U.S. patent application number 11/006925 was filed with the patent office on 2006-06-08 for gas turbine engine assembly and method of assembling same.
Invention is credited to Stephen Eugene Melton, Michael Peter Murphy, Thomas George Wakeman.
Application Number | 20060120854 11/006925 |
Document ID | / |
Family ID | 36103767 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060120854 |
Kind Code |
A1 |
Wakeman; Thomas George ; et
al. |
June 8, 2006 |
Gas turbine engine assembly and method of assembling same
Abstract
A method for assembling a gas turbine engine assembly, including
a gas turbine engine, a power turbine coupled to the gas turbine
engine, and a thrust bearing coupled to the power turbine. The
method includes coupling a first annular portion having a first
radius to the power turbine, coupling a second annular portion
having a second radius to the thrust bearing, wherein the first
radius is different than the second radius, and coupling a
plurality of structural members between the first and second
portions such that the thrust assembly has a substantially
frusto-conical shape.
Inventors: |
Wakeman; Thomas George;
(Frankfort, OH) ; Melton; Stephen Eugene; (West
Chester, OH) ; Murphy; Michael Peter; (Loveland,
OH) |
Correspondence
Address: |
JOHN S. BEULICK;C/O ARMSTRONG TEASDALE LLP
ONE METROPOLITAN SQUARE
SUITE 2600
ST. LOUIS
MO
63102-2740
US
|
Family ID: |
36103767 |
Appl. No.: |
11/006925 |
Filed: |
December 8, 2004 |
Current U.S.
Class: |
415/104 |
Current CPC
Class: |
F01D 25/28 20130101;
F01D 25/168 20130101; F01D 3/04 20130101; F01D 25/164 20130101;
F05D 2240/52 20130101; F02C 7/06 20130101 |
Class at
Publication: |
415/104 |
International
Class: |
F01D 3/04 20060101
F01D003/04 |
Claims
1. A method for assembling a gas turbine engine assembly, including
a gas turbine engine, a power turbine coupled to the gas turbine
engine, and a thrust bearing coupled to the power turbine, said
method comprising: coupling a first annular portion having a first
radius to the power turbine; coupling a second annular portion
having a second radius to the thrust bearing, wherein the first
radius is different than the second radius; and coupling a
plurality of structural members between the first and second
portions such that the thrust assembly has a substantially
frusto-conical shape.
2. A method in accordance with claim 1 wherein coupling a second
annular portion having a second radius to the thrust bearing
further comprises coupling a second annular portion having a second
radius that is less than the first to the thrust bearing.
3. A method in accordance with claim 1 further comprising forming
the first portion, the second portion, and the structural members
as a unitary thrust assembly.
4. A method in accordance with claim 1 wherein said method further
comprises: coupling a first attachment foot to a connecting member
first end; and coupling a second attachment foot a connecting
member second end to form a unitary structurally member.
5. A method in accordance with claim 4 further comprising: coupling
the first attachment foot to the first portion; and coupling the
second attachment foot to the second portion.
6. A method in accordance with claim 5 further comprising:
providing a connecting member having a width and a thickness; and
coupling a first attachment foot to the connecting member, wherein
the attachment foot includes a first end and a second end, the
first end having a width and a thickness that is substantially
similar to the connecting member width and thickness, the second
end having a width that is substantially greater than the
connecting member width and a thickness that is substantially less
than the connecting member thickness.
7. A thrust assembly for a gas turbine engine assembly that
includes a gas turbine engine, a power turbine coupled to the gas
turbine engine, and a thrust bearing coupled to the power turbine,
said thrust assembly comprising: a first annular portion having a
first radius coupled to said power turbine; a second annular
portion having a second radius coupled to said thrust bearing, said
first radius different than said second radius; and a plurality of
structural members extending between said first and second portions
such that said thrust assembly has a substantially frusto-conical
shape.
8. A thrust assembly in accordance with claim 7 wherein said first
radius is greater than said second radius.
9. A thrust assembly in accordance with claim 7 wherein said first
portion, said second portion, and said structural members are
formed unitarily.
10. A thrust assembly in accordance with claim 7 wherein said
connecting members comprise: a first attachment foot; a second
attachment foot; and a connecting member that extends between and
is coupled to said first and second attachment feet.
11. A thrust assembly in accordance with claim 10 wherein said
first attachment foot is coupled to said first portion and said
second attachment foot is coupled to said second portion.
12. A thrust assembly in accordance with claim 10 further
comprising: a connecting member having a width and a thickness; and
a first attachment foot comprising: a first end and a second end,
said first end having a width and a thickness that is substantially
similar to said connecting member width and thickness, said second
end having a width that is substantially greater than said
connecting member width and a thickness that is substantially less
than said connecting member thickness.
13. A thrust assembly in accordance with claim 7 wherein said
thrust assembly comprises seven connecting members.
14. A gas turbine engine assembly comprising: a gas turbine engine
comprising: a first compressor; a second compressor downstream from
said first compressor; a turbine coupled in flow communication with
said second compressor; a power turbine coupled to said gas turbine
engine; a thrust bearing coupled to said power turbine; and a
thrust assembly coupled between said power turbine and said thrust
bearing, said thrust bearing assembly comprising: a first annular
portion having a first radius coupled to said power turbine; a
second annular portion having a second radius coupled to said
thrust bearing, said first radius different than said second
radius; and a plurality of structural members extending between
said first and second portions such that said thrust assembly has a
substantially frusto-conical shape.
15. A gas turbine engine assembly in accordance with claim 14
wherein said first radius is greater than said second radius.
16. A gas turbine engine assembly in accordance with claim 14
wherein said first portion, said second portion, and said
structural members are formed unitarily.
17. A gas turbine engine assembly in accordance with claim 14
wherein said connecting members comprise: a first attachment foot;
a second attachment foot; and a connecting member that extends
between and is coupled to said first and second attachment
feet.
18. A gas turbine engine assembly in accordance with claim 17
wherein said first attachment foot is coupled to said first portion
and said second attachment foot is coupled to said second
portion.
19. A thrust assembly in accordance with claim 14 further
comprising: a connecting member having a width and a thickness; and
a first attachment foot comprising: a first end and a second end,
said first end having a width and a thickness that is substantially
similar to said connecting member width and thickness, said second
end having a width that is substantially greater than said
connecting member width and a thickness that is substantially less
than said connecting member thickness.
20. A thrust assembly in accordance with claim 14 wherein said
thrust assembly comprises seven connecting members.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to gas turbine engines, and
more specifically to a gas turbine engine and method of assembling
a gas turbine engine.
[0002] At least some known gas turbine engines include, in serial
flow arrangement, a high-pressure compressor for compressing air
flowing through the engine, a combustor in which fuel is mixed with
the compressed air and ignited to form a high temperature gas
stream, and a high pressure turbine. The high-pressure compressor,
combustor and high-pressure turbine are sometimes collectively
referred to as the core engine. Such gas turbine engines may also
include a low-pressure turbine or power turbine for transmitting
power generated by the core engine to a driven component, such as a
generator, for example.
[0003] Gas turbine engines are used in many applications, including
aircraft, power generation, and marine applications. At least some
known gas turbine engines include two thrust mounts that are
coupled between an exterior surface of the gas turbine engine and a
support structure. During engine operation, at least some known
thrust mounts may cause at least some structural distortion or "out
of round" condition of the gas turbine engine casing which may
reduce blade tip clearances within the gas turbine engine.
Moreover, when a power turbine is coupled to the core gas turbine
engine, the combination of loads and geometries may also cause some
structural distortion which may also reduce blade tip clearances
within the gas turbine engine.
[0004] For example, during operation, the thrust load generated by
at least some known power turbine rotors is approximately 250,000
lb in a direction that is opposite to the direction of thrust
generated by the gas turbine engine. Accordingly, during operation,
thrust generated by the power turbine is transferred to the engine
thrust mounts, thus increasing the possibility that the gas turbine
engine may experience structural distortion, or an "out of round"
condition. Alternatively, thrust generated by the power turbine may
be transferred to the power turbine thrust bearing support which
may also increase the possibility that the gas turbine engine may
experience structural distortion. To facilitate reducing such
structural distortion, at least some known turbines attempt to
balance loading between the engine thrust mounts and the power
turbine thrust bearing support. However, even if the power turbine
thrust load is balanced between the engine thrust mounts and the
power turbine thrust bearing support, the combined power turbine
rotor load and the gas turbine engine residual load may cause the
core gas turbine engine casing to distort which may reduce blade
tip clearances within the gas turbine engine.
BRIEF DESCRIPTION OF THE INVENTION
[0005] In one aspect, a method for assembling a gas turbine engine
assembly, including a gas turbine engine, a power turbine coupled
to the gas turbine engine, and a thrust bearing coupled to the
power turbine. The method includes coupling a first annular portion
having a first radius to the power turbine, coupling a second
annular portion having a second radius to the thrust bearing,
wherein the first radius is different than the second radius, and
coupling a plurality of structural members between the first and
second portions such that the thrust assembly has a substantially
frusto-conical shape.
[0006] In another aspect, a thrust assembly for a gas turbine
engine assembly that includes a gas turbine engine, a power turbine
coupled to the gas turbine engine, and a thrust bearing coupled to
the power turbine. The thrust assembly includes a first annular
portion having a first radius coupled to the power turbine, a
second annular portion having a second radius coupled to the thrust
bearing, the first radius different than the second radius, and a
plurality of structural members extending between the first and
second portions such that the thrust assembly has a substantially
frusto-conical shape.
[0007] In a further aspect, a gas turbine engine assembly is
provided. The gas turbine engine assembly includes a gas turbine
engine including a first compressor, a second compressor downstream
from the first compressor, a turbine coupled in flow communication
with the second compressor, a power turbine coupled to the gas
turbine engine, a thrust bearing coupled to the power turbine, and
a thrust assembly coupled between the power turbine and the thrust
bearing. The thrust bearing assembly includes a first annular
portion having a first radius coupled to the power turbine, a
second annular portion having a second radius coupled to the thrust
bearing, the first radius different than the second radius, and a
plurality of structural members extending between the first and
second portions such that the thrust assembly has a substantially
frusto-conical shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of an exemplary gas turbine
engine;
[0009] FIG. 2 is a side view of a portion of the gas turbine engine
shown in FIG. 1 including a support cage;
[0010] FIG. 3 is a perspective view of the support cage shown in
FIG. 2;
[0011] FIG. 4 is an end view of the support cage shown in FIG.
2;
[0012] FIG. 5 is a top view of a portion of the support cage shown
in FIG. 2;
[0013] FIG. 6 is a side view of a portion of the support cage shown
in FIG. 5; and
[0014] FIG. 7 is a side view of a portion of a connecting member
shown in FIGS. 5 and 6.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 is a block diagram of a gas turbine engine assembly
10. Gas turbine engine 10 includes, in serial flow relationship, a
low pressure compressor or booster 14, a high pressure compressor
16, a combustor 18, a high pressure turbine 20, an intermediate
pressure turbine 22, and a low pressure or power turbine 24. Low
pressure compressor or booster 14 has an inlet 26 and an outlet 28,
and high pressure compressor 16 includes an inlet 30 and an outlet
32. Combustor 18 has an inlet 34 that is substantially coincident
with high pressure compressor outlet 32, and an outlet 36. In the
exemplary embodiment, gas turbine engine assembly 10 is an LMS100
manufactured by General Electric Company.
[0016] High pressure turbine 20 is coupled to high pressure
compressor 16 with a first rotor shaft 40, and intermediate
pressure turbine 22 is coupled to low pressure compressor 14 with a
second rotor shaft 42. Rotor shafts 40 and 42 are each
substantially coaxially aligned with respect to a longitudinal
centerline axis 43 of engine 10. Engine 10 may be used to drive a
load 44, such as a generator, which may be coupled to a power
turbine shaft 46. Alternatively, the load may be coupled to a
forward extension (not shown) of rotor shaft 42.
[0017] In the exemplary embodiment, gas turbine engine assembly 10
also includes an intercooler heat exchanger 50 that is positioned
between low pressure compressor or booster 14 and high pressure
compressor 16 to facilitate reducing the temperature of the air
entering high pressure compressor 16. Using an intercooler
facilitates increasing the efficiency of the engine while reducing
the quantity of work performed by the high pressure compressor. At
least one known intercooler heat exchanger uses ambient air or
water as a cooling medium 52 to cool the air flow exiting the
booster compressor. In an alternative embodiment, gas turbine
engine 10 does not include intercooler heat exchanger 50.
[0018] In operation, ambient air, drawn into low pressure
compressor inlet 26, is compressed and channeled downstream to high
pressure compressor 16. High pressure compressor 16 further
compresses the air and delivers high pressure air to combustor 18
where it is mixed with fuel, and the mixture is ignited to generate
high temperature combustion gases. The combustion gases are
channeled from combustor 18 to drive turbines 20, 22, and 24. More
specifically, power turbine 24 is aerodynamically coupled to
intermediate pressure turbine 22 such that thrust generated by gas
turbine engine 10 is used to drive power turbine 24. Moreover,
since power turbine 24 is coupled to a load 44, gas turbine engine
assembly 10 also drives load 44. In the exemplary embodiment, load
44 is coupled to power turbine 24 utilizing a thrust bearing 54,
and coupled to a support structure 56 utilizing a pedestal 58, for
example. More specifically, both power turbine 24 and support
structure 56 are coupled along centerline axis 43 such that gas
turbine engine assembly 10 is substantially axially aligned with
thrust bearing 54 and therefore load 44. In the exemplary
embodiment, the core gas turbine engine casing is mechanically
coupled to the power turbine casing using a plurality of fasteners,
such that the power turbine rotor is aerodynamically coupled to the
core gas turbine engine.
[0019] FIG. 2 is a side view of a portion of the gas turbine engine
shown in FIG. 1 including a support cage 100. FIG. 3 is a
perspective view of the support cage shown in FIG. 2. FIG. 4 is an
end view of the support cage shown in FIG. 2. In the exemplary
embodiment, support cage 100 is also referred to as a gorilla
cage.
[0020] In the exemplary embodiment, support cage 100 is
substantially frusto-conical shaped. Alternatively, the term
frusto-conical as used herein is defined as a truncated cone or
pyramid. Accordingly, support cage 100 includes a first portion 110
that is substantially circular and has a first radius 112, and a
second portion 114 that is substantially circular and has a second
radius 116. In the exemplary embodiment, first radius 112 is larger
than second radius 116.
[0021] Support cage 100 also includes a plurality of structural
members 120 that extend between, and are coupled to, first and
second portions 110 and 114, respectively. In the exemplary
embodiment, first and second portions 110 and 114 are substantially
circular. Each structural members 120 has a length 122 that is
sized to enable support cage 100 to extend between a turbine rear
frame 124 and a thrust bearing housing 126. Moreover, in the
exemplary embodiment, each member 120 has a substantially similar
length such that first portion 110 is substantially parallel to
second portion 114. In the exemplary embodiment, support cage 100
includes seven structural members 120 that are approximately
equally spaced around a circumference of first and second portions
110 and 114, respectively. Alternatively, support cage 100 includes
more or less than seven structural members.
[0022] In the exemplary embodiment, support cage 100 includes a
first support cage structure 115 and a second support cage
structure 117. More specifically, support cage 100 is fabricated in
two sections 115 and 117, respectively, wherein each structure
includes a plurality of members 120, such that support cage 100 can
be coupled to gas turbine assembly 10. In one embodiment, first
support cage structure 115 is coupled to second support cage
structure 117 using a welding procedure, for example. In an
alternative embodiment, first support cage structure 115 is coupled
to second support cage structure 117 using a plurality of
mechanical fasteners. In the exemplary embodiment, first support
cage structure 115 extends at least 180 degrees around the power
turbine centerline axis, and second support cage structure 117
extends less than 180 degrees around the power turbine centerline
axis. In an alternative embodiment, first and second support cage
structures 115 and 117 each extend 180 degrees around the power
turbine centerline axis.
[0023] FIG. 5 is a top view of a portion of the support cage shown
in FIG. 2. Specifically, FIG. 5 is a top view of a structural
member 120. FIG. 6 is a side view of the structural member shown in
FIG. 5. FIG. 7 is a side view of a portion of a connecting member
120 shown in FIGS. 5 and 6. Each structural member 120 includes a
first attachment foot 150, a second attachment foot 152, and a
connecting member 154 that extends between, and is coupled to,
first and second attachment feet 150 and 152, respectively.
Connecting member 154 has a width 160, a thickness 162, and a
length 164. First and second attachment feet 150 and 152 each
include a first portion 170 and a second portion 172 that is
coupled to first portion 170. In one embodiment, first and second
portions 170 and 172 are unitarily formed together to form unitary
first and second attachment feet 150 and 152. Attachment feet 150
and 152 are each coupled to connecting member 154 through a brazing
and/or welding procedure, for example. In another embodiment, first
and second attachment feet 150 and 152, and connecting member 154
are fabricated together unitarily to form each member 120. In an
alternative embodiment, each member 120 is fabricated from a
plurality of pieces.
[0024] Attachment foot first portion 170 includes a first end 180
that has a width 182 that is approximately equal to connecting
member width 160, and a thickness 184 that is approximately equal
to connecting member thickness 162. Attachment foot first portion
170 includes a second end 190 that has a width 192 that is wider
than first end width 182, and a thickness 194 that is narrower than
first end thickness 184. Accordingly, and in the exemplary
embodiment, first portion 170 has a width and thickness 182 and
184, that are approximately equal to width and thickness 160 and
162 of connecting member.120. Moreover, first portion 170 has a
width that gradually increases from first end 180 to second end
190, and a thickness that gradually decreases from first end 180 to
second end 190.
[0025] Attachment foot second portion 172 includes a first end 200
that has a width 202 that is approximately equal to first portion
width 192, and a thickness 204 that is approximately equal to first
portion thickness 194. Attachment foot second portion 172 includes
a second end 210 that has a width 212 that is approximately equal
to width 202 and a thickness 214 that is approximately equal to
thickness 204. Accordingly, and in the exemplary embodiment, second
portion 172 has a width and thickness 200 and 204, that are
approximately equal between first and second ends 200 and 210,
respectively.
[0026] In the exemplary embodiment, support cage 100 is fabricated
from a material, such as, but not limited to, AISI 4140 steel which
has a relatively high modulus, good ductility (LCF capability),
moderate strength, and relatively low cost. In the exemplary
embodiment, members 120 flex in an axial direction and therefore
absorb thrust loading between gas turbine engine 10 and power
turbine 24. In another embodiment, members 120 are fabricated from
a metallic material that is different than first and second
portions 110 and 114, respectively.
[0027] During assembly, support cage 100 is coupled between a power
turbine thrust bearing thrust housing 126 and an interior surface
252 of power turbine 24. More specifically, first portion 110 is
coupled to a power turbine frame aft internal flange 254, and
second portion 114 is coupled to an external surface of thrust
bearing housing 126. In the exemplary embodiment, support cage 100
is coupled to gas turbine engine 10 using a plurality of mechanical
fasteners such as nuts and bolts, for example. In another
embodiment, support cage 100 is coupled to gas turbine engine 10
using a welding and brazing procedure for example.
[0028] In use, support cage 100 facilitates reducing the thrust
load generated by the power turbine. More specifically, support
cage 100 facilitates balancing the thrust load generated by the
power turbine by transferring a portion of the thrust load back to
the gas turbine engine. For example, in the exemplary embodiment,
gas turbine engine assembly 10 generates approximately 260,000 lbs.
of thrust in an axially forward direction, whereas power turbine 24
generates approximately 240,000 lbs in an axially aft direction.
Accordingly, coupling power turbine 24 to thrust bearing 54 using
support cage 100 facilitates balancing the total gas turbine
assembly thrust flow between gas turbine engine 10 and power
turbine 24 at the engine centerline thereby reducing thrust load
distortions seen by known gas turbine engines utilizing side
mounted thrust supports. Moreover, support cage 100 facilitates
reducing the gas turbine engine structural distortion thereby
improving blade tip clearances within the gas turbine engine.
[0029] The above-described support cage provides a cost-effective
and highly reliable thrust assembly that includes a substantially
frusto-conical shape for transferring the power turbine thrust load
from the power turbine thrust bearing to the gas turbine engine
thrust mounts. Accordingly, a thrust path is created between the
power turbine thrust bearing and the gas turbine engine in a
cost-effective manner.
[0030] An exemplary embodiment of thrust assembly is described
above in detail. The thrust assembly is not limited to the specific
embodiments described herein, but rather, components of the
assembly may be utilized independently and separately from other
components described herein. Moreover, the thrust assembly
described herein can also be used in combination with a variety of
gas turbine engines.
[0031] While the invention has been described in terms of various
specific embodiments, those skilled in the art will recognize that
the invention can be practiced with modification within the spirit
and scope of the claims.
* * * * *