A compact multi-directional quasi-zero stiffness vibration isolator

Abstract

This invention discloses a compact multi-directional quasi-zero stiffness vibration isolator, belonging to the field of vibration isolators. It includes a housing, a mounting frame suspended within the housing by a tension assembly, and a guide shaft that slides vertically with the mounting frame, with its upper end extending out of the housing to connect to a load. An elastic portion providing vertical elastic support is provided between the mounting frame and the guide shaft. An inner magnetic ring is provided on the guide shaft, and an outer magnetic ring, coaxial and loosely fitted radially outside the inner magnetic ring, is provided on the mounting frame. These two components form a vertical negative stiffness assembly to compensate for vertical positive stiffness, making the vertical equivalent stiffness near the vertical equilibrium position approach zero. A ring-shaped leaf spring assembly is provided between the housing and the guide shaft. Its outer periphery is fixed to the housing, and its inner periphery is fitted onto the guide shaft and mutually restrained in the horizontal direction, elastically deforming when the guide shaft undergoes horizontal displacement. This invention achieves vertical quasi-zero stiffness vibration isolation and horizontal elastic vibration isolation within the same device, with a compact structure.

Description

Technical Field

[0001] This invention relates to the field of vibration isolators, and particularly to a compact multi-directional quasi-zero stiffness vibration isolator. Background Technology

[0002] With the development of technologies such as semiconductor manufacturing, precision machining, precision testing, and aerospace, the requirements for vibration control in the working environment of lithography equipment, precision measuring instruments, and ultra-precision machining equipment are becoming increasingly stringent. These devices typically have characteristics such as large load-bearing capacity, small allowable vibration displacement, and sensitivity to low-frequency vibrations. Therefore, how to effectively isolate low-frequency vibrations while ensuring stable equipment load-bearing capacity has become a crucial technical problem that needs to be solved in the field of precision vibration isolation.

[0003] Traditional passive vibration isolation devices typically consist of springs, rubber elastic elements, or other positive stiffness elastic support elements. Reducing the stiffness of such isolation devices can lower the system's natural frequency and improve low-frequency vibration isolation performance, but it also increases static deformation and the required working stroke, limiting the device's load-bearing capacity within the confined installation space and working stroke, which may affect the installation stability of the isolated equipment. Therefore, traditional linear vibration isolation devices struggle to simultaneously achieve both high static load-bearing capacity and low dynamic stiffness.

[0004] Active vibration isolation devices can actively compensate for vibrations through sensors, actuators, and controllers. However, they typically require external power and real-time control systems, resulting in complex structures and control processes, and high manufacturing and maintenance costs. The engineering application of active vibration isolation devices is somewhat limited in applications with large load-bearing capacities, limited installation space, or high requirements for long-term operational reliability.

[0005] To balance static load-bearing capacity and low-frequency vibration isolation performance, existing technologies have proposed quasi-zero stiffness vibration isolation devices. These devices typically combine a positive stiffness load-bearing mechanism with a negative stiffness mechanism. The positive stiffness load-bearing mechanism bears the static load, while the negative stiffness mechanism compensates for some of the positive stiffness near the equilibrium position, thereby reducing the equivalent dynamic stiffness and natural frequency of the system near the equilibrium position.

[0006] However, existing quasi-zero stiffness vibration isolation devices still have certain shortcomings. First, some quasi-zero stiffness vibration isolation devices are mainly designed for vibration isolation structures in a single direction. When it is necessary to isolate vibrations in both the horizontal and vertical directions simultaneously, multiple independent vibration isolation mechanisms are usually required, which can easily increase the overall structural volume and increase the difficulty of arranging and coordinating the movement of vibration isolation structures in each direction, making it difficult to achieve multi-directional vibration isolation within a limited installation space.

[0007] Secondly, the low-stiffness operating state of quasi-zero stiffness vibration isolation devices is related to the coordination between the positive stiffness mechanism and the negative stiffness mechanism. Existing devices are usually designed according to a predetermined load. When the mass of the isolated equipment changes, the static balance position of the isolation system may change accordingly, causing the system to deviate from the predetermined low-stiffness operating region, thus affecting the low-frequency vibration isolation performance. Therefore, the adaptability of existing quasi-zero stiffness vibration isolation devices to different loads still needs to be improved. Summary of the Invention

[0008] Based on this, the present invention provides a compact multi-directional quasi-zero stiffness vibration isolator, including a housing, a mounting frame suspended within the housing by multiple tension components, and a guide shaft that slides vertically with the mounting frame. The upper end of the guide shaft extends out of the housing and is used to connect a load. The mounting frame is provided with an elastic part that provides an upward elastic support force to the guide shaft. An inner magnetic ring is fixedly mounted on the guide shaft, and an outer magnetic ring coaxial with the inner magnetic ring and gapped radially outward is fixedly mounted on the mounting frame. An annular leaf spring assembly is provided between the housing and the guide shaft. The annular leaf spring assembly is fixedly mounted on the housing, and the inner circumference of the annular leaf spring assembly is sleeved on the guide shaft and mutually limited in the horizontal direction. The annular leaf spring assembly is used to generate elastic deformation when the guide shaft undergoes horizontal displacement relative to the housing. The inner magnetic ring and the outer magnetic ring cooperate to form a vertical negative stiffness component, which is used to compensate for the vertical positive stiffness of the vibration isolator, so that the vertical equivalent stiffness of the vibration isolator near the vertical equilibrium position approaches zero.

[0009] Furthermore, the guide shaft is provided with an abutment portion whose axial position is adjustable, and the elastic portion abuts against the lower end of the abutment portion so as to adjust the pre-tightening state of the elastic portion by adjusting the axial position of the abutment portion.

[0010] Furthermore, the mounting bracket is provided with a mounting support, and a guide sleeve is installed inside the mounting support. The guide shaft is vertically slidably mounted on the mounting support through the guide sleeve.

[0011] Furthermore, the elastic part is a compression spring sleeved outside the guide shaft, with the upper end of the compression spring abutting the lower end of the abutting part and the lower end of the compression spring abutting the mounting bracket.

[0012] Furthermore, the number of tension components is three, and they are evenly spaced around the guide shaft; each tension component includes a first connecting seat fixed to the housing, a second connecting seat fixed to the mounting bracket, and a steel wire rope connecting the first connecting seat and the second connecting seat; wherein, the steel wire rope is in a tensioned state when the vibration isolator is under load.

[0013] Furthermore, the first connecting seat includes a base and a connecting post threadedly connected to the base. The vertical position of the connecting post relative to the base is adjustable, and the upper end of the wire rope is connected to the connecting post.

[0014] Furthermore, the annular leaf spring assembly includes a plurality of annular leaf springs stacked axially along the guide shaft, with a washer sandwiched between two adjacent annular leaf springs; the annular leaf spring has an inner circumferential connecting portion, an outer circumferential connecting portion, and a plurality of elastic arms connecting the two and arranged at intervals along the circumferential direction, with an arc-shaped groove extending along the circumferential direction formed between two adjacent elastic arms.

[0015] Furthermore, the housing includes a housing body and a top cover detachably connected to its upper end. The top cover has a through hole for the guide shaft to pass through. The annular leaf spring assembly is installed at the through hole, and the upper end of the tension assembly is connected to the top cover.

[0016] Furthermore, the mounting bracket includes a base plate and a side wall surrounding the guide shaft. The base plate and the side wall together form a receiving cavity for accommodating the elastic part, and the outer magnetic ring is fixed to the side wall.

[0017] Furthermore, the mounting bracket also includes a top cover detachably connected to the side wall, the top cover having a through hole for the guide shaft to pass through.

[0018] The principles and effects of the present invention will be further explained below with reference to the above technical solutions and accompanying drawings: This invention provides vertical elastic support to the guide shaft through an elastic section, and utilizes the cooperation of an inner and outer magnetic ring to form a vertical negative stiffness assembly. This allows the vertical positive stiffness and vertical negative stiffness to compensate for each other near the vertical equilibrium position, thereby making the vertical equivalent stiffness approach zero while bearing the load, which is beneficial for improving low-frequency vertical vibration isolation performance. An annular leaf spring assembly is disposed between the guide shaft and the housing. When the two undergo horizontal relative displacement, they generate elastic deformation, forming a flexible connection in the horizontal plane between the load and the mounting foundation, achieving horizontal elastic vibration isolation.

[0019] The present invention suspends the mounting bracket inside the housing by means of a tension component and makes the guide shaft slide vertically with the mounting bracket; the vertical elastic support structure, the vertical negative stiffness component and the horizontal leaf spring vibration isolation structure are integrated around the same guide shaft, so that vertical quasi-zero stiffness vibration isolation and horizontal elastic vibration isolation can be achieved in the same device, which helps to reduce the installation space required for separately superimposed vibration isolation mechanisms and improve the compactness of the device. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the compact multi-directional quasi-zero stiffness vibration isolator described in an embodiment of the present invention; Figure 2This is a cross-sectional view of the compact multi-directional quasi-zero stiffness vibration isolator described in an embodiment of the present invention. Figure 3 This is a schematic diagram of the compact multi-directional quasi-zero stiffness vibration isolator according to an embodiment of the present invention with the outer shell removed; Figure 4 This is a schematic diagram of the structure of the annular leaf spring described in an embodiment of the present invention.

[0021] In the diagram: 11-Outer shell body, 12-Top cover, 21-Bottom plate, 22-Side wall, 23-Top cover, 31-Second connecting seat, 32-Wire rope, 33-Connecting column, 34-Base, 4-Mounting support, 5-Guide shaft, 51-Connecting end, 52-Threaded section, 53-Abutting part, 6-Inner magnetic ring, 7-Outer magnetic ring, 8-Annular leaf spring, 81-Inner circumferential connecting part, 82-Outer circumferential connecting part, 83-Elastic arm, 84-Arc groove, 9-Elastic part. Detailed Implementation

[0022] To facilitate understanding by those skilled in the art, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the directional terms such as "upper," "lower," "vertical," and "horizontal" used in this embodiment are based on the orientation of the vibration isolator when it is in a normal installation and load-bearing state, and are only used to describe the relative positional relationship between the components, and should not be construed as an absolute restriction on the installation direction of the vibration isolator.

[0023] like Figures 1-4 As shown, this embodiment provides a compact multi-directional quasi-zero stiffness vibration isolator, including a housing, a mounting bracket, a guide shaft 5, an elastic part 9, an inner magnetic ring 6, an outer magnetic ring 7, an annular leaf spring group 8, and multiple tension components.

[0024] The housing is used for mounting on a mounting base, and the mounting bracket is suspended inside the housing by a plurality of the tension components. The guide shaft 5 is vertically slidably engaged with the mounting bracket, and the upper end of the guide shaft 5 extends out of the housing to form a connection end 51 for connecting a load.

[0025] The elastic part 9 is disposed on the mounting bracket and provides an upward elastic support force to the guide shaft 5. The inner magnetic ring 6 is fixedly disposed on the guide shaft 5, and the outer magnetic ring 7 is fixedly disposed on the mounting bracket, and cooperates with the inner magnetic ring 6 to form a vertical negative stiffness assembly. The vertical positive stiffness provided by the elastic part 9 and the vertical negative stiffness provided by the vertical negative stiffness assembly compensate for each other, so that the vibration isolator exhibits quasi-zero stiffness characteristics near the vertical equilibrium position.

[0026] The 8-group annular leaf springs are disposed between the outer shell and the guide shaft 5, and are used to generate elastic deformation when the guide shaft 5 is horizontally displaced relative to the outer shell, thereby forming a flexible connection in the horizontal direction between the load and the foundation, and realizing elastic vibration isolation in the horizontal plane.

[0027] In this embodiment, the vertical equilibrium position refers to the position of the guide shaft 5 and the inner magnetic ring 6 fixed to the guide shaft 5 relative to the mounting bracket and the outer magnetic ring 7 when the vibration isolator bears a predetermined load and reaches static equilibrium. Preferably, in the vertical equilibrium position, the axial center planes of the inner magnetic ring 6 and the outer magnetic ring 7 coincide or substantially coincide.

[0028] The housing includes a housing body 11 and a top cover 12 detachably connected to the upper end of the housing body 11. The housing body 11 forms an internal space for accommodating the mounting bracket, the elastic part 9, the inner magnetic ring 6, the outer magnetic ring 7, and the tension assembly. The lower part of the housing body 11 may be provided with mounting holes and fixed to the ground, equipment frame, or other mounting base by fasteners.

[0029] A through hole is provided in the middle of the upper cover 12, and the upper end of the guide shaft 5 passes through the through hole and extends out of the outer shell. The annular leaf spring 8 group is installed at the through hole, thereby arranging the annular leaf spring 8 group around the guide shaft 5.

[0030] The mounting bracket is shell-shaped and includes a base plate 21 and a side wall 22 surrounding the guide shaft 5. The base plate 21 and the side wall 22 together form a receiving cavity, and the elastic part 9 is disposed within the receiving cavity. The mounting bracket also includes a top cover 23 detachably connected to the upper end of the side wall 22, and the top cover 23 has a through hole for the guide shaft 5 to pass through.

[0031] The top cover 23 and the side wall 22 can be connected by screws to facilitate the installation and maintenance of the elastic part 9, the inner magnetic ring 6, and the outer magnetic ring 7. The base plate 21, the side wall 22, and the top cover 23 together form an internal load-bearing frame, allowing the vertical elastic support structure and the vertical negative stiffness component to be centrally located within the mounting frame.

[0032] The number of tension components is three, which are evenly spaced around the guide shaft 5, with a circumferential interval of 120° between adjacent tension components. The three tension components together suspend the mounting bracket inside the housing and allow the mounting bracket to move slightly horizontally relative to the housing.

[0033] Each of the aforementioned tension components includes a first connecting seat 31, a second connecting seat 31, and a steel wire rope 32. The first connecting seat is fixedly disposed on the outer casing, preferably fixedly disposed on the upper cover 12; the second connecting seat 31 is fixedly disposed on the mounting bracket, preferably fixedly disposed on the base plate 21; the steel wire rope 32 connects the first connecting seat and the second connecting seat 31.

[0034] When the vibration isolator is under load and reaches static equilibrium, the self-weight of the mounting frame and the vertical force transmitted through the elastic part 9 keep the three steel wire ropes 32 taut. The three steel wire ropes 32 are evenly distributed circumferentially, forming multiple circumferential suspension points for the mounting frame, maintaining its predetermined installation posture and limiting excessive tilting or rotation. The tension assembly provides suspension, positioning, and posture constraint for the mounting frame, while the annular leaf springs 8 provide elastic support for horizontal vibration isolation.

[0035] In one specific embodiment, the first connecting seat includes a base 34 and a connecting post 33. The base 34 is fixed to the upper cover 12, and the base 34 has a threaded mounting hole with its axis extending vertically. The connecting post 33 has an external thread that mates with the threaded mounting hole and is threadedly connected to the base 34. The upper end of the steel wire rope 32 is connected to the connecting post 33, and the lower end of the steel wire rope 32 is connected to the second connecting seat 31.

[0036] By rotating the connecting post 33, the vertical position of the connecting post 33 relative to the base 34 can be adjusted, thereby adjusting the tension of the corresponding wire rope 32. Adjusting the three connecting posts 33 individually allows the three wire ropes 32 to have the same or substantially the same tension, and also allows for adjustment of the installation height and horizontal orientation of the mounting frame.

[0037] A mounting bracket 4 is fixedly mounted on the mounting frame. The mounting bracket 4 is preferably fixedly mounted on the base plate 21 and located in the middle of the receiving cavity. A guide sleeve is installed inside the mounting bracket 4. The lower end of the guide shaft 5 is inserted into the guide sleeve and slides vertically with the guide sleeve.

[0038] The guide sleeve allows the guide shaft 5 to move vertically relative to the mounting bracket and limits the guide shaft 5 in the horizontal direction. Thus, when the guide shaft 5 moves horizontally, it can drive the mounting bracket to move horizontally accordingly via the guide sleeve; when the guide shaft 5 moves vertically, it can slide up and down relative to the mounting bracket.

[0039] In one specific embodiment, the elastic part 9 is a cylindrical compression spring. The compression spring is sleeved on the lower part of the guide shaft 5, the lower end of the compression spring abuts against the mounting support 4, and the upper end of the compression spring abuts against the lower end of the abutment part 53 provided on the guide shaft 5.

[0040] When the guide shaft 5 moves downward relative to the mounting bracket, the abutment portion 53 moves downward with the guide shaft 5 and compresses the elastic portion 9, causing the elastic portion 9 to generate an upward elastic force. When the guide shaft 5 moves upward relative to the mounting bracket, the compression of the elastic portion 9 decreases, and its upward elastic force decreases accordingly. Therefore, the elastic portion 9 provides vertical stiffness near the vertical equilibrium position to prevent the guide shaft 5 from deviating from the vertical equilibrium position.

[0041] In one specific embodiment, the guide shaft 5 has an external thread in its middle portion to form a threaded segment 52. The abutment portion 53 has a threaded mounting hole that mates with the threaded segment 52, and is threadedly connected to the threaded segment 52 through the threaded mounting hole.

[0042] By rotating the abutment part 53, the axial position of the abutment part 53 relative to the guide shaft 5 can be changed, thereby changing the distance between the abutment part 53 and the mounting support 4, and adjusting the preload state of the elastic part 9. After the abutment part 53 is adjusted to the predetermined position, the rotation of the abutment part 53 can be restricted by locking the nut, set screw or other locking structure.

[0043] The inner magnetic ring 6 is fixedly sleeved on the guide shaft 5 and can move vertically relative to the mounting frame along the guide shaft 5. The outer magnetic ring 7 is fixedly disposed on the side wall 22 of the mounting frame and surrounds the radially outer side of the inner magnetic ring 6. The inner magnetic ring 6 and the outer magnetic ring 7 are coaxially arranged, forming a radial gap between them to avoid contact or interference when the inner magnetic ring 6 moves vertically relative to the outer magnetic ring 7.

[0044] In one specific embodiment, both the inner magnetic ring 6 and the outer magnetic ring 7 are axially magnetized annular permanent magnets, and their magnetization directions are the same. Specifically, when the upper end of the inner magnetic ring 6 is the N pole and the lower end is the S pole, the upper end of the outer magnetic ring 7 is also the N pole and the lower end is also the S pole; or, the upper ends of both the inner magnetic ring 6 and the outer magnetic ring 7 are S poles and the lower ends are both N poles.

[0045] In the vertical equilibrium position, the axial center planes of the inner magnetic ring 6 and the outer magnetic ring 7 coincide or substantially coincide. At this time, the magnetic forces acting on the inner magnetic ring 6 and the outer magnetic ring 7 on the upper and lower sides of the axial center plane are symmetrical. The upward and downward axial magnetic force components acting on the inner magnetic ring 6 cancel each other out, making the resultant axial magnetic force on the inner magnetic ring 6 zero or close to zero.

[0046] When the guide shaft 5 moves upward relative to the mounting bracket, the inner magnetic ring 6 shifts upward relative to the outer magnetic ring 7 along with the guide shaft 5, disrupting the original axial symmetry between the inner magnetic ring 6 and the outer magnetic ring 7. Because they employ the aforementioned magnetization direction and relative magnetic pole arrangement, the upward axial magnetic force component of the outer magnetic ring 7 acting on the inner magnetic ring 6 is greater than the downward axial magnetic force component, thereby generating an upward axial magnetic resultant force on the inner magnetic ring 6.

[0047] When the guide shaft 5 moves downward relative to the mounting bracket, the inner magnetic ring 6 shifts downward relative to the outer magnetic ring 7 along with the guide shaft 5. The downward axial magnetic force component of the outer magnetic ring 7 acting on the inner magnetic ring 6 is greater than the upward axial magnetic force component, thereby generating a downward axial magnetic resultant force on the inner magnetic ring 6.

[0048] Therefore, when the inner magnetic ring 6 deviates vertically from the vertical equilibrium position, the resultant axial magnetic force exerted by the outer magnetic ring 7 on the inner magnetic ring 6 is in the same direction as the vertical displacement of the inner magnetic ring 6. This axial magnetic force does not cause the inner magnetic ring 6 to return to the vertical equilibrium position, but rather causes the inner magnetic ring 6 to tend to continue moving in the offset direction. Thus, the inner magnetic ring 6 and the outer magnetic ring 7 together form a vertical negative stiffness component.

[0049] The process by which the elastic part 9 and the vertical negative stiffness component work together is as follows: when the guide shaft 5 deviates downward from the vertical equilibrium position relative to the mounting bracket, the upward elastic support force of the elastic part 9 increases; when the guide shaft 5 deviates upward, the upward elastic support force of the elastic part 9 decreases, thereby providing vertical positive stiffness. Simultaneously, the inner magnetic ring 6 moves axially relative to the outer magnetic ring 7, and the vertical negative stiffness component generates a magnetic force in the same direction as the vertical displacement of the guide shaft 5, thereby providing vertical negative stiffness.

[0050] By setting the stiffness of the elastic part 9 and the axial dimensions, radial dimensions, magnetic properties, and radial clearance of the inner magnetic ring 6 and the outer magnetic ring 7, the vertical positive stiffness provided by the elastic part 9 and the vertical negative stiffness provided by the vertical negative stiffness assembly can compensate for each other near the vertical equilibrium position, so that the vertical equivalent stiffness of the vibration isolator near the vertical equilibrium position approaches zero.

[0051] The inner magnetic ring 6 and the outer magnetic ring 7 can each be composed of a single annular permanent magnet, or they can each comprise multiple annular permanent magnets stacked axially. When the inner magnetic ring 6 and the outer magnetic ring 7 each comprise multiple annular permanent magnets, each inner magnetic ring 6 unit cooperates with the corresponding outer magnetic ring 7 unit to form a magnetic action unit. The inner magnetic ring 6 unit and the outer magnetic ring 7 unit in the same magnetic action unit adopt the same axial magnetization direction. The magnetization directions of adjacent magnetic action units can be the same or alternate, as long as the resultant axial magnetic force generated by all magnetic action units satisfies the aforementioned negative stiffness relationship.

[0052] The annular leaf spring group 8 comprises multiple annular leaf springs 8 stacked axially along the guide shaft 5, with washers sandwiched between adjacent annular leaf springs 8. The washers are used to maintain a corresponding distance between adjacent annular leaf springs 8, reserve space for the elastic deformation of the annular leaf springs 8, and ensure that the annular leaf spring group 8 is subjected to relatively uniform force during assembly.

[0053] Each of the annular leaf springs 8 includes an inner peripheral connecting portion 81, an outer peripheral connecting portion 82 surrounding the inner peripheral connecting portion 81, and a plurality of elastic arms 83 connecting the inner peripheral connecting portion 81 and the outer peripheral connecting portion 82. The plurality of elastic arms 83 are arranged at circumferential intervals along the annular leaf spring 8, and an arcuate groove 84 extending circumferentially is formed between two adjacent elastic arms 83.

[0054] The arc-shaped groove 84 extends the elastic deformation path between the inner peripheral connecting part 81 and the outer peripheral connecting part 82, enabling the elastic arm 83 to have a corresponding effective deformation length within a limited radial arrangement space. By setting the thickness, material, number and width of the elastic arms 83, and length and width of the arc-shaped groove 84 of the annular leaf spring 8, the horizontal stiffness and allowable deformation range of the annular leaf spring 8 assembly can be preset.

[0055] The outer peripheral connecting portion 82 of the annular leaf spring 8 is fixedly installed on the upper cover 12, and the inner peripheral connecting portion 81 is sleeved on the guide shaft 5 and mutually limits each other with the guide shaft 5 in the horizontal direction. When the guide shaft 5 moves horizontally relative to the outer shell, the guide shaft 5 drives the inner peripheral connecting portion 81 to move horizontally relative to the outer peripheral connecting portion 82, causing the multiple elastic arms 83 to elastically deform.

[0056] After the elastic arm 83 undergoes elastic deformation, it generates an elastic force pointing towards the horizontal equilibrium position, causing the annular leaf spring 8 group to form a flexible horizontal connection between the load and the foundation. As a result, the load and guide shaft 5 can generate a certain horizontal relative displacement relative to the outer shell, thereby reducing the transmission of horizontal vibrations from the foundation to the load.

[0057] Because the multiple elastic arms 83 are arranged at circumferential intervals, the annular leaf springs 8 group can produce elastic deformation in different directions within the horizontal plane. Therefore, the annular leaf springs 8 group can be used for elastic vibration isolation in the horizontal direction.

[0058] When the guide shaft 5 undergoes horizontal displacement relative to the housing, the guide sleeve restricts the movement of the guide shaft 5 relative to the mounting frame in the horizontal direction, causing the mounting frame to undergo corresponding horizontal displacement along with the guide shaft 5. During this process, the tilt state and tension of the three wire ropes 32 change accordingly, and the tension assembly constrains the posture of the mounting frame, thereby improving the stability during the horizontal movement of the load.

[0059] In one specific embodiment, the inner circumference of the annular leaf spring group 8 slides vertically with the outer circumference of the guide shaft 5, thereby limiting their mutual positioning in the horizontal direction. When the guide shaft 5 moves vertically, it can slide relative to the inner circumference of the annular leaf spring group 8, thus eliminating the requirement for the annular leaf spring group 8 to produce the same vertical displacement as the guide shaft 5. The annular leaf spring group 8 is mainly used to achieve elastic vibration isolation in the horizontal direction and does not serve as the main positive stiffness matching element of the vertical quasi-zero stiffness mechanism.

[0060] This embodiment achieves vertical quasi-zero stiffness vibration isolation through the elastic part 9 and the vertical negative stiffness assembly, and achieves horizontal elastic vibration isolation through the annular leaf spring group 8. The vertical vibration isolation movement is mainly manifested as the vertical sliding of the guide shaft 5 relative to the mounting bracket, and the horizontal vibration isolation movement is mainly manifested as the horizontal movement of the guide shaft 5 and the mounting bracket relative to the outer shell, thereby achieving vertical and horizontal vibration isolation within the same device.

[0061] In another specific embodiment, the inner periphery of the annular leaf spring group 8 is axially fixed to the guide shaft 5. When the guide shaft 5 moves vertically relative to the housing, the inner periphery moves with the guide shaft 5, and the elastic arm 83 undergoes out-of-plane bending and provides vertical positive stiffness. In this embodiment, the axial action of the annular leaf spring group 8 is incorporated into the vertical stiffness matching of the vibration isolator. By configuring the elastic part 9 with the vertical negative stiffness assembly, the vertical equivalent stiffness of the vibration isolator near the vertical equilibrium position approaches zero.

[0062] To accommodate different loads, the axial position of the abutment portion 53 relative to the guide shaft 5 can be adjusted according to the mass of the load to be borne. When the axial position of the abutment portion 53 changes, the preload state of the elastic portion 9 changes accordingly, thereby changing the elastic support force provided by the elastic portion 9 to the guide shaft 5 in the predetermined installation state.

[0063] In one usage, the position of the abutment portion 53 can be pre-set according to the mass of the load to be borne before the load is installed. After the load is connected to the connecting end 51 of the guide shaft 5, the weight of the load acts on the elastic portion 9 through the guide shaft 5 and the abutment portion 53, causing the elastic portion 9 to undergo corresponding compression deformation until the guide shaft 5 reaches a static equilibrium state.

[0064] By adjusting the axial position of the abutment part 53, when the guide shaft 5 reaches static balance, the inner magnetic ring 6 and the outer magnetic ring 7 are at or close to a predetermined axial relative position, so that the vibration isolator works in the vertical quasi-zero stiffness range under the corresponding load.

[0065] The above embodiments only illustrate one specific implementation of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, without departing from the concept of the present invention, corresponding modifications and improvements can be made to the specific shape, size, material, and fixing method of the housing, mounting bracket, elastic part 9, magnetic ring, annular leaf spring 8, and tension assembly. The scope of protection of the present invention should be determined by the appended claims.

Claims

1. A compact multi-directional quasi-zero stiffness vibration isolator, characterized in that, It includes a housing, a mounting bracket suspended within the housing by multiple tension components, and a guide shaft that slides vertically with the mounting bracket, the upper end of the guide shaft extending out of the housing and used to connect a load; The mounting bracket is provided with an elastic part that provides an upward elastic support force to the guide shaft. An inner magnetic ring is fixedly provided on the guide shaft. An outer magnetic ring that is coaxial with the inner magnetic ring and is gapped outside the inner magnetic ring in the radial direction is fixedly provided on the mounting bracket. An annular leaf spring assembly is provided between the outer shell and the guide shaft. The annular leaf spring assembly is fixedly installed on the outer shell, and the inner circumference of the annular leaf spring assembly is sleeved on the guide shaft and mutually limited with the guide shaft in the horizontal direction. The annular leaf spring assembly is used to generate elastic deformation when the guide shaft undergoes horizontal displacement relative to the outer shell. The inner magnetic ring and the outer magnetic ring cooperate to form a vertical negative stiffness component, which is used to compensate for the vertical positive stiffness of the vibration isolator, so that the vertical equivalent stiffness of the vibration isolator near the vertical equilibrium position approaches zero.

2. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The guide shaft is provided with an abutment portion whose axial position is adjustable. The elastic portion abuts against the lower end of the abutment portion so that the pre-tightening state of the elastic portion can be adjusted by adjusting the axial position of the abutment portion.

3. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 2, characterized in that, The mounting bracket is provided with a mounting support, and a guide sleeve is installed inside the mounting support. The guide shaft is vertically slidably mounted on the mounting support through the guide sleeve.

4. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 3, characterized in that, The elastic part is a compression spring sleeved outside the guide shaft. The upper end of the compression spring abuts against the lower end of the abutting part, and the lower end of the compression spring abuts against the mounting bracket.

5. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The number of tension components is three, and they are evenly spaced around the guide shaft; each tension component includes a first connecting seat fixed to the housing, a second connecting seat fixed to the mounting bracket, and a steel wire rope connecting the first connecting seat and the second connecting seat.

6. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 5, characterized in that, The first connecting seat includes a base and a connecting post threadedly connected to the base. The vertical position of the connecting post relative to the base is adjustable, and the upper end of the wire rope is connected to the connecting post.

7. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The annular leaf spring assembly includes multiple annular leaf springs stacked axially along the guide shaft, with a washer sandwiched between two adjacent annular leaf springs; each annular leaf spring has an inner circumferential connecting portion, an outer circumferential connecting portion, and multiple elastic arms connecting the two and spaced apart circumferentially, with an arc-shaped groove extending circumferentially between two adjacent elastic arms.

8. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The housing includes a housing body and a top cover detachably connected to its upper end. The top cover has a through hole for the guide shaft to pass through. The annular leaf spring assembly is installed at the through hole, and the upper end of the tension assembly is connected to the top cover.

9. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The mounting bracket includes a base plate and a side wall surrounding the guide shaft. The base plate and the side wall together form a cavity for accommodating the elastic part, and the outer magnetic ring is fixed to the side wall.

10. The compact multi-directional quasi-zero stiffness vibration isolator according to claim 9, characterized in that, The mounting bracket also includes a top cover detachably connected to the side wall, the top cover having a through hole for the guide shaft to pass through.

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