motor

Abstract

This disclosure discloses an electric motor comprising: a housing; and a stator housed within the housing, the stator including a stator core and stator windings, the stator core having a plurality of circumferentially spaced winding slots, each winding slot extending axially through the stator core and housing a plurality of wires of the stator windings, the plurality of wires being stacked in the winding slots, and each wire defining an axial channel extending axially through the stator core with a sidewall of the winding slot, wherein the electric motor has a circumferentially arranged circumferential channel located radially outward of the plurality of winding slots within the housing, and wherein the stator core further has a plurality of distribution holes, each distribution hole having an outer end leading to the circumferential channel and an inner end open on the sidewall of a corresponding winding slot, such that each axial channel communicates with the circumferential channel through the corresponding distribution hole.

Description

Technical Field

[0001] This disclosure relates to the field of electric motors, and more specifically, to an electric motor with an improved liquid-cooled design. Background Technology

[0002] With the rapid development of electric motors, power density and lightweight design have received increasing attention. However, heat dissipation has become a major factor restricting further improvements in power density. Taking a common permanent magnet synchronous motor as an example, the stator windings generate a rotating magnetic field after an alternating current is applied. This rotating magnetic field couples with the permanent magnets on the rotor, driving the rotor to rotate. However, at the same time, the rotating magnetic field causes eddy currents to form in the rotor and stator cores, leading to heating of both. The alternating current, in turn, causes the stator windings to heat up, with the stator windings generating the most heat and being the most difficult to dissipate. To increase the motor's power, a larger alternating current needs to be applied to the stator windings, but this also increases the heat generated by the stator core, stator windings, and rotor core. If this heat cannot be effectively dissipated, it may shorten the motor's lifespan or even cause it to overheat and burn out. In the existing technology, there are a number of liquid cooling solutions to help dissipate heat from motors, including setting the stator core in a water jacket and machining coolant channels in the stator core. However, these liquid cooling solutions all have the problem of not being able to effectively dissipate heat from the stator windings to some extent.

[0003] Therefore, there is an urgent need in this field for a technical solution that can help the stator windings of an electric motor to effectively dissipate heat. Utility Model Content

[0004] To address the problems in the prior art described above, this disclosure proposes an improved motor comprising: a housing; and a stator housed within the housing, the stator including a stator core and stator windings, the stator core having a plurality of circumferentially spaced winding slots, each winding slot extending axially through the stator core and accommodating a plurality of wires of the stator windings, the plurality of wires being stacked in the winding slots, and each wire defining an axial channel extending axially through the stator core with a sidewall of the winding slot, wherein the motor has a circumferentially arranged circumferential channel located radially outward of the plurality of winding slots within the housing, and wherein the stator core further has a plurality of distribution holes, each distribution hole having an outer end leading to the circumferential channel and an inner end open on the sidewall of a corresponding winding slot, such that each axial channel communicates with the circumferential channel through a corresponding distribution hole.

[0005] According to an optional embodiment of this disclosure, the stator core includes an outer stator yoke, an inner stator yoke located radially inside the outer stator yoke, and a plurality of stator teeth connecting the outer stator yoke and the inner stator yoke. The plurality of stator teeth are circumferentially spaced apart from each other to define the plurality of winding slots. Each winding slot has a sidewall provided by the outer stator yoke, two sidewalls provided by the stator teeth on both sides, and a sidewall provided by the inner stator yoke.

[0006] According to an optional embodiment of this disclosure, the motor further includes a rotor disposed radially inside the stator and an isolation cylinder disposed between the stator and the rotor, the two ends of the isolation cylinder being located on opposite sides of the stator core along the axial direction.

[0007] According to one alternative embodiment of this disclosure, the isolation cylinder abuts against the inner stator yoke.

[0008] According to one alternative embodiment of this disclosure, the two ends of the isolation cylinder are spaced apart from the housing.

[0009] According to an alternative embodiment of this disclosure, the stator core includes an outer stator yoke and a plurality of stator teeth projecting inward from the outer stator yoke. The plurality of stator teeth are circumferentially spaced apart to define a plurality of winding slots. Each winding slot has a sidewall provided by the outer stator yoke and two sidewalls provided by the stator teeth on both sides. The free end of each stator tooth forms a pole shoe, and the pole shoes of the plurality of stator teeth are spaced apart to define a plurality of pole shoe gaps.

[0010] According to an alternative embodiment of this disclosure, the stator further includes a plurality of sealing wedges, each pole shoe gap accommodating a corresponding sealing wedge and being completely filled by the sealing wedges.

[0011] According to an optional embodiment of this disclosure, the motor further includes a rotor disposed radially inside the stator and an isolation cylinder disposed between the stator and the rotor, the two ends of the isolation cylinder being located on opposite sides of the stator core along the axial direction.

[0012] According to one alternative embodiment of this disclosure, the isolation cylinder abuts against the pole shoe of each stator tooth.

[0013] According to one alternative embodiment of this disclosure, the two ends of the isolation cylinder are spaced apart from the housing.

[0014] According to an alternative embodiment of this disclosure, the isolation cylinder is provided with a plurality of sealing wedges fixed on its radial outer surface, each sealing wedge being inserted into and completely filling the corresponding pole shoe gap.

[0015] According to an alternative embodiment of this disclosure, each winding slot has a partially enlarged portion that forms an annular channel surrounding all the wires in the winding slot, and the inner end of each distribution hole is open on the sidewall of the partially enlarged portion of the corresponding winding slot.

[0016] According to one alternative embodiment of this disclosure, each dispensing hole is radially oriented.

[0017] According to an alternative embodiment of this disclosure, each sidewall of each winding groove defines an axial channel with a corresponding wire and has an inner end provided with a distribution hole leading to the axial channel.

[0018] According to an optional embodiment of this disclosure, the plurality of distribution holes includes a plurality of first distribution holes and a plurality of second distribution holes, the inner end of each first distribution hole being open on the sidewall of the corresponding winding slot provided by the outer stator yoke, and each second distribution hole having at least one inner end, the at least one inner end being open on at least one of the following: on the sidewall of the winding slot on at least one side of the corresponding stator tooth and on the sidewall of one of the two winding slots on both sides of the corresponding stator tooth provided by the inner stator yoke.

[0019] According to one alternative embodiment of this disclosure, each first dispensing hole is radially oriented.

[0020] According to an alternative embodiment of this disclosure, each winding slot has two sidewalls provided by stator teeth on both sides that define multiple axial channels with corresponding multiple wires and has an inner end with a distribution hole leading to the multiple axial channels.

[0021] According to an alternative embodiment of this disclosure, each distribution hole has two inner ends, and the two inner ends are respectively open on two sidewalls provided by two winding slots on both sides of the corresponding stator teeth.

[0022] According to one optional embodiment of this disclosure, the radially outer surface of the stator core abuts against the inner surface of the housing, and wherein the circumferential channel is formed by a groove recessed from the radially outer surface of the stator core and arranged circumferentially; or, the circumferential channel is formed by a groove recessed from the inner surface of the housing and arranged circumferentially; or, the circumferential channel is composed of a groove recessed from the radially outer surface of the stator core and arranged circumferentially and a groove recessed from the inner surface of the housing and arranged circumferentially.

[0023] According to an optional embodiment of this disclosure, the housing is provided with an extending through-hole and two drain holes, the inlet hole being in communication with the circumferential channel, and the two drain holes being located on opposite sides of the stator core along the axial direction.

[0024] According to an alternative embodiment of this disclosure, each wire is provided with a groove recessed from its surface and extending along its length, and is arranged in the winding groove such that the surface with the groove abuts against the sidewall of the winding groove.

[0025] According to an alternative embodiment of the present disclosure, the stator core includes a plurality of stator laminations stacked together axially and a distribution lamination located between two stator laminations, each distribution hole being formed in the distribution lamination, and the circumferential channel being formed radially outward of the distribution lamination.

[0026] According to an alternative embodiment of this disclosure, each distribution hole and the circumferential channel are positioned at the midpoint of the stator core along the axial direction.

[0027] This disclosure may be embodied in the illustrative embodiments shown in the accompanying drawings. However, it should be noted that the drawings are merely illustrative, and any variations contemplated under the teachings of this disclosure should be considered to be included within the scope of this disclosure. Attached Figure Description

[0028] The accompanying drawings illustrate exemplary embodiments of this disclosure. These drawings should not be construed as necessarily limiting the scope of this disclosure, wherein:

[0029] Figure 1 This is a schematic cross-sectional view of a motor according to a first embodiment of the present disclosure;

[0030] Figure 2 yes Figure 1 A schematic three-dimensional view of the stator core of the motor shown;

[0031] Figure 3 It is along Figure 1 A schematic cross-sectional view of the motor stator taken by line III-III in the figure;

[0032] Figure 4 This is a schematic cross-sectional view of a motor according to a second embodiment of the present disclosure;

[0033] Figure 5 It is along Figure 4 A schematic cross-sectional view of the motor stator taken by line VV in the figure;

[0034] Figure 6 This is a schematic cross-sectional view of a motor according to a third embodiment of the present disclosure;

[0035] Figure 7 It is along Figure 6 A schematic cross-sectional view of the stator of the motor, taken by line VII-VII in the figure;

[0036] Figure 8 yes Figure 1 , Figure 4 and Figure 6 A schematic perspective view of the isolation cylinder of the motor shown;

[0037] Figure 9 This is a schematic cross-sectional view of a motor according to the fourth embodiment of the present disclosure;

[0038] Figure 10 yes Figure 9 A schematic three-dimensional view of the stator core of the motor shown;

[0039] Figure 11 It is along Figure 9 A schematic cross-sectional view of the motor stator taken by line XI-XI;

[0040] Figure 12 This is a schematic cross-sectional view of an electric motor according to the fifth embodiment of this disclosure;

[0041] Figure 13 It is along Figure 12 A schematic cross-sectional view of the motor stator taken by line XIII-XIII; and

[0042] Figure 14 yes Figure 9 and Figure 12 A schematic perspective view of the stator of the motor with the stator windings removed. Detailed Implementation

[0043] Further features and advantages of this disclosure will become more apparent from the following description with reference to the accompanying drawings. Exemplary embodiments of this disclosure are shown in the drawings, and the drawings are not necessarily drawn to scale. However, this disclosure can be implemented in many different forms and should not be construed as necessarily limited to the exemplary embodiments shown herein. Rather, these exemplary embodiments are provided merely to illustrate this disclosure and to convey the spirit and essence of this disclosure to those skilled in the art.

[0044] This disclosure aims to provide a novel liquid-cooled motor design that allows the coolant to directly contact the stator winding conductors within each winding slot of the stator core. This enables direct cooling of the stator winding conductors within each slot (referred to as in-slot direct cooling), thereby achieving efficient heat dissipation of the stator windings. Specifically, the liquid-cooled design also improves the uniformity of temperature distribution in the axial direction of the stator core and stator windings, and enhances the uniformity of coolant pressure distribution within each winding slot. This not only contributes to efficient cooling of the stator winding conductors along the entire length of each winding slot but also reduces the pressure required to drive the coolant flow within each slot, thereby reducing the performance requirements of auxiliary equipment such as hydraulic pumps and ultimately lowering the configuration cost of the cooling design according to this disclosure. In particular, the liquid cooling design according to this disclosure can also directly cool the winding heads of the stator winding located on both sides of the stator core, and it is not necessary to set a sealing structure for sealing the coolant on the end cover of the motor. This can not only further promote the efficient heat dissipation of the stator winding, but also further reduce the configuration cost of the cooling design according to this disclosure.

[0045] Various alternative, but non-limiting, embodiments of the motor according to this disclosure are described in detail below with reference to the accompanying drawings. As used herein, the term "axial" refers to a direction parallel to or defined by the axis of rotation of the motor; "radial" refers to a direction perpendicular to the axis of rotation of the motor; "circumferential" refers to a direction surrounding the axis of rotation of the motor; and "tangential" refers to a direction tangent to any circle whose center lies on the axis of rotation, and thus "tangential" is also perpendicular to "radial". Unless otherwise expressly stated herein, these and other directional terms have their common meaning in the art, and their use is merely intended to convey the teachings of this disclosure more intuitively in conjunction with the accompanying drawings, and should not be construed in any way as limiting the scope of this disclosure.

[0046] refer to Figure 1 A schematic cross-sectional view of a motor according to a first embodiment of the present disclosure is shown. Figure 1As shown, the motor 10 is positioned such that its rotation axis XX' is oriented horizontally, and generally includes a housing 100, a stator 200 fixedly disposed within the housing 100, a rotor 300 adapted to be coupled to the stator 200 via magnetic flux, and a main shaft 400 supporting the rotor 300 and rotatably disposed within the housing 100. The stator 200 is disposed radially outside the rotor 300 and generally includes a stator core 210 fixed to the housing 100 and stator windings 220 attached to the stator core 210. The rotor 300 generally includes a rotor core 310 fixed to the main shaft 400 and a plurality of permanent magnets 320 attached to the rotor core 310. The main shaft 400 is oriented along the rotation axis XX' such that the main shaft 400 can rotate with the rotor 300 around the rotation axis XX' under the drive of the rotor 300. Figure 1 In the embodiment shown, the motor 10 is configured as a permanent magnet synchronous motor. When it is running, the stator winding 220 is energized with alternating current, thereby generating a rotating magnetic field that rotates around the rotation axis XX'. Under the guidance of the stator core 210, the rotating magnetic field is magnetically coupled to multiple permanent magnets 320 on the rotor core 310, thereby driving the multiple permanent magnets 320 and the rotor core 310 connected to them to rotate around the rotation axis XX'. The rotor core 310, in turn, drives the main shaft 400 to rotate around the rotation axis XX', thus realizing the conversion of electrical energy into mechanical energy.

[0047] refer to Figure 2 , which shows Figure 1 The diagram shows a schematic three-dimensional view of the stator core of the motor. (See attached image.) Figure 1 and Figure 2As shown, the stator core 210 is generally cylindrical and has two axial surfaces 211 that are spaced apart from each other or opposite to each other along the axial direction and two radial surfaces 212, 213 that are spaced apart from each other or opposite to each other along the radial direction. The two radial surfaces 212, 213 are composed of a radial inner surface 212 that is close to or faces the rotor 300 and a radial outer surface 213 that is away from or opposite to the rotor 300. The two axial surfaces 211 are generally planar, while the two radial surfaces 212, 213 are generally cylindrical. The stator core 210 is fixed to the housing 100 such that its radial outer surface 213 fits against or abuts the inner surface 101 of the housing 100. Additionally, the stator core 210 includes an outer stator yoke 210a and an inner stator yoke 210b, both generally cylindrical, and a plurality of stator teeth 210c connecting the outer stator yoke 210a and the inner stator yoke 210b. The outer stator yoke 210a is located radially outside the inner stator yoke 210b to surround or enclose the inner stator yoke 210b. The stator teeth 210c are evenly distributed and spaced apart from each other in the circumferential direction to define a plurality of winding slots 214 that are also evenly distributed and spaced apart from each other in the circumferential direction. Each of these winding slots 214 extends axially from one axial surface 211 of the stator core 210 to another axial surface 211, that is, each winding slot 214 extends axially through the stator core 210. In this configuration, the radially inner surface 212 and radially outer surface 213 of the stator core 210 are provided by the inner stator yoke 210b and the outer stator yoke 210a, respectively, and each winding slot 214 has two sidewalls provided by stator teeth 210c on both sides, spaced apart or opposite to each other in the circumferential direction, and two sidewalls provided by the inner stator yoke 210b and the outer stator yoke 210a, spaced apart or opposite to each other in the radial direction. Furthermore, it is worth mentioning that since each winding slot 214 is closed radially outward by the outer stator yoke 210a and radially inward by the inner stator yoke 210b, therefore... Figure 2 The stator core 210 shown has a fully enclosed slot configuration.

[0048] Back Figure 1 The stator winding 220 is actually composed of a large number of wires (e.g., U-shaped wires, X-shaped wires, or I-shaped wires, etc.). Multiple wires 221 of the stator winding 220 are provided in each winding slot 214 of the stator core 210. The stator winding 220 is attached to the stator core 210 in this manner, and these wires 221 are stacked together in a specific manner in the winding slot 214 and connected together in a specific manner outside the winding slot 214, thereby forming a winding head 222 located outside the stator core 210 (more specifically, spaced apart from the stator core 210 along the axial direction). Figure 1In the illustrated embodiment, the stator winding 220 has two winding ends 222 located on opposite sides of the stator core 210 along the axial direction. Of course, in embodiments not shown, the stator winding 220 may also have only one winding end 222 located on one side of the stator core 210 in the axial direction. With the aid of the winding ends 222, the stator winding 220 can receive alternating current from an external power supply circuit (e.g., an inverter), and the specific connection of the wires in the winding ends 222 causes the wires in each winding slot 214 to generate a rotating magnetic field of desired frequency and intensity, thereby converting electrical energy into mechanical energy as described above. However, as a byproduct of mechanical energy, the rotating magnetic field causes eddy currents in the stator core 210 and rotor core 310, and due to the resistance of the stator winding 220 itself, all three components—stator core 210, rotor core 310, and stator winding 220—generate heat. Among these, the stator winding 220 generates the most heat and is the most difficult to dissipate. Therefore, the heat dissipation problem of the stator winding 220 is one of the main limiting factors for the service life and performance improvement of the motor.

[0049] To achieve effective heat dissipation of the stator winding 220, the motor 10 features an improved liquid cooling design. Specifically, refer to... Figures 1-3 ,in Figure 3 It shows along Figure 1 A schematic cross-sectional view of the motor stator, taken from line III-III. (See figure.) Figures 1-3 As shown, the motor 10 has a circumferential channel 102 arranged in the circumferential direction (i.e., around the rotation axis XX') within the housing 100. This circumferential channel 102 is positioned radially outward of each winding slot 214 and is continuously arranged along the entire circumference so as to surround the plurality of winding slots 214 radially outward. Specifically, in Figures 1-3 In the illustrated embodiment, the circumferential channel 102 is formed by a groove 215 recessed from the radial outer surface 213 of the stator core 210 and arranged in the circumferential direction (i.e., around the rotation axis XX'). Of course, in embodiments not shown, the circumferential channel 102 may also be formed by a groove recessed from the inner surface 101 of the housing 100 and arranged in the circumferential direction (i.e., around the rotation axis XX'), or by a combination of a groove recessed from the radial outer surface 213 of the stator core 210 and a groove recessed from the inner surface 101 of the housing 100. Figures 1-3As shown, the stator core 210 has a plurality of distribution holes 216 evenly distributed and spaced apart from each other along the circumferential direction. Each distribution hole 216 has an outer end away from the rotation axis XX' and an inner end close to the rotation axis XX'. The outer end opens to the circumferential channel 102, while the inner end is open on one sidewall of a winding slot 214, so that each winding slot 214 can be in fluid communication with the circumferential channel 102 through the corresponding distribution hole 216. Figure 3 As shown in the enlarged view, each conductor 221 in the winding slot 214 is generally Ω-shaped and has a groove 221r ​​recessed from its surface and extending along its length. Each conductor 221 is positioned such that the surface with the groove 221r ​​faces a sidewall of the winding slot 214, such that each conductor 221 and the sidewall of the winding slot 214 define an axial channel 217 extending axially through the stator core 210. Since the inner end of the distribution hole 216 is open on the sidewall of the winding slot 214, each axial channel 217 can be in fluid communication with the circumferential channel 102 through the corresponding distribution hole 216. Additionally, returning to... Figure 1 The housing 100 also includes a liquid inlet 103 and two liquid outlets 104. The liquid inlet 103 extends through the housing 100 and is in fluid communication with the circumferential channel 102, while the two liquid outlets 104 are located on opposite sides of the stator core 210 along the axial direction and are in fluid communication with a cavity 105 defined internally by the housing 100. Specifically, as... Figure 2 As shown, the stator core 210 may include a plurality of stator laminations 210d stacked together along the axial direction and a distribution lamination 210e located between two stator laminations 210d, wherein each distribution hole 216 is formed in the distribution lamination 210e, and a circumferential channel 102 surrounds the distribution lamination 210e radially outward. More specifically, the radial dimension (i.e., radius or diameter) of the distribution lamination 210e is smaller than the radial dimension of the stator laminations 210d, such that the outer edge of the distribution lamination 210e is radially offset inward relative to the outer edge of the stator laminations 210d, thereby defining the circumferential channel 102 wholly or partially between the stator laminations 210d on both sides of the distribution lamination 210e.

[0050] In the above configuration, coolant from outside the housing 100 of the motor 10 (e.g., a cooling pump) can enter the interior of the housing 100 through the inlet hole 103 and be delivered to the circumferential channel 102. The coolant entering the circumferential channel 102 will flow in the circumferential direction in the circumferential channel 102, thereby distributing it radially outward from all the winding slots 214. Furthermore, since each axial channel 217 in each winding slot 214 is in fluid communication with the circumferential channel 102 through a corresponding distribution hole 216, the coolant will flow from the circumferential channel 102 to each axial channel 217 and flow along the axial channel 217 to the two axial surfaces 211 of the stator core 210. This allows each conductor 221 and the sidewall of the winding slot 214 to directly contact the coolant in the axial channel 217, thereby achieving efficient heat dissipation for both the stator core 210 and the stator winding 220. Furthermore, the coolant in each axial channel 217 is discharged into the chamber 105 after passing over the two axial surfaces 211 of the stator core 210. The coolant in the chamber 105 can then be discharged to the outside of the motor housing 100 (e.g., a cooling pump) through two drain holes 104. It is also worth noting that the above configuration defines a flow path that allows coolant to flow in from the middle of each axial channel 217 and out from both ends. Compared to a flow path that allows coolant to flow from one end of each axial channel 217 to the other, this configuration improves the pressure and temperature distribution in each axial channel 217, reduces the pressure required to drive the coolant flow, and eliminates the need to establish sealed coolant chambers on both sides of the stator core 210, thereby reducing the configuration cost of the liquid cooling design according to this disclosure.

[0051] like Figure 1 and Figure 2 As shown, the circumferential channel 102 and each distribution hole 216 can be positioned at the midpoint of the stator core 210 in the axial direction, such that the circumferential channel 102 and each distribution hole 216 are approximately equidistant from the two axial surfaces 211 of the stator core 210 in the axial direction. In this configuration, coolant flows into the midpoint of each axial channel 217 and exits from both ends of the axial channel 217 after flowing approximately the same distance in opposite directions. This further improves the pressure and temperature distribution in each axial channel 217 and further reduces the pressure required to drive the coolant flow.

[0052] like Figure 1 and Figure 3As shown, each winding groove 214 has a partially enlarged portion 214e, the sidewall of which is offset outward relative to the sidewall of the rest of the winding groove 214 (i.e., away from the wires 221 in the winding groove 214). Since the surface of each wire 221 with a groove 221r ​​abuts against the sidewall of the rest of the winding groove 214, the partially enlarged portion 214e can form an annular channel surrounding all the wires 221 in the winding groove 214, and the groove 221r ​​of each wire 221 opens toward this annular channel, thereby allowing the annular channel to be in fluid communication with each axial channel 217. Specifically, the partially enlarged portion 214e of each winding groove 214 is positioned at the midpoint of the winding groove 214 in the axial direction. Furthermore, the dispensing hole 216 opens at its outer end to the circumferential channel 102 and at its inner end to the annular channel formed by the partially enlarged portion 214e. Specifically, the distribution holes 216 extend radially from the outer end to the sidewall provided by the outer stator yoke 210a of the partially enlarged portion 214e. In this configuration, coolant from the circumferential channel 102 can be delivered by each distribution hole 216 to the partially enlarged portion 214e of the corresponding winding slot 214, and then the annular channel formed by the partially enlarged portion 214e can distribute the coolant to each axial channel 217. Therefore, the above configuration achieves the distribution of coolant from the circumferential channel 102 to each axial channel 217 simply by providing the partially enlarged portion 214e of the winding slot 214 in the stator core 210 and the same number of distribution holes 216 as the winding slot 214, thereby enabling the liquid cooling design according to this disclosure to achieve efficient heat dissipation of both the stator core 210 and the stator winding 220 at a lower configuration cost. In addition, it is worth mentioning that although in Figure 3 As shown, the surface of each wire 221 with a groove 221r ​​abuts against one of the two sidewalls of the winding groove 214 provided by the stator teeth 210c on both sides. However, those skilled in the art will understand that the above configuration can achieve the distribution of coolant in the circumferential channel 102 to each axial channel 217 regardless of which sidewall of the winding groove 214 the surface of the wire 221 with a groove 221r ​​abuts against.

[0053] refer to Figure 4 and Figure 5 ,in, Figure 4 A schematic cross-sectional view of a motor according to a second embodiment of the present disclosure is shown, and Figure 5 It shows along Figure 4 A schematic cross-sectional view of the motor stator taken by line VV. Figure 4 and Figure 5 The second embodiment shown is similar to Figures 1-3The first embodiment shown is largely the same, with the main difference being that the winding groove 214 and the distribution hole 216 have different configurations. Specifically, as Figure 5 As shown in the enlarged view, the winding groove 214 does not include the enlarged portion 214e, and each sidewall of the winding groove 214 defines an axial channel 217 with the corresponding wire 221 in the winding groove 214. Additionally, the plurality of distribution holes 216 include a plurality of first distribution holes 216a and a plurality of second distribution holes 216b. Each first distribution hole 216a opens to the circumferential channel 102 at its outer end, and its inner end is open on the sidewall of the corresponding winding groove 214 provided by the outer stator yoke 210a. Each second distribution hole 216b also opens to the circumferential channel 102 at its outer end, but unlike the first distribution holes 216a, each second distribution hole 216b has three inner ends, which are respectively open on the two sidewalls provided by the two winding grooves 214 on either side of the corresponding stator tooth 210c and on the sidewall provided by the inner stator yoke 210b of one of the two winding grooves 214. In this configuration, each sidewall of the winding slot 214 is provided with an inner end of a first distribution hole 216a or a second distribution hole 216b. This allows each sidewall of the winding slot 214 and the axial channel 217 defined by the corresponding conductor 221 to be in fluid communication with the circumferential channel 102 through the first distribution hole 216a or the second distribution hole 216b. Therefore, by providing the same number of first distribution holes 216a and second distribution holes 216b as the winding slots 214 in the stator core 210, the above configuration achieves the distribution of coolant in the circumferential channel 102 to each axial channel 217, thereby achieving efficient heat dissipation for both the stator core 210 and the stator winding 220. Of course, the above embodiments are merely exemplary. In embodiments not shown, each of the two sidewalls provided by the inner stator yoke 210b and the two sidewalls provided by the stator teeth 210c on both sides of each winding groove 214 can be in fluid communication with the circumferential channel 102 through a second distribution hole 216b. In this case, each second distribution hole 216b includes only one inner end, or any two of the three sidewalls can be in fluid communication with the circumferential channel 102 through a second distribution hole 216b. In this case, each second distribution hole 216b includes two inner ends.

[0054] refer to Figure 6 and Figure 7 ,in, Figure 6 A schematic cross-sectional view of a motor according to a third embodiment of the present disclosure is shown, and Figure 7 It shows along Figure 6 A schematic cross-sectional view of the motor stator taken by line VII-VII. Figure 6 and Figure 7 The third embodiment shown is the same as Figures 1-3The first embodiment shown and Figures 4-5 The second embodiment shown is largely the same, the main difference being that the dispensing holes 216 have different configurations. Specifically, as Figure 7 As shown in the enlarged view, the winding groove 214 does not include the enlarged portion 214e, and the multiple wires 221 in the winding groove 214 define multiple axial channels 217 with the sidewalls provided by the stator teeth 210c on one side of the winding groove 214, and the other wires 221 in the winding groove 214 define multiple axial channels 217 with the sidewalls provided by the stator teeth 210c on the other side of the winding groove 214. That is, the two sidewalls of the winding groove 214 provided by the stator teeth 210c on both sides define multiple axial channels 217 with the corresponding multiple wires 221, but the two sidewalls of the winding groove 214 provided by the outer stator yoke 210a and the inner stator yoke 210b are not used to define the axial channels 217. Furthermore, each distribution hole 216 opens to the circumferential channel 102 at its outer end. However, unlike the distribution holes 216 in the first and second embodiments, in the third embodiment, each distribution hole 216 has two inner ends, which are open on two sidewalls provided by two winding slots 214 on both sides of the corresponding stator tooth 210c. The distribution hole 216 is in fluid communication at each inner end with each axial channel 217 defined by the corresponding sidewall (i.e., the sidewall where the inner end is located). In this configuration, each axial channel 217 is defined by the sidewall provided by the stator tooth 210c and the corresponding wire 221. Each sidewall provided by the stator tooth 210c has an inner end of the corresponding distribution hole 216, and each distribution hole 216 opens at its inner end to each axial channel 217 defined by the corresponding sidewall. This allows each axial channel 217 to be in fluid communication with the circumferential channel 102 through the corresponding distribution hole 216. Therefore, the above configuration achieves efficient heat dissipation of the coolant in the circumferential channel 102 to each axial channel 217 simply by setting the same number of distribution holes 216 in the stator core 210 as the number of winding slots 214, thereby achieving efficient heat dissipation of both the stator core 210 and the stator winding 220.

[0055] like Figure 1 , Figure 4 and Figure 6 As shown, in the first to third embodiments, the motor 10 may further include an isolation cylinder 500 disposed within the housing 100. (See reference...) Figure 8 , which shows Figure 1 , Figure 4 and Figure 6The diagram shows a schematic perspective view of the isolation cylinder of the motor. As shown, the isolation cylinder 500 is generally cylindrical and positioned between the stator core 210 and the rotor core 310. The isolation cylinder 500 is positioned such that its two ends protrude axially relative to the two axial surfaces 211 of the stator core 210, such that a portion of the isolation cylinder 500 lies in the air gap between the stator core 210 and the rotor core 310, while its two ends lie on opposite sides of the stator core 210 along the axial direction. With this configuration, the isolation cylinder 500 reliably isolates the stator core 210 and the rotor core 310 from each other, thereby preventing coolant in the axial channel 217 from flowing into the air gap between the stator core 210 and the rotor core 310. This avoids the coolant exerting drag resistance on the high-speed rotating rotor 300, thereby improving the operating efficiency of the motor 10. Furthermore, since the two ends of the isolation cylinder 500 protrude axially relative to the two axial surfaces 211 of the stator core 210, the isolation cylinder 500 also helps to guide the coolant discharged from each axial channel 217 to the two winding heads 222, thereby promoting heat dissipation of the two winding heads 222 and further improving the heat dissipation effect of the stator winding 220. In particular, the isolation cylinder 500 is configured such that its radial outer surface can abut against the inner stator yoke 210b of the stator core 210, that is, it can fit against the radial inner surface 212 of the stator core 210. This allows the isolation cylinder 500 to be reliably positioned on the stator core 210, thereby preventing the rotor 300 from colliding or wearing with the isolation cylinder 500, thus ensuring the reliability and safety of the motor 10. Specifically, the two ends of the isolation cylinder 500 are spaced apart from the housing 100. That is, although the two ends of the isolation cylinder 500 protrude from the two axial surfaces 211 of the stator core 210, they are not connected to the housing 100. This leaves a larger channel between the isolation cylinder 500 and the housing 100 for the coolant in the chamber 105 to flow to the two drain holes 104, thereby promoting the circulation of coolant and further improving the heat dissipation effect of the stator core 210 and the stator winding 220.

[0056] refer to Figures 9-11 ,in, Figure 9 A schematic cross-sectional view of an electric motor according to a fourth embodiment of the present disclosure is shown. Figure 10 It shows Figure 9 The diagram shows a schematic perspective view of the stator core of the motor, and Figure 11 It shows along Figure 9 A schematic cross-sectional view of the motor stator taken by line XI-XI. Figures 9-11 The fourth embodiment shown is the same as Figures 1-3 The first embodiment shown is largely the same, the main difference being that the stator core 210 has a different configuration. Specifically, as Figures 9-11As shown, the stator core 210 does not have an inner stator yoke 210b, therefore each winding slot 214 does not have a sidewall provided by the inner stator yoke 210b, but only has a sidewall provided by the outer stator yoke 210a and the stator teeth 210c on both sides. In addition, each stator tooth 210c protrudes radially inward from the outer stator yoke 210a to its free end, and the free end of each stator tooth 210c forms a pole shoe 218, wherein each pole shoe 218 is spaced apart from other pole shoes 218 in the circumferential direction such that adjacent pole shoes 218 define a pole shoe gap 219 between each other, and each winding slot 214 can be opened toward the radially inward side of the stator core 210 (or the air gap between the stator core 210 and the rotor core 310) through the corresponding pole shoe gap 219. In this configuration, each winding slot 214 is closed radially outward by the outer stator yoke 210a, and open radially inward by the corresponding pole shoe gap 219, therefore Figures 9-11 The stator core 210 shown has a semi-closed slot configuration or a semi-open slot configuration. Specifically, as... Figure 10 As shown, the stator core 210 may include a plurality of stator laminations 210d stacked together along the axial direction and a distribution lamination 210e located between two stator laminations 210d, wherein each distribution hole 216 is formed in the distribution lamination 210e, and a circumferential channel 102 surrounds the distribution lamination 210e radially outward. More specifically, the radial dimension (i.e., radius or diameter) of the distribution lamination 210e is smaller than the radial dimension of the stator laminations 210d, such that the outer edge of the distribution lamination 210e is radially offset inward relative to the outer edge of the stator laminations 210d, thereby defining the circumferential channel 102 wholly or partially between the stator laminations 210d on both sides of the distribution lamination 210e.

[0057] refer to Figures 12-13 ,in, Figure 12 A schematic cross-sectional view of a motor according to a fifth embodiment of the present disclosure is shown, and Figure 13 It shows along Figure 12 A schematic cross-sectional view of the motor stator taken by line XIII-XIII. Figures 12-13 The fifth embodiment shown is the same as Figures 6-7 The third embodiment shown is largely the same, the main difference being that the stator core 210 has a different configuration. Specifically, as Figures 12-13As shown, the stator core 210 does not have an inner stator yoke 210b, therefore each winding slot 214 does not have a sidewall provided by the inner stator yoke 210b, but only has a sidewall provided by the outer stator yoke 210a and the stator teeth 210c on both sides. In addition, each stator tooth 210c protrudes radially inward from the outer stator yoke 210a to its free end, and the free end of each stator tooth 210c forms a pole shoe 218, wherein each pole shoe 218 is spaced apart from other pole shoes 218 in the circumferential direction such that adjacent pole shoes 218 define a pole shoe gap 219 between each other, and each winding slot 214 can be opened toward the radially inward side of the stator core 210 (or the air gap between the stator core 210 and the rotor core 310) through the corresponding pole shoe gap 219. In this configuration, each winding slot 214 is closed radially outward by the outer stator yoke 210a, and open radially inward by the corresponding pole shoe gap 219, therefore Figures 12-13 The stator core 210 shown is Figures 9-11 The stator core 210 shown has a semi-closed slot configuration or a semi-open slot configuration.

[0058] like Figure 9 and Figure 12As shown in the fourth and fifth embodiments, the motor 10 may also include an isolation cylinder 500 disposed within the housing 100. The isolation cylinder 500 is generally cylindrical and positioned between the stator core 210 and the rotor core 310. The isolation cylinder 500 is positioned such that its two ends protrude axially relative to the two axial surfaces 211 of the stator core 210, such that a portion of the isolation cylinder 500 is located in the air gap between the stator core 210 and the rotor core 310, while its two ends are located on opposite sides of the stator core 210 along the axial direction. With this configuration, the isolation cylinder 500 can reliably isolate the stator core 210 and the rotor core 310 from each other, thereby preventing coolant in the axial channel 217 from flowing into the air gap between the stator core 210 and the rotor core 310 through the respective pole shoe gaps 219. This avoids the coolant exerting drag resistance on the high-speed rotating rotor 300, thereby improving the operating efficiency of the motor 10. Furthermore, since the two ends of the isolation cylinder 500 protrude axially relative to the two axial surfaces 211 of the stator core 210, the isolation cylinder 500 also helps to guide the coolant discharged from each axial channel 217 to the two winding heads 222, thereby promoting heat dissipation of the two winding heads 222 and further improving the heat dissipation effect of the stator winding 220. In particular, the isolation cylinder 500 is configured such that its radial outer surface can abut against or fit against the pole shoe 218 of each stator tooth 210c, thereby reliably positioning the isolation cylinder 500 on the stator core 210, thereby preventing the rotor 300 from colliding or wearing with the isolation cylinder 500, thus ensuring the reliability and safety of the motor 10. Specifically, the two ends of the isolation cylinder 500 are spaced apart from the housing 100. That is, although the two ends of the isolation cylinder 500 protrude from the two axial surfaces 211 of the stator core 210, they are not connected to the housing 100. This leaves a larger channel between the isolation cylinder 500 and the housing 100 for the coolant in the chamber 105 to flow to the two drain holes 104, thereby promoting the circulation of coolant and further improving the heat dissipation effect of the stator core 210 and the stator winding 220.

[0059] like Figure 11 and Figure 13As shown in the fourth and fifth embodiments, the stator 200 may further include a plurality of sealing wedges 230, wherein each sealing wedge 230 is inserted into a corresponding pole shoe gap 219, and the cross-sectional shape of the sealing wedge 230 is complementary to the cross-sectional shape of the pole shoe gap 219. Furthermore, both ends of each sealing wedge 230 are flush with or protrude axially relative to the two axial surfaces 211 of the stator core 210, so that each sealing wedge 230 can completely fill the corresponding pole shoe gap 219. This isolates the corresponding winding slot 214 from the air gap between the stator core 210 and the rotor core 310, thereby preventing coolant in the axial channel 217 from flowing into the air gap between the stator core 210 and the rotor core 310, thus avoiding the coolant exerting drag resistance on the high-speed rotating rotor 300, thereby improving the operating efficiency of the motor 10. Specifically, each pole shoe gap 219 of the stator core 210 accommodates a sealing wedge 230, thereby more reliably preventing coolant in the axial channel 217 from flowing into the air gap between the stator core 210 and the rotor core 310. Specifically, refer to... Figure 14 , which shows Figure 9 and Figure 12 The diagram shown is a schematic perspective view of the stator of the motor, but for clarity, the stator windings are not shown. Figure 14 As shown, all or some of the multiple sealing wedges 230 of the stator 200 can be fixed on the radial outer surface of the isolation cylinder 500, thereby positioning the isolation cylinder 500 more reliably on the stator core 210, thus preventing the rotor 300 from colliding or wearing with the isolation cylinder 500, thereby ensuring the reliability and safety of the motor 10.

[0060] The foregoing has described in detail, with reference to the accompanying drawings, optional but non-limiting embodiments of the motor according to this disclosure. Modifications and additions to the technology and structure, as well as recombinations of features in the various embodiments, will be readily apparent to those skilled in the art without departing from the spirit and essence of this disclosure and should be considered within its scope. Therefore, all such modifications and additions conceivable under the teachings of this disclosure should be considered part of this disclosure. The scope of this disclosure includes equivalent technologies known at the filing date of this disclosure and equivalent technologies not yet foreseen.

Claims

1. An electric machine characterized in that, include: Casing (100); as well as A stator (200) is housed within the housing (100). The stator (200) includes a stator core (210) and a stator winding (220). The stator core (210) has a plurality of circumferentially spaced winding slots (214). Each winding slot (214) extends axially through the stator core (210) and accommodates a plurality of conductors (221) of the stator winding (220). The plurality of conductors (221) are stacked in the winding slot (214), and each conductor (221) and the sidewall of the winding slot (214) define an axial channel (217) extending axially through the stator core (210). The motor has a circumferential channel (102) arranged circumferentially and located radially outside the plurality of winding slots (214) within the housing (100), and The stator core (210) is also provided with a plurality of distribution holes (216), each distribution hole (216) having an outer end leading to the circumferential channel (102) and an inner end open on the side wall of the corresponding winding groove (214), so that each axial channel (217) is connected to the circumferential channel (102) through the corresponding distribution hole (216).

2. The electric machine of claim 1, wherein, The stator core (210) includes an outer stator yoke (210a), an inner stator yoke (210b) located radially inside the outer stator yoke (210a), and a plurality of stator teeth (210c) connecting the outer stator yoke (210a) and the inner stator yoke (210b). The plurality of stator teeth (210c) are circumferentially spaced apart from each other to define the plurality of winding slots (214). Each winding slot (214) has a sidewall provided by the outer stator yoke (210a), two sidewalls provided by the stator teeth (210c) on both sides, and a sidewall provided by the inner stator yoke (210b).

3. The electric machine of claim 2, wherein, The motor also includes a rotor (300) disposed radially inside the stator (200) and an isolation cylinder (500) disposed between the stator (200) and the rotor (300), the two ends of the isolation cylinder (500) being located on opposite sides of the stator core (210) along the axial direction.

4. The electric machine of claim 3, wherein, The isolation cylinder (500) abuts against the inner stator yoke (210b).

5. The electric machine of claim 3, wherein, The two ends of the isolation cylinder (500) are spaced apart from the housing (100).

6. The electric machine of claim 1, wherein, The stator core (210) includes an outer stator yoke (210a) and a plurality of stator teeth (210c) protruding inward from the outer stator yoke (210a). The plurality of stator teeth (210c) are circumferentially spaced apart to define a plurality of winding slots (214). Each winding slot (214) has a sidewall provided by the outer stator yoke (210a) and two sidewalls provided by the stator teeth (210c) on both sides. The free end of each stator tooth (210c) forms a pole shoe (218), and the pole shoes (218) of the plurality of stator teeth (210c) are spaced apart to define a plurality of pole shoe gaps (219).

7. The electric machine of claim 6, wherein, The stator (200) also includes a plurality of sealing wedges (230), each pole shoe gap (219) accommodating a corresponding sealing wedge (230) and being completely filled by the sealing wedges (230).

8. The motor according to claim 6, characterized in that, The motor also includes a rotor (300) disposed radially inside the stator (200) and an isolation cylinder (500) disposed between the stator (200) and the rotor (300), the two ends of the isolation cylinder (500) being located on opposite sides of the stator core (210) along the axial direction.

9. The electric machine of claim 8, wherein, The isolation cylinder (500) abuts against the pole shoe (218) of each stator tooth (210c).

10. The electric machine of claim 8, wherein, The two ends of the isolation cylinder (500) are spaced apart from the housing (100).

11. The electric machine of claim 8, wherein, The isolation cylinder (500) is provided with a plurality of sealing wedges (230) fixed on its radial outer surface, each sealing wedge (230) being inserted into and completely filling the corresponding pole shoe gap (219).

12. The electric machine of any of claims 1-11, wherein, Each winding slot (214) has a partially enlarged portion (214e) that forms an annular channel around all the wires (221) in the winding slot (214), and the inner end of each distribution hole (216) is open on the sidewall of the partially enlarged portion (214e) of the corresponding winding slot (214).

13. The electric machine of claim 12, wherein, Each distribution hole (216) is oriented radially.

14. The electric machine of any of claims 2-5, wherein, Each sidewall of each winding groove (214) defines an axial channel (217) with a corresponding wire (221) and is provided with an inner end of a distribution hole (216) leading to the axial channel (217).

15. The electric machine of claim 14, wherein, The plurality of distribution holes (216) include a plurality of first distribution holes (216a) and a plurality of second distribution holes (216b), the inner end of each first distribution hole (216a) being open on the sidewall of the corresponding winding groove (214) provided by the outer stator yoke (210a), and each second distribution hole (216b) having at least one inner end, the at least one inner end being open on at least one of the following: on the sidewall of the winding groove (214) on at least one side of the corresponding stator tooth (210c) and on the sidewall of one of the two winding grooves (214) on both sides of the corresponding stator tooth (210c) provided by the inner stator yoke (210b).

16. The electric machine of claim 15, wherein, Each first distribution hole (216a) is oriented radially.

17. The electric machine of any of claims 2-11, wherein, Each winding slot (214) has two sidewalls provided by stator teeth (210c) on both sides, which respectively define multiple axial channels (217) with corresponding multiple wires (221) and are provided with inner ends of distribution holes (216) leading to the multiple axial channels (217).

18. The electric machine of claim 17, wherein, Each distribution hole (216) has two inner ends, and the two inner ends are respectively open on two sidewalls provided by two winding slots (214) on both sides of the corresponding stator teeth (210c).

19. The electric machine of any one of claims 1-11, wherein, The radial outer surface (213) of the stator core (210) abuts against the inner surface (101) of the housing (100), and The circumferential channel (102) is formed by a groove recessed from the radial outer surface (213) of the stator core (210) and arranged circumferentially; or, The circumferential channel (102) is formed by a groove recessed from the inner surface (101) of the housing (100) and arranged circumferentially; or, The circumferential channel (102) consists of a groove recessed from the radial outer surface (213) of the stator core (210) and arranged circumferentially, and a groove recessed from the inner surface (101) of the housing (100) and arranged circumferentially.

20. The electric machine of claim 19, wherein, The housing (100) is provided with an extending liquid inlet (103) and two liquid outlets (104). The liquid inlet (103) is connected to the circumferential channel (102), and the two liquid outlets (104) are located on opposite sides of the stator core (210) along the axial direction.

21. The electric machine of any one of claims 1-11, wherein, Each conductor (221) is provided with a groove (221r) recessed from its surface and extending along its length, and is arranged in the winding groove (214) such that the surface with the groove (221r) abuts against the sidewall of the winding groove (214).

22. The electric machine of any one of claims 1-11, wherein, The stator core (210) includes a plurality of stator laminations (210d) stacked together along the axial direction and a distribution lamination (210e) located between two stator laminations (210d), each distribution hole (216) being formed in the distribution lamination (210e), and the circumferential channel (102) being formed on the radially outer side of the distribution lamination (210e).

23. The motor according to any one of claims 1-11, characterized in that, Each distribution hole (216) and the circumferential channel (102) are positioned at the midpoint of the stator core (210) along the axial direction.

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