Patent ID: 8419369

Claim:
An axial flow hydraulic turbine with fixed blade mounting comprising: a plurality of runner blades for the hydraulic turbine, each of the runner blades comprising a mounting flange including a hub abutting surface portion, and a plurality of threaded flange apertures extending from the hub abutting surface portion into the hub mounting flange, wherein the hub abutting surface portion is non-circular in cross-section, and the plurality of threaded flange apertures being arranged across the hub abutting surface portion in a first array like pattern; a hollow hub for supporting the runner blades and comprising a central opening and an outer surface portion, wherein the hub extends annularly as a continuous structure around an axis of the hub, the outer surface portion of the hub includes a plurality of recesses, each of the recesses having a flange seating surface portion for seating a corresponding hub abutting surface portion of the hub mounting flange, wherein the recess includes a sidewall extending around the flange seating surface portion and the sidewall is complementary to the non-circular cross-section of the hub abutting surface portion, and the recess having a plurality of hub apertures extending from the flange seating surface portion through the hollow hub and opening into the central opening, the plurality of hub apertures being arranged across the flange seating surface portion in a second array like pattern, each of the hub apertures in the second array like pattern aligning with a corresponding one of the threaded flange apertures of the first array like pattern; whereby the first and second array like patterns are complementary; and a plurality of bolting connections, one for each aligned hub aperture and threaded flange aperture, for securing the plurality of runner blades to the hollow hub, each bolting connection having a bolt head-like portion located within the central opening of the hollow hub and having a threaded shaft portion extending through a corresponding aligned hub aperture and threaded flange aperture for threading engagement with the threaded flange aperture.