Stator core and rotating electric machine
The stator core with integrated refrigerant pathways effectively addresses eddy current-induced heating and assembly challenges, enhancing cooling performance and reducing complexity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- KK TOSHIBA
- Filing Date
- 2025-09-11
- Publication Date
- 2026-05-11
AI Technical Summary
Eddy current losses in the stator's metal core cause excessive temperature rise, which affects the armature coil, and coreless designs complicate assembly and positioning, requiring additional cooling methods that increase complexity and parts.
A stator core design with end-extended core portions and integrated refrigerant pathways for efficient cooling, including header and tooth section flow paths, refrigerant inlets and outlets, and refrigerant reservoirs to enhance cooling performance.
The design improves cooling efficiency, reduces eddy current losses, maintains manufacturing accuracy, and facilitates miniaturization and weight reduction while ensuring effective cooling of the armature coil and magnetic shielding cover.
Smart Images
Figure 2026076112000001_ABST
Abstract
Description
Technical Field
[0002] , ,
[0004] , , , , ,
[0006] , , ,
[0005] , ,
[0007] , , ,
[0003]
[0001] Embodiments of this invention relate to a stator core of a rotating electrical machine and a rotating electrical machine.
Background Art
[0002] An example of the structure of a conventional rotating electrical machine will be described using FIGS. 12 and 13.
[0003] FIG. 12 is a diagram showing an example of a cross-sectional shape when a conventional rotating electrical machine is viewed in the axial direction. FIG. 13 is a diagram showing an example of a cross-sectional shape when the conventional rotating electrical machine shown in FIG. 12 is viewed in the circumferential direction.
[0004] The rotating electrical machine corresponds to, for example, an electric motor or a generator, and includes a stator 10 and a rotor 20, which are arranged concentrically. The rotor 20 rotates about a rotation axis 30. The rotor 20 is arranged at a certain distance from the stator 10, and a certain gap is provided between the stator 10 and the rotor 20. <00000!6>
[0005] Slots 11 are provided in the stator 10 at regular intervals in the circumferential direction, and armature coils 12 are provided in the individual slots 11. An insulator (not shown) is provided between the slots 11 and the armature coils 12, and a wedge (not shown) for preventing the armature coils 12 from protruding is also provided.
[0006] Also, FIG. 12 shows an example of a form in which the individual coil pieces constituting the armature coil 12 are laminated in the radial direction of the rotating electrical machine within the slots 11, but there is also a form in which they are arranged dispersedly within the slots 11.
[0007] The stator core 10A in the stator 10 is composed of an annular core back portion and tooth portions arranged on the inner diameter side of this core back portion. A magnetic shielding cover (magnetic shield) 50 is provided on the outer peripheral side of the core back portion. The above-described slots 11 are formed between adjacent tooth portions. In the slots 11, the individual coil pieces of the armature coil 12 are housed in a state of being insulated by an insulator.
[0008] Conventionally, the stator core 10A of a rotating electric machine, such as the stator core of an electric motor or generator, mainly uses metal as its material. The stator core is made of a soft magnetic material such as electromagnetic steel sheet, and forms a bulk body or a laminated structure by stacking them.
[0009] The main role and effect of the stator core is to act as a path for the magnetic field generated inside the rotating electric machine, thereby providing driving force. Since iron conducts magnetic fields approximately 1000 times more easily than air, using a core allows for efficient transfer of magnetic flux between the rotor and the armature coils of the stator, reducing leakage flux and increasing driving force.
[0010] The stator core not only provides electrical effects but also plays an important role in structural design. Specifically, the stator core has multiple slots 11 arranged circumferentially, mainly on the inner diameter side of its structure. The armature coils 12 are housed in these slots, thereby providing resistance to external stresses such as vibrations that the stator, which is assembled from all its components, is subjected to, and improving its mechanical strength.
[0011] Furthermore, the stator core serves as a reference for the relative positional relationships between various parts, such as gaps, as well as for positioning such as concentricity and shaft alignment. This helps to reduce manufacturing dimensional tolerances when assembling electric motors or generators, thereby promoting improved accuracy. [Prior art documents] [Patent Documents]
[0012] [Patent Document 1] Japanese Patent Publication No. 2014-093827 [Overview of the project] [Problems that the invention aims to solve]
[0013] Depending on the type of rotating electric machine, the stator may experience a large magnetic field from the rotor. In such cases, eddy current losses in the stator's metal core become excessive, causing the temperature to rise. Specifically, when using an electrical conductor such as metal or laminated electrical steel sheets in the stator core of an electric motor or generator equipped with a certain type of rotor, the loss causes the temperature to rise, thermally affecting the armature coil of the stator, which has temperature limitations, posing a significant problem.
[0014] On the other hand, one could consider adopting a coreless design for this type of electric motor, eliminating the core around the armature coil to avoid heat generation due to eddy currents in that area. However, adopting a coreless design would make assembly difficult, such as determining dimensions and positioning during manufacturing, and would require assembly jigs, raising concerns about increased processing time.
[0015] One possible solution to the above problem is to employ a core made of a material that does not generate or can reduce eddy current losses. Since electrical conductivity is strongly correlated with eddy current losses, eddy current losses can be suppressed by using a material with low or zero electrical conductivity, such as a non-metallic material (such as a resin). While this makes it possible to suppress eddy current losses, the aforementioned non-metallic materials (such as resins) generally have lower thermal conductivity than metallic materials. Therefore, without some ingenuity, the heat transmitted and released through the core using the armature coil as a heat source may cause an excessive temperature rise inside or around the armature coil.
[0016] Furthermore, when such materials are used to construct the core, a magnetic shielding cover 50 is required to cover the outer circumference of the stator core 10A, as shown in Figure 13, in order to prevent magnetic leakage to the outside. Eddy currents are generated in this magnetic shielding cover 50, causing it to generate heat, which can lead to an excessive temperature rise in the magnetic shielding cover and its surroundings.
[0017] To solve this problem, methods for cooling the inner or outer diameter side of the stator can be considered, such as forced air cooling with auxiliary equipment like a fan, or self-cooling, where airflow generated by the rotation of the motor is facilitated by an outer shell structure with irregularities. However, both methods involve the installation of auxiliary equipment and the burden on structural design. Furthermore, depending on the location and environment in which the motor is installed, miniaturization and weight reduction may be required, and the number of parts must be kept to a minimum while ensuring the required characteristics of the motor.
[0018] This invention has been made in view of the above circumstances, and aims to provide a stator core for a rotating electric machine and a rotating electric machine that can improve cooling performance with a simple configuration. [Means for solving the problem]
[0019] The stator core of a rotating electric machine according to this embodiment comprises an annular core back portion and a plurality of teeth portions extending toward the inner diameter side of the core back portion, and further a magnetic shielding cover is provided on the outer circumference side of the core back portion, the stator core of a rotating electric machine comprising: first and second end-extended core portions having a structure in which each of the axial ends of the stator core is extended toward the outer diameter side; refrigerant inlet and refrigerant outlet provided in the first and second end-extended core portions, respectively; first and second header passages provided in each of the first and second end-extended core portions and formed so that the refrigerant flows in the circumferential direction; and the plurality of teeth The device comprises toothed section flow paths formed so that the refrigerant flows axially within each section, a plurality of toothed section inlets connecting the first header flow path and the toothed section flow paths, and a plurality of toothed section outlets connecting the toothed section flow paths and the second header flow path. The device is configured such that the refrigerant supplied from the outside flows in through the refrigerant inlets, sequentially through the refrigerant inlets, the first header flow path, the plurality of toothed section inlets, the toothed section flow paths, the plurality of toothed section outlets, the second header flow path, and the refrigerant outlet, and flows out to the outside through the refrigerant outlets. [Effects of the Invention]
[0020] According to the present invention, it is possible to provide a stator core of a rotating electrical machine and a rotating electrical machine that can improve the cooling performance with a simple configuration.
Brief Description of the Drawings
[0021] [Figure 1] FIG. 1 is a perspective view showing a part of a stator of a rotating electrical machine according to an embodiment. [Figure 2] FIG. 2 is an axial cross-sectional view showing an example of a cross-sectional shape when a part of the stator of the rotating electrical machine shown in FIG. 1 is viewed in the circumferential direction. [Figure 3] FIG. 3 is a view showing a cross-sectional shape of a part including the first end extended core portion 15 of the stator core 10A. [Figure 4] FIG. 4 is a view showing a cross-sectional shape of the central portion of the stator core 10A. [Figure 5] FIG. 5 is an axial cross-sectional view showing an example of another cross-sectional shape when a part of the stator of the rotating electrical machine shown in FIG. 1 is viewed in the circumferential direction. [Figure 6] FIG. 6 is a view showing a modified example of the shape of the refrigerant reservoir portion 66 shown in FIG. 5. [Figure 7] FIG. 7 is a view showing a first modified example of the refrigerant inlet 61. [Figure 8] FIG. 8 is a view showing a second modified example of the refrigerant inlet 61. [Figure 9] FIG. 9 is a view showing a modified example of the first header flow path 63. [Figure 10] FIG. 10 is a graph in which the "flow velocity distribution" of the refrigerant is superimposed and displayed on an axial cross-sectional view of a part of the stator 10. [Figure 11] FIG. 11 is a graph in which the "temperature distribution" of the refrigerant is superimposed and displayed on an axial cross-sectional view of a part of the stator 10. [Figure 12] FIG. 12 is a view showing an example of a cross-sectional shape when a conventional rotating electrical machine is viewed in the axial direction. [Figure 13] FIG. 13 is a view showing an example of a cross-sectional shape when the conventional rotating electrical machine shown in FIG. 12 is viewed in the circumferential direction. [Modes for carrying out the invention]
[0022] The embodiments will be described below with reference to the drawings. Figure 12, mentioned earlier, will also be referenced here.
[0023] (composition) The basic structure of the rotating electric machine according to this embodiment is the same as that described in Figure 12. However, the structure of the stator core is different from that of the conventional one. The following will focus on the parts that differ from the conventional structure described above.
[0024] Figure 1 is a perspective view showing a part of the stator of a rotating electric machine according to an embodiment. Figure 2 is an axial cross-sectional view showing an example of the cross-sectional shape of a part of the stator of the rotating electric machine shown in Figure 1 when viewed in the circumferential direction.
[0025] The structure shown in Figure 1 is part of the stator 10. In reality, a single stator 10 is formed by connecting multiple structures identical to those in Figure 1 in the circumferential direction. The example of the structure shown in Figure 1 illustrates a case where there are six teeth 13.
[0026] The stator core 10A of the rotating electric machine according to this embodiment has a basic structure comprising an annular core back portion 14 and a plurality of teeth portions 13 extending radially from the core back portion 14, and further comprises a magnetic shielding cover (magnetic shield) 50 on the outer circumference of the core back portion 14 that blocks magnetism from moving from the inside to the outside.
[0027] Furthermore, the stator core 10A includes first and second end-extended core portions 15, each having a structure in which the axial ends of the stator core 10A are extended outwards. The first and second end-extended core portions 15 are arranged to sandwich the magnetic shielding cover 50 from both its axial ends.
[0028] Furthermore, the first and second end extension core portions 15 are provided with first and second header flow paths 63, respectively. The first and second header flow paths 63 are formed so that the refrigerant flows in the circumferential direction. In Figure 1, for convenience, a cross-section of the first header flow path 63 is shown.
[0029] Furthermore, the outer diameter side of each of the first and second end-extension core portions 15 is provided with a refrigerant inlet 61 through which refrigerant supplied from the outside flows in, and a refrigerant outlet 62 through which refrigerant flows out to the outside.
[0030] Figure 2 shows the aforementioned magnetic shielding cover 50, as well as the tooth section flow path 60, tooth section inlet 64, tooth section outlet 65, etc., which are located inside the stator core 10A. These will be explained later.
[0031] Figure 3 shows the cross-sectional shape of the portion of the stator core 10A that includes the first end extension core portion 15. The cross-sectional shape of the portion of the stator core 10A that includes the second end extension core portion 15 is the same as in Figure 3, so it is not shown here. Figure 4 shows the cross-sectional shape of the central portion of the stator core 10A.
[0032] Figures 3 and 4 show the aforementioned refrigerant inlet 61 and the first header flow path 63. In addition, the teeth section flow path 60, teeth section inlet 64, and refrigerant reservoir 66, which will be described later, are also shown. Figure 4 shows the teeth section flow path 60 and the refrigerant reservoir 66.
[0033] Each slot of the stator 10 is provided with an armature coil 12. An insulator 17 is provided between the slot 11 and the armature coil 12, and a wedge 16 is also provided to prevent the armature coil 12 from popping out.
[0034] As can be seen from Figures 2 to 4, each of the multiple tooth sections 13 is provided with a tooth section flow path 60 that is open to allow the refrigerant to flow in the axial direction. Furthermore, multiple tooth section inlets 64 are provided to connect the first header flow path 63 and the tooth section flow path 60, and multiple tooth section outlets 65 are provided to connect the tooth section flow path 60 and the second header flow path 63.
[0035] In this configuration, the refrigerant supplied from the outside flows in through the refrigerant inlet 61, then sequentially through the first header flow path 63 provided in the first end expansion core section 15, the multiple tooth section inlets 64, the tooth section flow path 60, the multiple tooth section outlets 65, and the second header flow path 63 provided in the second end expansion core section 15, before flowing out to the outside through the refrigerant outlet 62. The refrigerant may be a liquid (e.g., oil) or a gas.
[0036] Specifically, the refrigerant flowing in from the refrigerant inlet 61 enters the first header flow path 63, flows circumferentially through it, enters the multiple tooth inlets 64 provided in each of the multiple tooth sections 13, and flows toward the inner diameter. Furthermore, the refrigerant flows axially through the tooth flow paths 60 provided in each of the multiple tooth sections 13. The refrigerant flowing in this manner cools the stator core 10A body, the armature coil 12, and the magnetic shielding cover 50. The refrigerant that has passed through the multiple tooth flow paths 60 flows toward the outer diameter, enters the second header flow path 63 from the multiple tooth outlets 65, merges, and is discharged from the refrigerant outlet 62.
[0037] In this embodiment, by expanding both ends of the stator core 10A toward the outer diameter, the flow area from the refrigerant inlet 61, where the refrigerant flow rate is highest, to the first header flow path 63 can be enlarged, making it possible to increase the refrigerant flow rate and perform efficient cooling. Furthermore, in this embodiment, since the magnetic shielding cover (magnetic shield) 50 is sandwiched between the first and second end-expanded core portions 15, it is possible to enhance the cooling of the magnetic shield as well.
[0038] In this embodiment, an example is shown in which six tooth sections 13 (six tooth section flow paths 60, six tooth section inlets 64, and six tooth section outlets 65) are in communication. However, the embodiment is not limited to this example, and configurations employing a different number of tooth sections 13 are also possible.
[0039] (Other features) As can be seen in Figure 3, the multiple toothed inlets 64 (and multiple toothed outlets 65) are formed such that the shape of part or all of the flow path widens towards the outer diameter. Therefore, pressure loss in that part can be reduced. This structure may be applied to both the multiple toothed inlets 64 and the multiple toothed outlets 65, or to either one of them.
[0040] Furthermore, as can be seen from Figures 2 to 4, two refrigerant reservoirs 66 are provided in a part of the tooth section inlet 64, tooth section outlet 65, and tooth section flow path 60. Figure 5 is an axial cross-sectional view showing another example of a cross-sectional shape when a part of the stator of the rotating electric machine shown in Figure 1 is viewed in the circumferential direction, and the cross-sectional shape of the part including the two refrigerant reservoirs 66 is shown. Figure 6 is a diagram showing a modified example of the shape of the refrigerant reservoir 66 shown in Figure 5.
[0041] The refrigerant reservoir 66 has a wider circumferential flow path than the flow paths of other parts. By widening the flow path, the refrigerant can flow more easily along the refrigerant reservoir 66, thereby achieving uniformity of axial refrigerant flow rate and refrigerant temperature. This structure may be applied to all of the tooth section inlet 64, tooth section outlet 65, and tooth section flow path 60, or to any one of them.
[0042] Furthermore, by arranging part or all of the refrigerant reservoir 66 to extend diagonally with respect to the axial direction, as shown in Figures 5 and 6, it becomes possible to efficiently supply refrigerant to areas where the armature coil temperature is high, such as the inner diameter side, and to efficiently cool them.
[0043] (Various variations) Figure 7 shows a first modified example of the refrigerant inlet 61. Note that the modified example of the refrigerant outlet 62 is the same as that shown in Figure 7, and therefore its illustration is omitted here.
[0044] In this modified example, as can be seen in Figure 7, the refrigerant inlet 61 (and refrigerant outlet 62) is formed such that part 61a or all of the flow path is wider towards the inner diameter. Therefore, the pressure loss in that part can be reduced. This structure may be applied to both the refrigerant inlet 61 and the refrigerant outlet 62, or to either one of them.
[0045] Figure 8 shows a second modified example of the refrigerant inlet 61. Note that the modified example of the refrigerant outlet 62 is the same as that shown in Figure 8, and therefore is omitted from this diagram.
[0046] The refrigerant inlet 61 (and refrigerant outlet 62) is where the refrigerant that cools the stator core 10A passes through in a concentrated manner, resulting in a high flow velocity and the possibility of a large flow velocity distribution within the flow path. To resolve this, a mechanism for leveling the flow velocity distribution (flow velocity distribution leveling mechanism) 61b, such as a wire mesh, is provided at the refrigerant inlet 61, the refrigerant outlet 62, or both. This reduces the pressure loss in that section. This structure may be applied to both the refrigerant inlet 61 and the refrigerant outlet 62, or to either one of them.
[0047] Figure 9 shows a modified example of the first header channel 63. Note that the modified example of the second header channel 63 is the same as that shown in Figure 9, and therefore its illustration is omitted here.
[0048] In the cross-sectional view shown in Figure 3, the first header flow path 63 (and the second header flow path 63) provided in the end-expanded core portion 15 has a structure in which the radial flow path width is constant, but the shape of part or all of the header flow path 63 is formed such that the flow path width widens as it approaches the refrigerant inlet 61 or refrigerant outlet 62. Therefore, the pressure loss in that portion can be reduced. This structure may be applied to both the first header flow path 63 and the second header flow path 63, or to either one of them.
[0049] (Verification results) Referring to Figures 10 and 11, the results of verifying the effects of this embodiment will be described.
[0050] Here, the axial cross-sectional view of the stator 10 of the rotating electric machine described above was used to verify the "flow velocity distribution" and "temperature distribution" of the refrigerant. In this case, a configuration was adopted in which the two refrigerant reservoirs 66 extend horizontally rather than diagonally.
[0051] Figure 10 is a graph showing the "flow velocity distribution" of the refrigerant superimposed on an axial cross-sectional view of a portion of the stator 10 described above. Figure 11 is a graph showing the "temperature distribution" of the refrigerant superimposed on an axial cross-sectional view of a portion of the stator 10 described above. In each figure, the tooth section inlet 64 described above is located in the upper left of the figure, the tooth section flow path 60 described above is located in the center, and the tooth section outlet 65 described above is located in the upper right. In addition, the two refrigerant reservoirs 66 described above are located extending in the axial direction.
[0052] Figure 10 shows the refrigerant flow velocity using a grayscale. Areas with higher refrigerant flow velocity are represented by white, while areas with lower flow velocity are represented by black. The arrows in the figure indicate the direction of refrigerant flow.
[0053] The graph in Figure 10 shows that the flow velocity is particularly high where the refrigerant flows along the two refrigerant reservoirs 66. The flow velocity is also high around the tooth inlet 64 and the tooth outlet 65.
[0054] Figure 11 shows the temperature of the refrigerant represented by shades of black and white (grayscale). Here, areas with higher temperatures are represented by white, and areas with lower temperatures are represented by black.
[0055] The graph in Figure 11 shows that the temperature is particularly low where the refrigerant flows along the two refrigerant reservoirs 66 (i.e., where the refrigerant flow velocity is high). It also shows that low-temperature refrigerant is supplied to the downstream side along the refrigerant reservoirs 66. The refrigerant temperature increases downstream due to the cooling of the stator core 10A, but the effect of supplying low-temperature refrigerant downstream is confirmed by the low-temperature refrigerant that flows along the refrigerant reservoirs 66 and spreads downstream.
[0056] It is presumed that this excellent cooling effect is greatly influenced by the presence of the tooth section inlet 64, tooth section flow path 60, and tooth section outlet 65, as well as the presence of the first and second header flow paths 63 and refrigerant reservoir 66, which are in communication with the tooth section inlet 64 and tooth section outlet 65, respectively.
[0057] (summary) As described in detail above, according to the embodiment, it is possible to provide a stator core for a rotating electric machine and a rotating electric machine that can improve the cooling performance of the stator core, armature coil, and magnetic shielding cover with a simple configuration.
[0058] For example, according to the embodiment, by expanding both ends of the stator core 10A toward the outer diameter, the flow area from the refrigerant inlet 61, where the refrigerant flow rate is highest, to the first header flow path 63 can be enlarged, making it possible to increase the refrigerant flow rate and perform efficient cooling. Furthermore, according to the embodiment, since the magnetic shielding cover (magnetic shield) 50 is sandwiched between the first and second end-expanded core portions 15, it is possible to enhance the cooling of the magnetic shield as well.
[0059] Furthermore, according to the embodiment, while maintaining the manufacturing dimensional accuracy of the stator core or rotating electric machine, eddy current losses generated in the stator core can be reduced, and in addition to cooling the armature coil, the rotor installed on the inner diameter side of the stator core or the structure installed on the outer diameter side can be efficiently cooled.
[0060] Furthermore, according to the embodiment, it is possible to reduce the number of parts as much as possible while ensuring the characteristics required for a rotating electric machine, thereby achieving miniaturization and weight reduction.
[0061] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]
[0062] 1...Rotating electric machine, 10...Stator, 10A...Stator core, 11...Slot, 12...Armature coil, 13...Teeth section, 14...Core back section, 15...End expansion core section, 16...Wedge, 17...Insulator, 20...Rotor, 30...Rotating shaft, 50...Magnetic shielding cover, 60...Teeth section flow path, 61...Refrigerant inlet, 62...Refrigerant outlet, 63...Header flow path, 64...Teeth section inlet, 65...Teeth section outlet, 66...Refrigerant reservoir.
Claims
1. A stator core for a rotating electric machine, comprising an annular core back portion and a plurality of teeth portions extending toward the inner diameter side of the core back portion, and further having a magnetic shielding cover provided on the outer circumference side of the core back portion, The stator core has a structure in which each of the axial ends is extended outwards, and the first and second end-extended core portions are provided. The first and second end expansion core portions are respectively provided with a refrigerant inlet and a refrigerant outlet, The first and second end extension core portions are provided with first and second header flow paths, which are formed so that the refrigerant flows in the circumferential direction, A tooth section flow path is formed so that the refrigerant flows in the axial direction inside each of the plurality of tooth sections, Multiple tooth section inlets that connect the first header flow path and the tooth section flow path, Multiple tooth outlets that connect the tooth section flow path and the second header flow path, It is equipped with, A stator core of a rotating electric machine is configured such that a refrigerant supplied from an external source flows in through the refrigerant inlet, sequentially through the first header flow path, the multiple tooth section inlets, the tooth section flow paths, the multiple tooth section outlets, and the second header flow path, and flows out to the outside through the refrigerant outlet.
2. In the stator core of the rotating electric machine according to claim 1, A stator core for a rotating electric machine, wherein at least one of the multiple toothed inlets and multiple toothed outlets is formed such that part or all of its shape is such that the flow path width widens towards the outer diameter.
3. In the stator core of the rotating electric machine according to claim 1, A stator core for a rotating electric machine, wherein at least one of the refrigerant inlet and the refrigerant outlet is formed such that part or all of its shape is such that the flow path width widens towards the inner diameter side.
4. In the stator core of the rotating electric machine according to claim 1, A stator core of a rotating electric machine, wherein at least one of the refrigerant inlet and the refrigerant outlet is equipped with a mechanism for leveling the flow velocity distribution.
5. In the stator core of the rotating electric machine according to claim 1, A stator core for a rotating electric machine, wherein at least one of the first and second header flow paths is formed such that part or all of its shape increases as it approaches the refrigerant inlet or outlet.
6. In the stator core of the rotating electric machine according to claim 1, A stator core for a rotating electric machine, wherein at least one of the first and second header flow paths and the tooth section flow path is provided with a refrigerant reservoir in a part thereof, the circumferential flow path width being expanded.
7. In the stator core of the rotating electric machine according to claim 6, A stator core of a rotating electric machine, wherein at least a portion of the refrigerant reservoir is configured to extend obliquely with respect to the axial direction.
8. In the stator core of the rotating electric machine according to claim 1, The first and second end extension core portions are arranged to sandwich the magnetic shielding cover from both axial ends, forming a stator core for a rotating electric machine.
9. A rotating electric machine comprising a stator having an armature coil provided on a stator core according to any one of claims 1 to 8, and a rotor disposed at a certain distance from the stator.