Variable rigidity-inertia synergistic low-frequency tuned mass system and vibration absorption method

Abstract

The invention relates to a variable rigidity-inertia synergistic low-frequency tuned mass system and a vibration absorption method. An arc-shaped groove is formed in the upper portion of a recovery unit, a rack is arranged on the arc-shaped groove, a rotating body of an inerter unit is meshed with the rack through a gear set, and a rotating shaft of the rotating body is connected with a rotating shaft of the gear set through a connecting frame; the connecting frame is connected with an upper structure, the recovery unit is connected with the tuning vibration absorption unit, the fixed rack rail is connected with a lower structure, a sliding rail is arranged beside the fixed rack rail, the tuning vibration absorption unit is erected on the sliding rail, a fixing shaft is arranged on the tuning vibration absorption unit, and a rotating body of an inerter flywheel is fixedly connected with a gear. The rotating body and the gear are sleeved on the fixed shaft, the gear is meshed with the fixed rack track, the first permanent magnet is embedded in the rotating body, and the second permanent magnet is arranged in a cavity of the rotating body. Compared with the prior art, multi-section broadening of the tuning frequency band, energy absorption, vibration reduction and low-frequency offset and self-adaptive recovery of the tuning mass system are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering, and relates to a variable stiffness-inertia enhanced low-frequency tuned mass system and a vibration absorption method. Background Art

[0002] Tuned vibration absorption technology is an effective means of structural vibration control. However, the performance improvement of traditional tuned vibration absorption systems depends on the addition of additional tuning mass. The actual engineering installation space and cost issues limit the performance improvement and device application of traditional dynamic vibration absorption technology. In addition, traditional tuned vibration absorption systems usually use stiffness elements such as springs to construct a recovery mechanism, which is difficult to adapt to the permanent residual deformation of the tuned vibration absorption mass caused by friction in the device. Therefore, the development of mass efficiency enhancement methods and self-recovery mechanisms of dynamic tuned vibration absorption systems is of key significance to improving the performance of tuned vibration absorption systems.

[0003] With the rapid development of engineering technology, the vibration problems faced by various engineering structures are becoming increasingly complex and diverse, especially low-frequency vibration, which poses a serious threat to the stability, safety and service life of the structure. Traditional tuned vibration absorption systems often have defects such as limited tuning range and insufficient energy efficiency when dealing with low-frequency vibration. Therefore, exploring new vibration control mechanisms and technical means is of great practical significance.

[0004] Patent CN119122123A discloses a coaxial counter-rotating gear set type inertia-capacitance damping negative stiffness ternary resonance unit and a super foundation, wherein a driving outer cylinder is sleeved on a lead screw, a nut and a driving gear are sleeved on the lead screw, the driving gear is fixedly connected to the nut, the driving gear is meshed with a first counter-rotating gear and a second counter-rotating gear, the second counter-rotating gear is sleeved on a central shaft through a second rotating cylinder and fixedly sleeved on the second rotating cylinder, the first counter-rotating gear is sleeved on a central shaft through a first rotating cylinder and fixedly sleeved on the first rotating cylinder, the first rotating cylinder and the second rotating cylinder are arranged inside and outside, the central shaft is fixedly connected to a base, a first inertia disk is fixedly connected to the first rotating cylinder, a second inertia disk is fixedly connected to the second rotating cylinder, an energized coil is arranged between the first inertia disk and the second inertia disk, the energized coils are arranged in pairs and fixedly connected to the inertia disks. However, this patent utilizes a ternary resonance unit in combination with different forms of resonance mass to form a local resonance unit based on metamaterials. The resonance unit is only connected to a single-port driving outer cylinder, making it difficult to achieve dual / multiple inertial mass efficiency enhancement and inertial energy absorption, which in turn affects the dissipation and absorption efficiency of vibration energy. In addition, the recovery characteristics of the resonance unit are only adjusted by a tuning spring, with relatively few adjustable parameters, and the adjustment of the recovery characteristics is limited, making it difficult to achieve complex nonlinear behaviors. This patent utilizes the negative stiffness of inertial capacitance damping to achieve energy efficiency enhancement effects. The technical path of the energized coil requires additional electrical energy and energy loss to generate a variable magnetic field, and there are problems with device stability and anti-dynamic interference. In addition, the device has multiple nested and rotating components, and requires high processing and installation accuracy for each component. There are problems with poor gear meshing and uneven rotation, which in turn affects the effects of structural stiffness adjustment and vibration energy absorption.

[0005] Patent CN115585221A discloses a rack and pinion tuned mass damping inertia container suitable for a wind turbine tower, which includes a mass block, a rigid spring, an inertia element, an eddy current damping device, a track, and a bracket; the track is connected to the bracket; the mass block can move along the track; the rigid spring is respectively connected to the bracket and the mass block and provides elastic force for the movement of the mass block along the track; the inertia element is respectively connected to the mass block and the bracket and drives the flywheel to rotate through a gear assembly to increase the adjustable inertia range of the tuned mass system; the eddy current damping device is respectively connected to the mass block and the bracket and provides damping force for the movement of the mass block along the track. However, this patent only utilizes the inertial adjustment property of the apparent mass of the inertial capacitor, ignoring the inertial characteristics of the physical mass of the inertial capacitor itself and its objective influence on the design of the device, and is unable to achieve dual / multiple inertial mass synergy and inertial energy absorption; tuned vibration absorption relies on a larger tuning mass, and the motion mode of a large mass tuning system is difficult to be excited, the tunable frequency range is limited, and the low-frequency energy absorption characteristics are restricted; the stiffness adjustment path of this patent only relies on rigid springs, lacks adaptive adjustment of multi-stage variable stiffness, and its recovery characteristics cannot be adjusted after the stiffness is fixed, and cannot meet the needs of adaptive vibration reduction. Summary of the invention

[0006] The purpose of the present invention is to overcome at least one defect of the above-mentioned prior art and to provide a low-frequency tuned mass system and vibration absorption method with variable stiffness-inertia enhancement. The present invention realizes multi-stage widening of the tuning frequency band, low-frequency offset of energy absorption and vibration reduction, and adaptive recovery of the tuned mass system.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] One of the technical solutions of the present invention is to provide a low-frequency tuned mass system with variable stiffness-inertia enhancement, the system comprising an adaptive recovery device and an electromagnetic dynamic vibration absorption device connected up and down,

[0009] The adaptive recovery device comprises an inertia unit and a recovery unit, an arc groove is provided on the upper part of the recovery unit, a rack is provided on the arc groove, the inertia unit comprises a rotating body and a gear set, the rotating body is meshed with the rack through the gear set, the rotating shaft of the rotating body is connected to the rotating shaft of the gear set through a connecting frame, and the connecting frame is connected to the upper structure,

[0010] The electromagnetic dynamic vibration absorbing device includes a tuned vibration absorbing unit, a fixed shaft, an inertia container, a negative stiffness control unit and a fixed rack track, the recovery unit is connected to the tuned vibration absorbing unit, the fixed rack track is connected to the lower structure, a slide rail is arranged beside the fixed rack track, the tuned vibration absorbing unit is mounted on the slide rail, a fixed shaft is arranged on the tuned vibration absorbing unit, the inertia container includes a flywheel, the flywheel includes a rotating body and a gear, the rotating body is fixedly connected to the gear, the rotating body and the gear are sleeved on the fixed shaft, the gear is meshed with the fixed rack track, the negative stiffness control unit includes a first permanent magnet and a second permanent magnet, the first permanent magnet is embedded in the rotating body, and the second permanent magnet is arranged in the cavity of the rotating body.

[0011] As a preferred technical solution, the upper structure and the lower structure adopt rigid supports or beam-slab components.

[0012] Furthermore, the adaptive recovery device also includes a damping unit, a fixed end of the damping unit is vertically fixedly connected to the upper structure, and an output end of the damping unit is vertically fixedly connected to the connecting frame.

[0013] Further, the gear set includes a driving pinion, a driven large gear and a driven pinion, the rotating body of the inertial unit is fixedly connected to the driven pinion, the driven pinion is meshed with the driven large gear, the driven large gear is fixedly connected to the driving pinion, the driving pinion is meshed with the rack, the rotating shafts of the rotating body and the driven pinion are connected to the connecting frame through a rotating bearing, and the rotating shafts of the driven large gear and the driving pinion are connected to the connecting frame through a rotating bearing.

[0014] Furthermore, the recovery unit is fixedly mounted on the tuned vibration absorbing unit and moves horizontally with the tuned vibration absorbing unit. The recovery unit with the arc-shaped rack as the core moves horizontally with the tuned vibration absorbing unit and causes the inertial unit to rotate through gear meshing. The centroid of the inertial unit moves vertically up and down along the axial direction of the damping unit to compress the damping unit.

[0015] Furthermore, the fixed rack rail is fixedly mounted on the lower structure, and a fixed shaft is fixedly mounted on the tuning vibration absorbing unit.

[0016] Further, the inertia container includes a driving flywheel and a driven flywheel, the driving flywheel includes a driving rotor and a driving gear, the driven flywheel includes a driven rotor and a driven gear, the driving rotor is fixedly connected to the driving gear, the driven rotor is fixedly connected to the driven gear, and the driving rotor, the driving gear, the driven rotor and the driven gear are sleeved on the fixed shaft through a rotating bearing.

[0017] Furthermore, a rack is provided on the inner surface of the active rotating body, a cross frame is fixedly installed on the fixed shaft inside the active rotating body, a transmission gear is installed on the cross frame, the active gear is meshed with the fixed rack track, the rack is meshed with the transmission gear, and the transmission gear is meshed with the driven gear.

[0018] Furthermore, the first permanent magnets are symmetrically distributed in pairs and embedded in the active rotating body, with the same magnetic poles in the horizontal direction and opposite magnetic poles in the vertical direction. The second permanent magnet is fixedly installed on the fixed shaft and is in the magnetic field of the first permanent magnet. The magnetic poles at both ends of the second permanent magnet are opposite to the magnetic poles of the first permanent magnet in the same horizontal direction. The negative stiffness control unit with magnetic pole control as the core is used to control the dynamic tuning vibration absorption unit with the inertia container as the core and provide negative stiffness.

[0019] As a preferred technical solution, in the adaptive restoring device, the angle or curvature of the rack of the arc-shaped groove of the restoring unit can be adjusted according to design requirements to achieve adjustment of the stiffness characteristics of the restoring unit.

[0020] As a preferred technical solution, in the electromagnetic power vibration absorption device, the negative stiffness characteristics of the negative stiffness control unit can be adjusted by adjusting the arrangement angle between the magnetic poles, the driving effect of the negative stiffness control unit on the flywheel can be achieved through gears or chains, and the apparent mass adjustment of the inertia coefficient of the inertia container can be achieved through the radius design of the active flywheel, the transmission gear and the driven gear. The transmission gear and the driven flywheel can theoretically be connected in series in multiple groups to achieve multi-stage amplification of the apparent mass, and the multi-stage amplification and efficiency enhancement of the flywheel apparent mass can be in the form of coaxial rotation or non-coaxial rotation.

[0021] Furthermore, in the initial equilibrium position, the second permanent magnet is located on the central axis of the first permanent magnet which is symmetrical in the horizontal direction, and the driving pinion of the gear set is located at the lowest point of the arc-shaped groove.

[0022] One of the technical solutions of the present invention is to provide a low-frequency tuned vibration absorption method with variable stiffness-inertia enhancement, which uses the system to absorb vibration of the main structure, and the method includes the following steps:

[0023] When the system is working, the tuning vibration absorption unit and the fixed rack track produce relative horizontal displacement to achieve the dynamic tuning function;

[0024] The tuning vibration absorbing unit moves horizontally to drive the active flywheel to rotate. At the same time, the flywheel moves horizontally along the fixed shaft fixedly installed on the tuning vibration absorbing unit. The physical mass of the flywheel is used as the tuning mass to achieve efficiency enhancement.

[0025] When the system is in the original equilibrium state, for the electromagnetic dynamic vibration absorbing device with multi-stage variable stiffness, the second permanent magnet is located on the central axis of the first permanent magnet which is symmetrical in the same horizontal direction. At this time, the magnetic field state is in the random equilibrium position. The maintenance (taking into account the influence of secondary factors that will destroy the random equilibrium) and recovery of the random equilibrium position rely on the inertia unit being at the lowest point of the recovery unit.

[0026] When the system is excited by external vibration, the tuned vibration absorbing unit is displaced and the active flywheel rotates. At this time, the magnetic field of the first permanent magnet will also rotate with the active flywheel, and the original balanced magnetic field of the first permanent magnet and the second permanent magnet will be broken. Due to the greater attraction on one side of the asymmetric opposite poles of the first permanent magnet and the second permanent magnet after rotation, negative stiffness characteristics will be generated on the active flywheel, thereby driving the horizontal displacement of the tuned vibration absorbing unit.

[0027] When the rotation angle reaches the state where the magnetic poles of the first permanent magnet and the magnetic poles of the second permanent magnet are opposite to each other, the magnetic field is in a static equilibrium state, that is, the maximum value of the negative stiffness range; the inertia unit climbs a certain height along the arc groove of the recovery unit;

[0028] If the active flywheel rotates at an angle exceeding the maximum value of the negative stiffness range, the static balance of the magnetic field is destroyed, and the first permanent magnet and the second permanent magnet exhibit positive stiffness characteristics due to the different poles on one side attracting and the same poles on the other side repelling, thereby limiting the horizontal displacement of the tuned vibration absorbing unit.

[0029] When the rotation angle reaches the state where the magnetic poles of the first permanent magnet and the magnetic poles of the second permanent magnet are opposite to each other, the magnetic field is in a random equilibrium state, that is, the maximum value of the positive stiffness interval; the inertia unit climbs to the maximum height along the arc groove of the recovery unit;

[0030] The rotation of the active flywheel will also drive the coaxial rotation of the driven flywheel through the transmission gear, realizing the secondary amplification of the flywheel inertia;

[0031] Since the tuned vibration absorption unit is fixedly connected to the arc-shaped rack of the restoring unit, the restoring unit will produce a horizontal displacement relative to the centroid of the inertial capacity unit. At this time, the arc-shaped rack will drive the gear of the inertial capacity unit to rotate. While the inertial capacity unit rotates, its centroid will be raised by the arc-shaped rack, compressing the output end of the damping unit. The two ends of the damping unit produce relative displacement and relative speed, realizing nonlinear damping energy dissipation.

[0032] Based on the unit's own weight, the inertia unit will apply normal pressure to the recovery unit through the arc-shaped rack. The horizontal component of the normal pressure will cause the tuned vibration absorption unit to move horizontally. When the tuned vibration absorption unit moves back to the system equilibrium state from the horizontal maximum displacement position, the positive and negative stiffness ranges of the magnetic field are swapped, preferentially showing the negative stiffness characteristics that promote the recovery of the tuned vibration absorption unit, thereby promoting the tuned vibration absorption unit to return to the initial equilibrium position.

[0033] As a preferred technical solution, during the design process, the gear ratio of the active flywheel and the fixed rack track and the maximum stroke of the damping unit output are designed to limit the maximum horizontal displacement of the tuned vibration absorbing unit to not exceed the maximum value of the positive stiffness range.

[0034] As a preferred technical solution, assuming that the physical mass of the inertia unit is G, the surface equation of the restoration unit is f(x), x represents the horizontal displacement of the tuned vibration absorbing unit relative to the inertia unit, when the system is in the initial equilibrium state, x=0, the inclination angle at any position of the surface is θ, and tanθ=f'(x); when relative displacement occurs, the restoring force exerted by the inertia unit on the restoration unit is F x =G / cosθ×sinθ=Gtanθ=Gf'(x).

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) Dual inertial mass synergy mechanism and inertial energy absorption path. The present invention makes full use of the dual inertial mass and uses the energy storage and release mechanism of the inertial container to adjust the energy distribution of the system. In the traditional damping energy dissipation process, the deformation of the damping unit is relatively limited, and its energy dissipation effect is limited to a certain extent. However, the present invention introduces an inertial container unit in the adaptive recovery device and uses the rotation of the inertial mass to make the adaptive recovery device exhibit negative stiffness characteristics, thereby achieving a local amplification effect on the deformation of the damping unit and dissipating more vibration energy. In a low-frequency vibration environment, the traditional tuned vibration absorption system is often unable to effectively absorb vibration energy due to the high tuning frequency. The present invention introduces an inertial container in the electromagnetic power vibration absorption device to achieve the amplification of the apparent mass of the electromagnetic power vibration absorption device, thereby reducing the tuning vibration absorption frequency. As the system tuning frequency decreases, the system can better match the frequency of the low-frequency vibration source, and the energy absorption capacity of the system in the low-frequency range is greatly improved.

[0037] (2) Adjustable vertical adaptive recovery mechanism of tuned mass system. Traditional tuned vibration absorption system mainly relies on stiffness elements such as springs to achieve recovery characteristics, while the present invention adopts a new recovery mechanism. The adaptive recovery device generates a restoring force with the help of the weight of the inertia unit. When the system is disturbed and displaced, the weight of the inertia unit acts on the gear meshing with the arc-shaped rack, and the tuned vibration absorption unit is driven to return to the equilibrium position through the gear transmission. By changing the angle or curvature of the arc-shaped rack, the motion trajectory and force state of the gear on the arc-shaped rack can be effectively controlled, thereby realizing the flexible adjustment of the stiffness characteristics of the adaptive recovery device. This method of adjusting stiffness based on geometric parameters provides a high degree of flexibility for optimizing the dynamic characteristics of the system, enabling the system to accurately adapt to various complex working conditions and changing vibration environments, greatly expanding the application potential of the system in engineering practice.

[0038] (3) Multi-stage variable stiffness-inertia-enhanced low-frequency tuned mass system. Traditional tuned vibration absorption relies on bulky tuning mass. The motion mode of the large-mass tuned system is difficult to be excited. The negative stiffness mechanism shows superior characteristics, which can enable the system to achieve tuned vibration absorption function in a wider frequency range. The electromagnetic dynamic vibration absorption device realizes the innovation of multi-stage variable stiffness mechanism through the specific arrangement of magnetic poles. The arrangement of magnetic poles is designed so that the electromagnetic dynamic vibration absorption device can generate negative stiffness and provide a certain positive stiffness. When the tuned vibration absorption unit is excited by vibration, The electromagnetic power vibration absorption device preferentially exhibits negative stiffness characteristics, driving the inertial container flywheel to rotate and the tuned vibration absorption unit to translate; when the translational displacement exceeds the negative stiffness range, the electromagnetic power vibration absorption device exhibits positive stiffness characteristics, providing appropriate restoring force and constraint force, effectively limiting the horizontal displacement of the tuned vibration absorption unit, and ensuring the stability and vibration absorption effect of the system; at the same time, an innovative inertial efficiency enhancement implementation form is proposed, that is, the physical mass of the inertial container is used to achieve tuned vibration absorption efficiency enhancement; the physical mass of the inertial container will generate inertial force during the vibration process, thereby increasing the tuning mass and increasing the vibration absorption effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the three-dimensional structure of a low-frequency tuned mass system with variable stiffness-inertia enhancement in an embodiment of the present invention;

[0040] Figure 2 It is a cross-sectional structural schematic diagram of a low-frequency tuned mass system with variable stiffness-inertia enhancement in an embodiment of the present invention;

[0041] Figure 3 Schematic diagram of the mechanism of the negative stiffness interval in an embodiment of the present invention;

[0042] Figure 4 Schematic diagram of the structure of the electromagnetic dynamic vibration absorption device in an embodiment of the present invention.

[0043] Description of the markings in the figure:

[0044] 1—superstructure, 2—damping unit, 3—inertia unit, 4—rotating bearing, 5—restoring unit, 6—tuning vibration absorbing unit, 7—fixed shaft, 8—driving flywheel, 9—driven flywheel, 10—fixed rack track, 11—slide rail, 12—second permanent magnet, 13—first permanent magnet, 14—transmission gear. DETAILED DESCRIPTION

[0045] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are used to describe common objects, which only refer to different instances of the same object, and are not intended to imply that the objects described in this way must adopt a given order, whether in time, space, order or any other way.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Example:

[0049] A low-frequency tuned mass system with variable stiffness-inertia enhancement, such as Figure 1 and Figure 2 As shown, it includes an adaptive recovery device and an electromagnetic dynamic vibration absorption device connected up and down.

[0050] The adaptive recovery device includes an inertia unit 3 and a recovery unit 5. An arc groove is provided on the upper part of the recovery unit 5, and a rack is provided on the arc groove. The inertia unit 3 includes a rotating body and a gear set. The rotating body is meshed with the rack through the gear set. The rotating shaft of the rotating body is connected to the rotating shaft of the gear set through a connecting frame. The connecting frame is connected to the upper structure 1.

[0051] The electromagnetic dynamic vibration absorbing device includes a tuning vibration absorbing unit 6, a fixed shaft 7, an inertia container, a negative stiffness control unit and a fixed rack track 10, the recovery unit 5 is connected to the tuning vibration absorbing unit 6, the fixed rack track 10 is connected to the lower structure, a slide rail 11 is arranged beside the fixed rack track 10, the tuning vibration absorbing unit 6 is mounted on the slide rail 11, a fixed shaft 7 is arranged on the tuning vibration absorbing unit 6, the inertia container includes a flywheel, the flywheel includes a rotating body and a gear, the rotating body is fixedly connected to the gear, the rotating body and the gear are sleeved on the fixed shaft 7, the gear is meshed with the fixed rack track 10, and the negative stiffness control unit includes a first permanent magnet 13 and a second permanent magnet 12, the first permanent magnet 13 is embedded in the rotating body, and the second permanent magnet 12 is arranged in the cavity of the rotating body;

[0052] The upper structure 1 and the lower structure adopt rigid support or beam-slab components. In this embodiment, the upper structure 1 is preferably a rigid support (I-beam), and the lower structure is preferably a beam-slab component (floor slab);

[0053] The adaptive recovery device further comprises a damping unit 2, the fixed end of the damping unit 2 is vertically fixedly connected to the upper structure 1, and the output end is vertically fixedly connected to the connecting frame;

[0054] The gear set includes a driving pinion, a driven large gear and a driven pinion. The rotating body of the inertia unit 3 is fixedly connected to the driven pinion, the driven pinion meshes with the driven large gear, the driven large gear is fixedly connected to the driving pinion, the driving pinion meshes with the rack, the rotating shafts of the rotating body and the driven pinion are connected to the connecting frame through a rotating bearing 4, and the rotating shafts of the driven large gear and the driving pinion are connected to the connecting frame through a rotating bearing 4;

[0055] In this embodiment, the damping unit 2 is a damper, the rotating body of the inertia unit 3 is a turntable, the fixed end of the damping unit 2 is vertically fixedly installed under the upper structure 1, and the output end is vertically downward, a pair of damping units 2 and a connecting frame are installed on the outside of a pair of rotating bodies, a pair of rotating bodies are installed on both sides of a driven small gear, and a pair of driving small gears are installed on both sides of a driven large gear;

[0056] The recovery unit 5 is fixedly mounted on the tuning vibration absorbing unit 6 and can move horizontally with the tuning vibration absorbing unit 6. The recovery unit 5 with the arc-shaped rack as the core moves horizontally with the tuning vibration absorbing unit 6 and causes the inertia unit 3 to rotate through gear meshing. The centroid of the inertia unit 3 moves vertically up and down along the axis direction of the damping unit 2 to compress the damping unit 2.

[0057] In this embodiment, the recovery unit 5 and the tuning vibration absorbing unit 6 are both made of mass blocks, which are made of steel or concrete, preferably made of steel. A pair of recovery units 5 are vertically fixedly installed on both sides of the top of the tuning vibration absorbing unit 6;

[0058] The fixed rack rail 10 is fixedly mounted on the lower structure, and the fixed shaft 7 is fixedly mounted on the tuning vibration absorbing unit 6;

[0059] In this embodiment, the slide rail 11 uses a smooth slide rail to provide vertical support force for the tuning vibration absorbing unit 6 to ensure its horizontal motion state. The smooth contact surface can reduce the friction between the mass block and the slide rail to ensure that the preset phase difference is maintained between the tuning vibration absorbing unit 6 and the fixed rack rail 10. A pair of fixed rack rails 10 are vertically fixedly installed on the lower structure, and the slide rail 11 is horizontally installed between the pair of fixed rack rails 10. A pair of fixed shafts 7 are horizontally fixedly installed on both sides of the tuning vibration absorbing unit 6, and a pair of inertia containers are installed on both sides of the tuning vibration absorbing unit 6.

[0060] like Figure 4 As shown, the inertia container includes a driving flywheel 8 and a driven flywheel 9, the driving flywheel 8 includes a driving rotor and a driving gear, the driven flywheel 9 includes a driven rotor and a driven gear, the driving rotor is fixedly connected to the driving gear, the driven rotor is fixedly connected to the driven gear, the driving gear is meshed with a fixed rack track 10, and the driving rotor, the driving gear, the driven rotor and the driven gear are sleeved on a fixed shaft 7 through a rotating bearing 4;

[0061] In this embodiment, the active rotating body is a rotating drum with one side closed, and the driven rotating body is a rotating disk. A driven rotating body is installed on the unclosed side of the active rotating body. One side of the closed surface of the active rotating body is fixedly connected to the active gear outside the inner cavity, and one side of the driven rotating body is fixedly connected to the driven gear in the inner cavity direction of the active rotating body.

[0062] A rack is provided on the inner surface of the active rotating body, a cross frame is fixedly installed on the fixed shaft 7 in the active rotating body, a transmission gear 14 is installed on the cross frame, the rack meshes with the transmission gear 14, and the transmission gear 14 meshes with the driven gear;

[0063] In this embodiment, a horizontal frame is fixedly installed on the fixed shaft 7 in the inner cavity of the active rotating body, and a pair of transmission gears 14 are horizontally installed on both sides of the horizontal frame, and the pair of transmission gears 14 are horizontally meshed with the driven gears;

[0064] The first permanent magnets 13 are symmetrically distributed in pairs and embedded in the active rotating body, with the same magnetic poles in the horizontal direction and opposite magnetic poles in the vertical direction. The second permanent magnets 12 are fixedly mounted on the fixed shaft 7 and are in the magnetic field of the first permanent magnets 13. The magnetic poles at both ends of the second permanent magnets 12 are opposite to the magnetic poles of the first permanent magnets 13 in the same horizontal direction. The negative stiffness control unit with magnetic pole control as the core is used to control the dynamic tuning vibration absorption unit with the inertia container as the core and provide negative stiffness;

[0065] In this embodiment, four first permanent magnets 13 are symmetrically distributed in pairs and embedded in the active rotating body, two S (N) poles are symmetrically installed on both sides of the vertical axis above the horizontal axis, and two N (S) poles are symmetrically installed on both sides of the vertical axis below the horizontal axis. The second permanent magnet 12 is vertically fixed on the horizontal frame, and the second permanent magnet 12 has an N (S) pole above and an S (N) pole below.

[0066] In the adaptive restoring device, the angle or curvature of the rack of the arc-shaped groove of the restoring unit 5 can be adjusted according to the design requirements to achieve the adjustment of the stiffness characteristics of the restoring unit 5;

[0067] In the electromagnetic dynamic vibration absorption device, the negative stiffness characteristics of the negative stiffness control unit can be adjusted by adjusting the arrangement angle between the magnetic poles. The driving effect of the negative stiffness control unit on the flywheel can be achieved through gears or chains. The apparent mass adjustment of the inertia coefficient of the inertia container can be achieved through the radius design of the active flywheel 8, the transmission gear 14 and the driven gear 9. In theory, multiple groups of transmission gears 14 and driven flywheels 9 can be connected in series to achieve multi-stage amplification of the apparent mass. The multi-stage amplification and efficiency enhancement of the flywheel apparent mass can be achieved in the form of coaxial rotation or non-coaxial rotation.

[0068] A low-frequency tuned vibration absorption method with variable stiffness-inertia enhancement is provided, wherein the above system is used to absorb vibration of the main structure, and the specific steps are as follows:

[0069] When the system is working, the tuning vibration absorbing unit 6 and the fixed rack rail 10 produce relative horizontal displacement to achieve the dynamic tuning function;

[0070] The tuning vibration absorbing unit 6 moves in translation to drive the active flywheel 8 to rotate, and at the same time, the flywheel moves horizontally along the fixed shaft 7 fixedly mounted on the tuning vibration absorbing unit 6, and the physical mass of the flywheel is used as the tuning mass to achieve efficiency enhancement;

[0071] When the system is in the original equilibrium state, for the electromagnetic dynamic vibration absorbing device with multi-stage variable stiffness, the second permanent magnet 12 is located on the central axis of the first permanent magnet 13 which is symmetrical in the same horizontal direction. At this time, the magnetic field state is in the random equilibrium position. The maintenance (taking into account the influence of secondary factors that will destroy the random equilibrium) and recovery of the random equilibrium position rely on the inertia unit 3 being at the lowest point of the recovery unit 5.

[0072] like Figure 3 As shown, when the system is excited by external vibration, assuming that the tuning vibration absorbing unit 6 is displaced to the left, the active flywheel 8 rotates counterclockwise (from the front to the back), the S pole on the upper right of the first permanent magnet 13 approaches the N pole of the second permanent magnet 12, and the S pole on the upper left of the first permanent magnet 13 moves away from the N pole of the second permanent magnet 12, so that the S pole on the upper right shows a greater attraction, thereby showing a negative stiffness characteristic (similarly, the corresponding characteristics of the S pole below the second permanent magnet 12 are the same, and the forces are superimposed);

[0073] When the rotation angle reaches the state where the S pole at the upper right of the first permanent magnet 13 and the N pole of the second permanent magnet 12 are opposite to each other, the magnetic field is in a static equilibrium state, that is, the maximum value of the negative stiffness interval; the inertia unit 3 climbs a certain height along the arc groove of the recovery unit 5;

[0074] If the rotation angle of the first permanent magnet 13 exceeds the maximum value of the negative stiffness interval, the static balance of the magnetic field is destroyed, the S pole at the upper right of the first permanent magnet 13 and the N pole of the second permanent magnet 12 attract each other, and the N pole at the lower right of the first permanent magnet 13 and the N pole of the second permanent magnet 12 repel each other, showing a positive stiffness characteristic of restoring the static balance state of the magnetic field (similarly, the corresponding characteristic of the S pole below the second permanent magnet 12 is the same, and the forces are superimposed);

[0075] When the rotation angle reaches the state where the N pole at the lower right of the first permanent magnet 13 and the N pole of the second permanent magnet 12 are opposite to each other, the magnetic field is in a random equilibrium state, that is, the maximum value of the positive stiffness interval; the inertia unit 3 climbs to the maximum height along the arc groove of the recovery unit 5;

[0076] When the tuning vibration absorbing unit 6 is displaced to the right due to vibration, the magnetic field state and characteristics are similar to the above process;

[0077] The rotation of the active flywheel 8 will also drive the coaxial rotation of the driven flywheel 9 through the transmission gear 14, thus realizing the secondary amplification of the flywheel inertia;

[0078] Since the tuning vibration absorbing unit 6 is fixedly connected to the arc-shaped rack of the restoring unit 5, the restoring unit 5 will produce a horizontal displacement relative to the centroid of the inertial capacity unit 3. At this time, the arc-shaped rack will drive the gear of the inertial capacity unit 3 to rotate. When the inertial capacity unit 3 rotates, its centroid will be raised by the arc-shaped rack, compressing the output end of the damping unit 2. The two ends of the damping unit 2 produce relative displacement and relative speed, realizing nonlinear damping energy dissipation;

[0079] Based on the unit's own weight, the inertia unit 3 applies a normal pressure to the recovery unit 5 through the arc-shaped rack. The horizontal component of the normal pressure will cause the tuned vibration absorbing unit 6 to move horizontally. When the tuned vibration absorbing unit 6 recovers and moves from the horizontal maximum displacement position to the system equilibrium state, the positive and negative stiffness intervals of the magnetic field are swapped, preferentially showing a negative stiffness characteristic that promotes the recovery of the tuned vibration absorbing unit 6, thereby promoting the tuned vibration absorbing unit 6 to return to the initial equilibrium position where the active pinion of the gear set is at the lowest point of the arc-shaped groove.

[0080] During the design process, the gear ratio of the active flywheel 8 and the fixed rack track 10 and the maximum stroke of the output end of the damping unit 2 are designed to limit the horizontal maximum displacement of the tuned vibration absorbing unit 6 to not exceed the maximum value of the positive stiffness interval (i.e., the N pole at the lower right of the first permanent magnet 13 and the N pole of the second permanent magnet 12 are opposite to each other).

[0081] Assume that the physical mass of the inertia unit 3 is G, the surface equation of the restoration unit 5 is f(x), x represents the horizontal displacement of the tuning vibration absorbing unit 6 relative to the inertia unit 3, when the system is in the initial equilibrium state, x = 0, the inclination angle at any position of the surface is θ, and tanθ = f'(x); when relative displacement occurs, the restoring force exerted by the inertia unit 3 on the restoration unit 5 is F x =G / cosθ×sinθ=Gtanθ=Gf'(x).

[0082] The present invention innovates the dual inertial mass enhancement mechanism and inertial energy absorption path, adjusts the energy distribution through the energy storage and release of the inertial container, introduces the inertial container unit 3 to realize the deformation amplification and energy dissipation of the damping unit, and introduces the deadweight of the inertial container and the apparent mass of the inertial container to reduce the tuning vibration absorption frequency, improve the low-frequency energy absorption capacity and expand the application potential. The present invention adopts a new vertical adaptive recovery mechanism, with the help of the deadweight of the inertial container unit 3 and the arc rack and pinion transmission to return to balance, and adjusts the stiffness based on geometric parameters to adapt to complex working conditions and vibration environments. The present invention innovates a multi-stage variable stiffness-inertial enhancement low-frequency tuned mass system, uses the negative stiffness mechanism to broaden the tuning range, and innovates the variable stiffness mechanism of the electromagnetic power vibration absorption device, combined with the physical mass inertial enhancement of the inertial container to ensure the stability of the system and the vibration absorption effect.

[0083] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A low-frequency tuned mass system with variable stiffness-inertia enhancement, characterized in that: The system includes an adaptive recovery device and an electromagnetic dynamic vibration absorption device connected up and down. The adaptive recovery device comprises an inertia unit (3) and a recovery unit (5), the upper part of the recovery unit (5) is provided with an arc-shaped groove, the arc-shaped groove is provided with a rack, the inertia unit (3) comprises a rotating body and a gear set, the rotating body is meshed with the rack through the gear set, the rotating shaft of the rotating body is connected to the rotating shaft of the gear set through a connecting frame, and the connecting frame is connected to the upper structure (1), The electromagnetic dynamic vibration absorbing device comprises a tuning vibration absorbing unit (6), a fixed shaft (7), an inertia container, a negative stiffness control unit and a fixed rack track (10); the recovery unit (5) is connected to the tuning vibration absorbing unit (6); the fixed rack track (10) is connected to a lower structure; a slide rail (11) is arranged beside the fixed rack track (10); the tuning vibration absorbing unit (6) is mounted on the slide rail (11); a fixed shaft (7) is arranged on the tuning vibration absorbing unit (6); the inertia container comprises a flywheel, the flywheel comprises a rotating body and a gear; the rotating body is fixedly connected to the gear; the rotating body and the gear are sleeved on the fixed shaft (7); the gear is meshed with the fixed rack track (10); the negative stiffness control unit comprises a first permanent magnet (13) and a second permanent magnet (12); the first permanent magnet (13) is embedded in the rotating body; and the second permanent magnet (12) is arranged in a cavity of the rotating body.

2. A variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 1, characterized in that: The adaptive recovery device further comprises a damping unit (2), the fixed end of the damping unit (2) being vertically fixedly connected to the upper structure (1), and the output end being vertically fixedly connected to the connecting frame.

3. A variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 1, characterized in that: The gear set comprises a driving pinion, a driven large gear and a driven pinion, the rotating body of the inertial unit (3) is fixedly connected to the driven pinion, the driven pinion meshes with the driven large gear, the driven large gear is fixedly connected to the driving pinion, the driving pinion meshes with the rack, the rotating shafts of the rotating body and the driven pinion are connected to the connecting frame via a rotating bearing (4), and the rotating shafts of the driven large gear and the driving pinion are connected to the connecting frame via a rotating bearing (4).

4. The variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 1, characterized in that: The recovery unit (5) is fixedly mounted on the tuning vibration absorption unit (6).

5. The variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 1, characterized in that: The fixed rack rail (10) is fixedly mounted on the lower structure, and the fixed shaft (7) is fixedly mounted on the tuning vibration absorbing unit (6).

6. The variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 1, characterized in that: The inertia container comprises a driving flywheel (8) and a driven flywheel (9), the driving flywheel (8) comprises a driving rotating body and a driving gear, the driven flywheel (9) comprises a driven rotating body and a driven gear, the driving rotating body is fixedly connected to the driving gear, the driven rotating body is fixedly connected to the driven gear, and the driving rotating body, the driving gear, the driven rotating body and the driven gear are sleeved on a fixed shaft (7) via a rotating bearing (4).

7. A variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 6, characterized in that: A rack is provided on the inner surface of the active rotating body, a cross frame is fixedly mounted on the fixed shaft (7) inside the active rotating body, a transmission gear (14) is mounted on the cross frame, the active gear meshes with the fixed rack track (10), the rack meshes with the transmission gear (14), and the transmission gear (14) meshes with the driven gear.

8. The variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 1, characterized in that: The first permanent magnets (13) are symmetrically distributed in pairs and embedded in the active rotating body, with the same magnetic poles in the horizontal direction and opposite magnetic poles in the vertical direction; the second permanent magnets (12) are fixedly mounted on the fixed shaft (7) and are located in the magnetic field of the first permanent magnets (13); the magnetic poles at both ends of the second permanent magnets (12) are opposite to the magnetic poles of the first permanent magnets (13) in the same horizontal direction.

9. A variable stiffness-inertia enhanced low-frequency tuned mass system according to claim 8, characterized in that: In the initial equilibrium position, the second permanent magnet (12) is located on the central axis of the first permanent magnet (13) which is symmetrical in the horizontal direction, and the driving pinion of the gear set is located at the lowest point of the arc groove.

10. A low-frequency tuning vibration absorption method with variable stiffness-inertia enhancement, characterized in that: The method uses the system according to any one of claims 1 to 9 to absorb vibration of the main structure, and the method comprises the following steps: The tuning vibration absorbing unit (6) and the fixed rack track (10) generate relative horizontal displacement to achieve a dynamic tuning function; The tuning vibration absorbing unit (6) moves in translation to drive the active flywheel (8) to rotate, and at the same time, the flywheel moves horizontally along a fixed shaft (7) fixedly mounted on the tuning vibration absorbing unit (6), and the physical mass of the flywheel is used as a tuning mass to achieve efficiency enhancement; When the system is in an original equilibrium state, the second permanent magnet (12) is located on the central axis of the first permanent magnet (13) which is symmetrical in the same horizontal direction. At this time, the magnetic field state is an arbitrary equilibrium position. The maintenance and recovery of the arbitrary equilibrium position depends on the inertia unit (3) being at the lowest point of the recovery unit (5). When the system is excited by external vibration, the tuning vibration absorption unit (6) is displaced and the active flywheel (8) is rotated. At this time, the magnetic field of the first permanent magnet (13) also rotates with the active flywheel (8), and the original balanced magnetic field of the first permanent magnet (13) and the second permanent magnet (12) is broken. Due to the greater attraction of one side of the asymmetric opposite poles of the first permanent magnet (13) and the second permanent magnet (12) after rotation, a negative stiffness characteristic is generated on the active flywheel (8), thereby driving the horizontal displacement of the tuning vibration absorption unit (6); When the rotation angle reaches a state where the magnetic poles of the first permanent magnet (13) and the magnetic poles of the second permanent magnet (12) are opposite to each other, the magnetic field is in a static equilibrium state, i.e., the maximum value of the negative stiffness range; the inertia unit (3) climbs along the arc-shaped groove of the restoring unit (5); If the rotation angle of the active flywheel (8) exceeds the maximum value of the negative stiffness range, the static balance of the magnetic field is destroyed, and the first permanent magnet (13) and the second permanent magnet (12) exhibit positive stiffness characteristics due to the different poles on one side attracting each other and the same poles on the other side repelling each other, thereby limiting the horizontal displacement of the tuning vibration absorbing unit (6); When the rotation angle reaches a state where the magnetic poles of the first permanent magnet (13) and the magnetic poles of the second permanent magnet (12) are opposite to each other, the magnetic field is in a random equilibrium state, that is, the maximum value of the positive stiffness range; the inertia unit (3) climbs to the maximum height along the arc-shaped groove of the recovery unit (5); The rotation of the active flywheel (8) also drives the coaxial rotation of the driven flywheel (9) through the transmission gear (14), thereby realizing a two-stage amplification of the flywheel inertia; Since the tuning vibration absorption unit (6) is fixedly connected to the arc-shaped rack of the restoring unit (5), the restoring unit (5) generates a horizontal displacement relative to the centroid of the inertial capacity unit (3). At this time, the arc-shaped rack drives the gear of the inertial capacity unit (3) to rotate. When the inertial capacity unit (3) rotates, its centroid is raised by the arc-shaped rack, compressing the output end of the damping unit (2). The two ends of the damping unit (2) generate relative displacement and relative speed, thereby realizing nonlinear damping energy dissipation. The inertia unit (3) applies a normal pressure to the restoration unit (5) through an arc-shaped rack based on the unit's own weight, and the horizontal component of the normal pressure causes the tuning vibration absorption unit (6) to move horizontally. When the tuning vibration absorption unit (6) moves from a horizontal maximum displacement position to a system equilibrium state, the positive and negative stiffness ranges of the magnetic field are swapped, preferentially showing a negative stiffness characteristic that promotes the tuning vibration absorption unit (6) to move back to an initial equilibrium position, thereby promoting the tuning vibration absorption unit (6) to return to an initial equilibrium position.

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