Flux-concentrating rotor structure

Abstract

A flux-concentrating rotor structure, comprising an iron core and a plurality of magnetic steel assemblies. The iron core is formed by stacking multiple layers of silicon steel sheets, and is provided with a plurality of magnetic steel accommodation slots arranged in a circumferential direction. The magnetic steel accommodation slots each have a T-shaped radial cross-section. A radial magnetic bridge is provided between any two adjacent ones of the plurality of magnetic steel accommodation slots, such that each layer of the silicon steel sheets is integrally formed. The plurality of magnetic steel assemblies are annularly arranged on the iron core, and are correspondingly disposed inside the plurality of magnetic steel accommodation slots. Each magnetic steel assembly comprises two radial steel magnets and one tangential steel magnet. The two radial steel magnets are circumferentially disposed on two sides of the tangential steel magnet, respectively, and abut against the tangential steel magnet. The two radial steel magnets are radially magnetized and have opposite magnetization directions, while the tangential steel magnet is tangentially magnetized, and has a magnetization direction opposite to that of the tangential steel magnet in an adjacent magnetic steel assembly.

Description

Magnetic rotor structure Technical Field

[0001] This case involves a rotor structure, specifically a magnetic concentrating rotor structure used in permanent magnet synchronous motors. Its magnetic steel components are fixed through an integrated rotor core to facilitate processing and assembly, while also improving the magnetic concentrating capacity and enhancing the motor's output torque. Background Art

[0002] Generally speaking, a permanent-magnet synchronous motor (PMSM) is a synchronous motor whose rotor uses permanent magnets instead of wound electromagnets. The motor structure includes a shaft, a rotor, and a stator. The shaft is connected to the rotor, which has windings and permanent magnets. The rotor can be made up of, for example, a stack of multi-layer silicon steel sheets. The magnetic interaction between the stator and rotor causes the rotor to rotate, driving the shaft.

[0003] In the prior art, the rotor structure of a permanent magnet motor can be divided into a surface-mounted PM rotor and a tangential-set PM rotor based on the arrangement and magnetization direction of the rotor magnets. The magnetization direction of the surface-mounted PM rotor is radial, but because its cross-axis inductance and direct-axis inductance are equal, the weak magnetic capability is poor, and it cannot generate magnetic reluctance torque during motor operation, which is not conducive to improving the power density and overload capacity of the motor. In addition, the surface-mounted PM rotor often requires a stainless steel sleeve or a carbon fiber protective sleeve to protect and fix the magnets. On the other hand, the magnetization direction of the tangential-set PM rotor is tangential, but because its salient poles are relatively small, the magnetic reluctance torque generated during motor operation is small, which is not conducive to improving the power density and overload capacity of the motor. In addition, the magnetic field size provided by the tangential-set PM rotor is related to the width of the magnetization direction. If a larger magnetic field strength is required, a larger rotor must be used in the product design, thereby increasing the space occupied. Furthermore, the tangential magnetic steel rotor has problems such as large rotor leakage and low torque / power density.

[0004] In view of this, it is necessary to provide a magnetic flux concentrating rotor structure for use in a permanent magnet synchronous motor to overcome the deficiencies of the prior art.

[0005] Summary of the Invention

[0006] The purpose of this case is to provide a magnetic rotor structure for permanent magnet synchronous motors, in which the magnetic steel components are fixed by an integrated rotor core, making the overall structure easy to process and assemble, and further improving the magnetic concentration capacity under the same magnet dosage and working conditions, so that the motor has a higher air gap magnetic density, improves the motor output torque capacity, and at the same time achieves the purpose of improving the motor salient pole ratio, motor reluctance torque and motor weak magnetic speed expansion capability.

[0007] Another object of the present invention is to provide a magnetic rotor structure suitable for an outer rotor or inner rotor motor structure. Since the magnetic steel assembly is fixed by the iron core of the integrated silicon steel sheet stack, there is no need to use a stainless steel sleeve or a carbon fiber protective sleeve for protection and fixation. The iron core is formed by stacking multiple layers of silicon steel sheets, and a plurality of T-shaped magnetic steel receiving grooves are arranged at intervals by a plurality of radial magnetic bridges so that each of the multiple layers of silicon steel sheets is formed into an integral structure, which is conducive to simplifying the overall manufacturing and assembly process. In accordance with the structural strength requirements, the magnetic steel receiving groove is not limited to open or closed. Each magnetic steel assembly is composed of two radial magnetic steels, such as tile-shaped bodies, and a rectangular tangential magnetic steel. The two radial magnetic steels are located on both sides of the tangential magnetic steel and abut against the tangential magnetic steel. By respectively accommodating the two radial magnetic steels in the magnetic steel receiving grooves on both sides of the tangential magnetic steel, the assembly can be easily completed. In addition, the two radial magnetic steels and the one tangential magnetic steel in the magnetic steel assembly are arranged in a T-shaped structure in a radial cross section of the iron core, and the bottom of the T-shaped magnetic steel assembly can face the air gap side of the motor. Therefore, while ensuring the same amount of magnets and the same working conditions, the magnetic concentration capacity can be improved, so that the motor has a higher air gap magnetic density, thereby improving the motor output torque capacity. In the same magnetic steel assembly, the tangential magnet is magnetized along the tangential direction, and the two radial magnets are magnetized along the radial direction respectively, and the magnetization directions of the two radial magnets are opposite to each other. This magnetization direction setting can improve the motor salient pole ratio, while achieving the purpose of improving the motor reluctance torque and improving the motor weak magnetic speed expansion capability. Furthermore, the two radial magnets corresponding to any two adjacent magnetic steel assemblies have the same magnetization direction and are connected by a radial magnetic bridge, which is beneficial to reducing magnet loss. On the other hand, in a single magnetic steel assembly, the two radial magnets are respectively in the form of a tile, and the tangential magnet is in the form of a rectangular parallelepiped, so as to facilitate assembly into the T-shaped magnet receiving groove. Of course, each radial magnet can also be composed of one or more rectangular parallelepipeds or one or more tile-shaped bodies to further reduce magnet loss.

[0008] To achieve the aforementioned objectives, the present invention provides a magnetic rotor structure comprising an iron core and a plurality of groups of magnetic steel assemblies. The iron core is formed by stacking multiple layers of silicon steel sheets and having a plurality of magnetic steel receiving slots arranged along a circumference of the iron core, wherein each magnetic steel receiving slot is T-shaped in a radial cross-section of the iron core, wherein a radial magnetic bridge is provided between any two adjacent magnetic steel receiving slots, and the radial magnetic bridge enables each silicon steel sheet to be integrally formed. The plurality of groups of magnetic steel assemblies are arranged in a ring on the iron core and correspondingly accommodated in the plurality of magnetic steel receiving slots, wherein each group of the plurality of groups of magnetic steel assemblies comprises two radial magnetic steels and one tangential magnetic steel, wherein the two radial magnetic steels are respectively located on both sides of the tangential magnetic steel along the circumference and abut against the tangential magnetic steel, wherein the two radial magnetic steels in each group of magnetic steel assemblies are magnetized in a radial direction and have opposite magnetization directions to each other, and the tangential magnetic steels are magnetized in a tangential direction along the circumference of the iron core and have opposite magnetization directions to the corresponding tangential magnetic steels in the adjacent magnetic steel assemblies of other groups.

[0009] In one embodiment, the magnetic flux concentrating rotor structure is used to construct a permanent magnet synchronous motor. The permanent magnet synchronous motor has a stator that is radially sleeved on the outside or inside of the magnetic flux concentrating rotor structure and has an air gap between the stator and the magnetic flux concentrating rotor structure.

[0010] In one embodiment, the multiple sets of magnetic steel components disposed on each silicon steel sheet are separated from each other by radial magnetic bridges.

[0011] In one embodiment, any two adjacent radial magnetic steels in the plurality of magnetic steel assemblies are adjacently disposed via corresponding radial magnetic bridges and have the same magnetizing direction.

[0012] In one embodiment, in each set of magnetic steel components, the two radial magnetic steels are respectively in the form of a tile, with the center of curvature of the tile facing the axis, and the tangential magnetic steel is in the form of a cuboid.

[0013] In one embodiment, each radial magnetic steel is composed of one or more rectangular parallelepipeds, or one or more tile-shaped bodies.

[0014] In one embodiment, each of the plurality of magnetic steel components has a T-shaped cross section in the radial direction of the core.

[0015] In one embodiment, each of the plurality of T-shapes includes a bottom formed by a side surface of the tangential magnetic steel, and the bottom faces an air gap side.

[0016] In one embodiment, the magnetic flux concentrating rotor structure is an outer rotor, and the radial cross-section of the iron core is hollow ring-shaped, with the bottom facing the inner circumference, and the inner circumference corresponds to the inner stator.

[0017] In one embodiment, the two radial magnetic steels and the tangential magnetic steel have surfaces on one side away from the axis that are aligned with each other along the circumferential direction.

[0018] In one embodiment, the magnetic flux concentrating rotor structure is an inner rotor, and the radial cross-section of the iron core is hollow ring-shaped, with the bottom facing the outer peripheral side, and the outer peripheral side corresponds to the outer stator.

[0019] In one embodiment, the two radial magnetic steels and the tangential magnetic steel have their surfaces close to the axis aligned with each other along the circumferential direction.

[0020] In one embodiment, the core further includes a plurality of circumferential magnetic bridges, each located at a bottom portion of the T-shaped magnetic steel receiving slots, and each circumferential magnetic bridge is assembled to abut against a side wall of the tangential magnetic steel.

[0021] In one embodiment, the iron core further includes a plurality of pairs of holding portions, each located at a bottom portion of the T-shaped magnet receiving slots, and each pair of holding portions is assembled to abut against a side wall of the tangential magnet.

[0022] In one embodiment, the magnetic rotor structure includes 2N magnetic steel components, including 4N radial magnetic steels and 2N tangential magnetic steels, where N is an integer and N≧1. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 shows a schematic diagram of a magnetic flux concentrating rotor structure applied to a permanent magnet synchronous motor according to a first preferred embodiment of the present invention;

[0024] FIG2 is a schematic diagram showing the arrangement and magnetization direction of each magnetic steel in the magnetic concentrating rotor structure according to the first preferred embodiment of the present invention;

[0025] FIG3 is a schematic diagram illustrating a single magnetic steel component corresponding to a magnetic steel receiving groove in the magnetic flux concentrating rotor structure according to the first preferred embodiment of the present invention;

[0026] FIG4 is a schematic diagram illustrating another exemplary embodiment of a single magnetic steel component corresponding to a magnetic steel receiving groove in the magnetic flux concentrating rotor structure according to the first preferred embodiment of the present invention;

[0027] FIG5 is a schematic diagram illustrating another exemplary embodiment of a single magnetic steel component corresponding to a magnetic steel receiving groove in the magnetic flux concentrating rotor structure according to the first preferred embodiment of the present invention;

[0028] FIG6 shows a schematic diagram of a magnetic flux concentrating rotor structure applied to a permanent magnet synchronous motor according to a second preferred embodiment of the present invention;

[0029] FIG7 is a schematic diagram showing the arrangement and magnetization direction of each magnetic steel in the magnetic concentrating rotor structure according to the second preferred embodiment of the present invention;

[0030] FIG8 is a schematic diagram illustrating a single magnetic steel component corresponding to a magnetic steel receiving groove in the magnetic flux concentrating rotor structure according to the second preferred embodiment of the present invention.

[0031] Explanation of the Figure Numbers 1, 1a: Permanent magnet synchronous motor 2, 2a: Magnetic rotor structure 10: Iron core 11: Magnetic steel receiving groove 110: Bottom 12: Radial magnetic bridge 13: Circumferential magnetic bridge 14: Grip 20, 20a, 20b, 20c: Magnetic steel assembly 200: Bottom 21: Tangential magnetic steel 22, 23, 22a, 23a: Radial magnetic steel 3, 3a: Stator C: Axis G: Air gap IG: Inner circumference OG: Outer circumference DETAILED DESCRIPTION

[0032] Some exemplary embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention is capable of various variations in different aspects without departing from the scope of the present invention, and the description and drawings therein are intended to be illustrative in nature and not limiting of the present invention. In addition, different embodiments of the present invention may use repeated reference symbols and / or markings. This repetition is for the purpose of simplicity and clarity and is not intended to limit the relationship between the various embodiments and / or the described appearance structures. Furthermore, to facilitate descriptions of the relationship between one component or feature and another component(s) or feature(s) in the drawings, spatially relative terms such as "bottom," "left," "right," "inside," "outside," and similar terms may be used. In addition to the orientations shown in the drawings, spatially relative terms are used to cover different orientations of the device during use or operation. The device may also be positioned differently (e.g., rotated 90 degrees or in other orientations), and the description of the spatially relative terms used should be interpreted accordingly. In addition, when a component is referred to as being "connected to" or "coupled to" another component, it may be directly connected to or coupled to the other component, or there may be intervening components. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] Refer to Figures 1 to 3. This case provides a magnetic rotor structure 2 applied to a permanent magnet synchronous motor 1. The permanent magnet synchronous motor 1 includes a magnetic rotor structure 2 and a stator 3. This embodiment constitutes an outer rotor and an inner stator structure. The magnetic rotor structure 2 and the stator 3 are mutually nested and there is an air gap G between them. The outer side of the magnetic rotor structure 2 away from the axis C can be nested with a rotating shaft (not shown) to output the torque generated by the operation. In this embodiment, the magnetic rotor structure 2 includes an iron core 10 that is generally hollow and annular, and a plurality of groups of magnetic steel assemblies 20. It should be noted that the iron core 10 is formed by stacking multiple layers of silicon steel sheets. The number of multi-layer silicon steel sheets can vary depending on the height requirement of the magnetic steel assembly 20 in the axial direction of the motor. It is not a necessary feature that limits this case and is explained first. In this embodiment, each silicon steel sheet has a hollowed-out structure, so that the stacked core 10 has a plurality of magnetic steel receiving slots 11 arranged along the circumferential direction of the core 10, wherein each of the plurality of magnetic steel receiving slots 11 has a T-shaped cross-section in a radial direction of the core 10. In this embodiment, a radial magnetic bridge 12 is provided between any two adjacent ones of the plurality of magnetic steel receiving slots 11. By configuring the plurality of radial magnetic bridges 12, each of the multi-layer silicon steel sheets is integrally formed, which can strengthen the silicon steel sheet structure and facilitate simplifying the overall assembly process. In this embodiment, a plurality of groups of magnetic steel assemblies 20 are arranged in a ring in the circumferential direction of the core 10 and are correspondingly accommodated in the plurality of magnetic steel receiving slots 11. The plurality of groups of magnetic steel assemblies 20 are separated from each other by the radial magnetic bridges 12. Since the magnetic steel assembly 20 can be fixed by the iron core 10 of the integrated silicon steel sheet stack, there is no need to use a stainless steel sleeve or a carbon fiber protective sleeve for protection and fixation, which can strengthen the assembly structure of the magnetic steel assembly 20 and help simplify the overall assembly process.

[0034] In this embodiment, each of the multiple magnetic steel assemblies 20 includes two radial magnets 22 and 23 and one tangential magnet 21. The two radial magnets 22 and 23 are respectively located on the left and right sides of the tangential magnet 21 along the circumferential direction and abut the corresponding side surfaces of the tangential magnet 21. In this embodiment, within each magnetic steel assembly, the two radial magnets 22 and 23 are magnetized radially and have opposite magnetizing directions, for example, one magnetized toward the axis C and the other magnetized away from the axis C. Both of these directions are defined as radial. Furthermore, the tangential magnet 21 is magnetized tangentially and has opposite magnetizing directions from the corresponding tangential magnet 21 in the adjacent magnetic steel assembly 20, for example, one magnetized clockwise and the other magnetized counterclockwise. Both of these directions are defined as tangential. For example, in the magnetic steel assembly 20a shown in FIG2 , the tangential magnetic steel 21 is magnetized toward the left, the radial magnetic steel 22 located to the left of the tangential magnetic steel 21 is magnetized toward the axis C, and the radial magnetic steel 23 located to the right of the tangential magnetic steel 21 is magnetized away from the axis C. For another example, in another adjacent magnetic steel assembly 20b, the tangential magnetic steel 21 is magnetized toward the right, the radial magnetic steel 22 located to the left of the tangential magnetic steel 21 is magnetized away from the axis C, and the radial magnetic steel 23 located to the right of the tangential magnetic steel 21 is magnetized toward the axis C. Referring to FIG1 and FIG2 , because the corresponding tangential magnetic steel 21 in the same magnetic steel assembly 20 , 20a , or 20b is magnetized tangentially and the two radial magnetic steels 22 and 23 are magnetized radially, and the magnetization directions of the two radial magnetic steels 22 and 23 are opposite, the motor saliency ratio can be increased, thereby achieving the goals of increasing the motor's reluctance torque and improving the motor's field-weakening speed-expanding capability.

[0035] Furthermore, in this embodiment, any two adjacent radial magnets 22 and 23 in the multiple magnetic steel assemblies 20, namely, the radial magnets 23 of magnetic steel assembly 20a and the corresponding radial magnets 22 of magnetic steel assembly 20b as shown in FIG2 , are adjacently arranged via a radial magnetic bridge 12. The two radial magnets 23 and 22 have the same magnetization direction, i.e., magnetized away from the axis C. Based on this configuration, since the radial magnets 22 and 23 corresponding to adjacent magnetic steel assemblies 20a and 20b have the same magnetization direction and are connected by the radial magnetic bridge 12, magnet loss is reduced.

[0036] To ensure that the multiple sets of magnetic steel assemblies 20 meet the aforementioned magnetization conditions, the number of magnetic steel assemblies 20 is arranged in an even number, and the multiple sets of magnetic steel assemblies 20 can be symmetrically arranged on the iron core 10. In this embodiment, ten sets of magnetic steel assemblies 20 are respectively accommodated in ten T-shaped magnetic steel receiving slots 11, and the ten sets of magnetic steel assemblies 20 are composed of twenty radial magnetic steels 22 and 23 and ten tangential magnetic steels 21. In other embodiments, 2N magnetic steel assemblies 20 are included, with 4N radial magnetic steels 22 and 23 and 2N tangential magnetic steels 21, where N is an integer and N ≥ 1. Of course, the number of tangential magnetic steels 21 and radial magnetic steels 22 and 23 can be adjusted according to actual application requirements and the present invention is not limited to this.

[0037] In this embodiment, the core 10 further includes a plurality of circumferential magnetic bridges 13 located at a bottom portion 110 of the T-shaped magnet receiving slots 11, forming a closed receiving slot. Specifically, the magnet receiving slots 11 are surrounded by the radial magnetic bridges 12 and the circumferential magnetic bridges 13, forming a specific groove structure within the core 10. The circumferential magnetic bridges 13 are assembled to abut the sidewalls of the tangential magnets 21. This design further strengthens the core 10 structure. Furthermore, within a single magnet assembly 20, the two radial magnets 22 and 23 each have a tile-like shape, with their center of curvature oriented toward the axis C. The tangential magnet 21 is a rectangular parallelepiped, facilitating assembly within the T-shaped magnet receiving slot 11. The radial magnets 22 and 23 respectively abut the left and right sides of the tangential magnet 21, and are more snugly arranged around the circumference of the core 10. In other words, each of the multiple sets of magnetic steel components 20 has a T-shaped cross-section in a radial direction of the iron core 10. In this embodiment, each of the multiple sets of magnetic steel components 20 includes a bottom 200, which is composed of a side surface of the tangential magnetic steel 21 in the long direction and close to the axis C, and the bottom 200 faces the air gap side where the air gap G is located, which in this embodiment is the inner peripheral side IG of the magnetic rotor structure 2, wherein the inner peripheral side IG faces the inside of the axis C and is correspondingly provided with a stator 3 (refer to Figures 1 and 2). The two radial magnetic steels 22 and 23 and the tangential magnetic steel 21 are aligned with each other on the side surface away from the axis C along the circumferential direction. Therefore, while ensuring the same amount of magnets and the same working conditions, the magnetic concentration capacity can be improved, so that the motor has a higher air gap magnetic density, thereby improving the motor output torque capacity.

[0038] Please refer to Figure 4. It discloses another exemplary embodiment of the magnet receiving groove corresponding to a single magnet assembly in a magnetic rotor structure, wherein each group of magnet assemblies 20c is composed of three radial magnets 22a, three radial magnets 23a and one tangential magnet 21. In addition, the T-shaped magnet receiving groove 11 passes through the upper and lower surfaces of the iron core 10 in the axial direction, which facilitates the insertion and assembly of the tangential magnets 21, radial magnets 22a, and 23a. The three radial magnets 22a or the three radial magnets 23a are respectively composed of three rectangular magnets. The three connected rectangular magnets have the same magnetization direction, which is radially magnetized in this example. For example, the three radial magnets 22a can be magnetized in the direction toward the axis C, and the three radial magnets 23a can be magnetized in the direction away from the axis C. Compared with the long arc-shaped tile-shaped body shown in the corresponding embodiment of Figure 3, the combination of multiple small rectangular magnets in this example has lower manufacturing costs and simpler processing technology. Furthermore, connecting multiple small rectangular magnets further helps reduce magnet losses. In other embodiments, each radial magnet 22a, 23a can be composed of one or more rectangular blocks, or one or more tile-shaped bodies, to further reduce magnet losses. Of course, the number and type of radial magnets 22a, 23a in each magnetic assembly 20c can be adjusted according to actual application requirements and are not limited to this embodiment. The surfaces of the two radial magnets 22a, 23a and the tangential magnet 21, facing away from the axis C, are aligned along the circumferential direction.

[0039] Please refer to Figure 5 again. It discloses another example of a single magnetic steel component corresponding to a magnetic steel receiving groove in a magnetic rotor structure. The difference from the structure shown in Figure 3 is that the iron core 10 of this example does not have a circumferential magnetic bridge 13, but includes multiple pairs of holding portions 14, which are respectively located at a bottom 110 of a T-shape of multiple magnetic steel receiving grooves 11. Each pair of holding portions 14 is assembled to abut the side wall of the corresponding tangential magnetic steel 21 to form an open receiving groove. Therefore, under the condition of meeting the structural strength, it helps to reduce the weight of the iron core 10, and helps to reduce the leakage magnetic flux of the iron core 10, thereby improving the output torque capacity of the motor. Of course, the type of the magnetic steel receiving groove 11 can be adjusted according to the actual application requirements, and different modes can be combined and changed. This case is not limited to this and will not be repeated. The two radial magnetic steels 22, 23 and the tangential magnetic steel 21 are aligned with each other on the side surface away from the axis C along the circumferential direction.

[0040] Referring to Figures 6 to 8, in this embodiment, the permanent magnet synchronous motor 1a and the magnetic rotor structure 2a are similar to the permanent magnet synchronous motor 1 and the magnetic rotor structure 2 shown in Figures 1 to 3, and the same component numbers represent the same components, structures and functions, which will not be repeated here. In this embodiment, the permanent magnet synchronous motor 1a is an inner rotor and outer stator structure, including a magnetic rotor structure 2a and a stator 3a, and the magnetic rotor structure 2a and the stator 3a are mutually nested with an air gap G between them. The magnetic rotor structure 2a can be nested on the inner side of the axis C to output the torque generated by the operation (not shown). In this embodiment, the magnetic rotor structure 2a generally includes a solid circular iron core 10 and a plurality of groups of magnetic steel assemblies 20. In this embodiment, in each group of magnetic steel assemblies 20, two radial magnetic steels 22 and 23 are respectively located on the left and right sides of the tangential magnetic steel 21 along the circumferential direction and abut against the tangential magnetic steel 21. Referring to FIG. 7 , within magnetic assembly 20 a , the tangential magnet 21 is magnetized toward the left, the radial magnet 22 to the left of the tangential magnet 21 is magnetized toward the axis C, and the radial magnet 23 to the right of the tangential magnet 21 is magnetized away from the axis C. Furthermore, within adjacent magnetic assembly 20 b , the tangential magnet 21 is magnetized toward the right, the radial magnet 22 to the left of the tangential magnet 21 is magnetized away from the axis C, and the radial magnet 23 to the right of the tangential magnet 21 is magnetized toward the axis C. Referring to FIG. 6 and FIG. 7 , because the tangential magnet 21 in the same magnetic assembly 20 , 20 a , or 20 b is magnetized tangentially, the corresponding two radial magnets 22 and 23 are magnetized radially, and the magnetization directions of the two radial magnets 22 and 23 are opposite, thereby increasing the motor's saliency ratio, thereby simultaneously improving the motor's reluctance torque and enhancing the motor's field-weakening speed-expansion capability.

[0041] Furthermore, in this embodiment, as shown in Figures 7 and 8 , the radial magnets 23 of the magnetic assembly 20a and the corresponding radial magnets 22 of the adjacent magnetic assembly 20b are adjacently arranged via a radial magnetic bridge 12 and have the same magnetization direction, i.e., magnetized away from the axis C. Because the corresponding radial magnets 22 and 23 in the adjacent magnetic assemblies 20a and 20b have the same magnetization direction and are connected by the radial magnetic bridge 12, magnet loss is reduced. The surfaces of the two radial magnets 22 and 23 and the tangential magnet 21 on the side closest to the axis C are aligned along the circumferential direction.

[0042] Furthermore, in this embodiment, the core 10 further includes a plurality of circumferential magnetic bridges 13, each located at a bottom portion 110 of the T-shaped magnet receiving slots 11. The circumferential magnetic bridges 13 abut the sidewalls of the tangential magnets 21 to form a closed receiving slot. Specifically, the magnet receiving slots 11 are surrounded by the radial magnetic bridges 12 and the circumferential magnetic bridges 13, forming a specific groove structure within the core 10. This design further strengthens the core 10 structure. Furthermore, within a single magnetic assembly 20, the two radial magnetic steels 22 and 23 each have a tile-like shape, with their center of curvature oriented toward the axis C. The tangential magnet 21 is a rectangular parallelepiped, facilitating assembly within the T-shaped magnet receiving slots 11. This results in each of the multiple magnetic steel assemblies 20 having a T-shaped cross-section in the radial direction of the core 10. In this embodiment, each of the multiple magnetic steel assemblies 20 includes a bottom portion 200 formed by a side surface tangential to the longitudinal direction of the magnetic steel 21 and away from the axis C. The bottom portion 200 faces the air gap side where the air gap G is located, namely, the outer peripheral side OG of the magnetic flux concentrating rotor structure 2a. The outer peripheral side OG is located away from the axis C and corresponds to the stator 3a (see Figures 6 and 7). This improves the magnetic flux concentration capability while maintaining the same magnet dosage and operating conditions, resulting in a higher air gap flux density and, consequently, improved motor output torque.

[0043] In summary, the present invention provides a magnetic rotor structure for use in permanent magnet synchronous motors, wherein the magnetic steel components are fixed by an integrated rotor core, making the overall structure easy to process and assemble, and further improving the magnetic concentration capability under the same magnet dosage and working conditions, so that the motor has a higher air gap magnetic density, improves the motor output torque capability, and simultaneously achieves the purpose of improving the motor salient pole ratio, the motor reluctance torque, and the motor weak magnetic speed expansion capability. The magnetic rotor structure of the present invention is suitable for outer rotor or inner rotor motor structures. Since the magnetic steel components are fixed by the core of the integrated silicon steel sheet stack, there is no need to use a stainless steel sleeve or a carbon fiber protective sleeve to protect and fix the magnetic steel. The core is formed by stacking multiple layers of silicon steel sheets, and multiple T-shaped magnetic steel receiving slots are arranged at intervals by multiple radial magnetic bridges so that each of the multiple layers of silicon steel sheets is formed into an integral structure, which is conducive to simplifying the overall manufacturing and assembly process. Under the premise of meeting the structural strength requirements, the magnetic steel receiving slots are not limited to open or closed types. Each magnetic steel assembly is composed of two radial magnetic steels, such as tile-shaped bodies, and a rectangular tangential magnetic steel. The two radial magnetic steels are located on both sides of the tangential magnetic steel and abut against the tangential magnetic steel. By respectively accommodating the two radial magnetic steels in the magnetic steel accommodating grooves on both sides of the tangential magnetic steel, assembly can be easily completed. In addition, the two radial magnetic steels and one tangential magnetic steel in the magnetic steel assembly are arranged in a T-shaped structure in a radial cross-section of the iron core, and the bottom of the T-shaped magnetic steel assembly can face the air gap side of the motor. Therefore, while ensuring the same amount of magnets and the same operating conditions, the magnetic concentration capacity can be improved, so that the motor has a higher air gap magnetic density, thereby improving the motor output torque capacity. In the same magnetic steel assembly, the tangential magnetic steel is magnetized tangentially, and the two radial magnetic steels are magnetized radially respectively, and the magnetization directions of the two radial magnetic steels are opposite to each other. This magnetization direction setting can improve the motor salient pole ratio, while achieving the purpose of improving the motor reluctance torque and improving the motor weak magnetic expansion capability. Furthermore, the two radial magnets in any two adjacent magnet assemblies have the same magnetization direction and are connected by a radial magnetic bridge, which helps reduce magnet loss. Furthermore, within a single magnet assembly, the two radial magnets are each tile-shaped, while the tangential magnet is a rectangular parallelepiped, facilitating assembly into the T-shaped magnet receiving slot. Of course, each radial magnet can also be composed of one or more rectangular parallelepipeds or one or more tile-shaped bodies, further reducing magnet loss.

[0044] The present invention may be modified in various ways by those skilled in the art, but all of these modifications are within the scope of the protection intended by the appended claims.

Claims

1. A magnetic concentrating rotor structure, comprising: An iron core formed by stacking multiple layers of silicon steel sheets and having a plurality of magnetic steel receiving slots arranged along a circumference of the iron core, wherein each of the plurality of magnetic steel receiving slots has a T-shaped cross-section in the radial direction of the iron core, and a radial magnetic bridge is formed between any two adjacent ones of the plurality of magnetic steel receiving slots, wherein the plurality of radial magnetic bridges integrally form each of the plurality of silicon steel sheets; and A plurality of magnetic steel components are arranged in a ring on the iron core and are correspondingly accommodated in the plurality of magnetic steel accommodating grooves. Each group of the plurality of magnetic steel assemblies includes two radial magnetic steels and one tangential magnetic steel, wherein the two radial magnetic steels are respectively located on both sides of the tangential magnetic steel along the circumferential direction and abut against the tangential magnetic steel; wherein the two radial magnetic steels in each set of the magnetic steel assemblies are magnetized along the radial direction and have opposite magnetization directions; and The tangential magnetic steel is magnetized along the tangential direction of the circumference of the iron core, and has a magnetization direction opposite to that of the corresponding tangential magnetic steel in another adjacent magnetic steel assembly.

2. The magnetic flux concentrating rotor structure according to claim 1 is used to construct a permanent magnet synchronous motor, wherein the permanent magnet synchronous motor has a stator, which is radially sleeved on the outside or inside of the magnetic flux concentrating rotor structure and has an air gap between the stator and the magnetic flux concentrating rotor structure. 3 . The magnetic flux concentrating rotor structure according to claim 1 , wherein the plurality of magnetic steel assemblies disposed on each of the plurality of silicon steel sheets are separated from each other by the plurality of radial magnetic bridges.

4. The magnetic flux concentrating rotor structure according to claim 1, wherein the radial magnetic steels of any two adjacent magnetic steel assemblies are adjacently arranged through the corresponding radial magnetic bridges and have the same magnetizing direction.

5. The magnetic rotor structure according to claim 1, wherein in each group of the magnetic steel components, the two radial magnetic steels are respectively in the form of tiles, the center of curvature of the tile-shaped bodies is toward the axis, and the tangential magnetic steel is in the form of a rectangular parallelepiped.

6. The magnetic flux concentrating rotor structure according to claim 1, wherein in each set of the magnetic steel components, each of the two radial magnetic steels is composed of one or more rectangular parallelepipeds, or one or more tile-shaped bodies. 7 . The magnetic flux concentrating rotor structure according to claim 1 , wherein a cross section of each of the plurality of magnetic steel components in the radial direction of the iron core is T-shaped.

8. The magnetic flux concentrating rotor structure according to claim 7, wherein the T-shape includes a bottom formed by the side surfaces of the tangential magnetic steel, and the bottom faces the air gap side.

9. The magnetic flux concentrating rotor structure according to claim 8, wherein the magnetic flux concentrating rotor structure is an outer rotor, the cross section of the iron core along the radial direction is a hollow ring, the bottom faces the inner circumference, and the inner circumference is correspondingly provided with an inner stator.

10. The magnetic flux concentrating rotor structure according to claim 9, wherein the side surfaces of the two radial magnetic steels and the tangential magnetic steel away from the axis are aligned with each other along the circumferential direction.

11. The magnetic flux concentrating rotor structure according to claim 8, wherein the magnetic flux concentrating rotor structure is an inner rotor, the cross section of the iron core along the radial direction is a hollow ring, the bottom faces the outer peripheral side, and the outer peripheral side is correspondingly provided with an outer stator.

12. The magnetic flux concentrating rotor structure according to claim 11, wherein the side surfaces of the two radial magnetic steels and the tangential magnetic steel close to the shaft center are aligned with each other along the circumferential direction.

13. The magnetic rotor structure according to claim 1, wherein the iron core further comprises a plurality of circumferential magnetic bridges, respectively located at the bottom of the T-shape of the plurality of magnetic steel accommodating grooves, and each of the plurality of circumferential magnetic bridges is assembled to abut the side wall of the corresponding tangential magnetic steel.

14. The magnetic rotor structure according to claim 1, wherein the iron core further comprises a plurality of pairs of holding portions, each of which is located at the bottom of the T-shape of the plurality of magnetic steel receiving grooves, and each of the plurality of holding portions is assembled to abut the side wall of the corresponding tangential magnetic steel.

15. The magnetic rotor structure according to claim 1 comprises 2N magnetic steel assemblies, and has 4N radial magnetic steels and 2N tangential magnetic steels, wherein N is an integer and N≧1.

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