U.S. patent application number 17/126680 was filed with the patent office on 2022-06-23 for hydraulic bushing with internal snubber.
The applicant listed for this patent is The Pullman Company. Invention is credited to Zoren E. GASPAR, Scott W. RAWLINGS.
Application Number | 20220196107 17/126680 |
Document ID | / |
Family ID | 1000005327413 |
Filed Date | 2022-06-23 |
United States Patent
Application |
20220196107 |
Kind Code |
A1 |
GASPAR; Zoren E. ; et
al. |
June 23, 2022 |
Hydraulic Bushing with Internal Snubber
Abstract
A hydraulic bushing assembly comprises an inner tube, a travel
limiter surrounding the inner tube, a first intermediate insert, a
second intermediate insert spaced apart from the first intermediate
insert, and an elastomeric bushing disposed around the inner tube
and encapsulating the first intermediate insert and the second
intermediate insert. The elastomeric bushing at least partially
encapsulates the travel limiter such that a portion of the
elastomeric bushing is positioned between the travel limiter and
the inner tube. First and second snubbers limit displacement of the
travel limiter and define first and second fluid chamber within the
elastomeric bushing. A fluid passageway defined by the elastomeric
bushing and an outer tube extends between the first and second
fluid chambers, wherein relative movement between the inner tube
and the outer tube causes fluid transfer between the first fluid
chamber and the second fluid chamber.
Inventors: |
GASPAR; Zoren E.; (Huron,
OH) ; RAWLINGS; Scott W.; (North Ridgeville,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Pullman Company |
Milan |
OH |
US |
|
|
Family ID: |
1000005327413 |
Appl. No.: |
17/126680 |
Filed: |
December 18, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16F 13/14 20130101 |
International
Class: |
F16F 13/14 20060101
F16F013/14 |
Claims
1. A hydraulic bushing assembly comprising: an inner tube including
an outer surface; an outer tube circumscribing the inner tube; a
travel limiter fixed to the inner tube; an elastomeric bushing
bonded to an outer surface of the travel limiter; a snubber
assembly positioned within the outer tube and spaced apart from the
travel limiter when the bushing is in an unloaded state, wherein
the travel limiter is operable to move into contact with the
snubber assembly when the bushing is in a loaded state, the snubber
assembly including an outer snubber and a spaced apart inner
snubber interconnected with an elastomeric cushion, the outer
snubber including a frame surrounding a window, the frame being in
contact with the outer tube, the cushion extending through the
window, wherein the inner snubber is aligned with the window; first
and second fluid chambers; and a fluid passageway defined by the
elastomeric bushing and the outer tube, the fluid passageway
extending between the first and second fluid chambers, wherein
movement of the inner tube relative to the outer tube causes fluid
transfer between the first fluid chamber and the second fluid
chamber.
2. The hydraulic bushing assembly according to claim 1, wherein the
travel limiter includes a protrusion with a distal surface.
3. The hydraulic bushing assembly according to claim 2, wherein the
snubber includes a stop face selectively engageable with the travel
limiter distal surface.
4. The hydraulic bushing assembly according to claim 3, wherein the
stop face and the travel limiter distal surface are spherically
shaped.
5. The hydraulic bushing assembly according to claim 2, wherein the
inner tube extends along a longitudinal axis and the protrusion
radially extends within one of the fluid chambers.
6. The hydraulic bushing assembly according to claim 3, wherein the
stop face is positioned in constant contact with fluid within one
of the first fluid chamber and the second fluid chamber.
7. The hydraulic bushing assembly according to claim 1, further
comprising a first intermediate insert and a second intermediate
insert spaced apart from the first intermediate insert, the
elastomeric bushing encapsulating the first intermediate insert and
the second intermediate insert, wherein the first insert includes a
groove defining the path of the fluid passageway.
8. The hydraulic bushing assembly according to claim 1, wherein the
outer tube includes at least one curled end.
9. The hydraulic bushing assembly according to claim 1, wherein the
elastomeric bushing includes axially spaced apart flanges
interconnected by axially extending webs, wherein each web is a
portion of each of the first and second fluid chambers.
10-20. (canceled)
21. The hydraulic bushing assembly according to claim 1, wherein
the inner tube includes a longitudinal axis, the internal snubber
being radially positioned to at least partially enter the window
and partially overlap the frame.
22. A hydraulic bushing assembly comprising: an inner tube
including an outer surface; an outer tube circumscribing the inner
tube; a travel limiter fixed to the inner tube, the travel limiter
being centered along the length of the inner tube and radially
outwardly protruding from the inner tube; an elastomeric bushing
bonded to an outer surface of the travel limiter; a snubber
assembly positioned within the outer tube and spaced apart from the
travel limiter when the bushing is in an unloaded state, wherein
the travel limiter is operable to move into contact with the
snubber assembly when the bushing is in a loaded state, the snubber
assembly including an outer snubber and a spaced apart inner
snubber interconnected with an elastomeric cushion, the outer
snubber including a frame surrounding a window, the frame being in
contact with the outer tube, the cushion extending through the
window, wherein the inner snubber is aligned with the window, the
inner snubber being centrally positioned along an axial extent of
the outer tube; first and second fluid chambers; and a fluid
passageway defined by the elastomeric bushing and the outer tube,
the fluid passageway extending between the first and second fluid
chambers, wherein movement of the inner tube relative to the outer
tube causes fluid transfer between the first fluid chamber and the
second fluid chamber.
23. The hydraulic bushing assembly according to claim 1, wherein
the travel limiter includes a protrusion with a distal surface.
24. The hydraulic bushing assembly according to claim 22, or in the
protrusion includes a distal surface.
25. The hydraulic bushing assembly according to claim 3, wherein
the stop face and the travel limiter distal surface are spherically
shaped.
26. The hydraulic bushing assembly according to claim 2, wherein
the inner tube extends along a longitudinal axis and the protrusion
radially extends within one of the fluid chambers.
27. The hydraulic bushing assembly according to claim 3, wherein
the stop face is positioned in constant contact with fluid within
one of the first fluid chamber and the second fluid chamber.
28. The hydraulic bushing assembly according to claim 1, further
comprising a first intermediate insert and a second intermediate
insert spaced apart from the first intermediate insert, the
elastomeric bushing encapsulating the first intermediate insert and
the second intermediate insert, wherein the first insert includes a
groove defining the path of the fluid passageway.
29. The hydraulic bushing assembly according to claim 1, wherein
the outer tube includes at least one curled end.
30. The hydraulic bushing assembly according to claim 1, wherein
the elastomeric bushing includes axially spaced apart flanges
interconnected by axially extending webs, wherein each web is a
portion of each of the first and second fluid chambers.
Description
FIELD
[0001] The present disclosure relates to a hydraulic bushing. More
particularly, the present invention relates to a hydraulic bushing
with an internal snubber.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not
constitute prior art.
[0003] Hydraulic bushings typically used in automobile suspensions
are expected to damp low frequency, large displacement,
oscillations as well as contribute to high frequency acoustic
isolation from relatively small displacements. Hydraulic bushings
typically have two hydraulic chambers connected by a channel. The
resonance of the fluid in the channel creates a mass damper effect.
A compliant travel limiter is utilized in some designs to improve
the durability of the bushing by transferring high loads from an
inner tube to an outer tube through the travel limiter instead of
the elastomeric bushing.
[0004] Challenges arise regarding packaging a compliant travel
limiter into a hydraulic bushing application that has high load
carrying capabilities. Compliant travel limiter construction may
include injection molding a rubber pad to inner components that
will transfer the load to an outer component. Durability of the
rubber pad may be a concern due to residual tensile stresses
arising at the completion of the injection molding process.
Additional challenges may arise pertaining to the contact surface
area between rubber and adjacent components within the hydraulic
bushing. Known travel limiter designs may experience undesirably
high loads during operation which may increase the likelihood of
tears in the rubber.
SUMMARY
[0005] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the
description and specific examples are intended for purposes of
illustration only and are not intended to limit the scope of the
present disclosure.
[0006] A hydraulic bushing assembly comprises an inner tube
including an outer surface, an outer tube circumscribing the inner
tube, a travel limiter fixed to the inner tube, an elastomeric
bushing bonded to an outer surface of the travel limiter, a snubber
assembly positioned within the outer tube and spaced apart from the
travel limiter when the bushing is in an unloaded state. The travel
limiter is operable to move into contact with the snubber assembly
when the bushing is in a loaded state. The snubber assembly
includes an outer snubber and a spaced apart inner snubber
interconnected with an elastomeric cushion. The outer snubber
includes a frame surrounding a window and in contact with the outer
tube. The cushion extends through the window and the inner snubber
is aligned with the window. The hydraulic bushing further comprises
first and second fluid chambers and a fluid passageway defined by
the elastomeric bushing and the outer tube. The fluid passageway
extends between the first and second fluid chambers. Movement of
the inner tube relative to the outer tube causes fluid transfer
between the first fluid chamber and the second fluid chamber.
[0007] In another aspect, a hydraulic bushing assembly comprises an
inner tube, a travel limiter surrounding the inner tube, a first
intermediate insert, a second intermediate insert spaced apart from
the first intermediate insert, an elastomeric bushing disposed
around the inner tube and including a first flange encapsulating
the first intermediate insert and a second flange encapsulating the
second intermediate insert. The first and second flanges are spaced
apart a first distance when the elastomeric bushing is in an
unloaded, free state. An outer tube circumscribes the elastomeric
bushing. The elastomeric bushing and the outer tube at least
partially define first and second fluid chambers. The first and
second flanges are spaced apart a second distance less than the
first distance when compressed within an axial extent of the outer
tube. The hydraulic bushing further comprises a snubber spaced
apart from the travel limiter and positioned in the outer tube to
limit displacement of the travel limiter. A fluid passageway
extends between the first and second fluid chambers such that
movement of the inner tube relative to the outer tube causes fluid
transfer between the first fluid chamber and the second fluid
chamber.
DRAWINGS
[0008] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way.
[0009] FIG. 1 is a perspective view of a hydraulic bushing assembly
in accordance with one embodiment of the present disclosure;
[0010] FIG. 2 is an exploded perspective view of the hydraulic
bushing assembly illustrated in FIG. 1;
[0011] FIG. 3 is a cross-sectional view of the hydraulic bushing
assembly illustrated in FIG. 1;
[0012] FIG. 4 is an exploded perspective view of an alternate
embodiment snubber;
[0013] FIG. 5 is a perspective view of the alternate embodiment
snubber;
[0014] FIG. 6 is a cross-sectional view of the hydraulic bushing
illustrated in FIG. 1 in a free and unloaded state; and
[0015] FIG. 7 is another cross-sectional view of the hydraulic
bushing illustrated in FIG. 1 in a free and unloaded state.
DETAILED DESCRIPTION
[0016] Example embodiments will now be described more fully with
reference to the accompanying drawings. Example embodiments are
provided so that this disclosure will be thorough, and will fully
convey the scope to those who are skilled in the art. Numerous
specific details are set forth such as examples of specific
components, devices, and methods, to provide a thorough
understanding of embodiments of the present disclosure. It will be
apparent to those skilled in the art that specific details need not
be employed, that example embodiments may be embodied in many
different forms and that neither should be construed to limit the
scope of the disclosure. In some example embodiments, well-known
processes, well-known device structures, and well-known
technologies are not described in detail.
[0017] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0018] When an element or layer is referred to as being "on,"
"engaged to," "connected to," or "coupled to" another element or
layer, it may be directly on, engaged, connected or coupled to the
other element or layer, or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on," "directly engaged to," "directly connected to," or
"directly coupled to" another element or layer, there may be no
intervening elements or layers present. Other words used to
describe the relationship between elements should be interpreted in
a like fashion (e.g., "between" versus "directly between,"
"adjacent" versus "directly adjacent," etc.). As used herein, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0019] Although the terms first, second, third, etc. may be used
herein to describe various elements, components, regions, layers
and/or sections, these elements, components, regions, layers and/or
sections should not be limited by these terms. These terms may be
only used to distinguish one element, component, region, layer or
section from another region, layer or section. Terms such as
"first," "second," and other numerical terms when used herein do
not imply a sequence or order unless clearly indicated by the
context. Thus, a first element, component, region, layer or section
discussed below could be termed a second element, component,
region, layer or section without departing from the teachings of
the example embodiments.
[0020] Spatially relative terms, such as "inner," "outer,"
"beneath," "below," "lower," "above," "upper," and the like, may be
used herein for ease of description to describe one element or
feature's relationship to another element(s) or feature(s) as
illustrated in the figures. Spatially relative terms may be
intended to encompass different orientations of the device in use
or operation in addition to the orientation depicted in the
figures. For example, if the device in the figures is turned over,
elements described as "below" or "beneath" other elements or
features would then be oriented "above" the other elements or
features. Thus, the example term "below" can encompass both an
orientation of above and below. The device may be otherwise
oriented (rotated 90 degrees or at other orientations) and the
spatially relative descriptors used herein interpreted
accordingly.
[0021] FIGS. 1-3 illustrate a hydraulic bushing assembly which is
designated generally by reference numeral 10. Hydraulic bushing
assembly 10 comprises an inner tube 12, an elastomeric bushing 16,
a first intermediate insert 20, a second intermediate insert 24, a
first snubber 28, a second snubber 32, a travel limiter 36, and an
outer tube 40.
[0022] Inner tube 12 is a metallic member preferably constructed
from mild steel such as SAE J403 1008-1010. Inner tube 12 includes
a through bore 44 for receipt of a fastener (not shown) to
interconnect hydraulic bushing assembly 10 to a vehicle component
such as a suspension control arm. A plurality of circumferentially
spaced apart castellations 48 extend from either end of inner tube
12. Castellations 48 may cooperate with an adjacent member to which
hydraulic bushing assembly 10 is coupled to assist in alignment and
maintaining rotational position of inner tube 12. As some portions
of inner tube 12 may be exposed to the environment, the exterior
surfaces of inner tube 12 may be treated with a Zn--Ni plating.
[0023] First intermediate insert 20 and second intermediate insert
24 are identical to one another. As such, only first intermediate
insert 20 will be described in detail. Similar features on second
intermediate insert 24 will be identified with an "a" suffix. First
intermediate insert 20 includes a ring shaped body 52 having an
outer cylindrical surface 56, an inner surface 60, an outer end
face 64 and an inner end face 68. Both first intermediate insert 20
and second intermediate insert 24 are constructed from either a
plastic material such as nylon PA6 that may be reinforced and
designated as 35% glass filled or an aluminum die casting
alloy.
[0024] A channel 72 circumferentially extends along outer
cylindrical surface 56 for a majority of the circumferential extent
of body 52. Channel 72 includes a first axially extending portion
76 that extends to inner end face 68 to define a first port 80.
Channel 72 includes a second axially extending portion 84 that
extends to inner end face 68 to define a second port 88. A pair of
diametrically opposed tabs 92, 96 axially extend from inner end
face 68. A plurality of recesses 100 axially extend into body 52
from outer end face 64. Each of first intermediate insert 20 and
second intermediate insert 24 are entirely encapsulated within
elastomeric bushing 16. Molten elastomeric material fills recesses
100 during the over-molding process to enhance the structural
interconnection and maintain the desired relative position between
the other over molded components and the elastomeric bushing
16.
[0025] Second intermediate insert 24 is positioned in an opposed
mirror orientation to first intermediate insert 20 such that tabs
92 and 92a are axially aligned with one another. Tabs 96 and 96a
are also axially aligned with one another.
[0026] Travel limiter 36 may be constructed as an injection molded
plastic component bonded to an external surface 138 of inner tube
12. Travel limiter 36 includes a body portion 104 with two
integrally formed thin-wall cylindrical portions 106 positioned on
opposite sides of body portion 104. A cylindrically shaped through
bore is defined by an inner surface 110. An outer surface 112 of
body portion 104 is substantially spherically shaped. A pair of
diametrically opposed protrusions 116, 120 radially outwardly
extend from outer surface 112. Each protrusion 116, 120 includes a
spherically shaped contact surface 124, 128, respectively. Travel
limiter 36 may be formed from a plastic material similar to or
different from the material used to construct first intermediate
insert 20 and second intermediate insert 24. In the instant
example, travel limiter 36 is also constructed from a 35%
glass-filed nylon PA6.
[0027] In an exemplary method of manufacturing hydraulic bushing
assembly 10, travel limiter 36 is injected molded and
simultaneously bonded to inner tube 12 to define a sub-assembly.
Subsequently, each of first intermediate insert 20, second
intermediate insert 24 and the sub-assembly of inner tube and
travel limiter 36 are placed into an injection mold in a spaced
apart relationship. Liquid elastomer is injected into the mold to
bond each of the previously listed components to one another. Once
solidified, elastomeric bushing 16 includes a first flange 142 and
a second flange 146 integrally formed with and radially outwardly
extending from travel limiter 36. A first web 150 and a second web
154 longitudinally extend to interconnect first flange 142 with
second flange 146. Each of first web 150 and second web 154
radially outwardly extend from travel limiter 36. First flange 142,
second flange 146, inner portion 134 and first and second webs 150,
154 cooperate with one another to define a first cavity 160 and a
diametrically opposed second cavity 164.
[0028] First flange 142 includes a circumferentially extending
channel 168 that extends for a majority of the circumferential
extent of first flange 142. Channel 168 includes a first axially
extending portion 172 that defines a first port 176 in
communication with first cavity 160. Channel 168 includes a second
axially extending portion 180 that defines a second port 184 in
fluid communication with second cavity 164. When hydraulic bushing
assembly 10 is completely assembled, first cavity 160 and second
cavity 164 in cooperation with first snubber 28 and second snubber
32 define a first fluid chamber 188 and a second fluid chamber
190.
[0029] Second flange 146 is substantially the mirror image of first
flange 142 and includes a channel 194. Channel 194
circumferentially extends to define a third port 198 in fluid
communication with first fluid chamber 188 and a fourth port 202
include fluid communication with second fluid chamber 190. Channel
168 provides fluid communication between first fluid chamber 188
and second fluid chamber 190 via first port 176 and second port
184. Based on the fluid paths described and the non-rigid nature of
elastomeric bushing 16, fluid flow occurs between first fluid
chamber 188 and second fluid chamber 190 during relative movement
between inner tube 12 and outer tube 40. The flow of fluid between
fluid chambers 188, 190 through channels 168, 194 creates a
mass-damper effect within hydraulic bushing assembly 10.
[0030] Elastomeric bushing 16 includes a plurality of beads 238
circumferentially extending about its outer surface shaped and
sized to sealingly engage inner surface 260 of outer tube 40 and
fully define the fluid passageways comprising channels 168, 194.
Axially extending beads 246 radially outwardly protrude from first
web 150 and second web 154 to sealingly engage inner surface 260 of
outer tube 40 and define fluid chambers 188, 190.
[0031] Elastomeric bushing 16 may further include radially
outwardly extending ribs 203 (FIG. 1). Ribs 203 are diametrically
opposed and positioned at an angular orientation associated with
the rotational position of first and second webs 150, 154. Ribs 203
offer a visual indication of the position of the components within
hydraulic bushing assembly 10 after the component has been
completely constructed. Ribs 203 may cooperate with mating features
in an adjacent vehicle component to properly align travel limiter
36 in relation to the direction of expected maximum loading.
[0032] First snubber 28 and second snubber 32 are substantially
similar to one another. As such, only first snubber 28 will be
described in detail. First snubber 28 includes an inner snubber
204, an outer snubber 206, and a cushion 208 positioned
therebetween. Inner snubber 204 is substantially semicircular in
shape having a curved wall 210 with an outer surface 214 and an
inner surface 220. Inner surface 220 is substantially
spherically-shaped and may also be referred to as stop face 220.
Cushion 208 is an elastomeric material which is bonded to inner
snubber 204 and outer snubber 207. Liquid elastomer is injected
into the mold to bond each of the previously listed components to
one another.
[0033] Outer snubber 206 is shaped as a curved open frame having a
first leg 224 spaced apart from a second leg 228. A first web 232
interconnects ends of first and second legs 224, 228. A second web
236 interconnects the opposite ends of legs 224, 228. Legs 224, 228
and webs 232, 236 define an open window 240. A recess 244
circumferentially surrounds a window 240 and radially extends from
an inner surface 248 of outer snubber 206. Outer snubber 206
includes an opposite outer surface 252.
[0034] Cushion 208 is sized and shaped to fill window 240 and be
positioned within recess 244. Window 240 is sized to be larger than
inner snubber 204. As such, loads applied to inner surface 220 of
inner snubber 204 pass through cushion 208 and are reacted by outer
tube 40. As best depicted in FIG. 3, cushion 208 includes ribs 256
that are placed in compression and in direct engagement with an
inner surface 260 of outer tube 40. Gaps 264 exist between portions
of cushion 208 and outer tube 240 to provide volumes for cushion
208 to fill if required during high-load conditions.
[0035] It should be appreciated that outer surface 252 of outer
snubber 206 directly engages inner surface 260 of outer tube 40. In
the embodiment including window 240, the surface contact area of
cushion 208 with inner surface 260 is greater than the area of
outer surface 252 of outer snubber 206 in contact with surface 260
of outer tube 40. In addition, the surface contact area between
inner snubber 204 and either of protrusions 116, 120 is less than
the surface contact area between cushion 208 and outer tube 40.
This geometrical arrangement provides a reduction in contact stress
and unit loading of the elastomeric cushion 208. A higher load
capacity for a given bushing size may be achieved. The tendency for
cushion 208 to rupture or otherwise be compromised could also be
minimized by the described arrangement.
[0036] Each of first snubber 28 and second snubber 32 includes
scallops 230 through which fluid flows during a fluid transfer
between first fluid chamber 188 and second fluid chamber 190. A
groove 234 is formed at one end of each first and second snubber
28, 32 for engagement with a respective portion of elastomeric
bushing 16 to properly aligned the first and second snubbers 28, 32
within first cavity 160 and second cavity 164, respectively.
[0037] FIGS. 4 and 5 depict a second embodiment snubber 28a. First
snubber 28a and a second snubber, not shown, are substantially
similar to one another, if not identical. Accordingly, only first
snubber 28a will be described in detail. Similar elements will be
identified with the same reference numerals. First snubber 28a
includes an inner snubber 204a, an outer snubber 206a and a cushion
208a positioned therebetween. Outer snubber 206a is substantially
semicircular in shape having a curved wall 210a with an outer
surface 214a and an inner surface 218a. Inner snubber 204a includes
an outer surface 222a. Cushion 208a is an elastomer, such as
rubber, bonded to inner surface 218a of outer snubber 206a and
outer surface 222a of inner snubber 204a. An optional aperture 228a
extends through curved wall 210a. Aperture 228a is filled with
molten elastomer during the injection molding process when inner
snubber 204a is bonded to outer snubber 206a via cushion 208a.
Spherically-shaped stop face 226a circumferentially extends along
the inner radially extent of inner snubber 204a. Inner snubber 204a
and outer snubber 206a may be constructed from a plastic material
as previously described or alternatively from aluminum or an
aluminum alloy.
[0038] With reference to FIGS. 6 and 7, elastomeric bushing 16 is
depicted in a free, unloaded and pre-compressed state. After the
liquid elastomer used to form elastomeric bushing 16 has solidified
subsequent to the injection molding process, undesirable residual
tensile stresses may exist along the external surfaces of the
elastomeric bushing 16. Residual tensile stresses present at a root
272 of first flange 142 and a root 276 of second flange 146 may be
of particular concern as these locations are also geometrical
stress concentrations. It should be appreciated that in the
as-molded, free state, first flange 142 is splayed apart from
second flange 146 a greater distance than the spacing between the
first and second flanges 142, 146 when the elastomeric bushing 16
is an assembled condition as depicted in FIG. 3. FIG. 6 clearly
depicts the unloaded, free state by spaces 280 that exist between
first flange 142 and first snubber 28 as well as the space 280
between second flange 146 and first snubber 28. FIG. 7 is taken
along a different section line cut through first web 150 and second
web 154. When elastomeric bushing 16 is in the free, unloaded
state, gaps 284 are provided to allow subsequent compression and
movement of first flange 142 toward second flange 146.
[0039] Prior to positioning outer tube over elastomeric bushing 16,
all components are submersed in a fluid. Once submersed, first
snubber 28 is positioned within first cavity 160 and second snubber
32 is positioned within second cavity 164 to define fluid filled
chambers 188, 190. Next, outer tube 40 is axially translated over
and placed in pressed engagement with elastomeric bushing 16 and
the snubbers 28, 32. First flange 142 and second flange 146 are
compressed toward one another to place roots 272, 276 in
compression. At this time, gaps 284 are reduced or closed
completely. Spaces 280 are eliminated as first flange 142 and
second flange 146 are displaced into engagement with first and
second snubbers 28, 32. Distal ends 250 of outer tube 40 are
mechanically curled or otherwise deflected to maintain the
compressed positon of first and second flanges 142, 146 as well as
a desired relative axial position of outer tube 40 relative to
elastomeric bushing 16. Fluid chambers 188, 190 may be filled with
any suitable liquid such as water or glycol.
[0040] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
* * * * *