Stator core, stator assembly, motor, power assembly and vehicle

Abstract

The invention discloses a stator core, a stator assembly, a motor, a power assembly and a vehicle, and the stator core comprises a first iron core section, the peripheral surface of the first iron core section is provided with a plurality of cooling flow channels, the plurality of cooling flow channels are arranged at intervals in the circumferential direction of the first iron core section, and the cooling flow channels penetrate through the first iron core section in the axial direction of the first iron core section; the second iron core section is arranged on one axial side of the first iron core section, the second iron core section is provided with a plurality of hole groups arranged at intervals in the circumferential direction, the plurality of hole groups communicate with the plurality of cooling flow channels in a one-to-one correspondence mode, the hole groups comprise cooling holes, and the cooling holes of the same hole group communicate with the corresponding cooling flow channels; and the through-flow area of the cooling hole is smaller than that of the cooling flow channel. According to the stator core provided by the embodiment of the invention, the first iron core section and the second iron core section are arranged, and the through-flow area of the cooling hole is smaller than the through-flow area of the cooling flow channel, so that the cooling range can be increased, an oil injection ring can be omitted, and the structural compactness can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and more specifically, to a stator core, a stator assembly, a motor, a powertrain, and a vehicle. Background Art

[0002] As one of the core components for power output of electric vehicles, motors are required to have high power density, high torque density, high system efficiency, as well as lightweight, low cost, and better mass production processability, etc., so as to meet users' requirements for high performance and low cost of electric and hybrid vehicles.

[0003] During the operation of the motor, due to the harsh working environment, high ambient temperature, and large heat generated by the motor during operation, the motor needs to be cooled to meet the heat dissipation requirements of the motor. In the related art, the cooling structure of the motor is relatively bulky, occupies a large space, and has a poor cooling effect, making it difficult to meet the heat dissipation requirements of the motor. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, an object of the present invention is to provide a stator core, which has a cooling structure, is beneficial to eliminating additional cooling structures such as an oil injection ring, making the structure of the motor more compact, and having a better cooling effect, which is conducive to meeting the heat dissipation requirements.

[0005] Another object of the present invention is to provide a motor having the above stator core.

[0006] Another object of the present invention is to provide a powertrain having the above motor.

[0007] Another object of the present invention is to provide a vehicle having the above powertrain.

[0008] The stator core according to an embodiment of the present invention includes: a first core segment, on the outer peripheral surface of which a plurality of cooling channels are provided, the plurality of cooling channels are arranged at intervals along the circumferential direction of the first core segment, and the cooling channels axially penetrate through the first core segment along the axial direction of the first core segment; a second core segment, provided on one axial side of the first core segment, the second core segment is provided with a plurality of hole groups arranged at intervals along the circumferential direction, the plurality of hole groups are in one-to-one correspondence and communication with the plurality of cooling channels, each hole group includes cooling holes, the cooling holes in the same hole group are all in communication with the corresponding cooling channel, and the flow area of the cooling holes is smaller than the flow area of the cooling channels.

[0009] According to the stator core of an embodiment of the present invention, by providing a first core segment and a second core segment, a plurality of cooling channels of the first core segment are in one-to-one correspondence and communicated with a plurality of hole groups of the second core segment and are arranged at intervals along the circumferential direction of the stator core, which is beneficial to uniformly cool the stator core and the stator winding circumferentially, making the stator core and the stator winding dissipate heat evenly. Moreover, the flow area of the cooling holes is smaller than the flow area of the cooling channels, enabling the cooling medium to spray out from the cooling holes to cool the stator winding, which is beneficial to increasing the coverage range and spraying distance of the cooling medium, having a better cooling effect on the stator winding. At the same time, it is beneficial to eliminate the oil injection ring, reduce the number of required components, and improve the structural compactness.

[0010] In addition, the stator core according to the above embodiment of the present invention may further have the following additional technical features:

[0011] According to some embodiments of the present invention, the hole group includes a plurality of the cooling holes, and at least two of the plurality of cooling holes are arranged at intervals along the radial direction of the second core segment.

[0012] According to some embodiments of the present invention, at least two of the plurality of cooling holes are arranged at intervals along the circumferential direction of the second core segment.

[0013] According to some embodiments of the present invention, there are two second core segments, and the two second core segments are respectively arranged on the axial two sides of the first core segment.

[0014] According to some embodiments of the present invention, the cooling channel includes a plurality of grooves arranged at intervals along the circumferential direction, the depth of the groove along the radial direction of the first core segment is a, the outer peripheral surface radius of the stator core is R out and the inner peripheral surface radius is also R in , the thickness of the yoke portion of the stator core along the radial direction is L, and the axial length of the stator core is h, where 0.05 ≤ k1 ≤ 0.1.

[0015] According to some embodiments of the present invention, the stator core further includes: a third core segment, the third core segment is axially located between the second core segment and the first core segment, and the third core segment is provided with a plurality of communication channels corresponding to the plurality of cooling channels, and the communication channels communicate the cooling channels and the corresponding hole groups.

[0016] According to some embodiments of the present invention, at least one of the cooling holes is provided in the yoke portion of the second core segment; at least one of the cooling holes is provided in the tooth portion of the second core segment.

[0017] According to some embodiments of the present invention, at least one of the cooling holes communicates with the tooth slot of the second core segment.

[0018] According to some embodiments of the present invention, multiple cooling holes in the same hole group include multiple first cooling holes, and the multiple first cooling holes are arranged at intervals along the circumferential direction of the second iron core segment; the communication channel includes a first channel, the first channel extends continuously along the circumferential direction of the third iron core segment, the first cooling hole and the first channel are axially opposite and communicated with each other, and the cooling flow channel and the first channel are axially opposite and communicated with each other.

[0019] According to some embodiments of the present invention, the depth of the first channel along the radial direction of the third iron core segment is c, the radius of the outer peripheral surface of the stator iron core is R ou t and the radius of the inner peripheral surface is R in , the thickness of the yoke portion of the stator iron core along the radial direction is L, the axial length of the stator iron core is h, wherein, 0.045 ≤ k2 ≤ 0.12.

[0020] According to some embodiments of the present invention, the cooling flow channel includes multiple grooves arranged at intervals along the circumferential direction, the depth of the groove along the radial direction of the first iron core segment is a, the dimension of the groove along the circumferential direction of the first iron core segment is b, the depth of the first channel along the radial direction of the third iron core segment is c, and the dimension of the first channel along the circumferential direction of the third iron core segment is d, wherein, d = k3 × (2a + b) - 2c, 2.4 ≤ k3 ≤ 8.

[0021] According to some embodiments of the present invention, multiple cooling holes in the same hole group further include multiple second cooling holes, the second cooling holes are located radially inside the first cooling holes, and the multiple second cooling holes are arranged at intervals along the radial direction of the second iron core segment; the communication channel includes a second channel, the second channel extends continuously along the radial direction of the third iron core segment, and the radially outer end of the second channel is connected to the radially inner side of the first channel, and the second cooling hole and the second channel are axially opposite and communicated with each other.

[0022] According to some embodiments of the present invention, the flow area of the second channel is S, the depth of the first channel along the radial direction of the third iron core segment is c, and the dimension of the first channel along the circumferential direction of the third iron core segment is d, wherein, S = k4 × (c × d), 0.75 ≤ k4 ≤ 1.75.

[0023] The stator assembly according to an embodiment of the present invention includes a stator iron core according to an embodiment of the present invention.

[0024] The motor according to an embodiment of the present invention includes a stator assembly according to an embodiment of the present invention.

[0025] The powertrain according to an embodiment of the present invention includes a motor according to an embodiment of the present invention.

[0026] A vehicle according to an embodiment of the present invention includes a powertrain according to an embodiment of the present invention.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 is a cross-sectional view of an electric machine according to an embodiment of the present invention;

[0030] Figure 2 is Figure 1 a partial enlarged view of the area marked A in

[0031] Figure 3 is a schematic structural view of a second iron core segment according to an embodiment of the present invention;

[0032] Figure 4 is a schematic structural view of a stator assembly according to an embodiment of the present invention;

[0033] Figure 5 is a schematic structural view of a stator iron core according to an embodiment of the present invention;

[0034] Figure 6 is a schematic structural view of a first iron core segment according to an embodiment of the present invention;

[0035] Figure 7 is a curve graph showing the change of the pressure drop of the cooling medium and the temperature rise of the electric machine with respect to k1 according to an embodiment of the present invention;

[0036] Figure 8 is a schematic structural view of a third iron core segment according to an embodiment of the present invention;

[0037] Figure 9 is a schematic structural view of a third iron core segment according to a second embodiment of the present invention;

[0038] Figure 10 is a schematic structural view of a second iron core segment according to a second embodiment of the present invention;

[0039] Figure 11 is a curve graph showing the change of the year-on-year increase of the pressure drop of the cooling medium and the year-on-year decrease of the convective heat transfer coefficient with respect to k2 according to an embodiment of the present invention;

[0040] Figure 12 is a curve graph showing the change of the year-on-year increase of the pressure drop of the cooling medium and the year-on-year decrease of the convective heat transfer coefficient with respect to k3 according to an embodiment of the present invention;

[0041] Figure 13 It is a curve graph showing the year-on-year increase in the pressure drop of the cooling medium and the year-on-year increase in the flow rate of the cooling medium varying with k4 according to an embodiment of the present invention;

[0042] Figure 14 It is a schematic diagram of a vehicle according to an embodiment of the present invention.

[0043] Reference numerals:

[0044] Vehicle 1000; powertrain 400; motor 300; housing 301; liquid inlet 302; liquid inlet channel 303; communication port 304; internal cavity 305; annular diversion cavity 306;

[0045] Stator assembly 200; stator winding 201; outer-slot part 202; stator core 100;

[0046] First core segment 10; cooling flow channel 11; groove 111;

[0047] Second core segment 20; hole group 21; first cooling hole 211; second cooling hole 212; cooling hole 213;

[0048] Third core segment 30; communication channel 31; first channel 311; second channel 312;

[0049] Yoke part 40; tooth part 50; tooth slot 51. Detailed implementation manners

[0050] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0051] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0052] In the description of the present invention, the "first feature" and the "second feature" may include one or more of such features. The meaning of "multiple" is two or more. The first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. The first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature has a higher horizontal height than the second feature.

[0053] The motor 300 according to an embodiment of the present invention will be described below with reference to the drawings.

[0054] Refer to Figures 1 - 13 As shown, the motor 300 according to an embodiment of the present invention may include a stator assembly 200 according to an embodiment of the present invention. The stator assembly 200 according to an embodiment of the present invention may include a stator core 100 according to an embodiment of the present invention. The stator core 100 according to an embodiment of the present invention may include a first core segment 10 and a second core segment 20.

[0055] In some embodiments, the motor 300 further includes a housing 301, a rotor assembly, etc.

[0056] In some embodiments, the stator assembly 200 further includes a stator winding 201.

[0057] The stator core 100 includes a combination of the first core segment 10 and the second core segment 20. The first core segment 10 may be an integral part or formed by stacking stator punching sheets. The second core segment 20 may be an integral part or formed by stacking stator punching sheets. The stator punching sheets may be silicon steel sheets. In some embodiments, as Figure 4 shown, the first core segment 10 is formed by stacking stator punching sheets, and the second core segment 20 includes a single stator punching sheet.

[0058] Specifically, a plurality of cooling channels 11 are provided on the outer peripheral surface of the first core segment 10. The plurality of cooling channels 11 are arranged at intervals along the circumferential direction of the first core segment 10, and the cooling channels 11 penetrate the first core segment 10 axially along the first core segment 10.

[0059] The cooling channels 11 may extend axially along the stator core 100, or may extend in a direction at an angle to the axial direction of the stator core 100, or the cooling channels 11 may extend along a curve or a broken line, etc.

[0060] The cooling channels 11 can be used to circulate a cooling medium to cool the first iron core segment 10, improve the heat dissipation performance of the first iron core, and further improve the heat dissipation performance of the motor 300, which is beneficial to maintaining the normal operation of the motor 300. The cooling medium can be cooling oil with a relatively low temperature, etc. For example, in some embodiments, the cooling medium is cooling oil with a relatively low temperature. The cooling oil can not only cool the first iron core segment 10, but also lubricate the stator iron core 100, the stator assembly 200 and other components of the motor 300, improving the working performance of the motor 300.

[0061] By providing a plurality of cooling channels 11 on the outer peripheral surface of the first iron core segment 10, the flow of the cooling medium flowing on the outer peripheral surface of the first iron core segment 10 can be changed from laminar flow to turbulent flow, which is beneficial to increasing the heat dissipation area of the outer peripheral surface of the first iron core segment 10 radially inward, accelerating the flow rate of the cooling medium, improving the heat dissipation performance of the first iron core segment 10, and improving the heat dissipation performance of the motor 300.

[0062] The second iron core segment 20 is provided on one axial side of the first iron core segment 10. The second iron core segment 20 is provided with a plurality of hole groups 21 arranged at intervals in the circumferential direction. The plurality of hole groups 21 are in one-to-one correspondence and communication with the plurality of cooling channels 11. Each hole group 21 includes cooling holes 213. The cooling holes 213 of the same hole group 21 are all in communication with the corresponding cooling channel 11, and the flow-through area of the cooling holes 213 is smaller than the flow-through area of the cooling channel 11. Here, the "flow-through area" refers to the area of the cross-section perpendicular to the axis of the stator iron core 100.

[0063] The cooling medium flowing out of the cooling channel 11 can flow to the cooling holes 213 to cool the second iron core segment 20 and spray out from the cooling holes 213 to the outside of the stator iron core 100. The flow-through area of the cooling holes 213 is smaller than the flow-through area of the cooling channel 11, so that when the cooling medium flows through the cooling holes 213 and sprays out from the cooling channel 11, a certain spraying pressure is generated, forming a spray shape, so as to increase the coverage range of the cooling medium in the axial and radial directions, increase the spraying distance of the cooling medium in the axial and radial directions, so as to fully cool the parts 202 of the stator winding 201 outside the slots on both axial sides of the stator iron core 100, which is beneficial to increasing the cooling range of the cooling medium and improving the cooling efficiency of the motor 300.

[0064] The plurality of cooling channels 11 and the plurality of hole groups 21 are arranged at intervals in the circumferential direction of the stator iron core 100, which is beneficial to uniformly cooling the stator iron core 100 and the stator winding 201 in the circumferential direction, making the heat dissipation of the stator iron core 100 uniform, reducing the possibility of overheating and burning of some parts of the stator iron core 100, and improving the working reliability of the stator iron core 100.

[0065] After the cooling medium enters the cooling channel 11, it flows in the cooling channel 11 and flows towards the cooling hole 213 to cool the first iron core segment 10 and the second iron core segment 20. The cooling medium in the cooling hole 213 can be sprayed into the inner cavity 305 of the motor 300 to spray onto the outer part 202 of the stator winding 201 outside the slot, cooling the stator winding 201 and improving the heat dissipation performance of the motor 300.

[0066] Moreover, after the cooling medium is sprayed onto the upper outer surface of the outer part 202 of the slot, it can flow from the outer surface of the outer part 202 to the inner surface and then to the lower outer surface under the action of gravity and the injection force, so as to increase the cooling area of the cooling medium for the outer part 202 of the slot, improve the heat dissipation uniformity of the outer and inner surfaces of the stator winding 201, and improve the heat dissipation efficiency and heat dissipation effect of the stator winding 201.

[0067] In addition, in the related art, by arranging an oil injection ring at one axial end of the stator core inside the motor housing, part of the cooling medium flows to the stator core for cooling, and the other part of the cooling medium is sprayed radially inward from the spray holes of the oil injection ring to the outer part of the stator winding outside the slot. The stator core and the outer part of the slot are respectively allocated part of the cooling medium, and the cooling medium allocated to the stator core is less, resulting in a poor cooling effect on the stator core and the stator winding, and a poor heat dissipation performance of the motor.

[0068] At the same time, the cooling medium allocated to the stator core flows to the top of the stator core and flows along the outer peripheral surface of the stator core to the bottom under the action of gravity. The flowing cooling medium is difficult to cover all areas of the outer peripheral surface of the stator core, and the flowing speed is low, resulting in a poor cooling effect. Moreover, the cooling medium allocated to the outer part of the slot needs to be sprayed onto the outer part of the slot through the oil injection ring. The arrangement of the oil injection ring makes the cooling structure of the motor more bulky, with lower compactness, occupying a larger space inside the motor housing, and the cooling medium at the oil injection ring is easy to flow to the bottom of the oil injection ring along the circumferential direction of the oil injection ring under the action of gravity, resulting in a poor cooling effect on the outer part of the slot through the spray holes, and a poor heat dissipation performance of the motor.

[0069] In the embodiment of the present application, the cooling medium flows from the cooling channel 11 of the first iron core segment 10 to the cooling hole 213 of the second iron core segment 20 and then sprays onto the outer part 202 of the stator winding 30, changing the parallel flow path in the related art where the cooling medium flows to the stator core and the stator winding in two paths to a series flow path. There is more cooling medium for cooling the stator core 100 and the outer part 202, improving the cooling effect on the stator core 100 and the stator winding 201, and the heat dissipation performance of the motor 300 is better.

[0070] Meanwhile, a plurality of cooling channels 11 capable of flowing a cooling medium are provided on the outer peripheral surface of the first iron core segment 10, and the second iron core segment 20 is provided with a plurality of hole groups 21 communicating with the plurality of cooling channels 11, so that the cooling medium covers a larger area of the outer peripheral surface of the stator core 100 and the inner area of the stator core 100, and the flow velocity of the cooling medium flowing in a turbulent form is relatively fast, and the cooling effect on the stator core 100 is better.

[0071] Moreover, the ejection of the cooling medium can be realized through the second iron core segment 20, which is beneficial to omitting the oil injection ring and the seals required for installing the oil injection ring in the related art, reducing costs, and improving the structural compactness of the motor 300. In addition, adjacent cooling holes 213 in the second iron core segment 20 are not connected, so that the cooling medium in the plurality of cooling holes 213 all ejects axially, increasing the cooling medium sprayed onto the portion 202 outside the slot, having a better cooling effect on the portion 202 outside the slot, and the stator core 100 having better heat dissipation performance.

[0072] For the stator core 100 according to an embodiment of the present invention, by providing the first iron core segment 10 and the second iron core segment 20, the plurality of cooling channels 11 of the first iron core segment 10 are in one-to-one correspondence and communicated with the plurality of hole groups 21 of the second iron core segment 20 and are arranged at intervals along the circumferential direction of the stator core 100, which is beneficial to uniformly cooling the stator core 100 and the stator winding 201 in the circumferential direction, making the stator core 100 and the stator winding 201 dissipate heat evenly. Moreover, the flow area of the cooling holes 213 is smaller than the flow area of the cooling channels 11, so that the cooling medium can eject from the cooling holes 213 to cool the stator winding 201, which is beneficial to increasing the coverage range and spraying distance of the cooling medium, having a better cooling effect on the stator winding 201, and simultaneously being beneficial to omitting the oil injection ring, reducing the number of required components, and improving the structural compactness.

[0073] Since the stator core 100 according to an embodiment of the present invention has the above beneficial technical effects, for the stator assembly 200 according to an embodiment of the present invention, by providing the first iron core segment 10 and the second iron core segment 20, the plurality of cooling channels 11 of the first iron core segment 10 are in one-to-one correspondence and communicated with the plurality of hole groups 21 of the second iron core segment 20 and are arranged at intervals along the circumferential direction of the stator core 100, which is beneficial to uniformly cooling the stator core 100 and the stator winding 201 in the circumferential direction, making the stator core 100 and the stator winding 201 dissipate heat evenly. Moreover, the flow area of the cooling holes 213 is smaller than the flow area of the cooling channels 11, so that the cooling medium can eject from the cooling holes 213 to cool the stator winding 201, which is beneficial to increasing the coverage range and spraying distance of the cooling medium, having a better cooling effect on the stator winding 201, and simultaneously being beneficial to omitting the oil injection ring, reducing the number of required components, and improving the structural compactness.

[0074] Since the stator assembly 200 according to the embodiment of the present invention has the above beneficial technical effects, the motor 300 according to the embodiment of the present invention, by providing the first iron core segment 10 and the second iron core segment 20, the plurality of cooling channels 11 of the first iron core segment 10 are in one-to-one correspondence and communicated with the plurality of hole groups 21 of the second iron core segment 20 and are arranged at intervals along the circumferential direction of the stator iron core 100, which is beneficial to uniformly cooling the stator iron core 100 and the stator winding 201 in the circumferential direction, making the stator iron core 100 and the stator winding 201 dissipate heat evenly, and the flow area of the cooling holes 213 is smaller than the flow area of the cooling channels 11, so that the cooling medium can be ejected from the cooling holes 213 to cool the stator winding 201, which is beneficial to increasing the coverage range and spraying distance of the cooling medium, having a better cooling effect on the stator winding 201, and at the same time being beneficial to eliminating the oil injection ring, reducing the number of required components, and improving the structural compactness.

[0075] In some embodiments of the present invention, as Figures 3 - 4 shown, the hole group 21 includes a plurality of cooling holes 213, and at least two of the plurality of cooling holes 213 are arranged at intervals along the radial direction of the second iron core segment 20. The cooling medium can be ejected from the plurality of cooling holes 213, which is beneficial to increasing the flow rate and cooling range of the cooling medium. And at least two cooling holes 213 are arranged at intervals along the radial direction, so that the cooling holes 213 can be closer to the stator winding 201, that is, closer to the heat source, making the cooling medium in the cooling holes 213 closer to the heat source to improve the cooling efficiency of the cooling medium on the heat source, and making the ejected cooling medium easier to be ejected to the area near the center of the out-of-slot part 202, improving the heat dissipation effect of the stator winding 201 and the stator iron core 100.

[0076] And at least two cooling holes 213 are arranged at intervals along the radial direction, reducing the radial distance between the hole group 21 and the out-of-slot part 202, so that when the cooling medium is ejected from the cooling holes 213 to the out-of-slot part 202, the sputtering loss of the cooling medium can be reduced, enabling more cooling medium to be sprayed onto the out-of-slot part 202 and prolonging the cooling time of the cooling medium on the out-of-slot part 202, improving the cooling efficiency.

[0077] In some embodiments, as Figure 3 shown, at least two of the plurality of cooling holes 213 are arranged at intervals along the circumferential direction of the second iron core segment 20, which can increase the distribution span of the cooling holes 213 in the circumferential direction of the second iron core segment 20, increase the cooling range and spraying range of the cooling medium in the cooling holes 213 in the circumferential direction of the second iron core segment 20, and improve the cooling efficiency.

[0078] In the embodiment of the present application, the second iron core segment 20 can be one or two, and the second iron core segment 20 is arranged on one axial side or both axial sides of the first iron core segment 10 to reduce the number of required oil injection rings. For example, in some embodiments, as Figures 1 - 2As shown, there are two second iron core segments 20, which are respectively arranged on the axial two sides of the first iron core segment 10 to perform oil injection cooling on the parts outside the slots on the axial two sides. This can eliminate the oil injection rings on the axial two sides of the stator iron core 100, simplify the structure of the stator iron core 100 better, and improve production efficiency.

[0079] In some embodiments of the present invention, as Figures 5 - 7 shown, the cooling channel 11 includes a plurality of grooves 111 arranged at intervals in the circumferential direction. The cooling medium can flow in the grooves 111, and the plurality of grooves 111 can change the laminar flow state of more cooling medium into a turbulent flow state, which is beneficial to increasing the heat dissipation area of the stator iron core 100, increasing the flow velocity of the cooling medium, and then improving the heat dissipation performance of the stator iron core 100.

[0080] The depth of the groove 111 in the radial direction of the first iron core segment 10 is a, the outer peripheral surface radius of the stator iron core 100 is R out and the inner peripheral surface radius of the stator iron core 100 is R in , the thickness of the yoke portion 40 of the stator iron core 100 in the radial direction is L, and the axial length of the stator iron core 100 is h. Among them, 0.05 ≤ k1 ≤ 0.1.

[0081] The depth a of the flow channel groove 111 is proportional to the yoke thickness L of the stator iron core 100 and proportional to the axial dimension h of the stator iron core 100. The larger the values of L and h, the larger the depth a can be set. Because at this time, L is thick enough and h is long enough, and L×h is the volume of the yoke portion 40 of the stator iron core 100, and the influence of the depth a on the structural strength and electromagnetic performance is reduced. R out -R in is the width of the stator iron core 100. The width of the stator iron core 100 is the sum of the thickness L of the yoke portion 40 and the thickness of the tooth portion 50. When the thickness L of the yoke portion 40 remains unchanged, as the width of the stator iron core 100 increases, the thickness of the tooth portion 50 increases, which affects the electromagnetic performance and the overall structural strength. At this time, a should be reduced.

[0082] As Figure 7 shown, as k1 gradually increases, the pressure drop of the cooling medium increases, that is, the flow resistance of the cooling medium increases, and the temperature rise of the motor 300 decreases. When k1 is in the range of 0 - 0.05, the pressure drop of the cooling medium increases rapidly; when k1 is greater than 0.1, the pressure drop of the cooling medium increases, but the change degree of the temperature rise of the stator iron core 100 is small.

[0083] As k1 increases, the depth a gradually increases, and the contact area between the cooling medium and the groove 111 gradually increases. Since the convective heat resistance is inversely proportional to this contact area, and the convective heat resistance is inversely proportional to the convective heat transfer coefficient, and the smaller the convective heat resistance, the stronger the heat transfer ability between the cooling medium and the stator core 100. Therefore, the larger the contact area between the cooling medium and the groove 111, the better the cooling effect. However, the larger the contact area between the cooling medium and the groove 111, the higher the flow rate of the cooling medium, and the greater the flow resistance of the cooling medium.

[0084] Therefore, 0.05 ≤ k1 ≤ 0.1. When k1 is within the above range, it is beneficial to meet the requirements of cooling effect and low flow resistance. For example, k1 is 0.05, 0.07, 0.1.

[0085] In some embodiments of the present invention, as Figures 1 - 2 , Figure 5 and Figures 8 - 9 shown, the stator core 100 further includes a third core segment 30. The third core segment 30 is axially located between the second core segment 20 and the first core segment 10. The third core segment 30 is provided with a plurality of communication channels 31 corresponding to the plurality of cooling channels 11. The communication channels 31 connect the cooling channels 11 and the corresponding hole groups 21.

[0086] Through the communication channels 31, the cooling medium in the cooling channels 11 can be introduced into the cooling holes 213. And through the design of the third core segment 30, the structural limitations on the first core segment 10 and the second core segment 20 can be reduced, and the design types of the first core segment 10 and the second core segment 20 can be increased to meet the requirements of different motors 300. It is only necessary to connect the cooling channels 11 and the hole groups 21 through the communication channels 31, and the design is relatively simple and easy to implement.

[0087] In some embodiments, as Figure 3 shown, at least one cooling hole 213 is provided in the yoke portion 40 of the second core segment 20, and at least one cooling hole 213 is provided in the tooth portion 50 of the second core segment 20, which is beneficial to simultaneously cool the yoke portion 40 and the tooth portion 50 of the second core segment 20 and increase the radial cooling range. And the cooling hole 213 provided in the tooth portion 50 can make the cooling medium spray out from the tooth portion 50 to spray onto the outside-of-slot portion 202, and directly cool the portion of the outside-of-slot portion 202 close to the center line of the stator core 100, improving the heat dissipation effect of the area close to the center line of the outside-of-slot portion 202, and the cooling efficiency is relatively high.

[0088] In some embodiments, at least one cooling hole 213 communicates with the tooth slot 51 of the second iron core segment 20. The tooth slot 51 is used to arrange the in-slot part of the stator winding 201. At least one cooling hole 213 communicates with the tooth slot 51, enabling the cooling medium in the cooling hole 213 to spray onto the in-slot part within the tooth slot 51 for cooling, so as to directly cool the in-slot part of the stator winding 201, which is beneficial to improving the heat dissipation effect of the in-slot part. Moreover, the cooling medium in the tooth slot 51 can flow axially along the extending direction of the stator winding 201, that is, along the axial direction to both axial sides of the stator iron core 100, so as to cool the out-of-slot part 202 and improve the heat dissipation effect of the area near the center line of the out-of-slot part 202, which is beneficial to improving the overall heat dissipation effect of the stator winding 201.

[0089] In some embodiments, the axial length of the first iron core segment 10 is greater than the sum of the axial lengths of the second iron core segment 20 and the third iron core segment 30. The cooling flow channel 11 is provided in the yoke portion 40 of the first iron core segment 10. At least one cooling hole 213 is provided in the tooth portion 50 of the second iron core segment 20 and communicates with the tooth slot 51. The communication channel 31 of the third iron core segment 30 connects the cooling flow channel 11 and the cooling hole 213, which can reduce the adverse effects on the performance of the motor 300 on the premise of improving the cooling effect, such as reducing the adverse effects on the structural strength and electromagnetic performance of the stator iron core 100, which is beneficial to protecting the performance of the motor 300. For example, in some specific embodiments, the axial length of the first iron core segment 10 is greater than or equal to 100 mm, and the sum of the axial lengths of the second iron core segment 20 and the third iron core segment 30 is less than or equal to 1 mm.

[0090] In some embodiments, as Figure 3 and Figures 8 - 10 shown, the multiple cooling holes 213 of the same hole group 21 include multiple first cooling holes 211, and the multiple first cooling holes 211 are arranged at intervals along the circumferential direction of the second iron core segment 20. The communication channel 31 includes a first channel 311, and the first channel 311 extends continuously along the circumferential direction of the third iron core segment 30. The first cooling hole 211 and the first channel 311 are axially opposite and communicate with each other, and the cooling flow channel 11 and the first channel 311 are axially opposite and communicate with each other.

[0091] The cooling medium in the cooling flow channel 11 is axially introduced into the first cooling hole 211 through the first channel 311, and the first channel 311 and the first cooling hole 211 are arranged at intervals along the circumferential direction, which can increase the cooling range and spraying range of the cooling medium on the circumference of the stator iron core 100 and improve the cooling efficiency.

[0092] The first channel 311 and the first cooling hole 211 can be provided on the outer peripheral surface or the yoke portion 40 of the stator iron core 100, as long as the first channel 311 connects the cooling flow channel 11 and the first cooling hole 211. For example, in some embodiments, as Figures 9 - 10As shown, the first channel 311 is provided on the outer peripheral surface of the third iron core segment 30, and the first cooling hole 211 is provided in the yoke portion 40 of the second iron core segment 20.

[0093] In some embodiments, as Figure 5 , Figure 8 and Figure 11 shown, the depth of the first channel 311 in the radial direction of the third iron core segment 30 is c, the radius of the outer peripheral surface of the stator iron core 100 is R ou t and the radius of the inner peripheral surface is R in , the thickness of the yoke portion 40 of the stator iron core 100 in the radial direction is L, and the axial length of the stator iron core 100 is h, where 0.045 ≤ k2 ≤ 0.12.

[0094] In some embodiments, as Figures 6 - 7 shown, the depth of the cooling flow channel 11 in the first iron core segment 10 is less than the depth of the communication channel 31 in the third iron core segment 30, and the area of the cooling flow channel 11 in the first iron core segment 10 is much smaller than the area of the communication channel 31 in the third iron core segment 30. The cooling medium first flows through the cooling flow channel 11. When the depth of the cooling flow channel 11 becomes deeper, the area through which the cooling medium flows increases, and thus the pressure drop increases. However, when the cooling medium enters the communication channel 31 from the cooling flow channel 11, the area of the single communication channel 31 increases. With the flow rate remaining unchanged, the area of the communication channel 31 in the third iron core segment 30 is much larger than the area of the cooling flow channel 11 in the first iron core segment 10. At this time, the influence of the decrease in flow velocity on the pressure drop is greater than the influence of the increase in area on the pressure drop, and the pressure drop of the coolant decreases as the k2 value increases.

[0095] As Figure 11 shown, as k2 increases, the pressure drop of the cooling medium gradually decreases, that is, the flow resistance of the cooling medium gradually decreases, but the convective heat transfer coefficient also gradually decreases. When k2 is within the range of 0 to 0.045, the pressure drop of the cooling medium increases relatively fast year-on-year, but the change in the convective heat transfer coefficient is relatively slow; when k2 is greater than 0.12, the rate of decrease in the pressure drop of the cooling medium is slow, but the convective heat transfer coefficient of the motor 300 decreases sharply, and the cooling effect is poor.

[0096] Therefore, 0.045 ≤ k2 ≤ 0.12. When k2 is within the above range, it is beneficial to meet the requirements of cooling effect and low flow resistance. For example, k2 is 0.045, 0.07, 0.12.

[0097] In some embodiments, as Figure 6 , Figure 8 and Figure 12As shown, the cooling channel 11 includes a plurality of grooves 111 arranged at circumferential intervals. The depth of the groove 111 in the radial direction of the first iron core segment 10 is a, the dimension of the groove 111 in the circumferential direction of the first iron core segment 10 is b, the depth of the first channel 311 in the radial direction of the third iron core segment 30 is c, and the dimension of the first channel 311 in the circumferential direction of the third iron core segment 30 is d. Wherein, d = k3×(2a + b) - 2c, and 2.4 ≤ k3 ≤ 8.

[0098] 2a + b is the length of the groove wall of a single first channel 311 perpendicular to the axial section, and c is the depth of the first channel 311 perpendicular to the axial section. The above parameters all have a certain influence on d.

[0099] As Figure 12 shown, as k3 gradually increases, the pressure drop of the cooling medium decreases, and the convective heat transfer coefficient decreases. When k3 is within the range of 2.4 - 8, the change rate of the pressure drop of the cooling medium is slow, and the convective heat transfer coefficient is large; when k3 is greater than 8, the year-on-year decrease value of the convective heat transfer coefficient of the cooling medium is large, and the cooling effect is poor.

[0100] Therefore, 2.4 ≤ k3 ≤ 8. When k3 is within the above range, it is beneficial to meet the requirements of cooling effect and low flow resistance. For example, k3 is 2.4, 5, 8.

[0101] In some embodiments including the first cooling holes 211, as Figure 3 and Figure 8 shown, the plurality of cooling holes 213 of the same hole group 21 further include a plurality of second cooling holes 212. The second cooling holes 212 are located radially inside the first cooling holes 211, and the plurality of second cooling holes 212 are arranged at radial intervals along the second iron core segment 20. The communication channel 31 includes a second channel 312. The second channel 312 extends continuously in the radial direction of the third iron core segment 30, and the radially outer end of the second channel 312 is connected to the radially inner side of the first channel 311. The second cooling holes 212 are axially opposite and communicated with the second channel 312.

[0102] The cooling medium in the first channel 311 is axially introduced into the second cooling holes 212 through the second channel 312, and the second channel 312 and the second cooling holes 212 are arranged at radial intervals, which can increase the cooling range and spraying range of the cooling medium on the stator iron core 100 in the radial direction and improve the cooling efficiency.

[0103] In the radial direction, the second channel 312 is closer to the center of the stator winding 201 than the first channel 311, and the second cooling hole 212 is closer to the center of the stator winding 201 than the first cooling hole 211. The cooling medium can flow through the first channel 311 to the first cooling hole 211 and spray onto the area of the stator winding 201 near the outer surface, and the cooling medium can flow through the second channel 312 to the second cooling hole 212 and spray onto the area of the stator winding 201 near the inside, making the internal and external heat dissipation of the stator winding 201 uniform, which is beneficial to improving the heat dissipation efficiency and effect of the winding.

[0104] In some embodiments, the second channel 312 extends radially to the tooth groove 51, and the first channel 311 is connected to the second channel 312, so that the cooling medium can enter the first channel 311 and the second channel 312 and flow to the tooth groove 51 to directly cool the stator winding 201 in the tooth groove 51, reducing the possibility of cooling medium accumulation and improving the cooling effect of the stator winding 201.

[0105] In some embodiments, as Figure 8 and Figure 13 shown, the flow area of the second channel 312 is S, the depth of the first channel 311 along the radial direction of the third iron core segment 30 is c, and the dimension of the first channel 311 along the circumferential direction of the third iron core segment 30 is d, where S = k4×(c×d), and 0.75≤k4≤1.75.

[0106] As Figure 13 shown, as k4 gradually increases, S increases, the pressure drop of the cooling medium decreases, and the flow rate of the cooling medium in the second channel 312 gradually increases. When k4 is within the range of 0 to 0.75, the flow rate of the cooling medium in the second channel 312 is small, S is small, and the pressure drop is large; when k4 is greater than 1.75, the flow rate of the cooling medium in the second channel 312 is greater than the flow rate of the cooling medium in the first channel 311, and the cooling effect on the outer peripheral surface of the stator winding 201 is not good.

[0107] Therefore, 0.75≤k4≤1.75. When k4 is within the above range, it is beneficial to meet the cooling effect requirements and low flow resistance of the stator winding 201. For example, k4 is 0.75, 1.25, 1.75.

[0108] In some embodiments of the present invention, as Figure 3 and Figure 6 shown, the distance between adjacent first cooling holes 211 in the same hole group 21 is less than the distance between adjacent hole groups 21; the distance between adjacent grooves 111 in the same cooling flow channel 11 is less than the distance between adjacent cooling flow channels 11. This is beneficial to increasing the structural strength and electromagnetic performance of the stator core 100 on the premise of ensuring that the cooling medium has a large spraying range.

[0109] The stator core 100, stator assembly 200, and motor 300 according to a specific embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the following description is only exemplary and should not be construed as a limitation of the invention.

[0110] As Figures 1 - 8 and Figures 11 - 13 shown, the motor 300 according to a specific embodiment of the present invention includes a housing 301, a stator assembly 200, and an internal cavity 305.

[0111] The housing 301 is provided with a liquid inlet 302, a liquid inlet passage 303, a communication port 304, an annular diversion cavity 306, and a liquid outlet. The liquid inlet 302 is provided at the top of the housing 301 and communicates with the outside and the liquid inlet passage 303. The communication port 304 is provided on the inner surface of the housing 301 and communicates with the liquid inlet passage 303 and the annular diversion cavity 306. The annular diversion cavity 306 is provided on the inner circumferential surface of the housing 301 and extends circumferentially along the housing 301 in a ring shape. The liquid outlet is provided at the bottom of the housing 301 and communicates with the outside and the internal cavity 305 of the motor 300.

[0112] The stator assembly 200 is provided inside the housing 301. The stator assembly 200 includes a stator core 100 and a stator winding 201. The stator core 100 includes a first core segment 10, two second core segments 20, and two third core segments 30. The stator core 100 includes a yoke portion 40 and a tooth portion 50. Tooth slots 51 are formed between adjacent tooth portions 50 for passing through the stator winding 201. The stator winding 201 includes an outer-slot portion 202 located on the left and right sides of the stator core 100 and an inner-slot portion located in the tooth slots 51.

[0113] A plurality of cooling channels 11 for circulating a cooling medium are provided on the outer circumferential surface of the first core segment 10. The cooling medium is cooling oil. The plurality of cooling channels 11 are arranged at intervals in the circumferential direction. Each cooling channel 11 communicates with the annular diversion cavity 207. A part of the cooling channels 11 includes three grooves 111, and another part of the cooling channels 11 includes two grooves 111. The grooves 111 penetrate the first core segment 10 in the left-right direction.

[0114] The two second core segments 20 are respectively provided on the left and right sides of the first core segment 10. The second core segment 20 is provided with a plurality of hole groups 21. The plurality of hole groups 21 communicate with the plurality of cooling channels 11 in a one-to-one correspondence. The same hole group 21 includes six cooling holes 213. The six cooling holes 213 include three first cooling holes 211 and three second cooling holes 212. The three first cooling holes 211 are arranged at intervals in the circumferential direction, and the three second cooling holes 212 are arranged at intervals in the radial direction.

[0115] Two third iron core segments 30 are respectively arranged on the left and right sides of the first iron core segment 10, and are arranged between the first iron core segment 10 and the second iron core segment 20. The second iron core segment 20 is provided with a plurality of communication channels 31, and the plurality of communication channels 31 are in one-to-one correspondence and communication with the plurality of cooling channels 11. The communication channel 31 is in a T shape and includes a first channel 311 and a second channel 312. The first channel 311 extends continuously in the circumferential direction and communicates with the cooling channels 11 on both sides and the first cooling hole 211. The second channel 312 extends continuously in the radial direction and communicates with the first channel 311 and the second cooling hole 212.

[0116] When the motor 300 works, as Figures 1 - 2 shown by the arrow in the figure, first, cooling oil is introduced into the housing 301 from the liquid inlet 302. After the cooling oil enters the housing 301, it flows in the liquid inlet channel 303 and flows through the communication port 304 to the annular diversion cavity 306 to flow along the circumferential direction of the stator core 100, and then is shunted into the plurality of grooves 111 of the plurality of cooling channels 11 to cool the stator core 100.

[0117] The cooling oil in the cooling channel 11 flows in the left-right direction and passes through the first channel 311. The cooling oil in the first channel 311 flows in the left-right direction to the first cooling hole 211 and then flows in the radial direction to the second channel 312. The cooling oil in the second channel 312 flows in the left-right direction to the second cooling hole 212. The cooling oil in the first cooling hole 211 and the second cooling hole 212 sprays towards the inner cavity 305 at the outer end of the stator core 100 in the left-right direction. When the cooling oil flows in the annular diversion cavity 306, the cooling channel 11 and the cooling hole 213, it can cool the stator core 100. When the cooling oil sprays onto the part 202 outside the groove, it can cool and lower the temperature of the stator winding 201, making the heat dissipation of the stator assembly 200 uniform and improving the heat dissipation effect and heat dissipation performance of the motor 300.

[0118] The cooling oil in the inner cavity 305 can flow out through the liquid outlet, realizing the cooling of the motor 300 by the cooling oil and improving the heat dissipation performance of the motor 300.

[0119] As Figure 14As shown, the powertrain 400 according to an embodiment of the present invention includes the motor 300 according to an embodiment of the present invention. Since the motor 300 according to an embodiment of the present invention has the above beneficial technical effects, the powertrain 400 according to an embodiment of the present invention, by providing the first iron core segment 10 and the second iron core segment 20, the plurality of cooling channels 11 of the first iron core segment 10 communicate with the plurality of hole groups 21 of the second iron core segment 20 in one-to-one correspondence and are arranged at intervals along the circumferential direction of the stator core 100, which is beneficial to uniformly cooling the stator core 100 and the stator winding 201 circumferentially, making the stator core 100 and the stator winding 201 dissipate heat evenly, and the flow area of the cooling holes 213 is smaller than the flow area of the cooling channels 11, so that the cooling medium can be ejected from the cooling holes 213 to cool the stator winding 201, which is beneficial to increasing the coverage range and spraying distance of the cooling medium, having a better cooling effect on the stator winding 201, and at the same time being beneficial to eliminating the oil injection ring, reducing the number of required components, and improving the structural compactness.

[0120] Here, the powertrain 400 refers to an integrated structure of a series of components on a vehicle for generating power to drive the vehicle. For example, the powertrain 400 may include the motor 300, a transmission, and the remaining components integrated into the transmission, such as a clutch, a differential, etc., so that the motor 300 serves as the main driving force of the vehicle; for another example, the powertrain 400 may further include an internal combustion engine, so that the internal combustion engine and the motor 300 serve as the main driving forces simultaneously. Regarding the internal combustion engine and the motor 300 that simultaneously provide driving power mentioned in the above embodiments, the internal combustion engine may use gasoline, diesel, hydrogen, etc. as fuel, and the way to supply electric energy to the motor 300 may use a power battery, a hydrogen fuel cell, etc., which are not specifically limited here.

[0121] As Figure 14 As shown, the vehicle 1000 according to an embodiment of the present invention includes the powertrain 400 according to an embodiment of the present invention. Since the powertrain 400 according to an embodiment of the present invention has the above beneficial technical effects, the vehicle 1000 according to an embodiment of the present invention, by providing the first iron core segment 10 and the second iron core segment 20, the plurality of cooling channels 11 of the first iron core segment 10 communicate with the plurality of hole groups 21 of the second iron core segment 20 in one-to-one correspondence and are arranged at intervals along the circumferential direction of the stator core 100, which is beneficial to uniformly cooling the stator core 100 and the stator winding 201 circumferentially, making the stator core 100 and the stator winding 201 dissipate heat evenly, and the flow area of the cooling holes 213 is smaller than the flow area of the cooling channels 11, so that the cooling medium can be ejected from the cooling holes 213 to cool the stator winding 201, which is beneficial to increasing the coverage range and spraying distance of the cooling medium, having a better cooling effect on the stator winding 201, and at the same time being beneficial to eliminating the oil injection ring, reducing the number of required components, and improving the structural compactness.

[0122] Here, the vehicle 1000 can be a new energy vehicle. In some embodiments, the new energy vehicle can be a pure electric vehicle with the motor 300 as the main driving force. In other embodiments, the new energy vehicle can also be a hybrid vehicle with both an internal combustion engine and the motor 300 components as the main driving force. It should be noted that this is only an exemplary description of the structure of the new energy vehicle and the like, and does not limit the protection scope of the present invention.

[0123] For those of ordinary skill in the art, the other components and operations of the stator core 100, stator assembly 200, motor 300, powertrain 400, and vehicle 1000 according to the embodiments of the present invention are known, and will not be described in detail here.

[0124] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0125] In the description of this specification, the descriptions referring to terms such as "embodiment", "specific embodiment", "example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0126] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A stator core, characterized in that: include: a first core segment, wherein a plurality of cooling channels are provided on an outer circumferential surface of the first core segment, the plurality of cooling channels are spaced apart along the circumference of the first core segment, and the cooling channels penetrate the first core segment along the axial direction of the first core segment; The second core segment is arranged on one axial side of the first core segment, and the second core segment is provided with a plurality of hole groups arranged at intervals along the circumferential direction, and the plurality of hole groups are connected with the plurality of cooling channels in a one-to-one correspondence, and the hole groups include cooling holes, and the cooling holes in the same hole group are all connected with the corresponding cooling channels, and the flow area of the cooling holes is smaller than the flow area of the cooling channels.

2. The stator core according to claim 1, characterized in that The hole group includes a plurality of the cooling holes, and at least two of the plurality of cooling holes are spaced apart in a radial direction of the second core segment.

3. The stator core according to claim 2, characterized in that At least two of the plurality of cooling holes are spaced apart from each other along the circumference of the second core segment.

4. The stator core according to claim 1, wherein: There are two second core segments, and the two second core segments are respectively arranged on two axial sides of the first core segment.

5. The stator core according to claim 1, characterized in that The cooling channel includes a plurality of grooves spaced apart along the circumferential direction, the depth of the grooves along the radial direction of the first core segment is a, and the outer circumferential radius of the stator core is R out And the inner radius is R in , the radial thickness of the yoke of the stator core is L, and the axial length of the stator core is h, wherein, 6. The stator core according to any one of claims 1 to 5, characterized in that: Also includes: The third core segment is axially located between the second core segment and the first core segment, and the third core segment is provided with a plurality of connecting channels corresponding to the plurality of cooling channels, and the connecting channels connect the cooling channels and the corresponding hole groups.

7. The stator core according to claim 6, characterized in that At least one of the cooling holes is provided in the yoke of the second core segment; and at least one of the cooling holes is provided in the tooth of the second core segment.

8. The stator core according to claim 7, characterized in that At least one of the cooling holes is in communication with a tooth slot of the second core segment.

9. The stator core according to claim 6, characterized in that The plurality of cooling holes in the same hole group include a plurality of first cooling holes, and the plurality of first cooling holes are spaced apart and arranged along the circumference of the second core segment; The communicating channel includes a first channel, the first channel continuously extends along the circumference of the third core segment, the first cooling hole is axially opposite to and communicates with the first channel, and the cooling channel is axially opposite to and communicates with the first channel.

10. The stator core according to claim 9, characterized in that The depth of the first channel along the radial direction of the third core segment is c, and the radius of the outer peripheral surface of the stator core is R out And the inner radius is R in , the radial thickness of the yoke of the stator core is L, and the axial length of the stator core is h, wherein, 11. The stator core according to claim 9, characterized in that The cooling channel includes a plurality of grooves spaced apart along the circumferential direction, the depth of the grooves along the radial direction of the first core segment is a, the size of the grooves along the circumferential direction of the first core segment is b, the depth of the first channel along the radial direction of the third core segment is c, and the size of the first channel along the circumferential direction of the third core segment is d, wherein, d=k3×(2a+b)-2c, 2.4≤k3≤8.

12. The stator core according to claim 9, characterized in that The plurality of cooling holes in the same hole group further include a plurality of second cooling holes, the second cooling holes are located radially inward of the first cooling holes, and the plurality of second cooling holes are spaced apart in the radial direction of the second core segment; The communicating channel includes a second channel, the second channel continuously extends radially along the third core segment, and the radial outer end of the second channel is connected to the radial inner side of the first channel, and the second cooling hole is axially opposite to and communicates with the second channel.

13. The stator core according to claim 12, characterized in that The flow area of the second channel is S, the depth of the first channel along the radial direction of the third core segment is c, and the dimension of the first channel along the circumferential direction of the third core segment is d, wherein, S=k4×(c×d), 0.75≤k4≤1.

75.

14. A stator assembly, characterized in that: The invention comprises a stator core according to any one of claims 1 to 13.

15. A motor, characterized in that: Comprising a stator assembly according to claim 14.

16. A powertrain, characterized in that: comprising the motor according to claim 15.

17. A vehicle, characterized in that: Comprising the powertrain according to claim 16.

Images