42results about How to "High shear yield stress" patented technology

The invention discloses an anti-impact MPP (molypermalloy powder core) electric protection tube. The anti-impact MPP electric protection tube is prepared from the following raw materials in parts by weight: 90-110 parts of polypropylene, 5-15 parts of ethylene-propylene-diene monomer, 10-25 parts of talcum powder, 3-10 parts of brucite powder, 5-12 parts of modified micro silicon powder, 0.8-2 parts of colouring agent, 5-15 parts of nano mica, 0.5-2 parts of antioxidant, 0.5-2 parts of polytetrafluoroethylene, 10-25 parts of modified shell powder, 5-15 parts of modified hectorite, 5-25 parts of novel organic montmorillonite, 5-18 parts of melamine cyanurate, 10-25 parts of modified crystal whisker, 15-30 parts of long glass fiber, 3-8 parts of expandable graphite and 5-20 parts of intumescent flame retardants. The anti-impact MPP electric protection tube has excellent impact resistance, flame retardance, ageing resistance, cold resistance and heat resistance.

The invention discloses a high-performance magneto-rheological fluid, which comprises the following materials in percentage by weight of the magneto-rheological fluid: 50 to 80 percent of mixed magnetic granules of nano-scale carbonyl iron powder and carbonyl iron powder, 10 to 40 percent of carrier liquid, 0.5 to 2 percent of surfactant, 0.5 to 2 percent of thixotropic agent, 0.5 to 2 percent of antioxidant, 0.5 to 2 percent of solid lubricant, and 0.5 to 2 percent of dispersant. The high-performance magneto-rheological fluid of the invention has good anti-settling stability; and after the magneto-rheological fluid is stood for 1 year, the magneto-rheological fluid still has good stability and anti-settling property by observing the stability thereof. Meanwhile, the shear yield stress of the magneto-rheological fluid is obviously improved, and the shear yield stress of the high-performance magneto-rheological fluid can reach 60 kPa under an external magnetic field (1T).

The invention discloses a piezoelectric extrusion type magnetorheological clutch, which comprises a casing with a cylindrical through hole, wherein a coil is arranged in the casing, a driving disc and a driven disc are arranged in the through hole, magnetorheological fluid is arranged between the driving disc and the driven disc, the work surface of the driving disc is provided with at least two circles of concentric convex strips, the work surface of the driven disc is provided with at least two circles of grooves matched with the convex strips, a stacked piezoelectric drive used for driving the driven disc to move towards the driving disc in an axial direction is arranged on the driven disc, and a fine adjustment device used for accommodating redundant magnetorheological fluid is arranged on a driving shaft. A transfer torque calculating method of the piezoelectric extrusion type magnetorheological clutch is characterized in that the transfer torque T extrusion of the clutch is shown as the accompanying drawing. The piezoelectric extrusion type magnetorheological clutch has the advantages that a piezoelectric stacked actuator extrudes the magnetorheological fluid, and the shear yield stress of the magnetorheological fluid can be improved, so the torque transfer capability is greatly enhanced, the energy consumption is low, the transfer capability control capability of the clutch is high, and the sealing performance is good.

This invention belongs to compound material and function material technique field and in detail to light magnetic particles with magnetic rheologic liquid and its process method. The material uses nanometer tube special electromagnetism property and a layer of Fe#-[3] O#-[4] on the surface. It in detail is processed with the nanometer tube, dispersant, strong acid, trivalence iron salt, two iron salt and alkali as certain weight proportion through certain process.

The invention belongs to compound material and function material technological field, concretely are a shallow magnetic compound micro particle for magnetic rheologic liquid and its preparing method. The micro ball is formed by covering a layer of Fe3O4 on the shallow polystyrene micro ball, and it is comprised of shallow polystyrene micro ball, trivalent ferric salt, bivalent ferric salt, dispersant and alkali which are mixed by proper ratio. Through supersonic dispersion, covering micro particle and after-procession, the product is made. The product made by the invention has small density, good magnetic performance, high shearing stress and outstanding depositing stability.

The auxiliary braking device with magnetic rheological body for petroleum rig includes one cylinder of non-magnetic conductive material and two end caps of magnetic conductive material to form one sealed cylindrical cavity, two magnetic conductive columns with wound exciting coil outside the cylinder and between the two end caps, one shaft of non-magnetic conductive material with fixed magnetic conductive blades set between the two end caps, and magnetic rheological body filled in the sealed cylindrical cavity. The present invention can provide great braking moment at all rig winch speeds, and has stepless regulation of braking moment, fast response, low cost and long service life.

The invention discloses a high-performance magnetorheological fluid which comprises the following components in percentage by weight: 50-80% of mixed carbonyl iron powder, 10-40% of carrier liquid, 0.5-2% of surfactant, 0.5-2% of thixotropic agent, 0.5-2% of antioxidant, 0.5-2% of solid lubricant and 0.5-2% of dispersant. Compared with the prior art, by adding a small amount of nano carbonyl iron powder into micron carbonyl iron powder, the invention can obviously improve the sedimentation stability of the magnetorheological fluid and can improve the shear yield stress of the magnetorheological fluid under a magnetic field. After standing for 1 year, the magnetorheological fluid can still show favorable sedimentation resistance and aggregation resistance. The magnetorheological fluid disclosed by the invention can be widely used in the fields of aerospace, machinery, intelligent vibration damping of vehicles or civil building structures.

The invention discloses an anti-aging MPP (modified polypropylene) electric tube which is prepared from the following raw materials in parts by weight: 100-150 parts of polypropylene, 5-10 parts of light calcium carbonate, 1-8 parts of flake talcum powder, 2-10 parts of calcined kaolin, 1-5 parts of brucite powder, 20-40 parts of modified micro silicon powder, 0.2-3 parts of colorant, 2-10 parts of novel nucleating agent, 1-2.7 parts of antioxidant, 0.5-3 parts of polytetrafluoroethylene, 2-12 parts of master batch, 5-20 parts of melamine cyanurate and 5-15 parts of modified crystal whisker. The preparation process of the novel nucleating agent comprises the following steps: adding 150-180 parts of p-tert-butyl benzoic acid into 200-300ml of tetraisopropyl titanate, reacting at 90-130 DEG C for 3-5 hours, adding 100-150ml of silicate to obtain a solution A, adding the solution A into an ethanol-water mixture, hydrolyzing at 50-65 DEG C for 3-5 hours, filtering, and drying to obtain the novel nucleating agent. The anti-aging MPP electric tube has the advantages of high aging resistance, excellent impact resistance, excellent freezing resistance and excellent heat resistance.

The invention discloses an electric heating extrusion disc magneto-rheological and electromagnetic bearing bush friction combined transmission device. The electric heating extrusion disc magneto-rheological and electromagnetic bearing bush friction combined transmission device comprises a driving shaft, a driven shaft and a transmission shell, wherein the part, located in a driven shell, of the driving shaft is expanded to form a transmission section; two armature tiles are symmetrically arranged on the transmission section, and a guide column and a compression shape memory alloy spring are arranged in the middle of the inner side of each armature tile; a liquid containing groove is formed in the outer side of each armature ring, and each liquid containing groove is filled with magnetorheological fluid; extrusion discs are correspondingly arranged between two ends of the transmission section and a left end cover and between two ends of the transmission section and a right end cover, and the guide rods and the extrusion shape memory alloy springs are arranged at one sides, close to the transmission section, of the extrusion discs; a gap between the extrusion disc close to the left end cover and the left end cover and a gap between the extrusion disc close to the right end cover and the right end cover are also filled with magnetorheological fluid. According to the electric heating extrusion disc magneto-rheological and electromagnetic bearing bush friction combined transmission device, the influence of temperature on the magnetorheological fluid can be reduced, the transmission performance of the transmission device is improved, and the stability of torque transmission is ensured; and heat energy is fully converted and utilized, so that energy waste is reduced.

The invention relates to a magnetorheological-effect-based straight screwdriver with the positioning and anti-slipping functions. The magnetorheological-effect-based straight screwdriver with the positioning and anti-slipping functions is used for preventing the phenomenon that a bolt head is damaged due to the fact that relative slippage occurs between a screwdriver head and a bolt occurs when an operator overexert himself/herself to tighten or loosen the bolt through a screwdriver. The magnetorheological-effect-based straight screwdriver with the positioning and anti-slipping functions is composed of a shell, magnetorheological fluid, an isolation ring, an electromagnetic coil, a piston, a sealing ring, a piston rod, a cross bar, connecting rods, clamping rods, a straight screwdriver head, a size compensator, a sliding block, a button and a sliding groove. When the straight screwdriver head is stretched into a bolt head, a user slides the sliding block upwards to make the clamping rods clamp the bolt head tightly and then presses the button to power on the straight screwdriver, relative slippage will not be produced by the screwdriver head, the bolt head and the clamping rods when the screwdriver is rotated, and finally the bolt is tightened or loosened on the condition of guaranteeing that the bolt head is not scratched; the user presses the button again to power off the straight screwdriver and slides the sliding block downwards to make the clamping rods to loosen the bolt head, and then the whole bolt tightening or loosening process is completed.

The invention provides a magnetorheological polishing adhesive and a preparation method thereof. The magnetorheological polishing adhesive is composed of carbonyl iron powder (30%-70%), polishing powder (2%-7%), gel (0.5%-5%), gas-phase silicon dioxide (0.2%-1.5%), deionized water (10%-35%), and glycerol (15%-40%). The preparation method comprises the following steps: (1) weighing the carbonyl iron powder, the polishing powder, the gas-phase silicon dioxide, the gel, the deionized water and the glycerol according to a formula of the magnetorheological polishing adhesive; (2) putting the glycerol and the deionized water into a container, performing stirring to obtain a glycerol aqueous solution, performing heating, dissolving the gel into the glycerol aqueous solution under stirring to forma mixed solution; (3) adding the weighed carbonyl iron powder, the weighed gas-phase silicon dioxide, and the weighed polishing powder to the mixed solution in sequence, and performing stirring to obtain a magnetorheological polishing adhesive; and (4) putting the formed magnetorheological polishing adhesive into a refrigerating chamber, performing refrigeration, and taking the adhesive out whenusing. The magnetorheological polishing adhesive provided by the invention has the simple preparation method, higher stability and a higher shear yield stress, and can meet performance requirements ofprocessing.

The invention relates to a cylindrical roller thrust bearing having an integrated speed change function for a small load. The cylindrical roller thrust bearing is mainly used for adjusting the speed distribution condition of a mechanism operating in a period under the condition of the small load. The device comprises a shaft ring, a base ring, a rolling body, a holder, magnetorheological fluid, an electromagnetic coil, a separation ring, a piezoelectric ceramic and an insulation body. Two annular grooves are formed in the upper surface of the base ring; one annular groove is wound with the electromagnetic coil, and the other one is provided with the piezoelectric ceramic; the base ring and the piezoelectric ceramic are isolated by the insulation body; the shaft ring, the base ring and the separation ring are formed to a sealing cavity; the magnetorheological fluid is sealed in the sealing cavity, and is separated from the electromagnetic coil by the separation ring; a non-annular small boss is arranged on the lower surface of the shaft ring; the installation enables the small boss to periodically move in the annular groove provided with the piezoelectric ceramic; and a channel is formed between the electromagnetic coil and the piezoelectric ceramic for conducting the positive and negative poles of the piezoelectric ceramic with the two ends of the electromagnetic coil.

The invention relates to a self-aligning roller bearing with an integrated speed change function for a small load. The self-aligning roller bearing is mainly used for adjusting the speed distribution condition of a mechanism during operation in a cycle under the condition of the small load. The self-aligning roller bearing comprises an outer ring, a rolling body, a retaining rack, an inner ring, magnetorheological fluid, an isolating ring, an electromagnetic coil, piezoelectric ceramics and an insulator. Two annular grooves are formed in the internal wall of the outer ring, one annular groove is wound with the electromagnetic coil, the piezoelectric ceramics are mounted in the other annular groove, and the outer ring and the piezoelectric ceramics are isolated by the insulator; a sealed chamber is formed by the inner ring, the outer ring and the isolating ring, and the magnetorheological fluid is sealed in the sealed chamber and is isolated from the electromagnetic coil by the isolating ring; the external wall of the inner ring is provided with a non-annular small boss which is mounted in a manner that the small boss does periodic motion in the annular groove with the piezoelectric ceramics; a passage is formed between the electromagnetic coil and the piezoelectric ceramics and is used for enabling the positive and negative poles of the piezoelectric ceramics to be in conduction with the two ends of the electromagnetic coil.

The invention relates to a cylindrical roller bearing with an integrated speed change function for a small load. The cylindrical roller bearing is mainly used for adjusting the speed distribution condition of a mechanism during operation in a cycle under the condition of the small load. The cylindrical roller bearing comprises an outer ring, a rolling body, a retaining rack, an inner ring, magnetorheological fluid, an isolating ring, an electromagnetic coil, piezoelectric ceramics and an insulator. Two annular grooves are formed in the internal wall of the outer ring, one annular groove is wound with the electromagnetic coil, the piezoelectric ceramics are mounted in the other annular groove, and the outer ring and the piezoelectric ceramics are isolated by the insulator; a sealed chamber is formed by the inner ring, the outer ring and the isolating ring, and the magnetorheological fluid is sealed in the sealed chamber and is isolated from the electromagnetic coil by the isolating ring; the external wall of the inner ring is provided with a non-annular small boss which is mounted in a manner that the small boss does periodic motion in the annular groove with the piezoelectric ceramics; a passage is formed between the electromagnetic coil and the piezoelectric ceramics and is used for enabling the positive and negative poles of the piezoelectric ceramics to be in conduction with the two ends of the electromagnetic coil.

The present invention relates to a small load double row angular contact ball bearing with integrated speed change function. The bearing is mainly used to adjust the speed distribution of mechanism operation in one cycle in the case of small load. The apparatus includes an outer ring, a rolling element, a cage, an inner ring, a magnetorheological suspension, a spacer ring, a solenoid coil, a piezoelectric ceramic and an insulator. The inner wall of the outer ring is provided with two annular grooves; one annular groove is wound by the solenoid coil, and the other annular groove is provided with the piezoelectric ceramic; the insulator isolates the outer ring and the piezoelectric ceramic; the inner ring, outer ring and the spacer ring form a seal cavity for sealing the magnetorheological suspension therein; and the spacer ring isolates the magnetorheological suspension from the solenoid coil; outer wall of the inner ring is provided with a non-annular small projection; the small projection does periodic motion in the annular groove provided with the piezoelectric ceramic; and a channel is between the solenoid coil and the piezoelectric ceramic, and is used for conducing the positive and negative electrodes of the piezoelectric ceramic and two ends of the solenoid coil.

The invention belongs to the technical field of functional composite materials and relates to a preparation technology of a material with a shear thinning electromagnetorheological property. Comparedwith other single component materials, the prepared composite material of a core-shell structure by taking ferriferrous oxide as a core and molybdenum disulfide as a shell and modifying molybdenum disulfide with titanium dioxide has obviously excellent electrorheological and magnetorheological properties. The preparation method is simple in preparation process and convenient to operate; titanium dioxide and molybdenum disulfide have excellent electrorheological properties and can generate a relatively high shear yield stress under the action of an electric field, and meanwhile, magnetic ferriferrous oxide has a relatively high magnetizing saturated degree and can generate a relatively high shear yield stress under the action of a magnetic field. Molybdenum disulfide has an excellent lubricating property, so that the material is low in cost, clean and non-toxic and relatively short in reaction time, and has wide application value.