Gas turbine engine comprising an exhaust cone attached to the exhaust casing

1. An assembly comprising:

an exhaust casing of a gas turbine engine, the exhaust casing including a hub, an internal collar, an external collar, and a plurality of radial arms connecting the internal collar and the external collar; and

an exhaust cone for the gas turbine engine,

wherein the exhaust casing includes a first axial annular flange extending axially downstream from a downstream edge of the internal collar,

wherein the exhaust cone includes a second axial annular flange provided at an upstream end of the exhaust cone, an inside diameter of the second axial annular flange with respect to an axis of the gas turbine engine corresponds to an outside diameter of the first axial annular flange with respect to the axis of the gas turbine engine, and an outside diameter of the second axial annular flange with respect to the axis of the gas turbine engine corresponds to an outside diameter of the internal collar with respect to the axis of the gas turbine engine such that the internal collar and the second axial annular flange are continuous without any difference in level when passing from the internal collar to the second axial annular flange,

wherein the first and second axial annular flanges are engaged to each other, the second axial annular flange being radially, with respect to the axis of the gas turbine engine, external, the first axial annular flange being radially, with respect to the axis of the gas turbine engine, internal, and the first and second axial annular flanges being held together by mechanical attachment means passing through radial orifices provided in the first and second axial annular flanges,

wherein an inner circumferential surface of the second axial annular flange abuts, in a direction perpendicular to the axis of the gas turbine engine, an outer circumferential surface of the first axial annular flange,

wherein an upstream end of the second axial annular flange abuts, in a direction parallel to the axis of the gas turbine engine, the downstream edge of the internal collar, and

wherein one of the first and second axial annular flanges includes a radial protuberance and the other of the first and second axial annular flanges includes a means for axial guidanc of the radial protuberance, such that during an operation of assembling the first and second axial annular flanges with each other, the radial protuberance cooperates with the means for axial guidance of the radial protuberance so that the exhaust cone occupies an angular position that is predetermined with respect to the exhaust casing, the radial protuberance being circumferentially adjacent to one of the radial orifices provided in the one of the first and second axial annular flanges.

2. The assembly according to claim 1 , wherein the mechanical attachment means include screws engaged in the radial orifices in the second axial annular flange cooperating with the radial orifices in the first axial annular flange which are tapped, or the radial orifices being provided in nuts attached to the first axial annular flange which are tapped.

3. The assembly according to claim 2 , wherein heads of the screws are at least in part embedded in a thickness of a wall of the second axial annular flange.

4. The assembly according to claim 1 , wherein the first and second axial annular flanges are held on each other also by press fitting.

5. The assembly according to claim 1 , wherein the radial protuberance is a pin or rivet attached to the one of the first and second axial annular flanges.

6. The assembly according to claim 1 , wherein at least one of the first and second axial annular flanges comprises radial scallops.

7. The assembly according to claim 6 , wherein the means for axial guidance of the radial protuberance comprises a groove, a bottom of which is at a distance from an axis of the cone which is less than a distance from a bottom of the radial scallops to the axis of the cone.

8. A gas turbine comprising:

an assembly, the assembly comprising:

an exhaust casing of the gas turbine engine, the exhaust casing including a hub, an internal collar, an external collar, and a plurality of radial arms connecting the internal collar and the external collar: and

an exhaust cone for the gas turbine engine,

wherein the exhaust casing includes a first axial annular flange extending axially downstream from a downstream edge of the internal collar,

wherein the exhaust cone includes a second axial annular flange provided at an upstream end of the exhaust cone, an inside diameter of the second axial annular diameter of the first axial annular flange with respect to the axis of the gas turbine engine, and an outside diameter of the second axial annular flange with respect to the axis of the gas turbine engine corresonds to an outside diameter of the internal collar with respect to the axis of the gas turbine engine such that the internal collar and the second axial annular flange are continuous without any difference in level when passing from the internal collar to the second axial annular flange,

wherein the first and second axial annular flanges are engaged to each other, the second axial annular flange radially, with respect to the axis of the gas turbine engine, external, the first axial annular flange being radially, with respect to the axis of the gas turbine engine, internal, and the first and second axial annular flanges being held together by mechanical attachment means passing through radial orifices provided in the first and second axial annular flanges,

wherein an inner circumferential surface of the second axial annular flange abuts, in a direction perpendicular to the axis of the gas turbine engine, an outer circumferential surface of the first axial annular flange,

wherein an upstream end of the second axial annular flange abuts, in a direction parallel to the axis of the gas turbine engine, the downstream edge of the internal collar, and

wherein one of the first and second axial annular flanges includes a radial protuberance and the other of the first and second axial annular flanges includes a means for axial guidance of the radial protuberance, such that during an operation of assembling the first and second axial annular flanges with each other, the radial protuberance cooperates with the means for axial guidance of the radial protuberance so that the exhaust cone occupies an angular position that is predetermined with respect to the exhaust casing, the radial protuberance being circumferentially adjacent to one of the radial orifices provided in the one of the first and second axial annular flanges.