Rotor and method of manufacturing a rotor

Abstract

Provided is a rotor and a manufacturing method of the rotor, which can position a plurality of magnets with high precision. The manufacturing method of the rotor includes a magnet arrangement step, a resin molding step, and a post-excitation step. In the magnet arrangement step, a plurality of unexcited main magnets having first inclined surfaces are arranged in a circular ring shape or a circular arc shape at a circumferential interval in such a manner that a circumferential surface of a mold arranged on a stator side opposes a side surface of the main magnets, a first normal line of the first inclined surfaces faces an opposite side of the stator side in a radial direction, and the first normal line is inclined with respect to a rotation axis. In the resin molding step, molten resin is directly or indirectly pressed into the main magnets from above the main magnets with respect to the first inclined surfaces via the mold, and the main magnets are molded with the resin. In the post-excitation step, the main magnets after resin molding are excited.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to a rotor and a manufacturing method of a rotor. BACKGROUND

[0002] A motor of a washing machine in which a plurality of magnets are arranged in a circumferential direction is described in Patent Literature 1. As such a motor of a washing machine, it is preferable to be small in size and high in torque.

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 10-42526 SUMMARY

[0004] An object of the present application is to provide a rotor in which positioning of a plurality of magnets is performed with high accuracy and a manufacturing method of a rotor.

[0005] The manufacturing method of the rotor of the embodiment has a magnet arrangement step, a resin molding step, and a post-excitation step. In the magnet arrangement step, a plurality of main magnets that are not excited, which have first inclined surfaces, are arranged in a circular ring shape or a circular arc shape at intervals in the circumferential direction in such a manner that a circumferential surface of a mold arranged on the stator side opposes a side surface of the main magnets and a first normal line of the first inclined surfaces is inclined in the radial direction toward the opposite side of the stator side and with respect to the rotational axis. In the resin molding step, molten resin is pressed into the main magnets directly or indirectly with respect to the first inclined surfaces from above the main magnets via the mold, and thus the main magnets are molded with the resin. In the post-excitation step, the main magnets after resin molding are excited.

[0006] EFFECT OF THE INVENTION

[0007] It is possible to arrange a motor magnet material at a predetermined position. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a cross-sectional view of a washing machine taken in a direction perpendicular to a front-rear direction.

[0009] Figure 2 is a perspective view of a rotor to which the embodiment relates.

[0010] Figure 3 is a perspective view in which a part of a rotor and a stator are enlarged.

[0011] Figure 4 is a plan view of an outer peripheral portion of the rotor viewed from a lower side of the rotor shown in Figure 2

[0012] Figure 5 is a cross-sectional view of the rotor taken in an A1-A2 line direction of the rotor shown in Figure 4

[0013] is a cross-sectional view of the rotor taken in an A1-A2 line direction of the rotor shown in​Figure 6 is Figure 4 is a cross-sectional view of the rotor shown in FIG. 1 in the B1-B2 line direction.

[0014] Figure 7 is a view of the rotor magnet shown in FIG. 1 as viewed from the opposite side (the peripheral wall portion side). Figure 4 is a view of the rotor magnet shown in FIG. 1 as viewed from the opposite side (the peripheral wall portion side).

[0015] Figure 8 is a view showing a flow of a manufacturing method of a rotor according to an embodiment.

[0016] Figure 9 is a plan view of a plurality of first and auxiliary magnets arranged in a mold.

[0017] Figure 10 is a cross-sectional view of the rotor shown in FIG. 1 in the C1-C2 line direction. Figure 9

[0018] Figure 11 is a cross-sectional view of the rotor shown in FIG. 1 in the D1-D2 line direction. Figure 9

[0019] Figure 12 is a cross-sectional view of the rotor shown in FIG. 1 after the mold is filled with resin (1).

[0020] Figure 13 is a cross-sectional view of the rotor shown in FIG. 1 after the mold is filled with resin (2).

[0021] Figure 14 is a plan view of the rotor magnet shown in FIG. 1 after molding with resin.

[0022] Figure 15 is a perspective view of the rotor when the rotor magnet is excited.

[0023] Figure 16 is a schematic view of a part of the excitation magnet yoke and the rotor magnet in the same-pole excitation process as viewed from above.

[0024] Figure 17 is a schematic view of a part of the excitation magnet yoke and the rotor magnet in the opposite-pole excitation process as viewed from above.

[0025] Figure 18 is a schematic view of a part of the excitation magnet yoke and the rotor magnet after the opposite-pole excitation process as viewed from above.

[0026] Figure 19 is a cross-sectional view of the main magnet of a modification.

[0027] Explanation of Reference Numerals

[0028] ​​1 … washing machine, 11 … frame, 12 … top cover, 13 … tub, 14 … rotary tub, 15 … pulsator, 16 … motor, 17 … shaft, 18 … drain, 19 … drain valve, 20 … rotor, 22 … peripheral wall portion, 23 … rotor magnet, 24 … resin, 25, 25A, 25B, 45 … main magnet, 25a, 25b, 26a, 26b … end face, 25c … side face, 25d … first inclined face, 25e … inclined face, 26, 26C … auxiliary magnet, 26c … second inclined face, 30 … stator, 30a … stator core, 30b … pole tooth, 30c … stator coil, 35 … mold, 35A … resin introduction hole, 36 … side wall, 36a … peripheral face, 40A … first excitation yoke, 40B … second excitation yoke, 40C … third excitation yoke, 40D … fourth excitation yoke, 45A … end portion, H1, H2 … height, N1 … first normal line, N2 … second normal line, O … rotation axis, R1 … stator side, R2 … opposite side DETAILED DESCRIPTION

[0029] Hereinafter, a rotor of a washing machine and a manufacturing method of a drum of an embodiment will be described with reference to the drawings. In the following description, the same reference numerals are attached to structures having the same or similar functions. Further, the repeated description of these structures is sometimes omitted.

[0030] In the present specification, the side of a washing machine on which a setting surface is provided, i.e., the vertically lower side, is defined as the lower side of the washing machine, and the side opposite to the setting surface, i.e., the vertically upper side, is defined as the upper side of the washing machine. Also, 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. Also, the side closer to the user standing in front of the washing machine is defined as "front", and the side farther from the user is defined as "rear".

[0031] In the present specification, "lateral width direction" means the left-right direction in the above definition. In the present specification, "depth direction" means the front-rear direction in the above definition. 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 upper direction, and the -Z direction is the lower direction.

[0032] Reference Figures 1 to 7 The rotor 20 of the washing machine 1 of the present embodiment and the manufacturing method of the rotor 20 will be described in order. First, reference will be made to Figure 1 The overall structure of the washing machine 1 will be described. However, the washing machine 1 or the rotor 20 does not necessarily have all of the structures described below, and some of the structures can be appropriately omitted.

[0033] Figure 1 is a cross-sectional view of the washing machine 1 taken in a direction perpendicular to the front-rear direction.

[0034] The washing machine 1 includes a cabinet 11, a top cover 12, a tub 13, a rotary tub 14, a pulsator 15, and a motor 16. The washing machine 1 is a so-called vertical axis type washing machine in which a rotation axis O of the rotary tub 14 is oriented in a vertical direction. Note that the washing machine 1 is not limited to the vertical axis type, and can be a so-called drum type washing machine in which the rotation axis of the rotary tub is horizontal or inclined downward toward the rear.

[0035] The cabinet 11 is formed in a rectangular box shape as a whole, for example, from a steel plate. The top cover 12 is made of synthetic resin, for example, and is provided at an upper portion of the cabinet 11. The tub 13 and the rotary tub 14 function as a washing tub and a dehydration tub that house laundry that is a subject of washing. The tub 13 and the rotary tub 14 are provided inside the cabinet 11. The tub 13 and the rotary tub 14 are formed in a container shape with an upper surface open. Water in the tub 13 flows out from a drain 18 and is drained to the outside via a drain valve 19.

[0036] The motor 16 has a flat cylindrical appearance with a smaller diameter than the tub 13, and is assembled at a lower side of the tub 13 with the rotation axis O passing through the center thereof.

[0037] 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 (rotating member), and a stator 30 (fixed member). The motor 16 is an external rotor type induction motor in which the rotor 20 is disposed outside the stator 30. With respect to the rotor 20, the stator 30 generates a rotating magnetic field by causing an alternating current to flow through a stator coil 30c, and the rotor 20 rotates as a result. The shaft 17 is coupled to the rotor 20 and rotates in correspondence with the rotation of the rotor 20. The rotation axis of the shaft 17 coincides with the rotation axis O.

[0038] The shaft 17 is connected to the rotary 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 rotary tub 14 and the pulsator 15. The motor 16 and the clutch mechanism transmit the driving force of the motor 16 to the pulsator 15 to directly drive the pulsator 15 at a low speed in the forward and reverse directions while stopping the rotation of the rotary tub 14 at the time of washing and the time of rinsing. On the other hand, the motor 16 and the clutch mechanism transmit the driving force of the motor 16 to the rotary tub 14 to rotate and drive the rotary tub 14 and the pulsator 15 at a high speed in one direction at the time of dehydration and the like.

[0039] The rotor 20 is a flat, bottomed cylindrical component. The rotor 20 includes: a circular plate-shaped bottom wall portion 21 with a central opening; a cylindrical peripheral wall portion 22 (frame) erected around 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 function as a back yoke and are formed by stamping iron plates. Multiple slits 21a for heat dissipation are formed in the bottom wall portion 21.

[0040] The rotor magnet 23 is fixed to the inner side 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 auxiliary magnets 26 are alternately arranged in the circumferential direction C. The length of the circumferential direction C of the main magnets 25 is longer than the length of the circumferential direction C of the auxiliary magnets 26. The main magnets 25 and the auxiliary magnets 26 are molded from resin 24.

[0041] The rotor magnet 23 is, for example, a Hellbeck array magnet in which the main magnet 25 and the auxiliary magnet 26 are arranged in a Hellbeck array.

[0042] Ferrite magnets are preferred for use as the main magnet 25 and the auxiliary magnet 26, for example, from the viewpoint of excitation. Other magnets, such as neodymium magnets, can also be used as the main magnet 25 and the auxiliary magnet 26.

[0043] Figure 4 From Figure 2 The diagram shows a plan view of the outer periphery of rotor 20 viewed from its lower side. Figure 4 For ease of explanation, the illustrations of the resin 24 formed on end face 25b, end face 26b, first inclined surface 25d, and second inclined surface 26c are omitted. Figure 5 yes Figure 4 A cross-sectional view of rotor 20 along line A1-A2. Figure 5 The vertical direction relative to Figure 2 or Figure 3 The top and bottom directions are reversed.

[0044] The main magnet 25 is formed in a columnar shape and extends in the vertical direction. The main magnet 25 is as follows: Figure 5 The diagram shows an end face 25a, an end face 25b disposed on the opposite side of the end face 25a, a side face 25c, and a first inclined surface 25d.

[0045] End faces 25a and 25b are planes that are approximately orthogonal to the vertical direction. End face 25a is disposed on the upper side (+Z side). End face 25b is disposed on the lower side (-Z side). Side face 25c is disposed on the stator side R1 (stator 30 side). At least a portion of side face 25c is exposed from the resin 24. Side face 25c on the stator side R1 is not entirely covered by the resin 24, thus suppressing the reduction of the magnetic force of the main magnet 25 due to resin molding.

[0046] The first inclined surface 25d is disposed on the opposite side R2 of the stator side R1 (in this embodiment, the peripheral wall 22 side) and is connected to the end face 25b. The first inclined surface 25d is inclined relative to the end face 25b. The first normal N1 of the first inclined surface 25d is radially R toward the opposite side R2 of the stator side R1 and is inclined relative to the rotation axis O. In addition, the first inclined surface 25d can be, for example, a plane or a curved surface.

[0047] exist Figure 2 In the rotor 20 shown, the first inclined surface 25d and the end face 25b are disposed on the lower side (-Z side).

[0048] Figure 6 yes Figure 4 A cross-sectional view of rotor 20 along line B1-B2.

[0049] The auxiliary magnet 26 is cylindrical and extends vertically. The auxiliary magnet 26 has an end face 26a, an end face 26b disposed on the opposite side of the end face 26a, and a second inclined surface 26c.

[0050] End faces 26a and 26b are planes that are approximately orthogonal to the vertical direction. End face 26a is located on the upper side (+Z side). End face 26b is located on the lower side (-Z side). End face 26a is configured to be approximately coplanar with end face 25a of the main magnet 25.

[0051] The second inclined surface 26c is disposed on the stator side R1 and connected to the end face 26b. The second inclined surface 26c is inclined relative to the end face 26b. The second normal N2 of the second inclined surface 26c is radially R toward the stator side R1 and inclined relative to the rotation axis O. In addition, the second inclined surface 26c can be, for example, a plane or a curved surface.

[0052] The main magnet 25 and the auxiliary magnet 26, which are adjacent to each other, are preferably in contact at least partially. This allows the main magnet 25 and the auxiliary magnet 26 to be arranged closely in the circumferential direction C.

[0053] The main magnet 25 is preferably shaped to suppress the auxiliary magnet 26 from moving toward the opposite side R2 when in contact with it. The shapes of the main magnet 25 and the auxiliary magnet 26 are, for example, as shown below. Figure 4 The shape shown is trapezoidal (e.g., isosceles trapezoid) in a plan view viewed from above. In this plan view, the upper base of the main magnet 25 is positioned on the stator side R1, and the upper base of the auxiliary magnet 26 is positioned on the opposite side R2. That is, the upper bases of the main magnet 25 and the auxiliary magnet 26 are at different positions in the radial direction R. By forming this shape, when positioning the main magnet 25 and the auxiliary magnet 26, the positioning of the auxiliary magnet 26 can be restricted by bringing the main magnet 25 and the auxiliary magnet 26 into contact.

[0054] Figure 7 Observed from the opposite side R2 only Figure 4 The diagram shows the rotor magnet 23.

[0055] The height H2 of the auxiliary magnet 26 is preferably lower than the height H1 of the main magnet 25. That is, the first inclined surface 25d is preferably positioned to protrude axially from the rotation axis O compared to the second inclined surface 26c. As a result, in the resin molding process described later, the molten resin is more likely to reach the first inclined surface 25d before the second inclined surface 26c.

[0056] The resin 24 is fixed to the inner circumferential surface of the peripheral wall portion 22 in a resin-molded state for the main magnet 25 and the auxiliary magnet 26. That is, the rotor magnet 23 is fixed to the peripheral wall portion 22 via the resin 24.

[0057] The stator 30 (fixed member) has: an annular stator core 30a with an outer diameter smaller than the inner diameter of the rotor 20, magnetic pole teeth 30b extending outward from the outer periphery of the stator core 30a, and stator coils 30c wound around the magnetic pole teeth 30b.

[0058] Secondly, refer to Figures 8 to 19 The manufacturing method of rotor 20 will be explained. Figure 8 This is a flowchart illustrating the manufacturing method of rotor 20. Figure 9 This is a view of the upper surface of the main magnet 25 and the auxiliary magnet 26 disposed within the mold 35. Figure 9 For ease of explanation, the upper side of mold 35 is omitted from the illustration. Figure 10 yes Figure 9 A cross-sectional view of the structure shown along line C1-C2. Figure 11 yes Figure 9 A cross-sectional view of the structure shown along line D1-D2.

[0059] First, in the magnet arrangement process S1, the unenergized main magnet 25 and the unenergized auxiliary magnet 26 are alternately arranged in a ring shape within the mold 35 (see reference). Figures 9 to 11 During the manufacture of rotor 20, the end face 25b of main magnet 25 and the end face 26b of auxiliary magnet 26 are positioned vertically upwards. That is, the vertical orientation is opposite in rotor 20 installed in washing machine 1 and rotor 20 during manufacture.

[0060] The mold 35 has an annular internal cavity that allows resin to be pressed in. For example... Figure 9As shown, a plurality of resin introduction holes 35A for pressing the molten resin into the mold 35 are formed at intervals in the circumferential direction C on the upper side of the mold 35. The inside hollow of the mold 35 is divided on the opposite side R2 in the radial direction R by the peripheral wall portion 22. Alternatively, a mold can be used instead of the peripheral wall portion 22.

[0061] The main magnet 25 is arranged such that a first normal line Nl of the first inclined surface 25d is inclined toward the opposite side R2 in the radial direction R and relative to the rotation axis O, and the first inclined surface 25d is inclined upward. Also, the main magnet 25 is arranged such that the side surface 25c faces the peripheral surface 36a of the mold 35.

[0062] On the other hand, the auxiliary magnet 26 is arranged such that a second normal line N2 of the second inclined surface 26c is inclined toward the stator side Rl in the radial direction R and relative to the rotation axis O, and is inclined upward. At this stage, the main magnet 25 and the auxiliary magnet 26 are not yet energized, and thus can be arranged close to each other in the circumferential direction C.

[0063] Figure 12 and Figure 13 is a sectional view after the inside of the mold 35 is filled with the resin 24. Figure 14 is a plan view of the upper surface of the rotor magnet 23 after molding by the resin 24. In Figure 14 , the illustration of the resin 24 formed on the upper side of the mold 35, the main magnet 25, and the auxiliary magnet 26 is omitted for convenience of explanation.

[0064] Next, in the resin molding step S2, the molten resin is pressed into the mold 35 via the resin introduction holes 35A, and thus the rotor magnet 23 is resin-molded with the resin 24 (see Figures 12 to 14 ). The resin introduction holes 35A are formed above the first inclined surface 25d and the second inclined surface 26c, and thus the molten resin is easily supplied directly to the first inclined surface 25d and the second inclined surface 26c.

[0065] The height Hl of the main magnet 25 is higher than the height H2 of the auxiliary magnet 26, and thus the molten resin easily reaches the first inclined surface 25d before the second inclined surface 26c. Further, if the molten resin reaches the first inclined surface 25d, the main magnet 25 is moved toward the stator side Rl (E side) in the direction along the first normal line Nl and under force, and the side surface 25c contacts the peripheral surface 36a, and thus the positioning of the main magnet 25 is completed.

[0066] Next, the molten resin also reaches the second inclined surface 26c. If the molten resin reaches the second inclined surface 26c, the auxiliary magnet 26 is moved toward the opposite side R2 (F side) in the direction along the second normal line N2 and under force, and the positioning of the auxiliary magnet 26 is completed.

[0067] As shown in FIG. 1, the main magnet 25 and the auxiliary magnet 26 have a trapezoidal shape in a plan view observed from the upper and lower directions. On the circumferential direction C, the main magnet 25 and the auxiliary magnet 26 that are adjacent to each other are in contact, and thus the positioning of the auxiliary magnet 26 is limited to some extent. Figure 4

[0068] As shown in FIG. 1, the height H1 of the main magnet 25 is higher than the height H2 of the auxiliary magnet 26, and thus the molten resin is likely to reach the first inclined surface 25d before the second inclined surface 26c. Therefore, even in a case where the resin 24 is simultaneously pressed into the mold 35 from the plurality of resin introduction holes 35A, the main magnet 25 can be preferentially positioned. Figure 7

[0069] By moving the main magnet 25 before the auxiliary magnet 26, it is possible to suppress the molten resin from entering between the circumferential surface 36a of the mold 35 and the side surface 25c of the main magnet 25. As a result, at least a part of the side surface 25c of the stator side R1 can be exposed from the resin 24 after the resin molding process. The side surface 25c of the stator side R1 is not entirely covered with the resin 24, and thus it is possible to suppress the reduction in the magnetic force of the main magnet 25 due to resin molding.

[0070] In the mold removal process S3, the rotor magnet 23 fixed to the circumferential wall portion 22 via the resin 24 is taken out from the mold 35 at a stage where the resin 24 in the mold 35 is hardened. Alternatively, the rotor magnet 23 can be formed in a circular ring shape by combining components that are divided into circular arc shapes and subjected to resin molding.

[0071] Figure 15 FIG. 10 is a perspective view of the rotor 20 when the rotor magnet 23 is excited.

[0072] In the post-excitation process S4, the rotor magnet 23 is inserted into an excitation device (not shown), and the main magnet 25 and the auxiliary magnet 26 are excited. The post-excitation process has a same-pole excitation process and an opposite-pole excitation process.

[0073] As the main magnet 25 and the auxiliary magnet 26, ferrite magnets are used, for example, and thus excitation can be appropriately performed in the post-excitation process compared to a case where neodymium magnets are used.

[0074] The excitation device has four excitation yokes (a first excitation yoke 40A, a second excitation yoke 40B, a third excitation yoke 40C, and a fourth excitation yoke 40D). The four excitation yokes are connected to an excitation power source (not shown). Alternatively, the excitation device can have an excitation yoke of a number that enables simultaneous excitation of all the main magnets 25 and the auxiliary magnets 26.

[0075] ​​The first excitation yoke 40A and the second excitation yoke 40B are disposed in opposition to each other and on both sides in the plate thickness direction (radial direction R) of one of the main magnets 25. The first excitation yoke 40A is disposed on the outer side in the radial direction R, and the second excitation yoke 40B is disposed on the inner side in the radial direction R. In the heteropolar excitation process described later, by causing the first excitation yoke 40A and the second excitation yoke 40B disposed in opposition to each other to generate magnetic fields of opposite polarities, the main magnet 25 held therebetween is excited in one direction (opposite excitation).

[0076] The third excitation yoke 40C and the fourth excitation yoke 40D are disposed in opposition to each other. The third excitation yoke 40C and the fourth excitation yoke 40D are disposed on both sides in the plate thickness direction (radial direction R) of the adjacent main magnet 25 to the main magnet 25 held between the first excitation yoke 40A and the second excitation yoke 40B. The third excitation yoke 40C is disposed on the outer side in the radial direction R, and the fourth excitation yoke 40D is disposed on the inner side in the radial direction R. In the heteropolar excitation process described later, by causing the third excitation yoke 40C and the fourth excitation yoke 40D disposed in opposition to each other to generate magnetic fields of opposite polarities, the main magnet 25 held therebetween is excited in one direction (opposite excitation).

[0077] In the following description, the unexcited main magnet 25 held between the first excitation yoke 40A and the second excitation yoke 40B is referred to as "main magnet 25A", and the unexcited main magnet 25 held between the third excitation yoke 40C and the fourth excitation yoke 40D is referred to as "main magnet 25B". The unexcited auxiliary magnet 26 adjacent to the main magnet 25A and the main magnet 25B in the circumferential direction C is referred to as "auxiliary magnet 26C".

[0078] Figure 16 is a schematic view of a portion of the excitation yokes and the rotor magnet 23 in the homopolar excitation process, viewed from above.

[0079] As shown in Figure 16 , the first excitation yoke 40A and the second excitation yoke 40B disposed in opposition to each other are caused to generate magnetic fields of the same polarity. Also, the third excitation yoke 40C and the fourth excitation yoke 40D disposed in opposition to each other are caused to generate magnetic fields of the same polarity. Here, the magnetic fields generated by the third excitation yoke 40C and the fourth excitation yoke 40D are of opposite polarity to the magnetic fields generated by the first excitation yoke 40A and the second excitation yoke 40B. By the homopolar excitation process, the auxiliary magnet 26C is excited in the circumferential direction C.

[0080] Figure 17 is a schematic view of a portion of the excitation yokes 40 and the rotor magnet 23 in the heteropolar excitation process, viewed from above.

[0081] Next, as shown in Figure 17As shown, the first and second excitation yokes 40A and 40B, which are opposed to each other, are caused to generate magnetic fields of opposite poles (opposite-pole excitation process). Here, the magnetic field generated at the fourth excitation yoke 40D and the magnetic field generated at the second excitation yoke 40B are of opposite poles. By the opposite-pole excitation process, the main magnet 25A is excited in the radial direction R. Also, the main magnet 25B is excited in the radial direction R. The magnetic orientations of the main magnet 25A and the main magnet 25B, which are excited by the same-pole excitation process, are directed in opposite directions in the radial direction R.

[0082] Figure 18 FIG. 6 is a schematic view of a portion of the excitation yoke 40 and the rotor magnet 23 after the opposite-pole excitation process, as viewed from above. As shown, the magnetic orientations of the main magnet 25A and the main magnet 25B, which are excited by the same-pole excitation process, are directed in opposite directions in the radial direction R. Also, the magnetic orientation of the auxiliary magnet 26C is directed in the circumferential direction C. Figure 18

[0083] Then, the same-pole excitation process and the opposite-pole excitation process are repeated to excite the remaining main magnets 25 and auxiliary magnets 26, and the rotor magnet 23 is formed as a known Halbach array magnet. Then, the rotor magnet 23 after the completion of the subsequent excitation process is combined with the bottom wall portion 21 and the peripheral wall portion 22, and thereby the rotor 20 is completed.

[0084] According to the manufacturing method of the rotor 20 according to the present embodiment, the molten resin is directly or indirectly supplied toward the plurality of first inclined surfaces 25d to move the plurality of main magnets 25, and the side surfaces 25c of the plurality of main magnets 25 are brought into abutment with the peripheral surface 36a of the mold 35. Thereby, even when there is a dimensional tolerance or a molding deviation between the plurality of main magnets 25, the positioning of the plurality of main magnets 25 can be performed with high accuracy. Also, by moving the main magnets 25 before the auxiliary magnets 26, it is possible to suppress the molten resin from entering between the peripheral surface 36a of the mold 35 and the side surfaces 25c of the main magnets 25, and it is possible to expose at least a portion of the side surfaces 25c of the stator side Rl from the resin 24.

[0085] Also, by supplying the molten resin toward the plurality of second inclined surfaces 26c, the positioning of the plurality of auxiliary magnets 26 can be performed. Further, by forming the main magnets 25 in a shape that suppresses the auxiliary magnets 26 from moving toward the opposite side of the stator side Rl, it is possible to limit the positions of the auxiliary magnets 26 after the positioning.

[0086] Also, in the resin molding process, the main magnets 25 and the auxiliary magnets 26 are moved, and thereby the flowability of the molten resin can be improved.

[0087] Further, by densely arranging the main magnets 25 and the auxiliary magnets 26 in the circumferential direction C, it is possible to improve the magnetic force of the rotor 20 and improve the torque of the motor 16.

[0088] ​(Modified example 1)

[0089] Figure 19 A main magnet 45 is a modified example of the main magnet 25.

[0090] Instead of the main magnet 25 explained in the above embodiment, the main magnet 45 can be used. Regarding the main magnet 45, an inclined surface 25e having a smaller area than the first inclined surface 25d is further formed at an end portion 45A on the side where the first inclined surface 25d is formed. The main magnet 45 receives a larger force from the molten resin more at the first inclined surface 25d having a larger area than the inclined surface 25e. As in the above embodiment, the main magnet 45 moves in the direction toward the peripheral surface 36a of the mold 35, and thus the side surface 25c of the main magnet 45 can be brought into contact with the peripheral surface 36a of the mold 35 (see FIG. 2). Figure 12 ).

[0091] In addition, in the above embodiment, a case where one inclined surface 25e is formed at the end portion 45A is exemplified, but a plurality of inclined surfaces 25e can be formed at the end portion 45A. Also, at least one inclined surface (not shown) having a smaller area than the second inclined surface 26c can be formed at the end portion of the auxiliary magnet 26 explained previously where the second inclined surface 26c is formed. Figure 19

[0092] (Modified example 2)

[0093] In the above embodiment, the rotor 20 is an outer rotor, but the rotor is not limited thereto. The rotor can also be an inner rotor.

[0094] (Modified example 3)

[0095] In the above embodiment, a case where the rotor magnet 23 has the main magnet 25 and the auxiliary magnet 26 is exemplified and explained, but the rotor magnet 23 can be constituted only by a plurality of main magnets 25, for example. That is, the rotor magnet 23 is not limited to a Halbach array magnet.

[0096] According to at least one embodiment explained above, by having the main magnet 25 including the first inclined surface 25d, positioning of the plurality of main magnets 25 can be performed with high accuracy.

[0097] The above describes several embodiments of the present application, but the above embodiments are merely presented as examples and are not intended to limit the scope of the application. The above embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the application. The above embodiments and modifications are included in the scope and spirit of the application, and are also included in the scope of the application and the equivalent thereof described in the technical solution.​

Claims

1. A manufacturing method of a rotor, comprising: a magnet arrangement step of arranging a plurality of unexcited main magnets each having a first inclined surface and formed in a columnar shape extending in an up-down direction along a rotation axis, in a circular ring shape or a circular arc shape at intervals in a circumferential direction so that a peripheral surface of a mold arranged on a stator side opposes a side surface of the main magnet, and so that a first normal line of the first inclined surface is inclined in a radial direction toward an opposite side of the stator side and with respect to the rotation axis; a resin molding step of injecting a molten resin directly or indirectly with respect to the first inclined surface from above the main magnet via the mold to thereby move the main magnet toward the stator side, and molding the main magnet with the resin; and a post-excitation step of exciting the main magnet after the resin molding. In the magnet arrangement step, a plurality of unexcited auxiliary magnets each having a second inclined surface and formed in a columnar shape extending in the up-down direction are arranged between the main magnets adjacent to each other in the circumferential direction so that a second normal line of the second inclined surface is inclined in the radial direction toward the stator side and with respect to the rotation axis. In the post-excitation step, the main magnet and the auxiliary magnet after the resin molding are excited.

2. The manufacturing method of a rotor according to claim 1, wherein in the resin molding step, the main magnet is moved toward the stator side by supplying the resin to the first inclined surface, and the auxiliary magnet is moved toward the opposite side by supplying the molten resin to the second inclined surface.

3. The manufacturing method of a rotor according to claim 1, wherein in the resin molding step, the main magnet is moved toward the stator side by supplying the resin to the first inclined surface, the peripheral surface of the mold is brought into contact with the side surface of the main magnet, and at least a part of the side surface of the main magnet is exposed from the resin.

4. The manufacturing method of a rotor according to any one of claims 1 to 3, wherein in the post-excitation step, the main magnet is excited in the radial direction, and the auxiliary magnet is excited in the circumferential direction.

5. A rotor, comprising: a main magnet formed in a columnar shape extending in an up-down direction along a rotation axis, arranged at intervals in a circular ring shape, having a side surface arranged on a stator side and a first inclined surface inclined at one end portion in the up-down direction with respect to the up-down direction, and having a first normal line of the first inclined surface inclined in a radial direction toward an opposite side of the stator side and with respect to the rotation axis; and a resin molding the main magnet and exposing at least a part of the side surface of the main magnet. The rotor has an auxiliary magnet arranged between the main magnets adjacent to each other in a circumferential direction. ​ ​ ​ ​ ​ ​ ​ ​ The auxiliary magnet is formed in a columnar shape extending in the up-down direction, has a second inclined surface which is an inclined surface with respect to the up-down direction at the one end portion of the up-down direction, a second normal line of the second inclined surface is inclined with respect to the rotation axis toward the stator side in the radial direction, the first inclined surface is arranged protruding in the axial direction of the rotation axis compared to the second inclined surface.

6. The rotor according to claim 5, wherein the auxiliary magnet contacts at least a portion of the main magnets which are adjacent to each other in the circumferential direction.

7. The rotor according to claim 5 or 6, wherein the main magnets are magnets which are excited in the radial direction, the auxiliary magnet is a magnet which is excited in the circumferential direction.

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