Rotor, motor provided with same, and method for manufacturing rotor

Abstract

The rotor includes: a cylindrical rotor core having a plurality of core plates stacked in a thickness direction and a magnet insertion hole extending in an axial direction; and a magnet inserted into the magnet insertion hole. The plurality of core plates include: a first core plate having a first through hole constituting a part of the magnet insertion hole, a second through hole located on one side of the first through hole in the short side direction with respect to the first through hole, and a holding portion located between the first through hole and the second through hole and holding the magnet inserted into the magnet insertion hole; and a second core plate stacked adjacent to the first core plate and positioned at an end portion of the rotor core in the axial direction. The second core plate has a covering portion that covers at least a portion of the second through-hole and the holding portion in the axial direction of the core plate. The covering part is provided with a riveting part which is recessed towards the axial direction.

Description

Technical Field

[0001] The present invention relates to a rotor, a motor including the rotor, and a method for manufacturing the rotor. Background Art

[0002] In a rotor having a magnet inserted in a magnet insertion hole, a structure is known in which a portion of the inner surface of the magnet insertion hole pushes the magnet toward the inside of the magnet insertion hole, thereby holding the magnet in the magnet insertion hole. For example, Japanese Laid-Open Gazette No. 2013-126330 discloses an iron core of a rotating electric machine, wherein a plurality of core plates having insertion holes are stacked to form a permanent magnet, a permanent magnet is inserted into the insertion hole, and a bridge portion between the outer peripheral portion of the core plate and the inner edge of the insertion hole is deformed toward the permanent magnet side so that the bridge portion pushes the permanent magnet.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-126330 Summary of the invention

[0006] Problems to be solved by the invention

[0007] As described above, in a structure in which the magnet is held in the magnet insertion hole by a holding portion that is a part of the inner surface of the magnet insertion hole pushing the magnet, when the magnet inserted into the magnet insertion hole is magnetized, a force pushing the holding portion is sometimes generated on the magnet due to magnetic flux. In a case where the holding portion is movable in the magnet insertion hole, as described above, when the magnet is magnetized, the magnet pushes the holding portion, whereby the holding portion may be plastically deformed. In this way, the force of the holding portion holding the magnet in the magnet insertion hole may be reduced.

[0008] Therefore, in the rotor in which the magnets are held by the holding portion in the magnet insertion hole, a structure capable of suppressing a decrease in the holding force of the magnets is required.

[0009] An object of the present invention is to realize a structure capable of suppressing a decrease in the holding force of a magnet in a rotor in which a magnet inserted into a magnet insertion hole is held by a holding portion.

[0010] Solutions to Solve Problems

[0011] A rotor according to one embodiment of the present invention comprises: a columnar rotor core having a plurality of core plates stacked in an axial direction and a magnet insertion hole extending in the axial direction; and a magnet inserted into the magnet insertion hole. The plurality of core plates comprises: a first core plate having: a first through hole constituting a portion of the magnet insertion hole, a second through hole located on one side of the first through hole in the short side direction relative to the first through hole, and a retaining portion located between the first through hole and the second through hole and retaining the magnet inserted into the magnet insertion hole; and a second core plate stacked adjacent to the first core plate and located at an end of the rotor core in the axial direction. The second core plate comprises a covering portion that covers at least a portion of the second through hole and the retaining portion in the axial direction. The covering portion comprises a rivet portion recessed toward the axial direction.

[0012] A motor according to one embodiment of the present invention includes: a rotor having the above-described structure; and a stator including a stator coil and a stator core.

[0013] A rotor manufacturing method according to one embodiment of the present invention is a method for manufacturing a rotor including: a columnar rotor core having a plurality of core plates stacked in a thickness direction and a magnet insertion hole extending in an axial direction; and a magnet inserted into the magnet insertion hole. The manufacturing method of the rotor comprises: a core plate forming process of forming a first core plate and a second core plate, the first core plate having: a first through hole constituting a part of the magnet insertion hole; a second through hole located on one side of the short side direction of the first through hole relative to the first through hole; and a retaining portion located between the first through hole and the second through hole for retaining the magnet inserted into the magnet insertion hole, the second core plate having a covering portion covering the second through hole and at least a part of the retaining portion in the axial direction; a core plate stacking process of obtaining a columnar rotor core having a magnet insertion hole extending in the axial direction by stacking the second core plate adjacent to the first core plate at a position at an end of the rotor core in the axial direction of the rotor; a magnet insertion process of inserting the magnet into the magnet insertion hole of the rotor core; a rivet portion forming process of forming a rivet portion recessed toward the axial direction on the covering portion after the magnet insertion process; and a magnetization process of magnetizing the magnet inserted into the magnet insertion hole after the rivet portion forming process.

[0014] Effects of the Invention

[0015] According to one embodiment of the present invention, in a rotor in which a magnet inserted into a magnet insertion hole is held by a holding portion, a structure capable of suppressing a decrease in the holding force of the magnet is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram showing an example of a motor according to the first embodiment.

[0017] Figure 2 This is a diagram showing an example of a rotor according to the first embodiment.

[0018] Figure 3 This is a diagram showing an example of a rotor according to the first embodiment.

[0019] Figure 4 yes Figure 3 Sectional view along line IV-IV.

[0020] Figure 5 This is a diagram showing an example of a first core plate according to the first embodiment.

[0021] Figure 6 This is a diagram showing an example of a first core plate according to the first embodiment.

[0022] Figure 7 This is a diagram showing an example of a second core plate according to the first embodiment.

[0023] Figure 8 This is a diagram showing an example of a method for manufacturing a rotor according to the first embodiment.

[0024] Fig. 9 This is a diagram showing an example of inserting magnets into the rotor core according to the first embodiment.

[0025] Fig.10 This is a diagram showing an example of inserting magnets into the rotor core according to the first embodiment.

[0026] Fig.11 This is a diagram showing an example of formation of the caulking portion according to the first embodiment.

[0027] Fig.12 This is a diagram showing an example of a second core plate according to the second embodiment.

[0028] Fig.13 This is a diagram showing an example of forming a caulking portion according to the second embodiment. DETAILED DESCRIPTION

[0029] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same or corresponding parts in the drawings are marked with the same reference numerals, and their descriptions will not be repeated. In addition, the dimensions of the components in each figure do not faithfully show the dimensions of the actual components and the dimensional ratios of the components.

[0030] In the following description of the motor 100, the direction parallel to the central axis P of the rotor 101 is referred to as the "axial direction", the direction orthogonal to the central axis P is referred to as the "radial direction", and the direction along the arc centered on the central axis P is referred to as the "circumferential direction". In addition, in the following description, the thickness direction of the core plate 3 and the stacking direction of the core plate 3 are sometimes described, but the thickness direction and the stacking direction are parallel to the axial direction. However, these definitions are not intended to limit the orientation of the rotor 101 during manufacture and use.

[0031] In the following description, “same” includes not only the case of being strictly the same, but also the range that can be regarded as substantially the same. In other words, as long as the degree of the effect of the invention is the same, it is sufficient.

[0032] In addition, in the following description, expressions such as "fixed", "connected" and "mounted" (hereinafter referred to as fixed, etc.) include not only cases where components are directly fixed to each other, but also cases where components are fixed via other components. That is, in the following description, expressions such as fixed include the meaning of direct and indirect fixing of components to each other.

[0033] (Implementation Method 1)

[0034] (motor)

[0035] use Figure 1 An example of the motor 100 according to Embodiment 1 will be described. The motor 100 is an IPM motor.

[0036] like Figure 1 As shown, the motor 100 includes a rotor 101, a stator 102, a housing 103, and a shaft 104. The rotor 101 rotates about a central axis P relative to the stator 102. In the present embodiment, the motor 100 is a so-called inner rotor type motor in which the rotor 101 is rotatably located about the central axis P in the cylindrical stator 102.

[0037] The rotor 101 includes a rotor core 1 and a magnet 2. The rotor 101 is located radially inside the stator 102 and is rotatable about a central axis P relative to the stator 102.

[0038] The stator 102 is housed in the housing 103. In the present embodiment, the stator 102 is cylindrical. The rotor 101 is located radially inside the stator 102. That is, the stator 102 faces the rotor 101 in the radial direction.

[0039] The stator 102 includes a stator core 105 and a stator coil 106. The stator coil 106 is wound around the stator core 105. The detailed structure of the stator 102 will be omitted.

[0040] (Rotor)

[0041] like Figure 2 As shown, the rotor 101 is in a columnar shape extending along the central axis P. The rotor 101 includes a rotor core 1 and a plurality of magnets 2 .

[0042] (Rotor core and magnets)

[0043] like Figure 2 As shown in FIG. 1 , the rotor core 1 has a shaft insertion hole 1 a extending along the central axis P and penetrating therethrough. Figure 1 As shown in FIG. 1 , the shaft 104 is fixed in a state of penetrating the shaft insertion hole 1 a in the axial direction. As a result, the rotor core 1 rotates together with the shaft 104 .

[0044] The rotor core 1 has a plurality of core plates 3 and a plurality of magnet insertion holes 4. The plurality of core plates 3 are stacked in the thickness direction of the core plates 3. Each core plate 3 is a disk-shaped electromagnetic steel plate formed into a predetermined shape.

[0045] The plurality of magnet insertion holes 4 are positioned at predetermined intervals in the circumferential direction. The plurality of magnet insertion holes 4 penetrate the rotor core 1 in the axial direction. The plurality of magnet insertion holes 4 are rectangular and are longer in one direction when viewed from the axial direction. The plurality of magnet insertion holes 4 include: magnet insertion holes 4 whose length direction is along the outer periphery of the rotor core 1 when viewed from the axial direction; and magnet insertion holes 4 extending from the radial outer peripheral side to the radial inner peripheral side of the rotor core 1 when viewed from the axial direction. The magnets 2 are accommodated in the magnet insertion holes 4. In addition, the plurality of magnet insertion holes 4 may also include magnet insertion holes 4 extending in the radial direction of the rotor core 1 when viewed from the axial direction.

[0046] The magnet 2 is in a rectangular parallelepiped shape and extends in the axial direction. The magnet 2 is inserted into the magnet insertion hole 4 along the magnet insertion direction from one side of the axial direction of the rotor 101, and is accommodated in the magnet insertion hole 4. The magnet 2 is fixed relative to the magnet insertion hole 4 by a retaining portion 53 of the first core plate 5 described later.

[0047] Figure 4 yes Figure 3 IV-IV line cross-sectional view. Figure 4 As shown, the plurality of stacked core plates 3 include a first core plate 5 and a second core plate 6. In the present embodiment, the plurality of first core plates 5 are stacked continuously.

[0048] The second core plate 6 is stacked adjacent to the first core plate 5. The second core plate 6 is stacked on one side and the other side of the axial direction with respect to the plurality of first core plates 5. Figure 4 In the example, the second core plates 6 stacked on one side of the plurality of first core plates 5 in the axial direction are located at the end of the rotor core 1 in the axial direction.

[0049] (First core board)

[0050] use Figure 5 and Figure 6An example of the first core plate 5 in the first embodiment is described. Figure 5 As shown, the first core plate 5 has a plurality of first through holes 51, a plurality of second through holes 52 and a plurality of holding portions 53. Figure 5 The first core plate 5 is shown as viewed from the axial direction.

[0051] Specifically, the first core plate 5 of the present embodiment has two second through holes 52 and two retaining portions 53 relative to one first through hole 51. In addition, the structures of the multiple first through holes 51 of the first core plate 5 are the same. In addition, the structures of the second through holes 52 and the retaining portions 53 relative to each first through hole 51 are the same. Therefore, below, a first through hole 51, a second through hole 52 relative to the first through hole 51, and a retaining portion 53 located between the first through hole 51 and the second through hole 52 are described.

[0052] The first through hole 51 passes through the first core plate 5 in the thickness direction. The first through hole 51 constitutes a part of the magnet insertion hole 4. The magnet 2 is located in the first through hole 51. The plurality of first through holes 51 are rectangular and are long in one direction when viewed from the axial direction. The plurality of first through holes 51 include: a first through hole 51 whose length direction is along the outer periphery of the rotor core 1 when viewed from the axial direction; and a first through hole 51 whose length direction extends from the radial outer peripheral side to the radial inner peripheral side of the rotor core 1 when viewed from the axial direction.

[0053] Figure 6 The first through hole 51 shown has a shape that is long in one direction perpendicular to the radial direction when the first core plate 5 is viewed from the axial direction. Figure 6 yes Figure 5 An enlarged view of the dotted line portion of .

[0054] The second through hole 52 penetrates the first core plate 5 in the thickness direction. The second through hole 52 is located on one side of the short side direction of the first through hole 51 relative to the first through hole 51. For example, the short side direction is a direction orthogonal to the length direction of the first through hole 51. Figure 6 In the example shown, the short side direction is radial. Figure 6 In the example, the second through hole 52 is located radially inside the first through hole 51. In addition, the second through hole 52 sandwiches the holding portion 53 between the second through hole 52 and the first through hole 51. When the first core plate 5 is viewed from the axial direction, the second through hole 52 is, for example, rectangular.

[0055] Specifically, if Figure 6 As shown, when the first core plate 5 is viewed from the axial direction, the second through hole 52 is located radially inward relative to an inner surface 51 a constituting one of a pair of inner surfaces 51 a extending in the longitudinal direction of the first through hole 51 .

[0056] The holding portion 53 is a portion of the first core plate 5 that holds the magnet 2 inserted into the magnet insertion hole 4. The holding portion 53 is located between the first through hole 51 and the second through hole 52.

[0057] Specifically, if Figure 6 As shown, the holding portion 53 constitutes a part of the inner surface 51a. Moreover, the holding portion 53 has a protrusion 54 on the magnet side. That is, the holding portion 53 has a protrusion 54, which is located on the inner surface 51a of the first through hole 51 and protrudes toward the inner side of the magnet insertion hole 4 to contact the magnet 2. Specifically, the protrusion 54 protrudes to the opposite side relative to the second through hole 52. Figure 6 In the structure, the protrusion 54 protrudes radially outward. At this time, the opposite direction of the protrusion direction of the protrusion 54 is the radial inner side. Here, the opposite direction of the protrusion direction of the protrusion 54 may also be one side of the short side direction of the first through hole 51. In addition, the protrusion direction of the protrusion 54 is not limited to the radial outer side. In addition, the opposite direction may not be parallel to the radial inner side.

[0058] The contact area with respect to the magnet 2 can be reduced by the protrusion 54. Therefore, the force with which the holding portion 53 holds the magnet 2 can be increased.

[0059] In addition, if Figure 4 As shown, the first through holes 51 of the plurality of first core plates 5 are arranged in the axial direction. The first through holes 51 of the plurality of stacked first core plates 5 constitute a part of the magnet insertion hole 4.

[0060] In addition, if Figure 4 As shown, the plurality of second through holes 52 are arranged in the axial direction. The second through holes 51 of the first core plate 5 on one axial direction are connected to the second through holes 51 of the first core plate 5 on the other axial direction.

[0061] In addition, if Figure 4 As shown, the plurality of retaining portions 53 are arranged in the axial direction. That is, when the first core plate 5 is viewed from the axial direction, the retaining portion 53 of the first core plate 5 on one side of the axial direction overlaps with the retaining portion 53 of the first core plate 5 on the other side of the axial direction. Furthermore, the plurality of protrusions 54 are arranged in the axial direction.

[0062] (Second core board)

[0063] use Figure 7 An example of the second core plate 6 according to the first embodiment will be described. Figure 7 This is a diagram of the rotor core 1 as viewed from the axial direction, and shows the second core plate 6 located at the axial end of the rotor core 1 .

[0064] The second core plate 6 stacked in the other axial direction with respect to the plurality of first core plates 5 has the same structure. Therefore, the description of the second core plate 6 stacked in the other axial direction will be omitted.

[0065] like Figure 7 As shown, the second core plate 6 has a receiving hole 61 and a covering portion 62 .

[0066] The receiving hole 61 is arranged axially with the first through hole 51 of the adjacent first core plate 5. That is, when the rotor core 1 is viewed axially, the receiving hole 61 of the second core plate 6 overlaps with the first through hole 51 of the adjacent first core plate 5 when the second core plate 5 is viewed axially. In this way, the receiving hole 61 constitutes a part of the magnet insertion hole 4 of the rotor core 1.

[0067] The covering portion 62 covers the first core plate 5 in the axial direction, that is, in the stacking direction of the core plates 3. In the present embodiment, the covering portion 62 covers at least a portion of the second through hole 52 in the axial direction. Figure 7 As shown, when the second core plate 6 is viewed from the axial direction, the cover portion 62 is located at a position overlapping with the second through hole 52 of the first core plate 5. Figure 7 An example is shown in which the covering portion 62 covers both the second through hole 52 and the holding portion 53 of the first core plate 5 in the axial direction.

[0068] (Riveting part)

[0069] use Figure 4 and Figure 7 An example of the caulking portion 7 included in the second core plate 6 of the first embodiment will be described.

[0070] like Figure 4 and Figure 7 As shown, the cover portion 62 of the second core plate 6 located at the end of the rotor core 1 has a caulking portion 7 recessed in the axial direction. When the first core plate 5 and the second core plate 6 are viewed from the axial direction, the caulking portion 7 of the first embodiment is located at least at a position overlapping the second through hole 52.

[0071] like Figure 4 As shown, when the second core plate 6 is viewed from the axial direction, the rivet portion 7 is a portion that is recessed on one surface of the second core plate 6 and protrudes on the other surface at a position in the covering portion 62 that overlaps at least the second through hole 52. The rivet portion 7 protrudes into the second through hole 52.

[0072] Moreover, if Figure 4 As shown, the portion of the rivet portion 7 protruding toward the first core plate 5 contacts the inner surface of the second through hole 52. The portion of the rivet portion 7 contacting the inner surface of the second through hole 52 limits the deformation of the retaining portion 53 toward the second through hole 52. For example, the deformation of the retaining portion 53 toward the radial inside is limited.

[0073] The caulking portion 7 suppresses deformation of the retaining portion 53, so that when the magnet 2 is magnetized, the retaining portion 53 does not plastically deform in the direction of the second through hole 52, for example, radially inward. Therefore, the rotor 101 is realized in which a reduction in the holding force of the retaining portion 53 that holds the magnet 2 inserted into the magnet insertion hole 4 can be suppressed.

[0074] (Method for manufacturing rotor)

[0075] use Figures 8 to 11 An example of a method for manufacturing the rotor 101 according to Embodiment 1 is described. The method for manufacturing the rotor 101 includes a core plate forming step S1 , a core plate laminating step S2 , a magnet inserting step S3 , a caulking portion forming step S4 , and a magnetizing step S5 .

[0076] The core plate forming step S1 is a step of forming the first core plate 5 and the second core plate 6. Through the core plate forming step S1, the first core plate 5 is formed, and the first core plate 5 has: a plurality of first through holes 51 constituting a part of the magnet insertion hole 4; a second through hole 52 located on one side of the short side direction of the first through hole 51 relative to the first through hole 51; and a retaining portion 53 located between the first through hole 51 and the second through hole 52.

[0077] Furthermore, the core plate forming step S1 forms the second core plate 6 having the covering portion 62 that covers at least a portion of the second through hole 52 and the holding portion 53 of the first core plate 5 in the axial direction when the core plates 3 are stacked.

[0078] The core plate stacking step S2 is a step of stacking the first core plate 5 and the second core plate 6 in a predetermined order in the thickness direction. Specifically, the second core plate 6 is adjacent to the first core plate 5 and is stacked at the axial end of the rotor core 1. By completing the core plate stacking step S2, a columnar rotor core 1 having a plurality of core plates 3 stacked in the axial direction and having a magnet insertion hole 4 is obtained. In the magnet insertion hole 4 of the rotor core 1, the protrusion 54 protrudes toward the inside of the magnet insertion hole 4.

[0079] The magnet inserting step S3 is a step of inserting the magnet 2 into the magnet insertion hole 4. Fig. 9 and Fig.10 An example of the magnet insertion step S3 is described below. Fig. 9 As shown, in a state where the magnet 2 is not inserted into the magnet insertion hole 4 , the holding portion 53 and the protruding portion 54 protrude toward the inside of the magnet insertion hole 4 .

[0080] like Fig. 9 As shown, when the magnet 2 is inserted into the magnet insertion hole 4 , the front end of the magnet 2 contacts the protrusion 54 , so that the holding portion 53 and the protrusion 54 are pressed toward the second through hole 52 , for example, radially inward.

[0081] The holding portion 53 and the protrusion 54 are pressed by the magnet 2 and the space in the second through hole 52, so that the holding portion 53 deforms toward the second through hole 52. For example, the holding portion 53 deforms radially inward. The direction in which the holding portion 53 deforms is not limited to the radial inward.

[0082] Furthermore, the projection 54 is displaced toward the second through hole 52 by deformation of the holding portion 53. For example, the holding portion 53 and the projection 54 are displaced radially inward. The magnet 2 can be smoothly inserted by deformation of the holding portion 53 and displacement of the projection 54.

[0083] On the other hand, the holding portion 53 has elastic restoring force. Fig.10 As shown, the protrusion 54 in contact with the magnet 2 pushes the magnet 2 toward the inner side, for example, radially outward, of the magnet insertion hole 4 by elastic restoring force. As a result, the magnet 2 inserted into the magnet insertion hole 4 is pushed against the inner surface of the magnet insertion hole 4 on the opposite side of the holding portion 53 across the magnet 2. As a result, the magnet 2 is held in the magnet insertion hole 4.

[0084] The caulking portion forming step S4 is a step of forming the caulking portion 7 on the second core plate 6 located at the axial end surface of the rotor core 1. Fig.11 As shown, after the magnet insertion step S3, one end of a rod-shaped riveting tool 8, for example, contacts a portion of the covering portion 62 of the second core plate 6 that overlaps with the second through hole 52 when the first core plate 5 and the second core plate 6 are viewed from the axial direction. Axial pressure is applied to the other end of the riveting tool 8. The riveting tool 8 is pressed from one axial direction toward the other, thereby, as shown in FIG. Figure 4 As shown, a rivet portion 7 recessed toward the axial direction is formed on the covering portion 62 of the second core plate 6 .

[0085] After the caulking portion forming step S4 , the magnetizing step S5 is performed. The magnetizing step S5 is a step of magnetizing the magnet 2 inserted into the magnet insertion hole 4 .

[0086] Depending on the direction of the magnetic flux when the magnet 2 is magnetized, there is a situation where the magnet 2 pushes the retaining portion 53 and the protruding portion 54 in the direction of the second through hole 52, for example, radially inward. However, as described above, according to the structure of embodiment 1, in the second core plate 6, a rivet portion 7 is formed in the covering portion 62 that axially covers the second through hole 52. Thus, the rivet portion 7 that protrudes into the inside of the second through hole 52 suppresses the retaining portion 53 from deforming in the direction of the second through hole 52, for example, radially inward.

[0087] In this way, the caulking portion 7 suppresses deformation of the holding portion 53 in the direction of the second through hole 52. Therefore, when the magnet 2 is magnetized, the holding portion 53 does not plastically deform in the direction of the second through hole 52, for example, in the radial direction inward. Therefore, the rotor 101 is realized in which a reduction in the holding force of the holding portion 53 that holds the magnet 2 inserted into the magnet insertion hole 4 can be suppressed.

[0088] In addition, when the first core plate 5 is observed from the axial direction, the rivet portion 7 protrudes toward the inside of the second through hole 52 at least at a position overlapping with the second through hole 52. According to this structure, the rivet portion 7 protruding into the second through hole 52 restricts the deformation of the retaining portion 53 in the through hole toward the second through hole 52, for example, deformation toward the radial inside. Thus, the plastic deformation of the retaining portion 53 toward the second through hole 52, for example, plastic deformation toward the radial inside, is suppressed. Therefore, a rotor 101 is realized that can suppress the reduction of the holding force of the magnet 2 inserted into the magnet insertion hole 4.

[0089] In addition, the portion of the caulking portion 7 protruding into the second through hole 52 contacts the inner surface of the second through hole 52. According to this structure, the portion of the caulking portion 7 contacting the inner surface of the second through hole 52 reliably restricts deformation of the retaining portion 53 in the direction of the second through hole 52, for example, deformation in the radial direction inward. Therefore, the rotor 101 is realized in which the reduction in the retaining force of the magnet 2 inserted into the magnet insertion hole 4 can be suppressed.

[0090] Here, the retaining portion 53 of the first core plate 5 has a protrusion 54 on the magnet side. However, when the magnet 2 is magnetized, the rivet portion 7 also suppresses deformation of the protrusion 54 in the direction of the second through hole 52, for example, deformation in the radial direction inward. Therefore, when the magnet 2 is magnetized, the plastic deformation of the protrusion 54 in contact with the magnet 2 is suppressed. Therefore, a rotor 101 capable of suppressing a reduction in the retaining force of the magnet 2 inserted into the magnet insertion hole 4 is realized.

[0091] In addition, in the present embodiment, the first core plate 5 has a plurality of first through holes 51. For each of the first through holes 51, there is a second through hole 52 and a retaining portion 53. Moreover, the second core plate 6 has a plurality of covering portions 62, and the plurality of covering portions 62 respectively have a rivet portion 7. According to this structure, deformation of the plurality of retaining portions 53 in the direction of the second through hole 52, for example, deformation inward in the radial direction, can be suppressed. Thus, a reduction in the retaining force of the plurality of magnets 2 can be suppressed. Therefore, the plurality of magnets 2 inserted into the magnet insertion hole 4 of the rotor 101 can be more reliably retained.

[0092] Furthermore, the motor 100 includes the rotor 101 of Embodiment 1. According to this configuration, the rotor 101 has a holding force for holding the magnet 2 inserted into the magnet insertion hole 4. Therefore, it is possible to provide the motor 100 which is less likely to fail.

[0093] Moreover, in the manufacturing method of embodiment 1, as described above, after the magnet insertion step S3, a rivet portion forming step S4 is performed to form a rivet portion 7 recessed axially in the covering portion 62, and after the rivet portion forming step S4, a magnetization step S5 is performed to magnetize the magnet 2 inserted into the magnet insertion hole 4.

[0094] According to this manufacturing method, after forming the caulking portion 7, the magnet 2 in the magnet insertion hole 4 is magnetized, thereby suppressing deformation of the retaining portion 5 in the direction of the second through hole 52, for example, deformation in the radial direction inward. Therefore, the rotor 101 having a retaining force that retains the magnet 2 inserted in the magnet insertion hole 4 can be manufactured.

[0095] Furthermore, since the magnet 2 is inserted into the magnet insertion hole 4 before the caulking portion 7 is formed, the holding portion 5 is more easily deformed toward the second through hole 52 than before the caulking portion 7 is formed, and the magnet 2 can be smoothly inserted into the magnet insertion hole 4 .

[0096] (Implementation Method 2)

[0097] Next, use Fig.12 and Fig.13 An example of Embodiment 2 is described. In Embodiment 2, the rivet portion 70 is different from that in Embodiment 1. When the first core plate 5 is observed from the axial direction, it is located at a position that at least partially overlaps with the retaining portion 53. The positions of the rivets in Embodiments 1 and 2 are different, but the structures other than that are the same. Hereinafter, the same figure marks are given to the same structures as in Embodiment 1, and the description is omitted.

[0098] Fig.12 , Fig.13 FIG. 2 is a diagram showing an example of the position of the caulking portion 70 in the second embodiment. Fig.12 , Fig.13 As shown, when the first core plate 5 is viewed from the axial direction, the rivet portion 70 is located at a position at least partially overlapping with the retaining portion 53 . Fig.12 An example is shown in which the entire caulking portion 70 overlaps with the holding portion 53 when the first core plate 5 is viewed from the axial direction.

[0099] In the second embodiment, the caulking portion 70 is formed on the covering portion 62 that axially covers the holding portion 53 in the second core plate 6. Thus, the caulking portion 70 can suppress deformation of the holding portion 53 toward the second through hole 52, for example, radially inward.

[0100] Specifically, according to the structure of the second embodiment, the retaining portion 53 is pressed in the axial direction by the caulking portion 70, so that deformation of the retaining portion 53 in the direction of the second through hole 52 is suppressed. Therefore, when the magnet 2 is magnetized, the retaining portion 53 does not plastically deform in the direction of the second through hole 52, for example, in the radial direction inward. Therefore, the rotor 101 is realized in which a reduction in the retaining force of the magnet 2 inserted into the magnet insertion hole 4 can be suppressed.

[0101] As described above, the rotor 101 according to the first and second embodiments has the following features.

[0102] (1) The rotor 101 of the embodiment includes: a columnar rotor core 1 having a plurality of core plates 3 stacked in the thickness direction and a magnet insertion hole 4 extending in the axial direction; and a magnet 2 inserted into the magnet insertion hole 4. The plurality of core plates 3 include: a first core plate 5 having a first through hole 51 constituting a part of the magnet insertion hole 4, a second through hole 52 located on one side of the first through hole 51 in the short side direction, and a holding portion 53 located between the first through hole 51 and the second through hole 52 and holding the magnet 2 inserted into the magnet insertion hole 4; and a second core plate 6 stacked adjacent to the first core plate 5 and located at an end of the rotor core 1 in the axial direction. The second core plate 6 includes a covering portion 62 covering at least a part of the second through hole 52 and the holding portion 53 in the axial direction. The covering portion 62 includes caulking portions 7, 70 recessed toward the axial direction.

[0103] (2) In the rotor 101 described in (1), when the first core plate 5 is viewed from the axial direction, the caulking portion 7 protrudes into the second through hole 52 at least at a position overlapping with the second through hole 52 .

[0104] (3) In the rotor 101 described in (2), the portion of the caulking portion 7 protruding into the second through hole 52 is in contact with the inner surface of the second through hole 52 .

[0105] (4) In the rotor 101 described in (1), when the first core plate 5 is viewed from the axial direction, the caulking portion 70 of the second core plate 6 at least partially overlaps with the holding portion 53 .

[0106] (5) In the rotor 101 according to any one of (1) to (4), the holding portion 53 of the first core plate 5 has a protruding portion 54 on the magnet side.

[0107] (6) In the rotor 101 described in any one of (1) to (5), the first core plate 5 has a plurality of the first through holes 51, and has the second through holes 52 and the retaining portion 53 for each of the first through holes 51. The second core plate 6 has a plurality of the covering portions 62, and the covering portions 62 cover at least a portion of the second through holes 52 and the retaining portion 53 in the axial direction. The plurality of covering portions 62 respectively have the rivet portions 7, 70.

[0108] (7) The motor 100 includes: the rotor 101 according to any one of (1) to (6); and the stator 102 including the stator coil 106 and the stator core 105 .

[0109] (8) The manufacturing method of the rotor 101 of the embodiment is a method for manufacturing the rotor 101, the rotor 101 comprising: a columnar rotor core 1 having a plurality of core plates 3 stacked in the thickness direction and a magnet insertion hole 4 extending in the axial direction; and a magnet 2 inserted into the magnet insertion hole 4. The manufacturing method of the rotor 101 comprises: a core plate forming step S1 of forming a first core plate 5 and forming a second core plate 6, the first core plate 5 having: a first through hole 51 constituting a portion of the magnet insertion hole 4, a second through hole 52 located on one side of the first through hole in the short side direction relative to the first through hole 51, and a retaining portion 53 located between the first through hole 51 and the second through hole 52 and retaining the magnet 2 inserted into the magnet insertion hole 4, the second core plate 6 having a covering portion 62 covering at least a portion of the second through hole 52 and the retaining portion 53 in the axial direction. ; a core plate stacking step S2, in which the second core plate 6 is stacked adjacent to the first core plate 5 at the end of the rotor core 1 in the axial direction of the rotor 101, thereby obtaining a columnar rotor core 1 having a magnet insertion hole 4 extending in the axial direction; a magnet insertion step S3, in which the magnet 2 is inserted into the magnet insertion hole 4 of the rotor core 1; a riveted portion forming step S4, in which after the magnet insertion step, a riveted portion 7, 70 recessed toward the axial direction is formed on the covering portion 62; and a magnetization step S5, in which after the riveted portion forming step, the magnet 2 inserted into the magnet insertion hole 4 is magnetized.

[0110] (Other embodiments)

[0111] The embodiments of the present invention are described above, but the above embodiments are merely examples for implementing the present invention. Therefore, the present invention is not limited to the above embodiments, and the above embodiments can be appropriately modified and implemented within the scope of the present invention.

[0112] In the first embodiment, the caulking portion 7 protrudes into the second through hole 52 at least at a position overlapping with the second through hole 52 when the first core plate 5 is viewed axially. However, the caulking portion may be located at a position not overlapping with the second through hole when the first core plate is viewed axially.

[0113] In the first embodiment, the portion of the rivet 7 protruding into the second through hole 52 is in contact with the inner surface of the second through hole 52. However, the portion of the rivet 7 protruding into the second through hole only needs to be in contact with the inner surface of the second through hole when the magnet is pressed by magnetization, and does not need to be in contact with the inner surface of the second through hole all the time.

[0114] In the second embodiment, when the first core plate 5 is observed from the axial direction, the riveted portion 70 of the second core plate 6 at least partially overlaps with the retaining portion 53. However, it is also possible that when the first core plate is observed from the axial direction, the riveted portion of the second core plate as a whole overlaps with the retaining portion. When the first core plate is observed from the axial direction, the riveted portion of the second core plate as a whole may not overlap with the retaining portion.

[0115] In the embodiments 1 and 2, the second core plate 6 stacked on one side in the axial direction is located at the end of the rotor core 1 in the axial direction relative to the plurality of first core plates 5. However, the second core plate may be stacked at the other end in the axial direction, the first core plate may be stacked adjacent to the second core plate, and the second core plate located at the other end in the axial direction may have a rivet portion.

[0116] In the embodiments 1 and 2, the retaining portion 53 of the first core plate 5 has a protrusion 54 on the magnet side. However, the retaining portion may not have a protrusion on the magnet side. In addition, the retaining portion only needs to be in contact with the magnet inserted into the magnet insertion hole and be pushed by the magnet when the magnet is inserted into the magnet insertion hole so as to be deformed toward the second through hole. In addition, the retaining portion may also have a protrusion that causes a constant range of the inner surface of the magnet insertion hole to protrude toward the inside of the magnet insertion hole.

[0117] In the first and second embodiments, the plurality of first core plates 5 are stacked continuously. However, the plurality of first core plates may be stacked discontinuously. For example, the second core plate may be stacked between the first core plates, or a core plate other than the second core plate may be stacked.

[0118] In the first and second embodiments, the second through hole 52 is located on one side of the short side direction of the first through hole 51 relative to the first through hole 51. For example, the second through hole 52 is located radially inside the first through hole 51. However, the second through hole may be located on the other side of the short side direction of the first through hole. For example, the second through hole may be located radially outside the first through hole.

[0119] In the embodiments 1 and 2, the second through hole 52 is located on one side of the short side direction of the first through hole relative to the first through hole 51. However, the second through hole only needs to be located on the opposite side of the magnet with respect to the first through hole separated by the retaining portion. That is, when viewed from the axial direction, the second through hole can be located on one or the other side of the circumferential or radial direction of the first core plate relative to the first through hole that constitutes a part of the magnet insertion hole and extends in the longitudinal direction.

[0120] In the first and second embodiments, the rotor core 1 includes a plurality of first core plates 5 stacked continuously at the axial end of the rotor core 1. However, the rotor core may include a plurality of first core plates stacked continuously at a plurality of locations in the axial direction.

[0121] In the first and second embodiments, the first core plate 5 has two second through holes 52 for each first through hole 51. However, the first core plate may have one, three, or more than three second through holes for each first through hole.

[0122] In the above-described first and second embodiments, the first core plate 5 has the second through-holes 52 for all the first through-holes 51. However, the first core plate may have the second through-holes for some of the first through-holes.

[0123] In the above-described first and second embodiments, the first core plate 5 has the holding portions 53 for all the first through holes 51. However, the first core plate may have the holding portions for some of the first through holes.

[0124] In the above-described first and second embodiments, the first core plate 5 has one second through hole 52 for one holding portion 53. However, the number of holding portions may be different from the number of second through holes.

[0125] In the first and second embodiments, the second through hole 52 is rectangular. However, the second through hole may have a shape other than a rectangle. The through hole may have any shape as long as the holding portion is deformed in the arrangement direction of the holding portion and the second through hole.

[0126] In the first and second embodiments, the plurality of second through holes 52 have the same shape. However, some of the second through holes may have different shapes.

[0127] In the first and second embodiments, a plurality of second core plates 6 are stacked on one and the other of the plurality of first core plates 5 in the axial direction of the rotor 101. However, some of the core plates stacked on one and the other of the plurality of first core plates in the axial direction may not be second core plates.

[0128] Possibility of Industrial Application

[0129] The present invention can be used for a rotor of a motor.

[0130] Explanation of symbols

[0131] 100—motor; 101—rotor; 102—stator; 103—housing; 104—shaft; 105—stator core; 106—stator coil; 1—rotor core; 1a—shaft insertion hole; 2—magnet; 3—core plate; 4—magnet insertion hole; 5—first core plate; 51—first through hole; 51a—inner surface; 52—second through hole; 53—holding portion; 54—protrusion; 6—second core plate; 61—storage hole; 61a—inner surface; 62—covering portion; 7, 70—riveting portion; 8—riveting tool; P—center axis.

Claims

1. A rotor comprising: a columnar rotor core having a plurality of core plates stacked in a thickness direction and a magnet insertion hole extending in an axial direction; and a magnet inserted into the magnet insertion hole, The rotor is characterized in that The plurality of core plates have: A first core plate, comprising: a first through hole constituting a part of the magnet insertion hole; a second through hole located on one side of the short side direction of the first through hole relative to the first through hole; and a retaining portion located between the first through hole and the second through hole for retaining the magnet inserted into the magnet insertion hole; and a second core plate, which is stacked adjacent to the first core plate and is located at an end of the rotor core in the axial direction, The second core plate has a covering portion that covers at least a portion of the second through hole and the holding portion in the axial direction. The covering portion has a rivet portion recessed toward the axial direction.

2. The rotor according to claim 1, characterized in that When the first core plate is viewed from the axial direction, the caulking portion protrudes toward the inside of the second through hole at least at a position overlapping with the second through hole.

3. The rotor according to claim 2, characterized in that A portion of the rivet portion that protrudes into the second through hole contacts an inner surface of the second through hole.

4. The rotor according to claim 1, characterized in that When the first core plate is viewed from the axial direction, the rivet portion of the second core plate at least partially overlaps with the retaining portion.

5. The rotor according to any one of claims 1 to 4, characterized in that The holding portion of the first core plate has a protruding portion on the magnet side.

6. The rotor according to any one of claims 1 to 4, characterized in that The first core plate has a plurality of the first through holes, and has the second through hole and the holding portion corresponding to each of the first through holes. The second core plate has a plurality of the covering portions, and the plurality of the covering portions cover at least a portion of the second through hole and the holding portion in the axial direction. The plurality of covering portions include the rivet portion.

7. A motor, characterized in that: have: The rotor according to any one of claims 1 to 4; and The stator comprises a stator coil and a stator core.

8. A method for manufacturing a rotor, comprising: a columnar rotor core having a plurality of core plates stacked in a thickness direction and a magnet insertion hole extending in an axial direction; and a magnet inserted into the magnet insertion hole. The method for manufacturing the rotor is characterized by comprising: A core plate forming process for forming a first core plate and a second core plate, the first core plate having: a first through hole constituting a portion of the magnet insertion hole; a second through hole located on one side of the short side direction of the first through hole relative to the first through hole; and a retaining portion located between the first through hole and the second through hole for retaining the magnet inserted into the magnet insertion hole, the second core plate having a covering portion covering the second through hole and at least a portion of the retaining portion in the axial direction; a core plate laminating step of laminating the second core plate adjacent to the first core plate at a position at an end of the rotor core in the axial direction of the rotor to obtain a columnar rotor core having a magnet insertion hole extending in the axial direction; a magnet inserting step of inserting the magnet into the magnet insertion hole of the rotor core; a rivet forming step, after the magnet inserting step, forming a rivet on the covering portion that is recessed toward the axial direction; as well as A magnetizing step of magnetizing the magnet inserted into the magnet insertion hole after the caulking portion forming step.

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