JP4703780B2 - Disk unit - Google Patents

Description

  Embodiments described herein relate generally to a disk device having a disk as a recording medium.

In recent years, disk devices such as magnetic disk devices and optical disk devices have been widely used as external recording devices for computers and image / music recording / reproducing devices.
For example, a hard disk drive (hereinafter referred to as HDD) generally drives a magnetic disk disposed in a housing, a spindle motor that supports and rotates the magnetic disk, a head actuator that supports the magnetic head, and a head actuator. A voice coil motor, a circuit board unit, and the like are provided.

  The housing includes a base on which a plurality of mechanism units are mounted and an upper surface that is open, and a top cover that covers the opening of the base. The top cover is screwed to the periphery of the upper surface of the base with a plurality of screws. Further, the bearing portion of the head actuator has a pivot, and this pivot is erected on the base, and its tip is screwed to the top cover. Thereby, the pivot is disposed in the housing in a state where the pivot is supported at both ends.

  In such a magnetic disk device, vibrations associated with the rotation of the spindle motor and the magnetic disk, vibrations of the head actuator due to turbulence associated with the rotation of the magnetic disk, vibrations associated with the seek operation of the head actuator, and the like occur. The vibrations of the spindle motor and the head actuator, which are the vibration generating units, are transmitted to the plate-shaped top cover via the base and the pivot of the head actuator. As a result, the top cover vibrates, causing noise.

  In view of this, a device has been proposed in which a rib or an aperture is formed on the top cover to improve the mechanical strength of the top cover and suppress vibrations of the top cover. For example, there is a device (for example, Patent Document 1) in which an arc-shaped rib or aperture concentric with the disk is formed in the top cover, or a device (for example, Patent Document 2) in which an opening is formed in the top cover immediately above the yoke. Proposed.

JP 2004-46964 A JP 2006-331545 A

  However, in recent years, it has been desired to reduce the size and thickness of information processing apparatuses, and as a result, there is an increasing demand for reducing the thickness of magnetic disk devices used in these information processing apparatuses. For this reason, it is conceivable that the top cover of the disk device is also formed thin and has insufficient rigidity. Furthermore, not only the primary mode vibration of the top cover but also noise generation due to the secondary mode vibration is also a problem.

  The present invention has been made in view of the above points, and an object thereof is to provide a disk device capable of reducing noise caused by vibration of a top cover.

A disk device according to an aspect of the present invention includes a housing having a base and a top cover combined with the base, and a motor that rotates around the rotation center and a pivot that serves as the rotation center of the head actuator.
The top cover has a first point corresponding to the rotation center of the motor, a second point corresponding to the pivot, and a direction extending in the longitudinal direction of the housing passing through the first point as an axis. A first rib having a shape having a first center of gravity is provided in a triangular region having a vertex at a third point which is a central portion of a side located on the opposite side to the second point with respect to the axis.

  According to the aspect of the present invention, it is possible to provide a disk device capable of reducing noise caused by vibration of the top cover.

FIG. 1 is an exploded perspective view showing an HDD according to a first embodiment of the present invention. FIG. 2 is a plan view of a top cover of the HDD. FIG. 3 is a diagram schematically showing a secondary mode vibration analysis result of the top cover. FIG. 4 is a plan view showing a top cover according to a comparative example having no first rib. FIG. 5 is a diagram showing the relationship between frequency and vibration for the top cover according to the present embodiment and the top cover according to the comparative example. FIG. 6 is a plan view showing a top cover of an HDD according to the second embodiment of the present invention. FIG. 7 is a plan view showing a top cover of an HDD according to a third embodiment of the present invention. FIG. 8 is a plan view showing a top cover of an HDD according to the fourth embodiment of the present invention. FIG. 9 is a plan view showing a top cover of an HDD according to a fifth embodiment of the present invention.

Hereinafter, a hard disk drive (hereinafter referred to as HDD) according to a first embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the HDD includes a sealed flat rectangular housing 10. The housing 10 includes a rectangular box-shaped base 12 having an upper surface opening and a rectangular plate-shaped top cover 14. The top cover 14 is screwed to the base 12 by a plurality of screws 11, and the upper surface opening of the base is formed. Occlude.

  Within the base 12 are two magnetic disks 16 as recording media, a spindle motor 18 that supports and rotates the magnetic disks, a plurality of magnetic heads 17 that record and reproduce information on the magnetic disks, and these magnetic heads 17. Head actuator 20 that is movably supported with respect to the magnetic disk 16, a voice coil motor (hereinafter referred to as VCM) 24 that rotates and positions the head actuator, and the magnetic head when the magnetic head moves to the outermost periphery of the magnetic disk. Is loaded with a ramp loading mechanism 25 that holds the head actuator 20 at a position away from the magnetic disk, an inertia latch mechanism 26 that holds the head actuator 20 in the retracted position when an impact is applied to the HDD, and a flexible print on which electronic components such as a preamplifier are mounted. Circuit board unit (FPC) Referred to as the unit) 21 is housed.

  A printed circuit board (not shown) that controls the operations of the spindle motor 18, the VCM 24, and the magnetic head 17 via the FPC unit 21 is screwed to the outer surface of the base 12, and is positioned facing the bottom wall of the base 12. Yes.

  Each magnetic disk 16 is formed with a diameter of 65 mm (2.5 inches), for example, and has a magnetic recording layer on the upper surface and the lower surface. The magnetic disk 16 is coaxially fitted to a hub (not shown) of the spindle motor 18 and is clamped by a clamp spring 27 to be fixed to the hub. The magnetic disk 16 is rotated at a predetermined speed by a spindle motor 18 as a drive unit.

  The head actuator 20 includes a bearing assembly 28 fixed on the bottom wall of the base 12. The bearing assembly 28 that functions as a bearing portion includes a pivot 23 erected on the bottom wall of the base 12, and a cylindrical hub that is rotatably supported on the pivot 23 via a pair of bearings. Yes. The head actuator 20 includes four arms 22 attached to the hub, four suspensions 30 extending from the respective arms, a magnetic head 33 supported on the extended end of the suspension, and a plurality of spacer rings. Yes.

  Each magnetic head 33 has a substantially rectangular slider (not shown) and an MR (magnetic resistance) head element for recording / reproduction formed on the slider, and is fixed to a gimbal portion formed at the tip of the suspension 30. ing. Each magnetic head 33 is electrically connected to a main FPC 21b described later via a relay flexible printed circuit board (hereinafter referred to as a relay FPC) (not shown). Thereby, each magnetic head 33 is electrically connected to the FPC unit 21 via the relay FPC and the main FPC 21b.

  The four arms 22 are located in parallel with each other at a predetermined interval, and the suspension 30 and the magnetic head 33 attached to these arms are located facing each other. The VCM 24 includes a support frame (not shown) extending from the hub of the bearing assembly 28 in the direction opposite to the arm 27 and a voice coil supported by the support frame. When the head actuator 20 is incorporated in the base 12, the voice coil is positioned between a pair of yokes 62 fixed on the base 12, and constitutes the VCM 24 together with these yokes and a magnet (not shown) fixed to one of the yokes. is doing. When the voice coil is energized, the head actuator 20 rotates around the pivot 23 and the magnetic head 33 is moved and positioned on a desired track of the magnetic disk 16.

  The ramp loading mechanism 25 includes a ramp 64 provided on the bottom wall of the base 12 and disposed outside the magnetic disk 16, and a tab extending from the tip of each suspension 30. When the head actuator 20 rotates and the magnetic head 17 rotates to the retracted position outside the magnetic disk 16, each tab engages with the ramp surface formed on the ramp 64, and then is lifted by the ramp surface inclination. The magnetic head 17 is unloaded.

  The FPC unit 21 has a main body 21 a formed of a flexible printed circuit board, and the main body 21 a is fixed to the bottom wall of the base 12. Electronic components such as a head amplifier and a connector are mounted on the main body 21a. The FPC unit 21 has a main FPC 21b extending from the main body 21a. The extended end of the main FPC 21b is electrically connected to the magnetic head 17 via the relay FPC.

  The HDD operates by operating a circulating filter 66 that captures and removes contaminants such as dust, moisture, and gas components contained in the outside air flowing from the breathing holes formed in the top cover 14 or the bottom wall of the base 12, and a movable part. A breathing filter 67 for capturing dust generated in the housing 10 is provided. The circulation filter 66 and the breathing filter 67 are disposed around the magnetic disk 16.

  FIG. 2 is a plan view showing the configuration of the top cover of the HDD. As shown in FIGS. 1 and 2, the rectangular top cover 14 is formed, for example, by press-molding an aluminum alloy plate having a thickness of about 0.4 mm. A first through hole 40 is formed in each of the four corners of the top cover 14 and substantially the center of the pair of long side edges. The top cover 14 is fastened to the base by screwing the screws 11 inserted into the first through holes 40 into screw holes formed in the peripheral edge of the base 12, and closes the upper surface opening of the base 12. The top cover 14 faces the magnetic disk 16 substantially in parallel with a predetermined gap.

  In the top cover 14, a second through hole 42 is formed at a position facing the pivot 23 of the bearing assembly 28. A part of the top cover 14 and the pivot 23 are fastened by screwing the fixing screw 13 inserted through the second through hole 42 into the upper end portion of the pivot 23. Therefore, both ends of the pivot 23 are supported by the base 12 and the top cover 14 of the housing 11. As described above, the top cover 14 includes the six first through holes 40 for screwing located on the peripheral edge and the second through holes 42 for screwing located on the pivot 23.

  The top cover 14 is press-molded so as to form a convex portion that protrudes outward in FIG. 1 except for its peripheral edge. The six first through holes 40 are respectively formed on the peripheral edge portion of the top cover 14. In addition, a plurality of ribs, which will be described in detail later, are formed on the top cover 14 by drawing in order to increase the rigidity of the top cover.

  For an HDD having a top cover that does not have ribs, which will be described later, with a spindle motor idling at, for example, 5400 rpm, at a position 1 cm away from the surface of the top cover 14 in a vertical direction, for example, at 12 locations. The pressure level was measured.

  FIG. 3 shows a simulation analysis result of the vibration mode of the top cover 14 using the finite element method. In the figure, a dark region (first region) A1 located at the center of the striped gradation is a region where the secondary mode vibration amplitude of the top cover 14 is the largest, and this secondary natural frequency is about 1.4 kHz. is there. This result was a result in which both the sound pressure peak frequency and the sound generation position in the above measurement result coincided. From this, when the spindle motor rotates, the vibration caused by the rotation of the motor is transmitted to the top cover 14, and the first area A1 vibrates like a drum, generating noise. In addition, the region where the primary mode vibration amplitude is the largest is located approximately at the rotation center C <b> 2 of the spindle motor 18.

  Therefore, in this embodiment, the first rib having the center C1 in the first region A1 is formed on the top cover 14 by drawing, and further the second rib for increasing the rigidity of the second region A2 is drawn. Therefore, the vibration of the top cover is suppressed and the noise reduction effect is obtained.

  More specifically, as shown in FIG. 3, in the top cover 14, the axis that passes through the rotation center C <b> 2 of the spindle motor 18 and extends in the longitudinal direction of the housing 10 is the first axis Y, and the rotation center C <b> 2 of the spindle motor 18. And the axis orthogonal to the first axis Y is the second axis X, the rotation center C2 of the spindle motor 18, the center of the second through hole 42, and the first through hole 40 within the first axis Y. On the other hand, the triangular region B1 having the apex of the first through-hole 40 located on the opposite side of the second through-hole 42 and located at the center of the side edge on the long side of the top cover 14 is the above-described 2. It almost coincides with the region A1 having the largest next mode vibration amplitude. Further, when the first through hole 40 is displaced from the central portion of the long side of the top cover 14 or does not exist, the rotation center C2 of the spindle motor 18, the center of the second through hole 42, and the first axis On the other hand, a triangular area B2 having the long side longitudinal center D located on the opposite side of the second through hole as an apex substantially coincides with the above-described area A1 having the largest secondary mode vibration amplitude.

  The top cover 14 has a center C1 inside the region B1 or the region B2, or a center of gravity (open curve or partially closed) of a closed curve shape, an open curve shape, or a polygonal shape of the first rib 50, which will be described later. In the case of a non-polygon, the first rib 50 having a shape having the area centroid of the closed region formed by connecting the closest ends is formed by drawing. In the present embodiment, the top cover 14 has a plurality of circles or arc-shaped first ribs 50 having different diameters formed concentrically with respect to the center C1 in the region B1 or the region B2. . The innermost first rib 50 is formed in a circular shape as a closed curve, and the two outer first ribs 50 are each formed in an arc shape. The plurality of first ribs 50 are formed with an equal width. The plurality of first ribs 50 may be formed with different widths.

  The shape of the first rib 50 is not limited to a circular shape as a closed curve or an arc shape as an open curve, but may be an ellipse, another curved shape, or an open curved shape having an ellipse or a curved shape in part. The first rib 50 may have a closed curve shape or an open curve shape in which a line segment or a bending point exists in part. Further, the first rib 50 may have a polygonal shape (including a case where the first rib 50 is not partially closed).

  As shown in FIGS. 1 and 2, the top cover 14 reduces the primary vibration amplitude of the top cover around the rotation center C2 of the spindle motor 18 in the vicinity of the region where the primary mode vibration amplitude is the largest. Two ribs 52 are provided. In the present embodiment, the second rib 52 is drawn into an arc shape centered on the rotation center C <b> 2 of the spindle motor 18. The top cover 14 has a plurality of arc-shaped second ribs 52 that are concentrically drawn about the rotation center C2 of the spindle motor 18 and have different diameters.

  The second rib 52 located on the innermost peripheral side is formed in a circular shape and separated from the first rib 50. The outer two second ribs 52 are each formed in an arc shape and are further continuous with the first rib 50. The plurality of second ribs 52 are formed with an equal width. The plurality of second ribs 52 may be formed with different widths. Further, the shape of the second rib 52 is not limited to the arc shape like the shape of the first rib, and may be other shapes such as a polygonal shape. Furthermore, the arc shape is not limited to a perfect circle but includes an ellipse or a curved shape.

  According to the HDD having the top cover 14 configured as described above, by providing the top cover 14 with a rib having a shape centered in a region where the vibration amplitude of the secondary mode is large, the secondary of the top cover 14 is provided. Mode vibration can be suppressed, and noise caused by vibration of the top cover can be reduced. Further, by providing the second rib on the top cover 14, in addition to the vibration of the secondary mode, the vibration of the primary mode can be suppressed, and noise caused by the vibration of the top cover can be further reduced. It becomes possible.

  FIG. 4 shows a top cover according to a comparative example that does not include the first rib. FIG. 5 shows a comparison of the change in vibration amplitude with respect to the frequency at the center C1 for the top cover 14 in the HDD according to the present embodiment and the top cover according to the comparative example. As shown in FIG. 5, in the top cover of the HDD according to the present embodiment, it can be seen that the vibration amplitude of the secondary mode near 1600 Hz is significantly reduced as compared with the comparative example. It can be seen that a noise reduction effect can be obtained by such vibration reduction.

Next, a top cover of an HDD according to another embodiment of the present invention will be described.
FIG. 6 shows the top cover 14 of the HDD according to the second embodiment. According to the second embodiment, the top cover 14 has a plurality of first ribs 50 and second ribs 52 formed by drawing. One second rib 52 is provided, and is formed in an arc shape or a C shape concentric with the rotation center C2 of the spindle motor. Further, the second rib 52 is formed to be wider than the first rib 50. The second rib 52 is formed so as to protrude toward the upper surface side of the top cover 14 or protrude toward the lower surface side of the top cover 14, that is, the magnetic disk side.

In the second embodiment, the other configuration of the HDD is the same as that of the first embodiment described above, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.
According to the second embodiment, the same function and effect as those of the first embodiment described above can be obtained. Further, the first rib 50 does not interfere with the second rib 52, and the first and second ribs can be easily formed.
If the noise reduction effect by the first rib 50 is sufficiently obtained, the second rib 52 can be omitted. In this case, the manufacturing cost of the top cover can be reduced.

  According to the top cover of the HDD according to the third embodiment shown in FIG. 7, the plurality of second ribs 52 having different concentric diameters from the rotation center C2 of the spindle motor are opposed to the center portion of the spindle motor. Formed in position. According to such a configuration, the same effects as those of the first embodiment described above can be obtained, and the effect of improving the push-down strength of the top cover 14 can be obtained. Further, since the central portion of the spindle motor is the antinode of the primary vibration mode of the top cover 14, a further noise reduction effect can be obtained by the second rib.

In the third embodiment, the other configuration of the HDD is the same as that of the first embodiment described above, and the same reference numerals are given to the same portions, and detailed description thereof is omitted.
FIG. 8 shows the top cover 14 of the HDD according to the fourth embodiment. According to the fourth embodiment, the top cover 14 has one arc-shaped first rib 50 and one arc-shaped second rib 52 formed by drawing. The first rib 50 is formed in an arc shape or a C shape having the center C1 in the above-described region B1 or B2.

  One second rib 52 is provided, and is formed in an arc shape or a C shape concentric with the rotation center C2 of the spindle motor. Further, the second rib 52 is formed to be wider than the first rib 50. The second rib 52 is formed so as to protrude toward the upper surface side of the top cover 14 or protrude toward the lower surface side of the top cover 14, that is, the magnetic disk side.

In the fourth embodiment, the other configuration of the HDD is the same as that of the first embodiment described above, and the same reference numerals are given to the same portions, and detailed description thereof is omitted.
According to the fourth embodiment, the same operational effects as those of the first embodiment described above can be obtained. Further, the first rib 50 does not interfere with the second rib 52, and the first and second ribs can be easily formed. If the noise reduction effect by the first rib 50 is sufficiently obtained, the second rib 52 can be omitted.

The shape of the first rib 50 is not limited to a closed curve shape, an open curve shape, or an arc shape, but may be other shapes such as a polygon shape or a shape in which a part of the polygon is interrupted. According to the HDD of the fifth embodiment shown in FIG. 9, the top cover 14 has a plurality of first ribs 50 and arc-shaped second ribs 52 formed by drawing. The plurality of first ribs 50 are formed in a plurality of triangular shapes having the concentric center C1 or the area center of gravity in the above-described region B1 or B2. The outer first rib 50 is not a perfect triangle, but is formed in a shape in which one vertex is open.
One second rib 52 is provided, and is formed in an arc shape or a C shape concentric with the rotation center C2 of the spindle motor.

  In the fifth embodiment, the other configuration of the HDD is the same as that of the first embodiment described above, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted. Also in the fifth embodiment, the same operational effects as those of the first embodiment described above can be obtained.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  For example, the shape and number of the first ribs and the second ribs formed on the top cover are not limited to the above-described embodiment, and can be changed as necessary. The present invention is not limited to a 2.5-inch HDD, but can also be applied to a 3.5-inch or 1.8-inch HDD. Further, the number of magnetic disks is not limited to two, and can be applied to one or three or more disk devices. The material of the top cover and other components is not limited to the embodiment and can be changed as appropriate.

The present invention has been described in detail above with reference to the embodiments. For easy understanding of the present invention, specific embodiments of the present invention will be described below.
(Appendix 1) A base having a top surface opening, and a casing having a rectangular plate top cover screwed to the base and closing the top surface opening;
A drive motor for driving a disk-shaped recording medium in the housing;
A head actuator that supports a head for writing information to and reading information from the magnetic disk so as to be rotatable around a pivot fixed to the base and the top cover;
The top cover is provided at four corners, a central portion of a side edge on each long side, and a plurality of first through holes through which screws for fastening the top cover and the base are respectively inserted, and the top cover. A second through hole through which a screw is provided for fastening the top cover to the pivot,
A first axis that passes over the rotation center of the drive motor and extends in the longitudinal direction of the housing; a second axis that passes over the rotation center of the drive motor and is orthogonal to the first axis;
The rotation center of the drive motor, the center of the second through hole, and the center of the long side edge located on the opposite side of the second through hole with respect to the first shaft among the plurality of first through holes. At least one first rib having a shape having a first center in a triangular region having a vertex at the first through hole located in the portion;
A disk device comprising:
(Appendix 2) A base having a top surface opening, and a casing having a rectangular plate-like top cover that is screwed to the base and closes the top surface opening;
A drive motor for driving a disk-shaped recording medium in the housing;
A head actuator that supports a head for writing information to and reading information from the magnetic disk so as to be rotatable about a pivot fixed to the base and the top cover;
The top cover is provided at four corners, a central portion of a side edge on each long side, and a plurality of first through holes through which screws for fastening the top cover and the base are respectively inserted, and the top cover. A second through hole through which a screw is provided for fastening the top cover to the pivot,
A first axis extending in the longitudinal direction of the housing through the rotation center of the drive motor, a second axis passing through the rotation center of the drive motor and orthogonal to the first axis;
A triangular shape having apexes at the rotation center of the drive motor, the center of the second through hole, and the longitudinal central portion of the long side located on the opposite side of the second shaft with respect to the first axis And a first rib having a first center in the region.

10 ... Case, 12 ... Base, 14 ... Top cover, 16 ... Magnetic disk,
17 ... Magnetic head, 18 ... Spindle motor, 20 ... Head actuator,
22 ... Arm, 23 ... Pivot, 28 ... Bearing assembly, 40 ... First through hole, 42 ... Second through hole,
50 ... 1st rib, 52 ... 2nd rib, C1 ... 1st center, C2 ... 2nd center

Claims (9)

A housing having a base and a top cover combined with the base, the motor rotating at the rotation center, and the pivot serving as the rotation center of the head actuator;
The top cover is
A first point corresponding to the rotation center of the motor;
A second point corresponding to the pivot axis;
A third point that is a central portion of a side located on the opposite side of the second point with respect to the axis when the axis extends in the longitudinal direction of the housing through the first point;
A disk device comprising a first rib having a first center of gravity in a triangular area having a vertex as a vertex. The top cover has at least one first through hole through which a screw for fastening the top cover and the base is inserted, and a screw that is provided to face the pivot and fastens the top cover to the pivot. A second through hole,
The disk device according to claim 1, wherein the second point of the triangle is the center of the second through hole.   3. The disk device according to claim 2, wherein the third point of the triangle is a first through hole located at a substantially central portion in the longitudinal direction on the long side of the top cover.   4. The disk device according to claim 1, wherein the first rib has an arc shape having a first center of gravity in the triangular area. 5.   4. The disk device according to claim 1, wherein each of the top covers includes a plurality of first ribs having a concentric shape and having a first center of gravity in the triangular region.   The first center of gravity of the first rib is a first region where the secondary mode vibration of the top cover is generated, and the top is larger than the secondary mode vibration generated in a region outside the first region. The disk device according to claim 1, wherein the disk device is located in a first region where a secondary mode vibration of the cover is generated.   The disk device according to claim 1, wherein the top cover further includes an arc-shaped second rib having a second center of gravity different from the first center of gravity.   The disk device according to claim 7, wherein the second rib has an arc shape having a second center of gravity at a rotation center of the recording medium.   The second rib is a second region in which the primary mode vibration of the top cover is generated, and is larger than the primary mode vibration of the top cover generated in a region outside the second region. 9. The disk device according to claim 7, wherein the disk device is provided in a second area where mode vibration occurs.

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