Snake bone joint, flexible arm, instrument rod and surgical robot

Abstract

The utility model discloses a snake bone joint, a flexible arm, an instrument rod and a surgical robotic.The snake bone joint comprises a first snake bone component and a second snake bone component, the first snake bone component rotates relative to a first rotating shaft, the second snake bone component rotates relative to a second rotating shaft, and the first rotating shaft and the second rotating shaft are parallel and both located in a first plane; a first limiting part is arranged on the first snake bone component, and a second limiting part matched with the first limiting part is arranged on the second snake bone component; the first limiting part is provided with a first side face located on one side of the first plane and a second side face located on the other side of the first plane. The second limiting part is provided with a third side face located on one side of the first plane and matched with the first side face and a fourth side face located on the other side of the first plane and matched with the second side face. The contour line of the first side surface and the contour line of the third side surface are conjugate curves; the contour line of the second side face and the contour line of the fourth side face are conjugate curves. According to the invention, the snake bone joint can realize symmetrical rotation.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a snake-bone joint, a flexible arm, an instrument rod, and a surgical robot. Background Technology

[0002] Currently, various surgical robots are in use. Surgical robots contain an instrument rod, which typically includes a sequentially connected instrument box, a straight tube, a flexible arm, an end effector, and multiple drive components. The flexible arm contains multiple sequentially connected snake-like joints. One end of each drive component passes through the flexible arm, and the other end connects to a drive unit within the instrument box. Each snake-like joint consists of a first snake-like component and a second snake-like component. The first snake-like component rotates around a first rotation axis, and the second snake-like component rotates around a second rotation axis. The first and second rotation axes are parallel and both lie within a first plane. Multiple drive components are symmetrically arranged on both sides of the first plane. During surgery, part of the flexible arm and the end effector are inserted into the patient's body. The surgeon remotely controls the drive unit to rotate, shortening the drive cable on one side of the first plane and lengthening the drive cable on the other side, causing the snake-like joint to rotate. When the snake-like joint rotates, the first snake-like component rotates around the first rotation axis, and the second snake-like component rotates around the second rotation axis. When multiple serpentine joints rotate in the manner described above, the flexible arm bends in the corresponding direction, moving the end effector as it bends. Once the flexible arm has bent to a preset angle, the end effector reaches the designated position. After the end effector reaches the designated position, surgical procedures can be performed on the patient by manipulating it.

[0003] However, in practice, symmetrical rotation cannot be achieved in the snake joint, that is, the rotation angle of the first snake component and the rotation angle of the second snake component cannot be kept equal, resulting in low motion accuracy of the snake joint. Utility Model Content

[0004] The purpose of this application is to provide a snake-bone joint, a flexible arm, an instrument rod, and a surgical robot, wherein the snake-bone joint can achieve symmetrical rotation and has high motion precision.

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

[0006] In a first aspect, this application provides a snake-bone joint, which includes a first snake-bone component and a second snake-bone component. The first snake-bone component rotates relative to a first rotation axis, and the second snake-bone component rotates relative to a second rotation axis. The first and second rotation axes are parallel and both lie within a first plane. The snake-bone joint also includes a support structure connecting the first and second snake-bone components. The first snake-bone component has a first surface and a first limiting portion. The second snake-bone component has a second surface opposite to the first surface and a second limiting portion that mates with the first limiting portion. The first and second limiting portions are in a concave-convex fit. The first limiting portion has a first side surface located on one side of the first plane, a second side surface located on the other side of the first plane, a third side surface located on one side of the first plane and mates with the first side surface, and a fourth side surface located on the other side of the first plane and mates with the second side surface. The contour lines of the first and third side surfaces are conjugate curves. The contour lines of the second and fourth side surfaces are conjugate curves.

[0007] In one embodiment, the first limiting part is a groove, and the first limiting part also has a first arc surface connecting the first side surface and the second side surface; the second limiting part is a protrusion, and the second limiting part also has a target plane connecting the third side surface and the fourth side surface.

[0008] In one embodiment, the contour line of the first side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve; the contour line of the third side is the conjugate curve of the contour line of the first side.

[0009] In one embodiment, the contour line of the third side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve; the contour line of the first side is the conjugate curve of the contour line of the third side.

[0010] In one embodiment, the contour line of the second side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve; the contour line of the fourth side is the conjugate curve of the contour line of the second side.

[0011] In one embodiment, the contour line of the fourth side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve; the contour line of the second side is the conjugate curve of the contour line of the fourth side.

[0012] In one embodiment, the support structure includes a first unit disposed on a first surface and a second unit disposed on a second surface. The first unit is provided with a first arcuate surface and the second unit is provided with a second arcuate surface. The first arcuate surface and the second arcuate surface are in contact with each other and have the same radius. The axis of the first arcuate surface coincides with the first rotation axis and the axis of the second arcuate surface coincides with the second rotation axis.

[0013] In one embodiment, the support structure includes a first connector, which includes a first rotating pin, a second rotating pin, and a first connecting portion connecting the first rotating pin and the second rotating pin. A first through hole is provided on the first serpentine member, and a second through hole is provided on the second serpentine member. When the first rotating pin passes through the first through hole and the second rotating pin passes through the second through hole, the axis of the first rotating pin coincides with the first rotation axis; the axis of the second rotating pin coincides with the second rotation axis.

[0014] In one embodiment, two first limiting portions are provided at intervals along the first rotation axis on the first surface, and two second limiting portions are provided at intervals along the second rotation axis on the second surface; the first limiting portions and the second limiting portions are matched one-to-one.

[0015] In one embodiment, the support structure includes a first unit and a third unit spaced apart on a first surface along the extension direction of a first rotation axis, and a second unit and a fourth unit spaced apart on a second surface along the extension direction of a second rotation axis. The first unit has a first arcuate surface, the second unit has a second arcuate surface, the first arcuate surface and the second arcuate surface are in contact with each other and have equal radii, the third unit has a third arcuate surface, and the fourth unit has a fourth arcuate surface, the third arcuate surface and the fourth arcuate surface are in contact with each other and have equal radii, the axes of the first arcuate surface and the third arcuate surface coincide with the first rotation axis, and the axes of the second arcuate surface and the fourth arcuate surface coincide with the second rotation axis.

[0016] In one embodiment, the support structure includes a first connector and a second connector spaced apart along the extension direction of a first rotation axis; the first connector includes a first rotating pin, a second rotating pin, and a first connecting portion connected between the first rotating pin and the second rotating pin; a first through hole is provided on the first serpentine member, and a second through hole is provided on the second serpentine member; when the first rotating pin passes through the first through hole and the second rotating pin passes through the second through hole, the axis of the first rotating pin coincides with the first rotation axis, and the axis of the second rotating pin coincides with the second rotation axis; the second connector includes a third rotating pin, a fourth rotating pin, and a second connecting portion connected between the third rotating pin and the fourth rotating pin; a third through hole is provided on the first serpentine member, and a fourth through hole is provided on the second serpentine member; when the third rotating pin passes through the third through hole and the fourth rotating pin passes through the fourth through hole, the axis of the third rotating pin coincides with the first rotation axis, and the axis of the fourth rotating pin coincides with the second rotation axis.

[0017] In one embodiment, the support structure further includes a limiting member located between the first connector and the second connector, for limiting the first connector and the second connector.

[0018] Secondly, this application provides a flexible arm comprising a plurality of the aforementioned serpentine joints; wherein the plurality of serpentine joints are connected sequentially, and the plurality of serpentine joints include a first serpentine joint and a second serpentine joint whose rotation axes are parallel and both located within the first plane; a first constraint member and a second constraint member are disposed in the first serpentine joint and the second serpentine joint, the distal ends of the first constraint member and the second constraint member being fixed to the distal end of the flexible arm, and the proximal ends of the first constraint member and the second constraint member being fixed to the proximal end of the flexible arm; the first constraint member and the second constraint member are disposed within the first serpentine joint along a direction parallel to the first plane, and after spiraling 180° at the connection between the first serpentine joint and the second serpentine joint, are disposed within the second serpentine joint along a direction parallel to the first plane; wherein the connection positions of the first constraint member and the second constraint member on each serpentine member are symmetrical based on the first plane.

[0019] In one embodiment, the first snake joint is connected to the second snake joint via a straight tube segment, and the first and second constraint members extend spirally 180° at the straight tube segment.

[0020] Thirdly, this application provides an instrument lever, which, in addition to the aforementioned flexible arm, also includes an instrument box, a straight tube, an end tool, and a drive component; wherein, one end of the drive component passes through the flexible arm, and the other end of the drive component passes through the straight tube and is connected to the instrument box.

[0021] Fourthly, this application provides a surgical robot that includes a plurality of the aforementioned instrument levers.

[0022] The advantages of this application compared to the prior art are:

[0023] In this application, the snake joint includes a first snake joint component and a second snake joint component. The first snake joint component is rotatable relative to a first rotation axis, and the second snake joint component is rotatable relative to a second rotation axis. The angle at which the first snake joint rotates around the first rotation axis is equal to the angle at which the second snake joint rotates around the second rotation axis. The snake joint can achieve symmetrical rotation and has high motion accuracy. Attached Figure Description

[0024] 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.

[0025] Figure 1 This is a schematic diagram of the structure of the instrument rod shown in this application;

[0026] Figure 2 This application illustrates the structure of the snake-bone joint. Figure 1 ;

[0027] Figure 3 This application shows a schematic diagram of the structure of the first snake-bone component. Figure 1 ;

[0028] Figure 4 This application illustrates the structure of the second snake-bone component. Figure 1 ;

[0029] Figure 5 This is a schematic diagram showing the positions of the first plane and the second plane as illustrated in this application;

[0030] Figure 6 This application illustrates the movement of the first and second snake-bone components. Figure 1 ;

[0031] Figure 7 This application illustrates the movement of the first and second snake-bone components. Figure 2 ;

[0032] Figure 8 This application illustrates the outlines of the first and third sides. Figure 1 ;

[0033] Figure 9 This application illustrates the outlines of the first and third sides. Figure 2 ;

[0034] Figure 10This application illustrates the outlines of the first and third sides. Figure 3 ;

[0035] Figure 11 This application illustrates the outlines of the first and third sides. Figure 4 ;

[0036] Figure 12 This application illustrates the structure of the snake-bone joint. Figure 2 ;

[0037] Figure 13 This application illustrates the explosion of the snake-bone joint. Figure 1 ;

[0038] Figure 14 This application shows a schematic diagram of the structure of the first snake-bone component. Figure 2 ;

[0039] Figure 15 This application illustrates the structure of the second snake-bone component. Figure 2 ;

[0040] Figure 16 This application illustrates the explosion of the snake-bone joint. Figure 2 ;

[0041] Figure 17 This application illustrates the explosion of the snake-bone joint. Figure 3 ;

[0042] Figure 18 This is a schematic diagram of the flexible arm shown in this application;

[0043] Figure 19 This is a schematic diagram showing the insertion of the first, second, third, and fourth constraint members within the flexible arm.

[0044] Figure 20 This is a schematic diagram of the first projection;

[0045] Figure 21 This is a schematic diagram of the second projection.

[0046] Figure label:

[0047] 1-Instrument lever; 10-Instrument box; 20-Straight tube; 30-Flexible arm; 31-First snake joint; 32-Second snake joint; 33-Third snake joint; 34-Fourth snake joint; 35-Straight tube section; 40-End tool; 310-Snake joint; 311-First snake component; 312-Second snake component; 313-First plane; 314-Second plane; 315-First drive component; 316-Second drive component; 317-First connector; 318 - Second connector; 319 - Limiting member; 3111 - First surface; 3112 - First limiting part; 3113 - First unit; 3114 - First protrusion; 3115 - Third unit; 3116 - Third protrusion; 3121 - Second surface; 3122 - Second limiting part; 3123 - Second unit; 3124 - Second protrusion; 3125 - Fourth unit; 3126 - Fourth protrusion; 3151 - First drive rope; 3152 - Second drive rope; 3153 - 3154 - Third drive rope; 3155 - Fourth drive rope; 3156 - First constraint member; 3157 - Second constraint member; 3158 - Third constraint member; 3171 - First rotating pin; 3172 - First connecting part; 3173 - Second rotating pin; 3174 - First mounting groove; 3181 - Third rotating pin; 3182 - Second connecting part; 3183 - Fourth rotating pin; 3184 - Second mounting groove; 31121 - First side; 311 22 - Second side surface; 31123 - First arc surface; 31131 - First arc surface; 31141 - First through hole; 31151 - Third arc surface; 31221 - Third side surface; 31222 - Fourth side surface; 31223 - Target plane; 31231 - Second arc surface; 31241 - Second through hole; 31251 - Fourth arc surface; 31261 - Fourth through hole; 31721 - First target surface; 31821 - Fourth target surface. Detailed Implementation

[0048] 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.

[0049] 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.

[0050] 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 that the product of this application is usually placed in. 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.

[0051] 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.

[0052] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings.

[0053] This embodiment provides a surgical system, which includes a control terminal and a surgical robot. The surgical robot includes multiple instrument levers 1; as shown... Figure 1 As shown, each instrument lever 1 includes an instrument box 10, a straight tube 20, a flexible arm 30, an end effector 40, and multiple actuators (not shown) connected sequentially from proximal to distal end; for example, the end effector 40 may be a surgical tool for performing surgical procedures, such as an electrocautery device, forceps, stapler, scissors, imaging device (e.g., endoscope or ultrasound probe), and the like.

[0054] The flexible arm 30 contains multiple sequentially connected snake-bone joints. One end of each of the multiple drive components passes through the flexible arm 30, and the other end passes through the straight tube 20 and connects to the drive unit in the instrument box 10. Each snake-bone joint consists of a first snake-bone component and a second snake-bone component. The first snake-bone component rotates around a first rotation axis, and the second snake-bone component rotates around a second rotation axis. The first and second rotation axes are parallel and both lie within a first plane. The multiple drive components are symmetrically arranged on both sides of the first plane. During surgery, part of the flexible arm 30 and the end effector 40 are inserted into the patient's body. The doctor remotely controls the drive unit to rotate, shortening the drive rope on one side of the first plane and lengthening the drive rope on the other side of the first plane, causing the snake-bone joint to rotate. When the snake-bone joint rotates, the first snake-bone component rotates around the first rotation axis, and the second snake-bone component rotates around the second rotation axis. When multiple snake-bone joints rotate in the manner described above, the flexible arm 30 bends in the corresponding direction, and during the bending process, the flexible arm 30 moves the end effector 40; after the flexible arm 30 bends to a preset angle, the end effector 40 reaches the designated position. Once the end effector 40 reaches the designated position, surgical procedures can be performed on the patient by operating the end effector 40.

[0055] However, in practice, symmetrical rotation cannot be achieved when the snake joint rotates, that is, the rotation angle of the first snake component and the rotation angle of the second snake component cannot be kept equal, resulting in low motion accuracy of the snake joint.

[0056] To address the aforementioned problems, this embodiment provides a snake-bone joint. The structure of the snake-bone joint provided in this embodiment will be explained in detail below:

[0057] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, in this embodiment, the snake bone joint 310 includes a first snake bone component 311 and a second snake bone component 312. The first snake bone component 311 rotates relative to the first rotation axis P1, and the second snake bone component 312 rotates relative to the second rotation axis P2. The first rotation axis P1 and the second rotation axis P2 are parallel and both are located in the first plane 313.

[0058] The first snake-bone component 311 has a first surface 3111, and a first limiting portion 3112 is provided on the first surface 3111. The second snake-bone component 312 has a second surface 3121 opposite to the first surface 3111, and a second limiting portion 3122 that cooperates with the first limiting portion 3112. The first limiting portion 3112 and the second limiting portion 3122 are in a concave-convex fit. That is, the first limiting portion 3112 can be a protrusion, and the second limiting portion 3122 can be a groove; or, the first limiting portion 3112 can be a groove, and the second limiting portion 3122 can be a protrusion. The first limiting portion 3112 and the second limiting portion 3122 are engaged by the cooperation of the protrusion and the groove. In this example, the first limiting part 3112 is a groove and the second limiting part 3122 is a protrusion. The first limiting part 3112 has a first side surface 31121 located on one side of the first plane 313, a second side surface 31122 located on the other side of the first plane 313, a third side surface 31221 located on one side of the first plane 313, and a fourth side surface 31222 located on the other side of the first plane 313. When the first limiting part 3112 and the second limiting part 3122 are engaged, the third side surface 31221 engages with the first side surface 31121, and the fourth side surface 31222 engages with the second side surface 31122. Figure 5 As shown, the snake-bone joint 310 also has a second plane 314 orthogonal to the first plane 313. When the first side surface 31121 is projected onto the second plane 314, a curve is obtained, which is the outline of the first side surface 31121. Similarly, when the second side surface 31122 is projected onto the second plane 314, a curve is also obtained, which is the outline of the second side surface 31122. When the third side surface 31221 is projected onto the second plane 314, a curve is also obtained, which is the outline of the third side surface 31221. When the fourth side surface 31222 is projected onto the second plane 314, a curve is also obtained, which is the outline of the fourth side surface 31222. The outlines of the first side surface 31121 and the third side surface 31221 are conjugate curves; the outlines of the second side surface 31122 and the fourth side surface 31222 are also conjugate curves.

[0059] When the first snake-bone component 311 rotates around the first rotation axis P1 and the second snake-bone component 312 rotates around the second rotation axis P2, since the contour lines of the first side surface 31121 and the third side surface 31221 are conjugate curves, there is always a point of contact between the first side surface 31121 and the third side surface 31221 during the rotation of the first snake-bone component 311 and the second snake-bone component 312. For ease of description, this contact point is referred to as the first contact point in this embodiment. There is always a point of contact between the second side surface 31122 and the fourth side surface 31222. For ease of description, this contact point is referred to as the second contact point in this embodiment. The existence of the first contact point allows a first force to be applied to the first snake-bone component 311 when the second snake-bone component 312 rotates, and the existence of the second contact point allows a second force to be applied to the first snake-bone component 311 when the second snake-bone component 312 rotates. The horizontal components of the first force and the second force are opposite in direction, which restricts the first snake-bone component 311 from applying a force to the first snake-bone component 311. Figure 2 The movement of the first snake-bone component 311 in the D1 and D2 directions is restricted, thus limiting its horizontal movement. The presence of the first contact point allows a third force to be applied to the second snake-bone component 312 when the first snake-bone component 311 rotates, and the presence of the second contact point allows a fourth force to be applied to the second snake-bone component 312 when the first snake-bone component 311 rotates. The horizontal components of the third and fourth forces are opposite in direction, thus restricting the horizontal movement of the second snake-bone component 312. Figure 2 The movement of the second snake bone component 312 in the D1 and D2 directions is restricted, which restricts its movement in the horizontal direction.

[0060] The snake-bone joint 310 also includes a support structure connecting the first snake-bone member 311 and the second snake-bone member 312. This support structure is used to maintain a constant distance between the first rotation axis P1 and the second rotation axis P2. While ensuring a constant distance between the first rotation axis P1 and the second rotation axis P2, and restricting the horizontal movement of the first snake-bone member 311 and the second snake-bone member 312, the first snake-bone member 311 can perform a pure rolling motion without relative sliding relative to the second snake-bone member 312, and the second snake-bone member 312 can perform a pure rolling motion without relative sliding relative to the first snake-bone member 311. That is, if... Figure 6 As shown, when K1 is regarded as the first snake bone component 311 and K2 is regarded as the second snake bone component 312, K1 rotates around the first rotation axis P1 while K1 rolls along K2; K2 rotates around the second rotation axis P2 while K2 rolls along K1.

[0061] like Figure 7As shown, if the first snake-bone component 311 rotates clockwise from position P3 to position P4 around the first rotation axis P1, and the second snake-bone component 312 rotates counterclockwise from position P5 to position P6 around the second rotation axis P2, when the extension lines of the first snake-bone component 311 at position P4 and the second snake-bone component 312 at position P6 are drawn, the two extension lines intersect at point E. The perpendicular bisectors P1P2 of the first and second rotation axes P1 and P2 are drawn, and the midpoint F of the perpendicular bisector P1P2 is taken. Connecting points E and F forms a straight line EF. The angle between the straight line EF and the first snake-bone component 311 is b1, and the angle between the straight line EF and the second snake-bone component 312 is b2. The first snake-bone component 311 rotates clockwise from position P3 to position P4, and the second snake-bone component 312 rotates counterclockwise from position P5 to position P6. When the first rotation axis P1 rotates from position P3 to position P4, its rotation angle is also b1. When the second snake bone component 312 rotates around the second rotation axis P2 from position P5 to position P6, its rotation angle is also b2. Since the first snake bone component 311 can perform pure rolling motion without relative sliding relative to the second snake bone component 312, and the second snake bone component 312 can perform pure rolling motion without relative sliding relative to the first snake bone component 311, then b1 = b2. The angle of rotation of the first snake bone component 311 around the first rotation axis P1 is equal to the angle of rotation of the second snake bone component 312 around the second rotation axis P2. The snake bone joint 310 can achieve symmetrical rotation, and the movement accuracy of the snake bone joint 310 is high.

[0062] Furthermore, in the prior art, patent CN106061425B discloses that when the first snake bone component 311 rotates around the first rotation axis P1 and the second snake bone component 312 rotates around the second rotation axis P2, the pin on the first snake bone component 311 engages with the cycloidal concave tooth on the second snake bone component 312; however, when the first snake bone component 311 rotates around the first rotation axis P1 at a large angle and the second snake bone component 312 rotates around the second rotation axis P2 at a large angle, the aforementioned pin will disengage from the cycloidal concave tooth, and the transmission accuracy of the snake bone joint 310 will be greatly reduced. To improve transmission accuracy, existing technology designs multiple small pins on the first serpentine component 311 and multiple small cycloidal teeth on the second serpentine component 312. When the first serpentine component 311 rotates around the first rotation axis P1 and the second serpentine component 312 rotates around the second rotation axis P2, the first pin engages with the first cycloidal tooth, then the second pin engages with the second cycloidal tooth, and so on, thereby improving the transmission accuracy of the serpentine joint 310. However, in this method, the size of each pin and cycloidal tooth is relatively small, resulting in a decreased load-bearing capacity of the serpentine joint 310.

[0063] In this embodiment, when the first snake-bone component 311 rotates around the first rotation axis P1 and the second snake-bone component 312 rotates around the second rotation axis P2, the first side surface 31121 and the third side surface 31221 are always in contact with the first contact point, and the second side surface 31122 and the fourth side surface 31222 are always in contact with the second contact point. It can be seen that when the first snake-bone component 311 rotates around the first rotation axis P1 and the second snake-bone component 312 rotates around the second rotation axis P2, the first limiting part 3112 and the second limiting part 3122 are always engaged through the first contact point and the second contact point. Even if the first snake-bone component 311 rotates around the first rotation axis P1 at a large angle and the second snake-bone component 312 rotates around the second rotation axis P2 at a large angle, the first limiting part 3112 and the second limiting part 3122 are always engaged through the first contact point and the second contact point, and the engagement will not be disengaged. The transmission accuracy of the snake-bone joint 310 is high. Furthermore, the first limiting part 3112 and the second limiting part 3122 are also relatively large, which improves the load-bearing capacity of the snake joint 310.

[0064] Furthermore, such as Figure 2As shown, in this embodiment, the snake-bone joint 310 is further provided with a first driving member 315 and a second driving member 316. The first driving member 315 and the second driving member 316 are symmetrically distributed on both sides of the first plane 313. One end of the first driving member 315 and the second driving member 316 is fixed to the distal end of the flexible arm 30, and the other end of the first driving member 315 and the second driving member 316 passes through the flexible arm 30 and the straight tube 20 and is connected to the driving unit in the instrument box 10. Multiple first driving members 315 and the second driving member 316 can be provided, and the number of first driving members 315 and the second driving member 316 is equal. When the drive unit rotates in one direction, the first drive member 315 shortens within the snake-bone joint 310, and the second drive member 316 extends within the snake-bone joint 310. The first snake-bone member 311 rotates clockwise around the first rotation axis P1 from position P3 to position P4, and the second snake-bone member 312 rotates counterclockwise around the second rotation axis P2 from position P5 to position P6. The snake-bone joint 310 bends in the direction D1. When multiple snake-bone joints 310 within the flexible arm 30 bend in the direction D1, the flexible arm 30 achieves bending in the direction D1. When the drive unit rotates in another direction, the first drive member 315 extends within the snake joint 310, the second drive member 316 shortens within the snake joint 310, the first snake member 311 rotates counterclockwise around the first rotation axis P1 from position P3 to a certain position, the second snake member 312 rotates clockwise around the second rotation axis P2 from position P5 to a certain position, and the snake joint 310 bends in the direction D2. When multiple snake joints 310 within the flexible arm 30 bend in the direction D2, the flexible arm 30 achieves bending in the direction D2. It can be seen that when a certain serpentine joint 310 bends, one of the first driving member 315 and the second driving member 316 shortens within the serpentine joint 310, while the other driving member extends within the serpentine joint 310. Since the first serpentine member 311 within the serpentine joint 310 can perform pure rolling motion without relative sliding relative to the second serpentine member 312, and the second serpentine member 312 can perform pure rolling motion without relative sliding relative to the first serpentine member 311, the lever arms of the first driving member 315 and the second driving member 316 are always equal when the serpentine joint 310 bends. Specifically, the lever arm of the first driving member 315 is the distance from the first driving member 315 to the perpendicular bisector P1P2, and the lever arm of the second driving member 316 is the distance from the second driving member 316 to the perpendicular bisector. When the lever arms of the first driving member 315 and the second driving member 316 are always equal, the shortening and elongation of the driving members within the serpentine joint 310 remain equal.

[0065] Of course, this is understandable. Figure 3 and Figure 4As shown, the first limiting part 3112 is a groove, and the first limiting part 3112 also has a first arc surface 31123 connecting the first side surface 31121 and the second side surface 31122; the second limiting part 3122 is a protrusion, and the second limiting part 3122 also has a target plane 31223 connecting the third side surface 31221 and the fourth side surface 31222.

[0066] Of course, this is understandable. Figure 8 As shown, the outline of the first side surface 31121 can be a straight line parallel to the first plane 313; or, as shown... Figure 9 As shown, the outline of the first side 31121 can be a straight line that is not parallel to the first plane 313; the outline of the first side 31121 can also be a parabola, hyperbola, elliptic curve, Archimedean spiral, cubic curve, involute, exponential function curve, logarithmic function curve, polynomial function curve, power function curve, circular arc, trigonometric function curve or inverse trigonometric function curve; the outline of the third side 31221 is the conjugate curve of the outline of the first side 31121.

[0067] Of course, this is understandable. Figure 10 As shown, the outline of the third side 31221 can be a straight line parallel to the first plane 313; or, as shown... Figure 11 As shown, the outline of the third side 31221 can be a straight line that is not parallel to the first plane 313; the outline of the third side 31221 can also be a parabola, hyperbola, elliptic curve, Archimedean spiral, cubic curve, involute, exponential function curve, logarithmic function curve, polynomial function curve, power function curve, circular arc, trigonometric function curve or inverse trigonometric function curve; the outline of the first side 31121 is the conjugate curve of the outline of the third side 31221.

[0068] It is understandable that the outline of the second side 31122 can be a straight line parallel to the first plane 313, a straight line not parallel to the first plane 313, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve; the outline of the fourth side 31222 is the conjugate curve of the outline of the second side 31122.

[0069] It is understandable that the outline of the fourth side 31222 is a straight line parallel to the first plane 313, a straight line not parallel to the first plane 313, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve; the outline of the second side 31122 is the conjugate curve of the outline of the fourth side 31222.

[0070] The supporting structure will be explained below:

[0071] In one embodiment, such as Figure 12 As shown, the support structure includes a first unit 3113 disposed on a first surface 3111 and a second unit 3123 disposed on a second surface 3121. The first unit 3113 is provided with a first arcuate surface 31131, and the second unit 3123 is provided with a second arcuate surface 31231. The first arcuate surface 31131 and the second arcuate surface 31231 satisfy the following characteristics:

[0072] (1) The radii of the first circular arc surface 31131 and the second circular arc surface 31231 are equal;

[0073] (2) Regardless of whether the first snake bone component 311 rotates relative to the first rotation axis P1 or the second snake bone component 312 rotates relative to the second rotation axis P2, the first arc surface 31131 and the second arc surface 31231 are in top contact with each other.

[0074] (3) The axis of the first arc surface 31131 coincides with the first rotation axis P1, and the axis of the second arc surface 31231 coincides with the second rotation axis P2.

[0075] Under the constraints of the above features, regardless of whether the first serpentine member 311 rotates relative to the first rotation axis P1 or whether the second serpentine member 312 rotates relative to the second rotation axis P2, the distance between the first rotation axis P1 and the second rotation axis P2 is always the sum of the radii of the first arc surface 31131 and the second arc surface 31231. It can be seen that the above-mentioned support structure can constrain the distance between the first rotation axis P1 and the second rotation axis P2 to remain constant.

[0076] In another embodiment, such as Figure 13As shown, the support structure includes a first connector 317, which includes a first rotating pin 3171, a second rotating pin 3173, and a first connecting portion 3172 connecting the first rotating pin 3171 and the second rotating pin 3173. A first protrusion 3114 is provided on the first surface 3111 of the first serpentine member 311, and a first through hole 31141 is provided on the first protrusion 31141. A second protrusion 3124 is provided on the second surface 3121 of the second serpentine member 312, and a second through hole is provided on the second protrusion 3124. 31241, when the first rotating pin 3171 passes through the first through hole 31141 and the second rotating pin 3173 passes through the second through hole 31241, the axis of the first rotating pin 3171 coincides with the first rotating shaft P1; the axis of the second rotating pin 3173 coincides with the second rotating shaft P2. At this time, the distance between the first rotating shaft P1 and the second rotating shaft P2 is always equal to the length of the first connecting part 3172. It can be seen that the above-mentioned support structure can constrain the distance between the first rotating shaft P1 and the second rotating shaft P2 to remain unchanged. The first connecting part 3172 is provided with a first target surface 31721, the first protrusion 3114 is provided with a second target surface close to the first connector 317, and the second protrusion 3124 is provided with a third target surface close to the first connector 317. When the first rotating pin 3171 passes through the first through hole 31141 and the second rotating pin 3173 passes through the second through hole 31241, the first target surface 31721 abuts against the second target surface and the third target surface.

[0077] Example 2:

[0078] In this embodiment, in the snake-bone joint 310, two first limiting portions 3112 are provided at intervals on the first surface 3111 of the first snake-bone member 311 along the extension direction of the first rotation axis P1, and two second limiting portions 3122 are provided at intervals on the second surface 3121 of the second snake-bone member 312 along the extension direction of the second rotation axis P2; the first limiting portions 3112 and the second limiting portions 3122 are matched one-to-one. Figure 14 As shown, both first limiting portions 3112 can be grooves, such as... Figure 15 As shown, both second limiting portions 3122 can be protruding. In this case, each first limiting portion 3112 and one second limiting portion 3122 are in a concave-convex fit, and the fit method is the same as in Embodiment 1 above, which will not be repeated here. Figure 16 As shown, one of the two first limiting portions 3112 can be a protrusion, and the other can be a groove; one of the two second limiting portions 3122 is a protrusion, and the other can be a groove. In this case, each protrusion is matched with a groove, and the matching method is the same as in Embodiment 1 above, which will not be repeated here.

[0079] The support structure in this embodiment will be explained below:

[0080] In one embodiment, such as Figure 14 and Figure 15 As shown, the support structure includes a first unit 3113 and a third unit 3115 spaced apart on a first surface 3111 along the extension direction of a first rotation axis P1, and a second unit 3123 and a fourth unit 3125 spaced apart on a second surface 3121 along the extension direction of a second rotation axis P2. The first unit 3113 has a first arcuate surface 31131, and the second unit 3123 has a second arcuate surface 31231; the third unit 3115 has a third arcuate surface 31151, and the fourth unit 3125 has a fourth arcuate surface 31251. The first arcuate surface 31131 and the second arcuate surface 31231 satisfy the following characteristics:

[0081] (1) The radii of the first circular arc surface 31131 and the second circular arc surface 31231 are equal;

[0082] (2) Regardless of whether the first snake bone component 311 rotates relative to the first rotation axis P1 or the second snake bone component 312 rotates relative to the second rotation axis P2, the first arc surface 31131 and the second arc surface 31231 are in top contact with each other.

[0083] (3) The axis of the first arc surface 31131 coincides with the first rotation axis P1, and the axis of the second arc surface 31231 coincides with the second rotation axis P2.

[0084] The third circular arc surface 31151 and the fourth circular arc surface 31251 satisfy the following characteristics:

[0085] (1) The radii of the third arc surface 31151 and the fourth arc surface 31251 are equal, and the radii of the third arc surface 31151 and the fourth arc surface 31251 are equal to the radii of the first arc surface 31131 and the second arc surface 31231.

[0086] (2) Regardless of whether the first snake bone component 311 rotates relative to the first rotation axis P1 or the second snake bone component 312 rotates relative to the second rotation axis P2, the third arc surface 31151 and the fourth arc surface 31251 are in top contact.

[0087] (3) The axis of the third arc surface 31151 coincides with the first rotation axis P1, and the axis of the fourth arc surface 31251 coincides with the second rotation axis P2.

[0088] Under the constraints of the above features, regardless of whether the first serpentine member 311 rotates relative to the first rotation axis P1, or whether the second serpentine member 312 rotates relative to the second rotation axis P2, the distance between the first rotation axis P1 and the second rotation axis P2 is always the sum of the radii of the first arc surface 31131 and the second arc surface 31231, and simultaneously, the distance between the first rotation axis P1 and the second rotation axis P2 is always the sum of the radii of the third arc surface 31151 and the fourth arc surface 31251. Therefore, it can be seen that the above-mentioned support structure can constrain the distance between the first rotation axis P1 and the second rotation axis P2 to remain constant.

[0089] like Figure 16 and Figure 17As shown, the support structure includes a first connector 317 and a second connector 318 spaced apart along the first rotation axis P1; a first protrusion 3114 and a third protrusion 3116 spaced apart along the first rotation axis P1 on the first serpentine member 311, the first protrusion 3114 having a first through hole 31141 and the third protrusion 3116 having a third through hole; a second protrusion 3124 and a fourth protrusion 3126 spaced apart along the second rotation axis P2 on the second serpentine member 312, the second protrusion 3124 having a second through hole 31241 and the fourth protrusion 3126 having a fourth through hole 31261; the first connector 317 includes a first rotating pin 3171, a second rotating pin 3173, and a connector connecting the first rotating pin 3171 and the second rotating pin 318. The first connecting portion 3172 between 73; when the first rotating pin 3171 passes through the first through hole 31141 and the second rotating pin 3173 passes through the second through hole 31241, the axis of the first rotating pin 3171 coincides with the first rotating shaft P1, and the axis of the second rotating pin 3173 coincides with the second rotating shaft P2; the second connecting member 318 includes a third rotating pin 3181, a fourth rotating pin 3183 and a second connecting portion 3182 connecting the third rotating pin 3181 and the fourth rotating pin 3183; when the third rotating pin 3181 passes through the third through hole and the fourth rotating pin 3183 passes through the fourth through hole 31261, the axis of the third rotating pin 3181 coincides with the first rotating shaft P1, and the axis of the fourth rotating pin 3183 coincides with the second rotating shaft P2. At this time, the distance between the first rotating shaft P1 and the second rotating shaft P2 is always equal to the length of the first connecting part 3172 and the second connecting part 3182; thus, it can be seen that the above-mentioned support structure can constrain the distance between the first rotating shaft P1 and the second rotating shaft P2 to remain unchanged. Specifically, the first connecting part 3172 is provided with a first target surface 31721, the first protrusion 3114 is provided with a second target surface close to the first connecting member 317, and the second protrusion 3124 is provided with a third target surface close to the first connecting member 317. When the first rotating pin 3171 passes through the first through hole 31141 and the second rotating pin 3173 passes through the second through hole 31241, the first target surface 31721 abuts against the second target surface and the third target surface. The second connecting part 3182 is provided with a fourth target surface 31821, the third protrusion 3116 is provided with a fifth target surface near the second connecting member 318, and the fourth protrusion 3126 is provided with a sixth target surface near the second connecting member 318. When the third rotating pin 3181 passes through the third through hole and the fourth rotating pin 3183 passes through the fourth through hole 31261, the fourth target surface 31821 abuts against the fifth target surface and the fourth target surface 31821 abuts against the sixth target surface.

[0090] The support structure also includes a limiting member 319, which is located between the first connecting member 317 and the second connecting member 318, and is used to limit the first connecting member 317 and the second connecting member 318. Specifically, the first connecting portion 3172 is provided with a seventh target surface opposite to the first target surface 31721, and the seventh target surface is provided with a first mounting groove 3174; the second connecting portion 3182 is provided with an eighth target surface opposite to the fourth target surface 31821, and the eighth target surface is provided with a second mounting groove 3184. The limiting member 319 is engaged in the first mounting groove 3174 and the second mounting groove 3184.

[0091] Example 3:

[0092] The multiple snake-bone joints 310 in the above embodiments can be sequentially connected to form a flexible arm 30, such as... Figure 18 As shown and Figure 19As shown, in this embodiment, the flexible arm 30 includes a first snake-bone joint 31, a third snake-bone joint 33, a second snake-bone joint 32, and a fourth snake-bone joint 34 connected sequentially from the distal end to the proximal end. A straight tube section 35 connects the third snake-bone joint 33 and the second snake-bone joint 32. The two snake-bone components within the first snake-bone joint 31 can rotate around axes M1 and M2, the two snake-bone components within the third snake-bone joint 33 can rotate around axes M3 and M4, and the two snake-bone components within the second snake-bone joint 32 can rotate around axes M5 and M6. With axis M6 rotating, the two snake bone components within the fourth snake bone joint 34 can rotate around axes M7 and M8. The rotation axes within the first snake bone joint 31 and the second snake bone joint 32 are parallel and all located within the first plane 313, i.e., axes M1, M2, M5, and M6 are parallel and all located within the first plane 313; the rotation axes within the third snake bone joint 33 and the fourth snake bone joint 34 are parallel and all located within the second plane 314, i.e., axes M3, M4, M7, and M8 are parallel and all located within the second plane 314. The first plane 313 and the second plane 314 are orthogonal, and the intersection line is the axis L of the flexible arm 30. The flexible arm 30 also has a first drive rope 3151, a second drive rope 3152, a third drive rope 3153, and a fourth drive rope 3154. The first drive rope 3151 and the second drive rope 3152 are located on one side of the first plane 313, and the third drive rope 3153 and the fourth drive rope 3154 are located on the other side of the first plane 313. The first drive rope 3151, the second drive rope 3152, the third drive rope 3153, and the fourth drive rope 3154 are symmetrical about the first plane 313. The second drive rope 3152 and the third drive rope 3153 are located on one side of the second plane 314, and the first drive rope 3151 and the fourth drive rope 3154 are located on the other side of the second plane 314. The first drive rope 3151, the second drive rope 3152, the third drive rope 3153, and the fourth drive rope 3154 are symmetrical about the second plane 314. When the lengths of the first drive rope 3151 and the second drive rope 3152 change synchronously, and the lengths of the third drive rope 3153 and the fourth drive rope 3154 change synchronously, the first snake joint 31 and the second snake joint 32 rotate, and the flexible arm 30 bends in the left and right directions; when the lengths of the second drive rope 3152 and the third drive rope 3153 change synchronously, and the lengths of the first drive rope 3151 and the fourth drive rope 3154 change synchronously, the third snake joint 33 and the fourth snake joint 34 rotate, and the flexible arm 30 bends in the front and back directions.

[0093] When the flexible arm 30 is bent in the manner described above, the snake bone component inside the flexible arm 30 is prone to lateral movement and S-shaped deformation. The occurrence of S-shaped deformation will cause the flexible arm 30 to bend in an unstable posture when bending in the corresponding direction, which will eventually lead to the flexible arm 30 being unable to move the tool head to the designated position, seriously affecting the smooth progress of the surgical operation. To address the aforementioned issues, this application provides a first constraint member 3155 and a second constraint member 3156 within the flexible arm 30. The distal ends of the first constraint member 3155 and the second constraint member 3156 are fixed to the distal end of the flexible arm 30, i.e., fixed to the first snake bone member 311 within the first snake bone joint 31. The proximal ends of the first constraint member 3155 and the second constraint member 3156 are fixed to the proximal end of the flexible arm 30, i.e., fixed to the second snake bone member 312 within the fourth snake bone joint 34. The first constraint member 3155 and the second constraint member 3156 are inserted into the first snake bone joint 31 and the third snake bone joint 33 along a direction parallel to the first plane 313. After spiraling 180° through the first plane 313 at the straight tube section 35, they are inserted into the second snake bone joint 32 and the fourth snake bone joint 34 along a direction parallel to the first plane 313. The first constraint member 3155 spirally extends 180° at the straight pipe section 35. This means that when the first constraint member 3155 is inserted at position A1 and exited at position A2 at the straight pipe section 35, A1 and A2 are symmetrical about the first plane 313 on both sides of the first plane 313. When A1 and A2 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A1, A2 and the projection A of the axis L of the flexible arm 30 onto the aforementioned plane can form a central angle of 180°. Similarly, the 180° spiral extension of the second constraint member 3156 at the straight pipe section 35 refers to the second constraint member 3156 being inserted at position A3 and exiting at position A4 at the straight pipe section 35. A3 and A4 are symmetrical about the first plane 313 on both sides of the first plane 313. When A3 and A4 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A3, A4 and the projection A of the axis L of the flexible arm 30 onto the aforementioned plane can form a central angle of 180°.

[0094] Furthermore, in this embodiment, the flexible arm 30 includes four serpentine joints 310, each serpentine joint 310 including two serpentine components. The connection positions of the first constraint member 3155 and the second constraint member 3156 on each serpentine component are symmetrical based on the first plane 313; the connection positions refer to the positions of the connection holes. When the first constraint member 3155 and the second constraint member 3156 are inserted in the manner described above, such as Figure 20As shown, when the first constraint member 3155 and the second constraint member 3156 are projected onto the second plane 314, a first projection can be obtained. In the first projection, the first constraint member 3155 and the second constraint member 3156 are arranged crosswise at the straight pipe section 35. In the first projection, the first constraint member 3155 and the second constraint member 3156 are arranged parallel to the first plane 313 within the first snake joint 31, the third snake joint 33, the second snake joint 32, and the fourth snake joint 34. When the flexible arm 30 bends in the left and right directions, the third snake joint 33 and the fourth snake joint 34 do not rotate, so the lengths of the first constraint member 3155 and the second constraint member 3156 at the straight pipe section 35, at the third snake member, and at the fourth snake member remain unchanged. When the flexible arm 30 bends in the left and right directions, the first snake joint 31 and the second snake joint 32 rotate. Because the first constraint member 3155 and the second constraint member 3156 are arranged crosswise at the straight pipe section 35 in the first projection, the length change of the first constraint member 3155 in the first snake joint 31 is k1, and the length change of the first constraint member 3155 in the second snake joint 32 is k2. One of k1 and k2 is the elongation and the other is the shortening. The length change of the second constraint member 3156 in the first snake joint 31 is k3, and the length change of the second constraint member 3156 in the second snake joint 32 is k4. One of k3 and k4 is the elongation and the other is the shortening. Since the first snake joint 31 and the second snake joint 32 always maintain symmetrical rotation, k1 is always equal to k2, and k3 is always equal to k4. This makes the length of the first constraint member 3155 and the second constraint member 3156 always remain unchanged when the flexible arm 30 bends in the left and right directions.

[0095] When the flexible arm 30 bends in the left and right directions, if the snake bone components in the first snake bone joint 31 and the second snake bone joint 32 move laterally and produce an S-shaped deformation, the lengths of the first constraint member 3155 and the second constraint member 3156 will change. In this embodiment, when the flexible arm 30 bends, the lengths of the first constraint member 3155 and the second constraint member 3156 are kept unchanged, thereby constraining the S-shaped deformation produced by the first snake bone joint 31 and the second snake bone joint 32 when the flexible arm 30 bends.

[0096] Similarly, the flexible arm 30 in this application is also provided with a third constraint member 3157 and a fourth constraint member 3158. The distal ends of the third constraint member 3157 and the fourth constraint member 3158 are fixed to the distal end of the flexible arm 30, that is, fixed to the first snake bone member 311 in the first snake bone joint 31. The proximal ends of the first constraint member 3155 and the second constraint member 3156 are fixed to the proximal end of the flexible arm 30, that is, fixed to the second snake bone member 312 in the fourth snake bone joint 34. The third constraint member 3157 and the fourth constraint member 3158 are inserted into the first snake bone joint 31 and the third snake bone joint 33 in a direction parallel to the second plane 314. After spiraling 180° through the second plane 314 at the straight tube section 35, they are inserted into the second snake bone joint 32 and the fourth snake bone joint 34 in a direction parallel to the second plane 314. The phrase "the third constraint member 3157 extends spirally 180° at the straight pipe section 35" refers to the fact that when the insertion position of the third constraint member 3157 at the straight pipe section 35 is A5 and the exit position of the third constraint member 3157 at the straight pipe section 35 is A6, A5 and A6 are located on both sides of the second plane 314. When A5 and A6 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A5, A6 and the projection A of the axis L of the flexible arm 30 on the aforementioned plane can form a central angle of 180°. Similarly, the 180° spiral extension of the fourth constraint member 3158 at the straight pipe section 35 refers to the insertion position of the fourth constraint member 3158 at the straight pipe section 35 being A7 and the exit position of the fourth constraint member 3158 at the straight pipe section 35 being A8. When A7 and A8 are located on both sides of the second plane 314, when A7 and A8 are projected onto a plane perpendicular to the axis L of the flexible arm 30, A7, A8 and the projection A of the axis L of the flexible arm 30 on the aforementioned plane can form a central angle of 180°.

[0097] Furthermore, in this embodiment, the flexible arm 30 includes four serpentine joints 310, each serpentine joint 310 including two serpentine components. The connection positions of the third constraint member 3157 and the fourth constraint member 3158 on each serpentine component are symmetrical based on the second plane 314; the connection positions refer to the positions of the connection holes. When the third constraint member 3157 and the fourth constraint member 3158 are inserted in the manner described above, such as... Figure 21As shown, when the first constraint member 3155 and the second constraint member 3156 are projected onto the first plane 313, a second projection can be obtained. In the second projection, the third constraint member 3157 and the fourth constraint member 3158 are arranged in a cross configuration at the straight pipe section 35. In the second projection, the third constraint member 3157 and the fourth constraint member 3158 are arranged parallel to the second plane 314 and pass through the first snake joint 31, the third snake joint 33, the second snake joint 32, and the fourth snake joint 34. When the flexible arm 30 bends in the front-back direction, the first snake joint 31 and the second snake joint 32 do not rotate, so the lengths of the third constraint member 3157 and the fourth constraint member 3158 at the straight pipe section 35, the first snake member 311, and the second snake member 312 remain unchanged. When the flexible arm 30 bends in the front-back direction, the lengths of the third snake joint 33 and the fourth snake joint 34 remain unchanged. 4. Rotation: Since the third constraint member 3157 and the fourth constraint member 3158 are intersected at the straight pipe section 35 in the second projection, the length change of the third constraint member 3157 within the third snake joint 33 is k5, and the length change of the third constraint member 3157 within the fourth snake joint 34 is k6. One of k5 and k6 is the elongation and the other is the shortening. The length change of the fourth constraint member 3158 within the third snake joint 33 is k7, and the length change of the fourth constraint member 3158 within the fourth snake joint 34 is k8. One of k7 and k8 is the elongation and the other is the shortening. Since the third snake joint 33 and the fourth snake joint 34 always maintain symmetrical rotation, k5 is always equal to k6, and k7 is always equal to k8. This ensures that the lengths of the third constraint member 3157 and the fourth constraint member 3158 remain unchanged when the flexible arm 30 bends in the front-back direction.

[0098] When the flexible arm 30 bends in the front-back direction, if the snake bone components in the third snake bone joint 33 and the fourth snake bone joint 34 move laterally and produce an S-shaped deformation, the lengths of the third constraint member 3157 and the fourth constraint member 3158 will change. In this embodiment, when the flexible arm 30 bends, the lengths of the third constraint member 3157 and the fourth constraint member 3158 are kept unchanged, thereby constraining the S-shaped deformation produced by the third snake bone joint 33 and the fourth snake bone joint 34 when the flexible arm 30 bends.

[0099] 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 component and a second snake-bone component, the first snake-bone component rotating relative to a first rotation axis, the second snake-bone component rotating relative to a second rotation axis, the first rotation axis and the second rotation axis being parallel and both located within a first plane; the snake-bone joint further comprising a support structure connecting the first snake-bone component and the second snake-bone component; the first snake-bone component having a first surface, the first surface having a first limiting portion, the second snake-bone component having a second surface opposite to the first surface, the second surface having a second limiting portion cooperating with the first limiting portion, the first limiting portion and the second limiting portion having a concave-convex fit; characterized in that... The first limiting part has a first side surface located on one side of the first plane, the first limiting part has a second side surface located on the other side of the first plane, the second limiting part has a third side surface located on one side of the first plane and cooperating with the first side surface, and the second limiting part has a fourth side surface located on the other side of the first plane and cooperating with the second side surface; the contour line of the first side surface and the contour line of the third side surface are conjugate curves; the contour line of the second side surface and the contour line of the fourth side surface are conjugate curves.

2. The snake-bone joint according to claim 1, characterized in that, The first limiting part is a groove, and the first limiting part also has a first arc surface connecting the first side surface and the second side surface; The second limiting part is a protrusion, and the second limiting part also has a target plane connecting the third side and the fourth side.

3. The snake-bone joint according to claim 1, characterized in that, The outline of the first side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve. The outline of the third side is a conjugate curve of the outline of the first side.

4. The snake-bone joint according to claim 1, characterized in that, The outline of the third side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve. The outline of the first side is a conjugate curve of the outline of the third side.

5. The snake-bone joint according to claim 1, characterized in that, The outline of the second side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve. The outline of the fourth side is a conjugate curve of the outline of the second side.

6. The snake-bone joint according to claim 1, characterized in that, The outline of the fourth side is a straight line parallel to the first plane, a straight line not parallel to the first plane, a parabola, a hyperbola, an elliptic curve, an Archimedean spiral, a cubic curve, an involute, an exponential function curve, a logarithmic function curve, a polynomial function curve, a power function curve, a circular arc, a trigonometric function curve, or an inverse trigonometric function curve. The contour line of the second side is the conjugate curve of the contour line of the fourth side.

7. The snake-bone joint according to any one of claims 1-6, characterized in that, The support structure includes a first unit disposed on the first surface and a second unit disposed on the second surface. The first unit is provided with a first arc surface and the second unit is provided with a second arc surface. The first arc surface and the second arc surface are in contact with each other and have the same radius. The axis of the first arc surface coincides with the first rotation axis and the axis of the second arc surface coincides with the second rotation axis.

8. The snake-bone joint according to any one of claims 1-6, characterized in that, The support structure includes a first connector, which includes a first rotating pin, a second rotating pin, and a first connecting portion connecting the first rotating pin and the second rotating pin. The first serpentine component has a first through hole, and the second serpentine component has a second through hole. When the first rotating pin passes through the first through hole and the second rotating pin passes through the second through hole, the axis of the first rotating pin coincides with the first rotating axis; the axis of the second rotating pin coincides with the second rotating axis.

9. The snake-bone joint according to any one of claims 1-6, characterized in that, Two first limiting portions are provided at intervals along the first rotation axis on the first surface, and two second limiting portions are provided at intervals along the second rotation axis on the second surface; the first limiting portions and the second limiting portions are matched one-to-one.

10. The snake-bone joint according to claim 9, characterized in that, The support structure includes a first unit and a third unit spaced apart on the first surface along the extension direction of the first rotation axis, and a second unit and a fourth unit spaced apart on the second surface along the extension direction of the second rotation axis. The first unit has a first arcuate surface, and the second unit has a second arcuate surface. The first arcuate surface and the second arcuate surface are in contact with each other and have equal radii. The third unit has a third arcuate surface, and the fourth unit has a fourth arcuate surface. The third arcuate surface and the fourth arcuate surface are in contact with each other and have equal radii. The axes of the first arcuate surface and the third arcuate surface coincide with the first rotation axis, and the axes of the second arcuate surface and the fourth arcuate surface coincide with the second rotation axis.

11. The snake-bone joint according to claim 9, characterized in that, The support structure includes a first connector and a second connector that are spaced apart along the extension direction of the first rotation axis. The first connector includes a first rotating pin, a second rotating pin, and a first connecting portion connected between the first rotating pin and the second rotating pin; the first serpentine component has a first through hole, the second serpentine component has a second through hole, and when the first rotating pin passes through the first through hole and the second rotating pin passes through the second through hole, the axis of the first rotating pin coincides with the first rotating axis, and the axis of the second rotating pin coincides with the second rotating axis. The second connector includes a third rotating pin, a fourth rotating pin, and a second connecting portion connecting the third rotating pin and the fourth rotating pin; the first serpentine component has a third through hole, the second serpentine component has a fourth through hole, and when the third rotating pin passes through the third through hole and the fourth rotating pin passes through the fourth through hole, the axis of the third rotating pin coincides with the first rotating axis, and the axis of the fourth rotating pin coincides with the second rotating axis.

12. The snake-bone joint according to claim 11, characterized in that, The support structure also includes: A limiting member is located between the first connecting member and the second connecting member, and is used to limit the first connecting member and the second connecting member.

13. A flexible arm, characterized in that, The flexible arm includes a plurality of snake-bone joints as described in any one of claims 1-12, and the plurality of snake-bone joints are connected sequentially. The plurality of snake-bone joints include a first snake-bone joint and a second snake-bone joint with rotation axes parallel to each other and both located in the first plane. A first constraint member and a second constraint member are inserted through the first snake-bone joint and the second snake-bone joint. The distal ends of the first constraint member and the second constraint member are fixed to the distal end of the flexible arm, and the proximal ends of the first constraint member and the second constraint member are fixed to the proximal end of the flexible arm. The first constraint member and the second constraint member are inserted into the first snake-bone joint along a direction parallel to the first plane. After spiraling 180° at the connection between the first snake-bone joint and the second snake-bone joint, they are inserted into the second snake-bone joint along a direction parallel to the first plane. The connection positions of the first constraint member and the second constraint member on each of the snake-bone components are symmetrical based on the first plane.

14. The flexible arm according to claim 13, characterized in that, The first snake joint is connected to the second snake joint via a straight tube section, and the first and second constraint members extend spirally 180° at the straight tube section.

15. A mechanical lever, characterized in that, In addition to the flexible arm as described in claim 13, the instrument lever also includes an instrument box, a straight tube, an end tool, and a drive component. The instrument box, the straight tube, the flexible arm, and the end effector are connected in sequence. One end of the drive component is inserted inside the flexible arm, and the other end of the drive component passes through the straight tube and is connected to the instrument box.

16. A surgical robot, characterized in that, The surgical robot includes a plurality of instrument levers as described in claim 15.

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