The present invention relates to a device for guiding an element, such as a spark plug or a fuel injector, extending into an orifice or in the vicinity of an orifice of a chamber wall. turbomachine combustion.

An annular combustion chamber of a turbomachine is delimited by two coaxial walls of revolution which extend (relative to the axis 34 below) one inside the other and which are interconnected at their upstream ends by an annular chamber bottom wall.

The chamber bottom wall comprises orifices for mounting means for injecting a mixture of air and fuel inside the chamber, the air coming from a compressor of the turbomachine and the fuel being supplied by injectors.

The upstream is the side through which the mixture of air and fuel arrives in the annular combustion chamber.

[005] (With respect to axis 38 below), the injection means, or injectors, extend substantially radially from their outer ends fixed to an outer casing of the chamber, to their axially aligned heads with the holes in the back wall of the chamber.

The outer wall of revolution of the chamber comprises at least one orifice through which one end of a spark plug passes, the other end of which can be fixed to an outer casing of the chamber, this spark plug being intended for initiate combustion of the air and fuel mixture in the chamber.

[007] In operation of the turbomachine, the walls of the combustion chamber expand thermally, which generates relative movements between the outer wall of the chamber and the spark plug.

ignition and between the chamber bottom wall and the fuel injectors.

To compensate for and allow these relative movements, use is made of guiding devices for the spark plug and the injectors which each comprise a floating ring and a substantially coaxial flange mounted one inside the other. The ring is intended to be traversed axially by the element and comprises an outer rim guided transversely in an inner groove of the flange. The flange is intended to be attached to an edge of the orifice in the wall of the combustion chamber. This flange comprises a sleeve provided with a flanged edge where the sleeve is brazed or welded with a cup, so as to define said annular groove between them. The device has at least one preferred transverse direction of movement of the ring.

[009] The applicant's patent application EP-A1 -1 770 332 describes a guide device of this type. The relative movements between the outer wall of the chamber and the spark plug mainly take place in a direction parallel to the longitudinal axis of the chamber. In operation, the flange integral with the wall of the chamber is therefore essentially displaced in this longitudinal direction relative to the guide ring of the spark plug carried by the outer casing. The relative displacements of the ring in the groove of the flange in the other transverse directions are of smaller amplitudes. The axial or longitudinal direction is therefore the preferred direction of movement of the guide ring of the spark plug relative to the flange carried by the chamber.

[010] In the current technique, the two parts, cup and flange, forming the flange of a guide device are fixed to one another at their outer peripheries by one or more weld beads which extend over all around the socket.

[011] The expression solder covers both solders and actual solders.

[012] Although the operator in charge of making this weld takes maximum precautions to perform them, the weld beads can overflow into the annular guide groove of the ring and locally block the outer periphery of this groove, thus reducing or preventing the deflections of the ring in the transverse direction in the groove of the flange. The operation of welding the parts of the flange is therefore difficult to perform and does not make it possible to control these weld overflows. In addition, there is a risk of the device jamming and / or of deterioration of the welds, or even of rupture, each time the rim of the ring comes into contact with a weld bead which protrudes into the groove of the flange.

[013] The object of the invention is in particular to provide a simple, effective and economical solution to this problem.

[014] A device is therefore proposed for guiding an element in an orifice of a wall of a turbomachine combustion chamber, the device comprising a floating ring and a substantially coaxial flange mounted one inside the the other, the ring being intended to be traversed axially (so-called axis 520a) by an element and comprising an external rim guided transversely (to said axis 520a) in an internal annular groove of the flange, which is intended to be fixed to an edge of the orifice of the wall of the combustion chamber, the flange comprising a sleeve provided with a flanged edge where the sleeve is brazed or welded with a cup, so as to define, between them said groove, the device having at least a preferred transverse direction of displacement of the ring,this device being characterized in that, parallel to said axis (520a), between the welds or solders and the path of the edge of the ring when the latter is moved relative to the sleeve in the preferred direction, an intermediate space is reserved, as an extension of said groove.

[015] Thus, said welds or solders will overflow into this intermediate space; and the welds or solders will be outside of the path of the rim of the ring.

[016] The solution is simple to implement and economical. With the solution of the invention, said welds or solders can only overflow into said intermediate space, and therefore only into said space.

[017] One way to very effectively remove from said path the intermediate space, therefore the overflow of the welds or solders, will consist in providing that said space extends around a part of the cup, transversely to said axis (520a) , between said part of the cup and the flanged edge.

[018] The desired axial offset will be achieved around said part of the cup.

[019] An effective way to achieve this intermediate space, avoiding deforming the sleeve will consist in providing that the cup is stepped by means of a shoulder provided with an external rim through which the cup has been brazed or welded with an axially elongated end of the flanged edge.

[020] Thus, the shoulder will act as an obstacle or a screen between the zone of the path of the rim of the ring and the overflow zone.

[021] In addition, rather than conforming the cup with for example an inverted U-shaped peripheral shape, oriented parallel to said axis (520a), towards said groove, it may be preferred that, parallel to this axis, the height (H10 ci -after) of said flanged edge is at least equal to the height (H30 below) of said overflow increased by the thickness of the rim and by a clearance J (below) allowing the aforementioned rim to move in the inner groove of the flange.

[022] Thus, with respect to a known situation as in FIG. 2 presented below, the flanged edge will have "simply" been raised, along said axis (520a).

[023] And, if, transversely to said axis (520a), the rim moves away from the flanged edge the shoulder, as said part of the cup, thus creating said intermediate space reserved for the overflow of the welds or solders, it is possible to obtain , transversely to this axis 520a, the most appropriate compromise between the optimum volume for the overflow and the smallest bulk.

[024] Also concerned by the invention is a combustion chamber of a gas turbomachine for an aircraft, the combustion chamber extending annularly around an axis (34 below) and being provided with a guide device such as aforementioned, with all or part of the characteristics mentioned, this guide device defining a spark plug guide, the element guided in the orifice of said wall of the combustion chamber being a spark plug which communicates with an internal volume of the combustion chamber by this orifice, the wall in which said orifice is formed being an annular wall radially outer with respect to said axis (34).

[025] In particular, this combustion chamber may further comprise an annular chamber bottom wall connecting said radially outer annular wall to a radially inner annular wall relative to said axis (34), said chamber bottom annular wall comprising orifices for mounting systems for injecting an air and fuel mixture into the combustion chamber.

[026] Thus, an efficient combustion chamber can be proposed.

[027] If necessary, the invention will be better understood and other details, characteristics and advantages will appear on reading the following description given by way of non-limiting example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

- Figure 1 is a schematic half-view in axial section (axis 38 below) of a diffuser and a combustion chamber of an aeronautical turbomachine;

- Figure 2 is a schematic view, in axial section (axis 38 below), of a guide device according to the prior art;

- Figure 3 is a schematic view, in axial section (axis 38 below), of a guide device according to the invention;

- Figure 4 is an axial section (axis 38 below) of an annular cup that can be mounted on the solution of Figure 3.

DETAILED DESCRIPTION

[028] Reference is first made to FIG. 1 which represents an annular combustion chamber 10, for a turbomachine such as an airplane turbojet, arranged at the outlet of an annular diffuser 12, itself located at the outlet. a compressor (not shown). With reference to the axis 34 (see below), the chamber 10 comprises a wall of revolution, or annular, (radially) internal 14 and a wall of revolution, or annular, (radially) external 16 connected upstream (AM ) to an annular chamber bottom wall 18 and fixed downstream (AV) by radially internal 20 and external 22 annular flanges respectively on an internal frustoconical web 24 of the diffuser, and on a downstream end of an external casing 26 of the chamber, the upstream end of this casing 26 being fixed to an external frustoconical web 28 of the diffuser.

[029] The chamber bottom wall 18 comprises orifices 30 for mounting systems 37 for injecting an air and fuel mixture into the chamber 10, the air coming from the diffuser 12 and the fuel being supplied by injectors 32. The injectors 32 are fixed at their radially outer ends to the outer casing 26 and regularly distributed over a circumference around the axis of revolution 34 of the chamber. Each injector 32 comprises at its radially inner end a fuel injection head 36 which is guided in an injection system 37 and which is aligned with the axis 38 of one of the corresponding orifices 30 of the wall 18 of the chamber. , this axis 38 being coincident in the drawing with the longitudinal axis of the section of the chamber.

[030] The axes 34 and 38 are inclined relative to each other at an acute angle which diverges from upstream to downstream. It could be different.

[031] An annular cover 40 curved upstream is fixed to the upstream ends of the walls 14, 16 and 18 of the chamber and comprises air passage orifices 42 aligned with the orifices 30 of the bottom wall 18 of the chamber. bedroom. The mixture of air and fuel injected into chamber 10 is ignited by means of at least one spark plug 44 which extends radially outside the chamber. The spark plug 44 is guided at its radially inner end (therefore relative to the axis 34) in an orifice 460 in the outer wall 16 of the chamber, and its radially outer end is fixed by suitable means on the outer casing 26 and connected to electrical supply means (not shown) located outside the casing 26.

520a) radial, of the radially inner end (with respect to the axis 34 or 38) of the spark plug 44 is fixed outside the chamber 10 on the outer wall 16, around the orifice 46 (respectively 460) to compensate for the relative displacements between the outer wall 16 of the chamber and the spark plug 44 carried by the casing 26 during operation of the turbomachine. These relative displacements have

mainly takes place in the longitudinal direction, substantially parallel to the axis 38.

[032] A device 48 'for guiding the head 36 of the injector is also carried by each injection system 37 mounted in an orifice 30 in the wall 18 of the chamber, to compensate for the relative movements between the chamber and the 'injector which take place mainly in the radial direction with respect to the axis 38.

[033] FIG. 2 shows an embodiment in accordance with the prior art of / each aforementioned overall guide device, under the reference 48, as a solution prior to that of the guide device 480.

[034] The guide device 48 comprises a floating ring 50 traversed axially (axis 52a) by the spark plug 44 (or the head 36 of the injector) and mounted inside one end of a coaxial flange 52. The other end of the flange 52 is fixed by brazing, welding or the like on the outer wall 16 of the chamber, around an orifice 46 for the passage of the spark plug (or fixed on the injection system 37 carried by the wall. 18 of the bedroom). The ring 50 comprises a cylindrical part 54, the internal surface 56 of which surrounds the spark plug 44 (or the head 36 of the injector) with a slight clearance. This cylindrical part 54 is connected at one end to a frustoconical part 58 flared outwards which serves to guide the spark plug (or the head 36 of the injector) during its assembly in the device,

[035] The sleeve 64 comprises a cylindrical wall, or chimney, 68 which is welded or brazed at one end to the wall 16 (or to the injection system 37) and which is connected at its other end to a radial wall 70 to the axis 52a and defining an internal annular surface 72 (still relative to the axis 34) of the groove 62. The radial wall 70 of the sleeve 64 is connected at its outer periphery to a flange 74 extending from the side. opposite the cylindrical wall 68 and on which is applied and welded or brazed the periphery of the cup 66.

[036] The rim 74 can be radial with respect to the axis 38 and cylindrical. It is similar to a flanged edge, the height Hl ^ along the axis 52a, defines or at least influences the depth H2 of the groove 62, along the same axis. Here, hM = H2.

[037] The cup 66 extends substantially radially relative to the axis of the sleeve and defines another internal annular surface 76 of the groove 62, this surface 76 being parallel to the surface 72 defined by the first part 64 of the flange. The annular surfaces 72, 76 make it possible to guide the outer rim 60 of the ring in a radial or transverse plane with respect to the axis 52a of the flange. The external diameter of the annular rim 60 of the ring 50 is less than the internal diameter of the cylindrical rim 74 of the flange 52 and the external diameter of the cylindrical part 54 of the ring is less than the internal diameter of the cup 66 to allow movements of the rim 60 of the ring in the groove 62, in a transverse plane. In this solution, the cup 66 has the appearance of a flat washer.

[038] The invention makes it possible to remedy this problem by welding or brazing the cup and the sleeve in (at least) a space zone 881 - see FIG. 3 - which, radially (relative to the axis 34 / 38) or parallel to said axis 52a (marked 520a in figure 3)

is offset with respect to the preferred direction X1, X2 of displacement of the rim of the ring in the aforementioned groove, during operation of the combustion chamber; see FIG. 3: trajectory 600a of the rim 600 of the ring 500 when the latter is moved, in the groove 620, relative to the flange 520. Thus offset, the zone 881 is then away from this same direction X1, X2.

[039] In the preferred solution, and as illustrated in FIG. 3, it is under these conditions provided, parallel to the axis 520a, between the welds or solders 800 and the path 600a of the rim 600, that a said zone ( or space) 881 intermediate peripherally extends said groove 620, so that said welds or solders protrude there (at 780), so that these welds or solders are located outside said path 600a, regardless of the direction along the privileged direction X1, X2.

[040] The welds or solders 800 overflow (at 780) only in said intermediate zone (or space) 881, without therefore overflowing into, and therefore encroaching on, the groove 620, where the rim 600 moves along the trajectory 600a.

[041] In the preferred solution illustrated in FIG. 3, the same parts have been referenced identically, up to a multiplicative factor of 10, providing the same functions as those in FIG. 2.

[042] Their structural and functional differences are specified below.

[043] In the preferred embodiment and illustrated in Figures 3, 4, the flat cup 66 is replaced by a cup 660 stepped by means of a shoulder 661 provided with an outer flange 663 through which the cup 660 is soldered or welded with an axially elongated 741 end

(parallel to the axis 520a) of the wall or flange 740. The cup 66, annular, is therefore a kind of shouldered washer.

[044] The weld or solder overflows which penetrate into the groove 620 of the flange 520 and risk blocking it will therefore no longer limit the movements of the rim 600. It will therefore no longer be necessary to take these overflows into account in the dimensioning of the guide device flange 480.

[045] The intermediate space 881 which extends or extends over said groove 620 between said zone (s) 800 and the path 600a gives this groove a sort of peripheral curvature, thus creating an additional directory volume to that reserved for radial displacement to the axis 520a of the rim 600, where the solder or solder may overflow.

[046] In this preferred solution, rather than a complicated shape given to the cup 660 (with for example a peripheral rim oriented, parallel to the axis 520a, towards the wall 700), it was chosen here to create the space 881 by increasing the height of the wall 740. Parallel to the axis 520a, the height H10 of the wall 740 is equal to the height H30 of the overflow 780, increased by the thickness of the rim 600 and the clearance J allowing the ledge 600 to move into the groove 620.

[047] This increase in the height H10 of the wall 740 relative to that H1 of the wall 74 allows the brazing overflow not to be in the path 600a.

[048] In the preferred solution illustrated in FIG. 3, the space 881 extends around a part 665 of the cup 660, transversely to said axis 520a, between this part 665 and the wall 740 of the flange 520. The curvature peripheral is thus easily obtained.

[049] Said welding or brazing zone (s) 800 from which the overflows 780 originate can be formed by several weld spots or by one or more weld beads.

[050] Still in the preferred embodiment illustrated in FIG. 3, H10> H20. [051] This can be achieved simply, without having to deform the wall 740, simply by lengthening it, so that H10> JH, and by the shoulder 661 of the cup 660 extended by the outer rim 663 where the cup is therefore brazed or welded with the end 741 of the wall 740.

[052] Thus, the space 881 occupies the volume of the groove 620 located between the wall 740 and the part 665 of the cup 660, therefore facing the shoulder 661.

[053] We did not intervene on the chimney 680, nor on its fixing in 681 around the orifice 460.

[054] In a radial or transverse plane with respect to the axis 520a of the flange, the outer rim 600 of the ring is now guided between the annular inner surface 760 of the groove 620, located at the base of the shoulder 661 , and the internal surface 720 of the wall 700 of the flange 640. This wall 700, transverse to the axis 540a, connects the chimney 680 to the flanged edge 740.

[055] The internal surface 760 of the groove, this surface 76 being parallel The annular surfaces 72, 76 allow.

[056] It will also have been noted that with the rim 663, the preferred solution illustrated in FIG. 3 moves away from the wall or flanged edge 740, transversely to the axis 520a, the shoulder 661, as said part 663 of the cup. The space 881 is thus created.

CLAIMS

1. Device for guiding an element (44) in an orifice (460) of a wall of the combustion chamber (10) of a turbomachine, the device comprising a floating ring (500) and a substantially coaxial flange (520) mounted one inside the other, the ring (500) being intended to be traversed axially (520a) by an element and comprising an outer rim (600) guided transversely in an inner annular groove (620) of the flange (520), which is intended to be fixed to an edge of the orifice (460) of the wall of the combustion chamber (10), the flange (520) comprising a socket (640) provided with a flanged edge ( 740) where the sleeve is brazed or welded with a cup (660), so as to define between them said groove (620), the device having at least one transverse direction (X1,X2) favored displacement of the ring, characterized in that:

- parallel to said axis (520a), between the welds or solders (800) and the path (600a) of the edge of the ring (500) when the ring is moved relative to the sleeve in the preferred direction, a space (881) intermediate is reserved, as an extension of said groove (620),

- Said welds or solders protrude (780) into the intermediate space (881), so that the welds or solders (800) lie outside said path of the rim of the ring, and

- Said intermediate space (881) extends around a part (665) of the cup (660) transversely to said axis (520a), between said part (665) of the cup and the flanged edge (740).

2. Guide device according to claim 1 wherein, parallel to said axis (520a), the height (H10) of the flanged edge (740) is at least equal to the height (H30) of the overflow (780) increased by the thickness. the rim (600) and a clearance J allowing the rim (600) to move in the groove (620).

3. Guide device according to any one of the preceding claims, wherein the cup (660) is stepped by means of a shoulder (660) provided with an outer flange (663) by which the cup is brazed or welded with an axially elongated end (741) of the flanged edge (740).

4. Guide device according to claim 3 wherein, transversely to said axis (520a), the flange (663) away from the flanged edge (740) the shoulder (661), as said part (665) of the cup, and thereby created said space (881).

5. Combustion chamber (10) of a gas turbine engine for an aircraft, the combustion chamber extending annularly around an axis (34) and being provided with a guide device according to any one of the preceding claims, which defines a spark plug guide, the element guided in the orifice (460) of said wall (16) of the combustion chamber being a spark plug which communicates with an interior volume (11) of the combustion chamber (10) through said orifice (460), the wall (16) in which the orifice is formed being an annular wall radially outer with respect to said axis (34).

6. Combustion chamber (10) according to claim 5, which further comprises an annular chamber bottom wall (18) connecting said radially outer annular wall (16) to an annular wall (14) radially inner with respect to said axis ( 34), said annular chamber bottom wall (18) comprising orifices (30) for mounting systems (37) for injecting a mixture of air and fuel into the combustion chamber.