Method for the production of coated turbine moving blades and moving-blade ring for a rotor of an axial-throughflow turbine
View Patent ↗A method for producing a coated turbine blade, with which the frequency property thereof can be particularly easily adjusted to the required boundary conditions is provided. Recesses are introduced into a blade tip of the blade leaf of the turbine blade after coating of turbine blade. In one aspect a plurality of bores are made which are distributed along the blade leaf center line.
1. A method for the production of a coated turbine moving blade, comprising:
coating a turbine moving blade with a protective layer; and
introducing a plurality of recesses into a blade tip of a blade leaf of the turbine moving blade, wherein the number and depth of the recesses are configured to compensate a shift in characteristic frequency of the turbine moving blade produced by a mass of the protective layer,
wherein the introduction of the plurality of recesses occurs after the coating of the turbine moving blade,
wherein each of the plurality of recesses is a hole which is drilled into the blade tip in a direction of a blade foot of the turbine moving blade, and
wherein the plurality of recesses are distributed along a center line of the blade leaf, the center line running centrally from a leading edge to a trailing edge of the blade leaf.
2. The method as claimed in claim 1 , further comprising superficially closing the drilled recesses.
3. The method as claimed in claim 2 , wherein the plurality of recesses are closed using a plug or solder, whereby each recess is partially filled up leaving a cavity.
4. The method as claimed in claim 1 , wherein a drill depth is to 50% of a radial extent of the blade leaf with respect to an installation position of the turbine moving blade.
5. The method as claimed in claim 1 , wherein prior to the step of coating, an existing coating is removed from the turbine moving blade.
6. The method as claimed in claim 1 , wherein the protective layer comprises a corrosion protection layer and/or a heat insulation layer.
7. A method for the production of a coated turbine moving blade, comprising:
coating a turbine moving blade with a protective layer; and
introducing a plurality of recesses into a blade tip of a blade leaf of the turbine moving blade, wherein the number and depth of the recesses are configured to compensate a shift in characteristic frequency of the turbine moving blade produced by a mass of the protective layer,
wherein the introduction of the plurality of recesses occurs after the coating of the turbine moving blade,
wherein each of the plurality of recesses is a hole which is drilled into the blade tip in a direction of a blade foot of the turbine moving blade, and
wherein the plurality of recesses are distributed laterally with respect to a center line of the blade leaf, the center line running centrally from a leading edge to a trailing edge of the blade leaf.
8. The method as claimed in claim 7 , further comprising superficially closing the drilled recesses.
9. The method as claimed in claim 8 , wherein the plurality of recesses are closed using a plug or solder, whereby each recess is partially filled up leaving a cavity.
10. The method as claimed in claim 7 , wherein the method is performed on a turbine moving blade having an internally coolable blade leaf.
11. The method as claimed in claim 7 , wherein the plurality of recesses are made in a region of a trailing edge of the turbine moving blade where a suction-side pressure wall meets a delivery-side pressure wall.
12. The method as claimed in claim 7 , wherein a drill depth is to 50% of a radial extent of the blade leaf with respect to an installation position of the turbine moving blade.
13. The method as claimed in claim 7 , wherein prior to the step of coating, an existing coating is removed from the turbine moving blade.
14. The method as claimed in claim 7 , wherein the protective layer comprises a corrosion protection layer and/or a heat insulation layer.