Provision of sealing in a jet engine for bleeding air to the cabin using a tube with a double ball joint
View Patent ↗A jet engine that provides for the sealing of bleeding air to the cabin, the air passing through a cavity delimited, on the one hand, by the external shell of the compressor and an annular structure connected to the shell, and, on the other hand, by the external casing of the diffuser grating and a strut connected to the external casing and to an external engine casing shell, this external casing shell being fastened to the annular structure by bolting. A tube is provided between the orifice in the strut and the outlet vent, a first end of which tube is mounted in the outlet vent by a connection which is free to rotate and prevented from translational movement, and a second end of which tube is mounted in the orifice by a connection which is free to rotate and free to move translationally.
1. A jet engine comprising, from an upstream direction to a downstream direction, wherein the upstream and downstream directions are defined by a direction of circulation of a primary flow, said jet engine comprising:
a high-pressure compressor,
a diffuser grating and
a combustion chamber,
said high-pressure compressor comprising an external shell which radially delimits a duct for said primary flow and is connected to an annular structure extending radially outward,
said diffuser grating comprising in an axial continuation of said external shell an external casing connected to a rearwardly oriented oblique strut delimiting, upstream, an end of said combustion chamber, said strut itself being connected to an external casing shell which extends in the upstream direction and is fastened to said annular structure by fastening means, said strut, said external casing shell and said annular structure defining a cavity around said diffuser grating, air bleed orifices being made in said strut in order to bring the end of the combustion chamber into communication with said cavity, said external casing shell being equipped with air bleed vents, wherein a tube is provided between an orifice in the strut and an outlet vent, a first end of said tube is mounted in said outlet vent by a connection which is free to rotate and prevented from translational movement, and a second end of said tube is mounted in said orifice by a connection which is free to rotate and free to move translationally.
2. The jet engine as claimed in claim 1 , wherein the first and second ends of the tube each comprise a spherical surface portion at their periphery.
3. The jet engine as claimed in claim 2 , wherein the orifice in the strut is formed by a cylindrical bore whose diameter is substantially equal to a diameter of the spherical surface portion of the second tube end.
4. The jet engine as claimed in claim 1 , wherein the outlet vent comprises an orifice made in a wall of the external casing shell, said orifice being delimited by a cylindrical portion situated toward an external face of said shell and by a spherical surface portion situated toward an internal face and connected to a preceding portion, said cylindrical and spherical surface portions having a diameter which is substantially equal to the diameter of the spherical surface portion of the first tube end.
5. The jet engine as claimed in claim 1 , wherein the tube is made of a material having substantially a same coefficient of expansion as a material constituting the strut and the external casing shell.
6. The jet engine as claimed in claim 5 , wherein the tube, the strut and the external casing shell are made of the same material.
7. The jet engine as claimed in claim 1 , wherein surfaces of the connections are treated with a product which protects elements in contact and improves relative sliding movements.
8. The jet engine as claimed in claim 7 , wherein the product is a graphite-containing ceramic varnish.