30results about How to "Small frictional damping" patented technology

A quasi-zero stiffness vibration isolator with annular permanent magnets used for generating negative stiffness comprises a base and an outer cylinder connected with the base, the outer permanent magnet is arranged in a top notch of the outer cylinder, an upper cover is connected with the outer cylinder, a sliding bearing is combined with a central hole of the upper cover in a sleeved mode, and a central shaft is sleeved with the sliding bearing and is in clearance fit with the sliding bearing. A sleeve and an adjusting sleeve are sequentially connected to the position, located on the lower portion of the sliding bearing, of the central shaft, and the inner permanent magnet is installed in the sleeve. A spring is arranged at the bottom of the central shaft in a sleeving mode, the bottom end of the spring is fixed to the base, and the top end of the spring is fixed to the adjusting sleeve. A mark line on the central shaft is used for representing the position of the inner permanent magnet relative to the outer permanent magnet. When the mark line coincides with the upper end face of the sliding bearing, the inner permanent magnet exactly faces the outer permanent magnet, and the isolator is in a normal working state. The quasi-zero stiffness vibration isolator has the advantages of being high in static stiffness and low in dynamic stiffness, basic stimulation with large amplitude can be isolated, and the mass of a vibration-isolated objected can be adjusted.

The invention provides a two-degrees-of-freedom supporting system for a wind tunnel test of an airplane. The entire system comprises a rotating module (rotary table bearing for simulating pitching movement of the airplane), a translational module (linear guide rail for simulating plunging motion of the airplane), measuring modules (an angular displacement meter and a linear displacement meter formeasuring angular displacement and linear displacement), protecting modules (a disc brake and a shock absorber for limiting and protecting a test model) and an interface module (a shaft connected with the test model). The system is connected with an airplane module through a connecting module, and two degrees of freedom including pitching and plunging can be provided to simulate the flying pitching and plunging movement of the airplane; the angular displacement meter and the linear displacement meter can be used for measuring an attack angle and plunging displacement; a disc brake braking device can be used for limiting the pitching movement of the airplane model; and the shock absorber is used for limiting the plunging displacement of the airplane model and can be used for reducing an impact load, so that the test model is protected.

A pendulous eddy current tuned mass damper vibration reduction control device comprises a support and 1-4 mass blocks hung at the top end of the support through swing ropes, and an eddy current damping system and a guide mechanism are installed between each mass block and the support; each eddy current damping system comprises a permanent magnet and a conductor plate, the conductor plates are installed on the side faces of the mass blocks, and the permanent magnets are installed on the inner sides, corresponding to the conductor plates, of the support; the guide mechanisms are symmetrically installed on the two sides of the mass blocks in the swing direction, and each guide mechanism comprises guide plates fixedly installed on the two sides of the corresponding mass block and guide bearings installed on the inner sides of the support and making rolling contact with the corresponding guide plates. The support is provided with a pendulum length adjustment component and movable rolling wheels, the four corners of the pendulum length adjustment component are movably connected with the support, and a locking mechanism for fixing the swing ropes is arranged in a frame which is the pendulum length adjustment component. The control device is convenient to move in whole, frequency and damping coefficients are convenient to adjust, frictional damping is low, sensitivity of the mass blocks is high, the damping ratio of eddy currents can be freely adjusted within the range from 1% to 20%, and no additional rigidity is generated.

The invention discloses a novel self-lubricating material for a high-speed parallel robot. The novel self-lubricating material comprises the following components in parts by weight: 15-20 parts of molybdenum disulfide, 5-8 parts of fluoridized graphite, 3-7 parts of boron nitride, 2-5 parts of polytetrafluoroethylene, 55-85 parts of nylon, 10-15 parts of polyformaldehyde, 8-12 parts of ekonol and 4-6 parts of zinc-tin alloys. By adopting the mode, the novel self-lubricating material for the high-speed parallel robot, which is disclosed by the invention, has the advantages of the traditional self-lubricating material, and also has the advantages of less friction damping and larger operating temperature range, thus greatly prolonging the service life of the high-speed parallel robot and enlarging the application range of the high-speed parallel robot.

The invention discloses a pneumatically-driven type Stirling expansion engine which is used for a Stirling refrigerating machine. The pneumatically-driven type Stirling expansion engine comprises a base, a discharger component and a cold finger; a locating pin and a base air hole are arranged on and formed in the two sides in the base respectively; the discharger component comprises a pneumatic piston, a pneumatic air cylinder, a spring, a ball joint and a cool storage device; one end of the ball joint is connected with the pneumatic piston; the other end of the ball joint is connected with the cool storage device; one end of the spring is connected with the pneumatic air cylinder; the other end of the spring is connected with the pneumatic piston; a locating hole and an air cylinder air hole that are matched with the locating pin and the base air hole are formed in the two sides of the pneumatic air cylinder; and the cold finger is connected with the base and high pressure sealing is realized through a metal sealing ring. The reliability and the life of the refrigerating machine are improved and prolonged, and the requirements on the processing and assembly precision of parts are lowered.

A baffle-type one-way overspeed cut-off valve comprises a valve body, a valve cover, a valve plate, a glass window and a reset handle. The baffle-type one-way overspeed cut-off valve is characterized in that a corner bracket formed by a floorstand and a baseplate is arranged inside the valve body, a testing shifting fork is hinged on the floorstand, and two, three or four dry reed connection points are arranged on the floorstand. An adjustable plate hinged on the baseplate is supported on the testing shifting fork, positions corresponding to two dry reed connection points below the adjustable plate are respectively provided with a magnet, a tension spring screw rod mechanism is arranged between the adjustable plate and the baseplate, and the valve plate is fixed on the upper side of the adjustable plate. A reset rotating shaft is arranged on the end position of the oil outlet of the valve body, the reset handle is fixed at the shaft end of the reset rotating shaft outside the valve body, and a reset pusher dog is arranged on the reset rotating shaft inside the valve body. Two turning-over covers are arranged on the valve cover, and the valve cover and the two turning-over covers respectively form a wire connecting cabin and a detecting exhausting cabin independently. The baffle-type one-way overspeed cut-off valve has the advantages of being small in the setting error of flow velocity, strong in anti-seismic property, small in malfunction probability, good in sealing, long in service life and the like.

The invention discloses a suspension type vertical unfolding test device for a planar array antenna. The suspension type vertical unfolding test device comprises a truss bearing system, a gravity unloading system and an unfolding control system. The truss bearing system is used for providing gravity unloading system and unfolding control system installation interfaces. And the gravity unloading system is used for providing accurate gravity unloading in the vertical unfolding process of the planar array antenna. The unfolding control system is connected with the gravity unloading system to provide unfolding power for the planar array antenna and control the planar array antenna to be unfolded according to the unfolding speed required by a product. According to the invention, the problem that the satellite planar array antenna simulates the zero gravity condition of a space environment orbit in a ground gravity environment is solved; the defects of low gravity unloading precision, largedamping, poor safety and the like of a guide rail pulley follow-up type unfolding test device in the prior art are overcome; the device can be used for expansion test verification of the satellite planar array antenna under complex working conditions such as a thermal vacuum test chamber, and has the beneficial effects of high precision, small friction damping, simple structure, high safety and the like.

The invention provides a self-lubricating material for a joint robot and a preparation method thereof. The self-lubricating material is prepared from, by weight, 12-18 parts of iron powder, 3-8 partsof Al powder, 10-16 parts of copper sulfide powder, 6-11 parts of graphite, 1-6 parts of calcium hydroxide, 5-13 parts of nano molybdenum disulfide, 2-6 parts of silicon oxide, 2-8 parts of halloysitenanotubes and 12-18 parts paraffin. Compared with the prior art, the iron powder, the Al powder, the copper sulfide powder, the graphite, the calcium hydroxide, the nano molybdenum disulfide, the silicon oxide, the halloysite nanotubes and the paraffin are adopted as raw materials. Through interaction and mutual effects of all the components, the strength of the prepared self-lubricating materialis improved, friction damping is small, and the self-lubricating material is suitable for the joint robot.

The invention provides a high-precision angular limiting displacement vibration isolation buffering platform for photoelectric equipment. The vibration isolation buffering platform comprises an uppermounting plate and a lower mounting plate, wherein the upper mounting plate and the lower mounting plate are connected through a plurality of vibration isolators; photoelectric equipment is mounted onthe upper mounting plate, the lower mounting plate is connected with the mounting base, the plurality of corner limiting devices are symmetrically and uniformly mounted between the upper mounting plate and the lower mounting plate along the X-axis and Y-axis directions, the corner limiting devices limits the relative corner displacement of three coordinate axes of X, Y and Z generated when vibration impact occurs between the upper mounting plate and the lower mounting plate, ensured that the upper mounting plate and the lower mounting plate always do linear relative movement in three axial directions in the vibration impact process, and the three-axial linear displacement of the corner limiting devices are larger than the limits displacement of the third axial direction of the vibration isolators. According to the device disclosed by the invention, the photoelectric equipment is effectively isolated and buffered, the angular limiting displacement of the photoelectric equipment is effectively limited, and the accurate orientation precision of the photoelectric equipment is ensured.

The invention provides a magnetorheological torsion damper. A rear end cover and a front end cover are detachably connected with a shell; a winding rod is arranged on the shell; an electromagnetic coil is wound on the winding rod; distance sensors are installed on the rear end cover and the front end cover; preformed holes are formed in the middles of the rear end cover and the front end cover; acontroller and a power interface are fixed to the front end cover; an inner sleeve is installed between the rear end cover and the front end cover; bearings are installed between the inner sleeve andthe rear end cover and between the inner sleeve and the front end cover; a through hole is formed in the middle of the inner sleeve; a sealing cavity is defined by the inner sleeve, the rear end cover, the front end cover and the outer shell together; and magnetorheological fluid is filled in the sealing cavity. The magnetorheological fluid material is adopted, the friction damping of the torsiondamper is adjustable under different magnetic field intensities, the influence of the working temperature on the viscosity of the magnetorheological fluid is small, and the torsion damper works stably. The distance sensors are adopted to monitor the amplitude of a transmission shaft in real time, whether an electromagnetic coil is electrified or not is controlled through a controller, the currentis regulated and controlled through the controller, friction damping is controlled more accurately, and vibration of the transmission shaft is reduced.

The invention discloses a nonsymmetrical damping structure tensioning wheel bearing unit. The nonsymmetrical damping structure tensioning wheel bearing unit comprises a mandrel, a sleeve and a bearing; the sleeve is mounted on the mandrel, and the bearing is mounted on the sleeve; a spring damping structure is further mounted on the mandrel, and the spring damping structure comprises a first spring seat, a second spring seat and a rectangular spring which are combined together; and the rectangular spring is fixed with the first spring seat, the rectangular spring is in clearance fit with the second spring seat, a limiting groove partially extending in the circumferential direction is formed in a first side of the axial direction of the sleeve, a limiting boss inserted into the limiting groove is arranged at a second end of the axial direction of the second spring seat, and the circumferential length of the limiting groove is longer than that of the limiting boss. According to the nonsymmetrical damping structure tensioning wheel bearing unit, vibration in the operating process of a belt is reduced, the service life of the bearing and the belt is prolonged, and the noise in the speed changing process of an automobile is reduced.

The invention relates to an all-welded corrugated pipe type pressurizing oil tank adopting a non-contact sensor. The all-welded corrugated pipe type pressurizing oil tank adopting the non-contact sensor comprises an oil tank shell, a rear end cover, a corrugated pipe, a guide sleeve, a magnet, a non-contact displacement sensor and an inflation valve, wherein the corrugated pipe is connected with the rear end cover and the guide sleeve provided with the magnet in a welding manner so as to be arranged in the shell, so that a gas-liquid separation structure is formed jointly; the non-contact displacement sensor is installed on the outer side face of the oil tank shell; and the inflation valve and an oil inlet and outlet are located at the front end of the rear end cover and the front end of the shell respectively. According to the all-welded corrugated pipe type pressurizing oil tank adopting the non-contact sensor provided by the invention, due to the fact that the non-contact displacement sensor is adopted, on the basis that cost is reduced, a sealing device needed by a traditional contact displacement sensor is omitted, the structure of the oil tank is reduced, the weight of the oil tank is reduced, meanwhile, the leakage problem caused by long-time use of the sealing device is avoided, and the service life is prolonged, so that the all-welded corrugated pipe type pressurizing oil tank adopting the non-contact sensor is more economical and efficient; and the guide sleeve is in contact and clearance fit with the inner wall of the shell, so that friction damping generated when the corrugated pipe stretches out and draws back is reduced, and pressure compensation response is rapid.

The invention relates to an expansion-pipe-type automatic gap-adjusting piston mechanism. A ball head is fixed to an end of a working section of a pull rod, the pull rod is sleeved with an expansion pipe, the outer circumferential surface of the expansion pipe is sleeved with a spring, a piston is sleeved with the spring, an open end of the piston is in threaded connection with the outer surface of a blind nut, and the inner surface of a closed end of the piston is attached to the outer end face of a spring seat; an oil chamber is formed between the inner end face of the closed end of the piston and the outer end face of the spring seat, and the oil chamber communicates with an inner cavity of the piston through an oil through hole; and the space between the inner surface of an air cylinder seat of a lining and the outer surface of the piston is a stroke cavity of the piston, and oil inlets evenly distributed in the circumference of the lining communicate with the stroke cavity. According to the expansion-pipe-type automatic gap-adjusting piston mechanism, the expansion pipe is adopted for gap adjustment, stable expansion force is generated through plastic deformation of a pipe material of the expansion pipe, the defects that a spring sleeve is poor in friction force stability, and can generate stress relaxation after being used for a long time are overcome, the use reliability is high, moreover, the structural space is small, the weight is light, and the expansion-pipe-type automatic gap-adjusting piston mechanism is suitable for small and medium-sized brake machine wheels.

The invention relates to a ball bearing assembly for a satellite deployment mechanism. The invention aims to provide a ball bearing assembly for a satellite deployment mechanism, which can improve the reliability of the ball bearing assembly and meets the use requirements of the satellite deployment mechanism under the space environment. The ball bearing assembly is characterized in that the ball bearing assembly comprises the following parts, namely an outer ring, a middle ring and a spherical inner ring, wherein the outer surface of the outer ring is coated with a high-vacuum solid lubricating film and is connected with the deployment mechanism through a male hinge; and the outer surface of the spherical inner ring is coated with a high-vacuum solid lubricating film and is connected with the deployment mechanism through a female hinge. When the deployment mechanism moves, the outer ring and the middle ring or the middle ring and the spherical inner ring generate opposite rotation. The ball bearing assembly reduces the movement friction damping of the employment mechanism and improves the functional reliability of a bearing; and even if the failure happens between the spherical inner ring or the outer ring and the middle, the middle ring and the outer ring or the spherical inner ring still can keep the rotation function.

The invention discloses a maggot multiplying device used for ecological carassius auratus auratus cultivation. The maggot multiplying device comprises a box body, wherein the top of the box body is fixedly provided with a mesh enclosure; the outer wall of the top of the mesh enclosure is fixedly provided with a batch charging mechanism; the side wall of the mesh enclosure is fixedly provided withan inoculation mechanism; the inner wall of the mesh enclosure is fixedly provided with lugs which are distributed at equal intervals; the end surface of each lug is semi-circular; the cylindrical surface of each lug is provided with convex points; a humidification mechanism is fixedly inserted in the box body; one side of the box body is provided with an insertion hole; and an object placement mechanism is spliced in the insertion hole. According to the maggot multiplying device disclosed by the invention, a mating distance between two fly genitalia can be made up, mating quality is improved,and in addition, bulges on the lugs can rub with the fly genitalia to stimulate the flies to generate a mating signal.

The invention relates to a non-axialtorsion damping left and right steering tie rod assembly device comprising a tie rod and steering ball pins, wherein the steering ball pins are arranged at two sides of the tie rod; the opening surfaces of ball bowls on two ends of the tie rod are in parallel and the opening directions of the ball bowls are opposite; and the left end of the tie rod axially passes through the center of the steering ball pins. According to the non-axial torsion damping left and right steering tie rod assembly device disclosed by the invention, the frictional damping of the ball pins and the ball bowls inside the tie rod assembly is reduced, and the steering convenience and the steering reversal performance are improved.

The invention discloses a narrow lengthened high-walking parallelism beads and columns mixed linear guide rail. The liner guide rail comprises a guide rail(1) and a sliding block(2) matched with the guide rail(2), wherein the top surface of the guide rail(1) is a main moving surface for bearing positive pressure of a moving heavy-load object, a row of large rolling columns(3) is positioned on thetop surface of the guide rail(1), the two sides of the guide rail(1) are guide surfaces of bearing capacity, and two rows of rolling beads(4) are respectively positioned at the two sides of the guidesurfaces to restrain the deviation tendency of left, right and radial rotation of the moving object; the walking parallelism of the sliding block(2) and the guide rail(1) is 0.001-0.02mm, the length size of the sliding block(2) is 65-480mm, the width size of the sliding block(2) is 30-245mm, and two returning devices(5) are arranged at the left end and the right end of the sliding block(2). According to the linear guide rail, the interval between the sliding block and the guide rail is small through the controlling of the walking parallelism of the sliding block and the guide rail reference surface, so that the vibration of the linear guide rail is weakened, the frictional damping between the guide rail and the sliding block is reduced, and the motion precision of the linear guide rail isimproved.

The invention discloses a novel wind barrier structure utilizing vortex-induced vibration to capture energy, and particularly relates to the technical field of wind barriers, the novel wind barrier structure comprises a base and a wind barrier mounted on the base, mounting grooves are formed in the wind barrier at intervals, elastic plates are arranged in the mounting grooves, and an energy capture assembly is fixedly arranged at the top of each elastic plate; a vibration generator is installed at the bottom of the elastic plate, and a plurality of window assemblies are distributed on the wind barrier. The window assembly comprises a first window, a plurality of first silencing blades are arranged in the first window at intervals, and a movable first sliding rod is arranged at one end of each first silencing blade. By means of the energy capturing assembly, when crosswind on the outer side of the wind barrier is large, wind power generation is achieved, power can be supplied to electric equipment near the wind barrier area, in an urban area, the outside crosswind is small, the wind barrier can detect noise generated when different trains run through a noise sensor, and therefore the windward angles of a plurality of first silencing blades are adjusted, and noise reduction is achieved. And a sound barrier effect is realized.

The invention belongs to the field of pneumatic valves, and discloses a pneumatic servo valve with an air floating type sliding pair. The air floating type sliding pair is arranged in the pneumatic servo valve and comprises a valve element and a valve sleeve. The valve element is arranged in the valve sleeve. Air floating type valve shoulders are arranged at the two ends of the valve element and are in a cylindrical shape. Blind holes communicating with a center hole of the valve element are formed in the middles of the air floating type valve shoulders. A plurality of grooves communicating with the blind holes are formed in the air floating type valve shoulders in the circumferential direction. A static pressure bearing cavity is formed by each groove and the inner wall of the valve sleeve. When gas is introduced into the center hole of the valve element, the gas enters the static pressure bearing cavities, the pressure of the gas in the static pressure bearing cavities acts on the valve element, the valve element is suspended in the valve sleeve, and accordingly friction between the valve element and the inner wall of the valve sleeve during transverse movement is reduced. By means of the pneumatic servo valve, the problems that due to friction abrasion between a valve element sliding pair and a valve sleeve sliding pair of an existing pneumatic servo valve, the action sensitivity of a valve element is low, and the service life is short are solved, and meanwhile the control precision and dynamic response of the pneumatic servo valve are improved.