Mechanical arm

Abstract

The mechanical arm is used for being connected with an external accessory and comprises a first arm body, a second arm body and a third arm body which are sequentially connected, and the end, away from the second arm body, of the third arm body is connected with the external accessory; the first arm and the second arm are connected through a three-degree-of-freedom joint device, and the third arm and the external accessory are connected through a three-degree-of-freedom joint device. The three-degree-of-freedom joint device is located between the first arm and the second arm, and a power source of the three-degree-of-freedom joint device is installed in the first arm; the three-degree-of-freedom joint device is located between the third arm and the external accessory, and a power source of the three-degree-of-freedom joint device is distributed in the third arm in the axial direction of the third arm; the second arm and the third arm are connected through a two-degree-of-freedom joint device, a power source of the two-degree-of-freedom joint device is distributed in the second arm in the axial direction of the second arm, and the mechanical arm has the advantages of being flexible in movement and stable in structure.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and in particular to a robotic arm. Background Art

[0002] With the rapid development of robotics, people's requirements for robot functionality are becoming increasingly demanding, and they are no longer satisfied with a single motion mode. As the robot's execution structure, improving the flexibility of the robotic arm can effectively increase the robot's motion performance, allowing the robot to perform more sophisticated operations.

[0003] For example, Chinese patent publication number CN114434434A discloses a robotic arm with multiple connectors, each of which is connected by a joint motor. This design increases the flexibility of the robotic arm through the interaction of different joints. However, this solution has limited degrees of freedom for each joint, and each degree of freedom requires a joint motor to be placed at the joint node, which in turn increases the size and weight of the joint.

[0004] That is to say: the robotic arm in the above scheme is difficult to achieve high-precision control. If multiple joint motors are placed at the joints between two adjacent connecting rods, it is easy to cause the weight of both ends of the robotic arm to be heavy, which in turn easily causes the connecting rods to deform, affecting the flexible and stable operation of the robotic arm. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects in the prior art, thereby providing a robotic arm.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A robotic arm, for connecting to an external accessory, comprising a first arm, a second arm, and a third arm connected in sequence, wherein an end of the third arm away from the second arm is connected to the external accessory; The first arm and the second arm, and the third arm and the external accessory are connected via a three-degree-of-freedom joint device; The power source of the three-degree-of-freedom joint device located between the first arm and the second arm is installed in the first arm; the power source of the three-degree-of-freedom joint device located between the third arm and the external accessory is distributed in the third arm along the axis of the third arm; The second arm is connected to the third arm via a two-degree-of-freedom joint device, and a power source of the two-degree-of-freedom joint device is distributed in the second arm along the axial direction of the second arm.

[0007] Preferably, the three-degree-of-freedom joint device includes a first spherical shell component, a second spherical shell component, a first drive component, a second drive component and a third drive component; The second spherical shell component is movably mounted outside the first spherical shell component, and the center of the second spherical shell component coincides with the center of the first spherical shell component; Parts of the first drive assembly and the second drive assembly are both installed in the first spherical shell assembly and connected to the second spherical shell assembly to drive the second spherical shell assembly to rotate relative to the first spherical shell assembly about the first axis L1 and the second axis L2 respectively; The output end of the third drive assembly is connected to the first spherical shell assembly to drive the first spherical shell assembly, the second spherical shell assembly, the first drive assembly, and the second drive assembly to rotate synchronously with the third axis L3 as the rotation axis; The first axis L1 , the second axis L2 , and the third axis L3 are perpendicular to each other and intersect at the center of the first spherical shell assembly.

[0008] Preferably, the first driving assembly includes a first power source, a first transmission part and a first driven part; The first power source is fixedly mounted on the first arm or the third arm; One end of the first transmission part is connected to the first power source, and the other end is connected to the first driven part; The first driven part is installed in the first spherical shell component, and the output end of the first driven part is connected to the second spherical shell component; and / or, The second driving assembly includes a second power source, a second transmission part and a second driven part; The second power source is fixedly mounted on the first arm or the third arm; One end of the second transmission part is connected to the second power source, and the other end is connected to the second driven part; The second driven part is installed in the first spherical shell component, and the output end of the second driven part is connected to the second spherical shell component; and / or, The third driving assembly includes a third power source and a third transmission part. The third power source is fixedly installed on the first arm or the third arm.

[0009] Preferably, one end of the first transmission part is directly connected to the first power source or is connected to the first power source via a first universal joint transmission rod assembly; and / or; The second transmission part is directly connected to the second power source or is connected to the second power source via a first universal joint transmission rod assembly; and / or; The third transmission part is directly connected to the third power source in terms of power or is connected to the third power source through a first universal joint transmission rod assembly.

[0010] Preferably, the three-degree-of-freedom joint device also includes an inner support assembly installed in the first spherical shell assembly; the first follower is rotatably installed on the inner side of the inner support assembly, and the second follower is rotatably installed on the outer peripheral side of the inner support assembly, and the central axis of the first follower, the second follower, and the inner support assembly coincides with the second axis L2; ​​the inner support assembly includes a first support block and a second support block that are set against each other, and the first follower is rotatably installed in the area enclosed by the first support block and the second support block.

[0011] Preferably, the first spherical shell assembly comprises a first hemispherical shell and a second hemispherical shell arranged opposite to each other; the first hemispherical shell and the second hemispherical shell are each provided with a first extending semi-cylinder at one end away from the second spherical shell assembly, and the first extending semi-cylinder is rotatably connected to the first arm or the third arm via a bearing; and / or; The second spherical shell assembly includes a third hemispherical shell and a fourth hemispherical shell arranged opposite to each other. The third hemispherical shell and the fourth hemispherical shell are each provided with a second extended semi-cylinder at one end away from the first spherical shell assembly. The second extended semi-cylinder is used to be connected to a second arm or an external accessory.

[0012] Preferably, in the three-degree-of-freedom joint device located between the first arm and the second arm, the central axis of the first transmission shaft of the first transmission part coincides with the central axis of the second transmission shaft of the second transmission part, and the outer peripheral side of the first extended semi-cylinder is rotatably mounted on the first arm via a bearing; and / or, The three-degree-of-freedom joint device located between the third arm and the external accessory has a first transmission shaft of a first transmission part and a second transmission shaft of a second transmission part arranged in parallel.

[0013] Preferably, the first arm includes a first outer shell, a first mounting seat, and a bottom cover; the first outer shell has a first inner cavity; the first mounting seat is detachably mounted in the first inner cavity and is connected to the three-degree-of-freedom joint device; the bottom cover is detachably mounted on the bottom wall of the first outer shell to seal the port of the first inner cavity; the first mounting seat includes a first round seat and a sleeve connected in a circumferential direction; the first power source and the second power source are both fixedly mounted on the first round seat; the sleeve is connected to the third transmission part, and the third power source is fixedly mounted in the first outer shell; and / or, The second arm includes a second outer shell, a second mounting seat, and a second connecting rod; the second outer shell has a second inner cavity; a plurality of second mounting seats are provided, and the plurality of second mounting seats are installed in the second inner cavity along the axial direction of the second outer shell; the second connecting rod is used to connect adjacent second mounting seats, and the two ends of the second connecting rod are respectively fixedly connected to a part of the three-degree-of-freedom joint device and a part of the two-degree-of-freedom joint device; and / or, The third arm includes a third outer shell, a third mounting seat and a third connecting rod; the third outer shell has a third inner cavity; there are several third mounting seats, and several third mounting seats are axially installed in the third inner cavity along the third outer shell; the third connecting rod is used to connect adjacent third mounting seats, and the two ends of the third connecting rod are respectively fixedly connected to a part of the three-degree-of-freedom joint device and a part of the two-degree-of-freedom joint device.

[0014] Preferably, the two-degree-of-freedom joint device comprises a first joint block, a second joint block, a fourth drive assembly and a fifth drive assembly; The first joint block is rotatably mounted on an end of the second arm away from the first arm; The second joint block is fixedly mounted on the third arm and is rotatably connected to the first joint block with the centers coinciding; The fourth driving assembly is installed between the second arm, the first joint block and the second joint block to drive the second joint block to rotate relative to the first joint block along the fourth axis L4 as the rotation axis; The fifth driving assembly is mounted on the second arm to drive the first joint block, the second joint block and the third arm to rotate synchronously with the fifth axis L5 as the rotation axis; The fifth axis L5 coincides with the central axis of the second arm and is perpendicular to the fourth axis L4 , and the intersection of the fifth axis L5 and the fourth axis L5 is located at the center of the first joint block and the second joint block.

[0015] Preferably, the fourth drive assembly includes a fourth power source, a fourth drive shaft and a fourth bevel gear set, the fourth power source is fixedly installed in the second arm; the fourth drive shaft is rotatably installed relative to the first joint block, one end of the fourth drive shaft is connected to the fourth power source, and the other end is transmission-connected to the second joint block through the fourth bevel gear set; and / or, The fifth drive assembly includes a fifth power source, a fifth universal joint transmission rod assembly, and a fifth gear set. The fifth power source is fixedly installed in the second arm. One end of the fifth universal joint transmission rod assembly is connected to the fifth power source, and the other end is engaged with the first joint block through the fifth gear set for transmission.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a robotic arm in which a first arm and a second arm, as well as a third arm and an external accessory, are connected by a three-degree-of-freedom joint, while the second and third arms are connected by a two-degree-of-freedom joint. This allows the robotic arm to achieve eight degrees of freedom, offering greater flexibility than existing robotic arms that utilize joint motors to connect three connecting rods. The rational arrangement of the power sources for the three-degree-of-freedom joint and the two-degree-of-freedom joint ensures a more even distribution of the entire robotic arm structure, thereby bringing the overall center of gravity closer to the first arm, reducing the moment of inertia and facilitating the stable operation of the entire robotic arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a structural diagram of one example of the present invention.

[0019] Figure 2 Schematic diagram of the connection between the first arm and the three-degree-of-freedom joint device.

[0020] Figure 3 for Figure 2 Explosion diagram.

[0021] Figure 4 for Figure 2 A cross-sectional diagram from one of the viewing angles.

[0022] Figure 5 for Figure 2 A cross-sectional diagram from another perspective.

[0023] Figure 6 for Figure 2 Partial schematic diagram of the three-degree-of-freedom joint device.

[0024] Figure 7 for Figure 6 Explosion diagram.

[0025] Figure 8 Schematic diagram of the connection between the third arm and the three-degree-of-freedom joint device.

[0026] Figure 9 for Figure 8 Schematic cross-section diagram.

[0027] Figure 10 for Figure 8 Schematic diagram of the structure after removing the third outer shell.

[0028] Figure 11 for Figure 10 Schematic diagram of the D1 position in the image.

[0029] Figure 12 for Figure 8 Partial schematic diagram of the three-degree-of-freedom joint device.

[0030] Figure 13 for Figure 12 Explosion diagram.

[0031] Figure 14 Schematic diagram of the connection between the second arm and the two-degree-of-freedom joint device.

[0032] Figure 15 for Figure 14 Schematic cross-section diagram.

[0033] Figure 16 for Figure 15 Schematic diagram of the enlarged D2 position.

[0034] Figure 17 for Figure 15 A magnified schematic diagram of the D3 position in the figure.

[0035] Description of reference numerals: 1. First arm; 11. First outer shell; 110. First inner cavity; 12. First mounting seat; 121. First round seat; 122. Sleeve; 13. Bottom cover; 2. Second arm; 21. Second outer shell; 210. Second inner cavity; 22. Second mounting seat; 23. Second connecting rod; 3. Third arm; 31. Third outer shell; 310. Third inner cavity; 32. Third mounting seat; 33. Third connecting rod; 4. Three-degree-of-freedom joint device; 41. First Spherical shell assembly; 411, first hemispherical shell; 412, second hemispherical shell; 413, first extended semi-cylinder; 42, second spherical shell assembly; 421, third hemispherical shell; 422, fourth hemispherical shell; 423, second extended semi-cylinder; 43, first drive assembly; 431, first power source; 432, first transmission unit; 4321, first spur gear set; 4322, first transmission shaft; 4323, first bevel gear set; 433, first driven unit 4331, first driven shaft; 4332, first driven wheel; 4333, rack; 44, second drive assembly; 441, second power source; 442, second transmission unit; 4421, second spur gear set; 4422, second transmission shaft; 4423, second bevel gear set; 443, second driven unit; 4431, turntable; 4432, connecting shaft; 45, third drive assembly; 451, third power source; 452, third transmission unit; 46 , inner support assembly; 461, first support block; 462, second support block; 5, two-degree-of-freedom joint device; 51, first joint block; 52, second joint block; 53, fourth drive assembly; 531, fourth power source; 532, fourth drive shaft; 533, fourth bevel gear set; 54, fifth drive assembly; 541, fifth power source; 542, fifth universal joint transmission rod assembly; 543, fifth gear set; 6, first universal joint transmission rod assembly. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0039] See also Figures 1 to 17 An embodiment of the present invention provides a robotic arm for connecting to an external accessory. The robotic arm includes a first arm 1, a second arm 2, and a third arm 3 connected in sequence, and an end of the third arm 3 away from the second arm 2 is connected to the external accessory.

[0040] It's easy to understand that the first arm 1 can be fixedly connected to an external device (such as a rack) or an external fixed structure (such as the ground) to achieve fixed installation of the entire robotic arm. The external accessories provided with the third arm 3 can be configured as claws, clamps, push rods, and other structures to achieve functions such as gripping or pushing objects. These external accessories can also be connected to a bionic robotic hand to simulate a human hand (arm and palm) for more precise manipulation.

[0041] Specifically, the first arm 1 and the second arm 2, and the third arm 3 and the external accessory are connected through a three-degree-of-freedom joint device 4; the power source of the three-degree-of-freedom joint device 4 located between the first arm 1 and the second arm 2 is installed in the first arm 1; the power source of the three-degree-of-freedom joint device 4 located between the third arm 3 and the external accessory is distributed axially in the third arm 3; the second arm 2 and the third arm 3 are connected through a two-degree-of-freedom joint device 5, and the power source of the two-degree-of-freedom joint device 5 is distributed axially in the second arm 2.

[0042] It is easy to understand that in the above scheme, the first arm 1 and the second arm 2, and the third arm 3 and the external accessories are connected by a three-degree-of-freedom joint device 4, while the second arm 2 and the third arm 3 are connected by a two-degree-of-freedom joint device 5, so that the robot arm can achieve eight degrees of freedom. Compared with the existing robot arm with three connecting rods connected by joint motors, it has higher flexibility. The reasonable arrangement of the power source of the three-degree-of-freedom joint device 4 and the power source of the two-degree-of-freedom joint device 5 can make the entire robot arm structure more evenly distributed, and thus can bring the overall center of gravity closer to the first arm 1, reduce the motion inertia, and facilitate the stable operation of the entire robot arm.

[0043] The three-degree-of-freedom joint device 4 can be set to a variety of structures, which can be specifically set according to actual needs.

[0044] See also Figures 1 to 7 , taking the three-degree-of-freedom joint device 4 connected between the first arm 1 and the second arm 2 as an example, the three-degree-of-freedom joint device 4 includes a first spherical shell component 41, a second spherical shell component 42, a first drive component 43, a second drive component 44 and a third drive component 45.

[0045] Specifically, the second spherical shell assembly 42 is movably installed on the outside of the first spherical shell assembly 41, and the center of the second spherical shell assembly 42 coincides with the center of the first spherical shell assembly 41; parts of the first drive assembly 43 and the second drive assembly 44 are installed in the first spherical shell assembly 41 and are connected to the second spherical shell assembly 42 to drive the second spherical shell assembly 42 to rotate relative to the first spherical shell assembly 41 with the first axis L1 as the rotation axis and the second axis L2 as the rotation axis; the output end of the third drive assembly 45 is connected to the first spherical shell assembly 41 to drive the first spherical shell assembly 41, the second spherical shell assembly 42, the first drive assembly 43, and the second drive assembly 44 to rotate synchronously with the third axis L3 as the rotation axis; the first axis L1, the second axis L2 and the third axis L3 are perpendicular to each other and intersect at the center of the first spherical shell assembly 41.

[0046] Furthermore, the second spherical shell assembly 42 has two pairs of connection positions, wherein the output end of the first drive assembly 43 is connected to one pair of connection positions of the second spherical shell assembly 42 to drive the second spherical shell assembly 42 to rotate relative to the first spherical shell assembly 41 with the first axis L1 as the rotation axis; the output end of the second drive assembly 44 is connected to the other pair of connection positions of the second spherical shell assembly 42 to drive the second spherical shell assembly 42 to rotate relative to the first spherical shell assembly 41 with the second axis L2 as the rotation axis.

[0047] It is easy to understand that the connection position connected to the first drive assembly 43 is in the direction of the second axis L2, and the connection position connected to the second drive assembly 44 is in the direction of the first axis L1. In addition, the first axis L1, the second axis L2 and the third axis L3 are perpendicular to each other and intersect at the center C1 of the first spherical shell assembly 41 (that is, the center C1 of the second spherical shell assembly 42, see Figure 1 ), on the one hand, it can make the three-degree-of-freedom joint device 4 more compact; on the other hand, it can ensure that the three degrees of freedom of the first arm 1 and the second arm 2 are co-located at the same center C1 during movement. When the control system is used to control the three-degree-of-freedom joint device 4, the calculation and control process can be simplified. It is worth noting that the control system can be installed in the first inner cavity 110 of the first arm 1.

[0048] Specifically, the first spherical shell component 41 is connected to the first arm 1 in a rotationally fitting manner; and the second spherical shell component 42 is fixedly connected to the second arm 2 .

[0049] Specifically, the first drive assembly 43 includes a first power source 431, a first transmission unit 432, and a first driven unit 433. The first power source 431 is fixedly mounted on the first arm 1; one end of the first transmission unit 432 is connected to the first power source 431, and the other end is connected to the first driven unit 433; the first driven unit 433 is mounted within the first spherical shell assembly 41, and the output end of the first driven unit 433 is connected to the second spherical shell assembly 42.

[0050] Furthermore, the first transmission part 432 includes a first spur gear set 4321, a first transmission shaft 4322 and a first bevel gear set 4323, wherein the first spur gear set 4321 includes two meshing spur gears, one of which is fixedly connected to the first power source 431, and the other is fixed at one end of the first transmission shaft 4322; the second bevel gear set 4423 includes two meshing bevel gears, one of which is fixedly installed at one end of the first transmission shaft 4322 away from the first spur gear set 4321, and the other is fixedly connected to the first driven part 433 (specifically the first driven shaft 4331). The first driven part 433 includes a first driven shaft 4331, a first driven wheel 4332 and a rack 4333. The first driven shaft 4331 is rotatably connected relative to the first spherical shell assembly 41. The first driven wheel 4332 is fixedly installed on the first driven shaft 4331. The rack 4333 is fixedly installed in an arc groove on the second spherical shell assembly 42 and engages with the first driven wheel 4332 for transmission.

[0051] It is easy to understand that the rack 4333 is mounted on the side wall of the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the first axis L1.

[0052] Specifically, the second drive assembly 44 includes a second power source 441, a second transmission unit 442, and a second driven unit 443. The second power source 441 is fixedly mounted on the first arm 1; one end of the second transmission unit 442 is connected to the second power source 441, and the other end is connected to the second driven unit 443; the second driven unit 443 is mounted within the first spherical housing assembly 41, and the output end of the second driven unit 443 is connected to the second spherical housing assembly 42.

[0053] Specifically, the second transmission unit 442 includes a second spur gear set 4421, a second transmission shaft 4422, and a second bevel gear set 4423. The second spur gear set 4421 includes two meshing spur gears, one of which is fixedly connected to the second power source 441 and the other is fixedly connected to one end of the second transmission shaft 4422. The second bevel gear set 4423 includes a meshing bevel rack and a bevel gear. The bevel gear is fixedly mounted on the second transmission shaft 4422, and the bevel rack is fixedly mounted on the second driven unit 443 (specifically, the rotating disk 4431). The second driven unit 443 includes a rotating disk 4431 and a connecting shaft 4432 mounted on the rotating disk 4431. The connecting shaft 4432 passes through the arc guide provided on the first spherical shell assembly 41 and then connects to the second spherical shell assembly 42.

[0054] It is not difficult to understand that the central axis of the arc guide rail and the central axis of the turntable 4431 coincide with the second axis L2, and the central axis of the connecting shaft 4432 coincides with the first axis L1.

[0055] Furthermore, the third drive assembly 45 includes a third power source 451 and a third transmission part 452. The third power source 451 is fixedly mounted on the first arm 1. The third transmission part 452 can be configured as a transmission gear set, connected between the third power source 451 and the first spherical shell assembly 41.

[0056] In order to facilitate the assembly of the three-degree-of-freedom joint device 4, the first spherical shell assembly 41 includes a first hemispherical shell 411 and a second hemispherical shell 412 arranged opposite to each other; the first hemispherical shell 411 and the second hemispherical shell 412 are both provided with a first extended semi-cylinder 413 at one end away from the second spherical shell assembly 42, and the first extended semi-cylinder 413 is connected to the first arm 1 through a bearing.

[0057] Furthermore, the second spherical shell assembly 42 includes a third hemispherical shell 421 and a fourth hemispherical shell 422 arranged opposite to each other, and the third hemispherical shell 421 and the fourth hemispherical shell 422 are both provided with a second extended semi-cylinder 423 at one end away from the first spherical shell assembly 41, and the second extended semi-cylinder 423 is used to be connected to the second arm 2.

[0058] Furthermore, in the three-degree-of-freedom joint device 4 located between the first arm 1 and the second arm 2, the first transmission shaft 4322 of the first transmission part 432 coincides with the central axis of the second transmission shaft 4422 of the second transmission part 442, and the outer peripheral side of the first extended semi-cylinder 413 is rotatably mounted on the first arm 1 through a bearing.

[0059] It is easy to understand that the first transmission shaft 4322 and the second transmission shaft 4422 are coaxially arranged. At the same time, the first extending semi-cylinder 413 and the first arm 1 are rotatably connected by bearings, which can ensure the stability of the installation of the first spherical shell assembly 41.

[0060] See also Figures 4 to 7 The three-degree-of-freedom joint device 4 also includes an inner support assembly 46 installed in the first spherical shell assembly 41; the first follower part 433 is rotatably installed on the inner side of the inner support assembly 46, and the second follower part 443 is rotatably installed on the outer peripheral side of the inner support assembly 46, and the central axis of the first follower part 433, the second follower part 443, and the inner support assembly 46 coincides with the second axis L2.

[0061] It is easy to understand that the first driven portion 433 of the first drive assembly 43 and the second driven portion 443 of the second drive assembly 44 are coaxially mounted via the inner support assembly 46 and are both mounted within the first spherical shell assembly 41. This allows the first drive assembly 43 and the second drive assembly 44 to be more compactly distributed within the inner cavity of the first spherical shell assembly 41. This also ensures the stability of the installation of the first drive assembly 43 and the second drive assembly 44, facilitating stable operation of the first drive assembly 43 and the second drive assembly 44. Furthermore, the size of the three-degree-of-freedom joint device 4 can be reduced to a certain extent, resulting in a smaller footprint and a wider range of applications.

[0062] Specifically, the inner support assembly 46 includes a first support block 461 and a second support block 462 that are disposed against each other, and the first follower 433 is rotatably mounted within an area enclosed by the first support block 461 and the second support block 462 .

[0063] See also Figures 8 to 13 The three-degree-of-freedom joint device 4 located between the third arm 3 and the external accessory is different from the three-degree-of-freedom joint device 4 between the first arm 1 and the second arm 2 in that: the first transmission part 432 does not include the first spur gear set 4321, the second transmission part 442 does not include the second spur gear set 4421, and the first power source 431 and the first transmission part 432, the second power source 441 and the second transmission part 442, and the third power source 451 and the third transmission part 452 are all connected by power through the first universal joint transmission rod assembly 6, so that the first power source 431, the second power source 441 and the third power source 451 can be distributed axially along the third arm 3.

[0064] Specifically, the first extending semi-cylinder 413 of the three-degree-of-freedom joint device 4 is rotationally connected to the third arm 3 via a bearing, and the second extending semi-cylinder 423 is used to connect to external accessories.

[0065] Specifically, in the three-degree-of-freedom joint device 4 located between the third arm 3 and the external accessory, the first transmission shaft 4322 of the first transmission part 432 is arranged in parallel with the second transmission shaft 4422 of the second transmission part 442 .

[0066] See also Figures 1 to 17 The first arm 1 includes a first outer shell 11, a first mounting seat 12, and a bottom cover 13. The first outer shell 11 has a first inner cavity 110; the first mounting seat 12 is detachably mounted in the first inner cavity 110 and connected to the three-degree-of-freedom joint device 4; the bottom cover 13 is detachably mounted on the bottom wall of the first outer shell 11 to seal the port of the first inner cavity 110; the first mounting seat 12 includes a first round seat 121 and a sleeve 122 connected in a circumferentially limited manner; the first power source 431 and the second power source 441 are both fixedly mounted on the first round seat 121; the sleeve 122 is connected to the third transmission part 452, and the third power source 451 is fixedly mounted in the first outer shell 11.

[0067] Specifically, the second arm 2 includes a second outer shell 21, a second mounting seat 22, and a second connecting rod 23. The second outer shell 21 has a second inner cavity 210. A plurality of second mounting seats 22 are provided, and the plurality of second mounting seats 22 are axially mounted within the second inner cavity 210 along the second outer shell 21. The second connecting rod 23 is used to connect adjacent second mounting seats 22. The ends of the second connecting rod 23 are respectively fixedly connected to a portion of the three-degree-of-freedom joint device 4 and a portion of the two-degree-of-freedom joint device 5. Further, the third arm 3 includes a third outer shell 31, a third mounting seat 32 and a third connecting rod 33; the third outer shell 31 has a third inner cavity 310; a plurality of third mounting seats 32 are provided, and a plurality of third mounting seats 32 are axially installed in the third inner cavity 310 along the third outer shell 31; the third connecting rod 33 is used to connect adjacent third mounting seats 32, and the two ends of the third connecting rod 33 are respectively fixedly connected to a part of the three-degree-of-freedom joint device 4 and a part of the two-degree-of-freedom joint device 5.

[0068] Furthermore, the second arm 2 and the third arm 3 can be made of high-strength, lightweight, thin-walled tubular materials such as carbon fiber, magnesium-aluminum alloy, and titanium alloy.

[0069] It is easy to understand that this solution not only achieves stable installation of the first power source 431, the second power source 441, and the third power source 451, but also enables the third drive assembly 45 to drive the second drive assembly 44, the first drive assembly 43, the second spherical shell assembly 42, and the first spherical shell assembly 41 to operate synchronously. Furthermore, the arrangement of the second connecting rod 23 and the third connecting rod 33 ensures the structural strength of the second arm 2 and the third arm 3, and makes the structures that make up the second arm 2 and the third arm 3 separable for easy disassembly and transportation.

[0070] See also Figure 1 as well as Figures 14 to 17 In this embodiment, the two-degree-of-freedom joint device 5 includes a first joint block 51 , a second joint block 52 , a fourth driving assembly 53 and a fifth driving assembly 54 .

[0071] Specifically, the first joint block 51 is rotatably mounted on the end of the second arm 2 away from the first arm 1; the second joint block 52 is fixedly mounted on the third arm 3, and is rotatably connected to the first joint block 51 and their centers coincide with each other; the fourth drive assembly 53 is mounted between the second arm 2, the first joint block 51 and the second joint block 52 to drive the second joint block 52 to rotate relative to the first joint block 51 along the fourth axis L4 as the rotation axis; the fifth drive assembly 54 is mounted on the second arm 2 to drive the first joint block 51, the second joint block 52 and the third arm 3 to rotate synchronously with the fifth axis L5 as the rotation axis; the fifth axis L5 coincides with the central axis of the second arm 2 and is perpendicular to the fourth axis L4, and the intersection of the fifth axis L5 and the fifth axis L5 is located at the center C2 of the first joint block 51 and the second joint block 52 (see Figure 1 ).

[0072] Furthermore, the fourth drive assembly 53 includes a fourth power source 531, a fourth drive shaft 532 and a fourth bevel gear set 533. The fourth power source 531 is fixedly installed in the second arm 2; the fourth drive shaft 532 is rotatably installed relative to the first joint block 51, one end of the fourth drive shaft 532 is connected to the fourth power source 531, and the other end is connected to the second joint block 52 through the fourth bevel gear set 533.

[0073] Furthermore, the fifth drive assembly 54 includes a fifth power source 541, a fifth universal joint transmission rod assembly 542, and a fifth gear set 543. The fifth power source 541 is fixedly installed in the second arm 2. One end of the fifth universal joint transmission rod assembly 542 is connected to the fifth power source 541, and the other end is engaged and transmitted with the first joint block 51 through the fifth gear set 543.

[0074] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A robotic arm, used to connect to an external accessory, characterized in that: It comprises a first arm (1), a second arm (2) and a third arm (3) connected in sequence, wherein an end of the third arm (3) away from the second arm (2) is connected to the external accessory; The first arm (1) and the second arm (2), and the third arm (3) and the external accessory are connected via a three-degree-of-freedom joint device (4); A three-degree-of-freedom joint device (4) located between the first arm (1) and the second arm (2), wherein the power source is installed in the first arm (1); a three-degree-of-freedom joint device (4) located between the third arm (3) and the external accessory, wherein the power source is distributed in the third arm (3) along the axial direction of the third arm (3); The second arm (2) and the third arm (3) are connected via a two-degree-of-freedom joint device (5), and a power source of the two-degree-of-freedom joint device (5) is distributed in the second arm (2) along the axial direction of the second arm (2).

2. A robotic arm according to claim 1, characterized in that: The three-degree-of-freedom joint device (4) comprises a first spherical shell component (41), a second spherical shell component (42), a first drive component (43), a second drive component (44), and a third drive component (45); The second spherical shell component (42) is movably mounted outside the first spherical shell component (41), and the center of the second spherical shell component (42) coincides with the center of the first spherical shell component (41); Parts of the first drive assembly (43) and the second drive assembly (44) are both installed in the first spherical shell assembly (41) and connected to the second spherical shell assembly (42) to drive the second spherical shell assembly (42) to rotate relative to the first spherical shell assembly (41) with the first axis L1 as the rotation axis and the second axis L2 as the rotation axis respectively; The output end of the third drive assembly (45) is connected to the first spherical shell assembly (41) to drive the first spherical shell assembly (41), the second spherical shell assembly (42), the first drive assembly (43), and the second drive assembly (44) to rotate synchronously with the third axis L3 as the rotation axis; The first axis L1, the second axis L2 and the third axis L3 are perpendicular to each other and intersect at the center of the first spherical shell component (41).

3. A robotic arm according to claim 2, characterized in that: The first driving assembly (43) comprises a first power source (431), a first transmission part (432) and a first driven part (433); The first power source (431) is fixedly mounted on the first arm (1) or the third arm (3); One end of the first transmission part (432) is connected to the first power source (431), and the other end is connected to the first driven part (433); The first driven part (433) is installed in the first spherical shell component (41), and the output end of the first driven part (433) is connected to the second spherical shell component (42); and / or, The second driving assembly (44) comprises a second power source (441), a second transmission part (442) and a second driven part (443); The second power source (441) is fixedly mounted on the first arm (1) or the third arm (3); One end of the second transmission part (442) is connected to the second power source (441), and the other end is connected to the second driven part (443); The second driven part (443) is installed in the first spherical shell component (41), and the output end of the second driven part (443) is connected to the second spherical shell component (42); and / or, The third driving assembly (45) comprises a third power source (451) and a third transmission part (452), and the third power source (451) is fixedly mounted on the first arm (1) or the third arm (3).

4. A robotic arm according to claim 3, characterized in that: One end of the first transmission part (432) is directly connected to the first power source (431) in terms of power, or is connected to the first power source (431) in terms of power via a first universal joint transmission rod assembly (6); and / or; The second transmission part (442) is directly connected to the second power source (441) in terms of power, or is connected to the second power source (441) in terms of power via a first universal joint transmission rod assembly (6); and / or; The third transmission part (452) and the third power source (451) are directly connected in power or are connected in power via a first universal joint transmission rod assembly (6).

5. The robotic arm according to claim 3, characterized in that: The three-degree-of-freedom joint device (4) also includes an inner support assembly (46) installed in the first spherical shell assembly (41); the first driven part (433) is rotatably installed on the inner side of the inner support assembly (46), and the second driven part (443) is rotatably installed on the outer peripheral side of the inner support assembly (46), and the central axis of the first driven part (433), the second driven part (443), and the inner support assembly (46) coincides with the second axis L2; ​​the inner support assembly (46) includes a first support block (461) and a second support block (462) that are arranged against each other, and the first driven part (433) is rotatably installed in the area enclosed by the first support block (461) and the second support block (462).

6. The robotic arm according to claim 3, characterized in that: The first spherical shell component (41) comprises a first hemispherical shell (411) and a second hemispherical shell (412) arranged opposite to each other; the first hemispherical shell (411) and the second hemispherical shell (412) are both provided with a first extending semi-cylinder (413) at one end away from the second spherical shell component (42); the first extending semi-cylinder (413) is rotatably connected to the first arm (1) or the third arm (3) via a bearing; and / or; The second spherical shell component (42) comprises a third hemispherical shell (421) and a fourth hemispherical shell (422) that are arranged opposite to each other, and the third hemispherical shell (421) and the fourth hemispherical shell (422) are both provided with a second extended semi-cylinder (423) at one end away from the first spherical shell component (41), and the second extended semi-cylinder (423) is used to be connected to the second arm (2) or an external accessory.

7. The robotic arm according to claim 6, characterized in that: A three-degree-of-freedom joint device (4) located between the first arm (1) and the second arm (2), wherein the central axis of the first transmission shaft (4322) of the first transmission part (432) coincides with the central axis of the second transmission shaft (4422) of the second transmission part (442), and the outer peripheral side of the first extended semi-cylinder (413) is rotatably mounted on the first arm (1) via a bearing; and / or, The three-degree-of-freedom joint device (4) is located between the third arm (3) and the external accessory, wherein the first transmission shaft (4322) of the first transmission part (432) and the second transmission shaft (4422) of the second transmission part (442) are arranged in parallel.

8. A robotic arm according to claim 3 or 4, characterized in that: The first arm (1) comprises a first outer shell (11), a first mounting seat (12) and a bottom cover (13); the first outer shell (11) has a first inner cavity (110); the first mounting seat (12) is detachably mounted in the first inner cavity (110) and is connected to the three-degree-of-freedom joint device (4); the bottom cover (13) is detachably mounted on the bottom wall of the first outer shell (11) to seal the port of the first inner cavity (110); the first mounting seat (12) comprises a first round seat (121) and a sleeve (122) connected in a circumferential direction, and the first power source (431) and the second power source (441) are both fixedly mounted on the first round seat (121); the sleeve (122) is connected to the third transmission part (452), and the third power source (451) is fixedly mounted in the first outer shell (11); and / or, The second arm (2) comprises a second outer shell (21), a second mounting seat (22) and a second connecting rod (23); the second outer shell (21) has a second inner cavity (210); a plurality of second mounting seats (22) are provided, and the plurality of second mounting seats (22) are axially mounted in the second inner cavity (210) along the second outer shell (21); the second connecting rod (23) is used to connect adjacent second mounting seats (22), and both ends of the second connecting rod (23) are fixedly connected to a part of the three-degree-of-freedom joint device (4) and a part of the two-degree-of-freedom joint device (5), respectively; and / or, The third arm (3) comprises a third outer shell (31), a third mounting seat (32) and a third connecting rod (33); the third outer shell (31) has a third inner cavity (310); a plurality of third mounting seats (32) are provided, and the plurality of third mounting seats (32) are axially mounted in the third inner cavity (310) along the third outer shell (31); the third connecting rod (33) is used to connect adjacent third mounting seats (32), and the two ends of the third connecting rod (33) are respectively fixedly connected to a part of the three-degree-of-freedom joint device (4) and a part of the two-degree-of-freedom joint device (5).

9. The robotic arm according to claim 1, characterized in that: The two-degree-of-freedom joint device (5) comprises a first joint block (51), a second joint block (52), a fourth drive assembly (53) and a fifth drive assembly (54); The first joint block (51) is rotatably mounted on an end of the second arm (2) away from the first arm (1); The second joint block (52) is fixedly mounted on the third arm (3) and is rotatably connected to the first joint block (51) with their centers coinciding; The fourth drive assembly (53) is installed between the second arm (2), the first joint block (51) and the second joint block (52) to drive the second joint block (52) to rotate relative to the first joint block (51) along a fourth axis L4 as a rotation axis; The fifth drive assembly (54) is mounted on the second arm (2) to drive the first joint block (51), the second joint block (52) and the third arm (3) to rotate synchronously with the fifth axis L5 as the rotation axis; The fifth axis L5 coincides with the central axis of the second arm (2) and is perpendicular to the fourth axis L4, and the intersection of the fifth axis L5 and the fifth axis L5 is located at the center of the first joint block (51) and the second joint block (52).

10. The robotic arm according to claim 9, characterized in that: The fourth drive assembly (53) comprises a fourth power source (531), a fourth drive shaft (532) and a fourth bevel gear set (533); the fourth power source (531) is fixedly mounted in the second arm (2); the fourth drive shaft (532) is rotatably mounted relative to the first joint block (51); one end of the fourth drive shaft (532) is connected to the fourth power source (531), and the other end is transmission-connected to the second joint block (52) via the fourth bevel gear set (533); and / or, The fifth driving assembly (54) comprises a fifth power source (541), a fifth universal joint transmission rod assembly (542), and a fifth gear set (543). The fifth power source (541) is fixedly installed in the second arm (2). One end of the fifth universal joint transmission rod assembly (542) is connected to the fifth power source (541), and the other end is meshed with the first joint block (51) through the fifth gear set (543) for transmission.

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