JP2020188585A - Rotor core for rotary electric machine - Google Patents

Abstract

To provide a rotor core for a rotary electric machine which can reduce a leakage magnetic flux with the suppression of strength deterioration.SOLUTION: A rotor core 10 includes: an iron core 11 of a cylindrical shape; a plurality of insertion holes 13 penetrating through in the center line direction of the iron core 11 in a mode of being placed in alignment with intervals in the circumferential direction of the iron core 11; and permanent magnets 14 fixed in the state housed inside the insertion holes 13. A slit 20 is provided at a bridge part 16 sandwiched between two neighboring insertion holes 13. When a virtual line VL1 is drawn in a direction orthogonal to the alignment direction of the two insertion holes 13 in a state that the end part of the iron core 11 is seen in the center line direction, the slit 20 extends in a direction obliquely intersecting the virtual line VL1.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotor core of a rotary electric machine.

A rotor core of a magnet-embedded rotary electric machine is known (see Patent Document 1). This rotor core has a cylindrical iron core portion. The iron core portion is provided with a plurality of insertion holes penetrating in the center line direction so as to be arranged at intervals in the peripheral direction. Permanent magnets are inserted and fixed in each insertion hole of the iron core.

JP-A-2018-133906

In the magnet-embedded rotor core, a part of the magnetic flux (so-called leakage flux) emitted from the N pole side of the permanent magnet is passed through the portion sandwiched between the adjacent insertion holes in the iron core (hereinafter referred to as the bridge portion). It flows wastefully so as to return to the S pole side of the permanent magnet without going to the stator of. By making the bridge portion thinner, such leakage flux can be reduced. However, if the bridge portion is simply thinned, the strength of the bridge portion is lowered, and the strength of the rotor core is lowered.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rotor core of a rotary electric machine capable of reducing leakage flux while suppressing a decrease in strength.

The rotor core of the rotary electric machine for solving the above-mentioned problems is arranged so as to penetrate the cylindrical iron core portion in the direction of the center line of the iron core portion in such a manner that the rotor core is arranged at intervals in the peripheral direction of the iron core portion. In the rotor core of a rotary electric machine having a plurality of insertion holes provided in the above and a permanent magnet fixed in a state of being accommodated inside the insertion holes, an end portion of the iron core portion was seen in the center line direction. When a virtual line extending in a direction orthogonal to the arrangement direction of the adjacent insertion holes is drawn in the state, a slit extending in a direction diagonally intersecting the virtual line at a portion sandwiched between the adjacent insertion holes. Has.

The smaller the minimum value of the cross-sectional area of each part (bridge part) sandwiched between adjacent insertion holes in the iron core part, the higher the magnetoresistance and the easier it is for magnetic flux saturation.
According to the above configuration, by providing a slit in the bridge portion of the iron core portion, the structure of the bridge portion can be divided into a plurality of divided structures. In the above configuration, the cross-sectional shape of the slit extends diagonally with respect to the direction orthogonal to the arrangement direction of the adjacent insertion holes. Therefore, by providing the slit, the distance between one end of the slit and one of the adjacent insertion holes is reduced, and the distance between the other end of the slit and the other of the adjacent insertion holes is reduced. be able to. As a result, a portion having a short distance, that is, a portion having a small cross-sectional area can be formed in each of the divided portions divided by the slits in the bridge portion. Therefore, the bridge portion can have a structure in which the magnetic flux does not easily pass through, and the leakage flux can be reduced. Moreover, although a part of the bridge portion is cut out, since the portion is slit-shaped, the cross-sectional area of the cutout portion can be reduced. As a result, it is possible to suppress a decrease in the cross-sectional area of the entire bridge portion, so that it is possible to suppress a decrease in the strength of the bridge portion and, by extension, a decrease in the strength of the rotor core.

According to the rotor core of the rotary electric machine of the present invention, it is possible to reduce the leakage flux while suppressing the decrease in strength.

(A) is a plan view and (b) is a side view of the rotor core of the first embodiment. A plan view showing an enlarged view of the bridge portion of the rotor core and its periphery. The explanatory view for demonstrating the operation by the slit of 1st Embodiment. The plan view of the bridge part of the rotor core of 2nd Embodiment and its periphery. The explanatory view for demonstrating the operation by the slit of 2nd Embodiment.

(First Embodiment)
Hereinafter, the first embodiment of the rotor core of the rotary electric machine will be described.
As shown in FIGS. 1A and 1B, the rotor core 10 has a cylindrical iron core portion 11. The iron core portion 11 has a structure in which a plurality of annular plate-shaped metal plates are laminated. The rotor core 10 is fixed to the rotor shaft with the rotor shaft inserted into the central hole 12 of the iron core portion 11. The rotor core 10 of the present embodiment constitutes the rotor of the electric motor together with the rotor shaft.

A plurality of insertion holes 13 penetrating in the extending direction of the center line L of the rotor core 10 (hereinafter, the center line L direction) are arranged in the iron core portion 11 at intervals in the peripheral direction of the iron core portion 11 (this implementation). In the form, 20 pieces) are provided. Specifically, the iron core portion 11 is formed with ten pairs of insertion holes 13 adjacent to each other in the peripheral direction. The two paired insertion holes 13 each have an elongated cross-sectional shape, and extend so as to be closer to each other on the inner peripheral side.

A permanent magnet 14 is inserted and housed inside each insertion hole 13. The permanent magnet 14 has a rectangular cross-sectional shape that is long in the longitudinal direction of the cross section of the insertion hole 13. The permanent magnet 14 is fixed to the iron core portion 11 (specifically, the inner surface of the insertion hole 13) via a filler 15 made of a thermosetting epoxy resin. In the rotor core 10, a pair of permanent holes 13 inserted and fixed in the two insertion holes 13 surrounded by the alternate long and short dash line in FIG. 1A, that is, the two insertion holes 13 located on the inner peripheral side closer to each other. Each magnetic pole of the electric motor is formed by the magnet 14.

The rotor core 10 has 10 poles (5 pole pairs), and has a structure in which magnetic poles having "N poles" and magnetic poles having "S poles" are alternately arranged in the peripheral direction.
In the rotor core 10 of the present embodiment, at each magnetic pole, a part of the magnetic flux emitted from the north pole side of the permanent magnet 14 via the portion (hereinafter, the bridge portion 16) sandwiched between the adjacent insertion holes 13 in the iron core portion 11. It is inevitable that (so-called leakage flux) flows wastefully so as to return to the S pole side of the permanent magnet 14 without going to the stator of the motor.

Therefore, in the present embodiment, in order to suppress such leakage flux, as shown in FIGS. 1 and 2, a slit 20 having a cut shape is provided in the bridge portion 16 at each magnetic pole. Hereinafter, the shape of the slit will be described in detail.

The slit 20 is extended so as to penetrate the iron core portion 11 in the center line L direction. The slit 20 has an elongated hole shape in cross section. The bridge portion 16 is a portion that connects the ends of the pair of insertion holes 13, and a slit 20 is provided in the bridge portion 16. In the present embodiment, one slit 20 is provided in the bridge portion 16 of each magnetic pole.

In the present embodiment, when the end portion of the iron core portion 11 is viewed in the center line L direction (the state shown in FIG. 2), it is orthogonal to the arrangement direction of the two insertion holes 13 at each magnetic pole (the left-right direction in FIG. 2). When the virtual line VL1 extending in the direction is drawn, the slit 20 extends in the direction diagonally intersecting the virtual line VL1 at the bridge portion 16. Each slit 20 extends linearly in the L direction of the center line while looking at the end of the iron core portion 11. The above-mentioned "diagonally intersecting direction" is a direction in which the angle θ formed by the extending direction of the cross-sectional shape of the slit 20 and the virtual line VL1 satisfies the relational expression “0 degree <θ <90 degree”.

In the present embodiment, the shape of the slit 20 is a shape that satisfies both the following [Condition A] and [Condition B]. [Condition A] The distance between one of the two insertion holes 13 (left side in FIG. 2) and the slit 20 at each magnetic pole gradually narrows toward the inner peripheral side (upper side in FIG. 2) of the rotor core 10. [Condition B] The distance between the other of the two insertion holes 13 at each magnetic pole (right side in FIG. 2) and the slit 20 gradually decreases toward the outer peripheral side (lower side in FIG. 2) of the rotor core 10.

Hereinafter, the action of providing the slit 20 will be described together with the effect.
The maximum density of the magnetic flux passing through the bridge portion 16 in the iron core portion 11 is determined by the minimum value among the cross-sectional areas of each portion of the bridge portion 16. Specifically, the smaller the minimum value of the cross-sectional area of each portion of the bridge portion 16, the higher the magnetoresistance and the easier it is for magnetic flux saturation. From this, it can be said that the bridge portion 16 may be provided with a portion having a small cross-sectional area in order to suppress the leakage flux.

Based on this point, in the present embodiment, as shown in FIG. 3, a slit 20 extending obliquely in the bridge portion 16 of the iron core portion 11 with respect to the direction orthogonal to the arrangement direction of the two insertion holes 13 of each magnetic pole. Is provided. Due to the slit 20, the structure of the bridge portion 16 is divided into two in the peripheral direction. Then, one of the two divided portions (first divided portion 21) of the bridge portion 16 gradually becomes narrower toward the inner peripheral side (upper side in FIG. 3), and the other (first divided portion 21). The second divided portion 22) has a shape that gradually narrows toward the outer peripheral side (lower side in FIG. 3).

In the portion where the magnetic pole is "N pole" in the rotor core 10, magnetic flux flows through the bridge portion 16 as follows.
As shown by the solid white arrows in FIG. 3, the magnetic flux from the outer peripheral side of the permanent magnet 14 toward the bridge portion 16 is the second division portion having a narrow inlet (specifically, the end portion on the outer peripheral side). It is hardly guided to 22, and most of it is guided to the first division 21 having a wide entrance.

In the first division portion 21, the width of the entrance is wide, but the width of the exit (W1 in FIG. 3) is narrow. Specifically, the first division portion 21 has a tapered shape in which the width becomes narrower toward the exit (specifically, the inner peripheral side). Therefore, the magnetic flux density of the first partition portion 21 tends to reach the maximum magnetic flux density at the end on the outlet side where the cross-sectional area is the smallest.

Then, when the maximum magnetic flux density of the iron core material of the first divided portion 21 and the actual magnetic flux density match, the magnetic flux density becomes saturated (so-called magnetic saturation state). Therefore, in this case, the leakage flux can be suppressed.

On the other hand, in the portion of the rotor core 10 where the magnetic pole is the "S pole", magnetic flux flows through the bridge portion 16 as follows.
As shown by the broken white arrow in FIG. 3, the magnetic flux from the inner peripheral side of the permanent magnet 14 toward the bridge portion 16 has a narrow inlet (specifically, the end on the inner peripheral side). It is hardly guided to the split portion 21, and most of it is guided to the second split portion 22 having a wide entrance.

The second division portion 22 has a wide entrance but a narrow exit width (W2 in FIG. 3). Specifically, the second division portion 22 has a tapered shape in which the width becomes narrower toward the outlet (specifically, the outer peripheral side). Therefore, the magnetic flux density of the second divided portion 22 tends to reach the maximum magnetic flux density at the end on the outlet side where the cross-sectional area is the smallest.

Then, when the maximum magnetic flux density of the iron core material of the second divided portion 22 and the actual magnetic flux density match, the magnetic flux density becomes saturated and the magnetic saturation state is established. Therefore, even in this case, the leakage flux can be suppressed.

According to the rotor core 10 of the present embodiment, by providing the slit 20, the distance between one end of the slit 20 (upper side of FIG. 3) and one of the two insertion holes 13 at each magnetic pole (left side of FIG. 3). W1 can be reduced, and the distance W2 between the other end of the slit 20 (lower side of FIG. 3) and the other end of the two insertion holes 13 (right side of FIG. 3) can be reduced. As a result, a portion having a short distance, that is, a portion having a small cross-sectional area can be formed in each of the divided portions 21 and 22 divided by the slit 20 in the bridge portion 16. Therefore, the bridge portion 16 can have a structure in which the magnetic flux does not easily pass through, and the leakage flux can be reduced.

Moreover, in the present embodiment, although a part of the bridge portion 16 is cut out to provide the slit 20 in order to reduce the cross-sectional area of the bridge portion 16, the slit 20 is cut out because it has a cut shape. The cross-sectional area of the part is kept small. As a result, a decrease in the cross-sectional area of the entire bridge portion 16 can be suppressed, so that a decrease in the strength of the bridge portion 16 and eventually a decrease in the strength of the rotor core 10 can be suppressed.

In the present embodiment, the slit 20 extends in a straight line having substantially the same width when the end portion of the iron core portion 11 is viewed in the center line L direction. Therefore, in the cross section of the iron core portion 11 in the alignment direction (horizontal direction in FIG. 3) and the center line L direction, the cross-sectional area of the portion cut out to form the slit 20 is substantially the same in each radial direction. .. As a result, it is possible to suppress variations in the radial direction of the cross-sectional area of the portion cut out of the bridge portion 16 in order to form the slit 20. Therefore, the shape of the slit 20 can be easily set in a manner of ensuring the strength of each portion of the bridge portion 16.

Further, in the present embodiment, both ends of the bridge portion 16 provided with such a slit 20 in the alignment direction, in other words, the ends of the two insertion holes 13 of each magnetic pole on the side close to each other extend in parallel in the radial direction. There is. Therefore, the cross-sectional area of the cross section of the portion of the bridge portion 16 provided with the slit 20 in the alignment direction and the center line L direction can be made substantially the same in each portion in the radial direction.

As described above, according to the present embodiment, the effects described below can be obtained.
(1) When a virtual line VL1 extending in a direction orthogonal to the alignment direction of the two insertion holes 13 in the magnetic pole is drawn while looking at the end of the iron core portion 11 in the center line L direction, the bridge portion 16 is virtual. A slit 20 extending in a direction diagonally intersecting the line VL1 is provided. Therefore, the bridge portion 16 can have a structure in which the magnetic flux does not easily pass through, and the leakage flux can be reduced. Moreover, since the slit 20 has a cut shape, it is possible to suppress a decrease in the cross-sectional area of the entire bridge portion 16, and it is possible to suppress a decrease in the strength of the bridge portion 16 and eventually a decrease in the strength of the rotor core 10.

(2) The slit 20 extends in a straight line having substantially the same width when the end portion of the iron core portion 11 is viewed in the center line L direction. Therefore, the shape of the slit 20 can be easily set in a manner of ensuring the strength of each portion of the bridge portion 16.

(3) Only one slit 20 is provided in each bridge portion 16. Therefore, as compared with the case where a plurality of slits are provided in one bridge portion, the structure of the rotor core 10 can be made a structure in which a decrease in the cross-sectional area of the bridge portion 16 due to the arrangement of the slits 20 can be easily suppressed.

(Second Embodiment)
Hereinafter, the second embodiment of the rotor core of the rotary electric machine will be described focusing on the differences from the first embodiment.

Only the shape of the slit is different between the rotor core of the present embodiment and the rotor core 10 of the first embodiment. Hereinafter, the slit of this embodiment will be described. In the following, among the respective configurations of the rotor cores of the present embodiment, the same reference numerals or corresponding reference numerals will be given to the same configurations as those of the rotor core 10 of the first embodiment, and duplicate description of these configurations will be omitted. To do.

As shown in FIG. 4, in the rotor core 30 of the present embodiment, two slit-shaped slits 40 and 41 are provided for the bridge portion 36 of each magnetic pole. The slits 40 and 41 have an elongated hole shape in cross section, and are extended so as to penetrate the iron core portion 31 in the center line L direction.

In the present embodiment, the end portion of the iron core portion 31 is viewed in the center line L direction (state shown in FIG. 4), and is orthogonal to the arrangement direction of the two insertion holes 13 at each magnetic pole (left-right direction in FIG. When the virtual line VL2 extending in the direction is drawn, the slits 40 and 41 extend in the direction diagonally intersecting the virtual line VL2 at the bridge portion 36. Each of the slits 40 and 41 extends linearly in the L direction of the center line while looking at the end of the iron core portion 31.

The two slits 40, 41 of each magnetic pole are arranged in such a manner that they are plane-symmetrical with a plane extending in the radial direction and the center line L direction of the iron core portion 31 as a plane of symmetry. The two slits 40 and 41 have a cross-sectional shape in which the end portion of the iron core portion 11 is viewed in the L direction of the center line, and the distance between the two slits 40 and 41 becomes wider toward the outer peripheral side. There is.

In the present embodiment, the two slits 40 and 41 of each magnetic pole have a shape that satisfies all of the following [condition C], [condition D], and [condition E]. [Condition C] The distance between one of the two insertion holes 13 (left side in FIG. 4) and one of the two slits 40 and 41 (first slit 40) at each magnetic pole is the outer peripheral side of the rotor core 30 (FIG. 4). It gradually narrows toward the lower side). [Condition D] As the distance between the other of the two insertion holes 13 (on the right side in FIG. 4) and the other of the two slits 40 and 41 (second slit 41) at each magnetic pole becomes toward the outer peripheral side of the rotor core 30. Gradually narrows. [Condition E] The distance between the two slits 40 and 41 gradually narrows toward the inner peripheral side (upper side in FIG. 4) of the rotor core 30.

Hereinafter, the action of providing the slits 40 and 41 will be described together with the effect.
In the present embodiment, as shown in FIG. 5, the bridge portion 36 of the iron core portion 31 has two slits 40, 41 extending obliquely with respect to the direction orthogonal to the alignment direction of the two insertion holes 13 of each magnetic pole. It is provided. The structure of the bridge portion 36 is divided into three divided portions 43, 44, 45 in the peripheral direction by the slits 40 and 41.

The first division portion 43 and the third division portion 45 gradually become narrower toward the outer peripheral side (lower side in FIG. 5), and the second division portion 44 has an inner peripheral side (the inner peripheral side (lower side in FIG. 5)). The shape gradually narrows toward the upper side of FIG. 5).

In the portion where the magnetic pole is "N pole" in the rotor core 30, magnetic flux flows through the bridge portion 36 as follows.
As shown by the solid white arrows in FIG. 5, the magnetic flux from the outer peripheral side of the permanent magnet 14 toward the bridge portion 36 is the first division portion having a narrow inlet (specifically, the end portion on the outer peripheral side). It is hardly guided to 43 or the third division 45, and most of it is guided to the second division 44 having a wide entrance.

The width of the entrance of the second division 44 is wide, but the width of the exit (W3 in FIG. 5) is narrow. Specifically, the second division portion 44 has a tapered shape in which the width becomes narrower toward the exit (specifically, the inner peripheral side). Therefore, the magnetic flux density of the second divided portion 44 tends to reach the maximum magnetic flux density at the end on the outlet side where the cross-sectional area is the smallest.

Then, when the maximum magnetic flux density of the iron core material of the second divided portion 44 and the actual magnetic flux density match, the magnetic flux density becomes saturated and the magnetic saturation state is established. Therefore, in this case, the leakage flux can be suppressed.

On the other hand, in the portion of the rotor core 30 where the magnetic pole is the "S pole", magnetic flux flows through the bridge portion 36 as follows.
As shown by the broken white arrow in FIG. 5, the magnetic flux from the inner peripheral side of the permanent magnet 14 toward the bridge portion 36 has a second narrow inlet (specifically, the end on the inner peripheral side). It is hardly guided to the divided portion 44, and most of it is guided to the first divided portion 43 and the third divided portion 45 having a wide entrance.

In these first division portion 43 and third division portion 45, the width of the entrance is wide, but the width of the exit (W4, W5 in FIG. 5) is narrow. Specifically, the first division portion 43 and the third division portion 45 have a tapered shape in which the width becomes narrower toward the outlet (specifically, the outer peripheral side). Therefore, the magnetic flux densities of the first divided portion 43 and the third divided portion 45 tend to reach the maximum magnetic flux density at the end portion on the outlet side having the smallest cross-sectional area.

Then, when the maximum magnetic flux density of the iron core material of the first division portion 43 and the iron core material of the third division portion 45 and the actual magnetic flux density match, the magnetic flux density becomes saturated and the magnetic saturation state is obtained. Therefore, even in this case, the leakage flux can be suppressed.

According to the rotor core 30 of the present embodiment, by providing the two slits 40 and 41, the distance W3 between the ends of the slits 40 and 41 and the end of the first slit 40 and the two insertion holes 13 are provided. The distance W4 from one (left side in FIG. 5) and the distance W5 between the end of the second slit 41 and the other (right side in FIG. 5) of the two insertion holes 13 can be reduced. As a result, a portion having a short distance, that is, a portion having a small cross-sectional area can be formed in each of the divided portions 43, 44, 45 divided by the slits 40, 41 in the bridge portion 36. Therefore, the bridge portion 36 can have a structure in which the magnetic flux does not easily pass through, and the leakage flux can be reduced.

Moreover, in the present embodiment, although the slits 40 and 41 are provided by cutting out a part of the bridge portion 36 in order to reduce the cross-sectional area of the bridge portion 36, the slits 40 and 41 have a cut shape. , The cross-sectional area of the notched part is kept small. As a result, it is possible to suppress a decrease in the cross-sectional area of the entire bridge portion 36, so that it is possible to suppress a decrease in the strength of the bridge portion 36 and, by extension, a decrease in the strength of the rotor core 30.

In the present embodiment, both the slits 40 and 41 extend in a straight line having substantially the same width when the end portion of the iron core portion 11 is viewed in the center line L direction. Therefore, in the cross-sectional areas of the iron core portions 31 in the alignment direction (horizontal direction in FIG. 5) and the center line L direction, the cross-sectional areas of the portions cut out to form the slits 40 and 41 are substantially the same in each radial direction. become. As a result, it is possible to suppress variations in the radial direction regarding the cross-sectional area of the portion cut out of the bridge portion 36 in order to form the slits 40 and 41. Therefore, the shapes of the slits 40 and 41 can be easily set in a manner of ensuring the strength of each portion of the bridge portion 36.

Further, in the present embodiment, both ends of the bridge portion 36 provided with such slits 40 and 41 in the alignment direction, in other words, the ends of the two insertion holes 13 of each magnetic pole on the side close to each other are parallel in the radial direction. It is extending. Therefore, the cross-sectional area of the cross section of the portion of the bridge portion 36 provided with the slits 40, 41 in the alignment direction and the center line L direction can be made substantially the same in each portion in the radial direction.

As described above, according to the present embodiment, the effects described below can be obtained.
(4) When a virtual line VL2 extending in a direction orthogonal to the alignment direction of the two insertion holes 13 in the magnetic pole is drawn while looking at the end of the iron core portion 31 in the center line L direction, the bridge portion 36 is virtual. Two slits 40 and 41 extending in a direction diagonally intersecting the line VL2 are provided. Therefore, the bridge portion 36 can have a structure in which the magnetic flux does not easily pass through, and the leakage flux can be reduced. Moreover, since the slits 40 and 41 have a cut shape, it is possible to suppress a decrease in the cross-sectional area of the entire bridge portion 36, thereby suppressing a decrease in the strength of the bridge portion 36 and eventually a decrease in the strength of the rotor core 30.

(5) The two slits 40 and 41 extend in a straight line having substantially the same width when the end portion of the iron core portion 11 is viewed in the center line L direction. Therefore, the shapes of the slits 40 and 41 can be easily set in a manner of ensuring the strength of each portion of the bridge portion 36.

(6) The two slits 40 and 41 are arranged so as to be plane-symmetrical with a plane extending in the radial direction and the center line L direction of the iron core portion 31 as a plane of symmetry. As a result, the two slits 40 and 41 provided in one bridge portion 36 can have a plane-symmetrical shape in the peripheral direction. Therefore, although the slits 40 and 41 are provided in the bridge portion 36, it is possible to suppress a decrease in the rotational balance of the rotor core 30.

(Other embodiments)
In addition, each of the above-described embodiments may be modified as follows.
-The slit 20 of the first embodiment and the slits 40 and 41 of the second embodiment can have an arbitrary cross-sectional shape such as a rectangular cross-section or an elliptical cross-section.

The cross-sectional shape of the slit 20 of the first embodiment and the cross-sectional shapes of the slits 40 and 41 of the second embodiment are not limited to the linearly extending shape, but may be curved and extended. A shape that bends and extends can be adopted.

-In the second embodiment, the relative positions of the two slits 40 and 41 provided on each magnetic pole can be arbitrarily changed. For example, the distance between the two slits 40 and 41 of each magnetic pole becomes wider toward the inner peripheral side when the end portion of the iron core portion 31 is viewed in the center line L direction. It may be formed so as to have a "shape". In addition, it is also possible to form two slits 40 and 41 of each magnetic pole so that the cross-sectional shapes of the iron core portion 31 when viewed in the L direction of the center line are parallel.

-In each embodiment, three or more slits may be provided in the bridge portion of the iron core portion.
-In each embodiment, the shape of the insertion hole 13 and the shape of the permanent magnet 14 can be arbitrarily changed.

-The rotor core of each of the above embodiments is not limited to a rotor having 10 poles, and can be applied to a rotor having any number of magnetic poles (4 poles, 6 poles, 8 poles, 12 poles, etc.).

10, 30 ... Rotor core, 11, 31 ... Iron core, 12 ... Center hole, 13 ... Insert hole, 14 ... Permanent magnet, 15 ... Filler, 16, 36 ... Bridge part, 20 ... Slit, 21 ... First division part , 22 ... 2nd division, 40 ... 1st slit, 41 ... 2nd slit, 43 ... 1st division, 44 ... 2nd division, 45 ... 3rd division.

Claims (4)

A plurality of insertion holes provided in the core portion having a cylindrical shape, a plurality of insertion holes provided in the core portion so as to penetrate in the direction of the center line of the core portion in such a manner that they are arranged at intervals in the peripheral direction of the iron core portion, and the insertion holes. In the rotor core of a rotating electric machine, which has a permanent magnet fixed in a state of being housed inside the
When a virtual line extending in a direction orthogonal to the arrangement direction of the adjacent insertion holes is drawn while looking at the end of the iron core portion in the center line direction, in the portion sandwiched between the adjacent insertion holes. A rotor core of a rotary electric machine, which has a slit extending in a direction diagonally intersecting the virtual line. The rotor core of the rotary electric machine according to claim 1, wherein the slit extends linearly in a direction in which the slits intersect at an angle. The rotor core of a rotary electric machine according to claim 1 or 2, wherein only one slit is provided in the sandwiched portion. Two slits are provided in the sandwiched portion.
The rotor core of the rotary electric machine according to claim 1 or 2, wherein the two slits are arranged so as to be plane-symmetrical with a plane extending in the radial direction of the iron core portion and the center line direction as symmetric planes.