Annular turbomachine combustion chamber

Abstract

An annular combustion chamber (10) for a turbomachine (100), the combustion chamber presenting an axial direction (X), a radial direction, and an azimuth direction, and comprising a first annular wall (12) and a second annular wall (14), each wall delimiting at least a portion of the volume of the annular combustion chamber (10), the first and second walls (12, 14) presenting complementary fitting elements (12d, 14d), the first wall (12) presenting at least one first through hole (12f), while the second wall (14) presents at least one second through hole (14f), the combustion chamber (10) also having at least one pin (18) engaged in a pair of holes comprising a first hole (12f) and a second hole (14f), said pin (18) locking the fitting of the first and second walls (12, 14).

Claims

1. An annular combustion chamber for a turbomachine including an axial direction, a radial direction, and an azimuth direction, the annular combustion chamber comprising a first annular wall and a second annular wall, each of the first annular wall and the second annular wall delimiting at least a portion of a volume of the annular combustion chamber, the first annular wall and the second annular wall including complementary fitting elements, the first annular wall including at least one first through hole, while the second annular wall includes at least one second through hole, the annular combustion chamber also having at least one pin engaged in a pair of through holes comprising one first through hole and one second through hole, said at least one pin locking a fitting together of the first annular wall and the second annular wall, said at least one pin being formed by an injector; wherein one of the one first through hole or the one second through hole of the pair of through holes is provided in a projecting blade; and wherein a projection arranged at the other of the one first through hole or the one second through hole of the pair of through holes extends substantially parallel to an axis of said other of the one first through hole or the one second through hole so as to co-operate with the projecting blade by snap-fitting.

2. The annular combustion chamber according to claim 1, wherein the one first through hole and the one second through hole of the pair of through holes are disposed substantially facing each other.

3. The annular combustion chamber according to claim 1, wherein the at least one pin extends substantially radially.

4. The annular combustion chamber according to claim 1, wherein the complementary fitting elements comprise a plurality of axial tongues extending in the axial direction from one of the first annular wall and the second annular wall, and a plurality of openings provided in the other of the first annular wall and the second annular wall, said plurality of openings receiving the plurality of axial tongues.

5. The annular combustion chamber according to claim 1, wherein one of the first annular wall and the second annular wall includes an annular shoulder that co-operates axially in abutment with the other of the first annular wall and the second annular wall.

6. The annular combustion chamber according to claim 1, having only two annular walls delimiting the volume of the combustion chamber, wherein the two annular walls are the first annular wall and the second annular wall.

7. A turbomachine including the annular combustion chamber according to claim 1.

8. An annular combustion chamber for a turbomachine including an axial direction, a radial direction, and an azimuth direction, the annular combustion chamber comprising a first annular wall and a second annular wall, each of the first annular wall and the second annular wall delimiting at least a portion of a volume of the annular combustion chamber, the first annular wall and second annular wall including complementary fitting elements, the first annular wall including at least one first through hole, while the second annular wall includes at least one second through hole, wherein both the at least one first through hole and the at least one second through hole face a radial center of the annular combustion chamber, the annular combustion chamber also having at least one pin engaged in a pair of through holes comprising one first through hole and one-second through hole, said at least one pin locking a fitting together of the first annular wall and second annular wall, said at least one pin being formed by an injector; wherein one of the one first through hole or the one second through hole of the pair of through holes is provided in a projecting blade; and wherein a projection arranged at the other of the one first through hole or the one second through hole of the pair of through holes extends substantially parallel to an axis of said other of the one first through hole or the one second through hole so as to co-operate with the projecting blade by snap-fitting.

9. The annular combustion chamber of claim 8, wherein the first annular wall includes a plurality of first through holes spaced about a circumference of the first annular wall, and the second annular wall includes a plurality of second through holes spaced about a circumference of the second annular wall, and the annular combustion chamber includes a plurality of injectors spaced about a circumference of the annular combustion chamber, each injector of the plurality of injectors extending through a respective pair of through holes comprising a first through hole and a second through hole, wherein each pair of through holes containing a respective injector of the plurality of injectors faces the radial center of the annular combustion chamber.

10. The annular combustion chamber of claim 9, wherein the complementary fitting elements comprise a plurality of axial tongues extending in the axial direction from one of the first annular wall and the second annular wall, and a plurality of openings provided in the other of the first annular wall and the second annular wall, said plurality of openings receiving the plurality of axial tongues.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages can be better understood on reading the following detailed description of various embodiments of the invention given as non-limiting examples. The description refers to the accompanying sheets of figures, in which:

(2) FIG. 1 shows a turbomachine having a combustion chamber;

(3) FIG. 2 shows the annular walls of the FIG. 1 combustion chamber seen in perspective;

(4) FIG. 3 is a detail view of the annular walls of FIG. 1; and

(5) FIG. 4 shows the annular walls of FIG. 1 when assembled together.

DETAILED DESCRIPTION OF EMBODIMENTS

(6) FIG. 1 shows a turbomachine 100 having an annular combustion chamber 10, while FIGS. 2 to 4 show the two annular walls 12 and 14 of the combustion chamber 10 in greater detail. It should be observed that the combustion chamber 10 is an annular chamber of the reverse flow type, but that the invention is not limited to this particular type of combustion chamber.

(7) The combustion chamber 10 presents an axial direction (along the axis X), a radial direction R, and an azimuth direction Y. The combustion chamber 10 presents symmetry of revolution about the axis X. In this example, the first wall 12 forms a flame tube delimiting the volume in which the fuel ignites, i.e. where combustion takes place. The second wall 14 forms an outer bend and serves as a deflector for guiding the flow of gas coming from the flame tube. This combustion chamber example 10 has only two annular walls 12 and 14 for delimiting the volume 10a of the combustion chamber 10.

(8) More particularly, each of the first wall 12 and the second wall 14 presents a general shape that is substantially half a torus, the torus being split perpendicularly to its axis of revolution, like a donut mold, the two half-toruses being placed facing each other. Thus, each wall 12 and 14 has an outer portion 12a, 14a that is substantially axial, an inner portion 12b, 14b that is substantially axial, and a bottom 12c, 14c that is substantially radial interconnecting the outer and inner portions 12a and 12b of the first wall 12, or the outer and inner portions 14a and 14b of the second wall 14. It should be recalled that in general, and unless specified to the contrary, the adjectives inner and outer are used with reference to a radial direction such that an inner portion (i.e. a radially inner portion) of an element is closer to the axis X than is an outer portion (i.e. radially outer portion) of the same element.

(9) In this example, the radius of the outer portion 12a of the first wall 12 is substantially equal to, but less than, the radius of the outer portion 14a of the second wall 14, while the radius of the inner portion 12b of the first wall 12 is greater than the radius 14b of the second wall 14. It is thus possible to assemble the first wall 12 with the second wall 14 via their outer walls 12a and 14a, the outer portion 12a of the first wall 12 being arranged inside the outer portion 14a of the second wall 14, while the difference in radius of the inner portions 12b and 14b serves to create an exhaust duct for the combustion gas.

(10) The first wall 12 presents a plurality of axial tongues 12d, while the second wall 14 presents a plurality of openings 14d configured to receive the tongues 12d of the first wall 12. The tongues 12d and the openings 14d in this example form complementary axial fitting elements of the first and second walls 12 and 14. Naturally, in a variant that is not shown, tongues could form complementary elements for fitting in azimuth, or for fitting both axially and in azimuth.

(11) The axial tongues 12d extend axially from the outer portion 12a of the first wall 12. The openings 14d are arranged in an annular shoulder 14e that extends radially and that connects the outer portion 14a to the bottom 14c of the second wall 14. In this example, there are as many tongues 12d as there are openings 14d, each opening 14d receiving one tongue 12d.

(12) When the first wall 12 is fitted axially with the second wall 14, the tongues 12d are caused to penetrate into the openings 14d, while the free axial end of the outer portion 12a of the first wall co-operates with the shoulder 14e by coming axially into abutment therewith.

(13) The first wall 12 presents a plurality of first through holes 12f, with the axes of these holes 12f extending radially. These holes 12f are arranged in the outer portion 12a of the wall 12. The second wall 14 presents second through holes 14f with axes that extend radially. The holes 14f are arranged in blades 14g that project axially from the outer portion 14a of the second wall 14. In this example, the holes 12f and 14f are substantially circular, however they could naturally present some other shape. When the first and second walls 12 and 14 are fitted, the holes 12f and 14f face one another. In this example, there are as many first holes 12f as there are second holes 14f.

(14) A sleeve 16 configured to receive an injector 18 is fastened in each first hole 12f, e.g. by welding or crimping. The sleeve 16 forms a border that projects outwardly along the axis of each first hole 12f. The maximum radius of the sleeve 16 is less than the radius of the second hole 14f. Thus, during fitting of the first and second walls 12 and 14, each blade 14g co-operates by snap-fitting with a sleeve 16.

(15) In order to block the blades 14g snap-fitting with the sleeves 16, after the first and second walls 12 and 14 have been fitted, a rim 20 is installed on the outside of the outer portion 12a of the first wall 12. By way of example, the rim 20 is welded on. Such a rim 20 provides intermediate blocking of the fitting of the walls 12 and 14 prior to installation of the injectors 18 that are described below and that form pins for locking the fitting. One or more rims may be provided. In this example, there are as many rims 20 as there are blades 14g. Naturally, these rims 20 are optional and they may thus be omitted in some combustion chamber variants.

(16) When the first and second walls 12 and 14 are axially fitted, the first holes 12f face the second holes 14f. An injector 18 is then inserted into each facing pair of first and second holes 12f and 14f, the injector forming a pin that locks the fitting of the first and second walls 12 and 14. The injectors 18 extend radially through each pair of holes 12f and 14f. The injectors 18 are engaged with clearance in each pair of holes so as to allow relative movements between each of the elements due to differential thermal expansion, but nevertheless they couple together the first and second walls 12 and 14 in translation along the axial direction X and in rotation in the azimuth direction Y. Naturally, the sleeve 16 also contributes to coupling together the first and second walls 12 and 14, but this coupling is relatively fragile, in particular because of thermal expansion differences that, under some circumstances, can cause the blades 14g to cease co-operating effectively with the sleeve 16, and in spite of the rims 20. Thus, the essential part of the locking of the fitting between the first and second walls 12 and 14 is provided by the pins formed by the injectors 18.

(17) Although the present invention is described with reference to specific embodiments, it is clear that modifications and changes may be made to these embodiments without going beyond the general ambit of the invention as defined by the claims. In particular, individual characteristics of the various embodiments shown and/or mentioned may be combined in additional embodiments. Consequently, the description and the drawings should be considered in a sense that is illustrative rather than restrictive.