Electrical machinery

Abstract

To provide an electric machine that enables miniaturization of a housing while maintaining cooling performance.SOLUTION: An electric machine includes a housing 10, a rotor shaft 20, a rotor 30, a stator 40, an internal cooler 50, and an external cooling device 60. The stator 40 includes a stator core 41 and a stator winding 42, and is accommodated in an accommodation space S. The internal cooler 50 includes a hollow first binding ring 51, a hollow second binding ring 52, and a hollow first cooling pipe 54. The first binding ring 51 restrains the first winding end portion 45, which is one end portion of the stator winding 42 in an axial direction, outside the stator core 41. The second binding ring 52 restrains the second winding end portion 46, which is the other end portion of the stator winding 42 in an axial direction, outside the stator core 41. The first cooling pipe 54 penetrates the stator core 41 and connects the first binding ring 51 and the second binding ring 52.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric machine.

Background Art

[0002] Conventionally, in a rotary electric machine, a rotor and a stator are arranged in the internal space of a housing. When the stator is air-cooled, a duct for efficiently cooling the stator by the airflow generated by a fan may be provided in the housing so as to be connected to the internal space of the housing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in this electric machine, the housing becomes larger due to the provision of the duct. When the stator is air-cooled without providing a duct, the cooling performance may decrease.

[0005] An object of the present invention is to provide an electric machine that enables miniaturization of the housing while maintaining cooling performance.

Means for Solving the Problems

[0006] An electric machine according to one embodiment of the present invention comprises a housing, a rotor shaft, a rotor, a stator, an internal cooler, and an external cooling device. A housing space is provided inside the housing. The rotor shaft is supported by the housing so as to extend axially and be rotatable. The rotor is housed in the housing space and attached to the rotor shaft. The stator has a stator core provided radially outside the rotor and stator windings that penetrate the stator core axially, and is housed in the housing space. The internal cooler has a hollow first binding ring, a hollow second binding ring, and a hollow first cooling tube. The first binding ring restrains a first winding end, which is one end of the stator winding in the axial direction, outside the stator core. The second binding ring restrains a second winding end, which is the other end of the stator winding in the axial direction, outside the stator core. The first cooling tube penetrates the stator core and connects the first and second binding rings. The external cooling device is located outside the housing and cools the heat transfer fluid discharged from the internal cooler and supplies the heat transfer fluid to the internal cooler. [Effects of the Invention]

[0007] According to the above-described embodiment of the present invention, the electromechanical device can be miniaturized while maintaining cooling performance. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an illustrative cross-sectional view of the configuration of an electromachine according to the first embodiment. [Figure 2] Figure 2 is an exemplary side view showing the first binding ring, first cooling tube, and fins of the first embodiment. [Figure 3] Figure 3 is an exemplary cross-sectional view showing an electromachine that generates airflow from a fan according to the first embodiment. [Figure 4] Figure 4 is an exemplary cross-sectional view showing the electrical machinery in which airflow is generated by the fan of the first embodiment, along the line F4-F4 in Figure 3. [Figure 5] Figure 5 is a schematic perspective view showing the internal cooler of the second embodiment. [Figure 6] Figure 6 is an illustrative cross-sectional view of the configuration of the electromachine according to the third embodiment. [Modes for carrying out the invention]

[0009] Embodiments will be described in detail below with reference to the attached drawings. However, the present invention is not limited by these embodiments.

[0010] The following embodiments include similar components. These similar components are given common reference numerals, and redundant descriptions are omitted. Furthermore, the drawings are schematic, and the dimensional relationships and proportions of each element may differ from reality. In addition, there may be differences in dimensional relationships and proportions between drawings.

[0011] <First Embodiment> Figure 1 is an exemplary cross-sectional view of the configuration of the electromachine 1 according to the first embodiment. As shown in Figure 1, the electromachine 1 comprises a housing 10, a rotor shaft 20, a rotor 30, a stator 40, an internal cooler 50, an external cooling device 60, two fans 70, and a plurality of fins 80.

[0012] For convenience, three mutually orthogonal directions are defined in the following explanation. The X direction is along the axial direction of the rotational axis Ax. The Y direction is along the direction perpendicular to the axial direction of the rotational axis Ax. The Z direction is along the depth direction of the housing 10, which is perpendicular to the X and Y directions. The X, Y, and Z directions are mutually orthogonal. Here, the rotational axis Ax is the central axis (centerline) of the rotor shaft 20 of the rotor 30. That is, the axial, radial, and circumferential directions of the rotational axis Ax are the same as the axial, radial, and circumferential directions of the rotor shaft 20. In the following explanation, unless otherwise specified, the axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions of the rotational axis Ax, i.e., the axial, radial, and circumferential directions of the rotor shaft 20.

[0013] The housing 10 is formed in a box shape. Inside the housing 10, a storage space S is provided. The housing 10 houses a part of the rotor shaft 20, the rotor 30, the stator 40, a part of the internal cooler 50, the fan 70, and the fins 80 in the storage space S. The housing 10 is also referred to as a frame.

[0014] The rotor shaft 20 extends in the axial direction of the rotation center axis Ax. The rotor shaft 20 penetrates the housing 10 and is supported by the housing 10 via a pair of bearings (not shown) so as to be rotatable around the rotation center axis Ax. The pair of bearings are provided at intervals in the axial direction. The bearings are, for example, sliding bearings, rolling bearings, or the like.

[0015] Both ends of the rotor shaft 20 in the axial direction protrude from the housing 10 toward the outside of the housing 10. A coupling portion 20a is provided at one end of the rotor shaft 20 in the axial direction. The coupling portion 20a is coupled to a coupling target (not shown).

[0016] The rotor 30 is attached to the rotor shaft 20. Therefore, the rotor 30 rotates around the rotation center axis Ax integrally with the rotor shaft 20 with respect to the housing 10. The rotor 30 has, for example, a core, a permanent magnet, windings, a cage, or other components according to the type of the electric machine 1.

[0017] The stator 40 has a stator core 41 and a stator winding 42. The stator core 41 is formed in a cylindrical shape around the rotation center axis Ax. The stator core 41 is fixed to the housing 10. The stator core 41 is provided on the radially outer side of the rotor 30. That is, the stator 40 is located on the radially outer side of the rotor 30.

[0018] The stator winding 42 extends in the axial direction in a slot (not shown) provided in the inner peripheral portion of the stator core 41 and is fixed to the stator core 41. The stator winding 42 penetrates the stator core 41 in the axial direction.

[0019] The stator winding 42 has a first winding end portion 45 and a second winding end portion 46. The first winding end portion 45 is one end portion of the stator winding 42 in the axial direction, and in FIG. 1, it is the end portion in the +X direction. The second winding end portion 46 is the other end portion of the stator winding 42 in the axial direction, and in FIG. 1, it is the end portion in the -X direction.

[0020] The first winding end portion 45 and the second winding end portion 46 are parts of the stator winding 42 that are located outside the stator core 41. The portion of the stator winding 42 between the first winding end portion 45 and the second winding end portion 46 is accommodated in the slots of the stator core 41. Therefore, the first winding end portion 45 and the second winding end portion 46 protrude outward from the end portion of the stator core 41 in the axial direction. The first winding end portion 45 and the second winding end portion 46 are integrated with the portion of the stator winding 42 that is accommodated in the slots.

[0021] When the electric machine 1 is driven, a current flows through the stator winding 42, causing the rotor 30 and the rotor shaft 20 to rotate around the rotation center axis Ax. At this time, the stator core 41 and the stator winding 42 become heat-generating bodies that generate heat.

[0022] The internal cooler 50 can cool the stator core 41 and the stator winding 42, which are heat-generating bodies, by exchanging heat with a heat medium such as purified water. The internal cooler 50 has a first binding ring 51, a second binding ring 52, a plurality of first cooling pipes 54, an inlet pipe 55i, and an outlet pipe 55o.

[0023] The first binding ring 51 and the second binding ring 52 are annular members formed hollow. The first binding ring 51 restrains the first winding end portion 45 outside the stator core 41. The second binding ring 52 restrains the second winding end portion 46 outside the stator core 41.

[0024] For example, the ends of multiple slots open at one end of the stator core 41 in the axial direction. The ends of the multiple slots are arranged in an annular shape around the rotational axis Ax. Multiple portions of the stator winding 42 that form the first winding end 45 protrude from each of the ends of the multiple slots to the outside of the stator core 41. That is, the first winding end 45 is formed in an annular shape around the rotational axis Ax.

[0025] The first binding ring 51 is attached to the first winding end 45 so as to surround the annularly formed first winding end 45 from the radially outer side. In other words, the first binding ring 51, which extends around the rotational axis Ax, restrains the first winding end 45. Therefore, the first binding ring 51 can, for example, prevent the first winding end 45 from bending radially outward due to electromagnetic force when the electric machine 1 is driven.

[0026] The second winding end 46, like the first winding end 45, is formed in an annular shape around the rotational axis Ax. The second binding ring 52 is attached to the second winding end 46 so as to surround the annularly formed second winding end 46 from the radially outer side, thereby restraining the second winding end 46.

[0027] In this embodiment, the first bind ring 51 and the second bind ring 52 are spaced apart in the axial direction from the stator core 41. Therefore, the first bind ring 51 and the second bind ring 52 can effectively prevent the first winding end 45 and the second winding end 46 from bending.

[0028] The first bind ring 51 is in contact with the first winding end 45. As a result, heat transfer occurs between the first winding end 45 and the first bind ring 51. The second bind ring 52 is in contact with the second winding end 46. As a result, heat transfer occurs between the second winding end 46 and the second bind ring 52.

[0029] If the first binding ring 51 and the second binding ring 52 are made of metal, an appropriate insulating material is interposed to prevent electrical conductivity with the first winding end 45 or the second winding end 46. This prevents electrical contact between the first binding ring 51 and the first winding end 45, and between the second binding ring 52 and the second winding end 46.

[0030] The cross-sections of the first bind ring 51 and the second bind ring 52 are, for example, circular. However, the cross-sections of the first bind ring 51 and the second bind ring 52 may also be rectangular. In this case, when the first bind ring 51 and the second bind ring 52 restrain the first winding end 45 or the second winding end 46, they can contact the first winding end 45 or the second winding end 46 over a wider area, thereby increasing the restraining force and heat transfer.

[0031] The portions of the first bind ring 51 and the second bind ring 52 that come into contact with the first winding end 45 or the second winding end 46 when restraining them may be processed to make those portions flat, thereby increasing the restraining force and heat transfer.

[0032] Each of the multiple first cooling tubes 54 is a hollow pipe. Each of the multiple first cooling tubes 54 penetrates the stator core 41 and connects the first binding ring 51 and the second binding ring 52. The multiple first cooling tubes 54 are fixed to the stator core 41. As a result, heat transfer occurs between each of the multiple first cooling tubes 54 and the stator core 41.

[0033] Figure 2 is an exemplary side view showing the first bind ring 51, the first cooling tubes 54, and the fins 80 of the first embodiment. As shown in Figure 2, the multiple first cooling tubes 54 are arranged at approximately equal intervals with spacing between them around the rotation axis Ax. The multiple first cooling tubes 54 extend in a substantially straight line between the first bind ring 51 and the second bind ring 52. Note that the first cooling tubes 54 are not limited to this example and may extend in a spiral shape, for example.

[0034] As shown in Figure 1, the inlet pipe 55i is connected to the first binding ring 51. The outlet pipe 55o is connected to the second binding ring 52. The inlet pipe 55i and the outlet pipe 55o are connected to the external cooling device 60 via pipes 90i and 90o, respectively, which are installed outside the housing 10.

[0035] A heat transfer medium flows through the first bind ring 51, the second bind ring 52, the multiple first cooling pipes 54, the inlet pipe 55i, and the outlet pipe 55o. The heat transfer medium can move between the first bind ring 51 and the second bind ring 52 through the first cooling pipes 54.

[0036] The external cooling device 60 is located outside the housing 10. In this embodiment, the external cooling device 60 is positioned at a distance from the housing 10. For example, the external cooling device 60 is positioned next to the housing 10. The external cooling device 60 may also be attached to the housing 10.

[0037] The external cooling device 60 cools the heat transfer medium discharged from the second bind ring 52 of the internal cooler 50 and supplies the heat transfer medium to the first bind ring 51 of the internal cooler 50. The external cooling device 60 includes a heat exchanger 61, a surge tank 62, a pump 63, two thermometers 65, and a flow meter 66. The external cooling device 60 is connected in series so that the heat transfer medium flowing in from the piping 90o passes through the thermometer 65o, flow meter 66, surge tank 62, pump 63, heat exchanger 61, and thermometer 65i in that order, and flows out from the piping 90i, thereby cooling the electromachine 1.

[0038] The thermometer 650 is provided to monitor the temperature of the heat transfer medium discharged from the electromachine 1 in order to check for any abnormalities in the electromachine 1. The flow meter 66 is provided to monitor the flow rate of the heat transfer medium in order to check for any leaks in the cooling channel, etc. The surge tank 62 is, heat medium Removal of residual air from inside the piping and heat mediumIt is provided to absorb the volume change due to temperature. Pump 63 generates a pressure difference, heat medium The water is circulated within the electrical machine 1. The heat exchanger 61 is connected to the outside air and outside water. heat medium By performing heat exchange heat medium To cool it. The thermometer 65i is discharged from the heat exchanger 61. heat medium By monitoring the temperature, it is possible to ensure that there are no abnormalities in the heat exchanger 61.

[0039] Figure 3 is an exemplary cross-sectional view showing the electromachine 1 with airflow generated by the fan 70 of the first embodiment. Figure 4 is an exemplary cross-sectional view showing the electromachine 1 with airflow generated by the fan 70 of the first embodiment along the line F4-F4 in Figure 3. In Figures 3 and 4, the arrows indicate the direction of the airflow generated by the fan 70.

[0040] As shown in Figure 1, one of the two fans 70 is located radially between the rotor shaft 20 and the first winding end 45, and axially between the stator core 41 and the first binding ring 51. The other of the two fans 70 is located radially between the rotor shaft 20 and the second winding end 46, and axially between the stator core 41 and the second binding ring 52.

[0041] The two fans 70 are mounted on the rotor shaft 20, aligned axially with the rotor core 31. Therefore, the rotor core 31 is located between the two fans 70. The two fans 70 rotate together with the rotor shaft 20.

[0042] In this embodiment, the fan 70 is a centrifugal fan. Therefore, as shown in Figure 3, the rotating fan 70 draws gas in the axial direction and generates an airflow directed radially outward. Thus, one of the two fans 70 generates an airflow directed toward the first winding end 45. The other of the two fans 70 generates an airflow directed toward the second winding end 46. In other words, the fan 70 rotates together with the rotor shaft 20, sending gas toward the stator windings 42 exposed from the stator core 41. Note that the fan 70 may be another type of fan, such as an axial flow fan.

[0043] At least one of the multiple fins 80 is located between the stator core 41 and the first bind ring 51 and is fixed to the first cooler tube 54, and further protrudes radially from the first cooler tube 54. The other multiple fins 80 are located between the stator core 41 and the second bind ring 52 and are fixed to the first cooler tube 54, and further protrude radially from the first cooler tube 54.

[0044] The multiple fins 80 are roughly annular plates arranged approximately perpendicular to the rotational axis Ax. That is, the fins 80 are arranged along the airflow generated by the fan 70. The fins 80 facilitate heat exchange between the airflow generated by the fan 70 and the heat transfer medium flowing through the first cooling pipe 54.

[0045] <Cooling action of electrical machine 1> The cooling operation of the electromachine 1 will be explained below with reference to Figure 1. First, water cooling using a heat transfer medium will be described. A heat transfer medium cooled from an external cooling device 60 is supplied to the inlet pipe 55i. The heat transfer medium then flows through the first bind ring 51, the first cooling pipe 54, and the second bind ring 52 in that order. At this time, the heat transfer medium cools the airflow generated by the fan 70, the stator core 41, and the stator windings 42 through heat exchange.

[0046] The heated heat transfer medium then returns to the external cooling device 60 from the outlet pipe 55i. The external cooling device 60 cools the heated heat transfer medium and supplies the cooled heat transfer medium back to the inlet pipe 55i. Through this cycle, the electromachine 1 is cooled by water cooling.

[0047] Next, we will explain air cooling by airflow. As shown in Figure 4, the airflow generated by the fan 70 is directed toward the first winding end 45 or the second winding end 46 that is exposed from the stator core 41. The airflow passes through the gaps between the multiple portions of the stator winding 42 that protrude from multiple slots and form the first winding end 45 or the second winding end 46. As a result, the first winding end 45 and the second winding end 46 are cooled by air cooling.

[0048] The airflow is heated by heat exchange with the first winding end 45 and the second winding end 46. After passing through the first winding end 45 or the second winding end 46, the airflow passes through the gaps between the multiple first cooling tubes 54. As a result, the airflow is cooled by heat exchange with the heat transfer medium flowing through the first cooling tubes 54. The cooled airflow is drawn in by the fan 70. The airflow circulates inside the containment space S by the cycle described above.

[0049] The airflow flows along the fins 80, exchanging heat with the heat transfer medium flowing through the first cooling tube 54. As a result, the airflow is cooled via the fins 80 and the first cooling tube 54. Meanwhile, the heat transfer medium flowing through the first cooling tube 54 is heated by the heat exchange.

[0050] In the above embodiment, the electromachine 1 comprises a housing 10, a rotor shaft 20, a rotor 30, a stator 40, an internal cooler 50, and an external cooling device 60. A housing space S is provided inside the housing 10. The rotor shaft 20 is supported by the housing 10 so as to extend axially and be rotatable. The rotor 30 is housed in the housing space S and attached to the rotor shaft 20. The stator 40 has a stator core 41 provided radially outside the rotor 30 and stator windings 42 that penetrate the stator core 41 axially, and is housed in the housing space S. The internal cooler 50 includes a first binding ring 51 which is hollow and restrains a first winding end 45, which is one end of the stator winding 42 in the axial direction, outside the stator core 41; a second binding ring 52 which is hollow and restrains a second winding end 46, which is the other end of the stator winding 42 in the axial direction, outside the stator core 41; and a hollow first cooling pipe 54 which penetrates the stator core 41 and connects the first binding ring 51 and the second binding ring 52. The external cooling device 60 is located outside the housing 10 and cools the heat transfer medium discharged from the internal cooler 50 and supplies the heat transfer medium to the internal cooler 50.

[0051] Conventionally, when a stator is air-cooled, a duct is provided in the housing that connects to the housing space to efficiently cool the stator using airflow generated by a fan. In this case, the housing becomes large. However, in the above configuration, the external cooling device 60 of this embodiment supplies the cooled heat transfer medium to the internal cooler 50.

[0052] As a result, the heat transfer fluid flows through the hollow first bind ring 51, the second bind ring 52, and the first cooling pipe 54. The heat transfer fluid flowing through the first bind ring 51 and the second bind ring 52 exchanges heat with the stator windings 42. Furthermore, the heat transfer fluid flowing through the first cooling pipe 54 exchanges heat with the stator core 41 through which the first cooling pipe 54 passes.

[0053] In this way, the stator 40 is efficiently cooled by exchanging heat with the heat transfer medium. Therefore, the electrical machine 1 of this embodiment does not require any components such as ducts connected to the housing space S. Furthermore, the first binding ring 51 and the second binding ring 52 that restrain the stator windings 42 are formed hollow so that the heat transfer medium can flow through them. Therefore, the electrical machine 1 of this embodiment does not require a separate component for the heat transfer medium that exchanges heat with the stator windings 42, in addition to the binding rings. In other words, the housing space S does not need to be expanded by adding such a component. The external cooling device 60 can be positioned at a distance from the housing 10. As described above, the electrical machine 1 of this embodiment can reduce the size of the housing 10 while maintaining cooling performance.

[0054] In this embodiment, the electromachine 1 further comprises a fan 70. The fan 70 is located radially between the rotor shaft 20 and the first winding end 45. The fan 70 is located axially between the stator core 41 and the first binding ring 51. The fan 70 is mounted on the rotor shaft 20. The fan 70 rotates with the rotor shaft 20 to generate an airflow directed toward the first winding end 45.

[0055] In the configuration described above, the fan 70 is located radially between the rotor shaft 20 and the first cooling pipe 54.

[0056] When the fan 70 generates an airflow directed toward the first winding end 45, this airflow absorbs heat from the first winding end 45 and cools it by coming into contact with the first cooling pipe 54. The cooled airflow circulates within the containment space S, is taken in by the fan 70, and returns to the first winding end 45. Through the above cycle, the first winding end 45 can be cooled more efficiently.

[0057] In this embodiment, the electromachine 1 further comprises fins 80. The fins 80 are located between the stator core 41 and the first binding ring 51 and protrude radially from the first cooling tube 54.

[0058] In other words, the fins 80 protrude from the first cooling tube 54 toward the fan 70. That is, the fins 80 extend in a direction along the airflow generated by the fan 70. Therefore, the airflow can be cooled more efficiently by the first cooling tube 54 via the fins 80. For this reason, the electromachine 1 of this embodiment can cool the stator 40 more efficiently.

[0059] <Second Embodiment> The outline and structure of the electromachine 1 according to the second embodiment will be described below. Figure 5 is a schematic perspective view showing the internal cooler 501 of the second embodiment. The same parts as in the first embodiment will not be described. The second embodiment is obtained by replacing the internal cooler 50 of the first embodiment with the internal cooler 501. In the second embodiment, each of the internal cooler 50 of the first embodiment is modified by replacing the first binding ring 51 with the first binding ring 511, replacing the second binding ring 52 with the second binding ring 521, replacing the multiple first cooling pipes 54 with multiple first cooling pipes 541 (first pipe 54a, second pipe 54b, and folded section 54c), and replacing the inlet pipe 55i and outlet pipe 55o with the inlet pipe 551i and outlet pipe 551o.

[0060] Although not shown in Figure 5, similar to the first embodiment, at least one of the multiple fins 80 is located between the stator core 41 and the first bind ring 511, and is attached to the first pipe 54a and the second pipe 54b, and further protrudes radially from these pipes. The other multiple fins 80 are located between the stator core 41 and the second bind ring 521, and is attached to the first pipe 54a and the second pipe 54b, and further protrudes radially from these pipes.

[0061] The inlet pipe 551i is connected to the external cooling device 60 via the piping 90i, and the outlet pipe 551o is connected to the external cooling device 60 via the piping 90o. As shown in Figure 5, the second binding ring 521 is provided with a first flow path 521a and a second flow path 521b.

[0062] The first channel 521a and the second channel 521b are located inside the second bind ring 521 and extend in a substantially annular shape. The diameter of the first channel 521a is larger than the diameter of the second channel 521b. The first channel 521a surrounds the second channel 521b. The first channel 521a is connected to the inlet pipe 551i. The second channel 521b is connected to the outlet pipe 551o. Note that the first channel 521a and the second channel 521b are not limited to this example.

[0063] In the second embodiment, each of the plurality of first cooling pipes 541 has a first pipe 54a, a second pipe 54b, and a folded portion 54c. The folded portion 54c is an example of a third pipe. One end of the first pipe 54a in the -X direction is connected to the first flow path 521a of the second binding ring 521, and the other end of the first pipe 54a in the +X direction is connected to one end of the folded portion 54c. The other end of the folded portion 54c is connected to one end of the second pipe 54b in the +X direction, and the other end of the second pipe 54b in the -X direction is connected to the second flow path 521b of the second binding ring 521. The folded portion 54c is formed within the first binding ring 511.

[0064] The external cooling device 60 supplies the heat transfer medium cooled by the heat exchanger 61 from the inlet pipe 551i to the first flow path 521a of the second bind ring 521. The heat transfer medium flows from the first flow path 521a into the first piping 54a of the multiple first cooling pipes 541. In the first piping 54a, the heat transfer medium flows from the second bind ring 521 toward the first bind ring 511.

[0065] The heat transfer fluid is folded back at the folded section 54c and flows into the second pipe 54b. In the second pipe 54b, the heat transfer fluid flows from the first bind ring 511 towards the second bind ring 521. The heat transfer fluid flows from the second pipe 54b into the second flow path 521b and returns to the external cooling device 60 from the outlet pipe 551o.

[0066] Each of the multiple first pipes 54a and second pipes 54b is a hollow pipe. Each of the multiple first pipes 54a and second pipes 54b passes through the stator core 41 and connects the first bind ring 511 and the second bind ring 521. The multiple first pipes 54a and second pipes 54b are fixed to the stator core 41. As a result, heat transfer occurs between each of the multiple first pipes 54a and second pipes 54b and the stator core 41, and the stator core 41 is cooled.

[0067] The first winding end 45 is constrained to the first binding ring 511, and the second winding end 46 is constrained to the second binding ring 521. Therefore, in the second embodiment, as in the first embodiment, heat transfer occurs between the first binding ring 511 and the first winding end 45, and between the second binding ring 521 and the second winding end 46, and the first winding end 45 and the second winding end 46 are cooled.

[0068] In the above embodiment, the external cooling device 60 supplies a heat transfer medium to the second bind ring 521. The first cooling pipe 541 has a first pipe 54a and a second pipe 54b. In the first pipe 54a, the heat transfer medium flows from the second bind ring 521 toward the first bind ring 511, and then, via the return section 54c, flows in the second pipe 54b toward the second bind ring 521.

[0069] In the configuration described above, the heat transfer medium flows through the first pipe 54a, then folds back at the return section 54c and flows through the second pipe 54b. As a result, in the heat transfer medium flowing through the first pipe 54a, the cooling efficiency of the stator core 41 near the second bind ring 521 is higher than the cooling efficiency of the stator core 41 near the first bind ring 511. On the other hand, in the heat transfer medium flowing through the second pipe 54b, the cooling efficiency of the stator core 41 near the first bind ring 511 is higher than the cooling efficiency of the stator core 521. Therefore, the electromachine 1 of this embodiment can mitigate the temperature gradient of the stator core 41 in the axial direction.

[0070] Alternatively, instead of the folded portion 54c provided on the first binding ring 551, the first binding ring 551 may be made into a hollow annular member, similar to the first embodiment, and the +X end of the first pipe 54a and the +X end of the second pipe 54b may be connected to this hollow portion.

[0071] <Third Embodiment> The outline and structure of the electromachine 1 according to the third embodiment will be described below. Figure 6 is an exemplary cross-sectional view of the configuration of the electromachine 1 according to the third embodiment. The differences from the first embodiment are as follows. As shown in Figure 6, in the third embodiment, the internal cooler 50 further includes a third binding ring 56, a fourth binding ring 57, a plurality of second cooling pipes 58, an inlet pipe 59i, and an outlet pipe 59o. The inlet pipe 59i is connected to the external cooling device 60 via piping 90i, similar to the inlet pipe 55i, and the outlet pipe 59o is connected to the external cooling device 60 via piping 90o, similar to the outlet pipe 55o. In addition, a plurality of fins 803 are provided instead of a plurality of fins 80.

[0072] The third bind ring 56 and the fourth bind ring 57 are hollow, annular members. The third bind ring 56 restrains the first winding end 45 outside the stator core 41. The fourth bind ring 57 restrains the second winding end 46 outside the stator core 41.

[0073] The third bind ring 56 and the fourth bind ring 57 are spaced axially apart from the stator core 41. The third bind ring 56 contacts and restrains the first winding end 45. As a result, heat transfer occurs between the first winding end 45 and the third bind ring 56. The fourth bind ring 57 also contacts and restrains the second winding end 46. As a result, heat transfer occurs between the second winding end 46 and the fourth bind ring 57.

[0074] If the third bind ring 56 and the fourth bind ring 57 are made of metal, an appropriate insulating material is interposed to prevent electrical conductivity with the first winding end 45 or the second winding end 46. This prevents electrical contact between the third bind ring 56 and the first winding end 45, and between the fourth bind ring 57 and the second winding end 46.

[0075] Furthermore, the cross-sections of the third bind ring 56 and the fourth bind ring 57 are, for example, circular. However, the cross-sections of the third bind ring 56 and the fourth bind ring 57 may also be rectangular. In this case, when the third bind ring 56 and the fourth bind ring 57 restrain the first winding end 45 or the second winding end 46, they can contact the first winding end 45 or the second winding end 46 over a wider area, thereby increasing the restraining force and heat transfer.

[0076] The portions of the third bind ring 56 and the fourth bind ring 57 that come into contact with the first winding end 45 or the second winding end 46 when restraining them may be processed to be flat, thereby increasing the restraining force and heat transfer.

[0077] Each of the multiple second cooling tubes 58 is a hollow pipe. Each of the multiple second cooling tubes 58 penetrates the stator core 41 and connects the third bind ring 56 and the fourth bind ring 57. The multiple second cooling tubes 58 are fixed to the stator core 41. As a result, heat transfer occurs between each of the multiple second cooling tubes 58 and the stator core 41.

[0078] A heat transfer medium flows through the third bind ring 56, the fourth bind ring 57, the multiple second cooling pipes 58, the inlet pipe 59i, and the outlet pipe 59o. The heat transfer medium can move between the third bind ring 56 and the fourth bind ring 57 through the second cooling pipes 58.

[0079] The inlet pipe 59i is connected to the fourth bind ring 57. The outlet pipe 59o is connected to the third bind ring 56. The inlet pipe 59i is connected to an external cooling device 60 (not shown in Figure 6) via piping 90i (not shown in Figure 6), and the outlet pipe 59o is connected to an external cooling device 60 (not shown in Figure 6) via piping 90o (not shown in Figure 6).

[0080] The external cooling device 60 supplies a heat transfer medium to the fourth bind ring 57 from the inlet pipe 59i. Furthermore, the external cooling device 60 cools the heat transfer medium discharged from the outlet pipe 59o of the third bind ring 56.

[0081] A heat transfer medium cooled from the external cooling device 60 is supplied to the inlet pipe 59i. The heat transfer medium then flows through the fourth bind ring 57, the second cooling pipe 58, and the third bind ring 56 in that order. At this time, the heat transfer medium cools the airflow generated by the fan 70, the stator core 41, and the stator windings 42 through heat exchange.

[0082] The heat transfer fluid, heated by heat exchange, returns to the external cooling device 60 through the outlet pipe 59i. The external cooling device 60 cools the heated heat transfer fluid and supplies the cooled heat transfer fluid back to the inlet pipe 59i. Through this cycle, the electromachine 1 is cooled by water cooling.

[0083] The first winding end 45 is constrained by both a first bind ring 51, which is supplied with a heat transfer medium cooled by the external cooling device 60, and a third bind ring 56, which discharges the heated heat transfer medium to the external cooling device 60. The second winding end 46 is constrained by both a fourth bind ring 57, which is supplied with a heat transfer medium cooled by the external cooling device 60, and a second bind ring 52, which discharges the heated heat transfer medium to the external cooling device 60.

[0084] Furthermore, the direction in which the heat transfer medium flows in the first cooling tube 54 and the direction in which the heat transfer medium flows in the second cooling tube 58 are opposite to each other. That is, the stator core 41, the first winding end 45, and the second winding end 46 are in approximately uniform contact with the cooling tubes through which the heat transfer medium cooled by the external cooling device 60 flows, thus mitigating the temperature gradient.

[0085] The multiple fins 803 have a structure substantially similar to that of the first embodiment, with at least one of the multiple fins 803 positioned between the stator core 41 and the first bind ring 51 and the third bind ring 56, and fixed to the first cooler tube 54 and the second cooler tube 58, and further projecting radially from these cooler tubes.

[0086] The other fins 803 are located between the stator core 41 and the second and fourth bind rings 52 and 57, and are fixed to the first and second coolers 54 and 58, and further protrude radially from these coolers.

[0087] Furthermore, although the above states that multiple fins 803 are fixed to both the first cooling tube 54 and the second cooling tube 58, some of the multiple fins 803 (on the +X direction side) are attached to the stator core 41. heat medium The first cooling tube 54 is fixed to the inlet side (+X direction side), and the other multiple fins 803 (-X direction) are fixed to the stator core 41. heat medium It is fixed to the second cooling tube 58 on the inlet side (-X direction) of the stator core 41. heat medium The first cooling tube 54 on the outlet side (-X direction) and the stator core heat medium The second cooling tube 58 on the outlet side (+X direction) and the fin 803 may be arranged so that they do not come into contact with each other, by having notches, slits, or through holes in the fin 803. That is, the airflow from the fan 70 is before heat exchange with the stator core 41. heat medium Because it is cooled solely by this method, the temperature of the airflow is further reduced, and the cooling efficiency of the electromachine 1 is further improved.

[0088] The other structures of the fin 803 are the same as in the first embodiment. With the above structure, the fin 803 facilitates heat exchange between the airflow generated by the fan 70 and the heat transfer medium flowing through the first cooling tube 54 and the second cooling tube 58.

[0089] In the above embodiment, the internal cooler 50 has a hollow third bind ring 56, a fourth bind ring 57, and a second cooling pipe 58. The third bind ring 56 restrains the first winding end 45 outside the stator core 41. The fourth bind ring 57 restrains the second winding end 46 outside the stator core 41. The second cooling pipe 58 penetrates the stator core 41 and connects the third bind ring 56 and the fourth bind ring 57. The external cooling device 60 supplies a heat transfer medium to the first bind ring 51 and cools the heat transfer medium discharged from the second bind ring 52. The external cooling device 60 supplies a heat transfer medium to the fourth bind ring 57 and cools the heat transfer medium discharged from the third bind ring 56.

[0090] In the configuration described above, the heat transfer fluid flows from the first bind ring 51 through the first cooling pipe 54 to the second bind ring 52. Furthermore, the heat transfer fluid flows from the fourth bind ring 57 through the second cooling pipe 58 to the third bind ring 56.

[0091] In other words, in the axial direction, the direction in which the heat transfer medium flows through the first cooling pipe 54 and the direction in which the heat transfer medium flows through the second cooling pipe 58 are opposite to each other. As a result, the electromachine 1 of this embodiment can mitigate the temperature gradient of the stator core 41 in the axial direction.

[0092] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0093] 1...Electrical machine, 10...Housing, 20...Rotor shaft, 30...Rotor, 40...Stator, 41...Stator core, 42...Stator winding, 45...First winding end, 46...Second winding end, 50, 501...Internal cooler, 51, 511...First binding ring, 52, 521...Second binding ring, 54, 541...First cooling tube, 54a...First piping, 54b...Second piping, 56...Third binding ring, 57...Fourth binding ring, 58...Second cooling tube, 60...External cooling device, 70...Fan, 80, 803...Fin.

Claims

1. A housing with an internal storage space, A rotor shaft that extends in the axial direction and is supported by the housing so as to be rotatable, A rotor housed in the aforementioned accommodation space and attached to the rotor shaft, A stator having a stator core provided radially outward from the rotor, and stator windings passing through the stator core in the axial direction, and housed in the housing space, An internal cooler comprising: a first binding ring which is hollow and restrains a first winding end, which is one end of the stator winding in the axial direction, outside the stator core; a second binding ring which is hollow and restrains a second winding end, which is the other end of the stator winding in the axial direction, outside the stator core; a first hollow cooling tube which penetrates the stator core and connects the first binding ring and the second binding ring; a third binding ring which is hollow and restrains the first winding end outside the stator core; a fourth binding ring which is hollow and restrains the second winding end outside the stator core; and a second hollow cooling tube which penetrates the stator core and connects the third binding ring and the fourth binding ring; An external cooling device is provided, which is located outside the housing and supplies a heat transfer medium to the first binding ring and cools the heat transfer medium discharged from the second binding ring, and supplies the heat transfer medium to the fourth binding ring and cools the heat transfer medium discharged from the third binding ring. An electrical machine equipped with the following features.

2. The external cooling device supplies the heat transfer medium to the second binding ring. The first cooling pipe comprises a first pipe connected to the second binding ring and a second pipe connected to the first pipe, wherein the heat transfer medium flows from the second binding ring toward the first binding ring in the first pipe and flows from the first binding ring toward the second binding ring in the second pipe. The electrical machine according to claim 1.

3. A fan, which is located between the rotor shaft and the first winding end in the radial direction and between the stator core and the first binding ring in the axial direction, is attached to the rotor shaft and rotates together with the rotor shaft to generate an airflow toward the first winding end. The electrical machine according to claim 1 or 2, further comprising:

4. A fin located between the stator core and the first binding ring and protruding radially from the first cooling tube, The electrical machine according to claim 3, further comprising:

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