Rotary electric machine

Abstract

This rotary electric machine comprises: a rotary electric machine body in which a rotor is disposed inside a stator; and a housing having a first case part that accommodates the rotary electric machine body and a second case part that is integrally provided to a lower part of the first case part. This rotary electric machine comprises: an inverter device that is housed inside the second case part and disposed so that heat from a power semiconductor that controls the rotary electric machine body is transmitted to the first case part; and a first heat pipe that is provided to the first case part so as to extend along the circumferential direction of the rotary electric machine body.

Description

Rotating electrical machine

[0001] The present invention relates to a rotating electrical machine.

[0002] JP2020 - 010587A discloses an inverter - integrated motor. The inverter - integrated motor includes a fan interlocked with the motor. The fan sends air to fins for releasing the heat of the inverter and fins for releasing the heat of the motor.

[0003] In such an inverter - integrated motor, when the motor locks, the fan stops, so the inverter device cannot be cooled.

[0004] The present invention has been made in view of such problems, and an object thereof is to provide a rotating electrical machine capable of efficiently cooling an inverter device.

[0005] According to one aspect of the present invention, a rotating electrical machine includes a rotating electrical machine body in which a rotor is disposed inside a stator, and a housing having a first case portion that houses the rotating electrical machine body and a second case portion integrally provided below the first case portion. The rotating electrical machine includes an inverter device housed inside the second case portion and arranged such that heat from a power semiconductor that controls the rotating electrical machine body is transmitted to the first case portion, and a first heat pipe provided in the first case portion along the circumferential direction of the rotating electrical machine body.

[0006] FIG. 1 is a cross - sectional view of the rotating electrical machine according to the present embodiment. FIG. 2 is a cross - sectional view taken along line II - II of FIG. 1. FIG. 3 is a side view of the rotating electrical machine according to the first modification. FIG. 4 is a view showing the rotating electrical machine according to the second modification and is a cross - sectional view corresponding to FIG. 3. FIG. 5 is a view showing the rotating electrical machine according to the third modification and is a cross - sectional view corresponding to FIG. 3. FIG. 6 is a cross - sectional view of the rotating electrical machine according to the fourth modification. FIG. 7 is a cross - sectional view of the rotating electrical machine according to the fifth modification.

[0007] <Embodiment> Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like.

[0008] FIG. 1 is a cross - sectional view of a rotating electrical machine 10 according to the present embodiment. FIG. 2 is a cross - sectional view taken along line II - II of FIG. 1.

[0009] As shown in Figures 1 and 2, the rotating electric machine 10 according to this embodiment is mounted on a vehicle, for example. An example of a vehicle on which it is mounted is an electric vehicle. The rotating electric machine 10 functions as an electric motor that supplies driving force when the vehicle is running. Because the rotating electric machine 10 is required to have a high output when the vehicle is running, it generates a lot of heat. In addition, the rotating electric machine 10 functions as a generator during regenerative braking.

[0010] The rotating electric machine 10 comprises a rotating electric machine body 16 in which a rotor 14 is arranged inside a stator 12, and a housing 18 that constitutes the outer wall. The housing 18 has a first case portion 20 that houses the rotating electric machine body 16, and a second case portion 22 integrally provided at the lower part of the first case portion 20. The housing 18 is, for example, made of cast aluminum.

[0011] Furthermore, the rotating electric machine 10 includes an inverter device 30 that controls the rotating electric machine body 16. The inverter device 30 is housed in the second case portion 22 of the housing 18. The inverter device 30 includes a power semiconductor 32 that controls the rotating electric machine body 16, and is arranged so that heat from the power semiconductor 32 is transferred to the first case portion 20.

[0012] The rotating electric machine 10 includes a first heat pipe 40 provided in the first case portion 20 so as to follow the circumferential direction 36 of the rotating electric machine body 16, and a second heat pipe 44 positioned between the rotating electric machine body 16 and the first heat pipe 40, extending in the axial direction 42 of the rotating electric machine body 16. The axial direction 42 coincides with the extending direction of the shaft 50 of the rotating electric machine body 16. The rotating electric machine 10 also includes a vapor chamber 48 provided between the power semiconductor 32 of the inverter device 30 and the wall surface of the second case portion 22, which transfers heat by utilizing the vaporization and condensation of the working fluid in the chamber 46.

[0013] (Rotating Electric Machine Body) The rotating electric machine body 16 comprises a cylindrical stator 12 and a rotatable rotor 14 held inside the stator 12. A cylindrical shaft 50 is fixed to the center of the rotor 14 with it inserted through it. A coil (not shown) is wound around the stator 12, and permanent magnets (not shown) are provided on the rotor 14.

[0014] When the coils of the rotating electric machine body 16 are energized and the stator 12 is energized, the permanent magnets of the rotor 14 receive magnetic force from the stator 12. Then, the rotor 14 rotates together with the shaft 50 according to the energization state of the stator 12.

[0015] (Housing) The first case portion 20 of the housing 18 has a cylindrical peripheral wall surface 60. One end of the peripheral wall surface 60 is closed by another wall surface 62. The other end of the peripheral wall surface 60 is closed by another wall surface 64.

[0016] (First case section) The rotating electric machine body 16 is housed inside the first case section 20. The stator 12 of the rotating electric machine body 16 is in contact with the peripheral wall surface 60 of the first case section 20.

[0017] The end of the shaft 50 extending from one end of the rotor 14 of the rotating electric machine body 16 is rotatably supported on one wall surface 62 of the first case portion 20, for example, via a bearing (not shown). The end of the shaft 50 extending from the other end of the rotor 14 of the rotating electric machine body 16 is supported on the other wall surface 64 of the first case portion 20, for example, via a bearing (not shown), and extends to the outside of the first case portion 20 by passing through the other wall surface 64.

[0018] (Housing Holes) The first case portion 20 is provided with a plurality of housing holes 70 extending in the axial direction 42. A second heat pipe 44 is arranged in each housing hole 70. The housing holes 70 are arranged at equal intervals in the circumferential direction 36 on the outer circumference of the rotating electric machine body 16.

[0019] The housing hole 70 is composed of a rectangular groove formed on the inner circumferential surface 20A of the first case portion 20. The opening of the rectangular groove is closed by the outer surface of the stator 12 of the rotating electric machine body 16.

[0020] The housing hole 70 extends axially 42 along the stator 12 of the rotating electric machine body 16. The housing hole 70 is longer in the axial direction 42 than the arrangement area 74 where the power semiconductors 32 of the inverter device 30 are arranged. Furthermore, the housing hole 70 is longer than the axial length 42 of the stator 12. As a result, one end of the housing hole 70 protrudes axially 42 beyond one end face 12A of the stator 12. The other end of the housing hole 70 protrudes axially 42 beyond the other end face 12B of the stator 12.

[0021] (Partition Walls) The first case section 20 is provided with a plurality of partition walls 80 erected on the outer peripheral surface 20B of the first case section 20 and arranged at equal intervals in the axial direction 42.

[0022] The partition wall 80 is a plate-like structure that stands upright on the outer circumferential surface 20B of the first case portion 20, and the partition wall 80 is integrally formed with the first case portion 20. The partition wall 80 extends circumferentially 36 along the outer circumferential surface 20B of the first case portion 20 in the region excluding the area where the first case portion 20 is connected to the second case portion 22. In addition, multiple partition walls 80 are formed on the outer circumferential surface 20B of the first case portion 20 over the entire axial area 42.

[0023] (Groove) A groove 84 for housing the first heat pipe 40 is formed between adjacent partition walls 80. The groove 84 is formed at equal intervals in the axial direction 42. The groove 84 is positioned in the axial direction 42 in the area corresponding to the stator 12 of the rotating electric machine body 16. The groove 84 is also formed in the axial direction 42 in the area overlapping with the arrangement area 74 of the power semiconductor 32 of the inverter device 30.

[0024] (Second Case Section) The second case section 22, which constitutes the housing 18, has a rectangular top surface 90 and a side wall surface 92 extending downward from the edge of the top surface 90. As a result, the second case section 22 is formed in the shape of a rectangular container that opens downward, and the lower opening of the second case section 22 is closed by the cover 96.

[0025] The peripheral wall surface 60 of the first case section 20 is connected to the center of the top surface 90 of the second case section 22 via a connecting section 98. As a result, the second case section 22 is integrally provided at the bottom of the first case section 20. Furthermore, since the second case section 22 formed at the bottom of the first case section 20 is rectangular in shape, the housing 18 can be placed on the installation surface with the second case section 22 facing downwards.

[0026] When the rotating electric machine 10 is mounted on a vehicle, the second case portion 22 of the housing 18 is positioned on the lower side.

[0027] (Inverter device) The inverter device 30 provided inside the first case section 20 has a first substrate 100 and a second substrate 104 laminated on the first substrate 100 via a spacer 102.

[0028] A power semiconductor 32 is provided on the second substrate 104. The power semiconductor 32 is composed of a power IC that supplies power to the coils of the rotating electric machine body 16. A drive circuit that controls the switching operation of the power semiconductor 32 is formed on the first substrate 100.

[0029] In addition to the inverter device 30, the second case section 22 is also provided with, for example, a current sensor 106 for detecting the current flowing through the rotating electric machine body 16 and a smoothing capacitor 108 for smoothing the voltage. The current sensor 106 and the smoothing capacitor 108 constitute the inverter circuit.

[0030] Furthermore, the inverter device 30 is arranged so that heat from the power semiconductor 32 is transferred to the first case section 20.

[0031] (Vapor Chamber) A vapor chamber 48 is provided inside the second case section 22.

[0032] The vapor chamber 48 comprises a rectangular chamber 46 that forms a sealed space. A wick 110 is provided inside the chamber 46 along its inner circumferential surface. The wick 110 is, for example, a metal capillary structure and comprises numerous capillaries. A working fluid, which is a liquid, is contained inside the chamber 46. The vapor chamber 48 transfers locally applied heat through the vaporization and condensation of the working fluid.

[0033] The vapor chamber 48 is provided between the power semiconductor 32 and the top surface 90 which serves as the wall surface of the second case portion 22. The second substrate 104 on which the power semiconductor 32 is mounted is in surface contact with the lower surface 48A of the vapor chamber 48. The second substrate 104 prevents the terminals of the power semiconductor 32 from contacting the lower surface 48A of the vapor chamber 48, and also transfers heat from the power semiconductor 32 to the lower surface 48A.

[0034] The upper surface 48B of the vapor chamber 48 is in surface contact with the top surface 90 of the second case portion 22. As a result, heat from the power semiconductor 32 is transferred to the vapor chamber 48 via the second substrate 104. The heat transferred to the vapor chamber 48 is then transferred to the first case portion 20 via the top surface 90 and the connecting portion 98 of the second case portion 22.

[0035] Alternatively, the rotating electric machine 10 may transfer heat from the power semiconductor 32 to the first case portion 20 by directly contacting the second substrate 104 having the power semiconductor 32 with the top surface 90 of the second case portion 22.

[0036] To explain in more detail, when heat from the power semiconductor 32 is applied to the lower surface 48A of the vapor chamber 48 via the second substrate 104, the working fluid on the lower surface 48A evaporates within the chamber 46. An evaporation area E is formed on the lower surface 48A corresponding to the power semiconductor 32 where the working fluid evaporates.

[0037] The vapor 116 generated from the working fluid moves within the chamber 46, diffusing heat. The vapor 116 evaporated on the lower surface 48A rises within the chamber 46 due to the vapor flow and moves toward the upper surface 48B. This promotes the transfer of heat applied to the lower surface 48A toward the upper surface 48B.

[0038] At this time, the upper surface 48B is at a lower temperature than the lower surface 48A. Therefore, the steam 116 that reaches the upper surface 48B is cooled on the upper surface 48B side, condenses, and liquefies. A condensation area C is formed on the upper surface 48B side of the chamber 46 where the steam 116 is condensed and liquefied.

[0039] The liquefied working fluid moves towards the lower surface 48A via the wick 110. At this time, capillary action occurs in the liquefied working fluid due to the capillaries formed by the wick 110. In addition, gravity G acts on the working fluid liquefied on the upper surface 48B, acting from the upper surface 48B towards the lower surface 48A. This promotes the movement of the liquefied working fluid towards the lower surface 48A.

[0040] The working fluid that has moved to the lower surface 48A then evaporates again in the evaporation area E. Through repeated evaporation and condensation of the working fluid, heat from the power semiconductor 32 is transferred to the upper surface 48B of the chamber 46, and the heat from the upper surface 48B is transferred to the first case section 20 via the top surface 90 of the second case section 22.

[0041] (First Heat Pipe) The first heat pipes 40 are each arranged in grooves 84 formed between partition walls 80 of the first case portion 20. As a result, multiple first heat pipes 40 are provided at equal intervals in the axial direction 42.

[0042] Furthermore, the first heat pipe 40, in which each groove 84 is located, is positioned in a location corresponding to the stator 12 of the rotating electric machine body 16. In addition, the first heat pipe 40 is positioned in a location that overlaps with the arrangement area 74 of the power semiconductor 32 of the inverter device 30 in the axial direction 42.

[0043] The first heat pipe 40 is formed in a rod shape. The first heat pipe 40 is provided in the groove 84 in a curved state along the outer circumferential surface 20B of the first case portion 20. As a result, the first heat pipe 40 is positioned along the circumferential direction 36 of the rotating electric machine body 16.

[0044] In the groove 84, a pair of first heat pipes 40 are arranged in the circumferential direction 36 (see FIG. 2). Each of the pair of first heat pipes 40 arranged in the same groove 84 is arranged such that the lower end portion 40A is close to the connecting portion 98. Also, the pair of first heat pipes 40 arranged in the same groove 84 are arranged such that the upper end portions 40B are separated from each other above the shaft 50 of the rotating electric machine body 16.

[0045] In addition, in the present embodiment, the case where a pair of first heat pipes 40 are arranged in the groove 84 will be described as an example, but the first heat pipe 40 is not limited to this shape.

[0046] The first heat pipe 40 may be, for example, circular when viewed from the axial direction 42. Also, the first heat pipe 40 may be, for example, an arc shape in which only the side on the vapor chamber 48 provided in the second case portion 22 is cut out. The shape of the first heat pipe 40 is appropriately selected according to the installation location.

[0047] The height dimension of the partition wall 80 erected on the outer peripheral surface 20B of the first case portion 20 is larger than the outer dimension of the first heat pipe 40 arranged in the groove 84. Thereby, the partition wall 80 constitutes a heat dissipation plate protruding outward from the first heat pipe 40 arranged in the groove 84.

[0048] The first heat pipe 40 includes a pipe 120 whose ends are closed. The pipe 120 forms a sealed space inside. Inside the pipe 120, a wick 110 is provided along the inner peripheral surface. The wick 110 is, for example, a capillary structure made of metal and includes a large number of capillaries. Inside the pipe 120, a working fluid made of a liquid is accommodated. The first heat pipe 40 transfers the heat locally applied by the vaporization and condensation of the working fluid.

[0049] Specifically, heat is applied to the lower end 40A of the first heat pipe 40, which is transferred from the power semiconductor 32 to the first case section 20 via the vapor chamber 48 and the top surface 90 of the second case section 22. As a result, the working fluid on the lower end 40A side evaporates within the pipe 120. An evaporation area E is formed at the lower end 40A of the first heat pipe 40 where the working fluid evaporates.

[0050] The vapor 116 generated from the working fluid moves within the pipe 120, diffusing heat. The vapor 116 evaporated at the lower end 40A of the first heat pipe 40 rises along the pipe 120 due to the vapor flow and moves toward the upper end 40B. This promotes the transfer of heat applied to the lower end 40A toward the upper end 40B.

[0051] At this time, the upper end 40B is at a lower temperature than the lower end 40A. Therefore, the steam 116 that reaches the upper end 40B side is cooled, condensed, and liquefied. A condensation area C is formed in the upper end 40B side of the pipe 120 where the steam 116 is condensed and liquefied.

[0052] The liquefied working fluid moves towards the lower end 40A via the wick 110. At this time, capillary action occurs in the liquefied working fluid due to the capillaries formed by the wick 110. In addition, gravity G acts on the working fluid that has liquefied at the upper end 40B, acting from the upper end 40B towards the lower end 40A. This promotes the movement of the liquefied working fluid towards the lower end 40A.

[0053] The working fluid that has moved towards the lower end 40A then evaporates again in the evaporation area E. Through repeated evaporation and condensation of the working fluid, the heat from the power semiconductor 32 moves to the upper side of the first case portion 20 and is diffused onto the outer circumferential surface 20B of the first case portion 20. The heat diffused onto the outer circumferential surface 20B of the first case portion 20 is released to the outside by the heat sink formed by the partition wall 80.

[0054] (Second Heat Pipe) The second heat pipes 44 are arranged in each of the housing holes 70 formed in the first case portion 20. As a result, multiple second heat pipes 44 are provided at intervals in the circumferential direction 36.

[0055] Furthermore, the second heat pipe 44 extends along the entire length of the housing hole 70. As a result, the second heat pipe 44 extends in the axial direction 42 beyond the arrangement area 74 of the power semiconductor 32 of the inverter device 30 to one side and the other side.

[0056] The second heat pipe 44 is formed in a rod shape. The second heat pipe 44 is configured in the same way as the first heat pipe 40. The second heat pipe 44 includes a pipe 120 with a closed end. The pipe 120 forms a sealed space inside. A wick 110 is provided inside the pipe 120 along its inner circumference. The wick 110 is, for example, a metal capillary structure and comprises numerous capillaries. A working fluid consisting of liquid is contained inside the pipe 120. The second heat pipe 44 transfers locally applied heat by vaporizing and condensing the working fluid.

[0057] To explain in more detail, when heat is applied from the power semiconductor 32 to a corresponding area 74 of the inverter device 30, the working fluid in the corresponding area evaporates within the pipe 120 of the second heat pipe 44. An evaporation area E is formed in the corresponding area of ​​the second heat pipe 44 where the working fluid evaporates.

[0058] The vapor 116 generated from the working fluid moves through the pipe 120, diffusing heat. The vapor 116 evaporated in the evaporation area E moves to one end 44A and the other end 44B of the second heat pipe 44.

[0059] At this time, the temperature at one end 44A and the other end 44B is lower than that of the corresponding parts of the evaporation area E. Therefore, the steam 116 that reaches the one end 44A side and the other end 44B side is cooled at the one end 44A side and the other end 44B side, and condenses and liquefies. A condensation area C is formed at the one end 44A side and the other end 44B side of the second heat pipe 44 where the steam 116 is condensed and liquefied.

[0060] The liquefied working fluid moves to the corresponding part of the evaporation area E via the wick 110. At this time, capillary action occurs in the liquefied working fluid due to the capillaries formed by the wick 110.

[0061] The working fluid that has moved to the corresponding part of the evaporation area E then evaporates again in the evaporation area E, and the heat from the power semiconductor 32 is diffused throughout the entire length of the first case section 20, moving to one end and the other end of the first case section 20. The heat diffused throughout the entire length of the first case section 20 is released to the outside via the heat sink formed by the first heat pipe 40 and the partition wall 80 described above.

[0062] Furthermore, the heat generated in the rotating electric machine body 16 is transferred from the stator 12 side to the outer circumference side by the second heat pipe 44 which is in contact with the outer surface of the stator 12. The heat from the rotating electric machine body 16 is released from the heat sinks formed by the outer circumference 20B of the first case section 20 and the partition wall 80.

[0063] (Operation and Effects) The rotating electric machine 10 of this embodiment includes a rotating electric machine body 16 in which a rotor 14 is arranged inside a stator 12. The rotating electric machine 10 includes a housing 18 having a first case portion 20 that houses the rotating electric machine body 16 and a second case portion 22 integrally provided at the lower part of the first case portion 20. The rotating electric machine 10 includes an inverter device 30 housed inside the second case portion 22 and arranged so as to transfer heat from a power semiconductor 32 that controls the rotating electric machine body 16 to the first case portion 20. The rotating electric machine 10 includes a first heat pipe 40 provided in the first case portion 20 along the circumferential direction 36 of the rotating electric machine body 16 (see Figures 1 and 2).

[0064] In this configuration, heat from the power semiconductor 32 of the inverter device 30 housed in the second case section 22 is transferred to the first case section 20 located above the second case section 22. The heat transferred to the first case section 20 is then moved upwards to the first case section 20 by the first heat pipe 40, which is arranged along the circumferential direction 36 of the rotating electric machine body 16, diffused within the first case section 20, and released to the outside of the first case section 20.

[0065] This allows the rotating electric machine 10 to efficiently cool the inverter device 30.

[0066] Furthermore, unlike the case where the inverter is cooled by the airflow from a fan linked to the motor, the rotating electric machine 10 can cool the inverter device 30 even when the rotating electric machine body 16, which acts as the motor, is stopped.

[0067] Furthermore, the rotating electric machine 10 can cool the inverter device 30 without providing dedicated fins for cooling the inverter device 30, thus enabling miniaturization and cost reduction compared to cases where dedicated fins are required.

[0068] The first heat pipe 40 then moves heat upward from the power semiconductor 32 by evaporating the working fluid inside it with the heat from the power semiconductor 32 and causing it to rise. As a result, the rotating electric machine 10 can transfer heat more efficiently compared to the case where the first heat pipe 40 extends laterally.

[0069] Furthermore, the rotating electric machine 10 is further equipped with a second heat pipe 44 positioned between the rotating electric machine body 16 and the first heat pipe 40, and extending in the axial direction 42 of the rotating electric machine body 16 (see Figures 1 and 2).

[0070] In this configuration, the heat from the power semiconductor 32 transmitted to the first case section 20 is moved axially 42 by the second heat pipe 44 extending in the axial direction 42 of the rotating electric machine body 16, and diffused throughout the entire length of the second case section 22. As a result, the rotating electric machine 10 can release the heat diffused throughout the entire length of the second case section 22 to the outside via the second case section 22.

[0071] Furthermore, the second heat pipe 44 is positioned between the rotating electric machine body 16 and the first heat pipe 40. Therefore, the heat generated in the rotating electric machine body 16 is transferred from the stator 12 side to the outer circumference side by the second heat pipe 44.

[0072] As a result, the rotating electric machine 10 can release heat from the rotating electric machine body 16 through the outer circumferential surface 20B of the first case portion 20.

[0073] Furthermore, the rotating electric machine 10 is provided between the power semiconductor 32 and the wall surface of the second case section 22, and further includes a vapor chamber 48 that transfers heat by utilizing the vaporization and condensation of the working fluid in the chamber 46 (see Figures 1 and 2).

[0074] In this configuration, a vapor chamber 48 is provided between the power semiconductor 32 of the inverter device 30 and the wall surface of the second case section 22. The heat from the power semiconductor 32 applied to the vapor chamber 48 is transferred to the wall surface of the second case section 22 by utilizing the vaporization and condensation of the working fluid in the chamber 46.

[0075] Therefore, the rotating electric machine 10 can efficiently transfer heat from the power semiconductor 32 to the first case section 20 via the vapor chamber 48.

[0076] The heat transferred to the first case section 20 is then released from the outer circumferential surface 20B of the first case section 20 via the first heat pipe 40 and the second heat pipe 44 described above.

[0077] Furthermore, in the rotating electric machine 10, multiple first heat pipes 40 are provided at intervals in the axial direction 42, and multiple second heat pipes 44 are provided at intervals in the circumferential direction 36.

[0078] In this configuration, the rotating electric machine 10 is able to disperse heat from the power semiconductor 32 throughout the entire area of ​​the first case 20 by the multiple first heat pipes 40 and the multiple second heat pipes 44.

[0079] Furthermore, in the rotating electric machine 10, the first case portion 20 extends in the axial direction 42 and is provided with a plurality of housing holes 70 in which the second heat pipes 44 are each arranged. The first case portion 20 is provided with a plurality of partition walls 80 erected on the outer peripheral surface 20B of the first case portion 20 and spaced apart in the axial direction 42. The first heat pipes 40 are arranged in grooves 84 formed between the partition walls 80, and the partition walls 80 protrude outward from the first heat pipes 40 arranged in the grooves 84.

[0080] In this configuration, the first heat pipe 40 and the second heat pipe 44 are provided in the first case portion 20 by housing the second heat pipe 44 in the housing hole 70 of the first case portion 20 and arranging the first heat pipe 40 in the groove 84 between the partition walls 80.

[0081] Furthermore, the partition wall 80 protrudes outward from the first heat pipe 40, which is positioned within the groove 84. As a result, the rotating electric machine 10 can utilize the partition wall 80, which protrudes outward from the first heat pipe 40, as a heat sink.

[0082] Furthermore, since the groove 84 for housing the first heat pipe 40 is formed on the outer circumferential surface 20B of the first case portion 20, it is possible to easily position the first heat pipe 40 within the groove 84. Also, since the first heat pipe 40 is positioned on the outer circumferential surface 20B of the first case portion 20, it is possible to improve the heat dissipation effect compared to when the first heat pipe 40 is positioned inside the first case portion 20.

[0083] Furthermore, in the rotating electric machine 10, the first heat pipe 40 is positioned in a location that overlaps with the arrangement area 74 of the power semiconductor 32 in the axial direction 42, and the second heat pipe 44 extends further in the axial direction 42 than the arrangement area 74 (see Figures 1 to 3).

[0084] In this configuration, the rotating electric machine 10 can efficiently dissipate heat from the power semiconductor 32 by the first heat pipe 40, which is positioned in a location that overlaps with the arrangement area 74 of the power semiconductor 32 in the axial direction 42.

[0085] Furthermore, the second heat pipe 44 extends axially 42 beyond the placement region 74. Therefore, the second heat pipe 44 can dissipate heat by moving the heat transferred from the power semiconductor 32 to the portion that overlaps with the placement region 74 to the portion that does not overlap with the placement region 74.

[0086] Next, modifications of this embodiment will be described with reference to the drawings. In each modification, parts that are the same as or equivalent to those in the embodiment will be denoted by the same reference numerals and their descriptions will be omitted, while the descriptions will focus on the different parts. In addition, in each modification, the same or equivalent effects as those in the embodiment will be omitted from the description.

[0087] <First Modified Example> Figure 3 is a side view of the rotating electric machine 200 according to the first modified example. Compared to the embodiment, the rotating electric machine 200 according to the first modified example has a different region in which the first heat pipe 40 is arranged.

[0088] In other words, the first heat pipe 40 of the rotating electric machine 200 is provided in a portion that overlaps with the arrangement region 74 where the power semiconductor 32 of the inverter device 30 is arranged in the axial direction 42. Specifically, the first heat pipe 40 is provided in a groove 84 located above the vapor chamber 48 that transmits heat from the power semiconductor 32 in the axial direction 42.

[0089] Furthermore, the second heat pipe 44 extends axially 42 beyond the placement area 74. Specifically, the second heat pipe 44 extends axially 42 to one end and the other end beyond the placement area 74.

[0090] As a result, the rotating electric machine 200 diffuses the heat from the power semiconductor 32 transmitted via the vapor chamber 48 upwards to the first case section 20 while keeping the number of first heat pipes 40 used to a minimum. The rotating electric machine 200 also diffuses the heat from the power semiconductor 32 in the axial direction 42 of the first case section 20 using the second heat pipe 44.

[0091] This modified example produces the same effects and benefits as the embodiment.

[0092] <Second Modification> Figure 4 is a diagram showing a rotating electric machine 210 according to the second modification, and is a cross-sectional view corresponding to Figure 3. The rotating electric machine 210 according to the second modification has a different arrangement spacing of the second heat pipes 44 compared to the embodiment.

[0093] In other words, in the rotating electric machine 210, the multiple second heat pipes 44 provided in the lower region 212 of the first case portion 20 closer to the second case portion 22 are arranged more densely than the multiple second heat pipes 44 provided in other regions (upper regions) that are further away from the second case portion 22.

[0094] As a result, heat from the power semiconductor 32, which is easily transferred from the second case section 22 to the lower part of the first case section 20, is efficiently dispersed in the axial direction 42 by a plurality of closely arranged second heat pipes 44.

[0095] (Operation and Effects) In the rotating electric machine 210 of this embodiment, the multiple second heat pipes 44 provided in the lower region 212, which is the region of the first case portion 20 closer to the second case portion 22, are arranged more densely than the multiple second heat pipes 44 provided in other regions further away from the second case portion 22 (see Figure 4).

[0096] In this configuration, the rotating electric machine 210 can efficiently transfer heat from the power semiconductor 32 in the axial direction 42 by densely arranging the second heat pipes 44 in the lower region 212, which is the region closer to the second case portion 22.

[0097] <Third Modification> Figure 5 shows a rotating electric machine 220 according to the third modification, and is a cross-sectional view corresponding to Figure 3. Compared to the embodiment, the rotating electric machine 220 according to the third modification has a different cross-sectional area of ​​the second heat pipe 44 depending on the installation location.

[0098] In other words, in the rotating electric machine 220, the cross-sectional area of ​​the second heat pipe 44 provided in the lower region 212 of the first case portion 20 closer to the second case portion 22 is larger than the cross-sectional area of ​​the second heat pipe 44 provided in other regions (upper regions) further away from the second case portion 22.

[0099] As a result, heat from the power semiconductor 32, which is easily transferred from the second case section 22 to the lower part of the first case section 20, is efficiently diffused axially 42 by the second heat pipe 44, which has a large cross-sectional area.

[0100] Furthermore, the rotating electric machine 220 may have the second heat pipes 44 in the lower region 212 arranged more densely than the second heat pipes 44 in other regions, and the cross-sectional area of ​​the second heat pipes 44 in the lower region 212 may be larger than the cross-sectional area of ​​the second heat pipes 44 in other regions.

[0101] (Operation and Effects) In the rotating electric machine 220 of this embodiment, the cross-sectional area of ​​the second heat pipe 44 provided in the lower region 212, which is a region of the first case portion 20 closer to the second case portion 22, is larger than the cross-sectional area of ​​the second heat pipe 44 provided in other regions further away from the second case portion 22 (see Figure 5).

[0102] In this configuration, the rotating electric machine 220 can efficiently transfer heat from the power semiconductor 32 in the axial direction 42 by increasing the cross-sectional area of ​​the second heat pipe 44 in the lower region 212, which is the region closer to the second case portion 22.

[0103] <Fourth Modification> Figure 6 is a cross-sectional view of the rotating electric machine 230 according to the fourth modification. The rotating electric machine 230 according to the fourth modification has a different heat pipe shape compared to the embodiment.

[0104] In other words, the rotating electric machine 230 comprises an integrated structure 232 in which the first heat pipe 40 and the second heat pipe 44 are connected and integrated at their intersection, and a separate second heat pipe 44. Working fluid flows through the integrated structure 232, both inside the first heat pipe 40 and the second heat pipe 44.

[0105] In this embodiment, we will explain using the case where a separate second heat pipe 44 is provided as an example, but the separate second heat pipe 44 may be connected to one of the first heat pipes 40 to form an integrated unit.

[0106] As a result, the heat from the power semiconductor 32, which is transferred from the second case section 22 to the lower part of the first case section 20, is transferred from the second heat pipe 44 of the integrated structure 232 to the first heat pipe 40 and diffused throughout the entire first case section 20.

[0107] (Operation and Effects) The rotating electric machine 230 of this embodiment has an integrated structure 232 in which the first heat pipe 40 and the second heat pipe 44 are integrated (see Figure 6).

[0108] In this configuration, the heat from the power semiconductor 32, which is transferred from the second case section 22 to the lower part of the first case section 20, is transferred from the second heat pipe 44 of the integrated structure 232 to the first heat pipe 40 and diffused throughout the entire first case section 20.

[0109] This allows the rotating electric machine 230 to efficiently dissipate heat from the power semiconductor 32 throughout the entire first case section 20.

[0110] <Fifth Modification> Figure 7 is a cross-sectional view of the rotating electric machine 300 according to the fifth modification. The rotating electric machine 300 according to the fifth modification differs from the embodiment in that the first case portion 20 has the same configuration as each of the heat pipes 40, 44 and the vapor chamber 48.

[0111] In other words, the rotating electric machine 300 comprises a rotating electric machine body 16 in which a rotor 14 is arranged inside a stator 12, and a housing 18 having a first case portion 20 that houses the rotating electric machine body 16 and a second case portion 22 integrally provided at the lower part of the first case portion 20. Multiple plate-shaped partition walls 80 are formed on the outer peripheral surface 20B of the first case portion 20 of the housing 18 in the axial direction 42 (see Figure 1). The housing 18 is formed, for example, by a 3D printer using aluminum.

[0112] The rotating electric machine 300 is housed inside the second case section 22 and includes an inverter device 30 arranged so that heat from the power semiconductor 32 that controls the rotating electric machine body 16 is transferred to the first case section 20.

[0113] (First heat transfer section) A first sealed space 310 is formed in the first case portion 20 of the housing 18 so as to be aligned with the circumferential direction 36 of the rotating electric machine body 16. A wick 110 is provided inside the first sealed space 310 along the inner circumferential surface. The wick 110 is, for example, a metal capillary structure and comprises a large number of capillaries. A working fluid consisting of liquid is sealed inside the first sealed space 310.

[0114] As a result, the first case section 20 is provided with a first heat transfer section 312 that transfers heat by utilizing the vaporization and condensation of the working fluid sealed in the first sealed space 310. The first heat transfer section 312 has the same function as the first heat pipe 40 in the embodiment.

[0115] One method for forming the first heat transfer section 312 is to house the wick 110 and working fluid in a space opened in the first case section 20, and then close the opening with a plug component.

[0116] Multiple first heat transfer units 312 are provided at equal intervals in the axial direction 42 (see Figure 1). Each first heat transfer unit 312 is positioned in the axial direction 42 in a location corresponding to the stator 12 of the rotating electric machine body 16 (see Figure 1). Furthermore, each first heat transfer unit 312 is positioned in the axial direction 42 in a location that overlaps with the arrangement area 74 (see Figure 1) of the power semiconductor 32 of the inverter device 30.

[0117] A pair of first heat transfer sections 312 are arranged on the circumference over which the first heat transfer section 312 extends. A connecting section 98 is positioned between the lower ends 312A of the two first heat transfer sections 312 that are arranged on the same circumference. The upper ends 312B of the two first heat transfer sections 312 that are arranged on the same circumference are spaced apart from each other above the shaft 50 of the rotating electric machine body 16.

[0118] (Second heat transfer section) Between the rotating electric machine body 16 of the first case section 20 and the first sealed space 310, a second sealed space 320 is formed, extending in the axial direction 42 (see Figure 1) of the rotating electric machine body 16. A wick 110 is provided inside the second sealed space 320 along its inner circumferential surface. The wick 110 is, for example, a metal capillary structure and comprises numerous capillaries. A working fluid consisting of liquid is sealed inside the second sealed space 320.

[0119] As a result, the first case section 20 is provided with a second heat transfer section 322 that transfers heat by utilizing the vaporization and condensation of the working fluid sealed in the second sealed space 320. The second heat transfer section 322 has the same function as the second heat pipe 44 in the embodiment.

[0120] One method for forming the second heat transfer section 322 is to house the wick 110 and working fluid in a space opened in the first case section 20 and close the opening with a plug component.

[0121] Multiple second heat transfer sections 322 are provided at intervals in the circumferential direction 36. Furthermore, the second heat transfer sections 322 extend over substantially the entire length of the second case section 22. As a result, the second heat transfer sections 322 extend in the axial direction 42 (see Figure 1) beyond the arrangement area 74 (see Figure 1) of the power semiconductors 32 of the inverter device 30 to one side and the other side of the axial direction 42 (see Figure 1).

[0122] (Third heat transfer section) A rectangular chamber 46 is formed in the second case section 22. A wick 110 is provided inside the chamber 46 along its inner circumferential surface. The wick 110 is, for example, a metal capillary structure and comprises numerous capillaries. A working fluid consisting of liquid is sealed inside the chamber 46.

[0123] As a result, the second case section 22 is provided with a third heat transfer section 330 that transfers heat by utilizing the vaporization and condensation of the working fluid sealed in the chamber 46. The third heat transfer section 330 has the same function as the vapor chamber 48 in the embodiment.

[0124] One method for forming the third heat transfer section 330 is to house the wick 110 and working fluid in a space opened in the first case section 20 and close the opening with a plug component.

[0125] The power semiconductor 32 of the inverter device 30 is in contact with the wall surface of the chamber 46 that constitutes the third heat transfer section 330 via the second substrate 104. As a result, the power semiconductor 32 is positioned so that heat from the power semiconductor 32 is transferred to the third heat transfer section 330.

[0126] (Operation and Effects) The rotating electric machine 300 of this embodiment comprises a rotating electric machine body 16 in which a rotor 14 is arranged inside a stator 12, and a housing 18 having a first case portion 20 that houses the rotating electric machine body 16 and a second case portion 22 integrally provided at the lower part of the first case portion 20. The rotating electric machine 300 includes an inverter device 30 housed inside the second case portion 22 and arranged so as to transfer heat from a power semiconductor 32 that controls the rotating electric machine body 16 to the first case portion 20. The rotating electric machine 300 has a first sealed space 310 formed in the first case portion 20 along the circumferential direction 36 of the rotating electric machine body 16, and includes a first heat transfer section 312 that transfers heat by utilizing the vaporization and condensation of a working fluid sealed in the first sealed space 310 (see Figure 7).

[0127] In this configuration, heat from the power semiconductor 32 of the inverter device 30 housed in the second case section 22 is transferred to the first case section 20 located above the second case section 22. The heat transferred to the first case section 20 is then moved upward to the first case section 20 by the first heat transfer section 312, which is arranged along the circumferential direction 36 of the rotating electric machine body 16, and is diffused within the first case section 20 before being released to the outside of the first case section 20.

[0128] This allows the rotating electric machine 300 to efficiently cool the inverter device 30.

[0129] The rotating electric machine 300 of this embodiment has a second sealed space 320 formed in the second case portion 22 between the rotating electric machine body 16 and the first sealed space 310, extending in the axial direction 42 (see Figure 1) of the rotating electric machine body 16, and further comprises a second heat transfer unit 322 that transfers heat by utilizing the vaporization and condensation of the working fluid sealed in the second sealed space 320 (see Figure 7).

[0130] In this configuration, the heat from the power semiconductor 32 transmitted to the first case section 20 is moved in the axial direction 42 by the second heat transfer section 322, which extends in the axial direction 42 of the rotating electric machine body 16, and diffused throughout the entire length of the second case section 22. As a result, the rotating electric machine 300 can release the heat diffused throughout the entire length of the second case section 22 to the outside via the second case section 22.

[0131] Furthermore, the second heat transfer unit 322 is positioned between the rotating electric machine body 16 and the first heat transfer unit 312. Therefore, the heat generated in the rotating electric machine body 16 is transferred from the stator 12 side to the outer circumference side by the second heat transfer unit 322.

[0132] As a result, the rotating electric machine 300 can release heat from the rotating electric machine body 16 through the outer circumferential surface 20B of the first case portion 20.

[0133] The rotating electric machine 300 of this embodiment has a chamber 46 formed in the second case portion 22, and further includes a third heat transfer portion 330 that transfers heat by utilizing the vaporization and condensation of the working fluid sealed in the chamber 46. The power semiconductor 32 is arranged so that heat from the power semiconductor 32 is transferred to the third heat transfer portion 330 (see Figure 7).

[0134] In this configuration, a third heat transfer section 330 is formed in the second case section 22.

[0135] Therefore, the rotating electric machine 300 can efficiently transfer heat from the power semiconductor 32 to the first case section 20 via the third heat transfer section 330.

[0136] The heat transferred to the first case portion 20 is then released from the outer circumferential surface 20B of the first case portion 20 via the first heat transfer portion 312 and the second heat transfer portion 322.

[0137] Although embodiments and various modifications of the present invention have been described above, these embodiments only represent a part of the application of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0138] The embodiments described above were explained using the example of using the rotating electric machines 10, 200, 210, 220, 230, and 300 in an electric vehicle, but the applications of the rotating electric machines 10, 200, 210, 220, 230, and 300 are not limited to this. The rotating electric machines 10, 200, 210, 220, 230, and 300 may be used for other purposes.

Claims

1. A rotating electric machine comprising: a rotating electric machine body having a rotor arranged inside a stator; a housing having a first case portion for housing the rotating electric machine body and a second case portion integrally provided at the lower part of the first case portion; an inverter device housed inside the second case portion and arranged so as to transfer heat from a power semiconductor that controls the rotating electric machine body to the first case portion; and a first heat pipe provided in the first case portion so as to be along the circumferential direction of the rotating electric machine body.

2. A rotating electric machine according to claim 1, further comprising a second heat pipe disposed between the rotating electric machine body and the first heat pipe, and extending in the axial direction of the rotating electric machine body.

3. A rotating electric machine according to claim 2, further comprising a vapor chamber provided between the power semiconductor and the wall surface of the second case portion, which transfers heat by utilizing the vaporization and condensation of the working fluid in the chamber.

4. A rotating electric machine according to claim 3, wherein the first heat pipes are provided in a plurality at intervals in the axial direction, and the second heat pipes are provided in a plurality at intervals in the circumferential direction.

5. A rotating electric machine according to claim 4, wherein the first case portion comprises a plurality of housing holes extending in the axial direction, each of which the second heat pipes are arranged, and a plurality of partition walls erected on the outer circumferential surface of the first case portion and spaced apart in the axial direction, wherein the first heat pipes are arranged in grooves formed between the partition walls, and the partition walls protrude outward from the first heat pipes arranged in the grooves.

6. A rotating electric machine according to claim 5, wherein the first heat pipe is positioned in a location that overlaps with the arrangement region of the power semiconductor in the axial direction, and the second heat pipe extends further in the axial direction than the arrangement region.

7. A rotating electric machine according to claim 6, wherein a plurality of second heat pipes provided in the region of the first case portion closer to the second case portion are arranged more densely than a plurality of second heat pipes provided in other regions further away from the second case portion.

8. A rotating electric machine according to claim 6 or claim 7, wherein the cross-sectional area of ​​the second heat pipe provided in the first case portion closer to the second case portion is larger than the cross-sectional area of ​​the second heat pipe provided in other portions further away from the second case portion.

9. A rotating electric machine according to claim 6, wherein the first heat pipe and the second heat pipe are integrated into a single integrated structure.

10. A rotating electric machine comprising: a rotating electric machine body having a rotor disposed inside a stator; a housing having a first case portion for housing the rotating electric machine body and a second case portion integrally provided at the lower part of the first case portion; an inverter device housed inside the second case portion and arranged so as to transfer heat from a power semiconductor that controls the rotating electric machine body to the first case portion; and a first sealed space formed in the first case portion along the circumferential direction of the rotating electric machine body, and a first heat transfer section that transfers heat by utilizing the vaporization and condensation of a working fluid sealed in the first sealed space.

11. A rotating electric machine according to claim 10, wherein a second sealed space extending in the axial direction of the rotating electric machine body is formed in the first case portion between the rotating electric machine body and the first sealed space, and the rotating electric machine further comprises a second heat transfer section that transfers heat by utilizing the vaporization and condensation of a working fluid sealed in the second sealed space.

12. A rotating electric machine according to claim 11, wherein a chamber is formed in the second case portion, and the machine further comprises a third heat transfer portion that transfers heat by utilizing the vaporization and condensation of a working fluid sealed in the chamber, and the power semiconductor is arranged such that heat from the power semiconductor is transferred to the third heat transfer portion.

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