Motor stator and motor

Abstract

Provided is a motor stator. A core (1) of the motor stator is provided with a winding slot (11c). In the cross section of the motor stator, the winding slot (11c) has a first length direction (L1). Windings (2) of the motor stator each comprise an insertion portion (21) axially inserted into the winding slot (11c). The cross section of at least one insertion portion (21) has a long side extending in a second length direction (L2), and the long side is non-parallel and non-perpendicularly inclined relative to the first length direction (L1), so that an axially extending channel is defined between the wall of the winding slot (11c) and the insertion portion (21). In this way, the adverse effects on the magnetic flux path and stiffness of the stator caused by substantial changes in structure of the core in order to form an axial cooling flow passage are reduced, and the adverse effects on the installation of insulation paper caused by substantial changes in structure of the core in order to form the axial cooling flow passage are basically eliminated. Further provided is a motor comprising the motor stator.

Description

Motor stator and motor Technical Field

[0001] The present application relates to the field of motors, and in particular to a motor stator and a motor comprising the motor stator. Background Art

[0002] The peak current density of the drive motors used in modern all-electric vehicles is significantly higher than that of the transmission motors. Therefore, direct cooling of the drive motors (as opposed to indirect cooling using cooling jackets) is required to improve continuous operation. Among existing solutions for direct cooling of drive motors, slot cooling is a relatively effective approach. In this approach, a cooling fluid flows through the winding slots of the core, through which the flat conductors of the windings pass. To achieve this, the structure of the flat conductors or the walls of the winding slots are modified to create a flow path for the cooling fluid. For example, in some examples, a concave shape is formed in a portion of the sidewall of the winding slot, thereby forming the flow path between the flat conductors and this portion of the sidewall. In other examples, the radial dimension of the winding slot is increased to form the flow path between adjacent flat conductors.

[0003] However, existing solutions for direct cooling of drive motors require significant structural changes to the motor's stator core to create a fluid flow path. This necessitates a corresponding reduction in the size of the core's teeth and yoke, compressing the magnetic flux path and reducing core rigidity. Furthermore, these sometimes require the formation of raised or recessed features on the sidewalls of the winding slots, which adversely affects the installation of the insulating paper between the flat conductors and the core.

[0004] Summary of the Invention

[0005] This application is based on the shortcomings of the aforementioned prior art. One object of this application is to provide a motor stator that, with minimal or no changes to the stator's core structure, can form a flow path for cooling fluid within the core's winding slots. This not only reduces the adverse effects on the stator's magnetic flux path and stiffness, but also substantially eliminates the adverse effects on the installation of insulating paper. Another object of this application is to provide a motor including the aforementioned motor stator.

[0006] In order to achieve the above-mentioned purpose of the invention, this application adopts the following technical solutions.

[0007] The present application provides a motor stator as follows, comprising:

[0008] an iron core having a plurality of teeth spaced apart and distributed in a circumferential direction of the motor stator, wherein a winding slot is defined between every two adjacent teeth, and in any cross section of the motor stator perpendicular to its axial direction, the winding slot has a first length direction; and

[0009] The winding comprises an insertion portion inserted into the winding slot along the axial direction of the motor stator, wherein a cross section of at least one of the insertion portions has a long side extending along a second length direction, and the long side is inclined non-parallel and non-vertically relative to the first length direction, thereby defining a channel extending along the axial direction between the wall of the winding slot and the insertion portion.

[0010] In an optional solution, in the same winding groove, each of the insertion portions is configured such that the second longitudinal direction is inclined relative to the first longitudinal direction.

[0011] In another optional solution, in the same winding groove, each of the insertion portions is configured such that the second length direction forms the same angle with the first length direction, and the second length directions of all the insertion portions are parallel to each other.

[0012] In another optional scheme, in the cross-section, the cross-sectional shape of the at least one insertion portion is a rectangle, the length of the diagonal of the rectangle is greater than or equal to the width of the winding groove, and each of the at least one insertion portion has two opposite corners that abut against the side wall of the winding groove.

[0013] In another optional solution, in the cross section, the length of the long side of the rectangular shape is greater than the width of the winding groove.

[0014] In another optional solution, in the cross section, an extension direction of a diagonal line of the rectangular shape is perpendicular to the first length direction.

[0015] In another optional solution, insulating paper is further included, and the insulating paper is arranged between the wall of the winding groove and the insertion portion.

[0016] In another optional solution, in one of the winding slots, the insulating paper is arranged between at least two adjacent insertion parts among the plurality of insertion parts.

[0017] In another optional solution, the winding includes a plurality of card issuing units, each of which includes two inserting parts and a connecting part connecting the two inserting parts.

[0018] Each of the winding slots extends along the axial direction and a radial direction of the motor stator.

[0019] The present application also provides the following motor, comprising the motor stator described in any one of the above technical solutions.

[0020] By adopting the above technical solution, the present application provides a motor stator and a motor including the motor stator. In the motor stator of the present application, a portion of the winding is formed as an insertion portion inserted into the winding slot of the iron core. The motor stator has a cross-section perpendicular to its axial direction. For a winding slot, at least one insertion portion is constructed so that its long side is non-parallel and non-vertically inclined relative to the length direction of the winding slot in any cross-section, so that the long side of the rectangular shape of at least one insertion portion is also non-parallel and non-vertically inclined relative to the width direction of the winding slot, thereby defining an axially extending channel between the winding slot and the insertion portion. In this way, without substantially changing the structure of the iron core of the existing motor stator, an axial flow path for cooling fluid to flow through can be formed in the winding slot of the iron core using the above-mentioned channel, which not only reduces the adverse effects on the magnetic flux path and stiffness of the stator caused by the significant changes in the structure of the iron core to form the flow path, but also substantially eliminates the adverse effects on the installation of insulating paper caused by the significant changes in the structure of the iron core to form the flow path. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1A shows a schematic cross-sectional view of a motor stator according to a first embodiment of the present application, in which hatching is omitted.

[0022] FIG. 1B is an enlarged schematic diagram showing a part of the structure in FIG. 1A .

[0023] FIG. 2A is a perspective schematic diagram showing windings of the stator of the motor in FIG. 1A .

[0024] FIG. 2B is a schematic perspective view showing a cross section of the winding in FIG. 2A , in which hatching is omitted.

[0025] FIG. 2C is a schematic cross-sectional view showing the winding in FIG. 2A , in which hatching is omitted.

[0026] FIG3 is an enlarged schematic diagram showing a partial structure of a motor stator according to a second embodiment of the present application.

[0027] Description of Reference Numerals

[0028] 1 iron core; 11 tooth portion; 11c winding groove; 12 yoke portion; L1 first length direction; W1 first width direction;

[0029] 2 winding; 21 insertion portion; 22 connection portion; 23 twisted end portion; L2 second length direction; W2 second width direction;

[0030] 3. Insulation paper;

[0031] 4-slot wedge. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0033] It should be noted that, unless otherwise specified, in this application, "axial", "radial" and "circumferential" refer to the axial, radial and circumferential directions of the motor stator (iron core), respectively. "Cross-section" refers to the cross-section of the motor stator perpendicular to its axial direction. "First length direction" and "first width direction" refer to the length direction and width direction of the winding slot of the iron core in the cross-section, respectively. "Second length direction" and "second width direction" refer to the length direction and width direction of the insertion part of the winding (or hairpin unit) in the cross-section.

[0034] The motor stator according to the first embodiment of the present application will be described below with reference to the accompanying drawings.

[0035] (Motor stator according to the first embodiment of the present application)

[0036] As shown in FIG. 1A and FIG. 1B , the motor stator according to the first embodiment of the present application includes an iron core 1 , a winding 2 , insulating paper 3 , and slot wedges 4 that are assembled together.

[0037] In this embodiment, as shown in Figures 1A and 1B, the core 1 includes a plurality of teeth 11 and a yoke 12. The yoke 12 extends continuously along the entire circumference. A plurality of teeth 11 protrude radially inward from the yoke 12 and are evenly distributed at intervals in the circumferential direction, and each tooth 11 has the same shape and size. A winding groove 11c is defined between each two circumferentially adjacent teeth 11, the yoke 12 forms the bottom wall of the winding groove 11c, and the teeth 11 form the side walls of the winding groove 11c, and the bottom wall and the side walls together constitute the walls of the winding groove 11c. Since the plurality of teeth 11 are evenly distributed in the circumferential direction, the plurality of winding grooves 11c are also evenly distributed in the circumferential direction. In addition, each winding groove 11c extends in the axial direction and in a radial direction, and each winding groove 11c has a radial opening open toward the radial inside and an axial opening open toward both sides of the axial direction. In any cross-section taken at any position along its entire axial length, the winding groove 11c has a uniform cross-sectional shape, which is a rectangle (including a substantially rectangular shape). The winding groove 11c has a first longitudinal direction L1 that is aligned with a corresponding radial direction and a first width direction W1 that is perpendicular to the first longitudinal direction L1. Furthermore, as shown in FIG1B , the portion of each tooth 11 located at the radial opening of the winding groove 11c forms a dovetail shape. Thus, the dovetail shapes of adjacent teeth 11 form abutment portions for contact with the corresponding slot wedges 4.

[0038] In this embodiment, as shown in Figures 1A to 2C, the winding 2 is made of a flat conductor and includes multiple hairpin units. Each hairpin unit includes two insertion portions 21, each inserted into a different winding slot 11c, and a connecting portion 22 connecting the two insertion portions 21. Furthermore, the hairpin unit includes a twisting end 23 located at the other end of the insertion portion 21 away from the connecting portion 22. The twisting end 23 is twisted by a tool to a predetermined angle relative to the insertion portion 21.

[0039] As shown in Figures 1A and 1B, in each winding slot 11c, a plurality of inserts 21 are provided that are inserted along the axial direction. In each winding slot 11c, the plurality of inserts 21 are stacked in a radial direction R corresponding to the winding slot 11c. In a cross-section taken at any position along the entire axial length, the inserts 21 have the same cross-sectional shape, which is a rectangular shape (including a substantially rectangular shape, for example, the cross-section of the insert 21 can be a rectangle with rounded corners), and the cross-sectional shape of different inserts 21 is also the same. Furthermore, the rectangular shape has a second longitudinal direction L2 and a second width direction W2 perpendicular to the second longitudinal direction L2. In each winding slot 11c, each of the plurality of inserts 21 is configured such that the second longitudinal direction L2 is non-parallel and non-perpendicular to the first longitudinal direction L1. In the same winding slot 11c, all inserts 21 are configured such that the second longitudinal direction L2 forms the same angle with the first longitudinal direction L1, so that the second longitudinal directions L2 of all inserts 21 are parallel to each other. Specifically, in cross-section, a diagonal line of the rectangular shape of the insert 21 extends in the same direction as the first width direction W2, and the length of the diagonal line is equal to the width of the winding slot 11c in the first width direction W. As a result, the two opposing corners of each insert 21 abut against the side walls of the winding slot 11c. Furthermore, after installation, as shown in FIG1B , a corner of the radially outermost insert 21 abuts against the bottom wall of the winding slot 11c, a corner of the radially innermost insert 21 abuts against the slot wedge 4, and every two adjacent inserts 21 abut against each other (including those abutting against each other through insulating paper). In this way, the side walls of the winding slot 11c limit all inserts 21 in the first width direction W1, the bottom wall of the winding slot 11c and the slot wedge 4 limit all inserts 21 in the first length direction L1, and an axially extending channel is defined between the walls (bottom and side walls) of the winding slot 11c and the insert 21. The above-mentioned channel can constitute a flow path for the cooling fluid to flow through.

[0040] In this embodiment, as shown in FIG1B , the insulating paper 3 includes a portion that adheres to the wall of the winding slot 11 c and a portion that extends between adjacent insertion portions 21. The portion of the insulating paper 3 located between the plurality of insertion portions 21 and the core 1 serves as supplementary insulation (secondary insulation) between the insertion portions 21 and the core 1. The portion of the insulating paper 3 located between adjacent insertion portions 21 serves as supplementary insulation between adjacent insertion portions 21.

[0041] In this embodiment, as shown in FIG. 1B , the slot wedge 4 is inserted into the winding groove 11 c along the axial direction and overlaps the abutment portion formed on the tooth portion 11 , thereby closing the radial opening of the winding groove 11 c and preventing the insertion portion 21 from escaping from the winding groove 11 c.

[0042] Thus, in the technical solution of the present application, there is no need to use a special-shaped conductor or form an additional flow path in the iron core 1. The flow path for the cooling fluid to flow can be formed by utilizing the existing conductor with a rectangular cross-section and conventional winding slots 11c. In other words, in the present application, without substantially changing the structure of the iron core 1 of the existing motor stator, the flow path for the cooling fluid to flow can be formed by utilizing the above-mentioned channels in the winding slots 11c of the iron core 1. This not only reduces the adverse effects on the magnetic flux path and stiffness of the stator caused by the significant structural changes to the iron core 1 to form the flow path, but also substantially eliminates the adverse effects on the installation of the insulating paper 3 caused by the significant structural changes to the iron core 1 to form the flow path.

[0043] The motor stator according to the second embodiment of the present application will be described below with reference to the accompanying drawings.

[0044] (Motor stator according to the second embodiment of the present application)

[0045] The motor stator according to the second embodiment of the present application has substantially the same structure as the motor stator according to the first embodiment of the present application, and the differences between the two are mainly described below.

[0046] Since the channel formed between the insert portion 21 and the wall of the winding groove 11c serves as a flow path for the cooling fluid, the size of the cross-sectional area of ​​the flow path will affect the flow resistance of the cooling fluid in the flow path. Compared with the first embodiment, in this embodiment, as shown in Figure 3, the acute angle formed by the second length direction L2 and the first length direction L1 is larger, and thus the cross-sectional area of ​​the channel formed between the insert portion 21 and the wall of the winding groove 11c is smaller, which increases the flow resistance of the cooling fluid and reduces the flow rate of the cooling fluid. However, this can reduce the length of the winding groove 11c, thereby correspondingly increasing the size of the yoke 12. Furthermore, in this embodiment, no insulating paper 3 is provided between adjacent insert portions 21.

[0047] The present application is not limited to the solutions described in the above embodiments, and those skilled in the art can make various modifications to the above embodiments of the present application under the guidance of the present application without departing from the scope of the present application. The following is a supplementary explanation of the technical solution of the present application.

[0048] i. The present application provides a motor comprising a motor rotor and the motor stator described in the above embodiments. The motor rotor may be located radially inward of the motor stator with a certain air gap therebetween. The motor rotor is capable of rotating relative to the motor stator, thereby outputting torque to the exterior of the motor or receiving torque from the exterior of the motor.

[0049] ii. In the above embodiments, in the same winding groove 11c, each insertion portion 21 is tilted in such a manner that its second length direction L2 is at the same angle relative to the first length direction L1, but the present application is not limited thereto. For example, in an optional scheme, a portion of the insertion portions 21 are tilted in such a manner that their second length direction L2 is at the same angle relative to the first length direction L1, and another portion of the insertion portions 21 are perpendicular to the first length direction L1 with their second length direction L2. In another optional scheme, in the same winding groove 11c, the second length direction L2 of each insertion portion 21 is tilted relative to the first length direction L1, but these insertion portions 21 are tilted at different angles. Further, it can be understood that in different winding grooves 11c, the arrangement of the insertion portions 21 in the winding groove 11c can be flexibly adjusted as needed.

[0050] In addition, in the above embodiment, the length of the diagonal of the cross-section of the insertion portion 21 is equal to the width of the winding groove 11c, but the present application is not limited to this. For example, in one optional solution, the length of the diagonal of the rectangular cross-section of the insertion portion 21 is greater than the width of the winding groove 11c. In another optional solution, the length of the long side of the rectangular cross-section of the insertion portion 21 is greater than the width of the winding groove 11c, thereby preventing the insertion portion 21 from undesirably flattening (flattening here means that the first length direction L1 is perpendicular to the second length direction L2).

[0051] iii. It can be understood that after the slot wedge 4 is inserted and installed in the winding slot 11 c , the slot wedge 4 is pressed against the abutting portion by the force of the insertion portion 21 , so that the slot wedge 4 does not produce undesirable movement.

[0052] iv. The length direction of the winding slot 11 c does not have to be consistent with a radial direction of the motor stator. In a possible embodiment, the length direction of the winding slot 11 c can be inclined relative to the radial direction of the motor stator at the winding slot 11 c.

[0053] v. As described above, in one example, the side walls and the bottom wall (the wall opposite to the radial opening of the winding groove) of the winding groove may be planar without protrusions or depressions.

[0054] vi. The motor of the present application is not limited to an inner rotor motor, but may also be an outer rotor motor.

Claims

1. A motor stator, comprising: a core (1) having a plurality of tooth portions (11) spaced apart circumferentially of the motor stator, and a winding slot (11c) defined between every two adjacent tooth portions (11). In any cross-section of the motor stator perpendicular to its axial direction, the winding slot (11c) has a first length direction (L1); and a winding (2) including an insertion portion (21) inserted into the winding slot (11c) along the axial direction of the motor stator. The cross-section of at least one insertion portion (21) has a long side extending along a second length direction (L2), and the long side is inclined non-parallel and non-perpendicular to the first length direction (L1), thereby defining a channel extending along the axial direction between the wall of the winding slot (11c) and the insertion portion (21).

2. The motor stator according to claim 1, wherein, in the same winding slot (11c), each insertion portion (21) is configured such that the second length direction (L2) is inclined with respect to the first length direction (L1).

3. The motor stator according to claim 2, wherein, in the same winding slot (11c), each insertion portion (21) is configured such that the angle formed by the second length direction (L2) and the first length direction (L1) is the same, and the second length directions (L2) of all the insertion portions (21) are parallel to each other.

4. The motor stator according to any one of claims 1 to 3, wherein, in the cross-section, the cross-sectional shape of the at least one insertion portion (21) is a rectangular shape, the length of the diagonal of the rectangular shape is greater than or equal to the width of the winding slot (11c), and two opposite corner portions of each insertion portion (21) in the at least one insertion portion (21) abut against the side wall of the winding slot (11c).

5. The motor stator according to claim 4, wherein, in the cross-section, the length of the long side of the rectangular shape is greater than the width of the winding slot (11c).

6. The motor stator according to claim 4, wherein, in the cross-section, the extending direction of one diagonal of the rectangular shape is perpendicular to the first length direction (L1).

7. The motor stator according to any one of claims 1 to 4, wherein, it further includes an insulating paper (3), and the insulating paper (3) is disposed between the wall of the winding slot (11c) and the insertion portion (21).

8. The motor stator according to claim 7, wherein, in one winding slot (11c), the insulating paper (3) is disposed between at least two adjacent insertion portions (21) among the plurality of insertion portions (21).

9. The motor stator according to any one of claims 1 to 4, wherein, the winding (2) includes a plurality of hairpin units, and each hairpin unit includes two insertion portions (21) and a connecting portion (22) connecting the two insertion portions (21), Each of the winding grooves (11c) extends along the axial direction and a radial direction of the motor stator.

10. A motor, comprising the motor stator according to any one of claims 1 to 9.

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