Robot joint assembly
By using left-hand and right-hand threaded connecting rods and anti-loosening nuts in the robot joint assembly, combined with self-lubricating zero-backlash rod end joint bearings, the problems of inaccurate pitch adjustment and loose noise in the robot joint connection structure are solved, achieving precise pitch adjustment and stable connection of the robot joint and improving motion accuracy.
Patent Information
- Application Number
- CN202422967786.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-12-03
AI Technical Summary
The existing connection structure at the robot joints cannot be precisely adjusted, causing the joint bearings at the rod ends to be out of plane and resulting in play that affects displacement control and flexibility, and is prone to abnormal noise and looseness.
The connecting rod has left-hand and right-hand threads at both ends, combined with anti-loosening nuts and self-lubricating zero-backlash rod end spherical bearings. The pitch adjustment is achieved through the adjustment of the linear actuator to achieve stepless pitch adjustment, ensuring that the spherical bearings are on the same plane and avoiding looseness and abnormal noise.
It achieves precise distance adjustment and stable connection of robot joints, improves motion accuracy, avoids abnormal noise and looseness issues, and is applicable to multiple moving joints of humanoid robots.
Smart Images
Figure CN223493286U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of robotics, specifically to a robot joint assembly. Background Technology
[0002] Modern humanoid robots are intelligent robots. For example, the ROBOT·X humanoid robot has up to 17 servos in its joints, giving it 17 degrees of freedom, making it exceptionally flexible and capable of performing complex movements such as swinging its arm 90 degrees backward. It also features a well-designed control system that can automatically complete the entire set of movements through its own intelligent programming software. Currently, these joint connections use linear actuators, but domestic robot companies generally report the following problems:
[0003] 1. For example Figure 1 The existing connection structure at the robot joint consists of a linear actuator 3', two rod end bearings 1', and two nuts 2'. Due to the structural requirements of the linear actuator, the connecting threads at both ends are right-hand threads. When adjusting the center distance of the two rod end bearings, the directions of rotation of the rod end bearings at both ends of the linear actuator are opposite. Therefore, it is impossible to precisely guarantee that the threads of the two rod end bearings are simultaneously screwed in or out by the same number of turns, i.e., it is impossible to guarantee that the end faces of the two rod end bearings are on the same plane. When selecting a linear actuator, the cumulative tolerances of the connecting components often cause the joint to fail to connect.
[0004] 2. The joint bearings used in the existing robot joint connection structure are of the standard SABP..S type. Taking the inner diameter of the bearing inner ring ≤12mm as an example, the clearance requirement is ≤0.035mm. When the linear actuator is working, the clearance on both sides will affect the control of its actual displacement. Moreover, since there are many linear actuators on the humanoid robot, when the accumulated clearance on a humanoid robot exceeds a certain value, it will cause the displacement error to accumulate, making it impossible to control the position accurately, thus affecting its flexibility and motion accuracy, and also easily causing abnormal noise and looseness. Utility Model Content
[0005] To address the shortcomings of existing technologies, this utility model provides a robot joint assembly, which mainly solves the problem that the two rod end joint bearings of the existing robot joint connection structure cannot be on the same plane after the distance is adjusted.
[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:
[0007] A robot joint assembly includes a linear actuator, two rod end bearings, three nuts, and a connecting rod. The two ends of the connecting rod are respectively provided with left-hand threads and right-hand threads. The end of the connecting rod with the right-hand external thread is connected to one end of the linear actuator through a nut. The end of the connecting rod with the left-hand thread is connected to one of the rod end bearings through a nut. The end of the linear actuator away from the connecting rod is connected to the other rod end bearing through a nut.
[0008] Preferably, the nut is a lock nut.
[0009] Preferably, the rod end joint bearing is a self-lubricating zero-backlash rod end joint bearing.
[0010] The robot joint assembly of this invention has the following beneficial effects:
[0011] 1. During robot joint installation, rotate the central linear actuator. Once adjusted to the desired position, tighten the nuts at both ends of the linear actuator to achieve stepless torque adjustment. The two rod-end bearings do not need to rotate, thus ensuring that the end faces of the two rod-end bearings are on the same plane. This method is suitable for connecting humanoid robot arms, legs, ankles, etc., enabling seamless connections at any point.
[0012] 2. The rod end joint bearings assembled in this robot joint assembly are self-lubricating zero-backlash rod end joint bearings, avoiding abnormal noise and looseness problems during use when the product space is limited. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of a robot joint connection structure in the prior art;
[0014] Figure 2 This is a schematic diagram of a robot joint assembly according to an embodiment of the present invention. Detailed Implementation
[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0016] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", 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.
[0017] like Figure 2As shown, this embodiment discloses a robot joint assembly, including a linear actuator 2, two rod end bearings 3, three nuts 4, and a connecting rod 1. The connecting rod 1 has a left-hand thread and a right-hand thread at both ends. The end of the connecting rod 1 with the right-hand external thread is connected to one end of the linear actuator 2 via a nut 4, and the end of the connecting rod 1 with the left-hand thread is connected to one of the rod end bearings 3 via a nut 4. The end of the linear actuator 2 away from the connecting rod 1 is connected to the other rod end bearing 3 via a nut 4. During robot joint installation, the central linear actuator 2 is rotated, and when adjusted to the desired position, the nuts 4 at both ends of the linear actuator 2 are locked, thereby achieving stepless torque adjustment. The two rod end bearings 3 do not need to rotate, thus ensuring that the end faces of the two rod end bearings 3 are in the same plane.
[0018] The nut 4 is a lock nut 4. Replacing the ordinary nut 4 with a lock nut 4 can significantly improve its anti-loosening performance.
[0019] Preferably, the rod end spherical bearings 3 at both ends of the linear actuator 2 are self-lubricating (or maintenance-free) zero-backlash rod end spherical bearings 3, which can be customized according to requirements to achieve zero backlash, thereby improving the overall accuracy of its operation and solving the problems of looseness and abnormal noise.
[0020] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model. Therefore, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
Claims
1. A robot joint assembly, characterized in that, It includes a linear actuator, two rod end bearings, three nuts, and a connecting rod. The two ends of the connecting rod are respectively provided with left-hand threads and right-hand threads. The end of the connecting rod with right-hand external threads is connected to one end of the linear actuator through a nut. The end of the connecting rod with left-hand threads is connected to one of the rod end bearings through a nut. The end of the linear actuator away from the connecting rod is connected to the other rod end bearing through a nut.
2. The robot joint assembly according to claim 1, characterized in that, The nut is a lock nut.
3. The robot joint assembly according to claim 1, characterized in that, The rod end bearing is a self-lubricating, zero-backlash rod end bearing.