39results about How to "Adjust the natural frequency" patented technology

The inventive vibration absorber comprises an execution unit, a control unit and a sensor. The execution unit consists of a magnetic inductor, a coil, a magnetic rheological elastic body, a vibration-absorbing mass block and a base. The above magnetic inductor consists of inner and outer sleeves, or a U-shaped iron-core and an armature or top and bottom plates and a column iron-core. Between inner and outer sleeves, the U-shaped iron-core and the armature or the top and bottom plates are filled the magnetic rheological elastic bodies. By regulating the voltage on the coil, the rigidity and the elasticity of the magnetic rheological elastic body are regulated to make its vibration frequency change, so as to make the vibration frequency of the vibration absorber execution unit is the same as that of the vibration-damping object.

The invention aims to provide a rigidity-adjustable electromagnetic vibration isolator. The structure of a spring steel sheet portion is that an outer layer of spring steel sheets and an inner layer of spring steel sheets are distributed in a bilaterally symmetrical mode and are fixed between an upper fixing plate and a lower fixing plate respectively. Damping materials are filled between the laminated spring steel sheets. The structure of an electromagnet portion is that electromagnetic coils are installed on iron cores, the iron cores are fixed on the upper inner surface and the lower inner surface of an electrician pure iron mounting rack respectively, and the electrician pure iron mounting rack provided with the electromagnetic coils is fixed to the lower fixing plate of the vibration isolator through bolts. The structure of a movable permanent magnet portion is that two adjusting bolts are fixed on the upper fixing plate through nuts respectively, two protruded circular columns are arranged on the center of the upper surface and on the center of the lower surface of a permanent magnet fixing plate, two ring permanent magnets are fixed on the upper surface and the lower surface of a middle plate through the protruded circular columns, and the fixing plate provided with the permanent magnets is connected with the adjusting bolts through the adjusting nuts. According to the rigidity-adjustable electromagnetic vibration isolator, the advantage of good stability of a passive vibration isolator and the advantage of flexible application of an active vibration isolator are integrated.

The invention provides a low-rigidity flexible suspension device for ground gravity-free condition simulation of aerospace products. The suspension device is mainly composed of a suspending truss, an adapter connecting frame, a chain block, an elastic string, and a sensor. Gravity-free condition simulation of products is realized through multi-suspension-point suspending, the suspending force at each suspension point can be independently adjusted, and the mechanical properties of the elastic string are utilized for adjusting the inherent frequency of a suspension system. The suspension device is capable of realizing microgravity condition simulation of detected products, the suspending quantity is not limited, the suspending force at each suspension point can be independently and steplessly adjusted, the suspending force can keep stable for a long time, flexible suspension of detected products can be realized, and the inherent frequency of the suspension system can be adjusted as required, and disturbance to detected products by an outside vibration source can be effectively isolated.

The invention discloses a rear axle mass shock absorber and relates to a shock absorber. The rear axle mass shock absorber comprises a screw, mass inertia blocks, vibration absorption rubber and a mounting bracket. The mounting bracket is formed by a bottom plate and a vertical plate; the vertical plate is provided with a limiting hole; the mass inertia blocks are respectively arranged on both sides of the vertical plate; each mass inertia block is provided with a center round hole; the mass inertia blocks are connected with the vertical plate by the vibration absorption rubber in a vulcanizing manner; the screw is sleeved by a gasket, a nut and a buffer rubber sleeve; the screw passes through the center round holes of the mass inertia blocks, the vibration absorption rubber and the limiting hole of the vertical plate and enables the buffer rubber sleeve to be positioned in the limiting hole of the vertical plate; the two mass inertia blocks, the two pieces of vibration absorption rubber and the vertical plate are locked together by the gasket and the nut, so that lateral compression or stretching deformation of the vibration absorption rubber can be regulated. According to the rear axle mass shock absorber, vibration noise can be reduced; after the rubber is vulcanized and formed, rigidity can be freely regulated; safety performance is good; NVH (Noise Vibration and Harshness) performance of a vehicle can be improved; the development period of the vehicle or the shock absorber product is shortened; the rear axle mass shock absorber is easy to popularize and apply.

The invention provides a quasi-zero stiffness vibration isolator based on a magnetic attraction component and a vehicle. The quasi-zero stiffness vibration isolator comprises magnetic spring mechanisms and an air spring; the magnetic spring mechanisms are symmetrically arranged on two sides of the air spring along the axis of the air spring; the magnetic spring mechanisms comprises 3n permanent magnets, and n is a positive integer; the permanent magnets are longitudinally arranged on a guide tube and linearly move along the guide tube, and adjacent permanent magnets are opposite in different stages; the uppermost permanent magnet is connected with one end of the lowermost permanent magnet, the other end of the lowermost permanent magnet is connected with a bottom plate of the air spring; and the middle permanent magnet is connected with an upper end cover plate of the air spring. According to the quasi-zero stiffness vibration isolator, on the premise that the requirement for the quasi-zero rigidity is met, the problems of the large number of parts of the vibration isolator and the large reserved space are solved, and the negative rigidity can be adjusted by adjusting a control coil based on the electromagnetic induction phenomenon.

The invention relates to a clamping device for clamping tools, with a receptacle (2) encircled by an annular space (3). The annular space (3) is open towards the tool-side face (1a) of the chuck body (1) and towards the receptacle (2) and is closed by a cover (5). On the receptacle side of the inside wall of the cover (5), there is an annular groove (13) in which there is a gasket (12), wherein a liquid can be fed to the annular groove (13) to press the gasket (12) inserted in the annular groove inward and thus to seal off actively a gap formed between the cover (5) and a tool (W) inserted in the receptacle (2).

The invention relates to the technical field of vibration damping of blades or cantilever type rotating structures and provides a combined blade root. The combined blade root comprises a fixed block and a movable block, wherein the top of the fixed block is used for being connected with a blade, the lower portion of the fixed block is provided with a first installation part and an insertion groove formed in the first installation part, a second installation part is arranged on the lower portion of the movable block, the movable block is movably inserted in the insertion groove, a gap is reserved between the movable block and the inner wall of the insertion groove, and both the first installation part and the second installation part are used for being connected with a wheel disc. When vibration is transmitted to a blade root body and the fixed block through the blade, vibration energy is absorbed through friction between the movable block and the fixed block due to the fact that the gap exists between the fixed block and the movable block, resonance between the movable block and the fixed block is avoided, and excessive vibration amplitude of the blade is avoided.

The invention discloses a fluid film lubrication damping technical test platform, relates to a test instrument in the field of fluid lubrication, and particularly relates to a test platform for researching of fluid film lubrication damping characteristics. The fluid film lubrication damping technical test platform comprises a foundation platform, a vibration exciter support, a test piece support assembly, vibration exciters and an oil drum set. The vibration exciter support and the test piece support assembly are mounted on the upper portion of the foundation platform; the vibration exciters are suspended on the upper portion of the vibration exciter support through bolts; the oil drum set is fixedly mounted on the test piece support assembly. The fluid film lubrication damping technical test platform has advantages of novel structure, convenience in installation and maintenance, high reliability, high automation degree and the like and surely has a positive promotion effect on fundamental research and development of the sliding bearing and aerospace fluid film lubrication damping industry after being marketed.

The invention discloses a method for erecting a shock-absorbing ground pump guide pipe of a high-rise building penetrating through a flue hole and relates to the technical field of constructional engineering. According to the method for erecting the shock-absorbing ground pump guide pipe of the high-rise building penetrating through the flue hole, a flue hole periphery pump pipe fixing and bearing system and a shock-absorbing pull rod system are included. According to the method for erecting the shock-absorbing ground pump guide pipe of the high-rise building penetrating through the flue hole, risks of cracking and water seepage of a pump pipe penetrating through the periphery of an interlayer hole structural plate in an existing scheme are fully reduced; vibration reduction suspenders are formed by turn buckles and vibration reduction springs and used for supporting the pump pipe, the vibration reduction suspenders with different elastic coefficients are combined and matched with one another, the overall natural vibration frequency of a pump pipe erecting system is adjusted, and the risk of resonance in the concrete pumping process is reduced. compared with the prior art, the method is advantaged in that in the pump pipe erecting process, assembly and disassembly procedures are simple, permanent and temporary combination is fully embodied, a large amount of disassembly and recovery work in the later period is avoided, and the method better fits the field reality and is safe, economical and efficient.

The invention discloses a hydraulic low-frequency-absorption vibration isolator, and belongs to the field of mechanical vibration control. The hydraulic low-frequency-absorption vibration isolator comprises a hydraulic vibration isolator body and a hydraulic vibration absorber, wherein the hydraulic vibration isolator body comprises a corrugated pipe elastic oil tank and a top cover; the circumferential face of the corrugated pipe elastic oil tank is of a metal corrugated pipe structure, and an oil cavity is defined by the circumferential face of the corrugated pipe elastic oil tank and a baseof the corrugated pipe elastic oil tank; a hydraulic oil channel communicating the oil cavity with the outside is formed in the base; the top cover is in seal fit with the upper end of the corrugatedpipe elastic oil tank, the lower portion of the top cover is of a cylindrical boss structure, and a cylindrical boss is located in the oil cavity; a gap is reserved between the lower end face of thecylindrical boss and the upper end face of the base, and the gap is equal to the limiting distance of the hydraulic vibration isolator body; an exhaust channel communicating the outside with the oil cavity is formed in the top cover; the hydraulic vibration absorber comprises an external guide pipe and an external hydraulic oil cylinder; and the external hydraulic oil cylinder is connected with the hydraulic oil channel through the external guide pipe. According to the hydraulic low-frequency-absorption vibration isolator, dual vibration isolation of mechanical vibration broadband and line spectrum can be achieved, and meanwhile the use requirements for large bearing force and uniform bearing are met.

The invention discloses an aero-engine squirrel-cage bearing sleeve fatigue life assessment test platform, and relates to the technical field of bearing sleeve life assessment test equipment, in particular to a test platform for assessing the fatigue life of an aero-engine squirrel-cage bearing sleeve. The system comprises a basic platform, a mechanical test bench and a monitoring and control system. The mechanical test bench is arranged at the upper part of the foundation platform; a squirrel-cage bearing sleeve is assembled on the mechanical test bed; and the monitoring and control system is separately mounted with the basic platform and the mechanical test bench, is arranged at a safe position outside the basic platform and the mechanical test bench, is connected with the basic platform and the mechanical test bench through data lines, and controls and monitors the basic platform and the mechanical test bench. According to the technical scheme, the problems that in the prior art, the requirement for the precision of a test bed is high, the cost is high, and the precision and safety of an experimental result are difficult to guarantee are solved.

The invention discloses a massage chair device which comprises a massage chair body, an energy collection device and an energy storage device. The massage chair body is used for generating vibration,the energy collection device is arranged on the massage chair body and used for converting mechanical energy generated by the massage chair body into electric energy, the energy storage device is electric connected with the energy collection device and receives the electric energy transmitted by the energy collection device and a display device is arranged on the massage chair body and comprises adisplay screen, a supporting rod and a shaft sleeve. The energy collection device and the display device are arranged on the massage chair body, the energy collection device can convert the mechanical energy generated by vibration of the massage chair body and store the same, and the display device can realize video watching during massage.

The invention relates to a vibration absorption device suitable for a satellite platform and a using method, and the vibration absorption device suitable for the satellite platform comprises a base which is connected to the satellite platform, and the satellite platform is provided with vibration equipment and a sensitive load. A plurality of groups of vibration absorption assemblies are arranged on the base, each group of vibration absorption assembly comprises a mounting rod connected to the base and a mass block assembled on the mounting rod in an exchangeable manner, and the mounting position of the mass block on the mounting rod is adjustable. A mass spring damping system can be formed through the mounting rod and the mass block assembled on the mounting rod, the inherent frequency of the vibration absorption assemblies can be adjusted through the replaceable mass block and the adjustable position of the replaceable mass block on the mounting rod, and resonance of vibrations caused by the vibration absorption assemblies and vibration equipment is facilitated. Therefore, vibration energy generated by the vibration equipment is transferred to the vibration absorption assemblies in a mode that the base is connected with the satellite platform, so that the micro-vibration effect of the system is reduced.

The invention relates to a semi-active energy recovery vibration absorber. The semi-active energy recovery vibration absorber comprises a vibration absorption mechanism and a friction power generationmechanism, the vibration absorption mechanism comprises an elastic air bag which is installed on equipment to be subjected to vibration absorption through a fixing mechanism, the friction power generation mechanism comprises a first electrode and a second electrode, the first electrode is arranged on the outer side face of the elastic air bag, the second electrode is arranged on one side, close to the elastic air bag, of the fixing mechanism, the first electrode and the second electrode generate periodic contact separation through elastic air bag deformation to achieve contact friction powergeneration, the first electrode and the second electrode are connected with an external circuit to supply power to the external circuit, the vibration absorber further comprises an adjusting mechanism, the adjusting mechanism comprises an inflation hole which is formed in the elastic air bag and a balance weight part which is installed on the elastic air bag, rigidity of the vibration absorber ischanged by adjusting air pressure in the elastic air bag, and the mass of the vibration absorber is changed by changing the weight of the balance weight part. According to the semi-active energy recovery vibration absorber, the problems that the mass and rigidity of an existing vibration absorber are fixed, the inherent frequency cannot be adjusted, and energy generated by vibration cannot be utilized can be effectively solved.

The invention discloses an intelligent undamped dynamic vibration absorbing system. The dynamic vibration absorbing system comprises a control system and a dynamic vibration absorber; the vibration absorber comprises a bottom plate, a lower mass block, an upper mass block and a stepping motor; the stepping motor is mounted on the upper side of the upper mass block; a motor shaft of the stepping motor penetrates through the upper mass block to be connected with a sleeve; a screw rod is arranged on the lower mass block; the upper end of the screw rod is connected with the sleeve; a guiding rod is vertically arranged on each of two opposite sides of the stepping motor; an upper connecting piece is arranged on the lower side of the lower mass block; a lower connecting piece is arranged on theupper side of the bottom plate; the upper connecting piece and the lower connecting piece are connected through an elastic steel plate; and the control system is connected with the stepping motor. Thesystem is simple in structure and convenient to control; the inherent frequency omega0 of the undamped dynamic vibration absorber can be equal to the automatic tracking working frequency omega through control by the aid of the control system, so that the purpose of effective vibration absorbing is achieved; and the whole vibration absorbing system is lower in cost.

The invention discloses a high-stability vibration absorber. The high-stability vibration absorber comprises a supporting assembly, a mass assembly and a spring assembly; the whole mass assembly is ofa cylindrical structure, three or more through holes are formed in the end face of the mass assembly in the circumferential direction, one spring assembly is arranged in each through hole, the threeor more spring assemblies clamp the mass assembly from different positions correspondingly and fix the mass assembly in the supporting assembly, wherein mass of the mass assembly is adjustable, and each assembly is made of a metal material.