U.S. patent application number 13/769599 was filed with the patent office on 2016-06-16 for actuation system for a translating variable area fan nozzle.
This patent application is currently assigned to Goodrich Actuation Systems Limited. The applicant listed for this patent is GOODRICH ACTUATION SYSTEMS LIMITED, ROHR, INC.. Invention is credited to Daniel M. Amkraut, Vikram Chandarana, Alan K. Evans, John Harvey, Andrew Robert Hawksworth, Roger Moorehouse, Geoffrey Pinto, Jihad I. Ramlaoui, Daniel Shetzer.
Application Number | 20160169158 13/769599 |
Document ID | / |
Family ID | 40364427 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160169158 |
Kind Code |
A9 |
Ramlaoui; Jihad I. ; et
al. |
June 16, 2016 |
ACTUATION SYSTEM FOR A TRANSLATING VARIABLE AREA FAN NOZZLE
Abstract
A variable area fan nozzle assembly for a turbofan engine
includes a nacelle having an aft edge and a translating thrust
reverser sleeve with a trailing edge. The thrust reverser sleeve is
movably disposed aft of the nacelle's aft edge and is movable
between a forward position and an aft position. A translating fan
nozzle having a forward edge is movably disposed behind the
trailing edge, and is movable between a stowed position and a
deployed position. An upstream bypass flow exit is defined between
the trailing edge and the forward edge when the fan nozzle is in
the deployed position. An extendable actuation system is configured
to move the fan nozzle between the stowed position and the deployed
position.
Inventors: |
Ramlaoui; Jihad I.; (Chula
Vista, CA) ; Pinto; Geoffrey; (San Diego, CA)
; Shetzer; Daniel; (San Diego, CA) ; Amkraut;
Daniel M.; (San Diego, CA) ; Hawksworth; Andrew
Robert; (Shropshire, GB) ; Harvey; John;
(Wolverhampton, GB) ; Evans; Alan K.;
(Wolverhampton, GB) ; Chandarana; Vikram;
(Wolverhampton, GB) ; Moorehouse; Roger; (South
Staffordshire, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ROHR, INC.
GOODRICH ACTUATION SYSTEMS LIMITED |
Chula Vista
Wolverhampton |
CA |
US
GB |
|
|
Assignee: |
Goodrich Actuation Systems
Limited
Wolverhampton
CA
Rohr, Inc.
Chula Vista
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20130161414 A1 |
June 27, 2013 |
|
|
Family ID: |
40364427 |
Appl. No.: |
13/769599 |
Filed: |
February 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12485559 |
Jun 16, 2009 |
8511062 |
|
|
13769599 |
|
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|
|
PCT/US2008/072448 |
Aug 7, 2008 |
|
|
|
12485559 |
|
|
|
|
60954756 |
Aug 8, 2007 |
|
|
|
Current U.S.
Class: |
239/265.19 ;
74/89.32 |
Current CPC
Class: |
F02K 1/09 20130101; Y10T
74/18576 20150115; F02K 1/30 20130101; F02K 1/72 20130101; F02K
1/70 20130101; F02K 1/763 20130101; Y10T 74/18648 20150115; F02K
3/06 20130101; F05D 2250/34 20130101 |
International
Class: |
F02K 1/76 20060101
F02K001/76 |
Claims
1. A variable area fan nozzle assembly for a turbofan engine, the
assembly comprising: (a) a nacelle having an aft edge; (b) a
translating thrust reverser sleeve movably disposed aft of the aft
edge and including a trailing edge, the thrust reverser sleeve
being movable between a forward position and an aft position; (c) a
translating fan nozzle having a forward edge, the fan nozzle being
movably disposed behind the trailing edge and being movable between
a stowed position and a deployed position, wherein an upstream
bypass flow exit is defined between the trailing edge and the
forward edge when the fan nozzle in the deployed position; and (d)
an actuation system for selectively moving the fan nozzle between
the stowed position and the deployed position, the actuation system
comprising a power drive unit, at least one extensible actuator
disposed between the thrust reverser sleeve and the fan nozzle, and
at least one telescoping coupling disposed between the thrust
reverser sleeve and the nacelle; (e) wherein the extensible
actuator is rotatably coupled to the power drive unit through the
telescoping coupling; (f) wherein the extensible actuator and the
telescoping coupling are substantially axially aligned.
2. A variable area fan nozzle assembly according to claim 1 wherein
the telescoping coupling comprises a rotating sleeve and a shaft
slidably received within the rotating sleeve.
3. A variable area fan nozzle assembly according to claim 2 wherein
at least a portion of the shaft includes a plurality of
circumferentially spaced splines, and the rotating sleeve includes
a bore having a plurality of grooves configured to receive the
splines.
4. A variable area fan nozzle assembly according to claim 1 and
further comprising at least one variable displacement transducer
configured to detect displacement of the fan nozzle.
5. A variable area fan nozzle assembly according to claim 4 wherein
the variable displacement transducer is operably connected to an
engine control system.
6. A variable area fan nozzle assembly according to claim 1 and
comprising a first extensible actuator and a second extensible
actuator disposed between the thrust reverser sleeve and the fan
nozzle, wherein the first extensible actuator and the second
extensible actuator are rotatably coupled to the power drive unit
through a single telescoping coupling.
7. An actuator for a translating variable area fan nozzle
comprising: (a) an extensible portion comprising a jack screw and a
translating threaded sleeve threadably engaged with the jack screw;
and (b) a telescoping coupling rotatably coupled to the extensible
actuator, wherein the length of the telescoping coupling can be
altered between a first length and a second length that is longer
than the first length while maintaining rotational engagement with
the extensible actuator.
8. An actuator according to claim 7 wherein the extensible actuator
has a first axis and the telescoping coupling has a second axis,
the first axis is offset from the second axis, and the telescoping
coupling is rotatably coupled to the extensible actuator by a jack
head.
9. An actuator according to claim 7 wherein rotation of the
telescoping coupling at a first rotational speed causes rotation of
the jack screw at a second rotational speed that is different from
the first rotational speed.
10. An actuator according to claim 7 wherein the telescoping
coupling comprises a shaft that is slidably received in an
elongated sleeve, and wherein at least a portion of the shaft
includes splines that are slidably received in grooves within the
elongated sleeve, wherein the splines and grooves substantially
prevent relative rotation between the shaft and elongated sleeve
when the shaft is received in the elongated sleeve.
11. An actuator system for selectively displacing a translating
variable area fan nozzle between a stowed position and a deployed
position, the system comprising: (a) at least one actuator
comprising a jack screw and a telescoping coupling; and (b) a power
drive unit operably connected to the jack screw through the
telescoping coupling.
12. An actuator system according to claim 11 wherein the jack screw
and the telescoping coupling are substantially axially aligned.
13. An actuator system according to claim 11 wherein the jack screw
has a first axis and the telescoping coupling has a second axis,
and the first axis is offset from the second axis.
14. An actuator system according to claim 11 wherein rotation of
the telescoping coupling at a first rotational speed causes
rotation of the jack screw at a second rotational speed that is
different from the first rotational speed.
15. An actuator system according to claim 14 wherein the
telescoping coupling comprises a shaft that is slidably received in
an elongated sleeve, and wherein at least a portion of the shaft
includes splines that are slidably received in grooves within the
elongated sleeve, wherein the splines and grooves substantially
prevent relative rotation between the shaft and elongated sleeve
when the shaft is received in the elongated sleeve.
16. An actuator system according to claim 11 wherein the
telescoping coupling is connected to the power drive unit by one or
more flexible shafts.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 12/485,559, filed Jun. 16, 2009, which is a
continuation-in-part of international application Serial No.
PCT/US08/72448, filed Aug. 7, 2008, which claims the benefit of
priority of U.S. Provisional Application Ser. No. 60/954,756, filed
Aug. 8, 2007, the disclosures of which are hereby incorporated by
reference in their entireties.
TECHNICAL FIELD
[0002] The present invention generally relates to gas turbine
aircraft engines, and particularly relates to an actuation system
for a translating variable area nozzle assembly for a turbofan
aircraft engine for use in selectively controlling the fan bypass
flow exhausted from the engine in order to adjust the engine's
performance under varying flight conditions.
BACKGROUND
[0003] Typical aircraft turbofan jet engines include a fan that
draws and directs a flow of air into a nacelle and into and around
an engine core. The nacelle surrounds the engine core and helps
promote the laminar flow of air around the core. The flow of air
that is directed into the engine core is initially passed through a
compressor that increases the air flow pressure, and then through a
combustor where the air is mixed with fuel and ignited. The
combustion of the fuel and air mixture causes a series of turbine
blades at the rear of the engine core to rotate, and to drive the
engine's rotor and fan. The high-pressure exhaust gases from the
combustion of the fuel and air mixture are thereafter directed
through an exhaust nozzle at the rear of the engine.
[0004] Bypass flow is air that is directed around the engine core.
In turbofan engines, the bypass flow typically provides the main
thrust for an aircraft. The bypass flow also can be used to help
slow a landed aircraft. Thrust reversers mounted in the nacelle
structure selectively reverse the direction of the bypass flow to
generate reverse thrust. During normal engine operation, the bypass
flow may or may not be mixed with the engine core exhaust before
exiting the engine assembly.
[0005] Several turbofan engine parameters are important to optimize
design characteristics and performance. An engine's bypass ratio
(BPR) is the ratio of the air mass that passes through the engine's
fan duct to that passing through the engine core. Higher BPR
engines can be more efficient and quiet than lower BPR engines. In
general, a higher BPR results in lower average exhaust velocities
and less jet noise at a specific thrust rating. A turbofan engine's
performance is also affected by the engine's fan pressure ratio
(FPR). FPR is the ratio of the air pressure at the engine's fan
nozzle exit to the pressure of the air entering the fan. The lower
the FPR, the lower the exhaust velocity, and the higher an engine's
propulsive efficiency. Reducing an engine's FPR can reach a
practical limit, however, as a low FPR can cause engine fan stall,
blade flutter or compressor surge under certain operating
conditions.
[0006] One solution to these problems includes varying the fan
nozzle exit area of a high-BPR engine during operation to optimize
engine performance under various flight conditions. By selectively
varying the fan nozzle's exit area, an engine's bypass flow
characteristics can be adjusted to match a particular flight
condition. Unfortunately, prior variable area nozzle systems
typically have been heavy, expensive and somewhat complex in their
structure and operation, and generally require the coordinated
movement of multiple components that employ complex drive
mechanisms.
[0007] Accordingly, a need exists for a variable area nozzle
assembly for turbofan aircraft engine that promotes a cost
effective, simple and efficient operation for control of engine
output under certain flight conditions. In particular, there is a
need for an actuation system for selectively translating a nozzle
of such a variable area nozzle assembly.
SUMMARY
[0008] In one embodiment, a variable area fan nozzle assembly for a
turbofan engine includes a nacelle having an aft edge and a
translating thrust reverser sleeve having a trailing edge. The
thrust reverser sleeve can be movably disposed aft of the nacelle's
aft edge and can be movable between a forward position and an aft
position. The variable area fan nozzle assembly can further include
a translating fan nozzle having a forward edge. The fan nozzle can
be movably disposed behind the trailing edge, and can be movable
between a stowed position and a deployed position. An upstream
bypass flow exit can be defined between the trailing edge and the
forward edge when the fan nozzle is in the deployed position. The
variable area fan nozzle assembly can also include an actuation
system for selectively moving the fan nozzle between the stowed
position and the deployed position. The actuation system can
include a power drive unit, at least one extensible actuator
disposed between the thrust reverser sleeve and the fan nozzle, and
at least one telescoping coupling disposed between the thrust
reverser sleeve and the nacelle. The extensible actuator can be
rotatably coupled to the power drive unit through the telescoping
coupling.
[0009] In another embodiment, an actuator for a translating
variable area fan nozzle includes an extensible portion comprising
a jack screw and a translating threaded sleeve threadably engaged
with the jack screw. A telescoping coupling can be rotatably
coupled to the extensible actuator. The length of the telescoping
coupling may be altered between a first length and a second length
that is longer than the first length while rotational engagement
with the extensible actuator is maintained.
[0010] In a further embodiment, an actuator system for selectively
displacing a translating variable area fan nozzle between a stowed
position and a deployed position includes at least one actuator
having a jack screw and a telescoping coupling. A power drive unit
can be operably connected to the jack screw through the telescoping
coupling.
[0011] In another embodiment, an actuator system for a variable
area fan nozzle includes a jack screw actuator having an input end,
and a power drive unit. The actuator system can also include means
for coupling the power drive unit to the input end of the jack
screw actuator. The means for coupling can be configured to
accommodate substantial translational displacement between the
input end of the jack screw actuator and the power drive unit.
[0012] The foregoing and other features, aspects, and advantages of
the invention will be apparent from a reading of the following
detailed description together with the accompanying drawings, which
are briefly described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] According to common practice, the various features of the
drawings discussed below are not necessarily drawn to scale.
Dimensions of various features and elements in the drawings may be
expanded or reduced to more clearly illustrate the embodiments of
the invention.
[0014] FIG. 1 is a perspective view of an aircraft engine having a
cascade-type thrust reverser and a translating variable area fan
nozzle assembly.
[0015] FIG. 2 is a longitudinal cross section of an aircraft
engine.
[0016] FIG. 3 is a rear elevation of an aircraft engine.
[0017] FIG. 4 is a perspective view of the thrust reverser and
translating variable fan area nozzle assembly portions of an
aircraft engine with a thrust reverser sleeve in a stowed position,
and a variable area fan nozzle ring in a deployed position.
[0018] FIG. 5 is a perspective view of a thrust reverser and
translating variable area fan nozzle assembly with both the thrust
reverser sleeve and the variable area fan nozzle ring in deployed
positions.
[0019] FIG. 6 is an exploded perspective view of the thrust
reverser and translating variable area fan nozzle assembly shown in
FIGS. 4-5.
[0020] FIG. 7 is a cross sectional view of a track beam assembly
for movably supporting a thrust reverser sleeve and a variable area
fan nozzle ring.
[0021] FIG. 8 is a partial cross sectional view of a thrust
reverser and variable area nozzle assembly.
[0022] FIG. 9 is a perspective view of a portion of a first
embodiment of a VAFN actuation system for selectively translating a
variable area fan nozzle like that shown in FIGS. 1-8.
[0023] FIG. 10 is a cross-sectional view of the portion of the VAFN
actuation system shown in FIG. 9 taken along line 10-10 and showing
the thrust reverser and VAFN nozzle in their stowed positions.
[0024] FIG. 11 is a cross-sectional view of the portion of the
actuation system shown in FIG. 9 taken along line 11-11 and showing
the thrust reverser and VAFN nozzle in their stowed positions.
[0025] FIG. 12 is a cross-sectional view similar to that shown in
FIG. 10 with the thrust reverser in a deployed position and the
VAFN nozzle in the stowed position.
[0026] FIG. 13 is a cross-sectional view similar to that shown in
FIG. 11 with the thrust reverser in the stowed position and the
VAFN nozzle in a deployed position.
[0027] FIG. 14 is a schematic diagram showing the first embodiment
of a VAFN actuation system.
[0028] FIG. 15 is a cross section taken along line 15-15 in FIG.
14.
[0029] FIG. 16 is a perspective view of a portion of the VAFN
actuation system shown in FIG. 14.
[0030] FIG. 17 is a perspective view of one embodiment of an
actuator for use in the VAFN actuation system shown in FIGS.
9-15.
[0031] FIG. 18 is a perspective view of a portion of a second
embodiment of a VAFN actuation system for selectively translating a
variable area fan nozzle like that shown in FIGS. 1-8.
[0032] FIG. 19 is a schematic diagram showing the second embodiment
of a VAFN actuation system.
[0033] FIG. 20 is a perspective view of the second embodiment of a
VAFN actuation system shown in FIGS. 18-19.
[0034] FIG. 21 is a cross sectional view of an actuator portion of
the second embodiment of a VAFN actuation system showing a thrust
reverser in a deployed position and a VAFN nozzle in a stowed
position.
[0035] FIG. 22 is another cross sectional view of the actuator
portion of the second embodiment of a VAFN actuation system showing
the thrust reverser in a stowed position and the VAFN nozzle in a
deployed position.
[0036] FIG. 23 is a schematic diagram of a third embodiment of a
VAFN actuator system according to the invention.
DETAILED DESCRIPTION
[0037] FIGS. 1-8 show one embodiment of a translating variable area
fan nozzle assembly (VAFN) for a turbofan engine 10.
[0038] Referring to FIGS. 1 and 2, the engine 10 includes a
trailing edge fan nozzle assembly 12 having a translating nozzle 50
that can be selectively adjusted, for example, as the engine 10
operates under different flight conditions. As discussed above,
such an adjustment can be used to optimize an engine's performance.
As shown in FIG. 2, the translating nozzle 50 can be selectively
translated (i.e., moved fore and aft) to vary the fan nozzle's exit
area "A.sub.exit" in order to optimize engine performance, and as
described in detail below, to adjust an amount of engine bypass
flow spilled through an upstream exit 60 formed by the variable
area fan nozzle assembly 12. By bleeding or spilling off excess fan
flow through the upstream exit 60 before the excess air flow
reaches the primary fan nozzle exit 52, lower fan pressure ratios
for the same amount of delivered mass flow can be obtained, thereby
increasing stall margins and avoiding engine malfunction and
shutdown. For purposes of illustration, the variable area fan
nozzle assembly 12 is shown in the context of a turbofan jet
aircraft engine 10. The engine 10 can be mounted to a wing or
fuselage of an aircraft, for example, by a pylon or other similar
support (not shown in the figures).
[0039] As shown in FIG. 2, the engine 10 includes an engine core 16
and a stationary nacelle 18 surrounding the core 16. The engine
core 16 is housed within a core cowl 19. The engine's fan 20 is
positioned within an upstream portion of the nacelle 18, and
includes a plurality of fan blades 22 that are mounted on the
engine's rotor (not shown). The fan blades 22 rotate about the
engine's centerline C.sub.L and draw a flow of air into an inlet
end 26 of the engine 10. An annular bypass duct 24 is defined
between the engine core 16 and the nacelle 18. The air flow drawn
into the engine 10 is accelerated by the rotating fan blades 22,
and a portion of the incoming air flow is directed into and through
the engine core 16.
[0040] Bypass flow enters the upstream end of the nacelle 18 and
flows around and past the engine core 16. The bypass flow is
accelerated by the rotating fan blades 22 and passes through the
bypass duct 24 and past stators 40, and exits the engine 10 through
the variable area fan nozzle assembly 12. The high-pressure heated
exhaust gases from the combustion of the fuel and air mixture exit
the engine core 16 through a primary exhaust nozzle 13 at the aft
end of the engine 10.
[0041] In the engine assembly 10 shown in FIGS. 1-8, the
translating nozzle 50 is a nozzle-like annular airfoil structure
mounted at the trailing end of a cascade-type thrust reverser 80
that circumscribes the engine core cowl 19 immediately aft of the
nacelle 18. As shown in FIG. 2, a downstream nozzle exit 52 between
the trailing edge of the fan nozzle 50 and the core cowl 19 defines
a fan nozzle exit area "A.sub.exit". Due to the longitudinal
variations in the diameter of the core cowl 19, selective fore and
aft movement of the translating nozzle 50 changes the size of the
fan nozzle exit area A.sub.exit. As shown in FIG. 1, the fan nozzle
50 can include a first arcuate nozzle section 54 and a second
arcuate nozzle section 56, each nozzle section 54, 56 being axially
translatable in the direction of the bidirectional arrow 58.
Translation of the translating nozzle 50 effects a desired size of
the upstream exit 60 (shown in FIG. 2), and also varies the outlet
geometry and effective exit area A.sub.exit of the downstream
nozzle exit 52. Hence, when the translating nozzle 50 is deployed,
there is an increase in the bypass flow that is discharged from the
engine assembly 10 through both the upstream exit 60 and the
enlarged downstream nozzle exit 52. As shown in FIGS. 1-3, the
translating nozzle 50 can be selectively translated fore and aft by
a plurality of linear nozzle actuators 70, for example.
[0042] The cascade-type thrust reverser 80 can be positioned
forward of the translating nozzle 50 in order to selectively block
and redirect bypass flow from the bypass duct 24 in a manner known
in the art. In FIG. 1, the thrust reverser 80 and the translating
nozzle 50 are both in their stowed positions. As shown in FIG. 3,
the thrust reverser 80 can include a first arcuate sleeve section
82 and an opposed second arcuate sleeve section 84. As indicated by
bi-directional arrow 86 in FIG. 1, the thrust reverser sleeve
sections 82, 84 can be translated in the fore and aft directions by
a plurality of spaced sleeve actuators 90. In a stowed position,
the thrust reverser sleeve sections 82, 84 cover an array of
cascade vanes 88. The cascade vanes 88 are indicated by dashed lead
lines in FIG. 1 because they are not visible when the thrust
reverser 80 is in its stowed position. Axial translation of the
thrust reverser sleeve sections 82, 84 in the aft direction to a
deployed position and deployment of a series of blocker doors 134
(as indicated by directional arrow 136 in FIG. 8) within the bypass
duct 24 causes bypass air flow to exit the bypass duct 24 through
the cascade vanes 88 which turn the exiting flow in a generally
forward direction to create reverse thrust.
[0043] FIG. 3 is a partial section view of the aft end of engine
10, and illustrates one arrangement of the nozzle and sleeve
actuators 70, 90, respectively, around the periphery of the engine
10. As shown in FIG. 1, and more clearly in FIG. 3, the sleeve half
section 82 and the nozzle half-section 54 cooperate to generally
define an approximately 180-degree sector of the combined thrust
reverser and translating nozzle structure. Likewise, sleeve half
section 84 and nozzle half section 56 cooperate to generally define
an opposed approximately 180-degree sector of the thrust reverser
and translating nozzle structure. Together, these approximate
180-degree sectors cooperate to define the complete thrust
reverser/translating nozzle structure.
[0044] As shown in FIGS. 1-3, the thrust reverser sleeve sections
82, 84 can each be selectively translated in the fore and aft
directions by one or more circumferentially spaced sleeve actuators
90 that are connected to the nacelle 18. In the embodiment shown,
three actuators 90 are used for each sleeve half-section 82, 84. As
discussed above, each section 54, 56 of the translating nozzle 50
can be selectively translated by one or more circumferentially
spaced nozzle actuators 70. In the embodiment shown, each nozzle
actuator 70 is disposed between a thrust reverser sleeve section
82, 84 and a respective fan nozzle section 54, 56. The sleeve
actuators 90 and the nozzle actuators 70 can be electrical,
mechanical, pneumatic, hydraulic, or the like, and can be
interconnected by appropriate power cables and conduits (not
shown). The number and arrangement of nozzle and sleeve actuators
70, 90 can vary according to the thrust reverser and nozzle
assembly configurations or other factors. As shown in FIG. 3, the
nozzle sections 54, 56 can be movably mounted on the engine 10 by
upper and lower track beam assemblies 102. (FIG. 7 shows a detail
view of one embodiment of a track beam assembly 102.) As shown in
FIGS. 1-3, guide tubes 104 can be mounted to the nacelle 18, and
can extend into the nozzle sections 54, 56 to stabilize the nozzle
sections 54, 56 against undesirable translation and/or vibration.
In addition or alternatively, guide tubes can be used to stabilize
the thrust reverser sleeves 82, 84.
[0045] The translating nozzle 50 can be a continuous nozzle (not
shown in the figures), or as shown in FIG. 3, can include two or
more arcuate nozzle sections having airfoil profiles. The upstream
exit 60 shown in FIG. 2 is formed when the translating nozzle 50 is
deployed in the aft direction away from the thrust reverser sleeve
sections 82, 84, and can have the form of a generally circular
annular gap. Alternatively, the upstream exit 60 can have other
non-circular shapes. The gap 60 between the nozzle sections 54, 56
and the sleeve sections 82, 84 can be continuous, or can be
interrupted at one or more locations, such as, for example, at
points of separation between nozzle segments 54, 56 of the
translating nozzle 50. As shown in FIGS. 2-3, the bypass duct 24
can be interrupted at one or more locations by one or more stators
40, or the like.
[0046] The translating nozzle 50 and surrounding structure are
described below with reference to FIGS. 4-7. In FIGS. 4-7, elements
that are obscured or partially obscured due to intervening elements
are indicated by dashed lead lines.
[0047] FIG. 4 is a partial view of one embodiment of a mounting
structure for a first nozzle section 54 of the translating nozzle
50 and the corresponding, adjacent first sleeve section 82 of the
thrust reverser 80. The second nozzle section 56 of the translating
nozzle 50 and the second sleeve section 84 of the thrust reverser
80, which are shown in FIGS. 1 and 3, can be mounted in a similar
manner (not shown). In FIG. 4, the thrust reverser 80 is in a
stowed position, and the first sleeve section 84 covers an
associated portion of the cascade vanes 88. Also in FIG. 4, the
translating nozzle 50 is in an open or deployed position, and the
upstream exit 60 is disposed between the first nozzle section 54
and the first sleeve section 84. Rearward axial translation of the
first nozzle section 54 from its stowed position to its deployed
position is indicated in FIGS. 4-5 by directional arrow "X". As
shown in FIG. 4, the nozzle actuators 70 can extend from the sleeve
section 82 and across the upstream exit 60, and can connect to a
forward portion of the nozzle section 54. The guide tubes 104 can
also extend from the sleeve section 82 and across the upstream exit
60, and can connect to a forward portion of the nozzle section 54.
A flexible sleeve actuation shaft 96 can interconnect two or more
of the sleeve actuators 90 to power the actuators 90, and/or to
synchronize actuation of two or more actuators 90.
[0048] FIG. 5 shows the first thrust reverser sleeve section 82 and
the first translating nozzle section 54 in their deployed
positions. Rearward axial translation of the first sleeve section
82 from its stowed position (as shown in FIG. 4) to its deployed
position (as shown in FIG. 5) is indicated in FIG. 5 by directional
arrow "Y". Rearward translation of the sleeve section 82 exposes
the cascade vanes 88 during operation of the thrust reverser
80.
[0049] FIG. 6 is an exploded view showing the first sleeve section
82 and its corresponding first nozzle section 54 separated from the
cascades 88 and sleeve actuators 90. As shown in FIG. 6, one or
more nozzle actuators 70 can movably connect the nozzle section 54
to the thrust reverser sleeve section 82.
[0050] FIG. 7 shows one embodiment of the upper or lower track beam
assemblies 102 for movably connecting a thrust reverser segment 82
and a nozzle section 54 to an engine 10. Referring generally to
FIGS. 3 and 6 and particularly to FIG. 7, the track beam assembly
102 can include a beam 106 that can be fixedly attached to a torque
box 110 on an aft end of a nacelle 18. The beam 106 can include one
or more longitudinally extending guide tracks 108. A slide 103 can
include one or more longitudinally extending track bars 114 that
are slidably received within the guide tracks 108 of the fixed beam
106. The slide 103 is connected to the thrust reverser sleeve
section 82, and thereby slidably connects the sleeve section to the
beam 106. The slide 103 can also include an axially extending track
guide 116 in which a translating nozzle track bar 120 on the nozzle
section 54 is slidably received, thus slidably connecting the
nozzle section 54 to the nacelle 18. Accordingly, the nozzle
section 54 can axially translate as the track bar 120 slides within
the track guide 116. The nozzle section 54 is thereby slidably
mounted with respect to the sleeve section 82 of the thrust
reverser 80. The translating sleeve section 82 and the track bar
120 can be actuated through conventional actuation means, such as
mechanical, electric, hydraulic or pneumatic or other equivalent
actuators, for example.
[0051] FIG. 8 illustrates one method of operating the nozzle
section 54 to bleed or spill off excess bypass flow through the
upstream exit 60. As described above, the sizes of the upstream
exit 60 and the nozzle exit area A.sub.exit can be varied in order
to achieve different engine operating conditions. FIG. 8 shows a
partial section of a downstream portion of the nozzle assembly 12,
and shows a portion of the bypass air flow (indicated by curved
arrows) exiting the bypass duct 24 through the annular upstream
exit 60 in one mode of operation of the nozzle assembly 12. In FIG.
8, the first nozzle section 54 of the translating nozzle 50 is
rearwardly displaced from the first thrust reverser sleeve section
82 by its associated nozzle actuators 70. The second nozzle section
56 (shown in FIG. 3) can be similarly and simultaneously rearwardly
displaced from the second thrust reverser sleeve section 84 by its
associated nozzle actuators 70. As shown in FIG. 8, the thrust
reverser 80 can include a plurality of blocker doors 134 that are
pivotally connected to the first sleeve section 82 and swing in the
direction of the curved arrow 136 to selectively block and redirect
the bypass flow from the bypass duct 24 and through the cascade
vanes 88 during thrust reverser operation.
[0052] Still referring to FIG. 8, a high pressure seal 130 can be
disposed between the thrust reverser sleeve section 82 and the
first nozzle section 54, such as on the trailing edge of the sleeve
section 82, for example. In certain modes of operation, when the
sleeve section 82 and nozzle section 54 are drawn together, the
seal 130 can operate to substantially seal any gap between the
adjacent sleeve section 82 and nozzle section 54, and thereby
substantially prevent bypass air flow from passing between the
sleeve section 82 and nozzle section 54. Similarly, a seal 130 can
be disposed between the second thrust reverser sleeve section 84
and the second nozzle section 56. Alternatively, the seal 130 can
be mounted on the leading edges of the nozzle sections 54, 56, for
example.
[0053] FIGS. 9-17 show one embodiment of a VAFN actuation system
200 for selectively translating a variable area fan nozzle 50 like
that described above between its stowed and deployed positions. As
shown in FIG. 9, a thrust reverser 80 can include at least one
translating thrust reverser sleeve section 82 that is movably
mounted aft of a stationary nacelle portion 18. Fore and aft
translation of the thrust reverser sleeve section 82 can be
effected by a plurality of thrust reverser actuators 90 that
movably connect the sleeve section 82 to a torque box 110 on the
aft end of the nacelle portion 18. When the thrust reverser
actuators 90 are retracted, the thrust reverser sleeve section 82
is positioned immediately behind the torque ring 110 in a stowed
position, and sleeve section 82 covers the cascade array 88. A fan
nozzle segment 54 is movably disposed aft of the thrust reverser
sleeve section 82. The fan nozzle segment 54 and the thrust
reverser sleeve section 82 can be movably supported by a track beam
assembly 102 like that shown in FIG. 7, for example.
[0054] As shown in FIG. 9, a VAFN actuation system 200 according to
the invention can include one or more VAFN actuators 270. The VAFN
actuator 270 can generally include a gear box 271, a telescoping
coupling 273, and an extensible portion 277. The gear box 271 can
be mounted to the torque box 110. In the embodiment shown in FIG.
9, the gear box 271 is located proximate to the track beam assembly
102. The telescoping coupling 273 is rotatably coupled to the gear
box 271 and rearwardly extends between the gear box 271 and a jack
head 275. The jack head 275 can be positioned proximate to an aft
end of the thrust reverser sleeve segment 82, and can be coupled to
a bracket 283 on the sleeve segment 82. Accordingly, the jack head
275 moves with the thrust reverser sleeve segment 82 as the sleeve
segment 82 is moved between its stowed and deployed positions by
the thrust reverser actuator 90. The extensible portion 277 of the
VAFN actuator 270 is disposed between the jack head 275 and a
support 251 on the fan nozzle segment 54. As described below, the
extensible portion 277 is configured to move the fan nozzle segment
54 between its forward stowed position and its aft deployed
position. In the embodiment shown in FIG. 9, the extensible portion
277 and the telescoping coupling 273 are laterally offset from each
other due to an offset between the input and output of the jack
head 275.
[0055] FIGS. 10-11 show the telescoping coupling 273 and the
extensible portion 277 of the VAFN actuator 270 with both the
thrust reverser sleeve segment 82 and the fan nozzle segment 54 in
their stowed positions. As shown in FIG. 10, the telescoping
coupling 273 can include a non-translating portion 273a and a
movable portion 273b. In one embodiment, the non-translating
portion 273a is an elongated sleeve or tube, and the movable
portion 273b is an elongated shaft that is slidably received within
the sleeve 273a. In the embodiment shown, a forward end of the
sleeve 273a is rotatably coupled to the gear box 271, and an aft
end of the shaft 273b is rotatably coupled to the jack head 275. An
aft portion of the fixed sleeve 273a can be connected to an
adjacent stationary structure by a bracket 279 or another device.
Accordingly, the sleeve 273a remains stationary even as the thrust
reverser sleeve section 82 moves aft toward its deployed position.
As described below, the sleeve 273a and shaft 273b can be
configured such that they are rotatably coupled together yet permit
axial displacement of the shaft 273b within the sleeve 273a.
Accordingly, when the sleeve 273a is rotated by the gear box 271,
the shaft 273b also rotates. Though not shown in the figures, the
orientation of the telescoping coupling 273 can be reversed such
that an aft end of the sleeve 273a is rotatably coupled to the jack
head 275 and a forward end of the shaft 273b is rotatably coupled
to the gear box 271. As shown in FIG. 10, when the thrust reverser
sleeve section 82 is in its stowed position, a substantial portion
of the shaft 273b can be received within the sleeve 273a. Rotation
of the gear box 271 causes rotation of the sleeve 273a and shaft
273b, which in turn effect rotation of the jack head 275 and jack
screw 277a, thereby resulting in translation of the threaded sleeve
277b and the fan nozzle segment 54. The direction of rotation of
the gear box 271 dictates whether the threaded sleeve 277b and fan
nozzle segment 54 move in a forward or rearward direction.
[0056] As shown in FIG. 11, the extensible portion 277 of the VAFN
actuator 270 can include a jack screw 277a having a forward end
rotatably coupled to the jack head 275, and an internally threaded
sleeve 277b that is threadably engaged with the jack screw 277a and
includes an aft end 279 connected to a support 251 on the fan
nozzle segment 54. The connection between the aft end 279 and the
support 251 prevents rotation of the threaded sleeve 277b.
Accordingly, rotation of the jack screw 277a by the jack head 275
causes the sleeve 277b to translate in a fore or aft direction on
the jack screw 277a, thus causing associated displacement of the
attached fan nozzle segment 54.
[0057] FIG. 12 shows the telescoping coupling 273 of the actuator
270 with the thrust reverser sleeve section 82 in its deployed
position. In this position, the shaft 273b outwardly extends from
sleeve 273a, and at least a portion of the shaft 273b remains
engaged within the sleeve 273a. The gear box 271 remains rotatably
coupled to the jack head 275 by the telescoping coupling 273.
[0058] FIG. 13 shows the extensible portion 277 of the actuator 270
in an extended position, and the thrust reverser sleeve section 82
in its deployed position. When extended, the threaded sleeve 277b
displaces the fan nozzle segment 54 away from the torque box 110
and the thrust reverser sleeve section 82. At least a portion of
the sleeve 277b remains threadably engaged on the jack screw 277a
when the sleeve 277b is fully extended.
[0059] FIG. 14 is a schematic diagram of one embodiment of a VAFN
actuation system 200 that incorporates a plurality of VAFN
actuators 270 as described above. The actuation system 200 can be
used in a turbofan engine 10 having a cascade-type thrust reverser
80 like that previously described, and to translate one or more fan
nozzle segments 54, 56 between their stowed and deployed positions.
In the actuator system 200 shown schematically in FIG. 14, a pair
of translating thrust reverser sleeve sections 82, 84 are movably
disposed aft of a nacelle torque ring 110, and a pair of
translating fan nozzle segments 54, 56 are movably disposed aft of
the sleeve sections 82, 84. Each fan nozzle segment 54, 56 is
positioned in its stowed and deployed positions by one or more VAFN
actuators 270. Each VAFN actuator can include a gear box 271, a
telescoping coupling 273 having a non-translating portion 273a and
a movable portion 273b, a jack head 275, and an extensible portion
277 having an extensible sleeve 277b. The telescoping coupling 273
permits fore and aft movement of the thrust reverser sleeve
sections 82, 84 while maintaining rotational engagement between the
gear box 271 and the jack head 275. In this embodiment 200, the
longitudinal axes of the telescoping coupling 273 and the
extensible portion 277 are laterally offset from each other. This
offset permits the jack head 275 to be configured such that the
rotational speed and/or output torque provided to the extensible
portion 277 by the jack head 275 can be different than the
rotational speed and or torque provided to the jack head 275 by the
gear box 271 and the telescoping coupling 273.
[0060] The plurality of VAFN actuators 270 can be connected to a
power drive unit (PDU) 210. The PDU 210 can be affixed to an engine
pylon 900 represented by dashed lines in FIG. 14. Flexible drive
shafts 203 rotatably connect first gear boxes 271 to the PDU 210,
and flexible transmission shafts 205 rotatably connect gear boxes
271 not directly connected to the PDU. When actuated, the PDU 210
drives the shafts 203, 205 and interconnected gear boxes 271,
thereby simultaneously actuating the VAFN actuators 270 and
effecting desired simultaneous movement of the fan nozzle segments
54, 56 in a forward or aft direction. The telescoping couplings 273
are configured to couple the jack screws 277a to the PDU 210 while
also accommodating substantial translational displacement between
the input ends of the jack screws 277a and the power drive unit
210. Other means can also be used to couple the jack screws 277a to
the PDU 210 in a manner that permits substantial translational
displacement between the input ends of the jack screws 277a and the
power drive unit 210.
[0061] As described above, the shafts 273b of the telescoping
couplings 273 can be slidably received within their respective
sleeves 273a while also being rotatably coupled to the sleeves
273b. One configuration of the sleeves 273a and shafts 273b that
permits sliding movement and provides rotational coupling is shown
in FIG. 15. In this configuration, at least a portion of each shaft
273b can include a plurality of circumferentially-spaced ridges or
splines 291. The mating sleeves 273a can each include a plurality
of circumferentially-spaced longitudinal grooves 293 that extend
along a substantial portion of the length of the sleeve 273a. When
the splines 291 are engaged with the grooves 293, each shaft 273b
is substantially free to move longitudinally within its mating
sleeve 273a, but is restrained against substantial rotation
relative to its respective sleeve 273a. Accordingly, the
telescoping couplings 273 accommodate movement of the fan nozzle
segments 54, 56 with the thrust reverser sleeve sections 82, 84
when the thrust reverser sleeve segments are deployed while also
maintaining rotational coupling between the stationary gear boxes
271 and displaced jack heads 275.
[0062] FIG. 16 shows an isolated portion of the VAFN actuation
system 200. Though the actuation system 200 can include two
actuators 270 on each side of the PDU 210 (only one side is shown
in FIG. 16), the system 200 can alternatively include a single
actuator 270 or more than two actuators 270 on either side. FIG. 17
shows one embodiment of an actuator 270 for use in the VAFN
actuation system 200 described above. In FIG. 17, the telescoping
coupling 273 and the extensible portion 277 are both shown in their
fully extended positions. In the configuration shown, the positions
of the sleeve 273a and the shaft 273b can be reversed, if desired.
In addition or alternatively, the positions of the jack screw 277a
and threaded sleeve 277b can be reversed from that shown in FIG.
17.
[0063] Another embodiment of a VAFN actuation system 300 according
to the invention is shown in FIGS. 18-22. This embodiment 300 can
be substantially similar to the VAFN system 200 described above
except for the differences described below. As shown in FIG. 18, a
thrust reverser 80 can include at least one translating thrust
reverser sleeve section 82 that is movably mounted aft of a torque
ring 110 of a stationary nacelle portion 18. When the thrust
reverser sleeve section 82 is in the stowed position shown in FIG.
18, the sleeve section 82 is positioned immediately aft of the
torque ring 110, and the sleeve section 82 covers the cascade array
88. A fan nozzle segment 54 is movably disposed aft of the thrust
reverser sleeve section 82. The fan nozzle segment 54 and the
thrust reverser sleeve section 82 can be movably supported by a
track beam assembly 102 like that shown in FIG. 7, for example.
[0064] As shown in FIG. 18, one embodiment of a VAFN actuation
system 300 according to the invention can include one or more VAFN
actuators 370. The VAFN actuator 370 can generally include a gear
box 371, a telescoping coupling 373, and an extensible portion 377.
The gear box 371 can be mounted to the nacelle's stationary torque
box 110, for example. In the embodiment shown in FIG. 18, the gear
box 371 is located proximate to the track beam assembly 102. The
telescoping coupling 373 is rotatably coupled to the gear box 371
and rearwardly extends between the gear box 371 and an inline
coupling 374. The inline coupling 374 can be positioned proximate
to an aft end of the thrust reverser sleeve segment 82, and can be
connected to the sleeve segment 82 by a bracket 379. Accordingly,
the inline coupling 374 moves with the thrust reverser sleeve
segment 82 as the sleeve segment 82 is moved between its stowed and
deployed positions. The extensible portion 377 of the VAFN actuator
370 is disposed between the inline coupling 374 and a support 351
on the fan nozzle segment 54. As described below, the extensible
portion 377 is configured to move the fan nozzle segment 54 between
its forward stowed position and its aft deployed position. In the
embodiment shown in FIG. 18, the extensible portion 377 and the
telescoping coupling 373 are axially aligned with each other.
[0065] FIG. 19 is a schematic diagram of one embodiment of the VAFN
actuation system 300 that incorporates a plurality of VAFN
actuators 370 as described above. The actuation system 300 can be
used in a turbofan engine 10 having a cascade-type thrust reverser
80 like that previously described, and to translate one or more fan
nozzle segments 54, 56 between their stowed and deployed positions.
In the actuator system 300 shown schematically in FIG. 19, a pair
of translating thrust reverser sleeve sections 82, 84 are movably
disposed aft of a nacelle 18 and torque ring 110, and a pair of
translating fan nozzle segments 54, 56 are movably disposed aft of
the sleeve sections 82, 84. Each fan nozzle segment 54, 56 is
positioned in its stowed and deployed positions by one or more VAFN
actuators 370. Each VAFN actuator can include a gear box 371, a
telescoping coupling 373 having a non-translating portion 373a and
a movable portion 373b, an inline coupling 374, and an extensible
portion 377 having an extensible sleeve 377b. The telescoping
coupling 373 permits fore and aft movement of the thrust reverser
sleeve sections 82, 84 while maintaining rotational engagement
between the gear box 371 and the inline coupling 374. In this
embodiment 300, the longitudinal axes of the telescoping coupling
373 and the extensible portion 377 are axially aligned, and the
coupling 373 and extensible portion 377 are directly connected
together without any intervening gears or transmission.
Accordingly, the rotational speed and/or output torque provided to
the extensible portion 377 by the inline coupling 374 is
substantially the same as the rotational speed and/or torque
provided to the coupling 374 by the gear box 371 and the
telescoping coupling 373.
[0066] As shown in FIG. 19, the VAFN actuators 370 can be connected
to a power drive unit (PDU) 310. Flexible drive shafts 303 can
rotatably connect adjacent gear boxes 371 to the PDU 310, and
flexible transmission shafts 305 can rotatably connect gear boxes
371 that are not directly connected to the PDU 310. The PDU 310 can
include a power gear box 312 driven by a motor 314. When actuated,
the PDU 310 drives the shafts 303, 305 and interconnected gear
boxes 371, thereby simultaneously actuating the VAFN actuators 370
and effecting desired simultaneous movement of the fan nozzle
segments 54, 56 in a forward or aft direction. The non-translating
portion 373a and the movable portion 373b of the actuators 370 can
be rotatably coupled together by a splined configuration similar to
that shown in FIG. 15.
[0067] FIG. 19 also shows a schematic representation of a control
system for use with a VAFN actuation system 300. In the embodiment
shown, one or more linear variable displacement transducers (LVDTs)
320 can be positioned to detect the positions of the fan nozzle
segments 54, 56 relative to the nacelle 18 and torque box 110,
and/or to the thrust reverser sleeve segments 82, 84. The LVDTs 320
can be connected to an automatic control system 399 that controls
operation of the PDU 310. For example, the LVDTs 320 can be
operably connected to a Full Authority Digital Engine Control
(FADEC) system. Inputs from the LVDTs 320 can be used by the
control system 399 to determine when the fan nozzle segments 54, 56
are in there fully stowed or fully deployed positions, for example,
and to control operation of the PDU 310 accordingly. Alternatively
or in addition, the PDU 310 can be equipped with one or more rotary
variable displacement transducers (RVDTs) 301 to detect when
predetermined rotational displacement limits for the PDU 310 have
been reached.
[0068] FIG. 20 shows the VAFN actuation system 300 separated from
an associated thrust reverser 80 and fan nozzle assembly 50. Though
the actuation system 300 can include two actuators 370 on each side
of the PDU 310 as shown in FIGS. 19-20, the system 300 can
alternatively include a single actuator 370 or more than two
actuators 370 on either side.
[0069] FIG. 21 shows a VAFN actuator 370 and an associated thrust
reverser sleeve section 82 in its deployed position. In the
configuration shown in FIG. 21, a shaft 373a is coupled to the gear
box 371, and a mating extendable sleeve 373b is connected to the
coupling 374. When the thrust reverser sleeve 82 is deployed, the
sleeve 373b of the actuator 370 rearwardly extends from the mating
shaft 373a, and at least a portion of the sleeve 373b remains
engaged on the shaft 373a. The gear box 371 remains rotatably
connected to the inline coupling 374 by the telescoping coupling
373.
[0070] FIG. 22 shows the extensible portion 377 of the actuator 370
in an extended position, and the fan nozzle segment 54 in a
deployed position. When extended, the threaded sleeve 377b
displaces the fan nozzle segment 54 away from the torque ring 110
and the thrust reverser sleeve section 82. At least a portion of
the threaded sleeve 377b remains threadably engaged on the jack
screw 377a when the sleeve 377b is fully extended.
[0071] Another embodiment of a VAFN actuation system 400 according
to the invention is shown schematically in FIG. 23. The actuation
system 400 can be used in a turbofan engine having a cascade-type
thrust reverser 80 like that previously described, and to translate
one or more fan nozzle segments 54, 56 between their stowed and
deployed positions. In the actuator system 400 shown schematically
in FIG. 23, a pair of translating thrust reverser sleeve sections
82, 84 are movably disposed aft of a nacelle 18 and torque ring
110, and a pair of translating fan nozzle segments 54, 56 are
movably disposed aft of the sleeve sections 82, 84. Each fan nozzle
segment 54, 56 is positioned in its stowed and deployed positions
by the VAFN actuator system 400. In this embodiment, a PDU 410 can
include a gear box 520 driven by a motor 516. The motor 516 can be
hydraulic, electric, pneumatic, or the like. The PDU gear box 520
is rotatably coupled to a pair of actuator gear boxes 486 by
flexible drive shafts 485. Each actuator gear box 486 is rotatably
coupled to a transmission 488 by a telescoping coupling 473. The
telescoping couplings 473 can be like the telescoping couplings
273, 373 described above, for example. Two or more extensible
actuators 577 are rotatably coupled to each transmission 488 by
actuator shafts 490. The actuators 577 can each include a jack head
508, a jack screw 506, and a translating threaded sleeve 504
connected to a fan nozzle segment 54, 56. The telescoping couplings
473 permit translation of the thrust reverser sleeve segments 82,
84 while maintaining rotational engagement between the actuator
gear boxes 486 and the transmissions 488 and extensible actuators
577. Rotation of the actuator gear boxes 486 by the PDU 410 results
in rotation of the telescoping couplings 473 and the transmissions
488. The transmissions 488 in turn drive the actuators 577, which
effect desired displacement of the fan nozzle segments 54, 56. The
system 400 can include one or more LVDTs 450 and/or one or more
RVDTs 452 to provide control feedback to a control processor 540
for use in controlling operation of the PDU 410.
[0072] Persons of ordinary skill in the art will understand that
while the invention has been described in terms of various
embodiments and various aspects and features, certain
modifications, variations, changes and additions can be made to the
described embodiments without departing from the spirit and scope
of the invention. All such modifications, variations, changes and
additions are intended to be within the scope of the appended
claims.
* * * * *