U.S. patent application number 12/103762 was filed with the patent office on 2008-08-14 for method of cooling an accessory gearbox.
Invention is credited to DAVID BROUILLET.
Application Number | 20080193282 12/103762 |
Document ID | / |
Family ID | 35539874 |
Filed Date | 2008-08-14 |
United States Patent
Application |
20080193282 |
Kind Code |
A1 |
BROUILLET; DAVID |
August 14, 2008 |
METHOD OF COOLING AN ACCESSORY GEARBOX
Abstract
The accessory gearbox (AGB) has at least one coolant passage
between the AGB and the accessory for externally cooling the
accessory without coolant flow inside the accessory.
Inventors: |
BROUILLET; DAVID; (St.
Basile Le Grand, CA) |
Correspondence
Address: |
OGILVY RENAULT LLP (PWC)
1981 MCGILL COLLEGE AVENUE, SUITE 1600
MONTREAL
QC
H3A 2Y3
omitted
|
Family ID: |
35539874 |
Appl. No.: |
12/103762 |
Filed: |
April 16, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10886603 |
Jul 9, 2004 |
7373771 |
|
|
12103762 |
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Current U.S.
Class: |
415/175 |
Current CPC
Class: |
Y02T 50/60 20130101;
F16H 57/0415 20130101; F02C 7/32 20130101; F02C 7/12 20130101; Y02T
50/675 20130101 |
Class at
Publication: |
415/175 |
International
Class: |
F01D 25/08 20060101
F01D025/08 |
Claims
1. A method of cooling a gas turbine accessory comprising the steps
of: circulating a coolant liquid from an engine coolant circuit
around an external side surface of the accessory, and circulating
the coolant liquid within the engine to provide at least one of
cooling and lubrication to at least one other part of the
engine.
2. The method as defined in claim 1, wherein the step of
circulating coolant liquid around the accessory includes the step
of circulating coolant liquid between an inlet of a coolant liquid
passage and an outlet of the coolant liquid passage to exchange
heat between the coolant liquid and the external side surface of
the accessory.
3. The method as defined in claim 2, wherein the accessory is at
least partially inserted in an accessory gearbox (AGB).
4. The method as defined in claim 3, wherein the accessory has a
circular cross section.
5. The method as defined in claim 3, wherein the coolant liquid
passage is at least partially axially delimited by a pair of
spaced-apart seals provided between an internal wall surface of the
AGB and the external side surface of the accessory, the external
side surface being radially inward of the internal wall
surface.
6. The method as defined in claim 3, wherein an internal wall
surface of the AGB and the external side surface of the accessory
define the coolant liquid passage.
7. The method as defined in claim 3, wherein the coolant liquid
directly contacts the external side surface of the accessory to
thereby cool the accessory.
8. The method as defined in claim 7, wherein the accessory is
substantially enveloped by the internal wall surface of the
AGB.
9. The method as defined in claim 7, wherein the accessory is
sealingly received by the internal wall surface of the AGB.
10. The method as defined in claim 1, wherein the coolant liquid
comprises oil and the coolant liquid circuit includes a main oil
circuit communicating with at least one main bearing cavity in the
engine.
Description
CROSS-RELATION APPLICATION The present application is a divisional
of U.S. patent application Ser. No. 10/886,603 filed Jul. 9, 2004,
the contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0001] The technical field relates generally to cooling
arrangements and methods of cooling, more particularly the cooling
an accessory used in an accessory gearbox of a gas turbine
engine.
BACKGROUND
[0002] Gas turbine engines are often equipped with various
mechanically-driven accessories which are connected to a casing
referred to an accessory gearbox (AGB).
[0003] Some accessories are generating intense heat during their
operation and for this reason, they require cooling. Oil in the AGB
is often used for cooling the accessories, such as the
starter/generator unit. Oil passages are provided inside the
starter/generator unit and heat is exchanged between the oil and
the internal parts of the starter/generator unit. This arrangement
has been used in the past in an extensive number of designs.
However, it requires oil connectors between the AGB and the
electrical device, and also internal oil passages in the electrical
device.
SUMMARY
[0004] In one aspect, there is provided a method of cooling a gas
turbine accessory comprising the steps of: circulating engine oil
from an engine oil circuit around an external side surface of the
accessory, and circulating the oil within the engine to provide at
least one of cooling and lubrication to at least one other part of
the engine.
[0005] Still other aspects and features will be better understood
with reference to the following description and the appended
figures.
DESCRIPTION OF THE FIGURES
[0006] FIG. 1 schematically shows a generic gas turbine engine to
illustrate an example of a general environment in which is located
an accessory gearbox.
[0007] FIG. 2 is a schematic cross-sectional view of an example of
an accessory located in a housing of an accessory gearbox
incorporating the new arrangement.
[0008] FIG. 3 is a view similar to FIG. 2, showing a variant of the
new arrangement.
[0009] FIG. 4 is a view similar to FIGS. 2 and 3, showing another
variant of the new arrangement.
[0010] FIG. 5 is a block diagram illustrating an example of a
coiling oil path of a gas turbine engine.
DETAILED DESCRIPTION
[0011] FIG. 1 illustrates an example of a gas turbine engine 10 of
a type provided for use in subsonic flight, generally comprising in
serial flow communication a fan 12 through which ambient air is
propelled, a multistage compressor 14 for pressurizing the air, a
combustor 16 in which the compressed air is mixed with fuel and
ignited for generating an annular stream of hot combustion gases,
and a turbine section 18 for extracting energy from the combustion
gases.
[0012] FIG. 2 schematically illustrates an accessory or other gas
turbine-mounted device 20, such as a starter, generator or
starter-generator unit, which is secured into an accessory gearbox
(AGB) 30. The accessory 20 is partially embedded within a housing
32 of the AGB 30, thus having a significant amount, such as more
than half, of its volume within the housing 32. The housing 32 of
the AGB 30 is generally internally defined by an internal wall
surface 34. This internal wall surface 34 can be shaped and
configured to sealingly receive the external side surface 22 of the
accessory 20.
[0013] An annular oil passage 36 is provided between the internal
wall surface 34 of the AGB 30 and the external side wall surface 22
of the accessory 20. The example illustrated in FIG. 2 shows the
passage 36 being located in the internal wall surface 34 of the AGB
30. As shown in FIG. 3, passage 36 can also be defined in the
external side surface 22 of the accessory 20, or passage 36 can
also be defined by recesses in a combination of both surface 34
surface 22, as shown in FIG. 4, or simply by any internal space
defined within the AGB and that may be immediately adjacent surface
34. Opposite o-ring seals 40 are provided at both ends to ensure
sealing.
[0014] As can be appreciated, the arrangement described herein
creates a cooling jacket around the accessory 20 and allows heat to
be exchanged, which may negate the need for additional cooling
means, such as internal oil passages inside the accessory 20.
[0015] Oil is provided by the gas turbine's oil system (not
depicted in this figure) to the annular oil passage 36 from at
least one inlet oil passage 42, such as one located in the internal
wall surface 34 of the AGB 30. Similarly, oil exits the annular oil
passage 36 through at least one outlet oil passage 44 located in
the internal wall surface 34 of the AGB 30, for return to the oil
system. These inlet and outlet oil passages 42,44 may be configured
and disposed to generate a constant flow of oil in the various
regions of the annular oil passage 36. The flow is sufficient to
provide the desired cooling to accessory 20.
[0016] FIG. 5 schematically illustrates an overall example of an
oil circuit of a gas turbine engine 10. Oil is pumped from a tank
50 and sent to a filter unit 52. A heat exchanger 54 cools the oil.
At least some of the oil is then provided to the accessory 20 for
cooling thereof. The oil then circulates to the bearing cavities of
the engine 10, for instance in the various bearings therein. Oil is
then supplied to the AGB 30 before being returned to the tank
50.
[0017] The above description is meant to be exemplary only, and one
skilled in the art will recognize that changes may be made without
departing from the scope of what is disclosed. For example, the
improvements are not limited to a single annular oil passage 36.
Two or more oil passages can be used and may communicate in
parallel or serially with the source. The shape of the annular oil
passage 36 may be any desirable and is not necessarily with a
purely circular path but can include spiral-shaped paths and/or
other cooling-enhancing features such as trip strips, etc. Although
oil is often the coolant with which the system can be used, any
suitable cooling liquid may be used. Still other modifications will
be apparent to those skilled in the art, in light of a review of
the present disclosure, and such modifications are intended to fall
within the scope of the appended claims.
* * * * *