Underwater rotary jet cleaning device and underwater robot

Abstract

The invention belongs to the field of underwater cleaning equipment, and particularly relates to an underwater rotary jet cleaning device and an underwater robot. In order to improve the self-stability of the cleaning device, the underwater rotary jet cleaning device comprises an impeller with a mounting hole in the rear end, and the mounting hole is used for being connected with a mechanical arm internally provided with a flow channel to form a water inlet hole; a first cavitation nozzle for spraying forwards is arranged on the front end surface of a blade of the impeller, and a flow channel communicated with the water inlet hole and the first cavitation nozzle is arranged in the impeller; when in use, the blades are driven by the mechanical arm to rotate and drive environmental water flow to flow backwards so as to balance backward recoil force applied to the blades by the first cavitation spray head. The invention further provides an underwater robot applying the underwater rotary jet cleaning device. According to the underwater rotary jet cleaning device, the impeller rotates actively, so that the force of environmental water flow on the impeller is utilized to balance the recoil force generated when the cavitation nozzle sprays, and the self-stability of the underwater rotary jet cleaning device is improved.

Description

Technical Field

[0001] This invention belongs to the field of underwater cleaning equipment, and in particular relates to an underwater rotating jet cleaning device and an underwater robot. Background Technology

[0002] With the continuous development and utilization of marine resources, the number of underwater structures is increasing, including subsea oil and gas pipelines, submarine cables, offshore platforms, and underwater pipelines. Due to the complexity of the marine environment, underwater structures are prone to various damages and defects caused by marine life or natural disasters. Therefore, regular inspection and maintenance of underwater structures are necessary. During inspection and maintenance, it is essential to clean the surfaces of underwater structures of any adhering objects (marine organisms or silt, etc.).

[0003] To clean the surface of underwater structures, Chinese utility model patent with authorization announcement number CN223221703U and authorization announcement date of August 15, 2025 discloses a cleaning device and an underwater cleaning robot. In this underwater cleaning robot, a cavitation gun can be moved by a robotic arm, and a high-pressure water source is introduced into the cavitation gun. The water reaches the cavitation nozzle through the outlet of the cavitation gun, and after being cavitated by the cavitation nozzle, it is sprayed onto the surface of the object to be cleaned, so as to clean the object to be cleaned.

[0004] In the solution disclosed in the aforementioned Chinese utility model patent, water sprayed out through the cavitation nozzle will exert a large recoil force on the cavitation nozzle. This recoil force is transmitted to the robotic arm through the cavitation gun, which will cause the robotic arm to swing unnecessarily, and in turn cause the cavitation nozzle to swing unnecessarily, affecting the cleaning effect.

[0005] Chinese invention patent with authorization announcement number CN110340062B and authorization announcement date of May 10, 2024 discloses a cavitation jet underwater net cleaning robot. The cleaning robot includes a flow guide shroud, which is provided with a nozzle mounting hole and a flow guide hole for installing a cavitation nozzle. The nozzle mounting hole and the flow guide hole are inclined in opposite directions.

[0006] When using the aforementioned cleaning robot, high-pressure water is sprayed forward through cavitation nozzles. The water flow exerts a recoil force on the cavitation nozzles, which drives the guide shroud to rotate and also drives it to move backward. As the guide shroud rotates, ambient water flows through the guide holes to the rear of the guide shroud, thus exerting a forward thrust on it. This thrust is greater than the recoil force, causing the guide shroud to adhere to the net.

[0007] When using the above scheme to balance the recoil force of water flow on the cavitation nozzle, the object to be cleaned must be permeable to water (e.g., through the mesh of the mesh) to avoid the formation of extremely high positive pressure between the guide shield and the surface of the object to be cleaned due to the fluid ejected from the cavitation nozzle. At the same time, the water flow on the opposite side of the mesh (the object to be cleaned) can flow through the mesh into the guide hole to ensure that the thrust is greater than the recoil force.

[0008] However, the above solution cannot be used when the surface of the object to be cleaned is impermeable to water. Therefore, there is still a technical problem where the robotic arm swings unnecessarily due to recoil force. Summary of the Invention

[0009] The purpose of this invention is to provide an underwater rotating jet cleaning device to solve the technical problem that the robotic arm and cavitation nozzle oscillate abnormally due to the backlash force of the water flow on the cavitation nozzle when the surface of the object to be cleaned is impermeable to water.

[0010] Another objective of this invention is to provide an underwater robot to solve the same technical problems mentioned above.

[0011] To achieve the above objectives, the technical solution of the underwater rotating jet cleaning device provided by the present invention is as follows: An underwater rotating jet cleaning device includes an impeller with a mounting hole at its rear end. The rotation axis of the mounting hole coincides with the rotation axis of the impeller, and the mounting hole is used to connect with a robotic arm with an internal flow channel to form a water inlet. The front end face of the impeller blades is provided with a first cavitation nozzle for spraying forward to clean the surface of an object. The impeller is provided with a flow channel connecting the water inlet and the first cavitation nozzle. When in use, the blades are used to rotate under the drive of the robotic arm and drive the ambient water flow backward to balance the backward recoil force exerted by the first cavitation nozzle on the blades.

[0012] Furthermore, the rear end face of the blade is provided with a self-cleaning nozzle for spraying obliquely backward to clean the connection between the impeller and the robotic arm. The spray pressure of the self-cleaning nozzle is less than the spray pressure of the first cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet hole and the self-cleaning nozzle.

[0013] Furthermore, the self-cleaning nozzle is a second cavitation nozzle.

[0014] Furthermore, the rear end face of the blade is provided with a balancing nozzle for spraying backward to cooperate with the blade and balance the recoil force. The spray pressure of the balancing nozzle is less than the spray pressure of the first cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet hole and the balancing nozzle.

[0015] Furthermore, the impeller is a hollow impeller, and the hollow part of the hollow impeller forms a flow channel for connecting the water inlet hole and each nozzle.

[0016] Furthermore, the nozzle of the first cavitation nozzle is positioned facing directly forward.

[0017] Furthermore, the mounting hole is a threaded hole, and the direction of the female thread of the threaded hole satisfies the following: when the robotic arm drives the impeller to rotate so that the blades drive the ambient water flow backward, the male thread of the robotic arm and the female thread of the threaded hole tend to continue to tighten, so as to avoid the robotic arm from disengaging from the impeller.

[0018] Furthermore, the blades are provided with threaded holes at the corresponding positions of the first cavitation nozzles, and the first cavitation nozzles are connected to a throat tube with corresponding threads, so that the first cavitation nozzles and the blades are threadedly connected.

[0019] Furthermore, the impeller surface is coated with a waterproof coating to mitigate seawater corrosion.

[0020] The beneficial effects of the underwater rotating jet cleaning device provided by this invention are as follows: When cleaning the surface of an object using the underwater rotating jet cleaning device of this invention, the water flow (which may contain detergent) flows through the internal flow channel of the robotic arm to the water inlet, and then is sprayed out through the first cavitation nozzle, thereby achieving the cleaning of the object surface. After the water flow is sprayed out from the first cavitation nozzle, the water flow exerts a backward recoil force on the impeller. To balance this recoil force, at the same time as the water flow is sprayed out from the first cavitation nozzle, the robotic arm can drive the impeller to rotate, thereby driving the ambient water flow to flow backward, and thus causing the ambient water flow to exert a forward thrust on the impeller to balance the recoil force, ultimately improving the self-stability of the robotic arm and the impeller.

[0021] To achieve the above objectives, the technical solution for the underwater robot provided by this invention is as follows: An underwater robot includes a robotic arm and an underwater rotating jet cleaning device connected to the end of the robotic arm. The underwater rotating jet cleaning device includes an impeller with a mounting hole at its rear end. The rotation axis of the mounting hole coincides with the rotation axis of the impeller, and the mounting hole is used to connect to the robotic arm, which has a flow channel inside, and to form a water inlet. The front end face of the impeller blades is provided with a first cavitation nozzle for spraying forward to clean the surface of an object. The impeller has a flow channel inside that connects the water inlet and the first cavitation nozzle. When in use, the blades are used to rotate under the drive of the robotic arm and drive the ambient water flow backward to balance the backward recoil force exerted by the first cavitation nozzle on the blades.

[0022] Furthermore, the rear end face of the blade is provided with a self-cleaning nozzle for spraying obliquely backward to clean the connection between the impeller and the robotic arm. The spray pressure of the self-cleaning nozzle is less than the spray pressure of the first cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet hole and the self-cleaning nozzle.

[0023] Furthermore, the self-cleaning nozzle is a second cavitation nozzle.

[0024] Furthermore, the rear end face of the blade is provided with a balancing nozzle for spraying backward to cooperate with the blade and balance the recoil force. The spray pressure of the balancing nozzle is less than the spray pressure of the first cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet hole and the balancing nozzle.

[0025] Furthermore, the impeller is a hollow impeller, and the hollow part of the hollow impeller forms a flow channel for connecting the water inlet hole and each nozzle.

[0026] Furthermore, the nozzle of the first cavitation nozzle is positioned facing directly forward.

[0027] Furthermore, the mounting hole is a threaded hole, and the direction of the female thread of the threaded hole satisfies the following: when the robotic arm drives the impeller to rotate so that the blades drive the ambient water flow backward, the male thread of the robotic arm and the female thread of the threaded hole tend to continue to tighten, so as to avoid the robotic arm from disengaging from the impeller.

[0028] Furthermore, the blades are provided with threaded holes at the corresponding positions of the first cavitation nozzles, and the first cavitation nozzles are connected to a throat tube with corresponding threads, so that the first cavitation nozzles and the blades are threadedly connected.

[0029] Furthermore, the impeller surface is coated with a waterproof coating to mitigate seawater corrosion.

[0030] The beneficial effects of the underwater robot provided by this invention are as follows: When cleaning the surface of an object, water (which may contain detergent) flows through the internal channel of the robotic arm to the water inlet, and then is sprayed out through the first cavitation nozzle, thereby cleaning the surface of the object. After the water is sprayed out from the first cavitation nozzle, the water exerts a backward recoil force on the impeller. To balance this recoil force, the robotic arm can drive the impeller to rotate at the same time as the water is sprayed out from the first cavitation nozzle, thereby driving the ambient water to flow backward, and then causing the ambient water to exert a forward thrust on the impeller to balance the recoil force, ultimately improving the self-stability of the robotic arm and the impeller. Attached Figure Description

[0031] Figure 1 A schematic diagram of the underwater rotating jet cleaning device from one perspective; Figure 2 A schematic diagram of the underwater rotating jet cleaning device from another perspective; Figure 3 for Figure 1 A schematic diagram of the hollow nozzle and throat.

[0032] Explanation of reference numerals in the attached figures: 1. Axle; 2. Inlet hole; 3. Blade; 4. Rear nozzle assembly; 5. Front nozzle assembly; 6. Cavitation nozzle; 7. Throat; 8. Sealing ring. Detailed Implementation

[0033] To address the problems in the background art, the core inventive concept of this invention is to drive the impeller to rotate actively, so as to use the force of the ambient water flow on the impeller to balance the recoil force when the cavitation nozzle is sprayed.

[0034] In this invention, the axis of the impeller is defined to extend forward and backward, and the object to be cleaned is located in front of the first cavitation nozzle, so that the surface of the object to be cleaned is cleaned by the fluid sprayed forward by the first cavitation nozzle.

[0035] The present invention will be further described in detail below with reference to the embodiments.

[0036] Example 1 of the underwater rotating jet cleaning device provided by the present invention: like Figures 1-3 As shown in the figure, as a basic specific embodiment, the underwater rotating jet cleaning device includes an impeller with a mounting hole at the rear end. The impeller includes a shaft 1 and blades 3. The rotation axis of the mounting hole coincides with the rotation axis of the impeller, and the mounting hole is used to connect with a mechanical arm with a flow channel inside to form a water inlet 2. The front end face of the blades 3 of the impeller is provided with a first cavitation nozzle for spraying forward to clean the surface of the object. The impeller is provided with a flow channel connecting the water inlet 2 and the first cavitation nozzle. When in use, the blades 3 are used to rotate under the drive of the mechanical arm and drive the ambient water flow backward to balance the backward recoil force exerted by the first cavitation nozzle on the blades 3.

[0037] Regarding the spray direction of the first cavitation nozzle, in this invention, the nozzle of the first cavitation nozzle is preferably positioned facing directly forward to reduce the distance between the fluid ejected from the nozzle and the surface to be cleaned, thereby increasing the cleaning pressure. Of course, the first cavitation nozzle can also be tilted outward to increase the cleaning area. Those skilled in the art can configure it according to actual needs, which will not be elaborated here.

[0038] Regarding the installation method of the robotic arm and impeller, in this invention, the mounting hole is preferably a threaded hole, and the direction of the female thread of the threaded hole satisfies the following: when the robotic arm drives the impeller to rotate so that the blades 3 drive the ambient water flow backward, the male thread of the robotic arm and the female thread of the threaded hole tend to continue to tighten, so as to prevent the robotic arm from disengaging from the impeller. Of course, the mounting hole can also be anti-rotationally fitted to the robotic arm by means of a flat key or spline, and connected by means of interference fit, etc. In this invention, it is only necessary to enable the robotic arm to drive the impeller to rotate and translate. Those skilled in the art, after knowing the above content, will understand that it is possible for the robotic arm to drive the impeller to rotate and translate.

[0039] In use, the robotic arm is connected to the mounting hole, and the underwater robot carries the underwater rotating jet cleaning device to the designated location for cleaning the surface of underwater structures in different areas. Then, the high-pressure water jet generated by the underwater robot enters the inlet hole 2 through the internal flow channel of the robotic arm. The internal flow channel of the robotic arm can be formed by pipes installed inside the mechanical part. The underwater robot may also include a cleaning tank containing cleaning agent, and the cleaning tank is equipped with pipes communicating with the internal flow channel of the robotic arm to clean the object surface using the cleaning agent. Next, water is ejected forward from the first cavitation nozzle, applying a backward recoil force to the impeller. Simultaneously, the robotic arm drives the impeller to rotate, causing the ambient water flow to move backward under the impeller's drive. This causes the ambient water flow to apply a forward thrust to the impeller to balance the recoil force, thereby improving the self-stability of the underwater rotating jet cleaning device and the robotic arm. During normal use, a certain distance is maintained between the first cavitation nozzle and the surface of the object to be cleaned to ensure that the ambient water flow can move backward under the drive of the impeller.

[0040] When water flows through the cavitation nozzle 6, it generates a large number of cavitation bubbles. When these cavitation bubbles collapse in a narrow area on the material surface, they can generate micro-jet impacts of up to 140–170 MPa, thus achieving the purpose of cleaning the surface deposits and dirt layers of underwater structures. The cleaning effect and efficiency are greatly improved. This method utilizes the shock wave pressure and high-speed micro-jet generated when tiny cavitation bubbles collapse to impact the surface of metal materials. It has excellent adaptability when cleaning parts with complex surface shapes, especially when there are small grooves on the surface of the parts, where the tiny cavitation bubbles in the bubble cluster can penetrate deep into them for cleaning.

[0041] In a preferred embodiment, the rear end face of the blade 3 is provided with a self-cleaning nozzle for spraying obliquely backward to clean the connection between the impeller and the robotic arm. The spray pressure of the self-cleaning nozzle is less than the spray pressure of the first cavitation nozzle. The self-cleaning nozzle is preferably a second cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet 2 and the self-cleaning nozzle.

[0042] During use, sludge and other objects adhering to the object's surface are washed away by the fluid sprayed from the first cavitation nozzle. Under the action of the ambient water flow and the water flow generated by the impeller's rotation, the sludge and other objects move backward and adhere to the connection between the robotic arm and the impeller. In a specific embodiment containing a self-cleaning nozzle, on the one hand, the self-cleaning nozzle can be used to clean the connection between the impeller and the robotic arm; on the other hand, the fluid sprayed from the self-cleaning nozzle can further transport sludge and other objects backward, ensuring that the sludge and other objects are far away from the object to be cleaned, thereby facilitating the subsequent repair of the object to be cleaned using the underwater structural defect intelligent repair robot. The underwater rotating jet cleaning device can also be installed on the robotic arm of the underwater structural defect intelligent repair robot. An electric motor provides power to the robotic arm, and a stepper motor drives the part of the robotic arm connected to the impeller to rotate, thereby driving the impeller to rotate.

[0043] In a preferred embodiment, the impeller is preferably a hollow impeller. The hollow portion of the hollow impeller forms a flow channel connecting the water inlet 2 with each nozzle (including all first cavitation nozzles and all self-cleaning nozzles), resulting in a simple and reliable structure. In this case, all nozzles have the same inlet water pressure. The nozzle's spray pressure can be reduced by increasing the nozzle's spray area, so that the spray pressure of the self-cleaning nozzle is less than that of the first cavitation nozzle. Of course, the spray pressure of the nozzles can also be adjusted in other ways when the water supply pressure is the same. Those skilled in the art can set these settings as needed, which will not be elaborated upon here.

[0044] In other specific embodiments, a central flow channel can be machined in the impeller, and a flow channel corresponding to each nozzle can be machined in each blade 3. The blade 3 is preferably a two-half structure formed by front and rear interlocking to facilitate the machining of the flow channel.

[0045] In this invention, such as Figure 3 As shown, the connection between each nozzle and the blade 3 is as follows: The blade 3 and each nozzle have corresponding threaded holes. Each nozzle is connected to a throat 7, which has corresponding threads to allow for threaded connection between the nozzle and the blade 3. To ensure watertightness, a sealing ring 8 can be installed between the throat 7 and the nozzle (e.g., the cavitation nozzle 6). The corresponding throat 7 and the first cavitation nozzle together form the front nozzle assembly 5, and the corresponding throat 7 and the second cavitation nozzle together form the rear nozzle assembly 4.

[0046] Based on the existing technology in this field that utilizes cavitation nozzles 6 to clean the surface of underwater objects (such as the Chinese invention patent with authorization announcement number CN110340062B), those skilled in the art know that it is possible to install cavitation nozzles 6 onto objects (blades 3) in various reasonable ways, which will not be elaborated here.

[0047] In this invention, to ensure watertightness, sealing rings 8 can be provided at all threaded connections. Of course, the threads at the threaded connections can also be watertight threads.

[0048] In this invention, to extend the service life of the underwater rotating jet cleaning device, the surface of the impeller can also be coated with a waterproof coating to reduce seawater corrosion.

[0049] Embodiment 2 of the underwater rotating jet cleaning device provided by the present invention: The core difference between this embodiment and Embodiment 1 is that the impeller rotation speed is different, so the magnitude of the forward thrust exerted by the ambient water flow on the impeller is different.

[0050] Based on the above-mentioned core differences, in Embodiment 1, the impeller rotates at a higher speed, and the thrust exerted by the ambient water flow on the impeller is sufficient to balance the counter-thrust force of the fluid ejected from the first cavitation nozzle on the impeller.

[0051] In Embodiment 2, the impeller rotates at a slower speed, and the thrust exerted by the ambient water flow on the impeller is insufficient to balance the counter-thrust force of the fluid ejected from the first cavitation nozzle. Therefore, in Embodiment 2, a balancing nozzle is provided on the rear end face of the blade 3 for spraying backward to cooperate with the blade 3 in balancing the counter-thrust force. The balancing nozzle can also be a cavitation nozzle 6, and the spray pressure of the balancing nozzle is lower than that of the first cavitation nozzle. The impeller has a flow channel connecting the water inlet 2 and the balancing nozzle. When the balancing nozzle is facing obliquely backward and aligned with the connection between the impeller and the robotic arm, the balancing nozzle also constitutes a self-cleaning nozzle. Of course, the balancing nozzle can also spray directly backward.

[0052] Embodiments of the underwater robot provided by this invention: The underwater robot includes a robotic arm and an underwater rotating jet cleaning device connected to the end of the robotic arm. The underwater rotating jet cleaning device is any one of the embodiments of the underwater rotating jet cleaning device of the present invention, and will not be described in detail here.

[0053] In use, onshore personnel only need to operate the underwater robot and control the start and stop of the underwater rotating jet cleaning device from the control room. This facilitates the cleaning of underwater structural surfaces, providing a good working environment and conditions for subsequent intelligent defect inspection and repair. The operation is easy for onshore personnel to learn. Using an underwater structural defect intelligent inspection robot (i.e., an underwater robot) to drive the underwater rotating jet cleaning device enables faster and cleaner cleaning of underwater structural surfaces, improving cleaning efficiency and the accuracy of subsequent defect inspection and repair.

[0054] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features, or organically combine different embodiments to create the embodiments shown in the accompanying drawings. Of course, those skilled in the art can also create other embodiments not shown in the accompanying drawings. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An underwater rotating jet cleaning device, characterized in that, The device includes an impeller with a mounting hole at the rear end, the rotation axis of which coincides with the rotation axis of the impeller, and the mounting hole is used to connect with a robotic arm with an internal flow channel to form a water inlet; the front end face of the impeller blades is provided with a first cavitation nozzle for spraying forward to clean the surface of an object, and the impeller is provided with a flow channel connecting the water inlet and the first cavitation nozzle; when in use, the blades are used to rotate under the drive of the robotic arm and drive the ambient water flow backward to balance the backward recoil force exerted by the first cavitation nozzle on the blades.

2. The underwater rotating jet cleaning device as described in claim 1, characterized in that, The rear end face of the blade is provided with a self-cleaning nozzle for spraying obliquely backward to clean the connection between the impeller and the robotic arm. The spray pressure of the self-cleaning nozzle is less than the spray pressure of the first cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet hole and the self-cleaning nozzle.

3. The underwater rotating jet cleaning device as described in claim 2, characterized in that, The self-cleaning nozzle is a second cavitation nozzle.

4. The underwater rotating jet cleaning device as described in claim 1, characterized in that, The rear end face of the blade is provided with a balancing nozzle for spraying backward to cooperate with the blade and balance the recoil force. The spray pressure of the balancing nozzle is less than the spray pressure of the first cavitation nozzle. The impeller is provided with a flow channel connecting the water inlet hole and the balancing nozzle.

5. The underwater rotating jet cleaning device as described in any one of claims 1 to 4, characterized in that, The impeller is a hollow impeller, and the hollow part of the hollow impeller forms a flow channel for connecting the water inlet hole and each nozzle.

6. The underwater rotating jet cleaning device as described in any one of claims 1 to 4, characterized in that, The nozzle of the first cavitation nozzle is positioned facing directly forward.

7. The underwater rotating jet cleaning device as described in any one of claims 1 to 4, characterized in that, The mounting hole is a threaded hole, and the direction of the female thread of the threaded hole satisfies the following: when the robotic arm drives the impeller to rotate so that the blades drive the ambient water flow backward, the male thread of the robotic arm and the female thread of the threaded hole tend to continue to tighten, so as to avoid the robotic arm from disengaging from the impeller.

8. The underwater rotating jet cleaning device as described in any one of claims 1 to 4, characterized in that, The blades are provided with threaded holes at the corresponding positions of the first cavitation nozzles. The first cavitation nozzles are connected to a throat tube with corresponding threads to enable the first cavitation nozzles to be threadedly connected to the blades.

9. The underwater rotating jet cleaning device as described in any one of claims 1 to 4, characterized in that, The impeller surface is coated with a waterproof coating to mitigate seawater corrosion.

10. An underwater robot, comprising a robotic arm and an underwater rotating jet cleaning device connected to the end of the robotic arm, characterized in that, The underwater rotating jet cleaning device is any one of claims 1 to 9.

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