U.S. patent application number 14/161860 was filed with the patent office on 2015-10-01 for composite fan containment case assembly.
This patent application is currently assigned to United Technologies Corporation. The applicant listed for this patent is United Technologies Corporation. Invention is credited to Mark W. Costa, Darin S. Lussier, Rajiv A. Naik, Thomas J. Robertson, JR., Sreenivasa R. Voleti.
Application Number | 20150275689 14/161860 |
Document ID | / |
Family ID | 46199568 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150275689 |
Kind Code |
A1 |
Lussier; Darin S. ; et
al. |
October 1, 2015 |
COMPOSITE FAN CONTAINMENT CASE ASSEMBLY
Abstract
A fan case for a gas turbine engine includes a composite fan
containment case that includes an outer surface. The composite fan
containment case includes multiple composite layers that define a
generally cylindrical case. An attachment flange extends radially
outward from the cylindrical case. The attachment flange comprises
a portion of the composite layers. A metallic backing ring is
secured to the attachment flange by rivets.
Inventors: |
Lussier; Darin S.; (Berlin,
CT) ; Robertson, JR.; Thomas J.; (Glastonbury,
CT) ; Costa; Mark W.; (Storrs, CT) ; Voleti;
Sreenivasa R.; (Farmington, CT) ; Naik; Rajiv A.;
(Glastonbury, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
United Technologies Corporation |
Hartford |
CT |
US |
|
|
Assignee: |
United Technologies
Corporation
Hartford
CT
|
Family ID: |
46199568 |
Appl. No.: |
14/161860 |
Filed: |
January 23, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13397771 |
Feb 16, 2012 |
8672609 |
|
|
14161860 |
|
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|
|
12551018 |
Aug 31, 2009 |
8757958 |
|
|
13397771 |
|
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|
|
12636388 |
Dec 11, 2009 |
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|
12551018 |
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|
12892037 |
Sep 28, 2010 |
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|
12636388 |
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|
12912189 |
Oct 26, 2010 |
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12892037 |
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12986209 |
Jan 7, 2011 |
8979473 |
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12912189 |
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13024386 |
Feb 10, 2011 |
8827629 |
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12986209 |
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Current U.S.
Class: |
415/200 |
Current CPC
Class: |
F05D 2300/603 20130101;
F02K 3/06 20130101; F05D 2230/50 20130101; F01D 25/243 20130101;
Y02T 50/672 20130101; F01D 21/045 20130101; Y02T 50/60 20130101;
F05D 2240/14 20130101; F01D 25/005 20130101 |
International
Class: |
F01D 25/00 20060101
F01D025/00; F02K 3/06 20060101 F02K003/06; F01D 25/24 20060101
F01D025/24 |
Claims
1. A fan case for a gas turbine engine comprising: a composite fan
containment case including an outer surface, the composite fan
containment case includes multiple composite layers defining a
generally cylindrical case, an attachment flange extending radially
outward from the cylindrical case, the attachment flange comprising
a portion of the composite layers, and a metallic backing ring
secured to the attachment flange by rivets.
2. A fan case for a gas turbine engine comprising: a composite fan
containment case including an outer surface, a front and a rear; an
attachment flange and a mounting ring respectively provided on the
front and the rear, the mounting ring is metallic and is secured to
the outer surface at the rear, the mounting ring includes a
failsafe lug and primary lugs extending radially outward and
circumferentially spaced from one another, the lugs configured to
secure to an engine mount beam connected to a pylon; and fan exit
guide vanes secured to the composite fan containment case by
fasteners arranged on either axial side of the primary lugs.
3. The fan case according to claim 1, wherein the rivets include
heads that do not protrude from the metallic backing ring.
4. The fan case according to claim 1, wherein the attachment flange
and metallic backing ring respectively include a first and second
sides, and each rivet includes first and second heads respectively
engaging the first and second sides and clamping the metallic
backing ring to the attachment flange.
5. The fan case according to claim 4, wherein the first head does
not protrude from the first side.
6. The fan case according to claim 5, wherein the first head is
flush with the first side.
7. The fan case according to claim 4, wherein the second head does
not protrude from the second side.
Description
[0001] This disclosure is a continuation of U.S. patent application
Ser. No. 13/397,771 filed Feb. 16, 2012, which is a
continuation-in-part of U.S. patent application Ser. Nos.
12/551,018 filed Aug. 31, 2009; 12/636,388 filed Dec. 11, 2009;
12/892,037 filed Sep. 28, 2010; 12/912,189 filed Oct. 26, 2010;
12/986,209 filed Jan. 7, 2011; and 13/024,386 filed Feb. 10,
2011.
BACKGROUND
[0002] This disclosure pertains to a composite fan containment case
for a gas turbine engine.
[0003] A gas turbine engine may include a fan section containing
fan blades that are surrounded by a fan case supported within a
nacelle. The function of the fan case is to contain fractured and
separated parts of the fan blades in a radial direction. Metallic
fan cases can be undesirably heavy to perform this containment
function. A composite fan case constructed of non-metallic
materials can reduce weight and provide the same containment
capability as a metallic fan case.
[0004] While these fan cases have many desirable characteristics,
one challenge is the components must be attached to the outer
periphery of the case, typically through threaded fasteners.
However, the material utilized to form the fan case has not been
accommodating of bolt holes. Moreover, composite material
manufacturing and forming techniques are limited in the range of
tolerances that can be reliably obtained.
SUMMARY
[0005] In one exemplary embodiment, a fan case for a gas turbine
engine includes
a composite fan containment case that includes an outer surface.
The composite fan containment case includes multiple composite
layers that define a generally cylindrical case. An attachment
flange extends radially outward from the cylindrical case. The
attachment flange comprises a portion of the composite layers. A
metallic backing ring is secured to the attachment flange by
rivets.
[0006] In another exemplary embodiment, a fan case for a gas
turbine engine includes a composite fan containment case that
includes an outer surface, a front and a rear, an attachment flange
and a mounting ring respectively provided on the front and the
rear. The mounting ring is metallic and is secured to the outer
surface at the rear. The mounting ring includes a failsafe lug and
primary lugs extending radially outward and circumferentially
spaced from one another. The lugs are configured to secure to an
engine mount beam connected to a pylon. Fan exit guide vanes are
secured to the composite fan containment case by fasteners that are
arranged on either axial side of the primary lugs.
[0007] In a further embodiment of any of the above, the rivets
include heads that do not protrude from the metallic backing
ring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The disclosure can be further understood by reference to the
following detailed description when considered in connection with
the accompanying drawings wherein:
[0009] FIG. 1 is a schematic view of an example gas turbine
engine.
[0010] FIG. 2 is a cross-sectional view through the containment
case shown in FIG. 3 taken along line 2-2.
[0011] FIG. 3 is a perspective view of an example containment
case.
[0012] FIG. 4 is an enlarged cross-sectional view of the
containment case and mount ring.
[0013] FIG. 5 is a cross-sectional view of another example
containment case and mount ring.
[0014] FIG. 6 is a perspective view of a component supported by a
containment case attachment.
[0015] FIG. 7 is an enlarged perspective view of the attachment
shown in FIG. 6.
[0016] FIG. 8 is a cross-sectional view of the attachment shown in
FIG. 7 taken along line 8-8.
[0017] FIG. 9 is a cross-sectional view of a containment case
attachment flange through a fastening element.
[0018] FIG. 10 is a cross-sectional view of the containment case
attachment flange shown in FIG. 9, but through an attaching
hole.
[0019] FIG. 11 is an enlarged cross-sectional view of blade
containment feature of the containment case.
DETAILED DESCRIPTION
[0020] Referring to FIG. 1, a gas turbine engine is schematically
indicated at 10 and includes a core 12 having a compressor section
14, a combustion section 16 and a turbine section 18. The example
gas turbine engine 10 includes a fan section 20 that is disposed
within a nacelle 22 and includes a plurality of blades 28. The
compressor, combustion, turbine, and fan sections 14, 16, 18 and 20
are arranged about an axis A. The nacelle 22 defines an inlet 24
for incoming airflow. A fan containment case 26 is disposed
proximate to the blades 28 within the fan section 20.
[0021] Referring to FIGS. 2 and 3, the example fan containment case
26 includes attachment features and containment features for a
composite containment structure. A mounting ring 32 is provided at
the rear 33 of the fan containment case 26, and an attachment
flange 62 is provided at its front 31, for securing the fan
containment case 26 relative to other engine structure. Bolt
attachments 72 are provided on the fan containment case 26 for
supporting components on the fan containment case 26. The
containment features include a composite containment shell 112 and
a ballistic liner 152. These attachment and containment features
are fully set forth in patent applications to which this disclosure
claims priority, and Applicant hereby incorporates by reference the
entirety of U.S. patent application Ser. Nos. 12/551,018 filed Aug.
31, 2009; 12/636,388 filed Dec. 11, 2009; 12/892,037 filed Sep. 28,
2010; 12/912,189 filed Oct. 26, 2010; 12/986,209 filed Jan. 7,
2011; and 13/024,386 filed Feb. 10, 2011.
[0022] Returning to FIG. 1, the example containment case includes
the mount ring 32 attached to a mount beam 36 attached to a frame
member such as a pylon 44 of an aircraft. The mount ring 32 is also
attached to at least one guide vane section 30 that extends from
the engine core 12 to the containment case 26. The example
containment case 26 includes the mount ring 32 that supports a
portion of the engine core 12. The guide vanes 30 that are disposed
rearward of the fan section 20 are static relative to the rotating
blades 28 and provide one of several mounting locations that
support the engine core 12.
[0023] Referring to FIG. 3, in one example the mount ring 32 is
secured onto an outer surface 34 of the aft end of the fan case 30
and overlaps a portion of the outer surface 34 of the composite
containment case 30. The mount ring 32 includes one or more
mounting flanges 42. The example mounting flange 42 extends
radially outward from the mount ring 32 to provide a connection to
the forward primary engine mount beam 36. The example mounting
flange 42 includes a fail safe lug 40 that extends upward between
primary lugs 38. The mounting flange 42 corresponds to a
configuration of the engine mount beam 36 for securing the engine
core 12 to the pylon 44 of the aircraft. As appreciated other
mounting flange configurations could be utilized with contemplation
of this disclosure, for example, as illustrated in FIG. 4.
[0024] Referring to FIG. 4 with continued reference to FIG. 3, the
example fan containment case 26 includes structure 46 comprised of
a plurality of composite layers forming the generally cylindrical
geometry of the fan containment case 26. The mount ring 32 fits
over the outer surface 34 of the fan containment case 26 and is a
forged ring of metal material in one example. The example mount
ring 32 includes a lead in chamfer 48 that aids in guiding the
mount ring 32 over the fan case 30 during assembly. The mount ring
32 also includes an axial locating feature for installation. The
example axial locating feature is a tab 50 that extends radially
inward to abut a back end 52 of the composite structure 46. The
mount ring 32 is slid onto the outer surface 34 to abut the tab 50
against the back end 52.
[0025] Once the mount ring 32 is positioned on the fan case 30,
fasteners 54 are arranged through openings 56 within the mount ring
32 and openings 58 in the composite structure 46 to attach the
mount ring 32 and the composite structure 46 to the fan exit guide
vanes 30. The combination of the interference fit along with the
plurality of fasteners 54 secure the mount ring 32 to the composite
structure 46. Further, the mount ring 32 is secured to the engine
core 12 by way of the guide vanes 30.
[0026] Referring to FIG. 5, another fan containment case 26' is
shown with a mount ring 32' that is integral with the composite
structure 46'. The term "integral" means the mount ring 32' and the
composite structure 46' are formed as a single unit. The fan exit
guide vanes 30 are secured to the composite structure 46' by
fasteners 54' arranged on either axial side of the primary lugs
38'.
[0027] Another attachment feature of the fan containment case 26 is
illustrated in FIG. 6. The fan containment case 26 has threaded
bolt attachments 72 are mounted on the outer surface 34. A
component 64 is attached to the attachments 72, such as through
pins 66 mounted at a bracket 68. In the example, the component 64
is a fluid tube. Any number of other components, and types of
mountings may benefit from the present invention. The bracket 68 is
threadingly attached, such as by bolts 70 (see FIG. 7), to the
attachment 72.
[0028] FIGS. 7 and 8 show a detail of the attachment 72, which
includes a molded conical boss which may be formed of a composite
material 74 arranged between multiple plies 78, 80. The boss may be
any number of different shapes including rectangular, square, oval,
etc. Metallic inserts 76 are embedded within the composite material
74. A combination of one or more plies and adhesive 86 are attached
to the outer surface of the composite material 74. This combination
will be attached to the outer surface 34 of the composite fan
containment case 26. The insert 76 has flat ends 82, which prevent
rotation within the composite material 74. A portion of the insert
includes a hole 84, which will receive a threaded insert (not
shown), in one example.
[0029] Referring to FIGS. 9 and 10 with continued reference to FIG.
3, an example metallic backing 90 is secured to a forward flange
portion 92 of the composite structure 46 with an adhesive 94 and/or
mechanical fasteners 96 to provide the attachment flange 62. The
composite structure 46 includes multiple layers 98. The example
mechanical fasteners 96 comprise rivets that extend through the
metallic backing 90 and into the forward flange portion 92. The
metallic backing 90 includes counter-bore holes 100 that receive
the entire head of the rivet 96 such that the rivet head does
protrude from the metallic backing 90. The metallic backing 90 and
the composite structure 46 define holes 102 for fasteners utilized
to secure the containment case 26 within the nacelle 22. The
metallic backing 90 includes a radius that corresponds to the
radius of the composite structure 46.
[0030] With reference to FIG. 11, the fan containment case 26
includes an inner structure 134, a ballistic liner 136, and the
outer case 138 defined about the axis A. The inner structure 134
may include an abradable layer 140 and a honeycomb structure 142.
The abradable layer 140 provides close tolerances to be maintained
between the fan blade tips and the inner structure 134. The
honeycomb structure 142 provides acoustic dampening as well as the
potential for retention of smaller blade fragments. It should be
understood that the inner structure 134 is light weight and
provides minimal, if any, resistance to blade fragment
penetration.
[0031] In one example, the ballistic liner 136 is a cylindrical
shell of a rigid material such as a resin impregnated KEVLAR
material such as KEVLAR XP.TM. for Hard Armor, LEXAN, metallic
structures, or ceramic materials. That is, the ballistic liner 136
is hard and operates as a rigid impact liner on the radially inner
surface of the outer case 138 which may be manufactured of a
composite material such as a carbon composite. The ballistic liner
136 need only extend a relatively short axial length as the hard
ballistic liner 136 is radially located directly outboard of the
fan blades 28.
[0032] In another example, the ballistic liner 136 generally
includes a plurality of unidirectional roving fiber layers and a
plurality of non-crimp fabric layers as described in Applicant's
co-pending application entitled "Case with Ballistic Liner," filed
on the same date as the present application and which is
incorporated by reference in its entirety. Generally, each of the
plurality of unidirectional roving fiber layers is about half the
thickness of each of the plurality of non-crimp fabric layers. In
one embodiment, each of the plurality of unidirectional roving
fiber layers includes three plies and each of the plurality of
non-crimp fabric layers includes two plies in the ballistic liner
136.
[0033] Although example embodiments have been disclosed, a worker
of ordinary skill in this art would recognize that certain
modifications would come within the scope of the claims. For that
reason, the following claims should be studied to determine their
true scope and content.
* * * * *