U.S. patent application number 16/183872 was filed with the patent office on 2019-03-14 for stepped assembly.
The applicant listed for this patent is SAINT-GOBAIN PERFORMANCE PLASTICS RENCOL LIMITED. Invention is credited to Simon A. HUGHES, Benjamin NIAS, Andrew R. SLAYNE, Robert WINTER.
Application Number | 20190080711 16/183872 |
Document ID | / |
Family ID | 54330805 |
Filed Date | 2019-03-14 |
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United States Patent
Application |
20190080711 |
Kind Code |
A1 |
NIAS; Benjamin ; et
al. |
March 14, 2019 |
STEPPED ASSEMBLY
Abstract
A tolerance ring can be disposed between an inner component and
an outer component, the inner and outer components defining stepped
sidewalls. In an embodiment, a preassembly can include an outer
component defining a bore having a stepped inner sidewall, an inner
component having a stepped outer sidewall, and a tolerance ring
adapted to be disposed between the inner component and the bore. In
an embodiment, an assembly can include an outer component defining
a bore having a stepped inner sidewall, an inner component having a
stepped outer sidewall, and a tolerance ring disposed between the
inner component and the bore. In an embodiment, a hard disk drive
preassembly can include an actuator arm defining a bore having a
stepped inner sidewall, a pivot having a stepped outer sidewall,
and a tolerance ring adapted to be disposed between the pivot and
the bore.
Inventors: |
NIAS; Benjamin; (Bristol,
GB) ; SLAYNE; Andrew R.; (Bristol, GB) ;
HUGHES; Simon A.; (Bristol, GB) ; WINTER; Robert;
(Longmont, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAINT-GOBAIN PERFORMANCE PLASTICS RENCOL LIMITED |
Coventry |
|
GB |
|
|
Family ID: |
54330805 |
Appl. No.: |
16/183872 |
Filed: |
November 8, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14796337 |
Jul 10, 2015 |
10157635 |
|
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16183872 |
|
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62023595 |
Jul 11, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16C 11/04 20130101;
F16C 17/18 20130101; F16D 1/0835 20130101; F16C 11/045 20130101;
F16D 7/021 20130101; G11B 5/4813 20130101 |
International
Class: |
G11B 5/48 20060101
G11B005/48; F16D 7/02 20060101 F16D007/02; F16C 11/04 20060101
F16C011/04; F16D 1/08 20060101 F16D001/08 |
Claims
1. A preassembly comprising: an outer component defining a bore; an
inner component; and a tolerance ring adapted to be disposed
between the inner component and the bore, the tolerance ring
including an annular sidewall and at least two circumferential rows
of radially extending projections, each row of radially extending
projections defining a maximum projecting distance as measured from
a central axis of the tolerance ring, wherein one of the inner and
outer components has a stepped sidewall with a greatest diameter at
a first axial end, and wherein each successive row of radially
extending projections, as measured from a first axial end of the
tolerance ring to a second axial end of the tolerance ring, has a
maximum projecting distance less than the previous row.
2. The preassembly according to claim 1, wherein the inner
component has a stepped outer sidewall.
3. The preassembly according to claim 2, wherein the radially
extending projections extend radially inward.
4. The preassembly according to claim 1, wherein the outer
component has a stepped sidewall.
5. The preassembly according to claim 4, wherein the radially
extending projections extend radially outward.
6. The preassembly according to claim 1, wherein the inner
component or pivot is rigid.
7. The preassembly according to claim 1, wherein the stepped outer
sidewall of the inner component or pivot is adapted to be
significantly undeformed during assembly.
8. The preassembly according to claim 1, wherein the outer
component or actuator arm is rigid.
9. The preassembly according to claim 1, wherein the stepped inner
sidewall of the outer component or actuator arm is adapted to be
significantly undeformed during assembly.
10. A hard disk drive preassembly comprising: an actuator arm
defining a bore having a stepped inner sidewall; a pivot having a
stepped outer sidewall; and a tolerance ring adapted to be disposed
between the pivot and the bore.
11. The hard disk drive preassembly according to claim 10, wherein
the tolerance ring further comprises a circumferential gap
extending at least partially between opposite axial ends of the
tolerance ring.
12. The hard disk drive preassembly according to claim 11, wherein
the circumferential gap extends entirely between opposite axial
ends of the tolerance ring.
13. The hard disk drive preassembly according to claim 10, wherein
the circumferential gap has a first width, W.sub.G1, as measured at
a first axial end of the tolerance ring and a second width,
W.sub.G2, as measured at a second axial end of the tolerance ring,
and wherein W.sub.G1 is different than W.sub.G2.
14. The hard disk drive preassembly according to claim 10, wherein
the tolerance ring comprises an annular sidewall having a plurality
of deformable radially extending projections.
15. The hard disk drive preassembly according to claim 10, wherein
the tolerance ring further comprises an undeformed band extending
around at least one axial end of the tolerance ring.
16. The hard disk drive preassembly according to claim 10, wherein
the stepped inner sidewall has a number of steps, wherein the
stepped outer sidewall has a number of steps, and wherein the
number of steps of the stepped inner sidewall is equal to the
number of steps of the outer sidewall.
17. The hard disk drive preassembly according to claim 10, wherein
a number of steps in the stepped sidewalls is equal to a number of
circumferentially extending rows of radially extending projections
in the tolerance ring.
18. The hard disk drive preassembly according to claim 10, wherein
the stepped inner sidewall has at least 2 steps.
19. The hard disk drive preassembly according to claim 18, wherein
each step of the inner sidewall defines a diameter, and wherein the
diameter of each step is different.
20. The hard disk drive preassembly according to claim 18, wherein
a diameter of adjacent steps increases from a first axial end of
the pivot or inner component to a second axial end of the pivot or
inner component.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a divisional and claims priority under
35 U.S.C. .sctn. 120 to U.S. patent application Ser. No. 14/796,337
entitled "STEPPED ASSEMBLY," by Benjamin NIAS et al., filed Jul.
10, 2015, which application claims priority under 35 U.S.C. .sctn.
119(e) to U.S. Provisional Application No. 62/023,595 entitled
"STEPPED ASSEMBLY," by Benjamin NIAS et al., filed Jul. 11, 2014,
of which all are assigned to the current assignee hereof and
incorporated herein by reference in their entireties.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to assemblies, and more
particularly to hard disk drive assemblies.
RELATED ART
[0003] Problems can occur during assembly of parts that use
tolerance rings, e.g., hard disk drives. For example, there may be
abrasion between the tolerance ring and various parts of the
apparatus, which removes small fragments from the surface of the
effected parts. These fragments are known in the art as particles.
In particular, radially outermost parts of the projections of the
tolerance ring may generate particles when sliding relative to
part(s) of the apparatus. In certain apparatus, such as in hard
disk drives where cleanliness is essential, production of particles
is undesirable, as the particles can adversely affect the function
of the apparatus.
[0004] Another problem associated with the use of tolerance rings
is known as "torque ripple" where the torque in the apparatus is
not generated at a continuous level, potentially causing axial
misalignment between the parts of the apparatus. Torque ripple can
be caused during assembly of the apparatus, e.g., by forces
exhibited during press fitting of the components. Particularly in
hard disk drives where high speed rotation is necessary, axial
misalignment may lead to particle generation or premature
failure.
[0005] There continues to exist a need for an assembly that can
minimize particle generation and torque ripple in apparatuses,
e.g., hard disk drives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments are illustrated by way of example and are not
limited in the accompanying figures.
[0007] FIG. 1 includes a cross-sectional side view of a preassembly
in accordance with an embodiment.
[0008] FIG. 2 includes a cross-sectional side view of an
alternative preassembly in accordance with an embodiment.
[0009] FIG. 3 includes a cross-sectional side view of an assembly
in accordance with an embodiment.
[0010] FIG. 4 includes a cross-sectional side view of a preassembly
in accordance with an embodiment.
[0011] FIG. 5 includes a partially cutout, exploded perspective
view of a hard disk drive in accordance with an embodiment.
[0012] Skilled artisans appreciate that elements in the figures are
illustrated for simplicity and clarity and have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements in the figures may be exaggerated relative to other
elements to help to improve understanding of embodiments of the
invention.
DETAILED DESCRIPTION
[0013] The following description in combination with the figures is
provided to assist in understanding the teachings disclosed herein.
The following discussion will focus on specific implementations and
embodiments of the teachings. This focus is provided to assist in
describing the teachings and should not be interpreted as a
limitation on the scope or applicability of the teachings. However,
other embodiments can be used based on the teachings as disclosed
in this application.
[0014] The terms "comprises," "comprising," "includes,"
"including," "has," "having" or any other variation thereof, are
intended to cover a non-exclusive inclusion. For example, a method,
article, or apparatus that comprises a list of features is not
necessarily limited only to those features but may include other
features not expressly listed or inherent to such method, article,
or apparatus. Further, unless expressly stated to the contrary,
"or" refers to an inclusive-or and not to an exclusive-or. For
example, a condition A or B is satisfied by any one of the
following: A is true (or present) and B is false (or not present),
A is false (or not present) and B is true (or present), and both A
and B are true (or present).
[0015] Also, the use of "a" or "an" is employed to describe
elements and components described herein. This is done merely for
convenience and to give a general sense of the scope of the
invention. This description should be read to include one, at least
one, or the singular as also including the plural, or vice versa,
unless it is clear that it is meant otherwise. For example, when a
single item is described herein, more than one item may be used in
place of a single item. Similarly, where more than one item is
described herein, a single item may be substituted for that more
than one item.
[0016] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. The
materials, methods, and examples are illustrative only and not
intended to be limiting. To the extent not described herein, many
details regarding specific materials and processing acts are
conventional and may be found in textbooks and other sources within
the tolerance ring and hard disk drive arts.
[0017] A preassembly in accordance with one or more of the
embodiments described herein can generally include an outer
component defining a bore having a stepped inner sidewall, an inner
component having a stepped outer sidewall, and a tolerance ring
adapted to be disposed between the inner component and the bore. In
particular embodiments, the stepped inner sidewall can have a
number of steps equal to a number of steps of the stepped outer
sidewall.
[0018] An assembly in accordance with one or more of the
embodiments described herein can include an outer component
defining a bore having a stepped inner sidewall, an inner component
having a stepped outer sidewall, and a tolerance ring disposed
between the inner component and the bore. In particular
embodiments, the stepped inner sidewall can have a number of steps
equal to the stepped outer sidewall.
[0019] Referring now to the figures, FIG. 1 illustrates a
preassembly 100 in accordance with one or more of the embodiments
described herein. The preassembly 100 can generally include an
outer component 102, an inner component 104, and a tolerance ring
106. The outer component 102 can define a bore 108 having a stepped
inner sidewall 110. The inner component can define a stepped outer
sidewall 112. The tolerance ring 106 can include an annular
sidewall 114 having a plurality of radially extending projections
116.
[0020] In a particular embodiment, at least one of the inner and
outer components 104 and 102 can be rigid. As used herein, "rigid"
refers to a resistance to perceptible deformation, e.g., a measured
dimension of a component will change by no greater than 10%, such
as no greater than 5%, or even no greater than 1% upon application
of a force of at least 10 N, such as at least 50 N, or even at
least 100 N. In such a manner, the inner or outer component 104 or
102 can be adapted to be significantly undeformed (e.g., deformed
by less than 10%, such as less than 5%, or even less than 1%)
during assembly. In a more particular embodiment, both the inner
and outer components 104 and 102 can be rigid. In an embodiment,
rigidity of one or both of the inner and outer components 104 and
102 can reduce particle generation and increase assembled
concentricity.
[0021] In a particular embodiment, the radially extending
projections 116 can be deformable in a radial direction. For
example, in a more particular embodiment, the radially extending
projections 116 can be adapted to operate in an elastic zone of
deformation. As such, the radially extending projections 116 can
deform upon a loading condition, e.g., a radial force, and can
return, or nearly return, to a pre-deformed state upon removal of
the loading condition. In another more particular embodiment, the
radially extending projections 116 can be adapted to operate in a
plastic zone of deformation. In such a manner, the radially
extending projections 116 can deform upon a loading condition,
however, unlike elastically deformable projections--such as
described above, the radially extending projections 116 may not
return to a pre-deformed state upon removal of the loading
condition.
[0022] In an embodiment, at least one of the radially extending
projections 116 can extend radially outward (e.g., away from a
central axis 118). In another embodiment, at least one of the
radially extending projections 116 can extend radially inward
(e.g., toward the central axis 118 as illustrated in FIG. 4). In a
more particular embodiment, all of the radially extending
projections 116 can extend in a same direction, e.g., radially
inward or radially outward.
[0023] In a particular embodiment, at least a portion of the
annular sidewall 114 can contact one of the inner and outer
components 104 and 102, while at least one of the plurality of
radially extending projections 116 contacts the other of the inner
and outer components 104 and 102. In a more particular embodiment,
all of the annular sidewall 114 can contact one of the inner and
outer components 104 and 102 and at least an outermost surface of
each radially extending projection 116 can contact the other of the
inner and outer components 104 and 102.
[0024] In an embodiment, the tolerance ring 106 can further include
an undeformed portion 126, e.g., an annular band, extending around
at least one axial end 120 or 122 of the tolerance ring 106. In a
more particular embodiment, each axial end 120 and 122 can include
an undeformed portion 126. The undeformed portion(s) 126 can be
devoid of radially extending projections 116. In an embodiment, the
undeformed portion(s) can fully contact one of the inner and outer
components 104 and 102. This may increase rotational and radial
stability of the preassembly 100 in assembled form (FIG. 3). In an
embodiment, the undeformed portion 126 may extend around the
tolerance ring 106 at both axial ends 120 and 122.
[0025] In a particular embodiment, the radially extending
projections 116 can be arranged in a number of circumferentially
extending rows. In a more particular embodiment, there can be at
least 2 circumferentially extending rows, such as at least 3
circumferentially extending rows, at least 4 circumferentially
extending rows, or even at least 5 circumferentially extending
rows. In yet a more particular embodiment, there can be no greater
than 15 circumferentially extending rows, such as no greater than
10 circumferentially extending rows, or even no greater than 5
circumferentially extending rows. As will be described in greater
detail, in a particular embodiment the number of circumferentially
extending rows can be equal to a number of steps in the stepped
inner sidewall 110, the stepped outer sidewall 112, or both.
[0026] Each circumferentially extending row can have a perceived
radial stiffness, as measured by the combined radial stiffness of
all radially extending projections 116 contained within the row. In
an embodiment, the perceived radial stiffness can be balanced,
e.g., the force provided by all of the radially extending
projections 116 can balance one another such that a net radial
force is zero. In another embodiment, the perceived radial
stiffness of multiple rows of projections can be equal.
[0027] In an embodiment, the tolerance ring 106 can further include
a circumferential gap (not illustrated) extending at least
partially between opposite axial ends 120 and 122 of the tolerance
ring 106. In a particular embodiment, the circumferential gap can
extend entirely between the axial ends 120 and 122 of the tolerance
ring 106.
[0028] In a particular embodiment, prior to installation of the
inner component, the outer component, and the tolerance ring 104,
102, and 106, the circumferential gap of the tolerance ring 106 can
have a uniform width, as measured in a circumferential direction
around the tolerance ring 106. After completion of assembly, the
circumferential gap can include a width, W.sub.G1, as measured in a
circumferential direction around the tolerance ring 106 at, or
adjacent, the axial end 122 of the tolerance ring 106, and a width,
W.sub.G2, as measured in a circumferential direction around the
tolerance ring 106 at, or adjacent, the axial end 120 of the
tolerance ring 106. In a particular embodiment, W.sub.G1 can be
different than W.sub.G2. For example, in a non-limiting embodiment,
W.sub.G1 can be no greater than 1.5 W.sub.G2, such as no greater
than 1.4 W.sub.G2, no greater than 1.3 W.sub.G2, no greater than
1.2 W.sub.G2, no greater than 1.1 W.sub.G2, no greater than 1.05
W.sub.G2, or even no greater than 1.01 W.sub.G2. In a further
embodiment, W.sub.G1 can be no less than 1.0001 W.sub.G2, such as
no less than 1.0002 W.sub.G2, no less than 1.001 W.sub.G2, or even
no less than 1.005 W.sub.G2.
[0029] In another embodiment, prior to installation of the inner
component 104, the outer component 102, and the tolerance ring 106,
the circumferential gap of the tolerance ring 106 can have a
nonuniform width, as measured in a circumferential direction around
the circumference of the tolerance ring 106. After completion of
assembly, the circumferential gap can have a uniform width, as
measured in a circumferential direction around the tolerance ring
106.
[0030] In an embodiment, the inner stepped sidewall 110 of the
outer component 102 and the outer stepped sidewall 112 of the inner
component 104 can each have a number of steps 124. In a particular
embodiment, each of the stepped sidewalls 110 and 112 can include
at least 2 steps, such as at least 3 steps (FIG. 2), at least 4
steps, or even at least 5 steps. In another embodiment, each of the
stepped sidewalls 110 and 112 can include no greater than 15 steps,
such as no greater than 10 steps, or even no greater than 5 steps.
In yet a more particular embodiment, the tolerance ring 106 can
have a number of circumferentially extending rows of radially
extending projections 116 that is equal to the number of steps
124.
[0031] In accordance with a particular embodiment, formation of
each step 124 can occur successively, e.g., from one axial end of
the stepped sidewall 110 or 112 to an opposite axial end of the
stepped sidewall 110 or 112. For example, a first step can be
formed by removing material to form a portion of the stepped
sidewall 110 or 112. The first step can have a first step diameter.
A second step adjacent to the first step can then be formed by
removing additional material to form a portion of the stepped
sidewall 110 or 112. The second step can have a second step
diameter that is different from the first step diameter. This
process can be repeated to form each additional step to form a
stepped sidewall 110 or 112.
[0032] In an embodiment, each step 124 can define a cylindrical
surface. When viewed in cross section, an inner surface of each
step 124 can extend along a line that is parallel, or generally
parallel, with the central axis 118. As used herein, "generally
parallel" refers to a relative angle between planes or lines of no
greater than 5.degree., such as no greater than 4.degree., no
greater than 3.degree., no greater than 2.degree., or even no
greater than 1.degree.. As used herein, "parallel" refers to a
relative angle between planes or lines of no greater than
0.1.degree.. In such a manner, the diameter of each step 124 can be
constant, or relatively constant, along an entire axial length of
the step 124.
[0033] In another embodiment, a diameter of at least one step can
change as measured along an axial length of the step. That is, the
step can have a non-uniform diameter. In a more particular
embodiment, at least one step can define a generally
frustocononical inner surface.
[0034] Referring still to FIG. 1, each step 124 can define a
diameter, or an average diameter, that is different from an
adjacent step 124. For example, the diameter of adjacent steps can
differ by at least 0.01 mm, such as at least 0.02 mm, at least 0.03
mm, at least 0.04 mm, at least 0.05 mm, at least 0.06 mm, at least
0.07 mm, at least 0.08 mm, or even at least 0.09 mm. In a
particular embodiment, the diameter of adjacent steps 124 can
differ by no greater than 10 mm, such as no greater than 5 mm, no
greater than 4 mm, no greater than 3 mm, no greater than 2 mm, no
greater than 1 mm, no greater than 0.75 mm, no greater than 0.5 mm,
no greater than 0.25 mm, or even no greater than 0.1 mm.
[0035] In another embodiment, the diameter of adjacent steps can
differ by at least 0.1%, such as at least 0.2%, at least 0.3%, at
least 0.4%, or even at least 0.5. Moreover, the diameter of
adjacent steps can differ by no greater than 10%, such as no
greater than 8%, no greater than 5%, or even no greater than
1%.
[0036] In an embodiment, a transition zone 128 disposed between
adjacent steps 124 can be smooth, or generally smooth. After
reading the entire specification, a skilled artisan will understand
that surface roughness, such as caused during the normal
manufacturing of the transition zone 128, constitutes "generally
smooth." As used herein, "smooth" refers to an enhanced surface
finish, for example, polished, buffed, etc. A smooth, or generally
smooth, transition zone 128 can help facilitate installation of the
tolerance ring 106.
[0037] A diameter of the transition zone 128 can change in a linear
or nonlinear manner. For example, in an embodiment, when viewed in
cross section, the transition zone 128 can extend between adjacent
steps 124 along a straight line. Alternatively, as illustrated in
FIG. 1, the transition zone 128 can have a partially, or fully,
arcuate profile. A curved, or partially curved, profile may reduce
particle generation during assembly. Moreover, a curved, or
partially curved, profile may more evenly radiate forces within the
transition zone 128 and prevent the formation of stress
concentration at or along a single location of the transition zone
128 where contact between the tolerance ring 106 and the transition
zone 128 occurs.
[0038] In a particular embodiment, each step can define an axial
length, L.sub.S, as measured between opposite axial ends of the
step 124 in a direction parallel with the central axis 118.
[0039] In an embodiment, the tolerance ring 106 can be installed at
least partially around the inner component 104 prior to insertion
of the inner component 104 into the outer component 102. In another
embodiment, the tolerance ring 106 can be installed at least
partially within the outer component 104 prior to insertion of the
inner component 104 into the outer component 102. As used herein,
"installed at least partially" refers to a condition where at least
1% of the tolerance ring 106, as measured in an axial direction, is
engaged with one of the inner or outer components 104 or 102 prior
to engagement with the other of the inner or outer components 104
or 102. In an embodiment, "installed at least partially" may refer
to a condition where at least 2%, at least 3%, at least 4%, at
least 5%, at least 10%, or even at least 25% of the tolerance ring
106, as measured in an axial direction, is engaged with one of the
inner or outer components 104 or 102 prior to engagement with the
other of the inner or outer components 104 or 102.
[0040] During assembly the inner and outer components 104 and 102
can be urged together along the central axis 118. After completion
of assembly, the tolerance ring 106 can be radially disposed
between the inner and outer components 104 and 102.
[0041] FIG. 3 illustrates an assembly 200 including the outer
component 102, the inner component 102, and a tolerance ring 106
disposed between the inner and outer components 104 and 102.
[0042] In the assembled state, the annular sidewall 114 of the
tolerance ring 106 can define a deformed, or bent, portion 130
disposed at a location between adjacent steps 124. More
particularly, the annular sidewall 114 can define a deformed, or
bent, portion 130 at a location adjacent to a transition zone 128
disposed between adjacent steps 124. A skilled artisan will
recognize that the deformed portion 130 of the tolerance ring
illustrated in FIG. 3 is exaggerated for clarity. Specifically,
because a difference between the diameters of adjacent steps 124 is
small (e.g., 0.1 mm), the sidewall 114 of the tolerance ring 106
may not significantly deform to the extent as illustrated.
[0043] In an embodiment, the inner component 104 can extend into
the outer component 102 a distance, D, as measured in a direction
parallel with the central axis 118. In a particular embodiment, the
distance, D, can extend between opposite axial ends of the outer
component 102. During installation of the inner component 104 into
the outer component 102, radial contact between the tolerance ring
106 and both of the inner and outer components 104 and 102 can
occur along an axial distance, D.sub.RC. As used herein "radial
contact" refers to contact between the tolerance ring 106 and both
the inner and outer components 104 and 102 which causes radial
compression of at least two radially extending projections 116 to a
final compressed state, e.g., a maximum compressed state. In an
embodiment, because the stepped sidewalls 110 and 112 define
progressively smaller diameters, e.g., the steps 124 each have a
progressively smaller diameter than a previous step 124, radial
contact may occur only after the inner component 104 axially
translates such that a lowermost edge of the inner component 104
comes into contact with an uppermost edge of the lowermost step
124. As used herein, "uppermost" and "lowermost" refer to the
orientation as illustrated in FIG. 3.
[0044] In an embodiment, D.sub.RC can be no greater than 0.95 D,
such as no greater than 0.9 D, no greater than 0.85 D, no greater
that 0.8 D, no greater than 0.75 D, no greater than 0.7 D, no
greater than 0.65 D, no greater than 0.6 D, or even no greater than
0.55 D. In another embodiment, D.sub.RC can be at least 0.05 D,
such as at least 0.1 D, at least 0.15 D, at least 0.2 D, at least
0.25 D, at least 0.3 D, at least 0.35 D, at least 0.4 D, at least
0.45 D, or even at least 0.5 D.
[0045] In an embodiment, the total work necessary to assemble the
inner component 104 into the outer component 106 can be less than
the work necessary to assemble a similar assembly having
non-stepped sidewalls. For example, formation of the assembly 200
can require performance of a work, W.sub.SS. Because radial contact
occurs along D.sub.RC--and D.sub.RC is less than D, and because
radial contact increases frictional and radial resistance, W.sub.SS
may be less than the work, W.sub.NSS, necessary to assembly a
similar assembly having a non-stepped sidewall. In such a manner,
the total assembly force can be reduced. In an embodiment, this may
reduce particle generation, reduce torque ripple and distortion,
reduce eccentric positioning of the inner component, and reduce
assembly time.
[0046] In a further embodiment, W.sub.SS can be less than 0.95
W.sub.NSS, such as less than 0.9 W.sub.NSS, less than 0.85
W.sub.NSS, less than 0.8 W.sub.NSS, less than 0.75 W.sub.NSS, less
than 0.7 W.sub.NSS, less than 0.65 W.sub.NSS, less than 0.6
W.sub.NSS, less than 0.55 W.sub.NSS, or even less than 0.5
W.sub.NSS.
[0047] FIG. 5 includes a partially cutout, exploded view of a hard
disk drive assembly 300. In an embodiment, the hard disk drive
assembly 300 can generally include an actuator arm 302 defining a
bore 304, a pivot 306, and a tolerance ring 308 disposed between
the pivot 306 and the bore 304. The bore 304 includes a stepped
inner sidewall 310. The pivot 306 has a stepped outer sidewall 312.
It can be appreciated that the stepped sidewalls 310 and 312 can
have at least 2 steps 314, such as at least 3 steps 314, at least 4
steps 314, or even at least 5 steps 314. In an embodiment, the
tolerance ring 308 can have an equal number of circumferential rows
of radially extending projections 316. Moreover, the bore, pivot,
and tolerance ring 304, 306, and 308 can have any number of
features as described above with respect to the inner component,
the outer component, and the tolerance ring 104, 102, and 106.
[0048] Many different aspects and embodiments are possible. Some of
those aspects and embodiments are described below. After reading
this specification, skilled artisans will appreciate that those
aspects and embodiments are illustrative and do not limit the scope
of the present invention. Embodiments may be in accordance with any
one or more of the items as listed below.
[0049] Item 1. A preassembly comprising:
[0050] an outer component defining a bore having a stepped inner
sidewall; an inner component having a stepped outer sidewall; and a
tolerance ring adapted to be disposed between the inner component
and the bore.
[0051] Item 2. An assembly comprising:
[0052] an outer component defining a bore having a stepped inner
sidewall; an inner component having a stepped outer sidewall; and a
tolerance ring disposed between the inner component and the
bore.
[0053] Item 3. The preassembly or assembly according to any one of
the preceding items, wherein the assembly comprises a hard disk
drive assembly.
[0054] Item 4. The preassembly or assembly according to any one of
the preceding items, wherein the outer component comprises an
actuator arm, and wherein the inner component comprises a
pivot.
[0055] Item 5. A hard disk drive preassembly comprising: [0056] an
actuator arm defining a bore having a stepped inner sidewall;
[0057] a pivot having a stepped outer sidewall; and [0058] a
tolerance ring adapted to be disposed between the pivot and the
bore.
[0059] Item 6. A method of assembling a hard disk drive comprising:
[0060] providing an actuator arm having a bore with a stepped inner
sidewall; [0061] providing a pivot having a stepped outer sidewall;
[0062] providing a tolerance ring; [0063] engaging a first radial
side of the tolerance ring with the sidewall of one of the bore and
pivot; [0064] engaging the other one of the bore and pivot with a
second radial side of the tolerance ring.
[0065] Item 7. The method according to item 6, wherein engaging the
first radial side of the tolerance ring is performed such that the
first radial side is engaged with the bore.
[0066] Item 8. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the tolerance ring further comprises a circumferential gap
extending at least partially between opposite axial ends of the
tolerance ring.
[0067] Item 9. The preassembly, hard disk drive preassembly,
assembly, or method according to item 8, wherein the
circumferential gap extends entirely between opposite axial ends of
the tolerance ring.
[0068] Item 10. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 8 and 9, wherein
the circumferential gap has a first width, W.sub.G1, as measured at
a first axial end of the tolerance ring and a second width,
W.sub.G2, as measured at a second axial end of the tolerance ring,
and wherein W.sub.G1 is different than W.sub.G2.
[0069] Item 11. The preassembly, hard disk drive preassembly,
assembly, or method according to item 10, wherein W.sub.G1 is no
greater than 1.5 W.sub.G2, such as no greater than 1.4 W.sub.G2, no
greater than 1.3 W.sub.G2, no greater than 1.2 W.sub.G2, no greater
than 1.1 W.sub.G2, no greater than 1.05 W.sub.G2, or even no
greater than 1.01 W.sub.G2.
[0070] Item 12. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 10 and 11,
wherein W.sub.G1 is at least 1.0001 W.sub.G2, such as at least
1.0002 W.sub.G2, at least 1.001 W.sub.G2, or even at least 1.005
W.sub.G2.
[0071] Item 13. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the tolerance ring comprises an annular sidewall having a
plurality of radially extending projections.
[0072] Item 14. The preassembly, hard disk drive preassembly,
assembly, or method according to item 13, wherein the radially
extending projections are deformable in a radial direction.
[0073] Item 15. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 13 and 14,
wherein the radially extending projections are adapted to operate
in an elastic zone of deformation.
[0074] Item 16. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 13-15, wherein at
least some of the radially extending projections extend radially
inward.
[0075] Item 17. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 13-15, wherein
all of the radially extending projections extend radially
inward.
[0076] Item 18. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 13-16, wherein at
least some of the radially extending projections extend radially
outward.
[0077] Item 19. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 13, 14, and 18,
wherein all of the radially extending projections extend radially
outward.
[0078] Item 20. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the tolerance ring further comprises an undeformed band
extending around at least one axial end of the tolerance ring.
[0079] Item 21. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the stepped inner sidewall has a number of steps, wherein
the stepped outer sidewall has a number of steps, and wherein the
number of steps of the stepped inner sidewall is equal to the
number of steps of the outer sidewall.
[0080] Item 22. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein a number of steps in the stepped sidewalls is equal to a
number of circumferentially extending rows of radially extending
projections in the tolerance ring.
[0081] Item 23. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 13-22, wherein
the radially extending projections form at least two
circumferentially extending rows along the annular band of the
tolerance ring.
[0082] Item 24. The method, hard disk drive, preassembly, or
assembly according to any one of items 13-23, wherein a perceived
radial stiffness of a first row of radially extending projections
is equal to a perceived radial stiffness of a second row of
radially extending projections.
[0083] Item 25. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the stepped inner sidewall has at least 2 steps, such as at
least 3 steps, at least 4 steps, at least 5 steps, or even at least
10 steps.
[0084] Item 26. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the stepped inner sidewall of the actuator arm has no
greater than 20 steps, such as no greater than 15 steps, or even no
greater than 11 steps.
[0085] Item 27. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein each step of the inner sidewall defines a diameter, and
wherein the diameter of each step is different.
[0086] Item 28. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of items 25-27, wherein a
diameter of adjacent steps increases from a first axial end of the
pivot or inner component to a second axial end of the pivot or
inner component.
[0087] Item 29. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein each step has a diameter, and wherein the diameter of
adjacent steps differs by no greater than 10%, such as no greater
than 8%, no greater than 5%, or even no greater than 1%.
[0088] Item 30. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein each step has a diameter, and wherein the diameter of
adjacent steps differs by no greater than 10 mm, such as no greater
than 1 mm, no greater than 0.5 mm, or even no greater than 0.2
mm.
[0089] Item 31. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein each step has a diameter, and wherein the diameter of
adjacent steps differs by at least 0.05 mm, such as at least 0.1
mm, or even at least 0.15 mm.
[0090] Item 32. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein each step of the stepped inner and outer sidewalls
comprises a cylindrical surface.
[0091] Item 33. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein, as viewed in cross section, at least two of the step are
oriented along parallel lines.
[0092] Item 34. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein, when viewed in cross section, all of the steps are
oriented along parallel lines.
[0093] Item 35. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the inner component or pivot is adapted to extend into the
outer component or bore a distance, D, wherein radial contact
between the tolerance ring and both the bore or outer component and
the pivot or inner component is adapted to occur along an axial
distance, D.sub.RC, and wherein D.sub.RC is less than D.
[0094] Item 36. The preassembly, hard disk drive preassembly,
assembly, or method according to item 35, wherein D.sub.RC is less
than 0.90 D, such as less than 0.75 D, or even less than 0.55
D.
[0095] Item 37. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein assembly of the hard disk drive, preassembly, or assembly
requires performance of a work, W.sub.SS, wherein assembly of a
hard disk drive, preassembly, or assembly having a non-stepped
sidewall requires performance of a work, W.sub.NSS, and wherein
W.sub.SS is less than 0.95 W.sub.NSS, such as less than 0.85
W.sub.NSS, less than 0.75 W.sub.NSS, less than 0.65 W.sub.NSS, or
even less than 0.5 W.sub.NSS.
[0096] Item 38. A preassembly comprising: [0097] an outer component
defining a bore; [0098] an inner component; and [0099] a tolerance
ring adapted to be disposed between the inner component and the
bore, the tolerance ring including an annular sidewall and at least
two circumferential rows of radially extending projections, each
row of radially extending projections defining a maximum projecting
distance as measured from a central axis of the tolerance ring,
[0100] wherein one of the inner and outer components has a stepped
sidewall with a greatest diameter at a first axial end, and wherein
each successive row of radially extending projections, as measured
from a first axial end of the tolerance ring to a second axial end
of the tolerance ring, has a maximum projecting distance less than
the previous row.
[0101] Item 39. The preassembly according to item 38, wherein the
inner component has a stepped outer sidewall.
[0102] Item 40. The preassembly according to item 39, wherein the
radially extending projections extend radially inward.
[0103] Item 41. The preassembly according to any one of items
38-40, wherein the outer component has a stepped sidewall.
[0104] Item 42. The preassembly according to item 41, wherein the
radially extending projections extend radially outward.
[0105] Item 43. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the inner component or pivot is rigid.
[0106] Item 44. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the stepped outer sidewall of the inner component or pivot
is adapted to be significantly undeformed during assembly.
[0107] Item 45. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the outer component or actuator arm is rigid.
[0108] Item 46. The preassembly, hard disk drive preassembly,
assembly, or method according to any one of the preceding items,
wherein the stepped inner sidewall of the outer component or
actuator arm is adapted to be significantly undeformed during
assembly.
[0109] Note that not all of the features described above are
required, that a portion of a specific feature may not be required,
and that one or more features may be provided in addition to those
described. Still further, the order in which features are described
is not necessarily the order in which the features are
installed.
[0110] Certain features are, for clarity, described herein in the
context of separate embodiments, may also be provided in
combination in a single embodiment. Conversely, various features
that are, for brevity, described in the context of a single
embodiment, may also be provided separately or in any
subcombinations.
[0111] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments, However,
the benefits, advantages, solutions to problems, and any feature(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential feature of any or all the claims.
[0112] The specification and illustrations of the embodiments
described herein are intended to provide a general understanding of
the structure of the various embodiments. The specification and
illustrations are not intended to serve as an exhaustive and
comprehensive description of all of the elements and features of
apparatus and systems that use the structures or methods described
herein. Separate embodiments may also be provided in combination in
a single embodiment, and conversely, various features that are, for
brevity, described in the context of a single embodiment, may also
be provided separately or in any subcombination. Further, reference
to values stated in ranges includes each and every value within
that range. Many other embodiments may be apparent to skilled
artisans only after reading this specification. Other embodiments
may be used and derived from the disclosure, such that a structural
substitution, logical substitution, or any change may be made
without departing from the scope of the disclosure. Accordingly,
the disclosure is to be regarded as illustrative rather than
restrictive.
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