A damper-adjustable negative stiffness electromagnetic damper device

Abstract

This invention relates to the field of structural vibration control technology, and more particularly to a negative stiffness electromagnetic damping device with adjustable damping. It includes a permanent magnet DC motor, a linear drive conversion system, a sliding rheostat, wires, and a gearbox disposed between the motor and the linear drive conversion system. The gearbox includes a housing, a cover plate, and internally meshed double-layer helical gear assemblies and a reversing gear assembly. The reversing gear assembly includes reversing gears of helical gears and bevel gears with equal pitch circles, and a low-speed transmission shaft coaxial with the reversing gears. A sliding rheostat is provided between the two sets of motors. A linear drive conversion system, including a drive gear assembly and a spur rack, is provided between the two sets of gearboxes. This invention provides negative stiffness while generating considerable damping for energy dissipation, achieving a dual control strategy of structural displacement and absolute acceleration effects, and is pre-adjusted through the sliding rheostat.

Description

Technical Field

[0001] This invention relates to the field of structural vibration control technology, and in particular to a negative stiffness electromagnetic damping device with adjustable damping. Background Technology

[0002] Seismic isolation technology is an important way to effectively reduce the seismic response of structures. It works by extending the natural period of the structure so that the fundamental frequency of the structure is outside the high-energy frequency range of the seismic motion, which can effectively improve the structure's seismic resistance and disaster reduction capabilities.

[0003] However, in rare earthquakes, the isolation layer may undergo significant displacement. Excessive displacement of the isolation layer may lead to an enhanced mechanical behavior. The traditional solution is to add damping to the isolation layer to control its displacement. However, this increases the absolute acceleration response of the superstructure. The increase in absolute acceleration brings two problems: first, it significantly reduces the isolation effect of the superstructure; second, it increases the overturning moment of the isolation layer, causing the bearings to exceed their tensile limits.

[0004] Negative stiffness damping, as a vibration reduction device, can effectively solve the above-mentioned problems. The damping provided by negative stiffness damping can control the displacement of the isolation layer, and the resulting negative stiffness characteristics can reduce the acceleration response of the structure, realizing a dual control strategy of displacement and acceleration. Therefore, it is urgent to propose a new negative stiffness damping technology to solve the problems existing in the current technology. Summary of the Invention

[0005] To address the aforementioned deficiencies in existing technologies, this invention provides an adjustable negative stiffness electromagnetic damping device to solve the problem of increased response in the superstructure of the seismic isolation structure due to damping of the isolation layer.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An adjustable negative stiffness electromagnetic damping device includes a permanent magnet DC motor, a linear drive conversion system, a sliding rheostat, and a speed-changing gearbox. The gearbox includes a housing, a cover plate, and a double-layer helical gear assembly and a reversing gear assembly that mesh with each other inside. The double-layer helical gear assembly includes double-layer helical gears of different sizes and a high-speed drive shaft that is coaxial with the double-layer helical gears and connected to them by rotating bearings at both ends. The reversing gear assembly includes a reversing gear of a helical gear and a bevel gear with the same pitch circle, and a low-speed drive shaft that is coaxial with the reversing gear. Two rotating bearings that are spaced apart are provided at the end of the low-speed drive shaft. A sliding rheostat is provided between the two sets of permanent magnet DC motors. The two ends of the sliding rheostat are connected in series with the permanent magnet DC motors through wires to form a closed circuit. The range of the circuit resistance is from the sum of the inherent resistances of the two sets of permanent magnet DC motors to the sum of the inherent resistances of the two sets of permanent magnet DC motors and the maximum resistance of the sliding rheostat. A linear drive conversion system is provided between the multiple sets of the aforementioned gearboxes. The linear drive conversion system includes a drive gear assembly and a spur rack. The drive gear assembly includes a drive gear composed of bevel gears and spur gears, and a transmission shaft coaxial with the drive gear and perpendicular to the reversing gear. The spur rack meshes with the spur gear of the drive gear through a limiting device. The limiting device includes two shaft supports that are spaced apart from each other and are respectively connected to a gearbox. A transmission shaft and a rotating bearing are provided between the shaft supports, and the rotating bearing is in contact with the groove of the spur rack. In the double-layer helical gear, the large-pitch helical gear meshes with the helical gear of the permanent magnet DC motor spindle in the same plane, the small-pitch helical gear meshes with the helical gear of the reversing gear in the same plane, the bevel gear in the reversing gear meshes with the bevel gear in the driving gear in a vertical plane, and the spur gear of the driving gear meshes with the spur rack. This structure can amplify the output speed by a factor of two based on the input speed, while also enabling the high-speed rotating components to generate inertial forces and obtain negative stiffness characteristics.

[0007] Furthermore, the central axis of the main shaft of the permanent magnet DC motor, the central axis of the double-layer helical gear in the gearbox, and the central axis of the commutating gear assembly are all in the same plane. The central axis of the main shaft of the permanent magnet DC motor is collinear with the central axis of the commutating gear assembly, and the central axis of the commutating gear is perpendicular to the central axis of the drive gear. The central axis of the spur rack is perpendicular to the central axis of the drive gear and parallel to the central axis of the main shaft of the permanent magnet DC motor.

[0008] Furthermore, the gears included in the double-layer helical gear assembly, the reversing gear assembly, and the drive gear assembly are all set to the same module; the small-pitch helical gear in the double-layer helical gear assembly has the same pitch circle diameter as the helical gear of the permanent magnet DC motor spindle; the large-pitch helical gear in the double-layer helical gear assembly has the same pitch circle diameter as the helical gear in the reversing gear assembly.

[0009] Furthermore, the high-speed and low-speed drive shafts are respectively bonded and fixed to the inner ring of the rotating bearing using chemical adhesives to restrict axial movement between the rotating shaft and the rotating bearing.

[0010] Furthermore, in order to restrict the movement of the rotating bearing in directions other than its rotation direction, the rotating bearings of the double-layer helical gear assembly and the reversing gear assembly are embedded inside the plate of the housing. The gearbox has at least one pair of set bolts in the radial direction of each rotating bearing to restrict the relative movement between the outer ring of the rotating bearing and the housing.

[0011] Furthermore, the spacing between multiple gearboxes is matched with the distance between the drive gear and the bevel gear; multiple gearboxes are connected in parallel to achieve multiple damping, and the arrangement of the multiple gearboxes follows the principle of symmetry.

[0012] Furthermore, in order to limit the relative movement of the internal components of the limiting device, the transmission shaft in the limiting device is bonded and fixed to the shaft support and the inside of the rotating bearing by chemical adhesive.

[0013] Furthermore, in order to ensure that the spur rack and the spur gear in the drive gear are on the same working plane, the groove of the spur rack is in tangential contact with the outer circle of the rotating bearing of the limiting device.

[0014] Furthermore, the gearbox has right-angle fixed supports on both sides and is connected by bolts. One right-angle fixed support is connected to the permanent magnet DC motor by bolts, and the other right-angle fixed support is fixedly connected to the external component by bolts as a fixed end. The bottom of the rack is provided with a linear drive shaft and is fixed to the housing by a linear bearing.

[0015] The aforementioned adjustable negative stiffness electromagnetic damping device is applied as a whole in the isolation layer of the seismic isolation structure.

[0016] Compared with the prior art, this application has the following advantages: This invention provides an adjustable negative stiffness electromagnetic damping device, comprising a permanent magnet DC motor, a right-angle fixed support, a linear drive conversion system, a sliding rheostat, wires, and a gearbox disposed between the motor and the linear drive conversion system. The adjustable negative stiffness electromagnetic damping device has the following advantages: 1. The negative stiffness characteristic is mainly provided by the inertial mass of the gears in the gearbox and the inertial mass of the rotor in the permanent magnet DC motor. The inertial capacity coefficient depends on the rotor mass, gear mass and the pitch circle radius ratio of the double-layer helical gear. A relatively small mass can provide a considerable and stable inertial capacity coefficient, which is a speed-dependent negative stiffness characteristic. 2. The spur rack can amplify the rotational speed of the rotor in a permanent magnet DC motor by multiple times through the drive gear and the gearbox, so that it is subjected to electromagnetic force during the cutting of magnetic field lines and thus generates damping force. Under the condition that the resistance is kept constant in the closed loop, it is positively correlated with the speed of motion, and can provide a hysteresis model of viscous damping characteristics. Electromagnetic damping makes up for the shortcomings of traditional viscous damping devices such as easy leakage and maintenance. 3. The damping force can be adjusted by adjusting the external sliding rheostat or other resistive elements in series, which satisfies the ability to adjust it on-site to achieve the required equivalent viscous damping coefficient. At the same time, the electrical energy in the operation of the damping device can also be converted into other forms of energy, which further provides new ideas for the design of variable damping and semi-active control. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application. For example, based on the technical concepts disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, and size ratios of certain units (components).

[0018] Figure 1 This is a front view of the negative stiffness electromagnetic damping device provided in this application in one embodiment (with the cover plate on one side of the gearbox hidden). Figure 2 This is a three-dimensional structural diagram of the negative stiffness electromagnetic damping device provided in this application from one perspective in one embodiment (hiding the cover plate on one side of the gearbox). Figure 3 This is a schematic diagram of the gearbox and right-angle fixed support of the negative stiffness electromagnetic damping device provided in this application in one embodiment (hiding one side cover of the gearbox). Figure 4 This is a schematic diagram of the linear drive conversion system of the negative stiffness electromagnetic damping device provided in this application in one embodiment. Figure 5 This is a schematic diagram of the permanent magnet DC motor of the negative stiffness electromagnetic damping device provided in this application in one embodiment. Figure 6 This is a schematic diagram of the double-layer helical gear assembly structure in the gearbox of the negative stiffness electromagnetic damping device provided in this application in one embodiment. Figure 7 This is a schematic diagram of the reversing gear assembly in the gearbox of the negative stiffness electromagnetic damping device provided in this application, in one embodiment. Figure 8 This is an example of the test results of the negative stiffness electromagnetic damping device provided in this application under hysteretic loading with different total resistance values ​​of closed loops under a sinusoidal loading period of 10 seconds. Figure 9This is an example of the test results of the negative stiffness electromagnetic damping device provided in this application under the condition that the total resistance of the closed loop is always 10 ohms, with different sinusoidal periodic hysteretic loading. Figure 10 This is an example diagram of the installation and application of the negative stiffness electromagnetic damping device provided in this application in one embodiment (hiding the panel on one side of the housing and the cover on one side of the gearbox).

[0019] Figure label: 1. Permanent magnet DC motor; 2. Housing; 3. Cover plate; 4. Double-layer helical gear; 5. Reversing gear; 6. Spur rack; 7. Sliding rheostat; 8. Wire; 9. Right-angle fixed support; 10. Shaft support; 11. Rotary bearing; 12. Drive shaft; 13. Drive gear; 14. Housing; 15. Linear bearing; 16. Linear drive shaft; 17. Negative stiffness electromagnetic damping device. Detailed Implementation

[0020] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0022] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to facilitate intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationships in the actual product. Changes in these relative positional relationships, without departing from the technical concept disclosed in this application, should also be considered within the scope of this application.

[0023] Example 1 The following is in conjunction with the appendix Figure 1-10 The structure and working principle of the adjustable negative stiffness electromagnetic damping device provided by the present invention are further explained.

[0024] See Figure 1 The present embodiment of a damping adjustable negative stiffness electromagnetic damping device includes a permanent magnet DC motor 1, a linear drive conversion system, a sliding rheostat 7, and a speed change gearbox.

[0025] like Figure 1-3As shown, the transmission gearbox includes a housing 2, a cover plate 3, and internally meshed double-layer helical gear assemblies and reversing gear assemblies. The double-layer helical gear assembly includes double-layer helical gears 4 of different sizes and a high-speed drive shaft 12 coaxial with the double-layer helical gears 4 and connected to them by rotating bearings 11 at both ends. The reversing gear assembly includes a helical gear 100 with the same pitch circle, a reversing gear 5 of a bevel gear 200, and a low-speed drive shaft 12 coaxial with the reversing gear 5. Two relatively spaced rotating bearings 11 are provided at the ends of the low-speed drive shaft 12.

[0026] like Figure 1-2 As shown, a sliding rheostat 7 is provided between the two sets of permanent magnet DC motors 1. The two ends of the sliding rheostat 7 are connected in series with the permanent magnet DC motors 1 through wires 8 to form a closed circuit. The range of the circuit resistance is from the sum of the inherent resistances of the two sets of permanent magnet DC motors 1 to the sum of the inherent resistances of the two sets of permanent magnet DC motors 1 and the maximum resistance of the sliding rheostat 7.

[0027] like Figure 4 As shown, a linear drive conversion system is provided between multiple sets of gearboxes. The linear drive conversion system includes a drive gear assembly and a rack 6. The drive gear assembly includes a drive gear 13 composed of a bevel gear 200 and a spur gear 300, and a transmission shaft 12 coaxial with the drive gear 13 and perpendicular to the reversing gear 5. The rack 6 meshes with the spur gear 300 of the drive gear 13 through a limiting device.

[0028] like Figure 4 As shown, the limiting device includes two shaft supports 10 spaced apart from each other, which are respectively connected to the transmission gearbox. A transmission shaft 12 and a rotating bearing 11 are arranged between the shaft supports 10. The rotating bearing 11 is in contact with the groove of the spur rack 6. In order to limit the spur rack 6 and the spur gear in the drive gear 13 to be on the same working plane, the groove of the spur rack 6 is in tangential contact with the outer circle of the rotating bearing 11 of the limiting device.

[0029] like Figure 6-7As shown, the large-pitch helical gear in the double-layer helical gear 4 meshes with the helical gear of the main shaft of the permanent magnet DC motor 1 in the same plane. The small-pitch helical gear in the double-layer helical gear 4 meshes with the helical gear 100 of the reversing gear 5 in the same plane. The bevel gear 200 in the reversing gear 5 meshes with the bevel gear 200 in the drive gear 13 in a vertical plane. The spur gear 300 of the drive gear 13 meshes with the spur rack 6. This structure can amplify the output speed by a factor of two based on the input speed, while also enabling the high-speed rotating components to generate inertial forces and obtain negative stiffness characteristics. The center axis of the main shaft of the permanent magnet DC motor 1, the center axis of the double-layer helical gear 4 in the gearbox, and the center axis of the reversing gear assembly are all in the same plane. Furthermore, the center axis of the main shaft of the permanent magnet DC motor 1 is collinear with the center axis of the reversing gear assembly, and the center axis of the reversing gear 5 is perpendicular to the center axis of the drive gear 13. The center axis of the spur rack 6 is perpendicular to the center line of the drive gear 13 and parallel to the center axis of the main shaft of the permanent magnet DC motor 1. The gears in the double-layer helical gear assembly, commutator gear assembly, and drive gear assembly are all configured with the same module. The small-pitch helical gear in the double-layer helical gear assembly has the same pitch circle diameter as the helical gear on the main shaft of the permanent magnet DC motor 1. The large-pitch helical gear in the double-layer helical gear assembly has the same pitch circle diameter as the helical gear in the commutator gear assembly.

[0030] In this embodiment, the high-speed and low-speed drive shafts 12 are respectively bonded and fixed to the inner ring of the rotating bearing 11 with chemical adhesives to limit the axial movement between the drive shaft 12 and the rotating bearing 11. In order to limit the relative movement of the internal components of the limiting device, the drive shaft 12 in the limiting device is respectively bonded and fixed to the shaft support 10 and the inside of the rotating bearing 11 with chemical adhesives.

[0031] To restrict the movement of the rotating bearing 11 in directions other than its rotational direction, the rotating bearings 11 of the double-layer helical gear assembly and the reversing gear assembly are embedded inside the plate of the housing 2. The gearbox has at least one pair of set bolts in the radial direction of each rotating bearing 11 to restrict the relative movement between the outer ring of the rotating bearing 11 and the housing 2. In this embodiment, the spacing between the two sets of housings 2 is adapted to the distance between the bevel gears of the drive gear 13. This embodiment is not limited to two sets; multiple sets of gearboxes are connected in parallel to achieve multiple damping, and the arrangement of the multiple sets of gearboxes follows a symmetrical principle.

[0032] In this embodiment, as Figure 1-3 As shown, right-angle fixed supports 9 are provided on both sides of the gearbox and are connected by bolts. One right-angle fixed support 9 is connected to the permanent magnet DC motor 1 by bolts, and the other right-angle fixed support 9 serves as a fixed end and is fixedly connected to the external component by bolts. A linear drive shaft 16 is provided at the bottom of the rack 6 and is fixed to the housing 14 by a linear bearing 15.

[0033] The adjustable negative stiffness electromagnetic damping device provided in this embodiment is applied in structural vibration control. It provides negative stiffness while simultaneously generating considerable damping for energy dissipation, achieving a dual-control strategy for structural displacement and absolute acceleration effects. The damping in the system can be further pre-adjusted using a sliding resistor. The experimental results of the negative stiffness electromagnetic damping device under hysteretic loading with different total resistance values ​​of the closed loop under a sinusoidal loading period of 10 seconds are as follows: Figure 8 As shown. The experimental results for hysteretic loading with different sinusoidal periods under the condition that the total resistance of the closed loop is constant at 10 ohms are as follows. Figure 9 As shown.

[0034] Example 2 In this embodiment, the adjustable negative stiffness electromagnetic damping device 17 is used in specific installation applications. The right-angle fixed support 9 can be connected to the outer shell, using the outer shell as the fixed end to connect it to other components. The rack 6 can be equipped with a linear drive shaft and linear bearings as the moving end to participate in the work. The arrangement is as follows: Figure 10 As shown. That is, a linear drive shaft 16 is provided at the bottom of the rack 6, and it is fixed to the housing 14 by a linear bearing 15. Figure 10 The combined device shown can also be used as a whole in the isolation layer of a seismic isolation structure.

[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. These embodiments not explicitly written should also be considered to be within the scope of this specification.

[0036] The present application has been described in a relatively specific and detailed manner above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.

Claims

1. A damping-adjustable negative stiffness electromagnetic damping device, characterized in that: It includes a permanent magnet DC motor (1), a linear drive conversion system, a sliding rheostat (7), and a speed gearbox; The gearbox includes a housing (2), a cover plate (3), and a double-layer helical gear assembly and a reversing gear assembly that mesh with each other inside. The double-layer helical gear assembly includes double-layer helical gears (4) of different sizes and a high-speed transmission shaft (12) that is coaxial with the double-layer helical gears (4) and connected to them by rotating bearings (11) at both ends. The reversing gear assembly includes a reversing gear (5) of a helical gear (100) and a bevel gear (200) with the same pitch circle and a low-speed transmission shaft (12) that is coaxial with the reversing gear (5). Two rotating bearings (11) that are spaced apart are provided at the end of the low-speed transmission shaft (12). A sliding rheostat (7) is provided between the two permanent magnet DC motors (1). The two ends of the sliding rheostat (7) are connected in series with the permanent magnet DC motor (1) through wires (8) to form a closed loop. The range of line resistance variation is from the sum of the inherent resistance of the two permanent magnet DC motors (1) to the sum of the inherent resistance of the two permanent magnet DC motors (1) and the maximum resistance of the sliding rheostat (7). A linear drive conversion system is provided between the multiple sets of the aforementioned gearboxes. The linear drive conversion system includes a drive gear assembly and a rack (6). The drive gear assembly includes a drive gear (13) composed of a bevel gear (200) and a spur gear (300) and a transmission shaft (12) coaxial with the drive gear (13) and perpendicular to the reversing gear (5). The rack (6) meshes with the spur gear (300) of the drive gear (13) through a limiting device. The limiting device includes two shaft supports (10) arranged at relative intervals, which are respectively connected to the gearbox. A transmission shaft (12) and a rotating bearing (11) are arranged between the shaft supports (10). The rotating bearing (11) is in contact with the groove of the spur rack (6). The helical gear with a large pitch circle in the double-layer helical gear (4) meshes with the helical gear of the main shaft of the permanent magnet DC motor (1) in the same plane. The helical gear with a small pitch circle in the double-layer helical gear (4) meshes with the helical gear (100) of the reversing gear (5) in the same plane. The bevel gear (200) in the reversing gear (5) meshes with the bevel gear (200) in the drive gear (13) in the vertical plane. The spur gear (300) of the drive gear (13) meshes with the spur rack (6). This structure can amplify the output speed by a factor of two based on the input speed, and at the same time make the high-speed rotating parts generate inertial force to obtain negative stiffness characteristics. The central axis of the main shaft of the permanent magnet DC motor (1), the central axis of the double-layer helical gear (4) in the gearbox, and the central axis of the reversing gear assembly are in the same plane. The central axis of the main shaft of the permanent magnet DC motor (1) is collinear with the central axis of the reversing gear assembly. The central axis of the reversing gear (5) is perpendicular to the central axis of the drive gear (13). The central axis of the spur rack (6) is perpendicular to the central axis of the drive gear (13) and parallel to the central axis of the main shaft of the permanent magnet DC motor (1). In order to limit the movement of the rotating bearing (11) in directions other than its rotation direction, the rotating bearing (11) of the double-layer helical gear assembly and the reversing gear assembly is embedded in the plate of the housing (2). The gearbox has at least one pair of set bolts in the radial direction of each rotating bearing (11) to limit the relative movement of the outer ring of the rotating bearing (11) and the housing (2).

2. The damper-adjustable negative stiffness electromagnetic damper device according to claim 1, wherein: The gears in the double-layer helical gear assembly, the reversing gear assembly, and the drive gear assembly are all set to the same module; the small pitch circle helical gear in the double-layer helical gear assembly has the same pitch circle diameter as the helical gear of the main shaft of the permanent magnet DC motor (1); the large pitch circle helical gear in the double-layer helical gear assembly has the same pitch circle diameter as the helical gear in the reversing gear (5) assembly.

3. The damper-adjustable negative stiffness electromagnetic damper device according to claim 1, wherein: The high-speed and low-speed drive shafts (12) are respectively bonded and fixed to the inner ring of the rotating bearing (11) by chemical adhesive to restrict the axial movement between the drive shaft (12) and the rotating bearing (11).

4. The damper-adjustable negative stiffness electromagnetic damper device of claim 1, wherein: The spacing between multiple gearboxes (2) is matched with the distance between the bevel gears of the drive gear (13); multiple gearboxes are connected in parallel to obtain multiple damping, and the arrangement of the multiple gearboxes follows the principle of symmetry.

5. The damping adjustable negative stiffness electromagnetic damping device according to claim 1, characterized in that: In order to limit the relative movement of the internal components of the limiting device, the transmission shaft (12) in the limiting device is bonded and fixed to the shaft support (10) and the rotating bearing (11) with chemical adhesive.

6. The damping adjustable negative stiffness electromagnetic damping device according to claim 1, characterized in that: In order to limit the spur rack (6) and the spur gear in the drive gear (13) to be on the same working plane, the groove of the spur rack (6) is in tangential contact with the outer circle of the rotating bearing (11) of the limiting device.

7. The damping adjustable negative stiffness electromagnetic damping device according to claim 1, characterized in that: The gearbox is provided with right-angle fixed supports (9) on both sides and connected by bolts. One right-angle fixed support (9) is connected to the permanent magnet DC motor (1) by bolts, and the other right-angle fixed support (9) is fixedly connected to the external component by bolts as a fixed end. The bottom of the rack (6) is provided with a linear drive shaft (16) and is fixed on the outer shell (14) by a linear bearing (15).

8. An application of an adjustable-damping negative stiffness electromagnetic damping device, which employs the adjustable-damping negative stiffness electromagnetic damping device according to any one of claims 1-7, characterized in that: This adjustable negative stiffness electromagnetic damping device is used as a whole in the isolation layer of the seismic isolation structure.

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