Patent ID: 7517195

Claim:
A closure bucket group for mounting on a dovetail of a turbine wheel, comprising: a leading bucket with a leading bucket rear side, the leading bucket rear side comprising a pair of leading bucket outer flat portions, each leading bucket outer flat portion forming a leading bucket angle with an axis of the turbine wheel; a closure bucket with a closure bucket front side and a closure bucket rear side, each of the closure bucket front side and the closure bucket rear side comprising a pair of closure bucket outer flat portions, each closure bucket outer flat portion forming a closure bucket angle with the wheel axis; a trailing bucket with a trailing bucket front side, the trailing bucket front side comprising a pair of trailing bucket outer flat portions, each trailing bucket outer flat portion forming a trailing bucket angle with the wheel axis; wherein the leading bucket rear side and the closure bucket front side define a first enclosed keyway and wherein the closure bucket rear side and the trailing bucket front side define a second enclosed keyway; and a plurality of keys positioned within the first enclosed keyway and the second enclosed keyway.