TURBINE WITH PRESSURISED CAVITIES

Abstract

A turbine has a first rotor and a second rotor configured to pivot about a longitudinal axis (X) according to two opposite directions of rotation. The first rotor has a radially outer drum from which bladesextend radially inwards. The first rotorand the second rotor are surrounded by a stator annular part. The stator annular partdelimits, with the drum, at least one upstream annular cavityand one downstream annular cavityseparated from each other by sealing means.

Description

Claims

1. A turbine engine, such as an airplane turboprop engine or turbojet engine, comprising a turbine comprising a first rotor and a second rotor configured to pivot about a longitudinal axis (X) according to two opposite directions of rotation, the first rotor including a radially outer drum from which blades extend radially inwards, the first rotor and the second rotor being surrounded by a stator annular part, wherein said stator annular part delimits with the drum at least one upstream annular cavity and one downstream annular cavity separated from each other by sealing means, the upstream annular cavity being connected to first means for supplying cooling air at a first pressure and the downstream annular cavity being connected to second means for supplying cooling air at a second pressure lower than the first pressure, the first cooling air supply means being connected upstream to first means for drawing air in a compressor, and/or wherein the second cooling air supply means are connected upstream to second means for drawing air in an annular secondary air flow path which extends radially outwards of said stator annular part.

2. The turbine engine according to claim 1, wherein the upstream annular cavity fluidly communicates with an annular air flow path inside which the blades extend, the annular flow path being delimited radially outwards by the drum of the first rotor and being delimited radially inwards by a radially inner drum of the second rotor.

3. The turbine engine according to claim 2, wherein the upstream end of the drum of the first rotor delimits with the stator annular part a first annular air passage with the annular air flow path inside which the blades extend.

4. The turbine engine according to claim 2, wherein the downstream annular cavity fluidly communicates with the annular air flow path inside which the blades extend.

5. The turbine engine according to claim 4, wherein the downstream end of the drum of the first rotor delimits with the stator annular part a second annular air passage with the annular air flow path inside which the blades extend.

6. The turbine engine according to claim 1, wherein at least one annular housing is formed at a junction of at least one blade of the first rotor with the drum of the first rotor.

7. The turbine engine according to claim 6, wherein a first annular housing fluidly communicates with the upstream annular cavity .

8. The turbine engine according to claim 7, wherein the first annular housing is formed at the blade arranged at the upstream end of the drum of the first rotor.

9. The turbine engine according to claim 6, wherein a second annular housing is arranged radially opposite the downstream annular cavity.

10. The turbine engine according to claim 1, wherein the second air supply means comprise means for controlling opening/closure of the air supply.

11. The turbine engine according to claim 1, wherein the drum of the first rotor is frustoconical with a section increasing downstream.