METHOD OF FORMING COOLING HOLES AND TURBINE AIRFOIL WITH HYBRID-FORMED COOLING HOLES
First Claim
1. A method of forming a cooling hole in a workpiece, comprising the steps of laser-forming a blind, inwardly-tapering transition opening into a first side of the workpiece, and EDM-forming a generally cylindrical through hole to a second, opposing side of the workpiece communicating with the inwardly-tapering transition opening to form a through cooling hole communicating with the first and second sides of the workpiece.
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Accused Products
Abstract
A method of forming a cooling hole in a workpiece that includes the steps of laser-forming a blind, inwardly-tapering transition opening into a first side of the workpiece, and EDM-forming a generally cylindrical through hole to a second, opposing side of the workpiece communicating with the inwardly-tapering transition opening to form a through cooling hole communicating with the first and second sides of the workpiece. An airfoil having cooling holes formed by use of both laser and EDM is also disclosed.
59 Citations
13 Claims
- 1. A method of forming a cooling hole in a workpiece, comprising the steps of laser-forming a blind, inwardly-tapering transition opening into a first side of the workpiece, and EDM-forming a generally cylindrical through hole to a second, opposing side of the workpiece communicating with the inwardly-tapering transition opening to form a through cooling hole communicating with the first and second sides of the workpiece.
- 7. A method of forming a plurality of cooling holes in a turbine airfoil of the type having a leading edge and an axially spaced-part trailing edge, the leading edge having an axially-extending aerodynamic external surface curvature, a root and a tip spaced-apart along a radially-extending span axis, a pressure sidewall and a laterally-spaced-apart suction sidewall, a cooling circuit positioned between the pressure sidewall and the suction sidewall for channeling a fluid flow for cooling the airfoil, comprising the steps of laser-forming a plurality of blind, inwardly-tapering diffuser sections into a first side of the workpiece, and EDM-forming a generally cylindrical through metering section to a second, opposing side of the workpiece communicating with the inwardly-tapering transition opening to form a through cooling hole communicating with the first and second sides of the workpiece.
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11. An airfoil, comprising:
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(a) a leading edge and an axially spaced-part trailing edge, the leading edge having an axially-extending external surface curvature; (b) a root and a tip spaced-apart along a radially-extending span axis; (c) a pressure sidewall and a laterally-spaced-apart suction sidewall; (d) a cooling circuit positioned between the pressure sidewall and the suction sidewall for channeling a fluid flow for cooling the airfoil; (e) a plurality of cooling holes formed in the leading edge along the span axis of the airfoil in fluid communication with the cooling circuit, at least some of the cooling holes having a diffuser section communicating with the leading edge surface, the diffuser section having opposed walls defining an exit opening on the surface of the leading edge and a respective cylindrical metering section positioned between and communicating with the interior of the airfoil and the diffuser section, wherein the diffuser section is formed by laser and the cylindrical metering section is formed by EDM. - View Dependent Claims (12, 13)
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Specification