Method and apparatus for repairing turbine components

• US 20080173624A1
• Filed: 01/17/2008
• Published: 07/24/2008
• Est. Priority Date: 01/19/2007
• Status: Active Grant

• Current Assignee: Optomec, Inc.
• Original Assignee: S E Huffman Corporation
• Inventors: Humber, J. Michael, Cobb, James N., Drechsler, David E.
• Granted Patent: US 8,140,179 B2
• Time in Patent Office: Days
• US Class Current: 219/125.1
• CPC Class Codes: B22F 10/25 Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS]
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/003 Apparatus, e.g. furnaces in general F27B
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B23K 35/0244 Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23P 6/007 using only additive methods, e.g. build-up welding
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: Y02P 10/25 Process efficiency
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling

Abstract

The present invention includes an apparatus and method by which the three-dimensional form or configuration of a distorted workpiece, such as a turbine component, is reverse engineered, and then this reverse engineering capability is combined with welding equipment, preferably a laser powder fusion welder, all integrally carried within a single machine, whereby a tool path unique to each workpiece is created and the welding machine accurately replaces lost material on the workpiece. The present invention consists of a series of operations or steps, preferably carried out by a single machine.

Claims

1. A method for repairing distorted turbine components, which includes:

(a) creating an initial digitizing path that generally represents the geometry of the component in its original configuration;

(b) moving a digitizing device along the initial digitizing path to generate digitized data that represents the geometry of the distorted component;

(c) utilizing a computer-based template which includes information that conforms to the shape of the component in its original form and which includes associated weld processing parameters, and inputting the digitized data into the computer-based template to create an updated template;

(d) utilizing the updated template to create a tool path for a welding machine to follow along the geometry of the distorted component and to set the associated weld processing parameters; and

(e) repairing the distorted component by moving the welding machine along the tool path and applying a weld to the distorted component using the associated weld processing parameters.

2. A method for repairing turbine components as defined in claim 1, wherein the step of digitizing the distorted component includes using a digitizing device to digitize predetermined points along the surface of the distorted component, and wherein the predetermined digitized points are utilized to create the tool path.

3. A method for repairing turbine components as defined in claim 1, wherein the digitizing device digitizes at least two predetermined digitized points along the surface of the distorted component.

4. A method for repairing turbine components as defined in claim 3, wherein the distorted turbine component includes two radially extending side walls spaced from one another and having an edge portion extending between the spaced walls, and wherein the digitizing device probes a plurality of sets of at least two radially spaced points on each of the side walls that define a vector which represents the configuration of the side walls, and wherein the tool path is created along points between the sets of vectors.

5. A method for repairing turbine components as defined in claim 1, wherein the digitizing device is a touch probe.

6. A method for repairing turbine components as defined in claim 1, wherein the step of creating an initial digitizing path includes using a CAD model of the geometry of the component in its original configuration.

7. A method for repairing turbine components as defined in claim 1, wherein the step of creating an initial digitizing path includes creating a hard coded program using manually input welding machine coordinates that reflect the geometry of the component in its original configuration.

8. A method for repairing turbine components as defined in claim 1, wherein the method includes the steps of gathering feedback information relating to one or more characteristics of the weld as it is being formed on the turbine component, comparing the feedback information to a predetermined welding model, and varying the associated welding parameters to correct variances between the feedback information and the predetermined welding model.

9. A method for repairing distorted turbine components using a welding machine that is provided with a work table for holding the turbine component, a digitizing device, a welding head, and a computerized control system for controlling the movement of the work table, the digitizing device and the welding head, such method including the steps of:

(a) operating the welding machine to move the digitizing device relative to the distorted turbine component to digitize the walls of the distorted component and create digitized data that generally represents the three dimensional geometry of the distorted component;

(b) utilizing the digitized data to cause the control system to create a tool path for the welding head to follow so that it moves along the actual geometry of the distorted component;

(c) programming the welding machine control system to use associated welding parameters; and

(d) repairing the distorted component by moving the welding head along the tool path and applying a weld to the distorted component.

10. A method for repairing turbine components as defined in claim 9, wherein the step of probing the distorted component includes using a digitizing probe to probe predetermined points along the surface of the distorted component, and wherein the probe points are utilized to create the tool path.

11. A method for repairing turbine components as defined in claim 10, wherein the distorted turbine component includes two radially extending side walls spaced from one another and having an edge portion extending between the spaced walls, and wherein the touch probe probes a plurality of sets of at least two radially spaced points on each of the side walls that define a vector which represents the configuration of the side walls, and wherein the tool path is created along points between the sets of vectors to follow the geometric configuration of the edge portion of the turbine component.

12. A method for repairing turbine components as defined in claim 10, wherein the turbine component is a turbine blade.

13. A method for repairing turbine components as defined in claim 11, wherein the digitizing device is a touch probe.

14. A machine for repairing turbine components which includes:

(a) a frame;

(b) a digitizing device mounted on the frame for digitizing the surfaces of the turbine component and generating electronic signals determined by the configuration of the surfaces of the turbine component;

(c) a welding head mounted on the frame;

(d) a movable work table carried by the frame adjacent the digitizing device and the welding head, the work table including a support on which a turbine component can be mounted;

(e) motion control motors for moving the work table relative to the digitizing device about a plurality of axes to selectively vary the position of the turbine component relative to the digitizing device and the welding head whereby the digitizing device can digitize a plurality of points at predetermined locations on the surface of the turbine component and for moving the work table relative to the welding head whereby the turbine component can be welded by the welding head; and

(f) a computerized control system for the welding machine which;

(i) controls the motion control motors to move the work table relative to the digitizing device to position the turbine component so that predetermined points along the surfaces of the turbine component can be probed at a plurality of predetermined positions and generate the electronic signals at such positions;

(ii) receives the electronic signals from the digitizing and creates a tool path that follows the configuration of the turbine component utilizing such signals;

(iii) controls the motion control motors to move the welding head relative to the welding head along the tool path; and

(iv) operates the welding machine in accordance with a set of associated welding parameters to weld the surfaces of the turbine component.

15. A machine for repairing turbine components as defined in claim 14, wherein the digitizing device is a touch probe.

16. A machine for repairing turbine components as defined in claim 14, wherein an information feed back device is mounted on the frame adjacent the welding head for gathering feedback information regarding one or more characteristics of the weld on the turbine component as the weld is being made by the welding head, wherein the feedback information is fed back to the computerized control system, and wherein the computerized control system compares the feedback information with a predetermined welding model and varies one or more of the associated welding parameters to correct variances between the feedback information and the predetermined welding model.