CN214560883U

CN214560883U - Joint torque sensor and robot joint

Info

Publication number: CN214560883U
Application number: CN202120267310.5U
Authority: CN
Inventors: 任少雄; 孙恺
Original assignee: Suzhou Elite Robot Co Ltd
Current assignee: Suzhou Elite Robot Co Ltd
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2021-11-02
Anticipated expiration: 2031-01-29

Abstract

The utility model relates to a joint torque sensor and robot joint, joint torque sensor includes inner circle, outer lane and connection two at least measuring beam and two at least supporting beam of inner circle and outer lane, measuring beam pastes and has the foil gage, a supporting beam is used for the reinforcing joint torque sensor's rigidity, one of them is the input connection ring flange in inner circle and outer lane, and wherein another is the output connection ring flange, a supporting beam's quantity is more than or equal to measuring beam's quantity, adjacent be provided with at least one supporting beam between the measuring beam. The utility model has the advantages that: the joint torque sensor has compact structure, high precision and strong overload resistance.

Description

Joint torque sensor and robot joint

Technical Field

The utility model relates to an industrial robot field especially relates to a joint torque sensor and robot joint.

Background

Industrial robots are a type of robots widely used in industrial environments, and generally, industrial robots can be divided into conventional industrial robots and novel cooperative robots, and compared with conventional industrial robots, the novel cooperative robots have the advantages of light dead weight, small size, good usability and the like, and are therefore suitable for being applied to more scenes, such as industry, service industry, catering industry and the like.

The industrial robot can be connected with the end effector to execute a work task, teaching guidance is needed before the robot executes the work task, and teaching modes of the robot can be generally divided into direct teaching and traditional teaching modes. Traditional teaching mode mainly relies on the demonstrator, and this kind of teaching mode work efficiency is low, and the process is loaded down with trivial details not directly perceived, and is higher to operating personnel knowledge level requirement, compares under, adopts direct teaching mode more directly perceived, and to the greatly reduced that operating personnel required. Zero force control is a key technology for realizing a direct teaching control scheme, and the core of the zero force control is to convert the magnitude and the direction of an external force into corresponding position instructions. The external force detection generally has two modes, one is to adopt current feedback, and the other is to adopt a torque sensor for detection. Compared with a current detection mode, the torque sensor does not need to estimate the joint torque, and can directly measure the real-time output torque of each joint, so that the problem of difficulty in identification of dynamics modeling parameters is directly avoided, and the problems of noise interference, time delay and the like introduced into a dynamics equation are also avoided. Meanwhile, the torque sensor is also very suitable for complex assembly operation based on torque detection and operation industries of contact man-machine cooperation such as the medical industry and the like. The joint torque sensor can accurately control each joint torque of the robot, and the torque sensor is arranged on the joint of the robot to cooperatively complete the work of a complex scene, which is a necessary trend for realizing man-machine integration.

At present, some manufacturers in the field of industrial robots have started to apply torque sensors to robot joints, but the traditional torque sensors are single in structure, large in volume and weight and low in precision, and are difficult to meet the requirements of small size, high precision and compact structure under the current scene of universal modular design of industrial robots.

Therefore, it is necessary to design a joint torque sensor and a robot joint having a compact structure and high accuracy.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model aims at providing a compact structure, joint torque sensor and robot joint that precision is high.

The utility model discloses can adopt following technical scheme: the utility model provides a joint torque sensor, includes inner circle, outer lane and connects two at least measuring beam and two at least supporting beams of inner circle and outer lane, measuring beam pastes and has the foil gage, one of them is the input connection ring flange in inner circle and outer lane, and wherein another is the output connection ring flange, supporting beam's quantity is more than or equal to measuring beam's quantity, and is adjacent be provided with at least one supporting beam between the measuring beam.

Further, along the axial direction of the joint torque sensor, the height of the support beam is greater than the height of the measuring beam.

Further, the torque sensor is a three-dimensional torque sensor, and the torque sensor is used for detecting bending moment and torque.

Further, the torque sensor is used for calibrating the torque according to the bending moment at least in part and outputting the torque calibrated according to the bending moment.

Furthermore, a groove is formed in the outer ring corresponding to the position where the measuring beam is connected, and the groove is formed along the outer edge of the outer ring.

Further, in the axial direction of the joint torque sensor, the upper and lower surfaces of the measuring beam are recessed with respect to the inner ring.

Further, the torque sensor comprises an overload protection beam extending from the outer ring to the inner ring, and a gap is formed between the overload protection beam and the inner ring.

Further, the measuring beam is formed as a plate-shaped beam, which is arranged parallel to the horizontal plane.

Furthermore, the at least two measuring beams are centrosymmetric relative to the joint torque sensor, shear strain gauges are symmetrically adhered to the upper surface and the lower surface of each measuring beam, and the adhered strain gauges of the at least two measuring beams are centrosymmetric relative to the joint torque sensor.

Further, the support beam is formed as a plate-like beam, the measuring beam is formed as a plate-like beam, and the support beam and the measuring beam are perpendicular.

Further, the inner ring comprises a plurality of locking holes distributed along the circumferential direction of the outer edge, and the overload protection beam is arranged between adjacent locking holes and forms a gap with the adjacent locking holes respectively.

Further, the outer ring comprises a connecting hole extending along the radial direction, and the connecting hole is formed at a corresponding position of the outer ring where the overload protection beam is arranged.

The utility model discloses still can adopt following technical scheme: a robot joint comprising a housing, a motor, a speed reducer, and a joint torque sensor as claimed in any preceding claim, the input connection flange being connected to an output of the speed reducer, the output connection flange being for connection to a housing of another joint of the robot to transfer force/torque at the output of the speed reducer to the other joint.

Compared with the prior art, the utility model discloses embodiment's beneficial effect does: the joint torque sensor comprises an input connecting flange plate and an output connecting flange plate, can be used as an output flange of a joint, and meanwhile, the rigidity is better on the premise of keeping the precision of the joint torque sensor by reasonably distributing the supporting beams and the measuring beams and adjusting the size setting of the supporting beams and the measuring beams.

Drawings

Above the utility model discloses an aim at, technical scheme and beneficial effect can realize through following attached drawing:

FIG. 1 is a schematic view of a joint torque sensor according to an embodiment of the present invention

FIG. 2 is a schematic diagram of the tilt of the joint torque sensor shown in the embodiment of FIG. 1

FIG. 3 is a schematic view of a joint torque sensor according to another embodiment of the present invention

FIG. 4 is a schematic diagram of the joint torque sensor of the embodiment of FIG. 3 with strain gauges attached

Fig. 5 is a schematic view of a robot joint according to an embodiment of the present invention

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The terms "upper", "lower", "left" and "right" are used for describing the relative positions of the structures in the drawings, and are not used to limit the scope of the present invention, and the relative relationship between the structures may be changed or adjusted without substantial technical changes.

The utility model provides a joint torque sensor, refer to fig. 1-2, fig. 1 is exemplary gives the utility model discloses a joint torque sensor 100's of an embodiment schematic diagram, joint torque sensor 100 include inner circle 1, outer lane 2 and connection at least two measuring beam 3 and two at least supporting beam 4 of inner circle 1 and outer lane 2, measuring beam 3 pastes and has the foil gage, one of them is the input connection ring flange in inner circle 1 and outer lane 2, wherein another is the output connection ring flange, supporting beam 4's quantity is more than or equal to measuring beam 3's quantity, it is adjacent be provided with at least one supporting beam 4 between the measuring beam 3. Preferably, the inner ring 1 is an input connecting flange, the outer ring 2 is an output connecting flange, and the input connecting flange can receive force/torque and transmit the force/torque to the next joint through the output flange connecting disk. Specifically, the robot joint is connected with the joint torque sensor 100 and can accurately detect the torque output of the joint so that the robot can face various complex use scenes and accurately control the motion of the robot, the power of the robot joint is transmitted by the output flange, the output flange and the torque sensor 100 are simultaneously installed on the joint in the traditional technology to obtain the torque output of the joint, but the joint is required to have a larger installation space to meet the installation requirement of the torque sensor 100, in the prior art, some robots, especially cooperative robots, are required to have a compact structure, the requirement for simultaneously installing the output flange and the torque sensor cannot be met in some scenes, the distance between the output end of the speed reducer and the joint shell is smaller, and great challenges are brought to the design of the torque sensor. And the utility model provides a joint torque sensor can only replace the output flange with joint torque sensor 100, and this joint torque sensor 100 can enough detect joint torque information, can provide the function of original output flange again, and compact structure need not the body structure of redesign robot. On the other hand, the joint torque sensor 100 comprises a support beam and a measuring beam, wherein the measuring beam 3 can be deformed under stress to detect torque, the support beam 4 provides a supporting function for the joint torque sensor 100, the joint torque sensor 100 comprises at least two support beams 4, the number of the support beams 4 is at least equal to that of the measuring beams 3, and the support beams 4 are arranged between the adjacent measuring beams 3 to ensure the rigidity of the joint torque sensor 100. The joint torque sensor 100 integrates functions of a joint output flange and the torque sensor 100, the structure is compact, and the design of the supporting beam 4 enables the rigidity of the joint torque sensor 100 to be good.

The joint torque sensor 100 includes a support beam 4 and a measuring beam 3, the measuring beam 3 is used for being deformed by force to detect torque information, and the support beam 4 is mainly used for enabling the joint torque sensor 100 to have proper rigidity. For the measuring beam 3, in order to ensure the detection sensitivity of the joint torque sensor 100, the rigidity thereof needs to be properly sacrificed, and the rigidity of the joint torque sensor 100 is also reasonable when the joint torque sensor 100 is used as an output flange. On one hand, the number of the support beams 4 is larger than or equal to that of the measuring beams 3, and at least one support beam 4 is arranged between the adjacent measuring beams 3, so that the distribution of the support beams 4 can meet the requirement of the rigidity of the joint torque sensor 100 as much as possible; on the other hand, the support beam 4 and the measuring beam 3 are different in size so that the rigidity of the support beam 4 meets the requirements of the joint moment sensor 100 as much as possible. Specifically, a coordinate system is established with the center of the joint torque sensor 100 as a coordinate origin, the axial direction of the joint torque sensor 100 is a Z-axis direction, and the corresponding direction perpendicular to the Z-axis direction is an X, Y-axis direction, the joint torque sensor 100 is configured to output torque information, that is, detection information of Mz, appropriately reduce the height of the measuring beam 3 to facilitate increasing the sensitivity of the measuring beam 3, and the height of the supporting beam 4 is greater than the height of the measuring beam 3, so that the rigidity of the supporting beam 4 at least in the Mx and My directions is better. That is, the support beam 4 and the measuring beam 3 are different in size so that the support beam 4 is rigid at least in the Mx and My directions, and specifically, the height of the support beam 4 is greater than the height of the measuring beam.

In an embodiment of the present invention, the joint torque sensor 100 is a three-dimensional torque sensor 100, the torque sensor 100 is used for detecting a bending moment and a torque, and further, the torque sensor 100 is used for detecting a bending moment born by a joint output torque and a joint, that is, the torque sensor 100 is used for detecting Mx, My, and Mz. The joint torque sensor can replace an output flange of a joint, can detect bending moment born by the joint, and confirms the deformation condition of the joint so as to obtain the position output of the joint robot with higher precision. Further, the utility model provides a joint torque sensor 100 replaces original joint output flange, and this joint torque sensor 100 is also like traditional joint output flange, can receive Mx, My, Mz's moment at least, and the torque sensor of the joint installation among the prior art does not direct contact joint, joint torque sensor 100 in the utility model and joint direct contact, consequently can receive Mx, My, Mz's moment. The joint torque sensor 100 is a three-dimensional torque sensor 100, so that information of Mx, My, and Mz can be detected, and compared with the prior art in which a conventional torque sensor and an output flange are separately installed, the joint torque sensor 100 in the solution can detect information of Mx and My, so that at least part of Mz can be decoupled according to the information of Mx and My, and detection accuracy of Mz can be improved. That is, the joint torque sensor 100 is used to calibrate the torque at least partially based on the bending moment, and therefore, the deformation amount of the joint can be calculated from the torque information of Mx and My, and the deformation amounts in the three rotational directions of the entire robot can be further obtained, thereby improving the absolute positioning accuracy of the robot. Furthermore, the comprehensive precision of the robot in the Mz direction can be further improved by decoupling at least part of Mz according to the moment information of Mx and My and the information of Mx and My by a calibration means.

The joint torque sensor 100 comprises a measuring beam 3 and a supporting beam 4, wherein the measuring beam 3 is connected with the outer ring 2 and the inner ring 1, the supporting beam 4 is connected with the outer ring 2 and the inner ring 1, and the measuring beam 3 and the supporting beam 4 are distributed along the circumferential direction of the joint torque sensor 100. The utility model discloses an embodiment, the survey beam 3 with it is the platelike roof beam to prop up supporting beam 4, and is adjacent be provided with at least one supporting beam 4 between the survey beam 3, preferably, the thickness of survey beam 3 with it is unanimous to prop up supporting beam 4's thickness, or thickness between them is comparatively close, and this moment this joint torque sensor 100's rigidity and sensitivity's performance all keep better level this moment.

In another embodiment of the present invention, referring to fig. 3, the measuring beam 3 is formed as a plate-shaped beam, the plate-shaped beam is arranged parallel to the horizontal plane, the supporting beam 4 is formed as a plate-shaped beam, the supporting beam 4 is arranged perpendicular to the horizontal plane, i.e. the supporting beam 4 and the measuring beam 3 are arranged perpendicular to each other. Since the joint torque sensor 100 of the robot joint is mainly subjected to a torsional force by arranging the support beam as a plate-shaped beam perpendicular to the horizontal plane, the joint torque sensor 100 needs to have reasonable rigidity in the torque direction, and the support beam 4 is arranged as a plate-shaped beam perpendicular to the horizontal plane, so that the rigidity of the joint torque sensor 100 in each direction can be reasonably adjusted, and the rigidity of the joint torque sensor 100 is in a proper range. Meanwhile, the measuring beam 3 is a plate-shaped beam parallel to the horizontal plane, and multiple simulation tests show that the design is convenient for measuring the sensitive stress of the beam, and the detection precision of the joint torque sensor is good.

Further, referring to fig. 4, fig. 4 shows a schematic diagram of a strain gauge 31 patch of the joint torque sensor 100 according to an embodiment of the present invention. The joint torque sensor comprises at least two measuring beams, the at least two measuring beams are centrosymmetric relative to the joint torque sensor, strain gauges 31 are symmetrically adhered to the upper surface and the lower surface of the measuring beam 3, and the strain gauges 31 adhered to the at least two measuring beams 3 are centrosymmetric relative to the joint torque sensor. The robot joint detects the torque of the joint through the joint torque sensor, and the interference of the force of other dimensions on the torque detection should be avoided as much as possible, so that the accuracy of the torque output by the joint torque sensor is improved. According to multiple experiments and analysis, for My, Fx and Fz force information, the output of a single shear strain gauge 31 is almost 0, namely the interference caused by the shear strain gauge is negligible; for the force of Mx, the interference effect of Mx can be counteracted by ensuring that the stress on one measuring beam is balanced, namely, the interference of Mx can be counteracted by symmetrically sticking the shear strain gauges 31 on the upper and lower surfaces of the measuring beam; for Fy force, the strain gauges 31 adhered to the at least two measuring beams are centrosymmetric relative to the joint torque sensor, namely the strain gauge 31 of one measuring beam and the strain gauge 31 of the other measuring beam with a phase difference of 180 degrees can form a full-bridge decoupling circuit, so that Fy interference is eliminated, and through the design, the detection precision of the joint torque sensor can be improved, and the detection precision of a robot joint is further improved. Meanwhile, strain gauges are attached to the upper surface and the lower surface of the measuring beam, the measuring beam is a plate-shaped beam parallel to the horizontal plane, and the strain gauges are easy to attach and process. The utility model provides a joint torque sensor 100 can replace the output flange of original joint to can detect articular moment information. The output flange is usually connected to the casing of the joint to transmit the power of the joint, and the joint torque sensor 100 of the present invention can also be used to connect to the casing of the joint, so that the joint torque sensor 100 can be acted by the torque of Mx, My and Mz. The utility model discloses an embodiment, outer lane 2 corresponds the position that measuring beam 3 connects is provided with recess 21, recess 21 follows the outer fringe setting of outer lane 2 is concrete, joint torque sensor 100 includes two at least measuring beams 3, and is corresponding, including two at least recesses 21, recess 21 quantity with measuring beam 3 quantity is unanimous. Specifically, the groove 21 extends along the outer edge of the outer ring 2, and the circumferential extension distance of the groove 21 in the outer ring 2 is greater than the extension distance of the outer ring 2 corresponding to the measuring beam 3. Through setting up above-mentioned recess 21, when joint torque sensor 100 installs in the robot joint, the uneven phenomenon of atress probably appears when can not laminating the installation completely, and recess 21's setting is avoided when this joint torque sensor 100 atress is uneven, and the measuring result of a certain measuring beam 3 is skew actual value by a wide margin for this joint torque sensor 100's job stabilization detects comparatively accurately.

In order to avoid the joint torque sensor 100 from being inaccurate in detection result due to uneven stress as much as possible, in another embodiment of the present invention, along the axial direction of the joint torque sensor 100, the upper and lower surfaces of the measuring beam 3 form a recess relative to the inner ring 1, so that when a gap exists between the upper and lower sides of the joint torque sensor 100, the axial stress imbalance of the joint torque sensor can be avoided due to the recessed design; and when the friction in the circumferential direction of the joint torque sensor is uneven, the circumferential stress of the joint torque sensor can be prevented from being unbalanced by the aid of the concave design, and the detection result of one measuring beam 3 is prevented from deviating from an actual value greatly by the aid of the concave design, so that the joint torque sensor is stable in work and accurate in detection.

In an embodiment of the present invention, the wall thickness of the outer ring 2 corresponding to the measuring beam 3 is smaller than the wall thickness of the outer ring 2 corresponding to the supporting beam 4. Namely, the outer ring 2 has a slightly smaller wall thickness corresponding to the position of the measuring beam 3, and the outer ring 2 has a slightly larger wall thickness corresponding to the position of the supporting beam 4. The wall thickness of the outer ring 2 corresponding to the measuring beam 3 is small, and when the positions of the inner ring 1 and the outer ring 2 are determined, the length of the measuring beam 3 is slightly increased, the length of the measuring beam 3 is larger than that of the supporting beam 4, the deformation of the measuring beam 3 is facilitated, the sensitivity of the measuring beam 3 is increased, the strain gauge is pasted to the measuring beam, and the space for pasting the strain gauge is increased. Further, the length of the measuring beam 3 is greater than that of the supporting beam 4, and the length of the measuring beam 3 is less than twice that of the supporting beam 4, that is, the length of the measuring beam 3 is greater than that of the supporting beam 4, but less than twice that of the supporting beam 4, so that the sensitivity of the measuring beam 3 is improved, and the compact design of the robot joint is facilitated.

As mentioned earlier, this joint torque sensor 100 can regard as the output flange to use, because its function that needs to exert torque sensor 100 simultaneously, compare in traditional output flange, output flange self is solid design, and the rigidity is better, can have better supporting effect, and the utility model provides a joint torque sensor 100 need exert the function of detection moment, and this joint torque sensor 100's a supporting beam 4, measuring beam 3 have the supporting role, and is not solid construction between outer lane 2 and the inner circle 1, and the supporting effect is limited. In an embodiment of the present invention, the joint torque sensor 100 includes an overload protection beam 5 extending from the outer ring 2 to the inner ring 1, and the overload protection beam 5 forms a gap with the inner ring 1. By providing the gap, when the torque sensor 100 is overloaded, the overload can be at least partially relieved by the gap, and the damage to the torque sensor 100 can be avoided. Further, the inner ring 1 includes a plurality of locking holes 11 distributed along the circumferential direction of the outer edge, and the overload protection beam 5 is disposed between adjacent locking holes 11 and forms a gap with the adjacent locking holes 11, respectively. That is, a gap is formed between the overload protection beam 5 and the inner ring 1, a gap is formed between the overload protection beam and the locking hole 11 distributed on the outer edge of the inner ring 1 and adjacent to the overload protection beam 5, and a gap of three surfaces is formed between the overload protection beam 5 and the outer edge of the inner ring 1 and between the overload protection beam and the adjacent locking hole 11, so that the overload protection effect of the joint torque sensor 100 is further enhanced.

Furthermore, the inner ring comprises a plurality of locking holes distributed along the circumferential direction of the outer edge, the supporting beams are arranged between the adjacent locking holes, and the supporting beams arranged between the adjacent locking holes form gaps with the adjacent locking holes so as to further enhance the overload protection effect of the joint torque sensor. Furthermore, more than one supporting beam can be arranged between the adjacent locking holes, and gaps are formed between the whole supporting beams positioned between the adjacent locking holes and the adjacent locking holes so as to enhance the overload protection effect of the joint torque sensor.

This joint torque sensor 100 is used for connecting in articular shell, in the utility model discloses an embodiment, outer lane 2 includes along radially extending's connecting hole 22, connecting hole 22 is formed in outer lane 2 sets up the corresponding position of overload protection roof beam 5. A gap exists between the overload protection beam 5 and the inner ring 1, so that when the joint torque sensor 100 is connected, the joint torque sensor 100 is prevented from being stressed unevenly due to the connection pretightening force, the joint torque sensor is prevented from being detected inaccurately, the joint torque sensor can be connected to the next joint through a connecting hole, and the joint torque sensor in the embodiment can be connected to the next joint through the radially extending connecting hole. In other embodiments of the present invention, the connecting hole may also take other forms, for example, the outer ring includes a connecting hole extending along the axial direction, the connecting hole is distributed along the circumferential direction of the outer ring, and the joint torque sensor is connected to the next joint through the connecting hole extending along the axial direction.

The beneficial effects of the above preferred embodiment are: the joint torque sensor comprises an input connecting flange plate and an output connecting flange plate, so that the output flange of the joint can be directly replaced, the torque information can be detected simultaneously, and meanwhile, the rigidity is better on the premise of keeping the accuracy of the joint torque sensor by reasonably distributing the supporting beam 4 and the measuring beam 3 and adjusting the size setting of the supporting beam and the measuring beam.

The utility model discloses still protect a robot joint, refer to fig. 5, robot joint 200 includes shell 210, motor, reduction gear, and any one in the preceding joint torque sensor 100, joint torque sensor 100's input connection flange connect in the output of reduction gear, the output connection flange be used for connect in another joint of robot with will the power/moment transmission of reduction gear output extremely another joint. The motor shaft of the motor is connected to the input end of the speed reducer, the input end of the speed reducer is a high-speed end, the output end of the speed reducer is a low-speed end, the output end of the speed reducer is connected to the joint torque sensor 100, and the joint torque sensor 100 transmits the force/torque at the output end of the speed reducer to the next joint. The joint torque sensor 100 comprises a plurality of locking holes 11 circumferentially distributed on the outer edge of the inner ring 1, and the joint torque sensor 100 is connected to the output end of the speed reducer through the locking holes 11.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. The utility model provides a joint torque sensor, its characterized in that includes inner circle, outer lane, and connects at least two measuring beam and two at least supporting beams of inner circle and outer lane, measuring beam pastes and has the foil gage, a supporting beam is used for the reinforcing joint torque sensor's rigidity, one of them is the input connection ring flange in inner circle and outer lane, and wherein another is the output connection ring flange, supporting beam's quantity is more than or equal to measuring beam's quantity, and is adjacent be provided with at least one supporting beam between the measuring beam.

2. The joint torque sensor according to claim 1, wherein a height of the support beam is greater than a height of the measuring beam in an axial direction of the joint torque sensor.

3. The joint torque sensor according to claim 1, wherein the joint torque sensor is a three-dimensional torque sensor for detecting bending moment and torque.

4. The joint torque sensor according to claim 3, wherein the joint torque sensor is configured to calibrate the torque at least partially according to the bending moment, and output the torque calibrated according to the bending moment.

5. The joint torque sensor according to claim 1, wherein a groove is provided at a position of the outer ring corresponding to the connection of the measuring beam, and the groove is provided along an outer edge of the outer ring.

6. The joint torque sensor according to claim 1, wherein the measuring beam is formed as a plate-shaped beam, which is arranged parallel to a horizontal plane.

7. The joint torque sensor according to claim 6, wherein the at least two measuring beams are symmetrical with respect to the center of the joint torque sensor, the upper and lower surfaces of the measuring beams are symmetrically adhered with shear strain gauges, and the strain gauges adhered to the at least two measuring beams are symmetrical with respect to the center of the joint torque sensor.

8. The joint torque sensor according to claim 1, wherein the joint torque sensor includes an overload protection beam extending along the outer ring toward the inner ring, the overload protection beam forming a gap with the inner ring.

9. The joint torque sensor according to claim 8, wherein the inner race includes a plurality of locking holes circumferentially distributed along an outer periphery, and the overload protection beam is disposed between and forms a gap with the adjacent locking holes, respectively.

10. A robot joint, characterized in that it comprises a housing, a motor, a reducer, and a joint torque sensor according to any of claims 1-9, the input connection flange being connected to the output of the reducer, the output connection flange being intended to be connected to the housing of another joint of the robot to transmit the force/torque of the reducer output to said other joint.