Rotating Electric Machine System

Abstract

To provide a rotary electric machine system having a high degree of freedom in layout when mounted on a mount object and an excellent cooling efficiency of a rotary electric machine.SOLUTION: A rotary electric machine system 10 includes a casing 14 which accommodates a rotary electric machine 12 and in which first ends (46a to 46d) of heat pipes (44a to 44d) are inserted, and a radiator 16 connected to second ends (48a to 48d) of the heat pipes. The heat pipe encloses a heat medium (82) therein, and heat is taken from this heat medium at the second ends connected to the radiator 16, whereby the heat medium is condensed. The first ends are curved in an arc shape along the inner peripheral surface of a casing 14 and on the outer peripheral side of the rotary electric machine 12 at least at two locations spaced apart along an axial direction of the casing 14. The radiator 16 is arranged near an end portion of the casing 14 in the axial direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine system including a rotating electric machine housed in a casing and a heat radiator. [Background technology]

[0002] A rotating electric machine is well known as a machine including a rotor including a rotating shaft and holding a permanent magnet, and a stator including an electromagnetic coil. The rotating electric machine functions as a generator when it extracts a current generated in the electromagnetic coil as the rotor rotates, and functions as a motor when it obtains power from a rotating shaft that rotates integrally with the rotor when current is passed through the electromagnetic coil. Recently, there has been a demand for this type of rotating electric machine to be compact while improving its output. This can be achieved by rotating the rotor at high speed, but in this case, the amount of heat generated in the rotating electric machine increases. If the amount of magnetic flux of the permanent magnet decreases due to this heat, the output of the rotating electric machine decreases.

[0003] Therefore, as described in Patent Document 1, an attempt has been made to house a rotating electric machine and a liquid-phase cooling medium in a casing and cool the rotating electric machine with the cooling medium. The cooling medium is in liquid phase at room temperature, and changes to gas phase when the rotating electric machine is cooled. The heat of the gas-phase cooling medium is absorbed by another cooling medium (cooling water, etc.) flowing through a flow passage formed in the casing. As a result, the cooling medium condenses and becomes liquid phase capable of re-cooling the rotating electric machine.

[0004] Patent Document 2 also proposes winding a number of heat pipes around a casing (referred to as the "heat collecting jacket" in Patent Document 2). In this case, the cooling medium enclosed in the heat pipes absorbs heat from the rotating electric machine and changes to a gas phase. The heat of the gas phase cooling medium is dissipated in a heat pipe heat dissipation section provided by bringing together the ends of the heat pipes at a position away from the casing. This causes the cooling medium to return to a liquid phase and move to the part wound around the heat collecting jacket (the heat pipe heat receiving section) to re-cool the rotating electric machine. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-14522 A [Patent Document 2] JP 2017-38489 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described in Patent Document 1, in order to condense a cooling medium with another cooling medium, equipment or a mechanism for circulating and supplying the other cooling medium to the casing is required, which increases the size of the rotating electric machine system including the rotating electric machine and also increases the running costs.

[0007] On the other hand, in the heat pipe described in Patent Document 2, the cooling medium sealed in the heat pipe that becomes gas phase in the rotating electric machine, which is the heat source, spontaneously moves to the heat dissipation section through the main passage in the heat pipe, and the cooling medium that becomes liquid phase in the heat dissipation section spontaneously moves to the rotating electric machine through the wick in the heat pipe. Therefore, it is not necessary to use another cooling medium to condense the cooling medium in the heat pipe, and no equipment or mechanism is required to circulate and supply another cooling medium. However, when a heat pipe heat dissipation section is provided as shown in Figures 2 to 5 of Patent Document 2, the heat pipe heat dissipation section extends outward in the diameter direction of the heat collection jacket. Therefore, the rotating electric machine system including the heat collection jacket and the heat pipe becomes large.

[0008] If a rotating electric machine system is large in size or shape, the degree of freedom in layout of the rotating electric machine system and other mounted devices is reduced when the rotating electric machine system is mounted on an object such as a vehicle, etc. For this reason, there is a demand to reduce the size of the rotating electric machine system as much as possible while improving the cooling efficiency.

[0009] The present invention has been made to solve the above-mentioned problems, and aims to provide a rotating electric machine system that has a large degree of freedom in layout when mounted on an object and also has excellent cooling efficiency for the rotating electric machine. [Means for solving the problem]

[0010] In order to achieve the above object, according to one embodiment of the present invention, there is provided a rotating electric machine system in which a rotating electric machine having a stator and a rotor is housed in a substantially cylindrical casing, a heat medium that undergoes a phase change from a liquid phase to a gas phase by removing heat from a cooling medium that has cooled the rotating electric machine within the casing is sealed inside the casing, and a plurality of heat pipes each having a first end inserted into the casing and a second end exposed to the outside of the casing; a radiator connected to the second end for removing heat from the heat medium in the heat pipe and condensing the heat medium; Equipped with the first ends of the plurality of heat pipes are curved in an arc shape along an inner circumferential surface of the casing at at least two locations spaced apart from each other along an axial direction of the casing such that a central angle is 270° or less, and are positioned on an outer circumferential side of the rotating electric machine; There is provided a rotating electric machine system in which the heat sink is disposed near an axial end of the casing. Effect of the Invention

[0011] According to the present invention, a radiator for removing heat from the heat medium in the heat pipe is disposed near the axial end of the casing. This prevents the rotating electric machine system from becoming large in the radial direction outward of the casing. In other words, the rotating electric machine system can be made smaller. This reduces restrictions on the mounting locations of the rotating electric machine system and other devices when mounting the rotating electric machine system on a mounting target. In other words, the freedom of layout of the rotating electric machine system and other devices is improved.

[0012] The casing also contains a cooling medium for cooling the rotating electric machine, and the cooling medium that absorbs heat from the rotating electric machine is quickly cooled by the heat medium in the heat pipe. The heat transferred to the heat medium is quickly dissipated via the radiator. Therefore, the heat medium is quickly ready to cool the cooling medium. Therefore, the rotating electric machine can be efficiently cooled even when the rotor is rotated at high speed. This allows the rotating electric machine system to be miniaturized while improving the output of the rotating electric machine. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic perspective view of a main portion of a rotating electrical machine system according to an embodiment of the present invention; [Diagram 2] 2 is a schematic front view of the inside of a casing constituting the rotating electrical machine system, viewed from the radiator side. FIG. [Diagram 3] 2 is a schematic plan cross-sectional view taken along an axial direction of the rotating electric machine system; [Figure 4] FIG. 2 is a schematic cross-sectional view illustrating the configuration of a heat pipe. [Diagram 5] 11 is a schematic plan view showing a case where a heat pipe is bent inward in the diameter direction of a casing near an axial end of the casing. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A preferred embodiment of the rotating electric machine system according to the present invention will be described in detail below with reference to the accompanying drawings. Note that "left" and "right" in the following particularly refer to the left and right in Fig. 1 and Fig. 3, but this is for convenience to simplify the explanation and make it easier to understand, and does not specify the direction when the rotating electric machine system is actually used. Meanwhile, "down" and "up" particularly refer to the bottom and top in Fig. 1 and Fig. 2, and the bottom and top are the preferred directions when the rotating electric machine system is mounted on a mounting object.

[0015] 1 to 3 are respectively a schematic perspective view of a main part of a rotating electric machine system 10 according to this embodiment, a schematic front view of the inside of a casing 14 as viewed from the radiator 16 side in Fig. 1, and a schematic plan sectional view along the axial direction. This rotating electric machine system 10 includes a rotating electric machine 12, a casing 14 that houses the rotating electric machine 12, a radiator 16, and a first pipe group 18a and a second pipe group 18b that are bridged between the casing 14 and the radiator 16. That is, in this embodiment, there are two sets of pipe groups.

[0016] The rotating electric machine 12 includes a rotor 22 including a rotating shaft 20, and a stator 24 surrounding the outer periphery of the rotor 22. A plurality of permanent magnets 26 are held on the side peripheral wall of the rotating shaft 20 such that the magnetic poles of the surface facing the stator 24 are alternately different. Meanwhile, the stator 24 is configured by covering an electromagnetic steel plate (not shown) with an insulator 28 and winding an electromagnetic coil 30 around the insulator 28. The stator 24 has a substantially annular shape, and the rotor 22 is inserted into a hole formed in the center. Since such a configuration is well known, detailed illustration and description will be omitted.

[0017] The casing 14 includes a main body member 32 having open ends at both ends, a first cap member 34 facing the left opening of the main body member 32, and a second cap member 36 facing the right opening. The left end of the rotating shaft 20 extends from the first cap member 34, and the right end extends from the second cap member 36 so as to be exposed. An axial center line L of the casing 14 passes through the radial center of the casing 14 and the radial center of the rotating shaft 20. Note that the second cap member 36 is omitted in FIG. 2.

[0018] The main body member 32 has a generally cylindrical shape with inner and outer diameters that are generally equal in the longitudinal direction (axial direction) that is the left-right direction in Fig. 3. In this case, the casing 14 is in a recumbent position with the axial direction extending along the horizontal direction. The stator 24 and the permanent magnets 26 of the rotor 22 are housed within the main body member 32 in a recumbent position. Therefore, the rotating shaft 20 of the rotor 22 also extends along the horizontal direction.

[0019] A cooling medium 40 (see FIG. 2) made of a liquid-phase organic material is stored in the casing 14. Since the casing 14 is in a recumbent position, the cooling medium 40 stays in the lower space within the casing 14. A first cap member 34 and a second cap member 36 are provided at both openings of the main body member 32, preventing the cooling medium 40 from leaking from within the casing 14. A specific example of a suitable organic material is a polyhydric alcohol such as ethylene glycol.

[0020] On the inner circumferential surface of the casing 14, first ends 46a, 46b of a first heat pipe 44a and a second heat pipe 44b constituting the first pipe group 18a are arranged at the upper left end. Also, first ends 46c, 46d of a third heat pipe 44c and a fourth heat pipe 44d constituting the second pipe group 18b are arranged at the upper right end. That is, in this embodiment, the first pipe group 18a and the second pipe group 18b are each formed by combining two adjacent heat pipes.

[0021] In the first pipe group 18a, the first end 46a of the first heat pipe 44a is curved in an arc shape along the upper inner circumferential surface of the casing 14 within the casing 14. Here, when the central angle α (see FIG. 2) of the arc formed by the first end 46a is 360°, a part of the first end 46a will be immersed in the cooling medium 40. In order to avoid this, it is preferable to set the central angle α to 270° or less. On the other hand, it is preferable that the central angle α is an obtuse angle. In this case, it is possible to bring the cooling medium 40 condensed by the first heat pipe 44a into contact with the stator 24 over a wide range. In the present embodiment, the central angle α is set to about 180° as an example. In this case, the first end 46a has an approximately semicircular shape.

[0022] The first heat pipe 44a is passed through one of the first dual holes 50a formed on the left front side in FIG. 1 near the left opening in the side peripheral wall of the main body member 32. That is, a portion of the first heat pipe 44a other than the first end 46a extends so as to be exposed from the casing 14. The portion is bent approximately 90° immediately after being exposed from the casing 14, and extends toward the right front side in FIG. 1 of the heat sink 16 while extending approximately parallel to the axial direction of the casing 14. That is, the second end 48a of the first heat pipe 44a faces the heat sink 16.

[0023] The second heat pipe 44b is adjacent to the first heat pipe 44a and has a similar shape to the first heat pipe 44a. That is, the first end 46b of the second heat pipe 44b extends so as to be adjacent to the first end 46a of the first heat pipe 44a inside the casing 14. Therefore, the first ends 46a, 46b of the first heat pipe 44a and the second heat pipe 44b are in approximately the same phase and overlap when viewed from the axial direction of the casing 14 as shown in FIG.

[0024] Further, a portion of the second heat pipe 44b other than the first end 46b is passed through one of the remaining first dual hole 50a and extends so as to be exposed from the casing 14. This portion is bent approximately 90° immediately after being exposed from the casing 14, similar to the first heat pipe 44a, and while remaining adjacent to the first heat pipe 44a, extends approximately parallel to the axial direction of the casing 14 toward the radiator 16. A second end 48b of the second heat pipe 44b faces the radiator 16.

[0025] In the second pipe group 18b, the third heat pipe 44c and the fourth heat pipe 44d are adjacent to each other and have substantially the same shape. The first ends 46c, 46d of the third heat pipe 44c and the fourth heat pipe 44d are also curved in an arc shape along the upper inner circumferential surface of the casing 14 within the casing 14, and the central angle α is preferably set to 270° or less. In the illustrated example, it is about 180°, and the first ends 46c, 46d of the third heat pipe 44c and the fourth heat pipe 44d are substantially semicircular like the first ends 46a, 46b of the first heat pipe 44a and the second heat pipe 44b.

[0026] In this way, the first ends 46a to 46d of the first to fourth heat pipes 44a to 44d all form a semicircular shape with a central angle α of approximately 180° along the upper inner circumferential surface of the main body member 32 that constitutes the casing 14. Therefore, the first ends 46a to 46d of the first to fourth heat pipes 44a to 44d are approximately in phase with each other and overlap when viewed from the axial direction of the casing 14, as shown in FIG.

[0027] It should be noted that first ends 46a, 46b of the first heat pipe 44a and the second heat pipe 44b (first pipe group 18a) are located near the left opening of the main body member 32. In contrast, first ends 46c, 46d of the third heat pipe 44c and the fourth heat pipe 44d (second pipe group 18b) are located near the right opening of the main body member 32. That is, the first ends 46a, 46b of the first pipe group 18a and the first ends 46c, 46d of the second pipe group 18b are spaced apart from each other within the casing 14.

[0028] The third heat pipe 44c and the fourth heat pipe 44d are formed in the vicinity of the right opening in the side peripheral wall of the main body member 32, and are passed through the second dual hole 50b, which has a phase difference of approximately 180° with the first dual hole 50a. That is, the third heat pipe 44c and the fourth heat pipe 44d, except for the first ends 46c and 46d, also extend so as to be exposed from the casing 14. The portions are bent approximately 90° immediately after being exposed from the casing 14, and while maintaining the adjacent state, extend approximately parallel to the axial direction of the casing 14 toward the radiator 16. The second ends 48c and 48d of the third heat pipe 44c and the fourth heat pipe 44d face the right rear side of the radiator 16 in FIG. 1.

[0029] The heat sink 16 has, for example, a plate fin 54 made of an aluminum alloy and a brazing sheet 56 joined to the curved top of the plate fin 54, and the plate fin 54 and the brazing sheet 56 are curved 360° to form a substantially annular shape. An inner end ring 58 is disposed on the innermost periphery, and an outer end ring 60 is disposed on the outer periphery. A third dual hole 62a and a fourth dual hole 62b are formed by removing a part of the plate fin 54 and the brazing sheet 56. The second ends 48a, 48b of the first heat pipe 44a and the second heat pipe 44b are fitted and joined to the third dual hole 62a on the front right side in FIG. 1. Meanwhile, the second ends 48c, 48d of the third heat pipe 44c and the fourth heat pipe 44d are fitted into the fourth dual hole 62b, which is disposed at a phase difference of approximately 180° with respect to the third dual hole 62a.

[0030] By the above fitting, the second ends 48a to 48d of the first to fourth heat pipes 44a to 44d are connected to the radiator 16. The radiator 16 may be supported by the casing 14 via a stay or the like (not shown).

[0031] In this case, the radiator 16 configured in this manner is disposed near the right end, which is one of the axial ends of the casing 14. A rotating shaft 20 passes through the radiator 16. The axial center line L of the casing 14 passes through the radial center O of the radiator 16. That is, the radial center of the casing 14, the radial center of the rotating shaft 20, and the radial center O of the radiator 16 are aligned on the axial center line L. As can be seen from this, the radial center O of the radiator 16 overlaps with the radial center of the casing 14 when viewed from the axial direction of the casing 14. That is, the radiators 16 are aligned in the axial direction of the casing 14.

[0032] The inner diameter of the heat sink 16 (the inner diameter of the inner end ring 58) is approximately equal to the outer diameter of the casing 14. Moreover, the outer diameter of the heat sink 16 (the outer diameter of the outer end ring 60) is set to be slightly larger than the outer diameter of the casing 14. The difference obtained by subtracting the inner diameter from the outer diameter of the heat sink 16 is slightly larger than the sum of the diameters of the adjacent second ends 48a, 48b, or the adjacent second ends 48c, 48d.

[0033] Here, the configuration of the first heat pipe 44a to the fourth heat pipe 44d will be briefly described with reference to the first heat pipe 44a shown in FIG. 4. As shown in FIG. 4, a closed space 80 is formed in the first heat pipe 44a along the longitudinal direction. A working fluid 82, which is a heat medium, is stored in the closed space 80. A wick 84 is provided in the first heat pipe 44a along the longitudinal direction, and the closed space 80 is divided by the wick 84 to form a main passage 86. The working fluid 82 is generally water, but may be other liquids. An appropriate amount of the working fluid 82 is sealed in the closed space 80, and does not fill the closed space 80.

[0034] FIG. 4 shows a state where the cooling medium 40 in gas phase (vapor 90) comes into contact with the first end 46a of the first heat pipe 44a. With this contact, heat is transferred from the vapor 90 of the cooling medium 40 to the working liquid 82. As a result, the working liquid 82 is vaporized and becomes the vapor 92. The vapor 92 moves along the main passage 86 away from the first end 46a, which is relatively high temperature, that is, toward the second end 48a in this case. Meanwhile, at the second end 48a, heat is taken from the vapor 92 by heat radiation from the radiator 16 (see FIGS. 1 and 3). As a result, the vapor 92 condenses and returns to the working liquid 82 in liquid phase. The working liquid 82 in liquid phase is returned toward the first end 46a through the wick 84 by capillary force.

[0035] Needless to say, the above-mentioned configuration of the first heat pipe 44a and the movement of the working fluid 82 or vapor 92 are similarly applied to the second heat pipe 44b to the fourth heat pipe 44d. As shown in Figs. 1 to 3, in this embodiment, the first ends 46a to 46d of the first heat pipe 44a to the fourth heat pipe 44d inserted into the casing 14 are curved in an arc shape. On the other hand, the portions exposed to the outside of the casing 14, including the second ends 48a to 48d connected to the radiator 16, extend substantially linearly.

[0036] The rotating electrical machine system 10 according to this embodiment is basically configured as described above. Next, the effects of the system will be described.

[0037] The rotating electric machine system 10 is mounted on an object such as a vehicle or an airplane, and is incorporated into, for example, an internal combustion engine, and a predetermined member (not shown) is attached to the tip of a rotating shaft 20 that passes through a radiator 16. Here, the rotating electric machine system 10 is mounted on the object with the rotating shaft 20 extending along the horizontal direction. Therefore, the rotating electric machine system 10 is in a recumbent position with the casing 14 extending along the horizontal direction.

[0038] At this time, the casing 14 is oriented so that the first ends 46a-46d of the first to fourth heat pipes 44a-44d face upward. In this orientation, the liquid-phase cooling medium 40 stored in advance in the casing 14 remains in the lower space of the casing 14 (see FIG. 2). Therefore, the electromagnetic coil 30 located below is immersed in the cooling medium 40. The cooling medium 40 does not come into contact with the first ends 46a-46d of the first to fourth heat pipes 44a-44d.

[0039] As described above, in the rotating electric machine system 10, the radiators 16 are arranged in parallel along the axial direction of the casing 14. Therefore, the radiators 16 and the casing 14 are close to each other. In addition, in the rotating electric machine system 10, the radiators 16 are arranged at the axial end of the casing 14, and the outer diameter of the radiators 16 is slightly larger than the outer diameter of the casing 14. Moreover, the portions of the first heat pipe 44a to the fourth heat pipe 44d exposed from the casing 14 extend substantially parallel to the axial direction of the casing 14. In addition, it is not necessary to gather the first ends 46a to 46d and the second ends 48a to 48d of the first heat pipe 44a to the fourth heat pipe 44d on the radially outer side of the casing 14 to provide a heat dissipation section. For the above reasons, the rotating electric machine system 10 is prevented from becoming large along the radially outer side of the casing 14.

[0040] This allows the rotating electric machine system 10 to be made smaller. In addition, because the rotating electric machine system 10 is small, there are fewer restrictions on the placement of the rotating electric machine system 10 and other devices mounted on the mounting target. In other words, there is greater freedom in the layout of the rotating electric machine system 10 and other devices. This also increases the freedom in the design of the mounting target. In addition, because the heat sink 16 is substantially annular (hollow), there is also the advantage that it is lighter than a solid heat sink that is circular, rectangular, or the like.

[0041] The rotating electric machine system 10 is operated as, for example, a generator. In this case, the members attached to the rotating shaft 20 are urged to rotate. Accordingly, the rotating shaft 20, and therefore the rotor 22, rotate integrally with the members. Since the radiator 16 has an annular shape, the rotating shaft 20 can pass through the radiator 16. Therefore, by disposing the radiator 16 at the axial end of the casing 14, the rotating shaft 20 is prevented from interfering with the radiator 16. This prevents the rotor 22 from becoming unable to rotate.

[0042] As the rotating shaft 20 rotates, the multiple permanent magnets 26 held by the rotating shaft 20 rotate. Therefore, the permanent magnets 26 with different magnetic poles alternately face the electromagnetic coils 30 of the stator 24. This induces a current in the electromagnetic coils 30, causing the rotating electric machine 12 to generate electric power. The electric power is taken out from terminals (not shown) and used as electric energy to energize an external load.

[0043] In this process, the electromagnetic coil 30 takes on heat. In other words, the electromagnetic coil 30 becomes a heat source. Here, the liquid-phase cooling medium 40 is in contact with the electromagnetic coil 30 located below. Therefore, the lower electromagnetic coil 30 is cooled by the cooling medium 40. In other words, the heat of a part of the electromagnetic coil 30 is absorbed by the cooling medium 40. The cooling medium 40 that absorbs the heat from the electromagnetic coil 30 vaporizes and becomes steam 90 (gas phase).

[0044] The steam 90 rises inside the casing 14 and comes into contact with the first ends 46a to 46d of the first to fourth heat pipes 44a to 44d that are curved along the upper inner circumferential surface of the casing 14. At these first ends 46a to 46d, the working fluid 82 (see FIG. 4) sealed inside as a heat medium absorbs heat from the gas-phase cooling medium 40. As a result, the steam 90 is cooled and liquefied. That is, the cooling medium 40 condenses and returns to the liquid phase. The liquid-phase cooling medium 40 drips inside the casing 14 as droplets 94, as shown in FIG. 2.

[0045] The liquid droplets 94 come into contact with, for example, the electromagnetic coil 30 located above. This cools the electromagnetic coil 30 located above. Some of the liquid droplets 94 evaporate, rise as vapor 90, and then come into contact with the first ends 46a to 46d of the first heat pipe 44a to fourth heat pipe 44d. Note that most of the liquid droplets 94 that come into contact with the insulator 28, whose temperature has not risen relatively, reach the lower space of the casing 14 without evaporating, and cool the electromagnetic coil 30 located below. In either case, the above-mentioned evaporation and condensation are repeated thereafter.

[0046] In the casing 14, the first ends 46a, 46b of the first pipe group 18a and the first ends 46c, 46d of the second pipe group 18b are spaced apart from each other (see FIG. 1 and FIG. 3). Therefore, even if the vapor 90 of the cooling medium 40 is diffused over a wide range, the vapor 90 is cooled by the working fluid 82 in the first ends 46a to 46d. Therefore, the cooling medium 40 can be efficiently returned to the liquid phase. This also causes droplets 94 to drip over a wide range in the casing 14. Therefore, the upper electromagnetic coil 30 that is not immersed in the liquid cooling medium 40 is sufficiently cooled over a wide range. That is, by separating the first ends 46a, 46b of the first pipe group 18a and the first ends 46c, 46d of the second pipe group 18b from each other, the electromagnetic coil 30 can be efficiently cooled.

[0047] Therefore, even when the rotor 22 is rotated at high speed, the amount of magnetic flux in the permanent magnets 26 is prevented from being reduced due to heat generation. This makes it possible to improve the output while miniaturizing the rotating electric machine system 10. Furthermore, since the electromagnetic coil 30 is efficiently cooled, the durability of the electromagnetic coil 30 is improved. In other words, the durability of the rotating electric machine 12 can also be improved.

[0048] 4, vapor 92 of working fluid 82 generated inside the first ends 46a-46d moves along the main passage 86 toward the second ends 48a-48d. Because the second ends 48a-48d are exposed to the outside of the casing 14, the vapor 92 is exhausted to the outside of the casing 14 during this movement. Because the outside of the casing 14 is at a lower temperature than the inside of the casing 14, the vapor 92 can be cooled on the way to the second ends 48a-48d.

[0049] The second ends 48a to 48d are connected to the radiator 16 (see FIG. 1 and FIG. 3). The heat of the steam 92 that reaches the second ends 48a to 48d is dissipated to the atmosphere through the plate fins 54 (see FIG. 1) that constitute the radiator 16. Here, since the inner and outer diameters of the radiator 16 are sufficiently large compared to the outer diameter of the second ends 48a to 48d, the surface area of ​​the plate fins 54 can be made as large as possible. The steam 92 is also cooled before reaching the second ends 48a to 48d as described above. Due to the above factors, the heat of the steam 92 is efficiently taken away in the radiator 16, and the steam 92 is quickly cooled and condensed. That is, as shown in FIG. 4, the steam 92 returns to the liquid phase working fluid 82. The working fluid 82 flows back along the wicks 84 in the first heat pipe 44a to the fourth heat pipe 44d to the first ends 46a to 46d.

[0050] Then, in the first ends 46a-46d, the liquid-phase working fluid 82 absorbs heat from the gas-phase cooling medium 40 (steam 90) and vaporizes, changing into steam 92. Thereafter, the movement of the steam 92 to the second ends 48a-48d, the condensation of the steam 92, and the return flow of the liquid-phase working fluid 82 to the first ends 46a-46d are repeated. Therefore, the evaporation and condensation of the cooling medium 40 are also repeated, thereby continuing the cooling of the rotating electric machine 12.

[0051] The present invention is not particularly limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention.

[0052] For example, the number of heat pipes can be set appropriately depending on the size of the rotating electric machine 12 and the casing 14. When the rotating electric machine 12 and the casing 14 are large, the first pipe group 18a and the second pipe group 18b may include three or more heat pipes. Alternatively, the first ends of a plurality of heat pipes (for example, the first ends 46a to 46d of the first heat pipe 44a to the fourth heat pipe 44d) may be arranged so as to be spaced apart from each other within the casing 14. There is also no particular need to make the central angles of the first ends coincident with each other.

[0053] In this way, in the present invention, the number of heat pipes and their locations can be set as desired, which increases the degree of freedom in designing the rotating electrical machine system 10.

[0054] 5, the second ends 48a-48d of the first heat pipe 44a-fourth heat pipe 44d may be bent radially inwardly of the casing 14 near the right end of the casing 14, and then bent again to extend linearly toward the radiator 16. In this case, the inner and outer diameters of the radiator 16 can be made even smaller.

[0055] Furthermore, in the heat sink 16, corrugated fins may be used in place of the plate fins 54.

[0056] Furthermore, it goes without saying that the rotating electric machine 12 may function as a motor. [Explanation of symbols]

[0057] 10... Rotating electric machine system 12... Rotating electric machine 14... Casing 16... Heat sink 18a, 18b...Pipe group 20...Rotating shaft 22... rotor 24... stator 26... permanent magnet 30... electromagnetic coil 32...Main body member 40...Cooling medium 44a to 44d: Heat pipes 46a to 46d: First ends 48a~48d...Second end 54...Plate fin 56...Brazing sheet 82...Hydraulic fluid 84…Wick 86…Main Passage 90...coolant vapor 92...working fluid vapor 94...droplet

Claims

1. In a rotating electric machine system in which an inner rotor type rotating electric machine having a stator and a rotor is housed in a substantially cylindrical casing, The casing is mounted on a mounting object in a lying position with an axial direction facing horizontally, a cooling medium sealed within the casing, capable of changing phase between a liquid phase and a gas phase, and in which a lower portion of the stator is immersed when in the liquid phase; a heat medium that undergoes a phase change from a liquid phase to a gas phase by removing heat from the cooling medium that has changed into a gas phase by cooling the rotating electric machine within the casing is enclosed in the casing, and a plurality of heat pipes each having a first end inserted into the casing and a second end exposed to the outside of the casing; a radiator connected to the second end for removing heat from the heat medium in the heat pipe and condensing the heat medium; Equipped with the first ends of the plurality of heat pipes are curved in an arc shape along the circumferential direction of the inner circumferential surface of the casing at at least two locations spaced from each other along the axial direction of the casing at positions not immersed in the liquid phase cooling medium, with a central angle of 270° or less, and are positioned radially inward from the inner circumferential surface of the casing and radially outward from the rotating electric machine in a state of not contacting the rotating electric machine, and are disposed above the stator in a state exposed to the outside of the rotating electric machine so that the cooling medium that liquefies and drops can come into contact with the stator, The radiator is disposed near an axial end of the casing.

2. The rotating electrical machine system according to claim 1 , wherein the first end is substantially semicircular in shape.

3. 3. A rotating electric system according to claim 1 or 2, wherein the heat pipe has a portion that is curved in an arc shape within the casing, and a portion that extends from a side wall of the casing to the outside of the casing and extends linearly to the radiator approximately parallel to the axial direction of the casing.

4. In the rotating electric system according to any one of claims 1 to 3, when a combination of two or more of the heat pipes arranged adjacent to each other is regarded as one pipe group, the rotating electric system has at least two sets of pipe groups spaced apart from each other.

5. 5. The rotating electrical machine system according to claim 1, wherein the heat sink is substantially annular.

6. 6. The rotating electrical machine system according to claim 5, wherein a radial center of said casing and a radial center of said radiator substantially overlap with each other.

7. 7. The rotating electric machine system according to claim 1, wherein the second end of the heat pipe is a straight portion that extends linearly from the casing toward the radiator.

8. 8. The rotating electric machine system according to claim 1, wherein the rotor has a rotating shaft, and the rotating shaft is not immersed in the liquid phase cooling medium inside the casing.

9. In a rotating electric machine system in which an inner rotor type rotating electric machine having a stator and a rotor is housed in a substantially cylindrical casing, a liquid-phase cooling medium sealed within the casing, capable of changing phase between a liquid phase and a gas phase, and in which a lower portion of the rotating electric machine is immersed; a heat pipe in which a heat medium is sealed in the casing, the heat medium undergoing a phase change from a liquid phase to a gas phase by removing heat from the cooling medium which has changed into a gas phase after cooling the rotating electric machine within the casing, the heat pipe having a heat receiving portion inserted into the casing and disposed at a position not immersed in the cooling medium in the liquid phase, and a heat dissipating portion exposed to the outside of the casing; a radiator connected to the heat dissipation unit outside the casing for removing heat from the heat medium in the heat pipe and condensing the heat medium; Equipped with A rotating electric machine system in which the cooling medium in the gas phase within the casing changes to a liquid phase by coming into contact with the heat receiving part that is located radially inward from the inner surface of the casing and radially outward from the rotating electric machine while being exposed to the outside of the rotating electric machine and not in contact with the rotating electric machine, and then cools the rotating electric machine and repeats the cycle of changing to the gas phase.

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