U.S. patent application number 13/274950 was filed with the patent office on 2013-04-18 for system for sealing a shaft.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is Sergio Daniel Marques Amaral, Gary Michael Itzel, Kenneth Dale Moore, Xiuzhang James Zhang. Invention is credited to Sergio Daniel Marques Amaral, Gary Michael Itzel, Kenneth Dale Moore, Xiuzhang James Zhang.
Application Number | 20130094969 13/274950 |
Document ID | / |
Family ID | 47115376 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130094969 |
Kind Code |
A1 |
Amaral; Sergio Daniel Marques ;
et al. |
April 18, 2013 |
SYSTEM FOR SEALING A SHAFT
Abstract
An embodiment of the present invention takes the form of a seal
that may substantially reduce cross-shank leakage between
components mounted on a shaft. Embodiments of the seal may be
connected to a wide variety of rotatable components including, but
not limited to, compressor blades, turbine buckets, or the
like.
Inventors: |
Amaral; Sergio Daniel Marques;
(Cambridge, MA) ; Itzel; Gary Michael;
(Simpsonville, SC) ; Zhang; Xiuzhang James;
(Simpsonville, SC) ; Moore; Kenneth Dale;
(Greenville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Amaral; Sergio Daniel Marques
Itzel; Gary Michael
Zhang; Xiuzhang James
Moore; Kenneth Dale |
Cambridge
Simpsonville
Simpsonville
Greenville |
MA
SC
SC
SC |
US
US
US
US |
|
|
Assignee: |
General Electric Company
|
Family ID: |
47115376 |
Appl. No.: |
13/274950 |
Filed: |
October 17, 2011 |
Current U.S.
Class: |
416/219R |
Current CPC
Class: |
F01D 11/006
20130101 |
Class at
Publication: |
416/219.R |
International
Class: |
F01D 5/30 20060101
F01D005/30 |
Claims
1. A system comprising: a rotatable component comprising: an
airfoil portion comprising a first end, an opposite second end, and
suction and pressure surfaces located between the first end and the
opposite second end; a shank portion comprising a mount and a slot,
wherein the slot is positioned near a wall and is adjacent a
downstream edge of the airfoil portion; a platform portion that
connects the airfoil portion to the shank portion; a seal
comprising: an arm portion; and a hook portion; wherein the arm and
hook portions are shaped to mate with the slot such that the slot
restrains the movement of the seal; wherein the seal is sized to
substantially prevent a cooling flow from leaking through a shank
pocket.
2. The system of claim 1, wherein the rotatable component is
located in a turbine section of an air-ingesting turbomachine.
3. The system of claim 1, wherein the rotatable component is
located in a compressor section of an air-ingesting
turbomachine.
4. The system of claim 1, wherein the seal is maintained in the
slot by a pressure difference between the shank pocket and a purge
flow associated with an aft end of the rotatable component.
5. The system of claim 1, wherein the width of the seal comprises a
range of from about 0.2 inches to about 1.0 inch.
6. The system of claim 1, wherein a length of the seal comprises a
range of from about 2.0 inches to about 10.0 inches.
7. The system of claim 1, wherein a thickness of the seal comprises
a range of from about 0.1 inches to about 0.5 inches.
8. The system of claim 1, wherein a shape of the hook portion
includes: an arc portion, a polygon, or combinations thereof.
9. The system of claim 8, wherein a diameter of the arc portion
comprises a range of from about 0.2 inches to about 1.0 inch.
10. A system comprising: a gas turbine comprising: a compressor
section and a turbine section; a turbine bucket installed in the
turbine section, wherein the turbine bucket comprises: an airfoil
comprising a tip, a base, and suction and pressure surfaces that
connected the tip and the base; a shank comprising a mount and a
slot, wherein the slot is positioned near a surface that is
adjacent an edge of the airfoil, and an end of the slot is adjacent
to a top portion of the mount; a platform portion that connects the
airfoil to the shank; a seal comprising: an arm; and a hook;
wherein the arm and hook are sized to allow insertion into the slot
such that the slot secures the movement of the seal; wherein the
seal has a width that substantially prevents a cooling flow from
leaking through a shank pocket, which is formed between the shank
portion of the rotatable component and an another shank portion of
an adjacent rotatable component.
11. The system of claim 10, wherein the seal is maintained in the
slot by a pressure difference between the shank pocket and a purge
flow associated with the turbine bucket.
12. The system of claim 10, wherein the width of the seal comprises
a range of from about 0.2 inches to about 1.0 inch.
13. The system of claim 10, wherein a length of the seal extends
from the platform to the mount.
14. The system of claim 10, wherein the length of the seal
comprises a range of from about 2.0 inches to about 10.0
inches.
15. The system of claim 10, wherein a thickness of the seal
comprises a range of from about 0.1 inches to about 0.5 inches.
16. The system of claim 10, wherein a shape of the hook portion
includes: an arc portion, a polygon, or combinations thereof.
17. The system of claim 16, wherein a diameter of the arc portion
comprises a range of from about 0.2 inches to about 1.0 inch.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to seals for air-ingesting
turbomachines; and more particularly to a seal for the shank region
of a rotating component of the turbomachine.
[0002] Conventional turbomachines includes compressor and turbine
sections that each has a plurality of rotating components
(compressor blades, turbine components, etc) attached about a
circumference of a turbine rotor. Each rotating component is
located at a distance away from an adjacent rotating component to
allow movement and expansion during operation. Each rotatable
component includes: a shank that attaches to the rotor, a platform,
and an airfoil that extends radially outwardly from the
platform.
[0003] The area between the adjacent rotating components is
considered the shank pocket. Generally, the cavities between the
rotating components and adjacent stationary components forward and
aft of the shank pocket are at different operating pressures. Fluid
naturally flows from the higher pressure cavity to the lower
pressure cavity through gaps; which allow for movement and
expansion, between adjacent rotating components. In addition, fluid
flowing over the platform can leak into the shank pocket. These
sources of "cross-shank" leakage are detrimental to the performance
of the turbomachine. The severity of the leakage depends, in part,
on the size of the shank.
[0004] For the foregoing reasons, there is a need for a system that
reduces cross-shank leakage. The system should provide a simple
seal design that may be applied to a turbine bucket and/or a
compressor blade.
BRIEF DESCRIPTION OF THE INVENTION
[0005] Certain embodiments commensurate in scope with the
originally claimed invention are summarized below. These
embodiments are not intended to limit the scope of the claimed
invention, but rather these embodiments are intended only to
provide a brief summary of possible forms of the invention. Indeed,
the invention may encompass a variety of forms that may be similar
to or different from the embodiments set forth below.
[0006] In accordance with a first embodiment of the present
invention, a system comprising: a rotatable component comprising:
an airfoil portion comprising a first end, an opposite second end,
and suction and pressure surfaces located between the first end and
the opposite second end; a shank portion comprising a mount and a
slot, wherein the slot is positioned near a wall and is adjacent a
downstream edge of the airfoil portion; a platform portion that
connects the airfoil portion to the shank portion; a seal
comprising: an arm portion; and a hook portion; wherein the arm and
hook portions are shaped to mate with the slot such that the slot
restrains the movement of the seal; wherein the seal is sized to
substantially prevent a cooling flow from leaking through a shank
pocket.
[0007] In accordance with a second embodiment of the present
invention, a system comprising: a gas turbine comprising: a
compressor section and a turbine section; a turbine bucket
installed in the turbine section, wherein the turbine bucket
comprises: an airfoil comprising a tip, a base, and suction and
pressure surfaces that connected the tip and the base; a shank
comprising a mount and a slot, wherein the slot is positioned near
a surface that is adjacent an edge of the airfoil, and an end of
the slot is adjacent to a top portion of the mount; a platform
portion that connects the airfoil to the shank; a seal comprising:
an arm; and a hook; wherein the arm and hook are sized to allow
insertion into the slot such that the slot secures the movement of
the seal; wherein the seal has a width that substantially prevents
a cooling flow from leaking through a shank pocket, which is formed
between the shank portion of the rotatable component and an another
shank portion of an adjacent rotatable component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other features, aspects, and advantages of the
present invention may become better understood when the following
detailed description is read with reference to the accompanying
figures (FIGS) in which like characters represent like
elements/parts throughout the FIGS.
[0009] FIG. 1 is a schematic view, in cross-section, of a gas
turbine, illustrating the environment in which an embodiment of the
present invention operates.
[0010] FIG. 2 is a schematic view illustrating the cross-section of
the turbine section illustrated in FIG. 1.
[0011] FIGS. 3A and 3B, collectively FIG. 3, illustrate side and
isometric views of the rotating component illustrated in FIGS. 1
and 2.
[0012] FIG. 4 is a schematic illustrating an arrangement of
multiple rotating components, facing downstream.
[0013] FIG. 5 is a partial-isometric view of a rotating component,
in accordance with an embodiment of the present invention.
[0014] FIG. 6 illustrates a partial-isometric view of a rotating
component and a seal, in accordance with an embodiment of the
present invention.
[0015] FIG. 7 illustrates another partial-isometric view of a
rotating component and a seal, in accordance with an embodiment of
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] One or more specific embodiments of the present invention
will be described below. In an effort to provide a concise
description of these embodiments, all features of an actual
implementation may not be described in the specification. It should
be appreciated that in the development of any such actual
implementation, as in an engineering or design project, numerous
implementation-specific decisions are made to achieve the specific
goals, such as compliance with system-related and/or
business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such effort might be complex and time consuming, but would
nevertheless be a routine undertaking of design, fabrication, and
manufacture for those of ordinary skill having the benefit of this
disclosure.
[0017] Detailed example embodiments are disclosed herein. However,
specific structural and functional details disclosed herein are
merely representative for purposes of describing example
embodiments. Embodiments of the present invention may, however, be
embodied in many alternate forms, and should not be construed as
limited to only the embodiments set forth herein.
[0018] Accordingly, while example embodiments are capable of
various modifications and alternative forms, embodiments thereof
are illustrated by way of example in the figures and will herein be
described in detail. It should be understood, however, that there
is no intent to limit example embodiments to the particular forms
disclosed, but to the contrary, example embodiments are to cover
all modifications, equivalents, and alternatives falling within the
scope of the present invention.
[0019] The terminology used herein is for describing particular
embodiments only and is not intended to be limiting of example
embodiments. As used herein, the singular forms "a", "an" and "the"
are intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises",
"comprising", "includes" and/or "including", when used herein,
specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0020] Although the terms first, second, primary, secondary, etc.
may be used herein to describe various elements, these elements
should not be limited by these terms. These terms are only used to
distinguish one element from another. For example, but not limiting
to, a first element could be termed a second element, and,
similarly, a second element could be termed a first element,
without departing from the scope of example embodiments. As used
herein, the term "and/or" includes any, and all, combinations of
one or more of the associated listed items.
[0021] Certain terminology may be used herein for the convenience
of the reader only and is not to be taken as a limitation on the
scope of the invention. For example, words such as "upper",
"lower", "left", "right", "front", "rear", "top", "bottom",
"horizontal", "vertical", "upstream", "downstream", "fore", "aft",
and the like; merely describe the configuration shown in the FIGS.
Indeed, the element or elements of an embodiment of the present
invention may be oriented in any direction and the terminology,
therefore, should be understood as encompassing such variations
unless specified otherwise.
[0022] The present invention may be applied to the variety of
turbomachines that produce an exhaust fluid, such as, but not
limiting of, a heavy-duty gas turbine; an aero-derivative gas
turbine; or the like. An embodiment of the present invention may be
applied to either a single turbomachine or a plurality of
turbomachines. An embodiment of the present invention may be
applied to a turbomachine operating in a simple cycle or a combined
cycle configuration.
[0023] An embodiment of the present invention takes the form of a
seal that may substantially reduce cross-shank leakage. The
elements of the present invention may be fabricated of any material
that can withstand the operating environment under which
embodiments of the present invention may operate. Embodiments of
the seal may be connected to a wide variety of rotatable components
including, but not limited to, compressor blades, turbine buckets,
or the like.
[0024] Referring now to the Figures, where the various numbers
represent like elements throughout the several views, FIG. 1 is a
schematic view, in cross-section, of a gas turbine 100,
illustrating the environment in which an embodiment of the present
invention operates. FIG. 1 illustrates a known configuration of a
gas turbine 100 that includes: a compressor section 105; a
combustion section 130; and a turbine section 150.
[0025] Generally, the compressor section 105 includes a plurality
of rotating blades 110 and stationary vanes 115 structured to
compress a fluid. The compressor section 105 may also include a
compressor discharge casing 125.
[0026] Generally, the combustion section 130 includes a plurality
of combustion cans 135, a plurality of fuel nozzles 140, and a
plurality of transition sections 145. Within each of the combustion
cans 135, compressed air is received from the compressor section
105 and mixed with fuel received from a fuel source. The mixture is
ignited and creates a working fluid. The working fluid generally
flows downstream from the aft end of the plurality of fuel nozzles
140, downstream through the transition section 145, and into the
turbine section 150.
[0027] Generally, the turbine section 150 includes a plurality of
rotating components 155, and a plurality of stationary components
160. The turbine section 150 converts the energy of the working
fluid to a mechanical torque.
[0028] FIG. 2 is a schematic illustrating a close-up elevation view
of the turbine section 150 illustrated in FIG. 1. The plurality of
rotatable component 155 (hereinafter "turbine bucket") are commonly
arranged in a plurality of stages. For example, but not limited to,
FIGS. 1 and 2 illustrate an arrangement of three stages of turbine
buckets 155.
[0029] FIGS. 3A and 3B, collectively FIG. 3, illustrate side and
isometric views of the turbine buckets 155 of FIGS. 1 and 2. Each
of the turbine buckets 155 may comprise: an airfoil 165, a platform
167, and a shank 170.
[0030] The airfoil 165 may generally comprise a first end (or tip);
an opposite second end (or base); and suction and pressure surfaces
located between the first end and the opposite second end.
[0031] The shank 170 may comprise a mount 173, a slot 175, and a
shank pocket 177. An embodiment of the mount 173 may comprise any
mating shape that allows the turbine bucket 155 to mate with a
turbine wheel slot 405 on a turbine wheel 400, as illustrated in
FIG. 4.
[0032] The slot 175 functions to secure a seal 180. As illustrated
in FIG. 6, the shape of the slot 175 corresponds to that of the
seal 180, which allows mating to occur, as illustrated in FIG. 6.
An embodiment of the slot 175 may be vertically positioned near a
side wall that is substantially aligned with a downstream edge of
the airfoil 165, as illustrated in FIGS. 3 and 5. In an embodiment
of the present invention, an end of the slot 175 is adjacent to a
top portion of the mount 173. Here, an overall height of the slot
175 may extend from around the top portion of the mount 173 to a
bottom portion of the platform 167; as illustrated in FIG. 5.
However, other embodiments may comprise a shorter height.
[0033] The platform 167 provides the structure that connects the
bottom of the airfoil 165 to the top of the shank 170.
[0034] FIG. 4 is a schematic illustrating an arrangement, facing
downstream, of multiple rotating components 155 mounted on a
turbine wheel 400. Here, the mount 173 is illustrated in a dovetail
shape; however other forms of axially insertable mounts 173 may be
used with embodiments of the present invention. The mounts 173 are
inserted into the turbine wheel slots 405, located along the outer
periphery of the turbine wheel 400. This allows each turbine bucket
155 to be attached to the turbine wheel 400.
[0035] FIG. 4 also provides an overview of the flow path of the
working fluid and the cooling circuits; and how both of which
impact the turbine bucket 155. One cooling circuit utilizes the
collective shank pockets 177 formed by shanks 170 and platforms 167
of adjacent turbine buckets 155. This design may extract air from a
cooling purge 200 and uses that air to pressurize the shank pockets
177. The shank pocket 177 can also be pressurized using coolant
flows from other circuits. Once pressurized, the shank pockets 177
may supply cooling air to other locations on the platform 167.
Impingement cooling is often incorporated in this type of cooling
circuit to enhance heat transfer. The cooling air may exit the
shank pockets 177 through film cooling holes in the platform 167 or
through axial cooling holes which direct the air out of the shank
pocket 177.
[0036] Embodiments of the present invention provide a seal 180 that
may prevent leakage of the working fluid out of those shank pockets
177. The seal 180 may be very beneficial to the reducing
cross-shank leakage.
[0037] FIG. 6 is a partial-isometric view of a turbine bucket 155
and an embodiment of the seal 180, in accordance with an embodiment
of the present invention. The seal 180 is designed to take
advantage of two deterministic that are naturally acting on the
turbine buckets 155, as the gas turbine 105 operates. First, a
centrifugal force that may regularly apply tension. Second, is a
force due to the pressure difference between the shank pocket 177
and an aft cooling purge 600 that may constantly force the seal 180
into the slot 175. This second force may help to maintain a
relatively tight clearance.
[0038] An embodiment of the seal 180 may comprise the form of a
strip of metal that is inserted between adjacent turbine buckets
155 and attached near the dovetail region associated with the mount
173. Here, the seal 180 may comprise an arm 185 with a hook 190 at
an end. In an embodiment of the present invention, the hook 190 may
be located at the portion of the seal 180 that is located near the
mount 173. The hook 190 helps to position the seal 180 within the
mating slot 175.
[0039] The seal 180 may prevent coolant flow from leaking through
the shank pocket 177. The location of the seal 180 may be critical.
As the turbine bucket 155 begins to rotate, the seal 180 may be in
tension instead of compression. Here, compression may damage the
seal 180. Operationally, a large pressure difference typically
exists between the shank pocket 177 and the aft cooling purge 600.
Here, the force exerted on the seal 180 may prevent leakage, as
discussed.
[0040] FIG. 7 illustrates another partial-isometric view of a
rotating component 155 and a seal 180, in accordance with an
embodiment of the present invention. An embodiment of the seal 180
may be manufactured of a relatively thin sheet of metal that is
generally flexible to conform to the surfaces of the mating slot
175, and provide a desired seal against the intrusion of the
working fluid. The material utilized for the seal 180 should be
selected to withstand the pressures and temperatures associated
with a specific application and to allow for some plastic
deformation. The seal 180 may plastically deform in response to the
thermal and centrifugal loads to conform and fit the contours of
the slot 175. The plastic deformation may provide a desired seal
against the intrusion of the working fluid and may minimize leakage
of cooling/purge flow.
[0041] FIG. 7 illustrates reference locations for the following
dimensional ranges, in accordance with embodiments of the present
invention. However, it is not the intent to limit the present
invention to the following dimensional ranges. In an embodiment of
the present invention a width ("W") of the seal 180 may comprise a
range of from about 0.2 inches to about 1.0 inch. In an embodiment
of the present invention a length ("L") of the seal 180 may
comprise a range of from about 2.0 inches to about 10.0 inches. In
an embodiment of the present invention a thickness ("T") of the
seal 180 may comprise a range of from about 0.1 inches to about 0.5
inches. In an embodiment of the present invention a diameter ("D")
of the hook 190 may comprise a range of from about 0.2 inches to
about 1.0 inch.
[0042] In addition to the above benefits, embodiments of the
present invention may allow continued use or turbine buckets 155
having relatively larger shanks 170, while minimizing cross-shack
leakage with a simple seal 180. Embodiments of the seal 180 may
improve the overall performance and efficiency of the gas turbine
105.
[0043] Although specific embodiments have been illustrated and
described herein, those of ordinary skill in the art appreciate
that any arrangement, which is calculated to achieve the same
purpose, may be substituted for the specific embodiments shown and
that the invention has other applications in other environments.
This application is intended to cover any adaptations or variations
of the present invention. The following claims are in no way
intended to limit the scope of the invention to the specific
embodiments described herein.
[0044] As one of ordinary skill in the art will appreciate, the
many varying features and configurations described above in
relation to the several embodiments may be further selectively
applied to form other possible embodiments of the present
invention. Those in the art will further understand that all
possible iterations of the present invention are not provided or
discussed in detail, even though all combinations and possible
embodiments embraced by the several claims below or otherwise are
intended to be part of the instant application. In addition, from
the above description of several embodiments of the invention,
those skilled in the art will perceive improvements, changes, and
modifications. Such improvements, changes, and modifications within
the skill of the art are also intended to be covered by the
appended claims. Further, it should be apparent that the foregoing
relates only to the described embodiments of the present
application and that numerous changes and modifications may be made
herein without departing from the spirit and scope of the
application as defined by the following claims and the equivalents
thereof.
* * * * *