Direct-drive SCARA robot with rear-located center of gravity.

Abstract

The present invention discloses a horizontal articulated robot comprising a base, a first arm and a second arm connected in sequence, a first motor installed at a connection between the first arm and the base, and a second motor connected to the second arm via a transmission device, the projections of the axes of the first motor and the second motor on a vertical plane at least partially overlap each other. By directly driving the first arm and the second arm with the first motor and the second motor, respectively, a reducer can be omitted, thereby avoiding the accuracy, speed, cost and drag torque of the horizontal articulated robot being affected by the limitations of the reducer. In addition, by installing the first motor and the second motor so as to overlap each other at least partially, the distance between the axes of the two motors can be reduced, thereby reducing the output torque demand of the first motor, and further reducing the overall volume and mass of the horizontal articulated robot, which contributes to realizing high acceleration and high speed of the horizontal articulated robot.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims priority to a Chinese patent application filed on December 31, 2020, bearing application number 2020116329334 and entitled "Direct-Drive SCARA Robot with Rear-Mounted Center of Gravity," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of robots, and in particular to a horizontal articulated robot. [Background technology]

[0003] A horizontal articulated robot, also known as a SCARA (Selective Compliance Assembly Robot Arm), is a robot arm that is applied to assembly work. In general, a horizontal articulated robot is provided with three rotatable joints: a first joint located at the connection point between the base and the first arm, a second joint located at the connection point between the first arm and the second arm, and a third joint located at one end of the second arm away from the first arm. The axes of the three joints are parallel to each other, and the robot can be positioned and oriented within a plane, and its operation is simple, efficient, and low cost.

[0004] Through long-term research and development, the inventors of the present application have found that, currently, in horizontal articulated robots, it is common to install an electric motor at each joint to drive it, but since the distance between the axis of the motor installed at the second joint and the axis of the motor installed at the first joint is generally far, the inertial mass of the moving body to be driven by the motor at the first joint is large, making it difficult to achieve high acceleration and high speed. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a horizontal articulated robot to solve the technical problem that it is difficult to improve the speed and accuracy of horizontal articulated robots due to the limitations of the drive method and structure in the prior art. [Means for solving the problem]

[0006] In order to solve the above technical problems, one technical means adopted in the present invention is: With the base, a first arm connected to the base and having a first joint formed at a connection point with the base; a first electric motor installed in the first joint and used to drive the first arm to rotate relative to the base; a second arm connected to one end of the first arm remote from the base and having a second joint formed at a connection point with the first arm; a second electric motor connected to the second arm via a transmission device and used to drive the second arm to rotate relative to the first arm; The object of the present invention is to provide a horizontal articulated robot, characterized in that the projections of the axis of the first motor and the axis of the second motor on a vertical plane at least partially overlap each other.

[0007] In a specific embodiment, the first motor and the second motor are installed such that their axes overlap.

[0008] In a specific embodiment, the first motor includes a first stator installed on the base and a first rotor connected to the first arm and fitted outside the first stator, and the second motor includes a second stator installed on the first arm and fixedly connected to the first stator, and a second rotor connected to the transmission device and fitted outside the second stator.

[0009] In a specific embodiment, the first motor comprises a first stator installed on the base and a first rotor connected to the first arm and fitted outside the first stator, and the second motor comprises a second stator installed on the first arm and fixedly connected to the first rotor, and a second rotor connected to the transmission device and fitted outside the second stator.

[0010] In a specific embodiment, the transmission device includes a first transmission wheel, a second transmission wheel, a first rigid transmission belt and a second rigid transmission belt, the first transmission wheel is fitted outside the second rotor, the second transmission wheel is connected to the second arm, and the first rigid transmission belt and the second rigid transmission belt are respectively connected to the first transmission wheel and the second transmission wheel by fixed members.

[0011] In a specific embodiment, the transmission device includes at least a first gear fitted outside the second rotor and a second gear connected to the second arm, and is provided with a backlash-free gear assembly in which the first gear and the second gear mesh with each other.

[0012] In a specific embodiment, the transmission device includes a first synchronous wheel fitted outside the second rotor, a second synchronous wheel connected to the second arm, and a synchronous belt connecting the first synchronous wheel and the second synchronous wheel.

[0013] In a specific embodiment, the first motor further has a hollow shaft to form a first accommodating chamber, the second stator forms a second accommodating chamber communicating with the first accommodating chamber, an opening is formed at one end of the second motor away from the first motor, and the second accommodating chamber communicates with the outside through the opening.

[0014] In a specific embodiment, the horizontal articulated robot further includes a controller connected to the base, connected to the first electric motor via a first connecting line passing through the first storage chamber, and connected to the second electric motor via a second connecting line passing through the first storage chamber and the second storage chamber.

[0015] In a specific embodiment, the horizontal articulated robot further includes a first encoder connected to the first electric motor and connected to the controller via a third connecting line passing through the first storage chamber, and a second encoder connected to the second electric motor and connected to the controller via a fourth connecting line passing through the first storage chamber and the second storage chamber.

[0016] In a specific embodiment, the horizontal articulated robot further includes a third motor and a fourth motor installed in the second joint.

[0017] In a specific embodiment, a wire passing hole is provided in the second joint, a wire passage is provided inside the first arm, and the third motor and the fourth motor are connected to the controller via a fifth connecting line passing through the wire passing hole, the wire passage and the first accommodating chamber.

[0018] In a specific embodiment, the second motor is fixedly connected to the base. Effect of the Invention

[0019] The horizontal articulated robot of the present invention includes a base, a first arm connected to the base and having a first joint formed at a connection point with the base, a first electric motor installed within the first joint and used to drive the first arm to rotate relative to the base, a second arm connected to one end of the first arm remote from the base and having a second joint formed at a connection point with the first arm, and a second electric motor connected to the second arm via a transmission device and used to drive the second arm to rotate relative to the first arm, wherein projections of the axis of the first electric motor and the second electric motor at least partially overlap on a vertical plane, and the first electric motor By installing a first motor and a second motor to directly drive the first arm and the second arm, respectively, it is possible to eliminate the need for a reducer, thereby avoiding the accuracy, speed, cost and drag torque of the horizontal articulated robot being affected by the limitations of the reducer. Also, by installing the second motor so that the projection of its axis on a vertical plane relative to the first motor at least partially overlaps, the distance between the axis of the first motor and the axis of the second motor is reduced, thereby reducing the output torque demand of the first motor and further reducing the overall volume and mass of the horizontal articulated robot, contributing to the realization of high acceleration and high speed of the horizontal articulated robot.

[0020] In order to more clearly describe the technical means in the embodiments of the present application, the drawings necessary for describing the embodiments are briefly described below. Of course, the drawings described below are merely some embodiments of the present application, and those skilled in the art can think of other drawings based on these drawings without any creative effort. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of a three-dimensional structure of one embodiment of a horizontal articulated robot of the present invention; [Diagram 2] 1 is a schematic diagram of a partial three-dimensional structure of one embodiment of a horizontal articulated robot of the present invention. FIG. [Diagram 3] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a horizontal articulated robot of the present invention; [Figure 4]1 is a schematic diagram of the three-dimensional structure of a transmission device in one embodiment of a horizontal articulated robot of the present invention. FIG. [Diagram 5] FIG. 13 is a schematic diagram of a cross-sectional structure of another embodiment of a horizontal articulated robot of the present invention. [Figure 6] FIG. 13 is a schematic diagram of a cross-sectional structure of another embodiment of a horizontal articulated robot of the present invention. [Figure 7] FIG. 13 is a schematic diagram of a cross-sectional structure of another embodiment of a horizontal articulated robot of the present invention. [Figure 8] FIG. 13 is a schematic diagram of a cross-sectional structure of another embodiment of a horizontal articulated robot of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In the following, the technical means in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are not all the embodiments, but only some of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

[0023] The terms "first", "second" and the like in this application are for illustrative purposes only and should not be understood as indicating or implying a relative importance or a quantity of the indicated technical features. In the description of this application, unless otherwise expressly and specifically limited, "plurality" means at least two, e.g., two, three, etc. In addition, terms such as "comprises" and "has" and any variations thereof are intended to be non-exclusive. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the steps or units listed, but may further include steps or units that are not listed, or may further include other steps or units that are inherent to the process, method, product or device. The term "and / or" is merely intended to describe the relationship between related objects, and means that three types of relationships can exist, for example, A and / or B may mean that A exists alone, A and B exist simultaneously, or B exists alone. In addition, the symbol " / " in this specification generally means that the related objects before and after are in an "or" relationship.

[0024] 1 to 3, one embodiment of the horizontal articulated robot 10 of the present invention includes a base 100, a first arm 200 connected to the base 100 and having a first joint 210 formed at a connection point with the base 100, a second arm 300 connected to one end of the first arm 200 remote from the base 100 and having a second joint 310 formed at a connection point with the first arm 200, a first electric motor 410 installed within the first joint 210 and used to drive the first arm 200 to rotate relative to the base 100, and a second electric motor 420 connected to the second arm 300 via a transmission device 500 and used to drive the second arm 300 to rotate relative to the first arm 200, and the projections of the axis of the first electric motor 410 on a vertical plane of the first electric motor 410 and the second electric motor 420 at least partially overlap each other.

[0025] At present, horizontal articulated robots are generally driven by installing electric motors at each joint, for example, by combining a servo motor and a reducer, but this driving method has the following problems. 1) There is a back gap, making it difficult to improve the accuracy of the horizontal articulated robot. 2) The maximum output torque of the reducer is limited, making it difficult to improve the speed of the horizontal articulated robot. 3) The cost of the reducer is high. 4) Due to the transmission method combining the electric motor and the reducer, the torque for manually dragging the horizontal articulated robot is large, which affects the manual drag teaching function of the horizontal articulated robot. However, in this embodiment, the first electric motor 410 and the second electric motor 420 are installed to directly drive the first arm 200 and the second arm 300, respectively, so that the reducer can be omitted and the accuracy, speed, cost and drag torque of the horizontal articulated robot 10 are avoided from being affected by the limitations of the reducer.

[0026] In the current horizontal articulated robot driven by a direct drive motor, the output torque must be the same as that generated by a drive method with a reducer, and the direct drive motor is larger in volume and mass than the original servo motor, which leads to an increase in the volume and mass of the entire horizontal articulated robot, and the distance between the axis of the motor installed at the second joint and the axis of the motor installed at the first joint is far, and the inertial mass of the moving body to be driven by the motor at the first joint is large, making it difficult to achieve high acceleration and high speed. However, in this embodiment, the second motor 420 is installed so that the projection of the axis on the vertical plane at least partially overlaps with the first motor 410, thereby reducing the distance between the axis of the first motor 410 and the axis of the second motor 420, thereby reducing the output torque demand of the first motor 410, and further reducing the overall volume and mass of the horizontal articulated robot 10, which contributes to the realization of high acceleration and high speed of the horizontal articulated robot 10.

[0027] In this embodiment, the first electric motor 410 and the second electric motor 420 are installed so that their axes overlap, so that the output torque of the first electric motor 410 required for the first arm 200 on which the second electric motor 420 is mounted is smaller, which can further reduce the overall volume and mass of the horizontal articulated robot 10 and contribute to realizing high acceleration and high speed of the horizontal articulated robot 10.

[0028] In this embodiment, the first electric motor 410 includes a first stator 411 installed on the base 100 and a first rotor 412 connected to the first arm 200 and fitted outside the first stator 411. The second electric motor 420 includes a second stator 421 installed on the first arm 200 and fixedly connected to the first stator 411, and a second rotor 422 connected to the transmission device 500 and fitted outside the second stator 421. Thus, when the first electric motor 410 is started, the first arm 200 can be rotated relative to the base 100 in conjunction with the rotation of the first rotor 412 relative to the first stator 411. At this time, since the second stator 421 is fixedly connected to the first stator 411, The second stator 421 does not move, and since the second motor 420 is not started, the second rotor 422 does not move either, and therefore the second arm 300 is not driven. Since the first arm 200 also rotates relative to the base 100 when it rotates relative to the second arm 300, when it is necessary to maintain the relative position between the second arm 300 and the first arm 200 unchanged, the second motor 420 must be started, thereby rotating the second rotor 422 relative to the second stator 421 in the same direction and angle as the rotation of the first rotor 412, and then the second arm 300 is linked by the transmission device 500 to rotate in the same direction and angle as the rotation of the first arm 200, thereby achieving compensation.

[0029] In this embodiment, in order to stabilize the overall structure of the horizontal articulated robot 10, the first stator 411 and the second stator 421 may be connected by a flange 430.

[0030] In other embodiments, the first stator 411 and the second stator 421 may be connected in other ways, such as by pasting or fastening, and are not limited thereto.

[0031] In this embodiment, the first rotor 412 is fixedly connected directly to the first arm 200 so as to rotate the first arm 200 in unison.

[0032] In other embodiments, the first rotor 412 may be connected to the first arm 200 via a transmission (not shown), which is not limited here.

[0033] 4, in this embodiment, the transmission device 500 includes a first transmission wheel 510, a second transmission wheel 520, a first rigid transmission belt 530 and a second rigid transmission belt 540, the first transmission wheel 510 is fitted on the outside of the second rotor 422, the second transmission wheel 520 is connected to the second arm 300, the first rigid transmission belt 530 and the second rigid transmission belt 540 are respectively connected to the first transmission wheel 510 and the second transmission wheel 520 by a fixing member 550, and the first rigid transmission belt 530 and the second rigid transmission belt 540 are respectively connected to the first transmission wheel 510 and the second transmission wheel 520 by a fixing member 550. By installing the transmission wheel 540 to transmit power between the first transmission wheel 510 and the second transmission wheel 520, power transmission between the second electric motor 420 and the second arm 300 can be realized, thereby reducing the restriction on the installation position of the second electric motor 420 on the second arm 300, contributing to reducing the distance between the axis of the first electric motor 410 and the axis of the second electric motor 420, avoiding the backlash problem during the transmission process, and improving the driving accuracy of the second electric motor 420, which further contributes to improving the overall accuracy of the horizontal articulated robot 10.

[0034] In this embodiment, the first rigid power transmission belt 530 and the second rigid power transmission belt 540 may be steel belts, but in other embodiments, the first rigid power transmission belt 530 and the second rigid power transmission belt 540 may be other metal belts, rigid plastic belts, etc., and are not limited thereto.

[0035] In this embodiment, a bearing 521 may be installed between the second transmission wheel 520 and the second arm 300 so as to reduce friction between the second transmission wheel 520 and the second arm 300 and improve the service life of the transmission device 500.

[0036] In another specific embodiment, the transmission device 500 may include a first synchronous wheel (not shown) fitted outside the second rotor 422, a second synchronous wheel (not shown) connected to the second arm 300, and a synchronous belt (not shown) connecting the first synchronous wheel and the second synchronous wheel. When the second rotor 422 rotates, the first synchronous wheel rotates accordingly, transmitting and moving the synchronous belt, and further interlocking the second synchronous wheel to rotate the second arm 300 in conjunction. The first synchronous wheel, the second synchronous wheel, and the synchronous belt can realize the transmission between the second electric motor 420 and the second arm 300, thereby reducing the installation position restriction of the second electric motor 420 on the second arm 300 and contributing to the realization of a reduction in the distance between the axis of the first electric motor 410 and the axis of the second electric motor 420.

[0037] In this embodiment, the first electric motor 410 further includes a hollow shaft 413 to form a first accommodating chamber 414, the second stator 421 defines a second accommodating chamber 423 communicating with the first accommodating chamber 414, and an opening 424 is formed at one end of the second electric motor 420 remote from the first electric motor 410, and the second accommodating chamber 423 communicates with the outside through the opening 424. As a result, the heat generated inside the first electric motor 410 and the second electric motor 420 can be transferred to the outside through the first accommodating chamber 414 and the second accommodating chamber 423, thereby realizing effective heat dissipation, which contributes to improving the service life of the first electric motor 410 and the second electric motor 420 and contributing to realizing high-speed operation of the first electric motor 410 and the second electric motor 420.

[0038] In this embodiment, an end cover 440 is provided to cover the second rotor 422, and an opening 424 can be formed in the end cover 440 to realize communication between the second accommodating chamber 423 and the outside. Furthermore, by providing the end cover 440, it is possible to provide a waterproof and dustproof function, and the service life of the second electric motor 420 can be improved.

[0039] In this embodiment, the horizontal articulated robot 10 may further include a controller 600 connected to the base 100, connected to the first electric motor 410 via a first connection line 610 passing through the first storage chamber 414, and connected to the second electric motor 420 via a second connection line 620 passing through the first storage chamber 414 and the second storage chamber 423. Compared with the solid hollow shaft motors currently used in horizontal articulated robots, in which the connecting wires are wrapped around the outside of the motors, complicating the internal structure of the horizontal articulated robot and the connecting wires are prone to interfering with other components, in this embodiment, the first connecting wire 610 and the second connecting wire 620 between the first electric motor 410, the second electric motor 420 and the controller 600 directly pass through the first electric motor 410 and the second electric motor 420, making the internal structure of the horizontal articulated robot 10 simpler and the first connecting wire 610 and the second connecting wire 620 less likely to interfere with other components, and enabling the horizontal articulated robot 10 to have higher reliability.

[0040] In this embodiment, the horizontal articulated robot 10 further includes a first encoder 450 connected to the first electric motor 410 and connected to the controller 600 via a third connection line 630 passing through the first accommodation chamber 414, and a second encoder 460 connected to the second electric motor 420 and connected to the controller 600 via a fourth connection line 640 passing through the first accommodation chamber 414 and the second accommodation chamber 423. The first encoder 450 is installed to be combined with the direct drive method of the first electric motor 410, and the second encoder 460 is installed to be combined with the direct drive method of the second electric motor 420, thereby This improves the driving accuracy of the two electric motors 420, and further improves the overall operating accuracy of the horizontal articulated robot 10. Furthermore, by connecting the first encoder 450 and the second encoder 460 to the controller 600 by connecting wires that pass through the first storage chamber 414 and the second storage chamber 423, it is possible to prevent the connecting wires from wrapping around the outside of the motors and complicating the internal structure of the horizontal articulated robot 10, making the internal structure of the horizontal articulated robot 10 simpler, and making the third connecting wire 630 and the fourth connecting wire 640 less likely to interfere with other components, thereby making it possible to increase the reliability of the horizontal articulated robot 10.

[0041] In this embodiment, the first encoder 450 and the second encoder 460 may both be annular encoders, with the first encoder 450 fitted outside the hollow shaft 413 and the second encoder 460 installed on the second stator 421, which can avoid blocking the heat dissipation airflow flowing between the first accommodating chamber 414 and the second accommodating chamber 423, and the heat dissipation airflow can achieve a heat dissipation effect on the first encoder 450 and the second encoder 460, and further improve the reliability and stability of the operation of the first encoder 450 and the second encoder 460.

[0042] In another embodiment, the first encoder 450 and the second encoder 460 may be solid encoders, with at least a portion of the first encoder 450 being installed in the first accommodating chamber 414 and at least a portion of the second encoder 460 being installed in the second accommodating chamber 423, so that the first encoder 450 and the second encoder 460 can dissipate heat when the heat dissipation airflow flows through the first accommodating chamber 414 and the second accommodating chamber 423, and the reliability and stability of the operation of the first encoder 450 and the second encoder 460 can be further improved.

[0043] In this embodiment, the first electric motor 410 further includes a first bearing 415 that is installed between the hollow shaft 413 and the first rotor 412 to reduce friction between the hollow shaft 413 and the first rotor 412, thereby improving the service life of the first electric motor 410 and avoiding the interruption of communication between the first accommodating chamber 414 and the second accommodating chamber 423.

[0044] In this embodiment, the first motor 410 may further include a second bearing 416 that is installed between the first base 417 and the first rotor 412 of the first motor 410 to reduce friction between the first base 417 and the first rotor 412 and improve the service life of the first motor 410, and also firmly connects the first base 417 to the heavy first stator 411 to overcome the overturning moment thereof and further stabilize the structure of the first motor 410.

[0045] In this embodiment, the base 100 may further be formed with a through hole (not shown) communicating with the first accommodation chamber 414, so that the heat dissipation gas in the first accommodation chamber 414 can further flow to the outside through the through hole of the base 100, further improving the heat dissipation effect. In addition, by installing the second bearing 416 between the first base part 417 and the first rotor 412, it is possible to avoid blocking the release of the heat dissipation airflow from the base 100.

[0046] In this embodiment, the second motor 420 may further include a third bearing 425 that is installed between the second stator 421 and the second rotor 422 to reduce friction between the second stator 421 and the second rotor 422, thereby improving the service life of the second motor 420, and also to avoid blocking communication between the second accommodating chamber 423 and the outside.

[0047] In this embodiment, the second motor 420 may further include a fourth bearing 426, which is installed between the second base 427 and the second rotor 422 of the second motor 420, to reduce the friction between the second base 427 and the second rotor 422 to improve the service life of the second motor 420, and also to firmly connect the second base 427 to the heavy second stator 421 to overcome the overturning moment thereof and further stabilize the structure of the second motor 420.

[0048] In this embodiment, the horizontal articulated robot 10 may further include a third electric motor 470, a fourth electric motor 480 and a shaft body 320, where the third electric motor 470 and the fourth electric motor 480 are installed in the second joint 310, the shaft body 320 is installed at one end of the second arm 300 away from the first arm 200, and the third electric motor 470 and the fourth electric motor 480 are respectively connected to the shaft body 320 and are respectively used to drive the rotation and vertical movement of the shaft body 320. Compared with current horizontal articulated robots in which the third and fourth electric motors for driving the shafts are installed at one end of the second arm away from the first arm, in this embodiment, the third electric motor 470 and the fourth electric motor 480 are installed within the second joint 310, thereby reducing the distance between the axis of the third electric motor 470 and the axis of the fourth electric motor 480 and the axis of the first electric motor 410 and the axis of the second electric motor 420, thereby reducing the output torque demand of the first electric motor 410 and the second electric motor 420, thereby reducing the overall volume and mass of the horizontal articulated robot 10, and further contributing to realizing high acceleration and high speed of the horizontal articulated robot 10.

[0049] In this embodiment, a wire passing hole 311 is installed in the second joint 310, a wire passage 220 is installed inside the first arm 200, and the third electric motor 470 and the fourth electric motor 480 are connected to the controller 600 via the fifth connecting line 650 through the wire passing hole 311, the wire passage 220 and the first accommodating chamber 414, thereby preventing the fifth connecting line 650 from wrapping around the outside of the first electric motor 410 and complicating the internal structure of the horizontal articulated robot 10, making the internal structure of the horizontal articulated robot 10 simpler, and making the fifth connecting line 650 less likely to interfere with other components, thereby making it possible to improve the reliability of the horizontal articulated robot 10.

[0050] In this embodiment, the third motor 470 and the fourth motor 480 may be connected to the shaft 320 via a transmission device (not shown), and here, for the structure of the transmission device, please refer to the above-mentioned transmission device 500, and detailed description will be omitted here.

[0051] In another embodiment, the third motor 470 and the fourth motor 480 may be installed on the first arm 200, thereby further reducing the distance between the axis of the third motor 470 and the axis of the fourth motor 480 and the axis of the first motor 410 and the axis of the second motor 420, and reducing the output torque demand of the first motor 410 and the second motor 420, thereby further reducing the overall volume and mass of the horizontal articulated robot 10, and further contributing to realizing high acceleration and high speed of the horizontal articulated robot 10.

[0052] Referring to FIG. 5, another embodiment of the horizontal articulated robot 10 of the present invention comprises a base 100, a first arm 200, a second arm 300, a first electric motor 710 and a second electric motor 720. Here, for the structures of the base 100, the first arm 200 and the second arm 300, please refer to the embodiment of the horizontal articulated robot 10 described above, and detailed description thereof will be omitted here.

[0053] This embodiment differs from the above embodiment in that the first electric motor 710 includes a first stator 711 installed on the base 100 and a first rotor 712 connected to the first arm 200 and fitted around the outside of the first stator 711, and the second electric motor 720 includes a second stator 721 installed on the first arm 200 and fixedly connected to the first rotor 712, and a second rotor 722 connected to the transmission device 500 and fitted around the outside of the second stator 721. As a result, when the first electric motor 710 is started, the first stator 711 of the first rotor 712 is rotated. At this time, since the second stator 721 is fixedly connected to the first rotor 712, it rotates along with the first rotor 712, and since the second motor 720 is not started, the second rotor 722 also rotates along with it. Therefore, the second arm 300 is rotated in the same direction and angle as the rotation of the first arm 200 by the transmission device 500, and the relative position of the second arm 300 to the first arm 200 is maintained unchanged.

[0054] In this embodiment, in order to stabilize the overall structure of the horizontal articulated robot 10, the second stator 721 and the first rotor 712 may be connected by a flange 730.

[0055] In other embodiments, the second stator 721 and the first rotor 712 may be connected in other ways, such as by gluing or fastening, and are not limited thereto.

[0056] Referring to FIG. 6, another embodiment of the horizontal articulated robot 10 of the present invention comprises a base 100, a first arm 200, a second arm 300, a first electric motor 810 and a second electric motor 820. Here, for the structures of the base 100, the first arm 200 and the second arm 300, please refer to the embodiment of the horizontal articulated robot 10 described above, and detailed description thereof will be omitted here.

[0057] This embodiment differs from the above-mentioned embodiment in that the second electric motor 820 is fixedly connected to the base 100. Specifically, the base 100 includes a first mounting plate 110 and a second mounting plate 120 that are installed at an interval along the axial direction of the first electric motor 810. The first electric motor 810 includes a first stator 811 installed on the first mounting plate 110 and a first rotor 812 connected to the first arm 200 and fitted outside the first stator 811, and the second electric motor 820 includes a second stator 821 installed on the second mounting plate 120 and a second rotor 822 connected to the transmission device 500 and fitted outside the second stator 821. In this embodiment, the manner in which the first electric motor 810 and the second electric motor 820 drive the first arm 200 and the second arm 300 is similar to the manner in which the first electric motor 410 and the second electric motor 420 drive the first arm 200 and the second arm 300 in the above embodiment, and detailed explanation is omitted here.

[0058] In this embodiment, by connecting the second electric motor 820 to the base 100, the mass carried by the first electric motor 810 can be further reduced, and the output torque demand of the first electric motor 810 can be further reduced, thereby reducing the overall volume and mass of the horizontal articulated robot 10, and contributing to realizing high acceleration and high speed of the horizontal articulated robot 10.

[0059] In this embodiment, the axes of the first electric motor 810 and the second electric motor 820 overlap, and the projections of the axis of the first electric motor 810 on the vertical plane of the first electric motor 810 and the second electric motor 820 are all overlapped, so that the center of gravity of the horizontal articulated robot 10 can be more stabilized and the entire structure can be made more stable.

[0060] Referring to FIG. 7, in another specific embodiment, the axes of the first motor 810 and the second motor 820 are installed in parallel, and the projections of the axis of the first motor 810 on the vertical plane of the first motor 810 and the second motor 820 partially overlap each other, and the distance between the second motor 820 and the second joint 310 is closer, so that the distance that the transmission device 500 must transmit is shorter and the possibility of error occurrence is smaller.

[0061] 6, in this embodiment, the transmission device 500 transmits power using a rigid transmission belt, and the specific structure thereof can be referred to the embodiment of the horizontal articulated robot 10, and detailed description thereof will be omitted here.

[0062] Referring to FIG. 8, in another specific embodiment, the transmission device 500 comprises a backlash-free gear assembly including at least a first gear 560 and a second gear 570, the first gear 560 and the second gear 570 have the same tooth thickness, the same installation height, and are seamlessly meshed to realize backlash-free transmission. The first gear 560 is fitted on the outside of the second rotor 822, and the second gear 570 is connected to the second arm 300. The first gear 560 and the second gear 570 mesh with each other, and when the second rotor 822 rotates, the first gear 560 rotates accordingly. The first electric motor 820 rotates first, so that the second arm 300 can be rotated in conjunction with the second gear 570. The backlash-free gear assembly can realize the transmission between the second electric motor 820 and the second arm 300, thereby reducing the restriction on the installation position of the second electric motor 820 on the second arm 300, contributing to reducing the distance between the axis of the first electric motor 810 and the axis of the second electric motor 820, avoiding the backlash problem in the transmission process, and improving the driving accuracy of the second electric motor 820, which contributes to improving the overall accuracy of the horizontal articulated robot 10.

[0063] The above is merely an embodiment of the present application and does not limit the scope of the claims of the present application. Any equivalent configuration or equivalent flow conversion made by utilizing the contents of the specification and drawings of the present application, or any direct or indirect application thereof to other related technical fields, is similarly intended to be included in the scope of the claims of the present application.

Claims

1. With the base, a first arm connected to the base and having a first joint formed at a connection point with the base; a first electric motor installed in the first joint and used to drive the first arm to rotate relative to the base; a second arm connected to one end of the first arm remote from the base and having a second joint formed at a connection point with the first arm; a second electric motor connected to the second arm via a transmission device and used to drive the second arm to rotate relative to the first arm; a projection of an axis of the first motor and a projection of the second motor on a vertical plane at least partially overlaps with each other; The base includes a first mounting plate and a second mounting plate, the first motor includes a first stator mounted on the first mounting plate and a first rotor connected to the first arm and fitted around the outside of the first stator; the second motor includes a second stator mounted on the second mounting plate and a second rotor connected to the transmission device and fitted around the outside of the second stator; a first electric motor further including a hollow shaft to form a first accommodation chamber, a second stator forming a second accommodation chamber communicating with the first accommodation chamber, an opening being formed at one end of the second electric motor remote from the first electric motor, and the second accommodation chamber communicating with the outside via the opening.

2. 2. The horizontal articulated robot according to claim 1, wherein the first electric motor and the second electric motor are installed so that their axes overlap each other.

3. 3. The horizontal articulated robot according to claim 1 or 2, characterized in that the transmission device comprises a first transmission wheel, a second transmission wheel, a first rigid transmission belt and a second rigid transmission belt, the first transmission wheel is fitted outside the second rotor, the second transmission wheel is connected to the second arm, and the first rigid transmission belt and the second rigid transmission belt are each connected to the first transmission wheel and the second transmission wheel by a fixing member.

4. 3. The horizontal articulated robot according to claim 1 or 2, characterized in that the transmission device comprises a backlash-free gear assembly including at least a first gear fitted to the outside of the second rotor and a second gear connected to the second arm, the first gear and the second gear meshing with each other.

5. 3. The horizontal articulated robot according to claim 1, wherein the transmission device comprises a first synchronous wheel fitted to the outside of the second rotor, a second synchronous wheel connected to the second arm, and a synchronous belt connecting the first synchronous wheel and the second synchronous wheel.

6. 2. The horizontal articulated robot according to claim 1, further comprising a controller connected to the base, passing through the first storage chamber via a first connection line and connected to the first electric motor, and passing through the first storage chamber and the second storage chamber via a second connection line and connected to the second electric motor.

7. 7. The horizontal articulated robot according to claim 6, further comprising: a first encoder connected to the first electric motor and connected to the controller via a third connection line passing through the first accommodation chamber; and a second encoder connected to the second electric motor and connected to the controller via a fourth connection line passing through the first accommodation chamber and the second accommodation chamber.

8. 2. The horizontal articulated robot according to claim 1, further comprising a third motor and a fourth motor disposed within the second joint.

9. Further comprising a third motor and a fourth motor installed in the second joint, 7. The horizontal articulated robot according to claim 6, wherein a wire passing hole is provided in the second joint, a wire passage is provided inside the first arm, and the third electric motor and the fourth electric motor are connected to the controller via a fifth connecting line passing through the wire passing hole, the wire passage and the first accommodating chamber.

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