A quasi-zero stiffness vibration isolator based on molecular springs

Abstract

The application provides a quasi-zero stiffness vibration isolator based on a molecular spring, which comprises a piston cylinder, a piston, water and zeolite, the piston is installed inside the piston cylinder, the space formed by the piston and the piston cylinder is filled with water and zeolite, a push rod is vertically connected to the middle of the top of the piston, electromagnets are installed on the left and right sides of the top of the piston and the push rod respectively, permanent magnets are installed vertically above the electromagnets, slide rails are installed on the left and right outer sides of the top of the piston cylinder, slide blocks are installed on the slide rails, locking screws are installed on the outer sides of the slide blocks, vibration isolators are installed on the top of the slide blocks, liquid storage tanks are installed on the outer bottom of the piston cylinder, and sodium chloride solutions are contained in the liquid storage tanks. The system can realize vibration control at 0.2Hz-150Hz, has a wide vibration isolation bandwidth, high positioning accuracy, can be suitable for different types of precision instruments, can bear a maximum load of 2000kg, has a wide application range and high universality.

Description

Technical Field

[0001] This invention relates to the field of semiconductor-specific devices technology, specifically a quasi-zero stiffness vibration isolator based on molecular springs. Background Technology

[0002] The semiconductor industry is developing rapidly, and the precision requirements of semiconductor production equipment are getting higher and higher. The equipment is also becoming more and more sensitive to environmental conditions such as micro-vibration. Even a small amount of micro-vibration can reduce the output yield of the equipment or even cause the equipment to malfunction. Therefore, the isolation of micro-vibration is becoming increasingly important.

[0003] Molecular spring vibration isolation technology is a passive vibration isolation technology based on a novel mechanism. A molecular spring isolator is formed by sealing a molecular spring medium composed of water and porous hydrophobic materials within a piston-hydraulic cylinder. When the molecular spring medium is compressed to a certain pressure, water molecules penetrate the hydrophobic nanopores of the zeolite particles. Upon unloading, the water molecules automatically escape from the micropores. In this process, mechanical energy and surface energy are mutually converted, achieving energy storage and release. Due to the hydrophobicity of the material, water molecules cannot enter the micropores at low pressure. When the pressure reaches a certain critical value, water molecules overcome capillary forces and begin to invade the micropores in large quantities, reducing the stiffness of the molecular spring. Once all micropores are saturated, further pressurization will prevent further water molecule entry. The unloading process is the reverse of this process. Therefore, the molecular spring isolator exhibits segmented stiffness characteristics of high static and low dynamic stiffness, giving it high static load-bearing capacity and low dynamic stiffness. It can not only withstand the weight of the equipment but also has a dynamic stiffness close to zero near the static equilibrium position, making it a relatively ideal quasi-zero stiffness passive vibration isolator. However, most passive quasi-zero stiffness vibration isolators are designed for a single vibration isolation target. Once the isolator is manufactured, the structural parameters cannot be changed. Therefore, when the isolation mass changes, such as under overload or underload, the molecular spring no longer possesses quasi-zero stiffness characteristics, and the vibration isolation performance deteriorates, even falling short of that of linear isolation systems. This significantly limits their application range. A small number of vibration isolators can maintain quasi-zero stiffness characteristics under variable loads, but the isolation mass cannot change continuously. The isolator can only maintain quasi-zero stiffness at a few specific mass points, resulting in a limited range of applications and insufficient positioning accuracy. Summary of the Invention

[0004] The purpose of this invention is to provide a quasi-zero stiffness vibration isolator based on molecular springs to solve the problems existing in the background art.

[0005] The technical solution of this invention is implemented as follows: A quasi-zero stiffness vibration isolator based on molecular springs includes a piston cylinder, a piston, water, and zeolite. The piston is installed inside the piston cylinder, and the space formed by the piston and the piston cylinder is filled with water and zeolite. A push rod is vertically connected to the center of the top of the piston. Electromagnets are respectively installed on the top of the piston and on the left and right sides of the push rod. A permanent magnet is installed vertically above the electromagnets. Metal springs A are respectively installed on the left and right sides of the top of the permanent magnets. The top of the metal springs A is connected to the inner side of the top of the piston cylinder. A pad is installed in the center of the top of the permanent magnet. A set screw passing through the piston cylinder is connected to the pad. Slide rails are respectively installed on the left and right outer sides of the top of the piston cylinder. A slider is installed on the slide rail. A locking screw is installed on the outer side of the slider. A locking screw is installed on the top of the slider. A vibration isolator includes a housing. A voice coil motor is installed on the bottom inner side of the housing. A support plate is installed on the top of the voice coil motor. A support rod passing through the top of the housing is connected to the top of the support plate. A metal spring B is fitted on the outside of the support rod. The top of the metal spring B is connected to the inner top of the housing via an upper pad, and the bottom of the metal spring B is connected to the bottom of the support plate via a lower pad. A top plate is vertically connected to the top of a push rod. The top of the support rod is connected to the bottom of the top plate. A liquid storage tank containing sodium chloride solution is installed on the bottom outer side of a piston cylinder. A conduit connecting the liquid storage tank and the piston cylinder is installed on the top of the liquid storage tank. A hydraulic pump and a check valve are installed on the conduit. An acceleration sensor is also installed on the bottom of the top plate, and a position sensor and a controller are also installed on the top of the piston cylinder.

[0006] Furthermore, the piston cylinder has a cylindrical structure with an internal cavity.

[0007] Furthermore, the push rod is connected to the middle of the bottom of the top plate.

[0008] Furthermore, an upper guide block is installed between the metal spring A and the piston cylinder, and a lower guide block is installed between the metal spring A and the permanent magnet.

[0009] Furthermore, a rubber block is installed between the support rod and the top plate.

[0010] Furthermore, a sealing ring is installed between the outer side of the piston and the piston cylinder.

[0011] Furthermore, the piston cylinder top is provided with an internal thread that is connected to a set screw thread.

[0012] Furthermore, the top of the storage tank is also equipped with a rubber valve, which can be used to allow air to enter when the hydraulic pump is started, and can be removed when filling with sodium chloride solution.

[0013] Furthermore, the controller is connected to the electromagnet, voice coil motor, accelerometer, and position sensor via cables.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention achieves vertical static quasi-zero stiffness of the system by connecting a molecular spring and a magnetic levitation structure in parallel. By adjusting the magnetic moment and current, it can meet the bearing requirements of different loads. For excessively heavy loads, the system's bearing capacity can be further improved by injecting sodium chloride solution to increase the surface tension of the molecular spring liquid, thereby meeting the requirements of heavy loads.

[0016] When the system encounters vibration, the present invention will break the original static quasi-zero stiffness state. During high-frequency vibration, the high-frequency vibration reduction effect is achieved by the parallel connection of the metal spring B and the rubber block; and the low-frequency vibration reduction is achieved by the voice coil motor drive.

[0017] The system of this invention can achieve vibration control from 0.2Hz to 150Hz, with wide vibration isolation bandwidth and precise positioning. It can be adapted to different types of precision instruments, with a maximum load capacity of 2000kg. It has a wide range of applications and strong versatility. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] In the diagram, 1-piston cylinder, 2-piston, 3-push rod, 4-water, 5-zeolite, 6-electromagnet, 7-permanent magnet, 8-pad, 9-set screw, 10-metal spring A, 11-slide rail, 12-slider, 13-locking screw, 14-vibration isolator, 141-housing, 142-voice coil motor, 143-support plate, 144-support rod, 145-metal spring B, 146-upper pad, 147-lower pad, 15-top plate, 16-liquid tank, 17-sodium chloride solution, 18-conduit, 19-hydraulic pump, 20-check valve, 21-upper guide block, 22-lower guide block, 23-rubber block, 24-accelerometer, 25-position sensor, 26-controller, 27-sealing ring, 28-internal thread, 29-rubber valve. Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] like Figure 1As shown, a quasi-zero stiffness vibration isolator based on molecular springs includes a piston cylinder 1, a piston 2, water 4, and zeolite 5. The piston 2 is installed inside the piston cylinder 1, and the space formed by the piston 2 and the piston cylinder 1 is filled with water 4 and zeolite 5. A push rod 3 is vertically connected to the top center of the piston 2. Electromagnets 6 are respectively installed on the top of the piston 2 and on the left and right sides of the push rod 3. A permanent magnet 7 is installed vertically above the electromagnet 6. Metal springs A10 are respectively installed on the left and right sides of the top of the permanent magnet 7. The top of the metal springs A10 is connected to the inner side of the top of the piston cylinder 1. A pad 8 is installed in the middle of the top of the permanent magnet 7. The pad 8 is in contact with a set screw 9 passing through the piston cylinder 1. Slide rails 11 are respectively installed on the left and right outer sides of the top of the piston cylinder 1. A slider 12 is installed on the slide rail 11. A locking screw 13 is installed on the outer side of the slider 12. A vibration isolator 14 is installed on the top of the slider 12. The vibration isolator 14 includes a housing 141. The inner side of the housing 141... A voice coil motor 142 is installed at the bottom, and a support plate 143 is installed on the top of the voice coil motor 142. A support rod 144 passing through the top of the outer shell 141 is connected to the top of the support plate 143. A metal spring B145 is fitted on the outside of the support rod 144. The top of the metal spring B145 is connected to the inside of the top of the outer shell 141 through an upper pad 146, and the bottom of the metal spring B145 is connected to the bottom of the support plate 143 through a lower pad 147. A top plate 15 is vertically connected to the top of the push rod 3. The top of the support rod 144 is connected to the bottom of the top plate 15. A liquid storage tank 16 is installed at the bottom of the outside of the piston cylinder 1. The liquid storage tank 16 contains a sodium chloride solution 17. A conduit 18 connecting the liquid storage tank 16 and the piston cylinder 1 is installed on the top of the liquid storage tank 16. A hydraulic pump 19 and a check valve 20 are installed on the conduit 18. An acceleration sensor 24 is also installed at the bottom of the top plate 15. A position sensor 25 and a controller 26 are also installed on the top of the piston cylinder 1.

[0022] The piston cylinder 1 has a cylindrical structure with an internal cavity.

[0023] The push rod 3 is connected to the middle of the bottom of the top plate 15.

[0024] An upper guide block 21 is also installed between the metal spring A10 and the piston cylinder 1, and a lower guide block 22 is also installed between the metal spring A10 and the permanent magnet 7.

[0025] A rubber block 23 is also installed between the support rod 144 and the top plate 15.

[0026] A sealing ring 27 is also installed between the outer side of the piston 2 and the piston cylinder 1.

[0027] The piston cylinder 1 has an internal thread 28 at the top that is threadedly connected to the set screw 9.

[0028] The top of the storage tank 16 is also equipped with a rubber valve 29, which can be used to allow air to enter when the hydraulic pump 19 is started, and can be removed when filling the sodium chloride solution 17.

[0029] The controller 26 is connected to the electromagnet 6, the voice coil motor 142, the acceleration sensor 24, and the position sensor 25 via cables.

[0030] During installation, the precision instrument is mounted on the top plate 15. The slider 12 is slid down to separate the support rod 144 from the top plate 15. According to the weight requirements of the precision instrument, the magnetic field strength of the electromagnet 6 is controlled by the controller 26, and the magnetic moment is adjusted by the set screw 9 so that the pressure of the piston 2 on the water and zeolite is in the second stage of low stiffness. At this time, the system reaches a near-zero stiffness state in the vertical direction. If the system cannot reach near-zero stiffness through the above adjustment, the hydraulic pump 19 is started to inject sodium chloride solution into the piston cylinder 1 to increase the surface tension of the liquid and improve the load-bearing capacity of the system. Then the slider 12 is slid up so that the support plate 143 contacts the top plate 15, and the slider 1 is fixed by the locking screw 13.

[0031] During operation, the precision instrument generates vibrations. The vibration signals are collected by the accelerometer 24 and the position sensor 25, and then transmitted to the controller 26. For high-frequency vibration sources, high-frequency vibration reduction is achieved through the metal spring B145 and the rubber block 23; for low-frequency vibration sources, low-frequency vibration reduction is achieved through the voice coil motor 142.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A quasi-zero stiffness vibration isolator based on a molecular spring, comprising a piston cylinder, a piston, water, and zeolite, characterized in that, The piston is installed inside the piston cylinder. The space formed by the piston and the piston cylinder is filled with water and zeolite. A push rod is vertically connected to the top center of the piston. Electromagnets are installed on the top of the piston and on both sides of the push rod. A permanent magnet is installed vertically above each electromagnet. Metal springs A are installed on the top left and right sides of the permanent magnet. The top of metal springs A is connected to the inner side of the top of the piston cylinder. An upper guide block is installed between metal springs A and the piston cylinder. A lower guide block is installed between metal springs A and the permanent magnet. A pad is installed in the center of the top of the permanent magnet. The pad is connected to a set screw that passes through the piston cylinder. Slide rails are installed on the left and right outer sides of the top of the piston cylinder. Slider blocks are installed on the slide rails. Locking screws are installed on the outer side of the sliders. A vibration isolator is installed on the top of the slider. The vibration isolator includes a housing. The inner side of the housing... A voice coil motor is installed at the bottom, and a support plate is installed on top of the voice coil motor. A support rod passing through the top of the outer shell is connected to the top of the support plate. A metal spring B is fitted on the outside of the support rod. The top of the metal spring B is connected to the inside of the top of the outer shell through an upper pad, and the bottom of the metal spring B is connected to the bottom of the support plate through a lower pad. A top plate is vertically connected to the top of the push rod, and the top of the support rod is connected to the bottom of the top plate. A liquid storage tank is installed at the bottom outside of the piston cylinder. The liquid storage tank contains a sodium chloride solution. A conduit connecting the liquid storage tank and the piston cylinder is installed on the top of the liquid storage tank. A hydraulic pump and a check valve are installed on the conduit. A rubber valve is also provided on the top of the liquid storage tank. Air can be introduced when the hydraulic pump is started, and it can be removed when filling with sodium chloride solution. An acceleration sensor is also installed at the bottom of the top plate, and a position sensor and a controller are also installed on the top of the piston cylinder.

2. The quasi-zero stiffness vibration isolator based on a molecular spring according to claim 1, characterized in that, The piston cylinder has a cylindrical structure with an internal cavity.

3. A quasi-zero stiffness vibration isolator based on a molecular spring according to claim 1, characterized in that, The push rod is connected to the middle of the bottom of the top plate.

4. A quasi-zero stiffness vibration isolator based on a molecular spring according to claim 1, characterized in that, A rubber block is also installed between the support rod and the top plate.

5. A quasi-zero stiffness vibration isolator based on a molecular spring according to claim 1, characterized in that, A sealing ring is also installed between the outer side of the piston and the piston cylinder.

6. A quasi-zero stiffness vibration isolator based on a molecular spring according to claim 1, characterized in that, The piston cylinder has an internal thread at the top that is connected to a set screw thread.

7. A quasi-zero stiffness vibration isolator based on a molecular spring according to claim 1, characterized in that, The controller is connected to an electromagnet, a voice coil motor, an accelerometer, and a position sensor via cables.

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