EP2609372A2

EP2609372A2 - Combustion chamber for an aircraft engine, and method for attaching an injection system in a combustion chamber of an aircraft engine

Info

Publication number: EP2609372A2
Application number: EP11755413.9A
Authority: EP
Inventors: Jacques Marcel Arthur Bunel; Brice Arnaud Demoulin; Mario César De Sousa; Guillaume Sevi
Original assignee: SNECMA SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 2010-08-27
Filing date: 2011-08-12
Publication date: 2013-07-03
Anticipated expiration: 2031-08-12
Also published as: WO2012025682A2; FR2964177A1; US20130152603A1; US9310083B2; FR2964177B1; WO2012025682A3; EP2609372B1

Abstract

The invention relates to a combustion chamber in which the injection system is attached so as to prevent any axial motion of said injection system. To this end, the combustion chamber includes: a baffle (4) comprising at least one tubular portion (6) having a first upstream end (9) surrounded by a first radially projecting collar (10); and an injection system comprising at least one bowl (7) which in turn comprises a cylindrical portion (8) inserted into the tubular portion (6), the cylindrical portion (8) comprising a second upstream end (11) surrounded by a second radially projecting collar, the second collar (12) axially bearing against the first collar (10), wherein the combustion chamber comprises clamping means which axially clamp the first and the second collars (10, 12) against one another, and attachment means which retain the clamping means clamped on either side of the first and second collars (10, 12).

Description

AIRCRAFT ENGINE COMBUSTION CHAMBER AND METHOD OF FIXING AN INJECTION SYSTEM IN A CHAMBER

COMBUSTION OF AIRCRAFT ENGINE

TECHNICAL FIELD The present invention relates to an aircraft engine combustion chamber in which is fixed an injection system. The present invention also relates to a method of fixing an injection system in an aircraft engine combustion chamber, and an aircraft engine comprising a combustion chamber according to the invention. STATE OF THE PRIOR ART

The combustion chambers of the turbojets generally comprise an inner wall and an outer wall connected at their upstream ends by an annular bottom so as to define a bottom of the combustion chamber. Injection systems regularly distributed over the periphery of the combustion chamber bottom deliver a mixture of air and fuel which is ignited to provide combustion gases. Each combustion system has a venturi in which air and fuel mix. Each injection system also comprises a bowl, located downstream of the venturi, whose function is to burst the jet of air / fuel mixture leaving the venturi. In addition, a deflector protects the chamber bottom of the flames of the combustion chamber.

FIG. 1 represents a system for fixing an injection system 1 in an aircraft engine combustion chamber of the prior art. The chamber bottom 2 of the combustion chamber is pierced by an orifice 3 in which a deflector 4 is inserted. The deflector 4 is brazed on the chamber bottom 2. The deflector 4 comprises a plate 5 from which a tubular part 6 projects. The tubular portion 6 is cylindrical and extends along a reference axis Y. The combustion system 1 comprises a swirler 19 on which is mounted a sliding bushing 20 adapted to slide radially with respect to the swirler 19. The sliding bushing 20 comprises a centering cone 21 in which an injector nose (not shown) will be inserted. The injection system also comprises a bowl 7 integral with the twist 19. The bowl 7 comprises a cylindrical portion 8 which has a symmetry of revolution about the reference axis Y. The cylindrical portion 8 of the bowl is inserted into the tubular portion 6 of the baffle. The tubular portion 6 of the baffle further comprises an upstream end 9 which is surrounded by a first collar 10 projecting radially. The cylindrical portion 8 of the bowl also has an upstream end 1 1 which leaves the upstream end 9 of the tubular portion 6. The upstream end 1 1 of the cylindrical portion is surrounded by a second collar 12 projecting radially. The second collar 12 bears axially on the first flange 10. The injection system is fixed to the deflector 4 by two half-rings 13 which are inserted radially into an annular groove 35 located downstream of the first flange. The two half-rings 13 are further arranged so that they surround the first and second flanges. Each half-ring 13 comprises a first retaining flange 14 which is inserted under the first flange 10 and a second retaining flange 15 which is inserted above the second collar 12, so that the two collars 10 and 12 are trapped axially between the two retaining flanges 14 and 15, and radially by the side walls 16 of the two half-rings 13.

A cylindrical retaining ring 17 is then inserted around the two half-rings 13 so as to prevent the two half-rings 13 from deviating radially from one another. Seams 18 join the retaining ring 17 to the two half-rings 13.

FIG. 2 represents an enlarged view of the two flanges 10 and 12, surrounded by the half-rings 13, which themselves are capped by the retaining ring 17. This system for fixing the injection system 1 to the combustion chamber is easy to implement. However, the Applicant has found that with such a fastening system, the nose of the fuel injector which is inserted into the injection system has a high wear and a reduced service life.

Similarly, the documents EP1873454, EP1731839, EP1873458 have combustion chambers in which the nose of the injector has a reduced life and significant wear. SUMMARY OF THE INVENTION

The invention aims to remedy, at least partially, the disadvantages of the state of the art by providing a combustion chamber more resistant to wear and which has an improved life. To do this, the invention proposes to use a fastening system of the first and second flanges that prevent any deflection of the injection system relative to the baffle. Indeed, the applicant has found that vibratory activity at the first and second flanges, which are struggling between the two retaining rims of the half-rings 13, amplifies the phenomenon of wear on the fuel injector and thus reduces the service life of the firebox.

More specifically, a first aspect of the invention relates to an aircraft engine combustion chamber comprising at least: a deflector comprising at least one tubular part, the tubular part extending along a reference axis, the tubular part having a first upstream end surrounded by a first radially projecting collar; an injection system comprising at least one bowl itself having a cylindrical part inserted in the tubular part, the cylindrical part comprising a second upstream end emerging from the first upstream end of the tubular part, the second upstream end of the cylindrical part being surrounded by a second collar projecting radially, the second collar being in axial abutment against the first flange; the combustion chamber further comprising: clamping means which axially clamp the first and second collars against each other, and fastening means which hold the tightening means tight on either side of the first and the second flanges. Thus, in the combustion chamber according to the invention, the injection system is fixed to the deflector by means of clamping means which prohibit any axial movement of the second collar relative to the first collar, so that the system of injection can not vibrate relative to the chamber floor. Thus, the nose wear of the injector, which is inserted into the injection system, is reduced. The combustion chamber according to the invention may also have one or more of the characteristics below, considered individually or in any technically possible combination.

According to one embodiment, the clamping means comprise two jaws, one of the jaws bearing axially against the first flange, the other of the jaws bearing axially against the second flange, the two jaws clamping axially between them the two flanges. , the fixing means now the two jaws tight on both sides of the two flanges.

Advantageously, the two jaws extend circumferentially around the two flanges. According to a preferred embodiment, the clamping means comprise:

A retaining ring divided into at least two ring portions, the retaining ring comprising at least: a retaining ring bearing axially against the first flange, and a peripheral retaining protruding skirt of the retaining ring , the peripheral retaining skirt radially surrounding the first and the second flanges,

A retaining ring comprising at least: a retaining ring bearing axially against the second flange, and a retaining peripheral skirt protruding axially from the retaining ring, the peripheral retaining skirt radially surrounding the peripheral retaining skirt ; the fastening means solidarisant the retaining ring and the retaining ring so that the retaining ring and the retaining ring maintain tightly axially between them the first and the second flanges.

Thus, according to a preferred embodiment, the retaining ring is separated into a plurality of ring portions, so that it can be inserted downstream of the first collar. Indeed, if the retaining ring was formed in one piece, it could not be mounted downstream of the first flange.

In this document, the terms "downstream" and "upstream" relate to the direction of flow of the combustion gases inside the cylindrical portion.

The peripheral retaining ring of the retaining ring, which is located upstream of the first and second flanges, is in one piece and serves to hold the ring portions which constitute the retaining ring together. .

The peripheral retaining skirt and the peripheral retaining skirt therefore make it possible to limit the movements of the first and second flanges radially. The retaining ring is positioned in axial abutment against the second flange and the retaining ring is positioned in axial abutment against the first flange, so that the first and second collars are axially clamped between these two rings. These two rings thus prohibit any axial displacement of the second collar relative to the first flange. Advantageously, the ring portions that constitute the retaining ring are two half-rings, so that the retaining ring is divided into two half-rings. Each element of the retaining ring is also divided into as many portions as the retaining ring. Thus, when the retaining ring is split into two portions, the retaining ring is also split into two portions, as the peripheral retaining skirt.

Advantageously, the tubular portion is cylindrical.

Advantageously, the tubular portion furthermore has a lateral wall, a shoulder projecting radially from this lateral wall, an annular groove being defined between the first flange and the shoulder, the retaining ring being inserted into the annular groove.

The side wall extends parallel to the reference axis.

Advantageously, the annular groove is delimited transversely by the first flange, which projects radially from the side wall, and by a shoulder of the side wall. The first flange thus forms the upstream wall of the annular groove, while the shoulder of the side wall forms the downstream wall of the annular groove. The retaining ring, which is inserted into the annular groove, bears axially against the first flange.

Advantageously, the fastening means comprise: at least two fastening tabs secured to the holding ring, said fastening tabs defining with the peripheral holding skirt a peripheral groove in which the peripheral retaining skirt is inserted, at least a weld which secures each latching lug to the retaining ring. According to different embodiments:

the weld can be discontinuous, so that the weld points secure each fastening tab to the retaining ring or

- The weld can be continuous, so that a weld bead secures each latching lug to the retaining ring. According to different embodiments:

the first and the second flanges come in radial abutment against the peripheral retaining skirt; in this case, the two flanges are immobilized radially;

- There is a game between the first and second flanges on the one hand and the peripheral retaining skirt on the other. This game facilitates editing. Advantageously, the peripheral retaining skirt has a height h1 less than the height h2 of the assembly formed by the first flange and the second flange. Thus, when the retaining ring and the retaining ring are placed on either side of the two flanges, they can be pressed against the two flanges, without the retaining peripheral skirt being blocked by the retaining ring.

More generally, the retaining ring and the retaining ring are shaped so as to be nested one inside the other, while each being in axial support against one of the collars.

A second aspect of the invention relates to an aircraft engine which comprises a combustion chamber according to the first aspect of the invention.

A third aspect of the invention relates to a method of fixing an injection system in an aircraft engine combustion chamber, the combustion chamber comprising a deflector comprising at least one tubular part, the tubular part extending along a reference axis, the tubular portion having a first upstream end surrounded by a first radially projecting flange, the injection system comprising at least one bowl itself having a cylindrical portion inserted into the tubular portion, the cylindrical portion comprising a second upstream end emerging from the first upstream end of the tubular portion, the second upstream end of the cylindrical portion being surrounded by a second radially projecting collar, the second collar being in axial abutment against the first collar, the fixing method comprising the following steps:

(a) There are clamping means on either side of the first and second flanges so that these clamping means axially clamp the first and second collars against each other; and

(b) The clamping means are fixed on either side of the first and second collars so as to keep the clamping means clamped axially on either side of the first and second collars.

Advantageously, step (a) breaks down as follows: Several ring portions are inserted downstream of the first flange, the ring portions forming a retaining ring, the retaining ring including at least one holding ring and a peripheral protruding protruding skirt of the retaining ring, the ring portions being positioned so that the first flange is in axial abutment against the retaining ring and the retaining peripheral skirt radially surrounds the first and the second flanges,

A retaining ring is placed in axial abutment against the second flange, the retaining ring comprising a retaining ring bearing axially against the second collar, the retaining ring comprising a peripheral retaining skirt projecting axially from the ring. retainer, the peripheral retaining skirt radially surrounding the peripheral retaining skirt,

The first and second collars are clamped axially between the ring portions on the one hand and the retaining ring on the other hand.

Advantageously, each ring portion comprises at least one latching lug, each latching lug defining with the peripheral retaining skirt a peripheral groove in which is inserted the peripheral retaining skirt.

Advantageously, step (b) is a step of welding each latching lug to the retaining ring.

BRIEF DESCRIPTION OF THE FIGURES

Other characteristics and advantages of the invention will emerge on reading the detailed description which follows, with reference to the appended figures, which illustrate:

- Figure 1, a sectional view of an injection system fixed in a combustion chamber of the prior art,

- Figure 2, an enlarged sectional view of the attachment of the injection system of Figure 1 to the combustion chamber; - Figure 3, a sectional view of a combustion chamber according to one embodiment of the invention;

- Figure 4, a sectional view of an injection system fixed in the combustion chamber of Figure 3;

- Figure 5, an enlarged sectional view of the attachment of the injection system of Figure 4 to the combustion chamber of Figure 3;

- Figure 6, a sectional view of an injection system according to another embodiment of the invention;

FIGS. 7a to 7c, perspective views of the various steps of a fixing method according to one embodiment of the invention;

- Figures 8, other fixing and clamping means that can be used in the combustion chamber according to the invention.

For the sake of clarity, identical or similar elements are identified by identical reference signs throughout the figures.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT FIGS. 3 to 5 show a combustion chamber according to one embodiment of the invention. This combustion chamber has a form of longitudinal symmetry of revolution relative to a general axis of a turbine. The combustion chamber has an inner housing wall 22 and an outer housing wall 23. An inner chamber wall 24 defines a passage 25 with the inner housing wall 22. An outer chamber wall 26 defines a passage 27 with the wall outer casing 23.

The inner and outer chamber walls 24 and 26 are joined by a chamber bottom 2 at their upstream ends. A plurality of injection systems 1, typically fourteen to twenty-two, regularly spaced angularly (only one injection system has been shown in FIG. 3) are provided on the chamber bottom 2.

As can be seen in more detail in FIG. 4, each injection system comprises in particular a bowl 7 secured to a swirler 19 which are fixed and a sliding bushing 20 which is able to move in a cavity 28 of the tendrill 19. The Sliding bushing 20 comprises a centering cone 21 into which a fuel injector 29 (shown in FIG. 3) is inserted.

The deflector 4 comprises a plate 5 and a tubular portion 6. The tubular portion 6 has a symmetry of revolution about a reference axis Y, and more specifically it has a cylindrical shape around the reference axis Y. The plateau 5 serves to protect the chamber bottom 2 of the flames of the combustion chamber. The tubular portion 6 is inserted into an orifice 3 of the chamber bottom 2. The tubular portion 6 comprises a shoulder 30 which bears axially against a downstream wall 31 of the chamber bottom. The deflector 4 is brazed on the chamber bottom 2. The tubular portion 6 has a side wall 33 which extends along the reference axis Y. The side wall 33 is cylindrical about the reference axis Y. The part tubular 6 has a first upstream end 9 which is surrounded by a first flange 10 projecting radially from the side wall 33 of the tubular portion 6. The tubular portion 6 also has a shoulder 34 projecting radially from the side wall 33. The first flange 10 and the shoulder 34 define between them an annular groove 35 which has a symmetry of revolution about the reference axis Y.

The bowl 7 comprises a cylindrical portion 8 which has a symmetry of revolution with respect to the reference axis Y. The cylindrical portion 8 also comprises a side wall 36 which extends along the reference axis Y. The cylindrical portion 8 has a second upstream end 1 1 which is surrounded by a second flange 12 projecting radially from the side wall 36 of the cylindrical portion 7. The cylindrical portion 8 is inserted into the tubular portion 6 so that the second upstream end 1 1 of the cylindrical portion 7 opens out of the first upstream end 9 of the tubular portion 6. The second collar 12 is axially supported on the first collar 10.

The fastening system according to an embodiment of the invention of the injection system to the baffle will now be described in more detail with reference to FIGS. 4 and 5. The fastening system according to the invention comprises clamping means. According to one embodiment, these clamping means comprise a retaining ring 37 and a retaining ring 38.

The retaining ring 37 comprises a retaining ring 39 which extends transversely with respect to the reference axis Y. The retaining ring 39 has a symmetry of revolution with respect to the reference axis Y. The ring 39 is inserted radially into the annular groove 35 and bears axially against the first collar 10.

The retaining ring 37 also comprises a peripheral retaining skirt 40 which is integral with the retaining ring 39. The retaining peripheral skirt 40 is disposed on the peripheral of the retaining ring 39 and is projecting axially from the retaining ring 39. 39. The retaining peripheral skirt 40 has a cylindrical geometry around the reference axis Y.

The retaining ring 37 is divided into several portions, which are here two half-rings to allow its insertion into the annular groove 35. However, it could also be envisaged to split the retaining ring 37 in more than two portions, without leaving the framework of the invention.

The retaining ring 37 further comprises at least two attachment tabs 41, each ring portion comprising at least one of the attachment tabs 41. According to a preferred embodiment, the retaining ring comprises four latching lugs 41 distributed over the periphery of the retaining ring 37. Each latching lug 41 is connected to the peripheral retaining skirt 40. The latching lugs 41 define with the peripheral retaining skirt 40 a peripheral groove 42. The peripheral groove 42 extends around the reference axis Y. The retaining ring 38 has a retaining ring 43 which bears axially against the second flange 12 and a peripheral retaining skirt 44 projecting axially from the second flange 12. The peripheral retaining skirt 44 is disposed on the periphery of the retaining ring 43.

The retaining ring 37 and the retaining ring 38 are shaped so as to be able to fit into each other when the retaining ring 37 is axially supported. against the first flange 10 and that the retaining ring 38 being in axial abutment against the second flange 12.

For this, the peripheral retaining skirt 40 has a height h1 less than the height h2 of the assembly formed by the first flange and the second flange in abutment against each other. In addition, the peripheral retaining skirt 44 has a height h3 less than the height h4 of the peripheral groove 42.

The fastening system according to the invention also comprises fixing means.

In this embodiment, the fastening means comprise beads or soldering points 45 which secure each fastening tab 41 to the retaining ring 38 so that the retaining ring 37 and the retaining ring 38 tighten. axially, between them, the first and the second flanges 10 and 12. Advantageously, the fastening means comprise four welding points.

Each latching lug has an upstream surface 55. The retaining ring 43 has an upstream surface 54. In order to facilitate the welding of each latching lug to the retaining ring, the latching lugs 41 and the locking ring retainers are dimensioned so that, when the retaining ring 39 is pressed against the first collar 10 and the retaining ring 43 is pressed against the second flange 12, the upstream surface 55 of each latching lug 41 is aligned axially with the upstream surface 54 of the retaining ring 43.

In addition, each attachment lug 41 has a chamfer 57 at the intersection between its upstream surface 55 and a second lateral surface 58 of the peripheral groove 42. This chamfer 57 is preferably bevelled.

Similarly, the retaining ring 38 has a chamfer 56 between its upstream surface 54 and the outer surface 59 of the peripheral retaining skirt 44. This chamfer 56 is also preferably bevelled, so that when the peripheral skirt of retained 44 is inserted into the peripheral groove 42, the chamfers 56 and 57 form between them an annular groove 60. The weld bead 45 is preferably deposited in this annular groove 60. In addition, the peripheral retaining skirt 40 preferably has a radial dimension adjusted relative to the radial dimension of the annular groove 42, so that the peripheral retaining skirt 40 can penetrate into the peripheral groove and, when the skirt retaining device 40 is inserted into the annular groove, it can not, or almost no longer, move radially. Thus, according to the invention, the first flange 10 and the second collar 12 are pressed axially against each other. There is no axial play between the retaining ring 37, the retaining ring 38 and the two flanges 10 and 12, so that the injection system 1 is immobilized axially with respect to the deflector 4.

The invention thus makes it possible to limit the wear of the nose of the injector. In order to further limit the wear of the nose of the injector, the invention described in this document is preferably combined with means for axially immobilizing the sliding passage relative to the twist 19.

For this purpose, FIG. 6 represents a preferred embodiment in which the injection system 1 is fixed to the deflector 4 as described previously with reference to FIGS. 3 to 5. In addition, the injection system 1 comprises means immobilization for axially immobilizing the sliding bushing 20 in the cavity 28 of the swirler 19, while allowing radial adjustments of the position of the sliding bushing 21 in the cavity.

For this, the sliding bushing 20 comprises a sole 46 contained in a cavity 28 of the auger. This cavity 28 is delimited by a bottom 47, a closing cup 48 and a side wall 49. The sole 46 is in axial abutment against the bottom 47 of the cavity 28. The immobilizing means preferably comprise a washer 50 in support axial axis on the sole 46 and spring means 51 which are constrained axially between the washer 50 and the closing cup 48. These spring means 51 exert on the sole 46 a sufficient force to prevent any vibration of the sliding bushing in the cavity 28, while allowing the radial movements of the sliding bushing to tolerate differential expansions.

Advantageously, these spring means 51 comprise an annular corrugated plate of metal. These immobilization means are described more specifically in the document FR No. 1056125.

A method of fixing the injection system in the combustion chamber described with reference to Figures 3 to 5 will now be described with reference to Figures 7a to 7c. FIG. 7a shows in perspective a chamber bottom 2, on which a deflector 4 is brazed. The deflector 4 comprises a plate 5 and a tubular part 6. A bowl 7 comprises a cylindrical part 8. The cylindrical part 8 is inserted in the tubular portion 6 as explained with reference to Figures 3 to 5.

In a first step, represented in FIG. 7b, the portions of rings that constitute the retaining ring, and which are here half-rings 52, are placed downstream of the first collar, and more precisely in the annular groove. 35 of the tubular portion 6 of the deflector. At the end of this step, the retaining ring 39 is inserted into the annular groove 35 and the holding peripheral skirt 40 surrounds the first and the second flanges 10 and 12. In a second step, shown in FIG. 7c, the retaining ring 38 is placed around the two half-rings 52 so that the retaining ring 43 is in axial abutment against the second flange 12 and the peripheral retaining skirt 44 is inserted into the peripheral groove 42 formed by the peripheral retaining skirt 40 and the attachment tabs 41. In a third step, the two half-rings 52 and the retaining ring 38 are clamped axially, for example with the aid of a clamp or pincer, so as to axially flatten them on both sides. other of the assembly formed by the first and the second flanges 10 and 12.

In a fourth step, the attachment lugs 41 are welded to the retaining ring 38. The two half-rings 52 and the retaining ring 38 are then secured around the first flange and the second flange in a position such that the two collars are immobilized axially between the two half-rings 52 and the retaining ring 38. Naturally, the invention is not limited to the embodiments described with reference to the figures and variants could be envisaged without departing from the scope of the invention. In particular, the geometry of the combustion chamber could vary, just like the elements forming the injection system. In addition, the clamping and fixing means could take other forms. By way of example, FIG. 8 shows, in section, other means of clamping and fixing the first and second flanges 10 and 12. These clamping means also comprise a retaining ring 37 'and a ring retainer 38 '.

The retaining ring 37 'is split into several ring portions as in the embodiment described with reference to Figures 3 to 5. The retaining ring 37' has a retaining ring 39 'which extends radially. The retaining ring 37 'has an inner retaining skirt 40' which protrudes axially from the retaining ring 39 '. The retaining ring 37 'further comprises an outer retaining skirt 53 which also protrudes axially from the retaining ring 39'. The inner support skirt 40 'and the outer support skirt 53 define between them a peripheral groove 42' which extends over the circumference of the retaining ring 37 '.

The retaining ring 38 'has a retaining ring 43' and a retaining peripheral skirt 44 '. The peripheral retaining skirt 44 'and the peripheral groove 42' are sized so that the peripheral retaining skirt 44 'can be inserted into the peripheral groove 42' without interfering with the axial support of the retaining ring 39 'on the second flange 12 and the axial support of the retaining ring 43 'on the first flange 10. Similarly, the inner retaining skirt is dimensioned to be able to surround the two flanges 10 and 12 without interfering with the axial support of the flange retaining ring 39 'on the second flange 12 and the axial support of the retaining ring 43' on the first flange 10.

The retaining ring 37 'and the retaining ring 38' axially clamp the two flanges together and prevent them from moving axially. The retaining ring 37 'and the retaining ring 38' are secured in this position by a weld bead 45 'which can be continuous or discontinuous. The outer support skirt 53 has an upstream end which is substantially aligned with the retaining ring 43 'so as to facilitate the welding of these two elements.

Claims

1. Aircraft engine combustion chamber comprising at least:

a deflector (4) comprising at least one tubular part (6), the tubular part (6) extending along a reference axis (Y), the tubular part (6) having a first upstream end (9) surrounded by a first flange (10) projecting radially;

an injection system comprising at least one bowl (7) itself comprising a cylindrical part (8) inserted in the tubular part (6), the cylindrical part (8) comprising a second upstream end (1 1) opening out of the first upstream end (9) of the tubular part (6), the second upstream end (1 1) of the cylindrical part (8) being surrounded by a second flange (12) projecting radially, the second flange (12) being in axial support against the first flange (10); the combustion chamber being characterized in that it further comprises:

- clamping means which axially clamp the first and second flanges (10, 12) against each other, and

- Fastening means which maintain the tightening means tight on both sides of the first and second flanges (10, 12).

2. Combustion chamber according to the preceding claim, characterized in that the clamping means comprise:

- A retaining ring (37) split into at least two ring portions (52), the retaining ring (37) comprising at least:

a holding ring (39) bearing axially against the first flange (10), and o a peripheral retaining skirt (40) projecting axially from the retaining ring (39), the peripheral retaining skirt (40) radially surrounding the first and the second flanges (10, 12),

- A retaining ring (38) comprising at least:

a retaining ring (43) bearing axially against the second flange (12), and

o A peripheral retaining skirt (44) projecting axially from the retaining ring (43), the peripheral retaining skirt (44) radially surrounding the peripheral retaining skirt (40); the fixing means solidarisant the retaining ring (37) and the retaining ring (38) so that the retaining ring (39) and the retaining ring (43) keep axially tightly between them the first and the second flanges (10, 12).

3. Combustion chamber according to the preceding claim, characterized in that the tubular portion (6) further has a side wall (33), a shoulder (34) radially projecting from said side wall (33), an annular groove ( 35) being defined between the first flange (10) and the shoulder (34), the retaining ring (39) being inserted into the annular groove (35).

4. Combustion chamber according to any one of claims 2 or 3, characterized in that the fixing means comprise:

at least two clawing lugs (41) integral with the retaining ring (37), said latching lugs (41) defining with the peripheral retaining skirt (40) a peripheral groove (42) in which is inserted the peripheral retaining skirt (44),

- At least one weld (45) which secures each latching lug (41) to the retaining ring (38).

5. Combustion chamber according to any one of claims 2 to 4, characterized in that the first and the second flanges (10, 12) abut in radial abutment against the peripheral retaining skirt (40).

6. Combustion chamber according to any one of claims 2 to 5, characterized in that the peripheral retaining skirt (40) has a height h1 less than the height h2 of the assembly formed by the first flange (10) and the second flange (12).

7. Aircraft engine comprising at least one combustion chamber according to any one of the preceding claims.

8. Method for fixing an injection system (1) in an aircraft engine combustion chamber, the combustion chamber comprising a deflector (4) comprising at least one tubular part (6), the tubular part ( 6) extending along a reference axis (Y), the tubular portion (6) having a first upstream end (9) surrounded by a first radially projecting collar (10), the injection system (1) comprising at least one at least one bowl (7) having itself a cylindrical part (8) inserted into the tubular part (6), the cylindrical part (8) comprising a second upstream end (1 1) emerging from the first upstream end (9) of the tubular part (6), the second upstream end (1 1) of the cylindrical part (8) being surrounded by a second flange (12) radially projecting, the second flange (12) bearing axially against the first flange ( 10), the fixing method comprising the following steps es:

(a) There are clamping means on either side of the first and second collars (10, 12) so that these clamping means axially clamp the first and second collars (10, 12). ) one against the other ; and

(b) The clamping means are fixed on either side of the first and second flanges (10, 12) so as to keep the tightening means clamped axially on either side of the first and second flanges. the second flanges (10, 12).

9. Method according to the preceding claim, characterized in that step (a) is broken down as follows: - Several ring portions (52) are inserted downstream of the first flange (10), the ring portions forming a retaining ring (37), the retaining ring (37) having at least one retaining ring (39) and a circumferential retaining peripheral skirt (40) of the retaining ring (39), the ring portions being positioned so that the first flange (10) bears axially against the retaining ring ( 39) and that the peripheral retaining skirt (40) radially surrounds the first and the second flanges (10, 12),

- A retaining ring (43) is placed in abutment against the second flange (12), the retaining ring (38) comprising a retaining ring (43) bearing axially against the second flange (12), the ring retainer (38) having a peripheral retaining skirt (44) projecting axially from the retaining ring (43), the peripheral retaining skirt (44) radially surrounding the peripheral retaining skirt (40),

- The first and the second flanges (10, 12) are clamped axially between the ring portions (52) on the one hand and the retaining ring (38) on the other hand.

10. Method according to the preceding claim, wherein the ring portions (52) further comprise at least one latching lug (41) each, said latching lugs defining with the peripheral retaining skirt a peripheral groove in which is inserted the peripheral retaining skirt, characterized in that step (b) is a step of welding the latches to the retaining ring.