A concentrated winding with end composite cooling structure, a motor, and its manufacturing method.

Abstract

A concentrated winding, a motor, and a manufacturing method with an end composite cooling structure are disclosed, belonging to the field of motor manufacturing technology. The concentrated winding includes multiple layers of sheet copper conductors, which are stacked along their thickness direction and electrically connected to form the concentrated winding. Each layer of sheet copper conductors includes an effective conductor segment located within the stator slot and an end conductor segment located outside the stator slot. The multiple end conductor segments are folded away from the stator slot in sequence from the outermost layer to the innermost layer, forming a layered end structure outside the slot. At least some end conductor segments have pre-formed bending areas, which are folded once or multiple times to form locally thickened areas. The outer periphery of the layered end structure is provided with an electrically insulating and thermally conductive potting compound to fill the gap between it and the motor housing, thus achieving both winding end resistance reduction and heat dissipation, suitable for engineering implementation and mass production.

Description

Technical Field

[0001] This invention relates to a concentrated winding with an end composite cooling structure, a motor, and a manufacturing method thereof, belonging to the field of motor manufacturing technology. Background Technology

[0002] As motors develop towards higher power density and higher integration, the problem of temperature rise at the winding ends is becoming increasingly prominent. The conductor paths at the winding ends are relatively long, the current density is concentrated, and the copper losses are relatively large. At the same time, there are often air gaps between the ends and the motor housing, resulting in poor heat dissipation conditions and the formation of local hot spots, which affects the motor's continuous output capability and insulation life.

[0003] To address end-contact temperature rise, various solutions have been proposed in existing technologies. One approach is to enhance end-contact heat dissipation, such as by incorporating air-cooling channels, oil-cooling nozzles, or thermally conductive potting materials. However, air cooling and oil cooling require additional cooling components, leading to structural complexity, increased costs, and limited space for small motors. While simple thermally conductive potting can improve heat conduction, it cannot reduce the heat generated by the end conductor itself.

[0004] Another approach is to use variable cross-section windings, reducing end resistance by increasing the cross-sectional area of ​​the end conductors. However, current implementations of variable cross-section windings largely rely on metal casting or metal 3D printing technologies. Casting processes are prone to defects such as sand holes and shrinkage cavities, and it is difficult to achieve thin-layer structures, which is not conducive to reducing high-frequency AC losses. Metal 3D printing, on the other hand, suffers from problems such as increased material resistivity, low forming efficiency, and high mass production costs, making it difficult to meet the needs of engineering and large-scale applications.

[0005] In addition, in existing concentrated windings, the ends of multi-layer sheet conductors are simply stacked and bent as a whole, with the ends of each layer tightly attached. This makes it difficult for the potting material to fully fill the areas between each layer and between the ends and the motor housing, further worsening the heat dissipation conditions.

[0006] Therefore, there is an urgent need to propose a centralized winding, motor, and manufacturing method with an end composite cooling structure, which can effectively reduce the end temperature rise without excessively increasing the manufacturing complexity and cost, while taking into account the requirements of winding end resistance reduction and heat dissipation, so as to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a concentrated winding for an electric motor, the motor itself, and a method for manufacturing the same, to solve the problems of high resistance loss, poor heat dissipation, and high local temperature rise in the end region of the winding in the prior art, as well as the complex and costly manufacturing process of existing variable cross-section windings. A brief overview of the invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0008] The technical solution of the present invention: Option 1: A concentrated winding with an end composite cooling structure, comprising multiple layers of sheet copper conductors, wherein the multiple layers of sheet copper conductors are stacked along the thickness direction and electrically connected to form a concentrated winding, wherein each layer of sheet copper conductors includes an effective conductor segment located in the stator slot and an end conductor segment located outside the stator slot; The end conductor segments of the multilayer sheet copper conductors are folded away from the stator slot in sequence from the outer layer to the inner layer, so that the end conductor segments of each layer form a layered and unfolded end structure outside the stator slot; The end conductor segment of the sheet copper conductor is provided with a pre-formed bending area. After the pre-formed bending area is folded or folded back once or multiple times, a local thickening area is formed. The thickness of the local thickening area is greater than the thickness of the corresponding effective conductor segment. The outer periphery of the layered unfolded end structure is provided with an electrically insulating and thermally conductive potting compound, which is used to fill the gap between the layered unfolded end structure and the motor housing after it is installed in the motor housing.

[0009] Preferably, the end conductor segments of the sheet-like copper conductors in adjacent layers are arranged at radial intervals and are folded and unfolded in layers.

[0010] Preferably, the thickness of the local thickening zone is 2, 3, or 4 times the thickness of the corresponding effective conductor segment.

[0011] Preferably, the electrically insulating and thermally conductive potting compound is an epoxy resin with added thermally conductive filler, wherein the thermally conductive filler includes one or more of alumina, boron nitride, aluminum nitride, magnesium oxide, and silicon carbide.

[0012] Option 2: A method for preparing a concentrated winding, comprising the following steps: S1. The sheet copper conductor is cut and shaped to form an effective conductor segment, an end conductor segment, and a pre-fabricated bending area; S2. Form an interlayer insulation layer or provide an interlayer insulation component on the surface of the sheet copper conductor; S3. Stack the multiple layers of the sheet copper conductors along the thickness direction and electrically connect them to form the winding body; S4. Assemble the winding body onto the stator core; S5. Fold the end conductor segments of the multilayer sheet copper conductors away from the stator slot in the order from the outer layer to the inner layer to form an end structure that unfolds radially in layers. S6. Fold or reverse at least part of the prefabricated bending area of ​​the end conductor segment once or multiple times to form a local thickening area; S7. Assemble the stator core and concentrated winding into the motor housing, and pot the layered end structure to fill the gap between the layered end structure and the motor housing with an electrically insulating and thermally conductive potting compound.

[0013] Preferably, in step S4, after the winding body is fitted onto the stator tooth module, the stator tooth module is axially assembled into the stator yoke via a dovetail groove structure.

[0014] Preferably, steps S5 and S6 are performed alternately: each end conductor segment with a local thickening zone is folded one by one in the order from the outer layer to the inner layer. After folding the current end conductor segment, its pre-made bending area is folded in half or folded back to form a local thickening zone, and then the operation is performed on the next end conductor segment.

[0015] Option 3: A motor with an end composite cooling structure includes a motor housing, a stator core, a rotor, and a concentrated winding. The concentrated winding is the same as described above. The stator core is fixedly disposed inside the motor housing, and the rotor is rotatably disposed inside the stator core, maintaining an air gap with the stator core. The concentrated winding is disposed on the stator core. The concentrated winding has a layered end structure, and the space between the layered end structure and the inner wall of the motor housing is filled with an electrically insulating and thermally conductive potting compound. The stator core is assembled from a stator yoke and several independently formed stator tooth modules. The root of the stator tooth module is fitted and connected to the inner sidewall of the stator yoke through a dovetail groove structure. The sidewalls of two adjacent stator tooth modules and the stator yoke together form a stator groove. The concentrated winding is fitted onto the outside of the stator tooth module and assembled together with the stator tooth module into the stator yoke.

[0016] Preferably, the electrically insulating and thermally conductive potting compound is used to limit the unfolding angle and potting layer thickness during the potting process by using an end positioning mold.

[0017] Preferably, the stator tooth modules are arranged at uniform intervals along the circumference, and there are multiple concentrated windings, which are respectively fitted onto each stator tooth module.

[0018] The present invention has the following beneficial effects: 1. This invention reduces end conductor losses. By providing a pre-formed bending zone in at least a portion of the end conductor segment and forming a locally thickened zone through one or more folds or reversals, the cross-sectional area of ​​the end conductor is increased, thereby reducing end resistance, copper loss, and heat generation while maintaining the original structure of the effective conductor segment; 2. This invention improves end heat dissipation conditions. By folding the end conductor segments of the multilayer sheet copper conductor sequentially from the outer layer to the inner layer away from the stator slot, a layered end structure is formed, shortening the heat conduction path between the end and the motor housing; combined with the electrically insulating and thermally conductive potting compound filled between the end structure and the motor housing, the ability of heat to be conducted from the end to the motor housing is improved, effectively reducing the temperature rise of the winding end; 3. This invention is conducive to engineering-scale mass manufacturing. It adopts a process of stacking sheet copper conductors and partially bending them, which eliminates the need for complex metal casting or 3D printing processes, avoiding casting defects, material performance degradation, and high costs, making it more suitable for engineering implementation and mass production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the fit between the concentrated winding and the motor housing of the present invention; Figure 2 This is a schematic diagram of the connection between the stator core and the concentrated winding; Figure 3 yes Figure 2 A sectional view of AA; Figure 4 This is a schematic diagram of the structure of a sheet-like copper conductor; Figure 5 This is a structural diagram of the motor housing; Figure 6 This is a flowchart of a method for preparing a concentrated winding.

[0020] In the figure: 10-Stator core, 11-Stator tooth module, 12-Stator yoke, 13-Dovetail groove structure, 20-Concentrated winding, 21-Sheet copper conductor, 22-Effective conductor segment, 23-End conductor segment, 24-Prefabricated bending area, 25-Interlayer electrical connection, 30-Motor housing, 31-Electrically insulating and thermally conductive potting compound. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0022] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections (i.e., non-detachable connections) include, but are not limited to, conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include, but are not limited to, conventional disassembly methods such as threaded connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can always be found to achieve the function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a hinged connection can be chosen for detachable connections.

[0023] Example 1: Combination Figures 1-5 This embodiment describes a concentrated winding 20 with an end composite cooling structure. The concentrated winding 20 includes multiple layers of sheet copper conductors 21, which are stacked along the thickness direction and electrically connected to form the concentrated winding 20. Each layer of the sheet copper conductors 21 includes an effective conductor segment 22 located within the stator slot and an end conductor segment 23 located outside the stator slot.

[0024] The sheet-shaped copper conductor 21 is formed into a predetermined contour by stamping, laser cutting, etching, or precision machining. In this embodiment, a precision stamping process is preferably used, and the material is oxygen-free copper strip with a thickness of 0.3 mm to 1.0 mm, so as to balance the utilization of the space in the groove and the strength of the end structure.

[0025] The end conductor segments 23 of the multilayer sheet copper conductors 21 are folded away from the stator slot in sequence from the outer layer to the inner layer, so that the end conductor segments 23 of each layer form a layered end structure outside the stator slot. Specifically, the end conductor segments 23 of adjacent layers of sheet copper conductors 21 are arranged radially at intervals and folded in layers. The folding angle can be set to 30° to 90° according to the shape of the inner wall of the motor housing 30, and the radial gap between adjacent layers is 0.5mm to 2mm. This structure facilitates the subsequent filling of the area between each layer and between the end and the motor housing 30 with the potting material.

[0026] The end conductor segment 23 of the sheet copper conductor 21 is provided with a pre-formed bending area 24, which forms a locally thickened area after being folded or bent back once or multiple times. The locally thickened area is located in the end conductor segment 23, and its thickness is greater than the thickness of the corresponding effective conductor segment 22.

[0027] Preferably, the thickness of the locally thickened area is 2, 3, or 4 times the thickness of the corresponding effective conductor segment 22. In this embodiment, a folding method is used to form a double thickness, which effectively reduces the end conductor resistance and copper loss without increasing the space occupied in the groove. The length of the pre-fabricated bending area accounts for 1 / 3 to 2 / 3 of the total length of the end conductor segment. After bending, it is shaped by a heating fixture at a heating temperature of 150℃ to 200℃ to reduce springback.

[0028] An interlayer insulation layer is provided between the adjacent sheet copper conductors 21. The interlayer insulation layer may be made of polyimide film, aramid paper, or coated insulating varnish. The adjacent sheet copper conductors 21 are electrically connected at a predetermined interlayer electrical connection portion 25 by partially removing the insulation layer and then welding or brazing, thereby forming a predetermined number of turns and a conduction path.

[0029] The outer periphery of the layered, unfolded end structure is provided with an electrically insulating and thermally conductive potting compound 31, which is used to fill the gap between the layered, unfolded end structure and the motor housing 30 after it is installed in the motor housing 30. The electrically insulating and thermally conductive potting compound 31 is epoxy resin with added thermally conductive filler, which includes one or more of alumina, boron nitride, aluminum nitride, magnesium oxide, and silicon carbide. The particle size of the thermally conductive filler is 0.5μm to 50μm, and the filling amount is 30% to 70% of the mass of the epoxy resin. After potting, the thermal conductivity can reach above 2.0W / (m·K). This potting compound not only ensures electrical insulation but also significantly improves the ability of the end structure to conduct heat to the motor housing 30.

[0030] Example 2: Combination Figures 1-6 This embodiment describes a method for preparing a concentrated winding, used to prepare the concentrated winding described in Example 1. The method includes the following steps: S1. The sheet copper conductor 21 is blanked and formed to create an effective conductor segment 22, an end conductor segment 23, and a pre-formed bending area 24. The blanking and forming method is selected according to the conductor material thickness and dimensional accuracy requirements, using processes such as stamping, laser cutting, etching, or precision machining. In this embodiment, precision stamping is preferred, punching out the contour in one go and removing burrs.

[0031] S2. Form an interlayer insulation layer or install an interlayer insulation component on the surface of the sheet copper conductor 21. This can be done by coating with insulating varnish or applying an insulating film. The insulating varnish, such as polyamide-imide, has a thickness of 0.02 mm to 0.05 mm. For parts requiring electrical connection, a peelable protective film is pre-applied.

[0032] S3. The multiple layers of sheet copper conductors 21 are stacked along the thickness direction and electrically connected to form the winding body. The number of stacked layers is determined according to the number of turns in the winding, usually 4 to 12 layers. At the predetermined electrical connection points, the insulation layer is removed by laser, and then adjacent conductor layers are connected together by welding or brazing.

[0033] S4. Assemble the winding body onto the stator core 10.

[0034] In this embodiment, the stator core 10 adopts a split structure, including a stator yoke 12 and several independently formed stator tooth modules 11. Specifically, after the winding body is fitted onto the stator tooth modules 11, the stator tooth modules 11 are axially assembled into the stator yoke 12 via dovetail groove structures 13. The dovetail groove fitting clearance is 0.01mm to 0.05mm, forming a stable connection after assembly. The split-type stator core structure facilitates assembly after the centralized winding prefabrication, improving assembly efficiency and reducing manufacturing difficulty.

[0035] S5. Fold the end conductor segments 23 of the multilayer sheet copper conductors 21 away from the stator slot in sequence from the outer layer to the inner layer to form a radially layered end structure. Use a special clamp during folding to control the folding angle of each layer to be consistent, such as 45°, and ensure that the end conductor segments of adjacent layers are spaced apart in the radial direction.

[0036] S6. The prefabricated bending area 24 of at least part of the end conductor segment 23 is folded or reversed once or multiple times to form a local thickening area.

[0037] Preferably, steps S5 and S6 are performed alternately: each end conductor segment 23 with a local thickening zone is folded one by one in order from the outer layer to the inner layer. After folding the current end conductor segment 23, its pre-formed bending area 24 is folded in half or folded back to form a local thickening zone, and then the next end conductor segment 23 is operated on. Using an alternating process helps reduce interlayer interference and improves the consistency of end forming. A heating fixture is used during folding to reduce springback.

[0038] S7. Assemble the stator core 10 and windings onto the motor housing 30, and pot the layered end structure to fill the gap between the layered end structure and the motor housing 30 with an electrically insulating and thermally conductive potting compound 31. Before potting, an end positioning mold is set to limit the unfolding angle of the end structure, the distance between the windings and the motor housing 30, and the thickness of the potting layer. The potting process includes a vacuum step, with a vacuum degree ≤100Pa, maintained for 10-15 minutes to reduce air bubbles and voids inside the potting compound and lower thermal resistance. After potting, heat to 80℃ and cure for 4 hours to obtain the finished product.

[0039] Example 3: Combination Figures 1-6 This embodiment describes a motor with an end composite cooling structure. The motor includes a motor housing 30, a stator core 10, a rotor, and a concentrated winding 20, which is the concentrated winding described in Embodiment 1.

[0040] The stator core 10 is fixedly installed inside the motor housing 30. The stator core 10 is assembled from a stator yoke 12 and several independently formed stator tooth modules 11.

[0041] Specifically, the root of the stator tooth module 11 is fitted and connected to the inner sidewall of the stator yoke 12 via a dovetail groove structure 13. The sidewalls of two adjacent stator tooth modules 11 and the stator yoke 12 together form a stator groove. The stator yoke 12 is annular, with multiple dovetail grooves evenly distributed circumferentially on its inner sidewall. The stator tooth module 11 is made of stacked silicon steel sheets with a stacking coefficient of 0.95 to 0.98, and its root is machined with a protrusion that mates with the dovetail groove. This split-joint structure facilitates the prefabrication and assembly of the concentrated winding 20.

[0042] The concentrated winding 20 is disposed on the stator core 10, specifically fitted onto the outside of the stator tooth module 11, and assembled together with the stator tooth module 11 into the stator yoke 12. The stator tooth modules 11 are evenly spaced circumferentially, with a quantity of 6, 9, or 12, and multiple concentrated windings 20 are respectively fitted onto each stator tooth module 11. The effective conductor segment 22 of the concentrated winding 20 is located within the stator slot, and the end conductor segment 23 is folded to form a layered end structure.

[0043] The rotor is rotatably mounted inside the stator core 10, maintaining an air gap with the stator core 10. Specifically, an air gap of 0.3mm to 1.0mm is maintained between the rotor and the inner wall of the stator tooth module 11. The rotor can adopt a permanent magnet embedded or surface-mount structure, and the rotor shaft is supported by bearings on the end cover of the motor housing 30.

[0044] The concentrated winding 20 has a layered, unfolded end structure, and an electrically insulating and thermally conductive potting compound 31 is filled between the layered, unfolded end structure and the inner wall of the motor housing 30. During the potting process, the unfolding angle and potting layer thickness of the electrically insulating and thermally conductive potting compound 31 are limited by an end positioning mold. The unfolding angle is, for example, 45°, and the potting layer thickness is, for example, 2mm to 3mm, ensuring that the potting compound is in close contact with the inner wall of the motor housing 30, forming an efficient heat conduction path. The potting material is epoxy resin with added thermally conductive filler, with a thermal conductivity ≥2.0W / (m·K) and a breakdown voltage ≥20kV / mm.

[0045] In this embodiment, during operation, the end conductors exhibit reduced resistance due to the locally thickened area, resulting in decreased self-heating. Simultaneously, the layered end structure, combined with a thermally conductive potting compound, rapidly conducts heat to the motor housing 30, significantly reducing the temperature rise at the winding ends. Testing shows that the end temperature rise under rated operating conditions is 25%–35% lower than that of traditional concentrated winding motors.

[0046] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A concentrated winding with an end composite cooling structure, characterized in that: It includes a multilayer sheet copper conductor (21), which is stacked along the thickness direction and electrically connected to form a concentrated winding (20). Each layer of the sheet copper conductor (21) includes an effective conductor section (22) located in the stator slot and an end conductor section (23) located outside the stator slot. The end conductor segments (23) of the multilayer sheet copper conductor (21) are folded away from the stator slot in the order from the outer layer to the inner layer, so that the end conductor segments (23) of each layer form a layered end structure outside the stator slot; The end conductor segment (23) of the sheet copper conductor (21) is provided with a pre-made bending area (24). The pre-made bending area (24) is formed into a local thickening area after being folded or folded back once or multiple times. The thickness of the local thickening area is greater than the thickness of the corresponding effective conductor segment (22). The outer periphery of the layered unfolded end structure is provided with an electrically insulating and thermally conductive potting compound (31) for filling the gap between the layered unfolded end structure and the motor housing (30) after it is installed in the motor housing (30).

2. A concentrated winding with an end composite cooling structure according to claim 1, characterized in that: The end conductor segments (23) of the adjacent layer of sheet copper conductors (21) are arranged radially at intervals and are folded and unfolded in layers.

3. A concentrated winding with an end composite cooling structure according to claim 1, characterized in that: The thickness of the local thickening zone is 2, 3 or 4 times the thickness of the corresponding effective conductor segment (22).

4. A concentrated winding with an end composite cooling structure according to claim 1, characterized in that: The electrically insulating and thermally conductive potting compound (31) is an epoxy resin with added thermally conductive filler, which includes one or more of alumina, boron nitride, aluminum nitride, magnesium oxide, and silicon carbide.

5. A method for preparing a concentrated winding, used to prepare the concentrated winding according to any one of claims 1-4, characterized in that, Includes the following steps: S1. The sheet copper conductor (21) is cut and shaped to form an effective conductor segment (22), an end conductor segment (23), and a prefabricated bending area (24). S2. Form an interlayer insulation layer or provide an interlayer insulation component on the surface of the sheet copper conductor (21); S3. Stack the multilayer sheet copper conductors (21) along the thickness direction and electrically connect them to form the winding body; S4. Assemble the winding body onto the stator core (10). S5. Fold the end conductor segments (23) of the multilayer sheet copper conductor (21) away from the stator slot in the order from the outer layer to the inner layer to form an end structure that unfolds in a radial layer. S6. The prefabricated bending area (24) of at least part of the end conductor segment (23) is folded or reversed once or multiple times to form a local thickening area; S7. Assemble the stator core (10) and the concentrated winding (20) onto the motor housing (30), and pot the layered end structure to form an electrically insulating and thermally conductive potting compound (31) that fills the gap between the layered end structure and the motor housing (30).

6. The method for preparing a concentrated winding according to claim 5, characterized in that: In step S4, after the winding body is fitted onto the stator tooth module (11), the stator tooth module (11) is axially assembled into the stator yoke (12) through the dovetail groove structure (13).

7. The method for preparing a concentrated winding according to claim 5, characterized in that: Steps S5 and S6 are performed alternately: each end conductor segment (23) with a local thickening area is folded one by one in the order from the outer layer to the inner layer. After folding the current end conductor segment (23), its prefabricated bending area (24) is folded or folded back to form a local thickening area, and then the operation is performed on the next end conductor segment (23).

8. A motor with an end composite cooling structure, characterized in that: The motor includes a motor housing (30), a stator core (10), a rotor, and a concentrated winding (20). The concentrated winding (20) is the concentrated winding as described in any one of claims 1 to 4. The stator core (10) is fixedly disposed inside the motor housing (30), and the rotor is rotatably disposed inside the stator core (10) and maintains an air gap with the stator core (10). The concentrated winding (20) is disposed on the stator core (10). The concentrated winding (20) has a layered end structure, and the space between the layered end structure and the inner wall of the motor housing (30) is filled with an electrically insulating and thermally conductive potting compound (31). The stator core (10) is assembled from a stator yoke (12) and several independently formed stator tooth modules (11). The root of the stator tooth module (11) is connected to the inner sidewall of the stator yoke (12) through a dovetail groove structure (13). The sidewalls of two adjacent stator tooth modules (11) together with the stator yoke (12) form a stator groove. The concentrated winding (20) is fitted on the outside of the stator tooth module (11) and is assembled together with the stator tooth module (11) into the stator yoke (12).

9. The motor according to claim 8, characterized in that: The electrically insulating and thermally conductive potting compound (31) has its unfolding angle and potting layer thickness limited by the end positioning mold during the potting process.

10. The motor according to claim 8, characterized in that: The stator tooth modules (11) are arranged at uniform intervals along the circumference, and the concentrated windings (20) are multiple, each corresponding to a stator tooth module (11).

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