42results about How to "High damping factor" patented technology

The invention relates to a wide-temperature-domain high-damping environment-friendly damping material for an electronic product and a preparation method thereof. The damping material is prepared from the following components in percentage by mass: 40-48% of butyl rubber, 4.2-5% of dioctyl sebacate, 16-19% of brominated p-tert-octyl phenolic resin, 0.3-0.6% of an anti-aging agent, 10-25% of carbon black, 2.0-2.5% of zinc oxide, 0.6-0.8% of stearic acid and 12-15% of an antioxidant. The damping material has good damping vibration reduction performance and good mechanical property in a relatively wide temperature range, and has wide application temperature range, high damping factor and good environmental protection performance, conforms to the requirements of European Union environmental directive ROHS, meets the needs in using various electronic equipment, can be popularized to the vibration control and noise control of the instruments and electronic systems on airplanes, ships and vehicles, and has broad application prospect.

The invention discloses a low-frequency high-damping rubber-based piezoelectric composite material and a preparation method thereof. The composite material is a complex formed by mixing a rubber base material consisting of 100 parts of non-diene rubber, 1.0 to 1.5 parts of vulcanizing agent and 4.0 to 5.0 parts of vulcanizing accelerator, 100 to 500 parts of piezoelectric ceramic powder, 0.1 to 0.5 part of conductive carbon black and 0.5 to 5.0 parts of coupling agent, vulcanizing, polarizing and the like. A novel damping material which has a high damping factor (tan delta is more than or equal to 0.3) at low frequency (1 to 300Hz) can be obtained, an obvious piezoelectric synergistic effect is achieved, and the damping factor (tan delta is more than or equal to 0.2) of the polarized material is obviously improved compared with that of the unpolarized material.

A gear mechanism, in particular for hand power tools, is disclosed which has a driving gear wheel (12), seated on a drive shaft (11) in the manner fixed against relative rotation, and a driven gear wheel (13), meshing with the driving gear wheel and driving a driven shaft (14). To attain high running smoothness of the gear mechanism and a longer service life by reducing the mechanical load on the gearing upon startup and in load peaks that occur during operation, spring-elastic damping elements (22) are located between the driven gear wheel (13) and the driven shaft (14) (FIG. 2).

The invention discloses a wide temperature range acrylate rubber (ACM) based graphene oxide damping material and a preparation method thereof. The method comprises the steps of: adjusting the dosage of oxidant to prepare of a graphene oxide dispersion liquid with certain size and a lot of polar groups on the surface; using mechanical blending method to blend ACM with hindered phenol small molecules, a curing agent and other compounding agents, then performing mixing with graphene oxide by solvent blending method, and conducting drying and vulcanizing so as to obtain the wide temperature rangeACM based damping rubber containing graphene oxide. According to the invention, graphene oxide with a lot of polar groups on the surface, hindered phenol small molecules and ACM are utilized to form astrong hydrogen bond, at the same time, the barrier properties of graphene oxide are utilized to greatly improve the effective damping temperature range of the ACM based graphene oxide damping material (with tan delta being greater than or equal to 0.3) and the damping properties after aging.

The invention discloses a preparation method of a curing agent for high temperature damping polyurethane. The dinitrogen bisfluorene in the structure comprises a special large spatial configuration; the spatial configuration, as a side chain of a polymer, can strengthen the friction steric hindrance between molecular chains, meanwhile, the fused heterocycle structure containing pyridine and the like is utilized to improve the proportion of a rigid segment of polyurethane, so that the damping performance of a polyurethane material in the high temperature environment and the stability of the damping performance are improved. The prepared curing agent is applied to the curing of a polyurethane resin, compared with the traditional curing agent, the curing agent increases the glass transition temperature of the polyurethane material and the damping factor at the medium-high temperature, expands the damping temperature range of the material, and improves the damping performance of the material in the medium-high temperature environment.

The invention provides a nickel titanium memory alloy/polyurethane compound damping panel and a preparation method thereof and relates to a compound damping panel and the preparation method thereof. The invention aims to solve the technical problems that the present surface layer is a 316L stainless steel compound steel panel, the tensile strength is low, the corrosion resistance is inferior and the present compound damping material has inferior damping effect. The preparation method according to the invention comprises the following steps: placing a nickel titanium memory alloy panel and a polyurethane panel into a hot press, and then pressing for 5-20min under the conditions of 185-195 DEG C temperature and 40-50N pressure, and taking out and cooling in air. The tensile strength of the compound damping panel provided by the invention is 600-800MPa; the precipitation volume of nickel ions in Nacl solution is 0.17ug/ml; the tensile strength is high; the corrosion resistance is excellent; a damping loss factor can reach 0.2; the vibration-reducing and noise-reducing effects are good; and the compound damping panel can be widely applied to passenger cars, trains, ships and buildings.

The invention discloses an interpenetrating network emulsion having high adhesive force to a metal substrate material and a synthetic method of the interpenetrating network emulsion. The interpenetrating network emulsion is an interpenetrating network polymer with a core shell structure, and has a solid content of 30-45%; the core of the interpenetrating network polymer with the core shell structure is formed by virtue of polymerization between a nuclear layer monomer and a crosslinking monomer under the action of an initiator; and the shell of the interpenetrating network polymer with the core shell structure is formed by virtue of polymerization between a shell layer monomer and a phosphate functional monomer under the action of an initiator. The emulsion synthesized by the method disclosed by the invention has the following advantages: (1) the adhesive force to the metal substrate material is good; (2) the damping factor is high and can reach a maximum value of 1.3; and (3) the emulsion has a core shell structure of an interpenetrating network.

The invention relates to a three-layer core-shell structure interpenetrating network emulsion having high adhesion force to metal substrate and a synthesis method of the emulsion. The content of a solid in the three-layer core-shell structure interpenetrating network emulsion is 30-45%; the core of the three-layer core-shell structure interpenetrating network polymer is prepared by polymerizing a core layer monomer and a cross-linking monomer in the presence of an initiator; an interlayer of the three-layer core-shell structure interpenetrating network polymer is prepared by polymerizing an interlayer monomer and a cross-linking monomer in the presence of an initiator; and the outer layer shell of the three-layer core-shell structure interpenetrating network polymer is prepared by polymerizing an outer layer shell monomer and phosphate ester monomer in the presence of an initiator. The emulsion has the advantages of good adhesion force to the metal substrate, wide effective damping temperature range (tan sigma is greater than 0.3), high damping factor of which the maximum value reaches 1.2 and good film-forming property.

A decanter type centrifugal separator includes a torque transmission mechanism with enhanced effect of absorbing a torsional vibration. The decanter type centrifugal separator (10) includes a bowl (20) having a cylindrical part (21), a conical part (22), a separated liquid discharge dam part (25), and a dewatered solid discharge port (26); a screw conveyor (40) disposed in the bowl (20) for axially conveying sedimentation solid, and arranged to be coaxial with the bowl (20) to be rotatable at a speed different from that of the bowl (20); a processed liquid feed means (15); a separated liquid discharge port (81); a solid discharge port (82); a drive means (71); and a differential gear unit (50) for generating a difference in speeds between the bowl (20) and the screw conveyor (40). A torque transmission mechanism (60, 61) includes an elastic damping member (67) for receiving a drive force transmission load on a torque transmission surface (66) of a joint flange part (62a, 62b) formed in a joint part (43) of a drive transmission shaft (51) as a source of torsional vibration generation on a side of the screw conveyor (40) between the differential gear unit (50) and the screw conveyor (40) in order to provide flexibility in a direction of rotation and an effect of damping the torsional self-excited vibration in small angles in forward and backward directions generated during transmission of drive force, thereby absorbing the torsional self-excited vibration of the screw conveyor (40) generated during conveyance of treatment substances due to a minute difference in speeds between the bowl (20) and the screw conveyor (40).

The invention discloses a preparation method of a damping material, and belongs to the technical field of preparation of damping materials. The method comprises the following steps: collecting maple slurry and mixing the maple slurry with a spider web; dewatering with concentrated sulfuric acid, and removing impurities to obtain a carbide; stewing the carbide and adding an organic matter in the stewing process; when a jelly is formed, taking out the jelly and spinning while hot; and washing a filament through a potassium permanganate solution, a nitric acid solution, a hydrogen peroxide solution and clean water in sequence, and then carrying out spinning, charring and irradiation to obtain the damping material. The preparation method has the beneficial effects that the preparation steps are simple; the obtained product is wide in temperature range of -60 DEG C to 220 DEG C; the damping factor is high; and the damping and vibration-reducing performance is good.

The utility model relates to a sandwich type sound-permeable window structure form of a ship's wind deflector. The main body is a sandwich structure, including inner and outer constrained layers and a sandwich core. The constrained surface layer is made of fiber-reinforced resin-based composite material or titanium alloy, and the core layer is made of viscoelastic material. The constrained surface layer is closely bonded to the core layer. The invention comprehensively considers the requirements of the structure in terms of strength and acoustic characteristics. In addition to satisfying the structural strength, it also has good sound transmission performance, small insertion loss, large damping factor, and high specific strength, which reduces the noise generated under the excitation of surface turbulent pulsation. Self-noise, thereby reducing the signal interference of flow noise to the sonar antenna.

The invention relates to a 1-3 composite PZT (piezoelectric) fiber/polymer composite damping material and a preparation method thereof, belonging to the field of composite materials. The composite damping material comprises a plurality of PZT fibers polarized along the length direction and a polymer layer coated outside the PZT fibers, and two ends of each PZT fiber are connected with an externalresistor via electrodes led out of the two ends; and the resistance of external resistor is determined according to the formula (I). The PZT property can be obtained by adopting the polarization method along the length direction of the PZT fibers, the external matching resistor is connected in the way of leading out the electrodes via organic conductive silver paste, under the condition that the damping property of the composite damping material is matched with external impedance, the damping factor can be improved by 0.1; under the condition of increasing the applied force, the damping factor can be improved; the greater the storage modulus difference between an organic matter matrix and the PZT fibers is, the more obvious the damping effect is; and the composite damping material can be used as a vibration-damping and noise-reducing material to be applied in the fields of trains, vehicles and the like.

The present invention provides a low-dropout linear voltage regulator circuit, comprising: a first power transistor with a first source, a first drain and a first gate, the first drain is connected to a voltage input terminal, the The first source is connected to the voltage output terminal; the multi-stage amplifier has a first-stage amplifier and a second-stage amplifier, the second-stage amplifier is the rear stage of the first-stage amplifier, and the output end of the second-stage amplifier connected to the first gate; the voltage stabilization compensation module includes a first compensation capacitor and a second compensation capacitor, the first end of the first compensation capacitor is connected to the first node of the first stage amplifier, the The second end of the first compensation capacitor is connected to the first gate, the first end of the second compensation capacitor is connected to the first node of the first-stage amplifier, and the second end of the second compensation capacitor connected to the first source.

The invention relates to the technical field of environmental protection, in particular to a sound insulation material, a manufacturing method thereof and a water purifier. The sound insulation material is prepared from 100 parts of butyronitrile, 1 to 2 parts of modified graphene oxide, 1 to 2 parts of zinc oxide, 1 to 2 parts of stearic acid, 10 to 20 parts of accelerant and 1.2 to 2.4 parts of sulfur, the microstructure of the modified graphene oxide is of a sheet structure, and the modified graphene oxide is uniformly distributed in the sound insulation material to form a network architecture in the sound insulation material. The manufacturing method of the sound insulation material is used for producing the sound insulation material. The water purifier at least comprises the sound insulation material. On one hand, the modified graphene oxide can be well dispersed in a matrix of nitrile rubber, so that the overall crosslinking density of the composite material is improved; on the other hand, the graphene oxide constructs a perfect filler network, the internal friction resistance is increased to a great extent, the loss factor is increased, and the shock absorption and noise reduction effects of the sound insulation material are remarkable through the combined action of the graphene oxide and the loss factor.