456 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 discloses a rigidity-adaptive three-degree-of-freedom low-frequency electromagnetic vibration isolator, and belongs to the technical field of precise vibration isolation. The rigidity-adaptive three-degree-of-freedom low-frequency electromagnetic vibration isolator comprises three sets of low-frequency electromagnetic vibration isolators formed by connecting rigidity-adaptive electromagnetic arrays and spiral springs in parallel. The spiral spring stably supports the load in a passive mode and effectively isolates vibration of middle and high frequency bands; the rigidity self-adaptive electromagnetic array generates high negative rigidity through a moving magnetic array and a fixed magnetic array which are composed of four columns of vertically magnetized equal-cross-section cubic permanent magnets, coil current is adjusted in real time through acceleration feedback, external excitation and load mass changes are responded, the negative rigidity is dynamically adjusted, and the requirement for three-degree-of-freedom near-full-band vibration isolation is met. The vibration isolator has adjustable low dynamic rigidity in the vertical and horizontal rotation freedom degrees, the vibration isolation frequency is low, the frequency band is wide, a super-quiet environment is provided for tip equipment, and the instrument precision is remarkably improved.

The vibration isolation device comprises a top plate and a bottom plate, a first upper connecting rod and a second upper connecting rod are hinged to the lower side of the top plate through first cylindrical pins, and a first lower connecting rod and a second lower connecting rod are hinged to the upper side of the bottom plate through second cylindrical pins. The first lower connecting rod is hinged to the first upper connecting rod through a third cylindrical pin, the second lower connecting rod is hinged to the second upper connecting rod through a third cylindrical pin, the nonlinear vibration isolation effect of high static rigidity and low dynamic rigidity can be achieved, positive rigidity is provided by the torsion spring, negative rigidity is provided by the spiral spring, and vibration isolation is achieved. The spiral spring obtains pre-tightening force by rotating the force adjusting piece, and vertical adjustment in the platform period is achieved.

The invention provides a quasi-zero-stiffness base and an adjustable quasi-zero-stiffness local resonance super-structure vibration isolation device, belongs to the field of environmental vibration reduction and isolation in traffic engineering and civil engineering, and aims at solving the problems that in the prior art, a spring quasi-zero-stiffness structure is complex in installation structure and poor in structural stability. The device comprises a bottom plate, a plurality of first beams with a positive stiffness effect, a plurality of second beams with a negative stiffness effect and a plurality of regular triangular prisms, the first beam, the second beam, the regular triangular prism and the bottom plate are integrally formed, on one hand, it is ensured that all connecting pieces are in rigid connection, the situation that connecting points affect the stability of the structure is avoided, on the other hand, the assembling process can be simpler, and the assembling efficiency is improved.

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 discloses a disc type negative stiffness damper which comprises a base plate, a sliding block is fixedly installed on the base plate, and a rack-shaped sliding rail is horizontally installed on the sliding block in a sliding mode. A large gear and a small gear are rotationally installed on the base plate through a supporting structure, one position of the large gear is externally meshed with the small gear, the other position of the large gear is externally meshed with a rack on the sliding rail, the center of the small gear is fixedly connected with a small gear shaft, and a damper is further fixedly connected to the small gear shaft. A first connecting piece is arranged on the edge of the large gear, a second connecting piece is arranged on the base plate, the first connecting piece is connected with one end of a pretension spring, the other end of the pretension spring is connected with the second connecting piece, and the first connecting piece, the second connecting piece and the pretension spring form a negative stiffness mechanism. The negative stiffness effect is generated by the pre-tensioning spring, and compared with a pre-pressing spring, the pre-tensioning spring cannot be bent; and meanwhile, compared with the magnetic negative stiffness, the magnetic negative stiffness has a larger stroke.

The invention discloses a quasi-zero stiffness vibration double-control device based on metamaterials, and relates to the technical field of vibration isolation and vibration reduction control. The device comprises a vertical vibration isolation structure, a horizontal vibration isolation layer, a middle plate, an upper connecting plate and a lower connecting plate, the vertical vibration isolation structure is connected to the top face of the horizontal vibration isolation layer, and the device is characterized in that the vertical vibration isolation layer is composed of a plurality of quasi-zero-stiffness metamaterial cell elements which are horizontally and evenly distributed, and each quasi-zero-stiffness metamaterial cell element comprises a buckle mechanism and a wave-shaped beam mechanism; the negative stiffness generated in the movement process of the buckle mechanism and the positive stiffness generated in the loading process of the wave-shaped beam mechanism counteract each other, and a quasi-zero stiffness mechanism is formed. According to the quasi-zero-stiffness metamaterial cell element, the initial stiffness of the quasi-zero-stiffness metamaterial cell element can be changed by adjusting the pre-tightening force of the bolts, so that the vertical bearing capacity is changed, different engineering requirements are met, the problem that low-frequency vibration isolation of a traditional vibration isolation device fails is solved, and the quasi-zero-stiffness metamaterial cell element is particularly suitable for meeting the earthquake and vibration dual-protection requirements of rail transit upper cover buildings.

The invention relates to a negative stiffness multiple amplification energy dissipation device which comprises a damper, a first support, a second support and a negative stiffness device, and one end of the first support, one end of the second support, one end of the damper and one end of the negative stiffness device are hinged together; the two columns and the two beams form a rectangular structure, the other end of the damper is connected with a first vertex angle of the rectangular structure, the other end of the first support is connected with a second vertex angle of the rectangular structure, the other end of the second support is connected with one beam, and the other end of the negative stiffness device is connected with the other beam. Compared with the prior art, through the geometrical relationship of the first support, the second support and the damper, deformation of the damper is amplified, and the first amplification effect is achieved; through the negative stiffness effect of the negative stiffness device, the deformation of the damper is amplified to achieve a second amplification effect, and through the traction effect of the negative stiffness device, the deformation of the damper is amplified to achieve a third amplification effect; and the energy dissipation effect is improved.

Disclosed are an intelligent vibration isolator and a control method thereof. The intelligent vibration isolator includes a base, a vibration isolation mechanism disposed inside the base, and a controller; the base includes a bottom plate and a supporting sleeve disposed on the bottom plate; the vibration isolation mechanism includes a load platform, a supporting platform, a magnetorheological elastomer and an electromagnet which are sequentially and coaxially disposed from top to bottom; the vibration isolation mechanism is provided with at least three negative stiffness mechanisms that are uniformly distributed in a circumferential direction of the supporting platform; a strain detection device is disposed on an outer wall of the magnetorheological elastomer; and the controller adjusts and controls a magnitude of current of the electromagnet according to a received strain magnitude to control vertical stiffness of the isolator, and make the intelligent vibration isolator always be in a quasi-zero stiffness state.

The invention belongs to the technical field of mechanical transmission systems, and particularly discloses a method and a system for calculating, regulating and controlling the vibration isolation rate of a rigidity-variable magnetic torsional vibration buffer, and the method comprises the following steps: obtaining a real-time working condition, modeling a single permanent magnet magnetic field by adopting an equivalent magnetic charge method, and calculating the vibration isolation rate of the rigidity-variable magnetic torsional vibration buffer; a magnetic block negative stiffness model and a spring torsion sheet positive stiffness model of the annular Halbach array are constructed, the total coupling stiffness is calculated, the vibration isolation effect of the magnetic torsional vibration buffer is solved, vibration suppression effects and resonance interval distribution under different working conditions are obtained, and based on the vibration isolation effect of the magnetic torsional vibration buffer, the vibration suppression effect of the magnetic torsional vibration buffer is calculated. The gap adjustable mechanism adjusts the rigidity of the spring torsion sheet and the gap of the magnetic ring in real time. By the adoption of the technical scheme, the gap between the inner magnetic ring and the outer magnetic ring is flexibly set according to multi-working-condition requirements, so that applicability and reliability are improved, and low-frequency torsional vibration is effectively restrained while efficient torque transmission is ensured.

The invention discloses an ultrasonic robot tail end zero-rigidity constant-force driver and a control method thereof.The ultrasonic robot tail end zero-rigidity constant-force driver comprises a shell, a negative-rigidity structure, a positive-rigidity structure and a control circuit board, the shell comprises an external main frame, a top cover and a base, the negative-rigidity structure comprises a fixed magnet and a movable magnet set, and the positive-rigidity structure comprises a positive-rigidity structure and a negative-rigidity structure; the fixed magnet is fixedly installed on the base, the movable magnet set is fixedly installed on the top cover, the positive stiffness structure comprises a linear servo motor, a displacement sensor, a linear spring and a spring seat, the movable magnet set and the fixed magnet generate negative stiffness through magnetic field interaction, and the linear spring generates positive stiffness through deformation. And the resultant forces are offset to realize zero-rigidity constant-force output. The control circuit board is installed in the base and electrically connected with the linear servo motor and the displacement sensor. The method is used for solving the problems that in the prior art, scanning efficiency is low, the method is sensitive to measurement errors, and ultrasonic scanning requirements of complex scenes are difficult to meet.

The invention relates to the technical field of structural vibration control, in particular to an adjustable electric damping-negative stiffness dynamic vibration absorber for a flexible shafting. According to the technical scheme, the damping device comprises a support and a rolling bearing, a plurality of first supporting rods used for supporting are arranged outside the rolling bearing, an electric damper used for absorbing vibration is arranged at one end of each first supporting rod, and a second supporting rod used for supporting is arranged on the other side, away from the first supporting rods, of each electric damper. A negative stiffness vibration absorber is arranged at the end, away from the electric damper, of the second supporting rod, and the electric damper comprises an auxiliary circular ring used for bearing loads. Through the arrangement of the adjusting plate, the adjusting bolt, the disc spring, the mass block, the movable magnet, the static magnet and the electric damper, the purposes of vibration absorption and vibration reduction can be achieved at the transcritical rotating speed and the supercritical working rotating speed, and the negative stiffness dynamic vibration absorption frequency and the electric damping suppression modal frequency can be rapidly adjusted according to the change of the operation working condition; and the application range and the universality are improved.

The invention discloses an adjustable rapid constant-force packaging and bonding mechanism, and relates to the technical field of semiconductor packaging. A bonding head body is movably mounted in the mechanism main body along a first linear direction; the two sides, in the second linear direction perpendicular to the first linear direction, of the bonding head body are connected with the mechanism body through a negative stiffness structure and a linear positive stiffness structure respectively. The linear positive stiffness structure is connected with a guide head of the flexible guide mechanism; a sliding table mechanism is mounted on the mechanism main body; a sliding table body of the sliding table mechanism is connected with guide heads on the two sides through a connecting rod mechanism. The connecting rod mechanism is used for converting the displacement of the sliding table body in the first linear direction into the displacement of the guide head in the second linear direction; a thread adjusting part is movably mounted on the mechanism main body; and the thread adjusting piece is used for adjusting the displacement of the bonding head body in the first linear direction by rotating the thread adjusting piece. The mechanism designed by the invention has the function of quickly entering a constant force range, and meanwhile, different constant forces can be adjusted to be output.

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 self-adaptive anti-lifting device based on negative stiffness compensation comprises a friction pendulum shock insulation support and a negative stiffness compensation assembly, the friction pendulum shock insulation support comprises a first seat plate, a spherical crown body and a second seat plate, and the negative stiffness compensation assembly comprises an upper structure connecting plate, a rigid-flexible assembly, a negative stiffness compression spring, a spherical hinge and an inhaul cable. The rigid-flexible assembly comprises a plurality of elastic plates and a plurality of rigid plates, a first groove is formed in the bottom of the rigid-flexible assembly, a spherical hinge and a plurality of negative-stiffness compression springs are arranged in the first groove, the upper end of the spherical hinge is fixedly connected with the groove bottom wall of the first groove, and the lower end of the spherical hinge extends into a second groove in the top of the first seat plate; the lower end of the spherical hinge is rotationally connected with the first base plate, and the multiple inhaul cables surround the rigid-flexible assembly. Dynamic and self-adaptive adjustment of lifting can be achieved, the normal shock insulation function of the structure is not affected while the whole structure is effectively prevented from being lifted, and the safety and stability of the structure under the action of extreme loads are improved.

The invention discloses a quasi-zero stiffness vibration isolator based on coupling of an inerter and a connecting rod and a parameter design method, and belongs to the technical field of vibration isolators. The quasi-zero stiffness vibration isolator comprises a connecting rod structure, a spring assembly, an inerter, a vibration isolation plate and a mounting base, the connecting rod structure comprises four connecting rods with the same length; the spring assembly comprises a connecting spring and two supporting springs; the rod pieces AB, AC, A 'B' and A 'C' are connected through hinge joints; two ends of AA'are connected with the inerter through connecting springs which are horizontally arranged in parallel; two ends of CC'are fixed on the mounting base, and two ends of BB 'are fixedly hinged on the vibration isolation plate; the BC end and the B 'C' end are connected through a vertical supporting spring; the supporting spring provides positive rigidity in the vertical direction, the connecting spring provides negative rigidity, and the inertial container amplifies the equivalent mass of the vibration isolation target through inertia so as to reduce the resonance frequency. The vibration isolator achieves low force transmissibility and displacement transmissibility under low-frequency excitation, and the adaptability and stability of the vibration isolator are enhanced.

The present invention discloses a novel combined vibration damping device with adjustable stiffness and damping, which relates to the technical field of vibration damping; it includes a magneto-resistive stress negative stiffness spring located inside the housing and a piezoelectric friction assembly located inside the bearing seat; a central shaft is connected between the two, and a metal helical spring is sleeved outside the central shaft. The bottom of the metal helical spring is connected to a spring base located at the top of the housing, and the top of the metal helical spring is connected to the bottom of the bearing seat; the central shaft is fixedly connected to the top inside the housing through a metal cross leaf spring. The magneto-resistive stress negative stiffness spring and the metal cross leaf spring can be connected in parallel to achieve the adjustment of quasi-zero stiffness, and the piezoelectric friction assembly can achieve the adjustment of damping; a load platform is fixedly arranged at the top of the bearing seat. The present invention has non-linear frequency-varying characteristics of high static stiffness - low dynamic stiffness, large low-frequency damping - small high-frequency damping, and can well solve the contradiction between the bearing capacity and the vibration damping frequency band, as well as the contradiction between high-frequency and low-frequency vibration attenuation, and achieve high-performance vibration damping.

The invention discloses a self-adaptive bearing weight quasi-zero stiffness vibration isolator and a control method thereof, and relates to the technical field of vibration isolation equipment. The device comprises a base, the tops of the two sides of the inner wall of the base are fixedly connected with horizontal guide rails, the horizontal guide rails are slidably connected with horizontal sliding blocks, the horizontal sliding blocks are fixedly provided with magnetic torsion negative stiffness mechanisms, the output ends of the magnetic torsion negative stiffness mechanisms are fixedly connected with connecting rods, and the other ends of the connecting rods are rotationally connected with a supporting table; the supporting table is located in the center of the base. The quasi-zero stiffness is formed by the negative stiffness of the magnetic torsion negative stiffness mechanism and the positive stiffness of the vertical spring so as to achieve low-frequency vibration isolation of equipment, quasi-zero stiffness matching of the vibration isolator to equipment with different weights can be achieved by adjusting the working length of the vertical spring, the optimal low-frequency vibration isolation effect is achieved, and the low-frequency vibration isolation efficiency is improved. And the non-linear stiffness of the quasi-zero stiffness vibration isolator for equipment with different weights is completely consistent, that is, the vibration isolator has the same dynamic characteristics under the equipment with different weights.

The invention relates to an airborne equipment vibration isolation system mechanical model establishment and optimization design method. According to the mechanical model building method of the airborne equipment vibration isolation system, parameters alpha and beta are introduced into a normalized Bouc-Wen model, and the mechanical characteristics of the steel wire rope vibration isolation system under different load conditions can be effectively described. On the basis of the model, transmissibility curves of a steel wire rope vibration isolation system and a high-static and low-dynamic steel wire rope vibration isolation system under different load conditions are calculated through a fourth-order Runge-Kutta method, the number of steel wire rope vibration isolation assemblies is adjusted, and optimized parameters alpha and beta can be obtained. And adding a force F (x) generated by a negative stiffness device into the normalized Bouc-Wen model under the optimized parameters to obtain the normalized Bouc-Wen model capable of describing the high-static and low-dynamic steel wire rope vibration isolation system. The force F (x) generated by the negative stiffness device is changed to obtain a transmissibility curve of the high-static low-dynamic steel wire rope vibration isolation system under different negative stiffness, and based on the transmissibility curve under different negative stiffness, the optimal negative stiffness can be obtained through optimization.

The invention provides a quasi-zero stiffness vibration isolation device and a track trajectory determination method and system, and relates to the technical field of precise supporting and vibration isolation. By adopting the horizontal telescopic guide rod, the linear spring and the nonlinear track, the sliding end of the telescopic guide rod is propped against the track to slide under the thrust of the linear spring. In the moving process of the mass block, the sliding track of the sliding end is a nonlinear similar parabola. The linear spring is pushed by the track due to the change of the parabola-like track during sliding, and the compression degree of the linear spring is changed, so that the magnitude of the acting force applied to the track by the sliding end is changed. The change of the track changes the direction of the counter-acting force of the track to the sliding end. Based on the synergistic effect of the horizontal telescopic guide rods, the linear springs and the quasi-parabola non-linear orbits, non-linear restoring force is generated through the non-linear shape of the orbits, quasi-zero-stiffness vibration isolation is achieved, negative-stiffness springs are prevented from being adopted, and the structure of the vibration isolation device is simplified in the mode that the orbits with the simple structure are adopted.

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.

The zero-stiffness vibration isolator comprises a carrying platform and a coil base and further comprises a main supporting spring, an upper hollow shaft, a lower hollow shaft, a magnetic negative stiffness mechanism, a cam roller mechanism and a magnetic force controller, the main supporting spring is fixedly installed between the carrying platform and the coil base, the upper hollow shaft is coaxially installed at the bottom of the carrying platform through an M3 connecting screw, and the lower hollow shaft is coaxially installed at the bottom of the coil base through an M3 connecting screw. The lower hollow shaft is coaxially arranged on the lower portion of the lower hollow shaft, the magnetic negative stiffness mechanism is arranged at the bottom of the carrying platform, the cam roller mechanism is arranged on the coil base, and the magnetic force controller is installed on the coil base. The quasi-zero stiffness vibration isolator solves the problems that in the prior art, an existing quasi-zero stiffness vibration isolator is short in vibration isolation interval, small in vibration isolation mass, poor in vibration isolation effect and low in reliability.

The invention discloses an active and passive composite vibration reduction system, and particularly relates to the technical field of vibration reduction equipment, the active and passive composite vibration reduction system comprises a bottom shell, a load platform, a passive vibration reduction device and an active vibration reduction device, and the passive vibration reduction device and the active vibration reduction device are both arranged between the bottom shell and the load platform; the passive damping device comprises a positive stiffness mechanism and a negative stiffness mechanism which are arranged in parallel; the active damping device comprises a controller, a sensor, a piezoelectric actuator and a flat plate type voice coil motor, the sensor is fixed on the load platform, the sensor, the piezoelectric actuator and the flat plate type voice coil motor are all in signal connection with the controller, and the controller processes signals transmitted by the sensor and transmits commands to the piezoelectric actuator and the flat plate type voice coil motor. The method has higher control precision, stronger anti-interference capability and more excellent adaptability and flexibility, the inherent frequency and the formant peak value of the damping device are effectively reduced, the high attenuation of high-frequency vibration is ensured, and broadband vibration attenuation is realized.

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 provides a line spectrum damping device and method based on dynamic anti-resonance, the line spectrum damping device comprises a main mass block, a positive stiffness spring, a base, an inertial element and a self-adjusting element, the upper end and the lower end of the positive stiffness spring are fixed between the main mass block and the base respectively, and the inertial element comprises a lever and an inertial mass block; the lever is movably clamped and positioned through a flexible hinge mechanism fixed on the main mass block and the base, the inertia mass block is fixed at one end of the lever and is connected with the base through a negative stiffness mechanism, the self-adjusting element is fixed on the base, and two fulcrums are arranged at the top end of the self-adjusting element and are respectively contacted with the lever; the lever ratio of the damping device can be adjusted in real time according to the excitation frequency, automatic adjustment of the vibration isolation frequency is achieved, the vibration isolation effect is enhanced, and meanwhile the weight is reduced.

The invention relates to a negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption, and belongs to the technical field of vibration reduction. The negative stiffness adjustable vibration reduction device comprises a base and a bearing platform located above the base and used for bearing equipment to be subjected to vibration reduction, and the bearing platform is connected with the base through a plurality of vibration isolation springs; an elastic damper, a vibrator and a magnetic vibration absorption device are sequentially arranged between the bearing platform and the base from top to bottom in the vertical direction, the periphery of the vibrator is connected with a plurality of adjustable negative stiffness mechanisms which are arranged in a central symmetry mode, and each adjustable negative stiffness mechanism comprises a negative stiffness fine adjustment device and a horizontal elastic element. And the horizontal elastic element is positioned between the negative stiffness fine adjustment device and the vibrator. The displacement change rate during vibration impact can be greatly reduced, and multi-frequency-band vibration reduction is achieved in a small space.

The invention relates to the technical field of track vibration reduction, in particular to a vibration isolation track based on multiple negative stiffness mechanisms, which comprises a floating slab track bed and a railway track arranged on the top surface of the track bed, two symmetrical vertical rigidity variable vibration isolation supports are arranged at the bottom of the floating slab ballast bed; the vertical rigidity variable type vibration isolation support comprises an outer sleeve, an inner sleeve with a clamping opening, a belleville spring, a steel spring and a shaft rod. A motorized negative stiffness hinge mechanism is arranged in the center of the bottom of the ballast bed; the motorized negative stiffness hinge mechanism is formed by hinging a plurality of connecting rod pieces through a plurality of hinge points; elastic buffer assemblies are symmetrically arranged on the side edges of the ballast bed; the elastic buffer assembly is arranged between the ballast bed and the inner wall of the tunnel; and the elastic buffer assembly comprises an inclined pre-bent steel plate, an inclined pre-tensioning steel spring and a horizontal pre-pressing steel spring, so that the whole ballast bed has a relatively large negative stiffness effect, the natural vibration frequency of the whole system is further reduced, and a very obvious vibration isolation effect is provided.

The embodiment of the utility model provides a shock absorber, a vibration isolation device, two device covers and refrigeration equipment, and belongs to the technical field of refrigeration, a first deformation mechanism has positive rigidity, and one end of the first deformation mechanism is installed on a main base. The adjusting blocks are connected with the other end of the first deformation mechanism, the adjusting blocks and the main base are arranged in the first direction, the adjusting blocks are arranged on the two opposite sides of the first deformation mechanism in a striding mode in the second direction, and the second direction and the first direction are arranged in a crossed mode. The auxiliary bases are arranged on the two opposite sides of the main base in the second direction. The second deformation mechanisms have negative stiffness, the auxiliary bases on each side are correspondingly provided with the second deformation mechanisms, and the second deformation mechanisms on each side are rotationally connected with the corresponding auxiliary bases and the corresponding ends of the adjusting blocks correspondingly. According to the shock absorber, the vibration isolation device, the two device covers and the refrigeration equipment, the good vibration isolation effect is achieved in a low-frequency interval, and vibration noise of the two device covers can be reduced.

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 discloses a low-frequency vibration isolator, which belongs to the technical field of vibration isolators, has a quasi-zero stiffness characteristic, and comprises an upper end cover, a lower end cover, a negative stiffness vibration isolation assembly and a positive stiffness vibration isolation assembly, the negative stiffness vibration isolation assembly comprises a first spring vertically arranged in the center area, and the first spring is connected with the upper end cover and the lower end cover and is in an initial stretching state. The positive stiffness vibration isolation assembly comprises vibration isolation units located on the periphery of the first spring and distributed at intervals in the circumferential direction, each vibration isolation unit comprises a deformable connecting rod structure and a second spring in an initial stretching state, the upper end and the lower end of each connecting rod structure are connected with the upper end cover and the lower end cover correspondingly, and each connecting rod structure is provided with a left half part and a right half part which are oppositely arranged; the second spring is fixedly connected between the left half part and the right half part so as to pull the left half part and the right half part to shrink and deform inwards; the low-frequency vibration isolator has the technical effects that the size is small, the bearing capacity is high, the quasi-zero rigidity characteristic is achieved, and the low-frequency vibration isolator can be suitable for high-end manufacturing platform equipment.