The subject matter disclosed herein relates to systems and methods for turbine repair and, more particularly, to systems and methods for turbine repair by automated location and clearing of turbine passages or automated location and modification.
Gas turbine engines include several components that are repeatedly exposed to high temperature and high pressure fluids. These components include, for example, the nozzles of a turbine stage, which are disposed in the turbine stage to direct flows of the fluids toward bucket stages. Each nozzle may include an inboard platform section, an endwall section and an airfoil section interposed between the inboard platform section and the endwall section. The airfoil section has a leading edge and a trailing edge defined with respect to the predominant direction of flow through the turbine stage and opposite pressure and suction sides extending between the leading and trailing edges.
Each of the nozzles may be formed of a metallic substrate material that is coated with a thermal or environmental barrier coating (TBC or EBC). The coating is provided to protect the underlying metallic substrate material from damages associated with exposure of the metallic substrate material to the high temperature and high pressure fluids. Each nozzle is further formed to define fluid flow passages, such as film fluid flow passages or diffusion holes, at one or both of the pressure and suction sides. These fluid flow passages allow for coolant to be directed toward various areas of the nozzles to decrease the risk of damage due to exposure to the fluids.
During original part manufacture, the fluid flow passages of the nozzles are normally formed after the coating is applied. However, during repair processes, the coating may be stripped with the metallic substrate material subsequently re-coated. In these cases, cleaning and restoration of the fluid flow passages after the coating is stripped and the metallic substrate material is re-coated present significant challenges. Such challenges arise from the fact that restoration of the fluid flow passages to their original geometry and removing all coating debris from their corresponding passages is important to the quality of the repair. In addition, the number of the fluid flow passages may be substantial (i.e., there may be hundreds of fluid flow passages).
According to one aspect of the invention, a repair method is provided and includes deriving, from a model of a component, drilling vectors respectively associated with fluid flow passages of the component, obtaining location data of each of the fluid flow passages at least partially from a source other than the model and relying upon the derived drilling vectors and the obtained location data of each of the fluid flow passages to position a tool configured to modify each of the fluid flow passages.
According to another aspect of the invention, a repair method for use with a component including fluid flow passages is provided. The method includes deriving, from a model of the component, drilling vectors respectively associated with the fluid flow passages, assuming that the derived drilling vectors are accurate, obtaining location data for the fluid flow passages at least partially from a source other than the model and positioning a tool configured to modify each of the fluid flow passages in accordance with the derived drilling vectors and the obtained location data.
According to another aspect of the invention, a system for automatically locating and clearing fluid flow passages of a component is provided. The tool includes a memory unit in which a model of the component is stored, the model comprising drilling vectors respectively associated with each of the fluid flow passages, a scanning unit disposed to generate location data of each of the fluid flow passages from a scan of the component, a repairing unit configured to automatically clear and reestablish each of the fluid flow passages and a processing unit disposed to access the memory unit and the scanning unit and to position the repairing unit in accordance with the drilling vectors and the location data.
According to yet another aspect of the invention, an automated passage location and modifying tool is provided and includes an automated manipulator, first and second heads, which are respectively configured to be coupled to the automated manipulator, the first head being configured to scan at least a portion of a component and the second head being configured to dispense material with respect to the component, and a controller configured to position the first and second heads relative to the component. The positioning of at least the second head is in accordance with drilling vectors of fluid flow passages derived from a model of the component and a result of the scan of the component by the first head.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
With reference to
With reference to
During original part manufacture, the fluid flow passages 22 are normally formed after the bondcoat 24 and the coating 21 are applied. However, during repair processes, the coating 21 may be stripped with the metallic substrate material 20 and bondcoat 24 subsequently re-coated with a new coating 21′. In these cases, the stripping and re-coating processes often result in debris 23 (see
With reference to
With the understanding that the location data of the passage 220 can vary significantly from the desired location defined in the original equipment manufacturer (OEM) computer aided design (CAD) model of the component 10 but that the orientation data of the passage 220 may be substantially accurate between the OEM CAD model and the actual component 10, a system or tool 30 is provided for automatically locating and modifying (or clearing) the fluid flow passages 22 of the component 10. With reference to
The memory unit 31 may be any type of computer readable storage medium and has a model 310 of the component 10 stored thereon. The model 310 includes drilling vectors 311, which are respectively associated with each of the fluid flow passages 22. The model 310 may further include original OEM CAD location data 312 of each of the fluid flow passages. Such OEM CAD location data 312 may be employed as a reference to roughly position the tool 30 (or the repairing unit 33) or as a way of limiting a scanned portion of the component 10 to only those areas that include fluid flow passages 22 or to only those areas associated with some or a predefined portion of the fluid flow passages 22.
The scanning unit 32 may be disposed to generate at least actual location data 320 of each of the fluid flow passages 22 from a scan of the component 10, or in the case of the partial scan, to generate the actual location data 320 from the partial scan and from calculations of location data derived from the partial scan. The generated actual location data 320 may be stored in the scanning unit 32 or the memory unit 31. In accordance with embodiments, this scan may be performed by the scanning unit 32 with respect to only a portion of the component 10 such as the rows 223 of fluid flow passages 22 (see
In accordance with further alternative embodiments, the scanning unit 32 may be configured to electromagnetically, photographically or use optical based metrology to scan the component 10. In the case of electromagnetic scanning, the scanning unit 32 may include an electromagnetic probe 321, such as an eddy current probe) that is responsive to empty fluid flow passages 22 or to permanent magnetic material disposed in or inserted into the fluid flow passages 22 to be scanned. In the case of the photographic or optical based metrological scanning, the scanning unit 32 may include an optical scanner 322, infrared scanner, a black light element, etc., and in any case is configured to photographically or use optical based metrology to scan the fluid flow passages 22 from multiple angles. In accordance with still further alternative embodiments, the scanning unit 32 may perform the scanning with the component 10 in a serviced condition at least one of before the coating 21 is stripped, during a mid-repair process after the coating 21 is stripped, during post-processing after the re-coating of the component 10 and via an OEM scan.
The scanning may also be conducted with combined machine vision and a laser displacement sensor. In this case, a two dimensional image is processed from photographs taken of the component 10 and third dimensional data is derived from use of the laser displacement sensor. In some cases, the laser displacement sensor can be replaced with or substituted for structured laser slit beams.
The original OEM CAD location data 312 and/or the actual location data 320 may be defined relative to various reference points. For example, the original OEM CAD location data 312 and/or the actual location data 320 may be defined relative to traditional component 10 datums, relative to an external datum on the component 10 or relative to a fluid flow passage 22 datum on the component 10.
The repairing unit 33 is configured to automatically clear and reestablish each of the fluid flow passages 22. To this end, the repairing unit 33 may be positioned at various locations with respect to the component 10 and at various orientations. The initial position of the repairing unit 33 may be manually or automatically adjustable as the clearing processes proceeds from one fluid flow passage 22 to another fluid flow passage 22. Accordingly, the repairing unit 33 may include a tool portion 330 that conducts the clearing processes, a driving portion 331 that maneuvers the tool portion 330 from one fluid flow passage 22 to another and a control portion 332 that controls operations of both the tool portion 330 and the driving portion 331. In accordance with embodiments, the tool portion 330 may include at least one of a laser, a water jet, an abrasive blast, an electro-dynamic machining tool, an electro-chemical machining tool and a machining tool.
The control portion 332 may include servo elements coupled to the driving portion 331 while the processing unit 34 may be a component of the control portion 332 or a standalone feature. In either case, the processing unit 34 is disposed to access the memory unit 31 and the scanning unit 32 and to position the repairing unit 33 by issuing appropriate commands to the servo elements of the control portion 332. More particularly, the processing unit 34 accesses at least the drilling vectors 311 of the memory unit 31 and is receptive of the actual location data 320 from the scanning unit 32.
The processing unit 34 is thus able to fully define three-dimensional coordinates of the passages 220 of the fluid flow passages 22 to be cleared and is configured to position the repairing unit 33 in accordance with the drilling vectors 311 and the actual location data 320. That is, the nominal model 310 is transformed into an actual model through a shifting of the location data of the fluid flow passages 22 to reflect their actual positions with virtually no change in the orientations (i.e., drilling vectors) of the fluid flow passages 22 from the nominal model 310 to the actual model. In accordance with further embodiments, the processing unit 34 may also access the original OEM CAD location data 312 of the memory unit 31 and use such data to validate and verify the actual location data 320.
In accordance with further aspects of the invention and, with reference to
With reference to
The automated tool 300 includes a base 301, an automated manipulator (e.g., a robotic arm) 302 supported on the base 301, a single- or multi-axis positioner unit 303 disposed proximate to the base 301 and on which the component 10 may be disposed, first and second heads 304 and 305, which may be permanently coupled to a distal end of the automated manipulator 302 or replaceable at the distal end of the automated manipulator 302, and a controller 306. The first head 304 may be provided as the scanning unit 32 described above while the automated manipulator 302 and the controller 306 may include the other elements of the tool 30 (i.e., the memory unit 31 and the processing unit 34). Thus, the controller 306 may be employed to derive the drilling vectors 311 of the component 10 and the first head 304 may be employed to obtain the actual location data 320 of all of the fluid flow passages 22 of the component 10, a predefined portion of the fluid flow passages 22 or a portion of the fluid flow passages 22 that do not require crack filling operations.
In accordance with embodiments, with the drilling vectors 311 derived and the actual location data 320 obtained, the first head 304 may be substituted for or replaced by the second head 305 and the automated manipulator 302 may be controlled by the controller 306 to position the second head 305 with respect to the component 10 (or vice versa). More particularly, the automated manipulator 302 may be controlled by the controller 306 to position the second head 305 to perform dispensation of material into those fluid flow passages 22 of the component 10 that do not require crack filling operations such that braze material is not permitted to enter these fluid flow passages 22.
In accordance with further alternative embodiments of the invention and, with reference to
As shown in
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.