JP2000040340A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shroud structure capable of reducing the power consumption by reducing the air resistance while taking the assemblability into consideration and further capable of preventing dust from entering into the side of a magnetic disk from the outside of the shroud. SOLUTION: In this magnetic disk device provided with a base 504 for fixedly supporting a spindle motor to rotate magnetic disks 501 and a voice coil motor, the cylindrical shroud 503 arranged on the base so as to cover the circumference of the magnetic disk other than the rocking range of an actuator, and a cover 611 constituting the enclosure by covering the base 504 so as to hermetically seal the magnetic disk or the spindle motor, the air resistance is reduced and also the dust is prevented from entering into the side of the magnetic disk from the outside of the shroud in such a manner that the shroud includes the upper surface projected toward the cover with a gap then the space between the upper surface of this shroud and the base surface at the position faced each other to the upper surface of the shroud is flattened with the accuracy of <=0.2 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device in which the magnetic disk is covered with a shroud to improve the flying stability of a magnetic head, and more particularly to a magnetic disk device capable of preventing the generation of dust in the shroud. It relates to a disk device.

[0002]

2. Description of the Related Art Generally, a magnetic disk drive performs data recording / reproduction while floating a magnetic head on a magnetic disk rotating at high speed by viscous flow of air molecules. To stabilize the flow,
Furthermore, it is important to prevent dust in the air stream from entering.

For this reason, as shown in FIG. 1 and FIG. 2, the prior art comprises a magnetic disk 101 supported by a hub 105 of a spindle motor and rotated at high speed, and a magnetic head 106 for recording and reproducing data on the magnetic disk 101.
And an actuator 102 including a rotation shaft 109 for supporting the magnetic head 106 by a load beam 107 and a guide arm 108 and swingably supporting the magnetic head on a magnetic disk.
And a voice coil motor 110 for rotating the actuator 102 and a base 104 for fixedly supporting the spindle motor, the voice coil motor 110 and the like. A shroud 103 which forms part of a cylinder arranged on the base to cover except for the area,
The magnetic disk 101 to the voice coil motor 110
And a cover 211 (FIG. 2) that forms an enclosure by covering the base 104 so as to hermetically seal the outer periphery of the magnetic disk 101 and the cover 21.
It is configured so as to be hermetically sealed by the number 1. Even if the base 104 is covered with the cover 211, the outside air and the air are actually circulated by the respiratory filter. However, in this specification, covering to prevent dust from entering from the outside air is called sealing.

[0004] The shroud 103 is formed by connecting the right half of the magnetic disk shown in FIG.
Cover the left half of the magnetic disk except for the range in which the magnetic disk swings, and cover the outer peripheral portion of the magnetic disk substantially to prevent the turbulence of the air flow generated on the magnetic disk surface. In this example, a set of four members is called a shroud. As shown in FIG. 2, which is a partial cross-sectional view of FIG.
(2) Standing up by using another (welding), the upper surface of the shroud 103 is sandwiched between the inner surface of the cover 211, thereby covering about 320 ° around the magnetic disk, and the magnetic disk rotates at a high speed of 7200 RPM to 10000 RPM. In this case, the air resistance, which is remarkably generated in such a case, is reduced, and the power consumption of the magnetic disk device is reduced.

In this embodiment, an example in which the shroud is adhered to the base has been described. However, as shown in FIG. 4, the structure of the shroud which is often used at present is integrally formed with the base 404 manufactured by aluminum die casting. The gap between the end of the shroud 403 manufactured and the cover 411 is provided with a sufficient gap (about 2 mm) so that they do not touch each other.

When the magnetic disk device is used as a storage device of a portable computer or a laptop computer, its low power consumption is effective in extending the life of a rechargeable battery built in the portable computer or the laptop computer. And
When used as a storage device of a desktop computer, its low power consumption is effective in saving energy.

Another effect of the shroud is that dust in the enclosure is prevented from diffusing to the magnetic disk side. That is, since the shroud surrounds the magnetic disk, it forms a wall that blocks off the magnetic disk side from the outside, thereby preventing dust from entering the magnetic disk side from the voice coil motor 110 side.

In the magnetic disk drive of this embodiment, as shown in FIG. 2, a cover 211 hermetically covers the upper portion of the base 104, and an elastic body is provided at a contact portion between the upper surface of the base 104 and the base 104. By sandwiching the packing 212, a structure in which the height variation of the shroud and the upper end of the base is absorbed by the elastic body is adopted to prevent the outside air from entering the inside. As a document describing the magnetic disk device having the shroud structure, for example, US Pat. No. 5,631,787 is cited.

[0009]

The above-mentioned magnetic disk drive according to the prior art employs a structure in which an elastic body (packing) is interposed between a base and a cover to absorb variations in the height of the shroud with the elastic body. Therefore, the configuration is such that no gap is formed between the shroud and the cover, but has the following problem.

(1) Difficulty of mounting shroud to base: In the magnetic disk device described in the above-mentioned publication, since the shroud is fixed on the base by an adhesive, the shroud is fixed in addition to the mounting position and inclination at the time of bonding and fixing. , There are many dimensions that need to be adjusted such as sticking out due to excessive amount of adhesive applied,
There was a problem that the mounting work of the shroud was difficult and complicated. In particular, these positions and tilts affect the performance of the shroud itself, requiring delicate work that is quite nervous.

(2) Tilt after the cover is attached: The magnetic disk drive according to the prior art has a base 104 as shown in FIG.
Since the elastic body (packing) 212 is interposed between the elastic body (packing) 212 and the cover 211, the structure is adopted in which the height variation of the shroud 103 is absorbed by the elastic body 212.
When the cover 211 is attached to the base 104 with a screw or the like, a portion where the tip of the shroud 103 and the cover 211 abut acts as a fulcrum. For example, the cover 211 on the side where the screw 315 is fastened first is lowered, and the screw 316 is later mounted. The tightened side is raised and will not fall down, and the cover 211
However, there is a problem that the tilting occurs at the shroud 103.

The inclination of this cover 211 is
Rotating shaft 314 of the spindle motor fixed to
In addition, the rotation axis 313 of the actuator is tilted to cause trouble in each rotation operation or the positioning operation of the magnetic head, which causes a problem that the reliability of the device is reduced. In particular, with the recent increase in the recording density of magnetic disks, high precision is required for positioning the magnetic head.
The inclination of the rotation shaft 314 of these spindle motors becomes the inclination of the magnetic disk, and further the rotation shaft 31 of the actuator.
3, the inclination of the magnetic head becomes the inclination of the magnetic head, so that the positioning accuracy is lowered and the flying height of the magnetic head becomes unstable.

It is also conceivable to assemble the magnetic disk drive so as to prevent the cover from tilting, but this is done by always measuring the cover tilt while the device is placed on a horizontal base. It is necessary to gradually tighten the screws, which causes a problem that the working efficiency is poor.

Further, in the magnetic disk drive using an aluminum die cast in which the shroud shown in FIG. 4 is cast integrally with the base, the gap between the tip of the shroud 403 and the cover 411 may not contact each other due to the limit of casting accuracy. It is necessary to provide a gap of about 2 mm, for example, so that dust outside the shroud 403 easily flows into the magnetic disk through the gap.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, and to provide a magnetic disk drive having a shroud that reduces power consumption by reducing air resistance and suppresses dust from entering the magnetic disk. To provide.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a magnetic disk rotated by a spindle motor, a magnetic head for recording and reproducing data on and from the magnetic disk, and a load beam mounted on the magnetic head. An actuator including a rotating shaft supported by a guide arm and swingably supported on a magnetic disk, a voice coil motor for rotating the actuator, and a base for fixedly supporting the spindle motor and the voice coil motor A cylindrical shroud disposed on the base so as to cover the periphery of the magnetic disk excluding the swing range of the actuator, and a cover forming an enclosure covering the base so as to seal the magnetic disk or the spindle motor Wherein the shroud faces the cover. Comprises a cylindrical upper surface which projects with a gap Te, gap 0.2mm between the position of the base surface facing the upper surface and the upper surface of the shroud of the shroud
A first feature is that the surface is machined with the following accuracy, and a second feature is that an elastic body is disposed in a gap between an upper surface of the shroud and a base surface at a position facing the upper surface of the shroud. A third feature is that a gap between an upper surface of the shroud and a base surface at a position facing the upper surface of the shroud has a labyrinth structure.

[0017]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 5 is a diagram showing a state where a cover of the magnetic disk device to which the present invention is applied is opened, and FIG.
FIG. 3 is a diagram for explaining a base and a cover of the magnetic disk drive according to the first embodiment of the present invention.

The magnetic disk drive shown in FIG. 5 has a magnetic disk 501 fixed to a spindle motor hub 505.
And a magnetic head 5 disposed on the magnetic disk 501.
, A load beam 507 that supports the magnetic head 506 at one end, a guide arm 508 that supports the other end of the load beam 507, and an actuator unit that includes a rotation shaft 509 that swingably supports the guide arm 508. 50
2, a voice coil motor 510 that applies a rotational driving force to the actuator section 502, a fixed axis of the spindle motor hub 505, and a rotation axis 5 of the actuator section 502.
5 and a base 504 that fixedly supports the magnet portion of the voice coil motor 510 and a cover that covers the base 504 to form an enclosure (FIG. 5).
(Not shown). The base 504 and the cover are generally molded and manufactured by aluminum die casting, and the shroud 503 is integrally molded with the base 504.

FIG. 6 is a partial cross-sectional view of FIG. 5 and shows a shroud 503 from a part of the base 504 of the magnetic disk drive.
Is cast by aluminum die casting such that the shroud 5 of the base 611 is formed as shown in FIG.
3 shows an example in which a step is provided in a portion facing the front end of the reference numeral 03. FIG. 7 shows an enlarged view of the portion B in FIG.

As shown in FIG. 7, in the present embodiment, the upper end 720 of the shroud 503 and the cover surface 721 at a position facing the upper end 720 protrude, and the interval is C.
The reason why the cover surface 721 is formed as a protruding step is that it is difficult to keep the surface accuracy of the opposing surface of the shroud at high accuracy by simply manufacturing the cover by casting or other methods. In order to achieve high precision, the shroud-facing surface side of the cast cover is mechanically processed, and the cover surface 721 is processed with high precision, for example, in the range of ± 0.05 mm, based on this processed surface. To do it. The upper end 720 of the shroud 503 is also processed with high accuracy, for example, in a range of ± 0.05 mm based on the support base of the base 504.

Therefore, in the magnetic disk drive according to the present embodiment, the surface accuracy of the cover surface 721 of the cover 611 and the surface accuracy of the upper end 720 of the shroud 503 are set to, for example, ± 0.
Since it is formed by processing in the range of 05 mm, the interval C can be made within 1 mm on average, and the intrusion of dust from the outside of the shroud to the magnetic disk side can be greatly reduced.

The relative structure between the cover surface of the cover and the upper end of the shroud is not limited to the structure shown in FIG. 6, but may be another structure. Hereinafter, a structure according to another embodiment will be described with reference to FIG.

FIG. 8 is a view showing a relative structure between a cover and a shroud of a magnetic disk drive according to another embodiment of the present invention. In the structure according to this embodiment, a position facing the shroud 803 of the cover 811 is engraved. Recess 812
Is formed, and the height of the shroud 803 is set to a height at which the shroud 803 enters the engraved concave portion 812, and the bottom of the concave portion 812 and the upper end of the shroud 803 are machined by ± 0.0.
Processing within the range of 5 mm precision is performed, and the interval D is 1 on average.
mm. In the magnetic disk drive according to the present embodiment, the surface on the cover 811 side is ground, and the above-described concave portion 812 is formed on the basis of this ground surface.
12 can be machined to a depth of ± 0.05 mm by machining, and the upper surface 82 of the shroud 803 can be machined.
0 can be processed within a range of ± 0.05 mm with reference to the support base of the base.
The distance D between 0 and the bottom surface of the concave portion 812 can be made 1 mm or less on average.

FIG. 9 is a view showing a relative structure between a cover and a shroud of a magnetic disk drive according to still another embodiment of the present invention.
And the upper surface 920 of the shroud 903 are formed in parallel with each other. In this embodiment, the surface of the cover 911 is machined by ± 0.05 m.
m, and the upper end 9 of the shroud 903
20 is the accuracy of die casting without machining ± 0.2
mm is applied. In this case, the shroud 90
The gap E between the upper end 920 of the third and the inner surface 921 of the cover 911 can be about 0.25 mm on average. Therefore, if the performance required as the dust blocking wall of the shroud is not very high, this gap is sufficient. is there.

FIG. 10 shows the upper end 10 of the shroud 1003.
7 shows an embodiment in which an elastic body 1022 is sandwiched in a gap between an inner surface 1021 of the cover 1011 and the opposite inner surface 1021, and these gaps F are similar to the gap C of the embodiment shown in FIG.
It can be set to a high precision of about 0.1 mm, and the infiltration of dust can be completely prevented by sandwiching the elastic body 1022 at this interval F.

FIG. 11 shows an example in which a labyrinth structure is formed between the upper end of the shroud 1103 and the inner surface facing the cover 1111.
The gaps G and H formed between the inner surfaces facing each other can be set with a high accuracy of about ± 0.1 mm each in the same manner as in the above-described embodiment, and a labyrinth structure having a space 1123 between the gaps G and H is used. Form. The magnetic disk drive according to the present embodiment has a labyrinth structure in which projecting portions intersect with each other between the cover and the upper end of the shroud, thereby further preventing intrusion of dust as compared with the embodiments except the above-described embodiment of FIG. can do.

FIG. 12 shows the shroud 1 of the cover 1211.
An embodiment is shown in which a portion facing the upper end of 203 is protruded and a U-shaped groove 1224 is formed at the upper end of the shroud 1203. In this embodiment, the upper surface 1220 of the shroud 1203 and the inner surface 1221 facing the cover 1211
Since a space 1224 set at a high accuracy of about ± 0.1 mm can be provided in the gap J formed therebetween, it is possible to obtain a dust prevention effect close to a labyrinth structure as shown in FIG. In this structure, as shown in FIG. 13, for example, a cylindrical space 1324 may be provided by forming a U-shaped groove also on the cover 1311 side. In this case, the effect of preventing dust can be further improved. it can.

FIG. 14 shows the cover 1 shown in FIG.
An elastic body 1425 is arranged on a surface of the 211 protruding from a location facing the upper end of the shroud 1203 and a U-shaped groove 1224 provided on the upper end of the shroud 1203.
According to the present embodiment, intrusion of dust can be completely prevented.

FIG. 15 is a view for explaining a further embodiment of the present invention. In contrast to the above-mentioned embodiment in which dust is prevented between the vicinity of the inner surface of the cover and the tip of the shroud, the present embodiment is different from the embodiment shown in FIG. In the configuration, the outer peripheral wall and the shroud project from both sides of the cover and the base of the magnetic disk drive to about half the width of the magnetic disk drive, in other words, about half the length of the spindle, and extend from the cover and the base side. The outer wall and the shroud face each other at a position approximately half the length of the spindle, and an elastic body is sandwiched between the opposing portions of the outer wall to maintain a sealed structure. More specifically, in this embodiment, the shroud has a shroud 1503 and an outer wall extending from the base 1504 and a shroud 1526 and an outer wall extending from the cover 1511 each extending in the axial direction of the spindle motor so that the shroud is substantially centered or laminated on the enclosure. The magnetic disks 1501 face each other at the center.

The reason why the present embodiment is constructed is that, in general, when the shroud is integrally formed by die casting, the gradient for removing the mold (the draft of the mold) is about 3 ° in the axial direction of the spindle motor. In the case of a 3.5-inch magnetic disk device having a device height of 1 inch (shroud height of about 18 mm), the distance between the lowermost and uppermost magnetic disk end faces (shroud and shroud) Difference of about 0.5 mm)
This is to reduce the cause of the disturbance of the air flow.
That is, if the shroud is extended from both the base and the cover so as to face the center of the enclosure or the center of the stacked magnetic disks as in this embodiment, the influence of the gradient due to die casting can be reduced by half, and the lowermost part and the lowermost part of the shroud can be reduced. The difference in the distance from the upper magnetic disk end face is set to 0.
The shroud can be reduced to about 25 mm, and it is possible to prevent the shroud from being too far from the end face of the magnetic disk and causing the turbulence of the air flow. Further, the upper end 1520 of the shroud 1503 on the base side and the lower end 15 of the shroud 1526 on the cover side
21 can be machined with a high accuracy of ± 0.05 mm, so that the shroud 15 on the base side can be machined.
The gap K formed by the upper end 1520 of the cover 03 and the lower end 1521 of the shroud 1526 on the cover side can be about 0.1 mm on average. Further, the magnetic disk drive according to the present embodiment uses a shroud shaped by die-casting, so that the assembling operation is easy because the bonding operation is not involved as in the above-described known example. In order to join the cover and the base, which are divided in about half, no inclination occurs when the cover and the base are assembled to each other as in the known example.

As described above, according to each embodiment of the present invention, the upper surface of the shroud and the base surface facing the upper surface of the shroud are flat-processed with an accuracy of ± 0.5 mm, or the upper surface of the shroud is processed. Disposing an elastic body in a gap between the surface and the base surface at a position facing the upper surface of the shroud, or providing a labyrinth structure in a gap between the upper surface of the shroud and the base surface at a position facing the upper surface of the shroud. Thus, it is possible to provide a magnetic disk device having a shroud that reduces power consumption by reducing air resistance and suppresses dust from entering the magnetic disk side. Furthermore, in each embodiment, the cover in the range facing the upper end of the shroud is machined with high precision by machining, the gap between the shroud tip and the cover is made as small as possible, and an elastic body is sandwiched between the shroud and the cover. In addition, by forming a labyrinth with the upper end of the shroud and the cover, 1) since the shroud and the cover do not directly abut, the cover is inclined when the cover is attached to the base, and the rotating shaft of the spindle motor or the actuator is inclined. 2) Since the gap between the shroud and the cover can be reduced to about 0.1 mm, it is possible to prevent dust from flowing from the outside of the shroud to the magnetic disk side. 3) The labyrinth is provided at a portion where the shroud and the cover face each other. Dust flows from the outside of the shroud to the magnetic disk side. It can be further suppressed from,
4) By sandwiching the elastic body in the portion where the shroud and the cover face each other, it is possible to completely prevent dust from flowing from the outside of the shroud to the magnetic disk side. 5) By extending the shroud from the base side and the cover side to the same extent,
The distance between the shroud and the end face of the magnetic disk due to the gradient (draft angle of the mold) which always occurs when the die is formed by die casting can be reduced to approximately half that of the case where only the base side is extended.

The magnetic disk drive according to the present invention can also be expressed as the following embodiment.

<Embodiment 1> A spindle motor hub rotatably supported, at least one magnetic disk fixed to the spindle motor, and arbitrary information arranged opposite to the magnetic disk are written / read. At least one magnetic head, a load beam for supporting and fixing the magnetic head to one end thereof, a guide arm for supporting and fixing the other end of the load beam, and a rotating shaft for swingably supporting the guide arm An enclosure is configured by mounting an actuator portion, a voice coil motor that generates a rotational force on the rotating shaft, a base that supports and fixes the spindle motor, the rotating shaft of the actuator, and the voice coil motor, and a base facing the base. The actuator is made up of a cover that covers A cylindrical wall (shroud) excluding the range of swinging and the range of parts (for example, magnets of voice coil motors) arranged in the enclosure
, The lower end of the shroud is fixed on the base, the upper end has a gap between the cover, and the area of the cover facing the upper end of the shroud and at least the upper end of the shroud. A magnetic disk drive characterized by being machined with high precision by machining.

<Second Embodiment> A magnetic disk drive according to claim 1, wherein an elastic body is interposed between an upper end of the shroud and a cover.

<Embodiment 3> A magnetic disk drive according to claim 1, wherein a labyrinth structure is formed by a combination of an upper end of the shroud and a range of the cover facing the shroud.

<Fourth Embodiment> A magnetic disk drive according to the first embodiment, wherein a U-shaped groove is formed in at least one of the upper end of the shroud and the area of the cover facing the shroud.

<Fifth Embodiment> A magnetic disk drive according to the fourth embodiment, wherein an elastic body is disposed in the U-shaped groove.

<Embodiment 6> A magnetic disk drive according to any one of Embodiments 1 to 5, wherein the base is manufactured by aluminum die-casting, and the shroud is also integrally formed with the base.

<Embodiment 7> A spindle motor hub rotatably supported, at least one magnetic disk fixed to the spindle motor, and arbitrary information arranged opposite to the magnetic disk are written / read. At least one magnetic head, a load beam for supporting and fixing the magnetic head to one end thereof, a guide arm for supporting and fixing the other end of the load beam, and a rotating shaft for swingably supporting the guide arm An enclosure is configured by mounting an actuator portion, a voice coil motor that generates a rotational force on the rotating shaft, a base that supports and fixes the spindle motor, the rotating shaft of the actuator, and the voice coil motor, and a base facing the base. The actuator is made up of a cover that covers A cylindrical wall (shroud) excluding the range of swinging and the range of parts (for example, magnets of voice coil motors) arranged in the enclosure
And the shroud extends approximately the same height in the axial direction of the spindle motor from the base and the cover so as to face each other, and the upper end of the shroud of the base and the shroud of the cover. A magnetic disk drive characterized in that the lower end is machined with high precision.

Eighth Embodiment A magnetic disk drive according to the seventh embodiment, wherein an elastic body is interposed between the upper end of the shroud and the cover.

<Embodiment 9> A magnetic disk drive according to embodiment 7, wherein a labyrinth structure is formed by a combination of an upper end of the shroud and a range of the cover facing the shroud.

<Embodiment 10> In Embodiment 7,
A magnetic disk drive, wherein a U-shaped groove is formed in at least one of the upper end of the shroud and the area of the cover facing the shroud.

<Eleventh Embodiment> A magnetic disk drive according to the tenth embodiment, wherein an elastic body is disposed in the U-shaped groove.

<Embodiment 12> A magnetic disk drive according to any one of Embodiments 7 to 11, wherein the base is manufactured by die-casting aluminum, and the shroud is also integrally formed with the base.

<Embodiment 13> A spindle motor hub rotatably supported, at least one magnetic disk fixed to the spindle motor, and arbitrary information arranged opposite to the magnetic disk are written / read. At least one magnetic head, a load beam for supporting and fixing the magnetic head to one end thereof, a guide arm for supporting and fixing the other end of the load beam, and a rotating shaft for swingably supporting the guide arm An actuator section,
A voice coil motor for generating a rotating force on the rotating shaft, a base for supporting and fixing the rotating shaft of the spindle motor and the actuator, the voice coil motor, and a cover constituting an enclosure by being mounted facing the base. Further, a cylindrical wall (shroud) covers an area around the magnetic disk in the radial direction, excluding the range of swinging of the actuator and the area of components (for example, magnets of a voice coil motor) arranged in the enclosure. A magnetic disk drive characterized in that a lower end of the shroud is fixed on a base, an upper end of the shroud has a gap between itself and the cover, and an elastic body is inserted in the gap of the shroud. .

[0046]

As described above, the present invention is arranged on the base so as to cover the periphery of the magnetic disk except for the swing range of the actuator and the base for fixedly supporting the spindle motor and the voice coil motor. In a magnetic disk drive comprising: a cylindrical shroud; and a cover forming a enclosure covering a base so as to seal the magnetic disk or the spindle motor, wherein a cylindrical upper part in which the shroud projects with a gap toward the cover. Surface, and the upper surface of the shroud and the base surface at a position facing the upper surface of the shroud are flat-processed with an accuracy of ± 0.5 mm to reduce air resistance and reduce power consumption, and Dust can be suppressed from entering the magnetic disk side.

[Brief description of the drawings]

FIG. 1 is a diagram showing the structure of a magnetic disk drive according to the related art.

FIG. 2 is a cross-sectional view showing a shroud structure according to the related art.

FIG. 3 is a diagram for explaining a tilt of a cover caused by a conventional technique.

FIG. 4 is a diagram for explaining a shroud structure that is currently frequently used.

FIG. 5 is a view showing the structure of a magnetic disk drive to which the present invention is applied.

FIG. 6 is a diagram for explaining a shroud structure according to the first embodiment of the present invention.

FIG. 7 is a partially enlarged view of FIG. 6;

FIG. 8 is a diagram illustrating a shroud structure according to a second embodiment of the present invention.

FIG. 9 is a view for explaining a shroud structure according to a third embodiment of the present invention.

FIG. 10 is a view for explaining a shroud structure sandwiching an elastic body according to a fourth embodiment of the present invention.

FIG. 11 is a view for explaining a shroud structure having a labyrinth structure according to a fifth embodiment of the present invention.

FIG. 12 is a view for explaining a shroud structure having a U-shaped groove according to a sixth embodiment of the present invention.

FIG. 13 is a view for explaining a shroud structure having a U-shaped groove according to a seventh embodiment of the present invention.

FIG. 14 is a view for explaining a shroud structure in which an elastic body is arranged in a U-shaped groove according to an eighth embodiment of the present invention.

FIG. 15 is a view for explaining a shroud structure in which a shroud is extended from both a base and a cover according to a ninth embodiment of the present invention.

[Explanation of symbols]

100: magnetic disk drive, 101: magnetic disk, 1
02 ... actuator, 103 ... shroud, 104 ...
Base, 105: spindle motor hub, 202: adhesive, 205: spindle motor hub, 211: cover,
212: elastic body (packing), 301: magnetic disk, 305: spindle motor hub, 313: spindle motor fixed shaft, 314: actuator rotation shaft, 31
5: Screw, 316: Screw, 317: Actuator, 3
18 ... screws, 319 ... screws, 401 ... magnetic disk, 4
03 Shroud, 404 base, 405 spindle motor hub, 411 cover, 500 magnetic disk drive, 501 magnetic disk, 502 actuator, 503 shroud, 504 base, 505 spindle motor hub, 506 magnetic Head, 507: load beam, 508: guide arm, 509: rotation axis,
510: Voice coil motor, 611: Cover, 720
... Upper end of the shroud, 721: Surface of the cover facing the shroud, 811: Cover, 803: Shroud, 8
20: upper end of shroud, 821: surface of cover facing shroud, 903: shroud, 911: cover, 920: upper end of shroud, 921: surface of shroud facing cover, 1003: shroud, 101
1 ... cover, 1020 ... upper end of shroud, 1021 ...
Surface facing the shroud of the cover, 1022 elastic body (rubber), 1103 shroud 1111 cover, 1
123 space, 1203 shroud, 1211 cover, 1220 upper end of shroud, 1221 surface of cover facing shroud, 1224 U-shaped groove, 1
311: cover, 1321: surface of cover facing shroud, 1324: U-shaped groove, 1425: elastic body (rubber), 1501: magnetic disk, 1503: shroud (base side), 1504: base, 1505: spindle motor Hub, 1511 ... cover, 1520 ... upper end of shroud (base side), 1521 ... lower end of shroud (cover side), 1526 ... shroud (cover side).

Claims (3)

[Claims] A magnetic disk rotatably driven by a spindle motor; a magnetic head for recording and reproducing data on and from the magnetic disk; and a magnetic head supported by a load beam and a guide arm to swing on the magnetic disk. An actuator including a rotating shaft that supports the actuator, a voice coil motor that rotates the actuator, a base that fixedly supports the spindle motor and the voice coil motor, and a periphery of the magnetic disk excluding a swing range of the actuator. A magnetic disk drive comprising: a cylindrical shroud arranged on a base so as to cover the base; and a cover forming an enclosure covering the base so as to seal the magnetic disk or the spindle motor, wherein the shroud faces the cover. Including a cylindrical upper surface protruding with a gap, Magnetic disk drive, characterized in that the flattening at the gap 0.2mm or less and comprising such accuracy between the upper surface and the upper surface and facing the position of the base surface of the shroud of the shroud. 2. The magnetic disk drive according to claim 1, wherein an elastic body is disposed in a gap between an upper surface of the shroud and a base surface at a position facing the upper surface of the shroud. 3. The magnetic disk drive according to claim 1, wherein a gap between an upper surface of the shroud and a base surface at a position facing the upper surface of the shroud has a labyrinth structure.