U.S. patent application number 13/089841 was filed with the patent office on 2011-08-11 for fluid-elastomeric damper assembly including internal pumping mechanism.
Invention is credited to Peter Jones, Donald Russell, Eric Seitter.
Application Number | 20110193275 13/089841 |
Document ID | / |
Family ID | 32175987 |
Filed Date | 2011-08-11 |
United States Patent
Application |
20110193275 |
Kind Code |
A1 |
Russell; Donald ; et
al. |
August 11, 2011 |
FLUID-ELASTOMERIC DAMPER ASSEMBLY INCLUDING INTERNAL PUMPING
MECHANISM
Abstract
A fluid-elastomeric damper assembly operable for damping
relative motion between a first structure and a second structure
including a housing structure grounded to the first structure and a
plurality of elastomer seals coupled to the housing structure, the
housing structure and the plurality of elastomer seals defining a
fluid-elastomeric chamber operable for containing a fluid. The
fluid-elastomeric damper assembly also including one or more piston
structures disposed within the housing structure and the
fluid-elastomeric chamber, the one or more piston structures
grounded to the first structure and driven by the second structure,
and the one or more piston structures each including a first
substantially fluid-filled chamber and a second
substantially-fluid-filled chamber in communication via an orifice,
the first substantially fluid-filled chamber and the second
substantially fluid-filled chamber also in communication with the
fluid-elastomeric chamber. The housing structure is operable for
pumping the fluid through the orifice.
Inventors: |
Russell; Donald; (Fairview,
PA) ; Jones; Peter; (Erie, PA) ; Seitter;
Eric; (Erie, PA) |
Family ID: |
32175987 |
Appl. No.: |
13/089841 |
Filed: |
April 19, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11549774 |
Oct 16, 2006 |
7931258 |
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13089841 |
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10703068 |
Nov 6, 2003 |
7137624 |
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11549774 |
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10288868 |
Nov 6, 2002 |
6758466 |
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10703068 |
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Current U.S.
Class: |
267/140.13 |
Current CPC
Class: |
B64C 27/001 20130101;
F16F 13/08 20130101; B64C 27/35 20130101 |
Class at
Publication: |
267/140.13 |
International
Class: |
F16F 13/08 20060101
F16F013/08 |
Claims
1-7. (canceled)
8. A fluid-elastomeric damper assembly operable for damping a
relative motion between a first structure and a second structure,
said fluid-elastomeric damper assembly including: at least a first
elastomer seal fixedly attached to a housing, said at least first
elastomer seal and said housing providing an external
fluid-elastomeric chamber operable for containing a damper fluid,
an internal pumping mechanism, said internal pumping mechanism
including a first substantially fluid-filled pumping chamber, a
second substantially fluid-filled pumping chamber, at least one
internal pumping restriction between said first substantially
fluid-filled pumping chamber and said second substantially
fluid-filled pumping chamber and at least one fluid moving internal
pumping piston pumping said fluid through said at least one
internal pumping restriction with a linear motion, said internal
pumping mechanism disposed within said external fluid-elastomeric
chamber with said first internal pumping mechanism in fluid
communication with said external fluid-elastomeric chamber, wherein
said internal pumping mechanism is driven by said relative motion
between said first structure and said second structure and said at
least one fluid moving internal pumping piston forces said fluid
through said at least one internal pumping restriction between said
first substantially fluid-filled pumping chamber and said second
substantially fluid-filled pumping chamber wherein said internal
pumping mechanism does not rely on said first elastomer seal to
pump said damper fluid through said at least one internal pumping
restriction.
9. The fluid-elastomeric damper assembly of claim 8, wherein said
at least one fluid moving piston is a linearly reciprocating piston
structure.
10. The fluid-elastomeric damper assembly of claim 8, wherein said
housing includes a substantially cup-shaped member.
11. The fluid-elastomeric damper assembly of claim 8, wherein said
housing includes a substantially disc-shaped member.
12. The fluid-elastomeric damper assembly of claim 8, including a
substantially cylindrical elastomer seal.
13. The fluid-elastomeric damper assembly of claim 8, having a
plurality of circular diameters.
14-32. (canceled)
Description
[0001] This Application is a Continuation of U.S. patent
application Ser. No. 10/703,068 filed Nov. 6, 2003, which is a
Continuation-in-Part (CIP) of U.S. patent application Ser. No.
10/288,868 filed Nov. 6, 2002, now U.S. Pat. No. 6,758,466, the
priority to which are hereby claimed, and are hereby incorporated
by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a damper assembly
used to control movement/vibration in a mechanical system or the
like. More specifically, the present invention relates to a
fluid-elastomeric damper assembly including an internal pumping
mechanism. The fluid-elastomeric damper assembly may be used, for
example, to control movement/vibration in the lead-lag direction of
the rotor of a rotary-wing aircraft or the like.
BACKGROUND OF THE INVENTION
[0003] Conventional fluid-elastomeric damper assemblies (also
referred to as "fluidlastic.RTM." damper assemblies commercially
available from Lord Corporation, 111 Lord Drive, POBOX 8012, Cary,
N.C. 27511) typically incorporate an elastomer seal, such as a
rubber seal or the like, containing a fluid, such as hydraulic
fluid or the like. This elastomer seal is bonded, fixedly attached,
or otherwise coupled to the major metal components of the
fluid-elastomeric damper assembly which are, in turn, fixedly
attached or otherwise coupled to one or more moving/vibrating
structures. These moving/vibrating structures may include, for
example, the flex-beam and the pitch case of the rotor of a
rotary-wing aircraft or the like. The elastomer seal is used to
pump the fluid through a restriction, such as one or more orifices
or the like, creating an increase in the fluid pressure which
reacts against the elastomer seal surface, resulting in a damping
force resisting the movement/vibration of the one or more
moving/vibrating structures. The fluid may be pumped, for example,
from one chamber disposed within the elastomer seal or an
associated structure to another chamber disposed within the
elastomer seal or an associated structure, or from one chamber
formed by the major metal components of the fluid-elastomeric
damper assembly to another chamber formed by the major metal
components of the fluid-elastomeric damper assembly.
[0004] Advantageously, the elastomer seal is substantially
leak-resistant and is capable of accommodating movement/vibration
in a plurality of directions. However, in order to create a desired
damping force, the volume stiffness, i.e., the elastomer stiffness
reacting the fluid pressure, of the fluid-elastomeric damper
assembly must be sufficiently high and the observed increase in the
stiffness of the elastomer seal which results from the increased
fluid pressure must be limited to within a predetermined range.
This is not always possible, for example, in the control of
movement/vibration in the lead-lag direction of the rotor of a
rotary-wing aircraft or the like.
[0005] Thus, what is needed is a fluid-elastomeric damper assembly
including one or more elastomer seals, but also including an
internal pumping mechanism that does not rely on the one or more
elastomer seals to pump the fluid through the restriction, i.e.,
through the one or more orifices. This would allow for the creation
of relatively higher damping forces in relation to the elastomer
stiffness for resisting relatively greater movement/vibration of
the one or more moving/vibrating structures than is possible with
conventional fluid-elastomeric damper assemblies. Although the
assemblies, mechanisms, and methods of the present invention are
described herein below in conjunction with the flex-beam and the
pitch case of the rotor of a rotary-wing aircraft or the like, the
assemblies, mechanisms, and methods of the present invention may be
used in conjunction with any mechanical system or the like
including one or more moving/vibrating structures that it is
desirable to damp.
BRIEF SUMMARY OF THE INVENTION
[0006] In various embodiments of the present invention, a
fluid-elastomeric damper assembly includes at least a first
elastomer seal, such as a rubber seal or the like, disposed at a
first end of the fluid-elastomeric damper assembly and a second
elastomer seal, such as a rubber seal or the like, disposed at a
second end of the fluid-elastomeric damper assembly. The first
elastomer seal is fixedly attached or otherwise coupled to a first
moving/vibrating structure, such as a flex-beam of the rotor of a
rotary-wing aircraft or the like, and the second elastomer seal is
fixedly attached or otherwise coupled to a second moving/vibrating
structure, such as a pitch case of the rotor of a rotary-wing
aircraft or the like. The first elastomer seal and the second
elastomer seal are both bonded, fixedly attached, or otherwise
coupled to a housing structure including, for example, a first
housing member and a second housing member. Together, the first
elastomer seal, the second elastomer seal, and the housing
structure are operable for containing a fluid, such as hydraulic
fluid or the like. An internal pumping mechanism including one or
more piston structures and a piston structure housing is also
disposed within the housing structure. The internal pumping
mechanism is grounded to or integrally formed with the first
moving/vibrating structure and moves in relation to the housing
structure and the second moving/vibrating structure to which the
housing structure is grounded. The internal pumping mechanism is
configured such that, when the internal pumping mechanism moves
with respect to the housing structure and the second
moving/vibrating structure, the fluid surrounding and disposed
within the internal pumping mechanism is pumped from a first
chamber disposed within each of the one or more piston structures
to a second chamber disposed within each of the one or more piston
structures through a restriction, i.e., an orifice. Optionally, the
relative size of the restriction is controlled by an adjustable
pressure relief device and/or a temperature-compensating device.
Advantageously, the first elastomer seal, the second elastomer
seal, and the housing structure provide a fluid-elastomeric chamber
operable for containing the fluid and in which the internal pumping
mechanism may be submerged. This fluid-elastomeric chamber is
flexible and allows the internal pumping mechanism to damp
movement/vibration in a primary direction with a relatively high
damping force. Additionally, movement/vibration in a plurality of
other directions are accommodated by the internal pumping mechanism
by design, without damping force.
[0007] In one embodiment of the present invention, a
fluid-elastomeric damper assembly includes a housing structure, a
first elastomer seal coupled to the housing structure, and a second
elastomer seal coupled to the housing structure. The housing
structure, the first elastomer seal, and the second elastomer seal
define a fluid-elastomeric chamber operable for containing a fluid.
The fluid-elastomeric damper assembly also includes an internal
pumping mechanism disposed within the fluid-elastomeric
chamber.
[0008] In another embodiment of the present invention, a
fluid-elastomeric damper assembly operable for damping relative
motion between a first structure and a second structure includes a
housing structure coupled the first structure, a first elastomer
seal coupled to the housing structure, wherein the first elastomer
seal is also coupled to the second structure, and a second
elastomer seal coupled to the housing structure. Again, the housing
structure, the first elastomer seal, and the second elastomer seal
define a fluid-elastomeric chamber operable for containing a fluid.
The fluid-elastomeric damper assembly also includes an internal
pumping mechanism disposed within the fluid-elastomeric chamber,
wherein the internal pumping mechanism is coupled to the second
elastomer seal.
[0009] In a further embodiment of the present invention, a
fluid-elastomeric damper assembly operable for damping relative
motion between a first structure and a second structure includes a
housing structure grounded to the first structure and a plurality
of elastomer seals coupled to the housing structure, wherein the
housing structure and the plurality of elastomer seals define a
fluid-elastomeric chamber operable for containing a fluid. The
fluid-elastomeric damper assembly also includes one or more piston
structures disposed within the housing structure and the
fluid-elastomeric chamber, wherein the one or more piston
structures are grounded to the first structure and driven by the
second structure, and wherein the one or more piston structures
each include a first substantially fluid-filled chamber and a
second substantially-fluid-filled chamber in communication via an
orifice, the first substantially fluid-filled chamber and the
second substantially fluid-filled chamber also in communication
with the fluid-elastomeric chamber. The housing structure is
operable for pumping the fluid through the orifice.
[0010] In a still further embodiment of the present invention, a
method for damping relative motion between a first structure and a
second structure includes grounding a housing structure to the
first structure, coupling a plurality of elastomer seals to the
housing structure, wherein the housing structure and the plurality
of elastomer seals define a fluid-elastomeric chamber, and
disposing a fluid within the fluid-elastomeric chamber. The method
also includes disposing one or more piston structures within the
housing structure and the fluid-elastomeric chamber and grounding
the one or more piston structures to the first structure, wherein
the one or more piston structures each include a first
substantially fluid-filled chamber and a second
substantially-fluid-filled chamber in communication via an orifice,
the first substantially fluid-filled chamber and the second
substantially fluid-filled chamber also in communication with the
fluid-elastomeric chamber. Again, the housing structure is operable
for pushing the fluid through the orifice. The method further
comprising driving the one or more piston structures with the
second structure.
[0011] It is to be understood that both the foregoing general
description and the following detailed description are exemplary of
the invention, and are intended to provide an overview or framework
for understanding the nature and character of the invention as it
is claimed. The accompanying drawings are included to provide a
further understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
various embodiments of the invention, and together with the
description serve to explain the principals and operation of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cross-sectional side (cord-wise) view of one
embodiment of the fluid-elastomeric damper assembly of the present
invention, highlighting an internal pumping device disposed with a
fluid-elastomeric chamber of the fluid-elastomeric damper assembly
(the top portion of FIG. 1 illustrating the internal pumping
device, the bottom portion of FIG. 1 illustrating the
fluid-elastomeric chamber);
[0013] FIG. 2 is a perspective view of the fluid-elastomeric damper
assembly of FIG. 1, again highlighting the internal pumping device
disposed with the fluid-elastomeric chamber of the
fluid-elastomeric damper assembly (the top portion of FIG. 2
illustrating the internal pumping device, the bottom portion of
FIG. 2 illustrating the fluid-elastomeric chamber);
[0014] FIG. 3 is an exploded perspective view of the
fluid-elastomeric damper assembly of FIGS. 1 and 2, again
highlighting the internal pumping device disposed with the
fluid-elastomeric chamber of the fluid-elastomeric damper
assembly;
[0015] FIG. 4 is a side (cord-wise) view of the fluid-elastomeric
damper assembly of FIGS. 1-3;
[0016] FIG. 5 is a cross-sectional front (beam-wise) view of the
fluid-elastomeric damper assembly of FIGS. 1-4 (the top portion of
FIG. 5 illustrating the internal pumping device, the bottom portion
of FIG. 5 illustrating the fluid-elastomeric chamber);
[0017] FIG. 6 is another cross-sectional side (cord-wise) view of
the fluid-elastomeric damper assembly of FIGS. 1-5 (the top portion
of FIG. 6 illustrating the internal pumping device, the bottom
portion of FIG. 6 illustrating the fluid-elastomeric chamber);
[0018] FIG. 7 is a cross-sectional top view of the
fluid-elastomeric damper assembly of FIGS. 1-6, again highlighting
the internal pumping device disposed with the fluid-elastomeric
chamber of the fluid-elastomeric damper assembly;
[0019] FIG. 8 is another perspective view of the fluid-elastomeric
damper assembly of FIGS. 1-7;
[0020] FIG. 9 is a top view of the fluid-elastomeric damper
assembly of FIGS. 1-8; and
[0021] FIG. 10 is a front (beam-wise) view of the fluid-elastomeric
damper assembly of FIGS. 1-9.
[0022] FIG. 11 shows an embodiment of the invention.
[0023] FIG. 12 shows an embodiment of the invention.
[0024] FIG. 13 shows an embodiment of the invention.
[0025] FIGS. 14A-C show embodiments of the invention.
[0026] FIG. 15 shows an embodiment of the invention.
[0027] FIG. 16 shows an embodiment of the invention.
[0028] FIG. 17 shows an embodiment of the invention.
[0029] FIGS. 18A-D show embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Additional features and advantages of the invention will be
set forth in the detailed description which follows, and in part
will be readily apparent to those skilled in the art from that
description or recognized by practicing the invention as described
herein, including the detailed description which follows, the
claims, as well as the appended drawings.
[0031] Reference will now be made in detail to the present
preferred embodiments of the invention, examples of which are
illustrated in the accompanying Drawings. The invention includes a
fluid-elastomeric damper assembly with a reciprocating piston
structure grounded to a first structure and driven by a second
structure with the piston structure submerged in a fluid and having
a first fluid filled chamber and a second fluid filled chamber
which communicate via a pump restriction orifice through which the
piston forces the fluid through. The invention includes
fluid-elastomeric damper assembly 10 includes a first elastomer
seal 12, such as a rubber seal or the like, disposed at a first end
14 of the fluid-elastomeric damper assembly 10 and a second
elastomer seal 16, such as a rubber seal or the like, disposed at a
second end 18 of the fluid-elastomeric damper assembly 10. The
first elastomer seal 12 and the second elastomer seal 16 are
fixedly attached or otherwise coupled to a first moving/vibrating
structure 20, such as a flex-beam of the rotor of a rotary-wing
aircraft or the like, and the first elastomer seal 12 and the
second elastomer seal 16 are fixedly attached or otherwise coupled
to a second moving/vibrating structure 22, such as a pitch case of
the rotor of a rotary-wing aircraft or the like. The first
elastomer seal 12 and the second elastomer seal 16 are both bonded,
fixedly attached, or otherwise coupled to a housing structure 24
including, for example, a first housing member 26, a second housing
member 28, and a third housing member 70. The first elastomer seal
12 and the second elastomer seal 16 are also both bonded, fixedly
attached, or otherwise coupled to a substantially circular base
plate 64. Together, the first elastomer seal 12, the second
elastomer seal 16, the housing structure 24, and the substantially
circular base plate 64 are operable for containing a fluid (not
shown), such as hydraulic fluid or the like. An internal pumping
mechanism 30 (described in greater detail herein below) is also
disposed within the housing structure 24. The internal pumping
mechanism 30 is grounded to the first moving/vibrating structure 20
and moves in relation to the housing structure 24 and the second
moving/vibrating structure 22 to which the housing structure 24 is
grounded. The internal pumping mechanism 30 is configured such
that, when the internal pumping mechanism 30 moves with respect to
the housing structure 24 and the second/moving vibrating structure
22, the fluid surrounding and disposed within the internal pumping
mechanism 30 is pumped from at least a first chamber 32 disposed
within the internal pumping mechanism 30 to at least a second
chamber 34 disposed within the internal pumping mechanism 30
through a restriction, i.e., an orifice 86 (FIG. 3,14A, 18).
Optionally, the relative size of the restriction is controlled by
an adjustable pressure relief device 36 and/or a
temperature-compensating device 38 (both described in greater
detail herein below). It should be noted that FIG. 1 illustrates an
upper fluid-elastomeric damper assembly 10 (top portion of FIG. 1)
including an internal pumping mechanism 30 and a lower
fluid-elastomeric damper assembly 10 (bottom portion of FIG. 1)
without an internal pumping mechanism 30. The
lower-fluid-elastomeric damper 10 assembly may, optionally, include
an internal pumping mechanism 30.
[0032] Advantageously, the first elastomer seal 12, the second
elastomer seal 16, the housing structure 24, and the substantially
circular base plate 64 provide a fluid-elastomeric chamber 40
operable for containing the fluid and in which the internal pumping
mechanism 30 may be submerged. This fluid-elastomeric chamber 40 is
flexible and allows the internal pumping mechanism 30 to damp
movement/vibration in a primary direction with a relatively high
damping force. Movement/vibration in a plurality of other
directions are also accommodated by design, due to the coupling
features of the internal pumping mechanism 30. It should be noted
that two (2) fluid-elastomeric damper assemblies 10 are illustrated
and used in combination such as in FIG. 1 (and in other drawings
described herein below) in order to damp lead-lag
movement/vibration in the rotor of a rotary-wing aircraft or the
like. FIG. 1 illustrates an upper fluid-elastomeric damper assembly
10 (top portion of FIG. 1) including an internal pumping mechanism
30 and a lower fluid-elastomeric damper assembly 10 (bottom portion
of FIG. 1) without an internal pumping mechanism 30. The
lower-fluid-elastomeric damper 10 assembly may, optionally, include
an internal pumping mechanism 30, for example as shown in FIG.
11.
[0033] Referring to FIGS. 2 and 3, the first elastomer seal 12
disposed at the first end 14 of the fluid-elastomeric damper
assembly 10 and the second elastomer seal 16 disposed at the second
end 18 of the fluid-elastomeric damper assembly 10 may, optionally,
include a plurality of metal or substantially rigid laminates
(shims) 50 (FIG. 3) or the like disposed within a rubber seal 52
(FIG. 3) or the like. This configuration provides both the first
elastomer seal 12 and the second elastomer seal 16 with
strength/rigidity and flexibility/pliability. Both the first
elastomer seal 12 and the second elastomer seal 16 may have a
substantially cylindrical or conical shape, although other suitable
shapes may be utilized. In an exemplary embodiment of the present
invention, the diameter of the second elastomer seal 16 is between
about one-third (1/3) and about three-quarters (3/4) the diameter
of the first elastomer seal 12. Other shapes and sizes may,
however, be used as necessary.
[0034] The first elastomer seal 12 is fixedly attached or otherwise
coupled to the first moving/vibrating structure 20, such as a
flex-beam of the rotor of a rotary-wing aircraft or the like, via a
first attachment mechanism 60. Likewise, the first elastomer seal
12 and the second elastomer seal 16 (FIG. 5) are fixedly attached
or otherwise coupled to the second moving/vibrating structure 22,
such as a pitch case of the rotor of a rotary-wing aircraft or the
like, via a second attachment mechanism 62. The first attachment
mechanism 60 may include, for example, the substantially circular
base plate 64 bonded, fixedly attached, or otherwise coupled to the
first elastomer seal 12 and the second elastomer seal 16. The base
plate 64 is fixedly attached or otherwise coupled to one or more
spanning members 66 that are, in turn, fixedly attached or
otherwise coupled to a compliant member 68 (FIG. 5) associated with
the first moving/vibrating structure 20. The base plate 64, the one
or more spanning members 66, and the compliant member 68 may be
made of, for example, a metal or any other substantially rigid
material. Optionally, the base plate 64, the one or more spanning
members 66, and/or the compliant member 68 may be integrally
formed. Although an exemplary first attachment mechanism 60 has
been described herein, any other first attachment mechanism 60
operable for fixedly attached or otherwise coupling the first
elastomer seal 12 and the base plate 64 to the first
moving/vibrating structure 20 may be used. As is described in
greater detail herein below, the second attachment mechanism 62
fixedly attached or otherwise coupled to the second
moving/vibrating structure 22 may, optionally, be integrally
formed/coincident with the housing structure 24 (FIG. 1).
Optionally, the fluid-elastomeric damper assembly 10 of the present
invention further includes a gas charge/discharge valve 63 operable
for introducing damping fluid and/or a gas, such as nitrogen or the
like, into and/or removing damping fluid and/or a gas from the
fluid-elastomeric chamber 40.
[0035] The first elastomer seal 12 and the second elastomer seal 16
are both bonded, fixedly attached, or otherwise coupled to the
housing structure 24, which may be made of, for example, a metal or
any other substantially rigid material. In an exemplary embodiment
of the present invention, the housing structure 24 includes a first
housing member 26 and a second housing member 28. The first housing
member 26 may be a substantially cup-shaped structure. Accordingly,
the second housing member 28 may be a substantially disc-shaped
structure. Optionally, the housing structure 24 may also include a
third, substantially disc-shaped housing member 70 that, together
with the first housing member 26 and the second housing member 28,
serves as the second attachment mechanism 62, fixedly attaching or
otherwise coupling the first elastomer seal 12 and the second
elastomer seal 16 to the second moving/vibrating structure 22. The
first housing member 26, the second housing member 28, and the
third housing member 70 may be bolted or otherwise attached
together, or they may be integrally formed. Together, the first
elastomer seal 12, the second elastomer seal 16, and the housing
structure 24 are operable for containing the fluid 72, such as
hydraulic fluid or the like, in the fluid-elastomeric chamber 40.
The fluid-elastomeric chamber 40 partially formed by the first
elastomer seal 12, the second elastomer seal 16, and the housing
structure 24 may, optionally, have a plurality of circular
diameters substantially conforming to the shape of the internal
pumping mechanism 30 disposed therein.
[0036] The internal pumping mechanism 30 disposed within the
housing structure 24 is grounded to the first moving/vibrating
structure 20 and moves in relation to the housing structure 24,
which is grounded to the second moving/vibrating structure 22. The
internal pumping mechanism 30 includes one or more piston
structures 80 disposed within a piston structure housing 82.
Preferably, the one or more piston structures 80 include one or
more substantially cylindrical, hollow structures. Optionally, the
one or more piston structures 80 and the piston structure housing
82 are integrally formed. Preferably, the one or more piston
structures 80 and the piston structure housing 82 are free to move
along one or more axially-extending structures 84 (FIG. 3), such as
hollow and/or solid rods or the like, integrally formed with the
piston assembly. Preferably the piston structure housing 82 is
grounded to the first moving/vibrating structure 20 by a stem piece
(not shown) that may be integrally formed with the base plate 64
or, optionally, may include a plurality of components. The piston
structure housing 82 may be constructed in multiple sections to
allow grounding of the piston structure housing 82 to the stem
piece of the base plate 64. The one or more piston structures
include a first chamber 32 and a second chamber 34 separated by the
piston assembly, with the first chamber 32 and the second chamber
34 in fluid communication through a pumping piston restriction,
i.e., an orifice 86. The piston assembly extends through the piston
structure housing 82 to the housing structure 24, to which it is
grounded. A plurality of holes 88 are disposed within the walls of
the one or more piston structures 80 and the piston structure
housing 82, allowing the fluid 72 to flow from the
fluid-elastomeric chamber 40 into the internal pumping mechanism
30. Additionally, clearance between the piston structure housing 82
and the piston assembly allow fluid to flow from the
fluid-elastomeric chamber 40 into the internal pumping mechanism
30. The fluid transfer between the fluid-elastomeric chamber 40 and
the internal pumping mechanism 30 is controlled by the clearance
around the piston assembly. The orifices 86 represents the path of
least resistance for the fluid 72. The internal pumping mechanism
30 is configured such that, when the one or more piston structures
80 and the piston structure housing 82 move with respect to the
housing structure 24 and the second/moving vibrating structure 22,
the fluid 72 surrounding and disposed within the one or more piston
structures is pumped from the first chamber 32 to the second
chamber 34 by the movement of piston structures 80 with the fluid
72 pumped back and forth between the first and second chambers
through the orifice 86. As shown in FIGS. 1-3, the relative linear
motion between the first moving structure 20 and the second moving
structure 22 drives the linear reciprocating motion of the internal
pumping mechanism 30, and forces the flow of fluid 72 through the
orifice 86 between the first chamber 32 and the second chamber 34.
As shown in FIGS. 11-14, the relative linear motion between the
first moving structure 20 and the second moving structure 22 drives
the rotational reciprocating motion of the internal pumping
mechanism 30 with the rotation of the rotational plate piston 80
forcing the flow of fluid 72 through the orifices 86 between the
first chambers 32 and the second chambers 34. Preferably a sliding
actuating pin decoupler ball linear to rotational linkage 200 and a
linear to rotational load transfer disk 300 couples the
reciprocating linear motion into the reciprocating rotational
motion that drives the rotational plate piston 80 in its piston
channel and forces the pumping flow of fluid 72 through orifices
86. As shown the pumping piston restriction orifice 86 can be in
the rotational plate piston 80, in the stationary plate housing 82,
and/or the clearance between the rotational plate piston 80 and the
housing 82. Preferably the actuating pin translates the linear
motion relative to the supporting structure into the rotational
motion of rotational plates radial pistons 80 which pumps fluid 72
through restrictions 86 between the chambers. This fluid
restriction 86 creates fluid damping forces. The reciprocating
rotating radial piston structures 80 reduce the dynamic stiffness
of the overall system by minimizing dynamic fluid forces on the
elastomer portions of the damping device allowing for greater
amounts of damping to be generated over devices which rely on
elastomeric interfaces to force fluid motion. The rotational nature
of the pistons allow for damping to be generated through large
amplitude linear motions of the support structure where linear
motion pistons may be troublesome. As shown in FIGS. 15-18, the
relative linear motion between the first moving structure 20 and
the second moving structure 22 drives the linear reciprocating
motion of the internal pumping mechanism 30 with the linear
parallel motion of the twin plate pistons 80 in the parallel piston
slide channels 402 forcing the flow of fluid 72 through the
orifices 86 between the first chambers 32 and the second chambers
34. Preferably a sliding actuating pin decoupler ball linear
linkage 400 couples the reciprocating linear motion into the
reciprocating linear motion of center piston slider 404 in piston
slider center channel 403 and twin plate pistons 80 in parallel
piston slide channels 402 and forces the pumping flow of the fluid
through orifices 86. As shown the pumping piston restriction
orifice 86 can be in the plate piston 80, the clearance between the
edge of plate piston 80 and the walls of the parallel piston slide
channels 402, and/or in the housing 82 such as orifices 86 through
the housing walls separating piston slide channels 402 and piston
slider center channels 403. The linear motion of plate pistons 80
in parallel piston slide channels 402 pumps fluid 72 through
restrictions 86 between the chambers 32 and 34. As shown in FIGS.
15-18 preferably the internal pumping mechanism 30 includes a pair
of linearly reciprocating plate pistons 80 that linearly
reciprocate in a pair of parallel piston slide channels 402, driven
by a piston slider 404 that linearly reciprocates in a piston
slider center channel 403. In a preferred embodiment the internal
pumping mechanism 30 includes a reciprocating plate piston 80 in a
piston channel, most preferably a linearly reciprocating plate
piston 80 in a piston slide channel 402.
[0037] The invention includes a fluid-elastomeric damper assembly
10 operable for damping a relative motion between a first structure
22 and a second structure 20, the fluid-elastomeric damper assembly
10 comprising: a plurality of elastomer seals 12, 16 coupled to the
housing 24 of the first structure 22, wherein the first structure
housing 24 and the plurality of elastomer seals define a
fluid-elastomeric chamber 40 operable for containing a fluid 72; an
internal pumping mechanism 30 with at least one fluid moving piston
80 disposed within the first structure housing 24 and the
fluid-elastomeric chamber 40, wherein the internal pumping
mechanism 30 is grounded to the first structure and driven by the
second structure, and wherein the at least one piston 80 forces
said fluid 72 through at least one orifice 86 between a first
substantially fluid-filled chamber 32 and a second
substantially-fluid-filled chamber 34 which are in fluid
communication with the fluid-elastomeric chamber 40; and wherein
said relative motion between said first structure 22 and said
second structure 20 is operable for pumping the fluid 72 through
said at least one orifice 86. In a preferred embodiment the at
least one fluid moving piston 80 is a linearly reciprocating piston
structure that pumps said fluid with a linear motion. In an
alternative preferred embodiment the at least one fluid moving
piston 80 is a rotational plate and pumps said fluid with a
rotational motion.
[0038] The invention includes a method for damping a relative
motion between a first structure 22 and a second structure 20. The
method comprises grounding a housing 24 to the first structure 22;
coupling a plurality of elastomeric seals 12,16 to the housing,
wherein the housing 24 and the plurality of elastomeric seals 12,16
provide a fluid-elastomeric chamber 40 for containing a fluid 72;
disposing a fluid 72 within the fluid-elastomeric chamber 40;
disposing an internal fluid pump 30 with at least one fluid moving
piston 80 within the housing and the fluid-elastomeric chamber and
grounding the internal fluid pump 30 to the first structure,
wherein the internal fluid pump 30 comprises a first substantially
fluid-filled chamber 32 and a second substantially fluid-filled
chamber 34 in communication via at least one orifice 86, said first
substantially fluid-filled chamber 32 and said second substantially
fluid-filled chamber 34 in communication with the fluid-elastomeric
chamber 40; wherein said relative motion between said first
structure 22 and said second structure 20 drives said at least one
fluid moving piston 80 to pump said fluid 72 through said at least
one orifice 86. In a preferred embodiment the at least one fluid
moving piston 80 is a linearly reciprocating piston and pumps said
fluid 72 through said at least one orifice 86 with a linear motion.
In an alternative preferred embodiment said at least one fluid
moving piston 80 is a rotational reciprocating piston and pumps
said fluid 72 through said at least one orifice 86 with a
rotational motion.
[0039] The invention includes a method of making a rotary-wing
aircraft fluid-elastomeric damper assembly 10 for damping a
relative motion between a first rotary-wing aircraft structure 22
and a second rotary-wing aircraft structure 20 in a rotary-wing
aircraft. The method includes coupling a plurality of elastomeric
seals 12, 16 to a housing 24, wherein the housing 24 and the
plurality of elastomeric seals 12, 16 provide a fluid-elastomeric
chamber 40 for containing a fluid 72; disposing an internal fluid
pump 30 with at least one fluid moving piston 80 within the housing
24 and the fluid-elastomeric chamber 40 and grounding the internal
fluid pump 30 to the first structure, disposing a fluid 72 within
the fluid-elastomeric chamber 40 wherein the internal fluid pump 30
comprises a first substantially fluid-filled chamber 32 and a
second substantially fluid-filled chamber 34 in communication via
at least one orifice 86, said first substantially fluid-filled
chamber 32 and said second substantially fluid-filled chamber 34 in
communication with the fluid-elastomeric chamber 40; wherein said
relative motion between said first structure 22 and said second
structure 20 drives said at least one fluid moving piston 80 to
pump said fluid 72 through said at least one orifice 86. In a
preferred embodiment said at least one fluid moving piston 80 is a
linearly reciprocating piston that pumps said fluid 72 through said
at least one orifice 86 with a linear motion. In an alternative
preferred embodiment said at least one fluid moving piston 80 is a
rotational reciprocating piston that pumps said fluid 72 through
said at least one orifice 86 with a rotational motion. In a
preferred embodiment the fluid moving piston 80 is a reciprocating
plate piston in a piston channel, most preferably a pair of
linearly reciprocating plate pistons 80 in a pair of parallel
piston slide channels 402.
[0040] Thus, the first elastomer seal 12, the second elastomer seal
16, the housing structure 24, and the base plate 64 provide a
fluid-elastomeric chamber 40 operable for containing the fluid 72
and in which the internal pumping mechanism 30 may be submerged.
This fluid-elastomeric chamber 40 is flexible and allows the
internal pumping mechanism 30 to damp movement/vibration in a
primary direction with a relatively high damping force.
[0041] Referring to FIG. 7, as described above, an adjustable
pressure relief device 36 and/or a temperature-compensating device
38 may be disposed within the one or more hollow axially-extending
structures 84 (i.e., the piston assembly) that carry the one or
more piston structures 80. The adjustable pressure relief device 36
includes a spring-loaded member 90 (FIG. 3) that partially
protrudes into the orifice 86 (FIG. 3), selectively blocking a
portion thereof and restricting the flow of fluid therethrough. The
spring-loaded member 90 of the adjustable pressure relief device 36
is displaced in the presence of relatively high fluid pressure. The
amount of force required to displace the spring-loaded member 90 of
the adjustable pressure relief device 36 may be adjusted via an
adjustment mechanism 92 (FIG. 3) disposed within the housing
structure 24. Additionally, the spring-side of the hollow structure
communicates with the fluid-elastomeric chamber 40 via one or more
holes 93 (FIG. 3) disposed within and through the walls of the
hollow portion of the piston assembly 84. These communication holes
93 allow a pressure differential to occur between the relatively
high dynamic pressure at the orifice 86 and the steady ambient
pressure of the fluid-elastomeric chamber 40, actuating the
adjustable pressure relief device 36. The temperature-compensating
device 38 includes a temperature-sensitive member 94 (FIG. 3) that
partially protrudes into the orifice 86, selectively blocking a
portion thereof and restricting the flow of fluid therethrough.
Preferably, the temperature sensitive member has a predetermined
thermal expansion coefficient such that the degree of flow
restriction may be varied for a given change in temperature. The
pressure relief device 36 and the temperature-compensating device
38 work together to provide a predetermined degree of damping. The
grounding of the piston assembly to the housing structure 24 is
accomplished by means of one or more retaining structures. The one
or more retaining structures may be solid and/or hollow and allow
for the adjustment of the internal mechanisms of the
fluid-elastomeric damper assembly 10. Preferably, the one or more
retaining structures form an integral seal with the piston assembly
and the housing structure 24. The one or more retaining structures
may allow access to either or both, if multiple retaining
structures disposed adjacent to the appropriate mechanisms are
used, the adjustable pressure relief device 36 and/or the
temperature-compensating device 38.
[0042] FIGS. 8, 9, and 10 provide several other views of the
fluid-elastomeric damper assembly of the present invention, for use
in conjunction with a typical flex-beam helicopter rotor
assembly.
[0043] It is apparent that there has been provided, in accordance
with the assemblies, mechanisms, and methods of the present
invention, a fluid-elastomeric damper assembly including an
internal pumping mechanism. Although the assemblies, mechanisms,
and methods of the present invention have been described with
reference to preferred embodiments and examples thereof, other
embodiments and examples may perform similar functions and/or
achieve similar results. All such equivalent embodiments and
examples are within the spirit and scope of the present invention
and are intended to be covered by the following claims.
* * * * *