Stator misalignment configuration high linearity magnetic negative stiffness mechanism
By using a specific array configuration and initial bias of the stator magnet and the mover magnet, the problems of negative stiffness and linearity in a limited space of the magnetostrictive negative stiffness mechanism are solved, achieving a high linearity vibration isolation effect over a large stroke range, which is suitable for low-frequency vibration isolation in precision manufacturing and measuring equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUAZHONG UNIV OF SCI & TECH
- Filing Date
- 2023-10-20
- Publication Date
- 2026-06-02
AI Technical Summary
Existing magnetostrictive negative stiffness mechanisms are difficult to achieve large negative stiffness values and good linearity over a long stroke range within a limited space, and their complex structures are not easy to implement.
By configuring the stator magnet and the mover magnet in a specific orientation array, and utilizing the initial offset distance and the number of layers and columns of the magnet array, an alternating arrangement is formed to generate negative stiffness characteristics of a repulsive state, ensuring a large negative stiffness value in the z-direction and maintaining linearity over a wide stroke.
It achieves a large negative stiffness value within a limited space, while maintaining good linearity over a wide range of strokes. The structure is simple and easy to implement, making it suitable for low-frequency vibration isolation requirements of large precision manufacturing equipment and precision facilities.
Smart Images
Figure CN117537025B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of vibration isolation, and more specifically, relates to a high linear magnetic negative stiffness mechanism with stator and mover misalignment. Background Technology
[0002] In fields such as precision machining equipment and precision measurement, even minute low-frequency vibrations can adversely affect manufacturing and measurement accuracy. Therefore, effective isolation of low-frequency vibrations is necessary. Linear vibration isolation systems can only isolate external vibrations with frequencies higher than the system's natural frequency. Vibration isolation is only achieved when the frequency is doubled. Therefore, to isolate low-frequency vibrations, the natural frequency of the vibration isolation system needs to be reduced. While maintaining the load capacity of the vibration isolation system, to isolate low-frequency vibrations and expand the isolation frequency bandwidth, the overall stiffness of the system needs to be reduced, thereby lowering the system's natural frequency. Currently, using parallel negative stiffness mechanisms in vibration isolation systems is an effective method to reduce the system's natural frequency.
[0003] Compared to devices that generate negative stiffness characteristics, such as combined springs and linkage mechanisms, magnetostrictive negative stiffness mechanisms have the advantages of being frictionless and contactless. However, the stiffness characteristics generated by the magnetic force between two magnets are nonlinear with respect to the distance between them. This nonlinear stiffness characteristic and the resulting nonlinear dynamics can affect the stability and vibration isolation effect of the vibration isolation system. Therefore, achieving a negative stiffness characteristic with good linearity is the goal that magnetostrictive negative stiffness mechanisms need to achieve.
[0004] In current engineering applications of vibration isolation, achieving a large negative stiffness value in a limited space and having good linearity characteristics over a long stroke range are problems that negative stiffness mechanisms need to solve. However, negative stiffness mechanisms with good linearity are complex and difficult to implement. Therefore, it is necessary to develop a structure that is simple in structure and has good and large magnetic negative stiffness over a long stroke range. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high linear magnetic negative stiffness mechanism with stator and mover misalignment. This mechanism utilizes mover magnets and stator magnets arranged in a specific orientation array, initially biasing the mover magnets in the same layer relative to the stator magnets. By matching appropriate initial bias distances, the number of layers and columns of the magnet array, the entire magnetic negative stiffness mechanism generates a large negative stiffness value in the z-direction and exhibits good linearity in negative stiffness characteristics over a wide stroke range.
[0006] To achieve the above-mentioned objectives, this application provides a high linear magnetic negative stiffness mechanism with stator and mover misalignment, comprising a stator magnet, a mover magnet, a stator frame, and a mover frame. All stator magnets are fixed to the stator frame, and all mover magnets are fixed to the mover frame. Multiple stator and mover magnets are present, and they are arranged in multiple layers and columns.
[0007] In the z-axis direction, stator magnets are arranged in at least one column, and mover magnets are arranged in at least one column, with the stator magnet columns and mover magnet columns alternating. In the x-axis direction, stator magnets and mover magnets are present simultaneously in the same layer, with the stator magnets and mover magnets alternating in the same layer. The number of layers of stator magnets and the number of layers of mover magnets are the same, and each has at least two layers.
[0008] The stator magnets and mover magnets on the same layer have the same excitation direction and the magnetic force is repulsive, which makes the force between the stator magnets and mover magnets in the z-direction exhibit negative stiffness characteristics.
[0009] When the number of layers formed by the stator magnet and the mover magnet is even, the mover magnet in the upper half is offset upwards by a predetermined distance relative to the stator magnet in the same layer, and the mover magnet in the lower half is offset downwards by the same predetermined distance relative to the stator magnet in the same layer.
[0010] When the number of layers formed by the stator magnet and the mover magnet is odd, the mover magnet in the middle layer is level with the stator magnet in the same layer. The mover magnet above the middle layer is offset upwards by a set distance relative to the stator magnet in the same layer, and the mover magnet below the middle layer is offset downwards by the same set distance relative to the stator magnet in the same layer.
[0011] Furthermore, the predetermined distance by which the moving magnet is offset relative to the stator magnet in the same layer is Δh. Δh is related to the horizontal gap Δx between the stator magnet and the moving magnet, the size specifications of the stator magnet, and the size specifications of the moving magnet. The predetermined distance Δh is 0.5 to 3 times the horizontal gap Δx between the stator magnet and the moving magnet, and the predetermined distance Δh does not exceed 0.5 times the thickness of both the stator magnet and the moving magnet. The advantage of this setting is that the magnetic negative stiffness mechanism can simultaneously satisfy the negative stiffness characteristics of a large negative stiffness value and high linearity.
[0012] Furthermore, the stator magnet and the mover magnet are rectangular or cubic in shape, and all stator magnets and mover magnets have the same shape and the same size specifications.
[0013] Furthermore, the stator magnet and the mover magnet are circular. The stator magnets in the same column have the same shape and size specifications, and the mover magnets in the same column have the same shape and size specifications. Within the same layer, the stator magnet and the mover magnet have the same height or thickness, but different ring radii. The mover magnets and stator magnets in the same layer have the same center, and the centers of the mover magnets and stator magnets in different layers are on the same straight line.
[0014] Furthermore, when the stator magnet and the mover magnet are a complete circular ring, the excitation directions of the stator magnet and the mover magnet are simultaneously along the z-direction or simultaneously along the radial direction.
[0015] Furthermore, the annular stator magnet and mover magnet are a combined annular structure composed of multiple tile-shaped magnets that are radially or radially excited.
[0016] Furthermore, the excitation directions of stator magnets and mover magnets in different columns, and between adjacent layers, are either the same or opposite.
[0017] Furthermore, in use, the stator frame is fixedly connected to the vibration isolator frame matched to the outside world or to the vibration source fixedly connected to the vibration isolator frame through a mechanical structure, and the moving frame is fixedly connected to the vibration-isolated equipment through a mechanical structure to the load platform or to the vibration-isolated moving frame of the outside vibration isolator.
[0018] In this application, by arranging the stator magnet and mover magnet in multiple layers, or at least two layers, along the z-axis, or by arranging them alternately in multiple columns along the horizontal direction, the peak value of the negative stiffness can be increased. By generating a suitable initial bias between the mover magnet and the stator magnet in the same layer, the linearity of the negative stiffness characteristics can be effectively improved. The magnetic negative stiffness mechanism of this application can generate a large negative stiffness value while exhibiting good linearity of the negative stiffness characteristics over a relatively wide stroke range.
[0019] In summary, the technical solutions conceived in this application, compared with the prior art, have the following advantages:
[0020] Beneficial effects:
[0021] In this application, by arranging the stator magnets and mover magnets in an array along the z-axis and / or horizontal direction, the number of magnet layers and / or columns can be increased by expanding the array. The stator magnets and mover magnets are arranged alternately in an array along the horizontal direction. Expanding the array to increase the number of magnet columns increases the negative stiffness value at the initial equilibrium position, achieving greater negative stiffness characteristics within a limited space. The forces between stator magnets and mover magnets in each layer are repulsive, resulting in a repulsive negative stiffness characteristic, which is less prone to instability compared to an attractive negative stiffness characteristic mechanism. Furthermore, the stator magnets and mover magnets can form an array along the z-axis. When the number of array layers is odd, the mover magnets in the middle layer are not biased relative to the stator magnets, the mover magnets above the middle layer are biased upwards relative to the stator magnets in the same layer, and the mover magnets below the middle layer are biased downwards relative to the stator magnets in the same layer. When the number of layers of stator and mover magnets arranged in the z-axis is even, the mover magnets in the upper half are biased upwards relative to the stator magnets in the same layer, and the mover magnets in the lower half are biased downwards relative to the stator magnets in the same layer. When the initial upward bias distance of the mover magnet relative to the stator magnet in the same layer along the z-axis is the same as the initial downward bias distance, the upward and downward bias forces cancel each other out, making the z-axis magnetic force generated between all mover magnets and stator magnets zero at the initial equilibrium position. When the initial upward bias distance of the mover magnet relative to the stator magnet in the same layer along the z-axis is not the same as the initial downward bias distance, the z-axis magnetic force generated between all mover magnets and stator magnets at the initial equilibrium position is not zero, which is applicable to situations where an initial force is required at the equilibrium position. By biasing the mover magnet relative to the stator magnet by an appropriate distance, the linearity of the negative stiffness characteristics can be improved to a large extent, achieving a low-frequency vibration isolation effect with a large stroke range.
[0022] Chinese patent application CN113915282A discloses a compact, wide-range, high-linearity magnetic negative stiffness mechanism. This invention improves the linearity of the negative stiffness curve by combining the attractive and repulsive forces generated between the mover magnet and the stator magnet, thus combining the two opposing trends of negative stiffness characteristics. The magnetic negative stiffness mechanism described in this application generates negative stiffness characteristics solely through the repulsive force between the stator magnet and the mover magnet. By generating a suitable initial bias in the z-direction relative to the stator magnet in the same layer, the linearity of the negative stiffness curve is improved. The structure is simple and easy to implement.
[0023] The high linearity magnetic negative stiffness mechanism of this application can achieve a large negative stiffness value in a limited space, while realizing a high linearity negative stiffness characteristic with a large stroke range. The structure of this application is simple, practical, and easy to implement, and can meet the requirements of low-frequency vibration isolation for large-scale precision manufacturing equipment and precision facilities. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of Embodiment 1 of a high linear magnetic negative stiffness mechanism with a stator misalignment provided in this application.
[0025] Figure 2 This is a schematic diagram of Embodiment 2 of a high linear magnetic negative stiffness mechanism with a stator misalignment provided in this application.
[0026] Figure 3 This is a schematic diagram of Embodiment 3 of a high linear magnetic negative stiffness mechanism with a stator misalignment provided in this application.
[0027] Figure 4 This is a schematic diagram of Embodiment 4 of a high linear magnetic negative stiffness mechanism with a stator misalignment provided in this application.
[0028] Figure 5 This is a schematic diagram of Embodiment 5 of a high linear magnetic negative stiffness mechanism with a stator misalignment provided in this application.
[0029] Figure 6 The vertical stiffness-displacement curves of the magnetic negative stiffness mechanism provided in Example 5 under different offset distances Δh.
[0030] Figure 7 This is a schematic diagram of Embodiment 6 of a high linear magnetic negative stiffness mechanism with a stator misalignment provided in this application.
[0031] Figure 8 This is a schematic diagram of a high linear magnetic negative stiffness mechanism with parallel positive stiffness springs provided in Example 1, where the fixed and moving parts are misaligned.
[0032] Figure 9 The vertical stiffness-displacement curves of the single-layer stator magnet and the mover magnet in Example 5 without initial bias are shown.
[0033] Figure 10 This is a vertical stiffness-displacement curve diagram illustrating the principle of generating high linearity negative stiffness in this application. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0036] In the description of this application, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the appendix. Figure 1 The orientations or positional relationships shown are for the purpose of facilitating and simplifying the description of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "installation" should be interpreted broadly. For example, they can refer to a fixed connection or installation, a detachable connection or installation, or an integral connection or installation. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0038] This application proposes a ring-shaped high linearity magnetic negative stiffness mechanism. Through structural and positional design, a high linearity magnetic negative stiffness mechanism is formed, which can generate a large negative stiffness value and has good linearity within a certain stroke range. Moreover, the structure is simple and easy to implement.
[0039] Figure 1 This is a schematic diagram of Embodiment 1 of a high linear magnetic negative stiffness mechanism with a stator-motor misalignment provided in this application. Figure 1 As shown, this embodiment 1 includes a stator frame 1, a stator magnet assembly 2, a mover magnet assembly 3, and a mover frame 4. The stator magnet assembly 2 includes multiple parallel annular stator magnets spaced apart by intervals. There are m annular stator magnets in total, named S1, ... S2. (m+1) / 2 ...S m Together, they constitute the stator magnet assembly 2 and are all fixed to the stator frame 1. The shape of the stator frame 1 can be flexibly designed according to needs. The mover magnet assembly 3 includes multiple parallel annular mover magnets spaced apart, with a total of m annular mover magnets M1, ... M2. (m+1) / 2 ...M mTogether, they constitute the mover magnet assembly 3 and are all fixed to the mover frame 4. The shape of the mover frame 4 can be flexibly designed according to needs. The annular stator magnet has multiple layers, and the annular mover magnet also has multiple layers, with each layer of annular stator magnet and each layer of annular mover magnet alternating. From a macroscopic perspective, in this embodiment, there is only one column of mover magnet assembly and only one column of stator magnet assembly. Stator magnets S1, S2 (m+1) / 2 S m Motor magnets M1 and M (m+1) / 2 M m All are arranged in an array along the z-axis, where m is an odd number and greater than or equal to 3. The thickness of each layer of stator magnets is the same as the thickness of each layer of mover magnets, and the magnetic force in the z-axis is repulsive. The excitation directions between adjacent stator and mover magnets in the z-axis are opposite. The middle layer of mover magnets M... (m+1) / 2 Relative to stator magnet S (m+1) / 2 No bias. Located in the intermediate layer M. (m+1) / 2 All the upper layer moving magnets are biased upwards by Δh relative to the stator magnets in the same layer; the middle layer M (m+1) / 2 All the lower-layer moving magnets are biased downwards by Δh relative to the stator magnets in the same layer. This biasing of the moving magnets relative to the stator magnetic force improves the linearity of the negative stiffness characteristics. Equal upward and downward biases ensure that the net force in the z-direction at the initial equilibrium position is zero. By arranging the moving and stator magnets in an array along the z-direction, and biasing the moving magnets above and below the middle-layer moving magnets upwards and downwards by the same distance relative to the stator magnets in the same layer, it is possible to simultaneously achieve a large negative stiffness value and high linearity in the negative stiffness characteristics.
[0040] Figure 2 This is a schematic diagram of Embodiment 2 of a high linearity magnetic negative stiffness mechanism provided in this application. Figure 2 As shown, this embodiment 2 includes a stator frame 1, a stator magnet assembly 2, a mover magnet assembly 3, and a mover frame 4. The structure of embodiment 2 is similar to that of embodiment 1. The stator magnet assembly 2 includes multiple parallel annular stator magnets spaced apart by intervals. There are m annular stator magnets in total, named S1, ... S2. (m+1) / 2 ...S m Together, they constitute the stator magnet assembly 2 and are all fixed to the stator frame 1. The shape of the stator frame 1 can be flexibly designed according to needs. The mover magnet assembly 3 includes multiple parallel annular mover magnets spaced apart, with a total of m annular mover magnets M1, ... M2. (m+1) / 2 ...M mTogether, they constitute the mover magnet assembly 3 and are all fixed to the mover frame 4. The shape of the mover frame 4 can be flexibly designed according to needs. The annular stator magnet has multiple layers, and the annular mover magnet also has multiple layers, with each layer of annular stator magnet and each layer of annular mover magnet alternating. From a macroscopic perspective, in this embodiment, there is only one column of mover magnet assembly and only one column of stator magnet assembly. Stator magnets S1, S2 (m+1) / 2 S m Motor magnets M1 and M (m+1) / 2 M m All are arranged in an array along the z-axis, where m is an odd number and m is greater than or equal to 3. Each layer of stator magnet has the same thickness, each layer of mover magnet has the same thickness, and the thicknesses of both the mover and stator magnets are also the same. The magnetic force in the z-axis is repulsive. (Compared to Example 1 (attached to the specification)) Figure 1 Unlike the previous embodiment, the excitation directions between adjacent stator and mover magnets in the z-axis are the same. The intermediate layer mover magnet M... (m+1) / 2 Relative to stator magnet S (m+1) / 2 No bias; located in the intermediate layer M (m+1) / 2 All the upper layer moving magnets are biased upwards by Δh relative to the stator magnets in the same layer; the middle layer M (m+1) / 2 All the lower-layer moving magnets are biased downwards by Δh relative to the stator magnets in the same layer. This biasing of the moving magnets relative to the stator magnetic force improves the linearity of the negative stiffness characteristics. Equal upward and downward biases ensure that the net force in the z-direction at the initial equilibrium position is zero. By arranging the magnets in an array along the z-direction, and biasing the moving magnets above and below the middle-layer moving magnets upwards and downwards by the same distance relative to the stator magnets in the same layer, it is possible to simultaneously achieve a large negative stiffness value and high linearity in the negative stiffness characteristics.
[0041] Compared to Example 1, where the excitation directions of adjacent stator and mover magnets in the z-direction are opposite, in Example 2, the excitation directions of adjacent stator and mover magnets in the z-direction are the same. Within a unit space, when the number of magnet array layers in the z-direction is the same, opposite excitation directions of adjacent magnets in the z-direction can generate a larger negative stiffness value compared to having the same excitation direction. Opposite excitation directions of adjacent magnets in the z-direction are a superior magnet arrangement. However, the same excitation direction between adjacent stator and mover magnets in the z-direction in Example 2 also has some advantages. The adjacent stator and mover magnets are attracted to each other, facilitating assembly. When assembling stator and mover magnet assemblies, the magnets can be assembled together without the aid of external force.
[0042] Figure 3 This is a schematic diagram of Embodiment 3 of a high linearity magnetic negative stiffness mechanism provided in this application. Figure 3As shown, this embodiment 3 includes a stator frame 1, a stator magnet assembly 2, a mover magnet assembly 3, and a mover frame 4. The stator magnet assembly 2 includes multiple parallel annular stator magnets spaced apart by intervals. There are n annular stator magnets in total, with n stator magnets S1, ... S2... n / 2 … …S n Together, they constitute stator magnet assembly 2 and are all fixed to stator frame 1. The shape of stator frame 1 can be flexibly designed according to needs. Mover magnet assembly 3 includes multiple parallel annular mover magnets spaced apart, with a total of n annular mover magnets, M1, ... M2. n / 2 ... …M n Together, they constitute the mover magnet assembly 3 and are all fixed to the mover frame 4. The shape of the mover frame 4 can be flexibly designed according to needs. The annular stator magnet has multiple layers, and the annular mover magnet also has multiple layers, with each layer of annular stator magnet and each layer of annular mover magnet alternating. From a macroscopic perspective, in this embodiment, the mover magnet assembly has only one column, and the stator magnet assembly also has only one column. The stator magnets S1, ... S2 n / 2 …
[0043] …S n Motor magnets M1, ... M n / 2 … …M n All magnets are arranged along the z-axis, where n is an even number and greater than or equal to 2. Each layer of stator magnets is identical, and each layer of mover magnets has the same thickness. The mover magnets and stator magnets have the same thickness, and the magnetic force between them in the z-axis is repulsive. Adjacent stator and mover magnets in the z-axis have opposite excitation directions. This arrangement of adjacent magnets with opposite excitation directions in the z-axis results in a greater negative stiffness value compared to co-directional excitation. In the entire structure, both the number of stator magnet layers and the number of mover magnet layers are even. Macroscopically, the mover magnets are located in the upper half. …M n Compared to the stator magnets in the same layer …S n All are biased upwards by Δh, and the moving magnets M1, ... M1 in the lower half are biased upwards by Δh. n / 2 Relative to the stator magnets S1, ... S in the same layer n / 2 A downward bias of Δh is applied. By biasing the mover magnet relative to the stator magnetic force, the linearity of the negative stiffness characteristics can be improved. Equal upward and downward biases ensure that the net force in the z-direction at the initial equilibrium position is zero. By arranging the magnets in an array along the z-direction, and biasing the upper and lower half of the mover magnets upward and downward by the same distance relative to the stator magnets in the same layer, it is possible to simultaneously achieve a large negative stiffness value and high linearity in the negative stiffness characteristics.
[0044] Figure 4 This is a schematic diagram of Embodiment 4 of a high linearity magnetic negative stiffness mechanism provided in this application, as shown below. Figure 4 As shown, this embodiment 4 includes a stator frame 1, a stator magnet assembly 2, a mover magnet assembly 3, and a mover frame 4. The stator magnet assembly 2 includes two layers of parallel, spaced-apart annular stator magnets, and the mover magnet assembly 3 also includes two layers of parallel, spaced-apart annular stator magnets. Macroscopically, in this embodiment, the mover magnet assembly has j columns, and the stator magnet assembly also has i columns. The j columns of mover magnets are spaced-apart and parallel, and the i columns of stator magnets are spaced-apart and parallel. The stator magnets and mover magnets alternate in spacing and are parallel to each other. The two layers of annular stator magnets S... 1,1 ...S 1,i S 2,1 ...S 2,i Together, they constitute stator magnet assembly 2 and are all fixed to stator frame 1. The shape of stator frame 1 can be flexibly designed according to requirements. Two layers of annular mover magnets M 1,1 ...M 1,j M 2,1 ...M 2,j Together, they constitute the mover magnet assembly 3 and are all fixed to the mover frame 4. The shape of the mover frame 4 can be flexibly designed according to requirements. Stator magnet S 1,1 ...S 1,i S 2,1 ...S 2,i Motor magnet M 1,1 ...M 1,j M 2,1 ...M 2,j The stator magnets and mover magnets are arranged in alternating arrays along the horizontal direction, where i and j are the column numbers of the stator magnet and mover magnet arrays, respectively. Both i and j are positive integers, greater than 1. The number of stator magnet arrays and mover magnet arrays can be equal or unequal in the horizontal direction. Each layer of stator magnets has the same thickness, each layer of mover magnets has the same thickness, and the individual mover magnets have the same thickness. The magnetic force between the mover magnets in the z-direction is repulsive. The mover magnet M is located in the second layer. 2,1 ...M 2,j Relative to the second layer of stator magnet S 2,1 ...S 2,i All are biased upwards by Δh, and the moving magnet M is located in the first layer. 1,1 ...M 1,j Relative to the first layer of stator magnet S 1,1 ...S 1,iAll magnets are biased downwards by Δh, resulting in a symmetrical structure. By biasing the mover magnets relative to the stator magnetic force, the linearity of the negative stiffness characteristics can be improved. Equal upward and downward biases ensure that the net force in the z-direction at the initial equilibrium position is zero. By arranging the magnets in a horizontal array, and biasing the second and first layer of mover magnets upwards and downwards by the same distance relative to the stator magnets in the same layer, it is possible to simultaneously achieve a large negative stiffness value and high linearity in the negative stiffness characteristics.
[0045] Furthermore, the stator and mover magnets, which are alternately arranged horizontally in Example 4, can be extended in the z-direction and formed into an array along the z-direction, creating a multi-layered, multi-column magnet arrangement. When the number of array layers in the z-direction is odd, the arrangement pattern of the multi-layered magnets in the z-direction satisfies the arrangement pattern in Example 1 (stator and mover magnets are arranged in an odd number of layers); when the number of array layers in the z-direction is even, the arrangement pattern of the multi-layered magnets in the z-direction satisfies the arrangement pattern in Example 3 (stator and mover magnets are arranged in an even number of layers). By arranging the stator and mover magnets alternately in the horizontal direction and forming an array along the z-direction, a larger negative stiffness value can be achieved in a limited space for the magnetic negative stiffness mechanism. Furthermore, by offsetting the mover magnet relative to the stator magnet in that layer by an appropriate distance, both a larger negative stiffness value and high linearity negative stiffness characteristics can be simultaneously achieved.
[0046] Figure 5 This is a schematic diagram of Embodiment 5 of a high linearity magnetic negative stiffness mechanism provided in this application. Figure 5As shown, this embodiment 5 includes a stator frame 1, a first stator magnet 2a, a second stator magnet 2b, a third stator magnet 2c, a fourth stator magnet 2d, a stator magnet spacing adjustment block 5, a mover magnet bottom end cap 8, a first mover magnet 3a, a second mover magnet 3b, a third mover magnet 3c, a fourth mover magnet 3d, a mover magnet spacing adjustment block 6, a stator frame upper end cap 7, and a mover frame 4. All stator magnets and all mover magnets are annular. The stator magnets and mover magnets in the same layer have the same excitation direction, and the magnetic force is repulsive. The stator magnets and mover magnets in adjacent layers have opposite excitation directions. There are four layers of mover magnets, and there are also four layers of stator magnets. The first stator magnet 2a, the second stator magnet 2b, the third stator magnet 2c, and the fourth stator magnet 2d, the stator frame 1, and the upper end cover 7 of the stator frame together constitute the stator component. The stator frame 1 is fixed to the external vibration isolator base. The first stator magnet 2a, the second stator magnet 2b, the third stator magnet 2c, and the fourth stator magnet 2d are all fixed to the stator frame 1. Stator magnet spacing adjustment blocks 5 are sandwiched between adjacent stator magnets. The spacing between the stator magnets can be changed by changing the thickness of the stator magnet spacing adjustment blocks. The bottom end cover 8 of the mover magnet, the first mover magnet 3a, the second mover magnet 3b, the third mover magnet 3c, the fourth mover magnet 3d, and the mover frame 4 together constitute the mover component. The mover frame connecting block is connected to the external vibration isolator top plate and moves synchronously with the vibration isolator top plate. The first moving magnet 3a, the second moving magnet 3b, the third moving magnet 3c, and the fourth moving magnet 3d are all fixed to the moving magnet frame 4. Moving magnet spacing adjustment blocks 6 are sandwiched between the moving magnets. The spacing between the moving magnets can be changed by altering the thickness of these adjustment blocks. The first moving magnet 3a and the second moving magnet 3b, located in the upper half, are each offset upwards by Δh relative to the first stator magnet 2a and the second stator magnet 2b in the same layer. The third moving magnet 3c and the fourth moving magnet 3d, located in the lower half, are each offset downwards by Δh relative to the third stator magnet 2c and the fourth stator magnet 2d in the same layer. By changing the thickness of the stator magnet spacing adjustment blocks 5 and 6, the offset Δh of the moving magnets relative to the stator magnets in the same layer can be changed, thereby adjusting the magnitude of the negative magnetic stiffness and the linearity of the negative stiffness.
[0047] Figure 6The stiffness-displacement curves of the magnetic negative stiffness mechanism provided in Example 5 under different offset distances Δh are shown. All annular stator magnets have the same specifications and dimensions; that is, the inner radius of the first stator magnet 2a, the second stator magnet 2b, the third stator magnet 2c, and the fourth stator magnet 2d is 15mm, the outer radius is 25mm, and the thickness is 15mm. All annular stator magnets have the same specifications and dimensions; the inner radius of the first mover magnet 3a, the second mover magnet 3b, the third mover magnet 3c, and the fourth mover magnet 3d is 2mm, the outer radius is 12mm, and the thickness is 15mm. The remanent magnetic induction intensity Br of both the stator magnets and the mover magnets is 1.4T. The thickness of the stator magnet spacing adjustment block is 3mm, meaning the spacing between adjacent stator magnets is 3mm. With other conditions remaining unchanged, when the offset Δh between the moving magnet and the stator magnet in the same layer is 0, 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm respectively, the magnetic negative stiffness mechanism moves 5 mm vertically from its initial equilibrium position. The resulting curves of vertical stiffness versus vertical displacement are shown below. Figure 6 As shown. By Figure 6 It can be seen that as the offset Δh gradually increases, the peak value of the vertical negative stiffness gradually decreases. When the offset Δh gradually increases from 0 to 5 mm, the linearity of the vertical negative stiffness curve first gradually improves and then gradually deteriorates. When the offset Δh = 4 mm, the negative stiffness of the vertical stiffness at the equilibrium position is -147 N / mm, and the linearity error of the negative stiffness curve is less than 1% within a stroke range of ±3 mm, exhibiting excellent linearity characteristics.
[0048] Figure 7 This is a schematic diagram of Embodiment 6 of a high linearity magnetic negative stiffness mechanism provided in this application. Figure 7As shown, this embodiment 6 includes a first stator magnet 2a, a second stator magnet 2b, a third stator magnet 2c, a fourth stator magnet 2d, a fifth stator magnet 2e, a sixth stator magnet 2f, a first mover magnet 3a, a second mover magnet 3b, a third mover magnet 3c, a fourth mover magnet 3d, a fifth mover magnet 3e, a sixth mover magnet 3f, a stator frame 1, and a mover frame 4. All stator and mover magnets are cuboid in shape. Viewed from the z-axis, the stator magnets have three layers, and the mover magnets have three layers. The stator magnets and mover magnets in the same layer have the same excitation direction and exhibit a repulsive magnetic force. The stator magnets and mover magnets in adjacent layers have opposite excitation directions. All stator magnets are fixed to the stator frame 1, and all mover magnets are connected to the mover frame 4. The third and fourth moving magnets 3c and 3d, located in the intermediate layer, are at the same height relative to the third and fourth stator magnets 2c and 2d, respectively, and are flush with each other without initial bias. The fifth and sixth moving magnets 3e and 3f, located above the intermediate layer, are both biased upwards by Δh relative to the fifth and sixth stator magnets 2e and 2f, respectively. The first and second moving magnets 3a and 3b, located below the intermediate layer, are both biased downwards by Δh relative to the first and second stator magnets 2a and 2b, respectively. By changing the bias Δh of the moving magnets above and below the intermediate layer relative to the stator magnets, a negative stiffness characteristic with good linearity can be achieved.
[0049] Furthermore, the stator magnet and mover magnet in Example 6 can be extended along the z-direction to form an array, or alternately arranged along the y-direction to form an array, creating a multi-layer, multi-column magnet arrangement. When the number of array layers in the z-direction is odd, the arrangement pattern of the multi-layer magnets in the z-direction satisfies the arrangement form in Example 1, which is an odd-layer arrangement; when the number of array layers in the z-direction is even, the arrangement pattern of the multi-layer magnets in the z-direction satisfies the arrangement form in Example 3, which is an even-layer arrangement. By extending the stator magnet and mover magnet along the z-direction to form an array, or alternatingly arranging them along the y-direction to form a larger array, a larger negative stiffness value can be achieved in a limited space for the magnetic negative stiffness mechanism. Furthermore, by offsetting the mover magnet relative to the stator magnet in that layer by an appropriate distance, both a larger negative stiffness value and high linearity negative stiffness characteristics can be simultaneously satisfied.
[0050] Figure 8 This is a schematic diagram of a high linearity magnetic negative stiffness mechanism connected in parallel with a positive stiffness spring according to Embodiment 1 of this application. As shown in the diagram, due to the instability of the negative stiffness mechanism, it is usually used in parallel with a positive stiffness spring. By connecting the high linearity magnetic negative stiffness mechanism and the positive stiffness spring provided in this application in parallel, a vibration isolation system with large load-bearing characteristics and good low-frequency vibration isolation performance can be constructed, or a quasi-zero stiffness system can be constructed. Figure 8It can be seen that it includes a stator frame 1, a stator magnet assembly 2, a mover magnet assembly 3, a mover frame 4, a vibration isolation load 9, a positive stiffness spring 10, and a base 11. The stator magnets S1, ... S2 are... (m+1) / 2 ...S m Together, they constitute stator magnet assembly 2 and are all fixed to stator frame 1. Stator frame 1 is connected to base 7 and remains stationary. Mover magnets M1, ... M2 (m+1) / 2 ...M m Together, they constitute the mover magnet assembly 3 and are all fixed to the mover frame 4. The mover frame 4 is connected to the vibration isolation load 9 and moves with the vibration isolation load. One end of the positive stiffness spring 10 is connected to the vibration isolation load 9, and the other end is connected to the base 11. The high linearity magnetic negative stiffness mechanism and the positive stiffness spring 10 provided in this application are connected in parallel, which can achieve low-frequency vibration isolation performance without affecting the load-bearing characteristics of the positive stiffness spring. The positive stiffness spring can be in the form of a metal or non-metal mechanical spring, an air spring, etc.
[0051] Furthermore, other embodiments in this application or other high linearity magnetic negative stiffness mechanisms based on the spirit of this application can be connected in parallel with positive stiffness spring mechanisms or devices with positive stiffness characteristics to achieve the effect of improving vibration isolation stability.
[0052] In this application, the stator magnet and the mover magnet exhibit negative stiffness characteristics, which are related to the dimensions of the stator magnet and the mover magnet, the thickness of the stator magnet and the mover magnet, the gap between the stator magnet and the mover magnet in the horizontal direction (x-direction), and the initial offset distance between the stator magnet and the mover magnet in the z-direction. Furthermore, as... Figure 1 As shown, when the offset Δh of the moving magnet relative to the stator magnet in the same layer is (0.1 to 0.5) times the thickness h of the moving magnet or stator magnet in that layer, and when the offset Δh is (0.5 to 3) times the horizontal gap Δx between the stator magnet and the moving magnet, and when the horizontal gap Δx between the stator magnet and the moving magnet is (0.1 to 0.4) times the cross-sectional width of the stator magnet (R4-R3) or the cross-sectional width of the moving magnet (R2-R1), the negative stiffness peak value is larger and the linearity of the negative stiffness curve is better. Here, R4 refers to the outer radius of the stator magnet, R3 refers to the inner radius of the stator magnet, R2 refers to the outer radius of the moving magnet, and R1 refers to the inner radius of the moving magnet.
[0053] To further explain the principle of generating high linearity negative stiffness in this application, the high linearity negative stiffness in Embodiment 5 of this application is analyzed, such as... Figure 9As shown, when the single-layer moving magnet has no initial bias relative to the stator magnet, the vertical stiffness curve generated by the repulsive magnetic force has strong nonlinear characteristics, exhibiting a concave curve shape. At the equilibrium position, the negative stiffness is -40 N / mm, and the linearity error of the negative stiffness curve within a stroke range of ±3 mm is 31%. In Example 5, when the first moving magnet 3a is biased upwards by 4 mm relative to the first stator magnet 2a, the negative stiffness curves of the first moving magnet 3a and each stator magnet within a displacement stroke range of -5 mm to 5 mm, due to the magnetic force, are as follows: Figure 10 As shown in the legend "Layer 1". When the second moving magnet 3b is offset upwards by 4mm relative to the second stator magnet 2b, the negative stiffness curves of the second moving magnet 3b and each stator magnet within the displacement stroke of -5mm to 5mm due to magnetic force are as follows. Figure 10 As shown in the legend "Layer 2". When the third moving magnet 3c is offset downwards by 4mm relative to the second stator magnet 2c, the negative stiffness curves of the third moving magnet 3c and each stator magnet within the displacement stroke of -5mm to 5mm due to magnetic force are as follows. Figure 10 As shown in the legend "Layer 3". When the fourth moving magnet 3d is offset downwards by 4mm relative to the second stator magnet 2d, the negative stiffness curves of the fourth moving magnet 3d and each stator magnet within the displacement stroke of -5mm to 5mm due to magnetic force are as follows. Figure 10 As shown in the legend "Layer 4". When the first moving magnet 3a and the second moving magnet 3b are initially offset upwards by 4mm relative to the first stator magnet 2a and the second stator magnet 2b, respectively, it can be seen that in the vertical stiffness-displacement diagram, the minimum peak value of the stiffness "concave" curves of "Layer 1" and "Layer 2" shifts to the left. Similarly, when the third moving magnet 3c and the fourth moving magnet 3b are initially offset downwards by 4mm relative to the third stator magnet 2c and the fourth stator magnet 2d, respectively, it can be seen that in the vertical stiffness-displacement diagram, the minimum peak value of the stiffness "concave" curves of "Layer 3" and "Layer 4" shifts to the right. By superimposing the stiffness curves of each layer, a stiffness curve with good linearity can be generated over a large stroke range. The total negative stiffness curve generated by the magnetic force between all moving magnets and all stator magnets is shown in the figure. Figure 10 The figure shows the "Total Negative Stiffness". As can be seen from the figure, the negative stiffness of the "Total Negative Stiffness" curve at the equilibrium position is -147 N / mm. Within a stroke range of ±3 mm, the linearity error of the negative stiffness curve is less than 1%, exhibiting excellent linearity characteristics. Therefore, by arranging the magnets in an array along the z-axis, and offsetting the mover magnets above and below the middle layer mover magnets by the same upward and downward distances relative to the stator magnets in the same layer, it is possible to simultaneously achieve a large negative stiffness value and high linearity.
[0054] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A high linear magnetic negative stiffness mechanism with stator and mover misaligned configuration, characterized in that, It includes stator magnets, mover magnets, stator frames, and mover frames. All stator magnets are fixed to the stator frames, and all mover magnets are fixed to the mover frames. There are multiple stator magnets and mover magnets, which are arranged in multiple layers and columns. In the z-axis direction, stator magnets are arranged in columns, and mover magnets are also arranged in columns. The stator magnets are arranged in at least one column, and the mover magnet columns are arranged alternately. In the x-axis direction, both stator magnets and mover magnets are present in the same layer, with alternating layers. The number of stator magnet layers and the number of mover magnet layers are the same, and each has at least two layers. The stator magnets and mover magnets on the same layer have the same excitation direction and the magnetic force is repulsive, which causes the force between the stator magnets and mover magnets in the z-axis direction to exhibit negative stiffness characteristics. When the number of layers formed by the stator magnet and the mover magnet is even, the mover magnet in the upper half is offset upwards by a predetermined distance relative to the stator magnet in the same layer, and the mover magnet in the lower half is offset downwards by the same predetermined distance relative to the stator magnet in the same layer. When the number of layers formed by the stator magnet and the mover magnet is odd, the mover magnet in the middle layer is level with the stator magnet in the same layer. The mover magnet above the middle layer is offset upwards by a set distance relative to the stator magnet in the same layer, and the mover magnet below the middle layer is offset downwards by the same set distance relative to the stator magnet in the same layer.
2. The high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 1, characterized in that, The set distance at which the moving magnet is biased relative to the stator magnet in the same layer is: , Horizontal gap between stator magnet and mover magnet x, the size specifications of the stator magnet, and the size specifications of the mover magnet are all related, and the set distance is... The horizontal gap between the stator magnet and the mover magnet x is 0.5 to 3 times, and the set distance At the same time, the horizontal gap between the stator magnet and the mover magnet shall not exceed 0.5 times the thickness of the stator magnet and 0.5 times the thickness of the mover magnet. x is greater than 0.
3. The high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 2, characterized in that, The stator magnet and the mover magnet are rectangular parallelepipeds, and all stator magnets and mover magnets have the same shape and size.
4. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 2, characterized in that, The stator magnet and the mover magnet are cubic in shape, and all stator magnets and mover magnets have the same shape and size.
5. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 2, characterized in that, The stator magnet and the mover magnet are circular. The stator magnets in the same column have the same shape and size specifications, and the mover magnets in the same column have the same shape and size specifications. Within the same layer, the stator magnets and the mover magnets have the same height or thickness, but different ring radii. The centers of the mover magnets and stator magnets in the same layer are on the same straight line, and the centers of the mover magnets and stator magnets in different layers are also on the same straight line.
6. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 5, characterized in that, When the stator magnet and the mover magnet are a circular ring, the excitation directions of the stator magnet and the mover magnet are simultaneously along the z-axis or simultaneously along the radial direction.
7. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 5, characterized in that, The ring-shaped stator magnet and mover magnet are a combined ring structure consisting of multiple tile-shaped magnets that are excited radially.
8. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 5, characterized in that, The annular stator magnet and mover magnet are a combined annular structure consisting of multiple radially excited tile-shaped magnets surrounding each other.
9. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 1, characterized in that, The excitation directions of stator magnets and mover magnets in different columns and between adjacent layers are the same or opposite.
10. A high linear magnetic negative stiffness mechanism with stator misalignment as described in any one of claims 1-9, characterized in that, The stator magnet and the mover magnet are fixed on the stator frame and the mover frame respectively, and the fixing method is adhesive. The stator magnet and the mover magnet are permanent magnets or equivalent magnets formed by electromagnetic means.
11. A high linear magnetic negative stiffness mechanism with stator and mover misalignment as described in claim 10, characterized in that, In use, the stator frame is fixedly connected to the vibration isolator frame matched to the outside world or to the vibration source fixedly connected to the vibration isolator frame through a mechanical structure, and the moving frame is fixedly connected to the vibration-isolated equipment through a mechanical structure to the load platform or to the vibration isolator moving frame fixedly connected to the outside vibration isolator.