Reluctance rotating electric machine

Abstract

To obtain a reluctance rotary electric machine having a new structure in which a leakage flux can be suppressed.SOLUTION: A rotor 12 of a reluctance rotary electric machine 10 has a shaft 14, a rotor core 50, and a fixation portion 60. The rotor core 50 has a plurality of plates 51. The fixation portion 60 has a first sandwich portion 12m and a second sandwich portion 61. The first sandwich portion 12m is provided on the shaft 14, and is positioned on one side of a tubular body 31 with respect to an axial direction. The second sandwich portion 61 is fixed to the shaft 14, and is positioned on the other side of the tubular body 31 with respect to the axial direction. The fixation portion 60 fixes the plurality of plates 51 to each other by sandwiching the tubular body 31 between the first sandwich portion 12m and the second sandwich portion 61.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a reluctance rotating electric machine. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is a reluctance rotating electric machine that includes a rotor core in which a plurality of annular plates are stacked in the axial direction around a central axis of rotation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-103103 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of reluctance rotating electrical machine, it would be beneficial if the generation of leakage magnetic flux could be suppressed, for example.

[0005] One example of a problem to be solved by the present invention is to provide a reluctance rotating electric machine with a novel configuration that can suppress leakage magnetic flux. [Means for solving the problem]

[0006] A reluctance rotating electric machine according to one embodiment of the present invention includes a stator and a rotor. A portion of the rotor is located inside the stator and is rotatable around a central axis of rotation. The rotor has a shaft, a rotor core, and a fixed portion. The shaft extends in the axial direction of the central axis of rotation. The rotor core is annular about the central axis of rotation and includes a plurality of plates stacked on top of each other in the axial direction. The fixed portion has a first clamping portion and a second clamping portion. The first clamping portion is provided on the shaft and located on one side of the rotor core in the axial direction. The second clamping portion is fixed to the shaft and located on the other side of the rotor core in the axial direction, and is connected to the first clamping portion via the shaft located inside the rotor core. The fixed portion clamps the rotor core between the first clamping portion and the second clamping portion, thereby fixing the plurality of plates to each other. The rotor core has a plurality of flux barrier groups spaced apart circumferentially around the central axis of rotation, and each of the flux barrier groups has a plurality of flux barriers that are convex radially inward of the central axis of rotation and are arranged at intervals in the radial direction, and the second clamping portion is provided for each flux barrier group, and when viewed from the axial direction, is located radially inward of the flux barrier groups and is arranged radially at the tops of the convex shapes of the flux barriers, reinforcing the rotor core. [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain a reluctance rotating electric machine with a novel configuration that can suppress leakage magnetic flux. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view that schematically shows a reluctance rotating electric machine according to an embodiment. [Figure 2] FIG. 2 is a front view schematically showing a stator and a rotor of the reluctance rotating electric machine according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view that schematically shows a part of the rotor of the reluctance rotating electric machine according to the embodiment. [Figure 4] FIG. 4 is a front view schematically showing a rotor of a reluctance rotating electric machine according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view that schematically shows a part of a rotor of a reluctance rotating electric machine of a comparative example. [Figure 6] FIG. 6 is a front view schematically showing a rotor of a reluctance rotating electric machine of a comparative example. [Figure 7] FIG. 7 is a front view schematically showing a rotor of a reluctance rotating electric machine according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments described below, as well as the actions and effects brought about by the configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0010] Furthermore, the drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may contain parts with different dimensional relationships and ratios. Furthermore, in this specification, ordinal numbers are used only to distinguish between parts, members, locations, positions, directions, etc., and do not indicate order or priority.

[0011] 1 is a cross-sectional view that schematically shows a reluctance rotating electric machine 10 according to an embodiment. The reluctance rotating electric machine 10 is, for example, a reluctance motor (electric motor). Note that the reluctance rotating electric machine 10 may also be a generator.

[0012] The reluctance rotating electric machine 10 includes a stator 11 , a rotor 12 , a housing 13 , and two bearings 15 .

[0013] For convenience, the terms axial direction, radial direction, and circumferential direction are defined herein. The axial direction is the direction along the central axis of rotation Ax. The radial direction is the direction perpendicular to the central axis of rotation Ax. The circumferential direction is the direction of rotation around the central axis of rotation Ax.

[0014] The central axis of rotation Ax is the center of rotation of the rotor 12 in the reluctance rotating electric machine 10, and is, for example, an imaginary line passing through the center of the shaft 14 of the rotor 12.

[0015] The housing 13 has a frame 41 and two bearing brackets 42. The frame 41 is formed in a substantially cylindrical shape surrounding the central rotation axis Ax. The stator 11 and a part of the rotor 12 are disposed inside the frame 41.

[0016] Two bearing brackets 42 are connected to both axial ends of the frame 41. The bearing brackets 42 close the internal space of the frame 41. Each of the bearing brackets 42 supports a corresponding bearing 15. The bearing brackets 42 are also referred to as walls.

[0017] The stator 11 has a stator core 21 and a stator winding 22. The stator core 21 is fixed to a frame 41.

[0018] FIG. 2 is a front view that schematically shows the stator 11 and rotor 12 of the reluctance rotating electric machine 10 of the embodiment.

[0019] 1 and 2, the stator core 21 is formed in a generally cylindrical shape surrounding the central axis of rotation Ax. The stator core 21 has a plurality of stator steel plates stacked on top of each other in the axial direction. The stator steel plates are, for example, electromagnetic steel plates and are made of a magnetic material.

[0020] As shown in Fig. 2, a plurality of teeth 21a are provided at intervals in the circumferential direction on the inner peripheral surface of the stator core 21. Slots 21b are formed between adjacent teeth 21a in the circumferential direction. The stator windings 22 are wound around the teeth 21a while being inserted into the slots 21b. Note that the stator windings 22 are not shown in Fig. 2.

[0021] 1 and 2, the rotor 12 has a shaft 14 and a cylindrical body 31. A portion of the rotor 12 is located inside the stator 11, and is rotatable around a central axis of rotation Ax.

[0022] 1, the shaft 14 is formed in a generally cylindrical shape extending along the central axis of rotation Ax. The shaft 14 passes through the bearing bracket 42 and extends between the inside and outside of the housing 13. The shaft 14 is supported by a bearing 15 so as to be rotatable around the central axis of rotation Ax.

[0023] The shaft 14 extends in the axial direction through the inside of the stator 11 and the cylindrical body 31. The shaft 14 is coupled to the cylindrical body 31.

[0024] The cylindrical body 31 is disposed inside the stator core 21. The cylindrical body 31 is formed in a substantially cylindrical shape surrounding the central axis of rotation Ax. That is, the cylindrical body 31 is provided with a hole 31a that passes through the cylindrical body 31 in the axial direction. The shaft 14 is inserted into the hole 31a.

[0025] The cylindrical body 31 has a rotor core 50 and two pressure plates 52. Note that the pressure plates 52 are not shown in Fig. 2. The pressure plates 52 are also called end plates.

[0026] The rotor core 50 is formed in a cylindrical shape around the central axis of rotation Ax. The rotor core 50 is provided with a hole 50a that passes through the rotor core 50 in the axial direction.

[0027] The rotor core 50 has a plurality of rotor steel plates 51. The rotor steel plates 51 are electromagnetic steel plates and are made of a magnetic material. The rotor steel plates 51 are annular about the central axis of rotation Ax. Specifically, the rotor steel plates 51 are disk-shaped. The thickness direction of the rotor steel plates 51 is along the axial direction. The plurality of rotor steel plates 51 are stacked in the axial direction. The plurality of rotor steel plates 51 are fixed to each other and integrated by fixing portions 60. The shaft 14 is placed inside the plurality of rotor steel plates 51. The rotor steel plates 51 are an example of plates. The rotor steel plates 51 are also called blanked plates.

[0028] Fig. 3 is a cross-sectional view that schematically shows a portion of the rotor 12 of the reluctance rotating electric machine 10 of the embodiment. As shown in Fig. 1 and Fig. 3, the two pressure plates 52 are pressure plate 52A and pressure plate 52B. Pressure plate 52A is located on one axial side (the right side in Figs. 1 and 3) of the rotor core 50 and overlaps with one of the multiple rotor steel plates 51 that is located at an end on one axial side. Pressure plate 52B is located on the other axial side (the left side in Figs. 1 and 3) of the rotor core 50 and overlaps with one of the multiple rotor steel plates 51 that is located at an end on the other axial side.

[0029] The presser plate 52 is annular about the central axis of rotation Ax. Specifically, the presser plate 52 is disk-shaped. The shaft 14 is placed inside the presser plate 52.

[0030] The two bearings 15 are located on one axial side and the other axial side of the cylindrical body 31. In other words, the cylindrical body 31 is located between the two bearings 15.

[0031] Next, a detailed description will be given of the shaft 14 and the cylindrical body 31. Fig. 4 is a front view schematically showing the rotor 12 of the reluctance rotating electric machine 10 according to the embodiment.

[0032] 3 and 4, the shaft 14 has a cylindrical outer peripheral surface 14a around the central rotation axis Ax. Also, as shown in Fig. 3, the shaft 14 has a plurality of columnar regions 14b to 14e around the central rotation axis Ax.

[0033] Region 14b is a portion of shaft 14 located inside cylindrical body 31. Region 14c is located on one axial side of region 14b and is connected to region 14b. The diameter of region 14c is larger than the diameter of region 14b. As a result, region 14c forms surface 12m that protrudes radially outward from region 14b. Surface 12m faces the other axial side, i.e., toward cylindrical body 31. Surface 12m is annular about central axis of rotation Ax.

[0034] Region 14d is located on the other axial side of region 14b and is connected to region 14b. The diameter of region 14d is smaller than the diameter of region 14b.

[0035] Region 14e is located on the other axial side of region 14d and is connected to region 14d. The diameter of region 14e is larger than the diameter of region 14d.

[0036] Between the region 14b and the region 14e, a recess 12n is provided, the bottom of which is the outer peripheral surface of the region 14d.

[0037] 4, a plurality of flux barrier groups 53 are provided on the rotor core 50 of the cylindrical body 31. The number of flux barrier groups 53 matches the number of poles of the rotor core 50 (for example, four).

[0038] The multiple flux barrier groups 53 are spaced apart in the circumferential direction. Each flux barrier group 53 has multiple flux barriers 53a. Each flux barrier 53a is a through-hole (hollow portion) that penetrates the rotor core 50 in the axial direction. In other words, the flux barriers 53a are openings provided in the rotor core 50. The flux barriers 53a are formed in a substantially arc shape so as to follow the flow of magnetic flux that is formed when current is applied to the stator winding 22. This results in the rotor core 50 having areas (directions) where magnetic flux flows easily and areas (directions) where magnetic flux does not flow easily. In FIG. 2, an example of the flow of magnetic flux is indicated by line L1. Note that the flux barriers 53a are not limited to the above. The flux barriers 53a may also be notches.

[0039] In the reluctance rotating electric machine 10, a rotational force can be generated by controlling the flow path of the magnetic flux using the flux barrier 53a. That is, the reluctance rotating electric machine 10 can rotate the rotor 12 by utilizing the saliency of the cylindrical body 31, without providing a permanent magnet or a winding (conductor) on the rotor 12.

[0040] 4, a recess 51b is provided in the inner peripheral portion 51a (inner peripheral surface) of each rotor steel plate 51. The recess 51b penetrates the rotor steel plate 51 in the axial direction and opens toward the inside in the radial direction of the shaft 14.

[0041] 3, the fixing portion 60 has a surface 12m of the shaft 14 and a key 61. The surface 12m is an example of a first clamping portion, and the key 61 is an example of a second clamping portion. The key 61 is also referred to as a clamping member.

[0042] The surface 12m is located on one axial side of the cylindrical body 31 (rotor steel plate 51). The surface 12m is aligned with one pressing plate 52A of the cylindrical body 31 in the axial direction and is in contact with the pressing plate 52A.

[0043] As shown in FIG. 4, multiple keys 61 are provided. The number of keys 61 is the same as the number of poles of the rotor core 50, for example, four. The multiple keys 61 are arranged at intervals in the circumferential direction. As shown in FIGS. 3 and 4, the keys 61 are formed, for example, in a rectangular parallelepiped shape. The keys 61 are inserted into the recesses 12n of the shaft 14 and fixed to the shaft 14 by welding or the like. The keys 61 are located on the other axial side of the cylindrical body 31 (rotor core 50). The keys 61 are aligned with the other pressing plate 52B of the cylindrical body 31 in the axial direction and are in contact with the pressing plate 52B. When viewed from the axial direction, the keys 61 are located radially inward of the flux barrier group 53. The keys 61 are located radially inward of a portion of the cylindrical body 31 that has relatively low rigidity (strength) due to the provision of the flux barrier group 53, thereby reinforcing the cylindrical body 31. The key 61 is connected to the surface 12m via the shaft 14 located inside the cylindrical body 31, that is, via the region 14b.

[0044] The fixing portion 60 secures the plurality of rotor steel plates 51 and the two presser plates 52 to one another by sandwiching the cylindrical body 31 (rotor core 50) in the axial direction between the surface 12m and the key 61. This integrates the plurality of rotor steel plates 51 and the two presser plates 52. The fixing portion 60 also determines the axial position of the cylindrical body 31 relative to the shaft 14. Here, the shaft 14 is press-fitted into the cylindrical body 31 (rotor core 50). That is, the cylindrical body 31 (rotor core 50) and the shaft 14 are fitted together by an interference fit.

[0045] 3, the portion 31c between the surface 12m and the key 61 in the cylindrical body 31 (rotor core 50) is solid. That is, the portion 51c between the surface 12m and the key 61 in each rotor steel plate 51, and the portion 52c between the surface 12m and the key 61 in each pressing plate 52 are solid. In other words, no hole penetrating the cylindrical body 31 is provided in the portion 31c between the surface 12m and the key 61 in the cylindrical body 31.

[0046] Next, a comparative example will be described. Fig. 5 is a cross-sectional view schematically showing a part of a rotor 112 of a reluctance rotating electric machine 110 of the comparative example. Fig. 6 is a front view schematically showing a rotor 112 of a reluctance rotating electric machine 110 of the comparative example.

[0047] As shown in FIGS. 5 and 6, a reluctance rotating electric machine 110 of the comparative example is different mainly in a cylindrical body 131 and a fixed portion 160 from the cylindrical body 31 and the fixed portion 60 of the embodiment.

[0048] The cylindrical body 131 of the comparative example is provided with a fixing through-hole 131a that passes through the cylindrical body 131 (rotor core 150 and presser plate 152) in the axial direction. The fixing portion 160 has a stud bolt 161 partially inserted into the fixing through-hole 131a and two nuts 162 coupled to both ends of the stud bolt 161. The fixing portion 160 secures the rotor core 150 to each other by sandwiching the rotor core 150 between the two nuts 162 connected by the stud bolt 161. In other words, the fixing portion 160 is not provided on the shaft 114. The rotor core 150 is provided with a flux barrier group 153, similar to the rotor core 50.

[0049] In the reluctance rotating electric machine 110 of the comparative example having the above configuration, the rotor core 150 is provided with the fixing through-holes 131a, which causes leakage magnetic flux to occur in the rotor core 150. In contrast, in the reluctance rotating electric machine 10 of this embodiment, the fixing portion 60 fixes the multiple rotor steel plates 51 and the two presser plates 52 to each other by sandwiching the cylindrical body 31 (rotor core 50) in the axial direction between the surface 12m and the key 61, and no hole penetrating the rotor core 50 is provided in the portion 31c of the cylindrical body 31 between the surface 12m and the key 61. Therefore, the reluctance rotating electric machine 10 of the embodiment suppresses the generation of leakage magnetic flux in the cylindrical body 31 compared to the reluctance rotating electric machine 110 of the comparative example.

[0050] As described above, the reluctance rotating electric machine 10 of this embodiment includes the stator 11 and the rotor 12. A portion of the rotor 12 is located inside the stator 11 and is rotatable around the central axis of rotation Ax. The rotor 12 includes a shaft 14, a rotor core 50, and a fixed portion 60. The shaft 14 extends in the axial direction of the central axis of rotation Ax. The rotor core 50 has a ring-shaped configuration around the central axis of rotation Ax and includes a plurality of rotor steel plates 51 stacked axially. The fixed portion 60 includes a surface 12m (first clamping portion) and a key 61 (second clamping portion). The surface 12m is provided on the shaft 14 and located on one side of the rotor core 50 in the axial direction. The key 61 is fixed to the shaft 14, located on the other side of the rotor core 50 in the axial direction, and connected to the surface 12m via the shaft 14, which is located inside the rotor core 50. The fixing portion 60 fixes the plurality of rotor steel plates 51 to each other by sandwiching the cylindrical body 31 between the surface 12m and the key 61.

[0051] According to this configuration, the fixing portion 60 fixes the plurality of rotor steel plates 51 to one another by clamping the rotor core 50 between the surface 12m (first clamping portion) provided on the shaft 14 and the key 61 (second clamping portion) fixed to the shaft 14, so there is no need to provide fixing through holes in the cylindrical body 31 to fix the plurality of rotor steel plates 51 to one another. This makes it possible to suppress the generation of leakage magnetic flux in the rotor core 50. This in turn makes it possible to improve the characteristics of the reluctance rotating electric machine 10, such as the power factor.

[0052] The first clamping portion is a surface 12m formed on the shaft 14 and facing the other side in the axial direction, and the second clamping portion is a key 61 fixed to the shaft 14.

[0053] According to this configuration, the first clip portion and the second clip portion can be provided relatively easily.

[0054] Here, the greater the number of poles in the rotor core 50, i.e., the greater the number of flux barrier groups 53, the lower the rigidity of the rotor core 50 and the more likely it is to expand in the axial direction. In contrast, in this embodiment, as described above, the same number of keys 61 as the number of poles of the rotor core 50 is provided. Therefore, according to this embodiment, deformation of the cylindrical body 31 can be suppressed compared to a configuration in which the number of keys 61 is fewer than the number of poles of the rotor core 50.

[0055] Further, an inner peripheral portion 51a of each rotor steel plate 51 is provided with a recess 51b that penetrates the rotor steel plate 51 in the axial direction and opens toward the inside in the radial direction of the shaft 14. The recesses 51b of the multiple rotor steel plates 51 are aligned in the axial direction.

[0056] According to this configuration, when stacking multiple rotor steel plates 51 in the axial direction, by inserting a jig member extending in the axial direction into each recess 51b, the circumferential positions of the multiple rotor steel plates 51 can be easily aligned in the circumferential direction. Furthermore, since the recesses 51b are provided on the inner peripheral portion 51a of the rotor steel plates 51, the recesses 51b can be separated from the magnetic flux. Therefore, leakage magnetic flux in the cylindrical body 31 can be suppressed.

[0057] Next, a modified example of this embodiment will be described. Fig. 7 is a front view that schematically shows a rotor 12 of a reluctance rotating electric machine 10 according to a modified example of this embodiment.

[0058] 7, the rotor core 50 has six magnetic poles and the fixed portion 60 has six keys 61. That is, the number of keys 61 provided is the same as the number of poles of the rotor core 50.

[0059] In the above embodiment, an example has been shown in which the first clamping portion of the fixing portion 60 is the surface 12m formed on the shaft 14, but this is not limiting. For example, the first clamping portion may be a member such as a key fixed to the shaft 14, similar to the second clamping portion (key 61).

[0060] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0061] 10... reluctance rotating electric machine, 11... stator, 12... rotor, 12m... surface (first clamping portion), 14... shaft, 50... rotor core, 51... rotor steel plate (plate), 51a... inner periphery, 51b... recess, 53...Flux barrier group, 53a...Flux barrier, 60...fixed portion, 61...key (second clamping portion), Ax...rotation center axis.

Claims

1. A stator; a rotor, a portion of which is located inside the stator and which is rotatable around a central axis of rotation; Equipped with The rotor is a shaft extending in the axial direction of the rotation center axis; a rotor core having a plurality of plates that are annular around the central axis of rotation and stacked on top of each other in the axial direction; a fixing portion including a first clamping portion provided on the shaft and positioned on one side of the rotor core in the axial direction, and a second clamping portion fixed to the shaft and positioned on the other side of the rotor core in the axial direction, and connected to the first clamping portion via the shaft positioned inside the rotor core, wherein the first clamping portion and the second clamping portion clamp the rotor core to fix the plurality of plates to each other; and a plurality of flux barrier groups are provided in the rotor core at intervals in the circumferential direction of the central axis of rotation, each of the flux barrier groups includes a plurality of flux barriers that are each convex toward an inner side in a radial direction of the rotation central axis and are arranged at intervals from each other in the radial direction; the second clamping portions are provided for each of the flux barrier groups, and when viewed from the axial direction, are positioned radially inward of the flux barrier groups, are aligned radially with the tops of the convex shapes of the flux barriers, and reinforce the rotor core. Reluctance rotating electric machine.

2. the first clamping portion is a surface formed on the shaft and facing the other side in the axial direction, The second clamping portion is a key fixed to the shaft.

2. A reluctance rotating electric machine according to claim 1.

3. The number of the second clamping portions is the same as the number of poles of the rotor core.

2. A reluctance rotating electric machine according to claim 1.

4. A recess is provided on an inner peripheral portion of each of the plates, the recess penetrating the plate in the axial direction and opening toward the inside in the radial direction of the shaft, The recesses of the plurality of plates are aligned in the axial direction.

4. A reluctance rotating electric machine according to claim 1.

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