阅读说明：本技术 一种包含组合型磁负刚度机构的近零刚度隔振系统 (Near-zero stiffness vibration isolation system comprising combined magnetic negative stiffness mechanism ) 是由 姜伟 吴九林 陈学东 周一帆 吴明凯 于 2021-08-26 设计创作，主要内容包括：本发明公开一种包含组合型磁负刚度机构的近零刚度隔振系统,涉及隔振领域,其包括底座、负载平台、正刚度单元和组合型磁负刚度单元,正刚度单元和组合型磁负刚度单元位于底座和负载平台之间,正刚度单元和组合型磁负刚度单元并联,正刚度单元包括正刚度特性的弹性元件,弹性元件设置在底座和负载平台之间,组合型磁负刚度单元包括至少一个斥力型磁负刚度机构和至少一个吸力型磁负刚度机构,斥力型磁负刚度机构和吸力型磁负刚度机构并联。本发明为组合型的结构设计,可方便调节和匹配斥力型与吸力型磁负刚度机构的参数,能大幅提升隔振系统有效工作范围和刚度线性度,在宽的工作区域内实现综合刚度近零且工作稳定的隔振效果。(The invention discloses a near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism, which relates to the field of vibration isolation and comprises a base, a load platform, a positive stiffness unit and a combined magnetic negative stiffness unit, wherein the positive stiffness unit and the combined magnetic negative stiffness unit are positioned between the base and the load platform, the positive stiffness unit and the combined magnetic negative stiffness unit are connected in parallel, the positive stiffness unit comprises an elastic element with positive stiffness characteristics, the elastic element is arranged between the base and the load platform, the combined magnetic negative stiffness unit comprises at least one repulsion magnetic negative stiffness mechanism and at least one suction magnetic negative stiffness mechanism, and the repulsion magnetic negative stiffness mechanism and the suction magnetic negative stiffness mechanism are connected in parallel. The invention is a combined structural design, can conveniently adjust and match parameters of the repulsion type and suction type magnetic negative stiffness mechanisms, can greatly improve the effective working range and stiffness linearity of the vibration isolation system, and realizes the vibration isolation effect with near-zero comprehensive stiffness and stable work in a wide working area.)

1. A near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism is characterized by comprising a base (1), a load platform (9), a positive stiffness unit (2) and a combined magnetic negative stiffness unit, wherein the positive stiffness unit (2) and the combined magnetic negative stiffness unit are positioned between the base (1) and the load platform (9), the positive stiffness unit (2) and the combined magnetic negative stiffness unit are connected in parallel,

the positive stiffness unit (2) comprises an elastic element with positive stiffness characteristic, the elastic element is arranged between the base (1) and the load platform (9) and is used for providing supporting force required by balancing the gravity of the load and providing basic vibration isolation function,

the combined magnetic negative stiffness unit comprises at least one repulsion type magnetic negative stiffness mechanism and at least one attraction type magnetic negative stiffness mechanism, and the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism are connected in parallel.

2. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 1, wherein the repulsive-type magnetic negative stiffness mechanism comprises at least one repulsive-type magnetic negative stiffness mechanism fixed magnet (62) and at least one repulsive-type magnetic negative stiffness mechanism movable magnet (61), the repulsive-type magnetic negative stiffness mechanism fixed magnet (62) and the repulsive-type magnetic negative stiffness mechanism movable magnet (61) are arranged in a row and a plurality of rows along an excitation direction, the excitation directions of all the repulsive-type magnetic negative stiffness mechanism fixed magnets and all the repulsive-type magnetic negative stiffness mechanism movable magnets are set to be perpendicular to the vibration isolation direction, the repulsive-type magnetic negative stiffness mechanism fixed magnets and the repulsive-type magnetic negative stiffness mechanism movable magnets in the same row are arranged in a staggered manner, the excitation directions of all the repulsive-type magnetic negative stiffness mechanism fixed magnets are the same, and the excitation directions of all the repulsive-type magnetic negative stiffness mechanism movable magnets are the same, the excitation directions of the adjacent repulsion type magnetic negative stiffness mechanism fixed magnets and the repulsion type magnetic negative stiffness mechanism movable magnets are opposite, so that the repulsion type magnetic negative stiffness mechanism fixed magnets and the repulsion type magnetic negative stiffness mechanism movable magnets form repulsion type magnetic negative stiffness characteristics in a normal direction perpendicular to the excitation direction, and the normal direction is taken as a vibration isolation direction playing a role in negative stiffness.

3. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 2, wherein in the repulsion type magnetic negative stiffness mechanism, the number of the repulsion type magnetic negative stiffness mechanism fixed magnets (62) and the number of the repulsion type magnetic negative stiffness mechanism movable magnets (61) in the same row are different by one, so that the acting force of the repulsion type magnetic negative stiffness mechanism fixed magnets and the repulsion type magnetic negative stiffness mechanism movable magnets in the excitation direction is close to zero when the distance between the adjacent repulsion type magnetic negative stiffness mechanism fixed magnets and the repulsion type magnetic negative stiffness mechanism movable magnets in the excitation direction is equal, and the balance and the stability of the vibration isolation system are facilitated.

4. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 2, wherein the repulsive-type magnetic negative stiffness mechanism comprises a plurality of repulsive-type magnetic negative stiffness mechanism fixed magnets (62) and a plurality of repulsive-type magnetic negative stiffness mechanism movable magnets (61), the plurality of repulsive-type magnetic negative stiffness mechanism fixed magnets and the plurality of repulsive-type magnetic negative stiffness mechanism movable magnets are arranged in a multi-row and multi-column manner along an excitation direction, and the excitation directions of all repulsive-type magnetic negative stiffness mechanism fixed magnets and all repulsive-type magnetic negative stiffness mechanism movable magnets are set to be perpendicular to the vibration isolation direction,

the repulsion type magnetic negative stiffness mechanism fixed magnets and the repulsion type magnetic negative stiffness mechanism moving magnets in the same row are arranged in a staggered mode, the excitation directions of the repulsion type magnetic negative stiffness mechanism fixed magnets and the repulsion type magnetic negative stiffness mechanism moving magnets which are adjacent in the same row are opposite, the excitation directions of the repulsion type magnetic negative stiffness mechanism fixed magnets in the adjacent rows in the same column are opposite, the excitation directions of the repulsion type magnetic negative stiffness mechanism moving magnets in the adjacent rows in the same column are also opposite, and the arrangement enables the stator magnets or the moving magnets in multiple rows in the same column to be naturally configured into a whole.

5. The near-zero stiffness vibration isolation system comprising a combined type magnetic negative stiffness mechanism according to any one of claims 1 to 4, wherein the suction type magnetic negative stiffness mechanism comprises at least one suction type magnetic negative stiffness mechanism moving magnet (41) and at least one suction type magnetic negative stiffness mechanism fixed magnet (42), the suction type magnetic negative stiffness mechanism fixed magnet and the suction type magnetic negative stiffness mechanism moving magnet are arranged in a row and a plurality of rows along an excitation direction, the excitation direction is the same as the vibration isolation direction, the suction type magnetic negative stiffness mechanism fixed magnet and the suction type magnetic negative stiffness mechanism moving magnet in the same row are arranged in a staggered manner, the excitation directions of all the suction type magnetic negative stiffness mechanism fixed magnets and the suction type magnetic negative stiffness mechanism moving magnet are all the same, the arrangement is such that the suction type magnetic negative stiffness mechanism fixed magnet and the suction type magnetic negative stiffness mechanism moving magnet have a suction type magnetic negative stiffness characteristic in the excitation direction, the excitation direction serves as a vibration isolation direction that acts as a negative stiffness.

6. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 5, wherein in the attraction type magnetic negative stiffness mechanism, the number of the fixed magnets of the attraction type magnetic negative stiffness mechanism and the number of the movable magnets of the attraction type magnetic negative stiffness mechanism in the same column are different by one, so that when the distance between the adjacent fixed magnets of the attraction type magnetic negative stiffness mechanism and the adjacent movable magnets of the attraction type magnetic negative stiffness mechanism in the excitation direction is equal, the acting force of the fixed magnets of the attraction type magnetic negative stiffness mechanism and the acting force of the movable magnets of the attraction type magnetic negative stiffness mechanism in the excitation direction are close to zero, and the balance and the stability of the vibration isolation system are facilitated.

7. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 6, wherein the attraction type magnetic negative stiffness mechanism moving magnet (41) and the repulsion type magnetic negative stiffness mechanism moving magnet (61) are suspended at the bottom surface of the loading platform (9) through a moving magnet connecting piece (7), the attraction type magnetic negative stiffness mechanism fixed magnet (42) is fixed on the base (1) through an attraction type magnetic set connecting piece (3), and the repulsion type magnetic negative stiffness mechanism fixed magnet (62) is fixed on the base (1) through a repulsion type magnetic set connecting piece (5).

8. The near zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism of claim 7 wherein the positive stiffness unit is selected from one or more of a coil spring, a leaf spring, an air spring, a rubber member, a positive stiffness magnetic mechanism.

9. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 8, wherein the attraction type magnetic negative stiffness mechanism is formed by coaxially stacking an upper attraction type magnetic negative stiffness mechanism fixed magnet (42) and a lower attraction type magnetic negative stiffness mechanism fixed magnet (41) which are annular, the attraction type magnetic negative stiffness mechanism movable magnet (41) is arranged between the two attraction type magnetic negative stiffness mechanism fixed magnets (42), the three magnets are arranged along the Z direction, and the magnetizing directions of the three magnets are all along the Z direction.

10. The near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism according to claim 9, wherein the repulsive force type magnetic negative stiffness mechanism is composed of a coaxially arranged annular repulsive force type magnetic negative stiffness mechanism fixed magnet (62) and an annular repulsive force type magnetic negative stiffness mechanism movable magnet (61), the repulsive force type magnetic negative stiffness mechanism fixed magnet (62) is arranged at the periphery of the repulsive force type magnetic negative stiffness mechanism movable magnet (61), the magnetizing directions of the two annular magnets are radial magnetizing, and the magnetizing directions are opposite.

Technical Field

The invention relates to the field of vibration isolation, in particular to a near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism.

Background

The vibration problem is commonly existed in various fields of industrial production and engineering, and as various mechanical devices are developed to high speed, high precision and high stability, the requirements for vibration are more and more strict. It is desirable to isolate the transmission of the vibration excitation of the equipment to its mounting base or the transmission of the vibration of the mounting base to the equipment using vibration isolators.

The low vibration isolation rigidity and the high bearing capacity are the targets continuously pursued by the design of the vibration isolator, the low vibration isolation rigidity and the high bearing capacity are usually contradictory to each other in a conventional linear rigidity vibration isolation system, and the adoption of a mode of connecting the positive rigidity and the negative rigidity in parallel is an effective way for solving the contradiction. The magnet structure has the characteristics of like-pole repulsion-opposite-pole attraction: the like magnet pair has negative rigidity characteristic in the normal direction of the maximum repulsion direction, and the amplitude of the negative rigidity is reduced along with the increase of the relative displacement of the magnet pair; the opposite magnet pair also has a negative stiffness characteristic in the direction of maximum attraction, and the magnitude of the negative stiffness increases as the relative displacement of the magnet pair increases. The repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism can be connected with the elastic element with the positive stiffness characteristic in parallel to form the characteristic of high static stiffness-low dynamic stiffness so as to realize lower comprehensive vibration isolation stiffness on the premise of ensuring the bearing capacity and solve the contradiction between vibration isolation and bearing.

However, the negative stiffness nonlinearity characteristics of the two magnetic negative stiffness mechanisms are obvious, the comprehensive stiffness of the vibration isolator is difficult to approach zero and keep stable in a relatively wide working stroke, namely the comprehensive stiffness of the vibration isolator is difficult to approach zero and the stable region is narrow; in addition, due to the narrow negative stiffness stability region of such mechanisms, the installation and adjustment of the mechanisms are often difficult, so that the actual working region of the vibration isolation system often deviates from the designed low stiffness region, and further the actual vibration isolation performance is deteriorated.

Therefore, the negative stiffness mechanism with high linearity and wide stability domain needs to be invented to form a high-stability near-zero stiffness vibration isolation system in parallel with the positive stiffness mechanism.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism, wherein a repulsion type magnetic negative stiffness mechanism and a suction type magnetic negative stiffness mechanism are connected in parallel to form the combined magnetic negative stiffness mechanism, the combined structure design can conveniently adjust and match the parameters of the repulsion type magnetic negative stiffness mechanism and the suction type magnetic negative stiffness mechanism, the effective working range and the stiffness linearity of the vibration isolation system can be greatly improved, and the vibration isolation effect of near-zero comprehensive stiffness and stable working can be realized in a wide working area.

In order to achieve the above object, the present invention provides a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism, which includes a base, a load platform, a positive stiffness unit and a combined magnetic negative stiffness unit, wherein the positive stiffness unit and the combined magnetic negative stiffness unit are located between the base and the load platform, the positive stiffness unit and the combined magnetic negative stiffness unit are connected in parallel, the positive stiffness unit includes an elastic element with positive stiffness characteristic, the elastic element is disposed between the base and the load platform and is used for providing a supporting force required for balancing the load gravity and providing a basic vibration isolation function, the combined magnetic negative stiffness unit includes at least one repulsion type magnetic negative stiffness mechanism and at least one attraction type magnetic negative stiffness mechanism, and the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism are connected in parallel.

Preferably, the repulsion type magnetic negative stiffness mechanism comprises at least one stator magnet and at least one rotor magnet, the stator magnet and the rotor magnet are arranged in a row and a plurality of rows along an excitation direction, the excitation direction of the stator magnet and the rotor magnet is arranged to be perpendicular to the vibration isolation direction, the stator magnet and the rotor magnet in the same row are arranged in a staggered manner, the excitation directions of all the stator magnets are the same, the excitation directions of all the rotor magnets are the same, the excitation directions of adjacent stator magnets and rotor magnets are opposite, so that the stator magnet and the rotor magnet have repulsion type magnetic negative stiffness characteristics in a normal direction perpendicular to the excitation direction, and the direction is used as the vibration isolation direction playing a role of negative stiffness.

Preferably, the number of the stator magnets in the same row is different from the number of the rotor magnets by one, so that the distance between the adjacent stator magnets and the adjacent rotor magnets in the excitation direction is equal, the acting force of the stator magnets and the acting force of the rotor magnets in the excitation direction are basically zero, and the balance and the stability of the vibration isolation system are facilitated.

Preferably, a plurality of layers (in the form of a plurality of layers, that is, a plurality of rows) of the stator magnets and the mover magnets may be arranged in the vibration isolation direction to increase the magnetic negative stiffness value. Preferably, the excitation directions of the stator magnets of the adjacent layers of the same column are set to be opposite, and correspondingly, the excitation directions of the mover magnets of the adjacent layers of the same column are also set to be opposite, so that the stator magnets or the mover magnets of the plurality of layers in the same column can be naturally assembled into a whole respectively without applying excessive external pressure in the vibration isolation direction for fastening assembly.

The suction type magnetic negative stiffness mechanism comprises at least one suction type magnetic negative stiffness mechanism movable magnet and at least one suction type magnetic negative stiffness mechanism fixed magnet, the suction type magnetic negative stiffness mechanism fixed magnet and the suction type magnetic negative stiffness mechanism movable magnet are arranged in a row and a plurality of rows along an excitation direction, the excitation direction is set to be the same as the vibration isolation direction, the suction type magnetic negative stiffness mechanism fixed magnets and the suction type magnetic negative stiffness mechanism movable magnets in the same row are arranged in a staggered mode, and the excitation directions of all the suction type magnetic negative stiffness mechanism fixed magnets and the suction type magnetic negative stiffness mechanism movable magnets are all the same. The above configuration causes the fixed magnet and the movable magnet to have an attraction type magnetic negative stiffness characteristic in the excitation direction as the vibration isolation direction that acts as the negative stiffness.

Preferably, in the suction type magnetic negative stiffness mechanism, the number of the fixed magnets and the number of the movable magnets in the same row are different by one, so that when the distance between the adjacent fixed magnets and the adjacent movable magnets in the excitation direction is equal, the acting force of the fixed magnets and the acting force of the movable magnets in the excitation direction are basically zero, and the balance and the stability of the vibration isolation system are facilitated.

Preferably, the attraction type magnetic negative stiffness mechanism moving magnet and the repulsion type magnetic negative stiffness mechanism moving magnet are both suspended at the bottom surface of the load platform through moving magnet connecting pieces, the attraction type magnetic negative stiffness mechanism fixed magnet is fixed on the base through attraction type magnetic set connecting pieces, and the repulsion type magnetic negative stiffness mechanism fixed magnet is fixed on the base through repulsion type magnetic set connecting pieces.

Preferably, the positive stiffness unit is selected from one or more of a coil spring, a leaf spring, an air spring, a rubber element, a positive stiffness magnetic mechanism.

Preferably, the suction type magnetic negative stiffness mechanism is formed by coaxially overlapping an upper ring-shaped suction type magnetic negative stiffness mechanism fixed magnet and a lower ring-shaped suction type magnetic negative stiffness mechanism movable magnet, the suction type magnetic negative stiffness mechanism movable magnet is arranged between the two suction type magnetic negative stiffness mechanism fixed magnets, the three magnets are arranged along the Z direction, and the magnetizing directions of the three magnets are all along the Z direction.

Preferably, the repulsion type magnetic negative stiffness mechanism is composed of a ring-shaped repulsion type magnetic negative stiffness mechanism fixed magnet and a ring-shaped repulsion type magnetic negative stiffness mechanism moving magnet which are coaxially arranged, the repulsion type magnetic negative stiffness mechanism fixed magnet is arranged at the periphery of the repulsion type magnetic negative stiffness mechanism moving magnet, the magnetizing directions of the two ring-shaped magnets are radial magnetizing, and the magnetizing directions are opposite.

Through the technical scheme, compared with the prior art, the invention can obtain the following beneficial effects:

according to the combined magnetic negative stiffness mechanism, the complementarity of the negative stiffness variation trends of the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism along with the relative displacement is utilized, the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism are connected in parallel to form the combined magnetic negative stiffness mechanism, the size of the magnet, the gap and the distance between the magnet and the magnet can be flexibly selected, and the linear negative stiffness in different ranges and different sizes can be realized by adjusting the parameters, so that different vibration isolation systems and actual requirements are met. Moreover, the combined linear magnetic negative stiffness mechanism has larger negative stiffness volume density, and can realize larger negative stiffness with smaller space cost in practical application. In addition, the near-zero stiffness vibration isolation system of the combined magnetic negative stiffness mechanism can better improve the stability, the bearing capacity and the anti-interference capacity of the vibration isolation system.

Drawings

FIG. 1 is a schematic diagram of a near zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in an embodiment of the invention;

FIG. 2 is a linear stiffness schematic of the combined magnetic negative stiffness mechanism of the present invention;

FIG. 3 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism according to example 1 of the present invention;

FIG. 4 is a top view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism according to example 1 of the present invention;

fig. 5 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism according to example 2 of the present invention.

Fig. 6 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in accordance with example 3 of the present invention.

Fig. 7 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in accordance with example 4 of the present invention.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein:

1-a base; 2-a positive stiffness unit; 3-a suction type magnetic group connector; 5-repulsive force type magnetic set connection member; 7-moving magnet linkage; 8-a guide mechanism; 9-a load platform; 41-a dynamic magnet of a suction type magnetic negative stiffness mechanism; 42-fixed magnet of magnetic negative rigidity mechanism of attraction type; 61-repulsive force type magnetic negative stiffness mechanism moving magnet; 62-repulsion type magnetic negative stiffness mechanism fixed magnet.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a near-zero stiffness vibration isolation system comprising a combined magnetic negative stiffness mechanism, which has a reasonable and ingenious structural design, and the design principle is specifically explained by combining the attached drawings of the specification:

fig. 1 is a schematic diagram of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism according to an embodiment of the present invention, fig. 2 is a schematic diagram of linear stiffness of the combined magnetic negative stiffness mechanism according to the present invention, and it can be seen from fig. 1 and fig. 2 that the negative stiffness k of the combined magnetic negative stiffness unit according to the present invention_neThe suction type negative stiffness k shown in FIG. 1₁And repulsive force type negative rigidity k₂And (4) overlapping. As shown in FIG. 2, for the attraction type magnetic negative stiffness mechanism, the stiffness characteristic k thereof₁The negative stiffness is shown to have the smallest amplitude at the equilibrium position (i.e., the position with 0 displacement), and the larger the negative stiffness is, the more the negative stiffness is deviated from the equilibrium position, so that the convex characteristic is shown. And for the repulsive force type magnetic negative stiffness mechanism, the stiffness characteristic k thereof₂The maximum negative stiffness value amplitude value at the equilibrium position is shown, and the farther the negative stiffness value deviates from the equilibrium position, the smaller the negative stiffness value is, and the concave characteristic is shown. The suction type negative stiffness mechanism and the repulsion type negative stiffness mechanism are connected in parallel, so the total negative stiffness k_neIs the sum of the two, namely:

k_ne＝k₁+k₂

through the optimized matching of the structural parameters of the attraction type magnetic negative stiffness mechanism and the repulsion type magnetic negative stiffness mechanism, the convex stiffness characteristics and the concave stiffness characteristics are mutually offset, so that a combined magnetic negative stiffness characteristic curve k shown in figure 2 is obtained_neThe effective working range of the magnetic negative stiffness and the linearity in the range are greatly improved to approach the stiffness of the positive stiffness unit as much as possible, namely, the comprehensive stiffness of the vibration isolation system is close to zero as much as possible, so that the vibration isolation performance is improved, the stability of the vibration isolation system can be enhanced, and the installation and adjustment difficulty of the system is reduced.

Fig. 3 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in embodiment 1 of the present invention, fig. 4 is a top view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in embodiment 1 of the present invention, and as can be seen from fig. 3 and fig. 4, the vibration isolation system includes a base 1, a positive stiffness unit 2, a suction type magnetic group connecting member 3, a suction type magnetic negative stiffness mechanism moving magnet 41, two suction type magnetic negative stiffness mechanism fixed magnets 42, a repulsion type magnetic group connecting member 5, a repulsion type magnetic negative stiffness mechanism moving magnet 61, two repulsion type magnetic negative stiffness mechanism fixed magnets 62, a moving magnet connecting member 7, a guide mechanism 8, and a load platform 9.

Specifically, the base 1 may be a base of a vibration isolation system, or may be a foundation. The positive stiffness unit 2 is a conventional positive stiffness elastic element, which may be a coil spring, a leaf spring, an air spring, a rubber element, a positive stiffness magnetic mechanism, etc., and is used to support the isolated body and realize a basic vibration isolation function.

The attraction type magnetic negative stiffness mechanism is composed of an upper attraction type magnetic negative stiffness mechanism fixed magnet 42, a lower attraction type magnetic negative stiffness mechanism fixed magnet 42 and an attraction type magnetic negative stiffness mechanism movable magnet 41, the attraction type magnetic negative stiffness mechanism movable magnet 41 is located between the two attraction type magnetic negative stiffness mechanism fixed magnets 42, the three magnets are arranged along the Z direction, the magnetizing directions of the three magnets are the same, and the three magnets are magnetized along the Z direction. Wherein, the two fixed magnets 42 of the attraction type magnetic negative stiffness mechanism are fixedly connected with the base 1 through the respective independent attraction type magnetic group connecting piece 3.

The repulsion type magnetic negative stiffness mechanism is composed of a left repulsion type magnetic negative stiffness mechanism fixed magnet 62, a right repulsion type magnetic negative stiffness mechanism fixed magnet 62 and a repulsion type magnetic negative stiffness mechanism movable magnet 61, the three magnets are arranged along the X direction, and the repulsion type magnetic negative stiffness mechanism movable magnet 61 is positioned on the two repulsion type magnetic negative stiffness mechanism fixed magnets 62. The two repulsion type magnetic negative stiffness mechanism fixed magnets 62 have the same magnetizing direction and are along the X direction, and are fixedly connected with the base 1 through respective independent repulsion type magnetic group connecting pieces 5. The magnetizing direction of the repulsive force type magnetic negative stiffness mechanism moving magnet 61 is also along the X direction, but is opposite to the magnetizing directions of the two repulsive force type magnetic negative stiffness mechanism fixed magnets 62.

The load platform 9 is a load platform for supporting an object to be vibration-isolated or a supported object to be vibration-isolated, one end of the movable magnet connecting piece 7 is fixed below the load platform 9, and the other end of the movable magnet connecting piece respectively suspends the attraction type magnetic negative stiffness mechanism movable magnet 41 and the repulsion type magnetic negative stiffness mechanism movable magnet 61, so that the attraction type magnetic negative stiffness mechanism movable magnet 41 and the repulsion type magnetic negative stiffness mechanism movable magnet 61 are fixedly connected with the load platform 9.

The guide mechanism is a linear guide rail 8 and comprises a guide rod and a sliding block, the guide rod is fixedly connected with the base 1, the sliding block is fixedly connected with the load platform 9, and when the sliding block slides along the guide rod, the load platform 9 is driven to move in the Z direction only along the guide rail relative to the base 1.

Fig. 5 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in embodiment 2 of the present invention, and fig. 5 is a front view of an embodiment 2 of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism, which is different from embodiment 1 in that embodiment 2 employs two sets of attractive magnetic negative stiffness mechanisms and one set of repulsive magnetic negative stiffness mechanisms connected in parallel to form a combined linear magnetic negative stiffness unit. The two groups of attraction type magnetic negative stiffness mechanisms are respectively positioned at two sides of the one group of repulsion type magnetic negative stiffness mechanisms, have the same structure and are symmetrical about the repulsion type magnetic negative stiffness mechanisms. Each group of the attraction type magnetic negative stiffness mechanisms comprises an upper attraction type magnetic negative stiffness mechanism fixed magnet 42, a lower attraction type magnetic negative stiffness mechanism fixed magnet 42 and an attraction type magnetic negative stiffness mechanism movable magnet 41, wherein one attraction type magnetic negative stiffness mechanism movable magnet 41 is positioned between the two attraction type magnetic negative stiffness mechanism fixed magnets 42, three magnets in each group of the attraction type magnetic negative stiffness mechanisms are arranged along the Z direction, the magnetizing directions of the three magnets are the same and are magnetized along the Z direction, and the two attraction type magnetic negative stiffness mechanism fixed magnets 42 in each group of the attraction type magnetic negative stiffness mechanisms are fixedly connected with the base 1 through respective independent attraction type magnetic group connecting pieces 3. The repulsion type magnetic negative stiffness mechanism comprises a left repulsion type magnetic negative stiffness mechanism fixed magnet 62, a right repulsion type magnetic negative stiffness mechanism fixed magnet 62 and a repulsion type magnetic negative stiffness mechanism movable magnet 61, the three magnets are arranged along the X direction, and the repulsion type magnetic negative stiffness mechanism movable magnet 61 is positioned on the two repulsion type magnetic negative stiffness mechanism fixed magnets 62. The two repulsion type magnetic negative stiffness mechanism fixed magnets 62 have the same magnetizing direction and are along the X direction, and are fixedly connected with the base 1 through respective independent repulsion type magnetic group connecting pieces 5. The magnetizing direction of the repulsive force type magnetic negative stiffness mechanism moving magnet 61 is also along the X direction, but is opposite to the magnetizing directions of the two repulsive force type magnetic negative stiffness mechanism fixed magnets 62.

Fig. 6 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in embodiment 3 of the present invention, and referring to fig. 6, it can be seen that, unlike embodiment 1, embodiment 3 employs a set of array type magnetic negative stiffness mechanisms of attraction type and a set of array type magnetic negative stiffness mechanisms of repulsion type to form a combined linear magnetic negative stiffness unit in parallel. The array type attraction type magnetic negative stiffness mechanism is formed by arranging three rows of attraction type magnetic negative stiffness mechanisms side by side, and the magnetizing directions of the magnetic groups between adjacent rows are opposite. The array repulsion type magnetic negative stiffness mechanism is formed by three rows of attraction type magnetic negative stiffness mechanisms in parallel, and the magnetizing directions of the magnetic groups between adjacent rows are opposite.

Fig. 7 is a front view of a near-zero stiffness vibration isolation system including a combined magnetic negative stiffness mechanism in embodiment 4 of the present invention, referring to fig. 7, a magnet part is a cross-sectional view, which is different from embodiment 1 in that embodiment 7 uses a ring magnet to construct a repulsive magnetic negative stiffness mechanism, wherein the attractive magnetic negative stiffness mechanism is composed of an upper ring-shaped attractive magnetic negative stiffness mechanism fixed magnet 42 and a ring-shaped attractive magnetic negative stiffness mechanism movable magnet 41, the three magnets are arranged along the Z direction, the magnetizing directions of the three magnets are the same, and the magnets are all magnetized along the Z direction. Two fixed magnets 42 of the attraction type magnetic negative stiffness mechanism are fixedly connected with the base 1 through the attraction type magnetic group connecting piece 3, and the movable magnet 41 of the attraction type magnetic negative stiffness mechanism is fixedly connected with the load platform 9 through the movable magnet connecting piece 7.

The repulsion type magnetic negative stiffness mechanism 6 is composed of an inner circular ring magnet and an outer circular ring magnet which are coaxially arranged, and is respectively composed of a circular ring repulsion type magnetic negative stiffness mechanism fixed magnet 62 and a circular ring repulsion type magnetic negative stiffness mechanism movable magnet 61. The magnetizing directions of the two circular magnets are radial magnetizing, but the magnetizing directions are opposite. The fixed magnet 62 of the repulsion type magnetic negative stiffness mechanism is fixedly connected with the base 1 through the repulsion type magnetic group connecting piece 5. The repulsion type magnetic negative stiffness mechanism moving magnet 61 is fixedly connected with the load platform 9 through a moving magnet connecting piece 7.

According to the combined magnetic negative stiffness mechanism, the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism are connected in parallel to form the combined magnetic negative stiffness mechanism by utilizing the complementarity of the negative stiffness variation trends of the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism along with relative displacement, the effective working range of the magnetic negative stiffness can be remarkably widened by reasonably matching the parameters of the repulsion type magnetic negative stiffness mechanism and the attraction type magnetic negative stiffness mechanism, the linearity of the magnetic negative stiffness in the working range is improved, the stiffness value of a positive stiffness unit is approached as much as possible, and the vibration isolation effect with near-zero comprehensive stiffness and stable working is realized.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.