JP7442688B2 - Rotor, electric motor, blower and air conditioner - Google Patents

Description

The present disclosure relates to a rotor, a motor, a blower, and an air conditioner.

2. Description of the Related Art In a rotor used in an electric motor, a configuration is known in which a rotor body supported by a rotating shaft includes two types of bonded magnets with different magnetic properties. For example, see Patent Documents 1 to 3.

The rotor bodies described in Patent Documents 1 and 2 include a ferrite bond magnet as a first bond magnet and a rare earth bond magnet as a second bond magnet disposed outside the first bond magnet. The rare earth bonded magnets of Patent Documents 1 and 2 have an annular shape when viewed in the axial direction.

The rotor body described in Patent Document 3 includes a ferrite bond magnet and a plurality of rare earth bond magnets that are supported by the ferrite bond magnet and divided in the circumferential direction. Therefore, the cost of the rotor of Patent Document 3 is lower than that of the rotors of Patent Documents 1 and 2.

Japanese Patent Application Publication No. 2005-151757 Japanese Patent Application Publication No. 2011-87393 Japanese Patent Application Publication No. 2007-208104

However, in the rotor described in Patent Document 3, due to the difference between the linear expansion coefficient of the first bonded magnet and the linear expansion coefficient of the second bonded magnet, when a temperature change occurs, the first bonded magnet and the second bonded magnet There is a possibility that the second bonded magnet may peel off from the interface with the second bonded magnet. Further, there is also a risk that the second bonded magnet may be separated from the interface due to centrifugal force acting on the rotor body during rotation.

The present disclosure aims to prevent the second bonded magnet from peeling off.

A rotor according to one aspect of the present disclosure includes a rotating shaft and a rotor body supported by the rotating shaft, and the rotor body includes a first bonded magnet and a plurality of second bonded magnets. The first bonded magnet has a cylindrical magnet body and a first outer circumferential surface that is a radially outward surface of the magnet body and is long in the axial direction of the rotating shaft. a plurality of long grooves, each of the plurality of long grooves having a first groove portion that is long in the axial direction; a second groove that extends outward in the width direction of the first groove portion and is shallower than the first groove portion; The plurality of second bonded magnets are arranged so as to fill the plurality of long grooves.
A rotor according to another aspect of the present disclosure includes a rotation shaft and a rotor body supported by the rotation shaft, and the rotor body includes a first bond magnet and a plurality of second bond magnets. The first bonded magnet has a cylindrical magnet body and a first outer circumferential surface that is a radially outward surface of the magnet body and is long in the axial direction of the rotating shaft. It has a plurality of long grooves and a first stepped portion recessed from the first end in the axial direction toward one of the axial directions, and each of the plurality of long grooves has a first step portion that is long in the axial direction. and a second groove that extends outward in the width direction of the first groove and is shallower than the first groove, and the plurality of second bonded magnets fill in the plurality of long grooves. Each second bonded magnet of the plurality of second bonded magnets has a first protruding portion joined to the first stepped portion.

According to the present disclosure, peeling of the second bonded magnet can be prevented.

1 is a plan view showing the configuration of an electric motor according to Embodiment 1. FIG. 2 is a side view showing the configuration of the electric motor shown in FIG. 1. FIG. FIG. 2 is an enlarged plan view showing the configuration of the rotor shown in FIG. 1. FIG. FIG. 2 is a cross-sectional view showing the configuration of the rotor shown in FIG. 1. FIG. 4 is a plan view showing the configuration of the ferrite bond magnet shown in FIG. 3. FIG. (A) is a plan view showing the configuration of a rotor according to Comparative Example 1. (B) is a side view showing the configuration of a rotor according to Comparative Example 1. (A) is a plan view showing the configuration of a rotor according to Comparative Example 2. (B) is a side view showing the configuration of a rotor according to Comparative Example 2. 2 is a graph showing a distribution of surface magnetic flux density of a rotor according to Comparative Example 1 and a distribution of surface magnetic flux density of a rotor according to Comparative Example 2. 4 is an enlarged plan view showing a part of the configuration of the rotor shown in FIG. 3. FIG. 10 is an enlarged plan view showing the configuration around two adjacent rare earth bonded magnets shown in FIG. 9. FIG. 3 is a flowchart showing a manufacturing process of a rotor according to Embodiment 1. FIG. 5 is a flowchart showing a manufacturing process of a rotor main body of a rotor according to Embodiment 1. FIG. FIG. 3 is a plan view showing a part of the configuration of a rotor according to Embodiment 2. FIG. FIG. 7 is a cross-sectional view showing the configuration of a rotor according to Embodiment 3. FIG. 3 is a plan view showing the configuration of a rotor according to Embodiment 3; FIG. 7 is a plan view showing the configuration of a rotor according to Embodiment 4; FIG. 7 is a side view showing the configuration of a rotor according to Embodiment 4. 17 is a sectional view taken along the line A18-A18 of the rotor shown in FIG. 16. FIG. FIG. 7 is a plan view showing the configuration of a rotor according to a modification of Embodiment 4; 20 is a cross-sectional view of the rotor shown in FIG. 19 taken along line A20-A20. It is a figure which shows roughly the structure of the blower based on Embodiment 5. FIG. 7 is a diagram schematically showing the configuration of an air conditioner according to a sixth embodiment.

Below, a rotor, an electric motor, a blower, and an air conditioner according to embodiments of the present disclosure will be described with reference to the drawings. The following embodiments are merely examples, and the embodiments can be combined as appropriate and each embodiment can be changed as appropriate.

In order to make it easier to understand the relationship between the drawings, an xyz orthogonal coordinate system may be shown in each drawing. The z-axis is a coordinate axis parallel to the axis C of the rotor. The x-axis is a coordinate axis perpendicular to the z-axis. The y-axis is a coordinate axis perpendicular to both the x-axis and the z-axis.

《Embodiment 1》
FIG. 1 is a plan view showing the configuration of an electric motor 100 according to the first embodiment. FIG. 2 is a side view showing the configuration of electric motor 100 shown in FIG. 1. FIG. As shown in FIGS. 1 and 2, electric motor 100 includes a rotor 1 and a stator 9. As shown in FIGS. The rotor 1 is arranged inside the stator 9. That is, the electric motor 100 is an inner rotor type electric motor. An air gap G is formed between the rotor 1 and the stator 9. The air gap G is, for example, a gap of 0.5 mm. Electric motor 100 is, for example, a permanent magnet synchronous motor.

The rotor 1 has a shaft 10 as a rotation axis. The shaft 10 extends in the z-axis direction. In the following description, the z-axis direction will also be referred to as the "axial direction." Also, the direction along the circumference of a circle centered on the axis C of the shaft 10 (for example, the circumferential direction R indicated by the arrow in FIG. 1) is the "circumferential direction", and the direction passing through the axis C perpendicular to the z-axis direction is referred to as the "circumferential direction". The direction of the straight line is called the "radial direction."

<stator>
Stator 9 includes a stator core 91 and a coil 92 wound around stator core 91. Stator core 91 has an annular yoke 91a centered on axis C, and a plurality of teeth 91b extending radially inward from yoke 91a. The plurality of teeth 91b are arranged at equal angular intervals in the circumferential direction R. The teeth 91b face the outer circumferential surface 1a of the rotor 1 with an air gap G interposed therebetween. In the example shown in FIG. 1, the number of teeth 91b is twelve. Note that the number of teeth 91b is not limited to 12, and may be set to any number.

<Rotor>
Below, details of the configuration of the rotor 1 will be explained. FIG. 3 is an enlarged plan view showing the configuration of the rotor 1 shown in FIG. 1. FIG. FIG. 4 is a sectional view showing the configuration of the rotor 1 shown in FIG. 1. As shown in FIG. As shown in FIGS. 2 to 4, the rotor 1 has a rotor body 50 supported by a shaft 10. As shown in FIGS. The rotor main body 50 includes a ferrite bond magnet 20 as a first bond magnet and a plurality of rare earth bond magnets 31 as a plurality of second bond magnets.

As shown in FIG. 2, in the first embodiment, the length L 1 of the rotor main body 50 of the rotor ₁ in the z-axis direction is equal to the length L 9 of the stator core 91 of the stator ₉ in the z-axis direction. longer. Thereby, the amount of magnetic flux linkage flowing from the bonded magnets of the rotor body 50 (that is, the ferrite bonded magnets 20 and the rare earth bonded magnets 31) to the coils 92 of the stator 9 can be increased.

Ferrite bond magnet 20 is supported by shaft 10. Ferrite bond magnet 20 includes a ferrite magnet and resin. Examples of the resin contained in the ferrite bond magnet 20 include nylon resin, PPS (Poly Phenylene Sulfide) resin, and epoxy resin.

The plurality of rare earth bonded magnets 31 are supported by the ferrite bonded magnet 20. Rare earth bonded magnet 31 includes a rare earth magnet and resin. The rare earth magnet is, for example, a neodymium magnet containing neodymium (Nd), iron (Fe), and boron (B), or a samarium iron nitrogen magnet containing samarium (Sm), Fe, and nitrogen (N). The resin contained in the rare earth bonded magnet 31 is, like the resin contained in the ferrite bonded magnet 20, for example, nylon resin, PPS resin, or epoxy resin.

The magnetic pole strength (that is, the amount of magnetism) of the rare earth bonded magnet 31 is different from the magnetic pole strength of the ferrite bonded magnet 20 . Specifically, the rare earth bonded magnet 31 has a magnetic pole stronger than the magnetic pole of the ferrite bonded magnet 20. In other words, the magnetic force of the rare earth bonded magnet 31 is greater than the magnetic force of the ferrite bonded magnet 20. Further, the linear expansion coefficient of the rare earth bonded magnet 31 is different from that of the ferrite bonded magnet 20.

As shown in FIG. 3, the ferrite bond magnet 20 is supported by the shaft 10 with a resin part 60 interposed therebetween. The resin portion 60 is made of, for example, unsaturated polyester resin.

The resin part 60 has an inner cylinder part 61, an outer cylinder part 62, and a plurality of (four in the first embodiment) ribs 63. The inner cylinder portion 61 has a cylindrical shape and is fixed to the outer circumferential surface 10a of the shaft 10. The outer cylinder portion 62 has a cylindrical shape and is fixed to the inner peripheral surface of the ferrite bonded magnet 20. The plurality of ribs 63 connect the inner cylinder part 61 and the outer cylinder part 62. The plurality of ribs 63 extend radially outward from the outer periphery of the inner cylinder portion 61 in the radial direction. The plurality of ribs 63 are arranged at equiangular positions in the circumferential direction R. Note that the ferrite bond magnet 20 may be directly fixed to the shaft 10 without intervening the resin part 60.

FIG. 5 is a plan view showing the configuration of the ferrite bonded magnet 20 shown in FIG. 3. As shown in FIG. 5, the planar shape of the ferrite bonded magnet 20 parallel to the xy plane is annular with axis C as the center. The outer peripheral surface of the ferrite bonded magnet 20 forms a part of the outer peripheral surface 1a (see FIG. 1) of the rotor 1.

The ferrite bond magnet 20 has a cylindrical magnet body 21 and a plurality of long grooves 23 that are long in the z-axis direction. The plurality of long grooves 23 are provided on an outer circumferential surface 22a serving as a first outer circumferential surface, which is a radially outward surface of the magnet body 21.

The plurality of long grooves 23 are arranged at intervals in the circumferential direction R. In the example shown in FIG. 5, the plurality of long grooves 23 are arranged at equiangular positions in the circumferential direction R. Since the ferrite bonded magnet 20 has a plurality of convex portions 22 that protrude radially outward from the outer peripheral surface of the magnet body 21, a plurality of long grooves 23 are formed. A plurality of rare earth bonded magnets 31 are arranged within the plurality of long grooves 23, respectively.

Ferrite bonded magnet 20 is oriented to have polar anisotropy. As a result, the plurality of long grooves 23 have a south pole long groove 231 and a north pole long groove 232. That is, the plurality of long grooves 231 and 232 adjacent to each other in the circumferential direction R have magnetic poles with mutually different polarities. An arcuate arrow F2 shown in FIG. 5 indicates the direction of magnetic flux in the ferrite bond magnet 20. The magnetic flux flowing from the outside of the S-pole long groove 231 in the radial direction advances to the N-pole long groove 232 adjacent in the circumferential direction R. Therefore, the rotor 1 (see FIG. 2) does not require a rotor core that forms a magnetic path inside the ferrite bond magnets 20 in the radial direction. Thereby, the number of parts in the rotor 1 can be reduced, and the weight of the rotor 1 can be reduced.

As shown in FIG. 3, the plurality of rare earth bonded magnets 31 are arranged at intervals in the circumferential direction R. The outer circumferential surface (that is, the outer circumferential surface 31a shown in FIG. 9, which will be described later) of each of the plurality of rare earth bonded magnets 31 is one of the outer circumferential surfaces 1a of the rotor 1 (see FIG. 1). It forms a part. The outer circumferential surface and inner circumferential surface of the rare earth bonded magnet 31 are located concentrically. Therefore, the radial thickness of the rare earth bonded magnet 31 is constant in the circumferential direction R.

Each of the plurality of rare earth bonded magnets 31 is oriented to have polar anisotropy. A plurality of rare earth bonded magnets 31 adjacent in the circumferential direction R have magnetic poles with mutually different polarities. An arcuate arrow F1 shown in FIG. 3 indicates the direction of magnetic flux in the rare earth bonded magnet 31. Magnetic flux flowing from the outside of the S-pole rare earth bonded magnet 31 in the radial direction advances to the N-pole rare earth bonded magnet 31 adjacent in the circumferential direction R. In the first embodiment, since the rare earth bonded magnets 31 have eight rare earth bonded magnets 31, the rotor 1 has eight magnetic poles. Note that the number of poles of the rotor 1 is not limited to eight, but may be 2n or more. Here, n is an integer of 1 or more.

The rare earth bonded magnet 31 is joined to the ferrite bonded magnet 20. In the first embodiment, the ferrite bonded magnet 20 and the rare earth bonded magnet 31 are integrally molded (also referred to as "two-color molding"), so that the rare earth bonded magnet 31 is arranged so as to fill the inside of the long groove 23. In the first embodiment, the rare earth bonded magnet 31 is joined to the long groove 23 of the ferrite bonded magnet 20.

In the following description, when the ferrite bond magnet 20 and the rare earth bond magnet 31 are integrally molded, it means that the rare earth bond magnet 31 is molded with the previously manufactured ferrite bond magnet 20 placed in a mold. As a result, compared to the manufacturing process in which the ferrite bonded magnet 20 is molded with a plurality of pre-manufactured rare earth bonded magnets 31 arranged in a mold, in the first embodiment, the plurality of rare earth bonded magnets 31 are molded one by one. The work of placing it in the mold becomes unnecessary. Therefore, productivity of the rotor main body 50 can be improved.

Next, the cost of the rotor 1 according to the first embodiment will be explained in comparison with the rotor 101a according to the first comparative example. FIG. 6(A) is a plan view showing the configuration of the rotor 101a according to Comparative Example 1. FIG. 6(B) is a side view showing the configuration of the rotor 101a according to Comparative Example 1. Note that illustration of the shaft 10 is omitted in FIGS. 6(A) and 6(B).

As shown in FIGS. 6A and 6B, in the rotor 101a, an annular rare earth bonded magnet 130a is arranged on an outer peripheral surface 120c of an annular ferrite bonded magnet 120a. That is, in the rotor 101a, the entire outer peripheral surface 101c of the rotor 101a is formed of the rare earth bonded magnet 130a.

On the other hand, as shown in FIG. 2 described above, in the first embodiment, the outer circumferential surface 1a of the rotor 1 is formed by the outer circumferential surface of the ferrite bonded magnet 20 and the outer circumferential surface of each of the plurality of rare earth bonded magnets 31. has been done. Thereby, in the rotor 1, the amount of rare earth bonded magnets 31 used can be reduced compared to the rotor 101a. Specifically, in the rotor 1, the amount of rare earth bonded magnets 31 used can be reduced by about 20% compared to the rotor 101a.

Furthermore, the rare earth bonded magnet 31 is more expensive than the ferrite bonded magnet 20. For example, the material unit price of the rare earth bonded magnet 31 is ten times or more the material unit price of the ferrite bonded magnet 20. Therefore, since the outer circumferential surface 1a of the rotor 1 is formed by the outer circumferential surface of the ferrite bonded magnet 20 and the outer circumferential surface of each of the plurality of rare earth bonded magnets 31, the amount of rare earth bonded magnets 31 used can be reduced. can. Therefore, the cost of the rotor 1 can be reduced.

Next, the surface magnetic flux density of the rotor 1 according to Embodiment 1 will be described in comparison with the rotor 101a according to Comparative Example 1 and the rotor 101b according to Comparative Example 2. FIG. 7(A) is a plan view showing the configuration of the rotor 101b according to Comparative Example 2. FIG. 7(B) is a side view showing the configuration of the rotor 101b according to Comparative Example 2. Note that illustration of the shaft 10 is omitted in FIGS. 7(A) and 7(B).

As shown in FIGS. 7A and 7B, the rotor 101b includes a ferrite bond magnet 120b and a plurality of rare earth bond magnets 131b. The plurality of rare earth bonded magnets 131b are arranged at intervals in the circumferential direction R. Therefore, the usage amount of the rare earth bonded magnet 131b of the rotor 101b is different from the usage amount of the rare earth bonded magnet 130a of the rotor 101a.

FIG. 8 is a graph showing the distribution of surface magnetic flux density of rotor 101a according to Comparative Example 1 and the distribution of surface magnetic flux density of rotor 101b according to Comparative Example 2. In FIG. 8, the horizontal axis indicates the position [degrees] in the circumferential direction R on the outer circumferential surface 101c of the rotor 101a or the outer circumferential surface 101d of the rotor 101b, and the vertical axis indicates the surface magnetic flux density [a. u. ]. Moreover, in FIG. 8, the broken line shows the distribution of surface magnetic flux density of rotor 101a according to Comparative Example 1, and the solid line shows the distribution of surface magnetic flux density of rotor 101b according to Comparative Example 2.

As shown in FIG. 8, the surface magnetic flux density distribution of the rotor 101a is represented by a uniform sinusoidal waveform S1. On the other hand, the distribution of the surface magnetic flux density of the rotor 101b is also represented by a substantially uniform, substantially sinusoidal waveform S2. That is, compared to the rotor 101a, the rotor 101b has a suppressed sudden change in surface magnetic flux density in the circumferential direction R.

As described above, the rotor 1 according to the first embodiment also has a plurality of rare earth bonded magnets 31 arranged at intervals in the circumferential direction R, similarly to the rotor 101b, so that the surface magnetic flux of the rotor 1 is The density distribution is also represented by a generally uniform sinusoidal waveform (not shown).

Here, in the manufacturing process of the rotor 101b according to Comparative Example 2, the rare earth bonded magnet 131b is molded with the previously manufactured ferrite bonded magnet 120b placed in a mold. At this time, the resin contained in the raw material of the rare earth bonded magnet 131b flows into the minute gap between the outer peripheral surface of the ferrite bonded magnet 120b and the mold, so that a thin resin ( (hereinafter also referred to as "burrs") may be formed. If the burr falls off the outer circumferential surface of the ferrite bonded magnet 120b due to the centrifugal force acting during rotation, there is a risk that the reliability of the electric motor having the rotor 101b may decrease. Furthermore, since the linear expansion coefficient of the rare earth bonded magnet 131b is different from that of the ferrite bonded magnet 120b, there is a risk that burr cracks may occur due to temperature changes. If the burr breaks, there is a risk that the burr will peel off during rotation.

Below, a configuration for preventing peeling of the rare earth bonded magnets 31 in the rotor 1 according to the first embodiment will be described using FIGS. 9 and 10. FIG. 9 is an enlarged plan view showing a part of the configuration of the rotor 1 shown in FIG. 3. FIG. FIG. 10 is an enlarged plan view showing the configuration around two adjacent rare earth bonded magnets 31 shown in FIG. As shown in FIGS. 9 and 10, the long groove 23 of the ferrite bonded magnet 20 has a first groove 41 that is long in the z-axis direction, and extends outward in the width direction of the first groove 41, and is wider than the first groove 41. It has a shallow second groove portion 42.

The first groove portion 41 is, for example, approximately U-shaped in plan view. The first groove portion 41 has a first surface 23a and a second surface 23b. The first surface 23a is the radially outward bottom surface of the ferrite bonded magnet 20. The second surface 23b is a side surface that is connected to the first surface 23a and faces each other. The second surface 23b extends radially outward from both ends of the first surface 23a in the width direction.

The second groove 42 has a third surface 23c that is the bottom surface of the second groove 42. The third surface 23c is connected to the second end 23d of the second surface 23b on the outer peripheral surface 22a side. The third surface 23c extends in the width direction of the long groove 23 from the second end 23d on the radially outer side of the second surface 23b so that the width of the long groove 23 increases.

The third surface 23c extends from both ends of the outer circumferential surface 22a of the ferrite bonded magnet 20 in the circumferential direction R toward the polar center P of the rare earth bonded magnet 31, and is inclined inward in the radial direction as it approaches the polar center P. . As a result, the ferrite bonded magnet 20 has a substantially petal-shaped shape when viewed from above. Note that the third surface 23c may extend from both ends of the outer circumferential surface 22a toward the polar center P while being curved.

The plurality of rare earth bonded magnets 31 are arranged so as to fill the insides of the plurality of long grooves 23. In other words, the rare earth bonded magnet 31 is bonded to the first surface 23a, the second surface 23b, and the third surface 23c so as to be in close contact with each other. As a result, compared to the rare earth bonded magnet 131b of the rotor 101b according to Comparative Example 2 shown in FIGS. 7(A) and 7(B), the rare earth bonded magnet 31 has a portion joined to the third surface 23c. are doing. The thickness of the portion of the rare earth bonded magnet 31 that is bonded to the third surface 23c is thicker than the thickness of the burr described above. Therefore, the bonding strength of the rare earth bonded magnet 31 to the ferrite bonded magnet 20 is improved. Therefore, it is possible to prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Further, it is possible to prevent the rare earth bonded magnet 31 from peeling off due to temperature changes.

Further, in the first embodiment, the second groove portion 42 becomes shallower as the distance from the first groove portion 41 increases. Thereby, the thickness of the portion of the rare earth bonded magnet 31 that is bonded to the third surface 23c can be reduced while ensuring the bonding strength, so that the amount of the rare earth bonded magnet 31 used can be reduced. Therefore, it is possible to prevent the rare earth bonded magnets 31 from peeling off while reducing the cost of the rotor 1.

Further, in the first embodiment, the distance between the second surfaces 23b that face each other becomes narrower as the distance from the first surface 23a increases. Thereby, the usage amount of the portion of the rare earth bonded magnet 31 that is bonded to the first surface 23a and the second surface 23b can be reduced. Therefore, the cost of the rotor 1 can be reduced. Note that the second surfaces 23b facing each other may extend parallel to the radial direction.

Further, in the first embodiment, the outer circumferential surface 22a of the ferrite bonded magnet 20 as the first outer circumferential surface and the outer circumferential surface 31a of the rare earth bonded magnet 31 as the second outer circumferential surface are formed flush with each other. Thereby, the amount of rare earth bonded magnet 31 used can be reduced. Therefore, the cost of the rotor 1 can be reduced.

Further, as shown in FIG. 10, two second surfaces 23b disposed across the outer circumferential surface 22a of two adjacent long grooves 23 of the plurality of long grooves 23 are ends close to the shaft 10. It has a first end 23e and a second end 23d which is an end far from the shaft 10. Here, the first angle that is the central angle between the two surfaces B1 and B2 connecting the axis C and the first end 23e of the shaft 10 is θ ₁ , and the axis C and the second end 23 d are When the second angle, which is the central angle between the two connecting surfaces B3 and B4, is θ ₂ , the first angle θ ₁ is smaller than the second angle θ ₂ . That is, the first angle θ ₁ and the second angle θ ₂ satisfy the following equation (1).
θ ₁ <θ ₂ (1)

When the first angle θ ₁ and the second angle θ ₂ satisfy formula (1), that is, the two second surfaces 23b facing each other have a shape that satisfies formula (1), so that the long groove 23 The width becomes narrower from the outside to the inside in the radial direction. In other words, the long groove 23 in the first embodiment is a dovetail groove. By arranging the rare earth bonded magnet 31 within the long groove 23, the bonding area of the rare earth bonded magnet 31 to the long groove 23 increases. Therefore, it is possible to further prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

As shown in FIG. 10, when the length in the width direction of the third surface 23c is W ₁ and the length in the width direction of the outer peripheral surface 22a is W ₂ , the length W ₁ is shorter than the length W ₂ . This makes it possible to reduce the amount of rare earth bonded magnet 31 to be bonded to third surface 23c while ensuring bonding strength. Therefore, it is possible to prevent the rare earth bonded magnets 31 from peeling off while reducing the cost of the rotor 1.

Next, a method for manufacturing the rotor 1 will be described using FIG. 11. FIG. 11 is a flowchart showing the manufacturing process of the rotor 1. In the manufacturing process of the rotor 1, a magnetizer is used.

In step ST1, the rotor body 50 is formed. Note that details of step ST1 will be described later.

In step ST2, the rotor main body 50 is connected to the shaft 10. In the first embodiment, the rotor body 50 and the shaft 10 are integrated through the resin portion 60, so that the rotor body 50 is connected to the shaft 10.

In step ST3, the rotor main body 50 is magnetized using, for example, a magnetizer. Specifically, the ferrite bond magnet 20 and the rare earth bond magnet 31 are magnetized so that the ferrite bond magnet 20 and the rare earth bond magnet 31 have polar anisotropy.

Next, details of the step of forming the rotor body 50 (that is, step ST1 shown in FIG. 11) will be described using FIG. 12. FIG. 12 is a flowchart showing the process of forming the rotor body 50. In the step of forming the rotor body 50, a first mold for molding the ferrite bond magnet 20, a second mold for molding the rare earth bond magnet 31, and an orientation magnet are used. .

In step ST11, a first mold for molding the ferrite bonded magnet 20 is filled with a raw material for the ferrite bonded magnet 20. The ferrite bonded magnet 20 is molded, for example, by injection molding. Note that the ferrite bond magnet 20 is not limited to injection molding, and may be molded by other molding methods such as press molding.

In step ST12, the ferrite bonded magnet 20 is formed into a predetermined shape while orienting the ferrite bonded magnet 20. In step ST12, for example, the raw material of the ferrite bond magnet 20 is oriented while a magnetic field having polar anisotropy is generated inside the first mold using an orientation magnet. 20 is formed. As a result, a ferrite bonded magnet 20 having polar anisotropy is formed.

In step ST13, the molded ferrite bond magnet 20 is cooled.

In step ST14, the ferrite bonded magnet 20 is taken out from the first mold.

In step ST15, the taken out ferrite bond magnet 20 is demagnetized.

In step ST16, the ferrite bond magnet 20 is placed inside a second mold for injection molding the rare earth bond magnet 31.

In step ST17, the long grooves 23 of the ferrite bonded magnet 20 placed in the second mold are filled with raw material for the rare earth bonded magnet 31. The rare earth bonded magnet 31 is formed by injection molding, for example. Note that the rare earth bonded magnet 31 may be molded not only by injection molding but also by other molding methods such as press molding.

In step ST18, the rare earth bonded magnet 31 having a predetermined shape is formed while orienting the raw material of the rare earth bonded magnet 31. In step ST18, for example, the raw material of the rare earth bonded magnet 31 is oriented while a magnetic field having polar anisotropy is generated inside the second mold using an orientation magnet. 31 is molded. As a result, a rotor body 50 is formed in which the ferrite bond magnet 20 and the plurality of rare earth bond magnets 31 are integrally molded.

In step ST19, the rotor body 50 formed in step ST18 is cooled.

In step ST20, the cooled rotor body 50 is taken out from the second mold.

In step ST21, the rotor body 50 taken out in step ST20 is demagnetized.

<Effects of Embodiment 1>
As described above, according to the first embodiment, each long groove 23 of the plurality of long grooves 23 of the ferrite bonded magnet 20 has a first groove 41 long in the z-axis direction and a width direction of the first groove 41. It has a second groove portion 42 that extends outward from the groove portion 41 and is shallower than the first groove portion 41 . The plurality of rare earth bonded magnets 31 are arranged so as to fill the insides of the plurality of long grooves 23. This improves the bonding strength of the rare earth bonded magnet 31 to the ferrite bonded magnet 20. Therefore, it is possible to prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Further, it is possible to prevent the rare earth bonded magnet 31 from peeling off due to temperature changes.

Further, according to the first embodiment, the second groove 42 has a third groove connected to the second end 23d on the outer peripheral surface 22a side of the second surface 23b, which is the side surface of the first groove 41. The third surface 23c becomes shallower as the distance from the first groove 41 increases. Thereby, the thickness of the portion of the rare earth bonded magnet 31 that is joined to the third surface 23c becomes thinner as the distance from the first groove portion 41 increases, so that the amount of the rare earth bonded magnet 31 used can be reduced. Therefore, according to the first embodiment, it is possible to prevent the rare earth bonded magnets 31 from peeling off and falling off while reducing the cost of the rotor 1.

Further, according to the first embodiment, the distance between the second surfaces 23b that face each other becomes narrower as the distance from the first surface 23a increases. This reduces the amount of use of the portion of the rare earth bonded magnet 31 that is joined to the first surface 23a and the second surface 23b, compared to a configuration in which the second surface 23b extends parallel to the radial direction. can do. Therefore, the cost of the rotor 1 can be reduced. Furthermore, the width of the long groove 23 becomes narrower as it goes from the outside to the inside in the radial direction, and the bonding strength of the rare earth bonded magnet 31 to the long groove 23 is improved by arranging the rare earth bonded magnet 31 within the long groove 23. Therefore, it is possible to further prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

Further, according to the first embodiment, the first angle θ ₁ described above is smaller than the second angle θ ₂ . Thereby, the width of the long groove 23 becomes narrower as it goes from the outer side to the inner side in the radial direction. Therefore, by arranging the rare earth bonded magnet 31 within the long groove 23, the bonding strength of the rare earth bonded magnet 31 to the long groove 23 is improved. Therefore, it is possible to further prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

Further, according to the first embodiment, the outer peripheral surface 22a of the ferrite bonded magnet 20 and the outer peripheral surface 31a of the rare earth bonded magnet 31 are formed flush with each other. Thereby, the amount of rare earth bonded magnet 31 used can be reduced. Therefore, the cost of the rotor 1 can be reduced.

Further, according to the first embodiment, the widthwise length _W1 of the third surface 23c is shorter than the widthwise length _W2 of the outer circumferential surface 22a. This makes it possible to reduce the amount of rare earth bonded magnet 31 to be bonded to third surface 23c while ensuring bonding strength. Therefore, it is possible to prevent the rare earth bonded magnets 31 from peeling off and falling off while reducing the cost of the rotor 1.

Further, according to the first embodiment, electric motor 100 includes rotor 1 and stator 9. As described above, in the rotor 1, the rare earth bonded magnets 31 are prevented from falling off due to centrifugal force acting during rotation. Since the electric motor 100 includes the rotor 1, the reliability of the electric motor 100 can be improved.

《Embodiment 2》
FIG. 13 is a plan view showing a part of the configuration of the rotor 2 according to the second embodiment. In FIG. 13, components that are the same as or correspond to those shown in FIGS. 9 and 10 are given the same reference numerals as those shown in FIGS. 9 and 10. The rotor 2 according to the second embodiment differs from the rotor 1 according to the first embodiment in the shape of the ferrite bond magnet 220. In other respects, the rotor 2 according to the second embodiment is the same as the rotor 1 according to the first embodiment. Therefore, in the following description, reference is made to FIGS. 9 and 10.

As shown in FIG. 13, the rotor body of the rotor 2 includes a ferrite bond magnet 220 and a plurality of rare earth bond magnets 31. The ferrite bonded magnet 220 has a cylindrical magnet body 221 and a plurality of long grooves 223 that are provided on the outer peripheral surface 222a of the magnet body 221 and are long in the z-axis direction. Each long groove 223 of the plurality of long grooves 223 has a first groove portion 41 that is long in the z-axis direction, and a second groove portion 42 that extends outward in the width direction of the first groove portion 41 and is shallower than the first groove portion 41. .

The first groove portion 41 has a second surface 223b that is a side surface. The second surface 223b is connected to the radially outward bottom surface of the first groove portion 41. The second groove portion 42 has a third surface 223c that is a bottom surface. The third surface 223c is connected to the end of the second surface 223b on the outer peripheral surface 222a side.

Here, the rotor 2 has a number of poles of 2n (n is an integer of 1 or more). Also, the inner side in the radial direction of the angle formed by the surface B3 connecting the end of the second surface 223b on the outer circumferential surface 222a side and the axis C of the shaft 10 and the surface B5, which is a plane including the second surface 223b. When the third angle, which is the angle of , is θ ₃ , the third angle θ ₃ satisfies the following equation (2).
θ ₃ > (360°/(2・2n)) - (θ ₂ /2) (2)
Thereby, the width of the long groove 223 tends to become narrower as it goes from the outer side to the inner side in the radial direction. In other words, the long groove 223 tends to become a dovetail groove. Therefore, by arranging the rare earth bonded magnet 31 to fill the inside of the long groove 223, the bonding area of the rare earth bonded magnet 31 to the long groove 223 increases. Therefore, it is possible to further prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

Here, the derivation of the above equation (2) will be explained. When the surface B5 shown in FIG. 13 extends parallel to the straight line connecting the polar center (for example, the polar center P shown in FIG. 9) and the axis C or extends toward the outer circumference, the long groove 223 does not become a dovetail groove. Therefore, the rare earth bonded magnet 31 is likely to fall off due to the centrifugal force that acts during rotation. When a straight line parallel to the straight line connecting the polar center and the axis C is B6, the angle between the plane B3 and the straight line B6 is θ ₄ , and the angle between the polar center and the part between the poles is θ ₅ , the angle θ ₄ satisfies the following equation (3), and the angle θ ₅ satisfies the following equation (4). Note that n in formula (4) is an integer of 1 or more.
θ ₄ = θ ₅ - (θ ₂ /2) (3)
θ ₅ =360°/(2・2n) (4)

The following equation (5) is derived from equations (3) and (4).
θ ₄ = (360°/(2・2n))−(θ ₂ /2) (5)
When the angle θ ₄ satisfies equation (5), the long groove 223 does not become a dovetail groove. In other words, in order for the long groove 223 to become a dovetail groove, the angle θ ₄ needs to be larger than the value on the right side of equation (5). Therefore, the above equation (2) regarding the third angle θ ₃ formed by the plane B3 and the straight line B6 is derived.

<Effects of Embodiment 2>
As described above, according to the second embodiment, the surface B3 connecting the radially outer end of the second surface 223b of the long groove 223 and the axis C of the shaft 10 and the second surface 223b are connected to each other. The third angle θ ₃ , which is the inner angle in the radial direction among the angles formed by the included surface B5, satisfies the above-mentioned formula (2). Thereby, the width of the long groove 223 tends to become narrower as it goes from the outer side to the inner side in the radial direction. Therefore, by arranging the rare earth bonded magnet 31 within the long groove 223, the bonding area of the rare earth bonded magnet 31 to the long groove 223 increases. Therefore, it is possible to further prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

《Embodiment 3》
FIG. 14 is a sectional view showing the configuration of the rotor 3 according to the third embodiment. FIG. 15 is a plan view showing the configuration of the rotor 3 according to the third embodiment. In FIGS. 14 and 15, components that are the same as or correspond to those shown in FIGS. 3 and 4 are given the same reference numerals as those shown in FIGS. 3 and 4. The rotor 3 according to the third embodiment is different from the rotors 1 and 2 according to either the first or second embodiment in the shape of the ferrite bond magnet 320 and the shape of the rare earth bond magnet 331. In other respects, the rotor 3 according to the third embodiment is the same as the rotors 1 and 2 according to either the first or second embodiment.

As shown in FIGS. 14 and 15, the rotor body of the rotor 3 includes a ferrite bond magnet 320 and a plurality of rare earth bond magnets 331.

As shown in FIG. 14, the ferrite bond magnet 320 has a first step portion 322p and a second step portion 322g. The first stepped portion 322p is formed at an end 320c on the +z-axis side as a third end, which is one end of the ferrite bonded magnet 320 in the z-axis direction. The second stepped portion 322g is formed at the −z-axis side end 320d, which is the fourth end. The first step portion 322p is recessed in the −z-axis direction from the +z-axis end portion 320c. The second step portion 322g is recessed in the +z-axis direction from the −z-axis side end portion 320d. Note that the ferrite bonded magnet 320 may have only one of the first step portion 322p and the second step portion 322g.

As shown in FIG. 15, the rare earth bonded magnet 331 has a column portion 351, a first overhang portion 353, and a second overhang portion 354. The column portion 351 is a portion of the rare earth bonded magnet 331 that is filled into the long groove 23 (see, for example, FIG. 9). The length of the columnar portion 351 in the z-axis direction is equal to the length of the ferrite bonded magnet 20 in the z-axis direction. Thereby, the amount of rare earth bonded magnets 331 used can be reduced, so the cost of the rotor 3 can be reduced.

The first overhanging portion 353 and the second overhanging portion 354 extend radially inward from the inner circumferential surface 351b of the columnar portion 351. The first projecting portion 353 is joined to the bottom surface of the first stepped portion 322p. The second projecting portion 354 is joined to the bottom surface of the second stepped portion 322g. Thereby, the bonding area between the rare earth bonded magnet 331 and the ferrite bonded magnet 320 can be further increased. Therefore, it is possible to further prevent the rare earth bonded magnet 331 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 331 due to temperature changes can be further prevented.

The shape of the first projecting portion 353 when viewed in the −z-axis direction is, for example, approximately triangular. Although not shown, the shape of the second projecting portion 354 when viewed in the +z-axis direction is also approximately triangular, for example. Note that the shape of each of the first projecting portion 353 and the second projecting portion 354 is not limited to a substantially triangular shape, but may be other shapes.

<Effects of Embodiment 3>
According to the third embodiment described above, the first projecting portion 353 of the rare earth bonded magnet 331 is joined to the first stepped portion 322p formed on the ferrite bonded magnet 322. Thereby, the bonding area between the rare earth bonded magnet 331 and the ferrite bonded magnet 320 can be further increased. Therefore, it is possible to further prevent the rare earth bonded magnet 331 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 331 due to temperature changes can be further prevented.

Further, according to the third embodiment, the second protruding portion 354 of the rare earth bonded magnet 331 is joined to the second stepped portion 322g formed on the ferrite bonded magnet 322. Thereby, the bonding area between the rare earth bonded magnet 331 and the ferrite bonded magnet 320 can be increased. Therefore, it is possible to further prevent the rare earth bonded magnet 331 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 331 due to temperature changes can be further prevented.

《Embodiment 4》
FIG. 16 is a plan view showing the configuration of the rotor 4 according to the fourth embodiment. FIG. 17 is a side view showing the configuration of the rotor 4 according to the fourth embodiment. FIG. 18 is a cross-sectional view of the rotor 4 shown in FIG. 16 taken along line A18-A18. In FIGS. 16-18, components that are the same as or correspond to those shown in FIGS. 1-3 are given the same reference numerals as those shown in FIGS. 1-3. The rotor 4 according to the fourth embodiment is different from the rotors 1 to 3 according to any one of the first to third embodiments in that it further includes ring members 81 and 82. Note that in FIGS. 16 to 18, illustration of the shaft 10 and the resin portion 60 (see FIG. 3) is omitted.

As shown in FIGS. 16 to 18, the rotor 4 includes a ferrite bond magnet 20, a plurality of rare earth bond magnets 31, and a plurality of ring members 81 and 82 as a plurality of first resin parts.

The ring members 81 and 82 are each annular members centered on the axis C. The ring members 81 and 82 are made of resin such as unsaturated polyester resin, for example.

The ring member 81 is arranged to cover the +z-axis side end surface 20j of the ferrite bond magnet 20 and the +z-axis side end surface 31j of the rare earth bonded magnet 31. Thereby, the end surface 31j of the rare earth bonded magnet 31 is connected to the end surface 20k of the ferrite bonded magnet 20 via the ring member 81. Therefore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

In the fourth embodiment, the ring member 81 is fixed to the ferrite bond magnet 20 and the rare earth bond magnet 31. Specifically, the ring member 81 is fixed to the end face 20j of the ferrite bond magnet 20 on the +z axis side and the end face 31j of the rare earth bond magnet 31 on the +z axis side.

The ring member 82 is arranged to cover the -z-axis end surface 20g of the ferrite bond magnet 20 and the -z-axis end surface 31g of the rare earth bond magnet 31. As a result, the end surface 31g of the rare earth bonded magnet 31 is connected to the −z-axis end surface 20g of the ferrite bonded magnet 20 via the ring member 82. Thereby, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

In the fourth embodiment, the ring member 82 is fixed to the ferrite bond magnet 20 and the rare earth bond magnet 31. Specifically, the ring member 82 is fixed to the end face 20k of the ferrite bond magnet 20 facing the -z axis direction and the end face 31k of the rare earth bond magnet 31 facing the -z axis direction. Note that the rotor 4 can be realized without having one of the plurality of ring members 81 and 82.

<Effects of Embodiment 4>
According to the fourth embodiment described above, the rotor 4 includes ring members 81 and 82 arranged to cover the end faces of the ferrite bond magnet 20 and the rare earth bond magnet 31 in the z-axis direction, respectively. Thereby, the rare earth bonded magnet 31 is connected to the ferrite bonded magnet 20 via the ring members 81 and 82. Therefore, it is possible to further prevent the rare earth bonded magnet 31 from falling off due to centrifugal force acting during rotation. Furthermore, peeling of the rare earth bonded magnet 31 due to temperature changes can be further prevented.

《Modification of Embodiment 4》
FIG. 19 is a plan view showing the configuration of a rotor 4A according to a modification of the fourth embodiment. FIG. 20 is a cross-sectional view of the rotor 4A shown in FIG. 19 taken along line A20-A20. A rotor 4A according to a modification of the fourth embodiment differs from the rotor 4 according to the fourth embodiment in that ring members 81A and 82A are integrally formed with a resin portion 60A.

As shown in FIGS. 19 and 20, the rotor 4A includes a shaft 10, a ferrite bond magnet 20, a plurality of rare earth bond magnets 31, ring members 81A and 82A as a first resin part, and a second resin part. It has a resin part 60A as a resin part.

The resin part 60A includes an inner cylinder part 61 supported by the shaft 10, an outer cylinder part 62A fixed to the inner circumferential surface 20b of the ferrite bonded magnet 20, and a plurality of resin parts connecting the inner cylinder part 61 and the outer cylinder part 62A. It has a rib 63A.

The resin portion 60A is formed integrally with the ring members 81A and 82A. In other words, the resin portion 60A is connected to the ring members 81A and 82A. In a modification of the fourth embodiment, an outer cylinder portion 62A and a rib 63A of the resin portion 60A are connected to ring members 81A and 82A. Therefore, in the modification of the fourth embodiment, the shaft 10, the ferrite bond magnet 20, and the rare earth bond magnet 31 are connected via the resin portion 60A and the ring members 81A and 82A. Thereby, when the shaft 10 and the ferrite bond magnet 20 are integrally molded via the resin portion 60A, the ring members 81A and 82A can also be molded at the same time. Therefore, the manufacturing process of the rotor 4A can be simplified.

<Effects of modification of Embodiment 4>
According to the modification of the fourth embodiment described above, in the rotor 4A, the resin portion 60A is formed integrally with the ring members 81A and 82A. Thereby, when the shaft 10 and the ferrite bond magnet 20 are integrally molded via the resin portion 60A, the ring members 81A and 82A can also be molded at the same time. Therefore, the manufacturing process of the rotor 4A can be simplified.

Here, the natural frequency of the rotor 4A changes depending on the rigidity of the rotor 4A. The rigidity of the rotor 4A can be adjusted, for example, by changing the width in the circumferential direction R, the length in the radial direction, and the number of ribs 63A in the resin portion 60A. In the modification of the fourth embodiment, the resin portion 60A is formed integrally with the ring members 81A, 82A, so that the ribs 63A of the resin portion 60A are connected to the ring members 81A, 82A. This increases the length of the rib 63A in the radial direction. Therefore, the rigidity of the rotor 4A can be changed, and the natural frequency of the rotor 4A can be changed. Therefore, the occurrence of resonance can be suppressed, and the vibration characteristics of the rotor 4A can be adjusted to appropriate characteristics.

Further, the moment of inertia of the rotor 4A changes depending on the mass of the rotor 4A. The mass of the rotor 4A can be adjusted by changing the width in the circumferential direction R, the length in the radial direction, and the number of ribs 63A. As the moment of inertia becomes larger, a larger starting torque is required, but the rotation of the rotor 4A can be stabilized. As described above, in the modification of the fourth embodiment, since the resin portion 60A is connected to the ring members 81 and 82, the length of the rib 63A in the radial direction is longer. Thereby, the moment of inertia of the rotor 4A can be increased. Since the resin portion 60A is formed integrally with the ring members 81A and 82A in this manner, the natural frequency and moment of inertia of the rotor 4A can be adjusted to appropriate values.

《Embodiment 5》
Next, a blower 500 having the electric motor 100 according to the first embodiment will be described. FIG. 21 is a diagram schematically showing the configuration of a blower 500 according to the fifth embodiment.

As shown in FIG. 21, the blower 500 includes an electric motor 100 and a fan 501 as an impeller driven by the electric motor 100. Fan 501 is attached to the shaft of electric motor 100. When the shaft of electric motor 100 rotates, fan 501 rotates and airflow is generated. The blower 500 is used, for example, as an outdoor blower of an outdoor unit 620 of an air conditioner 600 shown in FIG. 22, which will be described later. In this case, fan 501 is, for example, a propeller fan.

<Effects of Embodiment 5>
According to the fifth embodiment described above, the blower 500 includes the electric motor 100 described in the first embodiment. As described above, since the electric motor 100 according to the first embodiment has improved reliability, the reliability of the blower 500 including the electric motor 100 can also be improved.

《Embodiment 6》
Next, an air conditioner 600 having the blower 500 shown in FIG. 21 will be described. FIG. 22 is a diagram showing the configuration of an air conditioner 600 according to the sixth embodiment.

As shown in FIG. 22, the air conditioner 600 includes an indoor unit 610, an outdoor unit 620, and a refrigerant pipe 630. The indoor unit 610 and the outdoor unit 620 are connected by a refrigerant pipe 630, thereby forming a refrigerant circuit in which refrigerant circulates. The air conditioner 600 can perform, for example, a cooling operation in which cold air is blown from the indoor unit 610 or a heating operation in which warm air is blown from the indoor unit 610 .

The indoor unit 610 includes an indoor blower 611 and a housing 612 that accommodates the indoor blower 611. The indoor blower 611 includes an electric motor 611a and a fan 611b driven by the electric motor 611a. Fan 611b is attached to the shaft of electric motor 611a. As the shaft of the electric motor 611a rotates, the fan 611b rotates and airflow is generated. The fan 611b is, for example, a crossflow fan.

The outdoor unit 620 includes a blower 500 as an outdoor blower, a compressor 621, and a housing 622 that accommodates the blower 500 and the compressor 621. The compressor 621 includes a compression mechanism section 621a that compresses refrigerant, and an electric motor 621b that drives the compression mechanism section 621a. The compression mechanism section 621a and the electric motor 621b are connected to each other by a rotating shaft 621c. Note that the electric motor 100 according to Embodiment 1 may be used as the electric motor 621b of the compressor 621.

For example, during cooling operation of the air conditioner 600, heat released when refrigerant compressed by the compressor 621 is condensed in a condenser (not shown) is released outdoors by the air blown by the blower 500. Note that the blower 500 according to the fifth embodiment may be used not only as the outdoor blower of the outdoor unit 620 but also as the indoor blower 611 described above. Further, the blower 500 is not limited to the air conditioner 600, but may be included in other equipment.

The outdoor unit 620 further includes a four-way valve (not shown) that switches the flow direction of the refrigerant. The four-way valve of the outdoor unit 620 allows the high-temperature, high-pressure refrigerant gas sent out from the compressor 621 to flow through the heat exchanger of the outdoor unit 620 during cooling operation, and to the heat exchanger of the indoor unit 610 during heating operation.

<Effects of Embodiment 6>
According to the sixth embodiment described above, the air conditioner 600 includes the blower 500. As described above, since the reliability of the blower 500 is improved by including the electric motor 100 described in the first embodiment, the reliability of the air conditioner 600 can also be improved.

1, 2, 3, 4, 4A rotor, 10 shaft, 20, 220, 320 ferrite bond magnet, 21 magnet body, 22a outer peripheral surface, 23 long groove, 23a first surface, 23b, 223b second surface, 23c , 223c third surface, 23d second end, 23e first end, 31, 331 rare earth bonded magnet, 41 first groove, 42 second groove, 50 rotor body, 60, 60A resin part , 81, 82, 81A, 82A ring member, 100 electric motor, 320c third end, 320d fourth end, 322g, 322p step, 353 first overhang, 354 second overhang, 500 blower , 501 fan, 600 air conditioner, 610 indoor unit, 620 outdoor unit, B1, B2, B3, B4 plane, C axis, W ₁ , W ₂ length, θ ₁ , θ ₂ , θ ₃ angle.

Claims (17)

a rotating shaft;
a rotor body supported by the rotating shaft;
The rotor main body has a first bonded magnet and a plurality of second bonded magnets,
The first bonded magnet includes a cylindrical magnet body and a plurality of long grooves that are provided on a first outer peripheral surface that is a radially outward surface of the magnet body and are long in the axial direction of the rotating shaft. have,
Each long groove of the plurality of long grooves is
the axially long first groove;
a second groove that extends outward in the width direction of the first groove and is shallower than the first groove;
The first groove portion is
a first surface that is the radially outward bottom surface;
a second surface that is connected to the first surface and is a side surface facing each other;
has
The second groove has a third surface connected to an end of the second surface on the first outer peripheral surface side,
The plurality of second bonded magnets are arranged so as to fill the insides of the plurality of long grooves. The rotor. The third surface is a bottom surface of the second groove,
The rotor according to claim 1 , wherein the second groove becomes shallower as the distance from the first groove increases. The rotor according to claim 1 or 2 , wherein the distance between the second surfaces facing each other becomes narrower as the distance from the first surface increases. The rotor according to any one of claims 1 to 3 , wherein the length of the third surface in the width direction is shorter than the length of the first outer peripheral surface in the width direction. From claim 1 , wherein the first outer circumferential surface of the first bonded magnet and the second outer circumferential surface of the second bonded magnet, which is the outward facing surface in the radial direction, are formed flush with each other. 4. The rotor according to any one of 4 . Two second surfaces disposed across the first outer circumferential surface of two adjacent long grooves of the plurality of long grooves are:
a first end that is closer to the rotation axis;
a second end that is a farthest end from the rotation axis;
The two second surfaces are:
A first angle that is a central angle between two planes connecting the axis of the rotating shaft and the first end is θ ₁ ,
When the second angle, which is the central angle between the two planes connecting the axis and the second end, is θ ₂ ,
θ ₁ <θ ₂
The rotor according to claim 1 , having a shape that satisfies the following. The number of poles of the rotor is 2n (n is an integer of 1 or more),
A third angle that is the inner angle in the radial direction among the angles formed by the surface connecting the axis and the second end and the second surface is θ ₃ ,
When
θ ₃ > (360°/(2・2n)) - (θ ₂ /2)
The rotor according to claim 6 . a rotating shaft;
the rotor body supported by the rotating shaft;
has
The rotor main body has a first bonded magnet and a plurality of second bonded magnets,
The first bonded magnet is
A cylindrical magnet body,
a plurality of long grooves provided in a first outer circumferential surface that is a radially outward surface of the magnet body and long in the axial direction of the rotating shaft;
a first step portion recessed from the first end in the axial direction toward one side in the axial direction ;
has
Each long groove of the plurality of long grooves is
the axially long first groove;
a second groove that extends outward in the width direction of the first groove and is shallower than the first groove;
has
The plurality of second bonded magnets are arranged so as to fill the plurality of long grooves,
Each second bonded magnet of the plurality of second bonded magnets has a first protruding portion joined to the first step portion.
rotor . The first bonded magnet further includes a second step portion recessed from a second end opposite to the first end in the axial direction toward the other axial direction,
The rotor according to claim 8 , wherein the second bonded magnet further includes a second projecting portion joined to the second step portion. The rotation according to any one of claims 1 to 9 , further comprising a first resin part arranged so as to cover the axial end faces of each of the first bonded magnet and the second bonded magnet. Child. further comprising a second resin part connecting the rotating shaft and the first bonded magnet,
The rotor according to claim 10 , wherein the second resin part is integrally formed with the first resin part. The rotor according to any one of claims 1 to 11 , wherein the first bonded magnet and the second bonded magnet each have polar anisotropy. The rotor according to any one of claims 1 to 12 , wherein the strength of the magnetic poles of the second bonded magnet is greater than the strength of the magnetic poles of the first bonded magnet. The first bonded magnet is a ferrite bonded magnet,
The rotor according to any one of claims 1 to 13 , wherein the second bonded magnet is a rare earth bonded magnet. The rotor according to any one of claims 1 to 14 ,
An electric motor having a stator and . The electric motor according to claim 15 ;
and an impeller driven by the electric motor. indoor unit and
an outdoor unit connected to the indoor unit;
At least one of the indoor unit and the outdoor unit includes the electric motor according to claim 15. An air conditioner.

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