Integrally sintered neodymium iron boron Halbach ring multi-pole rotating excitation magnetic field press

Abstract

The invention discloses an integrally sintered neodymium iron boron Halbach ring multi-pole rotating excitation magnetic field press which comprises a rack, a base, a die assembly, an upper die servo electric cylinder mechanism, a lower die servo electric cylinder mechanism, an excitation structure and a rotating excitation device. The base is fixedly arranged on the ground or a working platform; the rack is mounted above the base; the die assembly comprises an upper annular male die, a lower annular male die, a non-magnetic steel female die, a magnetic conductive die core and a die base. The excitation structure comprises an excitation frame, an excitation coil, an excitation pole and a magnetic conductive pole shoe; excitation forming of any even number of poles can be carried out by using a mold of the same size, the requirement for multiple pole numbers is met, the equipment investment is reduced, the production cost is reduced, the production period is shortened, the production flexibility and efficiency are improved, the diversified requirements of different clients and application scenes for the Halbach magnet ring are met, and the production efficiency is improved. The problems that an existing magnetic field press is single in forming pole number and uneven in surface magnetic field distribution are solved, and technical conversion and marketization are promoted.

Description

Technical Field

[0001] The present invention relates to the technical field related to magnetic field presses, and in particular to an integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press. Background Art

[0002] As a special form of NdFeB rare earth permanent magnet material, the integrally sintered NdFeB Halbach ring has broad application prospects in permanent magnet motors, magnetic gears, magnetic levitation bearings, medical nuclear magnetic systems and other fields. For example, in the field of permanent magnet motors, the magnetic properties of the Halbach magnetic ring are 1.4 times higher than those of traditional magnetic rings, which can increase the motor power efficiency by 2 times, and can also improve the power density per unit mass, motor torque and speed. The permanent magnet motor based on it does not require electromagnetic field shielding, which helps to solve the problems of low power and speed, and high noise of domestic motors.

[0003] However, the production of integrally sintered NdFeB Halbach rings currently faces many difficulties on the market. There is only one model of integrally sintered NdFeB Halbach rings with 4 poles and 6mm in the market, and the magnetic field distribution is uneven. Most of the other pole numbers or sizes are spliced structures. The spliced structure has problems such as difficulty in confining the magnetic field, uneven distribution, need for anti-slip, complex structural installation, poor dynamic balance and structural stability, which limit its application and promotion.

[0004] The existing axially oriented ordinary ring magnetic field press cannot be used for the die-forming of integrally sintered NdFeB Halbach rings with radially oriented structures; the radially oriented radiation ring cannot complete multi-pole AC commutation output because the rotating magnetic field is a DC constant current output, and cannot be used for the die-forming of Halbach rings with multi-pole radially oriented structures; although there is a "Halbach magnetic ring one-time forming magnetic field press" (CN202411181760.7), this equipment can only form 4 poles in one molding device, with a size range of 6 to 28 mm in diameter. Different equipment is required for Halbach rings with different pole numbers, resulting in increased production costs. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-pole rotating excitation magnetic field press for integrally sintered NdFeB Halbach rings to fill the market gap for multi-pole integrally sintered NdFeB Halbach rings, solve the problems of single forming pole number and uneven surface magnetic field distribution of existing magnetic field presses, realize the forming of integrally sintered NdFeB Halbach rings with different pole numbers by one device, and promote its technological transformation and marketization.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press, comprising a frame, a base, a mold assembly, an upper mold servo electric cylinder mechanism, a lower mold servo electric cylinder mechanism, an excitation structure, and a rotating excitation device;

[0008] The base is fixedly arranged on the ground or on a working platform;

[0009] The rack is installed above the base to provide a support framework for the entire device;

[0010] The mold assembly includes an upper annular punch, a lower annular punch, a non-magnetic steel die, a magnetic conductive mold core and a mold base;

[0011] The upper die servo electric cylinder mechanism is installed on the top of the frame, and its output end is connected to the upper cylinder push rod; the lower end of the upper cylinder push rod is fixedly connected to the upper pressure head;

[0012] The lower die servo electric cylinder mechanism is installed on the base, and its output end is connected to the lower cylinder push rod; the upper end of the lower cylinder push rod is connected to the die base, and the upper die servo electric cylinder mechanism and the lower die servo electric cylinder mechanism respectively drive the upper pressure head and the die base to move up and down relative to each other;

[0013] The rotary excitation device includes a servo motor, a reducer and a transmission member. The servo motor transmits the output torque to the gear under the mold base through the reducer and the transmission member, driving the mold base to rotate;

[0014] The excitation structure includes an excitation frame, an excitation coil, an excitation pole, and a magnetic pole shoe; the excitation frame is mounted on the frame and arranged around the mold assembly; the excitation coil is wound around the excitation pole; the excitation pole is fixed to the excitation frame; the magnetic pole shoe is mounted on one end of the excitation pole close to the mold assembly, and is used to guide the magnetic field generated by the excitation coil to the mold assembly;

[0015] The non-magnetic steel die is arranged on the die base; the magnetic conductive mold core is located inside the non-magnetic steel die; the upper annular punch is fixedly connected to the upper pressure head, and the lower annular punch is installed on the die base and arranged opposite to the upper annular punch; under the action of the upper die servo electric cylinder mechanism and the lower die servo electric cylinder mechanism, the upper annular punch and the lower annular punch move up and down relative to the non-magnetic steel die to achieve mold closing and pressing.

[0016] A preferred solution is that when working, low-frequency alternating current is passed through the excitation coil to generate an alternating excitation magnetic field in the two opposing excitation poles. The magnetic field is strengthened by the contraction of the magnetic pole shoes and then transmitted to the outer wall of the non-magnetic steel die, passes through the non-magnetic steel die to excite the internal magnetic powder, and then is guided from the top to the bottom to the excitation frame through the magnetic core and then returns to the excitation pole to form a complete magnetic circuit; during the excitation process, the mold assembly rotates under the drive of the rotary drive device, and the magnetic field changes alternately in a sinusoidal waveform on the circumference, and the arrangement of the magnetic powder in the non-magnetic steel die changes in a sinusoidal wave. At the same time, the upper mold servo electric cylinder mechanism and the lower mold servo electric cylinder mechanism drive the upper annular punch and the lower annular punch to press against each other, so that the magnetic powder forms a Halbach magnetic ring with a multi-pole external field; by precisely controlling the matching relationship between the rotational angular velocity and the excitation waveform, the excitation, rotation and pressure are synchronized, and Halbach magnetic rings with different pole numbers can be controllably formed.

[0017] In a preferred embodiment, the rotary drive device is in driving connection with the mold base, and transmits power to the mold base through a coupling, belt drive or gear drive to drive the mold assembly to rotate.

[0018] In a preferred solution, the electric cylinder reducer parts of the upper mold servo electric cylinder mechanism and the lower mold servo electric cylinder mechanism are both equipped with torque sensors; the torque sensors are used to detect torque and convert it into ejection pressure, and obtain the appropriate molding pressure according to the end face area of different Halbach magnetic rings; the electric cylinder reducer accurately controls the molding speed. For Halbach magnetic rings with a large number of poles, the control system slows down the rotational angular velocity of the electric cylinder reducer to ensure sufficient orientation excitation, and at the same time slows down the driving speed of the electric cylinder reducer to ensure that the orientation degree is not destroyed.

[0019] In a preferred solution, the control system is a programmable logic controller, which accurately controls the rotational angular velocity and driving speed of the electric cylinder reducer, as well as the synchronization with the phase of the alternating excitation current, by programming.

[0020] In a preferred embodiment, the excitation coil is wound with a small number of turns using a copper tube coated with insulating material. The copper tube is connected to a power supply and excited with a low-frequency AC magnetic field with low voltage and high current. The excitation coil fits tightly with the excitation pole to ensure effective generation and transmission of the magnetic field.

[0021] In a preferred solution, cooling oil is passed through the interior of the copper tube, and the cooling oil circulates through a circulating cooling system to remove heat generated by the excitation coil, thereby ensuring stable operation of the excitation coil.

[0022] In a preferred embodiment, the magnetic pole shoe is made into a straight line and a spiral shape; the magnetic pole shoe is installed at one end of the excitation pole close to the mold assembly through a detachable connection to meet the multi-pole excitation requirements of straight pole and oblique pole magnetic rings, and the normal operation of other components will not be affected when replacing magnetic pole shoes of different shapes.

[0023] In a preferred solution, the excitation coil changes the shape of the current passed through it and uses a control system to adjust the current waveform to achieve the molding of the Halbach magnetic ring with special waveform requirements.

[0024] In a preferred embodiment, the frame is provided with a guardrail or a guard door.

[0025] Due to the application of the above technical solution, the beneficial effects of this application compared with the prior art are:

[0026] The present application provides an integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press, which realizes the excitation molding of any even number of poles using the same size mold. One device can meet the needs of multiple pole numbers, reducing equipment investment, reducing production costs and production cycles, and improving production flexibility and efficiency: by replacing the magnetic pole shoes and adjusting the current waveform, it can achieve the production of oblique pole excitation and special waveform magnetic rings of various angles, meeting the diverse needs of different customers and application scenarios for Halbach magnetic rings; the excitation coil is cooled by cooling oil circulation to ensure the stability of the excitation system during long-term operation of the equipment and extend the service life of the equipment; the guardrail or protective door set on the frame effectively prevents the operator from being injured by the moving parts of the equipment, thereby improving the safety of equipment operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic structural diagram of a monolithic sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press of the present invention;

[0029] Figure 2 Schematic diagram of the magnetic pole shoe structure;

[0030] Figure 3 This is a schematic diagram of the matching structure between the magnetic pole shoe and the mold assembly;

[0031] Figure 4 This is a schematic diagram of the waveform of the alternating excitation current when the mold assembly rotates one circle (360°);

[0032] Figure 5 This is a schematic diagram of the external magnetic circuit structure of a twelve-pole integrally sintered NdFeB Halbach magnetic ring.

[0033] Among them, 1. Frame; 2. Base; 3. Mold assembly; 4. Upper mold servo electric cylinder mechanism; 5. Lower mold servo electric cylinder mechanism; 6. Excitation structure; 7. Upper annular punch; 8. Lower annular punch; 9. Non-magnetic steel die; 10. Magnetic core; 11. Mold base; 12. Upper cylinder push rod; 13. Upper pressure head; 14. Lower cylinder push rod; 15. Excitation frame; 16. Excitation coil; 17. Excitation pole; 18. Magnetic pole shoe; 19. Rotating excitation device. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] In this application, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0037] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0038] Furthermore, the terms "installed," "disposed," "provided with," "connected," "connected," and "socketed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0039] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] Example 1

[0041] See Figure 1-5 The present application provides an integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press, comprising a frame 1, a base 2, a mold assembly 3, an upper mold servo electric cylinder mechanism 4, a lower mold servo electric cylinder mechanism 5, an excitation structure 6 and a rotating excitation device 19;

[0042] The base 2 is fixedly arranged on the ground or a work platform;

[0043] The frame 1 is installed above the base 2 to provide a support frame for the entire device;

[0044] The mold assembly 3 includes an upper annular punch 7, a lower annular punch 8, a non-magnetic steel die 9, a magnetic conductive mold core 10 and a mold base 11;

[0045] The upper die servo electric cylinder mechanism 4 is installed on the top of the frame 1, and its output end is connected to the upper cylinder push rod 12; the lower end of the upper cylinder push rod 12 is fixedly connected to the upper pressure head 13;

[0046] The lower die servo electric cylinder mechanism 5 is mounted on the base 2, and its output end is connected to the lower cylinder push rod 14; the upper end of the lower cylinder push rod 14 is connected to the die base 11, and the upper die servo electric cylinder mechanism 4 and the lower die servo electric cylinder mechanism 5 respectively drive the upper pressure head 13 and the die base 11 to move up and down relative to each other;

[0047] The rotary excitation device 19 includes a servo motor, a reducer and a transmission member, wherein the transmission member is a synchronous belt, a transmission shaft or a gear; the servo motor transmits the output torque to the gear below the mold base 11 through the reducer and the transmission member, thereby driving the mold base 11 to rotate;

[0048] The excitation structure 6 includes an excitation frame 15, an excitation coil 16, an excitation pole 17, and a magnetic pole shoe 18. The excitation frame 15 is mounted on the frame 1 and surrounds the mold assembly 3. The excitation coil 16 is wound around the excitation pole 17. The excitation pole 17 is fixed to the excitation frame 15. The magnetic pole shoe 18 is mounted on one end of the excitation pole 17 close to the mold assembly 3 to guide the magnetic field generated by the excitation coil 16 to the mold assembly 3.

[0049] The non-magnetic steel die 9 is arranged on the die base 11; the magnetic conductive mold core 10 is located inside the non-magnetic steel die 9; the upper annular punch 7 is fixedly connected to the upper pressure head 13, and the lower annular punch 8 is installed on the die base 11 and arranged opposite to the upper annular punch 7; under the action of the upper die servo electric cylinder mechanism 4 and the lower die servo electric cylinder mechanism 5, the upper annular punch 7 and the lower annular punch 8 move up and down relative to the non-magnetic steel die 9 to achieve mold closing and pressing.

[0050] During operation, low-frequency alternating current is passed through the excitation coil 16 to generate an alternating excitation magnetic field in the two opposing excitation poles 17. The magnetic field is contracted and enhanced by the magnetic pole shoe 18 and then transmitted to the outer wall of the non-magnetic steel die 9, passes through the non-magnetic steel die 9 to excite the internal magnetic powder, and then is guided from the top to the bottom to the excitation frame 15 through the magnetic core 10 and then returns to the excitation pole 17 to form a complete magnetic circuit; during the excitation process, the mold assembly 3 rotates under the drive of the rotary drive device, and the magnetic field changes alternately in a sinusoidal waveform on the circumference. The arrangement of the magnetic powder in the non-magnetic steel die 9 changes in a sinusoidal wave, and at the same time, the upper mold servo electric cylinder mechanism 4 and the lower mold servo electric cylinder mechanism 5 drive the upper annular punch 7 and the lower annular punch 8 to press against each other, so that the magnetic powder forms a Halbach magnetic ring with a multi-pole external field; by precisely controlling the matching relationship between the rotational angular velocity and the excitation waveform, the excitation, rotation and pressure are synchronized, and Halbach magnetic rings with different pole numbers can be controlled to be formed.

[0051] The rotary drive device is in transmission connection with the mold base 11 and transmits power to the mold base 11 through a coupling, belt drive or gear drive to drive the mold assembly 3 to rotate, thereby meeting the rotation requirements under different working conditions.

[0052] The electric cylinder reducer parts of the upper die servo electric cylinder mechanism 4 and the lower die servo electric cylinder mechanism 5 are both equipped with torque sensors; the torque sensors are used to detect torque and convert it into ejection pressure, and obtain the appropriate molding pressure according to the end face area of different Halbach magnetic rings; the electric cylinder reducer accurately controls the molding speed. For Halbach magnetic rings with a large number of poles, the control system (such as a programmable logic controller) slows down the rotational angular velocity of the electric cylinder reducer to ensure sufficient orientation excitation, and at the same time slows down the driving speed of the electric cylinder reducer to ensure that the orientation degree is not destroyed.

[0053] The control system is a programmable logic controller, which accurately controls the rotational angular velocity and driving speed of the electric cylinder reducer and the synchronization with the phase of the alternating excitation current by writing a program.

[0054] The excitation coil 16 is wound with a small number of turns using a copper tube coated with insulating material. The copper tube is connected to a power supply and excited by a low-frequency AC magnetic field with low voltage and high current. The excitation coil 16 is tightly fitted with the excitation pole 17 to ensure effective generation and transmission of the magnetic field.

[0055] Cooling oil is passed through the copper tube, and the cooling oil circulates through the circulating cooling system to take away the heat generated by the excitation coil 16 and ensure the stable operation of the excitation coil 16.

[0056] The magnetic pole shoe 18 is made into a straight line and a spiral shape; the magnetic pole shoe 18 is installed at one end of the excitation pole 17 close to the mold assembly 3 through a detachable connection method (such as bolt connection, etc.) to meet the multi-pole excitation requirements of straight pole and oblique pole magnetic rings, and replacing the magnetic pole shoe 18 of different shapes does not affect the normal operation of other components.

[0057] The excitation coil 16 changes the shape of the current passed through it and adjusts the current waveform using a control system to achieve the shaping of the Halbach magnetic ring with special waveform requirements, such as a trapezoidal wave magnetic ring.

[0058] The frame 1 is provided with a guardrail or a guard door to prevent the operator from accidentally contacting the moving parts when the equipment is running, thereby ensuring the operator's safety.

[0059] When using the equipment, first install and debug it:

[0060] According to the design requirements, firmly fix the base 2 on the ground or work platform to ensure its levelness and stability. Then install the rack 1 on top of the base 2 and fix it with bolts or other connectors. Check the verticality and installation security of the rack 1.

[0061] Install the upper die servo electric cylinder mechanism 4 and the lower die servo electric cylinder mechanism 5, install the upper die servo electric cylinder mechanism 4 on the top of the frame 1, ensure its installation position is accurate, connect the upper cylinder push rod 12 and the upper pressure head 13, and adjust their position and verticality; install the lower die servo electric cylinder mechanism 5 on the base 2, connect the lower cylinder push rod 14 and the mold base 11, check the tightness of each connection part, and ensure that the electric cylinder can be driven normally.

[0062] Install the mold assembly 3, place the non-magnetic steel die 9 on the mold base 11, ensure that it is firmly installed, put the magnetic core 10 into the non-magnetic steel die 9, ensure its accurate position, install the upper annular punch 7 and the lower annular punch 8, the upper annular punch 7 is fixedly connected to the upper pressure head 13, the lower annular punch 8 is installed on the mold base 11 and is arranged opposite to the upper annular punch 7, adjust the position of the punch to ensure the mold closing accuracy.

[0063] Install the excitation structure 6, install the excitation frame 15 on the frame 1 so that it surrounds the mold assembly 3, wind the excitation coil 16 on the excitation pole 17, ensure that it is tightly wound, then fix the excitation pole 17 on the excitation frame 15, install the magnetic pole shoe 18, select the magnetic pole shoe 18 of appropriate shape according to the required magnetic ring type, and install it on the end of the excitation pole 17 close to the mold assembly 3 through a detachable connection.

[0064] Connect the rotary drive device to the mold base 11 and install and debug it correctly according to the selected transmission method (coupling, belt drive or gear drive) to ensure smooth power transmission.

[0065] Install the cooling oil circulation cooling system, connect the cooling oil pipe to the copper pipe in the excitation coil 16 to ensure that the cooling oil circulates normally, connect the power supply and control system, check and debug the electrical circuits, and ensure that all components can be powered on and operate normally.

[0066] After the equipment is installed, conduct comprehensive debugging, check the movement of each electric cylinder, test the rotation effect of the rotary drive device, detect the accuracy of the torque sensor, adjust the excitation current and waveform, observe the magnetic field distribution, and ensure that all components of the equipment are operating normally and can meet production requirements.

[0067] The molding operation process is as follows:

[0068] Preparation: According to the number and size of the Halbach magnetic ring poles to be formed, select the appropriate mold assembly 3 and magnetic pole shoe 18 and install them on the equipment. Prepare the NdFeB magnetic powder and evenly fill it into the non-magnetic steel die 9.

[0069] Parameter setting: Set the forming speed of the electric cylinder, the rotational angular velocity of the rotary drive device, and the frequency and waveform of the excitation current through the control system (programmable logic controller); for magnetic rings with a large number of poles, appropriately reduce the rotational angular velocity and forming speed, and adjust the excitation current frequency and waveform to ensure that the magnetic powder is fully oriented and excited.

[0070] Molding process: Start the equipment and apply low-frequency alternating current. The excitation structure 6 generates an alternating excitation magnetic field, and the mold assembly 3 rotates driven by the rotary drive device. At the same time, the upper mold servo electric cylinder mechanism 4 and the lower mold servo electric cylinder mechanism 5 drive the upper annular punch 7 and the lower annular punch 8 to press against each other. Under the combined action of the magnetic field, rotation, and pressure, the magnetic powder in the die gradually forms a Halbach magnetic ring with the required number of poles and shape.

[0071] Finished product processing: After forming is completed, the magnetic ring is taken out for subsequent processing, such as sintering and processing, to obtain the final integral sintered NdFeB Halbach ring product.

[0072] Equipment maintenance and care:

[0073] Regularly check the connection of each component of the equipment to ensure that the bolts, nuts and other connectors are not loose. Check the operating condition of the electric cylinder, including whether the piston rod of the electric cylinder moves smoothly and the lubrication condition of the electric cylinder reducer. If there is any abnormality, repair and maintain it in time.

[0074] Regularly check the accuracy of the torque sensor and calibrate it in time if there is any deviation. Check the transmission components of the rotary drive device, such as couplings, belts, gears, etc., and replace them in time if they are worn.

[0075] Regularly clean the dust and impurities on the surface of the excitation coil 16 and the mold assembly 3 to prevent them from affecting the magnetic field distribution and product quality; check the level and quality of the cooling oil, replace the cooling oil regularly, and ensure the normal operation of the cooling system.

[0076] Regularly check the integrity and reliability of guardrails or protective doors to ensure that they can effectively protect the safety of operators; check the electrical system of the equipment to prevent problems such as line aging and short circuits.

[0077] Example 2

[0078] Molded 8-pole integrally sintered NdFeB Halbach magnetic ring

[0079] Equipment preparation: Select a suitable straight-shaped magnetic pole shoe 18, and use bolts to install it on the end of the excitation pole 17 close to the mold assembly 3. Make sure the bolts are tightened to prevent the magnetic pole shoe 18 from loosening during equipment operation; tightly wind the excitation coil 16 made of a copper tube with insulating material on the outside around the excitation pole 17, and connect it to the cooling oil circulation system to ensure that the cooling oil can circulate normally to take away heat; install the upper mold servo electric cylinder mechanism 4 on the top of the frame 1, connect the upper cylinder push rod 12 and the upper pressure head 13; install the lower mold servo electric cylinder mechanism 5 on the base 2, connect the lower cylinder push rod 14 and the mold base 11, place the non-magnetic steel die 9 on the mold base 11, put in the magnetic mold core 10, and then install the upper annular punch 7 and the lower annular punch 8 to ensure the mold installation accuracy.

[0080] Parameter setting: The parameters of the upper die servo electric cylinder mechanism 4 and the lower die servo electric cylinder mechanism 5 are set through the programmable logic controller (PLC), and the forming speed is set to 10 mm per second. This speed can ensure that the magnetic powder has enough time to orient under the action of the magnetic field and meet a certain production efficiency. According to the characteristics of the 8-pole magnetic ring, the rotational angular velocity of the rotary drive device is set to 30 revolutions per minute to ensure that the coordination of the magnetic field and the mold rotation can uniformly orient the magnetic powder. The low-frequency AC parameters of the excitation coil 16 are set to 50 V voltage, 80 A current, and 20 Hz frequency to generate a suitable alternating excitation magnetic field.

[0081] Forming process: an appropriate amount of NdFeB magnetic powder is evenly filled into the non-magnetic steel die 9, the equipment is started, and a low-frequency alternating current with set parameters is passed through the excitation coil 16 to generate an alternating excitation magnetic field in the two opposing excitation poles 17. The magnetic field is contracted and enhanced by the magnetic pole shoe 18 and then transmitted to the outer wall of the non-magnetic steel die 9, passing through the non-magnetic steel die 9 to excite the internal magnetic powder; the mold assembly 3 starts to rotate driven by the rotary drive device, and the magnetic field changes alternately in a sinusoidal waveform on the circumference, and the arrangement of the magnetic powder in the non-magnetic steel die 9 changes in a sinusoidal wave; at the same time, the upper mold servo electric cylinder mechanism 4 and the lower mold servo electric cylinder mechanism 5 drive the upper annular punch 7 and the lower annular punch 8 to press against the non-magnetic steel die 9 at a speed of 10 mm per second; under the synergistic effect of the magnetic field, rotation and pressure, after 30 seconds of pressing, the magnetic powder gradually forms an 8-pole integrally sintered NdFeB Halbach magnetic ring.

[0082] Finished product processing: After molding is completed, the upper mold servo electric cylinder mechanism 4 and the lower mold servo electric cylinder mechanism 5 drive the mold to separate and remove the magnetic ring; a preliminary inspection is carried out on the magnetic ring to observe whether its appearance is complete and whether there are any defects such as missing materials or deformation; the qualified magnetic ring is placed in a sintering furnace and sintered according to a specific sintering process to improve the density and magnetic properties of the magnetic ring; the sintered magnetic ring is mechanically processed, such as grinding and cutting, to achieve the required dimensional accuracy and surface roughness, and the final 8-pole integral sintered NdFeB Halbach magnetic ring product is obtained.

[0083] Example 3

[0084] Molded 12-pole oblique-pole integrally sintered NdFeB Halbach magnetic ring

[0085] Equipment preparation: Replace the spiral-shaped magnetic pole shoe 18 and reinstall it on the excitation pole 17. Check and ensure that the cooling oil circulation system, electric cylinder mechanism, mold assembly 3 and other equipment components are in normal working condition. Check the transmission components of the rotary drive device and the mold base 11, such as the tension of the belt or the engagement of the gears, to ensure stable power transmission.

[0086] Parameter setting: Considering that the 12-pole oblique-pole magnetic ring has a large number of poles and a special structure, the forming speed of the upper mold servo electric cylinder mechanism 4 and the lower mold servo electric cylinder mechanism 5 is adjusted through PLC and set to 8 mm per second to ensure that the magnetic powder has more time to orient; the rotational angular velocity of the rotary drive device is reduced to 20 revolutions per minute to better coordinate the magnetic field with the mold rotation, and the current shape of the excitation coil 16 is adjusted to a waveform suitable for oblique-pole excitation. At the same time, the voltage is set to 60V, the current is set to 90A, and the frequency is set to 15Hz.

[0087] Molding process: After the magnetic powder is evenly filled into the non-magnetic steel die 9, the equipment is started; the alternating excitation magnetic field generated by the excitation coil 16 is guided to the mold assembly 3 through the spiral-shaped magnetic pole shoe 18. The mold assembly 3 rotates slowly under the drive of the rotary drive device. The upper mold servo electric cylinder mechanism 4 and the lower mold servo electric cylinder mechanism 5 drive the upper and lower annular punches 8 to press at a speed of 8 mm per second. During the pressing process, the matching relationship between the rotation angular velocity and the excitation waveform is precisely controlled. After 40 seconds of pressing, a 12-pole oblique-pole integrally sintered NdFeB Halbach magnetic ring is formed.

[0088] Finished product processing: After forming, the magnetic rings undergo an appearance inspection. Qualified magnetic rings undergo sintering and machining. During the sintering process, the sintering temperature curve and holding time are adjusted according to the characteristics of the skewed-pole magnetic rings to ensure stable magnetic ring performance. During machining, the design dimensions are strictly followed to ensure the accuracy of the magnetic rings. The result is a 12-pole skewed-pole integrally sintered NdFeB Halbach magnetic ring that meets the requirements.

[0089] The present application provides an integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press, which realizes the excitation molding of any even number of poles using the same size mold. One device can meet the needs of multiple pole numbers, reducing equipment investment, reducing production costs and production cycles, and improving production flexibility and efficiency: by replacing the magnetic pole shoe 18 and adjusting the current waveform, it is possible to achieve the production of oblique pole excitation and special waveform magnetic rings of various angles, meeting the diverse needs of different customers and application scenarios for Halbach magnetic rings; the cooling oil circulation is used to cool the excitation coil 16 to ensure the stability of the excitation system of the equipment during long-term operation and extend the service life of the equipment; the guardrail or protective door set on the frame 1 effectively prevents the operator from being injured by the moving parts of the equipment, thereby improving the safety of equipment operation.

[0090] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press, characterized in that: It includes a frame, a base, a mold assembly, an upper mold servo electric cylinder mechanism, a lower mold servo electric cylinder mechanism, an excitation structure and a rotary excitation device; The base is fixedly arranged on the ground or on a working platform; The rack is installed above the base to provide a support framework for the entire device; The mold assembly includes an upper annular punch, a lower annular punch, a non-magnetic steel die, a magnetic conductive mold core and a mold base; The upper die servo electric cylinder mechanism is installed on the top of the frame, and its output end is connected to the upper cylinder push rod; the lower end of the upper cylinder push rod is fixedly connected to the upper pressure head; The lower die servo electric cylinder mechanism is installed on the base, and its output end is connected to the lower cylinder push rod; the upper end of the lower cylinder push rod is connected to the die base, and the upper die servo electric cylinder mechanism and the lower die servo electric cylinder mechanism respectively drive the upper pressure head and the die base to move up and down relative to each other; The rotary excitation device includes a servo motor, a reducer and a transmission member. The servo motor transmits the output torque to the gear under the mold base through the reducer and the transmission member, driving the mold base to rotate; The excitation structure includes an excitation frame, an excitation coil, an excitation pole, and a magnetic pole shoe; the excitation frame is mounted on the frame and arranged around the mold assembly; the excitation coil is wound around the excitation pole; the excitation pole is fixed to the excitation frame; the magnetic pole shoe is mounted on one end of the excitation pole close to the mold assembly, and is used to guide the magnetic field generated by the excitation coil to the mold assembly; The non-magnetic steel die is arranged on the die base; the magnetic conductive mold core is located inside the non-magnetic steel die; the upper annular punch is fixedly connected to the upper pressure head, and the lower annular punch is installed on the die base and arranged opposite to the upper annular punch; under the action of the upper die servo electric cylinder mechanism and the lower die servo electric cylinder mechanism, the upper annular punch and the lower annular punch move up and down relative to the non-magnetic steel die to achieve mold closing and pressing.

2. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 1, characterized in that: During operation, low-frequency alternating current is passed through the excitation coil to generate an alternating excitation magnetic field in the two opposing excitation poles. The magnetic field is strengthened by the contraction of the magnetic pole shoes and then transmitted to the outer wall of the non-magnetic steel die, passes through the non-magnetic steel die to excite the internal magnetic powder, and then is guided from the top to the bottom to the excitation frame through the magnetic core and then returns to the excitation pole to form a complete magnetic circuit; during the excitation process, the mold assembly rotates driven by the rotary drive device, and the magnetic field changes alternately in a sinusoidal waveform on the circumference. The arrangement of the magnetic powder in the non-magnetic steel die changes in a sinusoidal wave, and at the same time, the upper mold servo electric cylinder mechanism and the lower mold servo electric cylinder mechanism drive the upper annular punch and the lower annular punch to press against each other, so that the magnetic powder forms a Halbach magnetic ring with a multi-pole external field; by precisely controlling the matching relationship between the rotational angular velocity and the excitation waveform, the excitation, rotation and pressure are synchronized, and Halbach magnetic rings with different pole numbers can be controlled to be formed.

3. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 2, characterized in that: The rotary drive device is in driving connection with the mold base, and transmits power to the mold base through a coupling, belt drive or gear drive to drive the mold assembly to rotate.

4. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 1, characterized in that: The electric cylinder reducer parts of the upper die servo electric cylinder mechanism and the lower die servo electric cylinder mechanism are both equipped with torque sensors; the torque sensors are used to detect torque and convert it into ejection pressure, and obtain the appropriate molding pressure according to the end face area of different Halbach magnetic rings; the electric cylinder reducer accurately controls the molding speed. For Halbach magnetic rings with a large number of poles, the control system slows down the rotational angular velocity of the electric cylinder reducer to ensure sufficient orientation excitation, and at the same time slows down the driving speed of the electric cylinder reducer to ensure that the orientation degree is not destroyed.

5. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 4, characterized in that: The control system is a programmable logic controller, which accurately controls the rotational angular velocity and driving speed of the electric cylinder reducer and the synchronization with the phase of the alternating excitation current by writing a program.

6. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 1, characterized in that: The excitation coil is wound with a small number of turns using a copper tube coated with insulating material. The copper tube is connected to a power supply and excited with a low-frequency AC magnetic field with low voltage and high current. The excitation coil is tightly fitted with the excitation pole to ensure effective generation and transmission of the magnetic field.

7. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 6, characterized in that: Cooling oil is passed through the copper tube, and the cooling oil circulates through the circulating cooling system to take away the heat generated by the excitation coil, thereby ensuring the stable operation of the excitation coil.

8. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 1, characterized in that: The magnetic pole shoe is made into a straight line and a spiral shape; the magnetic pole shoe is installed at one end of the excitation pole close to the mold assembly through a detachable connection to meet the multi-pole excitation requirements of straight pole and oblique pole magnetic rings, and the normal operation of other components will not be affected when replacing magnetic pole shoes of different shapes.

9. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 1, characterized in that: The excitation coil changes the shape of the current passed through it and uses a control system to adjust the current waveform to achieve the molding of the Halbach magnetic ring with special waveform requirements.

10. The integrally sintered NdFeB Halbach ring multi-pole rotating excitation magnetic field press according to claim 1, characterized in that: The frame is provided with a guardrail or a guard door.

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