Rotating electric machines

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 electric machine. [Background technology]

[0002] A conventional cooling method for a rotating electric machine is to drip a refrigerant from above the stator core (see Patent Document 1). In Patent Document 1, multiple refrigerant guide vanes extending in the axial direction are provided on the outer peripheral surface of the stator core. The refrigerant that drips onto the outer peripheral surface of the stator core and flows down the outer peripheral surface is guided in the axial direction of the stator by the multiple refrigerant guide vanes, and is ultimately guided to the coil end portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-115994 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, the refrigerant is dropped onto the outer peripheral surface of the stator to cool it, making it difficult to ensure sufficient 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 including 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 being alternately arranged at a predetermined angular pitch in the circumferential direction of the stator and including a plurality of first and second flow paths extending in the radial direction of the stator, wherein the first flow paths receive a refrigerant supplied from the outside and extend from the outer periphery of the core to a predetermined radial region on the radially inner side, and the second flow paths extend from the predetermined radial region to a region near the slot on the radially inner side, and the first and second core blocks are stacked in the axial direction such that an inner peripheral end region of the first flow path of the first core block communicates with an outer peripheral end region of the second flow path of the second core block, and the inner peripheral end region of the first flow path of the second core block communicates with an outer peripheral end region of the second flow path of the first core block. Each of the first and second core blocks further includes a plurality of third flow passages provided in the slot vicinity region and penetrating in the core axial direction, the third flow passages of the first core block communicate with inner peripheral end regions of the second flow passages of the second core block, and the third flow passages of the second core block communicate with inner peripheral end regions of the second flow passages of the first core block. It is characterized by the following. [Effects of the Invention]

[0006] According to the present invention, the cooling performance of the refrigerant can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a diagram illustrating a main part of a rotating electric machine. [Figure 2] FIG. 2 is a diagram showing a plurality of core blocks stacked in the axial direction. [Figure 3] FIG. 2 is a front view of a core block laminate. [Figure 4] FIG. 4 is a diagram showing one of the pair of core blocks shown in FIG. 3. [Figure 5] 4 is a diagram showing the other of the pair of core blocks shown in FIG. 3. FIG. [Figure 6] FIG. 2 is a front view of core blocks disposed at both ends of the stator core. [Figure 7] FIG. 4 is a cross-sectional view taken along the line D1-D1 in FIG. 3. [Figure 8] FIG. 10 is a front view of a core block laminate according to a first modified example. [Figure 9]FIG. 10 is a diagram showing a core block of a first modified example. [Figure 10] FIG. 9 is a cross-sectional view taken along line D2-D2 of FIG. 8. [Figure 11] 10 is a diagram showing an example of magnetic flux density distribution when a refrigerant flow path is not provided in the stator core. FIG. [Figure 12] FIG. 10 is a diagram showing a magnetic flux density distribution in a comparative example. [Figure 13] FIG. 10 is a diagram showing one core block in a comparative example. [Figure 14] FIG. 10 is a diagram showing the other core block in the comparative example. [Figure 15] FIG. 10 is a diagram showing a magnetic flux density distribution when the core block shown in FIGS. [Figure 16] FIG. 10 is a diagram showing a torque improvement rate based on a comparative example. [Figure 17] FIG. 10 is a diagram showing a core block laminate according to the second embodiment. [Figure 18] 18 is a diagram showing one core block of the core block laminate shown in FIG. 17. FIG. [Figure 19] 18 is a diagram showing the other core block of the core block stack shown in FIG. 17. FIG. [Figure 20] FIG. 18 is a cross-sectional view taken along line D3-D3 in FIG. 17. [Figure 21] FIG. 10 is a diagram showing a core block laminate according to a second modification. [Figure 22] 22 is a diagram showing one core block of the core block laminate shown in FIG. 21. FIG. [Figure 23] 22 is a diagram showing the other core block of the core block stack shown in FIG. 21. FIG. [Figure 24] FIG. 10 is a diagram showing another example of a core block in Modification 2. [Figure 25] FIG. 10 is a diagram showing a torque improvement rate in the second embodiment. [Figure 26] 23 is a diagram showing another example of the core block shown in FIG. 22. FIG. [Figure 27] FIG. 24 is a diagram showing a magnetic flux density distribution when the core block shown in FIGS. 22 and 23 is used. [Figure 28] FIG. 27 is a diagram showing a magnetic flux density distribution when the core block shown in FIG. 26 is used. [Figure 29] FIG. 10 is a diagram showing a stator core 20 according to a third embodiment. [Figure 30] 10A and 10B are diagrams illustrating a core block laminate according to a third embodiment. [Figure 31] 31 is a diagram showing one core block of the core block laminate shown in FIG. 30. FIG. [Figure 32] 31 is a diagram showing the other core block of the core block stack shown in FIG. 30. FIG. [Figure 33] 10A and 10B are diagrams showing core blocks arranged on both ends of a stator core in a third embodiment. [Figure 34] FIG. 31 is a cross-sectional view taken along line D4-D4 of FIG. 30. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. Furthermore, in the following description, identical or similar elements and processes are designated by the same reference numerals, and redundant explanations may be omitted. Note that the content described below merely shows an example of an embodiment of the present invention, and the present invention is not limited to the following embodiment, and can be implemented in various other forms.

[0009] (First embodiment) FIG. 1 is a view of the stator 2 and rotor 3 of a rotating electric machine 1, viewed from the positive direction of the z coordinate axis along the axial direction of the rotor 3. The rotating electric machine 1 includes a case 4, an annular stator 2 disposed within the case 4, and the rotor 3 disposed on the inner circumferential side of the stator 2. The stator 2 includes a stator core 20 laminated in the axial direction and a stator coil 21 housed in a slot 201 in the stator core 20. The case 4 is provided with a refrigerant introduction section 42 for introducing a refrigerant into the case. A through-hole 420 is formed in the refrigerant introduction section 42. The coil conductor used for the stator coil 21 is not limited to a rectangular wire, and a round wire may also be used.

[0010] As shown in FIG. 2, the stator core 20 is formed by stacking four core blocks 200A, 200B, and 210 in the axial direction. Starting from the positive direction of the z-axis, core block 210, core block 200A, core block 200B, and core block 210 are arranged in this order. Core blocks 200A, 200B, and 210 are formed by stacking electromagnetic steel sheets. An annular refrigerant flow path 421 is formed between the inner peripheral surface of case 4 and the outer peripheral surfaces of core blocks 200A and 200B. Through-hole 420 of refrigerant introduction portion 42 communicates with refrigerant flow path 421.

[0011] FIG. 3 is a front view of a stack of core blocks 200A and 200B. In FIG. 3, core block 200A is arranged on the front side of the drawing, and core block 200B is arranged behind it (on the negative z-axis side). Core block 200A and core block 200B are composed of core blocks of the same shape. That is, core blocks 200A and 200B are formed by laminating electromagnetic steel sheets of the same shape. As will be described later, core block 200B is rotated (transposed) clockwise by an angle θ (see FIG. 5) around stator axis C with respect to core block 200A.

[0012] The core blocks 200A and 200B are formed with three types of refrigerant flow paths 202, 203, and 204. The refrigerant flow paths 202 to 204 shown by solid lines are formed in the core block 200A, and the refrigerant flow paths 202 to 204 shown by dashed lines are formed in the core block 200B.

[0013] FIG. 4 is a front view of the core block 200A in FIG. 3. As described above, the core block 200A is formed with three types of refrigerant flow paths 202, 203, and 204. The refrigerant flow path 202 extends radially and has an opening on the outer periphery of the core. The inner peripheral end region of the refrigerant flow path 202 extends to the annular first region E1. The refrigerant flow path 203 extending radially extends from the first region E1 to the annular second region E2 set near the slot 201 on the inner peripheral side. The refrigerant flow paths 202 and 203 extending in the stator radial direction penetrate the core block 200A in the stator axial direction. The refrigerant flow path 204 arranged in the second region E2 extends in the stator axial direction so as to penetrate the core block 200A.

[0014] 4, the refrigerant flow paths 202 and 203 are alternately arranged in the circumferential direction at a pitch θ that is the same as the slot pitch (angle θ). Furthermore, the multiple refrigerant flow paths 204 arranged in the circumferential direction at a pitch of 2θ are set to have the same circumferential position as the refrigerant flow paths 202.

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

[0016] 3, when core block 200A and core block 200B are stacked, the inner peripheral end region of refrigerant flow path 202 of core block 200A faces the outer peripheral end region of refrigerant flow path 203 of core block 200B. As a result, refrigerant flow path 202 of core block 200A and refrigerant flow path 203 of core block 200B communicate with each other. Similarly, the inner peripheral end region of refrigerant flow path 202 of core block 200B faces the outer peripheral end region of refrigerant flow path 203 of core block 200A, and these refrigerant flow paths 202, 203 communicate with each other.

[0017] Furthermore, the inner peripheral end region of the refrigerant flow path 203 of the core block 200A faces the refrigerant flow path 204 of the core block 200B. Similarly, the inner peripheral end region of the refrigerant flow path 203 of the core block 200B faces the refrigerant flow path 204 of the core block 200A. As a result, the refrigerant flow paths 203 and 204 of the stacked core blocks 200A and 200B communicate with each other.

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

[0019] Fig. 7 is a diagram showing a cross section taken along D1-D1 in Fig. 3. Note that Fig. 3 does not show the core block 210 and the stator coils 21 in the slots 201, but Fig. 8 also shows the core block 210 and the stator coils 21. The outer peripheral end region of the refrigerant flow path 203 of the core block 200A faces the inner peripheral short region of the refrigerant flow path 202 of the core block 200B. The inner peripheral end region of the refrigerant flow path 203 of the core block 200A faces the refrigerant flow path 204 of the core block 200B and the core block 210 on the left side in the figure. In addition, the refrigerant flow path 204 of the core block 200B faces the refrigerant flow path 204 of the core block 210 on the right side in the figure.

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

[0021] (Variation 1) 8 to 10 are diagrams showing a first modified example of the core blocks 200A and 200B described above. FIG. 8 is a front view of a stack of core blocks 200C and 200D. Core block 200C is arranged on the front side of the figure, and core block 200D is arranged behind it (on the negative z-axis side). Core blocks 200C and 200D are composed of core blocks of the same shape. In FIG. 8, refrigerant flow paths 202 and 203 shown by solid lines are formed in core block 200C. On the other hand, refrigerant flow paths 202 and 203 shown by dashed lines are formed in core block 200D.

[0022] FIG. 9 shows a front view of the core block 200C in FIG. 8. In the core block 200C, a plurality of coolant flow paths 202, 203 are alternately arranged at a pitch θ in the circumferential direction. In the core block 200C, the circumferential positions of the coolant flow paths 202, 203 are set to the same positions as the slots 201. The coolant flow paths 202 are arranged from the outer periphery of the core, similar to the coolant flow paths 202 of the core block 200A shown in FIG. Diameter The refrigerant flow paths 203 extend to the first region E1 on the radially inner side, similar to the refrigerant flow paths 203 of the core block 200A shown in Fig. 4. The inner peripheral end regions of the refrigerant flow paths 203 communicate with the slots 201.

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

[0024] Fig. 10 is a diagram showing a cross section taken along D2-D2 in Fig. 8. Note that Fig. 8 does not show the core block 210 and the stator coils 21 in the slots 210, but Fig. 10 also shows the core block 210 and the stator coils 21. As described above, the outer peripheral end region of the refrigerant flow path 203 of the core block 200C faces the inner peripheral short region of the refrigerant flow path 202 of the core block 200D. In addition, the inner peripheral end region of the refrigerant flow path 203 of the core block 200C communicates with the slots 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 slots 201. The refrigerant moves through the gaps in the slots 201 in the slot axial direction (towards both ends in the figure), and flows out from the coil end direction. Thus, in the first modification, the refrigerant not only flows through the core blocks 200A and 200B, but is also introduced into the slots 201, where it directly cools the stator coils 21. As a result, the cooling efficiency can be further improved.

[0026] Incidentally, forming a coolant flow path in the stator core changes the magnetic flux density distribution, resulting in a decrease in torque compared to when no coolant flow path is provided. FIG. 11 is a diagram showing an example of the magnetic flux density distribution when no coolant flow path is provided. FIG. 11 shows a portion of the rotor 3 and stator 2, and the lines indicated by the reference numeral 500 are lines representing 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 concentration of the magnetic flux lines and the direction in which they flow. In the example shown in FIG. 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, Fig. 12 shows a comparative example of magnetic flux density distribution (distribution of magnetic flux lines) when a refrigerant flow path is formed, as a comparative example of this embodiment. Figs. 13 and 14 show core blocks 300A and 300B constituting stator core 20 in the comparative example shown in Fig. 12. Core block 300A has a plurality of refrigerant flow paths 202 formed at a pitch θ. The circumferential positions of refrigerant flow paths 202 are the same as the slots 201. Core block 300B has a plurality of refrigerant flow paths 203 formed at a pitch θ, each refrigerant flow path 203 communicating with slots 201. When core blocks 300A and 300B are stacked, the inner peripheral end region of refrigerant flow path 202 faces the outer peripheral end region of refrigerant flow path 203, and refrigerant flow paths 202 and 203 communicate with each other.

[0028] Fig. 12(a) shows the magnetic flux density distribution in core block 300A, and Fig. 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 refrigerant flow paths 202 extending in the radial direction, and magnetic flux lines are hardly visible in the region indicated by the symbol F3 of the back yoke (the core portion on the outer circumferential side of slots 201). As a result, the torque reduction effect is significant.

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

[0030] In core blocks 200A and 200B, a magnetic flux density distribution similar to that in core blocks 200C and 200D is formed, thereby suppressing torque reduction. Furthermore, in core block 210 shown in Fig. 6, only coolant flow paths 204 are formed near slots 201, so torque reduction can be further suppressed compared to core blocks 200A and 200B.

[0031] As shown in Fig. 8, the inner peripheral end region of the refrigerant flow path 202 and the outer peripheral end region of the refrigerant flow path 203 of the core blocks 200C and 200D face each other in a first region E1 (see Fig. 9). The radial position of this facing first region E1 is represented by a deviation Δ based on the radial center position of the back yoke. If the core outer diameter is R1 and the distance from the stator axis to the bottom of the slot 201 is R2, the radial center position of the back yoke is (R1 + R2) / 2. If the facing region (first region E1) is located at the radial center position of the back yoke, Δ = 0, and if it is located on the outer periphery of the radial center position, Δ > 0.

[0032] Fig. 16 is a diagram showing the torque improvement rate based on the comparative example. The dashed line L1 indicates the comparative example, and the solid line L2 indicates the case where the core blocks 200C and 200D shown in Figs. 8 and 9 are used. Fig. 16 shows the torque improvement rate based on the reference (0%) when Δ=0 in the comparative example. As shown by line L1, in the comparative example, the torque reduction is smallest (0%) when Δ=0, and it can be seen that the torque improvement rate becomes negative as the first region E1, which is the opposing region, moves from Δ=0 toward the inner and outer peripheries, resulting in a greater reduction in torque.

[0033] 8 and 9 (solid line L2), the torque improvement rate is greatest when Δ=0, and decreases as the opposing region approaches the inner and outer peripheries from Δ=0. However, the torque improvement rate is a positive value regardless of whether the deviation Δ is positive or negative.

[0034] As described above, in the first embodiment, by forming the refrigerant flow paths 202-204 in the core blocks 200A, 200B and the core blocks 200C, 200D of the stator core 20, it is possible to suppress torque reduction due to the influence of the refrigerant flow paths while improving the cooling performance of the stator core 20 and the stator coil 21. Furthermore, as shown in FIGS. 2, 6, and 7, by providing the stator core 20 with a core block 210 in which only the flow path 204 is formed, it is possible to further suppress torque reduction.

[0035] (Second embodiment) Figures 17 to 19 are views showing core blocks 200E and 200F in the second embodiment. Figure 17 is a front view of core blocks 200E and 200F in a stacked state. Figures 18 and 19 are front views of each core block 200E and 200F. In Figure 17, core block 200E is arranged on the front side of the illustration, and core block 200F is arranged behind it (on the negative z-axis side).

[0036] As shown in Fig. 18, the core block 200E includes a refrigerant flow path 203 extending in the radial direction, a refrigerant flow path 204 extending in the axial direction, and a refrigerant flow path 205 extending in the circumferential direction. Furthermore, one of the multiple refrigerant flow paths 205 (refrigerant flow path 205-1) is provided with a refrigerant introduction path 206 extending in the radial direction and connecting the outer periphery of the core with the refrigerant flow path 205. The 18 slots 201 are arranged at a pitch θ, i.e., θ = 20°. Three refrigerant flow paths 205 extending in the circumferential direction are provided in the first region E1. The refrigerant flow paths 205 extend over an angle 3θ, and the three refrigerant flow paths 205 are arranged in the circumferential direction at a pitch of 3θ.

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

[0038] 19, the coolant flow path 205-1 does not have a coolant introduction path 206. The core block 200F is rotated clockwise by an angle 3θ with respect to the core block 200E. The other configurations are the same as those of the core block 200E.

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

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

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

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

[0043] (Variation 2) 21 to 23 are diagrams showing a modified example (modification 2) of the core blocks 200E and 200F described above. In modification 2, the stator core 20 is composed of core blocks 200G and 200H and two core blocks 210. FIG. 21 is a front view of a stack of core blocks 200G and 200H. Core block 200G is arranged on the front side of the illustration, and core block 200H is arranged behind it (on the negative z-axis side). FIG. 22 is a front view of core block 200G. FIG. 23 is a front view of core block 200H.

[0044] 22, core block 200G includes refrigerant flow paths 203 extending radially and communicating with slots 201, refrigerant flow paths 205 extending circumferentially, and refrigerant introduction paths 206 extending radially and communicating the outer periphery of the core with refrigerant flow path 205. Compared to core block 200E shown in FIG. 18, the circumferential positions of refrigerant flow paths 203, 205 in core block 200G are shifted clockwise by an angle θ / 2, and the circumferential position of refrigerant flow path 203 coincides with the circumferential position of slot 201.

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

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

[0047] 17, three refrigerant flow paths 203, refrigerant flow paths 205, and three refrigerant flow paths 204 are alternately arranged at a pitch of 3θ. Therefore, by simply stacking core block 200F with an angle of 3θ offset from core block 200E, all refrigerant flow paths 204 can be connected to refrigerant flow path 205 via refrigerant flow paths 203.

[0048] On the other hand, when the refrigerant flow paths 205, five refrigerant flow paths 204, and one refrigerant flow path 203 are arranged alternately as in the core block 200J shown in Fig. 24, five rotations are required to connect all of the refrigerant flow paths 204 to the refrigerant flow path 205 via the refrigerant flow paths 203. That is, six core blocks 200J of Fig. 24 must be prepared and stacked while being shifted by the angle θ each time. Therefore, in a configuration in which refrigerant flow paths 205 extending in the circumferential direction are provided, it is preferable to alternately arrange the circumferential flow paths (refrigerant flow paths 205) and the radial flow paths (refrigerant flow paths 203) at equal pitches, as in Figs. 17 and 21.

[0049] 8 and 9, the core block in the first embodiment is provided with refrigerant flow passages 202 extending in the radial direction on the outer periphery of the back yoke, and the refrigerant from the outside is guided to refrigerant flow passages 203 provided in the inner region of the back yoke via refrigerant flow passages 202. On the other hand, in the second embodiment, refrigerant flow passages 205 extending in the circumferential direction are provided on the outer periphery of the back yoke, and the refrigerant is guided to refrigerant flow passages 203 in the inner region, thereby suppressing torque reduction caused by the refrigerant flow passages.

[0050] Fig. 25 is a diagram showing the torque improvement rate similar to that in Fig. 16, and shows the torque improvement rate when Δ=0 in a comparative example (when no refrigerant flow path is provided) as a reference (0%). In Fig. 25, line L3 shown by a solid line shows the torque improvement rate when core blocks 200G and 200H are used. Line L4 shown by a dashed dotted line shows the torque improvement rate when refrigerant flow paths 203 and 205 are alternately arranged at a pitch θ, as in core block 200K shown in Fig. 26.

[0051] Fig. 27 is a diagram showing the magnetic flux density distribution when core blocks 200G and 200H shown in Figs. 21 to 23 are used. Fig. 28 is a diagram showing the magnetic flux density distribution when core block 200K is used. By alternately arranging refrigerant flow paths 203 and 205, the magnetic flux density distribution is improved, and as shown in Fig. 25, torque is improved compared to the comparative example.

[0052] In a configuration in which radially extending refrigerant channels 202, 203 are alternately arranged, such as in core blocks 200C, 200D shown in Figures 8 and 9, torque improvement is greatest when the connection position of refrigerant channels 202, 203 is at the center of the width direction of the back yoke (Δ=0), as shown in Figure 16. On the other hand, in a configuration in which circumferentially extending refrigerant channels 205 and radially extending refrigerant channels 203 are alternately arranged, such as in the second embodiment, torque improvement increases as the connection position of refrigerant channels 203, 205 approaches the inner periphery of the back yoke, as shown in Figure 25. Based on the change trends of lines L3, L4 in Figure 25, it is preferable to set the connection position (first region E1) of refrigerant channels 203, 205 closer to the inner periphery than the center of the back yoke.

[0053] (Third embodiment) 29 to 34 are diagrams illustrating a third embodiment. In the first and second embodiments described above, for example, the stator 2 is fixed to the inner circumferential portion of the case 4 as shown in FIGS. 1 and 2. In the third embodiment, as shown in FIG. 29, each of the core blocks 410A, 400A, 400B, and 410B provided in the stator core 20 includes a fastening portion 409 protruding from the outer periphery of the stator core 20 (i.e., the core blocks 410A, 400A, 400B, and 410B). The fastening portion 409 has a fastening hole 408 formed therein, as will be described later. Then, the stator 2 is fixed to a stator fixing portion 412 on the case side by inserting a bolt 420 into each of the fastening holes 408 in the core blocks 410A, 400A, 400B, and 410B.

[0054] Fig. 30 is a front view of a laminated body formed by stacking core blocks 400A and 400B. Fig. 31 is a front view of core block 400A. Fig. 32 is a front view of core block 400B. Fig. 33 is a front view of core block 410A. As shown in Fig. 31, core block 400A has refrigerant flow paths 203, 204, 205, and 206 formed therein, similar to those in core block 200E shown in Fig. 18. Core block 400A further has the above-mentioned fastening portion 409 Each fastening portion 409 is provided with the fastening hole 408 described above. One of the fastening portions 409 is formed with a refrigerant supply hole 207, and the refrigerant is supplied to the refrigerant supply hole 207. introduction One of the paths 206 is in communication.

[0055] As shown in Fig. 32, the core block 400B is provided with refrigerant flow paths 203, 204, and 205 similar to those of the core block 200F shown in Fig. 19. The core blocks 400A and 400B of Figs. 31 and 32 are stacked as shown in Fig. 30. Both circumferential end regions of the refrigerant flow path 205 of the stacked core block 400A are arranged to face one end of the circumferentially adjacent refrigerant flow path 205 provided in the core block 400B. As a result, the refrigerant flow path 205 of the core block 400A communicates with the refrigerant flow path 205 of the core block 400B, forming an annular flow path.

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

[0057] As shown in Fig. 33, the core block 410A has a refrigerant flow path 204 formed therein, similar to that of the core block 210 shown in Fig. 6. Furthermore, each fastening portion 409 has a refrigerant supply hole 207 and a fastening hole 408 formed therein. Although not shown, the core block 410B has a configuration in which the refrigerant supply hole 207 is removed from the core block 410A.

[0058] Fig. 34 is a cross-sectional view taken along D4-D4 in Fig. 30. Note that while Fig. 30 does not show core blocks 410A, 410B and stator coils 21 in slots 201, Fig. 34 also shows core blocks 410A, 410B and stator coils 21. A refrigerant introduction hole 412a for introducing a refrigerant from the outside is formed in stator fixing portion 412 to which stator core 20 is fixed, at a position facing refrigerant supply hole 207 of core block 410A.

[0059] The refrigerant introduced from the refrigerant introduction hole 412a of the stator fixing portion 412 flows from the refrigerant supply hole 207 of the core block 410A to the refrigerant supply hole 207 of the core block 400A. introduction The coolant flows into the coolant flow path 205 through the passage 206. The coolant flow path 205 faces the outer peripheral end region of the coolant flow path 203 of the core block 400B, and the coolant in the coolant flow path 205 flows into the coolant flow path 203.

[0060] The inner peripheral end region of the refrigerant flow path 203 of the core block 400B faces the refrigerant flow paths 204 of the core blocks 400A and 410B. Therefore, the refrigerant in the refrigerant flow path 203 flows through the refrigerant flow path 204 of the core block 410B to the right in the figure 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 the core block 400B to the refrigerant flow path 204 of the core block 400A flows through the refrigerant flow paths 204 of the core blocks 400A and 410A to the left in the figure 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 the fastening portions 409 provided on the outer periphery of the core block are fixed to the stator fixing portions 412 on the case side. In a rotating electric machine configured in this manner, as in the second embodiment, the refrigerant flow paths extending in the circumferential direction and the refrigerant flow paths extending in the radial direction are alternately arranged at equal pitches in the circumferential direction, thereby improving cooling performance by providing the refrigerant flow paths and suppressing torque reduction due to the influence of the refrigerant flow paths.

[0062] Furthermore, in a configuration including fastening portion 409, coolant can be introduced into stator core 20 from the end face of fastening portion 409 using coolant introduction hole 412a of stator fixing portion 412. In this case, by arranging coolant supply hole 207 near fastening hole 408, it is possible to improve sealing by fastening to the case with a bolt. Also, it is possible to eliminate the effect of coolant supply hole 207 on torque reduction.

[0063] The effects of the above-described embodiment and modified examples can be summarized as follows.

[0064] (1) As shown in FIGS. 1 to 6, etc., a rotating electric machine 1 is a rotating electric machine including a rotor 3 and a stator 2 having a plurality of slots 201. A stator core 20 of the stator 2 has first and second core blocks 200A and 200B stacked in an axial direction. The core blocks 200A and 200B are alternately arranged at a predetermined angular pitch θ in the circumferential direction of the stator. The core blocks 200A and 200B each have a plurality of refrigerant flow paths (first flow paths) 202 and refrigerant flow paths (second flow paths) 203 extending in the radial direction of the stator. The refrigerant flow paths 202 are connected to a refrigerant supply port 201. and extends from the outer periphery of the core to a first region (predetermined radial region) E1 on the radially inner side, 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 side, and the core blocks 200A and 200B are stacked in the axial direction so that the inner end region of the refrigerant flow path 202 of the core block 200A is connected to the outer end region of the refrigerant flow path 203 of the core block 200B, and the inner end region of the refrigerant flow path 202 of the core block 200B is connected to the outer end region of the refrigerant flow path 203 of the core block 200A.

[0065] As described above, in each of core blocks 200A and 200B, multiple refrigerant flow paths 202 and 203 extending in the radial direction of the stator are alternately arranged at a predetermined angular pitch θ in the circumferential direction of the stator. The multiple refrigerant flow paths 202 extend from the outer periphery 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 a region near the slots. As a result, torque reduction can be suppressed while improving the cooling efficiency of the refrigerant.

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

[0067] (3) As shown in FIGS. 1, 17 to 25, etc., a rotating electric machine 1 is a rotating electric machine including a rotor 3 and a stator 2 having a plurality of slots 201, and a stator core 20 of the stator 2 has first and second core blocks 200E and 200F stacked in the axial direction, and each of the core blocks 200E and 200F communicates with a plurality of refrigerant flow paths (first flow paths) 205 and a refrigerant flow path (second flow path) 203 that are alternately arranged at a pitch (predetermined angular pitch) 3θ in the circumferential direction of the stator, and communicates with any one of the plurality of refrigerant flow paths 205 to supply a refrigerant from the outside. The core blocks 200E and 200F are stacked in the axial direction such that the refrigerant flow path 205 of the core block 200E is connected to 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 is connected to 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 paths 205 extending in the circumferential direction of the stator and the refrigerant flow paths 203 located closer to the core inner circumference than the refrigerant flow paths 205 and extending in the radial direction at a predetermined angular pitch in the circumferential direction of the stator, it is possible to improve the cooling efficiency of the refrigerant while suppressing torque reduction.

[0069] (4) In the above (3), as shown in Figures 21 to 25, the first region E1 is preferably located closer to the core inner periphery than the approximate midpoint between the outer periphery of the slot 201 and the outer periphery of the stator core 20 (i.e., Δ=0). By setting it in this way, the torque improvement rate can be increased as shown in Figure 25, that is, the torque reduction due to the influence of the refrigerant flow path can be minimized.

[0070] (5) In the above (1) or (3), as shown in Figures 3 to 5, each of the core blocks 200A and 200B further includes a plurality of refrigerant flow paths (third flow paths) 204 that are provided in the second region E2 and penetrate the core axial direction, and the refrigerant flow paths 204 of the core block 200A communicate with the inner peripheral end regions of the refrigerant flow paths 203 of the core block 200B, and the refrigerant flow paths 204 of the core block 200B communicate with the inner peripheral end regions of the refrigerant flow paths 203 of the core block 200A. The refrigerant flowing through the refrigerant flow paths 204 near the slots can improve the cooling efficiency of the stator coils 21 in the slots 201.

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

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

[0073] (8) In (3) above, as shown in Figures 17 to 19, when integer N is an integer equal to or greater than 2, it is preferable that the slots 201 are arranged at an angular pitch θ around the stator circumferential direction, the predetermined angular pitch is set to a value N times the angular pitch θ, and the refrigerant flow paths 203 arranged between the refrigerant flow paths 205 are made up of N radially extending flow paths arranged at the angular pitch θ around the stator circumferential direction. By configuring in this way, it is possible to form refrigerant flow paths that communicate with each other in a single rotation.

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

[0075] The various embodiments and modifications described above are merely examples, and the present invention is not limited to these unless the features of the invention are impaired. Other embodiments that are 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 to 200K, 210, 400A, 400B, 410A, 410B... core block, 201... slot, 202 to 205, 421... refrigerant flow path, 206... refrigerant introduction path, 207... refrigerant supply hole, 408... fastening hole, 409... fastening portion, 412... stator fixing portion, 420... through hole, E1... first region, E2... second region

Claims

1. A rotating electric machine including a rotor and a stator having a plurality of slots, a stator core of the stator having first and second core blocks stacked in an axial direction; Each of the first and second core blocks includes a plurality of first and second flow paths that are alternately arranged at a predetermined angular pitch in the circumferential direction of the stator and extend in the radial direction of the stator, The first flow path is supplied with a refrigerant from an external source and extends from an outer periphery of the core to a predetermined radial region on the radially inner periphery side, the second flow passage extends from the predetermined radial region to a region near the slot on the radially inner circumferential side, the first and second core blocks are stacked in the axial direction such that an inner peripheral end region of the first flow path of the first core block communicates with an outer peripheral end region of the second flow path of the second core block, and such that an inner peripheral end region of the first flow path of the second core block communicates with an outer peripheral end region of the second flow path of the first core block, Each of the first and second core blocks further includes a plurality of third flow passages provided in the slot vicinity region and penetrating therethrough in the core axial direction, the third flow passage of the first core block communicates with an inner peripheral end region of the second flow passage of the second core block, a third flow passage of the second core block communicating with an inner peripheral end region of the second flow passage of the first core block;

2. 2. The rotating electric machine according to claim 1, a rotating electric machine characterized in that the inner peripheral end region of the first flow passage and the outer peripheral end region of the second flow passage, which are connected to each other, are located approximately midway between the outer peripheral end of the slot and the outer periphery of the stator core.

3. In the rotating electric machine according to claim 1, the stator core further includes a third core block having a plurality of fourth flow passages at both axial ends of the stacked first and second core blocks, a fourth flow passage passing through the third core block in the axial direction and communicating with the third flow passage of the first or second core block adjacent thereto;

4. In the rotating electric machine according to claim 1, The rotating electric machine, wherein the second flow path extends from the region near the slot to the slot.

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