A six-degree-of-freedom adjustable integrated quasi-zero stiffness vibration isolator

Abstract

The application provides a six-degree-of-freedom adjustable integrated quasi-zero stiffness vibration isolator, which comprises a buckling beam including a first end and a second end, the first end of the buckling beam is connected to the side of an adapter platform, and the second end of the buckling beam is connected to a base; three or more buckling beams are connected to the side of the adapter platform; a linear spring includes a first end and a second end, the first end of the linear spring is connected to the bottom surface of the adapter platform, and the second end of the linear spring is connected to the base; three or more linear springs are arranged and connected to the bottom surface of the adapter platform; an outer platform arranged above the adapter platform and an adapter body arranged below the adapter platform are connected through a plurality of vertical beams; and the adapter body is hung below the adapter platform through a plurality of flexible cable chains. The application solves the technical problem of a single-degree-of-freedom system limited in the translational direction of the prior art quasi-zero stiffness vibration isolator.

Description

Technical Field

[0001] This application belongs to the field of vibration isolator technology, and specifically relates to a six-degree-of-freedom adjustable integrated quasi-zero stiffness vibration isolator. Background Technology

[0002] In various precision manufacturing fields, such as semiconductor manufacturing and lithography machines, multi-degree-of-freedom vibration isolators are required for high-precision processing. In aerospace equipment and remote sensing satellites, multi-degree-of-freedom vibration isolators are also needed to isolate disturbances from multiple directions in order to prevent vibrations from some vibration sources on the satellite from being transmitted to sensitive electronic devices and thus affecting the actual working state of the satellite.

[0003] However, current research on quasi-zero stiffness vibration isolators mainly focuses on single-degree-of-freedom systems in the translational direction. Summary of the Invention

[0004] This application provides an integrated quasi-zero stiffness vibration isolator with six degrees of freedom adjustable, which can achieve quasi-zero stiffness vibration isolation in six directions.

[0005] Specifically, a six-degree-of-freedom adjustable integrated quasi-zero stiffness vibration isolator includes: Base and adapter platform, and, A buckling beam includes a first end and a second end, wherein the first end of the buckling beam is connected to the side of the transition platform and the second end of the buckling beam is connected to the base; three or more buckling beams are connected to the side of the transition platform. A linear spring includes a first end and a second end. The first end of the linear spring is connected to the bottom surface of the transfer platform, and the second end of the linear spring is connected to the base. Three or more of the linear springs are provided and connected to the bottom surface of the transfer platform. An outer platform is located above the transfer platform and a transfer body is located below the transfer platform. The outer platform and the transfer body are connected by several vertical beams. The adapter is suspended below the adapter platform by several flexible chains; The buckling beam is horizontal by setting the height of the second end of the linear spring according to the device placed on the top surface of the outer platform.

[0006] In one embodiment, the integrated quasi-zero stiffness vibration isolator further includes: A pressure regulating mechanism is used to regulate the axial force of the buckling beam.

[0007] In one embodiment, a pressure regulating mechanism is disposed on the base and includes: A preload bolt is threadedly connected to the adjusting threaded hole, which is located on the base. The stud end of the preload bolt is connected to the second end of the buckling beam.

[0008] In one embodiment, the pressure regulating mechanism further includes: A force sensor is mounted on the end face of the stud end of the preload bolt; A beam-to-cylinder adapter is used to connect the force sensor to the buckling beam.

[0009] In one embodiment, the integrated quasi-zero stiffness vibration isolator further includes: The height adjustment mechanism includes a scissor mechanism and a mounting platform. The lower ends of the two legs of the scissor mechanism are mounted on the base, and the upper ends of the two legs are connected to the mounting platform.

[0010] In one embodiment, the integrated quasi-zero stiffness vibration isolator further includes: a spring position adjustment unit comprising a guide rail located on a mounting platform and a slider sliding within the guide rail, wherein a second end of the linear spring is connected to the slider, and the position of the linear spring is changed by sliding the slider within the guide rail.

[0011] In one embodiment, the two ends of the vertical beam are respectively provided with right-hand and left-hand thread structures, which are respectively connected to the corresponding threaded holes on the outer platform and the adapter.

[0012] In one embodiment, the integrated quasi-zero stiffness vibration isolator further includes a counterweight unit, which is fixedly connected to the outer platform.

[0013] In one embodiment, the base includes four columns, which are respectively disposed on the side of the transition platform; the second end of the buckling beam is connected to the column in the corresponding direction.

[0014] In one embodiment, the adapter platform includes four centrally symmetrical connection ends, each connection end including two first connection ends and a second connection end located between the two first connection ends, the second connection end protruding axially from the first connection end; The first connecting end of the transfer platform is used to connect the buckling beam, and the second connecting end of the transfer platform is used to connect the flexible cable chain.

[0015] In the embodiments of this application, according to the buckling beam theory, when the axial pressure on a slender buckling beam with fixed ends exceeds its first-order buckling critical pressure, the midpoint will exhibit negative stiffness characteristics in the transverse direction. Based on this characteristic, an elastic structure with transverse translational negative stiffness characteristics is proposed.

[0016] The invention concept for a structure with negative stiffness in the torsional direction is as follows: the buckling beams on both sides of the transfer platform are fixed at their ends. When the transfer platform rotates about a certain horizontal axis, the buckling beams parallel to the axis of rotation exhibit a superposition of lateral stiffness and torsional stiffness. When the axial pressure within the buckling beams is large enough, causing the negative stiffness of the lateral displacement to exceed the positive stiffness of the torsional displacement, the transfer platform exhibits negative stiffness when rotating about the horizontal axis.

[0017] Furthermore, in the technical solution of this application, a flexible cable chain is used for connection, which realizes vibration isolation in the horizontal direction and vibration isolation around the vertical direction.

[0018] Compared to existing technologies, this technology solves the technical problem that existing research on quasi-zero stiffness vibration isolators focuses on single-degree-of-freedom systems in the translational direction. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the structure of an integrated quasi-zero stiffness vibration isolator with six degrees of freedom adjustable in Example 1; Figure 2 yes Figure 1 A schematic diagram of the integrated quasi-zero stiffness vibration isolator after removing parts such as the outer platform and the adapter. Figure 3 This is a structural schematic diagram of the outer platform and adapter components described in Embodiment 1; Figure 4 This is a schematic diagram of the pressure regulating mechanism described in Example 1. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] Before providing a detailed description and explanation of the embodiments of this application, some terms, nouns, and technical contents involved in the embodiments of this application will be explained.

[0023] Example 1 Reference Figures 1 to 4 The six-degree-of-freedom adjustable integrated quasi-zero stiffness vibration isolator provided in this embodiment includes: The base and the transfer platform 1, in this embodiment, the base includes a base plate 9 and columns 8 vertically arranged on the base plate 9. A buckling beam 2 includes a first end and a second end. The first end of the buckling beam 2 is connected to the side of the transition platform 1, and the second end of the buckling beam 2 is connected to the column 8. Eight buckling beams 2 are connected to the side of the transition platform 1. The linear spring 4 includes a first end and a second end. The first end of the linear spring 4 is connected to the bottom surface of the transfer platform 1, and the second end of the linear spring 4 is directly connected to the base plate 9 or indirectly connected through other structures. An outer platform 16 is located above the transfer platform 1 and a transfer body 20 is located below the transfer platform 1. The outer platform 16 and the transfer body 20 are connected by four vertical beams 19. The adapter 20 is suspended below the adapter platform 16 by several flexible chains 22; The buckling beam 2 is leveled by adjusting the height of the second end of the linear spring 4 according to the device placed on the top surface of the outer platform 16.

[0024] In the embodiment, according to the buckling beam theory, when the axial pressure on the slender buckling beam 2 with fixed ends exceeds its first-order buckling critical pressure, the midpoint will exhibit negative stiffness characteristics in the transverse direction. Based on this characteristic, an elastic structure with transverse translational negative stiffness characteristics is proposed.

[0025] For the negative stiffness structure in the torsional direction, the approach of this embodiment is as follows: the buckling beam ends on both sides of the transition platform 1 are fixed. When the transition platform 1 rotates around a certain horizontal axis, the buckling beam 2, which is parallel to the axis of rotation, exhibits a superposition of lateral stiffness and torsional stiffness. When the axial pressure within the buckling beam 2 is large enough, causing the negative stiffness of the lateral displacement to be greater than the positive stiffness of the torsional displacement, the transition platform 1 exhibits negative stiffness when rotating around the horizontal axis. In this embodiment, the positive stiffness generated by the linear spring 4 and the negative stiffness generated by the buckling deformation of the buckling beam 2 during operation are provided by the parallel connection of the mechanisms (the linear spring 4 and the buckling beam 2). The positive stiffness mechanism mainly provides static support force, and the negative stiffness mechanism is used to counteract the stiffness of the positive stiffness mechanism, so that the quasi-zero stiffness vibration isolator provided in this embodiment exhibits quasi-zero stiffness characteristics near the steady-state operating point. Therefore, it has low-frequency resonance performance and a large static load-bearing capacity.

[0026] Compared with the prior art, this embodiment achieves both horizontal vibration isolation and vibration isolation around vertical rotation by using a flexible cable chain 22 for connection.

[0027] The quasi-zero stiffness vibration isolator provided in this embodiment can ensure the horizontal working state of the buckling beam 2 and its stability by setting the position of the linear spring 4 in the vertical direction according to the weight of the equipment to be isolated. By adjusting the position of the second end of the buckling beam 2, its negative stiffness can be changed, thereby ensuring that the vertical direction exhibits quasi-zero stiffness characteristics near the steady-state working point.

[0028] In this embodiment, the adapter platform 1 includes four centrally symmetrical connection ends. Each connection end includes two first connection ends 101 and a second connection end 102 located between the two first connection ends. The second connection end 102 protrudes axially from the first connection end 101. The first connecting end 101 of the transfer platform 1 is used to connect the buckling beam 2, and the second connecting end 102 of the transfer platform 1 is used to connect the flexible cable chain 22.

[0029] In this embodiment, eight buckling beams 2 are provided. In other embodiments, fewer buckling beams 2 may be provided, such as three, or more, such as nine. At least three buckling beams 2 can ensure that forces in different directions are applied to the transition platform 1 within the plane of the transition platform 1, and that the position of the transition platform 1 remains stable.

[0030] In this embodiment, four linear springs 4 are provided. In other embodiments, fewer linear springs 4 may be provided, such as three, or more linear springs 4 may be provided, such as six. At least three linear springs 4 can ensure that the transition platform 1 can rotate at any angle relative to the horizontal plane and remain stable.

[0031] The integrated quasi-zero stiffness vibration isolator provided in this embodiment further includes: a pressure adjustment mechanism, which adjusts the axial force of the buckling beam by adjusting the position of the second end of the buckling beam 2. Specifically, the pressure adjustment mechanism is mounted on the column 8 and includes: The preload bolt 10 is threadedly connected to the adjusting threaded hole, which is located on the column 8. The stud end of the preload bolt 10 is connected to the second end of the buckling beam 2.

[0032] By rotating the nut end of the preload bolt 10, its position on the column 8 is changed, thereby changing the position of the second end of the buckling beam 2 and thus changing the stiffness of the buckling beam 2.

[0033] In this embodiment, the stud end of the preload bolt 10 is first connected to the force sensor 11 and the beam adapter cylinder 12. The end face of the beam adapter cylinder 12 can be provided with a threaded hole and is fixed to the second end of the buckling beam 2 by threads. The preload bolt 10 can be tightened along the central axis of the threaded hole and the preload force is transmitted to the buckling beam 2 through the force sensor 11, thereby applying pressure to the buckling beam 2 to bring it into a buckling state.

[0034] Force sensor 11 can monitor the pressure value at the second end of the buckling beam 2 during the rotation of the preload bolt 10, thus monitoring whether the negative stiffness of the buckling beam 2 matches the positive stiffness of the spring by monitoring the pressure on the buckling beam 2. In other embodiments, the displacement of the second end of the buckling beam 2 is monitored, and the negative stiffness of the buckling beam 2 is monitored by the displacement to determine whether it matches the positive stiffness of the spring. In this embodiment, refer to... Figure 1 The upper end of the column 8 is provided with a step near the outer side and a semi-circular groove near the inner side of the upper end face. The step is provided with a threaded hole coaxial with the semi-circular groove. After the preload bolt 10 is screwed into the threaded hole, the force sensor 11, the beam adapter cylinder 12 and the buckling beam 2 are connected, the cover plate 7 is fixed to the column 8 with screws or bolts, and the second end of the buckling beam 2 is pressed to achieve the working state of the second end of the buckling beam 2 being fixed.

[0035] In order to expand the scope of application, the integrated quasi-zero stiffness vibration isolator provided in this embodiment also includes: a height adjustment mechanism, which is installed on the base plate 9 and is used to change the height of the second end of the linear spring 4.

[0036] The height adjustment structure described in this embodiment includes a scissor mechanism 6 and a mounting platform 5. The lower ends of the two legs of the scissor mechanism 6 are mounted on the base plate 9, and the upper ends of the two legs are connected to the mounting platform 5. The second end of the linear spring 4 is mounted on the mounting platform 5.

[0037] By changing the distance between the upper (or lower) ends of the two legs of the scissor mechanism 6, the height of the mounting platform 5 is changed, thereby changing the height of the second end of the linear spring 4.

[0038] This embodiment provides a specific implementation method for adjusting the position between the linear springs 4, see reference. Figure 3 The integrated quasi-zero stiffness vibration isolation device further includes: A spring position adjustment unit, used to adjust the position of each linear spring 4, includes a guide rail 14 located on the mounting platform 5 and a slider 13 sliding within the guide rail 14. The second end of each linear spring 4 is connected to the slider 13. By sliding the slider 13 within the guide rail 14, the position of the linear springs 4 is changed. For a uniformly distributed and regularly shaped object, for example, in the positive direction, the center of gravity of the transfer platform 1 is its geometric center. The guide rail 14 is set relative to this geometric center. Adjusting the position of the linear springs 4 along the guide rail 14 allows for convenient, accurate, and rapid adjustment of the position of each linear spring 4 relative to the center of gravity of the transfer platform 1.

[0039] In this embodiment, a guide post is provided on the upper surface of the slider 13. The guide post is inserted into the spring hole at the second end of the linear spring 4 to minimize the bending deformation of the linear spring 4 during the deformation process.

[0040] In this embodiment, the two ends of the vertical beam 19 are respectively provided with right-hand and left-hand threaded structures, which are respectively connected to the threaded holes of the upper adapter structure 17 and the lower adapter structure 18. The upper adapter structure 17 is connected to the bottom surface of the outer platform, and the lower adapter structure 18 is connected to the top surface of the adapter body 20.

[0041] In this embodiment, a counterweight unit 15 is also provided and connected above the outer platform 16.

[0042] When machining errors cause one of the four vertical beams 19 to be too long or too short, resulting in abnormal load distribution, the mechanism can perform a coarse length adjustment by rotating the beam clockwise or counterclockwise to overcome the impact of machining errors on the system to some extent. The counterweight unit 15 is bolted to the load platform 16, and applies axial pressure to the four vertical beams by applying gravity load, so that the inner subsystem achieves a near-zero stiffness working state in horizontal translation and vertical torsion.

[0043] Before operation, the equipment to be isolated is placed on the outer platform 16. Depending on the weight of the equipment, the linear spring 4 will experience varying degrees of compression. The height of the second end of the linear spring 4 is adjusted according to its compression to ensure that the buckling beam 2 remains horizontal under different load conditions.

[0044] Then, by adjusting the position of the second end of the buckling beam 2, the pressure on the buckling beam 2 is adjusted so that the negative stiffness in the vertical direction generated by the buckling beam 2 matches the positive stiffness in the vertical direction of the linear spring 4.

[0045] Finally, the position of the linear spring 4 is adjusted to adjust the distance between it and the center of gravity of the transition platform 1, so that the positive torsional stiffness provided by the linear spring 4 to the transition platform 1 matches the negative torsional stiffness generated by the buckling beam on the transition platform 1.

[0046] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0047] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0048] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces or units, and may be electrical or other forms.

[0049] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0050] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A six-degree-of-freedom adjustable integrated quasi-zero stiffness vibration isolator, characterized in that, include: Base and adapter platform, and, A buckling beam includes a first end and a second end, wherein the first end of the buckling beam is connected to the side of the transition platform and the second end of the buckling beam is connected to the base; three or more buckling beams are connected to the side of the transition platform. A linear spring includes a first end and a second end. The first end of the linear spring is connected to the bottom surface of the transfer platform, and the second end of the linear spring is connected to the base. Three or more of the linear springs are provided and connected to the bottom surface of the transfer platform. An outer platform is located above the transfer platform and a transfer body is located below the transfer platform. The outer platform and the transfer body are connected by several vertical beams. The adapter is suspended below the adapter platform by several flexible chains; The buckling beam is horizontal by setting the height of the second end of the linear spring according to the device placed on the top surface of the outer platform.

2. The integrated quasi-zero stiffness vibration isolator according to claim 1, characterized in that, Also includes: A pressure regulating mechanism is used to regulate the axial force of the buckling beam.

3. The integrated quasi-zero stiffness vibration isolator according to claim 2, characterized in that, A pressure regulating mechanism, disposed on the base, includes: A preload bolt is threadedly connected to an adjusting threaded hole located on the base. The stud end of the preload bolt is connected to the second end of the buckling beam.

4. The integrated quasi-zero stiffness vibration isolator according to claim 3, characterized in that, The pressure regulating mechanism further includes: A force sensor is mounted on the end face of the stud end of the preload bolt; A beam-to-cylinder adapter is used to connect the force sensor to the buckling beam.

5. The integrated quasi-zero stiffness vibration isolator according to claim 1, characterized in that, Also includes: The height adjustment mechanism includes a scissor mechanism and a mounting platform. The lower ends of the two legs of the scissor mechanism are mounted on the base, and the upper ends of the two legs are connected to the mounting platform.

6. The integrated quasi-zero stiffness vibration isolator according to claim 1, characterized in that, Also includes: A spring position adjustment unit includes a guide rail located on a mounting platform and a slider that slides within the guide rail. The second end of the linear spring is connected to the slider. The position of the linear spring is changed by sliding the slider within the guide rail.

7. The integrated quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The two ends of the vertical beam are respectively provided with right-hand and left-hand thread structures, which are respectively connected to the corresponding threaded holes on the outer platform and the adapter.

8. The integrated quasi-zero stiffness vibration isolator according to claim 1, characterized in that, Also includes: The counterweight unit is fixedly connected to the outer platform.

9. The integrated quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The base includes four columns, which are respectively located on the side of the transition platform; the second end of the buckling beam is connected to the column in the corresponding direction.

10. The integrated quasi-zero stiffness vibration isolator according to claim 9, characterized in that, The adapter platform includes four centrally symmetrical connection ends, each connection end including two first connection ends and a second connection end located between the two first connection ends, the second connection end protruding axially from the first connection end; The first connecting end of the transfer platform is used to connect the buckling beam, and the second connecting end of the transfer platform is used to connect the flexible cable chain.

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