Rotary electric machine, compressor, air blower and freezer

Abstract

To provide a technique that can suppress magnetic flux that does not contribute to the output of a rotating electric machine in a rotor core using an integrally molded powder magnetic core.SOLUTION: A rotary electric machine 1 according to an embodiment of the present disclosure includes a stator 10 and a rotor 20 that is rotatable about a rotation axis AX and includes a rotor core 21 that is a powder magnetic core compressed and molded as an integral unit. The rotor core 21 is provided with a hole 28A that penetrates the entire range between one end and the other end in the axial direction, and, when viewed along the axial direction, includes iron core portions 23 and 24 in which the entire axial range is composed of an iron core, and an iron core portion 25 which is adjacent to the iron core portions 23 and 24 and the hole 28A, in which a part of the entire axial range is composed of an iron core and a hole 28B is provided in another part adjacent in the axial direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, the rotor core of a rotating electric machine may be provided with holes such as slits that function as slots for magnets in an embedded magnet type rotating electric machine or flux barriers (magnetic barriers) in a synchronous reluctance machine.

[0003] From the viewpoint of suppressing leakage flux of the embedded magnet, a flux barrier may be provided at the end of the magnet slot in the direction perpendicular to the main magnetic flux of the magnet. And, when viewed along the axial direction, it is desirable that both ends of the hole including the magnet slot and the flux barrier penetrate radially outward or inward. Also, from the viewpoint of function, it is desirable that both ends of the slit of the synchronous reluctance machine are open radially outward when viewed along the axial direction. However, when viewed along the axial direction, if both ends of the hole provided in the rotor core are open radially outward or inward, the rotor core may be divided into multiple members. Therefore, from the viewpoint of cost and manufacturing constraints, a bridge portion may be provided to connect the parts that are originally divided by the hole portion. In this case, the bridge portion functions as a passage for magnetic flux that does not contribute to the output of the rotating electric machine, such as short-circuit magnetic flux of the embedded magnet and magnetic flux acting from the stator.

[0004] For example, Patent Document 1 discloses a technique for minimizing bridge portions in a rotor core formed as a laminate of electromagnetic steel sheets, thereby suppressing magnetic flux that does not contribute to the output of a rotating electric machine. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-254403 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the case of a rotor core using an integrally molded powder magnetic core, technology that is based on a rotor core configured as a laminate of electromagnetic steel sheets cannot be adopted as is.

[0007] An object of the present disclosure is to provide a technique capable of suppressing magnetic flux that does not contribute to the output of a rotating electric machine in a rotor core that uses an integrally molded powder magnetic core. [Means for solving the problem]

[0008] In a first aspect of the present disclosure, A stator; A rotor that is rotatable about a rotation axis and includes a rotor core that is a powder magnetic core that is integrally compression molded, The rotor core includes a first core portion having a first gap portion penetrating the entire range between one end and the other end in the axial direction, and the entire range in the axial direction being an iron core when viewed along the axial direction, and a second core portion adjacent to the first core portion and the first gap portion, a portion of the entire range in the axial direction being an iron core, and a second gap portion being provided in another portion adjacent to the first core portion in the axial direction. A rotating electric machine is provided.

[0009] According to the first aspect of the present disclosure, in the rotor core, a second core portion corresponding to a bridge portion is provided only in a portion in the axial direction of the rotating electric machine, and a second gap portion adjacent to the first gap portion corresponding to a magnet slot, slit, or the like is provided in the other portion in the axial direction. Therefore, even if the rotor core is separated into two parts by the first gap portion and the second gap portion in one axial cross section, a structure can be realized in which the two separated parts are connected by the second core portion in another cross section. As a result, the rotor core is not separated into a plurality of parts, and in the rotor core which is a powder magnetic core molded as an integral part, the second core portion corresponding to the bridge portion can be limited to only a portion in the axial direction of the rotating electric machine. Therefore, the rotating electric machine can suppress the magnetic flux that does not contribute to the output of the rotating electric machine in the rotor core using the powder magnetic core molded as an integral part.

[0010] In addition, in a second aspect of the present disclosure, based on the first aspect described above, When viewed in the axial direction, the area of ​​the second core portion may be equal to or less than one tenth of the area of ​​the first core portion.

[0011] In addition, in a third aspect of the present disclosure, on the premise of the first or second aspect described above, The second core portion may be integral with a continuous portion of the entire axial extent of the rotor core.

[0012] In addition, in a fourth aspect of the present disclosure, on the premise of any one of the first to third aspects described above, the rotor core includes two first core portions separated by the first gap portion or the second gap portion, The second core portion may connect the two first core portions to each other at an end portion in a direction perpendicular to a direction in which the two first core portions face each other.

[0013] In addition, in a fifth aspect of the present disclosure, on the premise of any one of the first to fourth aspects described above, the rotor core includes two first core portions separated by the first gap portion or the second gap portion, The second core portion may connect the two first core portions to each other at a center portion in a direction perpendicular to a direction in which the two first core portions face each other.

[0014] In addition, in a sixth aspect of the present disclosure, on the premise of any one of the first to fifth aspects described above, The second core portion may be provided in an intermediate portion between one end and the other end in the axial direction of the rotor core.

[0015] In addition, in a seventh aspect of the present disclosure, on the premise of any one of the first to sixth aspects described above, The second core portion may be provided in a partial range starting from one end of the entire range in the axial direction of the rotor core.

[0016] In addition, in an eighth aspect of the present disclosure, on the premise of any one of the first to seventh aspects described above, the rotor core includes two of the second core portions, The two second core portions may be arranged in an axial direction so as not to overlap each other.

[0017] In addition, in a ninth aspect of the present disclosure, on the premise of any one of the first to seventh aspects described above, the rotor core includes two of the second core portions, The two second core portions may be arranged in an overlapping range in the axial direction.

[0018] In addition, in a tenth aspect of the present disclosure, on the premise of any one of the first to ninth aspects described above, the second gap portion is provided in an axial range extending from one end of the rotor core to the second core portion, The rotor core may further include a holding member that holds the first core portion from the outside in the axial direction at one axial end portion of the rotor core where the second gap portion is provided.

[0019] In addition, in an eleventh aspect of the present disclosure, on the premise of any one of the first to tenth aspects described above, The second core portion may have a thickness of 1 mm or more when viewed in the axial direction.

[0020] In addition, in a twelfth aspect of the present disclosure, on the premise of any one of the first to eleventh aspects described above, the rotor core includes two first core portions circumferentially divided by the first gap portion, The two first core portions are formed with magnetic poles partitioned by the first gap portion. The two first core portions may be connected by the second core portion.

[0021] In addition, in a thirteenth aspect of the present disclosure, based on the above-mentioned twelfth aspect, The second core portion may be provided adjacent to the first gap portion.

[0022] In addition, in a fourteenth aspect of the present disclosure, on the premise of any one of the first to thirteenth aspects described above, A permanent magnet is disposed in the first gap. It may be an embedded magnet type rotating electric machine.

[0023] In addition, in a fifteenth aspect of the present disclosure, on the premise of any one of the first to thirteenth aspects described above, The motor may be a synchronous reluctance machine in which the first air gap, or a member arranged in the first air gap and having a lower magnetic permeability than the rotor core, functions as a magnetic barrier.

[0024] In addition, in a sixteenth aspect of the present disclosure, A rotating electric machine according to any one of the first to fifteenth aspects described above is mounted. A compressor is provided.

[0025] In addition, in a seventeenth aspect of the present disclosure, A rotating electric machine according to any one of the first to fifteenth aspects described above is mounted. A blower is provided.

[0026] In addition, in an eighteenth aspect of the present disclosure, A rotating electric machine according to any one of the first to fifteenth aspects described above is mounted. A refrigerator is provided. Effect of the Invention

[0027] According to the above-described embodiment, it is possible to suppress magnetic flux that does not contribute to the output of a rotating electric machine in a rotor core using an integrally molded powder magnetic core. [Brief description of the drawings]

[0028] [Figure 1] 1 is a cross-sectional view showing a first example of a cross section of a rotating electric machine according to a first embodiment. [Diagram 2] 4 is a cross-sectional view showing a second example of a cross section of the rotating electric machine according to the first embodiment. FIG. [Diagram 3] 2 is a diagram illustrating a first example of a rotor of the rotating electric machine according to the first embodiment. FIG. [Figure 4] FIG. 4 is a diagram showing a rotor according to a first comparative example. [Diagram 5] 4 is a cross-sectional view showing a third example of a cross section of the rotating electric machine according to the first embodiment. FIG. [Figure 6] 5 is a diagram showing a second example of the rotor of the rotating electric machine according to the first embodiment. FIG. [Figure 7] 5A to 5C are diagrams illustrating a third example of the rotor of the rotating electric machine according to the first embodiment. [Figure 8] 5A to 5C are diagrams illustrating a fourth example of the rotor of the rotating electric machine according to the first embodiment. [Figure 9] 6A to 6C are diagrams illustrating a fifth example of the rotor of the rotating electric machine according to the first embodiment. [Figure 10]4 is a cross-sectional view showing a fourth example of a cross section of the rotating electric machine according to the first embodiment. FIG. [Figure 11] 10 is a cross-sectional view showing a fifth example of a cross section of the rotating electric machine according to the first embodiment. FIG. [Figure 12] 13 is a vertical cross-sectional view showing an eighth example of the rotor of the rotating electric machine according to the first embodiment. FIG. [Figure 13] 10 is a cross-sectional view showing a first example of a cross section of a rotating electric machine according to a second embodiment. FIG. [Figure 14] FIG. 11 is a cross-sectional view showing a second example of a cross section of a rotating electric machine according to a second embodiment. [Figure 15] FIG. 11 is a vertical cross-sectional view showing a first example of a rotor according to a second embodiment. [Figure 16] FIG. 11 is a diagram showing a rotor according to a second comparative example. [Figure 17] FIG. 11 is a cross-sectional view showing a third example of a cross section of the rotating electric machine according to the second embodiment. [Figure 18] FIG. 11 is a vertical cross-sectional view showing a second example of a rotor according to a second embodiment. [Figure 19] FIG. 11 is a vertical cross-sectional view showing a third example of the rotor according to the second embodiment. [Figure 20] FIG. 11 is a vertical cross-sectional view showing a fourth example of the rotor according to the second embodiment. [Figure 21] 13 is a diagram showing a fifth example of a rotor according to the second embodiment. FIG. [Figure 22] FIG. 11 is a cross-sectional view showing a first example of a cross section of a rotating electric machine according to a third embodiment. [Diagram 23] FIG. 11 is a cross-sectional view showing a second example of a cross section of a rotating electric machine according to a third embodiment. [Figure 24] FIG. 11 is a vertical cross-sectional view showing a first example of a rotor according to a third embodiment. [Diagram 25] FIG. 13 is a diagram showing a rotor according to a third comparative example. [Figure 26] FIG. 13 is a diagram showing a rotor according to a fourth comparative example. [Figure 27] FIG. 11 is a vertical cross-sectional view showing a second example of a rotor according to a third embodiment. [Figure 28] FIG. 1 is a diagram showing an example of an air conditioner equipped with a rotating electric machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment will be described with reference to the drawings.

[0030] [First embodiment] A rotating electric machine 1 according to a first embodiment will be described with reference to FIGS. 1 to 12.

[0031] <First example of a rotating electrical machine> Fig. 1 is a cross-sectional view showing a first example of a cross section of the rotating electric machine 1 according to the first embodiment. Fig. 2 is a cross-sectional view showing a second example of a cross section of the rotating electric machine 1 according to the first embodiment. Fig. 3 is a diagram showing a first example of a rotor 20 of the rotating electric machine 1 according to the first embodiment. Specifically, Fig. 3 is a diagram showing the rotating electric machine 1 as viewed from an arrow α in Figs. 1 and 2. Fig. 4 is a diagram showing a rotor 20c according to a first comparative example.

[0032] The cross section of the rotating electric machine 1 refers to a cross section taken along a plane perpendicular to the rotation axis AX of the rotating electric machine 1.

[0033] As shown in FIGS. 1 to 3, in this example, a rotating electric machine 1 includes a stator 10, a rotor 20, and a rotating shaft 30.

[0034] The rotating electric machine 1 according to the first embodiment is a rotary electric motor, and is mounted on, for example, a compressor or a blower of an air conditioner (one example of a refrigeration device) to drive the compressor or the blower. The same may be true for the rotating electric machines 1 according to the second and third embodiments described below.

[0035] 1 and 2, the rotating electric machine 1 according to the first embodiment is a radial gap type in which a stator 10 and a rotor 20 face each other via a gap (also referred to as an "air gap") in a radial direction (hereinafter simply referred to as "radial direction") based on a rotation axis AX. In addition, the rotating electric machine 1 according to the first embodiment is an interior permanent magnet (IPM) type in which a permanent magnet 22 is embedded in a rotor core 21, as described later.

[0036] The stator 10 is disposed on the radially outer side (outer periphery side) of the rotating electric machine 1, and is fixed to a fixed portion such as a housing (not shown). The stator 10 includes a stator core (also referred to as a "stator core") 11 and a winding (also referred to as a "coil") 12.

[0037] The stator core 11 is formed of a ferromagnetic material such as, for example, an electromagnetic steel sheet, a powder magnetic core, etc. The stator core 11 includes a back yoke portion 13 having a substantially cylindrical shape centered on the rotation axis AX, and a plurality of teeth portions 14 (24 in this example) protruding radially inward from the inner peripheral surface of the back yoke portion 13.

[0038] Incidentally, the term "abbreviated" is intended to allow for manufacturing errors and the like, and will be used in the same sense hereinafter.

[0039] The teeth 14 are arranged at approximately equal intervals in a circumferential direction (hereinafter simply referred to as "circumferential direction") based on the rotation axis AX on the inner peripheral surface of the back yoke portion 13. A winding slot (also referred to as "coil slot") for accommodating the winding 12 is formed between two adjacent teeth 14 in the circumferential direction. In this example, 24 winding slots are formed.

[0040] The winding 12 is wound, for example, by a distributed winding method so as to straddle two or more of the teeth 14 included in the plurality of teeth 14. The winding 12 may also be wound around each of the plurality of teeth 14 by a concentrated winding method. An insulating member, for example, a PET insulating film, is interposed between the winding 12 and the inner circumferential surface of the back yoke portion 13 or between the winding 12 and the teeth 14 to insulate the winding 12 from the stator core.

[0041] The rotor 20 is disposed facing the inside of the stator 10 in the radial direction. The rotor 20 is fixed to a rotating shaft 30 and is rotatable about a rotating axis AX. The rotor 20 includes a rotor core 21 and a plurality of permanent magnets 22.

[0042] Among the components of the rotor 20, the rotor core 21 is a component that functions as a magnetic path for the magnetic flux due to the armature current flowing through the windings 12 of the stator 10 and as a magnetic path for the magnetic field of the permanent magnets 22. The rotor core 21 is a powder magnetic core that is compression molded as a single unit. The rotor core 21 has a substantially cylindrical shape centered on the rotation axis AX, and is provided with a through hole that penetrates in the axial direction centered on the rotation axis AX. The rotating shaft 30 is inserted into the through hole, and the rotor core 21 is fixed to the rotating shaft 30. Here, "compression molded as a single unit" means that the rotor core 21 is not divided into multiple pieces, but is molded as a single unit in a mold, and is intended to exclude a form in which multiple rotor cores 21 molded in a mold are joined together.

[0043] Each of the multiple (four in this example) permanent magnets 22 is embedded in the rotor core 21. The permanent magnets 22 are, for example, ferrite magnets or neodymium magnets. The multiple permanent magnets 22 are arranged at equal intervals in the circumferential direction at predetermined radial positions of the rotor core 21. The permanent magnets 22 may be sintered magnets or bonded magnets. In the latter case, for example, the permanent magnets 22 may be molded integrally with the rotor core 21 by injection molding or the like.

[0044] 1 and 2, each of the permanent magnets 22 has a generally rectangular shape with one side sufficiently longer than the other sides when viewed along the axial direction, and is arranged so that the long side is perpendicular to the radial direction (hereinafter simply referred to as the "radial direction") based on the rotation axis AX at approximately the center. Each of the permanent magnets 22 is magnetized so that both ends in the short side direction have magnetic poles (N pole and S pole) with different polarities from each other.

[0045] The multiple permanent magnets 22 are each arranged such that the magnetic pole magnetized on the surface facing the stator 10 is different from that of the other circumferentially adjacent permanent magnets 22. For example, when a surface of one permanent magnet 22 facing the stator 10 is magnetized with an S pole, another permanent magnet 22 adjacent to the one permanent magnet 22 in the circumferential direction is magnetized with an N pole on the surface facing the stator 10.

[0046] The rotating shaft 30 is attached to the rotor 20 so that its axis substantially coincides with the rotation axis AX. The rotating shaft 30 is, for example, a member longer in the axial direction than the rotor 20, and both ends in the axial direction are disposed so as to protrude outward from both ends in the axial direction of the rotor 20. Both ends of the rotating shaft 30 are rotatably supported by a fixed part such as a housing of the rotating electric machine 1 via a bearing or the like. This allows the rotor 20 fixed to the rotating shaft 30 to rotate relative to a fixed part of the rotating electric machine 1 such as the stator 10. The rotating shaft 30 may also be disposed so as to protrude outward from only one end of both ends in the axial direction of the rotor 20, and only the one end may be rotatably supported by a fixed part such as a housing of the rotating electric machine 1 via a bearing or the like.

[0047] 1 and 2, rotor core 21 includes core portions 23 to 26. Rotor core 21 is also provided with holes 27 to 29.

[0048] As shown in FIG. 3, in this example, rotor core 21 has the cross-sectional shape of FIG. 1 in range 301 of the entire axial range, and has the cross-sectional shape of FIG. 2 in the remaining axial range 302.

[0049] The holes 27 correspond to slots (magnet slots) in which the permanent magnets 22 are embedded. The holes 27 are provided so as to penetrate the rotor core 21 in the axial direction. This allows the permanent magnets 22 to be arranged over almost the entire range of the rotor core 21 in the axial direction.

[0050] Hole 28 is provided adjacent to the counterclockwise end of hole 27 in the circumferential direction in the figure. Hole 29 is provided adjacent to the clockwise end of hole 27 in the circumferential direction in the figure. Holes 28 and 29 correspond to flux barriers for suppressing short-circuiting of magnetic flux at the end of permanent magnet 22 in a direction perpendicular to the main magnetic flux.

[0051] Core portion 23 is a radially inner portion of rotor core 21 defined by holes 27-29. Core portion 24 is a radially outer portion of rotor core 21 defined by holes 27-29.

[0052] As shown in FIGS. 2 and 3, the holes 28 include holes 28A and 28B, and penetrate and open to the outer peripheral surface of the rotor core 21 on the radially outer side in an axial range 302.

[0053] When viewed along the axial direction, hole portion 28A is adjacent to hole portion 27, and hole portion 28B is adjacent to hole portion 28B and penetrates the radially outer outer peripheral surface of rotor core 21.

[0054] 1 and 3, in axial range 301, hole 28 does not penetrate the outer peripheral surface on the radial outside of rotor core 21, and only hole 28A of holes 28A and 28B is provided. In other words, hole 28A penetrates the entire axial range of rotor core 21, while hole 28B is provided only in range 302 that corresponds to a part of the entire axial range of rotor core 21, based on one axial end.

[0055] 1 and 3, in the axial range 301, iron core portion 25 corresponding to the bridge portion between iron core portions 23, 24 is provided at a location corresponding to hole portion 28B. This allows iron core portion 25 to connect iron core portions 23, 24 on the radial outside of hole portion 28A. Therefore, in the axial range 302, a state in which hole portion 28 penetrates the outer peripheral surface on the radial outside of rotor core 21 can be achieved, while ensuring appropriate strength of rotor core 21.

[0056] When viewed along the axial direction, it is desirable that the area of ​​core portion 25 is sufficiently small compared to the areas of core portions 23 and 24. This is because, as described below, core portion 25 serves as a path for leakage magnetic flux of permanent magnet 22 that does not contribute to the output of rotating electric machine 1. For example, when viewed along the axial direction, it is desirable that the total area of ​​core portion 25 is one-tenth or less of the area of ​​core portion 23.

[0057] When viewed along the axial direction, the thickness of core portion 25, specifically the thickness between the radially outer edge (outer peripheral surface) of core portion 25 and the radially inner edge (inner surface of hole 28A) of core portion 25, is set to 1 mm or more. This makes it possible to manufacture rotor core 21 including core portion 25 with sufficient strength by integral compression molding for powder magnetic cores in which it is difficult to mold a narrow core portion less than 1 mm with sufficient strength.

[0058] As shown in Figs. 1 and 3, hole 29 includes holes 29A and 29B, and penetrates and opens onto the outer peripheral surface of rotor core 21 on the radially outer side in axial range 301.

[0059] When viewed along the axial direction, hole portion 29A is adjacent to hole portion 27, and hole portion 29B is adjacent to hole portion 29B and penetrates the radially outer outer peripheral surface of rotor core 21.

[0060] 2 and 3, in axial range 302, hole 29 does not penetrate the outer peripheral surface on the radial outside of rotor core 21, and only hole 29A of holes 29A and 29B is provided. In other words, hole 29A penetrates the entire axial range of rotor core 21, while hole 29B is provided only in range 301 that corresponds to a part of the entire axial range of rotor core 21 with respect to the other axial end.

[0061] 2 and 3, in the axial range 302, iron core portion 26 corresponding to the bridge portion between iron core portions 23, 24 is provided at a location corresponding to hole portion 29B. This allows iron core portion 26 to connect iron core portions 23, 24 on the radial outside of hole portion 29A. Therefore, in the axial range 301, a state in which hole portion 29 penetrates the outer peripheral surface on the radial outside can be realized, while satisfying the strength requirements of rotor core 21 and ensuring appropriate strength of rotor core 21.

[0062] When viewed along the axial direction, it is desirable that the area of ​​core portion 26 is sufficiently small compared to the areas of core portions 23, 24. This is because, as described below, core portion 26 serves as a path for leakage magnetic flux of permanent magnet 22 that does not contribute to the output of rotating electric machine 1. For example, when viewed along the axial direction, it is desirable that the total area of ​​core portion 26 is one-tenth or less of the area of ​​core portion 23.

[0063] When viewed along the axial direction, the thickness of core portion 26, specifically, the thickness between the radially outer edge (outer peripheral surface) of core portion 26 and the radially inner edge (inner surface of hole 29A) of core portion 26, is set to 1 mm or more. This allows rotor core 21 including core portion 26 to be manufactured as a powder magnetic core by integral compression molding.

[0064] 3, holes 28B, 29B are both open at the axial ends. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out on both axial sides, rotor core 21 including holes 28B, 29B formed only in a portion of the axial direction can be compression molded as a single unit.

[0065] For example, as shown in Fig. 4, in the rotor core 21c of the rotor 50c according to the first comparative example, the core portions 25, 26 corresponding to the bridge portion between the core portions 23, 24 are provided over the entire axial range. The dashed lines in Fig. 4 represent the magnetic flux of the permanent magnet 22. In this case, although the action of the holes 28A, 29A can suppress the short circuit of the magnetic flux of the permanent magnet 22 to some extent, the existence of the core portions 25, 26 causes the magnetic flux of the permanent magnet 22 to be short circuited. As a result, the magnetic flux short circuited through the core portions 25, 26 does not interlink with the winding 12 of the stator 10, and becomes leakage magnetic flux that does not contribute to the output of the rotating electric machine 1.

[0066] In contrast, in this example, one of the holes 28, 29 is provided to penetrate the outer peripheral surface on the radial outside over the entire axial range of the rotor core 21. As a result, only one of the core portions 25, 26 is present over the entire axial range of the rotor core 21, making it possible to suppress leakage flux that does not contribute to the output of the rotating electric machine 1 more effectively than in the first comparative example.

[0067] In this example, in a portion of the entire axial range of the rotor core 21 starting from one end, only the holes 28 penetrate the outer peripheral surface on the radial outside, and in the remaining portion of the axial range starting from the other end, only the holes 29 penetrate the outer peripheral surface on the radial outside. This allows the action of the core parts 25 and 26 adjacent to the holes 28B and 29B in the axial direction to counter the centrifugal force acting on the core part 24 in a direction that widens the circumferential width of the holes 28B and 29B when the rotor 20 rotates. Therefore, it is possible to realize a rotor core 21 having a higher strength than a case in which only one of the holes 28 and 29 penetrates the outer peripheral surface on the radial outside over the entire axial range of the rotor core 21.

[0068] <Second example of a rotating electrical machine> Fig. 5 is a cross-sectional view showing a third example of a cross section of the rotating electric machine 1 according to the first embodiment. Fig. 6 is a diagram showing a second example of the rotor 20 of the rotating electric machine 1 according to the first embodiment. Specifically, Fig. 3 is a diagram showing the rotating electric machine 1 as viewed from an arrow α in Figs. 1, 2, and 5.

[0069] Hereinafter, in this example, the same reference numerals are used for configurations that are the same as or correspond to those in the first example described above, and the description will be centered on the parts that are different from the first example described above, and the description of the same or corresponding contents as those in the first example described above may be omitted. Also, the third and subsequent examples of the rotating electric machine 1 according to the first embodiment described below will be described in a similar manner in relation to the examples of the rotating electric machine 1 according to the first embodiment already described.

[0070] As shown in FIG. 5, in this example, rotor core 21 differs from the above-described first example in that both holes 28, 29 penetrate the outer peripheral surface on the radial outside in a portion of the entire axial range.

[0071] Specifically, as shown in Fig. 6, rotor core 21 has the cross-sectional shape of Fig. 1 in range 601 including one axial end of the entire axial range, and has the cross-sectional shape of Fig. 2 in range 602 including the other axial end. Rotor core 21 has the cross-sectional shape of Fig. 5 in the remaining range 603 between axial ranges 601 and 602.

[0072] 6, holes 28B, 29B are both open at both ends in the axial direction. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out on both sides in the axial direction, rotor core 21 including holes 28B, 29B formed only in a portion of the axial direction can be compression molded as a single unit.

[0073] In this way, in this example, the core portions 25 and 26 are omitted in the range 603 among the entire range in the axial direction. Therefore, leakage flux that does not contribute to the output of the rotating electric machine 1 can be further suppressed. Also, in the axial range 603, the core portions 23 and 24 are completely separated, but in the adjacent axial ranges 601 and 602, the core portions 23 and 24 are connected by the core portion 25 or the core portion 26. Therefore, the rotor core 21 can be realized by an integrally molded powder magnetic core. Therefore, while the rotor core 21 is realized as an integral powder magnetic core, leakage flux that does not contribute to the output of the rotating electric machine 1 can be further suppressed.

[0074] <Third example of a rotating electrical machine> FIG. 7 is a diagram showing a third example of the rotor 20 of the rotating electric machine 1 according to the first embodiment.

[0075] As shown in FIG. 7, this example differs from the first and second examples described above in that, in a portion of the entire axial range of rotor core 21, holes 28, 29 do not penetrate to the radially outer outer peripheral surface, and core portions 23, 24 are connected by both core portions 25, 26.

[0076] In addition, since the cross-sectional view of the point where holes 28, 29 do not penetrate the outer peripheral surface on the radial outside and core portions 23, 24 are connected by both core portions 25, 26 is the same as the cross-sectional view at any axial position in the first comparative example described above, it is omitted and reference is made to Figure 4.

[0077] Specifically, in this example, rotor core 21 has the cross-sectional shape of FIG. 5 in range 701 of its entire axial range, and has a cross-sectional shape similar to that of the first comparative example of FIG. 4 in the remaining axial range 702.

[0078] In an axial range 701, core portions 23 and 24 are completely separated, but in an adjacent axial range 702, core portions 23 and 24 are connected by both core portions 25 and 26. Therefore, rotor core 21 can be realized by an integrally molded powder magnetic core.

[0079] 7, holes 28B, 29B are both open at the axial end. Therefore, by using a molding die that is pulled out in the axial direction in the manufacturing process of the powder magnetic core, rotor core 21 including holes 28B, 29B formed only in a portion of the axial direction can be compression molded as a single unit.

[0080] 7, the axial range 701 is set to be larger, in other words, the axial range 702 is set to be smaller, within a range in which the strength of the rotor core 21 is appropriately ensured. This makes it possible to further suppress leakage flux that does not contribute to the output of the rotating electric machine 1 while appropriately ensuring the strength of the rotor core 21.

[0081] <Fourth example of a rotating electrical machine> FIG. 8 is a diagram showing a fourth example of the rotor 20 of the rotating electric machine 1 according to the first embodiment.

[0082] As shown in FIG. 8, in this example, rotor core 21 differs from the above-described third example in that holes 28, 29 do not penetrate the outer peripheral surface on the radially outer side, and core portions 23, 24 are connected by both core portions 25, 26 in a partial axial range of the arrangement structure.

[0083] Specifically, in this example, rotor core 21 has the cross-sectional shape of Fig. 5 in range 801 including one axial end and range 802 including the other axial end of the entire range in the axial direction. Rotor core 21 has the same cross-sectional shape as the first comparative example in Fig. 4 in the remaining range 803 between axial ranges 801 and 802.

[0084] 8, holes 28B, 29B are both open at both axial ends. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out on both axial ends, rotor core 21 including holes 28B, 29B formed only in a portion of the axial direction can be compression molded as a single unit.

[0085] 8, axial ranges 801, 802 are set to be larger, in other words, axial range 803 is set to be smaller, within a range in which the strength of rotor core 21 is appropriately ensured. This makes it possible to further suppress leakage flux that does not contribute to the output of rotating electric machine 1 while appropriately ensuring the strength of rotor core 21, as in the above-described third example.

[0086] <5th example of a rotating electrical machine> FIG. 9 is a diagram showing a fifth example of the rotor 20 of the rotating electric machine 1 according to the first embodiment.

[0087] As shown in FIG. 9, in this example, rotor core 21 differs from the third and fourth examples described above in that holes 28, 29 do not penetrate the radially outer outer peripheral surface, and core portions 23, 24 are connected by both core portions 25, 26 in a partial axial arrangement structure.

[0088] Specifically, in this example, rotor core 21 has a cross-sectional shape similar to that of the first comparative example in Fig. 4 in range 901 including one axial end and range 902 including the other axial end of the entire axial range. Rotor core 21 has the cross-sectional shape of Fig. 5 in the remaining range 903 between axial ranges 901 and 902.

[0089] 9, holes 28B, 29B are not open to either end in the axial direction. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that draws out in the radial direction in addition to a molding die that draws out in both axial directions, it is possible to compression mold rotor core 21 as a whole, including holes 28B, 29B formed only in part of the axial direction.

[0090] 9, the axial range 903 is set to be larger, in other words, the axial ranges 901, 902 are set to be smaller, within a range in which the strength of the rotor core 21 is appropriately ensured. This makes it possible to further suppress leakage flux that does not contribute to the output of the rotating electric machine 1 while appropriately ensuring the strength of the rotor core 21, as in the third and fourth examples described above.

[0091] <Sixth example of a rotating electrical machine> FIG. 10 is a cross-sectional view showing a fourth example of a cross section of the rotating electric machine 1 according to the first embodiment.

[0092] As shown in FIG. 10, in this example, rotor core 21 does not have holes 27-29 in a portion of its entire axial range, and permanent magnets 22 are provided only in a portion of its entire axial range excluding the axial range in which holes 27-29 are not provided, which is different from the first to fifth examples described above.

[0093] Specifically, in the axial range where holes 27-29 are not provided, rotor core 21 has a solid cylindrical shape except for a through hole portion centered on rotation axis AX into which rotation shaft 30 is inserted.

[0094] For example, in the axial range 702 of the rotor core 21 in the above-mentioned third example (FIG. 7), the cross-sectional shape in FIG. 10 is adopted instead of the cross-sectional shape in FIG. 5. In this case, the axial range 701 is set to be larger than that in the above-mentioned third example, in other words, the axial range 702 is set to be smaller than that in the above-mentioned third example, within a range in which the strength of the rotor core 21 is appropriately ensured. This is because the portion of the cross-sectional shape in FIG. 10 out of the entire axial range of the rotor core 21 does not contribute to the output of the rotating electric machine 1. Also, in the axial range 803 of the rotor core 21 in the above-mentioned fourth example (FIG. 8), the cross-sectional shape in FIG. 10 may be adopted instead of the cross-sectional shape in FIG. 5. In this case, similarly, the axial ranges 801, 802 are set to be larger than that in the above-mentioned fourth example, in other words, the axial range 803 is set to be smaller than that in the above-mentioned fourth example, within a range in which the strength of the rotor core 21 is appropriately ensured. For example, the axial length of axial range 702 and range 803 is about 1 mm, which is desirably sufficiently smaller than the width of the short side of permanent magnet 22 in hole 27 in which permanent magnet 22 is embedded when viewed along the axial direction.

[0095] <Seventh example of a rotating electrical machine> FIG. 11 is a cross-sectional view showing a fifth example of a cross section of the rotating electric machine 1 according to the first embodiment.

[0096] As shown in FIG. 11, in this example, assuming the cross-sectional shape of the second example (FIG. 2) of the cross section of the rotating electric machine 1 according to the first embodiment, when the rotor core 21 is viewed along the axial direction, the corners and edges of the holes 28 and 29 are rounded in a curved shape. For example, as shown in FIG. 11, the corners of the hole 28 refer to the corners between the inner surface and the outer peripheral surface of the hole 28B when the hole 28 penetrates the outer peripheral surface of the rotor core 21 in the radial direction. Also, for example, the corners of the hole 29 refer to the corners of the inner surface on the tip side of the hole 29A, the side adjacent to the hole 27 being the base end, when the hole 29 does not penetrate the outer peripheral surface of the rotor core 21 in the radial direction. Both the corners of the hole 28 and the corners of the hole 29 may be rounded in a curved shape, or only one of them may be rounded in a curved shape. It is desirable that the radius of curvature of the corners of hole 28 and hole 29 that are rounded into a curved shape is sufficiently smaller than the width of the short side of permanent magnet 22 in hole 27 in which permanent magnet 22 is embedded when viewed along the axial direction. This is to prevent the area of ​​the magnetic pole of permanent magnet 22 facing the stator from being narrower than necessary.

[0097] Similarly, in this example, assuming the cross-sectional shape of the first example (FIG. 1) of the transverse section of the rotating electric machine 1 according to the first embodiment, when the rotor core 21 is viewed along the axial direction, the corners and edges of the holes 28 and 29 may be rounded in a curved shape. For example, the corners of the hole 28 refer to the corners of the inner surface of the tip end side of the hole 28A, the side adjacent to the hole 27 being the base end, when the hole 28 does not penetrate the outer peripheral surface of the rotor core 21 in the radial direction. Also, the corners of the hole 29 refer to the corners between the inner surface and the outer peripheral surface of the hole 29B, when the hole 29 penetrates the outer peripheral surface of the rotor core 21 in the radial direction. Both the corners of the hole 28 and the corners of the hole 29 may be rounded in a curved shape, or only one of them may be rounded in a curved shape. The radius of curvature of the rounded corners of hole 28 and hole 29 may be the same as that of the corners of hole 28 and hole 29 described above.

[0098] As a result, in this example, based on the first example of the rotating electric machine 1 according to the first embodiment described above, it is possible to reduce torque ripple and suppress cracks and chipping after compression molding of the rotor core 21 as a powder magnetic core.

[0099] In addition, in this example, assuming the cross-sectional shape of the third example (Figure 5) of the cross section of the rotating electric machine 1 according to the first embodiment, when the rotor core 21 is viewed along the axial direction, the corners of the holes 28, 29 may be rounded into a curved shape.

[0100] As a result, in this example, assuming the second or third example of the rotating electric machine 1 according to the first embodiment described above, it is possible to reduce torque ripple and suppress cracking or chipping after compression molding of the rotor core 21 as a powder magnetic core.

[0101] In addition, in this example, assuming that the cross-sectional shape of the rotor core 21 is similar to that of the rotor 20 (Figure 4) of the first comparative example, when the rotor core 21 is viewed along the axial direction, the corners of the holes 28, 29 may be rounded into a curved shape.

[0102] As a result, in this example, assuming the fourth or fifth example of the rotating electric machine 1 according to the first embodiment described above, it is possible to reduce torque ripple and suppress cracks and chipping after compression molding of the rotor core 21 as a powder magnetic core.

[0103] <8th example of a rotating electrical machine> FIG. 12 is a vertical cross-sectional view showing an eighth example of the rotor 20 of the rotating electric machine 1 according to the first embodiment.

[0104] The vertical cross section of the rotating electric machine 1 refers to a cross section of the rotating electric machine 1 taken along a plane that is parallel to and includes the rotation axis AX.

[0105] As shown in FIG. 12, this example differs from the above-mentioned first to seventh examples in that an end plate 40 is provided on the rotor 20 of the rotating electric machine 1, but in other respects may be the same as any one of the above-mentioned first to seventh examples.

[0106] Specifically, in this example, the rotating electric machine 1 includes a stator 10, a rotor 20, a rotating shaft 30, and an end plate 40.

[0107] The end plates 40 are attached to both axial end faces of the rotor core 21 of the rotor 20. The end plates 40 are, for example, made of a non-magnetic material. Specifically, the end plates 40 have an annular flat plate shape based on the rotation axis AX, and are provided so as to cover the axial end faces of the rotor core 21. This makes it possible to prevent the permanent magnets 22 from falling out of the holes 27 (magnet slots).

[0108] Furthermore, when assuming the sixth example of the rotating electric machine 1 described above, the end plate 40 may be provided only on one of both axial end faces of the rotor core 21 through which the hole portion 27 penetrates and the permanent magnet 22 is exposed.

[0109] 12, in this example, a protrusion 41 that protrudes axially toward the rotor core 21 is provided on the radially outer outer edge (periphery) of the end plate 40. The protrusion 41 is formed, for example, by bending the outer periphery of the end plate 40. Alternatively, the protrusion 41 may be prepared as a separate member from the main body of the end plate 40 and formed by connecting the two by welding or the like.

[0110] The protrusion 41 is adapted to fit into an annular groove provided near the outer edge of the radially outer side of the axial end face of the rotor core 21. This allows the protrusion 41 of the end plate 40 to apply a force to the core portion 24 against the centrifugal force when the rotor 20 rotates. Therefore, even if the holes 28, 29 penetrate the outer peripheral surface of the radially outer side of the rotor core 21 in a part of the axial direction of the rotor core 21 and the core portion 24 is easily deformed radially outward, the deformation of the core portion 24 when the rotor 20 rotates can be suppressed. Therefore, the strength of the rotor core 21 can be more appropriately ensured while suppressing leakage flux that does not contribute to the output of the rotating electric machine 1.

[0111] <Other examples of rotating electrical machines> The rotating electric machine 1 according to the first embodiment described above (first to eighth examples) may be modified or changed as appropriate.

[0112] For example, in the eighth example of the rotating electric machine 1 described above, instead of being configured to fit into a groove on the axial end face of the rotor core 21, the protrusion 41 may be configured to fit into the outer peripheral surface of the rotor core 21 from the radial outside.

[0113] Furthermore, in the eighth example of the rotating electric machine 1 described above, even if the first to fifth examples of the rotating electric machine 1 described above are used as a premise, the end plate 40 may be provided on only one of the two end faces of the rotor core 21.

[0114] In addition, in the first to seventh examples of the rotating electric machine 1 described above, an end plate 40 that does not have a protrusion 41 as in the eighth example described above may be provided on at least one of both axial end faces of the rotor core 21.

[0115] Furthermore, in the first to eighth examples of the rotating electric machine 1 described above and their modified and altered examples, the number of teeth 14, i.e., the number of winding slots formed between two adjacent teeth 14, may be 23 or less, or 25 or more.

[0116] In the above-described first to eighth examples of the rotating electric machine 1 and their modified and altered examples, the number of permanent magnets 22 arranged in the circumferential direction may be three or less, or may be five or more. Since the number of poles is usually an even number, the number of permanent magnets 22 is often an even number. Therefore, for example, the number of permanent magnets 22 is two, or an even number of six or more.

[0117] In the first to eighth examples of the rotating electric machine 1 and the examples of their modifications and changes, the permanent magnet 22 may have a shape other than an elongated rectangular shape when viewed along the axial direction. For example, the permanent magnet 22 may have a V-shaped or U-shaped shape that is convex inward in the radial direction when viewed along the axial direction. When the permanent magnet 22 has a V-shaped shape when viewed along the axial direction, the V-shaped shape may be realized by combining two magnet members having elongated rectangular shapes. In this case, the two magnet members are arranged magnetically in parallel. When the permanent magnet 22 has a U-shaped shape when viewed along the axial direction, a U-shaped shape configured in a curved shape (i.e., a circular arc shape) may be realized by one magnet member. The U-shaped shape may be realized by combining a plurality of (for example, three) magnet members having elongated rectangular shapes. In this case, the three magnet members are arranged magnetically in parallel. The permanent magnets 22 may be arranged in a radial direction such that a plurality of magnet members are arranged magnetically in series. Furthermore, the permanent magnets 22 may be arranged in a form in which a plurality of them are magnetically arranged in parallel in the axial direction.

[0118] Furthermore, in the first to eighth examples of the rotating electric machine 1 described above and their modified and altered examples, holes 28A, 28B and holes 29A, 29B may be arranged (e.g., filled) with a material (e.g., resin) having a lower magnetic permeability than rotor core 21.

[0119] [Second embodiment] Next, a rotating electric machine 1 according to a second embodiment will be described with reference to FIGS.

[0120] In the second embodiment, the same reference numerals are used to denote the same or corresponding configurations as in the first embodiment, and the description will focus on the parts that differ from the first embodiment, and the description of the same or corresponding contents as in the first embodiment may be omitted. Also, the third embodiment described later will be described in a similar manner, assuming the first and second embodiments already described.

[0121] <First example of a rotating electrical machine> Fig. 13 is a cross-sectional view showing a first example of a cross section of the rotating electric machine 1 according to the second embodiment. Fig. 14 is a cross-sectional view showing a second example of a cross section of the rotating electric machine 1 according to the second embodiment. Fig. 15 is a vertical cross-sectional view showing a first example of a rotor 50 according to the second embodiment. Specifically, Fig. 15 is a cross-sectional view taken along line BB in Figs. 13 and 14. Fig. 16 is a diagram showing a rotor 50c according to a second comparative example.

[0122] In this example, the rotating electric machine 1 may include the stator 10 similar to that of the first embodiment. Therefore, the stator 10 is omitted from illustration in Fig. 13 and Fig. 14. In Fig. 13 and Fig. 14, the magnetization direction of the permanent magnet 52 is depicted by an arrow.

[0123] As shown in FIGS. 13 to 15, in this example, a rotating electric machine 1 includes a stator 10, a rotating shaft 30, and a rotor 50. In the embodiment, as shown in FIG.

[0124] The rotor 50 is disposed facing the inside of the stator 10 in the radial direction. The rotor 50 is fixed to the rotating shaft 30 and is rotatable about the rotating axis AX. The rotor 50 includes a rotor core 51 and a plurality of permanent magnets 52.

[0125] Among the components of the rotor 50, the rotor core 51 is a component that functions as a magnetic path for the magnetic flux due to the armature current flowing through the windings 12 of the stator 10, and as a magnetic path for the magnetic field of the permanent magnets 52. The rotor core 51 is a powder magnetic core that is compression molded as a single unit. The rotor core 51 has a substantially cylindrical shape centered on the rotation axis AX, and is provided with a through hole that penetrates in the axial direction centered on the rotation axis AX. The rotating shaft 30 is inserted into the through hole, and the rotor core 51 is fixed to the rotating shaft 30.

[0126] A plurality of permanent magnets 52 (four in this example) are embedded in the rotor core 51. The permanent magnets 52 are, for example, ferrite magnets or neodymium magnets. The plurality of permanent magnets 52 are arranged at equal intervals in the circumferential direction. The permanent magnets 52 may be sintered magnets or bonded magnets. In the latter case, for example, the permanent magnets 52 may be molded integrally with the rotor core 51 by injection molding or the like.

[0127] The number of permanent magnets 52 arranged in the circumferential direction may be three or less, or may be five or more.

[0128] 13 and 14, each of the permanent magnets 52 has a substantially rectangular shape with one side sufficiently longer than the other sides when viewed along the axial direction, and is arranged so that the long side substantially coincides with the radial axis. Each of the permanent magnets 52 is magnetized so that both ends in the short side direction have magnetic poles (N pole and S pole) with different polarities. This allows each of the permanent magnets 52 to be arranged so that both end faces in the circumferential direction have different magnetic poles.

[0129] The multiple permanent magnets 52 are arranged so that the magnetic poles of both end faces in the circumferential direction are the same as the magnetic poles facing in the circumferential direction of adjacent permanent magnets 52 in the circumferential direction. For example, the surface of one permanent magnet 52 that faces the one permanent magnet 52 of another permanent magnet 52 adjacent to the S pole side of the one permanent magnet 52 in the circumferential direction is magnetized with an S pole. On the other hand, the surface of the other permanent magnet 52 that faces the one permanent magnet 52 of the other permanent magnet 52 adjacent to the N pole side of the one permanent magnet 52 in the circumferential direction is magnetized with an N pole.

[0130] 13 and 14, rotor core 51 includes core portions 53 to 55. Rotor core 51 is also provided with holes 56 to 58.

[0131] As shown in FIG. 15, in this example, rotor core 51 has the cross-sectional shape of FIG. 13 in range 1501 of the entire axial range, and has the cross-sectional shape of FIG. 14 in the remaining axial range 1502.

[0132] The holes 56 correspond to slots (magnet slots) in which the permanent magnets 52 are embedded. The holes 56 are provided so as to penetrate the rotor core 51 in the axial direction. This allows the permanent magnets 52 to be arranged over the entire range of the rotor core 51 in the axial direction.

[0133] Hole 57 is provided adjacent to the radially inner side of hole 56 and penetrates the radially inner inner circumferential surface of rotor core 51. Hole 58 is provided adjacent to the radially outer side of hole 56 and penetrates the radially outer outer circumferential surface of rotor core 51. Holes 57 and 58 correspond to flux barriers for suppressing short-circuiting of magnetic flux at the end of permanent magnet 52 in a direction perpendicular to the main magnetic flux.

[0134] The core portions 53 are portions of the rotor core 51 that are partitioned in the circumferential direction by the holes 56. In this example, the rotor core 51 is partitioned into four core portions 53 by the four holes 56 (magnet slots).

[0135] As shown in FIGS. 14 and 15, holes 57 are provided only in a range 1502 of the entire range of rotor core 51 in the axial direction.

[0136] 13 and 15, in the remaining range 1501 of the entire axial range of rotor core 51, core portions 54 corresponding to bridge portions between circumferentially adjacent core portions 53 are provided in locations corresponding to holes 57. This allows core portions 54 to connect circumferentially adjacent core portions 53 on the radially inner side of holes 57 (magnet slots). Therefore, in axial range 1502, a state in which holes 57 penetrate the radially inner inner circumferential surface of rotor core 51 can be achieved, while ensuring appropriate strength of rotor core 51.

[0137] When viewed along the axial direction, it is desirable that the area of ​​core portion 54 is sufficiently smaller than the area of ​​core portion 53. This is because, as described below, core portion 54 serves as a path for leakage magnetic flux of permanent magnet 52 that does not contribute to the output of rotating electric machine 1. For example, when viewed along the axial direction, it is desirable that the area of ​​core portion 54 is one-tenth or less of the area of ​​core portion 53.

[0138] When viewed along the axial direction, the thickness of core portion 54, specifically, the thickness between the radially inner outer edge (inner circumferential surface) of core portion 54 and the radially outer outer edge (radially inner surface of hole 56) of core portion 54, is set to 1 mm or more. This allows rotor core 51 including core portion 54 to be manufactured by integral compression molding as a powder core with sufficient strength, similar to the rotor core 21 of the above-mentioned first embodiment.

[0139] As shown in FIGS. 13 and 15, holes 58 are provided only in a range 1501 of the entire range of rotor core 51 in the axial direction.

[0140] 14 and 15, in the remaining range 1502 out of the entire axial range of the rotor core 51, iron core portions 55 corresponding to bridge portions between circumferentially adjacent iron core portions 53 are provided in the locations corresponding to the holes 58. This allows the iron core portions 55 to connect the circumferentially adjacent iron core portions 53 on the radially inner side of the holes 57 (magnet slots). Therefore, in the axial range 1501, a state in which the holes 58 penetrate the radially outer outer peripheral surface of the rotor core 51 can be achieved, while ensuring appropriate strength of the rotor core 51.

[0141] When viewed along the axial direction, it is desirable that the area of ​​core portion 55 is sufficiently smaller than the area of ​​core portion 53. This is because, as described below, core portion 55 serves as a path for leakage magnetic flux of permanent magnet 52 that does not contribute to the output of rotating electric machine 1. For example, when viewed along the axial direction, it is desirable that the area of ​​core portion 55 is one-tenth or less of the area of ​​core portion 53.

[0142] When viewed in the axial direction, the thickness of core portion 55, specifically, the thickness between the radially outer edge (outer peripheral surface) of core portion 55 and the radially inner edge (radial outer surface of hole portion 56) of core portion 55, is set to 1 mm or more. This allows rotor core 51 including core portion 55 to be manufactured as a powder magnetic core by integral compression molding.

[0143] 15, both holes 57, 58 have open axial ends. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out on both axial sides, rotor core 51 including holes 57, 58 formed only in a portion of the axial direction can be compression molded as a single unit.

[0144] For example, as shown in Fig. 16, in a rotor core 51c of a rotor 50c according to a second comparative example, core portions 54, 55 corresponding to bridge portions between adjacent core portions 53 in the circumferential direction are provided over the entire axial range. The dashed lines in Fig. 16 represent the magnetic flux of the permanent magnet 52. In this case, the presence of the core portions 54, 55 causes a short circuit of the magnetic flux of the permanent magnet 52. As a result, the magnetic flux short-circuited through the core portions 54, 55 does not interlink with the windings 12 of the stator 10, and becomes leakage magnetic flux that does not contribute to the output of the rotating electric machine 1.

[0145] In contrast, in this example, either a state in which hole 57 penetrates the radially inner inner circumferential surface or a state in which hole 58 penetrates the radially outer outer circumferential surface is realized over the entire axial range of rotor core 51. As a result, only one of core portions 54 and 55 is present over the entire axial range of rotor core 51, and leakage magnetic flux that does not contribute to the output of rotating electric machine 1 can be suppressed more than in the second comparative example.

[0146] Furthermore, in this example, only the holes 57 are provided in a portion of the entire axial range of the rotor core 51 starting from one end, and only the holes 58 are provided in the remaining range starting from the other end. This allows the action of the core parts 54 and 55 adjacent to the holes 57 and 58 in the axial direction to counter the centrifugal force acting on the core part 53 to deform the areas near the holes 57 and 58 when the rotor 50 rotates. This allows the rotor core 51 to have a higher strength than when only one of the holes 57 and 58 is provided over the entire axial range of the rotor core 51.

[0147] <Second example of a rotating electrical machine> Fig. 17 is a cross-sectional view showing a third example of a horizontal cross section of the rotating electric machine 1 according to the second embodiment. Fig. 18 is a vertical cross-sectional view showing a second example of the rotor 50 of the rotating electric machine 1 according to the second embodiment.

[0148] In FIG. 17, the magnetization direction of the permanent magnet 52 is depicted by an arrow.

[0149] Hereinafter, in this example, the same reference numerals are used for configurations that are the same as or correspond to those in the first example described above, and the description will be centered on the parts that are different from the first example described above, and the description of the same or corresponding contents as those in the first example may be omitted. Also, the third and subsequent examples of the rotating electric machine 1 according to the second embodiment described later will be described in a similar manner in relation to the examples of the rotating electric machine 1 according to the second embodiment already described.

[0150] As shown in FIG. 17, in this example, rotor core 51 is different from the above-described first example in that both holes 57, 58 are provided in a portion of the entire axial range.

[0151] Specifically, as shown in Fig. 18, rotor core 51 has the cross-sectional shape of Fig. 13 in range 1801 including one axial end of the entire axial range, and has the cross-sectional shape of Fig. 14 in range 1802 including the other axial end. Rotor core 51 has the cross-sectional shape of Fig. 17 in the remaining range 1803 between axial ranges 1801 and 1802.

[0152] 18, holes 57, 58 are both open at both ends in the axial direction. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out on both sides in the axial direction, rotor core 51 including holes 57, 58 formed only in a portion of the axial direction can be compression molded as a single unit.

[0153] In this way, in this example, the core parts 54 and 55 are omitted in the range 1803 of the entire range in the axial direction. Therefore, leakage flux that does not contribute to the output of the rotating electric machine 1 can be further suppressed. Furthermore, in the axial range 1803, the core parts 53 adjacent in the circumferential direction are completely separated from each other, but in the adjacent axial ranges 1801 and 1802, the core parts 23 adjacent in the circumferential direction are connected to each other by the core parts 54 or the core parts 55. Therefore, the rotor core 51 can be realized by an integrally molded powder magnetic core. Therefore, while the rotor core 51 is realized as an integral powder magnetic core, leakage flux that does not contribute to the output of the rotating electric machine 1 can be further suppressed.

[0154] <Third example of a rotating electrical machine> FIG. 19 is a vertical cross-sectional view showing a third example of the rotor 50 of the rotating electric machine 1 according to the second embodiment.

[0155] As shown in FIG. 19, this example differs from the first and second examples described above in that, in a portion of the entire axial range of rotor core 51, neither hole portion 57, 58 is provided, and adjacent core portions 53 in the circumferential direction are connected by both core portions 54, 55.

[0156] In addition, since the cross-sectional view of the portion where holes 57, 58 are not provided and adjacent core portions 53 in the circumferential direction are connected by both core portions 54, 55 is the same as the cross-sectional view at any axial position in the second comparative example described above, FIG. 15 is used and an illustration is omitted.

[0157] Specifically, in this example, rotor core 51 has the cross-sectional shape of FIG. 17 in range 1901 of its entire axial range, and has a cross-sectional shape similar to that of the second comparative example of FIG. 15 in the remaining axial range 1902.

[0158] In an axial range 1901, circumferentially adjacent core portions 53 are completely separated from each other, but in an adjacent axial range 1902, circumferentially adjacent core portions 53 are connected to each other by both core portions 54, 55. Therefore, rotor core 51 can be realized by an integrally molded powder magnetic core.

[0159] 19, holes 57, 58 are both open at the axial end. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out in the axial direction, rotor core 51 including holes 57, 58 formed only in a portion of the axial direction can be compression molded as a single unit.

[0160] 19, the axial range 1901 is set to be larger, in other words, the axial range 1902 is set to be smaller, within a range in which the strength of the rotor core 51 is appropriately ensured. This makes it possible to further suppress leakage flux that does not contribute to the output of the rotating electric machine 1 while appropriately ensuring the strength of the rotor core 51.

[0161] <Fourth example of a rotating electrical machine> FIG. 20 is a vertical cross-sectional view showing a fourth example of the rotor 50 of the rotating electric machine 1 according to the second embodiment.

[0162] As shown in FIG. 20, in this example, rotor core 51 differs from the above-described third example in that neither hole portion 57, 58 is provided, and the arrangement structure in a portion of the axial direction is such that adjacent core portions 53 in the circumferential direction are connected by both core portions 54, 55.

[0163] Specifically, in this example, rotor core 51 has the cross-sectional shape shown in Fig. 17 in range 2001 including one axial end of the entire axial range, and range 2002 including the other axial end. Rotor core 51 has the same cross-sectional shape as the second comparative example in Fig. 15 in the remaining range 2003 between axial ranges 2001 and 2002.

[0164] 20, holes 57, 58 are both open at both axial ends. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out on both axial ends, rotor core 51 including holes 57, 58 formed only in a portion of the axial direction can be compression molded as a single unit.

[0165] 20, the axial ranges 2001 and 2002 are set to be larger, in other words, the axial range 2003 is set to be smaller, within a range in which the strength of the rotor core 51 is appropriately ensured. This makes it possible to further suppress leakage flux that does not contribute to the output of the rotating electric machine 1 while appropriately ensuring the strength of the rotor core 51, as in the above-described third example.

[0166] <5th example of a rotating electrical machine> 21 is a diagram showing a fifth example of the rotor 50 of the rotating electric machine 1 according to the second embodiment. Specifically, FIG. 21 is a diagram showing the rotating electric machine 1 as viewed from an arrow β in FIG.

[0167] As shown in FIG. 21, this example differs from the above-described fourth example in that the circumferential width of hole 58 changes in the axial direction, but may be the same as the above-described fourth example in other respects.

[0168] Specifically, in this example, in the ranges 2001, 2002, the circumferential width of the hole 58 is formed so as to increase toward the axial end. For example, as shown in Fig. 21, the circumferential width of the hole 58 is formed so as to increase in stages (in two stages in this example) toward the axial end. Alternatively, the circumferential width of the hole 58 may be formed so as to increase continuously toward the axial end. This can further suppress leakage flux that does not contribute to the output of the rotating electric machine 1.

[0169] Furthermore, since the circumferential width of the hole 58 is formed so as to increase toward the axial end, the manufacturing process for the powder magnetic core can employ a molding die that draws out on both sides in the axial direction, and the rotor core 51 can be compression molded as a single unit.

[0170] <Other examples of rotating electrical machines> The rotating electric machine 1 according to the second embodiment described above (first to fifth examples) may be modified or changed as appropriate.

[0171] For example, in the fifth example of the rotating electric machine 1 described above, instead of or in addition to the hole 58, the hole 57 may be formed so that its circumferential width increases toward the end in the axial direction.

[0172] In addition, in the above-mentioned fifth example of the rotating electric machine 1 and its modified or modified examples, the circumferential width of only a portion of the plurality of holes 58 and the plurality of holes 57 provided in the rotor core 51 may be formed so as to increase toward the axial end.

[0173] In addition, in the first to fifth examples of the rotating electric machine 1 described above and their modified and altered examples, an end plate similar to the end plate 40 of the first embodiment may be provided on at least one of both axial end faces of the rotor core 51.

[0174] Furthermore, in the first to fifth examples of the rotating electric machine 1 described above and their modified and altered examples, the corners of the holes 57, 58 may be rounded into a curved shape by applying the same concept as in the seventh example of the rotating electric machine 1 of the first embodiment.

[0175] Furthermore, in the third and fourth examples of the rotating electric machine 1 described above and examples of their modifications and variations, the same idea as in the sixth example of the rotating electric machine 1 of the first embodiment may be applied. Specifically, in the rotor core 51, the holes 56-58 may not be provided in a part of the entire axial range, and the permanent magnets 52 may be provided only in a part of the entire axial range excluding the axial range in which the holes 56-58 are not provided.

[0176] In addition, in the first to fifth examples of the rotating electric machine 1 described above and examples of variations and modifications thereof, holes 57 and holes 58 may be arranged (e.g., filled) with a material (e.g., resin) having a lower magnetic permeability than rotor core 51.

[0177] In addition, in the first to fifth examples of the rotating electric machine 1 described above and the variations and modifications thereof, some or all of the holes 57 may be omitted.

[0178] [Third embodiment] Next, a rotating electric machine 1 according to a third embodiment will be described with reference to FIGS.

[0179] <First example of a rotating electrical machine> FIG. 22 is a cross-sectional view showing a first example of a cross section of the rotating electric machine 1 according to the third embodiment. FIG. 23 is a cross-sectional view showing a second example of a cross section of the rotating electric machine 1 according to the third embodiment. FIG. 24 is a vertical cross-sectional view showing a first example of the rotor 60 of the rotating electric machine 1 according to the third embodiment. Specifically, FIG. 24 is a cross-sectional view taken along the line CC in FIG. 23 and FIG. 24. FIG. 25 is a diagram showing a rotor 60c1 according to a third comparative example. Specifically, FIG. 25 includes FIG. 25A showing a flow of magnetic flux when the magnetic pole position of the stator 10 and the magnetic pole position of the rotor 60c1 coincide with each other, and FIG. 25B showing a flow of magnetic flux when the magnetic pole position of the stator 10 and the magnetic pole position of the rotor 60c1 are shifted by 90 degrees in electrical angle. FIG. 26 is a diagram showing a rotor 60c2 according to a fourth comparative example. Specifically, Figure 26 includes Figure 26A which shows the flow of magnetic flux when the magnetic pole position of stator 10 and the magnetic pole position of rotor 60c2 are aligned, and Figure 26B which shows the flow of magnetic flux when the magnetic pole position of stator 10 and the magnetic pole position of rotor 60c2 are misaligned by 90 electrical degrees.

[0180] In this example, the rotating electric machine 1 may include the stator 10 similar to that of the first embodiment. Therefore, the stator 10 is omitted from Fig. 22 and Fig. 23. In Fig. 22 and Fig. 23, hollow inverted triangles are marked at the magnetic pole positions in the circumferential direction of the rotor 60, and filled in inverted triangles are marked at positions shifted by 90 electrical degrees from the magnetic pole positions.

[0181] 22 to 24, in this example, the rotating electric machine 1 is a synchronous reluctance motor (SynRM). In this example, the rotating electric machine 1 includes a stator 10, a rotating shaft 30, and a rotor 60.

[0182] The rotor 60 is disposed radially inwardly of the stator 10 so as to face the stator 10. The rotor 60 is fixed to the rotating shaft 30 and is rotatable about the rotating axis AX. The rotor 60 includes a rotor core 61.

[0183] Among the components of the rotor 60, the rotor core 61 is a component that functions as a magnetic path for magnetic flux due to the armature current flowing through the windings 12 of the stator 10. The rotor core 61 is a powder magnetic core that is compression molded as a single unit. The rotor core 61 has a substantially cylindrical shape centered on the rotation axis AX, and is provided with a through hole that penetrates in the axial direction centered on the rotation axis AX. The rotating shaft 30 is inserted into the through hole, and the rotor core 61 is fixed to the rotating shaft 30.

[0184] Rotor core 61 includes core portions 62-66. Rotor core 61 is also provided with holes 67-69.

[0185] As shown in FIG. 24, in this example, rotor core 61 has the cross-sectional shape of FIG. 22 in a range 2401 out of the entire range in the axial direction, and has the cross-sectional shape of FIG. 23 in the remaining range 2402 in the axial direction.

[0186] The holes 67-69 are slits corresponding to flux barriers formed between adjacent magnetic pole positions of the rotor core 61 in the circumferential direction. A plurality of combinations of the holes 67-69 (four in this example) are arranged at equal intervals in the circumferential direction in accordance with the number of magnetic poles arranged in the circumferential direction. When viewed along the axial direction, the holes 67-69 each have a circular arc shape that protrudes radially inward, and are arranged in parallel in order from the inside in the radial direction. The holes 67-69 are provided so as to penetrate the rotor core 61 in the axial direction. This allows the holes 67-69 to form slits over the entire axial range of the rotor core 61.

[0187] The hole portion 67 includes hole portions 67A to 67C that correspond to a portion on one side in the circumferential direction, a portion on the other side, and a central portion between the one side and the other side of a middle circumferential position that is shifted by 90 degrees in electrical angle from both of the circumferential positions of the adjacent magnetic poles of the rotor core 61. The hole portion 67C corresponds to a portion that overlaps with a core portion 66A described below when viewed along the axial direction. Similarly, the hole portion 68 includes hole portions 68A to 68C that correspond to a portion on one side in the circumferential direction, a portion on the other side, and a central portion between the one side and the other side of a middle circumferential position that is shifted by 90 degrees in electrical angle from both of the circumferential positions of the adjacent magnetic poles of the rotor core 61. The hole portion 68C corresponds to a portion that overlaps with a core portion 66B described below when viewed along the axial direction. Similarly, the holes 69 include holes 69A to 69C that correspond to a portion on one side, a portion on the other side, and a central portion between the one side and the other side of a midpoint circumferential position that is shifted by 90 electrical degrees from both circumferential positions of adjacent magnetic poles of the rotor core 61. When viewed in the axial direction, the hole 69C corresponds to a portion overlapping with a core portion 66C described below.

[0188] Core portion 62 is a portion of rotor core 61 that is closer to rotation axis AX than hole portion 67C. Core portion 63 is a portion of rotor core 61 between hole portion 67 and hole portion 68. Core portion 64 is a portion of rotor core 61 between hole portion 68 and hole portion 69. Core portion 65 is a portion of rotor core 61 that is radially outward from hole portion 69.

[0189] Core portion 66 corresponds to a bridge portion between core portion 62 and core portions 63-65, and is provided at a midpoint in the circumferential direction that is shifted by 90 electrical degrees from both of the circumferential positions of adjacent magnetic poles of rotor core 51. In this way, core portion 66 can connect core portion 62 and core portions 63-65, which are separated by hole portion 67. Core portion 66 includes core portions 66A-66C.

[0190] Core portion 66A connects core portion 62 and core portion 63 to each other so as to cross hole portion 67. Core portion 66B connects core portion 63 and core portion 64 to each other so as to cross hole portion 68. Core portion 66C connects core portion 64 and core portion 65 to each other so as to cross hole portion 69.

[0191] 23 and 24, the core portion 66 is provided only in a range 2402 of the entire axial range of the rotor core 61. In this way, as shown in Fig. 22, the core portion 66 can ensure an appropriate strength of the rotor core 61 while realizing a state in which the core portions 62-65 are completely separated by the holes 67-69 in the range 2401.

[0192] When viewed along the axial direction, it is desirable that the area of ​​core portion 66 (i.e., core portions 66A-66C) is sufficiently small compared to the area of ​​core portion 62. This is because, as described below, core portion 66 becomes a path for magnetic flux that does not contribute to the output of rotating electric machine 1. For example, when viewed along the axial direction, it is desirable that the total area of ​​core portion 66 provided for each combination of holes 67-69 arranged in the circumferential direction is one-tenth or less of the area of ​​core portion 62.

[0193] When viewed along the axial direction, the thickness of the core portion 66, specifically, the circumferential width of the core portion is set to 1 mm or more. This allows the rotor core 61 including the core portion 66 to be manufactured as a powder magnetic core with sufficient strength by integral compression molding, similar to the rotor core 21 of the first embodiment described above.

[0194] 24, the holes 67-69 are all open at one end in the axial direction. Therefore, by using a molding die that is pulled out on both sides in the axial direction in the manufacturing process of the powder magnetic core, the rotor core 61 including the holes 67-69 formed only in a portion of the axial direction can be compression molded as a single unit.

[0195] For example, as shown in FIG. 25, in the rotor 60c1 according to the third comparative example, the core portion 66 (bridge portion) that connects the core portion 62 and the core portions 63 to 65 is provided over the entire axial range. The dashed lines in FIG. 25 represent the magnetic flux due to the armature current flowing through the winding 12 of the stator 10. In this case, as shown in FIG. 25B, when the magnetic pole position of the stator 10 and the magnetic pole position of the rotor 60c1 are misaligned in the circumferential direction, the core portion 66 functions as a magnetic path for the armature current flowing through the winding 12 of the stator 10, and the inductance increases. As a result, the difference or ratio of inductance between the case where the magnetic pole position of the stator 10 and the magnetic pole position of the rotor 60c1 are aligned in the circumferential direction and the case where they are misaligned becomes small, and the reluctance torque decreases. Therefore, the core portion 66 contributes as a path for magnetic flux that does not contribute to the output of the rotating electric machine including the rotor 60c1 according to the third comparative example.

[0196] Also, for example, as shown in FIG. 26, in the rotor 60c2 according to the fourth comparative example, a core portion 66′ (bridge portion) that connects the core portion 62 and the core portions 63 to 65 near the radially outer outer edge (periphery) of the rotor core 61 is provided over the entire axial range. The dashed lines in FIG. 25 represent the magnetic flux due to the armature current flowing through the winding 12 of the stator 10. In this case, as shown in FIG. 26B, when the magnetic pole position of the stator 10 and the magnetic pole position of the rotor 60c1 are misaligned in the circumferential direction, the core portion 66′ functions as a magnetic path for the magnetic flux due to the armature current flowing through the winding 12 of the stator 10, and the inductance increases. As a result, the difference or ratio of inductance between the case where the magnetic pole position of the stator 10 and the magnetic pole position of the rotor 60c2 are aligned in the circumferential direction and the case where they are misaligned in the circumferential direction becomes small, and the reluctance torque decreases. Therefore, the iron core portion 66' serves as a path for magnetic flux that does not contribute to the output of the rotating electric machine including the rotor 60c2 according to the fourth comparative example.

[0197] In contrast to this, in this example, the core portion 66 (bridge portion) is provided only in a portion of the entire axial range of the rotor core 61, and in other axial portions, the core portions 62-65 are completely separated by the holes 67-69. This makes it possible to suppress the magnetic flux that does not contribute to the output of the rotating electric machine 1 more effectively than in the third and fourth comparative examples.

[0198] 24, the axial range 2401 is set to be larger, in other words, the axial range 2402 is set to be smaller, within a range in which the strength of the rotor core 61 is appropriately ensured. This makes it possible to further suppress the magnetic flux that does not contribute to the output of the rotating electric machine 1 while appropriately ensuring the strength of the rotor core 61.

[0199] <Second example of a rotating electrical machine> Fig. 27 is a vertical cross-sectional view showing a second example of the rotor 60 of the rotating electric machine 1 according to the third embodiment. Specifically, Fig. 27 is a cross-sectional view taken along line CC in Figs.

[0200] As shown in FIG. 27, this example differs from the above-described first example in the arrangement of the cross-sectional shape of FIG. 23 and the cross-sectional shape of FIG. 24 in the axial direction of the rotating electric machine 1.

[0201] Specifically, in this example, rotor core 61 has the cross-sectional shape of Fig. 22 in range 2701 including one axial end of the entire axial range, and range 2702 including the other axial end. Rotor core 61 has the cross-sectional shape of Fig. 23 in the remaining range 2703 between axial ranges 2701 and 2702.

[0202] 27, the holes 67-69 are all open to both ends in the axial direction. Therefore, in the manufacturing process of the powder magnetic core, by using a molding die that is pulled out to both sides in the axial direction, it is possible to compression mold the rotor core 61 as a whole, including the holes 67-69 formed only in a portion of the axial direction.

[0203] 27, the axial ranges 2701 and 2702 are set to be larger, in other words, the axial range 2703 is set to be smaller, within a range in which the strength of the rotor core 61 is appropriately ensured. This makes it possible to further suppress the magnetic flux that does not contribute to the output of the rotating electric machine 1 while appropriately ensuring the strength of the rotor core 61, as in the third example described above.

[0204] <Other examples of rotating electrical machines> The rotating electric machine 1 (first and second examples) according to the third embodiment described above may be modified or changed as appropriate.

[0205] For example, in the first and second examples of the rotating electric machine 1 described above, the number of slits (flux barriers) provided in parallel in the radial direction of the rotor core 61 may be two or less, or may be four or more.

[0206] In the first and second examples of the rotating electric machine 1 described above and their modified and altered examples, an iron core portion 66' may be provided instead of or in addition to the iron core portion 66. In this case, the iron core portion 66' may be provided at only one of the two end portions of the holes 67-69 or at both end portions.

[0207] Furthermore, in the first and second examples of the rotating electric machine 1 described above and examples of modifications and variations thereof, an end plate similar to the end plate 40 having the protruding portion 41 of the first embodiment may be provided on at least one of both axial end faces of the rotor core 61. For example, in the first example of the rotating electric machine 1 described above and examples of modifications and variations thereof, the end plate is provided on the end face on the axial range 2401 side. Furthermore, in the second example of the rotating electric machine 1 described above and examples of modifications and variations thereof, the end plate is provided on both axial end faces.

[0208] In addition, in the first and second examples of the rotating electric machine 1 described above and examples of their modifications and variations, the same idea as in the sixth example of the first embodiment of the rotating electric machine 1 may be adopted. Specifically, in the rotor core 61, the holes 67-69 may not be provided in a part of the entire range in the axial direction.

[0209] In addition, in the first and second examples of the rotating electric machine 1 described above and examples of modifications and variations thereof, holes 67A-67C, holes 68A-68C, and holes 69A-69C may be arranged (e.g., filled) with a material (e.g., resin) having a lower magnetic permeability than rotor core 21.

[0210] [Applications of rotating electrical machines] Next, with reference to FIG. 28, a specific application example of the rotating electric machine 1 according to the above-mentioned first to third embodiments will be described.

[0211] FIG. 28 is a diagram showing an example of an air conditioner 100 equipped with a rotating electric machine 1. As shown in FIG.

[0212] 28, the air conditioner 100 includes an outdoor unit 110, an indoor unit 120, and refrigerant paths 130 and 140. The air conditioner 100 operates a refrigeration cycle made up of the outdoor unit 110, the indoor unit 120, the refrigerant paths 130 and 140, etc., to adjust the temperature, humidity, etc., of the room in which the indoor unit 120 is installed.

[0213] The outdoor unit 110 is disposed outside a building whose temperature and the like are to be adjusted. The outdoor unit 110 is connected to one end of each of the refrigerant paths 130, 140, and draws in the refrigerant from one of the refrigerant paths 130, 140 and discharges the refrigerant to the other.

[0214] The indoor unit 120 is placed in a room of a building where the temperature, etc., is to be adjusted. The indoor unit 120 is connected to the other end of each of the refrigerant paths 130, 140, draws in refrigerant from one of the refrigerant paths 130, 140, and discharges the refrigerant to the other.

[0215] The refrigerant paths 130, 140 are, for example, configured by pipes, and connect the outdoor unit 110 and the indoor unit 120 so that the refrigerant can circulate between the outdoor unit 110 and the indoor unit 120.

[0216] The outdoor unit 110 includes refrigerant paths L1 to L6, oil paths L7 and L8, a four-way switching valve 111, an accumulator 112, a compressor 113, an oil separator 114, an outdoor heat exchanger 115, an outdoor expansion valve 116, and a blower 117.

[0217] The refrigerant paths L1 to L6 are configured as pipes, for example.

[0218] The refrigerant path L1 connects one end of the refrigerant path 130 outside the outdoor unit 110 to the four-way switching valve 111.

[0219] The refrigerant path L2 connects between the four-way switching valve 111 and the inlet of the compressor 113. The refrigerant path L2 includes refrigerant paths L21 and L22.

[0220] The refrigerant path L21 connects between the four-way switching valve 111 and the accumulator 112. The refrigerant path L22 connects between the accumulator 112 and the inlet of the compressor 113.

[0221] The refrigerant path L3 connects between the four-way switching valve 111 and the outlet of the compressor 113. The refrigerant path L3 includes refrigerant paths L31 and L32.

[0222] The refrigerant path L31 connects between the outlet of the compressor 113 and the oil separator 114. The refrigerant path L32 connects between the four-way switching valve 111 and the oil separator 114.

[0223] The refrigerant path L4 connects the four-way switching valve 111 and the outdoor heat exchanger 115.

[0224] The refrigerant path L5 connects the outdoor heat exchanger 115 and the outdoor expansion valve 116.

[0225] The refrigerant path L6 connects one end of the refrigerant path 140 outside the outdoor unit 110 and the outdoor expansion valve .

[0226] The oil path L7 is configured as, for example, a pipe, and is used to cause the oil separated by the oil separator 114 to flow into the refrigerant path L22 and return the oil to the compressor 113 through the refrigerant path L22.

[0227] In addition, for example, a liquid-phase refrigerant (liquid refrigerant) may be dissolved in the oil passing through the oil path L7. That is, not only the oil but also the liquid refrigerant flows through the oil path L7.

[0228] The oil path L8 is configured as, for example, a pipe, and is used to allow the oil containing the liquid refrigerant separated by the accumulator 112 to flow into the refrigerant path L22 and to return the oil to the compressor 113 through the refrigerant path L22.

[0229] The four-way switching valve 111 reverses the flow of circulating refrigerant between when the air conditioner 100 is in cooling operation and when it is in heating operation.

[0230] During cooling operation of the air conditioner 100, the four-way switching valve 111 connects the paths indicated by solid lines in Fig. 1. Specifically, during cooling operation of the air conditioner 100, the four-way switching valve 111 connects between the refrigerant path L1 and the refrigerant path L2, and between the refrigerant path L3 and the refrigerant path L4.

[0231] On the other hand, when the air conditioner 100 is in heating operation, the four-way switching valve 111 connects the paths indicated by the dotted lines in Fig. 1. Specifically, when the air conditioner 100 is in heating operation, the four-way switching valve 111 connects between the refrigerant path L4 and the refrigerant path L2, and between the refrigerant path L1 and the refrigerant path L3.

[0232] The accumulator 112 separates liquid refrigerant contained in the refrigerant drawn from the refrigerant path L21, and discharges the refrigerant from which a part or all of the liquid refrigerant has been removed to the refrigerant path L22. The liquid refrigerant separated in the accumulator 112 contains oil. The accumulator 112 is provided with an oil discharge port connected to the oil path L8, and the separated oil containing the refrigerant flows out into the oil path L8 through the oil discharge port and is returned to the compressor 113 through the oil path L8 and the refrigerant path L22.

[0233] The compressor 113 draws in the refrigerant from the refrigerant path L22, compresses it to a high pressure, and discharges it to the refrigerant path L31.

[0234] During cooling operation of the air conditioner 100, high-temperature, high-pressure refrigerant compressed by the compressor 113 flows into the outdoor heat exchanger 115 through refrigerant paths L3 and L4.

[0235] On the other hand, during heating operation of the air conditioner 100, the high-temperature, high-pressure refrigerant compressed by the compressor 113 flows through the refrigerant path L3 and the refrigerant path L1 into the refrigerant path 130 outside the outdoor unit 110. Then, the high-temperature, high-pressure refrigerant flows into the indoor unit 120 through the refrigerant path 130.

[0236] The oil separator 114 separates oil from the refrigerant flowing in from the refrigerant path L31, and causes the refrigerant from which a part or all of the oil has been separated and removed to flow into the refrigerant path L32. The oil separator 114 is also provided with an oil outlet connected to the oil path L7, and the oil separated from the refrigerant flows into the oil path L7 through the oil outlet and is returned to the compressor 113 through the oil path L7 and the refrigerant path L22.

[0237] The outdoor heat exchanger 115 exchanges heat between the outside air and the refrigerant passing through the inside. Specifically, the outdoor heat exchanger 115 is provided with a blower 117, and the outdoor heat exchanger 115 exchanges heat between the outside air blown by the blower 117 and the refrigerant flowing through the inside.

[0238] The blower 117 includes, for example, an axial flow fan as an impeller, and a rotating electric machine 1 that drives the axial flow fan.

[0239] When the air conditioner 100 is in cooling operation, the outdoor heat exchanger 115 causes the high-temperature, high-pressure refrigerant compressed by the compressor 113 and flowing in from the refrigerant path L4 to dissipate heat to the outside air, and causes the condensed and liquefied refrigerant (liquid refrigerant) to flow into the refrigerant path L5.

[0240] Furthermore, during heating operation of the air conditioner 100, the outdoor heat exchanger 115 causes the low-temperature, low-pressure liquid refrigerant flowing in from the refrigerant path L5 to absorb heat from the outside air, and causes the evaporated refrigerant to flow into the refrigerant path L4.

[0241] The outdoor expansion valve 116 is closed to a predetermined opening degree during heating operation of the air conditioner 100, and reduces the pressure of the refrigerant (liquid refrigerant) flowing in from the refrigerant path L6 to a predetermined pressure. On the other hand, the outdoor expansion valve 116 is fully open during cooling operation of the air conditioner 100, and passes the refrigerant (liquid refrigerant) from the refrigerant path L5 to the refrigerant path L6. The outdoor expansion valve 116 is, for example, a solenoid valve.

[0242] The indoor unit 120 includes an indoor expansion valve 121 , an indoor heat exchanger 122 , and a blower 123 .

[0243] The indoor expansion valve 121 is closed to a predetermined opening degree during cooling operation of the air conditioner 100, and reduces the pressure of the supercooled liquid refrigerant flowing in from the refrigerant path 140 to a predetermined pressure. On the other hand, during heating operation of the air conditioner 100, the indoor expansion valve 121 is fully open, and allows the refrigerant (liquid refrigerant) flowing out from the indoor heat exchanger 122 to pass toward the refrigerant path 140. The indoor expansion valve 121 is, for example, a solenoid valve.

[0244] The indoor heat exchanger 122 exchanges heat between the indoor air and the refrigerant passing through it. Specifically, by the action of the blower 123 mounted in the indoor unit 120, indoor air passes around the indoor heat exchanger 122, promoting heat exchange with the refrigerant inside the indoor heat exchanger 122. Then, by the action of the blower 123, the indoor air that has exchanged heat with the refrigerant inside the indoor heat exchanger 122 is sent out to the outside of the indoor unit 120, thereby realizing cooling or heating of the room.

[0245] The blower 123 includes, for example, a cross-flow fan as an impeller, and a rotating electric machine 1 that drives the cross-flow fan.

[0246] When the air conditioner 100 is in cooling operation, the indoor heat exchanger 122 causes the low-temperature, low-pressure liquid refrigerant decompressed by the indoor expansion valve 121 to absorb heat from the indoor air, thereby lowering the temperature of the indoor air.

[0247] On the other hand, during heating operation of the air conditioner 100, the indoor heat exchanger 122 causes the high-temperature, high-pressure refrigerant flowing in from the outdoor unit 110 through the refrigerant path 130 to radiate heat to the indoor air, thereby raising the temperature of the indoor air.

[0248] Incidentally, in the air conditioner 100, a mode may be adopted in which the rotating electric machine 1 is mounted on some of the compressor 113, the blower 117, and the blower 123, that is, on any one or two of them.

[0249] In this way, the rotating electric machine 1 according to the first to third embodiments described above can be mounted on the compressor 113, the blower 117, and the blower 123 mounted on the air conditioner 100 as a power source.

[0250] [Effect] Next, the operations of the rotating electric machine, compressor, blower, and refrigerator according to this embodiment will be described.

[0251] In a first aspect of this embodiment, the rotating electric machine includes a stator and a rotor that is rotatable about a rotation axis and includes a rotor core that is a powder magnetic core that is compression molded as an integral part. The rotating electric machine is, for example, the rotating electric machine 1 described above. The stator is, for example, the stator 10 described above. The rotation axis is, for example, the rotation axis AX described above. The rotor core is, for example, the rotor core 21, rotor core 51, or rotor core 61 described above. The rotor is, for example, the rotor 20, rotor 50, or rotor 60 described above. Specifically, the rotor core includes a first core portion having a first gap penetrating the entire range between one end and the other end in the axial direction, and a second core portion adjacent to the first core portion and the first gap, a portion of the entire range in the axial direction being an iron core, and a second gap being provided in the other portion adjacent in the axial direction. The first gap and the first core portion are, for example, the above-mentioned hole portion 27 (magnet slot) and the iron core portion 23 or the iron core portion 24. In this case, the second gap and the second core portion are, for example, the above-mentioned hole portion 28 and the iron core portion 25, or the hole portion 29 and the iron core portion 26. The first gap and the first core portion may also be the above-mentioned hole portion 56 (magnet slot) and the iron core portion 53. In this case, the second gap and the second core portion may be the above-mentioned hole portion 57 and core portion 54, or the hole portion 58 and core portion 55. Also, the first gap and the first core portion are the above-mentioned hole portions 67A, 67B and core portion 62 or core portion 63, or the above-mentioned hole portions 68A, 68B and core portion 63 or core portion 64, or the hole portions 69A, 69B and core portion 64 or core portion 65. In this case, the second gap and the second core portion are, for example, hole portion 67C and core portion 66A, or hole portion 68C and core portion 66B, or hole portion 69C and core portion 66C.

[0252] As a result, in the rotor core, the second core portion corresponding to the bridge portion can be provided only in a portion in the axial direction of the rotating electric machine, and the second gap portion adjacent to the first gap portion corresponding to the magnet slot or the slit as a flux barrier can be provided in the other portion in the axial direction. Therefore, even if the rotor core is separated into two parts by the first gap portion and the second gap portion in one axial cross section, the two separated parts can be connected by the second core portion in another cross section. As a result, the rotor core is not separated into a plurality of parts, and in the rotor core which is a powder magnetic core molded as an integral part, the second core portion corresponding to the bridge portion can be limited to only a portion in the axial direction of the rotating electric machine. Therefore, the rotating electric machine can suppress the magnetic flux that does not contribute to the output of the rotating electric machine in the rotor core using the powder magnetic core molded as an integral part.

[0253] In addition, in a second aspect of this embodiment, based on the first aspect described above, when viewed in the axial direction, the area of ​​the second core portion may be less than one-tenth of the area of ​​the first core portion.

[0254] This makes it possible to more appropriately suppress the magnetic flux that does not contribute to the output of the rotating electric machine.

[0255] In addition, in a third aspect of the present embodiment, on the premise of the first or second aspect described above, The second core portion may be integral with a continuous portion of the entire axial extent of the rotor core.

[0256] As a result, in the manufacturing process of the powder magnetic core, a molding die that is pulled out on both sides in the axial direction can be used, and the rotor core including the second gap portion formed in only part of the axial direction can be compression molded as a single unit.

[0257] In addition, in a fourth aspect of the present embodiment, on the premise of any one of the first to third aspects described above, the rotor core may include two first core parts separated by a first gap or a second gap. The two first core parts are, for example, the above-mentioned core parts 23 and 24. The two first core parts may be the above-mentioned two core parts 53 adjacent to each other in the circumferential direction. The two second core parts may be the above-mentioned core parts 62 and 63, or the core parts 63 and 64, or the core parts 64 and 65. The second core part may connect the two first core parts to each other at an end part in a direction perpendicular to the direction in which the two first core parts face each other. The direction perpendicular to the direction in which the two first core parts face each other is, for example, the axial direction of the above-mentioned rotating electric machine 1.

[0258] This allows the two first core portions to be completely separated by the first gap and the second gap in one axial portion of the rotor core, while the two first core portions can be connected to each other in the other axial portion, making it possible to realize the rotor core using a powder magnetic core that is compression molded as a single unit.

[0259] In addition, in a fifth aspect of the present embodiment, on the premise of any one of the first to fourth aspects described above, the rotor core may include two first core parts separated by a first gap or a second gap. The two first core parts are, for example, the above-mentioned core parts 23 and 24. The two first core parts may be the above-mentioned two core parts 53 adjacent to each other in the circumferential direction. The two second core parts may be the above-mentioned core parts 62 and 63, or the core parts 63 and 64, or the core parts 64 and 65. The second core part may connect the two first core parts at a center part in a direction perpendicular to the direction in which the two first core parts face each other. The direction perpendicular to the direction in which the two first core parts face each other is, for example, the axial direction of the above-mentioned rotating electric machine 1.

[0260] This allows the two first core portions to be completely separated by the first gap and the second gap in one axial portion of the rotor core, while the two first core portions can be connected to each other in the other axial portion, making it possible to realize the rotor core using a powder magnetic core that is compression molded as a single unit.

[0261] In addition, in a sixth aspect of this embodiment, based on any one of the first to fifth aspects described above, the second core portion may be provided in an intermediate portion between one end and the other end of the rotor core in the axial direction.

[0262] As a result, the second gap is open to both ends in the axial direction of the rotor core, and therefore, in the manufacturing process of the powder magnetic core, a molding die that is pulled out on both sides in the axial direction can be used to compression mold the rotor core as a whole, including the second gap that is formed only in a portion of the axial direction.

[0263] In addition, in a seventh aspect of this embodiment, based on any one of the first to sixth aspects described above, the second core portion may be provided in a partial range starting from one end of the entire axial range of the rotor core.

[0264] As a result, the second gap is open at the other end in the axial direction of the rotor core, and therefore, in the manufacturing process of the powder magnetic core, a molding die that is pulled out on both sides in the axial direction can be used to compression mold the rotor core as a whole, including the second gap that is formed only in a portion of the axial direction.

[0265] In an eighth aspect of the present embodiment, based on any one of the first to seventh aspects described above, the rotor core may include two second core portions. The two second core portions are, for example, the above-mentioned core portions 25 and 26. The two second core portions may also be the above-mentioned core portions 54 and 55. The two second core portions may be arranged in a range in which they do not overlap each other in the axial direction.

[0266] This makes it possible to improve the strength of the rotor core while suppressing magnetic flux that does not contribute to the output of the rotating electric machine.

[0267] In addition, in a ninth aspect of the present embodiment, based on any one of the first to seventh aspects described above, the rotor core may include two second core portions. The two second core portions are, for example, the above-mentioned core portions 25 and 26. The two second core portions may also be the above-mentioned core portions 54 and 55. The two second core portions may be arranged in an overlapping range in the axial direction.

[0268] This makes it possible to further suppress the magnetic flux that does not contribute to the output of the rotating electric machine.

[0269] In addition, in a tenth aspect of the present embodiment, based on any one of the first to ninth aspects described above, the second gap portion is provided in a range extending from one end of the rotor core to the second core portion in the axial direction, A retaining member may be provided at one axial end of the rotor core where the second gap is provided, for retaining the first core portion from the outside in the axial direction. The retaining member is, for example, an end plate 40.

[0270] This makes it possible to improve the strength of the rotor core while suppressing magnetic flux that does not contribute to the output of the rotating electric machine.

[0271] In addition, in an eleventh aspect of this embodiment, based on any one of the first to tenth aspects described above, the second core portion may have a thickness of 1 mm or more when viewed in the axial direction.

[0272] This makes it possible to manufacture the rotor core including the second core portion as a single unit by compression molding.

[0273] In a twelfth aspect of the present embodiment, based on any one of the first to eleventh aspects described above, the rotor core may include two first core portions divided in the circumferential direction by a first gap. The two first core portions divided in the circumferential direction are, for example, the two circumferentially adjacent core portions 53 described above. The two first core portions may have magnetic poles formed therein, which are divided by the first gap. The two first core portions may be connected by a second core portion.

[0274] This makes it possible to suppress magnetic flux that does not contribute to the output of a rotating electric machine in which magnetic poles are formed in two first core portions that are circumferentially partitioned by the first gap.

[0275] In addition, in a thirteenth aspect of this embodiment, based on the above-mentioned twelfth aspect, the second core portion may be provided adjacent to the first gap portion.

[0276] This makes it possible to suppress magnetic flux that does not contribute to the output of a rotating electric machine in which the second core portion is adjacent to the first gap portion.

[0277] In addition, in a fourteenth aspect of this embodiment, based on any one of the first to thirteenth aspects described above, the rotating electric machine may be an embedded magnet type in which a permanent magnet is arranged in the first gap portion.

[0278] This makes it possible to suppress leakage flux that does not contribute to the output of an embedded magnet type rotating electric machine.

[0279] In addition, in a fifteenth aspect of this embodiment, based on any one of the first to thirteenth aspects described above, the rotating electric machine may be a synchronous reluctance machine in which the first air gap, or a member arranged in the first air gap and having a lower magnetic permeability than the rotor core, functions as a magnetic barrier.

[0280] This makes it possible to suppress the magnetic flux that does not contribute to the output of the synchronous reluctance machine.

[0281] In addition, in a sixteenth aspect of the present embodiment, the compressor may be equipped with the rotating electric machine according to any one of the first aspect to the fifteenth aspect described above. The compressor is, for example, the compressor 113 described above.

[0282] This makes it possible to improve the output of the compressor.

[0283] In addition, in a seventeenth aspect of the present embodiment, the blower may be equipped with the rotating electric machine according to any one of the first to fifteenth aspects described above. The blower is, for example, the blower 117 or the blower 123 described above.

[0284] This makes it possible to improve the output of the blower.

[0285] In addition, in an eighteenth aspect of the present embodiment, the chiller may be equipped with the rotating electric machine according to any one of the first to fifteenth aspects described above. The chiller is, for example, the air conditioner 100 described above.

[0286] This makes it possible to improve the output of the refrigerator.

[0287] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. [Explanation of symbols]

[0288] 1 Rotating Electric Machine 10 Stator 11 Stator core 12 Windings 13 Back yoke 14 Teeth 20 Rotor 21 Rotor core 22 Permanent magnets 23~26 Core section 27~29 Hole 28A,28B Hole 29A,29B Hole 30 Rotational Axis 40 End plate 41 Protrusion 50 Rotor 51 Rotor core 52 Permanent Magnets 53~55 Core 56~58 Hole 60 Rotor 61 Rotor core 62~66 Core section 66A~66C Core 67 Hole 67A~67C Hole 68 Hole 68A~68C Hole 69 Hole 69A~69C Hole 100 Air conditioner 110 Outdoor unit 111 Four-way valve 112 Accumulator 113 Compressor 114 Oil separator 115 Outdoor heat exchanger 116 Outdoor expansion valve 117 Blower 120 Indoor unit 121 Indoor expansion valve 122 Indoor heat exchanger 123 Blower 130 Refrigerant path 140 Refrigerant path AX Rotation axis center

Claims

1. A stator; A rotor that is rotatable about a rotation axis and includes a rotor core that is a powder magnetic core that is integrally compression molded, The rotor core includes a first core portion having a first gap portion penetrating the entire range between one end and the other end in the axial direction, the entire range in the axial direction being an iron core when viewed along the axial direction, and a second core portion adjacent to the first core portion and the first gap portion, a portion of the entire range in the axial direction being an iron core, and a second gap portion being provided in another portion adjacent to the first core portion in the axial direction. Rotating electric motor.

2. When viewed in the axial direction, the area of ​​the second core portion is equal to or less than one-tenth of the area of ​​the first core portion. The rotating electric machine according to claim 1 .

3. The second core portion is integral with a continuous portion of the entire axial range of the rotor core.

3. A rotating electric machine according to claim 1 or 2.

4. the rotor core includes two first core portions separated by the first gap portion or the second gap portion, the second core portion connects the two first core portions to each other at ends in a direction perpendicular to a direction in which the two first core portions face each other; 3. A rotating electric machine according to claim 1 or 2.

5. the rotor core includes two first core portions separated by the first gap portion or the second gap portion, the second core portion connects the two first core portions to each other at a center portion in a direction perpendicular to a direction in which the two first core portions face each other; 3. A rotating electric machine according to claim 1 or 2.

6. The second core portion is provided in an intermediate portion between one end and the other end in the axial direction of the rotor core.

3. A rotating electric machine according to claim 1 or 2.

7. The second core portion is provided in a partial range starting from one end of the entire range in the axial direction of the rotor core.

3. A rotating electric machine according to claim 1 or 2.

8. the rotor core includes two of the second core portions, The two second core portions are arranged in a range in which they do not overlap with each other in the axial direction.

3. A rotating electric machine according to claim 1 or 2.

9. the rotor core includes two of the second core portions, The two second core portions are arranged in an overlapping range in the axial direction.

3. A rotating electric machine according to claim 1 or 2.

10. the second gap portion is provided in a range extending in the axial direction between one end of the rotor core and the second core portion, a retaining member that retains the first core portion from the outside in the axial direction at one axial end of the rotor core where the second gap portion is provided; 3. A rotating electric machine according to claim 1 or 2.

11. The second core portion has a thickness of 1 mm or more when viewed in the axial direction.

3. A rotating electric machine according to claim 1 or 2.

12. the rotor core includes two first core portions circumferentially divided by the first gap portion, The two first core portions are formed with magnetic poles partitioned by the first gap portion. The two first core portions are connected by the second core portion.

3. A rotating electric machine according to claim 1 or 2.

13. The second core portion is provided adjacent to the first gap portion. The rotating electric machine according to claim 12.

14. 3. A rotating electric machine according to claim 1, A permanent magnet is disposed in the first gap. Embedded magnet type rotating electric motor.

15. a synchronous reluctance machine in which the first air gap or a member arranged in the first air gap and having a lower magnetic permeability than the rotor core functions as a magnetic barrier; 3. A rotating electric machine according to claim 1 or 2.

16. The rotating electric machine according to claim 1 or 2 is mounted on the rotating electric machine. Compressor.

17. The rotating electric machine according to claim 1 or 2 is mounted on the rotating electric machine. Blower.

18. The rotating electric machine according to claim 1 or 2 is mounted on the rotating electric machine. Freezer.

Images