Turbine blade

Claim 1

An air-cooled type turbine blade structure for mounting on a rotor having an axis of rotation, said structure comprising: root means for attaching said blade structure to the rotor, web plate means disposed radially outwardly of said root means with respect to said axis, solid blade core means disposed radially outwardly of said web plate means, blade jacket means surrounding said core means and including discharge apertures arranged over the surface thereof for discharging cooling air, a plurality of longitudinal radially extending rib means and a plurality of cross rib means interconnecting respective adjacent longitudinal rib means being arranged on the surface of said core means, said jacket means being attached to the outer edges of the respective rib means to form a set of first hollow spaces between said jacket means and the surface of said core means which are bounded by said respective rib means, channel means extending through said web plate means for communicating the radially innermost first hollow spaces between respective adjacent longitudinal rib means with cooling air supply means, and aperture means extending through said cross rib means for communicating said radially innermost first hollow spaces with first hollow spaces arranged radially outwardly thereof, said aperture means being dimensioned as throttling spaces for effecting a predetermined distribution of cooling air throughout the various first hollow spaces arranged on the surface of the blade core means, wherein said Web plate means includes recess means formed in a radially outwardly facing surface, a sheet metal member being provided for covering said recess means to form a plurality of second hollow spaces between said sheet metal member and said web plate means, each of said second hollow spaces extending to a position directly radially inwardly with respect to a respective radially innermost first hollow space such that said second spaces and said radially innermost first spaces communicate respectively with one another, said channel means extending from outside the web plate means to said second spaces, wherein each of said second spaces is connected with a separate channel forming part of said channel means for communicating cooling air from the cooling air supply means to the respective second space, and wherein the cross-sectional area of each of the respective channels is substantially less than the cross-sectional area of the respective second space connected therewith.