Turbomachine

1. A turbo machine comprising:

a turbo stator having a shroud;

a turbo rotor having an impeller within the shroud;

a brush seal between the impeller and the shroud;

a main cavity portion upstream of the brush seal, the main cavity portion being defined by a recessed surface of the shroud and a surface of the impeller;

at least one vane extending from the shroud towards the impeller being disposed at least partially within the main cavity and upstream of the brush seal; and

a labyrinth seal arranged downstream of the brush seal between the impeller and the shroud.

2. The turbo machine of claim 1 wherein the at least one vane comprises:

an upstream end;

a downstream end;

a first side extending between the upstream end and the downstream end; and

a second side extending between the upstream end and the downstream end.

3. The turbo machine of claim 1 wherein the shroud has a surface facing the impeller and the at least one vane comprises an impeller facing surface having an upstream end intersecting the shroud surface and a downstream end intersecting the shroud surface, the impeller facing surface being substantially congruent to the impeller from the upstream end to the downstream end.

4. The turbo machine of claim 1 wherein the at least one vane defines a plane coincident with a rotor axis.

5. The turbo machine of claim 1 wherein the impeller has an outer diameter and the at least one vane extends radially outwardly beyond the outer diameter of the impeller.

6. The turbo machine of claim 1 wherein the recessed surface of the shroud defining the main cavity portion comprises a step defined by a planar shroud surface normal to a rotor axis and a cylindrical shroud surface upstream of the planar shroud surface, the cylindrical shroud surface intersecting the planar shroud surface.

7. The turbo machine of claim 6 wherein the at least one vane defines a triangle shape, a first side of the triangle intersects the planar shroud surface, a second side of the triangle intersects the cylindrical shroud surface, and a third side of the triangle faces the impeller.

8. A shroud, an impeller, and a brush seal assembly in a turbo machine, the assembly comprising:

at least one vane being disposed at least partially within a main cavity and upstream of the brush seal and extending from a shroud surface towards the impeller of the turbo machine, wherein the main cavity portion is upstream of the brush seal and is defined by a recessed surface of the shroud and a surface of the impeller, the at least one vane comprising:

an upstream end;

a downstream end;

a first side extending between the upstream end and the downstream end;

a second side extending between the upstream end and the downstream end; and

an impeller facing surface having an upstream end intersecting the shroud surface and a downstream end intersecting the shroud surface, the impeller facing surface being substantially congruent to the impeller from the upstream end of the impeller facing surface to the downstream end of the impeller facing surface; and

a labyrinth seal arranged downstream of the brush seal between the impeller and the shroud.

9. The assembly of claim 8 wherein the at least one vane defines a plane coincident with a rotor axis.

10. The assembly of claim 8 wherein the impeller has an outer diameter and the at least one vane extends radially outwardly beyond the outer diameter of the impeller.

11. The assembly of claim 8 wherein the recessed surface of the shroud defining the main cavity portion comprises a step defined by a planar shroud surface normal to a rotor axis and a cylindrical shroud surface upstream of the planar shroud surface, the cylindrical shroud surface intersecting the planar shroud surface.

12. The assembly of claim 11 wherein the at least one vane defines a triangle shape, a first side of the triangle intersects the planar shroud surface, a second side of the triangle intersects the cylindrical shroud surface, and a third side of the triangle faces the impeller.

13. A method of improving sealing and reducing swirl in a turbo machine, the method comprising:

providing a brush seal between an impeller and a shroud of the turbo machine;

providing a labyrinth seal arranged downstream of the brush seal between the impeller and the shroud;

providing a cavity between the impeller and the shroud upstream of the brush seal, wherein the cavity is defined by a recessed surface of the shroud and a surface of the impeller; and

providing the cavity with at least one vane extending towards the impeller.

14. The method of claim 13 wherein the shroud has a surface facing the impeller and the at least one vane comprises an impeller facing surface having an upstream end intersecting the shroud surface and a downstream end intersecting the shroud surface, the impeller facing surface being substantially congruent to the impeller from the upstream end to the downstream end.

15. The method of claim 13 wherein the impeller has an outer diameter and the at least one vane extends radially outwardly beyond the outer diameter of the impeller.

16. The method of claim 13 wherein the recessed surface of the shroud defining the cavity comprises a step defined by a planar shroud surface normal to a rotor axis and a cylindrical shroud surface upstream of the planar shroud surface, the cylindrical shroud surface intersecting the planar shroud surface.

17. The method of claim 16 wherein the at least one vane defines a triangle shape, a first side of the triangle intersects the planar shroud surface, a second side of the triangle intersects the cylindrical shroud surface, and a third side of the triangle faces the impeller.