Patent Application
20140001158
This invention relates generally to systems and methods for repairing components disposed within cases. More particularly, this invention relates to systems and methods for repairing gas turbine engine components.
Gas turbine engine components, such as blades and vanes are critical for safe operation of gas turbine engines. Such gas turbine engine components are typically made from expensive superalloy materials, such as nickel-based superalloy materials to endure high temperatures and high pressures in operation.
After extended service and/or during manufacturing, the gas turbine engine components may have defects caused by effects, such as corrosion, rub cracks, pitting, and foreign objects. As it is difficult and expensive to manufacture the gas turbine engine components, repair of the components are desirable so as to prevent tip liberation and subsequent component failure.
There have been various attempts to repair gas turbine engine components. For example, grinding operations may be employed. However, since gas turbine engine components are generally enclosed in an engine case, typically the engine case may need to be removed to facilitate the repair of the components, which is time consuming. In addition, removal of the engine case for repair of the components also causes undesirable outage time, which adds to the overall cost of the rep air.
Therefore, there is a need for new and improved systems and methods for repairing gas turbine engine components, such as blades and vanes, that are more cost-effective, while still ensuring safe operation of the gas turbine engines.
A system for repairing a component is provided. The system includes an electrochemical machining unit and a tool delivery apparatus. The electrochemical machining unit includes an electrode configured to machine the component, a power supply configured to energize the electrode and the component with opposite electrical polarities, and a machining solution source configured to pass a machining solution between the component and the electrode. The tool delivery apparatus includes a plurality of linkage elements pivotally connected and configured to carry the electrode. The tool delivery apparatus further includes an actuation element configured to actuate the linkage elements to move the electrode.
A tool delivery apparatus is provided. The tool delivery apparatus includes a first, a second and a third linkage element pivotally connected. The second linkage element is disposed between the first and third linkage elements and configured to carry an electrode for electrochemical machining The tool delivery apparatus further includes an actuation element configured to move the second linkage element so as to move the electrode.
A method for repairing a component disposed within a case is provided. The method includes providing a number of linkage elements pivotally connected and carrying an electrode; providing an actuation element to actuate the linkage elements to move the electrode; and passing an electric current between the electrode and the component while passing a machining solution therebetween to perform electrochemical machining for repairing the component.
The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:
Preferred embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail.
The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The modifier “about” used in connection with a quantity is inclusive of the stated value, and has the meaning dictated by context, (e.g., includes the degree of error associated with measurement of the particular quantity).
Moreover, in this specification, the suffix “(s)” is usually intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., “the element” may include one or more elements, unless otherwise specified). Reference throughout the specification to “one embodiment,” “another embodiment,” “an embodiment,” and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. Similarly, reference to “a particular configuration” means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the configuration is included in at least one configuration described herein, and may or may not be present in other configurations. In addition, it is to be understood that the described inventive features may be combined in any suitable manner in the various embodiments and configurations.
Non-limiting examples of the machine 100 includes a gas turbine, a steam turbine, a compressor, or other suitable machines. For the illustrated arrangement, the machine 100 comprises a compressor. For the illustrated example, the component 101 may comprise a blade and/or a vane in the compressor.
The machine 100, such as the compressor may be formed with alternating stages of rotor airfoils or blades and stator airfoils or vanes. The system 10 is configured to perform repair of the component, such as blade(s) in all of the stages of the compressor 100 without removal of the case 102. Further, the system 10 is configured to perform repair of the component, such as vane(s) in the compressor 100. Based on different stages of the target blades and/or vanes, positions of the system 10 relative to the compressor 100 may be easily positioned to reach the target blades and/or vanes.
For example, the system 10 extends into the compressor 100 to repair the target blades and/or vanes 101 through an opening, such as a borescope port 104 defined on the case 102. For particular applications, the system 10 is further configured to reach both leading edges and trailing edges of the target blades and/or vanes for repair operations.
The ECM unit 11 is configured to perform repair of the component 101. Typically, the ECM unit 11 is configured to remove material from the component 101 to form desired features with desired shapes on the component 101 to perform the repair. Depending on the specific application, the ECM unit 11 may be configured to deposit material on the component 101.
For the illustrated arrangement, the ECM unit 11 comprises an electrode 13, a power supply 14, and a machining solution source 15. It should be noted that the arrangement of the ECM unit 11 is merely illustrative to show the operation of the electrochemical machining Some elements are not illustrated. For example, a controller (not shown) may be deployed to control the power supply 14 and/or the machining solution source 15 to provide desired electric power and a machining solution, respectively.
The power supply 14 is configured to energize the electrode 13 and the component 101 with opposite electrical polarities. In this example, the electrode 13 and the component 101 are connected to negative and positive poles of the power supply 14 respectively, so that the electrode 11 functions as a cathode and the component 101 acts as an anode in this example. The machining solution source 15 is configured to pass the machining solution, such as an electrolyte through a gap (not labeled) between the electrode 13 and the component 101.
In non-limiting examples, the electrolyte from the machining solution source 15 may comprise an organic electrolyte including, but not limited to ethylene glycol with a halide salt doping. In one example, the halide salt comprises sodium chloride. Additionally, a pump (not shown) may be connected to the machining solution source 15 for controlling the pressure and the flow rate of the machining solution.
Thus, in operation, the electrode 13 moves toward the component 101 but without touching the component 101. The power supply 14 applies a potential gradient and passes an electric current between the electrode 13 and the component 101. The electrolyte from the machining solution source 15 is injected to an area being repaired on the component 101. As the electrolyte passes through the gap between the electrode 13 and the component 101, material from the component 101 is dissolved and removed. The electrode 13 is guided along desired paths to form the desired features in the component 101. In non-limiting examples, the electrode 13 may perform certain repair, such as edge blending or tip cropping on the compressor 101.
In certain applications, the system 10 may or may not comprise a collecting apparatus (not shown) extending into the compressor 101 to collect the machining solution during the repair operation for recovery and circulation. Depending on the specific application, the collecting apparatus may extend into the compressor 101 through the borescope port 104, another borescope port (not shown) adjacent to the borescope port 104, or a bell mouth (not shown) of the compressor 101.
The tool delivery apparatus 12 is configured to deliver or carry the electrode 13 into the compressor 100 to perform the repair, for example, through the case 102 prior to repairing the component 101 and to withdraw the electrode 13 from the case 102 after repairing the component 101. In the illustrated example, the tool delivery apparatus 12 comprises a linkage-based mechanism. Depending on the specific application, the configurations of the linkage-based mechanism may vary. For the example arrangement, as illustrated in
For the example arrangement, as depicted in
In the illustrated example in
For the illustrated arrangements, the second linkage element 18 is disposed between the first and third linkage elements 17, 19. The first and second rotating joints 20, 21 connect respective distal ends (not labeled) of the first and second linkage elements 17, 18, and the second and third linkage elements 18, 19, so that the first, second and third linkage elements 17-19 moves pivotally from each other.
The actuation element 16 is pivotally connected with a free end (not labeled) of the third linkage element 19 with a distal end thereof via the third rotating joint 22. In non-limiting examples, the first, second and third rotating joints 20-22 may comprise revolute joints each providing a single-axis rotation function. The actuation element 16 is further connected with the first linkage element 17 through a linear joint 23 (shown in
In some examples, the linear joint 23 may be a prismatic joint. For example, as illustrated in
The first, second and third linkage elements 17-19 may have any suitable shapes, such as polygonal or cylindrical shapes. As depicted in
For the illustrated arrangements in
In non-limiting examples, the electrode 13 may be hollow along a length thereof. During the electrochemical machining, in order to facilitate circulation of the electrolyte, each of the first and second linkage elements 17-18 may be hollow and defines a respective inner channel 26, 27 in fluid communication with the machining solution source 15 and the electrode 13 to deliver the electrolyte to pass through the gap between the electrode 13 and the component 101. In other examples, the electrolyte may not be delivered by the first and/or second linkage elements 17-18.
Further, the electrode 13 defines a number of channels 29 passing through a sidewall (not labeled) thereof and in fluid communication with the inner passageway 28 of the electrode 13. Thus, the electrolyte from the inner passageway 28 passes through the channels 29 and through the gap between the electrode 13 and the component 101 to perform the repair. For the illustrated arrangement, the inner passageway 28 is a blind hole to facilitate the passage of the electrolyte through the channels 29.
The arrangements in
Additionally, for the arrangement shown in
In some applications, an electrical connection 33 (shown in
In this example, another tool delivery apparatus (not shown) similar to the tool delivery apparatus 12 may be employed to deliver the electrical connection 34 into the compressor 101 to provide the electrical connection. Alternatively, any other suitable techniques may be employed to provide the electrical connection between the power supply 14 and the component 101.
For some arrangements, the third linkage element 19 may or may not define an inner channel. In certain applications, a portion of the third linkage element 19 adjacent to the second one 21 of the rotating joints may define a receiving slot 35 to receive a portion of the electrode 13, so that when the tool delivery apparatus 12 is configured as the straight line, the portion of the electrode 13 is accommodated into the receiving slot 35. Additionally, one or more miniature cameras 36 may also be disposed on the third linkage element 19 to monitor the circumstances within the compressor 101, for example to monitor the repair operation by the electrode 13.
Accordingly, during the repair operation, as illustrated in
After the tool delivery apparatus 12 reaches a desired position, the actuation element 16 moves upward linearly along the first linkage element 17 and actuates the end of the third linkage element 19 connected with the actuation element 16 to move upwardly through the third one 22 of the rotating joints. In certain applications, in order to control the direction of movement of the third linkage element 19, the third rotating joint 22 includes an off-center joint. Additionally, other suitable mechanisms may also be used to control the movement of the third linkage element 19.
Further, in operation, the end of the third linkage element 19 connected with the second linkage element 18 deviates from its original position and moves away from the first linkage element 17 to drive the second linkage element 18 carrying the electrode 13 moves upwardly along an arc curve to a desired position through the first and second rotating joints 20-21.
In non-limiting examples, the second linkage element 18 may move to a position where the angle between the first and second linkage elements is about 90°. In other examples, the angle between the first and second linkage elements may be in a range of about 0° and to about 180°. Subsequently, when the second linkage element 18 carrying the electrode 13 is in position, the ECM unit 11 starts to perform the electrochemical machining for repair.
After finishing the repair, the actuation element 16 moves downwardly along the first linkage element 17 to actuate the second and third linkage elements 18-19 move towards the first linkage element 17 through the first, second and third rotating joints 20-22 until the tool delivery apparatus 12 returns to its original configuration, for example, a straight line configuration. During this process, the ends of the second and third linkage elements 18-19 adjacent to the second rotating joint 21 moves towards and away from the actuation element. Finally, the tool delivery apparatus 12 moves upwardly out of the compressor 100 through the borescope port 104 of the case 102.
In some embodiments, during repair, the first linkage element 17 may be controlled manually to move up and down and/or rotate so as to move the tool delivery apparatus 12 linearly and/or rotationally to a desired position in the compressor 101. In certain applications, as illustrated in
For some arrangements, the first, second and third linkage elements 17-19 and the actuation element 16 may be rigid to perform the repair. Alternatively, one or more of the first, second and third linkage elements 17-19 and the actuation element 16 may be flexible. For example, two linkage elements, such as the first and second linkage elements 17-18 may be employed to perform the repair. The actuation element 16 may be flexible to drive the second linkage element 18 carrying the electrode 13 to move in position.
Beneficially, the system 10 employs the ECM unit 11 to perform the repair to improve the repair efficiency and reduce downtime of the compressor 100. Further, the system 10 employs the linkage-based tool delivery apparatus 12 configured to repair the component 101 in one or more the blades and the vanes of the compressor 100 and to carry the electrode 13 into the compressor 100 through the opening, such as the borescope port 104 of the case 102. In addition, the tool delivery apparatus 12 employs the linkage elements 17-19 and the actuation element 16 to cooperate to move the electrode 13 in position to perform the repair. Beneficially, the tool delivery apparatus 12 has a relatively simple structure, and adjusts configurations depending on the specific application. This beneficially increases the flexibility of the system 10.
While the disclosure has been illustrated and described in typical embodiments, it is not intended to be limited to the details shown, since various modifications and substitutions can be made without departing in any way from the spirit of the present disclosure. As such, further modifications and equivalents of the disclosure herein disclosed may occur to persons skilled in the art using no more than routine experimentation, and all such modifications and equivalents are believed to be within the spirit and scope of the disclosure as defined by the following claims.
