Rotor, motor and rotor manufacturing method

Abstract

A rotor capable of rotating about a central axis extending in the axial direction is provided with a yoke that is a cylindrical magnetic body extending in the axial direction. The protruding strip portions of the yoke are connected to one axial end portion of a cylindrical yoke tube portion extending in the axial direction, and a plurality of protruding strip portions are arranged in the circumferential direction at intervals. In each of the protruding strip portions, the protruding portion protrudes inward in the radial direction from one axial end portion of the yoke tube portion. In addition, the extending part extends from the radial inner end part of the protruding part to the other axial direction along the radial inner side surface of the magnet yoke cylinder part. A magnet is disposed between the circumferentially adjacent extension portions. The protruding strip portion and the yoke cylinder portion are integrally configured as a single member.

Description

Technical Field

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

[0002] Conventionally, there is a known motor having a rotor in which a plurality of magnets are arranged in a circumferential direction. For example, the rotor has a magnet holder, and the magnet holder is connected to two annular portions separated in the axial direction by a plurality of struts. The plurality of magnets are respectively held in a space formed by the two annular portions and two struts adjacent in the circumferential direction (see Japanese Patent Publication No. 2014-217161).

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-217161 Summary of the invention

[0006] Technical issues to be solved by the invention

[0007] However, if a holder dedicated to positioning the magnets is disposed on the rotor, the structure of the rotor becomes complicated and the number of parts increases, which may reduce the workability of assembly.

[0008] An object of the present invention is to provide a rotor capable of positioning magnets with a simple structure.

[0009] Means for solving problems

[0010] An exemplary rotor of the present invention is capable of rotating around a central axis extending in the axial direction. The rotor includes a yoke. The yoke is a cylindrical magnetic body extending in the axial direction. A plurality of magnets arranged in the circumferential direction are arranged on the radial inner side of the yoke. The yoke includes a cylindrical yoke tube portion and a protrusion portion. The yoke tube portion extends in the axial direction. The protrusion portion is arranged at one axial end portion of the yoke tube portion, and a plurality of protrusion portions are arranged in the circumferential direction at intervals. Each of the protrusion portions includes a protrusion portion and an extension portion. The protrusion protrudes radially inward from one axial end portion of the yoke tube portion. The extension portion extends from the radial inner end portion of the protrusion portion to the other axial direction along the radial inner side of the yoke tube portion. The magnet is arranged between the circumferentially adjacent extension portions. The protrusion portion and the yoke tube portion are integrally formed as a single component.

[0011] An exemplary motor of the present invention includes the above-described rotor.

[0012] In an exemplary rotor manufacturing method of the present invention, a rotor capable of rotating around an axially extending central axis is manufactured. In the rotor, a plurality of extension portions are arranged at intervals in the circumferential direction. The extension portion extends axially relative to the radial inner side surface of the axially extending yoke cylinder portion. In addition, a magnet is arranged between the circumferentially adjacent extension portions. The rotor manufacturing method includes a step of forming the extension portion by bending a column portion with the root of the column portion as a fulcrum, wherein the column portion protrudes from one axial end of the yoke cylinder portion and a plurality of column portions are arranged circumferentially at intervals.

[0013] Effects of the Invention

[0014] According to the exemplary rotor, motor, and rotor manufacturing method of the present invention, it is possible to provide a rotor capable of positioning a magnet with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view showing a schematic structural example of a motor.

[0016] Figure 2 It is a three-dimensional diagram of the rotor.

[0017] Figure 3 This is an exploded perspective view of the rotor.

[0018] Figure 4 This is a flowchart for explaining an example of a method for manufacturing a rotor.

[0019] Figure 5A This is a schematic diagram showing an example of a process of forming a plate-shaped member from a plate-shaped magnetic body.

[0020] Figure 5B This is a schematic diagram showing an example of a process of forming the yoke cylindrical portion by drawing a plate-like member.

[0021] Figure 5C This is a schematic diagram showing an example of a process of arranging the extension portion on the radial inner side surface of the yoke cylindrical portion by folding the column portion.

[0022] Figure 6 This is a flowchart for explaining another example of the method for manufacturing a rotor.

[0023] Fig. 7A This is a schematic diagram showing an example of a process of forming another plate-shaped member from a plate-shaped magnetic body.

[0024] Figure 7B This is a schematic diagram showing an example of a process of forming the yoke cylindrical portion by bending a plate-like member.

[0025] Figure 7CThis is a schematic diagram showing an example of a process of disposing the extension portion on the radial inner side surface of the yoke cylindrical portion by folding the column portion.

[0026] Explanation of symbols

[0027] 100: Motor; 101: Shaft; 1: Rotor; 11: Rotor cover; 111: Hole; 112: Opening; 12: Rotor tube; 13: Yoke; 13a, 13b: Plate-like member; 131: Yoke tube; 131a: Circular plate; 131b: Rectangular portion; 132: Protrusion; 132a, 132b: Column; 1321: Protrusion; 1322: Extension; 14; Magnet; 2: Stator; 21: Stator core; 22: Insulator; 23: Coil; 3: Housing; 31: Base; 32: Retainer tube; 321: Bearing; 4: Circuit board; CA: Center axis; Da: One axial direction; Db: The other axial direction. DETAILED DESCRIPTION

[0028] Exemplary embodiments will be described below with reference to the accompanying drawings.

[0029] In the present specification, in the motor 100, the direction parallel to the central axis CA is referred to as the "axial direction". The direction from the rotor 1 to be described later toward the base portion 31 in the axial direction is referred to as the "one axial direction Da", and the direction from the base portion 31 toward the rotor 1 is referred to as the "other axial direction Db". In addition, the direction orthogonal to the central axis CA is referred to as the "radial direction", and the rotation direction centered on the central axis CA is referred to as the "circumferential direction". The direction close to the central axis CA in the radial direction is referred to as the "radial inner side", and the direction away from the central axis CA is referred to as the "radial outer side".

[0030] In addition, in this specification, "annular" includes not only a shape that is continuously connected without gaps in the entire area in the circumferential direction centered on the central axis CA, but also a shape that has one or more gaps in a part of the entire area centered on the central axis CA. In addition, it also includes a shape that draws a closed curve on a curved surface intersecting the central axis CA with the central axis CA as the center.

[0031] In addition, in the positional relationship between any one of the orientations, lines and planes and any other one, "parallel" includes not only a state where the two do not intersect at all wherever they extend, but also a state where they are substantially parallel. In addition, "perpendicular" and "orthogonal" include not only a state where the two intersect each other at 90 degrees, but also a state where they are substantially perpendicular and a state where they are substantially orthogonal. That is, "parallel", "perpendicular" and "orthogonal" include a state where the positional relationship between the two is angularly offset to a degree that does not deviate from the main purpose of the present invention.

[0032] In addition, these names are used only for explanation, and are not intended to limit actual positional relationships, directions, names, etc.

[0033] <1. Implementation Method>

[0034] Figure 1 2 is a cross-sectional view showing a schematic structural example of the motor 100. Figure 1 The cross-sectional structure of the motor 100 is shown when it is virtually cut along a plane that is parallel to the axial direction and includes the central axis CA.

[0035] <1-1. Motor 100>

[0036] like Figure 1 As shown, the motor 100 includes a shaft 101, a rotor 1, a stator 2, a housing 3, and a circuit board 4. According to the motor 100, as described later, it is possible to provide a rotor 1 capable of positioning the magnet 14 with a simple and inexpensive structure, and it is possible to improve the productivity of the rotor 1. In addition, it is possible to suppress or prevent the magnet 14 from being arranged obliquely when viewed from the radial direction, or the magnets 14 adjacent to each other in the circumferential direction from contacting each other.

[0037] The shaft 101 extends axially along the central axis CA and can rotate around the central axis CA. That is, in the present embodiment, the shaft 101 is a rotating shaft. However, this example is not limiting, and the shaft 101 may also be a fixed shaft fixed together with the stator 2, or may not rotate around the central axis CA. In the case of a fixed shaft, a bearing is arranged between the shaft 101 and the rotor 1, and the bearing supports the rotor 1 so that it can rotate relative to the shaft 101.

[0038] The rotor 1 is rotatable about a central axis CA extending in the axial direction. The rotor 1 includes a rotor cover 11 , a rotor cylinder 12 , a yoke 13 , and a plurality of magnets 14 .

[0039] The rotor cover 11 is fixed to one axial end of the shaft 101. As described above, the rotor 1 includes the rotor cover 11. The rotor cover 11 is arranged closer to the other axial direction Db than the stator 2 and the yoke 13 (particularly the protrusions 132 described later) and the like, and extends in the radial direction.

[0040] In the present embodiment, the rotor cover 11 has a hole 111 and an opening 112. The hole 111 is arranged on one axial end surface of the rotor cover 11 at the radial center of the rotor cover 11. In addition, in the present embodiment, the hole 111 is a recessed portion recessed toward the other axial direction Db, but it is not limited to this example, and it can also be a through hole extending in the axial direction. One axial end of the shaft 101 is inserted through and fixed to the hole 111. The opening 112 opens toward one axial direction Da and the other axial direction Db of the rotor cover 11, and is arranged at a position radially outside than the hole 111, and a plurality of them are arranged in the circumferential direction.

[0041] The rotor tube portion 12 has a cylindrical shape extending from the radially outer end portion of the rotor cover portion 11 in the axial direction Da. As described above, the rotor 1 includes the rotor tube portion 12. The rotor tube portion 12 surrounds the stator 2, the yoke 13, and the like.

[0042] The yoke 13 is arranged on the radially inner side of the rotor tube 12 and surrounds the stator 2. As described above, the rotor 1 has the yoke 13. The yoke 13 is a cylindrical magnetic body extending in the axial direction. A plurality of magnets 14 are arranged in the circumferential direction on the radially inner side of the yoke 13.

[0043] The plurality of magnets 14 surround the stator 2 (particularly the stator core 21 described later) and face each other in the radial direction. The plurality of magnets 14 are arranged at intervals in the circumferential direction. The magnetic poles (S poles and N poles) on the radial inner sides of the magnets 14 adjacent in the circumferential direction are alternately different.

[0044] Then, the stator 2 generates magnetic flux through the power supply, which causes the rotor 1 to rotate. Figure 1 As shown, the stator 2 includes a stator core 21 , an insulator 22 , and a coil portion 23 .

[0045] A plurality of coil portions 23 arranged in the circumferential direction are arranged on the stator core 21. The stator core 21 is an annular magnetic body surrounding the shaft 101, and in this embodiment is a laminated body formed by overlapping radially extending plate-shaped electromagnetic steel sheets in the axial direction. The stator core 21 is fixed to the radial outer side of the retainer tube portion 32 described later. In addition, the stator core 21 has a slot (omitted from the icon). The slot passes through the stator core 21 in the axial direction, and a plurality of slots are arranged in the circumferential direction.

[0046] The insulator 22 has electrical insulating properties and is disposed on the surface of the stator core 21 (particularly, both end surfaces in the axial direction and the inner side surfaces of the slots, etc.).

[0047] The coil portion 23 is a component in which a conductive wire (reference numerals omitted) is arranged in a coil shape on the stator core 21 via an insulator 22. The conductive wire is, for example, an enameled copper wire or a metal wire covered with an electrical insulating member, and is wound around teeth (not shown) between slots adjacent in the circumferential direction in the stator core 21 to form the coil portion 23. When a drive current is supplied to each of the coil portions 23, the stator 2 is excited and the rotor 1 is driven.

[0048] Next, the housing 3 has a base portion 31 and a retainer tube portion 32. The base portion 31 is arranged at a position closer to the axial one side Da than the stator 2, and extends in the radial direction. The retainer tube portion 32 is a tube extending from the axial other side end surface of the base portion 31 toward the axial other side Db. The retainer tube portion 32 surrounds the shaft 101 and supports the stator core 21.

[0049] A bearing 321 is disposed on the inner circumferential surface (i.e., radially inner surface) of the holder tube portion 32, and the shaft 101 is inserted therethrough. The holder tube portion 32 rotatably supports the shaft 101 via the bearing 321. The bearing 321 may be a rolling bearing such as a ball bearing, a sliding bearing, a fluid dynamic pressure bearing, or the like.

[0050] Next, the circuit board 4 is arranged at a position closer to the stator 2 in the axial direction Da, and is supported by the holder tube portion 32. Figure 1 In the embodiment, the circuit substrate 4 extends radially outward from the radial outer side of the retainer tube portion 32. The circuit substrate 4 is electrically connected to a lead wire (not shown) led out from the coil portion 23. The drive circuit of the stator 2 and the like are mounted on the circuit substrate 4. In addition, external wiring (not shown) is electrically connected to the circuit substrate 4. The external wiring is led out to the outside of the motor 100 to electrically connect the circuit substrate 4 to external equipment, a power source, and the like.

[0051] <1-2. Yoke 13>

[0052] Next, refer to Figures 1 to 3 , a structural example of the yoke 13 is described. Figure 2 It is a perspective view of the rotor 1. Figure 3 is an exploded perspective view of the rotor 1. Figure 2 and Figure 3 In the paper, the directions of one axial direction Da and the other axial direction Db are Figure 1 on the contrary.

[0053] like Figures 1 to 3 As shown, the yoke 13 includes a yoke tube 131 and protrusions 132. The yoke tube 131 is cylindrical and extends in the axial direction. The protrusions 132 are connected to one axial end of the yoke tube 131 and are arranged in a plurality in the circumferential direction at intervals.

[0054] Each of the protrusions 132 includes a protrusion 1321 and an extension 1322. The protrusion 1321 protrudes radially inward from one axial end of the yoke cylinder 131. The extension 1322 extends from the radial inner end of the protrusion 1321 along the radial inner side surface of the yoke cylinder 131 toward the other axial direction Db. Preferably, the extension 1322 is connected to the yoke cylinder 131 and is arranged on the radial inner side surface of the yoke cylinder 131. However, this example does not exclude a structure in which the extension 1322 is not connected to the radial inner side surface of the yoke cylinder 131 in at least one protrusion 132. For example, the extension 1322 may also be radially opposed to the radial inner side surface of the yoke cylinder 131 with a gap therebetween.

[0055] On the radial inner side surface of the yoke cylinder 131, a plurality of extension portions 1322 are arranged at intervals in the circumferential direction. In addition, in the present embodiment, a plurality of extension portions 1322 are arranged at equal intervals in the circumferential direction. The magnet 14 is inserted into the interval and fixed. That is, the magnet 14 is arranged between the circumferentially adjacent extension portions 1322. In addition, the interval We between the circumferentially adjacent extension portions 1322 is the same as the width Wm (for example, the circumferential width) of the magnet 14 in the direction perpendicular to the axial direction and the radial direction, as long as the magnet 14 can be arranged between the circumferentially adjacent extension portions 1322. However, the above example does not exclude a structure in which the interval We between the circumferentially adjacent extension portions 1322 is larger than the width Wm of the above-mentioned magnet 14, and a structure in which at least a plurality of extension portions 1322 are arranged at different intervals in the circumferential direction.

[0056] The protrusions 132 and the yoke tube 131 are integrally formed as a single component. In this way, the yoke tube 131 and the plurality of protrusions 132 protruding from one axial end thereof can be integrally formed into a single plate-like component 13a (see the following description) by, for example, stamping a plate-like magnetic body. Figure 5A and Fig. 7A ). Moreover, the yoke cylinder 131 is formed into a cylindrical shape, and a plurality of protrusions 132 are arranged in the circumferential direction. Then, each of the protrusions 132 is bent from its root and overlapped on the radial inner side surface of the yoke cylinder 131. As a result, a plurality of extensions 1322 extending in the axial direction can be arranged in the circumferential direction and easily arranged on the radial inner side surface of the yoke cylinder 131, and the magnet 14 can be arranged between the circumferentially adjacent extensions 1322. That is, compared with a structure in which the extensions 1322 are formed on the radial inner side surface of the yoke cylinder 131 by cutting or the like, a plurality of extensions 1322 can be easily and cheaply arranged on the radial inner side surface of the yoke cylinder 131. Therefore, a rotor 1 capable of positioning the magnets 14 with a simple and inexpensive structure can be provided, and the productivity of the rotor 1 can be improved. In addition, it is possible to suppress or prevent the magnets 14 from being arranged obliquely when viewed from the radial direction, or the magnets 14 adjacent in the circumferential direction from contacting each other.

[0057] In addition, the rotor cylinder 12 surrounds the yoke cylinder 131 and is in contact with the radial outer side of the yoke cylinder 131. In addition, the other axial end of the yoke cylinder 131 is in contact with the rotor cover 11. Since the protrusion 312 is folded from one axial end of the yoke cylinder 131 to the radial inner side, the yoke 13 can be easily mounted on the rotor cover 11 and the rotor cylinder 12 by inserting the other axial end of the yoke cylinder 131 toward the rotor cylinder 12 and abutting against the rotor cover 11. In addition, by inserting the magnet 14 from the axial one side Da between the circumferentially adjacent extensions 1322, the magnet 14 can be easily arranged on the radial inner side of the rotor cylinder 12 and the yoke 13.

[0058] Preferably, the other axial end of the extension portion 1322 is arranged at a position closer to the other axial direction Db than the one axial end of the yoke cylinder 131 and closer to the one axial direction Da than the other axial end of the yoke cylinder 131. In other words, the other axial end of the extension portion 1322 does not reach the one axial end of the yoke cylinder 131. That is, the axial length L1 of the extension portion 1322 is less than the axial width W1 of the yoke cylinder 131 (refer to Figure 3 In this way, the axial length of the protrusion 132 before the protrusion 1321 is formed by bending can be shortened (i.e., the axial length of the protrusion 1321 described later). Figure 5A and Fig. 7A Therefore, the yoke 13 that can be formed of one magnetic body can be further increased (see the axial length L2 of the columnar portions 132a and 132b described later). FIG. 5A to FIG. 5C and 7A to 7C ) number. Therefore, the production efficiency of the yoke 13 can be improved.

[0059] More preferably, the axial length L1 of the extension portion 1322 is greater than one third (W1 / 3) of the axial width of the yoke cylinder portion 131 and less than the axial width W1 of the yoke cylinder portion 131. More preferably, the axial length L1 of the extension portion 1322 is greater than one half (W1 / 2) of the axial width of the yoke cylinder portion 131 and less than the axial width W1 of the yoke cylinder portion 131. In this way, it is possible to prevent the magnet 14 arranged between the circumferentially adjacent extension portions 1322 from being arranged tilted when viewed from the radial direction. Therefore, the magnet 14 can be arranged with high precision.

[0060] In the case of L1<(W1 / 2), the magnet 14 may be arranged to be inclined when viewed from the radial direction. In the case of L1<(W1 / 3), this possibility is further increased.

[0061] In addition, when L1>W1, the other axial end of the extension portion 1322 protrudes in the other axial direction Db more than the other axial end of the yoke tube portion 131. Therefore, the other axial end of the extension portion 1322 abuts against other components (such as the rotor cover portion 11), etc., which may hinder the assembly of the rotor 1.

[0062] However, the above-mentioned examples do not exclude the structure of L1<(W1 / 2) (and the structure of L1<(W1 / 3)) and the structure of L1>W1.

[0063] In addition, it is preferred that the radial thickness t1 of the extension portion 1322 is the same as the radial thickness t2 of the yoke tube portion 131. In this case, the yoke 13 having the extension portion 1322 disposed on the radial inner side surface can be formed from a single plate-shaped magnetic body without the need for a process of changing the thickness of the extension portion 1322. However, this example does not exclude a structure where t1≈t2 is not satisfied. For example, t1>t2 or t1 <t2。

[0064] In addition, in the present embodiment, in each of the protrusions 132, the circumferential width W2 of the protrusion 1321 is the same as the circumferential width W3 of the extension 1322. However, this example is not limiting, and in at least any one of the protrusions 132, the circumferential width W2 of the protrusion 1321 may be smaller than the circumferential width W3 of the extension 1322. In this case, the root of the protrusion 132 protruding from the yoke cylinder 131 is easy to bend. Alternatively, in at least any one of the protrusions 132, the circumferential width W2 of the protrusion 1321 may be larger than the circumferential width W3 of the extension 1322. In this case, when the protrusion 132 is bent, the root of the protrusion 132 can be prevented from being broken. In addition, in the case of W2>W3, the magnet 14 can be inserted from the radial inside to the radial outside and fixed between the circumferentially adjacent extensions 1322.

[0065] <1-4. Method for manufacturing rotor 1>

[0066] Next, refer to Figures 3 to 5C , an example of a method for manufacturing the rotor 1 is described. Figure 4 This is a flowchart for explaining an example of a method for manufacturing the rotor 1 . FIG. 5A to FIG. 5C It is a schematic diagram showing an example of a manufacturing process of the yoke 13 . Figure 5A This is a schematic diagram showing an example of a process of forming the plate-shaped member 13a from a plate-shaped magnetic body. Figure 5B This is a schematic diagram showing an example of a process of forming the yoke tube portion 131 by drawing the plate-like member 13a. Figure 5C 1 is a schematic diagram showing an example of a process of arranging the extending portion 1322 on the radially inner side surface of the yoke cylindrical portion 131 by folding the column portion 132 a .

[0067] exist Figure 4 In the manufacturing method of the rotor 1 shown in the figure, a plurality of extension portions 1322 extending axially relative to the radial inner side surface of the yoke cylinder portion 131 are arranged at intervals in the circumferential direction. In addition, the yoke cylinder portion 131 can rotate around the central axis CA extending in the axial direction and extend in the axial direction. Moreover, the magnet 14 is arranged between the extension portions 1322 adjacent in the circumferential direction.

[0068] First, form Figure 3The yoke 13 shown (step S1a).

[0069] In detail, Figure 5A As shown, a single plate-like component 13a (step S11a) is formed from a plate-like magnetic body by punching based on stamping processing. In addition, the plate-like component 13a integrally includes a circular plate portion 131a and a plurality of pillar portions 132a. The circular plate portion 131a is a circular plate shape with an opening in the center. A plurality of pillar portions 132a protrude radially inward from the inner edge portion of the circular plate portion 131a. In addition, step S1a includes step S11a. In addition, the "radial inner side" of the pillar portion 132a protrudes is the direction close to the axis corresponding to the central axis CA as a reference. The axis passes through the center of the opening of the circular plate portion 131a and extends parallel to the normal direction of the plate-like component 13a. In addition, a plurality of pillar portions 132a are arranged at equal intervals along the inner edge portion of the circular plate portion 131a.

[0070] Then, if Figure 5B As shown, by deep drawing based on stamping, the disk portion 131a becomes a tube extending in the normal direction of the plate-shaped member 13a (step S12a). Thus, the yoke tube portion 131 surrounding the central axis CA is formed. In addition, step S1a includes step S12a. In addition, Figure 5B In the embodiment, the column portion 132 a protrudes radially inward from one axial end portion of the yoke cylindrical portion 131 .

[0071] According to steps S11a and S12a, the disk portion 131a of a single plate-shaped member 13a formed of a plate-shaped magnetic body can be formed into a cylindrical shape by simple and inexpensive processes such as stamping and drawing. In addition, the seamless yoke tube portion 131 can be formed with high precision. Therefore, the yoke tube portion 131 and the protrusion portion 132 (in the case of the yoke tube portion 131) formed as a single component can be efficiently formed. Figure 5B The cylindrical yoke 13 is a columnar portion 132a.

[0072] Afterwards, if Figure 5C As shown in FIG. 1 , each of the column portions 132a is folded in the other axial direction Db (step S13a). Figure 5C The column 132a is bent using the radial outer end of the column 132a as a fulcrum to form a protruding strip 132. In addition, the column 132a protrudes from one axial end of the yoke cylinder 131, and a plurality of columns 132a are arranged in the circumferential direction at intervals. In addition, step S1a includes step S13a.

[0073] According to step S13a, compared with a structure in which the extension portion 1322 is formed on the radial inner side surface of the yoke tube portion 131 by cutting or the like, it is possible to provide a rotor 1 capable of positioning the magnet 14 with a simple and inexpensive structure, thereby improving the productivity of the rotor 1. In addition, it is possible to suppress or prevent the magnet 14 from being arranged obliquely when viewed from the radial direction, or the magnets 14 adjacent to each other in the circumferential direction from contacting each other.

[0074] Next, a rotor cover 11 and a rotor tube 12 are mounted inside the covered cylindrical member. Figure 3 The yoke 13 shown is mounted (step S2). In the present embodiment, the yoke 13 is mounted by press-fitting. However, the mounting method of the yoke 13 is not limited to this example. For example, bonding using an adhesive, screwing of an internal thread formed on the radial inner side of the rotor cylinder 12 and an external thread formed on the radial outer side of the yoke cylinder 131, and insert molding of the yoke 13 with the rotor cover 11 and the rotor cylinder 12, etc. may also be adopted.

[0075] The magnets 14 are respectively arranged between the circumferentially adjacent extensions 1322 of the yoke 13 (step S3). For example, the magnets 14 are inserted and fixed between the circumferentially adjacent extensions 1322 from one axial direction Da side toward the other axial direction Db. Alternatively, the magnets 14 may be inserted between the circumferentially adjacent extensions 1322 from the radial inside toward the radial outside. In addition, the fixing method of the magnets 14 may be, for example, press-fitting, bonding using an adhesive, brazing using silver solder, etc.

[0076] Through the above, Figure 4 The manufacturing method is completed and can manufacture Figure 2 The rotor 1 is shown.

[0077] In addition, step S3 may be performed between steps S1a and S2. That is, the method for manufacturing the rotor 1 may be performed in the order of steps S1a, S3, and S2. For example, in step S2, the yoke 13 in which the magnets 14 are respectively arranged between the circumferentially adjacent extension portions 1322 may be mounted inside the covered cylindrical member composed of the rotor cover portion 11 and the rotor cylinder portion 12.

[0078] Alternatively, steps S13a and S2 may be performed after step S3. That is, in the method for manufacturing the rotor 1, steps S11a, S12a, S3, S13a, and S2 may be performed in this order. For example, in step S3, Figure 5BThe yoke 13 in the state shown is mounted on the inner side of a covered cylindrical member composed of the rotor cover 11 and the rotor cylinder 12. Then, the extensions 1322 may be arranged at intervals in the circumferential direction by folding each of the column portions 132a on the radial inner side of the yoke cylinder 131. Furthermore, the magnets 14 may be respectively arranged between the extensions 1322 adjacent in the circumferential direction.

[0079] <1-5. Other methods for manufacturing the rotor 1>

[0080] Next, refer to Figure 3 and Figures 6 to 7C , another example of the method for manufacturing the rotor 1 will be described. Figure 6 This is a flowchart for explaining another example of the method for manufacturing the rotor 1 . 7A to 7C It is a schematic diagram showing another example of the manufacturing process of the yoke 13 . Fig. 7A It is a schematic diagram showing an example of a process of forming another plate-shaped member 13b from a plate-shaped magnetic body. Figure 7B 1 is a schematic diagram showing an example of a process of forming the yoke tube portion 131 by bending the plate-like member 13 b . Figure 7C 1 is a schematic diagram showing an example of a process of arranging the extending portion 1322 on the radially inner side surface of the yoke cylindrical portion 131 by folding the column portion 132 b .

[0081] First, in Figure 6 In other manufacturing methods of the rotor 1 shown, Figure 4 In comparison, step S1b of forming the yoke 13 is different.

[0082] In detail, Fig. 7A As shown, a single plate-like component 13b is formed from a plate-like magnetic body by punching based on a stamping process or the like (step S11b). In addition, the plate-like component 13b integrally includes a plate-like rectangular portion 131b and a plurality of column portions 132b. The plurality of column portions 132b protrude from one side of the outer edge portion of the rectangular portion 131b. In addition, step S1b includes step S11b. In addition, the plurality of column portions 132b are arranged at equal intervals in a direction perpendicular to the normal direction of the rectangular portion 131b and the direction in which the column portions 132b extend.

[0083] Then, if Figure 7B As shown, the rectangular portion 131b is bent into a cylindrical shape around an axis (ie, central axis CA) parallel to the direction in which the column portion 132b extends (ie, axial direction) (step S12b). Thus, the yoke cylindrical portion 131 is formed. In addition, step S1b includes step S12b.

[0084] According to steps S11b and S12b, a single plate-shaped member 13b formed of a plate-shaped magnetic body can be bent into a cylindrical shape by a simple and inexpensive process such as stamping. Therefore, a single member composed of the yoke cylindrical portion 131 and the protruding strip portion 132 ( Figure 7B The cylindrical yoke 13 is formed integrally with the column portion 132b.

[0085] Afterwards, if Figure 7C As shown in FIG. 1 , each of the column portions 132b is folded inwardly in the radial direction toward the other axial direction Db (step S13b). Figure 7C The column 132b is bent using the other axial end of the column 132b as a fulcrum to form the protrusion 132. In addition, the column 132b protrudes from one axial end of the yoke cylinder 131, and a plurality of columns 132b are arranged in the circumferential direction at intervals. In addition, step S1b includes step S13b.

[0086] According to step S13b, compared with a structure in which the extension portion 1322 is formed on the radial inner side surface of the yoke tube portion 131 by cutting or the like, it is possible to provide a rotor 1 capable of positioning the magnet 14 with a simple and inexpensive structure, thereby improving the productivity of the rotor 1. In addition, it is possible to suppress or prevent the magnet 14 from being arranged obliquely when viewed from the radial direction, or the magnets 14 adjacent to each other in the circumferential direction from contacting each other.

[0087] in addition, Figure 6 The subsequent steps in (e.g., steps S2 and S3) are Figure 4 Therefore, their description is omitted.

[0088] <2. Others>

[0089] The above describes the embodiments of the present invention. In addition, the scope of the present invention is not limited to the above embodiments. The present invention can be implemented by applying various changes to the above embodiments without departing from the gist of the invention. In addition, the matters described in the above embodiments can be appropriately combined in any manner without causing contradictions.

[0090] <3. Conclusion>

[0091] The embodiments described so far will be summarized below.

[0092] For example, the rotor disclosed herein is configured to be rotatable about a central axis extending in the axial direction.

[0093] The yoke is provided with a yoke which is a cylindrical magnetic body extending in the axial direction and has a plurality of magnets arranged in the circumferential direction arranged on the radial inner side surface.

[0094] The magnetic yoke has:

[0095] a cylindrical yoke tube portion extending in the axial direction; and

[0096] a protrusion portion connected to one axial end of the yoke cylindrical portion and arranged in a plurality at intervals in the circumferential direction;

[0097] Each of the protrusions comprises:

[0098] a protrusion protruding radially inward from one axial end portion of the yoke cylindrical portion; and

[0099] an extension portion extending from the radial inner end portion of the protrusion along the radial inner side surface of the yoke cylindrical portion in the other axial direction,

[0100] The magnet is arranged between the extending portions adjacent to each other in the circumferential direction.

[0101] The protruding stripe portion and the yoke cylindrical portion are integrally formed as a single component (first structure).

[0102] In addition, the rotor of the first structure may also be configured as follows:

[0103] The other axial end portion of the extending portion is arranged axially on the other side than the one axial end portion of the yoke cylindrical portion and axially on one side than the other axial end portion of the yoke cylindrical portion (second configuration).

[0104] In addition, the rotor of the first or second structure may also be configured as follows:

[0105] The axial length of the extending portion is not less than one third of the axial width of the yoke cylindrical portion and not more than the axial width of the yoke cylindrical portion (third configuration).

[0106] In addition, the rotor of any one of the first to third structures may also be constructed as follows:

[0107] It also comprises: a rotor cover portion, which is arranged on the other side of the ridge portion in the axial direction and extends in the radial direction; and

[0108] a rotor cylinder portion extending axially from a radially outer end portion of the rotor cover portion;

[0109] The rotor cylinder surrounds the yoke cylinder and is in contact with the radial outer side surface of the yoke cylinder.

[0110] The other axial end portion of the yoke cylindrical portion is in contact with the rotor cover portion (fourth configuration).

[0111] In addition, the rotor of any one of the first to fourth structures may also be constructed as follows:

[0112] The radial thickness of the extending portion is the same as the radial thickness of the yoke cylindrical portion (fifth structure).

[0113] In addition, the rotor of any one of the first to fifth structures may also be constructed as follows:

[0114] In at least any one of the protruding stripes, a circumferential width of the protruding portion is smaller than a circumferential width of the extending portion (sixth configuration).

[0115] In addition, the motor disclosed in this specification is configured as follows:

[0116] A rotor having any one of the first to sixth structures (seventh structure).

[0117] In addition, the rotor manufacturing method disclosed in this specification is configured as follows:

[0118] The rotor is rotatable around a central axis extending in the axial direction, and a plurality of extensions extending in the axial direction are arranged at intervals in the circumferential direction relative to the radial inner side surface of the yoke cylinder portion extending in the axial direction, and magnets are arranged between the extensions adjacent in the circumferential direction.

[0119] The step of forming the extension portion by bending a column portion with a base of the column portion as a fulcrum, the column portion protruding from one axial end portion of the yoke cylindrical portion and a plurality of columns arranged at intervals in the circumferential direction is provided (eighth structure).

[0120] In addition, the manufacturing method of the rotor of the eighth structure may also be configured to further include the following steps:

[0121] The step of forming a single plate-shaped member from a plate-shaped magnetic body, the single plate-shaped member integrally including a circular plate portion having an opening at the center and the column portion protruding radially inward from the inner edge of the circular plate portion; and

[0122] A step of forming the yoke cylindrical portion by drawing the circular plate portion into a cylindrical shape extending in a normal direction of the plate-shaped member (a ninth configuration).

[0123] In addition, the manufacturing method of the rotor of the eighth structure may also be configured to further include the following steps:

[0124] a step of forming a single plate-shaped member from a plate-shaped magnetic body, the single plate-shaped member integrally including a plate-shaped rectangular portion and the column portion protruding from one side of an outer edge portion of the rectangular portion; and

[0125] A step of forming the yoke cylindrical portion by bending the rectangular portion into a cylindrical shape around an axis parallel to the direction in which the column portion extends (a tenth structure).

[0126] Industrial Applicability

[0127] The present invention is useful for a device including a rotor having a plurality of magnets arranged in a circumferential direction.

Claims

1. A rotor capable of rotating about a central axis extending in an axial direction, characterized in that: The yoke is a cylindrical magnetic body extending in the axial direction, and a plurality of magnets arranged in the circumferential direction are arranged on the radial inner side surface. The magnetic yoke has: a cylindrical yoke tube portion extending in the axial direction; and a protrusion portion connected to one axial end of the yoke cylindrical portion and arranged in a plurality at intervals in the circumferential direction; Each of the protrusions comprises: a protrusion protruding radially inward from one axial end of the yoke cylinder; as well as an extension portion extending from the radial inner end portion of the protrusion along the radial inner side surface of the yoke cylindrical portion in the other axial direction, The magnet is arranged between the extending portions adjacent to each other in the circumferential direction. The protrusion portion and the yoke cylindrical portion are integrally formed as a single component.

2. The rotor according to claim 1, characterized in that The other axial end portion of the extending portion is arranged axially on the other side than the one axial end portion of the yoke cylindrical portion and axially on one side than the other axial end portion of the yoke cylindrical portion.

3. The rotor according to claim 1, characterized in that The axial length of the extension portion is greater than or equal to one third of the axial width of the yoke cylindrical portion and less than or equal to the axial width of the yoke cylindrical portion.

4. The rotor according to claim 1, characterized in that It also comprises: a rotor cover portion, which is arranged on the other side of the ridge portion in the axial direction and extends in the radial direction; and a rotor cylinder portion extending axially from a radially outer end portion of the rotor cover portion; The rotor cylinder surrounds the yoke cylinder and is in contact with the radial outer side surface of the yoke cylinder. The other axial end portion of the yoke cylindrical portion is in contact with the rotor cover portion.

5. The rotor according to claim 1, characterized in that The radial thickness of the extension portion is the same as the radial thickness of the yoke cylindrical portion.

6. The rotor according to claim 1, characterized in that In at least any one of the protruding stripes, a circumferential width of the protruding portion is smaller than a circumferential width of the extending portion.

7. A motor, characterized in that: A rotor according to any one of claims 1 to 6 is provided.

8. A method for manufacturing a rotor, wherein the rotor is rotatable about a central axis extending in an axial direction, wherein a plurality of extension portions extending in an axial direction are arranged at intervals in the circumferential direction relative to the radial inner side surface of a yoke cylindrical portion extending in the axial direction, and a magnet is arranged between the extension portions adjacent in the circumferential direction, The method for manufacturing the rotor is characterized in that: The step of forming the extension portion by bending a column portion with a base of the column portion as a fulcrum, the column portion being a plurality of columns protruding from one axial end portion of the yoke cylindrical portion and arranged at intervals in the circumferential direction.

9. The method for manufacturing a rotor according to claim 8, characterized in that: The following steps are also included: The step of forming a single plate-shaped member from a plate-shaped magnetic body, the single plate-shaped member integrally including a circular plate portion having an opening at the center and the column portion protruding radially inward from the inner edge of the circular plate portion; as well as The step of forming the yoke cylindrical portion by drawing the circular plate portion into a cylindrical shape extending in a normal direction of the plate-shaped member.

10. The method for manufacturing a rotor according to claim 8, characterized in that: The following steps are also included: a step of forming a single plate-shaped member from a plate-shaped magnetic body, the single plate-shaped member integrally including a plate-shaped rectangular portion and the column portion protruding from one side of an outer edge portion of the rectangular portion; and The step of forming the yoke cylindrical portion by bending the rectangular portion into a cylindrical shape around an axis parallel to the direction in which the column portion extends.

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