U.S. patent application number 13/652949 was filed with the patent office on 2013-06-13 for fan hub frame for double outlet guide vane.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is General Electric Company. Invention is credited to William Howard Hasting, Courtney James Tudor.
Application Number | 20130149130 13/652949 |
Document ID | / |
Family ID | 48572124 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130149130 |
Kind Code |
A1 |
Hasting; William Howard ; et
al. |
June 13, 2013 |
Fan Hub Frame for Double Outlet Guide Vane
Abstract
A fan hub frame comprises a circular hub having an opening
extending axially wherein an engine core is capable of being
positioned, the circular hub having a radially outer surface, the
radial outer surface having a plurality of cradles, each of the
cradles having a lower surface and fillets disposed between the
lower surface and upwardly extending sidewalls, the cradles capable
of receiving a double outlet guide vane.
Inventors: |
Hasting; William Howard;
(Cincinnati, OH) ; Tudor; Courtney James;
(Cincinnati, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company; |
Schenectady |
NY |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
48572124 |
Appl. No.: |
13/652949 |
Filed: |
October 16, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61568976 |
Dec 9, 2011 |
|
|
|
Current U.S.
Class: |
415/208.1 |
Current CPC
Class: |
F01D 9/042 20130101;
Y02T 50/673 20130101; Y02T 50/672 20130101; Y02T 50/60 20130101;
F05D 2300/6033 20130101 |
Class at
Publication: |
415/208.1 |
International
Class: |
F01D 25/00 20060101
F01D025/00 |
Claims
1. A fan hub frame, comprising: a circular hub having an opening
extending axially wherein an engine core is capable of being
positioned; said circular hub having a radially outer surface, said
radial outer surface having a plurality of cradles; each of said
cradles having a lower surface and fillets disposed between said
lower surface and upwardly extending sidewalls; said cradles
capable of receiving a double outlet guide vane.
2. The fan hub frame of claim 1 further comprising a plurality of
apertures in said cradle for connection with said double outlet
guide vane.
3. The fan hub frame of claim 2 wherein said double outlet guide
vane extends from said circular hub toward a fan case.
4. The fan hub frame of claim 1 further comprising a flowpath
surface on circumferential sides of said cradle.
5. The fan hub frame of claim 1 wherein said flowpath surface is
curved from a forward toward an aft end of said hub frame.
6. The fan hub frame of claim 1 further wherein said cradles are
spaced circumferentially about said radially outer surface.
7. The fan hub frame of claim 1, said fan hub frame transmitting
load through said cradles and double outlet guide vanes to engine
mounts.
8. A fan hub frame, comprising: a circular hub having a radially
outer surface and a radially inner opening wherein a propulsor may
be positioned; a plurality of cradles circumferentially spaced
along said radially outer surface of said circular hub; each of
said plurality of cradles defined by fillets capable of receiving a
double outlet guide vane; a plurality of fastener apertures
extending in a radial direction through said cradles.
9. The fan hub frame of claim 8, said cradles being curved along
the axial direction from a forward to rearward end of said
cradles.
10. The fan hub frame of claim 8, said fillets being curved along
the axial direction between axial forward and rearward ends.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This nonprovisional application claims priority to and
benefit under 35 U.S.C. .sctn.119(e) to U.S. Provisional
Application Ser. No. 61/568,976, filed on Dec. 9, 2011, the entire
contents of which are herein incorporated by reference.
BACKGROUND
[0002] The disclosed embodiments generally pertain to gas turbine
engines. More particularly present embodiments relate to the
structure of double fan outlet guide vanes and structural
components of a quick engine change assembly including the double
outlet guide vanes.
SUMMARY
[0003] An embodiment of the present invention provides a double
outlet guide vane assembly for a gas turbine engine. The assembly
has a first guide vane having a first end, a second end opposed to
the first end, and a second guide vane having a first end, a second
end opposed to its first end. A first end structure spans between
the first guide vane first end and the second guide vane first end.
A second end structure spans between the first guide vane second
end and the second guide vane second end. The first guide vane, the
second guide vane, the first end structure, and the second end
structure are integrally formed together to form a double vane with
a continuous outer surface, and a continuous inner surface.
[0004] An outlet guide vane assembly for a gas turbine engine
comprises a first guide vane having a first end, a second end
opposed to the first end, a second guide vane having a first end, a
second end opposed to the first end, a first end structure spanning
between the first guide vane first end and the second guide vane
first end, and a second end structure spanning between the first
guide vane second end and the second guide vane second end, wherein
the first guide vane, the second guide vane, the first end
structure, and the second end structure are integrally formed
together to form a double vane having a first end and a second end
opposed to the first end, and wherein the double vane has a
continuous outer surface and a continuous inner surface.
[0005] A double outlet guide vane comprises a first curved guide
vane and a second curved guide vane arranged in radially adjacent
fashion, each of said first and second curved guide vanes having a
pressure side, a suction side, a leading edge and a trailing edge,
a first end structure spanning between the first guide vane and the
second guide vane at a first end of the first and second guide
vanes, a second end structure extending from the first vane toward
said second vane at second ends of said first and second guide
vanes, the first and second end structures joined at fillets to the
first and second guide vanes, a flowpath defined between the first
and second curved guide vanes and the first end and the second end,
wherein a primary load path between a fan hub frame and forward
engine mount is defined through the double outlet guide vane.
[0006] A doublet guide vane, comprises a first end structure having
a radially inner surface and a radially outer surface, a second end
structure spaced from the first end structure, the second end
structure having a second radially inner surface and a second
radially outer surface, a first guide vane having a first leading
edge, a first trailing edge and first pressure and suction sides
extending between the first leading and trailing edges, a second
guide vane having a second leading edge, a second trailing edge and
second pressure and suction sides extending between the second
leading and trailing edges, the first and second end structures
joining the first and second guide vanes at fillets, the doublet
guide vane being capable of carrying a load between the forward
engine core and the forward engine mount.
[0007] A quick engine change assembly, comprises a first circular
frame member, a plurality of doublet supports spaced about the
first circular frame member, the doublet supports being contoured
along the axial direction, a flow surface defined between the
plurality of doublet supports and, a plurality of cradles, each of
the cradles including the doublet supports, the doublet supports
from a lower portion of the cradle to the flow surface.
[0008] A quick engine change assembly, comprises a continuous
circular frame having a first ring and a second ring, a cradle
formed axially between the first ring and the second ring, the
cradle having a radially inner portion and fillets extending
radially outward from the radially inner portion, the fillets
rising toward a flow path surface disposed adjacent the cradle.
[0009] A quick engine change assembly comprises a circular frame
formed of at least one circular ring, cradles extending in an axial
direction for receiving a fan double outlet guide vane, the cradles
including a plurality of supports for the fan double outlet guide
vane, a flow surface disposed between adjacent cradles and
extending in an axial direction, fastener apertures extending
through the circular frame in an axial direction capable of
connection to a fan hub frame.
[0010] A fan hub frame comprises a circular hub having an opening
extending axially wherein an engine core is capable of being
positioned, the circular hub having a radially outer surface, the
radial outer surface having a plurality of cradles, each of the
cradles having a lower surface and fillets disposed between the
lower surface and upwardly extending sidewalls, the cradles capable
of receiving a double outlet guide vane.
[0011] A fan hub frame comprises a circular hub having a radially
outer surface and a radially inner opening wherein a propulsor may
be positioned, a plurality of cradles circumferentially spaced
along the radially outer surface of the circular hub, each of the
plurality of cradles defined by fillets capable of receiving a
double outlet guide vane, a plurality of fastener apertures
extending in a radial direction through the cradles.
[0012] A structural platform comprises a first end, a second end, a
first side wall and a second side wall, a platform body extending
between the first end and the second end and further between the
first side wall and the second side wall, a first fillet joining
the first side wall and the platform body, a second fillet joining
the second side wall and the platform body, the sidewalls being
curved.
[0013] The structural platform, comprises a first side wall
extending between a first end and a second end, a second side wall
extending between a first end and a second end, a platform body
extending between the first side wall and the second side wall, and
from the first end to the second end, a fillet disposed between
each of the first sidewall and the second side wall, the first side
wall and the second side wall curved between the first end and the
second end, the curvature approximating a curvature of an airfoil
surface.
BRIEF DESCRIPTION OF THE ILLUSTRATIONS
[0014] Embodiments of the invention are illustrated in the
following illustrations.
[0015] FIG. 1 is a side section view of an exemplary turbine
engine.
[0016] FIG. 2 is a perspective view of a fan hub frame
assembly.
[0017] FIG. 3 is a perspective view of a double outlet guide vane
detailing the inner features of a radially inward end of the double
outlet guide vane and the outer features of a radially outward end
of the double outlet guide vane.
[0018] FIG. 4 is a perspective view of the double outlet guide vane
detailing the inner features of a radially outward end of the
double outlet guide vane and the outer features of the radially
inward end of a double outlet guide vane.
[0019] FIG. 5 is a perspective view of a double outlet guide vane
detailing the inner features of a radially inward end of a double
outlet guide vane and the outer features of a radially outward end
of a double outlet guide vane, with both ends having a structural
platform therein.
[0020] FIG. 6 is a perspective view of a double outlet guide vane
detailing the inner features of a radially outward end of the
double outlet guide vane and the outer features of a radially
inward end of the double outlet guide vane, with both ends having a
structural platform therein.
[0021] FIG. 7 is an exploded assembly illustration of the
embodiments shown in FIGS. 5 and 6.
[0022] FIG. 8 is an exploded assembly illustration of the
embodiments shown in FIGS. 5 and 6.
[0023] FIG. 9 is a perspective illustration of a radially inward
end of a double outlet guide vane and a structural platform therein
assembled to a fan hub frame.
[0024] FIG. 10 is a perspective illustration of a radially outward
end of a double vane and a structural platform therein assembled to
a fan case or aft fan case.
[0025] FIG. 11 is a perspective view of an aft fan case
assembly.
[0026] FIG. 12 is a partially exploded view of the aft fan case
assembly of FIG. 11.
[0027] FIG. 13 is a side section view of a forward portion of a gas
turbine engine.
[0028] FIG. 14 is a partially exploded side section view of the
forward engine portion shown in FIG. 13.
DETAILED DESCRIPTION
[0029] Reference now will be made in detail to embodiments
provided, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation, not
limitation of the disclosed embodiments. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present embodiments without departing
from the scope or spirit of the disclosure. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to still yield further embodiments. Thus it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0030] Referring to FIGS. 1-14, various embodiments of a gas
turbine engine 10 are depicted having a double outlet guide vane
with structural platforms. These structures may, but are not
required to, be utilized with a quick engine change assembly which
allows rapid removal of a propulsor. The double outlet guide vanes
may be formed of lightweight materials while still providing a
loadpath for the engine to the engine mount. Various improvements
are described herein.
[0031] As used herein, the terms "axial" or "axially" refer to a
dimension along a longitudinal axis of an engine. The term
"forward" used in conjunction with "axial" or "axially" refers to
moving in a direction toward the engine inlet, or a component being
relatively closer to the engine inlet as compared to another
component. The term "aft" used in conjunction with "axial" or
"axially" refers to moving in a direction toward the engine nozzle,
or a component being relatively closer to the engine nozzle as
compared to another component.
[0032] As used herein, the terms "radial" or "radially" refer to a
dimension extending between a center longitudinal axis of the
engine and an outer engine circumference. The use of the terms
"proximal" or "proximally," either by themselves or in conjunction
with the terms "radial" or "radially," refers to moving in a
direction toward the center longitudinal axis, or a component being
relatively closer to the center longitudinal axis as compared to
another component. The use of the terms "distal" or "distally,"
either by themselves or in conjunction with the terms "radial" or
"radially," refers to moving in a direction toward the outer engine
circumference, or a component being relatively closer to the outer
engine circumference as compared to another component.
[0033] As used herein, the terms "lateral" or "laterally" refer to
a dimension that is perpendicular to both the axial and radial
dimensions.
[0034] Referring initially to FIG. 1, a schematic side section view
of a gas turbine engine 10 is shown having an engine inlet end 12
wherein air enters the propulsor 13 which is defined generally by a
compressor 14, a combustor 16 and a multi-stage high pressure
turbine 20. Collectively, the propulsor 13 provides thrust or power
during operation. The gas turbine 10 may be used for aviation,
power generation, industrial, marine or the like. Depending on the
usage, the engine inlet end 12 may alternatively contain
multi-stage compressors rather than a fan. The gas turbine 10 is
axis-symmetrical about engine axis 26 or shaft 24 so that various
engine components rotate thereabout. In operation air enters
through the air inlet end 12 of the engine 10 and moves through at
least one stage of compression where the air pressure is increased
and directed to the combustor 16. The compressed air is mixed with
fuel and burned providing the hot combustion gas which exits the
combustor 16 toward the high pressure turbine 20. At the high
pressure turbine 20, energy is extracted from the hot combustion
gas causing rotation of turbine blades which in turn cause rotation
of the shaft 24. The shaft 24 passes toward the front of the engine
to continue rotation of the one or more compressor stages 14, a
turbofan 18 or inlet fan blades, depending on the turbine
design.
[0035] The axis-symmetrical shaft 24 extends through the through
the turbine engine 10, from the forward end to an aft end. The
shaft 24 is supported by bearings along its length. The shaft 24
may be hollow to allow rotation of a low pressure turbine shaft 28
therein. Both shafts 24, 28 may rotate about the centerline axis 26
of the engine. During operation the shafts 24, 28 rotate along with
other structures connected to the shafts such as the rotor
assemblies of the turbine 20 and compressor 14 in order to create
power or thrust depending on the area of use, for example power,
industrial or aviation.
[0036] Referring still to FIG. 1, the inlet 12 includes a turbofan
18 which has a plurality of blades. The turbofan 18 is connected by
the shaft 28 to the low pressure turbine 19 and creates thrust for
the turbine engine 10. The low pressure air may be used to aid in
cooling components of the engine as well.
[0037] A typical gas turbine engine generally possesses a forward
end and an aft end with its several components following inline
therebetween. An air inlet or intake is at a forward end of the
engine. Moving toward the aft end, in order, the intake is followed
by a compressor, a combustion chamber, a turbine, and a nozzle at
the aft end of the engine. It will be readily apparent from those
skilled in the art that additional components may also be included
in the engine, such as, for example, low-pressure and high-pressure
compressors, high-pressure and low-pressure turbines, and an
external shaft. This, however, is not an exhaustive list. An engine
also typically has an internal shaft axially disposed through a
center longitudinal axis of the engine. The internal shaft is
connected to both the turbine and the air compressor, such that the
turbine provides a rotational input to the air compressor to drive
the compressor blades. A typical gas turbine engine may also be
considered to have an outer circumference with a central
longitudinal axis therethrough.
[0038] Referring to FIG. 2, a perspective view of a fan frame
assembly 100 is shown. The fan frame assembly 100 is generally
provided with a first circular frame member or fan hub frame 102, a
second circular frame member or fan case 104, and a plurality
double outlet ("doublet") guide vanes 200 disposed in a radial
array about the hub frame 102 and fan case 104. The assembly 100
has a central longitudinal axis 101 that disposed therethrough that
is generally the longitudinal axis of a gas turbine engine 26 (FIG.
1) with which the assembly 100 would be associated. The fan hub
frame 102 may also be known by other names such as an intermediate
compressor case. The doublet guide vanes 200 provide the load path
from the fan hub frame (and thereby the propulsor 13) to the
forward engine mount (not shown).
[0039] Referring to FIGS. 3 and 4, opposing perspective views of a
double outlet guide vane 200 are provided. The double vane 200 is
provided with a first guide vane 202, and a second guide vane 204.
A first end structure 206 spans between a radially inward first end
of the first guide vane 202 and a radially inward first end of the
second guide vane 204. A second end structure 208 spans between a
radially outward second end of the first guide vane 202 and a
radially outward second end of the second guide vane 204. The first
guide vane 202, the second guide vane 204, the first end structure
206, and the second end structure 208 are integrally formed
together to form a double vane 200 with a substantially continuous
outer surface, and a substantially continuous inner surface. A flow
path 210 for a fluidized flow is provided therethrough.
[0040] The double outlet guide vane 200 may be manufactured of a
variety of materials, such as, for example, composite materials, or
metals. One such material may be a fiber composite, such as a
carbon fiber composite laminate. The doublet vane 200 may be
manufactured in a way that the fibers are continuously and
uninterruptedly wound around the doublet vane 200. The method to
manufacture such a structure may be accomplished by, for example,
resin transfer molding with dry fiber, automated fiber placement,
or a hand layup process with pre-impregnated fiber. The doublet
vane 200 may also be manufactured from metal, such as, for example,
aluminum alloys, titanium alloys, and other known alloys suitable
for use in a gas turbine engine.
[0041] Referring now to FIGS. 5 and 6, a double outlet vane 200 is
shown in perspective view with first and second structural
platforms 306, 308 abutting an inner surface of the first and
second end structures 206, 208. The first and second structural
platforms 306, 308 have a surface that faces the inner surface of
the first and second end structures 206, 208 and generally matches
the geometry and contours of the inner surface of the first and
second end structures 206, 208. The structural platforms 306, 308
are utilized to spread loads experienced by the double vanes 200 to
the surrounding hardware to which they are attached, such as the
fan hub frame 102 and the fan case 104.
[0042] Referring now to FIGS. 7, an exploded assembly view of an
inner surface of a double vane first end structure 206 and a first
structural platform 306 is provided. FIG. 8 is an exploded assembly
view of an assembly of an inner surface of a double vane second end
structure 208 and a second structural platform 308. When assembled
to the fan hub frame 102 and the fan case 104, the first end
structure 206 is disposed between the first structural platform 306
and the fan hub frame 102 (see FIG. 9). Likewise, the second end
structure 208 is disposed between the second structural platform
308 and the fan case 104 (See FIG. 10). The first and second end
structures and their respective structural platforms may be the fan
case assembly by fasteners 312 or by any known bonding methods. The
first and second end structures and their respective structural
platforms may be mounted to one another by any known bonding
methods. The platforms 306, 308 provide rigidity and stability for
the doublets 200 while allowing the doublet 200 to be formed of
lightweight materials.
[0043] Referring now to FIGS. 9 and 10, perspective views of the
assembly 100 are shown. The plurality of double vanes 200 are
provided assembled to a fan hub frame 102 and a fan case 104. In
FIG. 9, the first end structure 206 is mounted to a radially outer
surface of the fan hub frame 102. The radially outer surface 216 of
the fan hub frame 102 may be provided with a cradle-like structure
218 that conforms to match the geometry and contours of the outer
surface of the first end structure 206. The cradles 218 include
fillets 220 which form supports, along with the sidewall of the
cradle 218 for the double vane outlets 200. In FIG. 10, the second
end structure 208 is mounted to a radially inner surface of the fan
case 104. The radially inner surface of the fan case 104 is shown
without a cradle-like structure. However, a cradle-like structure
may be utilized. Still, the inner surface of the fan case 104
conforms to the outer surface of the second end structure 208. In
both configurations, the first and second end structures 206, 208
are disposed between the first and second structural platforms 306,
308 and the fan hub frame 102 and fan case 104, respectively. As
shown, the hub frame 102 is provided with cradle-like structures,
and the fan case 104 is not. However, either of the hub frame 102
or the fan case 104 may be provided with or without a cradle-like
structure in any combination.
[0044] Referring now to FIG. 11, a perspective view of an aft fan
case assembly 400 is depicted. According to previous embodiments,
the double outlet or doublet guide vanes 200 were positioned in a
fan hub frame 102 (FIG. 2). However, the present embodiment
provides that the doublet guide vanes 200 are disposed in a quick
engine change configuration. As with the previous embodiment, the
instant embodiment provides a primary loadpath through the aft fan
case assembly 400 and the double outlet guide vanes 200. The aft
fan casing assembly 400 includes a first circular frame 410 at an
inner radius and a second circular frame 412 at an outer radius
wherein the doublet guide vanes 200 are disposed therebetween.
According to some embodiments, first circular frame 410 is a quick
engine change ring and the second circular frame 412 is a fan case,
such as an aft fan case, for example. The quick engine change ring
410 allows for easy separation, generally shown in FIG. 14, of the
doublet vane assembly from the propulsor components 13 which are
generally in need of more frequent maintenance. The propulsor
components 13 may be worked on for scheduled or unscheduled
maintenance. Meanwhile a second propulsor may be installed in the
quick engine change ring 410 so that the engine can be returned to
service sooner, if desired.
[0045] The quick engine change ring 410 includes a first ring 422
and a second ring 424. The rings 422, 424 are spaced axially in the
direction of the engine axis 26 and may each be formed of one piece
continuous or multiple pieces connected together. Extending in an
axial direction between the first ring 422 and the second ring 424
are a plurality of flow surfaces 416. The flowpath surfaces 416
improve air movement across the rings 422, 424 while allowing the
weight saving design of the two rings rather than a solid or other
otherwise heavier structure. Extending in the axial direction
between the first and second rings 422, 424 and further between the
flow surfaces 416 are cradles 418. Each of the cradles 418 includes
a curved portion where the lowermost portion of the cradle curves
up toward the flow surface 416. A stationary doublet guide vane 200
is positioned within each of the cradles 418 in order to turn an
airflow in a desirable manner through portions of a gas turbine
engine 10. Flowpaths are created between each of the vanes 202,204
and between the cradles 418. According to this embodiment, the
propulsor 13 may be quickly disconnected for ease of removal and
replacement allowing continued service of the engine.
[0046] Referring now to FIG. 12, an exploded perspective view of a
portion of the aft fan case assembly 400 is shown. The quick engine
change ring 410 is shown at the bottom of the figure. Extending
between the first ring 422 and the second ring 424 are flow
surfaces 416. These provide a flow or control surface along which
air can move as it passes between the doublet guide vanes 200. The
flow surface 416 depicted is curved between the forward ring 422
and the rear ring 424. The flow surface may also be curved in the
circumferential direction. The flow surface 416 may alternatively
be linear between the first and second rings 422, 424 and/or the
circumferential direction. The quick engine change ring 410
includes the cradles 418 between the flow surfaces 416. The cradles
418 receive the radially inner ends of the doublet guide vanes 200
and have curved surfaces 420 which transition between the cradles
418 and flow surfaces 416. Within the cradles 418 along the first
ring 422 and second ring 424 are fastener apertures 419 which
extend through the rings or hoops in a generally axial direction
relative to the engine. The apertures 419 are used to connect the
doublet guide vanes 200 to the quick engine change ring 410. The
first and second rings also include apertures 426, 428 respectively
allowing quick disconnect of the aft fan case assembly 400 from the
propulsor 13, as will be discussed further herein.
[0047] Beneath the doublet guide vane 200 is the cradle 418 which
provides a seating location for the doublet vane 200. The cradle
418 has a U-shaped cross-section which curves moving in the axial
direction from the first ring 422 to the second ring 424. The
cradles 418 extend up the sides of the vane 200 to support the
lowed ends of the guide vanes 202, 204. The height at which the
flowpath surfaces 416 are disposed and curved portions 420 causes
cradling of the doublet vane 200. This cradling provides additional
support and limits flexing of the doublet vane 200 during
operation. The cradle 418 further comprises curved surfaces or
fillets to improve rigidity of the circular frame 310 and improve
manufacturability.
[0048] The outer ring or fan case 412 is also exploded to depict
the radially outer ends of the doublet vanes 200. The fan case 412
receives fasteners which extend through an upper surface 208 of the
doublet guide vane 200 and through the fan case 412. Each doublet
vane 200 is connected to the fan case assembly 400 by sandwiching
the doublet guide vane 200 between platform 308 and the fan case
412.
[0049] Also shown within the assembly 400 are structural platforms
306, 308. At the radially inner end of the doublet guide vane 200
is an inner structural platform 306 which sandwiches the first or
inner end 206 of the vane 200. The structural platform 306 has a
lower surface which curves near lateral sides to match the
curvature of 207 the first end 206. The platform 306 is positioned
above the lower portion 206 of the doublet vane 200 which is above
the circular quick engine change ring 410. According to the
embodiment depicted, the platform 306 has first and second bolt
apertures 307 which are aligned with apertures 211 in the lower end
206 of the doublet vane 200. The platform 306 and vane 200 are then
bolted to the quick engine change ring 410 through apertures 419 in
the first ring 422 and the second ring 424. This sandwiches or
captures the lower end 206 of vane 200 in the cradle 418 of the
quick engine change ring 410. Such construction provides various
improvements over prior art designs. First the composite guide vane
200 is sandwiched between a structural platform and the quick
engine change ring 410. This provides a significant increase in
stiffness. Additionally, the construction does not require any
adhesive bonds which may deteriorate due to the high operating
temperature of the gas turbine engine. The design also provides
that there are no composite to metal transitions or integrations.
Finally, the design provides greater aeromechanical margins and
greater damping during operation.
[0050] Similarly, at the upper or radially outer end 208 of the
guide vane 200 is the structural platform 308 which sandwiches the
upper end 208 between the platform 308 and the fan case 412.
Lateral ends of the platform 308 are curved to fit against the
curved ends 209 of the platforms 200, providing structural support
in at least the lateral or circumferential directions.
[0051] Each of the lower and upper end structures 206, 208 has a
radially inner and radially outer surface. Each of the structures
206, 208 may be formed integrally with the vanes 202, 204 or may be
formed of one or more pieces which are joined with the vanes 202,
204 to form the doublet guide vane 200.
[0052] Referring still to FIG. 12, structural platforms 306, 308
are shown. The platforms 306, 308 comprise a first end 312, a
second end 314, a first side wall 316 and a second side wall 318. A
platform body 320 extends between the first end 312 and the second
end 314 between the first side wall 316 and said second side wall
318. A first fillet 322 joins the first side wall 316 and the
platform body 320. Similarly, a second fillet 324 joins the second
side wall 318 and the platform body 320. The sidewalls 316, 318 are
curved to correspond to the curvature of the vanes 202, 204. The
structural platform sandwiches a doublet guide vane 200 within a
cradle 418. The platform body 420 may further comprise a skin
facing an airflow and having a smooth surface. This may be formed
of composite of metal and bonded to the platforms 306, 308. The
structural platforms 306, 308 may be formed of one of metal,
plastic or composite. The structural platforms may have first side
wall and second side walls which extend in a radial direction. The
first side wall 316 and the second side wall 318 may be being
curved to approximate a mating airfoil surface. The platform body
having a plurality of apertures 307, 311 for receiving fasteners.
Additionally, the structural platform may further comprise
structural stiffeners (330) extending between said first and second
side walls.
[0053] Means may be utilized to make connection between the
exemplary embodiments of the platforms 306, 308 to the guide vanes
200 and ring 410 and case 412. According to exemplary embodiments,
fasteners are utilized through apertures 307 and 311. Additionally,
while the inner surface of platform 306 is shown as uneven or
non-smooth, an insert, skin or cover may be used to provide a
smooth surface for improved airflow through the guide vane 200.
This skin or cover may be used to also cover bolt holes sandwiching
the platforms 306, 308 the doublet vanes 200 and first and second
circular frame members 102, 104 and 410, 412.
[0054] The quick engine change ring assembly 400 utilizes a
circular frame member 410 formed according to one example of a
first continuous ring 422 and a second continuous ring 424 which
are positioned parallel to one another in an axial direction. The
assembly 400 further comprises flow surfaces 416 which extend from
the first ring 422 to the second ring 424 and between the doublet
vanes 200. The flow surfaces 416 are raised from the first and
second continuous rings 422, 424. As a result, the cradles 418
between the flow surfaces 416 are formed wherein the doublet vanes
200 may be positioned.
[0055] Referring still to FIG. 12, the doublet guide vanes 200 are
shown. As previously described, the guide vanes 200 include first
and second vanes 202, 204 which extend from a leading edge to a
trailing edge in a chord-wise direction. Each guide vane has a
pressure side and a suction side. The vanes 202, 204 are shorter at
the outer diameter than the inner diameter. Additionally, the
doublet guide vanes are wider in a circumferential direction at the
upper end 208 than the inner end 206. At the first, radially inner
end 206, the guide vanes 202, 204 are joined to provide a rigid
lower end. Each vanes 202, 204 are arranged in circumferentially
adjacent fashion, two per guide vane 200 according to one exemplary
embodiment. Other arrangements may be utilized. The radially inner
end structure 206 joins the guide vanes 202, 204 at the radially
inner end to provide rigidity. Similarly, at the opposed radially
outer end 208 the guide vanes 202, 204 are joined to provide a
closed structure. At the upper end 208, the guide vanes 202, 204
curve 209 to join the upper end 208 similar to the curved or radius
207 at the lower end 206. The radiuses 207, 209 are received in
correspondingly curved doublet supports 420 of the cradle 418 and
the fan case 412. These curved areas provide strength and support
for the doublet guide vanes 200 and the structural platforms 306,
308 provide further support. The doublet guide vanes 200 may be
formed of metal, or composite material.
[0056] Referring again briefly to FIG. 11, the assembly 400
includes a plurality of single vanes 500, as opposed to the doublet
guide vanes 200. The single vanes 500 are generally formed of metal
and are of higher strength than the double guide vanes 200. The
single guide vanes 500 are utilized to carry higher loads through
to the engine mounts for the gas turbine engine. The vanes 500
include feet 502 which connect the vane 500 to the inner rings 422
and 424. According to the exemplary embodiment, there are four feet
502 at the radially inner end of the vane 500, two feet axially
forward and two feet axially rearward. The radially inner feet may
be connected to, for example, the fan hub frame 102, or may be
connected to a quick engine change assembly described further
herein. At the outer end of the vanes 500 there are also four feet
502 (not shown) which connect the vane to the radially outer
structure, for example the fan case 104, 412.
[0057] Referring now to FIG. 13, a side section view of a portion
of a gas turbine engine 10 is depicted. Specifically forward aft
case assembly 110 is shown and the aft fan case assembly 200 is
shown joined at a lug or flange connection 112.
[0058] The forward fan case assembly 110 includes the fan 18
secured to a disc 19 and axially rearward of a spinner or cone 21.
The fan 18 and disc 19 rotate about the engine axis 26. Aft of the
fan 18 is a compressor 14 which is a part of the propulsor 13,
generally referring to all of the core components of the engine
causing propulsion such as the turbine, shafts, compressor 14 which
extend from the forward fan case assembly 110, through the aft fan
case assembly 200 and aft to define the gas turbine engine 10. A
booster panel 32 extends axially above the compressor 14 and
connects to the quick engine change ring 410. The booster panel 32
limits air flow in the compressor 14 from mixing with air moving
through the guide vanes 200. The guide vanes 200 extend between the
quick engine change ring 410 and the aft fan case 412.
[0059] As previously stated, the quick engine change embodiment
provides for easy change engine components, specifically
propulsors, which generally have fail parts and wear parts with
higher maintenance requirements.
[0060] With reference now to FIG. 14, the internal components of
the of the engine propulsor 13 are disconnected from the aft fan
case assembly 400. This allows the quick change of either the fan
case assembly 400 or the propulsor components 13. Specifically, the
spinner or cone 21 is removed from the forward end of the engine at
the engine intake area. Next, the fan blades 18 are removed and
pulled axially forward from the engine. The booster panels 32 are
removed after the fan blades 18.
[0061] With these parts removed, the axial forward and rearward
bolts are removed from the quick engine change ring 410. The
axially forward fastener apertures 426 and axially rearward
apertures 428 are best shown in FIG. 12. These apertures 426, 428
are used to connect the radially inner propulsor 13 to the radially
outer quick engine change ring 410 and the outward components of
the aft fan case assembly 400. With these bolts removed from
aperture 426, 428, the propulsor 13 can be removed in an axially
rearward direction from the aft fan case assembly 400.
[0062] Various means may be utilized to make connection between the
exemplary embodiments of the platforms 306, 308 to the guide vanes
200 and ring 410 and case 412. According to exemplary embodiments,
fasteners are utilized through apertures 307 and 311. Additionally,
while the inner surface of platform 306 is shown as uneven or
non-smooth, an insert or cover may be used to provide a smooth
surface for improved airflow through the guide vane 200.
[0063] The foregoing description of structures and methods has been
presented for purposes of illustration. It is not intended to be
exhaustive or to limit the invention to the precise steps and/or
forms disclosed, and obviously many modifications and variations
are possible in light of the above teaching. Features described
herein may be combined in any combination. Steps of a method
described herein may be performed in any sequence that is
physically possible. It is understood that while certain forms of
an outlet guide vane with structural platforms have been
illustrated and described, it is not limited thereto and instead
will only be limited by the claims, appended hereto.
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