99results about How to "Increase thrust" patented technology

The invention relates to a cooling structure for an ultraprecise linear motor and belongs to the technical field of linear motors. The cooling structure solves the problem of proneness to heat exchange with environment caused by high side temperature of two-side surface-mounted cooling structures of existing linear motors. The cooling structure comprises a winding supporting portion, a winding and a heat conductive portion, wherein the winding is fixed on the surface of the winding supporting portion, the heat conductive portion is arranged on the surface on the outer side and fixedly connected with the winding supporting portion, the heat conductive portion is a copper foil ring which fits the outer profile of the winding and is sleeved and fixed on the surface on the outer side of the winding, or the heat conductive portion is a copper foil heat conductive ring formed by arraying multiple copper foil sections in a dispersed manner, the copper coil heat conductive ring fits the outer profile of the winding, and each copper coil section is fixed on the surface on the outer side of the winding. The cooling structure for the ultraprecise linear motor is suitable for cooling of linear motors.

According to the five-axis rotary table with the stacked brake pad structure, the effect of increasing the brake friction area is achieved through crossed stacking of the rotary brake pads and the static brake pads, and therefore the brake force of the five-axis rotary table is increased; meanwhile, high-pressure gas or liquid is input into the first containing cavity and the second containing cavity, so that the piston assembly moves upwards or downwards, the piston thrust is greatly improved, and the piston is doubly pushed to extrude the rotating brake pad and the static brake pad through the elastic force of an elastic body behind the piston and the thrust generated by pushing the piston through external air pressure or oil pressure; the extrusion friction force borne by the multiple rotary brake pads and the static brake pads is further increased, so that the five-axis rotary table has the quick-response brake performance and provides larger braking force, the whole five-axis machine tool can be self-locked and braked during transportation and power-off maintenance, the safety of equipment and personnel is guaranteed, and the service life of the five-axis machine tool is prolonged. And heavier parts and larger main shaft cutting torque can be borne during production and processing.

The invention discloses a multifunctional electric propulsion system of a spacecraft, and relates to the technical field of space propulsion systems. The multifunctional electric propulsion system comprises a gas cylinder module, a fluid management module and a thruster module. The downstream of the gas cylinder module is connected with the fluid management module; the downstream of the fluid management module is connected with the thruster module; the thruster module comprises a Hall thruster, an electric heating type thruster and a cold air thruster. The low-cost working medium gas is utilized, the attitude control system and the orbit control system of the satellite are integrated through modular design and heat flow design, the design and manufacturing difficulty of the satellite is lowered, the launching cost of the satellite is reduced, and meanwhile the integrated control system is combined with an orbit control algorithm, so that intelligent control over the satellite can be achieved.

The invention discloses a multistage self-adaptive enhanced mixing device for a solid fuel ramjet engine, which belongs to the technical field of solid fuel ramjet engines and comprises a front flange, a rear flange, an afterburning chamber barrel, a mixing partition plate, a heat insulating layer, a pressure measuring seat and a temperature measuring seat. The front flange and the rear flange are welded with the afterburning chamber barrel, a water pressure test is carried out after welding is completed, the mixing partition plates are bonded to the inner wall of the afterburning chamber barrel through high-temperature-resistant glue, and the mixing partition plates are distributed in a multi-stage mode, are separated through a heat insulation layer and are bonded through the high-temperature-resistant glue. In order to verify the effect of the multi-stage self-adaptive enhanced mixing device for the solid fuel ramjet engine, a pressure measuring point and a temperature measuring point are arranged on an afterburning chamber barrel and a mixing partition plate; according to the multi-stage self-adaptive enhanced mixing device, the combustion efficiency of a solid fuel ramjet can be remarkably improved, and the efficiency is further improved along with the increase of the number of the mixing partition plates.

The invention discloses two-way positioning automatic boring equipment, relates to the field of boring equipment, and solves the problem that the two ends of a workpiece are difficult to synchronously perform automatic positioning boring operation when the existing boring equipment is used, the two-way positioning automatic boring equipment comprises a machine body, a driving mechanism, a boring mechanism, an adjusting mechanism and two groups of cutter bars, the boring mechanism comprises a sliding seat, a mounting frame and a mounting block, and the adjusting mechanism comprises a first threaded rod. According to the two-way positioning automatic boring equipment, a workpiece is conveniently driven by the driving mechanism to rotate for boring operation, and the sliding seat is linked to slide in the guide frame in a reciprocating manner when the driving mechanism runs, so that the cutter bars on the two sides synchronously perform boring operation; the maximum displacement of the mounting block is preset through the adjusting mechanism, then when the sliding base slides in a reciprocating mode every time, the first threaded rod is linked to rotate by a set angle till the mounting block reaches the preset position, and the purpose of automatic positioning and reaming is achieved.

The invention discloses a bimorphic high-speed unmanned aerial vehicle capable of taking off and landing on the water surface and flying in ground effect and a control method, and belongs to the technical field of unmanned aerial vehicles, the bimorphic high-speed unmanned aerial vehicle comprises a vehicle body and a control device, the vehicle body is provided with an adjustable turbine jet driving mechanism and telescopic folding wings, and the tail of the vehicle body is provided with an empennage and a tail turbine jet driving mechanism. Meanwhile, the invention discloses a control method based on the two-form aircraft capable of taking off and landing on the water surface and flying in the ground effect, and the two-form high-speed unmanned aerial vehicle capable of taking off and landing on the water surface and flying in the ground effect and the control method are adopted. By adjusting the inclination angle, the distance and the height of the two front turbojet engines, operation and conversion of various forms of water sailing, ground running, ground effect flight and height flight are achieved, the use scenes of the unmanned aerial vehicle are greatly enriched, and the requirement for high-speed flight is met by adopting the telescopic folding wings.

The utility model discloses a ducted fan, which belongs to the technical field of aviation ducted fan engines, and comprises an annular duct, a plurality of blades and a plurality of blades, the fan blades are arranged in the annular duct, blade tip arc surfaces are arranged at the blade tips of the fan blades, and blowing gaps are formed in the sides, close to the suction surfaces, of the fan blades; the fan blades are fixedly connected to the outer side of the fan shaft; the driving part is used for driving the fan shaft to rotate, and the driving part is arranged on the rear side of the annular duct; the ratio of the height of the air blowing seam to the diameter of the arc surface of the blade tip is set to be 0.01-0.05; an air flow channel is formed in the fan blade and communicates with the air blowing seam. The number of the fan blades is two or more. The interior of the fan shaft is of a hollow structure. According to the utility model, the blade top clearance leakage flow is reduced by blowing at the top ends of the blades, so that the propulsion efficiency of the ducted fan is improved.

The conveying system comprises a conveying pipeline, a dredging and conveying assembly is installed on the conveying pipeline and comprises an installation groove formed in the conveying pipeline, the upper end and the lower end of the installation groove penetrate to the upper side and the lower side of the conveying pipeline respectively, a movable block is movably installed in the installation groove, and the movable block is connected with the conveying pipeline. A material conveying groove is formed in the movable block, a dredging unit is installed on the movable block, the inner diameter of the material conveying groove is the same as that of the material conveying pipeline, the material conveying groove is communicated with the material conveying pipeline, and the dredging unit comprises a through groove formed in the movable block; in the working process, the conveying groove and the through groove are formed in the movable block, during normal conveying, the conveying groove in the movable block is adjusted to be communicated with the conveying pipeline, and when material blockage occurs, the through groove in the movable block is adjusted to be communicated with the conveying pipeline, so that material conveying and blockage dredging are facilitated.

The invention relates to the technical field of cabinet monitoring, and discloses an intelligent emergency mobile communication cabinet monitoring device which comprises a monitoring camera, the top of the monitoring camera is rotationally connected with a rotating rod, the outer wall of the rotating rod is rotationally connected with a rotating frame, when the external wind speed is high, wind flow acts on fan blades, and the fan blades are driven to rotate by the rotating frame. The fan blades drive the driving wheel to rotate through the mounting frame and the supporting rod, the driving wheel drives the rotating rod to rotate through the transmission belt, the rotating rod drives the bevel gear and the first gear to rotate through the inclined gear ring, the first gear drives the shielding ring and the lens to rotate through the gear ring, and the gear ring drives the shielding ring and the lens to rotate anticlockwise. In the rotating process of the shielding ring, the friction force borne by the scraper is increased, the scraper scrapes and cleans the outer wall of the lens, and it is avoided that water drops are accumulated on the outer wall of the lens, and when a camera in the lens conducts monitoring, the recognition efficiency is affected due to imaging distortion.

The invention provides an engine simulation model modeling method and an engine simulation model. The modeling method comprises the following steps: calculating engine operation data according to aircraft state data and environment data; establishing a first sub-model for triggering an uncontrollable high-thrust fault according to the terrain clearance of the aircraft, wherein the first sub-model comprises a first fault injection module and a first engine module; and inputting the engine operation data, an output result of the first fault injection module and a preset output result of the first engine module into the first engine module for training to obtain a trained first sub-model. Faults can be injected through the fault injection module according to the terrain clearance of an aircraft, parameters such as engine thrust, rotating speed and exhaust temperature are rapidly and greatly increased compared with instruction values, and uncontrollable high-thrust faults of the engine are simulated.

The present invention relates to a novel self-cleaning ball valve, comprising a valve core, a valve body, a valve body base, a sealing packing, a valve stem, a valve cover and a hand wheel. The present invention cooperates with the valve core and the valve body base. When the ball valve is in a connected state, the flow of liquid is used to drive the inner wall of the valve core to rotate, thereby scraping off impurities attached to the inner wall of the valve core and causing them to be discharged along with the liquid. When the ball valve is closed, impurities in the static liquid are precipitated and gathered on the inner wall and surface of the valve core. When the ball valve needs to be connected, the hand wheel is rotated to drive the valve core to rotate. During the rotation process, the valve core is scraped by the valve body base, thereby cleaning impurities attached to the surface of the valve core and causing them to be discharged along with the liquid. Impurities on the inner wall of the valve core are discharged along with the power generated by the flow of liquid.

The utility model relates to the technical field of focusing electrode arrays, and particularly discloses a field emission thruster focusing electrode structure with a plume, which comprises an insulating bracket, an extraction electrode, a focusing electrode and an acceleration electrode, the insulating bracket is provided with a first connecting sheet, a second connecting sheet, a third connecting sheet and an assembling hole; the extraction electrode is configured to be fixedly connected with the first connecting sheet and is located in the assembly hole; the focusing electrode is fixedly connected with the second connecting sheet and is positioned in the assembly hole; the accelerating pole is fixedly connected with the third connecting piece and is positioned in the assembling hole; the central axes of the extraction electrode, the focusing electrode and the acceleration electrode coincide; the focusing electrode is positioned between the extraction electrode and the acceleration electrode; according to the focusing electrode structure of the field emission thruster with the charged plume, the focusing effect can be enhanced, the adverse effect caused by the plume is reduced, and the comprehensive performance of the thruster is improved.

The utility model relates to the technical field of glass cutting, in particular to a multi-cutter cutting device for glass cutting, which comprises a mounting cross beam, a plurality of cutter modules and a plurality of cutter modules, the movable cross beam is vertically arranged on the mounting cross beam in a sliding mode and is parallel to the mounting cross beam, an adjusting plate is arranged between every two adjacent groups of cutter modules, each adjusting plate is arranged on the movable cross beam in a sliding mode, each adjusting plate is provided with a wedge-shaped part, and the sizes of the two opposite side edges of each wedge-shaped part are gradually reduced from top to bottom; each wedge-shaped part is propped against two adjacent groups of cutter modules; the first cutter module in the multiple sets of cutter modules is a first cutter module, and the last cutter module in the multiple sets of cutter modules is a second cutter module. The first elastic piece is used for continuously providing pulling force for the first cutter module and the second cutter module to be close to each other. The device has the effects that the distance between every two adjacent cutter modules can be adjusted, manual adjustment is not needed, and the adjusting precision is improved.

The ship side thruster is provided with an arc-shaped bent pipe, a propeller is installed at one end of the arc-shaped bent pipe, the two ends of the arc-shaped bent pipe are open, the propeller is fixed into the arc-shaped bent pipe and connected with one end of a propeller shaft through a coupler support, the propeller shaft penetrates out of the arc-shaped bent pipe, and the propeller shaft is connected with the propeller shaft through a coupler support. A sealing assembly is arranged between the propeller shaft and the arc-shaped bent pipe, the propeller shaft penetrates through the sealing assembly and then is connected with a thrust bearing, the thrust bearing is fixed to an outer support, the propeller shaft can rotate under the supporting of the thrust bearing, the other end of the propeller shaft is connected with a turning transmission box through a flange, and the turning transmission box is connected with the propeller shaft. A sealing sleeve is arranged at the output end of the direction-changing transmission box, and the direction-changing transmission box is connected with a driving motor installed in the ship body. The resistance is reduced, and the service life is prolonged.

The utility model discloses an alloy in-mold pressure-maintaining thinning and cutting structure which comprises a mold main body, the mold main body comprises a plate A and a plate B, and a mold cavity is formed between the plate A and the plate B; the pressure maintaining assembly comprises a first oil cylinder and a groove formed in the plate B and used for containing materials, a pressure maintaining push rod matched with the groove in shape is arranged in the groove, and the groove is sealed by the pressure maintaining push rod; the in-mold cutting assembly comprises a second oil cylinder and a cutter, the cutter is located in the mold cavity, the output end of the second oil cylinder is connected with the cutter, and the cutter is used for cutting a product in the mold cavity; the extruding and thinning assembly comprises a third oil cylinder and an extruding and thinning push rod, a rod groove used for extruding and thinning the push rod is formed in the plate B, and the extruding and thinning push rod is matched with the rod groove in shape.

The steel moving machine comprises a main body mechanism, a lifting mechanism and a driving mechanism, and the main body mechanism comprises a rack; the lifting mechanism comprises two supports, a rotating rod and a plurality of pulling claws, the two supports are arranged on one side of the rack, the rotating rod is rotationally connected between the two supports, and the multiple pulling claws are sequentially arranged on the rotating rod at intervals in the length direction of the rotating rod; the steel moving machine has the beneficial effects that the machine frame of the main body mechanism and the support of the lifting mechanism provide stable support for the steel moving machine, it is guaranteed that shaking or inclination cannot occur in the steel moving process, and the steel moving machine is stable in operation, convenient to use and high in practicability. The electric-hydraulic push rod of the driving mechanism has high thrust and stability, acts on the middle portion of the rotating rod and can reliably push the rotating rod and the pulling claws to work, meanwhile, the multiple pulling claws are mainly used for stably moving steel billets to the next working procedure smoothly, the safety and reliability of steel moving are improved, and the production quality is improved.

The invention discloses a multi-channel fluid control electromagnetic valve structure, which belongs to the technical field of multi-way electromagnetic valves, and comprises a multi-way electromagnetic valve core, the multi-way electromagnetic valve core is composed of a pilot control sliding plug, a fluid control sliding plug and a fluid control column, and the fluid control column is provided with a fluid control unit used for detecting the movement fluency of the fluid control sliding plug. And impurities at the blocked part are cleaned. The fluid impurity cleaning mechanism carrying the butterfly type cleaning impeller is matched with the sliding plug blockage detection mechanism, when a blockage detection ring is extruded by adhered impurities to contract, a limiting magnetic ring can be driven to contract, control over the sliding plug blockage detection mechanism is relieved, the butterfly type cleaning impeller rotates and transversely moves, and the blockage detection efficiency is improved. The sliding path of the fluid control sliding plug is cleaned in time, internal flowing media are cut and removed through rotation of the butterfly type cleaning impeller, and when impurities are difficult to clean, a warning tone is given out to remind maintenance personnel.

The utility model relates to the technical field of pipeline cleaning, in particular to a deashing device and an exhaust pipe convenient for cleaning an exhaust passage of a single crystal furnace, which comprises a deashing piece, a scraping sleeve component and a driver, the driver is provided with a driving rod for mounting the deashing piece and the scraping sleeve component, and the driver drives the driving rod to drive the deashing piece and the scraping sleeve component to linearly reciprocate. The scraping sleeve assembly comprises a plurality of scraping sleeve pieces used for cleaning the ash removal pieces, and the ash removal pieces are provided with ash removal cavities allowing the scraping sleeve pieces to penetrate through in a reciprocating mode. According to the dust removal device, the driver drives the dust removal part and the scraping sleeve part to be telescopically matched for use, various dust, particles, fine substances or oily substances and other residual substances accumulated on the inner side wall of the exhaust pipe can be removed, and the dust removal part is cleaned through the scraping sleeve part after being scraped on the inner side wall of the exhaust pipe; the effects of automatic cleaning of the exhaust pipe wall and the self-cleaning function are achieved, the pipe wall is cleaned regularly and regularly, cleaning of the pipe wall can be completed without manual cleaning, the cleaning efficiency is improved, and the cleaning convenience is improved.

The present application belongs to the technical field of aviation turbofan engine control design, and specifically relates to a maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine, comprising: step one, obtaining the design state slip of each operating point at the right boundary of the envelope according to the engine flight envelope; step two, when the engine flight envelope enters the right boundary and reaches the maximum power state, based on the design state slip of the corresponding operating point, the slip is closed-loop controlled by adjusting the nozzle throat area; if one of the engine's high-pressure speed n2, low-pressure speed n1, and exhaust temperature T6 reaches the limit value, it is judged that the engine has reached the maximum power state.

The utility model provides an LED lamp bead and a display module, and the LED lamp bead comprises a light-emitting chip, a connecting column, a lamp base and a wire. The external threads arranged on the side wall of the periphery of the connecting column of the LED lamp bead can be matched with the mounting holes, with the internal threads, of the substrate or other mounting carriers, and compared with traditional welding connection, the threaded connection structure can remarkably improve the bonding strength between the LED lamp bead and the substrate or other mounting carriers. When the LED lamp bead is subjected to external vibration or impact, the threaded connection structure can provide larger pulling resistance through the threaded connection matching effect so as to enhance the thrust of the LED lamp bead, the service life of the LED lamp bead is effectively prolonged, and the working stability of the LED lamp bead is effectively improved.

The invention discloses an adjustable spray pipe suitable for a high-frequency time-varying flow field of a rotary detonation combined engine, and relates to the field of combined power engines. The spray pipe is composed of a spray pipe inner cone, a spray pipe outer cover, a spray pipe inner cylinder composed of a movable piece and a fixed piece, and an electric push rod. The structure is characterized in that an outer culvert flow channel is designed according to an outlet flow field of the rotary detonation engine and is matched with an annular rotary detonation engine combustion chamber, and high thrust is ensured. The spray pipe inner barrel movable piece serves as a movable plug cone of the plug type spray pipe and slides on the spray pipe inner barrel fixed piece through traction of the electric push rod, and the throat area of the outer culvert and the throat area of the inner culvert are adjusted. According to the design, the engine is allowed to use the inner culvert flow channel to exhaust in a low-altitude low-Mach-number turbine mode and use the outer culvert flow channel to exhaust in a high-altitude high-Mach-number rotating detonation stamping mode. By adjusting the elongation of the electric push rod, the pressure change of the working environment of the engine is matched, the work of the spray pipe is optimized, and the heat-work conversion efficiency of the rotary detonation stamping combined engine in a wide speed domain range is improved.

The invention relates to the technical field of laser machining, in particular to air conditioner accessory laser etching equipment which comprises a positioning table, a base and a laser, one end of an electromagnetic valve communicates with an air blower, the other end of the electromagnetic valve communicates with a first vacuum cavity, and the air blower is arranged on a body and used for blowing air into the first vacuum cavity to relieve the vacuum state of the first vacuum cavity; the flexible positioning pad is driven to rebound and reset, so that the product is pushed out of the bottom groove through the flexible positioning pad; according to the air conditioner accessory cutting device, the positioning groove used for containing a product is formed in the bottom groove through the flexible positioning pad, so that the edge of an air conditioner accessory is not prone to being collided and damaged, meanwhile, after cutting, the product in the bottom groove is pushed out through resilience of the flexible positioning pad, dismounting of the cut product is facilitated, and protection of the edge of the product is facilitated. The problem that an existing laser etching device easily causes damage to the edge of the air conditioner accessory is solved, and meanwhile the problem that the air conditioner accessory is inconvenient to disassemble after being cut is solved.

The invention discloses a marine empennage, which relates to the technical field of ships, and comprises a ship shell of a wave-shaped flat bottom structure, and the upper end of the ship shell is fixedly connected with a deck used for covering the space in a ship and horizontally dividing the space into layers; the side, close to a deck, of the hull is fixedly connected with a cabin used for storing materials and allowing sailors to work and live, the outer wall of the side, away from the cabin, of the hull is fixedly connected with an empennage plate body used for keeping course stability and providing rotation or trim adjusting capacity, and dynamic wingspan expansion mechanisms are arranged on the two sides of the upper end of the empennage plate body. An arc wing guide swing mechanism is arranged at the center of the upper end of the empennage plate body, a trapping screen wing mechanism is arranged on one side of the tail end of the empennage plate body, plate wings and an electric telescopic rod are matched with each other, and the stress area of the empennage can be increased by improving the sailing performance and expanding the wingspan; therefore, larger lift force is generated under the condition of the same wind speed or water flow.

The present invention discloses a sealed linear motor slide, which is composed of a sealed cavity composed of a slide rail, a steel belt, etc. The secondary design of the linear motor of the slide is modular, and a plurality of modular linear motor secondary screws are fixedly mounted on the bottom of the sealed cavity. There are an upper slide and a lower slide, and a slide raceway corresponding to the slide raceway. A plurality of steel balls are arranged between the slide raceway and the slide raceway for rolling, and they together provide rolling guide support for the slide. The upper slide is also designed with a breathing hole to improve the heat exchange efficiency between the linear motor in the sealed cavity and the external environment of the slide. The main structure of the lower slide is the primary part of the linear motor, and the lower slide is relatively independent of the upper slide. The lower slide is modular in design, and the number of windings of the lower slide can be changed to provide a fixed driving force to meet the different working conditions of the linear motor slide. Different lower slides can be shared with the same upper slide, so that only one upper slide with an optimal design length is needed to meet the different thrust requirements of the slide.

The utility model discloses a stamping mechanism for machining robot accessories, which comprises a base, a support frame is arranged on the base, a hydraulic cylinder is arranged on the support frame, a mounting plate is arranged at the output end of the hydraulic cylinder, a stamping die is arranged at the lower end of the mounting plate, a stamping seat is arranged on the base, mounting frames are arranged on two sides of the base, and the stamping seat is arranged on the mounting frame. A mounting frame is arranged on the base, a driving motor and a driving lead screw are arranged on the mounting frame, the driving motor is matched with the driving lead screw, a cleaning frame is arranged on the driving lead screw, a cleaning brush is arranged on the cleaning frame, an ejector rod is arranged on the base in a sliding connection mode, the ejector rod is matched with the punching base, a matching disc is arranged at the lower end of the ejector rod, and a matching column is arranged at the lower end of the matching disc. A matching block is arranged below the matching disc, the lower end of the matching block is rotationally connected with the inner wall, a slope table is arranged at the upper end of the matching block, and the slope table is matched with the matching column.

The invention belongs to the technical field of welding auxiliary equipment, and discloses a steel lattice beam submerged-arc welding jig frame device which comprises a bottom plate. A pair of symmetrically-arranged supporting plates is fixed to the bottom plate, and a horizontally-arranged rotating shaft is fixed between the two supporting plates. A square shaft is arranged above the two supporting plates, the central axis of the square shaft is perpendicular to the central axis of the rotating shaft, the two ends of the direction pipe are symmetrically arranged relative to the rotating shaft, the lower end face of the square shaft is fixedly connected with a hinge piece, the lower end of the hinge piece is rotationally arranged on the rotating shaft in a sleeving mode, and when the square shaft is horizontally arranged, the upper end face of the square shaft is parallel to the bottom plate. Supporting legs are fixed at two ends of the square shaft; the cross beam can be inclined by 45 degrees conveniently, the opening end of the included angle between the upper end face of the web and the wing plate located below the web is vertically placed upwards, enough space is reserved over the included angle between the web and the wing plate, a submerged-arc welding gun can directly face a splicing seam to conduct welding conveniently during welding, and therefore the welding quality and the construction efficiency are improved.

The invention provides a fan blade and a blower, and the fan blade comprises a base which is provided with a pivoting hole for a driving device to pass through and drive; the blades are arranged on the base and spirally extend from the center of the base; the blade is provided with a first edge connected with the base, the first edge is vertically arranged on the base and is close to the axis of the base, and the included angle between the extending direction of the first edge and the axial direction of the base is smaller than or equal to 80 degrees. Compared with the prior art, higher thrust can be output at a low rotating speed, noise can be reduced, meanwhile, the heat dissipation effect on the fan is enhanced, and the working efficiency is improved.

The utility model belongs to mobile equipment technical field discloses a linear motion platform, including bottom plate, first mobile platform and second mobile platform, first mobile platform is placed on the bottom plate, including first drive part and first platform, first drive part can drive first platform relative bottom plate moves along the first direction, second mobile platform is placed on the first platform, including second drive part and second platform, second drive part can drive second platform relative first platform moves along the second direction, first drive part and second drive part are linear bar -like motor, and the first direction and the second direction are perpendicular. The linear motion platform of the utility model not only high distance precision of moving but also can move fast and steadily, and still need not frequent maintenance simultaneously.

The utility model discloses a centrally-mounted VVT electromagnetic valve with a friction reduction structure, relates to the technical field of VVT electromagnetic valves, and is mainly used for solving the problems that a magnetism isolating sleeve and an armature of an existing centrally-mounted VVT electromagnetic valve are in sliding friction fit, and the surface contact part of the magnetism isolating sleeve and the armature is seriously abraded. According to the main structure, the electromagnetic coil comprises a front yoke, a coil assembly and a rear end cover which are coaxially connected in sequence, a magnetic isolation sleeve is installed in an inner cavity of the coil assembly, an armature is installed in the magnetic isolation sleeve in a sliding mode, and a plurality of steel balls which are arranged around the armature and can roll in the sliding direction of the armature are arranged between the armature and the magnetic isolation sleeve. According to the centrally-mounted VVT electromagnetic valve with the friction reduction structure, the friction force between the magnetism isolating sleeve and the armature is greatly reduced, the armature moves more smoothly, and meanwhile abrasion of the outer wall of the armature and the inner wall of the magnetism isolating sleeve can be reduced.

The invention provides a ducted thruster thrust testing device and testing method. The thrust testing device comprises an air duct type mounting base, an axial linear moving platform, a ducted fan, an air inlet pipe, an air outlet pipe, an auxiliary fan and a pull pressure sensor assembly. The ducted fan comprises a ducted shell and a core assembly, the core assembly comprises a supporting guide vane, an impeller and a motor assembly, a linear cylindrical guide rail assembly is arranged between the supporting guide vane and the ducted shell, and the thrust value of the core assembly can be independently measured through the arrangement of the linear cylindrical guide rail assembly. The thrust value of the core assembly is compared with the overall thrust value of the ducted fan, and the influence of the ducted shell on the thrust is evaluated; if the overall thrust value is larger than the thrust value of the core assembly, it is indicated that the thrust of the ducted shell is increased; if the overall thrust value is smaller than the thrust value of the core assembly, it shows that the duct shell causes energy loss.