CN115325086A - Novel combined vibration damping device with adjustable rigidity and damping - Google Patents

Novel combined vibration damping device with adjustable rigidity and damping Download PDF

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Publication number
CN115325086A
CN115325086A CN202211010307.0A CN202211010307A CN115325086A CN 115325086 A CN115325086 A CN 115325086A CN 202211010307 A CN202211010307 A CN 202211010307A CN 115325086 A CN115325086 A CN 115325086A
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damping
spring
rigidity
vibration
rotor
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郑伟森
廖松泉
段光振
王敏
吴通
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University of Shanghai for Science and Technology
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University of Shanghai for Science and Technology
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F13/00—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F1/00—Springs
    • F16F1/02—Springs made of steel or other material having low internal friction; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
    • F16F1/04—Wound springs
    • F16F1/12—Attachments or mountings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F6/00—Magnetic springs; Fluid magnetic springs, i.e. magnetic spring combined with a fluid
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/72—Wind turbines with rotation axis in wind direction

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  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Vibration Prevention Devices (AREA)

Abstract

The invention discloses a novel combined vibration damping device with adjustable rigidity and damping, and relates to the technical field of vibration damping; the device comprises a reluctance stress negative stiffness spring positioned in a shell and a piezoelectric friction component positioned in a bearing seat; a central shaft is connected between the two, a metal spiral spring is sleeved outside the central shaft, the bottom of the metal spiral spring is connected with a spring base positioned at the top of the shell, and the top of the metal spiral spring is connected with the bottom of the bearing seat; the central shaft is fixedly connected with the top in the shell through a metal cross-shaped sheet spring, the magnetic resistance stress negative stiffness spring and the metal cross-shaped sheet spring can be connected in parallel to realize the adjustment of quasi-zero stiffness, and the piezoelectric friction component can realize the adjustment of damping; and a load platform is fixedly arranged at the top of the bearing seat. The invention has the nonlinear frequency-variable characteristics of high static rigidity-low dynamic rigidity, large low-frequency damping-small high-frequency damping, can well solve the contradiction between the bearing capacity and the vibration damping frequency band and the contradiction between high-frequency vibration attenuation and low-frequency vibration attenuation, and realizes high-performance vibration damping.

Description

Novel combined vibration damping device with adjustable rigidity and damping
Technical Field
The invention relates to the technical field of vibration reduction, in particular to a novel combined vibration reduction device with adjustable rigidity and damping.
Background
In the field of vibration damping, important indexes for measuring the performance of a vibration damping device are a vibration damping frequency band and a vibration attenuation rate. The linear vibration damper used in engineering mainly adopts elastic element and damping element with fixed parameters to complete vibration damping of controlled object. The reduction of the rigidity can reduce the natural frequency of the system and expand the vibration reduction frequency band, but the static deformation is too large, and the bearing capacity is reduced; increasing damping may reduce the formants near the natural frequency, but at the same time, may reduce the high frequency vibration attenuation rate; and once the rigidity and damping parameters of the linear vibration damper are determined, the application range of the linear vibration damper is fixed, so that the linear vibration damper is effective only in a certain frequency range, and the environment adaptability is weak.
With the continuous improvement of processing and measuring precision in modern industry, the traditional vibration damper can not meet the vibration damping requirement in specific occasions, and a novel combined vibration damper with adjustable rigidity and damping is urgently needed to be developed in engineering, so that the combined vibration damper has the nonlinear frequency change characteristics of high static rigidity, low dynamic rigidity, high low frequency damping and small high frequency damping, the contradiction between the bearing capacity and the vibration damping frequency band and the contradiction between high frequency and low frequency vibration damping are solved, and high-performance vibration damping is realized.
Disclosure of Invention
The invention aims to provide a novel combined vibration damping device with adjustable rigidity and damping, which solves the problems in the prior art, has the nonlinear frequency-variable characteristics of high static rigidity, low dynamic rigidity, large low-frequency damping and small high-frequency damping, can well solve the contradiction between bearing capacity and vibration damping frequency band and the contradiction between high-frequency vibration attenuation and low-frequency vibration attenuation, and realizes high-performance vibration damping.
In order to achieve the purpose, the invention provides the following scheme:
the invention provides a novel combined vibration damping device with adjustable rigidity and damping, which comprises a magnetic resistance stress negative rigidity spring positioned in a shell and a piezoelectric friction component positioned in a bearing seat, wherein the magnetic resistance stress negative rigidity spring is arranged in the shell; a central shaft is connected between the reluctance stress negative stiffness spring and the piezoelectric friction component, a metal spiral spring is sleeved outside the central shaft, the bottom of the metal spiral spring is fixedly connected with a spring base positioned at the top of the shell, and the top of the metal spiral spring is connected with the bottom of the bearing seat; the central shaft is fixedly connected with the top in the shell through a metal cross-shaped leaf spring; and a load platform is fixedly arranged at the top of the bearing seat. The invention integrates a vibration reduction technology which realizes zero stiffness adjustment based on the parallel connection of a novel Maxwell magnetic resistance stress negative stiffness spring and a metal cross spring and realizes frequency and variable damping based on a system multi-parameter model and a mechanical wedge-shaped lever type piezoelectric friction component, can realize the purposes of adjusting the stiffness and the damping, reduces the inherent frequency and the peak value of a resonance peak of a system, simultaneously ensures the high attenuation of high-frequency vibration, and realizes the high-performance vibration reduction of a wider working frequency band. The novel Maxwell magnetic resistance stress negative stiffness spring achieves the purpose of generating negative stiffness by using the Maxwell normal magnetic stress generated by the change of the magnetic resistance in the magnetic circuit, and can provide larger negative stiffness under the same volume compared with the traditional method for realizing the negative stiffness characteristic by using the attraction or repulsion of a magnet. The mechanical wedge-shaped lever type piezoelectric friction component adopts a wedge-shaped block pre-tightening mode, and amplifies the micro displacement of the piezoelectric ceramic actuator by using the mechanical lever type stroke amplification mechanism, so that the friction surface of the amplification mechanism is driven to inwards clamp the high-rigidity friction piece, friction damping is brought to a system, and the size of the friction damping can be adjusted by changing the driving voltage of the piezoelectric ceramic actuator. In practical engineering application, the vibration damping device provided by the invention can actively adjust the rigidity parameter and the damping parameter of the vibration damping device according to real-time working conditions, and the optimal vibration damping effect is achieved by reasonably selecting the rigidity parameter and the damping parameter value.
Optionally, the housing includes an upper housing and a lower housing which are fixedly connected, an outer end of the metal cross-shaped leaf spring is mounted on the upper housing through a bolt, and an inner end of the metal cross-shaped leaf spring is fixed on a shaft shoulder of the central shaft through a fastening nut; the spring base is fixedly connected with the top of the upper shell.
Optionally, the reluctance stress negative stiffness spring includes an upper stator, a clamper and a lower stator, which are coaxially arranged in sequence from top to bottom; a plurality of mounting grooves are uniformly formed in the inner side of the clamp holder, permanent magnets are arranged in the mounting grooves, and the radial directions of the polarities of all the permanent magnets are the same; a rotor is coaxially arranged in a cavity formed by the upper stator, the lower stator and the holder, gaps are respectively arranged between the rotor and the upper stator and between the rotor and the permanent magnet in the radial direction; the rotor is fixed on the central shaft through threads. The novel Maxwell magnetic resistance stress negative stiffness spring in the vibration damper provided by the invention achieves the purpose of generating negative stiffness by using the Maxwell normal magnetic stress generated by the change of the magnetic resistance in the magnetic circuit, and has the advantages of high magnetic negative stiffness, small volume and light weight. When the rotor is at the balance position, the air gaps between the rotor and the upper and lower stators are the same, the magnetic resistances in the magnetic circuits are the same, and the acting force is zero; when the rotor deviates from the balance position due to vibration, the air gaps between the rotor and the upper and lower stators are different, so that the magnetic resistances in the upper and lower magnetic circuits are different, different Maxwell normal magnetic stresses are generated on the upper and lower surfaces of the rotor, and the direction of magnetic force generation is the same as the direction of displacement deviation, thereby showing the characteristic of negative rigidity. The magnitude of the normal magnetic stress of the Maxwell is related to key factors such as initial gap, magnetic field intensity, magnetic path magnetic permeability and the like, and the magnitude of the negative stiffness in the device can be conveniently and controllably adjusted by changing the initial gaps between the rotor and the permanent magnet and between the upper stator and the lower stator or changing the permanent magnet into the electromagnetic coil and switching on the electromagnetic coil with controllable current and the like.
Optionally, the piezoelectric friction component comprises a mechanical lever-type stroke amplification mechanism, the mechanical lever-type stroke amplification mechanism comprises a first part and a second part which are symmetrically arranged, and a third part and a fourth part are symmetrically arranged between the first part and the second part; the first part and the second part are connected through a flexible hinge, the extension part between the second part and the third part is connected through a flexible hinge, and the third part and the fourth part are connected through a flexible hinge; the tops of the first part and the second part are fixedly connected with the load platform through bolts; a pre-tightening spring baffle is connected above the first part and the second part through a pre-tightening bolt, the bottom of the pre-tightening spring plate is respectively connected with two wedge blocks through two pre-tightening springs, a piezoelectric ceramic actuator is arranged between the two wedge blocks, and the displacement output end of the piezoelectric ceramic actuator is fixedly connected with the wedge blocks through solid glue; the inner sides of the third part and the fourth part above the extension part are provided with wedge surfaces, and the wedge block is in contact fit with the wedge surfaces of the third part or the fourth part through the wedge surfaces at one end far away from the piezoceramic actuator; and a high-rigidity friction piece is arranged between the third part and the fourth part, the high-rigidity friction piece is positioned below the extension part, and the bottom of the high-rigidity friction piece is connected with the upper end of the central shaft through a threaded hole. The mechanical wedge-shaped lever type piezoelectric friction component in the vibration damper provided by the invention is pre-tightened by adopting a mode of a wedge-shaped block and a pre-tightening spring, and an external electric field is used for controlling a piezoelectric ceramic actuator to generate micro-displacement, and the micro-displacement drives friction surfaces on two sides of the other end to inwards clamp a high-rigidity friction piece through the amplification of a mechanical lever type stroke amplification mechanism; when the system vibrates, the friction force is generated by means of the relative motion between the high-rigidity friction piece and the friction surface of the mechanical lever type stroke amplification mechanism, so that the vibration energy of the system is consumed, and friction damping is provided for the system; by controlling the magnitude of the driving voltage of the piezoelectric ceramic actuator, the active adjustment of the friction damping can be realized.
Optionally, a linear bearing is arranged at the bottom of the bearing seat, and the upper part of the central shaft penetrates through the linear bearing and then is connected with the piezoelectric friction component.
Optionally, a guide plate is fixedly installed in the lower shell through bolts, and the bottom of the central shaft penetrates through the guide plate.
Compared with the prior art, the invention achieves the following technical effects:
the novel combined vibration damping device with adjustable rigidity and damping is applied to the field of vibration damping, and can actively adjust the rigidity parameter and the damping parameter of the vibration damping device according to real-time working conditions to realize high-performance vibration damping. Specifically, the invention has the following technical characteristics:
(1) The novel combined vibration damper with adjustable rigidity and damping provided by the invention combines a vibration damping technology which can realize zero rigidity adjustment based on a novel Maxwell magnetic resistance stress negative rigidity spring and a metal cross spring which are connected in parallel and realize adjustable frequency and variable damping based on a system multi-parameter model and a mechanical wedge-shaped lever type piezoelectric friction component, so that the novel vibration damper with adjustable rigidity and damping is formed, the inherent frequency and the resonance peak value of a system can be reduced, the high attenuation of high-frequency vibration is ensured, and the high-performance vibration damping of a wider working frequency band is realized.
(2) The novel Maxwell reluctance stress negative stiffness spring achieves the purpose of generating negative stiffness by using Maxwell normal magnetic stress generated by the change of the reluctance in the magnetic circuit, and can provide larger negative stiffness under the same volume compared with the traditional method of realizing the negative stiffness characteristic by using the attraction or the repulsion of a magnet. The invention can conveniently and controllably adjust the negative stiffness characteristic of the magnetic negative stiffness spring by changing the initial gap between the rotor and the permanent magnet and the initial gap between the upper stator and the lower stator or changing the permanent magnet into the electromagnetic coil and switching on the controllable current to the electromagnetic coil. The magnetic negative stiffness spring has the advantages of compact structure and large adjustable range and linear range of the magnetic negative stiffness.
(3) The adjustable rigidity characteristic of the vibration damper provided by the invention is realized by connecting the novel Maxwell magnetic resistance stress negative rigidity spring and the metal cross-shaped sheet spring in parallel, the magnetic negative rigidity spring is easy to be unstable, and the stability of the vibration damper can be greatly improved by connecting the magnetic negative rigidity spring and the metal cross-shaped sheet spring in parallel; the metal cross-shaped leaf spring has the characteristics of low axial rigidity and high radial rigidity, and can prevent the radial deviation of the central shaft and ensure the output of the axial negative rigidity of the central shaft.
(4) The mechanical wedge-shaped lever type piezoelectric friction component controls the piezoelectric ceramic actuator to generate micro displacement through an external electric field, the micro displacement drives friction surfaces on two sides of the other end to inwards clamp the high-rigidity friction piece through amplification of the mechanical lever type stroke amplification mechanism, friction damping is further provided for a system, and the size of the friction damping can be actively adjusted by changing the driving voltage of the piezoelectric ceramic actuator. The mechanical wedge-shaped lever type piezoelectric friction component changes a holding and clamping mode from a traditional extension mode to a clamping mode, and amplifies the micro displacement of the piezoelectric ceramic actuator by using the mechanical lever type stroke amplification mechanism, so that the defect of insufficient stroke of the piezoelectric ceramic actuator is overcome.
(5) The mechanical lever type stroke amplification mechanism utilizes the flexible hinge as a connecting point and a fulcrum, the flexible hinge has no stroke gap and frictional wear, and the mechanical lever type stroke amplification mechanism has the advantages of compact structure, difficulty in influence of elastic deformation of parts on frictional force, capability of efficiently transmitting micro displacement, capability of conveniently adjusting the scaling of mechanical displacement/clamping torque by utilizing the size of a force arm and the like.
(6) The transmission of micro-displacement is carried out between the piezoelectric ceramic actuator and the mechanical lever type stroke amplification mechanism in the mechanical wedge-shaped lever type piezoelectric friction assembly through the wedge, the pre-tightening force between the wedge and the mechanical lever type stroke amplification mechanism and between the mechanical lever type stroke amplification mechanism and the high-rigidity friction piece is conveniently regulated and controlled by adjusting the pre-tightening spring between the pre-tightening spring baffle and the wedge, the transmission of micro-displacement of the piezoelectric ceramic actuator is guaranteed, and the wedge structure can effectively avoid clamping looseness caused by abrasion.
(7) Each vibration damping element of the vibration damping device provided by the invention adopts a multi-parameter model arrangement mode, and the adjustable damping and the adjustable rigidity are connected in series through a central shaft and then connected in parallel with the metal spiral spring to jointly form a vibration transmission path of the vibration damping device and support a load platform; the adjustable damping is provided by a mechanical wedge lever type piezoelectric friction component, and the adjustable rigidity is provided by connecting a novel Maxwell magneto-resistive stress negative rigidity spring and a metal cross spring in parallel; the principle model of the vibration damping device is equivalent to that of the traditional two-parameter vibration damping device, and the equivalent damping of the vibration damping device has the characteristic of changing along with frequency, namely the vibration damping device also realizes the effect of frequency-variable damping from the system structure level, so that the damping adjustable range of the vibration damping device can be further improved, and the vibration damping performance is improved.
(8) The vibration damping device provided by the invention realizes the adjustability of rigidity and damping, and in practical application, the vibration damping device can actively adjust the rigidity parameter and the damping parameter of the vibration damping device according to the real-time working condition, and the optimal vibration damping effect is achieved by reasonably selecting the rigidity parameter and the damping parameter value.
(9) The vibration reduction parts of the vibration reduction device provided by the invention adopt a coaxial compact installation mode, take the central shaft as a reference, have small integral installation space and good circumferential symmetry, are easy to integrate into a vibration reduction path, and realize high-performance vibration reduction.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a semi-sectional view of a novel combined damping device with adjustable stiffness and damping;
FIG. 2 is a three-dimensional structure view of a metal cross spring;
FIG. 3 is a three-dimensional structure diagram of a magnetic stress negative stiffness spring;
FIG. 4 is a schematic diagram of a magnetic stress negative stiffness spring;
FIG. 5 is a three-dimensional structure of a mechanical wedge lever type piezoelectric friction assembly;
FIG. 6 is a schematic diagram of a mechanical wedge lever type piezoelectric friction assembly;
FIG. 7 is a schematic view of an equivalent model of the vibration damping device of the present invention;
fig. 8 is a graph comparing the damping effect curves of the conventional damping device and the damping device of the present invention.
Description of reference numerals: 1. a load platform; 2. a bearing seat; 3. a linear bearing; 4. a metal coil spring; 5. a spring base; 6. an upper shell; 7. a lower case; 8. a guide plate; 9. a lower stator; 10. a holder; 11. a permanent magnet; 12. a mover; 13. an upper stator; 14. a metal cross-piece spring; 15. fastening a nut; 16. a central shaft; 17. a mechanical wedge lever type piezoelectric friction component; 17-1, pre-tightening the bolt; 17-2, pre-tightening a spring baffle; 17-3, pre-tightening a spring; 17-4, a piezoceramic actuator; 17-5, wedge blocks; 17-6, flexible hinging; 17-7, a mechanical lever type stroke amplification mechanism; 17-8, high rigidity friction piece.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a novel combined vibration damping device with adjustable rigidity and damping, which solves the problems in the prior art, has the nonlinear frequency-variable characteristics of high static rigidity, low dynamic rigidity, large low-frequency damping and small high-frequency damping, can well solve the contradiction between bearing capacity and vibration damping frequency band and the contradiction between high-frequency vibration attenuation and low-frequency vibration attenuation, and realizes high-performance vibration damping.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
As shown in fig. 1 and 7, the novel combined vibration damping device with adjustable stiffness and damping provided by the invention is formed by combining two parts of adjustable stiffness and adjustable damping according to the arrangement mode of a multi-parameter system model, wherein the adjustable stiffness part is based on a novel Maxwell magneto-resistive stress negative stiffness spring which is connected in parallel with a metal cross plate spring 14 to realize adjustable zero stiffness, and the novel Maxwell magneto-resistive stress negative stiffness spring comprises an upper stator 13, a lower stator 9, a holder 10, a permanent magnet 11 and a rotor 12; the adjustable damping part realizes adjustable frequency and variable damping based on a system multi-parameter model and a mechanical wedge lever type piezoelectric friction component 17; the rest parts comprise a load platform 1, a bearing seat 2, a linear bearing 3, a metal spiral spring 4, a spring base 5, an upper shell 6, a lower shell 7, a guide plate 8, a fastening nut 15 and a central shaft 16 with two parts of adjustable serial rigidity and adjustable damping.
As shown in fig. 1 and 2, a load platform 1 is connected with a bearing seat 2 through a bolt; the lower end of the metal spiral spring 4 is sleeved on the spring base 5 for positioning, and the upper end of the metal spiral spring supports the bearing seat 2 and the load platform 1; the outer end of the metal cross-shaped leaf spring 14 is mounted on the upper shell 6 through a bolt, the inner end of the metal cross-shaped leaf spring is fixed on a shaft shoulder of the central shaft 16 through a fastening nut 15, and the characteristics of high radial rigidity and low axial rigidity of the metal cross-shaped leaf spring 14 can prevent the central shaft 16 from radial deviation and do not influence the output of axial negative rigidity; the guide plate 8 is mounted on the lower shell 7 through bolts, plays a role in guiding the axial movement of the central shaft 16 and prevents the central shaft 16 from radially deviating; the linear bearing 3 is arranged on the bearing seat 2 and also plays a role in guiding and positioning the axial movement of the central shaft 16; the spring base 5 is connected with the upper shell 6 through bolts; the upper shell 6 is connected with the lower shell 7 through bolts, and the novel Maxwell magnetic resistance stress negative stiffness spring inside is compressed and fixed; the whole damping device is coaxially arranged around the central shaft 16, and has a compact structure and good circumferential symmetry.
As shown in fig. 1 and 3, the novel Maxwell reluctance stress negative stiffness spring in the vibration damping device provided by the invention comprises an upper stator 13, a lower stator 9, a clamper 10, a permanent magnet 11 and a mover 12. All the permanent magnets 11 have the same specification, are uniformly distributed and fixed in corresponding grooves of the annular clamp 10, and the polarities of all the permanent magnets 11 are kept in the same radial direction; the clamper 10 is limited and fixed up and down through an upper stator 13 and a lower stator 9 respectively; the rotor 12 is positioned in a cavity formed by the upper stator 13, the lower stator 9 and the clamper 10 and is coaxially arranged, a certain gap is kept between the upper rotor 12 and the upper stator 13 as well as between the upper rotor 12 and the lower stator 9 in the axial direction, and a certain gap is kept between the rotor 12 and the permanent magnet 11 in the radial direction; the whole novel Maxwell magnetic resistance stress negative stiffness spring is positioned in a cavity formed by the upper shell 6 and the lower shell 7, wherein the rotor 12 is fixed on the central shaft 16 through threads and outputs negative stiffness for the system. The novel Maxwell magnetic resistance stress negative stiffness spring achieves the purpose of generating negative stiffness by using Maxwell normal magnetic stress generated by the change of magnetic resistance in a magnetic circuit, and the size of the Maxwell normal magnetic stress is related to key factors such as initial gap, magnetic field intensity and magnetic circuit permeability. Therefore, the invention can conveniently and controllably adjust the magnitude of the negative stiffness in the device by changing the initial gaps between the rotor and the permanent magnet as well as between the upper stator and the lower stator, or changing the permanent magnet into the electromagnetic coil and switching on the electromagnetic coil with controllable current and other means.
As shown in figures 1 and 5, a piezoelectric friction component in the vibration damping device provided by the invention is a mechanical wedge-shaped lever-type piezoelectric friction component 17 which comprises a pre-tightening bolt 17-1, a pre-tightening spring baffle 17-2, a pre-tightening spring 17-3, a piezoelectric ceramic actuator 17-4, a wedge-shaped block 17-5, a mechanical lever-type stroke amplification mechanism 17-7 and a high-rigidity friction piece 17-8. The parts in the mechanical wedge lever type piezoelectric friction component 17 are integrally arranged in a left-right symmetrical mode; the displacement output end of the piezoelectric ceramic actuator 17-4 is fixedly connected with the wedge-shaped block 17-5 through special solid glue; the wedge-shaped block 17-5 is in contact fit with a wedge-shaped surface on the mechanical lever-type stroke amplification mechanism 17-7 through the wedge-shaped surface to transfer micro displacement; the mechanical lever type stroke amplification mechanism 17-7 can be divided into 4 blocks which are connected by three flexible hinges 17-6, the two sides of the flexible hinges are fixed with the load platform 1 through bolts, and the middle two blocks are used as levers to amplify the micro-displacement output by the piezoelectric ceramic actuator 17-4, so as to clamp a high-rigidity friction block 17-8 at the other end; the pre-tightening spring 17-3 is positioned between the pre-tightening spring baffle 17-2 and the wedge block 17-5; the pre-tightening spring baffle 17-2 is connected with two sides of the mechanical lever type stroke amplification mechanism 17-7 through a pre-tightening bolt 17-1, and extrudes the pre-tightening spring 17-3 to pre-tighten the cooperation between the mechanical lever type stroke amplification mechanism 17-7, the wedge block 17-5 and the high-rigidity friction piece 17-8; the high-rigidity friction piece 17-8 is connected with the upper end of the central shaft 16 through a threaded hole, and when the system vibrates, friction force is generated by means of relative movement between the high-rigidity friction piece 17-8 and the mechanical lever type stroke amplification mechanism 17-7, so that vibration energy of the system is consumed, and friction damping is provided for the system; by controlling the magnitude of the driving voltage of the piezoceramic actuator 17-4, active adjustment of the frictional damping can be achieved.
The vibration damping principle of the vibration damping device of the present invention is explained below:
the magnetic negative stiffness vibration damper generally configures a magnet in an attractive or repulsive manner to realize a negative stiffness characteristic, and effectively damp low-frequency vibration. However, the negative stiffness provided by a magnetic negative stiffness mechanism based on the attractive or repulsive forces between magnets is low. For a structure with high static support stiffness, to provide sufficient magnetic negative stiffness to offset the positive stiffness of the structure, the volume or mass of the magnetic negative stiffness mechanism needs to be increased to realize higher negative stiffness, thereby resulting in larger volume and realization difficulty of the vibration damping device. Therefore, the damping device adopts a novel Maxwell magnetic resistance stress negative stiffness spring, and has the advantages of high magnetic negative stiffness, small volume and light weight. Compared with the attractive force or the repulsive force between the magnetic poles, the magnetic negative stiffness spring based on the Maxwell reluctance stress principle has higher force density, compact structure and fast frequency response because the air gap reluctance changes along with the change of the displacement of the rotor.
The Maxwell magneto-resistive stress is a magnetic normal force, the direction of the force is along the normal direction of the air gap, and the magnitude of the force can be expressed as follows:
Figure BDA0003810279250000081
wherein S is the polar area of the air gap, μ 0 For vacuum permeability, B is the magnetic flux density in the air gap, increasing as the length of the air gap decreases.
As shown in fig. 4, the dashed line is a magnetic line, and the total magnetic flux flowing from the permanent magnet 11 to the mover 12 forms two magnetic flux loops in the upper stator 13 and the lower stator 9, respectively. Neglecting the influence of magnetic leakage, the air gap flux density of the upper and lower surfaces of the mover 12 can be calculated according to the gauss law and ampere loop law as follows:
Figure BDA0003810279250000091
Figure BDA0003810279250000092
in the formula, B 1 Is the magnetic flux density in the air gap on the upper surface of the mover, B 2 In an air gap on the lower surface of the moverMagnetic flux density of (1), S 0 Is the polar area of the mover at the air gap, B pm Is the magnetic flux density, S, of the magnet pm Is the equivalent pole area of the magnet, x is the displacement of the mover from the equilibrium position in the axial direction, x 0 Is the initial thickness of the air gap,/ s Is the stator length, μ, in the direction of the magnetic circuit sr Is the relative permeability of the stator interior, /) m Is the length of the mover in the direction of the magnetic circuit, mu mr Is the relative permeability of the inside of the mover,. L g Is the length of the holder in the direction of the magnetic circuit, mu gr Is the relative permeability inside the holder.
Coupled type (1) and (2) taking into account the magnetic flux density B in the air gap 1 And B 2 The magnetic force and the negative stiffness of the novel Maxwell magnetic resistance stress negative stiffness spring are respectively expressed as follows:
Figure BDA0003810279250000093
Figure BDA0003810279250000094
as shown in FIG. 6, the frictional damping of the mechanical wedge lever type piezoelectric friction assembly 17 in the vibration damping device of the present invention can be adjusted by changing the driving voltage of the piezoceramic actuator 17-4. The piezoelectric ceramic actuator has the advantages of small volume, high response speed, large output force, no heat generation and the like. According to the characteristics of the piezoelectric ceramic, the relation between the axial output force and the driving voltage can be obtained as follows:
N＝γ×k A ×n×d 33 ×U (4)
wherein gamma is reciprocal of stroke magnification factor of the mechanical lever type stroke magnification mechanism, k A Is the rigidity of the piezoelectric ceramics, n is the number of the piezoelectric ceramics stacks, d 33 Is the axial piezoelectric strain constant, U is the driving voltage, and N is the axial output force.
The frictional damping has the characteristic of nonlinearity, and the dry damping can be realized by using an equivalent linearization methodFrictional non-viscous damping is equivalent to viscous damping (equivalent principle: equivalent viscous damping is equivalent to non-viscous damping in terms of energy dissipated during one vibration cycle). According to the harmonic balance method, when the relative motion between the friction surfaces is simple harmonic vibration, the energy consumed by the sliding friction force in one vibration cycle is 4 μ d NX, the energy consumed by the equivalent damping force of which is pi C omega X 2 . Therefore, the equivalent viscous damping coefficient between friction surfaces is:
Figure BDA0003810279250000101
in the formula u d The coefficient of sliding friction between the friction contact surfaces, X is the simple harmonic vibration displacement amplitude, omega is the simple harmonic vibration circular frequency, and C is the equivalent viscous damping coefficient of friction damping.
As can be seen from equations (4) and (5), the equivalent damping of the mechanical wedge lever type piezoelectric friction member 17 is linear with the driving voltage of the piezoelectric ceramic actuator 17-4.
As shown in fig. 7, the vibration damping device of the present invention has two vibration transmission paths, which may be referred to as a primary path and a secondary path, respectively; meanwhile, the damping elements in the damping device adopt the arrangement mode of a three-parameter model. The main stage path consists of a metal spiral spring 4 and provides main supporting rigidity K for the system; the secondary path is composed of adjustable damping C and adjustable rigidity K 1 The series connection component plays the role of actively adjusting the rigidity and damping of the system, wherein the adjustable damping C is provided by a mechanical wedge lever type piezoelectric friction component 17, and the adjustable rigidity K is 1 The novel Maxwell reluctance stress negative stiffness spring and the metal cross spring 14 are provided in parallel.
The vibration transfer rate function G of the vibration damping device of the present invention can be derived as follows:
Figure BDA0003810279250000102
in the formula, x 0 For the vibrational displacement of the load platform, x 1 Is the vibration displacement of the base platform, s is RadAnd (5) an operator.
Figure BDA0003810279250000103
Comparing equation (6) with equation (7) for the vibration transfer rate function of the conventional passive vibration damping device as described above, it can be seen that:
Figure BDA0003810279250000111
as can be seen from the formula (8), the equivalent damping of the vibration damping device has the characteristic of changing along with the frequency, namely, the vibration damping device realizes the effect of frequency-variable damping from the system structure level, and the vibration damping performance of the device can be further improved.
FIG. 8 is a vibration transmission rate curve diagram of the novel combined vibration damping device with adjustable rigidity and damping provided by the invention under the conditions of rigidity adjustment, damping adjustment and comprehensive adjustment. As can be seen from the solid curve in fig. 8, the vibration transmissivity of the conventional passive vibration damping device has a high peak value at the resonance peak, and the natural frequency is high. As can be seen from the dot-dash curve in fig. 8, the absolute damping of the system is increased after the damping adjustment is adopted in the vibration damping device of the present invention, the resonance peak of the vibration transfer rate is suppressed, and the high-frequency attenuation rate can be maintained. It can be seen from the dashed curve in fig. 8 that the dynamic stiffness of the system is reduced, the natural frequency of the vibration transfer rate is reduced, and the vibration isolation bandwidth is increased after the stiffness adjustment is adopted in the vibration damping device. As can be seen from the point curve in FIG. 8, the absolute damping of the system is increased after the vibration damping device is comprehensively adjusted, the dynamic stiffness is reduced, the effects of formant suppression and vibration damping bandwidth increase are achieved, and the vibration damping performance of the device is greatly improved.
In the description of the present invention, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (6)

1. The utility model provides a rigidity and novel combination vibration damper of damping adjustable which characterized in that: the device comprises a reluctance stress negative stiffness spring positioned in a shell and a piezoelectric friction component positioned in a bearing seat; a central shaft is connected between the reluctance stress negative stiffness spring and the piezoelectric friction component, a metal spiral spring is sleeved outside the central shaft, the bottom of the metal spiral spring is fixedly connected with a spring base positioned at the top of the shell, and the top of the metal spiral spring is connected with the bottom of the bearing seat; the central shaft is fixedly connected with the top in the shell through a metal cross-shaped sheet spring, the magnetic resistance stress negative stiffness spring and the metal cross-shaped sheet spring can be connected in parallel to realize the adjustment of quasi-zero stiffness, and the piezoelectric friction component can realize the adjustment of damping; and a load platform is fixedly arranged at the top of the bearing seat.
2. The new combined damping device with adjustable stiffness and damping according to claim 1, wherein: the shell comprises an upper shell and a lower shell which are fixedly connected, the outer end of the metal cross-shaped leaf spring is installed on the upper shell through a bolt, and the inner end of the metal cross-shaped leaf spring is fixed on a shaft shoulder of the central shaft through a fastening nut; the spring base is fixedly connected with the top of the upper shell.
3. The new combination damping device with adjustable stiffness and damping as claimed in claim 2, wherein: the magnetic resistance stress negative stiffness spring comprises an upper stator, a clamp and a lower stator which are coaxially arranged from top to bottom in sequence; a plurality of mounting grooves are uniformly formed in the inner side of the holder, permanent magnets are arranged in the mounting grooves, and the radial directions of the polarities of all the permanent magnets are the same; a rotor is coaxially arranged in a cavity formed by the upper stator, the lower stator and the holder, gaps are respectively arranged between the rotor and the upper stator and between the rotor and the permanent magnet in the radial direction; the rotor is fixed on the central shaft through threads; after the rotor deviates from the balance position due to vibration, air gaps between the rotor and the upper stator and between the rotor and the lower stator are different, so that the magnetic resistance in the upper magnetic circuit and the lower magnetic circuit is different, different normal magnetic stresses are generated on the upper surface and the lower surface of the rotor, and the direction generated by magnetic force is the same as the direction of displacement deviation, so that the negative stiffness in the device can be adjusted by changing the initial gaps between the rotor and the permanent magnet, between the rotor and the upper stator and between the rotor and the lower stator.
4. The new combination damping device with adjustable stiffness and damping as claimed in claim 2, wherein: the piezoelectric friction component comprises a mechanical lever type stroke amplification mechanism, the mechanical lever type stroke amplification mechanism comprises a first part and a second part which are symmetrically arranged, and a third part and a fourth part are symmetrically arranged between the first part and the second part; the first part and the second part are connected through a flexible hinge, the extension part between the second part and the third part is connected through a flexible hinge, and the third part and the fourth part are connected through a flexible hinge; the tops of the first part and the second part are fixedly connected with the load platform through bolts; a pre-tightening spring baffle is connected above the first part and the second part through a pre-tightening bolt, the bottom of the pre-tightening spring plate is respectively connected with two wedge blocks through two pre-tightening springs, a piezoelectric ceramic actuator is arranged between the two wedge blocks, and the displacement output end of the piezoelectric ceramic actuator is fixedly connected with the wedge blocks through solid glue; wedge surfaces are arranged on the inner sides, above the extension parts, of the third part and the fourth part, and the wedge block is in contact fit with the wedge surface of the third part or the fourth part through the wedge surface at one end, far away from the piezoelectric ceramic actuator, of the wedge block; a high-rigidity friction piece is arranged between the third part and the fourth part, the high-rigidity friction piece is positioned below the extension part, and the bottom of the high-rigidity friction piece is connected with the upper end of the central shaft through a threaded hole; the friction force generated by the relative motion between the high-rigidity friction piece and the friction surface of the mechanical lever type stroke amplification mechanism can consume the vibration energy generated by the system vibration and provide friction damping for the system; by controlling the magnitude of the driving voltage of the piezoelectric ceramic actuator, the active adjustment of the friction damping can be realized.
5. The new combination damping device with adjustable stiffness and damping as claimed in claim 1, wherein: the piezoelectric friction component is arranged on the bearing seat, and the piezoelectric friction component is arranged on the bearing seat.
6. The new combination damping device with adjustable stiffness and damping as claimed in claim 2, wherein: a guide plate is fixedly installed in the lower shell through bolts, and the bottom of the central shaft penetrates through the guide plate.
CN202211010307.0A 2022-08-23 2022-08-23 Novel combined vibration damping device with adjustable rigidity and damping Pending CN115325086A (en)

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CN202211010307.0A CN115325086A (en) 2022-08-23 2022-08-23 Novel combined vibration damping device with adjustable rigidity and damping

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Application Number Priority Date Filing Date Title
CN202211010307.0A CN115325086A (en) 2022-08-23 2022-08-23 Novel combined vibration damping device with adjustable rigidity and damping

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