JP2006139859A - Disk driver and magnetic disk device using the driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk driver and a magnetic disk using the driver in which thickness is reduced while maintaining rigidity that provides stable rotation. <P>SOLUTION: A disk driver B is provided with a cylindrical bearing sleeve 2, a shaft 3 which is supported in the bearing sleeve 2 in a freely rotative manner, a hub 4 being held at the tip of the shaft 3 and having a receiving section 4j, that mounts a disk medium 5 at the outside of the bearing sleeve 2, protrusively formed and a clamp 6 which holds the disk medium 5 between the receiving section 4j of the hub 4. The clamp 6 is formed into a ring shape so as to be externally inserted onto a top section 4h of the hub 4. A male screw section 4d is formed on the outer peripheral of the top section 4h of the hub 4. A nut 9, which provides clamping force to the clamp 6 and holds the disk medium 5, is screwed onto the male screw section 4d. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disk drive apparatus that rotates a disk at a constant high speed while holding a disk medium, and a magnetic disk apparatus using the same.

  In recent years, for example, while downsizing and thinning of computers and the like have been attempted, downsizing and thinning of hard disk devices (magnetic disk devices) mounted thereon have been demanded. In order to meet this demand, particularly in a thin hard disk drive such as a computer, as one of the methods for miniaturization and thinning, a disk drive device that holds a disk medium and rotates it at a constant high speed includes a hub and a clamp. The method of holding between is adopted.

  FIG. 2 is a sectional view showing a conventional example of this type of disk drive device. The disk drive device A is a so-called shaft rotation type spindle motor, and is fastened to a base 1 having a rectangular plate shape, a cylindrical bearing sleeve 2 fixed to the base 1, and the base 1. At the same time, a shaft 3 rotatably supported inside the bearing sleeve 2, a dish-shaped hub 4 having a substantially cross-sectional side section that is fastened to the shaft 3, and a disc medium 5 are sandwiched together with the hub 4. The clamp 6 to perform and the clamp screw 7 for fixing the clamp 6 are main components (for example, refer patent document 1).

  The bearing sleeve 2 is fitted and fixed to the base 1, and a dynamic pressure bearing portion 8 for rotating the shaft 3 is formed on the inner peripheral side thereof. The shaft 3 is formed in a substantially cylindrical shape, has a small diameter portion 3a having a small outer diameter on the upper end side, and screw holes 3b and 3f in which a female screw is provided on the inner surface from the upper end and the lower end. It is formed inward of the axis. The hub 4 has a cylindrical portion 4a formed at the center. The cylindrical portion 4a is fitted and fixed to the outer peripheral surface 3c of the small-diameter portion 3a of the shaft 3, and the disc medium 5 is formed on the tip side forming the outer peripheral edge. A protrusion 4b is formed so as to protrude toward the surface. The clamp 6 is a dish-like elastic member having a substantially Ω-shaped side cross section, and a circular hole 6a is formed at the center thereof. The clamp screw 7 is formed by integrally forming a screw portion 7a and a screw portion head portion 7b. The clamp screw 7 is fastened to the upper end side of the shaft 3 with the clamp 6 interposed between the clamp screw 7 and the clamp 6 at a predetermined position. In addition, an elastic force (clamping force) is applied to the clamp 6, and the disk medium 5 interposed between the protrusion 4 b of the hub 4 and the clamp 6 is clamped.

In this disk drive A, a lubricating fluid made of lubricating oil or the like is injected into a minute gap portion between the bearing sleeve 2 and the shaft 3, and for example, dynamic pressure generation (not shown) recessed in the dynamic pressure surface of the shaft 3 is generated. Lubricating fluid is pressurized by a groove for use, and dynamic pressure is generated.
JP 2003-164128 A

  However, in the above disk drive device, there is a problem that it is difficult to further reduce the height and reduce the thickness because the clamp is clamped and fixed by fastening the clamp screw.

  In other words, if the shaft is shortened and the height is reduced, the hydrodynamic bearing that greatly affects the rigidity of the disk drive device is also shortened, and the shaft or disk medium can be rotated stably. There was a problem that I could not. In addition, when the length of the hydrodynamic bearing is secured and the shaft is shortened (when the length of the small diameter part is shortened), the fastening of the hub becomes difficult and the fastening length of the clamp screw is shortened. There was a problem that the clamping screw could not be securely fixed due to insufficient fastening force of the clamping screw.

  Furthermore, when clamping the clamp by clamping the clamp screw, it is difficult to position the clamp at a predetermined position, it is difficult to securely clamp the disk medium with a predetermined clamping force, and stable rotation is achieved. There was a problem that it could not be obtained.

  In view of the above circumstances, an object of the present invention is to provide a disk drive device and a magnetic disk device using the disk drive device that can be thinned while ensuring a rigid force capable of obtaining stable rotation.

  In order to achieve the above object, the present invention provides the following means.

  According to a first aspect of the present invention, there is provided a cylindrical bearing sleeve, a shaft rotatably supported in the bearing sleeve, a disc medium mounted on the outer side of the bearing sleeve while being held at the tip of the shaft. In a disk drive device comprising: a hub having a receiving portion that projects and a clamp that clamps the disk medium between the receiving portion of the hub; and the clamp is extrapolated to the head of the hub. In addition, a male screw part is formed on the outer periphery of the head of the hub, and a nut that clamps the disc medium by applying a clamping force to the clamp is screwed onto the male screw part. It is characterized by.

  In the disk drive device according to the present invention, the clamp can be fixed by providing a male screw portion on the outer periphery of the head of the hub and fastening a nut to the male screw portion.

  According to a second aspect of the present invention, in the disk drive device according to the first aspect, the hub includes a step portion having a larger diameter than the male screw portion below the male screw portion. .

  In the disk drive device according to the present invention, since the step portion is provided on the hub, the tightening position of the nut can be limited, and the nut can be prevented from being overtightened.

  According to a third aspect of the present invention, the disk drive device according to the first or second aspect is provided.

  In the magnetic disk device according to the present invention, a disk drive device capable of fixing the clamp by a simple operation of fastening a nut to a hub having a male screw portion can be provided.

  According to the invention which concerns on Claim 1, a clamp can be fixed by providing a male screw part in the head outer periphery of a hub, and fastening a nut to this male screw part. This eliminates the small diameter part of the clamp screw and shaft, and allows the clamp and nut to be positioned almost at or below the height of the hub, thereby reducing the thickness of the disk drive device while ensuring the length of the hydrodynamic bearing. Can be achieved. In addition, since the ring-shaped clamp can be inserted into the hub and the clamp can be pressed and fixed as the nut is tightened, the clamp can be fixed with a simple operation compared to the fixing means that clamps and fixes the clamp with the clamp screw. As a result, the assembly of the disk drive device can be facilitated. Furthermore, the clamp can be positioned relatively easily, and the assembly accuracy can be improved. As a result, a clamping force can be reliably applied to the disk medium, so that a disk drive device capable of obtaining stable rotation can be provided. In addition, since the clamp screw and the small-diameter portion of the shaft can be eliminated, it is possible to particularly reduce the labor required for processing the shaft, and it is possible to improve productivity and economy.

  According to the invention which concerns on Claim 2, since the level | step-difference part is provided in the hub, the fastening position of a nut can be restrict | limited and overtightening of a nut can be prevented. Accordingly, the clamp can be reliably fixed at a position where a predetermined clamping force can be obtained by a simple operation of fastening the nut, and the disk medium can be securely held.

  According to the invention according to claim 3, the magnetic disk can be provided by providing the disk drive device according to claim 1 or 2, wherein the clamp can be fixed by a simple operation of fastening a nut to a hub having a male screw part. The thickness of the apparatus can be reduced, and productivity and economic efficiency can be improved.

  A disk drive device according to an embodiment of the present invention will be described below with reference to FIG. Here, the same components as those of the conventional disk drive device A shown in FIG.

  A disk drive apparatus according to an embodiment of the present invention is mounted on a magnetic disk apparatus, and is used for rotating a disk medium at a constant high speed and storing digital data in a magnetic format in a track of the disk medium.

  As shown in FIG. 1, the disk drive device B of this embodiment includes a rectangular plate-shaped base 1, a cylindrical bearing sleeve 2, a shaft 3 that is rotatably supported by the bearing sleeve 2, and a shaft 3. The hub 4 to be fastened, the nut 9 provided on the outer periphery of the head 4h of the hub 4 and a nut 9 fastened to a male screw portion 4d described later, and a circular hole 6a inserted into the outer periphery of the hub 4 at the center. The clamp 6 that clamps the disk medium 5 together with the hub 4 is a main component.

  The shaft 3 is formed in a substantially columnar shape, and is provided so that the end surface 3 d on the upper end side is horizontally aligned with the end surface 2 a on the upper end side of the bearing sleeve 2. Moreover, the screw hole 3f by which the internal thread was given to the inner surface is formed in the lower end side.

  The hub 4 is made of, for example, a metal such as stainless steel or aluminum, is in surface contact with the end surface 3d on the upper end side of the shaft 3, and is a disk-shaped ceiling plate portion 4e formed larger than the outer diameter of the bearing sleeve 2. A side wall 4g that hangs in the axial direction from the outer peripheral edge side of the lower surface 4f of the ceiling plate 4e toward the base 1 and a diameter that extends from the lower end of the side wall 4g in a direction orthogonal to the axis of the shaft 3 are extended. And a protruding portion 4m. The ceiling plate portion 4e has a male screw portion 4d formed on the outer periphery of the head portion 4h. On the other hand, a protruding portion 4b that protrudes upward is formed at the outer peripheral end of the overhanging portion 4m, and a horizontal receiving portion 4j that makes surface contact with the disk medium 5 described later is formed at the tip of the protruding portion 4b. Has been. Further, in the middle of the side wall portion 4g that hangs down in the axial direction from the ceiling plate portion 4e, that is, at a position below the male screw portion 4d, it is bent at a right angle in the direction of increasing the diameter, and from its tip along the axis A stepped step portion 4k that hangs down is formed.

  The disk medium 5 is a rigid body formed in an annular shape and has a size of 1 inch or less, and an inner hole 5a formed in the center is inserted into a side wall portion 4g that hangs down in the axial direction of the hub 4. The surface of the projecting portion 4b of the hub 4 is brought into surface contact with the receiving portion 4j.

  The nut 9 is formed of a metal such as stainless steel or aluminum, for example, and is screwed into a male screw portion 4d formed on the outer periphery of the head 4h of the ceiling plate portion 4e of the hub 4 and is fastened. The upper surface 9a of the nut 9 is provided so that the height of the upper surface 9a of the nut 9 is substantially equal or lower than the upper surface 4l of the ceiling plate portion 4e of the hub 4.

  The clamp 6 is a dish-like elastic member made of a metal such as stainless steel or aluminum and having a substantially cross-sectional shape in a side section, and has a ring shape with a circular hole 6a formed in the center thereof. . A part of the side wall 4g above the ceiling plate part 4e and the step part 4k of the hub 4 is inserted into the circular hole 6a from the inner surface side, and the outer peripheral surface 6b in the vicinity of the circular hole 6a is pressed against the lower surface 9b of the nut 9 While being fixed. Further, the outer peripheral edge side is suspended toward the receiving part 4j of the protruding part 4b of the hub 4, and a part of the outer peripheral edge side is bent upward, and this bending point is a bent part 6c. The curved portion 6c presses the upper surface 5b of the disk medium 5 placed on the receiving portion 4j.

  In the above configuration, the height dimension H of the disk drive B from the lower surface 1c of the base 1 to the upper surface 4l of the nut 9 and the ceiling plate portion 4e of the hub 4 is 2.7 mm or less.

  Next, a method for holding the disk medium 5 of the disk drive B configured as described above will be described. First, the bearing sleeve 2 is fitted into the base 1, the shaft 3 is inserted into the bearing sleeve 2, and the hub 4 is installed. Further, the inner hole 5 a of the disk medium 5 is inserted into the outer periphery of the side wall part 4 g of the hub 4, and the disk medium 5 is placed in surface contact with the horizontal receiving part 4 j formed on the protruding part 4 b of the hub 4. Next, the clamp 6 is arranged so that the outer periphery of the side wall 4g above the ceiling plate portion 4e and the stepped portion 4k of the hub 4 is inserted into the circular hole 6a. Finally, the head 4h of the ceiling plate portion 4e of the hub 4 is inserted. A nut 9 is fastened to the male screw portion 4d formed on the outer periphery. At this time, the nut 9 is fastened so that the upper surface 9a of the nut 9 is substantially equal to or below the height of the upper surface 4l of the ceiling plate portion 4e of the hub 4. As the nut 9 is fastened, the clamp 6 of the elastic member is pressed by the nut 9 and a clamping force is generated, so that the upper surface 5b of the disk medium 5 placed on the receiving portion 4j is the bent portion 6c of the clamp 6. The disk medium 5 interposed between the hub 4 and the clamp 6 is securely clamped at the stage where the nut 9 is completely fastened.

  Therefore, in the above-described configuration, the shaft 3 and the hub 4 are fastened, and the clamp 6 is fixed to the male screw portion 4d formed on the outer periphery of the head 4h of the ceiling plate portion 4e of the hub 4 and screwed into this. Therefore, the screw head portion 7b of the clamp screw 7 is maintained while maintaining the length of the dynamic pressure bearing portion 8 as compared with the case using the clamp screw 7 shown in FIG. Further, the thickness dimension T of the clamp 6 and a part of the cylindrical portion 4a formed at the center of the hub 4 or a thickness dimension larger than that can be reduced from the height dimension of the disk drive A. . As a result, the disk drive B can be thinned.

  Further, in the above configuration, the means for generating the clamping force in the clamp 6 and clamping the disk medium 5 is a simple operation of fastening the nut 9, and the step portion 4 k is formed on the side wall portion 4 g of the hub 4. Therefore, overtightening of the nut 9 can be prevented. In addition, since the clamp 6 has a part of the side wall portion 4g above the ceiling plate portion 4e and the stepped portion 4k of the hub 4 inserted in the circular hole 6a, positioning becomes easy and assembling accuracy is easily secured. be able to. As a result, it is possible to provide the disk drive device B that can reliably hold the disk medium 5 and can obtain stable rotation.

  Further, in the above configuration, it is not necessary to form the small diameter portion 3a for fastening the clamp screw 7, and the clamp screw 7 and the small diameter portion 3a of the shaft 3 can be eliminated, and particularly, the labor for processing the shaft 3 is reduced. Can be achieved. As a result, the productivity, and hence the economy, can be improved. Further, by eliminating the small diameter portion 3a of the shaft 3, it is possible to increase the length of the hydrodynamic bearing portion 8, and it is possible to increase the rigidity of the disk drive device B for rotating the disk medium 5 at a constant high speed. become.

  As mentioned above, although the embodiment of the disk drive device according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof. For example, in the above embodiment, the step portion 4k is for preventing the nut 9 from being overtightened. However, the nut 9 is fastened until the clamp 6 comes into contact with the step portion 4k. And may be used to limit the installation position of the clamp 6. Further, since it is sufficient that the disc medium 5 can be securely clamped by the clamp 6 and the hub 4 together with the nut 9 being fastened, the stepped portion 4k may not be formed. Further, for fastening the shaft 3 and the hub 4, for example, the upper surface 3 d of the shaft 3 and the inner surface 4 f of the hub 4 may be bonded with an adhesive, and, for example, a protrusion protruding perpendicularly to the upper surface 3 d of the shaft 3 is provided. In addition to the provision, a fitting hole into which the protruding portion is fitted may be provided on the lower surface 4f of the hub 4 to be fastened. In this case, the inner surface of the fitting hole and the outer peripheral surface of the protrusion may be threaded and integrated with each other. Further, the hub 4, the clamp 6, the shaft 3, the bearing sleeve 2, and the nut 9 are made of stainless steel or aluminum metal, but may be made of other metals or resins.

  In the disk drive device B shown in the present embodiment, one disk medium 5 is sandwiched. However, the present invention is not limited to this. For example, a spacer is interposed between a plurality of disk media, and these disks are interposed. The medium may be sandwiched between the hub 4 and the clamp 6.

  Further, the size of the disk medium 5 sandwiched by the disk drive device B shown in the present embodiment is 1 inch or less. However, the disk drive device B of the present invention is a disk medium larger or smaller than 1 inch. It may be applied.

  Further, the disk drive device B shown in the present embodiment is used by being mounted on a magnetic disk device. In this case, the disk drive device B is attached to the tip of a swing arm or the like in addition to the disk drive device. A magnetic head that reads / writes magnetic data from / to the magnetic recording layer on the surface of the disk medium that is rotated at a constant high speed by the device, and an actuator (positioning device) for moving the magnetic head onto an arbitrary track of the disk medium. The magnetic disk device is housed in a semi-sealed state in the body. In the magnetic disk device, since the height of the disk drive device is one factor that determines the height of the magnetic disk device, the disk drive device B that can be thinned as shown in this embodiment is mounted. In addition, it is possible to reduce the thickness of the magnetic disk device.

1 is a side sectional view showing an embodiment of a disk drive device according to the present invention. It is a sectional side view of the conventional disk drive device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Bearing sleeve 3 Shaft 3a Small diameter part 4 Hub 4b Projection part 4d Male thread part 4e Ceiling board part 4g Side wall part 4h Head part 4j Reception part 4k Step part 5 Disc medium 6 Clamp 6c Bending part 7 Clamp screw 7a Screw part 7b Screw head 8 Dynamic pressure bearing 9 Nut H Height of disk drive

Claims (3)

A cylindrical bearing sleeve, a shaft rotatably supported in the bearing sleeve, and a receiving portion for holding the disk medium on the outer side of the bearing sleeve are formed to be overhanged. A disk drive device comprising a hub and a clamp for sandwiching the disk medium between the receiving portion of the hub,
The clamp is formed in a ring shape that is extrapolated to the head portion of the hub, and a male screw portion is formed on the outer periphery of the head portion of the hub, and a clamping force is applied to the clamp on the male screw portion. A disk drive device, wherein a nut for clamping the disk medium is screwed together. The disk drive apparatus according to claim 1, wherein
The disk drive device according to claim 1, wherein the hub includes a stepped portion having a diameter larger than that of the male screw portion below the male screw portion. A magnetic disk device comprising the disk drive device according to claim 1.

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