetic rings in the moving magnetic ring array and the fixed magnetic ring array are magnetized in opposite directions in the radial direction, and their bottom surfaces overlap; on the right half of the front cross-sectional view, with each additional layer, the magnetization direction of the moving magnetic ring rotates 90° clockwise, and the magnetization direction of the fixed magnetic ring rotates 90° counterclockwise.

[0010] Preferably, the vertical magnetization space negative stiffness array is arranged in adjacent gaps with the large air-floating isolation micro-vibrator or the vertical magnetization space negative stiffness array is coaxially nested and fixedly installed in the main gas tank of the large air-floating isolation micro-vibrator.

[0011] Preferably, the large air-floating micro-vibrator is sealed by a steel ring, an O-ring, a diaphragm or a pressure self-sealing method.

[0012] Preferably, the pressure of the compressed gas is 0.1 MPa to 0.8 MPa.

[0013] Preferably, the main gas tank is connected in series with a plurality of sealed additional gas tanks via throttle holes or gas pipes.

[0014] Preferably, the radially magnetized magnetic rings in the moving magnetic ring array and the fixed magnetic ring array are composed of a plurality of tile-shaped magnets uniformly magnetized in the radial direction, the number of tile-shaped magnets can be 4, 5, 6, 8, 10, 12 and 15, and the gap between adjacent tile-shaped magnets does not exceed 3°.

[0015] Preferably, the moving magnetic ring mounting part, the fixed magnetic ring fixing part, the moving magnetic ring positioning part and the fixed magnetic ring positioning part are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy metal materials.

[0016] Preferably, the numbers of throttling holes between adjacent additional gas tanks are different and their positions do not overlap.

[0017] Preferably, the throttling hole is in the shape of a triangle, a circle, a five-pointed star or other polygonal shapes.

[0018] The technical innovation and good effects of the present invention are:

[0019] (1) The present invention innovatively proposes a heavy-duty precision air-magnetic composite low-frequency isolation micro-vibrator for high-end instruments and equipment. The heavy-duty precision air-magnetic composite low-frequency isolation micro-vibrator uses a large-scale air-floating isolation micro-vibrator and a vertical magnetized space negative stiffness array in parallel to support the load platform, wherein the large-scale air-floating isolation micro-vibrator stably supports the load platform of tens to thousands of tons by air floating, and effectively isolates the vibration in the medium and high frequency bands; while the vertical magnetized space negative stiffness array uses magnetic levitation to produce high negative stiffness characteristics, and produces local low dynamic stiffness characteristics without affecting the bearing mass of the large-scale air-floating isolation micro-vibrator, thereby reducing the natural frequency of vibration isolation and expanding the bandwidth of vibration isolation, providing an "ultra-quiet" working environment for high-end instruments and equipment such as ultra-precision lithography machines, high-resolution satellite cameras, and ultra-precision machine tools. This is one of the innovative points that distinguish the present invention from the prior art.

[0020] (2) The present invention innovatively proposes a vertical magnetization spatial negative stiffness array with zero magnetic force and high negative stiffness characteristics. The vertical magnetization spatial negative stiffness array utilizes 2n+1 (n≥1, n∈N +) layers are arranged in an axial array and adjacent layers are magnetized perpendicularly to form an equal-section magnetic ring array, which is coaxially nested with a fixed magnetic ring array to construct a unilateral high magnetic density magnetic field, which effectively weakens the magnetic field strength on the non-working side, while significantly enhancing the magnetic field strength on the working side, thereby producing a high-amplitude negative stiffness characteristic that is sufficient to reduce the stiffness parameters of large-scale precision micro-vibration isolation of tens to thousands of tons, and reduce the natural frequency of vibration isolation; in addition, the overall structure of the vertically magnetized spatial negative stiffness array is symmetrical about the n+1th layer of magnetic rings, and its axial magnetic force is zero, which can provide a configuration basis for reducing its vibration isolation stiffness without affecting the bearing capacity of heavy-load precision micro-vibration isolation. This is the second innovation of the present invention that distinguishes it from the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A three-dimensional view of a perpendicularly magnetized spatial negative stiffness array;

[0022] Figure 2 It is a front cross-sectional view of the perpendicular magnetization spatial negative stiffness array;

[0023] Figure 3 A three-dimensional diagram of Example 1 of a heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator for high-end instrument equipment;

[0024] Figure 4 A front cross-sectional view of Example 1 of a heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator for high-end instrument equipment;

[0025] Figure 5 A three-dimensional diagram of Example 2 of a heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator for high-end instrument equipment;

[0026] Figure 6 A front cross-sectional view of Example 2 of a heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator for high-end instrument equipment;

[0027] Figure 7 to Figure 13 Schematic diagram of the relative position and magnetization direction of the moving magnetic ring array and the fixed magnetic ring array when 4, 5, 6, 8, 10, 12 and 15 tile-shaped magnets are spliced ​​to form a radial magnetization magnetic ring;

[0028] Fig.14 A front cross-sectional view of a large air-floating micro-vibrator when the main air tank is connected in series with multiple additional air tanks through air pipes;

[0029] Fig.15 Front cross-sectional view of a large air-floating isolator micro-vibrator when the main air tank is connected in series with multiple additional air tanks through throttle holes.

[0030] Explanation of the part numbers in the figure: 1 ground, 2 moving magnetic ring array, 3 moving magnetic ring mounting, 4 fixed magnetic ring array, 5 fixed magnetic ring fixing, 6 load platform, 7 vertical magnetization space negative stiffness array, 8 large air floating micro-vibrator, 9 upper cover, 10 elastic membrane, 11 main gas tank, 12 additional gas tank, 13 compressed gas, 14 throttle hole, 15 air pipe, 16 moving magnetic ring positioning part, 17 fixed magnetic ring positioning part. DETAILED DESCRIPTION

[0031] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0032] High-end instrument equipment heavy-duty precision gas-magnetic composite low-frequency vibration isolation device, using air flotation to stably support loads of tens of tons to thousands of tons, and combined with magnetic levitation technology to produce high negative stiffness characteristics, effectively reduce the vibration isolation stiffness, and achieve low-frequency or even near-zero frequency vibration isolation; it is characterized by: including a load platform 6, a vertically magnetized space negative stiffness array 7 and a large air-floating vibration isolation device 8; the large air-floating vibration isolation device 8 includes an upper cover plate 9, an elastic membrane 10, a main gas tank 11, an additional gas tank 12 and compressed gas 13, the upper cover plate 9 is fixedly connected to the load platform 6, and forms a closed air chamber with the elastic membrane 10 and the main gas tank 11, and compressed gas 13 is introduced into the closed air chamber; the vertically magnetized space negative stiffness array 7 includes a coaxially mounted moving magnetic ring mounting part 3, a moving magnetic ring array 2, a fixed magnetic ring array 4 and a fixed magnetic ring fixing part 5, which are arranged in sequence from the axis along the radius outward, The magnetic ring mounting part 3 is a cylindrical structure with a T-shaped cross-section, the top of which is fixedly connected to the load platform 6, and the bottom maintains a certain gap with the ground 1; the dynamic magnetic ring array 2 is tightly matched and fixedly mounted on the outer side of the dynamic magnetic ring mounting part 3, and the bottom is pressed and fixed by the dynamic magnetic ring positioning part 16; a gap is provided radially between the dynamic magnetic ring array 2 and the fixed magnetic ring array 4 and the fixed magnetic ring fixing part 5, and the fixed magnetic ring fixing part 5 is an annular sleeve with deep grooves arranged along the circumference of the inner side, the bottom of which is fixed, and the top maintains a certain gap with the load platform 6; the fixed magnetic ring array 4 is tightly matched and fixedly mounted in the deep groove on the inner side of the fixed magnetic ring fixing part 5, and the top is pressed and fixed by the fixed magnetic ring positioning part 17; the dynamic magnetic ring array 2 and the fixed magnetic ring array 4 are both composed of 2n+1 layers of equal-section magnetic rings arranged in an axial array and perpendicularly magnetized between adjacent layers, where n≥1, n∈N + ; The heights of the magnetic rings in the same layer in the moving magnetic ring array 2 and the fixed magnetic ring array 4 are equal, and the heights of the magnetic rings in the odd-numbered layers are equal, and the heights of the magnetic rings in the even-numbered layers are equal; on the right half of the front cross-sectional view, the first layer of magnetic rings in the moving magnetic ring array 2 and the fixed magnetic ring array 4 are magnetized in opposite directions in the radial direction, and their bottom surfaces overlap; with each additional layer, the magnetization direction of the moving magnetic ring rotates 90° clockwise, and the magnetization direction of the fixed magnetic ring rotates 90° counterclockwise.

[0033] As a specific implementation, the vertical magnetization space negative stiffness array 7 is arranged in adjacent gaps with the large air-floating isolation micro-vibrator 8 or the vertical magnetization space negative stiffness array 7 is coaxially nested and fixedly installed in the main gas tank 11 of the large air-floating isolation micro-vibrator 8 .

[0034] As a specific implementation, the large air-floating micro-vibrator 8 adopts a steel ring seal, an O-type seal, a diaphragm seal or a pressure self-sealing method.

[0035] As a specific implementation, the pressure of the compressed gas 13 is 0.1 MPa to 0.8 MPa.

[0036] As a specific implementation, the main gas tank 11 is connected in series with a plurality of sealed additional gas tanks 12 via a throttle hole 14 or an air pipe 15 .

[0037] As a specific implementation method, the radially magnetized magnetic rings in the moving magnetic ring array 2 and the fixed magnetic ring array 4 are spliced ​​by multiple tile-shaped magnets that are uniformly magnetized radially. The number of tile-shaped magnets can be 4, 5, 6, 8, 10, 12 and 15, and the gap between adjacent tile-shaped magnets does not exceed 3°.

[0038] As a specific implementation, the moving magnetic ring mounting member 3, the fixed magnetic ring fixing member 5, the moving magnetic ring positioning member 16 and the fixed magnetic ring positioning member 17 are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy metal materials.

[0039] As a specific implementation, the numbers of throttle holes 14 between adjacent additional gas tanks 12 are different and their positions do not overlap.

[0040] As a specific implementation, the throttle hole 14 is in the shape of a triangle, a circle, a five-pointed star or other polygonal shapes.

[0041] Combine the following Figure 1 to Figure 4 An embodiment of the present invention is given.

[0042] The high-end instrument equipment heavy-duty precision air-magnetic composite low-frequency vibration isolation device adopts the parallel combination of magnetic levitation technology and precision air floating system to achieve large load-bearing capacity and low-frequency vibration isolation effect. It consists of a load platform 6, a vertical magnetized space negative stiffness array 7 and a large air floating isolation micro-vibrator 8. The vertical magnetized space negative stiffness array 7 and the large air floating isolation micro-vibrator 8 are arranged in adjacent gaps and support the load platform 6 in parallel. In this vibration isolator, the large air floating isolation micro-vibrator 8 stably supports the load platform 6 of tens to thousands of tons in an air floating manner, and effectively isolates vibrations in the medium and high frequency bands. The vertical magnetized space negative stiffness array 7 uses magnetic levitation to produce high negative stiffness characteristics, and is connected in parallel with the large air floating isolation micro-vibrator 8. Without changing its large load-bearing capacity, the dynamic vibration isolation stiffness is further reduced, especially for low-frequency or even near-zero-frequency vibration interference to achieve efficient isolation. This vibration isolation technology is not only suitable for heavy-load requirements ranging from tens of tons to thousands of tons, but can also significantly reduce the dynamic vibration isolation stiffness without sacrificing the carrying capacity, effectively isolating low-frequency and even near-zero-frequency vibration interference, and providing an "ultra-quiet" working environment for cutting-edge instruments and equipment such as ultra-precision lithography machines, high-resolution satellite cameras, and ultra-precision machine tools, ensuring the stable operation and high-precision measurement of high-end instruments and equipment.

[0043] As the core equipment of ultra-precision air-floating micro-vibration isolation technology, the large-scale air-floating micro-vibration isolation device 8 is a non-metallic spring that fills compressed gas 13 in the elastic membrane 10 and uses the compressibility of the gas to achieve elastic support. In terms of structural design, the upper cover plate 9 is closely connected to the load platform 6 through a fixed connection, and together with the elastic membrane 10 and the main gas tank 11, forms a closed air chamber. This air chamber ensures the stable existence of compressed gas 13 through a variety of advanced sealing technologies such as steel ring sealing, O-type sealing, diaphragm sealing or pressure self-sealing. In this closed air chamber, compressed gas 13 in the range of 0.1MPa to 0.8MPa is filled, providing a stable elastic support force for the vibration isolator. When there is a small vibration disturbance in the outside world, the compressed gas 13 in the large-scale air-floating micro-vibration isolation device 8 will be compressed and expanded accordingly according to the frequency and amplitude of the vibration. This dynamic process not only effectively absorbs the vibration energy, but also converts the vibration energy into heat energy through the dissipation of the gas, thereby achieving a significant vibration isolation effect. By precisely controlling the pressure of the gas in the air chamber, the vibration isolator can stably support high-end instruments and equipment of different qualities, and provide them with good vibration isolation effects in the medium and high frequency bands.

[0044] The vertical magnetization space negative stiffness array 7 includes a moving magnetic ring array 2, a moving magnetic ring mounting part 3, a fixed magnetic ring array 4 and a fixed magnetic ring fixing part 5. The moving magnetic ring array 2 and the fixed magnetic ring array 4 are coaxially nested and arranged from the axis along the radius to the outside. Among them, the moving magnetic ring mounting part 3 is a cylindrical structure with a T-shaped cross-section, the top of which is fixedly connected to the load platform 6, and the bottom maintains a gap of 30mm to 100mm with the ground 1, which is greater than the sum of the floating height of the large air-floating micro-vibrator 8 and the maximum vibration amplitude of the load platform 6. The fixed magnetic ring fixing part 5 is an annular sleeve with a deep groove arranged along the circumference of the inner side surface, the bottom of which is fixed, and the top maintains a gap of 30mm to 100mm with the load platform 6, which is greater than the sum of the floating height of the large air-floating micro-vibrator 8 and the maximum vibration amplitude of the load platform 6. The fixed magnetic ring array 4 is tightly matched and fixedly installed in the deep groove on the inner side of the fixed magnetic ring fixing part 5, and its top is pressed and fixed by the fixed magnetic ring positioning part 17. The moving magnetic ring mounting part 3 and the fixed magnetic ring fixing part 5 are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy. The magnetic rings are all N44H brand Ru-Fe-B permanent magnets with a remanence of 13.54 kGs, an intrinsic coercive force of 12.66 kOe, and a relative magnetic permeability μ r =1.23. The bottom surface of the first layer of moving magnetic rings coincides with that of the first layer of fixed magnetic rings. The first layer of moving magnetic rings is magnetized along the radius toward the axis, and the first layer of fixed magnetic rings is magnetized from the axis toward the radius. On the right half of the front section view, with each additional layer of magnetic rings, the magnetization direction of the moving magnetic rings rotates 90° clockwise, and the magnetization direction of the fixed magnetic rings rotates 90° counterclockwise. The radially magnetized magnetic rings in the moving magnetic ring array 2 and the fixed magnetic ring array 4 are both composed of 8 42° tile-shaped magnets, and the gap between adjacent tile-shaped magnets is 3°.

[0045] Since the number of layers of the moving magnetic ring array 2 and the fixed magnetic ring array 4 satisfies 2n+1 (where n≥1, n∈N +), the entire structure is symmetrical about the n+1th layer of magnetic rings. Therefore, under static conditions, the magnetic forces acting on the moving magnetic ring array 2 cancel each other out and are in a stable equilibrium state. However, when stimulated by a small axial disturbance, relative movement will occur between the moving magnetic ring array 2 and the fixed magnetic ring array 4, which will break the original axial equilibrium state of the moving magnetic ring array 2, while its radial direction remains balanced. During the relative movement, the axial magnetic force exerted by the moving magnetic ring array 2 on the fixed magnetic ring array 4 is consistent with the vibration direction, pushing it further away from the equilibrium position. Once the external force is lost, the system will not be able to recover to its initial equilibrium state by itself. This characteristic makes the vertical magnetization space negative stiffness array 7 exhibit negative stiffness characteristics in the axial direction. When the negative stiffness array is connected in parallel with a large air-floating micro-vibrator 8 to support the load platform 6, it can expand its vibration isolation bandwidth by only generating negative stiffness characteristics without affecting its load of tens of tons to thousands of tons, thereby effectively isolating low-frequency or even near-zero-frequency vibration interference, thereby improving the overall vibration isolation performance. In addition, when the heights of the magnetic rings in the same layer of the moving magnetic ring array 2 and the fixed magnetic ring array 4 are equal, the negative stiffness value of the vertical magnetization space negative stiffness array 7 reaches the maximum. Compared with the negative stiffness configuration formed by the coaxial nesting of radially oppositely magnetized magnetic rings, the negative stiffness value of this configuration can be significantly improved at the same size, with an increase of up to 155 times. Compared with the structure of coaxial nesting of axially same-direction magnetized magnetic rings, its negative stiffness value can also be increased by 21.4 times under the same size.

[0046] Figure 5 and Figure 6 They are respectively a three-dimensional diagram and a front cross-sectional view of the second embodiment of the heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator for high-end instrument equipment, wherein the vertical magnetization space negative stiffness array 7 is coaxially nested and fixedly installed in the main gas tank 11, and supports the load platform 6 in parallel with the large gas-floating isolation micro-vibrator 8, and the dynamic magnetic ring array 2 and the fixed magnetic ring array 4 are coaxially nested and fixedly installed on the dynamic magnetic ring mounting member 3 and the fixed magnetic ring fixing member 5. The top of the dynamic magnetic ring mounting member 3 is fixedly connected to the bottom of the upper cover plate 9, and its bottom maintains a gap of 30mm to 100mm with the upper surface of the lower bottom plate of the main gas tank 11, which is greater than the sum of the floating height of the large gas-floating isolation micro-vibrator 8 and the maximum vibration amplitude of the load platform 6. The bottom of the fixed magnetic ring fixing member 5 is fixedly installed in the main air chamber of the large gas-floating isolation micro-vibrator 8, and is fixedly connected to the upper surface of the lower bottom plate of the main gas tank 11, and its top maintains a gap of 30mm to 100mm with the bottom of the upper cover plate 9.

[0047] The radial magnetization process of the magnetic ring is complicated and the magnetization effect cannot be guaranteed. Therefore, multiple tile-shaped magnets that are uniformly magnetized radially are often spliced ​​together. Figure 7 to Figure 13Schematic diagram of the relative position and magnetization direction of the moving magnetic ring array 2 and the fixed magnetic ring array 4 when 4, 5, 6, 8, 10, 12 and 15 tile-shaped magnets are respectively spliced ​​to form a radial magnetization magnetic ring. The gap between adjacent tile-shaped magnets is usually no more than 3° to ensure the continuity and uniformity of the magnetic field.

[0048] Fig.14 and Fig.15 Two specific embodiments of a large air-floating micro-vibration isolation device 8 are shown. In these two designs, the main gas tank 11 of the large air-floating micro-vibration isolation device 8 is connected in series with m additional gas tanks 12 through an air pipe 15 or a throttle hole 14. The number of throttle holes 14 between adjacent additional gas tanks 12 is different and the positions do not overlap. The two structures are respectively suitable for occasions with larger horizontal or vertical installation spaces. Both the air pipe 15 and the throttle hole 14 play a role in limiting the gas flow rate, so that the heavy-load precision micro-vibration isolation system can respond to external vibrations more stably. By adjusting the diameter or length of the air pipe 15, the number, size and shape of the throttle hole 14, the damping characteristics of the vibration isolation system can be optimized to meet different vibration isolation requirements.

Claims

1. High-end instruments are equipped with heavy-duty precision gas-magnetic composite low-frequency vibration isolation devices, which use air floating to stably support loads of tens to thousands of tons, and combine magnetic levitation technology to produce high negative stiffness characteristics, effectively reduce vibration isolation stiffness, and achieve low-frequency or even near-zero frequency vibration isolation; the characteristics are: The invention comprises a load platform (6), a vertical magnetization space negative stiffness array (7) and a large air-floating micro-vibrator (8); the large air-floating micro-vibrator (8) comprises an upper cover plate (9), an elastic membrane (10), a main gas tank (11), an additional gas tank (12) and compressed gas (13); the upper cover plate (9) is fixedly connected to the load platform (6) and forms a closed air chamber with the elastic membrane (10) and the main gas tank (11); compressed gas (13) is introduced into the closed air chamber; the vertical magnetization space negative stiffness array (7) comprises a moving magnetic ring mounting part (3), a moving magnetic ring array (2), a fixed magnetic ring array (4) and a fixed magnetic ring fixing part (5) which are coaxially mounted and sequentially arranged from the axis along the radius outward; the moving magnetic ring mounting part (3) is a cylindrical structure with a T-shaped cross-section, the top of which is fixedly connected to the load platform (6) and the bottom of which is fixedly connected to the main gas tank (11). The moving magnetic ring array (2) is tightly matched and fixedly mounted on the outer side of the moving magnetic ring mounting member (3), and its bottom is pressed and fixed by a moving magnetic ring positioning member (16); a gap is provided radially between the moving magnetic ring array (2), the fixed magnetic ring array (4), and the fixed magnetic ring fixing member (5); the fixed magnetic ring fixing member (5) is an annular sleeve with a deep groove arranged along the circumference of the inner side, the bottom is fixed, and the top is kept at a certain gap with the load platform (6); the fixed magnetic ring array (4) is tightly matched and fixedly mounted in the deep groove on the inner side of the fixed magnetic ring fixing member (5), and its top is pressed and fixed by a fixed magnetic ring positioning member (17); the moving magnetic ring array (2) and the fixed magnetic ring array (4) are both composed of 2n+1 layers of magnetic rings of equal cross-section arranged in an axial array and perpendicularly magnetized between adjacent layers, wherein n≥1, n∈N + The heights of the same layer of magnetic rings in the moving magnetic ring array (2) and the fixed magnetic ring array (4) are equal, and the heights of the magnetic rings in the odd-numbered layers are equal, and the heights of the magnetic rings in the even-numbered layers are equal; the first layer of magnetic rings in the moving magnetic ring array (2) and the fixed magnetic ring array (4) are magnetized in opposite directions in the radial direction, and their bottom surfaces overlap; on the right half of the front cross-sectional view, with each additional layer, the magnetization direction of the moving magnetic ring rotates 90° clockwise, and the magnetization direction of the fixed magnetic ring rotates 90° counterclockwise.

2. The high-end instrument and equipment heavy-load precision gas-magnetic composite low-frequency isolation micro-vibrator according to claim 1 is characterized by: The vertical magnetization space negative stiffness array (7) and the large air-floating isolation micro-vibrator (8) are arranged in adjacent gaps or the vertical magnetization space negative stiffness array (7) is coaxially nested and fixedly installed in the main gas tank (11) of the large air-floating isolation micro-vibrator (8).

3. The high-end instrument and equipment heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator according to claims 1 and 2 is characterized by: The large air-floating micro-vibrator (8) adopts a steel ring seal, an O-type seal, a diaphragm seal or a pressure self-sealing method.

4. The high-end instrument and equipment heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator according to claims 1 and 3 is characterized by: The pressure of the compressed gas (13) is 0.1 MPa to 0.8 MPa.

5. The high-end instrument and equipment heavy-load precision gas-magnetic composite low-frequency isolation micro-vibrator according to claims 1 to 4, characterized in that: The main gas tank (11) is connected in series with a plurality of sealed additional gas tanks (12) via throttle holes (14) or gas pipes (15).

6. The high-end instrument and equipment heavy-load precision gas-magnetic composite low-frequency isolation micro-vibrator according to claim 1 is characterized by: The radially magnetized magnetic rings in the moving magnetic ring array (2) and the fixed magnetic ring array (4) are formed by splicing a plurality of tile-shaped magnets uniformly magnetized in the radial direction. The number of tile-shaped magnets can be 4, 5, 6, 8, 10, 12 or 15, and the gap between adjacent tile-shaped magnets does not exceed 3°.

7. The high-end instrument and equipment heavy-load precision gas-magnetic composite low-frequency isolation micro-vibrator according to claims 1 and 6 is characterized by: The moving magnetic ring mounting part (3), the fixed magnetic ring fixing part (5), the moving magnetic ring positioning part (16) and the fixed magnetic ring positioning part (17) are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy metal materials.

8. The high-end instrument and equipment heavy-load precision gas-magnetic composite low-frequency isolation micro-vibrator according to claims 1 to 5, characterized in that: The number of throttle holes (14) between adjacent additional gas tanks (12) is different and their positions do not overlap.

9. The high-end instrument and equipment heavy-duty precision gas-magnetic composite low-frequency isolation micro-vibrator according to claims 1 to 5 and 8, characterized in that: The throttle hole (14) is in the shape of a triangle, a circle, a five-pointed star or other polygons.

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