CN111618906B

CN111618906B - Flexible wrist structure, bionic hand structure and robot

Info

Publication number: CN111618906B
Application number: CN202010582635.2A
Authority: CN
Inventors: 程二亭
Original assignee: Jingdong Technology Information Technology Co Ltd
Current assignee: Jingdong Technology Information Technology Co Ltd
Priority date: 2020-06-23
Filing date: 2020-06-23
Publication date: 2022-04-12
Anticipated expiration: 2040-06-23
Also published as: CN111618906A

Abstract

The invention relates to the technical field of robots, in particular to a flexible wrist structure, a bionic hand structure and a robot. The flexible wrist structure comprises a body, a spherical hinge and a first cylinder, wherein the body is provided with a first end face, and a plurality of first holes are formed in the first end face; the ball hinge comprises a ball head which is rotatably connected in the body and a ball pin which extends out of the first end surface; the first cylinder slides and is limited in the first hole, the first cylinder is connected with the body through the first elastic piece, and one end of the first cylinder, which extends out of the first end face, is pressed to enable the first cylinder to overcome the elastic restoring force of the first elastic piece and slide along the first hole. When it was applied to the bionic hand structure, the palm subassembly can be 360 degrees under the effect of ball pivot and sway the rotation, can make the palm subassembly finally be in vertical state under first cylinder and first elastic component effect to can sway the in-process at the palm subassembly and provide the buffering, when expanding the degree of freedom of bionic hand structure executive task in-process, strengthen the stability of bionic hand structure at the swing in-process.

Description

Flexible wrist structure, bionic hand structure and robot

Technical Field

The invention relates to the technical field of robots, in particular to a flexible wrist structure, a bionic hand structure and a robot.

Background

The bionic hand structure is a bionic machine which is driven by power to finish the simulation of biological shapes, structures and actions, has a self-adaptive grabbing function, can meet the grabbing requirements of various objects, meets the requirements of reducing complex sensing and real-time control when used in different occasions, improves the grabbing stability and accuracy, and can be widely applied to industrial, agricultural and service robots or used as a dummy hand for disabled people. However, the conventional bionic hand wrists are of rigid structures, which are very unfavorable for the completion of tasks by the bionic hand, and the rigid wrists enable the bionic hand to lose the freedom degree in the swinging direction, so that the functions of the bionic hand are severely restricted.

Disclosure of Invention

The application aims to provide a flexible wrist structure to solve the problems that the freedom of movement of the existing rigid wrist structure is limited and the function is restricted.

Technical scheme (I)

To achieve the above object, a first aspect of the present invention provides a flexible wrist structure comprising:

the body is provided with a first end face, and a plurality of first holes are formed in the first end face;

the spherical hinge comprises a ball head which is rotatably connected in the body and a ball pin which extends out of the first end surface;

the first cylinder is limited in the first hole in a sliding mode, the first cylinder is connected with the body through a first elastic piece, and one end, extending out of the first end face, of the first cylinder is pressed to enable the first cylinder to overcome elastic resetting force of the first elastic piece and slide along the first hole.

Further, the first elastic element is a spring sleeved on the first cylinder.

Furthermore, a first bump is formed on the inner wall of the first hole, a second bump is formed on the first column, one end of the spring is connected to the first bump, and the other end of the spring is connected to the second bump.

Furthermore, flexible wrist structure still includes first screw, first cylinder stretches into be provided with the screw hole on the terminal surface of the one end in first hole, first screw with the screw hole matches the spiro union, the nut of screw is located first lug deviates from one side of first terminal surface.

Further, the first holes are arranged in a circular array on the first end face.

Furthermore, the body comprises a first flange and a second flange which are connected with each other, a concave hemispherical surface is formed on each of the first flange and the second flange, and after the first flange and the second flange are assembled, the two hemispherical surfaces surround to form a cavity matched with the ball head.

Further, the first hole is a through hole penetrating through the first flange.

Furthermore, a first limiting plane perpendicular to the ball pin is formed at one end, away from the ball pin, of the ball head, a locking piece is arranged in the body, a second limiting plane is arranged on the locking piece, and the locking piece has a locking state and an unlocking state; in the locked state, the first limiting plane is attached to the second limiting plane, in the unlocked state, the first limiting plane is separated from the second limiting plane, and the second limiting plane is located outside the moving range of the ball head.

Further, the latch fitting is the locking lever, the middle section of locking lever forms to one side protrusion the spacing plane of second, this internal slide that is provided with, the locking lever slide set up in the slide.

Further, flexible wrist structure still includes the second cylinder and second elastic component, the second hole has been seted up on the body, the second cylinder slide spacing in the second is downthehole, the second elastic component set up in the second cylinder with between the body, just the second cylinder is in the butt is in under the elasticity restoring force effect of second elastic component on the latch fitting, be provided with first spacing groove and second spacing groove on the latch fitting under the locking state, the tip of second cylinder spacing in first spacing inslot under the unblock state, the tip of second cylinder spacing in the second spacing inslot.

Further, under the condition that the body comprises a second flange, the body further comprises a third flange connected with the second flange, the slide way is formed by encircling the second flange and the third flange, and the second hole is formed in the second flange.

To achieve the above object, a second aspect of embodiments of the present invention provides a bionic hand structure comprising a palm component and the flexible wrist structure of the first aspect of the invention, the palm component being secured to the ball pin.

To achieve the above object, a second aspect of the embodiments of the present invention provides a robot including the bionic hand structure of the second aspect of the present invention.

(II) beneficial effect:

compared with the prior art, the invention has the following beneficial effects:

the flexible wrist structure comprises a body, a spherical hinge and a plurality of first cylinders, when the flexible wrist structure is applied to a bionic hand structure, a palm component can swing and rotate 360 degrees under the action of the spherical hinge, the palm component can be finally in a vertical state under the action of the first cylinders and the first elastic pieces, and the first cylinders and the first elastic pieces can provide buffer in the swinging and rotating process of the palm component, so that the freedom degree of the bionic hand structure in the task execution process is expanded, and the stability of the bionic hand structure in the swinging process is enhanced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, serve to provide a further understanding of the application and to enable other features, objects, and advantages of the application to be more apparent. The drawings and their description illustrate the embodiments of the invention and do not limit it. In the drawings:

FIG. 1 is a schematic structural diagram of a flexible wrist structure provided in an embodiment of the present application;

FIG. 2 is a first schematic cross-sectional view of a flexible wrist structure provided in an embodiment of the present application;

FIG. 3 is a schematic cross-sectional view II of a flexible wrist structure provided in an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a lock rod provided in an embodiment of the present application; and

fig. 5 is a schematic structural diagram of a bionic hand structure provided in an embodiment of the present application.

In the figure:

1. a body; 101. a first flange; 102. a second flange; 103. a third flange; 2. a first hole; 3. spherical hinge; 301. a ball head; 302. a ball pin; 4. a first column; 5. a first elastic member; 6. a first bump; 7. a second bump; 8. a first screw; 9. a first limit plane; 10. a second limit plane; 11. a lock lever; 12. a slideway; 13. a second cylinder; 14. a second elastic member; 15. a second hole; 16. a first limit groove; 17. a second limit groove; 18. a third bump; 19. a fourth bump; 20. a second screw; 100. a flexible wrist structure; 200. a palm assembly.

Detailed Description

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In this application, the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation.

Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate.

Furthermore, the terms "disposed," "connected," and "secured" are to be construed broadly. For example, "connected" may be a fixed connection, a detachable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 to 4, a flexible wrist structure 100 provided in the embodiment of the present application includes a body 1, a spherical hinge 3, and a first cylinder 4, where the body 1 has a first end surface, and a plurality of first holes 2 are opened on the first end surface; the ball hinge 3 comprises a ball head 301 rotatably connected in the body 1 and a ball pin 302 extending out of the first end face; first cylinder 4 slides and is spacing in first hole 2, first cylinder 4 through first elastic component 5 with body 1 is connected, make after the one end that first cylinder 4 stretches out first terminal surface is compressed first cylinder 4 overcomes the elasticity restoring force of first elastic component 5 is followed first hole 2 slides.

In the above embodiments, the body 1 is the main structure of the flexible wrist structure 100, and the specific shape thereof is not particularly limited, and may be specifically selected according to the requirement, and is preferably a cylindrical structure as shown in fig. 1. The bulb 301 and the body 1 cooperation of ball pivot 3 to realize 360 degrees rotations, the ball round pin 302 of ball pivot 3 is used for being connected with the palm subassembly, preferably adopts threaded connection, can set up the external screw thread on ball round pin 302. Flexible wrist structure includes body 1, ball pivot 3 and a plurality of first cylinder 4, when it is applied to bionic hand structure, the palm subassembly can be 360 degrees under ball pivot 3 effects and sway the rotation, can make the palm subassembly finally be in vertical state under first cylinder 4 and first elastic component 5 effect, and first cylinder 4 and first elastic component 5 can provide the buffering at the palm subassembly in-process that sways the pivoted, when expanding the degree of freedom of bionic hand structure execution task in-process, reinforcing bionic hand structure is at the stability of swing in-process.

In some embodiments, the first elastic member 5 is a spring sleeved on the first cylinder 4. Specifically, as shown in fig. 2, a first protrusion 6 is formed on an inner wall of the first hole 2, a second protrusion 7 is disposed on the first cylinder 4, one end of the spring is connected to the first protrusion 6, and the other end of the spring is connected to the second protrusion 7. The first protrusion 6 may be a plurality of protrusions formed on the inner wall of the first hole 2, or may be an annular protrusion strip formed on the inner wall of the first hole 2, and the first hole 2 at the position of the first protrusion 6 may allow at least a portion of the first cylinder 4 to pass through and reciprocate. The second protrusion 7 may be a plurality of protrusions disposed on the outer wall of the first cylinder 4, or may be an annular protrusion band disposed on the outer wall of the first cylinder 4. Optionally, as shown in the figure, the first column 4 includes a first section and a second section which are coaxially arranged, the diameter of the second section is smaller than that of the first section, the spring is sleeved on the second section, so that a step structure is formed at the joint of the first section and the second section, the first section is the second bump 7, one end of the spring is connected to the end, connected to the first section and the second section, of the spring, that is, the step structure, and the other end of the spring is connected to the first bump 6. In the process of downward movement of the first column body 4, the first lug 6, the second lug 7 and the spring act together to limit the first column body 4.

In some embodiments, in order to limit the upward movement process of the first cylinder 4, as shown in fig. 2, the flexible wrist structure further includes a first screw 8, a threaded hole is provided on an end surface of one end of the first cylinder 4 extending into the first hole 2, the first screw 8 is in threaded connection with the threaded hole in a matching manner, and a nut of the screw is located on a side of the first protruding block 6 away from the first end surface. When the nut is moved to the position of the first projection 6, the upward movement of the first cylinder 4 reaches the limit position, which prevents the first cylinder 4 from coming out of the first hole 2. Furthermore, by screwing or unscrewing the first screw 8, the amount of deformation of the spring and the length of the first cylinder 4 that naturally protrudes through the first hole 2 can be adjusted, and can thus be adjusted to specific requirements.

In some embodiments, as shown in fig. 1, a plurality of the first holes 2 are arranged in a circular array on the first end surface. When the body 1 is a cylindrical structure, the first end face is circular or annular, the first holes 2 are uniformly distributed on the circumference taking the circle center of the first end face as the circle center, and meanwhile, all the first cylinders 4, the first elastic pieces 5 and the first holes 2 are related to the same specification, so that the buffering effect generated by the first cylinders 4 of each cylinder is the same, and the palm components are uniformly distributed on the first end face, so that the palm components mounted on the flexible wrist structure are finally in a vertical state.

In some embodiments, as shown in fig. 3, an end of the ball head 301 facing away from the ball pin 302 is formed with a first limiting plane 9 perpendicular to the ball pin 302, a locking element is disposed in the body 1, and a second limiting plane 10 is disposed on the locking element, and the locking element has a locking state and an unlocking state. In the locked state, the first limiting plane 9 is attached to the second limiting plane 10, and at the moment, the ball head 301 of the spherical hinge 3 is limited by the second limiting plane 10, so that the spherical hinge 3 cannot swing; in the unlocked state, the first limiting plane 9 is separated from the second limiting plane 10, and the second limiting plane 10 is located outside the moving range of the ball head 301, at this time, when the ball pin 302 of the ball hinge 3 receives an external force, the ball head 301 can rotate in the body 1, so that the swing motion of the ball hinge 3 is realized.

In some embodiments, as shown in fig. 4, the latch fitting is locking lever 11, the middle section of locking lever 11 forms to one side protrusion the spacing plane of second 10, be provided with slide 12 in the body 1, locking lever 11 slide set up in slide 12, through the reciprocal slip of locking lever 11 in slide 12 to realize the switching of locking state and unlocking state, preferably, no matter locking lever 11 is in locking state or unlocking state, body 1 is stretched out to at least one end of locking lever 11, thereby can drive locking lever 11 and slide in slide 12 through the tip of pulling or promotion locking lever 11, realize the switching of locking state and unlocking state.

In some embodiments, as shown in fig. 3, the flexible wrist structure further includes a second cylinder 13 and a second elastic element 14, a second hole 15 is formed in the body 1, the second cylinder 13 is slidably limited in the second hole 15, the second elastic element 14 is disposed between the second cylinder 13 and the body 1, the second cylinder 13 abuts against the locking element under the elastic restoring force of the second elastic element 14, and the locking element is provided with a first limiting groove 16 and a second limiting groove 17. In the locked state, the end of the second column 13 is limited in the first limiting groove 16, at this time, the first limiting plane 9 is attached to the second limiting plane 10, the ball head 301 of the ball joint 3 is limited by the second limiting plane 10, and the ball joint 3 cannot swing; in the unlocking state, the end of the second column 13 is limited in the second limiting groove 17, at this time, the first limiting plane 9 is separated from the second limiting plane 10, and the second limiting plane 10 is located outside the moving range of the ball head 301, when the ball pin 302 of the ball hinge 3 is acted by an external force, the ball head 301 can rotate in the body 1, so that the swing motion of the ball hinge 3 is realized. Preferably, the end of the second cylinder 13 is of a conical structure, the first limiting groove 16 and the second limiting groove 17 are conical grooves matched with the end of the second cylinder 13, and the conical structural design has an inclined plane, so that the second cylinder 13 and the conical grooves in the matching state can be conveniently separated when being interfered by external force, and the locking state and the unlocking state can be conveniently switched.

In some embodiments, the second elastic element 14 is a spring sleeved on the second cylinder 13. Specifically, as shown in fig. 3, a third protrusion 18 is formed on an inner wall of the second hole 15, a fourth protrusion 19 is disposed on the second cylinder 13, one end of the spring is connected to the third protrusion 18, and the other end of the spring is connected to the fourth protrusion 19. The third protrusion 18 may be a plurality of protrusions formed on the inner wall of the second hole 15, or may be a ring-shaped protrusion strip formed on the inner wall of the second hole 15, and the second hole 15 at the position of the third protrusion 18 may allow at least a portion of the second cylinder 13 to pass through and reciprocate. The fourth protrusion 19 may be a plurality of protrusions formed on the outer wall of the second cylinder 13, or may be a ring-shaped protrusion strip formed on the outer wall of the second cylinder 13. In the process of moving the second cylinder 13, the third cam 18, the fourth cam 19 and the spring act together to limit the second cylinder 13.

In some embodiments, as shown in fig. 3, the flexible wrist structure further includes a second screw 20, a threaded hole is provided on an end surface of one end of the second cylinder 13 extending into the second hole 15, the second screw 20 is screwed into the threaded hole in a matching manner, and a nut of the screw is located on a side of the third projection 18 facing away from the locking piece. When the nut moves to the position of the third bump 18, the movement of the second post 13 in one direction reaches the limit position, so that the second post 13 can be prevented from being disengaged from the second hole 15, and in addition, the deformation amount of the spring can be adjusted by screwing or unscrewing the second screw 20, so that the connection strength between the second post 13 and the first limiting groove 16 or the second limiting groove 17 can be adjusted according to more specific requirements.

In some embodiments, as shown in fig. 1 to 3, the body 1 includes a first flange 101, a second flange 102, and a third flange 103 that are connected to each other, concave hemispherical surfaces are respectively formed on the first flange 101 and the second flange 102, a through hole is formed in the first flange 101 for the ball pin 302 to pass through, and during the rotation of the ball hinge 3, the size of the through hole should be such that no interference occurs between the ball pin 302 and the first flange 101, and after the first flange 101 and the second flange 102 are assembled, two hemispherical surfaces surround to form a cavity that fits with the ball head 301. So set up can make things convenient for the equipment of ball pivot 3 and body 1, when the equipment, pass through the through-hole on the first flange 101 with ball pin 302 of ball pivot 3 and place some in the hemisphere face on first flange 101 of bulb 301, then with the hemisphere face cladding bulb 301 remaining part of second flange 102, then with first flange 101 and second flange 102 fixed connection, the connected mode between first flange 101 and the second flange 102 does not do specifically restriction, with can realize convenient dismantlement can, including but not limited to joint, spiro union, interference fit etc.. On this basis, the first hole 2 can be opened on the first flange 101, and the first hole 2 is a through hole penetrating through the first flange 101, so that the first cylinder 4, the spring and the first screw 8 can be conveniently assembled, when the first cylinder 4, the spring and the first screw 8 are assembled, the spring is sleeved on the first cylinder 4, then one end of the first cylinder 4 sleeved with the spring is inserted from an opening of the second hole 15 on the first end face, the first cylinder 4 penetrates through the protruding part, and then the first screw 8 is screwed into the first cylinder 4 from the other opening of the first hole 2, so that the assembly is completed.

The end surfaces of the second flange 102 and/or the third flange 103, which are opposite to each other, are provided with grooves, the slide way 12 is formed by the second flange 102 and the third flange 103 in a surrounding manner, for example, only the end surface of the second flange 102 is provided with a groove, so that the groove and the end surface of the third flange 103 form the slide way 12 in a surrounding manner, the arrangement can facilitate the assembly of the lock rod 11 and the body 1, during the assembly, the lock rod 11 is placed in the groove on the second flange 102, then the third flange 103 is fixedly connected with the second flange 102, and the connection mode between the second flange 102 and the third flange 103 is not particularly limited, so as to achieve the convenient disassembly, including but not limited to clamping, screwing, interference fit and the like. On the basis, the second hole 15 can be opened on the second flange 102, and the second hole 15 is a through hole penetrating through the second flange 102, so that the second column 13, the spring and the second screw 20 can be conveniently assembled, when the assembly is carried out, the spring is sleeved on the second column 13, then the end, provided with the spring, of the spring is inserted from the second hole 15 on the end face of the second flange 102 towards the opening on the end face of the third flange 103, the second column 13 penetrates through the protruding part, and then the second screw 20 is screwed into the second column 13 from the other opening of the second hole 15, and the assembly is completed.

The invention also discloses a bionic hand structure. As shown in fig. 5, the bionic hand structure according to the embodiment of the invention includes a palm component 200 and the flexible wrist structure 100 provided in the above embodiment, the palm component 200 is fixed on the ball pin 302, specifically, the ball pin 302 is provided with an external thread, the palm component 200 is provided with an internal thread matching with the external thread, and an end surface of the palm component 200 facing the body 1 abuts on the first cylinder 4. The palm subassembly 200 can be 360 degrees rotations of rocking under the effect of ball pivot 3, can make palm subassembly 200 be in vertical state at last under first cylinder 4 and first elastic component 5 effect to first cylinder 4 and first elastic component 5 can provide the buffering at the palm subassembly in-process of rocking the rotation, when expanding the degree of freedom of imitative hand structure execution task in-process, strengthen the stability of imitative hand structure in the swing in-process.

Since the flexible wrist structure is the specific solution disclosed in the above embodiment, the bionic hand having the flexible wrist structure also has all the technical effects of the above embodiment, and details are not repeated here. The bionic hand according to the above embodiments may further include other necessary components or structures, and the corresponding arrangement positions and connection relationships may refer to the structures of the bionic hand in the prior art, and the connection relationships, operation and working principles of the structures which are not mentioned are known to those skilled in the art and will not be described in detail herein.

The invention also discloses a robot. The robot according to the embodiment of the invention comprises the bionic hand structure provided by the embodiment. Since the bionic hand structure is a specific solution disclosed in the above embodiment, the robot having the bionic hand structure also has all the technical effects of the above embodiment, and details are not repeated here. The robot according to the above embodiment may further include other necessary components or structures, and the corresponding arrangement positions and connection relationships may refer to the structures of the robot in the prior art, and the connection relationships, operation and working principles of the structures that are not described are known to those skilled in the art and will not be described in detail herein.

Some embodiments in this specification are described in a progressive or parallel manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible wrist structure, comprising:

the locking device comprises a body (1) and a locking mechanism, wherein the body (1) is provided with a first end surface, a plurality of first holes (2) are formed in the first end surface, a locking piece is arranged in the body (1), a second limiting plane (10) is arranged on the locking piece, and the locking piece has a locking state and an unlocking state;

the ball hinge (3) comprises a ball head (301) rotatably connected in the body (1) and a ball pin (302) extending out of the first end face, a first limiting plane (9) perpendicular to the ball pin (302) is formed at one end of the ball head (301) departing from the ball pin (302), the first limiting plane (9) is attached to the second limiting plane (10) in the locking state, the first limiting plane (9) is separated from the second limiting plane (10) in the unlocking state, and the second limiting plane (10) is located outside the moving range of the ball head (301);

the first cylinder (4) is limited in the first hole (2) in a sliding mode, the first cylinder (4) is connected with the body (1) through a first elastic piece (5), and one end, extending out of the first end face, of the first cylinder (4) is pressed to enable the first cylinder (4) to overcome elastic resetting force of the first elastic piece (5) and slide along the first hole (2).

2. A flexible wrist structure according to claim 1, characterized in that said first elastic element (5) is a spring fitted over said first cylinder (4).

3. A flexible wrist structure according to claim 2, characterized in that the inner wall of the first hole (2) is formed with a first protrusion (6), the first cylinder (4) is formed with a second protrusion (7), one end of the spring is connected to the first protrusion (6), and the other end of the spring is connected to the second protrusion (7).

4. A flexible wrist structure according to claim 3, further comprising a first screw (8), wherein a threaded hole is provided on an end surface of one end of the first cylinder (4) extending into the first hole (2), the first screw (8) is in threaded engagement with the threaded hole, and a nut of the first screw (8) is located on a side of the second protrusion (7) facing away from the first end surface.

5. A flexible wrist structure according to claim 1, characterized in that a plurality of said first holes (2) are arranged in a circular array on said first end face.

6. The flexible wrist structure according to claim 1, characterized in that the body (1) comprises a first flange (101) and a second flange (102) which are connected with each other, a concave semi-sphere is formed on each of the first flange (101) and the second flange (102), and the two semi-spheres surround to form a cavity matched with the ball head (301) after the first flange (101) and the second flange (102) are assembled.

7. A flexible wrist structure according to claim 6, characterized in that the first hole (2) is a through hole through the first flange (101).

8. The flexible wrist structure according to claim 1, characterized in that the locking element is a locking bar (11), the middle section of the locking bar (11) protrudes to one side to form the second limiting plane (10), a slide (12) is disposed in the body (1), and the locking bar (11) is slidably disposed in the slide (12).

9. Flexible wrist structure according to claim 8, further comprising a second cylinder (13) and a second spring (14), a second hole (15) is formed in the body (1), the second column body (13) is limited in the second hole (15) in a sliding manner, the second elastic piece (14) is arranged between the second cylinder (13) and the body (1), and the second cylinder (13) is abutted against the locking piece under the action of the elastic resetting force of the second elastic piece (14), the locking piece is provided with a first limit groove (16) and a second limit groove (17), in the locking state, the end part of the second cylinder (13) is limited in the first limiting groove (16), in the unlocking state, the end part of the second cylinder (13) is limited in the second limiting groove (17).

10. Flexible wrist structure according to claim 9, characterized in that, in case the body (1) comprises a second flange (102), the body (1) further comprises a third flange (103) connected to the second flange (102), the slideway (12) is enclosed by the second flange (102) and the third flange (103), and the second hole (15) opens in the second flange (102).

11. A biomimetic hand structure, comprising a palm component and a flexible wrist structure according to any of claims 1-10, the palm component being secured to the ball stud (302).

12. A robot comprising the biomimetic hand structure of claim 11.