WO2020133269A1 - Limiting device, mechanical arm, and robot - Google Patents

Abstract

A limiting device (100), a mechanical arm (200) and a robot (300). The limiting device comprises: a rotating shaft output member (110) and a rotating shaft fixing member (120), the rotating output member rotating with the rotating shaft with respect to the rotating shaft fixing member; a limiting member (130), restricted and contained in a blocking area (150) which is provided on the rotating shaft fixing member; a guide member (140), connected to the rotating shaft output member and moving synchronously with the rotating shaft output member; wherein when the guide member moves to the blocking area, the guide member drives the limiting member to move along the blocking area, and when the guide member moves to one end of the blocking area, the limiting member abuts on the edge of the blocking area to prevent continued movement of the guide member. By means of the limiting device, excessive winding and twisting of cables in the mechanical arm caused by factors such as power failure and zero loss can be avoided.

Description

Limit device, mechanical arm and robot 【Technical field】

This application relates to the technical field of robots, in particular to a limiting device, a robot arm and a robot.

【Background technique】

The robot is a multi-joint manipulator or a multi-degree-of-freedom machine device applied in many fields. The robot is driven by a motor and can automatically perform work. It realizes various functions by its own power and control capabilities.

In the prior art, the robot generally uses a fixed limit structure to limit the rotation angle of the robot joint, so that the robot can only work or stop in the specified working space. However, if a fixed limit structure is used, the rotation angle of the robot joint can only be less than 360 degrees. For a robot with a joint rotation angle greater than or equal to 360 degrees, if the zero position of the motor encoder is accidentally lost at a certain angle, it is easy to make the robot difficult to return to the zero position. At this time, if the robot joint continues to rotate, it will often break the robot. Cables, the robot cannot be used normally.

[Invention content]

In view of this, the present application provides a limiting device, a robotic arm, and a robot to avoid excessive winding and twisting of cables in the robotic arm due to power failure and the like.

In order to solve the above technical problems, a technical solution adopted by the present application is to provide a limit device, including:

A rotating shaft output member and a rotating shaft fixing member, the rotating output member rotates relative to the rotating shaft fixing member with the rotating shaft;

The limiting member is restricted to be contained in a blocking area, and the blocking area is provided on the rotating shaft fixing member;

The guide member is connected with the output member of the rotating shaft and moves synchronously with the output member of the rotating shaft;

Wherein, when the guide moves to the blocking area, the guide drives the limiter to move along the blocking area, and when the guide moves to one end of the blocking area, the limit The bit piece abuts on the edge of the blocking area to prevent the guide piece from continuing to move.

In order to solve the above technical problems, another technical solution adopted by the present application is to provide a mechanical arm, which includes:

Two adjacent arthropod assemblies, the two adjacent arthropod assemblies can rotate relatively;

A limiter, which is restricted to be contained in a blocking area, the blocking area is disposed on one of the two adjacent arthropod assemblies, or on one of the two adjacent arthropod assemblies On the connecting piece where the components are connected;

The guide is connected to the other arthropod assembly of the two adjacent arthropod assemblies, and moves synchronously with the other arthropod assembly of the two adjacent arthropod assemblies;

Wherein, when the guide moves to the blocking area, the guide drives the limiter to move along the blocking area, and when the guide moves to one end of the blocking area, the limit The bit piece abuts on the edge of the blocking area to prevent the guide piece from continuing to move.

In order to solve the above technical problems, another technical solution adopted by the present application is to provide a robot including the above-mentioned mechanical arm.

The beneficial effect of the present application is that: the limiting device of the present application is used to limit the accommodation of the limiting member by providing a blocking area on the rotating shaft fixing member, and at the same time, a guide member is also provided on the rotating output member rotating relative to the rotating shaft fixing member, When the guide moves to the blocking area, the limiter moves, and when the guide moves to one end of the blocking area, the limiter abuts the edge of the blocking area to prevent the guide from continuing to move, thereby preventing the rotating output member from opposing The rotating shaft fixing member rotates to avoid the excessive rotation of the rotating output member relative to the rotating shaft fixing member. Therefore, when the limit device is used for a mechanical arm, for example, two arthropod bodies are respectively connected to the rotating output member and the rotating shaft fixing member, it can prevent Excessive relative rotation of the two articulation bodies to avoid excessive winding and twisting of the cables in the robot arm due to power loss and zero loss.

[Description of the drawings]

In order to more clearly explain the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For a person of ordinary skill in the art, without paying any creative work, other drawings can be obtained based on these drawings. among them:

1 is a schematic structural view of an embodiment of a limiting device of the present application;

2 is a schematic diagram of the explosion structure of the limiting device in FIG. 1;

FIG. 3 is a schematic structural view of the stopper in FIG. 1;

4 is a schematic structural diagram of a limiting device in an application scenario;

5 is a schematic structural view of the guide in FIG. 1;

6 is a schematic structural view of the rotating shaft fixing member in FIG. 1;

7 is a schematic structural diagram of a limiting device in another application scenario;

8 is a schematic structural view of an embodiment of a robot arm of the present application;

9 is a schematic diagram of the explosion structure of the mechanical arm in FIG. 8;

10 is a cross-sectional view along A-A plane in FIG. 8;

11 is a schematic structural view of an embodiment of the robot of the present application.

【detailed description】

The technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work fall within the scope of protection of the present application.

1 to 2, FIG. 1 is a schematic structural diagram of an embodiment of a limiting device of the present application, and FIG. 2 is an exploded schematic structural diagram of the limiting device in FIG. 1. The limiting device 100 includes a rotating shaft output member 110, a rotating shaft fixing member 120, a limiting member 130, and a guide member 140.

The rotating shaft output member 110 is connected to a rotating shaft (not shown), and is driven by the rotating shaft to rotate relative to the rotating shaft fixing member 120. The limiting device 100 of the present application is used for a mechanical arm. Specifically, the rotating shaft output member 110 and the rotating shaft fixing member 120 can be connected to two arthropod bodies respectively, and connected to the rotating shaft output member 110 under the driving of the rotating shaft Of the articulated body rotates relative to the articulated body connected to the rotating shaft fixture 120. Of course, in other embodiments, the position-limiting device 100 can also be used for devices that need to limit the rotation angle.

In the prior art, if the rotation angle of the rotating shaft output member 110 relative to the rotating shaft fixing member 120 exceeds a preset angle range, an accident is likely to occur. For example, when cables are wound on the articulated body connected to the rotating shaft output member 110 and the rotating shaft fixing member 120 respectively, if the two articulated bodies are relatively over-rotated due to power outage of the robot arm or loss of zero position, etc. If the rotation angle of the rotating shaft output member 110 relative to the rotating shaft fixing member 120 exceeds a preset angle range, the cable is likely to be excessively entangled and twisted, which may cause breakage.

In view of this situation, the present application provides a limiter 130 and a guide 140. The limiter 130 is restricted to be contained in the blocking area 150, wherein the blocking area 150 is disposed on the rotating shaft fixing member 120, the guide 140 and the rotating shaft output member 130 In connection, when the rotating shaft output member 130 rotates, the guide member 140 moves in synchronization with it.

Specifically, the limiting member 130 can only move in the blocking area 150 and cannot move to other areas outside the blocking area 150. When the guide 140 moves to the blocking area 150, the guide 140 contacts at least part of the limiter 130 to exert a force on the limiter 130, thereby driving the limiter 130 to move along the blocking area 150, when the guide 140 When moving to one end of the blocking area 150, the limiter 130 will abut the edge of the blocking area 150 to prevent the limiter 130 from continuing to move, so that the limiter 130 stops moving, because at least the guide 140 and the limiter 130 Partial contact, so if the guide 140 wants to continue to move, the limiter 130 exerts a force on the guide 140 to prevent the guide 140 from continuing to move, and because the guide 140 is connected to the rotary shaft output 110, the rotary shaft The output member 110 also stops rotating relative to the rotating shaft fixing member 120.

Normally, the rotation angle range of the rotating shaft output member 110 relative to the rotating shaft fixing member 120 is set according to the following principles: During normal operation, if the guide member 140 moves to the blocking area 150, the limit member 130 is driven by the guide member 140 It will not move to the end of the blocking area 150.

Therefore, if a fault occurs and the rotating shaft output member 110 rotates relative to the rotating shaft fixing member 120 beyond a predetermined angle range, the stopper 130 will move to one end of the blocking area 150 under the guidance of the guide member 140, thereby preventing the guide member 140 from continuing Movement, indirectly prevents the rotation shaft output member 110 from rotating relative to the rotation shaft fixing member 120, to avoid that the two arthropod bodies connected to the rotation shaft output member 110 and the rotation shaft fixing member 120 are caused by excessive rotation, such as excessive winding and breakage of the cable Wait for an accident. At the same time, since the guide 140 can move along the blocking area 150, in this embodiment, the rotation angle of the rotating shaft output member 110 relative to the rotating shaft fixing member 120 can be greater than 360 degrees, for example, the rotating shaft output member 110 relative to the rotating shaft fixing member The 120 rotation angle range is -190 degrees to 190 degrees.

Among them, in order to reduce the friction force that the limiter 130 receives when moving along the blocking area 150 and prolong its service life, the limiter 130 is a roller 130, wherein the roller 130 may be a regular shape (as shown in FIG. 3a), It may also be an irregular shape (as shown in FIG. 3b, in FIG. 3b, the stopper 130 is stepped). Of course, in other embodiments, the limiting member 130 may also be a ball, which is not limited herein.

The blocking area 150 may be a groove or a strip-shaped through hole provided on the rotating shaft fixing member 120. The groove or the through hole restricts the accommodation of the limiting member 130 by cooperating with some baffles, limiting blocks and other structures.

In the application scenario of FIG. 4, at least part of the limiting member 130 extends from the blocking area 150 in the direction perpendicular to the plane where the rotation shaft fixing member 120 is located, that is, at least part of the limiting member 130 protrudes from the plane where the rotation shaft fixing member 120 is located The protrusion is formed. At this time, the end of the guide 140 that is not connected to the rotating shaft output member 110, that is, the free end, crosses the gap between the rotating shaft output member 110 and the rotating shaft fixing member 120, and faces the rotating shaft fixing member 120. The plane of the is extended and contacts the protrusion of the stopper 130.

Optionally, in this application scenario, the limiting member 130 adopts the structure shown in FIG. 3b, a part of which is accommodated in the blocking area 150, and another part protrudes outward from the surface of the rotating shaft fixing member 120.

Optionally, in this application scenario, the blocking area 150 may be provided at any position of the rotating shaft fixing member 120, as long as the end of the guide member 140 that is not connected to the rotating shaft output member 110 can be self-rotating the shaft with the limiting member 130 The convex portion on the surface of the fixing member 120 may be in contact. As shown in FIG. 4a, the blocking area 150 is in communication with the gap between the rotating shaft output member 110 and the rotating shaft fixing member 120; as shown in FIGS. 4b and 4c, the blocking area 150 is not in contact with the rotating shaft output member 110 and the rotating shaft The gaps between the fixing members 120 are in communication.

In another application scenario, all of the limiting member 130 is accommodated in the blocking area 150, that is, the limiting member 130 has no part protruding outward from the surface of the rotating shaft fixing member 120.

Specifically, referring to FIG. 1 and FIG. 2 again, in this application scenario, an annular accommodating space 160 is provided between the rotating shaft output member 110 and the rotating shaft fixing member 120, and the blocking area 150 is a part of the annular accommodating space 160 Accommodation space 150. The end of the guide member 140 that is not connected to the rotating shaft output member 110 extends into the annular accommodating space 160. When the rotating shaft output member 110 rotates relative to the rotating shaft fixing member 120, the end of the guide member 140 that is not connected to the rotating shaft output member 110 The ring-shaped accommodating space 160 moves. When the guide 140 moves to the blocking area 150, that is, to the partial accommodating space 150, the end of the guide 140 that is not connected to the rotating shaft output member 110 is at least partially in contact with the limiting member 130 Therefore, the limiting member 130 can be driven to move along the partial accommodating space 150.

In this application scenario, referring to FIGS. 1 and 5, the guide 140 includes: a first flat plate 141 parallel to and connected to the rotating shaft output 110, standing vertically from the side of the first flat plate 141, and facing the annular receiving space The second flat plate 142 extending 160 and the extending piece 143 connected to the second flat plate 142 and extending along the annular receiving space 160. Optionally, the height of the second flat plate 142 matches the depth of the annular accommodating space 160 to ensure that when the guide member 140 moves to the partial accommodating space 150, the extension member 143 can contact at least part of the limiting member 130, thereby Apply a force to the stopper 130.

2 and 6, in this application scenario, the rotating shaft output member 110 includes a cylindrical output member 111, the rotating shaft fixing member 120 includes a ring-shaped fixing member 121, and the ring-shaped fixing member 121 is sleeved on the outer periphery of the cylindrical output member 111 The outer side wall of the cylindrical output member 111 and the inner side wall of the ring-shaped fixing member 121 form a ring-shaped accommodating space 160. The cylindrical output member 111 may be a hollow structure or a solid structure, which is not limited herein. Meanwhile, in other application scenarios, the rotating shaft output member 110 may also include a ring-shaped output member instead of the cylindrical output member 111.

As shown in FIG. 6, the annular fixing member 121 includes an annular surface 1211 and an inner side wall standing vertically from the outer periphery of the annular surface. The inner side wall of the annular fixing member 121 includes a first inner side wall 1212 and a second inner side wall 1213. The first inner side wall 1212 and the outer side wall of the cylindrical output member 111 constitute a partial receiving space 150 of the annular receiving space 160, that is, the blocking area 150, wherein the first inner side wall 1212 of the annular fixing member 121 reaches the cylindrical output member 110 The vertical distance of the outer side wall is greater than the vertical distance from the second inner side wall 1213 of the annular fixing member 121 to the outer side wall of the cylindrical output member 111. That is, the width of the partial accommodating space 150 is larger than the width of the other accommodating spaces of the annular accommodating space 160. When the stopper 130 moves to one end of the partial accommodating space 150, the first inner side wall 1211 and the second The transition section of the inner side wall 1212 will abut the limiting member 130, so as to ensure that the limiting member 130 is restricted to be accommodated in the partial accommodating space 150. Optionally, the inner diameter of the annular surface 1211 is equal to the outer diameter of the cylindrical output member 111. Optionally, for the frictional force received when the limiting member 130 contacts the edge of the blocking area 150, the transition section of the first inner side wall 1211 and the second inner side wall 1212 may adopt a smooth transition structure.

2, the thickness of the ring-shaped fixing member 121 at the first inner side wall 1212 is smaller than the thickness of the ring-shaped fixing member 121 at the second inner side wall 1213. At this time, in order to ensure that all the limiting members 130 can be accommodated in the blocking area 150, the thickness of the limiting members 130 is smaller than the thickness of the annular fixing member 121 at the first inner side wall 1212.

At the same time, the limiting device 100 further includes a cover plate 170, which is fixed to the annular fixing member 121 at the first inner side wall 1212, so that the limiting member 130 is accommodated in the partial accommodating space 150, and the limiting member 130 The part of will be covered by the cover plate 170 to hide and protect it. The cover plate 170 may be detachably fixed to the ring-shaped fixing member 121 at the first inner side wall 1212 by bolts or pins. When a fault occurs, the cover 170 can be removed to repair the stopper 130.

Optionally, in other application scenarios, as shown in FIG. 7, when the cylindrical output member 111 has a hollow structure, the cylindrical output member 111 may also be sleeved on the outer periphery of the ring-shaped fixing member 121. It can be understood that at this time, except that the relative positions of the cylindrical output member 111 and the ring-shaped fixing member 121 are different, the rest of the structure may be the same or detailed as the structure in the above scenario. For details, please refer to the above application scenario. Repeat.

8 to 9, FIG. 8 is a schematic structural view of an embodiment of a robot arm of the present application, and FIG. 9 is a schematic exploded structural diagram of the robot arm in FIG. 8. The robot arm 200 includes: articulation assemblies 210 and 220.

The arthropod assemblies 210 and 220 can rotate relatively. In this embodiment, the relative rotation angle between the two can be greater than 360 degrees. Generally speaking, the relative rotation angles of the limb assemblies 110 and 120 are preset, for example, -190 degrees to 190 degrees. If the relative rotation angle of the limb assemblies 210 and 220 exceeds the preset range during the operation of the robot 200, Then the cable connected with it is easy to be excessively twisted and twisted.

Therefore, this embodiment is the same as the above-mentioned embodiment. This embodiment is provided with a limiter 230 and a guide 240. The limiter 230 is restricted to be contained in the blocking area 250, wherein the blocking area 250 is disposed on one of the two limb assemblies 210, 220 On the component, or when there is a connector connected to the arthropod component, the blocking area 250 is provided on the connector connected to the arthropod component. In an application scenario, the connector is used to connect the two arthropod components 210, 220 joint. The guide 240 is connected to another articulation assembly, and when the articulation assembly rotates, the guide 240 moves in synchronization with it. That is, regardless of the relative positions of the two limb assemblies 210, 220, one limb assembly or the connecting member connected thereto is provided with a blocking area 250, and the other limb assembly is provided with a guide 240 that moves synchronously therewith.

In an application scenario, when the robotic arm 200 is calibrated to return to the zero position, even when it returns to the initial position, the guide 240 coincides with the zero position. It is worth noting that the guide member 240 coincides with the zero position here: the guide member 240 coincides with the zero position where the two articulation assemblies 110 and 120 are connected. When the robot arm 200 includes a plurality of articulated components, there will be a joint for every two articulated components, and there will be a zero position for each joint. As a reference for the movement of the robot arm 200, the determination of the zero position is not only a prerequisite for the normal operation of the robot arm 200, but also greatly affects the positioning accuracy of the robot arm 200's power. By setting the position of the guide 240 to the zero position, it is ensured that during the relative movement of the two limb assemblies 210 and 220, the angle at which the guide 240 is offset from the zero position is the relative movement angle of the limb assemblies 210 and 220. When the rotation angle between the arthropod assemblies 210 and 220 exceeds the maximum angle due to power failure, zero loss, etc., the guide 240 can guide the limiter 230 to one end of the blocking area 250 in time, thereby passing the limiter 230 The effect of preventing the relative movement of the arthropod assemblies 110, 120.

In an application scenario, when the robotic arm 200 is calibrated to return to the zero position, the axis of symmetry of the blocking area 250 passes through the zero position. As shown in FIG. 9, the two ends of the blocking area 250 are respectively denoted as point A and point B. When the articulation assembly 210 rotates counterclockwise with respect to the articulation assembly 220, the arc formed from the point A to the zero position corresponds to the 210 relative arthropod When the assembly 220 rotates clockwise, the central angle corresponding to the arc formed from the point B to the zero position is the maximum angle that the articulation assembly 210 rotates clockwise relative to the articulation assembly 220. When the robot 200 is calibrated to return it to the zero position , The axis of symmetry of the blocking area 250 passes through the zero point position, so the maximum angle of articulation assembly 210 relative to articulation assembly 220 clockwise rotation is the same as the maximum angle of articulation assembly 210 relative to articulation assembly 220 counterclockwise rotation, for example, both are 190 degrees. The clockwise rotation of the assembly 210 relative to the articulation assembly 220 is a positive direction, and the angle range of the rotation of the articulation assembly 210 relative to the articulation assembly 220 is -190 degrees to +190 degrees. It can be understood that, in other application scenarios, when the robotic arm 200 is calibrated to return to the zero position, the axis of symmetry of the blocking area 150 may not pass through the zero position, that is, the articulation assembly 210 is aligned with the articulation assembly 220 The maximum angle of the clockwise rotation is different from the maximum angle of the articulation assembly 210 relative to the articulation assembly 220 counterclockwise. For example, the angle of rotation of the articulation assembly 210 relative to the articulation assembly 220 ranges from -100 degrees to +280 degrees. It is worth noting that by passing the axis of symmetry of the blocking area 250 through the zero position, it is also convenient to find the zero position by analyzing the position of the blocking area 250 when the zero position is lost.

In this embodiment, the limiter 230, the guide 240, and the blocking area 250 correspond to the same or similar to the limiter 130, the guide 140, and the blocking area 150 in the above-described embodiment of the limiting device 100. For details, see the above The implementation is not repeated here.

Similar to the above embodiment, in an application scenario, at least part of the limiting member 230 extends outward from the blocking area 250, and the blocking area 250 may be disposed at any position on the articulation component or the connecting piece connected thereto to guide The end of the member 240 that is not connected to the articulation assembly extends to another articulation assembly or connection member, and is in contact with at least part of the stopper 230 extending outward from the blocking area 250.

In another application scenario, as shown in FIG. 10, an annular accommodating space 260 is provided between two adjacent arthropod assemblies 210 and 220, and the blocking area 250 is a part of the accommodating space 250 of the annular accommodating space 260.

In this application scenario, the two adjacent limb assemblies 210 and 220 specifically include a first limb assembly 210 and a second limb assembly 220.

The first limb assembly 210 includes a cylindrical output member 211; the second limb assembly 220 includes an annular fixing member 221, wherein the cylindrical output member 211, the annular fixing member 221, and the cylindrical output member 111 in the above-described embodiment of the limiting device, The ring-shaped fixing member 121 corresponds to the same. It can be understood that the cover plate 270 also exists in this embodiment, and the structure of the cover plate 270 is the same as that of the cover plate 170 of the above-mentioned embodiment. For the detailed structure, please refer to the above-mentioned embodiment, which will not be repeated here.

Wherein, when the annular fixing member 221 is sleeved on the outer periphery of the cylindrical output member 211 and the inner side wall of the annular fixing member 221 and the outer side wall of the cylindrical output member 211 form an annular accommodating space 260, the first articulation assembly 210 further includes A first limb body 212 connected to one end of the cylindrical output member 211, and the second limb assembly 220 further includes a second limb body 222 connected to the ring-shaped fixing member 121 and extending away from the first limb body 212. The articular body 222 is provided with an accommodating cavity (not shown), so that the cylindrical output member 211 is accommodated in the accommodating cavity.

The robot arm 200 further includes a driving member 280. The casing 281 of the driving member 280 is connected to the end of the second limb body 222 that is not connected to the ring-shaped fixing member 221. The output shaft 282 of the driving member 280 is accommodated in the second limb body The cylindrical output member 211 in the receiving cavity of 222 is connected to drive the first limb body 212 to rotate relative to the second limb body 222. Among them, the driving member 280 is a motor.

Optionally, in other embodiments, more driving members 280 may also be included, for example, another driving member 280 is provided to drive the rotation of the second limb body 222, and the first limb body 212 and the second limb body 222 may be used as A whole rotates synchronously.

Referring to FIG. 11, FIG. 11 is a schematic structural diagram of an embodiment of a robot of the present application. The robot 300 includes a robot arm 200. The robot arm 200 is the robot arm 200 in any one of the foregoing embodiments. For details, refer to the foregoing embodiments. This will not be repeated here.

The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any changes to the equivalent structure or equivalent process made by the description and drawings of this application, or used directly or indirectly in other related technologies In the field, the same reason is included in the scope of patent protection of this application.

Claims (19)

A limit device, including: A rotating shaft output member and a rotating shaft fixing member, the rotating output member rotates relative to the rotating shaft fixing member with the rotating shaft; The limiting member is restricted to be contained in a blocking area, and the blocking area is provided on the rotating shaft fixing member; The guide member is connected with the output member of the rotating shaft and moves synchronously with the output member of the rotating shaft; Wherein, when the guide moves to the blocking area, the guide drives the limiter to move along the blocking area, and when the guide moves to one end of the blocking area, the limit The bit piece abuts on the edge of the blocking area to prevent the guide piece from continuing to move. The limit device according to claim 1, wherein An annular accommodating space is provided between the rotating shaft output member and the rotating shaft fixing member, and the blocking area is a partial accommodating space of the annular accommodating space. The limit device according to claim 2, wherein The rotating shaft output member includes a cylindrical output member, and the rotating shaft fixing member includes an annular fixing member, and the annular fixing member is sleeved on the outer periphery of the cylindrical output member to make the outer side wall of the cylindrical output member And the inner side wall of the annular fixing member constitute the annular accommodating space. The limit device according to claim 3, wherein The annular fixing member includes an annular surface and the inner side wall standing vertically from the outer periphery of the annular surface. The inner sidewall of the annular fixing member includes a first inner side wall and a second inner side wall. The first inner side wall and the outer side wall of the cylindrical output member constitute the partial accommodating space, wherein the first inner side wall of the annular fixing member reaches the The vertical distance of the outer side wall is greater than the vertical distance of the second inner side wall of the annular fixing member to the outer side wall of the cylindrical output member. The limit device according to claim 4, wherein: The thickness of the annular fixing member at the first inner side wall is smaller than the thickness of the annular fixing member at the second inner side wall; The limiting device further includes a cover plate that is fixed to the ring-shaped fixing member at the first inner side wall, so that the limiting member is restricted in the partial accommodation space. The limit device according to claim 2, wherein The guide member includes a first flat plate connected to the rotating shaft output member, a second flat plate standing vertically from one side of the first flat plate and extending toward the annular accommodating space, and the first flat plate An extension piece connected by two plates and extending along the annular accommodating space. The limiting device according to claims 1-6, wherein the limiting member is a roller or a ball. A mechanical arm, including: Two adjacent arthropod assemblies, the two adjacent arthropod assemblies can rotate relatively; A limiter, which is restricted to be contained in a blocking area, the blocking area is disposed on one of the two adjacent arthropod assemblies, or on one of the two adjacent arthropod assemblies On the connecting piece where the components are connected; The guide is connected to the other arthropod assembly of the two adjacent arthropod assemblies, and moves synchronously with the other arthropod assembly of the two adjacent arthropod assemblies; Wherein, when the guide moves to the blocking area, the guide drives the limiter to move along the blocking area, and when the guide moves to one end of the blocking area, the limit The bit piece abuts on the edge of the blocking area to prevent the guide piece from continuing to move. The robotic arm according to claim 8, wherein When the robot arm is calibrated to return to the zero position, the guide coincides with the zero position. The robotic arm according to claim 8, wherein When the robotic arm is calibrated to return to the zero position, the axis of symmetry of the blocking zone passes through the zero position. The robotic arm according to claim 8, wherein An annular accommodating space is provided between the two adjacent arthropod assemblies, and the blocking area is a partial accommodating space of the annular accommodating space. The robotic arm according to claim 11, wherein The two adjacent articulation assemblies include a first articulation assembly and a second articulation assembly; the first articulation assembly includes a cylindrical output member, the second articulation assembly includes an annular fixing member, and the annular fixing member is sleeved on The outer periphery of the cylindrical output member and the outer side wall of the cylindrical output member and the inner side wall of the annular fixing member constitute the annular accommodating space. The robot arm according to claim 12, wherein The annular fixing member includes an annular surface and the inner side wall standing vertically from the outer periphery of the annular surface. The inner sidewall of the annular fixing member includes a first inner side wall and a second inner side wall. The first inner side wall and the outer side wall of the cylindrical output member constitute the partial accommodating space, wherein the first inner side wall of the annular fixing member reaches the The vertical distance of the outer side wall is greater than the vertical distance of the second inner side wall of the annular fixing member to the outer side wall of the cylindrical output member. The robot arm according to claim 13, wherein The thickness of the annular fixing member at the first inner side wall is smaller than the thickness of the annular fixing member at the second inner side wall; The mechanical arm further includes a cover plate, the cover plate is fixed to the ring-shaped fixing member at the first inner side wall, so that the position-limiting member is restricted in the partial accommodating space. The robot arm according to claim 12, wherein The first limb assembly further includes a first limb body connected to one end of the cylindrical output member; the second limb assembly further includes a first limb body connected to the ring-shaped fixing member and away from the first limb body The second limb body extending in the direction of the second limb body is provided with a containing cavity so that the cylindrical output member is received in the containing cavity. The robot arm according to claim 15, wherein The robotic arm further includes a driving member, a housing of the driving member is connected to an end of the second limb body that is not connected to the ring-shaped fixing member, and an output shaft of the driving member is accommodated in the second The cylindrical output member in the accommodating cavity of the articulated body is connected to drive the first articulated body to rotate relative to the second articulated body. The robotic arm according to claim 11, wherein The guide includes a first flat plate connected to the arthropod assembly, a second flat plate standing vertically from one side of the first flat plate and extending toward the annular receiving space, and the second flat plate Extension pieces connected and extending along the annular receiving space. The robotic arm according to claims 8-17, wherein the stopper is a roller or a ball. A robot including the robot arm according to any one of claims 8-17.

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