ROTOR AND ROTARY MACHINE

In a rotating body (32) of a rotor (30), a plurality of permanent magnets (45) are arranged in a circumferential direction, alternating with a plurality of divided cores (33). The plurality of permanent magnets (45) is in surface contact with side surfaces of the divided cores (33) in the circumferential direction in a state where facing magnetic pole faces of two permanent magnets (45) arranged on both sides of each divided core (33) in the circumferential direction are homopolar. In a resin covering portion (50) of the rotating body (32), a first part (51) and a second part (52) cover end surfaces of the plurality of permanent magnets (45), a plurality of third parts (53) covers outer peripheral surfaces of the plurality of permanent magnets (45), and a fourth part (54) covers inner peripheral surfaces of the plurality of divided cores (33) and inner peripheral surfaces of the plurality of permanent magnets (45). Outer peripheral surfaces of the divided cores (33) are exposed without being covered by the covering portion (50).

TECHNICAL FIELD

The present invention relates to a rotor of a rotary machine such as a motor or an electrical generator, and the rotary machine.

BACKGROUND ART

A technique related to a rotary machine has been proposed. For example, an interior permanent magnet motor is disclosed in Patent Literature 1. A rotator of the interior permanent magnet motor integrally includes a shaft, permanent magnets, and a plurality of electric steel sheets. The shaft, the permanent magnets, and the plurality of electric steel sheets are molded by resin injection insertion. The shaft is made of stainless steel. The plurality of electric steel sheets form pole shoes separated according to the magnetic poles. The electric steel sheets have a fan shape divided according to the magnetic poles, and are bonded in a state of being laminated in an axial direction. The rotator has 10 poles. In the rotator, the permanent magnets are radially provided on both sides of a magnetic pole portion formed of the electric steel sheets. An entire outer periphery of the rotator is covered with resin. The resin fills on inner sides of the electric steel sheets and the permanent magnets. In the rotator, a permanent magnet holding member may be mounted on each side of the electric steel sheets in the axial direction. In a method for manufacturing the rotator, the shaft, the permanent magnets, and the plurality of electric steel sheets are integrated using an adhesive, and are molded by resin injection insertion.

A rotating electrical machine is disclosed in Patent Literature 2. In the rotating electrical machine, a rotor includes a shaft, a rotor core, a plurality of first permanent magnets, a plurality of second permanent magnets, and plates. The rotor core includes a plurality of first core portions, and a plurality of second core portions. Each first core portion functions as the N pole of the rotor, and each second core portion functions as the S pole of the rotor. The plurality of first core portions and the plurality of second core portions are alternately arranged at substantially equiangular intervals along a circumferential direction. The plurality of first permanent magnets and the plurality of second permanent magnets are provided inside the rotor core, radially from an inner peripheral portion side toward an outer peripheral portion side. The first and second permanent magnets are arranged adjacent to each other between each first core portion and the corresponding second core portion. Inner peripheral surfaces of the first permanent magnet and the second permanent magnet are arranged at positions spaced radially outward from an outer peripheral surface of the shaft. A gap is provided on the inner peripheral surface side of these permanent magnets. An adhesive layer fills the gap. In addition to the adhesive layer, a ring member made of resin may fills the gap. The adhesive layer fills a aap between the first permanent magnet and the first core portion, a gap between the second permanent magnet and the second core portion, a gap between the first permanent magnet and the second permanent magnet, a gap between the first permanent magnet and a magnet covering portion of the first core portion, and a gap between the second permanent magnet and a magnet covering portion of the second core portion. The rotor core, the first permanent magnet, and the second permanent magnet are sandwiched between two plates from both sides in an axial direction. Each plate is formed of a non-magnetic material such as stainless steel or resin.

A rotor of a synchronous motor is disclosed in Patent Literature 3. In the rotor, rotor cores and magnets are alternately provided in a circumferential direction. Resin for molding fills between an inner peripheral surface of the rotor and an outer peripheral surface of an output shaft. The previously-described resin overflows from a gap between the magnet and the rotor core onto the surface of the rotor. At the time of filling the resin, a cylindrical jig case covers an outer side of the rotor. Consequently, the overflowing resin is contained in the maximum outer diameter of the rotor.

A rotor core of a rotator for a permanent magnet rotating motor is disclosed in Patent Literature 4. Eight pole pieces, eight grooves, and eight round grooves are formed in the rotor core. An arc-shaped linking portion is formed at an outer peripheral end of each pole piece. The pole pieces are coupled. Eight permanent magnets and a shaft are mounted on the pole pieces. A space is formed between the shaft and each of inner peripheral end surfaces of the eight permanent magnets and the eight pole pieces. The space is continuous with the eight grooves. Aluminum fills the space and the eight grooves, which are continuous, to form a rotor. The eight linking portions are cut in the rotor. Consequently, the eight pole pieces are separated.

A permanent magnet rotator is disclosed in Patent Literature 5. The permanent magnet rotator includes a rotator iron core. The rotator iron core is configured in such a manner that pole pieces and permanent magnets are arranged radially on an outer periphery of a rotator shaft, and are formed into a cylindrical shape. The pole piece is formed by laminating laminate pieces made of fan-shaped steel sheets to a predetermined thickness. Each permanent magnet is provided between the pole pieces. A wedge-shaped projection is provided on a part where two planer surfaces of the pole piece intersect. A support portion is integrally molded by resin molding on the outer periphery of the rotator shaft. The support portion is provided with a wedge-shaped engagement groove. In the permanent magnet rotator, the projection and the engagement groove are engaged with each other. The support portion is integrally molded with a flange portion that supports one end of the rotator iron core. A keep plate is fixed to the rotator shaft at the other end of the rotator iron core. The keep plate is formed of a non-magnetic material.

A brushless motor is disclosed in Patent Literature 6. The brushless motor includes a rotor and a stator. The rotor has a rotor core and a plurality of magnets. The rotor core has a ring-shaped portion, a plurality of fan-shaped pole pieces, a plurality of magnet housing portions, and a plurality of first magnetic flux blocking portions. The ring-shaped portion is formed around a through-hole into which a rotation shaft is inserted. The plurality of pole pieces is formed radially from the ring-shaped portion. The plurality of magnet housing portions is formed radially between two adjacent pole pieces. The magnet housing portions are formed radially about the rotation axis of the rotor core. The magnets are housed in the magnet housing portions in such a manner that the same magnetic poles of adjacent magnets face each other in a circumferential direction of the rotor core. The magnet housing portion has a second magnetic flux blocking portion at an end on a rotation shaft side. The first magnetic flux blocking portions are formed on an outer side of the ring-shaped portion. The first magnetic flux blocking portion is formed between the second magnetic flux blocking portions adjacent to each other. The first magnetic flux blocking portions and the second magnetic flux blocking portions prevent a short circuit of magnetic flux from the plate-shaped magnets in the rotor core.

An interior permanent magnet rotating electrical machine is disclosed in Patent Literature 7. In a rotor of the interior permanent magnet rotating electrical machine, magnets are mounted in a rotor core. The rotor core is formed by laminating plate-shaped members. The plate-shaped member is made of a magnetic composite material. The magnetic composite material has a ferromagnetic portion and a feebly magnetic portion in the same member. The feebly magnetic portion of the plate-shaped member is formed by processing and heat treating a ferromagnetic material.

An interior permanent magnet rotor is disclosed in Patent Literature 8. In the rotor, two permanent magnets are paired to be arranged at equal angles in a circumferential direction. Magnet housing holes are formed in an axial direction in a rotor core of the rotor. Two permanent magnets forming one pole are housed and fixed in each housing hole. Two permanent magnets form a V-shape in which the two permanent magnets are apart from each other on an outer peripheral surface side. The rotor core is formed by laminating integral core sheets and divided core sheets alternately. Each divided core sheet includes a plurality of outer core pieces and a plurality of inner core pieces. Each outer core piece is fixed to an outer area surface of the integral core sheet. Each inner core piece is fixed to an inner area surface of the integral core sheet. In the rotor core, an outer bridge portion and an inner bridge portion are formed of a magnetic part of the integral core sheet, and a non-magnetic part of a gap created by the outer core piece and the inner core piece. The rotor core may be formed by laminating the integral core sheets and the divided core sheets, the numbers of which are different from each other, in a predetermined order. For example, in the rotor core, the plurality of divided core sheets may be laminated between the integral core sheet and the integral core sheet.

An interior magnet rotor is disclosed in Patent Literature 9. The interior magnet rotor includes a rotor core and a plurality of magnets. The rotor core is divided in a circumferential direction. The rotor core includes cutout portions on both divided surfaces. The cutout portions are hole portions in a state where the rotor cores are joined in a ring shape. The plurality of magnets is locked in the plurality of hole portions in a state where the polarities are alternated.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Problems to be Solved by the Invention

A rotary machine is in practical use. The rotary machine includes a rotor.

The rotor includes a permanent magnet inside a rotating body. The rotary machine of such a type is referred to as, for example, an interior permanent magnet rotary machine. The rotary machine includes a motor and an electrical generator. For example, in an interior permanent magnet motor, magnet torque and reluctance torque act on the rotor due to a magnetic flux from a stator. Hence, according to the interior permanent magnet motor, the previously-described two types of torque enable, for example, an increase in torque or a reduction in power consumption. The inventor has considered a structure that can reduce leakage magnetic flux in the rotor of the interior permanent magnet rotary machine. The reduction in leakage magnetic flux can increase the useful magnetic flux. At this point in time, the inventor conceived the structure of a rotor in which the permanent magnet can be fixed to a rotor core formed of electric steel sheets without rattling and displacement of the permanent magnet.

An object of the present invention is to provide a rotor of an interior permanent magnet rotary machine and the rotary machine that are capable of preventing a permanent magnet from rattling or being displaced while increasing the useful magnetic flux.

Solutions to the Problems

An aspect of the present invention is a rotor of a rotary machine, the rotor including: a shaft being a rotation axis of the rotor; and a rotating body provided with the shaft, wherein the rotating body includes: a plurality of divided cores formed by laminating a plurality of first electric steel sheets, the plurality of divided cores being arranged in a circumferential direction, corresponding to a rotation direction of the rotor, with respect to a center of the shaft; a plurality of permanent magnets equal in number to the number of the plurality of divided cores, the plurality of permanent magnets being arranged in the circumferential direction, alternating with the plurality of divided cores; and a covering portion made of resin, the covering portion covering the plurality of permanent magnets, the plurality of permanent magnets is in surface contact with side surfaces of the divided cores in the circumferential direction in a state where facing magnetic pole faces of two permanent magnets arranged on both sides of each divided core in the circumferential direction are homopolar, the covering portion includes: a ring-shaped first part covering end surfaces of the plurality of permanent magnets on a first side in a lamination direction in which the plurality of first electric steel sheets is laminated; a ring-shaped second part covering end surfaces of the plurality of permanent magnets on a second side opposite to the first side in the lamination direction; a plurality of third parts that are equal in number to the number of the plurality of permanent magnets, correspond to the plurality of respective permanent magnets, are each provided between two divided cores adjacent to each other in the circumferential direction, and cover outer peripheral surfaces of the plurality of permanent magnets on an outer peripheral side in a radial direction with respect to the center of the shaft; and a cylindrical fourth part covering inner peripheral surfaces of the plurality of divided cores on an inner peripheral side in the radial direction, and inner peripheral surfaces of the plurality of permanent magnets on the inner peripheral side in the radial direction, in the covering portion, the first part, the second part, the plurality of third parts, and the fourth part are integrated with one another, and in the plurality of divided cores, outer peripheral surfaces of the divided cores on the outer peripheral side in the radial direction are exposed without being covered by the covering portion.

According to this rotor, the plurality of permanent magnets can be restrained by the covering portion. The plurality of permanent magnets can be prevented from moving in the radial direction and the lamination direction. In a rotor of a rotary machine, for example, the rotating body may have the following structure. The previously-described structure is a structure where parts of a rotor core provided on both sides of a permanent magnet in the circumferential direction are coupled by a coupling portion in the entire region in the lamination direction. The coupling portion, together with the previously-described parts of the rotor core, is formed of an electric steel sheet in the entire region in the lamination direction. However, in such a structure, magnetic flux from the permanent magnet flows through the previously-described coupling portion. In other words, a part of the magnetic flux from the permanent magnet becomes leakage magnetic flux. In the rotating body in the above rotor, the plurality of divided cores is not coupled by a magnetic material. Therefore, the leakage magnetic flux can be reduced. The distance between outer peripheral surfaces of the plurality of divided cores and an inner peripheral surface of a stator of the rotary machine can be reduced.

In the rotor, the rotating body may include a support portion provided on the inner peripheral side of the fourth part in the radial direction, the support portion supporting the shaft. According to the configuration, the shaft can be integrated with the rotating body via the support portion provided on the fourth part.

In the rotor, the rotating body may include a first ring-shaped core formed of a ring-shaped second electric steel sheet, the first ring-shaped core being in a state where the second electric steel sheet, together with the plurality of first electric steel sheets, is laminated in the lamination direction in the plurality of divided cores, the first ring-shaped core may include: a plurality of first core portions equal in number to the number of the plurality of divided cores, the plurality of first core portions being arranged at positions same as the positions of the plurality of divided cores in the circumferential direction and the radial direction; and a first coupling portion integral with the plurality of first core portions, the first coupling portion coupling the plurality of first core portions in the circumferential direction, the first coupling portion may be provided on an inner peripheral part of the first ring-shaped core, and the first ring-shaped core may be provided on end surfaces of the plurality of divided cores on one of the first side and the second side in the lamination direction, and may not be provided on end surfaces of the plurality of divided cores on the other of the first side and the second side in the lamination direction. In this case, the first ring-shaped core may be provided at a position between the end surface of each of the plurality of divided cores on the first side in the lamination direction and the end surface of each of the plurality of divided cores on the second side in the lamination direction, the position being identical in the lamination direction among the plurality of divided cores, and may be in a state where the second electric steel sheet is sandwiched between predetermined two of the plurality of first electric steel sheets in the plurality of divided cores. In addition, in the rotor, the rotating body may include a first ring-shaped core formed of a ring-shaped second electric steel sheet, the first ring-shaped core being in a state where the second electric steel sheet, together with the plurality of first electric steel sheets, is laminated in the lamination direction in the plurality of divided cores, the first ring-shaped core may include: a plurality of first core portions equal in number to the number of the plurality of divided cores, the plurality of first core portions being arranged at positions same as the positions of the plurality of divided cores in the circumferential direction and the radial direction; and a first coupling portion integral with the plurality of first core portions, the first coupling portion coupling the plurality of first core portions in the circumferential direction, the first coupling portion may be provided on an inner peripheral part of the first ring-shaped core, and the first ring-shaped core may be provided at a position between an end surface of each of the plurality of divided cores on the first side in the lamination direction and an end surface of each of the plurality of divided cores on the second side in the lamination direction, the position being identical in the lamination direction among the plurality of divided cores, and may be in a state where the second electric steel sheet is sandwiched between predetermined two of the plurality of first electric steel sheets in the plurality of divided cores.

According to each of the above-described configurations, the plurality of divided cores can be coupled by the first ring-shaped core. At the time of manufacturing the rotating body, the plurality of divided cores can be handled in an integrated state. The first electric steel sheet and the second electric steel sheet may be electric steel sheets of the same material, or electric steel sheets of different materials in terms of the material. The first electric steel sheet and the second electric steel sheet may be electric steel sheets with the same thickness, or electric steel sheets with different thicknesses.

In the rotor, the rotating body may include a second ring-shaped core formed of a ring-shaped third electric steel sheet, the second ring-shaped core being in a state where the third electric steel sheet, together with the plurality of first electric steel sheets, is laminated in the lamination direction in the plurality of divided cores, the second ring-shaped core may include: a plurality of second core portions equal in number to the number of the plurality of divided cores, the plurality of second core portions being arranged at positions same as the positions of the plurality of divided cores in the circumferential direction and the radial direction; and a second coupling portion integral with the plurality of second core portions, the second coupling portion coupling the plurality of second core portions in the circumferential direction, and the second coupling portion may be provided on an outer peripheral part of the second ring-shaped core. In this case, in the rotor, the second ring-shaped core may be provided on end surfaces of the plurality of divided cores on one of the first side and the second side in the lamination direction. Furthermore, in the rotor, the second ring-shaped core may be provided on end surfaces of the plurality of divided cores on the other of the first side and the second side in the lamination direction. In addition, in the rotor, the second ring-shaped core may be provided at a position between the end surface of each of the plurality of divided cores on the first side in the lamination direction and the end surface of each of the plurality of divided cores on the second side in the lamination direction, the position being identical in the lamination direction among the plurality of the divided cores, and may be in a state where the third electric steel sheet is sandwiched between predetermined two of the plurality of first electric steel sheets in the plurality of divided cores.

According to each of the above-described configurations, the plurality of divided cores can be coupled by the second ring-shaped core. At the time of manufacturing the rotating body, the plurality of divided cores can be handled in an integrated state. The first electric steel sheet and the third electric steel sheet may be electric steel sheets of the same material or electric steel sheets of different materials in terms of the material. The first electric steel sheet and the third electric steel sheet may be electric steel sheets with the same thickness, or electric steel sheets with different thicknesses.

Another aspect of the present invention is a rotary machine including any of the above-described rotors, and a stator. According to this rotary machine, the rotary machine having the above-described functions can be obtained.

Advantageous Effects of the Invention

According to the present invention, it is possible to obtain a rotor of an interior permanent magnet rotary machine and the rotary machine that are capable of preventing a permanent magnet from rattling or being displaced, while increasing the useful magnetic flux.

DESCRIPTION OF EMBODIMENTS

Embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the configurations described below, and various configurations can be employed based on the same technical idea. For example, a part of the configurations shown below may be omitted or may be replaced with another configuration or the like. Another configuration may be included.

A motor10as a rotary machine is described with reference toFIGS. 1 to 3.

The motor10is mounted in various products. The motor10is used as, for example, a drive source that rotates a fan included in an air conditioner. In addition, the motor10is used as a drive source of a compressor. Furthermore, the motor10is used as a drive source of an electric vehicle. An electric car, an electric bicycle, an electric wheelchair, an electric cart, or an electric food trolley are examples of the electric vehicle. The electric car includes a hybrid car. The motor10is an interior permanent magnet brushless motor. The motor10is the brushless motor of an inner rotation type. The motor10includes a stator20, a rotor30, bearings60and61, and brackets62and63(seeFIGS. 1 and 2). InFIGS. 1 and 2, the brackets62and63are indicated by two-dot chain lines.

The stator20includes a stator core21, a plurality of coils24, an insulator25, a connector26, and a mold portion28(seeFIGS. 1 to 3). The stator core21is formed by, for example, while an electric steel sheet being a material is punched with a press machine, laminating the punched electric steel sheets of a predetermined shape. In an embodiment, a direction in which first electric steel sheets punched out from the electric steel sheet being the material are laminated is referred to as a “lamination direction.” The first electric steel sheets form divided cores33of the rotor30. The first electric steel sheets and the divided cores33are described below. Both sides in the lamination direction are referred to as a “first side” and a “second side.” In the embodiment, the electric steel sheets of the predetermined shape punched out by the press machine are sequentially laminated on the first side in the lamination direction, after being punched out. A direction in which the punched out electric steel sheets are laminated in the stator core21agrees with the lamination direction. In other words, the direction in which the electric steel sheets are laminated in the stator core21and the direction in which the first electric steel sheets are laminated in the divided cores33are the same direction (lamination direction) in the motor10.

The stator core21includes a yoke22and a plurality of teeth23(seeFIG. 3). In the stator core21, the plurality of teeth23protrudes at equiangular intervals from the yoke22toward the rotor30side. Each coil24is provided to the corresponding tooth23. The coil24is formed by winding a conducting wire around the tooth23. At the time of forming the coil24, the insulator25is mounted on the stator core21. The insulator25electrically insulates the stator core21and the coil24from each other.

In the motor10exemplarily described in the embodiment, the number of the teeth23in the stator core21is 12. Therefore, the stator20includes 12 coils24. The12coils24are classified into the coils24of the U phase, the V phase, and the W phase. In four coils24of the same phase, a crossover connects the coils24. The crossover is formed of the conducting wire forming the coils24. The coils24of each phase are connected in a predetermined system. For example, the coils24of each phase are star-connected. In a case of the star connection, a first lead wire of two lead wires of the coils24of each phase is connected to form a neutral point. A second lead wire of the two lead wires of the coils24of each phase is connected to a terminal27of the corresponding phase of the connector26. The second lead wire and the terminal27may be connected via a connection member such as a printed circuit board or a bus bar. InFIGS. 1 to 3, illustrations of the crossovers and illustrations of the first lead wire and the second lead wire are omitted. InFIG. 3, illustrations of the bearings60and61and the brackets62and63and illustrations of the connector26and the mold portion28are omitted.

The stator core21in the following state, together with the connector26including the terminals27to which the second lead wires are connected, is set in a state of being positioned in a mold of an injection molding machine. The stator core21in the previously-described state is a state where the coils24are provided via the insulator25. The mold portion28is formed by resin molding with the injection molding machine. BMC (Bulk Molding Compound) is exemplarily described as the previously-described resin material. The mold portion28covers the stator core21that is provided with the coils24via the insulator25(seeFIGS. 1 and 2). However, an inner peripheral surface of each tooth23is exposed from the mold portion28(seeFIG. 2). The inner peripheral surface of the tooth23is a surface, which faces the rotor30(an outer peripheral surface of a rotating body32described below), of the tooth23. In the motor10, an outer peripheral part of the stator core21is also exposed from the mold portion28.

The connector26is provided to the mold portion28. The connector26protrudes from the mold portion28. The mold portion28is provided with the brackets62and63. The bracket62is fixed to the mold portion28on the first side in the lamination direction. The bracket63is fixed to the mold portion28on the second side in the lamination direction. For example, the bracket62is fixed to the mold portion28in a state where an outer peripheral portion is buried in the mold portion28. In this case, the above-described resin molding is performed in a state where the bracket62, together with the stator core21and the connector26, is set in the mold of the injection molding machine. The bracket63is screwed to an end surface of the mold portion28on the second side in the lamination direction. However, the brackets62and63may be fixed to the mold portion28by a method different from the previously-described method. Except for a plurality of through-holes formed in the bracket63through which screws for fastening pass, an illustration of the previously-described configuration for fastening with screws is omitted inFIG. 2. The stator20is similar to a stator of a motor (rotary machine) that is already in practical use. Therefore, the other descriptions related to the stator20are omitted.

The rotor30is described with reference toFIGS. 1 to 6. The rotor30includes a shaft31and the rotating body32(seeFIGS. 1 to 3). The rotating body32includes a plurality of divided cores33, a plurality of permanent magnets45, a support portion46, and a covering portion50(seeFIG. 4). In the rotor30, the number of the divided cores33is equal to the number of the permanent magnets45. In the motor10exemplarily described in the embodiment, the number of the divided cores33and the number of the permanent magnets45are both14.

The shaft31is provided to the rotating body32(seeFIGS. 1 to 3). The shaft31is provided with the bearings60and61across the rotating body32in the lamination direction. The bearing60is provided on the first side in the lamination direction. The bearing61is provided on the second side in the lamination direction. In the motor10, the bracket62supports the bearing60on the first side in the lamination direction, and the bracket63supports the bearing61on the second side in the lamination direction. Consequently, in the motor10, the shaft31serves as a rotation axis of the rotor30, and the rotor30is rotatably supported. In the embodiment, a circumferential direction with respect to a center C of the shaft31is referred to as a “circumferential direction.” The circumferential direction corresponds to the rotation direction of the rotor30. A radial direction with respect to the center C of the shaft31is referred to as a “radial direction.” In the rotor30, the shaft31is attached to a center portion of the rotating body32in the radial direction. A side closer to the center C of the shaft31in the radial direction is referred to as an “inner peripheral side,” and a side away from the center C in the radial direction is referred to as an “outer peripheral side.” For example, an inner peripheral surface or an inner peripheral part of a certain configuration is a surface or a part of the previously-described configuration on the inner peripheral side in the radial direction. An outer peripheral surface or an outer peripheral part of a certain configuration is a surface or a part of the previously-described configuration on the outer peripheral side in the radial direction. In the motor10, the center C of the shaft31is along the lamination direction. A dot-and-dash line to which a reference sign C is assigned inFIG. 1is a straight line corresponding to the center C of the shaft31.

The plurality of divided cores33is arranged at equiangular intervals in the circumferential direction (seeFIG. 4). The plurality of divided cores33forms a rotor core. Two projection portions36are provided to each divided core33. The two projection portions36are formed on both side parts of the divided core33in the circumferential direction on the outer peripheral side of the rotating body32in the radial direction. The divided core33is formed by laminating the first electric steel sheets in the lamination direction. The first electric steel sheets have a fan-like shape. The divided core33is formed by, while an electric steel sheet being a material is punched into a fan shape with a press machine, laminating the fan-shaped first electric steel sheets. To fix a plurality of first electric steel sheets, for example, a method referred to as “caulking” is employed. In the field of rotary machines, the previously-described fixing method is also referred to as, for example, “twining”.

An example where the plurality of first electric steel sheets is fixed by caulking is described with reference toFIG. 5. This description will be made, given the following points. Each divided core33is formed by laminating M first electric steel sheets. Among the plurality of first electric steel sheets forming the divided core33, the first electric steel sheet provided at an end on the second side in the lamination direction is set to be the first sheet, and the following first electric steel sheets are set to be the second, the third, . . . , and the M-th sheets. The M-th first electric steel sheet is the first electric steel sheet provided at an end on the first side in the lamination direction of the plurality of first electric steel sheet forming the divided core33.

When the plurality of first electric steel sheets is fixed by caulking, the second and subsequent first electric steel sheet includes protrusions37. The protrusions37are provided at predetermined fixed positions on an end surface of the first electric steel sheet on the second side in the lamination direction. Each protrusion37protrudes toward the second side in the lamination direction. The protrusion37is formed by plastically deforming the first electric steel sheet. In each divided core33, the protrusions37are formed in two places. A recess38corresponding to each protrusion37is formed at a position opposite to the protrusion37on an end surface of the first electric steel sheet on the first side in the lamination direction. The protrusion37and the recess38are formed at a timing when each of the second and subsequent first electric steel sheets is punched out from the electric steel sheet being the material. The protrusions37and the recesses38are not formed for the first first electric steel sheet. Parts at the previously-described fixed positions are punched out from the first first electric steel sheet to be hole portions39penetrating in the lamination direction. Each hole portion39is formed at a timing when the first first electric steel sheet is punched out from the electric steel sheet being the material. The protrusions37and the recesses38, and the hole portions39, which are illustrated inFIG. 5, are exemplifications, and may have different shapes from those inFIG. 5. One or both of the numbers and the arrangements of the protrusions37and the recesses38, and the hole portions39may also be designed to be different from those inFIG. 5.

The protrusions37formed on the second first electric steel sheet are fitted into the hole portions39formed in the first first electric steel sheet (see “<second lamination>” inFIG. 5). Consequently, the first first electric steel sheet and the second first electric steel sheet are fixed. Next, the protrusions37formed on the third first electric steel sheet are fitted into the recesses38formed in the second first electric steel sheet (see “<third lamination>” inFIG. 5). Consequently, the second first electric steel sheet and the third first electric steel sheet are fixed. The fourth and subsequent first electric steel sheets are also fixed similarly to the second and third first electric steel sheets. Lastly, the protrusions37formed on the M-th first electric steel sheet are fitted into the recesses38formed in the M−1-th first electric steel sheet (see “<M-th lamination>” inFIG. 5). Consequently, the divided core33where the M number of first electric steel sheets have been laminated is manufactured.

Each permanent magnet45is a rare-earth magnet. However, the permanent magnet45may be a magnet of another material. The permanent magnet45may be, for example, a ferrite magnet. The permanent magnet45has a plate-like cuboid shape (seeFIG. 4). The plurality of permanent magnets45is arranged at equiangular intervals in the circumferential direction. In other words, the plurality of permanent magnets45and the plurality of divided cores33are alternately arranged in the circumferential direction. In the embodiment, the state where the plurality of divided cores33and the plurality of permanent magnets45are alternately arranged in the circumferential direction is referred to as an “arranged state.” Each of the plurality of permanent magnets45is in surface contact with side surfaces of the divided cores33in the circumferential direction in a state where the following magnetic pole faces are homopolar. Each of the previously-described magnetic pole faces is a side surface, which faces each other, of two permanent magnets45arranged on both sides of the divided core33in the circumferential direction. As for one predetermined permanent magnet45of the plurality of permanent magnets45in the arranged state, when the magnetic polarity of the magnetic pole face on a third side in the circumferential direction is the N pole, the magnetic polarity of the magnetic pole face on a fourth side in the circumferential direction is the S pole. The fourth side in the circumferential direction is opposite to the third side. In the embodiment, a description is given without specifying the third side and the fourth side in the circumferential direction. Each permanent magnet45sandwiched between two divided cores33adjacent to each other in the circumferential direction in the arranged state is in contact at corner portions on the outer peripheral side in the radial direction with surfaces of the projection portions36of the two divided cores33on the inner peripheral side in the radial direction. In the divided core33and the permanent magnet45, dimensions H1and H2are set to be the same. The dimension H1is the dimension of the divided core33in the lamination direction, and the dimension H2is the dimension of the permanent magnet45in the lamination direction (seeFIG. 4).

The support portion46is a cylindrical member where a through-hole47penetrating in the lamination direction is formed (seeFIG. 4). The support portion46is made of, for example, metal. The support portion46is provided to a center portion of the rotating body32in the radial direction. The support portion46supports the shaft31(seeFIG. 2). In other words, the shaft31is fitted through the through-hole47, and is fixed to the support portion46. The shaft31is fixed to the rotating body32. The shaft31is integrated with the rotating body32. Consequently, the rotor30is formed.

The covering portion50covers the plurality of permanent magnets45(seeFIG. 4). The covering portion50does not have magnetic properties. The covering portion50is made of resin. BMC is exemplarily described as the resin material forming the covering portion50. However, the covering portion50may be formed of a resin material different from BMC. The resin material forming the covering portion50is determined as appropriate, considering various conditions. The covering portion50is, for example, formed integrally by resin molding with an injection molding machine (see the upper row ofFIG. 6). At the time of resin molding the covering portion50, the plurality of divided cores33, the plurality of permanent magnets45, and the support portion46are set in a state of being positioned in a mold of the injection molding machine. In this case, the plurality of divided cores33and the plurality of permanent magnets45are in the arranged state in the mold and furthermore the support portion46is placed in a center portion in the radial direction of the plurality of divided cores33and the plurality of permanent magnets45in the arranged state (see “arranged state” inFIG. 4). Resin is then injected into the mold to form the integrated covering portion50.

The covering portion50includes a first part51, a second part52, a plurality of third parts53, and a fourth part54(see the lower row ofFIG. 6). The first part51, the second part52, the plurality of third parts53, and the fourth part54are integrated with one another (see the upper row ofFIG. 6). The lower row ofFIG. 6indicates the first part51, the second part52, the plurality of third parts53, and the fourth part54in a separated state for convenience of description. The first part51is a part of the covering portion50provided on the first side in the lamination direction. The first part51has a ring shape where a through-hole56is formed in the center in the radial direction. The first part51covers end surfaces of the plurality of permanent magnets45on the first side in the lamination direction. Furthermore, the first part51covers end surfaces of the plurality of divided cores33on the first side in the lamination direction. The second part52is a part of the covering portion50provided on the second side in the lamination direction. The second part52has a ring shape where a through-hole57is formed in the center in the radial direction. The second part52covers end surfaces of the plurality of permanent magnets45on the second side in the lamination direction. Furthermore, the second part52covers end surfaces of the plurality of divided cores33on the second side in the lamination direction.

The plurality of third parts53is linked to the first part51, and is linked to the second part52. In other words, the plurality of third parts53is integral at end portions on the first side in the lamination direction with an outer peripheral part of the first part51, and is integral at end portions on the second side in the lamination direction with an outer peripheral part of the second part52. The plurality of third parts53is provided at equiangular intervals in the circumferential direction, corresponding to the plurality of permanent magnets45, on the outer peripheral side in the radial direction. In other words, the covering portion50includes the third parts53equal in number to the number of the plurality of permanent magnets45. The plurality of third parts53correspond to the plurality of permanent magnets45and are each provided between two projection portions36, which face each other in the circumferential direction, of two divided cores33adjacent to each other in the circumferential direction. The plurality of third parts53covers outer peripheral surfaces of the plurality of permanent magnets45. In the rotor30, between the previously-described two projection portions36, is a gap along the lamination direction. Therefore, the third parts53each have a columnar shape along the lamination direction. Outer peripheral surfaces of the plurality of third parts53, together with outer peripheral surfaces of the plurality of divided cores33, form the outer peripheral surface of the rotating body32. The outer peripheral surface of each third part53may have the same shape as the outer peripheral surface of each divided core33. If the outer peripheral surface of the divided core33and the outer peripheral surface of the third part53are set to be, for example, curved surfaces with the same radius of curvature, the outer peripheral surface of the rotating body32is a circular cylindrical surface.

The fourth part54is linked to the first part51, and is linked to the second part52. In other words, the fourth part54is integral at an end portion on the first side in the lamination direction with an inner peripheral part of the first part51, and is integral at an end portion on the second side in the lamination direction with an inner peripheral part of the second part52. The fourth part54is provided in a space between the following inner peripheral surface and an outer peripheral surface of the support portion46. The previously-described inner peripheral surface is a cylindrical surface formed of inner peripheral surfaces of the plurality of divided cores33and inner peripheral surfaces of the plurality of permanent magnets45. Therefore, the fourth part54has a cylindrical shape where a through-hole58has been formed in the center in the radial direction. An outer peripheral surface of the fourth part54covers the inner peripheral surfaces of the plurality of divided cores33and the inner peripheral surfaces of the plurality of permanent magnets45, and an inner peripheral surface thereof fixes the support portion46. In the covering portion50, the through-hole56of the first part51, the through-hole58of the fourth part54, and the through-hole57of the second part52are continuous in the lamination direction. Therefore, the covering portion50includes one through-hole55formed with the through-holes56,58, and57in a center portion in the radial direction.

Advantageous Effects of Embodiment

According to the embodiment, the following effects can be obtained.

(1) In the rotating body32of the rotor30, the plurality of divided cores33and the plurality of permanent magnets45are alternately arranged in the circumferential direction (seeFIG. 4). The plurality of permanent magnets45is in the following state in the rotating body32. The previously-described state is a state where facing magnetic pole faces of two permanent magnets45arranged on both sides of each divided core33in the circumferential direction are homopolar. Each permanent magnet45is in surface contact with a side surface of the divided core33in the circumferential direction. The covering portion50includes the first part51, the second part52, the plurality of third parts53, and the fourth part54(seeFIG. 6). In the covering portion50, the first part51, the second part52, the plurality of third parts53, and the fourth part54are integrated with one another. The first part51covers the end surfaces of the plurality of permanent magnets45on the first side in the lamination direction. The second part52covers the end surfaces of the plurality of permanent magnets45on the second side in the lamination direction. The plurality of third parts53covers the outer peripheral surfaces of the plurality of permanent magnets45. The fourth part54covers the inner peripheral surfaces of the plurality of divided cores33and the inner peripheral surfaces of the plurality of permanent magnets45. In other words, in the rotating body32, the plurality of permanent magnets45and the plurality of divided cores33are alternately arranged in the circumferential direction, and the covering portion50covers the plurality of permanent magnets45arranged in this manner (seeFIG. 4). In the rotating body32, the outer peripheral surfaces of the plurality of divided cores33are exposed without being covered by the covering portion50.

Hence, the covering portion50can restrain the plurality of permanent magnets45. The plurality of permanent magnets45can be prevented from moving in the radial direction and the lamination direction. In a rotor of a rotary machine, for example, it is also possible to cause a rotating body to have the following structure. The previously-described structure is a structure where parts of a rotor core provided on both sides of a permanent magnet in the circumferential direction are coupled by a coupling portion in the entire region in the lamination direction. The coupling portion, together with the previously-described parts of the rotor core, is formed of an electric steel sheet in the entire region in the lamination direction. However, in such a structure, magnetic flux from the permanent magnet flows through the previously-described coupling portion. In other words, a part of the magnetic flux from the permanent magnet becomes leakage magnetic flux. In the rotating body32in the rotor30, the plurality of divided cores33is not coupled by a magnetic material. Therefore, the leakage magnetic flux can be reduced. The distance between the outer peripheral surfaces of the plurality of divided cores33and the inner peripheral surfaces of the teeth23can be reduced.

Although description is omitted in the above, the plurality of divided cores33, together with the plurality of permanent magnets45, is fixed by the covering portion50in the rotating body32. In other words, in each divided core33where the plurality of first electric steel sheets is fixed by caulking, the recesses38are present in the end surface on the first side in the lamination direction, and recesses40are present in the end surface on the second side in the lamination direction (seeFIGS. 4 and 5). The recesses40are formed in the previously-described end surface in a state where the protrusions37on the second first electric steel sheet are fitted in the hole portions39(seeFIG. 5). At the time of resin molding the covering portion50, the resin material forming the covering portion50fills the recesses38and40formed in the end surfaces of the plurality of divided cores33on the first side and the second side in the lamination direction. The first part51including the parts of the resin filling the recesses38restrains the plurality of divided cores33on the first side in the lamination direction. The second part52including the parts of the resin filling the recesses40restrains the plurality of divided cores33on the second side in the lamination direction. The first part51and the second part52prevent the plurality of divided cores33from moving in the lamination direction. Furthermore, the first part51and the second part52prevent the plurality of divided cores33from moving in the radial direction, and prevent the plurality of divided cores33from moving in the circumferential direction. The movement of the plurality of divided cores33toward the inner peripheral side in the radial direction is also prevented by the fourth part54. The movement of the plurality of divided cores33in the circumferential direction is also prevented by the plurality of permanent magnets45, and is also prevented by the plurality of third parts53in contact with two projection portions36adjacent to each other in the circumferential direction.

(2) The rotating body32includes the support portion46(seeFIG. 4). The support portion46supports the shaft31(seeFIG. 2). Hence, the shaft31is integrated with the rotating body32via the support portion46(seeFIGS. 1 to 3).

The embodiment can also be configured as follows. Some configurations of modifications described below may also be employed in combination as appropriate. In the following description, points different from the above description are described, and description of similar points is omitted as appropriate.

(1) The rotary machine has been described, taking the motor10as an example. The above structure can also be employed for a rotor of an electrical generator as the rotary machine. In other words, in the rotor of the electrical generator, a rotating body includes a covering portion as in the above description (seeFIGS. 4 and 6). In the rotating body, a plurality of permanent magnets and a plurality of divided cores are alternately arranged in the circumferential direction, and the covering portion covers the plurality of permanent magnets arranged in this manner

(2) Each divided core33is formed by laminating the plurality of first electric steel sheets (seeFIG. 4). In the divided core33, the plurality of first electric steel sheets is fixed by caulking (seeFIG. 5). A method different from caulking may be employed as the method for fixing the plurality of first electric steel sheets. For example, a fixing method such as bonding or welding may be employed as the method for fixing the plurality of first electric steel sheets. In the fixing method by bonding, the plurality of first electric steel sheets is fixed with an adhesive. In the fixing method by welding, the plurality of first electric steel sheets is welded. The fixing methods by bonding and welding are techniques that are already in practical use. Hence, any other descriptions related to the fixing of the plurality of first electric steel sheets by bonding and welding are omitted.

When the plurality of first electric steel sheets is bonded or welded, the above-described recesses38and40are not formed in the divided core. Therefore, in the divided core, a recess corresponding to each recess38may be formed in an end surface on the first side in the lamination direction, and a recess corresponding to each recess40may be formed in an end surface on the second side in the lamination direction. A through-hole penetrating the divided core in the lamination direction may be formed. The resin material forming the covering portion50fills the previously-described recesses or through-hole. The divided core may be provided on the inner peripheral side in the radial direction with a part buried in the fourth part54of the covering portion50irrespective of the method for fixing the plurality of first electric steel sheets. In this case, a convex portion or concave portion may be formed on the previously-described part buried in the fourth part54. The convex portion is engaged with the resin material forming the fourth part54inside the fourth part54. The resin material forming the fourth part54enters the concave portion inside the fourth part54. According to each of the previously-described configurations, the covering portion50restrains the plurality of divided cores to enable the prevention of the movement of the plurality of divided cores in one or all of the lamination direction, the radial direction, and the circumferential direction.

(3) In the rotor30, the rotating body32is formed of the plurality of divided cores33, the plurality of permanent magnets45, the support portion46, and the covering portion50(seeFIG. 4). The rotating body32may be provided with a first ring-shaped core70(seeFIGS. 7 to 12). The first ring-shaped core70couples the plurality of divided cores33. The rotating body32may be provided with a second ring-shaped core75(seeFIGS. 13 to 16). The second ring-shaped core75couples the plurality of divided cores33. According to the first ring-shaped core70or the second ring-shaped core75, the plurality of divided cores33can be handled in an integrated state at the time of manufacturing the rotating body32. The first ring-shaped core70is formed of a second electric steel sheet. The second electric steel sheet is formed using the same electric steel sheet as the first electric steel sheet as a material. The second ring-shaped core75is formed of a third electric steel sheet. The third electric steel sheet is formed using the same electric steel sheet as the first electric steel sheet as a material. The second electric steel sheet and the third electric steel sheet are formed by punching, for example, the electric steel sheet being the material with the press machine, similarly to the first electric steel sheet. However, some or all of the first electric steel sheet, the second electric steel sheet, and the third electric steel sheet may use, as materials, electric steel sheets that are different from each other in one or both of material and thickness.

An integrated laminate where the plurality of divided cores33is coupled by the first ring-shaped core70or the second ring-shaped core75in the rotating body32is described below, taking six aspects of a first aspect to a sixth aspect as examples. In the descriptions of the first aspect to the sixth aspect, the names and the reference signs of portions are same as above to clarify the correspondence with the above-described portions illustrated inFIGS. 1 to 6. However, the previously-described laminate is referred to as a “coupled core41.” The first aspect (seeFIGS. 7 to 10), the second aspect (seeFIG. 11), and the third aspect (seeFIG. 12) relate to the coupled core41where the plurality of divided cores33is coupled by the first ring-shaped core70. The fourth aspect (seeFIGS. 13 and 14), the fifth aspect (seeFIG. 15), and the sixth aspect (seeFIG. 16) relate to the coupled core41where the plurality of divided cores33is coupled by the second ring-shaped core75.

The first aspect to the third aspect are different in the position of the first ring-shaped core70provided to the plurality of divided cores33. The first aspect includes two configurations of a first example (seeFIGS. 7 and 8) and a second example (seeFIGS. 9 and 10). The third aspect is an example where the first example of the first aspect and the second aspect are combined. In the third aspect, the first ring-shaped core70is provided at the position of each first ring-shaped core70provided in the first example of the first aspect and the second aspect. The fourth aspect to the sixth aspect are different in the position of the second ring-shaped core75provided to the plurality of divided cores33. The sixth aspect is an example where the fourth aspect and the fifth aspect are combined. In the sixth aspect, the second ring-shaped core75is provided at the position of each second ring-shaped core75provided in the fourth aspect and the fifth aspect. In this modification, the first aspect is described first, and then the second aspect to the sixth aspect are sequentially described. In each of the descriptions of the second aspect to the sixth aspect, descriptions of points common to the first aspect to the fifth aspect that are already described are omitted as appropriate. In each of the descriptions of the first aspect to the sixth aspect, each component with the same name, to which the same reference sign is assigned, indicates a predetermined component in a description target aspect. This is also the same with a case where a description is given, distinguishing the first example and the second example in the first aspect.

The coupled core41of the first example and the second example of the first aspect is described with reference toFIGS. 7 to 10. The coupled core41of the first aspect includes the plurality of divided cores33and one first ring-shaped core70(seeFIGS. 7 and 9). In the coupled core41, the first ring-shaped core70is provided on end surfaces of the plurality of divided cores33on one of the first side and the second side in the lamination direction, and is not provided on end surfaces of the plurality of divided cores33on the other of the first side and the second side in the lamination direction. The first ring-shaped core70is formed of the ring-shaped second electric steel sheet. The first ring-shaped core70may be formed by laminating a plurality of second electric steel sheets. In this modification, the first ring-shaped core70is formed by laminating two second electric steel sheets. The number of the second electric steel sheets forming the first ring-shaped core70is determined as appropriate, considering various conditions. In the coupled core41, the first ring-shaped core70is in the following state. The previously-described state is a state where the second electric steel sheets, together with a plurality of first electric steel sheets, are laminated in the lamination direction in the plurality of divided cores33.

The first ring-shaped core70includes a plurality of first core portions71and a first coupling portion72(seeFIGS. 7 and 9). The number of the first core portions71in the first ring-shaped core70is equal to the number of the divided cores33. In other words, when the number of the divided cores33is 14, the first ring-shaped core70includes 14 first core portions71. The plurality of first core portions71is arranged at positions same as those of the plurality of divided cores33in the circumferential direction and the radial direction. Each first core portion71has a shape corresponding to the shape of each divided core33when viewed in the lamination direction. Therefore, in the coupled core41, the plurality of first core portions71is superposed in the lamination direction in alignment with the plurality of divided cores33. The first coupling portion72is provided to an inner peripheral part of the first ring-shaped core70. The first coupling portion72is integral at the inner peripheral part of the first ring-shaped core70with the plurality of first core portions71, and couples the plurality of first core portions71in the circumferential direction.

The first example of the first aspect is described below with reference toFIGS. 7 and 8. The second example of the first aspect is then described with reference toFIGS. 9 and 10. In the description of the second example, a description of points common with the first example is omitted as appropriate. In the first example of the first aspect, the coupled core41includes the first ring-shaped core70on the end surfaces of the plurality of divided cores33on the first side in the lamination direction. In the second example of the first aspect, the coupled core41includes the first ring-shaped core70on the end surfaces of the plurality of divided cores33on the second side in the lamination direction.

First Example

The coupled core41of the first example is formed by, for example, the following manufacturing method including a first step and a second step. In the first step, the plurality of first electric steel sheets equal in number to the number of the plurality of divided cores33is punched out from the electric steel sheet being the material. The plurality of first electric steel sheets may be simultaneously punched out from the electric steel sheet being the material. This applies at the time of manufacturing the divided cores33(seeFIG. 4) in the above-described embodiment. In this modification, the plurality of first electric steel sheets is assumed to be simultaneously punched out from the electric steel sheet being the material. The plurality of first electric steel sheets simultaneously punched out is laminated in a state of being arranged at the following positions. The previously-described positions are positions that agree with the arrangement of the plurality of divided cores33in the rotating body32. Simultaneous punching for the plurality of first electric steel sheets is repeated the number of times equal to the number of the first electric steel sheets in the divided core33. Pluralities of the first electric steel sheets simultaneously punched out in the second and later punching are sequentially laminated on the plurality of first electric steel sheets punched out previously. In the first step, the pluralities of the first electric steel sheets simultaneously punched out form the plurality of divided cores33. In the second step, a predetermined number of the second electric steel sheets are punched out from the electric steel sheet being the material. The second electric steel sheets are laminated on the plurality of first electric steel sheets simultaneously punched out last in the first step. In other words, the second electric steel sheets are punched out from the electric steel sheet being the material in the following state, and are laminated on the plurality of divided cores33formed in the first step. The previously-described state is a state where the plurality of divided cores33aligns with the plurality of first core portions71in the circumferential direction and the radial direction. In the second step, the second electric steel sheets form the first ring-shaped core70provided on the first side in the lamination direction.

In the coupled core41, the fixing of the first electric steel sheet and the second electric steel sheet laminated in the lamination direction employs caulking. When the first ring-shaped core70is formed of the plurality of second electric steel sheets, the following second electric steel sheet is laminated on the second electric steel sheet punched out previously. The previously-described second electric steel sheet is the second electric steel sheet punched out by the second and later punching in punching for the second electric steel sheet repeated the number of times equal to the number of the second electric steel sheets. The fixing of the plurality of second electric steel sheets also employs caulking. Caulking used to form the coupled core41is performed as in the case of the plurality of first electric steel sheets illustrated inFIG. 5. Hence, a description related to the previously-described caulking is omitted. In the coupled core41, the recesses38are formed in an end surface on the first side in the lamination direction on the first ring-shaped core70provided on the first side in the lamination direction.

In the rotating body32including the coupled core41, the dimension H1(seeFIG. 7) of each divided core33may be set to be the same as the dimension H2(seeFIG. 4) of each permanent magnet45, and the positions of the plurality of divided cores33in the lamination direction may be set to agree with the positions of the plurality of permanent magnets45in the lamination direction (see “arranged state” inFIG. 7). In this case, first spaces S1equal in number to the number of the permanent magnets45are formed in the following plurality of parts on the first side in the lamination direction (seeFIGS. 7 and 8). The previously-described plurality of parts is a plurality of parts each disposed between two first core portions71adjacent to each other in the circumferential direction in the plurality of first core portions71and on the first side in the lamination direction with respect to the end surfaces of the permanent magnets45on the first side in the lamination direction. InFIG. 8, areas of broken lines illustrated on the first side in the lamination direction correspond to the first spaces S1.

The resin material forming the first part51fills the plurality of first spaces S1. Consequently, first protruding portions P1equal in number to the number of the plurality of permanent magnets45are formed on the first part51. Each first protruding portion P1protrudes toward the second side in the lamination direction, and is fitted in the corresponding first space S1(seeFIG. 8). In the rotating body32, the linkage of the coupled core41and the covering portion50is improved. The stiffness of the rotating body32is increased. No permanent magnet45is provided in each first space S1. The occurrence of leakage magnetic flux via the first coupling portion72can be prevented. However, the dimension H2of each permanent magnet45may be set to be the same as a dimension H3. The dimension H3is the dimension of the coupled core41in the lamination direction (seeFIG. 7). In this case, no first space S1is formed. No first protruding portion P1is formed on the first part51.

In the first example, the first ring-shaped core70is not provided on the end surfaces of the plurality of divided cores33on the second side in the lamination direction. Therefore, a space corresponding to a second space S2is not formed on the second side in the lamination direction in the rotating body32. As a result, a protruding portion corresponding to a second protruding portion P2is not formed on the second part52in the rotating body32. The second part52has a shape as in the above description (seeFIGS. 6 and 8). The second space S2and the second protruding portion P2are described in the second example.

Second Example

The coupled core41of the second example is formed by, for example, the following manufacturing method including a first step and a second step. In the first step, a predetermined number of the second electric steel sheets are punched out from the electric steel sheet being the material. In the first step, the second electric steel sheets form the first ring-shaped core70provided on the second side in the lamination direction. In the second step, the plurality of first electric steel sheets equal in number to the number of the plurality of divided cores33is simultaneously punched out from the electric steel sheet being the material. The plurality of first electric steel sheets is simultaneously punched out in a state of being arranged at positions that agree with the arrangement of the plurality of divided cores33in the rotating body32, and is laminated on the second electric steel sheet punched out last in the first step. In other words, the plurality of first electric steel sheets simultaneously punched out is laminated on the plurality of first core portions71of the first ring-shaped core70formed in the first step, respectively. In the second step, pluralities of the first electric steel sheets simultaneously punched out form the plurality of divided cores33. In the coupled core41, the recesses40are formed in an end surface on the second side in the lamination direction on the first ring-shaped core70provided on the second side in the lamination direction.

In the rotating body32including the coupled core41, the dimension H1(seeFIG. 9) of the divided core33may be set to be the same as the dimension H2(seeFIG. 4) of the permanent magnet45, and the positions of the plurality of divided cores33in the lamination direction may be set to agree with the positions of the plurality of permanent magnets45in the lamination direction (see “arranged state” inFIG. 9). In this case, the second spaces S2equal in number to the number of the permanent magnets45are formed in the following plurality of parts on the second side in the lamination direction (seeFIG. 10). The previously-described plurality of parts is a plurality of parts each disposed between two first core portions71adjacent to each other in the circumferential direction in the plurality of first core portions71and on the second side in the lamination direction with respect to the end surface of the permanent magnet45on the second side in the lamination direction. InFIG. 10, areas of broken lines illustrated on the second side in the lamination direction correspond to the second spaces S2.

The resin material forming the second part52fills the plurality of second spaces S2. Consequently, the second protruding portions P2equal in number to the number of the plurality of permanent magnets45are formed on the second part52. Each second protruding portion P2protrudes toward the first side in the lamination direction, and is fitted in the second space S2(seeFIG. 10). In the rotating body32, the linkage of the coupled core41and the covering portion50is improved. The stiffness of the rotating body32is increased. No permanent magnet45is provided in the second space S2. The occurrence of leakage magnetic flux via the first coupling portion72can be prevented. However, the dimension H2of each permanent magnet45may be set to be the same as the dimension H3. The dimension H3is the dimension of the coupled core41in the lamination direction (seeFIG. 9). In this case, no second space S2is formed. No second protruding portion P2is formed on the second part52.

In the second example, the first ring-shaped core70is not provided on the end surfaces of the plurality of divided cores33on the first side in the lamination direction. Therefore, a space corresponding to each first space S1is not formed on the first side in the lamination direction in the rotating body32. As a result, a protruding portion corresponding to each first protruding portion P1is not formed on the first part51in the rotating body32. The first part51has a shape as in the above description (seeFIGS. 6 and 10).

The coupled core41of the second aspect is described with reference toFIG. 11. The coupled core41includes the plurality of divided cores33and one first ring-shaped core70. The first ring-shaped core70is provided at the following position in the lamination direction in the plurality of divided cores33in the coupled core41. The previously-described position is a position between the end surface of each of the plurality of divided cores33on the first side in the lamination direction and the end surface of each of the plurality of divided cores33on the second side in the lamination direction. Furthermore, the previously-described position is a position identical in the lamination direction among the plurality of divided cores33. Each divided core33is divided by the first ring-shaped core70into two parts in the lamination direction. In this modification, of the two divided parts of the divided core33, the part provided on the first side in the lamination direction is referred to as a “first piece34,” and the part provided on the second side in the lamination direction is referred to as a “second piece35.” The first piece34and the second piece35of each of the plurality of divided cores33sandwich the first ring-shaped core70from both sides in the lamination direction. Consequently, the first ring-shaped core70is in the following first state and second state. The first state is a state where the second electric steel sheets, together with the plurality of first electric steel sheets, are laminated in the lamination direction in the plurality of divided cores33. The second state is a state where the second electric steel sheets are sandwiched between predetermined two of the plurality of first electric steel sheets in the plurality of divided cores33. The previously-described two first electric steel sheets are the first electric steel sheet forming an end surface of the first piece34on the second side in the lamination direction, and the first electric steel sheet forming an end surface of the second piece35on the first side in the lamination direction. In the coupled core41, the plurality of first core portions71is superposed in the lamination direction in alignment with the plurality of divided cores33as in the coupled core41of the first aspect. In this modification, the first piece34and the second piece35have the same shape, the dimensions of which in the lamination direction are equal to each other. However, the position in the lamination direction, which divides each divided core33into two parts, is determined as appropriate, considering various conditions.

The coupled core41is formed by, for example, the following manufacturing method including a first step to a third step. In the first step, the plurality of first electric steel sheets equal in number to the number of the plurality of divided cores33is simultaneously punched out from the electric steel sheet being the material. The plurality of first electric steel sheets simultaneously punched out is laminated in a state of being arranged at the following positions. The previously-described positions are positions that agree with the arrangement of the plurality of divided cores33in the rotating body32. Simultaneous punching for the plurality of first electric steel sheets is repeated the number of times equal to the number of the first electric steel sheets in the second piece35. In the first step, pluralities of the first electric steel sheets simultaneously punched out form the plurality of second pieces35. In the second step, a predetermined number of the second electric steel sheets is punched out from the electric steel sheet being the material. The second electric steel sheets are laminated on the plurality of first electric steel sheets simultaneously punched out last in the first step. In other words, the second electric steel sheets are punched out from the electric steel sheet being the material in the following state, and are laminated on the plurality of second pieces35formed in the first step. The previously-described state is a state where the plurality of divided cores33(the plurality of second pieces35) align with the plurality of first core portions71in the circumferential direction and the radial direction. In the second step, the second electric steel sheets form the first ring-shaped core70provided between each first piece34and each second piece35. In the third step, the plurality of first electric steel sheets is simultaneously punched out again from the electric steel sheet being the material. The plurality of first electric steel sheets is simultaneously punched out in a state of being arranged at positions same as those in the case of the first step, and is laminated on the second electric steel sheet punched out last in the second step. In other words, the plurality of first electric steel sheets simultaneously punched out is laminated on the plurality of first core portions71of the first ring-shaped core70formed in the second step, respectively. Simultaneous punching for the plurality of first electric steel sheets is repeated the number of times equal to the number of the first electric steel sheets in the first piece34. In the third step, pluralities of the first electric steel sheets simultaneously punched out form the plurality of first pieces34.

In the coupled core41, the recesses38are formed in end surfaces on the first side in the lamination direction on the plurality of first pieces34provided on the first side in the lamination direction. In the coupled core41, the recesses40are formed in end surfaces on the second side in the lamination direction on the plurality of second pieces35provided on the second side in the lamination direction. In the rotating body32including the coupled core41, a dimension H4may be set to be the same as the dimension H2(seeFIG. 4) of the permanent magnet45. The dimension H4is the dimension of the coupled core41in the lamination direction (seeFIG. 11).

The coupled core41of the third aspect is described with reference toFIG. 12. The coupled core41includes the plurality of divided cores33and two first ring-shaped cores70. Each divided core33is divided into the first piece34and the second piece35. In the coupled core41, the two first ring-shaped cores70are provided at the same positions as the respective coupled cores41of the first example of the first aspect and the second aspect as described above. The coupled core41is formed by, for example, a manufacturing method including four steps. In this manufacturing method, steps corresponding to the first step to the third step of the second aspect are sequentially conducted first. Lastly, a step corresponding to the second step of the first example of the first aspect is conducted. In the step corresponding to the second step of the first example of the first aspect, second electric steel sheets are laminated on the plurality of first electric steel sheets simultaneously punched out last in the step corresponding to the third step of the second aspect. In other words, the second electric steel sheets are punched out from the electric steel sheet being the material in the following state, and are laminated on the plurality of first pieces34formed in the step corresponding to the third step of the second aspect. The previously-described state is a state where the plurality of divided cores33(the plurality of first pieces34) align with the plurality of first core portions71in the circumferential direction and the radial direction. In the step corresponding to the first step of the second aspect, pluralities of the first electric steel sheets simultaneously punched out form the plurality of second pieces35. In the step corresponding to the second step of the second aspect, the second electric steel sheets form the first ring-shaped core70provided between the first pieces34and the second pieces35. In the step corresponding to the third step of the second aspect, pluralities of the first electric steel sheets simultaneously punched out form the plurality of first pieces34. In the step corresponding to the second step of the first example of the first aspect, the second electric steel sheets form the first ring-shaped core70provided on the first side in the lamination direction.

In the rotating body32including the coupled core41, the following dimension may be set to be the same as the dimension H2(seeFIG. 4) of each permanent magnet45, and the positions of the plurality of divided cores33in the lamination direction in the following state may be set to agree with the positions of the plurality of permanent magnets45in the lamination direction. The previously-described dimension is the dimension (which agrees with the “dimension H4” inFIG. 11) of the divided core33in the lamination direction in a state of sandwiching the first ring-shaped core70. The previously-described state is a state same as that of the coupled core41(seeFIG. 11) of the second aspect where the first ring-shaped core70is sandwiched. According to the rotating body32thus configured, the linkage of the coupled core41and the covering portion50is improved and the stiffness of the rotating body32is increased as in the case of the rotating body32(seeFIGS. 7 and 8) including the coupled core41of the first example of the first aspect. Furthermore, the occurrence of leakage magnetic flux via the first coupling portion72provided on the first side in the lamination direction is prevented. However, the dimension H2of each permanent magnet45may be set to be the same as a dimension H5. The dimension H5is the dimension of the coupled core41in the lamination direction (seeFIG. 12).

UnlikeFIG. 12, the first ring-shaped core70may be provided on the end surfaces of the plurality of divided cores33on the second side in the lamination direction as in the second example of the first aspect. However, in this modification, an illustration related to the following coupled core is omitted. The previously-described coupled core is a coupled core where two first ring-shaped cores70are provided at positions same as those of the coupled cores41in the second example of the first aspect and the second aspect. In a manufacturing method of this coupled core, the following four steps are conducted. In other words, a step corresponding to the first step of the second example of the first aspect is conducted first. Steps corresponding to the first step to third step of the second aspect are then sequentially conducted. In the step corresponding to the first step of the second aspect, the plurality of first electric steel sheets is simultaneously punched out in a state of being arranged at positions that agree with the arrangement of the plurality of divided cores33in the rotating body32, and is laminated on the second electric steel sheet punched out last in the step corresponding to the first step of the second example of the first aspect. In other words, the plurality of first electric steel sheets simultaneously punched out is laminated on the plurality of first core portions71of the first ring-shaped core70formed in the step corresponding to the first step of the second example of the first aspect, respectively. In the step corresponding to the first step of the second example of the first aspect, the second electric steel sheets form the first ring-shaped core70provided on the second side in the lamination direction. In the step corresponding to the first step of the second aspect, pluralities of the first electric steel sheets simultaneously punched out form the plurality of second pieces35. In the step corresponding to the second step of the second aspect, the second electric steel sheets form the first ring-shaped core70provided between the first pieces34and the second pieces35. In the step corresponding to the third step of the second aspect, pluralities of the first electric steel sheets simultaneously punched out forms the plurality of first pieces34. In a rotating body including this coupled core, the arrangement of the plurality of permanent magnets45in the coupled core may be set to be similar to that in the case of the coupled core41(seeFIG. 12) of the above-described third aspect. According to such the rotating body, the linkage of the coupled core and a covering portion is improved and the stiffness of the rotating body is increased as in the case of the rotating body32(seeFIGS. 9 and 10) including the coupled core41of the second example of the first aspect. Furthermore, the occurrence of leakage magnetic flux via the first coupling portion72provided on the second side in the lamination direction can be prevented. However, the dimension H2of each permanent magnet45may be set to be the same as the dimension of the coupled core in the lamination direction.

The coupled core41of the fourth aspect is described with reference toFIGS. 13 and 14. The coupled core41includes the plurality of divided cores33and two second ring-shaped cores75. In the coupled core41, the second ring-shaped cores75are provided on the end surfaces of the plurality of divided cores33on the first side in the lamination direction, and on the end surfaces of the plurality of divided cores33on the second side in the lamination direction. In other words, the plurality of divided cores33is sandwiched between the two second ring-shaped cores75from both sides in the lamination direction. The second ring-shaped core75is formed of a ring-shaped third electric steel sheet. The second ring-shaped core75may be formed by laminating a plurality of third electric steel sheets. In this modification, the second ring-shaped core75is formed by laminating two third electric steel sheets. The number of the third electric steel sheets forming the second ring-shaped core75is determined as appropriate, considering various conditions. In the coupled core41, the second ring-shaped core75is in the following state. The previously-described state is a state where the third electric steel sheets, together with the plurality of first electric steel sheets, are laminated in the lamination direction in the plurality of divided cores33.

The second ring-shaped core75includes a plurality of second core portions76and a second coupling portion77(seeFIG. 13). The number of the second core portions76in the second ring-shaped core75is equal to the number of the divided cores33. In other words, when the number of the divided cores33is 14, the second ring-shaped core75includes 14 second core portions76. The plurality of second core portions76is arranged at positions same as those of the plurality of divided cores33in the circumferential direction and the radial direction. Each second core portion76has a shape corresponding to the shape of each divided core33when viewed in the lamination direction. Therefore, in the coupled core41, the plurality of second core portions76is superposed in the lamination direction in alignment with the plurality of divided cores33. The second coupling portion77is provided to an outer peripheral part of the second ring-shaped core75. The previously-described outer peripheral part corresponds to a part in the circumferential direction between the following two projection portions36. The previously-described two projection portions36are two projection portions36, which face each other in the circumferential direction, of two divided cores33adjacent to each other in the circumferential direction. In other words, the second coupling portion77is formed of a plurality of parts provided at equiangular intervals in the circumferential direction to the outer peripheral part of the second ring-shaped core75. The second coupling portion77is integral at the outer peripheral part of the second ring-shaped core75with the plurality of second core portions76, and couples the plurality of second core portions76in the circumferential direction.

The coupled core41is formed by, for example, the following manufacturing method including a first step to a third step. In the first step, a predetermined number of the third electric steel sheets are punched out from the electric steel sheet being the material. In the first step, the third electric steel sheets form the second ring-shaped core75provided on the second side in the lamination direction. The second step is conducted similarly to the second step of the second example of the first aspect. However, in the second step, the plurality of first electric steel sheets is simultaneously punched out in a state of being arranged at positions that agree with the arrangement of the plurality of divided cores33in the rotating body32, and is laminated on the third electric steel sheet punched out last in the first step. In other words, the plurality of first electric steel sheets simultaneously punched out is laminated on the plurality of second core portions76of the second ring-shaped core75formed in the first step, respectively. In the second step, pluralities of the first electric steel sheets simultaneously punched out form the plurality of divided cores33. In the third step, a predetermined number of the third electric steel sheets are punched out again from the electric steel sheet being the material. In the third step, the third electric steel sheets are laminated on the plurality of first electric steel sheets simultaneously punched out last in the second step. In other words, the third electric steel sheets are punched out from the electric steel sheet being the material in the following state, and are laminated on the plurality of divided cores33formed in the second step. The previously-described state is a state where the plurality of divided cores33align with the plurality of second core portions76in the circumferential direction and the radial direction. In the third step, the third electric steel sheets form the second ring-shaped core75provided on the first side in the lamination direction.

In the coupled core41, the fixing of the first electric steel sheet and the third electric steel sheet laminated in the lamination direction employs caulking. When the second ring-shaped core75is formed of the plurality of third electric steel sheets, the following third electric steel sheet is laminated on the third electric steel sheet punched out previously. The previously-described third electric steel sheet is the third electric steel sheet punched out by the second and later punching in punching for the third electric steel sheet repeated the number of times equal to the number of the third electric steel sheets. The fixing of the plurality of third electric steel sheets also employs caulking. Caulking used to form the coupled core41is performed as in the case of the plurality of first electric steel sheets illustrated inFIG. 5. Hence, a description related to the previously-described caulking is omitted. In the coupled core41, the recesses38are formed in an end surface on the first side in the lamination direction on the second ring-shaped core75provided on the first side in the lamination direction. In the coupled core41, the recesses40are formed in an end surface on the second side in the lamination direction on the second ring-shaped core75provided on the second side in the lamination direction.

In the rotating body32including the coupled core41, the dimension H1(seeFIG. 13) of each divided core33may be set to be the same as the dimension H2(seeFIG. 4) of the permanent magnet45, and the positions of the plurality of divided cores33in the lamination direction may be set to agree with the positions of the plurality of permanent magnets45in the lamination direction (see “arranged state” inFIG. 13). In this case, third spaces S3equal in number to the number of the permanent magnets45are formed in the following plurality of parts on the first side in the lamination direction (seeFIGS. 13 and 14). The previously-described plurality of parts is a plurality of parts each disposed between two second core portions76adjacent to each other in the circumferential direction in the plurality of second core portions76and on the first side in the lamination direction with respect to the end surfaces of the permanent magnets45on the first side in the lamination direction. Fourth spaces S4equal in number to the number of the permanent magnets45are formed in the following plurality of parts on the second side in the lamination direction (seeFIG. 14). The previously-described plurality of parts is a plurality of parts each disposed between two second core portions76adjacent to each other in the circumferential direction in the plurality of second core portions76and on the second side in the lamination direction with respect to the end surfaces of the permanent magnets45on the second side in the lamination direction. The third spaces S3and the fourth spaces S4have the same shape. InFIG. 14, areas of broken lines illustrated on the first side in the lamination direction correspond to the third spaces S3, and areas of broken lines illustrated on the second side in the lamination direction correspond to the fourth spaces S4.

The resin material forming the first part51fills the plurality of third spaces S3. The resin material forming the second part52fills the plurality of fourth spaces S4. Consequently, third protruding portions P3equal in number to the number of the plurality of permanent magnets45are formed on the first part51, and fourth protruding portions P4equal in number to the number of the plurality of permanent magnets45are formed on the second part52. Each third protruding portion P3protrudes toward the second side in the lamination direction, and is fitted in the third space S3(seeFIG. 14). Each fourth protruding portion P4protrudes toward the first side in the lamination direction, and is fitted in the fourth space S4(seeFIG. 14). The third protruding portion P3and the fourth protruding portion P4have the same shape. In the rotating body32, the linkage of the coupled core41and the covering portion50is improved. The stiffness of the rotating body32is increased. No permanent magnet45is provided in the third space S3and the fourth space S4. The occurrence of leakage magnetic flux via the second coupling portion77can be prevented. However, the dimension H2of each permanent magnet45may be set to be the same as a dimension H6. The dimension H6is the dimension of the coupled core41in the lamination direction (seeFIG. 13). In this case, the third space S3and the fourth space S4are not formed. The third protruding portion P3is not formed on the first part51. The fourth protruding portion P4is not formed on the second part52.

At the time of resin molding the covering portion50, the resin material passes through gaps G. Each gap G is a gap formed between the corresponding permanent magnet45and each of the second coupling portions77of the second ring-shaped cores75on the first side and the second side in the lamination direction (seeFIG. 14). Consequently, each third part53is integral at an end portion on the first side in the lamination direction with the first part51, and is integral at an end portion on the second side in the lamination direction with the second part52(seeFIG. 14). The dimension of the second coupling portion77in the radial direction may be made smaller than the dimension of the projection portion36of each divided core33in the radial direction. In addition, a part of the second coupling portion77on the outer peripheral side or the inner peripheral side in the radial direction may be provided with a cutout. According to each of the previously-described configurations, the resin material is allowed to smoothly pass through the gap G. In the coupled core41of the above-described fourth aspect, one of the two second ring-shaped cores75may be omitted. In other words, in the coupled core, the second ring-shaped core75may be provided on the end surfaces of the plurality of divided cores33on one of the first side and the second side in the lamination direction, and may not be provided on the end surfaces of the plurality of divided cores33on the other of the first side and the second side in the lamination direction.

The coupled core41of the fifth aspect is described with reference toFIG. 15. The coupled core41includes the plurality of divided cores33and one second ring-shaped core75. In the coupled core41, the second ring-shaped core75is provided at the following position in the lamination direction in the plurality of divided cores33. The previously-described position is a position between the end surface of each of the plurality of divided cores33on the first side in the lamination direction and the end surface of each of the plurality of divided cores33on the second side in the lamination direction. Furthermore, the previously-described position is a position identical in the lamination direction among the plurality of divided cores33. Each divided core33is divided into the first piece34and the second piece35. The first piece34and the second piece35of each of the plurality of divided cores33sandwich the second ring-shaped core75from both sides in the lamination direction. Consequently, the second ring-shaped core75is in the following third state and fourth state. The third state is a state where the third electric steel sheets, together with the plurality of first electric steel sheets, are laminated in the lamination direction in the plurality of divided cores33. The fourth state is a state where the third electric steel sheets are sandwiched between predetermined two of the plurality of first electric steel sheets in the plurality of divided cores33. The previously-described two first electric steel sheets are the first electric steel sheet forming the end surface of the first piece34on the second side in the lamination direction, and the first electric steel sheet forming the end surface of the second piece35on the first side in the lamination direction. In the coupled core41, the plurality of second core portions76is superposed in the lamination direction in alignment with the plurality of divided cores33as in the coupled core41of the fourth aspect.

The coupled core41is formed by, for example, the following manufacturing method including a first step to a third step. The first step is conducted similarly to the first step of the second aspect. In the first step, pluralities of the first electric steel sheets simultaneously punched out form the plurality of second pieces35. In the second step, a predetermined number of the third electric steel sheets are punched out from the electric steel sheet being the material. The third electric steel sheets are laminated on the plurality of first electric steel sheets simultaneously punched out last in the first step. In other words, the third electric steel sheets are punched out from the electric steel sheet being the material in the following state, and are laminated on the plurality of second pieces35formed in the first step. The previously-described state is a state where the plurality of divided cores33(the plurality of second pieces35) align with the plurality of second core portions76in the circumferential direction and the radial direction. In the second step, the third electric steel sheets form the second ring-shaped core75provided between the first pieces34and the second pieces35. The third step is conducted similarly to the third step of the second aspect. However, in the third step, the plurality of first electric steel sheets is simultaneously punched out in a state of being arranged at positions same as those in the case of the first step, and is laminated on the third electric steel sheet punched out last in the second step. In other words, the plurality of first electric steel sheets simultaneously punched out is laminated on the plurality of second core portions76of the second ring-shaped core75formed in the second step, respectively. In the third step, pluralities of the first electric steel sheets simultaneously punched out form the plurality of first pieces34.

In the rotating body32including the coupled core41, a dimension H7may be set to be the same as the dimension H2(seeFIG. 4) of each permanent magnet45. The dimension H7is the dimension of the coupled core41in the lamination direction (seeFIG. 15). At the time of resin molding the covering portion50, the resin material forming the third parts53passes through the following gaps. Each previously-described gap is a gap formed between the corresponding permanent magnet45and the second coupling portion77of the second ring-shaped core75. In this modification, illustrations of the previously-described gaps are omitted. Consequently, each third part53has a shape continuous in the lamination direction. In order to allow the resin material to smoothly pass through the previously-described gaps, the dimension of the second coupling portion77in the radial direction may be smaller than the dimension of the projection portion36of the divided core33in the radial direction. In addition, a part of the second coupling portion77on the outer peripheral side or the inner peripheral side in the radial direction may be provided with a cutout.

The coupled core41of the sixth aspect is described with reference toFIG. 16. The coupled core41includes the plurality of divided cores33and three second ring-shaped cores75. Each divided core33is divided into the first piece34and the second piece35. In the coupled core41, the three second ring-shaped cores75are provided at positions same as those of the coupled cores41of the fourth aspect and the fifth aspect as described above. The coupled core41is formed by, for example, a manufacturing method including five steps. In this manufacturing method, a step corresponding to the first step of the fourth aspect is conducted first. Next, the steps corresponding to the first step to the third step of the fifth aspect are sequentially conducted. In the step corresponding to the first step of the fifth aspect, the plurality of first electric steel sheets is simultaneously punched out in a state of being arranged at positions that agree with the arrangement of the plurality of divided cores33in the rotating body32, and is laminated on the third electric steel sheet punched out last in the step corresponding to the first step of the fourth aspect. In other words, the plurality of first electric steel sheets simultaneously punched out is laminated on the plurality of second core portions76of the second ring-shaped core75formed in the step corresponding to the first step of the fourth aspect, respectively. Lastly, the step corresponding to the third step of the fourth aspect is conducted. In the step corresponding to the third step of the fourth aspect, the third electric steel sheets are laminated on the plurality of first electric steel sheets simultaneously punched out last in the step corresponding to the third step of the fifth aspect. In other words, the third electric steel sheets are punched out from the electric steel sheet being the material in the following state, and are laminated on the plurality of first pieces34formed in the step corresponding to the third step of the fifth aspect. The previously-described state is a state where the plurality of divided cores33(the plurality of first pieces34) align with the plurality of second core portions76in the circumferential direction and the radial direction.

In the step corresponding to the first step of the fourth aspect, the third electric steel sheets form the second ring-shaped core75provided on the second side in the lamination direction. In the step corresponding to the first step of the fifth aspect, pluralities of the first electric steel sheets simultaneously punched out form the plurality of second pieces35. In the step corresponding to the second step of the fifth aspect, the third electric steel sheets form the second ring-shaped core75provided between the first pieces34and the second pieces35. In the step corresponding to the third step of the fifth aspect, pluralities of the first electric steel sheets simultaneously punched out form the plurality of first pieces34. In the step corresponding to the third step of the fourth aspect, the third electric steel sheets form the second ring-shaped core75provided on the first side in the lamination direction.

In the rotating body32including the coupled core41, the following dimension may be set to be the same as the dimension H2(seeFIG. 4) of each permanent magnet45, and the positions of the plurality of divided cores33in the lamination direction in the following state may be set to agree with the positions of the plurality of permanent magnets45in the lamination direction. The previously-described dimension is the dimension (which agrees with the “dimension H7” inFIG. 15) of each divided core33in the lamination direction in a state of sandwiching the second ring-shaped core75. The previously-described state is a same state same as that of the coupled core41(see FIG.15) of the fifth aspect sandwiching the second ring-shaped core75. According to such a rotating body32, the linkage of the coupled core41and the covering portion50is improved and the stiffness of the rotating body32is increased as in the case of the rotating body32(seeFIGS. 13 and 14) including the coupled core41of the fourth aspect. Furthermore, the occurrence of leakage magnetic flux via the second coupling portions77provided on the first side and the second side in the lamination direction can be prevented. However, the dimension H2of each permanent magnet45may be set to be the same as a dimension H8. The dimension H8is the dimension of the coupled core41in the lamination direction (seeFIG. 16). In the coupled core41of the above-described sixth aspect, one of the two second ring-shaped cores75provide on the first side and the second side in the lamination direction may be omitted. In other words, in the coupled core, the second ring-shaped cores75may be provide on the end surfaces of the plurality of divided cores33on the first side or second side in the lamination direction, and between the first pieces34and the second pieces35.

(4) In the covering portion50, the first part51covers the end surfaces of the plurality of permanent magnets45on the first side in the lamination direction, and the end surfaces of the plurality of divided cores33on the first side in the lamination direction, and the second part52covers the end surfaces of the plurality of permanent magnets45on the second side in the lamination direction, and the end surfaces of the plurality of divided cores33on the second side in the lamination direction (seeFIGS. 4 and 6). The area covered by the first part of the covering portion on the first side in the lamination direction may be the end surfaces of the plurality of permanent magnets45on the first side in the lamination direction, and at least a part of the end surfaces of the plurality of divided cores33on the first side in the lamination direction may be exposed. The area covered by the second part of the covering portion on the second side in the lamination direction may be the end surfaces of the plurality of permanent magnets45on the second side in the lamination direction, and at least a part of the end surfaces of the plurality of divided cores33on the second side in the lamination direction may be exposed. The covering portion including such first part and second part may be employed, for example, in a case where the plurality of divided cores33is coupled by the first ring-shaped core70or the second ring-shaped core75(seeFIGS. 7 to 16).

DESCRIPTION OF REFERENCE SIGNS