METHOD OF STRENGTHENING SURFACE OF UPPER PART OF TURBINE BLADE FEATHER Russian patent published in 2007 - IPC F01D5/28 

FIELD: mechanical engineering; turbines.

SUBSTANCE: according to proposed method of strengthening upper part of turbine blade feather, protective cover plates made of high erosion resistant material are installed on leading edge of upper part of blade feather. Surface of blade back adjoining protective cover plates and section of leading below cover plates are strengthened. Recess of width from 0.06 to 0.18 of length of blade profile chord is preliminarily made from side of blade back along leading edge starting from point of maximum curvature of profile on blade leading edge. Chord is shortened by value from 0.015 to 0.025 of its initial length starting from point of maximum curvature of profile on blade leading edge. Depth of recess on blade back is made from 0.16 to 0.31 maximum thickness of blade profile. Protective cover plates are tightly fitted in recess and are rigidly secured by welding. Each cover plate is made to correspond to form and geometrical dimensions of corresponding mounting section of blade profile removed by cutting out to form recess. Width and length of surface of blade back adjoining protective cover plates and section of leading edge below cover plates to be strengthened are taken not less than 0.15 and not less than 1.045 of length of chord of blade profile and of length of section of leading edge, respectively, on which protective cover plates are mounted. Invention relates to turbine building, namely, to design of turbine blades, and it can be used for strengthening surface of upper part of feather of turbine blades as method of erosion protection. According of invention recess 3 of depth from 0.16 to 0.31 of maximum thickness of blade profile and width of 0.06-0.18 of length of chord of blade profile is made in material of blade 1 from side of back along leading edge 2. Simultaneously, chord is shortened by 0.015 to 0.025 of its initial length. Protective cover plates 4 made of material of high erosion resistance are tightly fitted in recess 3 and secured by welding. Surface 5 of back of blade 1 adjoining protective cover plates 4 and section of leading edge below cover plates are strengthened by electric spark alloying. Width and length of surface 5 of back of blade 1 is taken not less than 0.15 and not less than 1.045, respectively, of length of chord of blade profile and of length of section of leading edge on which protective cover plates are mounted.

EFFECT: improved reliability of strengthening of surface of upper part of turbine blade feather against erosion without affecting aerodynamic characteristics of blade.

2 cl, 2 dwg