Set of rotor disks for a turbine engine
A set of rotor disks for a turbine engine, or an airplane turboprop or turbojet, the set including disks rigidly connected together by bolts and shaped at their outer peripheries with slots for mounting blade roots. Each disk includes a rim extending radially and not having any axial flanges, two consecutive disks being connected together with help of an axially-extending ferrule that is fastened to the rims of the disks and that is fitted with a holder plate for holding the blade roots of the downstream disk.
1. A set of rotor disks for a turbine engine, or an airplane turboprop or a turbojet, the set comprising:
an upstream disk and a downstream disk rigidly connected together by bolts and shaped at outer peripheries thereof with slots for mounting blade roots, each disk including a rim extending radially and free of any axial flanges; and
an axially-extending ferrule that is fastened to the rims of the disks and that is fitted with a holder plate for holding blade roots of the downstream disk,
wherein the ferrule includes a frustoconical middle portion, an upstream cylindrical margin at an upstream end of the ferrule, and a downstream cylindrical margin at a downstream end of the ferrule, the upstream and downstream cylindrical margins being pressed against the rims of the upstream and downstream disks, respectively, and the downstream end of the ferrule being radially outward of the upstream end of the ferrule, and
wherein the ferrule includes cooling openings near the downstream end, the openings opening out into a ventilation space formed upstream from the downstream disk and defined by the ferrule and the holder plate for holding the blade roots.
2. A set according to claim 1 , further comprising balance weights formed at radially inner ends of the rims.
3. A set according claim 1 , wherein the axial ends of the ferrule include annular flanges fastened to the rims of the upstream and downstream disks via the bolts.
4. A set according to claim 1 , wherein the middle portion includes wipers for co-operating with blocks of abradable material mounted on stationary vanes of a guide vane stage.
5. A set according to claim 4 , wherein the middle portion includes a cylindrical ledge extending upstream and carrying the wipers.
6. A set according to claim 1 , wherein the holder plate for holding the blade roots of the downstream disk is formed integrally with the ferrule.
7. A set according to claim 1 , wherein the holder plate is a you that is separate from the ferrule and that is mounted to bear between an outwardly extending annular bead of the ferrule and the downstream disk.
8. A set according to claim 1 , wherein each of the upstream and downstream disks includes a shoulder against which the upstream and downstream cylindrical margins radially abut, respectively.
9. A set according to claim 1 , further comprising an upstream plate including an annular portion pressed against the rim of the upstream disk and a portion for holding blade roots in the slots of the upstream disk.
10. A turbine engine, an airplane turboprop, or a turbojet, comprising a low pressure turbine in which the rotor disks are formed by a set of disks according to claim 1 .