rotor

Abstract

To provide a technique capable of sealing a magnet with resin while stably supporting the magnet.SOLUTION: A rotor includes a core disposed around a rotating shaft, a plurality of plate-shaped magnets which are arranged around the core and extend in an axial direction of the rotating shaft, a fixing portion for fixing the plurality of magnets to the core, and a sealing member which is made of resin and seals the core, the plurality of magnets, and the fixing portion. The sealing member includes an inlet mark for resin injection at a position above upper surface portions of the magnets in the axial direction. A lower end portion of the core in the axial direction includes a first protrusion protruding outward in the radial direction of the core. The lower surface portion of the magnet in the axial direction is in contact with the upper surface portion of the first protrusion, and is supported by the first protrusion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a rotor. [Background technology]

[0002] The rotor disclosed in Patent Document 1 includes a core arranged around a rotating shaft, a plurality of plate-shaped magnets arranged around the core and extending in the axial direction of the rotating shaft, and a sealing member made of resin that seals the core and the plurality of magnets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-81776 Summary of the Invention [Problem to be solved by the invention]

[0004] When manufacturing a sealing member that seals a core and multiple magnets, the resin that is the material for the sealing member is sometimes injected from above the magnets. When this happens, the injected resin can hit the magnets, causing them to move, potentially resulting in misalignment of the magnets during sealing. This specification provides a technology that allows resin sealing while stably supporting the magnets. [Means for solving the problem]

[0005] The rotor disclosed in this specification includes a core arranged around a rotating shaft, a plurality of plate-shaped magnets arranged around the core and extending in the axial direction of the rotating shaft, a fixing portion that fixes the plurality of magnets to the core, and a sealing member made of resin that seals the core, the plurality of magnets, and the fixing portion. The sealing member has an inlet mark for resin injection at a position above an upper surface of the magnet in the axial direction. The lower end of the core in the axial direction has a first protrusion that protrudes radially outward from the core. The lower surface of the magnet in the axial direction abuts on an upper surface of the first protrusion and is supported by the first protrusion.

[0006] With this configuration, the first protrusions can stably support the multiple magnets. In this state, the multiple magnets can be sealed with the sealing member. Even in a configuration in which resin is injected from above the magnets, the magnets can be sealed with resin while being stably supported.

[0007] An upper end of the core in the axial direction may include a second protrusion that protrudes radially outward from the core. An upper surface of the magnet in the axial direction may not abut on the second protrusion, and a gap may be provided between the upper surface of the magnet and the second protrusion.

[0008] This configuration prevents the resin injected from above the magnet from directly hitting the top surface of the magnet, and also allows the resin of the sealing member to fill the gap, ensuring stable support for the magnet.

[0009] The fixing portion may be a tape that fixes the magnets to the core at a position above the center of the core in the axial direction.

[0010] This configuration can prevent the magnet from falling radially outward of the core due to moment.

[0011] This specification discloses a method for manufacturing a rotor including a core arranged around a rotating shaft, a plurality of plate-shaped magnets arranged around the core and extending in the axial direction of the rotating shaft, a fixing portion that fixes the plurality of magnets to the core, and a sealing member made of resin that seals the core, the plurality of magnets, and the fixing portion. The lower end of the core in the axial direction has a first protrusion that protrudes radially outward from the core. The lower surface of the magnet in the axial direction abuts on the upper surface of the first protrusion and is supported by the first protrusion. The rotor manufacturing method includes the steps of injecting resin into a mold that has a resin injection inlet located above the upper surface of the magnet in the axial direction, and curing the injected resin.

[0012] With this configuration, even if the resin is injected from above the magnet, the magnet can be sealed with resin while being stably supported. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a perspective view of the rotor of the embodiment (before being sealed by the sealing member). [Figure 2] FIG. 2 is a perspective view of the rotor of the embodiment (after being sealed by the sealing member). [Figure 3] FIG. 3 is a cross-sectional view of the rotor of the embodiment (a cross-sectional view taken along III-III in FIG. 2). [Figure 4] FIG. 4 is a cross-sectional view of the rotor of the embodiment (a cross-sectional view taken along line IV-IV in FIG. 3). [Figure 5] Enlarged view of part V in Figure 3. [Figure 6] Enlarged view of part VI of Figure 3. [Figure 7] Enlarged view of part VII of Figure 4. [Figure 8] FIG. [Figure 9] 5A to 5C are diagrams illustrating a method for manufacturing a sealing member according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] A rotor 10 according to an embodiment will be described with reference to the drawings. As shown in Figures 1 to 3, the rotor 10 includes a core 12 arranged around a rotary shaft 6, a plurality of magnets 14 arranged around the core 12, tape 18 (an example of a fixing portion) that fixes the plurality of magnets 14 to the core 12, and a sealing member 16 that seals the core 12, the plurality of magnets 14, and tape 18.

[0015] The rotor 10 is combined with a stator 4 disposed around the rotor 10 to form a motor 2. In a modified example, the rotor 10 may be combined with the stator 4 to form a generator. The stator 4 includes a plurality of coils (not shown) to which three-phase alternating current is supplied. When current is supplied to the plurality of coils of the stator 4, the rotor 10 rotates relative to the stator 4. The rotor 10 is configured to be rotatable about a rotation axis 6. The principle by which the rotor 10 rotates is already known, and therefore a detailed description thereof will be omitted.

[0016] The configuration of the rotor 10 will be described in detail. The rotor 10 includes a core 12 made of a magnetic material. The core 12 is formed by stacking a plurality of plate-shaped members 20. The plurality of plate-shaped members 20 are stacked in the axial direction (Z direction) of the rotating shaft 6. Each plate-shaped member 20 is made of a metal containing iron, for example. A rotating shaft 6 is inserted into the radial center of the core 12. The rotating shaft 6 is inserted into the radial center of each of the plurality of plate-shaped members 20. The rotating shaft 6 is fixed to the radial center of the core 12 (the radial center of the plate-shaped members 20).

[0017] As shown in Fig. 4, a plurality of recesses 21 are provided on the outer peripheral surface of core 12. The recesses 21 are arranged side by side at intervals in the circumferential direction of core 12. A magnet 14 is disposed in each of the recesses 21. The magnets 14 are housed in the recesses 21.

[0018] Each magnet 14 has a plate-like configuration and extends in the axial direction of the rotating shaft 6, as shown in Figure 3. The longitudinal direction of the magnet 14 extends in the axial direction of the rotating shaft 6, and the lateral direction of the magnet 14 extends in a direction perpendicular to the axial direction of the rotating shaft 6.

[0019] 5, the lower end of the core 12 is provided with a first protruding portion 22 that protrudes in the radial direction of the core 12. The first protruding portion 22 is formed by the plate-like member 20 arranged at the lower end of the core 12 protruding further outward in the radial direction of the core 12 than the other plate-like members 20.

[0020] A lower surface 142 in the longitudinal direction of the magnet 14 abuts against an upper surface 222 of the first protrusion 22 of the core 12. The first protrusion 22 of the core 12 supports the magnet 14. A tip end 221 of the first protrusion 22 is located inside the outer surface 141 of the magnet 14 in the radial direction of the core 12.

[0021] 6, the upper end of the core 12 is provided with a second protruding portion 24 that protrudes in the radial direction of the core 12. The second protruding portion 24 is formed by the plate-like member 20 arranged at the upper end of the core 12 protruding further outward in the radial direction of the core 12 than the other plate-like members 20.

[0022] An upper surface 143 of the magnet 14 in the longitudinal direction does not abut against the second protrusion 24 of the core 12. A gap 26 is provided between the upper surface 143 of the magnet 14 in the longitudinal direction and the second protrusion 24 of the core 12. The gap 26 is filled with the resin of the sealing member 16. A tip end 241 of the second protrusion 24 is located more inward than the outer surface 141 of the magnet 14 in the radial direction of the core 12.

[0023] As shown in FIG. 1, magnet 14 is housed in recess 21 of core 12 and fixed to core 12 by tape 18. Tape 18 is wound around core 12 and the plurality of magnets 14. Tape 18 fixes magnet 14 to core 12 above the center of magnet 14 in the longitudinal direction. Tape 18 also fixes magnet 14 to core 12 above the center of core 12 in the axial direction (Z direction) of rotation shaft 6. Tape 18 is heat resistant.

[0024] Next, the sealing member 16 will be described. The sealing member 16 that seals the core 12, the multiple magnets 14, and the tape 18 is a non-magnetic material made of a resin containing fibers (for example, glass fibers or carbon fibers). The resin that is the material of the sealing member 16 is sometimes called glass fiber reinforced plastic or carbon fiber reinforced plastic. As shown in FIG. 2, the rotor 10 after being sealed with the sealing member 16 is configured in a substantially cylindrical shape. As shown in FIG. 8, there is a resin injection entrance mark 40 on the top surface of the sealing member 16. The resin injection entrance mark 40 is a mark formed when the sealing member 16 is manufactured.

[0025] Next, a method for manufacturing the rotor 10 will be described. In the manufacturing method of this embodiment, the rotor 10 (see FIG. 1) is prepared before being sealed with the sealing member 16. Also, as shown in FIG. 9, a mold 42 for manufacturing the sealing member 16 is prepared. The manufacturing method of the rotor 10 of this embodiment includes a step of manufacturing the sealing member 16.

[0026] The process of producing the sealing member 16 includes the steps of injecting resin into a mold 42 and curing the injected resin. The mold 42 for the sealing member 16 includes an inlet 44 for injecting resin into the mold 42. The inlet 44 is provided on the upper surface of the mold 42. The inlet 44 is provided at a position above the upper surface 143 of the magnet 14 in the axial direction of the rotating shaft 6 (the longitudinal direction of the magnet 14).

[0027] In the process of injecting resin into the mold 42, fiber-reinforced resin is injected through an inlet 44 provided in the mold 42. The resin injected into the mold 42 from the inlet 44 flows from the top to the bottom along the axial direction of the rotating shaft 6 (the longitudinal direction of the magnet 14). After hitting the second protrusion 24 (see FIG. 6) provided at the top end of the core 12, the resin flows along the magnet 14.

[0028] After the resin is filled into the mold 42, a step of hardening the resin is carried out. In the step of hardening the resin, for example, the mold 42 is cooled to cool the inside of the mold 42 and harden the resin. In a modified example, the resin may be irradiated with ultraviolet light. The hardening of the resin produces a sealing member 16. The sealing member 16 has an inlet mark 40, which is a mark of an inlet 44 of the mold 42. The sealing member 16 is provided on the upper surface of the sealing member 16 in the axial direction of the rotating shaft 6.

[0029] (effect) The rotor 10 of the first embodiment has been described above. As described above, the rotor 10 includes the core 12 arranged around the rotating shaft 6, a plurality of plate-shaped magnets 14 arranged around the core 12 and extending in the axial direction of the rotating shaft 6, tape 18 that secures the magnets 14 to the core 12, and a sealing member 16 made of resin that seals the core 12, the magnets 14, and tape 18. The sealing member 16 includes a resin injection inlet mark 40 located above an upper surface 143 of the magnet 14 in the axial direction of the rotating shaft 6. The lower end of the core 12 in the axial direction of the rotating shaft 6 includes a first protrusion 22 that protrudes radially outward from the core 12. The lower surface 142 of the magnet 14 in the axial direction of the rotating shaft 6 abuts against an upper surface 222 of the first protrusion 22 and is supported by the first protrusion 22.

[0030] According to this configuration, the plurality of magnets 14 can be stably supported by the first protrusion 22. In this state, the plurality of magnets 14 can be sealed by the sealing member 16. Therefore, even in a configuration in which resin is injected from above the magnets 14, the magnets 14 can be sealed with resin while being stably supported.

[0031] Additionally, the upper end of core 12 in the axial direction of rotating shaft 6 is provided with second protrusion 24 that protrudes radially outward from core 12. Top surface 143 of magnet 14 in the axial direction of rotating shaft 6 does not abut against second protrusion 24, and a gap 26 is provided between top surface 143 of magnet 14 and second protrusion 24. This configuration prevents resin injected from above magnet 14 from directly hitting top surface 143 of magnet 14. Furthermore, resin of sealing member 16 enters gap 26, allowing magnet 14 to be stably supported.

[0032] Furthermore, tape 18 that secures magnets 14 secures multiple magnets 14 to core 12 at a position above the center of core 12 in the axial direction of rotating shaft 6. This configuration can prevent magnets 14 from tipping radially outward from core 12 due to moment.

[0033] Furthermore, the manufacturing method of rotor 10 described above includes the steps of injecting resin into mold 42, which has resin injection inlet 44 located above upper surface 143 of magnet 14 in the axial direction of rotating shaft 6, and hardening the injected resin. Because the lower end of magnet 14 is supported by first protrusion 22, even in a configuration in which resin is injected from above magnet 14, magnet 14 can be sealed with resin while being stably supported.

[0034] (Variation) In the above embodiment, tape 18 has been described as an example of a fixing portion for fixing magnet 14 to core 12, but this configuration is not limiting. In a modified example, adhesive may be used as the fixing portion for fixing magnet 14 to core 12. Adhesive may be applied or filled between magnet 14 and core 12. Alternatively, both tape 18 and adhesive may be used.

[0035] Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives itself has technical utility. [Explanation of symbols]

[0036] 2: motor, 4: stator, 6: rotating shaft, 10: rotor, 12: core, 14: magnet, 16: sealing member, 18: tape, 20: plate-shaped member, 21: recess, 22: first protrusion, 24: second protrusion, 26: gap, 40: entrance mark, 42: mold, 44: entrance

Claims

1. a core disposed around a rotation axis; a plurality of plate-shaped magnets arranged around the core and extending in the axial direction of the rotation shaft; a fixing portion that fixes the plurality of magnets to the core; a sealing member made of resin that seals the core, the plurality of magnets, and the fixed portion, the sealing member has a resin injection inlet mark at a position above an upper surface of the magnet in the axial direction, a lower end portion of the core in the axial direction includes a first protruding portion protruding radially outward from the core, A rotor in which a lower surface portion of the magnet in the axial direction abuts against an upper surface portion of the first protrusion and is supported by the first protrusion.

2. 2. The rotor of claim 1, an upper end portion of the core in the axial direction includes a second protruding portion protruding radially outward from the core; A rotor in which an upper surface portion of the magnet in the axial direction does not abut the second protruding portion, and a gap is provided between the upper surface portion of the magnet and the second protruding portion.

3. 3. The rotor according to claim 1 or 2, The rotor, wherein the fixing portion is a tape that fixes the plurality of magnets to the core at a position above the center of the core in the axial direction.

4. a core disposed around a rotation axis; a plurality of plate-shaped magnets arranged around the core and extending in the axial direction of the rotation shaft; a fixing portion that fixes the plurality of magnets to the core; a method for manufacturing a rotor including the core, the plurality of magnets, and a sealing member made of resin that seals the fixed portion, the method comprising: a lower end portion of the core in the axial direction includes a first protruding portion protruding radially outward from the core, a lower surface of the magnet in the axial direction abuts against an upper surface of the first protrusion and is supported by the first protrusion, Injecting resin into a mold having a resin injection inlet located above the upper surface of the magnet in the axial direction; and hardening the injected resin.

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