Rotary electric machine

Abstract

To provide a rotary electric machine capable of uniformly cooling coil ends.SOLUTION: Disclosed is a rotary electric machine 10 having a stator 13, a rotor 12 which is coupled to a rotary shaft 11, and a casing 14. A stator coil 22 has coil ends 21a and 21b protruding axially outside from a stator core 20. Inside of the casing, there are provided a first coolant discharge mechanism 30 which discharges a coolant to one coil end and a second coolant discharge mechanism 40 which discharges a coolant to the other coil end. The first coolant discharge mechanism has an annular first coolant flow passage 32 enclosing the rotary shaft and having a plurality of discharge holes 50, and the second coolant discharge mechanism includes an annular second coolant flow passage 42 enclosing the rotary shaft and having a plurality of discharge holes 50.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electric machine. [Background technology]

[0002] Rotating electric machines incur losses such as copper loss, iron loss, and mechanical loss as they rotate, and these losses generate heat. If this heat causes the rotating electric machine to become excessively hot, it can cause deterioration of components and demagnetization of permanent magnets. To suppress heat generation in rotating electric machines, a technique has been proposed in which a coolant, such as cooling oil, is sprayed onto the coil ends that protrude axially outward from the stator core. For example, a cooling structure has been disclosed in which, for a rotating electric machine installed with its rotating shaft oriented horizontally, coolant is sprayed onto only the upper coil ends in the vertical direction, and the coolant flows by gravity to the lower coil ends in the vertical direction to cool the coil ends (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6760099 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional rotating electric machines, the coolant is sprayed only above the coil ends, which can result in insufficient coolant reaching the coil ends located below the rotating shaft, potentially reducing the cooling performance for the lower coil ends. Furthermore, when the coolant comes into contact with the coil ends, heat from the coil ends is transferred to the coolant, causing the temperature of the coolant to rise. Therefore, in conventional rotating electric machines, the temperature of the coolant flowing below the coil ends is higher than the temperature of the coolant flowing above the coil ends. Thus, in conventional rotating electric machines, there is a difference in cooling performance between the upper coil ends and the lower coil ends, resulting in the problem of insufficient cooling of the coil ends.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a rotating electric machine that can uniformly cool coil ends. [Means for solving the problem]

[0006] The rotating electric machine of the present disclosure is a rotating electric machine having a stator, a rotor fastened to a rotating shaft supported rotatably relative to the stator, and a casing that seals the stator and rotor, wherein the stator has a stator core with a plurality of teeth and a stator coil wound around the plurality of teeth, the stator coil has coil ends at both axial ends that protrude axially outward from the stator core, and is provided with a first coolant discharge mechanism inside the casing that discharges coolant from the axial outside to one coil end, and a second coolant discharge mechanism that discharges coolant from the axial outside to the other coil end, wherein the first coolant discharge mechanism has a first annular coolant flow path that surrounds the rotating shaft and has a plurality of discharge holes, and the second coolant discharge mechanism has a second annular coolant flow path that surrounds the rotating shaft and has a plurality of discharge holes. [Effects of the Invention]

[0007] The rotating electric machine of the present disclosure has a first coolant discharge mechanism inside a casing that discharges coolant from the axial outside to one coil end, and a second coolant discharge mechanism that discharges coolant from the axial outside to the other coil end, the first coolant discharge mechanism having an annular first coolant flow path surrounding the rotating shaft and having multiple discharge holes, and the second coolant discharge mechanism having an annular second coolant flow path surrounding the rotating shaft and having multiple discharge holes, so that the coil ends can be cooled uniformly. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a rotating electric machine according to a first embodiment. [Figure 2] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. [Figure 3] 4 is a diagram for explaining a first coolant discharge mechanism in the rotary electric machine according to the first embodiment. FIG. [Figure 4] 5 is a diagram for explaining a second coolant discharge mechanism in the rotary electric machine according to the first embodiment. FIG. [Figure 5] 10 is a diagram for explaining a first coolant discharge mechanism in a rotary electric machine according to a second embodiment. FIG. [Figure 6] 10 is a diagram for explaining a second coolant discharge mechanism in the rotary electric machine according to the second embodiment. FIG. [Figure 7] 10 is a diagram for explaining a second coolant discharge mechanism in the rotary electric machine according to the third embodiment. FIG. [Figure 8] 8 is an enlarged cross-sectional view of a portion indicated by AA in FIG. 7 in a rotary electric machine according to a third embodiment. [Figure 9] 8 is an enlarged cross-sectional view of a portion indicated by BB in FIG. 7 in the rotary electric machine according to the third embodiment. [Figure 10] 10 is a diagram for explaining a second coolant discharge mechanism in a rotary electric machine according to a fourth embodiment. FIG. [Figure 11] FIG. 11 is a cross-sectional view of a rotating electric machine according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a rotating electric machine according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that the same reference numerals in the various drawings indicate the same or corresponding parts.

[0010] Embodiment 1 FIG. 1 is a perspective view of a rotating electric machine according to the first embodiment. FIG. 2 is a cross-sectional view of the rotating electric machine according to the present embodiment. The rotating electric machine according to the present embodiment is a rotating electric machine mounted on an electric vehicle, such as a hybrid vehicle or an electric vehicle. In an electric vehicle, the rotating electric machine may be used as a traction generator for propelling the vehicle, or as a power generator for generating electricity using regenerative braking force and surplus power of the engine. In FIGS. 1 and 2, the Z-axis direction is vertical, and the X-axis and Y-axis directions are horizontal. In the rotating electric machine according to the present embodiment, the Y-axis direction is parallel to the rotation axis of the rotating electric machine 10.

[0011] As shown in FIGS. 1 and 2 , a rotating electric machine 10 according to this embodiment includes a rotating shaft 11, a rotor 12 fastened to the rotating shaft 11, a stator 13 disposed on the outer diameter side of the rotor 12 via a gap, and a casing 14 that accommodates these components. The rotating shaft 11 is rotatably supported by the casing 14 via bearings 27. The rotor 12 is an annular member including a rotor core made of laminated steel plates or the like and a plurality of permanent magnets embedded in the rotor core. The rotor 12 is fastened to the rotating shaft 11 and rotates integrally with the rotating shaft 11. Hereinafter, the direction parallel to the rotating shaft 11 will be referred to as the axial direction, the direction perpendicular to the rotating shaft 11 as the radial direction, and the direction in which the rotating shaft 11 rotates as the circumferential direction. The inner diameter side is the direction radially approaching the rotating shaft 11, and the outer diameter side is the direction radially away from the rotating shaft 11.

[0012] The stator 13 includes a stator core 20 and a stator coil 22. The stator core 20 is an annular member made of laminated steel plates or the like. The stator core 20 includes a annular yoke and a plurality of teeth protruding radially inward from the inner circumferential surface of the yoke. A winding constituting the stator coil 22 is wound around each tooth. The winding method may be concentrated winding, in which one winding is wound around one tooth, or distributed winding, in which one winding is wound across multiple teeth. In either case, coil ends 21a and 21b are present at both axial ends of the stator 13, and are portions of the stator coil 22 where the winding protrudes axially outward from the axial end face of the stator core 20.

[0013] The stator coil 22 is configured by connecting six-phase coils (U1 phase, V1 phase, W1 phase, U2 phase, V2 phase, and W2 phase). Ends of each of the six-phase stator coils are connected to input / output terminals 23. The input / output terminals 23 are attached to one axial end of the casing 14. The input / output terminals 23 are attached to the outer diameter side of the coil ends 21a. The input / output terminals 23 electrically connect each of the six-phase stator coils 22 to an externally provided inverter. Hereinafter, of both axial sides of the rotating electric machine 10, the side on which the input / output terminals 23 are provided (the positive side in the Y-axis direction in FIG. 1) will be referred to as the "terminal side," and the opposite side (the negative side in the Y-axis direction in FIG. 1) will be referred to as the "non-terminal side." Note that, although the rotating electric machine 10 of this embodiment has six-phase coils, the present invention is not limited to this as long as it has coil ends.

[0014] The casing 14 has a case body 24, a terminal-side cover 25, and a non-terminal-side cover 26. A first discharge plate 34 is attached to the inner surface of the terminal-side cover 25, and a second discharge plate 44 is attached to the inner surface of the non-terminal-side cover 26. The case body 24 is a cylindrical member with openings on both axial sides. The terminal-side cover 25 and the non-terminal-side cover 26 are members that cover the openings of the case body 24 and are fastened to the case body 24 by fastening means such as bolts. The internal space covered by the case body 24, the terminal-side cover 25, and the non-terminal-side cover 26 is an enclosed space through which a coolant, described below, circulates.

[0015] A first coolant discharge mechanism 30, which is made up of the terminal-side cover 25 and a first discharge plate 34, is formed on the surface of the terminal-side cover 25 facing the terminal-side coil end 21a. A second coolant discharge mechanism 40, which is made up of the non-terminal-side cover 26 and a second discharge plate 44, is formed on the surface of the non-terminal-side cover 26 facing the non-terminal-side coil end 21b. The first coolant discharge mechanism 30 is made up of grooves formed in the first discharge plate 34, which form flow paths for the coolant. Similarly, the second coolant discharge mechanism 40 is made up of grooves formed in the second discharge plate 44, which form flow paths for the coolant. Next, the first coolant discharge mechanism 30 and the second coolant discharge mechanism 40 will be described in detail.

[0016] 2, the first coolant discharge mechanism 30 is composed of a first coolant flow path 32 formed between the terminal side cover 25 and the first discharge plate 34, and a first channel 33 that communicates with a coolant supply hole 52 formed in the terminal side cover 25. A coolant supply pipe 51 is connected to the coolant supply hole 52 for supplying coolant from outside the terminal side cover 25. As the coolant, for example, insulating cooling oil can be used.

[0017] Fig. 3 is a diagram illustrating the first coolant discharge mechanism in the rotating electric machine of this embodiment. Fig. 3 is a diagram showing the positional relationship between the first coolant flow path 32 and the first channel 33 constituting the first coolant discharge mechanism 30 and the terminal-side coil end 21a, as viewed from the outside in the axial direction. Note that the first discharge plate 34 is omitted in Fig. 3 to avoid complexity.

[0018] As shown in FIG. 3, the first coolant flow path 32 is a substantially annular groove extending circumferentially at a position axially opposite the terminal-side coil end 21a, and is formed to surround the rotating shaft 11. The first channel 33 is a groove extending vertically upward from the first coolant flow path 32 (toward the positive side of the Z-axis direction). As shown in FIG. 2, the first discharge plate 34 is provided with a hole 35 into which the pipe 53 fits. The first channel 33 and the hole 35 into which the pipe 53 fits are in communication. As shown in FIG. 1, the pipe 53 connects the first coolant discharge mechanism 30 and the second coolant discharge mechanism 40, and serves as a path for supplying a portion of the coolant supplied to the coolant supply hole 52 to the second coolant discharge mechanism 40. The pipe 53 is preferably disposed vertically above the stator 13.

[0019] The first discharge plate 34 is an annular plate that is sufficiently wider than the first coolant flow path 32. The first discharge plate 34 is tightly attached to the inner surface of the terminal-side cover 25. At this time, the first discharge plate 34 is in watertight contact with the inner surface of the terminal-side cover 25 and completely covers the first coolant flow path 32. As a result, the grooves formed in the first discharge plate 34 form a flow path through which the coolant flows between the terminal-side cover 25 and the first discharge plate 34. As shown in FIG. 2, the first coolant flow path 32 and the first channel 33 are in communication with each other.

[0020] The first discharge plate 34 has a plurality of discharge holes 50 arranged at intervals in the circumferential direction. Each discharge hole 50 penetrates the first discharge plate 34 in the thickness direction, and the coolant flowing through the first coolant flow path 32 is discharged to the outside through this discharge hole 50. Therefore, the coolant is discharged from the first coolant flow path 32 in the axial direction through the discharge hole 50, and the discharged coolant falls onto the coil end 21a on the terminal side.

[0021] 3, the first coolant flow path 32 has a first arc portion 32a formed on the upper side in the vertical direction (the positive side in the Z-axis direction) and a second arc portion 32b formed on the lower side in the vertical direction (the negative side in the Z-axis direction). The first coolant flow path 32 also has a third arc portion 32c between the first arc portion 32a and the second arc portion 32b, a first linear portion 32d connecting the first arc portion 32a and the third arc portion 32c, and a second linear portion 32e connecting the second arc portion 32b and the third arc portion 32c.

[0022] Furthermore, the first coolant flow path 32 has a third linear portion 32f that is connected to the first arc portion 32a and is located vertically above the first arc portion 32a (on the positive side in the Z-axis direction). The third linear portion 32f is disposed axially opposite the input / output terminal 23. A plurality of discharge holes 50 are formed in the first arc portion 32a, the second arc portion 32b, and the third linear portion 32f, aligned at intervals.

[0023] In the third straight portion 32f, one discharge hole 50 is formed axially opposite to each input / output terminal 23, and the coolant is discharged from each discharge hole 50 to each input / output terminal 23. In the present embodiment, one discharge hole 50 is formed for each of the six input / output terminals 23. Note that multiple discharge holes 50 may be provided for each input / output terminal 23. By providing multiple discharge holes 50, the cooling performance for the input / output terminals 23 can be improved.

[0024] As shown in FIG. 3, the radius of the first arc-shaped portion 32a is larger than the radius of the outer edge of the terminal-side coil end 21a. The radius of the second arc-shaped portion 32b is smaller than the radius of the inner edge of the terminal-side coil end 21a. Therefore, the multiple discharge holes 50 formed in the first arc-shaped portion 32a and the second arc-shaped portion 32b are located vertically above the terminal-side coil end 21a (on the positive side of the Z-axis). Therefore, the coolant discharged from the discharge holes 50 falls onto the vertically above the terminal-side coil end 21a (on the positive side of the Z-axis). The coolant discharged from the discharge holes 50 in the first arc-shaped portion 32a and the second arc-shaped portion 32b flows along the terminal-side coil end 21a due to gravity and spreads horizontally across the terminal-side coil end 21a.

[0025] As shown in Figure 2, the second coolant discharge mechanism 40 is composed of a second coolant flow path 42 formed between the non-terminal side cover 26 and a second discharge plate 44, and a second channel 43 communicating with a pipe 53.

[0026] Fig. 4 is a diagram illustrating the second coolant discharge mechanism in the rotating electric machine of this embodiment. Fig. 4 is a diagram showing the positional relationship between the second coolant flow path 42 and the second channel 43 constituting the second coolant discharge mechanism 40 and the coil end 21b on the non-terminal side, as viewed from the outside in the axial direction. Note that the second discharge plate 44 is omitted in Fig. 4 to avoid complexity.

[0027] As shown in Fig. 4, the second coolant flow path 42 is a substantially annular groove extending circumferentially at a position axially opposite the non-terminal coil end 21b, and is formed to surround the rotating shaft 11. The second channel 43 is a groove extending vertically upward from the second coolant flow path 42 (toward the positive side in the Z-axis direction). As shown in Fig. 2, the second discharge plate 44 is provided with a hole 45 into which the pipe 53 fits. The second channel 43 and the hole 45 into which the pipe 53 fits are in communication.

[0028] The second discharge plate 44 is an annular plate that is sufficiently wider than the second coolant flow path 42. The second discharge plate 44 is tightly fitted to the inner surface of the non-terminal side cover 26. At this time, the second discharge plate 44 is in watertight contact with the inner surface of the non-terminal side cover 26 and completely covers the second coolant flow path 42. As a result, a flow path through which the coolant flows is formed between the non-terminal side cover 26 and the second discharge plate 44 by the groove formed in the second discharge plate 44. As shown in FIG. 2, the second coolant flow path 42 and the second channel 43 are in communication with each other.

[0029] The second discharge plate 44 has a plurality of discharge holes 50 arranged at intervals in the circumferential direction. Each discharge hole 50 penetrates the second discharge plate 44 in the thickness direction, and the coolant flowing through the second coolant flow path 42 is discharged to the outside through this discharge hole 50. Therefore, the coolant is discharged in the axial direction from the second coolant flow path 42 through the discharge hole 50, and the discharged coolant falls onto the coil end 21b on the opposite terminal side.

[0030] 4, the second coolant flow path 42 has a first arc-shaped portion 42a formed on the upper side in the vertical direction (the positive side in the Z-axis direction) and a second arc-shaped portion 42b formed on the lower side in the vertical direction (the negative side in the Z-axis direction). The second coolant flow path 42 also has a third arc-shaped portion 42c between the first arc-shaped portion 42a and the second arc-shaped portion 42b, a first linear portion 42d connecting the first arc-shaped portion 42a and the third arc-shaped portion 42c, and a second linear portion 42e connecting the second arc-shaped portion 42b and the third arc-shaped portion 42c. A plurality of discharge holes 50 are formed in the first arc-shaped portion 42a and the second arc-shaped portion 42b, spaced apart from each other.

[0031] As shown in FIG. 4, the radius of the first arc-shaped portion 42a is larger than the radius of the outer edge of the non-terminal coil end 21b. The radius of the second arc-shaped portion 42b is smaller than the radius of the inner edge of the non-terminal coil end 21b. Therefore, the discharge holes 50 formed in the first arc-shaped portion 42a and the second arc-shaped portion 42b are located vertically above the non-terminal coil end 21b (on the positive side of the Z-axis). Therefore, the coolant discharged from the discharge holes 50 falls onto the vertically above the non-terminal coil end 21b (on the positive side of the Z-axis). The coolant discharged from the discharge holes 50 in the first arc-shaped portion 42a and the second arc-shaped portion 42b flows along the non-terminal coil end 21b due to gravity and spreads horizontally across the non-terminal coil end 21b. As can be seen from FIGS. 3 and 4, the second coolant discharge mechanism 40 has the same configuration as the first coolant discharge mechanism 30, except that the third straight portion 32f is removed.

[0032] As shown in FIG. 2, a coolant discharge hole 54 is formed in the bottom of the casing 14. The bottom of the casing 14 serves as a coolant reservoir, and the coolant collected there is supplied by a coolant pump (not shown) from the coolant discharge hole 54 through a coolant supply pipe 51 to a coolant supply hole 52 in the terminal-side cover 25. A portion of the coolant flowing in from the coolant supply hole 52 is supplied to the first coolant discharge mechanism 30, and the remainder of the coolant flowing in from the coolant supply hole 52 passes through a pipe 53 and is supplied to the second coolant discharge mechanism 40. The coolant supplied to the first coolant discharge mechanism 30 is discharged from the discharge hole 50 of the first coolant flow path 32 toward the terminal-side coil end 21a. The coolant supplied to the second coolant discharge mechanism 40 is discharged from the discharge hole 50 of the second coolant flow path 42 toward the non-terminal-side coil end 21b. The coolant discharged toward the terminal-side coil end 21a and the anti-terminal-side coil end 21b falls downward due to gravity and accumulates in a coolant reservoir at the bottom of the casing 14. The coolant that has accumulated in the coolant reservoir is cooled naturally in the casing 14 or forcibly by an oil cooler, and then supplied again to the first coolant discharge mechanism 30 and the second coolant discharge mechanism 40 via the coolant pump, coolant supply pipe 51, and coolant supply hole 52.

[0033] The diameter of the discharge holes 50 formed in the first coolant flow path 32 and the second coolant flow path 42 is preferably 0.5 mm or more and 3.0 mm or less. If the diameter of the discharge holes 50 is 0.5 mm or more, the amount of coolant discharged necessary to cool the coil ends can be ensured. However, if the diameter of the discharge holes 50 is larger than necessary, the amount of coolant discharged will be so large that some of it may fall onto the rotor, causing resistance to rotor rotation. Therefore, the diameter of the discharge holes 50 is more preferably 1.0 mm or more and 2.0 mm or less.

[0034] Furthermore, the intervals between the multiple discharge holes 50 formed in the first coolant flow path 32 and the second coolant flow path 42 are preferably 3° or more and 10° or less. If the intervals between the discharge holes 50 are 10° or less, the coolant is uniformly discharged to the coil ends. However, if the intervals between the discharge holes 50 are narrower than necessary, the coolant may be discharged excessively to the coil ends, and some of it may fall onto the rotor, causing resistance to the rotor's rotation. Therefore, it is more preferable that the intervals between the discharge holes 50 be 5° or more and 8° or less. In the rotating electric machine of this embodiment, the intervals between the discharge holes 50 are uniform, but the intervals between the discharge holes 50 may also be uneven.

[0035] As described above, the rotating electric machine of this embodiment has a first coolant discharge mechanism that discharges coolant from the axially outer side to the terminal-side coil end and a second coolant discharge mechanism that discharges coolant from the axially outer side to the non-terminal-side coil end. The first coolant discharge mechanism has a first annular coolant flow path that surrounds the rotating shaft and has multiple discharge holes, and the second coolant discharge mechanism has a second annular coolant flow path that surrounds the rotating shaft and has multiple discharge holes. Furthermore, the first coolant flow path and the second coolant flow path each have a first arc-shaped portion on the upper side in the vertical direction and a second arc-shaped portion on the lower side in the vertical direction, with the radius of the first arc-shaped portion being larger than the radius of the outer edge of the coil end and the radius of the second arc-shaped portion being smaller than the radius of the inner edge of the coil end.

[0036] In a rotating electric machine configured in this manner, the coolant is always discharged from vertically above the coil ends, allowing the coil ends to be cooled uniformly. In the rotating electric machine of this embodiment, the radii of the first arc-shaped portions of the first and second coolant flow paths are larger than the radii of the outer edges of the coil ends, and the radii of the second arc-shaped portions are smaller than the radii of the inner edges of the coil ends. However, the radii of the first arc-shaped portions and the second arc-shaped portions do not necessarily have to be different. Even if the radii of the first arc-shaped portions and the second arc-shaped portions are the same, coolant at the same temperature can be discharged to all coil ends in the circumferential direction, allowing the coil ends to be cooled uniformly.

[0037] Alternatively, the radius of the first arc portion may be larger than the center radius of the coil end, and the radius of the second arc portion may be smaller than the center radius of the coil end. In a rotating electric machine configured in this manner, the coolant discharged to the coil end is always discharged vertically above the center line of the coil end, thereby enabling the coil end to be cooled uniformly. Note that the center radius of the coil end refers to the radius of the radial center of the coil end.

[0038] In addition, as in the rotating electric machine of this embodiment, by making the radius of the first arc portion of each of the first coolant flow path and the second coolant flow path larger than the radius of the outer edge portion of the coil end and making the radius of the second arc portion smaller than the radius of the inner edge portion of the coil end, the following effects can be obtained.

[0039] Because coolant at the same temperature is always discharged from the vertically upper side to both the coil ends located vertically upper and lower, there is no difference in cooling performance between the upper coil ends and the lower coil ends, and the entire coil end can be cooled uniformly.

[0040] Furthermore, at the horizontal end of the coil end, the coolant discharged onto the coil end located vertically above flows along the coil end due to gravity, allowing the entire coil end to be cooled uniformly.

[0041] Furthermore, because the coolant is discharged to both the coil ends located vertically above and below the rotor, the amount of coolant discharged can be reduced, and as a result, less coolant falls on the rotor, reducing rotational resistance to the rotor.

[0042] In addition, in the rotating electric machine of this embodiment, the first coolant flow path and the second coolant flow path each have a third arc portion between the first arc portion and the second arc portion, and each have a first straight portion connecting the first arc portion and the third arc portion, and a second straight portion connecting the second arc portion and the third arc portion. In the first coolant flow path and the second coolant flow path configured in this manner, pressure loss of the coolant flowing through the flow path can be reduced. As a result, the pressure for circulating the coolant can be reduced, allowing the coolant pump to be made smaller.

[0043] Furthermore, in the rotating electric machine of this embodiment, the first coolant discharge mechanism has the third straight portion that discharges coolant to the input / output terminals, so that the input / output terminals can be cooled, thereby improving the cooling performance of the entire rotating electric machine.

[0044] As described above, the rotating electric machine of this embodiment includes a first coolant discharge mechanism that discharges coolant from the axially outer side to the terminal-side coil end and a second coolant discharge mechanism that discharges coolant from the axially outer side to the non-terminal-side coil end. The first coolant discharge mechanism has a first annular coolant flow path that surrounds the rotating shaft and has multiple discharge holes, and the second coolant discharge mechanism has a second annular coolant flow path that surrounds the rotating shaft and has multiple discharge holes. This eliminates any difference in cooling performance between the upper coil end and the lower coil end, allowing the entire coil end to be cooled uniformly. Furthermore, the rotating electric machine of this embodiment also improves cooling performance, allowing for more power to be input, thereby enabling higher output.

[0045] In the rotating electric machine of this embodiment, the first coolant flow path 32 through which the coolant flows between the terminal-side cover 25 and the first discharge plate 34 is formed by a groove formed in the first discharge plate 34, but the first coolant flow path 32 through which the coolant flows between the terminal-side cover 25 and the first discharge plate 34 may also be formed by a groove formed in the terminal-side cover 25. Similarly, with regard to the second coolant flow path 42, the second coolant flow path 42 through which the coolant flows between the non-terminal-side cover 26 and the second discharge plate 44 may also be formed by a groove formed in the non-terminal-side cover 26.

[0046] Embodiment 2 The structure of the rotating electric machine according to the second embodiment is similar to that of the rotating electric machine according to the first embodiment, but the structures of the first and second coolant discharge mechanisms are different from those of the first embodiment. Fig. 5 is a diagram illustrating the first coolant discharge mechanism in the rotating electric machine of this embodiment. Fig. 5 is a diagram showing the positional relationship between the first coolant flow path 32 and the first channel 33 constituting the first coolant discharge mechanism 30 and the terminal-side coil end 21a, as viewed from the outside in the axial direction. Note that the first discharge plate 34 is omitted in Fig. 5 to avoid complexity.

[0047] The shape of the first coolant flow path 32 of this embodiment is similar to that of the first coolant flow path of the first embodiment, but the shape of the discharge holes is different. As shown in FIG. 5, the first coolant flow path 32 has a first arc-shaped portion 32a formed on the upper side in the vertical direction (the positive side in the Z-axis direction) and a second arc-shaped portion 32b formed on the lower side in the vertical direction (the negative side in the Z-axis direction). Of the discharge holes 50 formed in the first arc-shaped portion 32a, the diameter of the discharge hole 50a on the vertically upper side is larger than the diameter of the discharge hole 50b on the vertically lower side. Of the discharge holes 50 formed in the second arc-shaped portion 32b, the diameter of the discharge hole 50a on the vertically upper side is larger than the diameter of the discharge hole 50b on the vertically lower side. Furthermore, the diameter of the discharge hole 50c formed in the third linear portion 32f is larger than the diameter of the discharge hole 50b on the vertically lower side of the first arc-shaped portion 32a.

[0048] Fig. 6 is a diagram illustrating the second coolant discharge mechanism in the rotating electric machine of this embodiment. Fig. 6 is a diagram showing the positional relationship between the second coolant flow path 42 and the second channel 43 constituting the second coolant discharge mechanism 40 and the coil end 21b on the non-terminal side, as viewed from the outside in the axial direction. Note that the second discharge plate 44 is omitted in Fig. 6 to avoid complexity.

[0049] The shape of the second coolant flow path 42 of this embodiment is similar to that of the second coolant flow path of the first embodiment, but the shape of the discharge holes is different. As shown in Fig. 6, the second coolant flow path 42 has a first arc-shaped portion 42a formed on the upper side in the vertical direction (the positive side in the Z-axis direction) and a second arc-shaped portion 42b formed on the lower side in the vertical direction (the negative side in the Z-axis direction). Of the discharge holes 50 formed in the first arc-shaped portion 42a, the diameter of the discharge hole 50a on the vertically upper side is larger than the diameter of the discharge hole 50b on the vertically lower side. Of the discharge holes 50 formed in the second arc-shaped portion 42b, the diameter of the discharge hole 50a on the vertically upper side is larger than the diameter of the discharge hole 50b on the vertically lower side.

[0050] In the first and second coolant discharge mechanisms, the coolant discharged to the coil end vertically above the first arc section flows due to gravity to the coil end vertically below. Therefore, if the same amount of coolant is discharged from the entire first arc section, a larger amount of coolant will come into contact with the coil end vertically below. Similarly, if the same amount of coolant is discharged from the entire second arc section, a larger amount of coolant will come into contact with the coil end vertically below. In the rotating electric machine of this embodiment, the amount of coolant discharged to the vertically below portion of the coil end in the first and second arc sections is less than the amount of coolant discharged to the vertically above portion of the coil end. Therefore, while the amount of coolant directly discharged to the vertically below coil end is less, the coolant discharged to the vertically above coil end flows due to gravity, so the difference between the amount of coolant contacting the vertically below coil end and the amount of coolant contacting the vertically above coil end is smaller. As a result, in the rotating electric machine of this embodiment, the entire coil end can be cooled more uniformly than in the rotating electric machine of the first embodiment.

[0051] Furthermore, because the amount of coolant discharged to the portions of the first and second arcuate portions vertically below the coil ends is reduced, the amount of coolant discharged can be further reduced, which in turn further reduces the amount of coolant that falls on the rotor, thereby further reducing rotational resistance to the rotor.

[0052] In the rotating electrical machine of this embodiment, the diameters of the discharge holes of the first arcuate portion and the second arcuate portion are divided into two stages, but may be divided into three or more stages.

[0053] Embodiment 3 The structure of the rotating electric machine according to the third embodiment is similar to that of the rotating electric machine according to the first embodiment, but the structures of the first and second coolant discharge mechanisms are different from those of the first embodiment. Fig. 7 is a diagram illustrating the second coolant discharge mechanism in the rotating electric machine of this embodiment. Fig. 7 is a diagram showing the positional relationship between the second coolant flow path 42 and the second channel 43 constituting the second coolant discharge mechanism 40 and the coil end 21b on the non-terminal side, as viewed from the outside in the axial direction. Note that the second discharge plate 44 is omitted in Fig. 7 to avoid complexity.

[0054] The shape of the second coolant flow path 42 of this embodiment is similar to that of the second coolant flow path of the first embodiment, but the shape of the discharge holes is different. As shown in FIG. 7, the second coolant flow path 42 has a first arc-shaped portion 42a formed on the upper side in the vertical direction (the positive side in the Z-axis direction) and a second arc-shaped portion 42b formed on the lower side in the vertical direction (the negative side in the Z-axis direction). The discharge holes formed in the first arc-shaped portion 42a and the second arc-shaped portion 42b are inclined in the vertical direction toward the coolant outlet. Specifically, the discharge holes 50d formed in the first arc-shaped portion 42a and the second arc-shaped portion 42b are inclined upward in the vertical direction toward the coolant outlet, and the discharge holes 50e are inclined downward in the vertical direction toward the coolant outlet. The discharge holes 50d inclined upward in the vertical direction and the discharge holes 50e inclined downward in the vertical direction are arranged alternately in the circumferential direction.

[0055] Figure 8 is an enlarged cross-sectional view of the area indicated by AA in Figure 7. As shown in Figure 8, discharge hole 50d is inclined vertically upward (toward the positive side of the Z-axis direction) toward the outlet of the coolant. As indicated by the dashed arrow in Figure 8, the coolant discharged from discharge hole 50d falls onto the stator core 20 side of coil end 21b.

[0056] Figure 9 is an enlarged cross-sectional view of the area indicated by BB in Figure 7. As shown in Figure 9, discharge hole 50e is inclined downward in the vertical direction (toward the negative side of the Z-axis direction) toward the outlet of the coolant. As indicated by the dashed arrow in Figure 9, the coolant discharged from discharge hole 50e falls onto the tip end side of coil end 21b.

[0057] Although not shown, the shape of the first coolant flow path in this embodiment is the same as the shape of the first coolant flow path in embodiment 1, and the shape of the discharge hole is the same as the shape of the discharge hole of the second coolant flow path in this embodiment shown in Figures 7 to 9.

[0058] In a rotating electric machine configured in this manner, the first coolant discharge mechanism and the second coolant discharge mechanism can discharge coolant uniformly in the axial direction of the coil end, thereby cooling the entire coil end more uniformly. Furthermore, in the rotating electric machine of this embodiment, improved cooling performance allows for more input of electric power, which also enables higher output.

[0059] In the rotating electric machine of this embodiment, the discharge holes inclined vertically upward toward the coolant outlet and the discharge holes inclined vertically downward toward the coolant outlet are alternately arranged, but they may be arranged randomly. Also, in the rotating electric machine of this embodiment, the inclination of the discharge holes is divided into two stages, but it may be divided into three or more stages.

[0060] Embodiment 4 The structure of the rotating electric machine according to the fourth embodiment is similar to that of the rotating electric machine according to the first embodiment, but the structures of the first and second coolant discharge mechanisms are different from those of the first embodiment. Fig. 10 is a diagram illustrating the second coolant discharge mechanism in the rotating electric machine of this embodiment. Fig. 10 is a diagram showing the positional relationship between the second coolant flow path 42 and the second channel 43 constituting the second coolant discharge mechanism 40 and the coil end 21b on the non-terminal side, as viewed from the outside in the axial direction. Note that the second discharge plate 44 is omitted in Fig. 10 to avoid complexity.

[0061] 10, in the rotating electric machine of this embodiment, discharge holes 50 are formed in the third arc portion 42c, the first straight portion 42d, and the second straight portion 42e of the second coolant flow path 42. In other words, the discharge holes 50 are formed throughout the entire second coolant flow path 42.

[0062] Although not shown, the shape of the first coolant flow path in this embodiment is the same as the shape of the first coolant flow path in embodiment 1, and the configuration of the discharge holes is the same as the configuration of the discharge holes of the second coolant flow path in this embodiment shown in Figure 10.

[0063] In a rotating electric machine configured in this manner, the first and second coolant discharge mechanisms can also discharge coolant to the horizontal ends of the coil ends, allowing for more uniform cooling of the entire coil end. Furthermore, in the rotating electric machine of this embodiment, improved cooling performance allows for more input power, making it possible to achieve higher output.

[0064] Embodiment 5. 11 is a cross-sectional view of a rotating electric machine according to embodiment 5. The configuration of the rotating electric machine of this embodiment is similar to the configuration of the rotating electric machine of embodiment 1, except for the structure of the pipe connecting the first coolant discharge mechanism and the second coolant discharge mechanism.

[0065] 11 , in the rotating electric machine of this embodiment, a plurality of discharge holes 50f are formed in pipe 53. Since pipe 53 is disposed vertically above stator 13, the coolant discharged from discharge holes 50f falls onto the outer diameter side of stator 13.

[0066] In a rotating electric machine configured in this manner, the stator can also be cooled. Therefore, in the rotating electric machine of this embodiment, the cooling performance of the entire rotating electric machine is improved, allowing more electric power to be input, and therefore higher output is also possible.

[0067] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A rotating electric machine having a stator, a rotor fastened to a rotary shaft supported rotatably relative to the stator, and a casing that seals the stator and the rotor, The stator includes a stator core having a plurality of teeth and a stator coil wound around the plurality of teeth, the stator coil has coil ends at both axial ends thereof that protrude outward in the axial direction from the stator core, a first coolant discharge mechanism disposed inside the casing that discharges coolant from the axially outer side to one of the coil ends, and a second coolant discharge mechanism that discharges coolant from the axially outer side to the other of the coil ends, the first coolant discharge mechanism has an annular first coolant flow path surrounding the rotary shaft and having a plurality of discharge holes; The rotating electric machine is characterized in that the second coolant discharge mechanism has an annular second coolant flow path that surrounds the rotating shaft and has a plurality of discharge holes. (Appendix 2) The rotating electric machine described in Appendix 1, characterized in that the rotating shaft is arranged in a direction parallel to the horizontal direction, the first coolant flow path and the second coolant flow path each have a first arc portion on the upper side in the vertical direction and a second arc portion on the lower side in the vertical direction, the radius of the first arc portion being larger than the center radius of the coil end, and the radius of the second arc portion being smaller than the center radius of the coil end. (Appendix 3) A rotating electric machine as described in Appendix 2, characterized in that the radius of the first arc portion is larger than the radius of the outer edge portion of the coil end, and the radius of the second arc portion is smaller than the radius of the inner edge portion of the coil end. (Appendix 4) The rotating electric machine according to Supplementary Note 2 or 3, wherein the first coolant flow path and the second coolant flow path each have a third arc portion between the first arc portion and the second arc portion, a first straight portion between the first arc portion and the third arc portion, and a second straight portion between the second arc portion and the third arc portion. (Appendix 5) 5. The rotating electric machine according to claim 4, wherein discharge holes are formed in the first straight portion, the second straight portion and the third arc portion of the first coolant flow path and the second coolant flow path. (Appendix 6) further comprising an input / output terminal electrically connected to the stator coil; The rotating electric machine according to any one of appendixes 2 to 5, characterized in that the input / output terminal is located on the outer diameter side of the one coil end, the first coolant flow path has a third straight portion communicating with the first arc portion at a position opposite the input / output terminal, and the third straight portion has a discharge hole that discharges coolant to the input / output terminal. (Appendix 7) 7. The rotating electric machine according to any one of claims 2 to 6, wherein, among the plurality of discharge holes formed in the first arc portion and the second arc portion, the diameter of the discharge holes formed on the upper side in the vertical direction is larger than the diameter of the discharge holes formed on the lower side in the vertical direction. (Appendix 8) A rotating electric machine as described in any one of appendixes 2 to 7, characterized in that the multiple discharge holes are a mixture of discharge holes that are inclined upward in the vertical direction toward the coolant outlet and discharge holes that are inclined downward in the vertical direction toward the coolant outlet. (Appendix 9) The rotating electric machine according to any one of appendixes 2 to 8, further comprising a first coolant supply path that supplies coolant from outside the casing to the first coolant discharge mechanism, and a second coolant supply path inside the casing that connects the first coolant discharge mechanism and the second coolant discharge mechanism. (Appendix 10) The rotating electric machine described in Appendix 9, characterized in that the second coolant supply path is arranged vertically above the stator, and a plurality of discharge holes are formed in the second coolant supply path.

[0068] While the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not exemplified are conceivable within the scope of the technology disclosed in this specification, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of another embodiment. [Explanation of symbols]

[0069] 10 rotating electric machine, 11 rotating shaft, 12 rotor, 13 stator, 14 casing, 20 stator core, 21a, 21b coil end, 22 stator coil, 23 input / output terminal, 24 case body, 25 terminal side cover, 26 non-terminal side cover, 27 bearing, 30 first coolant discharge mechanism, 32 first coolant flow path, 32a, 42a first arc portion, 32b, 42b second arc portion, 32c, 42c third arc portion, 32d, 42d first straight portion, 32e, 42e second straight portion, 33 first channel, 34 first discharge plate, 35, 45 hole, 40 second coolant discharge mechanism, 42 second coolant flow path, 43 second channel, 44 second discharge plate, 50 discharge hole, 51 coolant supply pipe, 52 coolant supply hole, 53 pipe, 54 coolant discharge hole.

Claims

1. A rotating electric machine having a stator, a rotor fastened to a rotary shaft supported rotatably relative to the stator, and a casing that seals the stator and the rotor, The stator includes a stator core having a plurality of teeth and a stator coil wound around the plurality of teeth, the stator coil has coil ends at both axial ends thereof that protrude outward in the axial direction from the stator core, a first coolant discharge mechanism disposed inside the casing that discharges coolant from an axially outer side to one of the coil ends, and a second coolant discharge mechanism that discharges coolant from an axially outer side to the other of the coil ends, the first coolant discharge mechanism has an annular first coolant flow path surrounding the rotary shaft and having a plurality of discharge holes; The rotating electric machine is characterized in that the second coolant discharge mechanism has an annular second coolant flow path surrounding the rotating shaft and having a plurality of discharge holes.

2. 2. The rotating electric machine according to claim 1, wherein the rotation axis is arranged in a direction parallel to the horizontal direction, the first coolant flow path and the second coolant flow path each have a first arc portion on the upper side in the vertical direction and a second arc portion on the lower side in the vertical direction, the radius of the first arc portion being larger than the center radius of the coil end, and the radius of the second arc portion being smaller than the center radius of the coil end.

3. 3. The rotating electric machine according to claim 2, wherein the radius of the first arc portion is larger than the radius of the outer edge of the coil end, and the radius of the second arc portion is smaller than the radius of the inner edge of the coil end.

4. 4. The rotating electric machine according to claim 2, wherein the first coolant flow path and the second coolant flow path each have a third arc portion between the first arc portion and the second arc portion, a first straight portion between the first arc portion and the third arc portion, and a second straight portion between the second arc portion and the third arc portion.

5. 5. The rotating electric machine according to claim 4, wherein discharge holes are formed in the first linear portion, the second linear portion and the third arc portion of the first and second coolant flow paths.

6. further comprising an input / output terminal electrically connected to the stator coil; 4. The rotating electric machine according to claim 2, wherein the input / output terminal is located on the outer diameter side of the one coil end, the first coolant flow path has a third straight portion communicating with the first arc portion at a position opposite the input / output terminal, and the third straight portion has a discharge hole for discharging coolant to the input / output terminal.

7. 4. The rotating electric machine according to claim 2, wherein, of the plurality of discharge holes formed in the first arc portion and the second arc portion, the diameter of the discharge holes formed on the upper side in the vertical direction is larger than the diameter of the discharge holes formed on the lower side in the vertical direction.

8. 4. The rotating electric machine according to claim 2, wherein the plurality of discharge holes are a mixture of discharge holes that are inclined upward in the vertical direction toward the outlet of the cooling liquid and discharge holes that are inclined downward in the vertical direction toward the outlet of the cooling liquid.

9. 4. The rotating electric machine according to claim 2, further comprising: a first coolant supply path that supplies coolant from the outside of the casing to the first coolant discharge mechanism; and a second coolant supply path that connects the first coolant discharge mechanism and the second coolant discharge mechanism inside the casing.

10. 10. The rotating electric machine according to claim 9, wherein the second coolant supply path is disposed vertically above the stator, and a plurality of discharge holes are formed in the second coolant supply path.

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