rotating electrical machines

Abstract

The present invention makes it possible to obtain a rotary electric machine (100) whereby unevenness in cooling performance in the interior of a stator coil (90) can be reduced and the stator coil (90) and a stator core (91) can be efficiently cooled. The rotary electric machine (100) is provided with: a stator core (91) having a plurality of slots (96); and a stator coil (90) that is attached to the stator core (91) and includes a plurality of heat pipes (95) arranged within the plurality of slots (96) and having a refrigerant sealed therein, and stator coil wires (92) arranged within the slots (96).

Description

[Technical Field]

[0001] The present application relates to a rotating electric machine. [Background technology]

[0002] Conventionally, so-called rotating electric machines include, for example, AC generators, motors, and vehicle drive devices, and are equipped with a casing with a cooling flow discharge window opened in the peripheral wall, a rotor that is rotatably held within the casing, and a stator that is positioned opposite the outer periphery of the rotor and fixed to the casing, and the rotating electric machine is cooled by sucking in fluid from the casing intake part, and is used for the purpose of generating electricity or driving. BACKGROUND ART Conventionally, a rotating electric machine has been proposed in which the cooling performance of a stator coil is improved by forming the entire length (over the entire length) of a so-called concentrated winding stator coil with a heat pipe (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-126253 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional rotating electric machine disclosed in the aforementioned Patent Document 1, the entire stator coil is formed from a heat pipe, which causes the volatile liquid in the heat pipe to become locally biased, resulting in uneven cooling performance inside the stator coil.

[0005] The present application discloses a technology for solving the above-mentioned problems, and aims to provide a rotating electric machine that can prevent the volatile liquid inside the heat pipe from becoming locally concentrated, reduce uneven heat inside the stator coil, and thereby reduce uneven cooling performance, thereby efficiently cooling the stator coil and stator core. [Means for solving the problem]

[0006] The rotating electric machine disclosed in the present application includes a stator core having a plurality of slots and a stator coil attached to the stator core. The stator coil has a plurality of heat pipes filled with a refrigerant that transports heat by condensation or evaporation, and a stator coil wire that does not contain a refrigerant, and one of the plurality of heat pipes arranged in a certain slot of the plurality of slots and the stator coil wire arranged in another slot of the plurality of slots are connected in series so as to be electrically connected. This is what happened. [Effects of the Invention]

[0007] According to the rotating electric machine disclosed in the present application, it is possible to prevent the volatile liquid inside the heat pipe from becoming locally concentrated, and reduce uneven heat inside the stator coil, thereby reducing uneven cooling performance, and as a result, it is possible to obtain a rotating electric machine that can efficiently cool the stator coil and stator core. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a cross-sectional view showing a rotating electric machine according to a first embodiment. [Figure 1B] 1 is a cross-sectional view showing a rotating electric machine according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a stator of the rotating electric machine shown in FIGS. 1A and 1B. [Figure 3] FIG. 2 is a cross-sectional view showing a stator coil according to the first embodiment. [Figure 4] FIG. 10 is a cross-sectional view showing a stator coil according to a second embodiment. [Figure 5] FIG. 11 is a cross-sectional view showing a heat pipe of a stator coil according to a third embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing a heat pipe of a stator coil according to a fourth embodiment. [Figure 7] FIG. 10 is a radial cross-sectional view showing a stator according to a fifth embodiment. [Figure 8] FIG. 13 is a radial cross-sectional view showing a stator according to a sixth embodiment. [Figure 9] FIG. 13 is a cross-sectional view showing a stator coil according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present application relates to a technology that can be applied to rotating electric machines in general, such as on-board AC generators, motors, on-board drive devices, electronic device-integrated rotating electric machines, and induction motors. The rotating electrical machine according to the first embodiment will be described below with reference to the drawings. In addition, the same reference numerals in each drawing indicate the same or equivalent parts.

[0010] Embodiment 1 Fig. 1A is a cross-sectional view showing a rotating electric machine according to embodiment 1. In embodiment 1, as shown in Fig. 1A, an in-vehicle rotating electric machine 100 will be described as an example. As shown in FIG. 1A, the rotating electric machine 100 has a housing 1 consisting of a roughly bowl-shaped front housing 2 and a rear housing 3, and is equipped with a shaft 34 rotatably supported by the housing 1 via a pair of bearings 33, a rotor 8 that rotates integrally with the shaft 34, and a stator 9 arranged opposite the outer periphery of the rotor 8.

[0011] A pair of slip rings 10 that supply current to rotor 8 are fixed to an extending portion of shaft 34 that extends to the rear side of housing 1. A pair of sliding brushes 11 and a brush holder 17 that houses these brushes 11 are provided on the surface of each slip ring 10. The motor further includes a voltage regulator 12 that is adjacent to these brushes 11 and adjusts the magnitude of the AC voltage generated in stator 9, a rectifier 13 that rectifies the AC voltage generated in stator 9 to a DC voltage, a heat sink 18, a connector 20 that inputs and outputs signals between voltage regulator 12 and an external device (not shown), and a protective cover 27 that covers brush holder 17 and rectifier 13.

[0012] The rotor 8 is a Lundell type rotor, and is equipped with a field winding 81 in which insulated copper wire is wound cylindrically and concentrically, and in which an excitation current flows to generate magnetic flux, and a field core 82 in which magnetic poles are formed by the generated magnetic flux and which is arranged to cover the field winding 81, and each field core 82 has six, eight, or ten or more claws, the number of which is a multiple of two, and cooling fans 83 attached by welding or the like to both end faces in the axial direction a, which draw outside air into the rotating electric machine 100 as the rotor 8 rotates and cools and discharges the air to the components inside the rotating electric machine 100.

[0013] The rotor 8 is formed by a field winding 81 and a field core 82 and is provided with a ventilation passage for cooling the field winding 81, and the field winding 81 is cooled by flowing a fluid in the axial direction a using the rotor 8 and a cooling fan 83. A magnet may be installed in the rotor 8 to increase output, and output can be increased effectively by installing a magnet between the claws of the field core 82 in particular. 1A, the electronic components shown on the left side of the rear housing 3 are an example, and may be a rotating electric machine integrated with electronic devices including a power conversion unit. For example, as shown in FIG. 1B, a rotating electric machine 100 having a control device 14 on the left side of the rear housing 3 may be used, and the structure of the rotor 8 is not limited to the Lundell type rotor described above.

[0014] The cooling fan 83 includes a main plate 832, a plurality of arm plates 833 extending from the main plate 832, and a plurality of blades 834, and is attached to a rotating object, such as the rotor 8 of the rotating electric machine 100. When main plate 832 rotates, it generates air that is discharged outward along blades 834, and the air that flows into the center of main plate 832 acts as a cooling fan that discharges it toward the outer periphery. The coil ends are cooled by the air discharged toward the outer periphery by cooling fan 83. Here, the coil ends refer to the stator coil portions on one and the other ends of stator core 91 that extend axially outward from stator core 91.

[0015] Fig. 2 is a perspective view showing the stator of the rotating electric machine shown in Fig. 1A and Fig. 1B. Fig. 3 is an axial cross-sectional view showing the stator coil of the stator shown in Fig. 2, showing a part of the heat pipe 95 of the stator coil 90. As shown in FIGS. 2 and 3, the stator coil 90 is wound around a stator core 91 with a stator coil wire 92, a heat pipe 95, and a stator coil connecting member 94 connected to each other. The stator coil wire 92 and the stator coil connecting material 94 are, for example, copper wire. For the sake of explanation, the stator coil wire 92 and the stator coil connecting material 94 are each given their own names, but they may be the same material. The stator coil wire 92, the heat pipe 95, and the stator coil connecting material 94 are each rod-shaped. The heat pipe 95 has a space inside the stator coil wire 92 in which a refrigerant is sealed. In other words, the stator coil 90 has a cylindrical heat pipe 95. The heat pipe 95 receives heat from a heat-generating component, and the refrigerant stored inside the heat pipe 95 evaporates or condenses, transporting the heat inside the heat pipe 95 and cooling the heat-generating component.

[0016] 3, a heat pipe 95 and a stator coil wire 92 that are adjacent to each other across the stator core 91 are connected in series by a stator coil connecting material 94, and the stator coil wire 92 and the heat pipe 95 are further connected in series by a stator coil connecting material 94. An insulator 93 is provided between the stator core 91 and the stator coil wire 92. 3, the upper side of the page will be referred to as "up," the lower side as "down," the left side as "left," and the right side as "right." The heat pipe 95 and the stator coil wire 92, which is located to the right of the stator core 91, are connected at their lower ends by a stator coil connecting material 94. The stator coil wire 92, whose lower end is connected to the heat pipe 95, has its upper end connected to the upper end of the heat pipe 95 two stops to the right by a stator coil connecting material 94.

[0017] In this way, the heat pipes 95 and the stator coil wires 92 are connected by the stator coil connecting material 94 to form part of the stator coil 90. One end and the other end of the stator coil connecting material 94 are fixed by welding to the stator coil wires 92 or the heat pipes 95, respectively. Once fixed, the stator coil 90 is formed into a single stator coil 90, which is wound around the stator core 91. The heat pipe 95 contacts the stator core 91 with an insulator 93 sandwiched therebetween, so that heat from the stator core 91 is transferred to the refrigerant in the heat pipe 95. The heat pipe 95 is part of the stator coil 90, and is arranged along the stator core 91 in a slot 96 (a narrow gap between adjacent stator cores 91).

[0018] The heat pipes 95 are provided along the axial direction a of the shaft 34 from one end to the other end of the stator core 91. As shown in Fig. 3, the heat pipes 95 are arranged at two or more positions in the stator coil 90. For example, the heat pipe 95 arranged in a certain slot 96 is connected by a stator coil connecting material 94 to a stator coil wire 92 arranged in a slot 96 adjacent to the slot 96 or in another slot 96, and the stator coil wire 92 is further connected to another heat pipe 95 by a stator coil connecting material 94 to form the stator coil 90.

[0019] That is, the heat pipes 95 are distributed in multiple locations within the stator coil 90. If the stator coil 90 has long heat pipes 95, the refrigerant inside the heat pipes 95 may become unevenly distributed, resulting in a decrease in cooling performance. For example, if the heat pipes 95 are the entire length of the stator coil 90, the refrigerant inside the heat pipes 95 may become unevenly distributed. As a result, local temperature increases may occur in the stator core 91, and cooling performance may become uneven within the stator coil 90. For this reason, the multiple heat pipes 95 are distributed in multiple locations. Furthermore, the stator coil wires 92 connected to the multiple heat pipes 95 are arranged within the slots 96 along the stator core 91, similar to the heat pipes 95. The multiple heat pipes 95 are each connected to the stator coil wires 92 to form the stator coil 90. That is, the stator coil 90 has heat pipes 95 in multiple locations.

[0020] Each heat pipe 95 receives heat from the stator core 91, which is in contact with the heat pipe 95 with an insulator 93 sandwiched therebetween, and transports the heat to one end and the other end of the stator core 91. In other words, the heat pipes 95 promote heat transfer in the axial direction a. A fluid (cooling air) flows into one end and the other end of the stator core 91 from openings provided in the housing 1, and the fluid (cooling air) cools the coil ends of the stator coil 90, enabling efficient cooling. In other words, the coil ends of the stator coil 90 are cooled by the air blown in the centrifugal direction by the cooling fan 83, so transporting heat in the axial direction a by the heat pipes 95 allows efficient cooling of the stator coil 90 and the stator core 91. In the rotating electric machine 100 of the first embodiment, the stator coil 90 can be cooled at multiple points in the stator coil 90, and heat is dispersed, thereby reducing unevenness in the cooling performance of the stator coil 90.

[0021] As described above, the rotating electric machine 100 includes a rotor 8 that rotates integrally with a shaft 34, a stator 9 that is supported on the outer periphery of the rotor 8 and has a stator core 91 and a stator coil 90, and a housing 1 that supports the shaft 34 with bearings 33, houses the stator 9 and rotor 8, and has an opening on the outer periphery of the stator 9. The stator coil 90 has a plurality of heat pipes 95 and stator coil wire 92 (portions that are not heat pipes 95). Furthermore, the rotating electric machine 100 of embodiment 1 includes a stator core 91 having a plurality of slots 96, a plurality of heat pipes 95 arranged in the plurality of slots 96 and having a refrigerant sealed inside, and a stator coil 90 having stator coil wire 92 arranged in the slots 96 and attached to the stator core 91.

[0022] This makes it possible to efficiently transport the heat generated inside the stator 9, reducing uneven heat distribution inside the stator coil 90 and efficiently cooling both the stator core 91 and the stator coil 90. In particular, the higher the voltage applied to the stator coil 90, the greater the heat generated by the stator core 91, and therefore the greater the effect of improving efficiency due to the temperature reduction. In addition, the heat pipe 95 is arranged in the slot 96 along the axial direction a of the stator core 91 from one end to the other end, and the heat pipe 95 is connected in series to the stator coil wire 92 by a stator coil connecting member 94 provided on one or the other end of the stator core 91.

[0023] As described above, the stator coil wire 92 and the heat pipe 95 may be connected adjacent to each other across the stator core 91, or may be connected at intervals of one stator core 91 in the circumferential direction, or may be connected at intervals of two or more stator cores 91 in the circumferential direction, or may be connected at different positions in the radial direction b. The stator coil wire 92 and the stator coil connecting material 94 may be connected in series in any manner as long as current is applied, for example, by welding, electrically conductive adhesive, crimping, or swaging. For example, the heat pipe 95 may be disposed in the slot 96 and the respective wires may be connected by welding. Similarly to the above, the stator coil connecting material 94 and the heat pipe 95 may be connected in series in any manner as long as current is applied.

[0024] 3 shows the stator coil wire material 92 and the stator coil linking material 94 as separate pieces, but the stator coil wire material 92 and the stator coil linking material 94 may be formed from a single piece of wire by bending the coil wire material into an L shape. Also, by increasing the number of times the coil wire material is bent, multiple stator coil wire materials 92 and multiple stator coil linking materials 94 may be formed from a single piece of wire. Forming them in this way makes it possible to reduce the number of connection points, which not only facilitates manufacturability but also reduces manufacturing costs.

[0025] The stator coil 90 may be formed with three or more heat pipes 95 connected in series, as long as not all of the stator coil 90 are connected in series. Also, the stator coil wire 92 may be connected using heat pipes 95 instead of the stator coil connecting members 94. The stator coil wire 92 or the heat pipe 95 may have a coating for insulation, and to further improve insulation, an insulator may be provided between the stator coil wire 92 or the heat pipe 95 and the stator core 91. Also, the outer shape of the stator coil wire 92 and the heat pipe 95 may be approximately circular, elliptical, or rectangular with rounded corners.

[0026] This makes it possible to efficiently transport the heat generated inside the stator 9, improving efficiency and increasing output by reducing the temperature of the stator 9. In particular, the higher the voltage applied to the stator coil 90, the greater the amount of heat generated by the stator core 91, and the greater the efficiency improvement effect due to the temperature reduction.

[0027] Embodiment 2 Fig. 4 is an axial cross-sectional view showing a stator coil according to embodiment 2, illustrating a portion of a heat pipe 95 of the stator coil 90. In Fig. 4, components having the same reference numerals as those used to explain the axial cross-sectional view of the stator coil 90 of embodiment 1 indicate the same or corresponding configurations, and their description will be omitted. In the above-described embodiment 1, a substantially linear heat pipe 95 was used to form the stator coil 90, but in the stator coil 90 according to embodiment 2, as shown in Fig. 4, the heat pipe 95 is bent at least once and connected to the stator coil wire 92 or the stator coil connecting member 94.

[0028] In the second embodiment, the stator coil 90 has a U-shaped heat pipe 95 sandwiching the stator core 91. As shown in FIG. 4, the heat pipe 95 is provided not only in the slots 96 but also at the axial end of the stator core 91. In the second embodiment, as shown in FIG. 4, the heat pipe 95 is bent twice. This not only reduces the number of connection points, but also eliminates the need to inject volatile liquid after connecting one end of the heat pipe 95. In FIG. 4, this facilitates injection into the heat pipe 95 from one direction below the plane of the page, thereby facilitating manufacturability. After injecting the volatile liquid, the connection between the slots 96 of the heat pipe 95 may be crushed to separate the flow path within the heat pipe 95.

[0029] Embodiment 3 Fig. 5 is a cross-sectional view showing a heat pipe of a stator coil according to embodiment 3. As shown in Fig. 5, heat pipe 95 of stator coil 90 according to embodiment 3 has concave and convex portions 951 therein. In this way, by providing uneven portions 951 on the inner surface of the heat pipe 95, it is possible to promote the flow of volatile liquid due to capillary action inside the heat pipe 95, and it is possible to increase the heat transport capacity of the heat pipe 95.

[0030] Embodiment 4 Fig. 6 is a cross-sectional view showing a heat pipe for a stator coil according to embodiment 4. As shown in Fig. 6, a spiral uneven pattern 952 or a mesh uneven pattern may be set inside heat pipe 95, or a porous material or mesh may be formed inside heat pipe 95 to achieve the same effect. In this way, by providing the inner surface of the heat pipe 95 with a spiral-shaped uneven pattern 952 or a mesh-like uneven pattern, it is possible to promote the flow of volatile liquid due to capillary action inside the heat pipe 95, and it is possible to increase the heat transport capacity of the heat pipe 95.

[0031] Embodiment 5. Fig. 7 is a radial cross-sectional view showing a stator according to embodiment 5. As shown in Fig. 7, in stator 9 according to embodiment 5, heat pipes 95 are arranged at least partially in the circumferential direction. In addition, in stator 9 according to embodiment 5, when heat pipes 95 are arranged in the circumferential direction, the heat pipes 95 are arranged so that the radial positions of the heat pipes 95 in adjacent slots 96 are different. In this way, by arranging the heat pipes 95 at different radial positions in adjacent slots 96, not only can the heat pipes 95 be effectively arranged in areas of high heat density within the stator 9, but it also becomes possible to efficiently cool both the stator core 91 and the stator coil 90, which not only enables improved efficiency, increased output, and reduced wind noise, but also reduces starting torque, cogging torque, and electromagnetic noise due to the difference between the wire and the heat pipes 95.

[0032] Embodiment 6 Fig. 8 is a radial cross-sectional view showing a stator according to embodiment 6. As shown in Fig. 8, in stator 9 according to embodiment 6, some of the heat pipes 95 are provided at the outermost radial position of stator 9. Furthermore, for example, when multiple heat pipes 95 are provided in the same slot 96, some of them may be set to be arranged on the inner radial side. In this way, by providing the heat pipe 95 at the outermost diameter of the stator core 91 within the slot 96, not only can the heat pipe 95 be effectively positioned at a location within the stator 9 where heat density is high, but it also becomes possible to efficiently cool both the stator core 91 and the stator coil 90, which not only improves efficiency, increases output, and reduces wind noise, but also reduces starting torque, cogging torque, and electromagnetic noise due to the difference between the wire and the heat pipe 95.

[0033] Embodiment 7 Fig. 9 is a radial cross-sectional view showing a stator coil according to embodiment 7. More specifically, Fig. 9 shows a radial cross-section of stator coil wire 92 and heat pipe 95 arranged in slots 96 between stator cores 91. As shown in Fig. 9, in the stator coil 90 according to embodiment 7, the heat pipe 95 provided in a part of the stator coil 90 may have a circumferential length and a radial length that are different from those of the stator coil wire 92. For example, let the radial length of the heat pipe 95 provided on the outermost diameter of the stator 9 be the radial length t, the circumferential length of the heat pipe 95 provided on the outermost diameter of the stator 9 be the circumferential length s, the radial length of the stator coil wire 92 be the radial length t0, and the circumferential length of the stator coil wire 92 be the circumferential length s0. The circumferential length s of the heat pipe 95 is set to be approximately equal to the circumferential length s0 of the stator coil wire 92, while the radial length t of the heat pipe 95 is set to be t >= t0. In other words, the radial length t of the heat pipe 95 provided on the outer diameter side of the stator 9, for example, on the outermost diameter here, is set to be equal to or greater than the radial length t0 of the stator coil wire 92. Setting the conductor cross-sectional areas of the stator coil wire 92 and the heat pipe 95 to be equal to each other effectively improves cooling performance, thereby improving the efficiency and increasing the output of the rotating electric machine 100.

[0034] Furthermore, when the radial length of the heat pipe 95 arranged on the inner diameter side of the stator 9 is taken as radial length t1, the radial length t1 of the heat pipe 95 arranged on the inner diameter side of the stator 9 may be set so that t1<=t0. Note that the circumferential length of the heat pipe 95 arranged on the inner diameter side of the stator 9 is approximately equal to the circumferential length s0 of the stator coil wire 92. In this way, by setting the radial length t1 of the heat pipe 95 provided on the inner diameter side to be equal to or less than the radial length t0 of the stator coil wire 92 while keeping the circumferential length approximately the same, it is possible to reduce the number of hollow spaces caused by the heat pipe 95 in the area of ​​high magnetic flux density on the inner diameter side of the stator 9, and to improve cooling performance while suppressing a decrease in the conductor space factor in areas of high magnetic flux density.

[0035] Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are conceivable within the scope of the technology disclosed in the present specification, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of another embodiment. [Explanation of symbols]

[0036] 1 housing, 2 front housing, 3 rear housing, 8 rotor, 9 stator, 10 slip ring, 11 brush, 12 voltage regulator, 13 rectifier, 14 control equipment, 17 brush holder, 18 heat sink, 20 connector, 27 protective cover, 33 bearing, 34 shaft, 81 field winding, 82 field core, 83 cooling fan, 90 stator coil, 91 stator core, 92 stator coil wire, 93 insulator, 94 stator coil connecting material, 95 heat pipe, 96 slot, 100 rotating electric machine, 832 main plate, 833 arm plate, 834 blade, 951 uneven portion, 952 uneven pattern, s circumferential length, s0 circumferential length, t radial length, t0 radial length, t1 radial length, a a axial direction, b radial direction

Claims

1. a stator core having a plurality of slots; a stator coil attached to the stator core, the stator coil includes a plurality of heat pipes in which a refrigerant that transports heat by condensation or evaporation is sealed inside a wire, and a stator coil wire in which no refrigerant is sealed inside the wire, A rotating electric machine characterized in that one of the plurality of heat pipes arranged in a certain slot of the plurality of slots and the stator coil wire arranged in another slot of the plurality of slots are connected in series so as to pass electricity.

2. A rotating electric motor as described in claim 1, characterized in that the heat pipe arranged in one slot and the stator coil wire arranged in the other slot are connected so as to be electrically conductive via a stator coil connecting material provided on one end or the other end of the stator core.

3. the heat pipe and the stator coil wire are each disposed in the slot along a path from one end side to the other end side of the stator core, 3. The rotating electric machine according to claim 2, wherein the plurality of heat pipes are connected in series via the stator coil connecting members and the stator coil wires.

4. 4. The rotating electric machine according to claim 1, wherein the stator coil has a cylindrical heat pipe or a U-shaped heat pipe formed to sandwich the stator core.

5. 5. The rotating electric machine according to claim 1, wherein the heat pipe has an inner surface provided with an uneven portion.

6. 6. The rotating electric machine according to claim 1, wherein the heat pipe has an inner surface provided with a spiral or mesh-like uneven pattern.

7. 7. The rotating electric machine according to claim 1, wherein the heat pipes are arranged at different radial positions in the adjacent slots.

8. 8. The rotating electric machine according to claim 1, wherein the heat pipe is provided in the slot at the outermost diameter of the stator core.

9. The heat pipe is also provided on the inner circumferential side within the slot, 9. The rotating electric machine according to claim 1, wherein the radial length of the heat pipe provided on the inner peripheral side is equal to or less than the radial length of the stator coil wire.

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