U.S. patent application number 13/716796 was filed with the patent office on 2013-06-27 for anti-vibration mount.
This patent application is currently assigned to ROLLS-ROYCE PLC. The applicant listed for this patent is Rolls-Royce PLC. Invention is credited to Paul BROUGHTON, Robin Charles KENNEA, Dariusz Robert MASZCZK, Richard PEACE, Gary Alan SKINNER.
Application Number | 20130160464 13/716796 |
Document ID | / |
Family ID | 46003249 |
Filed Date | 2013-06-27 |
United States Patent
Application |
20130160464 |
Kind Code |
A1 |
MASZCZK; Dariusz Robert ; et
al. |
June 27, 2013 |
ANTI-VIBRATION MOUNT
Abstract
An anti-vibration mount is provided for mounting a first
component to a second component. The mount has an elastomeric body
which provides a recess into which the first component is received.
The mount further has pair of brackets which fit to opposing sides
of the elastomeric body sandwiching the first component received in
the recess therebetween. At least one of the brackets is arranged
to connect the anti-vibration mount and second component together.
The mount further has a clamping arrangement which applies clamping
pressure across the brackets and thereby compresses the elastomeric
body to secure the first component in the recess.
Inventors: |
MASZCZK; Dariusz Robert;
(Derby, GB) ; BROUGHTON; Paul; (Leicester, GB)
; PEACE; Richard; (Derby, GB) ; SKINNER; Gary
Alan; (Nottingham, GB) ; KENNEA; Robin Charles;
(Nottingham, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rolls-Royce PLC; |
London |
|
GB |
|
|
Assignee: |
ROLLS-ROYCE PLC
London
GB
|
Family ID: |
46003249 |
Appl. No.: |
13/716796 |
Filed: |
December 17, 2012 |
Current U.S.
Class: |
60/796 ; 248/634;
29/428 |
Current CPC
Class: |
Y02T 50/672 20130101;
F02C 7/20 20130101; H05K 1/0393 20130101; F05D 2300/603 20130101;
F16M 13/02 20130101; H05K 7/20 20130101; B60R 16/00 20130101; H01R
12/592 20130101; H02G 1/00 20130101; H02G 3/32 20130101; H05B
1/0236 20130101; B64C 3/34 20130101; F02C 7/32 20130101; H01R 12/00
20130101; B64D 29/08 20130101; H05K 2201/029 20130101; B60R 16/02
20130101; H01R 12/515 20130101; Y10T 29/49002 20150115; B60R
16/0215 20130101; H01R 12/59 20130101; F02C 7/224 20130101; F02C
7/12 20130101; F02C 7/141 20130101; F24H 1/105 20130101; F05D
2260/30 20130101; H01R 12/61 20130101; F02C 7/16 20130101; H05B
3/28 20130101; Y10T 29/49117 20150115; B60R 16/08 20130101; Y02T
50/60 20130101; Y10T 29/49234 20150115; Y10T 29/49236 20150115;
H02G 3/0487 20130101; H01R 12/57 20130101; H02G 3/00 20130101; H02G
3/02 20130101; H02G 3/04 20130101; Y10T 29/49238 20150115; Y10T
156/10 20150115; F02C 7/047 20130101; B23P 6/005 20130101; B60R
16/0207 20130101; F02C 7/00 20130101; H01R 12/51 20130101 |
Class at
Publication: |
60/796 ; 248/634;
29/428 |
International
Class: |
F02C 7/20 20060101
F02C007/20; F16M 13/02 20060101 F16M013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2011 |
GB |
122143.9 |
Dec 22, 2011 |
GB |
1122140.5 |
Mar 7, 2012 |
GB |
1203991.3 |
Oct 2, 2012 |
GB |
1217566.7 |
Claims
1. An anti-vibration mount for mounting a first component to a
second component, the mount having: an elastomeric body which
provides a recess into which the first component is received; a
pair of brackets which fit to opposing sides of the elastomeric
body sandwiching the first component received in the recess
therebetween, at least one of the brackets being arranged to
connect the anti-vibration mount and second component together; and
a clamping arrangement which applies clamping pressure across the
brackets and thereby compresses the elastomeric body to secure the
first component in the recess.
2. An anti-vibration mount according to claim 1, wherein the
elastomeric body is in two parts which are separable from each
other when the clamping pressure is removed, the first part
providing one of the opposing sides of the elastomeric body and one
side of the recess and the second part providing the other opposing
side of the elastomeric body and an opposing side of the
recess.
3. An anti-vibration mount according to claim 2, wherein the first
component has a through-hole and the first part has a projection
which extends through the through-hole and is received in a
matching cavity formed in the second part.
4. An anti-vibration mount according to claim 1, wherein the first
component is planar and the recess is a slot.
5. An anti-vibration mount according to claim 1, wherein the first
and the second components are gas turbine engine components.
6. An anti-vibration mount according to claim 1, wherein the first
component is a rigid raft assembly.
7. An anti-vibration mount according to claim 5, wherein the first
component is an engine control unit.
8. A gas turbine engine or gas turbine engine installation having a
first component mounted to a second component by an anti-vibration
mount according to claim 1, the first and second components being
gas turbine engine components.
9. A gas turbine engine or gas turbine engine installation having a
first component mounted to a second component by an anti-vibration
mount according to claim 2, the first and second components being
gas turbine engine components.
10. A gas turbine engine or gas turbine engine installation
according to claim 8, wherein the first component comprises an
electrical raft having electrical conductors embedded in a rigid
material.
11. A gas turbine engine or gas turbine engine installation
according to claim 10, wherein the rigid material is a rigid
composite material.
12. A gas turbine engine or gas turbine engine installation
according to claim 10, wherein the electrical raft is part of an
electrical raft assembly that has a further engine component
mounted thereon.
13. A gas turbine engine or gas turbine engine installation
according to claim 10, wherein: the electrical raft is part of an
electrical system of the gas turbine engine; and the electrical
system further comprises a flexible cable electrically connected
between the electrical raft and another component of the electrical
system.
14. A method for mounting the first component to the second
component, wherein the first component is mounted to the second
component by the anti-vibration mount according to claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from British Patent Application Number 1122140.5 filed 22
Dec. 2011, British Patent Application Number 1122143.9 filed 22
Dec. 2011, British Patent Application Number 1203991.3 filed 7 Mar.
2012 and British Patent Application Number 1217566.7 filed 7 Oct.
2012, the entire contents of which are incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an anti-vibration
mount.
[0004] 2. Background of the Invention
[0005] A typical gas turbine engine has a substantial number of
electrical components which serve, for example, to sense operating
parameters of the engine and/or to control actuators which operate
devices in the engine. Such devices may, for example, control fuel
flow, variable vanes and air bleed valves. The actuators may
themselves be electrically powered, although some may be
pneumatically or hydraulically powered, but controlled by
electrical signals.
[0006] Electrical power, and signals to and from the individual
electrical components, is commonly transmitted along conductors.
Conventionally, such conductors may be in the form of wires and/or
cables which are assembled together in a harness. In such a
conventional harness, each wire may be surrounded by an insulating
sleeve, which may be braided or have a braided cover.
[0007] By way of example, FIG. 1 of the accompanying drawings shows
a typical gas turbine engine including two conventional wiring
harnesses 102, 104, each provided with a respective connector
component 106, 108 for connection to circuitry, which may be for
example accommodated within the airframe of an aircraft in which
the engine is installed.
[0008] The harnesses 102, 104 are assembled from individual wires
and cables which are held together over at least part of their
lengths by suitable sleeving and/or braiding. Individual wires and
cables, for example those indicated at 110, emerge from the
sleeving or braiding to terminate at plug or socket connector
components 112 for cooperation with complementary socket or plug
connector components 114 on, or connected to, the respective
electrical components.
[0009] Each conventional harness 102, 104 comprises a multitude of
insulated wires and cables. This makes the conventional harness
itself bulky, heavy and difficult to manipulate. The conventional
harnesses occupy significant space within a gas turbine engine (for
example within the nacelle of a gas turbine engine), and thus may
compromise the design of the aircraft, for example the size and/or
weight and/or shape of the nacelle.
[0010] Conventional harnesses comprise a large number of
components, including various individual wires and/or bundles of
wires, supporting components (such as brackets or cables) and
electrical and/or mechanical connectors. This can make the assembly
process complicated (and thus susceptible to errors) and/or time
consuming. Disassembly of the conventional harnesses (for example
removal of the conventional harnesses from a gas turbine engine
during maintenance) may also be complicated and/or time consuming.
Thus, in many maintenance (or repair or overhaul) procedures on a
gas turbine engine, removal and subsequent refitting of the
conventional electrical harness may account for a very significant
portion of the operation time and/or account for a significant
proportion of the potential assembly errors.
[0011] The electrical conductors in the conventional harnesses may
be susceptible to mechanical damage. For example, mechanical damage
may occur during installation (for example through accidental
piercing of the protective sleeves/braiding) and/or during service
(for example due to vibration). In order to reduce the likelihood
of damage to the conductors in a conventional harness, the
protective sleeves/braiding may need to be further reinforced,
adding still further weight and reducing the ease with which they
can be manipulated. Similarly, the exposed electrical connectors
used to connect one conductor to another conductor or conductors to
electrical units may be susceptible to damage and/or may add
significant weight to the engine.
[0012] More generally, to reduce or avoid mechanical damage due to
vibration, it is common to mount components to the engine using
anti-vibration mounts. FIG. 2 shows schematically such a mount,
which may be used, for example, to mount an engine control unit
(ECU) such as an electronic engine control (EEC) or an engine
health monitoring unit (EMU) to an engine. The mount has a first
metal plate 116 and a second metal plate 118. Spacing the two
plates is a bowl-shaped elastomeric body 120. The first metal plate
is connected to the ECU via a bolt that passes through the centre
of the first plate and through a fixing hole formed in the ECU
casing, and the second metal plate is connected to the engine via
further bolts at corners of the second plate. The elastomeric body
allows relative movement of the plates and hence attenuates
vibration between the engine and the ECU. An internal tube (not
shown) may be present to prevent forces transmitted between the
first and second plates from crushing the elastomeric body.
[0013] To produce the mount, the metal plates 116, 118 and tube (if
fitted) are chemically bonded to the elastomeric body 120 to
prevent the mount from falling apart before and during assembly. In
some mounts, the chemical bond is required to prevent the
elastomeric body from shifting in normal operation.
OBJECTS AND SUMMARY OF THE INVENTION
[0014] It would be desirable to provide a mount which is simpler to
produce, and which can avoid possible sources of manufacturing
error.
[0015] Accordingly, in a first aspect, the present invention
provides an anti-vibration mount for mounting a first component to
a second component, the mount having: [0016] an elastomeric body
which provides a recess into which the first component is received;
[0017] a pair of brackets which fit to opposing sides of the
elastomeric body sandwiching the first component received in the
recess therebetween, at least one of the brackets being arranged to
connect the anti-vibration mount and second component together (for
example, at least one of the brackets may be joinable to the second
component); and [0018] a clamping arrangement which applies
clamping pressure across the brackets and thereby compresses the
elastomeric body to secure the first component in the recess.
[0019] By providing a recess in the elastomeric body into which the
first component is received and secured, chemical bonding of the
brackets to the elastomeric body may be avoided, which can simplify
production and avoid sources of manufacturing error. The mount can
reduce (or substantially eliminate) the amount (for example the
amplitude and/or the number/range of frequencies) of vibration
being passed from the second component to the first component.
[0020] The mount may have any one or, to the extent that they are
compatible, any combination of the following optional features.
[0021] The elastomeric body can be in two parts which are separable
from each other when the clamping pressure is removed, the first
part providing one of the opposing sides of the elastomeric body
and one side of the recess and the second part providing the other
opposing side of the elastomeric body and an opposing side of the
recess. By using a two part body instead of a one piece body,
mounting of the first component can be considerably simplified as
the two parts can be brought together from opposite sides of the
first component to form the recess in which the first component is
received.
[0022] The first component may have a through-hole which locates in
the recess. The first part of the elastomeric body may have a
projection which extends through the through-hole and is received
in a matching cavity formed in the second part. Such an arrangement
allows the two parts of the elastomeric body to be engaged loosely
together, with the first component in the recess, before the
brackets are fitted, which facilitates the assembly of the complete
mount. Preferably, therefore, the projection is a frictional fit in
the cavity.
[0023] The first component may be planar. The recess may then be a
slot.
[0024] The clamping arrangement which applies clamping pressure
across the brackets may be one or more bolts, studs, rivets or
other suitable fasteners. Conveniently, when the first component
has a through-hole which locates in the recess, the fastener(s) can
extend through the through-hole.
[0025] The bracket which is joinable to the second component can
have any suitable formation for perfecting such a joint. For
example, the bracket may have a joining flange or plate containing
one or more holes through which bolts, studs, rivets or other
suitable fasteners can be passed.
[0026] Protective interlayers may be provided in the recess at the
interfaces between the first component and the elastomeric body.
For example, particularly when the first component is formed from
carbon fibre reinforced plastic (CFRP), to avoid rubbing damage
between the elastomeric body (which is typically formed of rubber)
and the CFRP, glass fibre reinforced plastic (GFRP) interlayers may
be located at these interfaces, GFRP being less susceptible to
rubbing damage than CFRP.
[0027] The first and the second components may be gas turbine
engine components. Vibration isolation can be particularly
beneficial for components attached to gas turbine engines.
[0028] The first component may be an engine control unit such as an
electronic engine control or an engine health monitoring unit.
[0029] In another example, the first component may be a rigid raft
assembly, such as an electrical raft or electrical raft assembly in
which electrical conductors are embedded in a rigid material. Use
of the anti-vibration mount may help to prolong the life of the
rigid raft assembly. The electrical raft (or electrical raft
assembly) may be at least a part of an electrical harness for an
engine, for example a gas turbine engine, and thus may be referred
to herein as an electrical harness raft (or electrical harness raft
assembly). The environment of a gas turbine engine during operation
may be particularly severe, with high levels of vibration. Using
the anti-vibration mount to attach an electrical raft/assembly to a
gas turbine engine may help to prolong the life of the electrical
raft. Furthermore, any other components that may be attached to the
electrical raft (as discussed below and elsewhere herein) may also
benefit from being mounted to the gas turbine engine via the
anti-vibration mounts, through being mounted on the electrical
raft. For example, the reduced vibration may help to preserve the
electrical contact between the electrical raft and any electrical
unit connected thereto. As such, any components (such as an
electrical unit mounted to the electrical raft) that would
conventionally be mounted directly to the gas turbine engine and
require at least a degree of vibration isolation may no longer
require their own dedicated anti-vibration mount. Thus, the total
number of anti-vibration mounts that are required to assemble an
engine may be reduced. This may reduce the number of parts required
and/or the time taken to assemble an engine or engine installation
and/or reduce the total assembled weight and/or reduce the
likelihood of errors occurring during assembly.
[0030] Any other components that may be attached to the rigid raft
assembly may also benefit from being mounted to a gas turbine
engine via the anti-vibration mount, through being mounted on the
rigid raft assembly. This may mean that any components that would
conventionally be mounted directly to a gas turbine engine and
require at least a degree of vibration isolation may no longer
require their own dedicated anti-vibration mount. These components
may include, for example, ECUs such as EECs and EMUs. Thus, the
total number of anti-vibration mounts that are required to assemble
an engine may be reduced. This may reduce the number of parts
required and/or the time taken to assemble an engine or engine
installation and/or reduce the total assembled weight and/or reduce
the likelihood of errors occurring during assembly.
[0031] Furthermore, components that are conventionally mounted to
an engine without anti-vibration mounts (for example because of the
weight and/or cost penalty), but which are now mounted to a rigid
raft assembly, may benefit from vibration isolation without any
weight/cost/assembly time penalty. This may reduce the possibility
of damage occurring to such components and/or increase their
service life. Such components may include, for example, ignitor
boxes (used to provide high voltage power to engine ignitors), and
pressure sensors/switches, for example for fluid systems such as
oil, air, fuel, pneumatics and/or hydraulics.
[0032] More generally, the use of one or more electrical raft
assemblies may significantly reduce build time of an engine. For
example, use of electrical raft assemblies may significantly reduce
the part count involved in engine assembly compared with a
conventional harness arrangement. The number and/or complexity of
the operations required to assemble an engine (for example to
assemble/install the electrical system (or network) and/or other
peripheral components, which may be referred to in general as
engine dressing) may be reduced. For example, rather than having to
install/assemble a great number of wires and/or wiring looms
together on the engine installation, it may only be necessary to
attach a relatively small number of electrical rafts/electrical
raft assemblies, which themselves may be straightforward to handle,
position, secure and connect. Thus, use of electrical raft
assemblies in a gas turbine installation may reduce assembly time
and/or reduce the possibility of errors occurring during
assembly.
[0033] Use of electrical raft assemblies may provide significant
advantages during maintenance, such as repair and overhaul. As
discussed above, the electrical rafts may be particularly quick and
straightforward to assemble. The same advantages discussed above in
relation to assembly apply to disassembly/removal from the gas
turbine engine. Thus, any repair/overhaul that requires removal of
at least a part of the electrical harness may be simplified and/or
speeded up through use of electrical rafts as at least a part of
the electrical harness, for example compared with conventional
harnesses. Use of electrical rafts (for example as part of one or
more electrical raft assemblies) may allow maintenance procedures
to be advantageously adapted. For example, some maintenance
procedures may only require access to a certain portion of the gas
turbine engine that only requires a part of the harness to be
removed. It may be difficult and/or time consuming, or not even
possible, to only remove the required part of a conventional
harness from a gas turbine engine. However, it may be relatively
straightforward to only remove the relevant electrical raft, for
example by simply disconnecting it from the engine and any other
electrical rafts/components to which it is connected. Decreasing
maintenance times has the advantage of, for example, reducing
out-of service times (for example off-wing times for engines that
are used on aircraft).
[0034] The build/assembly times may be additionally or
alternatively reduced by pre-assembling and/or pre-testing
individual and/or combinations of electrical rafts and/or
electrical raft assemblies prior to engine assembly. This may allow
the electrical and/or mechanical operation of the electrical rafts
to be proven before installation, thereby reducing/eliminating the
testing required during engine installation.
[0035] Accordingly, there is provided (and aspects of the invention
may be used with/as a part of) a method of servicing a gas turbine
engine, the method comprising: removing a first rigid raft assembly
from the gas turbine engine, the rigid raft assembly incorporating
at least a part of at least one component or system of the gas
turbine engine; and installing a second, pre-prepared, rigid raft
assembly onto the gas turbine engine in place of the first raft
assembly. The first and second rigid raft assemblies may comprise
electrical rafts having electrical conductors embedded in a rigid
material. The electrical conductors may be at least a part of an
electrical system arranged to transfer electrical signals around
the engine, and the first and second rigid raft assemblies may be
electrical harness raft assemblies.
[0036] The electrical rafts/electrical raft assemblies may be a
particularly lightweight solution for transferring electrical
signals around an engine. For example, an electrical raft may be
lighter, for example significantly lighter, than a conventional
harness required to transmit a given number of electrical signals.
A plurality of conductors may be embedded in a single electrical
raft, whereas in a conventional arrangement a large number of
heavy, bulky wires, usually with insulating sleeves, would be
required. The reduced weight may be particularly advantageous, for
example, when used on gas turbine engines on aircraft.
[0037] Electrical rafts may be more easily packaged and/or more
compact, for example than conventional harnesses. Indeed, as
mentioned above, the electrical rafts can be made into a very wide
range of shapes as desired. This may be achieved, for example, by
manufacturing the electrical rafts using a mould conforming to the
desired shape. As such, each electrical raft may be shaped, for
example, to turn through a tighter corner (or smaller bend radius)
than a conventional harness. The electrical rafts may thus provide
a particularly compact solution for transferring electrical signals
around a gas turbine engine. The electrical rafts may be readily
shaped to conform to neighbouring components/regions of a gas
turbine engine, for example components/regions to which the
particular electrical raft assembly is attached, such as a fan
casing or a core casing.
[0038] The electrical raft(s) may provide improved protection to
the electrical conductors during manufacture/assembly of the
raft/gas turbine installation, and/or during
service/operation/maintenance of the gas turbine engine. This may
result in lower maintenance costs, for example due to fewer damaged
components requiring replacement/repair and/or due to the
possibility of extending time intervals (or service intervals)
between inspecting the electrical system, for example compared with
a system using only conventional harnesses.
[0039] Any suitable material may be used for the rigid material of
the raft. For example, the rigid material may be a rigid composite
material, for example an organic matrix composite. Such a rigid
composite material may be particularly stiff and/or lightweight.
Thus, a rigid composite raft may be used that has suitable
mechanical properties, whilst being thin and lightweight, for
example compared with some other materials. The rigid composite
material may comprise any suitable combination of resin and fibre
as desired for a particular application. For example, any of the
resins and/or fibres described herein may be used to produce a
rigid composite material for the electrical raft. Any suitable
fibres may be used, for example carbon fibres, glass fibres, aramid
fibres, and/or para-aramid fibres. The fibres may be of any type,
such as woven and/or chopped. Any suitable resin may be used, for
example epoxy, BMI (bismaleimide), PEEK (polyetheretherketone),
PTFE (polytetraflouroethylene), PAEK (polyaryletherketone),
polyurethane, and/or polyamides (such as nylon).
[0040] In any example of electrical raft or electrical raft
assembly, at least one of the electrical conductors embedded in the
electrical raft may be an electrically conductive wire. The or each
electrically conductive wire may be surrounded by an electrically
insulating sleeve.
[0041] At least some (for example a plurality) of the electrical
conductors may be provided in a flexible printed circuit (FPC).
Thus, at least some of the electrical conductors may be provided as
electrically conductive tracks in a flexible substrate. The
flexible printed circuit may be flexible before being embedded in
the rigid material.
[0042] Providing the electrical conductors as tracks in a flexible
printed circuit may allow the size of the resulting electrical raft
to be reduced further and/or substantially minimized. For example,
many different electrical conductors may be laid into a flexible
printed circuit in close proximity, thereby providing a compact
structure. The flexible substrate of a single flexible printed
circuit may provide electrical and/or mechanical
protection/isolation to a large number of electrical
conductors.
[0043] Any given electrical raft may be provided with one or more
electrical wires embedded therein (which may be sheathed) and/or
one or more flexible printed circuits embedded therein. As such, a
given electrical raft may have wires and flexible printed circuits
laid therein.
[0044] It will be appreciated that the embedded electrical
conductors (whether they are provided as embedded electrical wires
or as conductive tracks in a flexible printed circuit embedded in
the rigid material) may be described as being fixed in position by
the rigid material, for example relative to the rest of the
electrical harness raft. It will also be appreciated that the
embedded electrical conductors may be said to be surrounded by the
rigid material and/or buried in the rigid material and/or integral
with (or integrated into) the rigid material.
[0045] An electrical raft (or electrical raft assembly) may
comprise a fluid passage. Such a fluid passage may be embedded
therein and/or otherwise provided thereto. The fluid passage may be
part of a fluid system, such as a gas (for example pneumatic or
cooling gas/air) and/or liquid (for example a fuel, hydraulic
and/or lubricant liquid).
[0046] Accordingly, there is provided (and aspects of the invention
may be used with/as a part of) a rigid raft assembly for a gas
turbine engine, the rigid raft assembly comprising a rigid material
that carries at least a part of a first gas turbine engine system
and at least a part of a second gas turbine engine system, wherein:
the first gas turbine engine system is a fluid system that
comprises at least one fluid passage that is at least partially
embedded in the rigid raft assembly. The second gas turbine engine
system may be an electrical system that comprises electrical
conductors at least partially embedded in the rigid material.
[0047] The electrical raft may comprise one or more electrical
connectors or sockets, which may be electrically connected to at
least one of the embedded electrical conductors. The electrical
connector or socket may allow electrical connection of the
electrical raft to other electrical components, for example to
other electrical rafts (either directly or indirectly, via an
electrical cable or lead) or to electrical units (again, either
directly or indirectly, via an electrical cable or lead). Such an
electrical connector or socket may take any suitable form, and may
be at least partially embedded in the rigid electrical raft.
[0048] The electrical raft (or electrical raft assembly) assembly
may be a first engine installation component, and the gas turbine
engine may further comprise a second engine installation component
having electrical conductors. The first and second engine
installation components may be part of an electrical system
arranged to transfer electrical signals around the engine
installation. The gas turbine engine may further comprise at least
one flexible cable connected between the electrical raft assembly
and the second engine installation component (which itself may be
or comprise an electrical raft) so as to electrically connect
electrical conductors of the electrical raft assembly with
electrical conductors of the second engine installation
component.
[0049] The second engine installation component may be, for
example, an ECU, such as an EMU or EEC. Additionally or
alternatively, the second engine installation component may be a
further electrical raft or electrical raft assembly.
[0050] The environment of a gas turbine engine during operation may
be particularly severe, with, for example, high levels of vibration
and/or differential expansion between components as the temperature
changes through operation and as the components move relative to
each other. Providing at least one flexible cable to connect an
electrical raft assembly to another component may allow the
electrical rafts and/or components to accommodate vibration and/or
relative movement, for example of the component(s)/assemblies to
which they are attached/mounted during use. For example, the
flexible cable(s) (where present) used to electrically connect
electrical raft assemblies to other component(s) may have
sufficient length to accommodate such vibration and/or movement
during use.
[0051] For example, providing separate (for example more than one)
electrical raft assemblies and connecting at least some (for
example at least two) of them together using at least one flexible
cable may allow the electrical rafts to accommodate vibration
and/or relative movement of the component(s)/assemblies to which
they are attached/mounted during use.
[0052] The electrical signals transferred by the conductors in the
electrical raft, and around the engine using the electrical
rafts/raft assemblies may take any form. For example, the
electrical signals may include, by way of non-limitative example,
electrical power and/or electrical control/communication signals
and/or any other type of transmission through an electrical
conductor. Transmission of signals around the engine may mean
transmission of signals between (to and/or from) any number of
components/systems in the engine and/or components/system of a
structure (such as an airframe) to which the gas turbine engine is
(or is configured to be) connected/installed in. In other words, an
electrical raft may be used to transfer/communicate any possible
combination of electrical signals in any part of a gas turbine
engine installation or a related (for example electrically and/or
mechanically connected) structure/component/system.
[0053] An electrical raft or raft assembly may be provided in any
suitable location/position of the gas turbine engine, for example
to a mounting structure at any suitable location. For example, the
gas turbine engine may comprise a bypass flow duct formed between
an engine core and an engine fan casing (the gas turbine engine may
be a turbofan engine, for example); and the electrical raft
assembly may form at least a part of a radially extending splitter
(which may be referred to as a bifurcation) that extends across the
bypass flow duct. In this way, an electrical raft (which may be
referred to as a splitter electrical raft) may provide an
electrical connection between a fan casing and an engine core. By
way of further example, the electrical raft assembly may be
attached to the engine core case or engine fan case, for example to
a mounting structure on such cases.
[0054] An electrical raft may be provided with at least one mount
on which other components (for example auxiliary/ancillary
components/systems) of the gas turbine engine are (or may be)
mounted. The mount may be a bracket, for example a bespoke bracket
for the component/system mounted thereon or a conventional/standard
bracket. The electrical raft may provide a stable, regular and
convenient platform on which to mount the various
systems/components. The combination of the installed electrical
raft assembly with components/systems mounted thereon may be much
more compact and/or straightforward to assemble and/or have a
greatly reduced number of component parts, for example compared
with the corresponding conventional electrical harness and
separately mounted components/systems.
[0055] The mounts may be used to attach any component/system to an
electrical raft (and thus to the engine) as required. For example,
fluid pipes for transferring fluid around the engine may be mounted
to the electrical rafts (for example mechanically mounted using a
bracket), and thus to the engine. More than one set of fluid pipes,
for example for carrying different or the same fluids, may be
mounted on the same electrical raft.
[0056] In a second aspect, the present invention provides a gas
turbine engine or gas turbine engine installation (for example for
an airframe) having a first component mounted to a second component
by an anti-vibration mount according to the first aspect.
[0057] The gas turbine engine or gas turbine engine installation
may have any one or, to the extent that they are compatible, any
combination of the following optional features.
[0058] The first component may comprise an electrical raft having
electrical conductors embedded in a rigid material. The rigid
material may be a rigid composite material.
[0059] Such an electrical raft may be part of an electrical raft
assembly that has a further engine component mounted thereon, as
described elsewhere herein by way of example.
[0060] Such an electrical raft may be part of an electrical system
of the gas turbine engine or installation. The electrical system
may comprise at least one other component, for example at least one
other electrical raft or electrical raft assembly. The electrical
system further may further comprise a flexible cable electrically
connected between the electrical raft and another component of the
electrical system.
[0061] In a third aspect, the present invention provides the use of
an anti-vibration mount according to the first aspect for mounting
the first component to the second component.
[0062] Further optional features of the invention are set out
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] Embodiments of the invention will now be described by way of
example with reference to the accompanying drawings in which:
[0064] FIG. 1 shows a gas turbine engine with a conventional
harness;
[0065] FIG. 2 shows a conventional anti-vibration mount;
[0066] FIG. 3 shows a cross-section through a gas turbine engine
having anti-vibration mounts in accordance with the present
invention;
[0067] FIG. 4 shows a perspective view of a flexible printed
circuit;
[0068] FIG. 5 shows a side view of the flexible printed circuit of
FIG. 4;
[0069] FIG. 6 shows a schematic of an electrical raft prior to
assembly;
[0070] FIG. 7 shows a cross-section normal to the axial direction
through a gas turbine engine having anti-vibration mounts in
accordance with the present invention; and
[0071] FIG. 8 shows (a) a plan view of an anti-vibration mount in
accordance with the present invention, and (b) a cross-section
along line Y-Y through the mount.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0072] With reference to FIG. 3, a ducted fan gas turbine engine
generally indicated at 10 has a principal and rotational axis X-X.
The engine 10 comprises, in axial flow series, an air intake 11, a
propulsive fan 12, an intermediate pressure compressor 13, a
high-pressure compressor 14, combustion equipment 15, a
high-pressure turbine 16, and intermediate pressure turbine 17, a
low-pressure turbine 18 and a core engine exhaust nozzle 19. The
engine also has a bypass duct 22 and a bypass exhaust nozzle
23.
[0073] The gas turbine engine 10 works in a conventional manner so
that air entering the intake 11 is accelerated by the fan 12 to
produce two air flows: a first air flow A into the intermediate
pressure compressor 13 and a second air flow B which passes through
the bypass duct 22 to provide propulsive thrust. The intermediate
pressure compressor 13 compresses the air flow A directed into it
before delivering that air to the high pressure compressor 14 where
further compression takes place.
[0074] The compressed air exhausted from the high-pressure
compressor 14 is directed into the combustion equipment 15 where it
is mixed with fuel and the mixture combusted. The resultant hot
combustion products then expand through, and thereby drive the
high, intermediate and low-pressure turbines 16, 17, 18 before
being exhausted through the nozzle 19 to provide additional
propulsive thrust. The high, intermediate and low-pressure turbines
16, 17, 18 respectively drive the high and intermediate pressure
compressors 14, 13 and the fan 12 by suitable interconnecting
shafts.
[0075] The gas turbine engine 10 shown in FIG. 3 shows two
electrical raft assemblies 600 mounted to the engine with
anti-vibration mounts (discussed below with reference to FIG. 8).
As such, the gas turbine engine 10 is in accordance with the
present invention. Each electrical raft assembly 600 comprises an
electrical raft 200. The electrical rafts 200 may be used to
transmit/transfer electrical signals (or electricity, including
electrical power and/or electrical control signals) around the
engine and/or to/from the engine 10 from other components, such as
components of an airframe. The function and/or construction of each
electrical raft 200 and electrical raft assembly 600 may be as
described above and elsewhere herein.
[0076] In FIG. 3, each electrical raft 200 (which may be referred
to herein simply as a raft 200 or an electrical harness raft 200)
comprises at least one electrical conductor 252 embedded in a rigid
material 220, which may be a rigid composite material.
[0077] The electrical conductors 252 in the electrical raft 200 may
be provided in a harness 250, which may be a flexible printed
circuit board (or FPC) 250.
[0078] An example of an FPC 250 in which the electrical conductors
252 may be provided is shown in greater detail in FIGS. 4 and 5.
FIG. 4 shows a perspective view of the FPC 250, and FIG. 5 shows a
side view.
[0079] Such an FPC 250 may comprise a flexible (for example
elastically deformable) substrate 255 with conductive tracks 252
laid/formed therein. The FPC 250 may thus be deformable. The FPC
250 may be described as a thin, elongate member and/or as a
sheet-like member. Such a thin, elongate member may have a major
surface defined by a length and a width, and a thickness normal to
the major surface. In the example shown in FIGS. 4 and 5, the FPC
250 may extend along a length in the x-direction, a width in the
y-direction, and a thickness (or depth or height) in the
z-direction. The x-direction may be defined as the axial direction
of the FPC. Thus, the x-direction (and thus the z-direction) may
change along the length of the FPC 250 as the FPC is deformed. This
is illustrated in FIG. 5. The x-y surface(s) (i.e. the surfaces
formed by the x and y directions) may be said to be the major
surface(s) of the FPC 250. In the example shown in FIGS. 4 and 5,
the FPC 250 is deformable at least in the z direction, i.e. in a
direction perpendicular to the major surface. FPCs may be
additionally of alternatively deformable about any other direction,
and/or may be twisted about any one or more of the x, y, or z
directions.
[0080] The flexible substrate 255 may be a dielectric. The
substrate material may be, by way of example only, polyamide. As
will be readily apparent, other suitable substrate material could
alternatively be used.
[0081] The conductive tracks 252, which may be surrounded by the
substrate 255, may be formed using any suitable conductive
material, such as, by way of example only, copper, copper alloy,
tin-plated copper (or tin-plated copper alloy), silver-plated
copper (or silver-plated copper alloy), nickel-plated copper (or
nickel-plated copper alloy) although other materials could
alternatively be used. The conductive tracks 252 may be used to
conduct/transfer electrical signals (including electrical power and
electrical control signals) through the rigid raft assembly (or
assemblies) 200, for example around a gas turbine engine 10 and/or
to/from components of a gas turbine engine and/or an airframe
attached to a gas turbine engine.
[0082] The size (for example the cross-sectional area) and/or the
shape of the conductive tracks 252 may depend on the signal(s) to
be transmitted through the particular conductive track 252. Thus,
the shape and/or size of the individual conductive tracks 252 may
or may not be uniform in a FPC 250.
[0083] The example shown in FIGS. 4 and 5 has six conductive tracks
252 running through the substrate 255. However, the number of
conductive tracks 252 running through a substrate 255 could be
fewer than six, or greater than six, for example tens or hundreds
of tracks, as required. As such, many electrical signals and/or
power transmission lines may be incorporated into a single FPC
250.
[0084] A single FPC 250 may comprise one layer of tracks, or more
than one layer of tracks, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10
or more than 10 layers of tracks. An FPC may comprise significantly
more than 10 layers of tracks, for example at least an order of
magnitude more layers of tracks. In this regard, a layer of tracks
may be defined as being a series of tracks that extend in the same
x-y surface. Thus, the example shown in FIGS. 4 and 5 comprises 2
layers of tracks, with each layer comprising 3 tracks 252.
[0085] An electrical raft 200 may be manufactured using any
suitable method. For example, the rigid material 220 may initially
be provided as layers of flexible material, such as (by way of
example only) layers of fibre and resin compound. This flexible
material may be placed into a mould, for example having a desired
shape. Other components (such as fluid pipes 210 and/or the
electrical conductors 252, which may be embedded in a FPC 250) may
also be placed into the mould, for example between layers of the
flexible material from which the rigid material 220 is ultimately
formed. Parts of the mould may have any suitable form and/or
construction, for example that could be readily removed when the
electrical raft 200 is formed into the desired shape.
[0086] FIG. 6 shows components of an example of an electrical raft
200 prior to one method of construction. The electrical conductors
252 are provided between two layers of material 230, 240 that,
after construction, form the rigid material 220. Some of the
electrical conductors 252 are provided in an FPC 250. The material
230, 240 may be a fibre and resin compound, as described elsewhere
herein. Such a fibre and resin compound may, after suitable
treatment (for example heat treatment), produce the rigid composite
material 220. In the example of FIG. 6, the fibre and resin
compound is formed of a sheet of interwoven fibres, or strands. The
strands in FIG. 6 extend in perpendicular directions, although the
strands may extend in any one or more directions as required. The
strands/fibres may be pre-impregnated (or "pre-pregged") with the
resin.
[0087] Prior to any treatment, both the first and second layers
230, 240 and the electrical conductors 252 may be flexible, for
example supple, pliable or malleable. As such, when the layers 230,
240 and the electrical conductors 252 are placed together, they may
be moulded, or formed, into any desired shape. For example, the
layers 230, 240 and the electrical conductors 252 may be placed
into a mould (which may be of any suitable form, such as a glass or
an aluminium mould) having the desired shape. The desired shape may
be, for example, a shape that corresponds to (for example is offset
from) a part of a gas turbine engine, such as, by way of example
only, at least a part of a casing, such as an engine fan casing or
engine core casing. This may enable the final raft to adopt shapes
that are curved in two-dimensions or three-dimensions.
[0088] Any suitable method could be used to produce the electrical
raft 200. For example, the strands/fibres need not be
pre-impregnated with the resin. Instead, the fibres/strands could
be put into position (for example relative to electrical conductors
252/FPC 250) in a dry state, and then the resin could be fed (or
pumped) into the mould. Such a process may be referred to as a
resin transfer method. In some constructions no fibre may be used
at all in the rigid material 220.
[0089] FIG. 7 is a schematic showing a cross-section perpendicular
to the direction X-X of a gas turbine engine comprising electrical
raft assemblies 600A-600G. Any one of the electrical raft assmblies
600A-600G may comprise any or all of the features of an electrical
raft assembly 600 as described above, for example. Thus, for
example, any one of the electrical raft assemblies may comprise an
electrical raft 200 (not labelled for raft assemblies 600E-600G for
simplicity only) having electrical conductors 252 (not labelled in
FIG. 7 for simplicity only) embedded therein. Some or all of the
electrical raft assemblies 600A-600G (which may collectively be
referred to as electrical raft assemblies 600) comprise a mounting
fixture for attaching the respective assembly 600 to a mounting
structure via an anti-vibration mount (discussed below with
reference to FIG. 8) in accordance with the present invention.
[0090] The mounting structure is part of a fan case 24 for
electrical raft assemblies 600A-600D, part of a bifurcation
splitter that radially crosses a bypass duct 22 for electrical raft
assemblies 600E and part of an engine core case 28 for electrical
raft assemblies 600F and 600G. However, it will be appreciated that
an electrical raft assembly 600 could be mounted in any suitable
and/or desired location on a gas turbine engine.
[0091] In FIG. 7, two electrical raft assemblies 600A, 600C are
shown as having an electrical unit 300 mounted on the respective
electrical raft 200. However, any (or none) of the electrical raft
assemblies 600A-600G may have an electrical unit 300 mounted to the
respective electrical raft 200.
[0092] As mentioned herein, each of the electrical rafts 200
associated with the electrical raft assemblies 600A-600G shown in
FIG. 7 comprises one or more electrical conductors 252 embedded
therein. However, any one or more of the electrical rafts 200 may
be replaced with a raft that does not comprise electrical
conductors 252. Such a raft would not be an electrical raft 200,
but may otherwise be as described elsewhere herein, for example it
may be a rigid raft that may have components/systems (such as, by
way of example only, fluid systems, such as pipes) mounted thereon
and/or embedded therein. Thus, for example, a gas turbine engine in
accordance with the present invention may have a combination of
electrical rafts 200 and non-electrical rafts.
[0093] The arrangement of electrical raft assemblies 600A-600G
shown in FIG. 7 is by way of example only. Alternative
arrangements, for example in terms of number, size, shape and/or
positioning, of electrical raft assemblies 600A-600G may be used.
For example, there need not be seven electrical raft assemblies,
the assemblies may or may not be connected together, and the rafts
could be provided to (for example mounted on) any one or more
components of the gas turbine engine. Purely by way of example
only, connection between electrical raft assemblies 600A-600D
mounted on the fan casing 24 to the electrical raft assemblies
600F, 600G mounted on the core casing 28 may be provided at least
in part by means other than an additional electrical raft assembly
600E, for example using wire conductors with insulating sleeves. By
way of further example, one or more electrical raft assemblies 600
may additionally or alternatively be provided to the nose cone,
structural frames or elements within the engine (such as
"A-frames"), the nacelle, the fan cowl doors, and/or any connector
or mount between the gas turbine engine 10 and a connected
structure (which may be at least a part of a structure in which the
gas turbine engine 10 is installed), such as the pylon 500 between
the gas turbine engine 10 and an airframe (not shown).
[0094] Any one or more of the electrical rafts of the electrical
raft assemblies 600A-600G may have a fluid passage 210 embedded
therein and/or provided thereto. The fluid passage 210 may be part
of a fluid system, such as a gas (for example pneumatic or cooling
gas/air) and/or liquid (for example a fuel, hydraulic and/or
lubricant liquid). In the FIG. 7 example, three of the electrical
rafts (of electrical raft assemblies 600A, 600B, 6000) comprise a
fluid passage 210 at least partially embedded therein. The
electrical raft of assembly 6000 also has a fluid passage 285
(which may be for any fluid, such as those listed above in relation
to embedded passage 210) mounted thereon. Such a mounted fluid
passage 285 may be provided to any electrical raft, such as those
of electrical raft assemblies 600A-600G shown in FIG. 7. The fluid
passages 210, 285 shown in FIG. 7 may be oriented in an axial
direction of the engine 10. However, fluid passages may be oriented
in any direction, for example axial, radial, circumferential or a
combination thereof.
[0095] Any of the electrical raft assemblies 600A-600G (or the
respective electrical rafts 200 thereof) may have any combination
of mechanical, electrical and/or fluid connections to one or more
(for example 2, 3, 4, 5 or more than 5) other components/systems of
the gas turbine engine 10 and/or the rest of the gas turbine engine
10. Examples of such connections are shown in FIG. 7, and described
below, but other connectors may be used. For example, electrical
raft assemblies 600 (and/or non-electrical rafts) may be connected
together (or to other components) using any combination of
electrical, fluid and/or mechanical connectors. Thus, any of the
connections 290A/290B, 291-297 shown in FIG. 7 may be any
combination of electrical, fluid and/or mechanical connection.
Alternatively, electrical raft assemblies 600 (and/or
non-electrical rafts) may be standalone, and thus may have no
connection to other rafts or components.
[0096] A connection 291 is shown between the electrical rafts of
the assemblies 600A and 600D. The connection 291 may comprise an
electrical connection. Such an electrical connection may be
flexible and may, for example, take the form of a flexible printed
circuit such as the flexible printed circuit 250 shown in FIGS. 4
and 5. Such a flexible electrical connection may be used to
electrically connect any electrical raft assembly 600 to any other
component, such as another electrical raft assembly 600. A
connection 297 (which may be or comprise an electrical connection)
is provided between the electrical raft of the assembly 600A and a
part of an airframe, or airframe installation 500, which may, for
example, be a pylon. Similarly, a fluid and/or mechanical
connection 296 may additionally or alternatively be provided
between the airframe 500 and another electrical raft of the
assembly 600C. As shown in FIG. 7, other electrical and/or fluid
connections 292, 293, 294, 295 may be provided between electrical
rafts 200 (or assemblies 600) and other components, such as other
electrical rafts 200 (or assemblies 600).
[0097] A direct connection 290A, 290B may be provided, as shown for
example between the electrical rafts of the assemblies 600B and
600C in the FIG. 7 arrangement. Such a direct connection 290A, 290B
may comprise a connector 290A provided on (for example embedded in)
one electrical raft 200 connected to a complimentary connector 290B
provided on (for example embedded in) another electrical raft 200.
Such a direct connection 290A, 290B may, for example, provide fluid
and/or electrical connection between the two electrical rafts
assemblies 600B, 600C.
[0098] Where reference is made herein to a gas turbine engine, it
will be appreciated that this term may include a gas turbine
engine/gas turbine engine installation and optionally any
peripheral components to which the gas turbine engine may be
connected to or interact with and/or any connections/interfaces
with surrounding components, which may include, for example, an
airframe and/or components thereof. Such connections with an
airframe, which are encompassed by the term "gas turbine engine" as
used herein, include, but are not limited to, pylons and mountings
and their respective connections. The gas turbine engine itself may
be any type of gas turbine engine, including, but not limited to, a
turbofan (bypass) gas turbine engine, turbojet, turboprop, ramjet,
scramjet or open rotor gas turbine engine, and for any application,
for example aircraft, industrial, and marine application.
Electrical raft assemblies 600 such as any of those described
and/or claimed herein may be used as part of any apparatus, such as
any vehicle, including land, sea, air and space vehicles, such as
motor vehicles (including cars and busses), trains, boats,
submarines, aircraft (including aeroplanes and helicopters) and
spacecraft (including satellites and launch vehicles).
[0099] It will be appreciated that many alternative configurations
and/or arrangements of electrical raft assemblies 600 and gas
turbine engines 10 comprising electrical raft assemblies 600 other
than those described herein may fall within the scope of the
invention. For example, alternative arrangements of electrical raft
assemblies 600 (for example in terms of the arrangement, including
number/shape/positioning/constructions, of mounting fixtures, the
arrangement/shape/positioning/construction of the electrical rafts
200, the type and/or positioning of components (if any) mounted
to/embedded in the electrical rafts 200, the rigid material 220 and
the electrical conductors 252) may fall within the scope of the
invention and may be readily apparent to the skilled person from
the disclosure provided herein. Alternative arrangements of
connections (for example mechanical, electrical and/or fluid)
between the electrical (or non-electrical) rafts and/or raft
assemblies and between the electrical (or non-electrical) rafts or
raft assemblies and other components may fall within the scope of
the invention and may be readily apparent to the skilled person
from the disclosure provided herein. Furthermore, any feature
described and/or claimed herein may be combined with any other
compatible feature described in relation to the same or another
embodiment.
[0100] FIG. 8 shows (a) a plan view of an anti-vibration mount in
accordance with the present invention, and (b) a cross-section
along line Y-Y through the mount. The mount attaches a mounting
fixture portion 710 of one of the electrical raft assemblies
600A-600G to a respective mounting structure 700 (shown
schematically in FIG. 7) of the engine. The mounting fixture
portion can be a planar region of the raft assembly containing a
though-hole 712. The mounting structure 700 can be a part of the
engine, for example a flange extending from the respective part of
the engine, e.g. the fan casing 24 or core casing 28.
[0101] The anti-vibration mount has an elastomeric (e.g. rubber)
body which is formed in two parts. The first part 714a is
positioned on one side of the planar region 710, with a projection
716 in the centre of the part extending through the through-hole
712. The second part 714b is positioned on the other side of the
planar region 710 with the projection 716 fitting into a matching
cavity 718 formed at the centre of the second part. The first and
second parts thus form a slot-shaped recess 720 in which the planar
region 710 is received.
[0102] The anti-vibration mount also has a pair of, typically
metal, brackets 722a, b which fit to respectively the outer surface
of the first part 714a of the elastomeric body and the outer
surface of the second part 714b of the body to sandwich the part of
the planar region 710 received in the slot 720 therebetween. A
number of bolts 724 (for example four are shown in FIG. 8(a)), or
other suitable fasteners, extend between the brackets through the
through-hole 712 and within matching passages formed in the first
part 714a of the elastomeric body.
[0103] The bolts are tightened to apply a clamping pressure across
the brackets and thereby compress the elastomeric body to secure
the planar region 710 in the slot 720.
[0104] One of the brackets 722a has a joining plate 726 extending
therefrom which is attachable via a bolt 728 to the engine mounting
structure 700.
[0105] The mount is thus rigidly and strongly attached to the
engine while the raft or raft assembly is in turn attached to the
mount in a manner which allows the elastomeric body to reduce (or
substantially eliminate) the amount of vibration being passed from
the engine to the raft assembly.
[0106] To prevent rubbing damage to the raft assembly at the
interfaces between the planar region 710 and the parts 714a, b of
the elastomeric body, interlayers (not shown in FIG. 8(b)) may be
located in the recess 720 at the interfaces of the planar region
and the elastomeric body. For example, these interlayers may be
formed of GFRP.
[0107] Advantageously, the anti-vibration mount does not require
the parts 714a, b of the elastomeric body to be chemically bonded
to the brackets 722a, b. The mount can be straightforwardly
assembled by joining the lower bracket 722a to the engine mounting
structure 700, placing the first part 714a on the lower bracket,
positioning the raft assembly so that the through-hole 712 sits
over the projection 716, fitting the second part 714b onto the
projection, locating the upper bracket 722b, and then fitting and
tightening the bolts 724.
[0108] Optionally, one of the brackets 722a, b may be integral with
the mounting structure 710. Alternatively, both the lower bracket
722a and the upper bracket 722b may be separate from the mounting
structure 710, with at least one of the brackets 722a, b being
connectable to the mounting structure 710.
[0109] While the invention has been described in conjunction with
the exemplary embodiments described above, many equivalent
modifications and variations will be apparent to those skilled in
the art when given this disclosure. For example, although described
above in relation to the mounting of electrical raft assemblies to
a gas turbine engine, the anti-vibration mount can be used to mount
other components, such as electrical control units, to the engine,
or indeed to mount any two components together where vibration
isolation is desirable. Possible fields of application are thus
aerospace, marine or automotive vehicles and machine tools.
Accordingly, the exemplary embodiments of the invention set forth
above are considered to be illustrative and not limiting. Various
changes to the described embodiments may be made without departing
from the spirit and scope of the invention.
* * * * *