Rotor, motor, and manufacturing method of rotor

Abstract

A rotor, a motor, and a method for manufacturing the rotor are provided, wherein the rotor has stable magnetic properties. The rotor of this embodiment is a rotor that rotates around a rotation axis. The rotor is disposed in a motor. The rotor is opposite to a stator. The rotor has a plurality of main magnets, a plurality of auxiliary magnets, and a holding portion. The plurality of main magnets are magnetically oriented radially. The plurality of main magnets are arranged circumferentially. The plurality of auxiliary magnets are magnetically oriented circumferentially. The plurality of auxiliary magnets are disposed between the main magnets. The holding portion is formed of resin material and embeds the main magnets and auxiliary magnets therein. A first exposed surface is provided on the surface of the main magnet. The first exposed surface is exposed from the holding portion.

Description

Technical Field

[0001] Embodiments of the present invention relate to rotors, motors, and methods for manufacturing rotors. Background Technology

[0002] It is known that motors increase drive torque by arranging rotor magnets in a Hale-Beck array. In such rotors, the positional accuracy of the magnets significantly affects the rotor's magnetic properties. However, existing technologies suffer from difficulties in improving the positional accuracy of the magnets and in stabilizing the rotor's magnetic properties.

[0003] Patent Document 1: International Publication No. 2013 / 008284 Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a rotor with stable magnetic properties, a motor, and a method for manufacturing the rotor.

[0005] The rotor of this embodiment is a rotor that rotates around a rotation axis. The rotor is mounted on a motor. The rotor is positioned opposite the stator. The rotor has multiple main magnets, multiple auxiliary magnets, and a holding portion. The multiple main magnets are magnetically oriented radially. The multiple main magnets are arranged circumferentially. The multiple auxiliary magnets are magnetically oriented circumferentially. The multiple auxiliary magnets are disposed between the main magnets. The holding portion is formed of resin material and embeds the main magnets and auxiliary magnets therein. A first exposed surface is provided on the surface of the main magnet. The first exposed surface protrudes from the holding portion.

[0006] Invention Effects

[0007] It can place the motor in a predetermined position using magnetic materials. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view of a washing machine with a motor having one embodiment.

[0009] Figure 2 This is a sectional perspective view of the rotor and stator of one embodiment.

[0010] Figure 3 This is a partial cross-sectional schematic diagram of the peripheral wall of a rotor according to one embodiment.

[0011] Figure 4 This is a schematic diagram of a rotor in one embodiment, viewed from the stator side.

[0012] Figure 5 This is a partial cross-sectional schematic diagram of a mold used to form the holding part of a rotor according to one embodiment.

[0013] Figure 6 This is a schematic diagram illustrating one embodiment of the same-pole excitation process.

[0014] Figure 7 This is a schematic diagram illustrating one embodiment of the polarity excitation process.

[0015] Explanation of reference numerals in the attached figures

[0016] 10… Mold; 10g… Gate; 16… Motor; 20… Rotor; 30… Stator; 70… Retaining part; 70g… Gate mark; 74… Second recess; 80… Main magnet; 80A… First magnetic component; 81… First opposing surface; 86… First exposed surface; 87… First embedded surface; 88… Third exposed surface; 90… Auxiliary magnet; 90A… Second magnetic component; 91… Second opposing surface; 96… Second exposed surface; 98… Fourth exposed surface; C… Circumferential; O… Rotation axis; R… Radial Detailed Implementation

[0017] Hereinafter, the rotor, motor, and rotor manufacturing method of the embodiments will be described with reference to the accompanying drawings. In the following description, structures having the same or similar functions will be labeled with the same reference numerals. Furthermore, repeated descriptions of these structures will sometimes be omitted.

[0018] Figure 1 This is a cross-sectional view of a washing machine having the motor of this embodiment.

[0019] In the following description, the side facing the washing machine, i.e., the vertically lower side, is defined as the lower side of the washing machine, and the side opposite to the facing side, i.e., the vertically upper side, is defined as the upper side of the washing machine. Furthermore, left and right are defined based on the direction from which the washing machine is viewed from the front of the user. The side closer to the user standing in front of the washing machine is defined as "front," and the side farther away is defined as "rear." In this specification, "horizontal width direction" means the left-right direction as defined above. In this specification, "depth direction" means the front-back direction as defined above. In the diagram, +X direction is the right direction, -X direction is the left direction, +Y direction is the rear direction, -Y direction is the front direction, +Z direction is the up direction, and -Z direction is the down direction.

[0020] Figure 1 This is a cross-sectional view of washing machine 1 perpendicular to the front-to-back direction.

[0021] Washing machine 1, for example, includes a frame 11, a top cover 12, a 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 the rotating tub 14 faces the vertical direction. However, washing machine 1 is not limited to the vertical axis type; it can also be a horizontal axis type, i.e., a drum type washing machine, in which the rotation axis of the rotating tub faces the horizontal direction or tilts downwards towards the rear.

[0022] The frame 11 is constructed as a single rectangular box, for example, from a steel plate. The top cover 12 is made of synthetic resin and is located on the upper part of the frame 11. The tub 13 and the spin-dry tub 14 function as a washing tub and a spin-drying tub for holding the clothes to be washed. The tub 13 and the spin-dry tub 14 are housed inside the frame 11. The tub 13 and the spin-dry tub 14 are configured as containers with open upper surfaces. Water in the tub 13 flows out from the drain outlet 131 and is drained to the outside via the drain valve 132.

[0023] Motor 16 is positioned below water tank 13. Motor 16 is connected to rotating tank 14 and impeller 15 via clutch mechanism 17. The rotation shaft O of motor 16 is aligned with the center of water tank 13.

[0024] The motor 16 in this embodiment is an external rotor type. The motor 16 has an annular stator 30 arranged around a rotation axis O, and a rotor 20 that surrounds the stator 30 radially outward. That is, the motor 16 is provided with a stator 30 and a rotor 20. The stator 30 is fixed to the frame 11 of the washing machine 1. And the rotor 20 rotates around the rotation axis O.

[0025] The rotor 20 is a bottomed cylindrical shape having a peripheral wall portion 22 and a bottom wall portion 21. The peripheral wall portion 22 is cylindrical with the rotation axis O as its center. The peripheral wall portion 22 is radially opposed to the stator 30. That is, the rotor 20 is radially opposed to the stator 30. The bottom wall portion 21 extends radially inward from the lower end of the peripheral wall portion 22. The bottom wall portion 21 is circular plate-shaped along a plane orthogonal to the rotation axis O. The rotor 20 is connected to the clutch mechanism 17 at the bottom wall portion 21.

[0026] The clutch mechanism 17 selectively transmits the rotation of the motor 16 to the rotating drum 14 and the impeller 15. During washing and rinsing, the clutch mechanism 17 transmits the driving force of the motor 16 to the impeller 15, driving the impeller 15 to rotate directly in both directions at a low speed. On the other hand, during spin-drying, the clutch mechanism 17 transmits the driving force of the motor 16 to the rotating drum 14, driving the rotating drum 14 to rotate at a high speed in one direction.

[0027] Figure 2 This is a sectional perspective view of the rotor 20 and stator 30. Additionally, in Figure 2 The illustration of the holding part 70, which will be described later, is omitted. Furthermore, in... Figure 2 The schematic map shows the shape of the magnet.

[0028] Figure 3 This is a partial cross-sectional schematic diagram of the peripheral wall portion 22 of the rotor 20. Figure 3 It is a sectional view along a section orthogonal to the axis of rotation O. The circumferential direction C, centered on the axis of rotation O, is represented as a straight line extending in the left-right direction along the paper, and the radial direction R, centered on the axis of rotation O, is represented as the up-down direction on the paper. Figure 3The upper side of the paper corresponds to the radially inner side centered on the rotation axis O. Figure 3 The lower side of the paper is radially outward from the axis of rotation O. Therefore, in Figure 3 In the middle, the stator 30 is arranged on the upper side of the rotor 20 on the paper.

[0029] In the following description, the direction in which the stator 30 is configured (in this embodiment, radially inner) relative to the rotor 20 is referred to as the stator side R1, and the direction in the radial direction opposite to the stator 30 (in this embodiment, radially outer) is referred to as the anti-stator side R2.

[0030] like Figure 2 As shown, the stator 30 includes a stator core 31, a coil 39, and an insulator (not shown). The stator core 31 has an annular outer diameter portion 32 centered on the rotation axis O, and a plurality of teeth 33 extending radially outward from the outer diameter portion 32. The plurality of teeth 33 are arranged circumferentially C. The coil 39 is constructed by winding a conductor around the teeth 33 with an insulator in between.

[0031] The rotor 20 has multiple main magnets 80, multiple auxiliary magnets 90, a frame 60, and a retaining part 70 that fixes them together. Figure 2 Omissions and references Figure 3 ).

[0032] like Figure 2 As shown, the frame 60 has a disc portion 61 and a cylindrical portion 62. The disc portion 61 is disc-shaped with the rotation axis O as its center. The disc portion 61 forms the bottom wall portion 21 of the rotor 20. The cylindrical portion 62 extends upward from the outer edge of the disc portion 61. The cylindrical portion 62 is cylindrical with the rotation axis O as its center. A plurality of main magnets 80 and a plurality of auxiliary magnets 90 are arranged circumferentially C along the inner surface of the cylindrical portion 62.

[0033] The main magnet 80 and the auxiliary magnet 90 extend cylindrically along the axial direction of the rotation axis O with the same cross-section. The upper surfaces of the main magnet 80 and the auxiliary magnet 90 are formed in a substantially coplanar plane. Similarly, the lower surfaces of the main magnet 80 and the auxiliary magnet 90 are formed in a substantially coplanar plane. The lower surfaces of the main magnet 80 and the auxiliary magnet 90 are opposite to and in contact with the upper surface of the disk portion 61 of the frame 60.

[0034] In this embodiment, the main magnet 80 and the auxiliary magnet 90 are ferrite magnets. However, the main magnet 80 and the auxiliary magnet 90 can also be other types of magnets (e.g., neodymium magnets).

[0035] like Figure 3As shown, the main magnet 80 and the auxiliary magnet 90 are alternately arranged along the circumferential direction C. The main magnet 80 and the auxiliary magnet 90 are magnetically oriented along the radial direction R and the circumferential direction C, respectively. That is, the main magnet 80 and the auxiliary magnet 90 are arranged in a Hellbeck array. Furthermore, in Figure 3 In the diagram, the arrows shown for each magnet indicate its magnetic orientation.

[0036] The main magnet 80 is a magnet with its magnetic orientation along the radial direction R. That is, the main magnet 80 uses the radial direction R as the direction of its internal magnetic flux. The magnetic poles of the multiple main magnets 80 arranged in the circumferential direction C alternately reverse their orientations. Therefore, the magnetic poles (N pole or S pole) of adjacent main magnets 80 in the circumferential direction C are different from each other.

[0037] The main magnet 80 has: a first opposing surface 81 facing the stator side R1 and opposite the stator 30; a first outer surface 82 facing the anti-stator side R2; and a pair of first circumferential end surfaces 83 facing both sides in the circumferential direction. The thickness dimension of the main magnet 80 along the radial direction R is the largest at the center in the circumferential direction and decreases towards both sides in the circumferential direction.

[0038] The first opposing surface 81 is a curved surface that protrudes radially outward from the R direction. The radius of curvature of the first opposing surface 81 in the section orthogonal to the rotation axis O is sufficiently small compared to the distance from the rotation axis O to the first opposing surface 81. The first opposing surface 81 approaches the anti-stator side R2 as it moves from the center of the circumferential C towards both sides.

[0039] The first outer surface 82 is either a flat surface or a gently curved surface at a constant distance from the rotation axis O. The first outer surface 82 is positioned opposite the cylindrical portion 62 of the frame 60 with a slight gap between them.

[0040] The first end face 83 is a flat surface. A pair of first end faces 83 extend radially R respectively. The first end faces 83 may also be inclined relative to the radial direction R in a section orthogonal to the axis of rotation O.

[0041] The auxiliary magnet 90 is a magnet magnetically oriented along the circumferential direction C. That is, the auxiliary magnet 90 uses the circumferential direction C as the direction of its internal magnetic flux. The magnetic poles of the multiple auxiliary magnets 90 arranged in the circumferential direction C alternately reverse direction. Therefore, the magnetic poles (N pole or S pole) of adjacent auxiliary magnets 90 in the circumferential direction C are different from each other.

[0042] The auxiliary magnet 90 has: a second opposing surface 91 facing the stator side R1 and opposite the stator 30; a second outer surface 92 facing the anti-stator side R2; and a pair of second circumferential end surfaces 93 facing both sides in the circumferential direction.

[0043] In a cross-section orthogonal to the rotation axis O, the auxiliary magnet 90 of this embodiment is, for example, rectangular. The thickness of the auxiliary magnet 90 along the radial direction R is smaller than the thickness of the main magnet 80 along the radial direction R. Furthermore, the dimension of the auxiliary magnet 90 along the circumferential direction C is smaller than the dimension of the main magnet 80 along the circumferential direction C.

[0044] The second opposing surface 91 is either a flat surface or a gently curved surface with a constant distance from the rotation axis O. Similarly, the second outer surface 92 is either a flat surface or a gently curved surface with a constant distance from the rotation axis O. Therefore, the thickness dimension of the auxiliary magnet 90 along the radial direction R is consistent. The second opposing surface 91 is located at a position R2 relative to the first opposing surface 81 on the anti-stator side. Furthermore, the second outer surface 92 is located at a position R1 relative to the first outer surface 82 on the stator side. The second outer surface 92 is opposed to the cylindrical portion 62 of the frame 60 with a gap.

[0045] The second end face 93 is a flat surface. A pair of second end faces 93 extend radially R respectively. The second end faces 93 can also be inclined relative to the radial direction R in a section orthogonal to the axis of rotation O.

[0046] The second end face 93 of the auxiliary magnet 90 is opposite to the first end face 83 of the main magnet 80. The second end face 93 is parallel to the first end face 83. Preferably, the second end face 93 is in contact with the first end face 83. However, a slight gap may also be provided between the second end face 93 and the first end face 83.

[0047] The retaining part 70 is made of resin material. Multiple main magnets 80 and multiple auxiliary magnets 90 are embedded in the retaining part 70. Thus, the retaining part 70 retains the multiple main magnets 80 and the multiple auxiliary magnets 90. The retaining part 70 has a stator opposing surface 71 facing the stator side R1 and opposite the stator 30.

[0048] The first opposing surface 81 of the main magnet 80 protrudes toward the stator side R1 relative to the stator opposing surface 71 of the retaining portion 70. Therefore, a portion of the first opposing surface 81 is exposed from the retaining portion 70 toward the stator side R1. The first exposed surface 86 of the main magnet 80 in the region located at the circumferential center of the first opposing surface 81 is exposed from the retaining portion 70. Furthermore, the first embedded surface (embedded surface) 87 of the main magnet 80 in the regions located at both circumferential ends of the first opposing surface 81 is embedded in the retaining portion 70. The first embedded surface 87 is located on both circumferential sides of the first exposed surface 86.

[0049] A first recess 72 is provided on the stator opposing surface 71 of the retaining part 70, exposing the second opposing surface 91 of the auxiliary magnet 90. The first recess 72 is located at the circumferential center of the second opposing surface 91. That is, a second exposed surface 96 is provided at the circumferential center of the second opposing surface 91, exposing towards the stator side R1. Furthermore, a second embedded surface 97 is provided on the second opposing surface 91 in the area other than the second exposed surface 96, into which the retaining part 70 is embedded.

[0050] According to this embodiment, a first exposed surface 86 is provided on the surface of the main magnet 80, protruding from the holding portion 70. The main magnet 80 contacts the inner surface of the mold forming the holding portion 70 at the first exposed surface 86. When multiple magnets (main magnet 80 and auxiliary magnet 90) are arranged in a Heilbeck array as in the rotor 20 of this embodiment, the positional accuracy of the main magnet 80 has a significant impact on the output performance of the motor 16. According to this embodiment, by contacting the main magnet 80 with the inner surface of the mold forming the holding portion 70, the positional accuracy of the main magnet 80 after the holding portion 70 is formed can be improved.

[0051] According to this embodiment, the first exposed surface 86 faces radially R. The main magnet 80 is positioned radially R within the mold through contact with the mold at the first exposed surface 86. The accuracy of the distance between the main magnet 80 and the stator 30 has a particularly large impact on the output performance of the motor 16. According to this embodiment, the radial distances R between the multiple main magnets 80 and the stator 30 can be made highly consistent, thereby improving the output performance of the motor 16.

[0052] According to this embodiment, the first exposed surface 86 is located on the first opposing surface 81 opposite to the stator 30. Therefore, the situation where the holding part 70 obstructs the flow of magnetic flux between the first exposed surface 86 and the stator 30 can be suppressed, and the output performance of the motor 16 can be improved.

[0053] According to this embodiment, on the first opposing surface 81 of the main magnet 80, a first embedded surface 87 for embedding the retaining portion 70 is provided on both circumferential sides of the first exposed surface 86. When the motor 16 is driven, a large force is applied to the main magnet 80 toward the stator side R1. The retaining portion 70 suppresses the movement of the main magnet 80 toward the stator side R1 at the first embedded surface 87 of the main magnet 80. According to this embodiment, the main magnet 80 is firmly held by the retaining portion 70, and the movement of the main magnet 80 toward the stator side R1 can be suppressed more reliably.

[0054] According to this embodiment, a second exposed surface 96 is provided on the surface of the auxiliary magnet 90, protruding from the holding portion 70. The auxiliary magnet 90 contacts the inner surface of the mold forming the holding portion 70 at the second exposed surface 96. According to this embodiment, by making the auxiliary magnet 90 contact the inner surface of the mold forming the holding portion 70, the positional accuracy of the auxiliary magnet 90 after the holding portion 70 is formed can be improved.

[0055] According to this embodiment, the second exposed surface 96 faces radially R. Therefore, the auxiliary magnet 90 is positioned radially R within the mold through contact with the mold at the second exposed surface 96. In a rotor 20 formed as a Heilbeck array, if the auxiliary magnet 90 is too close to the stator 30, demagnetization of the auxiliary magnet 90 during operation becomes significant. According to this embodiment, the radial distance R between the auxiliary magnet 90 and the stator 30 can be reliably separated, thus suppressing demagnetization of the auxiliary magnet 90.

[0056] According to this embodiment, a second embedded surface 97, into which the holding portion 70 is embedded, is provided on the second opposing surface 91 of the auxiliary magnet 90. Thus, the auxiliary magnet 90 is securely held by the holding portion 70, and movement of the auxiliary magnet 90 toward the stator side R1 can be more reliably suppressed.

[0057] Figure 4 This is a schematic diagram of the rotor 20 viewed from the stator side R1.

[0058] The first exposed surface 86 is provided along the entire axial length of the main magnet 80. On the other hand, the second exposed surface 96 is provided in a partial axial direction of the auxiliary magnet 90.

[0059] According to this embodiment, the first exposed surface 86 of the main magnet 80 is provided along its entire axial length. This ensures a wider area of ​​the first exposed surface 86, allowing for smoother flow of magnetic flux between the main magnet 80 and the stator 30. Consequently, the output of the motor 16 is further improved. Furthermore, the flow of magnetic flux between the main magnet 80 and the stator 30 is uniform in the axial direction. This improves the rotational efficiency of the rotor 20.

[0060] On the other hand, according to this embodiment, the second exposed surface 96 of the auxiliary magnet 90 is located only near the upper end of the second opposing surface 91. As described above, the second exposed surface 96 is exposed radially R as the bottom surface of the first recess 72 of the retaining portion 70. The first recess 72 opens on the stator side R1 and also on the upper side. The second exposed surface 96 is provided only on a portion of the second opposing surface in the axial direction, thereby ensuring that the second embedded surface 97 covered by the retaining portion 70 is wider. Therefore, the retaining force on the auxiliary magnet 90 generated by the retaining portion 70 is increased. In addition, multiple second exposed surfaces 96 may be provided on the second opposing surface 91.

[0061] like Figure 3 As shown, a plurality of second recesses 74 are provided in the holding portion 70. The plurality of second recesses 74 are arranged along the circumferential direction C. Two second recesses 74 are arranged on the anti-stator side R2 of one auxiliary magnet 90. The second recesses 74 are located near the upper ends of the main magnet 80 and the auxiliary magnet 90 and have an upper opening (see reference). Figure 4 The second recess 74 is formed from a part of the mold that shapes the retaining part 70.

[0062] A third exposed surface 88 is provided on the first peripheral end face 83 of the main magnet 80, which is exposed within the second recess 74. The third exposed surface 88 is provided on a pair of first peripheral end faces 83 of the main magnet 80. That is, a pair of third exposed surfaces 88 facing circumferentially are provided on the surface of the main magnet 80. The third exposed surface 88 is provided in the region on the anti-stator side of the first peripheral end face 83.

[0063] According to this embodiment, one main magnet 80 is exposed at a pair of third exposed surfaces 88 facing both circumferentially sides. The main magnet 80 is held from both circumferentially sides by a part of the mold within a mold that forms the holding portion 70. Therefore, the main magnet 80 and the auxiliary magnet 90 disposed between the pair of main magnets 80 can be circumferentially positioned within the mold. Consequently, the situation where multiple main magnets 80 and auxiliary magnets 90 are partially offset in the circumferential direction can be suppressed. That is, multiple circumferentially arranged main magnets 80 and auxiliary magnets 90 can be arranged at a constant interval.

[0064] A fourth exposed surface 98 is provided on the second outer surface 92 of the auxiliary magnet 90, which is exposed within the second recess 74. As described above, two second recesses 74 are provided on the anti-stator side R2 of the auxiliary magnet 90. Therefore, two fourth exposed surfaces 98 arranged in a circumferential C direction are provided on the second outer surface 92.

[0065] A fourth exposed surface 98 is provided on the second outer surface 92 of the auxiliary magnet 90, which is exposed within the second recess 74. As described above, two second recesses 74 are provided on the anti-stator side R2 of the auxiliary magnet 90. Therefore, two fourth exposed surfaces 98 arranged in a circumferential C direction are provided on the second outer surface 92.

[0066] According to this embodiment, exposed surfaces (second exposed surface 96 and fourth exposed surface 98) are provided on the surface of the auxiliary magnet 90, specifically on the two sides facing radial R (the second opposing surface 91 and the second outer surface 92). The auxiliary magnet 90 is held by a portion of the mold at the second exposed surface 96 and the fourth exposed surface 98 on both sides facing radial R. Therefore, the radial R positional accuracy of the auxiliary magnet 90 after the holding part 70 is formed can be improved more reliably.

[0067] In this embodiment, the third exposed surface and the fourth exposed surface are exposed inside the second recess 74. Therefore, the circumferential position of the main magnet 80 and the radial position of the auxiliary magnet 90 can be positioned using the second recess 74.

[0068] Next, the manufacturing method of rotor 20 will be explained.

[0069] The manufacturing method of rotor 20 includes a housing process, a resin molding process, and an excitation process. The housing process, the resin molding process, and the excitation process are performed in sequence.

[0070] The following is a detailed explanation of each process.

[0071] Figure 5 This is a partial cross-sectional schematic diagram of the mold 10 that forms the retaining part 70 of the rotor 20.

[0072] Mold 10 has, for example, a male mold and a female mold that can approach and separate from each other axially. A receiving frame 60, a first magnetic component 80A, a second magnetic component 90A, and a void G filled with molten resin are provided at the mating portion of the male and female molds. The void G is an annular space extending circumferentially along the rotation axis O.

[0073] During the housing process, the operator houses the frame 60, the first magnetic component 80A, and the second magnetic component 90A within the gap G in the mold 10. The first magnetic component 80A is an unmagnetized main magnet 80. Similarly, the second magnetic component 90A is an unmagnetized auxiliary magnet 90. The first magnetic component 80A and the second magnetic component 90A are arranged alternately in a ring shape around the rotation axis O in the circumferential direction of the gap G.

[0074] A first mold surface 8 and a second mold surface 9, separated by a gap G and radially opposed to each other, are provided on the inner surface of the mold 10. The first mold surface 8 faces the anti-stator side R2. The second mold surface 9 faces the stator side R1. The first mold surface 8 and the second mold surface 9 are both cylindrical surfaces centered on the rotation axis O. The second mold surface 9 contacts the cylindrical portion 62 of the frame 60. Thus, the frame 60 is positioned within the mold 10.

[0075] The first mold surface 8 has multiple mold recesses 8a and multiple first mold protrusions 8b. The mold recesses 8a and the first mold protrusions 8b are arranged alternately along the circumferential direction C. The mold recesses 8a open toward the anti-stator side R2. The front end face of the first mold protrusion 8b is a flat surface facing the anti-stator side R2.

[0076] Inside the mold 10, the first magnetic component 80A contacts the inner surface of the mold recess 8a. Furthermore, inside the mold 10, the second magnetic component 90A contacts the front end face of the first mold protrusion 8b.

[0077] In addition, the mold recess 8a is provided along the entire axial length of the gap G, and the first mold protrusion 8b is provided at the upper end of the gap G.

[0078] At the upper end of the gap portion G, a plurality of second mold protrusions 8c are provided, protruding downwards from the inner side surface of the mold 10. The plurality of second mold protrusions 8c are arranged circumferentially along the rotation axis O. The second mold protrusions 8c are located on the anti-stator side R2 of the second magnetic component 90A. Furthermore, the second mold protrusions 8c are located on the stator side R1 of the cylindrical portion 62 of the frame 60.

[0079] The first magnetic component 80A is held from both sides of the circumferential direction C by a pair of second mold protrusions 8c. Thus, the first magnetic component 80A is positioned in the circumferential direction C within the mold 10.

[0080] The second magnetic component 90A is held radially between the first mold protrusion 8b and a pair of second mold protrusions 8c. Thus, the second magnetic component 90A is positioned radially within the mold 10.

[0081] The resin molding process involves filling the mold 10 with molten resin to mold the first magnetic component 80A and the second magnetic component 90A. After the molten resin has solidified, the operator removes the molded rotor 20 from the mold 10.

[0082] The mold 10 is provided with a gate 10g for filling the void G with molten resin. The gate 10g is located at the upper end of the void G and opens inside the void G. The gate 10g is configured in the void G biased towards the anti-stator side R2.

[0083] According to this embodiment, the gate 10g is positioned biased towards the anti-stator side R2, thereby allowing molten resin injected from the gate 10g toward the void G to preferentially enter the region of the void G on the anti-stator side R2. The first magnetic component 80A and the second magnetic component 90A are pressed toward the stator side R1 by the injection pressure of the molten resin. That is, in the resin molding process, the first magnetic component 80A and the second magnetic component 90A are pressed against the radially R-oriented surface of the mold 10. As a result, the first magnetic component 80A and the second magnetic component 90A are positioned with high precision relative to the first mold surface 8 of the mold 10.

[0084] like Figure 3As shown, a gate mark 70g is formed on the portion of the holding part 70 corresponding to the gate 10g. The gate mark 70g is positioned relative to the center of the radial direction R of the holding part 70, biased toward the anti-stator side R2 (the opposite side of the stator).

[0085] The excitation process is the process of energizing the first magnetic component 80A and the second magnetic component 90A. The excitation process includes same-pole excitation processes and opposite-pole excitation processes.

[0086] Figure 6 This is a schematic diagram illustrating the same-pole excitation process. Furthermore, Figure 7 This is a schematic diagram illustrating the excitation process of opposite poles.

[0087] The same-pole excitation process is a process of energizing the second magnetic component 90A to make its magnetic orientation circumferential C. The second magnetic component 90A is energized through the same-pole excitation process and becomes a permanent magnet (auxiliary magnet 90).

[0088] The opposite-pole excitation process is a process of energizing the first magnetic component 80A to make its magnetic orientation radial R. The first magnetic component 80A is energized through the opposite-pole excitation process and becomes a permanent magnet (main magnet 80).

[0089] The same-pole excitation process and the opposite-pole excitation process are performed by the excitation device 4. The excitation device 4 has four excitation yokes (first excitation yoke 40A, second excitation yoke 40B, third excitation yoke 40C, and fourth excitation yoke 40D). The four excitation yokes are connected to an excitation power supply (not shown). In this embodiment, the excitation device uses four excitation yokes. However, the excitation device may also have a number of excitation yokes capable of simultaneously exciting all the first magnetic components 80A and all the second magnetic components 90A.

[0090] The first excitation yoke 40A and the second excitation yoke 40B are arranged opposite each other in the radial direction R. The first excitation yoke 40A and the second excitation yoke 40B are arranged on both sides of the thickness direction of a first magnetic component 80A. The first excitation yoke 40A is arranged on the outer side in the radial direction R, and the second excitation yoke 40B is arranged on the inner side in the radial direction R.

[0091] The third excitation yoke 40C and the fourth excitation yoke 40D are arranged opposite each other in the radial direction R. The third excitation yoke 40C and the fourth excitation yoke 40D are arranged on both sides of the thickness direction of the adjacent first magnetic component 80A held by the first excitation yoke 40A and the second excitation yoke 40B. The third excitation yoke 40C is arranged on the outer side in the radial direction R, and the fourth excitation yoke 40D is arranged on the inner side in the radial direction R.

[0092] like Figure 6As shown, in the same-pole excitation process, the opposing first excitation yoke 40A and second excitation yoke 40B generate magnetic fields with the same pole. Furthermore, the opposing third excitation yoke 40C and fourth excitation yoke 40D generate magnetic fields with the same pole. At this time, the magnetic fields generated by the third excitation yoke 40C and fourth excitation yoke 40D are opposite poles to the magnetic fields generated by the first excitation yoke 40A and second excitation yoke 40B. Through the same-pole excitation process, the second magnetic component 90A is energized along the circumferential direction C. Alternatively, when the second magnetic component 90A is energized in the opposite direction along the circumferential direction C, it is sufficient that the magnetic fields generated by the four excitation yokes 40A, 40B, 40C, and 40D have magnetic poles opposite to those described above.

[0093] like Figure 7 As shown, in the opposite-pole excitation process, opposing first excitation yokes 40A and second excitation yokes 40B generate opposite-pole magnetic fields, thereby energizing the clamped first magnetic component 80A in one direction (opposite excitation). Simultaneously, opposing third excitation yokes 40C and fourth excitation yokes 40D generate opposite-pole magnetic fields, thereby energizing the clamped first magnetic component 80A in the other direction (opposite excitation). At this time, the orientation of the magnetic field between the third excitation yokes 40C and the fourth excitation yokes 40D is opposite to the orientation of the magnetic field between the first excitation yokes 40A and the second excitation yokes 40B. In the opposite-pole excitation process, all first magnetic components 80A are sequentially energized.

[0094] In the excitation process, the same-pole excitation process and the opposite-pole excitation process are performed alternately and repeatedly in sequence. After the excitation process is completed, the rotor 20 is finished. The manufactured rotor 20 is then combined with the separately manufactured stator 30.

[0095] According to the manufacturing method of the rotor 20 in this embodiment, neither the first magnetic component 80A nor the second magnetic component 90A is energized during the magnet housing process. Therefore, during the housing process, the first magnetic component 80A and the second magnetic component 90A can be arranged close to each other.

[0096] According to this embodiment, the main magnet 80 and the auxiliary magnet 90 are fixed by the holding part 70 during the resin molding process. The holding part 70 prevents the main magnet 80 and the auxiliary magnet 90 from repelling each other and separating. Therefore, the degree of freedom in the arrangement of the main magnet 80 and the auxiliary magnet 90 can be increased. In this embodiment, the main magnet 80 and the auxiliary magnet 90 are arranged with a high density. As a result, the magnetic force of the rotor 20 is increased, and the torque of the motor 16 is increased.

[0097] According to the rotor 20 manufacturing method of this embodiment, the excitation of the main magnet 80 is performed by opposing excitation. Therefore, the generation of leakage flux in the excitation process (opposite pole excitation process) of the main magnet 80 can be suppressed, and the excitation rate of the main magnet 80 can be improved. Furthermore, according to the rotor 20 manufacturing method of this embodiment, the opposite pole excitation process is performed after the same pole excitation process. Therefore, the demagnetization of the main magnet 80 in the excitation process of the auxiliary magnet 90 can be suppressed.

[0098] In this embodiment, the external rotor type motor 16 has been described. However, the above structure can also be used for internal rotor type motors.

[0099] Several embodiments of the present invention have been described, but these embodiments are merely illustrative examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in a wide variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above embodiments and their variations are included in the scope and spirit of the invention, and are also included in the scope of the invention described in the technical solutions and its equivalents.

Claims

1. A rotor, disposed in a motor, opposite to the stator and rotating about a rotation axis, comprising: Multiple main magnets that are magnetically oriented radially and arranged circumferentially; Multiple auxiliary magnets are magnetically oriented along the circumferential direction and arranged between the main magnets; as well as A retaining part formed of resin material, into which the main magnet and the auxiliary magnet are embedded. A first exposed surface is provided on the surface of the main magnet, which protrudes from the holding part. The auxiliary magnet is located on the opposite side of the stator compared to the first exposed surface. A second exposed surface is provided on the surface of the auxiliary magnet, which protrudes from the holding part. The second exposed surface is partially disposed on the auxiliary magnet. The main magnet has a pair of third exposed surfaces facing both sides in the circumferential direction. A fourth exposed surface is provided on the surface of the aforementioned auxiliary magnet. A recess is provided in the aforementioned retaining part. The aforementioned third exposed surface and the aforementioned fourth exposed surface are exposed inside the aforementioned recess.

2. The rotor according to claim 1, wherein, The first exposed surface mentioned above faces radially.

3. The rotor according to claim 1 or 2, wherein, The aforementioned main magnet has a first opposing surface that is opposite to the aforementioned stator. The first exposed surface is located on the first opposing surface.

4. The rotor according to claim 3, wherein, The aforementioned retaining section has gate marks. The aforementioned gate marks are positioned off-center from the radial center of the aforementioned retaining portion, on the opposite side of the aforementioned stator.

5. The rotor according to claim 3, wherein, In the first opposing surface, there are embedding surfaces for embedding the retaining part on both sides of the first exposed surface.

6. The rotor according to claim 3, wherein, The first exposed surface is provided along the entire axial length of the main magnet.

7. The rotor according to claim 1, wherein, The aforementioned auxiliary magnet has a second opposing surface opposite to the aforementioned stator. The aforementioned second exposed surface is only provided on a portion of the aforementioned second opposing surface.

8. The rotor according to claim 1, wherein, The auxiliary magnet has exposed surfaces on its radially facing sides.

9. A motor, comprising: The rotor according to any one of claims 1 to 8; and The aforementioned stator.

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