Axial field motor rotor structure

Abstract

The application relates to an axial magnetic field motor, in particular to a rotor structure of an axial magnetic field motor, which comprises a rotor core, a plurality of permanent magnets, the plurality of permanent magnets are arranged at intervals in a circle, the inner surface of the permanent magnets in the axial direction is arranged on the rotor core, and the outer surface of the permanent magnets in the axial direction is provided with permanent magnet recesses; a pressing plate, the pressing plate comprises an inner limiting part, an outer limiting part and a plurality of claw parts, the claw parts are connected between the inner limiting part and the outer limiting part, each claw part is respectively inlaid in a permanent magnet recess, the inner limiting part and the outer limiting part are fixed on the rotor core, and the permanent magnets are radially limited between the inner limiting part and the outer limiting part, the permanent magnets are limited and fixed through the pressing plate, and the reliability and stability of motor operation are ensured.

Description

Technical Field

[0001] This invention relates to the field of axial magnetic field motors, and more particularly to a rotor structure for an axial magnetic field motor. Background Technology

[0002] Axial field motors, also known as disc motors, have advantages such as small axial dimensions, high torque density, high power density, and high efficiency, and are widely used in electric vehicles, general industrial applications, and household appliances. The rotor and stator of an axial field motor are parallel, forming an air gap between them.

[0003] A rotor typically consists of a fixed disk and permanent magnets mounted on the fixed disk. The accuracy of the permanent magnets' mounting position directly affects the performance of an axial magnetic field motor. If the permanent magnets lack protection, they are prone to loosening relative to the fixed disk, and they can also generate eddy currents that heat up, affecting motor performance. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an axial magnetic field motor rotor structure that uses a pressure plate to limit and fix a permanent magnet. Furthermore, a pole shoe core can be added between the pressure plate and the permanent magnet. The pole shoe core satisfies the requirements for fixing the permanent magnet, as well as the requirements for magnetic conduction, and can also reduce its eddy current loss.

[0005] This invention provides an axial magnetic field motor rotor structure, comprising:

[0006] Rotor core;

[0007] A plurality of permanent magnets are arranged at circumferential intervals. The inner surface of the permanent magnets is disposed on the rotor core, and the outer surface of the permanent magnets is provided with a permanent magnet recess.

[0008] The pressure plate includes an inner limiting part, an outer limiting part, and a plurality of claw parts. The claw parts are connected between the inner limiting part and the outer limiting part. Each claw part corresponds to a permanent magnet and is embedded in the recess of the permanent magnet. The inner limiting part and the outer limiting part are fixed to the rotor core, and the permanent magnet is radially limited between the inner limiting part and the outer limiting part.

[0009] In a preferred embodiment, the recessed portion of the permanent magnet is located on the center line of the permanent magnet and extends through the inner radial side and the outer radial side of the permanent magnet.

[0010] As a preferred embodiment, it also includes:

[0011] Several pole shoe cores are provided, with one pole shoe core disposed between each permanent magnet and the pressure plate.

[0012] In a preferred embodiment, the pole shoe core includes a surface body and two side bodies. The two side bodies are connected to the two sides of the surface body in the circumferential direction. The surface body is adapted to be disposed on the upper surface of the permanent magnet in the axial direction, and a surface body recess adapted to the recess of the permanent magnet is formed on the surface body. The claw is embedded in the surface body recess, and the permanent magnet is disposed between the two side bodies.

[0013] In a preferred embodiment, the pole shoe core has a plurality of slits that penetrate the surface layer.

[0014] In a preferred embodiment, the rotor core includes a first core, the first core including a mounting surface, and the permanent magnet and the pressure plate are fixed to the mounting surface.

[0015] In a preferred embodiment, the rotor core includes a first core, which includes a mounting surface and an inner boss. The inner boss protrudes upward and is connected to the radially inner side of the mounting surface. The inner limiting part is fixed to the inner boss, and the outer limiting part is fixed to the mounting surface. The radially inner side of the permanent magnet abuts against the inner boss and the inner limiting part, respectively.

[0016] In a preferred embodiment, the rotor core further includes a second core, and a plurality of mounting slots are provided on the mounting surface, with the second core embedded in the mounting slots.

[0017] In a preferred embodiment, screws are also included, and the pressure plate and the rotor core are fixed together by screws;

[0018] The inner limiting part has several inner holes, and the screw passes through the inner holes and is screwed to the rotor core;

[0019] The outer limiting part has several outer holes, and the screw passes through the outer holes and is screwed to the rotor core.

[0020] In a preferred embodiment, the two circumferential sides of the permanent magnet are respectively provided with a right-angled structure or a stepped structure;

[0021] And / or, the two radial sides of the permanent magnet are respectively provided with a right-angled structure or a stepped structure.

[0022] Compared with existing technologies, this technical solution has the following advantages:

[0023] The permanent magnet has a recess on its axial outer surface to fit the claw portion. The pressure plate is fixed to the rotor core so that the claw portion applies force to the permanent magnet, thereby fixing and limiting the permanent magnet on the rotor core.

[0024] The way the pressure plate fixes the permanent magnet releases the interpole space between adjacent permanent magnets, which can increase the inner and outer pole arc coefficient of the permanent magnet, even to 1, thereby enhancing the torque and power output capability of the motor.

[0025] The pole shoe core can also be added between the permanent magnet and the pressure plate. The pole shoe core has a gap, which can reduce its eddy current loss. At the same time, its material can meet the magnetic conductivity requirements, improve motor efficiency, and enhance the safety and reliability of the permanent magnet.

[0026] Using the aforementioned pole shoe core, a rotor structure with a saliency ratio of less than 1 can be designed, while without the aforementioned pole shoe core, a rotor structure with a saliency ratio of 1 can be designed.

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the first embodiment of the axial magnetic field motor rotor structure described in this invention;

[0029] Figure 2 This is an exploded view of the first embodiment of the axial magnetic field motor rotor structure described in this invention;

[0030] Figure 3 This is a cross-sectional view of the first embodiment of the axial magnetic field motor rotor structure described in this invention;

[0031] Figure 4 This is a perspective view of the first embodiment of the permanent magnet described in this invention;

[0032] Figure 5 This is a front view of the first embodiment of the permanent magnet described in this invention;

[0033] Figure 6 This is a front view of the first embodiment of the permanent magnet described in this invention;

[0034] Figure 7 This is a front view of the second embodiment of the permanent magnet described in this invention;

[0035] Figure 8 This is a schematic diagram of the structure of the pressure plate described in this invention;

[0036] Figure 9 This is a schematic diagram of the structure of the first iron core in the first embodiment of the axial magnetic field motor rotor structure of the present invention;

[0037] Figure 10 This is a schematic diagram of the second embodiment of the axial magnetic field motor rotor structure described in this invention;

[0038] Figure 11 This is an exploded view of the second embodiment of the axial magnetic field motor rotor structure described in this invention;

[0039] Figure 12 This is a cross-sectional view of a second embodiment of the axial magnetic field motor rotor structure described in this invention;

[0040] Figure 13 This is a schematic diagram of the structure of the pole shoe core described in this invention;

[0041] Figure 14 This is a schematic diagram of the assembly of the pole shoe core and permanent magnet described in this invention;

[0042] Figure 15 This is a schematic diagram of the assembly of the pole shoe core, permanent magnet and pressure plate in the second embodiment of the axial magnetic field motor rotor structure of the present invention;

[0043] Figure 16 This is a schematic diagram of the first iron core in the second embodiment of the axial magnetic field motor rotor structure of the present invention.

[0044] In the diagram: 100 Rotor core, 110 First core, 111 Mounting surface, 1111 Mounting groove, 1121 Internal threaded hole, 1131 External threaded hole, 112 Inner boss, 114 Limiting part, 120 Second core, 200 Permanent magnet, 201 Permanent magnet recess, 210 First surface, 220 Second surface, 230 Third surface, 240 Fourth surface, 250 Fifth surface, 300 Pole shoe core, 310 Surface body, 311 Surface body recess, 350 Side body, 351 Notch, 500 Screw, 600 Pressure plate, 620 Inner limiting part, 621 Inner hole, 622 Semicircular part, 630 Outer limiting part, 631 Outer hole, 650 Claw part, 3000 Gap. Detailed Implementation

[0045] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0046] First Embodiment

[0047] like Figures 1 to 3 As shown, the rotor structure of the axial magnetic field motor includes:

[0048] Rotor core 100;

[0049] A plurality of permanent magnets 200 are arranged at circumferential intervals. The inner surface of the permanent magnet 200 is disposed on the rotor core 100, and a permanent magnet recess 201 is formed on the outer surface of the permanent magnet 200.

[0050] The pressure plate 600 includes an inner limiting part 620, an outer limiting part 630, and a plurality of claw parts 650. The claw parts 650 are connected between the inner limiting part 620 and the outer limiting part 630. Each claw part 650 is respectively provided for one permanent magnet 200 and is embedded in the recess 201 of the permanent magnet. The inner limiting part 620 and the outer limiting part 630 are fixed on the rotor core 100, and the permanent magnet 200 is radially limited between the inner limiting part 620 and the outer limiting part 630.

[0051] The permanent magnet 200 has a recess 201 on its axial outer surface to fit with the claw 650. The pressure plate 600 is fixed to the rotor core 100. The claw 650 applies force to the permanent magnet 200, thus securing the permanent magnet 200 to the rotor core 100. The permanent magnet 200 is axially confined between the claw 650 and the rotor core 100, and the claw 650 and the recess 201 cooperate to provide circumferential constraint on the permanent magnet 200. Furthermore, the permanent magnet 200 is radially confined between the inner limiting part 620 and the outer limiting part 630, improving the accuracy of the permanent magnet 200 installation. This meets the high-speed rotation requirements of axial flux motors for electric vehicles, ensuring reliable and stable motor operation. Furthermore, the way the pressure plate 600 fixes the permanent magnet 200 releases the interpole space between adjacent permanent magnets 200, which can increase the inner and outer pole arc coefficient of the permanent magnet, even to 1, thereby enhancing the torque and power output capability of the motor.

[0052] like Figure 2 and Figure 9 As shown, the rotor core 100 includes a first core 110, the first core 110 includes a mounting surface 111, and the permanent magnet 200 and the pressure plate 600 are fixed on the mounting surface 111.

[0053] The first iron core 110 can be made of high-strength structural materials to improve its support capacity. The first iron core 110 has a disc-shaped structure, the mounting surface 111 is a horizontal plane, the permanent magnet 200 and the pressure plate 600 are both disposed on the mounting surface 111, and the first iron core 110 eliminates the boss structure, which can significantly reduce the loss on the rotor iron core and improve the motor efficiency.

[0054] In detail, existing rotor cores use inner and / or outer bosses on the first core 110 to radially constrain the permanent magnet 200 through the cooperation of the inner and outer bosses. The inner boss also provides circumferential constraint on the permanent magnet 200. The height of the boss directly determines the constraint capability on the permanent magnet; therefore, the boss height cannot be too small, while increasing the boss height will cause a sharp increase in losses. The first core 110 of this application eliminates the boss structure and uses the pressure plate 600 to limit and constrain the permanent magnet 200, thereby reducing rotor core losses.

[0055] Continue to refer to Figure 3 and Figure 9 The rotor core 100 also includes a second core 120. The mounting surface 111 has a plurality of mounting slots 1111, and the second core 120 is embedded in the mounting slots 1111.

[0056] Specifically, the mounting groove 1111 is annular, and several mounting grooves 1111 are arranged radially at intervals. Each mounting groove 1111 contains a second iron core 120, meaning the second iron core 120 is also annular. The second iron core 120 can be made of a mixture of iron-silicon powder and high-viscosity adhesive, serving a magnetic conductive function, improving the bonding ability between the second iron core 120 and the first iron core 110, and facilitating the molding of the second iron core 120.

[0057] like Figure 1 , Figure 4 and Figure 5 As shown, the permanent magnet 200 is trapezoidal, and its width gradually increases radially from the inside to the outside. The inner surface of the permanent magnet 200 is attached to the mounting surface 111, and a permanent magnet recess 201 is formed on the outer surface of the permanent magnet 200.

[0058] Specifically, the permanent magnet recess 201 penetrates the radial inner side and the radial outer side of the permanent magnet 200, and the permanent magnet recess 201 is located on the center line of the permanent magnet 200. When the claw 650 is embedded in the permanent magnet recess 201 and applies force to the permanent magnet 200, the permanent magnet 200 can be firmly fixed on the rotor core 100.

[0059] refer to Figure 4 and Figure 8 The permanent magnet recess 201 is adapted to the shape of the claw 650, and the depth of the permanent magnet recess 201 and the thickness of the claw 650 are designed in accordance with the requirements of electromagnetic performance and mechanical performance.

[0060] Continue to refer to Figure 4 and Figure 8 The inner radial surface of the permanent magnet 200 is adapted to the inner limiting portion 620, and the outer radial surface of the permanent magnet 200 is adapted to the outer limiting portion 630. For example, if the inner radial surface of the permanent magnet 200 is concave, then the surface of the inner limiting portion 620 that abuts against the permanent magnet 200 is convex; if the outer radial surface of the permanent magnet 200 is convex, then the surface of the outer limiting portion 630 that abuts against the permanent magnet 200 is concave.

[0061] Furthermore, the two circumferential sides of the permanent magnet 200 may be provided with a right-angled structure or a stepped structure respectively; and / or, the two radial sides of the permanent magnet 200 may be provided with a right-angled structure or a stepped structure respectively.

[0062] Taking the two circumferential sides of the permanent magnet 200 as examples, the chamfered right-angle structure and the stepped structure are introduced:

[0063] refer to Figure 6 The permanent magnet 200 has two circumferentially connected side surfaces, each including a first surface 210 and a second surface 220. The first surface 210 extends between the outer axial surface of the permanent magnet 200 and the second surface 220, and the second surface 220 extends between the first surface 210 and the inner axial surface of the permanent magnet 200. The axial dimension of the first surface 210 is denoted as a, and the axial dimension of the second surface 220 is denoted as b, where a > b. The second surface 220 is perpendicular to both the outer axial surface and the inner axial surface of the permanent magnet 200, while the first surface 210 is inclined relative to the second surface 220, with an inclination angle denoted as θ, so that the two circumferentially connected side surfaces of the permanent magnet 200 form a right-angled structure.

[0064] refer to Figure 7 The permanent magnet 200 has three circumferential sides, each comprising a third surface 230, a fourth surface 240, and a fifth surface 250 connected sequentially. The third surface 230 extends between the outer axial surface of the permanent magnet 200 and the fourth surface 240, and the fifth surface 250 extends between the fourth surface 240 and the inner axial surface of the permanent magnet 200. The third surface 230 and the fifth surface 250 are parallel and perpendicular to the outer and inner axial surfaces of the permanent magnet 200, respectively. The fourth surface 240 is perpendicular to both the third surface 230 and the fifth surface 250. The axial dimension of the third surface 230 is denoted as c, the axial dimension of the fifth surface 250 is denoted as d, and the width of the fourth surface 240 is denoted as e. C, d, and e are determined according to electromagnetic design requirements. The two circumferential sides of the permanent magnet 200 form a stepped structure.

[0065] like Figure 8As shown, the pressure plate 600 is an integral structure, made of high-strength, low-conductivity, non-magnetic or low-magnetic-permeability material. The inner limiting part 620 and the outer limiting part 630 are annular, and a plurality of claw parts 650 are arranged at circumferential intervals, and the number of claw parts 650 is the same as that of the permanent magnet 200. Figure 1 .

[0066] like Figure 1 and Figure 2 As shown, the axial magnetic field motor rotor structure also includes screws 500. The pressure plate 600 and the rotor core 100 are fixed together by screws 500. The fixing by screws 500 effectively improves the fastening effect and is particularly suitable for medium and high speed motors.

[0067] refer to Figure 8 The inner limiting part 620 has several inner holes 621, and the screw 500 passes through the inner holes 621 and is screwed to the first iron core 110 of the rotor iron core 100; the outer limiting part 630 has several outer holes 631, and the screw 500 passes through the outer holes 631 and is screwed to the first iron core 110 of the rotor iron core 100, so as to fix the pressure plate 600 and the rotor iron core 100.

[0068] refer to Figure 9 The first iron core 110 has an internally threaded hole 1121 corresponding to the inner hole 621. The screw 500 passes through the inner hole 621 and is screwed into the internally threaded hole 1121 to fix the pressure plate 600 and the rotor core 100. Similarly, the first iron core 110 also has an externally threaded hole 1131 corresponding to the outer hole 631.

[0069] Continue to refer to Figure 1 and Figure 8 The inner hole 621 and the outer hole 631 are opposite each other and located in the middle of two adjacent claw portions 650. The screw size passing through the inner hole 621 is larger than the screw size passing through the outer hole 631. Since the two adjacent permanent magnets 200 are not blocked by the pressure plate 600, the inner limiting portion 620 can protrude towards the outer limiting portion 630 to form a semi-circular portion 622 for opening the inner hole 621.

[0070] By designing L q and L d Different salient pole ratios can be obtained, and the formula for calculating the salient pole ratio is:

[0071] ρ=L q / L d

[0072] ρ is the salient pole ratio, Lq For Q-axis inductance, L d For the D-axis inductance, L q and L d The magnitude of L is related to the magnetic reluctance along the Q-axis and D-axis magnetic paths. Within the rotor range, the difference between the Q-axis and D-axis magnetic paths is as follows: the Q-axis magnetic path runs between adjacent permanent magnets 200, while the D-axis magnetic path runs between the permanent magnets 200 and the claw portion 650. The permeability of the permanent magnets 200 is comparable to that of air, the claw portion 650 is made of a non-magnetic material, and the interpole space between the permanent magnets 200 is air. q =L d Therefore, the salient pole ratio ρ = L q / L d =1, meaning that a rotor structure with a salient pole ratio of 1 is designed.

[0073] The assembly method of the rotor structure of the axial magnetic field motor is as follows:

[0074] A plurality of permanent magnets 200 are placed on the rotor core 100, and the plurality of permanent magnets 200 are arranged at circumferential intervals.

[0075] The permanent magnet 200 is fixed to the rotor core 100 by means of the inner limiting part 620, the outer limiting part 630, and the claw part 650 of the pressure plate 600. The permanent magnet 200 is axially limited between the claw part 650 and the rotor core 100, and the claw part 650 cooperates with the permanent magnet recess 201 to provide circumferential constraint on the permanent magnet 200. Furthermore, the permanent magnet 200 is radially limited between the inner limiting part 620 and the outer limiting part 630.

[0076] As described above, the permanent magnet 200 has a permanent magnet recess 201 on its axial outer surface to fit with the claw 650. The pressure plate 600 is fixed to the rotor core 100, so that the claw 650 applies force to the permanent magnet 200, making the permanent magnet 200 stable on the rotor core 100. The permanent magnet 200 is axially limited between the claw 650 and the rotor core 100, and the claw 650 and the permanent magnet recess 201 cooperate to provide circumferential constraint on the permanent magnet 200. Furthermore, the permanent magnet 200 is radially limited between the inner limiting part 620 and the outer limiting part 630, improving the accuracy of the permanent magnet 200 installation. This meets the high-speed rotation requirements of axial flux motors for electric vehicles, ensuring the reliability and stability of motor operation. Furthermore, the way the pressure plate 600 fixes the permanent magnet 200 releases the interpole space between adjacent permanent magnets 200, which can increase the inner and outer pole arc coefficient of the permanent magnet, even to 1, thereby enhancing the torque and power output capability of the motor.

[0077] Second Embodiment

[0078] like Figures 10 to 16 As shown, the axial magnetic field motor rotor structure of the second embodiment differs from that of the first embodiment in that the rotor core 100 has a different structure, and the axial magnetic field motor rotor structure also includes a pole shoe core 300.

[0079] like Figures 10 to 12 As shown, the rotor structure of the axial magnetic field motor also includes a plurality of pole shoe cores 300. Each of the permanent magnets 200 and the pressure plate 600 is respectively provided with one pole shoe core 300, that is, the number of pole shoe cores 300 is the same as the number of permanent magnets 200, and each permanent magnet 200 corresponds to one pole shoe core 300.

[0080] like Figure 13 and Figure 14 As shown, the pole shoe core 300 includes a surface body 310 and two side bodies 350. The two side bodies 350 are connected to the two sides of the surface body 310 in the circumferential direction. The surface body 310 is adapted to be disposed on the upper surface of the permanent magnet 200 in the axial direction, and a surface body recess 311 adapted to the permanent magnet recess 201 is formed on the surface body 200. The claw 650 is embedded in the surface body recess 311, and the permanent magnet 200 is disposed between the two side bodies 350.

[0081] refer to Figure 12 and Figure 13The surface body recess 311 is concave on the upper surface of the surface body 310, for embedding the claw portion 650 of the pressure plate 600, and the shapes of the two are compatible. The surface body recess 311 is convex on the lower surface of the surface body 310, for embedding in the permanent magnet recess 201.

[0082] The surface layer 310 is adapted to the shape of the permanent magnet 200, and after the surface layer 310 and the permanent magnet 200 are assembled, their outer circumferences are aligned, that is, the width of the surface layer 310 gradually increases radially from the inside to the outside. The two circumferential sides of the permanent magnet 200 are adapted to the side body 350, and can be provided with a right-angled structure and a stepped structure.

[0083] The pole shoe core 300 has several slits 3000 that penetrate the surface body 310. By providing these slits 3000, the induced eddy currents in the pole shoe core 300 are blocked, reducing their eddy current losses. Furthermore, these slits provide a conductive path for the high-order harmonic magnetic field in the air gap, significantly reducing the high-order harmonic magnetic field passing through the rotor core. This, in turn, greatly reduces eddy current losses and hysteresis losses in the rotor core.

[0084] The gap 3000 may be annular, linear or other shapes. The gap 3000 on the surface body 310 penetrates the surface body 310 and extends to the side body 350, but does not completely penetrate the side body 350.

[0085] Provided that the requirements for rotor mechanical strength and magnetic conductivity are met, a greater number and longer gaps will help reduce eddy current losses in the pole shoes and rotor core. In addition, the width of the gap 3000 should not exceed 20% of the radial dimension of the permanent magnet 200, which can significantly reduce the eddy current losses of the pole shoe core 300 without causing the pole shoe core 300 to become oversaturated.

[0086] like Figure 11 , Figure 12 and Figure 16 As shown, the first iron core 110 includes a mounting surface 111 and an inner boss 112. The inner boss 112 protrudes upward and connects to the radially inner side of the mounting surface 111. The inner limiting part 620 is fixed to the inner boss 112. The radially inner surface of the permanent magnet 200 abuts against the inner boss 112 and the inner limiting part 620, respectively. The radially outer surface of the permanent magnet 200 abuts against the outer limiting part 630, and the outer limiting part 630 is directly fixed to the mounting surface 111. It can be seen that the rotor iron core eliminates the outer boss structure, which can significantly reduce the eddy current loss of the rotor iron core and improve the motor efficiency.

[0087] like Figure 16 As shown, the inner boss 112 is provided with a plurality of circumferentially spaced limiting parts 114, each of the limiting parts 114 being disposed between two adjacent permanent magnets 200, and capable of circumferentially limiting the permanent magnets 200.

[0088] like Figures 11 to 13 , Figure 16 As shown, there is a gap between the side body 350 and the mounting surface 111, and a notch 351 is provided on the inner side of the side body 350 to avoid the limiting part 114. It can be seen that the permanent magnet 200 is circumferentially limited by the combined action of the side body 350, the claw part 650 and the limiting part 114.

[0089] like Figure 16 As shown, the external threaded hole 1131 is formed on the mounting surface 111, and the internal threaded hole 1121 is formed on the limiting portion 114. (Reference) Figure 11 and Figure 12 The outer surface of the inner limiting part 620 is flush with the outer surface of the inner protrusion 112. The semicircular part 622 is disposed on the outer surface of the inner limiting part 620, and the semicircular part 622 and the limiting part 114 correspond one-to-one, with each semicircular part 622 fixed on one limiting part 114. The pole shoe core 300 is made of a material with high magnetic permeability, high strength, and low electrical conductivity to meet the magnetic conductivity requirements.

[0090] By designing L q and L d Different saliency ratios can be obtained. Within the rotor range, the difference between the Q-axis and D-axis in the magnetic path is as follows: the Q-axis magnetic path runs between adjacent permanent magnets 200, while the D-axis magnetic path runs along the permanent magnets 200, the surface body 310, and the claw portion 650. Since the surface body 310 uses a high-permeability material, its permeability is much greater than that of air, while the permeability of the permanent magnets 200 is comparable to that of air. The claw portion 650 uses a non-magnetic or low-permeability material, and the interpole space between the permanent magnets 200 is air, the magnetic reluctance is greater on the Q-axis magnetic path and smaller on the D-axis magnetic path, i.e., L... q <L d Therefore, the salient pole ratio ρ = L q / L d <1, meaning that a rotor structure with a salient pole ratio of less than 1 is designed.

[0091] The assembly method of the rotor structure of the axial magnetic field motor is as follows:

[0092] A plurality of permanent magnets 200 are placed on the rotor core 100, and the plurality of permanent magnets 200 are arranged at circumferential intervals.

[0093] A pole shoe core 300 is placed on the surface of each permanent magnet 200. The surface recess 311 of the pole shoe core 300 is adapted to be disposed within the permanent magnet recess 201 of the permanent magnet 200.

[0094] The pressure plate 600 is fixed to the rotor core 100, and the claw portion 650 of the pressure plate 600 is embedded in the surface body recess 311 to fix the permanent magnet 200 and the pole shoe core 300 as a whole.

[0095] In summary, by adding the pole shoe core 300 between the permanent magnet 200 and the pressure plate 600, and by providing a gap 3000 on the pole shoe core, eddy current losses can be reduced. Simultaneously, the material of the pole shoe core meets magnetic conductivity requirements, improving motor efficiency and enhancing the safety and reliability of the permanent magnet operation. Furthermore, the pole shoe core 300 allows for the design of a rotor structure with a saliency ratio less than 1, which is beneficial for improving the motor's field weakening and speed-enhancing capabilities.

[0096] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The scope of patent application of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A rotor structure for an axial magnetic field motor, characterized in that, include: Rotor core (100); A plurality of permanent magnets (200) are arranged at circumferential intervals. The inner surface of the permanent magnet (200) is disposed on the rotor core (100) along the axial direction. The outer surface of the permanent magnet (200) along the axial direction is provided with a permanent magnet recess (201). A pressure plate (600) includes an inner limiting part (620), an outer limiting part (630), and a plurality of claw parts (650). The claw parts (650) are connected between the inner limiting part (620) and the outer limiting part (630). Each claw part (650) corresponds to a permanent magnet (200) and is embedded in the recess of the permanent magnet (201). The inner limiting part (620) and the outer limiting part (630) are fixed on the rotor core (100), and the permanent magnet (200) is radially limited between the inner limiting part (620) and the outer limiting part (630). The permanent magnet recess (201) is located on the center line of the permanent magnet (200) and extends through the inner radial side and the outer radial side of the permanent magnet (200).

2. The axial magnetic field motor rotor structure as described in claim 1, characterized in that, Also includes: A plurality of pole shoe cores (300), with one pole shoe core (300) disposed between each of the permanent magnets (200) and the pressure plate (600).

3. The axial magnetic field motor rotor structure as described in claim 2, characterized in that, The pole shoe core (300) includes a surface body (310) and two side bodies (350). The two side bodies (350) are connected to the two sides of the surface body (310) in the circumferential direction. The surface body (310) is adapted to be disposed on the upper surface of the permanent magnet (200) in the axial direction. A surface body recess (311) adapted to the permanent magnet recess (201) is formed on the surface body (200). The claw (650) is embedded in the surface body recess (311). The permanent magnet (200) is disposed between the two side bodies (350).

4. The axial magnetic field motor rotor structure as described in claim 3, characterized in that, The pole shoe core (300) has a plurality of slits (3000) that penetrate the surface body (310).

5. The axial magnetic field motor rotor structure as described in claim 1, characterized in that, The rotor core (100) includes a first core (110), the first core (110) includes a mounting surface (111), and the permanent magnet (200) and the pressure plate (600) are fixed on the mounting surface (111).

6. The axial magnetic field motor rotor structure as described in claim 2, characterized in that, The rotor core (100) includes a first core (110), which includes a mounting surface (111) and an inner boss (112). The inner boss (112) protrudes upward and is connected to the radial inner side of the mounting surface (111). The inner limiting part (620) is fixed on the inner boss (112), and the outer limiting part (630) is fixed on the mounting surface (111). The radial inner side of the permanent magnet (200) abuts against the inner boss (112) and the inner limiting part (620) respectively.

7. The axial magnetic field motor rotor structure as described in any one of claims 5 or 6, characterized in that, The rotor core (100) also includes a second core (120), and a plurality of mounting slots (1111) are provided on the mounting surface (111), and the second core (120) is embedded in the mounting slots (1111).

8. The axial magnetic field motor rotor structure as described in claim 1, characterized in that, It also includes screws (500), and the pressure plate (600) and the rotor core (100) are fixed together by screws (500); The inner limiting part (620) has a plurality of inner holes (621), and the screw (500) passes through the inner holes (621) and is screwed to the rotor core (100); The outer limiting part (630) has a plurality of outer holes (631), and the screw (500) passes through the outer holes (631) and is screwed to the rotor core (100).

9. The axial magnetic field motor rotor structure as described in claim 1, characterized in that, The permanent magnet (200) has a right-angled structure or a stepped structure on both sides of its circumference. And / or, the two radial sides of the permanent magnet (200) are respectively provided with a right-angled structure or a stepped structure.

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