Patents
Literature
Eureka-AI is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Eureka AI

575 results about "Low frequency vibration" patented technology

Parallel mechanism based multidimensional vibration platform

ActiveCN104154170AAchieving Nonlinear StiffnessSolve the problem of isolating low frequencySpringsShock absorbersEngineeringUltra low frequency
The invention discloses a parallel mechanism based multidimensional vibration platform. Standard zero stiffness of a vibration isolation platform at the equilibrium position and nonlinear stiffness nearby the equilibrium position can be realized by setting certain structural parameters, and the problem about difficulty in isolating low-frequency or ultra-low-frequency vibration for a traditional linear vibration isolation system; stiffness and damping can be easily and conveniently adjusted, vibration isolation of broad frequency domains are satisfied, and good engineering applicability is achieved; the multidimensional vibration platform is high in bearing stiffness, low in movement stiffness, small in static deflection, low in dynamic inherent frequency and good in vibration isolation effect; inherent contradictions restricting the traditional vibration isolation system, namely the contradictions of low-frequency vibration transmissibility and high-frequency vibration attenuation, can be solved by flexible adjustment of the stiffness and damping; the height and the static equilibrium position of the entire platform can be changed by adjusting a shock absorber spring base in height, and the multidimensional vibration platform is applicable to vibration isolation of objects of different weight.
Owner:ANHUI UNIVERSITY OF TECHNOLOGY AND SCIENCE

Load-bearing adjustable zero-stiffness electromagnetic vibration isolator and control method thereof

The invention discloses a load-bearing adjustable zero-stiffness electromagnetic vibration isolator and a control method thereof. An electromagnetic spring of the vibration isolator in the perpendicular direction is composed of three permanent magnets and two groups of controllable direct current electromagnets, two magnets have opposite polarity and generate repulsive force, and stiffness of theelectromagnetic spring can be adjusted by changing and controlling current. An electromagnetic spring of the vibration isolator in the horizontal direction is composed of two groups of symmetrically distributed electromagnetic springs, and stiffness of the electromagnetic spring can be adjusted by changing and controlling current. When the system load-bearing weight is changed, the stiffness of the perpendicular electromagnetic spring and the stiffness of the horizontal electromagnetic spring are led to meet a certain proportional relationship by adjusting and controlling current so that stiffness of the system at the balance position can be zero. When a vibration isolation device is in small vibration near the balance position, dynamic stiffness is very small, and natural frequency of the whole system is very low so that the vibration isolator can achieve wide-range frequency vibration isolation and has good low frequency vibration isolation effect. In addition, the vibration isolator is compact in structure, light in weight and convenient to control.
Owner:HUNAN UNIV

Symmetric rotation piezoelectric generation device

The invention discloses a symmetric rotation piezoelectric generation device which belongs to the technical field of micro energy and is particularly suitable for collecting varying rotation mechanical energy in a low-frequency vibration environment. The generation device consists of a rotation shaft, left and right bases, left and right bearings, left and right piezoelectric bi-crystal beam arrays, an excitation wheel permanent magnet array and an excitation wheel. The excitation wheel is in rigid connection with the rotation shaft; and the rotation shaft is supported in the center holes of the left and the right bases by the left and the right bearings respectively. In the generation device, the left and the right piezoelectric bi-crystal beam arrays are completely symmetric in structure. The excitation wheel permanent magnet array consisting of multiple excitation wheel permanent magnets is uniformly arranged at the periphery of the left side of the excitation wheel; each piezoelectric bi-crystal beam is composed of a permanent magnet block, a copper beam and a piezoelectric ceramic chip; and the piezoelectric bi-crystal beam array consisting of the left and the right piezoelectric bi-crystal beams is uniformly mounted on the left and the right bases. The device transfers the acting force by use of non-contact permanent magnetic force, thereby avoiding the energy loss and service life reduction caused by mechanical impact, and increasing the response bandwidth of a common rotation piezoelectric generation device.
Owner:DALIAN UNIV OF TECH

Measuring device and method for vibration of flexible cantilever on basis of machine vision

The invention discloses a measuring device and method for the vibration of a flexible cantilever on the basis of machine vision. The measuring device comprises a fixed bracket, the flexible cantilever, a camera bracket, a CCD (Charge Coupled Device) camera, a lens, a plurality of LED (Light-Emitting Diode) light-emitting tubes and a PC (Personal Computer), wherein one end of the flexible cantilever is fixed on the fixed bracket; all the LED light-emitting tubes are arranged on the upper surface of the flexible cantilever in sequence; the top of the fixed bracket is provided with the camera bracket; the CCD camera is fixed on the camera bracket and is provided with the lens; and an output port of the CCD camera is connected with the PC. The CCD camera measures each frame image of the vibration of the LED light-emitting tubes, and conveys the images to the PC; and the PC processes a detected image sequence, extracts the position of the mass center of the light spots of the LED light-emitting tubes and acquires the vibration displacement of all the LED light-emitting tubes and parameters for reflecting the low-frequency vibration of the flexible cantilever structure. The measuring device and method disclosed by the invention has the advantages that the non-contact effect is achieved, the measuring range is wide and the vibration characteristic of a measured object is not changed and the like, and can be widely applied.
Owner:NANJING UNIV OF SCI & TECH

Low-frequency vibration-isolation combined sandwiched structure

The invention discloses a low-frequency vibration-isolation combined sandwiched structure. The low-frequency vibration-isolation combined sandwiched structure comprises a lower uniform layer, a middle layer and an upper uniform layer sequentially from bottom to top, wherein the middle layer is of a limited two-dimension photonic crystal structure, the limited two-dimension photonic crystal structure comprises a base body and a plurality of scatters embedded into the base body, the scatters are respectively connected with the upper uniform layer and the lower uniform layer into a whole, and the lower uniform layer, the scatters and the upper uniform layer (3) are all made of rubber materials. The scatters, the upper layer and the lower layer are combined into an integrated body and are made of the same materials. The base body needs to be fixed. The low-frequency vibration-isolation combined sandwiched structure can block incident vibration along a plate and low-frequency vibration perpendicular to the plate through the designed structure, be applied to vibration control within the frequency range of hundreds of hertz, and serve as a low-frequency vibration-isolation facility of projects such as foundations and inner walls of buildings, ships and warships, and high-speed rails.
Owner:XI AN JIAOTONG UNIV

Monitoring device and real-time monitoring method for bridge vibration deformation

The invention discloses a monitoring device and a real-time monitoring method for bridge vibration and deformation. The device comprises a laser emitter, synchronous light receiving and transmitting devices on a plurality of monitoring points, a centralized control and communication device, a remote monitoring center, etc. When a beam emitted by the laser emitter irradiates a reflection and transmission prism of the synchronous light receiving and transmitting device, the beam is split in proportion; a part of the split beam is reflected and received; the other part of the split beam is transmitted and passed, and irradiates a reflection and transmission prism of the next synchronous light receiving and transmitting device; and each synchronous light receiving and transmitting device can collect and store deformation (spot displacement) of a monitoring point, and upload the data of the deformation. The monitoring system can synchronously collect and process data on the deformation of all monitoring points, thereby realizing the measurement for vibration and deformation of a whole bridge. The monitoring device and the monitoring method can be used for measuring the deformation and the low-frequency vibration of various large-scaled bridge buildings. Furthermore, the device and the method have the advantages of rapid and real-time measurement, high accuracy of measurement, and real-time monitoring.
Owner:XI AN JIAOTONG UNIV +1

Real-time diagnosis method for random vibration fault of steam generator set

The invention discloses a real-time random vibration fault diagnosis method for a turbo generator set, relates to the automatic on-line vibration state monitoring of the turbo generator set, and belongs to the fields of vibration state monitoring and fault diagnosis of large rotating machinery. The method comprises the following steps: acquiring bearing pedestal bush vibration signals and shaft vibration signals of a shaft system of the turbo generator set; performing necessary data preprocessing on the vibration data such as calibration conversion, abnormal point elimination and the like; adopting the Fast Fourier Transform (FFT) spectrum analysis method to perform relevance analysis between the bush vibration low frequency vibration and the shaft vibration on the vibration data, and further performing real-time quantitative computation and analysis on the bearing pedestal bush vibration data such as condition verification of low frequency vibration amplitude, the condition verification of the main frequency for the low frequency vibration, the dispersibility verification of low frequency vibration frequency components and the like, and automatically diagnosing in real time whether the random vibration fault occurs in the set by combining various verification results based on the real-time quantitative computation and analysis.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Real-time diagnosis method for oil film whirl fault of large steam turbine-generator

The invention discloses a real-time oil film whirling fault diagnosis method for a large steam turbine generator set, belongs to the fields of mechanical vibration state monitoring and fault diagnosis, and relates to the real-time online monitoring of the vibration state of the large steam turbine generator set. The method comprises the following steps: collecting vibration signals of a rotor shaft of a steam turbine set to carry out necessary data preprocessing on vibration data, judging that the rotating speed of a shaft system of the set is less than twice of a first critical rotating speed of a rotor, further combining the Fast Fourier Transform (FFT) spectrum analysis method to carry out the real-time quantitative computation and analysis of the shaft vibration data such as unicity verification of the main frequency for the low frequency vibration of the shaft vibration, condition verification of the main frequency for the half-frequency vibration of the shaft vibration, the condition verification of the half-frequency vibration amplitude of the shaft vibration and the like, and automatically diagnosing whether an oil film whirling fault occurs in the set based the real-time quantitative computation and analysis and in conjunction with various verification results in a real-time and online manner. The method has the advantages of scientificness, reliable conclusion, automatic realization of the real-time online monitoring and fault diagnosis and the like.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Gravity compensation device

The invention discloses a gravity compensation device which is used for supporting a micropositioner of a worktable and a reticle stage in a photoetching machine and is communicated with a gas circuit of a gas supplying gas source. The gravity compensation device comprises a first gas chamber, a piston, a supporting plate and a pneumatic valve, wherein the piston is supported by the first gas chamber; the supporting plate is used for supporting the micropositioner, is positioned above the piston and is fixedly connected with the piston; and the valve is communicated with the first gas chamber and is used for adjusting the air pressure of the first air chamber. The gravity compensation device has the advantages that: firstly, the gravity compensation device has a simple structure; secondly, the gravity compensation device has lower rigidity so as to isolate low-frequency vibration; thirdly, the gravity compensation device has certain damping so as to reduce resonance; thirdly, the gravity compensation device has no action of exhausting gas to the environment and can be applied to a vacuum environment; and fourthly, when a load changes, the error of a static position of the reticle stage can be eliminated by adjusting the air pressure of the first gas chamber.
Owner:SHANGHAI MICRO ELECTRONICS EQUIP (GRP) CO LTD

Permanent magnet low-frequency multidegree of freedom vibration isolation mechanism based on negative stiffness principle

A permanent magnet low-frequency multidegree of freedom vibration isolation mechanism based on the negative stiffness principle comprises a lower permanent magnet, an upper permanent magnet, a rubber sheet, a lower permanent magnet fixing plate, a rubber fixing seat, an upper permanent magnet fixing plate, a rubber pressure block and a rubber sheet edge fixing pressure ring, wherein the permanent magnets are magnetized in the vertical direction and opposite for same poles. A positive stiffness system is formed by the permanent magnets under the action of repulsive force, the rubber sheet is stretched to a negative stiffness system under the action of repulsive force of the permanent magnets, two systems are combined to form a low-frequency vibration isolation mechanism, the single vibration isolation mechanism can realize three degrees of freedom low-frequency vibration isolation, and three or four systems are combined in parallel to realize the six degrees of freedom low-frequency vibration isolation. The vibration isolation mechanism can be used in vacuum without the input of external energy. The vibration isolation mechanism has the characteristics of simple structure, low cost and easy processing, and can be used in the fields like optics, acoustics, biology, advanced manufacturing equipment, semiconductor manufacturing and precision measurement, etc.
Owner:TSINGHUA UNIV

Three-dimensional vibration isolation device applicable to low-frequency vibration

ActiveCN104033535AAvoid couplingAvoid the phenomenon of aging and fractureNon-rotating vibration suppressionDynamic stiffnessCarrying capacity
The invention aims at providing a three-dimensional vibration isolation device applicable to low-frequency vibration. On a horizontal plane, a decoupling bracket, steel shafts, and an aluminum slide block realizes decoupling of vibration displacement in X and Y directions; a large circular permanent magnet and a small circular permanent magnet serve as negative stiffness elements, and springs serve as positive stiffness elements, thereby forming a low-frequency vibration isolation system of the horizontal plane; in a vertical direction, oblique springs serve as negative stiffness elements due to geometrical characteristics, and a support spring serves as a positive stiffness element to form a low-frequency vibration isolation system in Z direction; and a three-dimensional low-frequency vibration isolation system is formed by combining the two systems. According to the device, the permanent magnets or the springs serve as the negative stiffness elements or positive stiffness elements, lower-frequency vibration isolation is achieved; displacement decoupling in the X, Y and Z directions is achieved; lower dynamic stiffness in the Z direction and an XY plane can be obtained, and a greater carrying capacity can be ensured at the same time; the input energy is not required; and a static balance position can be adjusted to ensure that the vibration occurs near zero stiffness.
Owner:苏州东菱智能减振降噪技术有限公司

Compound vibration drilling device and machining method

The invention discloses a compound vibration drilling device and a machining method. The compound vibration drilling device comprises machine tool spindle motor and a drill bit and is characterized by further comprising a vibration tool handle and a vibration control system. The vibration control system comprises a monitoring system and an executing system. The executing system comprises a low-frequency vibration generator, an ultrasonic vibration generator, a stepping motor, a servo drive motor and an electric brush. The vibration controller controls the low-frequency vibration generator through the servo drive motor and the stepping motor. The vibration controller controls the ultrasonic vibration generator through the electric brush. By means of the machining method, on the basis of traditional laminated component drilling machining, the compound ultrasound or low-frequency axial vibration is adopted according to material attribute differences of different materials, conversion of vibration drilling and common drilling, conversion of ultrasonic vibration drilling and low-frequency vibration drilling and adjusting of vibration parameters in the machining process can be achieved through the vibration controller, and high-quality manufactured holes are obtained.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Hydraulic suspension device, control method and device thereof and automobile

InactiveCN102401077AReduce dynamic stiffnessImprove dynamic stiffnessSpringsJet propulsion mountingAtmospheric airLow frequency vibration
The invention discloses a hydraulic suspension device, a control method and device thereof and an automobile. The hydraulic suspension device comprises a suspension shell, wherein one end of the suspension shell is provided with a rubber lining; the other end of the suspension shell is provided with a connecting shell; a flow channel plate is arranged in the suspension shell; a first liquid chamber is formed between the flow channel plate and the rubber lining; a rubber leather cup is arranged between the flow channel plate and the connecting shell; a second liquid chamber is formed between the flow channel plate and the rubber leather cup; a spiral flow channel is formed in the flow channel plate; one end of the spiral flow channel is communicated with the first liquid chamber, and the other end of the spiral flow channel is communicated with the second liquid chamber; the first liquid chamber is communicated with a decoupling chamber; a decoupling membrane is arranged in the decoupling chamber, and is used for partitioning the decoupling chamber into a liquid chamber which is communicated with the first liquid chamber and an air chamber which is communicated with the atmospheric air; and a channel where the air chamber is communicated with the atmospheric air is provided with a valve. In the technical scheme of the invention, the hydraulic suspension device can have higher vibration isolating performance under high-frequency vibration and low-frequency vibration.
Owner:BEIQI FOTON MOTOR CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products