A surface detection device for a water-erosion-resistant coating of a last-stage blade of a steam turbine

Abstract

The utility model relates to the technical field of coating detection, and disclose a kind of turbine last stage blade anti-erosion coating surface detection device, including base, the upper surface of base is fixedly connected with linear slide rail, slidingly connected with mobile sliding platform on linear slide rail, the upper surface of mobile sliding platform is fixedly connected with multi-degree-of-freedom robot arm, and CCD camera is detachably connected on the end base of multi-degree-of-freedom robot arm by bolt, the upper surface of base and located linear slide rail one side position fixedly connected with two supports, the opposite side of two the support is rotatably connected with chucking carousel, the utility model is used in cooperation with driving motor by sliding multi-degree-of-freedom robot arm, turbine last stage blade is rotated in detection process, realizes the overall scanning of blade surface by CCD camera, not only will detection time be greatly shortened, guarantee the consistency and reliability of detection result.

Description

Technical Field

[0001] This utility model relates to the field of coating inspection technology, and more specifically to a device for inspecting the surface of a waterproof and corrosion-resistant coating on the last stage blades of a steam turbine. Background Technology

[0002] Steam turbines are core power equipment in thermal power generation, nuclear power generation and other fields. Their efficiency and reliability are of paramount importance. The long blades of the last stage work in the high temperature and high pressure wet steam zone. Their blade tip linear velocity is extremely high. The high-speed moving blades will "cut" the water droplets, resulting in severe water droplet erosion on the back arc side of the blade inlet. This erosion will destroy the blade profile, increase surface roughness, and lead to a decrease in aerodynamic efficiency. More seriously, it will weaken the blade substrate and may cause fatigue cracks or even blade breakage. The coating itself will also gradually suffer from wear, peeling, microcracks and other damage under long-term harsh operating conditions.

[0003] Regularly inspecting the coating condition and assessing its health is of great significance for predicting the remaining life of the blades, avoiding unplanned downtime, and ensuring the safe and economical operation of the unit.

[0004] A search revealed a Chinese patent with publication number CN208937540U, which discloses a non-destructive testing device for steam turbine blades. This device enables automated testing and unloading of steam turbine blades, reducing labor costs and preventing significant economic losses caused by unit downtime due to blade breakage. However, during testing, the steam turbine blades are fixed to the device, which limits the observation angle and field of view, making it difficult to cover all curved surfaces of the blades and thus compromising the reliability of the test results. Utility Model Content

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a surface inspection device for the waterproof corrosion coating of the last stage blade of a steam turbine, so as to solve the problems existing in the background art.

[0006] This utility model provides the following technical solution: a surface inspection device for waterproof and corrosion-resistant coating of turbine last-stage blades, comprising a base, a linear slide rail fixedly connected to the upper surface of the base, a movable slide table slidably connected to the linear slide rail, a multi-degree-of-freedom robotic arm fixedly connected to the upper surface of the movable slide table, a CCD camera detachably connected to the end base of the multi-degree-of-freedom robotic arm by bolts, two supports fixedly connected to the upper surface of the base and located on one side of the linear slide rail, and a clamping turntable rotatably connected to the opposite sides of the two supports, a drive motor fixedly connected to one side of one of the supports to rotate the corresponding clamping turntable axially, a clamping component one for fixing the root of the turbine last-stage blade on one side of the clamping turntable, and a clamping component two for fixing the tip of the turbine last-stage blade on one side of the other clamping turntable.

[0007] As a further embodiment of this utility model, the clamping assembly includes a lower clamping block fixedly connected to one side of the clamping turntable connected to the drive motor. A clamping frame is inserted through and slidably connected to the lower clamping block. A block is fixedly connected to one side of the clamping turntable. A locking screw is rotatably connected to the upper surface of the clamping frame through a bearing seat. The top end of the locking screw passes through the block and is threadedly connected to the block through a threaded cylinder.

[0008] As a further embodiment of this utility model, the upper surface of the lower clamping block and the upper surface of the clamping frame are both provided with contour grooves that are the same shape as the root of the last stage blade of the steam turbine, and the edges of the two contour grooves are integrally formed with protrusions.

[0009] As a further embodiment of this utility model, the contour groove on the lower clamping block and the clamping frame, as well as the protrusion on the edge of the contour groove, completely wraps the blade root of the last stage blade of the steam turbine.

[0010] As a further embodiment of this utility model, the clamping assembly two includes a support frame fixedly connected to one side of another clamping turntable. Two linkage sliders are slidably connected inside the support frame via sliding sleeves. Bidirectional synchronous screws are rotatably connected to the inner walls of both sides of the support frame via bearing seats. The bidirectional synchronous screws pass through the two linkage sliders and are threadedly connected to the linkage sliders via threaded cylinders. A contact clamp is fixedly connected to one side of each of the two linkage sliders.

[0011] As a further embodiment of this utility model, each of the two contact plates has a groove at one end of its opposite side that matches the curved surface of the end of the turbine's last-stage blade.

[0012] As a further embodiment of this utility model, a cavity is provided on the linear slide rail, and a ball screw linear module for moving the movable slide table along the linear slide rail is fixedly connected in the cavity.

[0013] As a further embodiment of this utility model, rubber pads are adhered to the inner wall of both the contour groove and the recess.

[0014] The technical effects and advantages of this utility model are as follows:

[0015] 1. This utility model uses a sliding multi-degree-of-freedom robotic arm and a drive motor in combination to rotate the last-stage turbine blades during the inspection process, enabling the CCD camera to perform a comprehensive scan of the blade surface. This not only significantly shortens the inspection time but also ensures the consistency and reliability of the inspection results.

[0016] 2. This utility model achieves a unique bidirectional fixing design at both ends of the "root-body" through clamping component one and clamping component two, ensuring that the long blade will not vibrate or shift during the rotation scanning process, which not only protects the valuable blade from clamping damage, but also provides a stable foundation for high-precision image acquisition.

[0017] 3. The detection process after clamping of this utility model does not require manual intervention, realizing automated scanning of the detection process, replacing the inefficient traditional method that relies on technicians to use handheld equipment and visual judgment, and eliminating subjective judgment errors due to human differences. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the lower clamping block and clamping frame structure of this utility model.

[0020] Figure 3 This is a schematic diagram of the support frame structure of this utility model.

[0021] Figure 4 This is a structural diagram of the last stage blade of the steam turbine of this utility model.

[0022] The attached diagram is labeled as follows: 1. Base; 2. Linear slide rail; 3. Moving slide table; 4. Cavity; 5. Ball screw linear module; 6. Multi-degree-of-freedom robotic arm; 7. CCD camera; 8. Support; 9. Clamping turntable; 10. Drive motor; 11. Lower clamping block; 12. Clamping frame; 13. Block; 14. Locking screw; 15. Contouring groove; 16. Support frame; 17. Bidirectional synchronous screw; 18. Linkage slider; 19. Contact clamping plate; 20. Groove. Detailed Implementation

[0023] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. This utility model is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] Reference Figures 1-4This utility model provides a surface inspection device for the waterproof and erosion-resistant coating of the last stage blades of a steam turbine, including a base 1. A linear slide rail 2 is bolted to the upper surface of the base 1. A movable slide 3 is slidably connected to the linear slide rail 2. A multi-degree-of-freedom robotic arm 6 (model: SNAM7300 robotic arm) is bolted to the upper surface of the movable slide 3. A CCD camera 7 is detachably connected to the end base of the multi-degree-of-freedom robotic arm 6 by bolts. A bolt is also bolted to the upper surface of the base 1, located on one side of the linear slide rail 2. Two supports 8 are provided, and clamping turntables 9 are rotatably connected to opposite sides of the two supports 8. One side of one support 8 is fixedly connected by bolts to a drive motor 10 that rotates the corresponding clamping turntable 9 axially. One side of the clamping turntable 9 is provided with a clamping assembly 1 for fixing the root of the last stage blade of the steam turbine, and the other side of the clamping turntable 9 is provided with a clamping assembly 2 for fixing the end of the last stage blade of the steam turbine. A cavity 4 is provided on the linear slide rail 2, and a ball screw linear module 5 that moves the movable slide table 3 along the linear slide rail 2 is fixedly connected to the cavity 4 by bolts.

[0025] It should be noted that the ball screw linear module 5 achieves precise linear motion through the coordinated operation of various components: the slide table is the moving part, the ball screw and guide rail form the transmission core, the motor and coupling provide power, and the aluminum alloy profile and support base ensure structural stability. Furthermore, by cooperating with magnetic switches, proximity switches, or photoelectric switches, the displacement of the slide table can be precisely controlled. Those skilled in the art can set it according to actual needs, which will not be elaborated here.

[0026] A CCD camera is a digital camera that uses a charge-coupled device (CCD) as an image sensor. Therefore, a CCD camera converts the optical scene into a digital image signal and outputs a raw pixel matrix, which is then used in conjunction with subsequent software algorithms to achieve image recognition.

[0027] It should be noted that the drive motor 10 is existing technology, which is a servo motor with an encoder. The number of rotations and rotation angle of the motor output shaft are controllable and have high precision. Those skilled in the art can set it according to actual needs, which will not be elaborated here.

[0028] After the turbine's last-stage blades are clamped, the drive motor 10 starts, causing the clamping turntable 9 and the fixed blades to rotate slowly and uniformly around its axis. At the same time, the ball screw linear module 5 works, driving the movable slide table 3 and its multi-degree-of-freedom robotic arm 6 to perform precise linear motion along the linear slide rail 2.

[0029] According to the preset program, the multi-degree-of-freedom robotic arm 6 continuously adjusts the spatial attitude and angle of the CCD camera 7. The two motions of blade rotation and robotic arm linear motion are combined to enable the motion trajectory of the CCD camera 7 relative to the blade surface to cover the entire complex three-dimensional curved surface of the blade, realizing automated spiral scanning of the blade surface. During the scanning process, the high-resolution CCD camera 7 continuously acquires high-definition images of the anti-corrosion coating on the blade surface and detects defects such as microcracks, peeling, holes and erosion pits on the surface of the turbine's last stage blade.

[0030] By using a sliding multi-degree-of-freedom robotic arm 6 in conjunction with a drive motor 10, the turbine's last-stage blades are rotated during the inspection process, enabling the CCD camera 7 to perform a comprehensive scan of the blade surface. This not only significantly shortens the inspection time but also ensures the consistency and reliability of the inspection results.

[0031] In this utility model, the clamping assembly includes a lower clamping block 11 that is fixedly connected to one side of the clamping turntable 9 connected to the drive motor 10 by bolts. A clamping frame 12 is slidably connected through the lower clamping block 11. A block 13 is fixedly connected to one side of the clamping turntable 9 by bolts. A locking screw 14 is rotatably connected to the upper surface of the clamping frame 12 through a bearing seat. The top end of the locking screw 14 passes through the block 13 and is threadedly connected to the block 13 through a threaded cylinder.

[0032] Furthermore, the upper surface of the lower clamping block 11 and the upper surface of the clamping bracket 12 are both provided with contoured grooves 15 that are the same shape as the root of the last stage blade of the steam turbine. The edges of the two contoured grooves 15 are integrally formed with protrusions, and the blade root is completely wrapped by the contoured grooves 15 and their protrusions, providing rigid locking.

[0033] Furthermore, the contour groove 15 on the lower clamping block 11 and the clamping bracket 12, as well as the protrusion on the edge of the contour groove 15, completely wrap the blade root of the last stage blade of the steam turbine. Rubber pads are adhered to the inner wall of both the contour groove 15 and the groove 20.

[0034] First, the operator places the turbine's last-stage blade to be inspected between two clamping turntables 9. The blade root is placed in the contour groove 15 of the lower clamping block 11 of the clamping assembly. Then, the locking screw 14 is rotated, causing the clamping frame 12 to move downward and cooperate with the lower clamping block 11. Through the two mutually fitting contour grooves 15 and their protrusions, the blade root is completely wrapped and firmly fixed.

[0035] In this utility model, the clamping assembly 2 includes a support frame 16 that is fixedly connected to one side of another clamping turntable 9 by bolts. Two linkage sliders 18 are slidably connected inside the support frame 16 by a sliding sleeve. Two bidirectional synchronous screws 17 are rotatably connected to the inner walls of both sides of the support frame 16 by bearing seats. The bidirectional synchronous screws 17 pass through the two linkage sliders 18 and are threadedly connected to the linkage sliders 18 by a threaded cylinder. One side of each of the two linkage sliders 18 is fixedly connected to a contact clamping plate 19 by bolts.

[0036] In this application, the inner wall of the threaded cylinder on the block 13 and the linkage slider 18 is provided with an annular groove in the axial direction. A nylon 66 damping ring with a Shore hardness of 85A is embedded in the groove. The continuous axial clamping force generated by its elastic deformation forms a helical angle interference fit of 15°-20° with the surfaces of the locking screw 14 and the bidirectional synchronous screw 17, respectively. When the threaded pair is subjected to axial vibration load, the nylon insert can generate a maximum elastic compression of 0.3mm, which increases the friction coefficient between the thread contact surfaces from 0.15 to 0.68 (tested according to ASTM D1894 standard), effectively suppressing the loosening displacement caused by thread springback.

[0037] The unique bidirectional fixing design at both ends of the "root-body" structure, achieved through clamping component one and clamping component two, ensures that the long blade will not vibrate or shift during the rotational scanning process. This protects the valuable blade from clamping damage and provides a stable foundation for high-precision image acquisition.

[0038] Furthermore, each of the two contact clamps 19 has a groove 20 at one end of its opposite side that matches the curved surface of the turbine's last-stage blade. The blade end is flexibly clamped by the contact clamps 19 with the groove 20, perfectly fitting the curved surface.

[0039] The blade tip is placed between two contact plates 19 of the clamping assembly 2. By turning the bidirectional synchronous screw 17, the two linkage sliders 18 are driven to move the contact plates 19 toward each other until their grooves 20 fit tightly against the curved surface of the blade, thereby gently and stably clamping the blade tip from both sides.

[0040] The inspection process after clamping is completed requires no manual intervention, realizing automated scanning of the inspection process. This replaces the inefficient traditional method that relies on technicians holding equipment and making judgments by eye, eliminating subjective judgment errors caused by human factors.

[0041] The use of this utility model involves the following steps:

[0042] S1: First, the operator places the turbine last-stage blade to be inspected between two clamping turntables. The blade root is placed in the contour groove 15 of the lower clamping block 11 of the clamping assembly. Then, the locking screw 14 is rotated to move the clamping frame 12 downward and cooperate with the lower clamping block 11. Through the two mutually fitting contour grooves 15 and their protrusions, the blade root is completely wrapped and firmly fixed.

[0043] S2: The blade tip is placed between the two contact plates 19 of the clamping assembly 2. By turning the bidirectional synchronous screw 17, the two linkage sliders 18 are driven to move the contact plates 19 toward each other until their grooves 20 fit tightly against the curved surface of the blade, thereby gently and stably clamping the blade tip from both sides.

[0044] S3: After the turbine's last stage blades are clamped, the drive motor 10 starts, driving the clamping turntable 9 and the fixed blades to rotate slowly and uniformly around its axis. At the same time, the ball screw linear module 5 works, driving the moving slide 3 and its multi-degree-of-freedom robotic arm 6 to perform precise linear motion along the linear guide rail 2.

[0045] S4: According to the preset program, the robotic arm 6 continuously adjusts the spatial attitude and angle of the CCD camera 7. The two motions of blade rotation and robotic arm linear movement are combined to enable the motion trajectory of the CCD camera 7 relative to the blade surface to cover the entire complex three-dimensional curved surface of the blade, realizing automated spiral scanning of the blade surface. During the scanning process, the high-resolution CCD camera 7 continuously acquires high-definition images of the anti-corrosion coating on the blade surface and detects defects such as microcracks, peeling, holes and erosion pits on the surface of the turbine's last stage blade.

[0046] Finally, the following points should be noted: In the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection" and "linkage" should be interpreted broadly, and can be mechanical or electrical connection, or internal connection between two components, or direct connection. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may change.

[0047] The electronic components and modules used in this utility model can all be parts that are commonly used in the market and can achieve the specific functions in this case. The specific models and sizes can be selected and adjusted according to actual needs.

[0048] The accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

Claims

1. A device for inspecting the surface of a waterproof and erosion-resistant coating on the last stage blades of a steam turbine, comprising a base (1), characterized in that: A linear slide rail (2) is fixedly connected to the upper surface of the base (1). A movable slide (3) is slidably connected to the linear slide rail (2). A multi-degree-of-freedom robotic arm (6) is fixedly connected to the upper surface of the movable slide (3). A CCD camera (7) is detachably connected to the end base of the multi-degree-of-freedom robotic arm (6) by bolts. Two brackets (8) are fixedly connected to the upper surface of the base (1) and to one side of the linear slide rail (2). A clamping turntable (9) is rotatably connected to the opposite side of the two brackets (8). A drive motor (10) is fixedly connected to one side of one of the brackets (8) to rotate the corresponding clamping turntable (9) axially. A clamping component one for fixing the root of the last stage blade of the steam turbine is provided on one side of the clamping turntable (9). A clamping component two for fixing the end of the last stage blade of the steam turbine is provided on the other side of the clamping turntable (9).

2. The device for detecting the surface of the waterproof corrosion coating on the last stage blades of a steam turbine according to claim 1, characterized in that: The clamping assembly includes a lower clamping block (11) fixedly connected to one side of the clamping turntable (9) connected to the drive motor (10). A clamping frame (12) is inserted through and slidably connected to the lower clamping block (11). A block (13) is fixedly connected to one side of the clamping turntable (9). A locking screw (14) is rotatably connected to the upper surface of the clamping frame (12) through a bearing seat. The top end of the locking screw (14) passes through the block (13) and is threadedly connected to the block (13) through a threaded cylinder.

3. The device for detecting the surface of the waterproof corrosion coating on the last stage blades of a steam turbine according to claim 2, characterized in that: The upper surface of the lower clamping block (11) and the upper surface of the clamping frame (12) are both provided with contour grooves (15) that are the same shape as the root of the last stage blade of the steam turbine. The edges of the two contour grooves (15) are integrally formed with protrusions.

4. The device for detecting the surface of the waterproof and erosion-resistant coating on the last stage blades of a steam turbine according to claim 3, characterized in that: The contoured groove (15) on the lower clamp (11) and the clamp (12), as well as the protrusion on the edge of the contoured groove (15), completely wrap the root of the turbine's last stage blade.

5. The device for detecting the surface of the waterproof corrosion coating on the last stage blades of a steam turbine according to claim 1, characterized in that: The second clamping assembly includes a support frame (16) fixedly connected to one side of another clamping turntable (9). Two linkage sliders (18) are slidably connected inside the support frame (16) via a sliding sleeve. Two bidirectional synchronous screws (17) are rotatably connected to the inner walls of both sides of the support frame (16) via bearing seats. The bidirectional synchronous screws (17) pass through the two linkage sliders (18) and are threadedly connected to the linkage sliders (18) via a threaded cylinder. One side of each of the two linkage sliders (18) is fixedly connected to a contact clamp (19).

6. The device for detecting the surface of the waterproof corrosion coating on the last stage blades of a steam turbine according to claim 5, characterized in that: The two contact plates (19) are provided with grooves (20) at one end of opposite sides that match the curved surface of the end blade of the last stage of the steam turbine.

7. The device for detecting the surface of the waterproof corrosion coating on the last stage blades of a steam turbine according to claim 1, characterized in that: The linear slide rail (2) has a cavity (4), and a ball screw linear module (5) is fixedly connected in the cavity (4) to move the movable slide (3) along the linear slide rail (2).

8. The device for detecting the surface of the waterproof and erosion-resistant coating on the last stage blades of a steam turbine according to claim 3, characterized in that: Rubber pads are adhered to the inner walls of both the contour groove (15) and the groove (20) on one side.

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