A torsional electromagnetic negative stiffness vibration isolation system

Abstract

This invention discloses a torsional electromagnetic negative stiffness vibration isolation system, relating to the field of torsional vibration control technology. It includes a torsional electromagnetic negative stiffness mechanism, a first positive stiffness torsional spring, and a second positive stiffness torsional spring. The torsional electromagnetic negative stiffness mechanism comprises a stator, a mover, and a coil. The stator is arranged around the mover, and the coil is wound around the mover. The outer surface of the mover has a mover tooth ring, and the inner surface of the stator has a stator tooth ring. The mover tooth ring includes multiple mover magnetic teeth evenly distributed circumferentially, and the stator tooth ring includes multiple stator magnetic teeth evenly distributed circumferentially. Stator slots are formed between adjacent stator magnetic teeth, and the mover magnetic teeth correspond one-to-one with the stator slots. One end of the mover is connected to a first support base via a first central shaft and a first positive stiffness torsional spring, and the other end is connected to a second support base via a second central shaft and a second positive stiffness torsional spring. This invention effectively isolates low-frequency torsional vibration, has a compact structure, adjustable stiffness, and no residual negative stiffness.

Description

Technical Field

[0001] This invention relates to the field of torsional vibration control technology, and in particular to a torsional electromagnetic negative stiffness vibration isolation system. Background Technology

[0002] Vibration and noise control is a key technical issue in fields such as precision machinery, power transmission, and aerospace. In particular, low-frequency torsional vibration can easily cause problems such as system resonance, structural fatigue, and decreased transmission accuracy. Traditional vibration isolation and reduction methods are difficult to balance high load-bearing capacity and low-frequency vibration isolation effect.

[0003] Traditional torsional vibration damping devices mostly use linear positive stiffness structures such as rubber elastic elements and metal torsion springs, which have high natural frequencies and limited effect on suppressing low-frequency torsional vibrations. If low-frequency vibration isolation is achieved by reducing stiffness, it will lead to excessive static deformation and insufficient load-bearing capacity, resulting in an inherent contradiction between low stiffness and high load-bearing capacity.

[0004] To overcome these bottlenecks, researchers proposed a quasi-zero stiffness vibration isolation principle. By connecting a negative stiffness mechanism in parallel with a positive stiffness element, the total dynamic stiffness approaches zero near the equilibrium position. This significantly reduces the system's natural frequency while maintaining high static stiffness, achieving excellent low-frequency vibration isolation performance. Existing methods for achieving negative stiffness are mostly mechanical structures, such as buckling beams and cam-roller mechanisms. While these can provide negative stiffness, they suffer from drawbacks such as contact friction, severe wear, and non-adjustable stiffness, making it difficult to meet the long-term reliability and control precision requirements of high-end equipment.

[0005] Electromagnetic negative stiffness technology, with its advantages of being non-contact, wear-free, fast-response, and adjustable stiffness, is gradually becoming an important direction for achieving negative stiffness. However, existing electromagnetic negative stiffness structures are mostly designed for translational vibration isolation, lacking mechanism optimization for torsional vibration isolation. Summary of the Invention

[0006] The purpose of this invention is to provide a torsional electromagnetic negative stiffness vibration isolation system to solve the problems existing in the prior art. It can effectively isolate low-frequency torsional vibration, has a compact structure, adjustable stiffness and no residual negative stiffness, and ensures the safety and stability of the system.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a torsional electromagnetic negative stiffness vibration isolation system, comprising a torsional electromagnetic negative stiffness mechanism, a first positive stiffness torsional spring, and a second positive stiffness torsional spring; The torsional electromagnetic negative stiffness mechanism includes a stator, a mover, and a coil. The stator is arranged around the outside of the mover, and the coil is wound around the mover. The outer surface of the mover is provided with a mover tooth ring, and the inner surface of the stator is provided with a stator tooth ring corresponding to the mover tooth ring. An air gap is left between the stator tooth ring and the mover tooth ring. The mover tooth ring includes a plurality of mover magnetic teeth evenly distributed circumferentially, and the stator tooth ring includes a plurality of stator magnetic teeth evenly distributed circumferentially and equal in number to the mover magnetic teeth. A stator tooth slot is formed between two adjacent stator magnetic teeth, and the mover magnetic teeth and the stator tooth slots are arranged in a one-to-one correspondence. One end of the mover is fixedly connected to a first central shaft, and the other end is fixedly connected to a second central shaft. One end of the stator is fixedly connected to a first support base, and the other end is fixedly connected to a second support base. The first central shaft is rotatably connected within the first support base, and the second central shaft is rotatably connected within the second support base. The middle part of the first positive stiffness torsion spring is connected to the first central shaft, and the two are fixed relative to each other in the circumferential direction. The outer ring of the first positive stiffness torsion spring is fixed to the first support base. The middle part of the second positive stiffness torsion spring is connected to the second central shaft, and the two are fixed relative to each other in the circumferential direction. The outer ring of the second positive stiffness torsion spring is fixed to the second support base.

[0008] In some embodiments, the stator includes a first stator magnetic pole, a second stator magnetic pole, and a magnetic pole support member. The first stator magnetic pole and the second stator magnetic pole are respectively fixed to both ends of the magnetic pole support member. Each of the inner surfaces of the first stator magnetic pole and the second stator magnetic pole is provided with a stator gear ring. The mover includes a first mover portion and a second mover portion fixedly connected. Each of the outer surfaces of the first mover portion and the second mover portion is provided with a mover gear ring. The stator gear ring of the first stator magnetic pole is correspondingly arranged with the mover gear ring of the first mover portion, and the stator gear ring of the second stator magnetic pole is correspondingly arranged with the mover gear ring of the second mover portion.

[0009] In some embodiments, the coil is wound around the first portion of the mover and located between the mover gear ring of the first portion of the mover and the mover gear ring of the second portion of the mover.

[0010] In some embodiments, the first central shaft is rotatably connected to the first support base via a first bearing, and the second central shaft is rotatably connected to the second support base via a second bearing.

[0011] In some embodiments, both the first positive stiffness torsion spring and the second positive stiffness torsion spring have a square hole in the middle, and both the first central shaft and the second central shaft have a square shaft segment that mates with the square hole; a positioning block is fixedly provided on the outer ring of the first positive stiffness torsion spring, and a positioning groove that mates with the positioning block is provided on the first support base.

[0012] In some embodiments, the moving magnetic tooth and the stator magnetic tooth have the same tooth width, tooth height and tooth thickness.

[0013] In some embodiments, the first part of the moving part is fixed with a first square connecting shaft at one end near the first central shaft. The end of the first central shaft is provided with a first square connecting hole that is inserted and connected to the first square connecting shaft. The side wall of the first central shaft is provided with a first set screw hole that communicates with the first square connecting hole. A first set screw is threaded into the first set screw hole.

[0014] In some embodiments, a second square connecting shaft is fixed to one end of the first part of the mover near the second part of the mover, and a second square connecting hole is provided at the end of the second part of the mover to be inserted and connected to the second square connecting shaft. A second set screw hole communicating with the second square connecting hole is provided on the side wall of the second part of the mover, and a second set screw is threaded into the second set screw hole.

[0015] In some embodiments, a third-shaped connecting shaft is fixed to one end of the second part of the mover near the second central shaft. The end of the second central shaft is provided with a third-shaped connecting hole that is inserted and connected to the third-shaped connecting shaft. A third set screw hole communicating with the third-shaped connecting hole is provided on the side wall of the second central shaft. A third set screw is internally threaded into the third set screw hole.

[0016] In some embodiments, the first central shaft includes a first threaded segment adjacent to its square shaft segment, on which a first limiting nut is threadedly connected; the second central shaft includes a second threaded segment adjacent to its square shaft segment, on which a second limiting nut is threadedly connected.

[0017] The present invention achieves the following technical effects compared to the prior art: The torsional electromagnetic negative stiffness vibration isolation system provided by this invention uses a torsional electromagnetic negative stiffness mechanism connected in parallel with a first positive stiffness torsional spring and a second positive stiffness torsional spring. The first and second positive stiffness torsional springs provide high static stiffness, while the torsional electromagnetic negative stiffness mechanism provides negative stiffness. The magnitude and sign of the electromagnetic stiffness can be directly adjusted online by changing the magnitude and direction of the applied excitation current, thereby adjusting the total stiffness to achieve high static and low dynamic stiffness for low-frequency torsional vibration isolation. The torsional electromagnetic negative stiffness mechanism of this invention adopts a distributed structure of inner and outer movers and stators, and positive stiffness torsional springs are connected in parallel at both ends of the mechanism, integrating the positive and negative stiffness mechanisms. This results in a compact structure and small size. Furthermore, this invention uses a pure electromagnet-type torsional electromagnetic negative stiffness mechanism, which eliminates residual negative stiffness after the excitation current is cut off, preventing residual negative stiffness from affecting control accuracy and stability, and ensuring safe and stable system operation. 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 embodiments 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 torsional electromagnetic negative stiffness vibration isolation system in an embodiment of the present invention; Figure 2 This is a three-dimensional cross-sectional view of the torsional electromagnetic negative stiffness vibration isolation system in an embodiment of the present invention. Figure 3 This is a cross-sectional view of the connection structure between the moving part and the first central shaft, the second central shaft, the first positive stiffness torsion spring, and the second positive stiffness torsion spring in an embodiment of the present invention. Figure 4 This is a schematic diagram of the interlaced magnetic tooth structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the first positive stiffness torsion spring in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the second positive stiffness torsion spring in an embodiment of the present invention.

[0020] In the diagram: 1- Torsional electromagnetic negative stiffness mechanism, 2- First positive stiffness torsional spring, 201- Positioning block, 3- Second positive stiffness torsional spring, 4- Stator, 401- First stator magnetic pole, 402- Second stator magnetic pole, 403- Magnetic pole support, 5- Mover, 501- First part of mover, 5011- First square connecting shaft, 5012- Second square connecting shaft, 502- Second part of mover, 5021- Second square connecting hole, 5022- Third square connecting shaft, 6- Coil, 7- Mover Magnetic teeth, 8-Stator magnetic teeth, 9-Stator tooth groove, 10-First central shaft, 101-First square shaft segment, 102-First square connecting hole, 103-First threaded segment, 11-Second central shaft, 111-Second square shaft segment, 112-Third square connecting hole, 113-Second threaded segment, 12-First support seat, 121-Positioning groove, 13-Second support seat, 14-First bearing, 15-Second bearing, 16-Square hole, 17-Air gap, 18-Shaft end cap, 181-Connecting shaft. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The purpose of this invention is to provide a torsional electromagnetic negative stiffness vibration isolation system to solve the problems existing in the prior art. It can effectively isolate low-frequency torsional vibration, has a compact structure, adjustable stiffness and no residual negative stiffness, and ensures the safety and stability of the system.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1-6 As shown, this embodiment provides a torsional electromagnetic negative stiffness vibration isolation system, including a torsional electromagnetic negative stiffness mechanism 1, a first positive stiffness torsional spring 2, and a second positive stiffness torsional spring 3. The torsional electromagnetic negative stiffness mechanism 1 includes a stator 4, a mover 5, and a coil 6. The stator 4 is arranged around the outside of the mover 5, and the coil 6 is wound around the mover 5. The outer surface of the mover 5 is provided with a mover tooth ring, and the inner surface of the stator 4 is provided with a stator tooth ring corresponding to the mover tooth ring. An air gap 17 is left between the stator tooth ring and the mover tooth ring. The mover tooth ring includes a plurality of mover magnetic teeth 7 evenly distributed in the circumferential direction, and the stator tooth ring includes a plurality of stator magnetic teeth 8 evenly distributed in the circumferential direction and equal in number to the mover magnetic teeth 7. A stator tooth groove 9 is formed between two adjacent stator magnetic teeth 8, and the mover magnetic teeth 7 and the stator tooth groove 9 are arranged in a one-to-one correspondence. In this embodiment, the tooth width, tooth height, and tooth thickness of the mover magnetic teeth 7 and the stator magnetic teeth 8 are all equal. One end of the mover 5 is fixedly connected to a first central shaft 10, and the other end is fixedly connected to a second central shaft 11. One end of the stator 4 is fixedly connected to a first support base 12, and the other end is fixedly connected to a second support base 13. The first central shaft 10 is rotatably connected inside the first support base 12, and the second central shaft 11 is rotatably connected inside the second support base 13. The middle part of the first positive stiffness torsion spring 2 is connected to the first central shaft 10, and the two are fixed relative to each other in the circumferential direction. The outer ring of the first positive stiffness torsion spring 2 is fixed to the first support base 12 by bolts. The middle part of the second positive stiffness torsion spring 3 is connected to the second central shaft 11, and the two are fixed relative to each other in the circumferential direction. The outer ring of the second positive stiffness torsion spring 3 is fixed to the second support base 13 by bolts.

[0025] In the static equilibrium position, the moving magnetic teeth 7 and the stator tooth slots 9 are arranged in a one-to-one correspondence (i.e., precisely aligned in the inner and outer directions, i.e., staggered magnetic tooth structure). At this time, the electromagnetic torque generated between each moving magnetic tooth 7 and the surrounding stator magnetic teeth 8 is symmetrical, so the electromagnetic resultant torque is zero, and the moving 5 remains stable and stationary in this position. When the external vibration excitation causes a relative angular displacement between the moving 5 and the stator 4, an electromagnetic torque with negative stiffness characteristics that promotes this angular displacement will be generated between the moving magnetic teeth 7 and the stator magnetic teeth 8.

[0026] The second support 13, away from the stator 4, is fixedly connected to a shaft end cap 18 by bolts. A connecting shaft 181 is fixedly provided in the middle of the end of the shaft end cap 18 away from the second support 13. In use, the load is connected to the connecting shaft 181. Torsional vibration is transmitted to the vibration isolation system of this embodiment through the first central shaft 10. After vibration isolation by the vibration isolation system, it is transmitted to the load. The torsional electromagnetic negative stiffness mechanism 1 is arranged in parallel with the first positive stiffness torsional spring 2 and the second positive stiffness torsional spring 3. The first positive stiffness torsional spring 2 and the second positive stiffness torsional spring 3 provide high static stiffness, and the torsional electromagnetic negative stiffness mechanism 1 provides negative stiffness. The magnitude and direction of the applied excitation current are changed to directly adjust the magnitude and sign of the electromagnetic stiffness online, thereby adjusting the total stiffness. This makes the vibration isolation system exhibit a composite characteristic of high static and low dynamic stiffness, thereby achieving low-frequency torsional vibration isolation.

[0027] In this embodiment, the torsional electromagnetic negative stiffness mechanism adopts a distributed structure of inner and outer movers and stators, and positive stiffness torsional springs (first positive stiffness torsional spring 2 and second positive stiffness torsional spring 3) are connected in parallel at both ends of the torsional electromagnetic negative stiffness mechanism 1, integrating the positive stiffness and negative stiffness mechanisms, resulting in a compact structure and small size. This embodiment uses a pure electromagnet-type torsional electromagnetic negative stiffness mechanism 1, which will not have residual negative stiffness after the excitation current is cut off, avoiding the impact of residual negative stiffness on control accuracy and stability, and ensuring that the system can operate safely and stably.

[0028] The stator 4 includes a first stator magnetic pole 401, a second stator magnetic pole 402, and a magnetic pole support 403. The first stator magnetic pole 401 and the second stator magnetic pole 402 are respectively fixed to both ends of the magnetic pole support 403 by bolts. A stator gear ring is provided on the inner surface of both the first stator magnetic pole 401 and the second stator magnetic pole 402. The mover 5 includes a first mover part 501 and a second mover part 502 fixedly connected. A mover gear ring is provided on the outer surface of both the first mover part 501 and the second mover part 502. The stator gear ring of the first stator magnetic pole 401 corresponds to the mover gear ring of the first mover part 501, and the stator gear ring of the second stator magnetic pole 402 corresponds to the mover gear ring of the second mover part 502. A coil 6 is wound on the first mover part 501 and located between the mover gear rings of the first mover part 501 and the second mover part 502.

[0029] The first central shaft 10 is rotatably connected to the first support base 12 via the first bearing 14, and the second central shaft 11 is rotatably connected to the second support base 13 via the second bearing 15. The first central shaft 10 is radially supported by the first bearing 14, and the second central shaft 11 is radially supported by the second bearing 15, thus ensuring the stability of the structure.

[0030] Both the first positive stiffness torsion spring 2 and the second positive stiffness torsion spring 3 have square holes 16 in their middle portions. The first central shaft 10 and the second central shaft 11 each have square shaft segments that mate with the square holes 16, namely, a first square shaft segment 101 and a second square shaft segment 111, respectively. The first square shaft segment 101 is for the first central shaft 10, and the second square shaft segment 111 is for the second central shaft 11. A first square connecting shaft 5011 is fixed to one end of the first moving part 501 near the first central shaft 10. The end of the first central shaft 10 has a first square connecting hole 102 that is inserted into the first square connecting shaft 5011. A first set screw hole communicating with the first square connecting hole 102 is provided on the side wall of the first central shaft 10, and a first set screw is threaded into the first set screw hole. The first moving part... A second square connecting shaft 5012 is fixed to one end of the second part 502 of the mover 501. The end of the second part 502 of the mover has a second square connecting hole 5021 that is inserted into the second square connecting shaft 5012. A second set screw hole communicating with the second square connecting hole 5021 is provided on the side wall of the second part 502 of the mover, and a second set screw is threaded into the second set screw hole. A third square connecting shaft 5022 is fixed to one end of the second part 502 of the mover near the second central shaft 11. The end of the second central shaft 11 has a third square connecting hole 112 that is inserted into the third square connecting shaft 5022. A third set screw hole communicating with the third square connecting hole 112 is provided on the side wall of the second central shaft 11, and a third set screw is threaded into the third set screw hole. Torque is transmitted through the mating structure of the square hole and the square shaft, and the shaft and hole are axially locked by the set screw. The structure is simple and easy to install and disassemble.

[0031] A positioning block 201 is fixedly provided on the outer ring of the first positive stiffness torsion spring 2. A positioning groove 121 that cooperates with the positioning block 201 is provided on the first support base 12. The positioning block 201 and the positioning groove 121 can be used to circumferentially position the first positive stiffness torsion spring 2, ensuring that after the first central shaft 10 and the moving part 5 connected thereto are installed and positioned through the square hole 16 in the middle of the first positive stiffness torsion spring 2, the moving part magnetic teeth 7 and the stator tooth groove 9 are aligned inside and outside.

[0032] The first central shaft 10 includes a first threaded section 103 adjacent to its square shaft segment (first square shaft segment 101), and a first limiting nut is threaded onto the first threaded section 103. The second central shaft 11 includes a second threaded section 113 adjacent to its square shaft segment (second square shaft segment 111), and a second limiting nut is threaded onto the second threaded section 113. The first limiting nut can axially limit the first positive stiffness torsion spring 2, and the second limiting nut can axially limit the second positive stiffness torsion spring 3, thereby improving the stability of the structure.

[0033] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A torsional electromagnetic negative stiffness vibration isolation system, characterized in that: It includes a torsional electromagnetic negative stiffness mechanism, a first positive stiffness torsional spring, and a second positive stiffness torsional spring; The torsional electromagnetic negative stiffness mechanism includes a stator, a mover, and a coil. The stator is arranged around the outside of the mover, and the coil is wound around the mover. The outer surface of the mover is provided with a mover tooth ring, and the inner surface of the stator is provided with a stator tooth ring corresponding to the mover tooth ring. An air gap is left between the stator tooth ring and the mover tooth ring. The mover tooth ring includes a plurality of mover magnetic teeth evenly distributed circumferentially, and the stator tooth ring includes a plurality of stator magnetic teeth evenly distributed circumferentially and equal in number to the mover magnetic teeth. A stator tooth slot is formed between two adjacent stator magnetic teeth, and the mover magnetic teeth and the stator tooth slots are arranged in a one-to-one correspondence. One end of the mover is fixedly connected to a first central shaft, and the other end is fixedly connected to a second central shaft. One end of the stator is fixedly connected to a first support base, and the other end is fixedly connected to a second support base. The first central shaft is rotatably connected within the first support base, and the second central shaft is rotatably connected within the second support base. The middle part of the first positive stiffness torsion spring is connected to the first central shaft, and the two are fixed relative to each other in the circumferential direction. The outer ring of the first positive stiffness torsion spring is fixed to the first support base. The middle part of the second positive stiffness torsion spring is connected to the second central shaft, and the two are fixed relative to each other in the circumferential direction. The outer ring of the second positive stiffness torsion spring is fixed to the second support base.

2. The torsional electromagnetic negative stiffness vibration isolation system according to claim 1, characterized in that: The stator includes a first stator magnetic pole, a second stator magnetic pole, and a magnetic pole support member. The first stator magnetic pole and the second stator magnetic pole are respectively fixed to both ends of the magnetic pole support member. Each of the inner surfaces of the first stator magnetic pole and the second stator magnetic pole is provided with a stator gear ring. The mover includes a first mover part and a second mover part fixedly connected. Each of the outer surfaces of the first mover part and the second mover part is provided with a mover gear ring. The stator gear ring of the first stator magnetic pole is correspondingly arranged with the mover gear ring of the first mover part, and the stator gear ring of the second stator magnetic pole is correspondingly arranged with the mover gear ring of the second mover part.

3. The torsional electromagnetic negative stiffness vibration isolation system according to claim 2, characterized in that: The coil is wound around the first part of the mover and is located between the mover gear ring of the first part of the mover and the mover gear ring of the second part of the mover.

4. The torsional electromagnetic negative stiffness vibration isolation system according to claim 1, characterized in that: The first central shaft is rotatably connected to the first support base via a first bearing, and the second central shaft is rotatably connected to the second support base via a second bearing.

5. The torsional electromagnetic negative stiffness vibration isolation system according to claim 1, characterized in that: Both the first and second positive stiffness torsion springs have square holes in their middle portions, and both the first and second central shafts have square shaft segments that mate with the square holes. The outer ring of the first positive stiffness torsion spring is fixedly provided with a positioning block, and the first support base is provided with a positioning groove that mates with the positioning block.

6. The torsional electromagnetic negative stiffness vibration isolation system according to claim 1, characterized in that: The moving magnetic tooth and the stator magnetic tooth have the same tooth width, tooth height and tooth thickness.

7. The torsional electromagnetic negative stiffness vibration isolation system according to claim 2, characterized in that: The first part of the moving part is fixed with a first square connecting shaft at one end near the first central shaft. The end of the first central shaft is provided with a first square connecting hole that is inserted and connected to the first square connecting shaft. The side wall of the first central shaft is provided with a first set screw hole that communicates with the first square connecting hole. A first set screw is threaded into the first set screw hole.

8. The torsional electromagnetic negative stiffness vibration isolation system according to claim 7, characterized in that: The first part of the moving part is fixed with a second square connecting shaft at one end near the second part of the moving part. The end of the second part of the moving part is provided with a second square connecting hole that is inserted and connected to the second square connecting shaft. The side wall of the second part of the moving part is provided with a second set screw hole that communicates with the second square connecting hole. A second set screw is threaded into the second set screw hole.

9. The torsional electromagnetic negative stiffness vibration isolation system according to claim 8, characterized in that: The second part of the moving part is fixed with a third-shaped connecting shaft at one end near the second central shaft. The end of the second central shaft is provided with a third-shaped connecting hole that is inserted and connected to the third-shaped connecting shaft. The side wall of the second central shaft is provided with a third set screw hole that communicates with the third-shaped connecting hole. A third set screw is internally threaded into the third set screw hole.

10. The torsional electromagnetic negative stiffness vibration isolation system according to claim 5, characterized in that: The first central shaft includes a first threaded segment adjacent to its square shaft segment, and a first limiting nut is threadedly connected to the first threaded segment. The second central shaft includes a second threaded segment adjacent to its square shaft segment, and a second limiting nut is threadedly connected to the second threaded segment.

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