Rotating electric machine

Abstract

To provide a rotary electric machine capable of improving a cooling performance by a coolant medium.SOLUTION: Each of core blocks 200A and 200B are alternately arranged to a stator peripheral direction at a predetermined angle pitch θ, and comprises a plurality of coolant passages 202 203 that is extended to a stator radial direction. In each coolant passage 202, a coolant is supplied from an external part, and is extended to a first region E1 on a radial inner peripheral side from a core outer periphery, and each coolant passage 203 is extended to a second region E2 on a radial inner peripheral side from the first region E1. In the core blocks 200A and 200B, the inner peripheral end region of each coolant passage 202 of the core block 200A are communicated with an outer peripheral end region of each coolant passage 203 of the core block 200B, and is laminated so that the inner peripheral end region of each coolant passage 202 of the core block 200B is communicated to the outer peripheral end region of each coolant passage 203 of the core block 200A.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine. Background Art

[0002] Conventionally, as a cooling method for a rotating electrical machine, a method of dropping a refrigerant from above a stator core is known (see Patent Document 1). In Patent Document 1, a plurality of refrigerant guide vanes extending in the axial direction are provided on the outer circumferential surface of the stator core. The refrigerant dropped onto the outer circumferential surface of the stator core and flowing down the outer circumferential surface is sequentially guided in the stator axial direction by the plurality of refrigerant guide vanes, and is finally guided to the coil end portion. Prior Art Literature Patent Literature

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2015-115994 Summary of the Invention Problem to be Solved by the Invention

[0004] However, with the technology described in Patent Document 1, since the configuration is such that cooling is performed by dropping the refrigerant onto the outer circumferential surface of the stator, it is difficult to sufficiently ensure coil cooling performance. Means for Solving the Problem

[0005] A rotating electric machine according to one aspect of the present invention is a rotating electric machine comprising a rotor and a stator having a plurality of slots, wherein the stator core of the stator has first and second core blocks stacked in the axial direction, each of the first and second core blocks has a plurality of first and second flow channels arranged alternately in the circumferential direction of the stator, and at least one of the first and second core blocks has an introduction passage that communicates with any one of the plurality of first flow channels and supplies a coolant from the outside, and the first flow channel has a predetermined radial region The data extends in the circumferential direction, the second channel extends from the predetermined radial region to the region near the slot on the radially inner circumferential side, and the first and second core blocks are stacked axially such that the circumferential end region of the first channel of the first core block and the circumferential end region of the first channel of the second core block are in communication, the first channel of the first core block is in communication with the outer peripheral end region of the second channel of the second core block, and the first channel of the second core block is in communication with the outer peripheral end region of the second channel of the first core block. Each of the first and second core blocks further comprises a plurality of third channels provided in the region near the slot and penetrating in the direction of the core axis, wherein the third channels of the first core block communicate with the inner circumferential end region of the second channel of the second core block, and the third channels of the second core block communicate with the inner circumferential end region of the second channel of the first core block. It is characterized by the following. Furthermore, in another embodiment of the rotating electric machine, the second flow path is characterized in that it penetrates from the region near the slot to the slot. Furthermore, in another embodiment, a rotating electric machine is characterized in that, when the integer N is an integer of 2 or more, the plurality of slots are arranged at a first angular pitch in the circumferential direction of the stator, the plurality of first and second flow paths are arranged alternately at a predetermined angular pitch in the circumferential direction of the stator, the predetermined angular pitch is set to a value of N times the first angular pitch, and the second flow paths arranged between the first flow paths consist of N radially extending flow paths arranged at the first angular pitch in the circumferential direction of the stator. Furthermore, in another embodiment, the stator core is provided with a plurality of fastening portions that protrude from the outer circumference of the core and have bolt insertion holes formed therein, and at least one of the plurality of fastening portions has an introduction hole formed near the bolt insertion hole through which a coolant is introduced from the outside and communicates with the first flow path. Furthermore, in another embodiment, the rotating electric machine is characterized in that the second flow path is in communication with the slot. [Effects of the Invention]

[0006] According to the present invention, it is possible to improve the cooling performance using a refrigerant. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram shows the main components of a rotating electric machine. [Figure 2] This figure shows multiple core blocks stacked in the axial direction. [Figure 3] This is a front view of the core block stack. [Figure 4] This figure shows one of the pair of core blocks shown in Figure 3. [Figure 5] This figure shows the other of the pair of core blocks shown in Figure 3. [Figure 6] It is a front view of a core block arranged at both ends of a stator core. [Figure 7] It is a view showing the D1-D1 cross-section of FIG. 3. [Figure 8] It is a front view of the core block laminate in Modification 1. [Figure 9] It is a view showing the core block of Modification 1. [Figure 10] It is a view showing the D2-D2 cross-section of FIG. 8. [Figure 11] It is a view showing an example of magnetic flux density distribution when no coolant flow path is provided in the stator core. [Figure 12] It is a view showing the magnetic flux density distribution in a comparative example. [Figure 13] It is a view showing one core block in a comparative example. [Figure 14] It is a view showing the other core block in a comparative example. [Figure 15] It is a view showing the magnetic flux density distribution when the core blocks shown in FIGS. 8 and 9 are used. [Figure 16] It is a view showing the torque improvement rate based on the comparative example. [Figure 17] It is a view showing the core block laminate in the second embodiment. [Figure 18] It is a view showing one core block of the core block laminate shown in FIG. 17. [Figure 19] It is a view showing the other core block of the core block laminate shown in FIG. 17. [Figure 20] It is a view showing the D3-D3 cross-section of FIG. 17. [Figure 21] It is a view showing the core block laminate in Modification 2. [Figure 22] It is a view showing one core block of the core block laminate shown in FIG. 21. [Figure 23] It is a view showing the other core block of the core block laminate shown in FIG. 21. [Figure 24] It is a view showing another example of the core block in Modification 2. [Figure 25] It is a diagram showing the torque improvement rate in the second embodiment. [Figure 26] It is a diagram showing another example of the core block shown in Fig. 22. [Figure 27] It is a diagram showing the magnetic flux density distribution when the core blocks shown in Figs. 22 and 23 are used. [Figure 28] It is a diagram showing the magnetic flux density distribution when the core block shown in Fig. 26 is used. [Figure 29] It is a diagram showing the stator core 20 in the third embodiment. [Figure 30] It is a diagram showing the core block laminated body in the third embodiment. [Figure 31] It is a diagram showing one core block of the core block laminated body shown in Fig. 30. [Figure 32] It is a diagram showing the other core block of the core block laminated body shown in Fig. 30. [Figure 33] It is a diagram showing the core blocks arranged at both ends of the stator core in the third embodiment. [Figure 34] It is a diagram showing the D4-D4 cross-section of Fig. 30. Mode for Carrying Out the Invention

[0008] Hereinafter, modes for carrying out the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and are appropriately omitted and simplified for clarification of description. In addition, in the following description, the same or similar elements and processes are denoted by the same reference numerals, and overlapping descriptions may be omitted. It should be noted that the content described below is merely an example of the embodiment of the present invention, the present invention is not limited to the following embodiment, and can be implemented in various other forms.

[0009] First Embodiment Figure 1 shows the stator 2 and rotor 3 of the rotating electric machine 1 as viewed from the positive z-axis direction along the axial direction of the rotor 3. The rotating electric machine 1 comprises a case 4, an annular stator 2 disposed within the case 4, and a rotor 3 disposed on the inner circumference side of the stator 2. The stator 2 comprises a stator core 20 stacked in the axial direction and stator coils 21 housed in slots 201 of the stator core 20. The case 4 is provided with a refrigerant introduction section 42 for introducing refrigerant into the case. A through hole 420 is formed in the refrigerant introduction section 42. Note that the coil conductor used in the stator coil 21 is not limited to square wire, and round wire may also be used.

[0010] As shown in Figure 2, the stator core 20 is formed by stacking four core blocks 200A, 200B, and 210 in the axial direction. The core blocks are arranged in the order of core block 210, core block 200A, core block 200B, and core block 210, starting from the z-axis positive direction. The core blocks 200A, 200B, and 210 are formed by stacking electrical steel sheets. An annular refrigerant flow path 421 is formed between the inner circumferential surface of the case 4 and the outer circumferential surfaces of the core blocks 200A and 200B. The through hole 420 of the refrigerant introduction section 42 communicates with the refrigerant flow path 421.

[0011] Figure 3 is a front view of the laminated core blocks 200A and 200B. In Figure 3, core block 200A is positioned towards the viewer, and core block 200B is positioned behind it (towards the negative z-axis). Core blocks 200A and 200B are composed of core blocks of the same shape. That is, core blocks 200A and 200B are formed by laminating electrical steel sheets of the same shape. As will be described later, core block 200B is obtained by rotating (transforming) core block 200A clockwise by an angle θ (see Figure 5) around the stator axis C.

[0012] Three types of refrigerant flow paths 202, 203, and 204 are formed in core blocks 200A and 200B. Refrigerant flow paths 202-204, shown by solid lines, are formed in core block 200A, while refrigerant flow paths 202-204, shown by dashed lines, are formed in core block 200B.

[0013] Figure 4 shows a front view of the core block 200A in Figure 3. As described above, the core block 200A has multiple refrigerant flow paths 202, 203, and 204 of three types formed therein. The refrigerant flow path 202 extends radially and has an opening on the outer circumference of the core. The inner circumferential end region of the refrigerant flow path 202 extends to the annular first region E1. The radially extending refrigerant flow path 203 extends from the first region E1 to the annular second region E2, which is set near the inner circumferential slot 201. The refrigerant flow paths 202 and 203, which extend in the stator radial direction, penetrate the core block 200A in the stator axial direction. In addition, the refrigerant flow path 204, located in the second region E2, extends in the stator axial direction so as to penetrate the core block 200A.

[0014] In the example shown in Figure 4, the refrigerant flow paths 202 and 203 are alternately arranged in the circumferential direction at a pitch θ equal to the slot pitch (angle θ). In addition, the multiple refrigerant flow paths 204, which are arranged in the circumferential direction at a pitch of 2θ, are set to the same circumferential position as the refrigerant flow path 202.

[0015] Figure 5 shows a front view of core block 200B in Figure 3. Its shape is exactly the same as core block 200A shown in Figure 4. However, the arrangement in the circumferential direction of the stator is different from that of core block 200A. In core block 200B shown in Figure 5, the circumferential position of the refrigerant flow path labeled 202-1 among the multiple refrigerant flow paths 202 is shifted by an angle θ in the clockwise direction compared to core block 200A shown in Figure 4. When stacking core blocks 200A and 200B, they are stacked so that the 0° position in Figure 4 and the 0° position in Figure 5 coincide.

[0016] As shown in Figure 3, when core block 200A and core block 200B are stacked, the inner circumferential end region of the refrigerant flow path 202 of core block 200A faces the outer circumferential end region of the refrigerant flow path 203 of core block 200B. As a result, the refrigerant flow path 202 of core block 200A and the refrigerant flow path 203 of core block 200B are in communication. Similarly, the inner circumferential end region of the refrigerant flow path 202 of core block 200B faces the outer circumferential end region of the refrigerant flow path 203 of core block 200A, and their refrigerant flow paths 202 and 203 are in communication.

[0017] Furthermore, the inner circumferential end region of the refrigerant flow path 203 of core block 200A faces the refrigerant flow path 204 of core block 200B. Similarly, the inner circumferential end region of the refrigerant flow path 203 of core block 200B faces the refrigerant flow path 204 of core block 200A. As a result, the refrigerant flow paths 203 and 204 of the stacked core blocks 200A and 200B are in communication.

[0018] Figure 6 is a front view of the core block 210 shown in Figure 2. As shown in Figures 1 and 2, the core block 210, whose outer diameter is set to be larger than that of core blocks 200A and 200B, is fixed to the inner circumference of case 4. The core block 210 has refrigerant flow paths 204 formed in the same position as the refrigerant flow paths 204 of core blocks 200A and 200B. That is, in the core block 210, the refrigerant flow paths 204 are arranged at a pitch θ.

[0019] Figure 7 shows the D1-D1 cross-section of Figure 3. Note that the core block 210 and the stator coil 21 in slot 201 are not shown in Figure 3, but the core block 210 and the stator coil 21 are shown in Figure 8. The outer peripheral end region of the refrigerant flow path 203 of core block 200A is opposed to the inner peripheral short region of the refrigerant flow path 202 of core block 200B. The inner peripheral end region of the refrigerant flow path 203 of core block 200A is opposed to the refrigerant flow paths 204 of core block 200B and the core block 210 on the left side of the figure. In addition, the refrigerant flow path 204 of core block 200B is opposed to the refrigerant flow path 204 of core block 210 on the right side of the figure.

[0020] The arrows in Figure 7 indicate the flow of the refrigerant. The refrigerant supplied from the outside is introduced through the through-hole 420 of the case 4 shown in Figure 1 into the annular refrigerant flow path 421 between the case 4 and the core blocks 200A and 200B. The refrigerant in the refrigerant flow path 421 flows into the refrigerant flow path 202 of the core block 200B, then passes through refrigerant flow paths 203 and 204 and flows out from the end face of the core block 210 towards the coil end. As the refrigerant flows through the core blocks 200A, 200B, and 210 in this way, the stator core 20 is cooled, and furthermore, the stator coils 21 in the slots 201 are cooled by the stator core 20.

[0021] (Variation 1) Figures 8-10 show a modified example 1 of the core blocks 200A and 200B described above. Figure 8 is a front view of the stack of core blocks 200C and 200D. Core block 200C is located on the near side of the figure, and core block 200D is located on the rear side (negative z-axis side). Core blocks 200C and 200D are composed of core blocks of the same shape. In Figure 8, the refrigerant channels 202 and 203 shown by solid lines are formed in core block 200C. On the other hand, the refrigerant channels 202 and 203 shown by dashed lines are formed in core block 200D.

[0022] Figure 9 shows a front view of the core block 200C in Figure 8. The core block 200C has multiple refrigerant flow paths 202 and 203 arranged alternately in the circumferential direction at a pitch θ. Furthermore, in the core block 200C, the circumferential positions of the refrigerant flow paths 202 and 203 are set to the same position as the slots 201. The refrigerant flow path 202 is located on the outer circumference of the core, similar to the case of the refrigerant flow path 202 in the core block 200A shown in Figure 4. ra diameter It extends to the first region E1 on the radially inner side. The refrigerant flow path 203 is formed to extend radially from the first region E1 to the radially inner side, similar to the refrigerant flow path 203 of the core block 200A shown in Figure 4. The inner end region of the refrigerant flow path 203 is in communication with the slot 201.

[0023] The core block 200D in the stacked state shown in Figure 8 is obtained by rotating the core block 200C shown in Figure 9 by an angle θ in the circumferential direction. When core blocks 200C and 200D are stacked as shown in Figure 8, the inner circumferential end region of the refrigerant flow path 202 of core block 200C faces the outer circumferential end region of the refrigerant flow path 203 of core block 200D. Similarly, the inner circumferential end region of the refrigerant flow path 202 of core block 200D faces the outer circumferential end region of the refrigerant flow path 203 of core block 200C. As a result, the refrigerant flow paths 202 and 203 of core block 200C communicate with the opposing refrigerant flow paths 203 and 202 of core block 200D, respectively.

[0024] Figure 10 shows the D2-D2 cross-section of Figure 8. Note that the core block 210 and the stator coil 21 in the slot 210 are not shown in Figure 8, but the core block 210 and the stator coil 21 are shown in Figure 10. As described above, the inner short region of the refrigerant flow path 202 of the core block 200D faces the outer peripheral end region of the refrigerant flow path 203 of the core block 200C. In addition, the inner peripheral end region of the refrigerant flow path 203 of the core block 200C is in communication with the slot 201.

[0025] The refrigerant in the annular refrigerant flow path 421 flows into the refrigerant flow path 202 of the core block 200D, then passes through the refrigerant flow path 203 of the core block 200C and flows into the slot 201. The refrigerant moves through the gap in the slot 201 in the slot axis direction (towards both ends in the illustration) and flows out from the coil end direction. Thus, in this modified example 1, the refrigerant not only flows through the core blocks 200A and 200B, but is also introduced into the slot 201, directly cooling the stator coil 21 with the refrigerant. As a result, further improvements in cooling efficiency can be achieved.

[0026] Incidentally, forming a refrigerant flow path in the stator core changes the magnetic flux density distribution, resulting in a decrease in torque compared to when there is no refrigerant flow path. Figure 11 shows an example of the magnetic flux density distribution when no refrigerant flow path is provided. Figure 11 shows a portion of the rotor 3 and stator 2, and the line indicated by the symbol 500 represents the magnetic flux density (hereinafter referred to as magnetic flux lines). The number of magnetic flux lines per unit volume represents the magnitude of the magnetic flux density, and the magnetic flux density is expressed by the degree of concentration of magnetic flux lines and the direction in which the magnetic flux lines flow. In the example shown in Figure 11, it can be seen from the number of magnetic flux lines that the magnetic flux density in region F1 is greater than the magnetic flux density in region F2.

[0027] On the other hand, Figure 12 is a comparative example of the magnetic flux density distribution (distribution of magnetic flux lines) when refrigerant channels are formed, as an example of this embodiment. Figures 13 and 14 show the core blocks 300A and 300B that constitute the stator core 20 in the comparative example shown in Figure 12. Multiple refrigerant channels 202 are formed in core block 300A at a pitch θ. The circumferential position of the refrigerant channels 202 is the same as the position of the slots 201. Multiple refrigerant channels 203 that communicate with the slots 201 are formed in core block 300B at a pitch θ. When core blocks 300A and 300B are stacked, the inner circumferential end region of the refrigerant channels 202 and the outer circumferential end region of the refrigerant channels 203 face each other, and the refrigerant channels 202 and refrigerant channels 203 communicate with each other.

[0028] Figure 12(a) shows the magnetic flux density distribution in core block 300A, and Figure 12(b) shows the magnetic flux density distribution in core block 300B. In core block 300A, the flow of magnetic flux lines is obstructed by the radially extending refrigerant flow path 202, and almost no magnetic flux lines are observed in the region indicated by symbol F3 in the back yoke (the core part on the outer circumference of the slot 201). As a result, the effect of torque reduction is significant.

[0029] Figure 15 shows the magnetic flux density distribution when using core blocks 200C and 200D shown in Figures 8 and 9 in this embodiment. Since core blocks 200C and 200D have the same shape, the magnetic flux density distribution is also the same. As shown in Figure 9, in the case of core blocks 200C and 200D, the refrigerant flow paths 202 provided on the outer circumference side of the back yoke and the refrigerant flow paths 203 provided on the inner circumference side are arranged alternately in the circumferential direction with a pitch θ. Therefore, compared to the comparative example (Figure 12), the magnetic flux lines are distributed throughout the entire back yoke, and the torque reduction is suppressed compared to the comparative example.

[0030] Furthermore, core blocks 200A and 200B also form a magnetic flux density distribution that is almost the same as that of core blocks 200C and 200D, thus suppressing torque reduction. In addition, in core block 210 shown in Figure 6, only the refrigerant flow path 204 provided near the slot 201 is formed, so the torque reduction can be suppressed even more compared to core blocks 200A and 200B.

[0031] As shown in Figure 8, the inner circumferential end region of the refrigerant flow path 202 and the outer circumferential end region of the refrigerant flow path 203 of the core blocks 200C and 200D face each other in the first region E1 (see Figure 9). The radial position of this opposing first region E1 is represented by the amount of displacement Δ relative to the radial center position of the back yoke. If the outer diameter of the core is R1 and the distance from the stator axis to the bottom of the slot 201 is R2, then the radial center position of the back yoke is (R1 + R2) / 2. When the opposing region (first region E1) is at the radial center position of the back yoke, Δ = 0, and when it is located on the outer circumferential side of the radial center position, Δ > 0.

[0032] Figure 16 shows the torque improvement rate relative to the comparative example. Line L1, shown by a dashed line, represents the comparative example, and line L2, shown by a solid line, represents the case where core blocks 200C and 200D shown in Figures 8 and 9 are used. In Figure 16, the torque improvement rate is shown with the case where Δ=0 in the comparative example as the baseline (0%). As shown by line L1, in the comparative example, the torque decrease is smallest when Δ=0 (0%), and as the opposing region, the first region E1, approaches the inner and outer circumference from Δ=0, the torque improvement rate becomes a negative value, indicating a further decrease in torque.

[0033] On the other hand, in the case of core blocks 200C and 200D shown in Figures 8 and 9 (solid line L2), the torque improvement rate is greatest at Δ=0, and decreases as the opposing region approaches the inner and outer circumferences from Δ=0. However, the torque improvement rate is positive regardless of whether the displacement Δ is positive or negative.

[0034] As described above, in the first embodiment, by forming refrigerant passages 202 to 204 in the core blocks 200A, 200B and core blocks 200C, 200D of the stator core 20, it is possible to improve the cooling performance of the stator core 20 and stator coil 21 while suppressing torque reduction due to the influence of the refrigerant passages. Furthermore, as shown in Figures 2, 6, and 7, by providing a core block 210 with only the passage 204 formed in the stator core 20, torque reduction can be further suppressed.

[0035] (Second embodiment) Figures 17-19 show the core blocks 200E and 200F in the second embodiment. Figure 17 is a front view of the stacked core blocks 200E and 200F. Figures 18 and 19 are front views of each core block 200E and 200F. In Figure 17, core block 200E is positioned towards the viewer, and core block 200F is positioned behind it (towards the negative z-axis).

[0036] As shown in Figure 18, the core block 200E includes a refrigerant flow path 203 extending radially, a refrigerant flow path 204 extending axially, and a refrigerant flow path 205 extending circumferentially. Furthermore, one of the multiple refrigerant flow paths 205 (refrigerant flow path 205-1) is provided with a refrigerant introduction passage 206 that extends radially and connects the outer circumference of the core with the refrigerant flow path 205. The 18 slots 201 are provided at a pitch θ, i.e., θ = 20°. Three refrigerant flow paths 205 extending circumferentially are provided in the first region E1. The refrigerant flow paths 205 extend over an angle of 3θ, and the three refrigerant flow paths 205 are arranged circumferentially at a pitch of 3θ.

[0037] In the region between the three refrigerant flow paths 205, three refrigerant flow paths 203 are provided at a pitch θ. The refrigerant flow paths 203 extend from the annular first region E1 to the radially inner annular second region E2 (see Figure 4), similar to the refrigerant flow paths 203 shown in Figure 4. The groups of three refrigerant flow paths 203, arranged at a pitch θ, are provided at a pitch of 4θ in the circumferential direction, and three refrigerant flow paths 204 are arranged at a pitch θ between these groups. The multiple refrigerant flow paths 204 are arranged in the annular second region E2, similar to the refrigerant flow paths 204 shown in Figure 4.

[0038] In the case of core block 200F shown in Figure 19, the refrigerant flow path 205-1 does not have a refrigerant introduction passage 206. Also, core block 200F is positioned with the core block rotated clockwise by an angle of 3θ relative to core block 200E. The other configurations are the same as those of core block 200E.

[0039] The core blocks 200E and 200F in Figures 18 and 19 are stacked as shown in Figure 17. The circumferential ends of the refrigerant flow path 205 of core block 200E are positioned to overlap with one end of an adjacent circumferential refrigerant flow path 205 provided in core block 200F. As a result, the refrigerant flow path 205 of core block 200E communicates with the refrigerant flow path 205 of core block 200F, forming an annular flow path.

[0040] Furthermore, the refrigerant flow path 205 of core block 200E faces the outer peripheral end region of the refrigerant flow path 203 of core block 200F, and the inner peripheral end region of the refrigerant flow path 203 of core block 200F faces the refrigerant flow path 204 of core block 200E. Similarly, the refrigerant flow path 205 of core block 200F faces the outer peripheral end region of the refrigerant flow path 203 of core block 200E, and the inner peripheral end region of the refrigerant flow path 203 of core block 200E faces the refrigerant flow path 204 of core block 200F.

[0041] Figure 20 is a cross-sectional view taken along line D3-D3 in Figure 17. Note that the core block 210 and the stator coil 21 in slot 201 are not shown in Figure 17, but 20 The core block 210 and stator coil 21 are also shown. The refrigerant flow path 205 of core block 200E faces the outer peripheral end region of the refrigerant flow path 203 of core block 200F. The refrigerant flow paths 204 of core block 200E and the core block 210 on the right side of the figure face the inner peripheral end region of the refrigerant flow path 203 of core block 200F. In addition, the refrigerant flow path 204 of core block 200E faces the refrigerant flow path 204 of the core block 210 on the left side of the figure.

[0042] The arrows in Figure 20 indicate the flow of refrigerant. Refrigerant is supplied to the refrigerant flow path 205 of the core block 200E from the refrigerant introduction passage 206 shown in Figure 17. The refrigerant introduction passage 206 is connected to an annular refrigerant flow path 421 formed on the inner circumference of case 4 (see Figure 1). Refrigerant in the refrigerant flow path 421 flows into the refrigerant flow path 205 from the refrigerant introduction passage 206 of the core block 200E. The refrigerant that flows into the refrigerant flow path 205 passes through refrigerant flow paths 203 and 204 and flows out from the end face of the core block 210 towards the coil end.

[0043] (Modification 2) Figures 21-23 show modified versions (modification 2) of the core blocks 200E and 200F described above. In modification 2, the stator core 20 is composed of core blocks 200G, 200H and two core blocks 210. Figure 21 is a front view of the stack of core blocks 200G and 200H. Core block 200G is positioned towards the viewer, and core block 200H is positioned behind it (negative z-axis side). Figure 22 is a front view of core block 200G. Figure 23 is a front view of core block 200H.

[0044] As shown in Figure 22, the core block 200G includes a refrigerant flow path 203 that extends radially and communicates with the slot 201, a refrigerant flow path 205 that extends circumferentially, and a refrigerant introduction passage 206 that extends radially and connects the outer circumference of the core with the refrigerant flow path 205. Compared with the core block 200E shown in Figure 18, the circumferential positions of the refrigerant flow paths 203 and 205 of the core block 200G are shifted clockwise by an angle θ / 2, and the circumferential position of the refrigerant flow path 203 coincides with the circumferential position of the slot 201.

[0045] Figure 23 is a front view of core block 200H. Core block 200H is obtained by removing the refrigerant introduction passage 206 from core block 200G and rotating the entire core block clockwise by an angle of 3θ with respect to the stator axis. By stacking core block 200G shown in Figure 22 on top of core block 200H, the core block stack shown in Figure 21 is obtained.

[0046] As shown in Figure 21, the circumferential ends of the refrigerant flow path 205 of core block 200G are arranged to overlap with one end of the circumferentially adjacent refrigerant flow path 205 provided in core block 200H. As a result, the refrigerant flow path 205 of core block 200G communicates with the refrigerant flow path 205 of core block 200H, forming an annular flow path. Furthermore, the refrigerant flow path 205 of core block 200G faces the outer peripheral end region of the refrigerant flow path 203 of core block 200H. Similarly, the refrigerant flow path 205 of core block 200H, shown by the dashed line, faces the outer peripheral end region of the refrigerant flow path 203 of core block 200G.

[0047] Incidentally, in the core blocks 200E and 200F shown in Figure 17, three refrigerant flow paths 203 and 205, and three refrigerant flow paths 204 are arranged alternately at a pitch of 3θ. Therefore, by simply stacking core block 200F with a shift of 3θ relative to core block 200E, all refrigerant flow paths 204 can be connected to refrigerant flow paths 205 via refrigerant flow paths 203.

[0048] On the other hand, if the refrigerant flow path 205 and five refrigerant flow paths 204 and one refrigerant flow path 203 are arranged alternately, as in the core block 200J shown in Figure 24, five cross-sections are required to connect all refrigerant flow paths 204 to the refrigerant flow path 205 via the refrigerant flow path 203. In other words, it is necessary to prepare six of the core blocks 200J shown in Figure 24 and stack the core blocks 200J while shifting them by an angle θ each time. For this reason, in the case of a configuration that provides a circumferentially extending refrigerant flow path 205, it is preferable to arrange the circumferential flow paths (refrigerant flow paths 205) and radial flow paths (refrigerant flow paths 203) alternately at equal pitches, as in Figures 17 and 21.

[0049] In the core block of the first embodiment, for example, as shown in Figures 8 and 9, a refrigerant flow path 202 extending radially is provided on the outer circumference of the back yoke to guide refrigerant from the outside to a refrigerant flow path 203 provided in the inner region of the back yoke via the refrigerant flow path 202. On the other hand, in the second embodiment, a refrigerant flow path 205 extending circumferentially is provided on the outer circumference of the back yoke to guide refrigerant to the refrigerant flow path 203 in the inner region, thereby suppressing torque reduction caused by the refrigerant flow path.

[0050] Figure 25 shows the torque improvement rate, similar to that in Figure 16, and is shown with the case where Δ=0 in the comparative example (without a refrigerant flow path) as the baseline (0%). In Figure 25, the solid line L3 shows the torque improvement rate when using core blocks 200G and 200H. The dashed line L4 shows the torque improvement rate when the refrigerant flow paths 203 and 205 are arranged alternately at a pitch θ, as in the core block 200K shown in Figure 26.

[0051] Figure 27 shows the magnetic flux density distribution when using core blocks 200G and 200H shown in Figures 21-23. Figure 28 shows the magnetic flux density distribution when using core block 200K. By arranging the refrigerant flow paths 203 and 205 alternately, the magnetic flux density distribution is improved, and as shown in Figure 25, the torque is improved compared to the comparative example.

[0052] In a configuration where radially extending refrigerant flow paths 202 and 203 are alternately arranged, as shown in core blocks 200C and 200D in Figures 8 and 9, the torque improvement is maximized when the connection position of the refrigerant flow paths 202 and 203 is at the center of the back yoke's width direction (Δ=0), as shown in Figure 16. On the other hand, in a configuration where circumferentially extending refrigerant flow paths 205 and radially extending refrigerant flow paths 203 are alternately arranged, as in the second embodiment, the torque improvement is greater the closer the connection position of the refrigerant flow paths 203 and 205 is to the inner circumference of the back yoke, as shown in Figure 25. From the trend of change of lines L3 and L4 in Figure 25, it is preferable to set the connection position of the refrigerant flow paths 203 and 205 (first region E1) to the inner circumference of the back yoke.

[0053] (Third embodiment) Figures 29-34 illustrate a third embodiment. In the first and second embodiments described above, the stator 2 was fixed to the inner circumference of the case 4, for example, as shown in Figures 1 and 2. In the third embodiment, as shown in Figure 29, each core block 410A, 400A, 400B, and 410B provided on the stator core 20 is equipped with a fastening portion 409 that protrudes from the outer circumference of the stator core 20 (i.e., the core blocks 410A, 400A, 400B, and 410B). Fastening holes 408 are formed in the fastening portion 409, as will be described later. The stator 2 is then fixed to the stator fixing portion 412 on the case side by inserting bolts 420 through each fastening hole 408 of the core blocks 410A, 400A, 400B, and 410B.

[0054] Figure 30 is a front view of the laminate formed by stacking core blocks 400A and 400B. Figure 31 is a front view of core block 400A. Figure 32 is a front view of core block 400B. Figure 33 is a front view of core block 410A. As shown in Figure 31, core block 400A has refrigerant flow paths 203, 204, 205, and 206 formed in the same way as in core block 200E shown in Figure 18. Core block 400A also has the fastening part described above. 409 Three fasteners are provided at 120° intervals. Each fastening portion 409 has the fastening hole 408 described above. In addition, one of the fastening portions 409 has a refrigerant supply hole 207, and the refrigerant supply hole 207 is supplied with refrigerant. introduction One of the routes 206 is connected.

[0055] As shown in Figure 32, core block 400B is provided with refrigerant channels 203, 204, and 205, similar to those in core block 200F shown in Figure 19. Core blocks 400A and 400B in Figures 31 and 32 are stacked as shown in Figure 30. The circumferential ends of the refrigerant channels 205 of the stacked core block 400A are positioned to face one end of the circumferentially adjacent refrigerant channels 205 provided in core block 400B. As a result, the refrigerant channels 205 of core block 400A communicate with the refrigerant channels 205 of core block 400B, forming an annular channel.

[0056] Furthermore, the refrigerant flow path 205 of core block 400A is connected to the outer peripheral region of the refrigerant flow path 203 of core block 400B, and the inner peripheral region of the refrigerant flow path 203 of core block 400B is connected to the refrigerant flow path 204 of core block 400A. Similarly, the refrigerant flow path 205 of core block 400B is connected to the outer peripheral region of the refrigerant flow path 203 of core block 400A, and the inner peripheral region of the refrigerant flow path 203 of core block 400A is connected to the refrigerant flow path 204 of core block 400B.

[0057] As shown in Figure 33, the core block 410A has a refrigerant flow path 204, similar to that of the core block 210 shown in Figure 6. Furthermore, each fastening portion 409 has a refrigerant supply hole 207 and a fastening hole 408. Although the core block 410B is not shown, it has the same configuration as the core block 410A except that the refrigerant supply hole 207 is omitted.

[0058] Figure 34 is a cross-sectional view taken along line D4-D4 in Figure 30. Note that while Figure 30 does not show the core blocks 410A, 410B and the stator coil 21 in the slot 201, Figure 34 does show the core blocks 410A, 410B and the stator coil 21. The stator fixing portion 412 to which the stator core 20 is fixed has a refrigerant introduction hole 412a formed in a position opposite the refrigerant supply hole 207 of the core block 410A for introducing refrigerant from the outside.

[0059] The refrigerant introduced through the refrigerant inlet hole 412a of the stator fixing part 412 flows from the refrigerant supply hole 207 of the core block 410A to the refrigerant supply hole 207 of the core block 400A. The refrigerant that flows into the refrigerant supply hole 207 of the core block 400A flows through the refrigerant supply hole 207 that is in communication with the refrigerant supply hole 207. introduction The refrigerant flows into the refrigerant flow path 205 via path 206. The refrigerant flow path 205 is opposite the outer peripheral end region of the refrigerant flow path 203 of the core block 400B, and the refrigerant in the refrigerant flow path 205 flows into the refrigerant flow path 203.

[0060] The inner circumferential end region of the refrigerant flow path 203 of core block 400B faces the refrigerant flow paths 204 of core blocks 400A and 410B. Therefore, the refrigerant in the refrigerant flow path 203 flows to the right in the diagram through the refrigerant flow path 204 of core block 410B and is discharged from the core end to the coil end. On the other hand, the refrigerant that flows from the refrigerant flow path 203 of core block 400B into the refrigerant flow path 204 of core block 400A flows to the left in the diagram through the respective refrigerant flow paths 204 of core blocks 400A and 410A and is discharged from the core end to the coil end.

[0061] As described above, the stator core 20 in the third embodiment is configured such that fastening portions 409 provided on the outer circumference of the core block are fixed to the stator fixing portion 412 on the case side. In a rotating electric machine with such a configuration, as in the second embodiment, by arranging circumferentially extending refrigerant flow paths and radially extending refrigerant flow paths alternately at equal pitches in the circumferential direction, it is possible to improve cooling performance by providing refrigerant flow paths while suppressing torque reduction due to the influence of the refrigerant flow paths.

[0062] Furthermore, in a configuration that includes a fastening portion 409, it is possible to introduce refrigerant into the stator core 20 from the end face of the fastening portion 409 using the refrigerant introduction hole 412a of the stator fixing portion 412. In this case, by arranging the refrigerant supply hole 207 near the fastening hole 408, the sealing performance can be improved by bolting it to the case. In addition, the impact of the refrigerant supply hole 207 on torque reduction can be eliminated.

[0063] The effects and benefits of the above-described embodiments and modifications can be summarized as follows.

[0064] (1) As shown in Figures 1 to 6, the rotating electric machine 1 comprises a rotor 3 and a stator 2 having a plurality of slots 201, the stator core 20 of the stator 2 has first and second core blocks 200A and 200B stacked in the axial direction, and each of the core blocks 200A and 200B is provided with a plurality of refrigerant passages (first passages) 202 and refrigerant passages (second passages) 203 that are alternately arranged in the circumferential direction of the stator at a predetermined angular pitch θ and extend in the radial direction of the stator, and the refrigerant passages 202 are supplied with refrigerant from the outside Furthermore, the refrigerant flow path 203 extends from the outer circumference of the core to a first region (predetermined radial region) E1 on the radially inner side, and extends from the first region E1 to a second region (region near the slot) E2 on the radially inner side. Core blocks 200A and 200B are stacked axially such that the inner end region of the refrigerant flow path 202 of core block 200A communicates with the outer end region of the refrigerant flow path 203 of core block 200B, and the inner end region of the refrigerant flow path 202 of core block 200B communicates with the outer end region of the refrigerant flow path 203 of core block 200A.

[0065] As described above, each of the core blocks 200A and 200B has multiple refrigerant flow paths 202 and 203 that extend in the radial direction of the stator, which are alternately arranged in the circumferential direction of the stator at a predetermined angular pitch θ. The multiple refrigerant flow paths 202 extend from the outer circumference of the back yoke to the first region E1, and the multiple refrigerant flow paths 203 extend from the first region E1 to the second region E2, which is the region near the slots. As a result, it is possible to improve the cooling efficiency by the refrigerant while suppressing torque reduction.

[0066] (2) In (1) above, as shown in Figures 3, 4, 16, etc., it is preferable that the inner circumferential end region of the refrigerant flow path 202 and the outer circumferential end region of the refrigerant flow path 203, which communicate with each other, are located approximately midway between the outer circumferential end of the slot 201 and the outer circumference of the stator core 20 (i.e., Δ=0). By setting it in this way, the torque improvement rate can be maximized as shown in Figure 16, that is, the torque reduction due to the influence of the refrigerant flow path can be suppressed to a smaller extent.

[0067] (3) As shown in Figures 1, 17 to 25, the rotating electric machine 1 comprises a rotor 3 and a stator 2 having a plurality of slots 201. The stator core 20 of the stator 2 has first and second core blocks 200E and 200F stacked in the axial direction. Each of the core blocks 200E and 200F communicates with a plurality of refrigerant passages (first passages) 205 and refrigerant passages (second passages) 203 that are alternately arranged in the circumferential direction of the stator at a pitch (predetermined angular pitch) 3θ, and with one of the plurality of refrigerant passages 205, and is supplied with refrigerant from the outside. The system includes a refrigerant introduction passage (introduction passage) 206, the refrigerant flow path 205 extends in the stator circumferential direction in a first region (determined radial region) E1, and the refrigerant flow path 203 extends from the first region E1 to a second region (region near the slot) E2 on the radially inner circumferential side. The core blocks 200E and 200F are stacked axially such that the refrigerant flow path 205 of the core block 200E communicates with the outer peripheral end region of the refrigerant flow path 203 of the core block 200F, and the refrigerant flow path 205 of the core block 200F communicates with the outer peripheral end region of the refrigerant flow path 203 of the core block 200E.

[0068] As described above, by alternately arranging the refrigerant flow path 205, which extends in the circumferential direction of the stator, and the refrigerant flow path 203, which is provided on the inner circumference side of the core and extends in the radial direction, at a predetermined angular pitch in the circumferential direction of the stator, it is possible to improve the cooling efficiency by the refrigerant while suppressing torque reduction.

[0069] (4) In (3) above, as shown in Figures 21 to 25, it is preferable that the first region E1 is located on the inner side of the core, approximately midway between the outer edge of the slot 201 and the outer edge of the stator core 20 (i.e., Δ=0). By setting it in this way, as shown in Figure 25, the torque improvement rate can be made larger, that is, the torque reduction due to the influence of the refrigerant flow path can be kept to a minimum.

[0070] (5) In (1) or (3) above, as shown in Figures 3 to 5, each of the core blocks 200A and 200B is further provided with a plurality of refrigerant passages (third passages) 204 located in the second region E2 and penetrating in the direction of the core axis, the refrigerant passages 204 of core block 200A communicate with the inner circumferential end region of the refrigerant passage 203 of core block 200B, and the refrigerant passages 204 of core block 200B communicate with the inner circumferential end region of the refrigerant passage 203 of core block 200A. The refrigerant flowing through the refrigerant passages 204 near the slot can improve the cooling efficiency of the stator coil 21 in the slot 201.

[0071] (6) In (5) above, as shown in Figures 2, 6, 7, etc., the stator core 20 further has a third core block 210 equipped with a plurality of refrigerant passages (fourth passages) 204 at each of the axial ends of the stacked core blocks 200A and 200B, and the refrigerant passages 204 penetrate the core block 210 in the axial direction and communicate with the refrigerant passages 203 of the adjacent core block 200A or core block 200B. By including the core block 210 in the stator core 20, the torque reduction can be further suppressed.

[0072] (7) In (1) or (3) above, it is preferable that the refrigerant flow path 203 penetrates from the second region E2 in the region near the slot to the slot 201, as shown in Figures 8 and 9. By allowing the refrigerant to flow from the refrigerant flow path 203 into the slot 201, the stator coil 21 can be directly cooled by the refrigerant, thereby improving the cooling efficiency of the stator coil 21.

[0073] (8) In (3) above, as shown in Figures 17 to 19, when the integer N is an integer of 2 or more, the plurality of slots 201 are arranged in the circumferential direction of the stator at an angular pitch θ, the predetermined angular pitch is set to a value of N times the angular pitch θ, and the refrigerant flow path 203 arranged between the refrigerant flow paths 205 is preferably composed of N radially extending flow paths arranged in the circumferential direction of the stator at an angular pitch θ. With this configuration, a refrigerant flow path that communicates with each other can be formed in a single transfer.

[0074] (9) In (3) above, as shown in Figures 29 to 34, the stator core 20 is provided with a plurality of fastening portions 409 that protrude from the outer circumference of the core and have fastening holes (bolt insertion holes) 408 formed therein, and it is preferable that at least one of the plurality of fastening portions 409 has a refrigerant supply hole (inlet hole) 207 formed near the fastening hole 408, through which refrigerant is introduced from the outside and communicates with the refrigerant flow path 205. By arranging the refrigerant supply hole 207 near the fastening hole 408, the influence of the refrigerant supply hole 207 on torque reduction is eliminated and the sealing performance is improved by bolt fastening.

[0075] The various embodiments and modifications described above are merely examples, and the present invention is not limited to these, as long as the features of the invention are not impaired. Other embodiments conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of Symbols]

[0076] 1...Rotating electric machine, 2...Stator, 3...Rotor, 4...Case, 20...Stator core, 21...Stator coil, 200A~200K, 210, 400A, 400B, 410A, 410B...Core block, 201...Slot, 202~205, 421...Refrigerant flow path, 206...Refrigerant introduction path, 207...Refrigerant supply hole, 408...Fastening hole, 409...Fastening part, 412...Stator fixing part, 420...Through hole, E1...First region, E2...Second region

Claims

1. A rotating electric machine comprising a rotor and a stator having multiple slots, The stator core of the stator has first and second core blocks stacked in the axial direction, Each of the first and second core blocks is provided with a plurality of first and second flow paths arranged alternately in the circumferential direction of the stator, and at least one of the first and second core blocks is provided with an introduction path that communicates with any one of the plurality of first flow paths and supplies refrigerant from the outside. The first flow channel extends in the circumferential direction of the stator in a predetermined radial region, The second flow path extends from the predetermined radial region to the region near the slot on the radially inner circumference side, The first and second core blocks are stacked axially such that the circumferential end region of the first channel of the first core block and the circumferential end region of the first channel of the second core block are in communication, the first channel of the first core block is in communication with the outer peripheral end region of the second channel of the second core block, and the first channel of the second core block is in communication with the outer peripheral end region of the second channel of the first core block. Each of the first and second core blocks further comprises a plurality of third channels provided in the region near the slot and penetrating in the direction of the core axis, The third channel of the first core block communicates with the inner circumferential end region of the second channel of the second core block. A rotating electric machine characterized in that the third flow channel of the second core block communicates with the inner circumferential end region of the second flow channel of the first core block.

2. In the rotating electric machine according to Claim 1, The stator core further comprises a third core block having a plurality of fourth channels at each of the axial ends of the stacked first and second core blocks, A rotating electric machine characterized in that the fourth flow path penetrates the third core block in the axial direction and communicates with the third flow path of an adjacent first or second core block.

3. A rotating electric machine comprising a rotor and a stator having a plurality of slots, The stator core of the stator has first and second core blocks stacked in the axial direction, Each of the first and second core blocks is provided with a plurality of first and second flow paths arranged alternately in the circumferential direction of the stator, and at least one of the first and second core blocks is provided with an introduction path that communicates with any one of the plurality of first flow paths and supplies refrigerant from the outside. The first flow channel extends in the circumferential direction of the stator in a predetermined radial region, The second flow path extends from the predetermined radial region to the region near the slot on the radially inner circumference side, The first and second core blocks are stacked axially such that the circumferential end region of the first channel of the first core block and the circumferential end region of the first channel of the second core block are in communication, the first channel of the first core block is in communication with the outer peripheral end region of the second channel of the second core block, and the first channel of the second core block is in communication with the outer peripheral end region of the second channel of the first core block. A rotating electric machine characterized in that the second flow path extends from the region near the slot to the slot.

4. A rotating electric machine comprising a rotor and a stator having a plurality of slots, The stator core of the stator has first and second core blocks stacked in the axial direction, Each of the first and second core blocks is provided with a plurality of first and second flow paths arranged alternately in the circumferential direction of the stator, and at least one of the first and second core blocks is provided with an introduction path that communicates with any one of the plurality of first flow paths and supplies refrigerant from the outside. The first flow channel extends in the circumferential direction of the stator in a predetermined radial region, The second flow path extends from the predetermined radial region to the region near the slot on the radially inner circumference side, The first and second core blocks are stacked axially such that the circumferential end region of the first channel of the first core block and the circumferential end region of the first channel of the second core block are in communication, the first channel of the first core block is in communication with the outer peripheral end region of the second channel of the second core block, and the first channel of the second core block is in communication with the outer peripheral end region of the second channel of the first core block. When N is an integer greater than or equal to 2, The multiple slots are arranged in the circumferential direction of the stator at a first angular pitch, The plurality of first and second flow channels are arranged alternately at a predetermined angular pitch in the circumferential direction of the stator. The predetermined angular pitch is set to a value that is N times the first angular pitch. A rotating electric machine characterized in that the second flow path, which is arranged between the first flow paths, consists of N radially extending flow paths arranged at a first angular pitch in the stator circumferential direction.

5. A rotating electric machine comprising a rotor and a stator having a plurality of slots, The stator core of the stator has first and second core blocks stacked in the axial direction, Each of the first and second core blocks is provided with a plurality of first and second flow paths arranged alternately in the circumferential direction of the stator, and at least one of the first and second core blocks is provided with an introduction path that communicates with any one of the plurality of first flow paths and supplies refrigerant from the outside. The first flow channel extends in the circumferential direction of the stator in a predetermined radial region, The second flow path extends from the predetermined radial region to the region near the slot on the radially inner circumference side, The first and second core blocks are stacked axially such that the circumferential end region of the first channel of the first core block and the circumferential end region of the first channel of the second core block are in communication, the first channel of the first core block is in communication with the outer peripheral end region of the second channel of the second core block, and the first channel of the second core block is in communication with the outer peripheral end region of the second channel of the first core block. The stator core is provided with a plurality of fastening portions that protrude from the outer circumference of the core and have bolt insertion holes formed therein. A rotating electric machine characterized in that at least one of the multiple fastening portions has an introduction hole formed near the bolt insertion hole through which a refrigerant is introduced from the outside and communicates with the first flow path.

6. A rotating electric machine comprising a rotor and a stator having a plurality of slots, The stator core of the stator has first and second core blocks stacked in the axial direction, Each of the first and second core blocks is provided with a plurality of first and second flow paths arranged alternately in the circumferential direction of the stator, and at least one of the first and second core blocks is provided with an introduction path that communicates with any one of the plurality of first flow paths and supplies refrigerant from the outside. The first flow channel extends in the circumferential direction of the stator in a predetermined radial region, The second flow path extends from the predetermined radial region to the region near the slot on the radially inner circumference side, The first and second core blocks are stacked axially such that the circumferential end region of the first channel of the first core block and the circumferential end region of the first channel of the second core block are in communication, the first channel of the first core block is in communication with the outer peripheral end region of the second channel of the second core block, and the first channel of the second core block is in communication with the outer peripheral end region of the second channel of the first core block. A rotating electric machine characterized in that the second flow path is in communication with the slot.

7. In the rotating electric machine according to any one of claims 1 to 6, A rotating electric machine characterized in that the predetermined radial region is located on the inner side of the core, approximately halfway between the outer edge of the slot and the outer circumference of the stator core.

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