This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-020678, filed Feb. 12, 2021, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a disk device.
A hard disk drive (HDD) includes a housing, a drive motor, a disk-shaped magnetic recording medium supported and rotated by the drive motor, and the like.
In order to increase the capacity of the HDD, the number of pieces of magnetic recording media is increasing. As the number of pieces of magnetic recording media increases, the thickness of the magnetic recording medium becomes thinner. Therefore, when an impact is applied to the housing of the HDD from the outside, displacement occurs on the outer peripheral edge of the magnetic recording medium and stress concentrates on the central part of the magnetic recording medium, which may cause the magnetic recording medium to be damaged. As a result, writing to and reading from the magnetic recording medium cannot be performed any more.
In a case in which the magnetic recording medium is formed of glass, displacement occurs on the outer peripheral edge of the magnetic recording medium and stress concentrates on the central part of the magnetic recording medium, which may cause the magnetic recording medium to be broken.
Various embodiments will be described hereinafter with reference to the accompanying drawings.
In general, according to one embodiment, a disk device comprises: a base including a bottom wall and a side wall erected along a peripheral edge of the bottom wall and having a first corner and a second corner; a drive motor provided on the bottom wall; a plurality of disk-shaped magnetic recording media that are supported and rotated by the drive motor; a carriage comprising a head and supporting the magnetic head to be movable with respect to the magnetic recording medium; and a plurality of fixing members that each include a support post erected on the bottom wall and facing an outer peripheral edge of the magnetic recording medium, and a plurality of extending parts each extending from the support post between the magnetic recording media and facing the magnetic recording medium with a gap. The fixing members include: a first fixing member provided between the outer peripheral edge of the magnetic recording medium and the first corner; a second fixing member provided between the outer peripheral edge of the magnetic recording medium and the second corner; and a third fixing member provided on a side facing the first fixing member across the magnetic recording medium.
The disclosure is merely an example, and proper changes in keeping with the spirit of the invention, which are easily conceivable by a person of ordinary skill in the art, come within the scope of the invention as a matter of course. In addition, in some cases, in order to make the description clearer, the widths, thicknesses, shapes and the like, of the respective parts are illustrated schematically in the drawings, rather than as an accurate representation of what is implemented. However, such schematic illustration is merely exemplary, and in no way restricts the interpretation of the invention. In addition, in the specification and drawings, the same elements as those described in connection with preceding drawings are denoted by like reference numbers, and detailed description thereof is omitted unless necessary.
An HDD 10 according to a first embodiment is described.
As illustrated, the HDD 10 comprises a housing 8 having a rectangular box-shaped base 11 with an opened upper surface and a cover (not shown). The base 11 has a rectangular bottom wall 12 and a side wall 13 erected along a peripheral edge of the bottom wall 12, and is integrally molded. The cover is formed in, for example, a rectangular plate shape, and can be screwed onto the side wall 13 of the base 11 by screws (not shown) to seal the upper opening of the base 11. The housing 8 of the HDD 10 formed by sealing the base 11 with the cover is sealed with an inert gas such as helium (He) having a density lower than that of air. For example, aluminum (Al) is used as the base 11.
In the base 11, a spindle motor 20 (drive motor), a disk-shaped magnetic recording medium 30, a carriage assembly 40, a head 41, a voice coil motor (VCM) 45, a ramp member 50, a plurality of fixing members 60, and a board unit 80 are accommodated.
The spindle motor 20 is attached to the bottom wall 12 of the base 11 and functions as a drive motor. Plural pieces of the disk-shaped magnetic recording media 30 are provided, and supported and rotated by the spindle motor 20. The carriage assembly 40 is movably supported with respect to the magnetic recording medium 30, and is rotated and positioned by the VCM 45. The heads 41 are provided on one end side of the carriage assembly 40, and record and read information on and from the magnetic recording media 30. When the head 41 moves to the outermost periphery of the magnetic recording medium 30, the ramp member 50 holds the head 41 at a retracted position separated from the magnetic recording medium 30. A plurality of the fixing members 60 are provided in the vicinity of the magnetic recording medium 30. The board unit 80 includes a preamplifier and the like.
A printed circuit board (not shown) is screwed to an outer surface of the bottom wall 12 of the base 11. The printed circuit board constitutes a control unit that controls the operation of the spindle motor 20 and also controls the operations of the VCM 45 and the head 41 via the board unit 80.
In
As disk-shaped magnetic recording media, plural, for example, ten pieces of magnetic recording media 30 are arranged in the Z direction. The number of pieces of the magnetic recording media 30 is not limited to ten, and may be nine or less, or eleven or more. Each magnetic recording medium 30 is formed to have, for example, a diameter of 96 mm (about 3.5 inches), includes a base material formed of such as glass or aluminum and magnetic recording layers formed on an upper surface and a lower surface of the base material, and has recording surfaces on both surfaces.
As shown in
When the VCM 45 is energized, the carriage assembly 40 rotates about the bearing part 44 as a base axis, and the head 41 is moved and positioned at a desired position on the surface of the magnetic recording medium 30. As a result, the head 41 can write or read information to or from the magnetic recording medium 30.
The ramp member 50 is provided on the bottom wall 12 of the base 11 and constitutes a third fixing member 63 described later. The ramp member 50 has a plurality of uneven parts in the Z direction by having a plurality of extending parts 67 to be described later. When the HDD 10 is not operated, the head 41 moves away from the outer periphery of the magnetic recording medium 30. At this time, the head 41 is held in a recess of the ramp member 50 as a predetermined stop position.
As shown in
In the present embodiment, three members including a first fixing member 61, a second fixing member 62, and the third fixing member 63 are provided as the fixing members 60 in the housing 8, and are arranged around the magnetic recording medium 30.
As shown in
As shown in
The support post 66 is erected in the Z direction. For example, eleven pieces of the extending parts 67 are provided, which extend substantially parallel to the XY plane from the support post 66. The extending parts 67 are arranged substantially parallel to each other at predetermined intervals in the Z direction. Nine pieces of the extending parts 67 positioned between the uppermost extending part 67 and the lowermost extending part 67 in the Z direction each extend between two adjacent magnetic recording media 30 and face the outer peripheral edge of the magnetic recording medium 30 with a gap therebetween. That is, the HDD 10 has a portion in which the lowermost extending part 67, nine pieces of the magnetic recording media 30 and nine pieces of the extending parts 67 alternately arranged, the magnetic recording media 30, and the uppermost extending part 67 are arranged in this order in the Z direction. For example, in the XY plane, the extending part 67 is provided so as to overlap the outer peripheral edge of the magnetic recording medium 30 by a width d of about 0.5 to 1 mm. The gap in the Z direction between the extending part 67 and the outer peripheral edge of the magnetic recording medium 30 is set to, for example, about 0.3 mm.
As shown in
Similarly, the second fixing member 62 is provided between the outer peripheral edge of the magnetic recording medium 30 and the side wall 13 of the base 11, but is desirably provided at a position where the distance between the outer peripheral edge of the magnetic recording medium 30 and the side wall 13 is small. From the viewpoint of efficiently using the space in the HDD 10, the second fixing member 62 is desirably provided between a second corner 15 whose distance from the outer peripheral edge of the magnetic recording medium 30 is small among the corners in the base 11 and the outer peripheral edge of the magnetic recording medium 30.
The third fixing member 63 is provided on the side facing the first fixing member 61 across the spindle motor 20 in the XY plane. As described above, the third fixing member 63 in the present embodiment may also serve as the ramp member 50. Each of the spaces between the plurality of extending parts 67 of the third fixing member 63 is a space in which the outer peripheral edge of the magnetic recording medium 30 is arranged and a space in which the head 41 is held.
The HDD 10 according to the first embodiment may include a filter (not shown). The filter is arranged in the vicinity of the magnetic recording medium 30 and extends in the Z direction along the peripheral edge surface of the magnetic recording medium 30. With this configuration, the filter functions as a circulation filter that collects dust using a flow of air in the housing 10 and a flow of air in the vicinity of the side surface of the magnetic recording medium 30. In order to collect dust in the vicinity of each recording surface of the magnetic recording medium 30 by the flow of air, the filter has a height higher than the stacking height of the magnetic recording medium 30. In addition, the filter is provided near a corner inside the base 11 from a functional and spatial viewpoint.
As shown in
Functions and effects of the HDD 10 according to the first embodiment is described.
When an impact is applied to the housing 8 of the HDD 10 from the outside, there is a case in which the outer peripheral edge of the magnetic recording medium 30 is displaced in the Z direction. The HDD 10 according to the first embodiment is provided with plural pieces of the fixing members 60. Each fixing member 60 has the plurality of extending parts 67 extending from the support post 66 to the space between two adjacent magnetic recording media 30. Therefore, when an impact is applied to the HDD 10 from the outside, the displacement of the outer peripheral edge of the magnetic recording medium 30 in the Z direction can be suppressed by the extending part 67, and an amount of displacement can be reduced. Therefore, the stress generated in the central part of the magnetic recording medium 30 can be reduced, and damage to the magnetic recording layer of the magnetic recording medium 30 and the base material formed of glass can be suppressed.
In order to suppress the magnetic recording medium 30 from being displaced, for example, it is possible to provide a squeeze plate having an extending part that covers substantially the entire periphery of the outer peripheral edge of the magnetic recording medium 30. However, in the case of a squeeze plate covering substantially the entire periphery of the outer peripheral edge of the magnetic recording medium 30, there is a possibility that a portion is partially generated where the distance between the magnetic recording medium 30 and the extending part is different from other portions. Therefore, when the HDD is operated, there is a risk of wind turbulence occurring between the rotating magnetic recording medium 30 and the extending part to increase disc flutter.
On the other hand, by providing the plurality of fixing members 60 covering a part of the outer peripheral edge of the magnetic recording medium 30 as in the present embodiment, it is possible to suppress variations in the distance between the magnetic recording medium 30 and the extending part 67. Therefore, when the HDD is operated, wind turbulence generated between the rotating magnetic recording medium 30 and the extending part can be reduced. Therefore, the HDD 10 according to the present embodiment can suppress the disk flutter during operation.
As described above, according to the first embodiment, it is possible to obtain the disk device that can suppress generation of stress on the magnetic recording medium and suppressing damage to the magnetic recording medium.
Next, HDDs according to modifications and other embodiments are described. In the modifications and other embodiments described below, the same parts as those of the first embodiment described above are denoted by the same reference numerals as those of the first embodiment, and the detailed description thereof may be omitted or simplified.
As shown in
Because the extending part 67 of the fixing member 60 is formed in a pin shape, an area in which the magnetic recording medium 30 and the extending part 67 face each other is reduced as compared with the case in which the extending part 67 is formed in a plate shape. Therefore, it is possible to further suppress the portion where the distance between the magnetic recording medium 30 and the extending part 67 is different from that of other portions. Therefore, when the magnetic recording medium 30 is rotating, wind turbulence in the vicinity of the magnetic recording medium 30 can be reduced, and the disk flutter in which the magnetic recording medium 30 vibrates with the rotation can be suppressed.
In the first modification, eleven pieces of the extending parts 67 are arranged in a row in the Z direction so as to allow one piece of pin-shaped extending part 67 to be positioned above and below each magnetic recording medium 30. The pin-shaped extending parts 67 may be provided in plural numbers above and below the magnetic recording medium 30. According to the second modification, as shown in
The accuracy of the distance between the magnetic recording medium 30 and the extending part 67 is better in a case in which one piece of the pin-shaped extending part 67 is provided above and below the magnetic recording medium 30. However, the area that suppresses the displacement of the magnetic recording medium 30 increases by providing the extending parts 67 in plural numbers above and below the magnetic recording medium 30. Therefore, the displacement of the outer peripheral edge of the magnetic recording medium 30 in the Z direction can be more stably suppressed.
The number of the extending parts 67 of the fixing member 60 is not limited to eleven, and may be partially omitted.
As shown in
Furthermore, unlike the other magnetic recording media 30, the uppermost magnetic recording medium 30 is fixed by a clamp spring 21. The distance between the clamp spring 21 and the outer peripheral edge of the magnetic recording medium 30 is longer than the distance between the spacer ring 22 and the outer peripheral edge of the magnetic recording medium 30. Therefore, in a case in which the displacements in the Z direction generated at the outer peripheral edges of the magnetic recording media 30 are the same, the displacement angle of the uppermost magnetic recording medium 30 with respect to the XY plane is smaller than the displacement angles of the other magnetic recording media 30. Accordingly, in the third modification, the extending part 67 provided on the uppermost magnetic recording medium 30 is eliminated. Even in the case in which the extending part is omitted, the stress generated in the central part of the uppermost magnetic recording medium 30 is smaller than the stress generated in the other magnetic recording media 30, and destruction of the magnetic recording layer of the magnetic recording medium 30 and the base material formed of glass can be suppressed.
Further, in the third modification, the extending part located at the central part in the Z direction is eliminated. Even in the case of omitting this extending part, it is possible to suppress the displacement in the Z direction occurring at the outer peripheral edge of the magnetic recording medium 30.
As described above, with the configuration in which the extending parts 67 are partially omitted, the manufacturing cost of the fixing member 60 can be reduced.
As illustrated, an HDD 10 according to the second embodiment is different from the HDD 10 according to the first embodiment in that four fixing members 60 are provided on the outer peripheral edges of magnetic recording media 30.
The HDD 10 according to the second embodiment includes, as the fixing member 60, a first fixing member 61, a second fixing member 62, a third fixing member 63, and a fourth fixing member 64. The first fixing member 61 and the second fixing member 62 are similar to the first fixing member 61 and the second fixing member 62 in the first embodiment. Similarly to the first embodiment, the third fixing member 63 also serves as a ramp member 50. In the present embodiment, the fourth fixing member 64 also serves as a spoiler, for example.
The spoiler (fourth fixing member 64) has a function of regulating the flow of air accompanying the rotation of the magnetic recording medium 30, reducing wind turbulence in the vicinity of the magnetic recording medium 30, and suppressing the disc flutter in which the magnetic recording medium 30 vibrates accompanying the rotation. The spoiler includes a plate-shaped main body, a plurality of rectifying plates, and a fixed part, and is integrally molded with such as synthetic resin. The spoiler is arranged in the vicinity of the magnetic recording medium 30, and is screwed and fixed onto a bottom wall 12 of a base 11 by screwing a fixing screw (not shown) into a through hole provided in the fixed part. The plate-shaped main body is formed in the Z direction. For example, eleven pieces of the rectifying plates are provided, extend substantially parallel to the XY plane from the plate-shaped main body, and are arranged at predetermined intervals in the Z direction. Except for the uppermost and lowermost rectifying plates, other nine pieces of the rectifying plates extend between two adjacent magnetic recording media 30, and face the magnetic recording media 30 with a gap therebetween.
In the case of the spoiler also serving as the fourth fixing member 64, the plate-shaped main body of the spoiler is replaced by a support post 66, and the rectifying plate is replaced by an extending part 67.
Similarly to the HDD 10 according to the first embodiment, the first fixing member 61 and the second fixing member 62 may also serve as a filter holder.
At the outer peripheral edge of the magnetic recording medium 30, the second fixing member 62 is adjacent to the first fixing member 61 in the circumferential direction. The first fixing member 61 and the second fixing member 62 are arranged such that an angle α1 formed by a straight line connecting the first fixing member 61 and the center of the magnetic recording medium 30 (that is, a spindle motor 20) and a straight line connecting the second fixing member 62 and the center of the magnetic recording medium 30 is 100° or less.
At the outer peripheral edge of the magnetic recording medium 30, the third fixing member 63 is arranged adjacent to the second fixing member 62 in the circumferential direction. The second fixing member 62 and the third fixing member 63 are arranged such that an angle α2 formed by a straight line connecting the second fixing member 62 and the center of the magnetic recording medium 30 and a straight line connecting the third fixing member 63 and the center of the magnetic recording medium 30 is 100° or less.
At the outer peripheral edge of the magnetic recording medium 30, the fourth fixing member 64 is provided between the third fixing member 63 and the first fixing member 61. That is, the fourth fixing member 64 is adjacent to the third fixing member 63 and the first fixing member 61 in the circumferential direction.
The first fixing member 61 and the fourth fixing member 64 are arranged such that an angle α3 formed by a straight line connecting the first fixing member 61 and the center of the magnetic recording medium 30 and a straight line connecting the fourth fixing member 64 and the center of the magnetic recording medium 30 is 100° or less. The third fixing member 63 and the fourth fixing member 64 are arranged such that an angle α4 formed by a straight line connecting the third fixing member 63 and the center of the magnetic recording medium 30 and a straight line connecting the fourth fixing member 64 and the center of the magnetic recording medium 30 is 100° or less.
Functions and effects of the HDD 10 according to the second embodiment are described.
In each simulation, the thickness of the magnetic recording medium 30 in the Z direction is set to 0.635 mm, and the gap between the extending part 67 and the magnetic recording medium 30 in the Z direction is set to 0.3 mm. In addition, the external force applied to one magnetic recording medium 30 is set to 250 G, which is substantially the same as a case in which the external force is actually applied to the HDD 10.
When the stress applied to the magnetic recording medium 30 of the HDD 10 becomes about 95 MPa or more, the magnetic recording layer of the magnetic recording medium 30 is destroyed, and there is a possibility that data cannot be read and written. From the respective simulation results, the stress generated in the case of the angle α formed between the two adjacent fixing members 60 being 87.5° (
From the above simulation results, it can be seen that the stress applied to the magnetic recording medium 30 tends to reduce when the angle α formed by the two adjacent fixing members 60 is changed from 127.5° to 110°. Therefore, in order to reduce the stress applied to the magnetic recording medium 30, it is desirable to set the angle α formed by the two adjacent fixing members 60 to 120° or less. Furthermore, in order to suppress a value of the stress applied to the magnetic recording medium 30 to 95 MPa, it is more desirable to arrange the fixing members 60 such that the angle α formed by the two adjacent fixing members 60 is 100° or less. Therefore, it is desirable to provide the fixing members 60 at four or more locations in the circumferential direction at the outer peripheral edge of the magnetic recording medium 30.
As described above, by providing the fixing members 60 at four or more locations spaced apart from each other in the circumferential direction at the outer peripheral edge of the magnetic recording medium 30, and arranging the fixing members 60 such that the angle formed between the adjacent fixing members 60 is 100° or less, the damage of the magnetic recording medium and the damage of the magnetic recording layer can be suppressed even when the HDD receives the impact.
Also in the HDD according to the second embodiment, the first modification, the second modification, and the third modification described above can be applied. For example, the extending part of the fixing member 60 is not limited to a plate shape, and may be formed in a pin shape. Also in this configuration, the same operations and effects as those of the first embodiment and the first and second modifications can be obtained.
Furthermore, as described above, by providing the fixing members 60 at the outer peripheral edge of the magnetic recording medium 30 such that the angle formed between the adjacent fixing members 60 is 100° or less, it is possible to suppress destruction of the magnetic recording medium 30 due to application of the external force. Therefore, by providing, for example, five pieces of the fixing members 60, damage and destruction of the magnetic recording medium 30 can be further suppressed.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
For example, in the disk device, the number of pieces of magnetic disks and magnetic heads can be increased as necessary, and the size of the magnetic disk can be variously selected.
Number | Date | Country | Kind |
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2021-020678 | Feb 2021 | JP | national |