Rotating electrical machine

A rotating electrical machine according to one aspect of the present invention includes: a rotor rotatable about a central axis; and a stator located radially outside the rotor. The rotor includes: a rotor core that includes a plurality of electromagnetic steel plates laminated in an axial direction and that has a plurality of accommodation holes; and a plurality of magnets respectively accommodated in the plurality of accommodation holes. The rotor core includes: a first recess recessed from a first core end face on a first axial side to a second axial side; a first swaged part provided on a bottom surface of the first recess; and a first protrusion that protrudes toward each of the magnets in a direction in which an inner peripheral edge of each of the accommodation holes intersects an axial direction, the first protrusion butting against a side face of the magnet.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2021-108973 filed on Jun. 30, 2021, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a rotating electrical machine.

BACKGROUND

A rotating electrical machine that includes a rotor core and a magnet placed in a hole provided in the rotor core is known. For example, an interior permanent magnet rotor is known in which an end part of a magnet inserted into a hole provided in a rotor core is held and fixed to the rotor core by swaging a steel plate located at an end of laminated steel plates constituting a yoke of the rotor core.

In the configuration as described above, the dimension of the laminated steel plates may be actually larger than the dimension of the magnet in the central axis direction of the rotor core due to manufacturing tolerance or the like. In such a case, when the steel plate located at the end in the central axis direction of the laminated steel plates is swaged, a portion protruding in a direction intersecting the central axis direction does not contact the magnet or butts against an end of the magnet in the central axis direction. When the swaged steel plate does not contact the magnet, the magnet cannot be fixed. In addition, when the swaged steel plate butts against the end of the magnet, the magnet may be damaged. As described above, the configuration described above has a problem that it is difficult to reliably fix the magnet to the rotor core while suppressing damage of the magnet.

SUMMARY

In one aspect of the present invention, an exemplary rotating electrical machine includes: a rotor that is rotatable about a central axis; and a stator that is located radially outside the rotor. The rotor includes: a rotor core that includes a plurality of electromagnetic steel plates laminated in an axial direction and that has a plurality of accommodation holes; and a plurality of magnets respectively accommodated in the plurality of accommodation holes. The rotor core includes: a first recess recessed from a first core end face on a first axial side to a second axial side; a first swaged part provided on a bottom surface of the first recess; and a first protrusion that protrudes toward each of the magnets in a direction in which an inner peripheral edge of each of the accommodation holes intersects the axial direction and that butts against a side face of the magnet.

DETAILED DESCRIPTION

A rotating electrical machine according to an embodiment of the present invention will be described below with reference to the drawings. Note that the scope of the present invention is not limited to the embodiment described below, but includes any modification thereof within the scope of the technical idea of the present invention. Also note that scales, numbers, and so on of members or portions illustrated in the following drawings may differ from those of actual members or portions, for the sake of easier understanding of the members or portions.

A Z-axis direction appropriately illustrated in each drawing is a vertical direction in which a positive side is an “upper side” and a negative side is a “lower side”. A central axis J appropriately illustrated in each drawing is a virtual line that is parallel to the Z-axis direction and extends in the vertical direction. In the following description, the term “axial direction”, “axial”, or “axially” refers to an axial direction of the central axis J, that is, a direction parallel with the vertical direction. The term “radial direction”, “radial”, or “radially” refers to a radial direction around the central axis J. The term “circumferential direction”, “circumferential”, or “circumferentially” refers to a circumferential direction about the central axis J. An arrow θ appropriately illustrated in each drawing indicates the circumferential direction. The arrow θ is directed in a clockwise direction around the central axis J when viewed from above. In the following description, a side to which the arrow θ is directed in the circumferential direction with a certain object as a reference, namely, a clockwise side as viewed from above is referred to as a “first circumferential side”, and a side opposite to the side to which the arrow θ is directed in the circumferential direction with the certain object as the reference, namely, a counterclockwise side as viewed from above is referred to as a “second circumferential side”.

The vertical direction, the upper side, and the lower side are merely terms for describing a relative positional relationship between the respective units, and an actual layout relationship and the like may be other than the layout relationship represented by these terms.

As illustrated inFIG.1, a rotating electrical machine1is an inner rotor type rotating electrical machine.

In the present embodiment, the rotating electrical machine1is a three-phase alternate-current rotating electrical machine. The rotating electrical machine1is, for example, a three-phase motor driven by being supplied with three-phase AC power. The rotating electrical machine1includes a housing2, a rotor10, a stator60, a bearing holder4, and bearings5aand5b.

The housing2accommodates therein the rotor10, the stator60, the bearing holder4, and the bearings5aand5b. The bottom part of the housing2holds the bearing5b. The bearing holder4holds the bearing5a. Each of the bearings5aand5bis, for example, a ball bearing.

The stator60is positioned radially outside the rotor10. The stator60includes a stator core61, an insulator64, and a plurality of coils65. As illustrated inFIGS.1and2, the stator core61includes a core back62and a plurality of teeth63. The core back62is located radially outside the rotor core20to be described later.

As illustrated inFIG.2, the core back62has an annular shape surrounding the rotor core20. The core back62has, for example, an annular shape centered on the central axis J.

The plurality of teeth63extends inwardly in the radial direction from the core back62. The teeth63are spaced apart from one another in the circumferential direction. The teeth63are equally spaced over the entire circumference along the circumferential direction. For example, 48 teeth63are provided. That is, the number of slots67of the rotating electrical machine1is, for example, 48.

As illustrated inFIG.1, the plurality of coils65is attached to the stator core61. The coils65are attached to the teeth63with the insulator64interposed therebetween. In the present embodiment, distributed winding is used for the coils65. That is, each coil65is wound across the plurality of teeth63. In the present embodiment, full-pitch winding is used for the coils65. That is, the circumferential pitch between slots of the stator60into which the coils65are inserted is equal to the circumferential pitch of magnetic poles generated when three-phase AC power is supplied to the stator60. The number of poles of the rotating electrical machine1is, for example, eight. That is, the rotating electrical machine1is, for example, an 8-pole 48 slot rotating electrical machine. As described above, in the rotating electrical machine1according to the present embodiment, when the number of poles is N, the number of slots is N×6.

The rotor 10 is rotatable about the central axis J. As illustrated inFIG.2, the rotor10includes a shaft11, a rotor core20, and a plurality of magnets40. The shaft11has a columnar shape that extends in the axial direction about the central axis J. As illustrated inFIG.1, the shaft11is rotatably supported about the central axis J by bearings5aand5b.

The rotor core20is a magnetic body. The rotor core20is fixed to an outer peripheral surface of the shaft11. The rotor core20has a through hole21that penetrates the rotor core20in the axial direction. As illustrated inFIG.2, the through hole21has a circular shape centered on the central axis J when viewed in the axial direction. The shaft11passes through the through hole21. The shaft11is fixed inside the through hole21by press fitting, for example. The rotor core20is formed by laminating, for example, a plurality of electromagnetic steel plates25in the axial direction.

As illustrated inFIGS.2to4, the rotor core20has a plurality of accommodation holes30. For example, the plurality of accommodation holes30penetrates the rotor core20in the axial direction. The plurality of magnets40is accommodated in the plurality of accommodation holes30, respectively. The plurality of accommodation holes30includes a pair of first accommodation holes31aand31band a second accommodation hole32.

The type of the plurality of magnets40is not particularly limited. The magnet40may be, for example, a neodymium magnet or a ferrite magnet. The plurality of magnets40includes a pair of first magnets41aand41band a second magnet42. The pair of first magnets41aand41band the second magnet42constitute a pole.

In the present embodiment, a plurality of the pairs of first accommodation holes31aand31b, a plurality of the pairs of first magnets41aand41b, a plurality of the second accommodation holes32, and a plurality of the second magnets42are provided at intervals in the circumferential direction. Eight pairs of first accommodation holes31aand31b, eight pairs of first magnets41aand41b, eight second accommodation holes32, and eight second magnets42are provided, for example.

The rotor10includes a plurality of magnetic pole sections70each including a pair of first accommodation holes31aand31b, a pair of first magnets41aand41b, the second accommodation hole32, and the second magnet42. As illustrated inFIG.2, eight magnetic pole sections70are provided, for example. The magnetic pole sections70are, for example, equally spaced over an entire circumference along the circumferential direction. The plurality of magnetic pole sections70includes a plurality of magnetic pole sections70N in which the magnetic pole on the outer peripheral surface of the rotor core20is an N pole and a plurality of magnetic pole sections70S in which the magnetic pole on the outer peripheral surface of the rotor core20is an S pole. For example, four magnetic pole sections70N and four magnetic pole sections70S are provided. The four magnetic pole sections70N and the four magnetic pole sections70S are alternately arranged along the circumferential direction. The configurations of the magnetic pole sections70are similar to one another except that the magnetic poles on the outer peripheral surface of the rotor core20are different and the circumferential positions are different.

As illustrated inFIGS.3and4, the pair of first accommodation holes31aand31bis spaced from each other in the circumferential direction in each of the magnetic pole sections70. For example, the first accommodation hole31ais located on a first circumferential side (+θ side) of the first accommodation hole31b. For example, the first accommodation holes31aand31bextend substantially linearly in a direction inclined obliquely with respect to the radial direction when viewed in the axial direction. The pair of first accommodation holes31aand31bextends in directions away from each other in the circumferential direction from inside to outside in the radial direction when viewed in the axial direction. That is, a circumferential distance between the first accommodation hole31aand the first accommodation hole31bincreases from inside to outside in the radial direction. The first accommodation hole31ais located, for example, further to the first circumferential side as it extends from inside to outside in the radial direction. The first accommodation hole31bis, for example, located further to a second circumferential side (−θ side) as it extends from inside to outside in the radial direction. The outer radial ends of the first accommodation holes31aand31bare located at an outer peripheral end of the rotor core20in the radial direction.

The first accommodation hole31aand the first accommodation hole31bare located, for example, with a magnetic pole center line IL1inFIG.3constituting a d axis therebetween in the circumferential direction when viewed in the axial direction. The magnetic pole center line IL1is a virtual line passing through the center of the magnetic pole section70in the circumferential direction and the central axis J and extending in the radial direction. The first accommodation hole31aand the first accommodation hole31bare arranged so as to be symmetrical with respect to the magnetic pole center line IL1when viewed in the axial direction, for example. Hereinafter, the description of the configurations of the first accommodation hole31bsame as the configurations of the first accommodation hole31amay be omitted except that the first accommodation holes31aand31bare symmetrical with respect to the magnetic pole center line IL1.

The first accommodation hole31aincludes a first linear part31c, an inner end part31d, and an outer end part31e. The first linear part31cextends linearly in the direction in which the first accommodation hole31aextends when viewed in the axial direction. The first linear part31chas, for example, a rectangular shape when viewed in the axial direction. The inner end part31dis connected to an inner radial end of the first linear part31c. The inner end part31dis an inner radial end of the first accommodation hole31a. The outer end part31eis connected to an outer radial end of the first linear part31c. The outer end part31eis an outer radial end of the first accommodation hole31a. The outer end part31eextends outward in the radial direction along the magnetic pole center line IL1from the outer radial end of the first linear part31c. The first accommodation hole31bincludes a first linear part31f, an inner end part31g, and an outer end part31h.

The second accommodation hole32is located between the outer radial ends of the pair of first accommodation holes31aand31bin the circumferential direction. That is, in the present embodiment, the second accommodation hole32is located between the outer end part31eand the outer end part31hin the circumferential direction. The second accommodation hole32extends, for example, substantially linearly in a direction orthogonal to the radial direction when viewed in the axial direction. The second accommodation hole32extends, for example, in a direction orthogonal to the magnetic pole center line IL1when viewed in the axial direction. The pair of first accommodation holes31aand31band the second accommodation hole32are located along, for example, a V shape when viewed in the axial direction.

In the present specification, “a certain object extends in a direction orthogonal to a certain direction” includes not only a case where the certain object extends in a direction strictly orthogonal to the certain direction but also a case where the certain object extends in a direction substantially orthogonal to the certain direction. The “direction substantially orthogonal to a certain direction” includes, for example, a direction inclined within a range of about several degrees [°] with respect to the direction strictly orthogonal to the certain direction due to a tolerance or the like at the time of manufacturing.

The magnetic pole center line IL1passes through the circumferential center of the second accommodation hole32when viewed in the axial direction. That is, the circumferential position of the circumferential center of the second accommodation hole32coincides with, for example, the circumferential position of the circumferential center of the magnetic pole section70. The second accommodation hole32has, for example, a symmetrical shape with respect to the magnetic pole center line IL1as viewed in the axial direction. The second accommodation hole32is located at an outer peripheral end of the rotor core20in the radial direction.

The second accommodation hole32includes a second linear part32a, a first end part32b, and a second end part32c. The second linear part32aextends linearly in the direction in which the second accommodation hole32extends when viewed in the axial direction. The second linear part32ahas, for example, a rectangular shape when viewed in the axial direction. The first end part32bis connected to an end of the second linear part32aon the first circumferential side (+θ side). The first end part32bis an end of the second accommodation hole32on the first circumferential side. The first end part32bis located on the second circumferential side (−θ side) of the outer end part31eof the first accommodation hole31aso as to be spaced from the outer end part31e. The second end part32cis connected to an end of the second linear part32aon the second circumferential side (−θ side). The second end part32cis an end of the second accommodation hole32on the second circumferential side. The second end part32cis located on the first circumferential side of the outer end part31hof the first accommodation hole31bso as to be spaced from the outer end part31h.

The pair of first magnets41aand41bis accommodated in the pair of first accommodation holes31aand31b, respectively. The first magnet41ais accommodated in the first accommodation hole31a. The first magnet41bis accommodated in the first accommodation hole31b. The pair of first magnets41aand41bhas, for example, a rectangular shape when viewed in the axial direction. The lengths of the pair of first magnets41aand41bin the direction in which the first magnets41aand41bextend are the same. The lengths of the first magnets41aand41bin the direction orthogonal to the direction in which the pair of first magnets41aand41bextends are the same.

The first magnets41aand41bhave, for example, a rectangular parallelepiped shape. As illustrated inFIG.5, the axial lengths of the first magnets41aand41bare slightly smaller than the entire axial lengths of the first accommodation holes31aand31b, for example. As illustrated inFIGS.3and4, the pair of first magnets41aand41bis spaced from each other in the circumferential direction. The first magnet41ais located on the first circumferential side (+θ side) of the first magnet41b.

The first magnet41aextends along the first accommodation hole31awhen viewed in the axial direction. The first magnet41bextends along the first accommodation hole31bwhen viewed in the axial direction. The first magnets41aand41bextend, for example, substantially linearly in a direction inclined obliquely with respect to the radial direction when viewed in the axial direction. The pair of first magnets41aand41bextends in directions away from each other in the circumferential direction from inside to outside in the radial direction when viewed in the axial direction. That is, the circumferential distance between the first magnet41aand the first magnet41bincreases as they extend from inside to outside in the radial direction.

The first magnet41ais located further to the first circumferential side (+θ side) as it extends from inside to outside in the radial direction. The first magnet41bis located further to the second circumferential side (−θ side) as it extends from inside to outside in the radial direction. The first magnet41aand the first magnet41bare located with the magnetic pole center line IL1therebetween in the circumferential direction when viewed in the axial direction, for example. The first magnet41aand the first magnet41bare located so as to be symmetrical with respect to the magnetic pole center line IL1when viewed in the axial direction, for example. Hereinafter, the description of the configurations of the first magnet41bsame as the configurations of the first magnet41amay be omitted except that the first magnets41aand41bare symmetrical with respect to the magnetic pole center line IL1.

The first magnet41ais fitted in the first accommodation hole31a. More specifically, the first magnet41ais inserted into the first linear part31c. In the direction in which the first linear part31cextends when viewed in the axial direction, the length of the first magnet41ais the same as, for example, the length of the first linear part31c.

When viewed in the axial direction, each end of the first magnet41ain the direction in which the first magnet41aextends is separated from the corresponding end of the first accommodation hole31ain the direction in which the first accommodation hole31aextends. When viewed in the axial direction, the inner end part31dand the outer end part31eare located adjacent to the first magnet41aon each side of the first magnet41ain the direction in which the first magnet41aextends. In the present embodiment, the inner end part31dconstitutes a first flux barrier section51a. The outer end part31econstitutes a first flux barrier section51b. That is, the rotor core20includes a pair of first flux barrier sections51aand51barranged with the first magnet41ainterposed therebetween in the direction in which the first magnet41aextends when viewed in the axial direction. The rotor core20includes a pair of first flux barrier sections51cand51darranged with the first magnet41binterposed therebetween in the direction in which the first magnet41bextends when viewed in the axial direction.

The first flux barrier section51bon the outer radial side extends to the outside in the radial direction from the radial end of the first magnet41ain parallel with the magnetic pole center line IL1. The first flux barrier section51dlocated on the outer radial side extends to the outside in the radial direction from the radial end of the first magnet41bin parallel with the magnetic pole center line IL1.

As described above, the rotor core20includes a pair of the first flux barrier sections51aand51barranged with the first magnet41ainterposed therebetween in the direction in which the first magnet41aextends and a pair of the first flux barrier sections51cand51darranged with the first magnet41binterposed therebetween in the direction in which the first magnet41bextends, when viewed in the axial direction. The first flux barrier sections51a,51b,51c, and51dand second flux barrier sections52aand52bdescribed later are sections where the flow of magnetic flux can be suppressed. That is, the magnetic flux hardly passes through each of the flux barrier sections. Each flux barrier section is not particularly limited as long as it can suppress the flow of magnetic flux, and it may include a void and may include a non-magnetic portion such as a resin portion.

The second magnet42is accommodated in the second accommodation hole32. The second magnet42is located at a circumferential position between the pair of first magnets41aand41bon the outside in the radial direction with respect to the inner radial ends of the pair of first magnets41aand41b. The second magnet42extends along the second accommodation hole32when viewed in the axial direction. The second magnet42extends in a direction orthogonal to the radial direction as viewed in the axial direction. The pair of first magnets41aand41band the second magnet42are located along, for example, a V shape when viewed in the axial direction.

In the present specification, “the second magnet is located at the circumferential position between the pair of first magnets” means that the circumferential position of the second magnet may be included in the circumferential position between the pair of first magnets, and the radial position of the second magnet with respect to the first magnet is not particularly limited.

The second magnet42has, for example, a symmetrical shape with respect to the magnetic pole center line IL1as viewed in the axial direction. The second magnet42has, for example, a rectangular shape when viewed in the axial direction. When viewed in the axial direction, the radial length of the second magnet42is shorter than the lengths of the first magnets41aand41bin the direction orthogonal to the direction in which the first magnets41aand41bextend. Since the radial length of the second magnet42is set shorter than the lengths of the first magnets41aand41bin the direction orthogonal to the direction in which the first magnets41aand41bextend, the second magnet42is thinner, whereby the second magnet42has a weight smaller than the weight of each of the first magnets41aand41b. Since the weight of the second magnet42is reduced, the centrifugal force of the second magnet42during the rotation of the rotor10can be reduced. Therefore, the load on the rotor core20can be reduced.

Due to the second magnet42being thinner, the second magnet42can be located on the outer part of the rotor core20in the radial direction. Due to the second magnet42being located on the outer part of the rotor core20in the radial direction, the output of the rotating electrical machine1can be increased. The magnetization of the second magnet42is strengthened by the first magnets41aand41b, and thus, it is possible to increase the strength of the rotor core20and the output of the rotating electrical machine1without impairing the demagnetization resistance. Furthermore, high demagnetization resistance can be obtained with a small amount of magnets.

The second magnet42has, for example, a rectangular parallelepiped shape. It is possible to increase the output of the rotating electrical machine1. The axial length of the second magnet42is slightly smaller than the entire axial length of the second accommodation hole32, for example. As illustrated inFIGS.3and4, the inner radial part of the second magnet42is located, for example, between the outer radial ends of the pair of first magnets41aand41bin the circumferential direction. The outer radial part of the second magnet42is located, for example, radially outside the pair of first magnets41aand41b.

The second magnet42is fitted in the second accommodation hole32. More specifically, the second magnet42is inserted into the second linear part32a. In the direction in which the second linear part32aextends when viewed in the axial direction, the length of the second magnet42is, for example, the same as the length of the second linear part32a.

When viewed in the axial direction, each end of the second magnet42in the direction in which the second magnet42extends is spaced from the corresponding end of the second accommodation hole32in the direction in which the second accommodation hole32extends. When viewed in the axial direction, the first end part32band the second end part32care located adjacent to the second magnet42on each side of the second magnet42in the direction in which the second magnet42extends. In the present embodiment, the first end part32bconstitutes a second flux barrier section52a. The second end part32cconstitutes a second flux barrier section52b. That is, the rotor core20includes a pair of second flux barrier sections52aand52barranged with the second magnet42interposed therebetween in the direction in which the second magnet42extends when viewed in the axial direction.

Each of the second flux barrier sections52aand52bhas an arc shape directed to the inside in the radial direction as it extends in the direction away from the second magnet42in the circumferential direction from the circumferential end of the second magnet42. When the second flux barrier sections52aand52bextend to the outside in the radial direction, the distance between the second flux barrier sections52aand52band the outer peripheral surface of the rotor core20decreases, so that the load on the rotor core20may increase due to the centrifugal force during rotation. Since the second flux barrier sections52aand52bextend to the inside in the radial direction, the load on the rotor core20can be reduced. Due to the second flux barrier sections52aand52bbeing formed in an arc shape, it is possible to reduce stress concentration at an intersection between the portion extending in the circumferential direction and the portion extending in the radial direction, whereby the load on the rotor core20can further be reduced.

The pair of second flux barrier sections52aand52band the second magnet42are located circumferentially between the first flux barrier section51blocated on the outer radial side out of the pair of first flux barrier sections51aand51bprovided across the first magnet41aand the first flux barrier section51dlocated on the outer radial side out of the pair of first flux barrier sections51cand51dprovided across the first magnet41b.

The magnetic poles of the first magnet41aare arranged along a direction orthogonal to the direction in which the first magnet41aextends when viewed in the axial direction. The magnetic poles of the first magnet41bare arranged along a direction orthogonal to the direction in which the first magnet41bextends when viewed in the axial direction. The magnetic poles of the second magnet42are arranged along the radial direction.

The magnetic pole located on the outer radial side out of the magnetic poles of the first magnet41a, the magnetic pole located on the outer radial side out of the magnetic poles of the first magnet41b, and the magnetic pole located on the outer radial side out of the magnetic poles of the second magnet42are the same. The magnetic pole located on the inner radial side out of the magnetic poles of the first magnet41a, the magnetic pole located on the inner radial side out of the magnetic poles of the first magnet41b, and the magnetic pole located on the inner radial side out of the magnetic poles of the second magnet42are the same.

In the magnetic pole section70N, the magnetic pole located on the outer radial side out of the magnetic poles of the first magnet41a, the magnetic pole located on the outer radial side out of the magnetic poles of the first magnet41b, and the magnetic pole located on the outer radial side out of the magnetic poles of the second magnet42are, for example, an N pole as illustrated inFIG.3. In the magnetic pole section70N, the magnetic pole located on the inner radial side out of the magnetic poles of the first magnet41a, the magnetic pole located on the inner radial side out of the magnetic poles of the first magnet41b, and the magnetic pole located on the inner radial side out of the magnetic poles of the second magnet42are, for example, an S pole.

Although not illustrated, in the magnetic pole section70S, the magnetic poles of each magnet40are inverted with respect to those of the magnetic pole section70N. That is, in the magnetic pole section70S, the magnetic pole located on the outer radial side out of the magnetic poles of the first magnet41a, the magnetic pole located on the outer radial side out of the magnetic poles of the first magnet41b, and the magnetic pole located on the outer radial side out of the magnetic poles of the second magnet42are, for example, an S pole. In the magnetic pole section70S, the magnetic pole located on the inner radial side out of the magnetic poles of the first magnet41a, the magnetic pole located on the inner radial side out of the magnetic poles of the first magnet41b, and the magnetic pole located on the inner radial side out of the magnetic poles of the second magnet42are, for example, an N pole.

As illustrated inFIG.6, the rotor core20includes a first recess80, a first swaged part82, and a first protrusion84.

As illustrated inFIGS.3and4, the first recess80is provided corresponding to each of the accommodation holes30(first accommodation holes31aand31band second accommodation hole32). In the present embodiment, the first recess80is provided adjacent to each of the accommodation holes30(first accommodation holes31aand31b, second accommodation hole32) on the inner radial side. For example, two first recesses80aprovided corresponding to the first accommodation hole31aare spaced from each other in the direction in which the first linear part31cof the first accommodation hole31aextends on the inner radial side with respect to the first linear part31c. Two first recesses80bprovided corresponding to the first accommodation hole31bare spaced from each other in the direction in which the first linear part31fof the first accommodation hole31bextends on the inner radial side with respect to the first linear part31f. For example, two first recesses80cprovided adjacent to the second accommodation hole32are spaced from each other in the direction in which the second linear part32aof the second accommodation hole32extends on the inner radial side with respect to the second linear part32a.

As illustrated inFIG.6, each of the first recesses80is recessed from a first core end face20aof the rotor core20on the first axial side to the second axial side. The plurality of electromagnetic steel plates25includes one or more first electromagnetic steel plates25P located on the first axial side and a second electromagnetic steel plate25Q located on the second axial side with respect to the first electromagnetic steel plates25P. Each of the first recesses80is defined by a notch81provided in one or more first electromagnetic steel plates25P located on the first axial side. In the present embodiment, each of the first recesses80is defined by the notch81provided in, for example, two outermost first electromagnetic steel plates25P on the first axial side. The notch81is provided so as to communicate with the accommodation hole30. In the present embodiment, the notch81is formed into, for example, a U shape when viewed in the axial direction.

A bottom surface81dof the first recess80is exposed to the inside of the first recess80and is constituted by the second electromagnetic steel plate25Q placed on the second axial side with respect to the first electromagnetic steel plates25P. The bottom surface81dof the first recess80is located at the same position in the axial direction as a magnet end face40fof the magnet40on the first axial side or located further to the second axial side with respect to the magnet end face40f. In the present embodiment, the bottom surface81dof the first recess80is located further to the second axial side with respect to the magnet end face40f. The magnet end face40fis located further to the second axial side with respect to the first core end face20a. That is, the magnet end face40fis located further to the second axial side with respect to the first core end face20a. A magnet end face40gof the magnet40on the second axial side is located at substantially the same position in the axial direction as a second core end face20bof the rotor core20on the second axial side. This is achieved by inserting the magnet40into each accommodation hole30so that the magnet end face40gon the second axial side butts against the second core end face20bin a state where the second core end face20bof the rotor core20butts against an assembly working face F during the assembly of the rotor core20as illustrated inFIG.7.

As illustrated inFIG.6, the first swaged part82is provided on the bottom surface81dof the first recess80. As illustrated inFIG.7, the first swaged part82is provided by swaging the second electromagnetic steel plate25Q exposed to the inside of the first recess80with a tool T such as a punch. As illustrated inFIG.6, the first swaged part82is a recess provided by swaging the second electromagnetic steel plate25Q with the tool T.

The first protrusion84is provided by swaging the second electromagnetic steel plate25Q inside the first recess80with the tool T so that the second electromagnetic steel plate25Q protrudes toward the magnet40in the direction in which the inner peripheral edge of the accommodation hole30intersects the axial direction. The first protrusion84butts against a side face40sof the magnet40. When the first protrusion84butts against the side face40sof the magnet40, a side face40tof the magnet40directed radially outside is pressed against the inner peripheral surface of each accommodation hole30.

As illustrated inFIG.6, the first protrusion84butts against the side face40sof each magnet40(first magnets41aand41band second magnet42) directed radially inside and the side face40tdirected radially outside butts against the inner peripheral surface of the accommodation hole30(first accommodation holes31aand31b, second accommodation hole32), whereby each magnet40is fixed to the rotor core20.

According to the above configuration, the first swaged part82is provided on the bottom surface81dof the first recess80recessed from the first core end face20aof the rotor core20to the second axial side, so that the first protrusion84butts against the side face40sof the magnet40. Thus, the magnet40is reliably fixed to the rotor core20. In addition, since the first protrusion84butts against the side face40sof the magnet40, the damage of the magnet40is suppressed. Therefore, it is possible to reliably fix the magnet40to the rotor core20while suppressing the damage of the magnet40.

According to the above configuration, the bottom surface81dof the first recess80is located at the same position in the axial direction as the magnet end face40fof the magnet40on the first axial side or located further to the second axial side with respect to the magnet end face40f, so that the first protrusion84reliably butts against the side face40sof the magnet40.

According to the above configuration, the first recess80can be easily formed by providing the notch81in the first electromagnetic steel plate25P. Since the bottom surface81dof the first recess80is defined by the second electromagnetic steel plate25Q, the first protrusion84can be provided by protruding the second electromagnetic steel plate25Q toward the magnet40in the direction intersecting the axial direction.

According to the above configuration, even when the magnet end face40fdoes not protrude to the first axial side from the first core end face20aand is located further to the second axial side with respect to the first core end face20a, the magnet40can be reliably fixed to the rotor core20by butting the first protrusion84against the side face40sof the magnet40.

According to the above configuration, the magnet40can be placed on the outer radial side of the rotor core20by providing the first protrusion84on the inner radial side with respect to the magnet40. Thus, the output of the rotating electrical machine1can be increased.

According to the above configuration, the notch81communicates with the accommodation hole30, whereby the notch81and the accommodation hole30can be easily machined as one opening in the laminated steel plates.

While the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it is obvious that the present invention is not limited to the embodiment. Various shapes, combinations, and the like of the constituent members in the above embodiment are only by way of example, and various modifications are possible based on design requirements and the like without departing from the scope of the present invention.

For example, as illustrated inFIG.8, the rotor core may include a second swaged part92formed on the second core end face20bon the second axial side, and a second protrusion94that protrudes toward the magnet40in a direction in which the inner peripheral edge of the accommodation hole30intersects the axial direction and that butts against the side face40sof the magnet40.

According to the above configuration, the second swaged part92and the second protrusion94are provided on the second core end face20bside of the rotor core20on the second axial side in addition to the first protrusion84, whereby the magnet40can be firmly fixed on the first axial side and on the second axial side.

Although, in the above embodiment, two first recesses80are provided for each accommodation hole30, the number of the first recesses80is not particularly limited. One first recess80may be provided for each accommodation hole30, or three or more first recesses may be provided.

In addition, although the first recess80is provided on the inner radial side with respect to each accommodation hole30, the present invention is not limited thereto. The first recess80may be provided on the outer radial side with respect to each accommodation hole30, or may be provided on both the inner radial side and the outer radial side with respect to each accommodation hole30.

In addition, although the first recess80includes the notch81provided in the first electromagnetic steel plate25P so as to face the accommodation hole30, the present invention is not limited thereto. The first recess80may be a hole provided at a position separated from the accommodation hole30.

The rotating electrical machine to which the present invention is applied is not limited to a motor, and may be a generator. In this case, the rotating electrical machine may be a three-phase AC generator. The application of the rotating electrical machine is not particularly limited. For example, the rotating electrical machine may be mounted on a vehicle or may be mounted on equipment other than a vehicle. The number of poles and the number of slots of the rotating electrical machine are not particularly limited. In the rotating electrical machine, the coil may be wound using any winding method. The features described above in the present description may be appropriately combined as long as no conflict arises.