Field of the Invention
[0001] The present invention relates to gas turbine engines, and more particularly, to gas
turbine engines with variable camber vane systems.
Background
[0002] Gas turbine engines with variable camber vane systems remain an area of interest.
Some existing systems have various shortcomings, drawbacks, and disadvantages relative
to certain applications. Accordingly, there remains a need for further contributions
in this area of technology.
[0003] Document
EP 0 924 389 A2 describes an inlet guide vane having a gap, in which an inlet guide vane seal is
located. The seal has a longitudinally extending tubular portion and a dovetail portion,
wherein a longitudinal axis extends the length of the tubular portion, and wherein
the tubular portion and the dovetail portion are made of an elastomeric material,
such as silicone rubber. A trailing edge of the strut airfoil includes a retaining
slot that tapers in a direction away from the leading edge of the strut airfoil, wherein
the slot extends the length of the trailing edge, and dovetail portion must be slid
into the slot from one of the ends of the strut airfoil. The width of the slot is
only slightly greater than the width of the retaining feature of the dovetail portion.
[0004] In document
DE 103 52 789 A1, a gas turbine having a pre-vane and pre-guiding element is described, wherein the
pre-vane can be pivoted about an axis arranged radially, and wherein the pre-guiding
element is formed fixedly. For sealing a gap between a face of the pre-guiding element
and an upstream end of the pivotable pre-vane, a sealing device formed as a brush
seal integrated in the pre-vane is provided.
[0005] Document
US 3 990 810 A describes a vane assembly in which a variable vane is disposed immediately adjacent
in nested relationship with a concave surface on a trailing edge of a stationary vane.
A seal pin is disposed in a radial groove provided in the concave face of the stationary
vane to prevent leakage between the nested interface of the stationary vane and the
variable vane.
[0006] From document
GB 1 504 463 A, an adjustable vane assembly is known, in which a gas seal is inserted into slots
of two vanes of an assembly during its assembly.
Summary
[0007] The present invention relates to a unique variable camber vane system for a gas turbine
engine according to claim 1. Moreover, a unique gas turbine engine is disclosed.
Brief Description of the Drawings
[0008] The description herein makes reference to the accompanying drawings wherein like
reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 schematically depicts some aspects of a non-limiting example of a gas turbine
engine in accordance with an embodiment of the present invention.
FIG. 2 schematically depicts some aspects of a non-limiting example of a fan system
for a gas turbine engine in accordance with an embodiment of the present invention.
FIG. 3 depicts some aspects of a non-limiting example of a variable camber guide vane
system in accordance with an embodiment of the present invention.
FIG. 4 depicts some aspects of the variable camber guide vane system of FIG. 3.
FIG. 5 depicts some aspects of a non-limiting example of a seal strip in accordance
with an embodiment of the present invention.
Detailed Description
[0009] For purposes of promoting an understanding of the principles of the invention, reference
will now be made to the embodiments illustrated in the drawings, and specific language
will be used to describe the same. It will nonetheless be understood that no limitation
of the scope of the invention is intended by the illustration and description of certain
embodiments of the invention. In addition, any alterations and/or modifications of
the illustrated and/or described embodiment(s) are contemplated as being within the
scope of the present invention. Further, any other applications of the principles
of the invention, as illustrated and/or described herein, as would normally occur
to one skilled in the art to which the invention pertains, are contemplated as being
within the scope of the present invention which is only defined by the appended claims.
[0010] Referring to the drawings, and in particular FIG. 1, a non-limiting example of a
gas turbine engine 10 in accordance with an embodiment of the present invention is
depicted. In one form, gas turbine engine 10 is an aircraft propulsion power plant.
In other embodiments, gas turbine engine 10 may be a land-based or marine engine.
In one form, gas turbine engine 10 is a multi-spool turbofan engine. In other embodiments,
gas turbine engine 10 may be a single or multi-spool turbofan, turboshaft, turbojet,
turboprop gas turbine or combined cycle engine.
[0011] Gas turbine engine 10 includes a fan system 12, a compressor system 14, a diffuser
16, a combustion system 18 and a turbine system 20. Compressor system 14 is in fluid
communication with fan system 12. Diffuser 16 is in fluid communication with compressor
system 14. Combustion system 18 is fluidly disposed between compressor system 14 and
turbine system 20. Fan system 12 includes a fan rotor system 22. In various embodiments,
fan rotor system 22 includes one or more rotors (not shown) that are powered by turbine
system 20. Compressor system 14 includes a compressor rotor system 24. In various
embodiments, compressor rotor system 24 includes one or more rotors (not shown) that
are powered by turbine system 20. Turbine system 20 includes a turbine rotor system
26. In various embodiments, turbine rotor system 26 includes one or more rotors (not
shown) operative to drive fan rotor system 22 and compressor rotor system 24. Turbine
rotor system 26 is driving coupled to compressor rotor system 24 and fan rotor system
22 via a shafting system 28. In various embodiments, shafting system 28 includes a
plurality of shafts that may rotate at the same or different speeds and directions.
In some embodiments, only a single shaft may be employed.
[0012] During the operation of gas turbine engine 10, air is drawn into the inlet of fan
12 and pressurized by fan 12. Some of the air pressurized by fan 12 is directed into
compressor system 14, and the balance is directed into a bypass duct (not shown).
Compressor system 14 further pressurizes the air received from fan 12, which is then
discharged into diffuser 16. Diffuser 16 reduces the velocity of the pressurized air,
and directs the diffused airflow into combustion system 18. Fuel is mixed with the
pressurized air in combustion system 18, which is then combusted. In one form, combustion
system 18 includes a combustion liner (not shown) that contains a continuous combustion
process. In other embodiments, combustion system 18 may take other forms, and may
be, for example, a wave rotor combustion system, a rotary valve combustion system,
or a slinger combustion system, and may employ deflagration and/or detonation combustion
processes. The hot gases exiting combustor 18 are directed into turbine system 20,
which extracts energy in the form of mechanical shaft power to drive fan system 12
and compressor system 14 via shafting system 28. The hot gases exiting turbine system
20 are directed into a nozzle (not shown), and provide a component of the thrust output
by gas turbine engine 10.
[0013] Referring to FIG. 2, a non-limiting example of some aspects of fan system 12 in accordance
with an embodiment of the present invention is schematically depicted. Fan system
12 includes a variable guide vane system 40 having a variable inlet guide vane stage
42 and a variable outlet guide vane stage 44 disposed on either side of a rotating
fan stage 46. Variable inlet guide vane stage 42 is operative to guide air into rotating
fan stage 46, and to selectively vary the incidence angle of the air flow entering
rotating fan stage 46. Variable outlet guide vane stage 44 is operative to guide air
exiting rotating fan stage 46, and to selectively vary the incidence angle of the
air flow exiting rotating fan stage 46. Variable inlet guide vane stage 42 and variable
outlet guide vane stage 44 are actuated by an actuation system (not shown). Although
described herein as with respect to fan system 12, it will be understood that variable
guide vane system 40 may also or alternatively be employed as part of compressor system
14. In addition, although variable guide vane system 40 includes both variable inlet
and outlet guide vane stages, other embodiments may include only a variable inlet
guide vane stage or a variable outlet guide vane stage.
[0014] Referring to FIGS. 3-5, a non-limiting example of some aspects of variable inlet
guide vane stage 42 in accordance with an embodiment of the present invention is illustrated.
It will be understood that some embodiments of variable outlet guide vane stage 44
may be similar to variable inlet guide vane stage 42, and hence, the following description
of variable inlet guide vane stage 42 is also applicable to aspects of some embodiments
of variable outlet guide vane stage 44. Variable inlet guide vane stage 42 includes
an outer band 50, an inner band 52 and plurality of vanes 54. Outer band 50 defines
an outer flowpath wall of variable inlet guide vane stage 42. Inner band 52 defines
an inner flowpath wall of variable inlet guide vane stage 42. Vanes 54 are airfoils
that extend between outer band 50 and inner band 52, and are spaced apart circumferentially.
In one form, vanes 54 extend in the radial direction between outer band 50 and inner
band 52. In other embodiments, vanes 54 may extend between outer band 50 and inner
band 52 at other angles.
[0015] Each vane 54 includes an airfoil portion 56 and an airfoil portion 58. Airfoil portion
56 extends between a tip portion 60 and a root portion 62. In one form, airfoil portion
56 includes the trailing edge 64 of vane 54. In other embodiments, airfoil portion
56 may be formed with a leading edge of vane 54 instead of trailing edge 64, e.g.,
for use in variable outlet guide vane 44. Airfoil portion 58 extends between a tip
portion 66 and a root portion 68. In one form, airfoil portion 58 includes the leading
edge 70 of vane 54. In other embodiments, airfoil portion 58 may be formed with a
trailing edge instead of leading edge 70, e.g., for use in variable outlet guide vane
44. In one form, airfoil portion 56 is fixed, i.e., stationary. In other embodiments,
airfoil portion 56 may be movable, e.g., pivotable about an axis so as to be able
to vary the angle of the trailing edge of vane 54. In one form, airfoil portion 58
is variable, being configured to pivot about a pivot axis 72 with respect to airfoil
portion 56, to provide a variable camber for vane 54. In other embodiments, airfoil
portion 58 may be fixed. In one form, airfoil portion 58 is coupled to an actuation
system (not shown) that is operative to selectively position airfoil portion 58 at
a desired incidence angle. In other embodiments, airfoil portion 56 may also or alternatively
be coupled to an actuation system (not shown) that is operative to selectively position
airfoil portion 56 at a desired incidence angle.
[0016] Extending from airfoil portion 58 are pivot shafts 74 and 76, which establish pivot
axis 72. Outer band 50 includes a plurality of spaced apart openings 78. Inner band
52 includes a plurality of spaced apart openings 80. Openings 78 and 80 are operative
to receive pivot shafts 74 and 76, respectively, and retain airfoil portions 58 in
the engine axial, circumferential and radial direction. In one form, pivot shafts
74 and 76 retain airfoil portion 58 in outer band 50 and inner band 52 via anti-friction
bushings 82 and 84. Anti-friction bushings 82 and 84 are operative to provide bearing
surfaces for pivot shafts 74 and 76. Other embodiments may not include anti-friction
bushings 82 and 84. Airfoil portion 58 is operative to rotate in rotation directions
86 about pivot axis 72.
[0017] During the operation of engine 10, air flows past vanes 54 in the general direction
illustrated as direction 88. Vane 54 has a pressure side 90 and a suction side 92,
wherein the pressure on pressure side 90 exceeds that of suction side 92. The pressure
differential between pressure side 90 and suction side 92 may vary, e.g., depending
upon vane 54 camber and engine operating conditions. The pressure differential between
pressure side 90 and suction side 92 provides an impetus to flow from pressure side
90 to suction side 92, e.g., between airfoil portion 56 and airfoil portion 58. It
is desirable to reduce or prevent leakage between airfoil portion 56 and airfoil portion
58, e.g., leakage flow from pressure side 90 to suction side 92, e.g., in order to
improve fan 12 and engine 10 efficiency. Accordingly, vanes 54 include a sealing arrangement
94 operative to seal between airfoil portion 56 and airfoil portion 58. Sealing arrangement
94 includes a seal strip 96 arranged to seal against fluid flow between airfoil portion
56 and airfoil portion 58 during the operation of engine 10, and to accommodate movement
of one or both of airfoil portions 56 and 58, e.g., rotation of airfoil portion 58
about pivot axis 72, while sealing against fluid flow.
[0018] In one form, seal strip 96 is a rigid structure that does not substantially deform
in use or installation. In other embodiments, seal strip 96 may be a flexible structure.
In one form, seal strip 96 is formed of a polymeric material, such as Vespel® (commercially
available from DuPont Engineering Polymers, located in Newark, Delaware, U.S.A.) and/or
Torlon® polyamide-imide (commercially available from Solvay Advanced Polymers, located
in Alpharetta, Georgia, U.S.A.). In other embodiments, seal strip 96 may be formed
of other materials. In one form, seal strip 96 is disposed in a groove 98. In one
form, groove 98 is disposed in a face 100 of airfoil portion 56 that faces airfoil
portion 58. In one form, seal strip 96, groove 98 and face 100 extend between tip
portion 60 and root portion 62 of airfoil portion 56. In other embodiments, seal strip
96, groove 98 and/or face 100 may extend only partially between tip portion 60 and
root portion 62. Face 100 is formed with a radius 102 centered on pivot axis 72. In
one form, face 100 is formed integrally with airfoil portion 56. In other embodiments,
face 100 may be formed separately and affixed to airfoil portion 56. In one form,
seal strip 96 is partially installed in groove 98, that is, leaving a portion 108
of seal strip 96 extending beyond face 100 of airfoil portion 56. Seal strip 96 has
a width 104 greater than a width 106 of groove 98, and is installed into groove 98
with an interference fit, e.g., 25.4-50.8µm (0.001-0.002 inch). The amount of interference
may vary with the needs of the application.
[0019] Airfoil portion 58 includes a crown 110 facing face 100 of airfoil portion 56. In
one form, crown 110 is formed integrally with airfoil portion 58. In other embodiments,
crown 110 may be formed separately and affixed to airfoil portion 58. Crown 110 is
formed with a radius 112 centered on pivot axis 72. In one form, crown 110 extends
between tip portion 66 and root portion 68 of airfoil portion 58, and is positioned
opposite groove 98. In other embodiments, crown 110 may extend only partially between
tip portion 66 and root portion 68. In one form, face 100 of airfoil portion 56 is
concave, and is operative to receive therein crown 110 opposite groove 98 in a nested
arrangement. In other embodiments, face 100 may be convex. In one form, crown 110
of airfoil portion 58 is convex, and is operative to be received into face 100 in
a nested arrangement. In other embodiments, crown 110 may be convex, e.g., an inverted
crown.
[0020] Seal strip 96 includes a rubbing surface 114. In one form, rubbing surface 114 is
disposed opposite radius 112 of crown 110, and is operative to contact and seal against
radius 112 of crown 110 of airfoil portion 58. During movement of airfoil portion
58, e.g., when changing the camber of vane 54 by rotating airfoil portion 58 about
pivot axis 72, rubbing surface 114 may rub against crown 110, e.g., until wear of
seal strip 96 resulting from rotation of airfoil portion 58 reduces or eliminates
contact between seal strip 96 and crown 110. In other embodiments, rubbing surface
114 may be configured to be in close proximity to crown 110, but without any rubbing
contact.
[0021] Rubbing surface 114 is preformed prior to installation into airfoil portion 56, e.g.,
machined. In one form, rubbing surface 114 is configured as a radius 116 centered
about pivot axis 72, e.g., the same radius as radius 112 of crown 110. According to
the invention, the rubbing surface 114 is concave.
[0022] While the invention has been described in connection with what is presently considered
to be the most practical and preferred embodiment, it is to be understood that the
invention is not to be limited to the disclosed embodiment(s). Furthermore it should
be understood that while the use of the word preferable, preferably, or preferred
in the description above indicates that feature so described may be more desirable,
it nonetheless may not be necessary and any embodiment lacking the same may be contemplated
as within the scope of the invention, that scope being defined by the claims that
follow. In reading the claims it is intended that when words such as "a," "an," "at
least one" and "at least a portion" are used, there is no intention to limit the claim
to only one item unless specifically stated to the contrary in the claim. Further,
when the language "at least a portion" and/or "a portion" is used the item may include
a portion and/or the entire item unless specifically stated to the contrary.
1. A variable camber vane system for a gas turbine engine (10), comprising:
a first airfoil portion (56) having a first tip portion (60), a first root portion
(62), a face (100) extending at least partially between the first tip portion (60)
and the first root portion (62), and a groove (98) in the face (100) extending at
least partially between the first tip portion (60) and the first root portion (62),
wherein the groove (98) has a groove width (106);
a second airfoil portion (58) arranged to rotate with respect to the first airfoil
portion (56) about a pivot axis (72), wherein the second airfoil portion (58) includes
a second tip portion (66); a second root portion (68); and a crown (110) extending
at least partially between the second tip portion (66) and the second root portion
(68), wherein the crown (110) includes a crown radius (112) centered about the pivot
axis (72) and positioned opposite the groove (98); and
a seal strip (96) having a seal width (104) greater than the groove (98) width and
a concave rubbing surface (114), the rubbing surface (114) being preformed prior to
installation into the first airfoil portion (56) to have a radius (116) complementary
to and opposite the crown radius (112),
wherein the seal strip (96) is at least partially disposed in the groove (98) with
an interference fit; and wherein the seal strip (96) is arranged to seal against fluid
flow between the first airfoil portion (56) and the second airfoil portion (58).
2. The variable camber vane system of claim 1,
wherein the rubbing surface (114) has a rubbing surface radius (116) the same as the
crown radius (112).
3. The variable camber vane system of claim 1,
wherein the crown (110) is formed integrally with the second airfoil portion (58);
or wherein the face (100) is formed integrally with the first airfoil portion (56);
or wherein the face (100) is concave and operative to receive the crown (110) therein.
4. The variable camber vane system of claim 1,
wherein the first airfoil portion (56) is stationary.
5. The variable camber vane system of claim 4, wherein the first airfoil portion (56)
and the second airfoil portion (58) form at least part of an inlet guide vane (42)
having a fixed leading edge and a variable trailing edge; wherein the first airfoil
portion (56) includes the leading edge; and wherein the second airfoil portion (58)
includes the trailing edge.
6. The variable camber vane system of claim 1, wherein the first airfoil portion (56)
and the second airfoil portion (58) form at least part of an outlet guide vane (44)
having a variable leading edge and a fixed trailing edge; wherein the first airfoil
portion (56) includes the leading edge; and wherein the second airfoil portion (58)
includes the trailing edge.
1. Schaufelsystem mit veränderbarer Wölbung für einen Gasturbinenmotor (10), umfassend:
einen ersten Flügelabschnitt (56) mit einem ersten Spitzenbereich (60), einem ersten
Wurzelbereich (62), einer sich zumindest teilweise zwischen dem ersten Spitzenbereich
(60) und dem ersten Wurzelbereich (62) erstreckenden Fläche (100) und einer Nut (98)
in der Fläche (100), die zumindest teilweise zwischen dem ersten Spitzenbereich (60)
und dem ersten Wurzelbereich (62) verläuft, wobei die Nut (98) eine Nutbreite (106)
hat,
einen zweiten Flügelabschnitt (58), der dazu angeordnet ist, sich bezüglich des ersten
Flügelabschnitts (56) um eine Schwenkachse (72) zu drehen, wobei der zweite Flügelabschnitt
(58) einen zweiten Spitzenbereich (66), einen zweiten Wurzelbereich (68) und eine
Krone (110) aufweist, die sich zumindest teilweise zwischen dem zweiten Spitzenbereich
(66) und dem zweiten Wurzelbereich (68) erstreckt, wobei die Krone (110) einen um
die Schwenkachse (72) zentrierten und gegenüber der Nut (98) angeordneten Kronenradius
(112) umfasst, und
ein Dichtungsband (96) mit einer Dichtungsbreite (104) größer als die Breite der Nut
(98) und einer konkaven Reibungsfläche (114), wobei die Reibungsfläche (114) vor einem
Einbau in den ersten Flügelabschnitt (56) dazu vorgeformt ist, einen zum Kronenradius
(112) komplementären und entgegengesetzten Radius (116) zu haben,
wobei das Dichtungsband (96) wenigstens teilweise mit einer Presspassung in der Nut
(98) angeordnet ist, und wobei das Dichtungsband (96) dazu angeordnet ist, gegen eine
Fluidströmung zwischen dem ersten Flügelabschnitt (56) und dem zweiten Flügelabschnitt
(58) abzudichten.
2. Schaufelsystem mit veränderbarer Wölbung nach Anspruch 1,
wobei die Reibungsfläche (114) einen mit dem Kronenradius (112) übereinstimmenden
Reibungsflächenradius (116) hat.
3. Schaufelsystem mit veränderbarer Wölbung nach Anspruch 1,
wobei die Krone (110) integral mit dem zweiten Flügelabschnitt (58) ausgebildet ist,
oder wobei die Fläche (100) integral mit dem ersten Flügelabschnitt (56) ausgebildet
ist,
oder wobei die Fläche (100) konkav und dazu funktionsfähig ist, die Krone (110) in
sich aufzunehmen.
4. Schaufelsystem mit veränderbarer Wölbung nach Anspruch 1,
wobei der erste Flügelabschnitt (56) stationär ist.
5. Schaufelsystem mit veränderbarer Wölbung nach Anspruch 4, wobei der erste Flügelabschnitt
(56) und der zweite Flügelabschnitt (58) zumindest einen Teil einer Einlassleitschaufel
(42) mit einer starren Vorderkante und einer verstellbaren Hinterkante bilden, wobei
der erste Flügelabschnitt (56) die Vorderkante enthält und wobei der zweite Flügelabschnitt
(58) die Hinterkante enthält.
6. Schaufelsystem mit veränderbarer Wölbung nach Anspruch 1, wobei der erste Flügelabschnitt
(56) und der zweite Flügelabschnitt (58) zumindest einen Teil einer Auslassleitschaufel
(44) mit einer verstellbaren Vorderkante und einer starren Hinterkante bilden, wobei
der erste Flügelabschnitt (56) die Vorderkante enthält und wobei der zweite Flügelabschnitt
(58) die Hinterkante enthält.
1. Système d'aube à cambrure variable pour un moteur à turbine à gaz (10), comprenant
:
une première partie de profil (56) ayant une première partie de pointe (60), une première
partie de base (62), une face (100) partant au moins partiellement entre la première
partie de pointe (60) et la première partie de base (62), et une rainure (98) dans
la face (100) partant au moins partiellement entre la première partie de pointe (60)
et la première partie de base (62), la rainure (98) ayant une largeur de rainure (106)
;
une seconde partie de profil (58) conçue pour tourner par rapport à la première partie
de profil (56) concernant un axe de pivot (72), la seconde partie de profil (58) comprenant
une seconde partie de pointe (66) ; une seconde partie de base (68) ; et une couronne
(110) partant au moins partiellement entre la seconde partie de pointe (66) et la
seconde partie de base (68), la couronne (110) comprenant un rayon de couronne (112)
centré autour de l'axe de pivot (72) et positionné en regard de la rainure (98) ;
et
une bande d'étanchéité (96) ayant une largeur d'étanchéité (104) supérieure à la largeur
de la rainure (98) et une face et une surface de friction concave (114), la surface
de friction (114) étant effectuée avant l'installation dans la première partie de
profil (56) pour avoir un rayon (116) complémentaire au rayon (112) de couronne et
en regard de celui-ci,
la bande d'étanchéité (96) étant au moins partiellement disposée dans la rainure (98)
avec un ajustement avec serrage ; et la bande d'étanchéité (96) étant conçue pour
rendre étanche à l'écoulement de fluide entre la première partie de profil (56) et
la seconde partie de profil (58).
2. Système d'aube à cambrure variable selon la revendication 1, la surface de friction
(114) ayant un rayon (116) de surface de friction identique au rayon (112) de couronne.
3. Système d'aube à cambrure variable selon la revendication 1, la couronne (114) faisant
partie intégrante de la seconde partie de profil (58) ;
ou la face (100) faisant partie intégrante de la première partie de profil (56) ;
ou la face (100) étant concave et opérant pour recevoir la couronne (110) en son sein.
4. Système d'aube à cambrure variable selon la revendication 1, la première partie de
profil (56) étant fixe.
5. Système d'aube à cambrure variable selon la revendication 4, la première partie de
profil (56) et la seconde partie de profil (58) formant au moins une partie d'une
aube guide d'admission (42) ayant un bord d'attaque fixe et un bord de fuite variable
; la première partie de profil (56) comprenant le bord d'attaque ; et la seconde partie
de profil (58) comprenant le bord de fuite.
6. Système d'aube à cambrure variable selon la revendication 1, la première partie de
profil (56) et la seconde partie de profil (58) formant au moins une partie d'une
aube guide de sortie (44) ayant un bord d'attaque variable et un bord d'attaque fixe
; la première partie de profil (56) comprenant le bord d'attaque ; et la seconde partie
de profil (58) comprenant le bord de fuite.