10241 results about "Magnet" patented technology

The invention provides a permanent magnet motor and a scroll inverter compressor, and relates to the technical field of scroll compressor design and manufacturing, and the permanent magnet motor comprises a stator iron core and a rotor iron core; the stator core comprises stator teeth and a stator yoke which are uniformly distributed along the circumference, fluid through grooves are formed in the outer side of the stator yoke at the tops of the stator teeth, stator grooves are formed in two adjacent stator teeth and the stator yoke between the two stator teeth, and a plurality of strands of conductive circular enameled wires are embedded in each stator groove; the outer side of the rotor core is composed of linear segments and arcs, air grooves which are evenly distributed are formed in the rotor core, non-uniform magnetic isolation bridges are formed between the air grooves and the linear segments on the outer side of the rotor core, a certain distance is formed between every two adjacent air grooves, parallel magnetic conductive ribs are formed, and permanent magnets with the magnetic field directions changing alternately are embedded in the air grooves. A rivet hole, a lightening hole and a shaft hole are arranged close to the inner side of the rotor core. Therefore, the defined proportionality coefficient Ks is kept in a reasonable range, the power density of the motor can be increased, the cost is reduced, and the efficiency is improved.

The invention discloses a steel pipe polishing equipment, which comprises a steel pipe polishing equipment body. A main valve of a polishing motor is arranged in the main body of the steel pipe polishing equipment; a polishing handle is arranged on the main valve of the polishing motor; The valve is provided with a rotating roller; the front end of the rotating roller is provided with polishing bristles; one side of the rotating roller is provided with an outer throwing roller; a clamping spring is arranged between the outer throwing roller and the rotating roller; The outer throwing roller is provided with an outer throwing brush; a symmetrical magnet is arranged between the outer throwing brush and the polishing bristles; a polishing wheel is arranged on the outer throwing brush and the polishing bristles; the polishing The grinding wheels are arranged in a figure-eight shape. Its structure is simple, easy to use, and easy to operate. It can realize the polishing of the outer surface and the inner wall. The polishing is fast and uniform, with high efficiency and convenient use.

The invention provides a chemical restoration method for treating heavy metal-polluted terrain soil by ferromagnetic artificial nucleuses. In a ferromagnetic artificial nucleus soil restoration method, the ferromagnetic artificial nucleuses are applied to heavy metal-polluted soil; soil above a heavy metal pollution depth is overturned by cultivation equipment to uniformly mix with the ferromagnetic artificial nucleuses; and after heavy metal can be dispersed from the soil to the artificial nucleuses by a period of time, the soil containing the artificial nucleuses is overturned by using the cultivation equipment to increase the change of the artificial nucleuses contacting with other soil. After the soil overturning procedure is repeated by multiple times, the cultivation equipment provided with magnets can be used for separating the ferromagnetic artificial nucleuses, absorbed with the heavy metal, from the polluted soil; and the content of the heavy metal of the polluted soil is reduced due to shifting-out of the ferromagnetic artificial nucleuses, so that the purpose of soil restoration is gradually achieved.

The invention provides a multi-objective optimization method for non-planar coils of a star simulator and a star simulator magnet. The optimization method comprises the following steps: obtaining initial structures of a plurality of non-planar superconducting coils according to magnetic field configuration data of target plasma; according to the target magnetic field parameter, the engineering constraint parameter and the material constraint parameter of the configuration data, an objective function is constructed, the engineering constraint parameter comprises the engineering limit geometric parameter of the non-planar superconducting coil, and the material constraint parameter comprises the limit current carrying of the non-planar superconducting coil material; carrying out minimization solution on the target function to obtain optimized coil data; and performing materialization processing on the plurality of non-planar superconducting coils according to the optimized coil data to obtain a plurality of optimized non-planar superconducting coil models. According to the optimization method, a magnetic field matching-engineering feasibility-material safety three-dimensional constraint system is constructed, and the problem that the engineering cannot be realized on the ground is avoided.

A holder is configured to be detachably secured to an electronic device which includes a first magnetic attraction member. The holder includes a case and a second magnetic attraction member mounted to the case. The second magnetic attraction member is configured to be attracted to the first magnetic attraction member in a first direction. The second magnetic attraction member includes a first magnet layer extending along a circumferential direction; and a second magnet layer disposed around the first magnet layer in the circumferential direction, the first magnet layer and the second magnet layer being separately formed. The first magnet layer and the second magnet layer are polarized in an axial direction which is parallel to the first direction and perpendicular to the circumferential direction, and polarization directions of the first magnet layer and the second magnet layer are opposite to each other.

The technology described herein is directed towards a transceiver with beam scanning capability based on leaky wave antenna technology and substrate integrated waveguide technology, along with a metallic covering that determines which direction the antenna radiates signals. The leaky wave antenna can include different respective groups of slot pairs having different respective periodicities, corresponding to different respective beam steering directions. One or more metallic covers can be used to cover some of the slot pair sections, such that the sections under cover behave like a conventional substrate integrated waveguide and the exposed section(s) behave like conventional leaky wave antennas. The metallic covers can be moved as desired, such as attached via magnets. The transceiver can thus steer signals to a wearable or portable device that includes a passive metasurface while mitigating null regions. The slot pairs can be asymmetrical reflection-canceling slot pairs, to achieve broadside radiation while avoiding band-stop effects.

The present invention discloses a portable hand warmer having a magnetic attraction function, comprising two sets of face shells and two sets of bottom shells, the face shells being mounted on the bottom shells, wherein heating sheets are mounted on the face shells, arc-shaped heat-conducting hardware shells are mounted on the heating sheets, and the arc-shaped heat-conducting hardware shells are connected to the face shells; top portions and bottom portions of inner walls of the bottom shells are provided with magnet positioning cavities, and magnets are mounted inside the magnet positioning cavities; and batteries are mounted at middle ends of inner cavities of the bottom shells, PCBA boards are mounted at head portions of the inner cavities of the bottom shells, and the PCBA boards are electrically connected to the batteries and the heating sheets. The present invention has the advantage of being convenient to use.

An electric motor having a stator and a rotor in which the electric motor is an axial flux motor. The stator has a multiplicity of cores which, along a circumferential direction, are disposed beside on another on a common first diameter and are in each case surrounded by one coil. The rotor has a multiplicity of magnets which, along the circumferential direction, are disposed beside one another on a common second diameter on a support. Each magnet in the circumferential direction extends across a first angular range and the magnets are disposed so as to be mutually spaced apart by a second angular range formed by the support, which support is also heatable by the stator by induction. The second angular range is at least 30% of the first angular range.

The invention discloses a wireless and passive carrier roller monitoring device and a using method thereof, and belongs to the technical field of online monitoring, the wireless and passive carrier roller monitoring device comprises a stator assembly fixedly arranged on the outer side of a carrier roller shaft in a sleeving mode and a rotor assembly fixed in a bearing seat of a carrier roller uterus body, an annular or semi-annular circuit board is arranged in the stator assembly, a sensor module, an inductance coil and a wireless transmission module are arranged on the circuit board, and permanent magnets are evenly arranged on the side, close to the carrier roller uterus body, of the rotor assembly. According to the stator and rotor separation type structural design, the monitoring device and a carrier roller mechanical structure are deeply fused, direct capture of energy of a rotating part and stable acquisition of signals of a static part are achieved, the problems of power supply and wiring on a rotating body in a traditional monitoring scheme are solved, and the system integration degree and reliability are improved.

The invention discloses a motor position non-contact sensing system and a signal processing control method. The system comprises a three-dimensional magnet assembly, a magnetic signal acquisition module, a digital signal processing unit, a voltage conversion unit and a cooperative control module. The three-dimensional magnet assembly and the acquisition module are coaxially arranged, magnetic points are in spatial gradient layout, the acquisition module comprises a three-dimensional magnetic field detection unit, a real-time phase calibration unit is arranged in the processing unit, and the cooperative control module adjusts sampling parameters based on the rotating speed. The method comprises the steps of initialization, magnetic signal acquisition, operation processing and voltage conversion output. According to the scheme, the problem of magnetic field signal distortion of an existing system is solved, stable and accurate sensing of the motor position is achieved, and the multi-scene motor control requirement is met.

The invention discloses an integrated tile-shaped magnet outer circle grinding device and method based on artificial intelligence, and belongs to the technical field of grinding machining. The integrated tile-shaped magnet outer circle grinding device comprises a feeding device, a grinding device and a visual detection device; the feeding device comprises a feeding conveying belt, a guide groove, a spring bin, a material blocking barrel, a feeding barrel, a magnetic suction cup, an electromagnetic push rod, a cooperative mechanical arm, a reset spring and a discharging conveying belt. The visual detection device comprises a magnetic shoe counting camera, an annular light source, a counting camera bracket, a measuring camera bracket, a backlight plate, an outer contour measuring camera, a positioning camera and a positioning camera bracket; integrated automatic operation of feeding, grinding, detection and discharging is achieved, the production efficiency is greatly improved, automatic counting, precision detection and discharging are completed through cooperation of visual detection and the conveying belt, the manual operation intensity is effectively reduced, production interruption caused by personal errors is avoided, and the productivity in unit time is remarkably improved.

The invention discloses a stator and rotor punching sheet and magnetic steel for a concentrated winding type frameless torque motor, and belongs to the technical field of concentrated winding type motors, the stator and rotor punching sheet comprises a rotor punching sheet, a stator punching sheet and magnetic steel, and the center of the rotor punching sheet is provided with a rotor iron core; the stator punching sheet is composed of yoke parts and tooth parts, the tooth parts are trapezoidal teeth, the tooth parts and the stator grooves are distributed at equal angles, the tooth parts and the stator grooves are alternately arranged, and the stator grooves are straight grooves; the inner side of the stator punching sheet is also provided with a rotor punching sheet and magnetic steel, the rotor punching sheet and the magnetic steel form a motor rotor, and the motor rotor is a surface-mounted rotor. According to the stator and rotor punching sheet and the magnetic steel for the concentrated winding type frameless torque motor, the winding grooves of the stator iron core are flat-bottom straight grooves, the flat copper wires are wound in the winding grooves, the flat wire coils are fixed to the tooth portions through glue, integral potting is carried out after fixing is completed, and compared with a traditional pear-shaped groove for containing round wire windings, the stator and rotor punching sheet is simple and firm in structure, high in groove fullness rate, high in motor efficiency and improved in stability.

The invention discloses a three-dimensional magnetic field bionic seal beard sensor based on a Hall effect. The sensor comprises a mounting frame, a Hall chip, a universal joint component, bionic beards and magnets, wherein the Hall chip and the universal joint component are arranged on the mounting frame; the bionic beards are arranged on the universal joint component; the universal joint component is used for enabling the bionic beard to swing in a first direction and a second direction in a reference plane perpendicular to the center line of the bionic beard after the bionic beard is subjected to the acting force of fluid, the first direction is perpendicular to the second direction, and the universal joint component enables the bionic beard to reset after the bionic beard is not subjected to the acting force of the fluid; the magnetic flux density of the magnets changes along with the movement of the bionic beards; the Hall chip is used for sensing magnetic field information. While the characteristics of strong environmental adaptability and high sensitivity of a conventional bionic beard sensor are reserved, the limitation of one-way sensing of the sensor is broken through, the synchronous detection capability of the flow velocity, the flow direction and the vortex street frequency is improved, and the application range of the sensor in a complex underwater scene is widened.

The application provides a permanent magnet eddy current governor for constant torque load heavy load starting and a control method thereof, and belongs to the technical field of permanent magnet eddy current transmission speed regulation. The permanent magnet eddy current governor comprises a conductor cylinder, a magnet disc, a transmission shaft and a magnet disc axial traction mechanism. The conductor cylinder is connected with a motor input shaft, the inner wall of the conductor cylinder is fixed with two groups of annular conductor sleeves, the annular conductor sleeves are divided into starting zones and rated working zones in the axial direction, and the two groups of starting zones are separated by an idle zone. The transmission shaft passes through the rear end of the conductor cylinder, the front end is located in the conductor cylinder, and the rear end is connected with a load output shaft. The magnet disc is installed on the shaft rod of the transmission shaft located in the conductor cylinder, and the outer ring surface of the magnet disc is uniformly distributed with permanent magnets. The magnet disc axial traction mechanism is used for driving two magnet discs to synchronously approach or move away from the center of the idle zone. The application can be used for motor idle starting, heavy load controllable starting, load balancing, speed regulation operation and unloading overload protection of constant torque load.

The present invention belongs to the technical field of parameter identification for permanent-magnet synchronous motors. Disclosed are a parameter identification method and apparatus for a permanent-magnet synchronous motor, and a storage medium and a device. The method comprises: using a variable step-size feedback neural network algorithm to solve a voltage equation and a d-q axis current discrete state equation, which take cross-coupled inductance into consideration, of a permanent-magnet synchronous motor in a dq coordinate system, so as to obtain intermediate parameters generated in the process of constructing the d-q axis current discrete state equation; and performing calculation on the basis of the intermediate parameters, so as to obtain the stator resistance, the d-axis inductance, the q-axis inductance, the cross-coupled inductance and the permanent-magnet flux linkage of the permanent-magnet synchronous motor, and thereby completing parameter identification. The present invention takes cross-coupled inductance into consideration and uses the variable step-size feedback neural network algorithm, such that the computational load is extremely small, the degree of complexity is reduced, rapid and effective identification can be realized, and errors can be reduced; in different convergence time periods, the algorithm adjusts the step size on the basis of the magnitude of steady-state errors, such that identification results approach stable values more quickly, thereby improving the speed and stability of convergence.

The invention belongs to the technical field of geotechnical engineering drilling, and particularly relates to an instant pipe-following anti-falling object device for broken stratum drilling, which comprises a drilling machine power head and a drilling rod, a drill bit is arranged at one end of the drilling rod, an inner wall protection sleeve is arranged outside the drilling rod, and the inner wall protection sleeve is connected with the drilling machine power head through a linkage assembly. An outer wall protection sleeve is arranged outside the inner wall protection sleeve, the outer wall protection sleeve and the inner wall protection sleeve are connected through an elastic assembly, a sliding fit clearance cavity is formed between the outer wall protection sleeve and the inner wall protection sleeve, and a sliding guide assembly and a permanent magnet assembly are arranged in the sliding fit clearance cavity; a sensing assembly and a propelling assembly are arranged on the drill rod; according to the device, by integrating the linkage assembly, the elastic assembly, the permanent magnet assembly and the central controller, instant synchronous movement of the wall protection sleeve and the drill bit is achieved, hole wall collapsing objects are effectively blocked, drill burying and drill jamming accidents are completely eradicated, and the construction efficiency is improved.

The invention provides an easy-to-scale efficient biological magnetic separation system and method and application. The magnetic separation method comprises the following steps: marking a target object in a to-be-detected suspension by adopting magnetic nanoparticles, and putting the marked to-be-detected suspension into a separation container; a modularized magnet array is arranged in the separation container, the modularized magnet array is composed of permanent magnets, and the permanent magnets are assembled into the cuboid modularized magnet array; the surface of the permanent magnet is coated with a polytetrafluoroethylene coating; the modularized magnet array moves in the suspension under the control of a driving magnet arranged outside the separation container to generate a dynamic gradient magnetic field, and a target object is captured by the modularized magnet array under the action of the gradient force of the magnetic field; removing the liquid in the separation container; adding the resuspension into a separation container, and recovering a target object by physical ultrasonic washing; or adding a chemical dissociation solution into the separation container to recover the target object.

A closure device includes a first magnet and a housing with a second magnet positioned therein. The first magnet is configured to be position in a first object and the housing is configured to be positioned in a second object. The housing has a top end and at least one adjustment mechanism connected to the housing that moves the second magnet in at least one translational direction or at least one rotational direction relative to the top end of the housing. The movement of the second magnet relative to the top end of the housing adjusts the position or orientation of the second magnet relative to the first magnet to alter a magnetic force between the first magnet and the second magnet when the first magnet is positioned proximate the top end of the housing.

The invention relates to the technical field of gear boxes, and discloses an efficient heat dissipation gear box with a built-in magnetic fluid cooling channel, which comprises a reduction gear box, an input shaft, an output shaft, a transmission gear and a planet carrier, the magnetofluid cooling assembly comprises an annular cooling pipe filled with magnetofluid, a radiator and two sets of connecting frames, the cooling pipe is partially arranged in the reduction gear box, and the other part of the cooling pipe penetrates through the reduction gear box and extends to the outside. The radiator is fixedly arranged on the outer side of the reduction gear box to radiate the other part of the cooling pipe, the connecting frame is in transmission connection with the input shaft or the output shaft, and a permanent magnet is fixedly arranged at the outer end of the connecting frame. By means of the built-in magnetofluid cooling assembly, the permanent magnet is driven to rotate by means of the input shaft or the output shaft, magnetofluid is driven to circularly absorb heat and radiate heat through the radiator, extra power is not needed, heat transfer is fast, and no cooling dead angle exists.

In some embodiments, an apparatus includes a holder including a first surface, a second surface, a body portion in between the first surface and the second surface, and a protrusion. The first surface is configured to be coupled to a mounting surface. A magnet is disposed within the body such that a portion of the second surface is magnetically attractable to a first portion of an article. The protrusion is configured to engage a second portion of the article. The article being removably coupled to the holder when the first portion of the article is magnetically coupled against the portion of the second surface and the second portion of the article is engaged with the protrusion.

The invention discloses a variable magnetic flux memory motor, which comprises a stator, armature windings and a rotor, and is characterized in that the armature windings comprise a first winding and a second winding which are different and switchable in mode; the rotor comprises a plurality of poles distributed in the circumferential direction, each pole comprises a first layer of permanent magnets and a second layer of permanent magnets, the first layer of permanent magnets are high-coercive-force permanent magnets, the second layer of permanent magnets comprise at least two second permanent magnets, all the second permanent magnets are high-coercive-force permanent magnets or all the second permanent magnets are low-coercive-force permanent magnets, and the first layer of permanent magnets and the second layer of permanent magnets are arranged in the circumferential direction. And the characteristics of the magnetic materials of the second layer of permanent magnets of two adjacent poles are opposite, a fundamental wave main magnetic field is formed through the first winding in a magnetism increasing state so as to improve the permanent magnet torque, and the second winding is switched to excite a harmonic magnetic field in a magnetism weakening state so as to maintain torque output. According to the invention, through the collaborative design of the heteropole asymmetric permanent magnet layout and the dual-mode winding, the problems that the magnetic adjustment range of the existing variable flux memory motor is limited and the torque is suddenly reduced in a weak magnetic state are solved, and the efficient operation interval is obviously widened.

A foreign matter removal device may include a chamber comprising a fluid, and a magnet assembly under the chamber. The chamber may include a loading section configured to load a first object, a second object, and a third object into the fluid, a first trap region configured to trap the first object, a second trap region configured to trap the second object and to be adjacent to the first trap region, and a third trap region configured to trap the third object and to be adjacent to the second trap region. The first object is a first foreign matter, the second object is a semiconductor light-emitting element, and the third object is a second foreign matter.

The invention discloses a quick assembly and disassembly type modular telescopic supporting structure, and belongs to the field of general machinery design. The problems that a traditional supporting structure is low in disassembly and assembly efficiency, poor in adjusting precision and inconvenient to store and transport are solved. The structure comprises an outer cylinder, a self-locking telescopic structure, a magnetic suction quick-connection node structure and folding devices, the bottom end of the outer cylinder is movably connected with the magnetic suction quick-connection node structure, an inner cavity is connected with the self-locking telescopic structure in a clamped mode, and the folding devices are annularly fixed to the surface of the magnetic suction quick-connection node structure. The self-locking telescopic structure adopts a self-locking telescopic unit of a hexagonal nested sleeve, and is matched with an elastic ratchet bar, a slope clamping block and a compression spring, so that single-hand downward pressure stepless regulation is realized, locking is realized by virtue of friction and occlusion, the vertical deviation is small, and the bearing capacity is high; six permanent magnets are arranged at the bottom and an inner cavity of the magnetic attraction quick connection node, are distributed in an annular array mode and are quickly spliced by rotating and clamping the bottom end of an outer cylinder, electric power is not needed, and the bolt risk is avoided. And the folding storage mechanism supports quick disassembly of the supporting legs and is convenient to store and carry.

The invention belongs to the technical field of gap measurement, and particularly relates to a high-temperature-resistant transparent shell type eddy current tip gap measuring device and method, and the device comprises a sensor probe module, a signal conditioning module, a data collection module and a data processing module. The sensor probe module is mounted on the outer wall of the casing; the sensor probe module comprises a permanent magnet excitation source, a soft magnet magnetic core and a receiving coil; the signal conditioning module is electrically connected with the receiving coil and is used for amplifying, filtering and integrating the weak induction signal; the data acquisition module is electrically connected with the signal conditioning module and converts an analog signal into a digital signal; the data processing module is used for processing the acquired digital signals and extracting blade tip clearance information.

The invention belongs to the technical field of seeding, and particularly relates to an intelligent precision seed-metering device based on electromagnetic control and a seed-metering method, and the seed-metering device comprises a seed-metering disc assembly and an electromagnetic intelligent seed pushing assembly. The seed metering plate assembly is provided with a seed hole with an annular permanent magnet; the electromagnetic intelligent seed pushing assembly comprises a control module, an electrified solenoid and a flexible seed pushing assembly with a permanent magnet sliding block and a flexible pushing disc. During working, the magnetic attraction force between the seed-metering disc permanent magnet and the sliding block permanent magnet is combined with the controllable electromagnetic force generated by the electrified solenoid to cooperatively drive the sliding block to complete the seed pushing action. The electric signals are controlled through programming, and various operation modes such as ultra-high speed, precision low loss and variable jump broadcast can be switched in real time. According to the invention, the embedded real-time monitoring and fault diagnosis of the seed pushing action are realized by using an electric signal generated by the movement of the sliding block in the induction coil. According to the invention, the problem that the existing seed-metering device is difficult to consider high-speed, low-loss and multi-mode operation and intelligent monitoring at the same time is solved.

The invention relates to the technical field of electrode coating, in particular to electrode slurry filtering equipment which comprises a machine shell and a circular-tube-shaped filter screen, a circular-ring-shaped ring piece is fixedly connected to the bottom face in the machine shell, a discharging pipe is rotatably installed at the top of the ring piece, an upper cover plate is fixedly connected to the top end in the machine shell, a shell is rotatably installed on the bottom face of the upper cover plate, and a discharging pipe is rotatably installed on the shell. The discharging pipe is fixedly connected with the shell, filter cloth is fixedly connected to the inner wall of the shell, a connecting block is fixedly connected to the bottom face in the machine shell, a sealing plate is fixedly connected to the top of the connecting block so as to support and seal the bottom of the filter cloth, an annular connecting plate is fixedly connected to the inner wall of the ring piece, and the inner ring of the connecting plate is rotationally connected to the sealing plate. In the using process of the equipment, the scraper blade is controlled to periodically scrape slag through the magnetic force effect between the permanent magnet and the scraper blade, so that filter cloth is prevented from being blocked, the shutdown cleaning frequency is reduced, the shutdown overhauling time is saved, and the production efficiency is greatly improved.

The invention discloses a high-power and frequency-adjustable gyrotron loading test system for nuclear fusion, which relates to the technical field of nuclear fusion and comprises a 2-megawatt coaxial gyrotron with adjustable frequency of 170 / 240GHz and a loading test platform. The loading test platform comprises a gyrotron part loading system, a strong magnet system, a vacuumizing system, a power supply system, a load system, a cooling system, a monitoring and diagnosing system and a control system. The component loading system is used for precise assembly; the strong magnet system provides an adjustable strong magnetic field; the vacuumizing system maintains ultrahigh vacuum; the power supply system comprises a cathode power supply and a body power supply, and the body power supply is used as a high-voltage amplifier to realize 10kHz rapid power modulation; the cooling system provides independent active cooling; the load system simulates a real load; comprehensive detection of the monitoring and diagnosis system; and the control system realizes coordinated control and rapid protection. According to the invention, a complete solution is provided for development, test, operation and maintenance of the 2-megawatt-level and frequency-adjustable gyrotron.

The invention provides a water-cooled magnet magnetic field ripple shielding system, which belongs to the technical field of water-cooled magnets and comprises a thermostat and a superconducting block, the superconducting block is positioned in a constant-temperature cavity of the thermostat and is coaxial with a room-temperature hollow cavity in the center of the thermostat, liquid nitrogen is injected into the constant-temperature cavity, and when the superconducting block enters a superconducting state, the superconducting block is separated from the constant-temperature cavity. The sum of the induced magnetic flux variation of the water-cooled magnet power supply in the annular cavity of the superconducting block and the magnetic flux variation generated by the induced current of the superconducting block is zero, and the magnetic flux in the room temperature hollow cavity is in a steady state; the invention further provides a using method of the water-cooled magnet magnetic field ripple shielding system. Magnetic field ripples in an experiment sample space during a water-cooled magnet field stabilization experiment are shielded, the magnetic field stability of a water-cooled magnet magnetic field in the sample experiment space is ensured, the quality of the water-cooled magnet magnetic field is improved, and the signal-to-noise ratio of an experiment measurement signal is improved.

A system for building a play area can include two or more panels, each of the two or more panels including a connector and at least one magnet positioned in the connector such that the at least one magnet is able to rotate, the at least one magnet including first and second magnets housed in respective first and second ends of the connector, the at least one magnet including at least one cylindrical magnet, the at least one cylindrical magnet being diametrically magnetized; and first and second dowels connected by the connector; each of the two or more panels being configured such that when at least one edge of each of the first and second panels are brought towards each other from any direction, the at least one magnet in each panel orientates such that a magnetic connection is formed between the two or more panels.

The invention discloses a motor, a compressor and refrigeration equipment, and relates to the technical field of permanent magnet motors, the motor comprises a stator iron core and a rotor iron core, rotor holes are formed in the inner circumference of the stator iron core, the number of stator grooves is Q, the width of each stator groove opening in the circumferential direction is W, and the minimum radius of each rotor hole is R; an inter-pole groove is concavely arranged between every two adjacent magnetic steel grooves and on the periphery of the rotor core, n harmonic grooves distributed at intervals are further concavely arranged on the periphery of the rotor core in sequence, central angles of the n harmonic grooves are A1, A2, and An in sequence on the circle center of the rotor core, a central angle of the inter-pole groove is As, and the number of poles of the motor is 2P, and the formula is satisfied. The technical scheme provided by the invention aims to suppress harmonic waves, reduce torque pulsation and further reduce the operation noise of the motor.