Wrist module and robot

Abstract

This invention discloses a wrist module and a robot, relating to the field of robot technology. The wrist module includes a support, a universal joint, a first reducer, and a second reducer. The support includes a connecting portion, two first cantilever arms, two second cantilever arms, and a base. The two first cantilever arms are located on opposite sides of the support, and the two second cantilever arms are also located on opposite sides of the support. The first and second cantilever arms are respectively connected to the connecting portion and the base, with each first cantilever arm spaced apart from a second cantilever arm. The universal joint is rotatably connected to the support. The first reducer has a first end cap and a second end cap. The second reducer has a third end cap and a fourth end cap, with the third end cap located at the end of the second reducer facing the first reducer and close to the second end cap. The first and second reducers drive the universal joint to rotate. The support, second end cap, and third end cap are integrally formed. The technical solution provided by this invention can reduce assembly steps and decrease assembly complexity.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to a wrist module and a robot. Background Technology

[0002] With the rapid iteration and expansion of intelligent robot technology, the comprehensive performance requirements for joint drive systems in industrial collaborative robots, quadrupedal bionic robots, precision service robots, and special-purpose robots are continuously increasing. These systems not only need to meet the power output demands of high torque density, large reduction ratios, high-precision transmission, and low inertia response, but also impose stringent standards on the compactness of joint structures, assembly stability, overall reliability, and ease of maintenance. As the core execution unit for overall robot motion control, the robot joint directly determines the robot's motion accuracy, load capacity, dynamic response characteristics, and service life, making it a key component restricting the overall performance upgrade of robots.

[0003] In robot joint control scenarios involving high precision, heavy loads, and complex posture adjustments, single reducers, limited by their structural parameters, generally suffer from insufficient reduction ratios, limited torque amplification capabilities, large transmission accuracy deviations, and weak shock resistance, making it difficult to simultaneously meet the dual requirements of heavy load bearing and high-precision fine-tuning. To overcome the performance bottleneck of single reducers, existing technologies generally adopt a transmission structure with dual or multiple reducers working in tandem. By arranging multiple reducers in series, parallel, or combination, the overall reduction ratio and output torque of the joint are effectively improved, transmission rigidity is optimized, and the motion control requirements of robots with multiple degrees of freedom, heavy loads, and high precision under complex working conditions are met.

[0004] In terms of assembly process, the decentralized and independent supporting structure has extremely high requirements for assembly accuracy, process flow and tooling positioning. The superposition of multiple parts is prone to cumulative assembly errors. In addition, the complicated bolt connection and nested assembly structure not only lengthens the assembly process and reduces production assembly efficiency, but also greatly increases the difficulty of process control in mass production. Summary of the Invention

[0005] The main objective of this invention is to propose a wrist module and robot that aims to reduce assembly steps and simplify assembly.

[0006] To achieve the above objectives, the present invention provides a wrist module comprising: The bracket includes a connecting part, two first cantilever arms, two second cantilever arms, and a base. The two first cantilever arms are disposed on opposite sides of the bracket, and the two second cantilever arms are disposed on opposite sides of the bracket. The first cantilever arms and the second cantilever arms are respectively connected to the connecting part and the base, and each first cantilever arm and each second cantilever arm are spaced apart. Universal assembly, which is rotatably connected to the bracket; A first speed reducer, the first speed reducer having a first end cover and a second end cover; The second reducer has a third end cap and a fourth end cap, the third end cap being located at the end of the second reducer facing the first reducer and close to the second end cap; The first reducer and the second reducer drive the universal assembly to rotate, and the bracket, the second end cap and the third end cap are integrally formed.

[0007] In one embodiment, the first cantilever has a first plane facing the second cantilever, the second cantilever has a second plane facing the first cantilever, and the distance between the first plane and the second plane is 6 mm to 8 mm.

[0008] In one embodiment, the width of the first cantilever is 3.9 mm to 4.5 mm in a direction perpendicular to the first plane; Along a direction perpendicular to the second plane, the width of the second cantilever is 3.9 mm to 4.5 mm.

[0009] In one embodiment, the universal joint includes a universal joint and two transmission components. The middle part of the universal joint is rotatably connected to the bracket, and the opposite ends of the universal joint are respectively rotatably connected to one of the transmission components. The opposite ends of each transmission component are respectively rotatably connected to the universal joint and the bracket. The first reducer is drivenly connected to one of the transmission components, and the second reducer is drivenly connected to the other transmission component.

[0010] In one embodiment, the transmission assembly includes: A transmission component having a first mounting arm and a second mounting arm spaced apart, wherein one end of the transmission component away from the first mounting arm and the second mounting arm is connected to the first reducer or the second reducer; A connector that passes through the first mounting arm and connects to the second mounting arm; A first bearing, having a first inner ring and a first outer ring, rotatably connected, the first inner ring being sleeved on the connecting member and positioned between the first mounting arm and the second mounting arm; and A rotating component is connected to the first outer ring, and the end of the rotating component away from the transmission component is connected to the universal joint.

[0011] In one embodiment, the universal joint includes: Optical axis; The second bearing has a second inner ring and a second outer ring, which are rotatably connected. The second inner ring is sleeved on the outer peripheral wall of one end of the optical axis. Frame beam, the frame beam connecting to the second outer ring; and A limiting member is provided, which connects to the axial end face of the optical axis and abuts against the second inner ring in the axial direction of the optical axis.

[0012] In one embodiment, the limiting member includes an insertion section and a limiting section; The insertion segment is connected to the optical axis; The diameter of the limiting segment is larger than that of the insertion segment, the limiting segment is connected to the insertion segment, and abuts against the second inner ring; A limiting hole is formed on the end face of the optical axis; The insertion section is located inside the limiting hole and is connected to the wall of the limiting hole; The limiting segment is located outside the limiting hole.

[0013] In one embodiment, the optical axis is formed with a positioning groove; The bracket is provided with a support base, and the support base has a positioning protrusion. The positioning protrusion abuts against the groove wall of the positioning groove along the axial direction of the optical axis.

[0014] In one embodiment, the support base includes a support frame, a limiting sleeve, and a positioning pin; The support is mounted on the bracket; The limiting sleeve is connected to the support frame and is sleeved on the optical axis, and the limiting sleeve covers the positioning groove; The positioning pin passes through one side wall of the support frame and the limiting sleeve, and cooperates with the positioning groove. The positioning pin has the positioning protrusion.

[0015] The present invention also proposes a robot comprising the wrist module as described above.

[0016] In the technical solution of this invention, the traditional decentralized and independent assembly form is abandoned. The bracket, the second end cover and the third end cover are integrated into a single structure, eliminating the additional bolt connections and nested assembly structures between the three. This reduces the number of parts and assembly steps from the structural source, avoids the cumulative assembly error caused by the superposition of multiple parts, and reduces the stringent requirements on assembly accuracy, tooling positioning and process flow. This not only improves production assembly efficiency and simplifies process control for mass production, but also ensures the fixing accuracy and assembly stability of the relative positions of the two reducers, making the structure more compact, improving the overall reliability of the machine and making maintenance more convenient. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the wrist module provided by the present invention; Figure 2 This is a schematic diagram of another embodiment of the wrist module provided by the present invention; Figure 3 A schematic diagram of another embodiment of the wrist module provided by the present invention; Figure 4 A schematic diagram of a partial structure of the wrist module provided by the present invention; Figure 5 This is a schematic diagram of a structure of one embodiment of the bracket provided by the present invention; Figure 6 A schematic diagram of another embodiment of the bracket provided by the present invention; Figure 7 A schematic diagram of the structure of an embodiment of the transmission component provided by the present invention; Figure 8 A cross-sectional view of an embodiment of the transmission assembly provided by the present invention; Figure 9 A schematic diagram of a structure of an embodiment of the universal joint provided by the present invention; Figure 10 A cross-sectional view of an embodiment of the universal joint provided by the present invention; Figure 11 This is a cross-sectional view of another embodiment of the universal joint provided by the present invention.

[0019] Explanation of icon numbers: 1000. Wrist Module; 1. Bracket; 11. Connector; 12. First Cantilever; 121. First Plane; 13. Second Cantilever; 131. Second Plane; 14. Base; 141. Weight Reduction Hole; 142. Mounting Hole; 143. Clearance Groove; 2. First Reducer; 21. First End Cap; 22. Second End Cap; 23. First Output End; 3. Second Reducer; 31. Third End Cap; 32. Fourth End Cap; 33. Second Output End; 4. Universal Joint; 41. Optical Axis; 411. Limiting Hole; 412. Positioning Groove; 42. Second Bearing; 421. Second Inner Ring; 4211. Second Clearance Ring Groove; 422. Second Outer Ring; 4221. Dustproof End Cap; 43. Frame Beam; 431. Mounting Groove; 432. Clearance Hole; 433. Clearance Hole; 44. Limiting Component; 441 442. Insertion section; 442. Limiting section; 4421. Drive groove; 45. Support base; 451. Support frame; 452. Limiting sleeve; 4521. First sleeve part; 4522. Second sleeve part; 453. Positioning pin; 4531. Positioning protrusion; 4532. Guide part; 4533. Limiting umbrella part; 5. Transmission assembly; 51. Transmission component; 511. First mounting arm; 5111. Receiving hole; 512. Second mounting arm; 5121. Threaded hole; 52. Connecting component; 521. Connecting section; 522. Mounting section; 5221. Snap-fit ​​section; 5222. Support section; 5223. Adjustment groove; 53. First bearing; 531. First inner ring; 532. First outer ring; 54. Rotating component; 541. Annular protrusion; 542. Receiving groove; 55. Gasket; 56. Third bearing.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention 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 the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are 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. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] This invention proposes a wrist module 1000.

[0025] Please see Figure 1 , Figure 2 as well as Figure 4 In one embodiment of the present invention, the wrist module 1000 includes a support 1, a universal assembly, a first reducer 2, and a second reducer 3; the universal assembly is rotatably connected to the support 1; the first reducer 2 has a first end cap 21 and a second end cap 22; the second reducer 3 has a third end cap 31 and a fourth end cap 32, the third end cap 31 is located at the end of the second reducer 3 facing the first reducer 2 and close to the second end cap 22; wherein the first reducer 2 and the second reducer 3 drive the universal assembly to rotate, and the support 1, the second end cap 22, and the third end cap 31 are integrally formed structures.

[0026] In the technical solution of this invention, the traditional decentralized and independent assembly form is abandoned. The bracket 1, the second end cover 22 and the third end cover 31 are integrated into a single structure, eliminating the additional bolt connections and nested assembly structures between the three. This reduces the number of parts and assembly steps from the structural source, avoids the cumulative assembly error caused by the superposition of multiple parts, and reduces the stringent requirements on assembly accuracy, tooling positioning and process flow. This not only improves production assembly efficiency and simplifies process control for mass production, but also ensures the fixing accuracy and assembly stability of the relative positions of the two reducers, making the structure more compact, improving the overall reliability of the machine and making maintenance more convenient.

[0027] Specifically, in one embodiment of the present invention, please refer to... Figure 1 , Figure 2 , Figure 4 as well as Figure 5The bracket 1 includes a connecting part 11, two first cantilever arms 12, two second cantilever arms 13, and a base 14. The two first cantilever arms 12 are located on opposite sides of the bracket 1, and the two second cantilever arms 13 are located on opposite sides of the bracket 1. The first cantilever arms 12 and the second cantilever arms 13 are respectively connected to the connecting part 11 and the base 14. Each first cantilever arm 12 and a second cantilever arm 13 are spaced apart.

[0028] The support 1, serving as the load-bearing skeleton of the entire wrist joint, includes a connecting part 11, a base 14, and two first cantilever arms 12 and two second cantilever arms 13 connecting the connecting part 11 and the base 14. The connecting part 11 is used to mount various end effectors, while the base 14 is used for fixed connection to the forearm of the robotic arm or other upper-level structural components. The two first cantilever arms 12 are located on opposite sides of the support 1, and the two second cantilever arms 13 are also located on opposite sides of the support 1. Each first cantilever arm 12 and each second cantilever arm 13 are spaced apart from each other, forming a through gap between them. One end of each first cantilever arm 12 and each second cantilever arm 13 is connected to the connecting part 11, and the other end is connected to the base 14, thereby creating multiple independent force transmission paths between the connecting part 11 and the base 14.

[0029] Because the first cantilever 12 and the second cantilever 13 on each side are arranged at intervals, they can work together to form a couple when bearing the lateral force or torque transmitted from the connection part 11. This converts the torsional load into tensile and compressive loads on the cantilever, thereby significantly improving the overall torsional stiffness of the support 1. At the same time, this interval arrangement avoids excessive stress concentration in local areas of the support 1 due to concentrated arrangement, improves the stress uniformity of the structure, and helps to improve the fatigue life of the support 1. Since a single first cantilever 12 or second cantilever 13 does not need to use a large cross-sectional size, the overall weight of the support 1 can be effectively controlled.

[0030] In this embodiment, by using a first cantilever 12 and a second cantilever 13 to connect the connecting part 11 and the base 14, while ensuring structural strength, a single first cantilever 12 or second cantilever 13 does not need to have a large cross-sectional size, which helps to reduce the overall weight of the bracket 1.

[0031] Specifically, in one embodiment of the present invention, please refer to... Figure 1 , Figure 2 as well as Figure 5 The first cantilever 12 has a first plane 121 facing the second cantilever 13, and the second cantilever 13 has a second plane 131 facing the first cantilever 12. The distance between the first plane 121 and the second plane 131 is 6 mm to 8 mm.

[0032] The first plane 121 is the surface of the first cantilever 12 facing the second cantilever 13, and the second plane 131 is the surface of the second cantilever 13 facing the first cantilever 12. These two planes are positioned opposite each other and together define the gap width between the first cantilever 12 and the second cantilever 13. The gap L between them is controlled within the range of 6mm to 8mm. In a specific implementation, the gap L is set to 7mm. If the gap is set too small, the gap between the first cantilever 12 and the second cantilever 13 will not be sufficient to effectively achieve the weight reduction effect brought about by material removal. At the same time, an excessively narrow gap will also increase the difficulty of processing and manufacturing, and may cause interference due to micro-deformation of the structure during movement. If the gap is set too large, the first cantilever 12 and the second cantilever 13 will be too far apart. Although the torque arm formed between them will increase, the load-bearing path of a single cantilever will become too long, which may reduce the overall stiffness and load-bearing capacity of the support 1. Controlling the gap between 6mm and 8mm can achieve a good balance in several aspects. From a weight reduction perspective, this gap allows areas that might otherwise be filled with solid material to be hollowed out, creating an effective weight-reduction channel on each side of the support 1. Compared to a single large-section cantilever structure, the overall weight of the support 1 is significantly reduced. From a stiffness perspective, this spacing ensures that the first cantilever 12 and the second cantilever 13 can form a reasonable couple when subjected to lateral forces and torques. This leverages the synergistic load-bearing advantages of symmetrical arrangement while avoiding stiffness reduction due to excessive spacing. When this spacing is 7mm, the balance between the aforementioned weight reduction effect and structural stiffness is optimal, maintaining the high stiffness and high motion precision required by the wrist joint while minimizing weight reduction.

[0033] Specifically, in one embodiment of the present invention, please refer to... Figure 5 Along the direction perpendicular to the first plane 121, the width of the first cantilever 12 is 3.9mm to 4.5mm; along the direction perpendicular to the second plane 131, the width of the second cantilever 13 is 3.9mm to 4.5mm.

[0034] Specifically, along the direction perpendicular to the first plane 121, the width W1 of the first cantilever 12 is set within the range of 3.9mm to 4.5mm; correspondingly, along the direction perpendicular to the second plane 131, the width W2 of the second cantilever 13 is also set within the range of 3.9mm to 4.5mm. In a specific embodiment, the width W1 of the first cantilever 12 and the width W2 of the second cantilever 13 are both 4.2mm. Limiting the widths of the first cantilever 12 and the second cantilever 13 to the above-mentioned range is an optimization result obtained by combining finite element analysis and actual prototype testing, taking into account weight reduction requirements, structural stiffness, and manufacturability. If the width is set too large, exceeding 4.5mm, the thickness of a single cantilever increases. Although this can improve the bending stiffness of the cantilever itself, it will lead to a significant increase in the overall weight of the bracket 1, and will also reduce the available space between the first cantilever 12 and the second cantilever 13. If the width is set too small, below 3.9mm, the thickness of a single cantilever will be too thin, significantly increasing the bending deformation of the cantilever itself under external loads. This makes it difficult to guarantee the required motion accuracy and load-bearing reliability of the wrist joint, and also increases the risk of deformation or vibration during processing, adding to the manufacturing difficulty. Controlling the width between 3.9mm and 4.5mm, especially when the widths of the first cantilever 12 and the second cantilever 13 are both 4.2mm, achieves the best balance between weight reduction and structural stiffness. At this thickness, the first cantilever 12 and the second cantilever 13 have sufficient section modulus to resist bending deformation and can cooperate with the 6mm to 8mm cantilever spacing to form an ideal couple bearing mechanism, efficiently converting torsional loads into tensile and compressive loads on the cantilever, thus fully utilizing the torsional resistance advantage of the symmetrical spacing layout. At the same time, this thickness range allows the bracket 1 to achieve maximum material removal while meeting stiffness requirements, effectively reducing the overall weight of the wrist joint.

[0035] Specifically, in one embodiment of the present invention, please refer to... Figure 6 A weight-reducing hole 141 is formed in the middle of the base 14.

[0036] Specifically, after the weight-reducing holes 141 are provided, the base 14 is circular in shape. Two cantilever arms connect the base 14 and the connecting part 11. A large amount of space is left above the weight-reducing holes 141 for installing the drive components. The position of the weight-reducing holes 141 not only reduces the counterweight of the base 14, but also ensures that the base 14 maintains a uniform and symmetrical structure. In addition, the weight-reducing holes 141 can also assist the drive components in ventilation and heat dissipation, improving the overall heat dissipation performance of the machine.

[0037] Specifically, in one embodiment of the present invention, please refer to... Figure 6 The base 14 has multiple mounting holes 142, which are spaced apart.

[0038] Multiple mounting holes 142 enrich the mounting points of the base 14, which can be adapted to the assembly requirements of different installation stations; and the multi-point fixing method can improve the connection between the base 14 and the robot as a whole, prevent the joints from loosening under heavy load and frequent movement. The circular array layout of each mounting hole 142 can also avoid the reduction in strength of the base 14 caused by the dense mounting holes 142, and ensure its structural integrity and basic strength.

[0039] Specifically, in one embodiment of the present invention, please refer to... Figure 6 The end face of the base 14 facing away from the connecting part 11 has a relief groove 143, and each mounting hole 142 is provided on the bottom wall of the relief groove 143.

[0040] In this embodiment, the clearance groove 143 is actually for avoiding fasteners that pass through the mounting hole 142 for mounting the base 14. The groove opening of the clearance groove 143 (i.e. the lower end face of the base 14) can form a support to support and protect the fasteners. Furthermore, the groove sidewall of the clearance groove 143 is annular, which can serve as an assembly feature to enhance the connection strength between the base 14 and other external structures.

[0041] Specifically, in one embodiment of the present invention, please refer to... Figure 4 The first reducer 2 has a first output end 23, and the second reducer 3 has a second output end 33; the first output end 23 and the second output end 33 are located on the same rotation axis.

[0042] In this example, the coaxial arrangement of the first output end 23 and the second output end 33 can ensure that the power output direction is consistent, eliminate problems such as transmission jamming, torque loss, and accuracy deviation caused by different shaft transmissions, maximize the torque amplification and deceleration efficiency of the two reducers, improve transmission efficiency and transmission accuracy, and at the same time, the coaxial structure makes the joint motion trajectory more regular, accurately meeting the control requirements of the robot's multi-degree-of-freedom and high-precision posture adjustment.

[0043] Specifically, in one embodiment of the present invention, please refer to... Figure 1 and Figure 2 The universal joint assembly includes a universal joint 4 and two transmission components 5. The middle part of the universal joint 4 is rotatably connected to the bracket 1. The opposite ends of the universal joint 4 are respectively rotatably connected to a transmission component 5. The opposite ends of each transmission component 5 are respectively rotatably connected to the universal joint 4 and the bracket 1. The first reducer 2 is driven by one transmission component 5, and the second reducer 3 is driven by the other transmission component 5.

[0044] Specifically, the universal joint assembly includes a universal joint 4 and two transmission components 5. The universal joint 4, as the core motion conversion element, is connected to the bracket 1 via a rotating connector such as a shaft or bearing, allowing the universal joint 4 to rotate freely relative to the bracket 1 around a certain axis. The universal joint 4 has two opposing ends, each connected to one end of a transmission component 5 via a rotating connector, enabling relative rotation between the end of the universal joint 4 and the corresponding transmission component 5. Each transmission component 5 has two opposing ends, one end of which is rotatably connected to the corresponding end of the universal joint 4, and the other end is rotatably connected to the bracket 1.

[0045] Specifically, in one embodiment of the present invention, please refer to... Figure 1 and Figure 3 The universal joint 4 has a clearance hole 433. Along the length direction of the universal joint 4, the wall thickness of the two opposite side walls of the clearance hole 433 is 2.5 mm, and along the width direction of the universal joint 4, the wall thickness of the two opposite side walls of the clearance hole 433 is 4.0 mm.

[0046] Specifically, the universal joint 4 has clearance holes 433, which are through holes used for mounting and fixing robotic arms or various end effectors. Along the length of the universal joint 4, the wall thickness D1 of the two opposite sidewalls of the clearance holes 433 is set to 2.5 mm; along the width of the universal joint 4, the wall thickness D2 of the two opposite sidewalls of the clearance holes 433 is set to 4.0 mm. It should be noted that the length and width directions of the universal joint 4 refer to two orthogonal dimensions extending from the structure of the universal joint 4 itself. The length direction typically corresponds to the direction where the two ends of the universal joint 4 connect to the transmission assembly 5. The two sidewalls in this direction mainly bear tensile and compressive stresses along the length direction when the universal joint 4 transmits motion and bears loads. The width direction is approximately perpendicular to the length direction, and the two sidewalls in this direction bear more bending and shear stresses when the universal joint 4 is subjected to lateral forces or torques.

[0047] The relatively thin 2.5mm wall thickness of the two side walls along the length of the clearance hole 433 is based on the mechanical characteristics of this direction, where the forces are mainly tensile and compressive, and the requirement for bending section modulus is relatively low. While meeting the load-bearing and stiffness requirements in this direction, controlling the wall thickness to 2.5mm minimizes redundant material in this area, effectively reducing the weight of the universal joint 4. The relatively thick 4.0mm wall thickness of the two side walls along the width of the clearance hole 433 is due to the need for a larger bending section modulus and higher local stiffness when the wrist joint is laterally flexing or bearing lateral loads. The 4.0mm wall thickness ensures sufficient structural stiffness and load-bearing reliability in the width direction of the clearance hole 433 area without excessively increasing weight, preventing deformation or failure under lateral loads due to excessively thin walls, thus ensuring the stability and motion accuracy of the robot arm installation.

[0048] Specifically, in one embodiment of the present invention, please refer to... Figure 7 and Figure 8 The transmission assembly 5 includes a transmission component 51, a connecting component 52, a first bearing 53, and a rotating component 54. The transmission component 51 has a first mounting arm 511 and a second mounting arm 512 spaced apart. The end of the transmission component 51 away from the first mounting arm 511 and the second mounting arm 512 is connected to a first reducer 2 or a second reducer 3. The connecting component 52 passes through the first mounting arm 511 and connects to the second mounting arm 512. The first bearing 53 has a first inner ring 531 and a first outer ring 532, which are rotatably connected. The first inner ring 531 is sleeved on the connecting component 52 and is limited and installed between the first mounting arm 511 and the second mounting arm 512. The rotating component 54 is connected to the first outer ring 532, and the end of the rotating component 54 away from the transmission component 51 is connected to a universal joint 4.

[0049] In this embodiment, the transmission component 51 serves as the power input base, with a first mounting arm 511 and a second mounting arm 512 spaced apart to form a clamping mounting space. Its tail end directly connects to the reducer output shaft, responsible for receiving the reducer's power and completing the initial power transmission. The connecting component 52 passes through the two sets of mounting arms to complete the locking assembly, serving as the core positioning support shaft and providing reference support for the bearing and rotating component 54. The first bearing 53 is nested on the outside of the connecting component 52 and confined between the two sets of mounting arms, realizing the separation of the rotating support from the dynamic and static structures and avoiding direct friction between the fixed structure and the rotating structure. The rotating component 54 achieves free rotation by relying on the first bearing 53, with one end connected to the first outer ring 532 and the other end connected to the frame beam 43, constructing a complete power transmission link between the reducer and the frame beam 43. This solution establishes a bridge connecting the transmission component 51 and the rotating component 54 through the first bearing 53 and the connecting component 52, eliminating the transmission gap between the parts in the relative setting direction of the reducer and the frame beam 43 (i.e., the relative setting direction of the transmission component 51 and the rotating component 54). This effectively avoids the transmission backlash phenomenon, improves the problems of lag in the transmission of the robotic arm wrist joint and excessive rotation angle deviation, significantly improves the trajectory motion accuracy and repeatability accuracy of the end effector, suppresses the vicious cycle of accuracy deterioration caused by the continuous expansion of the gap, and significantly extends the service life of the wrist joint.

[0050] Specifically, in one embodiment of the present invention, please refer to... Figure 8 The connector 52 has a connecting section 521 and a mounting section 522; the connecting section 521 connects to the mounting section 522, the diameter of the connecting section 521 is smaller than the diameter of the mounting section 522, the connecting section 521 passes through the second mounting arm 512 and connects to the second mounting arm 512; the end face of the mounting section 522 facing the connecting section 521 abuts against the side wall of the second mounting arm 512 facing the first mounting arm 511.

[0051] In this embodiment, the diameter of the connecting section 521 is smaller than that of the mounting section 522. During assembly, the connecting section 521 with a smaller diameter penetrates the second mounting arm 512 and completes the fixed connection, while the mounting section 522 with a larger diameter fits against the side wall of the second mounting arm 512 facing the first mounting arm 511, forming a stepped limiting assembly structure. The difference in diameter creates an axial limiting step. On one hand, the stepped end-face contact structure enables precise axial positioning of the connector 52, preventing axial movement of the connector 52 during assembly and dynamic transmission, avoiding secondary fitting gaps caused by connector 52 displacement, and further ensuring the stability of the transmission reference. On the other hand, the segmented structure reduces assembly difficulty. The smaller diameter connecting section 521 facilitates insertion and alignment, while the larger diameter mounting section 522 increases the contact area with the second mounting arm 512, improving assembly fit and structural rigidity. Simultaneously, it can evenly distribute dynamic load impacts during transmission, avoiding deformation and loosening caused by localized stress concentration in the connector 52, and continuously ensuring the coaxiality and stability of the transmission link.

[0052] Specifically, in one embodiment of the present invention, please refer to... Figure 8 The first mounting arm 511 has a receiving hole 5111, the second mounting arm 512 has a threaded hole 5121, the connecting section 521 has an external thread, and the mounting section 522 has an adjusting groove 5223; the connecting section 521 is threadedly connected to the second mounting arm 512; part of the mounting section 522 is located inside the receiving hole 5111; the adjusting groove 5223 is located on the end face of the mounting section 522 facing away from the connecting section 521.

[0053] In this embodiment, during assembly, the connector 52 is threadedly locked and fixed to the threaded hole 5121 of the second mounting arm 512 via the external thread of the connecting section 521. A portion of the mounting section 522 is embedded inside the receiving hole 5111 of the first mounting arm 511, achieving radial limiting constraint. The adjusting groove 5223 is exposed on the end face of the mounting section 522, allowing for the use of specialized disassembly and assembly tools. This combination of rigid threaded locking and radial limiting via the receiving hole 5111 achieves gapless locking and fixation, preventing relative wobbling between the connector 52 and the mounting arm of the transmission component 51, thus eliminating transmission clearance from the assembly structure. Simultaneously, the design of the end face adjusting groove 5223 provides convenient stress points for equipment assembly and subsequent maintenance, significantly reducing the difficulty of equipment operation and maintenance. Furthermore, the structure of the mounting section 522 embedded in the receiving hole 5111 further improves the coaxiality of the connector 52 and the transmission component 51, ensuring accurate bearing rotation reference and avoiding wear and transmission deviation caused by eccentric rotation.

[0054] Specifically, in one embodiment of the present invention, please refer to... Figure 8The mounting section 522 includes a support section 5222 and a snap-fit ​​section 5221; the support section 5222 is connected to the snap-fit ​​section 5221, the diameter of the support section 5222 is smaller than that of the snap-fit ​​section 5221, and the end of the support section 5222 facing the connecting section 521 abuts against the side wall of the second mounting arm 512; the first inner ring 531 is fitted onto the support section 5222; the snap-fit ​​section 5221 is partially located in the receiving hole 5111 and has an adjustment groove 5223, and the end face of the snap-fit ​​section 5221 facing the second mounting arm 512 abuts against the first inner ring 531.

[0055] In this embodiment, a dual axial limiting structure is formed by the difference in diameter between the two segments to precisely limit and position the second mounting arm 512 and the first inner ring 531 of the first bearing 53. Firstly, the narrow-diameter support segment 5222 can precisely fit the inner diameter of the first inner ring 531 of the bearing, achieving a gapless fitting installation of the bearing, ensuring the coaxiality and smoothness of the bearing rotation, and avoiding frictional loss and transmission deviation caused by eccentric bearing operation. Secondly, the limiting structure at both ends can simultaneously constrain the axial displacement of the connecting piece 52 and the axial movement of the first inner ring 531 of the bearing, achieving precise positioning among the transmission component 51, the connecting piece 52, and the first bearing 53, eliminating axial clearance. Thirdly, the large-diameter snap-fit ​​segment 5221 can improve the overall structural support strength and load-bearing capacity, effectively resisting the dynamic load impact of the robotic arm's reciprocating operation, preventing structural deformation and loosening under long-term load, and continuously maintaining a high-precision transmission state.

[0056] Specifically, in one embodiment of the present invention, please refer to... Figure 8 The rotating component 54 has an annular protrusion 541 and two receiving grooves 542. The transmission assembly 5 includes two first bearings 53. The two side walls of the annular protrusion 541 respectively form a groove side wall of the two receiving grooves 542. The two first bearings 53 are respectively installed in the two receiving grooves 542. A first outer ring 532 is correspondingly connected to the groove bottom wall and groove side wall of a receiving groove 542. The two first bearings 53 are jointly confined between the first mounting arm 511 and the second mounting arm 512.

[0057] In this embodiment, the symmetrical dual-bearing support structure combined with the integrated limiting groove design of the annular protrusion 541 achieves precise positioning and symmetrical force distribution of the first bearing 53. This evenly distributes the radial load and torque impact during transmission, significantly improving the load-bearing capacity and operational stability of the transmission structure. It also avoids eccentric wear and transmission jamming caused by uneven force distribution on one side of a single bearing. The integrated annular protrusion 541 has high forming precision, ensuring the coaxiality and symmetry of the two receiving grooves 542, precisely constraining the bearing installation position, and preventing bearing assembly misalignment and wobbling. At the same time, the coordinated rotation of the dual bearings reduces the frictional load on the individual first bearing 53, reduces operational wear and abnormal noise, extends the bearing service life, and further improves the smoothness of movement and positioning accuracy of the overall transmission structure.

[0058] Specifically, in one embodiment of the present invention, please refer to... Figure 8 The connector 52 has a snap-fit ​​section 5221 and a support section 5222 connected to each other; the first inner rings 531 of the two first bearings 53 are sleeved on the support section 5222; the diameter of the snap-fit ​​section 5221 is larger than that of the support section 5222 and is located away from the second mounting arm 512; the end face of the snap-fit ​​section 5221 facing the support section 5222 abuts against the first inner ring 531 of one first bearing 53; the second mounting arm 512 abuts against the first inner ring 531 of the other first bearing 53.

[0059] In this embodiment, the first outer rings 532 of the two first bearings 53 are axially supported and limited between the two first bearings 53 by annular protrusions 541. The first inner rings 531 of the two first bearings 53 are clamped and limited by the end faces of the support sections 5222 on both sides and the side walls of the second mounting arm 512. This further solves the problem of axial movement and spacing deviation after the assembly of the two bearings, ensuring that the two bearings rotate coaxially and synchronously, and avoiding transmission jamming and angular deviation caused by bearing position deviation. At the same time, the limiting structure at both ends can offset the axial impact force generated by bidirectional dynamic load during transmission, prevent the bearings from loosening or shifting, and continuously maintain the reference accuracy of the transmission structure. In addition, the uniform support section 5222 sleeve structure ensures the assembly consistency of the first inner rings 531 of the two bearings, so that the two bearings are subjected to uniform force and operate synchronously, which greatly improves the stability and durability of the transmission system.

[0060] Specifically, in one embodiment of the present invention, please refer to... Figure 8 The transmission assembly 5 also includes a gasket 55; the gasket 55 abuts against the side wall of the second mounting arm 512 facing the first mounting arm 511 and abuts against the first inner ring 531 of the first bearing 53.

[0061] In this embodiment, the thickness compensation and flexible fit of the shim 55 achieve precise positioning of the first inner ring 531 of the first bearing 53. On the one hand, the shim 55 can accurately compensate for the minor tolerance errors caused by the machining and assembly of the parts, eliminate the slight fit gap between the first inner ring 531 and the second mounting arm 512, and achieve zero-gap positioning assembly. On the other hand, the shim 55 can play a role in buffering and shock absorption, absorbing the high-frequency dynamic impact load during the operation of the robotic arm, avoiding the rigid direct impact between the first inner ring 531 of the bearing and the mounting arm, reducing the wear and tear of the parts and abnormal noise during operation. At the same time, the shim 55 can disperse local contact stress, prevent the mounting arm and bearing end face from being squeezed for a long time to produce indentations and deformation, protect the structure of the core components, and extend the maintenance cycle and service life of the overall transmission assembly 5.

[0062] Specifically, in one embodiment of the present invention, please refer to... Figure 8The transmission assembly 5 also includes a third bearing 56; the axial direction of the third bearing 56 is orthogonal to the axial direction of the first bearing 53, and the third bearing 56 is used to connect the rotating part 54 and the frame beam 43 respectively.

[0063] In this example, the axial direction of the third bearing 56 is orthogonal to that of the first bearing 53. The two ends of the third bearing 56 are connected to the rotating component 54 and the frame beam 43, respectively, forming an orthogonal dual-dimensional bearing transmission structure. In terms of operational performance and structural adaptability, the orthogonally arranged dual bearings can adapt to different dimensions of wrist joint movement postures. The first bearing 53 adapts to the forward and backward swing of the frame beam 43, and the third bearing 56 adapts to the left and right swing. Multi-dimensional precise rotation support can significantly improve the movement flexibility and posture adjustment accuracy of the robotic arm's wrist joint, enriching the dimensions of operational movements. At the same time, the orthogonal bearing structure can distribute the load stress in different directions, avoiding the problem of accelerated wear and precision failure caused by a single bearing bearing multi-directional loads, improving the structural stability under multi-posture operation conditions, and allowing the robotic arm to adapt to complex and multi-directional precision operation scenarios.

[0064] Specifically, in one embodiment of the present invention, a dust cover is formed on the first outer ring 532; the dust cover extends toward the first inner ring 531 and is spaced apart from the first inner ring 531 in the radial direction.

[0065] The robot's working environment often generates dust and fine debris, and under some working conditions, it may also come into contact with moisture and oil. Once these impurities enter the rotating mating surfaces inside the bearing, they will directly aggravate the wear of the bearing rolling elements, the first inner ring 531, and the first outer ring 532, and may also cause rotational jamming and reduced accuracy.

[0066] In this embodiment, the dust cover extends towards the first inner ring 531 of the bearing and maintains a fixed radial distance from the first inner ring 531, ensuring that they do not contact each other. The added dust cover effectively creates a protective barrier on the outside of the bearing, preventing external dust, debris, moisture, and other impurities from entering the bearing and providing comprehensive protection for the bearing's mating structure. The radially reserved gap ensures that the dust cover will not rub or scrape against the rotating first inner ring 531 of the bearing, avoiding interference with the bearing's normal rotation. This achieves dust protection while ensuring that the frame beam 43 rotates flexibly and smoothly.

[0067] Specifically, in one embodiment of the present invention, the first inner ring 531 is formed with a first clearance annular groove; the first clearance annular groove is recessed from the outer peripheral wall of the first inner ring 531 and is directly opposite the dust cover in the radial direction of the first inner ring 531, and the bottom of the first clearance annular groove is spaced apart from the dust cover.

[0068] During long-term load operation and frequent posture switching, the components of the robot wrist joint will undergo slight elastic deformation. At the same time, vibration and temperature changes will also cause slight radial displacement of the first inner ring 531 of the bearing. Without a clearance structure, the dust cover can easily cause frictional interference with the first inner ring 531.

[0069] In this embodiment, the radial clearance space is further expanded by the first clearance ring groove on the first inner ring 531. Even if the first inner ring 531 of the bearing has a slight displacement or deformation, the situation of contact or scraping between the dust cover and the first inner ring 531 of the bearing can be completely avoided. On the one hand, the dust cover and the bearing body are protected from damage, and on the other hand, the frictional resistance is prevented from increasing and affecting the rotational accuracy. This allows the bearing to maintain a stable and low-resistance operating state for a long time. In addition, the groove wall of the first clearance ring groove and the dust cover are spaced apart in the axial direction, but their projections in the axial direction overlap, which can further improve the dustproof and impurity-proof effect and ensure the service life of the parts.

[0070] Specifically, in one embodiment of the present invention, please refer to... Figure 9 and Figure 10 The universal joint 4 includes an optical shaft 41, a second bearing 42, a frame beam 43, and a limiting member 44. The second bearing 42 has a second inner ring 421 and a second outer ring 422, which are rotatably connected. The second inner ring 421 is sleeved on the outer peripheral wall of one end of the optical shaft 41. The frame beam 43 is connected to the second outer ring 422. The limiting member 44 is connected to the end face of the optical shaft 41 in the axial direction and abuts against the second inner ring 421 in the axial direction of the optical shaft 41.

[0071] In this embodiment, the second bearing 42 is composed of a second inner ring 421 and a second outer ring 422 that can rotate relative to each other. During assembly, the second inner ring 421 of the second bearing 42 is tightly fitted onto the outer circular surface of the end of the optical shaft 41, and the frame beam 43 is stably connected to the second outer ring 422 of the second bearing 42. Relying on the rotational characteristics between the inner and outer rings 422 of the second bearing 42, the frame beam 43 can smoothly complete the rotation around the optical shaft 41, thereby driving the subsequently installed palm connector to achieve posture adjustment. The limiting member 44 is installed and fixed on the axial end face of the optical shaft 41. After assembly, the side of the limiting member 44 facing the second bearing 42 forms an axial abutment with the second inner ring 421 of the second bearing 42. This universal joint 4 changes the traditional approach to eliminating backlash. It uses the second bearing 42 as a rotational support structure and forms a rigid axial limiting structure with the limiting component 44. It no longer relies on easily failing shims. The limiting component 44 firmly holds the second inner ring 421 of the second bearing 42 in the axial direction, limiting the displacement of the second inner ring 421 of the second bearing 42 and the optical axis 41 in the axial direction, thus suppressing the axial movement phenomenon that occurs during the operation of the whole machine from the root.

[0072] Specifically, in one embodiment of the present invention, please refer to... Figure 10 The limiting member 44 includes an insertion section 441 and a limiting section 442; the insertion section 441 is connected to the optical axis 41; the diameter of the limiting section 442 is larger than that of the insertion section 441, the limiting section 442 is connected to the insertion section 441, and abuts against the second inner ring 421.

[0073] In this embodiment, the limiting member 44 is divided into two functional areas: an insertion section 441 and a limiting section 442. The relatively small insertion section 441 serves as the assembly base, primarily responsible for fixing the limiting member 44 to the end of the optical shaft 41, ensuring that the limiting member 44 is integrated with the optical shaft 41 without loosening or shifting. The limiting section 442 connects to the outside of the insertion section 441, and its outer diameter is significantly larger than that of the insertion section 441. The end face of the limiting section 442 directly forms an axial abutment contact with the second inner ring 421 of the second bearing 42. The large-diameter limiting section 442 increases the contact area with the second inner ring 421 of the second bearing 42, allowing the axial clamping force to be evenly distributed on the end face of the second inner ring 421 of the second bearing 42, preventing uneven wear or clamping failure due to localized stress concentration. Under conditions of continuous reciprocating rotation and dynamic load, this structure can always maintain a stable axial limiting effect, further enhancing the ability to prevent axial movement, avoiding failure of the limiting structure due to uneven force, and ensuring stable operation of the wrist joint for a long time.

[0074] Specifically, in one embodiment of the present invention, please refer to... Figure 10 The end face of the optical axis 41 forms a limiting hole 411; the insertion section 441 is located inside the limiting hole 411 and is connected to the hole wall of the limiting hole 411; the limiting section 442 is located outside the limiting hole 411.

[0075] In this embodiment, the insertion segment 441 is embedded within the limiting hole 411 at the end of the optical axis 41. This fully utilizes the internal space at the end of the optical axis 41, effectively reducing the overall axial dimension of the universal joint 4 and making the internal structure of the wrist joint more compact. This is suitable for the design characteristics of lightweight robot wrist joints, which are characterized by limited space and dense structure. At the same time, the embedded installation method allows the optical axis 41 body to provide physical protection for the insertion segment 441, preventing external impacts, dust scratches, and interference from moving parts during equipment operation from affecting the insertion segment 441 inside the limiting hole 411. This significantly improves the reliability of the connection structure between the limiting member 44 and the optical axis 41, reducing the probability of components becoming loose due to external factors.

[0076] Specifically, in one embodiment of the present invention, please refer to... Figure 9 and Figure 10The limiting hole 411 has an internal thread, the insertion section 441 has an external thread, and the limiting member 44 has a driving groove 4421; the insertion section 441 is threadedly connected to the limiting hole 411; the driving groove 4421 is located on the end face of the limiting member 44 facing away from the optical axis 41.

[0077] In this embodiment, the optical shaft 41 and the limiting member 44 are detachably fixedly connected by a threaded engagement. Simultaneously, a drive groove 4421 is machined on the outer end face of the limiting member 44 facing away from the optical shaft 41, for use with a dedicated disassembly and assembly tool. The threaded connection features reliable locking and convenient adjustment. Assembly personnel can flexibly adjust the screw-in depth by rotating the limiting member 44, precisely controlling the axial clamping force of the limiting member 44 on the second inner ring 421 of the second bearing 42. This completely eliminates the axial assembly gap between the second bearing 42 and the optical shaft 41, and avoids problems such as overload and rotational jamming of the second bearing 42 due to excessive clamping force, achieving precise control of the gap. The drive groove 4421 on the end face of the limiting member 44 can be operated with a corresponding screwdriver. Whether for initial assembly and debugging or later equipment maintenance and parts replacement, the disassembly and assembly of the limiting member 44 can be completed quickly, significantly improving assembly and maintenance efficiency and reducing the difficulty of manual operation.

[0078] Specifically, in one embodiment of the present invention, please refer to... Figure 10 The second outer ring 422 is formed with a dustproof end cap 4221; the dustproof end cap 4221 extends toward the second inner ring 421 and is radially spaced from the second inner ring 421 on the optical axis 41.

[0079] The robot's working environment often generates dust and fine debris, and under some working conditions, it may also come into contact with moisture and oil. Once these impurities enter the rotating mating surface inside the second bearing 42, they will directly aggravate the wear of the rolling elements, the second inner ring 421, and the second outer ring 422 of the second bearing 42, and may also cause rotational jamming and reduced accuracy.

[0080] In this embodiment, the dustproof end cap 4221 extends towards the second inner ring 421 of the second bearing 42 and maintains a fixed radial distance from the second inner ring 421 of the second bearing 42, with the two not contacting each other. The added dustproof end cap 4221 is equivalent to building a protective barrier on the outside of the second bearing 42, which can effectively prevent external dust, debris, moisture and other impurities from entering the interior of the second bearing 42, and protect the mating structure of the second bearing 42 in all directions; while the radially reserved gap can ensure that the dustproof end cap 4221 will not rub or scratch the second inner ring 421 of the second bearing 42 in the rotating state, and avoid the dustproof end cap 4221 interfering with the normal rotation of the second bearing 42. While achieving dust protection, it also ensures that the frame beam 43 rotates flexibly and smoothly.

[0081] Specifically, in one embodiment of the present invention, please refer to... Figure 10 The second inner ring 421 has a second clearance annular groove 4211. The second clearance annular groove 4211 is recessed from the outer peripheral wall of the second inner ring 421 and is directly opposite the dustproof end cover 4221 in the radial direction of the optical axis 41. The bottom of the second clearance annular groove 4211 is spaced apart from the dustproof end cover 4221.

[0082] During long-term load operation and frequent posture switching, the robot wrist joint will produce slight elastic deformation of the components. At the same time, vibration and temperature changes will also cause slight radial displacement of the second inner ring 421 of the second bearing 42. Without a clearance structure, the dust cover 4221 can easily cause frictional interference with the second inner ring 421.

[0083] In this embodiment, the radial clearance space is further expanded by the second clearance ring groove 4211 on the second inner ring 421. Even if the second inner ring 421 of the second bearing 42 experiences slight displacement or deformation, the contact or scraping between the dustproof end cover 4221 and the second inner ring 421 of the second bearing 42 can be completely avoided. On the one hand, the dustproof end cover 4221 and the body of the second bearing 42 are protected from damage. On the other hand, the increased frictional resistance is avoided from affecting the rotational accuracy, allowing the second bearing 42 to maintain a stable and low-resistance operating state for a long time. Furthermore, although the groove wall of the second clearance ring groove 4211 and the dustproof end cover 4221 are spaced apart in the axial direction, their projections in the axial direction overlap, which can further improve the dustproof and impurity-proof effect and ensure the service life of the parts.

[0084] Specifically, in one embodiment of the present invention, the limiting member 44 and the dustproof end cap 4221 are spaced apart axially on the optical axis 41.

[0085] In this embodiment, the limiting member 44 and the dustproof end cap 4221 on the second outer ring 422 of the second bearing 42 are separated from each other in the axial direction of the optical axis 41, and the two do not make any contact. Because the equipment will continuously vibrate during operation, coupled with the temperature change of the working environment, the metal parts will experience thermal expansion and contraction. If the limiting member 44 and the dustproof end cap 4221 are axially tightly attached, the vibration impact and dimensional changes will cause the two parts to squeeze and collide with each other, which will not only easily cause local deformation and surface damage of the parts, but also produce obvious abnormal operating noise, affecting the user experience and structural life. Therefore, on the one hand, the axial clearance can effectively release the dimensional changes caused by vibration stress and thermal expansion and contraction, and eliminate the squeezing and collision problems between the limiting part 44 and the dustproof end cover 4221. This not only ensures that the original function of the axial limiting structure is not affected, but also reduces the wear and tear of parts, reduces operating noise, and further improves the quietness and durability of the entire assembly. On the other hand, it can prevent the dustproof end cover 4221 and the limiting part 44 from contacting each other in the axial direction and generating friction, thereby ensuring the smooth relative rotation between the frame beam 43 and the limiting part 44.

[0086] Specifically, in one embodiment of the present invention, please refer to... Figure 10 The frame beam 43 has a mounting groove 431 and a clearance hole 432. The clearance hole 432 is provided to pass through the bottom of the mounting groove 431 along the axial direction of the optical axis 41. The second bearing 42 is provided in the mounting groove 431, and the second outer ring 422 abuts against the bottom wall and side wall of the mounting groove 431. The optical axis 41 is provided to pass through the clearance hole 432 and is spaced apart from the hole wall of the clearance hole 432 in the radial direction.

[0087] In this embodiment, the mounting groove 431 forms a semi-enclosed positioning constraint on the second bearing 42, which can firmly fix the position of the second outer ring 422 of the second bearing 42, effectively preventing the second bearing 42 from radially offset, circumferentially rotated, or loosening and shifting during the rotation of the frame beam 43 and the bearing of load, making the installation position of the second bearing 42 more stable and reliable; the clearance hole 432 only serves as a passage for the optical axis 41, and the radial clearance can completely isolate the optical axis 41 from the frame beam 43, avoiding frictional interference between the optical axis 41 and the frame beam 43 when the optical axis 41 swings or shifts slightly.

[0088] Specifically, in one embodiment of the present invention, please refer to... Figure 10 The universal joint 4 includes two second bearings 42 and two limiting members 44; the second inner rings 421 of the two second bearings 42 are respectively sleeved on the outer peripheral walls of both ends of the optical shaft 41; the frame beam 43 connects the two second outer rings 422; the two limiting members 44 are respectively connected to the two end faces of the optical shaft 41 in the axial direction, and respectively abut against a second inner ring 421 in the axial direction of the optical shaft 41.

[0089] In this embodiment, compared to a single-end support structure, the dual second bearings 42 symmetrically arranged at both ends can jointly support the frame beam 43 and the subsequent hand connector from both sides of the optical axis 41. The force distribution is more balanced, significantly improving the overall rigidity and load-bearing capacity of the entire structure. It can withstand larger workloads at the robot end effector and is suitable for high-load, high-frequency operation scenarios. The limiting members 44 set at both ends form a bidirectional axial limiting structure, which simultaneously constrains the axial displacement of the second inner ring 421 of the second bearing 42 from both ends of the optical axis 41, sealing the axial fit gap in both directions. Compared to single-end limiting, the anti-movement effect is more thorough, effectively preventing axial wobbling at both ends of the optical axis 41, ensuring accurate positioning and better consistency of the frame beam 43 and hand connector during rotation.

[0090] Specifically, in one embodiment of the present invention, the end of the optical axis 41 has a chamfer; in the direction from the middle of the optical axis 41 to the end, the diameter of the optical axis 41 gradually decreases at the chamfer.

[0091] In this embodiment, during the assembly stage, the optical shaft 41 needs to be sequentially inserted into multiple hole-type mating structures, such as the second inner ring 421 of the second bearing 42 and the clearance hole 432 of the frame beam 43 (or the second bearing 42 is assembled onto the optical shaft 41). The sharp edges at the end of the optical shaft 41 can easily scratch the precision mating surfaces of the raceway and hole wall inside the second bearing 42, and also increase the difficulty of alignment and insertion. The clearance chamfer at the end can play a good guiding role, allowing the optical shaft 41 to be easily and quickly aligned and inserted into each mating hole, greatly reducing the assembly difficulty and improving the assembly efficiency; at the same time, the chamfer removes the burrs and sharp edges generated during the machining of the shaft end, which can not only avoid scratching the operator, but also prevent the shaft end sharp edges from scratching the second bearing 42, hole wall and other precision parts, thus completing the protection of the mating structure during the assembly stage and ensuring the mating accuracy of each moving pair.

[0092] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The optical axis 41 has a positioning groove 412, and the support base 45 has a positioning protrusion 4531. The positioning protrusion 4531 abuts against the side wall of the positioning groove 412 in the axial direction of the optical axis 41.

[0093] In this embodiment, the traditional single optical axis 41, which relies entirely on the assembly gap for positioning, is abandoned. Instead, a matching structure is formed by machining a positioning groove 412 on the optical axis 41 body and setting a positioning protrusion 4531 at the corresponding position on the support base 45. This allows the positioning protrusion 4531 to tightly abut against the axial sidewall of the positioning groove 412, thus rigidly constraining the axial displacement of the optical axis 41 from the structural root. This not only fully retains the core advantages of the traditional single optical axis 41 structure, such as small size, simple assembly, low manufacturing cost, and high space utilization, but also completely solves the problem of axial movement of the optical axis 41 and hand wobbling at the end of the optical axis caused by the continuous amplification of the assembly gap under dynamic working conditions such as high-frequency reciprocating rotation, attitude fine adjustment, and end load fluctuation.

[0094] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The positioning protrusion 4531 has a guide portion 4532; the guide portion 4532 is located at the top of the positioning protrusion 4531.

[0095] This embodiment adds a dedicated guide structure at the top of the positioning protrusion 4531, mainly to optimize the assembly design for the difficult alignment and easy damage of the optical axis 41 and the support base 45. In the overall assembly of the robot wrist joint, the core assembly steps are the insertion of the optical axis 41 and the alignment and cooperation of the positioning protrusion 4531 and the positioning groove 412. The traditional positioning protrusion 4531 without a guide structure is prone to hard collision and jamming between the edge of the protrusion and the groove of the positioning groove 412 due to slight alignment deviations or installation angle deviations during manual assembly or automated equipment assembly. This not only results in low assembly efficiency, but also easily causes the corners of the positioning protrusion 4531 and the positioning groove 412 to be chipped and deformed, directly affecting the subsequent limiting accuracy. This structure, through the guiding function of the top guide part 4532, can adapt to minor alignment errors during the assembly process, smoothly guide the positioning protrusion 4531 into the positioning groove 412, greatly reducing the assembly difficulty and improving the overall assembly efficiency; at the same time, it effectively avoids structural damage caused by hard impacts during the assembly process, protects the integrity and accuracy of the positioning mating surfaces, and ensures the product yield and subsequent use stability from the assembly stage.

[0096] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The guide section 4532 is a guide slope.

[0097] In this embodiment, the guide section 4532 is specifically optimized into a guide ramp structure, which is a refined implementation design of the aforementioned guide structure. Compared with other structures such as stepped guides and arc guides, the guide ramp is a continuous and smooth transition structure without sharp corners or dead angles. In the actual assembly process, whether it is manual installation or automated assembly line assembly, it can achieve smooth introduction. Even if there are slight positional offsets or angular deviations, it can automatically correct itself and complete precise fit, adapting to various assembly scenarios.

[0098] Specifically, in one embodiment of the present invention, the positioning groove 412 is a circular groove, and the positioning protrusion 4531 is a columnar protrusion.

[0099] In this embodiment, the positioning groove 412 is designed as a circular groove structure, paired with a columnar positioning protrusion 4531, ensuring a perfect fit between the two shapes. During the daily operation of the robot wrist joint, the optical axis 41 needs to frequently rotate and fine-tune its posture, while continuously bearing combined radial and axial loads. Traditional irregularly shaped mating structures are prone to problems such as localized single-point stress and stress concentration, which can lead to deformation and accelerated wear of the mating surfaces over long-term operation. The mating form of the circular groove and columnar protrusion, however, achieves uniform circumferential contact and even axial limiting force distribution, eliminating localized stress concentration and significantly improving the structure's load-bearing capacity and structural rigidity.

[0100] Specifically, in one embodiment of the present invention, please refer to... Figure 11The top of the positioning protrusion 4531 is spaced apart from the bottom of the positioning groove 412.

[0101] This embodiment optimizes the mating dimensions of the positioning protrusion 4531, ensuring a certain gap between the top of the protrusion 4531 and the bottom of the positioning groove 412, preventing direct contact. Precise engagement and positioning are achieved solely through the axial sidewall of the positioning groove 412. During long-term operation, rotation of the optical axis 41, end-load impact, and minor structural deformation can cause dynamic compression of the positioning structure. If the protrusion top and groove bottom are tightly fitted, continuous friction, compression, and scraping can occur, easily leading to wear and deformation of both the groove bottom and the protrusion top. Over time, this can result in loosening of the positioning mechanism and failure of the fit. This spacer structure completely avoids this defect, bearing the axial limiting force solely through the sidewall throughout the entire process, with no contact or friction at the top, significantly reducing wear and tear on the positioning structure and extending the service life of the core positioning structure.

[0102] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The support base 45 includes a support frame 451, a limiting sleeve 452, and a positioning pin 453. The limiting sleeve 452 is connected to the support frame 451 and is sleeved on the optical axis 41. The limiting sleeve 452 covers the positioning groove 412. The positioning pin 453 passes through one side wall of the support frame 451 and the limiting sleeve 452 and cooperates with the positioning groove 412. The positioning pin 453 has a positioning protrusion 4531.

[0103] This embodiment adopts a modular design for the support base 45, dividing it into three independent components: a support frame 451, a limiting sleeve 452, and a positioning pin 453. During assembly, the limiting sleeve 452 is fixed on the support frame 451 and sleeved on the outside of the optical axis 41, completely covering the positioning groove 412 area of ​​the optical axis 41. The positioning pin 453 penetrates the sidewalls of the support frame 451 and the limiting sleeve 452 and extends into the positioning groove 412 to achieve a limiting fit. Traditional integrated support base 45 structures require complete replacement if local wear or deformation occurs, resulting in high maintenance costs and cumbersome disassembly and assembly. In contrast, this modular structure allows for independent processing, individual disassembly and assembly, and targeted replacement of each component. During later maintenance, only the worn positioning pin 453 or the limiting sleeve 452 needs to be replaced, eliminating the need for complete disassembly and replacement, significantly reducing equipment maintenance costs and repair difficulty. Meanwhile, the external limiting sleeve 452 can fully cover the mating area of ​​the positioning groove 412, effectively preventing external dust, oil, and processing debris from entering the mating gap, avoiding problems such as the optical axis 41 jamming, poor rotation, and accelerated wear of the mating surface caused by the accumulation of impurities, providing a stable protective environment for the core limiting structure and ensuring long-term operating accuracy.

[0104] Specifically, in one embodiment of the present invention, the limiting sleeve 452 is located at the center of the axial direction of the optical axis 41.

[0105] In this embodiment, the limiting sleeve 452 is precisely positioned at the center of the optical axis 41, ensuring that the axial limiting force acts symmetrically on the entire structure of the optical axis 41. When the robot's end effector bears a load and adjusts its posture, the two ends of the optical axis 41 will experience different degrees of force. If the limiting structure is offset to one side, it will lead to asymmetrical force on the optical axis 41, which can easily cause problems such as unilateral eccentric wear, micro-deformation of the optical axis 41, and end effector posture deviation during long-term operation, affecting operational accuracy. This centrally positioned structure allows the limiting constraint force to be evenly distributed on both sides of the optical axis 41, balancing the force state at both ends of the optical axis 41, thoroughly improving the problems of eccentric wear and uneven force, and effectively enhancing the overall structural rigidity and operational stability of the optical axis 41.

[0106] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The limiting sleeve 452 includes a first sleeve part 4521 and a second sleeve part 4522 connected to each other. The first sleeve part 4521 and the second sleeve part 4522 are orthogonally arranged. The first sleeve part 4521 is sleeved on the optical axis 41. The second sleeve part 4522 communicates with the first sleeve part 4521 and is directly opposite to the positioning groove 412. The outer wall of the second sleeve part 4522 is connected to the support frame 451. The positioning pin 453 passes through the second sleeve part 4522 and cooperates with the positioning groove 412.

[0107] This embodiment optimizes the structure of the limiting sleeve 452 by dividing it into two orthogonal and internally connected parts: a first body part 4521 and a second body part 4522. The first body part 4521 is coaxially fitted onto the outside of the optical axis 41, achieving radial wrapping and positioning of the optical axis 41. The second body part 4522 is directly opposite the positioning groove 412 of the optical axis 41 and is fixedly connected to the support frame 451. The positioning pin 453 is inserted and fitted along the internal channel of the second body part 4522. Traditional one-piece sleeve structures are prone to problems such as interference between the through-axis channel and the positioning pin 453 channel, difficulty in assembly alignment, and weak structural strength. However, this orthogonal split structure completely separates and functions the rotation channel of the optical axis 41 and the limiting channel of the positioning pin 453. The structural layout is regular and does not interfere with each other, which not only ensures unobstructed and frictionless rotation of the optical axis 41, but also provides a stable and accurate installation benchmark for the positioning pin 453, effectively improving the fitting accuracy between the positioning pin 453 and the positioning groove 412. Meanwhile, the orthogonal connection structure significantly improves the overall structural strength of the limiting sleeve 452, making it more resistant to deformation and impact, and able to stably withstand the dynamic load during equipment operation, ensuring the continuous effectiveness of the limiting function.

[0108] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The positioning pin 453 has a limiting umbrella part 4533; the limiting umbrella part 4533 is located at the end of the positioning pin 453 away from the optical axis 41 and abuts against the second body part 4522.

[0109] In this embodiment, a limiting umbrella part 4533 is added to the outer end of the positioning pin 453 away from the optical axis 41. After assembly, the limiting umbrella part 4533 fits tightly against the outer wall surface of the second body part 4522. During robot operation, there are conditions such as continuous vibration, load impact, and rapid attitude switching, which can easily cause the positioning pin 453 to loosen, move outward, or fall off inside the body. Once the positioning pin 453 is displaced, the axial limiting function will be lost directly, and the optical axis 41 will again experience movement and shaking. This structure forms a physical limit through the external limiting umbrella part 4533, firmly restricting the axial displacement of the positioning pin 453, eliminating the problem of the positioning pin 453 loosening or shifting caused by equipment vibration and load impact, ensuring that the positioning protrusion 4531 on the positioning pin 453 always maintains effective contact and cooperation with the positioning groove 412 of the optical axis 41, maintaining a stable anti-movement effect throughout the process, greatly improving the operational reliability of the overall structure, and avoiding equipment failure and accuracy failure caused by the loosening of the positioning pin 453.

[0110] Specifically, in one embodiment of the present invention, please refer to... Figure 11 The diameter of the limiting umbrella part 4533 is larger than the diameter of the sleeve hole of the second sleeve part 4522.

[0111] This embodiment, through dimensional limitation, ensures that the outer diameter of the limiting umbrella part 4533 is strictly larger than the inner diameter of the sleeve hole of the second body part 4522, forming an irreversible physical anti-loosening structure. In practical applications, conventional positioning pins 453 require additional fasteners such as springs, clips, and screws to prevent loosening, which not only increases the number of parts and assembly steps, but also makes the fasteners prone to aging, loosening, and failure after long-term use. This dimensionally optimized structure requires no additional auxiliary fasteners. Relying on the dimensional difference between the limiting umbrella part 4533 and the sleeve hole, it structurally eliminates the possibility of the positioning pin 453 slipping inward and falling off. The anti-loosening and anti-detachment effect is stable, greatly simplifying the overall assembly process, reducing the types of parts, lowering production and maintenance costs, and avoiding equipment failures caused by the failure of auxiliary fasteners, further improving the stability and durability of the wrist joint structure.

[0112] The present invention also proposes a robot, which includes a wrist module 1000. The specific structure of the wrist module 1000 is as described in the above embodiments. Since the robot adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0113] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A wrist module, characterized in that, include: The bracket includes a connecting part, two first cantilever arms, two second cantilever arms, and a base. The two first cantilever arms are disposed on opposite sides of the bracket, and the two second cantilever arms are disposed on opposite sides of the bracket. The first cantilever arms and the second cantilever arms are respectively connected to the connecting part and the base, and each first cantilever arm and each second cantilever arm are spaced apart. Universal assembly, which is rotatably connected to the bracket; A first speed reducer, the first speed reducer having a first end cover and a second end cover; The second reducer has a third end cap and a fourth end cap, the third end cap being located at the end of the second reducer facing the first reducer and close to the second end cap; The first reducer and the second reducer drive the universal assembly to rotate, and the bracket, the second end cap and the third end cap are integrally formed.

2. The wrist module as described in claim 1, characterized in that, The first cantilever has a first plane facing the second cantilever, the second cantilever has a second plane facing the first cantilever, and the distance between the first plane and the second plane is 6 mm to 8 mm.

3. The wrist module as described in claim 2, characterized in that, Along a direction perpendicular to the first plane, the width of the first cantilever is 3.9 mm to 4.5 mm; Along a direction perpendicular to the second plane, the width of the second cantilever is 3.9 mm to 4.5 mm.

4. The wrist module as described in claim 1, characterized in that, The universal joint includes a universal joint and two transmission components. The middle part of the universal joint is rotatably connected to the bracket. The opposite ends of the universal joint are respectively rotatably connected to one of the transmission components. The opposite ends of each transmission component are respectively rotatably connected to the universal joint and the bracket. The first reducer is driven by one of the transmission components, and the second reducer is driven by the other transmission component.

5. The wrist module as described in claim 4, characterized in that, The transmission assembly includes: A transmission component having a first mounting arm and a second mounting arm spaced apart, wherein one end of the transmission component away from the first mounting arm and the second mounting arm is connected to the first reducer or the second reducer; A connector that passes through the first mounting arm and connects to the second mounting arm; A first bearing, having a first inner ring and a first outer ring, rotatably connected, the first inner ring being sleeved on the connecting member and positioned between the first mounting arm and the second mounting arm; and A rotating component is connected to the first outer ring, and the end of the rotating component away from the transmission component is connected to the universal joint.

6. The wrist module as described in claim 4, characterized in that, The universal joint includes: Optical axis; The second bearing has a second inner ring and a second outer ring, which are rotatably connected. The second inner ring is sleeved on the outer peripheral wall of one end of the optical axis. Frame beam, the frame beam connecting to the second outer ring; and A limiting member is provided, which connects to the axial end face of the optical axis and abuts against the second inner ring in the axial direction of the optical axis.

7. The wrist module as described in claim 6, characterized in that, The limiting component includes an insertion section and a limiting section; The insertion segment is connected to the optical axis; The diameter of the limiting segment is larger than that of the insertion segment, the limiting segment is connected to the insertion segment, and abuts against the second inner ring; A limiting hole is formed on the end face of the optical axis; The insertion section is located inside the limiting hole and is connected to the wall of the limiting hole; The limiting segment is located outside the limiting hole.

8. The wrist module as described in claim 6, characterized in that, The optical axis is formed with a positioning groove; The bracket is provided with a support base, and the support base has a positioning protrusion. The positioning protrusion abuts against the groove wall of the positioning groove along the axial direction of the optical axis.

9. The wrist module as described in claim 8, characterized in that, The support base includes a support frame, a limiting sleeve, and a positioning pin; The support is mounted on the bracket; The limiting sleeve is connected to the support frame and is sleeved on the optical axis, and the limiting sleeve covers the positioning groove; The positioning pin passes through one side wall of the support frame and the limiting sleeve, and cooperates with the positioning groove. The positioning pin has the positioning protrusion.

10. A robot, characterized in that, Including the wrist module as described in any one of claims 1 to 9.

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