Permanent magnet ring V-shaped asymmetric skewed pole magnetizing clamp and using method thereof

Abstract

The invention discloses a permanent magnet ring V-shaped asymmetric skewed pole magnetizing clamp and a using method thereof, and relates to the technical field of motor magnetizing. The invention aims to solve the problems of large bearing wear and poor harmonic suppression effect in the existing method for realizing the integral skewed pole. A magnetizing clamp inner yoke and a magnetizing clamp outer yoke can be coaxially connected to the inner side and the outer side of a permanent magnet ring to be magnetized in a sleeving mode correspondingly, and the number of pole heads of the magnetizing clamp inner yoke and the number of pole heads of the magnetizing clamp outer yoke are the same as the number of poles of the permanent magnet ring; coils with the same number of turns are wound on the pole heads of the magnetizing clamp inner yoke and the magnetizing clamp outer yoke, the winding directions of the coils on the adjacent pole heads are opposite, and the coils on all the pole heads are connected in series; the axial length of the magnetizing clamp inner yoke and the axial length of the magnetizing clamp outer yoke meet the requirement.

Description

Technical Field

[0001] This application belongs to the field of motor magnetization technology, and particularly relates to magnetization clamps. Background Technology

[0002] Permanent magnet motors, due to their high power density, high efficiency, and excellent dynamic performance, have been widely used in new energy vehicles, industrial servo systems, home appliances, and aerospace. Among them, surface-mounted permanent magnet synchronous motors, employing a permanent magnet ring structure, have become one of the mainstream technical solutions due to their advantages such as simple structure, low manufacturing cost, and stable torque output. However, as the performance requirements of applications continue to increase, the inherent technical defects of traditional radially magnetized permanent magnet rings are becoming increasingly prominent. One of the most prominent problems is torque ripple. Torque ripple leads to noise and vibration during motor operation, seriously affecting the control accuracy, stability, and user experience of the system.

[0003] To suppress torque pulsation, "skewed pole" technology is widely used. This involves offsetting the stator core or rotor permanent magnets axially at a certain angle to reduce cogging torque and torque pulsation caused by stator slotting and back EMF harmonics. Currently, the mainstream process for achieving skewed poles in permanent magnet rings is "segmented skew," which involves dividing a single permanent magnet ring axially into multiple independent magnetic rings, twisting each ring at an angle before assembling them. While effective, this method has significant drawbacks: The process is complex and costly: it requires the fabrication of multiple independent magnetic rings and involves several assembly steps such as precise positioning, twisting and bonding, resulting in low production efficiency. Mechanical strength and reliability issues: The adhesive interface is subjected to huge centrifugal stress when the motor rotates at high speed, which poses a risk of debonding and structural failure, affecting the reliability of the motor; Performance is not ideal: Segmented slant poles are essentially a discretized approximation of continuous slant poles, which has limited effect on suppressing torque ripple and may introduce new harmonics.

[0004] While unidirectional continuous slant magnetization is an ideal method for achieving integral slant magnetization, it does have some significant drawbacks. First, it generates a huge axial electromagnetic force, which significantly increases bearing wear, shortens its service life, and may generate additional mechanical noise. Second, the fixed angle of unidirectional continuous slant magnetization is optimized for one or more major harmonics, but may not be effective in suppressing other minor and asymmetric harmonics, resulting in residual torque pulsation and noise. Summary of the Invention

[0005] This application aims to address the problems of high bearing wear and poor harmonic suppression in existing methods for achieving integral skewed poles. It provides a permanent magnet ring V-shaped asymmetric skewed pole magnetizing fixture and its usage method.

[0006] The first aspect of this application provides a permanent magnet ring V-shaped asymmetric skew pole magnetizing clamp, comprising: an inner yoke of the magnetizing clamp and an outer yoke of the magnetizing clamp;

[0007] The inner yoke of the magnetizing clamp includes a left oblique inner yoke and a right oblique inner yoke fixedly arranged coaxially along the axial direction, and an inner yoke magnetic isolation ring is provided between the left oblique inner yoke and the right oblique inner yoke; the outer yoke of the magnetizing clamp includes a left oblique outer yoke and a right oblique outer yoke fixedly arranged coaxially along the axial direction, and an outer yoke magnetic isolation ring is provided between the left oblique outer yoke and the right oblique outer yoke; the inner yoke and the outer yoke of the magnetizing clamp can be coaxially sleeved on the inner and outer sides of the permanent magnet ring to be magnetized, respectively, and the number of poles of the inner yoke and the outer yoke of the magnetizing clamp are the same as the number of poles of the permanent magnet ring;

[0008] The inner yoke of the magnetizing clamp and each pole of the outer yoke of the magnetizing clamp are wound with a coil of the same number of turns, and the coils on adjacent poles are wound in opposite directions, and the coils on all poles are connected in series.

[0009] The axial lengths of the inner yoke and outer yoke of the magnetizing clamp satisfy the following: , and These are the axial lengths of the inner yoke and the outer yoke of the magnetizing clamp, respectively. This is the axial length of the permanent magnet ring.

[0010] In one possible design, the aforementioned permanent magnet ring V-shaped asymmetric inclined pole magnetizing fixture further includes: an upper mold sleeve and a lower mold sleeve;

[0011] The upper and lower mold sleeves are used to clamp the inner yoke of the magnetizing fixture, the permanent magnet ring, and the outer yoke of the magnetizing fixture, which are coaxially nested from the inside to the outside. The upper and lower mold sleeves are connected to each other by connecting bolts.

[0012] In one possible design, the upper mold sleeve is fixedly connected to one end of the outer yoke of the magnetizing fixture, and the lower mold sleeve is fixedly connected to one end of the inner yoke of the magnetizing fixture.

[0013] In one possible design, the coil is surrounded by a high-temperature resistant insulating adhesive.

[0014] In one possible design, the axial thickness of both the inner and outer yoke magnetic isolation rings is 1mm to 3mm.

[0015] In one possible design, cooling holes are provided on the inner yoke of the magnetizing fixture, the outer yoke of the magnetizing fixture, the upper mold sleeve, and the lower mold sleeve, and the cooling holes are used to pass through the cooling pipe.

[0016] The second aspect of this application provides a method for using the aforementioned permanent magnet ring V-shaped asymmetric skew pole magnetizing clamp, including:

[0017] The inner yoke, permanent magnet ring, and outer yoke of the magnetizing clamp are coaxially fixed from the inside to the outside, and the midpoints of the inner yoke, permanent magnet ring, and outer yoke of the magnetizing clamp are coplanar. There are gaps between the inner yoke and the permanent magnet ring, and between the permanent magnet ring and the outer yoke of the magnetizing clamp. The pole head tilt angles of the inner yoke and the outer yoke of the magnetizing clamp are exactly the same as the tilting portions of the corresponding permanent magnet rings.

[0018] The upper mold sleeve is fixed to one end of the outer yoke of the magnetizing clamp, the magnetizing pad is fixed to one end of the inner yoke of the magnetizing clamp away from the upper mold sleeve, and the lower mold sleeve is fixed to the free end of the magnetizing pad. The upper mold sleeve and the lower mold sleeve are connected to each other by connecting bolts, so that the inner yoke of the magnetizing clamp, the permanent magnet ring and the outer yoke of the magnetizing clamp are clamped between the upper mold sleeve and the lower mold sleeve.

[0019] Connecting the series-connected coils to a power source creates an alternating polarity pulsed magnetic field around the outer circumference of the permanent magnet ring, thereby magnetizing the permanent magnet ring.

[0020] In one possible design, cooling holes are provided on the inner yoke, outer yoke, upper mold sleeve, and lower mold sleeve of the magnetizing fixture, and cooling pipes are installed in the cooling holes to cool the magnetizing fixture.

[0021] The beneficial effects of this application are:

[0022] 1. Uniform Saturation Magnetization of the Permanent Magnet Ring: Due to the coaxial and unidirectional excitation of the inner and outer yokes and the axial continuity of the yoke body, the excitation energy is highly concentrated in the permanent magnet ring blank. This creates a strong, uniform, and consistent composite magnetic field throughout the entire internal space of the permanent magnet ring blank (including both axial ends and the radial section). This ensures that the permanent magnet ring is instantly and fully saturated with magnetization, effectively eliminating the magnetization angle deviation or uneven magnetization caused by the magnetic field attenuation of traditional unilateral excitation magnetization. This results in good consistency and reliable performance for mass-produced products. The axial continuity of the yoke body overcomes the magnetic field distortion problem of discontinuous fixtures, ensuring that the magnetic ring is synchronously and uniformly magnetized to saturation from the inside out and from one end to the other.

[0023] 2. High-precision magnetization in the transition zone: At the transition point of the V-shaped inclined poles, traditional magnetization methods are prone to mutual interference. This invention innovatively introduces a magnetic isolation ring, which acts as a magnetic potential barrier, physically isolating the left and right inclined magnetization magnetic fields, thus preventing interference. This is the core guarantee for achieving a clear and sharp angle transition and avoiding ambiguity in the magnetic field during the transition zone.

[0024] 3. Elimination of end effects: The clamp height is twice that of the permanent magnet ring, perfectly eliminating end distortion of the magnetic field. This ensures that the magnetization accuracy of the two end faces of the magnetic ring is completely consistent with that of the middle, solving the industry-wide common problem of insufficient end magnetization of thin magnetic rings. Attached Figure Description

[0025] Figure 1 A schematic diagram of an asymmetric skewed pole magnetization structure for a permanent magnet ring;

[0026] Figure 2 Axial sectional view of a V-shaped asymmetric inclined pole magnetizing fixture for permanent magnet rings;

[0027] Figure 3 Exploded view of a V-shaped asymmetric tilted pole magnetizing fixture for permanent magnet rings;

[0028] Figure 4 A schematic diagram of the nested structure of the inner and outer yokes of the magnetizing clamp;

[0029] In the diagram, 1-Permanent magnet ring; 1-1-Right slanted section; 1-2-Left slanted section; 2-Inner yoke of magnetizing fixture; 2.1-Left slanted inner yoke; 2.2-Right slanted inner yoke; 2.3-Magnetic isolation ring of inner yoke; 2.4-Connecting screw of inner yoke; 2.5-Magnetic coil of inner yoke; 3-Outer yoke of magnetizing fixture; 3.1-Left slanted outer yoke; 3.2-Right slanted outer yoke; 3.3-Magnetic isolation ring of outer yoke; 3.4-Connecting screw of outer yoke; 3.5-Magnetic coil of outer yoke; 4.1-Upper mold sleeve; 4.2-Lower mold sleeve; 4.3-Screw of upper mold sleeve; 4.4-Connecting bolt; 5-Cooling pipe; 6-Magnetic pad. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0031] The patent document with publication number CN120319569A explored a magnetizing fixture for a V-shaped symmetrical oblique pole permanent magnet ring. However, during the magnetizing process, the magnetic field of the magnetizing fixture at any point on the permanent magnet ring blank is provided by the excitation coil on one side (or the inner yoke, or the outer yoke). Essentially, it is based on the traditional "single-sided excitation" mode and performs alternating excitation. It only integrates the functions of the inner and outer yokes into one fixture through mechanical structure.

[0032] In the patent document with publication number CN120319569A, the inner and outer yokes of the clamp are not continuous structures in the axial direction and are not magnetically shielded. There will inevitably be magnetic field distortion at the interruption point, making it difficult to guarantee the linear transition and accuracy of the slant pole angle.

[0033] The patent document with publication number CN120319569A shows that the height of the outer yoke of the magnetizing clamp is less than the height of the permanent magnet ring, and the height of the inner yoke is equal to the height of the permanent magnet ring. This mode makes it difficult to form a sufficiently uniform and strong saturation magnetic field on the entire inner and outer surfaces of the magnetic ring, especially at both ends of the axial direction. This may lead to insufficient magnetization or angular deviation. In particular, its guarantee capability is limited for the precise magnetization required for high-performance asymmetric skew poles.

[0034] In the patent document with publication number CN120319569A, the magnetizing clamp did not make any treatment at the turning point of the V-shaped inclined pole. This would cause the magnetizing magnetic fields of the two inclinations to interfere with each other and produce distortion, thus affecting the magnetizing effect.

[0035] Therefore, there is an urgent need for an innovative V-shaped permanent magnet ring magnetizing fixture structure design that can generate a powerful excitation magnetic field that is coordinated internally and externally, uniformly saturated, highly accurate, and free from interference at angle transitions. This would break through the performance bottleneck of traditional single-sided magnetization and provide core technical support for the next generation of ultra-quiet, low-vibration, and high-performance permanent magnet motors.

[0036] Specific implementation method one: Refer to Figures 2 to 4 This embodiment is described in detail to address the aforementioned problems. The permanent magnet ring V-shaped asymmetric skew pole magnetizing clamp described in this embodiment includes: a permanent magnet ring V-shaped asymmetric skew pole magnetizing clamp, comprising: an inner yoke and an outer yoke;

[0037] The inner yoke of the magnetizing clamp includes a left oblique inner yoke and a right oblique inner yoke fixedly arranged coaxially along the axial direction, and an inner yoke magnetic isolation ring is provided between the left oblique inner yoke and the right oblique inner yoke; the outer yoke of the magnetizing clamp includes a left oblique outer yoke and a right oblique outer yoke fixedly arranged coaxially along the axial direction, and an outer yoke magnetic isolation ring is provided between the left oblique outer yoke and the right oblique outer yoke; the inner yoke and the outer yoke of the magnetizing clamp can be coaxially sleeved on the inner and outer sides of the permanent magnet ring to be magnetized, respectively, and the number of poles of the inner yoke and the outer yoke of the magnetizing clamp are the same as the number of poles of the permanent magnet ring;

[0038] The inner yoke of the magnetizing clamp and each pole of the outer yoke of the magnetizing clamp are wound with a coil of the same number of turns, and the coils on adjacent poles are wound in opposite directions, and the coils on all poles are connected in series.

[0039] The axial lengths of the inner yoke and outer yoke of the magnetizing clamp satisfy the following: , and These are the axial lengths of the inner yoke and the outer yoke of the magnetizing clamp, respectively. This is the axial length of the permanent magnet ring.

[0040] In one embodiment, the aforementioned permanent magnet ring V-shaped asymmetric inclined pole magnetizing fixture further includes: an upper mold sleeve and a lower mold sleeve;

[0041] The upper die sleeve and the lower die sleeve are used to clamp both ends of the inner yoke of the magnetizing fixture, the permanent magnet ring, and the outer yoke of the magnetizing fixture, which are coaxially nested in sequence from the inside to the outside, and the upper die sleeve and the lower die sleeve are connected to each other by connecting bolts.

[0042] In one embodiment, the upper die sleeve is fixedly connected to one end of the outer yoke of the magnetizing fixture, and the lower die sleeve is fixedly connected to one end of the inner yoke of the magnetizing fixture.

[0043] In one embodiment, the coil is coated with high-temperature resistant insulating glue.

[0044] In one embodiment, the axial thicknesses of both the inner yoke magnetic isolation ring and the outer yoke magnetic isolation ring are 1 mm to 3 mm.

[0045] In one embodiment, cooling holes are provided on the inner yoke of the magnetizing fixture, the outer yoke of the magnetizing fixture, the upper die sleeve, and the lower die sleeve, and the cooling holes are used to penetrate cooling pipes.

[0046] To further introduce the solutions of the embodiments of the present application, Figures 2 to 4 An embodiment is provided.

[0047] As Figure 1 shown, the asymmetric V-shaped inclined pole magnetizing structure is axially divided into two parts, namely the left inclined part 1-2 and the right inclined part 1-1. The magnetizing direction of the left inclined part 1-2 is offset to the left by an angle α (with a value of 10°) relative to the radial direction of the rotor, and the magnetizing direction of the right inclined part 1-1 is offset to the right by an angle β (with a value of 30°) relative to the radial direction of the rotor, and , thus forming an asymmetric V-shaped inclined pole structure. The angle value ranges of both α and β are 5 degrees to 30 degrees, and the absolute value of the difference between the two , and the number of pole pairs of the permanent magnet ring is 1 to 23. In this embodiment, , , the material is sintered neodymium iron boron with the grade of N48H, and the number of pole pairs is 2.

[0048] The magnetizing fixture structure supporting the above asymmetric inclined pole magnetizing structure is as Figures 2-4 shown, and includes an inner yoke 2 of the magnetizing fixture, an outer yoke 3 of the magnetizing fixture, a die sleeve, a cooling pipe 5, and a magnetizing spacer 6.

[0049] The inner yoke 2 of the magnetizing fixture includes: a left inclined inner yoke 2.1, a right inclined inner yoke 2.2, an inner yoke magnetic isolation ring 2.3, inner yoke connecting screws 2.4, and an inner yoke magnetizing coil 2.5.

[0050] The outer yoke 3 of the magnetizing fixture includes: a left inclined outer yoke 3.1, a right inclined outer yoke 3.2, an outer yoke magnetic isolation ring 3.3, outer yoke connecting screws 3.4, and an outer yoke magnetizing coil 3.5.

[0051] The mold sleeve includes: upper mold sleeve 4.1, lower mold sleeve 4.2, upper mold sleeve screw 4.3, and connecting bolt 4.4.

[0052] The mold sleeve is used to fix the permanent magnet ring 1, the inner yoke 2 of the magnetizing clamp, and the outer yoke 3 of the magnetizing clamp. Specifically, the outer yoke 3 of the magnetizing clamp is connected to the upper mold sleeve 4.1 with the upper mold sleeve screw 4.3. The inner yoke 2 of the magnetizing clamp is connected to the lower mold sleeve 4.2 after being potted and cured with thermally conductive adhesive. The upper and lower mold sleeves are connected by connecting bolts 4.4.

[0053] Both the left oblique inner yoke 2.1 and the right oblique inner yoke 2.2 are structures with multiple poles on the outside, made of industrial pure iron. The number of poles is equal to the number of poles in the permanent magnet ring 1 (4 in this embodiment). To prevent the magnetic fields of the two parts from interfering with each other during magnetization, an inner yoke magnetic isolation ring 2.3 is placed between the left oblique inner yoke 2.1 and the right oblique inner yoke 2.2. Then, the left oblique inner yoke 2.2, the right oblique inner yoke 2.2, and the inner yoke magnetic isolation ring 2.3 are connected together by inner yoke connecting screws 2.4. Similarly, both the left oblique outer yoke 3.1 and the right oblique outer yoke 3.2 are structures with multiple poles on the inside, made of industrial pure iron. The number of poles is also equal to the number of poles in the permanent magnet ring 1 (4 in this embodiment). To prevent the magnetic fields of the two parts from interfering with each other during magnetization, an outer yoke magnetic isolation ring 3.4 is placed between the left oblique outer yoke 3.1 and the right oblique outer yoke 3.2. Then, the left oblique outer yoke 3.1, the right oblique outer yoke 3.2, and the inner yoke magnetic isolation ring 3.3 are connected together by the outer yoke connecting screw 3.4. To prevent the magnetic pole distance between the left oblique part 1-2 and the right oblique part 1-1 from being too large, both the inner yoke magnetic isolation ring 2.3 and the outer yoke magnetic isolation ring 3.3 should not be too thick, and should be between 1mm and 3mm. In this embodiment, both the inner yoke magnetic isolation ring 2.3 and the outer yoke magnetic isolation ring 3.3 are 1mm thick.

[0054] The angles of the pole heads of the inner yoke 2 and the outer yoke 3 of the magnetizing clamp should be respectively the same as those of the inner yoke 2 and the outer yoke 3 of the magnetizing clamp. Figure 1 The left oblique portion 1-2 and the right oblique portion 1-1 shown have the same angle. After connection, the inner yoke 2 of the magnetizing clamp and the outer yoke 3 of the magnetizing clamp are wound with the same number of turns of copper inner yoke magnetizing coil 2.5 and outer yoke magnetizing coil 3.5 on each pole, and the winding direction of adjacent poles is opposite. They are connected in series and then connected to the capacitor magnetizing power supply.

[0055] The inner yoke magnetizing coil 2.5 and the outer yoke magnetizing coil 3.5 are surrounded by high-temperature resistant, high-strength insulating adhesive, which serves both curing and insulation purposes. The gaps between the permanent magnet ring 1 and the inner yoke 2 and outer yoke 3 of the magnetizing fixture should be as small as possible while ensuring the permanent magnet ring 1 can freely enter and exit the fixture. Furthermore, the permanent magnet ring 1 should be coaxial with the inner yoke 2 and outer yoke 3 of the magnetizing fixture to prevent uneven distribution of air gaps on the inner and outer sides of the permanent magnet ring 1, which would cause inconsistent magnetization effects on the poles of the permanent magnet ring 1. Simultaneously, to avoid the edge effects of the magnetizing fixture and coils affecting the magnetization effect, the axial lengths of the inner and outer yokes of the magnetizing fixture are set as follows: , and These are the axial lengths of the inner yoke 2 and the outer yoke 3 of the magnetizing clamp, respectively. This is the axial length of the permanent magnet ring 1. During magnetization, the permanent magnet ring 1 is placed on the magnetization pad 6. To ensure continuous operation and prevent coil temperature rise, cooling holes are provided in the inner yoke 2, outer yoke 3, and mold sleeve of the magnetization fixture, and cooling pipes 5 are installed inside them for cooling.

[0056] This embodiment addresses key challenges in V-shaped asymmetric skew pole magnetization, such as magnetic field attenuation, poor uniformity, and magnetic field distortion in the angle transition region, through the design of coaxial and unidirectional excitation of the inner and outer yokes of the magnetizing clamp, continuous yoke, magnetic field isolation, and spatial enhancement.

[0057] Specific Implementation Method Two: This implementation method is a method of using the permanent magnet ring V-shaped asymmetric tilting pole magnetizing fixture described in Specific Implementation Method One, including:

[0058] The inner yoke, permanent magnet ring, and outer yoke of the magnetizing clamp are coaxially fixed from the inside to the outside, and the midpoints of the inner yoke, permanent magnet ring, and outer yoke of the magnetizing clamp are coplanar. There are gaps between the inner yoke and the permanent magnet ring, and between the permanent magnet ring and the outer yoke of the magnetizing clamp. The pole head tilt angles of the inner yoke and the outer yoke of the magnetizing clamp are exactly the same as the tilting portions of the corresponding permanent magnet rings.

[0059] The upper mold sleeve is fixed to one end of the outer yoke of the magnetizing clamp, the magnetizing pad is fixed to one end of the inner yoke of the magnetizing clamp away from the upper mold sleeve, and the lower mold sleeve is fixed to the free end of the magnetizing pad. The upper mold sleeve and the lower mold sleeve are connected to each other by connecting bolts, so that the inner yoke of the magnetizing clamp, the permanent magnet ring and the outer yoke of the magnetizing clamp are clamped between the upper mold sleeve and the lower mold sleeve.

[0060] Connecting the series-connected coils to a power source creates an alternating polarity pulsed magnetic field around the outer circumference of the permanent magnet ring, thereby magnetizing the permanent magnet ring.

[0061] In one embodiment, cooling holes are provided on the inner yoke, outer yoke, upper mold sleeve, and lower mold sleeve of the magnetizing fixture, and cooling pipes are provided in the cooling holes to cool the magnetizing fixture.

[0062] Example

[0063] Before magnetization, first unscrew the connecting bolt 4.3 on the mold sleeve, remove the upper mold sleeve 4.1, and then put the permanent magnet ring 1 to be magnetized on the outer surface of the inner yoke 2 of the magnetization fixture. Align the inner yoke 2 of the magnetization fixture with the opposite winding direction of the outer yoke 3 of the magnetization fixture, so that the permanent magnet ring 1 is placed between the inner yoke 2 and the outer yoke 3 of the magnetization fixture. Then close the mold sleeve and tighten the bolt 4.3.

[0064] When the power is turned on and a discharge occurs, an alternating N, S, N, S pulsed magnetic field will be formed on the outer circumference of the permanent magnet ring 1, which will magnetize the permanent magnet ring 1, thus enabling magnetization. After magnetization is complete, the mold sleeve is opened.

[0065] While specific embodiments of this application have been described herein with reference to them, it should be understood that these embodiments are merely examples of the principles and applications of this application. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of this application as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. Permanent magnet ring V-shaped asymmetric skew-pole magnetizing fixture, characterized in that, The magnetizing fixture comprises: a magnetizing fixture inner yoke and a magnetizing fixture outer yoke; the magnetizing fixture inner yoke comprises a left inclined inner yoke and a right inclined inner yoke arranged coaxially and fixedly along the axial direction, and a inner yoke magnetic separation ring is arranged between the left inclined inner yoke and the right inclined inner yoke; the magnetizing fixture outer yoke comprises a left inclined outer yoke and a right inclined outer yoke arranged coaxially and fixedly along the axial direction, and a outer yoke magnetic separation ring is arranged between the left inclined outer yoke and the right inclined outer yoke; the magnetizing fixture inner yoke and the magnetizing fixture outer yoke can be coaxially sleeved on the inner side and the outer side of the permanent magnet ring to be magnetized respectively, and the number of pole heads of the magnetizing fixture inner yoke and the magnetizing fixture outer yoke is the same as the number of poles of the permanent magnet ring; the same number of turns of coils are wound on each pole head of the magnetizing fixture inner yoke and the magnetizing fixture outer yoke, the winding directions of the coils on adjacent pole heads are opposite, and the coils on all pole heads are connected in series; The axial length of the magnetizing fixture inner yoke and the magnetizing fixture outer yoke satisfies , and are the axial lengths of the magnetizing fixture inner yoke and the magnetizing fixture outer yoke, respectively, is the axial length of the permanent magnet ring.

2. The permanent magnet ring V-shaped asymmetric canted pole magnetization fixture of claim 1, wherein, The magnetizing fixture further comprises: an upper die sleeve and a lower die sleeve; the upper die sleeve and the lower die sleeve are used for clamping the two ends of the magnetizing fixture inner yoke, the permanent magnet ring and the magnetizing fixture outer yoke which are coaxially nested from inside to outside, and the upper die sleeve and the lower die sleeve are connected by connecting bolts.

3. The permanent magnet ring V-shaped asymmetric canted pole magnetization fixture of claim 2, wherein, The upper die sleeve is fixedly connected with one end of the magnetizing fixture outer yoke, and the lower die sleeve is fixedly connected with one end of the magnetizing fixture inner yoke.

4. The permanent magnet ring V-shaped asymmetric canted pole magnetization fixture of claim 1, wherein, The coils are coated with high-temperature resistant insulating glue.

5. The permanent magnet ring V-shaped non-symmetrical canted pole magnetization fixture of claim 1, wherein, The axial thickness of the inner yoke magnetic separation ring and the outer yoke magnetic separation ring is 1mm-3mm.

6. The permanent magnet ring V-shaped non-symmetrical canted pole magnetization fixture of claim 2, wherein, Cooling holes are formed on the magnetizing fixture inner yoke, the magnetizing fixture outer yoke, the upper die sleeve and the lower die sleeve, and cooling pipes are arranged in the cooling holes.

7. A method of using the V-shaped asymmetric skew field magnetizing fixture of permanent magnet ring of any one of claims 2 to 5, characterized in that, The magnetizing fixture comprises: the magnetizing fixture inner yoke, the permanent magnet ring and the magnetizing fixture outer yoke are coaxially embedded from inside to outside, and the midpoints of the magnetizing fixture inner yoke, the permanent magnet ring and the magnetizing fixture outer yoke are coplanar, there are gaps between the magnetizing fixture inner yoke and the permanent magnet ring and between the permanent magnet ring and the magnetizing fixture outer yoke, and the inclination angles of the pole heads of the magnetizing fixture inner yoke and the magnetizing fixture outer yoke are completely the same as the inclination angles of the corresponding inclined parts of the permanent magnet ring; the upper die sleeve is fixed on one end of the magnetizing fixture outer yoke, the magnetizing pad is fixed on the end of the magnetizing fixture inner yoke away from the upper die sleeve, the lower die sleeve is fixed on the free end of the magnetizing pad, and the upper die sleeve and the lower die sleeve are connected by connecting bolts, so that the magnetizing fixture inner yoke, the permanent magnet ring and the magnetizing fixture outer yoke are clamped between the upper die sleeve and the lower die sleeve; the coils connected in series are connected to a power supply, so that the outer circumference of the permanent magnet ring forms a pulse magnetic field with alternating polarity, and the permanent magnet ring is magnetized.

8. The method of using a permanent magnet ring V-shaped asymmetric canted pole magnetization fixture of claim 7, wherein, Cooling holes are formed on the magnetizing fixture inner yoke, the magnetizing fixture outer yoke, the upper die sleeve and the lower die sleeve, and cooling pipes are arranged in the cooling holes, so as to cool the magnetizing fixture.

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