A large-scale mixed-flow turbine runner crack repair device

Abstract

This utility model discloses a large-scale mixed-flow turbine runner crack repair device, including a robotic arm, a longitudinal seat, a connecting seat, a lifting seat, and a drive device. The connecting seat is installed on one side of the longitudinal seat, and the lifting seat is longitudinally guided and slidably installed on one side of the longitudinal seat. The connecting seat is used for installation and connection with the tailrace pipe of the mixed-flow turbine. The drive device is installed on the lifting seat and is driven by the lifting seat to drive the lifting seat to move longitudinally. The base of the robotic arm is installed on the lifting seat, and the free end of the robotic arm is used to install repair tools. This utility model has a simpler structure and is more convenient for single-unit installation, making it suitable for operation scenarios with fewer runner crack defects, through the installation and connection of the connecting seat to the tailrace pipe of the mixed-flow turbine, the drive device driving the lifting seat to move longitudinally, and the base of the robotic arm installed on the lifting seat.

Description

Technical Field

[0001] This utility model relates to the field of large mixed-flow turbine runner repair technology, and in particular to a device for repairing cracks in large mixed-flow turbine runners. Background Technology

[0002] The runner is the core component of a mixed-flow turbine unit. It consists of an upper crown, lower ring, and blades welded together as a single unit, made of low-carbon martensitic stainless steel. As an energy conversion station, the runner's performance has a decisive impact on the safe and stable operation of the turbine. After a certain period of operation, large-scale mixed-flow turbine units, both domestically and internationally, are prone to developing linear or through-cracks in their runners. These cracks are mostly located at the welds between the blades and the upper crown / lower ring, and can be detected visually or through non-destructive testing. The main causes of these cracks are a combination of factors, including design, manufacturing (such as casting defects and welding stress), materials (such as fatigue stress), and operational factors.

[0003] Cracks in the runners of large mixed-flow turbines with a diameter of 5 meters or more have become a frequent problem in the hydropower industry. Cracks not only reduce turbine efficiency but can also lead to blade damage or even malfunction, threatening the reliability and safety of hydropower generation. Currently, the main method for repairing cracks in large mixed-flow turbine runners is to lift the runner to the plant's main hall and then use a combination of manual carbon arc gouging and grinding to completely remove the cracked area. Martensitic stainless steel is a difficult material to process, and the extremely limited working space—with an average blade spacing of only 300mm—severely affects the condition and skill level of technicians. Furthermore, the repair schedule is tight, requiring long hours of continuous work by a single person, high intensity, and susceptibility to fatigue, which negatively impacts welding quality.

[0004] In the prior art, Chinese patent document CN217858967U discloses a turbine runner blade trimming turntable and turbine runner blade trimming equipment, including a base, a support base, and a positioning pin. The support base is coaxially connected to the base and can rotate relative to the base about its axis. The base / support base is provided with positioning holes matching the number of turbine runner blades. The support base / base has a positioning pin on its edge, with one end connected to the support base / base and the other end matching the positioning hole. Its advantages are: the provided turbine runner blade trimming turntable and turbine runner blade trimming equipment allow for the pre-installation and debugging of a robotic arm at the power plant site. The rotation of the trimming turntable allows for group trimming of blades from the same runner, significantly reducing the trimming cycle and meeting the power plant maintenance requirements. Its disadvantage is: when using this method for repair, the turbine runner blades need to be hoisted out to the plant lobby for processing.

[0005] To address the aforementioned issues, Chinese patent document CN114274116A discloses a hybrid additive and subtractive manufacturing device for a mobile robot used in water turbines. The device includes: a circular track formed by splicing; an additive robot mounted on and capable of moving along the circular track, the additive robot equipped with additive tools and an additive 3D vision measurement tool; and a subtractive robot mounted on and capable of moving along the circular track, the subtractive robot equipped with subtractive tools and a subtractive 3D vision measurement tool. Its advantages are: it can simultaneously perform hybrid additive and subtractive manufacturing operations, enabling in-situ repair of water turbines, ensuring it is unaffected by harsh on-site environments, and ensuring stable processing quality, achieving efficient and precise repair of the flow surfaces of large water turbines. Its disadvantages are: during repair, a circular track needs to be installed, making it suitable for situations with numerous runner cracks. If there are few runner cracks, such as only one or two, this solution would consume a significant amount of manpower and time to install the circular track, making it unsuitable for scenarios with few runner cracks. Utility Model Content

[0006] The technical problem to be solved by this utility model is to address the problems existing in the background art and provide a large mixed-flow turbine runner crack repair device. The device is installed and connected to the tailrace pipe of the mixed-flow turbine through a connecting seat. The driving device drives the lifting seat to move longitudinally. The base of the robotic arm is installed on the lifting seat. The structure is simpler and the single-unit installation is more convenient. It is suitable for operation scenarios with fewer runner crack defects.

[0007] To achieve the above-mentioned technical features, the purpose of this utility model is as follows: A large-scale mixed-flow turbine runner crack repair device includes a robotic arm, a longitudinal seat, a connecting seat, a lifting seat, and a driving device. The connecting seat is installed on one side of the longitudinal seat, and the lifting seat is longitudinally guided and slidably installed on one side of the longitudinal seat. The connecting seat is used for installation and connection with the tailrace pipe of the mixed-flow turbine. The driving device is installed on the lifting seat and is connected to the lifting seat for transmission to drive the lifting seat to move longitudinally. The base of the robotic arm is installed on the lifting seat, and the free end of the robotic arm is used to install repair tools.

[0008] The connecting seat includes a mounting plate and an extension. The mounting plate is fixed to one end of the extension, and the other end of the extension is used for welding the tailwater pipe. The longitudinal seat is mounted on the mounting plate.

[0009] The longitudinal seat has extension plates on its left and right sides, and the extension plates are connected to the mounting plate by connecting bolts.

[0010] The protruding plate is also threaded with multiple adjusting screws, the threaded ends of which abut against the mounting plate, and limit nuts are screwed onto the adjusting screws.

[0011] Two linear guide rails are longitudinally spaced on one side of the longitudinal seat and the lifting seat. At least two sliders are installed on each linear guide rail. The sliders are slidably mounted on the linear guide rails, and the lifting seat is mounted on the sliders.

[0012] The slider is equipped with a slide plate, and the lifting seat is bolted to the slide plate.

[0013] Dustproof covers are installed at the upper and lower ends of the longitudinal seat, and a bellows cover is installed between the dustproof cover and the slide plate. The upper and lower ends of the bellows cover are bolted to the slide plate and the dustproof cover, respectively.

[0014] Dustproof plates are installed on the left and right sides of the slide plate, covering the slider, and the upper and lower ends of the dustproof plates are bolted to the bellows cover.

[0015] A longitudinal groove is provided on the side where the longitudinal seat connects to the lifting seat, and the drive device is installed in the longitudinal groove.

[0016] The drive device includes a driver, a ball screw, a coupling, and a screw nut. A mounting base is fixed on the longitudinal seat, and the driver is mounted on the mounting base. One end of the ball screw is connected to the longitudinal seat through a bearing seat, and the other end is connected to the output shaft of the driver through a coupling. A screw nut is fixedly installed on the lifting seat. The ball screw is arranged longitudinally, and the screw nut is threadedly engaged with the ball screw. The driver includes either a servo motor or a stepper motor.

[0017] Compared with the prior art, the present utility model adopting the above technical solution has the following characteristics:

[0018] 1. The longitudinal seat of this utility model is connected to the tailwater pipe via a connecting seat, and the drive device is connected to the lifting seat for transmission, thereby driving the lifting seat to move longitudinally up and down. The base of the robotic arm is installed on the lifting seat, thereby driving the robotic arm to move up and down to adapt to different height positions of defects in the mixed-flow impeller. The free end of the robotic arm is used to install different repair tools for repairing defects. The repair tools can be the medium-sized repair tools in the prior art. This utility model has a simple structure, is easy to install as a single unit, and is suitable for operation scenarios with fewer impeller crack defects.

[0019] 2. Dustproof covers are installed at the upper and lower ends of the longitudinal seat of this utility model. A bellows cover is installed between the dustproof cover and the slide plate. The upper and lower ends of the bellows cover are bolted to the slide plate and the dustproof cover, respectively, so as to prevent dust from the sliding and transmission structure of the device. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0022] Figure 2 This is a schematic diagram of the connection structure of the longitudinal seat, connecting seat, lifting seat and driving device of this utility model.

[0023] Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle.

[0024] Figure 4 This is a diagram showing the usage state of this utility model.

[0025] Figure label:

[0026] Mixed-flow impeller 1, frame 2, tailrace pipe 3;

[0027] Longitudinal seat 10, extension plate 101, longitudinal groove 102, mounting seat 103, connecting bolt 11, adjusting screw 12, limit nut 121, linear guide rail 13, slider 14, slide plate 15, dust cover 16, bellows cover 17, dust cover 18.

[0028] Connector 20, mounting plate 21, extension 22;

[0029] Lifting seat 30;

[0030] Drive unit 40, driver 41, ball screw 42, coupling 43, screw nut 44;

[0031] Robotic arm 50. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0034] Example 1:

[0035] See Figure 1-4 A large-scale mixed-flow turbine runner crack repair device includes a robotic arm 50, a longitudinal seat 10, a connecting seat 20, a lifting seat 30, and a drive device 40. The connecting seat 20 is installed on one side of the longitudinal seat 10, and the lifting seat 30 is longitudinally guided and slidably installed on one side of the longitudinal seat 10. The connecting seat 20 is used for installation and connection with the tailrace pipe 3 of the mixed-flow turbine. The drive device 40 is installed on the lifting seat 30 and is connected to the lifting seat 30 for transmission to drive the lifting seat 30 to move longitudinally. The lifting seat 30 is provided with bolt mounting holes, and the base of the robotic arm 50 is installed on the lifting seat 30 by bolts.

[0036] The longitudinal seat 10 is connected to the tailwater pipe 3 via the connecting seat 20. The drive device 40 is connected to the lifting seat 30, thereby driving the lifting seat 30 to move longitudinally. The base of the robotic arm 50 is mounted on the lifting seat 30, thereby driving the robotic arm 50 to move up and down to adapt to different height positions of defects in the mixed-flow impeller 1. The free end of the robotic arm 50 is used to install different repair tools for defect repair. The repair tools can be the medium-sized repair tools in the prior art. This utility model has a simple structure, is easy to install as a single unit, and is suitable for operation scenarios with fewer impeller crack defects.

[0037] In this embodiment, see Figure 2 , 3 The connecting seat 20 includes a mounting plate 21 and an extension 22. The mounting plate 21 is welded to one end of the extension 22, and the other end of the extension 22 is used for welding the tailwater pipe 3. The longitudinal seat 10 is mounted on the mounting plate 21. Specifically, the extension 22 can be a steel bracket.

[0038] In this embodiment, see Figure 2 There are two connectors 20, one on the top and one on the bottom.

[0039] Specifically, see Figure 3 Extending plates 101 are provided on the left and right sides of the longitudinal seat 10, and the extending plates 101 are connected to the mounting plate 21 by connecting bolts 11.

[0040] Furthermore, multiple adjusting screws 12 are threadedly installed on the protruding plate 101. The threaded end of the adjusting screw 12 abuts against the mounting plate 21, and a limit nut 121 is screwed onto the adjusting screw 12 to adjust the verticality of the longitudinal seat 10.

[0041] During adjustment, when the adjusting screw 12 is at the upper end, the threaded end of the adjusting screw 12 abuts against the mounting plate 21. Further turning the adjusting screw 12 increases the gap between the upper end of the longitudinal seat 10 and the connecting seat 20, causing the upper end of the longitudinal seat 10 to swing outwards. The gap at the lower end of the longitudinal seat 10 can be adjusted using the same method. After the gap is adjusted, use a tool to fix the adjusting screw 12, and then tighten the limit nut 121. It should be noted that when adjusting the verticality of the longitudinal seat 10, the connecting bolt 11 needs to be loosened accordingly; after adjustment, the connecting bolt 11 should be tightened again.

[0042] The longitudinal seat 10 and the lifting seat 30 can be connected by a sliding structure using a dovetail groove and a dovetail block, or by other sliding structures. In this embodiment, see [reference needed]. Figure 2 Two linear guide rails 13 are longitudinally spaced on the side where the longitudinal seat 10 is connected to the lifting seat 30 by screws. At least two sliders 14 are installed on each linear guide rail 13. The sliders 14 are slidably mounted on the linear guide rail 13. The lifting seat 30 is mounted on the sliders 14 by screws.

[0043] Furthermore, a slide plate 15 is mounted on the slider 14 by screws, and the lifting seat 30 is mounted on the slide plate 15 by bolts.

[0044] Example 2:

[0045] See Figure 2 Based on Embodiment 1, since the repair tools at the free end of the robotic arm 50 include milling tools, cladding and filling tools, and grinding tools, iron filings will fall from top to bottom during operation. Over time, this will affect the sliding fit between the lifting seat 30 and the longitudinal seat 10. Therefore, in this embodiment, dust covers 16 are installed at the upper and lower ends of the longitudinal seat 10, and a bellows cover 17 is installed between the dust cover 16 and the slide plate 15. The upper and lower ends of the bellows cover 17 are bolted to the slide plate 15 and the dust cover 16, respectively, thereby preventing dust from entering the sliding and transmission structures. In this embodiment, both the dust cover 16 and the slide plate 15 are provided with mounting holes.

[0046] Furthermore, dustproof plates 18 are respectively installed on the left and right sides of the slide plate 15, the dustproof plates 18 cover the slider 14, and the upper and lower ends of the dustproof plates 18 are respectively bolted to the upper and lower accordion covers 17 on the upper and lower sides. In this embodiment, the upper and lower ends of the dustproof plates 18 are provided with bent portions, and the bent portions are provided with holes for installing bolts.

[0047] In this embodiment, see Figure 2 The accordion cover 17 has a U-shaped structure.

[0048] Example 3:

[0049] Based on Example 1 or Example 2, see Figure 2 A longitudinal groove 102 is provided on the side where the longitudinal seat 10 is connected to the lifting seat 30, and the drive device 40 is installed in the longitudinal groove 102.

[0050] In this embodiment, the drive device 40 includes a driver 41, a ball screw 42, a coupling 43, and a screw nut 44. A mounting base 103 is fixed on the longitudinal seat 10. The driver 41 is mounted on the mounting base 103. One end of the ball screw 42 is connected to the longitudinal seat 10 through a bearing seat, and the other end is connected to the output shaft of the driver 41 through the coupling 43. A screw nut 44 is fixedly mounted on the lifting seat 30. The ball screw 42 is arranged longitudinally, and the screw nut 44 is threadedly engaged with the ball screw 42. The driver 41 includes either a servo motor or a stepper motor.

[0051] The output shaft of the driver 41 rotates, thereby driving the ball screw 42 to rotate. Since the screw nut 44 is fixedly installed at the bottom of the lifting seat 30 or the bottom of the slide plate 15, it drives the lifting seat 30 to move up and down, thereby driving the robotic arm 50 to move up and adjust the height.

[0052] In this embodiment, see Figure 2 The mounting base 103 is welded into the longitudinal groove 102, and the driver 41 is bolted to the mounting base 103. The lead screw nut 44 can be mounted on the bottom of the lifting seat 30 or the bottom of the slide plate 15 via the lead screw nut seat. The upper end of the ball screw 42 is connected to the longitudinal seat 10 via a bearing seat, and the other end is connected to the output shaft of the driver 41 via a coupling 43. The lead screw nut 44, lead screw nut seat, bearing seat, and ball screw 42 can all be purchased as finished products.

[0053] The working principle or working process of this utility model:

[0054] See Figure 4 When using this utility model, it is not necessary to lift out the mixed flow impeller 1. The worker stands on the frame 2, which is similar to scaffolding, and the extension 22 of the crack repair device connecting seat 20 is spot welded and fixed to the tailwater pipe 3 according to the location of the impeller crack.

[0055] Adjust the verticality of the longitudinal seat 10, that is, its verticality to the horizontal plane, by adjusting screw 12. After adjustment, tighten the connecting bolt 11 and install the base of the robotic arm 50 onto the lifting seat 30 using bolts.

[0056] The working height of the robotic arm 50 is adjusted by using the forward and reverse start driver 41. Then, the defect in the rotating wheel is repaired using a repair tool installed at the free end of the robotic arm 50.

[0057] After the repair is completed, the spot weld between the extension 22 and the tailpipe 3 is cut with an angle grinder, and the crack repair device is removed.

[0058] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Any modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A large Francis turbine runner crack repair device, comprising a mechanical arm (50), characterized in that: It also includes a longitudinal seat (10), a connecting seat (20), a lifting seat (30), and a drive device (40). The connecting seat (20) is installed on one side of the longitudinal seat (10), and the lifting seat (30) is longitudinally guided and slidably installed on one side of the longitudinal seat (10). The connecting seat (20) is used to install and connect with the tailrace pipe (3) of the mixed-flow turbine. The drive device (40) is installed on the lifting seat (30), and the drive device (40) is connected to the lifting seat (30) to drive the lifting seat (30) to move longitudinally. The base of the robotic arm (50) is installed on the lifting seat (30), and the free end of the robotic arm (50) is used to install repair tools.

2. The large Kaplan turbine runner crack repair device according to claim 1, characterized in that: The connecting seat (20) includes a mounting plate (21) and an extension (22). The mounting plate (21) is fixed to one end of the extension (22), and the other end of the extension (22) is used for welding the tailwater pipe (3). The longitudinal seat (10) is mounted on the mounting plate (21).

3. The large-scale mixed-flow turbine runner crack repair device according to claim 2, characterized in that: The longitudinal seat (10) is provided with extension plates (101) on the left and right sides respectively, and the extension plates (101) are connected to the mounting plate (21) by connecting bolts (11).

4. The large Kaplan turbine runner crack repair device according to claim 3, characterized in that: The protruding plate (101) is also threaded with a plurality of adjusting screws (12), the threaded end of the adjusting screws (12) abuts against the mounting plate (21), and a limit nut (121) is screwed onto the adjusting screws (12).

5. The large Kaplan turbine runner crack repair device according to claim 1, characterized in that: Two linear guide rails (13) are longitudinally spaced on one side of the longitudinal seat (10) and the lifting seat (30). At least two sliders (14) are installed on each linear guide rail (13). The sliders (14) are guided and slidably installed on the linear guide rails (13), and the lifting seat (30) is installed on the sliders (14).

6. A large Kaplan turbine runner crack repair device according to claim 5, characterized in that: A slide plate (15) is installed on the slider (14), and the lifting seat (30) is installed on the slide plate (15) by bolts.

7. A large scale Francis turbine runner crack repair apparatus according to claim 6, characterized in that: Dustproof covers (16) are installed at the upper and lower ends of the longitudinal seat (10), and a bellows cover (17) is installed between the dustproof cover (16) and the slide plate (15). The upper and lower ends of the bellows cover (17) are bolted to the slide plate (15) and the dustproof cover (16) respectively.

8. The large Kaplan turbine runner crack repair device according to claim 7, characterized in that: Dustproof plates (18) are installed on the left and right sides of the slide plate (15), the dustproof plates (18) cover the slider (14), and the upper and lower ends of the dustproof plates (18) are bolted to the bellows cover (17).

9. The large Kaplan turbine runner crack repair apparatus of claim 1, wherein: A longitudinal groove (102) is provided on the side where the longitudinal seat (10) is connected to the lifting seat (30), and the driving device (40) is installed in the longitudinal groove (102).

10. The large Kaplan turbine runner crack repair device according to claim 1 or 9, characterized in that: The drive device (40) includes a driver (41), a ball screw (42), a coupling (43), and a screw nut (44). A mounting base (103) is fixed on the longitudinal seat (10). The driver (41) is mounted on the mounting base (103). One end of the ball screw (42) is connected to the longitudinal seat (10) through a bearing seat, and the other end is connected to the output shaft of the driver (41) through the coupling (43). A screw nut (44) is fixedly installed on the lifting seat (30). The ball screw (42) is arranged longitudinally, and the screw nut (44) is threadedly engaged with the ball screw (42). The driver (41) includes either a servo motor or a stepper motor.

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