WO2019159522A1 - Cooling structure for rotary electric machine - Google Patents

Abstract

This cooling structure for a rotary electric machine is provided with a jacket part having, on the inside, a flow channel through which a refrigerant for cooling a stator core flows, wherein the cooling structure is configured such that the refrigerant flows in the flow channel in a central axial line direction from a second coil end side toward a first coil end part side.

Description

Cooling structure of rotating electric machine

The present invention relates to a cooling structure for a rotating electric machine.

Conventionally, a cooling structure for a rotating electric machine is known. Such a cooling structure for a rotating electric machine is disclosed in, for example, US Patent Application Publication No. 2015/0130302.

US Patent Application Publication No. 2015/0130302 discloses a cooling jacket for an in-vehicle motor. Specifically, the cooling jacket includes a cylindrical housing and a cylindrical case that covers the outer periphery of the housing. The cylindrical housing is configured to surround the outer periphery of the motor. A plurality of fins are provided on the outer peripheral surface of the cylindrical housing so as to extend along the circumferential direction. Moreover, the cylindrical case is provided so that the outer periphery of a cylindrical housing may be covered. A flow path through which the refrigerant flows is constituted by a space surrounded by the cylindrical case and the cylindrical housing.

Also, in US Patent Application Publication No. 2015/0130302, a refrigerant inlet and outlet are provided on one side in the central axis direction of the cooling jacket. The refrigerant flowing in from the inflow port flows toward the other side in the central axis direction, and then flows along the circumferential direction between a plurality of fins provided so as to extend along the circumferential direction. Thereafter, the refrigerant changes its flowing direction from the circumferential direction toward one side in the central axis direction, and then flows out from the outlet.

On the other hand, although not described in US Patent Application Publication No. 2015/0130302, conventionally, a coil is arranged on a stator core of a motor. Further, the coil end portions of the coils protrude from the end surface on one side and the end surface on the other side in the central axis direction of the stator core, respectively. Due to the difference in volume between the coil end portion protruding from one side in the central axis direction of the stator core and the coil end portion protruding from the other side, one side in the central axis direction of the motor (stator core) The temperature difference from the other side may be relatively large. Specifically, the heat generation amount from the coil end portion having a large volume is larger than the heat generation amount from the coil end portion having a small volume.

US Patent Application Publication No. 2015/0130302

Here, in the conventional motor as described above, the heat generation amount from the coil end portion having a large volume is larger than the heat generation amount from the coil end portion having a small volume, in US Patent Application Publication No. 2015/0130302. By providing the described cooling jacket, it is possible to dissipate heat generated from the coil end portion by the refrigerant flowing along the circumferential direction. Specifically, the heat generated from the coil end portion is radiated from the cooling jacket (refrigerant) through the stator core. However, in the cooling jacket described in US Patent Application Publication No. 2015/0130302, since the refrigerant flows along the circumferential direction, the coil end portion side having a large volume (heat generation amount) also has a small volume (heat generation amount). It is considered that the coil end side is also cooled in the same manner. As a result, it is considered that the entire motor (stator core) can be reduced by a substantially constant temperature, while the temperature difference between one side and the other side in the central axis direction of the motor (rotating electrical machine) cannot be resolved. There is a problem.

The present invention has been made to solve the above-described problems, and one object of the present invention is when the volume of the coil end portion is different between one side and the other side in the central axis direction of the stator core. Another object is to provide a cooling structure for a rotating electrical machine capable of reducing a temperature difference between one side and the other side in the central axis direction of the rotating electrical machine.

In order to achieve the above object, a cooling structure for a rotating electrical machine according to one aspect of the present invention is a cooling structure for a rotating electrical machine including a rotor core and a stator core provided to face the rotor core and in which a coil is disposed. And a jacket portion provided so as to cover the outer peripheral surface of the stator core and provided therein with a flow path through which a refrigerant for cooling the stator core flows. The coil protrudes from an end surface on one side in the central axis direction of the stator core. A first coil end portion and a second coil end portion protruding from the other end surface of the stator core in the central axis direction and having a volume larger than the volume of the first coil end portion. In the central axis direction, the flow path is configured to flow from the second coil end portion side toward the first coil end portion side.

In the cooling structure for a rotating electrical machine according to one aspect of the present invention, as described above, the refrigerant moves from the second coil end portion side having a large volume toward the first coil end portion side having a small volume in the central axis direction. Are configured to flow through the flow path. Accordingly, the refrigerant flows from the second coil end portion side having a large volume (relatively high temperature) in a state where the refrigerant temperature is relatively low. As a result, the second coil end portion side having a relatively high temperature is efficiently cooled, so that the temperature on the second coil end portion side can be relatively reduced. As a result, the degree of temperature decrease on the second coil end portion side is greater than the degree of temperature decrease on the first coil end portion side. As a result, the temperature on the second coil end portion side can be made closer to the temperature on the first coil end portion side. Therefore, even when the volume of the coil end portion is different on one side and the other side in the central axis direction of the stator core. The temperature difference between the one side and the other side in the central axis direction of the rotating electrical machine can be reduced.

According to the present invention, as described above, even when the volume of the coil end portion is different between the one side and the other side in the central axis direction of the stator core, the temperature at the one side and the other side in the central axis direction of the rotating electric machine is different. The difference can be reduced.

It is sectional drawing of the rotary electric machine and cooling structure by 1st Embodiment. It is a perspective view which shows the flow path of the cooling structure by 1st Embodiment. It is a figure for demonstrating the temperature distribution of the rotary electric machine by a comparative example. It is sectional drawing of the rotary electric machine and cooling structure by 2nd Embodiment. It is a figure (development drawing) which shows the flow path of the cooling structure by the modification of 1st and 2nd embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
(Structure of rotating electrical machine)
With reference to FIG. 1, the structure of the rotary electric machine 1 by 1st Embodiment is demonstrated.

As shown in FIG. 1, in the present specification, the “center axis direction” means a direction along the rotation axis (reference numeral O) of the stator core 21 (rotor core 11). The “circumferential direction” means the circumferential direction (A direction) of the stator core 21. Further, “inner side in the radial direction” and “inner side” mean the direction toward the center of the stator core 21 (the direction of the arrow B1). Further, “outside in the radial direction” and “outside of the outer diameter” mean a direction toward the outside of the stator core 21 (arrow B2 direction).

The rotating electrical machine 1 includes a rotor 10 and a stator 20.

The rotor 10 includes an annular rotor core 11. The rotor core 11 is formed by laminating a plurality of electromagnetic steel plates. A plurality of permanent magnets 12 are embedded in the rotor core 11. The rotor core 11 is rotated by a force generated by a magnetic field from the permanent magnet 12 and a current flowing in a coil 30 described later.

Further, a shaft 13 is provided along the central axis of the rotor core 11. Bearings 14 are respectively provided on one side and the other side of the shaft 13 in the central axis direction.

The stator 20 includes an annular stator core 21. For example, the stator 20 constitutes a part of the inner rotor type rotating electrical machine 1, and the stator core 21 is disposed so as to face the rotor core 11 in the radial direction.

The stator core 21 is formed by laminating a plurality of electromagnetic steel plates. The stator core 21 is formed with a plurality of teeth (not shown) and slots (not shown) provided between adjacent teeth. A coil 30 is disposed in the slot of the stator core 21.

The coil 30 is formed, for example, by winding a rectangular conductor wire a plurality of times.
The coil 30 includes a first coil end portion 31 that is a portion projecting from an end surface 21 a on one side (X1 direction side) of the stator core 21 in the central axis direction, and the other side (X2 direction side) of the stator core 21 in the central axis direction. 2nd coil end part 32 which is a part projected from end face 21b. The volume of the second coil end portion 32 is configured to be larger than the volume of the first coil end portion 31.

Specifically, in the first embodiment, the protruding length L2 of the second coil end portion 32 from the end surface 21b in the central axis direction of the stator core 21 is the end surface in the central axis direction of the stator core 21 of the first coil end portion 31. It is larger than the protruding length L1 from 21a. Thereby, the volume of the second coil end portion 32 is larger than the volume of the first coil end portion 31. Further, the first coil end portion 31 (second coil end portion 32) is disposed in an annular shape on the end surface 21a (end surface 21b) of the stator core 21.

In the first embodiment, the second coil end portion 32 is configured such that at least one of the power line 41 that supplies power to the coil 30 and the neutral line 42 connected to the neutral point is connected. Has been. Specifically, both the power line 41 and the neutral line 42 are connected to the second coil end portion 32. Thus, since the power line 41 and the neutral line 42 are connected to the second coil end portion 32, the volume of the second coil end portion 32 is larger than that of the first coil end portion 31. The second coil end portion 32 side to which the power line 41 and the neutral line 42 are connected is called a lead side. This is because the second coil end portion 32 is provided with a lead wire connected to the power line 41 and the neutral wire 42. The first coil end portion 31 side is called an anti-lead side.

Further, since the volume of the second coil end portion 32 (the amount of copper constituting the coil 30) is larger than the volume of the first coil end portion 31, the temperature of the second coil end portion 32 is changed to the first coil end portion. It tends to be higher than the temperature of 31. Further, the distance from the end portion 32 a of the second coil end portion 32 to the end face 21 b of the stator core 21 in the central axis direction (the length L2 of the second coil end portion 32) is from the end portion 31 a of the first coil end portion 31. It is longer than the distance to the end surface 21a of the stator core 21 (the length L1 of the first coil end portion 31). For this reason, since the distance to the contact surface (heat exchange surface) of the stator core 21 and the jacket part 50 mentioned later is longer in the second coil end part 32, the second coil end part 32 is in the first coil. It is less likely to be cooled than the end portion 31 and is likely to be hot.

(Cooling structure of rotating electric machine)
Next, a cooling structure 100 for the rotating electrical machine 1 will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, a jacket portion 50 is provided so as to cover the outer peripheral surface 21 c of the stator core 21. A flow path 51 through which a coolant for cooling the stator core 21 flows is provided in the jacket portion 50. Specifically, the jacket portion 50 includes an inner jacket portion 52 that contacts the outer peripheral surface 21 c of the stator core 21, and an outer jacket portion 53 that is provided so as to cover the outer periphery of the inner jacket portion 52. Both the inner jacket portion 52 and the outer jacket portion 53 are formed of a material having a relatively high thermal conductivity such as aluminum. Both the inner jacket portion 52 and the outer jacket portion 53 have a cylindrical shape. The jacket portion 50 is attached to the stator core 21 by shrink fitting or the like. Thereby, the jacket portion 50 is in close contact with the stator core 21. The heat generated from the coil 30 is transferred to the jacket portion 50 via the stator core 21.

Further, a gap C is provided between the jacket portion 50 (inner jacket portion 52) and the first coil end portion 31 and the second coil end portion 32. This is to ensure insulation between the jacket portion 50 and the first coil end portion 31 and the second coil end portion 32. A part of the heat generated from the first coil end portion 31 and the second coil end portion 32 is transferred to the jacket portion 50 through the gap C (air).

Here, in the first embodiment, the refrigerant flows in the flow path 51 from the second coil end portion 32 side (X2 direction side) toward the first coil end portion 31 side (X1 direction side) in the central axis direction. It is configured as follows. Note that the refrigerant is, for example, water, oil, or ethylene glycol. Specifically, as shown in FIG. 2, the flow path 51 surrounds the outer peripheral surface 21 c of the stator core 21, and from the second coil end portion 32 side (X2 direction side) to the first coil end portion 31 side (X1 direction). Side). The term “spiral” means a curve that moves in a direction (center axis direction) perpendicular to the plane of rotation while rotating. Further, the turning radius is constant along the central axis direction. The refrigerant is configured to flow from the second coil end portion 32 side to the first coil end portion 31 side while rotating spirally.

In the first embodiment, the refrigerant flows from the refrigerant inlet port 56 to the outlet port 57 as a series of flow paths through which the refrigerant flows, and the portion of the series flow paths that contacts the stator core 21 via the inner jacket portion 52 is the highest. An inner diameter layer (specifically, a spiral channel 51, see FIG. 2) is used. Of the innermost diameter layer, a portion connected to the inflow port portion 56 is referred to as an innermost diameter layer inlet portion, and among the innermost diameter layer, a portion connected to the outlet port portion 57 is referred to as an innermost diameter layer outlet portion. The innermost layer inlet portion is disposed on the second coil end portion 32 side in the central axis direction, and the innermost layer outlet portion is disposed on the first coil end portion 31 side in the central axis direction. Yes. The innermost diameter layer is configured such that the refrigerant flows from the innermost diameter layer inlet portion toward the innermost diameter layer outlet portion in the central axis direction. In addition, the innermost diameter layer (spiral flow path 51) does not include a folded flow path from the innermost diameter layer inlet portion side toward the innermost diameter layer outlet portion side in the central axis direction. That is, the refrigerant is configured to flow from the second coil end portion 32 side (X2 direction side) to the first coil end portion 31 side (X1 direction side) while rotating spirally in the central axis direction. And does not flow from the X1 direction side to the X2 direction side.

Moreover, as shown in FIG. 1, the cross section of the flow path 51 has a substantially rectangular shape. Further, the cross-sectional shape (width and height) of the flow path 51 is substantially the same throughout the flow path 51. The inner jacket portion 52 is provided with a spiral wall portion 54 (groove portion 55). And the flow path 51 is comprised by the wall part 54 (groove part 55) being covered with the outer side jacket part 53. FIG. Note that the width W1 of the groove 55 is larger than the width W2 of the wall 54 in the central axis direction.

In the first embodiment, the flow path 51 overlaps the stator core 21, the first coil end portion 31, and the second coil end portion 32 when viewed from the direction orthogonal to the central axis direction. Is provided. Specifically, all portions of the stator core 21 and the first coil end portion 31 overlap the flow path 51. Further, the stator coil 21 side (X1 direction side) portion of the second coil end portion 32 overlaps the flow path 51.

In the first embodiment, the jacket portion 50 is provided with an inlet portion 56 for allowing the refrigerant to flow into the flow path 51. The inflow port portion 56 is provided closer to the second coil end portion 32 than the central portion C1 in the central axis direction of the stator core 21 (jacket portion 50). Specifically, the inflow port portion 56 is connected to the end portion 51a (the end portion 51a on the X2 direction side) of the spiral flow path 51. Further, the width W3 of the inflow port portion 56 in the central axis direction is smaller than the width W1 of the groove portion 55.

In the first embodiment, the inflow port portion 56 is provided so as to overlap the second coil end portion 32 when viewed from the direction orthogonal to the central axis direction. Specifically, the inflow port portion 56 overlaps the portion of the second coil end portion 32 on the stator core 21 side (X1 direction side).

In the first embodiment, the jacket part 50 is provided with an outlet part 57 for allowing the refrigerant to flow out of the flow path 51. The outlet part 57 is provided closer to the first coil end part 31 (X1 direction side) than the center part C1 in the central axis direction of the stator core 21 (jacket part 50). Specifically, the outflow port 57 is connected to the end 51b side (the end 51b side on the X1 direction side) of the spiral flow path 51. The outlet 57 is not connected to the end 51b of the flow channel 51 but to a position shifted by one groove 55 from the end 51b to the X2 direction (second groove 55 from the X1 side). ing. Further, the width W4 of the outlet portion 57 in the central axis direction is smaller than the width W1 of the groove portion 55.

Further, in the first embodiment, the outlet part 57 is provided so as to overlap the first coil end part 31 when viewed from the direction orthogonal to the central axis direction. Specifically, the outflow port portion 57 overlaps the portion of the first coil end portion 31 on the stator core 21 side (X2 direction side).

Moreover, the jacket part 50 has a flange shape. The jacket portion 50 is fixed to the housing 60 with screws 61.

Further, as shown by the thick broken line in FIG. 1, in the rotating electrical machine 1, the oil that has passed through the shaft 13 is sprayed on the first coil end portion 31 and the second coil end portion 32, thereby The part 31 and the second coil end part 32 are cooled.

(Temperature distribution of rotating electrical machines)
Next, with reference to FIG. 3, the temperature distribution (result by simulation) of the rotating electrical machine 1 will be described in comparison with the cooling structure 200 of the comparative example.

As shown in FIG. 3, in the cooling structure 200 for the rotating electrical machine 1 according to the comparative example, the inlet portion 156 is provided on the first coil end portion 31 side (X1 direction side) of the jacket portion 150, and the second coil end portion 32. A spout portion 157 is provided on the side (X2 direction side). That is, the flow direction of the refrigerant in the cooling structure 200 according to the comparative example is opposite to the flow direction of the refrigerant in the cooling structure 100 of the first embodiment.

As shown in FIG. 3, the temperature of the first coil end portion 31 is T1 ° C., the temperature of the slot accommodating portion (the portion disposed in the slot of the coil 30) is T2 ° C., and the second coil. It was confirmed that the temperature of the end portion 32 was T3 ° C. T1, T2, and T3 have a relationship of T3> T1> T2. The difference between T3 and T1 (T3−T1) was about 20 ° C.

Further, it was confirmed that the temperature of the refrigerant (water) flowing through the jacket portion 150 was T11 ° C. on the first coil end portion 31 side and T12 ° C. (> T11) on the second coil end portion 32 side. The difference between T11 and T12 (T12−T11) was about 9 ° C.

Also, it was confirmed that the temperature inside the rotating electrical machine 1 was T21 ° C. on the first coil end portion 31 side and T22 ° C. (> T21) on the second coil end portion 32 side. The difference between T21 and T22 (T22−T21) was about 13 ° C.

Further, it was confirmed that the temperature in the vicinity of the bearing 14 was T31 ° C. on the first coil end portion 31 side and T32 ° C. (> T31) on the second coil end portion 32 side. The difference between T31 and T32 (T32−T31) was about 10 ° C.

Further, it was confirmed that the temperature of the outer surface of the rotating electrical machine 1 was T41 ° C. on the first coil end portion 31 side and T42 ° C. (> T41) on the second coil end portion 32 side. The difference between T41 and T42 (T42−T41) was about 4 ° C.

Further, it was confirmed that the temperature of the atmosphere outside the rotating electrical machine 1 was T51 ° C. on the first coil end portion 31 side and T52 ° C. (> T51) on the second coil end portion 32 side. The difference between T51 and T52 (T52−T51) was about 20 ° C.

As described above, since the temperature difference (about 20 ° C.) between the first coil end portion 31 and the second coil end portion 32 is particularly large, the first coil end portion 31 side and the second coil end portion of the rotating electrical machine 1 are large. It was found that there was a temperature difference on the 32 side. In the cooling structure 200 according to the comparative example, since the refrigerant flows in from the first coil end portion 31 side, when the refrigerant passes through the second coil end portion 32 side having a relatively large calorific value, the temperature of the refrigerant (T12 ° C) has increased by about 9 ° C. For this reason, since the 2nd coil end part 32 side cannot be cooled effectively, it is thought that the temperature difference of the 1st coil end part 31 and the 2nd coil end part 32 becomes comparatively large.

On the other hand, in the cooling structure 100 for the rotating electrical machine 1 according to the first embodiment, the refrigerant flows from the second coil end portion 32 side. Thereby, the relatively high temperature second coil end portion 32 side is cooled by the relatively low temperature refrigerant. As a result, the temperature difference (T3−T2) between the temperature T1 of the first coil end portion 31 and the temperature T3 of the second coil end portion 32 becomes approximately 0 ° C. Thereby, the temperature difference of the 1st coil end part 31 side of the rotary electric machine 1 and the 2nd coil end part 32 side is reduced.

[Second Embodiment]
Next, with reference to FIG. 4, the cooling structure 300 of the rotary electric machine 1 of 2nd Embodiment is demonstrated. In the cooling structure 300, the outlet portion 257 is provided so as to be adjacent to the inlet portion 256.

In the cooling structure 300 of the rotating electrical machine 1, the outlet portion 257 is provided so as to be adjacent to the inlet portion 256 on the second coil end portion 32 side with respect to the central portion C <b> 2 in the central axis direction of the stator core 21 (jacket portion 250). It has been. Specifically, the flow path 251 is spirally provided from the second coil end portion 32 side to the first coil end portion 31 side, and then connected to the outlet portion 257 through the outer peripheral side of the jacket portion 250. ing.

[Effects of the first and second embodiments]
In the first and second embodiments, the following effects can be obtained.

In the first and second embodiments, as described above, the refrigerant moves from the second coil end portion (32) side having a large volume to the first coil end portion (31) side having a small volume in the central axis direction. It is comprised so that a flow path (51,251) may flow toward. Accordingly, the refrigerant flows from the second coil end portion (32) side having a large volume (relatively high temperature) in a state where the refrigerant temperature is relatively low. As a result, since the second coil end portion (32) side having a relatively high temperature is efficiently cooled, the temperature on the second coil end portion (32) side can be lowered relatively greatly. Thereby, the degree of temperature decrease on the second coil end part (32) side becomes larger than the degree of temperature decrease on the first coil end part (31) side. As a result, the temperature on the second coil end portion (32) side can be brought close to the temperature on the first coil end portion (31) side, so that the first side and the other side in the central axis direction of the stator core (21) Even when the volume of the first coil end portion (31) is different from the volume of the second coil end portion (32), the temperature difference between one side and the other side in the central axis direction of the rotating electrical machine (1) is reduced. Can do.

In the first and second embodiments, as described above, the protrusion length (L2) of the second coil end portion (32) from the end surface (21b) in the central axis direction of the stator core (21) is the first length. The coil end portion (31) is configured to be longer than the protruding length (L1) from the end surface (21a) in the central axis direction of the stator core (21). As described above, the second coil end portion (32) side having the large protrusion length (L2) also has a large calorific value, so that it is cooled by the refrigerant having a relatively low temperature, so that the rotating electric machine (1) The temperature difference between the one side and the other side in the central axis direction can be effectively reduced.

In the first and second embodiments, as described above, the second coil end portion (32) is connected to the power line (41) for supplying power to the coil (30) and the neutral point. At least one of the lines (42) is configured to be connected. If comprised in this way, the state where the temperature is comparatively low in the 2nd coil end part (32) side whose volume will become large when at least one of a power line (41) and a neutral line (42) is connected. Therefore, the temperature difference between the one side and the other side in the central axis direction of the rotating electrical machine (1) can be effectively reduced.

In the first and second embodiments, as described above, the flow path (51, 251) includes the stator core (21) and the first coil end portion (31) as viewed from the direction orthogonal to the central axis direction. ) And the second coil end portion (32). If comprised in this way, all of a stator core (21), a 1st coil end part (31), and a 2nd coil end part (32) will be cooled with the refrigerant | coolant which flows through a flow path (51,251). Therefore, the temperature of the rotating electrical machine (1) can be further reduced.

Moreover, in 1st and 2nd embodiment, as above-mentioned, an inflow port part (56,256) is a 2nd coil end part (C1, C2) rather than the center part (C1, C2) in the center axis direction of a stator core (21). 32) side. If comprised in this way, a refrigerant | coolant can be easily poured from the 2nd coil end part (32) side to the 1st coil end part (31) side.

In the first and second embodiments, as described above, the inflow port portions (56, 256) overlap the second coil end portion (32) when viewed from the direction orthogonal to the central axis direction. It is provided to do. If comprised in this way, compared with the case where the inflow port part (56,256) overlaps with the stator core (21), a refrigerant | coolant is more upstream (center axial direction outer side of a 2nd coil end part (32)). The temperature of the rotating electrical machine (1) can be further lowered.

Moreover, in 1st Embodiment, as above-mentioned, an outflow port part (57) is provided in the 1st coil end part (31) side rather than the center part (C1) in the center axis direction of a stator core (21). Yes. If comprised in this way, the refrigerant | coolant which flowed toward the 1st coil end part (31) side from the 2nd coil end part (32) side can be easily flowed out from an outflow port part (57).

In the second embodiment, as described above, the outlet portion (257) is closer to the second coil end portion (32) than the center portion (C2) in the central axis direction of the stator core (21). (256) is provided adjacent to it. If comprised in this way, since an inflow port part (256) and an outflow port part (257) are arrange | positioned in the comparatively near position, piping (inlet port part (256) and outflow port part (257) which circulates a refrigerant | coolant. ) And the length of the piping for circulating the refrigerant connected to.

In the first embodiment, as described above, the outlet portion (57) is provided so as to overlap the first coil end portion (31) when viewed from the direction orthogonal to the central axis direction. ing. If comprised in this way, compared with the case where the outflow port part (57) overlaps with the stator core (21), a refrigerant | coolant is more downstream (end of the axial direction outer side of a 1st coil end part (31)). Part (31a) side), the first coil end part (31) itself can be cooled, and the temperature of the rotating electrical machine (1) can be further lowered.

In the first and second embodiments, as described above, the innermost diameter layer is configured such that the refrigerant flows from the innermost diameter layer inlet portion side toward the innermost diameter layer outlet portion side in the central axis direction. Yes. If comprised in this way, since a refrigerant | coolant flows toward the innermost diameter layer exit part side from the innermost diameter layer entrance part side in the innermost diameter layer arrange | positioned in the position comparatively close to a stator core (21), a rotary electric machine (1) The temperature difference between the one side and the other side in the central axis direction can be effectively reduced.

In the first and second embodiments, as described above, the innermost diameter layer (the spiral flow paths (51, 251)) is arranged in the direction of the central axis from the innermost diameter layer inlet portion side to the innermost diameter layer outlet portion. It does not include the folded channel that goes to the side. If comprised in this way, a refrigerant | coolant can be smoothly poured with respect to an innermost diameter layer.

In the first and second embodiments, as described above, the flow path (51, 251) surrounds the outer peripheral surface (21c) of the stator core (21) and also from the second coil end portion (32) side. It is provided in a spiral shape toward the one coil end portion (31) side. If comprised in this way, since a refrigerant | coolant flows spirally around the outer periphery of a stator core (21), the whole stator core (21) can be cooled effectively.

In the first and second embodiments, as described above, the refrigerant is, for example, water, oil, or ethylene glycol. If comprised in this way, compared with the case where a refrigerant | coolant is gas etc., cooling efficiency can be improved. Moreover, handling of the refrigerant can be facilitated.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

For example, in the first and second embodiments, the example in which the jacket portion is fixed by being shrink-fitted to the stator core is shown, but the present invention is not limited to this. For example, the jacket portion may be fixed to the stator core by a method other than shrink fitting.

Further, in the first and second embodiments, the example in which the coil is formed by a flat wire is shown, but the present invention is not limited to this. For example, the coil may be comprised by conducting wires (round wire etc.) other than a rectangular conducting wire.

In the first and second embodiments, the second coil end portion is connected to both the power line and the neutral line. However, the present invention is not limited to this. For example, the second coil end portion may be connected to only one of the power line and the neutral line.

In the first and second embodiments, the flow path overlaps with the stator core, the first coil end portion, and the second coil end portion as seen from the direction orthogonal to the central axis direction. Although the example provided is shown, this invention is not limited to this. For example, the flow path may overlap the stator core (only the stator core) without overlapping the first coil end portion and the second coil end portion. If comprised in this way, since the full length of a flow path is shortened, a cooling structure can be simplified.

In the first and second embodiments, the example in which the inlet portion overlaps the second coil end portion is shown, but the present invention is not limited to this. For example, the inlet portion may overlap the stator core without overlapping the second coil end portion.

In the first embodiment, the example in which the outlet portion overlaps the first coil end portion is shown, but the present invention is not limited to this. For example, the outlet portion may overlap the stator core without overlapping the first coil end portion.

In the first and second embodiments, the example in which the flow path is provided in a spiral shape is shown, but the present invention is not limited to this. For example, the flow path 351 may be provided in a labyrinth shape as in the cooling structure 400 according to the modification shown in FIG. FIG. 5 shows a state where the flow path 351 (inner jacket portion) is developed. The refrigerant flowing in from the inflow port portion 356 flows from the second coil end portion 32 side (X2 direction side) to the first coil end portion 31 side (X1 direction side) and flows out from the outflow port portion 357.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 11 Rotor core 21 Stator core 21a End surface 21b End surface 21c Outer peripheral surface 30 Coil 31 1st coil end part 32 2nd coil end part 41 Power line 42 Neutral wire 50, 250 Jacket part 51,251,351 Flow path 56,256 356 Inlet part 57, 257, 357 Outlet part 100, 300, 400 Cooling structure C1, C2 Central part

Claims (13)

A cooling structure for a rotating electrical machine comprising a rotor core and a stator core provided to face the rotor core and in which a coil is disposed,
A jacket portion provided to cover the outer peripheral surface of the stator core, and provided with a flow path through which a coolant for cooling the stator core flows;
The coil is a first coil end portion that protrudes from one end surface in the central axis direction of the stator core, and a portion that protrudes from the other end surface in the central axis direction of the stator core, and the first coil end A second coil end portion having a volume larger than the volume of the portion,
A cooling structure for a rotating electric machine, wherein the refrigerant is configured to flow in the flow path from the second coil end portion side toward the first coil end portion side in a central axis direction. The protruding length of the second coil end portion from the end surface in the central axis direction of the stator core is configured to be larger than the protruding length of the first coil end portion from the end surface in the central axis direction of the stator core. The cooling structure for a rotating electrical machine according to claim 1. The said 2nd coil end part is comprised so that at least one of the power wire which supplies electric power to the said coil, and the neutral wire connected to a neutral point may be connected. The rotating electrical machine cooling structure described. 2. The flow path is provided so as to overlap the stator core, the first coil end portion, and the second coil end portion when viewed from a direction orthogonal to a central axis direction. 4. The cooling structure for a rotating electric machine according to any one of items 1 to 3. When viewed from a direction perpendicular to the central axis direction, the flow path is provided so as not to overlap the first coil end portion and the second coil end portion but to overlap the stator core. The rotating electrical machine cooling structure according to any one of claims 1 to 3. The jacket portion includes an inlet portion for allowing the refrigerant to flow into the flow path,
The cooling structure for a rotating electrical machine according to any one of claims 1 to 5, wherein the inflow port portion is provided closer to the second coil end portion than a central portion in a central axis direction of the stator core. The cooling structure for a rotating electrical machine according to claim 6, wherein the inlet portion is provided so as to overlap the second coil end portion when viewed from a direction orthogonal to the central axis direction. The jacket part further includes an outlet part for allowing the refrigerant to flow out of the flow path,
The outlet portion is provided closer to the first coil end portion than the central portion in the central axis direction of the stator core, or is closer to the second coil end portion than the central portion in the central axis direction of the stator core. The cooling structure for a rotating electrical machine according to claim 6, wherein the cooling structure is provided adjacent to the inlet portion. The outlet portion is provided closer to the first coil end portion than the center portion in the central axis direction of the stator core, and the first coil end portion is viewed from a direction orthogonal to the central axis direction. The cooling structure for a rotating electric machine according to claim 8, wherein the cooling structure is provided so as to overlap with each other. The jacket portion includes an inner jacket portion that contacts an outer peripheral surface of the stator core,
A series of flow paths through which the refrigerant flows from the inlet part to the outlet part of the refrigerant, and a part of the series flow path that contacts the stator core via the inner jacket part is an innermost diameter layer, Of the innermost diameter layer, the portion connected to the inlet portion is the innermost diameter layer inlet portion, and among the innermost diameter layer, the portion connected to the outlet portion is the innermost diameter layer outlet portion,
The innermost diameter layer inlet portion is disposed on the second coil end portion side in the central axis direction, and the innermost diameter layer outlet portion is disposed on the first coil end portion side in the central axis direction. And
The cooling of the rotating electrical machine according to claim 8 or 9, wherein the innermost diameter layer is configured such that the refrigerant flows from the innermost diameter layer inlet portion toward the innermost diameter layer outlet portion in a central axis direction. Construction. The cooling structure for a rotating electrical machine according to claim 10, wherein the innermost diameter layer does not include a return flow path from the innermost diameter layer inlet portion side toward the innermost diameter layer outlet portion side in the central axis direction. The flow path surrounds the outer peripheral surface of the stator core and is provided in a spiral shape from the second coil end portion side to the first coil end portion side. The rotating electrical machine cooling structure described in 1. The cooling structure for a rotating electric machine according to any one of claims 1 to 12, wherein the refrigerant includes water.

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