Turbine unit for aircraft turbine engine with improved disc-cooling circuit

1. A turbine unit for an aircraft turbine engine, comprising:

a rotor disc ( 17 ) that extends about an axis (AX) while being continued axially along the axis (AX) by a rim ( 36 ), this rotor disc ( 17 ) carrying a plurality of radial blades ( 18 ) each comprising a root ( 21 ) inserted into a corresponding axial cell ( 23 ) formed on the periphery of the rotor disc ( 17 ), so that each pair formed by a cell ( 23 ) and a root ( 21 ) defines, between the cell ( 23 ) and the root ( 21 ), a channel for air flow ( 43 );

an annular flange ( 33 ), constrained to rotate with the rotor disc ( 17 ), extending axially towards the rotor disc ( 17 ), and which has a bearing end ( 34 ) extending radially towards the outside beyond the channels for air flow ( 43 ) while defining together with the rim ( 36 ) an air passage ( 42 ) communicating with the channels for air flow ( 43 ); and

a retaining member ( 32 , 32 ′) for axially retaining each of the blades in the corresponding cell ( 23 ), this retaining member ( 32 , 32 ′) being applied against the rotor disc ( 17 ) by the bearing end ( 34 ) of the annular flange ( 33 );

wherein at least one of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) comprises a groove ( 44 , 44 ′) extending in a circumferential direction and formed facing the other of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ), a sealing joint ( 45 ) being inserted into the groove ( 44 , 44 ′), and

wherein the other of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) axially bears against the sealing joint ( 45 ).

2. The turbine unit according to claim 1 , wherein the sealing joint ( 45 ) is mounted precompressed in the groove ( 44 , 44 ′).

3. The turbine unit according to claim 1 , wherein the joint ( 45 ) has a coefficient of thermal expansion greater than that of the rotor disc ( 17 ), of the flange ( 33 ) and of the retaining member ( 32 , 32 ′).

4. The turbine unit according to claim 1 ,

wherein the retaining member ( 32 ′) comprises at least one slot (V) that radially passes through the retaining member and at which the annular flange ( 33 ) does not bear against this retaining member ( 32 ′), and

wherein the groove ( 44 , 44 ′) is formed in the retaining member in such a way that the sealing joint ( 45 ) extends circumferentially at least along this slot (V).

5. The turbine unit according to claim 4 , wherein the retaining member ( 32 ′) is formed by an alternation of first and second angular segments ( 46 , 47 ) arranged circumferentially and in each of which a respective groove segment ( 46 c , 47 c ) is formed, so that the respective groove segments ( 46 c , 47 c ) of the first and second angular segments ( 46 , 47 ) extend in the circumferential continuation of each other to form the groove ( 44 ), the angular segments ( 46 , 47 ) further defining two by two a slot (V).

6. The turbine unit according to claim 5 , wherein the first and second angular segments ( 46 , 47 ) each comprise a respective body ( 46 a , 47 a ) having a flat shape, and a median part ( 46 b , 47 b ) axially protruding and disposed circumferentially at a distance from the circumferential ends of the body.

7. The turbine unit according to claim 4 , wherein said at least one slot (V) is equipped with a sealing member ( 48 ) running along the entire length thereof, the sealing member ( 48 ) being in the form of a coiled metal strip having its circumferential ends each bearing against a circumferential slot end ( 46 b , 47 a ).

8. The turbine unit according to claim 1 , wherein the groove ( 44 ′) is formed at the bearing end ( 34 ) of the annular flange ( 33 ), this bearing end comprising a first and a second portions ( 34 a , 34 b ) provided to bear against the retaining member ( 32 , 32 ′) while being located radially on either side of the groove ( 44 ′), and wherein the second bearing portion ( 34 b ) has a free radially outer end and is in the form of a tab, the thickness of which decreases as it moves away radially towards the outside.

9. A turbine ( 8 , 9 ) for an aircraft turbine engine comprising at least one turbine unit according to claim 1 , the turbine preferably being a low-pressure turbine ( 9 ).

10. An aircraft turbine engine ( 1 ) comprising at least one turbine ( 8 , 9 ) according to claim 9 , the turbine engine preferably being a two-spool turbine engine.

11. The turbine unit according to claim 1 ,

wherein the retaining member ( 32 , 32 ′) comprises the groove ( 44 , 44 ′) such that the groove ( 44 , 44 ′) faces the annular flange ( 33 ), and

wherein the annular flange ( 33 ) axially bears against the sealing joint ( 45 ).

12. The turbine unit according to claim 1 ,

wherein the annular flange ( 33 ) comprises the groove ( 44 , 44 ′) such that the groove ( 44 , 44 ′) faces the retaining member ( 32 , 32 ′), and

wherein the retaining member ( 32 , 32 ′) axially bears against the sealing joint ( 45 ).

13. A turbine unit for an aircraft turbine engine, comprising:

a rotor disc ( 17 ) that extends about an axis (AX) while being continued axially along the axis (AX) by a rim ( 36 ), this rotor disc ( 17 ) carrying a plurality of radial blades ( 18 ) each comprising a root ( 21 ) inserted into a corresponding axial cell ( 23 ) formed on the periphery of the rotor disc ( 17 ), so that each pair formed by a cell ( 23 ) and a root ( 21 ) defines, between the cell ( 23 ) and the root ( 21 ), a channel for air flow ( 43 );

an annular flange ( 33 ), constrained to rotate with the rotor disc ( 17 ), extending axially towards the rotor disc ( 17 ), and which has a bearing end ( 34 ) extending radially towards the outside beyond the channels for air flow ( 43 ) while defining together with the rim ( 36 ) an air passage ( 42 ) communicating with the channels for air flow ( 43 );

a retaining member ( 32 , 32 ′) for axially retaining each of the blades in the corresponding cell ( 23 ), this retaining member ( 32 , 32 ′) being applied against the rotor disc ( 17 ) by the bearing end ( 34 ) of the annular flange ( 33 );

a first groove ( 44 , 44 ′) formed in one of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) such that the first groove ( 44 , 44 ′) faces the other of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ); and

a sealing joint ( 45 ) being inserted into the first groove ( 44 , 44 ′), wherein the other of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) axially bears against the sealing joint ( 45 ).

14. The turbine unit according to claim 13 ,

wherein the first groove ( 44 , 44 ′) is formed in the retaining member ( 32 , 32 ′) such that the first groove ( 44 , 44 ′) faces the annular flange ( 33 ), and

wherein the annular flange ( 33 ) axially bears against the sealing joint ( 45 ).

15. The turbine unit according to claim 14 , further comprising a second groove ( 44 , 44 ′) formed in the annular flange ( 33 ) such that the second groove ( 44 , 44 ′) faces the retaining member ( 32 , 32 ′), wherein the sealing joint ( 45 ) is inserted into the first groove ( 44 , 44 ′) and the second groove ( 44 , 44 ′) such that the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) axially bear against the sealing joint ( 45 ).

16. The turbine unit according to claim 13 ,

wherein the first groove ( 44 , 44 ′) is formed in the annular flange ( 33 ) such that the first groove ( 44 , 44 ′) faces the retaining member ( 32 , 32 ′), and

wherein the retaining member ( 32 , 32 ′) axially bears against the sealing joint ( 45 ), at least one of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) comprises a groove ( 44 , 44 ′) extending in a circumferential direction and formed facing the other of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ), a sealing joint ( 45 ) being inserted into the groove ( 44 , 44 ′), and

wherein the other of the retaining member ( 32 , 32 ′) and the annular flange ( 33 ) axially bears against the sealing joint ( 45 ).