An underwater maintenance robot for nuclear power plants

Abstract

The invention discloses an underwater maintenance robot for a nuclear power plant, which includes a walking mechanism, a driving assembly, a box and a supporting mechanism; the box is provided with a closed internal space, the driving assembly is arranged in the internal space, and outputs power to the walking mechanism; the walking mechanism is connected to and drives the box to move; the supporting mechanism includes a bracket assembly, a rotating platform rotatably arranged above the bracket assembly, and a spring limiting structure; the bracket assembly is elastically mounted on the box through the spring limiting structure. The underwater maintenance robot for a nuclear power plant can carry an operating tool to complete the underwater maintenance or replacement of positioning pins, replacing manual maintenance or replacement operations, and avoiding radiation damage to maintenance personnel caused by underwater fuel assemblies.

Description

Technical Field

[0001] The invention relates to the field of robots, and in particular to an underwater maintenance robot for a nuclear power plant. Background Art

[0002] During the operation of a nuclear power plant, it is necessary to regularly inspect the equipment and components inside the reactor. One of the important tasks is to overhaul the upper reactor components.

[0003] When the nuclear reactor is in operation, the upper internals are installed above the fuel assemblies to provide a fixed and protective environment for the fuel assemblies. Fuel assembly locating pins are installed at the bottom of the upper internals. When installing the upper internals, the locating pins will be inserted into the locating pin holes of the upper tube holders of the fuel assemblies to prevent the fuel assemblies from being damaged due to violent vibrations during the operation of the reactor, thereby causing nuclear fuel leakage.

[0004] During long-term use, the positioning pins may crack due to high temperature, high pressure, high-speed water flow, etc., or bend due to improper operation during the installation of the equipment. If the cracks in the positioning pins are not discovered in time, the cracks will continue to expand during the operation of the nuclear reactor, eventually causing the positioning pins to break and form foreign matter, seriously endangering the safety of the nuclear reactor; the bending of the positioning pins due to external forces will cause the positioning pins to be unable to be inserted into the fuel assembly normally, causing the entire upper pile internal components to be unable to be properly positioned, thereby affecting the normal operation of the nuclear reactor, or carrying the fuel assembly when removing the upper pile internal components, endangering the safety of the fuel assembly. Therefore, during the maintenance of the nuclear power plant, it is necessary to inspect the positioning pins of the upper pile fuel assembly. If the positioning pins are found to have defects such as cracks or bends, they need to be further replaced. Due to long-term close contact with the fuel assembly, the surface irradiation dose of the upper pile internal components is very high. Therefore, during the maintenance of the upper pile internal components, they are placed on the support frame in the component pool, and the entire equipment is underwater to avoid damage to personnel or other equipment. Since the positioning pins are replaced in an underwater working environment and the components inside the pile have high radiation, it is not suitable for manual maintenance and replacement. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an underwater maintenance robot for a nuclear power plant in view of the prior art.

[0006] The technical solution adopted by the present invention to solve the technical problem is: an underwater maintenance robot for a nuclear power plant includes a walking mechanism, a driving assembly, a box body and a supporting mechanism;

[0007] The box body is provided with a closed internal space, the driving assembly is arranged in the internal space and outputs power to the walking mechanism; the walking mechanism is connected to and drives the box body to move;

[0008] The support mechanism comprises a bracket assembly, a rotating platform rotatably arranged above the bracket assembly, and a spring limiting structure; the bracket assembly is elastically mounted on the box body through the spring limiting structure.

[0009] Preferably, the bracket assembly includes a bracket, an upper plate, and a lower plate; the upper plate is connected to the upper end of the bracket, and the upper plate is installed above the box body through the spring limiting structure; the lower plate is connected to the lower end of the bracket, and the lower plate is located below the box body.

[0010] Preferably, the spring limiting structure includes a plurality of springs fixedly arranged between the upper plate and the box body; when the springs are pressed on the rotating platform and are in a compression limit position, the lower plate is supported on the ground.

[0011] Preferably, the upper plate includes a plurality of universal bearings disposed on the upper portion and connected to the rotating platform, for supporting and stabilizing the rotating platform.

[0012] Preferably, the traveling mechanism comprises a crawler traveling mechanism, a dynamic sealing device, and a transmission mechanism for transmitting power of the driving assembly; the driving assembly drives the crawler traveling mechanism to rotate through the transmission mechanism; the transmission mechanism is arranged through the box body, and the dynamic sealing device is provided at the passing position.

[0013] Preferably, the rotating platform includes a platform assembly for supporting a tool, a rotating shaft assembly connected to the platform assembly and driving the platform assembly to rotate, and a rotating drive assembly connected to the rotating shaft assembly to drive the rotating shaft assembly to rotate.

[0014] Preferably, the rotating shaft assembly comprises a positioning shaft fixed on the box or bracket assembly, a bearing, and a rotating shaft rotatably mounted on the positioning shaft via the bearing; the rotating shaft is fixedly connected to the platform assembly.

[0015] Preferably, the rotary drive assembly comprises a third drive device fixed above the upper plate, a bevel gear, a worm wheel, a worm, and a support column; the worm is installed above the upper plate through the support column; the worm wheel is fixed to the upper plate and connected to the rotating shaft;

[0016] The third driving device drives the worm to rotate through the bevel gear, and then the worm drives the worm wheel to rotate, and the worm wheel drives the rotating shaft to rotate.

[0017] Preferably, the platform assembly includes a Y-moving platform; the Y-moving platform includes a Y-platform support plate, an X-platform support plate, and a Y-direction guide assembly for driving the X-platform support plate to move in the Y direction, which are located above the rotating shaft and fixedly connected;

[0018] The X-platform support plate is located above the Y-platform support plate and is connected via the Y-direction guide assembly;

[0019] The Y-direction guide assembly includes a second driving device fixed above the Y-platform support plate and used to provide Y-direction movement power, a second bevel gear, a second ball screw, a second guide rail, and a second slider;

[0020] The second driving device drives the second ball screw to rotate through the second bevel gear; the second ball screw is connected to and drives the second slider to move in the Y direction on the second guide rail;

[0021] The second guide rail is fixed above the Y platform support plate, and the second slider is fixed below the X platform support plate and installed on the second guide rail.

[0022] Preferably, the platform assembly includes an X-moving platform; the X-moving platform includes a work support plate for carrying tools, and an X-direction guide assembly for driving the work support plate to move in the X direction;

[0023] The work support plate is located above the X-platform support plate and is connected via the X-direction guide assembly;

[0024] The work support plate includes a first driving device fixed above the X-platform support plate and used to provide X-direction movement power, a first bevel gear, a first ball screw, a first guide rail, and a first slider;

[0025] The first driving device drives the first ball screw to rotate through the first bevel gear; the first ball screw is connected to and drives the first slider to move in the X direction on the first guide rail;

[0026] The first guide rail is fixed above the X-platform support plate, and the first sliding block is fixed below the work support plate and installed on the first guide rail.

[0027] The implementation of the present invention has the following beneficial effects: the underwater maintenance robot of a nuclear power plant can be equipped with working tools and move in coordination with the working tasks, and can be used to replace manual work to complete the maintenance and replacement of the positioning pins of the internal components of the reactor, thereby avoiding harm to the human body caused by the radiation environment during the maintenance and replacement work. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

[0029] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

[0030] Figure 2It is a front view providing a schematic diagram of the structure in an embodiment of the present invention;

[0031] Figure 3 is a top view of a schematic diagram of a structure provided in an embodiment of the present invention;

[0032] Figure 4 It is a side view of a structural schematic diagram provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] like Figure 1-4 As shown, it is an embodiment of an underwater maintenance robot for a nuclear power plant of the present invention, and the underwater maintenance robot for a nuclear power plant may include a walking mechanism, a driving assembly, a box 6, a supporting mechanism and a remote control device; a closed internal space is provided in the box 6 for placing the driving assembly. The driving assembly is connected to the walking mechanism for providing power to the walking mechanism. The walking mechanism is connected to the box 6 for driving the movement of the box 6 and providing support for the box 6. The supporting mechanism includes a bracket assembly, a spring limiting structure 4 and a rotating platform; the bracket assembly is connected to the box 6 through the spring limiting structure 4; the rotating platform is connected to the bracket assembly, located above the bracket assembly, and is used to carry working tools for operation. The remote control device is placed in the box 6 for remote control in the operation room. It can be understood that its internal space can be of regular shape or irregular shape.

[0034] In some embodiments, the driving assembly may include a power supply and a motor reducer. The power supply is used to provide a power source for the underwater maintenance robot of the nuclear power plant. A quick plug interface is provided on the power supply, and the motor reducer is connected to the power supply through a quick plug connector to provide power for the movement of the box 6.

[0035] like Figure 2 As shown, in some embodiments, the walking mechanism may include a transmission mechanism, a dynamic sealing device, and a crawler walking structure. The transmission mechanism passes through the box 6, one end is connected to the motor reducer, and the other end is connected to the crawler walking mechanism, which is used to transmit power to the crawler walking mechanism. The crawler walking mechanism is installed on both sides of the box 6 to drive the box 6 to move. The dynamic sealing device is installed at the position where the transmission mechanism passes through the box 6, and is used to seal the position where the transmission mechanism passes through the box 6. It can be understood that the underwater maintenance robot of the nuclear power plant needs two crawler walking mechanisms to walk, and each crawler walking mechanism needs two dynamic sealing devices.

[0036] Furthermore, in some other embodiments, a wheeled walking mechanism or other forms of walking mechanisms may also be used.

[0037] In some embodiments, the transmission mechanism includes a transmission shaft and a driving wheel. One end of the transmission shaft is connected to the motor reducer, and the other end is connected to the driving wheel. The power of the motor reducer is transmitted to the driving wheel through the transmission shaft.

[0038] like Figure 4 As shown, in some embodiments, the crawler walking mechanism may include a driven wheel 1, a crawler 21, etc. The crawler 21 is installed on the driven wheel 1, and the driven wheel 1 is connected to the driving wheel. The driving wheel rotates to drive the driven wheel 1 to rotate, and then drives the crawler 21 to move. During the movement, the speed of the crawlers 21 on both sides is controlled to form a speed difference, so as to complete the steering of the vehicle body.

[0039] like Figure 2 As shown, in some embodiments, the box 6 may include a wire hole, a drag chain, an upper cover plate and a through hole. The wire hole is located at the rear end of the box 6 and is used for routing when the external drive device is connected to the power supply. The drag chain is fixed to the side of the wire hole at the rear end of the box 6 and is used to place external cables to support the rotating platform to have sufficient cable margin during rotation or movement. A through hole is provided at the center of the box 6 for positioning the rotating platform. The upper cover plate is detachably fixed to the top of the box 6 and is used to inspect or replace the drive assembly in the box 6. A circular hole is opened at the center of the upper cover plate corresponding to the through hole, and a rubber ring is installed between the upper cover plate and the box 6 for sealing; an O-ring is installed at the matching position of the circular hole and the through hole for sealing.

[0040] like Figure 3 As shown, in some embodiments, the bracket assembly may include a bracket 5, an upper plate 9 and a lower plate 7. The bracket 5 includes four columns for providing support for the rotating platform. The length of the column is greater than the height of the box 6. The specific length can refer to the maximum downward movement distance of the spring limiting structure 4. The columns are respectively arranged at the four corners of the box 6. The upper plate 9 is fixedly connected to the lower plate 7 through the columns, and the middle is hollow. The box 6 is placed in the hollow position of the bracket 5. The upper plates 9 are connected to the box 6 through the spring limiting structure 4. There is a certain distance between the lower plate 7 and the ground, which is slightly smaller than the downward movement distance of the spring limiting structure 4. When the rotating platform is loaded, the spring limiting structure 4 is in a compressed state, and the spring limiting structure 4 moves downward due to the pressure, and the lower plate 7 also moves downward; when the spring limiting structure 4 is compressed and in the limit position, the lower plate 7 is supported on the ground to disperse the pressure through a larger contact surface.

[0041] It can be understood that in other embodiments, the four columns can also be replaced by two steel plates with a certain thickness to connect the upper plate 9 and the lower plate 7.

[0042] like Figure 3As shown, the spring limiting structure 4 includes a plurality of springs in some embodiments. The upper plate 9 is connected to the box body 6 by installing four springs. It can be understood that the number of springs can be adjusted according to actual use requirements.

[0043] like Figure 2-3 As shown, in some embodiments, the upper plate 9 includes a plurality of universal bearings 15 disposed above the upper plate 9, the bottom end of the universal bearing 15 is fixed above the upper plate 9, and the rotatable end is connected to the rotating platform to support and stabilize the rotating platform. It can be understood that the number of universal bearings 15 can be selected according to the weight of the rotating platform and the working tool.

[0044] like Figure 2 As shown, in some embodiments, the rotating platform includes a rotating shaft assembly, a platform assembly, and a rotating drive assembly. One end of the rotating shaft assembly is connected to the platform assembly for transmitting power to the platform assembly to drive the platform assembly to rotate; the other end is connected to the rotating drive assembly. The platform assembly is used to support the working tool. The rotating drive assembly drives the rotating shaft assembly to rotate, thereby driving the platform assembly to rotate.

[0045] like Figure 2 As shown, in some embodiments, the rotating shaft assembly may include a positioning shaft 8, a bearing and a rotating shaft. The positioning shaft 8 may be fixedly mounted in the through hole of the box body 6 to serve as the rotation axis. It can be understood that the positioning shaft 8 may also be directly mounted on the bracket assembly to serve as the rotation axis.

[0046] The bearing is fixedly installed in the positioning shaft 8. One end of the rotating shaft is rotatably installed on the top of the positioning shaft 8 through the bearing; the other end of the rotating shaft is fixedly connected to the platform assembly, and the rotating shaft is driven to rotate by the rotating drive assembly, and the platform assembly is driven to rotate by the rotating shaft.

[0047] like Figure 3 As shown, in some embodiments, the rotary drive assembly may include a third drive device 11, a bevel gear set 12, a worm wheel, a worm, and two support columns. The third drive device 11 drives the bevel gear set 12 to rotate, thereby driving the worm to rotate, and then driving the worm wheel to rotate. The third drive device 11 is fixed above the upper plate 9.

[0048] like Figure 3 As shown, in some embodiments, the third drive device 11 may include a third waterproof motor housing, a third motor reducer, and a third dynamic sealing device. The third motor reducer is installed in the third waterproof motor housing, and the shaft end extends from the third waterproof motor housing. The third dynamic sealing device and the O-ring are used to form a seal at the extended position of the shaft end. The power cord of the third motor reducer is connected to the power supply in the box body 6 through the wire hole position, and the connection method adopts a quick plug-in connection. The wire position of the third waterproof motor housing is sealed with an O-ring.

[0049] The bevel gear set 12 includes a first bevel gear and a second bevel gear that are meshed. The first bevel gear is mounted on the shaft end of the third reducer extending out of the third waterproof motor housing. The second bevel gear is mounted on one end of the worm.

[0050] The worm is fixed on the upper plate 9 through two support columns and is driven to rotate by the second bevel gear. The worm wheel is fixedly connected to the rotating shaft and is driven to rotate by the worm. The support column can also be a solid cube, and the bearing is directly welded to the cube.

[0051] like Figure 2 As shown, in some embodiments, the platform assembly includes a Y mobile platform, an X mobile platform, and a butt-welding flange; the Y mobile platform is connected to the rotating shaft through the butt-welding flange; the X mobile platform is located above the Y mobile platform and is movably connected to the Y mobile platform.

[0052] The butt-welded flange includes a first flange and a second flange; the first flange is fixedly welded to the top of the Y movable platform, and the second flange is fixedly welded to the top of the rotating shaft, and the butt-welded flanges are connected by bolts and nuts. When the rotating shaft rotates, the Y movable platform is driven to rotate.

[0053] like Figure 2 As shown, in some embodiments, the Y-moving platform may include a Y-platform support plate 17, an X-platform support plate 16, and a Y-direction guide assembly. The X-platform support plate 16 is located above the Y-platform support plate 17 and is connected to the Y-platform support plate 17 through the Y-direction guide assembly. The X-platform support plate 16 can move in the Y direction above the Y-platform support plate 17.

[0054] like Figure 3 As shown, in some embodiments, the Y-direction guide assembly may include a second drive device 2, a second bevel gear, a second ball screw, a second guide rail, and a second slider. The second drive device 2 drives the second bevel gear, and the second bevel gear drives the second ball screw to rotate, thereby driving the second slider to move on the second guide rail.

[0055] like Figure 2-3 As shown, in some embodiments, the second drive device 2 is fixedly installed above the Y platform support plate 17. The second drive device 2 may include a second waterproof motor housing, a second motor reducer, and a second dynamic sealing device. The second motor reducer is installed in the second waterproof motor housing, and the shaft end extends from the second waterproof motor housing. The second dynamic sealing device and the O-ring are used to form a seal at the extended position of the shaft end. The power cord of the second motor reducer is connected to the power supply in the box body 6 through the wire hole position, and the connection method adopts a quick plug-in connection. The wire position of the second waterproof motor housing is sealed with an O-ring.

[0056] like Figure 2As shown, in some embodiments, the X-moving platform may include a work support plate 18 and an X-direction guide assembly. The work support plate 18 is located above the X-platform support plate 16 and is connected to the X-platform support plate 16 through the X-direction guide assembly. It can be understood that the work support plate 18 can move in the X direction above the X-platform support plate 16.

[0057] like Figure 3 As shown, in some embodiments, the X-direction guide assembly may include a first drive device 20, a first bevel gear, a first ball screw, a first guide rail, and a first slider. The first drive device 20 drives the first bevel gear to rotate, the first bevel gear drives the first ball screw to rotate, and then drives the first slider to move on the first guide rail.

[0058] like Figure 2-3 As shown, in some embodiments, the first drive device 20 is fixedly installed above the X-platform support plate 16. The first drive device 20 may include a first waterproof motor housing, a first motor reducer, and a first dynamic sealing device. The first motor reducer is installed in the first waterproof motor housing, and the shaft end extends from the first waterproof motor housing. The first dynamic sealing device and the O-ring are used to form a seal at the extended position of the shaft end. The power cord of the first motor reducer is connected to the power supply in the box body 6 through the wire hole position, and the connection method adopts a quick plug-in connection. It can be understood that the wire position of the first waterproof motor housing is sealed with an O-ring.

[0059] like Figure 2 As shown, in some embodiments, the remote control device may include a lower computer, an upper computer, a control cabinet, and an operating table. The lower computer is placed in a box 6 for remote control. The upper computer is installed in the control cabinet, and the motor cable and the motor driver signal line enter the box 6 from the outside through a waterproof connector installed on the box 6 to connect with the lower computer. The lower computer then communicates with the upper computer in the control cabinet on land through a composite line composed of a cable, a network cable, and a signal line on the box 6, so that the upper computer controls its motion.

[0060] like Figure 2 As shown, when assembling the underwater maintenance robot for a nuclear power plant, the drive assembly, the remote control device, the transmission mechanism and the dynamic sealing device can be installed in the box 6 first, and the walking mechanism is connected to the transmission mechanism. After installation, the upper cover plate is locked; then the bracket 5 is connected to the box 6 through the spring limit structure 4; and then the rotating platform is installed above the bracket 5.

[0061] When the underwater maintenance robot of the nuclear power plant is in operation, the power in the box 6 is first turned on remotely. According to the task requirements, the upper computer sends the corresponding instructions to the lower computer. The lower computer operates according to the instructions, and controls the movement of the crawler 21 and the movement of the rotating platform to achieve the purpose of accurately moving the working tool. During the operation, the operator can control the movement of the crawler 21 walking mechanism through the driving component to realize the movement and rotation of the box 6; the third driving device 11 controls the rotation of the rotating platform to drive the working tool to rotate. During the overall rotation process, the overall rotation range of ±45° can be achieved, and the rotation accuracy can reach 0.5°; the second driving device 2 controls the X platform support plate 16 to move in the Y direction, thereby driving the working tool to move in the Y direction through the working support plate 18, and the movable distance is plus or minus 75mm, and the accuracy is less than 0.04mm; the first driving device 20 controls the working support plate 18 to move in the X direction, thereby driving the working tool on the working support plate 18 to move in the Y direction, and the movable distance is plus or minus 75mm, and the accuracy is less than 0.04mmmm. The underwater maintenance robot of the nuclear power plant is fully sealed and waterproof, and can work normally at 15 meters underwater. It can also withstand a cumulative radiation dose of more than 10 5 Gy.

[0062] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. For ordinary technicians in this field, without departing from the concept of the present invention, the above features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. An underwater maintenance robot for a nuclear power plant, characterized in that: It comprises a walking mechanism, a driving assembly, a box (6) and a supporting mechanism; The box (6) is provided with a sealed internal space, the driving component is arranged in the internal space and outputs power to the walking mechanism; the walking mechanism is connected to and drives the box (6) to move; The support mechanism comprises a support assembly, a rotating platform rotatably arranged above the support assembly, and a spring limiting structure (4); the support assembly is elastically mounted on the box body (6) via the spring limiting structure (4); The bracket assembly comprises a bracket (5), an upper plate (9), and a lower plate (7); the upper plate (9) is connected to the upper end of the bracket (5), and the upper plate (9) is installed above the box (6) through the spring limiting structure (4); the lower plate (7) is connected to the lower end of the bracket (5), and the lower plate (7) is located below the box (6); The spring limiting structure (4) comprises a plurality of springs fixedly arranged between the upper plate (9) and the box body (6); when the springs are pressed into a compression limit position on the rotating platform, the lower plate (7) is supported on the ground.

2. The underwater maintenance robot for a nuclear power plant according to claim 1, characterized in that: The upper plate (9) comprises a plurality of universal bearings (15) arranged on the upper portion and connected to the rotating platform, and used for supporting and stabilizing the rotating platform.

3. The underwater maintenance robot for a nuclear power plant according to claim 2, characterized in that: The traveling mechanism comprises a crawler traveling mechanism, a dynamic sealing device, and a transmission mechanism for transmitting power of the driving assembly; the driving assembly drives the crawler traveling mechanism to rotate through the transmission mechanism; the transmission mechanism is arranged through the box body (6), and the dynamic sealing device is provided at the passing position.

4. The underwater maintenance robot for a nuclear power plant according to claim 3, characterized in that: The rotating platform includes a platform component for supporting a tool, a rotating shaft component connected to the platform component and driving the platform component to rotate, and a rotating driving component connected to the rotating shaft component and driving the rotating shaft component to rotate.

5. The underwater maintenance robot for a nuclear power plant according to claim 4, characterized in that: The rotating shaft assembly comprises a positioning shaft (8) fixed on the box (6) or the bracket assembly, a bearing, and a rotating shaft rotatably mounted on the positioning shaft via the bearing; the rotating shaft is fixedly connected to the platform assembly.

6. The underwater maintenance robot for a nuclear power plant according to claim 5, characterized in that: The rotary drive assembly comprises a third drive device (11) fixed above the upper plate (9), a bevel gear (12), a worm wheel, a worm, and a support column; the worm is mounted above the upper plate (9) via the support column; the worm wheel is fixed to the upper plate (9) and connected to the rotary shaft; The third driving device (11) drives the worm to rotate via the bevel gear (12), and then the worm drives the worm wheel to rotate, and the worm wheel drives the rotating shaft to rotate.

7. The underwater maintenance robot for a nuclear power plant according to claim 6, characterized in that: The platform assembly includes a Y mobile platform; The Y-moving platform comprises a Y-platform support plate (17) located above the rotating shaft and fixedly connected, an X-platform support plate (16), and a Y-direction guide assembly for driving the X-platform support plate (16) to move in the Y direction; The X-platform support plate (16) is located above the Y-platform support plate (17) and is connected via the Y-direction guide assembly; The Y-direction guide assembly comprises a second drive device (2) fixed above the Y-platform support plate (17) and used to provide Y-direction movement power, a second bevel gear, a second ball screw, a second guide rail, and a second slide block; The second driving device (2) drives the second ball screw to rotate via the second bevel gear; the second ball screw is connected to and drives the second slider to move in the Y direction on the second guide rail; The second guide rail is fixed above the Y platform support plate (17), and the second sliding block is fixed below the X platform support plate (16) and mounted on the second guide rail.

8. The underwater maintenance robot for a nuclear power plant according to claim 7, characterized in that: The platform assembly includes an X mobile platform; The X-moving platform comprises a work support plate (18) for carrying tools, and an X-direction guide assembly for driving the work support plate (18) to move in the X-direction; The work support plate (18) is located above the X-platform support plate (16) and is connected via the X-direction guide assembly; The work support plate (18) comprises a first drive device (20) fixed above the X-platform support plate and used for providing X-direction movement power, a first bevel gear, a first ball screw, a first guide rail, and a first slider; The first driving device (20) drives the first ball screw to rotate via the first bevel gear; the first ball screw is connected to and drives the first slider to move in the X direction on the first guide rail; The first guide rail is fixed above the X-platform support plate (16), and the first sliding block is fixed below the work support plate (18) and mounted on the first guide rail.

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