JP2005110462A - Small-sized motor and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized motor by which superior reliability is maintained, even when a core and a magnet are arranged by approaching them without providing a partition plate or the like between them, while fixing the core with superior support strength. <P>SOLUTION: A stator coil 4 of the core 3 is approached and arranged to a base 1 to the axial center direction 0 of a motor-rotating shaft 11. An adhesive 5 is interposed at a place where the stator coil 4 and the base 1 approach. With this constitution, the stator coil 4, which is made to approach the base 1 having a relatively larger area, is bonded with the base 1 and is fixed. As a result, the core 3 can be fixed with superior support strength, and vibration of the core 3 is prevented. Since the base 1 and the stator coil 4 are arranged close to each other, only a small amount of the adhesive 5 is required; and an adhesive amount is adjusted easily so as not to flow to the magnet 10 side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a small motor used for a spindle motor for a hard disk or the like.

Along with the miniaturization of hard disks, motors used for hard disk spindle motors and the like are also demanded that can be accommodated in a limited small space.
As a conventional core fixing method for such a small motor, as shown in FIG. 9, a core 32 is disposed between the base 30 and the motor cover 31, and the outer periphery of the core 32 and the base 30 are arranged. The core 32 was fixed by applying the adhesive 33 to the gap. Here, the core 32 includes an annular portion 34, a plurality of core teeth 35 projecting radially from the annular portion 34, and a stator coil 36 wound around each of the core teeth 35, as shown in FIG. In the structure shown, the annular portion 34 disposed on the outer periphery of the core 32 and the base 30 are bonded. In FIG. 9, reference numeral 37 denotes a magnet as a rotor, and reference numeral 38 denotes a fitting ring attached to a portion near the outer periphery of the core 32.

  As another core fixing method in a small motor, as shown in FIGS. 10 and 11, the bottom surface of the annular portion 43 on the inner peripheral side of the core teeth 41 and the stator coil 42 in the core 40 is removed from the circuit board. A structure in which the base 44 is bonded via an adhesive 45 is disclosed in Patent Document 1 and the like. In addition, 46 is a magnet as a rotor.

  However, since these structures are only fixed to the cores 32 and 40 from the outer peripheral side or the inner peripheral side, the support strength is not sufficient, and when the motor is driven to rotate, 40 may vibrate and cause vibration, which may reduce reliability when data is read / written by the hard disk device. Further, when vibration occurs, motor noise is likely to be generated, and there is a possibility that various control devices and the like are adversely affected by noise.

  Furthermore, when the stator coils 36 and 42 and the bases 30 and 44 are arranged close to each other in the rotation axis direction so as to further reduce the motor arrangement space, the cores 32 and 40 vibrate and the stator coils 36 and 42 and the base 30 are vibrated. , 44 may come into contact with the stator coils 36, 42, which may reduce the insulation.

  Further, as shown in FIGS. 10 and 11, in the structure in which the bottom surface of the annular portion 43 of the core 40 is bonded to the base 44, when the radial dimension of the annular portion 43 of the core 40 is increased in order to increase the support strength, There is also a drawback that the size of the motor is increased by that amount.

  As a countermeasure against such problems and disadvantages, Patent Document 2 discloses a base (base) 51 and an annular base 53 provided on the inner peripheral side of a core 52, as shown in FIGS. A space surrounded by the core teeth 54, the core tooth support portion 55 of the base 51 that supports the core tooth outer periphery 54 a from below, and the fitting convex portion 56 erected between the core teeth outer periphery 54 a of the base 51, that is, A technique is disclosed in which an adhesive 57 is filled over almost the entire space where the core 52 is disposed. In addition, 58 is a magnet as a rotor, 59 is a stator coil.

According to this structure, the core 52 is sufficiently supported because it is fixed by the adhesive 57 including the core teeth 54 and the wide portion from the annular base 53 surrounding the core 52 from the inside to the outer periphery of the core tooth 54a. As a result, the core 52 can be prevented from vibrating even when the motor is driven to rotate.
JP 2002-281714 A Japanese Patent No. 3317307

  By the way, in order to further reduce the size of the motor, it can be considered that the cores 32, 40, 52 and the magnets 37, 46, 58 are disposed close to each other without providing a partition plate or the like. However, while adopting the arrangement configuration as described above, the adhesive 57 is filled over substantially the entire arrangement space of the core 52 including the space between the core teeth 54 as in the structure shown in FIGS. If the method is adopted, the adhesive 57 may leak from the space where the core 52 is disposed to the space where the magnet 58 is disposed due to the necessity of a relatively large amount of the adhesive 57. In this case, the portion where the adhesive 57 is filled comes into contact with the magnet 58, and the motor cannot be rotated smoothly, or the relative position between the core 52 and the magnet 58 is shifted. The reliability of the motor may be reduced.

  The present invention solves the above problems, and even when the core can be fixed with good support strength, even when the core and the magnet are arranged close to each other without providing a partition plate or the like, it is good. An object of the present invention is to provide a small motor that can maintain high reliability.

  In order to solve the above-mentioned problems, the present invention provides a core stator coil that is disposed close to the base with respect to the axial direction of the motor rotation shaft, and an adhesive is applied to the portion where the stator coil and the base are brought close to each other. It is characterized by being interposed.

  According to this configuration, since the stator coil approaching the base with a relatively large area is bonded and fixed to the base, the core can be fixed with good support strength, and the core can be prevented from vibrating. In addition, since an adhesive is interposed between the stator coil itself and the base, the core does not vibrate so that the stator coil and the base come into contact with each other, and the film of the stator coil does not come off, so that the insulating property is maintained. Secured. In addition, since the base and the stator coil are arranged close to each other, only a small amount of adhesive is required, and when a liquid adhesive is used, the adhesive is excellent due to capillary action only at these close locations. It is easy to adjust the amount of adhesive so that it does not flow to the magnet side while spreading and obtaining good adhesive strength. Therefore, even when the core and the magnet are arranged close to each other without providing a partition plate or the like, it is relatively easy to prevent the adhesive from flowing to the magnet side.

  According to the above configuration, since the stator coil approaching the base with a relatively large area is bonded and fixed to the base, the core can be fixed with good support strength, and the core can be prevented from vibrating. There is no deterioration in reliability when reading / writing data on the hard disk drive due to vibrations, and no motor noise. Further, since the core does not vibrate so that the stator coil and the base do not come into contact with each other and the coat of the stator coil is not removed, insulation is ensured, which improves reliability. Moreover, a small amount of adhesive is required, and it is easy to adjust the amount of adhesive so that it does not flow to the magnet side while obtaining good adhesive strength. Problems are unlikely to occur, and this also improves the reliability of the motor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Although the small motor according to the embodiment of the present invention shows a case where it is used as a spindle motor for a hard disk as an example, it is not limited to this.

  As shown in FIGS. 1-3, in this small motor, the core 3 is arrange | positioned between the base 1 and the motor cover 2, and not only the clearance gap between the outer peripheral part of the core 3 and the base 1, The core 3 is fixed to the base 1 by interposing an adhesive 5 at a location where the stator coil 4 and the base 1 of the core 3 are brought close to each other. Here, the core 3 includes an annular portion 6 disposed on the outer peripheral side, a plurality of core teeth 7 projecting radially inward from the annular portion 6, and a stator coil 4 wound around each core tooth 7. And a fitting ring 9 fitted and mounted inside the annular portion 6, and the stator coil 4 is disposed close to the base 1. In particular, this small motor is different from the conventional small motor shown in FIG.

  As shown in FIGS. 1 and 2, the small motor is of an inner rotor type in which the core 3 is disposed on the outer periphery and the magnet 10 is disposed on the inner side. The magnet 10 is disposed close to the inner peripheral side of the core 3 without providing a partition plate or the like. The magnet 10 is attached to the outer periphery of the hub 12 attached to the rotating shaft 11, and a ball bearing 14 is interposed between the support cylinder 13 attached to the base 1 and the hub 12. The hub 12 and the magnet 10 are rotatably supported. A recording / reproducing disk 19 is attached to the outer periphery of the hub 12.

The procedure for attaching the core 3 in this small motor is as follows.
First, as shown in FIG. 4, the adhesive 5 is applied to a position corresponding to the location of the stator coil 4 of the core 3 in the base 1. Then, the core 3 is placed on the base 1 to which the adhesive 5 is applied. In this case, as shown in FIGS. 1 and 3, the core 3 is configured such that the outer peripheral annular portion 6 is placed on a stepped portion 1 a provided on the base 1. When the annular portion 6 of the core 3 is placed on one stepped portion 1a, the stator coil 4 of the core 3 is disposed so as to approach the base 1 in a posture with a small dimension. Therefore, when the core 3 is placed on the base 1 to which the adhesive 5 is applied, the base 1 and the stator coil 4 are arranged close to each other. The adhesive 5 spreads well due to the capillary phenomenon between them, and the base 1 and the stator coil 4 are well bonded in a relatively wide area. Before placing the core 3 on the base 1, it is desirable to apply the adhesive 5 to a portion of the base 1 that faces the annular portion 6 of the core 3. Even an annular portion 6 is fixed to the base 1 with an adhesive 5. Furthermore, after that, the motor cover 2 is placed on the annular portion 6 of the core 3 placed on the base 1 in a state where the adhesive 5 is applied, and as a result, the outer peripheral portion of the core 3 via the adhesive 5, The portion of the base 1 near this portion, the fitting ring 9 and the motor cover 2 are also bonded to each other.

  As the adhesive 5, it is desirable to use an epoxy adhesive in which two liquids are mixed rather than a one-liquid type epoxy adhesive. According to this, the adhesive between the core 3 and the stator coil 4 is used. Adhesive 5 enters well into narrow gaps between them, and can be bonded well. In addition, although you may use a 1 liquid type epoxy adhesive, in this adhesive, since a main ingredient and a hardening | curing agent are easy to isolate | separate, since only a main ingredient may enter into a narrow crevice, adhesive 5 may not harden, It is necessary to keep this in mind. Although other types of adhesives 5 may be used, the adhesives 5 need to have insulating properties.

  The adhesive 5 is preferably one that can control the application position and the application amount using an automatic application device, but is not limited to this, and can be applied manually using a syringe or the like.

  According to this configuration, the core 3 is not only fixed to the base 1 at the outer peripheral portion thereof but also fixed to the base 1 by being bonded to the base 1 by a portion of the stator coil 4 approaching the base 1 with a relatively large area. Therefore, the core 3 can be fixed with good support strength. Therefore, it is possible to satisfactorily prevent the core 3 from vibrating, in particular, to vibrate in the direction of the rotation axis 0, and the occurrence of vibration does not cause a decrease in reliability when reading / writing data from the hard disk device, and motor noise does not occur.

  Further, since the adhesive 5 is interposed between the stator coil 4 itself and the base 1, the core 3 does not vibrate so that the stator coil 4 and the base 1 come into contact with each other and the film of the stator coil 4 is not removed. Insulation is ensured.

  In addition, since the core 3 and the stator coil 4 are arranged close to each other, only a small amount of the adhesive 5 is required. When the liquid adhesive 5 is used, only the close portions are bonded by capillary action. It is easy to adjust (control) the amount of adhesive so that the agent 5 spreads well and good adhesive strength is obtained, but does not flow to the magnet 10 side. Therefore, even when the core 3 and the magnet 10 are arranged close to each other without providing a partition plate or the like as described above, the adhesive 5 is prevented from flowing to the magnet 10 side. As a result, it is difficult to cause problems such as flow and contact with the adhesive 5 and the magnet 10, and the reliability of the motor is improved.

  However, in order to prevent the adhesive 5 from flowing to the magnet 10 side more reliably, as shown in FIG. 5, a convex overflow prevention rib 15 is provided at the boundary between the stator coil 4 and the magnet 10 in the base 1. It may be provided.

  According to this configuration, even if the adhesive 5 tries to flow into the magnet 10, the flow of the adhesive 5 is blocked by the convex overflow prevention rib 15, and the adhesive 5 is prevented from flowing into the magnet 10. Can be reliably prevented from flowing to the side, further improving the reliability.

Alternatively, as shown in FIG. 6, a concave overflow prevention groove 16 may be provided at the boundary between the stator coil 4 and the magnet 10 in the base 1.
According to this configuration, even if the adhesive 5 tries to flow into the magnet 10, the adhesive 5 flows into the concave overflow prevention groove 16 and the adhesive 5 is disposed on the magnet 10. Reaching the installation location is prevented, which also improves the reliability.

  Moreover, in the said embodiment, the case where the adhesive agent 5 is apply | coated before mounting the core 3 on the base 1 is described, In this case, while being able to apply | coat the adhesive agent 5 very easily, good position Has the advantage that it can be applied. However, the present invention is not limited to this. The core 3 is arranged on the base 1 so that the stator coil 4 approaches the base, and thereafter, the stator coil 4 of the base 1 and the core 3 is used by using an injection syringe or the like. The stator coil 4 may be bonded to the base 1 by filling the adhesive 5 with the adhesive 5 from an oblique direction. In this case, the filling operation is somewhat troublesome, but when the adhesive 5 is filled between the base 1 and the stator coil 4, the injection location is biased between the base 1 and the stator coil 4. Even in the case of the position, the adhesive 5 spreads well in the narrow gap due to the capillary phenomenon, and the base 1 and the stator coil 4 can be favorably bonded also by this.

Further, as shown in FIG. 7, an adhesive tape 17 may be used instead of the adhesive 5. That is, the adhesive tape 17 made of a substantially disk-shaped double-sided tape is applied to a position corresponding to the location of the stator coil 4 of the core 3 in the base 1, and the core 3 is placed on the stepped portion 1 a of the base 1 in this state. Then, the stator coil 4 is bonded onto the adhesive tape 17 in the base 1. Also by this, the core 3 can be fixed with a good support strength and the core 3 can be well prevented from vibrating as in the case where the adhesive 5 is used. Further, since the adhesive tape 17 is interposed between the stator coil 4 itself and the base 1, the core 3 does not vibrate so that the stator coil 4 and the base 1 come into contact with each other and the film of the stator coil 4 is not removed. Insulation is ensured.

  Further, as shown in FIG. 8, a cushion material 18 may be used instead of the adhesive tape 17. That is, the substantially disc-shaped cushion material 18 is attached to the base 1 at a position corresponding to the location of the stator coil 4 of the core 3, and in this state, the core 3 is placed on the base 1 and the outer periphery of the core 3 is attached to the base 1. Fix with adhesive 5. According to this, even when the core 3 vibrates, the vibration is satisfactorily absorbed by the cushion material 18, and as a result, the vibration of the core 3 is minimized. In addition, it is possible to prevent the stator coil 4 from coming into contact with the stator coil 4 and the base 1 due to the vibration of the core 3, and the insulation of the stator coil 4 can be secured.

  In the embodiment shown in FIGS. 1 to 7, the case where not only the location of the stator coil 4 but also the outer peripheral portion of the core 3 is bonded to the base 1 is described. However, the present invention is not limited to this, and can be fixed to the base 1 using the adhesive 5 or the adhesive tape 17 only at the location of the stator coil 4.

  Further, in the above-described embodiment, as a small motor, the case where each of the inner rotor type in which the core 3 composed of the stator coil 4 is disposed on the outer periphery and the magnet 10 is disposed on the inner side is described. The rotor-type small motor has the advantage that the magnet 10 can be arranged closer to the center and can be formed compactly. However, the present invention is not limited to this. In this case, the core and the magnet can be applied close to each other without interposing a partition that separates them. The adhesive can be prevented from flowing to the magnet side.

The small motor of the present invention is suitable for a spindle motor for a hard disk, but can also be applied to various motors such as an optical disk drive and a video tape recorder.

The principal part expanded side sectional view of the small motor which concerns on embodiment of this invention Side sectional view of the small motor Top view showing a state where the core is fixed to the base of the same small motor The top view which shows the state which applied adhesive to the base of the same small motor Side sectional view of a small motor according to another embodiment of the present invention Side surface sectional drawing of the small motor which concerns on other embodiment of this invention. Side sectional view of a small motor according to still another embodiment of the present invention. Side surface sectional drawing of the small motor which concerns on other embodiment of this invention. Expanded side sectional view of the main part of a conventional small motor Side sectional view of other conventional small motors Plan view of the core in the conventional small motor Cross-sectional view of a hard disk using another conventional small motor Plan view of the core of the hard disk using the conventional small motor and its vicinity

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Motor cover 3 Core 4 Stator coil 5 Adhesive 6 Annular part 7 Core tooth 9 Fitting ring 10 Magnet 11 Rotating shaft 12 Hub 15 Overflow prevention rib 16 Overflow prevention groove 17 Adhesive tape 18 Cushion material 19 Disc

Claims (11)

  A small motor characterized in that a core stator coil is disposed close to the base with respect to the axial direction of the motor rotation shaft, and an adhesive is interposed at a position where the stator coil and the base are close to each other.   2. The small motor according to claim 1, wherein a convex overflow prevention rib is provided at a boundary portion between the stator coil and the magnet in the base.   2. A small motor according to claim 1, wherein a concave overflow prevention groove is provided at a boundary between the stator coil and the magnet in the base.   A small motor characterized in that a stator coil of a core is disposed close to a base with respect to an axial direction of a motor rotation shaft, and an adhesive tape is interposed at a position where the stator coil and the base are brought close to each other.   A small motor characterized in that a core stator coil is disposed close to a base with respect to the axial direction of a motor rotation shaft, and a cushion material is interposed at a position where the stator coil and the base are close to each other.   The small motor according to any one of claims 1 to 5, wherein the core and the magnet are arranged close to each other without interposing a partition for partitioning them.   It is an inner rotor type | mold, The small motor of any one of Claims 1-6 characterized by the above-mentioned.   Manufacture of a small motor in which adhesive is applied to the base at a position corresponding to the location of the stator coil, the core is placed on the base and the stator coil is close to the base, and the stator coil is bonded to the base Method.   A method for manufacturing a small motor, in which a core is disposed on a base so that the stator coil is close to the base, an adhesive is filled between the base and the stator coil of the core, and the stator coil is adhered to the base.   A manufacturing method of a small motor in which an adhesive tape made of a double-sided tape is attached to a position corresponding to a stator coil arrangement portion of a core in a base, and a stator coil is bonded onto the adhesive tape in the base.   A manufacturing method of a small motor in which a cushion material is attached to a position corresponding to a stator coil arrangement position of a core in a base, and the core is arranged in a state where the stator coil is placed on the cushion material in the base.

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