CN216759945U

CN216759945U - Robot joint moment feedback assembly and multi-axis robot

Info

Publication number: CN216759945U
Application number: CN202220227015.1U
Authority: CN
Inventors: 胡天链; 陈刚; 周扬
Original assignee: Fude Robot Chengdu Co ltd
Current assignee: Fude Robot Chengdu Co ltd
Priority date: 2022-01-27
Filing date: 2022-01-27
Publication date: 2022-06-17
Anticipated expiration: 2032-01-27

Abstract

The utility model belongs to the technical field of robots, and discloses a robot joint torque feedback assembly, which comprises a first joint, a second joint and a deformation component, wherein the first joint is connected with the second joint through a first connecting rod; the second joint is rotationally connected with the first joint; the deformation component is arranged in the second joint, one end of the deformation component is connected with the first joint, and the other end of the deformation component is connected with the second joint; the deformation component is provided with at least one strain gauge. The utility model can realize high-precision torque feedback by utilizing a compact structure without additionally arranging a switching component. The utility model also discloses a multi-axis robot with the robot joint moment feedback assembly.

Description

Robot joint moment feedback assembly and multi-axis robot

Technical Field

The utility model belongs to the technical field of robots, and particularly relates to a robot joint torque feedback assembly and a multi-axis robot.

Background

The integrated joint is a main component constituting a robot, and a plurality of integrated joints are generally connected in series to be assembled as a cooperative arm of the robot. The cooperative mechanical arm can safely interact/contact with people directly, so that the cooperative mechanical arm has to have a force feedback characteristic and can stop in time when being subjected to external force, and the safety of man-machine cooperation can be ensured.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model discloses a robot joint torque feedback assembly, which can realize high-precision torque feedback by utilizing a compact structure without additionally arranging a switching component. The utility model also discloses a multi-axis robot with the robot joint moment feedback assembly. The specific technical scheme of the utility model is as follows:

a robot joint torque feedback assembly, comprising:

a first joint;

a second joint rotationally coupled to the first joint; and

the deformation component is arranged in the second joint, one end of the deformation component is connected with the first joint, and the other end of the deformation component is connected with the second joint;

wherein the deformation component is provided with at least one strain gauge.

When first joint received external moment, can rotate for the second joint, at this moment, because the second joint keeps static for first joint, consequently, the motion of first joint makes the deformation part produce the deformation, thereby lead to the foil gage to warp, at this moment, because the resistance of foil gage changes, make resistance change equivalence be output voltage's change through bridge circuit, thereby change through measuring output voltage alright obtain the size of torque value finally realize measuring the moment of torsion, utilize the moment of torsion value to realize the judgement of external moment size, the high accuracy feedback of external moment has been guaranteed.

Preferably, the deformation member includes:

the stress end is connected with the first joint;

the fixed end is connected with the second joint; and

the deformation thin wall is of a circular ring structure, one end of the deformation thin wall is connected with the stress end, and the other end of the deformation thin wall is connected with the fixed end;

wherein, at least one strain gauge is arranged at the inner side or the outer side of the deformation thin wall.

The stress end is used for receiving the external moment transmitted by the first joint, and the movement of the stress end causes the deformation of the deformation thin wall, so that the strain gauge is deformed, and the resistance value of the measuring bridge is changed.

Preferably, the stress end is of a circular ring structure and is arranged at the outer edge of the deformation thin wall;

the stress end is provided with a plurality of first connecting holes in the axial direction; the deformation component is connected with the first joint through the first connecting hole.

Because the deformation part sets up in the second joint, and except that the deformation part in the second joint, still include other necessary parts, therefore, on the basis that the deformation thin wall is the ring structure, the stress end also is the ring structure equally, and at this moment, first connecting hole can be fine practice thrift installation space, further guarantees feedback assembly's compactness.

Preferably, the axial direction of the stress end is provided with a plurality of tool holes, and the axial direction of the fixed end is provided with a plurality of U-shaped grooves corresponding to the tool holes; the deformation component is connected with the second joint through a tool hole and a U-shaped groove which are correspondingly arranged.

The deformation component can be well connected to the second joint by matching the tool hole and the U-shaped groove, so that the structural stability is ensured, and the deformation thin wall is deformed when the first joint is subjected to external moment; on this basis, similar to the first connection hole, the compactness of the feedback assembly is ensured.

Preferably, the deformation member includes:

the stress end is connected with the first joint;

the fixed end is connected with the second joint; and

the middle section is of a circular ring structure, one end of the middle section is connected with the stress end, and the other end of the middle section is connected with the fixed end;

wherein the outer diameter of the middle section is smaller than the outer diameter of the force bearing end; the outer diameter of the middle section is smaller than that of the fixed end;

the outer edge of the middle section is provided with at least one reinforcing rib, one end of any reinforcing rib is connected with the stress end, and the other end of any reinforcing rib is connected with the fixed end; the strain gauge is arranged on the reinforcing rib.

When the first joint is subjected to external moment, the second joint is kept static relative to the first joint, and at the moment, the middle section of the deformation component is twisted because the deformation component is in a structure with two wide ends and a narrow middle part; in this structure, the strengthening rib is fine has guaranteed the stability between stress end and the stiff end, has avoided the part damage that transition deformation caused, and at this moment, the strengthening rib can follow the deformation, consequently, the foil gage that sets up on it also can produce the deformation to lead to bridge circuit's output voltage to change, realize the purpose of the high accuracy feedback of external moment.

Preferably, any one reinforcing rib is provided with a waist-shaped hole; the strain gauges are arranged on one side or two sides of the waist-shaped hole.

The waist-shaped holes are arranged, so that the deformation resistance of the reinforcing rib can be reduced on the basis of ensuring the reinforcing effect of the reinforcing rib, and the strain gauge is driven to deform better.

Preferably, the stress end is provided with a plurality of second connecting holes in the axial direction, and the deformation component is connected with the first joint through the second connecting holes.

The setting of second connecting hole can make the stress end and first joint be connected steadily, provides compact installation space for the feedback subassembly in the second joint.

Preferably, the fixed end is provided with a plurality of third connecting holes in the radial direction of the fixed end, and the deformation component is connected with the second joint through the third connecting holes.

The third connecting hole sets up to provide the stable relation of being connected with the second joint for the stiff end, and outside practicing thrift the volume that occupies in the second joint, made things convenient for the installation of deformation part simultaneously.

Preferably, the second joint is provided with a sinking platform, and the sinking platform is provided with a fourth connecting hole corresponding to the third connecting hole; the second joint penetrates through a third connecting hole and a fourth connecting hole which are correspondingly arranged through a fixing piece to be connected with the deformation component;

the sinking platform is provided with a sheath matched with the sinking platform.

Because the sinking platform is matched with the sheath, the fixing piece is well protected and shielded, the fixing piece is protected, and the appearance can be beautified.

A multi-axis robot comprising a robot joint torque feedback assembly as described above.

Compared with the prior art, the utility model realizes the installation of the feedback component in the second joint by utilizing a compact structure; when the first joint is subjected to external torque, deformation of the strain gauge is realized by deformation of the deformation component, so that the resistance of the strain gauge is changed, the resistance change is equivalent to the change of output voltage through a bridge circuit, the magnitude of a torque value can be obtained by measuring the change of the output voltage, and the magnitude of the external torque is reflected, so that the accurate measurement of the external torque is realized, and on the basis, an accurate mechanical model is not required to be obtained, and the flexibility and static friction force existing in the speed reducer can be ignored; in addition, the utility model does not need to increase the adapter, and has simple assembly, thereby having stronger practicability.

Drawings

FIG. 1 is a schematic diagram of one embodiment of the present invention;

FIG. 2 is an enlarged view of FIG. 1 at A;

FIG. 3 is a schematic view of a deformation element of the embodiment of FIG. 1;

FIG. 4 is a cross-sectional view of FIG. 3;

FIG. 5 is a schematic view of another embodiment of the present invention;

FIG. 6 is an enlarged view of FIG. 5 at B;

FIG. 7 is a schematic view of a deformation element of the embodiment of FIG. 5;

fig. 8 is a schematic view of the arrangement of the sheath in the embodiment of fig. 5.

In the figure: 1-a first joint; 2-a second joint; 3-a strain gauge; 4-an integrated flexible gear; 5-harmonic steel wheel; 6-wave generator; 7-a motor assembly; 8, fixing a shaft by a motor; 9-crossed roller bearings; 10-a force-bearing end; 11-a fixed end; 12-deformation thin wall; 13-a first connection hole; 14-a tool hole; 15-a U-shaped slot; 16-code disc; 17-an intermediate section; 18-reinforcing ribs; 19-kidney shaped holes; 20-a second connection hole; 21-a third connection hole; 22-sinking the platform; 23-sheath.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the present invention will be further described in detail with reference to the following embodiments.

The present embodiments provide a multi-axis robot including a robot joint torque feedback assembly. Specifically, the robot joint moment feedback assembly is applied to a seven-axis robot. Of course, in different embodiments, a two-axis robot, a three-axis robot, or other multi-axis robot. In the present embodiment, any two adjacent axes are made the first joint 1 and the second joint 2.

As shown in fig. 1 to 4, a robot joint torque feedback assembly comprises a first joint 1, a second joint 2 and a deformation component; the second joint 2 is rotationally connected with the first joint 1; the deformation component is arranged in the second joint 2, one end of the deformation component is connected with the first joint 1, and the other end of the deformation component is connected with the second joint 2; the deformation element is provided with at least one strain gauge 3.

In the present embodiment, it can be understood that, in order to generate relative rotation between the first joint 1 and the second joint 2, other components are further included between the first joint 1 and the second joint 2, and/or in the first joint 1 and the second joint 2, and specifically, the integrated flexspline 4, the harmonic steel wheel 5, the wave generator 6 and the motor assembly 7 are further included.

Wherein, the integrated flexible gear 4, the harmonic steel gear 5 and the wave generator 6 are all part of a harmonic reducer in the prior art and are parts which can be directly used by the technicians in the field; the integrated flexible gear 4 is a deformable gear part, and the transmission between the outer side tooth part of the integrated flexible gear 4 and the inner side tooth part of the harmonic steel gear 5 is in a harmonic gear transmission mode; the wave generator 6 can realize a driving effect, so that the integrated flexible gear 4 generates periodic elastic deformation waves according to a certain deformation rule.

Be equipped with motor fixed axle 8 in the second joint 2, motor element 7 is connected with motor fixed axle 8, rotates through motor element 7 drive first joint 1, and at this moment, the moment that it provided is interior moment. The integrated flexible gear 4 is sleeved on the motor fixing shaft 8 and is connected with the first joint 1 through a crossed roller bearing 9; the harmonic steel wheel 5 is sleeved on the outer side of the integrated flexible wheel 4 and is connected with the deformation component; the wave generator 6 is arranged on a motor fixing shaft 8 and is connected with the inner side of the integrated flexible gear 4.

From this, when motor element 7 normal operating, if first joint 1 receives the influence of external moment, then external moment loops through alternately roller bearing, integration flexbile gear 4 and harmonic steel wheel 5, with external moment transmission to deformation part, foil gage 3 warp this moment, the deformation of foil gage 3 causes bridge circuit output to be equivalent to resistance change's voltage, thereby change through measuring output voltage alright obtain the torque measurement result of high accuracy, can reflect external force moment of torsion size through the torque value, thereby realize people and the safe interaction and/or the contact of arm.

It should be noted that the bridge circuit is composed of the strain gauge 3, and there may be only one strain gauge 3, or there may be two strain gauges 3, three strain gauges, or more strain gauges. When the strain gauge 3 is plural, it is possible to obtain a more accurate value based on the comparative analysis. Of course, it will be appreciated that the effect is best when there are a plurality of strain gauges 3, evenly distributed in an array.

For better use of the present embodiment, the deformation component comprises a force bearing end 10, a fixed end 11 and a deformation thin wall 12; the stress end 10 is connected with the first joint 1; the fixed end 11 is connected with the second joint 2; the deformation thin wall 12 is in a circular ring structure, one end of the deformation thin wall is connected with the stress end 10, and the other end of the deformation thin wall is connected with the fixed end 11; at least one strain gauge 3 is arranged on the inner side or the outer side of the thin deformation wall 12.

In this embodiment, the three components are integrally formed to ensure the strength and stability of the use. It will be understood that the deformation of the deformation wall 12 is small and that the torsional deformation thereof is sufficient to support the deformation of the strain gauge 3.

In order to better use the embodiment, the stress end 10 is of a circular ring structure and is arranged at the outer edge of the deformation thin wall 12; the stress end 10 is provided with a plurality of first connecting holes 13 in the axial direction; the deformation element is connected to the first joint 1 via a first connection hole 13.

The harmonic steel wheel 5 is provided with a screw clearance hole matched with the first connecting hole 13, and the fixed connection of the harmonic steel wheel and the force bearing end 10 can be realized. On the basis of the structure, it is explained that the harmonic steel wheel 5 and the integrated flexible wheel 4 transmit torque through tooth-shaped meshing, the integrated flexible wheel 4 and the crossed roller bearing 9 are fixedly connected through screws, and the crossed roller bearing 9 and the first joint 1 are fixedly connected through screws.

For better use of the embodiment, the force-bearing end 10 is provided with a plurality of tool holes 14 in the axial direction thereof, and the fixed end 11 is provided with a plurality of U-shaped grooves 15 corresponding to the tool holes 14 in the axial direction thereof; the deformation element is connected to the second joint 2 by means of a correspondingly arranged tool hole 14 and a U-shaped groove 15.

The stress end 10 is provided with a tool hole 14, the fixed end 11 is provided with a U-shaped groove corresponding to the tool hole 14, and it can be understood that a straight line where a connecting line of the center of the tool hole 14 and the center of a circle where an arc of the U-shaped groove is located is parallel to a straight line where a central axis of the deformation thin wall 12 is located. Thus, when the tool hole 14 and the U-shaped groove 15 are fitted to each other, a screw is radially inserted from the U-shaped groove, and a screw driver is passed through the screw from the tool hole 14 to tighten the screw, thereby connecting the fixed end 11 and the second joint 2.

In this embodiment, in order to ensure that the deformation component occupies a smaller volume in the second joint 2 and facilitate the installation of the deformation component, the outer diameter of the deformation thin wall 12 is smaller than the outer diameter of the force-bearing end 10, and the outer diameter thereof is smaller than the outer diameter of the fixed end 11.

In addition, in the embodiment, the deformation component is a cover body structure, and a coded disc 16 can be arranged between the inner side of the deformation component and the motor fixing shaft 8 so as to realize angle measurement.

As shown in fig. 5 to 8, in other embodiments, the structure of the deformation element is different from that of the deformation element described above, specifically, the deformation element includes a force-bearing end 10, a fixed end 11 and a middle section 17; the stress end 10 is connected with the first joint 1; the fixed end 11 is connected with the second joint 2; the middle section 17 is in a circular ring structure, one end of the middle section is connected with the stress end 10, and the other end of the middle section is connected with the fixed end 11; the outer diameter of the middle section 17 is smaller than that of the force bearing end 10; the outer diameter of the middle section 17 is smaller than that of the fixed end 11; the outer edge of the middle section 17 is provided with at least one reinforcing rib 18, one end of any reinforcing rib 18 is connected with the stress end 10, and the other end is connected with the fixed end 11; the strain gauge 3 is provided to the rib 18.

In this embodiment, similar to the above embodiment, the harmonic reducer further includes an integrated flexible gear 4, a harmonic steel gear 5, and a crossed roller bearing 9, where the crossed roller bearing 9 is connected to the first joint 1, the integrated flexible gear 4 is connected to the crossed roller bearing 9, the harmonic steel gear 5 and the integrated flexible gear 4 are engaged by a tooth profile, one end of the deformation component is connected to the harmonic steel gear 5, and the other end is connected to the second joint 2.

In this embodiment, the deformable member can be regarded as a hollow cylinder or a frustum, and the two ends are the force-bearing end 10 and the fixed end 11, respectively, and the middle is provided with a groove to form the reinforcing rib 18. Thereby, the strain gauge 3 is provided to the rib 18. Of course, in order to ensure the transmission efficiency and the compact structure, in this embodiment, the deformation member is regarded as a hollow cylinder.

In order to better use the embodiment, any one of the reinforcing ribs 18 is provided with a kidney-shaped hole 19; the strain gauge 3 is disposed on one side or both sides of the kidney hole 19.

After the waist-shaped holes 19 are formed in the reinforcing ribs 18, the deformation thin walls 12 are formed on the side walls of the reinforcing ribs 18 due to the waist-shaped holes 19, and the deformation thin walls 12 can better transmit the deformation to the strain gauge 3. It will be appreciated that the strain gage 3 may be positioned on one or both sides of the kidney hole 19, where one or both sides, of course, include the inside and outside of the kidney hole 19. That is, each rib 18 has two deformation walls 12, and one or both sides of any one of the deformation walls 12 may be provided with the strain gauge 3.

Therefore, when the first joint 1 receives an external moment, the external moment is transmitted to the deformation component through the crossed roller bearing 9, the integrated flexible gear 4 and the harmonic steel wheel 5 in sequence, and the deformation component is connected with the second joint 2, so that a small deformation is formed at the deformation thin wall 12, the deformation directly causes the deformation of the adhesive strain foil 3, the resistance value of the bridge circuit is changed after the deformation of the strain foil 3, and the bridge circuit enables the resistance change to be equivalent to the change of the output voltage, so that the measurement of the torque value is realized.

It will of course also be appreciated that the thickness of the intermediate section 17 can be made with reference to the deformable wall 12 of the previous embodiment to better achieve the deformation under force.

For better use of this embodiment, the force-bearing end 10 is provided with a plurality of second connecting holes 20 in the axial direction thereof, and the shape-changing component is connected with the first joint 1 through the second connecting holes 20.

In this embodiment, in order to ensure that the fixing member can stably connect the deforming part and the harmonic steel wheel 5, the second connecting holes 20 are provided corresponding to the reinforcing ribs 18 and penetrate the reinforcing ribs 18 in the length direction of the reinforcing ribs 18, thereby ensuring the connection stability. In this embodiment, the four reinforcing ribs 18 are arranged in a circular array, thereby better providing the connection strength.

For better use of this embodiment, the fixing end 11 is provided with a plurality of third coupling holes 21 in a radial direction thereof, and the shape-changing member is coupled to the second joint 2 through the third coupling holes 21.

In this embodiment, the second joint 2 is provided with a countersunk screw clearance hole which is engaged with the third coupling hole 21, thereby achieving a stable coupling between the deformation member and the second joint 2.

On the basis, in order to protect the countersunk head screw and realize the aesthetic appearance of the mechanical arm, the second joint 2 is provided with a sinking platform 22, and the sinking platform 22 is provided with a fourth connecting hole corresponding to the third connecting hole 21; the second joint 2 penetrates through a third connecting hole 21 and a fourth connecting hole which are correspondingly arranged through a fixing piece to be connected with the deformation component; the sinking platform 22 is provided with a sheath 23 matched with the sinking platform.

Therefore, the embodiment described above embodies the advantages of compact and accurate feedback components in structure, has light overall weight and low manufacturing cost, can be applied to various robots, particularly miniature robots, can be applied to the fields of robots with high torque control requirements in the household, medical and service industries and the like, and has a wide market prospect.

The above are only preferred embodiments of the present invention, and it should be noted that the above preferred embodiments should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the utility model, and these modifications and adaptations should be considered within the scope of the utility model.

Claims

1. A robot joint torque feedback assembly, comprising:

a first joint;

a second joint rotationally coupled to the first joint; and

wherein the deformation component is provided with at least one strain gauge.

2. A robot joint torque feedback assembly according to claim 1, wherein said shape changing component comprises:

the stress end is connected with the first joint;

the fixed end is connected with the second joint; and

3. A robot joint moment feedback assembly according to claim 2, wherein said force-bearing end is of a ring structure and is disposed at the outer edge of said deformable thin wall;

4. A robot joint moment feedback assembly according to claim 3, wherein said force receiving end is provided with a plurality of tool holes in an axial direction thereof, and said fixed end is provided with a plurality of U-shaped grooves corresponding to the tool holes in the axial direction thereof; the deformation component is connected with the second joint through a tool hole and a U-shaped groove which are correspondingly arranged.

5. A robot joint torque feedback assembly according to claim 1, wherein said shape changing component comprises:

the stress end is connected with the first joint;

the fixed end is connected with the second joint; and

6. The robot joint torque feedback assembly of claim 5, wherein any one of the ribs defines a kidney-shaped aperture; the strain gauges are arranged on one side or two sides of the waist-shaped hole.

7. A robot joint moment feedback assembly as claimed in claim 6, wherein said force bearing end has a plurality of second attachment holes formed in an axial direction thereof, and said shape-changing member is connected to the first joint through the second attachment holes.

8. A robot joint moment feedback assembly as claimed in claim 7, wherein said fixed end has a plurality of third connecting holes formed in a radial direction thereof, and said shape-changing member is connected to the second joint through the third connecting holes.

9. A robot joint moment feedback assembly according to claim 8, wherein said second joint is provided with a sinking platform, said sinking platform being provided with a fourth connection hole corresponding to said third connection hole; the second joint penetrates through a third connecting hole and a fourth connecting hole which are correspondingly arranged through a fixing piece to be connected with the deformation component;

10. A multi-axis robot comprising a robot joint torque feedback assembly as claimed in any one of claims 1 to 9.