JP7461967B2 - Rotating electric machines, rotors and electromagnetic steel sheets - Google Patents

Description

The disclosed embodiments relate to a rotating electric machine, a rotor, and an electromagnetic steel sheet.

Patent document 1 discloses a rotor core for a rotating electric machine in which a group of gaps is provided on the outer periphery of the longitudinal ends of the permanent magnets of the rotor core.

International Publication WO2013/153917

For example, when detecting the rotational position of a rotor without using an encoder, it is necessary to increase the saliency ratio (= inductance in the q-axis direction/inductance in the d-axis direction) as much as possible to improve detection accuracy and obtain good controllability. In the above-mentioned conventional technology, the inductance in the q-axis direction can be increased to a certain extent by devising an arrangement of each gap in the above-mentioned gap group, but further improvement of the saliency ratio is desired.

The present invention has been made in consideration of these problems, and aims to provide a rotating electric machine, rotor, and electromagnetic steel sheet that can improve the salient pole ratio.

In order to solve the above problems, according to one aspect of the present invention, there is provided a rotating electric machine having a rotor core and a plurality of permanent magnets embedded in the rotor core, the rotor core having a plurality of magnetic pole portions formed at a plurality of locations in the circumferential direction according to the arrangement of the plurality of permanent magnets, the plurality of permanent magnets including a plurality of pairs of the permanent magnets arranged in a substantially V-shape in a cross section perpendicular to the axial direction of the rotor core, the magnetic pole portions being formed between the pair of permanent magnets, and The rotor core has a slit disposed between one of the permanent magnets, the slit penetrating the rotor core in the axial direction and having a cross-sectional shape in the cross section that is approximately parallel to the circumferential direction, and when an axis extending from the axis of the rotor core toward the center of the magnetic pole portion is defined as a d-axis and an axis extending in a direction shifted by 90° in electrical angle from the central direction is defined as a q-axis, the pair of permanent magnets and the slit are configured such that a q-axis magnetic flux due to the torque current of the rotating electric machine passes through the region between the one permanent magnet and the other permanent magnet in the cross section.

In addition, in order to solve the above problem, according to another aspect of the present invention, a rotating electric machine is provided that has a rotor core and a plurality of permanent magnets embedded in the rotor core, the rotor core having a plurality of magnetic pole portions formed at a plurality of locations in the circumferential direction according to the arrangement of the plurality of permanent magnets, the plurality of permanent magnets including a pair of the permanent magnets arranged in a substantially V-shape in a cross section perpendicular to the axial direction of the rotor core, the magnetic pole portions being formed between the pair of permanent magnets, the intersection of a first perpendicular bisector of one of the pair of permanent magnets and a second perpendicular bisector of the other of the pair of permanent magnets in the cross section being located inside or on the outer periphery of the rotor core, and a slit is provided between the one permanent magnet and the other permanent magnet that penetrates the rotor core in the axial direction and has a cross-sectional shape in the cross section that is substantially parallel to the circumferential direction.

In addition, in order to solve the above-mentioned problems, according to yet another aspect of the present invention, there is provided a thin-walled, disk-shaped electromagnetic steel sheet used to form a rotating core, the thin-walled, disk-shaped electromagnetic steel sheet having a plurality of embedded holes into which a plurality of permanent magnets are respectively embedded, and a plurality of magnetic pole portions formed at a plurality of locations in the circumferential direction according to the arrangement of the plurality of embedded holes, the plurality of embedded holes including a plurality of pairs of embedded holes arranged in a substantially V-shape, the plurality of embedded holes having a slit hole provided between one embedded hole and the other embedded hole of the pair of embedded holes and substantially parallel to the circumferential direction, the d-axis being an axis extending from the axis of the electromagnetic steel sheet toward the center of the magnetic pole portions, and the q-axis being an axis extending in a direction shifted by 90° in electrical angle from the central direction, the pair of embedded holes and the slit hole are configured such that a q-axis magnetic flux due to the torque current of a rotating electric machine having the rotating core passes through the region between the one embedded hole and the other embedded hole.

In addition, in order to solve the above-mentioned problems, according to yet another aspect of the present invention, a thin-walled, disk-shaped electromagnetic steel sheet used to form a rotating core is provided with a plurality of embedded holes into which a plurality of permanent magnets are respectively embedded, and a plurality of magnetic pole portions formed at a plurality of locations in the circumferential direction according to the arrangement of the plurality of embedded holes, and the plurality of embedded holes include a plurality of pairs of embedded holes arranged in a substantially V-shape, in which the intersection of a first perpendicular bisector of one of the pair of embedded holes and a second perpendicular bisector of the other of the pair of embedded holes is located inside or on the outer periphery of the electromagnetic steel sheet, and a slit hole that is substantially parallel to the circumferential direction is provided between the one embedded hole and the other embedded hole.

According to the present invention, the salient pole ratio can be improved.

1 is a side view illustrating an example of an appearance of a rotating electric machine according to an embodiment; 2 is a view taken along the arrow A in FIG. 1 . 1 is a partially cutaway side view illustrating an example of an internal structure of a rotating electric machine. 4 is a cross-sectional view taken along line IV-IV in FIG. 3, showing an example of the structure of a magnetic pole portion of a rotating electric machine. FIG. 2 is a side view illustrating an example of the overall structure of a rotor. FIG. 2 is a cross-sectional view showing an example of a structure of a rotor core. 7 is a partially enlarged view of FIG. 6 showing the structure of a main part of a rotor core. FIG. 11 is an explanatory diagram showing the distribution of magnetic flux density of the q-axis magnetic flux in and around a permanent magnet in a comparative example in which no slits are provided. FIG. 11 is an explanatory diagram illustrating a typical flow of magnetic flux lines in and around a permanent magnet in a comparative example in which no slits are provided. FIG. 4 is an explanatory diagram illustrating the distribution of magnetic flux density of q-axis magnetic flux in and around a permanent magnet in one embodiment. FIG. 2 is a schematic explanatory diagram illustrating typical magnetic flux lines in and around a permanent magnet according to one embodiment. 13 is a cross-sectional view showing a main structure of a rotor core in a modified example in which slits of a different shape are provided. FIG. 13 is a cross-sectional view showing a main structure of a rotor core in a modified example in which slits of yet another shape are provided. FIG.

One embodiment will be described below with reference to the drawings.

<Overall configuration of rotating electric machine>
First, the configuration of a rotating electric machine 1 according to an embodiment will be described with reference to Figures 1, 2, 3, 4, and 5. As shown in Figures 1 to 3, the rotating electric machine 1 is configured as a so-called inverter-integrated rotating electric machine, and has a main body section 100 and an inverter section 300. Note that instead of such an inverter-integrated type, the rotating electric machine may be a rotating electric machine that is separate and independent from the inverter. The rotating electric machine 1 may be used as a motor or a generator.

<Main body>
3, the main body 100 includes a stator 2 and a rotor 3, and in this example, is an inner rotor type motor with the rotor 3 inside the stator 2. The rotating electric machine 1 is, for example, a three-phase AC motor for so-called sensorless control, which detects and controls the magnetic pole position by electrical processing without using a mechanical sensor such as an encoder.

As shown in Figures 3 and 4, the stator 2 is provided on the inner peripheral surface of the frame 4 via a cylindrical yoke (not shown) so as to face the rotor 3 in the radial direction. The stator 2 has a stator core 5, a bobbin 6 attached to the stator core 5, and a coil 7 wound around the bobbin 6. The bobbin 6 is made of an insulating material to electrically insulate the stator core 5 from the coil 7. The frame 4 may be provided with cooling holes (not shown) for cooling.

The rotor 3 is provided on the outer circumferential surface of the shaft 10. The shaft 10 is rotatably supported by a load side bearing 12 having an outer ring fitted to a load side bracket 11 provided on the load side (right side in FIG. 1) of the frame 4, and a counter-load side bearing 14 having an outer ring fitted to a counter-load side bracket 13 provided on the counter-load side (opposite the load side; left side in FIG. 1) of the frame 4. As shown in FIG. 4, the rotor 3 includes a rotor core 20 and a plurality of permanent magnets 21 provided on the rotor core 20.

<Inverter section>
3, the inverter unit 300 includes a casing 301, an inverter main body 302 provided in the casing 301 and including an inverter circuit, and a cover 304. The inverter circuit generates a three-phase AC current from an appropriate AC power source and supplies the three-phase AC current to the main body 100.

A cooling fan 150 is provided between the inverter unit 300 and the main body unit 100. When the fan 150 rotates, air is taken in through the cover 304 to cool the inverter unit 300, cool the outer periphery of the stator 2, and is discharged from the load side bracket 11.

<Stator core>
In this example, the stator core 5 is formed of a laminated body in which a plurality of substantially annular electromagnetic steel sheets are stacked in the thickness direction (axial direction of the shaft 10). As shown in Fig. 4, the stator core 5 includes the cylindrical yoke and a plurality of teeth 18 (12 in the illustrated example) equally spaced on the inner periphery side of the yoke. Each tooth 18 has a main body portion 18a provided so as to protrude from the cylindrical yoke to the inner periphery side, and an expanded portion 18b located at the base of the inner periphery side of the main body portion 18a and having a circumferential dimension larger than that of the main body portion 18a.

The widened portions 18b connect adjacent teeth 18, 18 to each other. In other words, the stator core 5 is configured such that the cylindrical yoke and the multiple teeth 18 connected in a cylindrical shape by connecting the widened portions 18b are separated. The stator 2 is assembled by attaching the bobbins 6 around which the coils 7 are wound in a concentrated manner to each tooth 18 and fixing the multiple teeth 18 connected in a cylindrical shape to the inner circumference of the yoke. The stator 2 assembled by fixing the multiple cylindrical teeth 18 to the yoke is attached to the inner circumference of the frame 4. Resin is then pressed in, and the bobbins 6, coils 7, etc. are molded with resin.

<Rotor core>
As shown in Fig. 5, in this example, the rotor core 20 is formed of a laminated body in which a plurality of thin disk-shaped (approximately annular) electromagnetic steel sheets 20A are laminated in the thickness direction (axial direction of the shaft 10). As shown in Fig. 4, the rotor core 20 has a plurality of magnetic pole portions 55 (eight in this example) formed at a plurality of locations in the circumferential direction (rotation direction) according to the arrangement of the plurality of permanent magnets 21 on the outer periphery. As a result, the rotating electric machine 1 of this embodiment has a so-called 8P12S (8 poles, 12 slots) slot combination configuration. However, the slot combination configuration of the rotating electric machine 1 may be other than the above.

<Magnetic pole part>
Next, an example of the configuration of each magnetic pole portion 55 will be described with reference to Fig. 6 and Fig. 7. In Fig. 6, the rotor core 20 is a so-called IPM type (Internal Permanent Magnet). That is, the rotor core 20 (in other words, the electromagnetic steel sheet 20A, the same applies below) is formed with a plurality of embedding holes 71 for embedding and arranging each permanent magnet 21. In detail, in a cross section perpendicular to the axial direction of the rotor core 20 (hereinafter referred to as an axial cross section), a pair of embedding holes 71, 71 (corresponding to an example of a first hole and an example of a second hole, respectively) arranged in a substantially V-shape that opens toward the outer periphery are formed in a plurality of pairs on the outer periphery of the rotor core 20. At this time, each pair of embedding holes 71, 71 communicates with each other via a communication hole 72 (an example of an air gap) located at the lower end of the substantially V-shape. That is, the rotor core 20 is formed by stacking electromagnetic steel sheets 20A in which the embedding holes 71, 71 and the communication holes 72 are formed by punching or the like together with the slits 200 described below.

The permanent magnet 21 is formed, for example, in a substantially rectangular shape, and its size (cross-sectional area in a cross section perpendicular to the axis) is substantially the same as the size (cross-sectional area in a cross section perpendicular to the axis) of the embedding hole 71. The permanent magnet 21 is inserted axially into each of the embedding holes 71, fixed with adhesive, and embedded. As a result, in the rotor core 20, a pair of permanent magnets 21, 21 arranged in a substantially V-shape that opens toward the outer periphery is embedded in multiple pairs on the outer periphery of the rotor core 20. The region (the inner circumferential angle region of the V-shape) between the pair of permanent magnets 21, 21 arranged in a substantially V-shape of the rotor core 20 becomes the magnetic pole portion 55. In this example, in the substantially V-shape arrangement, the angle between the two sides constituting the V-shape is relatively small, resulting in a deep V-shape. As a result, in the above-mentioned axially orthogonal cross section, for example, an intersection C between a perpendicular bisector H1 (an example of a first perpendicular bisector) of the permanent magnet 21L (an example of one permanent magnet) shown on the left side of Fig. 7 and a perpendicular bisector H2 (an example of a second perpendicular bisector) of the permanent magnet 21R (an example of the other permanent magnet) shown on the right side of Fig. 7 is located inside the rotor core 20 (radially inward from the arc surface 55a). Note that the intersection C may be located on the outer periphery of the rotor core 20 (on the arc surface 55a).

In addition, the surface (arcuate surface 55a) of the area of the outer peripheral side of the rotor core 20 facing the stator core 5, which is sandwiched between a pair of permanent magnets 21, 21, is sometimes referred to as the magnetic pole portion, but in this embodiment, the magnetic pole portion also includes the internal area sandwiched between a pair of permanent magnets 21, 21, which is the area radially inward of the arcuate surface 55a.

The pair of permanent magnets 21, 21 in each magnetic pole portion 55 are magnetized in such a way that the magnetic flux faces each other in the magnetic pole portion 55 of the N pole, and the magnetic flux moves away from each other in the magnetic pole portion 55 of the S pole. That is, the magnetic pole portion 55 in which the pair of permanent magnets 21, 21 are magnetized so that the magnetic flux faces each other becomes the magnetic pole portion of the N pole, and the magnetic pole portion 55 in which the pair of permanent magnets 21, 21 are magnetized so that the magnetic flux moves away from each other becomes the magnetic pole portion of the S pole. The multiple magnetic pole portions 55 are arranged at equal intervals in the circumferential direction so that adjacent magnetic pole portions 55 in the circumferential direction have opposite polarities. Note that the above "equally spaced" does not have a strict meaning, and design and manufacturing tolerances, errors, etc. are allowed. In other words, it means "substantially equally spaced."

<Slit>
Between the pair of permanent magnets 21, 21 arranged in a substantially V-shape in the rotor core 20, a slit 200 is provided that penetrates the rotor core 20 in the axial direction and has a cross-sectional shape that is substantially parallel to the circumferential direction of the rotor core 20 in the cross-sectional plane perpendicular to the axis. In other words, the electromagnetic steel sheet 20A described above has a slit hole corresponding to the slit 200, and a plurality of electromagnetic steel sheets 20A having the slit hole are laminated to form the slit 200 in the rotor core 20. In this example, the cross-sectional shape of the slit 200 is substantially rectangular (approximately oblong), and the short side of the substantially rectangular (approximately oblong) is aligned along the radial direction and the long side is substantially parallel to the circumferential direction. In this example, in the cross-sectional plane perpendicular to the axis, the slit 200 is located radially inward of the rotor core 20 relative to the perpendicular bisector H1 and the perpendicular bisector H2, and is arranged so that the perpendicular bisector H3 (an example of a third bisector) of the slit 200 passes through the communication hole 72. Furthermore, the long side of the substantial rectangle (approximately rectangular) faces the communication hole 72 in the radial direction of the rotor core 20 (the up-down direction in FIG. 7).

<Effects of the embodiment>
In the rotor core 20 of this embodiment configured as above, the effects obtained by providing the slits 200 will be described below.

As described above, in the rotating electric machine 1 of this embodiment, a plurality of permanent magnets 21 are embedded and arranged in the rotor core 20. In this case, when the rotating electric machine 1 is in operation, demagnetizing fields act on the ends of the permanent magnets 21 from various directions depending on, for example, the magnitude and lead angle of the current flowing through the coil 7 provided in the stator 2, the rotation angle of the rotor 3, the magnetic circuit structure of the rotor 3, etc.

In this embodiment, in the cross section of the rotor core 20 in the cross section perpendicular to the axis, the pair of permanent magnets 21, 21 are arranged in an approximately V-shape, and circumferentially parallel slits 200 are provided between the pair of permanent magnets 21, 21.

In this embodiment, in the cross section perpendicular to the axis, the intersection C of the perpendicular bisectors H1, H2 of the pair of permanent magnets 21, 21 is located inside the rotor core 20 (or may be on the outer periphery). In other words, the depth of the V-shape is relatively deep, and the area of the approximately sector-shaped area (= magnetic pole portion 55) sandwiched by the pair of V-shaped permanent magnets 21, 21 is wide. Then, in the sector-shaped area with a wide area, a slit 200 is provided parallel to the circumferential direction. As a result, when the axis extending from the axis of the rotor core 20 toward the center of the magnetic pole portion 55 is the d-axis, and the axis extending in a direction shifted by 90° in electrical angle from the center direction is the q-axis, the q-axis magnetic flux due to the torque current coming from the outer periphery of the rotor core 20 easily passes through the sector-shaped area (magnetic pole portion 55) where the slit 200 is located. In other words, the sector-shaped area (magnetic pole portion 55) functions as a magnetic path in the q-axis direction. This will be explained with reference to FIGS. 8A and 8B and FIGS. 9A and 9B.

8A and 9A are explanatory diagrams showing the distribution of the magnetic flux density of the q-axis magnetic flux in the permanent magnet 21 arranged in a V-shape in the above-mentioned axial cross section and its periphery, which were obtained by the inventors of the present application through analysis, and Figs. 8B and 9B correspond to Figs. 8A and 9A, respectively, and are explanatory diagrams showing the flow of typical magnetic flux lines. As shown on the right side of Figs. 8A and 9A, the magnetic flux density is divided into seven magnetic flux density zones, "A", "B", "C", "D", "E", "F", and "G", from low density to high density, and the distribution of each magnetic flux density zone in the above-mentioned axial cross section is shown. Fig. 8A shows the distribution of the magnetic flux density zone in the case where the slit 200 is not provided as a comparative example, and Fig. 9A shows the distribution of the magnetic flux density zone in the above-mentioned embodiment in which the slit 200 is provided.

In the embodiment shown in FIG. 9A, the magnetic flux density band of "C" extending diagonally from the upper left to the lower right in the figure is pulled to the lower left side compared to the comparative example of FIG. 8A by the action of the slit 200 (see arrows a, b, c, and d in FIG. 9A), and as a result, the size of the magnetic flux density band of "B" which is a low density area adjacent to the lower left side is reduced. In addition, the magnetic flux density band of "D" which is a high density area adjacent to the upper right of the magnetic flux density band of "C" is also pulled to the lower left side (see arrows e and f in FIG. 9A), and the size of the magnetic flux density band of "D" is expanded. In other words, the slit 200 causes the sector area (magnetic pole part 55) to function as a magnetic path in the q-axis direction, making it easier for the magnetic path of the q-axis magnetic flux to pass through the magnetic pole part 55, and the magnetic flux penetrates and passes at least radially inward of the envelope line LL connecting the outer circumferential ends of each permanent magnet 21. 9B, compared to FIG. 8B, the magnetic flux lines ML of the q-axis magnetic flux passing outside the coil 7 are attracted to the slits 200, and as a result, the high magnetic flux density region in the magnetic pole portion 55 is expanded, and the inductance in the q-axis direction can be made sufficiently large. As a result, the salient pole ratio can be improved.

In this embodiment, in particular, in the cross section perpendicular to the axis, the slits 200 are located radially inward of the rotor core 20 from the mutually intersecting perpendicular bisectors H1 and H2. As a result, the slits 200 are located deep inside the V-shape, improving the branching effect of the demagnetizing field.

In this embodiment in particular, the cross-sectional shape of the slit 200 is approximately rectangular in the cross section perpendicular to the axis.

In this embodiment, the slit 200 is arranged such that the long side of the approximately rectangular shape in the axially orthogonal cross section faces the communication hole 72 in the radial direction of the rotor core 203. This allows the communication hole 72 to facilitate the passage of the q-axis magnetic flux through the portion of the region (magnetic pole portion 55) between the permanent magnets 21, 21 arranged in the V-shape that is outside the slit 200, thereby ensuring that this portion functions as a magnetic path in the q-axis direction.

In this embodiment, the communication hole 72 is connected to each of a pair of embedded holes 71, 71 arranged in a V-shape. This allows the two embedded holes 71, 71 and the communication hole 72 to be drilled relatively easily as a single continuous body when manufacturing the rotor core 20.

In this embodiment, the perpendicular bisector H3 of the slit 200 in the cross section perpendicular to the axis passes through the communication hole 72. This allows the circumferential center position of the slit 200 to approximately coincide with the circumferential center position of the V-shape when the embedded holes 71, 71 and the permanent magnets 21, 21 are arranged.

<Other Modifications>
As described above with reference to FIG. 7, the intersection C between the perpendicular bisector H1 of the permanent magnet 21L and the perpendicular bisector H2 of the permanent magnet 21R is located inside or on the outer periphery of the rotor core 20, but the present invention is not limited to this. That is, the intersection C may be slightly spaced radially outward from the outer periphery (arcuate surface 55a) of the rotor core 20. In this case, the distance (amount of space) from the intersection C to the arcuate surface 55a may be, for example, equal to or less than the thickness direction (radial dimension) t of the slit 200 in the cross section perpendicular to the axis, or equal to or less than the thickness direction dimension T of the permanent magnet 21. In these cases, the q-axis magnetic flux due to the torque current can be configured to pass through the region between the permanent magnets 21L and 21R, as described above, and the same effect as described above can be obtained.

In the above example, as shown in FIG. 7, the cross-sectional shape of the slit 200 is approximately rectangular as an example of the case where the slit 200 is approximately parallel to the circumferential direction in the axial cross section, but this is not limited to this. That is, as shown in FIG. 10, the slit 200 may be approximately arc-shaped. In this case, instead of the downward convex shape as shown in the figure, an upward convex shape in a state in which the shape is inverted upside down may be considered. Alternatively, as shown in FIG. 11, the slit 200 may be approximately V-shaped. In this case, it is also possible to have an inverted V-shape in a state in which the shape shown in the figure is inverted upside down. The definition of "approximately parallel to the circumferential direction" in this specification includes cases where the slit 200 has a cross-sectional shape (not approximately rectangular) as described above. In any case, as described above, it is sufficient that the q-axis magnetic flux due to the torque current passes through the area between the permanent magnets 21L and 21R, and this configuration provides the same effect as described above.

In addition to what has already been described above, the methods according to the above embodiments and variations may be used in appropriate combination.

In addition, although we will not provide examples, the above embodiments can be implemented with various modifications without departing from the spirit of the invention.

REFERENCE SIGNS LIST 1 rotating electric machine 3 rotor 20 rotor core 20A electromagnetic steel sheet 21 permanent magnet 55 magnetic pole portion 55 arc portion (an example of the outer periphery of a rotor core)
71 Burying hole (an example of a first hole, an example of a second hole)
72 Communication hole (an example of a gap)
200 Slit C Intersection H1 Perpendicular bisector (an example of the first perpendicular bisector)
H2 perpendicular bisector (an example of a second perpendicular bisector)
H3 Perpendicular bisector (an example of the third perpendicular bisector)

Claims (4)

A rotor core;
A plurality of permanent magnets embedded in the rotor core;
having
the rotor core includes a plurality of magnetic pole portions formed at a plurality of locations in a circumferential direction in accordance with an arrangement of the plurality of permanent magnets,
the plurality of permanent magnets include a plurality of pairs of the permanent magnets arranged in a substantially V-shape in a cross section perpendicular to an axial direction of the rotor core,
The magnetic pole portion is formed between the pair of permanent magnets.
A rotating electric machine,
an intersection of a first perpendicular bisector of one of the pair of permanent magnets and a second perpendicular bisector of the other of the pair of permanent magnets in the transverse cross section is located inside or on an outer periphery of the rotor core;
a slit is provided between the one permanent magnet and the other permanent magnet, the slit penetrating the rotor core in the axial direction and having a cross-sectional shape in the transverse cross section that is substantially parallel to the circumferential direction;
The slit is
In the transverse cross section, the magnet is located in a region surrounded by the first perpendicular bisector and the second perpendicular bisector which intersect with each other, and the one permanent magnet and the other permanent magnet,
a shape of the slit in the cross section is a substantially rectangular shape that is elongated in the circumferential direction, the short side of the slit being aligned along a radial direction of the rotor core and the long side of the slit being substantially parallel to the circumferential direction ,
The rotor core is
a first hole into which the one permanent magnet is inserted and disposed, a second hole into which the other permanent magnet is inserted and disposed, and a gap located between the first hole and the second hole,
The slit is
A long side of the substantially rectangular shape in the cross section is disposed opposite to the gap in the radial direction,
The void is
each of the first hole and the second hole is in communication with the
A third perpendicular bisector of the slit in the cross section passes through the gap.
A rotating electric machine characterized by: A thin, disk-shaped electromagnetic steel sheet used for forming a rotor core, the thin, disk-shaped electromagnetic steel sheet having a plurality of embedding holes into which a plurality of permanent magnets are respectively embedded, and a plurality of magnetic pole portions formed at a plurality of locations in a circumferential direction according to an arrangement of the plurality of embedding holes, the plurality of embedding holes including a plurality of pairs of embedding holes arranged in a substantially V-shape,
an intersection of a first perpendicular bisector of one of the pair of embedment holes and a second perpendicular bisector of the other of the pair of embedment holes is located inside or on an outer periphery of the electromagnetic steel sheet,
a slit hole is provided between the one embedding hole and the other embedding hole, the slit hole being substantially parallel to the circumferential direction;
The slit hole is
the first perpendicular bisector and the second perpendicular bisector intersecting with each other, and the one embedment hole and the other embedment hole are located in a region surrounded by the first perpendicular bisector and the second perpendicular bisector which intersect with each other,
The shape of the slit hole is a substantially rectangular shape that is elongated in the circumferential direction, with a short side aligned along a radial direction of the electromagnetic steel sheet and a long side substantially parallel to the circumferential direction ,
The electromagnetic steel sheet is
a gap is provided between the one embedment hole and the other embedment hole;
The slit hole is
The long side of the substantially rectangular shape is disposed opposite to the gap in the radial direction,
The void is
the one embedding hole and the other embedding hole are respectively connected to each other,
A third perpendicular bisector of the slit passes through the gap.
1. An electrical steel sheet comprising: A rotor comprising a plurality of magnetic steel sheets according to claim 2 laminated in the axial direction and a plurality of permanent magnets embedded in the embedding holes. A rotating electric machine comprising the rotor according to claim 3 .

Images