JP2019068548A - Rotor manufacturing method, rotor, and motor - Google Patents

Abstract

To provide a rotor manufacturing method in which magnets can be fixed without using a separate component such as a plate spring.SOLUTION: The rotor manufacturing method includes: a step S1 of preparing a rotor holder 200; a step S2 of expanding the rotor holder 200 by heating; a step S3 of disposing a plurality of core pieces 401 on the inner side of the heated rotor holder 200; and a step S4 of disposing a plurality of magnets 300 on the inner side of the plurality of core pieces 401. In the step S3 of disposing the plurality of core pieces 401, a gap is formed between the adjacent core pieces 401. In the step S4 of disposing the plurality of magnets 300, a gap is formed between the adjacent magnets 300. The rotor holder 200 is cooled to be contracted so that the plurality of core pieces 401 and the plurality of magnets 300 are fixed by pressure-welding.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rotor manufacturing method, a rotor, and a motor.

  Patent Document 1 discloses a magnet fixing structure for fixing a magnet to a yoke. Specifically, the magnet fixing structure disclosed in Patent Document 1 includes an annular yoke, a plurality of protruding portions, the same number of magnets as the protruding portions, and the same number of elastic bodies as the magnets. The protrusions are integrally formed on the yoke by cold forging. The protrusions are provided at equal intervals in the circumferential direction and project on the inner periphery of the yoke. The magnet is arc-shaped. The magnets are respectively disposed between two circumferentially aligned protrusions. The arc-shaped end of the magnet abuts on one of the two projections. An elastic body is mounted between the other end of the arc and the other protrusion of the magnet. The elastic body fixes the magnet between the two protrusions. Patent Document 1 discloses a leaf spring as an elastic body.

Japanese Examined Patent 7-24450

  However, in the magnet fixing structure disclosed in Patent Document 1, an elastic body such as a leaf spring is required to fix the magnet. Therefore, the number of parts constituting the rotor is increased. In addition, as the number of magnets increases, the number of elastic bodies also increases.

  The present invention has been made in view of the above problems, and an object thereof is to provide a rotor manufacturing method, a rotor and a motor capable of fixing a magnet without using a separate part such as a leaf spring. is there.

  An exemplary method of manufacturing a rotor according to the present invention comprises the steps of: providing a rotor holder having a cylindrical wall extending along a central axis; heating and expanding the rotor holder; and an inner circumferential side of the heated rotor holder. And disposing a plurality of core pieces along the circumferential direction, and disposing a plurality of magnets along the circumferential direction inside the plurality of core pieces. In the step of arranging the plurality of core pieces, a gap is formed in at least a part of the adjacent core pieces, and in the step of arranging the plurality of magnets, the gap is formed in at least part of the adjacent magnets Is formed. The rotor holder cools and contracts, and the plurality of core pieces and the plurality of magnets are press-fixed.

  An exemplary rotor of the present invention comprises a rotor holder, a plurality of magnets, and a plurality of core pieces. The rotor holder has a cylindrical wall extending along a central axis. The plurality of magnets are disposed on the inner circumferential side of the rotor holder. The plurality of core pieces are disposed between the wall portion of the rotor holder and the plurality of magnets. The plurality of magnets and the plurality of core pieces are arranged along the circumferential direction. The plurality of core pieces and the plurality of magnets are press-fixed.

  An exemplary motor of the present invention comprises the above-described exemplary rotor of the present invention and a stator disposed inside the plurality of magnets.

  According to the present invention, the magnet can be fixed without using a separate part such as a leaf spring.

FIG. 1 is a perspective view showing a rotor according to Embodiment 1 of the present invention. FIG. 2 is a plan view showing a rotor according to Embodiment 1 of the present invention. FIG. 3 is a view showing a schematic cross section of a rotor according to Embodiment 1 of the present invention. FIG. 4 is a flowchart showing a method of manufacturing a rotor according to Embodiment 1 of the present invention. FIG. 5 is an enlarged view of a part of the rotor at the time of the pressing process according to the first embodiment of the present invention. FIG. 6 is a perspective view showing a motor according to Embodiment 1 of the present invention. FIG. 7 is a plan view showing another example of the rotor according to Embodiment 1 of the present invention. FIG. 8 is a diagram showing a part of FIG. 7 in an enlarged manner. FIG. 9 is a plan view showing a rotor according to Embodiment 2 of the present invention. FIG. 10 is a plan view showing another example of the rotor according to the embodiment of the present invention. FIG. 11 is a plan view showing still another example of the rotor according to the embodiment of the present invention. FIG. 12 is a plan view showing still another example of the rotor according to the embodiment of the present invention.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. In the drawings, the same or corresponding portions are denoted by the same reference characters and description thereof will not be repeated. In the present specification, for convenience, the direction of the central axis A (see FIG. 1) of the rotor will be described as the vertical direction. However, the vertical direction is determined for the convenience of the description, and the direction of the central axis A is not intended to coincide with the vertical direction. Furthermore, in the present specification, a direction parallel to the central axis A of the rotor is referred to as “axial direction”, and radial and circumferential directions centering on the central axis A of the rotor are referred to as “radial direction” and “circumferential direction”. Describe. Similarly, with regard to the motor, the direction coinciding with the axial direction, radial direction and circumferential direction of the rotor will be referred to as “axial direction”, “radial direction” and “circumferential direction”. However, the definition of these directions is not intended to limit the use direction of the motor and rotor according to the present invention. The “parallel direction” includes a substantially parallel direction.

Embodiment 1
First, an exemplary embodiment 1 of the present invention will be described with reference to FIGS. 1 to 8. FIG. 1 is a perspective view showing a rotor 100 according to the present embodiment.

  The rotor 100 is used for a motor and rotates about a central axis A. The rotor 100 shown in FIG. 1 is used for an outer rotor type motor. The rotor 100 includes a rotor holder 200, a plurality of magnets 300, and a rotor core 400.

  The rotor holder 200 has a cylindrical wall portion 211 extending along the axial direction. Further, the rotor holder 200 has a bottom wall 223. The bottom wall 223 has a through hole 230. A shaft (rotational shaft) is directly or indirectly attached to the through hole 230. In the present embodiment, the rotor holder 200 is formed by drawing a steel plate. By using a steel plate as a material of the rotor holder 200, a magnetic path through which a magnetic flux flows is formed in the rotor holder 200. Specifically, as a material of the rotor holder 200, a cold-rolled steel plate or a steel plate plated with a cold-rolled steel plate can be used.

  The plurality of magnets 300 are disposed on the inner circumferential side of the rotor holder 200 along the circumferential direction. The plurality of magnets 300 generate magnetic flux. The rotor core 400 has a plurality of core pieces 401. The plurality of core pieces 401 are disposed between the wall portion 211 of the rotor holder 200 and the plurality of magnets 300 along the circumferential direction. The plurality of magnets 300 and the plurality of core pieces 401 are press-fixed. In a space 500 inside the plurality of magnets 300, a stator 600 described with reference to FIG. 6 is disposed.

  Each of the plurality of core pieces 401 is formed of a material in which magnetic flux easily flows. Therefore, in each of the plurality of core pieces 401, a magnetic path through which the magnetic flux flows is formed. Preferably, the core piece 401 is formed by a magnetic steel plate such as a silicon steel plate. By using an electromagnetic steel sheet as the material of the core piece 401, the magnetic flux can flow more easily.

  According to the rotor 100 according to the present embodiment, the plurality of magnets 300 and the plurality of core pieces 401 are press-fixed. Therefore, the plurality of magnets 300 and the plurality of core pieces 401 can be fixed without using a separate component such as a leaf spring.

  Further, according to the rotor 100 according to the present embodiment, the plurality of magnets 300 and the plurality of core pieces 401 can be fixed without using a resin such as a sealing resin or an adhesive. Thus, the rotor 100 can be easily applied to a motor installed in a solvent. Specifically, it can be easily applied to, for example, a motor used for a compressor. A motor used for a compressor is immersed in a solvent such as a refrigerant or a lubricating oil that lubricates a shaft. Therefore, when applying the structure which fixes the magnet 300 and the core piece 401 using resin with respect to the motor installed in such a solvent, it is necessary to select resin which has tolerance with respect to a solvent. For this reason, it is not easy to apply the structure which fixes the magnet 300 and the core piece 401 with resin to the motor installed in a solvent. On the other hand, since the rotor 100 according to the present embodiment has a structure for fixing the magnet 300 and the core piece 401 without using resin, it can be easily applied to a motor installed in a solvent.

  Further, according to the rotor 100 according to the present embodiment, the rotor core 400 can widen the width of the magnetic path through which the magnetic flux flows, and can prevent the occurrence of magnetic saturation.

  Subsequently, the rotor 100 according to the present embodiment will be further described with reference to FIGS. 1 and 2. FIG. 2 is a plan view showing the rotor 100 according to the present embodiment.

  As shown in FIGS. 1 and 2, the magnet 300 has an arc shape in plan view. The plurality of magnets 300 has a gap between the adjacent magnets 300. In other words, each end surface 301 on both sides in the circumferential direction of each of the plurality of magnets 300 is apart from the end surface 301 on one side in the circumferential direction of the other magnet 300 positioned adjacent thereto.

  In the present embodiment, each of the plurality of core pieces 401 has a radially inwardly extending protrusion 410. Each protrusion 410 is located in the gap between the adjacent magnets 300, and each magnet 300 is sandwiched by two protrusions 410. In the present embodiment, the end surface 301 of the magnet 300 is in pressure contact with the protrusion 410. Therefore, each magnet 300 is press-fixed by the two protrusions 410.

  According to the rotor 100 according to the present embodiment, since the protrusions 410 are located in the gaps between the adjacent magnets 300, a magnetic short circuit is unlikely to occur between the adjacent magnets 300.

  When the core piece 401 has the projection 410, the core piece 401 is preferably formed of laminated steel plates. A laminated steel plate is formed by laminating punched steel plates. When the core piece 401 is formed of laminated steel plates, the core piece 401 can be easily formed even if the shape of the core piece 401 is complicated. Therefore, the protrusion 410 can be easily formed on the core piece 401.

  Subsequently, the rotor 100 according to the present embodiment will be further described with reference to FIG. As shown in FIG. 2, the main body portion of the core piece 401 excluding the projection 410 has a circular arc shape in plan view, and the outer peripheral surface of the core piece 401 contacts the inner peripheral surface of the wall portion 211 of the rotor holder 200. Further, the outer peripheral surface of the magnet 300 contacts the inner peripheral surface of the main body portion of the core piece 401. Specifically, in the present embodiment, the outer peripheral surface of the core piece 401 is in pressure contact with the inner peripheral surface of the wall portion 211 of the rotor holder 200. The outer peripheral surface of the magnet 300 is in pressure contact with the inner peripheral surface of the main body portion of the core piece 401. In other words, the core piece 401 is sandwiched between the wall portion 211 of the rotor holder 200 and the magnet 300 and fixed by pressure.

  Subsequently, the rotor 100 according to the present embodiment will be further described with reference to FIG. As shown in FIG. 2, the end surface 402 of the core piece 401 in the circumferential direction is preferably disposed at a position facing the central portion 302 of the magnet 300 in the circumferential direction. In the present embodiment, the rotor core 400 is divided into a plurality of core pieces 401. The separated rotor core 400 affects the flow of magnetic flux. However, since the central portion 302 of the magnet 300 has a low magnetic flux density, the end face 402 of the core piece 401 is disposed at a position opposed to the central portion 302 of the magnet 300, whereby the influence on the flow of magnetic flux can be suppressed low.

  Further, as shown in FIG. 2, in the present embodiment, the end surface 402 of the core piece 401 has a shape along the radial direction. Therefore, the flow of the magnetic flux from the central portion 302 of the magnet 300 to the other magnets 300 positioned on both sides in the circumferential direction is not biased, and the influence on the flow of the magnetic flux can be suppressed low. That is, when the end surfaces 402 of adjacent core pieces 401 overlap in the radial direction, the magnetic flux easily flows from the central portion 302 of the magnet 300 to one side in the circumferential direction. On the other hand, when the end face 402 of the core piece 401 has a shape along the radial direction, the end faces 402 of the adjacent core pieces 401 do not overlap in the radial direction, so the influence on the flow of magnetic flux can be suppressed low.

  In addition, although the rotor 100 which concerns on this embodiment has the clearance gap G between the core piece 401 which adjoins, the end surface 402 of the core piece 401 which adjoins may be in contact.

  Subsequently, the rotor 100 according to the present embodiment will be further described with reference to FIG. FIG. 3 is a view showing a schematic cross section of the rotor 100 according to the present embodiment. In detail, FIG. 3 shows the cross section along the III-III line of FIG.

  As shown in FIG. 3, the rotor holder 200 is cup-shaped, and has a large diameter portion 210 and a small diameter portion 220 whose diameter is smaller than that of the large diameter portion 210. The large diameter portion 210 has the wall portion 211 described with reference to FIG. The large diameter portion 210 further includes a connecting portion 212 which connects the wall portion 211 and the small diameter portion 220. In the present embodiment, the connection portion 212 is annular, and protrudes radially inward from one end of the wall portion 211 in the axial direction.

  The small diameter portion 220 has a main body portion 221 and a projecting portion 222. The main body portion 221 has a bottomed cylindrical shape extending in the axial direction, and has the bottom wall 223 described with reference to FIG. The protrusion 222 protrudes from the bottom wall 223 of the main body portion 221 in the axial direction. The through hole 230 described with reference to FIG. 1 penetrates the bottom wall 223 and the protrusion 222. The connecting portion 212 is connected to the end of the small diameter portion 220 opposite to the bottom wall 223.

  In the present embodiment, the inner side surface of the connection portion 212 constitutes a support surface 212 a. The support surface 212 a supports the plurality of core pieces 401 and the plurality of magnets 300. By providing the support surface 212a, the axial position of the plurality of core pieces 401 and the plurality of magnets 300 can be easily positioned.

  Subsequently, a method of manufacturing a rotor according to the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing a method of manufacturing a rotor according to the present embodiment. As shown in FIG. 4, the rotor manufacturing method according to the present embodiment includes a preparation step S1, a heating step S2, a core piece arrangement step S3, a magnet arrangement step S4, and a pressure contact step S5.

  In the preparation step S1, the rotor holder 200 is prepared. In the heating step S2, the prepared rotor holder 200 is heated and expanded. Specifically, the rotor holder 200 is heated to expand the dimension of the rotor holder 200 radially outward. For example, the rotor holder 200 is heated at a temperature of 200 ° C. or more for 1 minute.

  In the core piece arranging step S3, a plurality of core pieces 401 are arranged on the inner peripheral side of the heated rotor holder 200 along the circumferential direction. In the present embodiment, the plurality of core pieces 401 are disposed on the support surface 212a described with reference to FIG. In the core piece arranging step S3, a gap is formed between the adjacent core pieces 401.

  In the magnet disposing step S4, the plurality of magnets 300 are disposed inside the plurality of core pieces 401 along the circumferential direction. For example, the magnet 300 is supported by a jig from the inner peripheral side of the magnet 300. In the magnet disposing step S4, a gap is formed between the adjacent magnets 300.

  In the pressure-contacting process S5, the rotor holder 200 cools and contracts, and the plurality of core pieces 401 and the plurality of magnets 300 are pressure-fixed. In the present embodiment, each core piece 401 has a protrusion 410. Therefore, the end faces 301 on both sides in the circumferential direction of the magnet 300 sandwiched by the two protrusions 410 are pressed against the two protrusions 410.

  Preferably, in the pressure contact step S5, the rotor holder 200 is forcibly cooled by blowing a gas such as air or nitrogen gas onto the rotor holder 200. Alternatively, the rotor holder 200 is placed in a low temperature environment to forcibly cool the rotor holder 200. By forcedly cooling the rotor holder 200, the time required for manufacturing the rotor 100 can be shortened. However, the rotor holder 200 may be naturally cooled, for example, under a room temperature environment.

  Then, with reference to FIG. 5, the press-contacting process S5 which concerns on this embodiment is further demonstrated. FIG. 5 is an enlarged view of a part of the rotor 100 in the pressure-contacting process. Specifically, FIG. 5 shows the movement of the wall portion 211 of the rotor holder 200 and the core piece 401 when the rotor holder 200 cools and contracts.

  As shown in FIG. 5, in the pressure-contacting step S5, the rotor holder 200 contracts radially inward as shown by the arrow D1. Since the gap G is formed between the adjacent core pieces 401, when the rotor holder 200 contracts inward in the radial direction, the core piece 401 narrows the gap G along the circumferential direction as shown by the arrow D2. Moving. As a result, the distance between two projections 410 adjacent to each other in the circumferential direction becomes short, and each magnet 300 is press-fixed by the two projections 410.

  The curvature of the core piece 401 is preferably smaller than the curvature of the wall portion 211 of the rotor holder 200. In this case, the diameter of the rotor holder 200 when the pressing step S5 is completed is larger than the diameter of the rotor holder 200 when prepared in the preparation step S1. As a result, even after completion of the pressure-contacting step S5, pressure inward in the radial direction is applied from the wall portion 211 of the rotor holder 200 to the core piece 401, and the magnet 300 is more strongly pressure-welded . Therefore, the plurality of magnets 300 are more firmly fixed.

  According to the rotor manufacturing method of the present embodiment, the plurality of magnets 300 and the plurality of core pieces 401 can be press-fixed. Therefore, the plurality of magnets 300 and the plurality of core pieces 401 can be fixed without using a separate component such as a leaf spring.

  Furthermore, according to the rotor manufacturing method of the present embodiment, since the protrusions 410 are positioned in the gaps between the adjacent magnets 300, the adjacent magnets 300 are not pressure-welded. Therefore, it is possible to prevent the magnets 300 from being scraped by pressure contact between the magnets 300.

  In the core piece arranging step S3, a gap may be formed in part between the adjacent core pieces 401. In addition, dimensions may be designed such that adjacent core pieces 401 are in contact with each other. However, if the core pieces 401 hit each other before the end face 301 of the magnet 300 hits the protrusion 410, the magnet 300 is not fixed. Therefore, it is preferable to dimension and design such that a gap G is formed between the core pieces 401 adjacent to each other when the end face 301 of the magnet 300 hits the projection 410.

  Subsequently, a motor 101 according to the present embodiment will be described with reference to FIG. FIG. 6 is a perspective view showing a motor 101 according to the present embodiment. As shown in FIG. 6, the motor 101 has the rotor 100 described with reference to FIGS. 1 to 4 and a stator 600. The stator 600 is disposed inside the plurality of magnets 300. The motor 101 shown in FIG. 6 is an outer rotor type motor.

  The stator 600 has a plurality of salient poles 601 and a plurality of coils 602. The plurality of salient poles 601 are radially disposed about the central axis A and extend in the radial direction. A coil 602 is formed on each of the plurality of salient poles 601. The tip of each salient pole 601 faces the inner circumferential surface of the magnet 300 in the radial direction.

  Note that the plurality of magnets 300 may be in the state of being magnetized when the motor 101 is completed, and the plurality of magnets 300 may be in the state of being magnetized when the rotor 100 is completed. There may be no condition.

  The motor 101 according to the present embodiment includes the rotor 100 described with reference to FIGS. 1 to 4. Therefore, according to the motor 101 which concerns on this embodiment, the some magnet 300 and the some core piece 401 can be fixed, without using separate components like a leaf | plate spring. Moreover, the motor 101 which concerns on this embodiment is easily applicable to the motor installed in a solvent. Furthermore, magnetic saturation hardly occurs.

  In the present embodiment, the configuration in which the end surface 402 of the core piece 401 has a shape along the radial direction has been described, but the shape of the end surface 402 of the core piece 401 is The flow of the magnetic flux to the magnet 300 is not particularly limited as long as the influence on the flow of the magnetic flux can be suppressed low.

  FIG. 7 is a plan view showing another example of the rotor 100 according to the present embodiment. FIG. 8 is a diagram showing a part of FIG. 7 in an enlarged manner. As shown in FIGS. 7 and 8, in the end face 402 of the core piece 401, the core piece in the circumferential direction is closer to the portion 421 closer to the wall portion 211 of the rotor holder 200 than the portion 422 farther from the wall portion 211 of the rotor holder 200. It may have a shape close to the central portion 403 of 401. With the end face 402 of the core piece 401 having such a shape (sloped surface), the flow of magnetic flux from the central portion 302 of the magnet 300 to other magnets 300 located on both sides in the circumferential direction is not biased, which affects the flow of magnetic flux. Can be kept low.

Second Embodiment
Subsequently, an exemplary embodiment 2 of the present invention will be described with reference to FIG. However, items different from the first embodiment will be described, and description of the same items as the first embodiment will be omitted. The second embodiment differs from the first embodiment in the shape of the protrusion 410. FIG. 9 is a plan view showing a rotor 100 according to a second embodiment.

  As shown in FIG. 9, the protrusion 410 according to the present embodiment has a main body 411 and a tip end 412. The main body portion 411 extends radially inward (a central axis A side shown in FIG. 1) from the main body portion of the core piece 401. The tip end portion 412 crosses in the circumferential direction with respect to the direction in which the main body portion 411 extends. The tip end portion 412 opposes the radially inner side (central axis A side) of the two magnets 300 arranged with the protrusion 410 interposed therebetween.

  According to the present embodiment, the tip end 412 of the protrusion 410 prevents the magnet 300 from moving inward in the radial direction. Therefore, it is possible to suppress the occurrence of the problem that the magnet 300 falls inward.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiment, and can be implemented in various modes without departing from the scope of the invention.

  For example, in the embodiment of the present invention, the configuration in which the rotor 100 rotates about the central axis A of the rotor 100 has been described, but in the present invention, the rotor rotates about a position off the central axis of the rotor. It may also apply to the configuration. In other words, the present invention is also applicable to an eccentric motor.

  In the embodiment of the present invention, although the configuration in which the rotor holder 200 has the cylindrical wall portion 211 has been described, the rotor holder 200 may have the polygonal wall portion 211 in plan view.

  Further, in the embodiment of the present invention, the configuration for fixing the core piece 401 and the magnet 300 without using an adhesive has been described, but the configuration in which the core piece 401 and the magnet 300 fixed with an adhesive are further pressure welded and fixed Good.

  In the embodiment of the present invention, the arc-shaped magnet 300 is used, but the shape of the magnet 300 is not particularly limited as long as it can generate a magnetic field that rotates the rotor 100. For example, as shown in FIG. 10, the magnet 300 may be rectangular. FIG. 10 is a plan view showing another example of the rotor 100 according to the present embodiment.

  In the embodiment of the present invention, six magnets 300 are used, but the number of magnets 300 is not particularly limited as long as it can generate a magnetic field for rotating the rotor 100. For example, as shown in FIG. 10, twelve magnets 300 may be used.

  Further, in the embodiment of the present invention, the configuration in which the plurality of magnets 300 has a gap between all the adjacent magnets 300 has been described, but the present invention may be applied to a configuration in which the adjacent magnets 300 meet. it can. 11 and 12 are plan views showing further another example of the rotor 100 according to the present embodiment.

  As shown in FIG. 11, all the magnets 300 may be in pressure contact with other magnets 300 located next to them. In other words, the protrusion 410 may be omitted. Specifically, as described with reference to FIGS. 4 and 5, the rotor holder 200 contracts radially inward in the pressure-contacting step S <b> 5. Thus, the core piece 401 also moves radially inward in addition to the circumferential direction. As a result, the magnet 300 also moves in the circumferential direction. Specifically, it moves in a direction to narrow the gap between the adjacent magnets 300. Therefore, adjacent magnets 300 can be pressure-contacted by pressure-contact process S5. In this case, in the magnet disposing step S4 described with reference to FIG. 4, a gap may be formed in part between adjacent magnets 300, or all adjacent magnets 300 may be in contact with each other.

  Alternatively, as shown in FIG. 12, a part of the magnets 300 may be in pressure contact with other magnets 300 located next to it. In other words, the plurality of magnets 300 may have a gap in part between the adjacent magnets 300. In this case, in the magnet disposing step S4 described with reference to FIG. 4, a gap may be formed in a part between the adjacent magnets 300. Although FIG. 12 illustrates a configuration in which the three core pieces 401 have the protrusions 410, the present invention can be applied to a configuration in which at least two core pieces 401 have the protrusions 410. In other words, although FIG. 12 illustrates a configuration in which two magnets 300 are sandwiched by two projections 410, the present invention is also applicable to a configuration in which three or more magnets 300 are sandwiched by two projections 410. It may apply.

  The present invention can be suitably used for a motor.

Reference Signs List 100 rotor 101 motor 200 rotor holder 211 wall 300 magnet 301 end surface 302 center portion 400 rotor core 401 core piece 402 end surface 403 center portion 410 protrusion 411 main portion 412 tip portion 600 stator A central axis

Claims (12)

In a method of manufacturing a rotor used for a motor,
Providing a rotor holder having a cylindrical wall extending along a central axis;
Heating and expanding the rotor holder;
Arranging a plurality of core pieces along the circumferential direction on the inner circumferential side of the heated rotor holder;
Placing a plurality of magnets along the circumferential direction inside the plurality of core pieces;
In the step of arranging the plurality of core pieces, a gap is formed in at least a part of the adjacent core pieces,
In the step of arranging the plurality of magnets, a gap is formed in at least a part of the adjacent magnets,
The rotor manufacturing method, wherein the rotor holder cools and contracts, and the plurality of core pieces and the plurality of magnets are press-fixed. At least two core pieces of the plurality of core pieces each have a projection located in the gap between the adjacent magnets,
The rotor manufacturing method according to claim 1, wherein the circumferential end surface of at least one of the magnets sandwiched by the two protrusions is brought into pressure contact with the two protrusions when the rotor holder cools and contracts. In the rotor used for the motor,
A rotor holder having a cylindrical wall extending along a central axis;
A plurality of magnets disposed on the inner circumferential side of the rotor holder;
A plurality of core pieces disposed between the wall portion of the rotor holder and the plurality of magnets;
The plurality of magnets and the plurality of core pieces are arranged along a circumferential direction,
The rotor, wherein the plurality of core pieces and the plurality of magnets are press-fixed. At least a part of the plurality of magnets has a gap between the adjacent magnets,
At least two core pieces of the plurality of core pieces have a protrusion located in the gap between the adjacent magnets,
The rotor according to claim 3, wherein a circumferential end face of at least one of the magnets sandwiched by two of the protrusions is in pressure contact with the two protrusions.   The rotor according to claim 4, wherein the plurality of magnets have a gap between all adjacent magnets. The protrusion is
A body portion extending from the core piece to the central axis side;
And a tip portion circumferentially intersecting the direction in which the main body portion extends;
The rotor according to claim 4 or 5, wherein the tip end faces the surface on the central axis side of the two magnets arranged across the protrusion.   The rotor according to any one of claims 3 to 6, wherein the core piece is formed of laminated steel plates.   The rotor according to any one of claims 3 to 7, wherein the core piece is formed of a magnetic steel sheet.   The rotor according to any one of claims 3 to 8, wherein the end face of the core piece in the circumferential direction is disposed at a position facing the central portion of the magnet in the circumferential direction.   The rotor according to any one of claims 3 to 9, wherein an end face of the core piece in a circumferential direction has a shape along a radial direction.   The end face of the core piece in the circumferential direction is closer to the central portion of the core piece in the circumferential direction than the portion on the side closer to the wall portion of the rotor holder than the portion on the side distant from the wall portion of the rotor holder. A rotor according to any one of the preceding claims. A rotor according to any one of claims 3 to 11;
And a stator disposed inside the plurality of magnets.

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