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

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 provides a thimble type micro-impulse applying device. The thimble type micro-impulse applying device comprises a center pole taking a vertical placing position as a balancing position;two thimbles symmetrically distributed by taking the center pole as an axis, wherein each thimble has a needle point; a switching structure for fixedly connecting the center pole with two thimbles; animpact part arranged at a lower part of the center pole; two bearing seats with pit curved surfaces, wherein two thimbles are placed on the bearing seats, the needle points of the thimbles are contacted with the pit curved surfaces; a bracket for horizontally placing two bearing seats, wherein two contact points of the needle points of the thimbles and the pit curved surfaces of the bearing seatscan be connected to form a horizontal line; the center of gravity of the center pole and the whole structure driven to swing by the center pole is lower than the horizontal line, the center pole canswing by taking the horizontal line as the rotating shaft, the contact area is small, and an aim of reducing the friction damping is realized. A balancing weight can rotatably change the height position on the center pole through thread matching, thereby changing the position located by the center of the gravity of the swing structure.

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 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 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.