Differential gear train structure, ankle joint, and robot

Abstract

The utility model discloses a differential gear train structure, ankle joint and robot, differential gear train structure includes cross axle, the cross axle includes the input shaft and output shaft of orthogonal setting, and the both ends of output shaft are respectively covered with first gear and second gear, and the both ends of input shaft are respectively provided with the third gear and fourth gear of the coordinated rotation with input shaft, and first gear and third gear and fourth gear are engaged respectively, and second gear and third gear and fourth gear are engaged respectively, and first gear and second gear are used for receiving acting force respectively, and will acting force transmission to input shaft, and differential gear train structure can receive the moment of two input sources transmission simultaneously, and will it become stable output rotation, both support active input, also superimposed passive intervention, be favorable to satisfy the demand of active and passive collaborative control. The scheme compact structure, transmission path is clear, is applicable to a variety of bionic joint or robot joint's application scene.

Description

Technical Field

[0001] This utility model relates to the field of robot joint structure technology, and in particular to a differential wheel system structure, an ankle joint, and a robot. Background Technology

[0002] Most existing differential drive structures are based on single input source control. In scenarios involving both active power input and passive damping response in the output, existing solutions generally suffer from unclear input paths and mutual interference, making it difficult to achieve synthetic control of dual inputs while ensuring transmission stability. Therefore, there is an urgent need for a versatile differential transmission structure suitable for complex input source control. Utility Model Content

[0003] The main purpose of this invention is to propose a differential wheel train structure, ankle joint, and robot, which aims to solve the problem that existing differential drive structures based on a single input source control are difficult to adapt to the application requirements of active / passive cooperative control.

[0004] To achieve the above objectives, this utility model proposes a differential gear train structure, comprising:

[0005] A cross shaft, comprising an orthogonally arranged input shaft and an output shaft;

[0006] The output shaft is fitted with a first gear and a second gear at its two ends, respectively.

[0007] The input shaft is provided with a third gear and a fourth gear at each end, which rotate in coordination with the input shaft.

[0008] The first gear meshes with the third gear and the fourth gear, respectively;

[0009] The second gear meshes with the third gear and the fourth gear, respectively;

[0010] The first gear and the second gear are respectively used to receive the applied force and transmit the applied force to the input shaft.

[0011] In some embodiments, the first gear, the third gear, the second gear, and the fourth gear mesh sequentially to form a closed meshing structure.

[0012] In some embodiments, the first gear and the second gear are respectively provided with a first mounting portion and a second mounting portion at their opposite ends, and the first mounting portion and the second mounting portion are respectively used to connect the first input mechanism and the second input mechanism that provide the force.

[0013] In some embodiments, the first input mechanism includes a motor, a worm gear disposed at the output end of the motor, and a worm wheel meshing with the worm gear;

[0014] The worm gear is coaxially arranged with the first gear and fixed on the first mounting part.

[0015] In some embodiments, the second input mechanism includes a damper and a linkage assembly for converting the linear motion output by the damper into rotational motion.

[0016] The linkage assembly includes a linkage connecting the damper and an eccentric wheel disposed at the other end of the linkage; the eccentric wheel is coaxially disposed with the second gear and fixed on the second mounting part.

[0017] In some embodiments, the first input mechanism, the first gear, the second gear, and the second input mechanism are all arranged sequentially along the output shaft axis.

[0018] In some embodiments, the third gear and the fourth gear are symmetrically arranged along the output shaft.

[0019] In some embodiments, a main housing is also included, wherein both the first input mechanism and the second input mechanism are disposed within the main housing;

[0020] The two ends of the output shaft are mounted on a support bracket, which is used to connect external devices;

[0021] The main housing is rotatably connected to the support frame via the output shaft.

[0022] This utility model also proposes an ankle joint, including an ankle joint body and a differential gear train structure disposed on the ankle joint body, wherein the differential gear train structure is the differential gear train structure described above.

[0023] This utility model also proposes a robot, including a robot body and an ankle joint disposed on the robot body, wherein the ankle joint is the ankle joint described above.

[0024] The beneficial effects of this utility model's technical solution are as follows: By setting an orthogonally connected input shaft and output shaft in a cross-shaft structure, and setting two gears at both ends of the output shaft—a first gear and a second gear—that simultaneously mesh with the gears at both ends of the input shaft, differential drive of a single output from two inputs is achieved. The input shaft can simultaneously receive the torques transmitted by two input sources, namely the first gear and the second gear, and synthesize them into a stable output rotation in a differential manner. This supports both active input and passive interference, which is beneficial for meeting the needs of active-passive coordinated control. Compared with existing devices that rely on a single power source, this solution has a compact structure, a clear transmission path, higher input redundancy, and control flexibility, making it suitable for various applications of bionic joints or robotic joints. Attached Figure Description

[0025] Figure 1 This is a partial structural diagram of the differential gear train structure provided in Embodiment 1 of this utility model;

[0026] Figure 2 This is a partial exploded view of the differential gear train structure provided in Embodiment 1 of this utility model;

[0027] Figure 3 This is a schematic diagram of the internal structure of the differential gear train structure provided in Embodiment 1 of this utility model;

[0028] Figure 4 This is a rear view of the differential gear train structure provided in Embodiment 1 of this utility model;

[0029] Figure 5 This is a schematic diagram of the overall structure of the ankle joint provided in Embodiment 2 of this utility model;

[0030] Explanation of icon numbers:

[0031] label name label name 1 cross shaft 11 Input axis 2 First gear 12 Output shaft 3 Second gear 21 First Installation Department 4 Third gear 31 Second Installation Department 5 Fourth gear 61 motor 6 First input mechanism 62 worm gear 7 Second input mechanism 63 worm gear 8 main housing 71 damper 9 support frame 72 link 100 Differential gear train structure 73 Eccentric wheel 200 ankle joint

[0032] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0034] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0035] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0036] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0037] Example 1

[0038] This embodiment proposes a differential gear train structure 100, referring to... Figures 1 to 4 ,include:

[0039] The cross shaft 1 includes an orthogonally arranged input shaft 11 and output shaft 12; the input shaft 11 and output shaft 12 form an integrated rigid connection structure so that when the input shaft 11 rotates around its own axis, the output shaft 12 can stably convert the rotation into a single degree of freedom output action.

[0040] The first gear 2 and the second gear 3 are respectively sleeved at both ends of the output shaft 12. The first gear 2 and the second gear 3 are rotatably mounted on the output shaft 12 through the bushing structure. During operation, they can rotate freely independently of the output shaft 12 without interfering with the rotation of the output shaft 12 body. The arrangement of the first gear 2 and the second gear 3 at both ends of the output shaft 12 is conducive to achieving a symmetrical arrangement of transmission elements. While ensuring functional independence, it makes the overall differential gear train structure 100 linear and symmetrical, which is convenient for compact installation and high integration design in space-constrained devices.

[0041] The input shaft 11 is provided with a third gear 4 and a fourth gear 5 at its two ends, which rotate in coordination with the input shaft 11. The third gear 4 and the fourth gear 5 are follower gear assemblies, which form an integrated rotating structure with the input shaft 11, that is, the three rotate synchronously. This structure makes it easy for the input shaft 11 to respond accurately to the torque changes from the third gear 4 and the fourth gear 5, and maintain the coordination and responsiveness of the differential structure.

[0042] The first gear 2 meshes with the third gear 4 and the fourth gear 5 respectively;

[0043] The second gear 3 meshes with the third gear 4 and the fourth gear 5 respectively;

[0044] The first gear 2 and the second gear 3 are used to receive the force and transmit the force to the input shaft 11. When the first gear 2 or the second gear 3 is subjected to an external input force, the torque is transmitted to the input shaft 11 through its meshing with the follower gear assembly, namely the third gear 4 and the fourth gear 5, causing the input shaft 11 to rotate and further driving the output shaft 12 to rotate, thereby realizing the integrated output of the force.

[0045] This embodiment achieves differential drive of a single output from two inputs by orthogonally connecting an input shaft 11 and an output shaft 12 within a cross-shaft 1 structure, and by setting two gears, a first gear 2 and a second gear 3, at both ends of the output shaft 12, which simultaneously mesh with the gears at both ends of the input shaft 11. The input shaft 11 can simultaneously receive the torques transmitted from two input sources, namely the first gear 2 and the second gear 3, and synthesize them into a stable output rotation in a differential manner. This supports both active input and passive interference, which is beneficial for meeting the requirements of active-passive coordinated control. Compared with existing devices that rely on a single power source, this scheme has a compact structure, a clear transmission path, and higher input redundancy and control flexibility.

[0046] In this embodiment, to meet the layout requirements of differential transmission and peripheral structure, the output shaft 12 is relatively long, running through the entire differential gear train structure 100, facilitating the placement of the first gear 2, the second gear 3, and their corresponding power input sources at both ends, thereby achieving stable torque output and mechanical support. The input shaft 11 is designed as a relatively short structure, mainly used to receive torque input from the third gear 4 and the fourth gear 5. To achieve a stable connection between the input shaft 11 and the output shaft 12, the input shaft 11 is located in the middle section of the output shaft 12 and is fixedly sleeved on the output shaft 12 through an integrally formed annular sleeve connection structure. This connection has a large coverage area and a firm positioning. Compared with the traditional cylindrical plug-in or pin connection method, it can effectively improve the structural strength and torsional stability of the cross shaft 1 under multi-source interference input, while also reducing fatigue wear and the risk of loosening at the connection point. Through the above design, the cross structure not only has a compact spatial layout and a clear transmission path, but also takes into account the transmission connection effect of high strength and high reliability.

[0047] Furthermore, the first gear 2, the third gear 4, the second gear 3, and the fourth gear 5 mesh sequentially to form a closed meshing structure; the meshing arrangement of the four gears forms a stable closed transmission loop, so that when the force is transmitted from the input end to the output end, a complete differential path is formed; this closed meshing structure can improve the transmission efficiency and the balance of torque distribution, while enhancing the self-stability of the overall structure, which helps to reduce the output jitter amplitude and ensure a smoother and more reliable rotational output.

[0048] Furthermore, the first gear 2 and the second gear 3 are respectively provided with a first mounting part 21 and a second mounting part 31 at their opposite ends. The first mounting part 21 and the second mounting part 31 are respectively used to connect the first input mechanism 6 and the second input mechanism 7 that provide the force. By providing the first mounting part 21 and the second mounting part 31, the input mechanism can be stably connected to the input gears of the differential gear train, namely the first gear 2 and the second gear 3, to achieve effective coupling of the input torque. This arrangement not only simplifies the installation structure of the input end assembly and the differential assembly, but also facilitates later replacement or maintenance. At the same time, it improves the structural independence and layout flexibility of each input mechanism and further enhances the modular design capability.

[0049] Furthermore, the first input mechanism 6 includes a motor 61, a worm gear 62 disposed at the output end of the motor 61, and a worm wheel 63 meshing with the worm gear 62; the power output by the motor 61 is transmitted to the meshing worm wheel 63 via the worm gear 62, and the worm wheel 63 further drives the first gear 2 to rotate, thereby applying the power to the differential gear train structure 100; using the worm wheel 63 and worm gear 62 structure for output can significantly improve the output accuracy of the motor 61 torque, while also ensuring smooth connection with the differential structure; the use of worm wheel 63 and worm gear 62 not only achieves stable unidirectional power output, but also has good self-locking capability, effectively preventing reverse rotation interference caused by external load reverse torque;

[0050] The worm gear 63 is coaxially arranged with the first gear 2 and fixed on the first mounting part 21. The coaxial arrangement and fixed connection between the worm gear 63 and the first gear 2 helps to simplify the structural hierarchy and realize direct and efficient power transmission. The worm gear 63 is located on the opposite side of the first gear 2, and the worm 62 is longitudinally arranged in front of or behind the worm gear 63. This arrangement is compact, helps to save space, and improves the integration and safety of the overall layout.

[0051] Furthermore, the second input mechanism 7 includes a damper 71 and a linkage assembly for converting the linear motion output by the damper 71 into rotational motion.

[0052] The linkage assembly includes a linkage 72 connecting the damper 71 and an eccentric wheel 73 disposed at the other end of the linkage 72. The eccentric wheel 73 is coaxially arranged with the second gear 3 and fixed on the second mounting part 31. The linear displacement output by the damper 71 is converted into the rotational motion of the eccentric wheel 73 via the linkage 72 assembly. The eccentric wheel 73 then drives the second gear 3 to rotate, thereby applying an interference torque to the differential structure. The coaxial arrangement and fixed connection between the eccentric wheel 73 and the second gear 3 helps to reduce backlash and energy loss during transmission. This arrangement not only enables efficient motion conversion but also provides a dynamically adjustable passive damping response without affecting the main drive of the cross shaft 1. At the same time, the arrangement of the eccentric wheel 73 makes the structure compact and the rotation smooth, which is beneficial for controlling the overall size and utilizing the assembly space.

[0053] Furthermore, the first input mechanism 6, the first gear 2, the second gear 3, and the second input mechanism 7 are all arranged sequentially along the axial direction of the output shaft 12; all key components are arranged linearly in the direction of the output shaft 12 to avoid stacked installation, which helps to reduce the risk of interference between components. This arrangement improves the operability of assembly and the stability of mechanism operation, while making the overall structure more compact and easy to integrate in a limited space, realizing bidirectional force coupling transmission to the output shaft 12.

[0054] Furthermore, the third gear 4 and the fourth gear 5 are symmetrically arranged along the output shaft 12; the gears at both ends of the input shaft 11 are symmetrically arranged so that the left and right sides are balanced in terms of meshing force, preventing uneven load or vibration of the output shaft 12 during torque transmission; this structure can improve the force symmetry and output stability of the differential system, and enhance the overall mechanical balance and service life of the system.

[0055] Furthermore, it also includes a main housing 8, and the first input mechanism 6 and the second input mechanism 7 are both located inside the main housing 8;

[0056] Both ends of the output shaft 12 are mounted on the support bracket 9, which is used to connect other external devices;

[0057] The main housing 8 is rotatably connected to the support frame 9 via the output shaft 12. By setting the main housing 8 to integrate two input mechanisms, the protective performance of the components and the overall assembly integrity can be improved. At the same time, the output shaft 12 serves as an intermediate connecting structure, enabling the main housing 8 to form a rotatable connection with the support frame 9. This gives the entire differential gear train structure 100 the modular capability to operate independently, making it easy to integrate into downstream devices such as prostheses, robots, and other systems. It also has good motion freedom and installation adaptability.

[0058] Example 2

[0059] This embodiment also proposes an ankle joint 200, as shown in the following example. Figure 5 It includes an ankle joint 200 body and a differential gear train structure 100 disposed on the ankle joint 200 body. The differential gear train structure 100 is the differential gear train structure 100 in Embodiment 1.

[0060] The ankle joint 200, through the integration of a differential gear train structure 100, can achieve coordinated control of active drive and passive damping, providing a more compact and responsive structural solution for the design of multi-degree-of-freedom lower limb bionic devices, and possessing good engineering application value and platform compatibility.

[0061] In some other embodiments, a robot is also proposed, including a robot body and an ankle joint 200 disposed on the robot body, wherein the ankle joint 200 is the ankle joint 200 in Embodiment 2.

[0062] By integrating an ankle joint 200 structure with differential transmission capability, this robot can achieve motion control that is closer to the physiological state in scenarios such as dynamic gait simulation and terrain adaptation. It is expected to be widely used in various occasions such as rehabilitation assistance, prosthetic devices and bionic robots.

[0063] The above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. A differential gear train structure, characterized in that, include: A cross shaft, comprising an orthogonally arranged input shaft and an output shaft; The output shaft is fitted with a first gear and a second gear at its two ends, respectively. The input shaft is provided with a third gear and a fourth gear at each end, which rotate in coordination with the input shaft. The first gear meshes with the third gear and the fourth gear, respectively; The second gear meshes with the third gear and the fourth gear, respectively; The first gear and the second gear are respectively used to receive the applied force and transmit the applied force to the input shaft.

2. The differential gear train structure according to claim 1, characterized in that, The first gear, the third gear, the second gear, and the fourth gear mesh sequentially to form a closed meshing structure.

3. The differential gear train structure according to claim 1 or 2, characterized in that, The first gear and the second gear are respectively provided with a first mounting part and a second mounting part at their opposite ends. The first mounting part and the second mounting part are respectively used to connect the first input mechanism and the second input mechanism that provide force.

4. The differential gear train structure according to claim 3, characterized in that, The first input mechanism includes a motor, a worm gear disposed at the output end of the motor, and a worm wheel meshing with the worm gear; The worm gear is coaxially arranged with the first gear and fixed on the first mounting part.

5. The differential gear train structure according to claim 4, characterized in that, The second input mechanism includes a damper and a linkage assembly for converting the linear motion output by the damper into rotational motion; The linkage assembly includes a linkage connecting the damper and an eccentric wheel disposed at the other end of the linkage; the eccentric wheel is coaxially disposed with the second gear and fixed on the second mounting part.

6. The differential gear train structure according to claim 5, characterized in that, The first input mechanism, the first gear, the second gear, and the second input mechanism are all arranged sequentially along the output shaft axis.

7. The differential gear train structure according to claim 2, characterized in that, The third gear and the fourth gear are symmetrically arranged along the output shaft.

8. The differential gear train structure according to claim 3, characterized in that, It also includes a main housing, and both the first input mechanism and the second input mechanism are located inside the main housing; The two ends of the output shaft are mounted on a support bracket, which is used to connect external devices; The main housing is rotatably connected to the support frame via the output shaft.

9. An ankle joint, characterized in that, The invention includes an ankle joint body and a differential gear train structure disposed on the ankle joint body, wherein the differential gear train structure is any one of claims 1 to 8.

10. A robot, comprising a robot body and an ankle joint disposed on the robot body, characterized in that, The ankle joint is the ankle joint as described in claim 9.

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