JP2009153310A - Spindle motor, information device using the same, and method of manufacturing spindle motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a both end support spindle motor which is improved by precisely suppressing height and tilting of a rotor hub regarding a spindle motor using a fluid bearing for an information device such as an HDD (hard disk drive). <P>SOLUTION: A fist reference surface 8c and second reference surfaces 6b1, 6b2, 6b3 for suppressing the tilting of a disk mounting surface are formed at the rotor hub 8 and a base 6, respectively, and a space between a shaft-side helical groove 7a and a base-side helical groove 6a is filled with an adhesive for fixing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spindle motor using a fluid bearing used in an information device such as an HDD (Hard Disk Drive), an information device using the same, and a method of manufacturing the spindle motor.

2. Description of the Related Art In recent years, various information devices equipped with HDDs have been made lighter, thinner and smaller for convenience of carrying.
On the other hand, it is necessary to maintain and improve high storage capacity and improve impact resistance despite its small size. As a spindle motor bearing used in such an HDD, a fluid bearing having high rotational accuracy and excellent impact resistance is used.

The fluid dynamic bearing is configured to fill a lubricating fluid between the fixed portion and the rotating portion, and generate dynamic pressure in the bearing portion when the rotating portion rotates to support the rotating portion via the lubricating fluid. Further, in a product with a large storage capacity and a large number of disks, it is necessary to further increase the rigidity of the HDD, and both-end supported fluid bearings are used in which both ends of the shaft are fixed to the base and the cover, respectively. (For example, see Patent Document 1 below)
JP 2007-122768 A

  The above-mentioned Patent Document 1 discloses a configuration in which a shaft is used as a base for press-fitting adhesion with a fluid bearing supported at both ends. However, since the shaft is press-fitted and bonded to the through hole of the base, the shaft is inevitably inclined. In other words, the shaft and the base hole are not perfect circles, but distortion due to processing strain, etc. remains, and when the shaft is press-fitted, the shaft is inserted while the outer peripheral surface of the shaft is in contact with the inner peripheral surface of the base hole and plastically deformed. To go. And since this plastic deformation is not uniform all around the inner periphery of the base hole, the shaft is inclined.

  When the shaft is tilted, the sleeve rotatably supported by the shaft and the rotor hub fixed to the sleeve are also affected and tilted.

  Accordingly, there is a problem that the recording disk fixed to the rotor hub is not accurately fixed due to the inclination of the rotor hub, and the rotational accuracy required for the information device cannot be obtained.

  Accordingly, an object of the present invention is to provide a spindle motor that is supported at both ends and that can accurately suppress the inclination of the rotor hub.

  In order to achieve this object, the spindle motor of the present invention has a base provided with a screw-shaped base-side spiral groove and a screw-shaped shaft-side spiral groove that is screwed into the base-side spiral groove on one end side. A shaft having a disk, a sleeve provided so as to be relatively rotatable with respect to the shaft, a rotor hub fixed to the sleeve and having a disk placement surface, and an inclination suppression of the disk placement surface provided on the rotor hub. A first reference surface, a second reference surface for suppressing inclination of the disk mounting surface provided on the base, a gap formed between the shaft-side spiral groove and the base-side spiral groove, and An adhesive filled in the gap is provided.

  As described above, according to the present invention, the rotor hub and the base are respectively provided with the first reference surface and the second reference surface for suppressing the inclination of the disk mounting surface, and the adhesive is provided in the gap between the shaft-side spiral groove and the base-side spiral groove. Therefore, it is possible to provide a spindle motor that is supported at both ends and that can accurately suppress the inclination of the rotor hub.

  Furthermore, since the height can be adjusted while screwing the shaft side spiral groove and the base side spiral groove, the height from the base reference surface of the rotor hub can also be accurately positioned. Further, by adhering in the gap between the screwed spiral grooves, the bonding area can be increased, and strong fastening with a wedge effect can be realized.

  Hereinafter, embodiments of a hydrodynamic bearing device and a spindle motor according to the present invention will be described with reference to the drawings. In the following description, for the sake of convenience, the vertical direction of the drawing is expressed as “axially upper side”, “axially lower side”, etc., but the actual usage state of the spindle motor is not limited.

(Embodiment 1)
FIG. 1 shows an HDD (information device) 3 on which a spindle motor 2 including a hydrodynamic bearing device 1 according to Embodiment 1 of the present invention is mounted.

[Configuration of HDD 3 as a whole]
As shown in FIG. 1, the HDD 3 according to the present embodiment has a head unit 4 and a spindle motor 2 mounted therein. Each recording / reproducing head 4a writes information to the disk (recording medium) 5 or reproduces already written information.

  The head unit 4 is equipped with a plurality of recording / reproducing heads 4 a and is disposed so as to be close to the front and back surfaces of the disk 5.

  The disk 5 is a disk-shaped recording medium having a diameter attached to the HDD 3 of, for example, 0.85 inch, 1.0 inch, 1.8 inch, 2.5 inch, or 3.5 inch.

  The base 6 is formed by processing an aluminum alloy casting, and the front and back surfaces are formed by electrodeposition coating to form the stationary side portion of the spindle motor 2 and the sealed housing of the HDD 3. Part of it.

  The base 6 has a female screw-shaped base-side spiral groove 6a in the vicinity of the central portion thereof, and the hydrodynamic bearing device 1 is provided with a male-thread-shaped shaft-side spiral groove 7a provided at the lower end portion of the shaft 7 of the fluid bearing device 1. It is fixed in a state where it is screwed and filled with an adhesive. A rotor hub 8 is attached to the sleeve 9 on the rotating side of the hydrodynamic bearing device 1.

  The rotor hub 8 is formed in a substantially inverted cup shape with magnetic stainless steel, and is fitted to the upper end of the outer periphery of the cylindrical sleeve 9 of the hydrodynamic bearing device 1, and is fixed to the sleeve 9 by adhesion, press fitting, or the like. Rotate together.

  In addition, the rotor hub 8 has a central hole 8a inserted into the outer peripheral upper end portion of the sleeve 9, a magnet holding portion 8b which is a cylindrical hanging wall to which the rotor magnet 10 is attached, and a disc-like disk 5 mounted thereon. And a circular stepped disk mounting surface 8c.

  On the surface of the base 6, a thin ring-shaped magnetic plate 11 that attracts the rotor magnet 10 is attached so as to face the rotor magnet 10 fixed to the magnet holding portion 8 b in the axial direction.

  In the present embodiment, the base side spiral groove 6a side is described as an internal thread shape, and the shaft side spiral groove 7a is described as an external thread shape. However, the present invention is not limited to this.

  The spindle motor 2 is a device that serves as a rotational drive source for rotationally driving the disk 5, and includes a rotor magnet 10, a stator core 12, a stator coil 13, a bearing portion (fluid bearing device) 1, and the like.

[Description of each member constituting the spindle motor 2]
The rotor magnet 10 is an annular member in which adjacent magnetic poles are alternately arranged with N and S poles, and is formed of an Nd—Fe—B resin magnet or the like.

  The rotor magnet 10 is attached to the magnet holding portion 8b of the rotor hub 8 via a fixed gap in the radial direction with the stator core 12, and is fixed by adhesion or caulking.

  The stator core 12 has a plurality of salient pole portions arranged at substantially equal angular intervals along the circumferential direction, and a stator coil 13 is wound around each of the salient pole portions.

  The stator core 12 applies a rotational force to the rotor magnet 10 by a magnetic field generated by passing a current through the stator coil 13.

  The hydrodynamic bearing device 1 is a hydrodynamic bearing device included in the spindle motor 2 and is disposed near the center of the spindle motor 2.

[Description of each member constituting the hydrodynamic bearing device 1]
As shown in FIG. 2, the hydrodynamic bearing device 1 is a hydrodynamic bearing device of both ends open type in which both ends of a substantially cylindrical sleeve 9 are opened, and includes a shaft 7 and a sleeve 9. The hydrodynamic bearing device 1 is a fixed shaft type hydrodynamic bearing device in which a sleeve 9 as a rotating body rotates around a fixed shaft 7.

  The shaft 7 is a cylindrical member on the fixed side of the hydrodynamic bearing device 1, and is relatively rotatable through a minute gap with an inner peripheral surface of a through hole provided on the inner peripheral side of the sleeve 9. Is arranged. A herringbone-shaped radial dynamic pressure groove (not shown) is formed on the inner peripheral surface of the sleeve 9 or the outer peripheral surface of the shaft 7. For example, the material of the shaft 7 is austenitic stainless steel, and the material of the sleeve 9 is a copper alloy formed by electroless nickel plating.

  Further, the radial dynamic pressure groove is not limited to the herringbone shape, and may be, for example, a spiral shape.

  An annular first seal member 14 and an annular second seal member 15 are fixed to both ends of the shaft 7 by, for example, adhesive press-fitting so as to sandwich the sleeve 9 therebetween.

  And the circular recessed part is provided in one end surface which is the axial direction upper side of FIG. 2 of the sleeve 9, and it has the structure in which the 1st seal member 14 is located in a recessed part. The bottom surface 9a of the concave portion of the sleeve 9 and the end surface 14a of the first seal member are arranged so as to face each other through a minute gap. Further, a herringbone-shaped first thrust dynamic pressure generating groove (not shown) is formed on the bottom surface 9a of the concave portion of the sleeve 9 or the end surface 14a of the first seal member, for example, by etching or the like.

  Similarly, the other end face on the lower side in the axial direction of the sleeve 9 is provided with a circular recess, the second seal member 15 is located in the recess, and the bottom surface 9b of the recess of the sleeve 9 and the second seal member The end faces 15a are arranged so as to face each other through a minute gap. A second thrust dynamic pressure generating groove (not shown) is formed in the bottom surface 9b of the recess of the sleeve 9 or the end surface 15a of the second seal member.

  Here, the radial gap between the inner circumference 9c of the concave portion on the upper side in the axial direction of the sleeve 9 and the outer circumference 14b of the first seal member 14 increases toward the open end side (the upper side in the axial direction in FIG. 2) of the sleeve 9. The first liquid surface 16a of the lubricating fluid 16 is held in the tapered portion by capillary force. Further, the radial gap between the inner circumference 9d of the concave portion on the lower side in the axial direction of the sleeve 9 and the outer circumference 15b of the second seal member 15 becomes larger toward the open end side (lower side in the axial direction in FIG. 2) of the sleeve 9. The tapered shape is increased, and the second liquid surface 16b of the lubricating fluid 16 is held in the tapered portion by a capillary force.

  In addition, in FIG. 2 explaining this embodiment, although the shape which provides the inclined surface which forms a taper part in each radial direction outer periphery of the 1st seal member 14 and the 2nd seal member 15 is shown, it is limited to this Is not to be done. Even if the inclined surfaces are provided on the inner periphery 9c and 9d side of the concave portion of the sleeve 9 in which the first seal member 14 and the second seal member 15 are accommodated, it is possible to obtain the effect of holding the lubricating fluid 16 in the same manner. Needless to say.

  In the sleeve 9, the end surface forming the first thrust dynamic pressure generating groove and the end surface forming the second thrust dynamic pressure generating groove are communicated with each other through the communication path 17.

  Further, an axially upper end portion of the shaft 7 has a female screw portion 7b for fastening with a cover (not shown), and an axially lower end portion is a male screw shape that is screwed with the base 6 shown in FIG. The shaft side spiral groove 7a is provided.

Also, as shown in FIG. 3, the rotor unit 18 is formed by fixing the rotor hub 8 on the axially upper side of the outer periphery of the sleeve 7 by, for example, adhesive press fitting.
[Description of method of attaching rotor unit 18 to base 6]
Next, a method for attaching the rotor unit 18 to the base 6 will be described with reference to FIGS.

  As shown in FIG. 4, the disk mounting surface 8 c that is the first reference surface of the rotor hub 8 is in contact with the jig-side first reference surface 19 a of the positioning jig 19. The air is sucked from the holes 19b and 19c so as to be temporarily contacted and fixed to the positioning jig 19. A jig-side second reference surface 19 d is provided at a distance L from the jig-side first reference surface 19 a of the positioning jig 19. Note that the jig-side first reference surface 19a and the jig-side second reference surface 19d are the same surface, and are polished with high accuracy so that, for example, parallelism and surface roughness are 1 μm or less. Further, when the base 6 is fixed, the jig-side second reference surface 19d comes into contact with, for example, reference surface convex portions 6b1, 6b2, and 6b3 that are the second reference surfaces of the three bases 6 shown in FIG. Note that the positions of the reference surface protrusions 6b1, 6b2, 6b3 are such that the center of gravity of the base unit composed of the base 6, the stator core 12 and the stator coil 13 is located inside the circles passing through the respective outer peripheries as shown in FIG. In addition, it is preferable that the heights of the reference surface protrusions 6b1, 6b2, and 6b3 are the same. As a result, the jig-side second reference surface 19d of the positioning jig 19 can be made the same plane, so that processing is easy and it is easy to ensure processing accuracy. Further, the female screw portion 7 b side of the shaft 7 is fastened by a fastening jig 20. The fastening jig 20 has an alignment function and is held by the positioning jig 19 in a rotatable state.

  Here, for example, an epoxy adhesive that produces an initial anaerobic effect is applied to the base-side spiral groove 6a after one minute from the application.

  Next, as shown in FIG. 4, the base 6 is lowered from the upper side in the axial direction toward the rotor hub 8 so that the center of the base side spiral groove 6 a is positioned at the center of the shaft 7. Then, as shown in FIG. 6A, to the position where the tip of the male screw-shaped spiral groove 7 a provided at one end of the shaft 7 and the groove end of the base-side spiral groove 6 a provided at the center of the base 6 abut. Lower the base 6.

  Here, as shown in FIG. 6B, the shaft 7 is rotated by rotating the fastening jig 20, and the position of the base 6 is changed while the shaft-side spiral groove 7a is screwed into the base-side spiral groove 6a. Approaching the rotor hub 8

  When the fastening jig 20 is further rotated, as shown in FIG. 7A, for example, to a position where a part of the reference surface convex portion 6b1 starts to contact the jig side second reference surface 19d of the positioning jig 19 The base 6 approaches the rotor hub 8. At this time, the positional relationship between the shaft-side spiral groove 7a and the base-side spiral groove 6a is as shown in FIG. As shown in FIG. 8 (a), the weight of the base 6 receives the lower inclined surface in the axial direction of the screw thread of the base side spiral groove 6a on the upper inclined surface in the axial direction of the screw thread of the shaft side spiral groove 7a. It has become. The adhesive 21 is interposed in the gap between the base side spiral groove 6a and the shaft side spiral groove 7a.

  In this state, only the reference surface protrusion 6b1 among the base reference surface protrusions 6b1, 6b2, and 6b3 in FIG. 5 is connected to the jig-side second reference surface 19d of the positioning jig 19 as shown in FIG. They are in contact with each other and are not in contact with the other reference surface convex portions 6b2 and 6b3.

  Further, when the fastening jig 20 shown in FIG. 7A is rotated, as shown in FIG. 7B, all the surfaces of the base reference surface convex portions 6b1, 6b2, and 6b3 are fixed to the jig side second reference surface. Contact 19d. In this state, the rotation of the fastening jig 20 is stopped. In this state, the base reference surfaces 6b1, 6b2, and 6b3 are in contact with the jig-side second reference surface 19d, and the reference surface formed by the reference surface convex portions 6b1, 6b2, and 6b3 and the jig-side second reference surface 19d are equal inclined surfaces. Can be. The positional relationship between the shaft-side spiral groove 7a and the base-side spiral groove 6a in this state is such that the shaft-side spiral groove 7a and the base-side spiral groove 6a are hardly in contact with each other as shown in FIG. 21 is interposed between the base-side spiral groove 6a and the shaft 7a. Further, the total length of the shaft-side spiral groove 7a is longer than the total length of the base-side spiral groove 6a, so that the base-side spiral groove 6a and the shaft-side spiral groove 7a are not fixed by tightening even when the base 6 reaches a predetermined position. It has become. That is, the state where the shaft 7 has a certain play with respect to the base 6 is maintained. The length of the base-side spiral groove 6a is preferably set to be 30 μm or longer in consideration of errors in jigs and products.

  When the base 6 is held in a state where the height and inclination of the base 6 and the rotor hub 8 are regulated by the positioning jig 19 as shown in FIG. 7B, the adhesive 21 in FIG. Curing can be started by the anaerobic effect, and the disk can be cured while keeping the height and inclination of the disk mounting surface 8c of the rotor hub 6 shown in FIG.

  Next, a method for measuring the inclination of the rotor hub 8 of the spindle motor after completion will be described with reference to FIG. For example, the diameter D of the disk mounting surface 8c of the 3.5-inch motor is approximately φ30 mm. First, the height of the point A on the disk mounting surface 8c is measured based on the base 6. Thereafter, the rotor hub is rotated 180 degrees, the height is measured in the same manner at the point B on the opposite side, and the difference between the values is set as the value of the inclination. The measurement is performed by slightly pressing the rotor hub 8 from the upper side in the axial direction so that the rotor hub 8 does not tilt in the gap in the bearing. FIG. 9B shows a comparison of the inclination of the rotor hub in the spindle motor of the present invention and the conventional spindle motor. The horizontal axis represents the value of the rotor hub inclination, and the vertical axis represents the number of rotor hubs. As shown in FIG. 9 (b), it was confirmed that the inclination of the average 20 μm and the maximum 40 μm in the conventional motor was improved to the average 5 μm and the maximum 10 μm or less in the spindle motor of the present invention. For example, in a 3.5-inch HDD, it is desirable that the inclination of the rotor hub be 30 μm or less. In order to increase the capacity in the future, it is expected that the inclination value will be further reduced.

  As described above, according to the spindle motor of the present embodiment, as shown in FIG. 7B, the disk mounting surface is placed on the base while the shaft side spiral groove 7a and the base side spiral groove 6a are screwed together. By positioning and fixing, the height and inclination of the rotor hub 8 with respect to the base 6 can be accurately fixed. Further, as shown in FIG. 8B, the adhesive area in the gap between the base-side spiral groove 6a and the shaft-side spiral groove 7a can be secured, and the shaft 7 and the base even when a high impact is applied due to the wedge effect. The fastening strength of 6 can be maintained. The information device using the spindle motor of the present embodiment can be a product that is excellent in impact resistance and can prevent a signal failure due to a disc swing even if it is thin.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

(A)
In the above embodiment, an epoxy-based adhesive is used as the adhesive 21 applied to the base-side spiral groove 6a in FIG. 8B. However, the present invention is not limited to this.

  For example, an adhesive having a conductive effect may be included. In this case, not only can the same effect as in the first embodiment be obtained, but also a conductive effect can be obtained even if the metal contact portion of the base 6 and the shaft 7 is separated due to a temperature change or the like. The effect that can be removed can be obtained.

(B)
In the above embodiment, the base-side spiral groove 6a and the shaft-side spiral groove 7a are screwed together when the shaft 7 is rotated clockwise as indicated by an arrow shown in FIG. 6B. However, the present invention is not limited to this. It is not done.

  You may comprise so that the base side spiral groove 6a and the shaft side spiral groove 7a may screw together counterclockwise.

  In this case, the same effect as in the first embodiment can be obtained. In addition, it is more preferable that the thrust dynamic pressure generating groove is configured in such a direction that no dynamic pressure is generated when the shaft 7 is rotated, because the dynamic pressure groove is not damaged.

(C)
In the above embodiment, as shown in FIG. 8B, a plurality of spiral grooves of the base side spiral groove 6a and the shaft side spiral groove 7a are provided, but the present invention is not limited to this.

  For example, a spiral groove having a large lead angle may be used.

  In this case, the base 6 can be brought to a predetermined position in a shorter time, and the same effect as in the first embodiment can be obtained.

(D)
In the above embodiment, the shaft 7 that supports both ends is described as a fixed shaft fixing motor as shown in FIG. 1, but the present invention is not limited to this.

  A shaft rotating motor in which the rotor hub 23 is fixed to the shaft 22 as shown in FIG.

  The disk mounting surface 23a of the rotor hub 23 is received by the positioning jig 24, and the base 25 is lowered from the upper side in the axial direction. The female-side base-side spiral groove 25a and the sleeve-side male-side sleeve-side spiral of the sleeve 26 are provided. The groove 26a is brought into contact. Thereafter, by rotating the fastening jig 27, the base-side spiral groove 25 a and the sleeve-side spiral groove 26 a are fitted to contact the base reference surface convex portions 25 b 1, 25 b 2, 25 b 3 and the reference surface 24 a of the positioning jig 24. Fix in place.

  As a result, the disk mounting height and inclination of the rotor hub 23 with respect to the base 25 can be accurately fixed even with the shaft rotation motor, and the same effect as in the first embodiment can be obtained.

(E)
In the above embodiment, the rotor hub 8 is temporarily fixed by sucking air as the fixing to the positioning jig 19 as shown in FIG. 4, but is not limited to this.

  For example, as shown in FIG. 11A, the rotor hub 8 may be attached by attracting with the permanent magnet 27, and removed by pushing the rotor hub 8 with the pin 28. Further, the rotor hub 8 made of a magnetic material may be attracted and fixed by passing an electric current through the coil 29 shown in FIG. 11B and using the positioning jig 30 as an electromagnet.

  In this case, the influence of the air suction on the lubricating fluid inside the bearing can be eliminated, and the same effect as in the first embodiment can be obtained.

(F)
In the above embodiment, as shown in FIG. 5, the three reference surface protrusions 6 b 1, 6 b 2, and 6 b 3 are provided on the base 6 side as the second reference surface. However, the present invention is not limited to this.

  For example, as shown in FIG. 12A, the base 31 may be provided with two wide reference surface convex portions 31a1 and 31a2. Moreover, you may provide the one reference surface convex part 32a in the perimeter of the base 32 like FIG.12 (b).

  Also in these cases, as shown in FIG. 7B, the disk mounting surface 8c, which is the first reference surface, is positioned with respect to the base while the shaft side spiral groove 7a and the base side spiral groove 6a are screwed together. Thus, the same effect as that of the above embodiment in which the height and inclination of the rotor hub 8 with respect to the base 6 can be fixed with high accuracy can be obtained.

(G)
In the above embodiment, as shown in FIG. 4, the disc mounting surface which is the first reference surface by separating the jig side first reference surface 19 a and the jig side second reference surface 19 d of the positioning jig 19 by a distance L. Although 8c was positioned horizontally with respect to the base reference surface convex portion 6b1 as the second reference surface, the present invention is not limited to this.

  As shown in FIG. 13, for example, the distance between the jig-side first reference surface 34a1 and the jig-side second reference surface 34b1 on the reference surface convex portion 33a1 side is L1, and the jig-side first on the reference surface convex portion 33a2 side is set. The disc mounting surface 35a of the rotor hub 35 may be inclined and attached to the base reference surface convex portions 33a1 and 33a2 by setting the distance between the first reference surface 34a2 and the jig-side second reference surface 34b2 to L2.

  For example, when the head signal is more stable when the head 4a is inclined with respect to the disk 5 shown in FIG. 1, the rotor hub 8 with respect to the base 6 can be fixed with high accuracy.

(H)
In the above embodiment, as illustrated in FIG. 1, the spindle motor used in the HDD device as the information device has been described with reference to an example in which the present invention is applied. However, the present invention is not limited to this.

  For example, as a device on which the spindle motor of this embodiment is mounted, in addition to the HDD, a magneto-optical disk device, an optical disk device, a floppy (registered trademark) disk device, a laser printer device, a laser scanner device, a video cassette recorder device, a data streamer device. It can be mounted on a device or the like.

  The spindle motor according to the present invention, the information device including the spindle motor, and the spindle motor manufacturing method can accurately suppress the height and inclination of the rotor hub on which the disk is mounted, and can further improve the fastening strength. It is useful for information devices such as HDDs that are becoming thinner, smaller, and higher capacity.

Sectional drawing of the spindle motor in Embodiment 1 of this invention Sectional drawing of the hydrodynamic bearing apparatus in Embodiment 1 of this invention Sectional drawing of the rotor unit in Embodiment 1 of this invention Explanatory drawing of the attachment method to the base of the rotor unit in Embodiment 1 of this invention The top view which shows the reference plane of the base in Embodiment 1 of this invention (A) is sectional drawing of the state which the base and the shaft contact | abutted with the jig | tool to the base of the rotor unit in Embodiment 1 of this invention, (b) is the base of the rotor unit in Embodiment 1 of this invention. Sectional view of the base and shaft being screwed together with the mounting jig (A) is sectional drawing of the state which the base began to contact | abut with the jig | tool with the attachment tool to the base of the rotor unit in Embodiment 1 of this invention, (b) is the rotor unit in Embodiment 1 of this invention. Sectional view of the base positioned with the mounting jig on the base The expanded sectional view of the screwing part of the spindle motor in Embodiment 1 of this invention (A) is a figure explaining the rotor hub inclination measuring method in Embodiment 1 of this invention, (b) is a figure which shows the inclination distribution of the rotor hub in Embodiment 1 of this invention. The figure explaining the attachment method to the base of the rotor unit in other embodiment of this invention (A) is sectional drawing of the jig | tool which fixes a rotor hub using the permanent magnet in other embodiment of this invention, (b) is a rotor hub using the electromagnet in other embodiment of this invention. Cross-sectional view of fixing jig (A) is a top view which shows the reference plane of two bases in other embodiment of this invention, (b) is a top view which shows the reference plane of one base in other embodiment of this invention Sectional drawing of the state attached with inclination with the jig | tool of the rotor unit and base in other embodiment of this invention

Explanation of symbols

6 Base 6a Base side spiral groove 6b1, 6b2, 6b3 Reference surface convex portion (second reference surface)
7 Shaft 7a Shaft side spiral groove 8 Rotor hub 8c Disc placement surface (first reference surface)
9 Sleeve 21 Adhesive 19 Positioning jig 19a Jig side first reference surface 19d Jig side second reference surface 20 Fastening jig 21 Adhesive

Claims (6)

A base provided with a screw-shaped base side spiral groove;
A shaft having a screw-shaped shaft-side spiral groove on one end side to be screwed into the base-side spiral groove;
A sleeve provided to be rotatable relative to the shaft;
A rotor hub fixed to the sleeve and having a disk mounting surface;
A first reference surface for suppressing inclination of the disk mounting surface provided on the rotor hub;
A second reference surface for suppressing the inclination of the disk mounting surface provided on the base;
A gap formed between the shaft-side spiral groove and the base-side spiral groove;
A spindle motor provided with an adhesive filled in the gap. A base provided with a screw-shaped base side spiral groove;
A sleeve having, on one end side, a screw-shaped sleeve-side spiral groove that is screwed into the base-side spiral groove;
A shaft provided so as to be rotatable relative to the sleeve;
A rotor hub fixed to the shaft and having a disk mounting surface;
A first reference surface for suppressing inclination of the disk mounting surface provided on the rotor hub;
A second reference surface for suppressing the inclination of the disk mounting surface provided on the base;
A gap formed between the sleeve side spiral groove and the base side spiral groove;
A spindle motor provided with an adhesive filled in the gap.   The spindle motor according to claim 1, wherein the adhesive is a conductive adhesive. An information device using the spindle motor according to any one of claims 1 to 3. It is a manufacturing method of the spindle motor according to claim 1,
An adhesive application step of applying an adhesive to the base-side spiral groove;
A base insertion step of screwing the shaft-side spiral groove and the base-side spiral groove;
A rotor hub positioning step that regulates and holds an inclination of at least one of the first reference surface and the second reference surface and the disk mounting surface within a predetermined range;
A spindle motor manufacturing method comprising an adhesive curing step of curing the adhesive. It is a manufacturing method of the spindle motor according to claim 2,
An adhesive application step of applying an adhesive to the base-side spiral groove;
A base insertion step of screwing the sleeve side spiral groove and the base side spiral groove;
A rotor hub positioning step that regulates and holds an inclination of at least one of the first reference surface and the second reference surface and the disk mounting surface within a predetermined range;
A spindle motor manufacturing method comprising an adhesive curing step of curing the adhesive.

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