Snake bone joint, flexible joint assembly and surgical operation arm

Abstract

The utility model discloses a snake bone joint, a flexible joint assembly and a surgical operation arm, relates to the technical field of medical instruments, and aims to relieve the problem that two snake bones slide in an uncertain dislocation mode when the snake bone joint is bent. The snake bone joint comprises a first snake bone and a second snake bone, the first snake bone and the second snake bone can rotate based on respective pivots, the two pivots are parallel, and the distance between the two pivots is constant; the first snake bone comprises a restraint roller, the second snake bone comprises a restraint hole site, and the restraint roller is movably arranged in the restraint hole site; the restraining hole site comprises a first restraining face and a second restraining face which are oppositely arranged, and the restraining roller arranged in the restraining hole site is clamped between the first restraining face and the second restraining face. Therefore, the snake bone joint has the advantage that the bending precision and the load deformation resistance of the snake bone joint are improved.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and more specifically, to a snake-bone joint, a flexible joint assembly, and a surgical arm. Background Technology

[0002] With advancements in technology, laparoscopic surgery allows surgeons to perform procedures through smaller incisions, resulting in shorter hospital stays, safer surgeries, and faster recovery for patients. During laparoscopic surgery, surgeons frequently manipulate the surgical arm to yaw or rotate it to perform surgical operations at designated locations within the patient's body. The surgical arm typically uses a serpentine joint to achieve yaw movements.

[0003] In related technologies, although the snake joint can be bent by pulling back and releasing the drive cables threaded between the snake bones, the relative rotational state between the snake bones is uncertain. This makes it difficult to ensure consistent cable retraction or maintain a balanced lever arm between the drive cables on both sides of the snake joint during bending. The drive cables are prone to deformation or even damage, affecting the control precision and lifespan of the snake joint and the surgical arm. Furthermore, the uncertain relative rotational state between the snake bones prevents the snake joint from having a unique shape at a specified bending angle. When any snake bone in the joint is subjected to external force, the joint is highly susceptible to deformation, introducing uncertainties and risks to the surgical procedure and reducing the reliability of the snake joint and surgical arm when used in surgical operations. Utility Model Content

[0004] The purpose of this application is to provide a snake joint, a flexible joint component, and a surgical arm, which can alleviate the problem of uncertain misalignment and slippage between the two snake bones when the snake joint is bent, and has the advantages of improving the bending accuracy and load deformation resistance of the snake joint.

[0005] The embodiments of this application are implemented as follows:

[0006] In a first aspect, embodiments of this application provide a snake-bone joint, including a first snake bone and a second snake bone, both of which are capable of rotating based on their respective pivots, the two pivots being parallel and having a constant distance between them; the first snake bone includes a constraint roller, and the second snake bone includes a constraint hole, the constraint roller being movably disposed within the constraint hole; the constraint hole includes a first constraint surface and a second constraint surface disposed opposite to each other, the constraint roller disposed within the constraint hole being sandwiched between the first constraint surface and the second constraint surface.

[0007] In the above technical solution, with the two snake bones' pivots parallel and the distance between them constant, the constraint roller is movably disposed within the constraint hole to support the design of the snake bone joint to achieve bending action, making the assembly of the snake bone joint simpler and more efficient. Furthermore, the constraint roller's placement between the first and second constraint surfaces ensures that regardless of the degree of bending of the snake bone joint or the location of the constraint roller within the constraint hole, the contact between the constraint hole and the constraint roller provides bidirectional limiting to the two snake bones, restricting uncertain lateral sliding between them, improving the bending accuracy and load-bearing deformation resistance of the snake bone joint, and achieving a symmetrical motion configuration during the bending process of the snake bone joint. Moreover, the constraint roller's placement between the two constraint surfaces makes the force distribution on the two snake bones more uniform, reducing local stress concentration, further reducing snake bone wear, and making the snake bone rotation smoother and more fluid.

[0008] In some embodiments, the pivot of the first snake bone is a first pivot, and the first snake bone includes a first end face and a first connecting portion. The first end face is parallel to or coincides with the first pivot. The constraint roller is connected to the first end face through the first connecting portion. The central axis of the constraint roller is parallel to the first pivot, and both the first pivot and the central axis of the constraint roller coincide with the same plane, which is perpendicular to the first end face. In the above technical solution, the design that the central axis of the constraint roller is parallel to the first pivot and that the common plane is perpendicular to the first end face gives the snake bone joint better symmetry and consistency in a straight state, which helps the snake bone to be subjected to uniform and stable force and reduce wear. In addition, this vertical alignment makes the manufacturing, assembly and motion control of the snake bone joint simpler and more intuitive, which is conducive to improving the motion accuracy of the snake bone joint and the motion consistency of the components in the snake bone joint, thereby improving the overall performance of the snake bone joint.

[0009] In some embodiments, in the snake-bone joint, the distance between the two pivots is the center distance, and the vertical distance between the central axis of the constraint roller and the first pivot is less than the center distance. In the above technical solution, the setting that the vertical distance between the constraint roller and the first pivot is less than the center distance makes the overall structure of the snake-bone joint simpler and more compact, reducing the difficulty of processing and assembling the snake-bone joint.

[0010] In some embodiments, the constraint roller is a cylindrical roller, the first constraint surface extends according to a first curve, and the second constraint surface extends according to a second curve. The first and second curves are the two side contour lines of the movement trajectory formed on the second serpentine when the target circle follows the rotation of the first serpentine. The center of the target circle coincides with the central axis of the cylindrical roller, and the radius of the target circle is equal to the radius of the cylindrical roller. In the above technical solution, the first and second curves are obtained based on the movement trajectory of the target circle, which allows the constraint roller to move along a smoother path within the constraint hole, improving the smoothness and stability of the serpentine bending. The coincidence of the center of the target circle with the central axis of the cylindrical roller and the equality of the radius of the target circle with the radius of the cylindrical roller improve the positioning accuracy of the constraint roller within the constraint hole, thereby improving the bending accuracy of the serpentine joint. The constraint roller is a cylindrical roller, and the two constraint surfaces are generated based on the movement trajectory of the cylindrical roller, so that the constraint roller and the two constraint surfaces are in tangential contact with circular arcs, which improves the load capacity of the serpentine joint, reduces local stress concentration, and extends the service life of the serpentine joint.

[0011] In some embodiments, the constraint hole further includes a first limiting end face and a second limiting end face. The first limiting end face is disposed at one end of the first constraint surface and the second constraint surface, and the second limiting end face is disposed at the other end of the first constraint surface and the second constraint surface. Both the first limiting end face and the second limiting end face are used to limit the maximum rotation angle of the first snake bone relative to the second snake bone. In the above technical solution, the setting of the limiting end face can limit the maximum rotation angle of the snake bone and the maximum bending angle of the snake bone joint, reducing the probability of snake bone joint damage caused by excessive rotation, and enabling the snake bone joint to achieve bending movement more smoothly and accurately within the preset bending angle range, thereby improving the reliability and durability of the snake bone joint.

[0012] In some embodiments, both the first and second snake bones have multiple sets of lanyard holes, symmetrically arranged on both sides of the pivot. These lanyard holes are used to accommodate drive cables or constraint cables. In the above technical solution, the symmetrical arrangement of multiple sets of lanyard holes makes the overall structure of the snake bone joint more compact and reduces the pulling and interference on the movement of the constraint or drive cables when the snake bones rotate relative to each other. Furthermore, the symmetrical arrangement of multiple sets of lanyard holes ensures that the connection positions of the drive cables on both sides of the snake bone joint to each snake bone are symmetrical and equidistant from the pivot. When the snake bone joint can achieve a symmetrical motion configuration, the drive cables on both sides of the snake bone joint can achieve consistent extension and retraction with balanced lever arms, thereby extending the service life of the drive cables.

[0013] In some embodiments, the snake-bone joint further includes two opposing, rollingly contacting arc-shaped top surfaces, which are respectively disposed on the adjacent and opposing first end faces of the first and second snake bones; the distance between the two pivots is the center distance, the radius of each arc-shaped top surface is half of the center distance, and the axis of the arc-shaped top surface coincides with the pivot. In the above technical solution, the arrangement of the arc-shaped top surfaces can reduce snake bone wear, and the rolling contact and the fact that the radii of the arc-shaped top surfaces are all half of the center distance make it difficult for the pivots of the two snake bones to approach each other when they rotate relative to each other, thereby improving the smoothness of the snake-bone joint bending and the stability of the structure, improving the load-bearing capacity of the snake-bone joint, and reducing the processing and assembly difficulty of the snake-bone joint.

[0014] In some embodiments, the snake-bone joint further includes at least one connecting pin, which comprises two connecting pin shafts and a connecting rod, the connecting rod being vertically connected between the two parallel connecting pin shafts; in the snake-bone joint, the connecting pin shaft is rotatably connected to the first or second snake bone and coincides with the pivot. In the above technical solution, the snake-bone joint fixes the center distance between the two snake bone pivots through the connecting pin, making it difficult for the two pivots to approach or move away from each other when the two snake bones rotate relative to each other, thereby improving the bending accuracy and bending reliability of the snake-bone joint.

[0015] Secondly, embodiments of this application provide a flexible joint assembly, which includes at least two serpentine joints as described in any embodiment of the first aspect of this application, at least two drive cables, and at least two constraint cables. The at least two serpentine joints extend in the same pivot direction; each drive cable and each constraint cable extends and passes through each serpentine joint; the connection positions of the constraint cables on the serpentine joints are symmetrical based on the pivot; between the two serpentine joints with the same pivot direction and the closest positions, the connection position of each constraint cable to the nearest serpentine joint is a first connection position, and the connection position of each constraint cable to the farthest serpentine joint is a second connection position. The first connection position is shifted by 180° relative to the second connection position based on the central axis of the flexible joint assembly. In the above technical solution, the 180° shift of the same constraint cable based on the central axis of the flexible joint assembly ensures that the two serpentine joints with the closest positions and the same bendable direction have a fixed bending angle when the flexible joint assembly deflects as a whole. That is, the flexible joint assembly has a unique shape at a specified deflection angle. Embodiments of this application improve the load-bearing deformation resistance of the flexible joint assembly.

[0016] Thirdly, embodiments of this application provide a surgical operating arm, which includes at least one flexible joint component provided in any embodiment of the second aspect of this application. In the above technical solutions, the surgical operating arm has the same technical effects as the aforementioned flexible joint component.

[0017] The advantages of this application compared to the prior art are:

[0018] This application addresses the problem of uncertain misalignment and slippage between the serpentine bones during bending of a serpentine joint. In the embodiments of this application, with two pivots parallel and at a constant distance, a constraint roller is movably disposed within a constraint hole to support the bending of the serpentine joint, making the assembly of the serpentine joint simpler and more efficient. The constraint roller, sandwiched between the first and second constraint surfaces, ensures that regardless of the degree of bending, the contact between the constraint hole and the constraint roller provides bidirectional limiting to the two serpentine bones, thereby restricting uncertain lateral slippage between them. This improves the bending accuracy and load-bearing deformation resistance of the serpentine joint and achieves a symmetrical motion configuration during bending. Furthermore, the serpentine joint can also achieve consistent cable extension and retraction and lever arm balance through a symmetrical arrangement of the drive cables based on the pivots.

[0019] Furthermore, the arrangement of the constraint rollers perpendicularly aligned with the pivot and the first end face makes the manufacturing, assembly, and motion control of the serpentine joint simpler and more intuitive. The two constraint surfaces, extended based on the motion trajectory of the constraint rollers, improve the bending accuracy, bending smoothness, and motion stability of the serpentine joint, thereby enhancing its load-bearing capacity and durability. The setting of the limiting end face reduces the probability of damage caused by excessive bending of the serpentine joint, improving its reliability and durability. Between two serpentine joints with the same pivot extension direction and the closest positions, the constraint cables are connected by a 180-degree shift, ensuring that the flexible joint assembly typically has a unique shape at a specified deflection angle, thus improving the flexible joint assembly's resistance to load deformation. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the surgical robot shown in some embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the overall structure of the surgical arm shown in some embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the structure of a second flexible joint assembly shown in some embodiments of this application;

[0024] Figure 4This is a front view schematic diagram of a second flexible joint assembly shown in some embodiments of this application;

[0025] Figure 5 This is a schematic diagram of the overall structure of the snake-bone joint shown in some embodiments of this application;

[0026] Figure 6 This is a front view schematic diagram of a snake-bone joint shown in some embodiments of this application;

[0027] Figure 7 This is a schematic diagram illustrating the geometric principle of a snake-bone joint in some embodiments of this application;

[0028] Figure 8 This is a schematic diagram of the overall structure of the first snake bone shown in some embodiments of this application.

[0029] Icons: 1-Surgical robot; 2-Surgical arm; 21-Tool head; 22-Instrument box; 23-Straight instrument tube; 3-Flexible joint component; 30-Flexible joint assembly; 31-First flexible joint assembly; 32-Second flexible joint assembly; 33-Drive cable; 34-Constraint cable; 340-Connection position; 341-First connection position; 342-Second connection position; 4-Hex joint; 401-First helical joint; 402-Second helical joint; 403-Third helical joint; 404-Fourth helical joint; 41-Support Structure; 411-Connecting pin; 4111-Connecting pin shaft; 4112-Connecting rod; 5-Snake bone; 50-First end face; 501-First snake bone; 502-Second snake bone; 51-Pivot; 511-First pivot; 512-Second pivot; 52-Constraint roller; 520-First connecting part; 53-Constraint hole; 530-Target circle; 5301-First curve; 5302-Second curve; 531-First constraint surface; 532-Second constraint surface; 533-First limiting end face; 534-Second limiting end face; 54-Rope hole. Detailed Implementation

[0030] The terms “first,” “second,” “third,” etc., are used only for distinguishing descriptions and do not indicate a sequence number, nor should they be interpreted as indicating or implying relative importance.

[0031] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of this application, it should be noted that the terms "inner", "outer", "left", "right", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] In the description of this application, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components.

[0034] The technical solution of this application will now be described in detail with reference to the accompanying drawings.

[0035] Surgical robots, as an important research technology in the field of medical devices, are widely used in surgical procedures, assisting surgeons in performing various types of minimally invasive and non-invasive surgeries. Among them, surgical robots with flexible joint components or snake-bone joints are specially designed robots that can operate in confined spaces and perform complex bending or rotational movements inside the human body. Compared with traditional rigid surgical instruments, this type of surgical robot has many advantages. Using this type of surgical robot to perform surgery can not only improve the precision of surgical operations, but also reduce damage to surrounding tissues at the surgical site, shorten recovery time, and reduce the risk of complications.

[0036] In related technologies, although the snake joint can bend at a specified angle by pulling back and releasing the drive cables threaded between the snake bones, the relative rotation state between the snake bones is uncertain. Consequently, the snake joint does not have a unique shape at a specified bending angle. Once subjected to external force interference, the snake joint is prone to misalignment and deformation, affecting the reliability and safety of the surgical operation.

[0037] Based on the above considerations, this application provides a snake-bone joint. When the pivots of the two snake bones are parallel and the distance between them is constant, the constraint roller is movably disposed in the constraint hole to support the bending action of the snake-bone joint. On this basis, the constraint roller is sandwiched between the first constraint surface and the second constraint surface. No matter how much the snake-bone joint is bent, the contact and cooperation between the constraint hole and the constraint roller can provide bidirectional limiting effect to the snake bones, so as to limit the uncertain lateral sliding between the two snake bones, realize the symmetrical motion configuration during the bending process of the snake-bone joint, and improve the bending accuracy and load deformation resistance of the snake-bone joint.

[0038] Please see Figure 1 , Figure 1 This is a schematic diagram of the overall structure of the surgical robot 1 shown in some embodiments of this application. For example... Figure 1 As shown, the surgical robot 1 may include at least one surgical arm 2. The surgical arm 2 is used to perform actions required for surgical procedures via tool heads 21; the tool head 21 refers to the direct execution instrument on the surgical robot 1 that participates in surgical procedures. Different tool heads 21 may have different functions, and may include needle forceps, electric hooks, electric shovels, bipolar window forceps, bipolar Maryland forceps, cardill forceps, intestinal forceps, tweezers, graspers, needles, scalpels, scissors, cauterizers, endoscopes, and anastomosing devices, etc. The tool head 21 can be mounted on the distal end of the surgical arm 2 via a docking port, drive cable 33, or other structures; the distal end of the surgical arm 2 refers to the end of the surgical arm 2 used to insert into the human body and perform surgical procedures.

[0039] Please see Figure 2 , Figure 2 This is a schematic diagram of the overall structure of the surgical arm 2 shown in some embodiments of this application. For example... Figure 2 As shown, the surgical arm 2 may include an instrument box 22, a flexible joint component 3, an instrument tube 23, and a tool head 21. The flexible joint component 3 may include at least one flexible joint assembly 30. One end of the flexible joint component 3 can be connected to the instrument box 22 via the instrument tube 23, and the other end of the flexible joint component 3 can be connected to the tool head 21.

[0040] In this embodiment, the flexible joint component 3 or flexible joint assembly 30 refers to a structure composed of at least one snake-bone joint 4, which can tighten or loosen via a drive cable 33 to achieve directional deflection; the instrument box 22 refers to a device that can drive the tool head 21, the flexible joint assembly 30, or the instrument straight tube 23 to move via a transmission structure and a power source (such as a servo motor or other components).

[0041] In some embodiments, the instrument tube 23 can be a hollow tubular structure; the drive cable 33 for driving the flexible joint component 3 to deflect can extend and pass through the flexible joint component 3, and extend into the instrument box 22 through the inside of the instrument tube 23, and be wound and connected to the transmission structure in a specified winding direction. Thus, the instrument box 22 can drive the transmission structure to rotate by starting the power source, thereby retracting or releasing the drive cable 33 by a certain distance, so that the flexible joint component 3 deflects in a specified direction at a specified deflection angle.

[0042] In some embodiments, the instrument tube 23 can also be rotatably mounted on the instrument case 22 to enable the self-rotation of the flexible joint component 3, thereby adjusting the movement orientation of the tool head 21 or the deflection orientation of the flexible joint component 3. In some embodiments, the tool head 21 can also be connected to the transmission structure and power source within the instrument case 22 via a tool drive cable 33 or other transmission mechanism. Thus, the instrument case 22 can achieve the movement of the tool head 21 (e.g., gripping with tweezers, insertion and withdrawal of needles, etc.) or the self-rotation of the instrument tube 23 by activating the power source.

[0043] The instrument tube 23 supports the flexible joint component 3 and the tool head 21 and assists in bending. In some embodiments, the instrument tube 23 may be made of materials such as steel pipe and have a slit cut in the middle section. The length of the instrument tube 23 is determined by the trocar travel of the surgical robot 1, which refers to the distance or range that the surgical instrument (surgical arm 2 or tool head 21) enters the patient's body through the trocar during the operation.

[0044] Please see Figures 3 to 4 , Figure 3 This is a schematic diagram of the structure of the second flexible joint assembly 32 shown in some embodiments of this application; Figure 4 This is a front view schematic diagram of a second flexible joint assembly 32 shown in some embodiments of this application. Figures 2 to 4 As shown, the flexible joint component 3 may include two flexible joint assemblies 30, namely a first flexible joint assembly 31 and a second flexible joint assembly 32.

[0045] Each flexible joint assembly 30 may include at least one snake-bone joint 4 and at least two drive cables 33. Furthermore, each drive cable 33 extends and passes through each snake-bone joint 4, and the connection position (or passing position) of the drive cable 33 on each snake bone 5 (or snake-bone joint 4) is symmetrical about the pivot 51 of the current snake-bone joint 4. One end of each drive cable 33 can be fixed to the most distal snake bone 5 in the corresponding flexible joint assembly 30, where the most distal snake bone 5 refers to the snake bone 5 closest to the tool head 21 within the same flexible joint assembly 30. Thus, the surgical instrument box 22 can control the retraction and extension of the drive cables 33 on both sides of the snake-bone joint 4 to achieve bending or repositioning of the snake-bone joint 4 to one side, and deflection of the flexible joint assembly 30 to one side, thereby achieving the specified posture of the tool head 21.

[0046] In some embodiments, each flexible joint assembly 30 can achieve reciprocating deflection in at least two degrees of freedom through a plurality of serpentine joints 4. Further, each flexible joint assembly 30 can include at least two serpentine joints 4 whose bending directions are perpendicular to each other (i.e., the two pivots 51 are perpendicular to each other). For example, in the second flexible joint assembly 32, a plurality of serpentine joints 4 are stacked sequentially along the same straight line direction.

[0047] In some embodiments, where any flexible joint assembly 30 includes at least two serpentine joints 4 with the same pivot extension direction A, the flexible joint assembly 30 may further include at least two constraint cables 34. The constraint cables 34 are used to limit the uncertain deformation of the flexible joint assembly 30, so that it has a uniquely determined posture after being oriented based on a specified deflection angle, thereby mitigating the problem of uncertain deformation (e.g., S-shaped deformation) of the flexible joint assembly 30 due to external load forces.

[0048] Specifically, in the flexible joint assembly 30, each constraint cable 34 extends and passes through multiple snake joints 4. The connection positions 340 (passing positions) of the constraint cables 34 on each snake bone 5 (or snake joint 4) are symmetrical about the pivot 51. Furthermore, between two snake joints 4 that are adjacent in the same pivot extension direction A, the connection position 340 of each constraint cable 34 with the nearest snake bone 5 (snake joint 4) is the first connection position 341, and the connection position 340 of each constraint cable 34 with the farthest snake bone 5 (snake joint 4) is the second connection position 342. The first connection position 341 can be shifted by 180 degrees relative to the second connection position 342 based on the central axis M of the flexible joint assembly 30.

[0049] like Figure 3 , Figure 4 As shown, taking the second flexible joint assembly 32 as an example, the second flexible joint assembly 32 may include a first snake joint 401, a second snake joint 402, a third snake joint 403, and a fourth snake joint 404 arranged sequentially along a straight line M. The pivot extension directions A of the first snake joint 401 and the second snake joint 402 are perpendicular to each other, the pivot extension directions A of the third snake joint 403 and the fourth snake joint 404 are perpendicular to each other, and the pivot extension directions A of the first snake joint 401 and the third snake joint 403 are the same (or parallel to each other).

[0050] Furthermore, the second flexible joint assembly 32 may include four drive cables 33 and four constraint cables 34, all of which extend and pass through each of the snake-bone joints 4. The connection or passage positions of the four drive cables 33 on each snake-bone 5 are symmetrical about the pivot 51. Of the four constraint cables 34, the connection or passage positions of two constraint cables 34 on the snake-bone 5 fall on the pivot 51, and the connection or passage positions of the other two constraint cables 34 on the snake-bone 5 are symmetrical about the pivot 51. Alternatively, the connection or passage positions of the four constraint cables 34 on each snake-bone 5 may also be symmetrical about the pivot 51. Specifically, the connection position 340 between each constraint cable 34 and the snake bone 5 in the second snake bone joint 402 is the first connection position 341, and the connection position 340 between each constraint cable 34 and the snake bone 5 in the fourth snake bone joint 404 is the second connection position 342. The first connection position 341 is 180 degrees shifted based on the central axis M of the second flexible joint assembly 32 compared to the second connection position 342.

[0051] In some embodiments, the first vertical distance between the first connecting position 341 and the central axis M can be equal to the second vertical distance between the second connecting position 342 and the central axis M, so that the bending angles of the two most adjacent snake joints 4 with the same bendable direction are equal; in other embodiments, the first vertical distance between the first connecting position 341 and the central axis M can also be greater than or less than the second vertical distance between the second connecting position 342 and the central axis M, so that the bending angles of the two most adjacent snake joints 4 with the same bendable direction are fixed but not equal.

[0052] In the above technical solution, by connecting at least two constraint cables 34 of the snake joint 4 in a 180-degree shift arrangement based on the central axis M, the two snake joints 4 that are closest in position and have the same pivot extension direction A can each have a fixed bending angle when they deflect to the same side at a specified angle. This is because the length of the multiple constraint cables 34 symmetrically arranged based on the pivot 51 is fixed, and the constraint position (i.e., connection position 340 or insertion position) between the constraint cables 34 and the snake joint 4 is fixed. When a constraint cable 34 is pulled to one side by a bending snake joint 4, since the length of each constraint cable 34 remains unchanged and the connection position 340 is fixed, the other snake joint 4 will also be pulled by the constraint cable 34 and bend and displace accordingly. The two snake joints 4 can achieve a unique bending angle by the 180° shift arrangement of at least two constraint cables 34 and the constraint connection at the specified position.

[0053] Please see Figure 5 , Figure 5 This is a schematic diagram of the overall structure of the snake-bone joint 4 shown in some embodiments of this application. For example... Figure 5 As shown, this application embodiment provides a snake-bone joint 4, which includes two snake bones 5 capable of relative rotation through the contact and engagement of protrusions and grooves. Within the same snake-bone joint 4, both snake bones 5 are capable of rotation based on their respective pivots 51. The two pivots 51 are parallel to each other and have a constant distance between them. The distance between the two pivots 51 is the center distance H of the snake-bone joint 4.

[0054] In some embodiments, the snake-bone joint 4 may include a first snake-bone 501 and a second snake-bone 502, both of which are rotatable based on their respective pivots 51. The two pivots 51 are parallel and have a constant distance between them. Specifically, the first snake-bone 501 includes a constraint roller 52, and the second snake-bone 502 includes a constraint hole 53. The constraint roller 52 is movably disposed within the constraint hole 53. The constraint hole 53 includes a first constraint surface 531 and a second constraint surface 532 disposed opposite to each other. The constraint roller 52 disposed within the constraint hole 53 is sandwiched between the first constraint surface 531 and the second constraint surface 532.

[0055] In this embodiment, the snake bone 5 refers to the joint unit used to form the snake bone joint 4 and support the snake bone joint 4 to achieve bending movement; the constraint hole 53 and the constraint roller 52 refer to the structures that can support the rotation of the snake bone 5 through contact engagement and directional movement, and can also generate relative or opposite forces through the simultaneous contact of the two opposite constraint surfaces in the constraint hole 53 and the constraint roller 52, thereby applying bidirectional constraint force to each snake bone 5 to achieve limiting constraint on the movement of the snake bone 5, so as to reduce or even avoid uncertain lateral sliding between the snake bones 5.

[0056] Please combine Figures 6 to 7 As shown, in the same snake joint 4, when the pivots 51 of the two snake bones 5 are parallel and the center distance H is constant, the constraint protrusion simultaneously contacts and adheres to the first constraint surface 531 and the second constraint surface 532, which are oppositely arranged in the constraint hole 53, so that the snake bone 5 is subjected to constraint forces in two directions at the same time. Specifically, during the bending process of the snake joint 4, or when the snake joint 4 maintains a certain posture at a fixed bending angle, the constraint roller 52 adheres to the first constraint surface 531 at a first position, and the constraint roller 52 adheres to the second constraint surface 532 at a second position. The pressure exerted by the first constraint surface 531 on the constraint roller 52 at the first position due to the tension of the drive cable 33 is the first constraint force F1, and the pressure exerted by the second constraint surface 532 on the constraint roller 52 at the second position due to the tension of the drive cable 33 is the second constraint force F2.

[0057] For the first serpentine 501 equipped with constraint rollers 52, when the serpentine joint 4 bends to a certain angle, it is simultaneously subjected to constraint forces F1 and F2 in two directions. The horizontal components of these two constraint forces are relative and equal. The first serpentine 501 will no longer slide or misalign to either side, but will be constrained and balanced in its current position. The same applies to the second serpentine 502. Thus, the two serpentine 5s in the same serpentine joint 4 can rotate and engage through the movement of the constraint rollers 52 within the constraint groove to support the bending action of the serpentine joint 4. Furthermore, at any bending angle, each serpentine 5 can be constrained by bidirectional forces through the contact of the constraint rollers 52 with the two opposing constraint surfaces, thereby reducing the probability of lateral misalignment and sliding of the serpentine 5 and achieving a symmetrical motion configuration of the serpentine joint 4.

[0058] In this embodiment of the application, two snake bones 5 (e.g.) Figures 5 to 6 The first snake bone 501 and the second snake bone 502 rotate relative to each other to achieve the bending action of the snake bone joint 4. Assuming that the second snake bone 502 (snake bone 5 with constraint hole 53) remains stationary, and the first snake bone 501 (snake bone 5 with constraint roller 52) rotates relative to the second snake bone 502 and maintains a symmetrical motion configuration with the second snake bone 502, then the second snake bone 502 applies horizontal components of constraint forces F1 and F2 to the first snake bone 501. That is, the components of the two constraint forces projected onto the first end face 50 of the second snake bone 502, which can also be understood as the direction of the horizontal component of the constraint force being parallel to the first end face 50 of the second snake bone 502.

[0059] Without the constraint rollers 52 and constraint holes 53 to restrict the snake bone 5 from sliding misaligned to either side, the flexible joint assembly 30 and the snake bone joint 4 do not have a uniquely determined posture when bending based on a specified bending angle. Assuming the snake bone joint 4 completes the bending action based on a specified bending angle (60 degrees), and the two snake bones 5 rotate relative to each other in an ideal state (symmetrical configuration) to achieve the bending of the snake bone joint 4, for example, the two snake bones 5 rotate towards each other based on their respective pivots 51, each rotating 30 degrees, when the surgical arm 2 performs surgical operations based on the snake bone joint 4 in this posture, the snake bone joint 4 may still change to other postures due to external force interference, i.e., uncertain bending deformation occurs. For example, when the tool head 21 enters the human body and comes into contact with an organ or blood vessel, the contact pressure is transmitted from the tool head 21 to the snake joint 4. The two snake bones 5 may change from rotating 30 degrees to one rotating 20 degrees and the other 40 degrees. The snake joint 4 changes to other postures at the specified bending angle and no longer maintains a symmetrical configuration. This makes it impossible for the tool head 21 to apply force to the surgical target position to perform the surgical operation, and may even cause incorrect wounds due to the sudden change in the surgical target position caused by external force. Therefore, the two snake bones 5 constituting the flexible snake joint 4 need the cooperation of the constraint roller 52 and the constraint hole 53 to achieve the application of bidirectional constraint force on either snake bone 5. Furthermore, through the counterbalancing and equilibrium of the horizontal components of the constraint force, the symmetrical motion configuration of the two snake bones 5 is achieved, reducing the probability of the snake joint 4 undergoing uncertain deformation (which can be called S-shaped deformation or parallelogram deformation) or achieving a specified bending angle in an uncertain posture due to external force.

[0060] In the above technical solution, with the pivots 51 of the two snake bones 5 parallel and the distance between them constant, the constraint roller 52 is movably disposed within the constraint hole 53 to support the bending action of the snake bone joint 4, making the assembly of the snake bone joint 4 simpler and more efficient. Furthermore, the constraint roller 52, sandwiched between the first constraint surface 531 and the second constraint surface 532, ensures that regardless of the degree of bending of the snake bone joint 4 or the location of the constraint roller 52 within the constraint hole 53, the contact between the constraint hole 53 and the constraint roller 52 provides bidirectional limiting for the two snake bones 5, restricting uncertain lateral sliding between them, improving the bending accuracy and load deformation resistance of the snake bone joint 4, and achieving a symmetrical motion configuration during the bending process of the snake bone joint 4. Moreover, the constraint roller 52, sandwiched between the two constraint surfaces, makes the force distribution of the two snake bones 5 more uniform, reducing local stress concentration, further reducing wear on the snake bone 5, and making the rotation of the snake bone 5 smoother and more fluid.

[0061] In the same snake-bone joint 4, the adjacent end faces of the two snake bones 5 are the first end faces 50. In some embodiments, the snake-bone joint 4 further includes at least one support structure 41, which is disposed between the first end faces 50 of the two snake bones 5. The support structure 41 is used to define a constant distance between the two pivots 51, thereby limiting the centers of the two snake bones 5 from moving closer or further apart, that is, maintaining a constant center distance H of the snake-bone joint 4. The support structure 41 can be a separate component or integrally formed with the snake bones 5; the pivot 51 generally refers to the axial position on which the snake bones 5 rotate when the snake-bone joint 4 bends.

[0062] In the above technical solution, the support structure 41 can share the pressure load of the snake bones 5. The pressure load refers to the force generated between the two snake bones 5 that make up the snake bone joint 4 due to the tightening of the drive cable 33. Furthermore, the support structure 41 can reduce the wear of the snake bones 5 and extend the service life of the snake bones 5 and the snake bone joint 4. Through the support structure 41, or the cooperation between the support structure 41 and the drive cable 33, the center distance H between the two snake bones 5 is kept constant, so as to further realize the symmetrical motion configuration of the snake bone joint 4 and effectively improve the bending accuracy and bending stability of the snake bone joint 4.

[0063] In some embodiments, the snake-bone joint 4 further includes at least one connecting pin 411. Each connecting pin 411 includes two connecting shafts 4111 and a connecting rod 4112. The connecting rod 4112 is vertically connected between the two parallel connecting shafts 4111 and can be integrally formed with the two connecting shafts 4111. In the snake-bone joint 4, each connecting shaft 4111 is rotatably connected to the first snake bone 501 or the second snake bone 502, and the axis of each connecting shaft 4111 is fixedly aligned with the pivot 51. Specifically, the connecting shaft 4111 has a cylindrical structure, and each snake bone 5 has a circular hole at the pivot 51 position for accommodating the connecting shaft 4111. One connecting shaft 4111 of each connecting pin 411 is inserted into the circular hole of one snake bone 5 to achieve a rotatable connection between the snake bone 5 and the connecting pin 411.

[0064] In the above technical solution, the snake joint 4 fixes the center distance H between the pivots 51 of the two snake bones 5 through the connecting pin 411, so that while the two snake bones 5 can rotate relative to each other, the pivots 51 are difficult to get closer or farther apart, thereby improving the bending accuracy and bending reliability of the snake joint 4. Furthermore, the connection method between the connecting pin 4111 and the snake bone 5 is usually a contact fit between a round hole and a cylindrical surface, which has a stronger load capacity and better bending performance of the snake joint 4.

[0065] In other embodiments, the support structure 41 may also employ an arc-shaped top-facing unit to constrain the center distance H of the snake joint 4. Specifically, in the same snake joint 4, the surfaces of the two snake bones 5 that are opposite and adjacent to each other are first end faces 50. Each support structure 41 may include two arc-shaped top-facing units, which may be respectively disposed on the first end faces 50 of the two snake bones 5 that are opposite and adjacent to each other, and may be integrally formed with the snake bones 5. Each arc-shaped top-facing unit has an arc-shaped top-facing surface, and the arc-shaped top-facing surfaces on the two snake bones 5 are arranged opposite each other and in rolling contact, and the radii of the two arc-shaped top-facing surfaces are equal. The axis of the arc-shaped top-facing surface coincides with the pivot 51, and the radius of the arc-shaped top-facing surface is equal to half of the center distance H of the snake joint 4.

[0066] In the above technical solution, the setting of the arc on the top surface can reduce the wear of the snake bone 5. The arc on the top surface is in rolling contact with each other and the radius is half of the center distance H. This makes it difficult for the pivot 51 of the two snake bones 5 to get close to each other when they rotate relative to each other, thereby improving the smoothness of the bending of the snake bone joint 4 and the stability of the structure, improving the load-bearing capacity of the snake bone joint 4, and reducing the processing and assembly difficulty of the snake bone joint 4.

[0067] In the above technical solution, the snake joint 4 can fix the center distance H between the two snake bones 5 through various types of support structures 41, so that the pivots 51 of the two snake bones 5 are difficult to approach or move away from each other during the rotation process (the rolling contact of the arc-shaped top unit and the tightening connection of the drive cable 33 to the two snake bones 5 can make it difficult for the two snake bones 5 to move away or approach each other, and the connecting pin 411 can also play the same role). The constant center distance H ensures that the pivots 51 of the two snake bones 5 will not suddenly approach or move away from each other under the tension of the drive cable 33, thereby reducing the probability of the snake joint 4 accidentally "colliding" or "dislocating".

[0068] Please see Figure 6 , Figure 6 This is a front view schematic diagram of the snake-bone joint 4 shown in some embodiments of this application. For example... Figure 6 As shown in the embodiment of this application, the snake-bone joint 4 includes a first snake bone 501 and a second snake bone 502. The pivot 51 of the first snake bone 501 is a first pivot 511, and the pivot 51 of the second snake bone 502 is a second pivot 512. The opposite and adjacent end faces of the first snake bone 501 and the second snake bone 502 are first end faces 50, which are parallel to or coincide with the first pivot 511 and the second pivot 512. The first snake bone 501 also includes a first connecting portion 520, through which the constraint roller 52 is connected to the first end face 50. Furthermore, the snake bone body containing the constraint roller 52, the first connecting portion 520, and the first end face 50 can be integrally formed.

[0069] In some embodiments, the central axis of the constraint roller 52 may be parallel to the first pivot 511. Both the first pivot 511 and the central axis of the constraint roller 52 coincide with the same plane, which is perpendicular to the first end face 50. In this embodiment, the plane shared by the central axis of the constraint roller 52 and the first pivot 511 is perpendicular to the first end face 50, such that the constraint roller 52 and the first connecting portion 520 are arranged perpendicularly to the first end face 50 of the first serpentine joint 501. Therefore, the first serpentine joint 501 and the overall structure of the serpentine joint 4 in a straight state have better symmetry (please refer to...). Figure 7 (As shown). When the snake joint 4 is in a straight state, it usually means that when the first end faces 50 of the two snake bones 5 are parallel to each other, the first pivot 511 and the second pivot 512 are aligned and parallel in the vertical direction.

[0070] In the above technical solution, the design that the central axis of the constraint roller 52 is parallel to the first pivot 511 and the plane in which they are located is perpendicular to the first end face 50 gives the snake joint 4 and snake bone 5 components in the straight state better symmetry and consistency, which helps the snake bone 5 to be subjected to uniform and stable force and reduce wear. In addition, this vertical alignment method makes the manufacturing, assembly and motion control of the snake joint 4 simpler and more intuitive, which is conducive to improving the motion accuracy of the snake joint 4 and the motion consistency of each component in the snake joint 4, thereby improving the overall performance of the snake joint 4.

[0071] Furthermore, the vertical distance 'a' between the central axis of the constraint roller 52 and the first pivot 511 is less than the center distance H. In this embodiment, the setting that the vertical distance 'a' between the constraint roller 52 and the first pivot 511 is less than the center distance H ensures that the engagement and relative movement between the constraint roller 52 and the constraint hole 53 are typically located between the first snake bone 501 and the second snake bone 502. This makes the overall structure of the snake bone joint 4 simpler and more compact, reducing the processing and assembly difficulty of the snake bone joint 4.

[0072] In some embodiments, the constraint hole 53 further includes a first limiting end face 533 and a second limiting end face 534. Specifically, the first limiting end face 533 is disposed at one end of the first constraint surface 531 and the second constraint surface 532, and the second limiting end face 534 is disposed at the other end of the first constraint surface 531 and the second constraint surface 532. Both the first limiting end face 533 and the second limiting end face 534 are used to limit the maximum rotation angle of the first snake bone 501 relative to the second snake bone 502. When the constraint roller 52 moves to the first limiting end face 533 within the constraint hole 53, the rotation angle of the first snake bone 501 relative to the second snake bone 502 towards one side stops increasing because the constraint roller 52 is blocked by the first limiting end face 533; when the constraint roller 52 moves to the second limiting end face 534 within the constraint hole 53, the rotation angle of the first snake bone 501 relative to the second snake bone 502 towards the other side stops increasing because the constraint roller 52 is blocked by the second limiting end face 534.

[0073] Furthermore, the first limiting end face 533 and the second limiting end face 534 can be configured as planes; the first limiting end face 533 and the second limiting end face 534 can also be configured as arc surfaces that conform to the outer contour of the constraint roller 52, so as to reduce the wear of the constraint roller 52. In this embodiment, the extension length and bending arc of the first limiting end face 533 to the second limiting end face 534 are generally related to the preset maximum bendable angle of the snake joint 4.

[0074] In the above technical solution, the setting of the first limiting end face 533 and the second limiting end face 534 can limit the maximum relative rotation angle of the two snake bones 5 and the maximum bendable angle of the snake bone joint 4, reduce the probability of damage to the snake bone joint 4 caused by excessive rotation of the snake bones 5, and enable the snake bone joint 4 to achieve bending movement more smoothly and accurately within the preset bendable angle range, thereby improving the reliability and durability of the snake bone joint 4.

[0075] The following will briefly explain the design principles of the first constraint surface 531 and the second constraint surface 532 in the constraint hole 53. Please refer to [link / reference]. Figure 7 , Figure 7 This is a schematic diagram illustrating the geometric principle of the snake-like joint 4 in some embodiments of this application. For example... Figure 7As shown, since the bending motion of the snake joint 4 is based on the cooperation and relative rotation of the two snake bones 5, assuming the second snake bone 502 remains stationary, the first snake bone 501 maintains a symmetrical motion configuration with the second snake bone 502 during its rotation relative to the second snake bone 502. Alternatively, assuming the second snake bone 502 remains stationary, the first pivot 511 and the second pivot 512 are always parallel and their center distance H remains constant, and the first snake bone 501 and the second snake bone 502 are always symmetrical about the perpendicular bisector (perpendicular plane) of the line connecting the center points of the two pivots 51. Therefore, the first constraint surface 531 and the second constraint surface 532 corresponding to the constraint hole 53 on the second snake bone 502 can be calculated based on the simulated motion trajectory of the outer contour of the constraint roller 52 on the first snake bone 501.

[0076] In some embodiments, the constraint roller 52 is a cylindrical roller, the first constraint surface 531 can extend according to the first curve 5301, and the second constraint surface 532 can extend according to the second curve 5302. For example... Figure 7 As shown, the first curve 5301 and the second curve 5302 can be considered as the two side contour lines of the movement trajectory formed by the target circle 530 as it rotates with the first serpentine 501 on the assumed stationary second serpentine 502. The target circle 530 can be considered as the cross-section of a cylindrical roller, with its center coinciding with the central axis of the cylindrical roller, and its radius equal to the radius of the cylindrical roller. Assuming that the first serpentine 501 and the second serpentine 502 maintain a symmetrical motion configuration, the pivot 51 is parallel, and the center distance H remains constant, the first curve 5301 and the second curve 5302 can be formed by fitting the contour points at the outermost edges of the movement trajectory formed by the target circle 530 rotating with the first serpentine 501.

[0077] In the above technical solution, the extended shapes of the first constraint surface 531 and the second constraint surface 532, as well as the distance between them, are obtained based on the motion trajectory of the target circle 530 corresponding to the constraint roller 52. This allows the constraint roller 52 to move more smoothly and flexibly within the constraint hole 53, improving the smoothness and stability of the bending of the serpentine joint 4. The center of the target circle 530 coincides with the central axis of the cylindrical roller, and the radius of the target circle 530 is equal to the radius of the cylindrical roller, which improves the positioning accuracy of the constraint roller 52 within the constraint hole 53, thereby improving the bending accuracy of the serpentine joint 4. The constraint roller 52 is a cylindrical roller, and the first constraint surface 531 and the second constraint surface 532 are generated based on the motion trajectory of the cylindrical roller, ensuring that the constraint roller 52 and the two constraint surfaces always maintain a tangential arc contact relationship, improving the load capacity of the serpentine joint 4, reducing local stress concentration, and extending the service life of the serpentine joint 4.

[0078] Based on this, since the outer contours of the constraint roller 52 and the first constraint surface 531 are tangent when they are in contact, and the outer contours of the constraint roller 52 and the second constraint surface 532 are tangent when they are in contact, when the snake joint 4 achieves bending action by retracting and extending the drive cables 33 on both sides of the pivot 51, the force exerted by the first constraint surface 531 on the constraint roller 52 is the first constraint force F1, and the force exerted by the second constraint surface 532 on the constraint roller 52 is the second constraint force F2. The directions of the first constraint force F1 and the second constraint force F2 are usually perpendicular to the central axis of the constraint roller 52 or directly to the center point of the constraint roller 52. Based on this, since both the first constraint surface 531 and the second constraint surface 532 are formed by fitting the outermost contour point extracted from the simulated motion trajectory of the same constraint roller 52 relative to the second snake bone 502, the first constraint force F1 and the second constraint force F2 on the constraint roller 52 and the first snake bone 501 are usually equal in magnitude and opposite in direction. The horizontal components of the first constraint force F1 and the second constraint force F2 are also opposite in direction and equal in magnitude. The horizontal component is the component of the two constraint forces in the first direction, which is parallel to the first end face 50 of the second snake bone 502. Thus, the first snake bone 501 is constrained and balanced in its current position, and the same applies to the second snake bone 502. Furthermore, the snake bone joint 4 can achieve a unique shape at a specified bending angle, that is, the first snake bone 501 and the second snake bone 502 can achieve a symmetrical motion configuration during relative rotation.

[0079] Please see Figure 8 , Figure 8 This is a schematic diagram of the overall structure of the first snake bone 501 shown in some embodiments of this application. For example... Figures 5 to 8 As shown, both the first snake bone 501 and the second snake bone 502 have multiple sets of rope holes 54. The rope holes 54 can be symmetrically arranged on both sides of the pivot 51. Each rope hole 54 is located on the first end face 50 and extends in a direction perpendicular to the first end face 50. The rope holes 54 are used to accommodate the drive cable 33 or the constraint cable 34. Furthermore, the multiple rope holes 54 for accommodating the drive cable 33 and the multiple rope holes 54 for accommodating the constraint cable 34 are independent of each other.

[0080] Please combine Figure 7 As shown, when the connection positions (penetration positions) of the drive cables 33 on both sides of the snake joint 4 and each snake bone 5 are symmetrical and equidistant from the pivot 51, the snake joint 4, which is bent from a straight state to any angle, can form an isosceles trapezoidal shape (in extreme cases, it may be an isosceles triangle) motion configuration with the drive cables 33. When the drive cables 33 on both sides of the snake joint 4 are pulling the snake joint 4 to bend, the shortening length of one side of the cable is equal to the elongation length of the other side of the cable, that is, the drive cables 33 on both sides of the snake joint 4 are stretched and stretched in the same way.

[0081] Furthermore, the vertical distance between the drive cables 33 on both sides of the pivot 51 and the center points of the two pivots 51 (first pivot 511 and second pivot 512), or between the lines connecting the centers of the two pivots 51 and the plane where the two pivots 51 are located, can be considered as the lever arm of the drive cables 33 when the snake joint 4 is in any posture, and when one side of the drive cable 33 tightens to drive the snake joint 4 to continue bending, or when the other side of the drive cable 33 tightens to drive the snake joint 4 to return to its original position. Figure 7 For example, when the snake joint 4 is already bent to the left, the lever arm required for the left drive cable 33 to tighten and drive the snake joint 4 to continue bending to the left is equal to the lever arm required for the right drive cable 33 to tighten and drive the snake joint 4 to return to a straight position to the right. This state of equal lever arm can be considered as lever arm balance. Lever arm balance can be understood as the force required to tighten the drive cable 33 on either side of the snake joint 4 is equal regardless of its posture or which side it is about to bend. Therefore, under lever arm balance, the probability of deformation of the drive cables 33 on both sides of the snake joint 4 is reduced. The above technical solution can effectively alleviate the problem of excessive difference in force deformation of the drive cables 33 on both sides due to the long-term accumulation of lever arm imbalance, reduce wear of the drive cables 33, improve the service life of the drive cables 33, and also improve the consistency of the service life of each drive cable 33.

[0082] In the above technical solution, the symmetrical arrangement of multiple sets of rope holes 54 makes the overall structure of the snake joint 4 more compact, and can also reduce the entanglement and interference of the constraint cable 34 or drive cable 33 on the movement of the snake bone 5 when they rotate relative to each other. Furthermore, the symmetrical arrangement of multiple sets of rope holes 54 makes the connection positions of the drive cables 33 on both sides of the snake joint 4 and each snake bone 5 symmetrical and equidistant based on the pivot 51. When the snake joint 4 can achieve a symmetrical motion configuration, the drive cables 33 on both sides of the snake joint 4 can achieve consistent extension and retraction and balanced lever arm, thereby extending the service life of the drive cables 33.

[0083] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A snake-bone joint, comprising a first snake bone and a second snake bone, both the first and second snake bones being rotatable based on their respective pivots, the two pivots being parallel and having a constant distance between them; characterized in that, The first snake bone includes a constraint roller, and the second snake bone includes a constraint hole, wherein the constraint roller is movably disposed within the constraint hole; The constraint hole includes a first constraint surface and a second constraint surface that are arranged opposite to each other, and the constraint roller disposed in the constraint hole is sandwiched between the first constraint surface and the second constraint surface.

2. The snake-bone joint according to claim 1, characterized in that, The pivot of the first snake bone is a first pivot, and the first snake bone includes a first end face and a first connecting portion. The first end face is parallel to or coincides with the first pivot; the constraint roller is connected to the first end face through the first connecting portion. The central axis of the constraint roller is parallel to the first pivot. Both the first pivot and the central axis of the constraint roller coincide with the same plane, which is perpendicular to the first end face.

3. The snake-bone joint according to claim 2, characterized in that, In the snake-bone joint, the distance between the two pivots is the center distance, and the vertical distance between the central axis of the constraint roller and the first pivot is less than the center distance.

4. The snake-bone joint according to any one of claims 1-3, characterized in that, The constraining roller is a cylindrical roller, the first constraining surface extends according to a first curve, and the second constraining surface extends according to a second curve; The first curve and the second curve are the two side contour lines of the movement trajectory formed on the second snake bone when the target circle follows the rotation of the first snake bone. The center of the target circle coincides with the central axis of the cylindrical roller, and the radius of the target circle is equal to the radius of the cylindrical roller.

5. The snake-bone joint according to any one of claims 1-3, characterized in that, The constraint hole also includes a first limiting end face and a second limiting end face. The first limiting end face is located at one end of the first constraint surface and the second constraint surface, and the second limiting end face is located at the other end of the first constraint surface and the second constraint surface. Both the first limiting end face and the second limiting end face are used to limit the maximum rotation angle of the first snake bone relative to the second snake bone.

6. The snake-bone joint according to any one of claims 1-3, characterized in that, Both the first and second snake bones have multiple sets of rope holes, which are symmetrically arranged on both sides of the pivot. The rope holes are used to accommodate drive cables or restraint cables.

7. The snake-bone joint according to claim 6, characterized in that, The snake bone joint also includes two opposing arc-shaped top surfaces that are in rolling contact with each other. The arc-shaped top surfaces are respectively disposed on the first end surfaces of the first snake bone and the second snake bone that are adjacent to each other and opposite to each other. The distance between the two pivots is the center distance, the radius of each arc on the top surface is half of the center distance, and the axis of the arc on the top surface coincides with the pivot.

8. The snake-bone joint according to claim 6, characterized in that, The snake-bone joint further includes at least one connecting pin, which includes two connecting pin shafts and a connecting rod. The connecting rod is vertically connected between the two parallel connecting pin shafts. In the snake-bone joint, the connecting pin shaft is rotatably connected to the first snake bone or the second snake bone and coincides with the pivot.

9. A flexible joint assembly, characterized in that, The flexible joint assembly includes: At least two snake-bone joints as described in any one of claims 1-8; wherein the pivotal extension directions of at least two of the snake-bone joints are the same; At least two drive cables and at least two constraint cables, each of the drive cables and each of the constraint cables extending and passing through each of the snake joints; the connection positions of the constraint cables on the snake joints are symmetrical about the pivot axis. Between two snake joints that extend in the same direction and are adjacent in position, the connection position of each constraint cable to the nearest snake joint is a first connection position, and the connection position of each constraint cable to the farthest snake joint is a second connection position. The first connection position is shifted by 180° relative to the second connection position based on the central axis of the flexible joint assembly.

10. A surgical operating arm, characterized in that, The surgical arm includes at least one flexible joint assembly as described in claim 9.

Images