Method for manufacturing a ring magnet, rotor, motor, blower, and refrigeration device

Abstract

The present invention provides a method for manufacturing a ring magnet that can increase the magnetic force of the ring magnet, as well as a rotor, motor, blower, and refrigeration apparatus. [Solution] The method for manufacturing a ring magnet includes an installation step of installing a first magnet 51 in a first region 72 of a cavity 71 of a mold body 70, and a molding step of forming a second magnet by injecting a bonded magnet material containing magnetically anisotropic magnetic powder into a second region 73 of the cavity 71. A magnetic field generating unit 80 that generates a magnetic field in the cavity 71 has magnetic poles arranged in the circumferential direction A2 of the cavity 71. The second region 73 is a region aligned with the first region 72 in the circumferential direction A2. In the installation step, the first magnet 51 is installed so that the direction of its residual magnetization is aligned with the direction of the magnetic flux of the magnetic field generating unit 80. The molding step is performed after the installation step.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a ring magnet, a rotor, a motor, a blower, and a refrigeration device.

Background Art

[0002] A method of manufacturing a ring magnet by injecting a bonded magnet material into a cylindrical cavity is known (for example, Patent Document 1). The bonded magnet material injected into the cavity is oriented by the magnetic flux of a magnetic field generating portion that generates a magnetic field in the cavity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the bonded magnet material in the cavity, the magnetic flux of the magnetic field generating portion decreases as the distance from the magnetic pole of the magnetic field generating portion increases, so it is difficult for the easy magnetization axes of the magnetic powder to align. Therefore, it is difficult to increase the magnetic force of the ring magnet formed by curing the bonded magnet material.

Means for Solving the Problems

[0005] A first aspect of a method for manufacturing a ring magnet that solves this problem is a method for manufacturing a ring magnet, comprising a mold body having a cylindrical cavity, and a magnetic field generating unit disposed on the inner or outer circumferential surface side of the cavity in the radial direction and generating a magnetic field within the cavity, wherein the molding step includes an installation step of installing a first magnet in a first region of the cavity, and a molding step of molding a second magnet by injecting a bonded magnet material containing magnetically anisotropic magnetic powder into a second region of the cavity, wherein the magnetic field generating unit has magnetic poles arranged in the circumferential direction of the cavity, the second region is a region aligned with the first region in the circumferential direction, the installation step is performed by installing the first magnet such that the direction of the remanent magnetization of the first magnet is aligned with the direction of the magnetic flux of the magnetic field generating unit, and the molding step is performed after the installation step.

[0006] In this configuration, the first magnet is positioned in the cavity such that the direction of its remanent magnetization aligns with the direction of the magnetic flux from the magnetic field generating section. Therefore, when bonded magnet material is injected into the second region of the cavity, the magnetic field of the first magnet makes it easier for the easy magnetization axis of the magnetic powder in the bonded magnet material to align with the magnetic flux from the magnetic field generating section. Consequently, the magnetic force of the ring magnet formed in the second region can be increased.

[0007] A method for manufacturing a ring magnet according to the second aspect is a method for manufacturing a ring magnet according to the first aspect, wherein the installation step includes a first step of placing a magnetic material in the second region, a second step of forming the first magnet in the first region by injecting the bonded magnet material into the first region after the first step, and a third step of removing the magnetic material from the second region after the second step.

[0008] In this configuration, the magnetic material is placed in the second region, and the first magnet is formed in the first region. The magnetic material in the second region makes it easier for the easy magnetization axis of the magnetic powder of the bonded magnet material injected into the first region to align with the magnetic flux of the magnetic field generating section. Therefore, the direction of the remanent magnetization of the first magnet can be aligned with the magnetic flux of the magnetic field generating section.

[0009] A third aspect of the method for manufacturing a ring magnet is the method for manufacturing a ring magnet according to the first aspect, wherein the first magnet is a pre-formed magnet, and in the installation step, the first magnet is placed in the first region such that the direction of the remanent magnetization of the first magnet is aligned with the direction of the magnetic flux of the magnetic field generating unit.

[0010] This configuration allows pre-formed magnets to be molded together with bonded magnets.

[0011] The fourth aspect of the method for manufacturing a ring magnet is the method for manufacturing a ring magnet according to any one of the first to third aspects, wherein the second region is the region of the cavity facing the magnetic pole of the magnetic field generating part, and the first region is the region of the cavity sandwiched between the two second regions in the circumferential direction.

[0012] This configuration makes it possible to increase the magnetic force of the bonded magnets positioned opposite the magnetic poles of the magnetic field generating unit.

[0013] The fifth aspect of the method for manufacturing a ring magnet is the method for manufacturing a ring magnet according to any one of the first to third aspects, wherein the first region is the region of the cavity facing the magnetic pole of the magnetic field generating part, and the second region is the region of the cavity sandwiched between the two first regions in the circumferential direction.

[0014] This configuration makes it possible to increase the magnetic force of the bonded magnet placed between the two magnetic poles of the magnetic field generating unit in the circumferential direction.

[0015] The method for manufacturing a ring magnet according to the sixth aspect is a method for manufacturing a ring magnet according to any one of the first to fifth aspects, further comprising, after the molding step, a removal step of removing the ring magnet from the mold, and after the removal step, a magnetization step of magnetizing the ring magnet.

[0016] This configuration allows the ring magnet to be magnetized during the magnetization process.

[0017] A rotor according to the seventh aspect of solving this problem is a motor rotor, the rotor comprising a cylindrical ring magnet, the ring magnet being an anisotropic magnet having two or more magnetic poles arranged in the circumferential direction of the ring magnet on its inner or outer surface, the ring magnet comprising a third magnet disposed in a region including the magnetic poles on the inner or outer surface, and a fourth magnet disposed in a region sandwiched between the two third magnets in the circumferential direction, the third magnet being a bonded magnet containing magnetic anisotropic magnetic powder having magnetic poles on the radial surface and the circumferential end face of the ring magnet, and the fourth magnet having magnetic poles on the circumferential end face.

[0018] In this configuration, the third magnet has magnetic poles on its radial surface and circumferential end face, and the fourth magnet has magnetic poles on its circumferential end face. Since the fourth magnet is positioned in the region sandwiched between the two third magnets in the circumferential direction, the magnetic flux of the ring magnet easily forms a loop. Therefore, the magnetic force of the ring magnet can be increased.

[0019] The rotor in the eighth viewpoint is the rotor in the seventh viewpoint, in which a yoke is not provided on the rotor.

[0020] This configuration eliminates the need for a yoke on the ring magnet, thereby improving the manufacturing efficiency of the rotor.

[0021] In the rotor of the ninth aspect, in the rotor of the seventh or eighth aspect, the fourth magnet is a bonded magnet made of the same material as the third magnet.

[0022] With this configuration, since the fourth magnet is formed from the same bonded magnet material as the third magnet, the equipment used to inject the bonded magnet material for both the third and fourth magnets can be shared.

[0023] The rotor of the tenth viewpoint is such that, in any one of the rotors from the seventh to the ninth viewpoint, the fourth magnet is a bonded magnet containing magnetically anisotropic magnetic powder, and in the fourth magnet, the circumferential orientation ratio near the circumferential end face is higher than the circumferential orientation ratio near the circumferential center.

[0024] According to this configuration, in the fourth magnet, the magnetic flux near the end face in the circumferential direction is more along the circumferential direction than the magnetic flux near the center in the circumferential direction. Therefore, at the boundary between the third magnet and the fourth magnet, the magnetic flux of the ring magnet easily forms a loop.

[0025] The motor according to the 11th aspect for solving this problem includes any one rotor from the 7th aspect to the 10th aspect and a stator.

[0026] According to this configuration, since the magnetic force of the bonded magnet of the rotor is improved, the rotational characteristics of the motor such as rotational torque and rotational accuracy can be improved.

[0027] The blower according to the 12th aspect for solving this problem includes the motor according to the 11th aspect and a blower device driven by the motor.

[0028] According to this configuration, since the blower device is driven by a motor with improved rotational characteristics, an appropriate rotational force can be obtained for the blower device 10.

[0029] The refrigeration device according to the 13th aspect for solving this problem includes the motor according to the 11th aspect.

[0030] According to this configuration, the refrigeration device can be stably driven by a motor with improved rotational characteristics.

Brief Description of the Drawings

[0031] [Figure 1] It is a schematic diagram of a blower according to the first embodiment. [Figure 2] It is a cross-sectional view of a cross-section along the cylinder axis direction of the ring magnet in the motor of FIG. 1. [Figure 3] It is a schematic diagram of a mold body of a mold used for manufacturing the ring magnet of FIG. 2. [Figure 4] It is a cross-sectional view of a cross-section along line D4-D4 in the mold body of FIG. 3. [Figure 5]Figure 3 is a schematic diagram of the first movable part of the mold. [Figure 6] Figure 3 is a schematic diagram of the second movable part of the mold. [Figure 7] Figure 2 is a first schematic diagram showing part of the installation process in the manufacturing method of the ring magnet. [Figure 8] This is a second schematic diagram showing part of the installation process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 9] This is a third schematic diagram showing part of the installation process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 10] This is a fourth schematic diagram showing part of the installation process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 11] This is a fifth schematic diagram showing part of the installation process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 12] This is a sixth schematic diagram showing part of the installation process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 13] Figure 2 is a seventh schematic diagram showing part of the installation process in the manufacturing method of the ring magnet. [Figure 14] Figure 2 is a first schematic diagram showing a part of the molding process in the manufacturing method of the ring magnet. [Figure 15] This is a second schematic diagram showing a part of the molding process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 16] This is a third schematic diagram showing part of the molding process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 17] Figure 2 is a first schematic diagram showing a part of the removal process in the manufacturing method of the ring magnet. [Figure 18] This is a second schematic diagram showing a part of the removal process in the manufacturing method of the ring magnet shown in Figure 2. [Figure 19] Figure 2 is a plan view of the ring magnet. [Figure 20] Figure 2 is a schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a ring magnet. [Figure 21] This is a first schematic diagram showing a part of the installation process in the manufacturing method of a ring magnet according to the second embodiment. [Figure 22] This is a second schematic diagram showing a part of the installation process in the manufacturing method of a ring magnet according to the second embodiment. [Figure 23] This is a schematic diagram of a mold used for manufacturing a ring magnet according to the third embodiment. [Figure 24] This is a cross-sectional view of the mold shown in Figure 23, along the line D24-D24. [Figure 25] This is a first schematic diagram showing a part of the installation process in the manufacturing method of a ring magnet according to the third embodiment. [Figure 26] This is a second schematic diagram showing a part of the installation process in the manufacturing method of a ring magnet according to the third embodiment. [Figure 27] This is a third schematic diagram showing a part of the installation process in the manufacturing method of a ring magnet according to the third embodiment. [Figure 28] This is a schematic diagram showing a part of the installation process in the manufacturing method of a ring magnet according to the fourth embodiment. [Modes for carrying out the invention]

[0032] <First Embodiment> A method for manufacturing the blower 1, motor 20, rotor 40, and ring magnet 50 according to the first embodiment will be described with reference to Figures 1 to 20.

[0033] <Blower> As shown in Figures 1 and 2, the blower 1 is installed, for example, in the indoor unit of an air conditioner. The air conditioner performs air conditioning operations such as cooling, heating, and dehumidifying the room. The blower 1 performs functions such as drawing in and blowing out air.

[0034] The blower 1 comprises a blower device 10 and a motor 20. The blower device 10 is driven by the motor 20. The blower device 10 has, for example, a cylindrical cross-flow fan 11. Air is drawn in and blown out by the rotation of the cross-flow fan 11.

[0035] <motor> Motor 20 is, for example, an outer rotor type motor. Motor 20 comprises a stator 30 and a rotor 40.

[0036] The stator 30 includes a coil 31, a coil holder 32, a cylindrical first cylindrical portion 33, a disc portion 34, and a stator core 35. The coil 31 is wound around the stator core 35. The stator core 35 is made of a material including a soft magnetic material. The stator core 35 is constructed, for example, by laminating electromagnetic steel sheets in the cylindrical axis direction A1. The coil holder 32 holds the coil 31. The first cylindrical portion 33 is located on the outer circumferential surface side of the coil holder 32. The disc portion 34 connects the coil holder 32 and the first cylindrical portion 33. The coil holder 32, the first cylindrical portion 33, and the disc portion 34 are, for example, made of resin. The coil holder 32, the first cylindrical portion 33, and the disc portion 34 are integrally molded. The stator 30 is provided with a cylindrical arrangement space. The cylindrical arrangement space is the space located between the coil holding portion 32 and the first cylindrical portion 33 of the stator 30. Note that the coil holding portion 32, the first cylindrical portion 33, and the disc portion 34 may be molded individually.

[0037] <Rotor> The rotor 40 includes a cylindrical ring magnet 50. One end of the ring magnet 50 in the cylindrical axis direction A1 is located in a cylindrical arrangement space. The other end of the ring magnet 50 in the cylindrical axis direction A1 is attached to the magnet holder 41.

[0038] The rotor 40 includes, in addition to the ring magnet 50, a magnet holder 41, a second cylindrical portion 42, and a rotating shaft 43. In the cylindrical axis direction A1 of the ring magnet 50, the magnet holder 41 has a first surface on the blower 10 side and a second surface on the opposite side of the first surface. The magnet holder 41 holds the ring magnet 50 on the second surface. The magnet holder 41 is made of, for example, a resin material. The second cylindrical portion 42 is located on the outer circumference side of the ring magnet 50. The rotating shaft 43 is fixed to the magnet holder 41. The rotating shaft 43 is located inside the ring magnet 50. The rotating shaft 43 is located on the inner circumference side of the coil holder 32 of the stator 30. A bearing 21 is positioned between the rotating shaft 43 and the coil holder 32. The rotor 40 is supported by the stator 30 via the bearing 21. The cross-flow fan 11 of the blower 10 is fixed to the first surface of the magnet holder 41.

[0039] When current flows through the coil 31 of the stator 30, a magnetic field is generated. This magnetic field causes the rotor 40, which is equipped with a ring magnet 50, to rotate. This, in turn, causes the cross-flow fan 11 of the blower 10, which is fixed to the magnet holder 41 of the rotor 40, to rotate.

[0040] The rotor 40 is not provided with a yoke. The ring magnet 50 in this embodiment is formed by a bonded magnet.

[0041] <Ring Magnet> The ring magnet 50 is a cylindrical body. The ring magnet 50 is an anisotropic magnet having two or more magnetic poles arranged in the circumferential direction A2 of the ring magnet 50 on its inner or outer surface (see Figure 19). In one example, the ring magnet 50 has two or more magnetic poles arranged in the circumferential direction A2 on its inner surface, and no magnetic poles on its outer surface. In another example, the ring magnet 50 has two or more magnetic poles arranged in the circumferential direction A2 on its outer surface, and no magnetic poles on its inner surface. In this embodiment, the two or more magnetic poles are arranged on the inner surface of the ring magnet 50. The ring magnet 50 is composed of a combination of multiple bond magnets. The lengths of each of the multiple bond magnets in the cylindrical axis direction A1 are equal.

[0042] The ring magnet 50 is composed of three types of bonded magnets. An outer rotor type ring magnet 50 will be used as an example. The first type of bonded magnet has an N pole on its inner circumferential surface. The N pole is located midway along the circumferential direction A2 on the inner circumferential surface of the first type of bonded magnet. The first type of bonded magnet has S poles on both end faces along the circumferential direction A2. The second type of bonded magnet has an S pole on its inner circumferential surface. The S pole is located midway along the circumferential direction A2 on the inner circumferential surface of the second type of bonded magnet. The second type of bonded magnet has N poles on both end faces along the circumferential direction A2. The first and second types of bonded magnets correspond to the third magnet 53, which will be described later.

[0043] A third-type bonded magnet has a magnetic pole on its end face in the circumferential direction A2. In a third-type bonded magnet, one end face in the circumferential direction A2 has a north pole, and the other end face has a south pole. A third-type bonded magnet is positioned between a first-type bonded magnet and a second-type bonded magnet in the circumferential direction A2. The end face containing the north pole of the third-type bonded magnet contacts the end face in the circumferential direction A2 of the first-type bonded magnet. The end face containing the south pole of the third-type bonded magnet contacts the end face in the circumferential direction A2 of the second-type bonded magnet. A third-type bonded magnet corresponds to the fourth magnet 54, which will be described later.

[0044] Bonded magnets contain magnetic anisotropy. Examples of magnetic powder materials include fine powdered or granular ferrite-based or rare-earth-based magnets. Bonded magnets also contain a binder such as nylon resin or PPS (polyphenylene sulfide) resin. The bonded magnet material 50a (see Figure 10), which is a mixture of magnetic anisotropy and a molten binder, hardens to form the bonded magnet.

[0045] <How to manufacture a ring magnet> The manufacturing method for the ring magnet 50 will be explained with reference to Figures 3 to 20. The manufacturing method for the ring magnet 50 includes an installation step, a molding step, an extraction step, and a magnetization step. A molding die 60 is used in the manufacturing of the ring magnet 50.

[0046] [Mold] As shown in Figure 3, the mold 60 comprises a mold body 70 and a magnetic field generating unit 80. The mold body 70 has a cylindrical cavity 71. The mold body 70 is made of a non-magnetic material. An example of a non-magnetic material is non-magnetic stainless steel. The non-magnetic materials described later are also made of the same material.

[0047] As shown in Figure 4, the magnetic field generating unit 80 generates a magnetic field within the cavity 71. The magnetic field generating unit 80 is positioned on either the inner or outer circumferential surface side of the cavity 71 in the radial direction A3. In this embodiment, the magnetic field generating unit 80 is positioned on the inner circumferential surface side of the cavity 71 in the radial direction A3. The magnetic field generating unit 80 is positioned inside the mold body 70. A cylindrical sleeve, which constitutes the inner circumferential surface of the cavity 71, may be positioned between the outer circumferential surface of the magnetic field generating unit 80 and the mold body 70, separately from the mold body 70.

[0048] The cavity 71 has a first region 72 and a second region 73 that is aligned with the first region 72 in the circumferential direction A2. The first region 72 is the region of the cavity 71 sandwiched between the two second regions 73 in the circumferential direction A2. The second region 73 is the region of the cavity 71 facing the magnetic pole of the magnetic field generating unit 80.

[0049] In the cavity 71, the first region 72 and the second region 73 are arranged alternately in the circumferential direction A2. In this embodiment, the length of the second region 73 in the circumferential direction A2 is greater than the length of the first region 72 in the circumferential direction A2.

[0050] The magnetic field generating unit 80 has magnetic poles arranged in the circumferential direction A2 of the cavity 71. The magnetic poles of the magnetic field generating unit 80 are arranged on the inner or outer circumferential surface of the magnetic field generating unit 80. In the manufacture of the ring magnet 50 of this embodiment, the magnetic poles of the magnetic field generating unit 80 are arranged on the outer circumferential surface of the magnetic field generating unit 80. Multiple magnetic poles are formed at regular intervals on the outer circumferential surface of the magnetic field generating unit 80. Specifically, north poles and south poles are formed alternately at regular intervals on the outer circumferential surface of the magnetic field generating unit 80. In the example of Figure 4, the magnetic field generating unit 80 has 8 magnetic poles. In this embodiment, the magnetic field generating unit 80 comprises multiple permanent magnets arranged in the circumferential direction A2 of the cavity 71. The magnetic field generating unit 80 may also include electromagnets.

[0051] The magnetic flux from the magnetic field generating unit 80 extends radially in A3 from the magnetic poles of the magnetic field generating unit 80, intersects the inner surface of the second region 73, and then bends in the circumferential direction A2. Subsequently, the magnetic flux heads toward the end face of the second region 73 in the circumferential direction A2, passing through the two boundaries between the first region 72 and the second region 73. Then, the magnetic flux heads toward the other end face of the first region 72 in the circumferential direction A2, passing through the two boundaries between the first region 72 and the other second region 73. From the end face of the other second region 73 in the circumferential direction A2, the magnetic flux bends inward in the radial direction A3, intersects the inner surface of the other second region 73, and passes through the other magnetic pole. In this way, the magnetic flux intersects the inner surface of the second region 73 and the boundary between the first region 72 and the second region 73. Also, the magnetic flux passes through the first region 72 in the circumferential direction A2.

[0052] As shown in Figure 5, the mold 60 includes a first movable part 90. The first movable part 90 moves relative to the mold body 70, which is held in a fixed position (see Figure 7). The first movable part 90 is made of a non-magnetic material. Inside the first movable part 90, a first spool 91, a first runner 92, and a first gate 93 are formed. The first spool 91 is configured to into which bonded magnetic material 50a is injected. The first runner 92 connects the first spool 91 and the first gate 93. The first gate 93 is an opening that connects to the cavity 71.

[0053] A magnetic material 94 is provided on the first movable part 90. The magnetic material 94 is, for example, a soft magnetic material. Soft magnetic materials include, for example, electrical steel sheets, powdered magnetic cores, nanocrystalline alloys, amorphous alloys, and cast iron. The magnetic material 94 is fixed to the first movable part 90, for example. When the first movable part 90 is attached to the mold body 70, the magnetic material 94 is positioned such that its longitudinal direction is along the cylindrical axis direction A1 of the cavity 71. When the first movable part 90 is attached to the mold body 70, the magnetic material 94 is positioned in the second region 73 of the cavity 71.

[0054] As shown in Figures 4 and 5, the first movable part 90 is provided with a plurality of first gates 93. Each of the plurality of first gates 93 is located in the first region 72 when viewed from the cylindrical axis direction A1 when the first movable part 90 is attached to the mold body 70. Each of the plurality of first gates 93 is positioned at a different location in the circumferential direction A2 from each of the magnetic poles of the magnetic field generating part 80. In this embodiment, each of the plurality of first gates 93 is positioned midway between adjacent magnetic poles of the magnetic field generating part 80 in the circumferential direction A2. The first movable part 90 is provided with a plurality of magnetic materials 94. Each of the plurality of magnetic materials 94 is positioned at a different location in the circumferential direction A2 from each of the plurality of first gates 93.

[0055] As shown in Figure 6, the mold 60 includes a second movable part 100. The second movable part 100 moves relative to the mold body 70, which is held in a fixed position (see Figure 14). The second movable part 100 is made of a non-magnetic material. Inside the second movable part 100, a second spool 101, a second runner 102, and a second gate 103 are formed. The second spool 101 is configured to into which bonded magnet material 50a is injected. The second runner 102 connects the second spool 101 and the second gate 103. The second gate 103 is an opening that connects to the cavity 71.

[0056] As shown in Figures 4 and 6, the second movable part 100 is provided with a plurality of second gates 103. Each of the plurality of second gates 103 is located in the second region 73 when viewed from the cylindrical axis direction A1 when the second movable part 100 is attached to the mold body 70. Each of the plurality of second gates 103 is positioned at the same location in the circumferential direction A2 as each of the magnetic poles of the magnetic field generating part 80.

[0057] [Manufacturing method] Next, the method for manufacturing the ring magnet 50 will be described. The method for manufacturing the ring magnet 50 includes, as described above, an installation step, a molding step, an extraction step, and a magnetization step.

[0058] In the installation process shown in Figures 7 to 13, the first magnet 51 is placed in the first region 72 of the cavity 71. The phrase "place the first magnet 51 in the first region 72 of the cavity 71" in the installation process includes both a first and a second meaning. The first meaning is to form the first magnet 51 in the first region 72 of the cavity 71. The second meaning is to place the first magnet 51 as a physical object in the first region 72 of the cavity 71. In this embodiment, "place the first magnet 51 in the first region 72 of the cavity 71" in the installation process refers to the first meaning. That is, in the installation process of this embodiment, the first magnet 51 is formed in the first region 72 of the cavity 71.

[0059] In the installation process, the first magnet 51 is positioned such that the direction of its remanent magnetization aligns with the direction of the magnetic flux of the magnetic field generating unit 80. That is, in the installation process, the first magnet 51 is formed in the first region 72 of the cavity 71 such that the direction of its remanent magnetization aligns with the direction of the magnetic flux of the magnetic field generating unit 80.

[0060] The installation process will now be explained in detail. The installation process includes a first step, a second step, and a third step. As shown in Figures 7 to 9, in the first step of the installation process, the magnetic material 94 is placed in the second region 73. As shown in Figure 7, in the first step, the first movable part 90 is attached to the mold body 70. Note that Figure 7 shows a cross-sectional view of the mold 60 along the line D7-D7 in Figure 4. As shown in Figure 8, the magnetic material 94 is placed in the second region 73 by attaching the first movable part 90 to the mold body 70. As shown in Figure 9, the first gate 93 is located in the first region 72. Note that Figure 9 shows a cross-sectional view of the mold 60 along the line D9-D9 in Figure 8.

[0061] As shown in Figures 10 and 11, the second step in the installation process is performed after the first step. In the second step, the first magnet 51 is formed in the first region 72 by injecting bonded magnet material 50a into the first region 72. Specifically, as shown in Figure 10, the bonded magnet material 50a is injected into the first spool 91. Figure 10 shows a cross-sectional view of the mold 60 in a cross section along the line D10-D10 in Figure 9. In the cross-sectional view of Figure 10, the end face of the magnetic material 94 located further back in the paper than the line D10-D10 in Figure 9 is visible. In the second step, after the bonded magnet material 50a is injected into the first spool 91 of the first movable part 90, it is guided to the first gate 93 by the first runner 92, passes through the first gate 93 and flows into the first region 72 of the cavity 71. As shown in Figure 11, the first magnet 51 is formed by the curing of the bonded magnetic material 50a in the first region 72 of the cavity 71.

[0062] As shown in Figure 9, the magnetic material 94 is arranged from the inner surface to the outer surface of the cavity 71. In other words, the bonded magnet material 50a injected into the first region 72 of the cavity 71 in the second step does not flow into the second region 73 because it is blocked by the magnetic material 94. For this reason, the first magnet 51 is formed only in the first region 72.

[0063] The bonded magnet material 50a contains magnetically anisotropic magnetic powder. The magnetic powder has an easy magnetization axis. The length of the magnetic powder in a second direction perpendicular to the easy magnetization axis is longer than the length of the magnetic powder in a first direction along the easy magnetization axis. In other words, the magnetic powder is flattened. The easy magnetization axis of the magnetic powder of the bonded magnet material 50a that flows into the cavity 71 is aligned with the flow direction of the bonded magnet material 50a. Note that the magnetic powder of the bonded magnet material 50a injected in the installation and molding processes is not magnetized.

[0064] The easy magnetization axis of the magnetic powder is aligned with the flow direction of the bonded magnet material 50a, while the magnetic powder is also affected by the magnetic field of the magnetic field generating unit 80. The magnetic field of the magnetic field generating unit 80 forces the magnetic powder so that its easy magnetization axis aligns with the magnetic flux of the magnetic field generating unit 80. As described above, in the mold 60 of this embodiment, the magnetic flux intersects at the boundary between the first region 72 and the second region 73. Since the magnetic material 94 is arranged in the second region 73, the magnetic field of the magnetic field generating unit 80 causes the end face of the magnetic material 94 in the circumferential direction A2 to become a magnetic pole. The magnetic powder of the bonded magnet material 50a injected into the first region 72 is oriented by the magnetic pole of the magnetic material 94 in the second region 73.

[0065] As shown in Figures 12 and 13, the third step in the installation process is performed after the second step. In the third step, the magnetic material 94 is removed from the second region 73. As shown in Figure 12, the magnetic material 94 is removed from the cavity 71 by removing the first movable part 90 from the mold body 70. As shown in Figure 13, the first magnet 51, which has a magnetic pole on its end face in the circumferential direction A2, remains in the cavity 71. The direction of the residual magnetization of the first magnet 51 is the circumferential direction A2. In the first region 72 where the first magnet 51 is provided, the direction of the magnetic flux of the magnetic field generating unit 80 is the circumferential direction A2. By providing the first magnet 51 in the first region 72, the direction of the residual magnetization of the first magnet 51 aligns with the direction of the magnetic flux of the magnetic field generating unit 80. Note that Figure 13 shows a cross-sectional view of the mold 60 in a cross section along the line D13-D13 in Figure 12.

[0066] When the first movable part 90 is removed from the mold body 70, the first magnet 51 in the cavity 71 and the bonded magnet of the first runner 92 are separated. As a result, a first gate mark 55 is formed on the end face of the first magnet 51 in the cylindrical axis direction A1 (see Figure 19).

[0067] As described above, the first magnet 51 is formed in the first region 72 during the installation process. That is, the first magnet 51 is provided in the first region 72.

[0068] The molding process shown in Figures 14 to 16 is performed after the installation process. In the molding process, the second magnet 52 is formed by injecting bonded magnet material 50a into the second region 73 of the cavity 71. As shown in Figure 14, the second movable part 100 is attached to the mold body 70 in the molding process. Note that Figure 14 shows a cross-sectional view of the mold 60 along the line D14-D14 in Figure 13. As shown in Figure 15, the bonded magnet material 50a is injected into the second spool 101 of the second movable part 100, then guided to the second gate 103 by the second runner 102, and flows through the second gate 103 into the second region 73 of the cavity 71. As shown in Figure 16, the second magnet 52 is formed by the hardening of the bonded magnet material 50a in the second region 73 of the cavity 71. The second magnet 52 is molded integrally with the first magnet 51.

[0069] As shown in Figures 17 and 18, the removal process is performed after the molding process. In the removal process, the ring magnet 50 is removed from the mold 60. As shown in Figure 17, after the bonded magnet material 50a has hardened, the second movable part 100 is removed from the mold body 70. At this time, the second magnet 52 in the cavity 71 and the bonded magnet of the second runner 102 are separated. As a result, a second gate mark 56 is formed on the end face of the ring magnet 50 in the cylindrical axis direction A1 (see Figure 19). As shown in Figure 18, after the second movable part 100 has been removed from the mold body 70, the ring magnet 50 is removed from the cavity 71.

[0070] The magnetization process is performed after the extraction process. In the magnetization process, the ring magnet 50 is magnetized. Before magnetizing the ring magnet 50, the ring magnet 50 may be demagnetized.

[0071] <Characteristics of ring magnets> Figure 19 is a plan view of the ring magnet 50 as seen from the side where the first gate mark 55 and the second gate mark 56 are formed in the cylindrical axis direction A1. The ring magnet 50 comprises a third magnet 53 and a fourth magnet 54. The third magnet 53 and the fourth magnet 54 are adjacent in the circumferential direction A2. In this embodiment, the third magnet 53 is a second magnet 52 formed in the molding process. The fourth magnet 54 is a first magnet 51 formed in the second step of the installation process.

[0072] The third magnet 53 is positioned in the ring magnet 50 in a region that includes the magnetic poles on either the inner or outer circumferential surface. In this embodiment, the third magnet 53 is positioned in the ring magnet 50 in a region that includes the magnetic poles on the inner circumferential surface. The region that includes the magnetic poles on the inner circumferential surface overlaps with the second region 73 of the cavity 71 during the manufacturing of the ring magnet 50. The third magnet 53 is a bonded magnet.

[0073] The fourth magnet 54 is positioned in the region between the two third magnets 53 in the circumferential direction A2. In this embodiment, the region between the two third magnets 53 in the circumferential direction A2 overlaps with the first region 72 of the cavity 71 during the manufacturing of the ring magnet 50.

[0074] The fourth magnet 54 is a bonded magnet. The fourth magnet 54 is, for example, a bonded magnet made of the same material as the third magnet 53. In this embodiment, the equipment used to inject the bonded magnet material 50a in the second step of the installation process is the same as the equipment used to inject the bonded magnet material 50a in the molding process.

[0075] As shown in Figure 20, the third magnet 53 has magnetic poles on the circumferential surface 53a in the radial direction A3 and on the end surface 53b in the circumferential direction A2 of the ring magnet 50. In this embodiment, the circumferential surface 53a is the inner circumferential surface. The fourth magnet 54 has a magnetic pole on the end surface 54a in the circumferential direction A2. The white arrows in Figure 20 indicate the direction along which the easy magnetization axis of the magnetic powder of the bonded magnet lies. The easy magnetization axis of the magnetic powder in the third magnet 53 lies along the radial direction A3 in the middle of the circumferential direction A2 on the circumferential surface 53a of the third magnet 53. The easy magnetization axis of the magnetic powder in the third magnet 53 tilts towards the circumferential direction A2 as it approaches the end surface 53b of the third magnet 53 from the middle of the circumferential direction A2 on the circumferential surface 53a of the third magnet 53, and aligns with the circumferential direction A2 on the circumferential surface 53a of the third magnet 53. The easy magnetization axis of the magnetic powder in the fourth magnet 54 is aligned in the circumferential direction A2 from one end face 54a of the fourth magnet 54 to the other.

[0076] One end face 53b of the adjacent third magnet 53 and one end face 54a of the fourth magnet 54 are the south poles and the other is the north pole. The end face 54a of the fourth magnet 54 in the circumferential direction A2 is in contact with the end face 53b of the third magnet 53 in the circumferential direction A2. An interface is formed between the end face 54a of the fourth magnet 54 and the end face 53b of the third magnet 53 in the circumferential direction A2.

[0077] In the fourth magnet 54, the orientation ratio of the circumferential direction A2 near the end face 54a of the circumferential direction A2 is higher than the orientation ratio of the circumferential direction A2 near the center of the circumferential direction A2. The area near the center of the circumferential direction A2 in the fourth magnet 54 is, for example, near the first gate mark 55 of the first magnet 51, which is the fourth magnet 54. When the ring magnet 50 is manufactured, the first magnet 51, which is the fourth magnet 54, is formed in the molding process, and the magnetic material 94 is placed in the second region 73. Regarding the influence of the magnetic field of the magnetic field generating unit 80, the influence near the end of the circumferential direction A2 in the second region 73 is greater than the influence near the center of the circumferential direction A2 in the second region 73 because the end of the second region 73 is closer to the magnetic material 94 than the center. The area near the center of the circumferential direction A2 in the fourth magnet 54 is formed near the center of the circumferential direction A2 in the second region 73 when the ring magnet 50 is manufactured. Furthermore, the area near the end face 54a of the fourth magnet 54 in the circumferential direction A2 is formed near the end of the circumferential direction A2 in the second region 73 during the manufacturing of the ring magnet 50. For this reason, in the fourth magnet 54, the area near the end face 54a of the circumferential direction A2 is more susceptible to the influence of the magnetic flux in the circumferential direction A2 than the area near the center of the circumferential direction A2 during the manufacturing of the ring magnet 50.

[0078] In this embodiment, orientation means that the easy magnetization axis of the magnetic powder contained in the bonded magnet material 50a is aligned in a predetermined direction. The orientation ratio is defined by the following equation (1) as the average value of the orientation component of each magnetic powder with respect to the predetermined direction.

[0079]

number

[0080] X is the orientation factor. N is the total number of magnetic particles contained in any given region. θ is the angle between a given direction and the easy magnetization axis of each magnetic particle. Any given region is defined, for example, by the observation range of a scanning electron microscope (SEM).

[0081] <Operation of the Embodiment> The first operation of this embodiment will now be described. In the manufacturing method of the ring magnet 50, a first magnet 51 is provided in the first region 72 when the bonded magnet material 50a is injected into the second region 73 of the cavity 71. The first magnet 51 is provided so that the direction of its residual magnetization is aligned with the direction of the magnetic flux of the magnetic field generating unit 80. As a result, the magnetic powder of the bonded magnet material 50a in the second region 73 is affected not only by the magnetic flux of the magnetic field generating unit 80 but also by the magnetic flux of the first magnet 51, thereby improving the orientation of the bonded magnet material 50a in the second region 73.

[0082] The second operation of this embodiment will now be described. In the second step of the installation process, when the bonded magnet material 50a is injected into the first region 72 of the cavity 71, magnetic material 94 is placed in the second region 73. By placing magnetic material 94 in the second region 73 of the cavity 71, the magnetic resistance between the magnetic poles of the magnetic field generating unit 80 is reduced, and the magnetic flux density of the first region 72 located between the two magnetic materials 94 in the circumferential direction A2 is improved. As a result, the magnetic powder of the bonded magnet material 50a that becomes the first magnet 51 is more easily oriented compared to when magnetic material 94 is not placed in the cavity 71.

[0083] The third function of this embodiment will now be described. As the magnetic flux from the magnetic field generating unit 80 passes through the magnetic material 94, the magnetic flux passing through the first region 72 located between the two magnetic materials 94 in the circumferential direction A2 is formed to align with the circumferential direction A2. Therefore, during the manufacturing of the ring magnet 50, the magnetic flux from the magnetic field generating unit 80 is less likely to occur in the region radially outward from the outer surface of the cavity 71. As a result, leakage flux of the finished ring magnet 50 can be suppressed, and when the ring magnet 50 is used in the rotor 40, a yoke is not required for the rotor 40.

[0084] <Effects of the Embodiment> The effects of this embodiment will now be explained. (1-1) A mold 60 is used to manufacture the ring magnet 50. The mold 60 comprises a mold body 70 and a magnetic field generating unit 80. The mold body 70 has a cylindrical cavity 71. The magnetic field generating unit 80 is positioned on the inner or outer circumferential surface side of the cavity 71 in the radial direction A3 of the cavity 71. The magnetic field generating unit 80 generates a magnetic field in the cavity 71. The magnetic field generating unit 80 has magnetic poles arranged in the circumferential direction A2 of the cavity 71. The method for manufacturing the ring magnet 50 includes an installation step and a molding step. In the installation step, a first magnet 51 is placed in a first region 72 of the cavity 71. In the installation step, the first magnet 51 is placed such that the direction of its remanent magnetization is aligned with the direction of the magnetic flux of the magnetic field generating unit 80. The molding step is performed after the installation step. In the molding process, the second magnet 52 is formed by injecting a bonded magnet material 50a containing magnetically anisotropic magnetic powder into the second region 73 of the cavity 71. The second region 73 is a region aligned with the first region 72 in the circumferential direction A2.

[0085] In this configuration, the first magnet 51 is placed in the cavity 71 such that the direction of its residual magnetization aligns with the direction of the magnetic flux of the magnetic field generating unit 80. Therefore, when the bonded magnet material 50a is injected into the second region 73 of the cavity 71, the magnetic field of the first magnet 51 makes it easier for the easy magnetization axis of the magnetic powder of the bonded magnet material 50a to align with the magnetic flux of the magnetic field generating unit 80. Consequently, the magnetic force of the ring magnet 50 formed in the second region 73 can be increased.

[0086] (1-2) The installation process includes a first step, a second step, and a third step. In the first step, magnetic material 94 is placed in the second region 73. The second step is performed after the first step. In the second step, the first magnet 51 is formed in the first region 72 by injecting bonded magnet material 50a into the first region 72. The third step is performed after the second step. In the third step, magnetic material 94 is removed from the second region 73.

[0087] In this configuration, the magnetic material 94 is placed in the second region 73, and the first magnet 51 is formed in the first region 72. The magnetic material 94 in the second region 73 makes it easier for the magnetization axis of the magnetic powder of the bonded magnet material 50a injected into the first region 72 to align with the magnetic flux of the magnetic field generating unit 80. Therefore, the direction of the remanent magnetization of the first magnet 51 can be aligned with the magnetic flux of the magnetic field generating unit 80.

[0088] (1-3) The second region 73 is the region of the cavity 71 facing the magnetic pole of the magnetic field generating unit 80. The first region 72 is the region of the cavity sandwiched between the two second regions 73 in the circumferential direction A2.

[0089] This configuration makes it possible to increase the magnetic force of the bonded magnets, which are positioned opposite the magnetic poles of the magnetic field generating unit 80.

[0090] (1-4) The method for manufacturing the ring magnet 50 further includes an extraction step and a magnetization step. The extraction step is performed after the molding step. In the extraction step, the ring magnet 50 is removed from the molding die 60. The magnetization step is performed after the extraction step. In the magnetization step, the ring magnet 50 is magnetized.

[0091] With this configuration, the ring magnet 50 can be magnetized during the magnetization process.

[0092] (1-5) The rotor 40 includes a cylindrical ring magnet 50. The ring magnet 50 is a polar anisotropic magnet. A polar anisotropic magnet has two or more magnetic poles on its inner or outer surface, aligned in the circumferential direction A2 of the ring magnet 50. The ring magnet 50 includes a third magnet 53 and a fourth magnet 54. The third magnet 53 is positioned in the ring magnet 50 in a region that includes the magnetic poles on its inner or outer surface. The fourth magnet 54 is positioned in a region sandwiched between the two third magnets 53 in the circumferential direction A2. The third magnet 53 has magnetic poles on the circumferential surface 53a in the radial direction A3 of the ring magnet 50 and on the end surface 53b in the circumferential direction A2. The third magnet 53 is a bonded magnet containing magnetic anisotropic magnetic powder. The fourth magnet 54 has a magnetic pole on the end surface 54a in the circumferential direction A2.

[0093] In this configuration, the third magnet 53 has magnetic poles on its circumferential surface 53a in the radial direction A3 and its end face 53b in the circumferential direction A2, and the fourth magnet 54 has a magnetic pole on its end face 54a in the circumferential direction A2. Since the fourth magnet 54 is positioned in the region sandwiched between the two third magnets 53 in the circumferential direction A2, the magnetic flux of the ring magnet 50 easily forms a loop. Therefore, the magnetic force of the ring magnet 50 can be increased.

[0094] (1-6) The rotor 40 is not provided with a yoke.

[0095] With this configuration, since a yoke is not provided on the ring magnet 50, the manufacturing efficiency of the rotor 40 can be improved.

[0096] (1-7) The fourth magnet 54 is a bonded magnet made of the same material as the third magnet 53.

[0097] With this configuration, since the fourth magnet 54 is formed from the same bonded magnet material 50a as the third magnet 53, the equipment used to inject the bonded magnet material 50a for both the third magnet 53 and the fourth magnet 54 can be shared.

[0098] (1-8) The fourth magnet 54 is a bonded magnet containing magnetic anisotropic magnetic powder. In the fourth magnet 54, the orientation ratio of the circumferential direction A2 near the end face of the circumferential direction A2 is higher than the orientation ratio of the circumferential direction A2 near the center of the circumferential direction A2.

[0099] In this configuration, in the fourth magnet 54, the magnetic flux near the end face of the circumferential direction A2 is more aligned with the circumferential direction A2 than the magnetic flux near the center of the circumferential direction A2. Therefore, at the boundary between the third magnet 53 and the fourth magnet 54, the magnetic flux of the ring magnet 50 easily forms a loop.

[0100] (1-9) The motor 20 comprises a rotor 40 and a stator 30.

[0101] With this configuration, the magnetic force of the bonded magnets of the rotor 40 is improved, which in turn improves the rotational characteristics of the motor 20, such as rotational torque and rotational accuracy.

[0102] (1-10) The blower 1 comprises a motor 20 and a blower device 10. The blower device 10 is driven by the motor 20.

[0103] With this configuration, the blower 10 is driven by the motor 20, which has improved rotational characteristics, thus providing the blower 10 with an appropriate rotational force.

[0104] <Second Embodiment> With reference to Figures 21 and 22, the manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 according to the second embodiment will be described. Components in this embodiment that are common to the first embodiment are denoted by the same reference numerals as in the first embodiment, and redundant explanations are omitted.

[0105] In this embodiment, the positions of the first region 72 and the second region 73 in the cavity 71 differ from those in the first embodiment. The first region 72 is the region of the cavity 71 facing the magnetic pole of the magnetic field generating unit 80. The second region 73 is the region of the cavity 71 sandwiched between the two first regions 72 in the circumferential direction A2. In other words, the first region 72 in the first embodiment corresponds to the second region 73 in this embodiment. Also, the second region 73 in the first embodiment corresponds to the first region 72 in this embodiment.

[0106] In the ring magnet 50 of this embodiment, the third magnet 53 is the first magnet 51 which is formed in the second step of the installation process. Also, the fourth magnet 54 is the second magnet 52 which is formed in the molding process.

[0107] Figure 21 is a cross-sectional view of the mold body 70 as seen from the cylindrical axis direction A1, in the state in which the first movable part 90 is attached to the mold body 70 in the first step of the installation process, as shown in Figure 9 of the first embodiment. In this embodiment, the magnetic material 94 does not overlap with the magnetic poles of the magnetic field generating part 80 in the circumferential direction A2.

[0108] Figure 22 is a cross-sectional view of the mold body 70 as seen from the cylindrical axis direction A1, with the first magnet 51 positioned in the second step of the installation process, as shown in Figure 13 of the first embodiment. In this embodiment, the first magnet 51 is positioned in the cavity 71 so as to face the magnetic poles of the ring magnet 50.

[0109] <Effects of the Embodiment> The effects of this embodiment will now be explained. (2) The first region 72 is the region of the cavity facing the magnetic pole of the magnetic field generating unit 80. The second region 73 is the region of the cavity 71 sandwiched between the two first regions 72 in the circumferential direction A2.

[0110] This configuration makes it possible to increase the magnetic force of the bond magnet placed between the two magnetic poles of the magnetic field generating unit 80 in the circumferential direction A2.

[0111] <Third Embodiment> Referring to Figures 23 to 27, the manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 according to the third embodiment will be described. Components in this embodiment that are common to the first embodiment are denoted by the same reference numerals as in the first embodiment, and redundant explanations are omitted.

[0112] In this embodiment, the phrase "place the first magnet 51 in the first region 72 of the cavity 71" in the installation process has the second meaning. That is, in the installation process of this embodiment, the first magnet 51 as a physical object is placed in the first region 72 of the cavity 71. In the first embodiment, the first magnet 51 was a bonded magnet formed in the installation process, but in this embodiment, the first magnet 51 is a pre-formed magnet 57. The magnet 57 is already magnetized. The magnet 57 is a permanent magnet such as a neodymium magnet, samarium cobalt magnet, alnico magnet, or ferrite magnet. The magnet 57 may also be a bonded magnet. The magnet 57 as the first magnet 51 is molded integrally with the second magnet 52. The magnet 57 in this embodiment is a third type bonded magnet.

[0113] As shown in Figures 23 and 24, in this embodiment, the first movable part 90 is omitted from the mold 60. The mold 60 in this embodiment comprises a mold body 70, a magnetic field generating unit 80, and a second movable part 100.

[0114] As shown in Figures 25 to 27, the first magnet 51, which is a magnet 57, is placed in the cavity 71 of the mold body 70 during the installation process. As shown in Figure 25, the first magnet 51, which is a magnet 57, is inserted into the cavity 71 along the cylindrical axis direction A1. The magnet 57 has the same shape as the first region 72 of the cavity 71. As shown in Figure 26, the first magnet 51, which is a magnet 57, is placed in the first region 72 of the cavity 71.

[0115] As shown in Figure 27, during the installation process, the first magnet 51 is positioned in the first region 72 such that the direction of the remanent magnetization of the first magnet 51 aligns with the direction of the magnetic flux of the magnetic field generating unit 80. Figure 27 shows a cross-sectional view of the mold 60 along the line D27-D27 in Figure 26. In this embodiment, the direction of the remanent magnetization of the first magnet 51 aligns with the circumferential direction A2. In this embodiment, the first magnet 51 is formed in an arc shape when viewed from the cylindrical axis direction A1. The first magnet 51 has magnetic poles on both end faces in the circumferential direction A2. The first magnet 51 is positioned so that the end faces, which are the magnetic poles, face the circumferential direction A2 of the cavity 71. As a result, the direction of the remanent magnetization of the first magnet 51 aligns with the direction of the magnetic flux of the magnetic field generating unit 80 in the first region 72.

[0116] <Operation of the Embodiment> The operation of this embodiment will now be explained. In this embodiment, a pre-formed magnet 57 is placed in the first region 72 of the cavity 71, and bonded magnet material 50a is injected into the second region 73. Since the direction of the residual magnetization of the magnet 57 is aligned with the direction of the magnetic flux of the magnetic field generating unit 80, the orientation of the bonded magnet material 50a in the second region 73 is improved by the magnet 57.

[0117] <Effects of the Embodiment> The effects of this embodiment will now be explained. (3) The first magnet 51 is a pre-formed magnet. In the installation process, the first magnet 51 is placed in the first region 72 such that the direction of the remanent magnetization of the first magnet 51 is aligned with the direction of the magnetic flux of the magnetic field generating unit 80.

[0118] This configuration allows the pre-formed magnet 57 to be molded integrally with the bonded magnet.

[0119] <Fourth Embodiment> Referring to Figure 28, the manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 according to the fourth embodiment will be described. Components in this embodiment that are common with the third embodiment are denoted by the same reference numerals as in the third embodiment, and redundant explanations are omitted.

[0120] In this embodiment, the positions of the first region 72 and the second region 73 in the cavity 71 differ from those in the third embodiment. The first region 72 is the region of the cavity facing the magnetic pole of the magnetic field generating unit 80. In other words, the first region 72 in the third embodiment corresponds to the second region 73 in this embodiment. Also, the second region 73 in the third embodiment corresponds to the first region 72 in this embodiment. The magnets 57 in this embodiment are a first-type bonded magnet and a second-type bonded magnet.

[0121] Figure 28 is a cross-sectional view of the mold body 70 as seen from the cylindrical axis direction A1, with the magnet 57, which is the first magnet 51, positioned during the installation process as shown in Figure 27 of the third embodiment. In this embodiment, the magnet 57, which is the first magnet 51, is positioned in the cavity 71 so as to face the magnetic poles of the ring magnet 50.

[0122] <Effects of the Embodiment> The effects of this embodiment will now be explained. (4) In the installation process, the first magnet 51 is positioned in the first region 72 such that the direction of the remanent magnetization of the first magnet 51 is aligned with the direction of the magnetic flux of the magnetic field generating unit 80. The first region 72 is the region of the cavity facing the magnetic pole of the magnetic field generating unit 80. The second region 73 is the region of the cavity 71 sandwiched between the two first regions 72 in the circumferential direction A2.

[0123] This configuration makes it possible to increase the magnetic force of the bond magnet positioned between the two magnetic poles of the magnetic field generating unit 80 in the circumferential direction A2.

[0124] <Variation> The manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 of this disclosure may also be modified in ways other than those described above, such as those shown below, or in combination of at least two mutually non-inconsistent modifications.

[0125] The length of the first region 72 in the circumferential direction A2, and the length of the second region 73 in the circumferential direction A2, may be changed as desired.

[0126] The position of the first gate 93 may be arbitrarily changed as long as it is within the first region 72 as viewed from the cylinder axis direction A1. Similarly, the position of the second gate 103 may be arbitrarily changed as long as it is within the second region 73 as viewed from the cylinder axis direction A1.

[0127] In this embodiment, the lengths of the multiple bonded magnets in the cylindrical axis direction A1 are equal, but the lengths of the multiple bonded magnets in the cylindrical axis direction A1 may be different. For example, the lengths of the first magnet 51 and the second magnet 52 in the cylindrical axis direction A1 may be different, the lengths of the multiple first magnets 51 in the cylindrical axis direction A1 may be different, and the lengths of the multiple second magnets 52 in the cylindrical axis direction A1 may be different.

[0128] In the first or second embodiment, the magnetic material 94 may be composed of a magnetized magnet in addition to a soft magnetic material. As the magnet in this modification, a magnet can be used whose shape, material, etc., is similar to that of the magnet 57 in the third embodiment. As the material for the magnet in this modification, for example, neodymium magnets, samarium cobalt magnets, alnico magnets, ferrite magnets, and bonded magnets can be used.

[0129] In the first or second embodiment, a magnetization step for magnetizing the first magnet 51 may be performed after the molding of the first magnet 51 and before the molding of the second magnet 52.

[0130] In the first or second embodiment, the magnetic material 94 may be configured to be removable from the first movable part 90. In this modification, magnetic materials 94 of different sizes may be selectively attached based on the shapes of the first region 72 and the second region 73.

[0131] In the first and second embodiments, the first movable part 90 and the second movable part 100 are provided separately, but they may be configured as a single movable part. The movable part of this modified example has a first gate 93 and a second gate 103. In the installation process, the movable part of this modified example is configured to be able to close the second gate 103 and to be able to attach the magnetic material 94. In the molding process, the movable part of this modified example is configured to be able to close the first gate 93.

[0132] In the first and second embodiments, the first magnet 51 and the second magnet 52 are bonded magnets made of the same material, but they may be bonded magnets made of different materials.

[0133] In the manufacturing method of the ring magnet 50, the magnetization step may be omitted. In this modified example, the ring magnet 50 may be magnetized during the molding step.

[0134] The motor 20 may be of the inner rotor type. In this modified example, two or more magnetic poles are arranged on the outer surface of the ring magnet 50. In this modified example, the magnetic field generating unit 80 is located on the outer surface side of the cavity 71 in the radial direction A3.

[0135] The motor 20 may be used to drive the fan of a blower installed in the outdoor unit of an air conditioner.

[0136] The blower 10 may have an impeller other than the cross-flow fan 11. Examples of impellers include the cross-flow fan, propeller fan, turbo fan, and sirocco fan of each embodiment.

[0137] The refrigeration system may include a motor 20. Examples of refrigeration systems include air conditioners, water heaters, chiller units, and cooling devices for cooling the air inside a storage area, as in each embodiment. The air inside a storage area refers to the air inside a refrigerator, freezer, display case, container, etc. These refrigeration systems include a compressor. The motor 20 is used as a motor for the compressor of the refrigeration system. With this configuration, the refrigeration system can be stably driven by the motor 20, which has improved rotational characteristics. [Explanation of Symbols]

[0138] 1...Blower, 10...Blowering device, 20...Motor, 30...Stator, 40...Rotor, 50...Ring magnet, 50a...Bonded magnet material, 51...First magnet, 52...Second magnet, 53...Third magnet, 54...Fourth magnet, 57...Magnet, 60...Mold, 70...Mold body, 71...Cavity, 72...First region, 73...Second region, 80...Magnetic field generating unit, 94...Magnetic material.

Claims

1. A method for manufacturing a ring magnet (50), A mold (60) comprising a mold body (70) having a cylindrical cavity (71), and a magnetic field generating unit (80) disposed on the inner or outer circumferential side of the cavity (71) in the radial direction (A3) of the cavity (71) and generating a magnetic field within the cavity (71), Installation step of providing a first magnet (51) in the first region (72) of the cavity (71), The process includes a molding step of forming a second magnet (52) by injecting a bonded magnet material (50a) containing magnetically anisotropic magnetic powder into a second region (73) of the cavity (71), The magnetic field generating unit (80) has magnetic poles arranged in the circumferential direction (A2) of the cavity (71), The second region (73) is a region that is aligned with the first region (72) in the circumferential direction (A2), In the installation step, the first magnet (51) is positioned such that the direction of the remanent magnetization of the first magnet (51) is aligned with the direction of the magnetic flux of the magnetic field generating unit (80). The molding process is performed after the installation process. A method for manufacturing ring magnets.

2. The aforementioned installation process is, The first step is to place a magnetic material (94) in the second region (73), A second step is performed after the first step, in which the bonded magnet material (50a) is injected into the first region (72) to form the first magnet (51) in the first region (72), The process includes, after the second step, a third step of removing the magnetic material (94) from the second region (73), A method for manufacturing a ring magnet according to claim 1.

3. The first magnet (51) is a pre-formed magnet (57), In the installation step, the first magnet (51) is placed in the first region (72) such that the direction of the remanent magnetization of the first magnet (51) is aligned with the direction of the magnetic flux of the magnetic field generating unit (80). A method for manufacturing a ring magnet according to claim 1.

4. The second region (73) is the region of the cavity (71) facing the magnetic pole of the magnetic field generating unit (80), The first region (72) is the region of the cavity (71) sandwiched between the two second regions (73) in the circumferential direction (A2). A method for manufacturing a ring magnet according to any one of claims 1 to 3.

5. The first region (72) is the region of the cavity facing the magnetic pole of the magnetic field generating unit (80), The second region (73) is the region of the cavity (71) sandwiched between the two first regions (72) in the circumferential direction (A2). A method for manufacturing a ring magnet according to any one of claims 1 to 3.

6. After the molding process, there is a removal process in which the ring magnet (50) is removed from the molding die (60), The process further includes, after the extraction step, a magnetization step of magnetizing the ring magnet (50), A method for manufacturing a ring magnet according to any one of claims 1 to 3.

7. It is the rotor of a motor, The rotor (40) is equipped with a cylindrical ring magnet (50), The ring magnet (50) is An anisotropic magnet having two or more magnetic poles on its inner or outer surface that are aligned in the circumferential direction (A2) of the ring magnet (50), The ring magnet (50) comprises a third magnet (53) arranged in a region including the magnetic poles of the inner or outer circumferential surface, and a fourth magnet (54) arranged in a region sandwiched between the two third magnets in the circumferential direction (A2). The third magnet (53) is a bonded magnet containing magnetic anisotropic magnetic powder, having magnetic poles on the radial (A3) circumferential surface and the circumferential (A2) end surface of the ring magnet (50). The fourth magnet (54) has a magnetic pole on its end face in the circumferential direction (A2), Rotor.

8. The rotor (40) is not provided with a yoke. The rotor according to claim 7.

9. The fourth magnet (54) is a bonded magnet made of the same material as the third magnet (53). The rotor according to claim 7.

10. The fourth magnet (54) is a bonded magnet containing magnetic anisotropic magnetic powder, In the fourth magnet (54), the orientation ratio in the circumferential direction (A2) near the end face is higher than the orientation ratio in the circumferential direction (A2) near the center of the circumferential direction (A2). The rotor according to claim 7.

11. A rotor (40) and a stator (30) as described in any one of claims 7 to 10, Motor.

12. The invention comprises a motor (20) as described in claim 11 and a blower (10) driven by the motor (20), Blower.

13. The motor (20) according to claim 11, Refrigeration equipment.

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