Motor

Abstract

The utility model provides an electric machine. The motor (10) comprises a shell (100) and a stator (200) arranged in the shell (100), the stator (200) comprises a stator iron core (210), the stator iron core (210) is provided with a plurality of winding grooves (214) on the radial inner side, and a fluid path extending from the radial outer surface (213) of the stator iron core (210) to the bottom wall (214b) of each winding groove (214) is arranged in the stator iron core (210); and a stator winding (220), the stator winding (220) comprising a plurality of wire groups (222), each wire group (222) being inserted into one winding slot (214) and consisting of a plurality of wires (222a) stacked in the radial direction, and an axial channel (214c) extending in the axial direction through the winding slot (214) being formed between the radially outermost wire (222a) and a bottom wall (214b) of the winding slot (214).

Description

Technical Field

[0001] The present disclosure relates to the field of electric motors, and more particularly, to an electric motor with an improved liquid cooling design. Background Art

[0002] With the rapid development of motors, the power density and lightweight of motors have attracted more and more attention. However, the heat dissipation problem of motors has become the main factor restricting the further improvement of the power density of motors. Taking the common permanent magnet synchronous type motor as an example, the stator winding generates a rotating magnetic field after the alternating current is passed through it. The rotating magnetic field couples with the permanent magnet on the rotor to drive the rotor to rotate. However, at the same time, the rotating magnetic field will generate eddy currents in the rotor core and the stator core, causing the rotor core and the stator core to heat up, while the alternating current will cause the stator winding to heat up. Among them, the stator winding generates the most heat and is the most difficult to dissipate. In order to increase the power of the motor, a larger alternating current needs to be passed through the stator winding, but the heat generated by the stator core, stator winding and rotor core will also increase. If this heat cannot be effectively dissipated, it may shorten the service life of the motor or even cause the motor to overheat and burn. In the prior art, there are a variety of liquid cooling solutions to help the motor dissipate heat, including placing the stator core in a water jacket, machining cooling liquid channels in the stator core, etc. However, these liquid cooling solutions all have problems such as poor manufacturing feasibility, uneven heat absorption, and high manufacturing costs to a certain extent.

[0003] Therefore, in this field, there is an urgent need for a technical solution that can help the motor to dissipate heat effectively and has high manufacturing feasibility. Utility Model Content

[0004] In order to solve the above-mentioned problems in the prior art, the present disclosure proposes an electric motor with an improved liquid cooling design, which includes a shell and a stator arranged in the shell, characterized in that the stator includes: a stator core, the stator core is provided with a plurality of winding slots on the radial inner side and is provided with a fluid path extending from the radial outer surface of the stator core to the bottom wall of each winding slot; and a stator winding, the stator winding includes a plurality of wire groups, each wire group is inserted into a winding slot and consists of a plurality of wires stacked in the radial direction, and an axial channel extending axially through the winding slot is formed between the radially outermost wire and the bottom wall of the winding slot.

[0005] According to an optional embodiment of the present disclosure, the fluid path includes: a circumferential channel arranged circumferentially on the radial outside of the multiple winding slots; a plurality of radial channels connecting the circumferential channel with the multiple winding slots; and a liquid inlet hole extending from the radial outer surface of the stator core to the circumferential channel.

[0006] According to an optional embodiment of the present disclosure, the stator core includes a liquid separator ring stacked therein, and the circumferential channel, the plurality of radial channels and the liquid inlet hole are formed in the liquid separator ring.

[0007] According to an optional embodiment of the present disclosure, the liquid separator ring is axially centered in the stator core.

[0008] According to an optional embodiment of the present disclosure, the circumferential channel, the plurality of radial channels and the liquid inlet hole are axially centrally positioned in the stator core.

[0009] According to an optional embodiment of the present disclosure, the circumferential channel extends continuously in the circumferential direction through the entire circumference.

[0010] According to an optional embodiment of the present disclosure, the circumferential channel is composed of a plurality of circumferential segments, each circumferential segment is connected to the same number of winding slots, and the stator core is provided with a plurality of liquid inlet holes extending from its radial outer surface to the plurality of circumferential segments.

[0011] According to an optional embodiment of the present disclosure, each circumferential segment is isolated from each other.

[0012] According to an optional embodiment of the present disclosure, the radially outermost wire is provided with a groove extending axially in the radial outer surface, and the axial channel is at least partially constituted by the groove; and / or, the axial channel is at least partially constituted by the groove in the bottom wall of the winding slot; and / or, the conductor of the radially outermost wire is at least partially exposed in the axial channel; and / or, the radially outermost wire and any other one or any multiple wires in the wire group are provided with a groove extending axially; and / or, the radially outermost wire and any other one or any multiple wires in the wire group are provided with a groove extending axially, and the wire group is provided with an auxiliary radial channel connecting the groove with the axial channel.

[0013] According to an optional embodiment of the present disclosure, the stator further includes a plurality of insulating papers, each of which is inserted into a winding slot and surrounds the wire group and is provided with an opening constituting a portion of the axial channel.

[0014] According to an optional embodiment of the present disclosure, the stator core is further provided with a plurality of pole shoe gaps, each winding slot leads to the radial inner surface of the stator core through a pole shoe gap, and the stator core also includes a plurality of isolation strips inserted into the plurality of pole shoe gaps.

[0015] According to an optional embodiment of the present disclosure, each spacer bar is arranged to extend at least over the entire axial length of the stator core; and / or each pole shoe gap and each spacer bar are formed to have a cross-section that widens toward the radial outside.

[0016] According to an optional embodiment of the present disclosure, a top wall of each winding slot isolates the winding slot from a radial inner surface of the stator core.

[0017] According to an optional embodiment of the present disclosure, the shell internally defines two liquid collecting cavities located on both axial sides of the stator core, and the stator winding also includes at least one winding head connected to the multiple wire groups, and the winding head is accommodated in the liquid collecting cavity.

[0018] According to an optional embodiment of the present disclosure, the winding head is radially offset outward relative to the multiple wire groups so that each axial channel is axially aligned with at least a partial area of ​​the winding head; and / or, the motor also includes a rotor accommodated in the housing and arranged radially inward of the stator, and each liquid collecting chamber is isolated from the rotor; and / or, the housing is provided with a liquid inlet pipe connected to the fluid path and a liquid drain pipe connected to the liquid collecting chamber on its outer surface.

[0019] The present disclosure may be embodied as the illustrative embodiments in the accompanying drawings. However, it should be noted that the accompanying drawings are only illustrative, and any changes conceived under the teachings of the present disclosure should be considered to be included within the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings illustrate exemplary embodiments of the present disclosure. These drawings should not be interpreted as necessarily limiting the scope of the present disclosure, wherein:

[0021] Figure 1 is a schematic cross-sectional view of a motor according to an embodiment of the present disclosure;

[0022] Figure 2 yes Figure 1 A schematic perspective view of a stator core of the motor shown;

[0023] Figure 3 It is along Figure 1 A schematic three-dimensional diagram of the stator core of the motor taken along line AA;

[0024] Figure 4 It is along Figure 1 A schematic cross-sectional view of the stator core of the motor taken along line AA;

[0025] Figure 5 is a schematic cross-sectional view of a stator core of a motor according to another embodiment of the present disclosure;

[0026] Figure 6 It is along Figure 1 A schematic cross-sectional view of a portion of a stator of an electric machine taken along line AA in FIG.

[0027] Figure 7 is a schematic cross-sectional view of a portion of a stator of a motor according to another embodiment of the present disclosure;

[0028] Figure 8 is a schematic cross-sectional view of a portion of a stator of a motor according to another embodiment of the present disclosure;

[0029] Fig. 9 is a schematic cross-sectional view of a portion of a stator of a motor according to yet another embodiment of the present disclosure;

[0030] Fig.10 is a schematic cross-sectional view of a portion of a stator of a motor according to yet another embodiment of the present disclosure; and

[0031] Fig.11 is a schematic cross-sectional view of a motor according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] Further features and advantages of the present disclosure will become more apparent from the following description with reference to the accompanying drawings. Exemplary embodiments of the present disclosure are shown in the accompanying drawings, and the various drawings are not necessarily drawn to actual scale. However, the present disclosure can be implemented in many different forms and should not be interpreted as necessarily being limited to the exemplary embodiments disclosed herein. On the contrary, these exemplary embodiments are merely provided to illustrate the present disclosure and to convey the spirit and essence of the present disclosure to those skilled in the art.

[0033] The present disclosure aims to propose a motor with an improved liquid cooling design. According to the liquid cooling design of the present disclosure, the coolant can directly contact the stator winding and the stator core in each winding slot of the stator core, so that the stator core and the stator winding can be directly liquid cooled in each winding slot (referred to as direct cooling in the slot), thereby achieving effective heat dissipation of both the stator core and the stator winding. In particular, the liquid cooling design according to the present disclosure can also improve the balance of the cooling fluid pressure on the fluid path in each winding slot, which not only helps to achieve effective cooling of the stator core and the stator winding in each winding slot and over the entire length of each winding slot, but also reduces the requirements for supporting facilities such as hydraulic pumps so as to reduce the manufacturing cost of the cooling design according to the present disclosure. In addition, the liquid cooling design according to the present disclosure also has a high manufacturing feasibility, so it will not significantly increase the cost of the motor while helping the motor to achieve effective heat dissipation.

[0034] Various optional but non-limiting embodiments of the motor according to the present disclosure are described in detail below with reference to various drawings. As used herein, the term "axial" refers to a direction parallel to the rotation axis of the motor or a direction defined by the rotation axis of the motor, "radial" refers to a direction perpendicular to the rotation axis of the motor, and "circumferential" refers to a direction around the rotation axis of the motor. Unless otherwise expressly stated herein, these and other terms indicating orientation have their usual meanings in the art.

[0035] refer to Figure 1 , which shows a schematic cross-sectional view of a motor according to an embodiment of the present disclosure. Figure 1 As shown, the motor 10 generally includes a housing 100, a stator 200 fixedly disposed in the housing 100, and a rotor 300 rotatably disposed in the housing 100, wherein the stator 200 is disposed radially outside the rotor 300 and generally includes a stator core 210 and a stator winding 220 disposed on the stator core 210, and the rotor 300 generally includes a rotor core 310 and a plurality of permanent magnets (not shown) disposed on the rotor core 310. Figure 1 In the illustrated embodiment, the motor 10 is a permanent magnet synchronous type motor. During operation, an alternating current is passed through the stator winding 220, thereby generating a rotating magnetic field rotating around the rotation axis XX'. Under the guidance of the stator core 210, the rotating magnetic field is magnetically coupled with a plurality of permanent magnets on the rotor core 310, thereby driving the rotor core 310 to rotate around the rotation axis XX', thereby realizing the conversion of electrical energy into mechanical energy.

[0036] refer to Figure 2 , which shows Figure 1 Schematic three-dimensional diagram of the stator core of the motor shown. Figure 1 and Figure 2As shown, the stator core 310 is generally cylindrical, and has two axial surfaces 211 spaced apart from each other or opposite to each other in the axial direction and two radial surfaces 212, 213 spaced apart from each other or opposite to each other in the radial direction, wherein the two radial surfaces 212, 213 are composed of a radial inner surface 212 close to or facing the rotor 300 and a radial outer surface 213 away from or facing away from the rotor 300, wherein the two axial surfaces 211 are generally planes, and the two radial surfaces 212, 213 are generally cylindrical surfaces. In addition, the stator core 210 is provided with a plurality of winding grooves 214 on its radial inner side, and the winding grooves 214 are evenly arranged in the circumferential direction, and each winding groove 214 extends from one axial surface 211 of the stator core 210 to the other axial surface 211 in the axial direction, so that each winding groove 214 extends through the stator core 210 in the axial direction and is open on each axial surface 211 of the stator core 210. In addition, each winding slot 214 is defined by two side walls 214a opposite to each other along the circumferential direction and a bottom wall 214b connecting the two side walls 214a. In other words, each winding slot 214 is located between the two side walls 214a along the circumferential direction or is defined by the two side walls 214a and terminates at the bottom wall 214b along the radial direction, wherein each side wall 214a and the bottom wall 214b extend along the axial direction from one axial surface 211 of the stator core 210 to the other axial surface 211.

[0037] In particular, if Figure 2As shown, the stator core 210 is further provided with a plurality of pole shoe gaps 215 on its radial inner side, and these pole shoe gaps 215 are also evenly arranged along the circumferential direction, and each pole shoe gap 215 extends from one axial surface 211 of the stator core 210 to the other axial surface 211 along the axial direction, so that each pole shoe gap 215 extends through the stator core 210 along the axial direction and is open on each axial surface 211 of the stator core 210. In addition, each pole shoe gap 215 is also open on the radial inner surface 212 of the stator core 210, so that the radial inner surface 212 is divided into a plurality of sections distributed along the circumferential direction by the plurality of pole shoe gaps 215, and each pole shoe gap 215 is located radially inside a winding slot 214, so that each winding slot 214 leads to the radial inner surface 212 of the stator core 210 through a pole shoe gap 215. In this configuration, each winding slot 214 ends at the bottom wall 214b on the radial outer side, and leads to the radial inner surface 212 through the pole shoe gap 215 on the radial inner side, so the winding slot 214 is configured as a semi-open slot or a semi-closed slot. However, it should be pointed out that this configuration is only exemplary, and the stator core 210 may also not have any pole shoe gap 215, so that each winding slot 214 ends at the bottom wall 214b on the radial outer side and ends at the top wall 214d on the radial inner side ( Fig.10 That is, each winding groove 214 is located between the top wall 214d and the bottom wall 214b in the radial direction or is defined by the top wall 214d and the bottom wall 214b that are opposite to each other in the radial direction, so the winding groove 214 is constructed as a fully closed groove.

[0038] Back to Figure 1 The stator winding 220 includes at least one winding head 221 (for illustration only, the actual winding head may have various structures according to different types of wires) and a plurality of wire groups 222 connected to the winding head 221, wherein the winding head 221 is located outside the stator core 210, such as the axial end, and each wire group 222 is inserted into a winding slot 214 of the stator core 210 along the axial direction. That is, the stator winding 220 protrudes from both ends of the stator core 210 along the axial direction, and each winding slot 214 of the stator core 210 is provided with a wire group 222 extending through the axial direction. Each wire group 222 is composed of a plurality of wires 222a stacked together along the radial direction, that is, the plurality of wires 222a in each winding slot 214 are arranged in the winding slot 214 along the direction from the corresponding pole shoe gap 215 to the bottom wall 214b. Through the winding head 221, each wire 222a in each wire group 222 can be electrically connected in a specific manner so that the stator winding 220 can generate a desired rotating magnetic field when a specific alternating current is passed through it. Figure 1In the illustrated embodiment, the stator winding 220 includes two winding heads 221 or two groups of winding heads 221 respectively located on both sides of the stator core 210 along the axial direction, each group of winding heads may include a plurality of winding heads, and each wire group 222 is composed of four wires 222a, wherein each wire 222a is a flat wire, that is, the motor 10 is a flat wire motor. The flat wire may be a U-shaped wire, an X-shaped wire, an I-shaped wire, or the like.

[0039] As mentioned above, the conversion of electrical energy into mechanical energy is achieved by passing an alternating current through the stator winding 220 to generate a rotating magnetic field. Due to the rotating magnetic field, eddy currents are generated in the stator core 210 and the rotor core 310, and due to the resistance of the stator winding 220 itself, the stator core 210, the rotor core 310 and the stator winding 220 will all generate heat, and among them, the stator winding 220 generates the most heat and is the most difficult to dissipate. The heat dissipation problem of the stator winding 220 is one of the main constraints on the service life and performance improvement of the motor.

[0040] In order to achieve effective heat dissipation of the stator winding 220, the motor 10 has an improved liquid cooling design. Figure 3 and Figure 4 , which shows the Figure 1 A schematic perspective view and a schematic cross-sectional view of the stator core of the motor taken along line AA in FIG. Figure 1-Figure 4 As shown, the stator core 210 is provided with a generally annular circumferential channel 216 extending or arranged along the circumferential direction inside, and the circumferential channel 216 is located radially outside the plurality of winding slots 214. In addition, the stator core 210 is also provided with a plurality of radial channels 217 for fluidly connecting the circumferential channel 216 with the plurality of winding slots 214, and the plurality of radial channels 217 are evenly arranged along the circumferential direction, and each radial channel 217 extends substantially straight along the radial direction from the circumferential channel 216 to the bottom wall 214b of a winding slot 214, so that each winding slot 214 is fluidly connected with the circumferential channel 216 through the radial channel 217 located radially outside thereof. In addition, the stator core 210 is also provided with a liquid inlet 218 extending from its radial outer surface 213 or radial outer side along the radial direction to the circumferential channel 216, so that the coolant can be transported from the outside of the stator core 210 to the circumferential channel 216 through the liquid inlet 218. In this configuration, coolant from outside the motor 10 (for example, a coolant pump) can be delivered to the circumferential channel 216 along the radial direction through the inlet hole 218, and the coolant entering the circumferential channel 216 will flow in the circumferential direction in the circumferential channel 216 and be delivered to each winding groove 214 along the radial direction through each radial channel 217.

[0041] In particular, if Figure 2 and Figure 3 As shown, the stator core 210 is composed of a plurality of stator laminations 210a stacked and fixed (e.g., welded) together in the axial direction and a liquid separator ring 210b, each of the stator laminations 210a and the liquid separator ring 210b is generally annular in shape, and defines a plurality of notches 210c on the radial inner side thereof, which are intended to be aligned or aligned with each other in the axial direction to form a plurality of winding slots 214. In particular, the liquid separator ring 210b is positioned between two stator laminations 210a, and the circumferential channel 216, the radial channel 217 and the liquid inlet hole 218 are all formed in the liquid separator ring 210b. Under this configuration, it is only necessary to process a stator lamination 210a into a liquid separator ring 210b, and then stack it with other stator laminations 210a in the axial direction and fix it (e.g., welded) together to manufacture the stator core 210 having the liquid cooling design according to the present disclosure. Therefore, this configuration improves the manufacturing feasibility of the liquid cooling design according to the present disclosure, and thus reduces its manufacturing cost. In particular, the liquid separator ring 210b can be centrally positioned in the stator core 210 along the axial direction, that is, it can be located at half of the axial length of the stator core 210. Under this configuration, the coolant can enter the winding slot 214 from the middle of each winding slot 214, and then be discharged from both ends of the winding slot 214 after flowing in opposite directions through approximately the same axial distance, thereby balancing the coolant pressure balance along the axial direction in each winding slot 214. Of course, the above configuration is merely exemplary, and the stator core 210 can also be manufactured by other means, for example, additive manufacturing processes such as 3D printing and powder sintering.

[0042] In particular, if Figure 3 and Figure 4 As shown, the circumferential channel 216 extends continuously along the circumferential direction, that is, the circumferential channel 216 extends continuously through the entire circumference. In this configuration, only one liquid inlet hole 218 is required to provide cooling liquid to all winding slots 214 through the circumferential channel 216. However, this is only exemplary, and reference is made to FIG. Figure 5 , which shows a schematic cross-sectional view of a stator core of a motor according to another embodiment of the present disclosure. Figure 5As shown, the circumferential channel 216 is composed of a plurality of circumferential segments 216a, each of which extends through the same arc or has the same arc length, that is, the circumferential channel 216 is equally divided into a plurality of circumferential segments 216a along the circumferential direction, so that the number of winding slots 214 in fluid communication with each circumferential segment 216a through a plurality of radial channels 217 is the same. In addition, the stator core 210 is also provided with a plurality of liquid inlet holes 218, each of which is in fluid communication with a circumferential segment 216a, that is, each circumferential segment 216a can receive coolant through a liquid inlet hole 218. Under this configuration, each liquid inlet hole 218 can deliver coolant to the corresponding circumferential segment 216a, and the circumferential segment 216a in turn delivers coolant to the plurality of winding slots 214 in fluid communication with it. Therefore, Figure 3 and Figure 4 Compared to the embodiment shown, Figure 5 The illustrated embodiment can improve the balance of the cooling liquid pressure entering each winding groove 214 by providing a plurality of circumferential segments 216a and a plurality of liquid inlet holes 218, or can improve the balance of the cooling liquid pressure along the circumferential direction, thereby avoiding the situation where the winding groove 214 far away from the liquid inlet hole 218 cannot obtain sufficient cooling liquid pressure, so that each winding groove 214 can obtain sufficient cooling liquid pressure. In particular, each circumferential segment 216a of the circumferential channel 216 is fluidically isolated from each other. Under this configuration, the cooling liquid in any circumferential segment 216a cannot flow into other circumferential segments 216a, thereby avoiding mutual interference of the cooling liquid delivered to each circumferential segment 216a.

[0043] refer to Figure 6 , which shows the Figure 1 A schematic cross-sectional view of a portion of the stator of the motor taken along line AA in FIG. Figure 6As shown, in each winding slot 214, an axial channel 214c extending along the axial direction is formed between the wire 222a of the wire group 222 which is at the outermost side along the radial direction (i.e., closest to the bottom wall 214b of the winding slot 214) and the bottom wall 214b, and the axial channel 214c is fluidically connected to the corresponding radial channel 217 and extends along the axial direction across the entire axial length of the stator core 210 or at least extends along the entire axial length of the stator core 210, so that the axial channel 214c leads to both ends of the stator core 210 along the axial direction. Under this configuration, the coolant in the circumferential channel 216 can be transported to the axial channel 214 c in each winding groove 214 along the radial direction through each radial channel 217, and then flow in the opposite direction in the axial channel 214 c along the axial direction until it is discharged from both ends of the axial channel 214 c. That is, the liquid inlet hole 218, the circumferential channel 216 and each radial channel 217 together define a fluid path that guides the coolant to the axial channel 214 c in each winding groove 214. By means of this fluid path, the coolant can directly contact the radially outermost wire 222a in each winding slot 214 and over the entire axial length of the stator core 210, so that the coolant can absorb the heat generated by the radially outermost wire 222a, and because each wire 222a is a good thermal conductor, the other wires 222a will transfer heat to the radially outermost wire 222a, so that the coolant can absorb the heat generated by all wires 222a, thereby achieving in-slot direct cooling of each wire group 222 in each winding slot 214, which can significantly improve the heat dissipation of the stator winding 220. In addition, this configuration also allows the coolant to absorb the heat generated by the stator core 210 in each winding slot 214, thereby also improving the heat dissipation of the stator core 210.

[0044] In particular, if Figure 6As shown, the axial channel 214c is defined or constituted by the groove in the radially outermost wire 222a on its radial outer surface (i.e., the surface opposite to the bottom wall 214b). Under this configuration, it is only necessary to machine the above-mentioned groove on the surface of one wire 222a, and then insert the wire 222a into the winding slot 214 together with other wires 222a in a manner that the groove faces the bottom wall 214b of the winding slot 214, so as to form the above-mentioned axial channel 214c, thereby realizing the in-slot direct cooling of the stator core 210 and the stator winding 220. Therefore, this configuration improves the manufacturing feasibility of the liquid cooling design according to the present disclosure and reduces its manufacturing cost. More specifically, the insulating layer (e.g., the paint coating of the wire) of the radially outermost wire 222a in the above-mentioned groove can be removed. Under this configuration, the conductor (e.g., copper wire) of the radially outermost wire 222a is partially exposed to the axial channel 214c in the above-mentioned groove, so that the coolant in the axial channel 214c can directly contact the conductor in the groove, thereby improving the heat exchange efficiency between the coolant and the conductor, thereby further improving the heat dissipation of the stator winding 220.

[0045] In particular, refer to Figure 7 , which shows a schematic cross-sectional view of a portion of a stator of a motor according to another embodiment of the present disclosure. Figure 6 The embodiment shown differs in that Figure 7 In the illustrated embodiment, in each wire group 222, not only the radially outermost wire 222a is provided with a groove forming the axial channel 214c, but any other one or more wires 222a are also provided with grooves extending through in the axial direction, and these grooves can form auxiliary channels for the coolant to flow through, thereby further improving the heat dissipation of the stator winding 220. More specifically, in Figure 7 In the illustrated embodiment, in each wire group 222, each wire 222a is provided with a groove extending through the wire in the axial direction, but this is merely schematic. It should be noted that the design of the groove needs to meet the insulation performance between the wires 222a in the wire group 222, for example, by considering the creepage distance, ensuring that the exposed metal parts on adjacent wires 222a are spaced apart by a sufficient distance to ensure the minimum electrical clearance, thereby obtaining sufficient insulation performance and preventing leakage or short circuit.

[0046] In particular, refer to Figure 8 , which shows a schematic cross-sectional view of a portion of a stator of a motor according to another embodiment of the present disclosure. Figure 6 The embodiment shown differs in that Figure 8In the illustrated embodiment, in each wire group 222, not only the radially outermost wire 222a is provided with a groove forming the axial channel 214c, but any other one or more wires 222a are also provided with a groove extending through the axial direction, and the wire group 222 is provided with an auxiliary radial channel 222b (for example, it can be composed of a through hole in the corresponding wire 222a) for fluidly connecting these grooves with the axial channel 214c. The auxiliary radial channel 222b can guide the coolant in the axial channel 214c to these grooves, so that these grooves form auxiliary axial channels for the coolant to flow through, thereby further improving the heat dissipation of the stator winding 220. More specifically, in Figure 8 In the illustrated embodiment, in each wire group 222, each wire 222a is provided with a groove extending through it in the axial direction, and except for the radially innermost wire 222a, each wire 222a is provided with a through hole to form an auxiliary radial channel 222b, but this is only for illustration. It should be noted that the design of the groove and the auxiliary radial channel 222b needs to meet the insulation performance between the wires 222a in the wire group 222.

[0047] In particular, refer to Fig. 9 , which shows a schematic cross-sectional view of a portion of a stator of a motor according to yet another embodiment of the present disclosure. Figure 6 , Figure 7 and Figure 8 The embodiment shown differs in that Fig. 9 In the illustrated embodiment, the axial channel 214c is defined or constituted by a groove in the bottom wall 214b of the winding slot 214. Under this configuration, the above-mentioned axial channel 214c can be formed by only machining the above-mentioned groove on the bottom wall 214b of each winding slot 214, thereby realizing direct cooling in the slot of the stator core 210 and the stator winding 220. Therefore, this configuration can also improve the manufacturing feasibility of the liquid cooling design according to the present disclosure and reduce its manufacturing cost. More specifically, in this embodiment, all or part of the insulating layer on the radial outer surface of the radially outermost wire 222a can also be removed, so that the coolant in the axial channel 214c can directly contact the conductor of the wire 222a, thereby further improving the heat dissipation of the stator winding 220.

[0048] In particular, if Figure 6-Figure 9As shown, the stator 200 also includes a plurality of insulating papers 230, each of which is inserted into a winding slot 214 along the axial direction and surrounds the wire group 222 in the winding slot 214 so as to separate the wire group 222 from the stator core 210. In this configuration, the insulating paper 230 can be used to improve the insulation between the stator core 210 and the stator winding 220, thereby improving the reliability of the motor 10. In particular, each insulating paper 230 is also provided with or has an opening 231 extending along the axial direction, and the opening 231 constitutes or defines a part of the axial channel 214c, thereby allowing the coolant to pass through the opening 231 and directly contact the radially outermost wire 222a. In this configuration, the insulating paper 230 can improve the insulation between the stator core 210 and the stator winding 220 without adversely affecting the direct cooling in the slots of the two. Of course, Figure 6-Figure 9 The illustrated embodiments may be combined such that the axial passage 214 c is defined by grooves in the radially outer surface of the radially outermost wire 222 a , grooves in the bottom wall 214 b of the winding slot 214 , and / or the opening 231 of the insulating paper 230 .

[0049] In particular, if Figure 6-Figure 9 As shown, the stator 200 further includes a plurality of spacer bars 240, each spacer bar 240 being inserted into a pole shoe gap 215 along the axial direction, so that each pole shoe gap 215 is filled or blocked by a spacer bar 240. Under this configuration, each spacer bar 240 can close the corresponding winding slot 214 along the radial direction, so as to fluidly isolate each winding slot 214 from the rotor 300, thereby preventing the coolant in each winding slot 214 from entering the air gap between the stator 200 and the rotor 300, thereby preventing the coolant from increasing the rotation resistance of the rotor 300, thereby helping to maintain the efficiency of the motor 10. In particular, each spacer bar 240 is arranged to extend across the entire axial length of the stator core 210 along the axial direction or at least extend over the entire axial length of the stator core 210. In this configuration, each isolation bar 240 can close the corresponding winding slot 214 over the entire axial length of the winding slot 214, thereby more reliably preventing the coolant from entering the air gap between the stator 200 and the rotor 300. In particular, each pole shoe gap 215 and each isolation bar 240 are formed to have a cross section that widens toward the radial outside, such as a wedge or dovetail shape. In this configuration, the stator core 210 can prevent each isolation bar 240 from moving radially inward toward the rotor 300, thereby preventing the isolation bar 240 and the rotor 300 from contacting each other, thereby preventing the wear and tear of the two from being aggravated or even damaged.

[0050] refer to Fig.10 , which shows a schematic cross-sectional view of a portion of a stator of an electric machine according to yet another embodiment of the present disclosure. Fig.10 The embodiment shown is Figure 1-Figure 9 The difference of the illustrated embodiment is that the stator core 210 is not provided with any pole shoe gap 215, and therefore no spacer bar 240 is required. In this configuration, each winding slot 214 is defined by two side walls 214a in the circumferential direction and by a bottom wall 214b and a top wall 214d in the radial direction, so that each winding slot 214 is separated from the radial inner surface 212 of the stator core 210 by its top wall 214d, thereby being configured as a fully closed slot. Therefore, this configuration can more reliably prevent the coolant from entering the air gap between the stator 200 and the rotor 300, and there is no risk of the spacer bar 240 and the rotor 300 contacting each other.

[0051] In particular, back to Figure 1 and Figure 2 , the circumferential channel 216 (or each circumferential segment 216a), each radial channel 217 and the liquid inlet hole 218 (or each liquid inlet hole 218) can be centrally positioned in the stator core 210 along the axial direction, that is, can be positioned at half of the axial length of the stator core 210. Under this configuration, the coolant can enter from the middle of each axial channel 214c, and then be discharged from both ends of the axial channel 214c after flowing in opposite directions through approximately the same axial distance, thereby improving the balance of the coolant pressure on each axial channel 214c, or improving the balance of the coolant pressure along the axial direction. More specifically, if the above configuration is combined with Figure 5 In combination with the configuration shown, the balance of the coolant pressure in the axial direction and the balance in the circumferential direction are improved, which can further improve the heat dissipation of the stator core 210 and the stator winding 220 .

[0052] Continue to refer Figure 1 and Figure 2In particular, the housing 100 defines two liquid collecting chambers 100c located on both sides of the stator core 210 along the axial direction, and the winding heads 221 of the stator winding 220 can be accommodated in the liquid collecting chambers 100c. Under this configuration, the axial channel 214c in each winding slot 214 leads to the two liquid collecting chambers 100c at both ends thereof, so that the coolant discharged from both ends of each axial channel 214c can be collected in the two liquid collecting chambers 100c, and the coolant collected in the liquid collecting chamber 100c can directly contact the winding heads 221, thereby helping the winding heads 221 to dissipate heat, thereby further improving the heat dissipation of the stator winding 220. In particular, the winding head 221 radially extends or bends as it moves away from the stator core 210, that is, the winding head 221 is radially offset outward relative to each wire group 222, so that the axial channel 214c in each winding slot 214 can be aligned with at least a portion of the winding head 221 along the axial direction. In this configuration, if the coolant has sufficient pressure, the coolant discharged from both ends of each axial channel 214c can be directly sprayed onto the winding head 221, thereby more effectively helping the winding head 221 to dissipate heat, thereby further improving the heat dissipation of the stator winding 220.

[0053] In particular, if Figure 1 As shown, the housing 100 may be provided with an inlet pipe 100i and two discharge pipes 100e on its outer surface, the inlet pipe 100i defining a lumen in fluid communication with the inlet hole 218, and each discharge pipe 100e defining a lumen in fluid communication with a liquid collecting chamber 100c. In this configuration, the coolant from the outside (e.g., a coolant pump) may be delivered to the motor 10 through the inlet pipe 100i, and then flow in the stator 200 along the fluid path as described above to cool the stator core 210 and the stator winding 220, and then be discharged into the two liquid collecting chambers 100c, and finally be discharged from the motor 10 through the two discharge pipes 100e. Of course, in Figure 5 In the illustrated embodiment, the housing 100 may be provided with a plurality of liquid inlet tubes 100i on its outer surface, each of which defines a lumen in fluid communication with a liquid inlet hole 218 so that each liquid inlet hole 218 can receive cooling liquid from a corresponding liquid inlet tube 100i.

[0054] In particular, if Figure 1As shown, the motor 10 further includes a substantially cylindrical separating cylinder 400 disposed in the housing 100, the separating cylinder 400 being arranged between the stator 200 and the rotor 300, and having both ends connected to the housing 100, thereby isolating each liquid collecting chamber 100c from the fluid of the rotor 300. In this configuration, the separating cylinder 400, the housing 100 and the stator 200 define each liquid collecting chamber 100c as an annular chamber surrounding the rotor 300 on the radially outer side of the rotor 300 and is fluidically isolated from the rotor 300. Therefore, in this configuration, no matter in which direction the motor 10 is positioned, even if the motor 10 is positioned so that the drain pipe 100e faces upward, the coolant in the liquid collecting chamber 100c can be prevented from contacting the rotor 300, thereby preventing the coolant from increasing the rotation resistance of the rotor 300, so as to more reliably maintain the efficiency of the motor 10.

[0055] refer to Fig.11 , which shows a schematic cross-sectional view of a motor according to yet another embodiment of the present disclosure. Fig.11 The embodiment shown is Figure 1 The difference between the embodiment shown is that both ends of the isolation cylinder 400 are separated from the housing 100, so that each liquid collecting chamber 100c is semi-isolated from the rotor 300 instead of being semi-isolated from the rotor 300 as shown in FIG. Figure 1 In this configuration, the motor 10 only needs to be positioned so that the drain pipe 100e faces downward, and the coolant in each liquid collecting chamber 100c can be discharged in time through the drain pipe 100e, thereby avoiding the accumulation of coolant in each liquid collecting chamber 100c, thereby also avoiding the coolant from contacting the rotor 300, so as to reliably maintain the efficiency of the motor 10.

[0056] The optional but non-limiting embodiments of the motor according to the present disclosure are described in detail above with the aid of the accompanying drawings. For those of ordinary skill in the art, without departing from the spirit and substance of the present disclosure, modifications and supplements to the technology and structure and the re-combination of the features in each embodiment should obviously be considered to be included in the scope of the present disclosure. Therefore, these modifications and supplements that can be conceived under the teachings of the present disclosure should be considered as part of the present disclosure. The scope of the present disclosure includes equivalent technologies known at the filing date of the present disclosure and equivalent technologies that have not yet been foreseen.

Claims

1. A motor comprising a housing (100) and a stator (200) arranged in the housing (100), characterized in that: The stator (200) comprises: A stator core (210) having a plurality of winding slots (214) disposed radially inwardly and having a fluid path extending from a radially outer surface (213) of the stator core (210) to a bottom wall (214b) of each winding slot (214) disposed therein; and A stator winding (220) includes a plurality of wire groups (222), each wire group (222) is inserted into a winding slot (214) and is composed of a plurality of wires (222a) stacked in a radial direction, and an axial channel (214c) extending axially through the winding slot (214) is formed between the radially outermost wire (222a) and the bottom wall (214b) of the winding slot (214).

2. The motor according to claim 1, characterized in that The fluid path comprises: a circumferential channel (216) arranged circumferentially on the radial outer side of the plurality of winding slots (214); a plurality of radial channels (217) connecting the circumferential channel (216) with the plurality of winding slots (214); and a liquid inlet hole (218) extending from the radial outer surface (213) of the stator core (210) to the circumferential channel (216).

3. The motor according to claim 2, characterized in that The stator core (210) includes a liquid separator ring (210b) stacked therein, and the circumferential channel (216), the plurality of radial channels (217) and the liquid inlet hole (218) are formed in the liquid separator ring (210b).

4. The motor according to claim 3, characterized in that The liquid separator ring (210b) is centrally positioned in the stator core (210) along the axial direction.

5. The motor according to claim 2, characterized in that: The circumferential channel (216), the plurality of radial channels (217) and the liquid inlet hole (218) are centrally positioned in the stator core (210) along the axial direction.

6. The motor according to any one of claims 2 to 5, characterized in that: The circumferential channel (216) extends continuously in the circumferential direction through the entire circumference.

7. The motor according to any one of claims 2 to 5, characterized in that: The circumferential channel (216) is composed of a plurality of circumferential segments (216a), each circumferential segment (216a) is connected to the same number of winding slots (214), and the stator core (210) is provided with a plurality of liquid inlet holes (218) extending from its radial outer surface (213) to the plurality of circumferential segments (216a).

8. The motor according to claim 7, characterized in that Each circumferential segment (216a) is isolated from each other.

9. The motor according to any one of claims 1 to 5, characterized in that: The radially outermost conductor (222a) is provided with a groove extending axially in the radial outer surface, and the axial passage (214c) is at least partially constituted by the groove; and / or The axial passage (214c) is at least partially formed by a groove in the bottom wall (214b) of the winding groove (214); and / or The conductor of the radially outermost wire (222a) is at least partially exposed in the axial passage (214c); and / or The radially outermost wire (222a) and any other one or more wires (222a) in the wire group (222) are provided with a groove extending through the wire in the axial direction; and / or The radially outermost wire (222a) and any other one or more wires (222a) in the wire group (222) are provided with a groove extending axially therethrough, and the wire group (222) is provided with an auxiliary radial channel (222b) connecting the groove with the axial channel (214c).

10. The motor according to any one of claims 1 to 5, characterized in that: The stator (200) further comprises a plurality of insulating papers (230), each insulating paper (230) being inserted into a winding slot (214) and surrounding the wire group (222), and being provided with an opening (231) constituting a part of the axial channel (214c).

11. The motor according to any one of claims 1 to 5, characterized in that: The stator core (210) is also provided with a plurality of pole shoe gaps (215), each winding slot (214) leads to the radial inner surface (212) of the stator core (210) through a pole shoe gap (215), and the stator core (210) further includes a plurality of isolation bars (240) inserted into the plurality of pole shoe gaps (215).

12. The motor according to claim 11, characterized in that Each spacer bar (240) is arranged to extend at least over the entire axial length of the stator core (210); and / or Each pole piece gap (215) and each isolation bar (240) are formed to have a cross section that widens toward the radial outside.

13. The motor according to any one of claims 1 to 5, characterized in that: A top wall (214d) of each winding slot (214) isolates the winding slot (214) from a radial inner surface (212) of the stator core (210).

14. The motor according to any one of claims 1 to 5, characterized in that: The housing (100) defines two liquid collecting chambers (100c) located on both axial sides of the stator core (210) inside, and the stator winding (220) further comprises at least one winding head (221) connected to the plurality of wire groups (222), and the winding head (221) is accommodated in the liquid collecting chamber (100c).

15. The motor according to claim 14, characterized in that The winding head (221) is radially offset outward relative to the plurality of wire groups (222) so that each axial channel (214c) is axially aligned with at least a partial area of ​​the winding head (221); and / or The motor (10) further comprises a rotor (300) accommodated in the housing (100) and arranged radially inward of the stator (200), and each liquid collecting chamber (100c) is isolated from the rotor (300); and / or The housing (100) is provided on its outer surface with a liquid inlet pipe (100i) communicating with the fluid path and a liquid discharge pipe (100e) communicating with the liquid collecting chamber (100c).

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