Non-line of sight electro discharge machined part

Patent metadata

Field	Value
Publication number	US-9561555-B2
Application number	US-201213729286-A
Country	US
Kind code	B2
Filing date	Dec 28, 2012
Priority date	Dec 28, 2012
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

A method of machining cooling holes in a component includes the steps of inserting an electro discharge machining guide that houses an electrode into an internal cavity of a component, and machining a cooling hole into a wall of the component with the electrode. A gas turbine engine component includes first and second spaced apart walls providing an internal cavity. The first wall has outer and inner surfaces. The inner surface faces the internal cavity. A cooling hole extends through the first wall from the inner surface to the outer surface. The cooling hole includes entry and exit openings respectively provided in the inner and outer surfaces. The exit opening includes a cross-sectional area that is smaller than a cross-sectional area of the entry opening.

First claim

What is claimed is:

1. A method of machining cooling holes in a component comprising the steps of:
inserting an electro discharge machining guide that houses an electrode into an internal cavity of a component;
machining a cooling hole into a wall of the component with the electrode; and
applying a non-conductive thermal barrier coating on the wall on a surface opposite the internal cavity, the applying step performed before the machining step.

2. The method according to claim 1 , wherein the guide includes first and second portions that are non-colinear with respect to one another.

3. The method according to claim 1 , wherein the component includes an airfoil, and the internal cavity is a cooling passage within the airfoil.

4. The method according to claim 3 , wherein the component is a turbine stator vane.

5. The method according to claim 4 , wherein the turbine stator vane is a doublet.

6. The method according to claim 1 , wherein the wall is obstructed by a structure on a side opposite the internal cavity.

Assignees

• United Technologies Corp

Inventors

• Koonankeil James M
• Pietraszkiewicz Edward F
• Schachtner Karl A
• Klinefelter Kevin J
• Fritch Markus W
• Daley Jason

Classifications

• Y10T29/49323

  Assembling fluid flow directing devices, e.g., stators, diaphragms, nozzles · CPC title

• B23H1/00 Primary

  Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric · CPC title

• B23H9/10

  Working turbine blades or nozzles · CPC title

• F05D2240/81

  Cooled platforms · CPC title

• B23H7/30

  Moving electrode in the feed direction (B23H7/32 takes precedence) · CPC title