Combustion chamber comprising means for cooling an annular casing zone downstream of a chimney

1. A combustion chamber for a turbomachine, comprising:

a longitudinal axis;

an annular casing delimiting an inner volume of the combustion chamber and provided with a chimney extending radially outward relative to the longitudinal axis, to an outside of the inner volume and delimiting a passage for a penetrating part through the annular casing, the chimney having a central axis, and a bushing mounted floating on the chimney;

a main air collection chamber, open on an upstream end thereof and closed on a downstream end thereof in a direction of flow of gases in the turbomachine, arranged radially facing a downstream portion of the chimney relative to the central axis; and

at least one through-opening formed in a portion of the annular casing delimiting a radially inward end of the main air collection chamber relative to the longitudinal axis so as to put into direct communication the inner volume of the combustion chamber and the main air collection chamber,

wherein a radially outward end of the main air collection chamber relative to the longitudinal axis is closed by a collar extending radially outward relative to the central axis from the chimney, and

wherein the downstream end of the main air collection chamber is closed by an outer wall that extends at a distance from and radially faces the downstream portion of the chimney relative to the central axis, the outer wall connecting the annular casing to the collar.

2. The combustion chamber according to claim 1 , further comprising a deflector arranged in the inner volume of the combustion chamber, connected to a region of the annular casing that is closer to the central axis of the chimney than the at least one through-opening, the deflector extending beyond and facing the at least one through-opening, whereupon a space of formation of parietal cooling air film, closed on an upstream end thereof and open on a downstream end thereof, is defined between the annular casing and the deflector.

3. The combustion chamber according to claim 2 , wherein the deflector comprises a proximal portion in the form of a ring portion through which the deflector is connected to said region of the annular casing, and a free distal portion extending facing and beyond the at least one through-opening.

4. The combustion chamber according to claim 1 , wherein the main air collection chamber is in the form of a ring portion and has two opposite respective circumferential ends open on the upstream end thereof.

5. The combustion chamber according to claim 1 , wherein the main air collection chamber is closed on the side opposite the annular casing.

6. The combustion chamber according to claim 1 , further comprising a secondary air collection chamber, open on an upstream end thereof and closed on a downstream end thereof, arranged facing the downstream portion of the chimney, and wherein the downstream portion of the chimney comprises air passage orifices putting into direct communication the passage and the secondary air collection chamber.

7. The combustion chamber according to claim 6 , wherein the secondary air collection chamber is in the form of a portion of a ring and has two opposite respective circumferential ends open on the upstream end thereof.

8. The combustion chamber according to claim 6 , wherein the secondary air collection chamber is arranged between the chimney and a portion at least of the main air collection chamber.

9. The combustion chamber according to claim 1 , wherein the annular casing is formed at least by:

an annular wall provided with an orifice, and

an annular flange of an additional part, housed in the orifice of the annular wall, and

wherein the additional part further comprises at least:

a tubular wall forming the chimney, and from which the annular flange extends further away from the central axis of the chimney, said annular flange comprising the at least one through-opening, and

the main air collection chamber.

10. The combustion chamber according to claim 9 , further comprising a deflector arranged in the inner volume of the combustion chamber, connected to a region of the annular casing that is closer to the central axis of the chimney than the at least one through-opening, the deflector extending beyond and facing the at least one through-opening, whereupon a space of formation of parietal cooling air film, closed on an upstream end thereof and open on a downstream end thereof, is defined between the annular casing and the deflector,

wherein the deflector comprises a proximal portion in the form of a ring portion through which the deflector is connected to said region of the annular casing, and a free distal portion extending beyond and facing the at least one through-opening,

wherein the additional part further comprises said region of the annular casing to which the deflector is connected, and the deflector.

11. The combustion chamber according to claim 9 , further comprising a secondary air collection chamber, open on an upstream end thereof and closed on a downstream end thereof, arranged facing the downstream portion of the chimney, and wherein the downstream portion of the chimney comprises air passage orifices putting into direct communication the passage and the secondary air collection chamber,

wherein the additional part further comprises the secondary air collection chamber.

12. A turbomachine for an aircraft, comprising a combustion chamber according to claim 1 , and a penetrating part extending through the chimney.

13. The turbomachine according to claim 12 , wherein the penetrating part is a spark plug.