206 results about "Negative stiffness" patented technology

The invention relates to a low-frequency vibration isolator with a wide quasi-zero stiffness interval. The low-frequency vibration isolator comprises a bearing platform, a base, a first negative stiffness assembly, a second negative stiffness assembly and a linear vibration isolation assembly. The bearing platform and the base are arranged in parallel and are both provided with bolt holes and limiting holes; a linear vibration isolation assembly is installed between the bearing platform and the base. The first negative stiffness assemblies are symmetrically distributed with the center point connecting line of the bearing platform and the base as the symmetry axis. The top of the first negative stiffness assembly is connected with the bearing platform, and the bottom of the first negative stiffness assembly is connected with the base. The two ends of the second negative stiffness assembly are connected with the two first negative stiffness assemblies correspondingly. The low-frequency vibration isolator has the characteristics of high static rigidity and low dynamic rigidity, the contradiction between the bearing capacity and the vibration isolation performance of a linear vibration isolation system is effectively solved, and the effective low-frequency vibration isolation effect on a vibration-isolated object is achieved while the bearing capacity of the vibration isolator is guaranteed.

The invention relates to the technical field of structural engineering shock isolation, in particular to a quasi-zero stiffness shock isolation device based on hydraulic negative stiffness and a design method thereof. A quasi-zero stiffness shock isolation device based on hydraulic negative stiffness comprises a vertical bearing unit which comprises at least one vertical spring, and the two ends of the vertical spring are connected to the top face of a lower connecting plate and the bottom face of an upper connecting plate respectively; the negative stiffness unit comprises a hydraulic oil cylinder and a piston rod, the piston rod extends into the hydraulic oil cylinder, and the hydraulic oil cylinder and the piston rod are hinged to the lower connecting plate and the upper connecting plate respectively, or the hydraulic oil cylinder and the piston rod are hinged to the upper connecting plate and the lower connecting plate respectively; the distance between the upper connecting plate and the lower connecting plate is increased or decreased to drive the length of the piston rod extending into the hydraulic oil cylinder to change so as to provide negative stiffness. The problems that in the prior art, when a nonlinear vibration isolation system provides negative stiffness in a metal horizontal spring compensation mode, a quasi-zero stiffness working zone is narrow, the bearing capacity is low, and the requirement for installation precision is high are solved.

The invention provides an electromagnetic quasi-zero stiffness vibration isolator and a control method, and belongs to the technical field of vibration isolation. The vibration isolator comprises a base, a positive stiffness mechanism, a negative stiffness mechanism, a positive and negative stiffness connecting mechanism and a dynamic control module. The positive stiffness mechanism adopts a hydraulic spring to provide basic positive stiffness; the negative stiffness mechanism comprises a plurality of stator units distributed on the base in an annular array and a rotor suspended in the center of a magnetic field of the stator units, and is used for generating nonlinear negative stiffness; the top end of the hydraulic spring supports a load through the bearing table and keeps a preset gap with the inner wall of the rotor; the positive and negative stiffness connecting mechanism realizes displacement transmission and cooperative adjustment; the dynamic control module comprises a displacement sensor and a controller, the sensor collects displacement signals, and the controller adjusts excitation currents of the stator units according to the signals and dynamically adjusts electromagnetic force, so that the vibration isolator is kept in a quasi-zero stiffness state. The quasi-zero stiffness state can be still kept when the load changes, load self-adaption low-frequency vibration isolation is achieved, and the system stability and the vibration isolation performance are improved.

The invention provides an electromagnetic quasi-zero stiffness vibration isolation device and method based on a composite nested structure, and belongs to the technical field of vibration isolation. The device comprises a supporting base, two linear induction motor assemblies symmetrically arranged on the base and provided with a preset gap, and a suspension supporting frame composed of a vertical conductive supporting plate and a horizontal magnetic conductive supporting plate. The vertical conductive supporting plate can float up and down in the gap and forms a positive stiffness module for providing main supporting force and positive stiffness with the motor assembly, and the two eddy current stator pairs are symmetrically distributed on the left side and the right side of the horizontal magnetic conductive supporting plate and form a negative stiffness module for providing negative stiffness with the horizontal magnetic conductive supporting plate; each eddy current stator pair comprises an upper eddy current stator assembly and a lower eddy current stator assembly which are mutually exclusive up and down and float on the upper side and the lower side of the horizontal magnetic conductive supporting plate; the positive and negative stiffness modules are coaxially arranged and cooperate in parallel through a composite nested structure to realize the quasi-zero stiffness characteristic; the rigidity can be dynamically adjusted, and the vibration isolation effect and reliability are improved.

This invention discloses a magnetorheological vibration isolator with negative stiffness characteristics, comprising a magnetorheological elastomer (MRE), an iron sheet, a circular magnet, a cylindrical central shaft, an electromagnetic coil, upper and lower base plates, an outer sleeve, and a bar magnet. The MRE, iron sheet, and circular magnet form a multi-layered MRE structure, with the circular magnet providing a portion of the initial magnetic field to the MRE. The electromagnetic coil, located between the multi-layered MRE structure and the outer sleeve, can control the magnetic field strength acting on the MRE in real time, thereby controlling the stiffness and damping of the MRE isolator. The bar magnet and magnet brackets form a negative stiffness generating unit, respectively installed on both symmetrical sides of the isolator. This invention introduces negative stiffness characteristics into a semi-active vibration isolator, improving the vibration reduction effect of semi-active control to the level of active control, while also offering good stability and low system cost. This invention can be applied to lateral vibration control in high-speed trains, improving stability and safety during high-speed operation, and has broad application prospects.

The invention belongs to the technical field of quasi-zero stiffness vibration isolators, and particularly discloses a self-adaptive adjustment quasi-zero stiffness vibration isolator and a control method. Comprising a base and a bearing plate, and a plurality of positive stiffness units are arranged between the base and the bearing plate to provide basic support; the negative stiffness unit is arranged below the bearing plate, the two ends of the negative stiffness unit are connected with the adjusting structure through the moving unit capable of moving in the length direction of the driving unit, the adjusting structure is composed of a lead screw and an adjusting motor, the projection length of the negative stiffness unit in the horizontal direction can be changed, and therefore continuous adjustment of the negative stiffness is achieved. The vibration isolator is further provided with an acceleration sensor, a relative displacement sensor and a rotary encoder, and the sensors are connected with a processing unit to form a real-time monitoring and feedback control system. The low-frequency vibration isolation device can keep stable low-frequency vibration isolation performance under the condition change, and is suitable for high-precision equipment and complex industrial vibration environments.

The invention belongs to the technical field of vibration isolation, and particularly relates to a quasi-zero stiffness metamaterial sandwich structure, a vibration isolation device and a manufacturing method. The quasi-zero stiffness metamaterial sandwich structure is formed by periodically arranging unit cells in the horizontal direction, and each unit cell comprises an upper panel, a lower panel, a QZS resonator core body and a vertical supporting column; the QZS resonator core comprises a central mass block, QZS resonator units are arranged on the upper portion and the lower portion of the central mass block in a mirroring mode, each QZS resonator unit is composed of two quasi-zero-stiffness unit cells which are arranged in a crossed mode, and each quasi-zero-stiffness unit cell is composed of a negative-stiffness component comprising a horizontal curved beam and a positive-stiffness component comprising an oblique straight beam. According to the sandwich structure, the quasi-zero-stiffness resonator of a novel structure serves as a core body, wider application in the ultra-low frequency vibration reduction field can be achieved, the band gap is adjustable, and the problems that a traditional metal base material structure is high in band gap frequency and limited in application field can be solved.

The shock absorber with the negative stiffness characteristic comprises a cylinder barrel, a piston rod, a piston and a bottom valve, a stretching valve and a one-way valve are arranged on the piston, a compression valve and a one-way valve are arranged on the bottom valve, a valve element of the compression valve is connected to a valve element of the stretching valve through a spring, and a limiting device of the valve element of the stretching valve is arranged on the piston or the piston rod. Damping force values of the compression valve and the stretching valve are both controlled by the stroke of the piston and the acting force of the spring. In the stretching process of the shock absorber, when the spring is in a pressed state, the stretching valve forms damping force, and the shock absorption effect is achieved. The larger the compression stroke (compression force value) of the spring is, the larger the tensile damping value of the shock absorber is. In the compression process of the shock absorber, when the spring is in a pulled state, the compression valve forms damping force, and the shock absorption effect is achieved. The larger the stretching stroke (stretching force value) of the spring is, the larger the compression damping value of the shock absorber is.

Anti-vibration units are provided for vibration suppression in multiple directions. The anti-vibration units may have an X-shaped structure as part of its support structure. The anti-vibration units can work for ultra-low frequency vibration isolation in three directions in a passive manner. The anti-vibration units can achieve a flexible nonlinear stiffness, which contains zero or quasi-zero stiffness, negative stiffness and positive stiffness. A smooth multi-equilibria state is also achievable. Compared with traditional spring-mass-damper (SMD) and typical QZS systems, the provided anti-vibration units can have an enhanced QZS range of larger stroke with guaranteed loading capacity, and can also achieve a lower resonant frequency with a lower resonant peak. At least some embodiments of the anti-vibration units may include a new and innovative arrangement of components that enables a more compact design than typical anti-vibration systems.

A kind of quasi-zero stiffness vibration isolation device based on negative stiffness generated by rotatable leaf spring, quasi-zero stiffness vibration isolation device includes positive stiffness component, negative stiffness component and height adjustment pad;Positive stiffness component, negative stiffness component and height adjustment pad are all installed in outer sleeve, and the bottom surface of positive stiffness component extends from the bottom of outer sleeve, beyond the bottom surface of outer sleeve, forms height difference on level;Negative stiffness component is located above positive stiffness component, and upper end surface extends the upper end surface of outer sleeve, outer sleeve is installed in floating plate, and moves up and down with floating plate together;The negative stiffness component is the negative stiffness component formed by rotatable leaf spring combination, and negative stiffness is generated by the change of rotatable leaf spring.The rotation or movement of rotatable leaf spring negative stiffness component in the process of vibration isolation forms matching negative stiffness, so that good quasi-zero stiffness low-frequency vibration isolation performance is obtained, and the vibration isolation efficiency of floating bed system is improved;It has the characteristics of simple structure, high reliability and long service life.

The invention relates to the technical field of building seismic isolation, in particular to a seismic isolation system with a vertical stepped quasi-zero stiffness characteristic and a design method of the seismic isolation system. A building three-dimensional seismic isolation system with the vertical stepped quasi-zero stiffness characteristic comprises a horizontal seismic isolation support arranged on the top face of a lower buttress; the positive stiffness system comprises at least one vertical steel spring, and the two ends of the vertical steel spring are connected to the top face of the horizontal shock insulation support and the bottom face of the upper buttress correspondingly. The negative stiffness system comprises a variable-slope guide plate, a horizontal multi-layer annular spring and a supporting plate, the thickness of the variable-slope guide plate changes in the height direction of the variable-slope guide plate, one end of the horizontal multi-layer annular spring abuts against the variable-slope guide plate, the horizontal multi-layer annular spring is connected to the supporting plate, and the supporting plate is connected to the upper buttress; the horizontal multi-layer annular spring can be driven to move along the surface of the variable-slope guide plate by changing the distance between the upper buttress and the lower buttress, and the horizontal multi-layer annular spring moves along the surface of the variable-slope guide plate, so that the length of the horizontal multi-layer annular spring is changed, and then negative stiffness is provided.

The invention discloses a low-frequency double-nonlinear quasi-zero-stiffness energy harvesting vibration isolator, and belongs to the technical field of nonlinear vibration control and energy harvesting. Comprising a supporting frame, an upper platform and a lower platform are horizontally installed on the supporting frame, and two vertical optical shafts are symmetrically installed and penetrate through the upper platform and the lower platform; the loading platform is used for bearing a vibration-isolated object and is mounted on the upper platform; the nonlinear negative stiffness structure is a bionic skeleton X-type mechanism arranged between the upper platform and the lower platform and provides negative stiffness restoring force; the non-linear positive stiffness structure is connected with the non-linear negative stiffness structure in parallel and provides restoring force which is non-linearly changed along with displacement; the energy harvesting unit comprises a copper film arranged on the inner side face of the supporting frame and a polytetrafluoroethylene film arranged on the outer side face of the upper platform, and the copper film and the polytetrafluoroethylene film form a friction nanometer generator. The problems that in the prior art, energy harvesting and ultralow-frequency vibration isolation energy harvesting cannot be carried out in a wider working frequency band are solved, and the vibration isolation energy harvesting efficiency can be effectively improved.

The invention relates to a piezoelectric type negative stiffness collaborative vibration absorption supporting rod for a helicopter rotor dynamic load. The piezoelectric type negative stiffness collaborative vibration absorption supporting rod comprises an upper supporting rod body, a lower supporting rod body and a vibration absorption assembly which is arranged between the upper supporting rod body and the lower supporting rod body and used for vibration isolation. The vibration absorption assembly comprises an auxiliary circular ring used for bearing a static load, a lever spring and a disc spring used for providing negative stiffness and adjustable pre-compression are arranged in the auxiliary circular ring, and a mass block used for absorbing and dissipating vibration energy is arranged below the disc spring; the two sides of the lever spring make contact with the piezoelectric ceramic stack, the piezoelectric ceramic stack is connected with the multi-mode external circuit module, the multi-mode piezoelectric shunt damping effect is formed, and meanwhile a plurality of mode components of the system are controlled. When vibration is large, electric energy is stored, and when vibration is small, the mode is switched to a multi-mode RLC circuit dissipation mode, and mechanical vibration energy is converted into electric energy which is consumed through the circuit. Negative stiffness dynamic low-frequency broadband vibration absorption and piezoelectric shunt multi-mode suppression are coupled, and the effect of efficient vibration isolation is achieved.

The invention relates to the technical field of structural engineering, in particular to a stable friction damper with segmented positive and negative stiffness characteristics and a modeling method of the friction damper. The friction damper comprises supports, and a pre-compression spring assembly, a lever assembly, a viscoelastic damper assembly and a rotating friction assembly which are arranged between the supports; the pre-compression spring assembly is used for achieving the negative stiffness effect, the lever assembly plays a role in increasing the force and the negative stiffness effect, and the pre-compression spring assembly and the lever assembly form a stable triangular deformation structure. The rotating friction assembly is used for providing friction damping force and guaranteeing the stability of the structure when the pre-compression spring assembly and the lever assembly rotate relatively. The viscoelastic damper assembly is used for applying vibration reduction control force to the structure when small-amplitude vibration of the structure is not enough to drive the friction surface to slide. The invention further provides a corresponding modeling analysis method, and the dynamic behaviors of the device in different working stages are accurately described.

The application discloses an eddy current negative stiffness magneto-rheological elastomer vibration isolator, which comprises an eddy current damping structure and a negative stiffness magneto-rheological elastomer structure, wherein the eddy current damping structure comprises a U-shaped permanent magnet and a conductor, and the U-shaped permanent magnet and the conductor are annular; the bottom of the U-shaped permanent magnet is mounted on a bottom plate; the top of the conductor is connected with a top plate, and the bottom of the conductor is mounted in the U-shaped permanent magnet to move in a cutting magnetic induction line mode; the bottom plate and the top plate are respectively mounted on a vibration source and a vibration-isolated structure; one end of the negative stiffness magneto-rheological elastomer structure is arranged in an annular inner ring of the U-shaped permanent magnet and connected with the bottom plate; and the other end of the negative stiffness magneto-rheological elastomer structure is arranged in an annular inner ring of the conductor and connected with the top plate. The application can reduce the amplitude of the vibration isolation system when passing through a resonance region, improve the relative vibration isolation effect, and prevent the vibration isolation system structure from being adversely affected due to resonance.

The invention discloses a flexible manipulator with variable clamping force and constant-force rubbing and a using method thereof, and belongs to the technical field of micromanipulators, the flexible manipulator comprises a first driving mechanism, a second driving mechanism, a variable-rigidity clamping mechanism and a constant-force rubbing mechanism, the variable-rigidity clamping mechanism is formed by connecting a guide beam assembly, a variable-rigidity beam assembly and a decoupling beam assembly in series, and the constant-force rubbing mechanism is connected with the first driving mechanism. A first clamping end is arranged at the tail end, the rigidity of the constant force rubbing mechanism can be adjusted through embedded shape memory alloy, the constant force rubbing mechanism is composed of a positive rigidity structure and a negative rigidity structure, a second clamping end opposite to the first clamping end is arranged at the tail end, and the two mechanisms are connected through the decoupling beam assembly to achieve structural decoupling. The problems that an existing flexible manipulator is non-adjustable in clamping rigidity, slow in constant force response and mutual in function interference are solved, and self-adaptive grabbing and stable rubbing of micro-scale objects are achieved.

The present application provides a kind of transmission conductor negative stiffness damper, provides damping by another connection damper, negative stiffness device increases damping ratio, realizes conductor model damping effect;Main components are arranged side by side by fixed magnet and movable magnet, the interaction force between its magnets is basically linear increase, that is, it can guarantee constant negative stiffness value, damping effect is obvious and model loss is small, and durability is strong;Light weight, convenient transportation, easy to install and maintain;Transmission conductor negative stiffness damper is rigidly connected with insulator string as a whole, and can effectively transmit the vibration of conductor galloping;The present application is novel and unique in design, has wide range of application, and has good popularization and application value and economic benefits.

The invention discloses a quasi-zero stiffness sound array vibration isolation device for an unmanned aerial vehicle. The quasi-zero stiffness sound array vibration isolation device comprises a positive stiffness component and a negative stiffness component. The positive stiffness component is a steel spring, the upper end is connected with the unmanned aerial vehicle connecting piece, and the lower end is connected with the negative stiffness component; the negative stiffness component comprises a cylindrical permanent magnet and an annular permanent magnet, the cylindrical permanent magnet is located in an annular space of the annular permanent magnet after the acoustic array is mounted, and the cylindrical permanent magnet and the annular permanent magnet are in a mutual exclusion state; the steel spring, the cylindrical permanent magnet and the annular permanent magnet jointly form a quasi-zero-stiffness structure, and the quasi-zero-stiffness structure is located at a static balance position under the gravity effect of the sound array and stores elastic potential energy. When the unmanned aerial vehicle is disturbed by vibration transmitted by the unmanned aerial vehicle, the negative stiffness component releases elastic potential energy and generates acting force opposite to the disturbance direction so as to counteract vibration transmission. The device has the advantages of simple structure, suppression of vibration of the unmanned aerial vehicle and transmission of aerodynamic noise to a sound array, and the like.

A constant force mechanism comprises a rack, a moving part, an output part, a positive stiffness structure and a negative stiffness structure, and the moving part is movably arranged on the rack; the output part is movably arranged on the rack, and the output part is movably connected with the moving part and drives the moving part to move, so that the output part and the moving part get close to each other or get away from each other; the positive stiffness structure comprises a first curved beam and a second curved beam which are connected between the rack and the moving part, and the first curved beam and the second curved beam are arranged in a crossed mode. The negative stiffness structure comprises a first permanent magnet and a second permanent magnet, the first permanent magnet is arranged on the rack, the second permanent magnet is arranged on the side, away from the positive stiffness structure, of the moving part, and the S pole of the second permanent magnet is opposite to the N pole of the first permanent magnet, or the N pole of the second permanent magnet is opposite to the S pole of the first permanent magnet. According to the constant force output device, the elastic deformation force of the positive stiffness structure and the magnetic force of the negative stiffness structure are overlapped, so that the resultant force is kept constant within a certain displacement range, and constant force output is achieved.

The application discloses an inertial amplification quasi-zero stiffness vibration isolator, which comprises a top plate, a bottom plate, an inertial amplification mechanism and a quasi-zero stiffness mechanism; the inertial amplification mechanism comprises a plurality of first unit mechanisms and a plurality of second unit mechanisms, and the first unit mechanisms and the second unit mechanisms are arranged alternately; two adjacent first sliding blocks are connected through a first tension spring, and two adjacent second sliding blocks are connected through a second tension spring; the quasi-zero stiffness mechanism comprises a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism is connected with the top plate and the bottom plate at two ends respectively, and all the tension springs and the sliding blocks jointly form the negative stiffness mechanism. In the quasi-zero stiffness vibration isolator, the positive stiffness is provided by compression springs, which can provide the required bearing capacity of the overall mechanism in the vertical direction; the negative stiffness is generated when the tension spring device is stretched and deformed along with the displacement movement of the sliding block; after the negative stiffness and the positive stiffness are connected in parallel, the quasi-zero stiffness effect can be achieved, and then the vibration isolation in the vertical direction of the driver's seat in the high-speed running vehicle in the ultra-low and ultra-wide frequency domain can be realized.

This invention provides an electromagnetic quasi-zero stiffness vibration isolation device with adjustable stiffness. It utilizes an electromagnetic coil to provide variable nonlinear negative stiffness, achieving quasi-zero stiffness characteristics. The invention includes a lower housing of a support, a lower end cover, a lower coil, a lower annular permanent magnet, a top block, an upper coil, an upper housing of the support, an upper end cover, a guide rod, an upper outer spring, an upper housing of the permanent magnet, an upper inner spring, an upper permanent magnet, an intermediate permanent magnet, a lower housing of the permanent magnet, a lower inner spring, and a lower outer spring. The permanent magnet and the electromagnetic coil provide variable nonlinear negative stiffness, achieving variable quasi-zero stiffness characteristics. This invention is particularly suitable for applications requiring isolation of wide-frequency excitations, including low-frequency ones.

A space cam type multi-stage quasi-zero stiffness ultra-low frequency vibration isolator capable of capturing high-entropy energy belongs to the technical field of vibration isolation and vibration energy capture. The problem that traditional quasi-zero stiffness vibration isolation devices are difficult to adapt to multi-stage vibration isolation load due to structural limitations is solved, and sensor self-power supply and intelligent detection are realized. The bottom of the positive stiffness spring and guide beam assembly is connected to the base through a bolt and nut, the sliding end is connected to the load platform through a bolt and nut, four groups of negative stiffness piezoelectric beam assemblies are installed on the support in clockwise order, the vertical guide rail of each negative stiffness piezoelectric beam assembly is connected to the load platform through a bolt and nut, four moving cam sliding grooves are connected to the load platform through a bolt and nut in clockwise order, and the deep groove ball bearing in the negative stiffness piezoelectric beam assembly slides into the corresponding cam sliding groove to form a cam pair. The present application can realize multi-stage load quality vibration isolation and sensor self-power supply, and has the advantages of novel structure, low frequency vibration isolation, wide frequency energy capture and flexible design.

A self-leveling six-degree-of-freedom quasi-zero stiffness vibration isolation platform, comprising a base platform, a working platform and a plurality of leg mechanisms with quasi-zero stiffness characteristics arranged therebetween, wherein: the two ends of the leg mechanism are connected through a universal joint between the base platform and the working platform to realize spatial six-degree-of-freedom wide-band vibration isolation. The present application uses a nonlinear gradually hard positive stiffness structure to modulate a negative stiffness structure to design a passive quasi-zero stiffness structure and an active quasi-zero stiffness structure. The rated load of the active quasi-zero stiffness vibration isolation structure is proportional to the current size. The passive quasi-zero stiffness structure and the active quasi-zero stiffness structure are combined. By adjusting the rated load of the active quasi-zero stiffness structure, the self-leveling function of the vibration isolation platform under different loads is realized. The passive quasi-zero stiffness structure is beneficial to provide the carrying capacity and reliability of the vibration isolation platform. Compared with the existing six-degree-of-freedom quasi-zero stiffness vibration isolation platform, the present application has a large carrying capacity, high reliability, is not sensitive to the vibration isolation load, and can realize the self-leveling of the working platform under different loads, which not only ensures the excellent low-frequency vibration isolation performance of itself, but also ensures that the vibration isolation object can work normally.

The invention provides a quasi-zero stiffness horizontal vibration isolator based on a flexible component, and relates to the field of vibration isolation devices. Comprising a base; the motion platform is positioned above the base; the multiple damping units are distributed between the base and the motion platform in the circumferential direction. Each damping unit comprises a spiral flexible sheet and at least two rigid connecting columns; the spiral flexible sheet is of a spiral structure formed by rotation of an elastic sheet and is a positive stiffness unit; wherein one rigid connecting column is connected between the inner end of the spiral flexible sheet and the base, and the other rigid connecting column is connected between the outer end of the spiral flexible sheet and the motion platform. The pre-pressing spring is connected between the base and the motion platform, located in a space defined by the multiple damping units and is a negative stiffness unit. According to the invention, the sensitivity to weight change can be reduced while the overall vertical height is reduced, so that the horizontal vibration transmission between an object and the base is effectively reduced.

This invention discloses an integrated active and passive magnetic negative stiffness mechanism, belonging to the field of precision vibration reduction. It includes a permanent magnet section and an electromagnetic section, providing passive and active negative stiffness respectively. Connected in parallel with a positive stiffness spring, it integrates passive and active vibration isolation. Specifically, it includes a stator permanent magnet, a mover permanent magnet, a stator frame, a mover frame, and a coil assembly. The stator and mover permanent magnets form the permanent magnet assembly, and a coil assembly is added within the permanent magnet assembly. By changing the coil current, the electromagnetic force experienced by the energized coil in the magnetic field is controlled, allowing it to provide different magnitudes of electromagnetic force at different working positions. This compensates for the magnetic force in the working direction, thereby achieving active adjustment and control of the mechanism's negative stiffness. This invention has a relatively compact structure, achieving high linearity and a wide linear range of stiffness characteristics. It also allows for customized stiffness characteristics to meet high-performance vibration reduction requirements in various situations.

The application is a kind of magnetic rheological damping flexible constant force polishing and vibration suppression mechanism, comprising: passive flexible component, fixed plate flange, quick connector, coil, insulating sheet, rubber cover plate, polishing head. Wherein the passive flexible component comprises: inner shell, outer shell, positive stiffness characteristic mechanism, negative stiffness characteristic mechanism, grid plate, the application is installed at the end of industrial robot to realize flexible polishing work, based on the characteristics of positive and negative stiffness characteristic mechanism to realize constant force polishing under certain position deviation, by changing the current size in the coil and then changing the viscosity of magnetic rheological fluid, and then changing the size of damping force, suppressing vibration and reducing force fluctuation, controlling the polishing force in the desired range, improving the stability of polishing force, not only ensuring to prevent workpiece, end effector and polishing environment from being damaged, but also improving the surface polishing quality of workpiece and improving production efficiency.

The invention discloses a quasi-zero stiffness active-passive vibration isolation platform based on a force amplification mechanism. The quasi-zero stiffness active-passive vibration isolation platform is achieved through the synergistic effect of a negative stiffness mechanism, the force amplification mechanism and a frameless torque motor. The negative stiffness mechanism is of a nested double-ring structure, an outer ring stator is composed of arc-shaped permanent magnets magnetized in the radial direction, an inner ring rotor is composed of a fixing sleeve and arc-shaped permanent magnets with alternate magnetic poles, and the permanent magnets are arranged in a magnetic pole alternate mode in the circumferential direction of the inner side. Radial repulsive force is generated through homopolar opposite layout of the permanent magnets, and magnetic negative stiffness is formed. The rotor transmits rotation torque to the force amplification mechanism, the torque is converted into amplified axial force to be output through a geometrical relationship, traditional size limitation is broken through, and mechanical gain is achieved. The axial force and the acting force of the positive stiffness spring are reversely superposed, so that quasi-zero stiffness passive vibration isolation is realized; the tail end of the transmission shaft is connected with a frameless torque motor to form an active control unit, compensation torque is dynamically output through real-time vibration feedback, and finally wide-frequency-domain and high-precision vibration isolation is achieved.

This invention discloses an optimized design method for a vibration isolation platform based on quasi-zero stiffness. The optimized design object is a prismatic vibration isolation platform, comprising a top plate, a bottom plate, a two-layer prismatic structure consisting of a rotating rod connected by bearings, a horizontal spring and a damper installed in the middle of the prismatic structure, and oblique springs installed within the prismatic structural units. The combination of the negative stiffness of the horizontal spring and the positive stiffness of the oblique spring forms the QZS effect. By comparing and analyzing parameters such as the combined stiffness of the horizontal and oblique springs, the rod length of the PIP, and the initial rotation angle, optimized parameters are selected to achieve the optimized design of the vibration isolation platform. This invention enables the prismatic vibration isolation platform to achieve a quasi-zero stiffness effect over a wider range and maintains stable performance under large vibration displacements. It helps to eliminate potential instabilities, bifurcation, and jumping phenomena under large vibration displacements, thereby improving the overall vibration isolation performance.

The application belongs to the field of ultra-precision damping, and specifically discloses a Halbach magnetic negative stiffness mechanism with high negative stiffness, which comprises a support frame, a stator permanent magnet assembly, a mover permanent magnet assembly, a spacing adjusting assembly and a linear guide assembly, and the stator permanent magnet assembly and the mover permanent magnet assembly are both Halbach array structures; the stator permanent magnet assembly comprises a first stator permanent magnet group and a second stator permanent magnet group, the first stator permanent magnet group and the second stator permanent magnet group are symmetrically arranged on the support frame, and the first stator permanent magnet group, the second stator permanent magnet group and the mover permanent magnet assembly are parallel to each other; the spacing adjusting assembly is arranged on the support frame to drive the first stator permanent magnet group and the second stator permanent magnet group to move closer to each other or farther away from each other. Through the structural design of the magnetic negative stiffness mechanism, a greater negative stiffness value can be generated in the same space, and the spacing adjusting assembly can be used to adjust the negative stiffness value of the magnetic negative stiffness mechanism, so that the applicability is better.

This invention discloses a two-dimensional quasi-zero stiffness swing mechanism, belonging to the field of optical-mechanical structure design. It includes a base, an upper plate, a reflector, a flexible hinge, a magnetic negative stiffness mechanism, a linear motor, and a displacement sensor. The lower end of the flexible hinge is fixed to the base, and its upper end is fixed to the upper plate. A reflector is fixed to the upper end of the upper plate, and the reflector's rotation angle can be changed by rotating the flexible hinge. The magnetic negative stiffness mechanism includes an upper permanent magnet holder, a permanent magnet sleeve, a permanent magnet, a screw, and a lower permanent magnet holder; the two permanent magnets have the same magnetic poles on their opposing surfaces. The linear motor includes a stator and a mover; the stator is fixed to the base, and the mover is fixed to the upper plate. The displacement sensor includes a displacement sensor probe and a sensor holder, both of which are fixed to the upper plate. The magnetic negative stiffness mechanism and the positive stiffness flexible hinge are connected in parallel to form a quasi-zero stiffness system, reducing the minimum vibration isolation frequency and improving the system's low-frequency vibration isolation capability.