Joint module and robot

Abstract

The invention discloses a joint module and a robot. The problem that an existing joint module cannot be rapidly and reliably switched between a pure rigid transmission mode and a flexible buffering mode is solved. The joint module comprises an output mechanism, a transmission mechanism and a power mechanism. The output mechanism is provided with a rotating shaft, an annular plate, a bolt, an electromagnetic driving assembly, an output flange and a torsion spring; the bolt is driven to axially move by controlling the power on and off of the electromagnet, so that the bolt is jointed with or separated from the output flange pin hole: when the bolt is inserted, direct mechanical rigid connection is formed, high-precision output is ensured, and continuous energy consumption is not needed; when the bolt is separated, torque is transmitted through the torsion spring, and flexible buffering is provided; rapid and active switching of the two modes is achieved, the structure is compact, control is easy, the impact resistance and terrain adaptability of the robot joint are improved, meanwhile, the high-rigidity operation precision is guaranteed, and the comprehensive performance of the robot in the complex environment is remarkably improved.

Description

Technical Field

[0001] This invention relates to the technical field of robotic arm joints in the execution of operations, and more particularly to a joint module and a robot. Background Technology

[0002] With the deepening application of robotics technology in industries, services, and special operations, joint modules, as core components for achieving precise movement and force interaction in robots, directly affect the overall capabilities of robots. Traditional joint modules typically employ a transmission method that directly and rigidly connects motors, reducers, and output components. While this method can achieve high-precision and high-rigidity position control, it lacks the necessary compliance and buffering capacity when dynamically interacting with unknown environments, bearing impact loads, or adapting to complex terrains. This can easily lead to equipment damage, motion instability, or dangerous interactions. Therefore, in the design of robot joints, how to balance high-precision rigid transmission with impact-resistant flexible adaptation has become a key issue in improving their reliability, safety, and environmental adaptability.

[0003] Some existing solutions achieve overload protection by introducing elastic elements or flexible links, such as using elastic connectors to deform when the load exceeds a threshold to buffer the impact, as in Chinese patent CN119610201A. However, their function is limited to passive protection and cannot actively adjust the output stiffness of the joint, nor can they quickly switch between rigid and flexible modes. Other solutions aim to achieve continuous adjustment of joint stiffness, such as using flexible elements with nonlinear deformation characteristics, as in Chinese patent CN114800602B, or using smart materials such as magnetorheological fluids to adjust transmission damping in real time, as in Chinese patent CN119036508B. Although these solutions can simulate the variable stiffness characteristics of biological joints to a certain extent, their output stiffness always depends on the deformation of the material or the continuous action of the external magnetic field. They cannot achieve a completely locked rigid transmission state, and they need to continuously consume energy to maintain high stiffness. The reliability of the system is affected by factors such as material fatigue and control response.

[0004] In summary, existing solutions either only have a single rigid or overload protection function, or although they can continuously adjust stiffness, they lack pure and stable rigid output capability, and generally suffer from problems such as high energy consumption, complex structure, and reliance on continuous active control. Therefore, there is an urgent need for a joint module that is compact in structure, simple to control, and can reliably switch between two modes: fully rigid transmission and flexible buffering, so as to dynamically adapt to the dual requirements of high-precision positioning and shock resistance compliance for different tasks and working conditions of the robot. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the existing technology, the purpose of this invention is to solve the technical problem that joint modules are difficult to achieve stiff-flexible switching, and to provide a joint module and robot that can achieve simple and reliable stiff-flexible switching of joint modules.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A joint module, including an output mechanism;

[0008] The output mechanism includes a rotating shaft, a ring plate, a pin, a drive component, an output flange, and a torsion elastic connection element;

[0009] The two ends of the rotating shaft are the input end and the output end, respectively. The ring plate is fixedly fitted on the rotating shaft. The pin passes through the ring plate along the axial direction of the rotating shaft and can move axially. The driving component is fixedly arranged and used to drive the pin to move axially. The output flange is located on the side of the ring plate away from the input end, and the output flange has a pin hole adapted to the pin. The torsional elastic connecting element is connected between the output flange and the ring plate or the output end, and is configured to transmit torque about the axis of the rotating shaft through its own elastic deformation.

[0010] When the pin is inserted into the pin hole, the rotating shaft is rigidly connected to the output flange through the pin; when the pin is disengaged from the pin hole, the rotating shaft is flexibly connected to the output flange through a torsional elastic connecting element.

[0011] Furthermore, the torsional elastic connecting element is a torsion spring, and the axial direction of the torsion spring corresponds to the axial direction of the rotation shaft.

[0012] Furthermore, the driving component includes an electromagnet, a magnetic chuck, a first compression spring, and a second compression spring; the electromagnet is located on the side of the ring plate near the input end and is fixedly arranged, the magnetic chuck is axially movable between the ring plate and the electromagnet, and the end of the pin away from the output flange is fixedly connected to the magnetic chuck; the first compression spring is compressed and abuts against the ring plate and the magnetic chuck, and the second compression spring is compressed and abuts against the magnetic chuck and the electromagnet;

[0013] When the electromagnet is de-energized, the magnetic plate approaches the ring plate under the force of the second compression spring, causing the pin to insert into the pin hole; when the electromagnet is energized, the magnetic plate moves away from the ring plate under the force of the first compression spring and the magnetic force of the electromagnet, causing the pin to disengage from the pin hole.

[0014] Furthermore, the magnetic chuck includes an axially distributed first push plate and a second push plate, at least one of which is made of magnetic material; the first push plate is close to the ring plate, and the end of the pin away from the output flange is fixedly connected to the first push plate, and a first compression spring is compressed and abutted between the ring plate and the first push plate; the second push plate is close to the electromagnet, and a second compression spring is compressed and abutted between the second push plate and the electromagnet; the driving component also includes a thrust ball bearing, which is axially slidably mounted on the rotating shaft and abuts between the first push plate and the second push plate.

[0015] Furthermore, the output flange is coaxial with the rotating shaft, the magnetic suction plate is annular and coaxially sleeved on the rotating shaft, and there are multiple pins and torsion elastic connecting elements, which are evenly distributed circumferentially.

[0016] Furthermore, the output mechanism also includes a cylindrical first housing, a rotating shaft coaxially arranged inside the first housing, a ring plate with a diameter smaller than the inner diameter of the first housing, an electromagnet fixedly installed inside the first housing, a magnetic suction plate with an outer diameter smaller than the inner diameter of the first housing, and an output flange coaxially arranged inside the first housing.

[0017] Furthermore, the joint module also includes a transmission mechanism, which includes a second housing, an internal gear ring, a planetary carrier, planetary gears, and a sun gear. The second housing is cylindrical and connected to the end of the first housing away from the output flange. The internal gear ring is coaxially fixed inside the second housing. The planetary carrier is coaxially rotatably disposed inside the second housing. The side of the planetary carrier facing the output mechanism has a protrusion forming an output shaft. The output shaft extends into the first housing and serves as the rotation axis. There are multiple planetary gears distributed circumferentially on the planetary carrier. The planetary gears are rotatably connected to the planetary carrier and mesh with the internal gear ring. The sun gear is located between and meshes with the planetary gears. The side of the sun gear away from the output mechanism has a protrusion forming an input shaft. The input shaft rotatably extends out of the planetary carrier for power input.

[0018] Furthermore, the joint module also includes a power mechanism located in the second housing, comprising a power disk, a rotor, and a stator; the power disk is located on the side of the planetary carrier away from the output mechanism, and is coaxial with and synchronously rotates with the input shaft; the rotor is located on the side of the power disk close to the planetary carrier, and is annular and coaxial with the power disk, and is synchronously rotated with the power disk; the second housing has an axially extending mounting portion formed inside, the mounting portion is annular and located inside the rotor, the stator is annular and fixedly fitted onto the mounting portion, the stator and rotor have a radial distance, and the stator is provided with windings.

[0019] Furthermore, the joint module also includes a detection mechanism located within the second housing, comprising a mandrel, a slip ring, a first magnetic ring, a second magnetic ring, a first encoder, and a second encoder. The mandrel is coaxial with the planetary carrier, with one end of the mandrel synchronously rotatably connected to the planetary carrier and the other end movably passing through the sun gear and the power disk. The slip ring is located on the side of the power disk away from the planetary carrier and is synchronously rotated and sleeved on the mandrel. The first magnetic ring is coaxially fixed on the side of the power disk away from the planetary carrier, and the second magnetic ring is located inside the first magnetic ring and is synchronously rotated and sleeved on the mandrel. The first encoder is located on the side of the first magnetic ring away from the power disk and is fixedly arranged and axially aligned with the first magnetic ring. The second encoder is located on the side of the second magnetic ring away from the power disk and is fixedly arranged and axially aligned with the second magnetic ring.

[0020] The present invention also includes a robot comprising the joint modules described above.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The joint module described in this invention achieves rapid and reliable mechanical switching between rigid and flexible output modes and zero-power rigidity maintenance. That is, by mechanically engaging and disengaging the pin and the output flange pin hole, the problem of the joint being difficult to switch between the two states of pure rigid transmission and effective flexible buffering is fundamentally solved. When the pin is inserted, a direct rigid connection is formed, ensuring high-precision and high-load output. Moreover, this state is maintained by the mechanical structure and spring force, without the need for continuous power supply, thus achieving zero-power rigidity maintenance, which is superior to existing variable stiffness solutions that rely on continuous power supply or material deformation.

[0023] 2. The joint module described in this invention features a rapid switching mechanism, simple control, and reliable operation. It employs a "magnet + double spring" drive scheme, which allows for rapid control of the pin's movement by switching the electromagnetic power on and off, achieving millisecond-level mode switching. The spring force serves both as a reset power source and ensures the pin's self-locking position under extreme power failure conditions (default rigid mode), enhancing the system's safety redundancy. The entire drive assembly is fixedly installed without complex rotating interfaces, significantly improving reliability and lifespan.

[0024] 3. The joint module described in this invention has a highly integrated and compact structure, combining high torque density and good environmental adaptability. Specifically, by integrating the planetary reduction mechanism, frameless motor, and rigid-flexible switching output mechanism, the transmission chain is greatly shortened, resulting in a small axial dimension and high torque density for the joint module. This compact structure is particularly suitable for the integration of multi-joint robots. At the same time, the reliable rigid mode ensures motion accuracy, while the flexible mode provides excellent impact resistance and terrain adaptability, enabling the robot to dynamically cope with complex and unstructured task scenarios. Attached Figure Description

[0025] To make the purpose, technical solution, and advantages of the invention clearer, the invention will now be described in further detail with reference to the accompanying drawings:

[0026] Figure 1 This is a perspective view of the joint module described in the embodiment;

[0027] Figure 2 This is a radial section view of the joint module described in the embodiment;

[0028] Figure 3 This is a perspective view of the output mechanism and planetary carrier described in the embodiment (the first housing is hidden).

[0029] Figure 4 The transmission mechanism and power mechanism described in the embodiment;

[0030] The components include: 1. Rotating shaft; 2. Ring plate; 3. Pin; 4. Drive component; 5. Output flange; 6. Torsional elastic connecting element; 7. Pin hole; 8. Electromagnet; 9. Magnetic suction plate; 10. First compression spring; 11. Second compression spring; 12. First push plate; 13. Second push plate; 14. Thrust ball bearing; 15. Torsional spring; 16. Positioning pin; 17. First housing; 18. Ring groove; 19. Left end cover; 20. Second housing; 21. Internal gear ring; 22. Bearing carrier; 23. Planetary carrier; 24. Planetary gear; 25. Sun gear; 26. Output shaft; 27. Input shaft. 7. Power disc 28. Rotor 29. Stator 30. Mounting part 31. Left housing 33. Right housing 34. Connecting part 35. First abutting part 36. Second abutting part 37. Support part 38. First bearing 39. First connecting part 40. Second bearing 41. Spindle 42. Slip ring 43. First magnetic ring 44. Second magnetic ring 45. First encoder 46. Second encoder 47. Groove 48. Second connecting part 49. Third bearing 50. Connecting protrusion 51. Circuit board 52. Right end cover 53. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention 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 the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Example:

[0035] Because existing joint modules only have a single rigid or overload protection function, or although they can continuously adjust stiffness, they lack pure and stable rigid output capability, and generally suffer from problems such as high energy consumption, complex structure, and reliance on continuous active control; therefore, this invention proposes a joint module with a compact structure, simple control, and reliable switching between two modes of fully rigid transmission and flexible buffering, so as to dynamically adapt to the dual requirements of high-precision positioning and shock resistance compliance for different tasks and working conditions of the robot.

[0036] A joint module, including an output mechanism;

[0037] See Figure 1 , Figure 2 and Figure 3 The output mechanism includes a rotating shaft 1, a ring plate 2, a pin 3, a driving component 4, an output flange 5, and a torsional elastic connecting element 6;

[0038] The two ends of the rotating shaft 1 are the input end and the output end, respectively. The ring plate 2 is fixedly mounted on the rotating shaft 1. The pin 3 passes through the ring plate 2 along the axial direction of the rotating shaft 1 and can move axially. The driving component 4 is fixedly arranged and used to drive the pin 3 to move axially. The output flange 5 is located on the side of the ring plate 2 away from the input end. The output flange 5 has a pin hole 7 that is adapted to the pin 3. The torsional elastic connecting element 6 is connected between the output flange 5 and the ring plate 2 or the output end, and is configured to transmit torque about the axis of the rotating shaft 1 through its own elastic deformation.

[0039] When the pin 3 is inserted into the pin hole 7, the rotating shaft 1 is rigidly connected to the output flange 5 through the pin 3; when the pin 3 is disengaged from the pin hole 7, the rotating shaft 1 is flexibly connected to the output flange 5 through the torsional elastic connecting element 6.

[0040] The joint module of this invention outputs rotational power through an output mechanism. In the output mechanism, a rotating shaft 1 receives the rotational power and drives the ring plate 2 to rotate. By setting an axially movable pin 3 and a torsional elastic connecting element 6 between the rotating shaft 1 and the output flange 5, a binary output mode switching based on mechanical engagement / disengagement is achieved. Under the driving action of the driving component 4, when the pin 3 is inserted into the pin hole 7, the ring plate 2 and the output flange 5 achieve a rigid transmission connection in the circumferential direction through the pin 3. The rotating shaft 1 achieves rigid output through the ring plate 2, the pin 3, and the output flange 5, ensuring high-precision, high-load force transmission. When the pin 3 disengages from the pin hole 7, the ring plate 2 and... The output flange 5 achieves flexible transmission connection in the circumferential direction through the torsional elastic connecting element 6. The rotating shaft 1 achieves flexible output through the ring plate 2, the pin 3 and the output flange 5. That is, when the circumferential torque brought by the next-stage joint or actuator connected to the output flange 5 is greater than the minimum force for the torsional elastic connecting element 6 to undergo torsional elastic deformation, the torsional elastic connecting element 6 will be forced to undergo torsional elastic deformation, causing the output flange 5 and the rotating shaft 1 to rotate relative to each other at a certain angle, so that the joint has passive compliance and buffering capability. This structure solves the technical problem that existing joints cannot quickly and reliably switch between the two states of pure rigid transmission and effective flexible buffering, and the overall structure is simple and the operation is reliable.

[0041] Understandably, the axial, circumferential, and radial directions are all based on the description of the rotating shaft 1; in practice, one or more of the pin 3 and the torsionally elastic connecting element 6 may be used.

[0042] Understandably, the joint module must also include a power mechanism and a transmission mechanism. The power mechanism is used to provide rotational power, and the transmission mechanism is connected between the power mechanism and the output mechanism to reduce speed and increase torque. The entire joint module is finally connected to the next-level joint or actuator through the output flange 5 to realize power output.

[0043] Understandably, when the output flange 5 and the rotating shaft 1 are rotating relative to each other or tend to rotate relative to each other, it is difficult for the pin 3 to move axially into or out of the pin hole 7. Therefore, the switching between rigid and flexible operation by driving the pin 3 to move axially through the drive component 4 should be carried out when the next-level joint or actuator connected to the output flange 5 is in a non-impact or low-load condition. The timing of the switch can be determined by the operator or the robot-based sensors based on the operating conditions. For example, when the joint module is used to drive the walking wheels of the robot's feet, the timing of the switch can be determined according to the condition of the road surface. For example, when the robot is about to move from a flat road surface to an uneven road surface, the switch should be made to flexible output to reduce the impact of the road surface on the internal structure of the joint module.

[0044] Understandably, the output flange 5 is used for rotating power output. In practice, it can be set coaxially with the rotating shaft 1 or eccentrically with the rotating shaft 1 according to actual needs. In addition, in the above structure, the output flange 5 lacks circumferential constraint. When there is only one pin 3, the pin 3 should be polygonal to avoid relative rotation between the pin 3 and the output flange 5, and to ensure the reliability of power transmission to the output flange 5 through the pin 3.

[0045] In implementation, the rotating shaft 1 can be set independently of the transmission mechanism or directly provided by the transmission structure; the driving component 4 is used to provide power for the axial movement of the pin 3. In implementation, the driving component 4 can be a cylinder, a hydraulic cylinder, or an electric actuator. If the driving component 4 is a cylinder, a hydraulic cylinder, or an electric actuator, since the rod of the cylinder, hydraulic cylinder, or electric actuator needs to be axially connected to the pin 3 to drive the pin 3 to move axially, based on the above structure, a pneumatic rotary joint, a hydraulic rotary joint, or an electric conductive slide needs to be arranged on the outside of the rotating shaft 1 to ensure that the cylinder, hydraulic cylinder, and electric actuator can operate normally in the rotating state.

[0046] Please see Figure 2 and Figure 3 The driving component 4 includes an electromagnet 8, a magnetic chuck 9, a first compression spring 10, and a second compression spring 11. The electromagnet 8 is located on the side of the ring plate 2 near the input end and is fixedly arranged. The magnetic chuck 9 is axially movable between the ring plate 2 and the electromagnet 8. The end of the pin 3 away from the output flange 5 is fixedly connected to the magnetic chuck 9. The first compression spring 10 is compressed and abuts against the ring plate 2 and the magnetic chuck 9, and the second compression spring 11 is compressed and abuts against the magnetic chuck 9 and the electromagnet 8. When the electromagnet 8 is de-energized, the magnetic chuck 9 moves closer to the ring plate 2 under the spring force of the second compression spring 11, causing the pin 3 to insert into the pin hole 7. When the electromagnet 8 is energized, the magnetic chuck 9 moves away from the ring plate 2 under the spring force of the first compression spring 10 and the magnetic force of the electromagnet 8, causing the pin 3 to disengage from the pin hole 7.

[0047] Thus, the driving component 4 adopts a specific structure consisting of an electromagnet 8, a magnetic suction plate 9, and first and second compression springs 11, realizing stable and rapid electronically controlled driving of the pin 3. The electromagnet 8 is fixedly installed and does not need to rotate with the rotating shaft 1, simplifying the structure. This design allows the pin 3 to automatically insert into the pin hole 7 under the action of the second compression spring 11 and maintain a rigid connection when the electromagnet 8 is de-energized, achieving zero power consumption in the rigid mode and effectively overcoming the defect of continuous energy consumption required to maintain high rigidity in the prior art. When the electromagnet 8 is energized, the pin 3 overcomes the spring force and disengages from the pin hole 7, switching to the flexible mode. This design takes into account switching speed, reliability, and energy efficiency.

[0048] Please see Figure 2 and Figure 3 The magnetic plate 9 includes a first push plate 12 and a second push plate 13 distributed axially, at least one of the first push plate 12 and the second push plate 13 is made of magnetic material; the first push plate 12 is close to the ring plate 2, the end of the pin 3 away from the output flange 5 is fixedly connected to the first push plate 12, and the first compression spring 10 is compressed and abutted between the ring plate 2 and the first push plate 12; the second push plate 13 is close to the electromagnet 8, and the second compression spring 11 is compressed and abutted between the second push plate 13 and the electromagnet 8; the driving component 4 also includes a thrust ball bearing 14, which is axially slidably mounted on the rotating shaft 1 and abuts between the first push plate 12 and the second push plate 13;

[0049] In this way, the magnetic suction plate 9 is subdivided into a first push plate 12 and a second push plate 13, and a thrust ball bearing 14 is set between them. This structure decouples the part of the drive component 4 that rotates with the shaft (connected to the pin 3 and the first push plate 12) from the stationary part (the second push plate 13 and the electromagnet 8). The thrust ball bearing 14 bears the axial thrust but allows relative rotation, which avoids unnecessary rotational friction of the second push plate 13, the second compression spring 11 and the electromagnet 8 with the rotating shaft 1, significantly reduces switching resistance and wear, and improves driving efficiency and mechanism durability.

[0050] In practice, the torsional elastic connecting element 6 can be a polyurethane elastic block, torsion bar, or metal diaphragm, etc. In practice, the ring plate 2 can be a structure integrally formed with the rotating shaft 1. In this embodiment, the ring plate 2 is a component independent of the rotating shaft 1. The ring plate 2 is keyed to the rotating shaft 1 so that the ring plate 2 is fixed on the rotating shaft 1.

[0051] Please see Figure 2 and Figure 3 The torsion elastic connecting element 6 is a torsion spring 15, and the axial direction of the torsion spring 15 corresponds to the axial direction of the rotating shaft 1; the output flange 5 is coaxial with the rotating shaft 1, the magnetic suction plate 9 is annular and coaxially sleeved on the rotating shaft 1, and there are multiple pins 3 and torsion springs 15, which are evenly distributed circumferentially; in this embodiment, there are three pins 3 and three torsion springs 15, which are alternately distributed circumferentially.

[0052] Thus, the torsion spring 15, as the torsion elastic connecting element 6, has the advantages of good linearity, long service life, and easy selection and replacement. It is convenient to adjust the stiffness according to different buffering requirements, which enhances the designability and performance consistency of the joint module. In addition, the output flange 5 is coaxial with the rotating shaft 1, and the pins 3, torsion springs 15 and magnetic plates 9 are all arranged in a circumferentially even ring shape. This ensures the uniformity and stability of power transmission, avoids vibration, noise and stress concentration caused by off-center load, and makes the joint run more smoothly in both modes. The arrangement of multiple pins 3 and multiple springs also provides redundancy and backup, which enhances the robustness of the system.

[0053] In this embodiment, the output flange 5 has an axial gap with the output end. The torsion spring 15 is connected between the output flange 5 and the ring plate 2. The side of the output flange 5 facing the ring plate 2 has a protruding positioning post 16. The positioning post 16 has an axial gap with the ring plate 2. There are multiple positioning posts 16 evenly distributed circumferentially. The torsion spring 15 is sleeved on the positioning post 16. The inner diameter of the torsion spring 15 is larger than the diameter of the positioning post 16. The positioning post 16 is used to prevent the torsion spring 15 from excessively deforming and to limit the maximum angle range of the output flange 5 relative to the rotating shaft 1 during flexible transmission, so as to avoid complete failure of transmission output.

[0054] Please see Figure 1 and Figure 2 The output mechanism also includes a cylindrical first housing 17, a rotating shaft 1 coaxially rotatably arranged inside the first housing 17, a ring plate 2 with a diameter smaller than the inner diameter of the first housing 17, an electromagnet 8 fixedly installed inside the first housing 17, a magnetic suction plate 9 with an outer diameter smaller than the inner diameter of the first housing 17, and an output flange 5 coaxially rotatably arranged inside the first housing 17.

[0055] In this way, by setting up a cylindrical first housing 17, an integrated installation, support and protection space is provided for core moving components such as the rotating shaft 1, the ring plate 2, the electromagnet 8, the magnetic suction plate 9 and the output flange 5. The housing ensures the coaxiality and relative position accuracy between the components, while facilitating standardized connection with other parts of the robot, thereby improving the integrity, protection level and ease of use of the joint module.

[0056] In this embodiment, the electromagnet 8 is ring-shaped and coaxially fixed inside the first housing 17, with the rotating shaft 1 moving through it. The first push plate 12 and the second push plate 13 are both ring-shaped, with an inner diameter larger than the outer diameter of the rotating shaft 1 and an outer diameter smaller than the inner diameter of the first housing 17. The first push plate 12 abuts against the ring of the thrust ball bearing 14, which is interference-fitted with the rotating shaft 1. The second push plate 13 abuts against the seat ring of the thrust ball bearing 14. 13. Magnetic material is used; an annular groove 18 adapted to the output flange 5 is opened on the inner wall of the first housing 17. The annular groove 18 extends axially to a near end face. An annular left end cover 19 is connected to the end face. The left end cover 19 forms the left side wall of the annular groove 18. The output flange 5 is located in the annular groove 18 and rotates in fit. Its axial movement is restricted by the left and right side walls of the annular groove 18, so as to reduce the impact on the actuator or the next stage joint during output, which is transmitted to the interior of the joint module through the output flange 5.

[0057] Please see Figure 1 , Figure 2 and Figure 4 The joint module further includes a transmission mechanism, which includes a second housing 20, an internal gear ring 21, a planet carrier 23, planet gears 24, and a sun gear 25. The second housing 20 is cylindrical and connected to the end of the first housing 17 away from the output flange 5. The internal gear ring 21 is coaxially fixed inside the second housing 20. The planet carrier 23 is coaxially rotatably disposed inside the second housing 20. The side of the planet carrier 23 facing the output mechanism has a protrusion forming an output shaft 26. The output shaft 26 extends into the first housing 17 and serves as the rotation shaft 1. There are multiple planet gears 24 distributed circumferentially on the planet carrier 23. The planet gears 24 are rotatably connected to the planet carrier 23 and mesh with the internal gear ring 21. The sun gear 25 is located between the planet gears 24 and meshes with them. The side of the sun gear 25 away from the output mechanism has a protrusion forming an input shaft 27. The input shaft 27 extends rotatably out of the planet carrier 23 for power input.

[0058] In this way, a planetary gear transmission mechanism is introduced, and its output shaft 26 is directly used as the rotating shaft 1. The planetary reduction mechanism has the advantages of compact structure, large transmission ratio, high load capacity and stable torque output. This integrated design achieves high torque density output and speed reduction and torque amplification in a limited space, which meets the requirements of robot joints for miniaturization, lightweight and high output performance.

[0059] Please see Figure 1 , Figure 2 and Figure 4The joint module also includes a power mechanism located in the second housing 20, comprising a power disk 28, a rotor 29, and a stator 30. The power disk 28 is located on the side of the planetary carrier 23 away from the output mechanism, and is coaxial with and synchronously rotates with the input shaft 27. The rotor 29 is located on the side of the power disk 28 closer to the planetary carrier 23, and is annular and coaxial with the power disk 28, and is synchronously rotated with the power disk 28. The second housing 20 has an axially extending mounting portion 31 formed inside, which is annular and located inside the rotor 29. The stator 30 is annular and fixedly fitted onto the mounting portion 31, with a radial distance between the stator 30 and the rotor 29. The stator 30 is provided with windings (not shown in the figure).

[0060] In this way, the power mechanism is further integrated into a frameless torque motor unit, with the stator 30 directly fixed to the second housing 20, and the rotor 29 connected to the input shaft 27 of the sun gear 25 via the power disk 28. This highly integrated direct-drive design shortens the power transmission chain, reduces the axial dimension and rotational inertia, and makes the joint module structure more compact and the dynamic response faster, making it particularly suitable for space-constrained robot joint applications.

[0061] In this embodiment, the planetary gear 24 consists of a gear shaft and gears. The gears are fitted onto the gear shaft and splined. The gears in the planetary gear 24 mesh with the sun gear 25, and the gear shaft meshes with the internal gear ring 21. The second housing 20 consists of a left housing 33 and a right housing 34 connected axially. The outer diameter of the right housing 34 is larger than the outer diameter of the first housing 17. The left housing 33 is an annular plate structure and is connected between the first housing 17 and the right housing 34. The internal gear ring 21 is coaxially fitted inside the left housing 33. A connecting portion 35 is formed on the outer periphery, abutting against the side of the left housing 33 and connected together by an axially arranged screw; a first abutting portion 36 is formed on the inner wall of the first housing 17, and a second abutting portion 37 is formed on the end face of the internal gear ring 21 facing the output mechanism; the electromagnet 8 is abutted and fixed between the first abutting portion 36 and the second abutting portion 37; a mounting portion 31 is formed on the side of the left housing 33 away from the output mechanism, and the mounting portion 31 and the planetary carrier 23 have partial axial overlap. The planetary carrier 23 is a cage-like structure. A support portion 38 protrudes from the side of the planetary carrier 23 away from the output mechanism. A first bearing 39 is provided between the support portion 38 and the mounting portion 31 to allow the planetary carrier 23 to rotate with the left housing 33. Specifically, the first bearing 39 is provided on the inner side of the support portion 38 through the bearing bracket 22. The inner diameter of the end of the planetary carrier 23 away from the output mechanism is larger than the diameter of the input shaft 27 on the sun gear 25. A first connecting portion 40 protrudes from the side of the power disk 28 facing the planetary carrier 23. The first connecting portion 40 extends into the inner hole of the end of the planetary carrier 23 away from the output mechanism. The first connecting portion 40 and the input shaft 27 are synchronously rotated through a spline connection. A second bearing 41 is provided between the first connecting portion 40 and the inner hole of the end of the planetary carrier 23 away from the output mechanism to allow the power disk 28 to rotate with the planetary carrier 23, thereby shortening the overall axial dimension of the transmission mechanism and the power mechanism and improving structural stability.

[0062] Please see Figure 2 and Figure 4The joint module further includes a detection mechanism located within the second housing 20, comprising a spindle 42, a slip ring 43, a first magnetic ring 44, a second magnetic ring 45, a first encoder 46, and a second encoder 47. The spindle 42 is coaxial with the planetary carrier 23, with one end of the spindle 42 synchronously rotatably connected to the planetary carrier 23 and the other end movably passing through the sun gear 25 and the power disk 28. The slip ring 43 is located on the side of the power disk 28 away from the planetary carrier 23 and is synchronously rotated and sleeved on the spindle 42. The first magnetic ring 44 is coaxially fixed on the side of the power disk 28 away from the planetary carrier 23, and the second magnetic ring 45 is located inside the first magnetic ring 44 and is synchronously rotated and sleeved on the spindle 42. The first encoder 46 is located on the side of the first magnetic ring 44 away from the power disk 28 and is fixedly arranged and axially aligned with the first magnetic ring 44. The second encoder 47 is located on the side of the second magnetic ring 45 away from the power disk 28 and is fixedly arranged and axially aligned with the second magnetic ring 45.

[0063] In this way, a detection mechanism including dual magnetic rings and dual encoders is set up to detect the rotational speed and position of the sun gear 25 (high-speed end) and the planetary carrier 23 (low-speed output end), respectively. By comparing the information of the two, the control system can accurately calculate the actual transmission ratio, output torque (combined with the characteristics of flexible elements) and monitor the transmission status. This provides key state perception data for realizing precise position / torque control of the joint, intelligent judgment of the timing of stiffness-flexibility switching and fault diagnosis, and supports the intelligent and adaptive operation of the joint.

[0064] In this embodiment, the slip ring 43 has a groove 48 on the side facing the power disk 28, and a second connecting portion 49 protrudes from the side of the power disk 28 away from the planetary carrier 23. The second connecting portion 49 extends into the groove 48 and has a radial distance from the sidewall of the groove 48. A third bearing 50 is provided between the inner side of the second connecting portion 49 and the opposite sidewall of the groove 48 to allow the power disk 28 and the slip ring 43 to rotate. The slip ring 43 has a connecting protrusion 51 on the side away from the power disk 28, and a radially extending insertion is provided on the connecting protrusion 51. The mandrel 42 has a corresponding slot (not shown in the figure) on the core shaft 42, and a locking pin (not shown in the figure) is provided in the core shaft 42 so that the slip ring 43 and the mandrel 42 rotate synchronously. The first encoder 46 and the second encoder 47 are arranged on the annular circuit board 52, which is sleeved on the slip ring 43 and fixedly connected to the right housing 34. The right housing 34 is connected to a circular plate-shaped right end cover 53 at the end away from the first housing 17 to close the second housing 20.

[0065] The present invention also includes a robot comprising the joint module described above. Thus, the robot using the joint module has the ability to dynamically switch between rigid and flexible characteristics according to the task and environment. It adopts a rigid mode when high-precision positioning and heavy-load operation are required, and switches to a flexible mode to absorb vibration and improve safety and adaptability when facing impact, irregular terrain or human-machine interaction. This capability enables the robot to break through the limitations of traditional fixed joint stiffness and significantly improve its overall performance, reliability and operational compliance in complex and dynamic scenarios.

[0066] To facilitate a better understanding of the present invention, the working principle of the joint module is described below:

[0067] Power transmission path: After power is applied, the stator 30 winding of the power mechanism generates a rotating magnetic field, driving the rotor 29 to rotate; the rotor 29 drives the power disk 28 fixed to it to rotate synchronously, and the power disk 28 transmits torque to the input shaft 27 of the sun gear 25 through spline connection, driving the sun gear 25 to rotate at high speed; the sun gear 25 meshes with multiple planet gears 24 evenly distributed around the circumference, driving the planet gears 24 to revolve along the internal gear ring 21 fixed to the housing while rotating on their own axis, thereby driving the planet carrier 23 to rotate with a reduced speed and increased torque; the output shaft 26 of the planet carrier 23 directly serves as the rotation shaft 1 of the output mechanism, transmitting the power after reduction and torque increase to the ring plate 2 fixed on it.

[0068] Rigid Output Mode: When high rigidity and high precision output are required, the electromagnet 8 is de-energized, the magnetic force of the electromagnet 8 disappears, and the second compression spring 11, which is always in a compressed state, releases its elastic energy, pushing the second push plate 13, the thrust ball bearing 14, and the first push plate 12 to move axially towards the ring plate 2. During this process, multiple pins 3 fixed on the first push plate 12 move together and are inserted into the corresponding pin holes 7 on the output flange 5. At this time, the ring plate 2, the pins 3, and the output flange 5 form a rigid mechanical connection with no relative movement in the circumferential direction. All the torque from the rotating shaft 1 is directly transmitted to the output flange 5 through this rigid connection, realizing zero backlash and high rigidity power output. This rigid connection state is maintained by the mechanical structure itself and the preload of the second compression spring 11, without any electrical energy input, realizing zero power consumption maintenance.

[0069] Flexible output mode: When facing impact loads, irregular terrain, or requiring compliant interaction, the electromagnet 8 is energized, generating a strong magnetic field that attracts the second push plate 13 (made of magnetic material) to move closer, compressing the second compression spring 11. As the second push plate 13 moves backward, the first push plate 12 moves along with it under the restoring force of the first compression spring 10, thereby causing all the pins 3 to completely disengage from the pin holes 7 of the output flange 5. At this time, the direct mechanical connection between the ring plate 2 and the output flange 5 is released, and the torque transmission path changes to: the ring plate 2 circumferentially drives one end of multiple circumferentially distributed torsion springs 15, causing the torsion springs 15 to undergo elastic torsional deformation, thereby driving the output flange 5 connected to its other end to rotate. Through the deformation of the torsion springs 15, the impact energy is absorbed and buffered, giving the joint passive compliance, protecting the internal transmission components and adapting to changes in external load.

[0070] Mode switching logic: The switching between rigid and flexible modes is controlled by the on / off state of electromagnet 8, which responds quickly; the mode selection can be based on preset programs, task instructions, or environmental information (such as contact force and ground flatness) perceived in real time by onboard sensors (such as force sensors and vision systems) for intelligent judgment and triggering, so that the robot joints can dynamically adapt to complex working conditions.

[0071] In summary, this invention provides a rigid-flexible switching joint module based on the mechanical pin 3-engagement / separation principle. Through the design of the output mechanism, it reliably achieves rapid and active switching between two output modes: pure rigid transmission and elastic flexible buffering, utilizing the synergistic effect of electromagnetic drive and spring reset. This solution fundamentally overcomes the inherent defects of existing variable stiffness joints, which cannot achieve complete rigid locking or require continuous energy consumption to maintain rigidity. The structure is simple and compact, and the control is simple and reliable. Robots equipped with this joint module can maintain rigid output to ensure positioning accuracy when performing high-precision tasks, and quickly switch to flexible output to absorb vibration and improve safety when encountering impacts or complex terrain. This significantly enhances the robot's comprehensive adaptability, task execution flexibility, and overall reliability in unstructured and dynamically changing environments.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A joint module, characterized in that: Including output mechanisms; The output mechanism includes a rotating shaft, a ring plate, a pin, a drive component, an output flange, and a torsion elastic connection element; The two ends of the rotating shaft are the input end and the output end, respectively. The ring plate is fixedly fitted on the rotating shaft. The pin passes through the ring plate along the axial direction of the rotating shaft and can move axially. The driving component is fixedly arranged and used to drive the pin to move axially. The output flange is located on the side of the ring plate away from the input end, and the output flange has a pin hole adapted to the pin. The torsional elastic connecting element is connected between the output flange and the ring plate or the output end, and is configured to transmit torque about the axis of the rotating shaft through its own elastic deformation. When the pin is inserted into the pin hole, the rotating shaft is rigidly connected to the output flange through the pin; when the pin is disengaged from the pin hole, the rotating shaft is flexibly connected to the output flange through a torsional elastic connecting element.

2. The joint module according to claim 1, characterized in that: The torsional elastic connecting element is a torsion spring, and the axial direction of the torsion spring corresponds to the axial direction of the rotating shaft.

3. A joint module according to claim 1, characterized in that: The driving component includes an electromagnet, a magnetic chuck, a first compression spring, and a second compression spring. The electromagnet is located on the side of the ring plate near the input end and is fixedly arranged. The magnetic chuck is axially movable between the ring plate and the electromagnet. The end of the pin away from the output flange is fixedly connected to the magnetic chuck. The first compression spring is compressed and abuts against the ring plate and the magnetic chuck, and the second compression spring is compressed and abuts against the magnetic chuck and the electromagnet. When the electromagnet is de-energized, the magnetic plate approaches the ring plate under the force of the second compression spring, causing the pin to insert into the pin hole; when the electromagnet is energized, the magnetic plate moves away from the ring plate under the force of the first compression spring and the magnetic force of the electromagnet, causing the pin to disengage from the pin hole.

4. A joint module according to claim 3, characterized in that: The magnetic chuck includes an axially distributed first push plate and a second push plate, at least one of which is made of magnetic material; the first push plate is close to the ring plate, and the end of the pin away from the output flange is fixedly connected to the first push plate, and a first compression spring is compressed and abutted between the ring plate and the first push plate; the second push plate is close to the electromagnet, and a second compression spring is compressed and abutted between the second push plate and the electromagnet; the driving component also includes a thrust ball bearing, which is axially slidably mounted on the rotating shaft and abuts between the first push plate and the second push plate.

5. A joint module according to claim 3, characterized in that: The output flange is coaxial with the rotating shaft, the magnetic chuck is ring-shaped and coaxially sleeved on the rotating shaft, and there are multiple pins and torsion elastic connecting elements, which are evenly distributed circumferentially.

6. A joint module according to claim 5, characterized in that: The output mechanism also includes a cylindrical first housing, a rotating shaft coaxially arranged inside the first housing, a ring plate with a diameter smaller than the inner diameter of the first housing, an electromagnet fixedly installed inside the first housing, a magnetic suction plate with an outer diameter smaller than the inner diameter of the first housing, and an output flange coaxially arranged inside the first housing.

7. A joint module according to claim 6, characterized in that: The joint module also includes a transmission mechanism, which comprises a second housing, an internal gear ring, a planet carrier, planet gears, and a sun gear. The second housing is cylindrical and connected to the end of the first housing away from the output flange. The internal gear ring is coaxially fixed inside the second housing. The planet carrier is coaxially rotatably disposed inside the second housing. The side of the planet carrier facing the output mechanism protrudes to form an output shaft, which extends into the first housing and serves as the rotation axis. There are multiple planet gears circumferentially distributed on the planet carrier. The planet gears are rotatably connected to the planet carrier and mesh with the internal gear ring. The sun gear is located between and meshes with the planet gears. The side of the sun gear away from the output mechanism protrudes to form an input shaft, which rotatably extends out of the planet carrier for power input.

8. A joint module according to claim 7, characterized in that: The joint module also includes a power mechanism located in the second housing, comprising a power disk, a rotor, and a stator. The power disk is located on the side of the planetary carrier away from the output mechanism, and is coaxial with and synchronously rotates with the input shaft. The rotor is located on the side of the power disk close to the planetary carrier, and is annular and coaxial with the power disk, and is synchronously rotated with the power disk. The second housing has an axially extending mounting portion formed inside, which is annular and located inside the rotor. The stator is annular and fixedly mounted on the mounting portion, with a radial distance between the stator and the rotor, and windings are provided on the stator.

9. A joint module according to claim 8, characterized in that: The joint module also includes a detection mechanism located within the second housing, comprising a mandrel, a slip ring, a first magnetic ring, a second magnetic ring, a first encoder, and a second encoder. The mandrel is coaxial with the planetary carrier, with one end of the mandrel synchronously rotatably connected to the planetary carrier and the other end movably passing through the sun gear and the power disk. The slip ring is located on the side of the power disk away from the planetary carrier and is synchronously rotated and sleeved on the mandrel. The first magnetic ring is coaxially fixed on the side of the power disk away from the planetary carrier, and the second magnetic ring is located inside the first magnetic ring and is synchronously rotated and sleeved on the mandrel. The first encoder is located on the side of the first magnetic ring away from the power disk and is fixedly arranged and axially aligned with the first magnetic ring. The second encoder is located on the side of the second magnetic ring away from the power disk and is fixedly arranged and axially aligned with the second magnetic ring.

10. A robot, characterized in that: Includes the joint module as described in any one of claims 1-9.

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