57results about How to "Avoid resonant frequency" patented technology

The invention discloses a construction method for reinforcing and repairing an integral wall of ancient architecture. The construction method comprises the steps of site survey and work preparation, wall foundation reinforcement, wall surface treatment, wall reinforcement and wall maintenance. The construction method is simple and easy to implement, scientific and convenient, and has the advantages of fast construction progress, low construction cost, high working efficiency and wide application range. According to the principle of 'repairing the old as the old', the cultural relic value of ancient architectural elements is kept, only damaged parts are repaired and reinforced, and the whole wall does not need to be replaced. The ancient architecture wall is priceless in cultural relic value. By using the method, original parts can be kept when the ancient architecture wall is damaged and loses bearing capacity, and a bearing function is recovered; the method conforms to the principle of 'repairing the old as the old', and is of great significance to the protection of the national cultural relics.

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 an accurate controllable non-contact test piece rotary magnetic field fatigue excitation and vibration test device. The device comprises a vibration damping insulation clamp, a vibration damper, a dynamic balance device, a vibration exciter, an electromagnetic piezoelectric coupling vibration sensor, a test station, a transmission device and an accurate control device. The excitation and vibration test device is suitable for rotary test pieces and especially suitable for vibration characteristic researches on a wind power blade, an engine, a turbine blade, a helicopter rotor and a tail rotor blade, the excitation and vibration test device can vividly simulate vibration fatigue states of rotary test pieces respectively under conditions of 360-DEG all directions, same rotating speed and different excitation forces, same excitation force and different rotating speeds, and different rotating speeds and different excitation forces, the excitation and vibration test device can monitor related vibration characteristic parameters such as the excitation force, the vibration displacement, the vibration speed and the vibration acceleration continuously, and the excitation and vibration test device is suitable for vibration fatigue characteristic analysis on stationary test pieces.

The invention discloses a wall reinforcing structure and method for improving the integrality of historic buildings. According to the wall reinforcing structure and method, the characteristics that most historic buildings are of brick concrete structures, no ring beam is used, and dead loads are large are considered, walls are reinforced through the reinforcing scheme based on offsite component prefabricating and site assembling, and the historic buildings are prevented from being continuously collapsed by vibration. By means of the wall reinforcing structure and method, the structure integrality can be improved, when vibration loads are externally and suddenly exerted, deformation of the walls is effectively controlled, and continuous collapse caused by overall instability of the historic buildings is prevented. Meanwhile, the wall reinforcing structure and method have the advantages of being high in reversible degree, free of working with naked fire in a site, easy to operate, convenient to apply, free of damage to historic building bodies and the like, the effective protection effect can be achieved when the historic buildings and particularly key cultural relics distributed in urban areas with dense buildings are influenced by construction technologies, with vibration characteristics, of municipal administration dismantling projects, metro building blasting projects, metro building deep foundation pit excavation projects, metro building large-diameter pile foundation construction and the like, and the wall reinforcing structure and method have the wide application prospects in the aspect of preventing extreme damage conditions, such as continuous collapse, of the historic buildings.

The invention relates to a spring. Variable section disk Dynamic modeling method of blade system using variable cross-section disk The centrifugal stiffening, rotational softening and Coriolis forceeffects of the whole coupled system are considered simultaneously. The invention can save the experiment cost, and can be used to obtain different dynamic models only by changing the size and blanking parameters of the blade and the variable cross-section disk as well as the rigidity of the spring. At the same time, the accuracy and convenience of the results obtained by this dynamic model can beanalyzed by comparing with the natural frequencies obtained by commercial finite element software. Compared with the commercial finite element software, the semi-analytical method of the invention isadopted for modeling, the degree of freedom of the model is less, and the computational efficiency is higher. In addition, through the analysis of different rotational speed of the spring Variable section disk The dynamic frequency of the blade coupling system can effectively avoid the resonant frequency and reasonably select the working speed to make the system work more stably.

A tuning bar vibrator formed on a substrate and including a vibrating body. The vibrating body is formed into a meander shape as a whole, and a middle vibrating reed is used as a first detection unit. At one end side of the vibrating body, two sensing electrodes are formed and connected respectively to two extended electrodes. A further sensing electrode and a common electrode are formed on a first principal surface of the first detection unit. A common electrode formed on a second principal surface of the vibrating body is connected to the common electrode on the first principal surface via a through-hole. The further sensing electrode and the common electrode are connected respectively to another set of extended electrodes. A tuning bar vibrator that is small in size, may be reduced in profile and may be used as a vibrating gyroscope having a desirable detection sensitivity, and a vibrating gyroscope using the tuning bar vibrator are obtained.

The invention discloses a four-point vibration damping system for a fiber optic rate gyroscope of a launch vehicle. A T-type vibration damper has equal rigidity along three directions, can greatly inhibit the coupling of line angles, can improve the accuracy of the fiber optic rate gyroscope under the mechanical environment, has a wide silicon rubber temperature adaptability range, covers the workambient temperature of the fiber optic rate gyroscope, and has the inherent frequency of 160Hz to 200Hz. The inherent frequency of the internal components of the product is 1000Hz or more. The vibration damper effectively attenuates the high frequency vibration, effectively prevents the resonant frequency of the components and improves the mechanical environment adaptability of the product.

A radiofrequency harvester circuit may be used in a battery-less RFID device. The harvester circuit includes an antenna unit that captures radiofrequency signals and harvesting circuitry coupled to the antenna unit for collecting energy from the radiofrequency signals captured by the antenna unit. The antenna unit is selectively tunable at a plurality of tuning bands that are scanned by selectively tuning the antenna unit at different frequency bands and sensing respective values indicative of the power of radiofrequency signals captured by the antenna unit at the frequency bands scanned. A highest value out of said respective values for the power of radiofrequency signals as well as the frequency band in the plurality of tuning bands of the antenna unit providing the aforesaid highest value are identified and the harvester circuit is operated with the antenna unit tuned at the frequency band providing the highest value thus identified.

An apparatus for compensating for low-temperature torque of an MDPS including a column torque sensor configured to detect a column torque; a vehicle speed sensor configured to detect a vehicle speed; a temperature sensor configured to measure a temperature of the vehicle; a steering angle sensor configured to detect a steering angle of a steering wheel; and a controller configured to calculate an assist torque, calculate a vehicle speed gain and a compensation gain for the temperature and an accumulated steering angle based on the vehicle speed, the temperature and the steering angle, calculate a final compensation gain by applying a compensation gain attenuation rate, calculate a final assist torque by applying the final compensation gain to the assist torque, and output the final assist torque.

The invention relates to a module type secondary vibration isolator. The module type secondary vibration isolator comprises an upper cover plate (1) which is connected with a quality frame plate (4) through an upper portion fastening bolt (2); an upper portion elastic element (6) is clamped in the middle; a base plate (9) is connected with the quality frame plate (4) through a the lower portion fastening bolt (7) and a lower portion elastic element (8) is clamped between the base plate (9) and the quality frame plate (4); the upper portion elastic element, the lower portion elastic element and the quality frame plate form into a secondary vibration isolating system; a detachable exchangeable quality plate (5) is fixed on the quality frame plate (4). The vibration isolator is arranged on the equipment foundation. The module type secondary vibration isolator can be used for secondary vibration isolating and primary vibration isolating (pay attention to resonance avoidance). The module type secondary vibration isolator has the advantages that the inherent frequency is low, the middle quality frame allows tandem connection, the quality is adjustable, and transportation and installation are convenient due to the fact that the vibrator isolator is in an integral structure.

The invention relates to a buffer, which comprises a main body, a cover plate and a porous cylindrical piece. Screw holes are arranged at two ends of the main body, a cavity provided with an opening end is arranged in the middle of the main body, the opening end of the cavity is sealed by the cover plate, the cover plate is provided with a cylindrical end, and the porous cylindrical piece is sleeved on the cylindrical end which is provided with a pressure relief hole. The buffer is connected between a condenser and a differentiator of an air-conditioner to buffer pressure pulse of the gas phase and the liquid phase to reduce vortex and turbulent flow. The transition effect of the buffer damages conditions of refrigerants to produce cavitation as far as possible, the solid frequency of a capillary assembly is changed by adding the buffer, so that the buffer can avoid resonance frequency and reduce vibration and noise of the capillary assembly, and finally abnormal grunting sound and harsh fluttering sound in startup, shutdown and the operation process of the air-conditioner can be removed.

The invention provides an automobile engine suspension cushion assembly which comprises a driving side cushion, driven side cushions and a metal supporting frame. The driving side cushion is arranged on the metal frame and is in interference fit with the metal frame, automobile body longitudinal beams or connecting holes of a chassis are connected with the two ends of the metal frame, the driven side cushions are assembled on the connecting holes and are in interference fit with the connecting holes, and driven side cushion inner sleeve tubes of the driven side cushions and the connecting holes are concentric. The mode that the driving side rubber cushion and the driven side rubber cushions are integrated through the metal support is adopted, the driving side cushion is mainly stressed, the driven side cushions achieve the functions of auxiliary adjusting and vibration isolation and system decoupling, and the ideal vibration isolation effect can be achieved.

The invention discloses a windwheel of large-scale wind power propulsion plant, which consists of windwheel and upright shaft, wherein the axle sleeve is covered on the upright shaft; the axle sleeve connects to cantilever; the cantilever links up to blade; a unit windwheel is composed of axle sleeve, cantilever and blade; the unit windwheel is installed on the upright shaft in short transverse of the upright shaft; at least two units windwheel are installed on the upright shaft. The invention reduces the stress of the windwheel blade, which reduces the cost.

The invention relates to a semi-active vibration isolation system. The semi-active vibration isolation system comprises a basal disc and an upper working table, wherein a vibration isolation mechanism is arranged between the basal disc and the upper working table, and comprises a spring and a buffer device; the buffer device is connected with a sensor placed on the upper working table through a controller. The semi-active vibration isolation system is characterized in that the adjustable buffer device is adopted; the integral vibration isolation system is formed by the adjustable buffer device, the controller, the sensor and the spring. The semi-active vibration isolation system has the benefits that the semi-active vibration isolation system is communicated with the controller through a pressure sensor and the sensor, resonant frequency can be avoided more actively, the vibration convey rate can be improved, the pressure variation and altitude variation caused by movement of upper loads can be responded actively, and the vibration time can be greatly reduced. The semi-active vibration isolation system has the effects that the resonant frequency is reduced actively, and frequencies beyond the resonant frequency can obtain relatively high vibration convey rate.

An optical scanner includes a substrate having a rigid body and a beam, and a layered body having multiple layers, including a lower conductive layer, a interlayer insulation film and an upper conductive layer, the layered body layered on and protruding outward from the rigid body and the beam. The layered body is patterned to form a resonance scanner portion and a vari-focal mirror, the resonance scanner portion (i) made as a part of the layered body and (ii) having an actuator part, and the vari-focal mirror made as a part of the layered body. The layered body including the resonance scanner portion and the vari-focal mirror is patterned to form a mirror driving wire. In such structure, the size of the optical scanner is reduced, and a frequency change of the resonance scanner portion due to the voltage application to the mirror driving wire is suppressed.

A hinge plate is bonded to a base plate and a load beam in a head suspension assembly. The load beam includes a wide section and a narrow section extending forward from the front end of the wide section. The head suspension assembly allows the load beam to have a narrower width based on the narrow section. The load beam is thus allowed to enjoy a reduced weight. The mass is reduced at a position distanced from the centerline of the load beam. This results in a reduction in the inertial force around the centerline in the load beam. The inventors have demonstrated that the resonance frequency of the first torsion mode is allowed to fall in a higher frequency range. The resonance of the head suspension assembly can be reduced.

The invention discloses an auxiliary cooling water pump structure of a nuclear power plant. The auxiliary cooling water pump structure comprises a motor support, a motor, a bearing bracket, a transmission stabilizing shaft and a load shaft; the motor support comprises a bottom plate, a support and a top plate; the motor is fastened on the top plate, and a motor shaft of the motor is connected to a conductor disc; the transmission stabilizing shaft is connected to a pump shaft of a water pump; and the load shaft is connected to one end of the transmission stabilizing shaft, the load shaft is connected to a permanent magnet disc, and the conductor disc and the permanent magnet disc form an asynchronous permanent magnet coupling structure, wherein a thrust bearing is installed on the bearing bracket, installed on the periphery of the transmission stabilizing shaft and is used for bearing axial force generated in operation of the water pump and gravity of the pump shaft in a shutdown state. According to the auxiliary cooling water pump structure of the nuclear power plant, axial force generated in the pump movement process and the gravity of a rotor in the shutdown state can be independently borne; and a vibration transmission path is cut off, and resonant frequency is avoided.

The invention relates to a rapidly rotating vacuum pump comprising a magnet-mounted rotor driven by an electric drive motor and having a fixed constant nominal rotational frequency (fnom). The rotor and the rotor bearing are desinged to enable a reverse rotating resonance frequency (fcrit) of bend critical to be positioned between more than 3% and max 30% of nominal rotational frequency (fnom)for preventing overspeed.

The invention discloses a system used for vibration reduction and capable of changing the structural rigidity. The system is divided into three main parts including a control part, a current transmission part and a magnetic current sheet body, wherein the control part comprises a vibration sensor, a control unit, a relay, a power supply and a fuse, the current transmission part comprises a power supply, a fuse, a relay corresponding switch and an electromagnetic rod, the magnetic current sheet body comprises magnetic conductive rubber and magnetorheological fluid arranged in the magnetic conductive rubber layer, the magnetic current sheet body is mounted and positioned on a tower drum through a mounting rack and an auxiliary mounting rack, and the electromagnetic rod is composed of an ironsheet, a metal spring and a wire and is transversely wound outside the magnetic current sheet body. When the electromagnetic rod is electrified, the electromagnetic rod discharges a magnetic field, the rigidity of the magnetic current sheet body is increased under the action of the magnetic field, and the solid property is shown; and the rigidity of the whole structure can be increased accordingto needs, and the change is rapid and reversible. According to the system, the magnetic field can be added by electrifying the system, so that the structural rigidity is improved, and the vibration and resonance problems are effectively solved.

The invention relates to a hydraulic vibropiling hammer box with adjustable eccentricity, structurally characterized in that upper and lower hydraulic motors are in drive connection with upper and lower motor driving wheels respectively through upper and lower driving shafts; upper synchronous tooth A and upper synchronous tooth B are engaged with one side of the upper motor driving wheel in sequence to form an upper engaging portion; lower synchronous tooth A and lower synchronous tooth B are engaged with one side of the lower motor driving wheel in sequence to form a lower engaging portion;the upper synchronous teeth A and B and the lower synchronous teeth A and B are in key connection with upper eccentric blocks A and B and lower eccentric blocks A and B respectively; the upper and lower engaging portions are connected via an eccentricity adjusting mechanism. The hydraulic vibropiling hammer box has the advantages that the eccentricity adjusting mechanism allows stepless torque adjustment; a spiral swing cylinder and a rotary connector can cooperate such that torque adjustment is simpler; front and rear adjusting shafts are split; axial wear pads and roller bearings help improve the axial / radial bearing capacity of the box herein; rigid synchronous wheels are arranged alternately; the designed structure is compact; the eccentricity adjusting mechanism is arranged on the single side so that maintenance is facilitated.

The invention provides a double-table vibration test device. The double-table vibration test device comprises two auxiliary devices and two vibration devices; each auxiliary device comprises a lifting device and a sliding part; the lifting device is provided with a lifting part; the sliding part is assembled on the lifting part, and the sliding part slides relative to the lifting part in the longitudinal direction; a drilling tool (an object to be tested) is lifted by the two auxiliary devices, so that the weight of the drilling tool does not exceed the maximum bearing capacity of a vibration device, the vibration device is not easy to damage, and the drilling tool is not easy to overturn in the vibration test process.

The invention discloses a detection method and a device for resonant frequency of a locomotive transformer, the detection device comprises a sweep frequency analyzer, a sampling resistor and a computer, the sweep frequency analyzer comprises a signal generator and a high speed capture card, the output port Vs of the sweep frequency analyzer is directly connected with an input port Va, the high speed capture card captures the frequency, voltage and phase signal of the input port Va as the first reference signal; the sampling resistor is connected with the input port Vb of the sweep frequency analyzer, the high speed capture card captures the frequency, voltage and phase signal of the input port Vb as the second reference signal; the sweep frequency analyzer is connected with the computer, the first reference signal and the second reference signal captured by the high speed capture card are inputted into the computer, and the resonant frequency can be found by the software in the computer. The device is simple in structure, convenient to carry and can quickly and exactly detect the resonant frequency of the transformer.

The device includes a solenoid valve (32) having a supply conduit (34) communicating with the delivery of the pump (16), a drain conduit, an electromagnet (46) energizable to control an armature (51) controlling a shutter (44), and reducing means for reducing disturbance in the delivery pressure of the pump (16) when the electromagnet (46) is energized. The reducing means include a chamber (64) having a predetermined volume and located between the supply conduit (34) and the drain conduit; and a fixed shield (91c) having an opening (92) in which slides a small-diameter portion (87) of the stem (52) of the armature (51). The electromagnet (46) is controlled by an electronic unit (31) via a modulator (86) for modulating the duty cycle of the control pulses, and via a circuit (103) for selecting the frequency of the control pulses on the basis of an estimate of hydraulic disturbances depending on at least one operating parameter.