U.S. patent application number 09/748040 was filed with the patent office on 2002-06-27 for methods and apparatus for controlling bearing loads within bearing assemblies.
Invention is credited to Ceccopieri, Fernando, Haaser, Frederic Gardner, Handlesman, Steven Keith, Przytulski, James Charles, Willey, James Elbert.
Application Number | 20020081190 09/748040 |
Document ID | / |
Family ID | 25007733 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020081190 |
Kind Code |
A1 |
Przytulski, James Charles ;
et al. |
June 27, 2002 |
Methods and apparatus for controlling bearing loads within bearing
assemblies
Abstract
An orifice plate assembly for a gas turbine engine that
facilitates extending a useful life of bearing assemblies within
the gas turbine engine is described. Each orifice plate assembly is
coupled in flow communication with an engine air source, and
includes a first body portion and a second body portion. The first
body portion includes a channel and a flow opening. The channel is
sized to receive the second body portion, such that the second body
portion may slide with respect to the first body portion. The
orifice plate assembly is adjustable during engine operation to
regulate bearing loading.
Inventors: |
Przytulski, James Charles;
(Fairfield, OH) ; Willey, James Elbert; (West
Chester, OH) ; Haaser, Frederic Gardner; (Cincinnati,
OH) ; Ceccopieri, Fernando; (Loveland, OH) ;
Handlesman, Steven Keith; (Cincinnati, OH) |
Correspondence
Address: |
GENERAL ELECTRIC COMPANY
ANDREW C HESS
GE AIRCRAFT ENGINES
ONE NEUMANN WAY M/D H17
CINCINNATI
OH
452156301
|
Family ID: |
25007733 |
Appl. No.: |
09/748040 |
Filed: |
December 22, 2000 |
Current U.S.
Class: |
415/1 |
Current CPC
Class: |
F01D 17/105 20130101;
F01D 9/065 20130101; F04D 29/0516 20130101; F04D 27/0207 20130101;
F05D 2270/11 20130101; F01D 25/16 20130101; F01D 3/00 20130101 |
Class at
Publication: |
415/1 |
International
Class: |
F01D 001/00 |
Claims
What is claimed is:
1. A method for regulating bearing loads of a gas turbine engine
bearing assembly using an orifice plate assembly, the orifice plate
assembly including a first body portion and a second body portion,
the first body portion including an opening extending therethrough,
said method comprising the steps of: coupling the orifice plate
assembly to the gas turbine engine in flow communication with the
bearing assembly; supplying air through the orifice plate assembly
first body portion opening; and coupling the orifice plate assembly
second body portion to the first body portion to regulate an amount
of air flowing through the orifice plate first body portion
opening, such that the second body portion slides with respect to
the first body portion.
2. A method in accordance with claim 1 wherein the first body
portion includes an upper surface, a channel, and a lower surface,
the channel extending from the upper surface towards the lower
surface, said step of coupling the orifice plate assembly second
body portion to the first body portion further comprising the step
of sliding the orifice second body portion relative to the orifice
first body portion on the engine to change an amount of air flowing
through the orifice plate first body portion opening.
3. A method in accordance with claim 1 wherein the second body
portion includes an upper surface and a lower surface, the second
body upper surface including a plurality of graduation lines, said
step of coupling the orifice plate assembly second body portion to
the first body portion further comprising the step of using the
graduation lines to align the second body portion with respect to
the first body portion.
4. A method in accordance with claim 3 wherein the second body
portion includes an upper surface and a lower surface, said step of
coupling the orifice plate assembly second body portion to the
first body portion further comprising the step of inserting the
second body portion within the first body portion, such that the
second body portion upper surface is substantially co-planar with
the first body portion upper surface.
5. A method in accordance with claim 1 wherein the first body
portion includes an alignment opening, the second body portion
includes an alignment opening, said method further comprising the
step of extending a fastener through the first and second body
portion alignment slots to secure the second body portion in
position relative to the first body portion.
6. Apparatus for a gas turbine engine including a bearing assembly,
said apparatus comprising an orifice plate sub-assembly comprising
a first body portion and a second body portion, said first body
portion comprising an opening extending therethrough, said second
body portion configured to slide relative to said first body
portion to regulate an amount of fluid flowing through said first
body portion opening for controlling bearing load of said bearing
assembly.
7. Apparatus in accordance with claim 6 wherein said orifice plate
sub-assembly second body portion comprises an alignment opening
configured to receive a fastener therethrough.
8. Apparatus in accordance with claim 6 wherein said orifice plate
sub-assembly first body portion further comprises a first alignment
opening, said orifice plate sub-assembly second body portion
comprises a second alignment opening, said first alignment opening
and said second alignment opening configured to receive a fastener
therethrough for securing said second body portion to said first
body portion.
9. Apparatus in accordance with claim 8 wherein said orifice plate
sub-assembly second body portion second alignment opening comprises
a slot.
10. Apparatus in accordance with claim 6 wherein said orifice plate
sub-assembly first body portion comprises a channel sized to
receive said second body portion therein.
11. Apparatus in accordance with claim 10 wherein said orifice
plate sub-assembly second body portion comprises an upper surface
and lower surface, said orifice plate sub-assembly first body
portion comprises an upper surface and a lower surface, said first
body portion channel configured to receive said second body
portion, such that said second body portion upper surface
substantially coplanar with said first body portion upper
surface.
12. Apparatus in accordance with claim 6 wherein said orifice plate
sub-assembly second body portion comprises a plurality of
graduation lines configured to align said second body portion with
respect to said orifice plate sub-assembly first body portion, said
second body portion configured to be repositioned with respect to
said first body portion while installed on the engine to regulate
an amount of fluid flowing through said first body portion opening
for controlling bearing load of said bearing assembly.
13. A gas turbine engine comprising: a bearing assembly; and an
orifice plate assembly configured to regulate a bearing load of
said bearing assembly, said orifice plate assembly comprising a
first body portion and a second body portion, said first body
portion comprising an opening extending therethrough, said second
body portion coupled to said first body portion to regulate an
amount of fluid flowing through said first body portion opening for
controlling bearing loading of said bearing assembly, such that
said second body portion slides relative to said first body
portion.
14. A gas turbine engine in accordance with claim 13 wherein said
orifice plate assembly second body portion configured to be
repositioned with respect to said first body portion while attached
to said engine.
15. A gas turbine engine in accordance with claim 14 wherein said
orifice plate assembly first body portion comprises an upper
surface, a channel, and a lower surface, said channel extending
from said upper surface towards said lower surface and sized to
receive said orifice plate assembly second body portion
therein.
16. A gas turbine engine in accordance with claim 15 wherein said
orifice plate assembly second body portion comprises an upper
surface and a lower surface, said second body portion received
within said orifice plate assembly first body portion such that
said second body portion upper surface substantially co-planar with
said first body portion upper surface.
17. A gas turbine engine in accordance with claim 15 wherein said
orifice plate assembly first body portion further comprises an
alignment opening configured to receive a fastener
therethrough.
18. A gas turbine engine in accordance with claim 17 wherein said
orifice plate assembly second body portion further comprises an
alignment opening, said first and second body portion alignment
openings configured to receive a fastener therethrough to secure
said second body portion in position relative to said first body
portion.
19. A gas turbine engine in accordance with claim 18 wherein said
orifice plate assembly second body portion alignment opening
comprises a slot.
20. A gas turbine engine in accordance with claim 15 wherein said
orifice plate assembly second body portion comprises a plurality of
graduation lines configured to align said second body portion with
respect to said first body portion.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to gas turbine engines and,
more particularly, to methods and apparatus for regulating bearing
loads within gas turbine engine bearing assemblies.
[0002] Gas turbine engines include a high pressure compressor, a
combustor, and a high pressure turbine. The high pressure
compressor includes a rotor, and a plurality of stages. The rotor
is supported with a plurality of bearing assemblies that include an
inner race, an outer race, and a plurality of rolling elements
between the inner and outer races. Maintaining bearing loads within
pre-defined limits during engine operation facilitates extending a
useful life of the bearing assembly.
[0003] To regulate the bearing load, at least some known gas
turbine engines use compressor bleed air. The bleed air is routed
through delivery lines including orifice plate assemblies. The
orifice plate assemblies are multi-piece assemblies and each
orifice plate assembly includes a discretely sized opening that
limits an amount of airflow through the orifice plate assembly and
thus regulates a pressure/flow from the air sources.
[0004] During engine operation, when engine parameters indicate
that bearing load is exceeding pre-defined limits, engine operation
is stopped and the orifice plate assembly is replaced with a
different orifice plate assembly that has a different sized
opening. Because each orifice plate assembly is discretely sized, a
large inventory of plates is often maintained. Because of the
complexity of the multi-piece orifice plate assemblies, replacing
the orifice plate assemblies is often a time-consuming and costly
process.
BRIEF SUMMARY OF THE INVENTION
[0005] In an exemplary embodiment, an orifice plate assembly for a
gas turbine engine facilitates extending a useful life of bearing
assemblies within the gas turbine engine. Each orifice plate
assembly is coupled within the engine in flow communication with an
engine air source, and each includes a first body portion and a
second body portion. The first body portion includes a channel and
a flow opening. The channel is sized to receive the second body
portion, such that the second body portion may slide with respect
to the first body portion. More specifically, the second body
portion may be positioned to cover any portion or all of the first
body portion flow opening.
[0006] During engine operation, when parameters measured indicate
that bearing loads are approaching pre-defined limits, the orifice
plate assembly may be adjusted while the engine is operating to
regulate air pressure and flow to facilitate maintaining bearing
loads within the limits. More specifically, to adjust the orifice
plate assembly, the second body portion is loosened from the first
body portion and is repositioned with respect to the first body
portion. As the second body portion is repositioned, a
cross-sectional flow area through the first body portion flow
opening is changed. When bearing loads are reestablished within the
pre-defined limits, the second body portion is re-secured to the
first body portion. As a result, the orifice plate assembly
facilitates extending a useful life of a bearing assembly in a
highly reliable and cost-effective manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic illustration of a gas turbine
engine;
[0008] FIG. 2 is a cross-sectional view of a portion of the gas
turbine engine shown in FIG. 1;
[0009] FIG. 3 is a plan view of an orifice plate assembly used with
the gas turbine engine shown in FIG. 2; and
[0010] FIG. 4 is a side view of the orifice plate assembly shown in
FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0011] FIG. 1 is a schematic illustration of a gas turbine engine
10 including at least one compressor 12, a combustor 16, a high
pressure turbine 18, a low pressure turbine 20, an inlet 22, and an
exhaust nozzle 24 connected serially. In one embodiment, engine 10
is an LM2500+ engine commercially available from General Electric
Company, Cincinnati, Ohio. Compressor 12 and turbine 18 are coupled
by a first shaft 26. Engine 10 also includes a centerline axis of
symmetry 32.
[0012] In operation, air flows into engine inlet 22 through
compressor 12 and is compressed. The compressed air is then
delivered to combustor 16 where it is mixed with fuel and ignited.
Airflow from combustor 16 drives rotating turbines 18 and 20 and
exits gas turbine engine 10 through exhaust nozzle 24.
[0013] FIG. 2 is a cross-sectional view of a portion of gas turbine
engine 10. Compressor 14 includes a plurality of stages 50, and
each stage 50 includes a row of rotor blades 52 and a row of stator
vanes 56. Rotor blades 52 are circumferentially spaced apart, and
are typically supported by rotor spools and disks 58 connected to
rotor shaft 26. Rotor blades 52 and stator vanes 56 are coaxial
with respect to engine centerline axis 32. A row of
circumferentially spaced apart stator vanes 56 extend between each
row of adjacent rotor blades 52 and are supported with an annular
outer engine casing 62.
[0014] Compressor bleed air is extracted from high pressure
compressor 14 from intermediate stages 66 of compressor 14 and used
to regulate bearing loads of bearing assemblies 70 coupled to an
engine frame 72. In one embodiment, bearing loads of a #4B thrust
bearing assembly are regulated using high pressure compressor
recoup compressor air 78. In another embodiment, bearing loads of a
#7B thrust bearing assembly are regulated using stage 13 high
pressure compressor bleed 76.
[0015] More specifically, a plurality of air delivery lines 80 are
coupled in flow communication to various stages of compressor 14,
and are used for supplying fluid flow for controlling bearing loads
of bearing assemblies 70 and #7B bearing assemblies. Each air
delivery line 80 includes an orifice plate assembly 82. Orifice
plate assembly 82, described in more detail below, is adjustable
and may be adjusted during engine operation to regulate
pressure/flow through delivery lines 80 from compressor 14.
[0016] In an exemplary embodiment, bearing assembly 70 is enclosed
within a sealed annular compartment 90 radially bounded by rotor
shaft 26 and support frame 72. Bearing assembly 70 includes a
paired race 91, a plurality of rolling elements 92, and a cage 94.
More specifically, paired race 91 includes an outer race 96 and an
inner race 98 that is radially inward from outer race 96. Each
rolling element 92 is between inner race 98 and outer race 96, and
in rolling contact with inner and outer races 98 and 96,
respectively. Furthermore, rolling elements 92 are spaced
circumferentially by cage 94.
[0017] During operation, engine 10 uses high pressure compressor
recoup air 78 and high pressure compressor bleed 76 supplied
through delivery lines 80 to control bearing loads. More
specifically, bearing loads are maintained between pre-determined
limits to facilitate extending useful bearing life. Orifice plate
assemblies 82 regulate the pressure/flow from compressor sources 78
and 76. More specifically, when parameters measured during engine
operation indicate that bearing loads are approaching
pre-determined limits, orifice plate assemblies 82 may be adjusted
during idle engine operation to control bearing loads.
[0018] FIG. 3 is a plan view of orifice plate assembly 82 that may
be used with gas turbine engine 10 (shown in FIGS. 1 and 2). FIG. 4
is a side view of orifice plate assembly 82. Orifice plate assembly
82 includes a first body portion 100 and a second body portion 102.
First body portion 100 includes an upper surface 104, a lower
surface 106, and a channel 108, and has a thickness 110 measured
between upper and lower surfaces 104 and 106, respectively. First
body portion 100 also includes an inlet side 112 and a rear side
114 connected with a pair of sidewalls 116 and 118. An axis of
symmetry 119 extends from first body portion inlet side 112 to rear
side 114.
[0019] First body portion channel 108 is sized to receive second
body portion 102 therein. More specifically, channel 108 extends a
distance 120 into first body portion 100 towards first body portion
lower surface 106 from first body portion upper surface 104.
Channel depth 120 is smaller than first body portion thickness 110.
Additionally, channel 108 has a width 122 that is smaller than a
width 124 of first body portion 100. Furthermore, channel 108 also
extends inward towards first body portion rear side 114 from first
body portion inlet side 112 for a length 126. Channel length 126 is
smaller than a length 128 of first body portion 100 measured
between inlet and rear sides 112 and 114, respectively.
[0020] First body portion 100 also includes a flow opening 130 and
a plurality of attachment openings 132. Flow opening 130 extends
from first body portion upper surface 104 to lower surface 106.
More specifically, flow opening 130 is co-axially positioned with
respect to first body portion 100 within channel 108. A width 133
of flow opening 130 is smaller than channel width 122, and a length
134 of flow opening 130 is smaller than channel length 126. In one
embodiment, flow opening 130 has a substantially rectangular
cross-sectional profile. In another embodiment, flow opening 130
has a non-rectangular cross sectional profile.
[0021] First body portion attachment openings 132 extend through
first body portion 100 from first body portion upper surface 104 to
lower surface 106. Each attachment opening 132 has a diameter 140
sized to receive a fastener (not shown) therethrough to secure each
orifice plate assembly 82 to engine 10 (shown in FIGS. 1 and 2).
More specifically, attachment openings 132 extend through first
body portion 100 between first body portion channel 108 and
sidewalls 116 and 118.
[0022] First body portion 100 also includes an alignment opening
144. Alignment opening 144 is between flow opening 130 and first
body portion inlet side 112 within channel 108. Alignment opening
144 extends through first body portion 100 from first body portion
upper surface 104 to lower surface 106, and has a diameter 146
sized to receive an alignment fastener 148 therethrough. Alignment
fastener 148 secures orifice plate assembly second body portion 102
in position with respect to first body portion 100. In one
embodiment, alignment fastener 148 is a threaded bolt and locking
nut.
[0023] Orifice plate assembly second body portion 102 includes an
upper surface 160 and a lower surface 162, and has a thickness 164
measured between upper and lower surfaces 160 and 162,
respectively. Second body portion thickness 164 is smaller than
first body portion thickness 110. In one embodiment, orifice plate
assembly second body portion thickness 164 is approximately equal
first body portion channel depth 120.
[0024] Orifice second body portion 102 also includes an inlet side
166 and a rear side 168 connected with a pair of sidewalls 170 and
172, and an alignment slot opening 174. Second body portion 102
also includes an axis of symmetry 176 extending from second body
portion inlet side 166 to rear side 168. Second body portion axis
of symmetry 176 is substantially co-linear with first body portion
axis of symmetry 119.
[0025] Orifice second body portion 102 has a width 180 measured
between sidewalls 170 and 172 that is smaller than orifice first
body portion width 124. Second body portion width 180 is slightly
smaller than first body portion channel width 122, such that second
body portion 102 is received in slidable contact within first body
portion channel 108. In one embodiment, orifice second body portion
length 182 is approximately equal first body portion channel length
126. Accordingly, first body portion channel 108 is sized to
receive second body portion 102, such that second body portion
upper surface 160 is substantially co-planar with first body
portion upper surface 104. Furthermore, first body portion channel
108 permits second body portion 102 to slide therein with respect
to first body portion 100.
[0026] Orifice second body portion alignment slot opening 174 is
co-axially aligned with respect to axis of symmetry 176. Alignment
slot opening 174 has a width 186 that is approximately equal first
body portion alignment opening diameter 146. Accordingly, orifice
second body portion alignment slot opening 174 is sized to receive
alignment fastener 148 therethrough. Alignment slot opening 174 has
a length 188 measured between an inlet end 190 and a rear end
192.
[0027] Alignment slot inlet end 190 is a distance 194 from second
body portion inlet side 166, and alignment slot rear end 192 is a
distance 196 from second body portion rear side 168. Alignment slot
opening length 188 is longer than first body portion flow opening
length 134.
[0028] A plurality of graduation lines 200 extend from second body
portion sidewall 170 to sidewall 172. More specifically, graduation
lines extend from second body portion alignment slot opening 174 to
each respective sidewall 170 and 172, to provide reference
indications used in aligning second body portion 102 with respect
to first body portion 100. In one embodiment, second body portion
102 also includes reference numbers (not shown) used in aligning
second body portion 102 with respect to first body portion 100.
[0029] During assembly of orifice plate assembly 82, fasteners are
inserted through first body portion attachment openings 132 to
secure orifice plate assembly 82 in flow communication with a
respective air delivery line 80 (shown in FIG. 2). More
specifically, orifice plate assembly 82 is secured such that first
body portion flow opening 130 is in flow communication with an air
delivery line 80. Second body portion 102 is then coupled to first
body portion 100. More specifically, second body portion 102 is
inserted within first body portion channel 108 such that second
body portion rear side 168 initially enters first body portion
channel 108. Second body portion 102 is then slid towards first
body portion rear side 114, such that second body portion upper
surface 160 is substantially co-planar with first body portion
upper surface 104.
[0030] After second body portion 102 has been slid into position
with respect to first body portion 100 and is in a desired
position, as indicated by second body portion graduation lines 200,
a portion 210 of first body portion flow opening 130 may be covered
by second body portion 102. Portion 210 is infinitely variable and
is determined by a relative position of second body portion 102
with respect to first body portion 100. More specifically, second
body portion alignment slot opening length 188 permits second body
portion to be positioned such that any percentage of flow opening
130 from approximately zero percent to approximately one hundred
percent may be covered with second body portion 102.
[0031] When a desired percentage of first body portion flow opening
130 is covered by second body portion 102, alignment fastener 148
is extended through first body portion alignment opening 144 and
second body portion alignment slot opening 174. Alignment fastener
148 is then tightened to secure second body portion 102 in position
relative to first body portion 100.
[0032] During engine operation, when parameters measured during
engine operation indicate bearing loads are approaching the
pre-defined limits, orifice plate assembly may be adjusted after
engine shutdown to regulate the pressure/flow to maintain bearing
loads within the limits to facilitate extending bearing assembly
useful life. More specifically, alignment fastener 148 is loosened
and orifice plate assembly second body portion 102 is repositioned
with respect to first body portion 100 to ensure a cross-sectional
flow area through first body portion flow opening 130 maintains an
appropriate bearing load. Because second body portion 102 is slid
with respect to first body portion 100, orifice adjustments are
infinitely variable. In addition, because orifice plate assembly 82
is variably adjustable, orifice plate assembly 82 may be used for
fine tuning bearing loads as performance parameters and bearing
loads drift during a useful life of engine 10.
[0033] The above-described orifice plate assembly for a gas turbine
engine is cost-effective and highly reliable. The orifice plate
assembly includes a second body portion that is received within a
first body portion. A position of the second body portion is
infinitely variable with respect to the first body portion to
regulate bearing loads. Furthermore, the orifice plate assembly may
be adjusted during engine operation. Thus, the orifice plate
assembly facilitates extending a useful life of engine bearing
assemblies in a cost-effective and reliable manner.
[0034] 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.
* * * * *