Underwater hydraulic manipulator with pressure compensation

Abstract

An underwater hydraulic robotic arm with pressure compensation includes a first robotic arm, an elbow joint assembly, and a second robotic arm connected in sequence. Both the first and second robotic arms have enclosed internal cavity structures. The elbow joint assembly has an internal oil passage that connects to and is filled with hydraulic oil through the internal cavities of the first and second robotic arms. The arm also includes a hydraulic system pressure compensator and a cavity pressure compensator. The advantage of this invention is that, through the combination of the cavity design of the first and second robotic arms and the hydraulic system pressure compensator and cavity pressure compensator, the outer walls of the first and second robotic arms are not deformed by seawater pressure during deep-sea exploration. The hydraulic system compensator not only prevents backflow of hydraulic oil in the hydraulic pipes but also avoids the impact of external pressure on the accuracy of the hydraulic actuators.

Description

Technical Field

[0001] This disclosure relates to the field of hydraulic systems, and in particular to a system for designing internal pressure compensation for the outer wall of a robotic arm in the context of underwater cavity design. Background Technology

[0002] In order to cope with the pressure of seawater, the support structure of most commercially available deep-sea underwater robotic arms is completely exposed and submerged in seawater. This makes it impossible to connect electronic and hydraulic components that cannot be in contact with seawater to the robotic arm. However, some robotic arms use a closed structure design, which makes the internal cavity of the robotic arm linkage hollow. However, due to the pressure of seawater depth, the diving depth of such robotic arms is limited to a certain extent.

[0003] Many underwater robotic arms use hydraulic components for joint actuation that require enclosed design. These enclosed joints encounter significant underwater pressure in deep water, often requiring connections via compensator piping. However, these joints are frequently not interconnected, necessitating piping from the hydraulic system to the required joints. Exposing this piping to the robotic arm's outer surface leads to leaks and pipe entanglement due to the seabed environment. Therefore, the piping needs to be placed within the sealed internal cavity of the robotic arm. However, in deep-sea operations, the pressure of the seawater deforms the walls of the internal cavity of a hollow robotic arm. Summary of the Invention

[0004] In view of the above, it is necessary to disclose an underwater hydraulic manipulator with pressure compensation, which aims to balance the pressure of the internal cavity of the manipulator with that of seawater.

[0005] An underwater hydraulic robotic arm with pressure compensation includes a first robotic arm, an elbow joint assembly, and a second robotic arm connected in sequence. The first robotic arm and the second robotic arm are both provided with a closed internal cavity structure. The elbow joint assembly is provided with an oil passage, which is connected to and filled with hydraulic oil through the internal cavity structures of the first robotic arm and the second robotic arm.

[0006] It also includes a hydraulic system pressure compensator and a cavity pressure compensator. A hydraulic actuator is installed inside the first robotic arm. The hydraulic system pressure compensator is connected to the hydraulic system, and the hydraulic system is connected to the hydraulic actuator through a hydraulic pipe. The cavity pressure compensator is connected to the hydraulic oil.

[0007] Furthermore, one end of the hydraulic system pressure compensator is in contact with seawater, and the other end of the hydraulic system pressure compensator is connected to the hydraulic system;

[0008] One end of the cavity pressure compensator is connected to seawater, and the other end of the cavity pressure compensator is connected to the hydraulic oil in the oil passage and / or the first robotic arm and / or the second robotic arm.

[0009] Furthermore, the elbow joint assembly includes an assembly head and side frames located on both sides of the assembly head. Connecting ears are provided on both sides of the assembly head, and the side frames are rotatably connected to the connecting ears. A connecting rod is transversely disposed through the assembly head, and the connecting rod is disposed through the connecting ears on both sides. The oil passage includes a flow gap and an oil channel, with the flow gap formed between the outer surface of the connecting rod and the inner wall of the connecting ear. A cover plate is provided outside the side frames, and the oil channel is formed inside the cover plate. One end of the flow gap communicates with an oil inlet, and the other end of the flow gap communicates with one end of the oil channel, and the other end of the oil channel communicates with the internal cavity structure of the second robotic arm. The oil inlet communicates with the internal cavity structure of the first robotic arm.

[0010] Furthermore, a bearing is provided between the connecting lug and the side frame, the inner ring of the bearing is connected to the connecting lug, and the outer ring of the bearing is connected to the side frame; the side frame is provided with a through hole, one side of the through hole is connected to the oil passage groove, and the other side of the through hole is connected to the internal cavity structure of the second robotic arm.

[0011] Furthermore, a first sealing ring is provided between the bearing and the assembly head; a step is provided on the side frame, an end cap is embedded in the step, and a second sealing ring is provided between the end cap and the step.

[0012] Furthermore, the system includes an installation platform, on which the hydraulic system pressure compensator, pressure system, and cavity pressure compensator are all mounted. The lower end of the first robotic arm is connected to the installation platform, and the end of the second robotic arm is connected to a hand joint assembly, which is connected to the robotic hand.

[0013] Furthermore, the first robotic arm is provided with a hydraulic system pressure compensator interface and a cavity pressure compensator interface near the mounting platform; the hydraulic system pressure compensator is connected to the hydraulic system pressure compensator interface, and the cavity pressure compensator is connected to the cavity pressure compensator interface.

[0014] Furthermore, the installation platform is provided with a base, and the lower end of the first robotic arm is hinged to the base; one end of the hydraulic actuator is hinged to the first robotic arm, and the other end of the hydraulic actuator is hinged to the base.

[0015] Furthermore, the end of the connecting rod is provided with a protruding post, and the center of the end cap is provided with a socket, which corresponds to and matches the protruding post.

[0016] Furthermore, the bearing is a tapered roller bearing, the first sealing ring is a lip seal, and the second sealing ring is an O-ring.

[0017] This invention, through the combination of the cavity design of the first and second robotic arms with the hydraulic system pressure compensator and the cavity pressure compensator, ensures that the outer walls of the cavities of the first and second robotic arms are not deformed by seawater pressure during deep-sea exploration. The hydraulic system compensator not only prevents the backflow of hydraulic oil in the hydraulic pipes but also avoids the impact of external pressure on the accuracy of the actuators. The hydraulic system pressure compensator interface and the cavity pressure compensator interface are designed at the tail of the first robotic arm, allowing the oil pipes and compensation system oil circuits to be designed on the mounting platform, avoiding pipe bending and entanglement problems caused by joint rotation. Furthermore, the elbow joint assembly uses a connected design, enabling the oil circuit to provide pressure compensation for the entire mechanism and facilitating the installation of electronic sensing elements, cameras, and control elements on the robotic arm.

[0018] This design differs from traditional exposed underwater robotic arms that are submerged in water. Due to its hollow design and the fact that the interior is filled with insulating hydraulic oil, the electrical components are waterproofed, enabling more functions. Control, sensing, and vision have all been improved, making the entire robotic arm more intelligent. Attached Figure Description

[0019] To more clearly illustrate the specific implementation methods, the accompanying drawings used in the description of the implementation methods will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is an overall diagram of the present invention;

[0021] Figure 2 This is a schematic diagram of the elbow joint assembly and the second robotic arm of the present invention in a separated state.

[0022] Figure 3 This is a schematic diagram of the internal structure of the first robotic arm;

[0023] Figure 4 It is an exploded view of the assembly head and the components in the side frame;

[0024] Figure 5 It is a 3D view of the cover plate;

[0025] Figure 6 It is a cross-sectional view showing the first robotic arm, the elbow joint assembly, and the second robotic arm in a connected state.

[0026] Explanation of main component symbols

[0027]

[0028]

[0029] The following detailed embodiments will further illustrate this disclosure in conjunction with the above-described drawings. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the disclosure will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of this disclosure; the described embodiments are merely a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0032] In various embodiments, for ease of description and not limitation of this disclosure, the term "connection" used in the patent application specification and claims is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0033] like Figures 1 to 6As shown, an underwater hydraulic robotic arm with pressure compensation includes a first robotic arm 1, an elbow joint assembly 2, and a second robotic arm 3 connected in sequence. The elbow joint assembly 2 is hinged to the first robotic arm 1, and the second robotic arm 3 is connected to the elbow joint assembly 2. Both the first robotic arm 1 and the second robotic arm 3 are provided with a closed internal cavity structure. The elbow joint assembly 2 has an oil passage inside, which is connected to the internal cavity structure of the first robotic arm 1 and the second robotic arm 3 and filled with hydraulic oil. The hydraulic oil is an insulating oil, meaning that the components inside the first robotic arm 1, the second robotic arm 3, and the elbow joint assembly 2 are immersed in insulating oil, which also achieves a waterproof effect.

[0034] It also includes a hydraulic system pressure compensator 4 and a cavity pressure compensator 5. A hydraulic actuator 6 is installed inside the first robotic arm 1. The hydraulic system pressure compensator 4 is connected to the hydraulic system 7. Specifically, one end of the hydraulic system pressure compensator 4 is in contact with seawater, and the other end of the hydraulic system pressure compensator 4 is connected to the hydraulic system 7. The function of the hydraulic system pressure compensator 4 in contact with seawater is to be sensitive to the surrounding seawater environmental pressure and transmit the seawater environmental pressure to the hydraulic system 7 to compensate for the pressure of the hydraulic system 7, so as to eliminate or reduce the influence of seawater environmental pressure on the hydraulic system. The hydraulic system then transmits the compensated hydraulic oil to the hydraulic actuator 6, avoiding phenomena such as hydraulic oil backflow and hydraulic pipe interface rupture, and ensuring high safety.

[0035] The cavity pressure compensator 5 is connected to hydraulic oil. Specifically, one end of the cavity pressure compensator 5 is connected to seawater, and the other end of the cavity pressure compensator 5 is connected to the hydraulic oil in the oil passage and / or the first robotic arm 1 and / or the second robotic arm 3. Preferably, the other end of the cavity pressure compensator 5 is connected to the first robotic arm 1 for easy wiring. Similarly, the function of one end of the cavity pressure compensator 5 in contact with seawater is to sense the surrounding seawater environmental pressure and transmit the seawater environmental pressure to the hydraulic oil in the first robotic arm 1 to compensate for the pressure of the hydraulic oil in the first robotic arm 1. This makes the internal hydraulic oil pressure in the oil passage, the first robotic arm 1, and the second robotic arm 3 the same as or close to the external pressure. This makes the pressure of the seawater on the outer wall of the first robotic arm 1 and the second robotic arm 3 consistent with the pressure of the hydraulic oil on the inner wall of the first robotic arm 1 and the second robotic arm 3, thus achieving pressure balance and preventing the mechanical structure walls from being squeezed inward due to the seawater pressure.

[0036] The elbow joint assembly 2 includes an assembly head 201 and side frames 202 located on both sides of the assembly head 201. Connecting ears 2011 are provided on both sides of the assembly head 201, and the side frames 202 are rotatably connected to the connecting ears 2011. A bearing 8 is provided between the connecting ears 2011 and the side frames 202. The inner ring of the bearing 8 is connected to the connecting ears 2011, and the outer ring of the bearing 8 is connected to the side frames 202. This allows the side frames 202 to be smoothly rotatably connected to the connecting ears 2011. The bearing 8 is a tapered roller bearing. Tapered roller bearings have the advantages of being suitable for heavy-duty mechanisms or mechanisms with impact loads, and can withstand radial and axial loads simultaneously.

[0037] A connecting rod 203 is transversely arranged through the assembly head 201, and the connecting rod 203 is arranged through the connecting ears 2011 on both sides; the oil passage includes a flow gap 204 and an oil passage groove 1801, and the flow gap 204 is formed between the outer surface of the connecting rod 203 and the inner wall of the connecting ear 2011; a cover plate 18 is provided on the outside of the side frame 202, and the oil passage groove 1801 is opened on the inner side of the cover plate 18; the cover plate 18 is installed and fixed on the outer side of the side frame 202, one end of the flow gap 204 is connected to the oil inlet 205, and the other end of the flow gap 204 is connected to one end of the oil passage groove 1801, from Figure 5 It can be seen that the side frame 202 has a reserved opening corresponding to the oil passage groove 1801, which allows the flow gap 204 and the oil passage groove 1801 to remain unobstructed after the cover plate 18 is assembled to the side frame 202; the oil inlet 205 is located inside the assembly head 201, and the other end of the oil passage groove 1801 is connected to the internal cavity structure of the second robotic arm 3; the oil inlet 205 is connected to the internal cavity structure of the first robotic arm 1.

[0038] The side frame 202 is provided with a through hole 2021. One side of the through hole 2021 is connected to the oil passage groove 1801, and the other side of the through hole 2021 is connected to the internal cavity structure of the second robotic arm 3. Therefore, the first robotic arm 1 and the second robotic arm 3 are connected by oil passage through the oil inlet 205, the flow gap 204, the oil passage groove 1801 and the through hole 2021 in sequence.

[0039] A first sealing ring 9 is provided between the bearing 8 and the assembly head 201. The first sealing ring 9 is a lip seal. The side frame 202 is provided with a step position 2022. An end cover 10 is embedded in the step position 2022. A second sealing ring 11 is provided between the end cover 10 and the step position 2022. The second sealing ring 11 is an O-ring seal. Both the first sealing ring 9 and the second sealing ring 11 are used to seal the inside of the first robotic arm 1 and the second robotic arm 3 when the hydraulic oil is full.

[0040] The installation platform 12, hydraulic system pressure compensator 4, pressure system and cavity pressure compensator 5 are all installed on the installation platform 12. The lower end of the first robotic arm 1 is connected to the installation platform 12, the end of the second robotic arm 3 is connected to the hand joint assembly 13, and the hand joint assembly 13 is connected to the robotic hand 14.

[0041] The first robotic arm 1 is equipped with a hydraulic system pressure compensator interface 15 and a cavity pressure compensator interface 16 near the mounting platform 12. The hydraulic system pressure compensator 4 is connected to the hydraulic system pressure compensator interface 15, and the cavity pressure compensator 5 is connected to the cavity pressure compensator interface 16. The mounting platform 12 is located externally, and the hydraulic system pressure compensator 4, the pressure system, and the cavity pressure compensator 5 are all mounted on the mounting platform 12 to avoid immersion. The hydraulic system pressure compensator interface 15 and the cavity pressure compensator interface 16 are located at a low position on the first robotic arm 1 for easy wiring.

[0042] The mounting platform 12 is provided with a base 17, and the lower end of the first robotic arm 1 is hinged to the base 17. One end of the hydraulic actuator 6 is hinged to the first robotic arm 1, and the other end of the hydraulic actuator 6 is hinged to the base 17. The hydraulic actuator 6 is a hydraulic cylinder, so the extension and retraction of the hydraulic actuator 6 can drive the first robotic arm 1 to rotate relative to the base 17.

[0043] The end of the connecting rod 203 is provided with a protruding post 2031, and the center of the end cap 10 is provided with a socket 1001. The socket 1001 corresponds to and matches the post, so that the end cap 10 can be tightly assembled on the connecting rod 203.

[0044] In the several specific embodiments provided in this disclosure, it will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within this disclosure. Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Terms such as "first," "second," etc., are used to denote names and do not indicate any particular order.

[0045] The above embodiments are only used to illustrate the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this disclosure should not depart from the spirit and scope of the technical solutions of this disclosure.

Claims

1. An underwater hydraulic robot arm with pressure compensation, characterized in that, The device includes a first robotic arm, an elbow joint assembly, and a second robotic arm connected in sequence. Both the first and second robotic arms have enclosed internal cavity structures. The elbow joint assembly has an internal oil passage that connects to and is filled with hydraulic oil through the internal cavity structures of the first and second robotic arms. It also includes a hydraulic system pressure compensator and a cavity pressure compensator. A hydraulic actuator is installed inside the first robotic arm. The hydraulic system pressure compensator is connected to the hydraulic system, and the hydraulic system is connected to the hydraulic actuator through a hydraulic pipe. The cavity pressure compensator is connected to the hydraulic oil. One end of the hydraulic system pressure compensator is in contact with seawater, and the other end of the hydraulic system pressure compensator is connected to the hydraulic system; one end of the cavity pressure compensator is connected to seawater, and the other end of the cavity pressure compensator is connected to the hydraulic oil in the oil passage and / or the first robotic arm and / or the second robotic arm; The elbow joint assembly includes an assembly head and side frames located on both sides of the assembly head. Connecting ears are provided on both sides of the assembly head, and the side frames are rotatably connected to the connecting ears. A connecting rod is transversely disposed through the assembly head, and the connecting rod is disposed through the connecting ears on both sides. The oil passage includes a flow gap and an oil channel, with the flow gap formed between the outer surface of the connecting rod and the inner wall of the connecting ear. A cover plate is provided outside the side frames, and the oil channel is formed inside the cover plate. One end of the flow gap is connected to an oil inlet, and the other end of the flow gap is connected to one end of the oil channel, which is connected to the internal cavity structure of the second robotic arm. The oil inlet is connected to the internal cavity structure of the first robotic arm.

2. The underwater hydraulic manipulator with pressure compensation according to claim 1, characterized in that, The system includes a bearing disposed between the connecting lug and the side frame, with the inner ring of the bearing connected to the connecting lug and the outer ring of the bearing connected to the side frame; the side frame is provided with a through hole, one side of which communicates with the oil passage groove and the other side of which communicates with the internal cavity structure of the second robotic arm.

3. The underwater hydraulic manipulator arm with pressure compensation according to claim 2, characterized in that, A first sealing ring is provided between the bearing and the assembly head; a step is provided on the side frame, an end cap is embedded in the step, and a second sealing ring is provided between the end cap and the step.

4. The underwater hydraulic manipulator arm with pressure compensation according to claim 3, characterized in that, The system includes an installation platform, on which the hydraulic system pressure compensator, pressure system, and cavity pressure compensator are all mounted. The lower end of the first robotic arm is connected to the installation platform, and the end of the second robotic arm is connected to a hand joint assembly, which is connected to the robotic hand.

5. The underwater hydraulic manipulator arm with pressure compensation according to claim 4, characterized in that, The first robotic arm is provided with a hydraulic system pressure compensator interface and a cavity pressure compensator interface near the mounting platform; the hydraulic system pressure compensator is connected to the hydraulic system pressure compensator interface, and the cavity pressure compensator is connected to the cavity pressure compensator interface.

6. The hydraulic underwater robotic arm with pressure compensation according to claim 5, characterized in that, The installation platform is provided with a base, and the lower end of the first robotic arm is hinged to the base; one end of the hydraulic actuator is hinged to the first robotic arm, and the other end of the hydraulic actuator is hinged to the base.

7. The hydraulic underwater robotic arm with pressure compensation according to claim 4, characterized in that, The end of the connecting rod is provided with a protruding post, and the center of the end cap is provided with a socket, which corresponds to and matches the protruding post.

8. The underwater hydraulic manipulator arm with pressure compensation according to claim 5, characterized in that, The bearing is a tapered roller bearing, the first sealing ring is a lip seal, and the second sealing ring is an O-ring.

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