JP2021112074A - Rotor, rotary electric machine, and manufacturing method of rotor - Google Patents

Abstract

To provide a rotor, a rotary electric machine, and a manufacturing method of the rotor capable of suppressing an eddy current loss of a permanent magnet, suppressing a temperature rise of the permanent magnet, and further reducing a cost.SOLUTION: A rotor 4 includes a rotor core 21 formed by lamination of steel plates, a first magnet insertion hole 27 and second magnet insertion holes 41,42 formed at predetermined intervals in a circumferential direction of the rotor core 21, and a first magnet 23 and a second magnet 24 embedded in the first magnet insertion hole 27 and the second magnet insertion holes 41,42. Welded portions 51 extending in the axial direction of the rotor core 21 are provided on walls of the first magnet insertion hole 27 and the second magnet insertion holes 41,42.SELECTED DRAWING: Figure 5

Description

The present invention relates to a rotor, a rotary electric machine, and a method for manufacturing the rotor.

As a rotary electric machine, for example, a rotor is arranged in a stator, a plurality of magnet insertion holes are formed at predetermined intervals in the circumferential direction of the rotor, permanent magnets are embedded in the plurality of magnet insertion holes, and a plurality of permanent magnets are embedded in the rotor. It is known that a non-magnetic conductor is arranged in a closed circuit. The non-magnetic conductor is arranged in the rotor so that the magnetic flux from the stator interlinks the inside of the closed circuit.
That is, in the non-magnetic conductor, an induced current is generated when the magnetic flux from the stator to the rotor changes. Therefore, it is possible to suppress a change in the magnetic flux passing through the rotor due to the magnetic flux due to the induced current flowing through the non-magnetic conductor. Thereby, the change of the magnetic flux passing through the rotor can be suppressed and the loss can be reduced (see, for example, Patent Document 1).

Further, among the rotary electric machines, those equipped with a split type permanent magnet are known. In the split type permanent magnet, for example, a normal permanent magnet is divided into a plurality of split magnets, and the plurality of split magnets are integrally bonded. By equipping the rotating electric machine with a split type permanent magnet, it is possible to reduce the apparent electrical conductivity and suppress the fluctuation of the magnetic flux flowing into the permanent magnet. Therefore, the eddy current can be suppressed and the eddy current loss of the permanent magnet can be suppressed. Further, by suppressing the eddy current loss of the permanent magnet, it is possible to suppress the temperature rise of the permanent magnet.

Japanese Unexamined Patent Publication No. 2019-126143

However, in the split type permanent magnet, for example, it is necessary to divide the permanent magnet into a plurality of split magnets and bond the split plurality of split magnets integrally, which hinders cost reduction.

An object of the present invention is to provide a rotor, a rotary electric machine, and a method for manufacturing a rotor, which can suppress the eddy current loss of a permanent magnet, suppress the temperature rise of the permanent magnet, and further suppress the cost.

In order to solve the above problems, the rotor, the rotary electric machine, and the method for manufacturing the rotor of the present invention have adopted the following configurations.
(1) The rotor (for example, rotors 4 and 100 in the embodiment) includes a rotor core (for example, a rotor core 21 in the embodiment) formed by laminating steel plates (for example, an electromagnetic steel plate 9 in the embodiment) and the rotor core. A plurality of magnet insertion holes (for example, a first magnet insertion hole 27 and a pair of second magnet insertion holes 41, 42 in the embodiment) formed at predetermined intervals in the circumferential direction of the above, and embedded in the plurality of magnet insertion holes. Permanent magnets (for example, the first magnet 23 and the second magnet 24 in the embodiment) are provided, and a welded portion extending in the axial direction of the rotor core (for example, welding in the embodiment) is provided on the wall surface of the magnet insertion hole. Part 51) is provided.

According to this configuration, by providing a welded portion extending in the axial direction of the rotor core on the wall surface of the magnet insertion hole of the rotor core, the laminated steel plates can be electrically connected to each other at the welded portion. As a result, a current path (closed circuit) can be formed by the welded portion and the steel plate.
By the way, for example, in a rotary electric machine, a rotor is rotated by supplying an alternating current to each coil from an inverter (not shown) controlled by PWM (Pulse Width Modulation). In this rotary electric machine, harmonic components corresponding to the switching frequency and the like are superimposed on the current applied to each coil from the inverter. Therefore, the magnetic flux (magnetic flux density) from the stator to the rotor changes.

An induced current is generated at the weld due to the change in the magnetic flux from the stator to the rotor. Therefore, it is possible to suppress fluctuations in the magnetic flux passing through the rotor due to the magnetic flux due to the induced current flowing through the welded portion. Here, the magnetic flux due to the induced current flowing through the weld cancels only the fluctuating magnetic flux among the magnetic fluxes flowing through the permanent magnet, and does not affect the magnetic flux that does not fluctuate. Therefore, the fluctuation of the magnetic flux flowing through the permanent magnet can be suppressed. As a result, the eddy current can be suppressed and the eddy current loss of the permanent magnet can be suppressed. Further, by suppressing the eddy current loss of the permanent magnet, it is possible to suppress the temperature rise of the permanent magnet.

In addition, a current path (closed circuit) is formed in the welded portion and the steel plate so that the fluctuation of the magnetic flux passing through the permanent magnet is suppressed by the magnetic flux due to the induced current flowing through the welded portion. Therefore, it is possible to suppress the eddy current, suppress the eddy current loss of the permanent magnet, and suppress the temperature rise of the permanent magnet without dividing the permanent magnet. As a result, the cost of the permanent magnet (that is, the rotor) can be suppressed.
Further, the wall surface of the magnet insertion hole is provided with a welded portion extending in the axial direction of the rotor core, so that the steel plates are held in a laminated state. As a result, it is not necessary to crimp the steel plates to each other, so that the rotor core can be formed with a simple configuration, and the cost of the rotary electric machine can be further suppressed.
In addition, by suppressing the eddy current loss of the permanent magnet and suppressing the temperature rise of the permanent magnet, a permanent magnet having a low coercive force can be used.

(2) At least a pair of the welded portions may be provided side by side in the circumferential direction.

According to this configuration, at least a pair of welded portions are provided side by side in the circumferential direction. Therefore, the magnetic flux from the stator to the rotor can be interlinked perpendicularly to the current path (closed circuit) formed by the pair of welds and the steel plate.
Here, for example, when the magnetic flux is interlinked perpendicularly to the closed circuit, the density of the interlinkage magnetic flux amount in the closed circuit becomes larger than that in the case where the magnetic flux is interlinked obliquely with respect to the closed circuit. Further, when the density of the amount of interlinkage magnetic flux in the closed circuit is increased, the induced current flowing in the closed circuit can be increased. The induced current suppresses the fluctuation of the magnetic flux of the permanent magnet.
As a result, by interlinking the magnetic flux perpendicularly to the closed circuit, the induced current flowing through the closed circuit can be increased, and the fluctuation of the magnetic flux of the permanent magnet can be suitably suppressed.

(3) The magnet insertion holes include a magnet insertion portion (for example, the first magnet insertion portion 36 and the second magnet insertion portion 43 and 46 in the embodiment) and a flux barrier (for example, the first flux barrier 37 and the first flux barrier 37 in the embodiment). 2 Outer flux barriers 45, 48), and the welded portion may be provided on the flux barrier.

According to this configuration, the magnet insertion hole is formed by the magnet insertion portion and the flux barrier. A welded part was provided on the flux barrier. Therefore, it is not necessary to form a dedicated weld hole in order to provide the welded portion on the rotor core. As a result, it is possible to suppress the fluctuation of the magnetic flux passing through the permanent magnet with a simple configuration of adding a welded portion.

(4) A pair of end face plates (for example, end face plates 26 in the embodiment) are provided on the axial end face (for example, the outer end face 21a in the embodiment) of the rotor core, and the flux barrier is provided for cooling provided on the end face plate. It may communicate with the medium passage (for example, the second cooling medium passage 58 in the embodiment).

According to this configuration, a pair of end face plates are provided on the axial end faces of the rotor core, and the flux barrier is communicated with the cooling medium passage provided on the end face plates. Therefore, the refrigerant flowing through the cooling medium passage can be guided to the flux barrier. As a result, the temperature rise of the welded portion can be suppressed by the refrigerant, and the permanent magnet can be further cooled.

(5) The welded portion may be provided on the outer peripheral side of the rotor core with respect to the permanent magnet.

According to this configuration, the welded portion is provided on the outer peripheral side of the rotor with respect to the permanent magnet. Therefore, a large distance (pitch) in the circumferential direction of the welded portion can be secured.
Here, for example, the distance in the circumferential direction of the welded portion is proportional to the amount of interlinkage magnetic flux interlinking with the welded portion. Further, when the amount of interlinkage magnetic flux increases, the induced current flowing through the welded portion can be increased. The induced current suppresses the fluctuation of the magnetic flux of the permanent magnet.
As a result, by securing a large distance in the circumferential direction of the welded portion, the induced current flowing through the welded portion can be increased, and the fluctuation of the magnetic flux of the permanent magnet can be suitably suppressed.

Further, by providing the welded portion on the outer peripheral side of the rotor with respect to the permanent magnet, only the fluctuating magnetic flux flowing through the outer peripheral end of the rotor (that is, both ends of the permanent magnet) of the permanent magnet is induced to flow through the welded portion. It can be suppressed by the magnetic flux generated by the current. As a result, it is possible to prevent the magnetic flux that does not fluctuate due to the magnetic flux due to the induced current from being affected, and it is possible to efficiently suppress the fluctuation of the magnetic flux flowing through the permanent magnet.

(6) The welded portion may be provided so as to be symmetrical about the d-axis (for example, the d-axis Vd in the embodiment).

According to this configuration, the welded portions are provided so as to be symmetrical about the d-axis. The d-axis corresponds to, for example, a virtual straight line that passes through the axis of the rotor and passes through the center of the magnetic pole when viewed from the axial direction of the rotor. As a result, the amount of interlinkage magnetic flux can be made uniform for each magnetic pole, and the degree of cooling can be made uniform (same) for each magnetic pole.

(7) The welded portion may connect the steel plate at one end in the axial direction and the steel plate at the other end in the axial direction.

According to this configuration, the steel plate at one end in the axial direction and the steel plate at the other end in the axial direction are connected by the welded portion. Therefore, a current path (closed circuit) is formed between the welded portion, the steel plate at one end in the axial direction, and the steel plate at the other end in the axial direction, and a large axial separation distance between the steel plates forming the closed circuit can be secured.
Here, for example, the axial separation distance of the steel sheet is proportional to the amount of interlinkage magnetic flux interlinking the closed circuit. Further, when the amount of interlinkage magnetic flux increases, the induced current flowing through the closed circuit can be increased. The induced current suppresses the fluctuation of the magnetic flux of the permanent magnet.
As a result, by ensuring a large axial separation distance of the steel sheet, the induced current flowing in the closed circuit can be increased, and the fluctuation of the magnetic flux of the permanent magnet can be suitably suppressed.

(8) The rotary electric machine includes the rotor and a stator (for example, the stator 3 in the embodiment) arranged outside the rotor at intervals.

According to this configuration, it is possible to provide a rotary electric machine capable of suppressing the eddy current loss of the permanent magnet, suppressing the temperature rise of the permanent magnet, and further suppressing the cost.

(9) A method for manufacturing a rotor (for example, rotors 4 and 100 in the embodiment) is a method of manufacturing a rotor core (for example, a rotor core 21 in the embodiment) formed by laminating steel plates (for example, an electromagnetic steel plate 9 in the embodiment). A plurality of magnet insertion holes (for example, a first magnet insertion hole 27 and a pair of second magnet insertion holes 41, 42 in the embodiment) formed at predetermined intervals in the circumferential direction of the rotor core, and the plurality of magnet insertion holes. A method for manufacturing a rotor including a permanent magnet (for example, a first magnet 23 and a second magnet 24 in the embodiment) embedded in a hole, which comprises a laminating step of laminating the steel plates to form the rotor core. A welding step of welding the wall surface of the magnet insertion hole along the axial direction of the rotor core and an embedding step of embedding the permanent magnet in the magnet insertion hole are provided.

According to this configuration, the method of manufacturing the rotor includes a welding step of welding the wall surface of the magnet insertion hole along the axial direction of the rotor core. Therefore, the welded portion is provided on the wall surface of the magnet insertion hole. The weld extends axially along the rotor core. Therefore, the laminated steel plates can be electrically connected to each other at the welded portion. As a result, a current path (closed circuit) can be formed by the welded portion and the steel plate. Therefore, the eddy current can be suppressed and the eddy current loss of the permanent magnet can be suppressed. Further, by suppressing the eddy current loss of the permanent magnet, it is possible to suppress the temperature rise of the permanent magnet.

In addition, a current path (closed circuit) was formed in the welded portion and the steel plate. Therefore, it is possible to suppress the eddy current, suppress the eddy current loss of the permanent magnet, and suppress the temperature rise of the permanent magnet without dividing the permanent magnet. As a result, the cost of the permanent magnet (that is, the rotor) can be suppressed.
Further, since the wall surface of the magnet insertion hole is provided with a welded portion, the steel plates are held in a laminated state. As a result, it is not necessary to crimp the steel plates to each other, so that the rotor core can be formed with a simple configuration, and the cost of the rotary electric machine can be further reduced.
In addition, by suppressing the eddy current loss of the permanent magnet and suppressing the temperature rise of the permanent magnet, a permanent magnet having a low coercive force can be used.
From the above, it is possible to provide a rotor manufacturing method capable of suppressing the eddy current loss of the permanent magnet, suppressing the temperature rise of the permanent magnet, and further suppressing the cost.

(10) The laminating step includes a first laminating step of forming a plurality of rotor core pieces (for example, rotor core pieces 22 in the embodiment) in which the rotor core is divided in the axial direction, and a first laminating step of laminating the plurality of rotor core pieces. The two laminating steps may be provided.

According to this configuration, the laminating step includes a first laminating step of forming a plurality of rotor core pieces in which the rotor core is axially divided, and a second laminating step of laminating a plurality of rotor core pieces. Therefore, after forming the rotor core pieces, the rotor core pieces can be laminated to form the rotor core.
For example, when forming a rotor core that is long in the axial direction, it becomes difficult to weld the wall surface of the magnet insertion hole along the axial direction.
On the other hand, since the present invention includes a first laminating step of forming a plurality of rotor core pieces and a second laminating step of laminating a plurality of rotor core pieces, each rotor core piece divided in the axial direction is provided. Welding process can be performed. As a result, even when a rotor core long in the axial direction is formed, the wall surface of the magnet insertion hole can be easily welded along the axial direction.
Therefore, the operator can arbitrarily select the timing of the welding step after the first laminating step or after the second laminating step, depending on the axial length of the rotor core. Thereby, it is possible to provide a method for manufacturing a rotor with improved biotechnique.

According to the present invention, the eddy current loss of the permanent magnet can be suppressed, the temperature rise of the permanent magnet can be suppressed, and the cost can be suppressed.

It is a schematic block diagram which shows the rotary electric machine of 1st Embodiment which concerns on this invention. It is sectional drawing along the line II-II of FIG. It is a perspective view which shows the rotor of 1st Embodiment. It is an exploded perspective view which shows the rotor of 1st Embodiment. FIG. 5 is an enlarged cross-sectional view of the V portion of FIG. It is an enlarged perspective view of the VI part of FIG. It is a perspective view which shows the rotor of 1st Embodiment. It is sectional drawing which shows the rotor of 1st Embodiment. It is sectional drawing which follows the IX-IX line of FIG. It is a graph which shows the magnetic flux fluctuation of the rotary electric machine of 1st Embodiment. It is a schematic diagram which shows the welding process in the manufacturing method of the rotor of 1st Embodiment. It is sectional drawing which shows the rotor of the 2nd Embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, a rotary electric machine (that is, a traveling motor) mounted on a vehicle such as a hybrid vehicle or an electric vehicle will be described.

[First Embodiment]
<Rotating machine>
FIG. 1 is a schematic configuration diagram showing a rotary electric machine 1 of the first embodiment. FIG. 1 is a diagram including a cross section cut by a virtual plane including the axis C.
As shown in FIG. 1, the rotary electric machine 1 includes a case 2, a stator 3, a rotor 4, and a shaft 5.

The case 2 has a tubular box shape for accommodating the stator 3 and the rotor 4. A refrigerant (not shown) is housed in the case 2. A part of the stator 3 is immersed in the refrigerant in the case 2. For example, as the refrigerant, ATF (Automatic Transmission Fluid) or the like, which is a hydraulic oil used for lubrication of a transmission, power transmission, or the like, is used.
The shaft 5 is rotatably supported by the case 2. In FIG. 1, reference numeral 6 indicates a bearing that rotatably supports the shaft 5. Hereinafter, the direction along the axis C of the shaft 5 is referred to as the “axial direction”, the direction orthogonal to the axis C is referred to as the “diameter direction”, and the direction around the axis C is referred to as the “circumferential direction”.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.
As shown in FIGS. 1 and 2, the stator 3 includes a stator core 11 and a plurality of layers (for example, U phase, V phase, W phase) coils 12 mounted on the stator core 11.
The stator core 11 has an annular shape arranged coaxially with the axis C. The stator core 11 is fixed to the inner peripheral surface of the case 2. For example, the stator core 11 is formed by laminating a plurality of electromagnetic steel plates (steel plates) 9 in the axial direction. The stator core 11 may be a so-called compaction core obtained by compression molding a metal magnetic powder (soft magnetic powder).

The stator core 11 has a slot 13 into which the coil 12 is inserted. A plurality of slots 13 are arranged at intervals in the circumferential direction. The coil 12 includes an insertion portion 12a inserted into the slot 13 of the stator core 11 and a coil end portion 12b protruding axially from the stator core 11. The stator core 11 generates a magnetic field when a current flows through the coil 12.

<Rotor>
FIG. 3 is a perspective view showing the rotor 4 of the first embodiment.
As shown in FIGS. 1 and 3, the rotors 4 are arranged at intervals inside the stator 3 in the radial direction. The rotor 4 is fixed to the shaft 5. The rotor 4 is configured to be rotatable around the axis C integrally with the shaft 5. The rotor 4 includes a rotor core 21, a first magnet 23 and a second magnet 24 (see FIG. 2), and an end face plate 26. The first magnet 23 and the second magnet 24 are, for example, permanent magnets.

The rotor core 21 has an annular shape arranged coaxially with the axis C. The rotor core 21 has a shaft fixing hole 8 in which the shaft 5 is press-fitted and fixed inside in the radial direction. The rotor core 21 is formed by laminating a plurality of electromagnetic steel sheets 9 (see FIG. 2) in the axial direction.

FIG. 4 is an exploded perspective view showing the rotor 4 of the first embodiment.
As shown in FIGS. 1 and 4, the pair of end face plates 26 are provided in a state of being in contact with both outer end faces (axial end faces) 21a in the axial direction with respect to the rotor core 21. The end face plate 26 covers a plurality of first magnet insertion holes 27 and a plurality of second magnet insertion hole groups 28 in the rotor core 21 from both ends in the axial direction.

The rotor core 21 has a plurality of first magnet insertion holes (magnet insertion holes) 27 and a plurality of second magnet insertion holes 28 that penetrate the rotor core 21 in the axial direction. The first magnet insertion hole 27 and the second magnet insertion hole group 28 are arranged side by side in the radial direction in the rotor core 21, and a plurality of the first magnet insertion holes 27 and the second magnet insertion hole group 28 are formed at predetermined intervals in the circumferential direction.
In the rotor 4, the electromagnetic steel plate 9 of the rotor core 21 is formed of a magnetic material, and the first magnet 23 and the second magnet are inserted into the two first magnet insertion holes 27 and the second magnet insertion hole group 28 arranged in the radial direction. Two magnets 24 form a set to form one magnetic pole portion (magnetic pole) 31. That is, the rotary electric machine 1 is a permanent magnet embedded rotary electric machine (IPM (Interior Permanent Magnet) motor) in which the first magnet 23 and the second magnet 24 are embedded in the first magnet insertion hole 27 and the second magnet insertion hole group 28. It is a rotor of.

FIG. 5 is an enlarged cross-sectional view of the V portion of FIG.
As shown in FIGS. 4 and 5, the plurality of first magnet insertion holes 27 are arranged at intervals in the circumferential direction on the outer peripheral portion of the rotor core 21. However, in FIGS. 4 and 5, only one first magnet insertion hole 27 is shown. The first magnet insertion hole 27 is formed symmetrically in the circumferential direction with the d-axis Vd, which will be described later, as the center when viewed from the axial direction. Specifically, the first magnet insertion hole 27 is formed to be convexly curved toward the shaft 5 (see FIG. 1), and both ends of the curved longitudinal direction extend to the vicinity of the outer circumference 21b of the rotor core 21.

The first magnet insertion hole 27 has a first magnet insertion portion (magnet insertion portion) 36 and a pair of first flux barriers (flux barriers) 37. The first magnet insertion portion 36 is located at the center of the first magnet insertion hole 27 in the longitudinal direction. The first flux barrier 37 extends from both ends of the first magnet insertion portion 36 to the vicinity of the outer circumference 21b of the rotor core 21. The outer end 37a of the first flux barrier 37 extends to the vicinity of the outer circumference 21b of the rotor core 21.

The first magnet 23 is inserted into the first magnet insertion portion 36. The first magnet 23 is inserted so that the magnetic poles are alternately inverted in the circumferential direction. For example, assuming that the outer peripheral side of the magnetic pole portion 31 is N pole, the first magnet 23 is inserted into the first magnet insertion hole 27 (first magnet insertion portion 36) so that the outer peripheral side of the adjacent magnetic pole portion is S pole. Has been done.

The plurality of second magnet insertion holes 28 are formed at positions corresponding to the plurality of first magnet insertion holes 27 in the radial direction. The second magnet insertion hole group 28 has a pair of second magnet insertion holes (magnet insertion holes) 41 and 42. The pair of second magnet insertion holes 41, 42 are formed symmetrically in the circumferential direction with the d-axis Vd, which will be described later, as the center when viewed from the axial direction. Specifically, the pair of second magnet insertion holes 41 and 42 are arranged so as to form a convex V-shape toward the shaft 5 (see FIG. 1). The pair of second magnet insertion holes 41, 42 are formed in a curved shape at positions adjacent to each other in the circumferential direction, and the outer end portion extends to the vicinity of the outer circumference 21b of the rotor core 21.

One of the second magnet insertion holes 41 has a second magnet insertion portion (magnet insertion portion) 43, a second inner flux barrier 44, and a second outer flux barrier (flux barrier) 45. The second magnet insertion portion 43 is located at the center of one of the second magnet insertion holes 41 in the longitudinal direction. The second inner flux barrier 44 extends from the radial inner end of the second magnet insertion portion 43 toward the shaft 5 (see FIG. 1). Further, the second outer flux barrier 45 extends from the radial outer end of the second magnet insertion portion 43 to the vicinity of the outer circumference 21b of the rotor core 21.

The other second magnet insertion hole 42 has a second magnet insertion portion (magnet insertion portion) 46, a second inner flux barrier 47, and a second outer flux barrier (flux barrier) 48. The second magnet insertion portion 46 is located at the center of the other second magnet insertion hole 42 in the longitudinal direction. The second inner flux barrier 47 extends from the radial inner end of the second magnet insertion portion 46 toward the shaft 5 (see FIG. 1). Further, the second outer flux barrier 48 extends from the radial outer end of the second magnet insertion portion 46 to the vicinity of the outer circumference 21b of the rotor core 21.

The second magnet 24 is inserted into one second magnet insertion portion 43 and the other second magnet insertion portion 46. Similar to the first magnet 23, the pair of second magnets 24 are inserted so that the magnetic poles are alternately inverted in the circumferential direction. For example, assuming that the outer peripheral side of the magnetic pole portion 31 has an N pole, the adjacent magnetic pole portions have a pair of second magnets 24 having one second magnet insertion portion 43 and the other second magnet so that the outer peripheral side thereof has an S pole. It is inserted into the insertion portion 46.

Here, the arrow Vd indicates the d-axis direction of the magnetic pole portion 31 composed of the first magnet 23 and the pair of second magnets 24. The d-axis Vd corresponds to a virtual straight line (that is, a virtual straight line passing through the center of the magnetic pole) that passes through the axis C and bisects between a pair of V-shaped second magnets 24 when viewed from the axial direction. do.

FIG. 6 is an enlarged perspective view of the VI portion of FIG.
As shown in FIGS. 3, 5, and 6, a welded portion 51 extending in the axial direction of the rotor core 21 is provided on the wall surface of the first magnet insertion hole 27. Of the pair of first flux barriers 37, a welded portion 51 is provided on the vicinity side of the outer circumference 21b of the rotor core 21. The welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the first magnet 23.

Further, a welded portion 51 extending in the axial direction of the rotor core 21 is provided on the wall surface of one of the second magnet insertion holes 41. Of the second outer flux barrier 45, the welded portion 51 is provided on the vicinity side of the outer circumference 21b of the rotor core 21. One welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the one second magnet 24. Further, a welded portion 51 extending in the axial direction of the rotor core 21 is provided on the wall surface of the other second magnet insertion hole 42. Of the other second outer flux barrier 48, a welded portion 51 is provided on the vicinity side of the outer circumference 21b of the rotor core 21. The other welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the other second magnet 24.

That is, a pair of welded portions 51 are provided on the pair of first flux barriers 37 side by side in the circumferential direction. A pair of welded portions 51 are provided on the pair of second outer flux barriers 45 and 48 side by side in the circumferential direction. The welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the first magnet 23. The welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the second magnet 24.

FIG. 7 is a perspective view showing the rotor 4 of the first embodiment.
As shown in FIG. 7, the welded portion 51 connects the electromagnetic steel sheets 9 laminated in the axial direction to each other. The current path (closed circuit 7) is formed by a welded portion 51 and a pair of electromagnetic steel sheets 9 connected by the welded portion 51. The welded portion 51 connects the electromagnetic steel sheet 9 at one end in the axial direction and the electrical steel sheet 9 at the other end in the axial direction. The current path (closed circuit 7) is formed by a welded portion 51, an electromagnetic steel plate 9 at one end in the axial direction, and an electromagnetic steel plate 9 at the other end in the axial direction.

FIG. 8 is a cross-sectional view showing the rotor 4 of the first embodiment. FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG.
As shown in FIGS. 8 and 9, the end face plate 26 has a plurality of first cooling medium passages 57 and a second cooling medium passage 58.
The plurality of first cooling medium passages 57 are second cooled from the inner peripheral surface 26b of the end face plate 26 inside the end face plate 26 along a line extending radially from the axis C toward the outer peripheral surface 26a of the end face plate 26. It extends to the medium passage 58. In the first cooling medium passage 57, the inner end portion 57a is opened to the inner peripheral surface 26b of the end face plate 26, and the outer end portion 57b is opened to the second cooling medium passage 58. The inner end portion 57a of the first cooling medium passage 57 communicates with the cooling medium passage (not shown) of the shaft 5.

The second cooling medium passage 58 is formed in an annular shape along the outer peripheral surface 26a in the vicinity of the inside of the outer peripheral surface 26a of the end face plate 26 in the inside of the end face plate 26. The outer end portion 57b of the first cooling medium passage 57 communicates with the second cooling medium passage 58. That is, the second cooling medium passage 58 communicates with the cooling medium passage of the shaft 5 (see FIG. 1) via the first cooling medium passage 57. As shown in FIG. 4, the second cooling medium passage 58 has a plurality of communication holes 58a. The communication holes 58a are formed at positions corresponding to the first flux barrier 37 and the second outer flux barriers 45 and 48. The communication hole 58a opens toward the rotor core 21. The second cooling medium passage 58 communicates with the first flux barrier 37 and the second outer flux barriers 45 and 48 through the communication holes 58a.

Returning to FIG. 5, among the plurality of welded portions 51, the pair of welded portions 51 provided on the pair of first flux barriers 37 are provided symmetrically in the circumferential direction with the d-axis Vd as the center when viewed from the axial direction. Has been done. Further, among the plurality of welded portions 51, the pair of welded portions 51 provided on the pair of second outer flux barriers 45 and 48 are provided symmetrically in the circumferential direction with the d-axis Vd as the center when viewed from the axial direction. ing.

Next, the inflow magnetic flux analysis result will be described with reference to FIG.
FIG. 10 is a graph showing the magnetic flux fluctuation of the rotary electric machine 1 of the first embodiment.
In FIG. 10, the vertical axis shows the fluctuation of the magnetic flux flowing into the surfaces of the first magnet 23 and the second magnet 24. The horizontal axis indicates the electric angle. Further, the solid line graph G1 shows the magnetic flux fluctuation of the rotary electric machine 1 of the first embodiment in which the welded portions 51 are provided on the pair of the first flux barrier 37 and the pair of the second outer flux barriers 45 and 48. The broken line graph G2 shows the magnetic flux fluctuation of the rotating electric machine of the comparative example in which the pair of first flux barriers 37 and the pair of second outer flux barriers 45 and 48 are not provided with the welded portions 51.
As shown in the graphs G1 and G2 of FIG. 10, the rotary electric machine 1 of the first embodiment can suppress the magnetic flux fluctuation as compared with the rotary electric machine of the comparative example.

That is, according to the rotary electric machine 1 of the first embodiment, the welded portion 51 and the welded portion 51 and the pair of electromagnetic steel plates 9 connected by the welded portion 51 form a current path (closed circuit 7). An induced current can be passed through the closed circuit 7. The magnetic flux due to the induced current flowing through the welded portion 51 and the closed circuit 7 can cancel only the fluctuating magnetic flux among the magnetic fluxes flowing through the first magnet 23 and the second magnet 24. Therefore, the fluctuation of the magnetic flux flowing through the first magnet 23 and the second magnet 24 can be suppressed. As a result, the eddy current can be suppressed and the eddy current loss of the first magnet 23 and the second magnet 24 can be suppressed.

<Rotor manufacturing method>
FIG. 11 is a schematic view showing a welding process in the method for manufacturing the rotor 4 of the first embodiment.
Hereinafter, the manufacturing method of the rotor 4 will be described with reference to FIGS. 5, 7, and 11.
The method for manufacturing the rotor 4 includes a laminating step, a welding step, and an embedding step.
<Laminating process>
As shown in FIG. 7, in the laminating step, the electromagnetic steel sheets 9 are laminated to form the rotor core 21. The laminating step includes a first laminating step and a second laminating step. In this manufacturing method, a welding step is performed between the first laminating step and the second laminating step.
<First laminating process>
In the first laminating step, the electromagnetic steel sheets 9 are laminated to form three rotor core pieces 22. The rotor core piece 22 is obtained by dividing the rotor core 21 in the axial direction. In the present embodiment, the number of rotor core pieces 22 is set to 3, but the number is not limited to 3.

<Welding process>
As shown in FIG. 11, in the welding process, the laser oscillator 60 first emits laser light A toward the rotor core piece 22. A device composed of a mirror 61, a lens 62, and the like is provided between the laser oscillator 60 and the rotor core piece 22. The emitted laser light A is sent to the lens 62 by the mirror 61 and passes through the lens 62. When the laser beam A passes through the lens 62, it irradiates the first magnet insertion hole 27 of the rotor core piece 22. Specifically, the laser beam A irradiates the wall surfaces of the pair of first flux barriers 37 in the first magnet insertion holes 27. As a result, the wall surfaces of the pair of first flux barriers 37 in the first magnet insertion holes 27 are welded along the axial direction of the rotor core 21. As a result, the pair of welded portions 51 are formed on the pair of first flux barriers 37.
Similarly, the walls of the pair of second outer flux barriers 45, 48 (see FIG. 5) in the pair of second magnet insertion holes 41, 42 (see FIG. 5) are welded along the axial direction of the rotor core 21. .. As a result, the pair of welded portions 51 are formed on the wall surfaces of the pair of second outer flux barriers 45 and 48.
In the present embodiment, the welding step is performed on each rotor core piece 22 after the first laminating step, but it may be performed after the second laminating step.
<Second laminating process>
As shown in FIG. 7, in the second laminating step, three rotor core pieces 22 are laminated to form the rotor core 21.
<Embedding process>
As shown in FIG. 5, in the embedding step, the first magnet 23 is embedded in the first magnet insertion portion 36 of the first magnet insertion hole 27. The pair of second magnets 24 are embedded in the pair of second magnet insertion portions 43, 46 in the pair of second magnet insertion holes 41, 42. As a result, the rotor 4 is manufactured.

As described above, in the rotor 4 of the first embodiment, welded portions 51 extending in the axial direction of the rotor core 21 are provided on the wall surfaces of the first magnet insertion holes 27 and the second magnet insertion holes 41 and 42 of the rotor core 21. Has been done.
According to this configuration, the laminated electromagnetic steel sheets 9 are laminated by providing the welded portions 51 extending in the axial direction of the rotor core 21 on the wall surfaces of the first magnet insertion holes 27 and the second magnet insertion holes 41 and 42 of the rotor core 21. It can be conducted at the welded portion 51. As a result, a current path (closed circuit 7) can be formed by the welded portion 51 and the electromagnetic steel plate 9.

By the way, for example, in the rotary electric machine 1, the rotor 4 rotates by supplying an alternating current to each coil 12 from an inverter (not shown) controlled by PWM (Pulse Width Modulation). In this rotary electric machine 1, a harmonic component corresponding to a switching frequency or the like is superimposed on a current applied to each coil 12 from an inverter. Therefore, the magnetic flux (magnetic flux density) from the stator 3 to the rotor 4 changes.
An induced current is generated at the welded portion 51 by changing the magnetic flux from the stator 3 to the rotor 4. Therefore, the fluctuation of the magnetic flux passing through the rotor 4 can be suppressed by the magnetic flux due to the induced current flowing through the welded portion 51.

Here, the magnetic flux due to the induced current flowing through the welded portion 51 cancels only the fluctuating magnetic flux among the magnetic fluxes flowing through the first magnet 23 and the second magnet 24, and does not affect the magnetic flux that does not fluctuate. Therefore, the fluctuation of the magnetic flux flowing through the first magnet 23 and the second magnet 24 can be suppressed. As a result, the eddy current can be suppressed and the eddy current loss of the first magnet 23 and the second magnet 24 can be suppressed. Further, by suppressing the eddy current loss of the first magnet 23 and the second magnet 24, it is possible to suppress the temperature rise of the first magnet 23 and the second magnet 24.

Further, a current path (closed circuit 7) is formed by the welded portion 51 and the electromagnetic steel plate 9, and fluctuations in the magnetic flux passing through the first magnet 23 and the second magnet 24 are suppressed by the magnetic flux due to the induced current flowing through the welded portion 51. I did. Therefore, without dividing the first magnet 23 and the second magnet 24, the eddy current is suppressed to suppress the eddy current loss of the first magnet 23 and the second magnet 24, and the first magnet 23 and the second magnet 24 It is possible to suppress the temperature rise. Thereby, the cost of the first magnet 23 and the second magnet 24 (that is, the rotor 4) can be suppressed.

Further, the wall surfaces of the first magnet insertion holes 27 and the second magnet insertion holes 41 and 42 are provided with welded portions 51 extending in the axial direction of the rotor core 21, so that the electromagnetic steel sheets 9 are laminated with each other. Be retained. As a result, it is not necessary to crimp the electromagnetic steel sheets 9 to each other, so that the rotor core 21 can be formed with a simple configuration, and the cost of the rotary electric machine 1 can be further suppressed.
In addition, by suppressing the eddy current loss of the first magnet 23 and the second magnet 24 and suppressing the temperature rise of the first magnet 23 and the second magnet 24, the first magnet 23 and the second magnet having a low coercive force are suppressed. A magnet 24 can be used.

Further, at least a pair of welded portions 51 are provided side by side in the circumferential direction. Therefore, the magnetic flux from the stator 3 to the rotor 4 can be interlinked perpendicularly to the current path (closed circuit 7) formed by the pair of welded portions 51 and the electromagnetic steel plate 9.
Here, for example, when the magnetic flux is interlinked perpendicularly to the closed circuit 7, the density of the interlinkage magnetic flux amount in the closed circuit 7 is larger than that in the case where the magnetic flux is obliquely interlocked with respect to the closed circuit 7. Become. Further, when the density of the amount of interlinkage magnetic flux in the closed circuit 7 becomes large, the induced current flowing through the closed circuit 7 can be increased. The induced current suppresses the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24.
As a result, by interlinking the magnetic flux perpendicularly to the closed circuit 7, the induced current flowing through the closed circuit 7 can be increased, and the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24 can be suitably suppressed.

Further, the pair of first flux barriers 37 and the pair of second outer flux barriers 45 and 48 are provided with welded portions 51. Therefore, in order to provide the welded portion 51 in the rotor core 21, it is not necessary to form a dedicated weld hole in the rotor core 21. As a result, the fluctuation of the magnetic flux passing through the first magnet 23 and the second magnet 24 can be suppressed by a simple configuration in which the welded portion 51 is simply added.

Further, the first flux barrier 37 and the second outer flux barriers 45 and 48 communicate with the cooling medium passage of the shaft 5 via the plurality of first cooling medium passages 57 and the pair of second cooling medium passages 58. Therefore, the refrigerant (for example, ATF) flowing through the cooling medium passage of the shaft 5 is passed through the plurality of first cooling medium passages 57 and the pair of second cooling medium passages 58 by the centrifugal force of the rotor 4, and the first flux barrier 37 and the first flux barrier 37. It can be led to the second outer flux barriers 45, 48. As a result, the temperature rise of the welded portion 51 can be suppressed by the refrigerant, and the first magnet 23 and the second magnet 24 can be further cooled.

In addition, the welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the first magnet 23. Therefore, the distance (pitch) L1 (see FIG. 5) in the circumferential direction of the pair of welded portions 51 provided on the outer peripheral surface 21b side of the rotor core 21 is larger than that of the first magnet 23.
Further, the welded portion 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the second magnet 24. Therefore, the distance (pitch) L2 (see FIG. 5) in the circumferential direction of the pair of welded portions 51 provided on the outer peripheral surface 21b side of the rotor core 21 is larger than that of the second magnet 24.

Here, for example, the distances L1 and L2 in the circumferential direction of the welded portion 51 are proportional to the amount of interlinkage magnetic flux interlinking with the welded portion 51. Further, when the amount of interlinkage magnetic flux increases, the induced current flowing through the welded portion 51 can be increased. The induced current suppresses the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24. As a result, by securing a large distance L1 and L2 in the circumferential direction of the welded portion 51, the induced current flowing through the welded portion 51 can be increased, and the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24 can be suitably suppressed.

Further, the welded portion 51 is provided on the outer peripheral surface 21b side of the rotor 4 with respect to the first magnet 23 and the second magnet 24. Therefore, of the first magnet 23 and the second magnet 24, only the fluctuating magnetic flux flowing through the ends of the rotor 4 on the outer peripheral surface 21b side (that is, both ends of the first magnet 23 and the second magnet 24) flows through the welded portion 51. It can be suppressed by the magnetic flux due to the induced current. As a result, it is possible to prevent the magnetic flux that does not fluctuate due to the magnetic flux due to the induced current from being affected, and it is possible to efficiently suppress the fluctuation of the magnetic flux flowing through the first magnet 23 and the second magnet 24.

Further, the pair of welded portions 51 provided on the pair of first flux barriers 37 are provided symmetrically in the circumferential direction with the d-axis Vd as the center. Further, the pair of welded portions 51 provided on the pair of second outer flux barriers 45 and 48 are provided symmetrically in the circumferential direction with the d-axis Vd as the center. As a result, the amount of interlinkage magnetic flux can be made uniform for each magnetic pole portion 31, and the degree of cooling can be made uniform (same) for each magnetic pole portion 31.

Further, the welded portion 51 connects the electromagnetic steel plate 9 at one end in the axial direction and the electromagnetic steel plate 9 at the other end in the axial direction. Therefore, the welded portion 51, the electromagnetic steel sheet 9 at one end in the axial direction, and the electrical steel sheet 9 at the other end in the axial direction form a current path (closed circuit 7), and the electromagnetic steel sheet 9 forming the closed circuit 7 is separated in the axial direction. A large distance can be secured.
Here, for example, the axial separation distance of the electromagnetic steel sheet 9 is proportional to the amount of interlinkage magnetic flux interlinking with the closed circuit 7. Further, when the amount of interlinkage magnetic flux increases, the induced current flowing through the closed circuit 7 can be increased. The induced current suppresses the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24.
As a result, by ensuring a large axial separation distance of the electromagnetic steel sheet 9, the induced current flowing through the closed circuit 7 can be increased, and the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24 can be suitably suppressed.

The rotary electric machine 1 of the first embodiment includes a rotor 4 and a stator 3 arranged on the outside of the rotor 4 at intervals. According to this configuration, the eddy current loss of the first magnet 23 and the second magnet 24 can be suppressed, the temperature rise of the first magnet 23 and the second magnet 24 can be suppressed, and the cost can be suppressed. Can be provided.

The method for manufacturing the rotor 4 includes a welding step of welding the wall surface of the magnet insertion hole along the axial direction of the rotor core 21. Therefore, the welded portion 51 is provided on the wall surface of the first magnet insertion hole 27 and the second magnet insertion holes 41 and 42. The welded portion 51 extends in the axial direction of the rotor core 21. Therefore, the laminated electromagnetic steel sheets 9 can be electrically connected to each other at the welded portion 51. As a result, a current path (closed circuit 7) can be formed by the welded portion 51 and the electromagnetic steel plate 9. Therefore, the eddy current can be suppressed and the eddy current loss of the first magnet 23 and the second magnet 24 can be suppressed. Further, by suppressing the eddy current loss of the first magnet 23 and the second magnet 24, it is possible to suppress the temperature rise of the first magnet 23 and the second magnet 24.

Further, a current path (closed circuit 7) was formed by the welded portion 51 and the electromagnetic steel plate 9. Therefore, without dividing the first magnet 23 and the second magnet 24, the eddy current is suppressed to suppress the eddy current loss of the first magnet 23 and the second magnet 24, and the first magnet 23 and the second magnet 24 It is possible to suppress the temperature rise. Thereby, the cost of the first magnet 23 and the second magnet 24 (that is, the rotor 4) can be suppressed.
Further, since the welded portions 51 are provided on the wall surfaces of the first magnet insertion holes 27 and the second magnet insertion holes 41 and 42, the electromagnetic steel sheets 9 are held in a laminated state. As a result, it is not necessary to crimp the electromagnetic steel sheets 9 to each other, so that the rotor core 21 can be formed with a simple configuration, and the cost of the rotary electric machine 1 can be further suppressed.
In addition, by suppressing the eddy current loss of the first magnet insertion holes 27 and the second magnet insertion holes 41 and 42 and suppressing the temperature rise of the first magnet 23 and the second magnet 24, the first magnet having a low coercive force is suppressed. A magnet 23 and a second magnet 24 can be used.
From the above, it is possible to provide the rotor 4 which can suppress the eddy current loss of the first magnet 23 and the second magnet 24, suppress the temperature rise of the permanent magnet, and further suppress the cost.

The laminating step includes a first laminating step of forming a plurality of rotor core pieces 22 in which the rotor core 21 is axially divided, and a second laminating step of laminating the plurality of rotor core pieces 22. Therefore, after forming the rotor core piece 22, the rotor core piece 22 can be laminated to form the rotor core 21.
For example, when the rotor core 21 long in the axial direction is formed, it becomes difficult to weld the wall surfaces of the first magnet insertion hole 27 and the second magnet insertion holes 41 and 42 along the axial direction.
On the other hand, since the present invention includes a first laminating step of forming a plurality of rotor core pieces 22 and a second laminating step of laminating a plurality of rotor core pieces 22, the rotor core pieces are divided in the axial direction. A welding process can be performed every 22. As a result, even when the rotor core 21 long in the axial direction is formed, the wall surfaces of the first magnet insertion hole 27 and the second magnet insertion holes 41 and 42 can be easily welded along the axial direction.
Therefore, the operator can arbitrarily select the timing of the welding step after the first laminating step or after the second laminating step, depending on the axial length of the rotor core 21. This makes it possible to provide a method for manufacturing the rotor 4 with improved biotechnique.

[Second Embodiment]
Next, the rotor 100 of the second embodiment will be described with reference to FIG. In the second embodiment, the same and similar components as the rotor 4 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
FIG. 12 is a cross-sectional view showing the rotor 100 of the second embodiment.
The rotor 100 has the voids of the flux barriers 37, 44, 45, 47, and 48 filled with the resin 55, and other configurations are the same as those of the rotor 4 of the first embodiment. Each of the flux barriers 37, 44, 45, 47, 48 is a pair of first flux barriers 37, a pair of second inner flux barriers 44, 47, and a pair of second outer flux barriers 45, 48.
In a state where the welded portions 51 are provided on the pair of first flux barriers 37, the voids of the pair of first flux barriers 37 are filled with the resin 55. Further, in a state where the welded portions 51 are provided on the pair of second outer flux barriers 45 and 48, the voids of the pair of second outer flux barriers 45 and 48 are filled with the resin 55. Further, the voids of the pair of second inner flux barriers 44 and 47 are filled with the resin 55.

As described above, in the rotor 100 of the second embodiment, the voids of the pair of first flux barriers 37 are filled with the resin 55. Therefore, the resin 55 holds the first magnet 23. As a result, the first magnet 23 can be fixed.
The voids of the second outer flux barrier 45 and the voids of the second inner flux barrier 44 are filled with the resin 55. Therefore, the resin 55 holds the second magnet 24. As a result, the second magnet 24 can be fixed. The voids of the second outer flux barrier 48 and the voids of the second inner flux barrier 47 are filled with the resin 55. Therefore, the resin 55 holds the second magnet 24. As a result, the second magnet 24 can be fixed.

In the above-described embodiment, the rotary electric machine 1 has been described by giving an example of being applied to a traveling motor mounted on a vehicle such as a hybrid vehicle or an electric vehicle, but the present invention is not limited to this. For example, the rotary electric machine 1 may be a motor for power generation, a motor for other purposes, or a rotary electric machine (including a generator) other than for vehicles.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and configurations can be added, omitted, replaced, and other changes can be made without departing from the spirit of the present invention. Yes, it is also possible to appropriately combine the above-mentioned modification examples.

1 Rotating machine 3 Stator 4,100 Rotor 9 Electromagnetic steel plate (steel sheet)
21 Rotor core 21a Outer end face of rotor core (axial end face)
21b Outer circumference 22 Rotor core piece 23 First magnet (permanent magnet)
24 Second magnet (permanent magnet)
26 End face plate 27 First magnet insertion hole (magnet insertion hole)
28 Second magnet insertion hole group 36 First magnet insertion part (magnet insertion part)
37 1st Flux Barrier (Flux Barrier)
41, 42 A pair of second magnet insertion holes (magnet insertion holes)
43,46 2nd magnet insertion part (magnet insertion part)
45,48 2nd outer flux barrier (flux barrier)
51 Welded part 55 Resin 57 First cooling medium passage 58 Second cooling medium passage (cooling medium passage)
Vd d axis

Claims (10)

A rotor core formed by laminating steel plates and
A plurality of magnet insertion holes formed at predetermined intervals in the circumferential direction of the rotor core, and
A permanent magnet embedded in the plurality of magnet insertion holes is provided.
A rotor characterized in that a welded portion extending in the axial direction of the rotor core is provided on the wall surface of the magnet insertion hole. The rotor according to claim 1, wherein at least a pair of welded portions are provided side by side in the circumferential direction. The magnet insertion hole includes a magnet insertion portion and a flux barrier.
The rotor according to claim 1 or 2, wherein the welded portion is provided on the flux barrier. A pair of end face plates are provided on the axial end faces of the rotor core.
The rotor according to claim 3, wherein the flux barrier communicates with a cooling medium passage provided in the end face plate. The rotor according to any one of claims 1 to 4, wherein the welded portion is provided on the outer peripheral side of the rotor core with respect to the permanent magnet. The rotor according to any one of claims 1 to 5, wherein the welded portion is provided so as to be symmetrical with respect to the d-axis. The rotor according to any one of claims 1 to 6, wherein the welded portion connects the steel plate at one end in the axial direction and the steel plate at the other end in the axial direction. The rotor according to any one of claims 1 to 7.
A stator arranged on the outside of the rotor at intervals,
A rotary electric machine characterized by being equipped with. A rotor core formed by laminating steel plates and
A plurality of magnet insertion holes formed at predetermined intervals in the circumferential direction of the rotor core, and
Permanent magnets embedded in the plurality of magnet insertion holes and
It is a method of manufacturing a rotor equipped with
A laminating process of laminating the steel plates to form the rotor core, and
A welding step of welding the wall surface of the magnet insertion hole along the axial direction of the rotor core, and
The embedding step of embedding the permanent magnet in the magnet insertion hole and
A method for manufacturing a rotor, which comprises. The laminating step includes a first laminating step of forming a plurality of rotor core pieces in which the rotor core is divided in the axial direction.
A second laminating step of laminating the plurality of rotor core pieces, and
9. The method for manufacturing a rotor according to claim 9.

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