72 results about "Dumbbell shaped" patented technology

The invention discloses a natural ventilation cooling tower and a dumbbell-shaped concrete filled steel tube cross strut thereof, the dumbbell-shaped concrete filled steel tube cross strut comprises four dumbbell-shaped steel tube limb columns and cross nodes, and the end parts of the dumbbell-shaped steel tube limb columns are connected with the cross nodes to form a cross structure; the cross joint comprises a vertical stiffening plate, an upper reinforcing ring, a lower reinforcing ring, a plurality of joint sleeves and a plurality of joint webs, the upper reinforcing ring and the lower reinforcing ring are perpendicularly crossed with the vertical stiffening plate, the joint webs are connected with the joint sleeves, and the joint sleeves, the joint webs, the upper reinforcing ring and the lower reinforcing ring form a dumbbell-shaped structure with the vertical stiffening plate as the central axis. Open holes are formed in the reinforcing rings and used for pouring and circulation of concrete, the four dumbbell-shaped steel pipe limb columns are arranged at the open holes of the upper reinforcing ring and the lower reinforcing ring, and a closed space is formed by the joint sleeve, the joint web, the upper reinforcing ring, the lower reinforcing ring and the four dumbbell-shaped steel pipe limb columns. The problem of material waste caused by rich in-plane directional bearing capacity of a circular section can be solved.

The invention relates to the technical field of batteries, and discloses a battery cell cover plate assembly, a battery cell and a battery pack, the battery cell cover plate assembly comprises a cover plate body, a pole and a sealing ring; a mounting hole is formed in the cover plate body; the pole is inserted into the mounting hole, the pole comprises a first pole body, a second pole body and a bottom plate which are connected in sequence, the projection of the second pole body in the thickness direction is dumbbell-shaped, and the dumbbell-shaped projection comprises two linear sections and two arc sections; the sealing ring is arranged on the peripheral wall of the second column body in a sleeving manner and is clamped between the second column body and the cover plate body; the reserved gap between the arc section and the inner wall of the sealing ring in the length direction of the cover plate body is L1, the reserved gap between the linear section and the inner wall of the sealing ring in the width direction of the cover plate body is L2, and the L1 is larger than or equal to 0.01 mm and smaller than or equal to 0.1 mm, and the L2 is larger than or equal to 0.04 mm and smaller than or equal to 0.2 mm. According to the cover plate, the second column body is arranged to be the dumbbell-shaped section, the expansion amount of the linear section can be reduced, the sealing effect of the sealing ring is improved, and the deformation risk of the cover plate body is reduced.

The utility model relates to a multifunctional operation vehicle and a multifunctional garden vehicle. The multifunctional operation vehicle comprises a vehicle frame, an outdoor operation part and a front lamp assembly. The front lamp assembly comprises a left lamp part and a right lamp part which are connected with each other, a left illuminating lamp is arranged in the left lamp part, a right illuminating lamp is arranged in the right lamp part, and the whole front lamp assembly is of a dumbbell-shaped structure with a small middle part and two large ends. According to the embodiment, the left lamp part and the right lamp part are mutually connected and form a whole, the dumbbell-shaped structure is convenient to hold, a user can hold the small-size part in the middle of the front lamp assembly easily, especially in the production and assembly process, the sizes of the left lamp part and the right lamp part at the two ends of the front lamp assembly are slightly large, and the left lamp part and the right lamp part are not prone to being taken by one hand; the size of the middle position is small, holding is convenient, the assembling difficulty can be simplified, the assembling efficiency is improved, and the production cost is reduced.

1. Name of the product in this design: Plastic bottle (dumbbell shape). 2. Purpose of this design: To be used as a bottle for packaging beverages. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: a 3D model.

A staple driving tool that is dumbbell shaped having a first end, a second end, and a handle intermediate the first and second ends. The first end includes a staple receiving slot. The slot includes a concealed or recessed magnet to secure the staple within the slot for driving the staple into a support (i.e., a fence post). The second end has a flat surface for striking with a hammer to drive the staple into the post. The staple driving tool is generally symmetrical along a first axis, with the first and second end having a larger circumference than the handle. Alternatively, the staple receiving slot may be a cruciform slot. The cruciform slot has a first slot having a first length and a second slot having a second length, where the first slot is perpendicular to the second slot, and the first length is greater than the second length.

The eyelid massager 100 comprises: a handle 102 having a free end 104; and a roller 106 pivotally connected to the free end of the handle. The roller 106 is dumbbell-shaped, the curvature of the outer surface of the roller being matched to the curvature of the closed eye of the user such that during a massage action, the roller 106 comes into contact with the eyelid along the entire length of the eye to press a plurality of meibomian glands associated with the eyelid, promoting release of occluded grease. The handle 102 is Y-shaped 200 at the free end 104 to pivotally retain the roller 106 at both ends 204 by a pair of inwardly extending pins 202 that engage a pair of holes provided on the roller 106. The roller 106 is made of silicone rubber and a curved portion of the outer surface has a plurality of ribs 208.

An eyelid massager 100 includes a handle 102 having a free end 104, and a roller 106 pivotally coupled thereto. The roller 106 is dumbbell shaped having a curvature on an outer surface that matches curvature of a closed eye of the user, such that the roller 106 makes a contact with eyelids along an entire length of the eye during a massaging action, to press a plurality of meibomian glands associated with eyelids, facilitating release of clogged oils. The handle 102 is Y-shaped 200 at the free end 104 to pivotally hold the roller 106 at two ends 204 through a pair of inward extending pins 202 that engage with a pair of holes provided on the roller 106. The roller 106 is made of silicon rubber, and the curvature of the outer surface having a plurality of ribs 208.

The application discloses a novel assembled steel plate composite damping wall considering multistage stress and a design method, wherein the novel assembled steel plate composite damping wall is assembled by connecting steel plates, dumbbell-shaped weakened steel plates, force transmission steel plates welded with studs, concrete plates, L-shaped connecting angle steels and high-strength bolts. The novel assembled steel plate composite damping wall only bears the dumbbell-shaped weakened steel plates under normal use conditions and under small earthquakes, and the concrete plates provide out-of-plane constraints for the novel assembled steel plate composite damping wall; under medium earthquakes and large earthquakes, the external concrete plates start to bear loads, so that the assembled damping wall has sufficient rigidity and bearing capacity. The multistage stress characteristics can guarantee that the structure has good lateral resistance and bearing performance in different loading stages, fully play the mechanical performance of each component, and delay the damage of the structure under the action of earthquakes.

A baby bottle comprises a container 1 with a midsection that is narrower than the top and bottom of the container. The container may comprise at least one flat surface, and be narrow in at least one continuous plane or axis. The container may have a cross-section that is rectangular, oblong, tri-star shaped, cross-shaped, curved shaped, wavy shaped, breast-shaped or dumbbell shaped. The container may further comprise recesses, dimples, grips, bulges or printing on its surface, and may have feet or a wider stabilizing base. It also comprise a thermometer or temperature read-out display. This enables thermal heat energy and microwave energy waves to penetrate more easily and / or faster to the middle volume area of liquid or milk 7 contained therein in use.

The utility model relates to the technical field of metro construction, in particular to a supporting device for metro station construction, which is arranged in a metro foundation pit, and the foundation pit is in a dumbbell shape with two wide ends and a narrow middle part. Cast-in-place piles are vertically arranged on the inner wall of the foundation pit, steel supporting structures are vertically arranged on the inner sides of the cast-in-place piles, upper connecting plates are fixedly connected to the upper ends of the cast-in-place piles, an upper supporting beam stretching across the foundation pit is arranged in the middle of the foundation pit, and the two ends of the upper supporting beam are connected with the upper connecting plates on the two sides of the foundation pit. The two ends of the upper supporting oblique beam are connected with the upper connecting plates on the two adjacent sides of the foundation pit. Cast-in-place piles are vertically arranged on the inner wall of the foundation pit, upper connecting plates are fixedly connected to the upper ends of the cast-in-place piles, an upper supporting beam stretching across the foundation pit is arranged in the middle of the foundation pit, upper supporting oblique beams stretching across the foundation pit obliquely are arranged at the two ends of the foundation pit, and the upper supporting beam and the upper supporting oblique beams are connected with the cast-in-place piles through the upper connecting plates, so that the cast-in-place piles are connected with supports in the foundation pit. And the strength of the wall in the subway station is guaranteed.

The invention provides a fiber bragg grating sensor for multi-dimensional force measurement and a minimally invasive cardiac surgery tool head, and belongs to the technical field of fiber bragg grating sensing, and the fiber bragg grating sensor comprises a front integrated machined part which is cylindrical and is welded with a force sensitive element; the force sensitive element is of a cylindrical dumbbell-shaped hollow structure; the rear integrated processing part is cylindrical and is welded with the force sensitive element; and the four optical fibers are respectively engraved with customized Bragg gratings. The force sensing element can change the force measuring range, the force measuring precision and the force measuring sensitivity through carving optimization design, and can meet the force sensing requirements of wider minimally invasive surgical instruments.

The present application provides a controllable plate thickness and support to reduce the dumbbell-shaped pad block of hanging mold, including two groups of round cake pad block, and two groups of round cake pad block are fixedly connected into a dumbbell shape through steel bar, the manufacturing tool includes mold frame and auxiliary device, the mold frame and auxiliary device are installed in cooperation, the mold frame includes limiting plate, limiting groove, annular mold and bottom plate, the limiting plate is symmetrically fixedly connected on both sides of the bottom plate, the adjacent side of the two limiting plates is provided with limiting groove, the annular mold is fixedly connected on the upper end surface of the bottom plate, the auxiliary device includes square steel pipe, connecting piece and adjusting plate, the square steel pipe is fixedly connected with the adjusting plate through the connecting piece, the pad block of the present application can control the plate thickness, can support the hanging mold and keep the larger stable core, the pad block itself does not affect the floor quality, and the manufacturing tool of the pad block can freely manufacture the pad block of different thickness.

The present application relates to a kind of cable outer sheath dumbbell sample preparation method, first, the cable outer sheath of stripping is unfolded;Second step, the cable outer sheath in unfolded state is made to pass through cutter and cut off one side surface layer;Third step, the surface layer of the cable outer sheath in unfolded state in which one side surface layer is cut off is shaped on the side of surface layer cut-off, and the dumbbell-shaped cutout matching the dumbbell shape of cable outer sheath is formed, the depth of dumbbell-shaped cutout is above the thickness of cable outer sheath dumbbell;Fourth step, the cable outer sheath in unfolded state with dumbbell-shaped cutout is made to pass through cutter here and cut off sheath middle layer, the part of sheath middle layer located in the surrounding of dumbbell-shaped cutout is taken down, and the taken-down part is cable outer sheath dumbbell.The present application provides a kind of cable outer sheath dumbbell sample preparation machine which can be made into cable outer sheath dumbbell after forming cable outer sheath dumbbell, and provides a kind of new manufacturing method of cable outer sheath dumbbell.

The invention relates to an ultrasonic dumbbell strain state monitoring system and method for a scraper conveyor, and belongs to the technical field of intelligent mining of scraper conveyors. Due to the fact that the number of scrapper conveyor dumbbells is large and long-term high-load operation is achieved, manual inspection consumes time and labor, real-time monitoring cannot be achieved, and if dumbbell state faults cannot be found in time, normal operation of the scrapper conveyor is affected, and safety accidents are likely to be caused. According to the scraper conveyor ultrasonic dumbbell strain state monitoring system and method, the strong penetration characteristic of ultrasonic waves is utilized, the dumbbell shape change is reflected by measuring the length of a dumbbell, the measurement result is uploaded to a controller through a wireless base station, and the controller calculates dumbbell strain and analyzes whether the current dumbbell strain state is normal or not; when the dumbbell strain reaches a set alarm value, alarm prompt information is sent out, a maintainer is prompted to deal with the dumbbell in time, detailed information of the faulted dumbbell is uploaded to an underground centralized control system and a ground dispatching center, and dynamic real-time monitoring of the dumbbell state is achieved.

The present invention belongs to the field of building technology, and particularly relates to a flexible connection structure between a prefabricated infill wall and a prefabricated frame column. The technical solution is as follows: it comprises a prefabricated steel member I, a prefabricated steel member II and connecting steel bars, wherein the prefabricated steel member I is a square tube structure, fixedly arranged on the side of the prefabricated frame column, and provided with a vertical slide groove; the two ends of the prefabricated steel member II are dumbbell-shaped sliders and hooks respectively; one end of the connecting steel bar is embedded in the prefabricated infill wall, and the other end of the connecting steel bar is an O-shaped end; the slider is placed in the slide groove, and the hook hooks the O-shaped end to flexibly connect the prefabricated infill wall and the prefabricated frame column together. The present invention can solve the problem of the additional stress on the tie bars caused by the settlement deformation of the prefabricated infill wall, improve the local seismic performance of the structure, and has a simple structure, clear force transmission, good integrity, convenient construction, and safety and reliability.

The invention discloses a rock dynamic and static tension and compression multi-field coupling test method, and relates to the technical field of rock dynamic load, static load, tension and compression, shearing, rheology, temperature, seepage, chemistry, ultrasonic wave, acoustic emission, resistivity and other multi-field coupling tests. The sample is of a dumbbell-shaped structure with upper and lower end diameters larger than the middle diameter; the method comprises a triaxial axial tensile test, a triaxial compression test, a triaxial dynamic impact test, a dynamic and static triaxial multi-field coupling test at different temperatures and a true triaxial shear seepage coupling test. In the triaxial tensile test process, the end part of the test sample does not need to be glued, the test sample adopts a dumbbell-shaped test sample shape design, the axial tensile force is provided by using a confining pressure loading system and adopting confining pressure, and the axial tensile test of the rock under different confining pressure conditions can be realized.

The utility model discloses a dumbbell-shaped bearing platform concrete temperature control system and a dumbbell-shaped bearing platform. The dumbbell-shaped bearing platform concrete temperature control system comprises a plurality of cooling pipe layers in the transverse bridge direction, a plurality of cooling pipe layers in the longitudinal bridge direction and a plurality of temperature control monitoring nets used for monitoring the temperature in poured concrete in the bearing platform pouring forming process. And the plurality of transverse bridge direction cooling pipe layers and the plurality of longitudinal bridge direction cooling pipe layers are sequentially arranged at intervals in a staggered manner in the height direction of the bearing platform, so that poured concrete is layered by introduced cooling water, and the whole section of each layer is uniformly cooled. The multiple layers of temperature control monitoring nets are sequentially arranged at intervals in the height direction of the bearing platform so as to be used for layering the temperature in the poured concrete, and multi-measuring-point measurement is conducted on each layer. According to the novel temperature control system, uniform cooling of the internal temperature of the super-thick and super-large bearing platform concrete and effective control of the temperature difference of the internal surface of the large-size concrete can be achieved, temperature cracks caused by the fact that the temperature difference of the local internal surface of the bearing platform concrete is too high are reduced, and it is guaranteed that the dumbbell-shaped bearing platform is smoothly constructed and the construction quality is good.

The invention relates to a mechanical and thermal coupling loading solid propellant resistivity testing device and testing method, belongs to the technical field of resistivity testing, and solves the problem that the resistivity of a solid propellant cannot be accurately measured under the action of mechanical and thermal coupling in the prior art. The testing device comprises a vacuum chamber, a microscopic imaging assembly, a probe seat, a force and heat coupling loading device and an electric control three-dimensional displacement platform, the force and heat coupling loading device comprises a mechanical loading assembly and a temperature loading unit, and a closed thermal medium circulation loop formed by the temperature loading unit and a corrugated pipe is used for carrying out temperature loading on a dumbbell-shaped sample. The mechanical loading assembly is used for stretching the dumbbell-shaped sample, the probe seat is connected with a probe measuring point in the dumbbell-shaped sample through the probe extension copper wire, then the probe seat applies electrical excitation to the dumbbell-shaped sample, and finally test data for calculating the resistivity of the solid propellant is obtained through measurement. The influence trend of the temperature and deformation coupling effect on the resistivity of the solid propellant can be accurately tested, and the repeatability is high.

The present invention relates to a flatcon shell metal drum component having dumbbell shaped edges (100). The present invention also relates to an apparatus for manufacturing a flatcon shell metal drum component having dumbbell shaped edges (100) and a method for manufacturing a flatcon shell metal drum component having dumbbell shaped edges (100). The said flatcon shell metal drum component having dumbbell shaped edges (100) enables shipping of drum parts in dis-assembled condition and reassembling them at a location required, whereby solving the problem of shipping empty drums or barrels in bulk while saving huge shipping costs by optimizing effective use of transport space.

1. The name of the design product: graphite sintering platform (dumbbell shape). 2. The use of the design product: for loading raw materials for joule heat shock to prepare materials. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The invention discloses a multi-angle rotating ultra-high core wall dam gravel-doped clay tensile-fracture test device which comprises a mold assembly, two groups of adjusting assemblies and two groups of loading assemblies, a dumbbell-shaped cavity is formed in the mold assembly body and is used for preparing and bearing a test soil test piece; the two sets of adjusting assembly bodies are distributed on the two sides of the mold assembly body in a central symmetry mode, each adjusting assembly body comprises a rotatable semicircular disc and a semicircular disc track, the rotatable semicircular discs are coaxially embedded in the inner sides of the semicircular disc tracks, and the semicircular disc tracks are movably connected with the rotatable semicircular discs; and the end part of the mold assembly body is embedded into the inner side of the semicircular disc track and is detachably connected through a mold fixing bolt. The front loading assembly, the front assembly body, the rear loading assembly, the rear assembly body and the mold assembly body are used in cooperation, the operation process is convenient and rapid, the device can be suitable for a uniaxial tensile test, a tensile fracture test, a shear fracture test, a tension-shear fracture test and a compression-shear fracture test at the same time, and the application range is remarkably widened.

The utility model belongs to the field of automobile chassis parts, and provides a three-column structure off-road vehicle damping seat precision forging piece which comprises a body part and a connecting structure. Wherein the body part forms a columnar structure with a dumbbell-shaped cross section; the connecting structure comprises a first connecting column, a second connecting column and a third connecting column which are integrally forged and formed on the body part, and the height direction of the body part is perpendicular to the height direction of the first connecting column, the height direction of the second connecting column and the height direction of the third connecting column.

The application provides a foldable support plate, a flexible screen module and a foldable electronic device. The foldable support plate can be provided with a through groove, and a blind groove can be arranged near the foldable area. The shape of the through groove can be a dumbbell-shaped through groove. The base body of the foldable support plate can be composed of multiple materials. Different materials can correspond to different areas of the foldable support plate. The local plating layer on the foldable support plate can include a nickel sulfamate plating layer and a gold plating layer. An electroplating recess can be arranged in the area corresponding to the local plating layer. The scheme of the application is beneficial to taking into account the lightness, mechanical stability, electromagnetic performance, heat conductivity and the like of the foldable electronic device.

The invention belongs to the technical field of wind power tower drums, and particularly relates to an offshore wind power sectional type tower drum structure and method.The offshore wind power sectional type tower drum structure comprises a first tower drum and a second tower drum, a first cross frame is fixedly installed in the first tower drum, and a second cross frame is fixedly installed in the second tower drum; the first cross frame and the second cross frame are connected through arranged positioning columns and auxiliary positioning assemblies, the bottom of the first tower drum is connected with a plurality of reducing cylinders, the bottoms of the reducing cylinders are connected with hemispheres, and the reducing cylinders and the hemispheres are inserted into dumbbell-shaped grooves formed in the top of the second tower drum. A plurality of arc-shaped elastic metal sheets are fixedly arranged in the dumbbell-shaped groove in the circumferential direction at intervals, the diameter of a circle formed by the edges of the bottoms of the multiple arc-shaped elastic metal sheets is smaller than that of the hemisphere, and a limiting assembly is connected into one side of the hemisphere. And the overall rigidity of the butt joint part of the segmented tower drum is effectively improved.

The invention provides a stirring head and a method for preparing a functional matching composite structure through critical configuration, and particularly relates to the field of additive manufacturing of multi-layer composite structures. The stirring head sequentially comprises a sleeve and a dumbbell-shaped stirring needle, and the dumbbell-shaped stirring needle comprises a shaft shoulder, a dumbbell body small end, a dumbbell body conical rod and a dumbbell body large end which are sequentially and coaxially connected. According to the method, when the composite material is added, various parameters of a composite structure are designed according to needed functions and the performance of a plate, then a critical state is defined, the material adding sequence and the material adding process are formulated, a proper stirring head is selected according to the critical state, the process parameters of the stirring head are determined, and finally material adding treatment is conducted according to the requirements. According to the dumbbell-shaped stirring needle, an annular strong flow area is formed by a metal material during material adding, impact deformation occurs on interfaces on the premise that mutual mixing does not occur, the form complexity of the bonding interfaces is increased, the bonding strength of the bonding interfaces is effectively improved, and the connection strength is further improved.

The invention discloses an energy dissipation anti-seismic dual-function support for rectangular hardwood slotting and dumbbell-shaped mild steel plate clamping and embedding. The support is used for anti-seismic reinforcement of beam-column joints of a wood frame. The support is composed of two rectangular slotted hardwoods, a dumbbell-shaped mild steel plate, mild steel plate long holes, a yield energy dissipation section, a limiting structure, rectangular slotted hardwood glue joint fixing bamboo nails and steel plate pieces welded to the two ends of the dumbbell-shaped mild steel plate by 45 degrees. And the two slotted hardwoods are respectively embedded with half of the thickness of the dumbbell-shaped mild steel plate, then are bonded by latex and are fixed by bamboo nails. Bolt bars penetrate through the round holes in the two ends of the rectangular slotted hardwood and the corresponding long holes in the two ends of the dumbbell-shaped soft steel to form a hardwood round hole-soft steel plate long hole-bolt limiting structure. When the bolt bars slide in the long holes in the two ends of the dumbbell-shaped mild steel plate, the energy dissipation sections are yielded to dissipate energy, and when the bolt bars are limited in the long holes in the two ends of the dumbbell-shaped mild steel plate, the two slotted hardwoods are started through the screws to pull and press to resist shock. The support has the double functions that the mild steel plate dissipates energy under a large earthquake and the mild steel plate and the rectangular hardwood jointly resist earthquake under a huge earthquake.

This application provides a foldable support plate, a flexible display module, and a foldable electronic device. A through groove may be disposed in a foldable region of the foldable support plate, and a blind groove may be disposed near the foldable region. The through groove may be a dumbbell-shaped through groove. A base of the foldable support plate may be made of a plurality of materials. Different materials may correspond to different regions of the foldable support plate. Local plating of the foldable support plate may include nickel sulfamate plating and gold plating. An electroplated groove may be disposed in a region corresponding to the local plating. The solutions of this application help take into account lightweight, mechanical stability, electromagnetic performance, thermal conductivity, and the like of the foldable electronic device.

A non-pneumatic tire for a wheeled tower of an in-field irrigation system has a circular array of hollow cavities within the tire body. In cross-sectional planes lying normally of the rotational axis, each cavity has a circumferentially elongated cross-section of greater circumferential length than radial width. Bulbous and concavely rounded terminuses of each cavity impart a dumbbell shaped cavity profile that omits stress failure points. The cavity width tapers in an axially inward direction toward a midplane of the tire, where the cavity width is narrowest. In use, collapse of the cavity at its narrow midpoint squeezes accumulate mud out from the cavities in self-cleaning fashion. The outer circumference of the tire features sloped areas whose axial measure decreases toward the midplane. In use of the tire, the sloped areas draw mud inwardly toward the midplane and self-fill the ground beneath the tire, and thereby lessening overall rut formation.

A fluororesin composition contains a first fluororesin having a thermal history of having been heated to a melting point or higher and a second fluororesin having no thermal history of having been heated to a melting point or higher, in which the first fluororesin and the second fluororesin are non-melt-formable fluororesins, and in a case where a test piece is obtained by compression-molding the fluororesin composition to obtain a preliminary molded body and sintering the preliminary molded body at 380° C. for 2 hours or longer to be formed into a micro-dumbbell shape having a thickness of 0.5 mm and a size of 16 mm×45 mm, a metal elution amount with respect to a total mass of the test piece when the test piece is left to stand in 3.6% by mass hydrochloric acid at 23° C. for 24 hours is 5 ng / g or less.

The application discloses a dumbbell-shaped magnet structure and a magnetic resonance imaging system, and relates to the technical field of magnets. The first end magnet comprises at least one first magnet assembly, the first magnet assembly comprises at least two layers of first annular magnets which are sequentially sleeved; the middle magnet comprises at least one second magnet assembly, the second magnet assembly comprises at least one layer of second annular magnets, and the multiple layers of second annular magnets of each second magnet assembly are sequentially sleeved; the second end magnet comprises at least one third magnet assembly, and each third magnet assembly comprises at least two layers of third annular magnets which are sequentially sleeved; the number of layers of the first annular magnets of each first magnet assembly is more than the number of layers of the second annular magnets of each second magnet assembly, and the number of layers of the third annular magnets of each third magnet assembly is more than the number of layers of the second annular magnets of each second magnet assembly; and the magnet structure is in a dumbbell shape. The application can improve the uniformity of the magnetic field distribution and better meet the spatial requirements of the magnetic resonance imaging system imaging.