U.S. patent application number 11/523522 was filed with the patent office on 2009-06-11 for nozzle ring adhesive bonded blading for aircraft engine compressor.
This patent application is currently assigned to SNECMA MOTEURS. Invention is credited to Sandra Andrieu, Manuel Girard, Claude Marcel Mons, Francois Pierre Ribassin.
Application Number | 20090148283 11/523522 |
Document ID | / |
Family ID | 33427640 |
Filed Date | 2009-06-11 |
United States Patent
Application |
20090148283 |
Kind Code |
A1 |
Mons; Claude Marcel ; et
al. |
June 11, 2009 |
NOZZLE RING ADHESIVE BONDED BLADING FOR AIRCRAFT ENGINE
COMPRESSOR
Abstract
A compressor nozzle ring for an aircraft includes an inner
shroud, an outer shroud and a multiplicity of blades extending from
the inner shroud to the outer shroud. Each blade passes through the
inner shroud and is attached to it with sealing cement containing
an organic polymer adhesive. The adhesive is polyimide based.
Inventors: |
Mons; Claude Marcel;
(Savigny Le Temple, FR) ; Andrieu; Sandra;
(Roissy-en-Brie, FR) ; Girard; Manuel; (Vaux Le
Penil, FR) ; Ribassin; Francois Pierre; (Villabe,
FR) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
SNECMA MOTEURS
Paris
FR
|
Family ID: |
33427640 |
Appl. No.: |
11/523522 |
Filed: |
September 20, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10876610 |
Jun 28, 2004 |
7147434 |
|
|
11523522 |
|
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Current U.S.
Class: |
415/209.3 ;
415/200 |
Current CPC
Class: |
Y02T 50/60 20130101;
F05D 2300/434 20130101; Y02T 50/672 20130101; F01D 9/042 20130101;
F05D 2300/603 20130101; F05D 2230/23 20130101; Y10T 29/49885
20150115; F04D 29/542 20130101; F04D 29/023 20130101; Y10T 29/49323
20150115 |
Class at
Publication: |
415/209.3 ;
415/200 |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2003 |
FR |
03 07898 |
Claims
1. A compressor nozzle ring for an aircraft engine, said nozzle
ring comprising: an inner shroud; an outer shroud; and a
multiplicity of blades arranged circumferentially and extending
radially from the inner shroud to the outer shroud, each of the
blades passing through a corresponding aperture formed in the inner
shroud and being attached to the inner shroud with sealing cement
containing an organic polymer adhesive, wherein said adhesive is
polyimide based; wherein end regions of the blades project radially
inward beyond the inner shroud; wherein an insert disposed inside
the inner shroud and in proximity to the inner shroud surrounds, in
conjunction with the inner shroud and the blades, a continuous
space along the inside of the inner shroud that is filled with said
cement, and the continuous space filled with the cement continues
without a gap between adjacent blades of the blades and around the
end regions of the adjacent blades; and wherein said insert
surrounds the end regions of the adjacent blades including a
radially innermost area of the adjacent blades.
2. The nozzle ring according to claim 1, wherein the inner shroud
and/or the blades are made of titanium.
3. The nozzle ring according to claim 1, wherein said insert is a
flexible sheet.
4. The nozzle ring according to claim 3, wherein the flexible sheet
forms pockets at the end regions of the adjacent blades, said
pockets extending radially away from the inner shroud.
5. The nozzle ring according to claim 4, wherein the flexible sheet
is formed from several elements connected together in the
circumferential direction of the inner shroud with partial
overlap.
6. The nozzle ring according to claim 4, wherein the flexible sheet
is a glass fibre or carbon fibre fabric impregnated with
polyimide.
7. (canceled)
8. A compressor nozzle ring for an aircraft engine, comprising: an
inner shroud; an outer shroud; and a multiplicity of blades
arranged circumferentially and extending radially from the inner
shroud to the outer shroud, each of the blades passing through a
corresponding aperture formed in the inner shroud and being
attached to the inner shroud with sealing cement containing an
organic polymer adhesive, wherein said adhesive is polyimide based;
wherein end regions of the blades project radially inward beyond
the inner shroud; wherein an insert disposed inside the inner
shroud and in proximity to the inner shroud surrounds, in
conjunction with the inner shroud and the blades, a space that is
filled with said cement, and the space filled with the cement
continues without a gap between adjacent blades of the blades;
wherein said insert includes a multiplicity of rigid parts; and
wherein each of said rigid parts is interposed between the end
regions of the adjacent blades such that each individual part of
said rigid parts covers a side of the end regions of each of the
adjacent blades to surround the space that is filled with
cement.
9. The nozzle ring according to claim 8, wherein each of said rigid
parts is force fitted between said end regions.
10. The nozzle ring according to claim 8, wherein each of said
rigid parts extends over a length of arc greater than a
circumferential pitch of the adjacent blades.
11. The nozzle ring according to claim 10, wherein said rigid parts
have apertures to receive the end regions of the adjacent
blades.
12. The nozzle ring according to claim 8, wherein said rigid parts
are fixed to the inner shroud by said cement.
13. The nozzle ring according to claim 8, wherein said rigid parts
are made of aluminum alloy or magnesium alloy.
14. The nozzle ring according to claim 1, wherein said cement is in
film form.
15. The nozzle ring according to claim 1, wherein said cement is in
foam form.
16. The nozzle ring according to claim 1, wherein said
polyimide-based adhesive is capable of withstanding a temperature
of approximately 300.degree. C. without deterioration during
operation of the nozzle ring.
17. The nozzle ring according to claim 1, wherein the blades are
attached to the outer shroud by electron beam welding.
18. The nozzle ring according to claim 8, wherein said insert has
an angled U profile.
19. The nozzle ring according to claim 8, wherein said insert is a
non-hollow solid insert.
20-22. (canceled)
23. The nozzle ring according to claim 1, wherein the insert
includes a plurality of insert pieces and each of the plurality of
insert pieces surrounds the end regions including the radially
innermost area of a plurality of the blades.
24. (canceled)
Description
[0001] The invention relates to a compressor nozzle ring for an
aircraft engine including an inner shroud, an outer shroud, and a
multiplicity of blades arranged circumferentially and extending
radially from the inner shroud to the outer shroud, each blade
passing through a corresponding aperture formed in the inner shroud
and being attached to the latter by means of a sealing cement
containing an organic polymer adhesive.
[0002] Three techniques are currently employed to fix the blades of
a nozzle ring to the inner shroud, i.e. mechanical assembly by
bolting or riveting, high-temperature soldering using filler
metals, and bonding by means of filled silicone elastomers.
[0003] By way of example, U.S. Pat. No. 6,431,830 describes a
nozzle ring wherein the blades are attached to the inner shroud by
high-temperature soldering.
[0004] Mechanical solutions are disadvantageous by reason of their
high production cost as well as their complexity and weight.
[0005] The high-temperature soldering solution is not always
applicable depending on the constituent materials of the blades and
the shroud. In particular, when these components are made of
titanium, high-temperature soldering must be carried out at very
high temperatures resulting in prohibitive deformation.
[0006] The solution using silicone elastomer is effective, but the
service life of these elastomers diminishes when the operating
temperature of the compressor increases. Thus, for new generation
compressors operating continuously at temperatures in the region of
300.degree. C. in an atmosphere containing oil mist, silicone
elastomer based adhesives suffer embrittlement which limits the
practical service life to 100 hours.
[0007] The object of the invention is to overcome the
aforementioned drawbacks of the known fixing methods.
[0008] In particular, it is desired to obtain bonded joints that
are workable for 1000 hours at temperatures in the region of
300.degree. C.
[0009] The invention relates in particular to a nozzle ring of the
type described in the introduction, and provides that the adhesive
is polyimide-based.
[0010] Polyimide-based adhesives provide long-term resistance to
the atmospheres obtaining in the compressors of aircraft engines,
and it is possible to choose such an adhesive in relation to the
specified operating temperature, certain such adhesives being
capable of withstanding temperatures in the order of 300.degree.
C.
[0011] Optional features of the invention, whether complementary or
Alternative in character, are described below: [0012] The inner
shroud and/or the blades are made of titanium. [0013] End regions
of the blades project radially inward beyond the inner shroud.
[0014] An insert disposed inside the inner shroud and in proximity
to the latter delineates in conjunction with the inner shroud and
the blades a space that is filled with said cement. [0015] Said
insert takes the form of a flexible sheet. [0016] At the ends of
the blades, the flexible sheet forms pockets extending radially
away from the inner shroud. [0017] The flexible sheet is formed
from several elements connected together in the circumferential
direction of the inner shroud with partial overlap. [0018] The
flexible sheet is a glass or carbon fibre fabric impregnated with
polyimide. [0019] Said insert takes the form of a multiplicity of
rigid parts. [0020] Each of said rigid parts is interposed between
projecting regions of two consecutive blades. [0021] Each of said
rigid parts is force-fitted between said projecting regions. [0022]
Each of said rigid parts extends on a length of arc greater than
the circumferential pitch of the blades. [0023] Said rigid parts
present apertures to receive the projecting regions of the blades.
[0024] Said rigid parts are fixed to the inner shroud by means of
said cement. [0025] Said rigid parts are made of aluminium alloy or
magnesium alloy. [0026] Said cement is in film form. [0027] Said
cement is in the form of foam. [0028] Said polyimide-based adhesive
is capable of withstanding a temperature of approximately
300.degree. C. without deterioration during operation of the nozzle
ring. [0029] The blades are fixed to the outer shroud by electron
beam welding.
[0030] The characteristics and advantages of the invention are set
forth in greater detail in the description below with reference to
the attached figures.
[0031] FIG. 1 is a partial axial half-section of a compressor stage
to which the invention applies, showing an inner shroud, an outer
shroud, and a blade fixed thereto.
[0032] FIG. 2 is an enlarged part of FIG. 1 showing the inner
shroud and the blade regions adjacent thereto.
[0033] FIG. 3 is a partial view of the inside face of the inner
shroud developed in an imaginary flat plane.
[0034] FIG. 4 is a partial cross-sectional view in a plane
perpendicular to the engine axis, showing part of the inner shroud
and the root areas of the corresponding blades attached to the
latter according to a first embodiment of the invention.
[0035] FIG. 5 is a view similar to FIG. 4 relating to a second
embodiment of the invention.
[0036] FIG. 6 is a view similar to FIGS. 4 and 5 relating to a
third embodiment of the invention and showing in addition the full
length of the blades and part of the outer shroud.
[0037] FIG. 7 is a partial view of the inside face of the insert in
FIG. 6, developed in an imaginary flat plane.
[0038] In a conventional manner, the compressor stage shown in
FIGS. 1 to 3 includes an inner shroud 1 and an outer shroud 2, both
fixed, and a series of guide blades 3 extending in a general radial
direction from the inner shroud to the outer shroud. The blades 3
are arranged in the circumferential direction in a generally
uniform manner. The inner shroud 1 is pierced by apertures 4 of
which the shape matches the profile of the blades. Each of the
apertures is traversed by a blade 3 of which an end region 5
projects towards the engine axis beyond the aperture 4 and
therefore beyond the inside face 6 of the shroud 1. The blades 3
are fixed to the outer shroud 2, for example, by means of welds 7
made by electron beam welding.
[0039] The way the blades are attached to the inner shroud 1,
according to the invention, is described below.
[0040] In FIG. 4, the inside face 6 of the inner shroud 1 and the
projecting regions 5 of the blades 3 are covered by a flexible
sheet formed from several pieces of fabric 10-1, 10-2, 10-3, which
are connected together and partially overlap in the circumferential
direction. The flexible sheet follows the internal outline defined
by the face 6 and by the regions 5, and therefore extends away from
the shroud 1 to form pockets 11 wherein the regions 5 are seated.
In the example illustrated, the piece of fabric 10-2 covers the end
regions 5 of four blades 3, one of its marginal regions, referenced
12-2, being covered by a marginal region 13-3 of piece 10-3, while
its opposite marginal region 13-2 covers a marginal region 12-1 of
piece 10-1. Each of the aforementioned marginal regions is located
between two adjacent blades. In conjunction with the shroud 1 and
the blades 3, the flexible sheet delineates an annular space 14
which is filled by a film of a polyimide-based adhesive such as
that marketed by the company Cytec Fiberite Inc., product reference
FM 680, this adhesive also filling the gaps between the blades 3
and the periphery of the aperture 4. The flexible sheet 10-1, 10-2,
10-3 is advantageously formed from a glass or carbon fibre fabric
impregnated with polyimide.
[0041] To make the attachment illustrated in FIG. 4, after fitting
the blades, the projecting regions 5 of the blades and the internal
surface 6 of the shroud 1 are coated with adhesive foam, following
which the flexible sheet is applied and the assembly is treated at
a temperature in the order of 180.degree. C. to cure the adhesive,
applying light pressure to facilitate its adhesion to the parts
being assembled.
[0042] In the embodiment in FIG. 5, the volume allocated for the
adhesive composition is delineated towards the inside of the shroud
1 by a multiplicity of parts 20 made of aluminium alloy or
magnesium alloy, each of which is interposed between two adjacent
blades 3. Each part 2 presents, in the plane of the Figure, an
angled U profile of which the base 21 is applied against the inside
face 6 of the shroud 1 and of which the legs 22 are respectively
applied against the two adjacent blades. A thin film of a
polyimide-based adhesive such as that marketed by the company Cytec
Fiberite Inc., product reference FM 680, is interposed between the
parts 20 on the one hand, the shroud 1 and the end regions 5 of the
blades on the other hand, the adhesive also filling the gaps
between the blades and the periphery of the aperture 4. It is also
possible in this instance to use a polyimide foam such as that
marketed by the company Cytec Fiberite Inc., product reference FM
680-2.
[0043] The attachment in FIG. 5 can be made in the following
manner. The inside face 6 of the shroud and the regions 5 of the
blades are coated with a thin film of adhesive and the parts 20 are
then inserted, these being sized so that they are held in place by
force fit before the adhesive hardens, which is accomplished as in
the previous example by means of heat treatment.
[0044] The method of attachment in FIGS. 6 and 7 differs from that
in FIG. 5 in that the hollow parts 20 are replaced by solid parts
30-1, 30-2, 30-3 made of a polyimide foam such as that marketed by
the company Dupont de Nemours, product reference SF-0920, having a
relative density of 0.3, each of which extends over a length of arc
that is a multiple of the circumferential pitch of the blades, and
is traversed by apertures 31 to accommodate the projecting regions
5 of the blades. Two adjacent parts are separated by a narrow gap
32 located between two adjacent blades. Assembly is carried out in
the same manner as in FIG. 5, and the apertures 31 can be sized so
as to enable the parts 30-1, 30-2, 30-3 to be held in place by
friction on the regions 5 of the blades.
* * * * *