Stator assembly, method for manufacturing stator assembly and flat wire motor

Abstract

The present application provides a stator assembly, a method for manufacturing a stator assembly, and a flat wire motor. The stator assembly includes an iron core, and a plurality of stator slots are sequentially arranged along the circumference of the iron core; along the radial direction of the iron core, a plurality of flat wires are stacked in each stator slot, and the flat wire is partially accommodated in the stator slot; insulating paper is also inserted in the stator slot to isolate the flat wire and the iron core, and the insulating paper has an expansion layer and an insulating layer, and the expansion layer is located on the side of the insulating layer facing the flat wire; at least one flat wire has a cooling groove for circulating a coolant, and the cooling groove is located on the side of the flat wire that is perpendicular to the radial direction of the iron core and does not contact the expansion layer; the intersection of adjacent side surfaces in the flat wire has a rounded corner, and adjacent rounded corners of adjacent flat wires enclose a rounded corner gap; the expansion layer can expand when heated to fill at least part of the gap between the side surface of the flat wire and the inner wall of the stator slot and the rounded corner gap, thereby reducing the probability of the expansion layer material of the insulating paper falling off and clogging the cooling groove.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and more specifically to a stator assembly, a method for manufacturing a stator assembly, and a flat wire motor. Background Art

[0002] In the flat wire motor, flat copper wire (also called flat wire) is wound around the stator core to form the stator assembly.

[0003] In order to achieve heat dissipation of the stator assembly, the prior art generally sets a cooling channel on the stator core or flat copper wire to remove heat through the flow of cooling medium. Among them, since the flat copper wire is the main heat source, compared with setting the cooling channel on the stator core, setting the cooling channel on the flat copper wire can make the cooling medium directly contact the heat source, and the heat dissipation effect is better.

[0004] In the related technical solutions, in order to enhance the insulation performance of the stator assembly, generally after the stator wire is embedded, paint is dripped on both ends of the winding to allow the insulating paint (also called insulating resin) to penetrate into the stator slots; or foamed insulating paper is arranged in the stator slots, and the insulating paper has a foaming layer, which can foam during the heating process to fill the gaps in the stator slots.

[0005] However, whether it is insulating varnish or foamed insulating layer, when it is applied to a flat wire with a cooling groove, there is a risk of clogging the cooling groove; and if the foamed layer contacts the coolant, there is a risk that the foamed material will fall off and enter the coolant circulation, which is undesirable in the art. In the above application, it is difficult to achieve a balance between the two goals of insulation and cooling. Summary of the invention

[0006] The purpose of the present application is to overcome or at least alleviate the deficiencies of the above-mentioned prior art, and to provide a stator assembly, a method for manufacturing a stator assembly and a flat wire motor to solve the problem of cooling grooves on the flat wire being blocked due to paint dripping from the stator assembly and / or the use of foamed insulating paper.

[0007] According to a first aspect of the present application, a stator assembly is provided, comprising an iron core, wherein a plurality of stator slots are sequentially arranged along the circumference of the iron core. In the radial direction of the iron core, a plurality of flat wires are stacked in each stator slot, and the flat wires are partially accommodated in the stator slots. Insulating paper is also inserted in the stator slots to isolate the flat wires from the iron core. The insulating paper has an expansion layer and an insulating layer, and the expansion layer is located on the side of the insulating layer facing the flat wire; at least one flat wire has a cooling groove for circulating a coolant, and the cooling groove is located on the side of the flat wire that is perpendicular to the radial direction of the iron core and does not contact the expansion layer. The intersection of adjacent side surfaces in the flat wire has a rounded corner, and adjacent rounded corners of adjacent flat wires enclose a rounded corner gap. The expansion layer can expand when heated to fill at least part of the gap between the side surface of the flat wire and the inner wall of the stator slot and the rounded corner gap.

[0008] According to a second aspect of the present application, a method for manufacturing the stator assembly according to the first aspect is provided, comprising the following steps:

[0009] S1, wind the insulating paper into a roll and insert it into the inner wall of the stator slot.

[0010] S2, embedding a plurality of flat wires in the reel in sequence.

[0011] S3, the insulating paper is heated, and the expansion layer expands due to the heat to fill the fillet gap.

[0012] According to a third aspect of the present application, a flat wire motor is provided, comprising a rotor assembly and the stator assembly of the first aspect.

[0013] The beneficial effects of one or more of the above technical solutions are:

[0014] In this solution, since the insulating paper has an insulating layer and an expansion layer, and the cooling groove is opened on the side of the flat wire that is perpendicular to the radial direction of the iron core and does not contact the expansion layer. This can prevent the refrigerant from directly contacting and impacting the expansion material, so as to prevent the expansion material from breaking into pieces and mixing into the refrigerant. Even if part of the coolant contacts the expansion layer through the gap between adjacent flat wires or the gap between the stator slot and the flat wire, the fallen material will be difficult to enter the cooling groove along the gap due to the small gap. That is, this solution can reduce the probability of the insulation paper expansion layer material falling off and clogging the cooling groove.

[0015] In this solution, the adjacent rounded corners of adjacent flat wires enclose a rounded corner gap, and the expansion layer can expand under heat to fill at least part of the gap between the side of the flat wire and the inner wall of the stator slot and the rounded corner gap. This allows the sides of the adjacent flat wires stacked and attached and the cooling slot and the inner wall of the stator slot to be blocked and isolated; on the one hand, the expansion layer that expands under heat can cooperate with the insulating paper to increase the insulation effect between the flat wire and the stator core. On the other hand, the insulating varnish dripped from the two ends of the stator slot along the axial direction of the core (that is, the two ends of the winding formed by the flat wire) will not enter the side of the flat wire or even the cooling slot along the rounded corner gap; that is, this solution can avoid the probability of insulating varnish blocking the cooling slot and ensure the smooth flow of the cooling channel.

[0016] In addition, there is magnetic field distortion inside the flat wire motor. Due to the effect of the air gap harmonic magnetic field, the flat wire in the stator slot is prone to large AC loss due to eddy current phenomenon. However, this solution can block the eddy current path by setting a cooling groove on the side of the flat wire perpendicular to the radial direction of the iron core, thereby reducing the AC loss of the flat wire and helping to reduce the heat generated by the flat wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the insulating paper before foaming in Example 1 of the present application;

[0018] Figure 2This is a schematic diagram of the insulating paper after foaming in Example 1 of the present application;

[0019] Figure 3 This is a schematic diagram of a structure of the flat wire located in the stator slot in Example 1 of the present application;

[0020] Figure 4 This is another schematic diagram of the structure of the flat wire located in the stator slot in Example 1 of the present application;

[0021] Figure 5 is a schematic diagram of a cross section of the iron core in Example 1 of the present application;

[0022] Figure 6 is a schematic diagram of the coordination between the stator assembly and the rotor assembly in Example 1 of the present application;

[0023] Figure 7 It is a schematic diagram of a cooling groove provided in one of the flat wires in Example 2 of the present application;

[0024] Figure 8 It is a schematic diagram of another flat wire with cooling grooves in Example 2 of the present application;

[0025] Fig. 9 is a schematic diagram showing that the insulating paper in Example 3 of the present application includes a first region and a second region;

[0026] Fig.10 is a schematic diagram of one of the flat wire structures in Example 3 of the present application after the insulating paper is foamed;

[0027] Fig.11 is a schematic diagram of another flat wire structure after the insulating paper is foamed in Example 3 of the present application;

[0028] Fig.12 It is a schematic diagram of the third flat wire structure in Example 3 of the present application after the insulating paper is foamed;

[0029] Fig.13 is a schematic diagram of the insulating paper including the third zone in Example 3 of the present application;

[0030] Fig.14 It is a schematic diagram of providing protrusions and cooling grooves at the flat wire in Example 4 of the present application;

[0031] Fig.15 It is a schematic cross-sectional view of the flat wire in Example 4 of the present application.

[0032] Figure numerals: 1, flat wire; 101, cooling groove; 102, protrusion; 103, third flow channel; 104, second flow channel; 105, first flow channel; 2, fillet gap; 3, insulating paper; 301, first zone; 302, second zone; 303, third zone; 5, stator slot; 6, iron core; 7, gap; 20, rotor assembly. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present application are described below with reference to 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.

[0034] The flat wire in this embodiment refers to a flat copper wire. In other embodiments, the flat wire can be a conductor made of other materials as long as it meets the use requirements. In this embodiment, for any stator slot, its length direction L coincides with the radial direction of the iron core; the width direction W of the stator slot is perpendicular to the length direction L of the iron core and the axial direction of the iron core. The two sides of the stator slot along the width direction are its left and right sides.

[0035] Example 1

[0036] Reference Figure 1-Figure 6 One or more embodiments of the present application provide a stator assembly, including an iron core 6, and a plurality of stator slots 5 are sequentially arranged along the circumference of the iron core 6. In the radial direction of the iron core 6, a plurality of flat wires 1 are stacked in each stator slot 5, and the flat wires 1 are partially accommodated in the stator slot 5. Insulating paper 3 is also inserted in the stator slot 5 to isolate the flat wires 1 from the iron core 6.

[0037] See also Figure 5 , which shows a schematic diagram of the end face of the iron core 6, the iron core 6 is roughly cylindrical, and the stator slots 5 penetrate the two end faces of the iron core 6 in a direction parallel to the axial direction of the iron core 6. The stator slots 5 are evenly arranged along the circumferential direction of the iron core 6, and one end of the stator slot 5 penetrates the inner circumferential surface of the iron core 6, so as to facilitate the insertion of the flat wire 1 from the opening of the stator slot 5 on the inner circumferential surface of the iron core 6. Optionally, the stator slots 5 can also be closed slots.

[0038] See also Figure 6 , each stator slot 5 has a plurality of flat wires 1, and the direction in which the plurality of flat wires 1 are stacked in sequence coincides with the radial direction of the core 6. It can be seen that, when there are a plurality of stator slots 5, the stacking directions of the flat wires 1 in different stator slots 5 are different, but they are respectively along the radial direction of the core 6. In addition, the extending direction of a single flat wire 1 in the stator slot 5 is parallel to the axial direction of the core 6.

[0039] See also Figure 1 , the insulating paper 3 is arranged around the inner wall of the stator slot 5. After the flat wires 1 in the stator slot 5 are placed, the insulating paper 3 surrounds the plurality of flat wires 1 and roughly forms a square tube shape. At this time, the extension direction of the tube-shaped insulating paper 3 is parallel to the axial direction of the iron core 6. After the insulating paper 3 is inserted around the stator slot 5, the two ends of the insulating paper 3 can overlap each other or directly abut and contact each other.

[0040] The insulating paper 3 has an expansion layer and an insulating layer, wherein the expansion layer is located on the side of the insulating layer facing the flat wire 1. Before the expansion layer of the insulating paper 3 is heated and expanded, there is a gap 7 between the insulating paper 3 and the inner wall of the stator slot 5 and the outer side of the flat wire 1.

[0041] It should be noted that the expansion layer and the insulating layer are both made of insulating materials, that is, the expansion layer also has an insulating function.

[0042] At least one of the flat wires 1 has a cooling groove 101 for circulating a coolant, and the cooling groove 101 is located on the side of the flat wire 1 perpendicular to the radial direction of the iron core 6 and not in contact with the expansion layer. The intersection of adjacent side surfaces of the flat wire 1 has a rounded corner, and adjacent rounded corners of adjacent flat wires 1 enclose a rounded corner gap 2. The expansion layer can expand under heat to fill at least part of the gap 7 between the side surface of the flat wire 1 and the inner wall of the stator slot 5 and the rounded corner gap 2.

[0043] In this embodiment, the cross section of the cooling groove 101 is a fixed cross section with a constant shape and size, and the cross section is a trapezoid. The opening size of the cooling groove 101 near the side of the flat wire 1 is larger than the inner wall size of the cooling groove 101 near the center of the flat wire 1. Here, the cooling groove 101 is only distributed in the portion of the flat wire 1 accommodated in the stator slot 5, and the other portions of the flat wire 1, especially the welding end used for welding, are not provided with the cooling groove 101, so as to facilitate the subsequent welding of the flat wire 1. In some other embodiments, the cooling groove 101 can be a square groove, a V-shaped groove, a U-shaped groove, a semicircular groove or other shapes, which can be set by those skilled in the art.

[0044] Specifically, the center line of the cooling groove 101 coincides with the center line of the flat wire 1 , thereby helping to ensure the cooling efficiency of the flat wire 1 .

[0045] In this embodiment, the cross section of a single flat wire 1 is rectangular, and multiple flat wires 1 are stacked in the stator slot 5 along the radial direction of the iron core 6. The cross-sectional shape of the stator slot 5 is also approximately rectangular. The shape of the stator slot 5 matches the shape of the multiple flat wires 1 after stacking. The size of the stator slot 5 is slightly larger than the size of the stacked flat wires 1, so as to facilitate the installation of the insulating paper 3 and the flat wire 1 in sequence. Specifically, the stator slot 5 also includes a reduced diameter section that is connected to the inner cavity of the stator core 6 and is not installed with the flat wire 1. The reduced diameter section can prevent the flat wire 1 from falling off along the radial direction of the iron core 6 and entering the inner cavity of the iron core 6.

[0046] For details, see again Figure 1The flat wire 1 has four sides, and a smoothly transitioned fillet is formed at the junction between each two sides. After the flat wires 1 are stacked on each other, two adjacent flat wires 1 form two fillet gaps 2 on the left and right sides along the width direction W of the stator slot 5. The fillet gap 2 here is formed by the two fillets of the adjacent flat wires 1 and the inner side of the insulating paper 3 facing the flat wire 1. Before the expansion layer of the insulating paper 3 is heated and expanded, the cooling groove 101 can be connected with the fillet gap 2 and the two ends of the stator slot 5 along the axial direction of the iron core 6 through the gap 7 when the adjacent flat wires 1 are attached. At this time, if the insulating paint liquid is dripped at both ends of the flat wire 1 winding (i.e., the two ends of the stator slot 5 along the axial direction of the iron core 6), the paint liquid may leak into the cooling groove 101 along the fillet gap 2 and cause the cooling groove 101 to be blocked.

[0047] See also Figure 2 In this embodiment, the expansion layer of the insulating paper 3 can expand under heat and block the fillet gap 2, thereby preventing the paint liquid from dripping from both ends of the flat wire 1 winding into the stator slot 5 from leaking into the cooling slot 101 from the fillet gap 2. It can be seen that when the expansion layer of the insulating paper 3 expands under heat to at least fill the gap 7 between the insulating paper 3 and the side of the flat wire 1, the expansion layer of the insulating paper 3 can stop the flat wire 1, so that the flat wire 1 is fixed in the stator slot 5, avoiding the shaking of the flat wire 1, and also avoiding the relative movement between two adjacent flat wires 1, which helps to reduce the NVH of the flat wire motor.

[0048] The cooling groove 101 mentioned above is arranged on the side of the flat wire 1 perpendicular to the axial direction of the iron core 6. When the flat wire motor is working, the closer to the rotor direction (that is, closer to the center direction of the iron core 6), the greater the AC loss of the flat wire 1. In this embodiment, the cooling groove 101 is arranged on the side of the flat wire 1 perpendicular to the axial direction of the iron core 6, which can block the eddy current path, thereby reducing the AC loss of the flat wire and helping to reduce the heat generated by the flat wire.

[0049] In this embodiment, in the same stator slot 5, except for the innermost flat wire and the outermost flat wire along the radial direction of the iron core 6, two side surfaces perpendicular to the radial direction of the iron core 6 in at least one flat wire 1 are respectively provided with cooling grooves 101, and the cooling grooves 101 respectively provided on the two side surfaces of the flat wire 1 are enclosed with the cooling grooves 101 of the adjacent flat wire 1 to form a second flow channel 104.

[0050] As a specific structural form, see Figure 1 Cooling grooves 101 are respectively provided on the sides of the flat wires 1 that abut against each other, and the cooling grooves 101 of adjacent flat wires 1 are butted against each other to enclose a second flow channel 104 .

[0051] In this embodiment, there are two types of flat wires 1 located in the same stator slot 5, namely Figure 3 The first type of flat wire shown in Figure 4 The second type of flat wire is shown in FIG. The first type of flat wire has only one side provided with a cooling groove 101, such as Figure 2 As shown, the first type of flat wire is installed at both ends of the stator slot 5 along the radial direction of the iron core 6. The second type of flat wire has two parallel sides each provided with a cooling groove 101. Figure 2 As shown, the second type flat wire located in the middle is provided with a cooling groove 101 on both sides along the radial direction of the iron core 6. Along the radial direction of the iron core, the cooling groove 101 on one side of a second type flat wire is enclosed with the cooling groove 101 of an adjacent flat wire 1 to form a second flow channel 104, and the cooling groove 101 on the other side is enclosed with the cooling groove 101 of another adjacent flat wire 1 to form a second flow channel 104. In the same stator slot 5, by arranging and combining the first type flat wire and the second type flat wire, the number of the second flow channels 104 in the stator slot 5 can be increased as much as possible while avoiding the cooling groove 101 from contacting the expansion layer of the insulating paper 3, thereby helping to increase the flow of the cooling medium and thus improve the heat exchange efficiency.

[0052] Specifically, the insulating layer and the expansion layer of the insulating paper 3 may be made of existing materials, which will not be described in detail here.

[0053] This embodiment also provides a method for manufacturing a stator assembly, comprising the following steps:

[0054] S1, winding the insulating paper 3 into a roll and inserting it into the stator slot 5. Specifically, here, two ends of the insulating paper 3 along the winding direction overlap each other.

[0055] S2, multiple flat wires 1 are sequentially embedded in the reel formed by the insulating paper 3. Specifically, each flat wire 1 includes two plug-in sections, each plug-in section is inserted into a different stator slot 5, and the crown end and the welding end (not shown in the figure) formed by bending in the flat wire 1 are located outside the stator core 6.

[0056] S3, heating the insulating paper 3, the expansion layer expands due to the heat to fill the fillet gap 2, and the expansion layer does not contact the cooling groove 101 of the flat wire 1. Specifically, the insulating paper 3 can be placed in a drying box with the entire stator assembly to increase the temperature, so that the expansion layer is heated and expands.

[0057] Optionally, after step S3 , the method for manufacturing the stator assembly further comprises: S4 , dripping insulating varnish at both axial ends of the iron core 6 , so that the insulating varnish seals the gap 7 between the inner wall of the stator slot 5 and the side surface of the flat wire 1 .

[0058] See also Figure 6 This embodiment further provides a flat wire motor, including a rotor assembly 20 and the stator assembly of the first aspect, wherein the rotor assembly 20 is embedded inside the stator assembly.

[0059] Example 2

[0060] The structural arrangement of this embodiment is basically the same as that of the embodiment 1, except that, in the same stator slot 5, the cooling slot 101 of at least one flat wire 1 is enclosed with the side of another adjacent flat wire 1 to form a first flow channel 105, and / or, the cooling slot 101 of at least one flat wire 1 is enclosed with the cooling slot 101 of another adjacent flat wire 1 to form a second flow channel 104. That is, in this embodiment, the type of flat wire 1 located in the same stator slot 5 includes only one type, namely Figure 3 The first type of flat wire is shown in FIG.

[0061] See also Figure 7 As one of the specific structural forms, the flat wire 1 that is the innermost from the center of the iron core 6 is the head flat wire, and a cooling groove 101 is set on the side of the head flat wire away from the center of the iron core 6. Except for the head flat wire 1, the cooling groove 101 is set on the side of the remaining flat wires 1 facing the center of the iron core 6. Figure 7 In the structural setting, most of the cooling grooves 101 are arranged on the radial inner side of the flat wire 1 along the core 6 and toward the center of the core 6, which can improve the efficiency of the cooling grooves 101 in blocking eddy currents. Figure 7 As shown, the cooling grooves 101 of the two flat wires 1 most inner from the center of the core 6 enclose a second flow channel 104 , and the remaining flat wires 1 and the side surfaces of another adjacent flat wire 1 enclose a first flow channel 105 .

[0062] See also Figure 8 As another specific structural form, the flat wire 1 farthest from the center of the iron core 6 is the end flat wire. A cooling groove 101 is set on the side of the end flat wire close to the center of the iron core 6, and cooling grooves 101 are set on the sides of the remaining flat wires 1 away from the center of the iron core 6. Figure 8 As shown, the cooling grooves 101 of the two flat wires 1 farthest from the center of the iron core 6 enclose a second flow channel 104 , and the remaining flat wires 1 and the side surfaces of another adjacent flat wire 1 enclose a first flow channel 105 .

[0063] In this embodiment, the cooling grooves 101 of each flat wire 1 are not directly facing the expansion layer of the insulating paper 3, so as to avoid the cooling grooves 101 being blocked by the expansion material. During the flow of the refrigerant, the refrigerant can also be prevented from impacting the expansion material and the expansion material fragments can be prevented from mixing into the refrigerant.

[0064] In this embodiment, by providing only one cooling slot 101 for all the flat wires 1 in the same stator slot 5, the cross-sectional area of ​​the flat wire 1 can be guaranteed, which is helpful to reduce the resistance of the flat wire 1, thereby helping to reduce the heat generated by the flat wire 1. In addition, the flat wires 1 in the same stator slot 5 are of the same type, which is helpful to reduce the manufacturing cost of the flat wire 1 and reduce the difficulty of manufacturing the flat wire motor.

[0065] Furthermore, by arranging the first type flat wires in the same stator slot 5, it is possible to prevent the cooling slot 101 from contacting the expansion layer of the insulating paper 3 while ensuring that the second flow channel 104 is formed in the stator slot 5, which helps to increase the flow rate of the refrigerant and improve the heat dissipation efficiency.

[0066] Specifically, in this embodiment, the side surfaces of the insulating paper 3 facing the flat wire 1 are covered with an expansion layer, so that the expansion layer can expand and fill the gap at any position between the insulating paper 3 and the flat wire 1 .

[0067] Example 3

[0068] The structural arrangement of this embodiment is basically the same as that of Embodiment 1, except that this embodiment provides an insulating paper 3 in which the expansion layer does not completely cover the insulating layer.

[0069] See also Figure 9-12 The insulating layer includes a plurality of first areas 301 and a plurality of second areas 302. The first areas 301 are covered with an expansion layer, while the second areas 302 are not covered with an expansion layer. After the insulating paper 3 and the flat wire 1 are inserted into the stator slot 5, the first area 301 at least covers the fillet gap 2, and at least one second area 302 directly faces the cooling slot 101. At this time, the second area 302 and the corresponding cooling slot 101 enclose a first flow channel 105. Fig. 9 As shown, it provides a schematic diagram of the unfolded insulating paper 3, where the first areas 301 and the second areas 302 are alternately arranged, and the second areas 302 are arranged on both sides of each first area 301.

[0070] That is to say, the insulating layer is used as the base layer, the first regions 301 are divided at intervals along the length direction of the insulating layer, and expansion layers are formed in the first regions 301 , and the insulating layer forms the second regions 302 in the regions between adjacent expansion layers.

[0071] In this embodiment, when the first area 301 and the second area 302 are arranged alternately, the opening of the cooling groove 101 faces the second area 302 where no expansion layer is provided in the insulating paper 3. This can prevent the cooling groove 101 from being blocked by the expansion material of the expansion layer, and prevent the cooling liquid in the cooling groove 101 from impacting the expansion layer and causing the fragments of the expansion layer to block the cooling groove 101.

[0072] As a specific structural form, see Fig.10 , the openings of all cooling slots 101 face away from the center of the core 6, and the opening of the cooling slot 101 farthest from the center of the core 6 faces the second area 302 of the insulating layer. In this case, the cooling slots 101 are all arranged on the side of the flat wire 1 away from the center of the core 6. Fig.10 As shown, there is only one type of flat wire 1 located in the same stator slot 5, namely Figure 3 The first type of flat wire is shown in FIG.

[0073] As another specific structural form, see Fig.11 , the openings of all cooling slots 101 face the direction close to the center of the core 6, and the opening of the cooling slot 101 closest to the center of the core 6 is directly opposite to the second zone 302 of the insulating layer. At this time, the cooling slots 101 are all arranged on the side of the flat wire 1 close to the center of the core 6. In the direction away from the rotor, the AC loss of the flat wire gradually decreases. By arranging the opening of the cooling slot 101 toward the center of the core 6, the success rate of blocking eddy current can be improved. Fig.11 As shown, there is only one type of flat wire 1 located in the same stator slot 5, namely Figure 3 The first type of flat wire is shown in FIG.

[0074] As a third specific structural setting, see Fig.12 , cooling grooves 101 are respectively arranged on two radial sides of the flat wire 1 perpendicular to the core 6, and the openings of the cooling groove 101 farthest from the core 6 and the cooling groove 101 closest to the core 6 are respectively opposite to the second area 302 of the insulating layer, and the cooling groove 101 and the second area 302 enclose a first flow channel 105. At this time, the cooling grooves 101 between two adjacent flat wires 1 enclose a second flow channel 104. Fig.12 As shown, there is only one type of flat wire 1 located in the same stator slot 5, namely Figure 4 The second type of flat wire is shown in FIG.

[0075] As another specific structural form, see Fig.13 The insulating layer also includes a third area 303, which is located between the first area 301 and the second area 302, that is, a third area 303 is provided on both sides of each first area 301. The third area 303 is provided with a non-expanding material, and the non-expanding material of the third area 303 acts as a barrier dam, so that in the process of the expansion layer of the first area 301 being heated and expanded, the expansion direction of the expansion material can be limited, and the expansion material can be prevented from expanding to the second area 302, which can further reduce the probability of the cooling groove 101 being blocked by the expanded expansion material. At the same time, the third area 303 will not directly face the cooling groove 101, which can prevent the non-expanding material of the third area 303 from directly contacting the refrigerant, thereby preventing the non-expanding material from entering the refrigerant.

[0076] Example 4

[0077] See also Figure 14-15 The structure of this embodiment is basically the same as that of the first embodiment, except that the flat wire 1 in this embodiment has a cooling groove 101 on one side along the radial direction of the iron core 6 and a protrusion 102 on the other side. The cooling grooves 101 on the two contacting sides of the adjacent flat wires 1 are connected to form a second flow channel 104, or are surrounded by the protrusions 102 to form a third flow channel 103.

[0078] The cooling grooves 101 and the protrusions 102 are staggered along the radial direction of the core 6, so that a single cooling groove 101, two cooling grooves 101 and two protrusions 102 can form cooling channels respectively, which can increase the number of cooling channels and help ensure the cooling effect.

[0079] Specifically, the cooling groove 101 and the protrusion 102 have the same size, which helps to ensure the cross-sectional area of ​​the flat wire, helps to reduce the resistance of the flat wire 1 , and thus helps to reduce the heat generated by the flat wire 1 .

[0080] Specifically, in this embodiment, the cooling groove 101 is located in the middle of the side of the flat wire 1 along the width direction of the stator slot 5, and the protrusion 102 is located at the edge of the side of the flat wire 1 along the width direction of the stator slot 5, which can ensure the aperture of the third flow channel 103 formed by the two protrusions 102.

[0081] It should be noted that, in this embodiment, the structure of the insulating paper can refer to that of embodiment 3, and the opening of the cooling groove 101 is not directly opposite to the expansion layer of the insulating paper. In this embodiment, only one type of flat wire is included in the same stator slot, and along the radial direction of the core, the cooling groove 101 of the innermost flat wire 1 and the second area 302 of the insulating paper 3 are enclosed to form a first flow channel 105, and the cooling groove 101 of the outermost flat wire 1 and the second area 302 of the insulating paper 3 are enclosed to form a first flow channel 105, and the remaining flat wires 1 are connected with adjacent flat wires 1 to form a second flow channel 104 and a third flow channel 103. While preventing the cooling groove 101 from contacting the expansion layer of the insulating paper 3, the number of flow channels in the stator slot 5 can be increased as much as possible, thereby helping to increase the flow rate of the cooling medium and thus improve the heat exchange efficiency.

[0082] In this embodiment, the volume of the cooling groove is equal to the volume of the protrusion.

[0083] Example 5

[0084] The structural arrangement of this embodiment is basically the same as that of the embodiment 1, except that, in the same stator slot 5, the width of the cooling slot in each flat wire decreases in sequence in the direction away from the center of the core. The width of the cooling slot refers to the dimension of the cooling slot along the left and right width direction of the stator slot after the flat wire is installed in the stator slot (the stator slot width direction has been defined in the beginning of the embodiment).

[0085] As another specific structural form, each flat wire has a plurality of cooling grooves, and the plurality of cooling grooves are connected by through holes. The refrigerant flowing from one cooling groove can flow to each cooling groove of the same flat wire, which helps to simplify the design of the refrigerant flow path and reduce the difficulty of design and manufacturing.

[0086] As another specific structural form, multiple cooling grooves are located on the same side of the flat wire, and the multiple cooling grooves on the same side are distributed in sequence along the middle of the flat wire to the left and right sides and their sizes gradually decrease. Specifically, the size of the cooling groove here refers to the size of the cooling groove along the left and right width direction of the stator slot, and the depth size of the cooling groove along the radial direction of the iron core.

[0087] As another specific structural form, in the same stator slot, the number of cooling slots at different flat wires decreases successively along the radial outward direction of the iron core.

[0088] Of course, the present invention is not limited to the above-mentioned embodiments. Those skilled in the art may make various combinations and modifications to the above-mentioned embodiments of the present invention under the guidance of the present invention without departing from the scope of the present invention.

Claims

1. A stator assembly, comprising an iron core, wherein a plurality of stator slots are sequentially arranged along the circumference of the iron core; a plurality of flat wires are stacked in each stator slot along the radial direction of the iron core, and the flat wires are partially accommodated in the stator slots; insulating paper is also inserted in the stator slots to isolate the flat wires from the iron core, wherein: The insulating paper has an expansion layer and an insulating layer, wherein the expansion layer is located on the side of the insulating layer facing the flat wire; at least one flat wire has a cooling groove for circulating a coolant, wherein the cooling groove is located on a side of the flat wire that is perpendicular to the radial direction of the iron core and does not contact the expansion layer; The intersections of adjacent side surfaces of the flat wire have rounded corners, and adjacent rounded corners of adjacent flat wires enclose a rounded corner gap; the expansion layer can expand under heat to fill at least part of the gap between the side surface of the flat wire and the inner wall of the stator slot and the rounded corner gap; In the same stator slot, except for the innermost and outermost flat wires in the radial direction of the core, at least one flat wire is provided with the cooling grooves on two sides perpendicular to the radial direction of the core, and the cooling grooves respectively provided on the two sides of the flat wire are enclosed with the cooling grooves of the flat wires adjacent to the sides to form a flow channel, and for the flat wires installed at both ends of the stator slot in the radial direction of the core, only one side is provided with a cooling groove; Alternatively, the insulating layer includes a plurality of first areas and a plurality of second areas, the expansion layer is disposed in the first area, the second area is not covered with the expansion layer, the first area at least covers the fillet gap, and the opening of the cooling groove faces the second area.

2. The stator assembly according to claim 1, characterized in that At least one of the cooling grooves and the second area are combined to form a first flow channel, and the cooling grooves respectively arranged on two side surfaces of the flat wire are combined with the cooling grooves of the flat wires adjacent to the side surfaces to form a second flow channel.

3. The stator assembly according to claim 1, characterized in that: In the same stator slot, the width of the cooling slot in each flat wire decreases successively in the direction away from the center of the iron core.

4. The stator assembly according to claim 1, characterized in that: At least one flat wire has a plurality of cooling grooves, and the plurality of cooling grooves are connected through through holes; And / or, in the same flat wire, the plurality of cooling grooves are located on the same side of the flat wire, and the plurality of cooling grooves are distributed sequentially from the middle of the flat wire to both sides and the sizes of the plurality of cooling grooves gradually decrease; And / or, in the same stator slot, the number of cooling slots at different flat wires decreases in sequence along the radial outward direction of the core.

5. The stator assembly according to claim 1, characterized in that The flat wire has a cooling groove on one side along the radial direction of the core and a protrusion on the other side; the cooling grooves on two contacting sides of adjacent flat wires are butted together to enclose a second flow channel, or the protrusions are used to enclose a third flow channel.

6. The stator assembly according to claim 5, characterized in that The cooling groove is located in the middle of the side surface of the flat wire, and the protrusion is located at the edge of the side surface of the flat wire; And / or, the volume of the cooling groove is equal to the volume of the protrusion.

7. A method for manufacturing a stator assembly, used for manufacturing the stator assembly according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, winding the insulating paper into a roll and inserting it into the stator slot; S2, embedding multiple flat wires in the reel in sequence; S3, the insulating paper is heated, and the expansion layer expands due to the heat to fill the fillet gap.

8. A flat wire motor, characterized in that: It comprises a rotor assembly and a stator assembly as claimed in any one of claims 1 to 6.

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