Outer rotor-type motor and method for manufacturing the same

Abstract

To provide an outer rotor-type motor which can enhance the efficiency of attaching a permanent magnet to a rotor core.SOLUTION: The outer rotor-type motor includes: a stator 1; and a rotor 2 on the outside of the stator 1 in a radiation direction D2. The rotor 2 includes: an inner core 21 with an inner cylindrical part 26; an outer core 22 having am outer cylindrical part 28 formed cylindrically, the inner cylindrical part 26 being arranged in the inside of the outer part 28 in a radial direction D2; and a plurality of permanent magnets 23 located in an outer peripheral surface 26a of the inner cylindrical part 26, the permanent magnets being lined in a peripheral direction D3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to an outer rotor type motor and a method for manufacturing the same.

Background Art

[0002] Conventionally, an outer rotor type motor including a stator and a rotor provided on the radially outer side with respect to the stator has been known. The rotor has a rotor yoke extending radially outward from a rotating shaft, a cylindrical rotor core provided on the rotor yoke, and a plurality of permanent magnets provided on the rotor core and arranged in the circumferential direction. The rotor core is formed with a plurality of magnet insertion holes into which each of the plurality of permanent magnets is inserted one by one (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration of the outer rotor type motor described in Patent Document 1, in order to attach each permanent magnet to the rotor core, each permanent magnet has to be inserted one by one into the corresponding magnet insertion hole. As a result, there is a problem that the efficiency of the work of attaching the permanent magnets to the rotor core is poor.

[0005] This invention has been made to solve the above-described problems, and an object thereof is to provide an outer rotor type motor and a method for manufacturing the same that can improve the efficiency of the work of attaching permanent magnets to a rotor core.

Means for Solving the Problems

[0006] The outer rotor type motor according to the present invention includes a stator and a rotor provided on the radially outer side of the stator. The rotor includes an inner core having an inner cylindrical portion formed in a cylindrical shape, an outer core having an outer cylindrical portion formed in a cylindrical shape, with the inner cylindrical portion disposed inside the outer cylindrical portion in the radial direction, and a plurality of permanent magnets provided on the outer peripheral surface of the inner cylindrical portion or the inner peripheral surface of the outer cylindrical portion and arranged in the circumferential direction. In the outer rotor type motor according to the present invention, the plurality of permanent magnets are provided on the outer peripheral surface of the inner cylindrical portion. In the outer rotor type motor according to the present invention, the rotor includes a spacer provided on the outer peripheral surface of the inner cylindrical portion or the inner peripheral surface of the outer cylindrical portion, and the spacer is disposed between a pair of permanent magnets adjacent to each other in the circumferential direction among the plurality of permanent magnets. The manufacturing method of the outer rotor type motor according to the present invention includes a step of attaching pre-magnetization permanent magnets, in which a plurality of pre-magnetization permanent magnets are provided on the outer peripheral surface of the inner cylindrical portion or the inner peripheral surface of the outer cylindrical portion, a magnetization step of magnetizing each of the plurality of pre-magnetization permanent magnets after the step of attaching pre-magnetization permanent magnets, and a step of attaching a split core of disposing the inner cylindrical portion inside the outer cylindrical portion in the radial direction after the magnetization step.

Advantages of the Invention

[0007] According to the outer rotor type motor and its manufacturing method according to the present invention, the efficiency of the work of attaching permanent magnets to the rotor core can be improved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] Embodiment 1. FIG. 1 is a plan view showing an outer rotor type motor according to Embodiment 1. The outer rotor type motor includes a rotation shaft (not shown), a stator 1, a rotor 2, and a bearing (not shown).

[0010] The shape of the rotation shaft is cylindrical. The direction along the axis of the rotation shaft is defined as the axial direction D1. The direction along the radius of the circle centered on the axis of the rotation shaft in a plane orthogonal to the axis of the rotation shaft is defined as the radial direction D2. The direction along the circumference of the circle centered on the axis of the rotation shaft in a plane orthogonal to the axis of the rotation shaft is defined as the circumferential direction D3.

[0011] The stator 1 is provided outside the rotation shaft in the radial direction D2. The stator 1 is arranged away from the outer peripheral surface of the rotation shaft. The rotation shaft is rotatable with respect to the stator 1.

[0012] The stator 1 includes a stator core 11 and a plurality of coils 12. The plurality of coils 12 are provided on the stator core 11. The plurality of coils 12 are arranged in a row in the circumferential direction D3. A current is supplied to the plurality of coils 12 from a power supply device (not shown).

[0013] The rotor 2 is rotatably supported by the stator 1 via bearings. The rotor 2 is provided outside the stator 1 in the radial direction D2. The rotor 2 includes an inner core 21, an outer core 22, a plurality of permanent magnets 23, and a plurality of spacers 24. The inner core 21, the outer core 22, and the plurality of spacers 24 constitute a rotor core.

[0014] FIG. 2 is a perspective view showing the inner core 21 of FIG. 1. FIG. 3 is a front view showing the inner core 21 of FIG. 2. FIG. 3 shows a front view when the inner core 21 is viewed from one side in the axial direction D1.

[0015] The inner core 21 includes an inner bottom plate portion 25 and an inner cylindrical portion 26. The shape of the inner bottom plate portion 25 is a disk shape. The inner bottom plate portion 25 is arranged along a plane perpendicular to the axial direction D1. A through hole 25a is formed in the central portion of the inner bottom plate portion 25 in the radial direction D2. The through hole 25a penetrates the inner bottom plate portion 25 in the axial direction D1. A rotating shaft is inserted into the through hole 25a.

[0016] The shape of the inner cylindrical portion 26 is a cylindrical shape. The inner cylindrical portion 26 is provided at the outer end of the inner bottom plate portion 25 in the radial direction D2. The inner cylindrical portion 26 is arranged so as to extend from the inner bottom plate portion 25 to one side in the axial direction D1. The inner bottom plate portion 25 and the inner cylindrical portion 26 are integrally formed with each other.

[0017] FIG. 4 is a perspective view showing the outer core 22 of FIG. 1. FIG. 5 is a front view showing the outer core 22 of FIG. 4. FIG. 5 shows a front view when the outer core 22 is viewed from one side in the axial direction D1.

[0018] The outer core 22 includes an outer bottom plate portion 27 and an outer cylindrical portion 28. The shape of the outer bottom plate portion 27 is disc-shaped. The outer bottom plate portion 27 is arranged along a plane perpendicular to the axial direction D1. A through hole 27a is formed in the central portion of the outer bottom plate portion 27 in the radial direction D2. The through hole 27a penetrates the outer bottom plate portion 27 in the axial direction D1. A rotating shaft is inserted into the through hole 27a.

[0019] The inner bottom plate portion 25 and the outer bottom plate portion 27 face each other in the axial direction D1. The inner bottom plate portion 25 is arranged on one side of the outer bottom plate portion 27 in the axial direction D1.

[0020] The shape of the outer cylindrical portion 28 is cylindrical. The outer cylindrical portion 28 is provided at the outer end of the outer bottom plate portion 27 in the radial direction D2. The outer cylindrical portion 28 is arranged so as to extend from the outer bottom plate portion 27 to one side in the axial direction D1. The outer bottom plate portion 27 and the outer cylindrical portion 28 are integrally formed with each other.

[0021] The inner cylindrical portion 26 and the outer cylindrical portion 28 face each other in the radial direction D2. The inner cylindrical portion 26 is arranged inside the outer cylindrical portion 28 in the radial direction D2.

[0022] A plurality of spacers 24 are provided on the inner peripheral surface 28a of the outer cylindrical portion 28. The plurality of spacers 24 are arranged in a row in the circumferential direction D3.

[0023] FIG. 6 is a perspective view showing the inner core 21 and the plurality of permanent magnets 23 of FIG. 1. The plurality of permanent magnets 23 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26. The plurality of permanent magnets 23 are arranged in a row in the circumferential direction D3. Each permanent magnet 23 is fixed to the outer peripheral surface 26a of the inner cylindrical portion 26 via an adhesive (not shown).

[0024] FIG. 7 is a perspective view showing the inner core 21, the outer core 22, and the plurality of permanent magnets 23 of FIG. 1. FIG. 8 is a front view showing the inner core 21, the outer core 22, and the plurality of permanent magnets 23 of FIG. 7. In FIG. 8, a front view is shown when looking at the inner core 21, the outer core 22, and the plurality of permanent magnets 23 from one side in the axial direction D1.

[0025] A plurality of spacers 24 are respectively arranged between a pair of permanent magnets 23 adjacent to each other in the circumferential direction D3 among the plurality of permanent magnets 23.

[0026] Each permanent magnet 23 is inserted one by one into a plurality of magnet insertion holes formed by the inner cylindrical portion 26 of the inner core 21, the outer cylindrical portion 28 of the outer core 22, and a pair of spacers 24 adjacent to each other in the circumferential direction D3. Therefore, the outer rotor type motor according to Embodiment 1 is an IPM (Interior Permanent Magnet) type motor.

[0027] Next, a method for manufacturing the outer rotor type motor according to Embodiment 1 will be described. Specifically, a method for manufacturing the rotor 2 of the outer rotor type motor will be described. FIG. 9 is a flowchart showing the method for manufacturing the outer rotor type motor according to Embodiment 1.

[0028] In the manufacturing process of the outer rotor type motor, first, in step S101, a step of attaching the permanent magnet before magnetization is performed. In the step of attaching the permanent magnet before magnetization, a plurality of permanent magnets 23 before magnetization are attached to the outer peripheral surface 26a of the inner cylindrical portion 26.

[0029] Thereafter, in step S102, a magnetization process is performed. In the magnetization process, each of the plurality of permanent magnets 23 before magnetization is magnetized. In the magnetization process, each permanent magnet 23 is magnetized using a magnetization device (not shown).

[0030] Since each permanent magnet 23 is attached to the outer peripheral surface 26a of the inner cylindrical portion 26, a magnetizing device can be disposed on the outer side in the radial direction D2 with respect to the inner cylindrical portion 26. The space on the outer side in the radial direction D2 with respect to the inner cylindrical portion 26 is larger than the space on the inner side in the radial direction D2 with respect to the inner cylindrical portion 26. Therefore, by disposing the magnetizing device on the outer side in the radial direction D2 with respect to the inner cylindrical portion 26, the limitation on the size of the magnetizing device can be relaxed.

[0031] Thereafter, in step S103, a split core attachment process is performed. In the split core attachment process, the inner cylindrical portion 26 is disposed inside the outer cylindrical portion 28 in the radial direction D2. As a result, a plurality of permanent magnets 23 are inserted one by one into a plurality of magnet insertion holes formed by the inner cylindrical portion 26 of the inner core 21, the outer cylindrical portion 28 of the outer core 22, and a pair of spacers 24 adjacent to each other in the circumferential direction D3. Thus, the manufacturing process of the rotor 2 of the outer rotor type motor is completed.

[0032] As described above, the outer rotor type motor according to Embodiment 1 includes a stator 1 and a rotor 2 provided on the outer side in the radial direction D2 with respect to the stator 1. The rotor 2 includes an inner core 21, an outer core 22, and a plurality of permanent magnets 23. The inner core 21 has an inner cylindrical portion 26 formed in a cylindrical shape. The outer core 22 has an outer cylindrical portion 28 formed in a cylindrical shape. The inner cylindrical portion 26 is disposed inside the outer cylindrical portion 28 in the radial direction D2. The plurality of permanent magnets 23 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26 and are arranged in the circumferential direction D3. According to this configuration, each permanent magnet 23 can be attached to the rotor core without performing the operation of inserting each permanent magnet 23 into the corresponding magnet insertion hole one by one. Thereby, the efficiency of the operation of attaching the permanent magnet 23 to the rotor core can be improved.

[0033] Also, in the outer rotor type motor according to Embodiment 1, the plurality of permanent magnets 23 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26. According to this configuration, the magnetizing device can be arranged outside the inner cylindrical portion 26 in the radial direction D2. Thereby, the limitation on the size of the magnetizing device can be relaxed.

[0034] Also, in the outer rotor type motor according to Embodiment 1, the rotor 2 includes a spacer 24 provided on the inner peripheral surface 28a of the outer cylindrical portion 28. The spacer 24 is arranged between a pair of permanent magnets 23 adjacent to each other in the circumferential direction D3 among the plurality of permanent magnets 23. According to this configuration, it is possible to suppress the permanent magnets 23 from moving in the circumferential direction D3 with respect to the outer peripheral surface 26a of the inner cylindrical portion 26.

[0035] Also, the manufacturing method of the outer rotor type motor according to Embodiment 1 includes a pre-magnetization permanent magnet mounting step, a magnetization step performed after the pre-magnetization permanent magnet mounting step, and a split core mounting step performed after the magnetization step. In the pre-magnetization permanent magnet mounting step, a plurality of pre-magnetization permanent magnets 23 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26. In the magnetization step, each of the plurality of pre-magnetization permanent magnets 23 is magnetized. In the split core mounting step, the inner cylindrical portion 26 is arranged inside the outer cylindrical portion 28 in the radial direction D2. According to this configuration, each permanent magnet 23 can be attached to the rotor core without performing the operation of inserting each permanent magnet 23 into the corresponding magnet insertion hole one by one. Thereby, the efficiency of the operation of attaching the permanent magnets 23 to the rotor core can be improved.

[0036] Note that, in the outer rotor type motor according to Embodiment 1, the configuration in which a plurality of permanent magnets 23 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26 has been described. However, the present invention is not limited to this configuration. A configuration in which a plurality of permanent magnets 23 are provided on the inner peripheral surface 28a of the outer cylindrical portion 28 may be employed. When the permanent magnets 23 are provided on the inner peripheral surface 28a of the outer cylindrical portion 28 and the spacers 24 are provided on the inner peripheral surface 28a of the outer cylindrical portion 28, the positioning of the permanent magnets 23 when attaching the permanent magnets 23 to the inner peripheral surface 28a of the outer cylindrical portion 28 can be easily performed. Further, in this case, the step of disposing the inner cylindrical portion 26 inside the outer cylindrical portion 28 in the radial direction D2 can be easily performed.

[0037] Also, in the outer rotor type motor according to Embodiment 1, the configuration in which the spacers 24 are provided on the inner peripheral surface 28a of the outer cylindrical portion 28 has been described. However, the present invention is not limited to this configuration. A configuration in which the spacers 24 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26 may be employed. When the permanent magnets 23 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26 and the spacers 24 are provided on the outer peripheral surface 26a of the inner cylindrical portion 26, the positioning of the permanent magnets 23 when attaching the permanent magnets 23 to the outer peripheral surface 26a of the inner cylindrical portion 26 can be easily performed. Further, in this case, the step of disposing the inner cylindrical portion 26 inside the outer cylindrical portion 28 in the radial direction D2 can be easily performed.

[0038] As described above, the outer rotor type motor and the method of manufacturing the same according to the preferred Embodiment 1 have been described. However, the present invention is not limited to the outer rotor type motor and the method of manufacturing the same according to Embodiment 1 described above. Various modifications and conversions can be made to the outer rotor type motor and the method of manufacturing the same according to Embodiment 1 described above without departing from the scope described in the claims.

Explanation of Reference Numerals

[0039] 1 Stator, 2 Rotor, 11 Stator Core, 12 Coil, 21 Inner Core, 22 Outer Core, 23 Permanent Magnet, 24 Spacer, 25 Inner Bottom Plate Portion, 25a Through-Hole, 26 Inner Cylindrical Portion, 26a Outer Peripheral Surface, 27 Outer Bottom Plate Portion, 27a Through-Hole, 28 Outer Cylindrical Portion, 28a Inner Peripheral Surface.

Claims

1. A stator (1), a rotor (2) provided radially outside the stator (1), and comprising the rotor (2) includes an inner core (21) having an inner cylindrical portion (26) formed in a cylindrical shape, an outer core (22) having an outer cylindrical portion (28) formed in a cylindrical shape, with the inner cylindrical portion (26) disposed inside the outer cylindrical portion (28) in the radial direction, a plurality of permanent magnets (23) provided on the outer peripheral surface (26a) of the inner cylindrical portion (26) or the inner peripheral surface (28a) of the outer cylindrical portion (28), arranged in the circumferential direction, and is an outer rotor type motor.

2. The outer rotor type motor according to claim 1, wherein the plurality of permanent magnets (23) are provided on the outer peripheral surface (26a) of the inner cylindrical portion (26).

3. The rotor (2) includes a spacer (24) provided on the outer peripheral surface (26a) of the inner cylindrical portion (26) or the inner peripheral surface (28a) of the outer cylindrical portion (28), and the outer rotor type motor according to claim 1 or claim 2, wherein the spacer (24) is disposed between a pair of permanent magnets (23) adjacent to each other in the circumferential direction among the plurality of permanent magnets (23).

4. A method for manufacturing an outer rotor type motor according to claim 1 or claim 2, comprising a pre-magnetization permanent magnet mounting step of providing the plurality of pre-magnetization permanent magnets (23) on the outer peripheral surface (26a) of the inner cylindrical portion (26) or the inner peripheral surface (28a) of the outer cylindrical portion (28), a magnetization step of magnetizing each of the plurality of pre-magnetization permanent magnets (23) after the pre-magnetization permanent magnet mounting step, and a split core mounting step of disposing the inner cylindrical portion (26) inside the outer cylindrical portion (28) in the radial direction after the magnetization step. A method for manufacturing an outer rotor type motor.

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