U.S. patent application number 12/751399 was filed with the patent office on 2011-10-06 for turbine shroud mounting apparatus with anti-rotation feature.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Daniel Verner Jones, Barry Allan Wilson.
Application Number | 20110243725 12/751399 |
Document ID | / |
Family ID | 43984153 |
Filed Date | 2011-10-06 |
United States Patent
Application |
20110243725 |
Kind Code |
A1 |
Jones; Daniel Verner ; et
al. |
October 6, 2011 |
TURBINE SHROUD MOUNTING APPARATUS WITH ANTI-ROTATION FEATURE
Abstract
A turbine shroud mounting apparatus includes: (a) a shroud
hanger having an arcuate body and including an arcuate first hook
which protrudes radially inward and extends axially forward from
the body, so as to define a first slot in cooperation with the
body; (b) an anti-rotation element disposed within the first slot,
the anti-rotation element being integrally formed with the shroud
hanger; and (c) an arcuate shroud segment including an arcuate
first mounting flange which protrudes radially outward and extends
axially aft, the first mounting flange having a receptacle formed
therein, where the first mounting flange is received in the first
slot and the anti-rotation member is received in the
receptacle.
Inventors: |
Jones; Daniel Verner;
(Fairfield, OH) ; Wilson; Barry Allan; (Broken
Arrow, OK) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
43984153 |
Appl. No.: |
12/751399 |
Filed: |
March 31, 2010 |
Current U.S.
Class: |
415/209.3 |
Current CPC
Class: |
F01D 11/08 20130101;
F05D 2260/30 20130101; F05D 2240/90 20130101; F01D 9/04 20130101;
F05D 2240/11 20130101; F01D 25/246 20130101; F05D 2230/642
20130101 |
Class at
Publication: |
415/209.3 |
International
Class: |
F01D 9/04 20060101
F01D009/04 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND
DEVELOPMENT
[0001] The U.S. Government may have certain rights in this
invention pursuant to contract number N00019-04-C-0093 awarded by
the Department of the Navy.
Claims
1. A turbine shroud mounting apparatus, comprising: (a) a shroud
hanger having an arcuate body and including an arcuate first hook
which protrudes radially inward and extends axially forward from
the body, so as to define a first slot in cooperation with the
body; (b) an anti-rotation element disposed within the first slot,
the anti-rotation element being integrally formed with the shroud
hanger; and (c) an arcuate shroud segment including an arcuate
first mounting flange which protrudes radially outward and extends
axially aft, the first mounting flange having a receptacle formed
therein, where the first mounting flange is received in the first
slot and the anti-rotation member is received in the
receptacle.
2. The apparatus of claim 1 wherein the anti-rotation element spans
the entire distance between the body and the first hook.
3. The apparatus of claim 1 wherein the first hook is disposed at
an aft end of the shroud segment.
4. The apparatus of claim 3 further including a second hook
disposed at a forward end of the shroud hanger, the second hook
protruding radially inward and extending axially forward from the
body, so as to define a second slot in cooperation with the
body.
5. The apparatus of claim 1 wherein the anti-rotation element is an
axially-elongated tab with a radiused forward end.
6. The apparatus of claim 1 wherein the receptacle is an
axially-elongated notch having parallel sidewalls and a radiused
forward end.
7. A turbine shroud apparatus for a gas turbine engine, comprising:
(a) a shroud hanger mounted to a casing of the engine, the shroud
hanger having an arcuate body and including an arcuate aft hook
which protrudes radially inward and extends axially forward from
the body, so as to define a first slot in cooperation with the
body; (b) an anti-rotation element disposed within the first slot,
the anti-rotation element being integrally formed with the shroud
hanger; and (c) an arcuate shroud segment including an arcuate
first mounting flange which protrudes radially outward and extends
axially aft, the first mounting flange having a receptacle formed
therein, where the first mounting flange is received in the first
slot and the anti-rotation member is received in the
receptacle.
8. The apparatus of claim 1 wherein the anti-rotation element spans
the entire distance between the body and the first hook.
9. The apparatus of claim 7 wherein the first hook is disposed at
an aft end of the shroud segment.
10. The apparatus of claim 9 further including a second hook
disposed at a forward end of the shroud hanger, the second hook
protruding radially inward and extending axially forward from the
body, so as to define a second slot in cooperation with the
body.
11. The apparatus of claim 7 wherein the anti-rotation element is
an axially-elongated tab with a radiused forward end.
12. The apparatus of claim 7 wherein the receptacle is an
axially-elongated notch having parallel sidewalls and a radiused
forward end.
13. A static element assembly for a gas turbine engine, comprising:
(a) a first static element having an arcuate body and including an
arcuate hook which protrudes radially inward and extends axially
forward from the body, so as to define a slot in cooperation with
the body; (b) an anti-rotation element disposed within the slot,
the anti-rotation element being integrally formed with the first
static element; and (c) an arcuate second static element including
an arcuate mounting flange which protrudes radially outward and
extends axially aft, the mounting flange having a receptacle formed
therein, where the mounting flange is received in the slot and the
anti-rotation member is received in the receptacle.
14. The assembly of claim 13 wherein the anti-rotation element
spans the entire distance between the body and the hook.
15. The assembly of claim 13 wherein the hook is disposed at an aft
end of the first static element.
16. The assembly of claim 13 wherein the anti-rotation element is
an axially-elongated tab with a radiused forward end.
17. The assembly of claim 13 wherein the receptacle is an
axially-elongated notch having parallel sidewalls and a radiused
forward end.
Description
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to gas turbine engines and
more particularly to methods for mounting components in the turbine
sections of such engines.
[0003] A gas turbine engine includes a turbomachinery core having a
high pressure compressor, combustor, and a high pressure turbine in
serial flow relationship. The core is operable in a known manner to
generate a primary gas flow. The high pressure turbine includes one
or more rotors which extract energy from the primary gas flow. Each
rotor comprises an annular array of blades or buckets carried by a
rotating disk. The flowpath through the rotor is defined in part by
annular shrouds encircling the blades or buckets.
[0004] Conventional turbine shrouds are supported by segmented
hangers which are in turn mounted to the engine's casing. Shrouds
and shroud hangers require an anti-rotation feature to hold the
shroud and hanger circumferentially in place. The majority of prior
art shrouds utilize a pin press fitted into a hole in a hook of the
shroud hanger. The pin interfaces with a notch on the shroud. The
pin installation process requires tight tolerances and extra
assembly processes that could include an additional braze
operation. The pin has also been known to cause maintenance
problems.
BRIEF SUMMARY OF THE INVENTION
[0005] These and other shortcomings of the prior art are addressed
by the present invention, which provides a turbine shroud hanger
which incorporates an integral anti-rotation element.
[0006] According to one aspect of the invention, a turbine shroud
mounting apparatus includes: (a) a shroud hanger having an arcuate
body and including an arcuate first hook which protrudes radially
inward and extends axially forward from the body, so as to define a
first slot in cooperation with the body; (b) an anti-rotation
element disposed within the first slot, the anti-rotation element
being integrally formed with the shroud hanger; and (c) an arcuate
shroud segment including an arcuate first mounting flange which
protrudes radially outward and extends axially aft, the first
mounting flange having a receptacle formed therein, where the first
mounting flange is received in the first slot and the anti-rotation
member is received in the receptacle.
[0007] According to another aspect of the invention, a turbine
shroud apparatus for a gas turbine engine includes: (a) a shroud
hanger mounted to a casing of the engine, the shroud hanger having
an arcuate body and including an arcuate aft hook which protrudes
radially inward and extends axially forward from the body, so as to
define a first slot in cooperation with the body; (b) an
anti-rotation element disposed within the first slot, the
anti-rotation element being integrally formed with the shroud
hanger; and (c) an arcuate shroud segment including an arcuate
first mounting flange which protrudes radially outward and extends
axially aft, the first mounting flange having a receptacle formed
therein, where the first mounting flange is received in the first
slot and the anti-rotation member is received in the
receptacle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention may be best understood by reference to the
following description taken in conjunction with the accompanying
drawing figures in which:
[0009] FIG. 1 is a schematic cross-sectional view of a high
pressure turbine of a gas turbine engine, incorporating a shroud
apparatus constructed in accordance with an aspect of the present
invention;
[0010] FIG. 2 is a perspective view of a turbine shroud hanger
shown in FIG. 1;
[0011] FIG. 3 is a perspective view of a turbine shroud shown in
FIG. 1; and
[0012] FIG. 4 is a cross-sectional view taken along lines 4-4 of
FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to the drawings wherein identical reference
numerals denote the same elements throughout the various views,
FIG. 1 depicts a portion of a high pressure turbine, which is part
of a gas turbine engine of a known type. The function of the high
pressure turbine is to extract energy from high-temperature,
pressurized combustion gases from an upstream combustor 10 and to
convert the energy to mechanical work. The high pressure turbine
drives an upstream compressor (not shown) through a shaft so as to
supply pressurized air to the combustor 10.
[0014] In the illustrated example, the engine is a turbofan engine
and a low pressure turbine would be located downstream of the high
pressure turbine 10 and coupled to a shaft driving a fan and
optionally a low-pressure compressor or "booster". However, the
principles described herein are equally applicable to turboprop,
turbojet, and turboshaft engines, as well as turbine engines used
for other vehicles or in stationary applications.
[0015] The high pressure turbine includes a nozzle 12 which
comprises an array of circumferentially spaced airfoil-shaped
hollow vanes 14 that are supported between an arcuate, segmented
outer band 16 and an arcuate, segmented inner band 18. The vanes
14, outer band 16 and inner band 18 are arranged into a plurality
of circumferentially adjoining nozzle segments that collectively
form a complete 360.degree. assembly. The outer and inner bands 16
and 18 define the outer and inner radial flowpath boundaries,
respectively, for the hot gas stream flowing through the nozzle 12.
The vanes 14 are configured so as to optimally direct the
combustion gases to a rotor 20.
[0016] The rotor 20 includes a array of airfoil-shaped turbine
blades 22 extending outwardly from a disk 24 that rotates about the
centerline axis of the engine. A shroud comprising a plurality of
arcuate shroud segments 26 is arranged so as to closely surround
the turbine blades 22 and thereby define the outer radial flowpath
boundary for the hot gas stream flowing through the rotor 20.
[0017] The shroud segments 26 are carried by arcuate shroud hangers
28, which are in turn mounted to an annular casing 30. Each shroud
hanger 28 includes an arcuate body 32 with opposed inner and outer
faces, and forward and aft ends. It is noted that the terms
"forward" and "aft" and other similar directional indications are
relative and are used herein solely for reference. An arcuate seal
lip 34 extends from the forward end and contacts a leaf seal 36 of
a known type carried by the outer band 16 of the upstream turbine
nozzle 12. An arcuate forward flange 38 with an "L"-shaped
cross-section extends radially outward from the forward end of the
shroud hanger 28 and engages a slot in the casing 30. An arcuate
aft flange 40 with an "L"-shaped cross-section extends radially
outward from the aft end of the shroud hanger 28 and engages
another slot in the casing 30. An arcuate forward hook 42 disposed
at the forward end of the shroud hanger 28 protrudes radially
inward and extends axially forward. It defines a forward slot 44 in
cooperation with the body 32. An arcuate aft hook 46 disposed at
the aft end of the shroud hanger 28 protrudes radially inward and
extends axially forward. It defines an aft slot 48 in cooperation
with the body 32.
[0018] As best seen in FIG. 2, the shroud hanger 28 incorporates a
fixed anti-rotation element 50 disposed in the aft slot 48,
spanning the distance between the body 32 and the aft hook 46. So
long as it is securely fixed in place, the anti-rotation element 50
may be an integral part of the shroud segment 28 or it may be
fabricated separately and then securely attached to the shroud
hanger 28, for example by welding or brazing. If desired, it could
be incorporated in the forward slot 44 instead. In the illustrated
example the anti-rotation element 50 is an axially-elongated tab
with a radiused forward end. However, any shape which is effective
to resist tangential motion of the shroud segment 26 when engaged
with a mating feature of the shroud segment 26 may be used. As used
herein the term "tangential" refers to motion in or out of the page
in FIG. 1.
[0019] The shroud hangers 28 may be constructed from a material
such as a known cobalt, nickel, or steel-based superalloy which has
acceptable strength at the elevated temperatures of operation in a
gas turbine engine. Various superalloys are commercially available
under trade names such as INCONEL, HASTELLOY, and RENE. The shroud
hangers 28 may be formed from castings which are then machined to
final dimensions. The aft hooks 46 of the shroud hangers 28 may be
formed by machining with an EDM electrode (not shown). EDM is a
known process in which an electrode is fed into the workpiece while
an electrical potential is applied between the electrode and
workpiece. Spark discharge across the gap between workpiece and
electrode causes erosion of the workpiece. The anti-rotation
element 50 described above may be created by removing a notch or
other negative feature of equal shape and size from an EDM
electrode used to machine prior art shroud hangers. Once the
material has been removed from the electrode, the EDM process is
identical to the original hook machining process.
[0020] Referring back to FIG. 1, each shroud segment 26 includes an
arcuate forward mounting flange 52 disposed at the forward end of
the shroud segment 26 which protrudes radially outward and extends
axially aft. An arcuate aft mounting flange 54 disposed at the aft
end of the shroud segment 26 protrudes radially outward and extends
axially aft. As shown in FIG. 3, the shroud segment 26 incorporates
a receptacle 56 disposed in the aft mounting flange 54 which has a
shape complementary to the anti-rotation element 50. In the
illustrated example the receptacle 56 is an axially-elongated notch
having parallel sidewalls and a radiused forward end. However, any
shape which is effective to resist tangential motion of the shroud
segment 26 when engaged with a mating feature of the shroud hanger
28 may be used. The receptacle 56 may be formed in the aft mounting
flange 42 using an EDM process as described above.
[0021] The shroud segments 26 are assembled to the shroud hangers
28 by engaging the forward mounting flanges 40 with the forward
hooks 44 and the aft mounting flanges 42 with the aft hooks 46. The
shroud segments 26 are then slid aft so that the receptacles 56
engage the anti-rotation elements 52. FIG. 4 shows the two
components in the assembled condition. No further assembly or
manufacturing operations are required to provide positive
anti-rotation between the shroud segment 26 and the shroud hanger
28.
[0022] As compared to a conventional design, the shroud mounting
apparatus described herein eliminates extra machining steps,
provides for simplified assembly, and reduces part count. The
principles described herein may easily be implemented for any
turbine shroud that uses an EDM procedure to machine its support
hooks.
[0023] The foregoing has described a shroud mounting apparatus.
While specific embodiments of the present invention have been
described, it will be apparent to those skilled in the art that
various modifications thereto can be made without departing from
the spirit and scope of the invention. In particular, the
principles of the present invention may be extended to other types
of turbine hardware, in particular any assembly of two or more
static elements which must be restrained against relative rotation.
Accordingly, the foregoing description of the preferred embodiment
of the invention and the best mode for practicing the invention are
provided for the purpose of illustration only and not for the
purpose of limitation.
* * * * *