Stator lamination, Stator core, Electric machine

Abstract

The application provides a kind of stator lamination, stator core, motor, wherein the stator lamination includes a stator yoke ring and a plurality of stator teeth uniformly spaced around the circumferential direction of the stator yoke ring on the inner ring wall surface of the stator yoke ring, a stator slot is formed between two adjacent stator teeth, the stator slot is continuously divided into a plurality of slot groups along the circumferential direction of the stator yoke ring, the number of slot groups is equal to the number of poles of the rotor of the motor to which the stator lamination is applied, the number of stator slots in each slot group is an even number, the two stator slots in the middle of each slot group are a first stator slot and a second stator slot, respectively, 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 the two sides of the central stator tooth in the circumferential direction. The application can reduce the local magnetic flux density peak value, reduce the iron loss, improve the motor efficiency, improve the heat dissipation capacity of the stator core, and improve the reliability of the motor.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor design, and particularly relates to a stator lamination, a stator core and a motor. BACKGROUND

[0002] With the continuous development of motor technology towards high power density and high efficiency, the thermal management and loss of the stator core have increasingly become key factors restricting the performance improvement of the motor. The traditional stator core of the motor usually adopts a uniform lamination structure, and its heat dissipation capacity depends on an external cooling system (such as air cooling or liquid cooling) or the thermal conductivity of the core material. However, under high load and high frequency conditions, the magnetic hysteresis loss and eddy current loss (collectively referred to as iron loss) generated in the stator core due to the action of the alternating magnetic field significantly increase, leading to intensified local temperature rise of the core, and thus causing problems such as aging of the insulating material and degradation of the magnetic performance, which seriously reduces the operating efficiency and reliability of the motor.

[0003] In the prior art, although the heat dissipation can be improved by optimizing the silicon steel sheet material (such as using high-grade non-oriented silicon steel), increasing the number of cooling channels or introducing a composite cooling medium, these schemes often have defects such as high cost, complex process or increased additional energy consumption, and it is difficult to realize the coordinated optimization of the core temperature rise and iron loss under the premise of ensuring economy. In addition, the traditional stator core design has limited ability to regulate the magnetic circuit distribution, especially in high-speed motor or high-frequency variable frequency driving scenarios, the local saturation of the magnetic flux density and the harmonic component will intensify the eddy current loss in the core, further worsening the temperature rise. Although some studies have proposed adding heat dissipation fins or embedding heat-conducting fillers on the surface of the core, these methods may destroy the uniformity of the magnetic circuit, leading to increased additional loss. SUMMARY

[0004] Therefore, the present application provides a stator lamination, a stator core and a motor, which can overcome the technical problems of large motor iron loss, poor heat dissipation and low efficiency of the stator lamination of the related art when applied to a motor.

[0005] In order to solve the above problems, the present application provides a stator lamination, which comprises a stator yoke ring and a plurality of stator teeth uniformly spaced in the circumferential direction of the stator yoke ring on the inner ring wall surface of the stator yoke ring, a stator slot is formed between adjacent two stator teeth, the stator slot is 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 to which the stator lamination is applied, the number of stator slots in each slot group is an even number, the two stator slots in the middle of each slot group are a first stator slot and a second stator slot, respectively, and 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 the two sides of the central stator tooth in the circumferential direction, wherein the first auxiliary slot is in communication with the first stator slot, and the second auxiliary slot is in communication with the second stator slot.

[0006] In some embodiments, the first auxiliary slot is located in a region between a tooth heel 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, a radial slot height of each of the stator slots is Bh, a circumferential slot width is Bw, a radial slot height of the first auxiliary slot is Eh1, a circumferential slot width is Ew1, Bh / Eh1 = 5.5-5.7, and Bw / Ew1 = 3.85-3.95.

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

[0009] In some embodiments, the first auxiliary slot and the second auxiliary slot are both semicircular in shape with a diameter on a tooth side wall of the central stator tooth, a center point of the second auxiliary slot is OE, a radial distance of the OE from a slot bottom wall of the second stator slot is H, H = (53%-55%) Bh, and / or a slot wall of the first auxiliary slot is tangent to a radially outer wall of the tooth heel of the central stator tooth.

[0010] In some embodiments, each of the slot groups has a third auxiliary slot on an outer ring wall surface of the stator yoke ring corresponding thereto, a maximum radial slot depth of the third auxiliary slot is Fd, a ring body radial width of the stator yoke ring is Dw, and Fd / Dw = 0.09-0.1.

[0011] In some embodiments, circumferentially adjacent two slot groups share a stator tooth, which is defined as a side stator tooth, in the same slot group, a central angle formed between a tooth symmetry line of the side stator tooth and a tooth symmetry line of the central stator tooth is a, a = 180° / p, p is a pole number of a rotor, the third auxiliary slot is located on a side of the tooth symmetry line of the central stator tooth close to the second auxiliary slot, a side slot wall outer end point of a slot opening of the third auxiliary slot is a first end point, and another side slot wall outer end point is a second end point, the first end point is on the tooth symmetry line of the side stator tooth, and a central angle b of a circle with a center at a center of the stator lamination formed by the first end point and the second end point is b / a = 0.11-0.14.

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

[0013] The application also provides a stator core comprising the stator laminations described above, each of the stator laminations is stacked along an axial direction, and each of the first auxiliary slot, the second auxiliary slot, and the third auxiliary slot is axially positionally corresponding.

[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:

[0016] 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

[0017] 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.

[0018] Figure 1 is an axial projection diagram of a stator punching sheet according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A partial schematic diagram of the stator lamination corresponding to a slot group in the Figure 1 1 / 8 of the stator punching in the

[0020] 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;

[0021] Figure 4 yes Figure 2The ring body radial width, the maximum radial slot depth, the central angle formed between the tooth symmetry line of the side stator tooth and the tooth symmetry line of the central stator tooth, the central angle formed by the first end point and the second end point with the center of the stator lamination as the vertex, and other size parameters in the stator lamination structure in the figure are labeled;

[0022] Figure 5 The magnetic density simulation nephogram (part) of the stator lamination in the prior art without the technical scheme of the present application is shown in the figure;

[0023] Figure 6 The magnetic density simulation nephogram (part) of the stator lamination with the technical scheme of the present application is shown in the figure;

[0024] Figure 7 The comparison curve of the stator iron loss of the technical scheme (the present proposal) of the present application and the technical scheme (the prior art) without the present application is shown in the figure;

[0025] Figure 8 The comparison curve of the motor efficiency of the technical scheme (the present proposal) of the present application and the technical scheme (the prior art) without the present application is shown in the figure.

[0026] The reference signs are:

[0027] 1, stator yoke ring; 11, third auxiliary slot; 111, first end point; 112, second end point; 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

[0028] The technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] In the description of the present application, it needs to be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship is generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element indicated must have a particular orientation or be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0030] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0031] In addition, it should be noted that the use of "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, therefore cannot be understood as a limitation on the scope of protection of the present application.

[0032] For reference Figures 1 to 8 As shown, according to the embodiment of the present application, a stator lamination is provided, which comprises a stator yoke 1 and a plurality of stator teeth 2 uniformly spaced along the circumferential direction of the stator yoke 1 on the inner ring wall surface of the stator yoke 1, a stator slot 3 is formed between adjacent two stator teeth 2, the stator slot 3 is continuously divided into a plurality of slot groups along the circumferential direction of the stator yoke 1, the number of the slot groups is equal to the number of poles of the rotor of the motor to which the stator lamination is applied, and the number of stator slots 3 in each slot group is an even number, such as Figure 1As shown, in this specific embodiment, there are eight slot groups in total, each slot group has six stator slots, that is, the stator lamination in this embodiment is particularly suitable for an 8-pole 48-slot stator core, the two stator slots 3 in the middle of each slot group 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 arranged on the circumferential sides of the central stator tooth 21, wherein the first auxiliary slot 211 is in communication with the first stator slot 31, and the second auxiliary slot 212 is in communication with the second stator slot 32.

[0033] In this technical solution, the first auxiliary slot 211 and the second auxiliary slot 212 are respectively arranged on the opposite sides of the central stator tooth 21 in each slot group, which can realize fine segmentation of the magnetic circuit in the stator core, reduce the local magnetic flux density peak value, reduce the iron loss, and improve the motor efficiency. At the same time, it also realizes the expansion of the slot area of the first stator slot 31 and the second stator slot 32, thereby improving the heat dissipation capacity of the stator core and improving the reliability of the motor, realizing the double optimization of heat dissipation and iron loss of the stator core. It has been verified that the overall operation efficiency of the motor can be improved by 0.8%~1.5%, and for new energy vehicle driving motors, this efficiency gain can significantly reduce long-term operation energy consumption, which is in line with the goals of green manufacturing and carbon neutralization. It needs to be particularly emphasized that because the first auxiliary slot 211 and the second auxiliary slot 212 are located on the two 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, reduces vibration and noise during motor operation, and improves the running stability 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 local overheating and other problems.

[0034] In some embodiments, the first auxiliary slot 211 is located in the area 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, as shown in Figure 2 As shown, the first auxiliary slot 211 is arranged adjacent to the tooth shoe position of the central stator tooth 21, and the second auxiliary slot 212 is arranged adjacent to the tooth root position of the central stator tooth 21.

[0035] In this technical solution, because the magnetic density in the radial direction of the central stator tooth 21 has the characteristic that the saturation degree of the magnetic density on the inner side is smaller than that on the outer side, the slot area of the first auxiliary slot 211 on the inner side is designed to be smaller than that of the second auxiliary slot 212 on the outer side, which can reduce the magnetic density saturation degree on the stator tooth according to the magnetic density saturation degree, and prevent the output torque from being reduced by excessively reducing the magnetic density.

[0036] With reference to the drawings in detail, Figure 3 As shown in some embodiments, the radial slot height of each stator slot 3 is Bh, the circumferential slot width is Bw, the radial slot height (at the maximum position) of the first auxiliary slot 211 is Eh1, the circumferential slot width (at the maximum position) is Ew1, Bh / Eh1=5.5~5.7, Bw / Ew1=3.85~3.95; the radial slot height (at the maximum position) of the second auxiliary slot 212 is Eh2, the circumferential slot width (at the maximum position) is Ew2, Bh / Eh2=1.78~1.81, Bw / Ew2=3.15~3.25, further, the slot shape of the first auxiliary slot 211 and the second auxiliary slot 212 is a semicircle with a diameter on the tooth side wall of the central stator tooth 21, the center point of the semicircle of the second auxiliary slot 212 is OE, the radial distance of the OE from 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 tooth shoe radial outer wall of the central stator tooth 21.

[0037] In this technical solution, by reasonably limiting the shape and position of the first auxiliary slot 211 and the second auxiliary slot 212, the main magnetic flux path on the stator lamination corresponding to the slot group can be effectively constrained, further avoiding local magnetic density saturation, reducing iron loss, realizing rational expansion of the stator slot area, and improving the motor heat dissipation capacity, such as Figure 7 As shown, Figure 7 The figure is an iron loss comparison chart of different torque points under the rated speed of the present application (i.e., using the technical solution of the present application) and the prior art (i.e., not using the technical solution of the present application), the horizontal coordinate is the output torque, and the vertical coordinate is the motor iron loss. After using the technical solution of the present application, the overall iron loss of the motor can be reduced by 20%~25%.

[0038] Referring to Figure 4As shown, in some embodiments, the outer ring wall surface of the stator yoke ring 1 corresponding to each slot group has a third auxiliary slot 11, the maximum radial slot depth of the third auxiliary slot 11 is Fd, the ring body radial width (i.e. yoke width) of the stator yoke ring 1 is Dw, Fd / Dw = 0.09~0.1; further, two circumferentially adjacent slot groups share a stator tooth 2, defined as a side stator tooth 22, in the same slot group, the tooth symmetry line of the side stator tooth 22 and the tooth symmetry line of the central stator tooth 21 form a central angle a, a = 180° / p, p is the pole number 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, one side slot wall outer end point of the slot opening of the third auxiliary slot 11 is a first end point 111, the other side slot wall outer end point 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 first end point 111 and the second end point 112 form a central angle b with the center of the stator lamination as the vertex, b / a = 0.11~0.14, in a specific embodiment, the third auxiliary slot 11 is a poor arc slot, i.e. the aforementioned central angle b is less than 180°.

[0039] In the technical solution, by reasonably limiting the shape and position of the third auxiliary slot 11, the motor further reduces the iron loss and improves the motor efficiency under the condition of ensuring that the output torque is basically unchanged, such as Figure 8 As shown, Figure 8 The comparison chart of the efficiency of the present application (i.e. using the technical solution of the present application) and the efficiency of the prior art (i.e. not using the technical solution of the present application) at different torque points under the rated speed, the horizontal coordinate is the output torque, and the vertical coordinate is the motor efficiency. After using the technical solution of the present application, the overall efficiency of the motor can be improved by 0.8%~1.5%.

[0040] As shown in Figure 5 and Figure 6 As can be seen from the comparison, due to the adoption of the first auxiliary slot 211 and the second auxiliary slot 212 of the present application, the magnetic flux saturation region can be effectively reduced, and the iron loss can be reduced.

[0041] According to the embodiments of the present application, a stator core is also provided, which comprises the above-mentioned stator laminations, each stator lamination is stacked along the axial direction, and each first auxiliary slot 211, second auxiliary slot 212 and third auxiliary slot 11 are positionally corresponding in the axial direction, i.e. the projection of each first auxiliary slot 211, second auxiliary slot 212 and third auxiliary slot 11 in each slot group in the axial direction of the stator core is coincident.

[0042] The radial direction, circumferential direction and axial direction described in the foregoing are consistent with the radial direction, circumferential direction and axial direction of the stator lamination or the stator core or the motor.

[0043] According to the embodiment of the present application, there is also provided an electric machine comprising the stator core as described above.

[0044] Those skilled in the art will readily understand that the advantageous features of the various modes of implementation described above can be freely combined, superimposed.

[0045] The above description is merely preferred embodiments of the present application, but not to limit the present application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above description is merely preferred embodiments of the present application, but not to limit the present application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A stator lamination characterized by, The application relates to a stator lamination for a motor, which comprises a stator yoke ring (1) and a plurality of stator teeth (2) uniformly arranged on the inner wall surface of the stator yoke ring (1) and surrounding the circumferential direction of the stator yoke ring (1), and a stator slot (3) is formed between two adjacent stator teeth (2), the stator slot (3) is 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 pole number of a rotor of a motor to which the stator lamination is applied, the number of the stator slots (3) in each slot group is even, the two stator slots (3) in the middle of each slot group 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 arranged on the two sides of the circumferential direction 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); a third auxiliary slot (11) is arranged on the outer wall surface of the stator yoke ring (1) corresponding to each slot group, circumferentially adjacent two 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 pole number 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), one side slot wall outer end point of the slot opening of the third auxiliary slot (11) is a first end point (111), and the other side slot wall outer end point is a second end point (112), the first end point (111) is located on the tooth symmetry line of the side stator tooth (22), and the central angle b of the first end point (111) and the second end point (112) with the center of the stator lamination as the vertex is b / a=0.11-0.

14.

2. The stator lamination of claim 1, wherein, The first auxiliary slot (211) is located in the region 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 that of the second auxiliary slot (212).

3. A stator lamination 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. A stator lamination according to claim 3, characterised in that The radial slot height of the second auxiliary slot (212) is Eh2, and the circumferential slot width is Ew2, Bh / Eh2=1.78-1.81, and Bw / Ew2=3.15-3.

25.

5. A stator lamination according to claim 4, characterised in that The first auxiliary slot (211) and the second auxiliary slot (212) are semicircular in shape, the center of the second auxiliary slot (212) is OE, the radial distance between the center of the second auxiliary slot (212) and the 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).

6. The stator lamination of claim 1, wherein, 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) is Dw, Fd / Dw=0.09~0.

1.

7. A stator lamination according to claim 6, characterised in that The third auxiliary slot (11) is a poor arc slot.

8. A stator core characterized by The stator core comprises a plurality of stator laminations according to any one of claims 1 to 7, the stator laminations are stacked along the axial direction, and the first auxiliary slot (211), the second auxiliary slot (212), and the third auxiliary slot (11) are axially positionally corresponding.

9. An electric machine characterized by The stator core comprises the stator core according to claim 8.

Images