Functionally graded magnetic ring with unequal thickness and method for magnetizing the same

Abstract

The present application relates to a kind of functionization outer diameter unequal thickness magnetic ring and its magnetizing method, belong to permanent magnet motor technical field, the inner diameter of unequal thickness magnetic ring is circular, and the outer diameter is change curve, wherein, the change curve of outer diameter is constant in main magnetic pole portion thickness, and the thickness is reduced in the transition position between adjacent main magnetic pole portion;The unequal thickness magnetic ring adopts bonded neodymium iron boron material.The present application is composed of a functionization outer diameter bonded neodymium iron boron magnetic ring and its matching multipole magnetizing fixture, wherein the outer diameter of magnetic ring adopts two kinds of functionization size, by reducing the thickness of magnetic pole transition area, the harmonic component of surface magnetism of magnetic ring is controlled, and the amplitude of cogging torque is reduced.The multipole magnetizing core of matching magnetizing fixture can magnetize magnetic ring into surface alternately distributed multiple magnetic poles.

Description

Technical Field

[0001] This invention relates to a functionalized magnetic ring with unequal outer diameter and its magnetization method, belonging to the field of permanent magnet motor technology. Background Technology

[0002] A permanent magnet motor is a type of motor that uses permanent magnets to generate a magnetic field, typically used to convert electrical energy into mechanical energy. Compared to traditional motors, permanent magnet motors reduce energy loss and have higher efficiency because they do not require current to excite the magnets, especially under low-to-medium speed operating conditions. Compared to traditional motors, permanent magnet motors can achieve smaller size and lighter weight, making them particularly suitable for applications with high weight and space requirements and high power output, such as electric vehicles and aerospace.

[0003] With the continued rapid pace of industrial development, various fields are placing higher demands on the performance of micromotors. Lower torque ripple is one of the conditions for ensuring the stability of micromotors under high-speed, high-power conditions. Torque ripple is the torque fluctuation caused by electromagnetic factors during motor operation, manifesting as periodic fluctuations in output torque. Torque ripple is mainly caused by cogging torque and current harmonics. Cogging torque is the torque fluctuation caused by the change in magnetic reluctance between the permanent magnet and the stator teeth, while the interaction between current harmonics and the surface magnetic flux density harmonics of the permanent magnet also generates torque fluctuations.

[0004] Torque ripple affects the smooth operation of motors, especially in applications requiring precise control, such as robotics, servo motors, and electric vehicles. Torque ripple also reduces efficiency and accuracy. Due to its presence, the motor generates unnecessary vibration and noise during operation, leading to energy loss. For applications requiring high-precision position control, torque ripple also reduces the system's positioning accuracy and responsiveness.

[0005] Currently, a major method to reduce torque ripple is to reduce cogging torque. This can be achieved through methods such as optimizing the slot-pole ratio, skewed slot design, segmented permanent magnets, and skewed pole design. However, some significant problems have emerged in long-term market applications:

[0006] 1. Optimizing the slot-pole ratio does not require complex modifications to the stator or rotor structure; however, certain application requirements limit the range of selectable slot-pole ratios, making it difficult to find an ideal combination. Furthermore, optimizing the slot-pole ratio has limited overall performance improvement; while it can reduce cogging torque, it may not necessarily optimize other motor performance aspects (such as efficiency and output power).

[0007] 2. The skewed slot design method disperses the fluctuation of cogging torque over a wider angular range by obliquely cutting the stator slots, thereby reducing the amplitude of the cogging torque. However, the skewed slot design increases the difficulty and cost of stator manufacturing, especially in high-power or high-precision motors, where the impact of manufacturing errors is greater. Additionally, skewed slots may increase electromagnetic noise and eddy current losses in the motor and are detrimental to stator heat dissipation.

[0008] 3. Segmented or skewed permanent magnet design: By segmenting the permanent magnet or setting it to skewed poles, changes in magnetic reluctance can be effectively smoothed, thereby significantly reducing cogging torque. However, the design and manufacturing of segmented or skewed permanent magnets are more complex, requiring higher assembly precision, which increases production difficulty and cost. Due to the segmentation or tilting of the permanent magnet, the utilization rate of magnetic flux will decrease, which may affect the power density of the motor.

[0009] There is currently no good solution to the above problems. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a functionalized magnetic ring with unequal outer diameter and its magnetization method, thereby overcoming the problems of cumbersome optimization process, complex processing, and high assembly precision requirements in existing optimized torque pulsation technologies.

[0011] The present invention adopts the following technical solution:

[0012] A functionalized magnetic ring with unequal outer diameter and thickness, wherein the inner diameter of the magnetic ring is circular and the outer diameter is a variation curve, wherein the thickness of the outer diameter variation curve remains constant in the main magnetic pole portion and decreases at the transition position between adjacent main magnetic pole portions;

[0013] The unequal thickness magnetic rings are made of bonded neodymium iron boron material.

[0014] Preferably, the first optimized function for the outer diameter of the unequal-thickness magnetic ring can significantly reduce the high-order harmonics of the surface magnetic waveform, thereby reducing torque pulsation, and the outer diameter satisfies:

[0015] R0 = (R1 - H) + H × cos(nθ)

[0016] Where R0 is the optimized outer diameter of the magnetic ring; R1 is the original outer diameter of the magnetic ring; H is the pole clipping parameter, which satisfies: R1-2H>R2, R2 is the inner diameter of the magnetic ring; H is determined by parametric simulation; n is the number of magnetic poles; θ represents the circumferential angle, 0°<θ<360°.

[0017] Preferably, the second optimized function for the outer diameter of the unequal-thickness magnetic ring significantly reduces the higher harmonics of the surface magnetic waveform, while the fundamental amplitude is higher than that of the first function, and the outer diameter satisfies:

[0018]

[0019] Where R0 is the optimized outer diameter of the magnetic ring; R1 is the original outer diameter of the magnetic ring; H is the pole clipping parameter, which satisfies: R1-2H>R2, R2 is the inner diameter of the magnetic ring; H is determined by parametric simulation; n is the number of magnetic poles; θ represents the circumferential angle, 0°<θ<360°.

[0020] Harmonics in the rotor surface flux density waveform have a significant impact on the torque ripple of permanent magnet motors. On one hand, the flux density waveform affects the magnitude of the cogging torque; on the other hand, harmonics (especially higher-order harmonics) in the flux density waveform cause corresponding harmonic components in the electromagnetic torque. These harmonics induce irregular torque fluctuations, leading to vibration and noise during motor operation, affecting the motor's smoothness and operating efficiency. Therefore, suppressing harmonic components in the flux density waveform, especially higher-order harmonics, is crucial for reducing torque ripple and improving motor performance during the design and operation of permanent magnet motors.

[0021] This invention proposes a functionalized outer diameter unequal thickness magnetic ring and its corresponding magnetization method, consisting of a bonded NdFeB magnetic ring with a functionalized outer diameter and a matching multi-pole magnetization fixture. The outer diameter of the magnetic ring employs two functionalized dimensions. By reducing the thickness of the magnetic pole transition region, the harmonic components of the magnetic ring's surface magnetism are controlled, reducing the amplitude of the cogging torque. The multi-pole magnetizing core of the matching magnetization fixture can magnetize the magnetic ring into a surface with multiple alternating magnetic poles.

[0022] Preferably, when determining the clipping parameter H, according to the constraint R1-2H>R2, the range of H values ​​is set to be [value missing] in the finite element simulation. Set the step size according to the solution requirements, solve all possible H values, and select the H value with the lowest magnetic harmonic distortion rate as the final result.

[0023] The two outer diameter functions mentioned above use the same clipping fundamental wave function cos(nθ). The difference is that the second clipping function adds a third harmonic cos(3nθ) to the first clipping function. Therefore, the fundamental wave amplitude of the second function is higher than that of the first function, and the motor output performance is better. However, due to the introduction of the third harmonic, the magnetic distortion rate is higher than that of the first function.

[0024] Preferably, during manufacturing, the raw materials are first melted at high temperature using casting or smelting methods to form an alloy. The raw materials are selected from elements such as high-purity neodymium iron boron, and small amounts of other elements (such as dysprosium and cerium) are usually added to improve magnetic properties. After the alloy is cooled, it is crushed and ground to produce nanoscale powder. The nanoscale powder is mixed with a binder to obtain a mixture. The mixture is then shaped into a blank of the desired shape using processes such as pressing or injection molding. The shaped blank is cured at a specific temperature to allow the binder to fully cross-link, enhancing the mechanical strength of the magnet. After post-processing and surface treatment, the final product is obtained.

[0025] Preferably, the adhesive is epoxy resin or polyurethane.

[0026] A magnetization method based on the above-mentioned functionalized magnetic ring with unequal outer diameter and thickness is provided, which completes the magnetization by means of a magnetization fixture. The magnetization fixture includes a base, a magnet core, a winding, and a positioning device. The winding is made of enameled copper wire; the base and the positioning device are made of non-magnetic materials.

[0027] During magnetization, place the magnetic ring on the magnetizing core and fix it with a positioning device. Connect the two ends of the winding to the positive and negative terminals of the pulse power supply respectively, and then power on to magnetize. After powering off, remove the magnetic ring structure to complete the magnetization.

[0028] Preferably, the base is provided with a groove for placing the charging magnet core, and a positioning post is provided at the center of the groove for positioning the charging magnet core;

[0029] The magnetic core is provided with through holes and winding grooves, the winding grooves being used to install windings; a slot opening is provided between the winding groove and the through hole, and a magnetic position is formed between adjacent slot openings; the positioning device includes a disk and positioning plates evenly distributed around the circumference of the disk, the disk being placed in the through hole on the magnetic core, and the positioning plates being engaged in the slot openings; the magnetic ring is sleeved inside the positioning device, wherein the transition position of the positioning plate and the magnetic ring corresponds, thereby restricting the circumferential rotation of the magnetic ring.

[0030] Preferably, the number of positioning plates is the same as the number of magnetic poles.

[0031] The magnetic ring of this invention is equipped with a positioning device during magnetization to ensure that the magnetic poles are aligned with the clamp, thereby guaranteeing that the magnetization clamp can magnetize the magnetic ring into the designed low-harmonic magnetic circuit. Since the positioning device is not a mass-produced part, it is preferably made of non-magnetic materials such as nylon plastic, which facilitates 3D printing.

[0032] For any details not covered in this invention, please refer to the prior art.

[0033] The beneficial effects of this invention are as follows:

[0034] 1. Traditional sintered NdFeB surface-mount motors have only one pair of magnetic poles per magnet. During pole trimming and other operations, defects such as chipped corners and cracks are easily generated, making it difficult to guarantee a high yield rate. This invention utilizes the advantages of bonded permanent magnet molding, directly designing the bonded NdFeB magnetic ring with unequal outer diameter and thickness. The outer diameter function of this invention ensures that the unequal thickness magnetic ring structure has a surface magnetic waveform with lower harmonic distortion. The first optimized function of the functionalized unequal outer diameter magnetic ring structure of this invention satisfies: R0=(R1-H)+H×cos(nθ), which can effectively reduce the high-order harmonics of the surface magnetic waveform.

[0035] 2. The second optimized function of the functionalized outer diameter unequal thickness magnetic ring structure of the present invention, wherein the outer diameter satisfies: It can effectively reduce the high-order harmonics of the magnetic waveform. The reduction effect is slightly worse than the first method, but it can ensure that the fundamental amplitude will not drop too much. This means that while reducing torque pulsation, the average output torque of the motor is greater.

[0036] 3. The unequal thickness magnetic ring structure of the present invention has a positioning device to ensure that the center line of the magnetic pole is aligned with the center line of the teeth of the magnetization fixture during the magnetization process, so as to ensure the effectiveness of magnetization.

[0037] 4. The magnetic ring structure of the present invention is formed by pressing or injection molding, etc., and the optimization and preparation process is simple, with low requirements for assembly accuracy. Attached Figure Description

[0038] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0039] Figure 1 The outer diameter of the unequal-thickness magnetic ring is the first type of optimized function;

[0040] Figure 2 The diagram shows the structure of the unequal thickness magnetic ring for the first optimization function, where (a) is a three-dimensional view and (b) is a cross-sectional view.

[0041] Figure 3 This is a schematic diagram of the magnetizing clamp.

[0042] Figure 4 The diagram shows the structure of the positioning device, where (a) is a three-dimensional view of the positioning device and (b) is a schematic diagram of the cooperation between the positioning device and the magnetic ring.

[0043] Figure 5 This is a schematic diagram of the assembly process of the magnetizing fixture, where (a) is a three-dimensional view of the magnetizing core and (b) is a schematic diagram of the cooperation relationship between the magnetizing core, the positioning device and the magnetic ring.

[0044] Figure 6 The outer diameter of the unequal-thickness magnetic ring is the second type of optimization function;

[0045] Figure 7 The diagram shows the structure of the unequal thickness magnetic ring for the second optimization function, where (a) is a three-dimensional view and (b) is a cross-sectional view.

[0046] Figure 8 This is a comparison diagram of the surface magnetic flux density waveforms of the optimized magnetic ring of this invention and the conventional magnetic ring structure;

[0047] Figure 9This is a comparison diagram of the surface magnetic harmonic distribution of the optimized magnetic ring of the present invention and the traditional magnetic ring structure;

[0048] In the figure, 1-magnetic ring, 2-positioning device, 3-magnetic core, 4-winding, 5-base, 11-main magnetic pole part, 12-transition position, 21-positioning plate, 31-slot opening, 32-winding slot, 33-magnetizing position. Detailed Implementation

[0049] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. However, this is not the only description; all aspects not described in detail herein are based on conventional techniques in the art.

[0050] Example 1

[0051] A functionalized magnetic ring with unequal outer diameter and thickness, wherein the inner diameter of the magnetic ring is circular and the outer diameter is a variation curve, wherein the thickness of the outer diameter variation curve remains constant in the main magnetic pole portion and decreases at the transition position between adjacent main magnetic pole portions;

[0052] The unequal thickness magnetic rings are made of bonded neodymium iron boron material.

[0053] The first optimization function for the outer diameter of unequal-thickness magnetic rings, such as... Figure 1 , 2 As shown, it can significantly reduce the high-order harmonics of the surface magnetic waveform, thereby reducing torque pulsation. The outer diameter satisfies:

[0054] R0 = (R1 - H) + H × cos(nθ)

[0055] Where R0 is the optimized outer diameter of the magnetic ring; R1 is the original outer diameter of the magnetic ring; H is the pole clipping parameter, which satisfies: R1-2H>R2, R2 is the inner diameter of the magnetic ring; H is determined by parametric simulation; n is the number of magnetic poles; θ represents the circumferential angle, 0°<θ<360°.

[0056] In this embodiment, the outer diameter of the original magnetic ring is R1 = 18.5 mm, R2 = 15.8 mm, and the number of magnetic poles is n = 6. According to the first functionalized outer diameter formula:

[0057] R0=(R1-H)+H×cos(nθ)=(18.5-H)+H×cos(6θ)

[0058] At the same time, ensure that R1-2H > R2, that is, 18.5mm-2H > 15.8mm, H < 1.35mm.

[0059] Verification was conducted using parametric finite element simulation. In existing finite element software, the value of H was directly set to 0mm, 0.1mm, 0.2mm…1.3mm for parallel solution, obtaining the surface magnetic waveform and decomposing harmonics for each case. The results showed that the harmonic distortion rate of the surface magnetic waveform reached its lowest value when H = 0.6mm.

[0060] Therefore, the functionalized outer diameter R0 = 17.9 mm + 0.6 mm × cos(6θ), 0° < θ < 360°.

[0061] The cross-section and three-dimensional structure of the magnetic ring machined according to the above outer diameter are as follows: Figure 2 As shown in the figure, position 11 represents the main magnetic pole portion of each magnetic pole, and position 12 represents the transition position 12 between adjacent main magnetic poles. It can be seen that the magnetic ring has undergone thinning treatment at the transition position 12 according to the first functionalized outer diameter, in order to reduce the harmonics of the surface magnetic waveform and reduce torque pulsation.

[0062] Example 2

[0063] A type of functionalized magnetic ring with unequal outer diameter and thickness, such as Figure 6 , 7 As shown, the second optimized function for the outer diameter of unequal-thickness magnetic rings significantly reduces the higher harmonics of the surface magnetic waveform, while the fundamental amplitude is higher than that of the first function. The outer diameter satisfies the following:

[0064]

[0065] Where R0 is the optimized outer diameter of the magnetic ring; R1 is the original outer diameter of the magnetic ring; H is the pole clipping parameter, which satisfies: R1-2H>R2, R2 is the inner diameter of the magnetic ring; H is determined by parametric simulation; n is the number of magnetic poles; θ represents the circumferential angle, 0°<θ<360°.

[0066] In this embodiment, the outer diameter of the original magnetic ring is R1 = 18.5 mm, R2 = 15.8 mm, and the number of magnetic poles is n = 6. According to the second functionalized outer diameter formula:

[0067]

[0068] The function satisfies R1-2H>R2, i.e., 18.5mm-2H>15.8mm, H<1.35mm.

[0069] Verification was performed using parametric finite element simulation. When H = 0.9 mm, the harmonic distortion rate of the surface magnetic waveform reached its minimum value. Therefore, the functionalized outer diameter... 0° < θ < 360°.

[0070] Since the magnetic rings with the two outer diameter optimization functions use the same fundamental wave function, the maximum value of the outer diameter is the same. Magnetization can be performed using a magnetization fixture with the same structure, and only the position of the positioning plate needs to be adjusted.

[0071] Harmonics in the rotor surface flux density waveform have a significant impact on the torque ripple of permanent magnet motors. On one hand, the flux density waveform affects the magnitude of the cogging torque; on the other hand, harmonics (especially higher-order harmonics) in the flux density waveform cause corresponding harmonic components in the electromagnetic torque. These harmonics induce irregular torque fluctuations, leading to vibration and noise during motor operation, affecting the motor's smoothness and operating efficiency. Therefore, suppressing harmonic components in the flux density waveform, especially higher-order harmonics, is crucial for reducing torque ripple and improving motor performance during the design and operation of permanent magnet motors.

[0072] The functionalized outer diameter unequal thickness magnetic rings of Embodiments 1 and 2 of the present invention employ two functionalized outer diameters. By reducing the thickness of the magnetic pole transition region, the harmonic components of the magnetic surface magnetism are controlled, thereby reducing the amplitude of the cogging torque. A multi-pole magnetizing core with a matching magnetizing fixture can magnetize the magnetic ring into a surface with multiple alternating magnetic poles.

[0073] The two outer diameter functions mentioned above use the same clipping fundamental wave function cos(nθ). The difference is that the second clipping function adds a third harmonic cos(3nθ) to the first clipping function. Therefore, the fundamental wave amplitude of the second function is higher than that of the first function, and the motor output performance is better. However, due to the introduction of the third harmonic, the magnetic distortion rate is higher than that of the first function.

[0074] The unequal thickness magnetic ring structure of this invention has an outer diameter function that satisfies the first function R0=(R1-H)+H×cos(nθ), which can effectively reduce the high-order harmonics of the surface magnetic waveform. For example... Figure 1 The diagram showing the magnetic pole dimensions illustrates that when the thickness of a single magnetic pole (as shown by the dashed line) remains constant, the magnetic flux density at the sides of the pole is often higher than that at the center because it is easier for the pole to form a closed magnetic circuit with adjacent poles. Figure 8 As shown. The outer diameter function of this invention reduces the thickness on both sides of the magnetic pole, thereby reducing the magnetic flux on both sides of each magnetic pole, as... Figure 9 As shown, reducing the magnetic flux on both sides of each magnetic pole results in a higher magnetic flux density at the middle position, thus making the surface magnetic waveform closer to a sine wave and lowering the harmonic distortion rate. The second function introduces a third harmonic based on the first function. The interaction between the winding current and the third harmonic also generates torque, but the introduction of harmonics also increases the harmonic distortion rate, leading to motor vibration.

[0075] like Figure 8The diagram shows the surface magnetic waveforms of the original magnetic ring and the two unequal-thickness magnetic rings of this invention. The horizontal axis represents the angle of one revolution of the magnetic ring (0-360°), and the vertical axis represents the radial magnetic flux density of the surface. It can be seen that the surface magnetic waveform of the unequal-thickness magnetic ring of this invention is closer to a sine wave, which means that its higher harmonic content is lower than that of the ordinary magnetic ring. Figure 9 As shown Figure 1 The harmonic decomposition result of the waveform, where the horizontal axis represents the order of the harmonics and the vertical axis represents the amplitude of the harmonics of that order. Figure 9 In the harmonic order, black represents a common magnetic ring. Common magnetic rings mainly exhibit higher amplitudes at odd-numbered harmonics such as the 3rd, 5th, and 7th. After unequal thickness optimization, such as... Figure 9 As shown in the blue and red cases, the third harmonic is significantly reduced compared to the black case, and the fifth, seventh, and other odd-order harmonics are also reduced. It is worth noting that the reduction in higher harmonics is most pronounced with the unequal-thickness magnetic ring one according to the first optimization function. The unequal-thickness magnetic ring two according to the second optimization function has slightly higher higher harmonics than the first type, but both are significantly lower than those of a regular magnetic ring. The fundamental amplitude of the unequal-thickness magnetic ring two is higher than that of the unequal-thickness magnetic ring one.

[0076] Example 3

[0077] A type of magnetic ring with unequal outer diameter and thickness, as described in Example 1 or 2, differs in that, during manufacturing, the raw materials are first melted at high temperature by casting or smelting to form an alloy. The raw materials are selected from elements such as high-purity neodymium iron boron, and small amounts of other elements (such as dysprosium, cerium, etc.) are usually added to improve magnetic properties. After cooling, the alloy is crushed and ground to produce nanoscale powder. The nanoscale powder is mixed with a binder (epoxy resin) to obtain a mixture. The mixture is then shaped into a blank of the desired shape through processes such as pressing or injection molding. The shaped blank is cured at a specific temperature to fully cross-link the binder, enhancing the mechanical strength of the magnet. After post-processing and surface treatment, the final product is obtained.

[0078] Example 4

[0079] A method for magnetizing magnetic rings with unequal outer diameters and thicknesses, using a magnetizing fixture to complete the magnetization process, such as... Figures 3-5 As shown, the magnetizing fixture includes a base 5, a magnetizing core 3, a winding 4, and a positioning device 2. The winding 4 is made of enameled copper wire; the base 5 and the positioning device 2 are made of non-magnetic materials.

[0080] During magnetization, place the magnetic ring 1 on the magnetizing core 3 and fix it with the positioning device 2. Connect the two ends of the winding 4 to the positive and negative poles of the pulse power supply respectively, and then the magnetization can be carried out by powering on. After the power is turned off, remove the magnetic ring structure to complete the magnetization.

[0081] The base 5 has a groove for placing the magnet core 3, and a positioning post is set in the center of the groove for positioning the magnet core 3.

[0082] The magnetic core 3 is provided with through holes and winding grooves 32, the winding grooves 32 being used to install windings; a slot opening 31 is provided between the winding groove 32 and the through hole, and a magnetizing position 33 is formed between adjacent slot openings 31; the positioning device 2 includes a disk and positioning plates 21 evenly distributed around the circumference of the disk. The disk is placed in the through hole on the magnetic core, and the positioning plates 21 are engaged in the slot openings 31. The thickness of the slot openings 31 is consistent with that of the positioning plates 21 in the magnetic ring positioning device. Positioning the positioning plates 21 by engaging the slot openings is simple and convenient; the magnetic ring 1 is fitted inside the positioning device 2, wherein the transition position of the positioning plate corresponds to the transition position of the magnetic ring, which restricts the circumferential rotation of the magnetic ring. During assembly, the six positioning plates 21 are respectively positioned in the six slot openings 31. At this time, the transition position 12 of the magnetic ring is just restricted by the positioning plate and aligned with the slot opening, while the main magnetic pole part 11 of the magnetic ring is aligned with the magnetizing position 33.

[0083] The number of positioning plates is 6.

[0084] The positioning device can be fixed to the magnetized core using adhesive, and mass magnetization can be performed simply by replacing the magnetic ring.

[0085] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnetic ring with a functionalized outer diameter and unequal thickness, characterized in that, The inner diameter of the unequal thickness magnetic ring is circular, and the outer diameter is a variation curve. The thickness of the outer diameter remains constant in the main magnetic pole part and decreases at the transition position between adjacent main magnetic pole parts. The unequal thickness magnetic rings are made of bonded neodymium iron boron material; The outer diameter of the unequal-thickness magnetic ring satisfies: in, The optimized outer diameter of the magnetic ring; This is the original outer diameter of the magnetic ring; For the pole clipping parameters, satisfy: , This is the inner diameter of the magnetic ring; The number of magnetic poles; ; or, in, The optimized outer diameter of the magnetic ring; This is the original outer diameter of the magnetic ring; For the pole clipping parameters, satisfy: , This is the inner diameter of the magnetic ring; The number of magnetic poles; ; Determining the clipping parameters At that time, according to Limitations are set in finite element simulation. The range of values ​​is Set the value step size according to the solution requirements, and solve all possible solutions. Choose the value with the lowest magnetic harmonic distortion rate. The value is taken as the final result; A magnetization method for magnetic rings with unequal outer diameters and thicknesses using a magnetization fixture is employed. The magnetization fixture includes a base, a magnetizing core, a winding, and a positioning device. The winding is made of enameled copper wire, while the base and positioning device are made of non-magnetic materials. During magnetization, place the magnetic ring on the magnetizing core and fix it with a positioning device. Connect the two ends of the winding to the positive and negative terminals of the pulse power supply respectively, and then turn on the power to magnetize. After turning off the power, remove the magnetic ring structure to complete the magnetization. The base is provided with a groove for placing the charging magnet core, and a positioning post is provided in the center of the groove for positioning the charging magnet core. The magnetic core is provided with through holes and winding grooves, the winding grooves being used to install windings; a slot opening is provided between the winding groove and the through hole, and a magnetic position is formed between adjacent slot openings; the positioning device includes a disk and positioning plates evenly distributed around the circumference of the disk, the disk being placed in the through hole on the magnetic core, and the positioning plates being engaged in the slot openings; the magnetic ring is sleeved inside the positioning device, wherein the transition position of the positioning plate and the magnetic ring corresponds, thereby restricting the circumferential rotation of the magnetic ring.

2. The functionalized outer diameter unequal thickness magnetic ring according to claim 1, characterized in that, In the manufacturing process, the raw materials are first melted at high temperature through casting or smelting to form an alloy. After the alloy is cooled, it is crushed and ground to produce nano-sized powder. The nano-sized powder is mixed with a binder to obtain a mixture. The mixture is then shaped into a blank of the desired shape through pressing or injection molding. The shaped blank is then cured to allow the binder to fully cross-link, enhancing the mechanical strength of the magnet. After post-processing and surface treatment, the final product is obtained.

3. The functionalized outer diameter unequal thickness magnetic ring according to claim 2, characterized in that, The adhesive is epoxy resin or polyurethane.

4. The functionalized outer diameter unequal thickness magnetic ring according to claim 3, characterized in that, The number of positioning plates is the same as the number of magnetic poles.

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