Multi-stable-state composite vibration isolator

Abstract

The invention discloses a multistable composite vibration isolator, and relates to the technical field of vibration control, the multistable composite vibration isolator comprises a main vibration isolation system and a double-magnetic screw unit, the main vibration isolation system comprises a base, a supporting platform, a load platform and an elastic element, and the double-magnetic screw unit comprises a magnetic screw, an upper magnetic nut, a lower magnetic nut, a counterweight device, a rotating platform and a locking device. The magnetic screw is fixedly connected with the load platform and penetrates through the supporting platform, the upper magnetic nut and the lower magnetic nut, the upper magnetic nut is arranged between the supporting platform and the load platform, the counterweight device is fixed outside the upper magnetic nut, the upper magnetic nut rotates circumferentially and is fixed axially, and the lower magnetic nut is arranged between the base and the supporting platform. The lower magnetic nut is fixed to the rotating platform, the rotating platform rotates on the base, the locking device limits the rotating platform, and the lower magnetic nut and the magnetic screw are located at an unstable balance point of axial magnetic force. According to the invention, the parasitic stiffness of the magnetic inerter can be effectively compensated, the excellent frequency-variable damping characteristic is kept, and the self-adaption to different loads and balance positions is realized.

Description

Technical Field

[0001] This invention relates to the field of vibration control technology, and in particular to a multi-stable composite vibration isolator. Background Technology

[0002] Traditional passive vibration isolation systems (such as spring-damper systems) inherently suffer from a waterbed effect; that is, while increasing damping can suppress low-frequency resonance, it significantly deteriorates high-frequency vibration isolation performance, and vice versa. To overcome this limitation, an inerter is introduced. An inerter generates a force proportional to the relative acceleration between its two ends, achieving a mass amplification effect. However, traditional mechanical inerters can worsen the system's high-frequency response.

[0003] In recent years, magnetic screws (MLS) have been used as non-contact magnetic inertial containers. They achieve the conversion of linear motion to rotational motion through magnetic field coupling, and a flywheel is added to provide inertia. These magnetic inertial containers exhibit frequency-varying characteristics: strong coupling at low frequencies and natural decoupling at high frequencies, thus maintaining excellent high-frequency vibration isolation performance while suppressing resonance. However, the inherent axial magnetic coupling force of the magnetic inertial container inevitably introduces nonlinear parasitic stiffness. This positive stiffness leads to stiffness hardening of the vibration isolation system, causing the natural frequency to shift to higher frequencies, i.e., the resonance peak shifts to the right, thereby narrowing the effective vibration isolation frequency band and limiting its application in ultra-low frequency vibration isolation.

[0004] To eliminate parasitic positive stiffness, the quasi-zero stiffness (QZS) design concept has been widely studied, the core of which is to connect positive stiffness elements and negative stiffness elements in parallel. However, existing quasi-zero stiffness (QZS) vibration isolators are usually very sensitive to load changes. Once the load mass changes and the system deviates from its equilibrium position, the vibration isolation performance drops sharply, limiting its use. Therefore, there is an urgent need for a multi-stable composite vibration isolator to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-stable composite vibration isolator to solve the problems existing in the prior art, effectively compensate for the parasitic stiffness of the magnetic inertial container, retain excellent frequency-varying damping characteristics, and achieve self-adaptation to different loads and equilibrium positions.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a multi-stable composite vibration isolator, comprising a main vibration isolation system and a dual magnetic screw unit, wherein; The main vibration isolation system includes a base, a support platform, a load platform, and an elastic element. The support platform is fixedly installed above the base, the load platform is located above the support platform, and the two ends of the elastic element are fixedly connected to the load platform and the support platform, respectively. The dual magnetic screw unit includes a magnetic screw, an upper magnetic nut, a lower magnetic nut, a counterweight device, and a rotating platform. The top of the magnetic screw is fixedly located at the center of the load platform, and the magnetic screw passes through the support platform, the upper magnetic nut, and the lower magnetic nut. The upper magnetic nut is sleeved on the magnetic screw and located between the support platform and the load platform. The counterweight device is fixedly located on the outer periphery of the upper magnetic nut. The upper magnetic nut and the support platform form a circumferentially rotating and axially fixed connection. The lower magnetic nut is sleeved on the magnetic screw and located between the base and the support platform. The lower magnetic nut is fixedly located on the rotating platform, which is rotatably mounted on the base. The rotating platform itself has a locking device. The lower magnetic nut and the magnetic screw are at an unstable equilibrium point of axial magnetic force.

[0007] In some embodiments, a guide shaft is also included, the bottom end of which is fixedly disposed on the base, and the guide shaft passes upward through the support platform and the load platform in sequence. The support platform and the guide shaft are fixed in relative position, and the elastic element is sleeved on the guide shaft.

[0008] In some embodiments, a first fixed seat, a second fixed seat, and a third fixed seat are also included. The top of the guide shaft extends through the load platform. The first fixed seat is fixedly disposed on the support platform and fixedly connected to the bottom of the elastic element. The second fixed seat is fixedly disposed on the load platform and fixedly connected to the middle of the elastic element. The third fixed seat is fixedly disposed on the top of the guide shaft and fixedly connected to the top of the elastic element. Both the first fixed seat and the second fixed seat are slidably sleeved on the guide shaft.

[0009] In some embodiments, a first support column is also included, the two ends of which are fixedly connected to the top surface of the base and the bottom surface of the support platform, respectively.

[0010] In some embodiments, a second support column and an auxiliary bearing platform are also included. The two ends of the second support column are fixedly connected to the top surface of the support platform and the bottom surface of the auxiliary bearing platform, respectively. The auxiliary bearing platform is located between the load platform and the support platform. The bottom end of the upper magnetic nut is rotatably connected to the support platform through a first bearing, and the top end is rotatably connected to the bearing auxiliary platform through a second bearing.

[0011] In some embodiments, the outer wall of the magnetic screw is spirally arrayed with multiple first magnetic tiles, and the outer wall of the upper magnetic nut is spirally arrayed with multiple second magnetic tiles. The pitch and direction of the second magnetic tiles are the same as those of the first magnetic tiles. Both the first and second magnetic tiles are radially magnetized, and the magnetization directions are opposite. The lower magnetic nut has the same structure as the upper magnetic nut.

[0012] In some embodiments, the counterweight device includes a flywheel and a counterweight pin, the counterweight pin being detachably disposed on the outer periphery of the flywheel, and the flywheel being fixedly sleeved on the outer periphery of the upper magnetic nut.

[0013] In some embodiments, the first support column, the second support column, the guide shaft, and the elastic element are all uniformly arranged in multiples around the magnetic screw.

[0014] In some embodiments, the elastic element is a vibration-damping spring.

[0015] In some embodiments, the rotating platform is a hollow rotary slide with a fine-tuning knob.

[0016] The present invention achieves the following technical effects compared to the prior art: The multi-stable composite vibration isolator provided by this invention forms a non-contact magnetic inertial capacitance with its upper magnetic nut and counterweight device. Utilizing the inherent frequency-varying characteristics of magnetic field coupling, it achieves differentiated working effects of strong low-frequency coupling and natural high-frequency decoupling. During low-frequency resonance, the vertical vibration of the load platform drives the magnetic screw to move synchronously. Through magnetic coupling, the upper magnetic nut and counterweight device rotate at high speed, generating a large inertial damping proportional to the relative acceleration at both ends. This effectively suppresses low-frequency resonance peaks and solves the problem of low-frequency resonance amplification in traditional vibration isolators. During high-frequency vibration isolation, the magnetic coupling response is sluggish under high-frequency vibration, naturally achieving dynamic decoupling. The damping effect of the magnetic inertial capacitance automatically disappears, avoiding the defect of traditional dampers where increased damping worsens high-frequency vibration isolation performance, thus achieving rapid attenuation of high-frequency vibrations.

[0017] By utilizing the coaxial parallel design of dual magnetic screws, the inherent defects of magnetic inertial capacitance are overcome, achieving ultra-wideband vibration isolation. When the upper magnetic nut operates as magnetic inertial capacitance, it inevitably introduces nonlinear parasitic positive stiffness, leading to system stiffness hardening, a rightward shift of the resonance peak, and a narrowing of the effective isolation frequency band. Meanwhile, the lower magnetic nut is locked at an unstable equilibrium point of magnetic coupling, generating negative stiffness with the same amplitude but opposite direction to the parasitic positive stiffness based on the axial multistable magnetic coupling characteristics. The upper and lower magnetic nuts share the same magnetic screw, naturally forming a parallel relationship. Their relative displacements are completely synchronized, and the total system stiffness is the algebraic sum of the positive and negative stiffnesses, macroscopically achieving quasi-zero stiffness (QZS) characteristics. This eliminates the negative impact of parasitic stiffness, prevents the resonance peak from shifting to higher frequencies, and broadens the effective operating frequency band of the vibration isolation system, especially improving the vibration isolation capability in the ultra-low frequency band.

[0018] Leveraging the multi-steady-state characteristics of the lower magnetic nut, coupled with a rotatable and lockable rotating platform, adaptive adaptation to any static load is achieved. When changing the load or adjusting the operating conditions, simply unlock the locking device, and the lower magnetic nut will rotate freely with the rotating platform. Under the action of magnetic coupling force, it will automatically find a stable equilibrium point under the new load. Then, it will be finely adjusted to rotate to an unstable equilibrium point and locked, thus achieving precise stiffness compensation at the new equilibrium position. This maintains the optimal near-zero stiffness vibration isolation effect without requiring structural modifications. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a schematic diagram of the structure of a multi-stable composite vibration isolator in some embodiments of the present invention; Figure 2 This is a schematic diagram of the counterweight device in some embodiments of the present invention; Figure 3 This is a schematic diagram of the structure of the magnetic screw in some embodiments of the present invention; Figure 4 This is a schematic diagram of the structure of the upper magnetic nut in some embodiments of the present invention; Figure 5 This is a schematic diagram of the installation of the lower magnetic nut in some embodiments of the present invention.

[0021] In the diagram: 1-base; 2-support; 3-guide shaft; 4-support platform; 5-load platform; 6-third fixed seat; 7-elastic element; 8-magnetic screw; 9-auxiliary bearing platform; 10-upper magnetic nut; 11-flywheel; 12-second support column; 13-lower magnetic nut; 14-rotating platform; 15-first support column; 16-first fixed seat; 17-second fixed seat; 18-counterweight pin; 19-first magnetic tile; 20-second magnetic tile. Detailed Implementation

[0022] 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.

[0023] The purpose of this invention is to provide a multi-stable composite vibration isolator to solve the problems existing in the prior art. It can effectively compensate for the parasitic stiffness of the magnetic inertial container, while retaining excellent frequency-varying damping characteristics and achieving self-adaptation to different loads and equilibrium positions.

[0024] 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.

[0025] like Figures 1-5 As shown, this invention provides a multi-stable composite vibration isolator, including a main vibration isolation system and a dual magnetic screw unit. The main vibration isolation system includes a base 1, a support platform 4, a load platform 5, and an elastic element 7. The support platform 4 is fixedly disposed above the base 1, and the load platform 5 is located above the support platform 4. Both ends of the elastic element 7 are fixedly connected to the load platform 5 and the support platform 4, respectively. The dual magnetic screw unit includes a magnetic screw 8, an upper magnetic nut 10, a lower magnetic nut 13, a counterweight device, and a rotating platform 14. The top of the magnetic screw 8 is fixedly disposed at the center of the load platform 5, and the magnetic screw 8 passes through the center of the support platform 4, the upper magnetic nut 10, and the lower magnetic nut 13. The bottom of the magnetic screw 8 is above the base 1. Between the lower magnetic nut 13 and the base 1, during vibration, the magnetic screw 8 has space and will not penetrate the base 1 and touch the ground. The upper magnetic nut 10 is sleeved on the magnetic screw 8 and located between the support platform 4 and the load platform 5. The counterweight device is fixedly set on the outer periphery of the upper magnetic nut 10. The upper magnetic nut 10 and the support platform 4 form a circumferential rotational and axially fixed connection through the bearing. The lower magnetic nut 13 is sleeved on the magnetic screw 8 and located between the base 1 and the support platform 4. The lower magnetic nut 13 is fixedly set on the rotating platform 14. The rotating platform 14 is rotatably set on the base 1. The rotating platform 14 has its own locking device, which can lock relative to the base 1 and prevent rotation. The lower magnetic nut 13 and the magnetic screw 8 are at an unstable equilibrium point of axial magnetic force.

[0026] The upper magnetic nut 10 and the counterweight device form a non-contact magnetic inertial capacitance. Relying on the natural frequency-varying characteristics of magnetic field coupling, it achieves differentiated working effects of strong coupling at low frequencies and natural decoupling at high frequencies. During low-frequency resonance, the vertical vibration of the load platform 5 drives the magnetic screw 8 to move synchronously. Through magnetic coupling, the upper magnetic nut 10 and the counterweight device are driven to rotate at high speed, generating a large inertial damping proportional to the relative acceleration at both ends. This effectively suppresses the low-frequency resonance peak and solves the problem of low-frequency resonance amplification in traditional vibration isolators. During high-frequency vibration isolation, the magnetic coupling response is sluggish under high-frequency vibration, naturally achieving dynamic decoupling. The damping effect of the magnetic inertial capacitance disappears automatically, avoiding the defect of traditional dampers where increasing damping will worsen the high-frequency vibration isolation performance, and achieving rapid attenuation of high-frequency vibration.

[0027] By utilizing the coaxial parallel design of dual magnetic screws, the inherent defects of magnetic inertial capacitance are overcome, achieving ultra-wideband vibration isolation. When the upper magnetic nut 10 operates as a magnetic inertial capacitance, it inevitably introduces nonlinear parasitic positive stiffness, leading to system stiffness hardening, a rightward shift of the resonance peak, and a narrowing of the effective vibration isolation frequency band. Meanwhile, the lower magnetic nut 13 is locked at the unstable equilibrium point of magnetic coupling, generating negative stiffness with the same amplitude but opposite direction to the parasitic positive stiffness based on the axial multistable magnetic coupling characteristics. The upper magnetic nut 10 and the lower magnetic nut 13 share the same magnetic screw 8, naturally forming a parallel relationship. Their relative displacements are completely synchronized, and the total system stiffness is the algebraic sum of the positive and negative stiffnesses, macroscopically achieving quasi-zero stiffness (QZS) characteristics, eliminating the negative impact of parasitic stiffness, preventing the resonance peak from shifting to higher frequencies, and widening the effective operating frequency band of the vibration isolation system, especially improving the vibration isolation capability in the ultra-low frequency band.

[0028] Traditional quasi-zero stiffness vibration isolators can only achieve quasi-zero stiffness under a single rated load and a fixed equilibrium position. Once the load mass changes and the system deviates from the designed equilibrium position, the vibration isolation performance deteriorates sharply. This device, relying on the multi-stable characteristics of the lower magnetic nut 13 and a rotatable locking rotating platform 14, achieves adaptive adaptation to any static load. When changing the load or adjusting the operating conditions, simply unlock the locking device, and the lower magnetic nut 13 will rotate freely with the rotating platform 14. Under the action of magnetic coupling force, it will automatically find a stable equilibrium point under the new load. Then, it will be finely adjusted to rotate to an unstable equilibrium point and locked, thus achieving precise stiffness compensation again at the new equilibrium position, always maintaining the optimal quasi-zero stiffness vibration isolation effect. No structural modifications are required, and the system is extremely robust. Specifically, after installing the system or changing the load, first loosen the locking device and allow the rotating platform 14 to rotate freely. At this time, the lower magnetic nut 13 will automatically find a new static equilibrium position. Then, the rotating platform 14 is rotated by a small angle (theoretically, the angle corresponding to half a magnetic pole moment) to bring it to an unstable equilibrium point, and finally the locking device is activated to fix it. In this way, the lower magnetic nut 13 can provide the system with a negative stiffness that is equal in magnitude and opposite in direction to the parasitic stiffness of the upper magnetic nut 10.

[0029] In some embodiments, the multi-stable composite vibration isolator further includes a guide shaft 3. The bottom end of the guide shaft 3 is fixedly mounted on the base 1, and the guide shaft 3 passes upward through the support platform 4 and the load platform 5 in sequence. The positions of the support platform 4 and the guide shaft 3 are relatively fixed, and the elastic element 7 is sleeved on the guide shaft 3. The guide shaft 3 strictly constrains the motion trajectory of the load platform 5, retaining only vertical single-degree-of-freedom translation, and restricting redundant degrees of freedom such as radial movement, deflection, and overturning. The non-contact magnetic coupling transmission of the dual magnetic screw unit relies entirely on the pure axial relative motion between the magnetic screw 8 and the upper magnetic nut 10 and the lower magnetic nut 13. Excessive radial / deflection motion will not only cause a sharp drop in magnetic coupling efficiency and inaccurate output of inertial capacitance damping and negative stiffness, but may even cause mechanical friction of the magnetic structure, damaging the working foundation of the vibration isolator. The elastic element 7 is directly sleeved on the guide shaft 3, and the guide shaft 3 provides full radial constraint for it, avoiding radial bending, instability, and torsional deformation problems that occur in the elastic element 7 during reciprocating compression / tension. The bottom end of the guide shaft 3 is fixed to the base 1, and the relative position of the support platform 4 is locked by the first support column, forming a stable assembly reference in which the base 1, support platform 4, and load platform 5 are coaxial and parallel.

[0030] In a preferred embodiment, a support 2 is provided at the bottom of the guide shaft 3, and a mounting hole is provided on the base 1. The support 2 is fixedly installed in the mounting hole, and the guide shaft 3 is fixedly connected to the support 2. The support 2 is embedded into the base 1 through the mounting hole, and the concentrated load of the guide shaft 3 is distributed and transferred to the hole wall and mounting surface of the base 1 through the support 2, thereby increasing the stress area, reducing the stress peak at the connection point, and reducing the risk of fatigue failure.

[0031] In some embodiments, the multi-stable composite vibration isolator further includes a first fixed seat 16, a second fixed seat 17, and a third fixed seat 6. The top of the guide shaft 3 extends through the load platform 5. The first fixed seat 16 is fixedly mounted on the support platform 4 and fixedly connected to the bottom of the elastic element 7. The second fixed seat 17 is fixedly mounted on the load platform 5 and fixedly connected to the middle of the elastic element 7. The third fixed seat 6 is fixedly mounted on the top of the guide shaft 3 and fixedly connected to the top of the elastic element 7. Both the first fixed seat 16 and the second fixed seat 17 are slidably sleeved on the guide shaft 3. The three fixed seats rigidly divide the elastic element 7, which is sleeved on the guide shaft 3, into a lower spring segment (support platform 4 - load platform 5) and an upper spring segment (load platform 5 - top of guide shaft 3), forming a bidirectional symmetrical constraint on the load platform 5. Regardless of whether the load platform 5 moves upward or downward, the elastic element 7 is in a controlled tension / compression working state throughout the entire process, and there will be no problems such as spring disengagement, movement idleness, or support failure. The bottom, middle, and top of the elastic element 7 are rigidly fixed to the mounting base, preventing slippage, movement, and installation gaps at the spring ends, ensuring that the linear support stiffness provided by the main vibration isolation system is continuous, stable, and controllable throughout the entire process. Facing common bidirectional vibration / impact conditions (vertical positive and negative acceleration and impact loads caused by bumps) in vehicles, aerospace, ships, and construction machinery, when the load platform 5 moves downwards, the lower spring compresses and the upper spring stretches to provide reverse constraint; when moving upwards, the upper spring compresses and the lower spring stretches to provide reverse constraint, with no constraint blind spots throughout the entire process, providing stable elastic restoring force and vibration suppression capability in both directions.

[0032] In some embodiments, the multi-stable composite vibration isolator further includes a first support column 15, with its two ends fixedly connected to the top surface of the base 1 and the bottom surface of the support platform 4, respectively. The support platform 4 is the core mounting carrier of the upper magnetic nut 10 and also the intermediate force-bearing node of the main vibration isolation system. The first support column 15 rigidly connects it to the base 1, preventing vertical movement, horizontal displacement, and warping deformation of the support platform 4. By making the support platform 4 a rigid reference surface integrated with the base 1, the axial fixing position and circumferential rotation constraint structure of the upper magnetic nut 10 are permanently locked, and there will be no positional displacement due to vibration or load changes. Without the support column, the force on the support platform 4 is only indirectly transmitted through the guide shaft 3, which is prone to stress concentration at the connection between the guide shaft 3 and the support platform 4. The addition of the first support column 15 realizes the uniform distribution and transmission of the load, directly bearing the weight of the support platform 4 itself, the entire load of the upper magnetic nut 10 unit, and part of the vibration reaction force transmitted in dynamic vibration isolation.

[0033] In some embodiments, the multi-stable composite vibration isolator further includes a second support column 12 and an auxiliary bearing platform 9. The two ends of the second support column 12 are fixedly connected to the top surface of the support platform 4 and the bottom surface of the auxiliary bearing platform 9, respectively. The auxiliary bearing platform 9 is located between the load platform 5 and the support platform 4. The bottom end of the upper magnetic nut 10 is rotatably connected to the support platform 4 via a first bearing, and the top end is rotatably connected to the auxiliary bearing platform via a second bearing. The bottom and top ends of the upper magnetic nut 10 are rigidly constrained between the support platform 4 and the auxiliary bearing platform 9 via the first and second bearings, respectively. Through this double-bearing, double-end constraint, only circumferential single-degree-of-freedom rotation is retained, restricting all redundant degrees of freedom such as radial movement, axial movement, tilting, and swaying. The rigid frame is linked with the first support column 15 to form a fully rigid fixed reference chain of base 1, first support column 15, support platform 4, second support column 12, and auxiliary bearing platform 9. The installation reference of the upper magnetic nut 10 has no flexible links throughout the entire process. Even under the conditions of high-frequency vibration and high-speed rotation of flywheel 11, there will be no elastic deformation of the support structure or offset of the installation reference. The axial fixed position of the upper magnetic nut 10 is locked, ensuring that its relative displacement with the magnetic screw 8 is determined only by the vertical vibration of the load platform 5 without additional interference.

[0034] In some embodiments, the outer wall of the magnetic screw 8 is helically arrayed with multiple first magnetic tiles 19, and the outer wall of the upper magnetic nut 10 is helically arrayed with multiple second magnetic tiles 20. The pitch and direction of rotation of the second magnetic tiles 20 are the same as those of the first magnetic tiles 19. Both the first magnetic tiles 19 and the second magnetic tiles 20 are radially magnetized in opposite directions. The lower magnetic nut 13 has the same structure as the upper magnetic nut 10. The design with the same pitch and direction of rotation ensures that the magnetic coupling trajectories of the magnetic screw 8 and the upper magnetic nut 10 are perfectly matched, and the vertical linear displacement of the screw corresponds linearly to the circumferential rotation angle of the nut. The continuous spiral array of magnetic tiles forms an axially and circumferentially coupled magnetic field, naturally possessing frequency-varying characteristics of strong low-frequency coupling and natural high-frequency decoupling. During low-frequency vibration, the magnetic field has sufficient time to complete coupling and energy transfer, driving the nut to rotate at high speed and generating high damping, effectively suppressing resonance peaks. During high-frequency vibration, the change in magnetic flux cannot keep up with the rapid reciprocating motion of the screw, the magnetic coupling efficiency decreases sharply, and the inertial damping effect disappears automatically. The upper and lower magnetic nuts have completely identical structures, ensuring that the magnetic tile parameters, the coupling gap with the magnetic screw 8, and the magnetic coupling mechanical characteristics are completely symmetrical. The parasitic positive stiffness generated by the upper magnetic inertial capacitance operation and the negative stiffness generated by the lower nut locked at an unstable equilibrium point have completely equal amplitudes and perfectly matched variation patterns. Based on the algebraic sum and superposition principle of parallel stiffness, the total system stiffness K... 总 =K 正 +K 负 ≈0, achieving a precise near-zero stiffness effect, avoiding problems such as system stiffness hardening, rightward shift of resonance peak, and narrowing of vibration isolation frequency band caused by parasitic stiffness.

[0035] In some embodiments, the counterweight device includes a flywheel 11 and a counterweight pin 18. The counterweight pin 18 is detachably mounted on the outer periphery of the flywheel 11, and the flywheel 11 is fixedly sleeved on the outer periphery of the upper magnetic nut 10. The inertial damping force output by the magnetic inertia capacitance is directly positively correlated with the rotational inertia of the flywheel 11. The larger the rotational inertia, the stronger the damping suppression capability in the low-frequency resonance region. The design of the detachable counterweight pin 18 eliminates the need to replace the flywheel 11 body. By simply increasing or decreasing the number of counterweight pins 18 and adjusting their installation position, the total rotational inertia of the flywheel 11 can be quickly and accurately adjusted, achieving a wide range of customized adjustment of the damping characteristics. The flywheel 11 is fixedly sleeved on the outer periphery of the upper magnetic nut 10, forming a coaxial integrated rotating body with the upper magnetic nut 10. This ensures high coaxiality and strong connection rigidity, avoiding the gap and slippage problems of split transmission, and ensuring that the rotational motion of the upper magnetic nut 10 is completely synchronized with the vertical motion of the magnetic screw 8.

[0036] In some embodiments, multiple first support columns 15, second support columns 12, guide shafts 3, and elastic elements 7 are evenly arranged around the magnetic screw 8. The evenly distributed first support columns 15 ensure complete symmetry of the installation reference from the base 1 to the support platform 4, strictly guaranteeing the levelness of the support platform 4 and its coaxiality with the magnetic screw 8, preventing local warping or offset. The evenly distributed second support columns 12 ensure uniform circumferential support rigidity from the support platform 4 to the auxiliary bearing platform 9, locking the coaxiality of the double-end bearings of the upper magnetic nut 10 and avoiding reference tilting caused by cantilever support and unilateral constraint. The evenly distributed guide shafts 3 form a multi-point closed-loop guide, strictly constraining the load platform 5 to only perform pure vertical single-degree-of-freedom translation, limiting radial movement, deflection, and overturning, and ensuring the verticality and linearity of the magnetic screw 8. The evenly distributed elastic elements 7 ensure completely uniform circumferential support rigidity, eliminating stiffness anisotropy and preventing unilateral sinking or attitude deviation of the load platform 5 under load.

[0037] In some embodiments, the elastic element 7 is a vibration isolation spring. The spring stiffness design offers high freedom; by adjusting the spring wire diameter, mean diameter, number of turns, and material grade, the stiffness value, load-bearing capacity, and deformation can be precisely customized to match the vibration isolation design requirements of different loads and natural frequencies. It can also achieve precise adaptation with the magnetic coupling characteristics and negative stiffness output characteristics of the dual-magnetic screw unit. Under dynamic vibration conditions, the vibration isolation spring provides stable elastic restoring force, which, combined with the frequency-varying damping characteristics of the magnetic inertial capacitance, dissipates and isolates vibration energy. Simultaneously, its dynamic stiffness does not change abruptly with frequency or amplitude, complementing the strong low-frequency coupling and high-frequency self-decoupling characteristics of the magnetic inertial capacitance. In the low-frequency range, resonance is suppressed by the magnetic inertial capacitance, while in the high-frequency range, rapid vibration attenuation is achieved by the spring, overcoming the waterbed effect of traditional vibration isolation.

[0038] It should be noted that the vibration isolation spring can be designed in two sections, and the two sections can be designed with different spring force coefficients as needed.

[0039] In some embodiments, the rotating platform 14 is a hollow rotary slide with a fine-tuning knob, specifically an R-axis hollow rotary slide manual precision fine-tuning 360° angle optical displacement platform indexing plate. The specific load-bearing weight can be designed according to needs. This R-axis hollow rotary slide is an optical-grade precision angle adjustment component, equipped with a high-precision fine-tuning knob and scale, which can directly realize the visualization and quantitative fine-tuning of the tiny angle corresponding to half a magnetic pole moment. After releasing the locking device of the slide itself, the table surface can achieve 360° smooth and non-jamming rotation without any mechanical limit interference, allowing the lower magnetic nut to rotate freely and quickly to the lowest stable equilibrium point of magnetic field potential energy corresponding to the new load under the action of magnetic coupling force, completing static balance self-adaptation and adapting to the position adjustment requirements of any load.

[0040] 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 multi-stable composite vibration isolator, characterized in that: Includes a main vibration isolation system and a dual magnetic screw unit, wherein; The main vibration isolation system includes a base, a support platform, a load platform, and an elastic element. The support platform is fixedly installed above the base, the load platform is located above the support platform, and the two ends of the elastic element are fixedly connected to the load platform and the support platform, respectively. The dual magnetic screw unit includes a magnetic screw, an upper magnetic nut, a lower magnetic nut, a counterweight device, and a rotating platform. The top of the magnetic screw is fixedly located at the center of the load platform, and the magnetic screw passes through the support platform, the upper magnetic nut, and the lower magnetic nut. The upper magnetic nut is sleeved on the magnetic screw and located between the support platform and the load platform. The counterweight device is fixedly located on the outer periphery of the upper magnetic nut. The upper magnetic nut and the support platform form a circumferentially rotating and axially fixed connection. The lower magnetic nut is sleeved on the magnetic screw and located between the base and the support platform. The lower magnetic nut is fixedly located on the rotating platform, which is rotatably mounted on the base. The rotating platform itself has a locking device. The lower magnetic nut and the magnetic screw are at an unstable equilibrium point of axial magnetic force.

2. The multi-stable composite vibration isolator according to claim 1, characterized in that: It also includes a guide shaft, the bottom end of which is fixedly mounted on the base, and the guide shaft passes upward through the support platform and the load platform in sequence. The support platform and the guide shaft are fixed in relative position, and the elastic element is sleeved on the guide shaft.

3. The multi-stable composite vibration isolator according to claim 2, characterized in that: It also includes a first fixed seat, a second fixed seat, and a third fixed seat. The top of the guide shaft extends through the load platform. The first fixed seat is fixedly disposed on the support platform and fixedly connected to the bottom of the elastic element. The second fixed seat is fixedly disposed on the load platform and fixedly connected to the middle of the elastic element. The third fixed seat is fixedly disposed on the top of the guide shaft and fixedly connected to the top of the elastic element. Both the first fixed seat and the second fixed seat are slidably sleeved on the guide shaft.

4. The multistable composite vibration isolator according to claim 2, characterized in that: It also includes a first support column, the two ends of which are fixedly connected to the top surface of the base and the bottom surface of the support platform, respectively.

5. The multi-stable composite vibration isolator according to claim 4, characterized in that: It also includes a second support column and an auxiliary bearing platform. The two ends of the second support column are fixedly connected to the top surface of the support platform and the bottom surface of the auxiliary bearing platform, respectively. The auxiliary bearing platform is located between the load platform and the support platform. The bottom end of the upper magnetic nut is rotatably connected to the support platform through a first bearing, and the top end is rotatably connected to the bearing auxiliary platform through a second bearing.

6. The multistable composite vibration isolator according to claim 1, characterized in that: The outer wall of the magnetic screw has a spiral array of multiple first magnetic tiles, and the outer wall of the upper magnetic nut has a spiral array of multiple second magnetic tiles. The pitch and direction of the second magnetic tiles are the same as those of the first magnetic tiles. Both the first and second magnetic tiles are radially magnetized, and the magnetization directions are opposite. The lower magnetic nut has the same structure as the upper magnetic nut.

7. The multi-stable composite vibration isolator according to claim 1, characterized in that: The counterweight device includes a flywheel and a counterweight pin. The counterweight pin is detachably disposed on the outer periphery of the flywheel, and the flywheel is fixedly sleeved on the outer periphery of the upper magnetic nut.

8. The multi-stable composite vibration isolator according to claim 5, characterized in that: The first support column, the second support column, the guide shaft, and the elastic element are all evenly arranged in multiples around the magnetic screw.

9. The multi-stable composite vibration isolator according to claim 1, characterized in that: The elastic element is a vibration isolation spring.

10. The multistable composite vibration isolator according to claim 1, characterized in that: The rotating platform is a hollow rotary slide with a fine-tuning knob.

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