CN220762683U - Cantilever structure and robot - Google Patents

Abstract

The application discloses a cantilever structure and robot relates to bionic robot technical field. The wrist arm structure comprises a small arm and a bearing plate; the forearm comprises a mounting frame, a first telescopic mechanism and a second telescopic mechanism, wherein the mounting frame comprises a first end and a second end, and the first telescopic mechanism and the second telescopic mechanism are arranged at the first end in parallel and extend to the second end; the bearing plate comprises a first connecting arm, a third connecting arm and a second connecting arm which are sequentially arranged in parallel, wherein the third connecting arm is universally pivoted to the second end, the first connecting arm and one end of the first telescopic mechanism, which is close to the second end, are universally pivoted, and the second connecting arm and one end of the second telescopic mechanism, which is close to the second end, are universally pivoted. The wrist arm structure provided by the application can promote the flexibility of robot palm action.

Description

Cantilever structure and robot

Technical Field

The application relates to the technical field of bionic robots, in particular to a cantilever structure and a robot.

Background

The bionic robot has more and more applications in the fields of medical treatment, manufacturing and the like, and can perform operations such as operation, mechanical manufacturing and the like.

However, the wrist structure of the existing bionic robot can only realize relatively simple up-and-down swing, has relatively weak flexibility, and cannot meet the current production application requirements.

Disclosure of Invention

The application provides a cantilever structure and robot to promote cantilever structure's flexibility.

The application provides a cantilever structure, include:

the small arm comprises a mounting frame, a first telescopic mechanism and a second telescopic mechanism, wherein the mounting frame comprises a first end and a second end, and the first telescopic mechanism and the second telescopic mechanism are arranged at the first end in parallel and extend to the second end;

the bearing plate comprises a first connecting arm, a third connecting arm and a second connecting arm which are sequentially arranged in parallel, wherein the third connecting arm is universally pivoted to the second end, the first connecting arm and one end of the first telescopic mechanism, which is close to the second end, are universally pivoted, and the second connecting arm and one end of the second telescopic mechanism, which is close to the second end, are universally pivoted.

Based on the technical scheme, when the cantilever structure is applied to the robot, the first end of the mounting frame can be connected to the big arm of the robot, and the bearing plate can be used for mounting the palm of the robot. In the action process, the bearing plate can be driven to perform different actions by adjusting the telescopic lengths of the first telescopic mechanism and the second telescopic mechanism. Specifically, when the telescopic lengths of the first telescopic mechanism and the second telescopic mechanism are different, the bearing plate can be driven to drive the palm to swing left and right. When the first telescopic mechanism and the second telescopic mechanism synchronously act, and the telescopic lengths are consistent, the bearing plate can be driven to drive the palm to swing up and down, so that the action of the human palm can be simulated, and the flexibility is improved.

In some possible embodiments, the first telescopic mechanism includes a driving member and a driving rod assembly in driving connection, the driving member is mounted at the first end, and the driving rod assembly extends to the second end and is in universal pivoting connection with the first connecting arm.

In some possible embodiments, the driving member is a motor, and the first telescopic mechanism further includes a screw and an adapter;

the screw rod is rotatably arranged on the mounting frame and is connected with the output end of the driving piece;

the adapter sleeve is arranged on the screw rod and is in threaded fit connection with the screw rod, and one end, far away from the first connecting arm, of the transmission rod assembly is hinged to the adapter.

In some possible embodiments, the drive rod assembly includes a first adapter, a sleeve, a telescoping rod, and a second adapter;

one end of the first adapter is in transmission connection with the output end of the driving piece, and one end of the first adapter, which is far away from the driving piece, is fixedly connected with the sleeve;

one end of the telescopic rod is arranged in the sleeve in a floating mode, and the other end of the telescopic rod is arranged in a telescopic mode relative to one end, away from the first adapter, of the sleeve;

the second adapter is connected to one end of the telescopic rod, which is far away from the first adapter, and one end of the second adapter, which is far away from the telescopic rod, is in universal pin joint with the first connecting arm.

In some possible embodiments, a first flange is arranged on the telescopic rod in a protruding way near one end of the first adapter, and a second flange is arranged on the inner wall of the sleeve, which is far away from one end of the first adapter;

the transmission rod assembly further comprises a first elastic piece and a second elastic piece, the first elastic piece is abutted between the first adapter and the first flange, and the second elastic piece is sleeved on the telescopic rod and abutted between the first flange and the second flange.

In some possible embodiments, a first connecting shaft is connected to an end of the first connecting arm, which is close to the first telescopic mechanism, and the first connecting shaft is universally pivoted with the first telescopic mechanism through a first joint bearing.

In some possible embodiments, the third connecting arm includes two connecting plates opposite to each other at a distance, and a second connecting shaft is connected between the two connecting plates;

one side of the second end, which is far away from the first end, is also connected with an adapter sleeve, the adapter sleeve is sleeved on the second connecting shaft, and a second joint bearing is arranged between the adapter sleeve and the second connecting shaft.

In some possible embodiments, a gasket is sandwiched between the second knuckle bearing and both of the connection plates.

In some possible embodiments, the wrist structure further comprises a support rod connected between the first end and the second end.

In addition, the application also provides a robot, which comprises the wrist structure provided in each embodiment.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 illustrates a perspective view of a wrist structure in some embodiments;

FIG. 2 illustrates a partial structural schematic of a wrist structure in some embodiments;

FIG. 3 illustrates a schematic cross-sectional view of a drive rod assembly in some embodiments;

FIG. 4 is a schematic diagram showing the connection structure of the transmission rod assembly and the bearing plate in some embodiments;

FIG. 5 is a schematic view of a partial cross-sectional structure of a second adapter coupled to a first coupling arm in some embodiments;

fig. 6 shows a schematic view of a partial cross-sectional structure of the connection of the swivel hub to the third connecting arm in some embodiments.

Description of main reference numerals:

1000-cantilever structure;

100-forearm; 110-mounting rack; 1101-first end; 1102-a second end; 111-a first mounting plate portion; 112-a second mounting plate portion; 120-a first telescoping mechanism; 121-a driving member; 122-screw rod; 123-an adapter; 124-drive rod assembly; 1241-first adapter; 1242-sleeve; 12421-a second flange; 1243-telescoping rod; 12431-first flange; 1244-second adapter; 1245-a first elastic member; 1246-a second elastic member; 130-a second telescopic mechanism; 141-a supporting seat; 1411-a connecting ring; 1412-an open structure; 142-an adapter sleeve;

200-bearing plates; 210-a main body plate portion; 220-a first connecting arm; 230-a second connecting arm; 240-a third connecting arm; 241-a connection plate;

310-a first connecting shaft; 320-a first knuckle bearing; 330-a second connecting shaft; 340-a second knuckle bearing; 350-a gasket;

400-supporting rods.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc. indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

As shown in fig. 1, a cartesian coordinate system is established defining a length direction of the cantilever structure 1000 parallel to the direction shown by the x-axis, a width direction of the cantilever structure 1000 parallel to the direction shown by the y-axis, and a height direction of the cantilever structure 1000 parallel to the direction shown by the z-axis. It is to be understood that the above definitions are merely for ease of understanding the relative positional relationship of the various partial structures in the wrist structure 1000 and should not be construed as limiting the present application.

In the embodiment, a cantilever structure 1000 is provided, which can be applied to a robot. It is understood that the wrist structure 1000 may be connected between the forearm and the palm of the robot.

As shown in fig. 1, the wrist structure 1000 may include a forearm 100 and a carrier plate 200.

Forearm 100 may include a mounting bracket 110, a first telescoping mechanism 120, and a second telescoping mechanism 130. Mount 110 may extend along the length of wrist-arm structure 1000, and mount 110 may include a first end 1101 and a second end 1102. Wherein the first end 1101 may be used to connect a large arm of a robot.

The first telescopic mechanism 120 and the second telescopic mechanism 130 may be mounted in parallel to the first end 1101 of the mounting frame 110 and may extend to the second end 1102. It will be appreciated that the telescoping directions of first telescoping mechanism 120 and second telescoping mechanism 130 are each generally parallel to the length direction of wrist structure 1000.

Referring to fig. 4 again, the carrying board 200 may be used for installing a palm of a robot, i.e. providing an installation platform for the palm. In an embodiment, the carrier plate 200 may include a first connecting arm 220, a second connecting arm 230, and a third connecting arm 240 arranged in parallel. The first connecting arm 220, the third connecting arm 240 and the second connecting arm 230 may be sequentially disposed along the width direction of the wrist structure 1000, that is, the first connecting arm 220 and the second connecting arm 230 are disposed on two sides of the third connecting arm 240.

The third connecting arm 240 may be universally pivotally connected to the second end 1102 of the mounting frame 110, that is, the third connecting arm 240 may be capable of multi-directional rotation relative to the mounting frame 110. The first connecting arm 220 may be universally pivoted to an end of the first telescopic mechanism 120 near the second end 1102, i.e. the first connecting arm 220 may also perform multi-directional rotation relative to the first telescopic mechanism 120. The second connecting arm 230 may be universally pivoted to an end of the second telescopic mechanism 130 near the second end 1102, that is, the second connecting arm 230 may perform multi-directional rotation with respect to the second telescopic mechanism 130.

When the wrist structure 1000 is applied to a robot, the first end 1101 of the mounting frame 110 may be connected to a large arm of the robot, and a palm of the robot may be mounted on the carrying plate 200.

When the palm needs to swing around the axis parallel to the height direction of the cantilever structure 1000, the first telescopic mechanism 120 and the second telescopic mechanism 130 can be operated, and the telescopic lengths of the first telescopic mechanism 120 and the second telescopic mechanism 130 are different. For example, the length of the first telescoping mechanism 120 may be made greater than the length of the second telescoping mechanism 130. Therefore, the carrying plate 200 can drive the palm to swing towards the direction approaching the second telescopic mechanism 130. In the use process, the supporting plate 200 can also drive the palm to swing left and right around the axis parallel to the height direction of the cantilever structure 1000 by continuously adjusting the telescopic lengths of the first telescopic mechanism 120 and the second telescopic mechanism 130.

When the palm needs to rotate around the axis parallel to the width direction of the cantilever structure 1000, the first telescopic mechanism 120 and the second telescopic mechanism 130 can be synchronously operated, and the length of the first telescopic mechanism 120 is equal to that of the second telescopic mechanism 130. Therefore, the carrying board 200 can be driven to drive the palm to swing up and down around the axis parallel to the width direction of the cantilever structure 1000.

Therefore, the wrist arm structure 1000 provided by the application can realize left-right swing and up-down swing of the palm of the robot, can simulate the action of the palm of the human body, and has more flexibility.

Further, in the embodiment, the structure of the first telescopic mechanism 120 and the structure of the second telescopic mechanism 130 may be substantially the same, and the detailed description will be given below taking the first telescopic mechanism 120 as an example.

As shown in fig. 1 and 2, the first telescopic mechanism 120 may include a driving member 121, a screw 122, an adapter 123, and a driving rod assembly 124.

In some embodiments, the drive member 121 may be a motor. The driver 121 may be fixedly mounted to the first end 1101 of the mounting bracket 110, and an output shaft of the driver 121 may be disposed toward the second end 1102.

The screw 122 is rotatably mounted on the mounting frame 110. Specifically, the end of the mounting frame 110 near the driving member 121 may be fixedly provided with a supporting seat 141 extending along the length direction of the wrist structure 1000, and the supporting seat 141 may be located at the end of the driving member 121 near the second end 1102. The two ends of the supporting seat 141 are respectively provided with a connecting ring 1411, and the two ends of the screw rod 122 can be rotatably installed on the connecting rings 1411 at the two ends of the supporting seat 141 in a one-to-one correspondence manner through bearings.

In addition, the screw 122 and the driving member 121 may be provided with a decelerator (not shown) so far, and may provide a deceleration function. Thus, the screw 122 can be driven to rotate by the driving member 121. In the embodiment, the outer side of the speed reducer can be sleeved with a protective cover and other structures. Of course, a coupling or other structure may be provided between the output shaft of the speed reducer and the screw 122 to achieve power transmission.

The adapter 123 can be sleeved on the screw rod 122, and the adapter 123 is in threaded fit connection with the screw rod 122. In an embodiment, an opening structure 1412 may be formed on a side of the support base 141 away from the mounting frame 110, and an end of the adapter base 123 away from the screw rod 122 may be disposed through the opening structure 1412 and protrude from a side of the support base 141 away from the mounting frame 110. Meanwhile, two sides of the adapter 123 may be attached to two sidewalls of the opening 1412. Thus, the rotation of the adapter 123 can be restricted by the support base 141.

One end of the driving rod assembly 124 may be hinged to the protruding end of the adapter 123 with respect to the supporting seat 141. And the hinge axis of the transmission rod assembly 124 and the adapter 123 may be parallel to the width direction of the wrist structure 1000. The end of the transmission rod assembly 124 away from the adapter 123 may extend to the second end 1102 and be universally pivotally connected to the first connecting arm 220.

In other embodiments, the driving member 121 may alternatively be an electric push rod. One end of the drive rod assembly 124 may be hinged to the output end of the driving member 121.

Referring again to fig. 3 and 4, in some embodiments, the drive rod assembly 124 may be a dual spring telescoping rod structure that provides a shock absorbing cushion during the drive. Specifically, the drive rod assembly 124 may include a first adapter 1241, a sleeve 1242, a telescoping rod 1243, a second adapter 1244, a first resilient member 1245, and a second resilient member 1246.

One end of the first adaptor 1241 is hinged to one end of the adaptor 123 away from the screw 122. The end of the first adapter 1241 remote from the adapter 123 may be fixedly connected to an end of the sleeve 1242 by a threaded connection. The other end of the sleeve 1242 may extend toward the second end 1102.

In other embodiments, the first adapter 1241 and the sleeve 1242 may be fixedly connected by an interference fit, an adhesive, a screw connection, or a clamping connection.

One end of the telescoping rod 1243 is slidably mounted in a sleeve 1242. The other end of the telescopic rod 1243 is telescopically arranged relative to the end of the sleeve 1242 remote from the first adapter 1241. One end of the second adapter 1244 may be fixedly connected with one end of the telescopic rod 1243, which is far away from the first adapter 1241, in a threaded connection manner. The end of the second adaptor 1244 remote from the telescopic rod 1243 may be universally pivoted with the first connecting arm 220.

In an embodiment, the telescopic rod 1243 is provided with a first flange 12431 protruding from a peripheral side near one end of the first adapter 1241. The inner wall of the end of the sleeve 1242 far away from the first adapter 1241 is provided with a second flange 12421 in a protruding manner, the second flange 12421 can be opposite to the first flange 12431, and one end of the telescopic rod 1243 close to the first flange 12431 can be limited in the sleeve 1242, so that the telescopic rod 1243 is prevented from being separated from the sleeve 1242 at will.

The first elastic member 1245 and the second elastic member 1246 are both disposed in the sleeve 1242. And the first elastic member 1245 can be abutted between the first adapter 1241 and the first flange 12431. The second elastic member 1246 may be sleeved on the circumferential side of the telescopic rod 1243, and the second elastic member 1246 may be abutted between the first flange 12431 and the second flange 12421. In some embodiments, the first elastic member 1245 and the second elastic member 1246 may be springs.

In other embodiments, the first elastic member 1245 and the second elastic member 1246 may be flexible posts, elastic sheets, or the like.

In other embodiments, the driving rod assembly 124 may also be a pneumatic rod or hydraulic rod, which may provide a cushioning effect. Accordingly, both the first elastic member 1245 and the second elastic member 1246 may be replaced with an air source or a hydraulic source.

Of course, in other embodiments, the driving rod assembly 124 may alternatively be a rigid rod structure, so as to achieve the driving effect between the driving member 121 and the first connecting arm 220.

As shown in fig. 1 and 4, the carrier 200 further includes a main body plate portion 210, which may be used as a mounting platform for connecting with a palm. The first connecting arm 220, the second connecting arm 230 and the third connecting arm 240 are all disposed at one end of the main body plate 210 near the forearm 100 in a protruding manner. In some embodiments, the first connecting arm 220, the second connecting arm 230, the third connecting arm 240, and the body plate portion 210 may be a unitary structure.

Referring to fig. 5 again, in the embodiment, the end of the first connecting arm 220 away from the main body plate 210 may be connected with a first connecting shaft 310, and the first connecting shaft 310 may be parallel to the width direction of the wrist arm structure 1000. In addition, the first connection shaft 310 may protrude with respect to a side of the first connection arm 220 near the third connection arm 240.

One end of the second adapter 1244 far away from the telescopic rod 1243 can be sleeved on the first connecting shaft 310, and a first joint bearing 320 is arranged between the second adapter 1244 and the first connecting shaft 310, so that universal pivoting between the first connecting shaft 310 and the second adapter 1244 can be realized. Thus, the first connection arm 220 performs multi-directional rotation with respect to the second adapter 1244. It is appreciated that the outer race of the first knuckle bearing 320 may be fixedly coupled to the second adapter 1244. The inner race of the first knuckle bearing 320 may be fixedly coupled to the first coupling shaft 310.

In addition, the gasket 350 is further interposed between the first knuckle bearing 320 and the first connecting arm 220, so that the first knuckle bearing 320 is prevented from being worn seriously due to direct contact with the first connecting arm 220. Therefore, the service life of the first joint bearing 320 can be prolonged, and the operation accuracy of the wrist structure 1000 can be ensured. Wherein the gasket 350 may be made of a material such as silicone or rubber.

In other embodiments, the end of the first connecting arm 220 away from the main body plate 210 may also be fixedly connected with a ball structure. The end of the second adapter 1244 far away from the telescopic rod 1243 can be provided with a spherical groove matched with the ball structure. The ball structure is rotatably mounted in the spherical groove, so that universal pivoting of the first connecting arm 220 and the second adapter 1244 can be realized.

In the embodiment shown in fig. 1 and 6, the adapter sleeve 142 is further connected to the second end 1102 of the mounting bracket 110. Specifically, the second end 1102 of the mounting bracket 110 may be configured with an inverted L-shaped second mounting plate portion 112, and the second mounting plate portion 112 may be located at a side of the mounting bracket 110 adjacent to the driving member 121. The adapter sleeve 142 may be fixedly connected to a side of the second mounting plate 112 away from the first end 1101 by bolting or bonding.

Referring again to fig. 4, the third connecting arm 240 may include two connecting plates 241 spaced apart from each other. A second connection shaft 330 may be connected between the two connection plates 241. The end of the adapter sleeve 142 away from the second mounting plate 112 may be sleeved on the second connecting shaft 330. And the adapter sleeve 142 and the second connecting shaft 330 are provided with a second knuckle bearing 340. It is understood that the outer ring of the second knuckle bearing 340 may be fixedly connected to the adapter sleeve 142, and the inner ring of the second knuckle bearing 340 may be fixedly connected to the second connecting shaft 330. Accordingly, the third connecting arm 240 may be rotated in multiple directions with respect to the adapter sleeve 142. That is, the universal pivoting of the third connecting arm 240 and the mounting frame 110 can be realized.

In addition, the two sides of the second joint bearing 340 are both provided with the gaskets 350, that is, the gaskets 350 are sandwiched between the two connecting plates 241 and the second joint bearing 340, so that the second joint bearing 340 and the connecting plates 241 are prevented from being in direct contact to generate serious abrasion, further the abrasion of the second joint bearing 340 is delayed, the service life of the second joint bearing 340 is prolonged, and the action precision of the wrist structure 1000 is ensured.

In other embodiments, the end of the third connecting arm 240 away from the main body plate 210 may also be fixedly connected with a ball structure. The end of the adapter sleeve 142 away from the second mounting plate 112 may be provided with a spherical groove matching with the ball structure. The ball head structure is rotatably installed in the spherical groove, so that the universal pivoting of the third connecting arm 240 and the second assembly plate 112 can be realized, and the universal pivoting of the third connecting arm 240 and the mounting frame 110 can be realized.

As shown in fig. 1, further, the first end 1101 of the mounting bracket 110 is also provided with a first mounting plate portion 111 opposite to the second mounting plate portion 112. The wrist structure 1000 also includes a support bar 400. One end of the support bar 400 may be connected to the first fitting plate portion 111, and the other end of the support bar 400 may be connected to the second fitting plate portion 112. Thus, the overall structural strength of the wrist structure 1000 can be improved.

Also provided in embodiments is a robot that may include the wrist structure 1000 provided in embodiments. Wherein the first end 1101 of the mounting bracket 110 may be hinged to the large arm of the robot. The palm of the robot may be mounted to the body plate portion 210 of the carrier plate 200.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Although embodiments of the present application have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives, and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the application.

Claims (10)

1. A wrist-arm structure, comprising:

the small arm comprises a mounting frame, a first telescopic mechanism and a second telescopic mechanism, wherein the mounting frame comprises a first end and a second end, and the first telescopic mechanism and the second telescopic mechanism are arranged at the first end in parallel and extend to the second end;

the bearing plate comprises a first connecting arm, a third connecting arm and a second connecting arm which are sequentially arranged in parallel, wherein the third connecting arm is universally pivoted to the second end, the first connecting arm and one end of the first telescopic mechanism, which is close to the second end, are universally pivoted, and the second connecting arm and one end of the second telescopic mechanism, which is close to the second end, are universally pivoted.

2. The cantilever structure of claim 1, wherein the first telescoping mechanism includes a drive member and a drive rod assembly drivingly connected thereto, the drive member being mounted to the first end, the drive rod assembly extending to the second end and being pivotally connected to the first connecting arm in a universal manner.

3. The cantilever structure of claim 2, wherein the drive member is a motor, and the first telescoping mechanism further comprises a screw and an adapter;

the screw rod is rotatably arranged on the mounting frame and is connected with the output end of the driving piece;

the adapter sleeve is arranged on the screw rod and is in threaded fit connection with the screw rod, and one end, far away from the first connecting arm, of the transmission rod assembly is hinged to the adapter.

4. A wrist structure according to claim 2 or 3, wherein the drive rod assembly comprises a first adapter, a sleeve, a telescopic rod and a second adapter;

one end of the first adapter is in transmission connection with the output end of the driving piece, and one end of the first adapter, which is far away from the driving piece, is fixedly connected with the sleeve;

one end of the telescopic rod is arranged in the sleeve in a floating mode, and the other end of the telescopic rod is arranged in a telescopic mode relative to one end, away from the first adapter, of the sleeve;

the second adapter is connected to one end of the telescopic rod, which is far away from the first adapter, and one end of the second adapter, which is far away from the telescopic rod, is in universal pin joint with the first connecting arm.

5. The cantilever structure according to claim 4, wherein a first flange is provided on a peripheral side of one end of the telescopic rod, which is close to the first adapter, and a second flange is provided on an inner wall of one end of the sleeve, which is far from the first adapter;

the transmission rod assembly further comprises a first elastic piece and a second elastic piece, the first elastic piece is abutted between the first adapter and the first flange, and the second elastic piece is sleeved on the telescopic rod and abutted between the first flange and the second flange.

6. The cantilever structure of claim 1, wherein a first connecting shaft is connected to an end of the first connecting arm adjacent to the first telescopic mechanism, and the first connecting shaft is universally pivoted with the first telescopic mechanism through a first joint bearing.

7. The cantilever structure according to claim 1 or 6, wherein the third connecting arm comprises two connecting plates with opposite intervals, and a second connecting shaft is connected between the two connecting plates;

one side of the second end, which is far away from the first end, is also connected with an adapter sleeve, the adapter sleeve is sleeved on the second connecting shaft, and a second joint bearing is arranged between the adapter sleeve and the second connecting shaft.

8. The cantilever structure according to claim 7, wherein a spacer is sandwiched between the second knuckle bearing and both of the connecting plates.

9. The cantilever structure of claim 1, further comprising a support bar connected between the first and second ends.

10. A robot comprising a wrist structure according to any one of claims 1 to 9.