JP2015146704A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which cools a rotary part and an inverter part with a simple structure.SOLUTION: An inverter part 30 for controlling a current of a rotary part having a stator and a rotor is provided near a coil end 213 that is an end part of a coil 212 included in the rotary part. A cooling part 40 having a passage 410, in which water flows, is provided between the inverter part 30 and the coil end 213. The cooling part 40 is provided so as to contact with the inverter part 30 and form a gap 400 with the coil end 213. An oil 5 for cooling the coil end 213 passes through the gap 400 from the top side to the ground side. Heat from the oil 5 passing through the gap 400 is transmitted to water through third fins 413, a wall body 402 of the cooling part 40, and second fins 412. The structure allows the cooling part 40 to cool both of the rotary part and the inverter part 30.

Description

  The present invention relates to a rotating electrical machine.

  2. Description of the Related Art Conventionally, a rotating electrical machine that generates rotational torque by an electric current supplied from the outside or generates an electric current by rotational torque input from the outside has a cooling function for cooling each part constituting the rotating electrical machine. For example, Patent Document 1 describes a rotating electrical machine in which cooling oil is dropped onto an end of a winding wound around a rotating unit that generates rotational torque or current. Patent Document 2 describes a rotating electrical machine that includes a cooling unit that abuts on an inverter unit that controls a current flowing through a winding and cools the inverter unit.

JP 2006-31750 A JP 2007-116840 A

  However, in the rotating electrical machine described in Patent Document 1, the oil cools only the rotating part. In the rotating electrical machine described in Patent Document 2, the cooling unit cools the inverter unit, while the wall of the housing is provided between the end of the winding and the cooling unit. It cannot be cooled.

  The objective of this invention is providing the rotary electric machine which cools a rotation part and an inverter part by simple structure.

  The present invention relates to a rotating part that generates rotational torque by a current housed in a housing and is supplied from outside, or generates an electric current by rotational torque input from the outside, an inverter part that is housed in the housing, and an inverter part. And a cooling unit that is provided so as to form a gap between the rotating unit and the first fluid flows therein, and the gap formed between the rotating unit and the cooling unit is the rotating unit. The second fluid for cooling the fluid flows.

  While the cooling unit included in the rotating electrical machine of the present invention contacts the inverter unit, the rotating unit forms a gap that allows the second fluid to flow. Heat generated in the rotating part is transmitted to the second fluid flowing through the gap between the cooling part and the rotating part. The heat transmitted to the second fluid is transmitted to the first fluid flowing through the inside of the cooling unit via the wall on the rotating unit side of the cooling unit. Thereby, the heat of the rotating part is radiated not only by the second fluid but also by the first fluid. Therefore, both the inverter unit and the rotating unit can be cooled with a simple configuration.

It is sectional drawing of the rotary electric machine by 1st Embodiment of this invention. It is an enlarged view of the II section of FIG. It is a schematic diagram of the cooling unit of the rotating electrical machine according to the first embodiment of the present invention. It is sectional drawing of the cooling part of the rotary electric machine by 1st Embodiment of this invention. It is sectional drawing of the cooling part of the rotary electric machine by 2nd Embodiment of this invention. It is sectional drawing of the cooling unit of the rotary electric machine by 3rd Embodiment of this invention. It is sectional drawing of the cooling part of the rotary electric machine by 4th Embodiment of this invention.

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

(First embodiment)
A rotating electrical machine according to a first embodiment of the present invention will be described with reference to FIGS.
The rotating electrical machine 1 according to the first embodiment is used, for example, in a motor drive system (not shown) that drives a hybrid vehicle or an electric vehicle. The rotating electrical machine 1 generates rotational torque or electric power according to the driving state of a hybrid vehicle or the like. The rotating electrical machine 1 includes a housing 10, a rotating unit 20, a plurality of inverter units 30, a cooling unit 40, and the like. 1, 2, and 4, the upper side of the paper is the “top” side, and the lower side of the paper is the “ground” side.

  The housing 10 is formed in a bottomed cylindrical shape so as to have a cylindrical interior. The housing 10 is formed of a cylindrical portion 11 and two bottom portions 12 and 13 provided so as to close both ends of the cylindrical portion 11. The cylindrical portion 11 is provided with inlets 111 and 112 and a outlet 113 through which two types of refrigerant supplied into the housing 10 flow. The inlet 111 is connected to a cooling unit 40 described later. The introduction port 112 is provided on the top side of the cylindrical portion 11. The inlet 112 drops a refrigerant different from the refrigerant flowing through the inlet 111 into the housing 10. The outlet 113 is provided on the ground side of the cylindrical portion 11 and discharges the refrigerant dropped into the housing 10 through the inlet 112 to the outside of the housing 10. The housing 10 accommodates the rotating unit 20, the inverter unit 30, the cooling unit 40, and the like.

  The rotating unit 20 generates a rotational torque by a current supplied from the outside, or generates a current by a rotational torque input from the outside. The rotating unit 20 includes a stator 21, a rotor 23, a shaft 24, and the like.

A plurality of stators 21 are provided in an arc shape on the radially inner side of the cylindrical portion 11 of the housing 10. In FIG. 1, two stators provided so as to sandwich the shaft 24 are shown, but actually, a plurality of stators are provided in the circumferential direction along the inner wall of the cylindrical portion 11.
The stator 21 is formed of a stator iron core 211, a winding 212, and the like. The stator core 211 is formed by laminating a plurality of thin metal plates. Winding 212 is wound around stator core 211 to form a coil. Here, in the stator 21, the windings 212 protruding from both sides in the central axis direction of the rotating portion 20 of the stator core 211 are coil ends 213 and 214 as “end portions in the central axis direction of the rotating portion of the winding”. .

  The rotor 23 is provided inside the stator 21 in the radial direction. The rotor 23 is composed of a rotor core 231, magnets 232, 233, and the like. The rotor core 231 is formed to extend radially outward from the central axis of the rotating unit 20. A through hole 234 through which the shaft 25 is inserted is formed in the center of the rotor iron core 231. Magnets 232 and 242 having different polarities are provided at the radially outer end of the rotor core 231.

  The shaft 24 is provided on the central axis of the rotating unit 20. One end 241 of the shaft 24 is rotatably supported by a bearing 121 provided on the inner wall of the bottom 12 of the housing 10. The other end portion 242 of the shaft 24 is rotatably supported by a bearing portion 131 provided on the inner wall of the bottom portion 13 of the housing 10, and is inserted into a through hole 132 formed in the bottom portion 13 and protrudes to the outside. .

  The inverter unit 30 controls the magnitude and direction of the current flowing through the winding 212. The inverter unit 30 includes an inverter case 31, a semiconductor module 32, a control circuit 33, an insulating member 34, and the like. FIG. 1 shows two inverter units 30 corresponding to the two stators 21, but actually, one inverter unit is provided for each of the plurality of stators of the rotating electrical machine 1. .

  The inverter case 31 is a substantially rectangular parallelepiped member, and the wall body 311 in contact with the cooling unit 40 is formed of a metal having excellent thermal conductivity. The inverter case 31 accommodates therein a semiconductor module 32 that controls the power supplied to the windings, a control circuit 33 that controls the operation of the semiconductor module 32, an insulating member 34 that insulates the semiconductor module 32 and the cooling unit 40, and the like. To do.

  The cooling unit 40 is provided between the rotating unit 20 and the inverter unit 30. As shown in FIG. 4, the cooling unit 40 is formed so that its cross section has an annular shape. The cooling unit 40 includes a refrigerant circulation unit 41, a receiving unit 42, and the like. 4 shows a cross-sectional view of the refrigerant circulation part 41 on the right side of the drawing, and the left side of FIG. 4 shows the appearance of the cooling unit 40 as viewed from the rotating unit 20 side. Further, an arrow F1 shown in FIG. 4 indicates the flow direction of the refrigerant flowing inside the refrigerant circulation portion 41.

  The refrigerant circulation part 41 is made of a metal having excellent thermal conductivity. The refrigerant circulation part 41 is formed so that the inside and the outside are liquid-tight. Inside the refrigerant circulation part 41, for example, a flow path 410 through which water flows is formed as a “first fluid”. Yes. The wall body 401 on the inverter part 30 side of the refrigerant circulation part 41 is provided so as to come into contact with the wall body 311 on the rotating part 20 side of the inverter case 31. On the other hand, a gap 400 is formed between the wall 402 on the rotating part 20 side of the refrigerant circulation part 41 and the coil end 213.

A plurality of first fins 411 are formed on the inner wall of the wall body 401 forming the flow path 410. As shown in FIG. 4, the first fin 411 is formed in an arc shape along the shape of the refrigerant circulation portion 41 formed in an arc shape corresponding to the position where the inverter unit 30 is provided.
A plurality of second fins 412 are formed on the inner wall of the wall body 402 forming the flow path 410. As shown in FIG. 4, the second fin 412 follows the shape of the refrigerant circulation part 41 between the first fins 411 in the flow direction of the water flowing through the flow path 410, that is, at a position where the inverter part 30 is not provided. It is formed in a circular arc shape.

FIG. 3 is an exploded perspective view showing the positional relationship and the size relationship between the first fins 411 and the second fins 412 in the refrigerant circulation part 41. An arrow F <b> 1 illustrated in FIG. 3 indicates a flow direction of water flowing inside the refrigerant circulation unit 41. In FIG. 3, in order to make the relationship between the sizes of the first fins 411 and the second fins 412 easier to understand, the wall body 401 and the wall body 402 are separated from the actual state, and the flow path 410 is represented in a straight line. .
As shown in FIG. 3, the first fin 411 is formed such that the length L <b> 1 along the water flow direction F <b> 1 is longer than the length L <b> 2 of the second fin 412. The first fins 411 are formed to be denser than the second fins 412. Specifically, the number of the first fins 411 in the direction perpendicular to the water flow direction F1 is 11, and the number of the second fins 412 in the direction perpendicular to the water flow direction F1. Five. However, the number of the first fins 411 and the second fins 412 is not limited to this.

  A plurality of third fins 413 are formed on the outer wall of the wall portion 402 of the refrigerant circulation portion 41 on the rotating portion 20 side. The third fin 413 comes into contact with the oil 5 when, for example, the insulating oil 5 as the “second fluid” dropped from the inlet 112 flows along the outer wall 215 of the coil end 213 on the inverter part 30 side. .

  As shown in FIG. 1, the receiving portion 42 is provided so as to protrude in the central axis direction of the rotating portion 20 on the radially inner side of the cooling portion 40. As shown in FIG. 2, the receiving portion 42 is provided so as to receive the oil 5 flowing between the outer wall 215 of the coil end 213 and the outer wall of the wall body 402 of the refrigerant circulation portion 41.

Next, the operation of the rotating electrical machine 1 will be described.
When current is supplied to the rotating unit 20 from a power source (not shown), current flows through the winding 212 of the stator 21, and a magnetic field is formed in a region including the stator 21. When the shaft 24 connected to the rotor 23 is rotated by the action and reaction force between the magnets 232 and 233 of the rotor 23 and the magnetic field in the region, the rotational torque of the shaft 24 is output to the outside.
When a rotational torque is input to the shaft 24 from the outside, the rotor 23 rotates and the magnetic field formed by the magnets 232 and 233 changes. In response to the change in the magnetic field, the current flowing through the winding 212 of the stator 21 is output to the outside.

When rotating torque or current is output in the rotating electrical machine 1, the inverter unit 30 that is at a relatively high temperature is cooled by water flowing through the flow path 410 of the cooling unit 40 that contacts the inverter case 31. The water is sent to a first refrigerant supply unit 46 provided outside the housing 10 through a lead-out port (not shown). In the first refrigerant supply unit 46, the pressure of water is increased by the pump 461 and then cooled by the heat exchange unit 462. The cooled water is supplied to the cooling unit 40 through the inlet 111. Further, the coil end 213 of the winding 212, which becomes relatively hot when an electric current flows, is cooled by the oil 5 dripped from the inlet 112. Is done. The oil 5 is dropped into the housing 10 from the inlet 112 and then discharged to the outside from the outlet 113. The discharged oil 5 is sent to a second refrigerant supply unit 47 provided outside the housing 10. In the second refrigerant supply unit 47, the oil 5 is boosted by the pump 471 and then cooled by the heat exchange unit 472. The cooled oil 5 is dropped again into the housing 10 through the inlet 112.

  In the rotating electrical machine 1 according to the first embodiment, the cooling unit 40 that cools the inverter unit 30 is in contact with the inverter unit 30, while the coil end 213 of the rotating unit 20 has a gap that allows oil 5 to flow. 400 is formed. As a result, the heat transmitted from the coil end 213 to the oil 5 is also transmitted to the water flowing through the flow path 410 via the wall body 402 of the refrigerant circulation portion 41. Therefore, in the rotating electrical machine 1, the rotating unit 20 can be cooled with the two refrigerants of oil and water, and both the rotating unit 20 and the inverter unit 30 can be cooled by the single cooling unit 40.

  A second fin 412 that comes into contact with water is provided on the inner wall of the wall body 402 that forms the flow path 410. A third fin 413 that contacts the oil 5 is provided on the outer wall of the wall body 402. Thereby, the heat of the oil 5 is efficiently transmitted to the water through the third fins 413, the wall body 402, and the second fins 412. Therefore, the coil end 213 can be efficiently cooled.

  The first fin 411 provided at a position corresponding to the inverter unit 30 is formed such that the length L1 in the flow direction F1 of the water flowing through the flow path 410 is longer than the length L2 of the second fin 412. In the rotating electrical machine 1, since the inverter unit 30 is likely to be hotter than the coil end 213, it is transmitted to the water via the first fin 411 compared to the heat amount of the coil end 213 that is transmitted to the water via the second fin 412. The amount of heat of the inverter unit 30 is increased. Thereby, the inverter part 30 which becomes comparatively high temperature can be cooled efficiently.

  As shown in FIG. 3, the cooling unit 40 is formed such that the first fins 411 are denser than the second fins 412. In the rotating electrical machine 1, the first fins 411 provided on the inverter unit 30 side that is at a relatively high temperature are arranged denser than the second fins 412 to increase the pressure loss of the flowing water, and the water and the fins are in contact with each other. Increase the area. Thereby, the heat quantity of the inverter unit 30 transmitted to the water through the first fin 411 is made larger than the heat quantity of the coil end 213 transmitted to the water through the second fin 412. Therefore, the inverter unit 30 that is relatively high in temperature can be further efficiently cooled.

  The cooling part 40 is provided with a receiving part 42 for receiving the oil 5 flowing between the outer wall 215 of the coil end 213 and the outer wall of the wall body 402 of the refrigerant circulation part 41 on the ground side of the cooling part. Thereby, the oil 5 that cools the coil end 213 stays in the gap 400 for a relatively long time, and the time during which the oil 5 contacts the third fin 413 and the wall body 402 becomes long. Therefore, it takes a long time for the heat of the oil 5 to be transferred to the water flowing through the flow path 410, and the coil end 213 can be efficiently cooled.

(Second Embodiment)
Next, a rotating electrical machine according to a second embodiment of the present invention will be described with reference to FIG. In 2nd Embodiment, the position in which the 2nd fin with respect to the 1st fin of a cooling unit is provided differs from 1st Embodiment. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 1st Embodiment, and description is abbreviate | omitted.

  In the rotating electrical machine according to the second embodiment, the first fin 511 and the second fin 512 are provided in the refrigerant circulation part 51 of the cooling part 40. The first fins 511 are provided on the inner wall of the wall on the inverter part 30 side of the refrigerant circulation part 51 that forms the flow path 510. The second fin 512 is provided on the inner wall of the wall body on the coil end 213 side of the refrigerant flow part 51 that forms the flow path 510.

  FIG. 5 shows a cross-sectional view of the refrigerant circulation part 51. As shown in FIG. 5, the first fins 511 are provided so as to correspond to the positions where the plurality of inverter units 30 are provided. The second fins 512 are formed in an arc shape so as to follow the shape of the refrigerant circulation part 41 between the first fins 511 in the flow direction of the water flowing through the flow path 510. Further, the first fins 511 and the second fins 512 are provided so as to be offset in a direction non-parallel to the water flow direction, for example, in the radial direction of the refrigerant circulation portion 51 as shown in FIG.

  The water flowing through the flow path 510 branches when it moves from the region where the first fins 511 are provided to the region where the second fins 512 are provided. Specifically, the water flowing between the first fins 511 adjacent to each other in the radial direction of the refrigerant circulation portion 51 among the first fins 511 corresponding to one inverter unit 30 as indicated by an arrow F2 representing the flow direction of water. When moving to the area where the second fin 512 is provided, the end collides with the end of the second fin 512 and branches into at least two flows. Further, when the water flowing between the second fins 512 adjacent to each other in the radial direction of the refrigerant circulation portion 51 moves to the region where the first fins 511 are provided, the water collides with the end portions of the first fins 511, and at least two or more Branch into the flow.

  In the rotating electrical machine according to the second embodiment, the water flowing between the first fins 511 adjacent to each other in the radial direction of the refrigerant circulation portion 51 is branched by the end portions of the second fins 512. Further, the water flowing between the second fins 512 adjacent to each other in the radial direction of the coolant circulation part 51 is branched by the end portions of the first fins 511. As a result, the water flowing through the flow path 510 of the refrigerant circulation part 51 repeatedly collides with the first fins 511 and the second fins 512, and the flow is disturbed. Exchange is performed efficiently. Therefore, 2nd Embodiment has the same effect as 1st Embodiment, and also can cool coil end 213 and inverter part 30 efficiently.

(Third embodiment)
Next, a rotating electrical machine according to a third embodiment of the present invention will be described with reference to FIG. In 3rd Embodiment, the shape of the 1st fin of a cooling unit differs from 1st Embodiment. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 1st Embodiment, and description is abbreviate | omitted.

  In the rotating electrical machine according to the third embodiment, the first fin 611 and the second fin 412 are provided in the refrigerant circulation part 61 of the cooling part 40. The first fin 611 is provided on the inner wall of the wall on the inverter part 63 side of the refrigerant circulation part 61 that forms the flow path 610. Note that an arrow F <b> 3 illustrated in FIG. 6 indicates the flow direction of the water flowing through the flow path 610.

  FIG. 6 shows a cross-sectional view of the refrigerant circulation part 61. As shown in FIG. 6, the first fins 611 are provided so as to correspond to positions where the plurality of inverter units 63 are provided. In the rotating electrical machine according to the third embodiment, the inverter unit 63 is smaller than the inverter unit 30 of the first embodiment, and is provided so as to be positioned on the radially inner side of the cooling unit 40. Of the first fins 611, the first fins 611 provided on the radially inner side of the refrigerant circulation portion 61 are formed densely. On the other hand, the first fin 611 provided on the radially outer side of the refrigerant circulation portion 61 is formed to be thicker than the first fin 611 provided on the radially inner side.

  In the rotating electrical machine according to the third embodiment, a relatively small number of first fins 611 are provided on the radially inner side where the inverter unit 63 is provided, compared to the radially outer side. Thereby, the efficiency of the heat transfer in the radial direction inner side where the inverter part 63 is provided is improved, and the inverter part 63 is cooled efficiently. Therefore, 3rd Embodiment has the same effect as 1st Embodiment, and also can cool inverter part 30 efficiently.

(Fourth embodiment)
Next, a rotating electrical machine according to a fourth embodiment of the present invention will be described with reference to FIG. In 4th Embodiment, the shape of the 1st fin and 2nd fin of a cooling unit differs from 1st Embodiment. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 1st Embodiment, and description is abbreviate | omitted.

  In the rotating electrical machine according to the fourth embodiment, the first fin 711 and the second fin 712 are provided in the refrigerant circulation portion 71 of the cooling unit 40. The first fin 711 is provided on the inner wall of the wall on the inverter part 30 side of the refrigerant circulation part 71 that forms the flow path 710. The second fins 712 are provided on the inner wall of the wall body on the coil end 213 side of the refrigerant flow part 71 that forms the flow path 710.

  FIG. 7 shows a cross-sectional view of the refrigerant circulation part 71. As shown in FIG. 7, the first fins 711 are provided so as to correspond to the positions where the plurality of inverter units 30 are provided. The second fins 712 are provided so as to be positioned between the adjacent inverter units 30.

  As for the 1st fin 711 and the 2nd fin 712, the edge part of the downstream of the water which flows through the flow path 710 which the refrigerant | coolant distribution part 71 has is located in radial direction compared with the edge part of an upstream. Specifically, with respect to the water flowing as shown by an arrow F4 in FIG. 7, the downstream end portions of the plurality of first fins 711 and the second fins 712 are compared with the upstream end portions, and the refrigerant circulation portion 71. It is formed so as to approach the side wall 713 on the radially inner side.

  In the rotating electrical machine according to the fourth embodiment, the water flowing through the flow path 710 flows in the radially inward direction of the refrigerant circulation portion 71 by the first fin 711 and the second fin 712 whose downstream end is located in the radially inward direction. It flows while facing away. In the refrigerant circulation part 71 formed in an arc shape, the water flowing through the flow path 710 tends to flow radially outward due to the centrifugal force, and thus the amount of flowing water tends to be uneven. Therefore, in the rotating electrical machine according to the fourth embodiment, the first fins 711 and the second fins 712 cause water to be directed in the radial direction, thereby preventing the distribution of the portions to be cooled from becoming uneven. Therefore, 4th Embodiment has an effect of 1st Embodiment and can cool coil end 213 and inverter part 30 uniformly.

(Other embodiments)
(A) In the above-described embodiment, the cooling unit forms a gap between the coil end and the end on the inverter unit side. However, the position where the cooling unit is provided is not limited to this. It suffices to provide a gap through which oil flows between the inverter unit and the rotating unit and between the cooling unit and the rotating unit.

  (A) In the above-described embodiment, the cooling unit has the receiving unit that receives the oil flowing through the gap between the cooling unit and the end of the coil end. However, the receiving portion may not be provided. If the size of the gap between the cooling part and the end of the coil end is formed so that the oil can flow relatively slowly along the end of the coil end by the surface tension of the oil, the receiving part May not be present.

  (C) In the above-described embodiment, the cooling unit has the first fin, the second fin, and the third fin. However, these fins may not be provided.

  (D) In the first embodiment, the length of the first fin along the direction in which the water flows is longer than that of the second fin. However, the length relationship between the first fin and the second fin is not limited to this.

  (E) In the first embodiment, the first fins are formed denser than the second fins. However, the density relationship between the first fin and the second fin is not limited to this.

  (F) In the above-described embodiment, the coolant that flows through the flow path of the cooling unit is water, and the coolant that cools the coil end is oil. However, the refrigerant that flows through the flow path of the cooling unit and the refrigerant that cools the coil end are not limited thereto.

  As mentioned above, this invention is not limited to such embodiment, It can implement with a various form in the range which does not deviate from the summary.

1 ... rotating electric machine,
10 ・ ・ ・ Housing,
20 ... rotating part,
212 ... Winding,
21 ... Stator,
23 ... rotor,
24 ... shaft,
30 ・ ・ ・ Inverter part,
40, 50, 60, 70 ... cooling section,
400: A gap.

Claims (8)

A housing (10);
A stator (21) housed in the housing and wound with a winding (212), a rotor (23) provided radially inside the stator and rotatable relative to the stator, and integrally with the rotor A rotating part (20) having a rotating shaft (24) and generating a rotating torque by an electric current supplied from the outside or generating an electric current by a rotating torque inputted from the outside;
An inverter part (30) accommodated in the housing;
A cooling part (40, 50, 60, 70) provided so as to form a gap (400) between the rotating part and abutting against the inverter part;
With
The rotating electrical machine (1), wherein a second fluid that cools the rotating portion flows through the gap. The cooling part forms the gap between the end part (213) in the central axis direction of the rotating part of the winding,
2. The rotating electrical machine according to claim 1, wherein the second fluid flows while being in contact with an end portion in a central axis direction of the rotating portion of the winding.   The rotating electrical machine according to claim 1 or 2, wherein the cooling unit has a receiving part (42) on the ground side for receiving the second fluid flowing in the gap from the top side toward the ground side.   The cooling unit includes first fins (411, 511, 612, 712) formed on an inner wall on the inverter unit side forming flow paths (410, 510, 610, 710) through which the first fluid flows, the flow Second fins (412, 512, 712) formed on the inner wall on the rotating part side forming a path, and third fins (413) formed on the outer wall on the rotating part side forming the flow path. The rotating electrical machine according to any one of claims 1 to 3, further comprising:   The first fin is formed such that a length (L1) in the flow direction of the first fluid in the flow path is longer than a length (L2) of the second fin in a direction in which the first fluid flows. The rotating electrical machine according to claim 4.   The rotating electrical machine according to claim 4 or 5, wherein the first fins (411, 611) are formed denser than the second fins (412, 612).   The first fin (511) is formed to be offset with respect to the second fin (512) in a direction non-parallel to a direction in which the first fluid flows in the flow path. The rotating electrical machine according to any one of 4 to 6. The flow path is formed in an annular shape,
The first fin (711) and the second fin (712) are configured such that an end on the downstream side of the first fluid flowing through the flow path is compared with an end on the upstream side of the first fluid flowing through the flow path. The rotating electrical machine according to any one of claims 4 to 7, wherein the rotating electrical machine is located in a radial direction.

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