Stator structure and axial flux permanent magnet electric motor

Abstract

Disclosed in the present invention are a stator structure and an axial flux permanent magnet electric motor. The stator structure for the axial flux permanent magnet electric motor comprises a yoke structure and a plurality of tooth structures, wherein the plurality of tooth structures are connected to the yoke structure; a tooth slot is formed between every two adjacent tooth structures, and a slot opening structure is provided at the middle position of each tooth structure in an axial direction; the slot opening structure does not penetrate the tooth structure or penetrates the tooth structure and the yoke structure in the axial direction. When the slot opening structure does not penetrate the tooth structure in the axial direction, the end of the slot opening structure opposite to the yoke structure in the axial direction is spaced apart from the top of the tooth structure. When the slot opening structure penetrates the tooth structure and the yoke structure in the axial direction, the stator structure is divided into a plurality of first iron core segments; the first iron core segments are formed by means of radial lamination, and the plurality of first iron core segments are assembled together to form the stator structure.

Description

Stator structure and axial flux permanent magnet motor Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a stator structure and an axial flux permanent magnet motor. Background Technology

[0002] An axial flux permanent magnet motor is a new type of motor, also known as a diameter flux motor. It is a permanent magnet synchronous motor in which the axial flux direction of the inner and outer rotors is perpendicular to the rotation axis. The inner and outer rotors of the axial flux motor are composed of several stacked iron cores and coils, and operate in a flux channel with high flux density.

[0003] However, the stator core of the axial flux permanent magnet motor is made of silicon steel sheets wound together. The winding process causes the silicon steel sheets to be constantly subjected to bending stress, which will degrade the performance of the silicon steel sheets.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Technical issues

[0005] The main objective of this invention is to provide a stator structure and an axial flux permanent magnet motor, which aims to solve the problem that the stator core of the existing axial flux permanent magnet motor is made of silicon steel sheets wound together, which causes the silicon steel sheets to be constantly subjected to bending stress, resulting in the deterioration of the silicon steel sheet performance. Technical solutions

[0006] To achieve the above objectives, the present invention provides a stator structure for an axial flux permanent magnet motor, the stator structure comprising:

[0007] yoke structure;

[0008] Multiple toothed structures are connected to the yoke structure. A tooth groove is formed between two adjacent toothed structures. A slotted structure is provided in the middle position of each toothed structure along the axial direction. The slotted structure either does not penetrate the toothed structure or penetrates both the toothed structure and the yoke structure along the axial direction.

[0009] Wherein, when the slit structure does not penetrate the tooth structure along the axial direction, the end of the slit structure opposite to the yoke structure along the axial direction is spaced apart from the top of the tooth structure;

[0010] When the slotted structure penetrates the toothed structure and the yoke structure along the axial direction, the stator structure is divided into multiple first segmented iron cores. The first segmented iron cores are formed by radial lamination, and multiple first segmented iron cores are spliced ​​together to form the stator structure.

[0011] Preferably, in the stator structure for the axial flux permanent magnet motor, when the slotted structure does not penetrate the tooth structure along the axial direction, the other end of the slotted structure extends along the axial direction toward the yoke structure and does not exceed the bottom of the tooth groove, and the distance between the top of the slotted structure and the top of the tooth structure is L, where L≥2mm;

[0012] And / or, the circumferential width of the slit structure is H, 0.2mm≤H≤0.5mm.

[0013] Preferably, in the stator structure for the axial flux permanent magnet motor, when the slotted structure passes through the toothed structure and the yoke structure axially, two adjacent first segmented iron cores are positioned together at the yoke structure by a positioning structure.

[0014] Two adjacent first-section iron cores are spliced ​​together to form a splicing gap, the width of which is A, A≤0.2mm.

[0015] Preferably, in the stator structure for the axial flux permanent magnet motor, each first segment core has a first mating structure on one side of the slotted structure located at the yoke structure, and a first concave-convex structure on the other side; during installation, the first mating structures of two adjacent first segment cores are inserted into the first concave-convex structure of another.

[0016] Preferably, in the stator structure for the axial flux permanent magnet motor, each first segment core has a recessed structure on both sides of the slotted structure located at the yoke structure. After two adjacent first segment cores are spliced ​​together, the recessed structures of the two adjacent first segment cores form a cylindrical space.

[0017] A magnetically conductive metal component is installed in the cylindrical space, and both ends of the magnetically conductive metal component extend out of the cylindrical space to extend into the grooves inside and outside the housing of the axial flux permanent magnet motor, respectively.

[0018] After the magnetically conductive metal component is installed, it is fixed with potting compound.

[0019] Preferably, in the stator structure for the axial flux permanent magnet motor, each first segment core comprises a plurality of silicon steel sheets formed by radial lamination.

[0020] Preferably, in the stator structure for the axial flux permanent magnet motor, when the slotted structure does not penetrate the tooth structure axially, the slotted structure includes a first segment and a second segment. The first segment extends circumferentially from the bottom of the tooth groove towards the middle position of the tooth structure. The second segment is connected to the first segment and extends from the end of the first segment toward the bottom of the yoke structure. The second segment passes through the middle position of the tooth structure and extends axially downwards at the yoke structure.

[0021] The slotted structure divides the stator structure into multiple second-section iron cores, which are then spliced ​​together.

[0022] Preferably, in the stator structure for the axial flux permanent magnet motor, each second segment core has a second mating structure on one side of the second section and a second concave-convex structure on the other side. During installation, the second mating structures of two adjacent second segment cores are inserted into the second concave-convex structure of another.

[0023] The joint between the second mating structure and the second concave-convex structure is located in a low magnetic density region.

[0024] Preferably, the axial thickness of the yoke structure of the second segmented iron core does not exceed the width of the tooth structure of the second segmented iron core; or,

[0025] The second mating structure and the surface where the second concave-convex structure is located are arranged parallel to the axial direction.

[0026] Preferably, in the stator structure for the axial flux permanent magnet motor, the slotted structure divides the stator structure into multiple second segmented iron cores, which are spliced ​​together. Each second segmented iron core includes the tooth structure and a transverse arm. The transverse arm is located at the bottom of the tooth structure. The transverse arm has a first side and a second side on both sides along the circumferential direction. The first side is located within the circumferential dimension of the tooth structure, and the second side is located outside the circumferential dimension of the tooth structure.

[0027] The first side of the transverse arm of one of the second segment iron cores is in contact with the second side of the transverse arm of the other second segment iron core;

[0028] The transverse arms of multiple second segment iron cores fit together to form the yoke structure of the stator structure, and tooth grooves are formed between the tooth structures of two adjacent second segment iron cores.

[0029] Preferably, in the stator structure for the axial flux permanent magnet motor, the first side and the second side extend axially and are perpendicular to the top of the tooth structure.

[0030] Preferably, in the stator structure for the axial flux permanent magnet motor, the second segmented core is formed by stacking multiple silicon steel sheets radially.

[0031] Preferably, in the stator structure for the axial flux permanent magnet motor, the tooth slot width is the same in the radial direction.

[0032] Preferably, in the stator structure for the axial flux permanent magnet motor, the first side is located below the circumferential central axis of the tooth structure.

[0033] Preferably, in the stator structure for the axial flux permanent magnet motor, a plug-in structure is provided between the first side and the second side, the plug-in structure including a second mating structure provided on the first side and a second concave-convex structure provided on the second side.

[0034] When two adjacent second-section iron cores are spliced ​​together, the second mating structure on the first side of one second-section iron core is inserted into the second concave-convex structure on the second side of the other second-section iron core; or, the second concave-convex structure on the second side of one second-section iron core is inserted into the second mating structure on the first side of the other second-section iron core and then spliced ​​together.

[0035] Preferably, in the stator structure for the axial flux permanent magnet motor, the second mating structure is a recess and the second concave-convex structure is a convex part; or, the second mating structure is a convex part and the second concave-convex structure is a recess.

[0036] The recess and the convex portion are provided to extend radially.

[0037] Preferably, in the stator structure for the axial flux permanent magnet motor, one end of the recess is not fully penetrated radially and has a stop portion formed therein, while the other end is fully penetrated.

[0038] When two adjacent second-section iron cores are spliced ​​together, the stop is set at the stop after the protrusion of one second-section iron core is inserted into the concave part of the other second-section iron core.

[0039] Preferably, in the stator structure for the axial flux permanent magnet motor, when two adjacent second segment cores are spliced ​​together, a splicing gap is formed on the side of the transverse arm, and the width of the splicing gap is ≤0.2mm.

[0040] Preferably, in the stator structure for the axial flux permanent magnet motor, in the outer ring of the stator structure, the second side portion of the transverse arm extends beyond the radial dimension of the tooth structure of the adjacent second segmented iron core, and in the inner ring of the stator structure, the second side portion of the transverse arm is recessed within the radial dimension of the tooth structure of the adjacent second segmented iron core.

[0041] To achieve the above objectives, the present invention also provides an axial flux permanent magnet motor, the axial flux permanent magnet motor including the stator structure described above for an axial flux permanent magnet motor. Beneficial effects

[0042] The present invention provides a stator structure for an axial flux permanent magnet motor, wherein multiple tooth structures are connected to a yoke structure, and a tooth groove is formed between two adjacent tooth structures. Each tooth structure has an axially spaced slit structure at its middle position. The slit structure either does not penetrate the tooth structure or penetrates both the tooth structure and the yoke structure along the axial direction. When the slit structure does not penetrate the tooth structure, its end opposite to the yoke structure along the axial direction is spaced apart from the top of the tooth structure. When the slit structure penetrates both the tooth structure and the yoke structure along the axial direction, the stator structure is divided into multiple first segmented iron cores. These first segmented iron cores are formed by radially stacking laminations, and multiple first segmented iron cores are spliced ​​together to form the stator structure. This solves the problem in the prior art where the stator core of an axial flux permanent magnet motor is made of wound silicon steel sheets, which causes the silicon steel sheets to be constantly subjected to bending stress, leading to performance degradation.

[0043] Furthermore, setting a slotted structure in the middle of the tooth structure along the magnetic circuit direction has little impact on motor performance. The slotted structure can help to further reduce the eddy current loop in the tooth structure laminations, and can further reduce the eddy current loss of the iron core. Attached Figure Description

[0044] Figure 1 is a schematic diagram of a conventional stator structure in the prior art;

[0045] Figure 2 is a schematic diagram of the motor's magnetic circuit;

[0046] Figure 3 is a schematic diagram of the first embodiment of the stator structure of the axial flux permanent magnet motor of the present invention;

[0047] Figure 4 is a schematic diagram of the second embodiment of the stator structure of the axial flux permanent magnet motor of the present invention;

[0048] Figure 5 is a schematic diagram of radial lamination;

[0049] Figure 6 is a schematic diagram of the first segmented iron core of the present invention in one embodiment;

[0050] Figure 7 is a schematic diagram of Figure 6 from another perspective;

[0051] Figure 8 is a schematic diagram of the first segmented iron core of the present invention in another embodiment;

[0052] Figure 9 is a schematic diagram of the first segmented iron core in Figure 8 being installed into the housing;

[0053] Figure 10 is a schematic diagram of the decomposition of Figure 9;

[0054] Figure 11 is a schematic diagram of the shell in Figure 9;

[0055] Figure 12 is a schematic diagram of the third embodiment of the stator structure of the present invention for an axial flux permanent magnet motor;

[0056] Figure 13 is a schematic diagram of the second segmented iron core in Figure 12;

[0057] Figure 14 is a schematic diagram of Figure 13 from another perspective;

[0058] Figure 15 is a schematic diagram of Figure 13 from another perspective;

[0059] Figure 16 is a schematic diagram of the second segment of the iron core being inserted into the coil in Figure 13;

[0060] Figure 17 is a schematic diagram of Figure 12 from another perspective;

[0061] Figure 18 is a schematic diagram of the fourth embodiment of the stator structure of the present invention for an axial flux permanent magnet motor.

[0062] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Embodiments of the present invention

[0063] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0064] In this embodiment of the invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0065] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0066] In this embodiment of the invention, the term "multiple" refers to two or more, and other quantifiers are similar.

[0067] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0068] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0069] This invention provides a stator structure for an axial flux permanent magnet motor. As shown in Figure 3, the stator structure 100 for the axial flux permanent magnet motor includes a yoke structure 1 and a plurality of tooth structures 2. The plurality of tooth structures 2 are connected to the yoke structure 1. A tooth groove 3 is formed between two adjacent tooth structures 2. A slot structure 4 is provided at the middle position of each tooth structure 2 along the axial direction. The slot structure 4 either does not penetrate the tooth structure 2 or penetrates both the tooth structure 2 and the yoke structure 1 along the axial direction.

[0070] It should be noted that the middle position of the tooth structure 2 in this invention refers to the position of the center line of each tooth structure 2, which extends along the axial direction; rather than the approximate middle position of each tooth structure 2.

[0071] Figure 1 illustrates a conventional stator structure 100' in the prior art. Referring to Figure 1, the conventional stator structure 100' is formed by winding silicon steel sheets. Winding causes the silicon steel sheets to be constantly subjected to bending stress, which leads to the deterioration of the silicon steel sheet's performance.

[0072] The present invention addresses the problem of existing axial flux permanent magnet motor stator cores being made of wound silicon steel sheets. This wound process subjectes the silicon steel sheets to constant bending stress, leading to performance degradation. Figure 2 illustrates the motor's magnetic circuit. Referring to Figure 2, the magnetic circuit splits towards both sides of the yoke at the tooth bottom. Therefore, placing the slotted structure 4 in the middle of the tooth structure 2 along the magnetic circuit direction has minimal impact on motor performance. Furthermore, the slotted structure 4 helps to further reduce eddy current loops in the laminations of the tooth structure 2, thereby further reducing core eddy current losses. Additionally, the slotted structure 4 is easy to manufacture; like conventional wound cores, only the punch die needs to be changed.

[0073] Figure 3 illustrates a schematic diagram of the first embodiment of the stator structure 100 of the axial flux permanent magnet motor of the present invention. Referring to Figure 3, the slit structure 4 is provided along the axial direction without penetrating the tooth structure 2. The end of the slit structure 4 opposite to the yoke structure 1 along the axial direction is spaced apart from the top of the tooth structure 2. It is worth emphasizing that the slit structure 4 needs to be located in the middle position of the tooth structure 2, so as not to affect the magnetic circuit of the motor and the magnetic performance of the motor.

[0074] Furthermore, since the stator structure 100 is typically formed by winding silicon steel sheets, the silicon steel sheets will be subjected to stress when pulled during the winding process. Therefore, the slotted structure 4 cannot extend axially to the top of the toothed structure 2; otherwise, when the silicon steel sheets are subjected to stress, the stress on the yoke structure 1 will increase, and the top of the toothed structure 2 may break due to its excessive thinness. Specifically, the distance between the slotted structure 4 and the top of the toothed structure 2 is L, where L ≥ 2mm. The specific value of L needs to be considered in conjunction with electromagnetic simulation and process considerations to avoid the situation where the stress on the yoke structure 1 increases and the silicon steel sheets break during the winding process.

[0075] The other end of the slotted structure 4 extends axially toward the direction close to the yoke structure 1. The extension length cannot be too long, as this would affect the overall strength, while an extension length that is too short would not achieve the desired effect. In this embodiment, the other end of the slotted structure 4 extends axially toward the direction close to the yoke structure 1 and does not exceed the bottom of the tooth groove 3.

[0076] The circumferential width of the slotted structure 4 is H. If H is too small, it will be impossible to process due to limitations of punches and other processing tools; if H is too large, it will result in a large amount of empty space in the toothed structure 2, which will affect the motor performance and strength. Therefore, in this embodiment, 0.2mm ≤ H ≤ 0.5mm. Of course, without considering the limitations of punches and other processing tools, the smaller H is, the better.

[0077] Figure 4 illustrates a schematic diagram of a second embodiment of the stator structure 100 of the axial flux permanent magnet motor of the present invention. Figure 5 illustrates a schematic diagram of radial lamination. Referring to Figures 4 and 5, in Figure 4, the slotted structure 4 penetrates the toothed structure 2 and the yoke structure 1 axially, dividing the stator structure 100 into multiple first segmented iron cores 51. The first segmented iron cores 51 are formed by radial lamination, and the multiple first segmented iron cores 51 are spliced ​​together to form the stator structure 100. Specifically, each first segmented iron core 51 includes multiple silicon steel sheets formed by radial lamination.

[0078] It is worth noting that conventionally wound iron cores subject silicon steel sheets to constant bending stress, which leads to deterioration of the silicon steel sheet's performance and increased iron loss. In this embodiment of the invention, the iron core, originally formed by winding silicon steel sheets, is divided into sections. The first section of the iron core 51 is formed by radially stacked sheets, thus reducing the impact of this stress.

[0079] Furthermore, this invention, by setting a segmented iron core, allows for various shapes compared to a normal iron core, such as U-shaped, Z-shaped, or other irregular structures, offering greater flexibility and simplifying the manufacturing process. This is in contrast to existing technologies that use silicon steel sheets wound together.

[0080] It is worth noting that the boundary of the single first segment iron core 51 is located in the middle of the tooth structure 2, thus minimizing the impact on motor performance. During installation, after multiple first segment iron cores 51 are spliced ​​together to form a whole, they can be impregnated with paint as a whole, or the splice joints can be welded to fix them into a whole.

[0081] Each first segment core 51 may, but is not limited to, be a radially laminated structure formed by high-temperature curing of silicon steel sheets using riveting, gluing, or self-adhesive methods.

[0082] Two adjacent first segment iron cores 51 are positioned together at the yoke structure 1 by a positioning structure. This serves as a splicing and positioning mechanism. Specifically, the positioning structure can be a concave-convex structure for interlocking, or it can be a recessed structure 43 at the splicing point with a magnetically conductive metal part 6 in the middle, which can be set according to actual needs. The following will describe these two positioning structures in detail.

[0083] Figure 6 illustrates a schematic diagram of one embodiment of the positioning structure. Referring to Figure 6, each first segmented core 51 has a first mating structure 42 on one side of the slotted structure 4 located at the yoke structure 1, and a first concave-convex structure 41 on the other side. During installation, the first mating structures 42 of two adjacent first segmented cores 51 are inserted into the first concave-convex structure 41 of another. It should be noted that the first mating structure 42 and the first concave-convex structure 41 are located at the yoke structure 1 below the middle position of the toothed structure 2. More specifically, the first mating structure 42 and the second concave-convex structure 451 are located in the low magnetic density region 11 of the stator structure 100, thus minimizing the impact on motor performance. Referring to Figure 2, the normal motor magnetic circuit descends from the middle of the toothed structure 2, and at the junction of the toothed structure 2 and the yoke structure 1, the magnetic circuit shifts to both sides, forming a bifurcation area in the middle, which is the low magnetic density region 11.

[0084] The cross-sectional shape of the first mating structure 42 can be set as needed. For example, the first mating structure 42 can be a concave arc groove, a concave-convex arc groove, a square groove, etc. Correspondingly, the shape of the first concave-convex structure 41 matches the shape of the first mating structure 42. For example, if the first mating structure 42 is a concave arc groove, then the first concave-convex structure 41 is a convex arc structure that matches the concave arc groove. In this way, when the first mating structure 42 and the first concave-convex structure 41 are matched, the first concave-convex structure 41 can be perfectly accommodated within the first mating structure 42. Of course, there are no restrictions on which side of the first segmented iron core 51 is provided with the first mating structure 42 and which side is provided with the first concave-convex structure 41. It can be set as needed.

[0085] In addition, to facilitate accurate assembly and positioning, one end of the first mating structure 42 is usually not fully penetrated to form a stop portion 421, while the other end is fully penetrated. During installation, the first concave-convex structure 41 enters along the side of the first mating structure 42 that is fully penetrated, and the stop portion 421 indicates that the installation is in place. Which side is not fully penetrated can be determined based on installation habits. The fact that the first mating structure 42 is not fully penetrated effectively creates a limiting structure, facilitating positioning.

[0086] When two adjacent first segment iron cores 51 are spliced ​​together, a splicing gap is formed between the two adjacent first segment iron cores 51. The smaller the width of the splicing gap, the better; if the splicing gap is too large, it is equivalent to increasing the air gap of the motor, which will affect the output performance of the motor, such as causing a decrease in the output power of the motor. Therefore, in this embodiment, the width of the splicing gap is A, where A≤0.2mm.

[0087] Figure 8 illustrates another embodiment of the positioning structure. Referring to Figure 8, each first segment iron core 51 has a recessed structure 43 on both sides of the slotted structure 4 located at the yoke structure 1. After two adjacent first segment iron cores 51 are spliced ​​together, the recessed structures 43 of the two adjacent first segment iron cores 51 form a cylindrical space. A magnetically conductive metal part 6 is installed in the cylindrical space. The two ends of the magnetically conductive metal part 6 extend out of the cylindrical space to extend into the grooves inside and outside the housing 200 of the axial flux permanent magnet motor, respectively. After the magnetically conductive metal part 6 is installed, it is fixed by potting compound.

[0088] The cross-sectional shape of the recessed structure 43 can be set as needed. For example, the recessed structure 43 can be a square groove, an arc-shaped groove, etc. When the cross-section of the recessed structure 43 is square, the cylindrical space formed after splicing two adjacent first segment iron cores 51 is a cuboid or a cube, etc.; when the cross-section of the recessed structure 43 is arc-shaped, the cylindrical space formed after splicing two adjacent first segment iron cores 51 is a cylinder, etc.

[0089] During installation, the magnetically conductive metal part 6 is inserted into the cylindrical space, with both ends of the magnetically conductive metal part 6 extending out of the cylindrical space. Specifically, one end of the magnetically conductive metal part 6 extends towards and protrudes from the inner ring of the stator structure 100, while the other end extends towards and protrudes from the outer ring of the stator structure 100. As shown in Figures 9 to 11, when the stator structure 100 is installed onto the housing 200, both ends of the magnetically conductive metal part 6 extend into the corresponding grooves in the housing 200, serving as a unified positioning element. After the magnetically conductive metal part 6 is in place, potting compound is used to fix the stator structure 100 and the housing 200 into a single unit, strengthening the overall structural strength. Because the stator structure 100 is subjected to axial force and is attracted by magnets on the other side, the magnets will pull the positioning structure toward the magnet surface. Therefore, the positioning structure will bear a force that separates it from the housing 200. By setting potting compound, the stator structure 100 and the housing 200 are integrated. The force on the potting compound will also act on the magnetically conductive metal part 6, which can strengthen the overall structural strength.

[0090] Furthermore, dividing the stator structure 100 into blocks to form the first block core 51 will lead to a decrease in the overall structural strength. At the same time, the stator structure 100 in the axial motor will also be affected by the axial magnetic pull. Therefore, by setting the magnetic conductive metal part 6, the present invention can improve the overall structural strength and avoid structural deformation caused by the axial magnetic pull after the stator structure 100 is divided into blocks.

[0091] Furthermore, by pre-reserving a recessed structure 43 on each first segment iron core 51, a cylindrical space is formed after two adjacent first segment iron cores 51 are spliced ​​together. At this time, the magnetically conductive metal part 6 is inserted into the cylindrical space and then cured as a whole (e.g., impregnated with paint). The housing 200 is pre-reserved with grooves that match the two ends of the magnetically conductive metal part 6. When the two ends of the magnetically conductive metal part 6 are installed into the pre-reserved grooves of the housing 200 and the stator structure 100 is placed into the housing 200 as a whole, the stator structure 100 can be fixed inside the housing 200 by injecting sealant. In this way, the magnetically conductive metal part 6 bears the clamping force of the sealant and acts on each first segment iron core 51 at the same time.

[0092] It should be noted that during the potting compound application, the potting compound surface is lower than the surface of the first segment iron core 51. The potting compound flows into each of the first segment iron cores 51, serving both a sealing and heat dissipation function. If no potting compound is applied, an air gap will exist between the first segment iron core 51 and the shell 200, containing air. Air has poor thermal conductivity and cannot effectively dissipate heat; however, the potting compound, with its better thermal conductivity than air, effectively dissipates heat.

[0093] Furthermore, the shape of the magnetically conductive metal component 6 is not specifically limited here; it can be a cylindrical rod-shaped structure or a cubic rod-shaped structure. It is important to emphasize that the magnetically conductive metal component 6 is located in the low magnetic density region 11, thus minimizing its impact on motor performance. The material of the magnetically conductive metal component 6 is also not specifically limited here; for example, it can be 45# steel.

[0094] Figure 12 illustrates a third embodiment of the stator structure 100 for an axial flux permanent magnet motor according to the present invention. Referring to Figure 12, when the slotted structure 4 does not penetrate the tooth structure 2 axially, the slotted structure 4 includes a first segment 44 and a second segment 45. The first segment 44 extends circumferentially from the bottom of the tooth groove 3 towards the middle position of the tooth structure 2. The second segment 45 is connected to the first segment 44 and extends axially from the end of the first segment 44 towards the bottom of the yoke structure 1. The second segment 45 passes through the middle position of the tooth structure 2 and extends axially downwards towards the yoke structure 1. The slotted structure 4 divides the stator structure 100 into multiple second segmented cores 52, which are spliced ​​together. Each second segmented core 52 includes multiple radially stacked silicon steel sheets.

[0095] As shown in Figure 1, the coils of a conventional axial flux permanent magnet motor need to be inserted into the slot 3 one by one. The slot 3 is relatively small (usually around 3.5mm), and the coils (usually copper wires) that need to be inserted are usually 20, 60 or even more. Inserting them one by one is very inefficient.

[0096] As shown in Figure 14, this embodiment divides the stator structure 100 into multiple second segmented iron cores 52. This allows multiple coils to be inserted from the yoke direction, which improves winding efficiency. The coils can be inserted as a whole from the yoke direction; for example, 60 coils can be inserted at once.

[0097] Specifically, each second segment core 52 includes a tooth structure 2 and a transverse arm 521. The transverse arm 521 is located at the bottom of the tooth structure 2. The transverse arm 521 has a first side surface 5211 and a second side surface 5212 on both sides along the circumferential direction. The first side surface 5211 is located within the circumferential dimension of the tooth structure 2, and the second side surface 5212 is located outside the circumferential dimension of the tooth structure 2. The first side surface 5211 of the transverse arm 521 of one second segment core 52 is attached to the second side surface 5212 of the transverse arm 521 of another second segment core 52. The transverse arms 521 of multiple second segment cores 52 are attached to each other to form the yoke structure of the stator structure. A tooth groove 3 is formed between the tooth structures 2 of two adjacent second segment cores 52.

[0098] In addition, the present invention uses a segmented iron core, and the shape of the segmented iron core is more flexible. For example, it can be set into a Z-shape as shown in Figure 12. On the one hand, it solves the problem of bending stress in the traditional stator structure, and on the other hand, it makes it easier to fit the coil.

[0099] Specifically, the present invention provides a plurality of second segmented iron cores 52 in the stator structure 100. Each second segmented iron core 52 includes a tooth structure 2 and a transverse arm 521. The transverse arm 521 has a first side surface 5211 and a second side surface 5212 on both sides along the circumferential direction. The first side surface 5211 is located within the circumferential dimension of the tooth structure 2, and the second side surface 5212 is located outside the circumferential dimension of the tooth structure 2, forming a Z-shaped structure. This solves the problem of bending stress in the traditional stator structure and facilitates the insertion of the coil 300. The second segmented iron core 52 is formed by stacking multiple silicon steel sheets radially, which can further reduce the impact on the magnetic circuit.

[0100] More specifically, on the outer ring of the stator structure 100, the second side 5212 of the transverse arm 521 extends beyond the radial dimension of the tooth structure 2 of the adjacent second segment core 52, while on the inner ring of the stator structure 100, the second side 5212 of the transverse arm 521 is recessed within the radial dimension of the tooth structure 2 of the adjacent second segment core 52, thus forming a Z-shaped structure.

[0101] The width of the tooth groove 3 is the same in the radial direction. It should be noted that the radial direction mentioned in this invention refers to the radial direction of the stator structure 100 of the motor.

[0102] It is worth noting that there is an installation space on the side opposite to the transverse arm 521 at the bottom of the tooth structure 2. When two adjacent second segment iron cores 52 are spliced, the transverse arm 521 of one second segment iron core 52 extends into the installation space of the other second segment iron core 52, and then they are fixed together by plugging in the structure.

[0103] The first side surface 5211 can extend from approximately the center of the bottom of the tooth structure 2 in a direction away from the tooth structure 2, or it can extend from the center of the bottom of the tooth structure 2 in a direction away from the tooth structure 2 and perpendicular to the tooth structure 2. Since the first side surface 5211 and the second side surface 5212 of two adjacent second segment cores 52 are spliced ​​together, and the second side surface 5212 matches the first side surface 5211, the extension of the second side surface 5212 can refer to the first side surface 5211, which will not be described in detail here.

[0104] In this embodiment, the first side surface 5211 and the second side surface 5212 extend axially and are perpendicular to the top of the tooth structure 2. In other embodiments, the first side surface 5211 and the second side surface 5212 may be inclined relative to the axial direction. More specifically, the first side surface 5211 is located below the circumferential central axis of the tooth structure 2, so that when two adjacent second segment cores 52 are spliced, the splicing gap is located on the center line of the tooth structure 2, thus having less impact on the magnetic circuit.

[0105] It should be noted that regardless of how the first side 5211 and the second side 5212 extend, as long as the insertion structure on the first side 5211 and the second side 5212 is located at the middle position along the circumferential direction of the tooth structure 2, the impact on motor performance will be minimized. More specifically, the insertion structure is located in the low magnetic density region of the stator structure, thus further minimizing the impact on motor performance.

[0106] As shown in Figures 13 to 17, two adjacent second segment cores 52 are joined together using a concave-convex structure. Specifically, each second segment core 52 has a second mating structure 452 on one side of the second segment 45 and a second concave-convex structure 451 on the other side. During installation, the second mating structures 452 of two adjacent second segment cores 52 are inserted into the second concave-convex structure 451 of the other segment. The joint between the second mating structure 452 and the second concave-convex structure 451 is located in the low magnetic density region 11. By placing the joint between the second mating structure 452 and the second concave-convex structure 451 in the low magnetic density region 11, the impact on motor performance is minimized.

[0107] More specifically, the plug-in structure includes a second mating structure 452 provided on the first side 5211 and a second concave-convex structure 451 provided on the second side 5212; when two adjacent second segment iron cores 52 are spliced, the second mating structure 452 on the first side 5211 of one second segment iron core 52 is plugged into the second concave-convex structure 451 on the second side 5212 of the other second segment iron core 52; or, the second concave-convex structure 451 on the second side 5212 of one second segment iron core 52 and the second mating structure 452 on the first side 5211 of the other second segment iron core 52 are spliced ​​together after being plugged into the plug-in structure.

[0108] The shapes of the second mating structure 452 and the second concave-convex structure 451 are not specifically limited; they can be regular cylindrical structures, irregular cylindrical structures, or other pluggable structures. As long as they can be plugged together, they are acceptable. In this embodiment, the second mating structure 452 can be a concave portion and the second concave-convex structure 451 a convex portion; alternatively, the second mating structure 452 can be a convex portion and the second concave-convex structure 451 a concave portion. Both the concave and convex portions extend radially.

[0109] The cross-sectional shape of the second mating structure 452 can be set as needed, and the cross-sectional shape of the second concave-convex structure 451 matches the cross-sectional shape of the second mating structure 452.

[0110] In addition, for ease of installation, one end of the recess is not fully penetrated radially and has a stop structure, while the other end is fully penetrated; when two adjacent second segment iron cores 52 are spliced, the protrusion of one second segment iron core 52 is inserted into the recess of the other second segment iron core 52 and then abutted by the stop structure. During installation, the protrusion abutting on the stop structure is considered to indicate that the installation is in place.

[0111] When two adjacent second segment iron cores 52 are spliced ​​together, a splicing gap is formed on the side of the transverse arm 521. The smaller the width of the splicing gap, the better; if the splicing gap is too large, it is equivalent to increasing the air gap of the motor, which will affect the output performance of the motor, such as causing a decrease in the output power of the motor. Therefore, in this embodiment, the width of the splicing gap is ≤0.2mm.

[0112] In addition, the end of the transverse arm 521 away from the tooth structure 2 is set beyond the tooth structure 2 of the adjacent second segment iron core 52; in other embodiments, the end of the transverse arm 521 away from the tooth structure 2 may not exceed the tooth structure 2 of the adjacent second segment iron core 52, which can be set according to the processing technology.

[0113] Specifically, the arrangement of the first segment 44 and the second segment 45 can be such that the end of the first segment 44 does not reach the middle position of the tooth structure 2, and the second segment 45 extends obliquely from the end of the first segment 44 toward the bottom of the yoke structure 1; or the end of the first segment 44 is located at the middle position of the tooth structure 2, and the second segment 45 extends axially from the end of the first segment 44 to the bottom of the yoke structure 1. Regardless of the method, the second segment 45 must pass through the low magnetic density region 11 axially downward from the middle position of the tooth structure 2.

[0114] The cross-sectional shape of the second mating structure 452 can be set as needed. For example, the second mating structure 452 can be a concave arc groove, a concave-convex arc groove, a square groove, etc. Correspondingly, the shape of the second concave-convex structure 451 matches the shape of the second mating structure 452. For example, if the second mating structure 452 is a concave arc groove, then the second concave-convex structure 451 is a convex arc structure that matches the concave arc groove. In this way, when the second mating structure 452 and the second concave-convex structure 451 are matched, the second concave-convex structure 451 can be perfectly accommodated within the second mating structure 452. Of course, there are no restrictions on which side of the second segmented iron core 52 is provided with the second mating structure 452 and which side is provided with the second concave-convex structure 451; it can be set as needed.

[0115] Figure 16 shows a schematic diagram of the second segmented iron core 52 being fitted into the coil in Figure 13. Referring to Figure 16, the coil can be fitted into the yoke structure 1 of the second segmented iron core 52 from a position near the second segment 45, and then moved onto the tooth structure 2 of the second segmented iron core 52.

[0116] More specifically, the axial thickness of the yoke structure 1 of the second segmented iron core 52 does not exceed the width of the toothed structure 2 of the second segmented iron core 52. This facilitates the coil being fitted onto and moved onto the toothed structure 2 from a position near the second segment 45. Since the coil is fitted onto the toothed structure 2, the maximum width of the coil is the width of the toothed structure 2. Therefore, the axial thickness of the yoke structure 1 of the second segmented iron core 52 does not exceed the width of the toothed structure 2 of the second segmented iron core 52; otherwise, it would be impossible to fit it onto the toothed structure 2.

[0117] The second segmented iron core 52 provided by this invention includes a toothed structure 2 and a transverse arm 521 extending circumferentially from the middle of the bottom of the toothed structure 2 towards one side along the stator structure. This facilitates the direct insertion of the coil 300 through the transverse arm 521 and into the toothed structure 2. The second segmented iron core 52 provided by this invention not only solves the problem of bending stress in traditional stator structures but also facilitates the insertion of the coil 300.

[0118] Furthermore, the surfaces of the second mating structure 452 and the second concave-convex structure 451 are parallel to the axial direction, thus minimizing the contact area when the second mating structures 452 and 451 of two adjacent second segmented iron cores 52 are matched. When the surfaces of the second mating structure 452 and the second concave-convex structure 451 are inclined relative to the axial direction, the contact area when the second mating structures 452 and 451 of two adjacent second segmented iron cores 52 are matched increases, and the area of ​​the matching gap also increases, leading to a decrease in motor performance. The parallel orientation of the surfaces of the second mating structure 452 and the second concave-convex structure 451 to the axial direction effectively reduces the gap area.

[0119] The second mating structure 452 and the second concave-convex structure 451 are disposed on the yoke structure 1 near the middle and lower part of the yoke structure 1, that is, disposed on the yoke structure 1 away from the tooth structure 2. Theoretically, as can be seen from the magnetic circuit diagram in Figure 2, the closer the second mating structure 452 and the second concave-convex structure 451 are to the side of the yoke structure 1 away from the tooth structure 2 (i.e., the bottom of the yoke structure 1), the better. Therefore, while ensuring strength, the second mating structure 452 and the second concave-convex structure 451 can be disposed as close as possible to the bottom of the yoke structure 1.

[0120] Figure 18 illustrates a fourth embodiment of the stator structure 100 for an axial flux permanent magnet motor according to the present invention. It should be noted that the slit structure 4 is not shown in Figure 18. The specific configuration of the slit structure 4 can be referred to the specific configuration in the first embodiment of the stator structure 100 for an axial flux permanent magnet motor, and will not be described in detail here. As shown in Figure 18, the yoke structure 1 directly below the tooth groove 3 of the stator structure 100 can be separated to form a third segment 53. Specifically, a slit is made axially downward along the groove wall of the tooth groove 3 to obtain the third segment 53. During installation, the third segment 53 is installed to the corresponding position of the stator structure 100 to form the entire stator structure. This method facilitates the installation of the third segment 53 after the coil is inserted from the tooth structure 2, greatly improving the winding efficiency. In addition, positioning structures for matching with the yoke structure 1 are provided on both sides of the third segment 53. The positioning structures can adopt conventional concave-convex structures, which will not be described in detail here.

[0121] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. Based on the embodiments of the present invention, those skilled in the art can make other variations or modifications without creative effort, and all such variations or modifications should fall within the scope of protection of the present invention.

Claims

1. A stator structure for an axial flux permanent magnet electric machine, characterised in that, include: yoke structure; Multiple toothed structures are connected to the yoke structure. A tooth groove is formed between two adjacent toothed structures. A slotted structure is provided in the middle position of each toothed structure along the axial direction. The slotted structure either does not penetrate the toothed structure or penetrates both the toothed structure and the yoke structure along the axial direction. Wherein, when the slit structure does not penetrate the tooth structure along the axial direction, the end of the slit structure opposite to the yoke structure along the axial direction is spaced apart from the top of the tooth structure; When the slotted structure penetrates the toothed structure and the yoke structure along the axial direction, the stator structure is divided into multiple first segmented iron cores. The first segmented iron cores are formed by radial lamination, and multiple first segmented iron cores are spliced ​​together to form the stator structure.

2. A stator structure for an axial flux permanent magnet electric machine as claimed in claim 1, characterised in that, When the slit structure does not penetrate the tooth structure along the axial direction, the other end of the slit structure extends along the axial direction toward the yoke structure and does not exceed the bottom of the tooth groove, and the distance between the slit structure and the top of the tooth structure is L, where L≥2mm; And / or, the circumferential width of the slit structure is H, 0.2mm≤H≤0.5mm.

3. The stator structure for an axial flux permanent magnet motor of claim 1, wherein, When the slotted structure penetrates the toothed structure and the yoke structure along the axial direction, two adjacent first segmented iron cores are positioned together at the yoke structure by a positioning structure. Two adjacent first-section iron cores are spliced ​​together to form a splicing gap, the width of which is A, A≤0.2mm.

4. The stator structure for an axial flux permanent magnet electric machine according to claim 3, characterized in that, Each first segment core has a first mating structure on one side of the slotted structure located at the yoke structure, and a first concave-convex structure on the other side; during installation, the first mating structures of two adjacent first segment cores are inserted into the first concave-convex structure of another.

5. The stator structure for an axial flux permanent magnet motor of claim 3, wherein, Each first segment iron core has a recessed structure on both sides of the slotted structure located at the yoke structure. When two adjacent first segment iron cores are spliced ​​together, the recessed structures of the two adjacent first segment iron cores form a cylindrical space. A magnetically conductive metal component is installed in the cylindrical space, and both ends of the magnetically conductive metal component extend out of the cylindrical space to extend into the grooves inside and outside the housing of the axial flux permanent magnet motor, respectively. After the magnetically conductive metal component is installed, it is fixed with potting compound.

6. The stator structure for an axial flux permanent magnet motor of claim 3, wherein, Each first segment core comprises multiple silicon steel sheets formed by radially stacking.

7. The stator structure for an axial flux permanent magnet motor of claim 3, wherein, When the slotted structure does not penetrate the tooth structure along the axial direction, the slotted structure includes a first segment and a second segment. The first segment extends circumferentially from the bottom of the tooth groove towards the middle position of the tooth structure. The second segment is connected to the first segment and extends from the end of the first segment toward the bottom of the yoke structure. The second segment passes through the middle position of the tooth structure and extends axially downward at the yoke structure. The slotted structure divides the stator structure into multiple second-section iron cores, which are then spliced ​​together.

8. A stator structure for an axial flux permanent magnet electric machine as claimed in claim 7, characterised in that, Each second segment core has a second mating structure on one side of the second section and a second concave-convex structure on the other side. During installation, the second mating structures of two adjacent second segment cores are inserted into the second concave-convex structure of another. The joint between the second mating structure and the second concave-convex structure is located in a low magnetic density region.

9. A stator structure for an axial flux permanent magnet electric machine as claimed in claim 8, characterised in that, The axial thickness of the yoke structure of the second segmented core does not exceed the width of the tooth structure of the second segmented core; or, The second mating structure and the surface where the second concave-convex structure is located are arranged parallel to the axial direction.

10. The stator structure for an axial flux permanent magnet motor as claimed in claim 3, wherein, The slotted structure divides the stator structure into multiple second segmented iron cores, which are spliced ​​together. Each second segmented iron core includes the tooth structure and a transverse arm. The transverse arm is located at the bottom of the tooth structure. The transverse arm has a first side and a second side on both sides along the circumferential direction. The first side is located within the circumferential dimension of the tooth structure, and the second side is located outside the circumferential dimension of the tooth structure. The first side of the transverse arm of one of the second segment iron cores is in contact with the second side of the transverse arm of the other second segment iron core; The transverse arms of multiple second segment iron cores fit together to form the yoke structure of the stator structure, and tooth grooves are formed between the tooth structures of two adjacent second segment iron cores.

11. A stator structure for an axial flux permanent magnet electric machine as claimed in claim 10, wherein, The first side and the second side extend axially and are perpendicular to the top of the tooth structure.

12. The stator structure for an axial flux permanent magnet electric machine as claimed in claim 10, wherein, The second segmented iron core is composed of multiple silicon steel sheets stacked radially.

13. The stator structure for an axial flux permanent magnet motor of claim 10, wherein, The tooth groove width is the same in the radial direction.

14. The stator structure for an axial flux permanent magnet motor of claim 10, wherein, The first side is located below the circumferential central axis of the tooth structure.

15. The stator structure for an axial flux permanent magnet motor of claim 10, wherein, An insertion structure is provided between the first side and the second side, the insertion structure including a second mating structure provided on the first side and a second concave-convex structure provided on the second side; When two adjacent second-section iron cores are spliced ​​together, the second mating structure on the first side of one second-section iron core is inserted into the second concave-convex structure on the second side of the other second-section iron core; or, the second concave-convex structure on the second side of one second-section iron core is inserted into the second mating structure on the first side of the other second-section iron core and then spliced ​​together.

16. A stator structure for an axial flux permanent magnet electric machine as claimed in claim 15, characterised in that, The second mating structure is a concave portion, and the second concave-convex structure is a convex portion; or, the second mating structure is a convex portion, and the second concave-convex structure is a concave portion. The recess and the convex portion are provided to extend radially.

17. A stator structure for an axial flux permanent magnet electric machine as claimed in claim 16, characterised in that, One end of the recess is not fully penetrated radially and has a stop portion, while the other end is fully penetrated. When two adjacent second-section iron cores are spliced ​​together, the stop is set at the stop after the protrusion of one second-section iron core is inserted into the concave part of the other second-section iron core.

18. The stator structure for an axial flux permanent magnet motor of claim 10, wherein, When two adjacent second-section iron cores are spliced ​​together, a splicing gap is formed on the side of the transverse arm, and the width of the splicing gap is ≤0.2mm.

19. The stator structure for an axial flux permanent magnet motor of claim 10, wherein, In the outer ring of the stator structure, the second side portion of the transverse arm extends beyond the radial dimension of the tooth structure of the adjacent second segment core, while in the inner ring of the stator structure, the second side portion of the transverse arm is recessed within the radial dimension of the tooth structure of the adjacent second segment core.

20. An axial flux permanent magnet electric machine characterized by, Includes the stator structure for an axial flux permanent magnet motor as described in any one of claims 1 to 19.

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