51results about How to "Vibration reduction frequency bandwidth" patented technology

The invention relates to a flexible mechanical arm vibration reducing device and method based on controllable rigidity and controllable damp and belongs to the technical field of vibration control of flexible mechanical arms. The vibration reducing device comprises a flexible mechanical arm, a magneto-rheological vibration reducing device and a linear guide rail assembly playing a connecting role, wherein the flexible mechanical arm serves as a vibration control object, the magneto-rheological vibration reducing device consists of a magnetic circuit iron core, a magnet exciting coil, a coil blocking plate, a magneto-rheological elastic body and a magneto-rheological fluid damper, and the linear guide rail assembly consists of a flexible mechanical arm clamping plate, a guide rail installing beam, a linear guide rail, a sliding block, a magneto-rheological vibration reducing device clamping plate and an elastic body installing plate. The rigidity of the elastic body and the damp of the damper in the magneto-rheological vibration reducing device can be controlled by changing magnet exciting current, accordingly the requirement for internal resonance between the mechanical arm and the magneto-rheological vibration reducing device in a system is met, and vibration energy is consumed through the damper. The flexible mechanical arm vibration reducing device and method based on the controllable rigidity and the controllable damp has the advantages of being wide in vibration reducing frequency band and good in effect and being suitable for large-amplitude vibration reduction.

The invention relates to a nonlinear rail type collaborative tuning damper which comprises an external cavity unit, a spring system, a viscous liquid, an internal cavity unit, a cushioning material and a particle group. Two groove rails which are arranged in the length direction of the cavity are arranged at the bottom of the damper external cavity unit, the internal cavity unit can slide back and forth along the groove rails and is connected with the inner wall of the external cavity through the spring system, the portion between the external cavity unit and the internal cavity unit is filled with the viscous liquid, the inner wall and bottom of the internal cavity are covered with the cushioning material, and the particle group is composed of circular particles with different sizes. Shaking of the viscous liquid enables the internal cavity to move back and forth to consume energy, and friction and collision of the liquid and the container wall provides the damping effect; the structure self-vibration frequency is tuned by the spring system, and the energy is consumed by means of the collision and friction between the particles or between the particles and the cavity wall. According to the nonlinear rail type collaborative tuning damper, the advantages of various dampers are combined, the vibration damping frequency band is wide, the effect is good, and the nonlinear rail type collaborative tuning damper has wide applicability in the field of civil engineering structure vibration control.

The invention discloses a variable mass dynamic vibration absorber control method. A sensor used for collecting main system input and output vibration signals is arranged on a compound system composed of a main system-variable mass dynamic vibration absorber, and when the minimum inherent frequency omega m and the maximum inherent frequency omega n of the variable mass dynamic vibration absorber are used respectively, an amplitude-frequency response curve of a main system in the frequency range (0,omega t] is formed; as for the variable mass dynamic vibration absorber control method, while the main system works, the main system vibration signals are collected through the vibration sensor, and excitation frequency omega exerted by the external world is calculated through fast Fourier transform; the variable mass dynamic vibration absorber is controlled according to the value of the excitation frequency omega. According to the variable mass dynamic vibration absorber control method, the effective vibration reduction frequency band of the vibration absorber can be effectively broadened, the phenomenon of resonance of the main system after the vibration absorber is installed can be eliminated, and performance of the vibration absorber is more stable. No control system or actuator needs to be additionally arranged, and the variable mass dynamic vibration absorber control method is easy to achieve and has good practical value.

The invention provides a spherical multidirectional compound type TMD damper. Two layers of big and small concentric spherical shells are used as a main frame of the spherical multidirectional compound type TMD damper, the two layers of the concentric spherical shells are connected with a support seat through an upper column rod, a lower column rod, a left column rod, a right column rod, a front column rod and a rear column rod, and are fixed to the main structure through the support seat. A large mass ball is located on the innermost portion, the large mass ball are fixed to the inner spherical shell in the upper, lower, left, right, front and back directions through damping springs, and the large mass ball is filled with viscous damping liquid. A certain number of small mass balls are arranged between the outer spherical shell and the inner spherical shell, and the small mass balls are tangent to the spherical shells on both sides. Through the homogeneity of a sphere in all directions, the damper can achieve the multifunctional damping control effect by almost 360 degrees; and in response to the vibration caused by external loads of different intensities, the spherical damper has different damping combinations correspondingly.

The invention provides a horizontal tuning frame type eddy current damper. The horizontal tuning frame type eddy current damper comprises a supporting system, a spring mass system, an eddy current damping system and a negative stiffness system, wherein the supporting system comprises an outer frame and a guide rod; the spring mass system comprises a spring and a balancing weight; the eddy currentdamping system comprises a low-speed end permanent magnet, a high-speed end permanent magnet, a guide rail, a sliding block, a magnetism adjusting plate, a conductor plate and back iron; the negativestiffness system comprises a moving permanent magnet and a fixed permanent magnet; and the damper applies the magnetic field modulation principle and the concept of a negative stiffness nonlinear energy trap. The moving speed of the high-speed end permanent magnet is increased through the magnetism adjusting plate, and the energy consumption efficiency of the damper is improved. The movement of the balancing weight can be promoted through the tangential component of repulsive force between the permanent magnets of the same name, and therefore the vibration reduction frequency band is widened,robustness is better, and the problem that the vibration reduction effect is poor when a traditional tuning mass damper is out of order is solved.

The invention provides a vertical tuned mass ball screw type inerter eddy current damper. The vertical tuned mass ball screw type inerter eddy current damper comprises an outer frame, a vertically-arranged guide rod, a support frame, a mass block, a spring, a permanent magnet, a conductor plate and an iron plate, and a set gap is reserved between the permanent magnet and the conductor plate; and the damper further comprises a vertically-arranged ball screw, a nut, a flywheel and a thrust bearing. When vibration energy of the controlled structure is transmitted to the damper, the mass block iscaused to vibrate up and down, the flywheel is driven to rotate at a high speed through the ball screw, the conductor plate cuts magnetic induction lines of the permanent magnet, and the eddy currentdamping effect is formed; and the back iron can reduce magnetic flux leakage and improve the damping energy consumption efficiency. According to the vertical tuned mass ball screw type inerter eddy current damper, a gap between the permanent magnet and the conductor plate remains unchanged in the moving process of the mass block, so that the distance between the permanent magnet and the conductorplate can be set to be very small, and very large damping force can be generated; the mass block does linear motion, the damping force has no torque on the mass block, the pressure between the mass block and the guide rod is not increased, and the motion is smooth.

The invention discloses a semi-active dynamic vibration absorber for magneto-rheological elastomers and a selection and installation method. According to the semi-active dynamic vibration absorber andthe selection and installation method, multiple layers of cross-shaped cross beams arranged in parallel are fixed to the positions below a bottom frame base located at the bottom of a railway vehiclein a suspended mode through four vertical magnetic conductive rods arranged vertically and penetrating through the four end parts of cross-shaped beam arms; multiple layers of stacked structures which are spaced from each other are formed between multiple layers of grooving vibrators and the cross-shaped cross beams; vertical mounting through holes are formed in the centers of the cross-shaped cross beams; the annular magneto-rheological elastomers are arranged between the mounting through holes and a connecting shaft of the multiple layers of grooving vibrators; the multiple layers of grooving vibrators can vibrate up and down relative to the bottom frame base in the axial direction of the mounting through holes; winding grooves are formed in the beam arms of the cross-shaped cross beams; and excitation coils are wound in the winding grooves. The semi-active dynamic vibration absorber has the advantages that the vibration absorption effect is good, the energy consumption is small, the structure is simple and compact, the installation is easy, the safety and the reliability are high, the utilization of the residual space under the railway vehicle is reasonable, and vertical wide-frequency vibration reduction can be carried out on a railway vehicle body which suffers form an abnormal vibration problem due to the fact that a railway is unsmooth.

The invention relates to a particle-group idler wheel synergistic tuned damper comprising an external cavity unit, limiting springs, a nested-type particle group, an internal cavity unit, metal partition plates, a damping particle group, a damping hole, viscous liquid and a buffering material. Each of the internal cavity unit and the external cavity unit of the damper is a cylinder, the external cavity unit is filled with the viscous liquid, the internal cavity unit is controlled in the external cavity unit through the limiting springs, and by taking the nested-type particle group as idler wheels, the internal cavity unit moves back and forth in the any horizontal direction along with continuous sloshing of the viscous liquid; the interior of the internal cavity unit is divided into a plurality of subspaces through the metal partition plates, damping holes are formed in the vertical metal partition plates, and the subspaces are composed of air, the particle groups and the viscous liquid; back-forth sloshing of the viscous liquid drives the internal cavity unit to move back and forth for vibration reduce; and energy is consumed through friction between the viscous liquid and dampingholes. According to the particle-group idler wheel synergistic tuned damper, the advantages of various dampers are combined, the vibration-reducing frequency band is widen, multi-directional vibration-reducing and energy dissipation are achieved, the efficiency is high, and typical practicability in the field of civil structure vibration control is achieved.

The invention discloses a vibration damper for a ship shaft system. The vibration damper comprises a shaft and a cabin wall for supporting the shaft, two shaft sleeves, two bearings, one barrel-shaped base body and a vibration damping cover which are subject to axial isolation are sequentially and fixedly installed between the shaft and the cabin wall in a sleeving manner from the outer circle of the shaft outwards, the vibration damping cover and the base body are in sealed connection to form a sealed annular cavity body, the cross section of the annular cavity body is in an arc taper shape, and a flange is arranged at the top of the arc taper; a ring-shaped vibration damping sheet provided with a plurality of through holes and extending into the annular cavity body is fixedly embedded at one end of the flange, and the other end of the flange is fixedly connected with the cabin wall; and an oil adding valve and a gas discharging valve which are communicated with the annular cavity body are arranged on a cover face of the vibration damping cover, and vibration damping oil is refueled into the annular cavity body. By means of the vibration damper, through combination of the vibration damping sheet and a perforated plate, vibration damping is achieved through damping of the vibration damping oil, the structure is simple, dismounting and mounting are convenient, different vibration working stations can be met by replacing the vibration damping sheet, and the service life is long.

The invention provides a horizontally tuned cantilever type eddy current damper. The horizontally tuned cantilever type eddy current damper comprises a mass unit, a connecting unit, a rigidity unit, anegative rigidity unit and an eddy current damping unit, wherein the mass unit comprises a balancing weight; the connecting unit comprises a bearing component, an outer connecting plate and a trapezoidal support; the rigidity unit comprises a cantilever plate; the negative rigidity unit comprises a moving permanent magnet, a fixed permanent magnet, a mounting backup plate and a limiting cushion block a; and the eddy current damping unit comprises a low-speed end permanent magnet, a high-speed end permanent magnet, a guide rail, a sliding block, a magnetic adjusting plate, a conductor plate and a back iron. According to the horizontally tuned cantilever type eddy current damper, the magnetic field modulation principle and the concept of a negative rigidity nonlinear energy trap are applied, the moving speed of the high-speed end permanent magnet is increased through the magnetic adjusting plate, and the energy consumption efficiency of the damper is improved; and movement of the balancing weight can be promoted through the difference value of the attraction force between the different permanent magnets, so that the vibration reduction frequency band is widened, the robustness is better, and the problem that the vibration reduction effect is poor when a traditional tuned mass damper is imbalanced is solved.

The invention provides a spatial grid structure distributed rod-inlaid-type tuned mass damper and belongs to the technical field of construction engineering shock resistance and wind resistance. The spatial grid structure distributed rod-inlaid-type tuned mass damper comprises a damper cavity unit, a mass block, a connecting spring, a viscous damper, a guiding rod and sliding balls. The damper cavity unit is a cavity unit in a spatial grid rod piece, and the guiding rod is arranged in a cavity to be used for being connected with the connecting spring, the viscous damper and the mass block. Themass block and the spatial grid rod piece are the same in shape, and the contacting position of the mass block and the guiding rod is provided with the sliding balls which can slide along the guidingrod. According to the spatial grid structure distributed rod-inlaid-type tuned mass damper, when a structure vibrates, kinetic energy of the structure can be transmitted to the mass block through theconnecting spring, so that the kinetic energy of the structure is reduced; energy can be dissipated through the viscous damper, and damping can be conducted on different vibration modes of the structure; the spatial grid structure distributed rod-inlaid-type tuned mass damper has the advantages that the damping frequency band is wide, the structure is simple, and robustness is good, and has wideapplicability in the field of construction engineering shock resistance and wind resistance.

The invention discloses a dynamic vibration absorber with adjustable damping. The dynamic vibration absorber comprises a box, a box cover, a piston and a piston rod; a liquid medium is injected to a cylinder, one end, away from the piston, of the piston rod penetrates the central hole of the box cover to be fixedly connected with a mass block, the rod end and the non-rod end of the piston are respectively and fixedly provided with an upper coil spring and a lower coil spring which are connected with inner walls of two ends of the cylinder, an upper damping connection plate and a lower dampingconnection plate which are in sliding fit with the inner wall of the box are respectively and coaxially arranged between the rod end of the piston and the upper coil spring as well as the non-rod endand the lower coil spring, the upper damping connection plate, the lower damping connection plate and the piston are evenly provided with a plurality of damping holes along the same diameter circumferentially, and the upper damping connection plate, the lower damping connection plate and the piston can rotate relatively around the axis. By the arrangement, large damping can be prevented, good vibration absorption effect is achieved, damping and natural frequency are adjustable, and the dynamic vibration absorber is simple and compact in structure and convenient to disassemble.

The invention belongs to the technical field of energy dissipation and vibration reduction of pipe structures, and particularly relates to a pipe hoop-shaped parallel broadband particle damper and a design method thereof. The pipe hoop-shaped parallel broadband particle damper comprises multiple sections of pipe structures, wherein parallel broadband particle dampers are arranged among the multiple sections of pipe structures; a cylindrical cavity with the axis parallel to the axis of a pipe structure is formed in the pipe hoop-shaped parallel broadband particle damper used for axial damping, and particles are arranged in the cylindrical cavity with the axis parallel to the axis of the pipe structure; and a cylindrical cavity with the axis perpendicular to the axis of the pipe structure is formed in the pipe hoop-shaped parallel broadband particle damper for radial damping, and particles are arranged in the cylindrical cavity with the axis perpendicular to the axis of the pipe structure. The pipe hoop-shaped parallel broadband particle damper and the design method thereof have the beneficial effects that when the pipe structure vibrates, effective control over vibration of the pipe structure is achieved through momentum exchange and collision energy consumption when particles collide with the pipe structure, normal use of the pipe structure is recovered, and adaptability, durability and safety of the pipe structure are improved.

The invention provides a self-tuning vibration absorber, and belongs to the technical field of vibration absorbers. The self-tuning vibration absorber comprises a driving device and an execution unit; the driving device is arranged on a controlled system and electrically connected with a signal acquisition unit arranged on the controlled system, a guide device is arranged on the driving device, a lower supporting block is arranged at the end close to the driving device, the guide device penetrates through the lower supporting block, an upper supporting block is arranged at the top end of the guide device, and the driving device is used for driving the lower supporting block to move; and the execution unit comprises at least four sets of bent plate springs arranged in a circumferential array, at least one set of mass blocks are symmetrically arranged on the two sides of each set of bent plate springs, and the top end and the bottom end of each set of bent plate springs are connected to the upper supporting block and the lower supporting block respectively. According to the self-tuning vibration absorber, the defects that a passive vibration absorber is narrow in vibration absorption frequency band, poor in vibration reduction effect and the like can be overcome, and meanwhile the self-tuning vibration absorber has the advantages of being small in energy consumption and high in stability compared with an active vibration absorber.

The invention discloses a semi-active tuned mass damper based on magnetorheological elastomers, and relates to the field of dampers. The semi-active tuned mass damper based on the magnetorheological elastomers comprises a net rack formed by connecting a plurality of connecting rods and a plurality of damper bodies, wherein two ends of each damper body are connected with at least one connecting rod, each damper body comprises a sleeve, a sliding rod the two ends of which are connected with the inner walls of the two ends of the sleeve respectively, and a magnetic conducting sliding block which is slidably arranged on the sliding rod in a sleeving mode, each magnetic conducting sliding block is fixedly sleeved with two magnetic conducting stacked rings and a magnetic conducting cylinder the inner wall of which is connected with the outer walls of the two magnetic conducting stacked rings respectively, the outer wall of each magnetic conducting cylinder is connected with the inner wall of the corresponding sleeve, a coil located between the two magnetic conducting stacked rings is wound around the outer wall of each magnetic conducting sliding block, and each magnetic conducting stacked ring is formed by coaxially and alternately arranging and connecting a plurality of magnetic conducting rings and a plurality of annular magnetorheological elastomers. According to the semi-active tuned mass damper based on the magnetorheological elastomers, the vibration reduction frequency band is expanded, and vibration reduction can be conducted on the vibration mode with large modal contribution of a main body structure.