Stator core, stator assembly and permanent magnet motor
By designing a stator core formed by stacking offset, closed and positive punching sheets in the permanent magnet motor, the vibration and noise problems caused by the permanent magnet motor's slot torque are solved, the motor's output peak torque is maintained, and the motor's operating stability and driving comfort are improved.
Patent Information
- Application Number
- CN202422653361.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2034-10-31
AI Technical Summary
In the existing technology, when the winding of a permanent magnet motor is not energized, the interaction force between the permanent magnet and the stator core causes cogging torque, which affects the vibration and noise of the motor, and further affects the torque control accuracy and driving comfort. Although the rotor pole skew method can reduce the cogging torque, it will cause the output peak torque to decrease.
By adopting offset core segments formed by stacking offset punching sheets and closed core segments formed by stacking closed punching sheets, the axis offset angle between the slot opening and the open stator slot is reasonably set, and the positive core segments are formed by combining the positive punching sheets to form the stator core, the cogging torque is reduced without affecting the peak torque.
Under the condition of rotor straight pole, the cogging torque is effectively reduced, the peak torque output capacity is avoided from decreasing, and the operating stability and comfort of the motor are improved.
Smart Images
Figure CN223402283U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of motors, and in particular to a stator core, a stator assembly, and a permanent magnet motor. Background Art
[0002] The drive motor is a key component of the powertrain of new energy vehicles and is typically a permanent magnet motor. When the windings are deenergized, the interaction between the permanent magnets and the stator core of the permanent magnet motor generates cogging torque, which causes vibration and noise in the motor, affecting its performance. For example, it affects the motor's torque control accuracy and operating smoothness, which in turn affects the vehicle's ride comfort. In the prior art, rotor skewing is commonly used to reduce cogging torque in order to improve the NVH (Non-Volatile, Harsh) performance of permanent magnet motors under specific operating conditions and enhance driving comfort. However, rotor skewing reduces the output peak torque; therefore, methods for improving cogging torque require further refinement. Utility Model Content
[0003] Based on this, the present application provides a stator core, a stator assembly and a permanent magnet motor to improve the problem in the prior art of using rotor skew poles to improve the slot torque but affecting the peak torque output by the motor.
[0004] In a first aspect, the present application provides a stator core, comprising m pairs of offset core segments, where m is a positive integer not less than 1; the offset core segments are formed by stacking offset punches, the offset punches are provided with open stator slots, and the open stator slots are provided with notches on the side close to the inner side of the offset punches, and the open stator slots and the notches are both axially symmetrical structures; in the same pair of offset core segments, the axes of the notches of all the offset punches on one offset core segment are positively offset by n*θ from the axes of the open stator slots, and the axes of the notches of all the offset punches on the other offset core segment are negatively offset by n*θ from the axes of the open stator slots, where n is a positive integer not less than 1; the stator core also comprises a closed core segment, which is formed by stacking closed punches, the closed core segment is provided with closed stator slots, and the closed stator slots are not provided with notches.
[0005] In one embodiment, a plurality of open slot teeth are provided on the inner side of the offset punching sheet, and adjacent two of the open slot teeth on the offset punching sheet are spaced apart to enclose the open stator slot; a first tooth portion and a second tooth portion are respectively provided on the side where two adjacent open slot teeth are close to each other, and the first tooth portion and the second tooth portion are spaced apart to form the slot; on the offset punching sheet where the axis of the slot is positively offset by n*θ from the axis of the open stator slot, the length of the first tooth portion is greater than the length of the second tooth portion; on the offset punching sheet where the axis of the slot is negatively offset by n*θ from the axis of the open stator slot, the length of the first tooth portion is less than the length of the second tooth portion.
[0006] In one embodiment, a plurality of closed slot teeth are provided on the inner side of the closed punching sheet, and two adjacent closed slot teeth on the closed punching sheet are connected and hollowed out in the middle to enclose and form the closed stator slot.
[0007] In one embodiment, the stator core further includes an upright core segment, which is formed by stacking upright punching sheets. The upright punching sheets are provided with open stator slots and slot openings, and the axes of the open stator slots of all the upright punching sheets on the upright core segment coincide with the axes of the slot openings.
[0008] In one embodiment, a plurality of open slot teeth are provided on the inner side of the upright punching sheet, and adjacent two of the open slot teeth on the upright punching sheet are spaced apart to enclose and form the open stator slot; a first tooth portion and a second tooth portion are respectively provided on the side where two adjacent open slot teeth are close to each other, and the first tooth portion and the second tooth portion are spaced apart to form the slot; the length of the first tooth portion on the upright punching sheet is equal to the length of the second tooth portion.
[0009] In one embodiment, the offset punch, the closed punch, and the upright punch are all made of silicon steel sheets.
[0010] In one embodiment, m pairs of the offset core segments are axially superimposed on both sides of the closed core segment and are symmetrically arranged along the axial direction of the closed core segment.
[0011] In one embodiment, the open stator slots are aligned with outer edges of the closed stator slots.
[0012] In a second aspect, the present application provides a stator assembly, which includes any stator core provided in the present application.
[0013] In a third aspect, the present application provides a permanent magnet motor, which includes any stator assembly provided in the present application.
[0014] The present application reduces the cogging torque under the condition of straight rotor poles by stacking closed core segments formed by stacking closed punching sheets with m pairs of offset core segments formed by stacking offset punching sheets, and at the same time reasonably sets the offset angle between the axis of the slot of the offset punching sheet and the axis of the open stator slot in the m pairs of offset core segments, so as to avoid a decrease in the output capacity of the peak torque. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 A schematic structural diagram of the stator core provided in Example 1 of the present application;
[0016] Figure 2 A schematic structural diagram of the offset punching sheets of the stator core provided in Example 1 of the present application;
[0017] Figure 3 A schematic structural diagram of another offset punching sheet of the stator core provided in Example 1 of the present application;
[0018] Figure 4 A schematic structural diagram of a closed punching sheet of a stator core provided in Example 1 of the present application;
[0019] Figure 5 A schematic structural diagram of another stator core provided in Example 1 of the present application;
[0020] Figure 6 This is a schematic structural diagram of the upright punching sheets of the stator core provided in Example 1 of the present application.
[0021] Figure numerals: 100, offset core segment; 110, offset punching sheet; 200, open stator slot; 210, slot; 300, closed core segment; 310, closed punching sheet; 400, closed stator slot; 500, open slot tooth; 510, first tooth portion; 520, second tooth portion; 600, closed slot tooth; 700, upright core segment; 710, upright punching sheet. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0023] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention.
[0024] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not intended to limit the conditions under which the present invention can be implemented. Any structural modifications, changes in proportions, or adjustments in sizes should still fall within the scope of the technical contents disclosed in this utility model without affecting the effects and purposes that can be achieved by the present utility model.
[0025] Terms such as "upper," "lower," "left," "right," "center," "longitudinal," "transverse," "horizontal," "inner," "outer," "radial," and "circumferential" used in this specification to indicate positions or locations are based on those shown in the accompanying drawings and are intended solely for ease of description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] Example 1
[0027] The first embodiment of the present application provides a stator core, such as Figures 1 to 6 As shown, the stator core includes m pairs of offset core segments 100, where m is a positive integer not less than 1; the offset core segments 100 are formed by stacking offset punches 110, and the offset punches 110 are provided with open stator slots 200. The open stator slots 200 are provided with notches 210 on one side close to the inner side of the offset punches 110, and both the open stator slots 200 and the notches 210 are axisymmetric structures; in the same pair of offset core segments 100, the notches 210 of all the offset punches 110 on one offset core segment 100 are symmetrical. The axis of the stator core segment 100 and the axis of the open stator slot 200 are both positively offset by n*θ, and the axes of the slots 210 of all the offset punching sheets 110 on the other offset core segment 100 and the axis of the open stator slot 200 are both negatively offset by n*θ, where n is a positive integer not less than 1; the stator core also includes a closed core segment 300, which is formed by stacking closed punching sheets 310, and the closed stator slots 400 are provided on the closed core segment 300, and the closed stator slots 400 are not provided with slots 210.
[0028] like Figure 1 As shown, in this embodiment, the stator core can be formed by stacking punching sheets, and the punching sheets can be arranged in different forms according to actual needs. When punching sheets of the same form are stacked axially, they form a core segment; punching sheets of different forms form different core segments. The stator core can be considered to be composed of several core segments of different forms stacked axially.
[0029] like Figures 1 to 3As shown, in this embodiment, the stator core includes m pairs of offset core segments 100, where m is a positive integer not less than 1; that is, this embodiment includes at least one pair of offset core segments 100. The offset core segments 100 can be formed by stacking offset punchings 110, and each offset punching 110 is provided with a plurality of open stator slots 200; the plurality of open stator slots 200 can be provided on the inner side of the offset punching 110 and arranged at equal intervals along the circumferential direction. At the same time, the offset punching 110 is also provided with a notch 210 on the inner side of the open stator slot 200, so that the open stator slot 200 is "open". The open stator slot 200 and its notch 210 are both axially symmetrical structures, and their symmetry axes can both be radial extensions of the stator core. The offset punches 110 in the same pair of offset core segments 100 have two forms, one of which is that the axis of the slot 210 is positively offset from the axis of the open stator slot 200, and the other is that the axis of the slot 210 is negatively offset from the axis of the open stator slot 200. The angles of the positive offset and the negative offset in the two forms are the same, that is, both are n*θ, where n is a positive integer not less than 1.
[0030] It should be noted that when m = 1, it has only one pair of offset core segments 100; and n can be equal to 1, or of course, 2 or 3, etc. In this pair of offset core segments 100, the two types of offset punches 110 are respectively positively offset by θ and negatively offset by θ. When m = 2, it has two pairs of offset core segments 100; and n should have two values to correspond to the two pairs of offset core segments 100, for example, n can be 1 and 2; in the two pairs of offset core segments 100, the two types of offset punches 110 of one pair of offset core segments 100 can be respectively positively offset by θ and negatively offset by θ, while the two types of offset punches 110 of the other pair of offset core segments 100 can be respectively positively offset by 2θ and negatively offset by 2θ. Of course, when m = 2, n can also be the other two values.
[0031] like Figure 1 and Figure 4 As shown, in this embodiment, the stator core also includes a closed core segment 300. The position and order of the closed core segment 300 and the aforementioned m pairs of offset core segments 100 when axially stacked can be appropriately combined according to actual needs and are not limited here. The closed punching 310 is provided with a plurality of closed stator slots 400, and the closed stator slots 400 are not provided with slots 210 to achieve a "closed" configuration. When the closed core segment 300 and the offset core segment 100 are axially stacked, the open stator slots 200 are connected to the closed stator slots 400.
[0032] The stator core is suitable for use in a stator assembly, which can also include a stator winding. The stator winding can be formed by winding coils. In this embodiment, the coils can be inserted from the ends of the stator core into the open stator slots 200 and the closed stator slots 400 to achieve the purpose of winding the stator winding on the stator core. The coils can be made of round copper wire or flat copper wire. When using flat copper wire, the stator winding has a relatively high slot fill factor within the stator slots, thereby increasing the power of the motor.
[0033] It can be understood that the present application reduces the cogging torque under the condition of straight pole of the rotor by stacking the closed core segment 300 formed by stacking the closed punching sheets 310 with the offset core segment 100 formed by stacking m pairs of offset punching sheets 110, and at the same time reasonably sets the offset angle between the axis of the slot 210 of the offset punching sheet 110 and the axis of the open stator slot 200 in the m pairs of offset core segments 100, so as to avoid a decrease in the output capacity of the peak torque.
[0034] Specifically, a plurality of open slot teeth 500 are provided on the inner side of the offset punching sheet 110, and adjacent two open slot teeth 500 on the offset punching sheet 110 are spaced apart to enclose and form an open stator slot 200; a first tooth portion 510 and a second tooth portion 520 are respectively provided on the side where the two adjacent open slot teeth 500 are close to each other, and the first tooth portion 510 and the second tooth portion 520 are spaced apart to form a slot 210; on the offset punching sheet 110 where the axis of the slot 210 is positively offset by n*θ from the axis of the open stator slot 200, the length of the first tooth portion 510 is greater than the length of the second tooth portion 520; on the offset punching sheet 110 where the axis of the slot 210 is negatively offset by n*θ from the axis of the open stator slot 200, the length of the first tooth portion 510 is less than the length of the second tooth portion 520.
[0035] like Figure 2 and Figure 3 As shown, in this embodiment, for example, the punching sheet can be prepared and formed by blanking, and when the offset punching sheet 110 is blanked, a plurality of open slot teeth 500 can be integrally formed on its inner side, and the plurality of open slot teeth 500 can be arranged at equal intervals along the circumferential direction. Along the radial direction of the stator core, the outer sides of the plurality of open slot teeth 500 can be connected by a circular ring structure; at this time, two adjacent open slot teeth 500 can enclose an open stator slot 200. A first tooth portion 510 and a second tooth portion 520 can be arranged between the inner sides of the plurality of open slot teeth 500, and the first tooth portion 510 and the second tooth portion 520 can enclose a notch 210. In other words, the two sides of any open slot tooth 500 can be provided with a first tooth portion 510 and a second tooth portion 520, respectively.
[0036] like Figure 2 and Figure 3As shown, in this embodiment, the lengths of the first tooth portion 510 and the second tooth portion 520 determine the offset form of the offset punch 110. The first tooth portion 510 can be defined as the tooth portion of the open slot tooth 500 to the left in the counterclockwise direction; and correspondingly, the second tooth portion 520 is the tooth portion of the open slot to the right in the counterclockwise direction. When the length of the first tooth portion 510 is greater than the length of the second tooth portion 520, the axis of the slot 210 is located to the right of the axis of the open stator slot 200 in the counterclockwise direction, which can be defined as a positive offset; and correspondingly, when the length of the first tooth portion 510 is less than the length of the second tooth portion 520, the axis of the slot 210 is located to the left of the axis of the open stator slot 200 in the counterclockwise direction, which can be defined as a negative offset.
[0037] It can be understood that this embodiment facilitates the preparation of two offset forms of open stator slots 200 and slot openings 210 on the offset punching sheet 110 by reasonably setting the shapes of the open slot teeth 500 and the first tooth portion 510 and the second tooth portion 520 on the offset punching sheet 110, so as to facilitate the further preparation of the required paired offset core segments 100.
[0038] like Figure 4 As shown, specifically, a plurality of closed slot teeth 600 are provided on the inner side of the closed punching sheet 310 , and two adjacent closed slot teeth 600 on the closed punching sheet 310 are connected and hollowed out in the middle to enclose and form a closed stator slot 400 .
[0039] In this embodiment, for example, the closed punching sheet 310 can also be prepared by blanking. During blanking, a plurality of closed slot teeth 600 are formed on its inner side. The plurality of closed slot teeth 600 can also be connected along the radial outer side of the stator core by a circular ring structure, and can also be connected along the inner side of the stator core in a similar manner, so as to be continuously arranged to achieve a "closed" arrangement of the closed stator slots 400. In other words, a hollow is formed between two adjacent closed slot teeth 600 on the closed punching sheet 310, and this hollow is the closed stator slot 400.
[0040] It is understandable that this embodiment facilitates the preparation of closed stator slots 400 on the closed punching sheet 310 by reasonably setting the shape of the closed slot teeth 600 on the closed punching sheet 310, so as to further prepare the required pairs of closed core segments 300.
[0041] Specifically, the stator core also includes an upright core segment 700, which is formed by stacking upright punchings 710. The upright punchings 710 are provided with open stator slots 200 and slots 210. The axes of the open stator slots 200 of all the upright punchings 710 on the upright core segment 700 coincide with the axes of the slots 210.
[0042] like Figure 5 and Figure 6 As shown, in this embodiment, for example, the stator core can also include an upright core segment 700, and the upright core segment 700 can be formed by stacking upright punches 710. The upright punches 710 can also be provided with open stator slots 200 and slots 210, and in the upright punches 710, the axis of the open stator slots 200 coincides with the axis of the slots 210; that is, the axis of the open stator slots 200 of the upright punches 710 is not offset from the axis of the slots 210. The upright core segment 700 is also axially stacked with the closed core segment 300 and the m pairs of offset core segments 100, and their positions and order when stacked can also be appropriately combined according to actual needs, and are also not limited.
[0043] It is understandable that this embodiment can also reduce the cogging torque under the condition of rotor straight pole by cooperating with the normal core segment 700, the closed core segment 300 and the m pairs of offset core segments 100, thereby ensuring the output capacity of the peak torque.
[0044] More specifically, a plurality of open slot teeth 500 are provided on the inner side of the upright punching sheet 710, and adjacent two open slot teeth 500 on the upright punching sheet 710 are spaced apart to enclose and form an open stator slot 200; a first tooth portion 510 and a second tooth portion 520 are respectively provided on the side where the two adjacent open slot teeth 500 are close to each other, and the first tooth portion 510 and the second tooth portion 520 are spaced apart to form a slot opening 210; the length of the first tooth portion 510 on the upright punching sheet 710 is equal to the length of the second tooth portion 520.
[0045] like Figure 6 As shown, in this embodiment, for example, the open stator slots 200 and the slot openings 210 can be formed on the positive punching sheet 710 in the same manner as on the offset punching sheet 110. The difference is that on the positive punching sheet 710, the lengths of the first tooth portion 510 and the second tooth portion 520 are no longer one longer than the other, but are adjusted so that the length of the first tooth portion 510 is equal to the length of the second tooth portion 520.
[0046] It can be understood that this embodiment facilitates the preparation of non-biased open stator slots 200 and slot openings 210 on the upright punching sheet 710 by reasonably setting the shapes of the open slot teeth 500 and the first tooth portion 510 and the second tooth portion 520 on the upright punching sheet 710, so as to facilitate the further preparation of the required paired upright core segments 700.
[0047] More specifically, the offset punching sheet 110 , the closed punching sheet 310 and the upright punching sheet 710 are all made of silicon steel sheets.
[0048] In this embodiment, for example, the offset punch 110, the closed punch 310, and the upright punch 710 can all be supported by silicon steel sheets. Silicon steel sheets have good magnetic conductivity and can effectively increase the magnetic field strength of the motor, thereby improving the output power and efficiency of the motor. At the same time, the iron loss of the silicon steel sheet is low, that is, the heat generated in the magnetic field is less, which helps to reduce the temperature rise of the motor and extend the service life of the motor. Furthermore, the good mechanical properties of the silicon steel sheet, such as toughness, elasticity, and wear resistance, enable it to maintain stable operation at high speeds while withstanding certain impacts and vibrations.
[0049] Specifically, m pairs of offset core segments 100 are axially superimposed on both sides of the closed core segment 300 and are symmetrically arranged along the axial direction of the closed core segment 300 .
[0050] like Figure 1 As shown, in this embodiment, it is exemplified that when the closed core segment 300 and m pairs of offset core segments 100 are superimposed, they can be arranged symmetrically along the axial direction, that is, the axial lengths of the two offset core segments 100 arranged in pairs can be set to be equal, and the two offset core segments 100 can be distributed on both sides of the closed core segment 300, and the spacing between the two offset core segments 100 and the closed core segment 300 can be equal.
[0051] It can be understood that when the closed core segments 300 and the m pairs of offset core segments 100 are axially symmetrically arranged, the effect of reducing the cogging torque is better.
[0052] Specifically, the outer edges of the open stator slots 200 and the closed stator slots 400 are aligned.
[0053] like Figures 2 to 4 As shown, in this embodiment, for example, the open stator slots 200 on the offset punching sheet 110 and the closed stator slots 400 on the closed punching sheet 310 can be configured to have the same shape and size. When the offset core and the closed core segment 300 are stacked, the outer edges of the open stator slots 200 and the closed stator slots 400 can be aligned.
[0054] It can be understood that, in this embodiment, by aligning the outer edges of the open stator slots 200 and the closed stator slots 400 , the coils are easily inserted into the stator slots, and are not easily obstructed during the insertion process.
[0055] The implementation principle of a stator core provided in the first embodiment of the present application is as follows:
[0056] The offset punches 110, closed punches 310, and upright punches 710 are punched and formed separately; then, the aforementioned punches are stacked in the desired order, with the offset punches 110 stacked to form an offset core segment 100, and the offset core segments 100 are arranged in pairs. In the same pair of offset core segments 100, the axes of the notches 210 of all offset punches 110 on one offset core segment 100 are positively offset from the axes of the open stator slots 200, while the axes of the notches 210 of all offset punches 110 on the other offset core segment 100 are negatively offset from the axes of the open stator slots 200. The closed punches 310 are stacked to form the closed core segment 300, and the upright punches 710 are stacked to form the upright core segment 700.
[0057] The present application stacks a closed core segment 300 formed by stacking closed punches 310 with m pairs of offset core segments 100 formed by stacking offset punches 110, and at the same time reasonably sets the offset angle between the axis of the slot 210 of the offset punch 110 and the axis of the open stator slot 200 in the m pairs of offset core segments 100, thereby reducing the cogging torque under the condition of straight rotor poles to avoid a decrease in the output capacity of the peak torque.
[0058] Example 2
[0059] Embodiment 2 of the present application provides a stator assembly, which includes any stator core provided in the present application.
[0060] Example 3
[0061] A third embodiment of the present application provides a permanent magnet motor, which includes any stator assembly provided in the present application.
[0062] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0063] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.
Claims
1. A stator core, characterized in that: The stator core comprises m pairs of offset core segments (100), wherein m is a positive integer not less than 1; the offset core segments (100) are formed by stacking offset punches (110); the offset punches (110) are provided with open stator slots (200); a notch (210) is provided on one side of the open stator slots (200) close to the inner side of the offset punches (110); the open stator slots (200) and the notch (210) are both axisymmetric structures; in the same pair of offset core segments (100), the notches of all the offset punches (110) on one offset core segment (100) are The axis of the stator core (210) and the axis of the open stator slot (200) are both positively offset by n*θ, and the axes of the slots (210) of all the offset punching sheets (110) on another offset core segment (100) and the axis of the open stator slot (200) are both negatively offset by n*θ, wherein n is a positive integer not less than 1; the stator core further comprises a closed core segment (300), the closed core segment (300) is formed by stacking closed punching sheets (310), a closed stator slot (400) is provided on the closed core segment (300), and no slot (210) is provided on the closed stator slot (400).
2. The stator core according to claim 1, characterized in that A plurality of open slot teeth (500) are provided on the inner side of the offset punch (110), and two adjacent open slot teeth (500) on the offset punch (110) are spaced apart to enclose and form the open stator slot (200); a first tooth portion (510) and a second tooth portion (520) are provided on the side close to each other of the adjacent two open slot teeth (500), and the first tooth portion (510) and the second tooth portion (520) are spaced apart to form the slot ( 210); on the offset punching sheet (110) in which the axis of the slot opening (210) and the axis of the open stator slot (200) are positively offset by n*θ, the length of the first tooth portion (510) is greater than the length of the second tooth portion (520); on the offset punching sheet (110) in which the axis of the slot opening (210) and the axis of the open stator slot (200) are negatively offset by n*θ, the length of the first tooth portion (510) is less than the length of the second tooth portion (520).
3. The stator core according to claim 1, characterized in that A plurality of closed slot teeth (600) are provided on the inner side of the closed punching sheet (310), and two adjacent closed slot teeth (600) on the closed punching sheet (310) are connected and hollowed out in the middle to enclose and form the closed stator slot (400).
4. The stator core according to claim 1, wherein: The stator core further comprises an upright core segment (700), the upright core segment (700) being formed by stacking upright punching sheets (710), the upright punching sheets (710) being provided with open stator slots (200) and slot openings (210), and the axes of the open stator slots (200) of all the upright punching sheets (710) on the upright core segment (700) coincide with the axes of the slot openings (210).
5. The stator core according to claim 4, characterized in that A plurality of open slot teeth (500) are provided on the inner side of the upright punching sheet (710), and two adjacent open slot teeth (500) on the upright punching sheet (710) are spaced apart to enclose and form the open stator slot (200); a first tooth portion (510) and a second tooth portion (520) are respectively provided on the side where the two adjacent open slot teeth (500) are close to each other, and the first tooth portion (510) and the second tooth portion (520) are spaced apart to form the slot opening (210); the length of the first tooth portion (510) on the upright punching sheet (710) is equal to the length of the second tooth portion (520).
6. The stator core according to claim 4, characterized in that The offset punching sheet (110), the closed punching sheet (310) and the upright punching sheet (710) are all made of silicon steel sheets.
7. The stator core according to claim 1, characterized in that m pairs of offset core segments (100) are axially superimposed on both sides of the closed core segment (300) and are symmetrically arranged along the axial direction of the closed core segment (300).
8. The stator core according to claim 1, characterized in that The open stator slot (200) is aligned with the outer edge of the closed stator slot (400).
9. A stator assembly, characterized in that: The stator assembly comprises the stator core according to any one of claims 1 to 8.
10. A permanent magnet motor, characterized in that: The permanent magnet motor comprises the stator assembly according to claim 9.