Electro-permanent magnetic quasi-zero stiffness damper

Abstract

This invention discloses an electro-permanent magnet quasi-zero stiffness vibration damper, relating to the field of vibration control technology. The device includes a frame body and an inertial coupling joint. The linkage assembly of the frame body converts vertical linear displacement into angular displacement at the hinge point through a hinge node. The inertial coupling joint is coaxially arranged with the hinge axis and consists of connecting rods on both sides and coaxially spaced circular and semi-circular rings. A permanent magnet is mounted on the circular ring, and an electromagnetic structure composed of a hard magnetic core, a soft magnetic core, and an excitation coil is mounted on the semi-circular ring. Adjustable torsional negative stiffness is generated through magnetic coupling, which, after conversion by the linkage mechanism, matches the positive stiffness to achieve quasi-zero stiffness low-frequency vibration isolation. The high-frequency vibration isolation performance is improved by relying on the inertial capacitance effect of the inertial coupling mass. Stiffness adjustment can be completed with only a pulse current, and after adjustment, a stable working state is maintained by residual magnetism. It has the advantages of large stroke, wide-frequency vibration isolation, and low energy consumption, and can adapt to complex and varied vibration conditions.

Description

Technical Field

[0001] This invention relates to the field of vibration control technology, and in particular to an electro-permanent magnet quasi-zero stiffness vibration damper. Background Technology

[0002] In recent decades, the marine industry has experienced rapid development, with applications covering oil and gas exploration, production, storage and transportation; ocean and wind energy harvesting and utilization; radar surveillance; aerospace operations; oceanographic research, and many other areas. Due to the unique characteristics of the marine environment, offshore structures, in addition to bearing their own static loads, dynamic loads, and incidental loads, are also subjected to multi-source dynamic environmental loads such as waves, sea winds, and ocean currents, leading to continuous structural vibrations. Stable and reliable working conditions are the fundamental prerequisite for the sustainable development of the marine industry; therefore, vibration control in the marine environment presents higher technical requirements and engineering complexity compared to terrestrial scenarios. Vibration control generally refers to vibration suppression, which involves regulating the dynamic response or instability of the system to limit the vibration level to a minimum or permissible range. Currently, the main way to avoid resonance risks in engineering is to install vibration isolation devices, which can be divided into three categories according to their working principles: active vibration isolation, semi-active vibration isolation, and passive vibration isolation.

[0003] The vibration suppression effect of passive vibration isolation systems originates from the structure's own vibration energy dissipation mechanism, requiring no external energy input. They offer advantages such as strong adaptability to various operating conditions, high operational stability, long service life, and easy maintenance, leading to their widespread application across various industries. However, due to inherent structural properties, single passive vibration isolation structures often struggle to achieve broadband vibration isolation effects, and their structural parameters cannot be dynamically adjusted after completion, resulting in significant performance limitations in complex environments with multiple excitation couplings.

[0004] Active vibration isolation systems consist of sensors and actuators, relying on a continuous external power supply. Their core working principle involves collecting vibration signals through sensors, processing them using a control algorithm, and then outputting control commands to the actuators to actively counteract structural vibrations. These systems can effectively suppress multi-frequency vibration excitation and offer excellent vibration isolation. However, due to the limitations of the "signal acquisition-processing-output execution" workflow, they suffer from response delays and a strong dependence on continuous energy supply, resulting in high energy consumption and costs.

[0005] Semi-active vibration isolation systems can adjust their structural properties in real time with minimal external power to match dynamic excitation. Their vibration isolation performance is better than that of traditional passive vibration isolation structures, and their dependence on external energy is lower than that of active vibration isolation systems. However, they still cannot operate independently without external energy and are difficult to adapt to application scenarios without continuous power supply.

[0006] In the field of marine engineering, in addition to large offshore structures, numerous miniaturized and highly maneuverable offshore operational devices place stringent requirements on the stability of their work platforms. In such applications, active vibration isolation systems cannot achieve long-term stable operation, traditional passive vibration isolation systems cannot adapt to the complex and ever-changing marine excitation conditions, and semi-active vibration isolation systems still suffer from energy dependence. Existing vibration isolation technologies struggle to simultaneously meet the multiple demands of low energy consumption, wide adaptability to various operating conditions, and stable and reliable operation. Therefore, developing a novel vibration isolation device with low energy consumption and dynamically adjustable vibration isolation performance is a pressing technical problem to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide an electro-permanent magnet quasi-zero stiffness vibration damper to solve the problems existing in the prior art. It can achieve high-efficiency vibration isolation in a wide frequency range, and take into account the vibration suppression effect in both low and high frequency bands. It is suitable for complex vibration conditions with multiple amplitudes and frequencies. The vibration isolation performance can be dynamically adjusted to match different loads and excitation conditions. The adjustment process has low energy consumption. After the adjustment is completed, it can effectively and stably maintain the working state, reducing operating energy consumption and power supply dependence. At the same time, it has the advantages of stable and reliable operation, long service life, and simple maintenance.

[0008] To achieve the above objectives, the present invention provides the following solution: an electro-permanent magnet quasi-zero stiffness vibration damper, comprising a frame body and at least one set of inertial coupling joints; The main frame includes a top plate, a bottom plate, a connecting rod assembly, and an elastic support member; the connecting rod assembly includes multiple connecting rods and a hinge shaft, the inner end of each connecting rod is hinged to the hinge shaft, and the outer end of each connecting rod is respectively hinged to the top plate or the bottom plate; the elastic support member is disposed between the top plate and the bottom plate, and the elastic support member is used to provide positive support stiffness. The inertial coupling joint is coaxially arranged with the hinge axis. The inertial coupling joint includes a circular ring and a semi-circular ring arranged coaxially at intervals. The circular ring is connected to one of the sets of connecting rods and a permanent magnet is provided on the circular ring. The semi-circular ring is connected to the other set of connecting rods and at least one set of electromagnetic structures is installed on the semi-circular ring. Each set of electromagnetic structures includes a hard magnetic core, a soft magnetic core, and an excitation coil. The hard magnetic core and the soft magnetic core are axially connected, and the excitation coil is nested outside the hard magnetic core and the soft magnetic core.

[0009] In one embodiment, two hinge shafts are provided, namely a first hinge shaft and a second hinge shaft; the connecting rod assembly includes a first connecting rod, a second connecting rod, a third connecting rod, and a fourth connecting rod; the inner ends of the first connecting rod and the second connecting rod are hinged to the first hinge shaft via miniature bearings, and the inner ends of the third connecting rod and the fourth connecting rod are hinged to the second hinge shaft via miniature bearings; the outer ends of the first connecting rod and the fourth connecting rod are hinged to the side of the top plate via connectors, and the outer ends of the second connecting rod and the third connecting rod are hinged to the side of the bottom plate via connectors.

[0010] In one embodiment, the miniature bearing is sleeved on the outside of the rod body of the corresponding hinge shaft, and the ends of each connecting rod are respectively engaged and fixed with the outer ring of the corresponding miniature bearing.

[0011] In one embodiment, the permanent magnet is a tile-shaped permanent magnet, which is fixed to the inner wall of the ring.

[0012] In one embodiment, the magnetization direction of the hard magnetic core and the soft magnetic core is the same, and the magnetic poles of the hard magnetic core and the soft magnetic core both point to the coaxial center of the circular ring and the semi-circular ring.

[0013] As one embodiment, each set of electromagnetic structures further includes a magnetically permeable outer shell, which is sleeved on the outside of the excitation coil.

[0014] As one embodiment, a cylindrical mounting hole is provided on the semi-circular ring, and the electromagnetic structure is embedded in the cylindrical mounting hole; a wiring through hole is provided at the bottom of the magnetic permeable shell and at the corresponding position of the semi-circular ring, and the external wire of the excitation coil passes through the wiring through hole.

[0015] As one embodiment, two sets of electromagnetic structures are installed on the semicircular ring. The two sets of electromagnetic structures are symmetrically distributed about the central axis of the semicircular ring, and the included angle between the axes of the two sets of electromagnetic structures is 90°.

[0016] As one embodiment, the frame body further includes a linear guide assembly, which includes a linear bearing, a flange, and a bearing housing; the flange is fixed to the lower surface of the top plate, the bearing housing is fixed to the upper surface of the bottom plate, and the linear bearing is vertically mounted on the flange; the elastic support is a linear spring, which is sleeved on the outside of the linear bearing.

[0017] In one embodiment, the semicircular ring and the circular ring are arranged coaxially and nested together, with a radial gap reserved between the semicircular ring and the circular ring.

[0018] The present invention achieves the following technical effects compared to the prior art: This invention constructs a positive support system through the cooperation of a connecting rod assembly and an elastic support component. An inertial coupling joint is coaxially integrated at the hinge node within the connecting rod, fixing the circular ring and semi-circular ring to the connecting rods on both sides. The permanent magnet on the circular ring and the electromagnetic structure on the semi-circular ring are coupled through an air gap magnetic field to generate torsional negative stiffness, which is then equivalently converted into vertical negative stiffness by the connecting rod mechanism. This negative stiffness is matched and canceled out by the positive stiffness of the elastic support component near the equilibrium position, forming a quasi-zero stiffness range to achieve low-frequency, high-efficiency vibration isolation. Simultaneously, a hard magnetic core provides a constant basic magnetic field. By applying pulse current to the excitation coil to change the magnetization intensity and magnetic pole direction of the soft magnetic core, the amplitude of the torsional negative stiffness can be continuously adjusted, achieving dynamic control of the vibration isolation performance. Furthermore, the circular ring, semi-circular ring, and their supporting magnetic circuit components, which rotate synchronously with the connecting rod, together constitute a rotational inertial coupling mass. The inertial capacitance effect is used to impede the transmission of high-frequency vibrations, compensating for the high-frequency vibration isolation performance defects of traditional quasi-zero stiffness structures.

[0019] This application effectively addresses the shortcomings of existing vibration isolation technologies in adapting to small-scale marine operations: negative stiffness adjustment requires only a brief pulse current drive, and after magnetization, the residual magnetism of the soft magnetic core can maintain a stable working state for a long time without continuous energy input, reducing energy consumption and power supply dependence; by covering low-frequency vibration isolation through a quasi-zero stiffness mechanism and compensating for high-frequency performance through inertial capacitance effect, a wide-frequency domain vibration isolation effect can be achieved within a single structure; at the same time, the scissor telescopic structure of the connecting rod can accommodate large vertical displacements in a compact size, adapting to complex vibration conditions with multiple amplitudes and frequencies in the marine environment; the overall passive mechanical frame is the main body, combining the advantages of high stability and easy maintenance of passive vibration isolation systems, while also having the ability to adapt to working conditions, which can better meet the stable working requirements of complex marine environments. Attached Figure Description

[0020] 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.

[0021] Figure 1 This is a partial sectional view of the overall structure of the present invention from the main view. Figure 2 This is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 3 This is a partial cross-sectional perspective view of the overall structure of the present invention; Figure 4 This is a schematic diagram of the front sectional view of the present invention; Figure 5 This is a schematic diagram of the linkage assembly of the present invention; Figure 6This is a schematic diagram showing the arrangement and polarization direction of the magnets and coils in this invention; Figure 7 This is a schematic diagram of the torque-rotation angle characteristic curve of the electro-permanent magnet negative stiffness unit of the present invention. Figure 8 This is a schematic diagram of the torsional stiffness-rotation angle characteristic curve of the electro-permanent magnet negative stiffness unit of the present invention. Figure 9 This is a schematic diagram illustrating the working principle of an electro-permanent magnet low-energy-consumption, long-stroke, near-zero-stiffness vibration damper.

[0022] Among them, (a) is a schematic diagram of the overall structural principle of the shock absorber; (b) is a schematic diagram of the static cross-sectional structure of the inertial coupling joint; (c) is a schematic diagram of the dynamic working state of the inertial coupling joint; and (d) is a schematic diagram of the motion displacement conversion principle of the linkage mechanism.

[0023] Among them, 1. Top slab; 2. Bottom slab; 3. Linkage assembly; 301. First link; 302. Second link; 303. Third link; 304. Fourth link; 4. Elastic support component; 5. Circular ring; 6. Semi-circular ring; 7. Permanent magnet; 8. Hard magnetic core; 9. Soft magnetic core; 10. Hinge shaft; 101. First hinge shaft; 102. Second hinge shaft; 11. Excitation coil; 12. Miniature bearing; 13. Connector; 14. Flange; 15. Bearing housing; 16. Spring retaining ring; 17. Linear bearing; 18. Magnetic housing. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] This embodiment provides an electro-permanent magnet quasi-zero stiffness vibration damper. Please refer to [reference needed]. Figure 1 - Figure 9As shown, this electro-permanent magnet quasi-zero stiffness vibration damper includes a frame body and at least one set of inertial coupling joints. The frame body includes a top plate 1, a bottom plate 2, a connecting rod assembly 3, and an elastic support member 4. The connecting rod assembly 3 includes multiple connecting rods and a hinge shaft 10. The inner end of each connecting rod is hinged to the hinge shaft 10. Preferably, the connecting rod assembly 3 is a rhomboid connecting rod assembly, and any connecting rod has a rhomboid side. The outer end of each connecting rod is correspondingly hinged to the side of the top plate 1 or the bottom plate 2. Multiple connecting rods can jointly form a scissor support structure that can extend and retract vertically. This structure converts vertical linear displacement into angular displacement at the hinge shaft 10 through the swing of the connecting rods, thereby achieving a large vertical vibration stroke within a compact axial dimension. The elastic support member 4 is vertically arranged between the top plate 1 and the bottom plate 2. The elastic support member 4 is used to provide positive support stiffness and static load bearing capacity for the vibration damper. The elastic support member 4 is preferably a positive stiffness elastic member.

[0027] The inertial coupling joint is coaxially arranged with the hinge axis 10. The inertial coupling joint includes a circular ring 5 and a semi-circular ring 6 arranged coaxially at intervals. The circular ring 5 is fixedly connected to a connecting rod on one side, and a permanent magnet 7 is provided on the inner wall of the circular ring 5. The semi-circular ring 6 is fixedly connected to a connecting rod on the other side, and at least one set of electromagnetic structures is installed on the semi-circular ring 6. Each set of electromagnetic structures includes a hard magnetic core 8, a soft magnetic core 9, and an excitation coil 11. The hard magnetic core 8 and the soft magnetic core 9 are aligned radially and axially along the circular ring and have the same magnetization direction, with their magnetic poles pointing towards the center of the circular ring. The excitation coil 11 is nested outside the hard magnetic core 8 and the soft magnetic core 9. The hard magnetic core 8 is used to provide a constant basic magnetic field. The soft magnetic core 9 can change its magnetization intensity and magnetic pole direction through the pulse current supplied to the excitation coil 11, and couples with the permanent magnet 7 through the air gap magnetic field to generate an adjustable torsional negative stiffness.

[0028] When external vertical vibration acts on the top plate 1 or the bottom plate 2, it can drive the connecting rod assembly 3 to produce shear-like expansion and contraction deformation, causing the connecting rods on both sides to rotate relative to each other around the hinge axis 10, which in turn causes the circular ring 5 and the semi-circular ring 6 to rotate coaxially relative to each other; the permanent magnet 7 and the electromagnetic structure generate torsional negative stiffness through air gap magnetic field coupling, which is equivalently converted into vertical negative stiffness through the connecting rod mechanism, and matched in parallel with the positive stiffness provided by the elastic support 4, forming a quasi-zero stiffness range near the equilibrium position, thereby achieving efficient isolation of low-frequency vibration.

[0029] When operating conditions change, a pulse current is applied to the excitation coil 11 to alter the magnetization state of the soft magnetic core 9. When the soft and hard magnetic fields superimpose in the same direction, the total magnetic field strengthens, thereby increasing the absolute value of the negative stiffness. When they cancel each other out in opposite directions, the total magnetic field weakens, and the absolute value of the negative stiffness decreases, thus adapting to different loads and excitation conditions. After adjustment, the power supply can be cut off. The soft magnetic core 9 maintains its magnetization state long-term due to residual magnetism, eliminating the need for continuous energy input and achieving stable low-energy operation.

[0030] Meanwhile, the circular ring 5, the semi-circular ring 6 and the permanent magnet 7 on it together with the electromagnetic structure constitute an inertial coupling mass, which generates an inertial capacitance effect when rotating relative to each other, which can suppress the transmission of high-frequency vibration and improve the defect of the deterioration of high-frequency vibration isolation performance of traditional quasi-zero stiffness structures.

[0031] Working method: Specifically includes the following steps: Step 1: Constructing the initial quasi-zero stiffness equilibrium state This step is the static debugging phase, used to establish the initial working base point of the vibration damper. The specific process is as follows: Complete the overall mechanical assembly of the shock absorber, and adjust the pre-compression of the elastic support 4 according to the preset load, so that the elastic support 4 provides stable static load support for the top plate 1 and the load above it, while outputting constant positive stiffness.

[0032] A pulse current with preset parameters is passed into the excitation coil 11 to magnetize the soft magnetic core 9. After the soft magnetic core 9 is magnetized, it works together with the basic magnetic field of the hard magnetic core 8. The electromagnetic structure and the permanent magnet 7 on the ring 5 are coupled through the air gap magnetic field to generate initial torsional negative stiffness.

[0033] By finely adjusting the parameters of the pulse current and changing the magnetization intensity of the soft magnetic core 9, the vertical negative stiffness, which is equivalently converted from the torsional negative stiffness by the connecting rod assembly 3, is approximately canceled out by the positive stiffness provided by the elastic support 4 near the equilibrium position. The total stiffness of the system approaches zero, thus completing the construction of the quasi-zero stiffness initial state.

[0034] After the magnetization calibration is completed, the power supply to the excitation coil 11 can be directly cut off; the soft magnetic core 9 maintains its current magnetization state for a long time by relying on its own residual magnetism, and can stably maintain negative stiffness characteristics without continuous energy input.

[0035] Step 2: Full-band dynamic vibration isolation operation When external vertical vibration excitation is applied to the vibration damper, the system achieves broadband vibration isolation through linkage motion conversion and multi-mechanism coordination. The specific process is as follows: Motion transmission and displacement conversion: When external vertical vibration acts on the top plate 1 or the bottom plate 2, the connecting rod assembly 3 produces shear-like expansion and contraction deformation, and each connecting rod swings synchronously around the hinge axis 10, converting the vertical linear displacement into a relative angular displacement at the hinge axis 10; the circular ring 5 and the semi-circular ring 6, which are fixed to the connecting rods on both sides respectively, rotate coaxially relative to each other, causing the permanent magnet 7 and the electromagnetic structure to produce a continuous relative rotation angle.

[0036] Low-frequency quasi-zero stiffness vibration isolation: When the vibration displacement is near the equilibrium position, the total stiffness of the system approaches zero, and the natural frequency is much lower than the low-frequency excitation frequency, which can effectively avoid the resonance range and thus significantly attenuate the transmission of low-frequency vibration, achieving high-efficiency low-frequency vibration isolation; at the same time, the scissor-type telescopic structure of the connecting rod assembly 3 can accommodate a large vertical displacement in a compact axial dimension, adapting to large amplitude vibration conditions.

[0037] High-frequency inertial capacitance vibration reduction compensation: The circular ring 5, the semi-circular ring 6 and the permanent magnet 7 and electromagnetic structure on them together constitute the rotational inertial coupling mass, which generates an inertial capacitance effect during relative rotation; under high-frequency vibration, the rotational inertia will hinder the transmission of high-frequency angular displacement, effectively reducing the high-frequency vibration transmission rate, making up for the defect of the deterioration of high-frequency vibration isolation performance of traditional quasi-zero stiffness structures, and achieving broadband stable vibration isolation.

[0038] Step 3: Adaptive stiffness adjustment under low-energy conditions When the operating conditions change (load weight changes, excitation frequency / amplitude fluctuates), the negative stiffness is dynamically adjusted through pulse-type magnetic modulation to rematch the positive and negative stiffness and maintain the quasi-zero stiffness vibration isolation effect. The specific process is as follows: A pulse current with corresponding parameters is supplied to the excitation coil 11 to change the magnetization degree of the soft magnetic core 9, thereby adjusting the magnitude of the magnetic coupling force between the electromagnetic structure and the permanent magnet 7, which can achieve continuous adjustment of the torsional negative stiffness. After the torsional negative stiffness is equivalently transformed by the linkage mechanism, it can be rematched with the positive stiffness under the current working condition to maintain the quasi-zero stiffness vibration isolation state.

[0039] Each stiffness adjustment only requires a brief pulse of electrical energy, and the power supply to the excitation coil 11 can be cut off after the adjustment is completed. The soft magnetic core 9 can maintain the adjusted magnetization state stably for a long time by relying on its own residual magnetism, without the need for continuous energy input, thus achieving low-energy self-adaptive operation.

[0040] In one embodiment, the linkage assembly 3 includes a first linkage 301, a second linkage 302, a third linkage 303, and a fourth linkage 304, which together form a vertically extendable rhomboid scissor support structure. There are two hinge shafts 10, including a first hinge shaft 101 and a second hinge shaft 102.

[0041] The linkage assembly 3 has two sets of opposing internal hinge nodes, with a first hinge shaft 101 and a second hinge shaft 102 respectively located at each set of internal hinge nodes. The inner ends of the first connecting rod 301 and the second connecting rod 302 are hinged to the first hinge shaft 101 via miniature bearings 12. The inner ends of the third connecting rod 303 and the fourth connecting rod 304 are hinged to the second hinge shaft 102 via miniature bearings 12. The miniature bearings 12 are sleeved on the outer side of the rod body corresponding to the hinge shaft 10, and the ends of each connecting rod are fixed to the outer ring of the miniature bearing 12, allowing each connecting rod to swing smoothly around the axis of the corresponding hinge shaft.

[0042] The two sets of external hinged ends of the linkage assembly 3 are respectively hinged to the top plate 1 and the bottom plate 2 through the connector 13: the outer end of the first link 301 and the outer end of the fourth link 304 are respectively hinged to the side of the top plate 1 through the connector 13; the outer end of the second link 302 and the outer end of the third link 303 are respectively hinged to the side of the bottom plate 2 through the connector 13.

[0043] This rhomboid scissor linkage structure can convert the vertical linear displacement between the top plate 1 and the bottom plate 2 into the swing angular displacement of the linkages at the two sets of inner hinge nodes around the hinge axis 10. It can achieve a large vertical vibration stroke in a compact axial space, which is suitable for the working conditions of large amplitude vibration isolation.

[0044] In one embodiment, the inertial coupling joint includes a circular ring 5 and a semi-circular ring 6, which are arranged coaxially and spaced apart. The circular ring 5 and the semi-circular ring 6 together constitute the load-bearing and guiding structure of the electro-permanent magnet negative stiffness unit, which is used to fix the magnetic circuit components and limit their relative rotational motion trajectory, thereby ensuring the overall working stability of the vibration damper.

[0045] The permanent magnet 7 is a tile-shaped permanent magnet. The inner and outer diameters of the tile-shaped permanent magnet are adapted to the inner wall size of the ring 5. The tile-shaped permanent magnet is attached and fixed to the inner wall surface of the ring 5. The ring 5 is fixed to a connecting rod on one side. The ring 5 can rotate synchronously with the connecting rod on that side around the corresponding hinge axis 10.

[0046] Two sets of symmetrically arranged electromagnetic structures are mounted on the semi-circular ring 6. Each set of electromagnetic structures includes a hard magnetic core 8, a soft magnetic core 9, an excitation coil 11, and a magnetically permeable outer shell 18. The hard magnetic core 8 and the soft magnetic core 9 have the same diameter and are joined together along the radial axis of the semi-circular ring 6. The magnetization directions of the hard magnetic core 8 and the soft magnetic core 9 are consistent, and their magnetic poles both point to the coaxial center of the circular ring 5 and the semi-circular ring 6. The inner diameter of the excitation coil 11 is adapted to the outer diameter of the joined magnetic core, and the axial height of the excitation coil 11 is consistent with the overall height of the joined hard magnetic core 8 and soft magnetic core 9. The excitation coil 11 is sleeved on the outside of the joined magnetic core.

[0047] The inner diameter of the magnetic housing 18 is adapted to the outer diameter of the excitation coil 11, and the axial height of the inner side of the magnetic housing 18 is consistent with the height of the excitation coil 11; preferably, the magnetic housing 18 is made of pure iron. A cylindrical mounting hole adapted to the outer diameter and height of the electromagnetic structure is provided on the semi-circular ring 6, and the assembled electromagnetic structure is embedded and fixed in the cylindrical mounting hole. Symmetrically arranged wiring through holes are provided at the bottom of the magnetic housing 18 and corresponding positions of the semi-circular ring 6, through which the external wires of the excitation coil 11 are led out. The semi-circular ring 6 is fixed to a connecting rod on the other side and can rotate synchronously with the connecting rod around the corresponding hinge axis 10.

[0048] In one embodiment, the frame body further includes a linear guide assembly and an elastic support assembly for providing vertical motion guidance and positive stiffness support for the shock absorber.

[0049] The linear guide assembly includes a flange 14, a bearing housing 15, and a linear bearing 17. The top plate 1 has threaded holes machined on its surface, and the flange 14 is fastened to the lower surface of the top plate 1 by bolts. The bottom plate 2 has threaded holes machined on its surface, and the bearing housing 15 is fastened to the upper surface of the bottom plate 2 by bolts. The linear bearing 17 is vertically mounted on the flange 14, and the lower end of the linear bearing 17 slides with the bearing housing 15, providing guidance for the relative vertical movement of the top plate 1 and the bottom plate 2.

[0050] The elastic support 4 is a linear spring, which is sleeved on the outside of the rod of the linear bearing 17. The inner diameter of the linear spring is slightly larger than the outer diameter of the linear bearing 17, and the outer diameter of the linear spring is smaller than the outer diameter of the spring retainer 16. The upper end of the linear spring abuts against the lower surface of the top plate 1, and the lower end of the linear spring abuts against the spring retainer 16. The spring retainer 16 is fixed to the rod of the linear bearing 17 by its own locking bolt, and its installation position is determined according to the support load requirements and the balance position calculation.

[0051] Both the top plate 1 and the bottom plate 2 have threaded holes machined on their sides, and the end of the connector 13 is provided with external threads. The connector 13 is fastened to the side of the top plate 1 or the bottom plate 2 through threaded engagement. The inner and outer ends of each connecting rod are hinged through miniature bearings 12: the inner end of the fourth connecting rod 304 is hinged to the corresponding hinge shaft 10 through miniature bearings 12, and the outer end is hinged to the corresponding connector 13 through miniature bearings 12; the first connecting rod 301, the second connecting rod 302, and the third connecting rod 303 are all hinged to the corresponding hinge shaft 10 and the corresponding connector 13 in the same way.

[0052] The main frame provides structural support for the entire shock absorber, and at the same time, the main frame can provide an installation reference for the inertial coupling joint; the linear spring and the connecting rod assembly 3 work together to provide the shock absorber with stable positive support stiffness and static load bearing capacity.

[0053] In one embodiment, two sets of linkage assemblies 3 are provided, symmetrically arranged at intervals along the axial direction of the hinge shaft 10. The two sets of linkage assemblies 3 can share a first hinge shaft 101 and a second hinge shaft 102. The two ends of the first hinge shaft 101 are respectively hinged to the inner ends of the connecting rods on the same side of both sets of linkage assemblies 3, and the two ends of the second hinge shaft 102 are respectively hinged to the inner ends of the connecting rods on the other side of both sets of linkage assemblies 3. Each set of linkage assemblies 3 includes a first connecting rod 301, a second connecting rod 302, a third connecting rod 303, and a fourth connecting rod 304. The four connecting rods together form a vertically expandable rhomboid scissor-type support structure. This dual-set parallel linkage layout improves the overall support stiffness and motion stability of the frame body, preventing lateral swaying during vibration damping, thereby ensuring the working stability of the vibration damper.

[0054] In one embodiment, the inertial coupling joint serves the dual purpose of inertial capacitance damping and negative stiffness element load bearing. Its working principle and technical effects are as follows: The circular ring 5, the semi-circular ring 6, and the permanent magnet 7 mounted on them together with the electromagnetic structure constitute a rotational inertial coupling mass. When the connecting rod assembly 3 swings around the hinge axis 10, the inertial coupling mass rotates synchronously with the connecting rods on both sides, generating an inertial capacitance effect and realizing the mass amplification effect, which can suppress low-frequency vibration.

[0055] Meanwhile, the inertial coupling joint integrates an electro-permanent magnet negative stiffness unit, which is composed of a permanent magnet 7 on the circular ring 5 and an electromagnetic structure on the semi-circular ring 6. The torsional negative stiffness generated by this unit is converted into vertical negative stiffness through the connecting rod assembly 3, which matches the positive stiffness provided by the elastic support 4. This can form a quasi-zero stiffness range near the equilibrium position, further improving the isolation effect of low-frequency vibration.

[0056] In addition, the inertial capacitance effect generated by the rotating inertial coupling mass can effectively improve the high-frequency vibration isolation performance degradation problem of traditional quasi-zero stiffness vibration isolation structures, broaden the effective operating frequency band of the vibration damper, and improve the device's adaptability to operating conditions.

[0057] The electro-permanent magnet negative stiffness unit can magnetize or demagnetize the soft magnetic core 9 by passing a pulse current through the excitation coil 11, thereby changing the magnetization intensity of the soft magnetic core 9 and adjusting the magnitude of the electromagnetic force between the electromagnetic structure and the permanent magnet 7 to obtain different stable negative stiffness values. This adjustment process can be completed by only briefly passing a pulse of electrical energy. After the adjustment is completed, the soft magnetic core 9 maintains a stable magnetization state by relying on its own residual magnetism, without the need for continuous energy input, and can adapt to various loads and vibration conditions with low energy consumption.

[0058] In one embodiment, the dimensional parameters of each part are all in millimeters (mm), and the specific parameters are as follows: The top plate 1 has a planar dimension of 120×340mm, and the bottom plate 2 has a planar dimension of 120×340mm; The length of each link in link assembly 3 is 100mm; The inner diameter of ring 5 is 10mm, the outer diameter is 18mm, and the axial thickness is 20mm; The permanent magnet 7 is a tile-shaped permanent magnet with an inner diameter of 10mm, an outer diameter of 18mm, an axial thickness of 16mm, and a central angle of 60°. The inner diameter of the semicircular ring 6 is 20mm, the outer diameter is 40mm, and the axial thickness is 20mm; The soft magnetic core 9 has a diameter of 10mm and an axial height of 10mm; The diameter of the hard magnetic core 8 is 10mm and the axial height is 6mm; The inner diameter of the excitation coil 11 is 5mm, the outer diameter is 8mm, and the axial height is 16mm; The magnetic housing 18 has an inner diameter of 8 mm, an outer diameter of 9 mm, and an axial height of 17 mm. Two sets of electromagnetic structures are installed on the semicircular ring 6. The two sets of electromagnetic structures are symmetrically distributed about the central axis of the semicircular ring 6, and the included angle between the axes of the two sets of electromagnetic structures is 90°.

[0059] It should be noted that this technical solution is not limited to the rhomboid linkage structure described in this embodiment. The linkage structure can also be extended to the hinge nodes of linkage mechanisms between any two parallel planes, including but not limited to L-shaped linkage joints, double linkage joints, and other structural forms. The elastic support 4 can also adopt other types of positive stiffness support structures according to different working conditions. As long as the negative stiffness and positive stiffness are matched, the technical effect of quasi-zero stiffness vibration isolation can be achieved.

[0060] In one embodiment, reference Figure 9 As shown, Figure 9 As shown in Figures (a) to (d), the electro-permanent magnet low-energy-consumption and long-stroke quasi-zero stiffness vibration damper of this embodiment adopts a scissor-linkage integrated layout, wherein... Figure 9 (a) is a schematic diagram of the overall structure of the shock absorber. A connecting rod assembly 3 and an elastic support 4 are vertically arranged between the top plate 1 and the bottom plate 2. Inertial coupling joints are coaxially installed at the two sets of internal hinge nodes of the connecting rod assembly 3. Figure 9 (b) is a schematic diagram of the static cross-sectional structure of the inertial coupling joint. The inertial coupling joint is composed of a circular ring 5 and a semi-circular ring 6 arranged coaxially. A permanent magnet 7 is fixed on the inner wall of the circular ring 5. An electromagnetic structure is embedded in the semi-circular ring 6. Each electromagnetic structure consists of a hard magnetic core 8 and a soft magnetic core 9 connected axially, an excitation coil 11 sleeved on the outside of the two, and a magnetic permeable shell 18 wrapped on the outermost side. The permanent magnet 7 and the electromagnetic structure form a magnetic field coupling through a radial air gap. Figure 9(c) is a schematic diagram of the dynamic working state of the inertial coupling joint. When the connecting rods on both sides swing relative to each other, the circular ring 5 and the semi-circular ring 6 generate a relative rotation angle around the hinge axis 10. The magnetic coupling force changes with the rotation angle to generate continuous torsional negative stiffness. Figure 9 (d) is a schematic diagram of the motion conversion of the vibration damper. When external vertical vibration acts on the top plate 1 or the bottom plate 2, the connecting rod assembly 3 can generate shear-type telescopic deformation, converting the vertical linear displacement into the swing angular displacement at the hinge shaft 10, and synchronously driving the inertial coupling joint to generate relative rotation, thereby converting the torsional negative stiffness into vertical negative stiffness, which matches the positive stiffness of the elastic support 4 to achieve quasi-zero stiffness vibration isolation.

[0061] In one embodiment, the operation method of the electro-permanent magnet low-energy-consumption and long-stroke quasi-zero stiffness vibration damper includes the following steps: Step 1: Constructing the initial quasi-zero stiffness equilibrium state This step is the static debugging phase, used to establish the initial working reference point of the vibration damper. The specific process is as follows: 1. Mechanical assembly and positive stiffness pre-adjustment: After the overall mechanical assembly of the shock absorber is completed, the pre-compression of the elastic support 4 is adjusted according to the preset load, so that the elastic support 4 provides stable static load support for the top plate 1 and the load above, while outputting constant positive support stiffness.

[0062] 2. Initial magnetization of the permanent magnet: A pulse current with preset parameters is passed into the excitation coil 11 to magnetize the soft magnetic core 9; after the soft magnetic core 9 is magnetized, it is superimposed with the basic magnetic field of the hard magnetic core 8, and the electromagnetic structure is coupled with the permanent magnet 7 on the ring 5 through the air gap magnetic field to generate initial torsional negative stiffness.

[0063] 3. Quasi-zero stiffness matching calibration: Fine-tune the amplitude and direction of the pulse current, change the magnetization intensity and magnetic pole direction of the soft magnetic core 9, so that the vertical negative stiffness, which is equivalently converted by the torsional negative stiffness through the connecting rod assembly 3, is approximately canceled out by the positive stiffness provided by the elastic support 4 near the equilibrium position, and the total stiffness of the system approaches zero, thus completing the construction of the quasi-zero stiffness initial state.

[0064] 4. Power-off magnetic stability: After the magnetization calibration is completed, the power supply to the excitation coil 11 is directly cut off; the soft magnetic core 9 maintains the current magnetization state for a long time by relying on its own residual magnetism, and can stably maintain the negative stiffness characteristics without continuous energy input.

[0065] Step 2: Full-band dynamic vibration isolation operation When external vertical vibration excitation is applied to the vibration damper, the system achieves broadband vibration isolation through the coordinated action of multiple mechanisms, as follows: 1. Displacement Transmission and Motion Conversion: When external vertical vibration acts on the top plate 1 or the bottom plate 2, the connecting rod assembly 3 undergoes scissor-like expansion and contraction deformation. Each connecting rod swings synchronously around the hinge axis 10, converting the vertical linear displacement into a relative angular displacement at the hinge axis 10. The circular ring 5 and the semi-circular ring 6, which are fixed to the connecting rods on both sides respectively, rotate coaxially relative to each other, causing the permanent magnet 7 and the electromagnetic structure to generate continuous relative rotation angles. The scissor structure of the connecting rod assembly 3 can accommodate a large vertical displacement within a compact axial dimension, adapting to large-amplitude vibration conditions.

[0066] 2. Low-frequency quasi-zero stiffness vibration isolation: When the vibration displacement is near the equilibrium position, the total stiffness of the system approaches zero, and the natural frequency is much lower than the low-frequency excitation frequency. This can effectively avoid the resonance range and significantly attenuate the transmission of low-frequency vibrations, thus achieving efficient low-frequency vibration isolation.

[0067] 3. High-frequency inertial capacitance vibration reduction compensation: The circular ring 5, the semi-circular ring 6 and the permanent magnet 7 and electromagnetic structure on them together constitute the rotational inertial coupling mass, which generates an inertial capacitance effect during relative rotation; under high-frequency vibration, the rotational inertia will hinder the transmission of high-frequency angular displacement, effectively reducing the high-frequency vibration transmission rate, making up for the defect of the deterioration of high-frequency vibration isolation performance of traditional quasi-zero stiffness structures, and realizing wideband stable vibration isolation.

[0068] Step 3: Adaptive stiffness adjustment under low-energy conditions When the operating conditions change (such as changes in load weight or fluctuations in excitation frequency / amplitude), the negative stiffness is dynamically adjusted through pulse-type magnetic modulation to rematch the positive and negative stiffness and maintain the quasi-zero stiffness vibration isolation effect. The specific process is as follows: A pulse current with corresponding parameters is supplied to the excitation coil 11 to change the magnetization degree of the soft magnetic core 9, thereby adjusting the magnitude of the magnetic coupling force between the electromagnetic structure and the permanent magnet 7, and realizing the continuous adjustment of the torsional negative stiffness. After the torsional negative stiffness is equivalently converted into vertical negative stiffness by the connecting rod assembly 3, it is rematched with the positive stiffness under the current working condition to maintain the quasi-zero stiffness vibration isolation state.

[0069] Each stiffness adjustment only requires a short pulse of electrical energy, and the power supply to the excitation coil 11 can be cut off after the adjustment is completed. The soft magnetic core 9 can maintain the adjusted magnetization state stably for a long time by relying on its own residual magnetism, without the need for continuous energy input, thus achieving low-energy self-adaptive operation.

[0070] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0071] 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. An electro-permanent magnet quasi-zero stiffness vibration damper, characterized in that, It includes the main frame and at least one set of inertial coupling joints; The main frame includes a top plate (1), a bottom plate (2), a connecting rod assembly (3), and an elastic support member (4); the connecting rod assembly (3) includes multiple connecting rods and a hinge shaft (10), the inner end of each connecting rod is hinged to the hinge shaft (10), and the outer end of each connecting rod is respectively hinged to the top plate (1) or the bottom plate (2); the elastic support member (4) is disposed between the top plate (1) and the bottom plate (2), and the elastic support member (4) is used to provide positive support stiffness; The inertial coupling joint is coaxially arranged with the hinge shaft (10). The inertial coupling joint includes a circular ring (5) and a semi-circular ring (6) arranged coaxially at intervals. The circular ring (5) is connected to one of the connecting rods and a permanent magnet (7) is provided on the circular ring (5). The semi-circular ring (6) is connected to another set of connecting rods and at least one set of electromagnetic structures is installed on the semi-circular ring (6). Each set of electromagnetic structures includes a hard magnetic core (8), a soft magnetic core (9), and an excitation coil (11). The hard magnetic core (8) and the soft magnetic core (9) are axially connected, and the excitation coil (11) is nested outside the hard magnetic core (8) and the soft magnetic core (9).

2. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, The hinge shaft (10) has two shafts, namely the first hinge shaft (101) and the second hinge shaft (102); the connecting rod assembly (3) includes the first connecting rod (301), the second connecting rod (302), the third connecting rod (303) and the fourth connecting rod (304); the inner ends of the first connecting rod (301) and the second connecting rod (302) are hinged to the first hinge shaft (101) through a miniature bearing (12), and the inner ends of the third connecting rod (303) and the fourth connecting rod (304) are hinged to the second hinge shaft (102) through a miniature bearing (12); the outer ends of the first connecting rod (301) and the fourth connecting rod (304) are hinged to the side of the top plate (1) through a connector (13), and the outer ends of the second connecting rod (302) and the third connecting rod (303) are hinged to the side of the bottom plate (2) through a connector (13).

3. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 2, characterized in that, The miniature bearing (12) is sleeved on the outside of the rod body of the corresponding hinge shaft, and the ends of each connecting rod are respectively fixed to the outer ring of the corresponding miniature bearing (12).

4. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, The permanent magnet (7) is a tile-shaped permanent magnet, which is fixed to the inner wall of the ring (5).

5. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, The magnetization direction of the hard magnetic core (8) is the same as that of the soft magnetic core (9), and the magnetic poles of the hard magnetic core (8) and the soft magnetic core (9) both point to the coaxial center of the circular ring (5) and the semi-circular ring (6).

6. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, Each set of electromagnetic structures also includes a magnetically permeable shell (18), which is fitted over the outside of the excitation coil (11).

7. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 6, characterized in that, The semicircular ring (6) has a cylindrical mounting hole, and the electromagnetic structure is embedded in the cylindrical mounting hole; the bottom of the magnetic permeable shell (18) and the corresponding position of the semicircular ring (6) both have wiring through holes, and the external wire of the excitation coil (11) passes through the wiring through holes.

8. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, Two sets of electromagnetic structures are installed on the semicircular ring (6). The two sets of electromagnetic structures are symmetrically distributed about the central axis of the semicircular ring (6), and the included angle between the axes of the two sets of electromagnetic structures is 90°.

9. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, The main frame also includes a linear guide assembly, which includes a linear bearing (17), a flange (14), and a bearing seat (15); the flange (14) is fixed to the lower surface of the top plate (1), the bearing seat (15) is fixed to the upper surface of the bottom plate (2), and the linear bearing (17) is vertically mounted on the flange (14); the elastic support (4) is a linear spring, which is sleeved on the outside of the linear bearing (17).

10. The electro-permanent magnet quasi-zero stiffness vibration damper according to claim 1, characterized in that, The semicircular ring (6) and the circular ring (5) are arranged coaxially and nested together, and a radial gap is reserved between the semicircular ring (6) and the circular ring (5).

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