61results about How to "Low dynamic stiffness" patented technology

Active hydraulic anti-vibration mount comprising two support elements connected by an elastomer body partially delimiting a working chamber filled with liquid, this working chamber communicating by a throttled passage with a compensation chamber separated from said working chamber by a rigid partition. The rigid partition is penetrated by a first regulating nozzle closed by a movable exciting device, and a second regulating nozzle closed by a valve the movements of which are limited to correspond to an amplitude of variation in the volume of the working chamber which is less than 20% of the amplitude of the variations in volume generated by the exciting device.

The invention provides a three degree of freedom micro-vibration suppression platform and a control method thereof, belongs to vibration isolation and suppression devices, and solves problems of complicated structure and complex control method of a prior active-passive composite vibration isolation structure. The platform provided by the invention includes a base platform, a load platform, three sets of single degree of freedom active-passive composite vibration isolation assemblies which are totally identical and a controller. The upper end and the lower end of each single degree of freedom active-passive composite vibration isolation assembly are connected with the load platform and the base platform. The control method provided by the invention includes calculating logic axis translation signals, calculating logic axis control signals, calculating physical axis real time control signals and transmission steps. The platform provided by the invention is simple in structure, adjustable in rigidity, is capable of suppressing and isolating three degree of freedom microvibration in rotation directions of an X axis and a Y axis and a translation direction of a Z axis and is suitable for different occasions. Microvibration of different frequency bands can be dampened effectively and reliable guarantee can be provided for precision machining and measurement equipment in a microvibration environment.

A six-degree-of-freedom micro vibration suppression platform includes a basic platform, a load platform, six sets of single-degree-of-freedom active and passive composite vibration isolation devices that are exactly the same and a controller. Upper and lower ends of each set of single-degree-of-freedom active and passive composite vibration isolation devices are connected with the load platform and the basic platform, respectively. A control method includes: calculating a logical axis signal, calculating a logical axis control signal, calculating physical axis real-time control signals and a transfer step.

The invention discloses a quasi zero stiffness vibration isolator using multilayer squeezing type magnetic spring and oscillating bars. The vibration isolator comprises a main shaft, guiding shafts, the oscillating bars and a multiplayer structure; the multilayer structure comprises an upper roof arranged from top to bottom in sequence, an upper end cover, a negative stiffness unit, a lower end cover, positive stiffness unit and a bottom plate; the main shaft is a center shaft with multilayer structure; the guiding shafts and the oscillating bars are multiple, and are all arranged around the main shaft at fixing intervals; the structure is compact, and has more bearing ability under relatively small size. In addition, the negative stiffness unit and the positive stiffness unit are connected in parallel by the vibration isolator using the principle of magnetic negative stiffness; the vibration isolator has the characteristics of high static stiffness and low dynamic stiffness, the inherent frequency of the vibration isolator can be efficiently reduced, the vibration isolation frequency band is widened, and the vibration isolator is suitable for low frequency vibration isolation; thenegative stiffness unit is in the form of multilayer squeezing type magnetic spring, the stronger magnetic induction intensity can be produced, the negative stiffness of magnetic spring is increased,the negative stiffness unit is suitable for high loading occasion, and a wide range of applications is met.

The invention discloses a semi-active control type vertical vibration isolator with quasi-zero stiffness. The semi-active control type vertical vibration isolator with quasi-zero stiffness comprises a base and a load-bearing platform, wherein the load-bearing platform is mounted in the middle of the base through a spiral spring A; four servo valves are symmetrically arranged at the bottoms of four sides of the base along side walls; each servo valve is successively provided with a hydraulic cylinder controlled by the servo valve, a hydraulic cylinder push rod driven by the hydraulic cylinder and a spiral spring sleeve mounted on the top of the hydraulic cylinder push rod transversely; vertical sliding rods are fixed on the side walls of the base; one end of each spiral spring sleeve is connected to the corresponding sliding rod in a sleeving manner; a spiral spring B is mounted in each spiral spring sleeve; and each spiral spring B is movably connected with the load-bearing platform through a connecting rod. By the semi-active control type vertical vibration isolator with quasi-zero stiffness, low-frequency vibration transmitted from a ground foundation to upper-layer carrying equipment is isolated; meanwhile, an actuating device is introduced in the vertical vibration isolator, therefore, the system still has low dynamic stiffness under the condition of different carrying weights, a vibration isolation system is always in a quasi-zero stiffness state, low-frequency vibration is isolated effectively, and negative effects caused by the low-frequency vibration are isolated to a maximum degree.

The invention discloses a vibration isolator. A positive stiffness component, magnetic damping components and magnetic negative stiffness components of the vibration isolator are arranged between a base board and a middle board in parallel; the magnetic damping components and the magnetic negative stiffness components are evenly arranged on the edge of the base board in the circumferential direction; one swing mechanism penetrates through the center of the positive stiffness component to be connected with the positive stiffness component in series; the swing mechanism isolates vibration in thehorizontal direction through low horizontal stiffness of a flexible swing rod; and each magnetic damping component and each magnetic negative stiffness component are each divided into two coaxial parts which are fixedly connected with the base board and the middle board separately and generate action through electromagnetic force, and no mechanical contact or abrasion is generated. The vibrationisolator capable of achieving horizontal decoupling can achieve high static stiffness and low dynamic stiffness in the vertical direction and vibration decoupling in the horizontal direction and the vertical direction.

The invention provides a controllable damping molecule spring vehicle suspension. The controllable damping molecule spring vehicle suspension comprises a compressible hydraulic cylinder, an incompressible auxiliary cylinder, a piston, molecular spring mixed mediums and a magnetorheological fluid; the compressible hydraulic cylinder comprises an end cap and a cylinder body which are mutually connected, a membrane sheet is arranged at the position between the end cap and the cylinder body, and a cavity formed between the membrane sheet and the cylinder body is fully filled with the molecular spring mixed mediums; the incompressible auxiliary cylinder comprises an auxiliary cylinder body, and the auxiliary cylinder body is arranged at the end, away from the cylinder body, of the end cap in asleeving mode; a first sealing ring is arranged between the inner wall of the auxiliary cylinder body and the outer wall of the end cap to form a sealed chamber, and the chamber is fully filled with the magnetorheological fluid; the piston comprises main pistons and an auxiliary piston, wherein the main pistons and the auxiliary piston are mutually connected, the main pistons are located in the end cap and the auxiliary cylinder body and sequentially penetrate through the end cap and the auxiliary cylinder body to extend to the exterior of the auxiliary cylinder body; and the auxiliary pistonis located in the cavity formed between the membrane sheet and the cylinder body. According to the controllable damping molecule spring vehicle suspension, the structure is simple, performance is superior, and ride comfort and the control ability of a vehicle can be effectively improved.

The invention provides a negative stiffness element with automatic balance position adjusting capacity and a negative stiffness property generation method and application, and relates to the field ofground-based simulation of gravity environment. The negative stiffness element with automatic balance position adjusting capacity and the negative stiffness property generation method and applicationare purposed to solve the problem of variation of mechanical property, caused by variable mass load, of a balance position of an existing high static and low dynamic stiffness supporting system; the dynamic stiffness of the new system is reduced on the premise that the original system balance position is not influenced so as to ensure that the stable balance position of the system in static loading process is the same as that of an original system; when dynamic load acts on the system, the system stiffness is the value of difference between the original system stiffness and the negative stiffness element stiffness. The geometric nonlinear property and adjustable geometric parameter property of a mechanism are utilized, the transverse spring stiffness and the effective length of a roller mechanism are properly set to realize the special negative stiffness property; a mechanism housing and a central vertical column are locked and unlocked to realize the negative stiffness property of opening and closing elements in a special condition. Therefore, the problems that the static displacement beyond the limit due to excessively low system stiffness or the mechanical property of a balancepoint of a quasi-zero stiffness system is damaged due to excessively low system stiffness can be avoided.

Tool bars that are manufactured as a composite, that is, layered devices. The tool bars can have a solid core, covered with a wrapped composite material, and then optionally covered with a metal sleeve. The tool bars are provided with high strength, improved stiffness over prior art tool bars, high density, low coefficient of thermal expansion, high damping capacity, improved rigidity, improved damping, less chatter and vibration, improved work piece tolerance, improved surface finish, increased speed/fee rates, and low production cost.

A method for making a sound-insulating load-bearing floor, includes the following steps: providing a load-bearing floor; applying a sound-insulating material onto the load-bearing floor so as to form a substantially continuous coating layer; allowing the substantially continuous coating layer to dry; wherein the sound-insulating material includes: 40% by weight to 95% by weight, preferably 60% by weight to 90% by weight, with respect to the total weight of the sound-insulating material, of at least one rubber in a subdivided form; 5% by weight to 60% by weight, preferably 10% by weight to 40% by weight, with respect to the total weight of the sound-insulating material, of at least one binding agent including at least one water-dispersible polymer having a glass transition temperature (T_g) of −50° C. to +50° C., preferably of −40° C. to +10° C.

An antivibration support disposed for supporting and dampening loads between external elements, comprising a first and a second rigid member for securing to the external elements, and an elastomer body, connecting respectively the first and second rigid members.

The support also comprises a second body, having dissimilar material properties from the elastomer body, acting in parallel with the elastomer body to support and dampen the loads.

Disclosed is a powertrain mount capable of being installed between a powertrain of a vehicle and a structural body of the vehicle supporting the powertrain to isolate vibration being transmitted between the powertrain and the structural body. The powertrain mount includes a bracket capable of being mounted on the powertrain or the structural body. The bracket has a rubber holder for receiving and supporting a rubber member thereinside. A slant support means is disposed inner side of the rubber holder and disposed slantly with respect to the horizontal plane of the vehicle. The slant support means is provided with a support member connector to which a support member installed in the powertrain can be connected. A rubber member is bonded with outer circumferential surface of the slant support means while surrounding the slant support means. The rubber member is accommodated in the rubber holder in compressed state but not bonded with the bracket to thereby resiliently support between the slant support means and the bracket. The rubber member has a through-hole formed around both ends in slant direction of the slant support means to thereby reduce dynamic stiffness in slant direction.

The invention discloses a rubber material, and a preparation method and a use thereof. The rubber material comprises natural rubber, butadiene rubber, a diaryl secondary amine antioxidant, a dihydroquinoline antioxidant, a physical antioxidant, an activator zinc oxide, stearic acid, a silane coupling agent, carbon black, sulfur, 4,4'-dithiodimorpholine, tetramethylthiuram disulfide, N-cyclohexyl-2-benzothiazole sulfenamide and an anti-scorching agent. The rubber material has the advantages of low damping coefficient, good mechanical strength, good elastic ductility and satisfactory temperature resistance. The preparation method of the rubber material has the advantages of simple steps, convenience in operation, and suitableness for industrial production. An exhaust system cold end hanger made of the rubber material has the advantages of large pulling strength, long service life, wide vibration isolation frequency, and excellent NVH control efficiency in the acceleration stage in the high speed (90 km/h or more) driving process of an automobile.

A suspension fitting for a motor vehicle exhaust system, the fitting comprising a top and bottom strength members interconnected by a resilient system comprising firstly a single central support arm and secondly a flexible limiting ring surrounding the support arm to limit relative travel between the strength members in a direction corresponding to the support arm lengthening. The top and bottom strength members have respective downwardly and upwardly extending rigid limbs which are placed facing each other on a horizontal axis perpendicular to the general direction of the exhaust system so as to come into abutment against each other and limit relative travel between the strength members along the axis.

A work chamber is filled with a hydraulic liquid and is disposed between the legs of the spring body of a hydraulic radial bearing. The work chamber is connected to a compensating chamber via a transfer channel. The desired absorption of disturbing noises in the region of 130 Hz is obtained with a special dimensioning of the cross-sectional area of the work chamber, the dynamic swell stiffness of the spring body and the length (L) and the total cross-sectional area (A₂) of the transfer channel. The ratio of the effective cross-sectional area (A₁) of the work chamber to the cross-sectional area (A₂) of the channel lies preferably between 0.1 and 10 while the ratio of the length (L) of the transfer channel to the total cross-sectional area (A₂) of the transfer channel is in the range of 0.1 to 4.0.

The invention relates to a vibration isolation system (VIS) comprising:—a base (10);—a coupling element (20) to be coupled to a vibration sensitive object;—a vibration isolator (30-34) arranged between the base and the coupling element;—a bellows (50) to be arranged between the VIS coupling element or the vibration isolator and a protective housing (40) surrounding the vibration sensitive object; and—one or more separate damping elements to act on convolutions of the bellow,

A composite conical rubber spring comprises a conical rubber spring body and is characterized in that a hydraulic damping mechanism is arranged in the conical rubber spring body in a sealed mode, and the hydraulic damping mechanism generates dynamic damping along with vertical bearing of the conical rubber spring body so as to provide dynamic rigidity for the conical rubber spring body. The elastic supporting effect of a rubber body in the conical rubber spring body and the dynamic hardening effect of the hydraulic damping mechanism are fully exerted, the requirement for improving the vertical rigidity of a primary suspension system during high-speed running and heavy-load running is met, the running stability of a train is improved, and it is guaranteed that the dynamic change of the vertical rigidity of the composite conical rubber spring in the bearing process meets the variable rigidity requirement. The invention further provides a rigidity design method of the composite conical rubber spring.

The invention provides an intelligent negative stiffness method and device avoiding bearing static loads. According to the method and device, on the basis of a passive negative stiffness component with a transmission shaft, a starting component and a halting component used for controlling the passive negative stiffness component to be started and halted, a motor used for changing the position of the passive negative stiffness component or the length of the transmission shaft, a sensor used for measuring static loads borne by an external static load bearing structure or an above-spring component and a controller used for receiving signals of the sensor and controlling the starting component, the halting component and the motor to be started or halted, the passive negative stiffness technology and the static load isolation technology are adopted, the passive negative stiffness component is directly or indirectly connected to the external static load bearing structure or the above-spring component, the ground or a below-spring component, so that the position of the passive negative stiffness component or the length of the transmission shaft is changed, the purpose of offsetting the static loads exerted on the passive negative stiffness component by the external static load bearing structure or the above-spring component is realized, and the passive negative stiffness component avoids bearing the static loads.

A magnetorheological fluid-based hydraulic mount apparatus (20, 220) for supporting a vibration source on a base is disclosed. A main fluid passage (104, 304) extends between pumping chamber (64, 264) and receiving chamber (66, 266) for passing the fluid therebetween. Electromagnet coil (98, 298) variably generates a magnetic flux across the main fluid passage to variably change the damping stiffness of the mount. A rate dip track passage (120, 320) extends between the pumping chamber (64, 264) and receiving chamber (66, 266) for oscillating the magnetorheological fluid (68, 268) therethrough to decrease the dynamic stiffness of the mount apparatus (20, 220) at predetermined frequencies. A controller (108) applies a current through the electromagnet coils (98, 298) at the predetermined frequencies and frequencies relatively close to and above the redetermined frequencies for substantially preventing the magnetorheological fluid (68, 268) from flowing through the main fluid passage (104, 304) to force the magnetorheological fluid (68, 268) to flow substantially only through the rate dip track passage (120, 320) for preventing a sharp increase in the dynamic stiffness of the hydraulic mount apparatus (20, 220) from occurring at these frequencies.