A robot elbow joint power structure
By using worm gear pairs or gear sets for transmission and overall layout design, the problems of structural redundancy and insufficient transmission accuracy of traditional robot elbow joints are solved, realizing miniaturization of robot elbow joints and stable movement under high loads, and improving transmission accuracy and self-locking capability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG FANGDE ROBOT JOINT TECH CO LTD
- Filing Date
- 2025-05-29
- Publication Date
- 2026-07-03
AI Technical Summary
Traditional robot elbow joint structures suffer from structural redundancy, large space occupation, insufficient transmission accuracy, and limited self-locking and load-bearing capacity, making it difficult to meet the requirements of lightweight and high precision.
It adopts a worm gear pair or gear set transmission connection, combined with the overall layout design and built-in transmission system to form a compact triangular support structure. It utilizes the high reduction ratio and self-locking characteristics of the worm gear pair, and integrates a torque sensor to improve control accuracy and stability.
It achieves miniaturization, compactness, and motion stability under high loads in robot elbow joints, improves transmission accuracy and self-locking capability, and reduces structural complexity and energy consumption.
Smart Images
Figure CN224446016U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of robot joint module technology, and in particular relates to a power structure for a robot elbow joint. Background Technology
[0002] In the field of robot joint design, the elbow joint, as a core component for achieving multi-degree-of-freedom motion, directly affects the robot's motion performance and reliability due to the compactness of its power structure, transmission efficiency, and load-bearing capacity. Traditional robot elbow joints often employ direct motor drive or indirect transmission methods such as belts and chains to achieve joint rotation. However, such designs generally suffer from the following problems:
[0003] Structural redundancy and space occupation: The separate layout of motor and transmission mechanism results in large joint volume, which makes it difficult to meet the requirements of lightweighting. Especially in humanoid robots, the excessive joint size will limit the flexibility of movement.
[0004] Insufficient transmission accuracy and rigidity: Flexible transmission methods such as belts and chains are prone to elastic deformation, which leads to a decrease in positioning accuracy. They are also prone to slippage or wear under high load conditions, making it difficult to meet the high repeatability requirements of industrial robots.
[0005] Self-locking and limited load-bearing capacity: Although traditional gear or harmonic reducers can provide a certain transmission ratio, they lack reliable self-locking function. Under power failure or sudden load, they are prone to joint position displacement, which poses a safety hazard. Utility Model Content
[0006] To address the aforementioned technical problems, the purpose of this utility model is to provide a robot elbow joint power structure that is relatively compact and can ensure stable operation.
[0007] To achieve the above-mentioned objectives, this utility model adopts the following technical solution:
[0008] A robotic elbow joint power structure includes a first joint assembly, a second joint assembly, and a power mechanism. One end of the housing of the power mechanism is fixed to the first joint assembly, and the other end of the housing of the power mechanism is fixed to a rotating shaft via a connecting arm. The second joint assembly includes an outer sleeve and an inner connecting plate fixed inside the outer sleeve. The inner connecting plate is rotatably mounted on the rotating shaft via a bearing. The power mechanism and the inner connecting plate are connected by a worm gear pair or a gear set, so that the power mechanism drives the second joint assembly to rotate.
[0009] As a preferred embodiment, the power mechanism is a shutdown module, and a bevel gear is fixed at the output end of the joint module. A side gear disk is fixed on the inner side of the inner connecting plate, and the bevel gear meshes with the side gear disk for transmission.
[0010] As a preferred embodiment, the power mechanism is a shutdown module, and a worm gear is fixed to the output end of the joint module. A worm wheel is fixed to the inner side of the inner connecting plate, and the worm gear and the worm wheel mesh and transmit power.
[0011] As a preferred embodiment, there are two inner connecting plates, which are rotatably mounted at both ends of the rotating shaft, and a gap is left between the connection point of the inner connecting plate and the rotating shaft and the inner wall of the outer sleeve.
[0012] As a preferred embodiment, a torque sensor is also fixed between the side gear disk or worm gear and the inner connecting plate.
[0013] As a preferred embodiment, there are two connecting arms, one end of which is symmetrically fixed to both sides of the housing of the power mechanism, and the other end of which is fixed to both sides of the rotating shaft.
[0014] As a preferred embodiment, the rotating shaft is arranged perpendicular to the joint module, and the length of the rotating shaft is greater than the outer diameter of the joint module.
[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0016] This invention fixes one end of the power mechanism housing to the first joint assembly, and the other end is rigidly connected to the rotating shaft via a connecting arm, forming a stable triangular support structure, which reduces the cantilever torque of the power mechanism. Simultaneously, the rotational movement of the second joint assembly is entirely driven by the power mechanism through a worm gear pair or gear set. This design eliminates redundant intermediate transmission components, completely integrating the transmission system within the joint, significantly reducing the axial dimension.
[0017] In addition, this utility model adopts a worm gear pair as the preferred transmission method, which utilizes its single-stage large transmission ratio and reverse self-locking characteristics to ensure motion stability under high load, avoid the introduction of additional braking devices, simplify the structure and improve energy efficiency. Attached Figure Description
[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.
[0019] Figure 1 and Figure 2 These are schematic diagrams of the overall structure of this utility model from two different angles;
[0020] Figure 3 This is a schematic diagram of the installation structure of the first shutdown component and the second shutdown component of this utility model;
[0021] Figure 4 This is a structural schematic diagram of the first joint assembly, power mechanism, rotating shaft, and gear set of this utility model.
[0022] The attached figures are labeled as follows: 1. First joint assembly; 2. Outer sleeve; 21. Inner connecting plate; 3. Power mechanism; 30. Bevel gear; 31. Connecting arm; 32. Rotating shaft; 4. Bearing; 5. Torque sensor; 6. Side gear disk. Detailed Implementation
[0023] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0025] Furthermore, in the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.
[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0030] like Figures 1 to 4 As shown, a robot elbow joint power structure includes a first joint assembly 1, a second joint assembly, and a power mechanism 3. One end of the housing of the power mechanism 3 is fixed to the first joint assembly 1, and the other end of the housing of the power mechanism 3 is fixed to a rotating shaft 32 via a connecting arm 31. The second joint assembly includes an outer sleeve 2 and an inner connecting plate 21 fixed inside the outer sleeve 2. The inner connecting plate 21 is rotatably mounted on the rotating shaft 32 via a bearing 4. The power mechanism 3 and the inner connecting plate 21 are connected by a worm gear pair or a gear set, so that the power mechanism 3 drives the second joint assembly to rotate.
[0031] The worm gear / gear set transmission in the above structure provides a high reduction ratio to meet the high torque output requirements of the joint; the bearing support structure and the separate housing design realize the mechanical isolation between the power components and the load, extending the motor life; the external power mechanism layout breaks through the traditional axial integration limitation of the joint and optimizes the working space of the robotic arm.
[0032] The two specific transmission connection structures of the first joint assembly 1 and the second joint assembly mentioned above are as follows:
[0033] 1. The power mechanism 3 is a shutdown module, and a bevel gear 30 is fixed to the output end of the joint module. A side gear disk 6 is fixed to the inner side of the inner connecting plate 21, and the bevel gear 30 meshes with the side gear disk 6 for transmission. This type of bevel gear orthogonal transmission achieves efficient 90° conversion of power flow direction, adapting to compact layouts in confined spaces; at the same time, the gear pair has a large meshing contact area and strong load-bearing capacity, making it suitable for high-impact load scenarios.
[0034] 2. The power mechanism 3 is a shutdown module, and a worm gear is fixed to the output end of the joint module. A worm wheel is fixed to the inner side of the inner connecting plate 21, and the worm gear meshes with the worm wheel for transmission. The self-locking characteristic of the worm gear in this method achieves zero backlash position maintenance, eliminating the need for an additional braking device; and a high reduction ratio of 50-100 can be obtained with only a single-stage transmission, simplifying the transmission chain structure; at the same time, the line contact meshing method has vibration damping characteristics, improving motion stability.
[0035] Two inner connecting plates 21 are respectively rotatably mounted at both ends of the rotating shaft 32, and a gap is left between the connection point of the inner connecting plate 21 and the rotating shaft 32 and the inner wall of the outer sleeve 2. The above structure adopts a double-support point statically determinate structure to eliminate the bending moment of the rotating shaft and reduce the radial load on the bearing; at the same time, the gap design between the inner connecting plate and the outer sleeve forms a thermal expansion compensation space to prevent structural stress caused by temperature rise; the overall symmetrical layout makes the mass distribution uniform and reduces the imbalance of rotational inertia.
[0036] A torque sensor 5 is also fixed between the side gear disk 6 or worm gear and the inner connecting plate 21. In the above structure, the sensor is integrated in the middle of the transmission chain to avoid the influence of external interference signals; and the torque sensor 5 can measure the torque at the end of the transmission chain in situ, improving control accuracy; at the same time, through torque feedback closed-loop control, the nonlinear error of the transmission system is compensated.
[0037] Two connecting arms 31 are provided, with one end of each arm 31 symmetrically fixed to both sides of the housing of the power mechanism 3, and the other end fixed to both sides of the rotating shaft 32. The connecting arms employ a dual-point symmetrical support to even out stress distribution and extend service life. The symmetrical streamlined design reduces air resistance, making it suitable for high-speed mobile robots. The rotating shaft 32 is perpendicular to the joint module, and its length is greater than the outer diameter of the joint module. This ergonomic, biomimetic design allows for large-angle swinging, with a swing range of -100° to +150°.
[0038] This invention achieves extreme compactness of the joint structure while ensuring high-precision transmission through the coordinated layout of the power mechanism, connecting arm, and rotating shaft, as well as the integrated design of the internal connecting plate and bearings. This innovative design is particularly suitable for collaborative robots or bionic robotic arms that are space-sensitive and have stringent load requirements, providing a new technical path for the miniaturization and high performance of robot joints.
[0039] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0040] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.
Claims
1. A robotic elbow joint power structure, characterized by: The device includes a first joint assembly (1), a second joint assembly, and a power mechanism (3). One end of the housing of the power mechanism (3) is fixed to the first joint assembly (1), and the other end of the housing of the power mechanism (3) is fixed to a rotating shaft (32) via a connecting arm (31). The second joint assembly includes an outer sleeve (2) and an inner connecting plate (21) fixed inside the outer sleeve (2). The inner connecting plate (21) is rotatably mounted on the rotating shaft (32) via a bearing (4). The power mechanism (3) and the inner connecting plate (21) are connected by a worm gear pair or a gear set, so that the power mechanism (3) drives the second joint assembly to rotate.
2. The robot elbow joint power structure according to claim 1, wherein, The power mechanism (3) is a shutdown module, and a bevel gear (30) is fixed at the output end of the joint module. A side gear disk (6) is fixed on the inner side of the inner connecting plate (21), and the bevel gear (30) meshes with the side gear disk (6) for transmission.
3. The robotic elbow joint power structure of claim 1, wherein, The power mechanism (3) is a shutdown module, and the output end of the joint module is fixed with a worm gear. The inner side of the inner connecting plate (21) is fixed with a worm wheel, and the worm gear meshes with the worm wheel for transmission.
4. The robotic elbow joint power structure of claim 1, wherein, There are two inner connecting plates (21), which are respectively rotatably set at both ends of the rotating shaft (32), and there is a gap between the connection point of the inner connecting plate (21) and the rotating shaft (32) and the inner wall of the outer sleeve (2).
5. The robotic elbow joint power structure of claim 2, wherein, A torque sensor (5) is also fixed between the side gear disk (6) or worm gear and the inner connecting plate (21).
6. The robotic elbow joint power structure of claim 1, wherein, There are two connecting arms (31). One end of each connecting arm (31) is symmetrically fixed on both sides of the housing of the power mechanism (3), and the other end of each connecting arm (31) is fixed to both sides of the rotating shaft (32).
7. A robot elbow joint power structure according to claim 2 or 3, wherein The rotating shaft (32) is perpendicular to the joint module, and the length of the rotating shaft (32) is greater than the outer diameter of the joint module.