System and method for performing maintenance on a turbine rotor

Abstract

Systems and methods for performing maintenance on a turbine rotor. A system (100) for performing maintenance on a turbine rotor (108). The system (100) includes a rotor mount (102) configured to receive the turbine rotor (108), a robotic device (104), a visual inspection device (120) removably coupled to the robotic device (104), and a computing device (106). The computing device (106) is configured to direct the robotic device (104) to evaluate the turbine rotor (108) at different circumferential locations of the turbine rotor with the visual inspection device (120) to obtain rotor axis data, determine a centerline (150) of the turbine rotor (108) based on the rotor axis data, generate a coordinate system that includes the centerline (150) of the turbine rotor (108), direct the robotic device (104) to evaluate each blade on at least one stage (112) of the turbine rotor (108) with the visual inspection device (120) to obtain blade position data relative to the centerline (150), and populate the coordinate system with the blade position data.

Description

BACKGROUND

[0001] The present disclosure relates generally to turbine rotor maintenance operations, and more particularly, to systems and methods of calibrating a robotic device for performing maintenance on a turbine rotor.

[0002] Many types of industrial machines, such as gas turbines, include components enclosed within an outer housing or casing. Such components require periodic maintenance, such as inspection and repair, during the life cycle of the gas turbine to extend the life of the components and / or the gas turbine as a whole. At least some known maintenance operations are performed while the gas turbine is deactivated by removing the housing and disassembling the gas turbine as necessary to provide access to a rotor assembly of the gas turbine. However, such maintenance can be technically difficult, time consuming, laborious, and expensive to perform. Once disassembled, visual inspection of the rotor assembly is typically performed manually by a technician to identify components or portions of components that can require maintenance. Manually visual inspecting the rotor assembly is likewise a time consuming and laborious task. The above-described maintenance operations incur labor costs and non-productive downtime costs for the gas turbine. SUMMARY

[0003] In one aspect, a system for performing maintenance on a turbine rotor is provided. The system includes a rotor mount configured to receive the turbine rotor, a robotic device, a visual inspection device removably coupled to the robotic device, and a computing device. The computing device is configured to direct the robotic device to evaluate the turbine rotor at different circumferential locations of the turbine rotor with the visual inspection device to obtain rotor axis data, determine a centerline of the turbine rotor based on the rotor axis data, generate a coordinate system including the centerline of the turbine rotor, direct the robotic device to evaluate a plurality of blades on at least one stage of the turbine rotor with the visual inspection device to obtain blade position data relative to the centerline, and populate the coordinate system with the blade position data.

[0004] In another aspect, a method of calibrating a robotic device for performing maintenance on a turbine rotor is provided. The method includes evaluating the turbine rotor at different circumferential locations of the turbine rotor with a visual inspection device to obtain rotor axis data, determining a centerline of the turbine rotor based on the rotor axis data, generating a coordinate system including the centerline of the turbine rotor, evaluating a plurality of blades on at least one stage of the turbine rotor with the visual inspection device to obtain blade position data relative to the centerline, and populating the coordinate system with the blade position data.

[0005] In yet another aspect, a method of calibrating a robotic device for performing maintenance on a turbine rotor is provided. The method includes evaluating the turbine rotor at different circumferential locations of the turbine rotor using a visual inspection device on the robotic device to obtain rotor axis data, determining a centerline of the turbine rotor based on the rotor axis data, evaluating a plurality of blades on at least one stage of the turbine rotor using the visual inspection device to obtain blade position data relative to the centerline, and performing a visual inspection of the blades of the turbine rotor using the visual inspection device while obtaining the blade position data. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a block diagram illustrating an example calibration and maintenance system.

[0007] Figure 2 is Figure 1 a perspective view of the calibration and maintenance system shown.

[0008] Figure 3 is an example coordinate system that can be generated by Figure 2 the system shown.

[0009] Figure 4 is a flowchart illustrating an example method of calibrating a robotic device for performing maintenance on a turbine rotor. DETAILED DESCRIPTION

[0010] The embodiments described herein relate to systems and methods of performing maintenance on a turbine rotor. In example embodiments, a robotic device is used to perform maintenance on the rotor. Calibration of the robotic device facilitates accurate determination of the position of the rotor blades on the turbine rotor to enable automated maintenance operations to be initiated after the calibration is performed. In example embodiments, the robotic device is a multi-axis robot, such as a 7-axis robot, having an end effector attached thereto. To calibrate the robotic device, a visual inspection device end effector is attached to the robotic device for evaluating the turbine rotor and generating a three-dimensional coordinate system. The coordinate system is defined by a rotor axis centerline and a plurality of blade coordinate points populated around the centerline, both of which are determined based on the evaluation. In some embodiments, the visual inspection device also evaluates the turbine rotor for potential defects when the rotor axis and blade position data is obtained. The generated coordinate system can be used to control the motion of the robotic device relative to the turbine rotor when performing post-calibration maintenance operations. For example, after the coordinate system is generated, the visual inspection device can be removed from the robotic device to enable a different end effector to be attached to the robotic device for performing maintenance operations. Thus, the systems and methods described herein facilitate evaluating a turbine rotor in a fast and efficient manner to enable automated maintenance operations to be performed in a manner that is beneficial for reducing downtime of the associated gas turbine assembly.

[0011] Approximating language, such as, for example, "substantially", "approximately", and "about”, as used herein, refers to that which would be understood by one of ordinary skill in the art to be close to, but not necessarily exact, as understood by one of ordinary skill in the art. Thus, for example, a value modified by a term or terms, such as "about”, "approximately”, and "substantially”, refers to a value that is not exact, but would be understood by one of ordinary skill in the art to be close to the exact value. In at least some instances, the approximate language can correspond to the precision with which a value is measured. In addition, the use of terms such as "first”, "second”, and the like does not imply any order or sequence unless specifically so defined by the context in which such terms are used. Further, a reference to a "second” item does not require or preclude the existence of a "first” item or a "third” item, for example.

[0012] Figure 1 and Figure 2 An example calibration and maintenance system 100 is shown. In an example embodiment, the system 100 includes a rotor mount 102, a robotic device 104, and a computing device 106. The rotor mount 102 is designed to receive and hold a turbine rotor 108, for example, that has been disassembled and removed from an associated turbine engine (not shown) for servicing. The turbine rotor 108 includes a shaft 110 and a plurality of stages 112 spaced along the shaft 110, where each stage 112 includes a plurality of blades 114 extending radially outward from the shaft 110. As shown, the rotor mount 102 includes a pair of ground-based support members 116 spaced apart from one another to enable the turbine rotor 108 to be coupled therebetween. For example, the support members 116 can be coupled to the shaft 110 of the turbine rotor 108 in a manner that enables the turbine rotor 108 to be rotated on the rotor mount 102. Figure 2

[0013] The robotic device 104 is any automated robotic system or device that enables the system 100 to function as described herein. As shown, the robotic device 104 is a 7-axis robot having an end effector 118 removably coupled thereto. Example end effectors include, but are not limited to, a visual inspection device 120 and a maintenance tool 122. In one embodiment, the visual inspection device 120 is a two-dimensional camera and laser vision system, a laser profilometer, a three-dimensional structured light scanner, or a stereo camera system. The maintenance tool 122 is configured to perform at least one of a cleaning operation, a blending operation (i.e., cleaning, polishing, and / or machining the rotor blades to modify their geometry), a non-destructive inspection operation, and / or a repair operation on the turbine rotor 108. Figure 2

[0014] ​​The computing device 106 is communicatively coupled to the rotor mount 102 and the robotic device 104. The computing device includes a memory 124 (i.e., a non-transitory computer readable medium) and a processor 126 coupled to the memory 124 for executing programmed instructions. The processor 126 can include one or more processing units (e.g., in a multi-core configuration) and / or include a cryptographic accelerator (not shown). The computing device 106 is programmable to perform one or more operations described herein by programming the memory 124 and / or the processor 126. For example, the processor 126 can be programmed by encoding an operation as executable instructions and providing the executable instructions in the memory 124.

[0015] The processor 126 can include, but is not limited to, a general central processing unit (CPU), a microcontroller, a reduced instruction set computer (RISC) processor, an open media applications platform (OMAP), an application specific integrated circuit (ASIC), a programmable logic circuit (PLC), and / or any other circuit or processor capable of executing the functions described herein. The methods described herein can be encoded as executable instructions embodied in a computer readable medium, including, but not limited to, a storage device and / or memory device. These instructions, when executed by the processor 126, cause the processor 126 to perform at least a portion of the functions described herein. The above examples are merely exemplary and thus are not intended to limit, in any way, the definition and / or meaning of the term processor.

[0016] The memory 124 is one or more devices that enable information, such as executable instructions and / or other data, to be stored and retrieved. The memory 124 can include one or more computer readable media, such as, but not limited to, a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a static random access memory (SRAM), a solid state disk, and / or a hard disk. The memory 124 can be configured to store, without limitation, executable instructions, operating systems, application programs, resources, installation scripts, and / or any other type of data suitable for use in the methods and systems described herein.

[0017] Instructions for operating systems and applications are located on non-transitory memory 124 in functional form, for execution by processor 126 to perform one or more of the processes described herein. These instructions in different implementations can be embodied on different physical or tangible computer-readable media, such as memory 124 or another memory, such as a computer-readable medium (not shown), which can include, but is not limited to, a flash drive and / or thumb drive. Further, the instructions can be located on a non-transitory computer-readable medium in functional form, which can include, but is not limited to, a smart media (SM) memory, a compact flash (CF) memory, a secure digital (SD) memory, a memory stick (MS) memory, a multimedia card (MMC) memory, an embedded multimedia card (e-MMC), and a micro drive memory. The computer-readable medium can be selectively inserted and / or removed from computing device 106 to allow processor 126 access and / or execution. In alternative implementations, the computer-readable medium is non-removable.

[0018] As shown, rotor mount 102 is in a fixed position on a ground surface 128 within a maintenance facility (not shown). Robotic device 104 has a limited range of motion and reach, and is selectively movable relative to rotor mount 102 to perform an evaluation of turbine rotor 108. For example, robotic device 104 can be movable, such as via a wheeled platform or a track system (both not shown), substantially parallel to a rotor axis 130 of turbine rotor 108 to facilitate an evaluation of turbine rotor 108 from a first end 132 to a second end 134 of shaft 110. Further, such movement of device 104 enables an evaluation of each stage 112 of turbine rotor 108 positioned therebetween, as will be explained in greater detail below. Throughout the evaluation and inspection process, robotic device 104 can also move end effector 118 to be positioned at different circumferential locations relative to turbine rotor 108. Figure 2

[0019] In operation, system 100 evaluates turbine rotor 108 with vision inspection device 120 to facilitate generation of a three-dimensional coordinate system. Further, when the 3D coordinate system is generated, system 100 is also calibrated to perform subsequent maintenance operations on turbine rotor 108 with robotic device 104. To calibrate robotic device 104, robotic device 104 first evaluates turbine rotor 108 to determine a centerline thereof. For example, computing device 106 directs robotic device 104 to evaluate turbine rotor 108 at different circumferential locations with vision inspection device 120 to obtain rotor axis data. In one embodiment, the outer surface 136 of shaft 110 is evaluated to obtain rotor axis data, although any other circumferential surface of turbine rotor 108 can also be evaluated to obtain rotor axis data.

[0020] ​As shown in Figure 3 At least three rotor coordinate points 138 (i.e., rotor axis data) are obtained at the first end 132 of the shaft 110, and at least three rotor coordinate points 140 (i.e., rotor axis data) are obtained at the second end 134 of the shaft 110. A first user frame 142 is then defined at one of the coordinate points 138. The first user frame 142 is used to define a plane within the coordinate system, and a first center point 144 is defined on the plane. The first center point 144 of the shaft 110 is at the first end 132, and is determined based on the rotor coordinate points 138. A second center point 146 of the shaft 110 at the second end 134 is determined based on the rotor coordinate points 140. The center points 144 and 146 are saved in the coordinate system 100, and a second user frame 148 is created based on the determined center points 144 and 146 to determine a centerline 150 of the turbine rotor 108. For example, at least one axis (e.g., the X-axis) of the second user frame 148 is defined as the centerline 150 of the turbine rotor 108, which is generally the axis of the airflow in the turbine. Optionally, the second user frame 148 is rotated about its Y-axis. Then, as the shaft 110 is rotated on the rotor mount 102 (shown in Figure 2 ), the second user frame 148 is fixed relative to the shaft 110 of the turbine rotor 108 and rotates with it. Additional evaluations of the turbine rotor 108 are facilitated to populate the coordinate system 100 relative to the second user frame 148 and the centerline 150.

[0021] For example, and again referring to Figure 2 , the computing device 106 directs the robotic device 104 to evaluate each blade 114 on each stage 112 of the turbine rotor 108 to obtain a coordinate point 152 relative to the centerline 150 (shown in Figure 3In one embodiment, the computing device 106 directs the robotic device 104 to evaluate the first blade 152 of the first stage 154 of the turbine rotor 108, and then evaluate successive blades 114 of the first stage 154 to the first blade 114 by moving the vision inspection device 120 relative to the turbine rotor 108. The first stage 154 can be evaluated until the range of motion of the robotic device 104 is reached. The robotic device 104 can then evaluate the blades 114 of successive axially adjacent stages 112 on the turbine rotor 108 by moving the robotic device 104 relative to the rotor axis 130. In one embodiment, the rotor mount 102 holds the turbine rotor 108 in a first rotational orientation relative to the robotic device 104 as the robotic device 104 evaluates each stage 112. In such embodiments, the robotic device 104 can move the vision inspection device 120 in a spiral pattern relative to the turbine rotor 108 across the respective stage 112, to the successive adjacent stage 112, across the successive adjacent stage 112, and so on. The rotor mount 102 can then rotate the turbine rotor 108 to a second rotational orientation relative to the robotic device 104, which enables the evaluation of blades 114 on each stage 112 that were outside the range of motion of the robotic device 104 when the turbine rotor 108 was in the first rotational orientation.

[0022] In alternative embodiments, the turbine rotor 108 can be continuously rotated on the rotor mount 102 as the blades 114 of each stage 112 are evaluated by the vision inspection device 120. In such embodiments, each successive blade 114 on the first stage 154 is evaluated as the turbine rotor 108 is rotated, and then the robotic device 104 is selectively moved to evaluate each successive stage 112 relative to the rotor axis 130.

[0023] In exemplary embodiments, the computing device 106 controls the movement of the end effector 118 relative to the turbine rotor 108 based on the number of blades 114 in each stage 112. For example, in one embodiment, the number of blades 114 in each stage 112 is stored in the memory 124 (shown in FIG. 1) of the computing device 106. The computing device 106 can then control the movement of the end effector 118 relative to the turbine rotor 108 based on the number of blades 114 in each stage 112. Figure 1A known amount in the coordinate system 100 (shown in FIG. 1) is then determined. The computing device 106 can then determine a predetermined radial angle between each vane 114 in the corresponding stage 112. For example, if the corresponding stage 112 contains 60 vanes, the predetermined radial angle between each vane 114 is approximately 3 degrees. In some embodiments, the computing device 106 moves the end effector 118 from one vane to another vane based at least in part on feedback received from the visual inspection device 120. For example, the visual inspection device 120 can evaluate the first vane 152, and then each successive vane 114 needs to be "found" by the visual inspection device 120 for subsequent evaluation. Moving the end effector 118 from one vane to another vane on the corresponding stage 112 of the turbine rotor 108 based on the predetermined radial angle facilitates evaluating the turbine rotor 108 in an efficient and time-reduced manner.

[0024] As described above, the computing device 106 directs the robotic device 104 to evaluate each vane 114 on each stage 112 of the turbine rotor 108 to obtain vane position data. In an exemplary embodiment, as shown in FIG. 2, the robotic device 104 evaluates each vane to obtain a leading edge coordinate point 156 and a trailing edge coordinate point 158 for each vane 114, thereby determining the position of each vane 114 relative to the centerline 150. The coordinate points 156 and 158 for each vane 114 are populated in the coordinate system 100, which can then be used to control movement of the end effector 118 when performing maintenance operations on the turbine rotor 108, as described above. Figure 3

[0025] In one embodiment, a visual inspection of each vane 114 is performed with the visual inspection device 120 when the vane position data is obtained. The visual inspection is performed to identify vanes 114 having potential defects thereon. In addition, a unique identifier (not shown) can be assigned to each vane 114 identified in the coordinate system 100. Thus, the unique identifier of the vanes 114 identified as having potential defects thereon is stored in the memory 124 and can be used to coordinate future performance of maintenance operations on the turbine rotor 108.

[0026] Figure 4 is a flowchart illustrating an exemplary method 200 of calibrating a robotic device for performing maintenance on a turbine rotor. The method 200 includes evaluating 202 a turbine rotor at different circumferential locations of the turbine rotor to obtain rotor axis data, determining 204 a centerline of the turbine rotor based on the rotor axis data, generating 206 a coordinate system including the centerline of the turbine rotor, evaluating 208 each vane on at least one stage of the turbine rotor to obtain vane position data relative to the centerline, populating 210 the coordinate system with the vane position data, and performing 212 a visual inspection of the vanes of the turbine rotor when the vane position data is obtained.

[0027] ​The embodiments described herein relate to systems and methods of performing maintenance on a turbine rotor in a fast, effective, and repeatable manner. By calibrating a robotic device with a visual inspection device, manual inspection of the turbine rotor is no longer required, thereby reducing the potential for human error and tool damage. Accordingly, the systems and methods described herein facilitate the evaluation of a turbine rotor in a fast and effective manner, thereby enabling automated maintenance operations to be performed and reducing the associated downtime of the gas turbine assembly.

[0028] The above description is intended to be illustrative, and one skilled in the art will recognize that modifications can be made to the described embodiments without departing from the scope of the disclosed application. For example, the process steps described herein can be modified, e.g., in terms of duration, temperature, or time between cycles. Other modifications that fall within the scope of the present application will be apparent to those skilled in the art in light of a review of this disclosure, and such modifications are intended to fall within the scope of the appended claims.

[0029] Exemplary embodiments of an active brazed joint and methods of processing the same are described in detail above. The methods are not limited to the specific embodiments described herein, but rather the steps of the methods can be utilized independently and apart from other steps described herein. For example, the methods described herein are not limited to practice with only joints used in the hot gas path of a gas turbine engine as described herein. Rather, the exemplary embodiments can be implemented and used in conjunction with many other applications.

[0030] While specific features of various embodiments of the application can be shown in some drawings and not in others, this is for convenience only. In addition, every reference to "one embodiment" in the above description is not intended to exclude other embodiments that also incorporate such features. According to the principles of the application, any feature of one drawing can be incorporated into any other drawing.

[0031] While the application has been described in terms of various specific embodiments, those skilled in the art will recognize that the application can be practiced with modifications within the spirit and scope of the claims.

Claims

1. A system (100) for performing maintenance on a turbine rotor (108), the system (100) comprising: a rotor mount (102) configured to receive the turbine rotor (108); a robotic device (104); a visual inspection device (120) coupled to the robotic device (104); and a computing device (106) configured to: direct the robotic device (104) to evaluate the turbine rotor (108) at different circumferential locations of the turbine rotor with the visual inspection device (120) to obtain rotor axis data; determine a centerline (150) of the turbine rotor (108) based on the rotor axis data; generate a coordinate system that includes the centerline (150) of the turbine rotor (108); direct the robotic device (104) to evaluate a plurality of blades (114) on at least one stage (112) of the turbine rotor (108) with the visual inspection device (120) to obtain blade position data relative to the centerline (150); and populate the coordinate system with the blade position data.

2. The system (100) of claim 1, further comprising a maintenance tool (122) coupled to the robotic device (104), wherein the maintenance tool (122) is configured to perform a maintenance operation on the turbine rotor (108) based on the coordinate system.

3. The system (100) of claim 2, wherein the maintenance tool (122) is configured to perform at least one of a cleaning operation, a mixing operation, a non-destructive inspection operation, or a repair operation.

4. The system (100) of claim 1, wherein the rotor mount (102) is rotatable to rotate the turbine rotor (108) relative to the robotic device (104).

5. The system (100) of claim 1, wherein the visual inspection device (120) is an end effector (118) of the robotic device (104), wherein the computing device (106) directs the robotic device (104) to evaluate the turbine rotor (108) by moving the visual inspection device (120) relative to the turbine rotor (108).

6. The system (100) of claim 1, wherein the computing device (106) is further configured to direct the robotic device (104) to perform a visual inspection of a blade (114) of the turbine rotor (108) with the visual inspection device (120) while obtaining the blade position data.

7. A method of calibrating a robotic device (104) for performing maintenance on a turbine rotor (108), the method comprising: evaluating the turbine rotor (108) at different circumferential locations of the turbine rotor with a visual inspection device (120) to obtain rotor axis data; determining a centerline (150) of the turbine rotor (108) based on the rotor axis data; generating a coordinate system including the centerline (150) of the turbine rotor (108); evaluating a plurality of blades (114) on at least one stage (112) of the turbine rotor (108) using the visual inspection device (120) to obtain blade position data relative to the centerline (150); and populating the coordinate system with the blade position data.

8. The method of claim 7, wherein evaluating the turbine rotor (108) includes evaluating a surface (136) of a shaft (110) of the turbine rotor (108) to obtain the rotor axis data.

9. The method of claim 8, wherein evaluating the surface (136) of the shaft (110) includes obtaining a first set of at least three rotor coordinate points (138) at a first end (132) of the shaft (110) and obtaining a second set of at least three rotor coordinate points (140) at an opposite second end (134) of the shaft (110).

10. The method of claim 7, wherein the visual inspection device (120) is an end effector (118) of the robotic device (104), wherein evaluating the turbine rotor (108) includes moving the visual inspection device (120) relative to the turbine rotor (108).

11. The method of claim 10, wherein evaluating blade position includes evaluating a first blade of the at least one stage (112) and then evaluating a blade (114) of the at least one stage (112) successive to the first blade.

12. The method of claim 11, wherein successively evaluating each blade (114) includes rotating the turbine rotor (108) relative to the robotic device (104).

13. The method of claim 11, wherein successively evaluating each blade (114) includes: determining a predetermined radial angle between each blade (114) in the at least one stage (112) based on a number of blades (114) in the at least one stage (112); and controlling movement of the visual inspection device (120) relative to the turbine rotor (108) based on the predetermined radial angle.

14. The method of claim 7, wherein evaluating blade position includes obtaining a leading edge coordinate point (156) and a trailing edge coordinate point (158) of each blade (114) in the at least one stage (112) to define the blade position data.

15. The method of claim 7, further comprising performing a maintenance operation on the turbine rotor (108) using the robotic device (104) based on the coordinate system. ​

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