Manufacturing method of rotor magnet

Abstract

To provide a rotor magnet manufacturing method enabling easy manufacturing of a rotor magnet having a main magnet and an auxiliary magnet in which magnetic orientations are mutually different.SOLUTION: A rotor of a permanent magnet motor includes a Halbach array magnet composed of a plurality of main magnets which are magnetically orientated in the radial direction, and a plurality of auxiliary magnets which are magnetically orientated in the circumferential direction and arranged among the main magnets. The rotor magnet manufacturing method includes: generating divided resin molding parts by resin molding the main magnets which is in a non-magnetization state and the auxiliary magnets which is magnetized in a circumferential direction, in a state of being arrayed in a circular arc obtained by dividing the circumference into a plurality of pieces; and magnetizing the main magnets of the divided resin molding parts in the radial direction, to connect the plurality of divided resin molding parts into a circumferential shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a method for manufacturing a rotor magnet in a rotor of a permanent magnet motor having main magnets and auxiliary magnets with different magnetic orientations. By law Regarding. [Background technology]

[0002] Patent Document 1 discloses the following method for manufacturing a Halbach array magnet. A plurality of radially magnetized first magnets are arranged at predetermined intervals in a ring-shaped space, and a plurality of second cavities are formed in which the circumferential wall surfaces are formed by the first magnets. The second cavities are filled with molten resin for magnet production, and the filled molten resin is magnetized in the circumferential direction by a second magnetizing unit arranged near the second cavities, and the first magnets and second magnets are removed from the ring-shaped space. In this way, the Halbach array magnet is resin-molded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-50179 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a fixed mold and a movable mold are used in the above manufacturing, and a second magnetizing part for magnetizing the second magnet in the circumferential direction is disposed in the movable mold. This second magnetizing part has a complicated structure as described in paragraph

[0044] of Patent Document 1, and it is very difficult to magnetize the second magnet in the circumferential direction when filling the second cavity with molten resin using such a second magnetizing part.

[0005] Therefore, a method for manufacturing a rotor magnet that can more easily manufacture a rotor magnet having a main magnet and an auxiliary magnet with different magnetic orientations is provided. Law provide. [Means for solving the problem]

[0006] The method for manufacturing a rotor magnet of this embodiment is to manufacture a rotor for a permanent magnet motor having magnets composed of a plurality of main magnets magnetically oriented in a first direction, and a plurality of auxiliary magnets magnetically oriented in a second direction different from the first direction and disposed between the main magnets. Manufacturing method of rotor magnet In a main magnet in an unmagnetized state and an auxiliary magnet magnetized in a second direction are arranged in an arc shape that divides a circumference into a plurality of parts, and then resin-molded to generate a divided resin-molded portion; A main magnet of the divided resin molding portion is magnetized in a first direction; A plurality of divided resin molded parts are connected in a circumferential shape, When combined with a stator, the main magnet of In a direction facing the stator The opposite side of the face One end of the auxiliary magnet is disposed at a position facing a magnetic sensor whose position is fixed relative to the stator. of In a direction facing the stator The opposite side of the face One end is not in the position. The main magnet and the auxiliary magnet To arrange.

[0007] In addition, the manufacturing method of the rotor magnet of this embodiment is the same as that of the rotor magnet described above. How magnets are manufactured a main magnet in an unmagnetized state and an auxiliary magnet magnetized in a second direction are arranged in an arc shape that divides a circumference into a plurality of parts, and then resin-molded to generate a divided resin-molded portion; The multiple divided resin molded parts are connected in a circular shape and then assembled to the rotor frame. A main magnet of the divided resin molding portion is magnetized in a first direction; When combined with a stator, the main magnet of In a direction facing the stator The opposite side of the face One end of the auxiliary magnet is disposed at a position facing a magnetic sensor whose position is fixed relative to the stator. of In a direction facing the stator The opposite side of the face One end is not in the position. The main magnet and the auxiliary magnet To arrange. [Brief description of the drawings]

[0009] [Figure 1] 1 is a plan view, a front view, and a side view of a divided resin part according to a first embodiment. [Diagram 2] FIG. 1 is a diagram illustrating a state in which a divided resin portion is resin-molded using a molding die. [Diagram 3] Flowchart showing the rotor manufacturing process [Figure 4] A perspective view showing the completed rotor. [Diagram 5] Perspective view of part of a permanent magnet motor (part 1) [Figure 6] Perspective view of part of a permanent magnet motor (part 2) [Figure 7] A diagram showing the signal waveform output by the magnetic sensor when the rotor is rotating. [Figure 8] FIG. 7 shows a case where there is no step in the axial arrangement of the main magnet and the auxiliary magnet. [Figure 9] 10 is a flowchart showing a rotor manufacturing process according to a second embodiment. [Figure 10] FIG. 13 is a perspective view showing a divided resin portion according to a third embodiment. [Figure 11] FIG. 13 is a perspective view showing a divided resin portion according to a fourth embodiment. [Figure 12] FIG. 13 is a perspective view of a permanent magnet motor according to a fifth embodiment, showing a rotor yoke in a see-through state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (First embodiment) FIG. 1 shows a split resin molded part 1 of a rotor magnet equipped with a Halbach array magnet of this embodiment. The split resin molded part 1 is molded from resin 4 with eight main magnets 2 and eight auxiliary magnets 3 arranged alternately, forming an arc shape with a central angle of 60 degrees. The main magnets 2 have vertical and horizontal dimensions of 30×10.42 mm, and the auxiliary magnets 3 have vertical and horizontal dimensions of 30×5.25 mm. The thickness of the auxiliary magnets 3 is set to be slightly thinner than the main magnets 2. The height of the split resin molded part 1 is 38 mm, and at the upper part in the figure, a step is formed so that the upper surface of the auxiliary magnets 3 is 2 mm higher than the main magnets 2. In this embodiment, the longitudinal direction of the magnets 2 and 3 is the axial direction, that is, the vertical direction described above. The horizontal dimension of the split resin molded part 1 is 104.37 mm, and the vertical dimension is 70.76 mm.

[0011] FIG. 2 is an image of the case where a split resin molded part 1 is resin molded. At this stage, the main magnets 2 are not yet magnetized, and the auxiliary magnets 3 are magnetized in the circumferential direction. The main magnets 2 and auxiliary magnets 3 are arranged alternately and housed in a core 5 and cavity 6, which are metal molds. A positioning insert 7, a magnet ejection pin 8, and a resin part ejection pin 9 are arranged below the core 5 in the figure. Meanwhile, a magnet holding pin 10 and a resin filling gate 11 are arranged on the cavity 6 side, which is above in the figure. Resin 4 is filled through the resin filling gate 11 and molding is performed.

[0012] Fig. 3 is a flow chart showing the rotor manufacturing process. The unmagnetized main magnet 2 and the magnetized auxiliary magnet 3 are inserted into a resin molding die (S1, S2), and the two magnets 2, 3 are alternately arranged in an arc shape (S3). Then, the two magnets 2, 3 are fixed by magnet ejection pins 8 (S4), and resin 4 is filled through multiple gates 11 (S5). The molded divided resin molded parts 1 are removed (S6), inserted into a magnetizing device (S7), and the main magnet 2 is magnetized (S8). At this point, the divided resin molded parts 1 are completed (S9). Six divided resin molded parts 1 are assembled into a ring shape to form a circumference (S10), and inserted into the inner circumference of the rotor yoke 12 shown in Fig. 4 (S11) to complete the rotor 13 (S12).

[0013] 5 and 6 show an example in which a magnetic sensor such as a Hall sensor is disposed on the rotor 13 to detect the rotational position. These figures also show a part of the stator 23 including the stator yoke 21 and the coil 22. The lower end face of the auxiliary magnet 3, which is at the top in the figures, is at the same position as the lower end face of the rotor yoke 12 or slightly lower than the lower end face. In contrast, the lower end face of the main magnet 2 is higher than the lower end face of the rotor yoke 12. In other words, the lower end faces of both magnets 2, 3 are arranged so as to form a step, that is, a concave-convex shape.

[0014] 6, the three magnetic sensors 24 are supported by a support member (not shown) with a slight gap between them and the lower end surface of the rotor yoke 12. As a result, when the rotor 13 rotates, the magnetic sensors 24 are positioned so that the concave portions of the concave and convex portions of the lower end surface are engaged. The rotor 13, the stator 23, and the magnetic sensors 24 constitute a radial gap type permanent magnet motor 25.

[0015] Fig. 7 shows the waveform of the signal output by the magnetic sensor when the rotor 13 is rotating with the magnetic sensor arranged as shown in Fig. 5 and Fig. 6. Fig. 8 shows the same waveform when no step is provided in the axial arrangement of the main magnet 2 and auxiliary magnet 3. By providing the step, leakage magnetic flux is suppressed, and there is no dropout or variation in the output signal from the magnetic sensor, making it possible to stably perform magnetic pole discrimination.

[0016] In this embodiment, since the vertical dimensions of the main magnet 2 and the auxiliary magnet 3 are the same, a step is also formed on the upper end surface by providing a step on the lower end surface side on the side where the magnetic sensor 24 is arranged. Alternatively, the vertical dimensions of the main magnet 2 and the auxiliary magnet 3 can be made different, so that the upper end surface side has a structure without a step.

[0017] As described above, according to this embodiment, when manufacturing a rotor magnet using a Halbach array magnet consisting of a plurality of main magnets 2 magnetically oriented in the radial direction and a plurality of auxiliary magnets 3 magnetically oriented in the circumferential direction and arranged between the main magnets 2, the unmagnetized main magnets 2 and the auxiliary magnets 3 magnetized in the circumferential direction are resin-molded in a state in which they are arranged in an arc shape that divides the circumference into a plurality of parts, thereby generating the divided resin molded parts 1. Then, the main magnets 2 of each divided resin molded part 1 are magnetized in the radial direction, and the divided resin molded parts 1 are connected in a circumferential shape. This simplifies the assembly of a rotor magnet having a Halbach array magnet. In addition, since the divided resin molded parts 1 are connected after the magnets 2 and 3 are magnetized, the magnetization of each of the magnets 2 and 3 can be easily performed.

[0018] In this case, the rigidity of the split resin molded portion 1 can be improved by setting the radial thickness dimension of the auxiliary magnet 3 to be thinner than that of the main magnet 2. Also, by providing a step on the end face side of the main magnet 2 and the auxiliary magnet 3 facing the magnetic sensor, the rigidity of the split resin molded portion 1 can be improved and the magnetic pole discrimination by the magnetic sensor can be stably performed.

[0019] Second embodiment Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the different parts will be described. In the second embodiment, the manufacturing process of the rotor is slightly different. As shown in FIG. 9, after the steps up to step S7 are performed, steps S10 and S11 are performed without magnetizing the main magnet 2. Then, with the ring-shaped divided resin molded part 1 inserted into the inner periphery of the rotor frame 12, the main magnet 2 is magnetized by a magnetizing device (S13). This completes the rotor 13 (S14). According to the second embodiment, the main magnet 2 is magnetized with the ring-shaped divided resin molded part 1 inserted into the rotor frame 12, so that the magnetic repulsive force or attractive force of the magnets 2 and 3 does not act during assembly, and assembly can be easily performed.

[0020] (Third and fourth embodiments) 10 and 11 are third and fourth embodiments, respectively, showing other configuration examples of the split resin part. In the third embodiment shown in Fig. 10, the thickness dimension of the auxiliary magnet 14 is the same as that of the main magnet 2, and the split resin part 15 is configured without a step as in the first embodiment, and the configuration corresponds to the signal waveform of the magnetic sensor shown in Fig. 8.

[0021] In the fourth embodiment shown in FIG. 11, in the configuration of the third embodiment, the thickness of the auxiliary magnet 16 is made thinner than that of the main magnet 2 to form a divided resin portion 16, similarly to the first embodiment.

[0022] Fifth embodiment Fig. 12 shows the fifth embodiment applied to an axial gap type permanent magnet motor 31. In this motor 31, a rotor 32 is located at the top of the figure, and a stator 33 is located below. A rotor yoke 34 shown in a see-through state in the figure is composed of a ring-shaped flat plate, and a main magnet 35 and an auxiliary magnet 36 are arranged on the underside of the rotor yoke 34. The main magnet 35 is magnetically oriented from bottom to top, i.e., in the axial direction. The auxiliary magnet 36 is magnetically oriented in the circumferential direction, similar to the first embodiment, etc.

[0023] The radial length, which is the longitudinal direction of the main magnet 35, is set to be longer than the radial length of the auxiliary magnet 36. The radial end of the main magnet 35 protrudes outward from the outer edge of the rotor yoke 34. The radial end face of the auxiliary magnet 36 is located flush with the outer edge of the rotor yoke 34 or slightly inside the outer edge. In other words, the tip faces of both magnets 35, 36 are arranged to form a step, i.e., unevenness, in the circumferential direction. The magnets 35, 36 are resin molded using the same manufacturing method as in the first embodiment.

[0024] The magnetic sensor 24 is supported by a support member (not shown) with a slight gap from the outer edge of the rotor yoke 34. As a result, when the rotor 32 rotates, the magnetic sensor 24 is positioned so that the concave portion of the arrangement of the concave and convex end faces described above engages with the concave portion.

[0025] In this embodiment, the radial dimensions of the main magnet 35 and the auxiliary magnet 36 are made different, so that a step is provided on the outer periphery side where the magnetic sensor 24 is arranged, and no step is provided on the central axis side. Alternatively, the radial dimensions of the main magnet 35 and the auxiliary magnet 36 may be made equal, so that a step is also provided on the central axis side. As described above, according to the fifth embodiment, the present invention can also be applied to the permanent magnet motor 31 of the axial gap type.

[0026] (Other embodiments) The divided resin portion is not limited to dividing the ring into six portions, but may be divided into four portions, eight portions, or the like. The dimensions of each part may be changed as appropriate according to the individual design. Although some 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 novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0027] In the drawings, 1 indicates a split resin molded part, 2 indicates a main magnet, 3 indicates an auxiliary magnet, 4 indicates resin, 12 indicates a rotor frame, 13 indicates a rotor, 14 indicates an auxiliary magnet, and 15 and 16 indicate a split resin molded part.

Claims

1. A manufacturing method of a rotor magnet for a rotor of a permanent magnet motor including a magnet consisting of a plurality of main magnets magnetically oriented in a first direction and a plurality of auxiliary magnets magnetically oriented in a second direction different from the first direction and disposed between the main magnets, comprising: a main magnet in an unmagnetized state and an auxiliary magnet magnetized in a second direction are arranged in an arc shape that divides a circumference into a plurality of parts, and then molded with resin to generate a divided resin molded portion; A main magnet of the divided resin molded portion is magnetized in a first direction; A plurality of divided resin molded parts are connected in a circumferential shape, A manufacturing method for a rotor magnet, in which the main magnet and the auxiliary magnet are arranged so that, when combined with a stator, one end of the main magnet's face opposite the face facing the stator is engaged in a position facing a magnetic sensor whose position is fixed relative to the stator, and one end of the auxiliary magnet's face opposite the face facing the stator is not engaged in said position.

2. A manufacturing method of a rotor magnet for a rotor of a permanent magnet motor including a magnet consisting of a plurality of main magnets magnetically oriented in a first direction and a plurality of auxiliary magnets magnetically oriented in a second direction different from the first direction and disposed between the main magnets, comprising: a main magnet in an unmagnetized state and an auxiliary magnet magnetized in a second direction are arranged in an arc shape that divides a circumference into a plurality of parts, and then molded with resin to generate a divided resin molded portion; The multiple divided resin molded parts are connected in a circular shape and then assembled to the rotor frame. A main magnet of the divided resin molded portion is magnetized in a first direction; A manufacturing method for a rotor magnet, in which the main magnet and the auxiliary magnet are arranged so that, when combined with a stator, one end of the main magnet's face opposite the face facing the stator is engaged in a position facing a magnetic sensor whose position is fixed relative to the stator, and one end of the auxiliary magnet's face opposite the face facing the stator is not engaged in said position.

3. 3. The method for manufacturing a rotor magnet according to claim 1, wherein the radial thickness of the auxiliary magnet is set to be thinner than that of the main magnet.

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