Stator punching sheet, stator core and motor

Abstract

The invention provides a stator punching sheet, a stator core and a motor, the stator punching sheet comprises a stator yoke ring and a plurality of stator teeth which are located on the inner ring wall surface of the stator yoke ring and are uniformly arranged at intervals around the circumferential direction of the stator yoke ring, and a stator slot is formed between every two adjacent stator teeth. The stator slots are continuously divided into a plurality of slot groups along the circumferential direction of the stator yoke ring, the number of the slot groups is equal to the number of poles of a rotor of a motor using the stator punching sheet, the number of the stator slots in each slot group is an even number, and the two stator slots in the middle in each slot group are respectively a first stator slot and a second stator slot; a stator tooth shared by the first stator slot and the second stator slot is a central stator tooth, and a first auxiliary slot and a second auxiliary slot are respectively arranged on two sides of the central stator tooth in the circumferential direction. According to the invention, the local magnetic flux density peak value can be reduced, the iron loss is reduced, the motor efficiency is improved, the heat dissipation capability of the stator core is improved, and the motor reliability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of motor design, and in particular relates to a stator punching sheet, a stator core, and a motor. Background Art

[0002] As motor technology continues to advance toward higher power density and higher efficiency, stator core thermal management and losses are increasingly becoming key factors restricting motor performance. Traditional motor stator cores typically utilize a uniform lamination structure, whose heat dissipation capacity relies on external cooling systems (such as air cooling or liquid cooling) or the thermal conductivity of the core material. However, under high-load, high-frequency operating conditions, the hysteresis and eddy current losses (collectively referred to as iron losses) generated by the alternating magnetic field within the stator core increase significantly, leading to increased local core temperature rise, which in turn causes insulation material aging and magnetic property degradation, severely reducing motor operating efficiency and reliability.

[0003] In existing technologies, although heat dissipation can be improved by optimizing silicon steel sheet materials (such as using high-grade non-oriented silicon steel), increasing the number of cooling channels, or introducing composite cooling media, these solutions often have drawbacks such as high cost, complex processes, or increased energy consumption, making it difficult to achieve coordinated optimization of core temperature rise and iron loss while ensuring economy. In addition, traditional stator core designs have limited control over magnetic circuit distribution. Especially in high-speed motors or high-frequency variable frequency drive scenarios, local saturation and harmonic components of magnetic flux density will aggravate eddy current losses within the core, further worsening temperature rise. Although some studies have proposed adding heat dissipation fins or embedding thermally conductive fillers on the core surface, these methods may destroy the uniformity of the magnetic circuit and lead to increased additional losses. Summary of the Invention

[0004] Therefore, the present invention provides a stator punching sheet, a stator core, and a motor, which can overcome the technical problems of high motor iron loss, heat dissipation difficulty, and low efficiency when the stator punching sheets in the related art are used in the motor.

[0005] In order to solve the above problems, the present invention provides a stator punching sheet, comprising a stator yoke ring and a plurality of stator teeth on the inner ring wall surface of the stator yoke ring, which are evenly spaced in the circumferential direction around the stator yoke ring. A stator slot is formed between two adjacent stator teeth. The stator slots are continuously divided into multiple slot groups along the circumferential direction of the stator yoke ring. The number of the slot groups is equal to the number of poles of the rotor of the motor used for the stator punching sheet. The number of stator slots in each slot group is an even number. The two central stator slots in each slot group are respectively a first stator slot and a second stator slot. The stator tooth shared by the first stator slot and the second stator slot is a central stator tooth. A first auxiliary slot and a second auxiliary slot are respectively provided on both sides of the circumferential direction of the central stator tooth, wherein the first auxiliary slot is connected to the first stator slot, and the second auxiliary slot is connected to the second stator slot.

[0006] In some embodiments, the first auxiliary slot is located between the tooth shoe of the central stator tooth and the second auxiliary slot, and a slot area of ​​the first auxiliary slot is smaller than a slot area of ​​the second auxiliary slot.

[0007] In some embodiments, the radial slot height of each stator slot is Bh, and the circumferential slot width is Bw, the radial slot height of the first auxiliary slot is Eh1, and the circumferential slot width is Ew1, Bh / Eh1=5.5~5.7, Bw / Ew1=3.85~3.95.

[0008] In some embodiments, the radial groove height of the second auxiliary groove is Eh2, the circumferential groove width is Ew2, Bh / Eh2=1.78~1.81, and Bw / Ew2=3.15~3.25.

[0009] In some embodiments, the slot shapes of the first auxiliary slot and the second auxiliary slot are both semicircular with diameters located on the tooth side walls of the central stator tooth, the center point of the second auxiliary slot is OE, and the radial distance between OE and the slot bottom wall of the second stator slot is H, H=(53%~55%)Bh; and / or the slot wall of the first auxiliary slot is tangent to the radial outer wall of the tooth shoe of the central stator tooth.

[0010] In some embodiments, a third auxiliary groove is provided on the outer ring wall surface of the stator yoke ring corresponding to each slot group, the maximum radial groove depth of the third auxiliary groove is Fd, the radial width of the stator yoke ring is Dw, and Fd / Dw=0.09~0.1.

[0011] In some embodiments, two circumferentially adjacent slot groups share a stator tooth, which is defined as a side stator tooth. In the same slot group, the central angle formed between the tooth symmetry line of the side stator tooth and the tooth symmetry line of the central stator tooth is a, a=180° / p, p is the number of poles of the rotor, and the third auxiliary slot is located on the side of the tooth symmetry line of the central stator tooth close to the second auxiliary slot. The outer end point of the slot wall on one side of the slot opening of the third auxiliary slot is the first end point, and the outer end point of the slot wall on the other side is the second end point. The first end point is on the tooth symmetry line of the side stator tooth. The first and second end points form a central angle b with the center of the stator punching as the vertex, b / a=0.11~0.14.

[0012] In some embodiments, the third auxiliary groove is a minor arc groove.

[0013] The present invention further provides a stator core, comprising the above-mentioned stator punching sheets, wherein the stator punching sheets are stacked along the axial direction and the first auxiliary slots, the second auxiliary slots and the third auxiliary slots are positioned correspondingly in the axial direction.

[0014] The present invention also provides a motor comprising the above-mentioned stator core.

[0015] The stator punching sheet, stator core, and motor provided by the present invention have the following beneficial effects: Within each slot group, the first and second auxiliary slots are positioned on opposite sides of the central stator tooth, respectively. This allows for refined segmentation of the magnetic circuit within the stator core, reducing local magnetic flux density peaks, reducing iron loss, and improving motor efficiency. This also expands the slot area of ​​the first and second stator slots, further enhancing the stator core's heat dissipation capacity and motor reliability. This dual optimization of stator core heat dissipation and iron loss has been demonstrated to improve the motor's overall operating efficiency by 0.8% to 1.5%. For new energy vehicle drive motors, this efficiency gain can significantly reduce long-term operating energy consumption, aligning with green manufacturing and carbon neutrality goals. It is important to emphasize that the placement of the first and second auxiliary slots on either side of the central stator tooth within each slot group creates a symmetrical distribution of magnetic circuits within each stator core pole, contributing to a uniform magnetic field, reducing vibration and noise during motor operation, and improving motor smoothness. This symmetrical distribution of magnetic circuits also ensures excellent motor stability and reliability under varying load conditions, preventing failures caused by local overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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 the embodiments or the description of the prior art. The drawings described below are merely exemplary. Those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0017] Figure 1 is an axial projection diagram of a stator punching sheet according to an embodiment of the present invention; Figure 2 yes Figure 1 A partial schematic diagram of the stator punching corresponding to a slot group in ( Figure 1 1 / 8 of the stator punching in the Figure 3 yes Figure 2 Schematic diagram of the marking of dimensional parameters such as the radial slot height and circumferential slot width of the stator slot in the stator punching structure, the radial slot height (at the maximum position) and circumferential slot width of the first auxiliary slot, and the radial slot height and circumferential slot width of the second auxiliary slot; Figure 4 yes Figure 2Schematic illustration of the dimension parameters of the stator punching structure, such as the radial width of the ring body, the maximum radial slot depth, the central angle formed between the tooth symmetry line of the side stator teeth and the tooth symmetry line of the central stator teeth, and the central angle formed by the first end point and the second end point with the center of the stator punching as the vertex; Figure 5 This is a partial magnetic density simulation cloud diagram of a stator punching in the prior art that does not adopt the technical solution of the present invention; Figure 6 This is a partial magnetic density simulation cloud diagram of a stator lamination using the technical solution of the present invention; Figure 7 is a comparison curve of the stator iron loss of the stator adopting the technical solution of the present invention (this proposal) and the technical solution not adopting the present invention (the prior art); Figure 8 It is a comparison curve diagram of the motor efficiency using the technical solution of the present invention (this proposal) and the technical solution not using the present invention (existing technology).

[0018] The accompanying drawings are: 1. Stator yoke ring; 11. Third auxiliary slot; 111. First endpoint; 112. Second endpoint; 2. Stator tooth; 21. Central stator tooth; 211. First auxiliary slot; 212. Second auxiliary slot; 22. Side stator tooth; 3. Stator slot; 31. First stator slot; 32. Second stator slot. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0021] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "upper" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" other devices or structures would then be positioned as "below" or "below" the other devices or structures. Thus, the exemplary term "above" can include both the "above" and "below" orientations. The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0022] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0023] See also Figures 1 to 8 As shown, according to an embodiment of the present invention, a stator punching sheet is provided, comprising a stator yoke ring 1 and a plurality of stator teeth 2 on the inner ring wall surface of the stator yoke ring 1 and arranged evenly spaced in the circumferential direction around the stator yoke ring 1, a stator slot 3 is formed between two adjacent stator teeth 2, and the stator slots 3 are continuously divided into a plurality of slot groups along the circumferential direction of the stator yoke ring 1, the number of the slot groups is equal to the number of poles of the rotor of the motor to which the stator punching sheet is applied, and the number of the stator slots 3 in each slot group is an even number, as shown in FIG. Figure 1 As shown, in this specific embodiment, there are a total of eight slot groups, each slot group has six stator slots, that is, the stator punching in this embodiment is specifically suitable for an 8-pole 48-slot stator core, and the two central stator slots 3 in each slot group are the first stator slot 31 and the second stator slot 32, respectively. The stator tooth 2 shared by the first stator slot 31 and the second stator slot 32 is the central stator tooth 21, and a first auxiliary slot 211 and a second auxiliary slot 212 are respectively provided on both circumferential sides of the central stator tooth 21, wherein the first auxiliary slot 211 is connected to the first stator slot 31, and the second auxiliary slot 212 is connected to the second stator slot 32.

[0024] In this technical solution, a first auxiliary slot 211 and a second auxiliary slot 212 are respectively provided on opposite sides of the stator tooth at the center position in each slot group, that is, the central stator tooth 21, which can realize the refined segmentation of the magnetic circuit in the stator core, reduce the local magnetic flux density peak, reduce iron loss, and improve the motor efficiency. At the same time, the slot area of ​​the first stator slot 31 and the second stator slot 32 is expanded, thereby improving the heat dissipation capacity of the stator core, improving the reliability of the motor, and achieving dual optimization of the heat dissipation and iron loss of the stator core. It has been verified that the overall operating efficiency of the motor can be increased by 0.8%~1.5%. For new energy vehicle drive motors, this efficiency gain can significantly reduce long-term operating energy consumption, which is in line with the goals of green manufacturing and carbon neutrality. It should be particularly emphasized that since the first auxiliary slot 211 and the second auxiliary slot 212 are located on both sides of the central stator tooth 21 in each slot group, the magnetic circuit of each pole of the stator core is symmetrically distributed, which helps to form a uniform magnetic field, reduce vibration and noise during motor operation, and improve the smooth operation of the motor. The symmetrically distributed magnetic circuit can also ensure that the motor can maintain good stability and reliability under different load conditions, avoiding failures caused by problems such as local overheating.

[0025] In some embodiments, the first auxiliary slot 211 is located between the tooth shoe of the central stator tooth 21 and the second auxiliary slot 212, and the slot area of ​​the first auxiliary slot 211 is smaller than the slot area of ​​the second auxiliary slot 212. For details, see Figure 2 As shown, the first auxiliary slot 211 is disposed adjacent to the tooth shoe of the central stator tooth 21 , while the second auxiliary slot 212 is disposed adjacent to the tooth root of the central stator tooth 21 .

[0026] In this technical solution, since the magnetic flux density shows a characteristic in the radial direction of the central stator tooth 21 that the saturation of the radially inner magnetic flux density is smaller than that of the radially outer magnetic flux density, the slot area of ​​the first auxiliary slot 211 on the radially inner side is correspondingly designed to be smaller than the slot area of ​​the second auxiliary slot 212 on the radially outer side. In this way, the magnetic flux density saturation on the stator tooth can be reduced in different regions according to the degree of magnetic flux density saturation, thereby preventing the output torque from decreasing due to excessive reduction in magnetic flux density.

[0027] See Figure 3As shown, in some embodiments, the radial slot height of each stator slot 3 is Bh, and the circumferential slot width is Bw. The radial slot height (at the maximum position) of the first auxiliary slot 211 is Eh1, and the circumferential slot width (at the maximum position) is Ew1, with Bh / Eh1=5.5-5.7 and Bw / Ew1=3.85-3.95. The radial slot height (at the maximum position) of the second auxiliary slot 212 is Eh2, and the circumferential slot width (at the maximum position) is Ew2, with Bh / Eh2=1.78-1. 81, Bw / Ew2=3.15~3.25, further, the slot shapes of the first auxiliary slot 211 and the second auxiliary slot 212 are both semicircular with a diameter located on the tooth side wall of the central stator tooth 21, the center point of the second auxiliary slot 212 is OE, and the radial distance between OE and the slot bottom wall of the second stator slot 32 is H, H=(53%~55%)Bh; and / or the slot wall of the first auxiliary slot 211 is tangent to the radial outer wall of the tooth shoe of the central stator tooth 21.

[0028] In this technical solution, by reasonably limiting the shape and position of the first auxiliary slot 211 and the second auxiliary slot 212, it is possible to effectively constrain the main magnetic flux path on the stator punching sheet corresponding to the slot group, further avoid local magnetic density saturation, reduce iron loss, achieve a reasonable expansion of the stator slot area, and improve the heat dissipation capacity of the motor. Figure 7 As shown, Figure 7 This is a comparison chart of the iron loss of the proposal (i.e., adopting the technical solution of the present invention) and the prior art (i.e., not adopting the technical solution of the present invention) at different torque points under rated speed. The horizontal axis is the output torque and the vertical axis is the motor iron loss. After adopting the technical solution of the present invention, the overall iron loss of the motor can be reduced by 20%~25%.

[0029] See also Figure 4As shown, in some embodiments, a third auxiliary slot 11 is provided on the outer ring wall surface of the stator yoke ring 1 corresponding to each slot group, the maximum radial slot depth of the third auxiliary slot 11 is Fd, the radial width of the ring body of the stator yoke ring 1 (that is, the yoke width) is Dw, and Fd / Dw=0.09~0.1; further, two circumferentially adjacent slot groups share a stator tooth 2, which is defined as a side stator tooth 22. In the same slot group, the central angle formed between the tooth symmetry line of the side stator tooth 22 and the tooth symmetry line of the central stator tooth 21 is a, a=180° / p, p is the number of poles of the rotor, and The third auxiliary slot 11 is located on the side of the tooth symmetry line of the central stator tooth 21 close to the second auxiliary slot 212. The outer end point of the slot wall on one side of the slot opening of the third auxiliary slot 11 is a first end point 111, and the outer end point of the slot wall on the other side is a second end point 112. The first end point 111 is located on the tooth symmetry line of the side stator tooth 22. The central angle b formed by the first end point 111 and the second end point 112 with the center of the stator punching as the vertex is b / a=0.11~0.14. In a specific embodiment, the third auxiliary slot 11 is a minor arc slot, that is, the central angle b is less than 180°.

[0030] In this technical solution, by reasonably limiting the shape and position of the third auxiliary slot 11, the motor can further reduce iron loss and improve motor efficiency while ensuring that the output torque remains basically unchanged. Figure 8 As shown, Figure 8 This is a comparison chart of the efficiency of the proposal (i.e., adopting the technical solution of the present invention) and the existing technology (i.e., not adopting the technical solution of the present invention) at different torque points under rated speed. The horizontal axis is the output torque and the vertical axis is the motor efficiency. After adopting the technical solution of the present invention, the overall efficiency of the motor can be improved by 0.8%~1.5%.

[0031] See also Figure 5 and Figure 6 As shown, by comparison, it can be seen that the use of the first auxiliary slot 211 and the second auxiliary slot 212 of the present invention can effectively reduce the magnetic density oversaturation area and reduce the iron loss.

[0032] According to an embodiment of the present invention, a stator core is further provided, comprising the above-mentioned stator punching sheets, wherein the stator punching sheets are stacked along the axial direction and the first auxiliary slots 211, the second auxiliary slots 212 and the third auxiliary slots 11 correspond to each other in the axial direction, that is, the first auxiliary slots 211, the second auxiliary slots 212 and the third auxiliary slots 11 in each slot group have their axial projections on the stator core overlap.

[0033] The radial, circumferential and axial directions mentioned above are all consistent with the radial, circumferential or axial directions of the stator punching sheets or the stator core or the motor.

[0034] According to an embodiment of the present invention, a motor is further provided, comprising the above-mentioned stator core.

[0035] It is easy for those skilled in the art to understand that, under the premise of no conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A stator punching sheet, characterized in that: The invention comprises a stator yoke ring (1) and a plurality of stator teeth (2) on the inner ring wall of the stator yoke ring (1) and arranged at even intervals in the circumferential direction of the stator yoke ring (1), wherein a stator slot (3) is formed between two adjacent stator teeth (2), and the stator slots (3) are continuously divided into a plurality of slot groups along the circumferential direction of the stator yoke ring (1), the number of the slot groups is equal to the number of poles of the rotor of the motor to which the stator punching sheet is applied, the number of the stator slots (3) in each slot group is an even number, and the number of the stator slots (3) in each slot group is an even number. The two central stator slots (3) are respectively a first stator slot (31) and a second stator slot (32); the stator tooth (2) shared by the first stator slot (31) and the second stator slot (32) is a central stator tooth (21); a first auxiliary slot (211) and a second auxiliary slot (212) are respectively provided on both circumferential sides of the central stator tooth (21); wherein the first auxiliary slot (211) is communicated with the first stator slot (31), and the second auxiliary slot (212) is communicated with the second stator slot (32).

2. The stator sheet according to claim 1, characterized in that: The first auxiliary slot (211) is located in a region between the tooth shoe of the central stator tooth (21) and the second auxiliary slot (212), and a slot area of ​​the first auxiliary slot (211) is smaller than a slot area of ​​the second auxiliary slot (212).

3. The stator sheet according to claim 1 or 2, characterized in that: The radial slot height of each stator slot (3) is Bh, and the circumferential slot width is Bw; the radial slot height of the first auxiliary slot (211) is Eh1, and the circumferential slot width is Ew1; Bh / Eh1=5.5~5.7, and Bw / Ew1=3.85~3.

95.

4. The stator sheet according to claim 3, characterized in that: The radial groove height of the second auxiliary groove (212) is Eh2, the circumferential groove width is Ew2, Bh / Eh2=1.78~1.81, Bw / Ew2=3.15~3.

25.

5. The stator punching sheet according to claim 4, characterized in that: The groove shapes of the first auxiliary groove (211) and the second auxiliary groove (212) are both semicircular with diameters located on the tooth side wall of the central stator tooth (21), the center point of the second auxiliary groove (212) is OE, and the radial distance between OE and the groove bottom wall of the second stator groove (32) is H, H=(53%~55%)Bh; and / or the groove wall of the first auxiliary groove (211) is tangent to the radial outer wall of the tooth shoe of the central stator tooth (21).

6. The stator punching sheet according to claim 1, characterized in that: A third auxiliary groove (11) is provided on the outer ring wall surface of the stator yoke ring (1) corresponding to each slot group, the maximum radial groove depth of the third auxiliary groove (11) is Fd, the radial width of the ring body of the stator yoke ring (1) is Dw, and Fd / Dw=0.09~0.

1.

7. The stator sheet according to claim 6, characterized in that: Two circumferentially adjacent slot groups share a stator tooth (2), which is defined as a side stator tooth (22). In the same slot group, a central angle a is formed between a tooth symmetry line of the side stator tooth (22) and a tooth symmetry line of the central stator tooth (21), and a=180° / p, where p is the number of poles of the rotor. The third auxiliary slot (11) is located on the side of the tooth symmetry line of the central stator tooth (21) close to the second auxiliary slot (212). The outer end point of the slot wall on one side of the slot opening of the third auxiliary slot (11) is a first end point (111), and the outer end point of the slot wall on the other side is a second end point (112). The first end point (111) is located on the tooth symmetry line of the side stator tooth (22). The central angle b formed by the first end point (111) and the second end point (112) with the center of the stator punching sheet as the vertex is b / a=0.11~0.

14.

8. The stator sheet according to claim 7, characterized in that: The third auxiliary groove (11) is a minor arc groove.

9. A stator core, characterized in that: The stator punching sheet comprises any one of claims 1 to 8, wherein the stator punching sheets are stacked along the axial direction and the first auxiliary slots (211), the second auxiliary slots (212) and the third auxiliary slots (11) correspond in axial position.

10. A motor, characterized in that: The stator core according to claim 9 is included.

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