CN116408828A

CN116408828A - Robot joint and robot

Info

Publication number: CN116408828A
Application number: CN202111683488.9A
Authority: CN
Inventors: 陈晓强; 吴文镜; 栗园园; 侯澈; 杨高; 甘海宏; 陈文杰
Original assignee: Midea Group Co Ltd; GD Midea Air Conditioning Equipment Co Ltd; KUKA Robotics Guangdong Co Ltd
Current assignee: Midea Group Co Ltd; GD Midea Air Conditioning Equipment Co Ltd; KUKA Robotics Guangdong Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-07-11
Also published as: WO2023124730A1

Abstract

The application discloses robot joint and robot, wherein, the robot joint includes: the motor comprises a motor stator and a motor rotor rotatably arranged on the outer side of the motor stator; the hollow center shaft is fixedly embedded in the motor stator; the rigid gear nest of speed reducer sets up in the motor outside, and fixed the setting in the cavity axis, and the wave generator of speed reducer sets up in motor rotor fixedly to the flexible gear of transmission to the speed reducer. The speed reducer and the motor are nested, the hollow aperture of the hollow center shaft can be relatively enlarged, the heat dissipation area is increased, and the heat dissipation of the motor and the speed reducer is facilitated. And the hollow center shaft and the motor stator keep relative static, so that feedback precision is facilitated to be provided, cables can be directly arranged in the hollow center shaft conveniently, the output and the fixed end of the cables are relatively static, the abrasion of the cables can be reduced, and the service life is prolonged. Because the application adopts the hollow center shaft with large hollow aperture, a fan and an air duct can be arranged, and the heat dissipation efficiency is further improved.

Description

Robot joint and robot

Technical Field

The application belongs to the technical field of driving equipment, and particularly relates to a robot joint and a robot.

Background

Under the demand of assisting a portable robot, the harmonic speed reducer technology is widely applied, and a robot joint module consisting of the harmonic speed reducer, a frameless torque motor, a holding band-type brake and double encoder feedback becomes a main development and struggling target of a plurality of robot designs. In the prior art, the hollow center shaft in the robot joint module has small aperture, which is not beneficial to heat dissipation of a motor and a speed reducer and cable arrangement.

Disclosure of Invention

The application provides a robot joint and robot to solve the cavity axis aperture of robot joint little, be unfavorable for the technical problem of heat dissipation and cable arrangement.

In order to solve the technical problems, one technical scheme adopted by the application is as follows: a robotic joint, comprising: the motor comprises a motor stator and a motor rotor rotationally arranged on the outer side of the motor stator; the hollow center shaft is fixedly embedded in the motor stator; the rigid gear nest of the speed reducer is arranged outside the motor and fixedly arranged on the hollow center shaft, and the wave generator of the speed reducer is fixedly arranged on the motor rotor so as to drive the flexible gear of the speed reducer.

According to one embodiment of the present application, the hollow bottom bracket includes: the middle shaft section is nested and fixed in the motor stator; and the connecting section is connected with the end part of the middle shaft section and extends outwards along the radial direction of the middle shaft section, and the connecting section is connected with the rigid wheel.

According to an embodiment of the present application, the motor rotor includes: the rotor shaft is rotationally nested outside the motor stator; and the output flange is connected with the end part of the rotor shaft and extends inwards along the radial direction of the rotor shaft, and is used for being connected with the wave generator.

According to an embodiment of the application, the wave generator is arranged between the engagement section and the output flange.

According to an embodiment of the present application, there is provided: the first bearing is arranged between the wave generator and the hollow center shaft.

According to an embodiment of the present application, the flexspline includes: the external tooth section is arranged between the wave generator and the rigid wheel; and the transmission section is connected with the end part of the external tooth section and extends outwards along the radial direction of the external tooth section.

According to an embodiment of the present application, there is provided: the fixed mount is nested and arranged on the outer side of the rigid wheel and is fixedly connected with the transmission section; and the crossed roller bearing is arranged between the fixing frame and the rigid wheel.

According to an embodiment of the present application, there is provided: the electromagnetic band-type brake is fixed relative to the transmission section and sleeved on the outer side of the motor rotor; the second bearing is arranged between the electromagnetic band-type brake and the motor rotor.

According to an embodiment of the present application, there is provided: the first encoder is coaxially fixed with the motor rotor; the second encoder is positioned at the outer side of the first encoder and is coaxially fixed with the flexible gear.

According to an embodiment of the present application, the arrangement direction of the first encoder and the second encoder is perpendicular to the axial direction of the motor.

In order to solve the technical problem, another technical scheme adopted by the application is as follows: a robot comprises the robot joint.

The beneficial effects of this application are: by adopting the outer rotor motor and adopting a mode of nesting the speed reducer and the motor, the hollow aperture in the hollow center shaft can be relatively enlarged, the heat dissipation area is increased, and the heat dissipation of the motor and the speed reducer is facilitated. And the hollow center shaft and the motor stator keep relative static, so that feedback precision is facilitated to be provided, cables can be directly arranged in the hollow center shaft conveniently, the output and the fixed end of the cables are relatively static, the abrasion of the cables can be reduced, and the service life is prolonged. Because the application adopts the hollow center shaft with large hollow aperture, a fan and an air duct can be arranged, and the heat dissipation efficiency is further improved.

Drawings

For a clearer description of the technical solutions in the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

FIG. 1 is a schematic perspective cross-sectional view of an embodiment of a robotic joint of the present application;

FIG. 2 is a schematic perspective cross-sectional view of an embodiment of a motor of a robotic joint of the present application;

FIG. 3 is a schematic cross-sectional view of an embodiment of a robotic joint of the present application;

fig. 4 is an exploded view of one embodiment of a robotic joint of the present application.

In the figure: 100. a robot joint; 110. a motor; 111. a motor stator; 112; a motor rotor; 1121. a rotor shaft; 1122. an output flange; 120. a hollow center shaft; 121. a central shaft section; 122. a joining section; 130. a speed reducer; 131. rigid wheel; 132. a flexible wheel; 1321. an outer tooth segment; 1322. a transmission section; 133. a wave generator; 134. crossed roller bearings; 140. a first bearing; 150. a fixing frame; 160. an electromagnetic band-type brake; 170. a second bearing; 181. a first encoder; 182. a second encoder.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

Referring to fig. 1 to 4, fig. 1 is a schematic perspective sectional view of an embodiment of a robot joint according to the present application; FIG. 2 is a schematic perspective cross-sectional view of an embodiment of a motor of a robotic joint of the present application; FIG. 3 is a schematic cross-sectional view of an embodiment of a robotic joint of the present application;

An embodiment of the present application provides a robot joint 100, as shown in fig. 1 to 4, including a motor 110, a hollow center shaft 120, and a speed reducer 130. The motor 110 includes a motor stator 111 and a motor rotor 112 rotatably disposed outside the motor stator 111, and a hollow center shaft 120 is fixedly embedded in the motor stator 111. The rigid gear 131 of the speed reducer 130 is nested outside the motor 110 and fixedly arranged on the hollow center shaft 120, and the wave generator 133 of the speed reducer 130 is fixedly arranged on the motor rotor 112 so as to be driven to the flexible gear 132 of the speed reducer 130. The motor rotor 112 and the motor stator 111 rotate relatively, the motor rotor 112 transmits the rotation to the wave generator 133, the rigid wheel 131 and the motor stator 111 are fixed relatively, the wave generator 133 drives the flexible wheel 132 meshed with the rigid wheel 131 to deform, so that the motion and power are transmitted, and the function of the harmonic speed reducer 130 is realized.

The long-term study of the present inventors shows that the prior art generally adopts an inner rotor frameless motor 110, the motor 110 and a speed reducer 130 are connected in series in the axial direction, the arrangement limits the inner diameter of the hollow center shaft 120, and the dimension of the robot joint 100 in the axial direction is larger.

Because the motor 110 in the application adopts the outer rotor motor 110, that is, the motor rotor 112 is rotationally arranged at the outer side of the motor stator 111, the rigid wheel 131 of the speed reducer 130 is nested at the outer side of the motor 110, the motor stator 111 at the inner side of the motor 110 is directly and fixedly connected with the hollow center shaft 120, and the hollow center shaft 120 is fixedly arranged with the rigid wheel 131; the wave generator 133 of the speed reducer 130 is fixedly connected to the motor rotor 112, and outputs the movement of the motor rotor 112. By adopting the outer rotor motor 110 and adopting the mode of nesting the speed reducer 130 and the motor 110, the hollow aperture inside the hollow center shaft 120 can be relatively enlarged, the heat dissipation area is increased, and the heat dissipation of the motor 110 and the speed reducer 130 is facilitated. In addition, the hollow center shaft 120 and the motor stator 111 are kept relatively static, so that feedback accuracy is facilitated to be provided, cables can be directly arranged in the hollow center shaft 120 conveniently, the output and the fixed end of the cables are relatively static, abrasion of the cables can be reduced, and the service life is prolonged. Because the application of the large hollow aperture hollow center shaft 120 is adopted, a fan and an air duct can be arranged, and the heat dissipation efficiency is further improved.

It should be noted that, the rigid gear 131 of the speed reducer 130 is used for being connected with one mechanical arm, and the flexible gear 132 of the speed reducer 130 is used for being connected with the other mechanical arm, so as to realize the relative movement between the two mechanical arms. The hollow center shaft 120 is not completely static, but rather is relatively static with the rigid wheel 131 and the motor stator 111 and rotates with the motor rotor 112, but the cables fixed in the hollow center shaft 120 remain relatively static with the hollow center shaft 120, so that the wear of the cables can be reduced.

In addition, because the motor 110 and the speed reducer 130 are nested, compared with the prior art that the speed reducer 130 and the motor 110 are connected in series along the axial direction, the axial dimension of the robot joint 100 can be optimized, the cantilever distance of coding feedback is reduced, meanwhile, the cantilever dimensions of the fixed end and the output end (namely, the connecting ends of the robot joint 100 and two mechanical arms respectively) are reduced, the working stress offset of the bearing is reduced, and the positioning precision and the running stability of the whole robot joint 100 are improved.

The manner in which the speed reducer 130 and the motor 110 are nested will be further described below:

in some embodiments, as shown in fig. 1 and 3, the hollow center shaft 120 includes a center shaft end and a connecting section 122, the center shaft section 121 is coaxially embedded in the motor stator 111, the connecting section 122 is connected to an end of the center shaft section 121 and extends outwards along a radial direction of the center shaft section 121, and the connecting section 122 is used for connecting with a rigid wheel 131 of the speed reducer 130. By arranging the middle shaft section 121 and the motor stator 111 to be nested and fixed and arranging the connecting section 122 and the rigid wheel 131 of the speed reducer 130 to be fixed, the hollow middle shaft 120 can relatively fix the motor stator 111 positioned inside the motor 110 and the rigid wheel 131 nested outside the motor 110. Specifically, the hollow center shaft 120 is fixed to the rigid wheel 131 of the speed reducer 130 by bolts.

In some embodiments, as shown in fig. 1 and 3, the motor rotor 112 includes a rotor shaft 1121 and an output flange 1122, the rotor shaft 1121 being rotatably nested outside the motor stator 111, the output flange 1122 being connected to an end of the rotor shaft 1121 and extending radially inward of the rotor shaft 1121 for connection to the wave generator 133. By providing rotor shaft 1121 as rotor shaft 1121 and output flange 1122, output flange 1122 extends radially along rotor shaft 1121 for connection with wave generator 133.

Further, the wave generator 133 is disposed in the accommodating space between the connecting section 122 and the output flange 1122, and is fixedly connected to the output flange 1122. Because the wave generator 133 of the speed reducer 130 is disposed between the engagement section 122 of the hollow center shaft 120 and the output flange 1122 of the motor rotor 112, the overall radial dimensions of the speed reducer 130 and the motor 110 are relatively small, and under a certain condition of the radial dimensions of the whole robot joint 100, the hollow aperture of the hollow center shaft 120 can be relatively enlarged, so that the heat dissipation area is further increased, and the heat dissipation efficiency is improved.

Since the wave generator 133 is disposed near the hollow center shaft 120 and the wave generator 133 rotates relative to the hollow center shaft 120, a first bearing 140 is disposed between the wave generator 133 and the hollow center shaft 120 to carry the relative rotation between the wave generator 133 and the hollow center shaft 120. Preferably, the first bearing 140 is disposed on the bottom bracket segment 121 of the hollow bottom bracket 120 and the wave generator 133. Specifically, the inner ring of the first bearing 140 is fixed to the hollow center shaft 120, and the outer ring of the first bearing 140 is fixed to the wave generator 133.

In some embodiments, as shown in fig. 1 and 3, the flexspline 132 includes an external tooth segment 1321 and a driving segment 1322, the external tooth segment 1321 being disposed between the wave generator 133 and the rigid gear 131, the external tooth segment 1321 being for meshing with the rigid gear 131 having mating internal teeth. The driving section 1322 is connected to an end of the external tooth section 1321 and extends radially outward of the external tooth section 1321 to output the driving of the external tooth section 1321 outward.

Further, as shown in fig. 1 and 3, the robot joint 100 further includes a fixing frame 150 and a cross roller bearing 134, wherein the fixing frame 150 is nested outside the rigid gear 131 and is fixedly connected with the transmission segment 1322 of the flexible gear 132, and the flexible gear 132 is fixed by the fixing frame 150 to output the transmission of the speed reducer 130. Since the mount 150 rotates relative to the rigid wheel 131, the cross roller bearing 134 is disposed between the mount 150 and the rigid wheel 131 to carry the relative rotation between the mount 150 and the rigid wheel 131. Specifically, the outer race of the cross roller bearing 134 is fixed to the mount 150, and the inner race of the cross roller bearing 134 is fixed to the rigid wheel 131. The crossed roller bearing 134 is a main stress bearing, and because the motor 110 and the speed reducer 130 are nested, the axial dimension of the robot joint 100 is relatively shortened, the cantilever distance of coding feedback can be reduced, the working stress bias of the crossed roller bearing 134 is reduced, and the positioning precision and the running stability of the whole robot joint 100 are improved.

Further, as shown in fig. 1 and 3, the robot joint 100 further includes an electromagnetic band-type brake 160 and a second bearing 170, where the electromagnetic band-type brake 160 is relatively fixed to the transmission segment 1322 of the flexspline 132 and is sleeved on the outer side of the motor rotor 112, and the electromagnetic band-type brake 160 is used for realizing braking of the motor rotor 112. The second bearing 170 is disposed between the electromagnetic band-type brake 160 and the motor rotor 112 to carry relative rotation between the electromagnetic band-type brake 160 and the motor rotor 112. Because the axial dimension of the robot joint 100 is relatively shortened, the friction arm braked by the electromagnetic band-type brake 160 is relatively increased, the friction requirement can be effectively reduced, and the dimension of the magnetic coil is further reduced. Specifically, the electromagnetic band-type brake 160 and the fixing frame 150 are respectively disposed at two sides of the transmission segment 1322 of the flexible gear 132, and are fixed by the same bolt.

As is known from the above structure, the motor 110 and the speed reducer 130 are nested, the arrangement of each element is reasonable, the energy density of the robot element is high, the dead weight load ratio of the whole robot joint 100 is effectively improved, the eccentricity of the whole robot joint 100 after assembly is reduced, the rigidity of the whole robot joint 100 is further optimized, the accuracy and the load carrying capacity of the operation process are improved, and the index of the whole robot joint 100 is optimized.

In some embodiments, as shown in fig. 1, 3 and 4, the robotic joint 100 includes a first encoder 181 and a second encoder 182, the first encoder 181 is coaxially fixed with the motor rotor 112, the second encoder 182 is coaxially fixed with the flex 132, and the second encoder 182 is located outside the first encoder 181. Thus, the first encoder 181 is a high-speed shaft encoder, and the second encoder 182 is a low-speed shaft encoder to detect the rotation of the motor rotor 112 and the flexspline 132, respectively.

Further, as shown in fig. 1, 3 and 4, the arrangement direction of the first encoder 181 and the second encoder 182 is perpendicular to the axial direction of the motor 110, that is, the first encoder 181 and the second encoder 182 are arranged in a coplanar manner, and by arranging the first encoder 181 and the second encoder 182 in a coplanar manner, the feedback precision of the two encoders can be optimized, the coaxiality of the feedback mode is further ensured, the installation precision of the robot joint 100 and the operation precision of the whole machine are greatly optimized, the thermal expansion difference of the installation structure of different materials with subsequent temperature rise is eliminated, and the use stability of the codes is improved. In particular, since the first encoder 181 and the second encoder 182 are disposed coplanar, the reading heads of the first encoder 181 and the second encoder 182 may be integrated on the same PCB board.

Yet another embodiment of the present application provides a robot (not shown in the figures) comprising the robot joint 100 of any of the embodiments described above. Specifically, the robot further comprises a first mechanical arm and a second mechanical arm. The robot joint 100 includes a motor 110, a hollow center shaft 120, and a speed reducer 130. The motor 110 includes a motor stator 111 and a motor rotor 112 rotatably disposed outside the motor stator 111, and a hollow center shaft 120 is fixedly embedded in the motor stator 111. The rigid gear 131 of the speed reducer 130 is nested outside the motor 110 and fixedly arranged on the hollow center shaft 120, and the wave generator 133 of the speed reducer 130 is fixedly arranged on the motor rotor 112 so as to be driven to the flexible gear 132 of the speed reducer 130. The first mechanical arm and the rigid wheel 131 are relatively fixed, and the second mechanical arm and the flexible wheel 132 are relatively fixed. The first mechanical arm is relatively fixed with the motor stator 111 through the rigid wheel 131, the motor rotor 112 and the motor stator 111 relatively rotate, the motor rotor 112 transmits rotation to the wave generator 133, the wave generator 133 drives the flexible wheel 132 meshed with the rigid wheel 131 to deform, and motion and power are transmitted to the second mechanical arm through the flexible wheel 132.

The terms "first," "second," "third," and the like in this application are used for descriptive purposes only and are not to be construed as indicating the number of features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature. All directional indications (such as up, down, left, right, front, back … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement, etc. between the components in a particular gesture (as shown in the drawings), and if the particular gesture changes, the directional indication changes accordingly. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. A process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed but may alternatively include other steps or elements not listed or inherent to such process, method, article, or apparatus.

The foregoing description is only exemplary embodiments of the present application and is not intended to limit the scope of the present application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application, or direct or indirect application in other related technical fields are included in the scope of the present application.

Claims

1. A robotic joint, comprising:

the motor comprises a motor stator and a motor rotor rotationally arranged on the outer side of the motor stator;

the hollow center shaft is fixedly embedded in the motor stator;

the rigid gear nest of the speed reducer is arranged outside the motor and fixedly arranged on the hollow center shaft, and the wave generator of the speed reducer is fixedly arranged on the motor rotor so as to drive the flexible gear of the speed reducer.

2. The joint of claim 1 wherein the hollow central shaft comprises:

the middle shaft section is nested and fixed in the motor stator;

and the connecting section is connected with the end part of the middle shaft section and extends outwards along the radial direction of the middle shaft section, and the connecting section is connected with the rigid wheel.

3. The joint of claim 2, wherein the motor rotor comprises:

the rotor shaft is rotationally nested outside the motor stator;

and the output flange is connected with the end part of the rotor shaft and extends inwards along the radial direction of the rotor shaft, and is used for being connected with the wave generator.

4. A joint according to claim 3, wherein the wave generator is disposed between the engagement section and the output flange.

5. The joint according to claim 1, characterized in that it comprises:

the first bearing is arranged between the wave generator and the hollow center shaft.

6. The joint of claim 1, wherein the flexspline comprises:

the external tooth section is arranged between the wave generator and the rigid wheel;

and the transmission section is connected with the end part of the external tooth section and extends outwards along the radial direction of the external tooth section.

7. The joint as claimed in claim 6, comprising:

the fixed mount is nested and arranged on the outer side of the rigid wheel and is fixedly connected with the transmission section;

and the crossed roller bearing is arranged between the fixing frame and the rigid wheel.

8. The joint as claimed in claim 6, comprising:

the electromagnetic band-type brake is fixed relative to the transmission section and sleeved on the outer side of the motor rotor;

the second bearing is arranged between the electromagnetic band-type brake and the motor rotor.

9. The joint according to claim 1, characterized in that it comprises:

the first encoder is coaxially fixed with the motor rotor;

the second encoder is positioned at the outer side of the first encoder and is coaxially fixed with the flexible gear.

10. The joint according to claim 9, wherein the first encoder and the second encoder are arranged in a direction perpendicular to an axial direction of the motor.

11. A robot comprising a robot joint according to any one of claims 1-10.