A high-load-bearing multidirectional chiral quasi-zero vibration isolator based on chiral twist design

Abstract

The present invention discloses a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on a chiral torsion design, comprising a base and a chiral torsion buckling unit; the chiral torsion buckling unit comprises a mounting part, a rotating part and a plurality of elastic elements, the rotating part is rotatably connected to the base, the mounting part is coaxially arranged above the rotating part, and the elastic elements are connected between the mounting part and the rotating part at periodic intervals along the circumferential direction; when the chiral torsion buckling unit has no external load, the elastic elements are in an inclined state. The chiral torsion buckling unit will undergo chiral torsion deformation under the action of an external compressive load, generating a buckling platform stress, i.e., a quasi-zero stiffness stage with a dynamic stiffness close to 0. A positive stiffness spring can also be connected in parallel to the chiral torsion buckling to avoid instability caused by torsion and enhance the overall load-bearing capacity. In addition, the vibration isolator has low tangential stiffness, realizes multi-directional low-frequency quasi-zero vibration isolation, and has a compact structure, which effectively solves the problem that the quasi-zero stiffness vibration isolator has low load-bearing capacity and can only act in one direction.

Description

Technical Field

[0001] The present invention relates to the fields of mechanical engineering, aerospace, shipbuilding and oceanography, vibration and noise control, and metamaterial structure technology. Specifically, the invention relates to a high-load-bearing multidirectional chiral quasi-zero vibration isolator based on a chiral twist design. The device is used to achieve multidirectional ultra-low-frequency quasi-zero stiffness vibration isolation under heavy loads, that is, to achieve high static stiffness, low dynamic stiffness, and high-load-bearing vibration isolation in both the vertical and shear directions. Background Art

[0002] Structural vibration in mechanical equipment can cause fatigue fracture of components, reduce system control accuracy and stability, and radiate noise, reducing passenger comfort in aircraft and high-speed trains. Furthermore, acoustic radiation from vibration can limit the equipment's acoustic stealth performance. Vibration isolators are key components for addressing vibration in complex systems. According to isolator design theory, the lower the dynamic stiffness (i.e., the lower the installed natural frequency), the better the low-frequency, broadband vibration isolation performance. Quasi-zero-stiffness isolators, characterized by high static stiffness and low dynamic stiffness, can reduce natural frequencies below 3 Hz and are attracting widespread attention. Their implementation requires nonlinear deformation of the entire structure.

[0003] Conventional quasi-zero stiffness isolators in the existing technology are basically implemented using structures such as buckling springs, buckling beams / plates / shells, X-shaped folding structures, cams, and magnetic springs. In essence, they use the bending buckling of the structure to generate negative stiffness. They have complex structures, low load-bearing capacity, and high tangential stiffness. New methods are urgently needed to overcome the above technical difficulties. Summary of the Invention

[0004] In response to the above-mentioned deficiencies in the prior art, the present invention provides a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design, which can achieve vertical and tangential vibration isolation frequencies below 3Hz while greatly improving the load-bearing capacity per unit volume.

[0005] To achieve the above objectives, the present invention provides a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design, comprising a base and a chiral rotation-torsion buckling unit;

[0006] The chiral torsional buckling unit includes a mounting member, a rotating member, and a plurality of elastic elements. The rotating member is rotatably connected to the base, and the rotating axis of the rotating member coincides with the central axis of the vibration isolator.

[0007] The mounting member is coaxially arranged above the rotating member, and the elastic elements are connected between the mounting member and the rotating member at intervals along the circumferential direction;

[0008] When the chiral torsional buckling unit has no external load, each of the elastic elements is in an inclined state, and the inclination direction and inclination angle of each of the elastic elements are the same.

[0009] In one embodiment, the high-load multi-directional chiral quasi-zero vibration isolator based on chiral twist design further includes a balancing spring;

[0010] One end of the balance spring is fixedly connected to the rotating member, and the other end is connected to the mounting member, and the axis of the balance spring coincides with the central axis of the vibration isolator.

[0011] In one embodiment, the first end of the elastic element is fixedly connected to the rotating member, and the distance between the center of the first end of the elastic element and the central axis of the vibration isolator is R1;

[0012] The second end of the elastic element is fixedly connected to the mounting member, and the distance between the center of the second end of the elastic element and the central axis of the vibration isolator is R2;

[0013] Wherein, R1=R2=R, and R is the installation pitch radius of the elastic element between the installation member and the rotating member.

[0014] In one embodiment, the distance between the mounting member and the rotating member is h0, and h0≈4R~5R.

[0015] In one embodiment, the elastic element is a cylindrical structure capable of withstanding bending and torsional deformation.

[0016] In one embodiment, the distance between two adjacent elastic elements is greater than or equal to the diameter of the elastic element.

[0017] In one embodiment, the base includes a bottom plate and a shell;

[0018] The housing is detachably connected to the bottom plate, a placement cavity is formed between the housing and the bottom plate, and an opening communicating with the placement cavity is provided on the top of the housing;

[0019] The rotating member is a rotating body structure with a convex cross-section, the bottom end of the rotating member is located in the placement cavity and is rotatably engaged with the bottom plate and the housing, and the top end of the rotating member is located in the opening and is rotatably engaged with the opening;

[0020] The elastic element is connected to the top end of the rotating member.

[0021] In one embodiment, it further includes an end bearing;

[0022] A sink groove is formed at the bottom end of the rotating member, the first end of the end bearing is fixedly embedded in the sink groove, and the second end of the end bearing is fixedly connected to the bottom plate.

[0023] In one embodiment, an annular groove is formed on the convex step surface of the rotating member, a plurality of balls are disposed in the annular groove, and the balls are in rolling engagement with the inner wall of the housing.

[0024] In one embodiment, there are a plurality of chiral torsional buckling units, and each of the chiral torsional buckling units is distributed in an array on the substrate.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] 1. The high-load-bearing multi-directional chiral quasi-zero vibration isolator of the present invention responds to lateral bending deformation of the elastic element when subjected to shear deformation. Its overall tangential stiffness is low, achieving multi-directional, low-frequency, quasi-zero vibration isolation. Its compact structure effectively addresses the challenges of quasi-zero stiffness isolators, which suffer from low load-bearing capacity and unidirectional action.

[0027] 2. The high-load-bearing multi-directional chiral quasi-zero vibration isolator of the present invention makes the vertical and 360-degree tangential vibration isolation frequencies lower than 3Hz, effectively achieving multi-directional quasi-zero performance, and its load-bearing capacity per unit volume is significantly better than that of existing technologies;

[0028] 3. The high-load-bearing multi-directional chiral quasi-zero vibration isolator of the present invention can be made of all-metal materials and has high environmental adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0030] Figure 1 is an axonometric diagram of a chiral vibration isolator according to an embodiment of the present invention;

[0031] Figure 2 is a cross-sectional view of a chiral vibration isolator according to an embodiment of the present invention;

[0032] Figure 3 is an axonometric diagram of a chiral torsional buckling unit according to an embodiment of the present invention;

[0033] Figure 4 FIG1 is a buckling deformation diagram of the chiral torsional buckling unit under compression load in an embodiment of the present invention;

[0034] Figure 5 is a compression displacement-load curve diagram of the chiral vibration isolator in an embodiment of the present invention;

[0035] Figure 6An axonometric view of a chiral torsional buckling unit with a balancing spring in an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of a large-scale quasi-zero stiffness vibration isolator in an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of an experiment in an embodiment of the present invention, wherein: Figure 8 (a) Schematic diagram of the chiral isolator during the experiment; Figure 8 (b) is the experimentally measured vibration isolation curve of the chiral vibration isolator under different loads;

[0038] Figure 9 Schematic diagram comparing the chiral vibration isolator in an embodiment of the present invention and the existing quasi-zero stiffness vibration isolator.

[0039] Reference numerals: mounting part 1, rotating part 2, elastic element 3, balancing spring 4, base plate 5, housing 6, end bearing 7, ball 8.

[0040] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0043] like Figure 1 The figure shows a high-load-bearing multi-directional chiral quasi-zero vibration isolator (hereinafter referred to as "chiral vibration isolator") based on chiral twisting design disclosed in this embodiment, which mainly includes a base and a chiral rotation-torsion buckling unit.

[0044] refer to Figure 2 、 Figure 3, the chiral torsional buckling unit is cylindrical as a whole, and its axis coincides with the central axis of the chiral vibration isolator. Specifically, the chiral torsional buckling unit includes a mounting part 1, a rotating part 2 and a plurality of elastic elements 3. The rotating part 2 is rotatably connected to the base, and the rotating axis of the rotating part 2 coincides with the central axis of the chiral vibration isolator. The mounting part 1 is coaxially arranged above the rotating part 2, and each elastic element 3 is connected between the mounting part 1 and the rotating part 2 at intervals along the circumferential direction. When the chiral torsional buckling unit has no external load, there is an initial relative helical angle α0 that is not equal to 0, that is, each elastic element 3 is in a tilted state, and the tilt direction and tilt angle of each elastic element 3 are the same, thereby forming a chiral characteristic. Among them,

[0045] In this embodiment, when the rotating member 2 has only rotational freedom, but the vertical deformation is limited, and the rotation of the mounting member 1 is limited, when the mounting member 1 is compressed, the entire chiral torsional buckling unit will gradually compress and cause the rotating member 2 at the bottom to rotate. In addition, the elastic element 3 will produce structural buckling under the action of a large compressive load, forming Figure 4 The chiral torsional buckling deformation shown constitutes the plateau segment in the displacement-load curve, e.g. Figure 5 Chiral torsional buckling deformation will produce negative stiffness and zero stiffness. When the load reaches the platform load, the dynamic stiffness will approach 0, thus producing a quasi-zero stiffness characteristic of high static stiffness and low dynamic stiffness.

[0046] In order to avoid the instability caused by the negative stiffness of the chiral torsional buckling, this embodiment preferably embeds a balancing spring 4 in the chiral torsional buckling unit. Figure 6 As shown, one end of the balancing spring 4 is fixedly connected to the rotating member 2, and the other end is connected to the mounting member 1. The axis of the balancing spring 4 coincides with the central axis of the chiral isolator, that is, the balancing spring 4 and the elastic element 3 are connected in parallel. By connecting the balancing spring 4 in parallel, the load-bearing capacity of the entire chiral isolator can be increased by over 20%. Furthermore, by appropriately selecting the stiffness of the balancing spring 4, the compression buckling of the chiral isolator can be brought close to horizontal, achieving a state of zero dynamic stiffness.

[0047] In a specific implementation, the first end of the elastic element 3 is fixedly connected to the rotating member 2 by gluing, snap-fitting, screwing, welding, or other methods, with the center of the first end of the elastic element 3 and the central axis of the chiral isolator being spaced apart by a distance R1. The second end of the elastic element 3 is fixedly connected to the mounting member 1 by gluing, snap-fitting, screwing, welding, or other methods, with the center of the second end of the elastic element 3 and the central axis of the chiral isolator being spaced apart by a distance R2. A chiral isolator with a parameter of R1≠R2 performs worse than one with a parameter of R1=R2. Therefore, in this embodiment, R1=R2=R is preferably selected, where R is the radius of the installation pitch circle of the elastic element 3 between the mounting member 1 and the rotating member 2.

[0048] Assuming the spacing between the mounting member 1 and the rotating member 2 is h0 when the chiral torsion-torsion buckling unit is free of external load, for a given spacing h0 and overall buckling strain, reducing the mounting pitch radius R and the initial relative helical angle α0 can improve the bearing strength of the chiral torsion-torsion buckling unit, with the performance improvement brought about by reducing R being more significant. Therefore, to ensure overall structural stability, in this embodiment, the spacing between the mounting member 1 and the rotating member 2 is preferably set to h0 ≈ 4R - 6R, for example, h0 = 40 mm and R = 7.5 mm.

[0049] In this embodiment, the elastic element 3 is a cylindrical structure capable of withstanding buckling and torsional deformation, such as a rubber rod or metal spring. Furthermore, to ensure that the deformed elastic elements 3 of the chiral torsional buckling unit do not contact each other before the structure collapses, the spacing between two adjacent elastic elements 3 is set to be greater than or equal to the diameter of the elastic element 3.

[0050] In a specific implementation, the base comprises a bottom plate 5 and a housing 6. Specifically, the housing 6 is removably connected to the bottom plate 5 via bolts, snap-fit ​​connections, or other means. A housing cavity is defined between the housing 6 and the bottom plate 5, and an opening is provided at the top of the housing 6, communicating with the housing cavity. The rotating member 2 is a rotatable structure with a convex cross-section. The bottom end of the rotating member 2 is located within the housing cavity and rotates with the bottom plate 5 and housing 6. The top end of the rotating member 2 is located within the opening and rotates with it. The elastic element 3 is connected to the top end of the rotating member 2.

[0051] To ensure frictionless rotation of the rotating member 2 during actual use, a coaxial circular groove is formed within the rotating member 2. An end bearing 7 is also installed. The first end of the end bearing 7 is embedded in the groove and fixedly connected to the groove wall through gluing, interference fit, or other methods. The second end of the end bearing 7 is fixedly connected to the base plate 5 through gluing, etc. Simultaneously, a smooth annular groove is hollowed out along the convex step edge of the rotating member 2, and a number of balls 8 are placed within the annular groove. When the housing 6 is mounted on the base plate 5, the inner top wall of the housing 6 contacts the balls 8, forming a rolling fit, thereby preventing the chiral isolator from detaching under tension. External loads can be attached to the mounting member 1 using fasteners such as screws.

[0052] As a preferred embodiment, the number of chiral torsional buckling units can be multiple, and each chiral torsional buckling unit can be distributed in an array on the substrate, or multiple chiral isolators can be directly arrayed to form a larger-scale quasi-zero stiffness isolator to improve the overall bearing capacity, for example Figure 7 shown.

[0053] The following is a further explanation of the chiral vibration isolator in this embodiment in conjunction with specific experimental tests. In the test, the initial parameters of the chiral torsional buckling unit are h0=30mm, R=7.5mm, α0=5°, and the elastic element 3 is a steel spring with an outer diameter of 6mm and an inner diameter of 3.2mm. Figure 8 As shown, the cubic dimensions of a single chiral isolator are 25×25×38 mm. 3 .like Figure 5 As shown in FIG, a single chiral isolator enters a buckling state with a dynamic stiffness close to 0 when the compression load is around 27 kg.

[0054] like Figure 8 As shown in Figure 1, loads of varying weights were installed on the chiral isolator and its vibration transmissibility was tested. The experimental results show that the resonant frequency of the chiral isolator gradually decreases with increasing load, reaching its lowest state when the load reaches approximately 27 kg. The measured natural frequency is below 2 Hz.

[0055] like Figure 9 As shown, by comparing various quasi-zero stiffness isolators in existing public literature with the chiral vibration isolator in this embodiment, it can be seen that the chiral quasi-zero stiffness isolator in this embodiment may increase the load-bearing capacity per unit volume by more than 100 times compared with existing public solutions, and by more than 1,000 times compared with the current average level.

[0056] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A high-load multi-directional chiral quasi-zero vibration isolator based on chiral twist design, characterized in that: Includes base and chiral torsional buckling elements; The chiral torsional buckling unit includes a mounting member, a rotating member, and a plurality of elastic elements. The rotating member is rotatably connected to the base, and the rotating axis of the rotating member coincides with the central axis of the vibration isolator. The mounting member is coaxially arranged above the rotating member, and the elastic elements are connected between the mounting member and the rotating member at intervals along the circumferential direction; When the chiral torsional buckling unit has no external load, each of the elastic elements is in an inclined state, and the inclination direction and inclination angle of each of the elastic elements are the same.

2. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 is characterized in that: Also includes a balance spring; One end of the balance spring is fixedly connected to the rotating member, and the other end is connected to the mounting member, and the axis of the balance spring coincides with the central axis of the vibration isolator.

3. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: The first end of the elastic element is fixedly connected to the rotating member, and the distance between the center of the first end of the elastic element and the central axis of the vibration isolator is R1; The second end of the elastic element is fixedly connected to the mounting member, and the distance between the center of the second end of the elastic element and the central axis of the vibration isolator is R2; Wherein, R1=R2=R, and R is the installation pitch radius of the elastic element between the installation member and the rotating member.

4. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 3 is characterized in that: The distance between the mounting member and the rotating member is h0, and h0≈4R~6R.

5. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: The elastic element is a cylindrical structure capable of bearing bending and torsional deformation.

6. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 5, characterized in that: The distance between two adjacent elastic elements is greater than or equal to the diameter of the elastic element.

7. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: The base includes a bottom plate and a shell; The housing is detachably connected to the bottom plate, a placement cavity is formed between the housing and the bottom plate, and an opening communicating with the placement cavity is provided on the top of the housing; The rotating member is a rotating body structure with a convex cross-section, the bottom end of the rotating member is located in the placement cavity and is rotatably engaged with the bottom plate and the housing, and the top end of the rotating member is located in the opening and is rotatably engaged with the opening; The elastic element is connected to the top end of the rotating member.

8. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 7, characterized in that: Also included are end bearings; A sink groove is formed at the bottom end of the rotating member, the first end of the end bearing is fixedly embedded in the sink groove, and the second end of the end bearing is fixedly connected to the bottom plate.

9. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 7, characterized in that: An annular groove is provided on the convex step surface of the rotating member. A plurality of balls are provided in the annular groove, and the balls are in rolling engagement with the inner wall of the outer shell.

10. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: There are multiple chiral torsional buckling units, and each chiral torsional buckling unit is distributed in an array on the substrate.

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