A bidirectional horizontal quasi-zero stiffness vibration isolator

Abstract

The application discloses a bidirectional horizontal quasi-zero stiffness vibration isolator and relates to the technical field of vibration reduction devices. The bidirectional horizontal quasi-zero stiffness vibration isolator comprises a bottom plate, a top plate, an intermediate plate, a vibration isolation mechanism and the like. The bottom plate is used for being mounted on a vibration source. The top plate is arranged above the bottom plate and is used for bearing a load. The intermediate plate is arranged between the bottom plate and the top plate. The top plate is configured to be movable along a first horizontal direction relative to the intermediate plate. The intermediate plate is configured to be movable along a second horizontal direction relative to the bottom plate. The second horizontal direction is orthogonal to the first horizontal direction. The vibration isolation mechanism is arranged between the bottom plate and the top plate and is used for making the equivalent dynamic stiffness in the first horizontal direction and the second horizontal direction approach to zero near a balance position. The vibration isolation mechanism comprises a positive stiffness element and a negative stiffness mechanism. The bidirectional horizontal quasi-zero stiffness vibration isolator can bear the load stably by means of the positive stiffness element in a static state. The bidirectional horizontal quasi-zero stiffness vibration isolator exhibits extremely low dynamic stiffness in a dynamic slight vibration state, so that low-frequency vibration can be effectively isolated.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction device technology, and in particular to a bidirectional horizontal quasi-zero stiffness vibration isolator. Background Technology

[0002] In high-end applications such as precision instruments, optical platforms, and vehicle-mounted and shipborne equipment, horizontal micro-vibration control has become a key bottleneck determining the performance limits of the system. As precision manufacturing advances to the nanoscale and scientific exploration moves towards extreme sensitivity, equipment is becoming increasingly sensitive to low-frequency horizontal vibrations in the 0.5-10Hz frequency range. These vibrations originate from environmental factors such as long-period ground fluctuations and building swaying, as well as from the movement and impacts of the mobile platform itself. Achieving effective bidirectional horizontal vibration isolation is a technical requirement for improving the accuracy and stability of equipment.

[0003] However, traditional vibration isolation technologies reveal fundamental limitations in the face of this challenge. Traditional metal springs and rubber isolators are constrained by the contradiction between high static stiffness and low dynamic stiffness: to maintain the stability of equipment under horizontal impact, higher stiffness must be used, making it difficult to reduce the system's natural frequency below 5Hz, which completely fails to meet the vibration isolation requirements of precision equipment in the critical low-frequency range of 1-10Hz. While structures based on the pendulum principle or leaf spring guidance can achieve lower natural frequencies, this often comes at the cost of sacrificing space efficiency and decoupling performance. Furthermore, their linear stiffness characteristics mean that further frequency reduction will inevitably lead to a sharp increase in structural size and a deterioration in anti-interference capabilities.

[0004] In recent years, quasi-zero stiffness technology has created extremely low equivalent dynamic stiffness near the equilibrium point through a parallel mechanism of positive and negative stiffness, providing a new approach to breaking through the bottleneck of low-frequency vibration isolation. However, existing quasi-zero stiffness designs mostly rely on vertical gravity preloading or complex aero-electromagnetic systems. When transplanted to horizontal bidirectional working conditions, they generally suffer from problems such as the inability of negative stiffness mechanisms to self-stabilize, strong bidirectional dynamic coupling, and significant effects of frictional nonlinearity. This leads to a narrowing of the actual vibration isolation bandwidth and a degradation of low-frequency performance. Especially when facing variable load conditions such as vehicle-mounted and ship-mounted applications, existing solutions often exhibit defects such as stiffness characteristic drift and inaccurate zero-stiffness point, which seriously restricts their practical application value in the field of high-end equipment.

[0005] Therefore, there are still shortcomings and deficiencies in the existing technology, and there is an urgent need to develop a bidirectional horizontal quasi-zero stiffness vibration isolator that can integrate high load-bearing capacity and quasi-zero stiffness characteristics in a limited space. Summary of the Invention

[0006] The purpose of this invention is to provide a bidirectional horizontal quasi-zero stiffness vibration isolator, which solves the technical problems that traditional vibration isolation technology and current quasi-zero stiffness technology have many defects and cannot meet the requirements.

[0007] To achieve the above objectives, the present invention provides a bidirectional horizontal quasi-zero stiffness vibration isolator, comprising:

[0008] Base plate, used for mounting to the vibration source;

[0009] A top plate, located above the bottom plate, is used to bear the load;

[0010] An intermediate plate is disposed between the bottom plate and the top plate; the top plate is configured to move relative to the intermediate plate along a first horizontal direction, and the intermediate plate is configured to move relative to the bottom plate along a second horizontal direction, the second horizontal direction being orthogonal to the first horizontal direction;

[0011] A vibration isolation mechanism is disposed between the bottom plate and the top plate, and is used to make the equivalent dynamic stiffness in the first horizontal direction and the second horizontal direction approach zero near the equilibrium position. The vibration isolation mechanism includes a positive stiffness element and a negative stiffness mechanism.

[0012] In some technical solutions, the top of the intermediate plate is provided with multiple sets of first guide components. Each first guide component includes two spaced-apart first locking blocks, and a first guide rod arranged along a first horizontal direction is fixedly connected between the two first locking blocks. The bottom of the top plate is provided with multiple first fixing blocks, and the first fixing blocks are slidably connected to the first guide rods.

[0013] In some technical solutions, the top of the base plate is provided with multiple sets of second guide components, each of which includes two spaced-apart second locking blocks and a second guide rod fixedly connected between the two second locking blocks along a second horizontal direction; the bottom of the intermediate plate is provided with multiple second fixing blocks, which are slidably connected to the second guide rods.

[0014] In some technical solutions, the positive stiffness element includes a first positive stiffness spring sleeved on the first guide rod and located between the first fixing block and the first locking block, and a second positive stiffness spring sleeved on the second guide rod and located between the second fixing block and the second locking block.

[0015] In some technical solutions, the first locking block is provided with a first through hole, the first guide rod passes through the first locking block through the first through hole, and the two ends of the first guide rod are threaded with first nuts. The first guide rod is limited and fixed between the two first locking blocks by the two first nuts; and / or, the second locking block is provided with a second through hole, the second guide rod passes through the second locking block through the second through hole, and the two ends of the second guide rod are threaded with second nuts. The second guide rod is limited and fixed between the two second locking blocks by the two second nuts.

[0016] In some technical solutions, the negative stiffness mechanism includes:

[0017] A cam is fixedly mounted on the bottom of one of two adjacent plates that can move relative to each other.

[0018] The follower is located on top of the other of two adjacent plate layers that are relatively stationary, and contacts the profile surface of the cam.

[0019] An elastic element, connected between the follower and one of the two relatively stationary plates, is used to apply a preload force to the follower to press it against the profile surface of the cam.

[0020] In some technical solutions, the driven member is a roller, which is rotatably mounted on a bracket, and one end of the elastic element is connected to the bracket.

[0021] In some technical solutions, the other end of the elastic element is provided with an adjustment member, which is detachably fixed to the top of the relatively stationary plate layer in two adjacent plate layers, and is used to adjust the initial preload of the elastic element.

[0022] In some technical solutions, the number of elastic elements in a set of negative stiffness mechanisms between two adjacent plates is two, and the two elastic elements are symmetrically distributed on both sides of the cam.

[0023] In some technical solutions, the elastic element is a helical spring.

[0024] Compared to the aforementioned background technology, the bidirectional horizontal quasi-zero stiffness vibration isolator provided by this invention has an isolation mechanism disposed between the base plate and the top plate. Through positive stiffness elements and negative stiffness mechanisms, the positive and negative stiffness can cancel each other out near the equilibrium position, achieving an equivalent dynamic stiffness approaching zero in both the first and second horizontal directions, i.e., quasi-zero stiffness characteristics. This allows the isolator to stably bear the load (high static stiffness) in a static state relying on the positive stiffness elements, while exhibiting extremely low dynamic stiffness during dynamic minor vibrations, thus effectively isolating low-frequency vibrations. The structure adopts a fully mechanical design, requiring no external energy input, gravity preload, or complex control system. It is structurally reliable, highly adaptable to the environment, and suitable for various horizontal vibration isolation scenarios lacking constant preload conditions, such as aerospace, precision instruments, and automotive equipment. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the bidirectional horizontal quasi-zero stiffness vibration isolator provided in an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the structure of the base plate provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the top plate provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the intermediate plate provided in an embodiment of the present invention;

[0030] Figure 5 This is a top view of the bidirectional horizontal quasi-zero stiffness vibration isolator provided in an embodiment of the present invention after the top plate has been removed.

[0031] Figure 6 This is a schematic diagram of the structure of the second guide rod provided in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the negative stiffness mechanism provided in an embodiment of the present invention;

[0033] Figure 8 This is a partial structural schematic diagram of the negative stiffness mechanism provided in an embodiment of the present invention.

[0034] Figures 1 to 8 Reference numerals in the attached drawings: 1. Base plate; 11. Second guide assembly; 111. Second locking block; 112. Second guide rod; 113. Second nut; 2. Top plate; 21. First fixing block; 3. Intermediate plate; 31. First guide assembly; 311. First locking block; 312. First guide rod; 313. First nut; 32. Second fixing block; 4. First positive stiffness spring; 5. Second positive stiffness spring; 6. Negative stiffness mechanism; 61. Cam; 62. Elastic element; 63. Roller; 64. Bracket; 65. Adjusting component. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Please refer to this as well. Figures 1 to 8This invention provides a bidirectional horizontal quasi-zero stiffness vibration isolator. The bidirectional horizontal quasi-zero stiffness vibration isolator provided by this invention includes:

[0038] Base plate 1, used for mounting to the vibration source;

[0039] Top plate 2, located above bottom plate 1, is used to bear the load;

[0040] An intermediate plate 3 is disposed between a bottom plate 1 and a top plate 2; the top plate 2 is configured to move relative to the intermediate plate 3 along a first horizontal direction, and the intermediate plate 3 is configured to move relative to the bottom plate 1 along a second horizontal direction, the second horizontal direction being orthogonal to the first horizontal direction.

[0041] The vibration isolation mechanism is located between the bottom plate 1 and the top plate 2. It is used to make the equivalent dynamic stiffness in the first horizontal direction and the second horizontal direction approach zero near the equilibrium position. The vibration isolation mechanism includes a positive stiffness element and a negative stiffness mechanism 6.

[0042] The bidirectional horizontal quasi-zero stiffness vibration isolator provided in this embodiment adopts a three-layer plate stacked structure, including a base plate 1, a top plate 2, and an intermediate plate 3 located between the two. The base plate 1 serves as the base of the entire vibration isolator and can be installed on the vibration source (such as the ground, vehicle body, ship deck, etc.) to receive vibration input from the outside. The top plate 2 is located above the base plate 1, and its top surface serves as a load mounting platform to support precision equipment or instruments that require vibration isolation.

[0043] The top plate 2 is configured to move relative to the intermediate plate 3 along a first horizontal direction; the intermediate plate 3 is configured to move relative to the bottom plate 1 along a second horizontal direction, and the second horizontal direction is orthogonal to the first horizontal direction. This orthogonal arrangement completely decouples the movements in the first and second horizontal directions, preventing them from interfering with each other, thus laying the mechanical foundation for bidirectional independent vibration isolation.

[0044] The vibration isolation mechanism is located between the base plate 1 and the top plate 2, and specifically includes a positive stiffness element and a negative stiffness mechanism 6. Through the positive stiffness element and the negative stiffness mechanism 6, the positive and negative stiffness can cancel each other out near the equilibrium position, achieving an equivalent dynamic stiffness approaching zero in both the first and second horizontal directions—a quasi-zero stiffness characteristic. This allows the vibration isolator to stably bear the load (high static stiffness) in a static state using the positive stiffness element, while exhibiting extremely low dynamic stiffness during small dynamic vibrations, thus effectively isolating low-frequency vibrations. The vibration isolator adopts a fully mechanical structure, requiring no external energy input, gravity preload, or complex control system. It is structurally reliable, highly adaptable to various environments, and suitable for horizontal vibration isolation scenarios lacking constant preload conditions, such as aerospace, precision instruments, and automotive equipment.

[0045] In some embodiments, the top of the intermediate plate 3 is provided with a plurality of first guide components 31, each first guide component 31 including two spaced first locking blocks 311, and a first guide rod 312 arranged along a first horizontal direction is fixedly connected between the two first locking blocks 311; the bottom of the top plate 2 is provided with a plurality of first fixing blocks 21, and the first fixing blocks 21 are slidably connected to the first guide rods 312.

[0046] Please refer to this as well. Figures 1 to 8 To ensure smooth guidance of the top plate 2 relative to the intermediate plate 3 along the first horizontal direction, this embodiment provides multiple sets of first guide components 31 on the top of the intermediate plate 3. Each set of first guide components 31 includes two spaced-apart first locking blocks 311, which are fixedly mounted on the top surface of the intermediate plate 3, maintaining a certain distance between them. A first guide rod 312 is fixedly connected between the two first locking blocks 311, and the axis of the first guide rod 312 is set along the first horizontal direction.

[0047] Multiple first fixing blocks 21 are fixedly installed at the bottom of the top plate 2. The number of first fixing blocks 21 matches the number of sets of first guide components 31, and their positions correspond one-to-one. Each first fixing block 21 has a guide hole, through which the first fixing block 21 is sleeved onto the first guide rod 312 and slidably connected with the first guide rod 312. When the top plate 2 is subjected to a force in the first horizontal direction, the first fixing block 21 can slide smoothly along the first guide rod 312, thereby guiding the top plate 2 to move relative to the intermediate plate 3 in the first horizontal direction. The first guide component 31 has a simple structure, is stable and reliable, and can ensure the straightness and accuracy of the movement.

[0048] In some embodiments, the top of the base plate 1 is provided with a plurality of second guide components 11, the second guide components 11 including two spaced second locking blocks 111, and a second guide rod 112 arranged along the second horizontal direction is fixedly connected between the two second locking blocks 111; the bottom of the intermediate plate 3 is provided with a plurality of second fixing blocks 32, and the second fixing blocks 32 are slidably connected to the second guide rods 112.

[0049] Please refer to this as well. Figures 1 to 8 To ensure smooth guidance of the intermediate plate 3 relative to the base plate 1 along the second horizontal direction, this embodiment provides multiple sets of second guide components 11 on the top of the base plate 1. Each set of second guide components 11 includes two spaced-apart second locking blocks 111, which are fixedly mounted on the top surface of the base plate 1. A second guide rod 112 is fixedly connected between the two second locking blocks 111, with the axis of the second guide rod 112 arranged along the second horizontal direction and orthogonal to the axis of the first guide rod 312.

[0050] Multiple second fixing blocks 32 are fixedly installed at the bottom of the intermediate plate 3, and the number of second fixing blocks 32 matches the number of sets of second guide components 11. Each second fixing block 32 has a guide hole, through which the second fixing block 32 is sleeved onto the second guide rod 112 and slidably connected. When the intermediate plate 3 is subjected to a force in the second horizontal direction, the second fixing block 32 can slide smoothly along the second guide rod 112, thereby guiding the intermediate plate 3 to move relative to the base plate 1 in the second horizontal direction. Through the first guide component 31 and the second guide component 11, the movements in the first horizontal direction and the second horizontal direction do not interfere with each other.

[0051] In some embodiments, the positive stiffness element includes a first positive stiffness spring 4 sleeved on the first guide rod 312 and located between the first fixing block 21 and the first locking block 311, and a second positive stiffness spring 5 sleeved on the second guide rod 112 and located between the second fixing block 32 and the second locking block 111.

[0052] Please refer to this as well. Figures 1 to 8 In this embodiment, the positive stiffness element is a helical spring, specifically including multiple first positive stiffness springs 4 and multiple second positive stiffness springs 5. The first positive stiffness springs 4 are sleeved on the first guide rod 312 and located between the first fixing block 21 and the first locking block 311. Specifically, in each group of first guide components 31, a first positive stiffness spring 4 is provided between the first fixing block 21 and the two first locking blocks 311, that is, there is one first positive stiffness spring 4 on each side of the first fixing block 21. When the top plate 2 moves along the first horizontal direction, the first positive stiffness spring 4 on one side is compressed, and the first positive stiffness spring 4 on the other side is stretched, generating a restoring force opposite to the displacement direction, providing basic positive stiffness in the first horizontal direction.

[0053] Similarly, a second positive stiffness spring 5 is sleeved on the second guide rod 112 and located between the second fixing block 32 and the second locking block 111. In each group of second guide assemblies 11, a second positive stiffness spring 5 is provided between the second fixing block 32 and the two second locking blocks 111, that is, there is a second positive stiffness spring 5 on each side of the second fixing block 32, thereby providing basic positive stiffness in the second horizontal direction. By selecting springs with different stiffness coefficients, the static load-bearing capacity of the system can be adjusted.

[0054] In some embodiments, the first locking block 311 is provided with a first through hole, the first guide rod 312 passes through the first locking block 311 through the first through hole, and the two ends of the first guide rod 312 are threadedly connected to the first nuts 313. The first guide rod 312 is limited and fixed between the two first locking blocks 311 by the two first nuts 313; and / or, the second locking block 111 is provided with a second through hole, the second guide rod 112 passes through the second through hole through the second locking block 111, the two ends of the second guide rod 112 are threadedly connected to the second nuts 113. The second guide rod 112 is limited and fixed between the two second locking blocks 111 by the two second nuts 113.

[0055] Please refer to this as well. Figures 1 to 8 To ensure reliable fixation and ease of assembly of the first guide rod 312 and the first locking block 311, this embodiment employs a nut-locking structure. Specifically, the first locking block 311 has a first through hole, through which the first guide rod 312 passes, with both ends extending outwards from the first locking block 311, and each end is threaded with a first nut 313. By tightening the two first nuts 313, the first guide rod 312 is clamped and fixed between the two first locking blocks 311. This design makes the installation and removal of the first guide rod 312 very convenient, and also facilitates the adjustment of the axial position and tension of the first guide rod 312.

[0056] Similarly, the second locking block 111 has a second through hole, the second guide rod 112 passes through the second through hole, and both ends are locked and fixed by the second nut 113.

[0057] In some embodiments, the negative stiffness mechanism 6 includes:

[0058] Cam 61 is fixedly installed at the bottom of one of two adjacent plates that can move relative to each other;

[0059] The follower is located on top of the other of two adjacent plates that are relatively stationary, and contacts the profile surface of the cam 61;

[0060] The elastic element 62 is connected between the follower and the two relatively stationary plates, and is used to apply a preload force to the follower to press it against the profile surface of the cam 61.

[0061] Please refer to this as well. Figures 1 to 8The negative stiffness mechanism 6, which achieves near-zero stiffness, is the core component, specifically comprising a cam 61, a follower, and an elastic element 62. The cam 61 is fixed to the bottom of one of the two relatively movable plates. For example, between the top plate 2 and the intermediate plate 3, the cam 61 is fixed to the bottom of the top plate 2; between the intermediate plate 3 and the bottom plate 1, the cam 61 is fixed to the bottom of the intermediate plate 3. The follower is located on top of the other relatively stationary plate among the two adjacent plates. For example, between the top plate 2 and the intermediate plate 3, the follower is located on top of the intermediate plate 3; between the intermediate plate 3 and the bottom plate 1, the follower is located on top of the bottom plate 1. The follower maintains contact with the profile surface of the cam 61. The elastic element 62 connects the follower to the relatively stationary plate among the two plates, and applies a preload to the follower, ensuring it remains pressed against the profile surface of the cam 61.

[0062] When a movable plate (such as top plate 2) moves relative to a stationary plate (such as middle plate 3), cam 61 follows, and its profile surface pushes the follower to move. The movement of the follower causes the elastic element 62 to deform. Due to the specific curve design of the cam 61 profile (e.g., cosine curve, polynomial curve, etc.), the restoring force generated by the elastic element 62 exhibits nonlinear characteristics as displacement changes. That is, near the equilibrium position, the rate of change of the restoring force with displacement is negative, resulting in a negative stiffness effect. This negative stiffness is connected in parallel with the positive stiffness of the positive stiffness spring, and they cancel each other out near the equilibrium position, achieving quasi-zero stiffness.

[0063] Negative stiffness mechanisms 6 are provided between the top plate 2 and the middle plate 3, and between the middle plate 3 and the bottom plate 1. The negative stiffness provided by the negative stiffness mechanism 6 between the top plate 2 and the middle plate 3 cancels out the positive stiffness provided by the first positive stiffness spring 4 near the equilibrium position, achieving quasi-zero stiffness in the first horizontal direction. The negative stiffness provided by the negative stiffness mechanism 6 between the middle plate 3 and the bottom plate 1 cancels out the positive stiffness provided by the second positive stiffness spring 5 near the equilibrium position, achieving quasi-zero stiffness in the second horizontal direction, thereby achieving bidirectional horizontal vibration isolation.

[0064] In some embodiments, the follower is a roller 63, which is rotatably mounted on a bracket 64, and one end of an elastic element 62 is connected to the bracket 64.

[0065] Please refer to this as well. Figures 1 to 8 To reduce friction and improve sensitivity and lifespan, this embodiment uses a roller 63 as the follower. The roller 63 is rotatably mounted on a bracket 64, which is connected to one end of an elastic element 62. The outer circumferential surface of the roller 63 contacts the contour surface of the cam 61. When the cam 61 moves, the roller 63 rolls on the contour surface of the cam 61, converting sliding friction into rolling friction, greatly reducing frictional resistance and wear, making the vibration isolator more sensitive to minute vibrations.

[0066] In some embodiments, the other end of the elastic element 62 is provided with an adjusting member 65, which is detachably fixed to the top of the relatively stationary plate layer in two adjacent plate layers, for adjusting the initial preload of the elastic element 62.

[0067] Please refer to this as well. Figures 1 to 8 To facilitate adjustment of the negative stiffness, an adjusting member 65 is provided at the other end of the elastic element 62 in this embodiment. The adjusting member 65 is detachably fixed to the top of the relatively stationary plate layer among two adjacent plate layers. Specifically, the adjusting member 65 is fixed to the top of the relatively stationary plate layer among two adjacent plate layers by a screw and a nut. The screw passes through the adjusting member 65, with one end threadedly connected to the top of the relatively stationary plate layer among the two adjacent plate layers, and the other end threadedly connected to a nut. The nut abuts against the surface of the adjusting member 65, thereby pressing and fixing the adjusting member 65. When it is necessary to adjust the negative stiffness, first loosen the nut. At this time, the adjusting member 65 can rotate around the screw. By rotating the adjusting member 65, the initial tension or compression of the elastic element 62 can be changed, thereby fine-tuning its initial preload. After adjustment, rotate the nut to fix it against the adjusting member 65.

[0068] With this setup, by precisely adjusting the preload, the negative stiffness value generated by the negative stiffness mechanism 6 near the equilibrium position can be perfectly matched with the stiffness value of the positive stiffness spring, achieving the best near-zero stiffness effect and adapting to changes in different loads or working conditions.

[0069] Optionally, multiple threaded holes can be provided on the top of the relatively stationary plate in two adjacent plates. The adjusting member 65 is fixed at different threaded holes by connecting the screw to the different threaded holes. Due to the different positions of the adjusting member 65, the initial tension or compression of the elastic element 62 is different, which can also change the initial preload of the elastic element 62.

[0070] In some embodiments, the number of elastic elements 62 in a set of negative stiffness mechanisms 6 between two adjacent plates is two, and the two elastic elements 62 are symmetrically distributed on both sides of the cam 61.

[0071] Please refer to this as well. Figures 1 to 8 To ensure the force balance of the negative stiffness mechanism 6 and avoid generating additional torque, this embodiment incorporates two elastic elements 62 within the negative stiffness mechanism 6. These two elastic elements 62 are symmetrically distributed on both sides of the cam 61. The two elastic elements 62 have identical structures and parameters, and each contacts the contour surfaces of the cam 61 via its respective roller 63. When the cam 61 moves, the rollers 63 on both sides move simultaneously, causing the two elastic elements 62 to deform synchronously. The resulting force is symmetrical about the center of the cam 61, thus ensuring the balance of the forces, making the movement smoother, and improving the dynamic performance of the vibration isolator.

[0072] In some embodiments, the elastic element 62 is a helical spring.

[0073] Please refer to this as well. Figures 1 to 8 In this embodiment, the elastic element 62 is preferably a helical spring. Helical springs are simple in structure, low in cost, stable in performance, and easy to adjust the preload through the adjusting member 65. In other embodiments, other forms of elastic element 62, such as disc springs, can also be used, as long as they can provide the required linear restoring force.

[0074] The working process of the bidirectional horizontal quasi-zero stiffness vibration isolator provided by this invention is as follows:

[0075] During operation, external vibrations are input through the base plate 1. For vibrations in the first horizontal direction, the load on the top plate 2 generates an inertial force, causing the top plate 2 to move relative to the intermediate plate 3 in the first horizontal direction. At this time, the first positive stiffness spring 4 generates a restoring force (positive stiffness) opposite to the displacement direction. Simultaneously, the negative stiffness mechanism 6 between the top plate 2 and the intermediate plate 3 operates, and the cam 61 at the bottom of the top plate 2 moves accordingly, pushing the roller 63 on the intermediate plate 3 to roll, causing the elastic element 62 to deform and generate a restoring force (negative stiffness) in the same direction as the displacement. The positive and negative stiffnesses cancel each other out near the equilibrium position, making the system exhibit quasi-zero stiffness in the first horizontal direction, thereby effectively isolating low-frequency vibrations in the first horizontal direction.

[0076] For vibrations in the second horizontal direction, the intermediate plate 3 moves relative to the base plate 1 in the second horizontal direction. The second positive stiffness spring 5 and the negative stiffness mechanism 6 between the intermediate plate 3 and the base plate 1 also work in parallel to achieve quasi-zero stiffness vibration isolation in the second horizontal direction. The movements in the first and second horizontal directions are independent of each other, realizing bidirectional decoupling vibration isolation.

[0077] By adjusting the adjusting piece 65 at the end of the elastic element 62, the magnitude of the negative stiffness can be precisely adjusted to achieve the best match between the positive and negative stiffness, adapting to different loads and working conditions.

[0078] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0079] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A bidirectional horizontal quasi-zero stiffness vibration isolator, characterized in that, include: Base plate (1), used for mounting on the vibration source; The top plate (2) is located above the bottom plate (1) and is used to bear the load; An intermediate plate (3) is disposed between the bottom plate (1) and the top plate (2); the top plate (2) is configured to move relative to the intermediate plate (3) in a first horizontal direction, and the intermediate plate (3) is configured to move relative to the bottom plate (1) in a second horizontal direction, the second horizontal direction being orthogonal to the first horizontal direction; A vibration isolation mechanism is provided between the bottom plate (1) and the top plate (2) to make the equivalent dynamic stiffness in the first horizontal direction and the second horizontal direction approach zero near the equilibrium position. The vibration isolation mechanism includes a positive stiffness element and a negative stiffness mechanism (6).

2. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The top of the intermediate plate (3) is provided with multiple sets of first guide components (31). Each first guide component (31) includes two spaced first locking blocks (311). A first guide rod (312) is fixedly connected between the two first locking blocks (311) along the first horizontal direction. The bottom of the top plate (2) is provided with multiple first fixing blocks (21). The first fixing blocks (21) are slidably connected to the first guide rod (312).

3. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 2, characterized in that, The top of the base plate (1) is provided with multiple sets of second guide components (11), each second guide component (11) including two spaced second locking blocks (111), and a second guide rod (112) arranged along the second horizontal direction is fixedly connected between the two second locking blocks (111); the bottom of the intermediate plate (3) is provided with multiple second fixing blocks (32), and the second fixing blocks (32) are slidably connected to the second guide rod (112).

4. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 3, characterized in that, The positive stiffness element includes a first positive stiffness spring (4) sleeved on the first guide rod (312) and located between the first fixing block (21) and the first locking block (311), and a second positive stiffness spring (5) sleeved on the second guide rod (112) and located between the second fixing block (32) and the second locking block (111).

5. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 3, characterized in that, The first locking block (311) is provided with a first through hole, and the first guide rod (312) passes through the first locking block (311) through the first through hole. The two ends of the first guide rod (312) are threaded with first nuts (313). The first guide rod (312) is limited and fixed between the two first locking blocks (311) by the two first nuts (313); and / or, the second locking block (111) is provided with a second through hole, and the second guide rod (112) passes through the second locking block (111) through the second through hole. The two ends of the second guide rod (112) are threaded with second nuts (113). The second guide rod (112) is limited and fixed between the two second locking blocks (111) by the two second nuts (113).

6. The bidirectional horizontal quasi-zero stiffness vibration isolator according to any one of claims 1 to 5, characterized in that, The negative stiffness mechanism (6) includes: Cam (61) is fixedly installed at the bottom of one of two adjacent plates that can move relative to each other; The follower is located on top of the other of two adjacent plate layers that are relatively stationary, and contacts the profile surface of the cam (61); An elastic element (62) is connected between the follower and the two relatively stationary plates to apply a preload force to the follower to press it against the profile surface of the cam (61).

7. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 6, characterized in that, The driven member is a roller (63), which is rotatably mounted on a bracket (64), and one end of the elastic element (62) is connected to the bracket (64).

8. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 7, characterized in that, The other end of the elastic element (62) is provided with an adjusting member (65), which is detachably fixed on the top of the relatively stationary plate layer in two adjacent plate layers, and is used to adjust the initial preload of the elastic element (62).

9. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 6, characterized in that, The number of elastic elements (62) in a set of negative stiffness mechanisms (6) between two adjacent plates is two, and the two elastic elements (62) are symmetrically distributed on both sides of the cam (61).

10. The bidirectional horizontal quasi-zero stiffness vibration isolator according to claim 6, characterized in that, The elastic element (62) is a helical spring.

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