Turbine module for a gas-turbine engine with rotor that includes a monoblock body

1. A turbine module for a gas-turbine engine with a turbine rotor composed of four disks at least, including a first disk, a second disk adjacent to said first disk, a third disk adjacent to said second disk and a forth disk adjacent to said third disk, said four disks supporting blades on their periphery, said second and third disks forming a monoblock body, wherein said monoblock body includes two lateral inter-disk ferrules, including a first lateral inter-disk ferrule and a second lateral inter-disk ferrule, wherein said first lateral inter-disk ferrule is bolted to said first disk, and said second lateral inter-disk ferrule is bolted to said forth disk.

2. A module according to claim 1 , further comprising a first inter-stage ring between said first disk and the monoblock body, and a second inter-stage ring between the monoblock body and said forth disk.

3. A module according to claim 2 , wherein said first and second inter-stage rings also form an axial end-stop for the mobile blades.

4. A module according to claim 2 , wherein said first and second rings each form a passage for cooling air with said first and second inter-disk ferrules respectively.

5. A turbine module according to claim 1 , further comprising at least annular distributors between turbine stages, where said annular distributors include a plurality of elements in the form of a ring sector in which a first part supports fixed blades located radially to the axis of the turbine, and a second part which forms a seal with tips of the turbine rotor blades, and where said elements in the form of a ring sector are held inside a casing by latching devices.

6. A module according to claim 5 , further comprising an axial hook attached to the casing or to said element, that engages with a pair of axial hooks attached respectively to said element or the casing.

7. A module according to one of claims 5 and 6 , further comprising, on an upstream part of said element, a ring sector.

8. A module according to claim 7 , further comprising an axial hook on the casing, which fits together with a pair of axial hooks attached to said element in the form of a ring sector, in such a way that a downstream end of a ring sector for sealing of the rotor placed upstream is held between said axial hooks.

9. A turbine module according to claim 1 , wherein said first lateral inter-disk ferrule is welded to said second disk, and said second lateral inter-disk ferrule is welded to said third disk.

10. A turbine module according to claim 9 , wherein said monoblock body includes a monoblock ferule between said second and third disks, and

wherein said monoblock ferule, said first and second lateral inter-disk ferrules, said second disk and said third disk form a single block welded together.

11. A turbine module according to claim 10 , wherein said monoblock ferule includes at least one sealing lip oriented transversally with respect to an axis of said gas-turbine engine and facing a distributor of said gas-turbine engine.

12. A turbine module according to claim 10 , wherein said monoblock ferule includes two sealing lips oriented transversally with respect to an axis of said gas-turbine engine and facing a distributor of said gas-turbine engine.

13. A turbine module according to claim 10 , wherein said monoblock body includes two welding zones, a first welding zone between said second disk and said monoblock ferule and a second welding zone between said monoblock ferule and said third disk.

14. A turbine module according to claim 13 , wherein said monoblock ferule includes two sealing lips oriented transversally with respect to an axis of said gas-turbine engine and facing a distributor of said gas-turbine engine, and wherein said two sealing lips are positioned between said first and second welding zones.