US 4,028,788 AGranted

Method of refurbishing turbine blade air seal flanges

OwnerRalph T. DeMusisinventor

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Abstract

A method of refurbishing the air seal flanges of turbine blades which have become worn, comprising the steps of adding a bead of welding material to the opposite side portions and the edge portions of the flange so as to build up those areas which have been worn away, and thereafter removing controlled amounts of the built up areas so as to restore the piece to its original geometry. In the latter step, the blade is clamped in a first machine having a pair of abrasive belts and a pair of pivotally mounted pressure shoes engageable with the backs of the belts respectively, such that their abrasive surfaces can be brought into engagement with the opposite sides of the air seal flanges. Controlled quantities of the built-up flange can be removed, depending on the degree of advancement of the shoes. In another machine, the blade is placed on a slide which approaches an abrasive belt backed by a special curved contour shoe, whereby as the edge of the seal engages the abrasive surface of the belt, the latter yields an extent, conforming to the particular contour of the shoe. This has the effect of imparting a predetermined, desired profile to the flange. Following the welding and refinishing operations, the geometry and physical characteristics of the refurbished blade closely resemble those of a new blade. By the above method, considerably less expense is entailed over that involved with discarding the old blades and fabricating new ones.

Claims2

Dependent claims

The method of refurbishing the elongate air seal flanges of worn turbine blades, which includes the steps of:

a. adding a bead of welding material to worn areas of the air seal flange of a blade so as to build up portions thereof which have been worn away, and thereafter in a machine having a work-performing station, a power driven abrasive belt adjacent the station and a contoured back-up shoe having a planar front surface containing an elongate recess characterized by a curved surface with a profile resembling that of the original geometry of the air seal flange of a turbine blade but of greater length than said flange whereby portions of the belt occupying said recess can have a length in excess of the length of the air seal flange, said shoe being engageable with the back of the belt such that the latter can yield and conform to the profile when its abrasive surface is engaged by a workpiece, and having a slide advanceable toward the work-performing station, the steps of:
b. clamping the blade onto said slide, with its air seal flange facing said work-performing station and extending substantially parallel to that portion of the belt at said station, and
c. advancing the slide and blade a sufficient distance toward the work-performing station to cause the edge of the air seal flange to engage the abrasive surface of said belt and force the latter to yield an extent and conform to the particular curved profile of the recess in the back-up shoe while it removes a portion of the welded material, thereby to restore the flange edge to its original curved geometry closely resembling the curved profile of the recess of said back-up shoe,
d. the advance of the slide and blade being sufficiently large to bring the foremost edge of the flange of the blade into the recess of the back-up shoe and past the planar front surface thereof.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 05/648,388Filed 12 Jan 1976
Granted: 14 Jun 1977
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B24B 21/165
For grinding other surfaces of particular shape: for vanes or blades of turbines, propellers, impellers, compressors and the like
B23P 6/007
Repairing turbine components, e.g. moving or stationary blades, rotors,: using only additive methods, e.g. build-up welding
B23P 15/04
Making specific metal objects by operations not covered by a single other subclass or a group in this subclass: turbine or like blades from…
F01D 5/005
Blades; Blade-carrying members ; Heating, heat-insulating, cooling or antivibration means on the blades or the members: repairing methods or devices