Internal inspection robot for oil-immersed transformer

Abstract

The invention provides an oil-immersed transformer internal inspection robot. A top plate is fixed to one end of the top of a shell, and a bottom plate is fixed to one end of the bottom of the shell; a top horizontal propeller is mounted on one side of the middle of the top end of the top plate, and a top camera module is mounted on the other side; a vertical propeller is installed in the center of the bottom end of the bottom plate, a first bottom horizontal propeller and a second bottom horizontal propeller are symmetrically installed on the two sides of the vertical propeller, and a bottom camera module is installed in the middle of one side of the head of each of the first bottom horizontal propeller and the second bottom horizontal propeller; a plurality of ultrasonic ranging sensors are evenly distributed in the circumferential direction of the shell body, and the ultrasonic ranging sensors are matched with a depth sensor at the bottom and an inertia measurement unit in the shell body to jointly achieve the primary obstacle avoidance positioning function of the robot. The robot is small in size, high in maneuvering performance, good in passing ability and capable of well adapting to the complex environment in the transformer so that overhauling can be achieved under the condition that oil is not discharged or little oil is discharged, and the inspection efficiency and the equipment safety are improved.

Description

Technical Field

[0001] This invention relates to the field of underwater robot technology, specifically to an oil-immersed transformer internal inspection robot. Background Technology

[0002] The ability to efficiently, promptly, and accurately identify and repair transformer faults and defects is of great practical significance for the safe and stable operation of the power grid system.

[0003] In my country's power system, oil-immersed transformers are the primary type of main transformer. With the development of live-line detection and online monitoring technologies, various techniques such as fiber optic sensing, vibration monitoring, partial discharge detection, and dissolved gas analysis in the oil are employed to detect and monitor internal transformer defects. These methods have played a significant role in identifying latent defects and improving the safety and stability of equipment operation. However, regardless of the monitoring and detection techniques used to discover internal transformer defects, or after a transformer failure such as winding insulation failure, phase-to-phase or turn-to-turn discharge, or lead-to-ground discharge, a final inspection of the transformer's internal structure is still necessary. Currently, fault detection in oil-immersed transformers still primarily relies on personnel accessing the transformer through pre-designed maintenance access channels within the transformer housing. Traditional methods for detecting internal faults in oil-immersed transformers require draining the insulating oil from the transformer, leading to long inspection cycles, high maintenance costs, and the potential for equipment contamination due to improper oil handling, and even the introduction of new operational risks.

[0004] To address the aforementioned needs, an oil-immersed transformer internal inspection robot was designed, which is of great significance in replacing manual inspection of transformers when no oil is drained or only a small amount of oil is drained.

[0005] Currently, robots used for inspecting internal transformer equipment are also available, and their shapes are mostly spherical, biomimetic fish-shaped, horizontal cylindrical, or box-shaped. While these designs meet basic inspection function requirements to some extent, they have many limitations. For spherical structures: Spherical structures are known for their high flexibility and zero turning radius, allowing for agile movement in confined spaces, making them suitable for scenarios requiring frequent turning and multi-directional movement. However, spherical structures have low space utilization, making it difficult to accommodate a large number of inspection devices and tools, resulting in an inability to simultaneously optimize their size and performance, thus limiting their application in complex inspection tasks. For biomimetic fish-shaped structures: Biomimetic fish-shaped structures mimic the streamlined body of fish, possessing excellent hydrodynamic performance and enabling efficient swimming in water. Their tail and side fin designs provide good maneuverability and flexibility. However, the complex shape and large size of this structure limit its application in confined spaces. Bionic mechanisms must strictly adhere to biomechanical principles, leading to high complexity in design and manufacturing. Furthermore, biomimetic components, in order to meet streamlined and power requirements, are often large in size, making them poorly adaptable to space-constrained scenarios and difficult to access the confined areas inside transformers for inspection. For horizontal cylindrical structures: Horizontal cylindrical structures offer high internal space utilization, suitable for carrying various inspection equipment and tools, and can meet the needs of complex inspection tasks. However, their motion resistance is high, especially in oil-immersed environments. Cylindrical structures experience significant fluid resistance during movement, affecting the robot's motion efficiency and flexibility, increasing energy consumption and control difficulty, and limiting their motion performance inside oil-immersed transformers. For box-shaped structures: Box-shaped structures are a multifunctional and robust structural form, particularly suitable for applications requiring high internal space utilization and good protection performance. However, they also have disadvantages such as poor motion flexibility, poor hydrodynamic performance, large weight, and complex design and optimization. Especially in narrow or complex spaces, movement is restricted, fluid resistance is high, energy consumption is high, and the system load may increase, requiring complex custom designs to meet special environmental requirements.

[0006] In summary, while existing robots for inspecting internal transformer equipment meet basic inspection requirements to some extent, they have several limitations. First, their large size makes it difficult to access the narrower and more complex areas inside transformers, thus limiting the inspection range. Second, they lack flexibility and adaptability; faced with the intricate structure of transformers, these robots struggle to turn or adjust their posture flexibly and effectively avoid obstacles, increasing the difficulty and risk of operation. Furthermore, excessive compression or collisions in certain areas may damage delicate components inside the transformer. Therefore, designing a robot shape that better suits the complex environment inside transformers is crucial for improving inspection efficiency and equipment safety. Summary of the Invention

[0007] To address the problems of existing technologies, the purpose of this invention is to provide an oil-immersed transformer internal inspection robot. This robot is small in size, highly maneuverable, and has good maneuverability, enabling it to adapt well to the complex internal environment of transformers and perform maintenance even when the transformer has little or no oil draining. This replaces the manual internal inspection process of transformers, improving inspection efficiency and equipment safety.

[0008] To achieve the aforementioned technical features, the present invention aims to provide an oil-immersed transformer internal inspection robot, comprising a shell, a top plate fixed to one end of the shell, and a bottom plate fixed to one end of the shell; a top horizontal thruster is installed on one side of the top center of the top plate, and a top camera module is installed on the other side; a vertical thruster is installed at the center of the bottom end of the bottom plate, and a first bottom horizontal thruster and a second bottom horizontal thruster are symmetrically installed on both sides of the vertical thruster; a bottom camera module is installed at the middle of the head side of the first bottom horizontal thruster and the second bottom horizontal thruster; multiple ultrasonic ranging sensors are evenly distributed around the circumference of the shell, which, together with the depth sensor at the bottom and the inertial measurement unit inside the shell, jointly realize the robot's primary obstacle avoidance and positioning function.

[0009] Preferably, the shell body adopts a vertical cylindrical shape and a thin-walled cylindrical structure, with reinforcing ribs provided on the inner sidewall of the shell body, and a sensor mounting cavity for installing an ultrasonic ranging sensor is provided on the shell body.

[0010] Preferably, a radial sealing structure is provided between the shell body, the top plate, and the bottom plate, and is installed and fixed by bolts. The radial sealing structure includes sealing ring mounting grooves respectively provided on the outer circumference of the top plate and the bottom plate. A sealing element is installed inside the sealing ring mounting groove. The sealing element contacts the inner wall of the shell body for compression sealing, thereby forming a piston sealing groove type.

[0011] Preferably, the sealing element is a silicone O-ring.

[0012] Preferably, the top horizontal thruster, vertical thruster, first bottom horizontal thruster, and second bottom horizontal thruster all adopt the same structure; the top horizontal thruster includes a thruster body, a tail support is installed at one end of the thruster body, a head support is provided at one end of the thruster body, and a propeller is installed on the output shaft of the propeller motor inside the thruster body, with the propeller located inside the head support; the four sets of thrusters enable the robot to move flexibly and be precisely controlled in transformer oil.

[0013] Preferably, the top camera module and the bottom camera module adopt the same structure. The top camera module includes an adjustment motor, the output shaft of which is connected to the input end of a gear transmission box. An output shaft is installed at the output end of the gear transmission box and is connected to the camera housing. A camera is installed inside the camera housing through a transparent lens. A lampshade is installed on the other side of the camera housing. The other side of the lampshade is rotatably supported on a column through a support shaft. An LED light is installed inside the lampshade.

[0014] Preferably, the gear transmission box includes a driving gear installed at the end of the output shaft, the driving gear meshing with an intermediate gear, the intermediate gear meshing with a driven gear installed on the output shaft, a box cover installed on the outside of the gear transmission box, and a triangular fixing bracket provided on the outer wall of the gear transmission box.

[0015] Preferably, the interior of the housing also houses a battery, a main control board, and an attitude sensor, which are fixed by bolt holes, acrylic sheets, and fiber tape. Preferably, the inner surface of the base plate has reserved mounting interfaces for multiple key components, including a first motor ESC, a first LED driver board, a battery charging port, a debugging interface, and a switch; the base plate is provided with a ribbed structure, and a depth sensor is installed on the base plate to measure the distance between the robot and the bottom of the transformer, providing necessary data support for the robot's hovering and vertical movement.

[0016] Preferably, the surface of the top plate is provided with mounting interfaces for the second motor ESC, the second LED light driver board, and the communication radio module; the top of the top plate is provided with a Y-shaped mounting groove, and the top horizontal pusher and the top camera module are respectively installed inside the Y-shaped mounting groove.

[0017] Preferably, the wiring interfaces of the shell, top plate, and bottom plate of the internal inspection robot adopt a double-layer sealing structure. At the wiring hole position, a blind hole type terminal is used. The terminal penetrates through the shell to realize the internal and external connection of the electrical circuit. The double-layer sealing structure includes an epoxy resin sealing layer on the outer wall of the shell and a silicone sealing layer on the inner wall of the shell.

[0018] Preferably, the epoxy resin sealing layer is formed by pre-reserving an epoxy resin potting groove on the outer wall of the housing. During installation, epoxy resin is poured into the epoxy resin potting groove and cured to form a strong protective layer, effectively preventing oil from penetrating into the housing.

[0019] Preferably, the silicone sealing layer is formed by pre-reserving a potting groove in the inner wall of the housing for filling with sealing silicone. During installation, the silicone is poured into the epoxy resin potting groove, and after curing, it forms a strong protective layer that effectively prevents oil from penetrating into the housing.

[0020] The present invention has the following beneficial effects: 1. The robot of this invention is small in size, highly maneuverable, and has good maneuverability. It can adapt well to the complex internal environment of transformers to carry out maintenance when the transformer is not drained or drained with little oil, thereby replacing the manual internal inspection process of transformers, improving inspection efficiency and equipment safety.

[0021] 2. Given that transformer interiors often consist of narrow, vertical passages, internal inspection robots require high maneuverability and ease of operation. This invention's vertical cylindrical configuration perfectly adapts to these narrow passages, giving the robot excellent maneuverability. Secondly, the vertical cylindrical configuration also possesses excellent turning characteristics, enabling in-situ turning through appropriate power arrangement and control. Compared to the spherical configuration, which also has in-situ turning capability, the vertical cylindrical configuration's multi-directional maneuver control algorithms (horizontal, vertical, and rotational) are easier to implement. Finally, the vertical cylindrical configuration facilitates a larger deviation between the center of gravity and the center of buoyancy, improving the internal inspection robot's anti-tipping ability, providing greater static stability, and facilitating precise motion control.

[0022] 3. The oil-immersed transformer internal inspection robot used in this invention provides a device placement and fixing approach that can efficiently utilize the robot's internal space, arrange the various components closely and reasonably, and ensure that more functional modules, such as high-definition cameras and temperature sensors, are integrated within a limited volume to meet the diverse needs of oil-immersed transformer internal inspection.

[0023] 4. The oil-immersed transformer internal inspection robot used in this invention provides a structural approach to improve the heat dissipation performance of heat-generating devices, and provides a better heat dissipation path for heat-generating devices.

[0024] 5. The oil-immersed transformer internal inspection robot used in this invention provides a structural approach that utilizes reinforcing ribs to improve the strength of the robot's shell, achieving a dual optimization of strength and internal space utilization.

[0025] 6. The structural design method of the oil-immersed transformer internal inspection robot adopted in this invention can improve the inspection efficiency of transformers, reduce manpower, material resources and time costs, and reduce risks. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Figure 1 This is a first-person 3D view of the robot of the present invention.

[0028] Figure 2 This is a two-dimensional view of the robot of the present invention from a second perspective.

[0029] Figure 3 This is a 3D view of the robot from the third perspective of the present invention.

[0030] Figure 4 This is a 3D view of the robot from the fourth perspective of the present invention.

[0031] Figure 5 This is the front view of the robot of the present invention.

[0032] Figure 6 The machine of the present invention Figure 5 AA view.

[0033] Figure 7 This is a first-view 3D diagram of the top horizontal thruster of the present invention.

[0034] Figure 8 This is a two-dimensional view of the top horizontal thruster of the present invention from a second perspective.

[0035] Figure 9 This is a first-view 3D diagram of the top camera module of the present invention.

[0036] Figure 10 This is a two-dimensional view of the top camera module of the present invention from a second perspective.

[0037] Figure 11 This is a 3D view of the top camera module of the present invention after removing the cover, lampshade and transparent lens.

[0038] Figure 12 This is a three-dimensional view of the base plate of the present invention from a first perspective.

[0039] Figure 13 This is a two-dimensional view of the base plate of the present invention from a second perspective.

[0040] Figure 14 This is a three-dimensional view of the top plate of the present invention from a first perspective.

[0041] Figure 15 This is a three-dimensional view of the top plate of the present invention from a second perspective.

[0042] Figure 16 This is a top view of the present invention.

[0043] Figure 17 For the present invention Figure 16 BB view.

[0044] In the diagram: 1. Shell; 2. Top plate; 3. Top horizontal thruster; 4. Y-shaped mounting slot; 5. Top camera module; 6. Ultrasonic ranging sensor; 7. First bottom horizontal thruster; 8. Bottom plate; 9. Second bottom horizontal thruster; 10. Bottom camera module; 11. Vertical thruster; 12. Battery; 13. Main control board; 14. Sealing element; 15. Sealing ring mounting slot; 16. Switch; 17. First LED light driver board; 18. Battery charging port; 19. First motor ESC; 20. Debugging interface; 21. Second motor ESC; 22. Second LED light driver board; 23. Depth sensor; 24. Rib structure; 25. Silicone sealing layer; 26. Epoxy resin sealing layer; 27. Wiring terminal. Reinforcing rib 101, sensor mounting cavity 102; Head support 301, propeller 302, thruster body 303, tail support 304; Adjustment motor 501, output shaft 502, gear transmission box 503, triangular fixing bracket 504, box cover 505, transparent lens 506, camera housing 507, lampshade 508, column 509, support shaft 510, camera 511, LED light 512, driving gear 513, driven gear 514, intermediate gear 515, output shaft 516. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1: See Figure 1-17 This embodiment provides an oil-immersed transformer internal inspection robot, including a shell 1. A top plate 2 is fixed to one end of the top of the shell 1, and a bottom plate 8 is fixed to one end of the bottom. A top horizontal thruster 3 is installed on one side of the top center of the top plate 2, and a top camera module 5 is installed on the other side. A vertical thruster 11 is installed at the center of the bottom end of the bottom plate 8. A first bottom horizontal thruster 7 and a second bottom horizontal thruster 9 are symmetrically installed on both sides of the vertical thruster 11. A bottom camera module 10 is installed at the middle of the head side of the first bottom horizontal thruster 7 and the second bottom horizontal thruster 9. Multiple ultrasonic ranging sensors 6 are evenly distributed around the circumference of the shell 1. Together with the depth sensor 23 at the bottom and the inertial measurement unit inside the shell, they jointly realize the robot's primary obstacle avoidance and positioning function. This robot is small in size, highly maneuverable, and has good passability. It can adapt well to the complex environment inside the transformer to realize maintenance when the transformer is not drained or has little oil drained, thereby replacing the manual transformer internal inspection process, improving inspection efficiency and equipment safety.

[0047] Furthermore, the shell 1 adopts a vertical cylindrical configuration and a thin-walled cylindrical structure. Reinforcing ribs 101 are provided on the inner wall of the shell 1, and a sensor mounting cavity 102 for mounting the ultrasonic ranging sensor 6 is provided on the shell 1. The shell 1 is designed to adapt well to the narrow vertical passages inside the transformer, requiring the internal inspection robot to possess flexible maneuverability and ease of operation. Therefore, the vertical cylindrical configuration in this application perfectly adapts to the narrow vertical passages inside the transformer, giving the robot excellent passability. Secondly, the vertical cylindrical configuration also has excellent turning characteristics; with appropriate power arrangement and control, it can achieve on-the-spot turning. Compared to the spherical configuration, which also has on-the-spot turning capability, the horizontal, vertical, and rotational multi-directional maneuver control algorithms of the vertical cylindrical configuration are easier to implement. Finally, the vertical cylindrical configuration makes it easier to achieve a larger deviation between the center of gravity and the center of buoyancy, improving the internal inspection robot's anti-tipping ability, providing greater static stability, and facilitating precise motion control.

[0048] Furthermore, a radial sealing structure is provided between the shell 1, the top plate 2, and the bottom plate 8, and is installed and fixed by bolts. The radial sealing structure includes sealing ring mounting grooves 15 respectively disposed on the outer circumference of the top plate 2 and the bottom plate 8. A sealing element 14 is installed inside the sealing ring mounting groove 15. The sealing element 14 contacts the inner wall of the shell 1 and compresses to form a piston sealing groove. The above-mentioned radial sealing structure ensures a good sealing effect and improves the durability and reliability of the robot in an oil immersion environment. In the specific installation process, the sealing element 14 is first installed inside the sealing ring mounting groove 15 of the top plate 2 and the bottom plate 8, and then the top plate 2 and the bottom plate 8 are installed at the two ends of the shell 1 respectively, and then pressure is applied to the sealing element 14 to compress and seal it.

[0049] Furthermore, the sealing element 14 is a silicone O-ring. It possesses excellent oil resistance, chemical corrosion resistance, and good temperature resistance, enabling it to adapt to the high-temperature and chemically corrosive environment that may exist inside the transformer. Simultaneously, this sealing element also possesses sufficient elasticity and resilience, tending to return to its original shape when deformed under external force, thereby generating an automatic clamping force effect. This ensures that it can effectively fill gaps after being compressed, achieving good sealing performance, and quickly returns to its original shape after pressure release to maintain a long-term sealing effect.

[0050] Furthermore, the top horizontal thruster 3, the vertical thruster 11, the first bottom horizontal thruster 7, and the second bottom horizontal thruster 9 all adopt the same structure. The top horizontal thruster 3 includes a thruster body 303, a tail support 304 installed at one end of the thruster body 303, a head support 301 installed at one end of the thruster body 303, and a propeller 302 installed on the output shaft of the propeller motor inside the thruster body 303. The propeller 302 is located inside the head support 301. These four sets of thrusters enable the robot to move flexibly and be precisely controlled within the transformer oil. The specific structure of the thrusters described above provides power to the robot, allowing it to move within the transformer oil and precisely move to the required location for inspection.

[0051] Furthermore, the top camera module 5 and the bottom camera module 10 adopt the same structure. The top camera module 5 includes an adjustment motor 501, the output shaft 502 of which is connected to the input end of a gear transmission box 503. An output shaft 516 is installed at the output end of the gear transmission box 503, and the output shaft 516 is connected to a camera housing 507. A camera 511 is installed inside the camera housing 507 through a transparent lens 506. A lampshade 508 is installed on the other side of the camera housing 507, and the other side of the lampshade 508 is rotatably supported on a column 509 through a support shaft 510. An LED light 512 is installed inside the lampshade 508. Through the above-mentioned camera module, this module has the functions of automatic focus, image stabilization, brightness adjustment, and viewing angle adjustment from -40° to 90°, ensuring that clear images can be obtained even in low light conditions. At the same time, four ultrasonic ranging sensors evenly distributed along the circumference of the housing, together with the depth sensor at the bottom and the inertial measurement unit inside the housing, jointly realize the robot's basic obstacle avoidance and positioning function.

[0052] Furthermore, the gear transmission box 503 includes a driving gear 513 mounted on the end of the output shaft 502. The driving gear 513 meshes with an intermediate gear 515, and the intermediate gear 515 meshes with a driven gear 514 mounted on the output shaft 516. A cover 505 is mounted on the outside of the gear transmission box 503, and a triangular fixing bracket 504 is provided on the outer wall of the gear transmission box 503. Through the aforementioned gear transmission box 503, the power of the adjusting motor 501 can be output to the camera housing 507, thereby driving the camera housing 507 to rotate to adjust the camera angle to adapt to the inspection needs of different positions.

[0053] Furthermore, the interior of the housing 1 also houses a battery 12, a main control board 13, and an attitude sensor. The battery 12, main control board 13, and attitude sensor are secured using bolt holes, acrylic sheets, and fiber tape. This installation method fully utilizes the internal space of the housing 1, resulting in a more rational and compact structure.

[0054] Furthermore, the inner surface of the base plate 8 has reserved mounting interfaces for several key components, including a first motor ESC 19, a first LED driver board 17, a battery charging port 18, a debugging interface 20, and a switch 16; the base plate 8 is provided with a rib structure 24, and a depth sensor 23 is installed on the base plate 8 and used to measure the distance between the robot and the bottom of the transformer, providing necessary data support for the robot's hovering and vertical movement.

[0055] Furthermore, the surface of the top plate 2 is provided with mounting interfaces for the second motor ESC 21, the second LED light driver board 22, and the communication radio module; a Y-shaped mounting groove 4 is provided on the top of the top plate 2, and the top horizontal pusher 3 and the top camera module 5 are respectively installed inside the Y-shaped mounting groove 4. The Y-shaped mounting groove 4 can effectively protect the top horizontal pusher 3 and the top camera module 5 inside.

[0056] Furthermore, the wiring interfaces of the internal inspection robot's housing 1, top plate 2, and bottom plate 8 all employ a double-layer sealing structure. At the wiring hole locations, blind-hole terminals 27 are used, penetrating the housing to achieve internal and external electrical circuit connections. The double-layer sealing structure includes an epoxy resin sealing layer 26 on the outer wall of the housing and a silicone sealing layer 25 on the inner wall. The double-layer sealing design of the internal inspection robot's wiring interfaces prevents oil ingress and ensures the safety of electrical connections, aiming to guarantee reliability and durability in transformer oil-immersion environments.

[0057] Furthermore, the epoxy resin sealing layer 26 is achieved by pre-drilling epoxy resin potting grooves on the outer wall of the housing. During installation, epoxy resin is poured into the epoxy resin potting grooves, and after curing, it forms a robust protective layer that effectively prevents oil from penetrating into the housing. The epoxy resin sealing layer 26 described above provides a very good sealing effect.

[0058] Furthermore, the silicone sealing layer 25 is achieved by pre-reserving a potting groove in the inner wall of the housing for filling with sealing silicone. During installation, the silicone is poured into the epoxy resin potting groove, and after curing, it forms a robust protective layer that effectively prevents oil from seeping into the housing. The silicone sealing layer 25 described above provides a very good sealing effect.

[0059] Example 2: This invention provides an overall design concept for an internal inspection robot for oil-immersed transformers: I. The overall concept or most critical technical idea of ​​this plan: Given that transformer interiors are mostly narrow, vertical passages, internal inspection robots require high mobility and ease of operation. A vertical cylindrical configuration perfectly adapts to these narrow passages, giving the robot excellent maneuverability. Secondly, the vertical cylindrical configuration also offers excellent turning characteristics; with appropriate power arrangement and control, it can achieve turning on the spot. Compared to a spherical configuration, which also has the ability to turn on the spot, the vertical cylindrical configuration's multi-directional (horizontal, vertical, and rotational) maneuver control algorithms are easier to implement. Finally, the vertical cylindrical configuration makes it easier to achieve a larger deviation between the center of gravity and the center of buoyancy, improving the robot's anti-tipping ability, providing greater static stability, and facilitating precise motion control.

[0060] The entire internal inspection robot shell consists of three parts: a top plate, a bottom plate, and a shell body. Figure 1-4 As shown, the internal inspection robot is equipped with four sets of propulsion devices on its exterior, including one set of horizontal thrusters at the top, two sets of horizontal thrusters at the bottom, and one set of vertical thrusters. This configuration allows the robot to move flexibly and be precisely controlled in transformer oil. In addition, camera modules integrating cameras and lighting devices are mounted at the top and bottom of the robot's shell. These modules feature automatic focus, image stabilization, brightness adjustment, and an adjustable viewing angle from -40° to 90°, ensuring clear images even in low-light conditions. Simultaneously, four ultrasonic ranging sensors evenly distributed along the circumference of the shell, along with a depth sensor at the bottom and an inertial measurement unit inside the shell, collectively enable the robot's basic obstacle avoidance and positioning functions.

[0061] II. Steps of specific embodiments of the present invention: 1. Shell structure design: An overall cross-sectional view of the internal inspection robot is shown below. Figure 6 As shown, the shell design of the oil-immersed transformer internal inspection robot consists of three main parts: a top plate, a bottom plate, and a shell body. These components together constitute the robot's main structure, ensuring its stable operation in the complex environment inside the transformer.

[0062] The internal inspection robot's shell and top plate utilize advanced manufacturing processes, combining CNC machining and 3D printing technology. This process first uses 3D printing to create thin-walled reinforcing rib structures for the components, aiming to reduce weight while maintaining structural strength. Subsequently, these thin-walled components are connected to the main load-bearing parts using precision welding technology, ensuring the overall structural robustness and reliability.

[0063] Internal inspection robot base plate structure design as follows Figure 12-13As shown, the base plate surface is carefully designed with pre-installed mounting interfaces for several key components, including motor ESCs, LED driver boards, battery charging ports, debugging interfaces, and switches. These interfaces are designed to optimize space utilization while ensuring convenient installation and maintenance of all components.

[0064] In the design of the base plate, heat-generating components such as the motor ESC and LED driver board are intentionally placed on the base plate surface. This layout facilitates effective heat dissipation, thus solving potential overheating problems. By attaching these components to the base plate surface, the large surface area of ​​the base plate can be utilized to improve heat dissipation efficiency, ensuring the robot's thermal stability during long-term operation. Furthermore, the base plate features a ribbed structure, a design that serves a dual purpose. First, the ribbed structure significantly enhances the mechanical strength of the base plate, enabling it to withstand internal hydraulic pressure and external loads without deformation. Second, these structures increase the surface area of ​​the base plate, further improving heat dissipation efficiency and helping to maintain the robot's internal electronic components within a suitable temperature range.

[0065] The base plate also integrates the mounting position of a depth sensor, which is crucial for the robot's precise positioning inside the transformer. By accurately measuring the distance between the robot and the bottom of the transformer, the depth sensor provides the necessary data support for the robot's hovering and vertical movement.

[0066] The top plate of the internal inspection robot is designed similarly to the bottom plate, with pre-drilled interfaces on its surface for components such as motor ESCs, LED driver boards, and communication radio modules. Figure 14-15 As shown, heat-generating components such as the motor ESC, LED driver board, and communication radio module are attached to the surface of the housing, which facilitates heat dissipation.

[0067] The internal inspection robot's body is equipped with components such as a battery, main control board, ultrasonic ranging sensor, and attitude sensor. The ultrasonic ranging sensor is evenly distributed along the circumference. The battery, main control board, and attitude sensor are fixed by bolt holes, acrylic plates, and fiber tape.

[0068] The top plate, bottom plate, and body of the internal inspection robot are installed and fixed using bolts. Specifically, threaded holes are machined at the joints between the body and the top and bottom plates, while corresponding ordinary holes matching the size of the threaded holes are designed into the top and bottom plates. During assembly, bolts of appropriate specifications are selected, passed through the holes in the top or bottom plate, and screwed into the threaded holes in the body. Tightening the bolts ensures a secure connection between the components, thereby guaranteeing the stability and reliability of the overall structure of the internal inspection robot.

[0069] 2. Sealing structure design Cross-sectional view of the internal inspection robot as shown Figure 6As shown, propeller motors, camera modules, and other components are fixedly mounted on the top and bottom plates. These components transmit signals and are electrically connected to the control module inside the internal inspection robot via wiring interfaces on the top or bottom plate housing. Therefore, the sealing design of the internal inspection robot not only needs to ensure the structural sealing performance between the top and bottom plates and the housing, but also needs to focus on the sealing reliability of the wiring interfaces on the top and bottom plates. A good sealing design can improve the robot's durability and reliability in oil-immersion environments.

[0070] 2.1 Housing sealing design: like Figure 6 As shown, the sealing structure between the top plate and the housing of the internal inspection robot adopts a radial sealing piston groove type. This design aims to achieve a tight seal by embedding a sealing element with high mechanical strength, high elasticity, and strong resilience between the two contact surfaces. By compressing the sealing element, the existing gap between the two surfaces is filled, thereby significantly increasing the immersion pressure of the transformer oil and effectively preventing oil from penetrating into the housing through the gap.

[0071] Based on this sealing principle, a groove is specially designed in the top plate to embed an O-ring, thereby achieving radial sealing between the housing and the top plate. The radial sealing solution, rather than axial sealing, was chosen to maximize the internal usable space of the internal inspection robot while ensuring sealing performance, thus providing greater flexibility for the layout and operation of internal components.

[0072] The sealing structure between the bottom plate and the shell of the internal inspection robot is similar to that of the top plate. It also adopts a radial sealing piston sealing groove type, with grooves set and O-rings embedded to achieve radial sealing.

[0073] The selected sealing ring is a silicone O-ring, which possesses excellent oil resistance, chemical corrosion resistance, and good temperature resistance, enabling it to adapt to the high-temperature and chemically corrosive environment that may exist inside the transformer. Simultaneously, this sealing element also possesses sufficient elasticity and resilience, tending to return to its original shape when deformed under external force, thereby generating an automatic clamping force effect. This ensures that it can effectively fill gaps after being compressed, achieving excellent sealing performance, and quickly returns to its original shape after pressure release to maintain a long-term sealing effect.

[0074] 2.2 Sealing design of wire interface: like Figure 17 As shown, the sealing design of the internal inspection robot's through-line interface adopts a double-layer sealing structure to prevent oil seepage and ensure the safety of electrical connections, aiming to ensure reliability and durability in transformer oil immersion environment.

[0075] At the via locations, blind-hole terminals are used, penetrating the housing to achieve internal and external electrical wiring connections. To achieve the first layer of sealing, epoxy resin potting grooves are pre-drilled on the outer wall of the housing. During installation, epoxy resin is poured into these grooves, curing to form a robust protective layer that effectively prevents oil from seeping into the housing. To further enhance the sealing effect, potting grooves for filling with silicone sealant are also designed on the inner wall of the housing, forming a second layer of sealing. Silicone, as a flexible sealing material, can adapt to minor deformations that may occur in the housing, while providing additional leak-proof protection. This double-layer sealing design not only improves the reliability of the seal but also provides additional mechanical protection for the wiring interfaces.

[0076] The selected epoxy resin structural adhesive can bond a variety of materials, including glass, ceramics, metals, and many rigid plastics. Furthermore, epoxy resin adhesives are widely used for sealing power equipment such as transformers and instrument transformers. It can form a stable sealing structure in a short time, exhibiting excellent corrosion resistance and aging resistance. Simultaneously, this adhesive has good chemical compatibility with transformer oil, maintaining stable performance even after long-term exposure to transformer oil. Moreover, it possesses excellent electrical insulation properties, effectively preventing electric shock and short-circuit faults. The selected silicone is a de-alcoholized curing silicone structural adhesive, capable of reliably bonding to materials such as metals, plastics, ceramics, and glass. It has good flexibility, accommodating the thermal expansion and contraction of materials; it also possesses excellent chemical resistance, resisting the corrosion of various chemicals, including transformer oil. Furthermore, its excellent electrical insulation properties effectively prevent short circuits such as pin breakdown at connection interfaces, ensuring safe equipment operation.

[0077] Through this double-sealed design, the wire interface of the internal inspection robot can maintain a stable working state in the harsh environment inside the transformer, while ensuring the safe operation of the robot's internal electronic components, thereby extending the robot's service life and improving work efficiency.

[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An internal inspection robot for oil-immersed transformers, characterized in that, The shell (1) is fixed with a top plate (2) at one end and a bottom plate (8) at the other end. A top horizontal thruster (3) is installed on one side of the top of the top plate (2) and a top camera module (5) is installed on the other side. A vertical thruster (11) is installed at the center of the bottom of the bottom plate (8). A first bottom horizontal thruster (7) and a second bottom horizontal thruster (9) are symmetrically installed on both sides of the vertical thruster (11). A bottom camera module (10) is installed at the middle of the head side of the first bottom horizontal thruster (7) and the second bottom horizontal thruster (9). Multiple ultrasonic ranging sensors (6) are evenly distributed in the circumferential direction of the shell (1). Together with the depth sensor (23) at the bottom and the inertial measurement unit inside the shell, they jointly realize the robot's primary obstacle avoidance and positioning function.

2. The internal inspection robot for oil-immersed transformers according to claim 1, characterized in that, The shell (1) adopts a vertical cylindrical shape and a thin-walled cylindrical structure. The inner sidewall of the shell (1) is provided with reinforcing ribs (101), and the shell (1) is provided with a sensor mounting cavity (102) for mounting the ultrasonic ranging sensor (6).

3. The internal inspection robot for oil-immersed transformers according to claim 1, characterized in that, A radial sealing structure is provided between the shell (1), the top plate (2), and the bottom plate (8) and is installed and fixed by bolts. The radial sealing structure includes sealing ring mounting grooves (15) respectively provided on the outer circumference of the top plate (2) and the bottom plate (8). A sealing element (14) is installed inside the sealing ring mounting groove (15). The sealing element (14) contacts the inner wall of the shell (1) and compresses to seal, thereby forming a piston sealing groove.

4. The oil-immersed transformer internal inspection robot according to claim 3, characterized in that, The sealing element (14) is a silicone O-ring.

5. The internal inspection robot for oil-immersed transformers according to claim 1, characterized in that, The top horizontal thruster (3), vertical thruster (11), first bottom horizontal thruster (7), and second bottom horizontal thruster (9) all adopt the same structure; the top horizontal thruster (3) includes a thruster body (303), a tail bracket (304) is installed at one end of the tail of the thruster body (303), a head bracket (301) is provided at one end of the head of the thruster body (303), and a propeller (302) is installed on the output shaft of the propeller motor inside the thruster body (303), and the propeller (302) is located inside the head bracket (301); the four sets of thrusters enable the robot to move flexibly and be precisely controlled in transformer oil.

6. The internal inspection robot for oil-immersed transformers according to claim 1, characterized in that, The top camera module (5) and the bottom camera module (10) adopt the same structure. The top camera module (5) includes an adjustment motor (501). The output shaft (502) of the adjustment motor (501) is connected to the input end of the gear transmission box (503). The output end of the gear transmission box (503) is equipped with an output shaft (516). The output shaft (516) is connected to the camera housing (507). The camera (511) is installed inside the camera housing (507) through a transparent lens (506). A lampshade (508) is installed on the other side of the camera housing (507). The other side of the lampshade (508) is rotatably supported on the column (509) through a support shaft (510). An LED light (512) is installed inside the lampshade (508).

7. The internal inspection robot for an oil-immersed transformer according to claim 6, characterized in that, The gear transmission box (503) includes a drive gear (513) installed at the end of the output shaft (502). The drive gear (513) meshes with the intermediate gear (515) for transmission. The intermediate gear (515) meshes with the driven gear (514) installed on the output shaft (516). A box cover (505) is installed on the outside of the gear transmission box (503). A triangular fixing bracket (504) is provided on the outer wall of the gear transmission box (503).

8. The internal inspection robot for oil-immersed transformers according to claim 1, characterized in that, The shell (1) is also equipped with a battery (12), a main control board (13) and an attitude sensor. The battery (12), the main control board (13) and the attitude sensor are fixed by bolt fixing holes, acrylic plate and fiber tape.

9. The internal inspection robot for an oil-immersed transformer according to claim 1, characterized in that, The inner surface of the base plate (8) has reserved installation interfaces for several key components, including the first motor ESC (19), the first LED light driver board (17), the battery charging port (18), the debugging interface (20), and the switch (16); the base plate (8) is provided with a rib structure (24), and the depth sensor (23) is installed on the base plate (8) and used to measure the distance between the robot and the bottom of the transformer, providing necessary data support for the robot's hovering and vertical movement.

10. The internal inspection robot for an oil-immersed transformer according to claim 1, characterized in that, The surface of the top plate (2) is reserved with the installation interface for the second motor ESC (21), the second LED light driver board (22) and the communication radio module; the top of the top plate (2) is provided with a Y-shaped mounting groove (4), and the top horizontal pusher (3) and the top camera module (5) are respectively installed inside the Y-shaped mounting groove (4).

11. The internal inspection robot for an oil-immersed transformer according to claim 1, characterized in that, The wiring interfaces of the shell (1), top plate (2) and bottom plate (8) of the internal inspection robot are all sealed with a double-layer sealing structure. At the wiring hole position, a blind hole type terminal (27) is used. The terminal (27) penetrates the shell and realizes the internal and external connection of the electrical circuit. The double-layer sealing structure includes an epoxy resin sealing layer (26) located on the outer wall of the shell and a silicone sealing layer (25) located on the inner wall of the shell.

12. The internal inspection robot for an oil-immersed transformer according to claim 11, characterized in that, The epoxy resin sealing layer (26) is formed by pre-reserving an epoxy resin potting groove on the outer wall of the housing. During the installation process, the epoxy resin is poured into the epoxy resin potting groove and cured to form a strong protective layer, which effectively prevents oil from penetrating into the housing.

13. The internal inspection robot for an oil-immersed transformer according to claim 11, characterized in that, The silicone sealing layer (25) is formed by pre-reserving a potting groove in the inner wall of the housing for filling the sealing silicone. During the installation process, the silicone is poured into the epoxy resin potting groove and cured to form a strong protective layer, which effectively prevents oil from penetrating into the housing.

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