A nonlinear variable stiffness double-sided plate eddy current damper

Abstract

The application belongs to the technical field of structural vibration control, and specifically designs a nonlinear variable stiffness double-plate eddy current damper. The nonlinear variable stiffness double-plate eddy current damper comprises a compression spring component, a plate-type eddy current damping element and an additional iron plate. The compression spring component is composed of a pre-compression spring, a telescopic rod in the pre-compression spring, a square pin connecting two ends of the telescopic rod and bearings at two ends of the square pin. The plate-type eddy current damping element is composed of a pair of permanent magnet groups, a conductor circular plate and a magnetic conductive circular plate. The nonlinear variable stiffness eddy current damper is realized by changing different positions of the spring through a gear, and is further suitable for wide-frequency vibration reduction of multiple modes.

Description

Technical Field

[0001] The invention belongs to the field of structural vibration control technology, and specifically relates to a nonlinear variable stiffness double-sided plate eddy current damper made using a conductor circular plate, a pre-compressed spring component, and a small gear. Background Technology

[0002] In the field of structural vibration control, common damping devices are usually traditional viscous or viscoelastic dampers. However, these dampers have some problems, such as easy leakage, low durability, and difficulty in adjusting damping parameters later. To solve these problems, eddy current dampers have become an effective choice. Eddy current dampers have many advantages, including non-contact operation, low friction, easy maintenance, long life, simple working principle, convenient control, high reliability, and no environmental pollution. Eddy current dampers utilize the principle of electromagnetic induction. When a conducting circular plate cuts magnetic field lines, eddy currents are generated in the conducting circular plate. The eddy currents interact with the original magnetic field, and the resulting Lorentz force opposes the motion of the conducting circular plate. At the same time, the conducting circular plate converts kinetic energy into heat energy through the eddy current effect and dissipates it. Currently, eddy current dampers are widely used in aerospace structures, automotive vibration reduction, braking, and vibration control of rotating mechanisms, but their application in civil engineering is relatively limited.

[0003] In recent years, with in-depth research on the damping performance of eddy current dampers, various structural forms have emerged, such as plate type, rack and pinion type, ball screw type, horizontal slide rail type, vertical support type, and pendulum type. Traditional linear dampers typically only reduce vibration at a single frequency or a specific narrow frequency range. However, the frequency characteristics of the vibrating structure and external excitation often change over time, which can reduce the damping effect of the damper or even exacerbate the vibration of the structure. By employing nonlinear dampers and adjusting the position of the spring through gears to achieve a nonlinear variable stiffness system, it is applicable to multimodal broadband vibration reduction, thus overcoming the limitation of traditional dampers in controlling only one frequency. Furthermore, compared with the energy dissipation of the eddy current effect of a single-sided conductor plate, the eddy current effect of a double-conductor circular plate can dissipate energy more rapidly. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a nonlinear eddy current damper. It employs a nonlinear preloaded spring component and adjusts the spring's position via gears to achieve different nonlinear stiffnesses, enabling broadband vibration reduction across multiple modes. Simultaneously, the magnetic poles of adjacent magnets in each permanent magnet group are alternately arranged in opposite directions, and the conductor plates on both sides of the magnetically conductive circular plate reciprocate, resulting in higher eddy current energy dissipation within the same time frame compared to a single-sided plate design. Furthermore, the use of gear meshing ensures smooth transmission of rotational and heavy loads during the reciprocating linear motion of the conductor plates.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a variable stiffness double-sided plate nonlinear eddy current damper, comprising a compression spring assembly, an eddy current damping element, an iron plate, and a hollow sleeve plate. The compression spring assembly includes a compression spring, a telescopic connecting rod, a bearing, a square pin, and several small gears. Specifically, the telescopic rod, with a diameter slightly smaller than the compression spring, is placed inside the compression spring; the two cylindrical ends of the square pin are connected to the bearing, and the upper and lower ends of the compression spring are respectively connected to the square plane of the square pin.

[0007] Furthermore, four sets of small gears are connected to the four bearing ends of the compression spring assembly. Since the small gears are connected to the bearings, the small gears and the assembly can rotate independently in the plane.

[0008] Furthermore, the eddy current damping element includes a pair of circular gear conductor plates, a magnetic conductive plate, a pair of magnet assemblies, a pair of internal meshing gears, and a pair of auxiliary iron plates. The pair of conductor plates are respectively fixed to both sides of the magnetic conductive plate by screws, and the centers of the three are horizontally collinear.

[0009] Furthermore, the conductor disc is made of a conductive material; the magnetic disc is made of a magnetic material.

[0010] Furthermore, each magnet group uses permanent magnets, and each group of magnets is uniformly fixed to its additional iron plate. The number of magnets in each magnet group is 4n, where n≥1. The magnet groups are centrally symmetrically distributed on the additional iron plate, and the distance d between individual magnets is ≤80mm. The magnetic poles of adjacent magnets in the permanent magnet groups are alternately placed in opposite directions.

[0011] Furthermore, the guide plate assembly and four compression spring assemblies are engaged together in the four directions of up, down, left, and right via small gears, while the other end of the compression spring assembly is connected to a pair of internal meshing gears.

[0012] Furthermore, the internal meshing gear is connected and combined with the hollow sleeve. The hollow sleeve is a hollow cuboid, and the diameter of the front and rear hollow circles is the same as the diameter of the internal meshing gear.

[0013] Furthermore, the additional iron plate assembly is fixed on both sides of the hollow sleeve assembly by means of the iron plate and the side iron plate, and sufficient gaps are left between the additional iron plate and the conductor round plate assembly.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] This invention excels in multimodal broadband vibration control, possessing numerous advantages such as simple structure, convenient installation and maintenance, long lifespan, and no pollution.

[0016] The damping coefficient of the eddy current damper of the present invention can be adjusted by adjusting the number and spacing of permanent magnets, the magnetic field strength of permanent magnets, and the thickness of the magnetic conductive plate.

[0017] The nonlinear eddy current damper of the present invention utilizes a compression spring component and changes the position of the spring through gears to achieve nonlinear variable stiffness. It can be applied to wide frequency vibration reduction, making up for the shortcomings of traditional dampers that are only suitable for single frequency vibration suppression. At the same time, the double-sided conductor plate can further improve the energy dissipation and vibration reduction efficiency of the eddy current damper. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a nonlinear variable stiffness double-sided plate eddy current damper according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of a nonlinear variable stiffness double-sided plate eddy current damper according to an embodiment of the present invention;

[0021] Figure 3 This is a partial structural schematic diagram of a nonlinear variable stiffness double-sided plate eddy current damper according to an embodiment of the present invention.

[0022] The numbers in the diagram represent the following: 1. Connecting component, 2. Iron plate, 3. Side iron plate, 4. Internal meshing gear, 5. Permanent magnet assembly, 6. Conductor round plate, 7. Magnetic conducting round plate, 8. Compression spring, 9. Telescopic rod, 10. Connecting bearing, 11. Small gear, 12. Hollow sleeve, 13. Additional iron plate, 14. Square pin. Detailed Implementation

[0023] The following is a detailed description of the embodiments of this application, wherein the accompanying drawings illustrate examples of the embodiments, and the same reference numerals are used to denote the same or functionally identical components. It should be noted that these embodiments are merely for explaining this application and not for limiting it. Based on the embodiments of this invention, those skilled in the art can obtain all other embodiments without creative effort, and these embodiments all fall within the protection scope of this invention.

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0025] This embodiment of a variable stiffness nonlinear eddy current damper includes a compression spring assembly, a plate-type eddy current damping element, a small gear set 11, and an additional iron plate 13. The compression spring assembly includes a compression spring 8, a telescopic connecting rod 9, a square pin 14, a bearing 10, and a gear set 11. The diameter of the telescopic rod is slightly smaller than that of the compression spring and is placed inside the compression spring. The cylinders at both ends of the square pin are connected to the bearing, and the upper and lower ends of the compression spring 8 are respectively connected to the square plane of the square pin 14.

[0026] The compression spring assembly meshes with the gears on the conductor disc 6 via the gear set 11.

[0027] The plate-type eddy current damping element includes left and right conductor circular plates 6, magnetic conductive circular plates 7, left and right permanent magnet groups 5, left and right internal meshing gears 4, and a pair of additional iron plates 13. The two conductor circular plates 6 are fixed to the left and right sides of the magnetic conductive circular plates 7, and the three are located in the middle of the hollow sleeve 12. The internal meshing gears 4 are embedded on both sides of the hollow sleeve 12. The permanent magnet groups 5 each have 4n magnets, where n≥1, and in this example, n is 1. The permanent magnet groups 5 are centrally symmetrically distributed on the additional iron plates 13, with adjacent magnets having opposite magnetic pole directions, and the spacing d between individual magnets ≤80mm, which is 20mm in this example.

[0028] The conductor disc 6 is made of a material with good electrical conductivity, such as electrical copper; the magnetic disc 7 is made of a material with good magnetic conductivity, such as low carbon steel; the permanent magnet assembly 5 uses N50 type NdFeB permanent magnets with dimensions of 100mm×100mm×15mm.

[0029] In this example, the distance between the permanent magnet assembly 5 and the conductor circular plate 6 is 20mm. In this example, the additional iron plate 13 is 500mm×500mm×25mm. The diameter of the internal meshing gear 4 is 450mm. In this example, the diameters of the conductor circular plate 6 and the magnetic conductive circular plate 7 are both 220mm. The thickness of the conductor circular plate 6 is 15mm, and the thickness of the magnetic conductive circular plate 7 is 20mm. In this example, the hollow sleeve 12 is 500mm×500mm×50mm.

[0030] The hollow sleeve 12 is fixed to the left and right sides of the middle of the side iron plate 3 respectively; iron plates 2 are fixed to the upper and lower sides of the hollow sleeve 12.

[0031] The working principle of the variable stiffness nonlinear eddy current damper is as follows:

[0032] The damper's upper and lower connecting components 1 are connected to the structure and transmit motion. The damper moves along with the external structure. Simultaneously, the conductor circular plate 6 and the magnetic circular plate 7 within the damper undergo relative motion with the permanent magnet assembly 5 due to inertia. The conductor circular plates 6 on both sides of the magnetic circular plate cut the magnetic field lines of the permanent magnet assembly 5, generating eddy currents, thus producing eddy current damping force and heat energy opposite to the direction of the conductor circular plate's motion. The compression spring 8 in the compression spring component changes its compression amount due to the change in the position of the conductor circular plate 6. At this time, the spring's restoring force can suppress the combined motion of the conductor circular plate 6 and the magnetic circular plate 7. Furthermore, the spring's position can be manually changed via a knob on the small gear 11, achieving nonlinear variable stiffness of the damper.

[0033] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used only to explain this application, and not to limit this application. The scope of protection of the present invention is not limited thereto. Any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.

Claims

1. A nonlinear variable stiffness double-sided plate eddy current damper, mainly composed of a permanent magnet, a conductor plate, a gear set, and a compression spring assembly, is characterized in that... Includes compression spring assemblies and eddy current damping elements; The eddy current damping element includes permanent magnets and a conductor disc. The permanent magnets are arranged in an array, and the conductor disc is arranged parallel to the permanent magnets with an air gap. The compression spring assembly includes a compression spring, a telescopic connecting rod, bearings, a square pin, and several small gear sets. The telescopic connecting rod of the compression spring assembly is placed inside the compression spring and has a diameter slightly smaller than the compression spring. The two cylindrical ends of the square pin are connected to the bearings, and each bearing is fixed to a small gear. The upper and lower ends of the compression spring are then connected to the square plane of the square pin.

2. The nonlinear variable stiffness double-sided plate eddy current damper according to claim 1, characterized in that, The eddy current damping element includes a pair of circular gear conductor plates, a magnetic conductive plate, a permanent magnet, a pair of internal meshing gears, and a pair of additional iron plates; the pair of conductor plates are respectively fixed on both sides of the magnetic conductive plate, and the centers of the three are horizontally collinear.

3. A nonlinear variable stiffness double-sided plate eddy current damper according to claim 2, characterized in that, The permanent magnets are uniformly fixed on the additional iron plate, and the number of permanent magnets is 4n, where n≥1; the permanent magnets are centrally symmetrically distributed on the additional iron plate, and the magnetic poles of adjacent permanent magnets are opposite.

4. A nonlinear variable stiffness double-sided plate eddy current damper according to claim 3, characterized in that, The conductor disc is made of a conductive material; the magnetic disc is made of a magnetic material.

5. A nonlinear variable stiffness double-sided plate eddy current damper according to claim 4, characterized in that, The conductor disc is engaged with four compression spring assemblies in four directions (up, down, left, and right) via small gears, while the other end of the compression spring assembly is connected to a pair of internal meshing gears.

6. A nonlinear variable stiffness double-sided plate eddy current damper according to claim 5, characterized in that, The internal meshing gear is connected and combined with the hollow sleeve; the hollow sleeve is a hollow cuboid with the diameter of the front and rear hollow circles being the same as the diameter of the internal meshing gear; the combination of permanent magnet and additional iron plate is fixed on both sides of the hollow sleeve combination, and a certain gap is left between it and the conductor circular plate combination.

7. A nonlinear variable stiffness double-sided plate eddy current damper according to claim 6, characterized in that, The upper and lower connecting components of the damper are connected to the vibrating structure and move together. At the same time, the conductor circular plate and the magnetic circular plate in the damper move relative to the permanent magnet group in the damper due to inertia. As a result, the conductor circular plates on both sides of the magnetic circular plate cut the magnetic field lines of the permanent magnet group to generate eddy currents, which in turn generate eddy current damping force and heat energy in the opposite direction to the movement of the conductor circular plates. In the compression spring component, the position of the spring can be manually changed by a small gear, thereby changing the nonlinear stiffness of the entire damper system and thus achieving wide-frequency vibration reduction.

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