METHOD FOR ELECTRO-CHEMICAL MACHINING TURBINE WHEEL IN-SITU

• US 20160279722A1
• Filed: 03/27/2015
• Published: 09/29/2016
• Est. Priority Date: 03/27/2015
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Capriotti, Daryl Paul, Smith, Michael Alan, Herbold, John William, Holmes, James Bradford, Trimmer, Andrew Lee
• Granted Patent: US 9,943,920 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23H 11/003 Mounting of workpieces, e.g. working-tables
• CPC Class Codes: B23H 3/04 Electrodes specially adapted therefor or their manufacture B23H9/00 takes precedence
• CPC Class Codes: B23H 7/26 Apparatus for moving or positioning electrode relatively to workpiece; Mounting of electrode
• CPC Class Codes: B23H 9/10 Working turbine blades or nozzles
• CPC Class Codes: F01D 25/285 Temporary support structures, e.g. for testing, assembling, installing, repairing; Assembly methods using such structures
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F01D 5/12 Blades specially adapted for radial flow machines or engines F01D5/04; blade roots F01D5/30; rotors with blades adjustable in operation F01D7/00; stator blades F01D9/02
• CPC Class Codes: F01D 5/3007 of axial insertion type
• CPC Class Codes: F05D 2230/11 by electrochemical methods
• CPC Class Codes: F05D 2230/80 Repairing, retrofitting or upgrading methods

Abstract

A method for electro-chemical machining (ECM) is provided. Methods may include providing an ECM machine including a controller and a fixture configured for positioning an electrode for ECM, positioning the fixture in a selected dovetail slot of a plurality of dovetail slots in a turbine wheel, the turbine wheel being positioned in-situ in a turbomachine, the fixture positioning the electrode for ECM of a portion of the selected dovetail slot, applying an electrolyte solution between the selected dovetail slot and the electrode, and removing material from the portion of the selected dovetail slot by applying an electric potential to the electrode to create a potential gradient between the electrode and the portion of the selected dovetail slot. The machining may be repeated for each dovetail slot of the turbine wheel in-situ in the turbomachine.

Claims

1. A method for electro-chemical machining (ECM), comprising:

providing an ECM machine including a controller and a fixture configured for positioning an electrode for ECM;

positioning the fixture in a selected dovetail slot of a plurality of dovetail slots in a turbine wheel, the turbine wheel being positioned in-situ in a turbomachine, the fixture positioning the electrode for ECM of a portion of the selected dovetail slot;

applying an electrolyte solution between the selected dovetail slot and the electrode; and

removing material from the portion of the selected dovetail slot by applying an electric potential to the electrode to create a potential gradient between the electrode and the portion of the selected dovetail slot.

2. The method of claim 1, further comprising:

removing the fixture from the selected dovetail slot; and

repeating the positioning, applying and the removing for each dovetail slot of the plurality of dovetail slots.

3. The method of claim 1, wherein the fixture visually obstructs the ECM in the selected dovetail slot.

4. The method of claim 1, wherein the portion of the selected dovetail slot includes an edge of a cooling slot within the selected dovetail slot.