Rotor and rotating electric machine

Abstract

According to an embodiment of the present invention, a rotor (100) comprises a rotor shaft (110), a plurality of permanent magnets (130) disposed with line symmetry about an M axis, and a rotor core (120). In the rotor core (120), electromagnetic steel plates are stacked in multiple layers such that the M axis overlaps with the axial direction, with a plurality of magnetic poles (101) arranged uniformly in the circumferential direction. Each magnetic pole (101) has a flux barrier band. The flux barrier band: includes regions where the permanent magnets (130) are housed, nonmagnetic regions, and a bridge; is formed in a substantially convex shape that is convex toward a rotation center axis CL; and connects to an outer circumferential surface. The nonmagnetic regions connect the outer circumferential surface (120x) with the permanent magnets (130). The relationship between two of the nonmagnetic regions, namely first and second flux barriers (122, 126), is such that a circumferential angle Θq1 is greater than a circumferential angle Θq2 when a circumferential angle Θd1 is greater than a circumferential angle Θd2. When viewing a given magnetic pole 101, adjacent magnetic poles have inverted shapes about the M axis of the given magnetic pole.

Description

Rotor and rotating electric machine

[0001] The present invention relates to a rotor and a rotating electric machine.

[0002] A well-known permanent magnet motor is a so-called interior permanent magnet motor, which has a permanent magnet disposed inside an iron core. This interior permanent magnet motor is composed of a stator, which has a substantially cylindrical stator core with multiple stator slots and a stator coil disposed in the stator core, and a permanent magnet rotor, which is disposed radially inside the stator and is rotatable relative to the stator.

[0003] A permanent magnet rotor has a rotor shaft that is rotatable about a central axis of rotation and a rotor core that is fitted and fixed to the rotor shaft. The rotor core has magnet housing holes formed in it, the number of which corresponds to the number of poles. These magnet housing holes house permanent magnets. With this configuration, when current is supplied to the stator coil in a permanent magnet motor, a rotational torque is applied to the rotor due to the interaction between the magnetic flux generated on the primary side (stator side) and the magnetic flux of the permanent magnets in the rotor.

[0004] Japanese Patent No. 3769943 Japanese Patent Application Laid-Open No. 2001-186699 Japanese Patent No. 3938726 Japanese Patent Application Laid-Open No. 2012-29351

[0005] Generally, the presence of stator slots causes magnetic irregularities between the rotor and stator, which in turn causes torque ripple in the rotor, increasing or decreasing the value of the rotational torque, and this causes mechanical vibrations and noise during rotation.

[0006] One known effective means of reducing torque ripple is to skew the electromagnetic steel sheets of the stator or rotor by axially stacking them in such a way that they are offset at equal intervals in the circumferential direction (the direction of rotation). However, this method has the drawback of increasing the number of manufacturing steps and parts required.

[0007] For this reason, several other examples of means for reducing torque ripple are known.

[0008] Fig. 13 is a cross-sectional view showing an example of a pattern of a conventional rotor core 2. Fig. 14 is a schematic layout diagram of laminations showing the configuration of a conventional rotor core.

[0009] In the rotor core 2 pattern shown in Figure 13, each magnetic pole is symmetrical in the circumferential direction. As shown in Figure 14, this method involves stacking laminations 2p with a pattern in which each magnetic pole is symmetrical and laminations 2r, in which the laminations 2p are offset in the circumferential direction, in the axial direction. By stacking the laminations in the axial direction with an offset in the circumferential direction in this way, torque ripple is reduced, that is, a skew effect is obtained. With this type of rotor skew, the magnets embedded in the rotor are skewed, and where different laminations are adjacent, a demagnetizing field concentrates at the ends of the magnets, resulting in the problem of demagnetization of those areas.

[0010] Another known method is to offset torque ripples occurring at each magnetic pole by making the shapes of the permanent magnets and their housing holes asymmetric for each magnetic pole.

[0011] Figure 15 is a partial cross-sectional view of a first pattern portion illustrating a second example of the configuration of a conventional rotor core 2. Figure 15 shows the pattern within one magnetic pole. Two permanent magnets 130 of the same shape are arranged symmetrically with respect to the central axis. A first magnet storage hole 2a and a second magnet storage hole 2b are formed on either side of the central axis. A first flux barrier 2f, which connects the first magnet storage hole 2a to the outer peripheral surface 2x of the rotor core 2, and a second flux barrier 2g, which connects the second magnet storage hole 2b to the outer peripheral surface 2x of the rotor core 2, are different from each other.

[0012] The shape of the inner core portion 2d, which is the radially inner portion of the first magnet storage hole 2a and the second magnet storage hole 2b, is symmetrical with respect to the central axis. On the other hand, the shape of the outer core portion 2c, which is the radially outer portion of the first magnet storage hole 2a and the second magnet storage hole 2b, is asymmetric with respect to the central axis. This method cancels out torque ripple by using a second pattern portion that is the reverse of the first pattern portion.

[0013] However, in the case of a motor that utilizes reluctance torque, there is a problem in that the skew effect is not sufficient.

[0014] There is also a known method of asymmetrically arranging the stator slots, but this method has problems such as a decrease in average torque and insufficient skew effect.

[0015] The problem to be solved by the present invention is to provide a rotor and a rotating electric machine that can ensure the effect of reducing torque ripple without skewing the permanent magnets, even in a rotating electric machine that actively utilizes reluctance torque.

[0016] In order to achieve the above-mentioned object, a rotor according to an embodiment of the present invention comprises a rotor shaft extending in the axial direction of a central axis of rotation; a plurality of permanent magnets extending in the axial direction and arranged in line symmetry with respect to an M-axis extending perpendicularly from the central axis of rotation when viewed in a cross section perpendicular to the central axis of rotation; and magnetic poles attached to the radially outer side of the rotor shaft, including regions in which the permanent magnets are housed, non-magnetic regions, and bridges, and formed in a substantially convex shape toward the central axis of rotation, the magnetic poles having flux barrier bands connecting the outer circumferential surfaces, the magnetic poles being equally spaced in the circumferential direction. and a rotor core having the non-magnetic region connecting the outer circumferential surface and the permanent magnet, wherein a plurality of electromagnetic steel plates arranged in a direction perpendicular to the rotor core are laminated so that the M-axes overlap when viewed in the axial direction, and the magnetic poles are arranged such that an outer core portion is adjacent to the radially outer side of the flux barrier band and an inner core portion is adjacent to the radially inner side of the flux barrier band, and the boundary point between the outer edge of the outer core portion forming the outer circumferential surface of the rotor core and the outer edge facing the non-magnetic region is defined as boundary point P. １１ , the boundary point P ２１ and the boundary point P １１ The boundary point P １２ , the boundary point P ２１ The boundary point P ２２ and the boundary point P １１ The inclination angle Θ is the angle formed by the line connecting the center axis of rotation and the M axis. ｄ１, the boundary point P １２ The inclination angle Θ is the angle formed by the line connecting the center axis of rotation and the M axis. ｑ１ , the boundary point P ２１ The inclination angle Θ is the angle formed by the line connecting the center axis of rotation and the M axis. ｄ２ , the boundary point P ２２ The inclination angle Θ is the angle formed by the line connecting the center axis of rotation and the M axis. ｑ２ When the angle of circumference Θ ｄ１ is the inscribed angle Θ ｄ２ If it is larger, the inscribed angle Θ ｑ１ is the inscribed angle Θ ｑ２ The magnetic pole is larger and is characterized in that, when viewed with respect to a given magnetic pole, the adjacent magnetic pole has a shape that is inverted about the M axis of the given magnetic pole.

[0017] 1 is a longitudinal sectional view showing the configuration of a rotating electric machine according to a first embodiment. FIG. 2 is a first partial cross sectional view showing the configuration of a rotating electric machine according to the first embodiment. FIG. 3 is a partial cross sectional view of a first pattern section explaining features of a rotor according to the first embodiment. FIG. 4 is an explanatory diagram showing changes in the d-axis and q-axis in the first pattern section explaining features of a rotor according to the first embodiment. FIG. 5 is a partial cross sectional view of a second pattern section explaining features of a rotor according to the first embodiment. FIG. 6 is a schematic layout diagram of laminations showing the configuration of a rotor core according to the first embodiment. FIG. 7 is a perspective view showing the entire configuration of a rotor core according to the first embodiment. FIG. 8 is a schematic layout diagram of a first modified example of laminations showing the configuration of a rotor core according to the first embodiment. FIG. 9 is a schematic layout diagram of a second modified example of laminations showing the configuration of a rotor core according to the first embodiment. FIG. 10 is a partial cross sectional view showing a part of a first pattern section explaining features of a rotor according to the second embodiment. FIG. 11 is a partial cross sectional view showing the configuration of a rotating electric machine according to a third embodiment. FIG. 12 is a partial cross sectional view showing a part of a stator explaining features of a rotating electric machine according to the third embodiment. FIG. 13 is a cross sectional view showing an example of a pattern of a conventional rotor core. FIG. 14 is a schematic layout diagram of laminations showing the configuration of a conventional rotor core. FIG. 10 is a partial cross-sectional view of a first pattern portion illustrating a second example of a configuration of a conventional rotor core.

[0018] Hereinafter, a rotor and a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0019] First Embodiment FIG. 1 is a vertical cross-sectional view showing the configuration of a rotating electrical machine 1 according to a first embodiment.

[0020] The rotating electric machine 1 has a rotor 100 , a stator 10 , a bearing 20 , a bearing bracket 30 , and a frame 40 .

[0021] The rotor 100 has a rotor shaft 110 extending in a direction (axial direction) parallel to the central axis of rotation CL, a rotor core 120 attached to the radially outer side of the rotor shaft 110, and a plurality of permanent magnets 130 housed inside the rotor core 120. The rotor core 120 is formed by laminating electromagnetic steel sheets.

[0022] The stator 10 has a stator core 11 disposed radially outside the rotor core 120 so as to surround the rotor core 120 with a gap therebetween, and a stator winding 15 wound around the stator core 11 .

[0023] The bearings 20 are arranged on both outer sides of the rotor core 120 in the axial direction of the rotor shaft 110, and rotatably support the rotor shaft 110. The bearing brackets 30 stationarily support each bearing 20. The frame 40 is cylindrical, and both ends thereof are connected to each bearing bracket 30, and support each bearing bracket 30.

[0024] Fig. 2 is a first partial cross-sectional view showing the configuration of the rotating electric machine 1 according to the first embodiment. Fig. 3 is a partial cross-sectional view of a first pattern portion A illustrating the characteristics of the rotor 100 according to the first embodiment. Both views show cross sections perpendicular to the central axis of rotation CL.

[0025] <Regarding the Stator 10> As shown in Fig. 2, a plurality of stator slots 13 are formed at intervals in the circumferential direction on the inner periphery of the cylindrical stator core 11 of the stator 10. Two adjacent stator slots 13 form a stator tooth 12. A straight portion of a stator winding 15 is housed in each stator slot 13. A slot opening 14, which is a non-magnetic region and communicates with the inner periphery 11x of the stator core 11, is formed radially inside each stator slot 13 to prevent short-circuiting of the magnetic flux generated by the stator winding 15. In a cross section perpendicular to the central axis of rotation CL, the circumferential center line (not shown) of each slot opening 14 is located at the same position as, i.e., coincides with, the circumferential center line (not shown) of the stator slot 13.

[0026] <Regarding the rotor 100> Figure 3 shows the region of one magnetic pole 101. That is, the rotor 100 has multiple regions with a circumferential angle Φ, which are mechanical circumferential angle regions divided equally in the circumferential direction. Hereinafter, these regions will be referred to as magnetic poles 101. Hereinafter, both sides of the magnetic pole in the circumferential direction will be referred to as R axes. Furthermore, the geometric center line that is the circumferential center of the two R axes will be referred to as M axis. In other words, the M axis is the reference line about which the two permanent magnets 130 are line-symmetrical, and the R axis is an axis that is geometrically set midway between the adjacent M axes.

[0027] Fig. 3 shows the case where the rotor core 120 portion of the magnetic pole 101 has the cross-sectional shape of the first pattern portion A. Fig. 2 shows the content of Fig. 3 plus the portion of the stator 10 outside this. The cross-sectional shape shown in Fig. 3 is formed in each electromagnetic steel plate that makes up the rotor core 120. The same applies to each of the following patterns.

[0028] As described above, in each magnetic pole 101, two permanent magnets 130 are arranged symmetrically with respect to the M axis. The cross-sectional shapes and dimensions of the permanent magnets 130 are identical to each other. Here, "identical" means that they match within the range of manufacturing tolerances in terms of design.

[0029] As shown in FIG. 2, the rotor has a first magnet storage hole 121 and a second magnet storage hole 125 formed to store two permanent magnets 130 on both sides in the circumferential direction sandwiching the M axis.

[0030] The first magnet storage hole 121 has a first radially inner portion 123 extending in the direction of the M-axis. Here, the first magnet storage hole 121 is formed so as to penetrate the rotor core 120. Also, a first flux barrier 122 is formed to connect the first magnet storage hole 121 to the outside (external space) of the outer peripheral surface 120x of the rotor core 120. The first flux barrier 122 is a non-magnetic region that replaces the top bridge.

[0031] The second magnet storage hole 125 has a second radially inner portion 127 extending in the direction of the M-axis. Here, the second magnet storage hole 125 is formed so as to penetrate the rotor core 120. Also, a second flux barrier 126 is formed to connect the second magnet storage hole 125 to the outside (external space) of the outer peripheral surface 120x of the rotor core 120. The second flux barrier 126 is a non-magnetic region that replaces the top bridge.

[0032] A central flux barrier 120c is formed between the first magnet storage hole 121 and the second magnet storage hole 125, more specifically, between the first radially inner portion 123 and the second radially inner portion 127, so as to straddle the M-axis. The first radially inner portion 123 and the central flux barrier 120c, which are circumferentially adjacent to each other, form a first bridge 124 extending in the radial direction. Furthermore, the second radially inner portion 127 and the central flux barrier 120c, which are circumferentially adjacent to each other, form a second bridge 128 extending in the radial direction.

[0033] As described above, the rotor core 120 is formed with non-magnetic regions, such as the first magnet hole 121, the first flux barrier 122, the second magnet hole 125, the second flux barrier 126, and the central flux barrier 120c, as well as a flux barrier band including the first bridge 124 and the second bridge 128. The flux barrier band is formed in a generally convex shape toward the rotation center axis CL, extending between two locations on the outer circumferential surface 120x. The flux barrier band 120 is connected to the outside (external space) of the outer circumferential surface 120x via the first flux barrier 126, which is a non-magnetic region. That is, the non-magnetic region of the flux barrier band 120 extends from the permanent magnet 130 shown on the right side of FIG. 3 to the outer circumferential surface 120x. The non-magnetic region of the flux barrier band 120 is connected to the outside (external space) of the outer circumferential surface 120x via the second flux barrier 126, which is a non-magnetic region. That is, the area from the permanent magnet 130 shown on the left side in FIG. 3 to the outer circumferential surface 120x is a non-magnetic area.

[0034] As a result, as shown in Figure 3, magnetic pole 101 is divided into outer core portion 120a, which is located radially outside first magnet storage hole 121 and second magnet storage hole 125, and inner core portion 120b, which is located radially inside first magnet storage hole 121 and second magnet storage hole 125. Outer core portion 120a and inner core portion 120b are connected by first bridge 124 and second bridge 128. The centrifugal force applied to outer core portion 120a when rotor 100 rotates becomes a tensile force of first bridge 124 and second bridge 128, is borne by first bridge 124 and second bridge 128, and is transmitted to inner core portion 120b.

[0035] 3, the distance between the first bridge 124 and the M axis is x1, the distance between the second bridge 128 and the M axis is x2, the circumferential width of the first bridge 124 is w1, and the circumferential width of the second bridge 128 is w2. In this embodiment, x1 = x2 and w1 = w2 hold true.

[0036] In this embodiment, the central flux barrier 120c is formed across the M axis, and as a result, the first bridge 124 and the second bridge 128 are formed. However, this is not limited to this. For example, there may be no central flux barrier 120c, and a single bridge may be formed on or near the M axis by the first radially inner portion 123 and the second radially inner portion 127.

[0037] Next, the relationship between the first flux barrier 122 and the second flux barrier 126, which is a characteristic feature of this embodiment, will be described with reference to FIGS.

[0038] The first flux barrier 122, which connects the first magnet storage hole 121 to the outer surface 120x of the rotor core 120, has a first flux barrier outer boundary 122a, which is the boundary between the portion of the outer edge of the outer core portion 120a of the rotor core 120 that faces the first flux barrier 122, and a first flux barrier inner boundary 122b, which is the boundary between the portion of the outer edge of the inner core portion 120b that faces the first flux barrier 122.

[0039] In addition, the second flux barrier 126, which connects the second magnet storage hole 125 to the outer surface 120x of the rotor core 120, has a second flux barrier outer boundary 126a, which is the boundary between the part of the outer edge of the outer core portion 120a of the rotor core 120 that faces the second flux barrier 122, and a second flux barrier inner boundary 126b, which is the boundary between the part of the outer edge of the inner core portion 120b that faces the second flux barrier 122.

[0040] In the following, unless otherwise specified, when describing a plane (cross section), it means a cross section perpendicular to the central axis of rotation CL. In the cross section perpendicular to the central axis of rotation CL shown in FIG. 3, the boundary point farther from the M axis among the boundary points forming the outer edge forming the outer peripheral surface 120x of outer core portion 120a and the outer edge facing the non-magnetic region (first flux barrier 122) is referred to as boundary point P １１ , a boundary point P between the outer edge forming the outer peripheral surface 120x of the inner core portion 120b and the outer edge facing the non-magnetic region (first flux barrier 122) １１The boundary point P １２ Furthermore, the boundary point between the outer edge forming outer peripheral surface 120x of outer core portion 120a and the outer edge facing non-magnetic region (second flux barrier 126) that is closer to the M axis is defined as boundary point P ２１ , a boundary point P between the outer edge forming the outer peripheral surface of the inner core portion 120b and the outer edge facing the non-magnetic region (second flux barrier 126) ２１ The boundary point P ２２ In addition, the intersection point P １１ The inscribed angle formed by the line connecting the center axis of rotation CL and the M axis is called the inscribed angle Θ ｄ１ , intersection P １２ The inscribed angle formed by the line connecting the center axis of rotation CL and the M axis is called the inscribed angle Θ ｑ１ , intersection P ２１ The inscribed angle formed by the line connecting the center axis of rotation CL and the M axis is called the inscribed angle Θ ｄ２ , intersection P ２２ The inscribed angle formed by the line connecting the center axis of rotation CL and the M axis is called the inscribed angle Θ ｑ２ The relationship between the first flux barrier 122 and the second flux barrier 126 is expressed by the circumferential angle Θ ｄ１ is the inscribed angle Θ ｄ２ If it is larger, the inscribed angle Θ ｑ１ is the inscribed angle Θ ｑ２ Greater than.

[0041] As a result, in this embodiment, there is a portion in magnetic pole 101 that is asymmetric with respect to the M axis. That is, while first magnet storage hole 121 and second magnet storage hole 125 have a relationship in which they have a portion that is line-symmetric with respect to the M axis, they also have an asymmetric portion, i.e., a portion that is not line-symmetric.

[0042] That is, the first magnet storage hole 121 and the second magnet storage hole 125 are each symmetrical to each other with respect to the M axis in a cross section perpendicular to the rotation center axis CL, except for the connection portion with the first flux barrier 122 and the connection portion with the second flux barrier 126.

[0043] On the other hand, the first flux barrier 122 and the second flux barrier 126 are asymmetric with respect to the M axis in a cross section perpendicular to the rotation center axis CL.

[0044] Here, the first point of asymmetry is the angle of the circumference Θ as described above. ｄ１ is the inscribed angle Θ ｄ２ Larger and inscribed angle Θ ｑ１ is the inscribed angle Θ ｑ２ That is, in the outer core portion 120a, the angular position from the M-axis of the first flux barrier outer boundary 122a of the first flux barrier 122 is larger than the angular position from the M-axis of the second flux barrier outer boundary 126a of the second flux barrier 125, i.e., it is further away from the M-axis. Also, in the inner core portion 120b, the angular position from the M-axis of the first flux barrier inner boundary 122b of the first flux barrier 122 is larger than the angular position from the M-axis of the second flux barrier inner boundary 126b of the second flux barrier 125, i.e., it is further away from the M-axis.

[0045] Here, the second point of asymmetry is that the corresponding portions of the first flux barrier outer boundary 122a of the first flux barrier 122 and the second flux barrier outer boundary 126a of the second flux barrier 126 have different shapes, and the corresponding portions of the first flux barrier inner boundary 122b of the first flux barrier 122 and the second flux barrier inner boundary 126b of the second flux barrier 126 have different shapes. Note that the first flux barrier outer boundary 122a and the second flux barrier outer boundary 126a may have different shapes, or the first flux barrier inner boundary 122b and the second flux barrier inner boundary 126b may have different shapes.

[0046] 4 is an explanatory diagram illustrating the changes in the d-axis and q-axis in the first pattern portion A, explaining the characteristics of the rotor 100 according to the first embodiment. In FIG. 4, the M-axis and two R-axes are geometric axes related to the magnetic poles 101. If the rotor core 120 is also completely symmetrical about the M-axis, similar to the permanent magnets 130, then the d-axis, which is the center of the electromagnetic magnetic poles, and the q-axis between the magnetic poles will coincide with the M-axis and R-axis, respectively. FIG. 4 shows that these become misaligned due to the cause of the asymmetry described above in the first point.

[0047] First, the d-axis will be described. In outer core portion 120a, first flux barrier outer boundary 122a of first flux barrier 122 is farther from the M-axis than second flux barrier outer boundary 126a of second flux barrier 126. This causes the distribution of magnetic flux generated by permanent magnet 130 exiting to the outer periphery of rotor core 120 to shift in the circumferential direction, causing the position of the d-axis to shift from the M-axis position toward first flux barrier 122. The resulting d-axis position is shown as the da-axis.

[0048] Next, the q-axis will be described. In inner core portion 120b, first flux barrier inner boundary 122b of first flux barrier 122 is farther from the M-axis than second flux barrier inner boundary 126b of second flux barrier 126, so the reluctance becomes asymmetric and the position of the q-axis shifts from the M-axis position toward first flux barrier 122. The resulting position of the q-axis is shown as qa-axis.

[0049] <Regarding the Second Pattern Section B> FIG. 5 is a partial cross-sectional view of the second pattern section B illustrating features of the rotor 100 according to the first embodiment. FIG. 5 is a view from the same direction as FIGS. 2 to 4 . FIG. 5 is a view in which FIG. 3 is inverted left and right with respect to the M axis. To avoid confusion, the symbols are also inverted left and right. That is, the first pattern section A and the second pattern section B are rotationally symmetrical with respect to the M axis. Specifically, the left side of the M axis of the first pattern section A is symmetrical with the right side of the M axis of the second pattern section B, and the right side of the M axis of the first pattern section A is symmetrical with the left side of the M axis of the second pattern section B. In other words, they are in a left-right inverted relationship. That is, the cross-sectional shape of the pattern section B can be said to be an inverted cross-sectional shape obtained by inverting both sides of the cross-sectional shape of the pattern section A with respect to the M axis. Alternatively, in practice, this corresponds to the case where the electromagnetic steel sheet of the first pattern section A is used upside down as the electromagnetic steel sheet of the second pattern section B. In other words, the first pattern portion A and the second pattern portion B can be said to be reversed.

[0050] 5, the portions symmetrical to the first pattern portion A with respect to the M axis substantially, i.e., in terms of shape and size, except for the difference in symbols, overlap with the first pattern portion A. Therefore, in the second pattern portion B, the portions that substantially differ from the first pattern portion A, except for the symbols, are the first flux barrier 122 and the second flux barrier 126.

[0051] <Explanation of laminations of rotor core 120> Fig. 6 is a schematic layout diagram of laminations showing the configuration of the rotor core 120 according to the first embodiment. Fig. 7 is a perspective view showing the overall configuration of the rotor core 120 according to the first embodiment.

[0052] The rotor core 120 has a first laminated portion 120p and a second laminated portion 120q that is connected in series to the first laminated portion 120p in the axial direction. The first laminated portion 120p and the second laminated portion 120q are each formed by laminating common electromagnetic steel sheets.

[0053] The first laminated portion 120p is made up of a plurality of first pattern portions A arranged in the circumferential direction. The second laminated portion 120q is made up of a plurality of second pattern portions B arranged in the circumferential direction. Note that, although FIG. 6 shows an example in which the magnetic poles 101 have eight poles, this is not limiting and the number of poles may be four or more. The same applies hereinafter.

[0054] The first laminated portion 120p and the second laminated portion 120q are arranged so that their M axes are aligned on the same line. As a result, symmetrical portions of the first pattern portion A and the second pattern portion B overlap in the axial direction. For example, as shown in FIG. 2, the first magnet storage hole 121 and the second magnet storage hole 125 of the first pattern portion A overlap in the axial direction with the second magnet storage hole 125 and the first magnet storage hole 121 of the second pattern portion B. As a result, the permanent magnet 130 can extend axially through and penetrate the first laminated portion 120p and the second laminated portion 120q. This forms the first laminated configuration state of the rotor core 120.

[0055] <Operation> In this embodiment having the above configuration, the asymmetrical portion between the rotor core 120 in the first lamination portion 120p and the rotor core 120 in the second lamination portion 120q cancels out the torque ripple due to the phase difference between the torque ripple in one lamination portion and the torque ripple in the other lamination portion, thereby providing an excellent skew effect. In a rotating electric machine that uses both magnet torque and reluctance torque, in the conventional configuration of FIG. 15, only the d-axis in each lamination portion is misaligned, resulting in a phase difference only in the torque ripple caused by the magnet torque, and the skew effect is insufficient. In contrast, in this embodiment, both the d-axis and q-axis in each lamination portion can be misaligned, thereby generating a phase difference in both the magnet torque and the reluctance torque, thereby providing an excellent skew effect. Furthermore, because the magnets can be aligned axially without skew, unintended demagnetization of the magnets can be prevented.

[0056] 8 is a schematic layout diagram of a first modified example of laminations showing the configuration of the rotor core 120 according to the first embodiment. The rotor core 120 has a third laminated portion 120r.

[0057] In the third laminated portion 120r, the first pattern portion A and the second pattern portion B are alternately arranged in the circumferential direction, thereby forming a second laminated configuration state of the rotor core 120. By mixing asymmetric portions in the same plane in this way, a phase difference in the torque ripple occurs between the pattern portion A and the pattern portion B, as in the embodiment, and an excellent skew effect can be achieved.

[0058] 9 is a schematic layout diagram of a second modified example of laminations illustrating the configuration of the rotor core 120 according to the first embodiment. The rotor core 120 has a third laminated portion 120r similar to that of the first modified example, and a fourth laminated portion 120s connected in series in the axial direction to the third laminated portion 120r.

[0059] The fourth laminated portion 120s is obtained by shifting the third laminated portion 120r in the circumferential direction by a circumferential angle Φ (FIG. 3), which is the mechanical angle of one magnetic pole 101, in a clockwise or counterclockwise direction. It can also be considered a combination of the configurations in FIGS. 6 and 8. This forms the third laminated configuration state of the rotor core 120.

[0060] In this way, by mixing asymmetrical portions in the same plane and in the axial direction, a phase difference in torque ripple occurs between pattern portion A and pattern portion B, as in the embodiment, and an excellent skew effect can be achieved. Furthermore, in the configuration of FIG. 8 , by alternately arranging different pattern portions in the circumferential direction, a low-order circular mode (in this example, circular fourth order) electromagnetic force is generated secondarily, which is not generated in a configuration in which the same shape is repeated in the circumferential direction. This can cause increased mechanical vibration and noise during rotation. Meanwhile, in the configuration shown in FIG. 9 , the above-mentioned low-order circular mode electromagnetic force is generated in each lamination, but as a whole, when the laminations are integrated, it is generated in an anti-phase relationship between the third lamination portion 120r and the fourth lamination portion 120s. Therefore, the integration of the third lamination portion 120r and the fourth lamination portion 120s cancels out the low-order circular mode electromagnetic force, thereby solving the above-mentioned problem.

[0061] <Effects> In the present embodiment and its modified examples configured as described above, by combining rotor cores 120 so that the directions of asymmetry are opposite to each other, it is possible to improve the skew effect.

[0062] Second Embodiment FIG. 10 is a partial cross-sectional view showing a part of a first pattern portion A1 for explaining the features of a rotor 100a according to a second embodiment.

[0063] In the first pattern portion A1, the first and second points at which the magnetic pole 101 described in the first embodiment is asymmetric with respect to the M axis are the same as those in the first pattern portion A of the first embodiment.

[0064] In this embodiment, the magnetic pole 101 further has third and fourth points that are asymmetric with respect to the M axis.

[0065] Third, the distance x between the end face of the first bridge 124 on the M-axis side and the M-axis １ The distance x between the end face of the second bridge 128 on the M-axis side and the M-axis ２ It is designed to be larger.

[0066] As a fourth point, the circumferential width w of the first bridge 124 １ is the circumferential width w of the second bridge 128 ２ It is designed to be larger.

[0067] Due to the first characteristic that magnetic poles 101 are asymmetric with respect to the M axis, the cross-sectional area of ​​outer core portion 120a is larger in the region on the first flux barrier 122 side from the M axis than in the region on the second flux barrier 126 side from the M axis. Therefore, when the centrifugal force applied to outer core portion 120a is borne by first bridge 124 and second bridge 128, the burden on first bridge 124 is greater than the burden on second bridge 128. Furthermore, when the rotation speed is changed, a moment is applied to first bridge 124 and second bridge 128, and similarly, the burden on the first bridge 124 side is greater.

[0068] The third feature of this embodiment improves the moment bearing capacity of the first bridge 124, which has the effect of properly distributing the burden of the moment applied when the rotation speed is changed.

[0069] The fourth feature of this embodiment improves the tensile force bearing capacity of the first bridge 124, thereby achieving an appropriate distribution of the centrifugal force burden applied to the outer core portion 120a.

[0070] As described above, the above-described configuration of this embodiment can further ensure the structural integrity of the rotor core 120.

[0071] [Third embodiment] Fig. 11 is a partial cross-sectional view showing the configuration of a rotating electric machine 1 according to a third embodiment. Fig. 12 is a partial cross-sectional view showing a part of a stator 10a illustrating the characteristics of a rotating electric machine 1a according to the third embodiment. Fig. 12 shows part A in Fig. 11.

[0072] The rotor 100 in this embodiment is similar to that in the first embodiment, and therefore a description thereof will be omitted. The relationship between the rotor 100 and the stator 10a will be described later. As in the first embodiment, the stator 10a in this embodiment has a plurality of stator slots 13 and slot openings 14 formed so as to communicate with the inner peripheral surface 11x of the stator core.

[0073] Here, in a cross section perpendicular to the rotation center axis CL, the center line CL of each slot opening 14, i.e., the non-magnetic region in the circumferential direction, Ｏ is the center line CL of the stator slot 13 in the circumferential direction. Ｓ The slot openings 14 are offset from the slot opening wall 14b. The direction and width of this offset are the same for all slot openings 14. Note that when the slot opening wall 14b is offset toward the slot opening wall 14b, the slot opening wall 14b may be offset to the position of the extension of the slot wall 13b shown by the dashed line, or even beyond that. The gas present in the gap between the rotor core 120 and the stator 10 rotates in the circumferential direction as the rotor 100 rotates. At this time, the inflow of the gas into the slot openings 14 and the turbulence of the flow due to the presence of the slot openings 14 cause an increase in windage loss of the rotating electric machine 1. The greater the offset of the slot openings 14, the greater the flow resistance of the gas flowing into the slot opening, and therefore the lower the windage loss.

[0074] The stator 10a according to this embodiment is combined with the rotor 100 having the lamination pattern shown in FIG. 6 in the first embodiment. This lamination pattern may also be combined with the second embodiment. In this case, when applied to the first pattern portion A, as shown in FIG. 11, the slot opening 14 is positioned on the side opposite to the first flux barrier 122 side, i.e., the second flux barrier 126 side, or the boundary point P ２１ It shall be shifted to the side.

[0075] It should be noted that this should not be combined with the rotor 100 according to the modified example shown in Figures 8 and 9. This is because if the first pattern portion A and the second pattern portion B are mixed in the circumferential direction, the relationship between the stator 10a side and the rotor 100 may be established with the first pattern portion A but not with the second pattern portion B.

[0076] With the configuration of this embodiment as described above, the asymmetry of the rotor 100 and the asymmetry of the stator 10a can be combined so that their directions are opposite. As a result, the amount of deformation due to the asymmetry is shared between the rotor and the stator, and magnetic saturation that occurs in the asymmetric opening is alleviated, thereby improving the skew effect and the average torque. Furthermore, by alleviating the amount of asymmetry of the rotor, a decrease in mechanical strength is suppressed, and by making the bridges within the poles asymmetric, a decrease in strength due to the asymmetric shape of the rotor outer periphery can be suppressed.

[0077] Note that if the rotor flux barrier and the stator flux barrier that are combined in the same cross section are misaligned in the same direction, the desired skew effect will not be achieved. This is because the phase of the torque ripple in a cross section changes depending on the relative positional relationship between the rotor flux barrier and the stator flux barrier that are combined in the same cross section. A cancellation effect can be achieved by sufficiently increasing the phase difference and making it the opposite phase to the torque ripple in the other cross section. Therefore, if the rotor flux barrier and the stator flux barrier that can be combined in the same cross section are misaligned in the same direction, it will hinder the change in the relative positional relationship, preventing the phase of the torque ripple from changing and preventing the intended skew effect from being achieved.

[0078] According to the embodiments described above, it is possible to provide a rotor and a rotating electric machine that can ensure the effect of reducing torque ripple without skewing the permanent magnets, even in a rotating electric machine that actively utilizes reluctance torque.

[0079] [Other Embodiments] Although the embodiments of the present invention have been described above, they are presented as examples and are not intended to limit the scope of the invention. Furthermore, features of each embodiment may be combined. Furthermore, the embodiments may be implemented in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. The embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0080] REFERENCE SIGNS LIST 1, 1a... rotating electric machine, 2... rotor, 2a... first magnet storage hole, 2b... second magnet storage hole, 2c... outer core portion, 2d... inner core portion, 2f... first flux barrier, 2g... second flux barrier, 2p, 2r... laminated portion, 2x... outer peripheral surface, 10, 10a... stator, 11... stator core, 11x... inner peripheral surface, 12... stator teeth, 13... stator slot, 13a, 13b... slot wall, 14... slot opening, 14a, 14b... flux barrier wall, 15... stator winding, 20... bearing, 30... bearing bracket, 40... frame, 100, 100a... rotor, 101... magnetic pole, 110... rotor shaft, 120... rotor core, 120a... outer core portion, 120b... inner core portion, 120c... central flush flux barrier, 120p...first laminated portion, 120q...second laminated portion, 120r...third laminated portion, 120s...fourth laminated portion, 120x...outer circumscribing surface, 120z...circumscribing circle, 121...first magnet storage hole, 122...first flux barrier, 122a...first flux barrier outer boundary, 122b...first flux barrier inner boundary, 123...first magnet storage hole inner portion, 124...first bridge, 125...second magnet storage hole, 126...second flux barrier, 126a...second flux barrier outer boundary, 126b...second flux barrier inner boundary, 127...second magnet storage hole inner portion, 128...second bridge, 130...permanent magnet, A, A1...first pattern portion, B...second pattern portion

Claims

1. A rotor shaft extending in the axial direction of a central axis of rotation; a plurality of permanent magnets extending in the axial direction and arranged in line symmetry with respect to an M-axis extending perpendicularly from the central axis of rotation when viewed in a cross section perpendicular to the central axis of rotation; and a rotor core having a non-magnetic region connecting the outer peripheral surface and a plurality of electromagnetic steel plates attached to the radially outer side of the rotor shaft, the magnetic poles being arranged equally in the circumferential direction and including an area in which the permanent magnets are housed, a non-magnetic region and a bridge, the magnetic poles being formed in a substantially convex shape toward the central axis of rotation and connecting the outer peripheral surface, the magnetic steel plates being laminated in a plurality of layers so that the M-axis overlaps when viewed in the axial direction, the rotor core having a non-magnetic region connecting the outer peripheral surface and the permanent magnets, the magnetic poles being arranged in a manner such that an outer core portion is adjacent to the radially outer side of the flux barrier band and an inner core portion is adjacent to the radially inner side of the flux barrier band, and the boundary point between the outer edge of the outer core portion forming the outer peripheral surface of the rotor core and the outer edge facing the non-magnetic region is defined as boundary point P. １１ , the boundary point P ２１ and among the boundary points between the outer edge forming the outer circumferential surface of the rotor core of the inner core portion and the outer edge facing the non-magnetic region, the boundary point P １１ The closest point is the boundary point P １２ , the boundary point P ２１ The closest point is the boundary point P ２２ and the boundary point P １１ The inclination angle between the line connecting the center axis of rotation and the M axis is called the inclination angle Θ ｄ１ , the boundary point P １２ The inclination angle between the line connecting the center axis of rotation and the M axis is called the inclination angle Θ ｑ１ , the boundary point P ２１ The inclination angle between the line connecting the center axis of rotation and the M axis is called the inclination angle Θ ｄ２ , the boundary point P ２２ The inclination angle between the line connecting the center axis of rotation and the M axis is called the inclination angle Θ ｑ２ When the circumferential angle Θ ｄ１ is the circumference angle Θ ｄ２ If it is larger, the circumference angle Θ ｑ１ is the circumference angle Θ ｑ２ and when viewed with respect to a given magnetic pole, adjacent magnetic poles have shapes that are inverted about the M axis of the given magnetic pole.

2. A rotor as described in claim 1, characterized in that a first bridge and a second bridge are formed on either side of the M axis in the flux barrier band, and at least one of the following is true: the distance between the first bridge and the M axis is greater than the distance between the second bridge and the M axis, or the width of the first bridge is greater than the width of the second bridge.

3. The boundary point P １１ The shape of the outer edge facing the non-magnetic region is the boundary point P ２１ The shape of the outer edge facing the non-magnetic region is different from that of the boundary point P １２ The shape of the outer edge facing the non-magnetic region is the boundary point P ２２ 2. The rotor according to claim 1, wherein the shape of the outer edge facing the non-magnetic region is different from the shape of the outer edge including the non-magnetic region.

4. A rotor as described in claim 1, characterized in that the rotor core has a portion in which a first electromagnetic steel sheet having only the specified magnetic pole arranged in the circumferential direction and a second electromagnetic steel sheet having only magnetic poles having a shape that is inverted with respect to the M axis of the specified magnetic pole arranged in the circumferential direction are overlapped adjacent to each other in the axial direction.

5. A rotor as described in claim 1, characterized in that the rotor core has a third electromagnetic steel plate in which the specified magnetic pole and a magnetic pole having a shape that is the inverse of the specified magnetic pole about the M axis are arranged alternately in the circumferential direction.

6. A rotor as described in claim 5, characterized in that the rotor core has a portion in which the third electromagnetic steel plate and a fourth electromagnetic steel plate, which is shifted circumferentially from the third electromagnetic steel plate by the mechanical angle of the magnetic pole of the third electromagnetic steel plate, are overlapped adjacent to each other in the axial direction.

7. A rotating electric machine comprising: a rotor as claimed in any one of claims 4 to 6; a stator core formed radially outside the rotor core via a gap to surround the rotor core; and a stator winding having a portion housed in each of a plurality of stator slots formed between a plurality of stator teeth formed in the stator core, wherein, in a cross section perpendicular to the central axis of rotation, the circumferential center line of a non-magnetic region formed to communicate between the stator slots and the inner surface of the stator core as viewed from the inner surface is on the same line as the circumferential center lines of the plurality of stator slots.

8. A stator comprising: a rotor according to claim 5 or 6; a stator core formed so as to surround the rotor core via a gap on the radial outside of the rotor core; and a stator winding having a portion housed in each of a plurality of stator slots formed between a plurality of stator teeth formed in the stator core, wherein, in a cross section perpendicular to the central axis of rotation, the circumferential center lines of non-magnetic regions formed to communicate between the stator slots and the inner peripheral surface of the stator core, as viewed from the inner peripheral surface, are shifted in the same direction relative to the circumferential center lines of the plurality of stator slots, and, in the same cross section, the boundary point P of the rotor core ２１ A rotating electric machine characterized in that the rotor is displaced in a direction of the rotor.

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