U.S. patent application number 14/171381 was filed with the patent office on 2015-08-06 for variable clearance mechanism for use in a turbine engine and method of assembly.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is General Electric Company. Invention is credited to Kevin Joseph Barb, Joseph Anthony Cotroneo.
Application Number | 20150218959 14/171381 |
Document ID | / |
Family ID | 53754419 |
Filed Date | 2015-08-06 |
United States Patent
Application |
20150218959 |
Kind Code |
A1 |
Barb; Kevin Joseph ; et
al. |
August 6, 2015 |
VARIABLE CLEARANCE MECHANISM FOR USE IN A TURBINE ENGINE AND METHOD
OF ASSEMBLY
Abstract
A variable clearance mechanism for use in a turbine engine is
provided that includes a stationary component, a plurality of
articulating seal members coupled to the stationary component, and
a biasing mechanism including an actuation ring. The variable
clearance mechanism varies the position of stationary seal members
to provide variable bucket tip clearance as a function of an
operating condition of the turbine engine. The biasing mechanism is
coupled to the plurality of articulating seal members for use in
selectively translating the plurality of articulating seal members
when the actuation ring is rotated circumferentially relative to
the stationary component.
Inventors: |
Barb; Kevin Joseph; (Clifton
Park, NY) ; Cotroneo; Joseph Anthony; (Clifton Park,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
53754419 |
Appl. No.: |
14/171381 |
Filed: |
February 3, 2014 |
Current U.S.
Class: |
415/173.1 ;
277/301; 277/411 |
Current CPC
Class: |
F01D 11/22 20130101 |
International
Class: |
F01D 11/22 20060101
F01D011/22 |
Claims
1. A variable clearance mechanism for use in a turbine engine, said
mechanism comprising: a stationary component; a plurality of
articulating seal members coupled to said stationary component; and
a biasing mechanism comprising an actuation ring, said biasing
mechanism coupled to said plurality of articulating seal members
for use in selectively translating said plurality of articulating
seal members when said actuation ring is rotated circumferentially
relative to said stationary component.
2. The mechanism in accordance with claim 1, wherein said actuation
ring is rotated in a first circumferential direction to translate
said plurality of articulating seal members radially inward, and
said actuation ring is rotated in a second circumferential
direction to translate said plurality of articulating seal members
radially outward.
3. The mechanism in accordance with claim 2, wherein a degree of
translation of said plurality of articulating seal members is
selected based on a degree of rotation of said actuation ring in
the first and second circumferential directions.
4. The mechanism in accordance with claim 1, wherein said biasing
mechanism comprises at least one lever coupled between said
actuation ring and at least one of said plurality of articulating
seal members, wherein said at least one lever is configured to
convert circumferential movement of said actuation ring into
substantially linear movement of said plurality of articulating
seal members.
5. The mechanism in accordance with claim 4, wherein said biasing
mechanism comprises at least one lever coupled between said
actuation ring and each of said plurality of articulating seal
members such that said plurality of articulating seal members are
simultaneously translated when said actuation ring is rotated
circumferentially.
6. The mechanism in accordance with claim 1, wherein said biasing
mechanism comprises an actuator coupled to said actuation ring,
said actuator configured to induce circumferential rotation to said
actuation ring.
7. The mechanism in accordance with claim 1, wherein said actuation
ring is configured to remain at a substantially uniform distance
from said stationary component as said actuation ring rotates
circumferentially.
8. A turbine engine comprising: a rotor blade assembly comprising a
plurality of rotor blades; a stationary component; a plurality of
articulating seal members coupled to said stationary component; and
a biasing mechanism comprising an actuation ring, said biasing
mechanism coupled to said plurality of articulating seal members
for use in selectively translating said plurality of articulating
seal members when said actuation ring is rotated circumferentially
relative to said stationary component.
9. The turbine engine in accordance with claim 8, wherein said
actuation ring is rotated in a first circumferential direction to
translate said plurality of articulating seal members radially
inward, and said actuation ring is rotated in a second
circumferential direction to translate said plurality of
articulating seal members radially outward.
10. The turbine engine in accordance with claim 9, wherein a
clearance between said plurality of articulating seal members and
said plurality of rotor blades is selected based on a degree of
rotation of said actuation ring in the first and second
circumferential directions.
11. The turbine engine in accordance with claim 8, wherein said
biasing mechanism comprises at least one lever coupled between said
actuation ring and at least one of said plurality of articulating
seal members, wherein said at least one lever is configured to
convert circumferential movement of said actuation ring into
substantially linear movement of said plurality of articulating
seal members.
12. The turbine engine in accordance with claim 8 further
comprising a slide track coupled to adjacent articulating seal
members, said slide track configured to substantially maintain
alignment between said adjacent articulating seal members as they
selectively translate linearly.
13. The turbine engine in accordance with claim 8, wherein said
biasing mechanism comprises a biasing element coupled to at least
one of said plurality of articulating seal members, said biasing
element configured to ensure the selective translation of said at
least one of said plurality of articulating seal members is
responsive to the circumferential rotation of said actuation
ring.
14. The turbine engine in accordance with claim 8 further
comprising a rack and pinion assembly associated with said
actuation ring and configured to facilitate translating said
plurality of articulating seal members in response to rotation of
said actuation ring relative to said stationary component.
15. A method of assembling a variable clearance mechanism for use
in a turbine engine, said method comprising: providing a stationary
component; coupling a plurality of articulating seal members to the
stationary component; coupling an actuation ring to the plurality
of articulating seal members such that the actuation ring is
configured to selectively translate the plurality of articulating
seal members when the actuation ring is rotated circumferentially
relative to the stationary component.
16. The method in accordance with claim 15, wherein coupling the
actuation ring to the plurality of articulating seal members
comprises coupling at least one lever between the actuation ring
and the plurality of articulating seal members.
17. The method in accordance with claim 16, wherein coupling at
least one lever comprises coupling the at least one lever between
the actuation ring and each of the plurality of articulating seal
members such that the plurality of articulating seal members are
simultaneously translated when the actuation ring is rotated
circumferentially.
18. The method in accordance with claim 16 further comprising
forming a slot in at least one of the stationary component and the
at least one lever, wherein the slot facilitates sliding engagement
between the at least one lever and at least one of the actuation
ring, the stationary component, and the plurality of articulating
seal members.
19. The method in accordance with claim 15 further comprising
coupling an actuator to the actuation ring, wherein the actuator is
configured to induce circumferential rotation to the actuation
ring.
20. The method in accordance with claim 15 further comprising
defining a distance between the stationary component and the
actuation ring that remains substantially uniform as the actuation
ring rotates circumferentially.
Description
BACKGROUND
[0001] The field of the present disclosure relates generally to
turbine engines and, more specifically, to a variable clearance
mechanism that includes articulating seal members for use in a
turbine engine.
[0002] Known turbines experience several different phases of
operation including, but not limited to, start-up, warm-up,
steady-state, shutdown, and cool-down. In at least some of such
known turbines, clearances between turbine rotor blade tips and
inner surfaces of the surrounding seal members are controlled to
facilitate improving operating efficiency. Such clearances
generally vary as the turbine transitions from one operational
phase to another. More particularly, each operational phase has
different operating conditions associated with it, such as
temperature, pressure, and rotational speed, which will induce
changes in the clearances between turbine components, including
static and moving components within the turbine.
[0003] In at least some known turbines, the clearances between the
turbine rotor blades and the seal members are also controlled to
prevent contact-related damage therebetween as the turbine
transitions between operational phases. For example, in at least
some known turbines, cold, or assembly, clearances are set to be no
larger than required for steady-state operation to account for
thermal and mechanical differences in the turbine when
transitioning between phases of operation. Moreover, as described
above, turbine efficiency depends at least in part on the clearance
between tips of the rotating blades and seal members coupled to the
surrounding casing. If the clearance is too large, enhanced gas
flow may unnecessarily leak through the clearance gaps, thus
decreasing the turbine's efficiency.
[0004] At least some known turbines use abradable and/or labyrinth
seals that facilitate reducing leakage flow through the clearance
gap. The leakage flow adversely affects turbine performance by
bypassing flow around the blades that could be used to provide
useful output for the turbine. Moreover, at least some known
turbines facilitate reducing operating clearances by forming
components from materials having a relatively low coefficient of
thermal expansion, and/or with active translation of moveable seal
members.
BRIEF DESCRIPTION
[0005] In one aspect of the disclosure, a variable clearance
mechanism for use in a turbine engine is provided. The mechanism
includes a stationary component, a plurality of articulating seal
members coupled to the stationary component, and a biasing
mechanism including an actuation ring. The biasing mechanism is
coupled to the plurality of articulating seal members for use in
selectively translating the plurality of articulating seal members
when the actuation ring is rotated circumferentially relative to
the stationary component.
[0006] In another aspect of the disclosure, a turbine engine is
provided. The turbine engine includes a rotor blade assembly
including a plurality of rotor blades, a stationary component, a
plurality of articulating seal members coupled to the stationary
component, and a biasing mechanism including an actuation ring. The
biasing mechanism is coupled to the plurality of articulating seal
members for use in selectively translating the plurality of
articulating seal members when the actuation ring is rotated
circumferentially relative to the stationary component.
[0007] In yet another aspect of the disclosure, a method of
assembling a variable clearance mechanism for use in a turbine
engine is provided. The method includes providing a stationary
component, coupling a plurality of articulating seal members to the
stationary component, and coupling an actuation ring to the
plurality of articulating seal members such that the actuation ring
is configured to selectively translate the plurality of
articulating seal members when the actuation ring is rotated
circumferentially relative to the stationary component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic illustration of an exemplary steam
turbine engine.
[0009] FIG. 2 is an enlarged view of an exemplary turbine rotor
blade that may be used in the turbine engine shown in FIG. 1.
[0010] FIG. 3 is an axial view of an exemplary variable clearance
mechanism that may be used in the turbine engine shown in FIG. 1
and in a first operational position.
[0011] FIG. 4 is an enlarged axial view of the variable clearance
mechanism shown in FIG. 3.
[0012] FIG. 5 is an axial view of the variable clearance mechanism
shown in FIG. 3 and in a second operational position.
[0013] FIG. 6 is an axial view of an alternative variable clearance
mechanism that may be used in the turbine engine shown in FIG.
1.
[0014] FIG. 7 is an axial view of a further alternative variable
clearance mechanism.
DETAILED DESCRIPTION
[0015] Embodiments of the present disclosure relate to systems and
methods for use in controlling blade tip clearance in a turbine
engine. More specifically, the systems described herein include
articulating seal members that are easily configured to accommodate
variations in the blade tip clearance during transient and/or
steady-state operational phases of the turbine engine. The
articulating seal members are coupled to a biasing mechanism that
selectively translates the seal members radially during transitions
between the transient and steady-state operational phases. The
biasing mechanism includes an actuation ring and a plurality of
levers coupled, either directly or indirectly, between the
actuation ring and the seal members. As the actuation ring rotates
circumferentially, the levers convert the circumferential motion of
the actuation ring to a radial motion induced to the seal members.
As such, the blade tip clearance may be selectively controlled to
facilitate maintaining the integrity of the blade tips and seal
members to improve the efficiency of the turbine engine.
[0016] As used herein, the terms "axial" and "axially" refer to
directions and orientations that extend substantially parallel to a
longitudinal axis of a turbine engine. Moreover, the terms "radial"
and "radially" refer to directions and orientations that extend
substantially perpendicular to the longitudinal axis of the turbine
engine. In addition, as used herein, the terms "circumferential"
and "circumferentially" refer to directions and orientations that
extend arcuately about the longitudinal axis of the turbine engine.
It should also be appreciated that the term "fluid" as used herein
includes any medium or material that flows, including, but not
limited to, air, gas, liquid and steam.
[0017] FIG. 1 is a schematic view of an exemplary steam turbine
engine 10. While FIG. 1 describes an exemplary steam turbine
engine, it should be noted that the variable clearance mechanism
and methods described herein are not limited to any one particular
type of turbine engine. One of ordinary skill in the art should
appreciate that the variable clearance mechanism and methods
described herein may be used with any rotary machine, including a
gas turbine engine, in any suitable configuration that enables such
an apparatus, system, and method to operate as further described
herein.
[0018] In the exemplary embodiment, turbine engine 10 is a
single-flow steam turbine engine. Alternatively, turbine engine 10
may be any type of steam turbine, such as, without limitation, a
low-pressure turbine engine, an opposed-flow high-pressure and
intermediate-pressure steam turbine combination, a double-flow
steam turbine engine, and/or other steam turbine types. Moreover,
as discussed above, the present invention is not limited to only
being used in steam turbine engines and can be used in other
turbine systems, such as gas turbine engines.
[0019] In the exemplary embodiment shown in FIG. 1, turbine engine
10 includes a plurality of turbine stages 12 that are coupled to a
rotatable shaft 14. A casing 16 is divided longitudinally into an
upper half section 18 and a lower half section (not shown). Upper
half section 18 includes a high pressure (HP) inlet 20 and a low
pressure (LP) outlet 22. Shaft 14 extends through casing 16 along a
centerline axis 24, and is supported by bearings (not shown) at a
journal 30. End packings 26 and 28 facilitate restricting operating
fluid from escaping casing 16.
[0020] In the exemplary embodiment, turbine engine 10 also includes
a stator component 44 coupled to casing 16. Casing 16 and stator
component 44 each extend circumferentially about shaft 14. Shaft 14
includes a plurality of turbine stages 12 through which
high-pressure, high-temperature operating fluid 40 is passed via
turbine inlet 46. Turbine stages 12 include a plurality of nozzles
48. Turbine engine 10 may include any number of nozzles 48 that
enables turbine engine 10 to operate as described herein. For
example, turbine engine 10 may include more or less nozzles 48 than
are illustrated in FIG. 1. Turbine stages 12 also include a
plurality of rotor blades 38. Turbine engine 10 may include any
number of rotor blades 38 that enables turbine engine 10 to operate
as described herein. Operating fluid 40 enters turbine inlet 46
through HP inlet 20 and flows along shaft 14 through turbine stages
12, and exiting through outlet 22.
[0021] During operation, high pressure and high temperature
operating fluid 40 is channeled to turbine stages 12 from an energy
source, such as a boiler (not shown), wherein thermal energy is
converted to mechanical rotational energy by turbine stages 12.
More specifically, operating fluid 40 is channeled through casing
16 from HP inlet 20 where it impacts the plurality of rotor blades
38, coupled to shaft 14 to induce rotation of shaft 14 about
centerline axis 24. Operating fluid 40 exits casing 16 at LP outlet
22. Operating fluid 40 may then be channeled to the boiler (not
shown) where it may be reheated or channeled to other components of
the system, e.g., a condenser (not shown).
[0022] FIG. 2 is an enlarged view of an exemplary turbine stage 12
that may be used in turbine engine 10 shown in FIG. 1. In the
exemplary embodiment, turbine stage 12 includes nozzle 48 and rotor
blade 38 that includes an airfoil 27 and a dovetail 29, which is
coupled to a rotor disk 33. Rotor disk 33 is coupled to rotate with
shaft 14 (shown in FIG. 1). Each nozzle 48 includes a vane 17
coupled to a first stationary component 19 and to a second
stationary component 21 within casing 16 (shown in FIG. 1). Each
vane 17 remains stationary relative to shaft 14. An exemplary
clearance 23 is defined between a tip 25 of airfoil 27 and an
articulating seal member 104. Components such as casing 16,
components 19 and 21, vane 17 and airfoil 27 expand when heated as
turbine engine 10 transitions between a transient operational phase
(for example, a start-up phase and a warm-up phase) and a
steady-state operational phase. As a result, clearance 23 will vary
as turbine engine transitions between different turbine operational
phases. Clearance 23 may will also vary as a result from other
operational factors such as vibrational forces, bearing oil film
thickness, and/or bearing alignment.
[0023] In the exemplary embodiment, turbine engine 10 also includes
a variable clearance mechanism 100. Variable clearance mechanism
100 includes a biasing mechanism 102 and articulating seal member
104 coupled to biasing mechanism 102. Biasing mechanism 102
selectively translates articulating seal member 104 to facilitate
modifying clearance 23 as turbine engine 10 transitions between a
transient operational phase and a steady-state operational
phase.
[0024] FIG. 3 is an axial view of variable clearance mechanism 100
that may be used in turbine engine 10 (shown in FIG. 1) in a first
operational position 106, FIG. 4 is an enlarged axial view of
variable clearance mechanism 100, and FIG. 5 is an axial view of
variable clearance mechanism 100 in a second operational position
108. In the exemplary embodiment, variable clearance mechanism 100
includes first stationary component 19, a plurality of articulating
seal members 104 positioned radially inward from first stationary
component 19, and biasing mechanism 102 that selectively translates
articulating seal members 104 generally radially during operation.
Biasing mechanism 102 includes an actuation ring 110 that is
radially outward from first stationary component 19 and that is
coupled, either directly or indirectly, to articulating seal
members 104. Alternatively, actuation ring 110 is located relative
to stationary component 19 at any position that enables biasing
mechanism 102 to function as described herein. At least one lever
112 is coupled to actuation ring 110, first stationary component
19, and at least one articulating seal member 104. Actuation ring
110 extends about first stationary component 19 at any length that
enables variable clearance mechanism 100 to function as described
herein. For example, actuation ring 110 may extend between about 0
degrees and about 360 degrees about centerline axis 24 of turbine
engine 10. Moreover, actuation ring 110 remains a substantially
uniform circumferential distance from first stationary component 19
as actuation ring 110 is rotated.
[0025] Biasing mechanism 102 also includes an actuator 114 coupled
to actuation ring 110. Actuator 114 may be any device that induces
circumferential rotation to actuation ring 110 during operation.
For example, exemplary actuators may include, but are not limited
to, a motor-driven device, a hydraulic device, and a pneumatic
device. In the exemplary embodiment, actuator 114 includes a casing
116 and a piston 118 selectively translatable within casing 116.
Piston 118 is coupled to actuation ring 110 via a pivot point 120.
In operation, piston 118 selectively translates generally linearly
within casing 116, and pivot point 120 converts the linear motion
of piston 118 into a circumferential rotation of actuation ring
110.
[0026] Referring to FIG. 3, turbine engine 10 is in a transient
operational phase. During the transient operational phase,
components of turbine engine 10 are in thermal and vibrational
flux, which may result in variations in clearance 23 between tip 25
of airfoil 27 (each shown in FIG. 2) and first stationary component
19. Such flux is caused by at least one of varying expansion and/or
contraction of components of turbine engine 10 due to differing
rates of thermal expansion as such components may be formed from
different materials, varying thermal gradients within each
component, and/or a vibratory response caused by rotor imbalance.
As such, in the exemplary embodiment, variable clearance mechanism
100 is in first operational position 106 when turbine engine 10 is
in a transient operational phase. More specifically, variable
clearance mechanism 100 translates articulating seal members 104
radially outward to accommodate variations in clearance 23 and to
facilitate reducing contact and abrasion between tip 25 and
articulating seal members 104.
[0027] In the exemplary embodiment, articulating seal members 104
are translated radially outward by rotating actuation ring 110 in a
first circumferential direction 122. More specifically,
articulating seal members 104 are coupled to actuation ring 110
such that rotation of actuation ring 110 in first circumferential
direction 122 facilitates increasing clearance 23 and increasing a
gap 124 formed between adjacent articulating seal members 104.
Actuation ring 110 may be rotated in first circumferential
direction 122 by any circumferential amount that enables variable
clearance mechanism 100 to function as described herein. As such,
clearance 23 is selected as a function of a degree of
circumferential rotation of actuation ring 110. Moreover, levers
112 are coupled between actuation ring 110 and each articulating
seal member 104 to enable articulating seal members 104 to
selectively translate simultaneously as actuation ring 110 is
rotated.
[0028] Referring to FIG. 4, levers 112 are coupled to actuation
ring 110, first stationary component 19, and articulating seal
members 104 such that rotation of actuation ring 110 is converted
into radial movement of articulating seal members 104. More
specifically, levers 112 enable actuation ring 110 to selectively
translate articulating seal members 104 radially without expanding
and/or contracting radially itself. In the exemplary embodiment,
each lever 112 includes a first end 126, an opposing second end
128, and a middle portion 130 extending therebetween. First end 126
is coupled to actuation ring 110, middle portion 130 is coupled to
first stationary component 19, and second end 128 is coupled to
articulating seal member 104 via a series of pins 132. During
operation, lever 112 rotates about middle portion 130 as actuation
ring 110 rotates circumferentially. As such, the coupling at middle
portion 130 defines a fixed pivot point, and the couplings at first
and second ends 126 and 128 each define moving pivot points. More
specifically, in the exemplary embodiment, slots 134 are defined in
each of first and second ends 126 and 128 to enable sliding
engagement between pins 132 and slots 134. As such, the sliding
engagement between pins 132 and slots 134 facilitates accommodating
any radial mismatch between a length L of lever 112 and a distance
D defined between actuation ring 110 and articulating seal members
104.
[0029] In the exemplary embodiment, biasing mechanism 102 includes
a biasing element 135 that facilitates ensuring articulating seal
members 104 are biased in a radially inward direction as turbine
engine 10 (shown in FIG. 1) transitions between operational phases.
More specifically, as the circumferential movement of actuation
ring 110 causes articulating seal members 104 to translate
substantially linearly, a lag between the movement of actuation
ring 110 and the movement of articulating seal members 104 may be
caused by the sliding engagement between pins 132 and slots 134 in
levers 112. As such, in the exemplary embodiment, biasing element
135 is coupled between articulating seal members 104 and lever 112
to ensure the sliding engagement between pins 132 and slots 134 is
responsive to the circumferential rotation of actuation ring 110.
Alternatively, biasing element 135 may be coupled between
articulating seal members 104 and any suitable component that
enables biasing mechanism 102 to function as described herein. An
exemplary biasing element 135 includes, but is not limited to, a
spring.
[0030] Referring to FIG. 5, turbine engine 10 is in a steady-state
operational phase. During steady-state operations, components of
turbine engine 10 reach substantial thermal equilibrium such that
clearance 23 between tip 25 and articulating seal members 104
remains substantially uniform during operation. In the exemplary
embodiment, variable clearance mechanism 100 remains in second
operational position 108 when turbine engine 10 is in a
steady-state operational phase. More specifically, variable
clearance mechanism 100 translates articulating seal members 104
radially inward to facilitate decreasing clearance 23, to
facilitate reducing fluid leakage through clearance 23, and thus to
facilitate increasing the efficiency of turbine 10.
[0031] In the exemplary embodiment, articulating seal members 104
are translated radially inward by rotating actuation ring 110 in a
second circumferential direction 136. More specifically,
articulating seal members 104 are coupled to actuation ring 110
such that rotating actuation ring 110 in second circumferential
direction 136 facilitates decreasing clearance 23 and reducing gap
124 (shown in FIG. 3) defined between adjacent articulating seal
members 104. Actuation ring 110 is rotated in second
circumferential direction 136 to any angular distance that enables
variable clearance mechanism 100 to function as described herein.
As such, clearance 23 is selected as a function of a degree of
circumferential rotation of actuation ring 110. Moreover, as
described above, levers 112 are coupled between actuation ring 110
and each articulating seal member 104 such that articulating seal
members 104 selectively translate simultaneously when actuation
ring 110 is rotated circumferentially.
[0032] FIG. 6 is an axial view of an alternative variable clearance
mechanism 200. In the exemplary embodiment, variable clearance
mechanism 200 includes a rack and pinion assembly 138 coupled
between actuation ring 110 and stationary component 19 that
facilitates translating seal members 104 in response to rotation of
actuation ring 110 relative to first stationary component 19. Rack
and pinion assembly 138 includes a plurality of pinions 140 coupled
to and spaced circumferentially about first stationary component
19, and a toothed rack 142 defined on an inner radial portion 144
of actuation ring 110. Levers 112 are coupled to pinions 140 such
that rotation of pinions 140 selectively translates articulating
seal members 104 substantially radially. When actuator 114 induces
circumferential rotation to actuation ring 110, toothed rack 142
engages and rotates pinions 140. As such, clearance 23 is selected
as a function of a degree of rotation of pinions 140.
[0033] FIG. 7 is an axial view of an alternative variable clearance
mechanism 300. In the exemplary embodiment, variable clearance
mechanism 300 includes a slide track 145 coupled between adjacent
articulating seal members 104 and lever 112 coupled to slide track
145. Slide track 145 facilitates maintaining alignment between
adjacent articulating seal members 104 as they selectively
translate substantially radially during operation of variable
clearance mechanism 300. For example, articulating seal members 104
translate circumferentially along slide track 145 as articulating
seal members 104 selectively translate substantially radially.
First stationary component 19 (shown in FIG. 2) includes slots 146
formed therein to facilitate sliding engagement between pins 132
and slots 146. As such, the sliding engagement between pins 132 and
slots 146 facilitates accommodating for the radial mismatch between
length L of lever 112 and distance D (shown in FIG. 4) between
actuation ring 110 and seal members 104. Moreover, in the exemplary
embodiment, only one lever 112 is coupled between actuation ring
110 and slide track 145 to facilitate translating seal members 104
radially.
[0034] The systems and methods described herein facilitate
clearance control between a rotor assembly and adjustable seal
members in a turbine engine. More specifically, the variable
clearance mechanism described herein includes a biasing mechanism
that selectively translates the adjustable seal members radially to
modify a clearance between the rotor assembly and the seal members
while closing a clearance between adjacent seal members. The
biasing mechanism includes an actuation ring coupled to the seal
members with a system of levers. The levers facilitate selectively
translating the seal members radially as the actuation ring rotates
circumferentially. By actuating the seal members with the
circumferential rotation of the actuation ring, the biasing
mechanism is not limited by radial movement constraints defined by
the casing of the turbine, and can be actuated with a single
mechanism. As such, the variable clearance mechanism facilitates
selectively modifying the clearance between the rotor assembly and
the adjustable seal members as the turbine engine transitions
between operational phases.
[0035] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *