Rotor and rotating electric machine

Abstract

The rotor has, for each magnetic pole of the rotor core, first and second magnet housing regions, first and second outer periphery side magnetic gaps, first and second inner periphery side magnetic gaps, an outer periphery side central magnetic gap and an inner periphery side central magnetic gap, first and second outer periphery side bridge portions, first and second inner periphery side bridge portions, a central bridge portion, first and second protruding portions for holding permanent magnets. The first and second outer periphery side bridge portions are arranged so that the distance between them becomes narrower from the outer periphery side toward the inner periphery side of the rotor core. The first and second inner periphery side bridge portions are arranged so that the distance between them becomes narrower from the outer periphery side toward the inner periphery side of the rotor core, and are respectively connected to the first and second outer periphery side bridge portions.

Description

Technical Field

[0001] Embodiments of the present invention relate to a rotor of a rotary electric motor having permanent magnets, and a rotary electric motor having the rotor. Background Technology

[0002] In recent years, significant research and development of permanent magnets has led to the development of permanent magnets with high magnetic energy products. Permanent magnet rotary motors using these magnets are being applied as electric motors or generators in trams and automobiles. These rotary motors have a cylindrical stator and a cylindrical rotor rotatably supported inside the stator. The rotor has a rotor core and multiple permanent magnets embedded within it. These permanent magnets form multiple magnetic poles along the cylindrical direction of the rotor core.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-014322

[0006] Patent Document 2: Japanese Patent Application Publication No. 2014-060835 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In permanent magnet rotary motors like those described above, maintaining sufficient strength of the rotor core relative to centrifugal force becomes an important issue.

[0009] The purpose of embodiments of the present invention is to provide a rotor and a rotating electric motor that can maintain sufficient strength in the rotor core and prevent irreversible demagnetization of the permanent magnets.

[0010] Methods for solving problems

[0011] The rotor of the embodiment includes: a rotor core having a center of rotation; a plurality of permanent magnets disposed on the rotor core, forming a plurality of magnetic poles around the center of rotation; a first magnet receiving region and a second magnet receiving region disposed on each of the magnetic poles of the rotor core, each having an end disposed apart from each other in the circumferential direction of the rotor core near the outer peripheral surface of the rotor core, and each having another end disposed close to each other in a position disposed close to each other in the radial direction of the rotor core from the outer peripheral surface of the rotor core, the first magnet receiving region and the second magnet receiving region receiving each of the permanent magnets; a first peripheral magnetic gap and a second peripheral magnetic gap disposed on the rotor core. Each of the magnetic poles of the rotor core is connected to one end of the first magnet receiving region and the second magnet receiving region, and opens outward through the outer periphery of the rotor core; a first inner circumferential magnetic gap and a second inner circumferential magnetic gap are disposed on each of the magnetic poles of the rotor core and are connected to the other end of the first magnet receiving region and the second magnet receiving region, respectively; an outer circumferential central magnetic gap and an inner circumferential central magnetic gap are disposed on each of the magnetic poles of the rotor core, located radially on the outer and inner circumferential sides of the rotor core, separated from each other by the first inner circumferential magnetic gap and the second inner circumferential magnetic gap; a first outer circumferential bridging portion and a second outer circumferential bridging portion... In the rotor core, each of the magnetic poles is located between the first inner circumferential magnetic gap and the outer circumferential central magnetic gap, and between the second inner circumferential magnetic gap and the outer circumferential central magnetic gap, respectively, and is configured such that the spacing between them narrows from the outer circumferential side to the inner circumferential side of the rotor core. The first outer circumferential bridging portion and the second outer circumferential bridging portion are connected to regions in the rotor core that are further outward than the first magnet receiving region and the second magnet receiving region, the first outer circumferential magnetic gap and the second outer circumferential magnetic gap, the first inner circumferential magnetic gap and the second inner circumferential magnetic gap, and the outer circumferential central magnetic gap. The first inner circumferential bridging portion and the second inner circumferential bridging portion, in the rotor core... Each of the magnetic poles of the rotor core is located between the first inner circumferential magnetic gap and the inner circumferential central magnetic gap, and between the second inner circumferential magnetic gap and the inner circumferential central magnetic gap, respectively, and is configured such that the spacing between them narrows from the outer circumferential side of the rotor core toward the inner circumferential side. The first inner circumferential bridging portion and the second inner circumferential bridging portion are respectively connected to the first outer circumferential bridging portion and the second outer circumferential bridging portion, and are connected to the region of the rotor core that is closer to the inner circumferential side than the first magnet receiving region and the second magnet receiving region, the first outer circumferential magnetic gap and the second outer circumferential magnetic gap, the first inner circumferential magnetic gap and the second inner circumferential magnetic gap, and the inner circumferential central magnetic gap;A central bridging portion is disposed at each of the magnetic poles of the rotor core, located between the outer peripheral central magnetic gap and the inner peripheral central magnetic gap, and spanned between the connecting portion of the first outer peripheral bridging portion and the first inner peripheral bridging portion and the connecting portion of the second outer peripheral bridging portion and the second inner peripheral bridging portion; a first protrusion for holding a permanent magnet is disposed at each of the magnetic poles of the rotor core, protruding from the connecting portion of the first outer peripheral bridging portion and the first inner peripheral bridging portion into the first inner peripheral magnetic gap and opposite to the first magnet receiving area; and a second protrusion for holding a permanent magnet is disposed at each of the magnetic poles of the rotor core, protruding from the connecting portion of the second outer peripheral bridging portion and the second inner peripheral bridging portion into the second inner peripheral magnetic gap and opposite to the second magnet receiving area. In the first outer peripheral bridging portion, the portion that forms the boundary with the outer peripheral central magnetic gap includes a straight section extending in a straight line. In the first inner peripheral bridging portion, the portion that forms the boundary with the inner peripheral central magnetic gap includes a linearly extending section. In the second outer peripheral bridging portion, the portion that forms the boundary with the outer peripheral central magnetic gap includes a linearly extending section. In the second inner peripheral bridging portion, the portion that forms the boundary with the inner peripheral central magnetic gap includes a linearly extending section. In the central bridging portion, the portion that forms the boundary with the inner peripheral central magnetic gap includes a linearly extending section that extends along a direction orthogonal to an imaginary straight line containing the linear sections of each of the first outer peripheral bridging portion, the first inner peripheral bridging portion, the second outer peripheral bridging portion, and the second inner peripheral bridging portion. The intersection point of the dummy straight line containing the first outer peripheral bridging portion and the dummy straight line containing the central bridging portion is located further away from the first magnet receiving area than the intersection point of the dummy straight line containing the first inner peripheral bridging portion and the dummy straight line containing the central bridging portion. Similarly, the intersection point of the dummy straight line containing the second outer peripheral bridging portion and the dummy straight line containing the central bridging portion is located further away from the second magnet receiving area than the intersection point of the dummy straight line containing the second inner peripheral bridging portion and the dummy straight line containing the central bridging portion.

[0012] The rotary electric motor of the embodiment includes a rotor as described in technical solution 1 or 2, and a stator that rotatably supports the rotor. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of a permanent magnet rotary motor according to one embodiment.

[0014] Figure 2 This is a cross-sectional view showing a portion of the rotor core in one embodiment.

[0015] Figure 3 It is Figure 2 A portion of the image is shown in enlarged form.

[0016] Figure 4 It means Figure 3 The diagram shows examples of different width dimensions for the bridging sections. Detailed Implementation

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, common components are labeled with the same reference numerals throughout the embodiments, and repeated descriptions are omitted. Additionally, the drawings are schematic diagrams intended to facilitate understanding of the embodiments, and their shapes, sizes, proportions, etc., may differ from actual devices; however, these can be appropriately modified with reference to the following description and known techniques.

[0018] Figure 1 This is a cross-sectional view of a permanent magnet rotary electric motor according to one embodiment. Figure 2 This is an enlarged cross-sectional view showing the first magnetic pole portion of the rotor core in one embodiment.

[0019] like Figure 1 As shown, the rotary motor 1 is configured, for example, as an internal rotor type rotary motor, comprising an annular or cylindrical stator 10 supported on a fixed frame (not shown), and a rotor 20 having a central axis (rotation center) C inside the stator 10 and being rotatably supported coaxially with the stator 10. The rotary motor 1 is suitably used as a drive motor or generator, for example, in hybrid electric vehicles (HEVs) and electric vehicles (EVs).

[0020] The stator 10 has a cylindrical stator core 11 and an armature winding (coil) 12 wound around the stator core 11. The stator core 11 is constructed by concentrically stacking multiple ring-shaped electromagnet steel sheets (iron chips) of magnetic material such as silicon steel. Multiple slots 13 are formed on the inner periphery of the stator core 11.

[0021] The slots 13 are arranged at equal intervals along the circumference of the stator core 11. Each slot 13 opens into the inner circumferential surface of the stator core 11 and extends radially from that inner circumferential surface. Each slot 13 extends along the entire axial length of the stator core 11. Accompanying the formation of these slots 13, a plurality (e.g., 48) of stator teeth 14 facing the rotor 20 are formed in the inner circumference of the stator core 11. Armature windings 12 are inserted into each slot 13 and wound around each stator tooth 14. By having current flowing in the armature windings 12, a predetermined linkage magnetic flux is formed in the stator 10 (stator teeth 14).

[0022] The rotor 20 has a cylindrical rotating shaft 21 rotatably supported at both ends by bearings (not shown), a cylindrical rotor core 22 fixed to approximately the axial center of the rotating shaft 21, and a plurality of permanent magnets M1 and M2 embedded in the rotor core 22. The rotor 20 is coaxially arranged inside the stator 10 with a small gap (air gap) between it and the inner circumferential surface of the stator 10. The outer circumferential surface of the rotor 20 faces the inner circumferential surface of the stator 10 with a small gap. The rotor core 22 has an inner hole 23 formed coaxially with the central axis C. The rotating shaft 21 is inserted through and fitted into the inner hole 23 and extends coaxially with the rotor core 22.

[0023] The rotor core 22 is constructed as a laminate of multiple concentrically stacked annular electromagnetic steel plates (iron chips) of magnetic material such as silicon steel. The rotor core 22 has the aforementioned central axis C extending along the stacking direction of the iron chips, and an outer peripheral surface 22x opposite to the inner peripheral surface of the stator 10 through a small gap (air gap).

[0024] The rotor core 22 has multiple magnetic poles, for example, eight magnetic poles. In the rotor core 22, the axis that passes through the central axis C and the boundary between adjacent magnetic poles in the circumferential direction and extends radially along the rotor core 22 is called the q-axis. The axes electrically spaced 90° from these q-axis in the circumferential direction—in other words, lines extending radially from the center of the circumference of each magnetic pole through the central axis C—are respectively called d-axis. The direction in which the linked magnetic flux formed by the stator 10 easily flows is called the q-axis. These d-axis and q-axis are alternately arranged in the circumferential direction of the rotor core 22 and in a predetermined phase. One magnetic pole quantity of the rotor core 22 refers to the region between two adjacent q-axis in the circumferential direction (a circumferential angle region of 1 / 8 circumference). The circumferential center of a magnetic pole is called the d-axis.

[0025] like Figure 1 as well as Figure 2 As shown, in each magnetic pole of the rotor core 22, the magnet receiving area (first magnet receiving area) 31 that houses the permanent magnet M1 and the magnet receiving area (second magnet receiving area) 41 that houses the permanent magnet M2 are arranged in symmetrical positions sandwiched between them and the d-axis.

[0026] The magnet receiving regions 31 and 41 have one end 31a and 41a positioned near the outer peripheral surface 22x of the rotor core 22, separated from each other by a predetermined distance L1 in the circumferential direction of the rotor core 22, and the other end 31b and 41b positioned close to each other at a position radially separated from the outer peripheral surface 22x of the rotor core 22 by a predetermined distance L2. They are arranged in a generally V-shape, with the distance from the d-axis gradually increasing from the inner peripheral end towards the outer peripheral end. The angle θ of inclination of the magnet receiving regions 31 and 41 relative to the d-axis is less than 90 degrees.

[0027] The magnet receiving region 31 has a rectangular shape corresponding to the cross-sectional shape of the permanent magnet M1 and is formed by extending axially through the rotor core 22. The magnet receiving region 31 has a periphery 31c located on the outer periphery of the rotor core 22 and a periphery 31d located on the inner periphery of the rotor core 22 between one end 31a and the other end 31b. The permanent magnet M1 is housed within this magnet receiving region 31. Accompanying this housing, the non-magnetic pole surfaces M1a and M1b at both ends of the permanent magnet M1 in the longitudinal direction correspond to one end 31a and the other end 31b of the magnet receiving region 31, respectively, and the magnetic pole surfaces M1c and M1d along the longitudinal direction of the permanent magnet M1 abut against the periphery 31c and 31d of the magnet receiving region 31, respectively. The permanent magnet M1 is fixed to the rotor core 22, for example, by adhesive.

[0028] The magnet receiving region 41 has a rectangular shape corresponding to the cross-sectional shape of the permanent magnet M2 and is formed by extending axially through the rotor core 22. The magnet receiving region 41 has a periphery 41c located on the outer periphery of the rotor core 22 and a periphery 41d located on the inner periphery of the rotor core 22 between one end 41a and the other end 41b. The permanent magnet M2 is received in this magnet receiving region 41. Along with this reception, the non-magnetic pole surfaces M2a and M2b at both ends of the permanent magnet M2 in the longitudinal direction correspond to one end 41a and the other end 41b of the magnet receiving region 41, respectively, and the magnetic pole surfaces M2c and M2d along the longitudinal direction of the permanent magnet M2 abut against the periphery 41c and 41d of the magnet receiving region 41, respectively. The permanent magnet M2 is fixed to the rotor core 22, for example, by adhesive.

[0029] The permanent magnets M1 and M2 are formed into elongated flat plates with a rectangular cross-section and have a length approximately equal to the axial length of the rotor core 22. The permanent magnets M1 and M2 can also be formed by combining multiple magnets that are divided axially, in which case the total length of the multiple magnets is approximately equal to the axial length of the rotor core 22.

[0030] Each magnetic pole of the rotor core 22 is provided with an outer peripheral magnetic gap (first outer peripheral magnetic gap) 32 that is connected to one end 31a of the magnet receiving region 31 in a connected state, and an outer peripheral magnetic gap (second outer peripheral magnetic gap) 42 that is connected to one end 41a of the magnet receiving region 41 in a connected state.

[0031] The outer peripheral magnetic gap 32 is a magnetic gap containing non-magnetic materials such as air, and opens outward from the rotor core 22 through the cutout hole 34 formed on the outer peripheral surface 22x of the rotor core 22. The outer peripheral magnetic gap 42 is a magnetic gap containing non-magnetic materials such as air, and opens outward from the rotor core 22 through the cutout hole 44 formed on the outer peripheral surface 22x of the rotor core 22. These outer peripheral magnetic gaps 32 and 42 are formed axially through the rotor core 22.

[0032] Each magnetic pole of the rotor core 22 is provided with an inner circumferential magnetic gap (first inner circumferential magnetic gap) 33 that is connected to the other end 31b of the magnet receiving area 31 in a connected state, and an inner circumferential magnetic gap (second inner circumferential magnetic gap) 43 that is connected to the other end 41b of the magnet receiving area 41 in a connected state.

[0033] The inner peripheral magnetic gap 33 is a magnetic gap containing a non-magnetic material such as air, and has: a periphery 33a extending from the periphery 31c of the magnet receiving region 31 toward the d-axis; a periphery 33b extending toward the inner peripheral side from the periphery 33a and gradually narrowing in distance from the d-axis while inclined relative to the d-axis and connected to the protrusion 63 described later; a periphery 33c extending toward the inner hole 23 from the protrusion 63 and gradually narrowing in distance from the d-axis while inclined relative to the d-axis; a periphery 33d facing the inner hole 23 while bending back from the periphery 33c toward the magnet receiving region 31; a periphery 33e extending from the periphery 33d toward the magnet receiving region 31; and a periphery 33f connecting the periphery 33e and the periphery 31d of the magnet receiving region 31. The inner peripheral magnetic gap 33 is formed by axially penetrating the rotor core 22.

[0034] The inner peripheral magnetic gap 43 is a magnetic gap containing a non-magnetic body such as air, and has: a periphery 43a extending from the periphery 41c of the magnet receiving region 41 toward the d-axis; a periphery 43b extending toward the inner peripheral side from the periphery 43a and gradually narrowing at the interval with the d-axis while inclined relative to the d-axis and connected to the protrusion 73 described later; a periphery 43c extending toward the inner hole 23 from the protrusion 73 and gradually narrowing at the interval with the d-axis while inclined relative to the d-axis; a periphery 43d facing the inner hole 23 while bending back from the periphery 43c toward the magnet receiving region 41; a periphery 43e extending from the periphery 43d toward the magnet receiving region 41; and a periphery 43f connecting the periphery 43e and the periphery 41d of the magnet receiving region 41. The inner peripheral magnetic gap 43 is formed by axially penetrating the rotor core 22.

[0035] exist Figure 2 as well as Figure 3 The diagram shows an example of asymmetry where the shapes of the peripheral portions of the inner peripheral magnetic gaps 33 and 43 are slightly different from each other in the portions adjacent to the outer peripheral bridging portions 61 and 71 described later. The shapes of the peripheral portions of these inner peripheral magnetic gaps 33 and 43 are not limited to this asymmetry and may also be identical.

[0036] In each magnetic pole of the rotor core 22, a magnet retaining protrusion 35 for retaining the permanent magnet M1 is disposed between the periphery 31d on the side of one end 31a of the magnet receiving region 31 and the outer peripheral magnetic gap 32. In each magnetic pole of the rotor core 22, a magnet retaining protrusion 45 for retaining the permanent magnet M2 is disposed between the periphery 41d on the side of one end 41a of the magnet receiving region 41 and the outer peripheral magnetic gap 42.

[0037] The outer peripheral magnetic gap 32 and the inner peripheral magnetic gap 33 function as flux barriers to prevent short circuits of the magnetic flux (referred to as magnet flux) at both ends of the permanent magnet M1 within the magnet housing region 31, and also contribute to the weight reduction of the rotor core 22. The outer peripheral magnetic gap 42 and the inner peripheral magnetic gap 43 function as flux barriers to prevent short circuits of the magnetic flux (magnet flux) at both ends of the permanent magnet M2 within the magnet housing region 41, and also contribute to the weight reduction of the rotor core 22.

[0038] The outer peripheral magnetic gaps 32 and 42, which are open to the outside of the rotor core 22 through the cut holes 34 and 44, suppress short circuits of the magnetic flux of the magnets inside the rotor core 22. As a result, the performance of the rotary motor 1 is improved, thereby enabling the miniaturization and weight reduction of the rotary motor 1.

[0039] In each magnetic pole of the rotor core 22, the inner circumferential magnetic gaps 33 and 43 are positioned between each other, while the outer circumferential central magnetic gap 51 and the inner circumferential central magnetic gap 52 are separately arranged on the outer and inner circumferential sides of the rotor core 22 in the radial direction.

[0040] The outer peripheral center magnetic gap 51 is a magnetic gap containing a non-magnetic body such as air, and has a trapezoidal shape. The trapezoidal shape is formed by a periphery 51a opposite to the outer peripheral surface 22x and orthogonal to the d-axis, a periphery 51b opposite to the periphery 33b of the inner peripheral magnetic gap 33 and inclined relative to the d-axis at a distance from the outer peripheral side to the inner peripheral side, a periphery 51c opposite to the inner peripheral center magnetic gap 52 and orthogonal to the d-axis, and a periphery 51d opposite to the periphery 43b of the inner peripheral magnetic gap 43 and inclined relative to the d-axis at a distance from the outer peripheral side to the inner peripheral side. The outer peripheral center magnetic gap 51 is formed by axially penetrating the rotor core 22.

[0041] The inner circumferential central magnetic gap 52 is a magnetic gap containing a non-magnetic body such as air, and has a trapezoidal shape. This trapezoidal shape is formed by a periphery 52a that is opposite to the periphery 51c of the inner circumferential central magnetic gap 51 and orthogonal to the d-axis, a periphery 52b that is opposite to the periphery 33c of the inner circumferential magnetic gap 33 and is inclined relative to the d-axis in a state that narrows from the outer circumferential side to the inner circumferential side at a distance from the d-axis, a periphery 52c that is opposite to the inner hole 23 and orthogonal to the d-axis, and a periphery 52d that is opposite to the periphery 43c of the inner circumferential magnetic gap 43 and is inclined relative to the d-axis in a state that narrows from the outer circumferential side to the inner circumferential side at a distance from the d-axis. The inner circumferential central magnetic gap 52 is formed by axially penetrating the rotor core 22.

[0042] In each magnetic pole of the rotor core 22, a columnar outer peripheral bridging portion (first outer peripheral bridging portion) 61 is formed between the periphery 33b of the inner peripheral magnetic gap 33 and the periphery 51b of the outer peripheral central magnetic gap 51, and a columnar outer peripheral bridging portion (second outer peripheral bridging portion) 71 is formed between the periphery 43b of the inner peripheral magnetic gap 43 and the periphery 51d of the outer peripheral central magnetic gap 51. These outer peripheral bridging portions 61 and 71 are arranged obliquely relative to the d-axis in a manner that follows the trapezoidal shape of the outer peripheral central magnetic gap 51 and narrows from the outer peripheral side to the inner peripheral side of the rotor core 22 at intervals between each other, and are connected to a fan-shaped region 22a in the rotor core 22 that is further outward than the magnet receiving regions 31 and 41, the outer peripheral magnetic gaps 32 and 42, the inner peripheral magnetic gaps 33 and 43, and the outer peripheral central magnetic gap 51. Region 22a is referred to as the outer peripheral core section 22a.

[0043] A magnetic flux barrier of one layer is formed by the magnet receiving areas 31 and 41, the outer peripheral magnetic gaps 32 and 42, the inner peripheral magnetic gaps 33 and 43, and the outer peripheral central magnetic gap 51.

[0044] In each magnetic pole of the rotor core 22, a columnar inner peripheral bridging portion (first inner peripheral bridging portion) 62 is formed between the periphery 33c of the inner peripheral magnetic gap 33 and the periphery 52b of the inner peripheral central magnetic gap 52, and a columnar inner peripheral bridging portion (second inner peripheral bridging portion) 72 is formed between the periphery 43c of the inner peripheral magnetic gap 43 and the periphery 52d of the inner peripheral central magnetic gap 52. These inner peripheral bridging portions 62 and 72 are arranged obliquely relative to the d-axis in a trapezoidal shape along the inner peripheral central magnetic gap 52 and in a manner that narrows from the outer peripheral side to the inner peripheral side of the rotor core 22 at intervals between each other. They are connected to the outer peripheral bridging portions 61 and 71, respectively, and are connected to the region 22b in the rotor core 22 that is closer to the inner peripheral side than the magnet receiving regions 31 and 41, the outer peripheral magnetic gaps 32 and 42, the inner peripheral magnetic gaps 33 and 43, and the inner peripheral central magnetic gap 52. The inner peripheral region 22b is referred to as the inner peripheral core portion 22b.

[0045] The fan-shaped outer peripheral core 22a, which is separated from the inner peripheral core 22b through the cut holes 34, 44 and the magnet receiving areas 31, 41, is connected to the inner peripheral core 22b through the outer peripheral bridging portions 61, 71 and the inner peripheral bridging portions 62, 72 connected thereto. Therefore, even if a large centrifugal force is applied to the outer peripheral core 22a, the outer peripheral core 22a can be stably supported from the inner peripheral core 22b side.

[0046] In each magnetic pole of the rotor core 22, a columnar central bridging portion 80 is formed between the periphery 51c of the outer peripheral central magnetic gap 51 and the periphery 52a of the inner peripheral central magnetic gap 52. This central bridging portion 80 is mounted between the connecting portion 60 of the outer peripheral bridging portion 61 and the inner peripheral bridging portion 62, and between the connecting portion 70 of the outer peripheral bridging portion 71 and the inner peripheral bridging portion 72, and connects the connecting portions 60 and 70.

[0047] The outer peripheral bridging portions 61 and 71 are arranged in a trapezoidal shape, gradually narrowing from the outer peripheral side to the inner peripheral side at intervals with each other. Similarly, the inner peripheral bridging portions 62 and 72 are arranged in a trapezoidal shape, gradually narrowing from the outer peripheral side to the inner peripheral side at intervals with each other. The connecting portion 60 of the outer peripheral bridging portion 61 and the inner peripheral bridging portion 62, and the connecting portion 70 of the outer peripheral bridging portion 71 and the inner peripheral bridging portion 72 are connected by the central bridging portion 80. Thus, even if strong bending stress is applied to the outer peripheral bridging portions 61 and 71 and the inner peripheral bridging portions 62 and 72, the deformation of each bridging portion can be suppressed with sufficient strength.

[0048] The outer peripheral bridging portion 61, at its boundary with the outer peripheral central magnetic gap 51 (the periphery 51b of the outer peripheral central magnetic gap 51), includes a straight portion 61x extending in a straight line with the same slope as the inclination of the outer peripheral bridging portion 61 relative to the d-axis. The inner peripheral bridging portion 62, at its boundary with the inner peripheral central magnetic gap 52 (the periphery 52b of the inner peripheral central magnetic gap 52), includes a straight portion 62x extending in a straight line with the same slope as the inclination of the inner peripheral bridging portion 62 relative to the d-axis.

[0049] The outer peripheral bridging portion 71, at its boundary with the outer peripheral central magnetic gap 51 (the periphery 51d of the outer peripheral central magnetic gap 51), includes a straight portion 71x extending in a straight line with the same slope as the inclination of the outer peripheral bridging portion 71 relative to the d-axis. The inner peripheral bridging portion 72, at its boundary with the inner peripheral central magnetic gap 52 (the periphery 52d of the inner peripheral central magnetic gap 52), includes a straight portion 72x extending in a straight line with the same slope as the inclination of the inner peripheral bridging portion 72 relative to the d-axis.

[0050] The central bridging portion 80 includes a straight section 80x at the boundary portion (peripheral edge 52a) 80x of the inner peripheral central magnetic gap 52. This straight section 80x extends along a direction orthogonal to the imaginary straight lines A1, B1, A2, B2 that include the straight sections 61x, 62x, 71x, and 72x of the outer peripheral bridging portion 61, the inner peripheral bridging portion 62, the outer peripheral bridging portion 71, and the inner peripheral bridging portion 72, respectively.

[0051] The intersection point A1x of the dummy line A1 of the straight portion 61x of the outer peripheral bridging portion 61 and the dummy line D of the straight portion 80x of the central bridging portion 80, and the intersection point B1x of the dummy line B1 of the straight portion 62x of the inner peripheral bridging portion 62 and the dummy line D of the straight portion 80x of the central bridging portion 80, are located at a position farther from the magnet receiving area 31. The intersection point A2x of the dummy line A2 of the straight portion 71x of the outer peripheral bridging portion 71 and the dummy line D of the straight portion 80x of the central bridging portion 80, and the intersection point B2x of the dummy line B2 of the straight portion 72x of the inner peripheral bridging portion 72 and the dummy line D of the straight portion 80x of the central bridging portion 80, are located at a position farther from the magnet receiving area 41.

[0052] That is, in the circumferential direction of the rotor core 22, the outer peripheral bridging portion 61 is positioned further along the d-axis than the inner peripheral bridging portion 62. As a result, the distance G1 between the other end 31b of the magnet receiving region 31 and the outer peripheral bridging portion 61 is increased. Because the distance G1 between the other end 31b of the magnet receiving region 31 and the outer peripheral bridging portion 61 is increased, the permanent magnet M1 can be easily loaded into the magnet receiving region 31 without being hindered by the presence of the outer peripheral bridging portion 61 during the operation of loading the permanent magnet M1 into the magnet receiving region 31. As a result, the workability during the manufacture of the rotor 20 is improved.

[0053] In the circumferential direction of the rotor core 22, the outer peripheral bridging portion 71 is positioned further along the d-axis than the inner peripheral bridging portion 72. As a result, the distance G2 between the other end 41b of the magnet receiving region 41 and the outer peripheral bridging portion 71 is increased. Due to the increased distance G2, when loading the permanent magnet M2 into the magnet receiving region 41, the presence of the outer peripheral bridging portion 71 can facilitate the loading of the permanent magnet M2 into the magnet receiving region 41. This also improves the workability of manufacturing the rotor 20.

[0054] Since the connecting portion 60 of the outer peripheral side bridging portion 61 and the inner peripheral side bridging portion 62 is connected to the connecting portion 70 of the outer peripheral side bridging portion 71 and the inner peripheral side bridging portion 72 through the central bridging portion 80, even if a strong bending stress is applied to the connecting portions 60 and 70, the deformation of each bridging portion caused thereby can be suppressed with sufficient strength.

[0055] The width dimension E1 of the outer peripheral bridging portion 61 in the circumferential direction of the rotor core 22 is defined as the width between the portion of the outer peripheral bridging portion 61 that forms the boundary with the inner peripheral magnetic gap 33 (peripheral edge 33b of the inner peripheral magnetic gap 33) and the portion that forms the boundary with the outer peripheral central magnetic gap 51 (peripheral edge 51b of the outer peripheral central magnetic gap 51). The width dimension F1 of the inner peripheral bridging portion 62 in the circumferential direction of the rotor core 22 is defined as the width between the portion of the inner peripheral bridging portion 62 that forms the boundary with the inner peripheral magnetic gap 33 (peripheral edge 33c of the inner peripheral magnetic gap 33) and the portion that forms the boundary with the inner peripheral central magnetic gap 52 (peripheral edge 52b of the inner peripheral central magnetic gap 52).

[0056] The width dimension E2 of the outer peripheral bridging portion 71 in the circumferential direction of the rotor core 22 is defined as the width dimension between the portions of the outer peripheral bridging portion 71 that form the boundary with the inner peripheral magnetic gap 43 (peripheral edge 43b of the inner peripheral magnetic gap 43) and the portions that form the boundary with the outer peripheral central magnetic gap 51 (peripheral edge 51d of the outer peripheral central magnetic gap 51). The width dimension F2 of the inner peripheral bridging portion 72 in the circumferential direction of the rotor core 22 is defined as the width dimension between the portions of the inner peripheral bridging portion 72 that form the boundary with the inner peripheral magnetic gap 43 (peripheral edge 43c of the inner peripheral magnetic gap 43) and the portions that form the boundary with the inner peripheral central magnetic gap 52 (peripheral edge 52d of the inner peripheral central magnetic gap 52).

[0057] The width dimensions E1, F1, E2, and F2 of each bridging portion are set as finely as possible to reduce the leakage of magnetic flux. Furthermore, while the width dimensions E1, F1, E2, and F2 of each bridging portion are set as finely as possible, in order to maintain sufficient strength of each bridging portion relative to the strong bending stress applied to each bridging portion, the minimum value of the width dimension F1 of the inner peripheral bridging portion 62 on the side subjected to greater bending stress in the outer peripheral bridging portion 61 and the inner peripheral bridging portion 62 is set to be the same as or larger than the minimum value of the width dimension E1 of the outer peripheral bridging portion 61. Similarly, the minimum value of the width dimension F2 of the inner peripheral bridging portion 72 on the side subjected to greater bending stress in the outer peripheral bridging portion 71 and the inner peripheral bridging portion 72 is set to be the same as or larger than the minimum value of the width dimension E2 of the outer peripheral bridging portion 71.

[0058] The width of the radial center bridging portion 80 of the rotor core 22 is set to be approximately the same as the width F1 and F2 of the inner circumferential bridging portions 62 and 72.

[0059] exist Figure 2 as well as Figure 3 In the example, it is shown that the minimum value of the width dimension F1 of the inner peripheral bridging portion 62 is set to be approximately the same as the minimum value of the width dimension E1 of the outer peripheral bridging portion 61, and the minimum value of the width dimension F2 of the inner peripheral bridging portion 72 is set to be approximately the same as the minimum value of the width dimension E2 of the outer peripheral bridging portion 71. Figure 4 As shown, the minimum value of the width dimension F1 of the inner peripheral bridging portion 62 can be set to be larger than the minimum value of the width dimension E1 of the outer peripheral bridging portion 61, and the minimum value of the width dimension F2 of the inner peripheral bridging portion 72 can be set to be larger than the minimum value of the width dimension E2 of the outer peripheral bridging portion 71.

[0060] [Regarding protrusions 63 and 73 for retaining permanent magnets]

[0061] Each magnetic pole of the rotor core 22 is provided with a permanent magnet holding protrusion (first protrusion) 63 that protrudes from the connecting portion 60 of the outer peripheral bridging portion 61 and the inner peripheral bridging portion 62 into the periphery 33b and 33c of the inner peripheral magnetic gap 33, and a permanent magnet holding protrusion (second protrusion) 73 that protrudes from the connecting portion 70 of the outer peripheral bridging portion 71 and the inner peripheral bridging portion 72 into the periphery 43b and 43c of the inner peripheral magnetic gap 43.

[0062] The protrusion 63 is a component for restricting the movement of the permanent magnet M1 within the magnet receiving region 31. It extends in a columnar shape towards the other end 31b of the magnet receiving region 31, inclined at approximately the same angle as the inclination of the magnet receiving region 31 relative to the d-axis. Its front end 63a faces the non-magnetic pole surface M1b of the permanent magnet M1 within the magnet receiving region 31. The protrusion 73 is a component for restricting the movement of the permanent magnet M2 within the magnet receiving region 41. It also extends in a columnar shape towards the other end 41b of the magnet receiving region 41, inclined at approximately the same angle as the inclination of the magnet receiving region 41 relative to the d-axis. Its front end 73a faces the non-magnetic pole surface M2b of the permanent magnet M2 within the magnet receiving region 41. The movement of the permanent magnet M2 within the magnet receiving region 41 is restricted by this protrusion 73.

[0063] exist Figure 2 as well as Figure 3 In the middle, the length of the protrusion direction and the width in the direction orthogonal to the protrusion direction of the protrusions 63 and 73, and the shapes of the protrusions 63 and 73 can be the same or different from each other.

[0064] When the rotor core 22 and each permanent magnet M1 and M2 become hot due to the high load operation of the rotating motor 1, a demagnetizing field based on field weakening control or the like is sometimes applied from the stator 10 to the rotor core 22.

[0065] In this case, it can be considered that the magnetic flux of the demagnetizing field passing through the permanent magnet M1 is directed towards the front end 63a of the protrusion 63 for holding the permanent magnet. However, since the outer peripheral bridging portion 61 and the inner peripheral bridging portion 62 of the supporting protrusion 63 are in a state of magnetic flux saturation and blockage at their outer peripheral and inner peripheral ends, in other words, in a state of high magnetic resistance, it is possible to prevent the magnetic flux of the demagnetizing field passing through the permanent magnet M1 from flowing into the protrusion 63 through the outer peripheral bridging portion 61 and the inner peripheral bridging portion 62. Furthermore, the undesirable situation of the magnetic flux of the demagnetizing field passing through the protrusion 63 and grazing the permanent magnet M1 will not occur, thus preventing irreversible demagnetization in the permanent magnet M1. That is, the anti-demagnetizing performance of the permanent magnet M1 is improved.

[0066] Similarly, considering that the magnetic flux of the demagnetizing field passing through the permanent magnet M2 is directed toward the front end 73a of the protrusion 73 for holding the permanent magnet, the outer peripheral bridging portion 71 and the inner peripheral bridging portion 72 of the supporting protrusion 73 become blocked at their outer peripheral and inner peripheral ends due to the saturation of the magnetic flux, in other words, they become in a state of high magnetic resistance. Therefore, it is also possible to prevent the magnetic flux of the demagnetizing field passing through the permanent magnet M2 from flowing into the protrusion 73 through the outer peripheral bridging portion 71 and the inner peripheral bridging portion 72. Furthermore, the undesirable situation of the magnetic flux of the demagnetizing field passing through the protrusion 73 and grazing the permanent magnet M2 will not occur, thus preventing irreversible demagnetization in the permanent magnet M2. That is, the anti-demagnetizing performance of the permanent magnet M2 is improved.

[0067] As a countermeasure against irreversible demagnetization, methods include using permanent magnets M1 and M2 with high coercivity, or increasing the thickness of permanent magnets M1 and M2 (the thickness between the magnetic pole surfaces Ma and Mb). However, these methods lead to increased costs and a larger rotary motor 1. In this embodiment, irreversible demagnetization can be avoided without such treatment, thus avoiding the adverse effects of increased costs and a larger rotary motor 1.

[0068] [Regarding voids 91 and 92]

[0069] The rotor core 22 has a gap hole (cavity) 91 at a position close to the outer peripheral surface and on the d-axis for each magnetic pole. The rotor core 22 has a gap hole (cavity) 92 spanning two magnetic poles at a position close to the inner hole 23 and on the q-axis.

[0070] Each void 91 has a roughly isosceles triangular cross-sectional shape formed by three peripheries 91a, 91b, and 91c, and is formed along the entire axial length of the rotor core 24. The periphery 91a, which corresponds to the base of the isosceles triangle among the three peripheries 91a, 91b, and 91c forming each void 91, approaches the outer peripheral surface 22x while being orthogonal to the d-axis. The remaining two peripheries 91b and 91c are inclined relative to the d-axis while gradually moving away from the outer peripheral surface.

[0071] Each void 92 has a polygonal cross-sectional shape formed by seven peripheries 92a to 92g, and is formed along the entire axial length of the rotor core 22. The largest periphery 92a among the peripheries 92a to 92g forming each void 92 is orthogonal to the q-axis and faces the inner hole 23. Two peripheries 92b and 92g, extending outwards from both sides of this periphery 92a, are opposite each other across the d-axis. Two peripheries 92c and 92f, continuous with these peripheries 92b and 92g, extend towards the q-axis. The remaining two peripheries 92d and 92e, continuous with these peripheries 92c and 92f, gradually approach the outer circumferential surface 22x while tilting relative to the d-axis towards the q-axis. Each void 92 is larger than each void 91. These voids 91 and 92 serve as passageways for refrigerant (cooling oil) and also contribute to the weight reduction of the rotor core 22.

[0072] Furthermore, the present invention is not limited to the original embodiments described above. During implementation, the constituent elements can be modified and embodied by variation without departing from its spirit. Moreover, various inventions can be formed through appropriate combinations of the multiple constituent elements disclosed in the above embodiments. For example, several constituent elements may be deleted from all the constituent elements shown in the embodiments. Furthermore, constituent elements from different embodiments may be appropriately combined.

[0073] For example, the number, size, and shape of the rotor are not limited to the above-described embodiments and can be modified according to the design. The number of permanent magnets in each pole of the rotor is not limited to two and can be increased as needed. The first central bridging section constituting the bridging part is not limited to two poles and can also be three or more poles.

Claims

1. A rotor, characterized in that, have: The rotor core has a center of rotation; Multiple permanent magnets are disposed in the rotor core, forming multiple magnetic poles around the center of rotation; The first magnet receiving region and the second magnet receiving region are disposed on each of the magnetic poles of the rotor core. Each of them has an end that is separated from each other in the circumferential direction of the rotor core at a position close to the outer peripheral surface of the rotor core, and another end that is close to each other at a position that is separated from each other in the radial direction of the rotor core from the outer peripheral surface of the rotor core. The first magnet receiving region and the second magnet receiving region receive each of the permanent magnets. The first outer peripheral magnetic gap and the second outer peripheral magnetic gap are disposed on each of the magnetic poles of the rotor core, connected to one end of the first magnet receiving area and the second magnet receiving area respectively, and open to the outside of the rotor core through the outer peripheral surface of the rotor core. The first inner circumferential magnetic gap and the second inner circumferential magnetic gap are disposed on each of the magnetic poles of the rotor core and are connected to the other end of the first magnet receiving area and the second magnet receiving area, respectively. The outer peripheral center magnetic gap and the inner peripheral center magnetic gap are disposed on each of the magnetic poles of the rotor core, and are located on the outer peripheral side and inner peripheral side of the rotor core in the radial direction, separated from each other, by the first inner peripheral magnetic gap and the second inner peripheral magnetic gap. The first and second outer peripheral bridging portions are located between the first inner peripheral magnetic gap and the outer peripheral central magnetic gap, and between the second inner peripheral magnetic gap and the outer peripheral central magnetic gap, respectively, of the magnetic poles of the rotor core. They are configured such that the spacing between them narrows from the outer peripheral side to the inner peripheral side of the rotor core. The first and second outer peripheral bridging portions are connected to a region of the rotor core that is further outward than the first magnet receiving region and the second magnet receiving region, the first outer peripheral magnetic gap and the second outer peripheral magnetic gap, the first inner peripheral magnetic gap and the second inner peripheral magnetic gap, and the outer peripheral central magnetic gap. The first inner circumferential bridging portion and the second inner circumferential bridging portion are respectively located between the first inner circumferential magnetic gap and the inner circumferential central magnetic gap, and between the second inner circumferential magnetic gap and the inner circumferential central magnetic gap, and are configured such that the spacing between them narrows from the outer circumferential side of the rotor core toward the inner circumferential side. The first inner circumferential bridging portion and the second inner circumferential bridging portion are respectively connected to the first outer circumferential bridging portion and the second outer circumferential bridging portion, and are connected to the region in the rotor core that is closer to the inner circumferential side than the first magnet receiving region and the second magnet receiving region, the first outer circumferential magnetic gap and the second outer circumferential magnetic gap, the first inner circumferential magnetic gap and the second inner circumferential magnetic gap, and the inner circumferential central magnetic gap. A central bridging portion is disposed on each of the magnetic poles of the rotor core, located between the outer peripheral central magnetic gap and the inner peripheral central magnetic gap, and is mounted between the connecting portion of the first outer peripheral bridging portion and the first inner peripheral bridging portion and the connecting portion of the second outer peripheral bridging portion and the second inner peripheral bridging portion. A first protrusion for holding a permanent magnet is provided on each of the magnetic poles of the rotor core, protruding from the connection between the first outer peripheral side bridging portion and the first inner peripheral side bridging portion into the first inner peripheral side magnetic gap and facing the first magnet receiving area. as well as A second protrusion for holding the permanent magnet is provided on each of the magnetic poles of the rotor core, protruding from the connection portion of the second outer peripheral side bridging portion and the second inner peripheral side bridging portion into the second inner peripheral side magnetic gap and facing the second magnet receiving area. In the first peripheral bridging portion, the part that forms the boundary with the peripheral central magnetic gap includes a straight section that extends in a straight line. In the first inner circumferential bridging portion, the part that forms the boundary with the inner circumferential central magnetic gap includes a straight-line portion that extends in a straight line. In the second outer peripheral bridging portion, the part that forms the boundary with the outer peripheral central magnetic gap includes a straight section that extends in a straight line. In the second inner circumferential bridging portion, the part that forms the boundary with the inner circumferential central magnetic gap includes a straight section that extends in a straight line. In the central bridging portion, the portion that forms the boundary with the inner peripheral side central magnetic gap includes a straight line portion that extends along a direction orthogonal to an imaginary straight line containing the straight lines of the first outer peripheral side bridging portion, the first inner peripheral side bridging portion, the second outer peripheral side bridging portion, and the second inner peripheral side bridging portion, respectively. The intersection point of the imaginary straight line containing the first outer peripheral bridging portion and the imaginary straight line containing the central bridging portion is located further away from the first magnet receiving area than the intersection point of the imaginary straight line containing the first inner peripheral bridging portion and the imaginary straight line containing the central bridging portion. The intersection of the dummy straight line of the straight portion including the second peripheral side bridging portion and the dummy straight line of the straight portion including the central bridging portion is located further away from the second magnet receiving area than the intersection of the dummy straight line of the straight portion including the second inner peripheral side bridging portion and the dummy straight line of the straight portion including the central bridging portion.

2. The rotor as claimed in claim 1, characterized in that, The minimum width of the first inner circumferential bridging portion of the rotor core in the circumferential direction is the same as or greater than the minimum width of the first outer circumferential bridging portion of the rotor core in the circumferential direction. The minimum width of the second inner circumferential bridging portion of the rotor core in the circumferential direction is the same as or greater than the minimum width of the second outer circumferential bridging portion of the rotor core in the circumferential direction.

3. A rotary electric motor, characterized in that, have: The rotor as claimed in claim 1 or 2; and The stator that rotatably supports the rotor.

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