1126results about How to "Reduce vibration amplitude" patented technology

The invention discloses a bone conduction receiver with an air conduction effect. The bone conduction receiver comprises a shell, a vibrating diaphragm assembly, a conduction rod, an electromagnetic conversion device and a micro circuit board, wherein at least one through hole is formed on the shell; and at least one opening and closing device or a sound transmission tube of at least one sound transmission hole opening and closing device is arranged on the through hole. Moreover, the opening and closing device or the sound transmission hole opening and closing device comprises at least one cover plate, wherein the cover plate covers the through hole or a sound transmission hole of the sound transmission tube and is rotationally connected with the shell or the sound transmission tube. The application range of the bone conduction receiver can be enlarged, so that the listening of hearing handicapped is enriched, and the life of the hearing handicapped is also enriched; and the bone conduction receiver can be used for persons with normal hearing besides the hearing handicapped.

The invention relates to a dynamic gas elastic foil bearing with stability and adaptive control functions, comprising a bearing casing, a plurality of bearing pads, an elastic foil, and a piezoelectric ceramics micro displacement actuator. The dynamic gas elastic foil bearing is characterized in that the bearing pads are uniformly distributed along the inner wall of the bearing casing; the bearing pads are welded with a bottom bump foil and one end of a top foil; the other end of the top foil is lapped over an adjacent top foil, wherein the piezoelectric ceramics micro displacement actuator with one end fixed on a set screw and the other end arranged on a jig is connected with two bearing pads; the piezoelectric ceramics micro displacement actuator is connected with a feedback controller PID; an input of the feedback controller PID is connected with an eddy current displacement sensor. The dynamic gas elastic foil bearing with stability and adaptive control functions has the advantages of strengthened equivalent rigidity and equivalent damping of the elastic foil, restrained vibration of rotor system, improved bearing capacity and stability of the bearing, reduced size and structure, increased control precision of displacement, and quickened response speed.

A method and system for controlling operation of a tractor and / or agricultural implement towed by the tractor is disclosed. A vibration sensor is mounted to the agricultural implement to detect the magnitude of vibration, or bounce, on the agricultural implement. Because the magnitude of the vibration is a function of several operating parameters including, but not limited to, the speed at which the tractor is travelling and the downward pressure applied to the agricultural implement, one or more additional sensors are provided to monitor these operating parameters. Each of the sensors generates a feedback signal and transmits it to the controller. The controller is configured to generate an reference signal to control an actuator as a function of the magnitude of vibration and the measured operating parameter. The actuator receiving the reference signal is configured to control operation of the tractor or agricultural implement to reduce the magnitude of vibration.

The invention provides a precise vibration isolation system which comprises a first layer of vibration isolator, a second layer of vibration isolator and a micrometric displacement detector; the first layer of vibration isolator is formed by connecting a first air spring and a magnetorhelogical fluid vibration isolation device in parallel, and the second layer of vibration isolator is formed by connecting a second air spring and a micrometric actuating element in parallel; the second layer of vibration isolator is arranged above the first layer of vibration isolator, and the first layer of vibration isolator and the second layer of vibration isolator are connected in series to be an integral; the micrometric displacement detector is connected with the magnetorhelogical fluid vibration isolation device of the first layer of vibration isolator, and the micrometric actuating element is connected with a vibration measurement sensor; a precise instrument is arranged above the second layer of vibration isolator and connected with the micrometric displacement detector by a vibration measurement light path. By adopting a double layer vibration isolation structure based on control by the micrometric actuating element, the invention can meet the requirement of the precise instrument on low frequency vibration isolation noise reduction and greatly improve anti-vibration capacity of the precise instrument.

The invention discloses an anchor of a warp knitting machine, which comprises an upper bearing plate and a lower bearing plate. The upper bearing plate is provided with a first shaft part extending downwards along the lower end face of the upper bearing plate. The lower bearing plate is provided with a second shaft part extending upwards along the upper end face of the lower bearing plate. The first shaft part and the second shaft part are connected in a sliding mode and are matched in an air-tight mode. Springs and a closed air cavity are arranged between the upper bearing plate and the first shaft part thereof and the lower bearing plate and the second shaft part thereof. Both the cross sections of the upper and lower bearing plates are of a round shape. The first shaft part is of a cylinder shape. The second shaft part is provided with a cylindrical blind hole. The closed air cavity is formed by a first air cavity, a second air cavity and a third air cavity, wherein the first air cavity is formed between the first shaft part and the cylindrical blind hole; the second air cavity is communicated with the first air cavity and is formed by an axial hole arranged along the axial direction of the first shaft part; and the third air cavity is communicated with the second air cavity and is formed by a radial hole arranged along the radial direction of the upper bearing plate. The anchor of the warp knitting machine has excellent vibration reduction performance, can bear a larger load, can be used for preventing a machine bed from being turned over and can be popularized and applied in equipment such as the warp knitting machine and the like.

The invention belongs to the technical field of vibration attenuation and vibration absorption of engineering structures and mechanical structures, and discloses a vibration absorption device of adjustable natural frequency and an engine with the same; wherein, the vibration absorption device of adjustable natural frequency is characterized by comprising a liquid storage tank, a liquid pump, a vibration absorption spring, a vibration absorption mass block arranged at the upper end of the vibration absorption spring, and an additional liquid tank fixed on the vibration absorption mass block. The additional liquid tank is divided into an upper air cavity and a lower liquid cavity by a piston, and the lower liquid cavity, the liquid pump and the liquid storage tank are sequentially connectedby a hose. The vibration absorption device of adjustable natural frequency is arranged on a mounting seat of the engine, and engine vibration is absorbed to the maximum extent by dynamically adjustingthe natural frequency of the vibration absorption device, thus reducing engine vibration.

The invention discloses a vibration damping and energy absorption method for an automobile sub-frame, which comprises the steps of (1) performing finite-element analysis to an sub-frame to obtain the quality, the first-order bending mode and the corresponding maximum displacement site of the sub-frame; (2) arranging a mass block with an elastic damping system to damp vibration and absorb energy; and (3) performing modal analysis and experimental verification on the improved sub-frame to correct the elastic damping system and the mass block parameters. The inventive method does not change the current structure of the sub-frame, and arranges the mass block with the elastic damping system in a specific position on the sub-frame to reduce the vibration amplitude by utilizing the principle of resonance energy absorption, so as to reduce the transmission of vibration toward automobile body. The method can also adjust the frequency of vibration damping and energy absorption devices by adjusting the mass of the mass block and the vertical rigidity of the elastic damping system. The inventive method has the advantages of simple structure and not remarkably increased weight and cost, and can maximally damp transmission of the vibration toward the automobile body.

The invention provides a method for eliminating flow field vortexes in a tubular electrode electrolytic machining interval. The method comprises the following steps that the lateral face of a tubular electrode is punched through a laser punching process; the punched tubular electrode is subjected to corresponding insulating treatment; electrolyte flows downwards in the tubular electrode during electrolytic machining and is sprayed outwards from an outlet in the lower end of the tubular electrode; the electrolyte beam sprayed out of the outlet of the tubular electrode impacts an electrolytic machining area; part of electrolyte is sprayed out of a hole in the lateral face of the tubular electrode; under the impact and disturbance function of the electrolyte sprayed out of the hole in the lateral face, a vortex area of the electrolyte of the machining area is eliminated, and electrolysate is discharged out of the machining area in time in the circular flowing of the electrolyte; and meanwhile, under the function of reactive force when the electrolyte impacts, the amplitude of vibration of the tubular electrode caused by flowing of the electrolyte is reduced. The occurrence of short circuit in the machining process can be effectively reduced by eliminating the electrolysate discharged out of the vortex area and reducing the amplitude of vibration of the tubular electrode, and the process stability of the electrolytic machining of the tubular electrode is improved.

The invention discloses a magnetic suspension bearing control system capable of realizing resuspension after destabilization. Ball bearings are respectively mounted at the positions of two ends of a rotor. Elastic supporting seats sleeve the ball bearings. Protection clearances between slideable supporting seats and the outer rings of the ball bearings can be eliminated after magnetic suspension bearing destabilization. High-frequency vibration possibly generated after the rotor falls is converted into low-frequency vibration in the direction of supporting springs so as to introduce an electromagnetic damping force. If the magnetic suspension bearing control system operates normally according to the judgment, a rotor position control module in a controller is adopted for the magnetic suspension bearing control system; if the magnetic suspension bearing control system operates abnormally according to the judgment, the controller controls the elastic supporting seats to operate, in this like, original high-frequency large-amplitude vibration state is changed into low-frequency larger-amplitude vibration in the direction of the supporting springs; a damping force control module is adopted for controlling the magnetic suspension bearing control system, so that the electromagnetic damping force is applied to the rotor to reduce the vibration amplitude of the rotor; and at last, the damping force control module is converted into the rotor position control module so as to realize resuspension.

The invention provides an excavator bucket tooth, and belongs to the technical field of machinery. The excavator bucket tooth solves the problems of high cost and low working efficiency of the conventional excavator bucket tooth. The excavator bucket tooth comprises a tooth seat with an installation part and a bucket tooth with connecting parts; each of the installation part of the tooth seat and the two connecting parts of the bucket tooth is provided with a pin hole on the same axial line; the installation part of the tooth seat is inserted into a space between the two connecting parts of the bucket tooth and fixedly connected with a snap spring through a pin; the pin is provided with an annular groove, and the snap spring is clamped in the annular groove; the inner end face of each pin hole in the bucket tooth is provided with a sunk hole; and the sunk holes and the annular groove in the pin are positioned on the same vertical plane, and the snap spring is positioned in the sunk holes. The excavator bucket tooth has the advantages of simple structure, long service life and wide application range.

The invention provides a control method for reducing integral vibration of a double-drum washing machine. The washing machine comprises two washing buckets which are of up-down array structures. The control method has the advantages that a certain quantity of water is fed into one washing bucket to increase the weight of an integral outer drum assembly if only the other washing bucket runs, so that the integral gravity center of the double-drum washing machine can decline, and the amplitude of the integral vibration of the double-drum washing machine can be reduced; loads on the washing buckets are detected to determine the washing bucket with the quantity of loads if the two washing buckets are drained simultaneously, the washing bucket with the low quantity of loads is drained at first while the other washing bucket stalls, and the other washing bucket is used as a counterweight of the first washing bucket to reduce the integral vibration of the double-drum washing machine, and only starts to be drained after the first washing bucket is completely drained; the second washing bucket has the large quantity of loads, the gravity center of the second washing bucket is low, eccentricity of the loads of the second washing bucket can be adjusted easily, and accordingly excessive vibration can be prevented.

The invention relates to a permanent magnet type magneto-rheological vibrating isolation support with adjustable rigidity and damping, and belongs to the field of structural vibration control. The permanent magnet type magneto-rheological vibrating isolation support with adjustable rigidity and damping is composed of a magneto-rheological vibration isolator and a lifting platform in a series connection mode. The magneto-rheological vibration isolator comprises an upper cover plate, an inner sleeve, magneto-rheological elastomer, an upper permanent magnet, a lower permanent magnet, a gel bladder and magneto-rheological gel. The lifting platform comprises a handle, a moving plate, an upper fixed block, an upper guide rail set, a first sliding block set, a first X-shaped shear type mechanism, a lower fixed block, a fixed plate, a double-rotation-direction lead screw, a second sliding block set, a second X-shaped shear type mechanism, a bearing, a lower connecting pedestal, an upper connecting pedestal and a lower guide rail set. A rigidity adjusting unit is composed of the upper permanent magnet, the magneto-rheological elastomer and the lower permanent magnet, and a damping adjusting unit is composed of the upper permanent magnet, the magneto-rheological gel and the lower permanent magnet. The separation distance between the upper permanent magnet and the lower permanent magnet is changed through the lifting platform, so that a magnetic field with adjustable intensity is generated, and then continuous adjustment of rigidity and damping of the vibrating isolation support is achieved. The permanent magnet type magneto-rheological vibrating isolation support with adjustable rigidity and damping can meet the requirements of different vibrational excitation for the rigidity parameter and the damping parameter of the vibrating isolation support, is high in environmental adaptability, and has the advantages of being compact in structure and low in cost, and convenient to install, achieving continuous parameter adjustment, and being free of power supply of an external power source.

The invention discloses a pumping hydraulic system which comprises a hydraulic oil pump (1), an energy accumulator (5), a control valve (6) and operating cylinders (7), wherein the hydraulic oil pump is used for pumping hydraulic oil to the operating cylinders through a hydraulic cylinder telescopic control oil line, so as to push piston rods (73) of the operating cylinders to perform reciprocating motion; the energy accumulator is in hydraulic connection to the operating cylinders through the control valve; the control valve is used for controlling the energy accumulator to convey hydraulic oil to piston rod actuating chambers of the operating cylinders during the process of direction change of the piston rods when the piston rods perform reciprocating motion; so as to push the piston rods to change directions. According to the pumping hydraulic system provided by the invention, the energy accumulator and the control valve are adopted, so that the hydraulic oil can be conveyed to the piston rod actuating chambers timely with the help of release of pressure oil in the energy accumulator to push the piston rods to change direction rapidly and reduce response time t of direction change of the piston rods as far as possible, the continuity of concrete pumping is realized, the pumping efficiency is improved, meanwhile, the vibration amplitude of a placing boom is reduced, and the operating performance of concrete construction is improved.

The invention relates to a composite multi-frequency-band vibration isolation trench for a building, belonging to the technical fields of civil engineering and mechanical engineering. The composite multi-frequency-band vibration isolation trench comprises a perforated plate, an irregular plate, fillers, a hollow trench and a wave drag block, and is at least arranged under the earth surface on one side of the building, which faces a vibration source; the perforated plate, the irregular plate, the hollow trench and the wave drag block are sequentially connected with one another according to a direction from the vibration source to the building, and the heights and the widths of the perforated plate, the irregular plate, the hollow trench and the wave drag block are ensured to be consistent; one side of the irregular plate, which faces the vibration source, has a convex-concavo irregular structure, and the other side of the irregular plate is planar; and the fillers are filled in the irregular plate and the wave drag block.

A modified inductive pressure sensor (1) for detecting operating parameters of an electric household appliance such as a washing or drying machine (2), provided with a relatively movable component (3) with respect to the carcass, of the type including a rigid casing (10) accommodating a deformable membrane (11) sensitive to hydraulic pressure, a core (20) made of ferromagnetic material and operatively associated to the membrane, and a winding (21) fixed to the casing and operatively coupled to the core to form a variable inductance inductor (22); wherein a mass (40) is accommodated within the casing (10) and in immediate proximity of said membrane (11), free to move with respect to the casing (10) in at least one direction corresponding to the axis of the winding (21).

The invention relates to the technical field of injectors, in particular to a structure capable of adjusting the area of an outlet of a spraying nozzle. The structure capable of adjusting the area ofthe outlet of the spraying nozzle comprises a top cover, a chassis, a rotating disc, a connecting rod and shielding plates. The top cover is of a cylindrical structure with openings formed in the front end and the rear end. The rear end of the top cover is used for being fixed to the outlet end of the spraying nozzle. The chassis is of a ring-shaped structure. The chassis is fixedly arranged on the front end face of the top cover. The rotating disc is of a ring-shaped structure and arranged on the chassis in a rotating manner. The shielding plates are connected with the chassis and the connecting rod in a rotating manner correspondingly. The connecting rod is connected with the rotating disc in a rotating manner. The number of the shielding plates is multiple. The multiple shielding platesenclose a round hole of the chassis to form a spraying outlet. The axis of the spraying outlet coincides with the axis of a runner in the spraying nozzle, and when the rotating disc rotates, the connecting rod drives the shielding plates to rotate to change the size of the spraying outlet. The structure is simple, the area of the outlet of the spraying nozzle can be regulated and controlled exquisitely, and automatic adjustment can be achieved.

The invention relates to a helical strake vortex induced vibration inhibiting device. The device is characterized by comprising a plurality of strip strakes, a plurality of chucks and a ligature, wherein the strakes are alternately arranged on the outer wall of a marine riser, and are helically arranged along the axial direction of the marine riser; the chucks are alternately fixed on the marine riser, and a plurality of grooves are formed on each chuck; and each strake is arranged in the groove of the chuck corresponding, and is fastened in the chuck through the ligature. The device has a simple structure, and the strakes can adopt a continuous structure to facilitate marine on-site assembly, thus the efficiency of marine on-site assembly is remarkably improved, and the device has remarkable economic benefits, and can be applied to the marine riser widely.

The autoamtic grinding and drilling machine includes adhesive rod fixture to fix ball blank, fixture indexing mechanism and stand, feeder, grinding and polishing wheel, discharger, heating mechanism and water supply mechanism, is characterized by fixture turnover mechanism and fixture stand conveying mechanism on the frame. The fixture stand conveying mechanism includes rails and gear rack mounted to the beam and upright of the frame; and the fixture turnover mechanism comprises gear pair and turnover support capable of moving horizontally and vertically to drive the fixture to turn. The fixture indexing mechanism includes spherical hinge in the middle section of the adhesive rod, cross gimbal and cylinder combination to drive the cross gimbal shift in several directions. The present invention has reasonable fixture structure.

The invention provides a smart household sewage treatment device with a replaceable filter net, and relates to the technical field of sewage treatment. The smart home sewage treatment device with a replaceable filter screen includes a box body, the bottom of the box body is fixedly installed with a foot, the bottom of the foot is bonded with a semicircular suction cup, and the top of the side wall of the box body is connected to a water inlet pipe , The bottom of the side wall of the box body is connected with a water outlet pipe, and the bottom of the box body is fixedly installed with a motor through a fixing frame. The smart home sewage treatment device with replaceable filter can fix the bottom plate and the base by aligning the insertion rod with the bayonet and pressing the top ring, and at the same time complete the installation of the filter. Pulling the rope, when the filter screen needs to be disassembled, pull the pull hook, the insertion rod is moved toward the direction close to the spring by the pulling force, squeezes it, the insertion rod retracts into the inside of the notch, and lifts the entire bottom plate at the same time, the operation is simple and convenient.

The invention relates to the technical field of building earthquake resistance, in particular to a multi-dimensional earthquake-resistant buffer base mechanism for a building house and an implementation method thereof. The multi-dimensional earthquake-resistant buffer base mechanism comprises an outer tube body, a support post, a longitudinal buffer assembly, a spherical surface buffer assembly, afloating hinging assembly, a flexible gasket, a top plate, a buffer rope group and an inside filler, wherein the outer tube body is buried under the ground; the support post is arranged at the bottomof the outer tube body; the longitudinal buffer assembly is fixedly arranged on the support post; the spherical surface buffering assembly is arranged on the longitudinal buffer assembly; one end ofthe floating hinging assembly is connected with the outer tube body; and the other end of the floating hinging assembly is connected with the upper part of the spherical buffering assembly; the bottomof the top plate is connected with the top end of the spherical surface buffer assembly; the flexible gasket is arranged in a gap between the top plate and the outer tube body; one end of the bufferrope group is fixedly arranged at the bottom of the outer tube body, and the other end of the buffer rope group is fixedly connected with the peripheral wall of the spherical surface buffer assembly;and a house is built on the top plate. The multi-dimensional earthquake-resistant buffer base mechanism using the scheme has the advantages that the earthquake-resistant effect is good; the service life is long; and the construction difficulty is small.

The invention provides a vibration isolation device for combining high and low frequency vibration. The vibration isolation device is composed of a base, a concave support table, a fixed bottom plate, a frame, a vertical stiffness-damping mechanism, a locking clamp, a horizontal stiffness-damping mechanism, a movable hinging chain seat, a guide rod and a straight line bearing. A realization device of nonlinear stiffness and nonlinear damping is provided based on special vibration isolation performances of the nonlinear stiffness and the nonlinear damping. A stiffness-damping mechanism comprised by the realization device has low dynamic stiffness to enlarge vibration isolation band and has high static stiffness to ensure that static deformation is small and does not lose stability; and the realization device also uses nonlinear damping to together suppresses the height of formant, and while reducing the height of the formant, the formant is moved left to broaden the vibration isolation frequency band and to suppress the transmission rate at high frequencies.

The invention discloses a coating damping cutter rod. On the base material of the cutter rod is coated a damping material layer which forms a lamination structure together with the base material of the cutter rod to increase cutter rod damping, and vibration kinetic energy of the cutter rod is converted into heat energy by use of coating damping material internal friction, to achieve the purposes of damping, improving machining efficiency and improving machining quality. The inventive coating damping cutter rod can adapt to complex variable machining conditions, effectively reduce or suppress cutter rod vibration during the cutting process, improve stability of the cutting process, and improve machining precision and machining efficiency. The invention also discloses a damping testing method of the damping cutter rod.

The invention provides an energy-saving, highly-efficient and microvibration-type fine linear sieving machine, which solves the technical problems of low sieving efficiency, short life of a screen, higher consumption on electricity required by sieving, and the like in the traditional sieving machine. The linear sieving machine comprises a stander, a feeding port, a coarse powder outlet, a screen, a screen frame for fixing the screen and a vibrating screen bottom, wherein the vibrating screen bottom is fixed below the stander and is provided with a fine powder outlet; the feeding port is formed above the stander; the coarse powder outlet is formed at one side of the stander; the screen frame is provided with shock-absorption spokes capable of reducing the screen surface amplitude of the screen; and a high-frequency micro-amplitude microvibration device is arranged on the vibrating screen bottom. Compared with the traditional linear screen, the traditional rotary vibration screen and the traditional rotary vibration screen having the ultrasonic cleaning function as well, the energy-saving, highly-efficient and microvibration-type fine linear sieving machine disclosed by the invention has the advantages that: on the premise of same powder sieving flow (such as 80Kg / h), the Newton efficiency of sieving can be increased to be above 90 percent from the original 30-70 percent, the service life of the screen is prolonged by more than 10 times, and the energy consumption of electric power required by sieving is only 7-15 percent of the original electric power consumption.

The invention belongs to the technical field of ocean renewable energy utilization, and discloses offshore semi-submersible wind energy and wave energy integrated power generation equipment. The integrated power generation equipment comprises a wind energy power generation mechanism, a semi-submersible platform and a plurality of wave energy power generation mechanisms, wherein the wind power generation mechanism is used for wind power generation and arranged on the semi-submersible platform; the plurality of wave energy power generation mechanisms are separately arranged on the semi-submersible platform and used for consuming wave energy received by the integrated power generation equipment to generate power; when the integrated power generation equipment vibrates under the action of waveenergy, the wave energy power generation mechanisms consume the wave energy to generate electricity as well as elastic deformation to store energy while limiting the movement of the semi-submersibleplatform; and after energy storage is finished, the wave energy power generation mechanisms generate power through an elastic restoring force, so that the vibration amplitude of the integrated power generation equipment is reduced while power generation is carried out by consuming wave energy received by the integrated power generation equipment. According to the integrated power generation equipment, the power generation efficiency and stability are improved, and the practicability is higher.

The invention relates to a method for reducing a welding residual stress of a thick plate by utilizing multi-layer and multi-pass welding interlayer welding residual heat to assist vibration and relates to a method for reducing inner residual stress of a welding piece of multi-layer and multi-pass welding, so as to solve the problems that the safety of the method for reducing the welding residual stress of the thick plate is poor, the adaptability is poor and a welding process is influenced. The method comprises the following specific steps of: step 1, fixing a vibration exciter on a vibration platform; step 2, clamping a work piece to be welded on the vibration platform through a clamping gasket and a work piece clamping plate on a welding clamp; step 3, sweeping frequency before vibration and obtaining a fixed frequency of the work piece to be welded under a sub-resonance frequency by adjusting an exciting force; step 4, welding the work piece to be welded; and step 5, after one layer is welded, carrying out vibration ageing effect treatment according to the fixed frequency determined by the step 3 for 5-12 min under the state of the welding residual heat; and repeating the process until the a welding process is finished. The method disclosed by the invention is used for reducing the residual stress after the welding work piece of the thick plate is welded.

The invention discloses a vibration testing device for a hydropower unit in a hydropower station, comprising four horizontal vibration sensors, a magnetic approach switch, a magnetic sheet type fixed reference point and a signal acquisition instrument, wherein the four horizontal vibration sensors are respectively fixed on an upper rack and a lower rack which are used as two supporting legs; the magnetic approach switch is fixed on the upper rack; the magnetic sheet type fixed reference point is fixed on a rotating shaft; and the horizontal vibration sensors and the magnetic approach switch are respectively connected with the signal acquisition instrument. A vibration attenuation implementing method of the vibration testing device comprises the following steps of: starting up the hydropower unit to test sensor signals of the hydropower unit under different loads; determining an unbalance mass position according to a test curve; carrying out equal-mass weight distribution on the upper end surface and the lower end surface of a rotor of the unit, and testing by changing mass of a distributed weight in equal proportion; and determining the masses of the distributed weights on the upper end surface and the lower end surface of the rotor of the hydropower unit according to the vibration test amplitude values of the two weight distributions. The vibration testing device is simple in structure, and the vibration attenuation implementing method is easy to implement, high in efficiency and capable of synchronously reducing vibration of the hydropower unit caused by a machine, a water flow and an unbalanced magnetic force so as to prolong the service life of the hydropower unit.

Two adjacent blades (11,12) may be connected together by narrow circular-section rods (24) on their mid portions (14). The roots of the blades have standard root mountings (13). The leading edges (16) and trailing edges (17) of the blades are twisted and cambered for maximum performance. Each blade has a shroud segment (19) at its tip (15), interlocking (20) with the adjacent shroud segment.

The invention relates to a method and device for the compression of granular materials. On compressing granular material to give prepared products e.g. concrete paving slabs, a resonance vibrator with an oscillating mass-spring system is applied, which may be energised by a controllable energiser to produce forced oscillation of a given frequency and oscillatory amplitude. The resonant effect, making use of the proximity of the inherent resonance frequency and the exciter frequency permits a reduction in the size of the exciter force. According to the invention, along with an adjustment of the exciter frequency the resonant frequency is also simultaneously co-adjusted by means of a suitable adjuster, in order to be able to g make use of the resonance effect throughout the whole spectrum of the exciter frequencies to be carried out.

The invention relates to a particle damping and vibration reduction machine tool. The machine tool includes a machine tool structural part, a cavity (2) is arranged in the machine tool structural part, and damping particles (3) are sealed and filled in the cavity (2). The machine tool structural parts include a machine tool bed (1), a machine tool top beam (4), a machine tool column (5), a machine tool beam and a machine tool reinforcement beam. In the present invention, not only the steel plate welding technology is used to manufacture a large machine tool bed, but compared with the traditional casting processing technology, it has the advantages of relatively simple manufacturing process, short processing and manufacturing cycle, low cost, and saving metal materials; it can also significantly reduce the vibration of the machine tool amplitude, and has the advantages of small changes to the original structure and small additional mass, which not only ensures the machining accuracy of the machine tool, but also saves a lot of metal materials, reduces manufacturing costs, and plays the role of energy saving and emission reduction.

The invention discloses an overhead cable vibration testing device and a testing method. The device comprises an overhead cable test bench, a fiber grating sensor array, a vibration table, a fiber grating CCD(Charge Coupled Device) demodulation device and a PC(Personal Computer). The surface of an overhead cable on the overhead cable test bench is adhered with the fiber grating sensor array in theaxial direction. The vibration table is located below the overhead cable test bench. The bench top is hinged to the overhead cable. A control port is connected with the PC. The optical interface of the fiber grating CCD demodulation device is connected with the fiber grating sensor array. A data transmission port is connected with the PC. According to the overhead cable vibration test device andthe test method, the vibration of the overhead cable under a real environment is simulated through a vibration table excitation, a range adjustment and the initial tension of the cable, so as to systematically analyze the vibration characteristics of the overhead cable under various complex environments; by optimizing the test method and focusing on monitoring parts where faults are susceptible tohappen, the ultimate vibration parameter on the overhead cable can be accurately grabbed; and compared with an online cable monitoring scheme, the device is convenient to adjust, a high-altitude operation is avoided, and high scientific research value and operability are achieved.