U.S. patent application number 16/988107 was filed with the patent office on 2021-07-22 for suspension assembly with limiter and disk drive.
The applicant listed for this patent is Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation. Invention is credited to Yasutaka Sasaki, Yasuo Suzuki.
Application Number | 20210225394 16/988107 |
Document ID | / |
Family ID | 1000005038695 |
Filed Date | 2021-07-22 |
United States Patent
Application |
20210225394 |
Kind Code |
A1 |
Suzuki; Yasuo ; et
al. |
July 22, 2021 |
SUSPENSION ASSEMBLY WITH LIMITER AND DISK DRIVE
Abstract
According to one embodiment, a suspension assembly includes a
support plate including a distal end portion and a proximal end
portion, a wiring member including a gimbal portion and provided on
the support plate, and a magnetic head on the gimbal portion. The
gimbal portion includes a first welded portion located near the
proximal end portion and welded to the support plate, a second
welded portion located near the distal end portion and welded to
the support plate, a tongue portion between the first welded
portion and the second welded portion, supported displaceably to
the support plate, and on which the magnetic head is mounted, and a
limiter extending from the tongue portion toward the second welded
portion.
Inventors: |
Suzuki; Yasuo; (Fujisawa
Kanagawa, JP) ; Sasaki; Yasutaka; (Yokohama Kanagawa,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kabushiki Kaisha Toshiba
Toshiba Electronic Devices & Storage Corporation |
Tokyo
Tokyo |
|
JP
JP |
|
|
Family ID: |
1000005038695 |
Appl. No.: |
16/988107 |
Filed: |
August 7, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11B 21/22 20130101;
G11B 5/012 20130101; G11B 5/4833 20130101; G11B 5/483 20150901;
G11B 21/12 20130101; G11B 5/54 20130101 |
International
Class: |
G11B 5/48 20060101
G11B005/48; G11B 5/012 20060101 G11B005/012 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 17, 2020 |
JP |
2020-005792 |
Claims
1-5. (canceled)
6. A disk drive comprising: a disk-shaped recording medium includes
a recording layer; a suspension assembly comprising: a support
plate including a distal end portion and a proximal end portion; a
wiring member comprising a gimbal portion and provided on the
support plate; and a magnetic head mounted on the gimbal portion,
wherein the gimbal portion comprises a first welded portion located
near the proximal end portion of the support plate and welded to
the support plate, a second welded portion located near the distal
end portion of the support plate and welded to the support plate, a
tongue portion provided between the first welded portion and the
second welded portion and supported displaceably to the support
plate, and on which the magnetic head is mounted, and a limiter
extending from the tongue portion toward the second welded portion;
a tab provided at the distal end portion of the support plate; and
a ramp comprising a guide surface on which the tab is placeable and
a support surface against which the limiter is capable of
contact.
7. The disk drive of claim 6, wherein the gimbal portion comprises
a proximal end portion including the first welded portion and fixed
to the support plate, a pair of link portions with are resiliently
deformable, extend from the proximal end portion of the tongue
portion, and displaceably support the tongue portion, a connecting
frame which extends from one of the link portions to the other of
the link portions through a distal end portion side of the tongue
portion, and a pad portion between the connecting frame and the
tongue portion, connected to the connecting frame, the pad portion
including the second welded portion and being fixed to the support
plate.
8. The disk drive of claim 6, wherein the tongue portion comprises
two limiters extending from the tongue portion toward the second
welded portion, and the second welded portion is located between
the two limiters.
9. The disk drive of claim 6, further comprising an extendable
piezoelectric element mounted on the gimbal portion.
10. The disk drive of claim 7, wherein the tongue portion comprises
two limiters extending from the tongue portion toward the second
welded portion, and the second welded portion is located between
the two limiters.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2020-005792, filed
Jan. 17, 2020, the entire contents of which are incorporated herein
by reference.
FIELD
[0002] Embodiments described herein relate to a suspension assembly
and a disk drive including the suspension assembly.
BACKGROUND
[0003] As a disk drive, for example, a hard disk drive (HDD)
comprises a plurality of magnetic disks rotatably arranged in a
housing, a plurality of magnetic heads which reads/writes
information from/to the magnetic disks, and a head actuator
supporting the magnetic heads to be movable relative to the
magnetic disks.
[0004] The head actuator includes an actuator block that is
rotatably supported, and a plurality of head suspension assemblies
(may be referred to as head gimbal assemblies) which extend from
the actuator block and support the respective magnetic heads at the
distal end portions. Each of the head suspension assemblies
comprises a base plate whose one end is fixed to an arm, a load
beam that extends from the base plate, a tab that extends from a
distal end of the load beam, and a flexure (wiring member) provided
on the load beam and the base plate. The flexure includes a gimbal
portion that is displaceable, and the magnetic head is supported by
the gimbal portion.
[0005] In the disk drive as described above, the flexure includes
the gimbal portion that is displaceable, and therefore, when a
large external impact is applied to the disk drive, the gimbal
portion may be excessively deformed and the gimbal portion or the
magnetic head may be damaged.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a hard disk drive (HDD)
according to an embodiment with a top cover omitted.
[0007] FIG. 2 is a perspective view of an actuator assembly of the
HDD.
[0008] FIG. 3 is a perspective view of a head suspension assembly
of the actuator assembly.
[0009] FIG. 4 is an exploded perspective view of the head
suspension assembly.
[0010] FIG. 5 is a plan view of the head suspension assembly.
[0011] FIG. 6 is a perspective view of a ramp of the HDD.
[0012] FIG. 7A is a schematic side view of an engagement state
between a distal end portion of the head suspension assembly and
the ramp in a normal state.
[0013] FIG. 7B is a schematic side view of an engagement state
between the distal end portion of the head suspension assembly and
the ramp when an external force is applied.
DETAILED DESCRIPTION
[0014] Various embodiments will be described hereinafter with
reference to the accompanying drawings. In general, according to
one embodiment, a suspension assembly comprises: a support plate
including a distal end portion and a proximal end portion; a wiring
member comprising a gimbal portion and provided on the support
plate; and a magnetic head mounted on the gimbal portion. The
gimbal portion comprises a first welded portion located near the
proximal end portion of the support plate relative to the magnetic
head and welded to the support plate, a second welded portion
located near the distal end portion of the support plate relative
to the magnetic head and welded to the support plate, a tongue
portion provided between the first welded portion and the second
welded portion and supported displaceably to the support plate, and
on which the magnetic head is mounted, and a limiter extending from
the tongue portion toward the second welded portion.
[0015] Note that the disclosure is just exemplary, and thus
appropriate alterations to be conceived by those skilled in the art
without departing from the gist of the invention should be
rightfully included in the scope of the present invention. In
addition, for more clear description, the drawings may
schematically illustrate, for example, the width, thickness, or
shape of each part in comparison to the actual aspects. However,
the drawings are just exemplary and thus do not limit
interpretation to the present invention. In addition, in the
present specification and each figure, elements similar to those
described regarding already given figures are denoted with the same
reference signs, and the detailed descriptions thereof may be
appropriately omitted.
Embodiment
[0016] As a disk drive, a hard disk drive (HDD) according to an
embodiment will be described in detail.
[0017] FIG. 1 is a perspective view of the HDD according to an
embodiment, with a cover removed.
[0018] As illustrated, the HDD comprises a rectangular housing 10.
The housing 10 comprises a rectangular box-shaped base 12 with an
upper surface opened, and a top cover not shown. The base 12
includes a rectangular bottom wall 12a and side walls 12b standing
along the peripheral edges of the bottom wall and the base 12 is
integrally molded of, for example, aluminum. The top cover is
formed of, for example, stainless steel into a shape of a
rectangular plate shape and is fixed to the side walls 12b of the
base 12 with a plurality of screws.
[0019] In the housing 10, a plurality of magnetic disks 18 and a
spindle motor 19 are provided, the magnetic disks 18 serving as
disk-shaped recording media, the spindle motor 19 supporting and
rotating the magnetic disks 18. The spindle motor 19 is arranged on
the bottom wall 12a. Each of the magnetic disks 18 includes, for
example, a substrate that is formed into a disk shape with a
diameter of 95 mm (3.5 inches) and made of a nonmagnetic material,
such as glass, and a magnetic recording layer that is formed on an
upper surface (first surface) and a lower surface (second surface)
of the substrate. The magnetic disks 18 are coaxially fitted to a
hub, which is not illustrated, of the spindle motor 19 and further
clamped by a clamp spring 20. The magnetic disks 18 are supported
to be positioned parallel to the bottom wall 12a of the base 12.
The magnetic disks 18 are rotated at a predetermined rotation speed
by the spindle motor 19.
[0020] In the present embodiment, for example, four magnetic disks
18 are arranged in the housing 10, but the number of the magnetic
disks 18 is not limited to this and may be three or less, or five
or more.
[0021] In the housing 10 are provided a plurality of magnetic heads
17, which write and read information on and from the magnetic disks
18, and an actuator assembly 22, which supports the magnetic heads
17 such as to be movable with respect to the respective magnetic
disks 18. In the housing 10 are provided a voice coil motor (VCM)
24 which rotates and positions the actuator assembly 22, a ramped
loading mechanism 25 which holds the magnetic heads 17 at
respective unloading positions spaced away from the respective
magnetic disks 18 when the magnetic heads 32 are moved to the
outermost circumferences of the respective magnetic disks 18, and a
board unit (FPC unit) 21 on which electronic components such as
conversion connectors are mounted.
[0022] A printed circuit board (not shown) is fixed by screws to an
outer surface of the bottom wall 12a of the base 12. The printed
circuit board constitutes a control unit, which controls the
operation of the spindle motor 19 and also controls the respective
operations of the VCM 24 and the magnetic heads 17 via the board
unit 21.
[0023] FIG. 2 is a perspective view of the actuator assembly 22. As
illustrated, the actuator assembly 22 comprises an actuator block
29 with a through hole 26, a bearing unit (unit bearing) 28
provided in the through hole 26, a plurality of, for example, five
arms 32 extending from the actuator block 29, suspension assemblies
30 attached to the corresponding arms 32, and the magnetic heads 17
supported by the respective suspension assemblies 30. The actuator
block 29 is rotatably supported by the bearing unit 28 around a
support shaft (pivot) 31 stood on the bottom wall 12a.
[0024] In the present embodiment, the actuator block 29 and the
five arms 32 are integrally formed of aluminum or the like to
constitute a so-called E-block. Each of the arms 32 is formed into,
for example, an elongated flat plate shape and extends from the
actuator block 29 in a direction orthogonal to the support shaft
31. The five arms 32 are spaced in parallel with each other.
[0025] The actuator assembly 22 comprises a support frame 33 that
extends from the actuator block 29 in a direction opposite to the
arms 32. A voice coil 35 partially constituting the VCM 24 is
supported by the support frame 33. As illustrated in FIG. 1, the
voice coil 35 is positioned between a pair of yokes 37 provided in
the base 12. Together with the yokes 37 and a magnet fixed to the
either of the yokes 38, the voice coil 35 constitutes the VCM
24.
[0026] As illustrated in FIG. 2, the actuator assembly 22 comprises
eight suspension assemblies 30 that support the magnetic heads 17,
and these suspension assemblies 30 are attached to distal end
portions 32a of the respective arms 32. The suspension assemblies
30 include up head suspension assemblies supporting magnetic heads
17 upward and down head suspension assemblies supporting magnetic
heads 17 downward. The up head suspension assembly and the down
head suspension assembly are identical in structure but are
disposed mutually upside down.
[0027] In the present embodiment, in FIG. 2, a down head suspension
assembly 30 is mounted to an uppermost arm 32, and an up head
suspension assembly 30 is mounted to a lowermost arm 32. Up head
suspension assemblies 30 and down head suspension assemblies 30 are
mounted to three intermediate arms 32.
[0028] Next, an example of a suspension assembly 30 will be
described in detail.
[0029] FIG. 3 is a perspective view of the suspension assembly,
FIG. 4 is an exploded perspective view of the suspension assembly,
and FIG. 5 is a plan view of the suspension assembly.
[0030] As illustrated in FIGS. 3 and 4, each suspension assembly 30
includes a suspension 34 that extends from an arm 32, and a
magnetic head 17 is attached to a distal end portion of the
suspension 34. Note that the magnetic head 17 and the suspension
assembly 30 supporting the magnetic head 17 are collectively
referred to as a head suspension assembly.
[0031] The suspension 34 functioning as a support plate includes a
base plate 36 of rectangular shape that is made of a metal plate
having a thickness of several hundred micrometers and a load beam
38 of leaf spring shape that is made of a metal plate having a
thickness of several ten micrometers. The load beam 38 has a distal
end portion that constitutes a distal end portion of the support
plate, and a proximal end portion of the load beam 38 and the base
plate 36 constitute a proximal end portion of the support plate.
The proximal end portion of the load beam 38 is arranged to overlay
on a distal end portion of the base plate 36 and is fixed to the
base plate 36 by being welded at a plurality of positions. The
proximal end portion of the load beam 38 has a width which is
substantially equal to the width of the base plate 36. A tab 40 of
rod shape is protrudingly provided at the distal end of the load
beam 38.
[0032] The base plate 36 has a proximal end portion that includes a
circular opening 36a and an annular projection 36b located around
the opening 36a. The base plate 36 is fastened to the distal end
portion 32a of the arm 32 by fitting the projection 36b to a
circular swage hole, not illustrated, that is formed in a swaged
seat surface of the arm 32 and swaging the projection 36b. The
proximal end of the base plate 36 may be fixed to the distal end
portion 32a of the arm 32 by laser welding, spot welding, or
adhesion.
[0033] The suspension assembly 30 comprises a flexure (wiring
member) 42 of elongated strip shape, configured to transmit a
recording/reading signal and a drive signal for a piezoelectric
element, and a pair of piezoelectric elements (e.g., PZT elements)
50 mounted on the flexure 42. As illustrated in FIGS. 2 and 3, the
flexure 42 includes a distal end side portion 42a that is arranged
on the load beam 38 and the base plate 36, a proximal end side
portion 42b that extends outward from a side edge of the base plate
36 and extends to the actuator block 29 along a side edge of the
arm 32, and a connection end portion 42c that extends from an
extending end of the proximal end side portion 42b. The connection
end portion 42c includes a plurality of connection pads 43 arranged
side by side. These connection pads 43 are electrically joined to
connection terminals of a wiring board 51 installed in the actuator
block 29.
[0034] As illustrated in FIGS. 3, 4, and 5, a distal end portion of
the flexure 42 is provided on the distal end portion of the load
beam 38 and constitutes a gimbal portion 44 that functions as a
resilient support portion. The magnetic head 17 is placed and fixed
on the gimbal portion 44 and supported by the load beam 38 via the
gimbal portion 44. The pair of piezoelectric elements 50 as drive
elements are mounted on the gimbal portion 44 and arranged on both
sides of the magnetic head 17 in the width direction of the
magnetic head 15.
[0035] The flexure 42 comprises a thin metal plate (metal plate)
46, such as stainless steel, that serves as a base, and a laminated
member (FPC) 48 of stripped shape that is pasted or fixed on the
thin metal plate 46, and the flexure 42 is formed into an elongated
laminated plate. The laminated member 48 includes a base insulating
layer (first insulating layer) that is mostly fixed to the thin
metal plate 46, a conductive layer (wiring pattern) formed on the
base insulating layer and constituting a plurality of signal wiring
lines and drive wiring lines, and a plurality of connection pads
(electrode pads), and a cover insulating layer (second insulating
layer) formed on the base insulating layer so as to cover the
conductive layer. As the conductive layer, for example, copper foil
can be used. In the distal end side portion 42a of the flexure 42,
the thin metal plate 46 is pasted on the surfaces of the load beam
38 and the base plate 36 or spot-welded thereto at a plurality of
welded points. In an example, the thin metal plate 46 includes two
welded points (first welded portions) B1 where the thin metal plate
46 is welded to the proximal end portion of the load beam 38 and
one welded point (second welded portion) B2 where the thin metal
plate 46 is welded to the distal end portion of the load beam 38.
In other words, the thin metal plate 46 is welded to the load beam
38 at least at two positions, that is, the welded points B1 located
on a leading end side of the head 17 and the welded point B2
located on a trailing end side of the head 17.
[0036] In the gimbal portion 44, the thin metal plate 46 integrally
includes a tongue portion (support portion) 44a of substantially
rectangular shape, a proximal end portion (proximal end plate
portion) 44b of substantially rectangular shape, a pair of
outriggers (link portions) 44c of elongated shape, a connecting
frame 44d, and a fixing pad portion 44e of substantially
rectangular shape, the tongue portion 44a being located on a distal
end side, the proximal end portion 44b being located on a proximal
end side, spaced apart from the tongue portion 44a, the pair of
outriggers 44c extending from the tongue portion 44a to the
proximal end portion 44b and displaceably supporting the tongue
portion 44a, the connecting frame 44d extending around a distal end
side of the tongue portion 44a, from one outrigger 44c to the other
outrigger 44c, and the fixing pad portion 44e extending from the
connecting frame 44d and facing a distal end portion of the tongue
portion 44a. Furthermore, the thin metal plate 46 integrally
includes a pair of limiters (ramp limiters) 45 of rectangular shape
that extend from the tongue portion 44a and protrude distally from
the load beam 38. The limiters 45 are located on both sides of the
fixing pad portion 44e. Instead of the pair of limiters 45, one or
three or more of limiters 45 may be employed. Furthermore, each of
the limiters 45 is not limited to the rectangular shape but can
have any shape.
[0037] The proximal end portion 44b is pasted on the surface of the
load beam 38 and spot-welded to the load beam 38 at the welded
points B1. The fixing pad portion 44e is spot-welded to the distal
end portion of the load beam 38 at the welded point B2. The tongue
portion 44a is formed in a size and shape large enough to mount the
magnetic head 17, for example, in a substantially rectangular
shape. The tongue portion 44a is arranged so that a central axis in
a width direction thereof coincides with a central axis C1 of the
suspension 34. Substantially the center portion of the tongue
portion 44a is in contact with a dimple (protruding portion) 52
provided at the distal end portion of the load beam 38. The tongue
portion 44a is displaceable in various directions about the dimple
52 in response to resilient deformation of the pair of outriggers
44c and connecting frame 44d. Thus, the tongue portion 44a and the
magnetic head 17 can flexibly follow a surface deformation of the
magnetic disk 18, in a roll direction and a pitch direction,
maintaining a minute gap between the surface of the magnetic disk
18 and the magnetic head 17.
[0038] In the gimbal portion 44, the laminated member 48 of the
flexure 42 is partially bifurcated and is located on both sides of
the central axis C1 of the suspension 34. The laminated member 48
includes a proximal end portion 48a that is fixed to the proximal
end portion 44b of the thin metal plate 46, a distal end portion
48b that is pasted to the tongue portion 44a, and a pair of bridge
portions 48c of strip shape that extends from the proximal end
portion 48a to the distal end portion 48b. The bridge portions 48c
are arranged so as to partially overlap the tongue portion 44a
except for the center portion of the tongue portion 44a and is
pasted to the tongue portion 44a.
[0039] The magnetic head 17 overlaps the bridge portions 48c to be
fixed to the tongue portion 44a with an adhesive. The magnetic head
17 is arranged so that a longitudinal central axis thereof
coincides with the central axis C1 of the suspension 34, and the
magnetic head 17 has a substantially the center portion that is
located on the dimple 52. In the magnetic head 17, a recording
element and a reading element are electrically connected to a
plurality of electrode pads 54 in the distal end portion 48b by a
conductive adhesive, such as solder or silver paste. Therefore, the
magnetic head 17 is connected to the signal wiring lines of the
laminated member 48 via the electrode pads 54.
[0040] The pair of piezoelectric elements 50 uses, for example, a
piezoelectric thin film (PZT element) of rectangular plate shape.
The piezoelectric element 50 is not limited to the piezoelectric
thin film (thickness of approximately 10 .mu.m), but a bulk
piezoelectric element or bulk laminated piezoelectric element
(thickness of 50 .mu.m or more) may be used. The piezoelectric
element 50 is not limited to the PZT element, but another
piezoelectric element may be used. Furthermore, each of the drive
elements is not limited to the piezoelectric element, but another
drive element that is extendable and contractable by applying
current may be used.
[0041] The piezoelectric elements 50 are each arranged such that a
longitudinal direction (extending and contracting direction)
thereof is parallel to the central axis C1 of the load beam 38. The
two piezoelectric elements 50 are arranged on both sides of the
magnetic head 17 in a width direction and are arranged side by side
in parallel with each other. Each of the piezoelectric elements 50
has one longitudinal end which is mounted on the distal end portion
48b and electrically connected to an electrode pad in the distal
end portion 48b. Each piezoelectric element 50 has the other
longitudinal end which is mounted on an intermediate portion of
each bridge portion 48c and electrically connected to an electrode
pad in the bridge portion 48c. Therefore, the piezoelectric
elements 50 are connected to the drive wiring lines of the
laminated member 48 via the electrode pads.
[0042] As illustrated in FIGS. 1 and 2, the board unit 21
integrally includes a base portion 58 of substantially rectangular
shape, a relay portion 57 of elongated strip shape that extends
from the base portion 58, and the wiring board 51 that is
continuous with a distal end of the relay portion 57. The base
portion 58, the relay portion 57, and the wiring board 51 are
formed using a flexible printed wiring board (FPC). The base
portion 58 is arranged on the bottom wall 12a of the base 12, and
the wiring board 51 is mounted to an installation surface of the
actuator block 29.
[0043] Electronic components, such as a conversion connector and a
plurality of capacitors, which are not illustrated, are mounted on
the base portion 58. The wiring board 51 is provided with a large
number of connection pads, not illustrated. The connection end
portions 42c of the flexures 42 of the suspension assemblies 30
described above are arranged to overlap the connection pads, being
joined to the connection pads by, for example, soldering.
Furthermore, for example, a head IC (head amplifier) 53 is mounted
on the wiring board 51 and connected to the connection pads and the
base portion 58 via a plurality of wiring lines, which are not
illustrated. Thus, eight magnetic heads 17 of the actuator assembly
22 are electrically connected to the base portion 58 through the
wiring lines of the flexure 42 and via the connection end portions
42c, the wiring board 51, the head IC 53, and the relay portion
57.
[0044] In a state where the actuator assembly 22 configured as
described above is incorporated on the base 12, the support shaft
31 is stood substantially parallel to a spindle of the spindle
motor 19. Each magnetic disk 18 is located between two suspension
assemblies 30. During operation of the HDD, the magnetic heads 17
supported by the two suspension assemblies 30 face the upper and
lower surfaces of the magnetic disk 18.
[0045] As illustrated in FIG. 1, when the HDD is not operating, the
actuator assembly 22 is rotated to the unload position where each
of the magnetic heads 17 is located outside the outermost
circumference of each magnetic disk 18 and the actuator assembly 22
is held at the unload position by the ramp load mechanism 25.
[0046] Next, a ramp of the ramp load mechanism 25 and a positional
relationship between the ramp and the suspension assembly will be
described in detail.
[0047] FIG. 6 is a perspective view of the ramp of the ramp load
mechanism. As illustrated in FIGS. 1 and 6, the ramp load mechanism
25 comprises the ramp 60 installed on the base 12 and the tabs 40
engageable with the ramp 60. As described above, each of the tabs
40 is provided at the distal end of the load beam 38 of each
suspension assembly 30.
[0048] The ramp 60 is fixed to the bottom wall 12a of the base 12
and is located in the vicinities of the peripheral edges of the
magnetic disks 18. The ramp 60 includes a ramp body 62 formed in a
block shape and eight guide surfaces (guide portions) 64 formed on
one side portion of the ramp body 62. The guide surfaces 64 are
configured to support and guide the tabs 40 of the eight suspension
assemblies 30. These guide surfaces 64 are arranged at
predetermined intervals in the axial direction of the magnetic
disks 18 and are arranged in accordance with the heights of the
corresponding suspension assemblies 30. Each of the guide surfaces
64 extends substantially in a radial direction of each magnetic
disk 18 to the vicinity of the outer peripheral edge of the
magnetic disk 18 and is arranged on a movement path of each tab 40.
Each guide surface 64 includes a first inclined surface 64a that is
inclined toward a magnetic disk 18 to load and unload a magnetic
head 17 on the magnetic disk, a flat surface 64b which is
continuous from the first inclined surface 64a and extends parallel
to the surface of the magnetic disk, and a second inclined surface
64c which is inclined and extend from the other end of the flat
surface 64b to a terminal end of the guide surface.
[0049] The ramp 60 has four support blocks 70 protruding from one
side of the ramp body 62. Each of the support blocks 70 has an
elongated rectangular parallelepiped shape and is provided between
two adjacent guide surfaces 64. The support blocks 70 each have an
upper surface and a lower surface that extend substantially
parallel to the bottom wall 12a and form support surfaces 70a. Each
of the support surfaces 70a is located at a height, apart from a
corresponding guide surface 64 in the axial direction.
[0050] A plurality of rectangular recesses is formed at an end of
the ramp body 62 near the magnetic disks 18. Each recess is located
between two vertically adjacent guide surfaces 64. In a state where
the ramp 60 is installed on the base 12, the outer peripheral edges
of the four magnetic disks 18 are spatially located in the
corresponding recesses.
[0051] According to the HDD configured as described above, the VCM
24 turns the actuator assembly 22 around the support shaft 31, and
thereby the magnetic heads 17 are moved to desired seek positions
while facing the surfaces of the magnetic disks 18. When the
magnetic heads 17 move out of the outer peripheries of the magnetic
disks 18 and move to predetermined stop positions during
non-operation of the HDD, the tabs 40 of the suspension assemblies
30 ride on the corresponding guide surfaces 64 of the ramp 60.
Thus, the magnetic heads 17 are held by the ramp 60 at unload
positions that are separated from the magnetic disks 18.
[0052] FIGS. 7A and 7B are schematic views of positional
relationships between the ramp 60 and a suspension assembly 30 at
the unload position. As illustrated in FIG. 7A, in a normal state,
when a magnetic head 17 moves out of the outer periphery of a
magnetic disk 18 to a predetermined stop position, a tab 40 of the
suspension assembly 30 rides on the guide surface 64 of the ramp 60
and is held on the guide surface 64. Thus, the magnetic heads 17
are held by the ramp 60 at unload positions that are separated from
the magnetic disks 18. Furthermore, the limiters 45 of the
suspension assembly 30 face a support surface 70a of the ramp 60,
spaced apart therefrom.
[0053] As illustrated in FIG. 7B, in a state where the magnetic
head 17 is held at the unload position, when a large impact is
applied to the HDD, displacing a tongue portion 44a and the
magnetic head 17 in a direction away from a dimple 52, a pair of
the limiters 45 are brought into contact against the support
surface 70a of the ramp 60 and stops the displacement of the tongue
portion 44a and the magnetic head 17. In other words, the limiters
45 prevent excessive displacement and deformation of the magnetic
head 17 and the tongue portion 44a.
[0054] In the HDD according to the present embodiment configured as
described above, a gimbal portion 44 of each suspension assembly is
welded to a support plate at least at two positions of the welded
points B1 located on the leading end side of the head 17 and the
welded point B2 located on the trailing end side thereof, and the
gimbal portion 44 includes the tongue portion 44a that is
resiliently deformably provided between these welded points B1 and
B2, and the limiters 45 provided at the tongue portion 44a. The
limiters 45 are formed and arranged so as to make contact against a
support surface 70a of the ramp 60. When an impact is applied to
the HDD, the limiters 45 are brought into contact against the
support surface 70a of the ramp 60 to prevent excessive
displacement and deformation of the tongue portion 44a and the
magnetic head 17.
[0055] From the above description, according to the present
embodiment, it is possible to obtain a suspension assembly and a
disk drive that prevent excessive deformation and damage and have
improved reliability.
[0056] 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.
[0057] For example, the shape of the thin metal plate that
constitutes the gimbal portion is not limited to the
above-described embodiments but may have any shape that deformably
supports the tongue portion. The limiters 45 may have a
configuration in which a separate limiter is mounted to the tongue
portion.
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