Methods for automated peening of tenons connecting turbine buckets and cover plates

Apparatus for securing a cover plate and tips of adjacent buckets of a turbine wheel to one another wherein the cover plate has a tenon projecting from each of the opposite sides thereof and through an opening formed in the respective tips of adjacent first and second buckets, comprising:

• a fixture having a plurality of discrete, generally parallel, surfaces offset from one another for registration with side faces of the adjacent first and second bucket tips and locating the cover plate and the first and second bucket tips relative to the fixture;
• a peening head having a tool spaced from said fixture for peening an end of a tenon projecting from an opposite side of the over plate and through an opening in the tip of a second bucket adjacent to and lying on said opposite side of the cover plate from the first bucket tip.

In an apparatus including a fixture having a surface for registration with a side face of a first bucket tip of a first bucket and a guide for locating the first bucket tip and surface relative to one another, said surface lying in opposition to a peening tool for peening end portions of a tenon projecting from one side of a cover plate through an opening in a second tip of a second bucket adjacent the first bucket wherein the cover plate lies between first and second tips of the first and second buckets, respectively, a method of securing the cover plate between the first and second buckets, comprising:

• (a) locating the tip of said first bucket in opposition to the fixture surface utilizing the guide to locate the fixture surface and the tip of the first bucket and the cover plate relative to one another;
• and
• (b) peening a tip portion of the tenon projecting from the one side of the cover plate through the opening in the second tip of the second bucket by engaging the peening tool and the tenon tip to secure the cover plate and the second bucket to one another.