General Electric Company

Daniel Randolph Trembley

Mark Edward Burnett

Maurice David Fournier

Steam turbine buckets have radially projecting tenons received in openings of covers. The covers are provided with a profiled surface, with recesses or radially outwardly projecting teeth, or both, to form a gap between the cover and a stationary component having increased pressure drop with resulting decreased leakage flow and reduced potential for solid particle erosion. In the profiled cover surface, the outer surface of the tenon and outer surface of the cover are machined to form the recesses or teeth, affording a flush cover/tenon design with improved sealing efficiencies and reduced solid particle erosion.

Flush tenon cover for steam turbine blades with advanced sealing

A bucket cover to be attached to the tip of a turbine bucket has an aperture with an engageable geometry for receiving a tenon extending from the bucket and retaining the bucket cover to the bucket. The cover has an outer planar surface, an inner planar surface to abut against the bucket and an aperture extending between its surfaces. The aperture is defined by a sidewall that has multiple surfaces of varying cross-sectional size so as to structurally engage a tenon that is deformed during assembly. The sidewall of the aperture has a concave curved portion adjacent the outer planar surface leading to a narrow throat portion that corresponds generally to the size and shape of an undeformed tenon. In a method of making a turbine blade attached to a bucket cover, after a tenon is received in the aperture, the tenon is deformed by application of compressive force so that the tenon fills the aperture of the cover. The deformed tenon engages the various surfaces of the aperture sidewall to secure the cover on the bucket. The button head that is formed on the outer planar surface of the cover by excess tenon material is removed along with a thin layer of the outer planar surface of the bucket in order to provide a smooth, flush outer surface.

Growing community of inventors

Old Town, ME, United States of America

Daniel Randolph Trembley