Disk drive
The disk drive design addresses the issue of cover gaps by using an inclined constraining layer and viscoelastic dampers to dampen vibrations, maintaining structural integrity and reducing mechanical stress.
Patent Information
- Application Number
- JP2024100400
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-06-21
- Publication Date
- 2026-01-08
AI Technical Summary
The constraining layer attached to the first cover of a disk drive protrudes perpendicularly, creating a space that can cause stress due to gas expansion or contraction, leading to a gap between the first and second covers.
A disk drive design with a constraining layer inclined relative to the first cover surface, using adhesives to secure it, and dampers with viscoelastic materials to mitigate vibration-induced gaps by converting energy into heat.
The solution effectively suppresses the formation of gaps between covers by damping vibrations, ensuring structural integrity and reducing mechanical stress.
Smart Images
Figure 2026002420000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a disk drive. [Background technology]
[0002] A disk drive such as a hard disk drive (HDD) has a magnetic disk, a magnetic head that reads and writes information from and to the magnetic disk, and a housing that houses various components. In some disk drives, the housing has a base, a first cover that closes the space inside the base, and a second cover that covers the first cover.
[0003] The disk drive may further include a damper, which is disposed, for example, in the gap between the first cover and the second cover. The damper includes a constraining layer and an adhesive material that attaches the constraining layer to the first cover, and damps vibrations by deformation of the adhesive material. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] U.S. Patent No. 6,529,345 Summary of the Invention [Problem to be solved by the invention]
[0005] The constraining layer may be attached to the first cover so as to protrude substantially perpendicularly from the surface of the first cover. In this case, a space is formed between the side of the constraining layer, the surface of the first cover, and the second cover. The expansion or contraction of gas in the space may apply stress to the second cover.
[0006] One example of a problem to be solved by the present invention is to provide a disk drive that can suppress the occurrence of a gap between a first cover and a second cover. [Means for solving the problem]
[0007] A disk drive according to one embodiment includes a magnetic disk, a housing, a constraining layer, and a first adhesive. The housing has a base with a storage space in which the magnetic disk is placed, a first cover attached to the base so as to close the storage space, and a second cover attached to the base so as to cover the first cover. The constraining layer has a first surface facing the first cover and a second surface located on the opposite side of the first surface, facing the second cover, and inclined relative to the first surface. The first adhesive is interposed between the first surface and the first cover. [Brief explanation of the drawings]
[0008] [Figure 1] FIG. 1 is an exemplary perspective view showing an exploded HDD according to an embodiment. [Figure 2] FIG. 2 is an exemplary perspective view showing the HDD of the above embodiment with the inner cover and outer cover removed. [Figure 3] FIG. 3 is an exemplary cross-sectional view showing a part of the HDD of the above embodiment. [Figure 4] FIG. 4 is an exemplary cross-sectional view showing another part of the HDD of the above embodiment. [Figure 5] FIG. 5 is an exemplary cross-sectional view showing a part of the HDD in the vicinity of the mounting portion of the embodiment. [Figure 6] FIG. 6 is an exemplary cross-sectional view showing a part of an HDD in the vicinity of another mounting portion of the embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0009] An embodiment will be described below with reference to FIGS. 1 to 6. In this specification, components according to the embodiment and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.
[0010] In the following description, "inhibit" is defined as, for example, preventing an event, action, or effect from occurring or reducing the magnitude of an event, action, or effect.
[0011] 1 is an exemplary exploded perspective view of a hard disk drive (HDD) 10 according to this embodiment. The HDD 10 is an example of a disk device, and may also be called an electronic device, a storage device, an external storage device, or a magnetic disk device.
[0012] As shown in the drawings, for convenience, the X-axis, Y-axis, and Z-axis are defined in this specification. The X-axis, Y-axis, and Z-axis are perpendicular to one another. The X-axis is aligned along the width of the HDD 10. The Y-axis is aligned along the length of the HDD 10. The Z-axis is aligned along the thickness of the HDD 10.
[0013] Furthermore, in this specification, the X direction, Y direction, and Z direction are defined. The X direction is a direction along the X axis, and includes the +X direction indicated by the X axis arrow and the -X direction opposite to the X axis arrow. The Y direction is a direction along the Y axis, and includes the +Y direction indicated by the Y axis arrow and the -Y direction opposite to the Y axis arrow. The Z direction is a direction along the Z axis, and includes the +Z direction indicated by the Z axis arrow and the -Z direction opposite to the Z axis arrow.
[0014] As shown in Figure 1, HDD 10 has a housing 11 that houses various components. Housing 11 has a base 15, an inner cover 16, and an outer cover 17. Inner cover 16 is an example of a first cover. Outer cover 17 is an example of a second cover.
[0015] The base 15 and the outer cover 17 are made of a metal such as an aluminum alloy. The inner cover 16 is made of a metal such as a non-magnetic stainless steel. That is, the base 15, the inner cover 16, and the outer cover 17 are non-magnetic. However, the base 15, the inner cover 16, and the outer cover 17 may be made of other materials or may be ferromagnetic.
[0016] The base 15 is a bottomed container that opens in the +Z direction. The base 15 extends in the Y direction. In other words, the length of the base 15 in the Y direction is longer than the length of the base 15 in the X direction and is also longer than the length of the base 15 in the Z direction.
[0017] 2 is an exemplary perspective view showing the HDD 10 of this embodiment with the inner cover 16 and the outer cover 17 removed. As shown in FIG.
[0018] The bottom wall 21 is formed in a substantially rectangular (quadrilateral) plate shape extending along the XY plane. The bottom wall 21 has a bottom surface 21a. The bottom surface 21a faces substantially in the +Z direction as a whole. The bottom surface 21a may have projections and recesses.
[0019] The sidewalls 22 protrude from the edges of the bottom surface 21a in approximately the +Z direction. The sidewalls 22 are formed in a substantially rectangular frame shape. The bottom surface 21a and the frame-shaped sidewalls 22 form (define, partition) a storage space S inside the base 15. In other words, the storage space S is provided inside the bottom surface 21a and the sidewalls 22 of the base 15. The storage space S is open to the outside of the base 15 at an end of the base 15 in the +Z direction.
[0020] 3 is an exemplary cross-sectional view showing a portion of the HDD 10 of this embodiment. As shown in FIG. 3, the side wall 22 has an end surface 22a, a mounting surface 22b, an inner surface 22c, and an intermediate surface 22d. Note that the side wall 22 is not limited to this example.
[0021] The end surface 22a is provided at the end of the side wall 22 in the +Z direction. The end surface 22a is formed to be approximately flat and faces approximately in the +Z direction. The end surface 22a is formed in the shape of a substantially rectangular frame. In other words, the end surface 22a is formed in an endless shape.
[0022] The mounting surface 22b is surrounded by the end surface 22a in a projection plane projected in the Z direction. The mounting surface 22b is located near the end surface 22a in the Z direction and is closer to the bottom surface 21a than the end surface 22a. In other words, the mounting surface 22b is recessed from the end surface 22a in approximately the -Z direction.
[0023] The mounting surface 22b is formed to be substantially flat and faces substantially in the +Z direction. The mounting surface 22b is formed in a substantially rectangular frame shape. However, the mounting surface 22b is not limited to this example. As shown in FIG. 2, a plurality of screw holes 23 are provided in the mounting surface 22b.
[0024] 3, the inner surface 22c is provided between the inner edge of the mounting surface 22b and the bottom surface 21a. The inner surface 22c faces the inside of the accommodation space S. The middle surface 22d is provided between the inner edge of the end surface 22a and the outer edge of the mounting surface 22b.
[0025] In other words, the side wall 22 has a rib 24 that protrudes substantially in the +Z direction from the mounting surface 22b. The rib 24 is formed in a substantially rectangular frame shape. The rib 24 has an end surface 22a and an intermediate surface 22d.
[0026] The housing 11 further includes a gasket 25. The inner cover 16 is supported on the mounting surface 22b of the side wall 22, for example, via the gasket 25. The gasket 25 airtightly seals the gap between the mounting surface 22b and the inner cover 16.
[0027] 1, the housing 11 further has a plurality of screws 26. The screws 26 penetrate the inner cover 16 and are fitted into the screw holes 23. That is, the inner cover 16 is attached to the attachment surface 22b by the screws 26. In this way, the inner cover 16 is attached to the base 15 so as to seal the storage space S substantially airtightly.
[0028] 3, the outer cover 17 covers the inner cover 16 with a gap G therebetween and is supported by the end surface 22a. In other words, a gap G is provided between the inner cover 16 and the outer cover 17. In this embodiment, the edge of the outer cover 17 is welded to the end surface 22a of the side wall 22 of the base 15 along the entire periphery. As a result, the outer cover 17 is attached to the base 15 so as to airtightly close the storage space S and the gap G. In other words, the inner cover 16 and the outer cover 17 seal the storage space S.
[0029] The outer cover 17 may be joined to other portions of the base 15. For example, the outer cover 17 may have a portion that surrounds the side wall 22 and be joined to the side wall 22 at that portion. The outer cover 17 may also be attached to the base 15 by other methods, such as adhesive.
[0030] 1, a ventilation hole 27 is provided in the inner cover 16. The ventilation hole 27 is an example of a first ventilation hole. The ventilation hole 27 penetrates the inner cover 16 substantially in the Z direction, and connects the storage space S and the gap G.
[0031] A vent hole 28 is provided in the outer cover 17. The vent hole 28 is an example of a second vent hole. The vent hole 28 penetrates the outer cover 17 substantially in the Z direction, and connects the gap G with the outside of the housing 11.
[0032] When assembling the HDD 10, air is removed from the storage space S and the gap G through the ventilation holes 27, 28. Furthermore, the storage space S and the gap G are filled with a gas other than air. The gas filled in the storage space S and the gap G is, for example, a low-density gas with a lower density than air, or an inert gas with low reactivity. For example, helium is filled in the storage space S and the gap G. Note that other fluids may also be filled in the storage space S.
[0033] The housing 11 further has a seal 29. The seal 29 is an example of a sealing material. The seal 29 is attached to the outer cover 17 and closes the ventilation hole 28. The seal 29 airtightly seals the ventilation hole 28, and prevents the gas filled in the storage space S from leaking out through the ventilation holes 27, 28.
[0034] As shown in FIG. 2, the HDD 10 further includes a plurality of magnetic disks 31, a spindle motor 32, a head stack assembly (HSA) 33, and a voice coil motor (VCM) .
[0035] The magnetic disk 31, spindle motor 32, HSA 33, and VCM 34 are disposed in the accommodation space S. Therefore, the bottom surface 21a of the base 15 faces the magnetic disk 31, spindle motor 32, HSA 33, and VCM 34. Furthermore, the sidewall 22 surrounds the magnetic disk 31, spindle motor 32, HSA 33, and VCM 34.
[0036] The magnetic disk 31 is a recording medium having magnetic recording layers on its upper and lower surfaces, for example. The diameter of the magnetic disk 31 is 3.5 inches, for example. However, the magnetic disk 31 is not limited to this example.
[0037] 3, the magnetic disks 31 are arranged along the XY plane. The multiple magnetic disks 31 are stacked at intervals in the Z direction. The HDD 10 of this embodiment has ten or more magnetic disks 31 arranged in the Z direction. Note that the number of magnetic disks 31 is not limited to this example.
[0038] The spindle motor 32 supports the magnetic disks 31 and rotates them about a central axis Axd. The central axis Axd is an example of a first rotation axis. The central axis Axd is the central axis of the magnetic disks 31 and also the central axis of rotation of the magnetic disks 31.
[0039] The plurality of magnetic disks 31 are held on the hub of the spindle motor 32 by, for example, clamp springs. The spindle motor 32 is attached to the bottom wall 21 of the base 15 and supported by the inner cover 16, for example.
[0040] 2, the HSA 33 has a carriage 35 and a plurality of head gimbal assemblies (HGA) 36. The carriage 35 has an actuator block 41, a plurality of arms 42, and a holder 43.
[0041] 4 is an exemplary cross-sectional view showing another portion of the HDD 10 of this embodiment. For example, a support shaft 44 is provided at a position spaced apart from the magnetic disk 31 in a direction substantially perpendicular to the Z direction. As shown in FIG. 4, the support shaft 44 extends from the bottom wall 21 in substantially the +Z direction and is supported by the inner cover 16.
[0042] The actuator block 41 is attached to a support shaft 44 via a bearing, for example, so as to be rotatable about a central axis Axh. The central axis Axh is an example of a second rotation axis. The central axis Axh is the central axis of the support shaft 44 and also the central axis of rotation of the carriage 35. The central axes Axd and Axh extend substantially parallel to the Z direction.
[0043] 2 protrude from the actuator block 41 in a direction substantially perpendicular to the Z direction, generally parallel to each other. The arms 42 are arranged at intervals in the Z direction. Each of the arms 42 is formed in a plate shape that can enter between two adjacent ones of the magnetic disks 31. The holder 43 protrudes from the actuator block 41 in the opposite direction to the arms 42.
[0044] Each of the multiple HGAs 36 has a magnetic head 45 and a suspension 46. The magnetic head 45 may also be referred to as a slider. The magnetic head 45 records and reproduces information on the recording layer of the magnetic disk 31. In other words, the magnetic head 45 reads and writes information from and to the magnetic disk 31.
[0045] The suspension 46 includes, for example, a base plate, a load beam extending from the base plate, and a flexure attached to the base plate and the load beam. The flexure is a type of flexible printed circuit board (FPC).
[0046] The base plate is attached to the tip of the arm 42. The magnetic head 45 is mounted on the flexure. In this way, the magnetic head 45 is attached to the suspension 46. Furthermore, the suspension 46 is attached to the carriage 35.
[0047] The VCM 34 has a coil 51, a magnet 52, and a yoke 53. The coil 51 is held by a holder 43 of the carriage 35. The magnet 52 is, for example, a permanent magnet, and is attached to the base 15 via the yoke 53.
[0048] When the coil 51 is energized, the carriage 35 rotates around the support shaft 44 due to the electromagnetic force generated by the current in the coil 51 and the magnetic field of the magnet 52. In this way, the VCM 34 rotates the carriage 35 around the central axis Axh. As a result, the carriage 35 moves the magnetic head 45 around the central axis Axh via the suspension 46.
[0049] As shown in FIG. 3, the inner cover 16 has an inner surface 16a and an outer surface 16b. The inner surface 16a, together with the bottom surface 21a of the bottom wall 21 and the inner surface 22c of the side wall 22, forms (defines, partitions) the storage space S. The inner surface 16a faces substantially in the -Z direction as a whole. For example, the inner surface 16a faces the magnetic disk 31, the spindle motor 32, the HSA 33, and the VCM 34. The outer surface 16b is located on the opposite side of the inner surface 16a. The outer surface 16b faces substantially in the +Z direction as a whole.
[0050] 1, the inner cover 16 has a base portion 61, a peripheral portion 62, a central portion 63, and two mounting portions 64 and 65. Each of the base portion 61, the peripheral portion 62, the central portion 63, and the mounting portions 64 and 65 is part of the inner cover 16, and partially has an inner surface 16a and an outer surface 16b.
[0051] The thicknesses of the base 61, the peripheral edge portion 62, the central portion 63, and the attachment portions 64, 65 are generally constant. For example, the base 61, the peripheral edge portion 62, the central portion 63, and the attachment portions 64, 65 are formed by bending the inner cover 16 by press working. Note that the thicknesses of the base 61, the peripheral edge portion 62, the central portion 63, and the attachment portions 64, 65 may differ from one another.
[0052] The base portion 61 is surrounded by the peripheral portion 62 and also surrounds the central portion 63. In other words, the base portion 61 is provided between the peripheral portion 62 and the central portion 63. Note that the peripheral portion 62 and the central portion 63 may be adjacent to each other.
[0053] The peripheral portion 62 is formed in a substantially rectangular frame shape. As shown in Fig. 3, an inner surface 16a of the peripheral portion 62 is supported by a mounting surface 22b of the side wall 22 via a gasket 25. The peripheral portion 62 is attached to the side wall 22 with screws 26.
[0054] The peripheral edge 62 protrudes in approximately the -Z direction from the edge of the base 61 toward the mounting surface 22b. Therefore, the distance between the bottom surface 21a of the bottom wall 21 and the peripheral edge 62 is shorter than the distance between the bottom surface 21a and the base 61.
[0055] The central portion 63 is located approximately in the center of the inner cover 16. The central portion 63 protrudes from the base portion 61 toward the outer cover 17 in approximately the +Z direction. Therefore, the distance between the bottom surface 21a of the bottom wall 21 and the central portion 63 is longer than the distance between the bottom surface 21a and the base portion 61.
[0056] 1, the central portion 63 has, for example, a circular portion 67 and a sectorial portion 68. The circular portion 67 is a substantially annular portion provided around the central axis Axd. The sectorial portion 68 is a substantially sectorial portion centered near the central axis Axh.
[0057] 3, the circular portion 67 protrudes from the base 61 in the +Z direction, thereby defining a recess Rs recessed in the +Z direction from the inner surface 16a of the base 61. A portion of the spindle motor 32 is housed in the recess Rs. In other words, the circular portion 67 can expand the portion of the housing space S where the spindle motor 32 is disposed in the Z direction.
[0058] 4, the sector-shaped portion 68 protrudes from the base 61 in the +Z direction to form (define, define) a recess Rh recessed in the +Z direction from the inner surface 16a of the base 61. A portion of the HSA 33 is accommodated in the recess Rh. That is, the sector-shaped portion 68 can expand the portion of the accommodation space S where the HSA 33 is arranged in the Z direction.
[0059] 1, the outer surface 16b of the central portion 63 has a flat surface 63a, an end surface 63b, and a sloped surface 63c. The flat surface 63a is formed flat and faces approximately in the +Z direction. The end surface 63b and the sloped surface 63c extend between the edge of the flat surface 63a and the outer surface 16b of the base portion 61.
[0060] The end surface 63b extends from the edge of the flat surface 63a in approximately the -Z direction. On the other hand, the inclined surface 63c extends from the edge of the flat surface 63a at an angle with respect to the flat surface 63a. For example, the inclined surface 63c extends from the edge of the flat surface 63a so that the distance between the inclined surface 63c of the central portion 63 and the bottom surface 21a of the bottom wall 21 decreases toward the side wall 22.
[0061] The inclined surface 63c is connected to the end of the flat surface 63a of the sector portion 68 on the outer side in the radial direction perpendicular to the central axis Axh. Note that the inclined surface 63c is not limited to this example, and may be provided at another position or may be omitted.
[0062] The mounting portion 64 is provided between the base 61 and the circular portion 67 of the central portion 63. As shown in Fig. 3, the mounting portion 64 protrudes from the base 61 toward the bottom wall 21 in approximately the -Z direction. Therefore, the distance between the bottom surface 21a of the bottom wall 21 and the mounting portion 64 is shorter than the distance between the bottom surface 21a and the base 61.
[0063] 5 is an exemplary cross-sectional view showing a portion of the HDD 10 near the mounting portion 64 of this embodiment. As shown in FIG. 5, the mounting portion 64 protrudes from the base 61 in the −Z direction, thereby defining a recess Rd1 recessed in the −Z direction from the outer surface 16b of the base 61. The recess Rd1 is included in the gap G. The mounting portion 64 and the recess Rd1 extend around the central axis Axd and overlap the magnetic disk 31 in the Z direction along the central axis Axd.
[0064] The outer surface 16b of the mounting portion 64 has a bottom surface 64a and a side surface 64b. The bottom surface 64a and the side surface 64b define a recess Rd1. The bottom surface 64a is provided at the bottom of the recess Rd1 in the -Z direction. The bottom surface 64a is formed flat and faces approximately in the +Z direction. The side surface 64b extends approximately in the +Z direction from the edge of the bottom surface 64a and is connected to the outer surface 16b of the base 61, and is also connected to the flat surface 63a via the end surface 63b of the central portion 63. The side surface 64b and the end surface 63b of the central portion 63 are continuous with each other.
[0065] 1, the attachment portion 65 is provided between the peripheral edge portion 62 and the sector-shaped portion 68 of the central portion 63. The attachment portion 65 protrudes in approximately the -Z direction from the base portion 61 toward the bottom wall 21. Therefore, the distance between the bottom surface 21a of the bottom wall 21 and the attachment portion 65 is shorter than the distance between the bottom surface 21a and the base portion 61.
[0066] 6 is an exemplary cross-sectional view showing a portion of the HDD 10 near the mounting portion 65 of this embodiment. As shown in FIG. 6, the mounting portion 65 protrudes from the base 61 in the −Z direction, thereby defining a recess Rd2 recessed in the −Z direction from the outer surface 16b of the base 61. The recess Rd2 is included in the gap G. The mounting portion 65 and the recess Rd2 overlap with the VCM 34 in the direction along the central axis Axh.
[0067] The outer surface 16b of the mounting portion 65 has a bottom surface 65a and a side surface 65b. The bottom surface 65a and the side surface 65b define a recess Rd2. The bottom surface 65a is provided at the bottom of the recess Rd2 in the -Z direction. The bottom surface 65a is formed flat and faces approximately in the +Z direction. The side surface 65b extends approximately in the +Z direction from the edge of the bottom surface 65a and is connected to the outer surface 16b of the base 61 and is connected to the flat surface 63a via the end surface 63b of the central portion 63. The side surface 65b and the end surface 63b of the central portion 63 are continuous with each other.
[0068] As shown in FIGS. 5 and 6, the HDD 10 of this embodiment further includes two dampers 71 and 72 and a double-sided tape 73. The double-sided tape 73 is an example of a second adhesive material. The second adhesive material may be another adhesive material such as an adhesive. The dampers 71 and 72 are disposed in the gap G between the inner cover 16 and the outer cover 17. A portion of the damper 71 is disposed in the recess Rd1. A portion of the damper 72 is disposed in the recess Rd2.
[0069] As shown in FIG. 5, the damper 71 has a constrained layer 81 and a viscoelastic material (VEM) 82. However, the damper 71 is not limited to this example. The constrained layer 81 may also be called a vibration-damping plate. The viscoelastic material 82 is an example of a first adhesive material. However, the first adhesive material may be another adhesive material such as an adhesive.
[0070] The constrained layer 81 is made of, for example, a metal such as ferromagnetic stainless steel. For example, the constrained layer 81 is made of SUS 430. Note that the constrained layer 81 may be made of another ferromagnetic material or a non-magnetic material.
[0071] The constraining layer 81 is disposed in the gap G and is formed in a plate shape arranged along the XY plane. At least a portion of the constraining layer 81 is disposed in the recess Rd1. The constraining layer 81 has a bottom surface 81a, a flat surface 81b, an inclined surface 81c, and an end surface 81d. The bottom surface 81a is an example of a first surface. The inclined surface 81c is an example of a second surface.
[0072] The bottom surface 81a is formed flat and faces approximately in the -Z direction. The bottom surface 81a faces the bottom surface 64a of the mounting portion 64 of the inner cover 16. The bottom surface 81a and the bottom surface 64a are approximately parallel. Note that the bottom surface 81a may be inclined with respect to the bottom surface 64a.
[0073] The flat surface 81b and the inclined surface 81c are located on the opposite side of the bottom surface 81a and face the outer cover 17. The flat surface 81b is formed flat and faces substantially in the +Z direction. The inclined surface 81c is inclined with respect to the bottom surface 81a.
[0074] The end face 81d is provided at an end of the constraining layer 81 in the direction along the bottom face 81a. The end face 81d is approximately perpendicular to the bottom face 81a. The end face 81d is provided between the bottom face 81a and the flat surface 81b, and also between the bottom face 81a and the inclined face 81c. In other words, the end face 81d is connected to the inclined face 81c. Note that the end face 81d may be an edge between the bottom face 81a and the inclined face 81c.
[0075] The viscoelastic body 82 is disposed in the recess Rd1 of the gap G, and is interposed between the bottom surface 81a of the constraining layer 81 and the bottom surface 64a of the mounting portion 64 of the inner cover 16. In this way, the viscoelastic body 82 attaches the constraining layer 81 to the inner cover 16.
[0076] On a projection plane projected in the Z direction, the shapes of the constraining layer 81 and the viscoelastic body 82 are substantially equal to the shape of the recess Rd1. Therefore, the constraining layer 81 and the viscoelastic body 82 extend around the central axis Axd and overlap the magnetic disk 31 in the Z direction along the central axis Axd.
[0077] The flat surface 81b and the sloped surface 81c of the constraining layer 81 each extend around the central axis Axd. The sloped surface 81c is provided between the edge of the flat surface 81b on the radially outer side perpendicular to the central axis Axd and the end face 81d. Therefore, the sloped surface 81c is a substantially conical curved surface extending around the central axis Axd. However, the sloped surface 81c is not limited to this example.
[0078] The slope 81c is inclined with respect to the bottom surface 81a so that the distance between the bottom surface 81a and the slope 81c (the thickness of the constraining layer 81) decreases toward the outside in the radial direction perpendicular to the central axis Axd. In other words, the slope 81c is inclined with respect to the bottom surface 81a so that the distance between the bottom surface 81a and the slope 81c decreases toward the side wall 22. In yet another way, the slope 81c is inclined with respect to the bottom surface 81a so that the distance between the bottom surface 81a and the slope 81c decreases toward the end surface 81d.
[0079] The outer diameters of the attachment portion 64, the recessed portion Rd1, and the constraining layer 81 are smaller than the outer diameter of the magnetic disk 31. Therefore, the attachment portion 64 is spaced radially inward from the edge 31a of the magnetic disk 31 on the outer side in the radial direction perpendicular to the central axis Axd. For example, the base portion 61 or the peripheral portion 62 overlaps the edge 31a of the magnetic disk 31 in the direction along the central axis Axd. The outer diameter is the distance between the central axis Axd and the edge of the attachment portion 64, the recessed portion Rd1, and the constraining layer 81 on the outer side in the radial direction.
[0080] The end surface 81d of the constraining layer 81 and the side surface 64b of the mounting portion 64 face each other with a gap therebetween. The flat surface 63a of the central portion 63 and the flat surface 81b of the constraining layer 81 are arranged on approximately the same plane. In other words, the flat surface 63a of the central portion 63 and the flat surface 81b of the constraining layer 81 are arranged so as to be approximately continuous with each other.
[0081] In the Z direction along the central axis Axd, the end of the inclined surface 81c on the outer side in the radial direction perpendicular to the central axis Axd and the outer surface 16b of the base 61 are disposed at approximately the same position (height). Therefore, the outer surface 16b of the base 61 and the inclined surface 81c of the constraining layer 81 are disposed so as to be approximately continuous. In other words, the outer surface 16b and the inclined surface 81c are substantially connected to each other so that the angle between the outer surface 16b and the inclined surface 81c is an obtuse angle.
[0082] 1, the inclined surface 81c of the constraining layer 81 and the inclined surface 63c of the central portion 63 of the inner cover 16 are adjacent to each other around the central axis Axd. The angle between the outer surface 16b of the base portion 61 and the inclined surface 63c is approximately equal to the angle between the outer surface 16b of the base portion 61 and the inclined surface 81c. Note that the inclined surfaces 63c and 81c are not limited to this example.
[0083] 6, the damper 72 has a constraining layer 91 and a viscoelastic body 92. However, the damper 72 is not limited to this example. The viscoelastic body 92 is an example of a first adhesive material.
[0084] The constrained layer 91 is made of, for example, a ferromagnetic metal such as stainless steel. However, the constrained layer 91 may be made of another ferromagnetic material or a non-magnetic material. Furthermore, the material of the constrained layer 81 and the material of the constrained layer 91 may be different.
[0085] The constraining layer 91 is disposed in the gap G and is formed in a plate shape arranged along the XY plane. At least a portion of the constraining layer 91 is disposed in the recess Rd2. The constraining layer 91 has a bottom surface 91a, a flat surface 91b, an inclined surface 91c, and an end surface 91d. The bottom surface 91a is an example of a first surface. The inclined surface 91c is an example of a second surface.
[0086] The bottom surface 91a is formed flat and faces approximately in the -Z direction. The bottom surface 91a faces the bottom surface 65a of the mounting portion 65 of the inner cover 16. The bottom surface 91a and the bottom surface 65a are approximately parallel. The bottom surface 91a may be inclined with respect to the bottom surface 65a.
[0087] The flat surface 91b and the inclined surface 91c are located on the opposite side of the bottom surface 91a and face the outer cover 17. The flat surface 91b is formed flat and faces substantially in the +Z direction. The inclined surface 91c is inclined with respect to the bottom surface 91a.
[0088] The end surface 91d is provided at an end of the constraining layer 91 in the direction along the bottom surface 91a. The end surface 91d is approximately perpendicular to the bottom surface 91a. The end surface 91d is provided between the bottom surface 91a and the flat surface 91b, and also between the bottom surface 91a and the inclined surface 91c.
[0089] The viscoelastic body 92 is disposed in the recessed portion Rd2 of the gap G, and is interposed between the bottom surface 91a of the constraining layer 91 and the bottom surface 65a of the mounting portion 65 of the inner cover 16. In this way, the viscoelastic body 92 attaches the constraining layer 91 to the inner cover 16.
[0090] On a plane projected in the Z direction, the shapes of the constraining layer 91 and the viscoelastic body 92 are substantially the same as the shape of the recess Rd2. The constraining layer 91 and the viscoelastic body 92 overlap the VCM 34 in the Z direction along the central axis Axh.
[0091] The slope 91c is inclined with respect to the bottom surface 91a so that the distance between the bottom surface 91a and the slope 91c decreases toward the side wall 22. In other words, the slope 91c is inclined with respect to the bottom surface 91a so that the distance between the bottom surface 91a and the slope 91c decreases toward the end surface 91d.
[0092] The end surface 91d of the constraining layer 91 and the side surface 65b of the mounting portion 65 face each other with a gap therebetween. The flat surface 63a of the central portion 63 and the flat surface 91b of the constraining layer 91 are arranged on approximately the same plane. In other words, the flat surface 63a of the central portion 63 and the flat surface 91b of the constraining layer 91 are arranged so as to be approximately continuous with each other.
[0093] In the Z direction along the central axis Axh, the end of the inclined surface 91c connected to the end face 91d and the outer surface 16b of the peripheral portion 62 are disposed at approximately the same position (height). Therefore, the outer surface 16b of the peripheral portion 62 and the inclined surface 91c of the constraining layer 91 are disposed so as to be approximately continuous with each other. In other words, the outer surface 16b and the inclined surface 91c are substantially connected to each other so that the angle between the outer surface 16b and the inclined surface 91c is an obtuse angle.
[0094] The double-sided tape 73 attaches the outer cover 17 to the inner cover 16, the constraining layer 81, and the constraining layer 91. For example, the double-sided tape 73 adheres to the outer surface 16b of the inner cover 16, the flat surface 81b and the sloped surface 81c of the constraining layer 81, and the flat surface 91b and the sloped surface 91c of the constraining layer 91. In other words, the double-sided tape 73 bonds the outer cover 17 to the sloped surface 81c of the constraining layer 81, and also bonds the outer cover 17 to the sloped surface 91c of the constraining layer 91.
[0095] The outer cover 17 is thinner and less rigid than the inner cover 16. Therefore, by being attached to the inner cover 16, the constraining layer 81, and the constraining layer 91 with the double-sided tape 73, the outer cover 17 deforms along the outer surface 16b of the constraining layer 81, the flat surface 81b and the sloped surface 81c of the constraining layer 81, and the flat surface 91b and the sloped surface 91c of the constraining layer 91. The double-sided tape 73 sets the distance between the outer cover 17 and the inner cover 16, the constraining layer 81, and the constraining layer 91 to be approximately constant.
[0096] For example, the outer cover 17 has a peripheral portion 101, a central portion 102, and an inclined portion 103. The peripheral portion 101 surrounds the central portion 102 and the inclined portion 103. The inclined portion 103 is provided between the peripheral portion 101 and the central portion 102.
[0097] The peripheral edge portion 101 is adhered to the outer surfaces 16b of the base portion 61 and the peripheral edge portion 62 by double-sided tape 73. Therefore, the peripheral edge portion 101 is disposed along the outer surfaces 16b of the base portion 61 and the peripheral edge portion 62. Note that the peripheral edge portion 101 may be partially curved.
[0098] The central portion 102 is adhered to the flat surface 63a of the central portion 63, the flat surface 81b of the constraining layer 81, and the flat surface 91b of the constraining layer 91 by double-sided tape 73. Therefore, the central portion 102 is arranged along the flat surface 63a of the central portion 63, the flat surface 81b of the constraining layer 81, and the flat surface 91b of the constraining layer 91. Note that the central portion 102 may be partially curved.
[0099] The inclined portion 103 is adhered to the inclined surface 63c of the central portion 63, the inclined surface 81c of the constraining layer 81, and the inclined surface 91c of the constraining layer 91 by double-sided tape 73. Therefore, the inclined portion 103 is disposed along the inclined surface 63c of the central portion 63, the inclined surface 81c of the constraining layer 81, and the inclined surface 91c of the constraining layer 91, and is inclined with respect to the peripheral portion 101 and the central portion 102.
[0100] For example, external vibrations may be input to the HDD 10. In this case, the housing 11 vibrates, and the vibrations of the housing 11 are transmitted to the dampers 71 and 72. This causes the constraining layers 81 and 91 to vibrate relative to the housing 11. The viscoelastic body 82 deforms between the constraining layer 81 and the inner cover 16. The viscoelastic body 92 deforms between the constraining layer 91 and the inner cover 16. The viscoelastic bodies 82 and 92 convert the energy of the vibrations into heat, and the dampers 71 and 72 damp the vibrations of the housing 11.
[0101] The constraining layers 81 and 91 are attached to the outer cover 17 with double-sided tape 73. However, the outer cover 17 is thin and has lower rigidity than the constraining layers 81 and 91. Therefore, the outer cover 17 deforms in response to the vibration of the constraining layers 81 and 91. In other words, the constraining layers 81 and 91 can vibrate relative to the housing 11 even though they are attached to the outer cover 17.
[0102] The damper 71 damps vibrations input to the housing 11 in the vicinity of the magnetic disk 31. Therefore, the damper 71 can damp vibrations input to the magnetic disk 31 and vibrations input to the HSA 33 in the vicinity of the magnetic disk 31.
[0103] The damper 72 damps vibrations input to the housing 11 in the vicinity of the VCM 34. Therefore, the damper 72 can damp vibrations input to the HSA 33 in the vicinity of the VCM 34.
[0104] Since the dampers 71 and 72 damp the vibration of the HSA 33, the HDD 10 can accurately position the magnetic head 45 even if the recording density is high. In other words, the HDD 10 can improve the recording density.
[0105] The outer cover 17 is welded to the base 15, and the seal 29 seals the ventilation hole 28. As a result, the outer cover 17 and the seal 29 prevent the helium from leaking out of the storage space S and the gap G. However, a pressure difference may occur between the outside of the housing 11 and the storage space S and the gap G due to, for example, a change in air pressure.
[0106] In the gap G, for example, a void defined by the outer cover 17, the outer surface 16b of the inner cover 16, and the constraining layer 81 may be provided. In the gap G, for example, a void defined by the outer cover 17, the outer surface 16b of the inner cover 16, and the constraining layer 91 may be provided. The void is generated when the outer cover 17 is lifted (separated) from the inner cover 16 and the constraining layers 81, 91. For example, if the shape of the outer cover 17 is not aligned with the outer surface 16b of the inner cover 16, the flat surface 81b and the sloped surface 81c of the constraining layer 81, and the flat surface 91b and the sloped surface 91c of the constraining layer 91, the void will be large.
[0107] Helium is present in the gap, and if the helium in the gap expands due to a pressure difference, stress may be applied to the outer cover 17 near the gap and to the welded portion where the outer cover 17 and the base 15 are joined.
[0108] In this embodiment, the outer cover 17 is provided along the outer surface 16b of the inner cover 16, the flat surface 81b and the sloped surface 81c of the constraining layer 81, and the flat surface 91b and the sloped surface 91c of the constraining layer 91. Therefore, for example, the outer cover 17 is less likely to float (separate) from the inner cover 16 and the constraining layer 81. Furthermore, the outer cover 17 is less likely to float from the inner cover 16 and the constraining layer 91. Therefore, the generation of voids is suppressed or the voids are made smaller, and the helium in the voids has a small volume even if it expands, so it is less likely to apply stress to the outer cover 17.
[0109] In the HDD 10 according to the present embodiment described above, the housing 11 includes a base 15, an inner cover 16, and an outer cover 17. The base 15 defines a storage space S in which a magnetic disk 31 is disposed. The inner cover 16 is attached to the base 15 so as to close the storage space S. The outer cover 17 is attached to the base 15 so as to cover the inner cover 16. The constraining layers 81, 91 include bottom surfaces 81a, 91a and inclined surfaces 81c, 91c. The bottom surfaces 81a, 91a face the inner cover 16. The inclined surfaces 81c, 91c are located on the opposite side of the bottom surfaces 81a, 91a, face the outer cover 17, and are inclined relative to the bottom surfaces 81a, 91a. The viscoelastic bodies 82, 92 are interposed between the bottom surfaces 81a, 91a and the inner cover 16.
[0110] When vibrations occur in the HDD 10, the vibrations are input to the constraining layers 81, 91. When the constraining layers 81, 91 vibrate, the viscoelastic bodies 82, 92 deform between the inner cover 16 and the constraining layers 81, 91, converting the vibration energy into heat. As a result, the constraining layers 81, 91 and the viscoelastic bodies 82, 92 act as dampers 71, 72 to attenuate the vibrations of the HDD 10. If the constraining layers 81, 91 have a constant thickness, the constraining layers 81, 91 may be attached to the inner cover 16 so as to protrude substantially perpendicularly from the outer surface 16b of the inner cover 16. In other words, the end faces 81d, 91d of the constraining layers 81, 91 extend significantly from the outer surface 16b of the inner cover 16 in a substantially perpendicular direction. In this case, the outer cover 17 floats (is separated) from the corners between the end faces 81d, 91d of the constraining layers 81, 91 and the outer surface 16b of the inner cover 16, creating a gap surrounded by the end faces 81d, 91d of the constraining layers 81, 91, the outer surface 16b of the inner cover 16, and the outer cover 17. However, in this embodiment, the inclined surfaces 81c, 91c are inclined, thereby reducing the thickness of the constraining layers 81, 91. This makes it possible to arrange the inclined surfaces 81c, 91c and the outer surface 16b of the inner cover 16 so that they are substantially continuous, or to reduce the gap surrounded by the end faces 81d, 91d of the constraining layers 81, 91, the outer surface 16b of the inner cover 16, and the outer cover 17. Therefore, the HDD 10 of this embodiment can prevent the occurrence of a gap between the inner cover 16 and the outer cover 17, and can also prevent stress from being applied to the outer cover 17 due to expansion or contraction of gas in the gap.
[0111] An air vent 27 is provided in the inner cover 16. The air vent 27 connects the storage space S to a gap G between the inner cover 16 and the outer cover 17. An air vent 28 is provided in the outer cover 17. The air vent 28 connects the gap G to the outside and is sealed by a seal 29. The constraining layers 81 and 91 and the viscoelastic bodies 82 and 92 are disposed in the gap G. The storage space S and the gap G are filled with a gas other than air. Because the seal 29 seals the air vent 28, a pressure difference may occur between the outside air and the gas in the storage space S and the gap G. This pressure difference causes the gas in the gap to expand or contract. However, the HDD 10 of this embodiment can prevent the formation of such a gap, thereby preventing stress on the outer cover 17 due to the expansion or contraction of the gas in the gap.
[0112] The outer cover 17 is welded to the base 15. When the gas in the gap expands or contracts, stress is applied to the welded portion of the outer cover 17 and the base 15. However, the HDD 10 of this embodiment can prevent the formation of such a gap, and therefore can prevent stress from being applied to the welded portion of the outer cover 17 and the base 15 due to the expansion or contraction of the gas in the gap.
[0113] The magnetic disk 31 is configured to rotate around the central axis Axd. The constraining layer 81 extends around the central axis Axd. This allows the constraining layer 81 and the viscoelastic body 82 to more effectively damp vibrations generated by the HSA 33 and the rotating magnetic disk 31.
[0114] The slope 81c is inclined relative to the bottom surface 81a so that the distance between the bottom surface 81a and the slope 81c decreases radially outward in a direction perpendicular to the central axis Axd. That is, the slope 81c is a substantially conical curved surface. This makes it easy to install the outer cover 17 along the slope 81c in the HDD 10 of this embodiment, and prevents a gap from forming between the inner cover 16 and the outer cover 17.
[0115] The outer diameter of the constraining layer 81 is smaller than the outer diameter of the magnetic disk 31. A recess Rd1 that accommodates a viscoelastic body 82 may be provided in the inner cover 16. By forming the recess Rd1, the inner cover 16 moves closer to the magnetic disk 31. However, by matching the shape of the viscoelastic body 82 to the shape of the constraining layer 81, the outer diameter of the recess Rd1 can also be made smaller than the outer diameter of the magnetic disk 31. Therefore, the inner cover 16 can provide a distance between the inner cover 16 and the edge 31a of the magnetic disk 31, and can prevent interference with the edge 31a of the vibrating magnetic disk 31, for example.
[0116] The double-sided tape 73 bonds the outer cover 17 to the slopes 81c, 91c. The double-sided tape 73 pulls the outer cover 17 toward the slopes 81c, 91c, causing the outer cover 17 to deform along the slopes 81c, 91c. This makes it easy to install the outer cover 17 along the slopes 81c, 91c in the HDD 10 of this embodiment, and prevents gaps from forming between the inner cover 16 and the outer cover 17. Furthermore, by being interposed between the outer cover 17 and the slopes 81c, 91c, the double-sided tape 73 prevents gaps from forming between the outer cover 17 and the slopes 81c, 91c.
[0117] The HSA 33 has a magnetic head 45 and a carriage 35. The magnetic head 45 is configured to read and write information from and to the magnetic disk 31. The carriage 35 is configured to move the magnetic head 45 around a central axis Axh. The VCM 34 rotates the carriage 35 around the central axis Axh. The constraining layer 91 overlaps the VCM 34 in a direction along the central axis Axh. This allows the constraining layer 91 and the viscoelastic body 92 to more effectively damp vibrations caused by rotation of the HSA 33 by the VCM 34.
[0118] The base 15 has a bottom surface 21a and sidewalls 22. The bottom surface 21a faces the magnetic disk 31. The sidewalls 22 protrude from the bottom surface 21a and surround the magnetic disk 31. The slopes 81c, 91c are inclined relative to the bottom surfaces 81a, 91a so that the distance between the bottom surfaces 81a, 91a and the slopes 81c, 91c decreases toward the sidewalls 22. This makes it easier to prevent gaps from forming between the inner cover 16 and the outer cover 17 in the HDD 10 of this embodiment than when the thicknesses of the constraining layers 81, 91 decrease toward the center.
[0119] The constraining layers 81, 91 have end faces 81d, 91d provided at the ends of the constraining layers 81, 91 in the direction along the bottom faces 81a, 91a. The inclined faces 81c, 91c are inclined with respect to the bottom faces 81a, 91a so that the distance between the bottom faces 81a, 91a and the inclined faces 81c, 91c decreases toward the end faces 81d, 91d. In other words, there is no constant or increasing thickness of the constraining layers 81, 91 between the inclined faces 81c, 91c and the end faces 81d, 91d. This allows the constraining layers 81, 91 to be arranged so that the inclined faces 81c, 91c and the outer surface 16b of the inner cover 16 are substantially continuous, or reduces the gap surrounded by the end faces 81d, 91d of the constraining layers 81, 91, the outer surface 16b of the inner cover 16, and the outer cover 17. Therefore, the HDD 10 of this embodiment can suppress the occurrence of gaps between the inner cover 16 and the outer cover 17. Furthermore, the constraining layers 81, 91 are generally thin and therefore difficult to manufacture into complex shapes. The constraining layers 81, 91 of this embodiment can be formed more easily than when the thickness of the constraining layers 81, 91 is constant or increases between the slopes 81c, 91c and the end faces 81d, 91d.
[0120] Recesses Rd1 and Rd2 are provided in the inner cover 16. At least a portion of the constraining layers 81 and 91 and the viscoelastic bodies 82 and 92 are housed in the recesses Rd1 and Rd2. This allows the constraining layers 81 and 91 to be arranged so that the slopes 81c and 91c are substantially continuous with the outer surface 16b of the inner cover 16, or reduces the gap surrounded by the end faces 81d and 91d of the constraining layers 81 and 91, the outer surface 16b of the inner cover, and the outer cover 17. Therefore, the HDD 10 of this embodiment can suppress the generation of a gap between the inner cover 16 and the outer cover 17.
[0121] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]
[0122] 10...Hard disk drive (HDD), 11...Housing, 15...Base, 16...Inner cover, 17...Outer cover, 21a...Bottom, 22...Side wall, 27, 28...Ventilation hole, 29...Seal, 31...Magnetic disk, 33...Head stack assembly (HSA), 34...Voice coil motor (VCM), 35...Carriage, 45...Magnetic head, 73...Double-sided tape, 81, 91...Constraining layer, 81a, 91a...Bottom, 81c, 91c...Sloped surface, 81d, 91d...End surface, 82, 92...Viscoelastic body, S...Storage space, G...Gap, Axd, Axh...Central axis, Rd1, Rd2...Recess.
Claims
1. A magnetic disk, a housing having a base provided with a storage space in which the magnetic disk is placed, a first cover attached to the base so as to close the storage space, and a second cover attached to the base so as to cover the first cover; a constraining layer having a first surface facing the first cover and a second surface opposite the first surface facing the second cover and inclined relative to the first surface; a first adhesive material interposed between the first surface and the first cover; A disk device comprising:
2. Encapsulating materials, Further comprising: a first vent hole is provided in the first cover, the first vent hole communicating a gap between the first cover and the second cover with the accommodation space; a second vent hole that communicates the gap with the outside and is sealed by the sealing material is provided in the second cover; the constraining layer and the first adhesive material are disposed in the gap; The storage space and the gap are filled with a gas other than air.
2. The disk device according to claim 1.
3. the second cover is welded to the base; 2. The disk device according to claim 1.
4. the magnetic disk is configured to rotate about a first rotation axis; the constraining layer extends around the first rotation axis; 2. The disk device according to claim 1.
5. the second surface is inclined with respect to the first surface such that a distance between the first surface and the second surface decreases toward an outer side in a radial direction perpendicular to the first rotation axis; 5. The disk device according to claim 4.
6. the outer diameter of the constrained layer is smaller than the outer diameter of the magnetic disk; 5. The disk device according to claim 4.
7. a second adhesive material that bonds the second cover and the second surface; 2. The disk drive of claim 1, further comprising:
8. a head stack assembly including a magnetic head configured to read and write information from and to the magnetic disk, and a carriage configured to move the magnetic head about a second axis of rotation; a voice coil motor that rotates the carriage around the second rotation axis; Further comprising: the constrained layer overlaps the voice coil motor in a direction along the second rotation axis; 2. The disk device according to claim 1.
9. the base has a bottom surface facing the magnetic disk and a side wall protruding from the bottom surface and surrounding the magnetic disk; the second surface is inclined relative to the first surface such that the distance between the first surface and the second surface decreases toward the sidewall; 2. The disk device according to claim 1.
10. the constraining layer has an end surface provided at an end of the constraining layer in a direction along the first surface, the second surface is inclined relative to the first surface and connected to the end surface such that the distance between the first surface and the second surface decreases toward the end surface; 2. The disk device according to claim 1.
11. The first cover is provided with a recess, At least a portion of the constraining layer and the first adhesive material are accommodated in the recess.
2. The disk device according to claim 1.
Citation Information
Patent Citations
Disk drive employing a multi-layer noise-dampening HDA cover
US6529345B1