Bladed rotor structure having bifurcated blade roots

A rotor apparatus for axial flow coupling to a fluid, the apparatus comprising;

• (a) a rotor disc having circumferential rib attachment means including at least one ledge member on each side thereof;
• (b) an annular array of blades for contacting the fluid, each blade having a root portion externally engaging the ledge members on opposite sides of the attachment means, the blade extending outwardly from the root portion, the root portions having an aggregate circumferential thickness of slightly less than an associated circumference of the disc;
• (c) at least one pair of liner members, each pair of the liner members being located on opposite sides of the attachment means between the root portions of adjacent blades for spacing apart the adjacent blades, thereby adjusting the aggregate circumferential thickness of the root portions to suit the disc circumference, the liner members engaging the ledge members for preventing movement of the liner members radially outwardly from the disc, the liner members extending axially away from the attachment means to an outside contour portion that is inwardly displaced from the sides of the root portions;
• and
• (d) the root portion of at least one of the blades adjacent to each of the liner members being adapted for forming a retainer member extending circumferentially over a portion of the liner member, at least a portion of the retainer member being located at one side of the root portion and engaging the outside of the liner member, for preventing movement of the liner member axially away from the attachment means.

A method for assembling an axial flow fluid rotor disc apparatus, the method comprising the steps of:

• (a) selecting a rotor disc having circumferential rib attachment means;
• (b) providing an annular array of blades for contacting the fluid, the each blade having a root portion for externally engaging opposite sides of the attachment means with the blade extending outwardly from the root portion, the root portions having an aggregate circumferential thickness of slightly less than an associated circumference of the disc;
• (c) attaching the blades to the disc in engagement with the attachment means;
• (d) inserting at least one pair of liner members between the root portions of adjacent blades on opposite sides of the attachment means for spacing apart the adjacent blades, thereby adjusting the aggregate circumferential thickness of the root portions to suit the disc circumference;
• and
• (d) permanently deforming the root portion of at least one of the blades adjacent to each of the liner members for forming a retainer member thereon, the retainer member extending circumferentially over a portion of the liner member for preventing movement of the liner member away from the attachment means.