JP4278527B2 - Spindle motor - Google Patents

Description

  The present invention relates to a spindle motor that uses a hydrodynamic bearing, and more particularly to a spindle motor that can be suitably used for a hard disk device or the like.

  In spindle motors built in hard disk drives, replacement with fluid bearings with better rotational accuracy than conventional ball bearings is progressing as the storage capacity of hard disks increases.

  As disclosed in Patent Document 1 and the like, a spindle motor of a type in which a fluid bearing is used and a hub is fixed to a sleeve (tubular body) through which a shaft is inserted is already known. FIG. 6 shows a conventional spindle motor of this type, in which a base end portion of a shaft 3 is supported and fixed in a shaft hole 2 formed in the base 1. A cylindrical portion 1 a is formed on the base 1, and a stator core 5 with a winding 4 is attached to the outer periphery of the cylindrical portion 1 a of the base 1.

  The rotor-side hub 6 to which a disk as a magnetic recording medium is attached is fixed in a posture fitted to the outer periphery of the sleeve. In consideration of processability in the production process, the sleeve is composed of an inner sleeve 7 of the inner cylindrical portion and an outer sleeve 8 of the outer cylindrical portion, and the outer sleeve 8 is fitted on the inner sleeve 7 in an attitude. It is fixed. The shaft 3 is inserted into the inner circumference of the inner sleeve 7 to which the hub 6 and the outer sleeve 8 are fixed in this manner via a predetermined gap, and the hub 6 and the sleeve are rotatably supported. An annular magnet 10 is attached to the inner surface of the outer periphery of 6 so as to face the teeth of the stator core 5.

  When assembling the hub 6 to the shaft 3, as shown in FIGS. 7A to 7C, first, the outer sleeve 8 is press-fitted and fixed to the outer periphery of the inner sleeve 7, and then the inner sleeve 7 is fixed. As shown in FIG. 7 (d), the outer sleeve 8 into which is pressed is pressed into the inside of the hub 6 and fixed. Then, the hub 6 assembled with the outer sleeve 8 and the inner sleeve 7 in this way is connected to the thrust surface 11a of the large-diameter flange-shaped flange portion 11 formed in the middle of the shaft 3, and the lower end surface of the inner sleeve 7 is It fits in the state which has a clearance gap in the outer periphery of the shaft 3, so that it may become a mounting attitude | position. Thereafter, the seal member 12 is press-fitted into the outer periphery of the distal end portion of the shaft 3 so as to approach the upper end surface of the inner sleeve 7 inside the outer sleeve 8. 6a and 6b in FIG. 6 are first and second press-fitting portions which are press-fitting locations to the outer sleeve 8 in the hub 6.

  A dynamic pressure generating groove having a herringbone shape or the like is formed on each of the upper side portion and the lower side portion of the inner peripheral surface of the inner sleeve 7, and the dynamic pressure generating grooves are also formed on the upper end surface and the lower end surface of the inner sleeve 7. Has been. Further, gaps are formed at the locations where these dynamic pressure generating grooves face, and the locations where these gaps are provided, that is, the gaps between the outer peripheral surface of the shaft 3 and the inner peripheral surface of the inner sleeve 7 The working fluid 9 such as lubricating oil is filled in the space between the lower end surface of the inner sleeve 7 and the thrust surface 11 a of the flange portion 11 and the space between the upper end surface of the inner sleeve 7 and the seal member 12. Has been. Further, the outer peripheral surface of the seal member 12 and the outer peripheral surface of the flange portion 11 are inclined so as to become thinner upward or downward, and between these inclined surface portions and the inner peripheral surface of the outer sleeve 8 facing the inclined surface portion. Sealing portions 13 and 14 are formed for sealing in a state where the working fluid 9 is accumulated.

  Here, when the winding 4 of the spindle motor is energized, the hub 6, the outer sleeve 8, and the inner sleeve 7 are centered on the shaft 3 with respect to the base 1 by the magnetic action of attraction and repulsion between the teeth of the stator core 5 and the annular magnet 8. As a result of this rotation, the dynamic pressure generating grooves in the respective parts scratch the working fluid 9 to generate dynamic pressure. And the position of the radial direction is controlled to a predetermined gap between the upper and lower portions of the inner peripheral surface of the inner sleeve 7 in which the dynamic pressure generating groove is formed and the outer peripheral surface of the shaft 3 opposed thereto. A position in the thrust direction is formed between the upper end surface of the inner sleeve 7 in which the first and second radial bearings 15 and 16 are formed and the dynamic pressure generating groove is formed, and the lower surface of the seal member 12 facing the inner sleeve 7. A first thrust bearing 17 is formed to control the pressure in a predetermined gap, and a thrust direction 17 is formed between a lower end surface of the inner sleeve 7 in which a dynamic pressure generating groove is formed and a thrust surface 11a of the flange portion 11 facing the first sleeve. A second thrust bearing 18 that controls the position to a predetermined gap is formed.

Therefore, when the hub 6 is rotated, the hub 6 rotates stably and continuously with the working fluid 9 interposed between the inner sleeve 7 and the shaft 3, the seal member 12, and the flange portion 11.
JP 2003-206943 A

  By the way, in this type of conventional spindle motor, as shown in FIG. 6, a first press-fit portion 6a for press-fitting the hub 6 into the outer sleeve 8 is provided at a location above the first radial bearing 15, A second press-fitting portion 6 b for press-fitting the hub 6 into the sleeve 8 is provided at an intermediate height between the first radial bearing 15 and the second radial bearing 16. Therefore, as shown in FIG. 6, in a state where the hub 6 is press-fitted into the outer sleeve 8, the portions that are press-fitted in the outer sleeve 8 are slightly deformed toward the inner diameter side so as to approach the shaft center 3 a of the shaft 3. The intermediate portion 30 between the first radial bearing 15 and the second radial bearing 16 of the inner sleeve 7 corresponding to the deformation of the portion of the outer sleeve 8 corresponding to the second press-fitting portion 6b is provided. Although it is a little, it deform | transforms so that the axial center 3a side of the shaft 3 may be approached.

  As a result, as shown in an exaggerated manner in FIG. 8, the upper radial gap is widened at the location where the first radial bearing 15 is provided, and at the location where the second radial bearing 16 is provided. The gap on the lower side is widened so that the working fluid 9 of the first and second radial bearings 15 and 16 has a low pressure outside (open portions of the seal portions 13 and 14 with respect to the shaft axial direction). As a result, when the hub 6 is driven to rotate, the working fluid 9 jumps out of the seal portions 13 and 14 and causes oil leakage.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spindle motor in which a working fluid such as oil leakage does not flow out to the outside even when a hub is press-fitted into a sleeve.

In order to solve the above-described problems, a spindle motor of the present invention includes a shaft, a sleeve into which the shaft is inserted through a predetermined gap, and two press-fit portions that are arranged on the outer periphery of the sleeve so as to be spaced apart in the axial direction of the shaft. And two dynamic pressures formed on at least one of the outer peripheral surface of the shaft and the inner peripheral surface of the sleeve and disposed between the two press-fit portions and close to the two press-fit portions, respectively. And a working fluid filled between the shaft and the sleeve. When the sleeve rotates with respect to the shaft, a dynamic pressure is applied to the working fluid in cooperation with the dynamic pressure generating groove. Two radial bearings are configured to control the radial position of the sleeve with respect to the shaft to a predetermined gap, and the gap between the shaft and the sleeve in the radial bearing is in the axial direction of the sleeve It characterized in that it is formed to be narrower toward the press-fit portion close from Oite center side.

  With this configuration, when the hub is press-fitted to the outer periphery of the sleeve, the gap at the first and second radial bearings is narrowed toward the both ends of the sleeve by this pressure input, so-called pump-in shape As a result, in the first and second radial bearings, the working fluid tends to flow into a region between the first radial bearing and the second radial bearing, and oil leakage, etc. The working fluid is prevented from flowing out to the outside.

  When the distance from the first press-fit portion to the first radial bearing and the distance from the second press-fit portion to the second radial bearing are different from each other with respect to the axial direction of the shaft, the first press-fit in the sleeve is performed. Even when the deformation amount at the portion and the deformation amount at the second press-fit portion are the same, the smaller the distance, the stronger the deformation force due to the press-fitting at the location facing the radial bearing on the inner peripheral surface of the sleeve, Therefore, the first radial bearing and the second radial bearing have different gradients of inclination, the force for sending the working fluid from the first radial bearing to the second radial bearing side, and the second radial bearing Therefore, the force for sending the working fluid to the first radial bearing side becomes non-uniform, and as a result, the working fluid may flow out to the outside such as oil leakage.

  In order to cope with this, in addition to the above configuration, the sleeve may be provided with a slit for attenuating the transmission force to the radial bearing side due to the press-fitting of the first press-fitting part or the second press-fitting part. In this case, the distance from the press-fit portion to the radial bearing adjacent to the press-fit portion is provided on the side where the distance from the shaft axial direction is small, and this slit is provided in the axial direction distance from the bottom of the slit to the adjacent press-fit portion It is preferable that the depth is equal to the distance in the axial direction of the shaft from the other press-fit portion to the radial bearing adjacent to the press-fit portion.

  According to this configuration, by providing the slit on the side where the distance from the radial bearing in the sleeve to the press-fitting portion in the vicinity thereof is small, by the press-fitting at the location facing the first and second radial bearings on the inner peripheral surface of the sleeve. The deformation force can be made substantially the same, the force for sending the working fluid between the radial bearings can be equalized, and the working fluid can be prevented from flowing out to the outside more reliably, such as oil leakage. .

  According to the present invention, it is possible to prevent the working fluid from flowing out to the outside, such as oil leakage, and the reliability is improved. In particular, in a spindle motor provided with a fluid bearing having openings on both ends of the shaft, oil leakage can be prevented satisfactorily.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated to the thing which has a function similar to the component of the conventional spindle motor shown in FIG.
(Embodiment 1)
1 to 3 show a first embodiment of the present invention, FIG. 1 is a sectional view of a spindle motor, and FIGS. 2A to 2D are procedures for assembling an inner sleeve, an outer sleeve, and a hub, respectively. FIG. 3 is a diagram conceptually showing the flow of the working fluid.

  As shown in FIG. 1, the base end portion of the shaft 3 is supported and fixed in the shaft hole 2 formed in the base 1. In addition, a cylindrical portion 1 a is formed on the base 1, and a stator core 5 provided with a winding 4 is attached to the outer periphery of the cylindrical portion 1 a of the base 1. When the spindle motor is used for a hard disk device, the rotor-side hub 6 has a disk as a magnetic recording medium attached to the outer periphery, and the hub 6 is fixed in a posture fitted to the outer periphery of the sleeve. .

  In this embodiment, in consideration of workability in the production process, the sleeve is composed of an inner sleeve 7 of the inner cylindrical portion and an outer sleeve 8 of the outer cylindrical portion. 8 is fixed in a fitted posture. The shaft 3 is inserted through a predetermined gap into the inner circumference of the inner sleeve 7 to which the hub 6 and the outer sleeve 8 are fixed in this manner, and the hub 6 and the sleeve are pivotally supported. An annular magnet 10 is attached to the inner surface of the part so as to face the teeth of the stator core 5.

  A dynamic pressure generating groove having a herringbone shape or the like is formed on each of the upper side portion and the lower side portion of the inner peripheral surface of the inner sleeve 7, and the dynamic pressure generating grooves are also formed on the upper end surface and the lower end surface of the inner sleeve 7. Has been. Further, gaps are formed at the locations where these dynamic pressure generating grooves face, and the locations where these gaps are provided, that is, the gaps between the outer peripheral surface of the shaft 3 and the inner peripheral surface of the inner sleeve 7 A gap between the lower end surface of the inner sleeve 7 and the thrust surface 11a of the large-diameter flange portion 11 provided on the shaft 3 and a gap between the upper end surface of the inner sleeve 7 and the lower end surface of the seal member 12 are formed. A working fluid 9 such as lubricating oil is filled in the containing space. And the position of the radial direction is controlled to a predetermined gap between the upper and lower portions of the inner peripheral surface of the inner sleeve 7 in which the dynamic pressure generating groove is formed and the outer peripheral surface of the shaft 3 opposed thereto. A position in the thrust direction is formed between the upper end surface of the inner sleeve 7 in which the first and second radial bearings 15 and 16 are formed and the dynamic pressure generating groove is formed, and the lower surface of the seal member 12 facing the inner sleeve 7. A first thrust bearing 17 is formed to control the pressure in a predetermined gap, and a thrust direction 17 is formed between a lower end surface of the inner sleeve 7 in which a dynamic pressure generating groove is formed and a thrust surface 11a of the flange portion 11 facing the first sleeve. A second thrust bearing 18 that controls the position to a predetermined gap is formed.

  Further, the outer peripheral surface of the seal member 12 and the outer peripheral surface of the flange portion 11 are inclined so as to become thinner upward or downward, and between these inclined surface portions and the inner peripheral surface of the outer sleeve 8 facing the inclined surface portion. Sealing portions 13 and 14 are formed for sealing in a state where the working fluid 9 is accumulated. Reference numerals 19 and 20 in FIG. 1 denote dust covers that prevent dust and the like from entering the seal portions 13 and 14 from the outside.

  An outer sleeve 8 is press-fitted to the outer periphery of the inner sleeve 7, and a hub 6 is press-fitted to the outer periphery of the outer sleeve 8 by the first press-fitting portion 6a and the second press-fitting portion 6b that are different from each other in the direction of the shaft axis 3a. ing. Here, the first and second press-fit portions 6a and 6b are located between the first press-fit portion 6a and the second press-fit portion 6b with respect to a direction along the shaft axis 3a (referred to as a shaft axis direction). The first and second radial bearings 15 and 16 are positioned outside the first and second radial bearings 15 and 16 with respect to the shaft axis 3a direction (in the case shown in FIG. 6a is disposed above the first radial bearing 15, and the second press-fit portion 6b is disposed below the second radial bearing 16.

  In the above configuration, when the winding 4 of the spindle motor is energized, the hub 6, the outer sleeve 8, and the inner sleeve 7 are centered on the shaft 3 with respect to the base 1 by the magnetic action of attraction and repulsion between the teeth of the stator core 5 and the annular magnet 8. As a result of this rotation, the dynamic pressure generating grooves in each part scrape the working fluid 9 to generate dynamic pressure, and the inner sleeve 7 is moved in the radial direction by the first and second radial bearings 15 and 16 with respect to the shaft 3. While the position is controlled to a predetermined gap, and the inner sleeve 7 is controlled by the first and second thrust bearings 17 and 18 with respect to the seal member 12 and the flange portion 11, the position in the thrust direction is controlled to the predetermined gap, the hub 6 Rotates stably and continuously.

  In assembling the hub 6 to the shaft 3 in the production process of the spindle motor, first, as shown in FIGS. 2A to 2C, the outer sleeve 8 is first press-fitted into the outer periphery of the inner sleeve 7 and fixed. Next, the outer sleeve 8 into which the inner sleeve 7 is press-fitted is press-fitted inside the hub 6 and fixed as shown in FIG. Then, the hub 6 assembled with the outer sleeve 8 and the inner sleeve 7 in this way is placed on the thrust surface 11a of the thick and flanged flange portion 11 formed in the middle of the shaft 3, and the lower end surface of the inner sleeve 7 Is fitted in a state having a gap on the outer periphery of the shaft 3 so as to be in a posture to be mounted. Thereafter, the seal member 12 is press-fitted into the outer periphery of the distal end portion of the shaft 3 so as to approach the upper end surface of the inner sleeve 7 inside the outer sleeve 8.

  Here, in this spindle motor, as shown in FIG. 1 and as described above, the first and second press-fitting portions 6a and 6b of the hub 6 press-fitted into the outer sleeve 8 are first press-fitted in the shaft axial direction. The first and second radial bearings 15 and 16 are located outside of the first and second radial bearings 15 and 16 so that the first and second radial bearings 15 and 16 are positioned between the portion 6a and the second press-fit portion 6b. Is arranged. Therefore, as shown in FIG. 1, in the state in which the hub 6 is press-fitted into the outer sleeve 8, the first and second radials in the inner sleeve 7 near these press-fitting locations are accompanied by deformation of the press-fitting locations in the outer sleeve 8. As the bearings 15 and 16 are exaggerated in FIG. 3, the first radial bearing 15 is deformed to the inner diameter side so that the upper side is close to the shaft axis 3 a, and there is a gap in the lower part. In addition, the second radial bearing 16 is deformed toward the inner diameter side so that the lower side is close to the shaft axis 3a, and the upper gap is widened. As a result, the working fluid 9 of the first and second radial bearings 15 and 16 has a so-called pump-in shape that flows into the low pressure inside (the side between the seal portions 13 and 14 with respect to the shaft axial direction). As a result, even when the hub 6 is rotationally driven, the working fluid 9 does not jump out of the seal portions 13 and 14, and oil leakage is less likely to occur. Thereby, the reliability as a spindle motor improves.

  In this embodiment, the case where the dynamic pressure generating grooves of the radial bearings 15 and 16 are formed on the inner peripheral surface of the inner sleeve 7 is described. However, the present invention is not limited to this. The present invention can be applied to those formed on at least one of the outer peripheral surface of the shaft 3 and the inner peripheral surface of the sleeve. Moreover, although the case where the thrust bearings 17 and 18 are provided in the upper side part and the lower side part of the inner sleeve 7 was described, the case where it is formed in the lower surface of the seal member 12 and the thrust surface 11a of the flange part 11 But it can be applied.

(Embodiment 2)
FIG. 4 is a cross-sectional view of a spindle motor according to the second embodiment of the present invention.
In the second embodiment, as shown in FIG. 4, a distance L1 in the axial direction of the shaft from the press-fit portions 6a and 6b to the radial bearings 15 and 16 adjacent to the press-fit portions 6a and 6b in the sleeve. , The slit 21 is provided on the side where L2 is small, that is, in this case, the portion closer to the second radial bearing 16. In this embodiment, the slit 21 is formed by forming a recess having a groove shape in a cross section extending upward from the lower end of the outer peripheral surface of the inner sleeve 7. Further, the slit 21 has a distance L3 from the second press-fit portion 6b to the bottom of the slit 21 with respect to the shaft axial direction equal to a distance L1 from the first press-fit portion 6b to the first radial bearing 15. It is formed with depth.

  As described in the first embodiment, the first press-fit portion 6a and the second press-fit portion 6b are arranged between the first and second radial bearings 15 and 16 with respect to the shaft axial direction. By arranging so as to be positioned, there is an advantage that the shape of the gap in the first and second radial bearings 15 and 16 becomes a pump-in shape, and oil leakage hardly occurs.

  However, as shown in FIG. 4, the distance L1 from the first press-fit portion 6a to the first radial bearing 15 in the direction of the shaft axis 3a, and the distance L2 from the second press-fit portion 6b to the second radial bearing 16 Are different from each other, the second radial bearing 16 having a smaller separation distance L1 and L2 is more strongly affected by the press-fitting from the second press-fitting part 6a and the press-fitting part 6b. In the configuration not provided), the second radial bearing 16 having the smaller separation distances L1 and L2 has a larger deformation amount at this portion, and the working fluid is moved from the second radial bearing 16 to the first radial bearing 15 side. 9 is larger than the force of flowing the working fluid 9 from the first radial bearing 15 to the second radial bearing 16 side, and the seal member 12 is provided. The working fluid 9 from the pole tip 13 is likely to leak.

  In response to this, in the present embodiment, as shown in FIG. 4, the slit 21 is provided by forming the slit 21 on the lower side where the separation distance between the press-fit portion and the radial bearing in the inner sleeve 7 is small. The deforming force due to the press-fitting from the outer sleeve 8 is not transmitted to the inner sleeve 7 at the portion where the second press-fit portion 6b is pressed into the second radial bearing 15b. Communicated. In addition, the distance L3 from the second press-fit portion 6b to the bottom of the slit 21 with respect to the shaft axial direction of the slit 21 is equivalent to the distance L1 from the first press-fit portion 6b to the first radial bearing 15. Since the inner sleeve 7 is formed with a depth, the amount of deformation at the location of the first radial bearing 15 in the inner sleeve 7 and the amount of deformation at the location of the second radial bearing 16 are substantially the same, and these radial bearings. The pump-in forces at 15 and 16 are also equal and balanced. Thereby, even when the hub 6 is rotationally driven, the working fluid 9 can be more reliably prevented from jumping out of the seal portions 13 and 14, and oil leakage can be reliably prevented. Thereby, the reliability as a spindle motor further improves.

  In the above configuration, the case where the slit 21 is formed by forming a recess having a cross-sectional groove shape extending upward from the lower end of the outer peripheral surface of the inner sleeve 7 is described, but the invention is not limited thereto. A slit may be formed by forming a recess on the inner peripheral surface of the outer sleeve side 8. Further, as shown in FIG. 5, the sleeve may be integrally formed without being divided into the inner sleeve 7 and the outer sleeve side 8, and the same effect can be obtained even if the slit 21 is formed in the sleeve 25. be able to.

  Further, depending on the shape of the sleeve, it is possible to adjust not only the depth of the slit 21 but also the notch width in the radial direction, or to provide slits on both the upper and lower sides of the sleeve. When slits are provided on both sides of the upper and lower portions of the sleeve, the slits may be formed at such a depth that the shaft axial distance from the bottom of each slit to the adjacent press-fit portion is equal.

  In addition, by forming the slits 21 as described above, oil leakage can be prevented particularly well in a so-called tide type (both-end type) spindle motor provided with fluid bearings having openings on both ends of the shaft 3. it can.

  The present invention can be used for various spindle motors that rotate other rotating bodies in addition to a spindle motor for a hard disk drive.

Sectional drawing of the spindle motor which concerns on the 1st Embodiment of this invention (A)-(d) is a figure which shows the process of the assembly | attachment procedure of the inner sleeve, outer sleeve, and hub in the spindle motor, respectively. A diagram conceptually showing the flow of working fluid in the spindle motor Sectional drawing of the spindle motor which concerns on the 2nd Embodiment of this invention Sectional drawing of the other spindle motor based on the 2nd Embodiment of this invention Cross section of a conventional spindle motor (A)-(d) is a figure which shows the process of the assembly | attachment procedure of the inner sleeve, outer sleeve, and hub in the conventional spindle motor, respectively. The figure which shows notionally the flow of the working fluid in the same conventional spindle motor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 3 Shaft 3a Shaft axial center 4 Winding 5 Stator core 6 Hub 6a 1st press-fit part 6b 2nd press-fit part 7 Inner sleeve 8 Outer sleeve 9 Working fluid 10 Annular magnet 11 Flange part 12 Seal member 13, 14 Seal part 15 1st 1 radial bearing 16 second radial bearing 17 first thrust bearing 18 second thrust bearing 21 slit 25 sleeve

Claims (9)

A shaft,
A sleeve into which the shaft is inserted through a predetermined gap;
A hub press-fitted on the outer periphery of the sleeve by two press-fitting portions arranged apart from each other in the shaft axial direction;
Two dynamic pressure generating grooves formed on at least one of the outer peripheral surface of the shaft and the inner peripheral surface of the sleeve, and disposed between the two press-fit portions and close to the two press-fit portions, respectively. ,
A working fluid filled between the shaft and the sleeve,
By rotating the sleeve with respect to the shaft, a dynamic pressure is generated with respect to the working fluid in cooperation with the dynamic pressure generating groove, and the radial position of the sleeve with respect to the shaft is controlled to a predetermined gap. Two radial bearings are configured,
A spindle motor , wherein a clearance between the shaft and the sleeve in the radial bearing is formed so as to become narrower from a central portion side toward the close press-fitting portion side in a shaft axial direction of the sleeve . 2. The spindle motor according to claim 1 , wherein the two radial bearings are spaced apart from the two press-fit portions in the shaft axial direction . 3. The spindle according to claim 1, wherein at least one slit is provided on the sleeve between the press-fit portion and the radial bearing to attenuate a transmission force to the radial bearing due to the press-fit of the press-fit portion. motor. The spindle motor according to claim 3, wherein the slit is provided on one side where a shaft axial distance between the press-fitting portion and the radial bearing adjacent thereto is small . The slit has a shaft axial direction distance from the bottom thereof to the one side press-fitting part, and is equal to a shaft axial direction distance between the other side press-fitting part and the radial bearing adjacent thereto. The spindle motor according to claim 4 , wherein the spindle motor is formed on the sleeve at a depth . The spindle motor according to claim 1, wherein the sleeve includes an inner sleeve and an outer sleeve . The thick shaft flange portion is formed on the shaft, and a thrust bearing is formed between the flange portion of the shaft and one end face of the inner peripheral portion of the sleeve. Spindle motor as described in The spindle motor according to any one of claims 1 to 7 , wherein a seal member is disposed so as to face an end face on one side of the inner peripheral portion of the sleeve . A hard disk device using the spindle motor according to claim 1.

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