Rotor for rotary electric machine and rotary electric machine

Abstract

To improve cooling performance of a rotor in a rotary electric machine.SOLUTION: A rotor for a rotary electric machine according to the present disclosure includes a rotor shaft that extends in an axial direction, a rotor core that surrounds the rotor shaft around an axis, and a plate-shaped plate that is disposed along an end surface of the rotor core, in which the rotor shaft includes an internal space through which a refrigerant flows and a discharge hole through which the refrigerant is discharged from the internal space, and the rotor core is a tubular body that surrounds a region of the rotor shaft in which the discharge hole is not formed around the axis, A guide groove extending from the discharge hole to the cooling hole is formed in a region sandwiched between the rotor core and the plate.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a rotor for a rotating electric machine and a rotating electric machine. [Background technology]

[0002] Rotating electric machines installed in electric vehicles and hybrid vehicles (including plug-in hybrid vehicles that allow external charging and external power supply) are usually configured to be able to cool the rotor that generates heat during operation. Specifically, a proposed configuration is one in which the coolant discharged from the rotor shaft is collected on the end face side of the rotor core, and then circulated through cooling holes formed in the rotor core (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5652638 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned configuration has the problem that cooling performance cannot be sufficiently improved. This is because, due to the structure in which the refrigerant accumulates on the end face side of the rotor core, i.e., around the cooling holes, the path that the refrigerant takes to reach the cooling holes is unstable, and the refrigerant that does reach the holes tends to stagnate around the cooling holes.

[0005] The present disclosure has been made to solve such problems, and its purpose is to improve the cooling performance of a rotor in a rotating electric machine. [Means for solving the problem]

[0006] The rotor for a rotating electric machine according to the present disclosure comprises a rotor shaft extending in the axial direction, a rotor core surrounding the rotor shaft around the axis, and a plate-shaped plate arranged along the end face of the rotor core, wherein the rotor shaft has an internal space for circulating a refrigerant and an outlet hole for discharging the refrigerant from the internal space, the rotor core is a cylindrical body surrounding an area of ​​the rotor shaft where the outlet hole is not formed around the axis, and has a cooling hole penetrating the cylindrical body in the axial direction, and a guide groove extending from the discharge hole to the cooling hole is formed in the area sandwiched between the rotor core and the plate. [Effects of the Invention]

[0007] In the rotor for a rotating electric machine according to the present disclosure, the formation of guide grooves extending from the discharge holes to the cooling holes improves the cooling performance of the rotor, because the refrigerant discharged from the discharge holes of the rotor shaft is guided by the guide grooves so that it can stably reach the cooling holes, and stagnation around the cooling holes is less likely to occur. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view of a rotating electric machine according to an embodiment of the present disclosure; [Figure 2] 1 is a front view of a rotating electric machine according to an embodiment of the present disclosure; [Figure 3] 2 is a cross-sectional view of a main part of a rotating electric machine according to an embodiment of the present disclosure (a view taken along the arrow AA in FIG. 2); [Figure 4] FIG. 1 is a front view of a rotor according to an embodiment of the present disclosure. [Figure 5] FIG. 1 is a front view of a main portion illustrating an intermediate plate and a guide groove according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0010] (1) Overall structure As shown in FIGS. 1 and 2, the rotating electric machine 100 includes a rotor (rotating electric machine rotor) 1 and a stator 2 fixed to the inside of a casing (not shown).

[0011] As shown in Figure 3, the rotor 1 comprises a rotor shaft 10 extending in the direction of a predetermined axis 3, a rotor core 20 surrounding the rotor shaft 10 around the axis 3, end plates 30 and intermediate plates 40 arranged along the end faces of the rotor core 20, and a guide groove 50 formed in the area between the rotor core 20 and the intermediate plate 40.

[0012] The rotor shaft 10 is a shaft body extending in the direction of an axis 3, and is formed with an internal space 11 for circulating the refrigerant and a discharge hole 13 for discharging the refrigerant from the internal space 11.

[0013] Of these, the internal space 11 extends in the direction of the axis 3 and reaches one end (the left end in FIG. 3; the same applies below) of the rotor shaft 10. The discharge hole 13 is formed as a hole that penetrates the rotor shaft 10 from the internal space 11 radially outward.

[0014] In this embodiment, a plurality of discharge holes 13 are formed at one end of the rotor shaft 10 at predetermined angular intervals around the axis 3 (more specifically, two discharge holes 13 at 180-degree intervals).

[0015] The rotor core 20 is a cylindrical body that surrounds the area of ​​the rotor shaft 10 where the discharge holes 13 are not formed around the axis 3, and has cooling holes 21 that penetrate the cylindrical body in the direction of the axis 3.

[0016] 4, the cooling holes 21 are formed in the rotor core 20 at positions adjacent to the plurality of magnets 23 that are arranged to surround the axis 3. As a result, a plurality of cooling holes 21 are provided at predetermined angular intervals around the axis 3.

[0017] In this embodiment, the end face of the rotor core 20 is divided at predetermined angular intervals around the axis 3 into a plurality of divided areas 25 (as a specific example, 10 divided at 36 degree intervals), and each of these divided areas 25 is provided with a plurality of cooling holes 21 (two in this embodiment).

[0018] The end plate 30 is a plate-shaped member arranged along the end face of the rotor core 20 on the side adjacent to the discharge hole 13 (left side in Figures 1 and 3), and the rotor shaft 10 passes through the center of the end plate 30 in the front-to-back direction.

[0019] The intermediate plate 40 is a plate-like member that is disposed between the rotor core 20 and the end plates 30, and the rotor shaft 10 passes through the center of the intermediate plate 40 in the front-to-back direction.

[0020] The guide groove 50 is formed as a groove that reaches from the discharge hole 13 to the cooling hole 21 in the region sandwiched between the rotor core 20 and the intermediate plate 40. In this embodiment, the guide groove 50 is formed as a groove that reaches from the surface of the intermediate plate 40 on the rotor core 20 side to the surface on the opposite side.

[0021] As shown in Figure 5(a), this guide groove 50 includes a surrounding groove 51 that is connected to the discharge hole 13 and expands to surround the rotor shaft 10 around the axis 3, and multiple branch grooves 53 that extend from the surrounding groove 51 to each of the cooling holes 21.

[0022] Of these, the branch grooves 53 have a larger cross-sectional area intersecting the extending direction of the groove as the angle difference between them around the axis 3 increases. In this embodiment, the cross-sectional area varies depending on the width of the groove (width around the axis).

[0023] Furthermore, the guide groove 50 may be provided with a connecting groove 55 that connects each of the branch grooves 53 around the axis 3 between the cooling hole 21 and the surrounding groove 51, as shown in FIG. 5(b).

[0024] Furthermore, as shown in Figure 5(c), the guide groove 50 may be configured to have a distribution groove 57 extending radially outward from the surrounding groove 51 for each partitioned region 25, and branch grooves 53 extending from the distribution groove 57 to each cooling hole 21 within the partitioned region 25.

[0025] Furthermore, as shown in FIG. 5(d), the guide groove 50 may have branch grooves 53 each having a curved, inclined shape toward the rotation direction of the rotor 1 (see the arrow in the figure).

[0026] In this configuration, as shown in Figure 5(e), the branch groove 53 may be shaped so that the greater the angle difference around the axis 3 with respect to the discharge hole 13, that is, the more distant the branch groove 53 that connects to the cooling hole 21 from the discharge hole 13, the smaller the inclination in the rotation direction of the rotor 1.

[0027] Furthermore, as shown in Figure 5(f), the guide groove 50 may be configured to have an extension groove 59 that extends radially outward from the surrounding groove 51 over the angular range of a predetermined number (three in this embodiment) of partition areas 25, and branch grooves 53 each extend from this extension groove 59 to the cooling hole 21.

[0028] (2) Action and Effects In the rotor 1 of the above embodiment, the formation of guide grooves 50 extending from the discharge holes 13 to the cooling holes 21 can improve the cooling performance of the rotor 1. This is because the refrigerant discharged from the discharge holes 13 of the rotor shaft 10 is guided by the guide grooves 50 and reaches the cooling holes 21 stably, and stagnation around the cooling holes 13 is less likely to occur.

[0029] Furthermore, in the rotor 1 of the above embodiment, the cooling holes 21 are formed in positions adjacent to the magnets 23 provided in the rotor core 20, so that the magnets 23 and their surrounding areas can be effectively cooled.

[0030] Furthermore, with the rotor 1 of the above embodiment, the refrigerant discharged from the discharge hole 13 can be circulated through the surrounding groove 51, i.e., around the rotor shaft 10, and then guided to each of the cooling holes 21 by the branch grooves 53. This makes it easier to prevent uneven distribution of the amount of refrigerant supplied from each of the branch grooves 53 to each of the cooling holes 21, allowing the entire rotor 1 to be cooled more effectively.

[0031] Furthermore, in the rotor 1 of the above embodiment, if the branch grooves 53 are configured so that the cross-sectional area increases as the angle between them and the discharge holes 13 increases around the axis 3, the branch grooves 53 that are further away from the discharge holes 13 and are relatively difficult for the refrigerant to reach have a larger cross-sectional area, making it easier for the refrigerant to flow through them. As a result, with this configuration, it becomes easier to prevent unevenness in the amount of refrigerant supplied to each cooling hole 21 by each branch groove 53, and the entire rotor 1 can be cooled more effectively.

[0032] Furthermore, in the rotor 1 of the above embodiment, if the branch grooves 53 are configured to be connected to each other by the connecting grooves 55, the refrigerant can circulate between adjacent branch grooves 53. This configuration makes it easier to prevent imbalances in the amount of refrigerant flowing through each branch groove 53, allowing the entire rotor 1 to be cooled more effectively.

[0033] Furthermore, in the rotor 1 of the above embodiment, if the guide grooves 50 are configured to include the extension grooves 59, the refrigerant discharged from the discharge holes 13 can flow through the extension grooves 59 of each partitioned region 25, and then be guided to each individual cooling hole 21 by the branch grooves 53. This makes it easier to prevent uneven distribution of the amount of refrigerant supplied from each branch groove 53 to each cooling hole 21, allowing the entire rotor 1 to be cooled more effectively.

[0034] (3) Variations Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple modifications described in this specification can be combined as needed.

[0035] For example, in the above embodiment, the rotor core 20 has the cooling holes 21 formed at positions adjacent to the magnets 23. However, the cooling holes 21 may be formed at positions other than the positions adjacent to the magnets 23.

[0036] In the above embodiment, the configuration in which two cooling holes 21 are provided in each of the segmented regions 25 has been exemplified. However, a configuration in which three or more cooling holes 21 are provided in each of the segmented regions 25 may also be used.

[0037] In the above embodiment, the guide groove 50 is formed on the intermediate plate 40 side. However, the guide groove 50 may be formed on the end face side of the rotor core 20, or may be formed on both the intermediate plate 40 and the rotor core 20.

[0038] In the above embodiment, the guide groove 50 includes the branch groove 53 that is curved and inclined toward the rotation direction of the rotor 1. However, the branch groove 53 may be curved and inclined toward the opposite direction to the rotation direction of the rotor 1.

[0039] In the above embodiment, the guide groove 50 is formed as a groove that reaches from the surface of the intermediate plate 40 facing the rotor core 20 to the opposite surface. However, the guide groove 50 may be formed as a groove of a predetermined depth that does not reach from the surface of the intermediate plate 40 facing the rotor core 20 to the opposite surface.

[0040] In the above embodiment, the branch grooves 53 have different cross-sectional areas depending on the width of the groove. However, the branch grooves 53 may have different cross-sectional areas depending on the depth of the groove, rather than the width of the groove. [Explanation of symbols]

[0041] 1...rotor, 2...stator, 3...axis, 10...rotor shaft, 11...internal space, 13...discharge hole, 20...rotor core, 21...cooling hole, 23...magnet, 25...partition area, 30...end plate, 40...intermediate plate, 50...guide groove, 51...encircling groove, 53...branch groove, 55...connecting groove, 57...distribution groove, 59...extension groove, 100...rotating electric motor

Claims

1. a rotor shaft extending in an axial direction; a rotor core that surrounds the rotor shaft around an axis; a plate-shaped plate disposed along an end surface of the rotor core, the rotor shaft includes an internal space through which a refrigerant flows and a discharge hole through which the refrigerant is discharged from the internal space, the rotor core is a cylindrical body that surrounds an area of ​​the rotor shaft where the discharge holes are not formed around the axis, and includes cooling holes that penetrate the cylindrical body in the axial direction, A guide groove extending from the discharge hole to the cooling hole is formed in the region sandwiched between the rotor core and the plate. Rotor for rotating electrical machine.

2. The cooling holes are formed at positions adjacent to the magnets provided in the rotor core. The rotor for a rotating electrical machine according to claim 1 .

3. a plurality of cooling holes are provided at predetermined angular intervals around the axis, the guide groove includes a surrounding groove that is connected to the discharge hole and expands to surround the rotor shaft around the axis, and a plurality of branch grooves that extend from the surrounding groove to each of the cooling holes. The rotor for a rotating electrical machine according to claim 1 .

4. the discharge hole is formed as a hole penetrating the rotor shaft from an internal space of the rotor shaft to a radially outer side, The larger the angle difference between each of the branch grooves and the discharge hole about the axis, the larger the cross-sectional area intersecting the direction in which the groove extends. The rotor for a rotating electrical machine according to claim 3 .

5. the guide groove includes a connecting groove that connects each of the branch grooves around the axis between the cooling hole and the surrounding groove. The rotor for a rotating electrical machine according to claim 3 .

6. a plurality of cooling holes are provided in each of the divided regions obtained by dividing the end face of the rotor core at predetermined angular intervals around the axis, the guide groove includes a distribution groove extending radially outward from the surrounding groove for each of the partitioned regions, and the branch grooves extend from the distribution groove to each of the cooling holes in the partitioned regions. The rotor for a rotating electrical machine according to claim 3 .

7. A rotating electric machine comprising the rotor for a rotating electric machine according to any one of claims 1 to 6.

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