JP7514663B2 - Rotor and method for manufacturing the rotor - Google Patents

Description

Embodiments of the present invention relate to rotors and methods for manufacturing rotors.

Patent document 1 describes a washing machine motor with multiple magnets arranged in the circumferential direction. It is preferable for such a washing machine motor to be small and have high torque.

Japanese Patent Application Laid-Open No. 10-42526

The problem that this invention aims to solve is to provide a rotor and a method for manufacturing the rotor that can position multiple magnets with high accuracy.

A manufacturing method of a rotor according to an embodiment includes a magnet arrangement step, a resin molding step, and a post-magnetization step. In the magnet arrangement step, a plurality of unmagnetized main magnets are formed in a columnar shape extending in the vertical direction along the rotation axis and have a first inclined surface that is a surface inclined with respect to the vertical direction at one end in the vertical direction , and are arranged in a ring-like or arc-like shape at intervals in the circumferential direction such that a circumferential surface of a die arranged on the stator side faces a side surface of the main magnets and a first normal to the first inclined surface faces the opposite side to the stator side in the radial direction and is inclined with respect to the rotation axis. In the resin molding step, the main magnets are moved to the stator side by directly or indirectly injecting molten resin into the first inclined surface from above the main magnets through the die, and the main magnets are molded with the resin. In the post-magnetization step, the resin-molded main magnets are magnetized.

A cross-sectional view perpendicular to the front-to-back direction of a washing machine. FIG. 2 is a perspective view of a rotor according to the embodiment. FIG. 4 is an enlarged perspective view of a portion of the rotor and the stator. 3 is a plan view of the outer periphery of the rotor shown in FIG. 2 as viewed from below the rotor. FIG. 5 is a cross-sectional view of the rotor shown in FIG. 4 taken along line A ₁ -A ₂ . 5 is a cross-sectional view of the rotor shown in FIG. 4 taken along line B ₂ -B ₂ . 5 is a view of only the rotor magnet shown in FIG. 4 as viewed from the opposite side (peripheral wall side). 5A to 5C are diagrams illustrating a flow for explaining a method for manufacturing a rotor according to an embodiment. FIG. 4 is a top view of multiple first and auxiliary magnets arranged in a mold. FIG. 10 is a cross-sectional view taken along line C ₁ -C ₂ of the structure shown in FIG. 9 . FIG. 10 is a cross-sectional view taken along line D ₁ -D ₂ of the structure shown in FIG. 9 . Cross-sectional view of the mold filled with resin (part 1). Cross-sectional view of the mold filled with resin (part 2). Top view of the rotor magnet molded with resin. FIG. 4 is a perspective view of the rotor when the rotor magnet is magnetized. Schematic diagram of the magnetizing yoke and part of the rotor magnet viewed from above during the homopolar magnetization process. FIG. 2 is a schematic diagram showing the magnetizing yoke and part of the rotor magnet viewed from above during the different pole magnetizing process. FIG. 2 is a schematic diagram showing the magnetization yoke and part of the rotor magnet after the different pole magnetization process, viewed from above. FIG. 11 is a cross-sectional view of a modified main magnet.

The manufacturing method of the rotor and roller of the washing machine of the embodiment will be described below with reference to the drawings. In the following description, components having the same or similar functions will be given the same reference numerals. Furthermore, duplicate descriptions of those components may be omitted.

In this specification, the side of the installation surface of the washing machine, i.e., the vertically lower side, is defined as the lower side of the washing machine, and the opposite side of the installation surface, i.e., the vertically upper side, is defined as the upper side of the washing machine. In addition, left and right are defined based on the direction in which the washing machine is viewed from a user standing in front of the washing machine. In addition, the side closer to the user standing in front of the washing machine as viewed from the washing machine is defined as the "front", and the side farther away is defined as the "rear".
In this specification, the "width direction" means the left-right direction as defined above. In this specification, the "depth direction" means the front-rear direction as defined above. In the drawings, the +X direction is the right direction, the -X direction is the left direction, the +Y direction is the rear direction, the -Y direction is the front direction, the +Z direction is the up direction, and the -Z direction is the down direction.

The rotor 20 of the washing machine 1 of this embodiment and the manufacturing method of the rotor 20 will be described in sequence with reference to Figures 1 to 7. First, the overall configuration of the washing machine 1 will be described with reference to Figure 1. However, the washing machine 1 and the rotor 20 do not need to have all of the configurations described below, and some configurations may be omitted as appropriate.

FIG. 1 is a cross-sectional view of a washing machine 1 taken along a line perpendicular to the front-rear direction.
Washing machine 1 includes a housing 11, a top cover 12, a water tub 13, a rotating tub 14, a pulsator 15, and a motor 16. Washing machine 1 is a so-called vertical axis type washing machine in which the rotation axis O of rotating tub 14 faces vertically. Note that washing machine 1 is not limited to the vertical axis type, and may be a horizontal axis type so-called drum type washing machine in which the rotation axis of the rotating tub is horizontal or inclined downward toward the rear.

The housing 11 is configured, for example, from steel plates in the shape of a rectangular box overall. The top cover 12 is configured, for example, from synthetic resin, and is provided on the top of the housing 11. The water tub 13 and the spin tub 14 function as a washing tub and a spin tub that hold the clothes to be washed. The water tub 13 and the spin tub 14 are provided inside the housing 11. The water tub 13 and the spin tub 14 are configured in the shape of a container with an open top. The water in the water tub 13 flows out from the drain port 18 and is drained to the outside via the drain valve 19.

The motor 16 has a flat cylindrical appearance with a diameter smaller than that of the water tank 13, and is attached to the underside of the water tank 13 so that the rotation axis O passes through its center.

Figure 2 is a perspective view of the rotor 20. Figure 3 is a perspective view of the rotor 20 and the stator 30. The motor 16 has a shaft 17, a rotor 20 (rotor), and a stator 30 (stator). The motor 16 is an outer rotor type induction motor in which the rotor 20 is provided outside the stator 30. The rotor 20 rotates by passing an alternating current through the stator coil 30c of the stator 30 to generate a rotating magnetic field. The shaft 17 is connected to the rotor 20 and rotates in accordance with the rotation of the rotor 20. The rotation axis of the shaft 17 coincides with the rotation axis O.

The shaft 17 is connected to the rotating tub 14 and the pulsator 15 via a clutch mechanism (not shown). The clutch mechanism selectively transmits the rotation of the motor 16 to the rotating tub 14 and the pulsator 15. During washing and rinsing, the motor 16 and clutch mechanism transmit the driving force of the motor 16 to the pulsator 15 while the rotation of the rotating tub 14 is stopped, directly driving the pulsator 15 to rotate forward and backward at a low speed. On the other hand, during dehydration, etc., the motor 16 and clutch mechanism transmit the driving force of the motor 16 to the rotating tub 14, driving the rotating tub 14 and pulsator 15 to rotate at high speed in one direction.

The rotor 20 is a flat, bottomed, cylindrical member. The rotor 20 has a disk-shaped bottom wall portion 21 with an opening in the center, a cylindrical peripheral wall portion 22 (frame) erected on the periphery of the bottom wall portion 21, a rotor magnet 23, and resin 24. The bottom wall portion 21 and the peripheral wall portion 22 are formed by pressing an iron plate so as to function as a back yoke. The bottom wall portion 21 has a number of slits 21a formed therein for dissipating heat.

The rotor magnet 23 is fixed to the inside of the peripheral wall portion 22 via resin 24. The rotor magnet 23 has a plurality of main magnets 25 and a plurality of auxiliary magnets 26. The main magnets 25 and the auxiliary magnets 26 are arranged alternately in the circumferential direction C. The length of the main magnets 25 in the circumferential direction C is longer than the length of the auxiliary magnets 26 in the circumferential direction C. The main magnets 25 and the auxiliary magnets 26 are resin molded with the resin 24.

The rotor magnet 23 is, for example, a Halbach array magnet in which the main magnet 25 and the auxiliary magnet 26 are arranged in a Halbach array.

For example, it is preferable to use ferrite magnets as the main magnet 25 and the auxiliary magnet 26 from the viewpoint of magnetization. Other magnets, such as neodymium magnets, may also be used as the main magnet 25 and the auxiliary magnet 26.

Fig. 4 is a plan view of the outer periphery of the rotor 20 viewed from the lower side of the rotor 20 shown in Fig. 2. For convenience of explanation, Fig. 4 omits illustration of the resin 24 formed on the end faces 25b, 26b, the first inclined faces 25d, and the second inclined faces 26c. Fig. 5 is a cross-sectional view of the rotor 20 shown in Fig. 4 taken along line _A1 - _A2 . The up-down direction in Fig. 5 is inverted from the up-down direction in Figs. 2 and 3.

The main magnet 25 is columnar and extends in the vertical direction. As shown in FIG. 5, the main magnet 25 has an end face 25a, an end face 25b arranged opposite the end face 25a, a side face 25c, and a first inclined face 25d.

End face 25a and end face 25b are planes that are approximately perpendicular to the up-down direction. End face 25a is located on the upper side (+Z side). End face 25b is located on the lower side (-Z side). Side face 25c is located on stator side R1 (stator 30 side). At least a portion of side face 25c is exposed from resin 24. Since side face 25c on stator side R1 is not entirely covered with resin 24, it is possible to suppress a decrease in the magnetic force of main magnet 25 due to resin molding.

The first inclined surface 25d is disposed on the opposite side R2 of the stator side R1 (the peripheral wall portion 22 side in this embodiment) and is connected to the end face 25b. The first inclined surface 25d is inclined with respect to the end face 25b. The first normal N1 of the first inclined surface 25d faces the opposite side R2 of the stator side R1 in the radial direction R and is inclined with respect to the rotation axis O. The first inclined surface 25d may be, for example, a flat surface or a curved surface.

In the rotor 20 shown in FIG. 2, the first inclined surface 25d and the end surface 25b are located on the lower side (-Z side).

FIG. 6 is a cross-sectional view of the rotor 20 shown in FIG. 4 taken along line B ₂ -B ₂ .
The auxiliary magnet 26 has a columnar shape extending in the vertical direction and has an end face 26a, an end face 26b disposed on the opposite side to the end face 26a, and a second inclined face 26c.

End face 26a and end face 26b are planes that are approximately perpendicular to the up-down direction. End face 26a is disposed on the upper side (+Z side). End face 26b is disposed on the lower side (-Z side). End face 26a is disposed so as to be approximately flush with end face 25a of main magnet 25.

The second inclined surface 26c is disposed on the stator side R1 and is connected to the end surface 26b. The second inclined surface 26c is inclined with respect to the end surface 26b. The second normal N2 of the second inclined surface 26c faces the stator side R1 in the radial direction R and is inclined with respect to the rotation axis O. The second inclined surface 26c may be, for example, a flat surface or a curved surface.

It is preferable that adjacent main magnets 25 and auxiliary magnets 26 are in at least partial contact with each other. This makes it possible to arrange the main magnets 25 and auxiliary magnets 26 closely together in the circumferential direction C.

The main magnet 25 is preferably shaped to prevent the auxiliary magnet 26 from moving to the opposite side R2 when it comes into contact with the auxiliary magnet 26. The shapes of the main magnet 25 and the auxiliary magnet 26 are trapezoidal (e.g., isosceles trapezoidal) in a plan view from the top-bottom direction, as shown in FIG. 4, for example. In a plan view from the top-bottom direction, the upper base of the main magnet 25 is disposed on the stator side R1, and the upper base of the auxiliary magnet 26 is disposed on the opposite side R2. That is, the positions of the upper base of the main magnet 25 and the upper base of the auxiliary magnet 26 in the radial direction R are different. With such a shape, when positioning the main magnet 25 and the auxiliary magnet 26, the main magnet 25 and the auxiliary magnet 26 can be brought into contact with each other to regulate the positioning of the auxiliary magnet 26.

FIG. 7 is a view of only the rotor magnet 23 shown in FIG. 4 as viewed from the opposite side R2.
The height H2 of the auxiliary magnet 26 is preferably set lower than the height H1 of the main magnet 25. That is, the first inclined surface 25d is preferably disposed so as to protrude further in the axial direction of the rotation axis O than the second inclined surface 26c. This makes it easier for the molten resin to reach the first inclined surface 25d before the second inclined surface 26c in the resin molding process described later.

The resin 24 is fixed to the inner circumferential surface of the peripheral wall portion 22 with the main magnet 25 and the auxiliary magnet 26 resin-molded. In other words, the rotor magnet 23 is fixed to the peripheral wall portion 22 via the resin 24.

The stator 30 (stator) has a circular stator core 30a whose outer diameter is smaller than the inner diameter of the rotor 20, magnetic pole teeth 30b that protrude outward from the outer periphery of the stator core 30a, and a stator coil 30c that is wound around the magnetic pole teeth 30b.

Next, a manufacturing method of the rotor 20 will be described with reference to Fig. 8 to Fig. 19. Fig. 8 is a diagram showing a flow for explaining the manufacturing method of the rotor 20. Fig. 9 is a top view of the main magnets 25 and the auxiliary magnets 26 arranged in a mold 35. For convenience of explanation, the upper side of the mold 35 is omitted in Fig. 9. Fig. 10 is a cross-sectional view of the structure shown in Fig. 9 taken along line _C1 - _C2 . Fig. 11 is a cross-sectional view of the structure shown in Fig. 9 taken along line _D1 - _D2 .

First, in the magnet arrangement process S1, unmagnetized main magnets 25 and unmagnetized auxiliary magnets 26 are arranged alternately in a circular shape within the mold 35 (see Figures 9 to 11). When the rotor 20 is manufactured, the end face 25b of the main magnet 25 and the end face 26b of the auxiliary magnet 26 are arranged vertically upward. In other words, the rotor 20 installed in the washing machine 1 and the rotor 20 at the time of manufacture are oriented in the opposite up-down direction.

The mold 35 has an annular internal cavity into which resin can be pressed. As shown in FIG. 9, a plurality of resin introduction holes 35A for pressing molten resin into the mold 35 are formed at intervals in the circumferential direction C on the upper side of the mold 35. The internal cavity of the mold 35 is partitioned on the opposite side R2 in the radial direction R by the peripheral wall portion 22. Note that a mold may be used in place of the peripheral wall portion 22.

The main magnet 25 is arranged so that the first normal N1 of the first inclined surface 25d faces the opposite side R2 in the radial direction R and is inclined with respect to the rotation axis O, and the first inclined surface 25d faces diagonally upward. The main magnet 25 is also arranged so that the side surface 25c faces the peripheral surface 36a of the mold 35.

On the other hand, the auxiliary magnet 26 is arranged so that the second normal N2 of the second inclined surface 26c faces the stator side R1 in the radial direction R, is inclined with respect to the rotation axis O, and faces diagonally upward. At this stage, the main magnet 25 and the auxiliary magnet 26 are not yet magnetized, so they can be arranged close to each other in the circumferential direction C.

Figures 12 and 13 are cross-sectional views of the mold 35 filled with resin 24. Figure 14 is a top view of the rotor magnet 23 molded with resin 24. For ease of explanation, Figure 14 omits the illustration of the resin 24 formed on the upper side of the mold 35, the main magnet 25, and the auxiliary magnet 26.

Next, in the resin molding process S2, the molten resin is injected into the mold 35 through the resin introduction hole 35A, thereby resin-molding the rotor magnet 23 with the resin 24 (see Figures 12 to 14). Because the resin introduction hole 35A is formed above the first inclined surface 25d and the second inclined surface 26c, the molten resin is easily supplied directly to the first inclined surface 25d and the second inclined surface 26c.

Because the height H1 of the main magnet 25 is greater than the height H2 of the auxiliary magnet 26, the molten resin is likely to reach the first inclined surface 25d before the second inclined surface 26c. Then, when the molten resin reaches the first inclined surface 25d, the main magnet 25 receives a force from the stator side R1 (E side) in the direction along the first normal N1 and moves to the stator side R1, and the side surface 25c comes into contact with the circumferential surface 36a, completing the positioning of the main magnet 25.

Next, the molten resin also reaches the second inclined surface 26c. When the molten resin reaches the second inclined surface 26c, the auxiliary magnet 26 receives a force on the opposite side R2 (F side) in the direction along the second normal N2 and moves to the opposite side R2, completing the positioning of the auxiliary magnet 26.

As shown in FIG. 4, the shapes of the main magnet 25 and the auxiliary magnet 26 are trapezoidal in plan view from the top and bottom. In the circumferential direction C, the main magnet 25 and the auxiliary magnet 26 contact each other, restricting the positioning of the auxiliary magnet 26 to a certain extent.

As shown in FIG. 7, the height H1 of the main magnet 25 is greater than the height H2 of the auxiliary magnet 26, so the molten resin is more likely to reach the first inclined surface 25d before the second inclined surface 26c. Therefore, even if the resin 24 is simultaneously injected into the mold 35 through multiple resin introduction holes 35A, the main magnet 25 can be positioned preferentially.

By moving the main magnet 25 before the auxiliary magnet 26, it is possible to prevent molten resin from entering between the peripheral surface 36a of the mold 35 and the side surface 25c of the main magnet 25. As a result, after the resin molding process, at least a portion of the side surface 25c of the stator side R1 can be exposed from the resin 24. Since the entire side surface 25c of the stator side R1 is not covered with the resin 24, it is possible to prevent a decrease in the magnetic force of the main magnet 25 due to resin molding.

In the mold removal process S3, when the resin 24 in the mold 35 has hardened, the rotor magnet 23 fixed to the peripheral wall portion 22 via the resin 24 is removed from the mold 35. The rotor magnet 23 may be formed into an annular shape by combining pieces that have been divided into arc-shaped pieces and molded from resin.

FIG. 15 is a perspective view of the rotor 20 when the rotor magnet 23 is magnetized.
In the post-magnetization step S4, the rotor magnet 23 is inserted into a magnetization device (not shown) to magnetize the main magnets 25 and the auxiliary magnets 26. The post-magnetization step includes a same-polarity magnetization step and a different-polarity magnetization step.

By using, for example, ferrite magnets as the main magnet 25 and the auxiliary magnet 26, magnetization can be performed more effectively in the post-magnetization process compared to when neodymium magnets are used.

The magnetizing device has four magnetizing yokes (first magnetizing yoke 40A, second magnetizing yoke 40B, third magnetizing yoke 40C, and fourth magnetizing yoke 40D). The four magnetizing yokes are connected to a magnetizing power source (not shown). The magnetizing device may have a number of magnetizing yokes that can magnetize all of the main magnets 25 and auxiliary magnets 26 simultaneously, for example.

The first magnetizing yoke 40A and the second magnetizing yoke 40B are arranged opposite each other, on either side of the plate thickness direction (radial direction R) of one main magnet 25. The first magnetizing yoke 40A is arranged on the outside in the radial direction R, and the second magnetizing yoke 40B is arranged on the inside in the radial direction R. In the opposite pole magnetization process described below, opposite pole magnetic fields are generated in the opposing first magnetizing yoke 40A and second magnetizing yoke 40B, so that the sandwiched main magnet 25 is magnetized in one direction (opposite magnetization).

The third magnetizing yoke 40C and the fourth magnetizing yoke 40D are arranged opposite each other. The third magnetizing yoke 40C and the fourth magnetizing yoke 40D are arranged on both sides in the plate thickness direction (radial direction R) of the main magnet 25 next to the main magnet 25 sandwiched between the first magnetizing yoke 40A and the second magnetizing yoke 40B. The third magnetizing yoke 40C is arranged on the outside in the radial direction R, and the fourth magnetizing yoke 40D is arranged on the inside in the radial direction R. In the opposite pole magnetization process described later, opposite pole magnetic fields are generated in the opposing third magnetizing yoke 40C and fourth magnetizing yoke 40D, so that the sandwiched main magnet 25 is magnetized in one direction (opposite magnetization).

In the following description, the unmagnetized main magnet 25 sandwiched between the first magnetizing yoke 40A and the second magnetizing yoke 40B is referred to as the "main magnet 25A," and the unmagnetized main magnet 25 sandwiched between the third magnetizing yoke 40C and the fourth magnetizing yoke 40D is referred to as the "main magnet 25B." The unmagnetized auxiliary magnet 26 adjacent to the main magnet 25A and the main magnet 25B in the circumferential direction C is referred to as the "auxiliary magnet 26C."

FIG. 16 is a schematic diagram showing the magnetizing yoke and part of the rotor magnet 23 viewed from above in the same-polarity magnetizing process.
As shown in Fig. 16, a magnetic field of the same polarity is generated in the opposing first magnetizing yoke 40A and second magnetizing yoke 40B. In addition, a magnetic field of the same polarity is generated in the opposing third magnetizing yoke 40C and fourth magnetizing yoke 40D. Here, the magnetic field generated in the third magnetizing yoke 40C and the fourth magnetizing yoke 40D has a polarity different from that of the magnetic field generated in the first magnetizing yoke 40A and the second magnetizing yoke 40B. By the same polarity magnetization process, the auxiliary magnet 26C is magnetized in the circumferential direction C.

FIG. 17 is a schematic diagram showing the magnetizing yoke 40 and part of the rotor magnet 23 viewed from above in the different pole magnetizing process.
17, magnetic fields of opposite polarity are generated in the opposing first magnetizing yoke 40A and second magnetizing yoke 40B (opposite polarity magnetization process). Here, the magnetic field generated in the fourth magnetizing yoke 40D has a polarity opposite to that of the magnetic field generated in the second magnetizing yoke 40B. Through the opposite polarity magnetization process, the main magnet 25A is magnetized in the radial direction R. Furthermore, the main magnet 25B is magnetized in the radial direction R. Through the same polarity magnetization process, the magnetic orientations of the magnetized main magnets 25A and 25B face opposite directions in the radial direction R.

Figure 18 is a schematic diagram of the magnetization yoke 40 and part of the rotor magnet 23 viewed from above after the opposite pole magnetization process. As shown in Figure 18, the magnetic orientations of the main magnets 25A and 25B magnetized by the same pole magnetization process face in opposite directions in the radial direction R. In addition, the magnetic orientation of the auxiliary magnet 26C faces the circumferential direction C.

Then, the same-pole magnetization process and the opposite-pole magnetization process are repeated to magnetize the remaining main magnets 25 and auxiliary magnets 26, and the rotor magnet 23 is converted into a known Halbach array magnet. The rotor magnet 23 that has undergone the post-magnetization process is then combined with the bottom wall portion 21 and the peripheral wall portion 22 to complete the rotor 20.

According to the manufacturing method of the rotor 20 according to this embodiment, the multiple main magnets 25 are moved by directly or indirectly supplying molten resin to the multiple first inclined surfaces 25d, and the side surfaces 25c of the multiple main magnets 25 are brought into contact with the peripheral surface 36a of the die 35. This allows the multiple main magnets 25 to be positioned with high precision even when there are dimensional tolerances or molding variations between the multiple main magnets 25. In addition, by moving the main magnets 25 before the auxiliary magnets 26, it is possible to prevent the molten resin from entering between the peripheral surface 36a of the die 35 and the side surfaces 25c of the main magnets 25, and at least a portion of the side surfaces 25c of the stator side R1 can be exposed from the resin 24.

In addition, by supplying molten resin to the second inclined surfaces 26c, the auxiliary magnets 26 can be positioned. Furthermore, by making the shape of the main magnet 25 such that the auxiliary magnets 26 can be prevented from moving to the opposite side of the stator side R1, the position of the auxiliary magnets 26 after positioning can be regulated.

Furthermore, in the resin molding process, the movement of the main magnets 25 and the auxiliary magnets 26 can increase the fluidity of the molten resin.
Furthermore, by arranging the main magnets 25 and the auxiliary magnets 26 at high density in the circumferential direction C, the magnetic force of the rotor 20 can be increased, thereby improving the torque of the motor 16.

(Variation 1)
FIG. 19 shows a main magnet 45 which is a modification of the main magnet 25 .
A main magnet 45 may be used instead of the main magnet 25 described in the above embodiment. The main magnet 45 further has an inclined surface 25e having a smaller area than the first inclined surface 25d formed at an end 45A on the side where the first inclined surface 25d is formed. The first inclined surface 25d of the main magnet 45, which has a larger area than the inclined surface 25e, receives a larger force from the molten resin. As in the above embodiment, the main magnet 45 moves in a direction toward the peripheral surface 36a of the mold 35, so that the side surface 25c of the main magnet 45 can come into contact with the peripheral surface 36a of the mold 35 (see FIG. 12).

In FIG. 19, an example is shown in which one inclined surface 25e is formed on end 45A, but multiple inclined surfaces 25e may be formed on end 45A. In addition, at least one inclined surface (not shown) having an area smaller than that of second inclined surface 26c may be formed on the end on which second inclined surface 26c of auxiliary magnet 26 described above is formed.

(Variation 2)
In the above embodiment, the rotor 20 is an outer rotor, but the rotor is not limited to this. The rotor may be an inner rotor.

(Variation 3)
In the above embodiment, the rotor magnet 23 has the main magnet 25 and the auxiliary magnet 26, but the rotor magnet 23 may be composed of only a plurality of main magnets 25. In other words, the rotor magnet 23 is not limited to a Halbach array magnet.

According to at least one of the embodiments described above, by having a main magnet 25 including a first inclined surface 25d, the positioning of multiple main magnets 25 can be performed with high precision.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and gist of the invention.

1...washing machine, 11...casing, 12...top cover, 13...water tub, 14...rotating tub, 15...pulsator, 16...motor, 17...shaft, 18...drain outlet, 19...drain valve, 20...rotor, 22...peripheral wall, 23...rotor magnet, 23...resin, 25, 25A, 25B, 45...main magnet, 25a, 25b, 26a, 26b...end surface, 25c...side surface, 25d...first inclined surface, 25e...inclined surface, 26, 26C...auxiliary magnet 26c...second inclined surface, 30...stator, 30a...stator core, 30b...magnetic pole teeth, 30c...stator coil, 35...mold, 35A...resin introduction hole, 36...side wall, 36a...periphery, 40A...first magnetized yoke, 40B...second magnetized yoke, 40C...third magnetized yoke, 40D...fourth magnetized yoke, 45A...end, H1, H2...height, N1...first normal, N2...second normal, O...rotation axis, R1...stator side, R2...opposite side

Claims (9)

a magnet arrangement process for arranging a plurality of unmagnetized main magnets , each of which is formed in a columnar shape extending in a vertical direction along the rotation axis and has a first inclined surface that is a surface inclined with respect to the vertical direction at one end in the vertical direction , in a circular ring shape or a circular arc shape spaced apart in the circumferential direction, with a first normal line of the first inclined surface facing the opposite side to the stator side in the radial direction and inclined with respect to the rotation axis, so that the circumferential surface of a die arranged on the stator side faces the side of the main magnets;
a resin molding process in which molten resin is directly or indirectly injected from above the main magnet into the first inclined surface through the die to move the main magnet toward the stator , and the main magnet is molded with the resin;
a post-magnetization process of magnetizing the resin-molded main magnet;
A method for manufacturing a rotor comprising: In the magnet arrangement step, a plurality of unmagnetized auxiliary magnets each having a columnar shape extending in the vertical direction and a second inclined surface at one end in the vertical direction that is a surface inclined with respect to the vertical direction are arranged between the main magnets adjacent to each other in the circumferential direction such that a second normal to the second inclined surface faces the stator side in the radial direction and is inclined with respect to the rotation axis,
In the post-magnetization process, the resin-molded main magnet and the auxiliary magnet are magnetized.
A method for manufacturing the rotor according to claim 1 . In the resin molding process, the main magnet is moved toward the stator by supplying resin to the first inclined surface, and the auxiliary magnet is moved to the opposite side by supplying molten resin to the second inclined surface.
A method for manufacturing the rotor according to claim 2. In the resin molding process, the main magnet is moved toward the stator by supplying resin to the first inclined surface, and the peripheral surface of the die and the side surface of the main magnet are brought into contact with each other, so that at least a part of the side surface of the main magnet is exposed from the resin.
A method for manufacturing the rotor according to claim 2. 5. The method of manufacturing a rotor according to claim 2, wherein in the post-magnetization step, the main magnets are magnetized in the radial direction, and the auxiliary magnets are magnetized in the circumferential direction. a main magnet formed in a columnar shape extending in a vertical direction along a rotation axis, arranged in a circular shape with intervals between each other, the main magnet having a side face arranged on the stator side and a first inclined surface which is a surface inclined with respect to the vertical direction at one end in the vertical direction , a first normal line of the first inclined surface facing the opposite side to the stator side in the radial direction and inclined with respect to the rotation axis;
a resin that molds the main magnet and exposes at least a portion of the side surface of the main magnet;
Equipped with
The auxiliary magnets are provided between adjacent main magnets in the circumferential direction,
The auxiliary magnet is formed in a columnar shape extending in the vertical direction, and has a second inclined surface that is a surface inclined with respect to the vertical direction at the one end in the vertical direction,
a second normal line of the second inclined surface faces the stator in the radial direction and is inclined with respect to the rotation axis,
The first inclined surface is disposed so as to protrude in the axial direction of the rotation shaft more than the second inclined surface.
Rotor. The auxiliary magnets are at least partially in contact with the main magnets adjacent to each other in the circumferential direction.
A rotor according to claim 6. The main magnet is a magnet magnetized in the radial direction,
The auxiliary magnet is a magnet magnetized in the circumferential direction.
A rotor according to claim 6 or claim 7. a main magnet formed in a columnar shape extending in a vertical direction along a rotation axis, arranged in a circular shape with intervals between each other, the main magnet having a side face arranged on the stator side and a first inclined surface which is a surface inclined with respect to the vertical direction at one end in the vertical direction, a first normal line of the first inclined surface facing the opposite side to the stator side in the radial direction and inclined with respect to the rotation axis;
a resin that molds the main magnet and exposes at least a portion of the side surface of the main magnet;
Equipped with
When the resin is viewed from the one side in the up-down direction, a trace of a resin introduction hole is formed at a position overlapping with at least one of the molded first inclined surfaces.
Rotor.

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