Centripetal air bleed from a turbomachine compressor rotor

1. A compressor rotor of a turbomachine, the rotor comprising:

at least first and second successive disks on a common axis carrying blades which are successive along the axis, the at least first and second successive disks being connected together by a generally tubular wall forming a surface of revolution about said axis; and

centripetal air bleed means comprising air passages passing through the generally tubular wall near the second disk, the centripetal air bleed means opening out, near the first disk, into a chamber formed radially inside the generally tubular wall and between the two disks,

wherein the centripetal air bleed means comprises:

an air-guide wall mounted inside the chamber and comprising a substantially cylindrical portion extending along the generally tubular wall and at a small radial distance therefrom so as to define with the generally tubular wall an annular passage for axial flow of the air stream leaving the passages, the generally tubular wall extending up to the first disk of the rotor.

2. A rotor according to claim 1 , wherein the air passages passing through the generally tubular wall are inclined relative to the axis of the rotor.

3. A rotor according to claim 1 , wherein the air passages are formed through a downstream end portion of the wall, downstream from a labyrinth seal for co-operating with a nozzle mounted between the two disks of the rotor.

4. A rotor according to claim 1 , wherein the guide wall is fitted against and fastened to one of the disks inside the chamber.

5. A rotor according to claim 4 , wherein the guide wall is sectorized.

6. A rotor according to claim 4 , wherein the guide wall includes an annular flange at one end for fastening to an annular flange of the tubular wall and to one of the disks.

7. A rotor according to claim 1 , wherein the axial annular flow passage for the air stream is of a section that is substantially constant.

8. A rotor according to claim 1 , wherein the cylindrical portion of the guide wall carries studs bearing against the tubular wall to limit vibration and bending of the guide wall in operation.

9. A rotor according to claim 1 , wherein the guide wall includes at one end a radial rim that extends along the first disk towards the axis of rotation over a fraction of the radial dimension of the chamber.

10. A compressor rotor of a turbomachine, the rotor comprising:

at least two disks on a common axis carrying blades and connected together by a generally tubular wall forming a surface of revolution coaxially about the axis of the disk;

centripetal air bleed means comprising air passages passing through the wall and opening out into a chamber formed inside the tubular wall and between the two disks; and

an air-guide wall mounted inside the chamber and comprising a substantially cylindrical portion extending along the tubular wall and at a small radial distance therefrom so as to co-operate with the wall to define an annular passage for axial flow of the air stream leaving the passages and extending up to one of the disks of the rotor,

wherein the guide wall includes at one end a radial rim that extends along one of the disks towards the axis of rotation over a fraction of the radial dimension of the chamber, and

wherein the radial rim carries fins for at least one of deflecting or slowing down the air stream, which fins are pressed against the disk.

11. A rotor according to claim 10 , wherein the fins are inclined so that, in operation, the fins produce a suction effect on the air stream.

12. A rotor according to claim 9 , wherein an end of the guide wall opposite from the radial rim is pressed against the generally tubular wall and prevents air leaving the through passages from flowing along the second disk.

13. A rotor according to claim 1 , wherein the guide wall is made of a light metallic material or of a composite material.

14. A turbomachine comprising a compressor rotor, the compressor rotor comprising:

at least first and second successive disks on a common axis carrying blades which are successive along the axis, the at least first and second successive disks being connected together by a generally tubular wall forming a surface of revolution about said axis; and

centripetal air bleed means comprising air passages passing through the generally tubular wall near the second disk, the centripetal air bleed means opening out, near the first disk, into a chamber formed radially inside the generally tubular wall and between the two disks,

wherein the centripetal air bleed means comprises:

an air-guide wall mounted inside the chamber and comprising a substantially cylindrical portion extending along the generally tubular wall and at a small radial distance therefrom so as to define with the generally tubular wall an annular passage for axial flow of the air stream leaving the passages, the generally tubular wall extending up to the first disk of the rotor.

15. A rotor according to claim 1 , wherein, in the flowing direction for air along said common axis, in the compressor rotor, the second disk is located downstream from the first disk, so that, in the annular passage for axial flow of the air stream, air circulates from downstream to upstream.

16. A compressor rotor of a turbomachine, the rotor comprising:

at least two disks on a common axis carrying blades and connected together by a generally tubular wall forming a surface of revolution coaxially about the axis of the disk;

centripetal air bleed means which comprises air passages passing through the wall and which opens out into a chamber formed radially inside the tubular wall and between the two disks; and

an air-guide wall mounted inside the chamber, the air-guide wall comprising:

a substantially cylindrical portion extending along the tubular wall and at a small radial distance therefrom so as to define with the wall an annular passage for axial flow of the air stream extending up to one of the disks of the rotor,

a curvature in front of said one of the disks, which extends the substantially cylindrical portion at an end, and which deviates the air stream in contact with said one of the disks, and

a radial rim which extends the curvature along said one of the disks, towards the axis of rotation over a fraction of the radial dimension of the chamber.

17. A rotor according to claim 16 , wherein the at least two disks and the generally tubular wall are formed in one piece only.

18. A rotor according to claim 16 , wherein:

the at least two disks comprises a first and a second successive disks on said common axis,

the carried blades are successive along the axis,

the air passages pass through the tubular wall near the second disk, and

said one of the disks in front of which the curvature is situated and in contact to which the air stream is deviated is the first disk.

19. A rotor according to claim 16 , wherein:

the at least two disks are successive on said common axis and comprise respectively a first disk and a second disk located downstream from the first disk,

the air passages passes through the tubular wall near the second disk, and

said one of the disks in front of which the curvature is situated and in contact to which the air stream is deviated is the first disk.