A high-rigidity heavy-duty robot with a closed-loop structure

Abstract

This invention relates to a robot, specifically a high-rigidity heavy-duty robot with a closed-loop structure. The aim is to provide a high-rigidity heavy-duty robot with a closed-loop structure, characterized by high rigidity and high precision. The technical solution is a high-rigidity heavy-duty robot with a closed-loop structure, characterized in that: the robot further includes a base fixed to the ground, a rotating base rotatably positioned at the top of the base about a vertical axis, a first drive device installed in the rotating base to drive the rotating base to rotate, a first robotic arm oscillating about a horizontal axis and positioned on the rotating base, a second drive device installed on the rotating base to drive the first robotic arm to oscillate, a second robotic arm connected to the top of the first robotic arm via a hinge shaft, a third drive device installed on the rotating base to drive the second robotic arm to oscillate, and two sets of hydraulic rods installed between the rotating base and the first robotic arm for balancing torque.

Description

Technical Field

[0001] This invention relates to a robot, specifically a high-rigidity heavy-duty robot with a closed-loop structure. Background Technology

[0002] High-rigidity heavy-duty robots have demonstrated significant application value in multiple fields. In manufacturing, such as automobile manufacturing, the assembly of car bodies requires the handling of heavy automotive components, such as engines and chassis. Only robots with heavy-duty capabilities can ensure the precise movement and positioning of these heavy parts. In automotive body welding, high-rigidity robots can reduce vibration and deformation during the welding process, resulting in more precise welding trajectories, thereby improving welding quality and ensuring the structural strength of the car body. In port logistics, where large quantities of containers need to be handled, high-rigidity heavy-duty robots are generally used to improve port efficiency in container loading and unloading operations. Compared to traditional cranes, high-rigidity heavy-duty robots are more flexible and have a higher degree of automation. Their high rigidity ensures that in complex coastal environments, affected by factors such as sea winds, they effectively prevent container swaying, ensuring the safety and accuracy of cargo loading and unloading. In the construction industry, robots are needed to carry heavy inspection equipment for structural testing and maintenance. Heavy-duty capacity ensures that the robot can move this equipment to various parts of the building structure, while high rigidity helps it maintain stability at heights and on complex building surfaces. Robots with high rigidity and heavy-duty performance improve production efficiency and quality while reducing production costs and risks. With continuous technological advancements and innovation, their application prospects in these fields will become even broader.

[0003] Traditional open-loop heavy-duty robots, due to their open-loop structure, are more prone to accumulating end-effector errors under heavy loads, leading to low working accuracy. Because of the structural characteristics of open-loop structures, the final load is borne solely by the end-effector, and torque is transmitted through a single link, resulting in lower overall load-bearing capacity and deformation resistance. Therefore, open-loop robots have relatively low load-bearing capacity and stiffness, necessitating the introduction of robots with closed-loop structures. For heavy-duty robots with closed-loop structures, the advantages compared to traditional open-loop structures are particularly significant. Multiple branches in a closed-loop structure simultaneously bear the load, resulting in better load-bearing capacity and greater deformation resistance; furthermore, due to its structural characteristics, it achieves higher working accuracy. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a high-rigidity heavy-duty robot with a closed-loop structure, which has the characteristics of high rigidity and high precision.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0006] A high-rigidity heavy-duty robot with a closed-loop structure includes an end effector flange or a working arm with three degrees of freedom; characterized in that: the robot further includes a base fixed to the ground, a rotating base rotatably positioned at the top of the base about a vertical axis, a first drive device installed in the rotating base to drive the rotating base to rotate, a first robotic arm oscillating about a horizontal axis and positioned on the rotating base, a second drive device installed on the rotating base to drive the first robotic arm to oscillate, a second robotic arm connected to the top of the first robotic arm via a hinge shaft, a third drive device installed on the rotating base to drive the second robotic arm to oscillate, and two sets of hydraulic rods installed between the rotating base and the first robotic arm for balancing torque; the end effector flange or the working arm is mounted on the second robotic arm.

[0007] The bottom end of the first robotic arm is pivotally positioned on a rotating base via a second revolute joint; the second revolute joint includes a horizontally arranged connecting shaft fixed to the bottom end of the first robotic arm and a bushing mounted on the rotating base and rotatably engaged with the connecting shaft.

[0008] The hydraulic cylinders of the two sets of hydraulic rods are respectively oscillatingly positioned on both sides of the rotating base through the fourth rotating joint, and the movable rod that cooperates with the hydraulic cylinder is connected to the top of the swing arm through the fifth rotating joint; the bottom end of the swing arm is fixed to the connecting shaft.

[0009] The fourth rotating pair includes a hinge sleeve fixed to the hydraulic cylinder and a hinge shaft fixed to the rotating base and rotatably engaged with the hinge sleeve; the hinge shaft is horizontally mounted on the rotating base, and both ends of the hinge shaft extend outwards on the left and right sides of the rotating base, thereby hinged to the hinge sleeve.

[0010] The fifth revolute joint includes a short shaft fixed to the swing arm and a hinged cylinder fixed to one end of the movable rod and rotatably engaged with the short shaft; the rotation axes of the two fifth revolute joints are arranged coaxially.

[0011] The second driving device includes a first sliding joint, a first lead screw joint, and a second motor that drives the first sliding joint, all mounted on a rotating base. The first sliding joint includes a first guide rail that is horizontally mounted on the rotating base and perpendicular to the rotation axis of the second sliding joint, and a first slider that cooperates with the first guide rail. The first lead screw joint includes a first lead screw that is mounted on the rotating base and parallel to the first guide rail, and a first lead screw nut that cooperates with the first guide rail and connects to the first slider. One end of the first driving rod is hinged to the first robotic arm, and the other end is hinged to the first slider. The motor shaft of the second motor is connected to the first lead screw via a coupling.

[0012] The third driving device includes a third motor mounted on a third driving device mounting base and driven by a second lead screw pair and a second sliding pair; the second sliding pair includes a second guide rail horizontally mounted on the third driving device mounting base and perpendicular to the rotation axis of the second rotating pair, and a second slider cooperating with the second guide rail; the second lead screw pair includes a second lead screw mounted on the third driving device mounting base and parallel to the second guide rail, and a second lead screw nut cooperating with the second guide rail and connected to the second slider; one end of the second driving rod is hinged to the second robotic arm, and the other end is hinged to the second slider; the motor shaft of the second motor is connected to the second lead screw through a coupling.

[0013] One end of the second robotic arm is connected to the top of the first robotic arm via a third revolute joint, and the other end is connected to the second drive rod in the third drive device via a ninth revolute joint. The other end of the second drive rod is connected to the second slider via an eighth revolute joint. The third revolute joint, the ninth revolute joint, and the eighth revolute joint all include a horizontally arranged shaft parallel to the rotation axis of the second revolute joint and a bushing that cooperates with the shaft.

[0014] The rotating base is rotatably positioned at the top of the base via a first rotating joint around a vertical axis. The first rotating joint includes a circular guide rail laid on the top of the base and several sliders installed at the bottom of the rotating base that cooperate with the circular guide rail. The first driving device includes two first motors symmetrically mounted on the base plate, two first gears mounted one on each of the two first motor shafts, and a second gear fixed at the bottom of the base and meshing with both first gears.

[0015] The three-degree-of-freedom working arm includes a third robotic arm rotatably positioned on a second robotic arm, a motor and transmission gear set mounted on the second robotic arm for driving the third robotic arm, a fourth motor mounting base rotatably positioned at the top of the third robotic arm, a fourth motor mounted in the fourth motor mounting base, and an end working flange connected to the shaft end of the fourth motor.

[0016] The beneficial effects of this invention are:

[0017] The high-rigidity heavy-duty robot with a closed-loop structure proposed in this invention has the characteristics of high stability, high rigidity, and strong load capacity, and can be applied to multiple fields such as manufacturing, logistics, and construction. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the first driving device in Embodiment 1 of the present invention.

[0020] Figure 3This is a schematic diagram of the second driving device in Embodiment 1 of the present invention.

[0021] Figure 4 This is a schematic diagram of the third driving device in Embodiment 1 of the present invention.

[0022] Figure 5 This is Embodiment 2 of the present invention.

[0023] Figure label:

[0024] 1-Base, 1.1-Base plate, 1.2-First motor mount, 1.3-First motor, 1.4-First gear, 1.5-Second gear, 1.6-Gear connecting seat, A1-First rotating pair;

[0025] 2-Rotating base, 2.1-Fourth rotating pair mounting base, A2-Second rotating pair;

[0026] 3-Second driving device, 3.1-First slider, 3.2-First guide rail, 3.3-First lead screw, 3.4-Second motor base, 3.6-Second motor, 3.7-First drive rod, A3-Third rotating pair;

[0027] 4-First robotic arm, 4.1-Connecting shaft, 4.2-Swing arm, 4.3-Seventh revolute joint mounting base, A4-Fourth revolute joint;

[0028] 5-Third drive unit mounting base, A5-Fifth rotating pair;

[0029] 6-Third drive device, 6.1-Second slider, 6.2-Second guide rail, 6.3-Second lead screw, 6.4-Second coupling, 6.5-Third motor, 6.6-Third motor base, 6.7-Second drive rod, A6-Sixth rotary joint;

[0030] 7-Second robotic arm, 8-Third robotic arm, 9-Fourth motor mounting base, 10-First motor, 11-End working flange, 12-Hydraulic rod;

[0031] A7 - Seventh revolute joint, A8 - Eighth revolute joint, A9 - Ninth revolute joint, A10 - Tenth revolute joint, A11 - Eleventh revolute joint. Detailed Implementation

[0032] The present invention will be further described below with reference to the examples shown in the accompanying drawings.

[0033] Example 1

[0034] Figure 1In the high-rigidity heavy-duty robot with a closed-loop structure shown, the base 1 is fixed to the ground, and the rotating base 2 is rotatably mounted on the top of the base through the first rotating joint A1 around the vertical axis. The base bears the weight of the rotating base and the mechanisms it carries through the first rotating joint. The first driving device is installed in the base to drive the rotating base to rotate.

[0035] The second drive unit 3 is horizontally mounted on the rotating base. The first robotic arm 4 is mounted on the rotating base via the second rotating joint A2. The second drive unit drives the first prismatic joint to rotate the first robotic arm 4 around the axis of the second rotating joint A2. In order to prevent the robot from having a precision deviation due to excessive load on the working end, two sets of hydraulic rods 12 are installed on both sides of the rotating base and the first robotic arm to balance the torque.

[0036] A third drive device 6 is installed on the third drive device mounting base 5 above the second drive device, and is positioned slightly above and behind the second drive device. The two ends of the second robotic arm 7 are respectively connected to the first robotic arm through the third rotary joint A3 and the third drive device through the ninth rotary joint A9. The third drive device drives the second prismatic joint to move, causing the second robotic arm to rotate around the third rotary joint.

[0037] Figure 2 The specific structure of the first driving device is as follows: The top of the base 1 is circular, and a circular guide rail is laid on the top of the base. The rotating base is rotatably positioned on the top of the base 1 via several sliders fixed to its bottom end and coaxially arranged with the base. Clearly, the circular guide rail and the sliders form the first rotating pair. A gear connecting seat 1-6 is fixed to the middle of the bottom end of the rotating base, and a second gear 1.5 is fixed to the bottom end of the gear connecting seat and coaxially arranged with the base. Inside the base, two first motor mounting seats 1.2 are symmetrically mounted on the base plate 1.1, and two first motors 1.3 are respectively mounted in two motor seats. The motor shafts at the top of the two motors are vertically arranged and each has a first gear 1.4 fixed to it. Both first gears mesh with the second gear simultaneously. During operation, the two motors drive the two first gears respectively, which in turn drive the gear connecting seat and the rotating base to rotate together through the transmission of the second gear.

[0038] Figure 3This is a schematic diagram of the drive mechanism between the second drive device and the first robotic arm; wherein: in the second drive device 3: the first slider 3.1 and the first guide rail 3.2 cooperate to form a first sliding pair, and the first guide rail is horizontally mounted on the rotating base; the first lead screw 3.3 is rotatably mounted on the first guide rail seat through brackets at both ends and is arranged parallel to the first guide rail; the length direction of the first guide rail is perpendicular to the second rotating pair; the second motor seat 3.4 is mounted at the end of the first guide rail (the end away from the first robotic arm), the second motor 3.6 is mounted in the second motor seat, and the shaft of the second motor is connected to the first lead screw through a coupling; a first lead screw nut that meshes with the first lead screw is also fixed on the first slider that slides on the first guide rail.

[0039] One end of the first robotic arm is hinged to a bushing on the rotating base via a horizontally arranged connecting shaft 4.1, which is also fixed to the bottom end of the first robotic arm. This connecting shaft extends outwards from both ends, with swing arms 4.2 mounted at each end. The other ends of the two swing arms are connected via fifth revolute joints A5 to one end of the movable rod in two sets of hydraulic rods (the hydraulic rods include hydraulic cylinders and movable rods that cooperate with the hydraulic cylinders via pistons). The hydraulic cylinders of the two sets of hydraulic rods are mounted on both sides of the rotating base via two fourth revolute joints A4. Each fifth revolute joint A5 consists of a short shaft fixed to the swing arm and a hinged cylinder fixed to one end of the movable rod and rotatably engaged with the short shaft. The rotation axes of the two fifth revolute joints A5 are coaxially arranged. The fourth rotary joint A4 consists of a hinge sleeve fixed to the hydraulic cylinder and a hinge shaft fixed to the rotating base and rotatably engaged with the hinge sleeve. The hinge shaft is mounted on the rotating base via fourth rotary joint mounting seats 2.1 on both sides of the rotating base. Both ends of the hinge shaft extend outward from the left and right sides of the rotating base to rotatably engage with the hinge sleeve. The oil circuits of the two hydraulic rods are independent and set to the same oil pressure, ensuring torque balance between the two first robotic arms during operation.

[0040] A seventh revolute joint mounting base 4.3 is fixed at the lower part of the first robotic arm facing the second drive device 3. This mounting base is hinged to one end of the first drive rod 3.7 in the second drive device (the seventh revolute joint mounting base 4.3 and one end of the first drive rod 3.7 cooperate to form the seventh revolute joint). The other end of the first drive rod is hinged to the first slider 3.3 in the second drive device (the other end of the first drive rod and the first slider 3.3 cooperate to form the sixth revolute joint). Therefore, the movement of the first slider in the second drive device can sequentially drive the first robotic arm to swing through the sixth revolute joint A6, the first drive rod 3.7, and the seventh revolute joint A7.

[0041] Figure 4The diagram shows the driving mechanism of the third drive device 6 and the second robotic arm. The third drive device 6 is mounted on the rotating base via the third drive device mounting seat 5. The structure and connection of the third drive device are similar to those of the second drive device. Specifically, the second slider 6.1 and the second guide rail 6.2 cooperate to form a second sliding pair, and the second guide rail is horizontally mounted on the second drive device mounting seat. The second lead screw 6.3 is rotatably mounted on the second guide rail seat via brackets at both ends and is arranged parallel to the second guide rail. The third motor 6.5 is mounted on the end of the second guide rail seat (away from the first robotic arm) via the third motor seat 6.6, and the third motor is connected to the second lead screw via a second coupling. The second slider 6.1, which slides with the second guide rail seat, is also fixed with a second lead screw nut that meshes with the second lead screw. The second slider is also connected to the second robotic arm via a second drive rod 6.7.

[0042] One end of the second robotic arm 7 is hinged to the other end of the first robotic arm via a horizontally arranged rotating shaft (forming a third revolute joint A3). The other end of the second robotic arm is also hinged to the second drive rod 6.7 in the third drive device 6 via a horizontally arranged rotating shaft (forming a ninth revolute joint A9). The other end of the second drive rod is hinged to the second slider in the third drive device via a hinge shaft (forming an eighth revolute joint A8). The second guide rail is horizontally installed above the mounting base of the third drive device and its length direction is perpendicular to the third revolute joint.

[0043] The first guide rail of the second drive device and the second guide rail of the third drive device are parallel to each other. In order to expand the working angle of the flange and prevent interference with the movement of the first drive rod, the third drive device is installed further back than the second drive device (i.e., further away from the first robotic arm).

[0044] An end effector flange is mounted on the second robotic arm. The drive unit moves the second robotic arm, which in turn moves the flange.

[0045] Figure 1 The rotation axes of the second and third revolute joints are parallel to each other and arranged horizontally; and are also perpendicular to the rotation axis of the first revolute joint. The rotation axis of the first revolute joint is arranged vertically.

[0046] Figure 3 The rotation axes of the fourth, fifth, sixth, and seventh rotating joints are parallel to the rotation axis of the second rotating joint and perpendicular to the axis of the first guide rail seat of the first sliding joint.

[0047] Figure 4 The rotation axes of the eighth and ninth revolute joints are parallel to each other.

[0048] The first robotic arm, the second robotic arm, the third drive device, the mounting base of the third drive device, and the rotating base constitute a closed-loop structure. The second drive device, the first robotic arm, and the rotating base also constitute a closed-loop structure, which greatly improves the overall rigidity and heavy-load performance of the robot.

[0049] The high-rigidity heavy-duty robot with a closed-loop structure has three sets of drives. In the first drive device, the first motor drives the rotating base to rotate around the rotation axis of the first rotating joint through a gear set; in the second drive device, the second motor drives the first slider fixed to the nut to move through the first lead screw, thereby driving the first robotic arm to move around the rotation axis of the second rotating joint; in the third drive device, the third motor drives the second slider fixed to the nut to move through the second lead screw, thereby driving the second robotic arm to move around the rotation axis of the third rotating joint.

[0050] Example 2

[0051] like Figure 5 As shown, based on the original overall structure, the flange on the original second robotic arm is replaced with a working arm with three degrees of freedom. Specifically, the structure consists of a third robotic arm 8 rotatably positioned on the second robotic arm, a motor and transmission gear set (conventional structure, omitted from drawing) mounted on the second robotic arm for driving the third robotic arm, a fourth motor mounting base 9 rotatably positioned at the top of the third robotic arm, a fourth motor 10 mounted in the fourth motor mounting base, and an end flange 11 connected to the shaft end of the fourth motor. Clearly, the hinge structure between the bottom end of the third robotic arm and the second robotic arm forms the tenth revolute joint A10, and the hinge structure between the fourth motor mounting base and the top end of the third robotic arm forms the eleventh revolute joint A11.

[0052] Preferably, the axis of the tenth rotary joint is perpendicular to the axis of the third rotary joint and the length direction of the second robotic arm, and the axis of the eleventh rotary joint is perpendicular to the axis of the tenth rotary joint.

[0053] This working arm provides the robot with a pitch motion and two rotational motions, increasing the flexibility and functionality of the robotic arm's end effector.

Claims

1. A high-rigidity heavy-duty robot with a closed-loop structure, comprising an end effector flange (11) or a working arm with three degrees of freedom; characterized in that: The robot also includes a base (1) fixed to the ground, a rotating base (2) rotatably positioned on the top of the base about a vertical axis, a first drive unit installed in the rotating base to drive the rotating base to rotate, a first robotic arm (4) oscillatingly positioned on the rotating base about a horizontal axis, a second drive unit (3) installed on the rotating base to drive the first robotic arm to swing, a second robotic arm (7) connected to the top of the first robotic arm via a hinge shaft, a third drive unit (6) installed on the rotating base to drive the second robotic arm to swing, and two sets of hydraulic rods (12) installed between the rotating base and the first robotic arm to balance the torque; the second robotic arm is equipped with the end working flange or the working arm; The bottom end of the first robotic arm is pivotally positioned on the rotating base via a second rotating joint (A2). The second rotating joint includes a connecting shaft (4.1) arranged horizontally and fixed to the bottom end of the first robotic arm, and a bushing mounted on the rotating base and rotatably engaged with the connecting shaft. The hydraulic cylinders of the two sets of hydraulic rods are respectively oscillatingly positioned on both sides of the rotating base through the fourth rotating joint (A4), and the movable rod that cooperates with the hydraulic cylinder is connected to the top of the swing arm (4.2) through the fifth rotating joint (A5); the bottom end of the swing arm is fixed to the connecting shaft; The fourth rotating pair includes a hinge sleeve fixed to the hydraulic cylinder and a hinge shaft fixed to the rotating base and rotatably engaged with the hinge sleeve; the hinge shaft is horizontally mounted on the rotating base, and both ends of the hinge shaft extend outward from the left and right sides of the rotating base, thereby hinged to the hinge sleeve. The fifth revolute joint includes a short shaft fixed to the swing arm and a hinged cylinder fixed to one end of the movable rod and rotatably engaged with the short shaft; the rotation axes of the two fifth revolute joints are arranged coaxially.

2. The high-rigidity heavy-duty robot with a closed-loop structure according to claim 1, characterized in that: The second driving device includes a first gliding pair, a first lead screw pair, and a second motor (3.6) that drives the first gliding pair, all mounted on a rotating base and hinged to the first robotic arm. The first gliding pair includes a first guide rail (3.2) horizontally mounted on the rotating base and perpendicular to the rotation axis of the second gliding pair, and a first slider (3.1) that engages with the first guide rail. The first lead screw pair includes a first lead screw (3.3) mounted on the rotating base and parallel to the first guide rail, and a first lead screw nut that engages with the first guide rail and connects to the first slider. One end of the first driving rod (3.7) is hinged to the first robotic arm, and the other end is hinged to the first slider. The motor shaft of the second motor is connected to the first lead screw via a coupling.

3. The high-rigidity heavy-duty robot with a closed-loop structure according to claim 2, characterized in that: The third drive device (6) includes a third motor (6.5) mounted on the third drive device mounting base (5) and driving the second sliding pair via the second lead screw pair; the second sliding pair includes a second guide rail (6.2) horizontally mounted on the third drive device mounting base and perpendicular to the rotation axis of the second rotating pair, and a second slider (6.1) cooperating with the second guide rail; the second lead screw pair includes a second lead screw (6.3) mounted on the third drive device mounting base and parallel to the second guide rail, and a second lead screw nut cooperating with the second guide rail and connected to the second slider; one end of the second drive rod (6.7) is hinged to the second robotic arm, and the other end is hinged to the second slider; the motor shaft of the second motor is connected to the second lead screw via a coupling.

4. The high-rigidity heavy-duty robot with a closed-loop structure according to claim 3, characterized in that: One end of the second robotic arm (7) is connected to the top of the first robotic arm through the third rotating joint (A3), and the other end is connected to the second drive rod (6.7) in the third drive device through the ninth rotating joint (A9). The other end of the second drive rod is connected to the second slider through the eighth rotating joint (A8). The third rotating joint, the ninth rotating joint and the eighth rotating joint all include a horizontally arranged rotating shaft parallel to the rotation axis of the second rotating joint and a bushing that cooperates with the rotating shaft.

5. The high-rigidity heavy-duty robot with a closed-loop structure according to claim 4, characterized in that: The rotating base is rotatably positioned at the top of the base via a first rotating joint (A1) around a vertical axis. The first rotating joint includes a circular guide rail laid on the top of the base and several sliders installed at the bottom of the rotating base that cooperate with the circular guide rail. The first driving device includes two first motors (1.3) symmetrically mounted on the base plate (1.1), two first gears (1.4) mounted on the shafts of the two first motors, and a second gear (1.5) fixed at the bottom of the base and meshing with the two first gears.

6. The high-rigidity heavy-duty robot with a closed-loop structure according to claim 5, characterized in that: The three-degree-of-freedom working arm includes a third robotic arm (8) rotatably positioned on a second robotic arm, a motor and transmission gear set mounted on the second robotic arm for driving the third robotic arm, a fourth motor mounting base (9) rotatably positioned at the top of the third robotic arm, a fourth motor (10) mounted in the fourth motor mounting base, and an end working flange connected to the shaft end of the fourth motor.

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