CN111113476A

CN111113476A - Joint structure and robot

Info

Publication number: CN111113476A
Application number: CN201911418174.9A
Authority: CN
Inventors: 李康; 赵明国; 李海雷; 张伟宁; 贺小玉; 张志华; 黑光军; 熊友军
Original assignee: Shenzhen Ubtech Technology Co ltd
Current assignee: Shenzhen Ubtech Technology Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-05-08

Abstract

The present application belongs to the technical field of humanoid service robots, and relates to a joint structure and a robot having the joint structure. The joint structure adopts a motor assembly, a reducer, a torque sensor and a drive circuit board assembly. The motor casing is used as a fixed end. The drive circuit board assembly controls the work of the motor assembly. The motor shaft of the motor assembly outputs the power to the reducer, allowing the output to rotate. . The torque sensor is installed between the motor casing and the reducer. The torque of the output part acts on the torque sensor through the reducer. The torque detected by the torque sensor is the torque of the output part. The intermediate transmission link is not considered during detection, which is more accurate and reliable. Reliable and effective, ensuring system rigidity and stability. The joint structure has the characteristics of strong versatility, high integration and modular structure design. The above joint structure is applied to the robot, and torque feedback is realized at each joint, which can achieve a more precise force control effect and ensure the rigidity and stability of the system.

Description

Joint structure and robot

Technical Field

The application belongs to the technical field of humanoid service robots and relates to a joint structure and a robot with the joint structure.

Background

In the robot field, the robot with force perception has more advantages than the robot with simple position control: for example, the cooperative mechanical arm and a person complete a task together, and the robot stops when touching, so that the safety of the person is ensured; the force control mode also allows the robot to do more delicate work, such as surface grinding, deburring, flexible assembly, and the like; dragging teaching can be realized, and the development period is greatly shortened; of course, more important is that the force control can optimize the motion state of the robot.

At present, a six-dimensional force/torque sensor is usually arranged at the tail end of a mechanical arm to directly obtain the acting force of the external environment, but the force detection of the whole body cannot be carried out. Joint force feedback mainly includes methods of current detection, series connection of an elastic driver (SEA), a force sensor and the like. The current detection method is limited in the complexity of a friction model of a joint transmission link, and the relation between the motor current and the joint output torque cannot be accurately established due to the large difference of the back-drive characteristics of different transmission mechanisms; in the SEA method, an elastic link is introduced into a transmission system, so that the rigidity of the system is reduced, the control difficulty is increased, and even the stability of the system is influenced.

Disclosure of Invention

The application aims to provide a joint structure to solve the technical problems that the existing joint structure cannot accurately establish the relationship between the current of a motor and the output torque of a joint, the rigidity of a system is reduced, and the stability of the system is influenced.

An embodiment of the present application provides a joint structure, including:

an output member;

the motor assembly is used for providing power and comprises a motor shell and a motor shaft which is rotatably arranged on the motor shell;

a speed reducer connected between the motor shaft and the output member;

the torque sensor is used for detecting the torque borne by the output piece and is arranged between the motor shell and the speed reducer; and

and the driving circuit board assembly is electrically connected with the motor assembly.

Optionally, the output member is a hollow tube, the motor shaft is a hollow shaft, and the hollow tube penetrates through the inside of the hollow shaft.

Optionally, the motor housing is fixedly connected with a rear cover, one end of the output member is fixed to the output end of the speed reducer, and the other end of the output member is supported by the rear cover.

Optionally, the motor assembly further includes a motor stator fixed in the motor housing, a motor rotor fixed on the motor shaft and matched with the motor stator, and a motor end cover mounted on the motor housing, wherein one end of the motor shaft is supported on the motor housing through a first bearing, and the other end of the motor shaft is supported on the motor end cover through a second bearing.

Optionally, the speed reducer is any one of a harmonic speed reducer, a worm gear speed reducer, a planetary speed reducer, or a cycloidal pin speed reducer.

Optionally, the speed reducer is a harmonic speed reducer, the harmonic speed reducer includes a rigid gear having an inner gear ring, a wave generator driven by the motor assembly, and a flexible gear having a cylindrical portion and an annular portion, the annular portion is formed by extending from an edge of one end of the cylindrical portion, the cylindrical portion is sleeved outside the wave generator, and an outer gear ring engaged with the inner gear ring is disposed on an outer side surface of the cylindrical portion; the harmonic reducer further includes a support bearing for supporting the rigid wheel to the annular portion; and the rigid wheel is used as the output end of the harmonic speed reducer.

Optionally, the torque sensor includes a substrate and an inductive element mounted on the substrate; the substrate comprises an inner ring part, an outer ring part positioned outside the inner ring part and a sensitive beam connected between the inner ring part and the outer ring part, and the sensing element is arranged on the sensitive beam; the inner ring portion is fixed to the motor housing, and the outer ring portion is fixed to the speed reducer.

Optionally, at least two through grooves are circumferentially distributed on the substrate, each through groove comprises an arc-shaped through groove and two radial through grooves respectively communicated with two ends of the arc-shaped through groove, and the sensitive beam is formed in an area between two adjacent radial through grooves in the two adjacent through grooves on the substrate.

Optionally, the torque sensor is a strain gauge type torque sensor, a magnetoelastic type torque sensor, a photoelectric type torque sensor, or a capacitive type torque sensor.

Optionally, the driving circuit board assembly is disposed at a position where the motor housing deviates from the torque sensor, and cables of the torque sensor sequentially penetrate through the motor housing and then are electrically connected to the driving circuit board assembly.

Optionally, the joint structure further comprises a motor end position feedback assembly for detecting a rotational position of the motor shaft and/or an output end position feedback assembly for detecting a rotational position of the output member.

Optionally, the motor end position feedback component is the same as or different from the output end position feedback component, and is one of a photoelectric encoder, a magnetic encoder, a capacitive encoder, a rotary transformer, and a potentiometer.

Optionally, the driving circuit board assembly includes a driving board disposed at an interval with the motor housing, a circuit protection board disposed between the driving board and the motor housing and used for preventing electromagnetic interference, a supporting column connected between the motor housing and the circuit protection board, and an insulating column connected between the driving board and the circuit protection board.

One or more technical solutions in the joint structure provided by the present application have at least one of the following technical effects: the joint structure adopts a motor assembly, a speed reducer, a torque sensor and a driving circuit board assembly, a motor shell serves as a fixed end, the driving circuit board assembly controls the motor assembly to work, and a motor shaft of the motor assembly outputs power to the speed reducer to enable an output part to output and rotate. The torque sensor is arranged between the motor shell and the speed reducer, the torque applied to the output piece acts on the torque sensor through the speed reducer, the detection torque of the torque sensor is the torque applied to the output piece, an intermediate transmission link is not required to be considered during detection, the method is more accurate, reliable and effective, and the rigidity and the stability of the system are ensured. The joint structure has the characteristics of strong universality, high integration level and modularized structural design, and avoids the complexity of a friction model of a joint transmission link when the existing current detection method is adopted, so that the relation between the motor current and the joint output torque can be accurately established, and the condition that the rigidity of a system is reduced due to the introduction of an elastic link by adopting the existing SEA method is also avoided.

The embodiment of the application provides a robot, which comprises the joint structure.

One or more technical solutions in the robot provided by the present application have at least one of the following technical effects: the joint structure is applied to the robot, torque feedback is realized at each joint, more accurate force control effect can be realized, and the rigidity and stability of the system are ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a side view of a joint structure provided by an embodiment of the present application;

FIG. 2 is a cross-sectional view taken along line A-A of the articulating structure of FIG. 1;

FIG. 3 is a side view of a motor assembly employed in the joint structure of FIG. 2;

FIG. 4 is a cross-sectional view of the motor assembly of FIG. 3 taken along line B-B;

FIG. 5 is an exploded perspective view of a motor assembly and a motor end position feedback assembly employed in the joint structure of FIG. 2;

FIG. 6 is a cross-sectional view of a reducer used in the joint structure of FIG. 2;

FIG. 7 is an exploded perspective view of the reducer of FIG. 6;

FIG. 8 is a front view of a torque sensor employed in the joint structure of FIG. 2;

FIG. 9 is an exploded perspective view of a drive circuit board assembly employed in the joint structure of FIG. 2;

FIG. 10 is an exploded perspective view of an output end position feedback assembly employed in the articulating structure of FIG. 2;

fig. 11 is a perspective structural view of a robot provided in an embodiment of the present application;

fig. 12 is a perspective view of a robot according to another embodiment of the present application

Fig. 13 is a perspective view of a robot according to another embodiment of the present application.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In the description of the embodiments of the present application, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like refer to orientations and positional relationships illustrated in the drawings, which are used for convenience in describing the embodiments of the present application and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the embodiments of the present application.

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

In the embodiments of the present application, unless otherwise specifically stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

Referring to fig. 1 and 2, an embodiment of the present application provides a joint structure, which can be applied to a joint of a robot or a joint connection of another device, and can drive the joint to rotate and achieve torque detection at the joint. The joint structure comprises an output member 10, a motor assembly 20, a speed reducer 30, a torque sensor 40 and a driving circuit board assembly 50. The motor assembly 20 is used for providing power, and the motor assembly 20 includes a motor housing 21 and a motor shaft 22 rotatably mounted on the motor housing 21. The speed reducer 30 is connected between the motor shaft 22 and the output member 10, and is configured to convert power of the motor assembly 20 to the speed reducer 30, and to rotate the output end of the speed reducer 30 at a low speed and output a large torque. The torque sensor 40 is used for detecting the torque applied to the output member 10, and the torque sensor 40 is disposed between the motor housing 21 and the speed reducer 30. The driving circuit board assembly 50 is electrically connected to the motor assembly 20 for controlling the operation of the motor assembly 20.

The joint structure adopts the motor assembly 20, the speed reducer 30, the torque sensor 40 and the driving circuit board assembly 50, the motor shell 21 is used as a fixed end, the driving circuit board assembly 50 controls the motor assembly 20 to work, and the motor shaft 22 of the motor assembly 20 outputs power to the speed reducer 30 to enable the output part 10 to output rotation. The torque sensor 40 is arranged between the motor shell 21 and the speed reducer 30, the torque applied to the output part 10 acts on the torque sensor 40 through the speed reducer 30, the detection torque of the torque sensor 40 is the torque applied to the output part 10, an intermediate transmission link is not required to be considered during detection, the method is more accurate, reliable and effective, and the rigidity and stability of the system are ensured. The joint structure has the characteristics of strong universality, high integration level and modularized structural design, and avoids the complexity of a friction model of a joint transmission link when the existing current detection method is adopted, so that the relation between the motor current and the joint output torque can be accurately established, and the condition that the rigidity of a system is reduced due to the introduction of an elastic link by adopting the existing SEA method is also avoided.

Specifically, the torque detected by the torque sensor 40 is a torque around a direction perpendicular to the rotation axis of the output member 10, the speed reducer 30 and the torque sensor 40 are sequentially connected, the torque applied to the output member 10 acts on the torque sensor 40 through the speed reducer 30, and the torque detected by the torque sensor 40 is the torque applied to the output member 10.

Referring to fig. 3 to 5, in another embodiment of the present application, the motor housing 21 has a mounting flange 211, and the mounting flange 211 has a mounting hole 2111 for mounting the motor housing 21 to a structural member by a fastener.

Referring to fig. 1 and 2, in another embodiment of the present application, the output member 10 is a hollow tube, the motor shaft 22 is a hollow shaft, and the hollow tube penetrates through the interior of the hollow shaft. The hollow tube is used as the output member 10, and the output member 10 passes through the hollow shaft, so that the cable or other objects can be conveniently arranged in the hollow tube.

In another embodiment of the present application, one end of the hollow pipe close to the speed reducer 30 extends outward to form a connection ring 11 for connecting with the output end of the speed reducer 30, which is easy to assemble. Specifically, the output end of the speed reducer 30 may be fixed to the connection ring 11 of the hollow pipe by a fastener.

In another embodiment of the present application, a rear cover 60 is fixedly connected to the motor housing 21, one end of the output member 10 is fixed to the output end of the speed reducer 30, and the other end of the output member 10 is supported by the rear cover 60. This structure is easy to assemble, can arrange other devices in the back cover 60 to protect it, and allows the whole to be formed into a modular structure, thereby facilitating the application of the joint structure to the joints of the robot. Further, the driving circuit board assembly 50, the motor end position feedback assembly 70 and the output end position feedback assembly 80, which will be described below, can be installed in the rear cover 60, and thus, the assembly is easy and the structure is compact. Specifically, the rear cover 60 can be fixed to the motor end cover 25 described below, and is easily assembled. One end of the output member 10 is supported by the rear cover 60 via a bearing 61, and the friction between the output member 10 and the rear cover 60 is reduced.

Referring to fig. 2 to 5, in another embodiment of the present application, the motor assembly 20 further includes a motor stator 23 fixed in the motor housing 21, a motor rotor 24 fixed on the motor shaft 22 and cooperating with the motor stator 23, and a motor end cover 25 mounted on the motor housing 21, wherein one end of the motor shaft 22 is supported on the motor housing 21 through a first bearing 26, and the other end of the motor shaft 22 is supported on the motor end cover 25 through a second bearing 27. This configuration is easy to assemble, allowing the motor assembly 20 to form a single unit. When the motor stator 23 has a voltage input, the motor rotor 24 rotates the motor shaft 22. Specifically, the first bearing 26 and the second bearing 27 may be rolling bearings, which reduce the friction between the motor shaft 22 and the motor housing 21 and the motor cover 25. Specifically, the motor end cover 25 is provided with a mounting groove 251 for mounting an O-shaped rubber ring 28, and the O-shaped rubber ring 28 is sleeved outside the outer ring of the second bearing 27 to realize radial limiting.

In another embodiment of the present application, the motor assembly 20 may be a split motor, a permanent magnet synchronous motor, a dc brushless motor or other motors, as long as it can output power, and is selected as required.

In another embodiment of the present application, the speed reducer 30 is any one of a harmonic speed reducer, a worm gear speed reducer, a planetary speed reducer, or a cycloidal pin speed reducer. The speed reducer can realize low-speed rotation and large torque output and is specifically arranged as required.

Referring to fig. 2, 6 and 7, in another embodiment of the present application, the speed reducer 30 is a harmonic speed reducer 30, the harmonic speed reducer 30 includes a rigid gear 31 having an inner gear ring 311, a wave generator 32 driven by the motor assembly 20, and a flexible gear 33 having a cylindrical portion 331 and an annular portion 332, the annular portion 332 is formed by extending an edge of one end of the cylindrical portion 331, the cylindrical portion 331 is sleeved outside the wave generator 32, and an outer gear ring 3311 engaged with the inner gear ring 311 is disposed on an outer side surface of the cylindrical portion 331; the harmonic reducer 30 further includes a support bearing 34 for supporting the ring portion 332 with the ring gear 31; the rigid wheel 31 serves as an output end of the harmonic reducer 30. The harmonic speed reducer 30 has the advantages of simple and compact structure, convenient assembly, high speed reduction ratio, small volume and high transmission precision. The motor assembly 20 drives the wave generator 32 to rotate at a high speed and a small torque, the flexible gear 33 is forced to deform under the action of the wave generator 32, the outer gear ring 3311 of the cylindrical part 331 of the flexible gear 33 is meshed with the inner gear ring 311 of the rigid gear 31 for transmission, and the rigid gear 31 is connected to the output member 10 to output at a low speed and a large torque.

In another embodiment of the present application, the annular portion 332 is formed to extend outward from one end edge of the cylindrical portion 331, and this structure is easy to mold, and facilitates supporting the rigid wheel 31 on the annular portion 332 through the support bearing 34. Specifically, an oil seal 343 is provided at the support bearing 34 to prevent leakage of the lubricating oil.

In another embodiment of the present application, the wave generator 32 includes a cam 321 and a flexible bearing 322 disposed outside the cam 321, the cam 321 is driven by the motor assembly 20 to rotate, and the flexible bearing 322 is connected to an inner side surface of the cylindrical portion 331. The radial length of the cam 321 is different, and the flexible bearing 322 is provided between the cylindrical portion 331 and the cam 321. Specifically, under the action of the wave generator 32, the flexible gear 33 is flexibly deformed, two ends of the long shaft of the flexible gear 33 are completely meshed with the rigid gear 31, two ends of the short shaft of the flexible gear 33 are completely separated from the rigid gear 31, and when the wave generator 32 rotates for one circle, the flexible gear 33 rotates for two teeth in opposite directions, so that a large reduction ratio is realized.

Referring to fig. 2, in another embodiment of the present application, the motor shaft 22 is connected to the wave generator 32 through the extension shaft 221, one end of the extension shaft 221 is fixedly connected to the motor shaft 22, and the other end of the extension shaft 221 is fixedly connected to the wave generator 32. The extension shaft 221 is a hollow shaft to facilitate the penetration of the output member 10. Specifically, the extension shaft 221 and the motor shaft 22 can be fixedly connected through the fastener 91, so that the assembly is easy and the connection is firm.

In another embodiment of the present application, the harmonic reducer 30 is configured in a standard type, a flat type, a hollow type, a top hat type, a three-component type, etc., which are all in the prior art, and the specific structure is set as required.

Referring to fig. 2 and 8, in another embodiment of the present application, the torque sensor 40 includes a substrate 41 and a sensing element (not shown) mounted on the substrate 41; the substrate 41 includes an inner ring portion 411, an outer ring portion 412 located outside the inner ring portion 411, and a sensing beam 413 connected between the inner ring portion 411 and the outer ring portion 412, wherein the sensing element is mounted on the sensing beam 413; the inner ring portion 411 is fixed to the motor housing 21, and the outer ring portion 412 is fixed to the speed reducer 30. This solution enables detection of the torque experienced by the output member 10. The inner ring portion 411 of the substrate 41 is fixed to the motor housing 21, the outer ring portion 412 of the substrate 41 is fixed to the speed reducer 30 and the output member 10, the torque applied to the output member 10 acts on the sensitive beam 413 of the torque sensor 40 through the speed reducer 30, the sensing element on the sensitive beam 413 detects deformation, the electric signal of the sensing element is obtained and converted into a torque value, and the detection torque of the torque sensor 40 is the torque applied to the output member 10. Specifically, the sensing element may be a strain gauge, and the strain gauge is attached to the sensitive beam 413 of the substrate 41, so as to detect the deformation of the sensitive beam 413 and further convert the deformation into the received torque.

Further, the motor housing 21 and the inner ring portion 411 of the base plate 41 may be fixedly connected by a fastener 92. When the harmonic reducer 30 is used, the outer ring 342 of the support bearing 34 and the annular portion 332 of the flexspline 33 are fixedly connected to the outer ring portion 412 of the base plate 41, and specifically, the three can be connected by the fastening member 93. The inner ring 341 of the support bearing 34 and the rigid wheel 31 are fixedly connected with the connecting ring 11 of the output member 10, and the three can be connected by fasteners.

In another embodiment of the present application, at least four sensing beams 413 are uniformly distributed on the substrate 41, so that a plurality of sensing elements can be conveniently arranged, and the deformation of the sensing beams 413 can be accurately detected and converted into an accurate moment.

Referring to fig. 8, in another embodiment of the present application, at least two through grooves 414 are circumferentially distributed on the substrate 41, each through groove 414 includes an arc-shaped through groove 4141 and two radial through grooves 4142 respectively communicated with two ends of the arc-shaped through groove 4141, and a sensitive beam 413 is formed in a region between two adjacent radial through grooves 4142 of two adjacent through grooves 414 on the substrate 41. The structure is easy to process, the structures of the inner ring portion 411, the outer ring portion 412 and the sensitive beam 413 are formed, the arc-shaped through groove 4141 is arranged in an extending mode by taking the center of the inner ring portion 411 as the circle center, the sensitive beam 413 is attached with the sensing element to detect the deformation of the sensitive beam 413, and therefore the moment is obtained, and the deformation of the sensitive beam 413 is convenient to detect. Further, the radial through groove 4142 is disposed at the end of the arc through groove 4141 extending to the center of the inner ring portion 411, which is easy to form, and facilitates forming the structures of the inner ring portion 411, the outer ring portion 412 and the sensing beam 413.

In another embodiment of the present application, the torque sensor 40 may be a strain gauge type torque sensor, a magnetoelastic type torque sensor, a photoelectric type torque sensor, or a capacitive type torque sensor or other torque sensors. The torque sensor belongs to the prior art, can realize torque detection and is arranged as required.

Referring to fig. 2, 4 and 5, in another embodiment of the present application, the driving circuit board assembly 50 is disposed at a position of the motor housing 21 away from the torque sensor 40, and the cable of the torque sensor 40 sequentially passes through the motor housing 21 and then is electrically connected to the driving circuit board assembly 50. The moment signal feedback of the moment sensor 40 is realized, and the protection of the cable is realized. Specifically, the motor housing 21 is provided with a cabling channel 212 through which cables pass, facilitating cable assembly. Furthermore, after the cable passes through the motor housing 21, the cable also passes through the motor end cover 25 and is connected with the driving board 51 of the driving circuit board assembly 50, so that the cable connection is facilitated.

Referring to fig. 2-5, in another embodiment of the present application, the joint structure further includes a motor end position feedback assembly 70 for detecting the rotational position of the motor shaft 22. The motor assembly 20 is controlled to rotate at a precise low speed and output a large torque by detecting the rotation position of the motor shaft 22 and feeding back the rotation position to the driving circuit board assembly 50. Specifically, the motor end position feedback assembly 70 may be a multi-turn incremental encoder that accurately detects the rotational position of the motor shaft 22.

In another embodiment of the present application, the motor end position feedback assembly 70 includes a motor encoder reading head 71 disposed on the motor end cover 25 and a motor encoder grating 72 fixed on the motor shaft 22, the motor encoder reading head 71 has a transmitting end and a receiving end, the motor encoder grating 72 is disposed between the transmitting end and the receiving end, and the motor encoder reading head 71 cooperates with the motor encoder grating 72 to realize the motor position feedback. The motor encoder is hollow to facilitate passage of the output member 10.

Referring to fig. 2 and 10, in another embodiment of the present application, the joint structure further includes an output end position feedback assembly 80 for detecting the rotational position of the output member 10. The motor assembly 20 is controlled to rotate at a precise low speed to output a large torque by detecting the rotation position of the output member 10 and feeding back the rotation position to the driving circuit board assembly 50. Specifically, the output end position feedback assembly 80 may employ a single-turn absolute encoder capable of accurately detecting the rotational position of the output member 10.

In another embodiment of the present application, when the motor end position feedback assembly 70 and the output end position feedback assembly 80 are used together, a double feedback is formed, so that the operation of the motor assembly 20 can be controlled more precisely.

In another embodiment of the present application, the output end position feedback assembly 80 includes a mounting seat 81 rotating synchronously with the output member 10, a first position feedback element 82 mounted to the mounting seat 81, a support 83 fixed to the motor housing 21, and a second position feedback element 84 mounted to the support 83 and configured to cooperate with the first position feedback element 82 to detect the position of the output member 10. This solution is easy to assemble and enables detection of the rotational position of the output member 10. When the output member 10 rotates, the second position feedback element 84 is driven to rotate, and the first position feedback element 82 and the second position feedback element 84 cooperate to realize joint position feedback. Specifically, the support 83 is arc-shaped, the support 83 has a plurality of connecting posts 831, the arc-shaped circuit board 85 is mounted on the connecting posts 831, the second position feedback element 84 is mounted on the circuit board 85, and the first position feedback element 82 and the second position feedback element 84 are arranged at intervals to realize rotation position sensing. The support 83 is fixedly connected to the motor end cover 25, so that the assembly is easy and the structure is compact.

In another embodiment of the present application, the first position feedback element 82 may be a magnetic ring, and the second position feedback element 84 is an encoder processing circuit for sensing a change in a magnetic field of the magnetic ring to detect the rotational position.

In another embodiment of the present application, the motor end position feedback assembly 70 is the same as or different from the output end position feedback assembly 80, and is one of a photoelectric encoder, a magnetic encoder, a capacitive encoder, a rotary transformer, and a potentiometer. The components belong to the prior art, can realize the detection of angle positions and are arranged as required.

Referring to fig. 2 and 9, in another embodiment of the present application, the driving circuit board assembly 50 includes a driving board 51 spaced apart from the motor housing 21, a circuit protection board 52 disposed between the driving board 51 and the motor housing 21 and used for preventing electromagnetic interference, a supporting column 53 connected between the motor housing 21 and the circuit protection board 52, and an insulating column 54 connected between the driving board 51 and the circuit protection board 52. This solution is easy to assemble and ensures that the driving plate 51 can work normally to control the operation of the motor assembly 20 and receive the feedback signal. The circuit protection board 52 functions to protect the driving board 51 and prevent electromagnetic interference. Insulation posts 54 are used to provide insulation between motor assembly 20 and drive plate 51. Specifically, the insulating pillars 54 may be nylon pillars. The support column 53 is connected between the motor end cap 25 and the circuit protection board 52, and is easy to assemble. The support posts 53 may be copper posts. The driving circuit board assembly 50 is a hollow structure to realize the hollow wiring of the whole joint. Furthermore, the number of the supporting columns 53 is equal to that of the insulating columns 54, and the supporting columns 53 and the insulating columns 54 are circumferentially arranged on two sides of the circuit protection board 52, so that the assembly is easy, and the connection is firm.

In another embodiment of the present application, there is provided a robot including the joint structure described above. The joint structure is applied to the robot, torque feedback is realized at each joint, more accurate force control effect can be realized, and the rigidity and stability of the system are ensured.

Specifically, the robot may be a multi-degree-of-freedom mechanical arm, a legged robot, a wheeled robot, or the like. The joint structure described above is applicable to any robot having joints.

Referring to fig. 11, in another embodiment of the present application, a robot is a six-dof robot arm 200, and the above joint structure is integrated and applied as each joint of the robot arm.

Referring to fig. 12, in another embodiment of the present application, the robot is a humanoid robot 300, and the joint structure is used as a joint of the humanoid robot 300 for integrated applications, including but not limited to ankle joint, knee joint, hip joint of leg, waist joint of trunk, and shoulder joint, elbow joint, wrist joint in arm, etc.

Referring to fig. 13, in another embodiment of the present application, the robot is a quadruped robot 400, and the joint structure is integrated and applied as a joint of the quadruped robot 400.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.

Claims

1. A joint structure, comprising:

an output member;

a speed reducer connected between the motor shaft and the output member;

2. The joint structure according to claim 1, wherein the output member is a hollow tube, the motor shaft is a hollow shaft, and the hollow tube passes through the inside of the hollow shaft.

3. The joint structure according to claim 1, wherein a rear cover is fixedly attached to the motor housing, one end of the output member is fixed to the output end of the reduction gear unit, and the other end of the output member is supported by the rear cover.

4. The joint structure of claim 1, wherein the motor assembly further comprises a motor stator fixed in the motor housing, a motor rotor fixed on the motor shaft and engaged with the motor stator, and a motor end cover mounted on the motor housing, wherein one end of the motor shaft is supported on the motor housing by a first bearing, and the other end of the motor shaft is supported on the motor end cover by a second bearing.

5. The joint structure according to claim 1, wherein the speed reducer is any one of a harmonic speed reducer, a worm gear speed reducer, a planetary speed reducer, and a cycloidal pin speed reducer.

6. The joint structure according to claim 1, wherein the speed reducer is a harmonic speed reducer including a rigid gear having an inner gear ring, a wave generator driven by the motor assembly, and a flexible gear having a cylindrical portion and an annular portion, the annular portion being formed to extend from an edge of one end of the cylindrical portion, the cylindrical portion being fitted around an outside of the wave generator, an outer gear ring being provided on an outer side surface of the cylindrical portion to be engaged with the inner gear ring; the harmonic reducer further includes a support bearing for supporting the rigid wheel to the annular portion; and the rigid wheel is used as the output end of the harmonic speed reducer.

7. The joint structure of claim 1, wherein the torque sensor comprises a substrate and a sensing element mounted to the substrate; the substrate comprises an inner ring part, an outer ring part positioned outside the inner ring part and a sensitive beam connected between the inner ring part and the outer ring part, and the sensing element is arranged on the sensitive beam; the inner ring portion is fixed to the motor housing, and the outer ring portion is fixed to the speed reducer.

8. The joint structure of claim 7, wherein at least two through grooves are circumferentially distributed on the base plate, each through groove comprises an arc-shaped through groove and two radial through grooves respectively communicated with two ends of the arc-shaped through groove, and the sensitive beam is formed in a region between two adjacent radial through grooves in two adjacent through grooves on the base plate.

9. The joint structure according to claim 1, wherein the torque sensor is a strain gauge type torque sensor, a magnetoelastic type torque sensor, an electro-optical type torque sensor, or a capacitance type torque sensor.

10. The joint structure of claim 1, wherein the driving circuit board assembly is disposed at a position where the motor housing faces away from the torque sensor, and cables of the torque sensor sequentially penetrate through the motor housing and then are electrically connected to the driving circuit board assembly.

11. The joint structure of claim 1, further comprising a motor end position feedback assembly for detecting a rotational position of the motor shaft and/or an output end position feedback assembly for detecting a rotational position of the output member.

12. The joint structure of claim 11, wherein the motor end position feedback assembly is the same as or different from the output end position feedback assembly, and is one of a photoelectric encoder, a magnetic encoder, a capacitive encoder, a rotary transformer, and a potentiometer.

13. The joint structure of claim 1, wherein the driving circuit board assembly includes a driving board disposed apart from the motor housing, a circuit protection board disposed between the driving board and the motor housing and for preventing electromagnetic interference, a supporting column connected between the motor housing and the circuit protection board, and an insulating column connected between the driving board and the circuit protection board.

14. Robot, characterized in that it comprises a joint structure according to any of claims 1 to 13.