580 results about "Elastic vibration" patented technology

A power tool with at least one handle, comprises at least one handle [1], a power tool body [12], said handle [1] includes at least a gripping member [2], at least one elastic vibration absorbing members are disposed with said gripping member [2]. Said elastic members [3,4] are attached in an inside bore [13] of said gripping member [2], a rigid connecting member [5] go through said elastic members [3,4] and connected with them. Said rigid connecting member [5] also connect to attachment member [7], said attachment member [7] connect to elastic members [4,6]. Said rigid connecting member can increase the strength of said elastic anti-vibration members and also can protect them from wearing off, said rigid connecting member and said attachment member all connected by said elastic anti-vibration members to said gripping member, so the vibration-absorbing effect is perfect.

The invention provides a hydraulic hard and soft mechanical arm control method based on two-parameter singular perturbation, and relates to the technical field of intelligent machine and robot control. Through the principle of the two-parameter singular perturbation of the method, a reduced order is carried out on a hydraulic hard and soft mechanical arm system to enable the hydraulic hard and soft mechanical arm system to become a fast subsystem driven by representation hydraulic servo, a secondary fast subsystem driven by representation elastic vibration, and a slow subsystem driven by representation wide-range rigid movement, wherein a self-adaptive sliding mode controller is adopted in a fast subsystem control module, an optimal controller is adopted in a secondary fast subsystem control module to restrain the elastic vibration, and a second-order sliding mode controller is adopted in a slow subsystem control module to achieve joint trajectory tracking control. According to the control method based on the two-parameter singular perturbation, the reduced order is carried out on the complex hydraulic hard and soft mechanical arm system, multiple time-scale subsystem controllers are designed, and thus the control method is greatly simplified and is more practical.

An anti-ageing rubber material used for elastic vibration isolating element is formed by rubber base material, an anti-aging system, a stuffing system and a sulfurization system, wherein, the rubber base material is natural rubber or blending material mixed by natural rubber and neoprene, wherein, the weight ratio of the neoprene is 10-20 percent; the anti-aging system includes age inhibitor D, age inhibitor 4010NA, age inhibitor AW and paraffine; the stuffing system is one or more of semi-reinforcing carbon black, high wear-resistant carbon black and white carbon black; the sulfurization system includes accelerator M, accelerator TT, accelerator CZ, accelerator NA-22 and sulfur, zinc oxide, light magnesium oxide and stearic acid; the weight ratio of the material formula comprises 100 parts of rubber base, 4-10 parts of anti-aging system in total, 40-80 parts of stuffing system in total; the sulfurization system can adopt various combined proportions. The rubber material has cheap cost and good anti-aging performance, and can give the elastic vibration isolating element low dynamic to static ratio.

An electro acoustic device and related method for increasing production capacity of wells that contain oil, gas and/or water is disclosed. The electro acoustic device produces vibrations stimulating occurrence of mass transfer processes within the well. The resultant acoustic flow generated in porous media, produced by superposition of longitudinal and shear waves, is developed over a characteristic frequency threshold value specific to water, normal oil and heavy oil, with an acoustic energy density capable of establishing higher fluidity zones in the porous media, promoting mobility and recovery of desired fluid and formation damage reduction in a wellbore. The down hole electro acoustic device is a submerged unit placed in the well producing zone, and consists of an electric generator, one or more electro acoustic transducers, and one or more waveguide systems (sonotrodes) that include tubular type radiators which provide transmission of elastic vibrations into the medium under treatment.

A handle (2) of a hand-held power tool (4), includes an outer sleeve (10) to be gripped by a user, a support element (22) extending at least partially within the outer sleeve (10) along a longitudinal axis (A), a pivot attachment element (6) which at least partially is rotatable with the support element (22) and can be fixed via the handle (2) on the hand-held power tool (4), an elastic vibration-reducing device (24) which encompasses support element (22) and holds the outer sleeve (10) in a radially spaced relationship relative to the support element (22) which has an outer profile (36) with radial outer profile elevations (38) which, at least at the axial height of the vibration-reducing device (24), are arranged at a level of the radial inner profile elevations (44) of an inner profile (50) of the outer sleeve (10).

The invention provides a large mechanical equipment structure dynamic similarity test method, comprising the steps as follows: (1) a basic similarity theorem is adopted, all physical quantities are listed, geometrical quantity, density and elastic modulus are determined as basic physical quantities, and the similarity theorem is written into a dimensionless equation expressed by the basic physical quantity; (2) according to concerned basic physical principle, the similarity ratio of all physical quantities adopts similar relation expression, and the similar relation expression is modified according to a structure elastic vibration similarity equation; (3) similar model material is selected, density similarity ratio and elastic modulus similarity ratio are determined, geometrical quantity similarity ratio is determined, and the similar model design is then completed; (4) a structure dynamic test of the similar model is carried out so as to obtain the dynamic characteristic number which is substituted into the similarity relation expression so as to work out the dynamic characteristic data of the original model which is also the natural vibration frequency. The large mechanical equipment structure dynamic similarity test method realizes the conversion of ultra-large structure dynamic natural frequency with small model, effectively reduces the scales of dynamic test objects, simplifies the test instruments, and reduces the test cost.

A control device capable of executing damping control of outputting a damping torque command that suppresses vibration of a rotational speed of a rotating electrical machine caused at least by elastic vibration of a power transmission mechanism. This is accomplished by using feedback control based on the rotational speed of the rotating electrical machine. The control device executes the damping control by a direct-coupling damping controller when the engagement state of the engagement device is a direct-coupling engagement state in which there is no rotational speed difference between engagement members, and executes the damping control by a non-direct-coupling damping controller different from the direct-coupling damping controller in a case where the engagement state of the engagement device is a non-direct-coupling engagement state other than the direct-coupling engagement state.

An internal condition of a concrete structure is objectively evaluated irrespective of surrounding noise or the shape of a hammer, by placing a vibration sensor in direct contact with a measuring surface so as to directly convert a vibration generated on the measuring surface into a corresponding voltage without the intervention of a medium such as air thereby to quantify the vibration generated on the measuring surface concerned. A structure diagnosis apparatus of the present invention includes a vibration unit for generating an elastic wave in a measuring object of a concrete structure, a vibration detector adapted to be placed in contact with a surface of the measuring object for detecting a component in a predetermined frequency range of an elastic vibration generated on the surface of the measuring object by the vibration unit; and a display device for displaying a maximum amplitude of an output signal of the vibration detector.

The invention discloses a flexible spacecraft underactuated system based on the switching control method and an attitude control method of the flexible spacecraft underactuated system based on the switching control method and belongs to the technical field of spacecraft attitude control. According to the flexible spacecraft underactuated system based on the switching control method and the attitude control method of the flexible spacecraft underactuated system based on the switching control method, a dynamical model of a flexible spacecraft with an execution mechanism completely ineffective is established, coupling, caused by elastic vibration of a flexible accessory, with a rigid body is taken as an uncertainty of the system, a dynamical model of a conversion system is a standard nonlinear model, all states are divided into three sliding model surfaces according to the layering sliding model idea, an equivalent control component is designed for the first layer of sliding model surface according to the Filippov equivalent theorem, a switching control law is designed by means of the second layer of sliding model surface and the third layer of sliding model surface, and a final control law is formed by combining equivalent control input and the switching control law. By the adoption of the flexible spacecraft underactuated system based on the switching control method and the attitude control method of the flexible spacecraft underactuated system based on the switching control method, the defect that in the prior art, a flexible spacecraft can not operate normally under the condition that an actuator becomes ineffective completely during operating of the flexible spacecraft is overcome, and operating reliability of a flexible spacecraft attitude control system is improved.

The invention discloses a synthetic jet device based on electromagnetic drive. The synthetic jet device mainly comprises an electromagnet (1), an assembling shell (2) and a synthetic jet device body (3). The electromagnet (1) adjusts and controls the distance between the electromagnet (1) and an elastic vibration film (3-2) through threads. Current in sinusoidal variation is fed into the electromagnet (1) to generate an alternating magnetic field so as to generate alternating electromagnetic force for a permanent magnet film (3-1). The permanent magnet film (3-1) drives the elastic vibration film (3-2) to vibrate, the pressure of a gas cavity formed by the elastic vibration film (3-2) and a cavity body (3-3) varies, and synthetic jet flow is generated through a jet opening (3-4). The synthetic jet device is low in working voltage, large in non-contact drive force, large in air outlet amount, reasonable in design, simple in structure, and capable of realizing active flow control.

In a constant horse-power type continuously variable transmission, a pressing force supply path using for a rotation-speed control is supplied to one of an input pulley d an output pulley, and an elastic force supply path using for an axial torque control to the then. However, the one pulley is applied only the pressing force as a control element, although the torque of the other pulley can be regulated by the elastic force, so that the frictional force applied to said one pulley cannot be positively regulated, and consequently, axial torque controls of an input shaft and an output shaft cannot be achieved sufficiently. This effect causes the transmission efficiency to deteriorate at both end ranges of a variable speed range. In the present invention, a variable-speed control system for a transmission makes axial torque controls of both the input and output pulleys compensate and hold a low-speed range and/or a high-speed range into a higher transmission efficiency, while cooperating with the semi-elastic force to the one pulley, of which elastic vibration is suppressed by the pressing force thereto to half, and the elastic force to the other pulley. By this way, a band width of an entire transmittable speed range is substantially enlarged.

The invention belongs to the technical field of fluid and structure, and discloses an elastic cylinder vortex-induced vibration rule and coupling mechanism determination method. According to the method, rules of influence to dynamic flow field, vortex shedding frequency, dynamic vortex distribution, stability and vortex-induced vibration of elastic are determined as well as unsteady aerodynamic force interference characteristic and coupling mechanism between flapping wings and the elastic-vibration cylinders by analyzing unsteady aerodynamic force characteristics, flow field variation, vortexshedding frequency and vortex shedding structure distribution rule of the flapping wings. The dynamic fluid characteristics, vortex shedding frequency and vortex shedding structure distribution rule of the flapping wings under variation of parameters such as different flapping angle, flapping frequency and Reynolds number is defined; the vortex-induced vibration vibration rule and coupling mechanism of the elastic cylinders under different flapping angle, flapping frequency, mass ratio, damping ratio, spring stiffness coefficient, flow parameters under different degrees of freedom, and dynamicvortex distribution parameter along with motion of the flapping wings is determined.

A method is disclosed for analyzing the vibrational characteristics of rotating devices, such as hard disk drives and jet engines, that are coupled through bearings to flexible supports. In the method, the rotating device is discretized, for example, using a mesh suitable for finite element analysis. The support is also discretized. The natural frequency of elastic vibration modes for the rotating device is calculated and the natural frequency of vibration modes for the support is calculated. The mode shapes are then calculated and a set of modal basis corresponding to the mode shapes is utilized. Bearing stiffness and damping matrices are input, and the Lagrangian equations of motion are integrated numerically in the modal space, to calculate the vibrational response of the rotating device and support. The modal space results are then transformed into ordinary space. The vibrational analysis may be used to design devices having desired vibrational characteristics.

The invention discloses a multi-degree-of-freedom low-frequency vibration-isolation gasket which comprises a top plate, a bottom plate and an elastic vibration-isolation structure arranged between the top plate and the bottom plate, wherein the elastic vibration-isolation structure comprises a base, a vibration-isolation platform, a vertical spring and forked structures; the vibration-isolation platform and the lower portion of the base are connected through the vertical spring; the vibration-isolation platform and two sides of the base are connected with two forked structures which are arranged symmetrically through forked structure supports; each forked structure comprises long connecting rods, short connecting rods, a bearing and a guiding rod; midpoints of the two long connecting rods are movably hinged; two ends of the long connecting rods are hinged with the short connecting rods movably and respectively; the two short connecting rods are movably hinged through the guiding rod and the bearing, so that a crossed telescoping mechanism is formed; a prestretching spring is connected between positions where two short connecting rods close to the inner side of the base are hinged with the two long connecting rods movably; and guiding rods are connected with the bearings inside the forked structure supports. Compared with the prior art, the gasket achieves the characteristics of three-point supporting and multi-degree-of-freedom vibration isolation and can provide an high-efficiency and excellent processing environment for precision machining.

A positioning apparatus according to the present invention includes: a tabletop having a plane; a plurality of actuators configured to be driven in a direction perpendicular to the plane to move the tabletop; and a control unit configured to measure a frequency response of the tabletop and, when a peak is detected at the resonance frequency of elastic vibration of the tabletop, adjust the thrust distribution ratio for the plurality of actuators to reduce the peak.

The invention relates to an adjustable elastic pipeline support and hanger with a limiting function, and belongs to the technical field of vibration noise control. The support and hanger comprises a composite hoop, a backing board, a cushion block, an intermediate block, a bidirectional threaded sleeve, a locknut, an elastic rubber layer, a sleeve and a base, wherein an external pipeline is fixed through the composite hoop, the cushion block and the backing board; two ends of the bidirectional threaded sleeve are in threaded connection with the backing board and the intermediate block respectively, height adjustment of the support and hanger is realized by adjusting the bidirectional threaded sleeve, and the adjusting range is controllable and accurate; the intermediate block is in support transmission with the sleeve and the base through the elastic rubber layer, and elastic vibration isolation is realized through reasonable design of the elastic rubber layer. The adjustable elastic pipeline support and hanger is reasonable in structural design, compact in structure and convenient to mount and has larger mounting advantages under the condition of arrangement with high space requirement.

The invention discloses an elastic vibration-reduction ballast bed system, which comprises a concrete ballast bed and a low-frequency vibration isolator installed in the concrete ballast bed. An elastic mechanism in the low-frequency vibration isolator consists of a positive stiffness elastic element made of metal rubber or the positive stiffness elastic element and a negative stiffness elastic element which are connected in parallel. The positive stiffness elastic element is a disc spring, a spiral spring, the metal rubber, a metal rubber-spring armour, a metal rubber-lead core composite spring or any series-parallel combination of the disc spring, the spiral spring, the metal rubber, the metal rubber-spring armour and the metal rubber-lead core composite spring. The negative stiffness elastic element is a disc spring or a diaphragm spring. The elastic vibration-reduction ballast bed system can meet requirements of middle-high-grade vibration reduction and has a simple structure. The site construction process is simple and convenient, and consumed materials of the ballast bed are relatively reduced. Therefore, the elastic vibration-reduction ballast bed system is low in construction cost and suitable for popularization and application in the whole line.

The invention belongs to the technical field of aircraft elastic motion modeling, and specifically relates to an elastic motion modeling method of a trailing edge rudder gliding aircraft. The method comprises the following steps: (1) converting an elastic body transverse free vibration into superposition of various mutually independent main vibrations by utilizing modal orthogonality; (2) according to a linear small disturbance hypothesis, under the action of external forces, still describing the transverse vibration of an elastic body approximatively by utilizing modal superposition, and determining a vibration mode function by structural characteristics (rigidity and quality distribution) of the elastic body and a boundary condition of the elastic body; (3) establishing a vibration differential equation according to the d'almbert's principle and other methods; and (4) analyzing the external forces, which comprise an aerodynamic force, a rudder surface control force, a posture jet pipe control force, a rudder surface swinging inertia force and the like, influencing an elastic vibration of the gliding aircraft. A traditional elastic motion modeling method is corrected and improved.

The invention discloses a multidirectional rolling type vibration absorption damper which comprises a metal inner box body and an outer box body which are installed together in a sleeving manner; the outer wall of the inner box body is connected with the inner wall of the outer box body through vertical guide rails; the bottom of the inner box body is fixedly connected with the outer box body through an elastic vibration absorption component; the inner wall of the inner box body is connected with the outer wall of a mass block through shape memory alloy energy dissipation springs; a plurality of metal balls which can roll are arranged in the inner box body and are arranged in spherical grooves of the inner box body; the mass block is arranged on the tops of the metal balls, is contacted and connected with the metal balls, can slide in the inner box body in an arbitrary direction and enables the shape memory alloy energy dissipation springs to deform, so that the mass block has the action of energy dissipation vibration absorption in the horizontal direction; and energy in the vertical direction is dissipated by sliding up and down of the inner box body, and thus the multidirectional energy dissipation vibration absorption action is exerted.

The invention provides a simulation method for an elastic waverider hypersonic flight vehicle. The method includes the following steps that considering influences of aerodynamic heating and variable section inertia moment, an elastic model of a hypersonic flight vehicle free beam structure is established; a model superposition method is used for solving an elastic vibration equation, the intrinsic frequency, damping ratio and intrinsic vibration mode of each mode are solved, and on this basis, an elastic vibration generalized coordinate equation of the waverider flight vehicle is obtained; a computational fluid dynamics method is used for obtaining aerodynamic force and engine propulsion of the flight vehicle; on the basis of analyzing thrust, aerodynamic force and aeroelasticity, a rigid body-elastic coupling model of the hypersonic flight vehicle is established. The simulation method is suitable for performing modeling and simulation on the waverider flight vehicle. On this basis, the established model of the waverider hypersonic flight vehicle is more accurate, and the aerodynamic/propelling/elastic coupling characteristics of the flight vehicle can be reflected better in the process of model simulation.

The invention discloses a multi-physics field-assisted electric resistance welding method for dissimilar metal material. The multi-physics field-assisted electric resistance welding method for the dissimilar metal material includes steps that exerting a magnetic-sound composite field to a piece to be welded after performing oil removing and acid pickling so as to activate the surface of the piece to be welded, carrying out electric resistance welding on the dissimilar metal under the magnetic-sound composite field environment till solidifying the metal at the weld joint, cooling to a room temperature, and stopping exerting the composite field to finish welding the dissimilar metal. The multi-physics field-assisted electric resistance welding method for the dissimilar metal material has advantages that by means of the stirring and shock excitation effects of the magnetic-sound composite field for the melt metal at the weld joint in the welding process, the primary crystal size is effectively reduced, the dislocation density in the crystal is increased, the size of the crystal grain tissue at the weld joint is refined, and the mechanical performance of the weld joint is improved; by means of the magnetic field and high-frequency vibration, the energy generated by elastic vibration is converted into the plastic flow energy of the metal material, the friction power of the welding interface and heat energy, the energy needed for melting base metal for the electric resistance welding can be lowered, and the energy is saved.

The invention relates to a novel sleeper system, and belongs to the field of railway tracks. The novel sleeper system comprises a longitudinal beam type sleeper and an elastic vibration reduction track system, wherein the longitudinal beam type sleeper is formed by connecting longitudinal beam type sleeper units one by one in series; each two adjacent longitudinal beams of the longitudinal beam type sleeper are fixedly connected with each other in the lateral direction through a connecting piece; the opposite longitudinal beam end parts of each two adjacent longitudinal beam type sleeper units are connected with each other through a sleeper connecting piece; the elastic vibration reduction track system comprises a support saddle; the longitudinal beam type sleeper is mounted on the support saddle; and a vibration reduction facility is arranged between the bottom of the longitudinal beam type sleeper and the support saddle. The novel sleeper system has the advantages that due to the longitudinal sleeper, the bending rigidity of a track is enhanced, and deformation of the track caused by repeated load is reduced; as the lateral resistance of the longitudinal beams is enlarged, the irregularity in the vertical direction of the track is reduced, and the maintenance is reduced; and as the longitudinal beams are connected with each other in the longitudinal direction, the settlement of the track at the end parts of the longitudinal beams is provided from being enlarged or damaged easily; and as rail pads are arranged continuously, foundation shake, rolling noise and wave-like deformation of the track are reduced.

The invention discloses a compound attitude control method of a grid rudder and a lateral jet. The compound attitude control method comprises the following steps: S1, carrying out interpolation calculation on original aerodynamic data to obtain an aerodynamic derivative; S2, calculating an elastic body dynamic coefficient according to the aerodynamic derivative and analyzing to obtain an elastic body stability index and a maneuverability index; S3, on the basis of aerodynamic performance analysis, carrying out correction network design based on the lateral jet and the grid rudder respectively; designing a corresponding notching filter so as to reduce influences of elastic vibration; in a designing process, considering the elastic body stability index and the maneuverability index; S4, on the basis of the correction network design and notching filter design, carrying out compound control distribution strategy design on two executing mechanisms including the grid rudder and the lateral jet according to control efficiency. According to the method provided by the invention, the grid rudder and the lateral jet are controlled in a compounding manner and stable control of attitudes of a launch vehicle is realized.