Rotating electric machines

Abstract

The purpose of the present invention is to provide a rotating electric machine in which an increase in the pressure loss of a refrigerant flowing through a cooling flow path can be suppressed. A refrigerant flow path of the stator 3 of the rotating electric machine 1 of the present invention has: a first refrigerant flow path 11 through which a refrigerant flows in the circumferential direction; second refrigerant flow paths 12A, 12B through which the refrigerant flows in the axial direction; third refrigerant flow paths 13A, 13B through which the refrigerant flows in the circumferential direction; and a refrigerant supply flow path 10. The refrigerant supply flow path 10 first supplies the refrigerant to the first refrigerant flow path 11. The first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13 are configured so that the refrigerant supplied to the first refrigerant flow path 11 flows from one second refrigerant flow path 12A to one third refrigerant flow path 13A and the refrigerant supplied to the first refrigerant flow path 11 flows from the other second refrigerant flow path 12B to the other third refrigerant flow path 13B.

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine having a cooling structure. [Background technology]

[0002] Patent Document 1 describes an electric motor in which a stator is pressure-molded by enclosing a channel model of the same shape as the cooling channel, made from wax or a low-melting-point alloy, inside a powder magnetic core material (see abstract). Paragraph 0024 and Figure 5 of Patent Document 1 describe a cascade-type channel model used to form the cooling channel. This channel model is made by interconnecting three ring-shaped channel models, multiple axial channel models, an inlet channel model, and an outlet channel model, resulting in a stator equipped with cascade-type cooling channels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-223277 Summary of the Invention [Problem to be solved by the invention]

[0004] The stator in Patent Document 1 has three ring-shaped cooling channels that allow the coolant to flow circumferentially around the stator, multiple axial cooling channels that allow the coolant to flow axially around the stator, and an inlet channel and an outlet channel. The three ring-shaped cooling channels are aligned axially, with the inlet channel connected to one of the two ring-shaped cooling channels located at both axial ends (the inlet-side ring-shaped cooling channel), and the outlet channel connected to the other ring-shaped cooling channel (the outlet-side ring-shaped cooling channel). Therefore, the coolant flowing from the inlet channel to the ring-shaped cooling channel in the inlet channel flows through the multiple axial cooling channels to a ring-shaped cooling channel (the intermediate ring-shaped cooling channel) located intermediate between the inlet-side ring-shaped cooling channel and the outlet-side ring-shaped cooling channel. It then flows through the multiple axial cooling channels to the outlet-side ring-shaped cooling channel. In other words, the cooling channel in Patent Document 1 has a configuration in which the inlet-side ring-shaped cooling channel, the intermediate ring-shaped cooling channel, and the outlet-side ring-shaped cooling channel are connected in series.

[0005] In the case of the cooling flow path of Patent Document 1, the three ring-shaped cooling flow paths are connected in series, so the pressure loss of the coolant flowing through the cooling flow paths becomes large.

[0006] An object of the present invention is to provide a rotating electrical machine capable of suppressing an increase in pressure loss of a coolant flowing through a cooling passage. [Means for solving the problem]

[0007] In order to achieve the above object, the rotating electric machine of the present invention comprises: a stator having a ring-shaped stator core and a coil wound around the stator core; a rotor including a rotating shaft, a rotor core to which the rotating shaft is fixed, and a magnet fixed to the rotor core, the rotor being disposed on the inner circumferential side of the stator; a refrigerant flow path through which a refrigerant for cooling the stator flows; a housing that accommodates the stator and the rotor; Equipped with The refrigerant flow path is a first refrigerant flow path through which a refrigerant flows in a circumferential direction surrounding the rotary shaft; a second refrigerant flow path that communicates with the first refrigerant flow path and through which a refrigerant flows along the axial direction of the rotary shaft; a third refrigerant flow path that communicates with the second refrigerant flow path and through which a refrigerant flows in a circumferential direction surrounding the rotating shaft; a refrigerant supply flow path that supplies a refrigerant to the first refrigerant flow path first among the first refrigerant flow path, the second refrigerant flow path, and the third refrigerant flow path, the third refrigerant flow path is provided at each of both ends of the stator core in the axial direction, the first refrigerant flow path is provided between two third refrigerant flow paths provided at both ends of the stator core in the axial direction, the second refrigerant flow path has one second refrigerant flow path provided so that one end thereof communicates with the first refrigerant flow path and the other end thereof communicates with one of the two third refrigerant flow paths, and the other second refrigerant flow path provided so that one end thereof communicates with the first refrigerant flow path and the other end thereof communicates with the other of the two third refrigerant flow paths, The first refrigerant flow path, the second refrigerant flow path, and the third refrigerant flow path are configured so that a refrigerant supplied to the first refrigerant flow path flows from one of the second refrigerant flow paths to one of the third refrigerant flow paths, and so that a refrigerant supplied to the first refrigerant flow path flows from the other of the second refrigerant flow paths to the other of the third refrigerant flow paths. 、 The second refrigerant flow path has a groove-shaped portion formed in an outer peripheral surface of the stator core, and the groove-shaped portion is covered by an inner peripheral surface of the housing, a plurality of the one second refrigerant flow paths and a plurality of the other second refrigerant flow paths are provided in the circumferential direction of the outer circumferential surface of the stator core, an inlet in one of the second refrigerant flow paths that communicates with the first refrigerant flow path and an inlet in the other of the second refrigerant flow paths that communicates with the first refrigerant flow path open to an outer circumferential surface of the stator core so as to face radially outward; The groove-shaped portion of one of the second refrigerant flow paths and the groove-shaped portion of the other of the second refrigerant flow paths are configured as continuous linear groove-shaped portions. do. [Effects of the Invention]

[0008] According to the present invention, it is possible to suppress an increase in pressure loss of the coolant flowing through the cooling passage, thereby improving the cooling effect of the rotating electrical machine.

[0009] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view showing a cross section along a central axis of a rotating electric machine according to an embodiment of the present invention; [Figure 2A] 1 is a conceptual diagram showing an outline of a cooling flow path in a rotating electric machine according to an embodiment of the present invention; [Figure 2B] 1 is a cross-sectional view showing a cross section along a central axis of a rotating electric machine according to an embodiment of the present invention; [Figure 3] 1 is a configuration diagram of a cooling system using a rotating electric machine according to an embodiment of the present invention; [Figure 4] 1 is a partial cross-sectional view showing, in an enlarged scale, a part of a cross section perpendicular to a central axis of a rotating electric machine according to an embodiment of the present invention; [Figure 5] 2 is a partially enlarged cross-sectional view of the rotating electric machine shown in FIG. 1 with a first housing removed. FIG. [Figure 6] 1 is a schematic cross-sectional view showing an example of a rotating electric machine according to the present invention in which a refrigerant inlet passage is disposed at a lower portion. [Figure 7] 1 is a schematic cross-sectional view showing an example of a rotating electric machine according to the present invention in which refrigerant inlet passages are arranged at an upper portion and a lower portion. [Figure 8] 1 is a schematic cross-sectional view showing an example of a rotating electrical machine according to the present invention in which a refrigerant inlet passage is arranged obliquely; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the direction along the central axis 1x of the rotating shaft 5 of the rotating electric machine 1 will be referred to as the axial direction. In this embodiment, the central axis 1x of the rotating shaft 5 coincides with both the central axis of the stator 3 and the central axis of the rotor 4, and the axial direction 1x is synonymous with the direction along the central axis of the stator 3 and the direction along the central axis of the rotor 4.

[0012] FIG. 1 is an exploded perspective view showing a cross section along the central axis of a rotating electrical machine 1 according to an embodiment of the present invention.

[0013] In the rotating electric machine 1, a stator 3 and a rotor 4 are housed in a housing 2 (2A, 2B). The housing 2 is composed of a first housing 2A and a second housing 2B. The second housing 2B is formed in a bottomed cylindrical shape with an opening 2Ba at one end in the direction along the central axis 1x and a bottom 2Bb at the other end, and has a cylindrical portion 2Bc between the opening 2Ba side and the bottom 2Bb side. The first housing 2A is assembled to the opening 2Ba side of the second housing 2B, which houses the stator 3 and the rotor 4, and closes the opening 2Ba of the second housing 2B.

[0014] The stator 3 has a cylindrical (annular) stator core 3a and a coil 7 wound around the stator core 3a. The stator core 3a is fitted to the inner periphery of the cylindrical portion 2Bc of the second housing 2B. The stator core 3a has a plurality of slots 3b on its inner periphery, and the coil 7 is wound around the slots 3b.

[0015] The stator 3 is inserted into the second housing 2B until it abuts against a stepped portion 2Bd formed on the inner circumferential surface of the cylindrical portion 2Bc of the second housing 2B. The first housing 2A also has a stepped portion (not shown) similar to the stepped portion 2Bd of the second housing 2B, and when the first housing 2A is assembled to the second housing 2B, the stator 3 is sandwiched between the stepped portion of the first housing 2A and the stepped portion 2Bd of the second housing 2B.

[0016] The rotor 4 has a rotating shaft 5, a rotor core 4a to which the rotating shaft is fixed, and magnets (permanent magnets) 8 fixed to the rotor core 4a. The rotor 4 is disposed on the inner peripheral side of the stator 3 so that its outer peripheral surface faces the inner peripheral surface of the stator 3. The rotor 4 of this embodiment is an embedded magnet type rotor in which the magnets 8 are embedded in holes 4b provided in the rotor core 4a in a direction along the central axis 1x.

[0017] A rotating shaft 5 provided on the rotor 4 is journaled to the housing 2 by two bearings 6A and 6B. The bearing 6A is attached to the first housing 2A, and the bearing 6B is attached to the second housing 2B. The rotating shaft 5 protrudes a long distance from the first housing 2A side to the outside of the housing 2, and the output of the rotating electric machine 1 is extracted from the protruding portion of the rotating shaft 5.

[0018] The first housing 2A is provided on the side where the output of the rotating electric machine 1 is extracted, and is sometimes referred to as the front housing. The second housing 2B is sometimes referred to as the rear housing relative to the front housing 2A. The rotating electric machine 1 will be described with the side where the front housing 2A is provided as the front side in the axial direction 1x, and the side of the bottom 2Bb of the second housing 2B as the rear side.

[0019] In recent years, the power density of rotating electrical machines has increased, leading to higher loss densities. Temperature rise, particularly in the stator coil ends, is a problem due to increased losses caused by increased current, necessitating the establishment of efficient cooling methods. In oil-cooled structures, the coil ends are cooled by directly dripping or spraying coolant. Because the temperature of the coil ends depends on the amount of coolant supplied, efficient cooling of the coil ends requires a larger amount of coolant. The amount of coolant supplied depends on the geometric structure of the coolant flow path (cooling flow path) that supplies the coolant to the coil ends and the flow path pressure loss in the coolant flow path (cooling flow path). Therefore, to increase the amount of coolant supplied, it is necessary to optimize the geometric structure of the cooling flow path and reduce the pressure loss in the cooling flow path.

[0020] The cooling flow paths of the rotating electric machine 1 of this embodiment will be described with reference to Figures 2A and 2B. Figure 2A is a conceptual diagram showing an outline of the cooling flow paths 10, 11, and 12 of the rotating electric machine 1 according to one embodiment of the present invention. Figure 2B is a cross-sectional view showing a cross section along the central axis 1x of the rotating electric machine 1 according to one embodiment of the present invention. Note that arrows shown with solid or dashed lines in the figure indicate the flow of the refrigerant and also indicate the cooling flow paths through which the refrigerant flows.

[0021] The rotating electric machine 1 of this embodiment comprises a stator 3 having a circular ring-shaped stator core 3a and a coil 7 wound around the stator core 3a, a rotor 4 including a rotating shaft 5, a rotor core 4a to which the rotating shaft 5 is fixed, and a magnet 8 fixed to the rotor core 4a, and arranged on the inner periphery of the stator 3, and a refrigerant flow path through which a refrigerant flows to cool the stator.

[0022] The refrigerant flow path has a first refrigerant flow path 11, a second refrigerant flow path 12, a third refrigerant flow path 13, and a refrigerant supply flow path 10 (10A, 10B). The first refrigerant flow path 11 is configured so that the refrigerant flows in the circumferential direction surrounding the rotating shaft 5. The second refrigerant flow path 12 is connected to the first refrigerant flow path 11 and is configured so that the refrigerant flows in the axial direction of the rotating shaft 5. The third refrigerant flow path 13 is connected to the second refrigerant flow path 12 and is configured so that the refrigerant flows in the circumferential direction surrounding the rotating shaft 5. The refrigerant supply flow path 10 (10A, 10B) supplies the refrigerant to the first refrigerant flow path 11 first among the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13.

[0023] The refrigerant supply flow path 10A is formed in the housing 2A, and the refrigerant supply flow path 10B is formed in the housing 2B. When the housing 2A and the housing 2B are assembled together, the refrigerant supply flow path 10A and the refrigerant supply flow path 10B are combined to form a single refrigerant supply flow path.

[0024] In this embodiment, the third refrigerant flow paths 13 (13A, 13B) are provided on both end sides of the stator core 3 in the axial direction 1x (see FIG. 1). In this case, the third refrigerant flow path 13 includes one refrigerant flow path 13A arranged on the front side (the front housing 2A side) of the first refrigerant flow path 11, and one refrigerant flow path 13B arranged on the rear side (the bottom 2Bb side of the rear housing 2B) of the first refrigerant flow path 11.

[0025] The first refrigerant flow path 11 is configured as a single refrigerant flow path located at the center of the stator core 3a in the axial direction 1x. The first refrigerant flow path 11 is provided between two third refrigerant flow paths 13A, 13B provided at both ends of the stator core 3 in the axial direction 1x.

[0026] The number of first refrigerant flow paths 11 is not limited to one, and the number of third refrigerant flow paths 13 is not limited to two. However, by providing two third refrigerant flow paths 13A, 13B for one first refrigerant flow path 11, it is possible to realize a refrigerant flow path with improved cooling effect in a simple configuration.

[0027] The second refrigerant flow path 12 includes a second refrigerant flow path 12A arranged between the first refrigerant flow path 11 and the front third refrigerant flow path 13A, and a second refrigerant flow path 12B arranged between the first refrigerant flow path 11 and the rear third refrigerant flow path 13A.

[0028] The second refrigerant flow path 12A is disposed in front of the first refrigerant flow path 11, with one end connected to the first refrigerant flow path 11 and the other end connected to the front third refrigerant flow path 13A. As a result, the second refrigerant flow path 12A is configured so that the refrigerant supplied to the first refrigerant flow path 11 flows to the third refrigerant flow path 13A via the second refrigerant flow path 12A.

[0029] The second refrigerant flow path 12B is disposed rearward of the first refrigerant flow path 11, with one end connected to the first refrigerant flow path 11 and the other end connected to the rear third refrigerant flow path 13B. As a result, the second refrigerant flow path 12B is configured so that the refrigerant supplied to the first refrigerant flow path 11 flows into the third refrigerant flow path 13B via the second refrigerant flow path 12B.

[0030] As described above, the rotating electrical machine 1 of this embodiment has the following configuration. a stator 3 having an annular stator core 3a and a coil 7 wound around the stator core 3a; a rotor 4 including a rotating shaft 5, a rotor core 4a to which the rotating shaft 5 is fixed, and a magnet 8 fixed to the rotor core 4a, and disposed on the inner circumferential side of the stator 3; a refrigerant flow path through which a refrigerant for cooling the stator 3 flows, This refrigerant flow path is a first refrigerant flow path 11 through which a refrigerant flows in a circumferential direction surrounding the rotating shaft 5; a second refrigerant flow path 12 communicating with the first refrigerant flow path 11 and through which a refrigerant flows along the axial direction of the rotating shaft 5; a third refrigerant flow path 13 that communicates with the second refrigerant flow path 12 and through which a refrigerant flows in a circumferential direction surrounding the rotating shaft 5; a refrigerant supply flow path 10 (10A, 10B) that first supplies a refrigerant to the first refrigerant flow path 11 among the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13; The third refrigerant flow paths 13 (13A, 13B) are provided on both end sides of the stator core 3 in the axial direction 1x (see FIG. 1 ), The first refrigerant flow path 11 is provided between two third refrigerant flow paths 13A and 13B provided at both end sides of the stator core 3 in the axial direction 1x, The second refrigerant flow path 12 has one second refrigerant flow path 12A, one end of which is connected to the first refrigerant flow path 11 and the other end of which is connected to one third refrigerant flow path 13A of the two third refrigerant flow paths 13A, 13B, and the other second refrigerant flow path 12B, one end of which is connected to the first refrigerant flow path 11 and the other end of which is connected to the other third refrigerant flow path 13B of the two third refrigerant flow paths 13A, 13B, The first refrigerant flow path 11, the second refrigerant flow path 12 and the third refrigerant flow path 13 are configured so that the refrigerant supplied to the first refrigerant flow path 11 flows from one of the second refrigerant flow paths 12A to one of the third refrigerant flow paths 13A, and so that the refrigerant supplied to the first refrigerant flow path 11 flows from the other of the second refrigerant flow paths 12B to the other of the third refrigerant flow paths 13B.

[0031] In this case, a plurality of second refrigerant flow paths (one second refrigerant flow path) 12A and a plurality of second refrigerant flow paths (the other second refrigerant flow path) 12B are provided in the circumferential direction of the outer circumferential surface of the stator core 3a.

[0032] The rotating electric machine 1 of this embodiment further has a communication passage 14 as a refrigerant flow path. The communication passage 14 includes a communication passage 14A and a communication passage 14B. The communication passage 14A is a communication passage that connects the third refrigerant flow path 13A with the internal space 2Aa of the housing 2A. A coil end portion 7A formed on one end face of the stator core 3a is arranged in the internal space 2Aa of the housing 2A. The communication passage 14B is a communication passage that connects the third refrigerant flow path 13B with the internal space 2Ba of the housing 2B. A coil end portion 7B formed on the other end face of the stator core 3a is arranged in the internal space 2Ba of the housing 2B.

[0033] The communicating passage 14A is formed across the housings 2A and 2B, with most of it being formed in the housing 2A. The communicating passage 14B is formed in the housing 2B. The communicating passages 14A and 14B are provided above the top of the coil end portions 7 (7A, 7B). The communicating passage 14A drips the refrigerant into the coil end portion 7A from an outlet located above the coil end portion 7A. The communicating passage 14B drips the refrigerant into the coil end portion 7B from an outlet located above the coil end portion 7B.

[0034] The communication passages 14A and 14B form a refrigerant dripping flow path (refrigerant dripping portion) that drips the refrigerant into the coil end portions 7 (7A and 7B).

[0035] That is, the rotating electric machine 1 of this embodiment has one communication passage 14A, one end of which is connected to one third refrigerant flow path 13A and the other end of which is connected to the internal space 2Aa of the housing 2 (2A) in which the coil end portion 7A formed on one end face side of the stator core 3a is arranged, and the other communication passage 14B, one end of which is connected to the other third refrigerant flow path 13B and the other end of which is connected to the internal space 2Ba of the housing 2 (2B) in which the coil end portion 7B formed on the other end face side of the stator core 3a is arranged, and the one communication passage 14A and the other communication passage 14B are arranged above the top of the coil end portion 7 (7A, 7B).

[0036] In the rotating electric machine 1 of this embodiment, as shown in FIGS. 2A and 2B, The refrigerant supplied to the first refrigerant flow path 11 flows in the circumferential direction while contacting the outer peripheral surface of the stator core 3a, and is then divided into one of a plurality of second refrigerant flow paths 12A and the other of a plurality of second refrigerant flow paths 12B. The refrigerant that has been diverted to one of the plurality of second refrigerant flow paths 12A merges with one of the third refrigerant flow paths 13A, flows upward through one of the third refrigerant flow paths 13A, and reaches one of the communication paths 14A, The refrigerant that has been branched into the other plurality of second refrigerant flow paths 12B merges at the other third refrigerant flow path 13B, flows upward through the other third refrigerant flow path 13B, and reaches the other communication path 14B.

[0037] The rotating electric machine 1 of this embodiment further includes a first refrigerant discharge passage 15A and a second refrigerant discharge passage 15B as refrigerant passages. The first refrigerant discharge passage 15A is provided in the housing (first housing) 2A and constitutes a refrigerant discharge passage that connects the internal space 2Aa of the housing 2A to the outside of the housing 2A. The second refrigerant discharge passage 15B is provided in the housing (second housing) 2B and constitutes a refrigerant discharge passage that connects the internal space 2Ba of the housing 2B to the outside of the housing 2B. To discharge the refrigerant, the first refrigerant discharge passage 15A and the second refrigerant discharge passage 15B are provided in the lower part of the housing 2 (2A, 2B).

[0038] That is, in the rotating electric machine 1 of this embodiment, the first housing 2A has a first refrigerant discharge flow path 15A that discharges the refrigerant dripped onto the coil end portion 7A on one end face side of the stator core 3a to the outside of the first housing 2A, and the second housing 2B has a second refrigerant discharge flow path 15B that discharges the refrigerant dripped onto the coil end portion 7B on the other end face side of the stator core 3a to the outside of the second housing 2B.

[0039] Next, a cooling system according to this embodiment will be described with reference to Fig. 3. Fig. 3 is a configuration diagram of a cooling system using a rotating electrical machine according to one embodiment of the present invention.

[0040] In this embodiment, the coolant is pressure-fed to the rotating electrical machine 1 through a coolant flow path by an oil pump 21. A cooling unit 22 is provided in the coolant flow path, and the coolant pressure-fed by the oil pump 21 is cooled by the cooling unit 22. The coolant cooled by the cooling unit 22 is sent from the coolant supply flow path 10 to the first coolant flow path 11.

[0041] The refrigerant flows around the entire circumference of the stator core 3a through a first refrigerant flow path 11 located in the axial center of the stator core 3a, and then flows from the first refrigerant flow path 11 toward the axial end of the stator core 3a through a second refrigerant flow path 12. A third refrigerant flow path 13 located at the axial end of the stator core 3a merges the refrigerant flowing axially from the multiple second refrigerant flow paths 12 and guides them upward in the circumferential direction.

[0042] In this embodiment, the refrigerant supplied from the refrigerant supply passage 10 is widely diffused throughout the stator core 3a by the first refrigerant passage 11 and the second refrigerant passage 12. After flowing through the multiple second refrigerant passages 12 to cool the stator 3, the refrigerant is collected at the top of the stator 3 by the third refrigerant passage 13 and supplied to the coil end portions 7 (7A, 7B) from above the coil end portions 7 (7A, 7B). In this case, the refrigerant dispersed in the multiple second refrigerant passages 12 is collected by the third refrigerant passage 13 and supplied to the coil end portions 7 (7A, 7B). This refrigerant passage configuration increases the flow rate of the refrigerant supplied to the coil ends 7 (7A, 7B), improving the cooling performance of the coils.

[0043] Furthermore, by connecting the third refrigerant flow paths 13A, 13B located at both ends of the stator core 3a in parallel to the first refrigerant flow path 11, pressure loss in the refrigerant flow path is reduced, and the amount of refrigerant reaching the coil end upper parts 7A, 7B can be increased. Furthermore, by reducing pressure loss in the refrigerant flow path, a sufficient flow rate can be ensured even with a pump with low discharge capacity (a small pump).

[0044] The refrigerant supplied to the first refrigerant flow path 11 located at the axial center of the stator core 3a flows toward the third refrigerant flow paths 13A and 13B provided at both ends of the stator core 3a. In this case, the axial temperature gradient can be reduced compared to when the refrigerant is supplied in one direction from one end of the stator core 3a to the other end.

[0045] Next, the configurations of the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13 will be described in detail with reference to Figures 4 and 5 as well as Figures 1 and 2B. Figure 4 is a partial cross-sectional view showing, on an enlarged scale, a part of a cross section perpendicular to the central axis of a rotating electric machine according to an embodiment of the present invention. Figure 5 is a partial cross-sectional view showing, on an enlarged scale, a part of the rotating electric machine shown in Figure 1 with the first housing removed.

[0046] The rotating electric machine 1 of this embodiment is The motor includes a housing 2 (2A, 2B) that houses a stator 3 and a rotor 4, At least one of the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13 has a groove-shaped portion formed in the outer peripheral surface of the stator core 3a, and the groove-shaped portion is covered by the inner peripheral surface of the housing 2 (2B). The refrigerant flow path having a groove-shaped portion formed in the outer peripheral surface of the stator core 3a can directly cool the stator core 3a by bringing the refrigerant into direct contact with the surface of the stator core 3a, and the increased contact area improves cooling efficiency.

[0047] In this embodiment, the second refrigerant flow path 12 is configured as a groove-shaped portion formed on the outer peripheral surface of the stator core 3a. That is, the second refrigerant flow path 12 has a groove-shaped portion formed on the outer peripheral surface of the stator core 3a, and the groove-shaped portion is covered by the inner peripheral surface of the housing 2 (2B).

[0048] The second refrigerant flow path 12A and the second refrigerant flow path 12B are formed by grooves formed on the outer peripheral surface of the stator core 3a. These grooves are linear along the axial direction 1x and are formed continuously in a straight line from the front end (one end) to the rear end (the other end) of the stator core 3a. That is, the grooves of the second refrigerant flow path (one second refrigerant flow path) 12A and the grooves of the second refrigerant flow path (the other second refrigerant flow path) 12B are formed by continuous, straight grooves.

[0049] Furthermore, this embodiment has the following feature due to the configuration of the above-described second refrigerant flow path 12. That is, as shown in Fig. 2B, an inlet 12Ac in one second refrigerant flow path 12A that communicates with the first refrigerant flow path 11 and an inlet 12Bc in the other second refrigerant flow path 12B that communicates with the first refrigerant flow path 11 open to the outer circumferential surface of the stator core 3a so as to face radially outward.

[0050] The stator core 3a of this embodiment is formed by stacking electromagnetic steel sheets. The groove-shaped portions of the stator core 3a are formed by recesses formed on the outer periphery of the stacked electromagnetic steel sheets, and the linear groove-shaped portions along the axial direction 1x can be formed by recesses formed at the same position on the outer periphery of the electromagnetic steel sheets. That is, in this embodiment, the stator core 3a can be manufactured by pressing a large number of stacked electromagnetic steel sheets into the same shape, thereby improving manufacturing efficiency.

[0051] On the other hand, when the spiral refrigerant flow path is formed as a groove-shaped portion in the laminate of electromagnetic steel sheets, the positions of the recesses formed on the outer periphery of each electromagnetic steel sheet must be shifted circumferentially. In other words, a different press mold must be used for each of the multiple electromagnetic steel sheets that make up one stator core 3a. For this reason, it is preferable to form the spiral refrigerant flow path on the housing 2 side. If the spiral refrigerant flow path is formed as a hollow portion within the housing 2, the refrigerant will indirectly contact the stator core 3a via the housing 2, resulting in lower cooling performance compared to when the refrigerant directly contacts the stator core 3a. Alternatively, if the spiral refrigerant flow path is formed as a groove on the inner circumferential surface of the housing 2, the refrigerant will simply contact the surface of the stator core 3a, reducing the contact area between the refrigerant and the stator core 3a. Therefore, in this case, the cooling performance will be lower compared to when the refrigerant flow path is formed as a groove-shaped portion on the outer circumferential surface of the stator core 3a.

[0052] In this embodiment, the second refrigerant flow path 12A and the second refrigerant flow path 12B are formed as groove-shaped portions on the outer peripheral surface of the stator core 3a, which increases the contact area between the refrigerant and the stator core 3a and improves cooling performance.

[0053] 2B and 5, the first refrigerant flow path 11, the third refrigerant flow path 13A, and the third refrigerant flow path 13B have groove-shaped portions formed in the inner peripheral surface of the housing 2 (2B), and the groove-shaped portions formed in the inner peripheral surface of the housing 2 (2B) are covered by the outer peripheral surface of the stator core 3a. These groove-shaped portions are formed as groove-shaped portions recessed radially outward from the inner peripheral surface of the housing 2 (2B). In this case, the outer peripheral surface of the stator core 3a that covers the groove-shaped portions of the housing 2 (2B) is the portion of the outer peripheral surface of the stator core 3a where the second refrigerant flow path 12 is not formed.

[0054] In the housing 2 (2B), an inlet 12Ac of the second refrigerant flow path 12A and an inlet 12Bc of the second refrigerant flow path 12B are formed in the groove-shaped portion of the second refrigerant flow path 12 that faces the groove-shaped portion that forms the first refrigerant flow path 11. This allows the first refrigerant flow path 11 and the second refrigerant flow path 12 to communicate with each other.

[0055] An outlet 12Ad of the second refrigerant flow path 12A is formed in the groove-shaped portion of the second refrigerant flow path 12A that faces the groove-shaped portion that forms the third refrigerant flow path 13A of the housing 2 (2B), thereby connecting the third refrigerant flow path 13A and the second refrigerant flow path 12A. An outlet 12Bd of the second refrigerant flow path 12B is formed in the groove-shaped portion of the second refrigerant flow path 12B that faces the groove-shaped portion that forms the third refrigerant flow path 13B of the housing 2 (2B), thereby connecting the third refrigerant flow path 13B and the second refrigerant flow path 12A.

[0056] That is, in the rotating electric machine 1 of this embodiment, One third refrigerant flow path 13A is provided axially inside the stator core 3a with respect to one end (front end) of the stator core 3a in the axial direction 1x, The other third refrigerant flow path 13B is provided axially inside the stator core 3a with respect to the other end (rear end) of the stator core 3a in the axial direction 1x. The first refrigerant flow path 11, one third refrigerant flow path 13A and the other third refrigerant flow path 13B have groove-shaped portions formed on the inner surface of the housing 2 (2B), and the groove-shaped portions formed on the inner surface of the housing 2 (2B) are covered by the outer surface of the stator core 3a.

[0057] As shown in Figure 2B, the first housing 2A has a stepped portion 2Ad perpendicular to the axial direction 1x. The stepped portion 2Ad faces one end face of the stator core 3a and abuts against this end face. The second housing 2B has a stepped portion 2Bd perpendicular to the axial direction 1x. The stepped portion 2Bd faces the other end face of the stator core 3a and abuts against this end face.

[0058] In the groove-shaped portion that constitutes the second refrigerant flow path 12A, the end opposite to the side of the first refrigerant flow path 11 is blocked by the stepped portion 2Ad of the first housing 2A. That is, the downstream end (outlet side) of the groove-shaped portion of the second refrigerant flow path 12A is blocked by the stepped portion 2Ad of the first housing 2A abutting against one end face (front end face) of the stator core 3a.

[0059] Meanwhile, the end of the groove-shaped portion that constitutes the second refrigerant flow path 12B opposite to the first refrigerant flow path 11 is blocked by the stepped portion 2Bd of the second housing 2B. That is, the downstream (outlet) end of the groove-shaped portion of the second refrigerant flow path 12B is blocked by the stepped portion 2Bd of the second housing 2B abutting against the other end face (front end face) of the stator core 3a.

[0060] That is, in the rotating electric machine 1 of this embodiment, The housing 2 has a first housing 2A arranged on one end side of the stator core 3a in the axial direction 1x, and a second housing 2B arranged on the other end side of the stator core 3a, The first housing 2A has a stepped portion 2Ad that abuts against one end surface of the stator core 3a, The second housing 2B has a stepped portion 2Bd that abuts against the other end surface of the stator core 3a, The end (front end) of the groove-shaped portion of one second refrigerant flow path 12A opposite to the first refrigerant flow path 11 side is blocked by the stepped portion 2Ad of the first housing 2A, The other end (rear end) of the groove-shaped portion of second refrigerant flow path 12B opposite to the first refrigerant flow path 11 side is closed by a stepped portion 2Bd of second housing 2B.

[0061] When comparing the cross-sectional areas of the individual refrigerant flow path portions constituting the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13, the second refrigerant flow path 12 has the smallest cross-sectional area and the first refrigerant flow path 11 has the largest cross-sectional area. The cross-sectional area of ​​the third refrigerant flow path 13 is larger than the cross-sectional area of ​​the second refrigerant flow path 12 and smaller than the cross-sectional area of ​​the first refrigerant flow path 11.

[0062] That is, the cross-sectional areas of the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13 are as follows: The cross-sectional area of ​​one second refrigerant flow path < the cross-sectional area of ​​one third refrigerant flow path < the cross-sectional area of ​​one first refrigerant flow path have the following relationship.

[0063] The first refrigerant flow path 11 is the refrigerant flow path to which the refrigerant is first supplied, and has the largest cross-sectional area of ​​the three refrigerant flow paths to reduce pressure loss in the first refrigerant flow path. The third refrigerant flow path 13 is composed of two refrigerant flow paths 13A and 13B, and the second refrigerant flow path 12 is composed of refrigerant flow paths 12A and 12B, with each refrigerant flow path 12A and 12B consisting of multiple refrigerant flow paths. The number of refrigerant flow paths (number of branches) constituting the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13 is the largest and the smallest in the first refrigerant flow path 11, and the third refrigerant flow path 13 is fewer than the second refrigerant flow path 12 and more than the first refrigerant flow path 11. Even with the number of branches in the refrigerant flow paths, configuring the cross-sectional areas of the first refrigerant flow path 11, the second refrigerant flow path 12, and the third refrigerant flow path 13 as described above prevents the refrigerant flow from stagnating in the middle of the refrigerant flow path.

[0064] 6 to 8, modified examples of the refrigerant supply flow path 10 (10A, 10B) will be described. The communicating paths 14A, 14B need to be located above the coil end portions 7 (7A, 7B) in order to drip the refrigerant into the coil end portions 7. However, various arrangements can be adopted for the refrigerant supply flow path 10 in order to avoid interference with devices that mount the rotating electric machine 1 and to ensure a sufficient flow path cross section for the refrigerant supply flow path 10.

[0065] FIG. 6 is a schematic cross-sectional view showing an example of the rotating electrical machine 1 according to the present invention in which the refrigerant inlet passages 10 (10A, 10B) are arranged at the bottom. In the above-described embodiment, the refrigerant supply passage 10 (10A, 10B) is arranged in the upper part of the rotating electric machine 1, with the communicating passages 14A, 14B positioned above the coil end portion 7. In this example, the refrigerant supply passage 10 is arranged in the lower part of the rotating electric machine 1. The refrigerant supply passage 10 may be arranged in this manner.

[0066] FIG. 7 is a schematic cross-sectional view showing an example of a rotating electrical machine according to the present invention in which refrigerant inlet passages 10 (10A, 10B) are arranged at the top and bottom. In this example, the coolant supply passage 10 is arranged both above and below the rotating electrical machine 1. The coolant supply passage 10 may be arranged in this manner.

[0067] FIG. 8 is a schematic cross-sectional view showing an example of a rotating electrical machine according to the present invention in which the refrigerant inlet passages 10 (10A, 10B) are arranged obliquely. In this example, the coolant supply passage 10 is disposed at an intermediate position (diagonal position) between the top or bottom and the side of the rotating electrical machine 1. The coolant supply passage 10 may be disposed in this manner.

[0068] By arranging the coolant supply passage 10 as shown in FIGS. 6 to 8, or at a different position, the mountability of the rotating electrical machine 1 to other devices is improved, and the degree of freedom in design is also improved.

[0069] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0070] 1...rotating electric machine, 1x...axial direction, 2...housing, 2A...first housing, 2Aa...internal space of first housing 2A, 12Ac...inlet of second refrigerant flow path 12A, 2Ad...stepped portion of first housing 2A, 2B...second housing, 2Ba...internal space of second housing 2B, 12Bc...inlet of second refrigerant flow path 12B, 2Bd...stepped portion of second housing 2B, 3...stator, 3a...stator core, 4...rotor, 4a...rotor core, 5...rotating shaft, 7 (7A, 7B)...coil (coil end), 8...magnet, 10 (10A, 10B)...refrigerant supply flow path, 11...first refrigerant flow path, 12 (12A, 12B)...second refrigerant flow path, 13 (13A, 13B)...third refrigerant flow path, 14A, 14B...communicating passage, 15A...first refrigerant discharge flow path, 15B...second refrigerant discharge flow path.

Claims

1. a stator having a ring-shaped stator core and a coil wound around the stator core; a rotor including a rotating shaft, a rotor core to which the rotating shaft is fixed, and a magnet fixed to the rotor core, the rotor being disposed on the inner circumferential side of the stator; a refrigerant flow path through which a refrigerant for cooling the stator flows; a housing that accommodates the stator and the rotor, The refrigerant flow path is a first refrigerant flow path through which a refrigerant flows in a circumferential direction surrounding the rotary shaft; a second refrigerant flow path that communicates with the first refrigerant flow path and through which a refrigerant flows along the axial direction of the rotary shaft; a third refrigerant flow path that communicates with the second refrigerant flow path and through which a refrigerant flows in a circumferential direction surrounding the rotary shaft; a refrigerant supply flow path that supplies a refrigerant to the first refrigerant flow path first among the first refrigerant flow path, the second refrigerant flow path, and the third refrigerant flow path, the third refrigerant flow passage is provided on each of both end sides of the stator core in the axial direction, the first refrigerant flow path is provided between two of the third refrigerant flow paths provided at both end sides of the stator core in the axial direction, the second refrigerant flow path includes one second refrigerant flow path provided so that one end thereof communicates with the first refrigerant flow path and the other end thereof communicates with one of the two third refrigerant flow paths, and the other second refrigerant flow path provided so that one end thereof communicates with the first refrigerant flow path and the other end thereof communicates with the other of the two third refrigerant flow paths, the first refrigerant flow path, the second refrigerant flow path, and the third refrigerant flow path are configured so that a refrigerant supplied to the first refrigerant flow path flows from one of the second refrigerant flow paths to one of the third refrigerant flow paths, and so that a refrigerant supplied to the first refrigerant flow path flows from the other of the second refrigerant flow paths to the other of the third refrigerant flow paths, The second refrigerant flow path has a groove-shaped portion formed in an outer peripheral surface of the stator core, and the groove-shaped portion is covered by an inner peripheral surface of the housing, a plurality of the one second refrigerant flow paths and a plurality of the other second refrigerant flow paths are provided in a circumferential direction of an outer circumferential surface of the stator core, an inlet in one of the second refrigerant flow paths that communicates with the first refrigerant flow path and an inlet in the other of the second refrigerant flow paths that communicates with the first refrigerant flow path open to an outer circumferential surface of the stator core so as to face radially outward; The groove-shaped portion of the one second refrigerant flow path and the groove-shaped portion of the other second refrigerant flow path are configured as continuous linear groove-shaped portions.

2. 2. The rotating electric machine according to claim 1, the one third refrigerant flow path is provided axially inward from one end of the stator core, the other third refrigerant flow path is provided axially inward from the other end of the stator core, The first refrigerant flow path, the one third refrigerant flow path, and the other third refrigerant flow path have groove-shaped portions formed on the inner surface of the housing, and the groove-shaped portions formed on the inner surface of the housing are covered by the outer surface of the stator core, forming a rotating electric machine.

3. 3. The rotating electric machine according to claim 2, the housing includes a first housing arranged on one end side of the stator core in the axial direction, and a second housing arranged on the other end side of the stator core, the first housing has a stepped portion that abuts against one end surface of the stator core, the second housing has a stepped portion that abuts against the other end surface of the stator core, an end portion of the groove-shaped portion of one of the second refrigerant flow paths opposite to the first refrigerant flow path is blocked by the stepped portion of the first housing, an end portion of the groove-shaped portion of the other second refrigerant flow path opposite to the first refrigerant flow path is closed by the stepped portion of the second housing.

4. 3. The rotating electric machine according to claim 2, The cross-sectional areas of the first refrigerant flow path, the second refrigerant flow path, and the third refrigerant flow path are The cross-sectional area of ​​one of the second refrigerant flow paths is smaller than the cross-sectional area of ​​one of the third refrigerant flow paths and smaller than the cross-sectional area of ​​one of the first refrigerant flow paths. A rotating electric machine having the above relationship.

5. 4. The rotating electric machine according to claim 3, a first communication passage having one end communicating with the first third refrigerant flow path and the other end communicating with an internal space of the housing in which a coil end portion formed on one end face side of the stator core is disposed; a second communication passage having one end communicating with the second third refrigerant flow passage and the other end communicating with an internal space of the housing in which a coil end portion formed on the other end face side of the stator core is disposed, the one communication passage and the other communication passage are provided above an uppermost portion of the coil end portion, the first housing has a first refrigerant discharge flow path that discharges the refrigerant dripped onto the coil end portion on one end face side of the stator core to the outside of the first housing, The second housing has a second refrigerant discharge passage that discharges the refrigerant dripped onto the coil end portion on the other end face side of the stator core to the outside of the second housing.

6. 6. The rotating electric machine according to claim 5, The refrigerant supplied to the first refrigerant flow path flows in a circumferential direction while contacting an outer peripheral surface of the stator core, and is then divided into a plurality of the one second refrigerant flow paths and a plurality of the other second refrigerant flow paths, the refrigerant that has been diverted into the plurality of one of the second refrigerant flow paths merges in the one of the third refrigerant flow paths, flows upward through the one of the third refrigerant flow paths, and reaches the one of the communication paths; A rotating electric machine in which the refrigerant that has been diverted into the multiple other second refrigerant flow paths merges in the other third refrigerant flow path, flows upward through the other third refrigerant flow path, and reaches the other connecting passage.

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