Rotors for rotating electrical machines

Abstract

The present invention provides a rotor for a rotating electric machine having a caulking portion provided in the radial middle portion of a rotor core while suppressing obstruction of the passage of magnetic flux. Outer circumferential boundary points (PA1, Pa1) are set on the long sides (As, as) of a pair of first magnets (A, a) at positions excluding corner gaps, and a circular arc centered at a vertex (S2) and passing through the outer circumferential boundary points (PA1, Pa1) is set as a first imaginary boundary line (La1). Inner circumferential boundary points (PB1, Pb1) are set on the long sides (Bs, bs) of a pair of second magnets (B, b) at positions excluding corner gaps, and a circular arc centered at a vertex (S2) and passing through the inner circumferential boundary points (PB1, Pb1) is set as a second imaginary boundary line (Lb1). Furthermore, a caulking portion (50) is provided on the q-axis in the region between the first imaginary boundary line (La1) and the second imaginary boundary line (Lb1), in other words, in the radial middle portion of the rotor core.

Description

Technical Field

[0001] The present invention relates to a rotor for a rotating electrical machine, and more particularly to a technology capable of appropriately defining the position of a caulking portion. Background Art

[0002] A rotor for a rotating electric machine is known, comprising a cylindrical rotor core formed of a plurality of laminated steel plates, magnets being arranged on both sides of the rotor core in a circumferential direction so as to sandwich a q-axis, and a caulking portion being provided on the q-axis for positioning the laminated steel plates (see FIG. 8 of Patent Document 1).

[0003] Patent Document 2 proposes a rotor for a rotating electric machine, wherein (a) a plurality of magnets are arranged symmetrically and radially spaced apart about the d-axis passing through the rotational centerline of the rotor core, forming a V-shaped or U-shaped shape that widens toward the outer circumference of the rotor core, thereby forming a single magnetic pole. (b) A plurality of magnetic poles are arranged on the rotor core at equal angular intervals around the rotational centerline. In this case, the midline between two circumferentially adjacent magnetic poles becomes the q-axis, and multiple pairs of magnets are arranged symmetrically and radially spaced apart on either side of the q-axis, with magnetic flux paths formed between the multiple pairs of magnets.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-89291

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-54659 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] However, since the caulking portion is formed by forming a bend in the laminated steel sheets, or by forming a recess or inner edge flange hole through drawing or stretching, the caulking portion may increase magnetic resistance, thereby obstructing the passage of magnetic flux, reducing magnetic flux and lowering motor torque. Alternatively, the caulking portion may increase iron loss caused by eddy currents due to peripheral magnetic flux fluctuations, thereby reducing motor efficiency. In other words, when a pair of magnets are arranged with the q-axis sandwiched between them, and a magnetic flux path is formed between them, it is desirable to arrange the caulking portion so as not to obstruct the magnetic flux path. However, when multiple pairs of magnets are arranged radially apart from the rotor core with the q-axis sandwiched between them, as described in Patent Document 2, the placement of the caulking portion becomes a problem. If the caulking portion is arranged at the outer or inner peripheral edge of the rotor core, which is farther away from the magnets, the possibility of obstructing the passage of magnetic flux is low. However, there are cases where it is desirable to arrange the caulking portion in the radially intermediate portion of the rotor core, depending on conditions such as the positioning performance of the laminated steel sheets.

[0010] The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a caulking portion in the radially intermediate portion of a rotor core while suppressing obstruction of the passage of magnetic flux of a magnet.

[0011] Means for solving problems

[0012] To achieve the aforementioned object, a first invention is characterized in that: (a) in a rotor for a rotating electrical machine having a cylindrical rotor core formed of a plurality of laminated steel plates, magnets are arranged on both sides of the rotor core in the circumferential direction with respect to a q-axis, and caulking portions are provided on the q-axis for positioning the laminated steel plates; (b) in the rotor core, a pair of first magnets and a pair of second magnets are symmetrically provided as the magnets with respect to the q-axis, and the second magnets are arranged so as to be farther away from the first magnets toward the outer circumference of the rotor core; and (c) the pair of first magnets and the pair of second magnets are symmetrically provided with respect to the q-axis. The magnets are arranged so that the cross-sections thereof at right angles to the rotation center line of the rotor core are rectangular and each is arranged in an inverted V-shape that expands as it approaches the inner circumference of the rotor core; (d) an angle (an opening angle of the inverted V-shape) of a vertex S1 of the inverted V-shape formed by extending the long sides of the rectangular cross-sections on the q-axis side of the pair of first magnets is greater than an angle (an opening angle of the inverted V-shape) of a vertex S2 of the inverted V-shape formed by extending the long sides of the rectangular cross-sections on the q-axis side of the pair of second magnets; (e) A first magnetic flux path is formed between the two magnets, and a second magnetic flux path is formed between the two magnets. (f) Furthermore, in the case where a corner gap is provided between the outer circumference of the rotor core and the long side of the rectangular cross-section of the first magnet on the q-axis side, or between the two magnet mounting holes, an outer circumference boundary point of the first magnetic flux path is set at a position on the long side excluding the corner gap from the outer circumference corner, and an arc centered at the vertex S2 and passing through the outer circumference boundary point of the pair of first magnets is set as a first imaginary boundary line. (g) At the corner of the inner circumference of the rotor core on the long side of the q-axis side of the rectangular cross-section of the second magnet, or in the case where a corner gap is provided between the rotor core and the magnet mounting hole, the inner circumference boundary point of the second magnetic flux channel is set on the long side and at a position where the corner gap portion is removed from the inner circumference corner, and the arc centered on the vertex S2 and passing through the inner circumference boundary point of the pair of second magnets is set as the second boundary imaginary line. (h) The caulking portion is provided on the q-axis and in the area between the first boundary imaginary line and the second boundary imaginary line.

[0013] The second invention is characterized in that, in the rotor for a rotating electrical machine of the first invention, (a) a plurality of pairs of magnets are symmetrically and separately arranged in the radial direction of the rotor core with the d-axis passing through the rotation center line of the rotor core as the symmetry axis so as to form a V-shape or a U-shape that expands as it approaches the outer circumference of the rotor core, thereby forming one magnetic pole, (b) a plurality of magnetic poles are arranged in the rotor core at equal angular intervals around the rotation center line, and (c) a midline between two circumferentially adjacent magnetic poles of the plurality of magnetic poles is the q-axis, and of the two pairs of magnets symmetrically and separately located in the radial direction of the rotor core on both sides of the q-axis, the inner pair of magnets is the first magnet, and the outer pair of magnets is the second magnet.

[0014] The third invention is characterized in that, in the rotor for the rotating electrical machine of the second invention, the magnetic pole has a multilayer structure including a first layer in which a total of four or more magnets, including the pair of first magnets and the pair of second magnets, are arranged in the V-shape or U-shape, and a second layer in which a plurality of magnets are arranged in the V-shape or U-shape on the outer peripheral side of the rotor core relative to the first layer.

[0015] A fourth invention is characterized in that, in the rotating electrical machine rotor according to any one of the first to third inventions, the angle of the vertex S1 is three times or more the angle of the vertex S2 .

[0016] Effects of the Invention

[0017] In this rotating electrical machine rotor, outer boundary points of a first magnetic flux path are defined at corners of the outer periphery of the rotor core on the q-axis side of the rectangular cross-section of the pair of first magnets, or at locations excluding corner gaps. A first imaginary boundary line is defined as a circular arc centered on vertex S2 and passing through the outer boundary points. Inner boundary points of a second magnetic flux path are defined at corners of the inner periphery of the rotor core on the q-axis side of the rectangular cross-section of the pair of second magnets, or at locations excluding corner gaps. A second imaginary boundary line is defined as an arc centered on vertex S2 and passing through the inner boundary points. Furthermore, a caulking portion is provided in the region between the first and second imaginary boundary lines on the q-axis, in other words, in the radially intermediate portion of the rotor core.

[0018] On the other hand, the second magnet is arranged in an inverted V-shaped configuration on the outer circumference of the rotor core relative to the first magnet, at an angle smaller than that of the first magnet's vertex S1. A first imaginary boundary line is defined as an arc centered on vertex S2 of the second magnet and passing through the outer circumference boundary of the first magnet. This first imaginary boundary line approximates the outer circumference boundary of the rotor core in the first magnetic flux path. Furthermore, a second imaginary boundary line is defined as an arc centered on vertex S2 and passing through the inner circumference boundary of the second magnet. This second imaginary boundary line approximates the inner circumference boundary of the rotor core in the second magnetic flux path. Therefore, by providing a caulking portion in the region between the first and second imaginary boundary lines, obstruction of the first and second magnetic flux paths is appropriately suppressed, and a decrease in motor torque and efficiency due to the caulking portion is minimized.

[0019] The second invention is preferably applied to the present invention in which a caulking portion is provided in a radially intermediate portion of the rotor core to suppress obstruction of the first and second magnetic flux paths while a plurality of pairs of magnets are symmetrically arranged in a V-shape or U-shape with the d-axis as an axis of symmetry, wherein a plurality of magnetic poles are provided around the rotation center line of the rotor core, the midline between two circumferentially adjacent magnetic poles being the q-axis, and two pairs of magnets located on both sides of the circumferential direction sandwiching the q-axis being the first and second magnets.

[0020] The third invention can appropriately achieve the following effect of the present invention, that is, when the above-mentioned magnetic pole becomes a multi-layer structure, the multi-layer structure has a first layer in which a total of four or more magnets including a pair of first magnets and a pair of second magnets are arranged, and a second layer in which a plurality of magnets are arranged in a V-shape or a U-shape on the outer peripheral side of the rotor core compared to the first layer, by defining the first boundary imaginary line and the second boundary imaginary line based on the vertex S2 and setting the position of the caulking portion in this case as well, it is possible to provide the caulking portion in the radial middle portion of the rotor core while suppressing the situation in which the first magnetic flux path and the second magnetic flux path are obstructed.

[0021] In the fourth invention, when the angle of vertex S1 is three times or more than the angle of vertex S2, the opening angle of the inverted V-shaped shape of the pair of first magnets (the angle of vertex S1) is relatively large, thus posing a challenge in determining the first imaginary boundary line associated with the first magnets. However, by using an arc centered on vertex S2 and passing through the outer peripheral boundary point of the first magnet as the first imaginary boundary line and determining the position of the caulking portion, it is possible to position the caulking portion in the radially intermediate portion of the rotor core while suppressing obstruction of the first magnetic flux path. Specifically, while the arc centered on vertex S1 and passing through the outer peripheral boundary point of the pair of first magnets could be considered as the first imaginary boundary line, in this case, the large angle of vertex S1 would cause the first imaginary boundary line to significantly expand toward the inner circumference of the rotor core, thereby forming the first magnetic flux path also on the outer circumference side of the rotor core relative to the first imaginary boundary line, i.e., on the side where the caulking portion is provided. This could potentially obstruct the passage of magnetic flux due to the caulking portion. Furthermore, although it is conceivable to connect the outer peripheral boundary points of the pair of first magnets with a straight line to form a first imaginary boundary line, this would narrow the area where the caulking portion can be provided, and there is a possibility that the caulking portion cannot be provided appropriately. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic cross-sectional view for explaining a rotating electrical machine including a rotor for a rotating electrical machine according to one embodiment of the present invention.

[0023] Figure 2 1 is a cross-sectional view of the rotor at right angles to the rotation center line O, and is a diagram showing a 1 / 4 portion around the rotation center line O in an enlarged manner.

[0024] Figure 3 To be set in Figure 2 An enlarged cross-sectional view of the caulking portion on the q-axis.

[0025] Figure 4 To further enlarge the Figure 2 Diagram of the rotor portion near the q-axis.

[0026] Figure 5 The figures are used to illustrate other embodiments of the present invention. Figure 4 The corresponding enlarged view of the part near the q-axis. DETAILED DESCRIPTION

[0027] A rotating electrical machine is a rotating electrical machine, sometimes also called a rotating machine. It is a motor or generator, or a motor generator used for both, such as a permanent magnet synchronous motor. Although rare earth magnets are preferably used as magnets, other permanent magnets can also be used. When a magnetic pole is formed by arranging multiple pairs of magnets in a V-shaped or U-shaped manner that expands as it approaches the outer circumference of the rotor core, and multiple magnetic poles are arranged at equal angular intervals around the rotation centerline of the rotor core, the midline between two circumferentially adjacent magnetic poles is the q-axis, and the two pairs of magnets on both sides of the q-axis are the first magnet and the second magnet. The magnet arrangement pattern is appropriately specified so that at least two pairs of magnets are arranged symmetrically with the q-axis sandwiched between them and separated in the radial direction of the rotor core. The magnetic pole preferably has a multilayer structure including a first layer having a total of four or more magnets, including a pair of first magnets and a pair of second magnets, arranged in a V-shape or a U-shape, and a second layer having a plurality of magnets arranged in a V-shape or a U-shape on the outer peripheral side of the rotor core relative to the first layer. However, the magnetic pole may also have a single-layer structure consisting only of the first layer.

[0028] Although the magnets are inserted and fixed in magnet mounting holes, such as those of flux barriers, with gaps (corner gaps) provided at the corners of the magnet mounting holes, for example, between the magnets and the corners, the magnets can also be inserted with virtually no gaps. In the absence of corner gaps, the outer circumference boundary points of the first magnet are defined as the corners of the rotor core on the q-axis long side of the rectangular cross-section, and the inner circumference boundary points of the second magnet are defined as the corners of the rotor core on the q-axis long side of the rectangular cross-section. In the presence of corner gaps, the outer circumference boundary points of the first magnet are defined as the positions on the q-axis long side of the rectangular cross-section, excluding the corner gaps from the outer circumference corners, and the inner circumference boundary points of the second magnet are defined as the positions on the q-axis long side of the rectangular cross-section, excluding the corner gaps from the inner circumference corners. The first magnet and the second magnet are arranged so that, relative to the corner on the outer circumference side of the rotor core on the long side on the q-axis side of the rectangular cross-section of the first magnet, the corner on the inner circumference side of the rotor core on the long side on the q-axis side of the rectangular cross-section of the second magnet is located away from the radial outer circumference side of the rotor core.

[0029] The caulking portion is provided, for example, by forming a recess in the laminated steel sheets through drawing or stretching, by bending the portions with slits on both sides into a V-shape, or by forming inner edge flanged holes. While the caulking portion is provided, for example, in the form of a long strip such as a rectangle or an oblong that is elongated along the q-axis so as not to obstruct the stator magnetic flux passing along the q-axis, a circular or square caulking portion, or a rectangular caulking portion that is elongated at right angles to the q-axis, may also be provided.

[0030] Although the angle of the vertex S1 of the inverted V-shape of the pair of first magnets can be set to, for example, three times or four times the angle of the vertex S2 of the inverted V-shape of the pair of second magnets, as long as at least the angle of the vertex S1 is greater than the angle of the vertex S2, the present invention can be applied even if it is less than three times.

[0031] [Example]

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the drawings are appropriately simplified or deformed for the purpose of explanation, and the dimensional ratios, angles, shapes, etc. of each part are not necessarily accurately depicted.

[0033] Figure 1 1 is a diagram illustrating a rotating electrical machine 10 including a rotating electrical machine rotor 12 (hereinafter simply referred to as a rotor 12 ) as one embodiment of the present invention, and is a schematic cross-sectional view taken along a rotation center line O. FIG. Figure 2 1 is a cross-sectional view of the rotor 12 perpendicular to the rotation centerline O, showing an enlarged 1 / 4 portion (90° angle range). The rotating electric machine 10 is a permanent magnet embedded synchronous motor and an electric generator capable of being used alternatively as a motor or a generator. For example, it is suitable for use as a driving power source for electric vehicles, including hybrid vehicles. The rotating electric machine 10 includes a rotor 12 and a stator 14, which are arranged concentrically with the rotation centerline O. In the description of this embodiment, the rotation centerline O of the rotating electric machine 10 is also used as the centerline of the rotor 12, the stator 14, and the rotor shaft 20. The stator 14 includes a cylindrical stator core 16 disposed on the outer periphery of the rotor 12 and a plurality of stator coils 18 wound around the stator core 16. The stator core 16 is formed by stacking a plurality of annular steel plates 17 perpendicularly to the rotation center line O and in the axial direction, that is, in the direction parallel to the rotation center line O. The stator core 16 is fixed to a housing (not shown) by pressing or fixing bolts.

[0034] The rotor 12 includes a cylindrical rotor core 22 mounted on the outer circumference of the rotor shaft 20 and a plurality of magnets 24 embedded in the rotor core 22. The rotor core 22 is formed by stacking a plurality of annular steel plates 23 perpendicular to the rotation centerline O and in the axial direction, that is, parallel to the rotation centerline O. A pair of end plates 30, 30 are provided at each end of the rotor core 22, securing the rotor core 22 to the rotor shaft 20. The steel plates 23 correspond to the laminated steel plates and are hereinafter referred to as laminated steel plates 23. A flange 32 is provided on the rotor shaft 20, and a nut 34 is screwed into the flange 32. The rotor core 22, composed of the plurality of laminated steel plates 23, is clamped between the flange 32 and the nut 34, securing the rotor core 22 to the rotor shaft 20. The magnets 24 are rare earth magnets and, if necessary, are coated with an insulating film.

[0035] like Figure 2 As shown, four types of flux barriers 40a, 40b, 40c, and 40d (hereinafter referred to as flux barriers 40 unless otherwise specifically distinguished) are provided on the rotor core 22 in an axially penetrating manner, and magnets 24 are inserted into the magnet mounting portions of the flux barriers 40 and fixed in a fixed posture by adhesive or the like. Figure 2 In the figure, the magnets 24 are shown as six types of magnets, A, a, B, b, C, and c. In the following description, the magnets 24 will be referred to as magnets A, a, B, b, C, and c as needed. Magnets A, a, B, b, C, and c each have a rectangular cross-section perpendicular to the rotation centerline O and are rectangular parallelepiped in shape, approximately the same length as the rotor core 22. Two magnets A and B are mounted in flux barrier 40a, two magnets a and b are mounted in flux barrier 40b, magnet C is mounted in flux barrier 40c, and magnet C is mounted in flux barrier 40d. Each flux barrier 40a and 40b has a long strip shape bent midway, with magnets A, B, a, and b fixed to either side of the bent portion. Furthermore, each flux barrier 40 has hollow portions on either side of the magnets 24, which can be used as channels for cooling fluid to cool the magnets 24. The flux barrier 40 corresponds to a magnet mounting hole.

[0036] The four types of flux barriers 40a to 40d are arranged in a V-shaped or U-shaped pattern that expands toward the outer periphery of the rotor core 22, and the six magnets 24 arranged in this V-shaped pattern form a single magnetic pole Mv. Furthermore, in the rotor core 22, a plurality (eight in this embodiment) of magnetic poles Mv are arranged at equal angular intervals around the rotation centerline O. The V-shaped pattern of the magnetic poles Mv is symmetrical about the d-axis passing through the rotation centerline O. That is, the pair of flux barriers 40a and 40b are symmetrical about the d-axis, and the magnets A and B arranged in the flux barrier 40a and the magnets a and b arranged in the flux barrier 40b are symmetrically arranged about the d-axis, so that the overall shape is V-shaped or U-shaped. Furthermore, the flux barriers 40c and 40d are symmetrically shaped about the d-axis. The magnets C in the flux barrier 40c and the magnets c in the flux barrier 40d are arranged symmetrically about the d-axis, forming a V- or U-shape. The magnetic poles Mv of this embodiment have a two-layer structure, comprising a first layer Mv1 in which four magnets A, a, B, and b are arranged in a V- or U-shape, and a second layer Mv2 in which a pair of magnets C and c are arranged in a V- or U-shape on the outer circumference of the rotor core 22 relative to the first layer Mv1. The second layer Mv2 can also be omitted.

[0037] In such a rotor 12, the midline between the boundaries of two circumferentially adjacent magnetic poles Mv forms the q-axis. When used as a rotating electrical machine 10, the magnetic flux (stator flux) of the rotating magnetic field formed by the stator 14 passes through the rotor 12 along this q-axis. In this case, a pair of flux barriers 40a and 40b located on either side closest to the q-axis are symmetrically arranged circumferentially about the q-axis, forming an inverted V-shape that widens toward the inner circumference of the rotor core 22. Furthermore, the rectangular-shaped magnets A and a, and B and b, fixed in the flux barriers 40a and 40b, are positioned so that their long sides form an inverted V-shape and are symmetrically arranged circumferentially about the q-axis. The pair of magnets A and a located on the inner circumference of the rotor core 22 are referred to as first magnets, while the pair of magnets B and b located on the outer circumference are referred to as second magnets. In the following description, they are also referred to as first magnets A and a, and second magnets B and b, as needed. The second magnets B and b are arranged so as to be farther away from the first magnets A and a toward the outer peripheral side in the radial direction of the rotor core 22. Specifically, the first magnets A and a and the second magnets B and b are arranged so as to be farther away from the outer peripheral side than the first magnets A and a in the radial direction of the rotor core 22. Figure 4 、 Figure 5 ) on the outer peripheral side of the rotor core 22 ( Figure 5 For the outer boundary points PA2 and Pa2 in FIG, the long sides Bs and bs of the rectangular cross section of the second magnet B and b on the q-axis side (refer to Figure 4 、 Figure 5 ) on the inner circumference side of the rotor core 22 ( Figure 5 The inner peripheral boundary points PB2 and Pb2 in the rotor core 22 are located on the radial outer peripheral side ( Figure 4 、 Figure 5 A position away from the upper side of the center.

[0038] Figure 2 The solid arrows fs in FIG. 1 are examples of magnetic lines of force of the stator magnetic flux passing along the q-axis. The stator magnetic flux passes inside the flux barriers 40a and 40b disposed on either side of the q-axis. The directions of the magnetic lines of force fs of the stator magnetic flux may be opposite. Furthermore, a cavity 42 is provided on the q-axis, extending axially through the rotor core 22, at a portion of the rotor core 22 that is inner than the flux barriers 40a and 40b. The cavity 42 is used, for example, as a cooling hole through which a cooling fluid flows to cool the magnets 24, particularly the pair of first magnets A and a disposed closest to the innermost portion of the rotor core 22, or as a flux detour hole to restrict the flow of magnetic flux. It may also function as both. The cavity 42 is provided so as to extend symmetrically about the q-axis and has a curved shape that convexly curves toward the outer circumference of the rotor core 22.

[0039] The polarities of the NSs of the first magnets A and a and the second magnets B and b are opposite, so that magnetic flux paths are formed between the facing portions of the first magnets A and a and between the facing portions of the second magnets B and b, respectively. Figure 2The dashed arrows fr1 to fr4 illustrate the magnetic flux lines between the first magnets A and a, and between the second magnets B and b. The region between the magnetic flux lines fr1 and fr2 connecting the long sides As and as of the first magnets A and a, which face each other across the q-axis, represents the passage of the magnetic flux between the first magnets A and a and is the first magnetic flux path α. Furthermore, the region between the magnetic flux lines fr3 and fr4 connecting the long sides Bs and bs of the second magnets B and b, which face each other across the q-axis, represents the passage of the magnetic flux between the second magnets B and b and is the second magnetic flux path β. The directions of the magnetic flux lines fr1 to fr4 in magnetic flux paths α and β may be opposite, and the paths of the magnetic flux lines fr1 to fr4 vary depending on the orientation of the magnets A, a, B, and b, the magnetic flux (magnetic torque), the magnetic permeability of the rotor core 22, and other factors. In addition, although a gap (corner gap) is provided between the magnet mounting portion of the flux barrier 40 and the corner portion of the magnet 24, the corner gap becomes a magnetic resistance, so Figure 2 The magnetic force lines fr1 to fr4 are formed so as to connect the inner positions of the magnet 24 excluding the corner gap portion from the corner portion.

[0040] The rotor core 22 is provided with a caulking portion 50 on the q-axis at a position different from the cavity 42 for positioning the plurality of laminated steel plates 23 . Figure 3 , which is a cross-sectional view illustrating an example of a caulking portion 50, wherein a plurality of laminated steel plates 23 constituting the rotor core 22 are overlapped, a punch is inserted into one of the through holes 52 provided in the laminated steel plates 23 at both ends and pressed, thereby performing a drawing or stretching process to form a recessed portion 54, and the recessed portions 54 are engaged with each other to position the plurality of laminated steel plates 23, thereby positioning the laminated steel plates 23 in a plane perpendicular to the rotation center line O ( Figure 2 The recess 54 may be formed by separating the plurality of laminated steel plates 23 constituting the rotor core 22 by a predetermined number of sheets.

[0041] At the caulking portion 50, there is a possibility that the magnetic resistance increases, thereby hindering the passage of magnetic flux, and then reducing the magnetic flux and reducing the motor torque, or increasing the iron loss caused by overcurrent due to the fluctuation of the surrounding magnetic flux, thereby reducing the motor efficiency. Figure 2As indicated by the solid arrow fs, the stator magnetic flux passing along the q-axis is formed into a rectangular shape that is long along the q-axis so as not to obstruct the stator magnetic flux. The caulking portion 50 also needs to be positioned so as not to obstruct the first magnetic flux path α formed between the first magnets A and a and the second magnetic flux path β formed between the second magnets B and b. However, depending on the positioning performance of the multiple laminated steel plates 23, it may be necessary to position the caulking portion 50 radially midway in the rotor core 22. It is preferable to position the caulking portion 50 on the q-axis between the first magnetic flux path α and the second magnetic flux path β. In this case, the question arises as to how to define the first magnetic flux path α and the second magnetic flux path β, or in other words, how to define the region between the first magnetic flux path α and the second magnetic flux path β. That is, the magnetic lines of force fr1 to fr4 that define the magnetic flux channels α and β are lines conceptually illustrated based on the postures of the first magnets A and a, the second magnets B and b, etc., so in order to set the gap portion 50 in a manner that does not obstruct the magnetic flux channels α and β, it is necessary to specifically define the boundaries of the magnetic flux channels α and β.

[0042] Reference Figure 4 , the position of the above-mentioned caulking portion 50 is specifically described. Figure 4 for, with Figure 2 The figure shows the vicinity of a pair of flux barriers 40a and 40b on both sides of the q-axis in a more enlarged manner. Figure 4 In the figure, vertex S1 is the intersection of the pair of first magnets A on the inner circumference of rotor core 22 and the long sides As and as of the rectangular cross section of magnet a on the q-axis side, respectively. It is also the vertex of the inverted V-shaped shape of the rectangular cross sections of first magnets A and a. Furthermore, vertex S2 is the intersection of the pair of second magnets B on the outer circumference of rotor core 22 and the long sides Bs and b of the rectangular cross section on the q-axis side, respectively. It is also the vertex of the inverted V-shaped shape of the rectangular cross sections of second magnets B and b. Furthermore, the angle of vertex S1 (the inverted V-shaped opening angle) is greater than the angle of vertex S2 (the inverted V-shaped opening angle), and in this embodiment, is at least three times greater. Specifically, the angle of vertex S1 is in the range of 100° to 140°, and is approximately 120° in this embodiment. The angle of vertex S2 is in the range of 20° to 40°, and is approximately 25° in this embodiment. The angle of vertex S1 is at least four times the angle of vertex S2.

[0043] Furthermore, in this embodiment, outer peripheral boundary points PA1 and Pa1 of the first magnetic flux path α are defined on the q-axis long sides As and as of the rectangular cross-section of the first magnets A and a, excluding corner gaps from the corners located on the outer periphery of the rotor core 22. A circular arc centered on the vertex S2 and passing through the outer peripheral boundary points PA1 and Pa1 of the pair of first magnets A and a is defined as the first imaginary boundary line La1, which is the outer peripheral boundary line of the first magnetic flux path α. Furthermore, inner peripheral boundary points PB1 and Pb1 of the second magnetic flux path β are defined on the q-axis long sides Bs and bs of the rectangular cross-section of the second magnets B and b, excluding corner gaps from the corners located on the inner periphery of the rotor core 22. A circular arc centered on the vertex S2 and passing through the inner peripheral boundary points PB1 and Pb1 of the pair of second magnets B and b is defined as the second imaginary boundary line Lb1, which is the inner periphery boundary line of the second magnetic flux path β. The caulking portion 50 is provided on the q-axis and in the region between the first imaginary boundary line La1 and the second imaginary boundary line Lb1. This prevents the caulking portion 50 from obstructing the magnetic flux paths α and β, and also prevents a reduction in the motor torque or motor efficiency caused by the caulking portion 50. The imaginary boundary lines La1 and Lb1 are respectively Figure 2 The magnetic lines fr2 and fr3 are approximate, and by setting the caulking portion 50 in the area between the first boundary imaginary line La1 and the second boundary imaginary line Lb1, the situation where the caulking portion 50 hinders the passage of the magnet magnetic flux between the first magnets A, a and the second magnets B, b is appropriately suppressed.

[0044] Here, the angle of vertex S1 is at least three times the angle of vertex S2, resulting in a relatively large opening angle (the angle of vertex S1) of the inverted V-shaped shape of the pair of first magnets A and a. This poses a challenge in determining the first imaginary boundary line La1 associated with the first magnets A and a. In this embodiment, the position of the caulking portion 50 is defined by an arc centered on vertex S2 and passing through the outer peripheral boundary points PA1 and Pa1 of the first magnets A and a, respectively, as the first imaginary boundary line La1. This allows the caulking portion 50 to be positioned radially intermediate in the rotor core 22 while minimizing obstruction of the first magnetic flux path α. Specifically, while one consideration might be to define the first imaginary boundary line La1 as an arc centered on vertex S1 and passing through the outer peripheral boundary points PA1 and Pa1 of the pair of first magnets A and a, in this case, due to the large angle of vertex S1, the first imaginary boundary line La1 would significantly expand toward the inner circumference of the rotor core 22. Consequently, a first magnetic flux path α would also form on the outer circumference side of the rotor core 22 relative to the first imaginary boundary line La1, i.e., on the side where the caulking portion 50 is provided. Consequently, the passage of magnetic flux might be blocked by the caulking portion 50. Furthermore, while one consideration might be to define the first imaginary boundary line La1 by connecting the outer peripheral boundary points PA1 and Pa1 of the pair of first magnets A and a with a straight line, this would narrow the area where the caulking portion 50 could be provided, potentially preventing the caulking portion 50 from being properly provided.

[0045] In this manner, the rotor 12 of the rotating electrical machine 10 according to this embodiment defines outer boundary points PA1 and Pa1 of the first magnetic flux path α on the q-axis long sides As and as of the rectangular cross-section of the pair of first magnets A and a, excluding corner gaps. A circular arc centered on the vertex S2 and passing through these outer boundary points PA1 and Pa1 serves as a first imaginary boundary line La1. Inner boundary points PB1 and Pb1 of the second magnetic flux path β are defined on the q-axis long sides Bs and bs of the rectangular cross-section of the pair of second magnets B and b, excluding corner gaps, and a circular arc centered on the vertex S2 and passing through these inner boundary points PB1 and Pb1 serves as a second imaginary boundary line Lb1. Furthermore, a caulking portion 50 is provided in the region between the first imaginary boundary line La1 and the second imaginary boundary line Lb1, on the q-axis, in other words, in the radially intermediate portion of the rotor core 22. This arrangement satisfies requirements such as the positioning performance of the laminated steel plates 23.

[0046] On the other hand, the second magnets B, b are arranged on the outer circumference side of the rotor core 22 relative to the first magnets A, a, in an inverted V-shaped configuration with an angle smaller than that of the vertex S1 of the first magnets A, a. A first imaginary boundary line La1 is defined as an arc centered on the vertex S2 of the second magnets B, b and passing through the outer circumferential boundary points PA1, Pa1 of the first magnets A, a. This first imaginary boundary line La1 approximates the outer circumferential boundary line (magnetic field line fr2) of the rotor core 22 in the first magnetic flux path α between the first magnets A, a. Furthermore, a second imaginary boundary line Lb1 is defined as an arc centered on the vertex S2 and passing through the inner circumferential boundary points PB1, Pb1 of the second magnets B, b. This second imaginary boundary line Lb1 approximates the inner circumferential boundary line (magnetic field line fr3) of the rotor core 22 in the second magnetic flux path β between the second magnets B, b. Therefore, by providing the caulking portion 50 in the region between the first imaginary boundary line La1 and the second imaginary boundary line Lb1, the obstruction of the first magnetic flux path α and the second magnetic flux path β is appropriately suppressed, thereby suppressing the reduction in motor torque or motor efficiency caused by the caulking portion 50.

[0047] Furthermore, in the rotor 12 of this embodiment, it is preferable to apply the present invention which realizes the following structure, namely, a plurality of magnetic poles Mv formed by symmetrically arranging a plurality of magnets 24 in a V-shape or U-shape with the d-axis as the axis of symmetry are provided around the rotation center line O of the rotor core, and when the midline between two circumferentially adjacent magnetic poles Mv is the q-axis, and two pairs of magnets 24 located on both sides of the q-axis in the circumferential direction are the first magnets A and a and the second magnets B and b, a caulking portion 50 is provided in the radially intermediate portion of the rotor core 22 while suppressing obstruction of the first magnetic flux path α between the first magnets A and a and the second magnetic flux path β between the second magnets B and b.

[0048] In addition, although the above-mentioned magnetic pole Mv has a two-layer structure, the two-layer structure has a first layer Mv1 in which a pair of first magnets A, a and a pair of second magnets B, b are arranged, totaling four magnets 24, and a second layer Mv2 in which a pair of magnets C, c are arranged in a V-shape or U-shape on the outer peripheral side of the rotor core 22 compared to the first layer Mv1, by defining the first boundary imaginary line La1 and the second boundary imaginary line Lb1 based on the vertex S2 and setting the position of the caulking portion 50, it is possible to appropriately obtain the effect of the present invention of providing the caulking portion 50 in the radial middle portion of the rotor core 22 while suppressing the situation of obstructing the first magnetic flux path α and the second magnetic flux path β.

[0049] In addition, although the angle of the vertex S1 is more than three times the angle of the vertex S2, and the opening angle of the inverted V shape of the pair of first magnets A, a (the angle of the vertex S1) is relatively large, how to set the first boundary imaginary line La1 related to the first magnets A, a becomes a problem. However, by setting the position of the caulking portion 50 as the first boundary imaginary line La1, the arc centered on the vertex S2 and passing through the outer peripheral boundary points PA1, Pa1 of the first magnets A, a is set, the caulking portion 50 can be set in the radial middle part of the rotor core 22 while suppressing the situation of obstructing the first magnetic flux channel α between the first magnets A, a.

[0050] In addition, although in the above embodiment, corner gaps are provided at the magnet mounting portions of the flux barriers 40a and 40b, and the outer peripheral boundary points PA1 and Pa1 of the first magnets A and a and the inner peripheral boundary points PB1 and Pb1 of the second magnets B and b are defined at positions where the corner gaps are removed, in the case of Figure 5 As shown, if the presence of corner gaps at the magnet mounting portions of the flux barriers 40a and 40b can be ignored, the corners of the first magnets A and a can be used as the outer circumferential boundary points PA2 and Pa2, and the corners of the second magnets B and b can be used as the inner circumferential boundary points PB2 and Pb2. Specifically, the outer circumferential corners of the rotor core 22 on the q-axis long sides As and as of the rectangular cross-section of the first magnets A and a are used as the outer circumferential boundary points PA2 and Pa2 of the first magnetic flux path α, and the arc centered at the vertex S2 and passing through the pair of outer circumferential boundary points PA2 and Pa2 is used as the first imaginary boundary line La2, which is the outer circumferential boundary line of the first magnetic flux path α. Furthermore, the inner corners of the rotor core 22 on the q-axis long sides Bs and bs of the rectangular cross-section of the second magnets B and b are defined as the inner boundary points PB2 and Pb2 of the second magnetic flux path β. A circular arc centered on vertex S2 and passing through the pair of inner boundary points PB2 and Pb2 is defined as the second imaginary boundary line Lb2, which serves as the inner imaginary boundary line of the second magnetic flux path β. Furthermore, a caulking portion 60 is provided on the q-axis in the region between the first imaginary boundary line La2 and the second imaginary boundary line Lb2. This achieves substantially the same advantages as those of the aforementioned embodiment, such as providing the caulking portion 60 in the radially intermediate portion of the rotor core 22 while suppressing obstruction of the magnetic flux paths α and β.

[0051] Although the embodiment of the present invention has been described in detail above based on the drawings, this is ultimately just one embodiment, and the present invention can be implemented in various ways with various changes and improvements added based on the knowledge of those skilled in the art.

[0052] Explanation of symbols

[0053] 10: Rotating electric machine; 12: Rotor for rotating electric machine; 22: Rotor core; 23: Laminated steel plates; 24: A, a, B, b, C, c: Magnets; A, a: Magnet (first magnet); B, b: Magnet (second magnet); 40a, 40b, 40c, 40d: Flux barriers (magnet mounting holes); 50, 60: Caulking; O: Rotation centerline; d: d-axis; q: q-axis; Mv: Magnetic pole; Mv1: First layer; Mv2: Second layer; α : first magnetic flux channel; β: second magnetic flux channel; S1: vertex of the inverted V shape of the first magnet; S2: vertex of the inverted V shape of the second magnet; As, as: long sides of the first magnet; Bs, bs: long sides of the second magnet; PA1, Pa1, PA2, Pa2: outer boundary points; PB1, Pb1, PB2, Pb2: inner boundary points; La1, La2: first boundary imaginary line; Lb1, Lb2: second boundary imaginary line.

Claims

1. A rotor for a rotating electric machine, comprising a cylindrical rotor core formed of a plurality of laminated steel plates, wherein magnets are arranged on both sides of the rotor core in the circumferential direction with a q-axis sandwiched therebetween, and a caulking portion is provided on the q-axis for positioning the laminated steel plates, wherein the rotor for a rotating electric machine is characterized in that: In the rotor core, a pair of first magnets and a pair of second magnets are symmetrically provided with respect to the q-axis, and the second magnets are arranged to be farther away from the first magnets toward the outer circumference of the rotor core. The pair of first magnets and the pair of second magnets are each arranged so that a cross section perpendicular to the rotation center line of the rotor core is a rectangular cross section and each has an inverted V-shape that expands toward the inner circumference of the rotor core. The angle of the vertex S1 of the inverted V-shape, which is formed by extending the long sides of the rectangular cross-section on the q-axis side of the pair of first magnets, is greater than the angle of the vertex S2 of the inverted V-shape, which is formed by extending the long sides of the rectangular cross-section on the q-axis side of the pair of second magnets. A first magnetic flux channel is formed between the pair of first magnets, and a second magnetic flux channel is formed between the pair of second magnets. Furthermore, in the following case, At a corner portion of the outer circumference of the rotor core on the long side of the rectangular cross-section of the first magnet on the q-axis side, or when a corner gap is provided between the first magnet and the magnet mounting hole, an outer circumference boundary point of the first magnetic flux path is set at a position on the long side excluding the corner gap portion from the outer circumference corner portion, and an arc centered at the vertex S2 and passing through the outer circumference boundary point of the pair of first magnets is set as a first imaginary boundary line. In the case where a corner gap is provided between the inner circumference corner of the rotor core on the long side of the q-axis side of the rectangular cross-section of the second magnet or the magnet mounting hole, the inner circumference boundary point of the second magnetic flux path is set at a position on the long side and excluding the corner gap portion from the inner circumference corner, and the arc centered at the vertex S2 and passing through the inner circumference boundary point of the pair of second magnets is set as the second imaginary boundary line. The caulking portion is provided on the q-axis in a region between the first imaginary boundary line and the second imaginary boundary line.

2. The rotor for a rotating electrical machine according to claim 1, wherein: A plurality of pairs of magnets are symmetrically arranged and separated in the radial direction of the rotor core so as to form a V-shape or a U-shape that expands toward the outer peripheral side of the rotor core, with the d-axis passing through the rotation center line of the rotor core as the symmetry axis, thereby forming a single magnetic pole. In the rotor core, a plurality of magnetic poles are arranged at equal angular intervals around the rotation center line. The midline of two circumferentially adjacent magnetic poles among the multiple magnetic poles is the q-axis, and of the two pairs of magnets located symmetrically and separately on both sides of the circumferential direction in the radial direction of the rotor core with the q-axis sandwiched therebetween, the pair of magnets on the inner circumference side is the first magnet, and the pair of magnets on the outer circumference side is the second magnet.

3. The rotor for a rotating electrical machine according to claim 2, wherein: The magnetic pole has a multi-layer structure including a first layer in which a total of four or more magnets, including the pair of first magnets and the pair of second magnets, are arranged in the V-shape or U-shape, and a second layer in which a plurality of magnets are arranged in the V-shape or U-shape on the outer peripheral side of the rotor core relative to the first layer.

4. The rotor for a rotating electrical machine according to any one of claims 1 to 3, wherein: The angle of the vertex S1 is at least three times the angle of the vertex S2.

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