Rotating electric machine stator

Abstract

To uniformly cool a stator for a rotary electric machine in a peripheral direction.SOLUTION: A stator core of a stator for a rotary electric machine includes: an appropriate C-character shaped circular flow path 31 that is extended in a circular direction, and includes a front inlet part 311 and a rear inlet part 312 that are opposite each other by being disconnected at a neighbor of a top part of the stator core; a branch flow path 34 that is provided to the neighbor of the top part of the stator core so as to be deviated in a radial direction from the circular flow path 31, and includes a front outlet part 341 and a rear outlet part 342 in which a cooling oil flows; a connection flow path 35 that connects the front outlet part 341 and the rear inlet part 312; and a connection flow path 36 that is not crossed to the connection flow path 35, and connects the rear outlet part 342 with the front inlet part 311. The front outlet part 341 and front inlet part 311 are positioned at a front side from the top part, and the rear outlet part 342 and the rear inlet part 312 are positioned to the rear side from the top part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a stator for a rotating electric machine. [Background technology]

[0002] Conventionally, there has been known a stator for a rotating electric machine that is configured so that cooling oil flows into a housing from the top of the housing arranged around the stator, and then flows from above into a ring-shaped coil end oil passage formed by a sealing member, a coil end cover, and the coil end (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-46455 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration in which the cooling medium flows from above the annular oil passage as described in Patent Document 1 above, when the stator for a rotating electric machine is tilted, for example, the flow of the cooling medium is biased to one part of the circumferential direction, making it difficult to cool the stator uniformly in the circumferential direction. [Means for solving the problem]

[0005] A stator for a rotating electric machine according to one aspect of the present invention includes a stator core having a plurality of slots provided in the circumferential direction around an axis extending in a substantially horizontal direction, and a coil arranged in the slots. The stator core has a substantially C-shaped first flow passage extending in the circumferential direction around the axis, interrupted near the top of the stator core and facing each other, with a first inlet portion at one circumferential end and a second inlet portion at the other circumferential end, a second flow passage provided near the top of the stator core and shifted radially from the first flow passage and having a first outlet portion and a second outlet portion through which the coolant flows out, a first connection flow passage connecting the first outlet portion and the first inlet portion, and a second connection flow passage connecting the second outlet portion and the second inlet portion without intersecting the first connection flow passage. The first outlet portion and the second inlet portion are located on one circumferential side of the top, and the second outlet portion and the first inlet portion are located on the other circumferential side of the top. The second flow passage is horizontally provided above the first flow passage with its top located on a reference line extending upward from the axis. do. Effect of the Invention

[0006] According to the present invention, the stator can be cooled uniformly in the circumferential direction. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing a configuration of a main part of a rotating electric machine including a stator for a rotating electric machine according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing a configuration of a top portion of a stator for a rotating electric machine according to a reference example of an embodiment of the present invention. [Diagram 3] 1 is a front view showing a configuration of a cooling flow passage around a top portion of a stator core included in a stator for a rotating electric machine according to an embodiment of the present invention; [Figure 4] Arrow IV view of Figure 3. [Figure 5A] FIG. 4 is a diagram showing the flow of cooling oil when the vehicle is running on a flat surface. [Figure 5B] FIG. 4 is a diagram showing the flow of cooling oil when the vehicle is traveling uphill. [Figure 6A] FIG. 5B is a diagram showing a modification of FIG. 5A. [Figure 6B]FIG. 5C is a diagram showing a modification of FIG. 5B. [Figure 7A] FIG. 5B is a diagram showing another modified example of FIG. 5A. [Figure 7B] FIG. 5C is a diagram showing another modified example of FIG. 5B. [Figure 8] 13 is a diagram showing another configuration of a cooling passage provided in a stator. FIG. [Figure 9] FIG. 5 is a diagram showing a modification of FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 9. Fig. 1 is a cross-sectional view showing a configuration of a main part of a rotating electric machine 100 including a stator for a rotating electric machine according to an embodiment of the present invention. The rotating electric machine 100 is mounted on a hybrid vehicle or an electric vehicle and can be used as an electric motor for driving the vehicle, and can also be used as a generator. The rotating electric machine 100 can also be mounted on something other than a vehicle and used for various purposes. Fig. 1 also shows the front-rear direction, left-right direction, and up-down direction of the vehicle when the rotating electric machine 100 is mounted on the vehicle. The downward direction is the direction in which gravity acts.

[0009] FIG. 1 is a front view showing a main configuration of a rotating electric machine 100, as viewed from the left. As shown in FIG. 1, the rotating electric machine 100 includes a rotor 1 that rotates about an axis line CL0 extending in the left-right direction, and a stator 2 that is provided outside the rotor 1 so as to surround an outer circumferential surface 1a of the rotor 1. In the following, the direction in which the axis line CL0 extends is defined as the axial direction, the direction extending radially from the axis line CL0 as the radial direction, and the direction along the circumference of a circle centered on the axis line CL0 as the circumferential direction. FIG. 1 shows a reference line L1 that extends upward from the axis line CL0. The top (top) of the stator 2 is on the reference line L1.

[0010] The rotating electric machine 100 is configured as, for example, an embedded magnet type synchronous motor. Thus, the rotor 1 has a rotor core 10 having a substantially annular shape centered on an axis CL0, and a plurality of magnetic pole portions (not shown) formed in the rotor core 10 in the circumferential direction. Permanent magnets are embedded in the magnetic pole portions. For example, a rotor shaft (not shown) constituting the output shaft of the rotating electric machine 100 is fitted into an inner peripheral surface 10a of the rotor core 10, and the rotor 1 rotates integrally with the rotor shaft. The outer peripheral surface 1a of the rotor 1 corresponds to the outer peripheral surface of the rotor core 10. The rotor core 10 is formed by stacking a plurality of (for example, several tens of) magnetic metal magnetic steel plates in the axial direction.

[0011] The stator 2 has a substantially annular stator core 20 centered on an axis CL0, with an inner circumferential surface 2a disposed at a predetermined distance in the radial direction from the outer circumferential surface 1a of the rotor 1, and a coil 21 attached to the stator core 20. The stator core 20 is formed by stacking multiple electromagnetic steel plates made of a magnetic metal in the axial direction.

[0012] The stator core 20 has a plurality of circumferential teeth 23 that protrude radially inward from a substantially cylindrical yoke 24 at equal circumferential intervals. A plurality of circumferential slots 22 are provided between circumferentially adjacent teeth 23 from the inner circumferential surface 2a toward the radially outward side, and a coil 21 is attached to each slot 22. The slots 22 are provided all around the inner circumferential surface 2a, but for convenience, only the slots 22 near the top are shown in FIG. 1. The total number of slots 22 is, for example, 48. The total number of slots 22 may be more or less than 48.

[0013] The coil 21 is a conductor having a substantially rectangular cross section. The coil 21 may be a conductor having a circular cross section. The coil 21 includes a U-phase coil, a V-phase coil, and a W-phase coil, and is configured as a three-phase coil. When the rotating electric machine 100 is used as an electric motor, three-phase AC power is supplied to each coil 21 from a power conversion device (not shown). This generates a magnetic field in the stator 2, and the rotor 1 rotates due to the interaction between this magnetic field and the magnetic field generated by the permanent magnets of the magnetic poles of the rotor 1. As a result, a driving force is generated and the vehicle runs. When the rotating electric machine 100 is used as a generator, the three-phase AC power generated by driving the rotating electric machine 100 is supplied to a power conversion device or the like.

[0014] A flow passage (cooling flow passage) through which a cooling medium flows is formed inside the stator core 20. The cooling medium is, for example, cooling oil. The cooling flow passage has, in the yoke 24 of the stator core 20, a circumferential flow passage 31 that extends in the circumferential direction along a reference circle C1 centered on the axis CL0, and a plurality of circumferential axial flow passages 32 that extend in the axial direction perpendicular to the reference circle C1. The axial flow passages 32 are provided around the entire circumference of the stator core 20 along the reference circle C1, but only some of the axial flow passages 32 are shown in FIG. 1. The circumferential flow passage 31 is provided in the axial center of the stator core 20.

[0015] The axial passage 32 is disposed radially outside the slots 22 and between the slots 22 adjacent in the circumferential direction. The axial passage 32 penetrates the stator core 20 in the axial direction and communicates with the circumferential passage 31 at the axial center. The cross-sectional shape of the circumferential passage 31 is, for example, circular or approximately circular, and the cross-sectional shape of the axial passage 32 is also circular or approximately circular. The rectangular cross-sectional shapes of the passages 31, 32 may be other than circular. The passages 31, 32 can be formed by stacking electromagnetic steel sheets having cutouts corresponding to the passage shapes.

[0016] The stator core 20 has a plurality of circumferential flange portions 25 that protrude radially outward from the outer circumferential surface of the stator core 20. Specifically, the flange portions 25 are provided at 90° intervals starting from the apex (reference line L1). Although not shown in the drawings, the flange portions 25 are provided with through holes through which bolts are inserted, and the stator 2 is fixed to a case, a frame, or the like by the bolts inserted into the through holes.

[0017] The rotating electric machine stator 2 according to this embodiment is characterized by the configuration of the cooling passages, particularly the configuration of the cooling passages around the top of the stator core 20. In this regard, a reference example of this embodiment will be described first. Fig. 2 is a perspective view (viewed from diagonally above left) showing the configuration around the top of a rotating electric machine stator 2A according to a reference example of this embodiment. As shown in Fig. 2, the circumferential passage 31A of the stator 2A is provided around the entire circumference centered on the axis line CL0 (Fig. 1).

[0018] A through hole (axial flow passage 32) is opened in the stator core 20 from one axial end face (left end face 20a) to the other axial end face (right end face 20b) so as to communicate with the circumferential flow passage 31A. An inlet flow passage 33 is provided in the flange portion 25 at the top of the stator core 20 from the left end face 20a to the axial center of the stator core 20. The inlet flow passage 33 bends radially inward at the axial center of the stator core 20 and communicates with the circumferential flow passage 31A.

[0019] Cooling oil is supplied to the inlet passage 33 from outside the stator 2A through an opening 33a at the left end. The supplied cooling oil is guided to a plurality of axial passages 32 in the circumferential direction through the inlet passage 33 and the circumferential passage 31A. The cooling oil guided to the axial passages 32 flows in the left-right direction along the axial passages 32 and flows out from the openings on the left end face 20a and the right end face 20b of the stator core 20. This allows the stator core 20 to be cooled.

[0020] However, with such a cooling flow passage configuration, when the vehicle travels on a slope and the stator 2A tilts in the front-rear direction, the flow of cooling oil in the circumferential flow passage 31A may be biased to the front or rear due to gravity. That is, when traveling downhill, the cooling oil supplied to the circumferential flow passage 31A is biased to the front, and when traveling uphill, the cooling oil is biased to the rear. As a result, the cooling oil may not flow uniformly in the circumferential direction, and the temperature variation in the circumferential direction of the stator 2 may become large. Therefore, in this embodiment, the stator 2 for a rotating electric machine is configured as follows so as to suppress the variation in the temperature distribution in the circumferential direction of the stator 2 even when the stator 2 tilts in the front-rear direction.

[0021] Fig. 3 is a front view (viewed from the left) showing the configuration of the cooling flow passage around the top of stator core 20, and Fig. 4 is a view taken along line IV of Fig. 3 (viewed from above). In Fig. 3 and Fig. 4, the cooling flow passage inside stator core 20 is shown by solid lines for the sake of convenience. As shown in Fig. 3 and Fig. 4, circumferential flow passage 31 is not provided around the entire circumference of stator core 20, but is interrupted near flange portion 25 at the top.

[0022] More specifically, the circumferential flow passage 31 does not reach the reference line L1, and has one end (front inlet portion 311) and the other end (rear inlet portion 312) on both the front and rear sides of the reference line L1. Therefore, the circumferential flow passage 31 is configured in a substantially C-shape centered on the axis line CL0 ( FIG. 1 ) from the front inlet portion 311 to the rear inlet portion 312. Among the multiple axial flow passages 32 extending in the left-right direction, the front inlet portion 311 and the rear inlet portion 312 are intersected by the uppermost axial flow passage 32. The uppermost axial flow passage 32 may intersect with the circumferential flow passage 31 at a position shifted from the front inlet portion 311 and the rear inlet portion 312 (for example, in front of the front inlet portion 311 and behind the rear inlet portion 312).

[0023] The inlet flow passage 33 extends rightward from an opening 33a on the left end face of the stator core 20 on the radially outer side of the reference circle C1 and on the reference line L1, and then extends downward at the axial center of the stator core 20. A branch flow passage 34 that branches off the inlet flow passage 33 into two is connected to the lower end of the inlet flow passage 33. The branch flow passage 34 is provided on a horizontal plane SF1 that extends in the front-rear and left-right directions above the reference circle C1 and below the inlet flow passage 33. More specifically, the branch flow passage 34 extends in a substantially straight line along the horizontal plane SF1 from one end (front outlet portion 341) on the front and left side to the other end (rear outlet portion 342) on the rear and right side, and intersects with the lower end of the inlet flow passage 33 at the center of the branch flow passage 34.

[0024] The front outlet portion 341 of the branch flow path 34 and the rear inlet portion 312 of the circumferential flow path 31 are connected to one end and the other end of the connection flow path 35, which extends obliquely in a substantially straight line from the front outlet portion 341 of the branch flow path 34 to the rear, right, and downward, respectively. The rear outlet portion 342 of the branch flow path 34 and the front inlet portion 311 of the circumferential flow path 31 are connected to one end and the other end of the connection flow path 36, which extends obliquely in a substantially straight line from the rear outlet portion 342 of the branch flow path 34 to the front, left, and downward, respectively. The connection flow path 35 and the connection flow path 36 do not intersect with each other, but are in a twisted position relationship. As a result, the inlet flow path 33 communicates with the rear inlet portion 312 of the circumferential flow path 31 via the branch flow path 34 and the connection flow path 35, and communicates with the front inlet portion 311 of the circumferential flow path 31 via the branch flow path 34 and the connection flow path 36.

[0025] An insulating member 40 having a generally rectangular frame-like cross section is disposed in the slot 22. A generally rectangular parallelepiped accommodation space is formed inside the insulating member 40, and four conductor segments 210 forming the coil 21 are disposed in a row in the radial direction in the accommodation space. The number of conductor segments 210 in the slot may be more or less than four. The conductor segments 210 are covered with an insulating coating.

[0026] A main operation of the stator 2 for a rotating electric machine configured as described above will be described. When the vehicle is traveling on a flat surface, as shown in FIG. 5A, the branch passage 34 is horizontal. In this case, the cooling oil supplied from the outside of the stator core 20 to the inlet passage 33 flows obliquely downward from the front to the rear of the reference line L1 through the branch passage 34 and the connecting passage 35 as shown by arrows A1, A2, and A3 in FIG. 5A, and flows into the circumferential passage 31 through the rear inlet portion 312. Also, as shown by arrows A1, A4, and A5, the cooling oil flows obliquely downward from the rear to the front of the reference line L1 through the branch passage 34 and the connecting passage 35, and flows into the circumferential passage 31 through the front inlet portion 311.

[0027] At this time, because the branch passage 34 is horizontal, the cooling oil flows evenly into the connecting passages 35, 36 from the front outlet portion 341 and the rear outlet portion 342 of the branch passage 34. Therefore, the amount of cooling oil flowing through the circumferential passage 31 via the rear inlet portion 312 and the amount of cooling oil flowing through the circumferential passage 31 via the front inlet portion 311 are equal to each other, and the cooling oil flows evenly in the circumferential direction along the circumferential passage 31. As a result, the cooling oil flows evenly from the circumferential passage 31 into the multiple axial passages 32 in the circumferential direction, and the stator 2 can be cooled evenly in the circumferential direction.

[0028] When the vehicle is traveling uphill, the stator 2 is tilted in the front-rear direction. Therefore, as shown in Fig. 5B, the branch passage 34 is tilted, and the front outlet portion 341 of the branch passage 34 is located higher than the rear outlet portion 342. As a result, due to the action of gravity, a larger flow rate flows into the rear outlet portion 342 at the lower end of the branch passage 34 than into the front outlet portion 341 at the upper end. As a result, the pressure of the cooling oil (arrow A4) flowing through the connection passage 36 becomes higher than the pressure of the cooling oil (arrow A2) flowing through the connection passage 35, and the amount of cooling oil flowing into the circumferential passage 31 at an upward gradient becomes greater than the amount of cooling oil flowing downhill.

[0029] On the other hand, since the cooling oil that flows into the circumferential flow passage 31 through the front inlet portion 311 flows in the circumferential flow passage at an upward gradient, the pressure of this cooling oil (arrow A5) is lower than the pressure of the cooling oil that flows in through the rear inlet portion 312 (arrow A3). As a result, the amount of cooling oil that flows in the circumferential flow passage 31 at an upward gradient through the connecting flow passage 36 is substantially equal to the amount of cooling oil that flows in the circumferential flow passage 31 at a downward gradient through the connecting flow passage 35. This allows the cooling oil to flow uniformly through the multiple axial flow passages 32 in the circumferential direction, and the stator 2 to be uniformly cooled in the circumferential direction, even if the vehicle is tilted.

[0030] Fig. 6A is a diagram showing a modified example of Fig. 5A. Fig. 6A differs from Fig. 5A in the configuration of the connecting passages 35, 36. That is, in Fig. 5A, the cross-sectional areas of the connecting passages 35, 36 are equal to each other, but in Fig. 6A, the cross-sectional area S1 of the connecting passage 36 is larger than the cross-sectional area S2 of the connecting passage 35. This makes the pressure loss of the connecting passage 36 smaller than the pressure loss of the connecting passage 35. As a result, as shown in Fig. 6B, when the vehicle travels uphill, more cooling oil flows through the connecting passage 36 (arrow A4) than in Fig. 5B, and a sufficient amount of cooling oil (arrow A5) flows through the circumferential passage 31 in front of the reference line L1.

[0031] In particular, when the vehicle is traveling uphill, the driving torque of the vehicle is large, and the amount of heat generated by the coil 21 increases. For this reason, it is necessary to supply more cooling oil to the circumferential flow passage 31 with an upward gradient in front of the reference line L1. In this regard, the amount of cooling oil supplied to the circumferential flow passage 31 with an upward gradient can be easily increased by increasing the cross-sectional area of ​​the connecting flow passage 36. Note that, when the cross-sectional area of ​​the connecting flow passage 36 is increased, the amount of cooling oil flowing in front of the reference line L1 (arrow A5) becomes greater than the amount of cooling oil flowing behind the reference line L1 (arrow A3) when the vehicle is traveling on a flat surface, as shown in FIG. 6A. However, in this case, the driving torque is small, and the amount of heat generated by the coil 21 is small, so there is no problem even if the amount of cooling oil differs before and after the reference line L1.

[0032] FIG. 7A is a diagram showing a further modified example of FIG. 5A. FIG. 7A is different from FIG. 5A in the configuration of the connection flow passages 35, 36. That is, in FIG. 5A, the angle (θ1 in FIG. 7A) of the connection flow passage 35 with respect to the vertical line and the angle (θ2 in FIG. 7A) of the connection flow passage 36 with respect to the vertical line are equal to each other, but in FIG. 7A, θ1 is larger than θ2. In other words, the angle between the branch flow passage 34 and the connection flow passage 35 is smaller than the angle between the branch flow passage 34 and the connection flow passage 36. As a result, the pressure loss of the cooling oil flowing from the branch flow passage 34 to the connection flow passage 35 is larger than the pressure loss of the cooling oil flowing from the branch flow passage 34 to the connection flow passage 36, and more cooling oil flows through the connection flow passage 36 than through the connection flow passage 35.

[0033] As a result, as shown in Fig. 7B, when the vehicle is traveling uphill, more cooling oil flows through the connecting passage 36 (arrow A4) than in Fig. 5B, and a sufficient amount of cooling oil (arrow A5) flows through the circumferential passage 31 in front of the reference line L1. Also, since there is no need to increase the cross-sectional area S2 of the connecting passage 35 as in the example of Fig. 6A, a magnetic flux can be formed satisfactorily in the stator core 20, and a decrease in the rotational torque of the rotor can be suppressed.

[0034] The cooling oil flowing through the circumferential flow passage 31 may be guided to the slots 22 (FIG. 3). FIG. 8 is a diagram showing one example of this. FIG. 8 shows the configuration of the cooling flow passage behind the reference line L1, and illustrates the attitude of the stator 2 when traveling uphill, for example. As shown in FIG. 8, between the circumferential flow passage 31 and the slots 22 of the stator core 20, slot flow passages 37, 38 that connect the radial outer ends of the slots 22 and the circumferential flow passage 31 are provided alternately in the circumferential direction.

[0035] More specifically, the slot flow passage 37 extends in a substantially linear manner from a radial outer end (slot opening 22a) of the slot 22 to a communication port 313 provided in the circumferential flow passage 31. Moreover, the slot flow passage 38 extends in a substantially linear manner from a radial outer end (slot opening 22b) of the same slot 22 to a communication port 314 provided in the circumferential flow passage 31 below the communication port 313. The slot flow passages 37, 38 are provided from the top of the stator core 20 as the starting point (0°) to the rear over a predetermined range (e.g., 90° or 180°) centered on the axis CL1.

[0036] If a pair of slots 22 adjacent in the circumferential direction is defined as a first slot 22A and a second slot 22B below the first slot 22A, the communication port 314 of the slot flow passage 38 connected to the first slot 22A is located below the communication port 313 of the slot flow passage 37 connected to the second slot 22B. The axial positions of the slot openings 22a and 22b are shifted from each other. Alternatively, the axial positions of the communication ports 313 and 314 are shifted from each other. Therefore, the slot flow passage 38 connected to the first slot 22A and the slot flow passage 37 connected to the second slot 22B are in a twisted relationship without intersecting each other.

[0037] When the vehicle travels uphill, cooling oil flows into each slot 22 through the slot passage 37 (arrow A6) and through the slot passage 38 (arrow A7). At this time, the flow direction of the cooling oil in the slot passage 37 (arrow A6) is closer to the direction of gravity than the flow direction of the cooling oil in the slot passage 38 (arrow A7), so that the cooling oil easily flows through the slot passage 37. On the other hand, when focusing on a certain slot 22 (for example, the first slot 22A), not only is the cooling oil supplied to the first slot 22A from the slot passage 37 through the communication port 313, but the cooling oil is also supplied from the slot passage 38 through the communication port 314 located below the communication port 313. That is, the cooling oil is supplied from the slot passages 37 and 38 having two different inclination angles. As a result, when the stator 2 is inclined and the cooling oil from one slot passage decreases, the cooling oil from the other slot passage can compensate for the decrease, and the cooling oil can be uniformly guided to the multiple slots 22.

[0038] According to this embodiment, the following advantageous effects can be obtained. (1) A stator 2 for a rotating electric machine includes a stator core 20 in which a plurality of slots 22 are provided in the circumferential direction around an axis CL extending in a substantially horizontal direction, and coils 21 arranged in the slots 22 (FIG. 1). The stator core 20 extends in the circumferential direction around the axis CL0, has a substantially C-shaped circumferential flow passage 31 that is interrupted near the top of the stator core 20 and has a front inlet portion 311 at one circumferential end and a rear inlet portion 312 at the other circumferential end that face each other, a branch flow passage 34 that is provided near the top of the stator core 20 and is shifted radially from the circumferential flow passage 31 and has a front outlet portion 341 and a rear outlet portion 342 from which cooling oil flows out, a connection flow passage 35 that connects the front outlet portion 341 and the rear inlet portion 312, and a connection flow passage 36 that connects the rear outlet portion 342 and the front inlet portion 311 without intersecting the connection flow passage 35 (FIGS. 3 and 4). The front outlet portion 341 and the front inlet portion 311 are located forward of the top (reference line L1), and the rear outlet portion 342 and the rear inlet portion 312 are located rearward of the top (FIG. 3).

[0039] With this configuration, the pair of connecting passages 35, 36 extending in the front-rear direction beyond the reference line L1 are in a twisted position relationship. Therefore, when the stator 2 is tilted so that one side of the front-rear direction of the stator 2 (for example, the front) has an upward gradient with respect to the other side of the front-rear direction (the rear), the amount of cooling oil flowing into the connecting passage 36 via the rear outlet portion 342 is greater than the amount of cooling oil flowing into the connecting passage 35 via the front outlet portion 341. As a result, a large amount of cooling oil flows into the circumferential passage 31 with an upward gradient via the front inlet portion 311, and the stator 2 can be uniformly cooled in the circumferential direction even when the stator 2 is tilted.

[0040] (2) The branch flow passage 34 is disposed radially outward of the circumferential flow passage 31 ( FIG. 3 ). The connecting flow passages 35, 36 each extend in a substantially straight line ( FIG. 3 , FIG. 4 ). This allows cooling oil to be evenly supplied to the circumferential flow passage 31 from the front inlet portion 311 and the rear inlet portion 312 of the circumferential flow passage 31 when the vehicle is traveling on a flat surface. In addition, because the branch flow passage 34 is disposed radially outward of the circumferential flow passage 31, cooling oil can be easily supplied to the branch flow passage 34 from outside the stator 2.

[0041] (3) The stator 2 for a rotating electric machine is mounted on a vehicle so as to generate a driving force for running. One circumferential side of the top is the front of the vehicle, and the other circumferential side of the top is the rear of the vehicle. In this configuration, when the vehicle runs uphill and the amount of heat generated by the coil 21 increases, it is necessary to supply more cooling oil to the circumferential flow passage 31 on the front side of the reference line L1. In this regard, since the connecting flow passages 35, 36 are in a twisted positional relationship, a sufficient amount of cooling oil can be supplied to the front circumferential flow passage 31 via the front inlet portion 311 when the vehicle runs uphill.

[0042] (4) The cross-sectional area S1 of the connecting passage 36 can be made larger than the cross-sectional area S2 of the connecting passage 35 (FIGS. 6A and 6B). This reduces the pressure loss in the connecting passage 36, and allows a large amount of cooling oil to be supplied to the front circumferential passage 31 via the connecting passage 36.

[0043] (5) The branch passage 34 extends in a substantially straight line from the front outlet portion 341 to the rear outlet portion 342 (FIG. 3). In this case, the angle θ1 between the connecting passage 35 and a perpendicular line to the branch passage 34 at the front outlet portion 341 can be made larger than the angle between the connecting passage 36 and a perpendicular line to the branch passage 34 at the rear outlet portion 342 (FIGS. 7A and 7B). In this case as well, the pressure loss in the connecting passage 36 is reduced, and a large amount of cooling oil can be supplied to the front circumferential passage 31 via the connecting passage 36.

[0044] (6) The multiple slots 22 include a first slot 22A and a second slot 22B provided below the first slot 22A (FIG. 8). The stator core 20 may further include a slot flow passage 38 (first slot connecting flow passage) connecting a communication port 314 (first outlet port) provided in the circumferential flow passage 31 to the first slot 22A, and a slot flow passage 37 (second slot connecting flow passage) connecting a communication port 313 (second outlet port) provided in the circumferential flow passage 31 above the communication port 314 to the second slot 22B (FIG. 8). This allows the cooling oil to be uniformly supplied to the multiple slots 22 in the circumferential direction even when the stator 2 is tilted.

[0045] This embodiment can be modified in various ways. Some modified examples will be described below. In the above embodiment, the approximately tubular branch flow path 34 is disposed as the second flow path on the radially outer side of the approximately C-shaped circumferential flow path 31 (first flow path) having the front inlet portion 311 (second inlet portion) and the rear inlet portion 312 (first inlet portion), but the configuration of the second flow path is not limited to this. For example, as shown in FIG. 9, the branch flow path 34 (second flow path) may be configured as an approximately rectangular chamber space extending in the horizontal direction. In FIG. 9, the inlet flow path 33 is connected to the center of the branch flow path 34, and the rear outlet portion 342 of the connection flow path 36 is connected to the right rear end portion of the branch flow path 34, and the front outlet portion 341 of the connection flow path 36 is connected to the left front end portion of the branch flow path 34. The inlet flow path 33 may be connected to the left end face of the branch flow path 34, which allows the inlet flow path 33 to be shortened.

[0046] In the above embodiment (FIG. 3), the front outlet portion 341 (first outlet portion) of the branch flow passage 34 and the rear inlet portion 312 of the circumferential flow passage 31 are connected via a substantially straight connection flow passage 35 (first connection flow passage), and the rear outlet portion 342 (second outlet portion) of the branch flow passage 34 and the front inlet portion 311 of the circumferential flow passage 31 are connected via a substantially straight connection flow passage 36 (second connection flow passage). However, the configurations of the first connection flow passage and the second connection flow passage are not limited to those described above as long as they extend beyond the top of the stator core 20 and are in a twisted relationship with each other.

[0047] In the above embodiment, the circumferential flow passage 31 is provided along a vertical plane extending in the front-rear direction and the up-down direction, but the vertical plane on which the first flow passage is provided may extend in a direction other than the front-rear direction. In the above embodiment, cooling oil is supplied to the cooling flow passage, but the cooling medium is not limited to cooling oil. In the above embodiment, the rotor 1 is disposed radially inside the stator 2, but the rotor may be disposed radially outside the stator. In the above embodiment, the stator for a rotating electric machine is applied to a vehicle, but the stator for a rotating electric machine of the present invention may also be applied to things other than vehicles.

[0048] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. The above-mentioned embodiment and one or more modifications can be arbitrarily combined, and modifications can be combined with each other. [Explanation of symbols]

[0049] 2 stator, 20 stator core, 21 coil, 22 slot, 22A first slot, 22B second slot, 31 circumferential flow passage, 34 branch flow passage, 35, 36 connecting flow passage, 37, 38 slot flow passage, 311 front inlet portion, 312 rear inlet portion, 313, 314 communication port, 341 front outlet portion, 342 rear outlet portion, L1 reference line

Claims

1. a stator core having a plurality of slots provided in a circumferential direction around an axis extending in a substantially horizontal direction; A stator for a rotating electric machine comprising: The stator core is a first flow passage having a substantially C-shape, the first flow passage extending in a circumferential direction about the axis and terminated near a top of the stator core, the first flow passage having a first inlet portion at one end in the circumferential direction and a second inlet portion at the other end in the circumferential direction through which a cooling medium flows; a second flow passage provided in the vicinity of the top of the stator core and radially shifted from the first flow passage, the second flow passage having a first outlet portion and a second outlet portion through which the cooling medium flows out; a first connection flow path connecting the first outlet portion and the first inlet portion; a second connection flow path that connects the second outlet portion and the second inlet portion without intersecting the first connection flow path, the first outlet portion and the second inlet portion are located on one circumferential side of the apex, and the second outlet portion and the first inlet portion are located on the other circumferential side of the apex, A stator for a rotating electric machine, characterized in that the second flow passage is horizontally provided above the first flow passage with the top portion positioned on a reference line extending upward from the axis.

2. 2. The stator for a rotating electric machine according to claim 1, The second flow passage is disposed radially outward of the first flow passage, The first connection flow path extends substantially linearly from the first outlet portion to the first inlet portion, The second connection passage extends in a substantially straight line from the second outlet portion to the second inlet portion.

3. 2. The stator for a rotating electric machine according to claim 1, the stator for the rotating electric machine is mounted on a vehicle so as to generate a driving force for running the vehicle, a stator for a rotating electric machine, wherein the one circumferential side of the apex is a front side of a vehicle, and the other circumferential side of the apex is a rear side of the vehicle.

4. 4. The stator for a rotating electric machine according to claim 3, A stator for a rotating electric machine, wherein a cross-sectional area of ​​the second connection passage is larger than a cross-sectional area of ​​the first connection passage.

5. 5. The stator for a rotating electric machine according to claim 3, The second flow path extends substantially linearly, a first outlet portion having a first connecting passage and a perpendicular line to the second flow passage at the first outlet portion, the first connecting passage being larger than a second outlet portion having a first connecting passage and a perpendicular line to the second flow passage at the second outlet portion.

6. 2. The stator for a rotating electric machine according to claim 1, The plurality of slots includes a first slot and a second slot provided below the first slot, The stator core is a first slot connection flow passage that connects a first outlet of the cooling medium provided in the first flow passage and the first slot; a second slot connecting flow passage that connects a second outlet for the cooling medium provided in the first flow passage above the first outlet and the second slot.

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