Stator core and motor

Abstract

The utility model provides a stator core and a motor, and relates to the technical field of driving devices. The stator iron core comprises a plurality of punching sheet groups, the plurality of punching sheet groups are sequentially overlapped along the axial direction of the stator iron core, and each punching sheet group comprises a punching sheet body; the plurality of bulges are arranged on the periphery of the punching sheet body; the penetrating groove is formed in the bulge and penetrates through the punching sheet group along the axial direction of the punching sheet group; wherein the through groove of the punching sheet group is partially overlapped with the through groove of the adjacent punching sheet group, and at least part of the through groove of the punching sheet group is exposed out of the bulge of the adjacent punching sheet group so as to form a circumferential oil path. The technical problem that the oil path design on the outer surface of the stator iron core is not beneficial to the communication of the oil path in the circumferential direction due to the existence of the bulges on the outer circumferential surface is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of drive devices, in particular to a stator core and a motor. Background Art

[0002] The development of electric vehicle technology is driving ever-increasing demands on motor performance and efficiency. Improving motor heat dissipation is a key approach to improving motor performance and efficiency. Motor losses primarily include stator losses, rotor losses, and mechanical losses. These losses are the primary source of heat in the motor. High temperatures directly impact peak and sustained performance output and operational reliability. Compared to air and water, oil, with its greater thermal conductivity, provides more direct and efficient heat transfer to the primary heat generating areas. Therefore, to improve motor heat dissipation, oil cooling has gradually become the mainstream technology for drive motor cooling. Existing conventional motor oil cooling circuit designs, which utilize components such as end spray rings and slotted housings, increase costs due to the added parts and processing. However, specially designed stator core laminations are stamped, and then stacked or rotated to create a variety of oil circuit designs or combinations thereof. This simple process, significant cost advantages, and increased design flexibility have made stator core oil circuit design a new trend. However, the presence of protrusions on the outer peripheral surface of the stator core hinders the connectivity of the oil path in the circumferential direction (hereinafter referred to as the circumferential direction), which increases the number of oil inlets and the cost. Utility Model Content

[0003] In view of the above shortcomings of the prior art, the present invention provides a stator core to improve the oil circuit design on the outer surface of the stator core, which is not conducive to the technical problem of circumferential connectivity of the oil circuit due to the presence of protrusions on the outer peripheral surface.

[0004] To achieve the above-mentioned purpose and other related purposes, the present invention provides a stator core, comprising: a plurality of punching sheet groups, wherein the plurality of punching sheet groups are overlapped in sequence along the axial direction of the stator core, and the punching sheet groups include: a punching sheet body; a protrusion, wherein the plurality of protrusions are arranged on the outer periphery of the punching sheet body; and a through-groove, which is arranged at the protrusion and passes through the punching sheet group along the axial direction of the punching sheet group; wherein the through-groove of the punching sheet group partially overlaps with the through-groove of the adjacent punching sheet group, and the through-groove of the punching sheet group is at least partially exposed outside the protrusion of the adjacent punching sheet group to form a circumferential oil path.

[0005] In an exemplary embodiment of the present application, the protrusions on two adjacent punching sheet groups are staggered and stacked to form a stacking area and overhang areas respectively arranged on both sides of the stacking area, and the through grooves on the two protrusions are connected in the stacking area, and one part is located on the overhang area on one side of the stacking area, and the other part is located on the overhang area on the other side of the stacking area.

[0006] In an exemplary embodiment of the present application, projections of the stacking areas on adjacent punching sheet groups along the axial direction of the stator core overlap.

[0007] In an exemplary embodiment of the present application, a welding groove is provided on the outer peripheral surface of the protrusion, and the adjacent punching sheet groups are welded together, and the axial weld formed by the welding connection is located in the welding groove.

[0008] In an exemplary embodiment of the present application, the welding grooves on adjacent punching sheet groups overlap along the axial direction of the punching sheet group.

[0009] In an exemplary embodiment of the present application, the welding groove is located at the first position or the second position of the protrusion, the punching sheet group includes a plurality of line grooves, and the angle between the first position and the second position is an integer multiple of the angle between adjacent line grooves.

[0010] In an exemplary embodiment of the present application, the welding grooves on the same punching sheet group are arranged at the same position of the protrusions on the punching sheet group; the welding grooves on the adjacent stacked protrusions are respectively located at the first position and the second position.

[0011] In an exemplary embodiment of the present application, the through groove is an arc-shaped groove, and the axis of the arc-shaped groove coincides with the axis of the protrusion.

[0012] In an exemplary embodiment of the present application, the inner diameter of the through groove is equal to the inner diameter of the protrusion.

[0013] The present application also provides a motor, comprising a stator and a rotor, wherein the stator comprises the stator core described in any one of the above.

[0014] In combination with the existing technology, the beneficial effects of the present invention are:

[0015] Due to the presence of welds on existing stator cores, the oil circuit is not connected in the circumferential direction, thus requiring an increase in the number of oil inlets. The protrusions of the present application are provided with through-grooves that penetrate the protrusions axially along the lamination group. The through-grooves on a lamination group partially overlap with the through-grooves on adjacent lamination groups in the axial direction, and the through-grooves are at least partially exposed outside the protrusions of the adjacent lamination groups. As a result, the cooling medium can achieve circumferential oil circuit connectivity through the through-grooves between adjacent lamination groups, effectively reducing the number of oil inlets, lowering costs, and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of an exemplary stator core of the present application;

[0018] Figure 2 A top view of an exemplary punching sheet group of the present application;

[0019] Figure 3 A top view of another exemplary punching sheet group of the present application;

[0020] Figure 4 This is a schematic diagram of the outer periphery of the stator core of this application;

[0021] Figure 5 This is a schematic diagram of the oil circuit of an exemplary stator core after sectioning of the present application;

[0022] Figure 6 This is a schematic diagram of an exemplary welding groove in a raised first position of the present application;

[0023] Figure 7 This is a schematic diagram of an exemplary welding groove in the second raised position of the present application;

[0024] Figure 8 This is a schematic diagram of the overlap of through-grooves after stacking an exemplary punching sheet group of the present application.

[0025] Component number description

[0026] 10. Stator core; 100. Punching sheet group; 110. Punching sheet body; 120. Protrusion; 130. Through slot; 140. Wire slot; 150. First position; 160. Second position; 200. Welding slot. DETAILED DESCRIPTION

[0027] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation methods. The details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following examples and the features in the examples can be combined with each other unless there is a conflict. It should also be understood that the terms used in the examples of the present invention are for the purpose of describing specific implementation methods, not for the purpose of limiting the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0028] When numerical ranges are given in the examples, it should be understood that, unless otherwise specified herein, both endpoints of each numerical range and any value between the endpoints may be used. Unless otherwise defined, all technical and scientific terms used in this utility model are consistent with the prior art as understood by those skilled in the art and the description of this utility model. Any prior art methods, equipment, and materials similar or equivalent to those described in the examples of this utility model may also be used to implement this utility model.

[0029] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0030] Oil cooling is undoubtedly a highly competitive cooling method for new energy vehicle motors. However, the presence of protrusions on the outer surface of the stator core divides the oil circuit circumferentially, necessitating an increase in the number of oil inlets and increasing costs. To connect the circumferential oil circuit, existing solutions employ multi-segment welding. By staggering the protrusions and creating multiple weld seams, this creates space for the circumferential oil circuit to connect, but this approach increases process complexity and costs.

[0031] For this reason, see Figures 1 to 8, the present application proposes a stator core and an electric core to improve the situation where the existing oil circuit needs to increase the oil inlet or requires multiple sections of weld staggered, so as to reduce costs. Specifically, the stator core 10 includes a plurality of punching sheet groups 100, and the plurality of punching sheet groups 100 are overlapped in sequence along the axial direction of the stator core 10. The punching sheet group 100 is formed by stacking a plurality of stator punching sheets, and the punching sheet group 100 includes a punching sheet body 110, a protrusion 120 and a through slot 130. The punching sheet body 110 includes a yoke, a tooth portion and a wire slot 140. The yoke is an annular structure, which serves as a support and connector for other components; the tooth portion is arranged on the inner ring of the yoke and arranged in an array along the circumference of the yoke; wire slots 140 are formed between adjacent teeth, and the wire slots 140 are mainly used to carry and fix wires and windings. The plurality of protrusions 120 are arranged on the outer periphery of the punching sheet body 110, that is, the protrusions 120 are arranged on the yoke of the punching sheet body 110. The protrusion 120 has multiple functions, such as cooperating with the stator housing to position and support the stator core 10. Preferably, the protrusions 120 are arranged in a circumferential array along the circumference of the punch body 110 to provide uniform support, while also improving the uniformity of the oil circuit, so that the motor can dissipate heat evenly and stably. The through-groove 130 is provided at the protrusion 120 and passes through the punch group 100 along the axial direction of the punch group 100, that is, the through-groove 130 is conductive along the axial direction of the punch group 100. By providing the through-groove 130 passing through the protrusion 120, the oil circuit can pass through the protrusion 120, thereby allowing the cooling medium to pass through the protrusion 120, thereby solving the problem of the protrusion 120 blocking the oil circuit. In one embodiment, the through-groove 130 may be completely disposed within the protrusion 120, and the through-groove 130 does not penetrate the outer wall of the protrusion 120 in the radial direction of the lamination group 100, that is, the projection of the through-groove 130 in the axial direction of the lamination group 100 completely falls within the projection of the protrusion 120. In another embodiment, the through-groove 130 is partially disposed within the protrusion 120, and partially extends toward the lamination body 110 and into the lamination body 110, that is, the projection of the through-groove 130 in the axial direction of the lamination group 100 partially falls within the projection of the protrusion 120 in the axial direction of the lamination group 100, and the other portion falls within the projection of the lamination body 110 in the axial direction of the lamination group 100. The through-groove 130 of one lamination group 100 partially overlaps with the through-groove 130 of an adjacent lamination group 100, and the through-groove 130 of one lamination group 100 is at least partially exposed outside the protrusion 120 of the adjacent lamination group 100 to form a circumferential oil passage. When multiple punching sheet groups 100 with protrusions 120 are stacked in sequence, the through grooves 130 of the punching sheet group 100 partially overlap with the through grooves 130 of the adjacent punching sheet group 100, so that the cooling medium can flow between the through grooves 130. The through grooves 130 of the punching sheet group 100 are at least partially exposed outside the protrusions 120 of the adjacent punching sheet group 100, so that the cooling medium can flow from between the protrusions 120 into the through grooves 130, thereby forming a circumferential oil path. Figure 4 and Figure 5 The cooling medium between the protrusions 120 first enters the through-grooves 130 through the portion of the through-grooves 130 exposed outside the protrusions 120, flows within the through-grooves 130 to the area of ​​the through-grooves 130 covered by the protrusions 120, then enters the adjacent through-grooves 130 through the overlapping portion of the through-grooves 130, and then enters between the protrusions 120 through the portion of the adjacent through-grooves 130 exposed outside the protrusions 120, thereby forming a circumferential oil path for the cooling medium to pass through the protrusions 120. This reduces the number of oil inlets and eliminates the need for multiple welds in the stator core 10, effectively reducing process complexity and production costs.

[0032] See also Figure 1 In one embodiment, the protrusions 120 on two adjacent punching sheet groups 100 are staggered and stacked to form a stacking area and overhanging areas respectively arranged on both sides of the stacking area. The through grooves 130 on the two protrusions 120 are connected in the stacking area, and one portion is located on the overhanging area on one side of the stacking area, and the other portion is located on the overhanging area on the other side of the stacking area. The cooling medium flows into the through groove 130 from the area where the through groove 130 is located in the overhanging area, and then flows from the connection point of the through groove 130 in the stacking area to the other through groove 130, and then flows out of the through groove 130 from the area where the other through groove 130 is located in the overhanging area, thereby realizing the flow of the cooling medium from one side of the protrusion 120 to the other side of the protrusion 120, forming a circumferential oil path. The cooling medium includes but is not limited to insulating oil.

[0033] See also Figure 1, the stacking areas on the adjacent punching sheet groups 100 overlap along the axial projections of the stator core 10. In other words, the protrusions 120 of the adjacent punching sheet groups 100 are staggered in sequence, and the through slots 130 of the adjacent punching sheet groups 100 are staggered in sequence. The through slots 130 are consistent with the overlapping areas of the through slots 130 on both sides, so that the through slots 130 are connected in the axial direction, so that each through slot 130 only requires one overlapping area, which not only improves the fluidity of the cooling medium, but also reduces the area of ​​the overlapping area of ​​the through slots 130, thereby reducing the size of the through slots 130 and the protrusions 120 and avoiding the stator core 10 from being too large. Under the premise that the through slots 130 are of the same size, reducing the area of ​​the overlapping area of ​​the through slots 130 can increase the area of ​​the through slots 130 exposed outside the protrusions 120, thereby improving the fluidity of the cooling medium and ensuring the heat dissipation effect. The protrusions 120 of adjacent lamination groups 100 are staggered in sequence, which is also beneficial for ensuring the symmetry of the stator core 10, thereby facilitating the overall design of the motor. Of course, the protrusions 120 of adjacent lamination groups 100 can also be staggered in sequence, such as all lamination groups 100 are staggered clockwise relative to the lamination group 100 above them, or relative to the lamination group 100 below them; or some lamination groups 100 can be staggered clockwise relative to the lamination group 100 above them, and other parts of the lamination groups 100 can be staggered clockwise relative to the laminations below them. The selection can be made according to actual conditions.

[0034] In one embodiment, the protrusion 120 is an arc-shaped protrusion 120 , and the axis of the circle where the arc-shaped protrusion 120 is located coincides with the axis of the punching sheet assembly 100 .

[0035] In one embodiment, a plurality of identical protrusions 120 are provided on the outer circumference of the punching sheet group 100; in another embodiment, a plurality of protrusions 120 with different characteristics are provided on the outer circumference of the punching sheet group 100. The protrusions 120 with different characteristics can be arranged alternately or arranged in sequence, and can be matched and combined according to actual needs. This application does not limit this.

[0036] For example, the through-groove 130 may be a long strip groove, an arc-shaped groove, etc. Preferably, the through-groove 130 is an arc-shaped groove, and the axis of the circle where the arc-shaped groove is located coincides with the axis of the circle where the protrusion 120 is located. The arc-shaped groove can reduce the coverage of the through-groove 130 on the adjacent punching sheet group 100 by the protrusion 120, thereby improving the utilization rate of the through-groove 130. The arc-shaped groove also makes the outer wall thickness of the protrusion 120 uniform or substantially uniform, making it easier to select the welding position and reducing the difficulty of welding.

[0037] Furthermore, the inner diameter of the through-groove 130 is equal to the inner diameter of the protrusion 120, and the cooling medium flows in the groove between the protrusions 120, and then flows through the protrusion 120 via the through-groove 130 to the groove on the other side of the protrusion 120. If the inner diameter of the through-groove 130 is equal to the inner diameter of the protrusion 120, the inner diameter of the through-groove 130 is flush with the groove between the protrusions 120, and the cooling medium flows from the groove into the through-groove 130 more smoothly, reducing flow resistance. Under the condition that the through-groove 130 and the protrusion 120 have the same width, the through-groove 130 is close to the bottom of the protrusion 120, and the thickness of the edges of the through-groove 130 and the protrusion 120 is greater, thereby improving the strength of the protrusion 120 and reducing the possibility of the axial weld penetrating the protrusion 120.

[0038] See also Figures 1 to 3 In one embodiment, a welding groove 200 is provided on the outer peripheral surface of the protrusion 120, and the welding groove 200 is recessed into the protrusion 120. The adjacent punching sheet groups 100 are welded and connected. The axial weld formed by the welding connection is located in the welding groove 200, and the protruding axial weld is in the welding groove 200 and does not exceed the welding groove 200, so as to facilitate the matching of the protrusion 120 with the stator shell or casing.

[0039] Furthermore, the welding grooves 200 on the adjacent punching sheet groups 100 overlap along the axial direction of the punching sheet group 100, that is, the welding grooves 200 on the punching sheet group 100 overlap with the welding grooves 200 on the adjacent punching sheet groups 100 on both sides in the axial direction of the punching sheet group 100, and the welding grooves 200 pass through the stator core 10 along the axial direction of the punching sheet group 100, so that the axial weld passes through the stator core 10 along the axial direction of the stator core 10. Compared with the existing multi-segment staggered welding, the entire axial weld reduces the difficulty of the welding process, improves the welding efficiency, and reduces the cost.

[0040] See also Figure 2 、 Figure 3 、 Figures 6 to 8 In one embodiment, the protrusion 120 has a first position 150 and a second position 160, and the welding groove 200 is set at the first position 150 or the second position 160. The welding groove 200 on the punching sheet group 100 and the welding groove 200 on the adjacent punching sheet group 100 are respectively arranged at the first position 150 and the second position 160, so that when the protrusions 120 of adjacent punching sheet groups 100 are staggered, the welding grooves 200 of adjacent punching sheet groups 100 overlap in the axial direction of the punching sheet group 100, reducing the number of welding grooves 200, facilitating the welding connection of the punching sheet group 100, and improving welding efficiency.

[0041] See also Figures 1 to 3In one embodiment, the punching sheet group 100 includes a plurality of wire slots 140, and the angle between the first position 150 and the second position 160 is an integer multiple of the angle between adjacent wire slots 140, ensuring that when the welding grooves 200 are aligned, the wire slots 140 of adjacent punching sheet groups 100 are also in an aligned state, which facilitates the stacking of the punching sheet groups 100 and facilitates the welding of the stator core 10.

[0042] See also Figure 2 and Figure 3 In one embodiment, the welding grooves 200 on the same punching sheet group 100 are arranged at the same position of the protrusions 120 on the punching sheet group 100. For example, the welding grooves 200 on one punching sheet group 100 are all located at the first position 150 of the protrusions 120 on the punching sheet group 100, and the welding grooves 200 on adjacent punching sheet groups 100 are all located at the second position 160 of the protrusions 120 on the punching sheet group 100. This makes it easier to align adjacent punching sheet groups 100 when the punching sheet groups 100 are staggered and stacked. Preferably, the protrusions 120 are arranged in a circular array on the punching sheet body 110, and the welding grooves 200 are located at the same position of the protrusions 120 on one punching sheet group 100. When the punching sheet group 100 is rotated by the angle between adjacent protrusions 120 on the same punching sheet group 100, the punching sheet groups 100 and adjacent punching sheet groups 100 can still be aligned, facilitating stacking of the punching sheet groups 100.

[0043] See also Figure 1 In one embodiment, the number of the welding grooves 200 corresponds to the number of the protrusions 120, that is, each welding groove 200 has a corresponding through-groove 130 at its bottom, so that a circumferential oil path passes through the protrusions 120 and the welding grooves 200 through the through-groove 130. Of course, the number of protrusions 120 can be set to be greater than the number of welding grooves 200, or the number of welding grooves 200 can be greater than the number of protrusions 120, and the setting can be made as needed.

[0044] Of course, in some other embodiments, the through slot 130 can also be used to realize an oil circuit that is not limited to crossing the protrusion 120 or the weld, and can also be used to cross other structural features on the outer circumferential surface of the stator core 10, such as an oil circuit that can be used to cross the key of the stator core 10.

[0045] It's understood that this oil circuit design can be combined with end punch oil holes to create centripetal oil cooling, spraying the end windings. The end punch oil holes can connect to either the outer oil cavity of protrusion 120 or the semi-open or closed grooves of protrusion 120. Of course, this oil circuit design can also leverage centripetal oil cooling, achieving circumferential oil circuit connection while also combining an axially oriented oil circuit to cool the gears.

[0046] It can also be understood that a protrusion 120 feature having a through-groove 130 feature is provided, and the shape of the protrusion 120 profile and its groove profile includes but is not limited to that described in the embodiment; the type, quantity, and position of the protrusion 120 features that can be matched on each piece are not limited and can be set as needed; the number of punching sheet groups 100 included in the stator core 10 and the number of stator punching sheets included in the punching sheet group 100 are not limited and can be selected as needed; the rotation angle between adjacent punching sheet groups 100 is not limited and can be set as needed.

[0047] The present application also provides a motor comprising a stator and a rotor, wherein the stator is annularly disposed on the outer circumference of the rotor and is coaxially arranged with the rotor. The stator comprises a stator core 10 as described in the above embodiment. It should be noted that the structure of the stator core 10 is similar to or identical to that of the stator core 10 described in the above embodiment, and to avoid repetition, a detailed description thereof will not be given here.

[0048] The present invention provides a stator core and a motor. A protrusion 120 having a through-slot 130 is provided on a stator lamination. After a stator lamination group 100 is stacked to form the lamination group 100, the protrusions 120 on adjacent lamination groups 100 are staggered so that adjacent through-slots 130 partially overlap and are partially exposed outside the protrusions 120. Cooling medium flows from the through-slot 130 region exposed outside the protrusions 120, through the through-slot 130 region covered by the protrusions 120, and then through the overlapping through-slot 130 region. Cooling medium then enters the through-slot 130 of one lamination group 100, enters the through-slot 130 of the adjacent lamination group 100, and flows through the through-slot 130 of the adjacent lamination group 100 to between the protrusions 120, thereby forming a circumferential oil path. This reduces the number of oil inlets, lowering process difficulty and cost.

[0049] Therefore, the present invention effectively overcomes some practical problems in the prior art and thus has high utility value and practical significance. The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by persons of ordinary skill in the art without departing from the spirit and technical concepts disclosed in the present invention shall be covered by the claims of the present invention.

Claims

1. A stator core, characterized in that: include: A plurality of punching sheet groups, wherein the plurality of punching sheet groups are overlapped in sequence along the axial direction of the stator core, and the punching sheet groups include: Film processing body; protrusions, a plurality of said protrusions being arranged on the outer periphery of said punching sheet body; a through groove, provided at the protrusion and penetrating the punching sheet group along the axial direction of the punching sheet group; The through grooves of the punching sheet group partially overlap with the through grooves of the adjacent punching sheet group, and the through grooves of the punching sheet group are at least partially exposed outside the protrusions of the adjacent punching sheet group to form a circumferential oil path.

2. The stator core according to claim 1, characterized in that The protrusions on two adjacent punching sheet groups are staggered and stacked to form a stacking area and overhanging areas respectively arranged on both sides of the stacking area. The through grooves on the two protrusions are connected in the stacking area, and one part is located on the overhanging area on one side of the stacking area, and the other part is located on the overhanging area on the other side of the stacking area.

3. The stator core according to claim 2, characterized in that The stacking areas on adjacent punching sheet groups overlap in projection along the axial direction of the stator core.

4. The stator core according to claim 1, wherein: A welding groove is provided on the outer peripheral surface of the protrusion, and the adjacent punching sheet groups are welded together, and the axial weld formed by the welding connection is located in the welding groove.

5. The stator core according to claim 4, characterized in that The welding grooves on adjacent punching sheet groups overlap along the axial direction of the punching sheet group.

6. The stator core according to claim 4, characterized in that The welding groove is located at the first position or the second position of the protrusion, the punching sheet group includes a plurality of line grooves, and the angle between the first position and the second position is an integer multiple of the angle between adjacent line grooves.

7. The stator core according to claim 6, characterized in that The welding grooves on the same punching sheet group are arranged at the same position of the protrusions on the punching sheet group; the welding grooves on the adjacent stacked protrusions are respectively located at the first position and the second position.

8. The stator core according to claim 1, characterized in that The through groove is an arc-shaped groove, and the axis of the arc-shaped groove coincides with the axis of the protrusion.

9. The stator core according to claim 8, characterized in that The inner diameter of the through groove is equal to the inner diameter of the protrusion.

10. A motor comprising a stator and a rotor, characterized in that: The stator includes the stator core according to any one of claims 1 to 9.

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