Halbach array permanent magnet rotor and electric machine

Abstract

The application discloses a Halbach array permanent magnet rotor and a motor. The permanent magnet rotor comprises a plurality of rotor units arranged in a circumferential array, wherein the rotor units comprise a rotor core assembly and a permanent magnet assembly which are connected to each other in cooperation; the permanent magnet assembly comprises a radial permanent magnet and a tangential permanent magnet group; the tangential permanent magnet group comprises a plurality of tangential permanent magnets arranged in a circumferential direction; the rotor core assembly and the plurality of tangential permanent magnets are located on one side of the radial permanent magnet in the circumferential direction; and the magnetization directions of the plurality of tangential permanent magnets are all different. The rotor core assembly comprises an inner core located on an inner side of the tangential permanent magnet in a radial direction and an outer core located on an outer side of the tangential permanent magnet. The design can improve the performance of the permanent magnet rotor.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a Halbach array permanent magnet rotor and motor. Background Technology

[0002] Permanent magnet motors, with their advantages of high efficiency, high power density, and high reliability, are widely used in many fields such as electric vehicles, wind power generation, aerospace, and home appliances. In low-speed, high-torque applications such as wind power generation, direct-drive systems can eliminate the gearbox, thereby directly eliminating the noise and faults caused by gear transmission and further improving the efficiency and reliability of the motor system.

[0003] Meanwhile, direct-drive systems place higher demands on the torque density of permanent magnet motors. Converting a traditional permanent magnet motor to a direct-drive system with the aim of increasing torque density typically requires increasing the number of pole pairs in the rotor's permanent magnets. However, this exacerbates inter-pole leakage, leading to a significant decrease in permanent magnet utilization. Traditional radially magnetized permanent magnet rotor structures, i.e., surface-mounted permanent magnet rotor structures, while possessing advantages such as high power density, simple pole structure, and good control performance, suffer from weak magnetization and low permanent magnet utilization, thus limiting the improvement of motor torque density. Traditional radially magnetized permanent magnet rotor structures, i.e., Spoke (wheel) type rotor structures, while enhancing the magnetization effect, still suffer from significant inter-pole leakage, similarly hindering torque density improvement.

[0004] Among the various structural forms of permanent magnet synchronous motors, the Halbach permanent magnet array has become a current research hotspot due to its unique magnetic field distribution characteristics. Summary of the Invention

[0005] This application provides a Halbach array permanent magnet rotor and motor, which can be used to improve motor performance.

[0006] The first aspect of this application provides a Halbach array permanent magnet rotor, the permanent magnet rotor comprising: a plurality of rotor units arranged in a circumferential array, each rotor unit comprising a rotor core assembly and a permanent magnet assembly connected to each other; the permanent magnet assembly comprising a radial permanent magnet and a tangential permanent magnet group, the tangential permanent magnet group comprising a plurality of tangential permanent magnets arranged in a circumferential direction, the rotor core assembly and the plurality of tangential permanent magnets being located on one side of the radial permanent magnet in the circumferential direction, the magnetization directions of the plurality of tangential permanent magnets being different; the rotor core assembly comprising an inner core located radially inner to the tangential permanent magnet and an outer core located radially outer to the tangential permanent magnet.

[0007] In one embodiment, the inner core and the outer core are provided with first tenon grooves on both sides of the circumferential direction, and the radial permanent magnet is provided with first tenon teeth on both sides of the circumferential direction that cooperate with and connect with the first tenon grooves.

[0008] In one embodiment, the inner radius of the inner core is a first radius, the outer radius of the inner core is a second radius, the inner radius of the outer core is a third radius, and the outer radius of the outer core is a fourth radius. The ratio of the first radius to the second radius is equal to the ratio of the third radius to the fourth radius. The ratio of the first radius to the second radius is between 0.5 and 1. The difference between the ratio of the first radius to the second radius and the ratio of the first radius to the third radius does not exceed 0.1. The central angle corresponding to the rotor core assembly is between 5° and 15°.

[0009] In one embodiment, the outer core is provided with a second tenon tooth at its outer edge in the radial direction. The second tenon tooth is used to engage with a corresponding second tenon groove provided on the inner side of the housing. The outer surface of the second tenon tooth in the radial direction is an arc surface. The second included angle between the side of the second tenon tooth and the radial direction is between 30° and 60°. The radius of the arc surface is a fifth radius, and the ratio of the fourth radius to the fifth radius is between 0.95 and 1. And / or, the corner between the inner side of the inner core and the outer side of the outer core is a rounded corner with a sixth radius, and the corner between the outer side of the inner core and the inner side of the outer core is a rounded corner with a seventh radius, and the ratio of the seventh radius to the sixth radius is between 0. The first mortise and tenon joint has a bottom width of 5 to 0.7, a first mortise and tenon joint depth of 2, a first mortise and tenon joint width of 3, and a ratio of the second dimension to the third dimension between 0.3 and 0.5. The ratio of the third dimension to the difference between the second radius and the first radius is between 0.05 and 0.15. The ratio of the second dimension to the first dimension is between 0.2 and 0.3. The corners on both sides of the second mortise and tenon joint are rounded with a radius of the eighth radius, and the ratio of the eighth radius to the sixth radius is between 0.3 and 0.5. The corner of the first mortise and tenon joint is a rounded with a radius of the ninth radius, and the ratio of the ninth radius to the sixth radius is between 0.1 and 0.3.

[0010] In one embodiment, the radial dimension of the radial permanent magnet is a first height, and the difference between the outer radius of the outer core and the inner radius of the inner core is equal to the first height; the distance between the first tenon tooth near the outer side of the radial permanent magnet and the outer side of the radial permanent magnet is a first distance, the distance between the first tenon tooth near the inner side of the radial permanent magnet and the inner side of the radial permanent magnet is a first distance, and the ratio of the first distance to the first height is between 0.15 and 0.25; and / or, the corners on both sides of the radial permanent magnet are rounded.

[0011] In one embodiment, each radial permanent magnet is a rounded rectangle, and each tangential permanent magnet is a rounded tile; and / or, the magnetization direction of the radial permanent magnet is the circumferential direction, and the magnetization directions of any two adjacent radial permanent magnets are opposite; the tangential permanent magnet group includes three tangential permanent magnets with different magnetization directions, the middle tangential permanent magnet being magnetized radially, and the other two tangential permanent magnets being magnetized circumferentially.

[0012] In one embodiment, the radial dimension of the tangential permanent magnet is a first thickness, and the difference between the inner radius of the outer core and the outer radius of the inner core is equal to the first thickness; and / or, the central angle corresponding to the tangential permanent magnet group is a first included angle, the central angle corresponding to each tangential permanent magnet is a second included angle, the ratio of the second included angle to the first included angle is between 0.2 and 0.4, and the first included angle is between 3° and 8°; and / or, the corners of the tangential permanent magnet are rounded.

[0013] In one embodiment, the rotor core assembly includes a plurality of laminations arranged radially, the laminations being made of silicon steel sheets.

[0014] In one embodiment, the permanent magnet assembly is made of neodymium iron boron.

[0015] This application also provides an electric motor, which includes the Halbach array permanent magnet rotor described in any of the above embodiments.

[0016] Unlike existing technologies, the beneficial effects of this application are as follows: The permanent magnet rotor of this application adopts a Halbach array, which includes multiple rotor units arranged in a circumferential array. Each rotor unit includes a rotor core assembly and a permanent magnet assembly that are connected to each other. The permanent magnet assembly includes a radial permanent magnet and a tangential permanent magnet group. The tangential permanent magnet group includes multiple tangential permanent magnets arranged circumferentially. The rotor core assembly and the multiple tangential permanent magnets are located on one side of the radial permanent magnet in the circumferential direction. The magnetization directions of the multiple tangential permanent magnets are all different. The rotor core assembly includes an inner core located radially inside the tangential permanent magnets and an outer core located radially outside. Through the above design, on the one hand, the magnetic field strength on one side of the air gap magnetic field is significantly enhanced, while the magnetic field strength on the other side is weakened, thereby achieving a unilateral magnetic focusing effect; on the other hand, it effectively suppresses inter-pole leakage magnetic field, improves the utilization rate and torque density of permanent magnets, and thus improves the performance of the permanent magnet rotor. When used in permanent magnet motors, it can significantly improve the overall efficiency and power density of the motor. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of one embodiment of the permanent magnet rotor of this application; Figure 2 yes Figure 1 An enlarged schematic diagram of one embodiment of the local structure; Figure 3 yes Figure 2 A schematic diagram of one embodiment of the rotor core assembly; Figure 4 yes Figure 3 A schematic diagram showing the structural dimensions and angle markings of the rotor core assembly; Figure 5 yes Figure 2 A schematic diagram showing the structural dimensions of a radially oriented permanent magnet; Figure 6 yes Figure 2 A schematic diagram showing the structural dimensions and angle markings corresponding to the tangential permanent magnet assembly; Figure 7 This is a schematic diagram of the unloaded magnetic field lines of a local part of the Halbach array permanent magnet rotor of this application; Figure 8 This is a comparison diagram of the no-load back EMF of a traditional radial permanent magnet rotor and the Halbach array permanent magnet rotor of this application. Figure 9This is a torque comparison diagram between a traditional radial permanent magnet rotor and the Halbach array permanent magnet rotor of this invention. Detailed Implementation

[0018] 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 the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that the terms "first" and "second" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0020] See Figure 1 , Figure 1 This is a schematic diagram of one embodiment of the permanent magnet rotor of this application. Figure 2 yes Figure 1 The enlarged schematic diagram of a partial structure in this application provides a Halbach array permanent magnet rotor 10. The permanent magnet rotor 10 includes: a plurality of rotor units 10A arranged in a circumferential array, each rotor unit 10A including a rotor core assembly 100 and a permanent magnet assembly 200 connected to each other; the permanent magnet assembly 200 includes a radial permanent magnet 201 and a tangential permanent magnet group, the tangential permanent magnet group including a plurality of tangential permanent magnets 202 arranged in a circumferential direction, the rotor core assembly 100 and the plurality of tangential permanent magnets 202 being located on one side of the radial permanent magnet 201 in the circumferential direction, and the magnetization directions of the plurality of tangential permanent magnets 202 being different; the rotor core assembly 100 includes an inner core 101 located radially inside the tangential permanent magnets 202 and an outer core 102 located radially outside the tangential permanent magnets 202.

[0021] Specifically, multiple identical rotor units 10A are uniformly arrayed along the circumference of the permanent magnet rotor 10. The rotor units 10A are arranged at equal angular intervals, and the included angle between the centers of adjacent rotor units 10A is 360° / n (n is the total number of rotor units), ensuring a highly symmetrical magnetic field distribution. The permanent magnet rotor 10 has an overall ring structure, and the permanent magnet assemblies 200 of each rotor unit 10A are arranged in a continuous Halbach pattern in the circumferential direction. The rotor unit 10A includes a rotor core assembly 100 and a permanent magnet assembly 200 that are connected to each other. The permanent magnet assembly 200 includes a radial permanent magnet 201 and a tangential permanent magnet group. The radial permanent magnet 201 specifically refers to a permanent magnet that extends radially, and its radial dimension is larger than its circumferential dimension. The tangential permanent magnet group specifically refers to a permanent magnet group that extends circumferentially as a whole, and its overall radial dimension is smaller than its circumferential dimension. Furthermore, in the radial direction, the size of the radial permanent magnet 201 is larger than the size of the tangential permanent magnet group; in the circumferential direction, the size of the radial permanent magnet 201 is smaller than the size of the tangential permanent magnet group. Here, circumferential refers to the circumferential direction of the permanent magnet rotor 10, that is, the tangential direction around the rotation axis of the permanent magnet rotor 10, and radial refers to the direction perpendicular to the rotation axis and pointing towards or away from the axis. This scheme adopts a continuous Halbach arrangement in the circumferential direction to enhance the magnetic field strength on one side of the air gap magnetic field and significantly weaken the magnetic field strength on the other side.

[0022] Furthermore, a tangential permanent magnet assembly includes multiple tangential permanent magnets 202 arranged circumferentially. For example, the number of tangential permanent magnets 202 can be 3, 5, or 7, etc. The magnetization directions of the multiple tangential permanent magnets 202 are all different. By non-uniformly and non-uniformly modulating the magnetic field direction in the tangential permanent magnet assembly, the focusing accuracy of the air gap magnetic field is improved, the waveform of the air gap magnetic field is optimized, and leakage magnetic loss is further reduced, thereby improving the motor's operating efficiency and power density. This solution further provides an inner iron core 101 and an outer iron core 102 on the inner and outer sides of the tangential permanent magnet assembly, respectively. The two work together to guide the magnetic circuit direction, thereby increasing the air gap magnetic flux density and reducing leakage magnetic loss. In summary, the design of this application can improve the performance of the permanent magnet rotor.

[0023] In one embodiment, combined with Figure 2 and Figure 3 , Figure 3 yes Figure 2 A schematic diagram of one embodiment of the rotor core assembly shows that the inner core 101 and the outer core 102 are provided with first tenon grooves A on both sides of the circumference, and the radial permanent magnet 201 is provided with first tenon teeth B on both sides of the circumference, which cooperate and connect with the first tenon grooves A.

[0024] Specifically, the inner core 101 has first mortise and tenon grooves A on both sides of its circumference, which cooperate with the first mortise and tenon teeth B on the radial permanent magnet 201 in the circumference direction. The outer core 102 also has first mortise and tenon grooves A on both sides of its circumference, which cooperate with the first mortise and tenon teeth B on the radial permanent magnet 201 in the circumference direction, thus forming a ring-shaped connection structure. The first mortise and tenon grooves A of the inner core 101 and the first mortise and tenon grooves A of the outer core 102 may have certain structural differences, as long as they match the corresponding first mortise and tenon teeth B on the radial permanent magnet 201. Preferably, the structures of the first mortise and tenon grooves A and the corresponding structures of the first mortise and tenon teeth B are completely identical. In addition, the number of first mortise and tenon grooves A that cooperate between the inner core 101 and the radial permanent magnet 201 on one side can be multiple, and the number of corresponding first mortise and tenon teeth B can be multiple. Similarly, the number of first mortise and tenon grooves A that cooperate between the outer core 102 and the radial permanent magnet 201 on one side can be multiple, and the number of corresponding first mortise and tenon teeth B can be multiple. The mortise and tenon structure is interlocked and fixed, and the internal iron core 101, external iron core 102 and radial permanent magnet 201 further restrict the position of the tangential permanent magnet assembly, thereby improving the assembly accuracy of the permanent magnet rotor, effectively suppressing the displacement and vibration of the permanent magnet under high-speed rotation, and ensuring that the air gap magnetic field distribution remains stable for a long time. At the same time, the mortise and tenon connection avoids the risk of thermal failure and stress concentration caused by adhesives or fasteners, and significantly improves the reliability and lifespan of the motor under high temperature and high speed conditions.

[0025] Of course, in some other embodiments, the inner core and the outer core are provided with first tenon teeth on both sides of the circumference, and the radial permanent magnet is provided with first tenon grooves on both sides of the circumference that cooperate with and connect with the first tenon teeth. This structure can also achieve the above-mentioned effect.

[0026] In one embodiment, combined with Figure 3 and Figure 4 , Figure 4 yes Figure 3 A schematic diagram showing the structural dimensions and angle markings of the rotor core assembly. The inner radius of the inner core 101 is the first radius R1, the outer radius of the inner core 101 is the second radius R2, the inner radius of the outer core 102 is the third radius R3, and the outer radius of the outer core 102 is the fourth radius R4.

[0027] The ratio of the first radius R1 to the second radius R2 is equal to the ratio of the third radius R3 to the fourth radius R4, i.e., R1 / R2 = R3 / R4. This ratio makes the magnetic circuit distribution more uniform. The ratio of the first radius R1 to the second radius R2 is between 0.5 and 1. For example, R1 / R2 can be 0.5, 0.6, 0.7, 0.8, 0.9, or 1, etc. Preferably, R1 / R2 is 0.89. The difference between the ratio of the first radius R1 to the second radius R2 and the ratio of the first radius R1 to the third radius R3 does not exceed 0.1, i.e., R1 / R2... R1 / R3≤0.1, for example, can be 0.1, 0.08, 0.06, 0.04, etc., preferably R1 / R3 can be 0.89. The above constraint conditions help to improve the smoothness of the magnetic flux density gradient and the mechanical strength of the permanent magnet rotor.

[0028] In one embodiment, the central angle θ2 corresponding to the rotor core assembly 100 is between 5° and 15°. For example, the central angle θ2 is 5°, 8°, 10°, 12° or 15°, etc., preferably 8°. This angle ensures that the structure has a certain mechanical strength while ensuring that the permanent magnet rotor 10 has a good geomagnetic field distribution.

[0029] In one embodiment, see Figure 2 and Figure 3 The outer core 102 has a second tenon tooth C at its outer edge in the radial direction. The second tenon tooth C is used to cooperate with the corresponding second tenon groove provided on the inner side of the housing.

[0030] Specifically, the second tenon teeth C of the outer iron core 102 are connected to the corresponding second tenon grooves provided on the inner side of the outer casing, thereby realizing the boltless rigid positioning of the permanent magnet rotor 10 and the casing, greatly reducing the eccentric vibration caused by assembly deviation. Multiple second tenon teeth C are evenly distributed along the circumference to ensure uniform transmission of circumferential torque.

[0031] In one embodiment, combined with Figure 3 and Figure 4 The outer radial surface of the second tenon C is an arc surface, and the angle θ1 between the side of the second tenon C and the radial direction is between 30° and 60°. For example, the angle θ1 can be 30°, 40°, 50°, or 60°, preferably 45°, which ensures optimal assembly guidance and structural strength. The radius of the arc surface is the fifth radius R5, and the ratio of the fourth radius R4 to the fifth radius R5 is between 0.95 and 1, for example, R4 / R5 can be 0.95, 0.97, or 0.99, preferably 0.99.

[0032] In one embodiment, combined with Figure 3 and Figure 4The radius of the corner between the inner side of the inner core 101 and the outer side of the outer core 102 is the radius of the sixth radius Ra, and the radius of the corner between the outer side of the inner core 101 and the inner side of the outer core 102 is the radius of the seventh radius Rm. The ratio of the seventh radius Rm to the sixth radius Ra is between 0.5 and 0.7. For example, Rm / Ra can be 0.5, 0.55, 0.6, 0.65 or 0.7, etc. Preferably, Rm / Ra is 0.6. This ratio design effectively alleviates stress concentration and improves the overall leakage flux.

[0033] In one embodiment, combined with Figure 3 and Figure 4 The bottom width of the second mortise C is the first dimension M1, the depth of the first mortise groove A is the second dimension M2, and the width of the first mortise groove A is the third dimension M3. The ratio of the second dimension M2 to the third dimension M3 is between 0.3 and 0.5. For example, M2 / M3 can be 0.3, 0.35, 0.4, 0.45, or 0.5, preferably 0.42. This ratio ensures the reliability of the mortise and tenon connection while reducing the impact on the magnetic field distribution. The ratio of the third dimension M3 to the difference between the second radius R2 and the first radius R1 is between 0.05 and 0.15. For example, M3 / (R2-R1) can be 0.05, 0.08, 0.1, 0.12, or 0.15, preferably 0.11. This ratio further reduces magnetic circuit distortion while ensuring the connection effect. The ratio of the second dimension M2 to the first dimension M1 is between 0.2 and 0.3. For example, M2 / M1 can be 0.2, 0.25, or 0.3, etc., preferably 0.25. The corners on both sides of the second tenon C are rounded corners with a radius of the eighth radius Rs. The ratio of the eighth radius Rs to the sixth radius Ra is between 0.3 and 0.5. For example, Rs / Ra can be 0.3, 0.4, or 0.5, etc., preferably 0.4.

[0034] In one embodiment, combined with Figure 3 and Figure 4 The corner of the first tenon groove A is a rounded corner with a radius of the ninth radius Rc. The ratio of the ninth radius Rc to the sixth radius Ra is between 0.1 and 0.3. For example, Rc / Ra can be 0.1, 0.2 or 0.3, etc., preferably 0.2. This small rounded corner avoids the sudden change in local magnetic flux caused by sharp corners, and also takes into account the feasibility of processing and assembly tolerance, so that the magnetic flux path is smoother.

[0035] In one embodiment, combined with Figure 2 and Figure 5 , Figure 5 yes Figure 2 A schematic diagram showing the structural dimensions of the radial permanent magnet 201. The radial dimension of the radial permanent magnet 201 is the first height H. PMAThe radial permanent magnet 201 has a first width W in the direction perpendicular to the radial direction. PMA The difference between the outer radius of the outer core 102 and the inner radius of the inner core 101 is equal to the first height H. PMA This configuration ensures that the radial permanent magnet 201 is fully embedded within the gap of the rotor core assembly 100, preventing magnetic circuit leakage.

[0036] In one embodiment, combined with Figure 2 and Figure 5 The distance between the first tenon tooth B near the outer side of the radial permanent magnet 201 and the outer side of the radial permanent magnet 201 is the first distance M4. The distance between the first tenon tooth B near the inner side of the radial permanent magnet 201 and the inner side of the radial permanent magnet 201 is the first distance M4. The first distance M4 is related to the first height H. PMA The ratio is between 0.15 and 0.25. For example, M4 / H PMA The value can be 0.15, 0.2 or 0.25, etc., preferably 0.19, which is more central and can ensure the mechanical constraint of the mortise and tenon structure on the tangential permanent magnet 202 while minimizing the interference to the main magnetic circuit.

[0037] In one embodiment, see Figure 5 The corners on both sides of the radial permanent magnet 201 are rounded. The radius of this rounded corner is the sixth radius Ra.

[0038] In one embodiment, see Figure 2 Each radial permanent magnet 201 is a rounded rectangle, and each tangential permanent magnet 202 is a rounded tile shape. The rounded rectangle design prevents stress concentration in the radial permanent magnets 201 during assembly and also improves the smooth transition of magnetic flux distribution.

[0039] In one embodiment, see Figure 2 The magnetization direction of the radial permanent magnet 201 is circumferential, and the magnetization directions of any two adjacent radial permanent magnets 201 are opposite. The tangential permanent magnet group includes three tangential permanent magnets 202 with different magnetization directions. The middle tangential permanent magnet 202 is magnetized radially, and the magnetization directions of the other two tangential permanent magnets 202 are circumferential.

[0040] Specifically, the dimensions of the tangential permanent magnets 202 may not be exactly the same. The magnetization direction of the tangential permanent magnet 202 located in the middle position is radial, and in any two adjacent tangential permanent magnet groups, the magnetization directions of the tangential permanent magnet 202 located in the middle position are opposite. The magnetization direction of the radial permanent magnets 201 is circumferential, and the magnetization directions of any two adjacent radial permanent magnets 201 are opposite. At the same time, the tangential permanent magnets 202 on both sides of the tangential permanent magnet 202 located in the middle position play a role in optimizing the magnetic field distribution between the radial permanent magnets 201 and the tangential permanent magnet 202 located in the middle position, so as to avoid abrupt changes in the magnetic circuit caused by the size difference between the radial permanent magnets 201 and the tangential permanent magnets 202.

[0041] Of course, in some other embodiments, the tangential permanent magnets 202 on both sides of the tangential permanent magnet 202 in the middle position can adopt a magnetization design with a gradient change in direction, and the magnetization direction can be designed to gradually transition from radial to circumferential.

[0042] In one embodiment, combined with Figure 2 and Figure 6 , Figure 6 yes Figure 2 A schematic diagram showing the structural dimensions and angle markings corresponding to the tangential permanent magnet assembly. The radial dimension of the tangential permanent magnet 202 is the first thickness H. PMB The difference between the inner radius of the outer core 102 and the outer radius of the inner core 101 is equal to the first thickness H. PMB This design ensures that the outer core 102 and the inner core 101 can tightly limit the tangential permanent magnet 202, thereby suppressing its micro-vibration and displacement during operation and improving the overall structural stability and electromagnetic performance consistency.

[0043] In one embodiment, combined with Figure 2 and Figure 6 The central angle corresponding to the tangential permanent magnet group is the first included angle θ3, and the central angle corresponding to each tangential permanent magnet 202 is the second included angle θ4. The ratio of the second included angle θ4 to the first included angle θ3 is between 0.2 and 0.4. For example, θ4 / θ3 can be 0.2, 0.3, 0.35, or 0.4, etc., and this ratio is preferably 1 / 3. The first included angle θ3 is between 3° and 8°. For example, θ3 can be 3°, 4.5°, 6°, or 8°, etc., and it is preferred that θ3 is 5°.

[0044] In one embodiment, combined with Figure 2 and Figure 6 The corners of the tangential permanent magnet 202 are rounded. The radius of the rounded corner is the seventh radius Rm, which is equal to the outer radius of the inner iron core 101 and the inner radius of the outer iron core 102, so as to form a symmetrical structure.

[0045] In one embodiment, the rotor core assembly 100 includes a plurality of laminations arranged radially, the laminations being made of silicon steel sheets. This design can effectively reduce energy loss in the core.

[0046] In one embodiment, the permanent magnet assembly 200 is made of neodymium iron boron (NdFeB). NdFeB has extremely high energy product and coercivity.

[0047] Reference Figure 7 , Figure 7 This is a schematic diagram of the unloaded magnetic field lines of a local Halbach array permanent magnet rotor of this application. It can be seen that the hybrid magnetic pole Halbach array permanent magnet rotor proposed in this application can significantly reduce the leakage magnetic flux between permanent magnet poles.

[0048] Reference Figure 8 , Figure 8 This diagram compares the no-load back EMF of a conventional radial permanent magnet rotor with that of the Halbach array permanent magnet rotor described in this application. In the diagram, A represents the conventional radial permanent magnet rotor, and B represents the high-concentration Halbach array permanent magnet rotor described in this application. The Halbach array permanent magnet rotor structure described in this application can improve the no-load back EMF of the motor.

[0049] Reference Figure 9 , Figure 9 This is a torque comparison diagram between a conventional radial permanent magnet rotor and the Halbach array permanent magnet rotor of this invention. In the diagram, A represents the conventional radial permanent magnet rotor, and B represents the Halbach array permanent magnet motor of this application. Compared with the conventional radial permanent magnet rotor structure, the Halbach array permanent magnet rotor of this application has an approximately 10% torque increase.

[0050] This application also provides an electric motor comprising any of the aforementioned Halbach array permanent magnet rotors. By configuring the Halbach array permanent magnet rotor, this motor can achieve the same technical effects as described above, which will not be elaborated further in this application.

[0051] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A Halbach array permanent magnet rotor, characterized in that, The permanent magnet rotor includes: Multiple rotor units arranged in a circumferential array, each rotor unit comprising a rotor core assembly and a permanent magnet assembly that are mutually connected; The permanent magnet assembly includes a radial permanent magnet and a tangential permanent magnet group. The tangential permanent magnet group includes multiple tangential permanent magnets arranged circumferentially. The rotor core assembly and the multiple tangential permanent magnets are located on one side of the radial permanent magnet in the circumferential direction. The magnetization directions of the multiple tangential permanent magnets are all different. Each radial permanent magnet is a rounded rectangle, and each tangential permanent magnet is a rounded tile shape. The magnetization direction of the radial permanent magnet is the circumferential direction, and the magnetization directions of any two adjacent radial permanent magnets are opposite. The tangential permanent magnet group includes three tangential permanent magnets with different magnetization directions. The middle tangential permanent magnet has a radial magnetization direction, and the other two tangential permanent magnets have circumferential magnetization directions. The rotor core assembly includes an inner core located on the inner side of the tangential permanent magnet in the radial direction and an outer core located on the outer side; the inner core and the outer core are provided with a first tenon groove on both sides in the circumferential direction, and the radial permanent magnet is provided with a first tenon tooth on both sides in the circumferential direction that cooperates with and connects to the first tenon groove.

2. The permanent magnet rotor according to claim 1, characterized in that, The inner radius of the inner core is a first radius, the outer radius of the inner core is a second radius, the inner radius of the outer core is a third radius, and the outer radius of the outer core is a fourth radius. The ratio of the first radius to the second radius is equal to the ratio of the third radius to the fourth radius. The ratio of the first radius to the second radius is between 0.5 and 1. The difference between the ratio of the first radius to the second radius and the ratio of the first radius to the third radius does not exceed 0.

1. The central angle corresponding to the rotor core assembly is between 5° and 15°.

3. The permanent magnet rotor according to claim 2, characterized in that, The outer core is provided with a second tenon tooth at the outer edge in the radial direction. The second tenon tooth is used to cooperate with and connect with the corresponding second tenon groove provided on the inner side of the housing. The outer surface of the second tenon tooth in the radial direction is an arc surface, the second included angle between the side of the second tenon tooth and the radial direction is between 30° and 60°, the radius of the arc surface is the fifth radius, and the ratio of the fourth radius to the fifth radius is between 0.95 and 1.

4. The permanent magnet rotor according to claim 3, characterized in that, The corners on the inner side of the inner core and the outer side of the outer core are rounded with a radius of the sixth radius, and the corners on the outer side of the inner core and the inner side of the outer core are rounded with a radius of the seventh radius, with the ratio of the seventh radius to the sixth radius between 0.5 and 0.7; the bottom width of the second mortise tooth is the first dimension, the depth of the first mortise groove is the second dimension, the width of the first mortise groove is the third dimension, with the ratio of the second dimension to the third dimension between 0.3 and 0.5, the ratio of the third dimension to the difference between the second radius and the first radius between 0.05 and 0.15, the ratio of the second dimension to the first dimension between 0.2 and 0.3, the corners on both sides of the second mortise tooth are rounded with a radius of the eighth radius, with the ratio of the eighth radius to the sixth radius between 0.3 and 0.5, and the corner of the first mortise groove is a rounded with a radius of the ninth radius, with the ratio of the ninth radius to the sixth radius between 0.1 and 0.

3.

5. The permanent magnet rotor according to claim 1, characterized in that, The radial dimension of the radial permanent magnet is a first height, and the difference between the outer radius of the outer core and the inner radius of the inner core is equal to the first height; the distance between the first tenon tooth near the outer side of the radial permanent magnet and the outer side of the radial permanent magnet is a first distance, the distance between the first tenon tooth near the inner side of the radial permanent magnet and the inner side of the radial permanent magnet is a first distance, and the ratio of the first distance to the first height is between 0.15 and 0.

25.

6. The permanent magnet rotor according to claim 1, characterized in that, The corners on both sides of the radial permanent magnet are rounded.

7. The permanent magnet rotor according to claim 1, characterized in that, The radial dimension of the tangential permanent magnet is a first thickness, and the difference between the inner radius of the outer core and the outer radius of the inner core is equal to the first thickness.

8. The permanent magnet rotor according to claim 1, characterized in that, The central angle corresponding to the tangential permanent magnet group is the first included angle, and the central angle corresponding to each tangential permanent magnet is the second included angle. The ratio of the second included angle to the first included angle is between 0.2 and 0.4, and the first included angle is between 3° and 8°.

9. The permanent magnet rotor according to claim 1, characterized in that, The corners of the tangential permanent magnet are rounded.

10. The permanent magnet rotor according to claim 1, characterized in that, The rotor core assembly includes multiple laminations arranged radially, the laminations being made of silicon steel sheets.

11. The permanent magnet rotor according to claim 1, characterized in that, The permanent magnet assembly is made of neodymium iron boron.

12. An electric motor, characterized in that, The motor comprises a Halbach array permanent magnet rotor as described in any one of claims 1 to 11.

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