Flexible arm

Abstract

The invention discloses a flexible arm. The flexible arm comprises a first snake bone assembly, a second snake bone assembly, a first restraining piece and a second restraining piece. The first snake bone assembly can rotate around a first rotating shaft and a second rotating shaft which are parallel to each other, the second snake bone assembly can rotate around a third rotating shaft and a fourth rotating shaft which are parallel to each other, the second rotating shaft is parallel to the third rotating shaft, and the first rotating shaft, the second rotating shaft, the third rotating shaft and the fourth rotating shaft are all located in a first plane; the second plane is orthogonal to the first plane, the flexible arm is provided with a first projection on the second plane, and the first restraining piece and the second restraining piece are symmetrical about the first plane in the first projection, penetrate through the first snake bone assembly and the second snake bone assembly in the direction parallel to the axis of the flexible arm and intersect between the first snake bone assembly and the second snake bone assembly. According to the flexible arm, S-shaped deformation generated by lateral movement of the snake bone assembly in the flexible arm when the flexible arm is bent can be effectively restrained.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a flexible arm. Background Art

[0002] With the development of science and technology, various surgical systems have been widely used. The surgical system usually includes a control end and a surgical robot. The surgical robot is provided with an instrument rod. The instrument rod usually includes an instrument box, a straight tube, a flexible arm and a terminal tool connected in sequence. A driving unit is provided in the instrument box, and a driving member connected to the driving unit is inserted into the flexible arm. During the operation, the terminal tool of the surgical robot and at least part of the flexible arm are inserted into the patient's body. Then the doctor operates the surgical robot through the control end to operate the driving unit of the instrument box. After the driving unit is operated, the driving member is retracted and released. After the driving member is retracted and released, the flexible arm bends in the corresponding direction. During the bending process of the flexible arm, the terminal tool will be driven to move. When the flexible arm is bent at a certain angle, the terminal tool will be driven to move to the specified position. After the terminal tool moves to the specified position, the patient can be operated by operating the terminal tool.

[0003] However, in practice, when the flexible arm bends, the components inside the flexible arm will move under the action of external loads to produce S-shaped deformation. The appearance of S-shaped deformation will cause the bending posture of the flexible arm to be unstable when bending in the corresponding direction, which will eventually lead to the inability of the flexible arm to drive the end tool to move to the specified position, resulting in poor control accuracy and affecting the smooth progress of the surgical operation. Therefore, how to solve the S-shaped deformation of the flexible arm under the action of external loads has become an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present application is to provide a flexible arm, which can effectively restrain the S-shaped deformation caused by the lateral movement of the snake bone component in the flexible arm when the flexible arm is bent.

[0005] The embodiment of the present application is implemented as follows:

[0006] The present application provides a flexible arm, which includes a first snake bone component, a second snake bone component, a first constraint and a second constraint; the first snake bone component can rotate around a first rotation axis and a second rotation axis that are parallel to each other, and the second snake bone component can rotate around a third rotation axis and a fourth rotation axis that are parallel to each other, the second rotation axis is parallel to the third rotation axis, and the first rotation axis, the second rotation axis, the third rotation axis and the fourth rotation axis are all located in a first plane; the distance between the first rotation axis and the second rotation axis is constant, and the distance between the third rotation axis and the fourth rotation axis is constant; the second plane is orthogonal to the first plane, and the flexible arm has a first projection on the second plane, in which the first constraint and the second constraint are symmetrical about the first plane, and are arranged in the first snake bone component and the second snake bone component along a direction parallel to the axis of the flexible arm, and cross between the first snake bone component and the second snake bone component.

[0007] In one embodiment, the flexible arm further includes a third snake bone component and a fourth snake bone component, the third snake bone component can rotate around a fifth rotation axis and a sixth rotation axis which are parallel to each other, the fourth snake bone component can rotate around a seventh rotation axis and an eighth rotation axis which are parallel to each other, the sixth rotation axis is parallel to the seventh rotation axis, and the fifth rotation axis, the sixth rotation axis, the seventh rotation axis and the eighth rotation axis are all located in the second plane; the distance between the fifth rotation axis and the sixth rotation axis is constant, and the distance between the seventh rotation axis and the eighth rotation axis is constant; the flexible arm includes a first snake bone element, a second snake bone element, a third snake bone element, a fourth snake bone element and a fifth snake bone element which are arranged in sequence, the first snake bone element and the second snake bone element constitute a first snake bone component, the second snake bone element and the third The serpentine elements constitute a third serpentine assembly, the third serpentine element and the fourth serpentine element constitute a second serpentine assembly, and the fourth serpentine element and the fifth serpentine element constitute a fourth serpentine assembly; in the first projection, the first constraint member and the second constraint member are arranged in the third serpentine assembly and the fourth serpentine assembly along a direction parallel to the axis of the flexible arm, and cross in the second serpentine element or the third serpentine element; the flexible arm has a second projection on the first plane, in the second projection, the first constraint member and the second constraint member are symmetrical about the second plane, in the second projection, the first constraint member and the second constraint member are arranged in the first serpentine assembly, the second serpentine assembly, the third serpentine assembly and the fourth serpentine assembly along a direction parallel to the axis of the flexible arm, and cross in the third serpentine element or the fourth serpentine element.

[0008] In one embodiment, the first snake bone element and the second snake bone element constitute a first snake bone component, the second snake bone element and the third snake bone element constitute a third snake bone component, the third snake bone element and the fourth snake bone element constitute a fourth snake bone component, and the fourth snake bone element and the fifth snake bone element constitute a second snake bone component; in the first projection, the first constraint and the second constraint cross in the second snake bone element or the fourth snake bone element; in the second projection, the first constraint and the second constraint cross in the third snake bone element.

[0009] In one embodiment, each snake bone element is provided with a first hole, a second hole, a third hole and a fourth hole, the first hole and the second hole are located on one side of the first plane, the third hole and the fourth hole are located on the other side of the first plane, the first hole and the third hole are symmetrical about the first plane, and the second hole and the fourth hole are symmetrical about the first plane; the first holes on all the snake bone elements are coaxially arranged, the second holes on all the snake bone elements are coaxially arranged, the third holes on all the snake bone elements are coaxially arranged, and the fourth holes on all the snake bone elements are coaxially arranged; the first constraint member sequentially passes through the first hole on the first snake bone element, the first hole and the third hole on the second snake bone element, the third hole on the third snake bone element, the third hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element; the second constraint member sequentially passes through the fourth hole on the first snake bone element, the fourth hole and the second hole on the second snake bone element, the second hole on the third snake bone element, the second hole and the first hole on the fourth snake bone element, the first hole on the fifth snake bone element hole; or, the first constraint member sequentially passes through the first hole on the first serpentine element, the first hole on the second serpentine element, the first hole and the third hole on the third serpentine element, the third hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; the second constraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole on the second serpentine element, the fourth hole and the second hole on the third serpentine element, the second hole and the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; or, the first constraint member sequentially passes through the first hole on the first serpentine element, the first hole and the third hole on the second serpentine element, the third hole and the fourth hole on the third serpentine element, the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; the second constraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole and the second hole on the second serpentine element, the second hole and the first hole on the third serpentine element, the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element.

[0010] In one embodiment, the first restraint member sequentially passes through the third hole on the first serpentine element, the third hole and the second hole on the second serpentine element, the second hole on the third serpentine element, the second hole and the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second restraint member sequentially passes through the second hole on the first serpentine element, the second hole and the third hole on the second serpentine element, the third hole on the third serpentine element, the third hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; or the first restraint member sequentially passes through the third hole on the first serpentine element, the third hole on the second serpentine element, the third hole and the second hole on the third serpentine element, the second hole and the first hole on the fourth serpentine element, and the the first hole; the second constraint member sequentially passes through the second hole on the first serpentine element, the second hole on the second serpentine element, the second hole and the third hole on the third serpentine element, the third hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; or, the first constraint member sequentially passes through the third hole on the first serpentine element, the third hole and the second hole on the second serpentine element, the second hole and the first hole on the third serpentine element, the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second constraint member sequentially passes through the second hole on the first serpentine element, the second hole and the third hole on the second serpentine element, the third hole and the fourth hole on the third serpentine element, the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element.

[0011] In one embodiment, the first constraint member sequentially passes through the first hole on the first serpentine element, the first hole and the fourth hole on the second serpentine element, the fourth hole on the third serpentine element, the fourth hole and the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second constraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole and the first hole on the second serpentine element, the first hole on the third serpentine element, the first hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; or the first constraint member sequentially passes through the first hole on the first serpentine element, the first hole on the second serpentine element, the first hole and the fourth hole on the third serpentine element, the fourth hole and the first hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element. the first hole; the second constraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole on the second serpentine element, the fourth hole and the first hole on the third serpentine element, the first hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; or, the first constraint member sequentially passes through the first hole on the first serpentine element, the first hole and the fourth hole on the second serpentine element, the fourth hole and the first hole on the third serpentine element, the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second constraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole and the first hole on the second serpentine element, the first hole and the fourth hole on the third serpentine element, the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element.

[0012] In one embodiment, each snake bone element is provided with a first hole, a second hole, a third hole and a fourth hole, the first hole and the second hole are located on one side of the first plane, the third hole and the fourth hole are located on the other side of the first plane, the first hole and the third hole are symmetrical about the first plane, and the second hole and the fourth hole are symmetrical about the first plane; the first holes on all the snake bone elements are coaxially arranged, the second holes on all the snake bone elements are coaxially arranged, the third holes on all the snake bone elements are coaxially arranged, and the fourth holes on all the snake bone elements are coaxially arranged; the first constraint member passes through the first hole on the first snake bone element, the first hole and the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole on the fourth snake bone element, the first hole on the fifth snake bone element, and the second hole on the fifth snake bone element in sequence. Four holes; the second constraint member passes through the fourth hole on the first snake bone element, the fourth hole and the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; or, the first constraint member passes through the third hole on the first snake bone element, the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole and the second hole on the fourth snake bone element, and the second hole on the fifth snake bone element in sequence; the second constraint member passes through the second hole on the first snake bone element, the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole and the third hole on the fourth snake bone element, and the third hole on the fifth snake bone element in sequence.

[0013] In one embodiment, the first restraint member sequentially passes through the third hole on the first serpentine element, the third hole and the second hole on the second serpentine element, the second hole and the first hole on the third serpentine element, the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second restraint member sequentially passes through the second hole on the first serpentine element, the second hole and the third hole on the second serpentine element, the third hole and the fourth hole on the third serpentine element, the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; or, the first restraint member sequentially passes through the third hole on the first serpentine element, the third hole on the second serpentine element, the third hole and the fourth hole on the third serpentine element, the fourth hole and the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second restraint member sequentially passes through the second hole on the first serpentine element, the second hole on the second serpentine element, the second hole and the first hole on the third serpentine element, the first hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element.

[0014] In one embodiment, the first restraint member sequentially passes through the first hole on the first serpentine element, the first hole on the second serpentine element, the first hole and the fourth hole on the third serpentine element, the fourth hole and the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second restraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole on the second serpentine element, the fourth hole and the first hole on the third serpentine element, the first hole and the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element; or, the first restraint member sequentially passes through the first hole on the first serpentine element, the first hole and the fourth hole on the second serpentine element, the fourth hole and the first hole on the third serpentine element, the first hole on the fourth serpentine element, and the first hole on the fifth serpentine element; the second restraint member sequentially passes through the fourth hole on the first serpentine element, the fourth hole and the first hole on the second serpentine element, the first hole and the fourth hole on the third serpentine element, the fourth hole on the fourth serpentine element, and the fourth hole on the fifth serpentine element.

[0015] In one embodiment, the flexible arm further includes a third snake bone component and a fourth snake bone component, the third snake bone component can rotate around a fifth rotation axis and a sixth rotation axis which are parallel to each other, the fourth snake bone component can rotate around a seventh rotation axis and an eighth rotation axis which are parallel to each other, the sixth rotation axis is parallel to the seventh rotation axis, and the fifth rotation axis, the sixth rotation axis, the seventh rotation axis and the eighth rotation axis are all located in the second plane; the distance between the fifth rotation axis and the sixth rotation axis is constant, and the distance between the seventh rotation axis and the eighth rotation axis is constant; the flexible arm includes a first snake bone element, a second snake bone element, a third snake bone element, a fourth snake bone element and a fifth snake bone element which are arranged in sequence, the first snake bone element and the second snake bone element constitute a first snake bone component, the second snake bone element and the third snake bone element constitute a third snake bone component The third serpentine bone component and the fourth serpentine bone component form a second serpentine bone component, and the fourth serpentine bone component and the fifth serpentine bone component form a fourth serpentine bone component; in the first projection, the first constraint member and the second constraint member are arranged in the third serpentine bone component and the fourth serpentine bone component in a direction parallel to the axis of the flexible arm, and cross in the second serpentine bone component or the third serpentine bone component; the flexible arm also includes a third constraint member and a fourth constraint member, the flexible arm has a second projection on the first plane, in the second projection, the third constraint member and the fourth constraint member are symmetrical about the second plane, in the second projection, the third constraint member and the fourth constraint member are arranged in the first serpentine bone component, the second serpentine bone component, the third serpentine bone component and the fourth serpentine bone component in a direction parallel to the axis of the flexible arm, and cross in the third serpentine bone component or the fourth serpentine bone component.

[0016] In one embodiment, the first snake bone element and the second snake bone element constitute a first snake bone component, the second snake bone element and the third snake bone element constitute a third snake bone component, the third snake bone element and the fourth snake bone element constitute a fourth snake bone component, and the fourth snake bone element and the fifth snake bone element constitute a second snake bone component; in the first projection, the first constraint and the second constraint cross in the second snake bone element or the fourth snake bone element; in the second projection, the third constraint and the fourth constraint cross in the third snake bone element.

[0017] In one embodiment, each snake bone element is provided with a fifth hole, a sixth hole, a seventh hole and an eighth hole, the fifth hole and the sixth hole are located on the first plane and are symmetrically distributed about the axis of the flexible arm, the seventh hole and the eighth hole are located on the second plane and are symmetrically distributed about the axis of the flexible arm; the fifth holes on all the snake bone elements are coaxially arranged, the sixth holes on all the snake bone elements are coaxially arranged, the seventh holes on all the snake bone elements are coaxially arranged, and the eighth holes on all the snake bone elements are coaxially arranged; the first constraint member sequentially passes through the eighth hole of the first snake bone element, the eighth hole and the seventh hole on the second snake bone element, the seventh hole of the third snake bone element, the seventh hole of the fourth snake bone element and the seventh hole of the fifth snake bone element; the second constraint member sequentially passes through the first snake bone element The third constraint member passes through the fifth hole of the first serpentine bone element, the fifth hole on the second serpentine bone element, the fifth hole and the sixth hole on the third serpentine bone element, the sixth hole on the fourth serpentine bone element and the sixth hole on the fifth serpentine bone element in sequence; the fourth constraint member passes through the sixth hole on the first serpentine bone element, the sixth hole on the second serpentine bone element, the sixth hole and the fifth hole on the third serpentine bone element, the fifth hole on the fourth serpentine bone element and the fifth hole on the fifth serpentine bone element in sequence; or the first constraint member passes through the eighth hole of the first serpentine bone element, the fifth hole on the second serpentine bone element, the fifth hole and the fifth hole on the third serpentine bone element, the fifth hole on the fourth serpentine bone element and the fifth hole on the fifth serpentine bone element in sequence. The second constraint member passes through the seventh hole on the first serpentine element, the seventh hole on the second serpentine element, the seventh hole and the eighth hole on the third serpentine element, the eighth hole on the fourth serpentine element and the eighth hole on the fifth serpentine element in sequence; the third constraint member passes through the fifth hole on the first serpentine element, the fifth hole on the second serpentine element, the fifth hole on the third serpentine element, the fifth hole and the sixth hole on the fourth serpentine element in sequence; the fourth constraint member passes through the sixth hole on the first serpentine element, the sixth hole on the second serpentine element, the sixth hole on the third serpentine element, the eighth hole on the fourth serpentine element in sequence The sixth hole and the fifth hole of the first serpentine element, and the fifth hole of the fifth serpentine element; or, the first constraint member sequentially passes through the eighth hole of the first serpentine element, the eighth hole and the seventh hole of the second serpentine element, the seventh hole of the third serpentine element, the seventh hole of the fourth serpentine element, and the seventh hole of the fifth serpentine element; the second constraint member sequentially passes through the seventh hole of the first serpentine element, the seventh hole and the eighth hole of the second serpentine element, the eighth hole of the third serpentine element, the eighth hole of the fourth serpentine element, and the eighth hole of the fifth serpentine element; the third constraint member sequentially passes through the fifth hole of the first serpentine element, the fifth hole of the second serpentine element, the fifth hole of the third serpentine element, the fifth hole and the sixth hole of the fourth serpentine element, and the sixth hole of the fifth serpentine element;The fourth restraining member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole on the third snake bone element, the sixth hole and the fifth hole on the fourth snake bone element, and the fifth hole on the fifth snake bone element in sequence. ;

[0018] In one embodiment, each snake bone element is provided with a fifth hole, a sixth hole, a seventh hole and an eighth hole, the fifth hole and the sixth hole are located on the first plane and are symmetrically distributed about the axis of the flexible arm, the seventh hole and the eighth hole are located on the second plane and are symmetrically distributed about the axis of the flexible arm; the fifth holes on all the snake bone elements are coaxially arranged, the sixth holes on all the snake bone elements are coaxially arranged, the seventh holes on all the snake bone elements are coaxially arranged, and the eighth holes on all the snake bone elements are coaxially arranged; the first constraint member passes through the eighth hole of the first snake bone element, the eighth hole of the second snake bone element, and the eighth hole of the second snake bone element in sequence. The second constraint member passes through the seventh hole on the first serpentine element, the seventh hole and the eighth hole on the second serpentine element, the eighth hole on the third serpentine element, the eighth hole on the fourth serpentine element and the eighth hole on the fifth serpentine element in sequence; the third constraint member passes through the fifth hole on the first serpentine element, the fifth hole on the second serpentine element, the fifth hole and the sixth hole on the third serpentine element, the sixth hole on the fourth serpentine element and the eighth hole on the fifth serpentine element in sequence six holes; the fourth constraint member sequentially passes through the sixth hole on the first serpentine element, the sixth hole on the second serpentine element, the sixth hole and the fifth hole on the third serpentine element, the fifth hole on the fourth serpentine element, and the fifth hole on the fifth serpentine element; or the first constraint member sequentially passes through the eighth hole on the first serpentine element, the eighth hole on the second serpentine element, the eighth hole on the third serpentine element, the eighth hole and the seventh hole on the fourth serpentine element, and the seventh hole on the fifth serpentine element; the second constraint member sequentially passes through the seventh hole on the first serpentine element, the seventh hole on the second serpentine element, the fifth hole on the fourth serpentine element, and the seventh hole on the fifth serpentine element. The seventh hole on the third snake bone element, the seventh hole and the eighth hole on the fourth snake bone element, and the eighth hole on the fifth snake bone element; the third constraint member passes through the fifth hole on the first snake bone element, the fifth hole on the second snake bone element, the fifth hole and the sixth hole on the third snake bone element, the sixth hole on the fourth snake bone element, and the sixth hole on the fifth snake bone element in sequence; the fourth constraint member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole and the fifth hole on the third snake bone element, the fifth hole on the fourth snake bone element, and the fifth hole on the fifth snake bone element in sequence.

[0019] In one embodiment, in the first projection, the first constraint member and the second constraint member are arranged in the first snake bone component, the second snake bone component and the fourth snake bone component along a direction parallel to the axis of the flexible arm, and cross in the third snake bone component; in the second projection, the third constraint member and the fourth constraint member are arranged in the first snake bone component, the third snake bone component and the fourth snake bone component along a direction parallel to the axis of the flexible arm, and cross in the second snake bone component.

[0020] In one embodiment, each snake bone element is provided with a fifth hole, a sixth hole, a seventh hole and an eighth hole, the fifth hole and the sixth hole are located on the first plane and are symmetrically distributed about the axis of the flexible arm, the seventh hole and the eighth hole are located on the second plane and are symmetrically distributed about the axis of the flexible arm; the fifth holes on all the snake bone elements are coaxially arranged, the sixth holes on all the snake bone elements are coaxially arranged, the seventh holes on all the snake bone elements are coaxially arranged, and the eighth holes on all the snake bone elements are coaxially arranged; the first constraint member passes through the eighth hole on the first snake bone element, the eighth hole on the second snake bone element, the seventh hole on the third snake bone element, the seventh hole on the fourth snake bone element and the fifth snake bone element in sequence. The seventh hole on the element; the second constraint member passes through the seventh hole on the first snake bone element, the seventh hole on the second snake bone element, the eighth hole on the third snake bone element, the eighth hole on the fourth snake bone element and the eighth hole on the fifth snake bone element in sequence; the third constraint member passes through the fifth hole on the first snake bone element, the fifth hole on the second snake bone element, the fifth hole on the third snake bone element, the sixth hole on the fourth snake bone element and the sixth hole on the fifth snake bone element in sequence; the fourth constraint member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole on the third snake bone element, the fifth hole on the fourth snake bone element and the fifth hole on the fifth snake bone element in sequence.

[0021] The beneficial effects of this application compared with the prior art are:

[0022] The flexible arm of the present application includes multiple snake-bone components and multiple constraints inserted into the multiple snake-bone components. The multiple constraints can effectively constrain the S-shaped deformation caused by the lateral movement of the snake-bone components in the flexible arm when the flexible arm is bent, so that the flexible arm can bend in a fixed bending posture to drive the end tool to the specified position, thereby ensuring the smooth progress of the surgical operation and improving the control accuracy of the flexible arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic diagram of the structure of the instrument rod shown in this application;

[0025] Figure 2 The flexible arm shown in this application is schematically shown Figure 1 ;

[0026] Figure 3 The flexible arm shown in this application is schematically shown Figure 2 ;

[0027] Figure 4 The flexible arm shown in this application is schematically shown Figure 3 ;

[0028] Figure 5 The first projection diagram shown in this application Figure 1 ;

[0029] Figure 6 The second projection diagram shown in this application Figure 1 ;

[0030] Figure 7 This is a schematic diagram of the distribution of the first hole, the second hole, the third hole and the fourth hole shown in this application;

[0031] Figure 8 Schematic diagram of the installation of the restraint member shown in this application Figure 1 ;

[0032] Fig. 9 Schematic diagram of the installation of the restraint member shown in this application Figure 2 ;

[0033] Fig.10 Schematic diagram of the installation of the restraint member shown in this application Figure 3 ;

[0034] Fig.11 Schematic diagram of the installation of the restraint member shown in this application Figure 4 ;

[0035] Fig.12 The flexible arm shown in this application is schematically shown Figure 4 ;

[0036] Fig.13 The first projection diagram shown in this application Figure 2 ;

[0037] Fig.14 The second projection diagram shown in this application Figure 2 ;

[0038] Fig.15 Schematic diagram of the installation of the restraint member shown in this application Figure 5 ;

[0039] Fig.16 The first projection diagram shown in this application Figure 3 ;

[0040] Fig.17 The second projection diagram shown in this application Figure 3 ;

[0041] Fig.18 This is a schematic diagram of the distribution of the fifth hole, the sixth hole, the seventh hole and the eighth hole shown in this application;

[0042] Fig.19 Schematic diagram of the installation of the restraint member shown in this application Figure 6 ;

[0043] Fig. 20 The first projection diagram shown in this application Figure 4 ;

[0044] Fig.21 The second projection diagram shown in this application Figure 4 ;

[0045] Fig. 22 The first projection diagram shown in this application Figure 5 ;

[0046] Fig.23 The second projection diagram shown in this application Figure 5 ;

[0047] Fig.24 Schematic diagram of the installation of the restraint member shown in this application Figure 7 ;

[0048] Fig.25 This is a schematic diagram of the symmetrical rotation of the snake bone assembly shown in this application.

[0049] Reference numerals:

[0050] 1-instrument rod; 10-instrument box; 20-straight tube; 30-flexible arm; 31-first snake bone component; 32-second snake bone component; 34-first plane; 35-second plane; 36-third snake bone component; 37-fourth snake bone component; 40-end tool; 50-target snake bone component; 51-first target snake bone element; 52-second target snake bone element; 301-first snake bone element; 302-second snake bone element; 303-third snake bone element; 304-fourth snake bone element; 305-fifth snake bone element; 306-first hole; 307-second hole; 308-third hole; 309-fourth hole; 311-first rotation axis; 312-second rotation axis; 321-third rotation axis; 322-fourth rotation axis; 331-first restraining member; 332-second restraining member; 333-third restraining member; 334-fourth restraining member; 361-fifth rotation axis; 362-sixth rotation axis; 371-seventh rotation axis; 372-eighth rotation axis; 381-fifth hole; 382-sixth hole; 383-eighth hole; 384-seventh hole; 391-first disk; 392-second disk; 393-third disk; 394-fourth disk; 395-connecting member; 511-ninth rotation axis; 521-tenth rotation axis. DETAILED DESCRIPTION

[0051] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and do not indicate the order of arrangement, nor can they be understood as indicating or implying relative importance.

[0052] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0053] In the description of the present application, it should be noted that the terms "inside", "outside", "left", "right", "up", "down", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the products of the present application are usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0054] In the description of this application, unless otherwise clearly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0055] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings.

[0056] Embodiment 1:

[0057] This embodiment provides a surgical system, which includes a control terminal and a surgical robot. The surgical robot includes a plurality of instrument rods 1; Figure 1 As shown, each instrument rod 1 includes an instrument box 10, a straight tube 20, a flexible arm 30, an end tool 40 and a plurality of driving members (not shown in the figure) connected in sequence from the proximal end to the distal end; illustratively, the end tool 40 can be a surgical tool for performing surgical operations, such as an electric cauterizer, a clamp, a stapler, a shears, an imaging device (such as an endoscope or an ultrasound probe), and the like.

[0058] The flexible arm 30 is provided with a plurality of snake bone components connected in sequence, one end of the plurality of driving members is inserted into the flexible arm 30, and the other end of the plurality of driving members is connected to the driving unit in the instrument box 10 through the straight tube 20. When performing surgery on a patient, part of the flexible arm 30 and the end tool 40 are inserted into the patient's body, and the doctor remotely controls the rotation of the driving unit through the control end. After the driving unit rotates, the driving member is retracted and the flexible arm 30 is bent in the corresponding direction. During the bending process of the flexible arm 30, the end tool 40 is driven to move. When the flexible arm 30 is bent at a certain angle, the end tool 40 is driven to move to a specified position. After the end tool 40 moves to the specified position, the patient can be operated by operating the end tool 40.

[0059] However, in practice, when the flexible arm 30 bends, the snake bone component in the flexible arm 30 will move sideways to the flexible arm 30 under the action of external load to produce S-shaped deformation. The appearance of S-shaped deformation will cause the bending posture of the flexible arm 30 to be unstable when bending in the corresponding direction, and finally cause the flexible arm 30 to be unable to drive the end tool 40 to move to the specified position, resulting in poor control accuracy and affecting the smooth progress of the surgical operation. In order to solve the above problems, this embodiment provides a flexible arm 30, and the structure of the flexible arm 30 in this embodiment is explained in detail below:

[0060] The flexible arm 30 in this embodiment includes a first snake bone component 31, a second snake bone component 32, a first constraint 331 and a second constraint 332; the first snake bone component 31 can rotate around a first rotation axis and a second rotation axis which are parallel to each other, and the second snake bone component 32 can rotate around a third rotation axis and a fourth rotation axis which are parallel to each other, the second rotation axis is parallel to the third rotation axis, and the first rotation axis, the second rotation axis, the third rotation axis and the fourth rotation axis are all located in the first plane 34; Figure 2 and Figure 3 As shown, the second plane 35 is orthogonal to the first plane 34, and the intersection line of the second plane 35 and the first plane 34 is the axis of the flexible arm 30. The flexible arm 30 has a first projection on the second plane 35. In the first projection, the first constraint 331 and the second constraint 332 are symmetrical about the first plane 34; in the first projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31 and the second snake bone component 32 in a direction parallel to the axis of the flexible arm 30, and cross between the first snake bone component 31 and the second snake bone component 32.

[0061] Specifically, Figure 2 and Figure 3As shown, the flexible arm 30 may include a first plate 391, a second plate 392, a connecting member 395, a third plate 393 and a fourth plate 394 arranged in sequence, the first plate 391 and the second plate 392 are connected by a hinge structure to form a first snake bone assembly 31, in which the first plate 391 rotates around a first rotation axis, and the second plate 392 rotates around a second rotation axis; the second plate 392 is connected to the third plate 393 through the connecting member 395; the third plate 393 and the fourth plate 394 are connected by a hinge structure to form a second snake bone assembly 32, in which the third plate 393 rotates around a third rotation axis, and the fourth plate 394 rotates around a fourth rotation axis. Among them, a first support structure may be provided between the first plate 391 and the second plate 392 in the first serpentine assembly 31, and the distance between the first rotation axis and the second rotation axis is always kept constant by providing the first support structure; a second support structure may also be provided between the third plate 393 and the fourth plate 394 in the second serpentine assembly 32, and the distance between the third rotation axis and the fourth rotation axis is always kept constant by providing the second support structure. The first support structure and the second support structure may be a top-to-top circular arc structure, or the first support structure and the second support structure may be a connecting pin assembly, and the specific structure of the top-to-top circular arc and the specific structure of the connecting pin assembly are the same as those in the prior art, and will not be described in detail here.

[0062] In the first projection, the first constraint member 331 and the second constraint member 332 may intersect at the second plate 392, the third plate 393 and the connecting member 395. Figure 2 and Figure 3 As shown, the connecting member 395 is used to connect the first snake bone component 31 and the second snake bone component 32. Figure 2 As shown, the connecting member 395 can be a thin tube with a relatively small diameter, or, as shown in FIG. Figure 3 As shown, the connecting member 395 can be a thick tube with a relatively large diameter.

[0063] When the first disk 391 rotates around the first rotation axis, the second disk 392 rotates around the second rotation axis, the third disk 393 rotates around the third rotation axis, and the fourth disk 394 rotates around the fourth rotation axis, the flexible arm 30 will move to Figure 2 When the flexible arm 30 is bent in the direction of P1 or P2 Figure 2When the flexible arm 30 is bent in the P1 direction, the lengths of the first constraint member 331 and the second constraint member 332 at the first plate 391, the second plate 392, the third plate 393, the fourth plate 394 and the connecting member 395 remain unchanged; further, when the flexible arm 30 is bent, the first plate 391 and the second plate 392 always maintain symmetrical rotation, and the third plate 393 and the fourth plate 394 always maintain symmetrical rotation, which makes the length extension of the first constraint member 331 between the first plate 391 and the second plate 392 equal to the length shortening of the first constraint member 331 between the third plate 393 and the fourth plate 394 when the flexible arm 30 is bent, and the length of the first constraint member 331 remains unchanged; the length shortening of the second constraint member 332 between the first plate 391 and the second plate 392 is equal to the length extension of the second constraint member 332 between the third plate 393 and the fourth plate 394, and the length of the second constraint member 332 remains unchanged.

[0064] When the flexible arm 30 is bent, if the first serpentine component 31 and the second serpentine component 32 in the flexible arm 30 move sideways to produce S-shaped deformation, the lengths of the first restraint member 331 and the second restraint member 332 will change. In this embodiment, by making the first restraint member 331 and the second restraint member 332 pass through the flexible arm 30 in a specific manner, the lengths of the first restraint member 331 and the second restraint member 332 can remain unchanged when the flexible arm 30 is bent, thereby constraining the S-shaped deformation caused by the lateral movement of the first serpentine component 31 and the second serpentine component 32 when the flexible arm 30 is bent, so that the flexible arm 30 can be bent in the corresponding direction with a fixed posture. When the flexible arm 30 is bent in the corresponding direction with a fixed posture, it can drive the end tool 40 to the specified position, fully ensuring the smooth progress of the surgical operation and improving the control accuracy of the flexible arm 30.

[0065] Embodiment 2:

[0066] like Figure 4 As shown, the flexible arm 30 includes a first snake bone element 301, a second snake bone element 302, a third snake bone element 303, a fourth snake bone element 304 and a fifth snake bone element 305 arranged in sequence; the first snake bone element 301 and the second snake bone element 302 are connected by a hinge structure to form a first snake bone component 31, the second snake bone element 302 and the third snake bone element 303 are connected by a hinge structure to form a third snake bone component 36, the third snake bone element 303 and the fourth snake bone element 304 are connected by a hinge structure to form a second snake bone component 32; the fourth snake bone element 304 and the fifth snake bone element 305 are connected by a hinge structure to form a fourth snake bone component 37.

[0067] The first snake bone component 31 can rotate around the parallel first rotation axis 311 and the second rotation axis 312; wherein the first snake bone element 301 in the first snake bone component 31 rotates around the first rotation axis 311, and the second snake bone element 302 rotates around the second rotation axis 312; the third snake bone component 36 can rotate around the parallel fifth rotation axis 361 and the sixth rotation axis 362; wherein the second snake bone element 302 in the third snake bone component 36 rotates around the fifth rotation axis 361, and the third snake bone element 303 rotates around the sixth rotation axis 36 2 rotation; the second serpentine assembly 32 rotates around the third rotation axis 321 and the fourth rotation axis 322 which are parallel to each other; wherein the third serpentine element 303 in the second serpentine assembly 32 rotates around the third rotation axis 321, and the fourth serpentine element 304 rotates around the fourth rotation axis 322; the fourth serpentine assembly 37 can rotate around the seventh rotation axis 371 and the eighth rotation axis 372 which are parallel to each other; wherein the fourth serpentine element 304 can rotate around the seventh rotation axis 371, and the fifth serpentine element 305 can rotate around the eighth rotation axis 372. The first rotation axis 311, the second rotation axis 312, the third rotation axis 321 and the fourth rotation axis 322 are parallel and all located in the first plane 34; the fifth rotation axis 361, the sixth rotation axis 362, the seventh rotation axis 371 and the eighth rotation axis 372 are parallel and all located in the second plane 35. In this application, this arrangement of the serpentine assemblies is referred to as an "ABAB" arrangement. In this embodiment, a first supporting structure may be provided between the first serpentine element 301 and the second serpentine element 302, and the distance between the first rotation axis 311 and the second rotation axis 312 is always kept constant by providing the first supporting structure; a second supporting structure may be provided between the second serpentine element 302 and the third serpentine element 303, and the distance between the fifth rotation axis 361 and the sixth rotation axis 362 is always kept constant by providing the second supporting structure; a third supporting structure may be provided between the third serpentine element 303 and the fourth serpentine element 304, and the distance between the third rotation axis 321 and the fourth rotation axis 322 is always kept constant by providing the third supporting structure; a fourth supporting structure may be provided between the fourth serpentine element 304 and the fifth serpentine element 305, and the distance between the seventh rotation axis 371 and the eighth rotation axis 372 is always kept constant by providing the fourth supporting structure. The first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure can be top arc structures, or the first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure can be connecting pin assemblies. The specific structures of the top arcs and the specific structures of the connecting pin assemblies are the same as those in the prior art and will not be repeated here.

[0068] like Figure 5As shown, the flexible arm 30 has a first projection on the second plane 35, and in the first projection, the first constraint 331 and the second constraint 332 are symmetrical about the first plane 34; in the first projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along the direction parallel to the axis of the flexible arm 30, and in the first projection, the first constraint 331 and the second constraint 332 cross in the second snake bone element 302 or the third snake bone element 303. Figure 5 Only the first constraint member 331 and the second constraint member 332 are shown to cross in the second snake bone component 302 in the first projection, and the first constraint member 331 and the second constraint member 332 are not shown to cross in the third snake bone component 303 in the first projection.

[0069] like Figure 6 As shown, the flexible arm 30 has a second projection on the first plane 34, and in the second projection, the first constraint 331 and the second constraint 332 are symmetrical about the second plane 35. In the second projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along a direction parallel to the axis of the flexible arm 30. In the second projection, the first constraint 331 and the second constraint 332 cross in the third snake bone element 303 or the fourth snake bone element 304. Figure 6 Only the situation that the first constraint member 331 and the second constraint member 332 cross in the fourth snake bone element 304 in the second projection is shown, and the situation that the first constraint member 331 and the second constraint member 332 cross in the third snake bone element 303 in the second projection is not shown.

[0070] In this embodiment, when the four snake-bone components in the flexible arm 30 rotate, the flexible arm 30 will bend in the corresponding direction; when the flexible arm 30 bends, the length of the first constraint 331 and the second constraint 332 in each snake-bone component remains unchanged; further, when the flexible arm 30 bends, the two snake-bone components in each snake-bone component always maintain symmetrical rotation, which makes the length change k1 of the first constraint 331 in the first snake-bone component 31 equal to the length change k2 of the first constraint 331 in the second snake-bone component 32, wherein one of k1 and k2 is the elongation and the other is the shortening; the length change k3 of the second constraint 332 in the first snake-bone component 31 is equal to the length change k4 of the second constraint 332 in the second snake-bone component 32, wherein one of k3 and k4 is the elongation and the other is the shortening; when k1 is the shortening, k3 is the elongation; when k1 is the elongation, k3 is the shortening.

[0071] The length change k5 of the first constraint member 331 in the third serpentine component 36 is equal to the length change k6 of the first constraint member 331 in the fourth serpentine component 304, wherein k5 and k6 are one of the elongation and the other of the shortening; the length change k7 of the second constraint member 332 in the third serpentine component 36 is equal to the length change k8 of the second constraint member 332 in the fourth serpentine component 37, wherein k7 and k8 are one of the elongation and the other of the shortening, when k5 is the shortening, k7 is the elongation; when k5 is the elongation, k7 is the shortening.

[0072] It can be seen from the above content that in this embodiment, during the bending of the flexible arm 30, the lengths of the first constraint member 331 and the second constraint member 332 remain unchanged, which can also restrain the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 bends.

[0073] The following specifically describes the way in which the first restraining member 331 and the second restraining member 332 are inserted into the flexible arm 30:

[0074] like Figure 7 As shown, each snake bone element is provided with a first hole 306, a second hole 307, a third hole 308 and a fourth hole 309, the first hole 306 and the second hole 307 are located on one side of the first plane 34, the third hole 308 and the fourth hole 309 are located on the other side of the first plane 34, the first hole 306 and the third hole 308 are symmetrical about the first plane 34, and the second hole 307 and the fourth hole 309 are symmetrical about the first plane 34; the first holes 306 on all the snake bone elements are coaxially arranged, the second holes 307 on all the snake bone elements are coaxially arranged, the third holes 308 on all the snake bone elements are coaxially arranged, and the fourth holes 309 on all the snake bone elements are coaxially arranged.

[0075] Wearing method 1:

[0076] In this insertion method, the insertion angle of the first constraint member 331 and the second constraint member 332 is 180°, wherein the insertion angle of the first constraint member 331 refers to the insertion point of the first constraint member 331 on the flexible arm 30 is A1, and the exit point of the first constraint member 331 on the flexible arm 30 is A2. When A1, A2 and the axis of the flexible arm 30 are all projected onto a plane perpendicular to the axis of the flexible arm 30, the degree of the central angle that A1, A2 and the axis of the flexible arm 30 can form; the insertion angle of the second constraint member 332 refers to the insertion point of the second constraint member on the flexible arm 30 is A3, and the exit point of the second constraint member 332 on the flexible arm 30 is A4. When A3, A4 and the axis of the flexible arm 30 are all projected onto a plane perpendicular to the axis of the flexible arm 30, the degree of the central angle that A3, A4 and the axis of the flexible arm 30 can form.

[0077] When the insertion angle of the first restraining member 331 and the second restraining member 332 is 180°, the first restraining member 331 and the second restraining member 332 may have the following insertion modes according to different intersection positions:

[0078] (1) Figure 8 As shown, the first restraining member 331 sequentially passes through the first hole 306 on the first snake bone element 301, the first hole 306 and the third hole 308 on the second snake bone element 302, the third hole 308 on the third snake bone element 303, the third hole 308 and the fourth hole 309 on the fourth snake bone element 304, and the fourth hole 309 on the fifth snake bone element 305; the second restraining member 332 sequentially passes through the fourth hole 309 on the first snake bone element 301, the fourth hole 309 on the second snake bone element 302, and the fourth hole 309 on the fifth snake bone element 305. The first and second restraining members 331 and 332 are respectively provided on the first and second serpentine members 302, the second hole 307 on the third serpentine member 303, the second hole 307 and the first hole 306 on the fourth serpentine member 304, and the first hole 306 on the fifth serpentine member 305; when the first restraining member 331 and the second restraining member 332 are inserted in the above manner, in the first projection, the first restraining member 331 and the second restraining member 332 cross in the second serpentine member 302, and in the second projection, the first restraining member 331 and the second restraining member 332 cross in the fourth serpentine member 304.

[0079] (2) The first restraining member 331 passes through the first hole 306 of the first serpentine element 301, the first hole 306 of the second serpentine element 302, the first hole 306 and the third hole 308 of the third serpentine element 303, the third hole 308 and the fourth hole 309 of the fourth serpentine element 304, and the fourth hole 309 of the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 of the first serpentine element 301, the fourth hole 309 of the second serpentine element 302, the first hole 306 and the third hole 308 of the third serpentine element 303, the third hole 308 and the fourth hole 309 of the fourth serpentine element 304, and the fourth hole 309 of the fifth serpentine element 305 in sequence. The fourth hole 309 and the second hole 307 on the three snake bone components 303, the second hole 307 and the first hole 306 on the fourth snake bone component 304, and the first hole 306 on the fifth snake bone component 305; when the first constraint member 331 and the second constraint member 332 are inserted in the above manner, in the first projection, the first constraint member 331 and the second constraint member 332 cross in the third snake bone component 303, and in the second projection, the first constraint member 331 and the second constraint member 332 cross in the fourth snake bone component 304.

[0080] (3) The first restraining member 331 passes through the first hole 306 on the first serpentine element 301, the first hole 306 and the third hole 308 on the second serpentine element 302, the third hole 308 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 on the first serpentine element 301, the fourth hole 309 and the second hole 307 on the second serpentine element 302, the second hole 307 and the first hole 306 on the third serpentine element 303, the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are installed in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the second projection.

[0081] Of course, it can be understood that when the first constraint member 331 and the second constraint member 332 are inserted in the above manner, the third constraint member 333 and the fourth constraint member 334 may also be provided in the flexible arm 30, and the insertion angles of the third constraint member 333 and the fourth constraint member 334 are both 180°. The insertion method of the third constraint member 333 and the fourth constraint member 334 is described below, wherein, according to different intersection positions, the third constraint member 333 and the fourth constraint member 334 may have the following insertion methods:

[0082] (1) Fig. 9 As shown, the third restraining member 333 sequentially passes through the third hole 308 on the first snake bone element 301, the third hole 308 and the first hole 306 on the second snake bone element 302, the first hole 306 on the third snake bone element 303, the first hole 306 and the second hole 307 on the fourth snake bone element 304, and the second hole 307 on the fifth snake bone element 305; the fourth restraining member 334 sequentially passes through the second hole 307 on the first snake bone element 301, the second hole 307 and the fourth hole 309 on the second snake bone element 302, the fourth hole 309 on the third snake bone element 303, the fourth hole 309 and the third hole 308 on the fourth snake bone element 304, and the third hole 308 on the fifth snake bone element 305. When the third restraint member 333 and the fourth restraint member 334 are installed in the above manner, the third restraint member 333 and the fourth restraint member 334 cross in the second snake element 302 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the fourth snake element 304 in the second projection.

[0083] (2) The third restraining member 333 sequentially passes through the third hole 308 on the first serpentine element 301, the third hole 308 on the second serpentine element 302, the third hole 308 and the first hole 306 on the third serpentine element 303, the first hole 306 and the second hole 307 on the fourth serpentine element 304, and the second hole 307 on the fifth serpentine element 305; the fourth restraining member 334 sequentially passes through the second hole 307 on the first serpentine element 301, the second hole 307 on the second serpentine element 302, the second hole 307 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 and the third hole 308 on the fourth serpentine element 304, and the third hole 308 on the fifth serpentine element 305. When the third restraint member 333 and the fourth restraint member 334 are inserted as described above, the third restraint member 333 and the fourth restraint member 334 cross in the third snake element 303 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the fourth snake element 304 in the second projection.

[0084] (3) The third restraining member 333 sequentially passes through the third hole 308 on the first serpentine element 301, the third hole 308 and the first hole 306 on the second serpentine element 302, the first hole 306 and the second hole 307 on the third serpentine element 303, the second hole 307 on the fourth serpentine element 304, and the second hole 307 on the fifth serpentine element 305; the fourth restraining member 334 sequentially passes through the second hole 307 on the first serpentine element 301, the second hole 307 and the fourth hole 309 on the second serpentine element 302, the fourth hole 309 and the third hole 308 on the third serpentine element 303, the third hole 308 on the fourth serpentine element 304, and the third hole 308 on the fifth serpentine element 305. When the third restraint member 333 and the fourth restraint member 334 are inserted as described above, the third restraint member 333 and the fourth restraint member 334 cross in the second snake element 302 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the third snake element 303 in the second projection.

[0085] The principle of the third restraint member 333 and the fourth restraint member 334 restraining the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent is the same as that of the first restraint member 331 and the second restraint member 332, which will not be repeated here. In order to better restrain the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent, the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 can be set in the flexible arm 30 at the same time.

[0086] Wearing method 2:

[0087] In this insertion method, the insertion angle of the first constraint member 331 and the second constraint member 332 is 270°; the definition of the insertion angle is detailed in the above embodiment and will not be repeated here. When the insertion angle of the first constraint member 331 and the second constraint member 332 is 270°, the first constraint member 331 and the second constraint member 332 can have the following insertion methods according to different intersection positions:

[0088] (1) Fig.10 As shown, the first restraining member 331 passes through the third hole 308 on the first snake bone element 301, the third hole 308 and the second hole 307 on the second snake bone element 302, the second hole 307 on the third snake bone element 303, the second hole 307 and the first hole 306 on the fourth snake bone element 304, and the first hole 306 on the fifth snake bone element 305 in sequence; the second restraining member 332 passes through the second hole 307 on the first snake bone element 301, the second hole 307 and the third hole 308 on the second snake bone element 302, the third hole 308 on the third snake bone element 303, the third hole 308 and the fourth hole 309 on the fourth snake bone element 304, and the fourth hole 309 on the fifth snake bone element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are inserted in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the fourth snake element 304 in the second projection.

[0089] (2) The first restraining member 331 passes through the third hole 308 on the first serpentine element 301, the third hole 308 on the second serpentine element 302, the third hole 308 and the second hole 307 on the third serpentine element 303, the second hole 307 and the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the second hole 307 on the first serpentine element 301, the second hole 307 on the second serpentine element 302, the third hole 308 and the second hole 307 on the third serpentine element 303 in sequence The second hole 307 and the third hole 308 on the third snake bone element 303, the third hole 308 and the fourth hole 309 on the fourth snake bone element 304, and the fourth hole 309 on the fifth snake bone element 305; when the first constraint member 331 and the second constraint member 332 are inserted in the above manner, in the first projection, the first constraint member 331 and the second constraint member 332 cross in the third snake bone element 303, and in the second projection, the first constraint member 331 and the second constraint member 332 cross in the fourth snake bone element 304.

[0090] (3) The first restraining member 331 passes through the third hole 308 on the first serpentine element 301, the third hole 308 and the second hole 307 on the second serpentine element 302, the second hole 307 and the first hole 306 on the third serpentine element 303, the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the second hole 307 on the first serpentine element 301, the second hole 307 and the third hole 308 on the second serpentine element 302, the third hole 308 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are installed in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the second projection.

[0091] Wearing method three:

[0092] In this insertion method, the insertion angle of the first constraint member 331 and the second constraint member 332 is 360°; the definition of the insertion angle is detailed in the above embodiment and will not be repeated here. When the insertion angle of the first constraint member 331 and the second constraint member 332 is 360°, the first constraint member 331 and the second constraint member 332 can have the following insertion methods according to different intersection positions:

[0093] (1) Fig.11 As shown, the first restraining member 331 sequentially passes through the first hole 306 on the first snake bone element 301, the first hole 306 and the fourth hole 309 on the second snake bone element 302, the fourth hole 309 on the third snake bone element 303, the fourth hole 309 and the first hole 306 on the fourth snake bone element 304, and the first hole 306 on the fifth snake bone element 305; the second restraining member 332 sequentially passes through the fourth hole 309 on the first snake bone element 301, the fourth hole 309 on the second snake bone element 302, and the fourth hole 309 on the third snake bone element 303. a hole 306 on the first serpentine element 306, a first hole 306 on the third serpentine element 303, a first hole 306 and a fourth hole 309 on the fourth serpentine element 304, and a fourth hole 309 on the fifth serpentine element 305; when the first constraint member 331 and the second constraint member 332 are penetrated in the above manner, in the first projection, the first constraint member 331 and the second constraint member 332 cross in the second serpentine element 302, and in the second projection, the first constraint member 331 and the second constraint member 332 cross in the fourth serpentine element 304.

[0094] (2) The first restraining member 331 passes through the first hole 306 of the first serpentine element 301, the first hole 306 of the second serpentine element 302, the first hole 306 and the fourth hole 309 of the third serpentine element 303, the fourth hole 309 and the first hole 306 of the fourth serpentine element 304, and the first hole 306 of the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 of the first serpentine element 301, the fourth hole 309 of the second serpentine element 302, the first hole 306 and the fourth hole 309 of the fourth serpentine element 304, and the first hole 306 of the fifth serpentine element 305 in sequence. The fourth hole 309 and the first hole 306 on the third snake bone element 303, the first hole 306 and the fourth hole 309 on the fourth snake bone element 304, and the fourth hole 309 on the fifth snake bone element 305; when the first constraint member 331 and the second constraint member 332 are inserted in the above manner, in the first projection, the first constraint member 331 and the second constraint member 332 cross in the third snake bone element 303, and in the second projection, the first constraint member 331 and the second constraint member 332 cross in the fourth snake bone element 304.

[0095] (3) The first restraining member 331 passes through the first hole 306 on the first serpentine element 301, the first hole 306 and the fourth hole 309 on the second serpentine element 302, the fourth hole 309 and the first hole 306 on the third serpentine element 303, the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 on the first serpentine element 301, the fourth hole 309 and the first hole 306 on the second serpentine element 302, the first hole 306 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are installed in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the second projection.

[0096] Embodiment three:

[0097] like Fig.12 As shown, the flexible arm 30 includes a first snake bone element 301, a second snake bone element 302, a third snake bone element 303, a fourth snake bone element 304 and a fifth snake bone element 305 arranged in sequence; the first snake bone element 301 and the second snake bone element 302 are connected by a hinge structure to form a first snake bone component 31, the second snake bone element 302 and the third snake bone element 303 are connected by a hinge structure to form a third snake bone component 36, the third snake bone element 303 and the fourth snake bone element 304 are connected by a hinge structure to form a fourth snake bone component 37, and the fourth snake bone element 304 and the fifth snake bone element 305 are connected by a hinge structure to form a second snake bone component 32.

[0098] The first snake bone component 31 can rotate around the parallel first rotation axis 311 and the second rotation axis 312; wherein the first snake bone element 301 in the first snake bone component 31 rotates around the first rotation axis 311, and the second snake bone element 302 rotates around the second rotation axis 312; the third snake bone component 36 can rotate around the parallel fifth rotation axis 361 and the sixth rotation axis 362; wherein the second snake bone element 302 in the third snake bone component 36 rotates around the fifth rotation axis 361, and the third snake bone element 303 rotates around the sixth rotation axis 36 2 rotation; the second serpentine component 32 rotates around the third rotation axis 321 and the fourth rotation axis 322 which are parallel to each other; wherein the third serpentine element 303 in the second serpentine component 32 rotates around the third rotation axis 321, and the fourth serpentine element 304 rotates around the fourth rotation axis 322; the fourth serpentine component 37 can rotate around the seventh rotation axis 371 and the eighth rotation axis 372 which are parallel to each other; wherein the fourth serpentine element 304 can rotate around the seventh rotation axis 371, and the fifth serpentine element 305 can rotate around the eighth rotation axis 372. The first rotation axis 311, the second rotation axis 312, the third rotation axis 321 and the fourth rotation axis 322 are parallel and all located in the first plane 34; the fifth rotation axis 361, the sixth rotation axis 362, the seventh rotation axis 371 and the eighth rotation axis 372 are parallel and all located in the second plane 35. In this application, this arrangement of the serpentine components is referred to as an "ABBA" arrangement. Among them, a first supporting structure may be provided between the first serpentine element 301 and the second serpentine element 302, and the distance between the first rotation axis 311 and the second rotation axis 312 is always kept constant by providing the first supporting structure; a second supporting structure may be provided between the second serpentine element 302 and the third serpentine element 303, and the distance between the fifth rotation axis 361 and the sixth rotation axis 362 is always kept constant by providing the second supporting structure; a third supporting structure may be provided between the third serpentine element 303 and the fourth serpentine element 304, and the distance between the seventh rotation axis 371 and the eighth rotation axis 372 is always kept constant by providing the third supporting structure; a fourth supporting structure may be provided between the fourth serpentine element 304 and the fifth serpentine element 305, and the distance between the third rotation axis 321 and the fourth rotation axis 322 is always kept constant by providing the fourth supporting structure.

[0099] like Fig.13 As shown, the flexible arm 30 has a first projection on the second plane 35, and in the first projection, the first constraint 331 and the second constraint 332 are symmetrical about the first plane 34; in the first projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along the direction parallel to the axis of the flexible arm 30, and in the first projection, the first constraint 331 and the second constraint 332 cross in the second snake bone element 302 or the fourth snake bone element 304. Fig.13 Only the first constraint member 331 and the second constraint member 332 are shown to cross in the second snake element 302 in the first projection, and the first constraint member 331 and the second constraint member 332 are not shown to cross in the fourth snake element 304 in the first projection.

[0100] like Fig.14 As shown, the flexible arm 30 has a second projection on the first plane 34, and in the second projection, the first constraint 331 and the second constraint 332 are symmetrical about the second plane 35. In the second projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along a direction parallel to the axis of the flexible arm 30. In the second projection, the first constraint 331 and the second constraint 332 cross in the third snake bone component 303.

[0101] In this embodiment, the principle of the first restraining member 331 and the second restraining member 332 restraining the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent is the same as that of the above-mentioned embodiment 2, which will not be repeated here.

[0102] The following describes the arrangement of the first restraining member 331 and the second restraining member 332 in the flexible arm 30:

[0103] Wearing method 1:

[0104] In this insertion method, the insertion angle of the first constraint member 331 and the second constraint member 332 is 180°; the definition of the insertion angle is detailed in the above embodiment and will not be repeated here. When the insertion angle of the first constraint member 331 and the second constraint member 332 is 180°, the first constraint member 331 and the second constraint member 332 can have the following insertion methods according to different intersection positions:

[0105] (1) Fig.15As shown, the first restraining member 331 passes through the first hole 306 on the first snake bone element 301, the first hole 306 and the third hole 308 on the second snake bone element 302, the third hole 308 and the fourth hole 309 on the third snake bone element 303, the fourth hole 309 on the fourth snake bone element 304, and the fourth hole 309 on the fifth snake bone element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 on the first snake bone element 301, the fourth hole 309 and the second hole 307 on the second snake bone element 302, the second hole 307 and the first hole 306 on the third snake bone element 303, the first hole 306 on the fourth snake bone element 304, and the first hole 306 on the fifth snake bone element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are installed in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the second projection.

[0106] (2) The first restraining member 331 passes through the third hole 308 on the first serpentine element 301, the third hole 308 on the second serpentine element 302, the third hole 308 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 and the second hole 307 on the fourth serpentine element 304, and the second hole 307 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the second hole 307 on the first serpentine element 301, the second hole 307 on the second serpentine element 302, the second hole 307 and the first hole 306 on the third serpentine element 303, the first hole 306 and the third hole 308 on the fourth serpentine element 304, and the third hole 308 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are inserted as described above, the first restraint member 331 and the second restraint member 332 cross in the fourth snake element 304 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake element 303 in the second projection.

[0107] Of course, it can be understood that when the first constraint member 331 and the second constraint member 332 are inserted in the above manner, the third constraint member 333 and the fourth constraint member 334 may also be provided in the flexible arm 30, and the insertion angles of the third constraint member 333 and the fourth constraint member 334 are both 180°. The insertion method of the third constraint member 333 and the fourth constraint member 334 is described below, wherein, according to different intersection positions, the third constraint member 333 and the fourth constraint member 334 may have the following insertion methods:

[0108] (1) The third restraining member 333 passes through the third hole 308 on the first snake bone element 301, the third hole 308 and the first hole 306 on the second snake bone element 302, the first hole 306 and the second hole 307 on the third snake bone element 303, the second hole 307 on the fourth snake bone element 304, and the second hole 307 on the fifth snake bone element 305 in sequence; the fourth restraining member 334 passes through the second hole 307 on the first snake bone element 301, the second hole 307 and the fourth hole 309 on the second snake bone element 302, the fourth hole 309 and the third hole 308 on the third snake bone element 303, the third hole 308 on the fourth snake bone element 304, and the third hole 308 on the fifth snake bone element 305 in sequence. When the third restraint member 333 and the fourth restraint member 334 are inserted as described above, the third restraint member 333 and the fourth restraint member 334 cross in the second snake element 302 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the third snake element 303 in the second projection.

[0109] (2) The third restraining member 333 sequentially passes through the fourth hole 309 on the first serpentine element 301, the fourth hole 309 on the second serpentine element 302, the fourth hole 309 and the third hole 308 on the third serpentine element 303, the third hole 308 and the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305; the fourth restraining member 334 sequentially passes through the first hole 306 on the first serpentine element 301, the first hole 306 on the second serpentine element 302, the first hole 306 and the second hole 307 on the third serpentine element 303, the second hole 307 and the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305. When the third restraint member 333 and the fourth restraint member 334 are inserted as described above, the third restraint member 333 and the fourth restraint member 334 cross in the fourth snake element 304 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the third snake element 303 in the second projection.

[0110] The principle of the third restraint member 333 and the fourth restraint member 334 restraining the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent is the same as the first restraint member 331 and the second restraint member 332 in the above-mentioned second embodiment, and will not be repeated here. In order to better restrain the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent, the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 can be set in the flexible arm 30 at the same time.

[0111] Wearing method 2:

[0112] In this insertion method, the insertion angle of the first constraint member 331 and the second constraint member 332 is 270°; the definition of the insertion angle is detailed in the above embodiment and will not be repeated here. When the insertion angle of the first constraint member 331 and the second constraint member 332 is 270°, the first constraint member 331 and the second constraint member 332 can have the following insertion methods according to different intersection positions:

[0113] (1) The first restraining member 331 passes through the third hole 308 on the first serpentine element 301, the third hole 308 and the second hole 307 on the second serpentine element 302, the second hole 307 and the first hole 306 on the third serpentine element 303, the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the second hole 307 on the first serpentine element 301, the second hole 307 and the third hole 308 on the second serpentine element 302, the third hole 308 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are installed in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the second projection.

[0114] (2) The first restraining member 331 passes through the third hole 308 on the first serpentine element 301, the third hole 308 on the second serpentine element 302, the third hole 308 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 and the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the second hole 307 on the first serpentine element 301, the second hole 307 on the second serpentine element 302, the second hole 307 and the first hole 306 on the third serpentine element 303, the first hole 306 and the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are inserted as described above, the first restraint member 331 and the second restraint member 332 cross in the fourth snake element 304 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake element 303 in the second projection.

[0115] Wearing method three:

[0116] In this threading method, the threading angle of the first restraint member 331 and the second restraint member 332 is 360°; the definition of the threading angle is detailed in the above embodiment and will not be repeated here. When the threading angle of the first restraint member 331 and the second restraint member 332 is 360°, the first restraint member 331 and the second restraint member 332 can have the following threading methods according to different intersection positions:

[0117] (1) The first restraining member 331 passes through the first hole 306 on the first serpentine element 301, the first hole 306 and the fourth hole 309 on the second serpentine element 302, the fourth hole 309 and the first hole 306 on the third serpentine element 303, the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 on the first serpentine element 301, the fourth hole 309 and the first hole 306 on the second serpentine element 302, the first hole 306 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are installed in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the second projection.

[0118] (2) The first restraining member 331 passes through the first hole 306 on the first serpentine element 301, the first hole 306 on the second serpentine element 302, the first hole 306 and the fourth hole 309 on the third serpentine element 303, the fourth hole 309 and the first hole 306 on the fourth serpentine element 304, and the first hole 306 on the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the fourth hole 309 on the first serpentine element 301, the fourth hole 309 on the second serpentine element 302, the fourth hole 309 and the first hole 306 on the third serpentine element 303, the first hole 306 and the fourth hole 309 on the fourth serpentine element 304, and the fourth hole 309 on the fifth serpentine element 305 in sequence. When the first restraint member 331 and the second restraint member 332 are inserted as described above, the first restraint member 331 and the second restraint member 332 cross in the fourth snake element 304 in the first projection, and the first restraint member 331 and the second restraint member 332 cross in the third snake element 303 in the second projection.

[0119] Embodiment 4:

[0120] In this embodiment, Figure 4As shown, the flexible arm 30 includes a first snake bone element 301, a second snake bone element 302, a third snake bone element 303, a fourth snake bone element 304 and a fifth snake bone element 305 arranged in sequence; the first snake bone element 301 and the second snake bone element 302 are connected by a hinge structure to form a first snake bone component 31, the second snake bone element 302 and the third snake bone element 303 are connected by a hinge structure to form a third snake bone component 36, the third snake bone element 303 and the fourth snake bone element 304 are connected by a hinge structure to form a second snake bone component 32; the fourth snake bone element 304 and the fifth snake bone element 305 are connected by a hinge structure to form a fourth snake bone component 37.

[0121] The first snake bone component 31 can rotate around the parallel first rotation axis 311 and the second rotation axis 312; wherein the first snake bone element 301 in the first snake bone component 31 rotates around the first rotation axis 311, and the second snake bone element 302 rotates around the second rotation axis 312; the third snake bone component 36 can rotate around the parallel fifth rotation axis 361 and the sixth rotation axis 362; wherein the second snake bone element 302 in the third snake bone component 36 rotates around the fifth rotation axis 361, and the third snake bone element 303 rotates around the sixth rotation axis 36 2 rotation; the second serpentine assembly 32 rotates around the third rotation axis 321 and the fourth rotation axis 322 which are parallel to each other; wherein the third serpentine element 303 in the second serpentine assembly 32 rotates around the third rotation axis 321, and the fourth serpentine element 304 rotates around the fourth rotation axis 322; the fourth serpentine assembly 37 can rotate around the seventh rotation axis 371 and the eighth rotation axis 372 which are parallel to each other; wherein the fourth serpentine element 304 can rotate around the seventh rotation axis 371, and the fifth serpentine element 305 can rotate around the eighth rotation axis 372. The first rotation axis 311, the second rotation axis 312, the third rotation axis 321 and the fourth rotation axis 322 are parallel and all located in the first plane 34; the fifth rotation axis 361, the sixth rotation axis 362, the seventh rotation axis 371 and the eighth rotation axis 372 are parallel and all located in the second plane 35. In this application, this arrangement of the serpentine assemblies is referred to as an "ABAB" arrangement. In this embodiment, a first supporting structure may be provided between the first serpentine element 301 and the second serpentine element 302, and the distance between the first rotation axis 311 and the second rotation axis 312 is always kept constant by providing the first supporting structure; a second supporting structure may be provided between the second serpentine element 302 and the third serpentine element 303, and the distance between the fifth rotation axis 361 and the sixth rotation axis 362 is always kept constant by providing the second supporting structure; a third supporting structure may be provided between the third serpentine element 303 and the fourth serpentine element 304, and the distance between the third rotation axis 321 and the fourth rotation axis 322 is always kept constant by providing the third supporting structure; a fourth supporting structure may be provided between the fourth serpentine element 304 and the fifth serpentine element 305, and the distance between the seventh rotation axis 371 and the eighth rotation axis 372 is always kept constant by providing the fourth supporting structure. The first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure can be top arc structures, or the first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure can be connecting pin assemblies. The specific structures of the top arcs and the specific structures of the connecting pin assemblies are the same as those in the prior art and will not be repeated here.

[0122] In this embodiment, the flexible arm 30 further includes a first restraining member 331, a second restraining member 332, a third restraining member 333 and a fourth restraining member 334; Fig.16As shown, the flexible arm 30 has a first projection on the second plane 35, and in the first projection, the first constraint 331 and the second constraint 332 are symmetrical about the first plane 34; in the first projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 301, the second snake bone component 302, the third snake bone component 36 and the fourth snake bone component 37 along the direction parallel to the axis of the flexible arm 30, and in the first projection, the first constraint 331 and the second constraint 332 cross in the second snake bone component 302 or the third snake bone component 303. Fig.16 Only the first constraint member 331 and the second constraint member 332 are shown to cross in the second snake bone component 302 in the first projection, and the first constraint member 331 and the second constraint member 332 are not shown to cross in the third snake bone component 303 in the first projection.

[0123] like Fig.17 As shown, the flexible arm 30 has a second projection on the first plane 34, and in the second projection, the third constraint member 333 and the fourth constraint member 334 are symmetrical about the second plane 35. In the second projection, the third constraint member 333 and the fourth constraint member 334 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along the direction parallel to the axis of the flexible arm 30. In the second projection, the third constraint member 333 and the fourth constraint member 334 cross in the third snake bone element 303 or the fourth snake bone element 304. Fig.17 Only the situation that the third constraint member 333 and the fourth constraint member 334 cross in the fourth snake element 304 in the second projection is shown, and the situation that the third constraint member 333 and the fourth constraint member 334 cross in the third snake element 303 in the second projection is not shown.

[0124] In this embodiment, when the four snake-bone components in the flexible arm 30 rotate, the flexible arm 30 will bend in the corresponding direction; when the flexible arm 30 bends, the length of the first constraint 331 and the second constraint 332 in each snake-bone component remains unchanged; the length of the first constraint 331 and the second constraint 332 in the third snake-bone component 36 and the fourth snake-bone component 37 remains unchanged; the length of the third constraint 333 and the fourth constraint 334 in each snake-bone component remains unchanged; the length of the third constraint 333 and the fourth constraint 334 in the first snake-bone component 31 and the second snake-bone component 32 remains unchanged; further, when the flexible arm 30 bends, the two snake-bone elements in each snake-bone component always remain symmetrical Rotation, which makes the length change k1 of the first constraint 331 in the first serpentine component 31 equal to the length change k2 of the first constraint 331 in the second serpentine component 32 when the flexible arm 30 is bent, wherein one of k1 and k2 is the elongation and the other is the shortening, and the length of the first constraint 331 remains unchanged; the length change k3 of the second constraint 332 in the first serpentine component 31 is equal to the length change k4 of the second constraint 332 in the second serpentine component 32, wherein one of k3 and k4 is the elongation and the other is the shortening, and the length of the second constraint 332 remains unchanged; wherein, when k1 is the shortening, k3 is the elongation; when k1 is the elongation, k3 is the shortening.

[0125] The length change k5 of the third constraint 333 in the third serpentine assembly 36 is equal to the length change k6 of the third constraint 333 in the fourth serpentine assembly 37, wherein one of k5 and k6 is an elongation and the other is a shortening, and the length of the third constraint 333 remains unchanged. The length change k7 of the fourth constraint 334 in the third serpentine assembly 36 is equal to the length change k8 of the fourth constraint 334 in the fourth serpentine assembly 37, wherein one of k7 and k8 is an elongation and the other is a shortening, and the length of the fourth constraint 334 remains unchanged; wherein, when k5 is a shortening, k7 is an elongation, and when k5 is an elongation, k7 is a shortening.

[0126] It can be seen from the above content that in this embodiment, during the bending of the flexible arm 30, the lengths of the first constraint member 331, the second constraint member 332, the third constraint member 333 and the fourth constraint member 334 remain unchanged, which can also realize the constraint of the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent.

[0127] The following is a detailed description of the insertion method of the first restraining member 331, the second restraining member 332, the third restraining member 333 and the fourth restraining member 334 in the flexible arm 30; wherein, according to different intersection positions, the first restraining member 331, the second restraining member 332, the third restraining member 333 and the fourth restraining member 334 can have the following insertion methods:

[0128] like Fig.18 As shown, each snake bone element is provided with a fifth hole 381, a sixth hole 382, ​​a seventh hole 384 and an eighth hole 383, the fifth hole 381 and the sixth hole 382 are located on the first plane 34 and are symmetrically distributed about the axis of the flexible arm 30, the seventh hole 384 and the eighth hole 383 are located on the second plane 35 and are symmetrically distributed about the axis of the flexible arm 30; the fifth hole 381 on all the snake bone elements is coaxially arranged, the sixth hole 382 on all the snake bone elements is coaxially arranged, the seventh hole 384 on all the snake bone elements is coaxially arranged, and the eighth hole 383 on all the snake bone elements is coaxially arranged.

[0129] (1) Fig.19 As shown, the first restraining member 331 sequentially passes through the eighth hole 383 of the first serpentine element 301, the eighth hole 383 and the seventh hole 384 of the second serpentine element 302, the seventh hole 384 of the third serpentine element 303, the seventh hole 384 of the fourth serpentine element 304 and the seventh hole 384 of the fifth serpentine element 305; the second restraining member 332 sequentially passes through the seventh hole 384 of the first serpentine element 301, the seventh hole 384 and the eighth hole 383 of the second serpentine element 302, the eighth hole 383 of the third serpentine element 303, the eighth hole 383 of the fourth serpentine element 304 and the eighth hole 383 of the fifth serpentine element 305; The three restraining members 333 sequentially pass through the fifth hole 381 of the first snake bone element 301, the fifth hole 381 on the second snake bone element 302, the fifth hole 381 and the sixth hole 382 on the third snake bone element 303, the sixth hole 382 on the fourth snake bone element 304, and the sixth hole 382 on the fifth snake bone element 305; the fourth restraining member 334 sequentially passes through the sixth hole 382 on the first snake bone element 301, the sixth hole 382 on the second snake bone element 302, the sixth hole 382 and the fifth hole 381 on the third snake bone element 303, the fifth hole 381 on the fourth snake bone element 304, and the fifth hole 381 on the fifth snake bone element 305. When the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 are arranged in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the third snake bone element 303 in the second projection.

[0130] (2) The first restraining member 331 passes through the eighth hole 383 of the first serpentine element 301, the eighth hole 383 of the second serpentine element 302, the eighth hole 383 and the seventh hole 384 of the third serpentine element 303, the seventh hole 384 of the fourth serpentine element 304, and the seventh hole 384 of the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the seventh hole 384 of the first serpentine element 301, the seventh hole 384 of the second serpentine element 302, the seventh hole 384 and the eighth hole 383 of the third serpentine element 303, the eighth hole 383 of the fourth serpentine element 304, and the eighth hole 383 of the fifth serpentine element 305 in sequence; The three restraining members 333 sequentially pass through the fifth hole 381 of the first snake bone element 301, the fifth hole 381 on the second snake bone element 302, the fifth hole 381 on the third snake bone element 303, the fifth hole 381 and the sixth hole 382 on the fourth snake bone element 304, and the sixth hole 382 on the fifth snake bone element 305; the fourth restraining member 334 sequentially passes through the sixth hole 382 on the first snake bone element 301, the sixth hole 382 on the second snake bone element 302, the sixth hole 382 on the third snake bone element 303, the sixth hole 382 and the fifth hole 381 on the fourth snake bone element 304, and the fifth hole 381 on the fifth snake bone element 305. When the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 are arranged in the above manner, the first restraint member 331 and the second restraint member 332 cross in the third snake bone element 303 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the fourth snake bone element 304 in the second projection.

[0131] (3) The first restraining member 331 sequentially passes through the eighth hole 383 of the first serpentine element 301, the eighth hole 383 and the seventh hole 384 of the second serpentine element 302, the seventh hole 384 of the third serpentine element 303, the seventh hole 384 of the fourth serpentine element 304 and the seventh hole 384 of the fifth serpentine element 305; the second restraining member 332 sequentially passes through the seventh hole 384 of the first serpentine element 301, the seventh hole 384 and the eighth hole 383 of the second serpentine element 302, the eighth hole 383 of the third serpentine element 303, the eighth hole 383 of the fourth serpentine element 304 and the eighth hole 383 of the fifth serpentine element 305; The three restraining members 333 sequentially pass through the fifth hole 381 of the first snake bone element 301, the fifth hole 381 on the second snake bone element 302, the fifth hole 381 on the third snake bone element 303, the fifth hole 381 and the sixth hole 382 on the fourth snake bone element 304, and the sixth hole 382 on the fifth snake bone element 305; the fourth restraining member 334 sequentially passes through the sixth hole 382 on the first snake bone element 301, the sixth hole 382 on the second snake bone element 302, the sixth hole 382 on the third snake bone element 303, the sixth hole 382 and the fifth hole 381 on the fourth snake bone element 304, and the fifth hole 381 on the fifth snake bone element 305. When the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 are arranged in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the fourth snake bone element 304 in the second projection.

[0132] In this embodiment, the seventh hole 384 and the eighth hole 383 on the second snake bone component 302 are located on the fifth rotation axis 361, the seventh hole 384 and the eighth hole 383 on the third snake bone component 303 are located on the sixth rotation axis 362, the seventh hole 384 and the eighth hole 383 on the fourth snake bone component 304 are located on the seventh rotation axis 371, and the seventh hole 384 and the eighth hole 383 on the fifth snake bone component 305 are located on the eighth rotation axis 372. This arrangement of the holes allows the first constraint member 331 and the second constraint member 332 to be inserted into the holes in the above manner, if the flexible arm 30 is bent, the lengths of the first constraint member 331 and the second constraint member 332 in the third snake bone component 36 and the fourth snake bone component 37 remain unchanged.

[0133] Furthermore, in this embodiment, the fifth hole 381 and the sixth hole 382 on the first snake bone component 301 are located on the first rotation axis 311, the fifth hole 381 and the sixth hole 382 on the second snake bone component 302 are located on the second rotation axis 312, the fifth hole 381 and the sixth hole 382 on the third snake bone component 303 are located on the third rotation axis 321, and the fifth hole 381 and the sixth hole 382 on the fourth snake bone component 304 are located on the fourth rotation axis 322. This arrangement of the holes allows the third constraint member 333 and the fourth constraint member 334 to be inserted into the holes in the above manner, if the flexible arm 30 is bent, the lengths of the third constraint member 333 and the fourth constraint member 334 in the first snake bone component 31 and the second snake bone component 32 remain unchanged.

[0134] Embodiment five:

[0135] In this embodiment, Fig.12 As shown, the flexible arm 30 includes a first snake bone element 301, a second snake bone element 302, a third snake bone element 303, a fourth snake bone element 304 and a fifth snake bone element 305 arranged in sequence; the first snake bone element 301 and the second snake bone element 302 are connected by a hinge structure to form a first snake bone component 31, the second snake bone element 302 and the third snake bone element 303 are connected by a hinge structure to form a third snake bone component 36, the third snake bone element 303 and the fourth snake bone element 304 are connected by a hinge structure to form a fourth snake bone component 37, and the fourth snake bone element 304 and the fifth snake bone element 305 are connected by a hinge structure to form a second snake bone component 32.

[0136] The first snake bone component 31 can rotate around the parallel first rotation axis 311 and the second rotation axis 312; wherein the first snake bone element 301 in the first snake bone component 31 rotates around the first rotation axis 311, and the second snake bone element 302 rotates around the second rotation axis 312; the third snake bone component 36 can rotate around the parallel fifth rotation axis 361 and the sixth rotation axis 362; wherein the second snake bone element 302 in the third snake bone component 36 rotates around the fifth rotation axis 361, and the third snake bone element 303 rotates around the sixth rotation axis 36 2 rotation; the second serpentine component 32 rotates around the third rotation axis 321 and the fourth rotation axis 322 which are parallel to each other; wherein the third serpentine element 303 in the second serpentine component 32 rotates around the third rotation axis 321, and the fourth serpentine element 304 rotates around the fourth rotation axis 322; the fourth serpentine component 37 can rotate around the seventh rotation axis 371 and the eighth rotation axis 372 which are parallel to each other; wherein the fourth serpentine element 304 can rotate around the seventh rotation axis 371, and the fifth serpentine element 305 can rotate around the eighth rotation axis 372. The first rotation axis 311, the second rotation axis 312, the third rotation axis 321 and the fourth rotation axis 322 are parallel and all located in the first plane 34; the fifth rotation axis 361, the sixth rotation axis 362, the seventh rotation axis 371 and the eighth rotation axis 372 are parallel and all located in the second plane 35. In this application, this arrangement of the serpentine components is referred to as an "ABBA" arrangement. Among them, a first supporting structure may be provided between the first serpentine element 301 and the second serpentine element 302, and the distance between the first rotation axis 311 and the second rotation axis 312 is always kept constant by providing the first supporting structure; a second supporting structure may be provided between the second serpentine element 302 and the third serpentine element 303, and the distance between the fifth rotation axis 361 and the sixth rotation axis 362 is always kept constant by providing the second supporting structure; a third supporting structure may be provided between the third serpentine element 303 and the fourth serpentine element 304, and the distance between the seventh rotation axis 371 and the eighth rotation axis 372 is always kept constant by providing the third supporting structure; a fourth supporting structure may be provided between the fourth serpentine element 304 and the fifth serpentine element 305, and the distance between the third rotation axis 321 and the fourth rotation axis 322 is always kept constant by providing the fourth supporting structure.

[0137] In this embodiment, the flexible arm 30 further includes a first restraining member 331, a second restraining member 332, a third restraining member 333 and a fourth restraining member 334. Fig. 20As shown, the flexible arm 30 has a first projection on the second plane 35, and in the first projection, the first constraint 331 and the second constraint 332 are symmetrical about the first plane 34; in the first projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along the direction parallel to the axis of the flexible arm 30, and in the first projection, the first constraint 331 and the second constraint 332 cross in the second snake bone element 302 or the fourth snake bone element 304. Fig. 20 Only the first constraint member 331 and the second constraint member 332 are shown to cross in the second snake element 302 in the first projection, and the first constraint member 331 and the second constraint member 332 are not shown to cross in the fourth snake element 304 in the first projection.

[0138] like Fig.21 As shown, the flexible arm 30 has a second projection on the first plane 34, and in the second projection, the third constraint member 333 and the fourth constraint member 334 are symmetrical about the second plane 35. In the second projection, the third constraint member 333 and the fourth constraint member 334 are arranged in the first snake bone component 31, the second snake bone component 32, the third snake bone component 36 and the fourth snake bone component 37 along a direction parallel to the axis of the flexible arm 30. In the second projection, the third constraint member 333 and the fourth constraint member 334 cross in the third snake bone element 303.

[0139] In this embodiment, the principle of the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 restraining the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent is the same as that of the above-mentioned embodiment 4, and will not be repeated here.

[0140] The following is a detailed description of the insertion method of the first restraining member 331, the second restraining member 332, the third restraining member 333 and the fourth restraining member 334 in the flexible arm 30; wherein, according to different intersection positions, the first restraining member 331, the second restraining member 332, the third restraining member 333 and the fourth restraining member 334 can have the following insertion methods:

[0141] (1) The first restraining member 331 passes through the eighth hole 383 of the first serpentine element 301, the eighth hole 383 and the seventh hole 384 of the second serpentine element 302, the seventh hole 384 of the third serpentine element 303, the seventh hole 384 of the fourth serpentine element 304 and the seventh hole 384 of the fifth serpentine element 305 in sequence; the second restraining member 332 passes through the seventh hole 384 of the first serpentine element 301, the seventh hole 384 and the eighth hole 383 of the second serpentine element 302, the eighth hole 383 of the third serpentine element 303, the eighth hole 383 of the fourth serpentine element 304 and the eighth hole 383 of the fifth serpentine element 305 in sequence; The three restraining members 333 sequentially pass through the fifth hole 381 of the first snake bone element 301, the fifth hole 381 on the second snake bone element 302, the fifth hole 381 and the sixth hole 382 on the third snake bone element 303, the sixth hole 382 on the fourth snake bone element 304, and the sixth hole 382 on the fifth snake bone element 305; the fourth restraining member 334 sequentially passes through the sixth hole 382 on the first snake bone element 301, the sixth hole 382 on the second snake bone element 302, the sixth hole 382 and the fifth hole 381 on the third snake bone element 303, the fifth hole 381 on the fourth snake bone element 304, and the fifth hole 381 on the fifth snake bone element 305. When the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 are arranged in the above manner, the first restraint member 331 and the second restraint member 332 cross in the second snake bone element 302 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the third snake bone element 303 in the second projection.

[0142] (2) The first restraining member 331 sequentially passes through the eighth hole 383 of the first serpentine element 301, the eighth hole 383 of the second serpentine element 302, the eighth hole 383 of the third serpentine element 303, the eighth hole 383 and the seventh hole 384 of the fourth serpentine element 304, and the seventh hole 384 of the fifth serpentine element 305; the second restraining member 332 sequentially passes through the seventh hole 384 of the first serpentine element 301, the seventh hole 384 of the second serpentine element 302, the seventh hole 384 of the third serpentine element 303, the seventh hole 384 and the eighth hole 383 of the fourth serpentine element 304, and the eighth hole 383 of the fifth serpentine element 305; The three restraining members 333 sequentially pass through the fifth hole 381 of the first snake bone element 301, the fifth hole 381 on the second snake bone element 302, the fifth hole 381 and the sixth hole 382 on the third snake bone element 303, the sixth hole 382 on the fourth snake bone element 304, and the sixth hole 382 on the fifth snake bone element 305; the fourth restraining member 334 sequentially passes through the sixth hole 382 on the first snake bone element 301, the sixth hole 382 on the second snake bone element 302, the sixth hole 382 and the fifth hole 381 on the third snake bone element 303, the fifth hole 381 on the fourth snake bone element 304, and the fifth hole 381 on the fifth snake bone element 305. When the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 are arranged in the above manner, the first restraint member 331 and the second restraint member 332 cross in the fourth snake bone element 304 in the first projection, and the third restraint member 333 and the fourth restraint member 334 cross in the third snake bone element 303 in the second projection.

[0143] Embodiment six:

[0144] In this embodiment, the flexible arm 30 includes a first snake bone component 31, a second snake bone component 32, a third snake bone component 36 and a fourth snake bone component 37. Figure 4 As shown, the above four snake bone components are arranged in an "ABAB" style. In this embodiment, the flexible arm 30 also includes a first restraining member 331, a second restraining member 332, a third restraining member 333 and a fourth restraining member 334; Fig. 22 As shown, the flexible arm 30 has a first projection on the second plane 35, and in the first projection, the first constraint 331 and the second constraint 332 are symmetrical about the first plane 34; in the first projection, the first constraint 331 and the second constraint 332 are arranged in the first snake bone component 31, the second snake bone component 32 and the fourth snake bone component 37 along a direction parallel to the axis of the flexible arm 30, and in the first projection, the first constraint 331 and the second constraint 332 cross in the third snake bone component 36.

[0145] like Fig.23As shown, the flexible arm 30 has a second projection on the first plane 34, and in the second projection, the third constraint member 333 and the fourth constraint member 334 are symmetrical about the second plane 35. In the second projection, the third constraint member 333 and the fourth constraint member 334 are arranged in the first snake bone component 31, the third snake bone component 36 and the fourth snake bone component 37 along the direction parallel to the axis of the flexible arm 30, and in the second projection, the third constraint member 333 and the fourth constraint member 334 cross in the second snake bone component 32.

[0146] In this embodiment, the principle of the first restraint member 331, the second restraint member 332, the third restraint member 333 and the fourth restraint member 334 restraining the S-shaped deformation caused by the lateral movement of each snake bone component in the flexible arm 30 when the flexible arm 30 is bent is the same as that of the above-mentioned embodiment 4, and will not be repeated here.

[0147] The following describes in detail the arrangement of the first restraining member 331, the second restraining member 332, the third restraining member 333 and the fourth restraining member 334 in the flexible arm 30:

[0148] like Fig.24 As shown, the first restraining member 331 sequentially passes through the eighth hole 383 on the first serpentine element 301, the eighth hole 383 on the second serpentine element 302, the seventh hole 384 on the third serpentine element 303, the seventh hole 384 on the fourth serpentine element 304 and the seventh hole 384 on the fifth serpentine element 305; the second restraining member 332 sequentially passes through the seventh hole 384 on the first serpentine element 301, the seventh hole 384 on the second serpentine element 302, the eighth hole 383 on the third serpentine element 303, the eighth hole 383 on the fourth serpentine element 304 and the eighth hole 384 on the fifth serpentine element 305 3; the third restraining member 333 passes through the fifth hole 381 on the first serpentine element 301, the fifth hole 381 on the second serpentine element 302, the fifth hole 381 on the third serpentine element 303, the sixth hole 382 on the fourth serpentine element 304 and the sixth hole 382 on the fifth serpentine element 305 in sequence; the fourth restraining member 334 passes through the sixth hole 382 on the first serpentine element 301, the sixth hole 382 on the second serpentine element 302, the sixth hole 382 on the third serpentine element 303, the fifth hole 381 on the fourth serpentine element 304 and the fifth hole 381 on the fifth serpentine element 305 in sequence. When the first constraint member 331, the second constraint member 332, the third constraint member 333 and the fourth constraint member 334 are inserted into the flexible arm 30 in the above manner, the first constraint member 331 and the second constraint member 332 cross in the third snake bone component 36 in the first projection; the third constraint member 333 and the fourth constraint member 334 cross in the second snake bone component 32 in the second projection.

[0149] Embodiment seven:

[0150] It can be seen from the above embodiments that when constraining the S-shaped deformation of each snake bone component when the flexible arm 30 is bent, the two elements in each snake bone component need to always maintain symmetrical rotation when rotating. This embodiment describes in detail the basic principle of symmetrical rotation:

[0151] like Fig.25 As shown, the target snake bone assembly 50 includes a first target snake bone component 51 and a second target snake bone component 52. The first target snake bone component 51 can rotate around the ninth rotation axis 511, and the second target snake bone component 52 can rotate around the tenth rotation axis 521. During the operation, under the action of the driving member, the first target snake bone component 51 will rotate around the ninth rotation axis 511, and the second target snake bone component 52 will rotate around the tenth rotation axis 521;

[0152] like Fig.25 As shown, when the first target snake-bone element 51 and the second target snake-bone element 52 are rotated to any posture, the extension lines of the first snake-bone element 301 and the second snake-bone element 302 will intersect at point M; the midpoint of the perpendicular line between the ninth rotation axis 511 and the tenth rotation axis 521 is point N, and point M and point N are connected to form a straight line MN, the first target snake-bone element 51 and the straight line MN form a first angle J1, and the second target snake-bone element 52 and the straight line MN form a second angle J2, and the angles of J1 and J2 are always equal. When the above angles are always equal, the first target snake-bone element 51 and the second target snake-bone element 52 can always maintain symmetrical rotation during rotation.

[0153] The components in the first snake assembly 31 , the second snake assembly 32 , the third snake assembly 36 and the fourth snake assembly 37 in the above embodiment are all symmetrically rotated in the above manner.

[0154] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A flexible arm, characterized in that: The flexible arm comprises: A first snake bone component and a second snake bone component, wherein the first snake bone component can rotate around a first rotation axis and a second rotation axis which are parallel to each other, and the second snake bone component can rotate around a third rotation axis and a fourth rotation axis which are parallel to each other, the second rotation axis is parallel to the third rotation axis, and the first rotation axis, the second rotation axis, the third rotation axis and the fourth rotation axis are all located in a first plane; the distance between the first rotation axis and the second rotation axis is constant, and the distance between the third rotation axis and the fourth rotation axis is constant; A first restraint member and a second restraint member, a second plane is orthogonal to the first plane, the flexible arm has a first projection on the second plane, in the first projection, the first restraint member and the second restraint member are symmetrical about the first plane, are penetrated in the first snake bone component and the second snake bone component along a direction parallel to the axis of the flexible arm, and cross between the first snake bone component and the second snake bone component.

2. The flexible arm according to claim 1, characterized in that: The flexible arm further comprises a third snake bone component and a fourth snake bone component, the third snake bone component can rotate around a fifth rotation axis and a sixth rotation axis which are parallel to each other, the fourth snake bone component can rotate around a seventh rotation axis and an eighth rotation axis which are parallel to each other, the sixth rotation axis is parallel to the seventh rotation axis, and the fifth rotation axis, the sixth rotation axis, the seventh rotation axis and the eighth rotation axis are all located in the second plane; the distance between the fifth rotation axis and the sixth rotation axis is constant, and the distance between the seventh rotation axis and the eighth rotation axis is constant; The flexible arm comprises a first snake bone element, a second snake bone element, a third snake bone element, a fourth snake bone element and a fifth snake bone element arranged in sequence, the first snake bone element and the second snake bone element constitute the first snake bone assembly, the second snake bone element and the third snake bone element constitute the third snake bone assembly, the third snake bone element and the fourth snake bone element constitute the second snake bone assembly, and the fourth snake bone element and the fifth snake bone element constitute the fourth snake bone assembly; In the first projection, the first constraint member and the second constraint member are arranged in the third snake bone component and the fourth snake bone component in a direction parallel to the axis of the flexible arm, and cross in the second snake bone component or the third snake bone component; The flexible arm has a second projection on the first plane, in which the first constraint member and the second constraint member are symmetrical about the second plane, and in the second projection, the first constraint member and the second constraint member are inserted into the first snake bone component, the second snake bone component, the third snake bone component and the fourth snake bone component along a direction parallel to the axis of the flexible arm, and cross in the third snake bone component or the fourth snake bone component.

3. The flexible arm according to claim 2, characterized in that: The first snake bone element and the second snake bone element constitute the first snake bone assembly, the second snake bone element and the third snake bone element constitute the third snake bone assembly, the third snake bone element and the fourth snake bone element constitute the fourth snake bone assembly, and the fourth snake bone element and the fifth snake bone element constitute the second snake bone assembly; In the first projection, the first constraint and the second constraint cross in the second snake element or the fourth snake element; In the second projection, the first constraint and the second constraint cross within the third snake element.

4. The flexible arm according to claim 2, characterized in that: Each snake bone element is provided with a first hole, a second hole, a third hole and a fourth hole, the first hole and the second hole are located on one side of the first plane, the third hole and the fourth hole are located on the other side of the first plane, the first hole and the third hole are symmetrical about the first plane, and the second hole and the fourth hole are symmetrical about the first plane; the first holes on all the snake bone elements are coaxially arranged, the second holes on all the snake bone elements are coaxially arranged, the third holes on all the snake bone elements are coaxially arranged, and the fourth holes on all the snake bone elements are coaxially arranged; The first restraining member passes through the first hole on the first snake bone element, the first hole and the third hole on the second snake bone element, the third hole on the third snake bone element, the third hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; The second restraining member passes through the fourth hole on the first snake bone element, the fourth hole and the second hole on the second snake bone element, the second hole on the third snake bone element, the second hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the first hole on the first snake bone element, the first hole on the second snake bone element, the first hole and the third hole on the third snake bone element, the third hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element; The second restraining member passes through the fourth hole on the first snake bone element, the fourth hole on the second snake bone element, the fourth hole and the second hole on the third snake bone element, the second hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the first hole on the first snake bone element, the first hole and the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element; The second restraint passes through the fourth hole on the first snake element, the fourth hole and the second hole on the second snake element, the second hole and the first hole on the third snake element, the first hole on the fourth snake element and the first hole on the fifth snake element in sequence.

5. The flexible arm according to claim 4, characterized in that: The first restraining member passes through the third hole on the first snake bone element, the third hole and the second hole on the second snake bone element, the second hole on the third snake bone element, the second hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; The second restraining member passes through the second hole on the first snake bone element, the second hole and the third hole on the second snake bone element, the third hole on the third snake bone element, the third hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the third hole on the first snake bone element, the third hole on the second snake bone element, the third hole and the second hole on the third snake bone element, the second hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element; The second restraining member passes through the second hole on the first snake bone element, the second hole on the second snake bone element, the second hole and the third hole on the third snake bone element, the third hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the third hole on the first snake bone element, the third hole and the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole on the fourth snake bone element and the first hole on the fifth snake bone element; The second restraint passes through the second hole on the first snake element, the second hole and the third hole on the second snake element, the third hole and the fourth hole on the third snake element, the fourth hole on the fourth snake element and the fourth hole on the fifth snake element in sequence.

6. The flexible arm according to claim 4, characterized in that: The first restraining member passes through the first hole on the first snake bone element, the first hole and the fourth hole on the second snake bone element, the fourth hole on the third snake bone element, the fourth hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; The second restraining member passes through the fourth hole on the first snake bone element, the fourth hole and the first hole on the second snake bone element, the first hole on the third snake bone element, the first hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the first hole on the first snake bone element, the first hole on the second snake bone element, the first hole and the fourth hole on the third snake bone element, the fourth hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element; The second restraining member passes through the fourth hole on the first snake bone element, the fourth hole on the second snake bone element, the fourth hole and the first hole on the third snake bone element, the first hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the first hole on the first snake bone element, the first hole and the fourth hole on the second snake bone element, the fourth hole and the first hole on the third snake bone element, the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element; The second restraint member sequentially passes through the fourth hole on the first snake bone element, the fourth hole and the first hole on the second snake bone element, the first hole and the fourth hole on the third snake bone element, the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element.

7. The flexible arm according to claim 3, characterized in that: Each snake bone element is provided with a first hole, a second hole, a third hole and a fourth hole, the first hole and the second hole are located on one side of the first plane, the third hole and the fourth hole are located on the other side of the first plane, the first hole and the third hole are symmetrical about the first plane, and the second hole and the fourth hole are symmetrical about the first plane; the first holes on all the snake bone elements are coaxially arranged, the second holes on all the snake bone elements are coaxially arranged, the third holes on all the snake bone elements are coaxially arranged, and the fourth holes on all the snake bone elements are coaxially arranged; The first restraining member sequentially passes through the first hole on the first snake bone element, the first hole and the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element; The second restraining member passes through the fourth hole on the first snake bone element, the fourth hole and the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the third hole on the first snake bone element, the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole and the second hole on the fourth snake bone element, and the second hole on the fifth snake bone element; The second restraint passes through the second hole on the first snake bone element, the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole and the third hole on the fourth snake bone element, and the third hole on the fifth snake bone element in sequence.

8. The flexible arm according to claim 7, characterized in that: The first restraining member sequentially passes through the third hole on the first snake bone element, the third hole and the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element; The second restraining member passes through the second hole on the first snake bone element, the second hole and the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the third hole on the first snake bone element, the third hole on the second snake bone element, the third hole and the fourth hole on the third snake bone element, the fourth hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element; The second restraint member sequentially passes through the second hole on the first snake bone element, the second hole on the second snake bone element, the second hole and the first hole on the third snake bone element, the first hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element.

9. The flexible arm according to claim 7, characterized in that: The first restraining member passes through the first hole on the first snake bone element, the first hole on the second snake bone element, the first hole and the fourth hole on the third snake bone element, the fourth hole and the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element in sequence; The second restraining member passes through the fourth hole on the first snake bone element, the fourth hole on the second snake bone element, the fourth hole and the first hole on the third snake bone element, the first hole and the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the first hole on the first snake bone element, the first hole and the fourth hole on the second snake bone element, the fourth hole and the first hole on the third snake bone element, the first hole on the fourth snake bone element, and the first hole on the fifth snake bone element; The second restraint member sequentially passes through the fourth hole on the first snake bone element, the fourth hole and the first hole on the second snake bone element, the first hole and the fourth hole on the third snake bone element, the fourth hole on the fourth snake bone element, and the fourth hole on the fifth snake bone element.

10. The flexible arm according to claim 1, characterized in that The flexible arm further comprises a third snake bone component and a fourth snake bone component, the third snake bone component can rotate around a fifth rotation axis and a sixth rotation axis which are parallel to each other, the fourth snake bone component can rotate around a seventh rotation axis and an eighth rotation axis which are parallel to each other, the sixth rotation axis is parallel to the seventh rotation axis, and the fifth rotation axis, the sixth rotation axis, the seventh rotation axis and the eighth rotation axis are all located in the second plane; the distance between the fifth rotation axis and the sixth rotation axis is constant, and the distance between the seventh rotation axis and the eighth rotation axis is constant; The flexible arm comprises a first snake bone element, a second snake bone element, a third snake bone element, a fourth snake bone element and a fifth snake bone element arranged in sequence, the first snake bone element and the second snake bone element constitute the first snake bone assembly, the second snake bone element and the third snake bone element constitute the third snake bone assembly, the third snake bone element and the fourth snake bone element constitute the second snake bone assembly, and the fourth snake bone element and the fifth snake bone element constitute the fourth snake bone assembly; In the first projection, the first constraint member and the second constraint member are arranged in the third snake bone component and the fourth snake bone component in a direction parallel to the axis of the flexible arm, and cross in the second snake bone component or the third snake bone component; The flexible arm also includes a third constraint member and a fourth constraint member. The flexible arm has a second projection on the first plane. In the second projection, the third constraint member and the fourth constraint member are symmetrical about the second plane. In the second projection, the third constraint member and the fourth constraint member are arranged in the first snake bone component, the second snake bone component, the third snake bone component and the fourth snake bone component in a direction parallel to the axis of the flexible arm, and cross in the third snake bone component or the fourth snake bone component.

11. The flexible arm according to claim 10, characterized in that The first snake bone element and the second snake bone element constitute the first snake bone assembly, the second snake bone element and the third snake bone element constitute the third snake bone assembly, the third snake bone element and the fourth snake bone element constitute the fourth snake bone assembly, and the fourth snake bone element and the fifth snake bone element constitute the second snake bone assembly; In the first projection, the first constraint and the second constraint cross in the second snake element or the fourth snake element; In the second projection, the third constraint and the fourth constraint cross within the third snake element.

12. The flexible arm according to claim 10, characterized in that Each snake bone element is provided with a fifth hole, a sixth hole, a seventh hole and an eighth hole, the fifth hole and the sixth hole are located on the first plane and are symmetrically distributed about the axis of the flexible arm, the seventh hole and the eighth hole are located on the second plane and are symmetrically distributed about the axis of the flexible arm; the fifth holes on all the snake bone elements are coaxially arranged, the sixth holes on all the snake bone elements are coaxially arranged, the seventh holes on all the snake bone elements are coaxially arranged, and the eighth holes on all the snake bone elements are coaxially arranged; The first restraining member sequentially passes through the eighth hole of the first snake bone element, the eighth hole and the seventh hole of the second snake bone element, the seventh hole of the third snake bone element, the seventh hole of the fourth snake bone element and the seventh hole of the fifth snake bone element; The second restraining member sequentially passes through the seventh hole on the first snake bone element, the seventh hole and the eighth hole on the second snake bone element, the eighth hole on the third snake bone element, the eighth hole on the fourth snake bone element and the eighth hole on the fifth snake bone element; The third restraining member sequentially passes through the fifth hole of the first serpentine element, the fifth hole of the second serpentine element, the fifth hole and the sixth hole of the third serpentine element, the sixth hole of the fourth serpentine element and the sixth hole of the fifth serpentine element; The fourth restraint member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole and the fifth hole on the third snake bone element, the fifth hole on the fourth snake bone element and the fifth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the eighth hole of the first snake bone element, the eighth hole of the second snake bone element, the eighth hole and the seventh hole of the third snake bone element, the seventh hole of the fourth snake bone element and the seventh hole of the fifth snake bone element; The second restraining member sequentially passes through the seventh hole on the first snake bone element, the seventh hole on the second snake bone element, the seventh hole and the eighth hole on the third snake bone element, the eighth hole on the fourth snake bone element and the eighth hole on the fifth snake bone element; The third restraining member passes through the fifth hole of the first snake bone element, the fifth hole of the second snake bone element, the fifth hole of the third snake bone element, the fifth hole and the sixth hole of the fourth snake bone element, and the sixth hole of the fifth snake bone element in sequence; The fourth restraining member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole on the third snake bone element, the sixth hole and the fifth hole on the fourth snake bone element, and the fifth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the eighth hole of the first snake bone element, the eighth hole and the seventh hole of the second snake bone element, the seventh hole of the third snake bone element, the seventh hole of the fourth snake bone element and the seventh hole of the fifth snake bone element; The second restraining member sequentially passes through the seventh hole on the first snake bone element, the seventh hole and the eighth hole on the second snake bone element, the eighth hole on the third snake bone element, the eighth hole on the fourth snake bone element and the eighth hole on the fifth snake bone element; The third restraining member passes through the fifth hole of the first snake bone element, the fifth hole of the second snake bone element, the fifth hole of the third snake bone element, the fifth hole and the sixth hole of the fourth snake bone element, and the sixth hole of the fifth snake bone element in sequence; The fourth restraint member sequentially passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole on the third snake bone element, the sixth hole and the fifth hole on the fourth snake bone element, and the fifth hole on the fifth snake bone element.

13. The flexible arm according to claim 11, characterized in that Each snake bone element is provided with a fifth hole, a sixth hole, a seventh hole and an eighth hole, the fifth hole and the sixth hole are located on the first plane and are symmetrically distributed about the axis of the flexible arm, the seventh hole and the eighth hole are located on the second plane and are symmetrically distributed about the axis of the flexible arm; the fifth holes on all the snake bone elements are coaxially arranged, the sixth holes on all the snake bone elements are coaxially arranged, the seventh holes on all the snake bone elements are coaxially arranged, and the eighth holes on all the snake bone elements are coaxially arranged; The first restraining member sequentially passes through the eighth hole of the first snake bone element, the eighth hole and the seventh hole of the second snake bone element, the seventh hole of the third snake bone element, the seventh hole of the fourth snake bone element and the seventh hole of the fifth snake bone element; The second restraining member sequentially passes through the seventh hole on the first snake bone element, the seventh hole and the eighth hole on the second snake bone element, the eighth hole on the third snake bone element, the eighth hole on the fourth snake bone element and the eighth hole on the fifth snake bone element; The third restraining member sequentially passes through the fifth hole of the first serpentine element, the fifth hole of the second serpentine element, the fifth hole and the sixth hole of the third serpentine element, the sixth hole of the fourth serpentine element and the sixth hole of the fifth serpentine element; The fourth restraint member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole and the fifth hole on the third snake bone element, the fifth hole on the fourth snake bone element and the fifth hole on the fifth snake bone element in sequence; Alternatively, the first restraining member sequentially passes through the eighth hole of the first snake bone element, the eighth hole of the second snake bone element, the eighth hole of the third snake bone element, the eighth hole and the seventh hole of the fourth snake bone element, and the seventh hole of the fifth snake bone element; The second restraining member sequentially passes through the seventh hole on the first snake bone element, the seventh hole on the second snake bone element, the seventh hole on the third snake bone element, the seventh hole and the eighth hole of the fourth snake bone element, and the eighth hole of the fifth snake bone element; The third restraining member sequentially passes through the fifth hole of the first serpentine element, the fifth hole of the second serpentine element, the fifth hole and the sixth hole of the third serpentine element, the sixth hole of the fourth serpentine element and the sixth hole of the fifth serpentine element; The fourth restraint member sequentially passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole and the fifth hole on the third snake bone element, the fifth hole on the fourth snake bone element and the fifth hole on the fifth snake bone element.

14. The flexible arm according to claim 10, characterized in that In the first projection, the first restraining member and the second restraining member are arranged in the first snake bone component, the second snake bone component and the fourth snake bone component in a direction parallel to the axis of the flexible arm, and cross in the third snake bone component; In the second projection, the third restraint member and the fourth restraint member are arranged in the first snake bone component, the third snake bone component and the fourth snake bone component in a direction parallel to the axis of the flexible arm, and cross in the second snake bone component.

15. The flexible arm according to claim 14, characterized in that Each snake bone element is provided with a fifth hole, a sixth hole, a seventh hole and an eighth hole, the fifth hole and the sixth hole are located on the first plane and are symmetrically distributed about the axis of the flexible arm, the seventh hole and the eighth hole are located on the second plane and are symmetrically distributed about the axis of the flexible arm; the fifth holes on all the snake bone elements are coaxially arranged, the sixth holes on all the snake bone elements are coaxially arranged, the seventh holes on all the snake bone elements are coaxially arranged, and the eighth holes on all the snake bone elements are coaxially arranged; The first restraining member passes through the eighth hole on the first snake bone element, the eighth hole on the second snake bone element, the seventh hole on the third snake bone element, the seventh hole on the fourth snake bone element and the seventh hole on the fifth snake bone element in sequence; The second restraining member passes through the seventh hole on the first snake bone element, the seventh hole on the second snake bone element, the eighth hole on the third snake bone element, the eighth hole on the fourth snake bone element and the eighth hole on the fifth snake bone element in sequence; The third restraining member passes through the fifth hole on the first snake bone element, the fifth hole on the second snake bone element, the fifth hole on the third snake bone element, the sixth hole on the fourth snake bone element and the sixth hole on the fifth snake bone element in sequence; The fourth restraint member passes through the sixth hole on the first snake bone element, the sixth hole on the second snake bone element, the sixth hole on the third snake bone element, the fifth hole on the fourth snake bone element and the fifth hole on the fifth snake bone element in sequence.

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