U.S. patent application number 10/941806 was filed with the patent office on 2006-10-12 for turobjet axisymmetric nozzle controlled hot flap shutter.
This patent application is currently assigned to SNECMA MOTEURS. Invention is credited to Stephane Blanchard, Thierry Pancou, Guillaume Sevi.
Application Number | 20060225426 10/941806 |
Document ID | / |
Family ID | 34179005 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060225426 |
Kind Code |
A1 |
Sevi; Guillaume ; et
al. |
October 12, 2006 |
TUROBJET AXISYMMETRIC NOZZLE CONTROLLED HOT FLAP SHUTTER
Abstract
A controlled hot flap shutter for a turbojet nozzle includes a
friction surface made of metal, and including straight lateral
flanks to reduce the gap between each controlled hot flap shutter
and the tracking flap shutters adjacent thereto.
Inventors: |
Sevi; Guillaume; (Ivry Sur
Seine, FR) ; Blanchard; Stephane; (Chartrettes,
FR) ; Pancou; Thierry; (Saintry Sur Seine,
FR) |
Correspondence
Address: |
C. IRVIN MCCLELLAND;OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
SNECMA MOTEURS
PARIS
FR
|
Family ID: |
34179005 |
Appl. No.: |
10/941806 |
Filed: |
September 16, 2004 |
Current U.S.
Class: |
60/771 |
Current CPC
Class: |
F02K 1/12 20130101; F02K
1/80 20130101; F02K 1/805 20130101; F05D 2300/603 20130101; Y02T
50/672 20130101; Y02T 50/60 20130101; F05D 2300/21 20130101 |
Class at
Publication: |
060/771 |
International
Class: |
F02K 1/06 20060101
F02K001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2003 |
FR |
03 50577 |
Claims
1. Turbojet axisymmetric nozzle controlled hot flap shutter,
pivoting around an axis perpendicular to the turbojet axis,
comprising: a ceramic composite material flap shutter plate and a
friction surface placed widthways under the flap shutter plate and
intended to remain in contact with a nozzle seal, said seal being
made of metal, wherein the friction surface is made of metal.
2. Controlled hot flap shutter according to claim 1, wherein the
friction surface is limited by two lateral flanks, roughly
perpendicular to the friction surface and intended to be positioned
opposite and close to the lateral flanks of an adjacent tracking
flap shutter.
3. Controlled hot flap shutter according to claim 1, wherein the
friction surface is integrated in the controlled hot flap
shutter.
4. Controlled hot flap shutter according to claim 3, wherein the
friction surface integrated in the a frame during the casting of
the controlled hot flap shutter.
5. Controlled hot flap shutter according to claim 1, wherein the
friction surface is supported by a support part which is added and
attached to the controlled hot flap shutter.
6. Controlled hot flap shutter according to claim 5, wherein the
support part is attached between a frame of the controlled hot flap
shutter and the flap shutter plate by assembly screws.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a variable ejection cross-section
ejection nozzle, mounted on the downstream end of a fixed circular
cross-section structure of a turbojet hot gas ejection channel,
particularly for military aircraft.
STATE OF THE PRIOR ART AND PROBLEM THAT ARISES
[0002] Some military aircraft equipped with turbojets must be able
to carry out missions under subsonic or supersonic flight
conditions. Therefore, these turbojets are equipped with a heating
system and an axisymmetric or other type nozzle, two-dimensional,
for example. For turbo-engines equipped with heating systems, the
nozzle must have a variable cross-section. As a result, the flap
shutters of the inner ejection channel, referred to as "hot flap
shutters", are therefore each mounted pivoting around an axis
perpendicular to the turbojet axis, tangent to a diameter which is
close to the ejection diameter.
[0003] Each of said flap shutters is controlled for pivoting by a
common synchronized tilting device. Between each controlled hot
flap shutter, there is a tracking flap shutter which is not
controlled and wherein the orientation is carried out by the two
controlled hot flap shutters adjacent thereto. Therefore, each
tracking flap shutter has lateral parts subject to friction with a
controlled hot flap shutter.
[0004] In addition, at this level of the hot gas ejection channel,
there is a nozzle seal which is in contact with each of the
tracking flap shutters and the controlled hot flap shutters.
[0005] However, the various pivoting movements of the flap shutters
induce wear due to friction, particularly at the upstream contact
zone between each flap shutter and the nozzle gasket(s). In fact,
it is important to note that these flap shutters are made of a
ceramic matrix composite material. However, the nozzle seals are
made of metal.
[0006] In other words, rapid and mutual wear problems relating to
the nozzle seal and the flap shutter friction surface, due to
relative friction, occur at the trailing edge of the nozzle and the
flap shutter hinge pin, thus affecting the service life of the
nozzle components.
[0007] In addition, the use of ceramic matrix composite materials
requires these flap shutters to only have very low radii of
curvature, i.e. angular shapes. This is a drawback for the
tightness between each tracking flap shutter and said two adjacent
controlled hot flap shutters. In effect, with reference to FIG. 1,
while the tracking flap shutter 1 may have a compact shape, this is
not the case for the controlled hot flap shutter 2 which takes on a
deformed sheet shape. This results in a relatively large gap 4
being created between the lateral edge of the tracking flap shutter
1 and the surface of the controlled hot flap shutter 2 and the
external surface of the nozzle seal 3.
[0008] The invention aims to remedy these drawbacks.
SUMMARY OF THE INVENTION
[0009] To this end, the main subject of the invention is a turbojet
axisymmetric nozzle controlled hot flap shutter, pivoting around an
axis perpendicular to the turbojet axis, comprising:
[0010] a ceramic composite material flap shutter plate; and
[0011] a friction surface placed widthways under the flap shutter
plate and intended to remain in contact with a nozzle seal, said
seal being made of metal.
[0012] According to the invention, the friction surface is made of
metal.
[0013] In this way, the metal/metal contact of said surface with
respect to the nozzle seal generates much less wear at this
point.
[0014] In order to improve the tightness between a tracking flap
shutter, the adjacent control hot flap shutter and the nozzle seal,
the friction surface is limited laterally by two lateral flanks
roughly perpendicular to the friction surface and intended to be
positioned opposite and close to the lateral flanks of the adjacent
tracking flap shutters.
[0015] In a first preferential embodiment of the invention, the
friction surface is integrated in the controlled hot flap
shutter.
[0016] Preferentially, this integration of the friction surface in
the controlled hot flap shutter is carried out during the casting
of the controlled hot flap shutter.
[0017] In a second embodiment, the friction surface is an added
part attached to the controlled hot flap shutter.
[0018] In this case, the attachment may be made using assembly
screws holding a friction surface support part between the flap
shutter plate and a flap shutter frame.
BRIEF DESCRIPTION OF FIGURES
[0019] The invention and its different technical characteristics
will be understood more clearly on reading the following detailed
description of two embodiments of the invention.
[0020] They are accompanied by several figures representing
respectively:
[0021] FIG. 1, a sectional view, already described, of the junction
between a tracking flap shutter and a controlled hot flap shutter
according to the prior art;
[0022] FIG. 2, a cavalier view of a controlled hot flap shutter
according to a first embodiment of the invention;
[0023] FIG. 3, two controlled hot flap shutters surrounding a
tracking flap shutter according to the first embodiment of the
invention;
[0024] FIG. 4, an exploded view of a controlled hot flap shutter
according to a second embodiment of the invention; and
[0025] FIG. 5, the junction between a tracking flap shutter and a
controlled hot flap shutter according to the invention.
DETAILED DESCRIPTION OF TWO EMBODIMENTS OF THE INVENTION
[0026] With reference to FIG. 2, a first embodiment of the
controlled hot flap shutter is as follows. A main body 29 opposite
two parallel reinforcements supports on each side a bush 21
intended to receive the flap shutter control lever. The lower part
of the body 29 comprises a pivoting hole 26 around the axis from
which the flap shutter pivots. The lower part also comprises a
bearing plate 27 intended to receive the additional shape of a flap
shutter plate 22 consisting of a heat-resistant material such as a
ceramic matrix composite. The rear lower part, just below one end
of the flap shutter plate 22, comprises a tapered friction surface
24, with a slightly convex cross-section. In addition, length ways,
it is slightly dished so as to show a slightly concave shape
widthways on the flap shutter. It is limited laterally by two
lateral flanks 25 which are perpendicular to the tapered shape
shown by said friction surface 24.
[0027] In this embodiment, the flap shutter plate 22 is an integral
part of the flap shutter. In effect, it is inserted into a groove
28 above the friction surface 24 and is attached during the
manufacture of the bearing plate 27 of the flap shutter,
particularly during the casting. A large proportion of the
controlled hot flap shutter is made of metal, while the flap
shutter plate 22 is made of ceramic matrix composite material.
[0028] FIG. 3 contains two controlled hot flap shutters 20
surrounding a tracking flap shutter 10. Each flap shutter plate 22
of the controlled hot flap shutters 20 laterally overlaps the
corresponding flap shutter plate 12 of the tracking flap shutter
10. In order to improve the tightness of all the flap shutter
bases, at their friction surface 24 for the controlled hot flap
shutters 20 and 14 for the tracking flap shutters 10, the edges or
lateral flanks 25 of each friction surface 24 of the controlled hot
flap shutters 20 must be located as close as possible to the
corresponding adjacent lateral flanks 15 of the adjacent tracking
flap shutters 10. However, given that the lateral flanks 25 of the
friction surfaces 24 are perpendicular to said surfaces, as a
result, at each flap shutter plate 22, the lateral flanks 25 of the
controlled hot flap shutters 20 and the lateral flanks 15 of the
tracking flap shutters 10 can be positioned opposite each other
while being practically parallel and therefore very close. FIG. 4
allows a clearer understanding, compared to FIG. 1, of the
improvement of the tightness at this point. In effect, the lateral
flanks 15 of the tracking flap shutters 10 and 25 of the controlled
hot flap shutters 20 are very close to each other and the gap 4 in
FIG. 1 is considerably reduced, which improves the tightness of the
assembly at this point.
[0029] The embodiment represented in FIG. 5 shows a flap shutter
plate 32 which is intended to be attached to its controlled hot
flap shutter 40 by means of several assembly screws 41 and nuts 42.
In this case, the contact surface 44 is supported by a support part
47 which is not attached to the frame 49 of the controlled hot flap
shutter 40 during the manufacture thereof. On the contrary, it
represents a separate part and is machined to form an added metal
part. It is easy to envisage that, with attachment means, such as
assembly screws 41, corresponding nuts 42 and passage holes 43 in
the support part 47, 48 in the controlled hot flap shutter frame 49
and 38 in the flap shutter plate 32, the assembly can be attached
and disassembled independently from the manufacture of the
assembly.
[0030] Naturally, the geometry of the support part 47 and of the
friction surface 44 and the lateral flanks in particular must
correspond to those described above in the first embodiment. In
this second embodiment, the same advantages related to wear on the
friction surfaces 44, with respect to the nozzle seal and gasket at
the same point, are obtained.
* * * * *