Gas turbine engine rotor ventilation arrangement

Abstract

A rotor assembly for a gas turbine engine, the rotor assembly comprises at least two rotors defining a cavity therebetween. A first rotor defines a cooling air inlet in its radially inward portion. A second rotor defines a cooling air outlet in its radially outward portion, such that the cooling air passes radially outwardly through the cavity.

Description

Embodiments of the invention will now be described by way of example only, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a sectional side view of a gas turbine engine.

FIG. 2 is a sectional side view of part of a prior art compressor of the engine shown in FIG. 1.

FIG. 3 is a sectional side view of part of a second prior art compressor of the engine shown in FIG. 1.

FIG. 4 is a sectional side view of part of a first embodiment of a ventilation arrangement of the compressor of the engine shown in FIG. 1 in accordance with the present invention.

FIG. 5 is a sectional side view of part of a second embodiment of a ventilation arrangement of the compressor of the engine shown in FIG. 1 in accordance with the present invention.

FIG. 6 is a view (arrow C in FIG. 4) on a part of a rotor disc of the present invention.

Claims

1. A rotor assembly for a gas turbine engine, the rotor assembly comprises at least two rotors defining a cavity therebetween; a first rotor defines a cooling air inlet in its radially inward portion, characterized in that a second rotor defines a cooling air outlet in its radially outward portion, such that the cooling air passes radially outwardly through the cavity.

2. A rotor assembly as claimed in claim 1, wherein the rotor assembly comprises a third rotor stage defining a second cavity with the second stage, the cooling air that passes through the outlet then passes into and radially inwardly through the second cavity to pass through the bore of the third rotor.

3. A rotor assembly as claimed in claim 2, wherein the rotor assembly comprises a fourth rotor defining a third cavity with the third stage, the cooling air that passes through the bore of the third stage then passes into and radially outwardly through the third cavity to pass through a cooling air outlet defined in a radially outward portion of the fourth stage.

4. A rotor assembly as claimed in claim 3, wherein the rotor assembly comprises a fifth rotor defining a fourth cavity with the first rotor, at least one inlet is defined in a shroud of the first or fifth rotor, the cooling enters the fourth cavity via the inlet and passes radially inwardly through the fourth cavity and into the first cavity via the bore of the first rotor.

5. A rotor assembly as claimed in claim 4, wherein the fifth rotor defines a bore and the cooling entering the fourth cavity passes through the bore of the fifth rotor.

6. A rotor assembly as claimed in claim 4, wherein the rotor assembly comprises a sixth rotor defining a fifth cavity with the fifth rotor, at least one outlet is defined in the radially outer part of the sixth rotor, the cooling air entering the fifth cavity passes radially outwardly between the bore of the fifth rotor and the outlet.

7. A rotor assembly as claimed in claim 1, wherein the cooling air passes in a generally rearward direction through the rotor assembly.

8. A rotor assembly as claimed in claim 1, wherein the cooling air passes in a generally forward direction through the rotor assembly.

9. A rotor assembly as claimed in claim 4, wherein the cooling air passing the first, second, third and fourth rotors passes in a rearward direction and the cooling air passing the fifth and sixth rotors passes in a forward direction.

10. A rotor assembly as claimed in claim 1, wherein at least one of the cooling air outlets is angled in the axial direction.

11. A rotor assembly as claimed in claim 1, wherein at least one of the cooling air outlets is angled tangentially such that the cooling air has a component of velocity in the tangential direction.

12. A rotor assembly as claimed in claim 11, wherein the cooling air outlet is angled tangentially in the direction of rotation of the disc.

13. A rotor assembly as claimed in claim 11, wherein the cooling air outlet is angled tangentially in the opposite direction of rotation of the disc.

14. A rotor assembly as claimed in claim 1, wherein at least one of the cooling air outlets is angled radially such that the cooling air has a component of velocity in the radial direction.

15. A rotor assembly as claimed in claim 14, wherein the cooling air outlet is angled radially inwardly or radially outwardly.

16. A rotor assembly as claimed in claim 1, wherein the cooling air inlet is a bore of the first rotor.

17. A rotor assembly as claimed in claim 1, wherein a shaft passes through the bore of at least some of the rotor stages of the rotor assembly.

18. A rotor assembly as claimed in claim 17, wherein a seal is provided between the shaft and any one or more of the group comprising the second, the fourth and the sixth rotors.

19. A rotor assembly as claimed in claim 5, wherein the seal is a labyrinth seal.

20. A rotor assembly as claimed in claim 5, wherein the seal comprises a small clearance between the bore of the rotor and the shaft such that the airflow into the respective cavity preferentially passes through the cooling air outlet.

21. A rotor assembly as claimed in claim 1 wherein the assembly is a compressor assembly.

22. A rotor assembly as claimed in claim 1 wherein the assembly is a turbine assembly.

23. A gas turbine engine 10 comprising a rotor assembly as claimed in claim 1.