JP2566388Y2 - Magnetic disk drive - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive capable of increasing the strength of fixing a yoke to a hub, stabilizing a disk mounting surface of the hub, and eliminating errors in reading servo information of a magnetic disk. It is.

[0002]

2. Description of the Related Art Some magnetic disk drive devices include a yoke for mounting a drive magnet of a magnetic disk drive motor, and this yoke is fixed to a flange portion of a hub. At this time, the yoke can be fixed by bonding with an adhesive or the like. However, fixing with an adhesive has the drawback that not only is it time-consuming until the adhesive is hardened, the working efficiency is poor, but also the yoke fixing strength is weak and reliability is lacking. In order to solve such a problem, a flange portion is provided on a hub which is driven by mounting a magnetic disk,
The flange portion of the yoke is engaged with the flange portion, and the engagement protrusions formed at several places on the flange portion of the hub are
In some cases, the yoke is fixed by partially caulking with a punch or the like. 6 to 8 show specific examples of such a conventional magnetic disk drive.

In FIG. 6 to FIG. 8, a hub 1 is driven by mounting a magnetic disk (not shown) on an outer peripheral surface thereof, and moves upward from an inner peripheral surface of the hub 1 and a center of a frame 6. Bearings 15 and 16 composed of two ball bearings are vertically mounted between the extended cylindrical fixed center shaft 13. Inner ring 1 of each bearing 15, 16
7, 18 are on the center fixed shaft 13, and the outer rings 19, 20 are on the hub 1.
Are fixed to each other by being press-fitted into the center hole 23. .

[0004] The hub 1 is provided with several holes 27 for disk clamping around the circumference of the hub 1. Hub 1
An outwardly facing flange portion 2 is formed concentrically with the center fixed shaft 13 at the lower portion of the shaft. At a lower portion of the flange portion 2, engagement protrusions 3 are formed at several places along the circumference of the flange portion 2. The inward flange portion of the rotor yoke 4 is fitted into the engagement protrusion 3 and is bonded with an adhesive, and the engagement protrusion 3 is partially caulked with a punch or the like, whereby a ring-shaped rotor yoke 4 is formed. Are fixed to the hub 1. A ring-shaped drive magnet 5 is fixed to the inner surface of the yoke 4. The inner peripheral surface of the ring-shaped drive magnet 5 faces the outer peripheral surface of the stator core 7 with an appropriate gap from the drive magnet 5. Stator core 7 is fitted and fixed to the outer peripheral side of the base of central fixed shaft 13 formed wider than the tip. The stator core 7 has an appropriate number of salient poles radially, and a driving coil 8 is wound around each salient pole. Lead wire 9 from this drive coil 8
Is pulled out from the hole 10 on the bottom surface of the frame 6 and is connected to the connector 28 via a flexible board 29 attached to the bottom surface of the frame 6.

[0005]

According to the conventional magnetic disk drive described above, the engaging projection formed on the flange of the hub is partially caulked with a punch or the like to fix the yoke to the hub. Therefore, a stress difference was generated between the swaged portion and the unswaged portion. Therefore, this stress difference causes undulation on the drive surface of the hub, and swells on the disk mounted on the hub,
When the hub is driven, there is a problem that servo information on the disk surface cannot be accurately read due to the undulation. In particular, as the thickness of the hub is reduced, the influence of the stress difference is greatly affected, and the undulation of the hub is increased, which greatly affects the reading of servo information. This is a serious problem in a magnetic disk drive in which a reduction in size is required and the thickness of the hub must be reduced. On the other hand, when the yoke is bonded to the hub with an adhesive, there is a problem that it takes time until the adhesive is hardened, the work efficiency is poor, and the fixing strength is not sufficient.

[0007] The present invention has been made to solve the problems of the conventional magnetic disk drive, as well as enhance the fixing strength for fixing the yoke to the hub, de hub
It is an object of the present invention to provide a magnetic disk drive capable of accurately reading servo information of a magnetic disk by stabilizing a disk mounting surface .

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a fixed shaft erected on a frame;
C rotatably supported via bearings fitted on the shaft
And a magnet attached to the inner peripheral surface and secured to the hub.
A magnetic disk drive comprising:
The hub mounts a magnetic disk on one surface in the axial direction
At the same time, an engagement projection for fixing the yoke is formed on the other surface.
And the yoke is provided with a flange of the hub.
With the flange in contact with the other side of the flange,
The engaging projection of the part is caulked over the entire circumference and
It is characterized by being fixed.

[0009]

The magnetic disk is mounted on the outer peripheral surface of the hub and is driven. A drive magnet is fixed to the yoke attached to the bottom of the hub. The yoke is fixed to the hub by caulking the entire periphery of the engaging projection formed on the flange of the hub. By caulking the entire circumference of the engaging projection, there is no stress difference in the circumferential direction of the hub.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic disk drive according to the present invention will be described below. Components common to the components of the conventional example shown in FIGS. 6 to 8 are denoted by the same reference numerals. 1 to 5, a hub 1 is driven by mounting a magnetic disk (not shown) on an outer peripheral surface thereof. The hub 1 has a cylindrical center fixed shaft extending from an inner peripheral surface of the hub 1 and a frame 6. The base 13 has a positioning hole 14 formed therein. Bearings 15 and 16 composed of two ball bearings are vertically mounted between the hub 1 and the center fixed shaft 13 . Each bearing 1
The inner rings 17 and 18 of 5 and 16 are attached to the center fixed shaft 13 and the outer ring 1
9 and 20 are attached to the hub 1 respectively. There is a slight gap between the inner ring 18 of the lower bearing 16 and the center shaft 13, and the inner ring 18 is slidable with respect to the center fixed shaft 13. The outer rings 19 and 20 of the bearings 15 and 16 are press-fitted into the center hole 23 of the hub 1. Further, the hub 1 has a jetty 24 at its tip, and the jetty 24 has a hub 1
A magnetic seal 26 having a magnet 25 and the like is arranged so as to close the center hole 23 of the first embodiment.

The inner ring 17 of the bearing 15 presses it upward in the axial direction, and the inner ring 17
Each of the bearings 15, 8 is preloaded in the direction indicated by the arrow in FIG.
Sixteen inner rings 17, 18 and outer rings 19, 20 are bonded to the outer peripheral surface of the center fixed shaft 13 and the inner peripheral surface of the hub 1, respectively.
Seals 21 and 22 are attached to both ends of each of the bearings 15 and 16 to prevent splashes of lubricating oil and the like from scattering outside.

Holes 27 for fixing the disk clamp are formed in the distal end portion of the hub 1 at several positions in the axial direction. An outwardly facing flange portion 2 is integrally formed at a lower portion of the hub 1, and an engagement protrusion 3 is formed at a lower portion of the flange portion 2 on a concentric circle with a center fixed shaft 13. As shown in FIG. 4, the cross section of the engaging projection 3 has a trapezoidal shape such that a portion (upper portion in the figure) in contact with the flange portion 2 is widened. The engagement protrusion 3 is provided over the entire circumference of the flange portion, and has a circular shape when viewed from the bottom surface of the hub 1. The inward flange 11 of the ring-shaped yoke 4 is engaged with the engagement protrusion 3. The flange 11 is formed on the upper part of the yoke 4 and is in contact with the bottom surface of the flange 2 of the hub 1. Then, the yoke 4 is fixed to the flange portion 2 of the hub 1 by caulking the engaging projection 3 by high-speed rotational caulking over the entire circumference.

On the inner peripheral surface of the rotor yoke 4, a ring-shaped drive magnet 5 is fixed. An outer diameter of the base of the center fixed shaft 13 of the frame 6 is large, and a stator core 7 is provided on the outer peripheral side of the base of the center fixed shaft.
Is fitted and fixed. The stator core 7 has an appropriate number of salient poles radially, and a driving coil 8 is wound around each salient pole. The outer peripheral surface of the stator core 7, that is, the distal end surface of the salient pole faces the inner peripheral surface of the drive magnet 5 with an appropriate gap. A lead wire 9 from the drive coil 8 is drawn out from a hole 10 formed in the bottom surface of the frame 6 to the bottom surface of the frame 1, and is connected to a connector 28 via a flexible board 29.

According to the embodiment described above, since the engaging projection 3 is caulked over the entire circumference in order to fix the yoke 4 to the hub 1, a circumferential stress difference caused when the caulking is partially caulked is eliminated. Can mount the magnetic disk on the hub 1
The surface can be stabilized, and servo information can be read accurately. In addition, since the engaging projection 3 is swaged over the entire circumference, the fixing strength for fixing the yoke 4 to the hub 1 is increased, so that it is not necessary to use an adhesive or the like to fix the yoke 4, thereby improving the work efficiency. Furthermore, since the engaging projection 3 is swaged using high-speed rotation swaging, the influence on the yoke 3 and the like is suppressed by merely adjusting the rotation speed and the like.
A good appearance can be maintained, and a predetermined specification size can be easily secured. However, as a method of caulking the engaging projection 3, a punch or the like may be used, and is not limited to the description of the embodiment.

According to the illustrated embodiment, the engagement projection 3
By forming the cross-sectional shape of the trapezoidal shape such that it becomes narrower as it goes downward, when the engagement protrusion 3 is crimped, it can be made to fall in the direction of the yoke 4. Needless to say, the shape of the engaging protrusion 3 may be a rectangular shape or the like without being a trapezoidal cross-sectional shape as in the embodiment, and the shape is not limited to the shape of the illustrated embodiment.

In the above embodiment, the material of each part may be arbitrarily selected.
May be formed integrally with the frame 6 or the hub 1,
Since it is easy to process, it may be formed using aluminum.

According to the invention of the present application , the erected frame is
The rotating shaft is fixed via a fixed shaft and a bearing fitted to the fixed shaft.
Attach a magnet to the hub supported inside and the inner peripheral surface
A magnetic disk drive having a yoke fixed to the hub;
The hub is a magnetic device on one surface in the axial direction.
Place the disk and fix the yoke on the other side.
A flange portion having an engaging projection formed therein,
Is in contact with the other side of the flange of the hub
Then, the engaging projection of the above flange is swaged over the entire circumference.
Is due to a to be fixed to the hub, it is possible to eliminate the stress difference generated when was partially crimping hub
The disk mounting surface can be stabilized, and servo information can be read accurately. In addition, by caulking the engaging projections over the entire circumference, the fixing strength for fixing the yoke to the hub is increased, so that it is not necessary to adhere with an adhesive or the like at the time of fixing, and the working efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a bottom view showing an example of a hub and a yoke used in a magnetic disk drive according to the present invention.

FIG. 2 is a longitudinal sectional view of the same.

FIG. 3 is an enlarged sectional view showing an engagement portion between the hub and the yoke before the engagement protrusion of the hub is swaged.

FIG. 4 is an enlarged cross-sectional view showing a state in which the engaging protrusion in the embodiment is swaged.

FIG. 5 is a longitudinal sectional view showing an embodiment of the magnetic disk drive according to the present invention using the hub and the yoke.

FIG. 6 is a bottom view showing an example of a hub and a yoke used in a conventional magnetic disk drive.

FIG. 7 is a longitudinal sectional view of the above.

FIG. 8 is a longitudinal sectional view showing an example of a conventional magnetic disk drive using the hub and the yoke.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hub 2 Flange part of hub 3 Engagement protrusion part 4 Yoke 5 Drive magnet 11 Flange part of yoke

Claims (1)

(57) [Scope of request for utility model registration] A fixed shaft erected on a frame;
C rotatably supported via bearings fitted on the shaft
And a magnet attached to the inner peripheral surface and secured to the hub.
A magnetic disk drive, comprising: a yoke; and the hub mounts the magnetic disk on one surface in the axial direction.
At the same time, an engagement projection for fixing the yoke is formed on the other surface.
And the yoke contacts the other surface of the flange portion of the hub.
In the contact state, the engaging projection of the flange portion extends all around.
It is characterized by being swaged and fixed to the hub
Magnetic disk drive according to.