Method to manufacture a hollow, single-piece bladed disc
A first insert ( 15 ) forming a ring is placed inside and in contact with a core ( 10 ) in degradable material. On the outer face of the core a plurality of inserts ( 20 ) is arranged each comprising a platform ( 21 ) applied against the outer face of the core and at least one blade ( 22 ) extending substantially radially outwards. A fibrous structure ( 56 ) is wound around the core passing over the platforms ( 21 ) and over the inner surface of the ring-shaped insert ( 15 ). Molding of the fibrous structure, impregnated with a composition containing a resin, is performed before polymerization of the resin and removal of the core.
1. Method to manufacture a hollow, single-piece bladed disc in composite material, comprising the steps of:
providing a ring-shaped core having an annular inner face, an outer annular face and two side faces,
placing in position a first insert forming a ring having an outer surface in contact with the inner face of the core and an inner surface,
arranging on the outer face of the core a plurality of second inserts each comprising a platform applied against the outer face of the core and at least one blade of the disc to be formed extending substantially radially outwards from the platform,
winding a fibrous structure around the core, comprising turns each passing along a side face of the core, over a platform of a second insert, along the other side face of the core and over the inner surface of the first insert, the wound fibrous structure forming an assembly of the second inserts with the first insert,
moulding the fibrous structure impregnated with a composition containing a resin,
polymerizing the resin, and
removing the core.
2. Method according to claim 1 , wherein the fibrous structure is formed by winding yarns, cable or tape in several stacked layers.
3. Method according claim 1 , wherein winding is performed on the platforms of the second inserts, between the blades.
4. Method according to claim 1 wherein, along a side face of the core, each turn segment follows a pathway forming a non-zero angle relative to the radial direction at the position of this segment.
5. Method according to claim 4 wherein, along a side face of the core, turn segments intersect forming non-zero angles of opposite sign relative to the radial direction at the position of these segments.
6. Method according to claim 1 , wherein a first insert is used having a U-shaped cross-section whose branch ends bear upon the inner face of the core.
7. Method according to claim 1 , wherein a first insert is used in composite material with fibrous reinforcement.
8. Method according to claim 1 , wherein second inserts are used with hollow blades.
9. Method according to claim 1 wherein third inserts are positioned on at least one of the side faces of the core to form connecting parts.
10. Method according to claim 1 wherein at least one fourth insert is positioned at the outer face of the core to form an annular reinforcement.
11. Method according to claim 10 , wherein fourth inserts forming reinforcement rings are arranged in housings in the outer face of the core in the vicinity of its side faces.
12. Method according to claim 1 , wherein on at least one of its side faces, the core has projecting pins and winding is made around the pins to form side orifices in the hollow disc after removal of the core.