Damping dual-mode wheel-foot mechanical leg

Abstract

A damping dual-mode wheel-foot mechanical leg comprises a hip joint, a thigh unit and a shank unit, the hip joint comprises a supporting mechanism, a first transmission mechanism, a second transmission mechanism and a third transmission mechanism, the first transmission mechanism, the second transmission mechanism and the third transmission mechanism are installed on the supporting mechanism, and the thigh unit and the shank unit are driven to move in a following mode through movement of the hip joint; the double-mode switching capacity is achieved, in a wheel type working mode, a fourth steering engine drives a cylindrical gear, an intermediate gear and a gear ring, planet carrier supporting legs are folded and locked, and meanwhile a third steering engine drives tires to roll through transmission of a conveying belt; in the foot type working mode, the second steering engine is disabled, the third steering engine drives the disc connecting piece to drive the whole thigh unit to swing, leg stepping is achieved, and meanwhile the fourth steering engine controls the planet carrier shank to be unfolded to serve as a foot support; the robot can be well applied to work on rugged mountain roads, rescue sites, step road sections and the like, and has good environment adaptability and stability.

Description

Technical Field

[0001] This invention relates to the field of wheeled robot technology, specifically to a shock-absorbing dual-modal wheeled mechanical leg. Background Technology

[0002] Currently, wheeled and legged robots are developing rapidly and are widely used in common scenarios. However, wheeled robots have stability issues in complex environments, while legged robots suffer from high power consumption. Existing wheeled and legged robots mostly use servo motor linkage transmission, which has poor stability and is prone to falling and causing injury. Patent application CN112937821A discloses a wheeled and legged robot leg structure with shock absorption function. The proposed wheeled and leg structure with shock absorbers has a hydraulic shock absorber at the hip and a Mecanum wheel installed at the end of the lower leg. The extension and retraction of the lower leg is controlled by a linear push rod to achieve "wheel landing" or "leg landing". An independent shock absorber is used to absorb the impact. The proposed shock absorption mechanism is complex and non-integrated: it relies on external hydraulic shock absorbers or spring dampers, increasing weight, cost, and potential failure points, and is difficult to miniaturize, making it unsuitable for small robot platforms; mode switching depends on additional actuators (pusles); transmission and structure are separate: the lower leg is only a support rod, and the gear system is only used to drive the wheels, not integrated with the leg structure, failing to achieve functional integration, resulting in a large number of parts and a large size. Therefore, it is necessary to design a shock-absorbing dual-modal wheel-footed mechanical leg to solve the above problems. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to propose a shock-absorbing dual-modal wheeled robotic leg. Through the coordinated structure of the hip joint, thigh unit, and lower leg unit, it achieves functional reuse of wheeled rolling mode and leg walking mode, multi-level shock absorption mechanism, and planetary structure. This avoids redundant designs such as "adding switching mechanisms" and "multiple independent drive systems" common in traditional wheeled robots, significantly improving the system's integration, lightweight level, and reliability, and solving the problem of insufficient stability in existing wheeled robots.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A shock-absorbing dual-mode wheeled mechanical leg includes a hip joint, a thigh unit, and a calf unit. The hip joint includes a support mechanism and a first transmission mechanism, a second transmission mechanism, and a third transmission mechanism mounted on the support mechanism. The movement of the hip joint drives the thigh unit and the calf unit to follow the movement. The first transmission mechanism includes a first servo motor 3. The power output end of the first servo motor 3 is connected to one end of the hip shaft 9 through a disc connector 4 and a thrust bearing 5. The thrust bearing 5 is disposed on the side plate of the first support member 6. The other end of the hip shaft 9 is connected to the third flange bearing 48 on the thrust disc 8 parallel to the side plate on the first support member 6. A spring 7 is also wound on the hip shaft 9. One end of the spring 7 is connected to the spring hole 35 on the disc connector 4, and the other end of the spring 7 is in contact with the thrust disc 8. The second transmission mechanism includes a second servo motor 10 fixed to the first support member 6. The power output end of the second servo motor 10 is connected to one end of the worm gear 12 via a coupling 11. The other end of the worm gear 12 is connected to the second support member 49 via a second flange bearing 50. The worm gear 12 meshes with the worm wheel 13. One side of the worm wheel 13 is connected to the thrust plate 8 via a third flange bearing 48. The other side of the worm wheel 13 is connected to the third flange bearing 51 of the third transmission mechanism. The third transmission mechanism includes a fourth flange bearing 51 disposed at one end of the second sleeve 52, and the other end of the second sleeve 52 is connected to one side of the third support member 14 through a fifth flange bearing 53. A fourth support member 54 is disposed on the other side of the third support member 14, and a third servo motor 15 is connected between the third support member 14 and the fourth support member 54.

[0005] The thigh unit includes a thigh mounting frame 2 and a thigh shell 1 covering the thigh mounting frame 2. The thigh mounting frame 2 is equipped with a large pulley 16, a tension pulley 27, a small pulley 18, and a conveyor belt 17 connecting the three in sequence. The thigh mounting frame 2 is also provided with a fourth servo motor 26 on the side near the hip joint. The power output shaft of the fourth servo motor 26 is connected to a cylindrical gear 19 through a mounting bearing in the middle of the thigh mounting frame 2. The cylindrical gear 19 meshes with an intermediate gear 20. The intermediate gear 20 meshes with the outer ring of a gear ring 21. The inner ring of the gear ring 21 meshes with a planetary gear 23. The planetary gear 23 meshes with a sun gear 29. The output end of the sun gear 29 passes through the small pulley 18 and is connected to a tire 22.

[0006] The gear shaft of the sun gear 29 is interference-fitted with the small pulley 18.

[0007] The lower leg unit includes a planetary carrier leg 24. The end of the planetary carrier leg 24 is provided with a foot sleeve 30. The other end of the planetary carrier leg 24 is provided with a planetary gear connection hole 46 and a sun gear connection hole 47. The planetary gear connection hole 46 and the sun gear connection hole 47 are respectively connected to the planetary gear 23 and the sun gear 29 through flange bearings.

[0008] The thigh shell 1 is provided with a first connecting hole 44, a second connecting hole 43 and a third connecting hole 45 from top to bottom. The power output shaft of the fourth servo motor 26 passes through the first connecting hole 44 and is adapted to connect with the cylindrical gear 19. The axle of the intermediate gear 20 is adapted to connect with the sixth flange bearing 42, the seventh flange bearing 41 and the flange bolt 40 through the second connecting hole 43. The gear ring 21 is connected to the small pulley 18 through the first flange bearing 38 and the first sleeve 39 passing through the third connecting hole 45.

[0009] Robots or walking devices, including any of the above-mentioned shock-absorbing bimodal wheeled mechanical legs.

[0010] Compared with the prior art, the advantages of the present invention are: I. Achieve efficient switching between wheeled and legged dual modes to enhance terrain adaptability. Wheel mode: The planetary carrier legs are retracted and locked by the four-wheel drive of the servo motor, the cylindrical gear → intermediate gear → gear ring, and the sun gear is driven by the three-wheel drive of the servo motor to drive the tires to roll, so as to achieve high speed and low energy consumption flat ground driving. Foot mode: When servo motor 2 is disabled, the worm gear self-locking is released, servo motor 3 drives the hip to swing and take a step, while servo motor 4 controls the planetary carrier to extend the lower leg as a supporting foot, and with the help of foot sleeves, it can complete obstacle crossing, slope climbing or walking on unstructured terrain. No additional mechanism switching is required; mode switching can be completed simply by coordinating the control of three servos. It features a compact structure, rapid response, and high reliability.

[0011] Beneficial effects: It can be used for two purposes, combining the efficiency of wheeled robots with the mobility of legged robots, and significantly expanding the robot's operating scenarios.

[0012] II. Multi-stage damping design effectively absorbs impact loads and protects the transmission system. Hip joint shock absorption: One end of the spring 7 is connected to the disc connector 4, and the other end is connected to the thrust plate 8, working in conjunction with the worm gear mechanism. When the leg encounters a vertical impact, the spring undergoes elastic deformation to buffer the instantaneous impact force from the ground. The worm gear itself has a self-locking characteristic, which, while providing posture maintenance, further contributes to vibration absorption through its meshing clearance and material elasticity.

[0013] Thigh unit flexible transmission: The third servo motor 15 drives the sun gear through a large pulley-conveyor belt-small pulley. Belt drive has the advantages of elastic buffering, vibration reduction and noise reduction. Compared with rigid gear direct connection, it can effectively attenuate torque fluctuations caused by motor start-stop or uneven road surface.

[0014] Beneficial effects: The dual shock absorption mechanism of spring and flexible belt drive significantly reduces the damage to the servo and structural components caused by impact, extends service life, and improves motion stability.

[0015] III. The planetary gear train integrates a lower leg structure to achieve structural and functional integration. The lower leg unit is constructed in the form of a planetary carrier (planetary carrier legs 24), with planetary gears 23 and sun gears 29 mounted on it via flange bearings; in wheel mode, the gear ring is fixed, the sun gear outputs to drive the tire, and the planetary carrier is stationary and retracted; in foot mode, the planetary carrier unfolds as the main body of the lower leg, and foot sleeves 30 are installed at the end to form stable support. The same gear system is used for both transmission and support structure, avoiding redundant parts.

[0016] Beneficial effects: Highly integrated design reduces the number of parts, lightens weight, and improves space utilization and structural rigidity.

[0017] IV. Combining modularity and lightweight design for easy engineering applications The hip joint, thigh unit, and calf unit are clearly separated into sections, and each module is assembled using flange bolts. The thigh shell 1 and thigh mounting bracket 2 are made of lightweight materials such as aluminum alloy or engineering plastics; the power source is centrally located (four servo motors), making wiring and maintenance convenient.

[0018] Beneficial effects: Facilitates mass production, rapid repair and platform portability, and is suitable for mobile robot platforms for inspection, rescue, exploration and other purposes.

[0019] In summary, this invention, through a comprehensive innovation combining wheeled rolling mode and legged walking mode, a multi-stage shock absorption mechanism, and the reuse of planetary structure functions, achieves the following without significantly increasing structural complexity: ① seamless switching between high-speed wheeled movement and flexible legged movement; ② a balance between strong impact resistance and stable motion; and ③ synergistic optimization of structural compactness and functional diversity. Therefore, this shock-absorbing dual-modal wheeled-legged robotic leg is particularly suitable for autonomous movement in complex unstructured environments such as urban ruins, mountainous forest areas, and staircases, demonstrating significant practical value and promising prospects for widespread application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the structure of the present invention with the outer shell of the thigh removed; Figure 4 This is a schematic diagram of the exploded structure of the present invention; In the diagram: 1. Thigh shell; 2. Thigh mounting bracket; 3. First servo motor; 4. Disc connector; 5. Thrust bearing; 6. First support component; 7. Spring; 8. Thrust disc; 9. Hip shaft; 10. Second servo motor; 11. Coupling; 12. Worm gear; 13. Worm wheel; 14. Second support component; 15. Third servo motor; 16. Large pulley; 17. Conveyor belt; 18. Small pulley; 19. Cylindrical gear; 20. Intermediate gear; 21. Gear ring; 22. Tire; 23. Planetary gear; 24. Planetary carrier leg; 26. Fourth servo motor; 7. Tensioner; 29. ​​Sun gear; 30. Foot sleeve; 35. Spring hole; 38. First flange bearing; 39. Sleeve; 41. Seventh flange bearing; 42. Sixth flange bearing; 43. Second connecting hole; 44. First connecting hole; 45. Third connecting hole; 46. Planetary gear connecting hole; 47. Sun gear connecting hole; 48. Third flange bearing; 49. Second support member; 50. Second flange bearing; 51. Fourth flange bearing; 52. Sleeve; 53. Fifth flange bearing; 54. Fourth support member. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] A shock-absorbing dual-mode wheeled mechanical leg includes a hip joint, a thigh unit, and a calf unit. The hip joint includes a support mechanism and a first transmission mechanism, a second transmission mechanism, and a third transmission mechanism mounted on the support mechanism. The movement of the hip joint drives the thigh unit and the calf unit to follow the movement. The first transmission mechanism includes a first servo motor 3. The power output end of the first servo motor 3 is connected to one end of the hip shaft 9 through a disc connector 4 and a thrust bearing 5. The thrust bearing 5 is disposed on the side plate of the first support member 6. The other end of the hip shaft 9 is connected to the third flange bearing 48 on the thrust disc 8 parallel to the side plate on the first support member 6. A spring 7 is also wound on the hip shaft 9. One end of the spring 7 is connected to the spring hole 35 on the disc connector 4, and the other end of the spring 7 is in contact with the thrust disc 8. The second transmission mechanism includes a second servo motor 10 fixed to the first support member 6. The power output end of the second servo motor 10 is connected to one end of the worm gear 12 via a coupling 11. The other end of the worm gear 12 is connected to the second support member 49 via a second flange bearing 50. The worm gear 12 meshes with the worm wheel 13. One side of the worm wheel 13 is connected to the thrust plate 8 via a third flange bearing 48. The other side of the worm wheel 13 is connected to the third flange bearing 51 of the third transmission mechanism. The third transmission mechanism includes a fourth flange bearing 51 disposed at one end of the second sleeve 52. The other end of the second sleeve 52 is connected to one side of the third support member 14 through a fifth flange bearing 53. A fourth support member 54 is disposed on the other side of the third support member 14. The third support member 14 and the fourth support member 54 are connected to the third support member 14. The thigh unit includes a thigh mounting frame 2 and a thigh shell 1 covering the thigh mounting frame 2. A large pulley 16, a tension pulley 27, a small pulley 18, and a conveyor belt 17 connecting the three are installed in sequence inside the thigh mounting frame 2. A fourth servo motor 26 is also disposed on the side of the thigh mounting frame 2 near the hip joint. The power output shaft of the fourth servo motor 26 is connected to a cylindrical gear 19 through a mounting bearing disposed in the middle of the thigh mounting frame 2. The cylindrical gear 19 meshes with an intermediate gear 20. The intermediate gear 20 meshes with the outer ring of a gear ring 21. The inner ring of the gear ring 21 meshes with a planetary gear 23. The planetary gear 23 meshes with a sun gear 29. The output end of the sun gear 29 passes through the small pulley 18 and is connected to the tire 22.

[0024] The gear shaft of the sun gear 29 is interference-fitted with the small pulley 18.

[0025] The lower leg unit includes a planetary carrier leg 24. The end of the planetary carrier leg 24 is provided with a foot sleeve 30. The other end of the planetary carrier leg 24 is provided with a planetary gear connection hole 46 and a sun gear connection hole 47. The planetary gear connection hole 46 and the sun gear connection hole 47 are respectively connected to the planetary gear 23 and the sun gear 29 through flange bearings.

[0026] The thigh shell 1 is provided with a first connecting hole 44, a second connecting hole 43, and a third connecting hole 45 from top to bottom. The power output shaft of the fourth servo motor 26 passes through the first connecting hole 44 and is adapted to connect with the cylindrical gear 19. The axle of the intermediate gear 20 is adapted to connect with the sixth flange bearing 42, the seventh flange bearing 41, and the flange bolt 40 through the second connecting hole 43. The gear ring 21 is connected to the small pulley 18 through the first flange bearing 38 and the first sleeve 39 passing through the third connecting hole 45. In this embodiment, the spring 7 in the hip joint works in conjunction with the worm gear mechanism to achieve hip shock absorption; the thigh unit uses a conveyor belt 17 for transmission to mitigate impact loads.

[0027] In this embodiment, the thigh unit has dual-mode switching capability: In this embodiment, in the wheeled working mode, the fourth servo motor 26 drives the cylindrical gear 19 → intermediate gear 20 → gear ring 21 to retract and lock the planetary carrier support leg 24, while the third servo motor (15) drives the tire 22 to roll through the conveyor belt. In this embodiment, in the foot-type working mode, the second servo motor 10 is disabled, the third servo motor 15 drives the disc connector 4 to swing the entire thigh unit to achieve leg stepping, and at the same time the fourth servo motor 26 controls the planetary carrier lower leg 24 to unfold as foot support.

[0028] In this embodiment, both planetary gear 23 and sun gear 29 are connected by flange bearings, planetary carrier legs 24, and flange bolts 32.

[0029] In this embodiment, the large pulley 16 on the thigh mounting bracket 2 is connected to the tension pulley 27 and the small pulley 18 via the conveyor belt 17. The small pulley 18 and the gear shaft of the sun gear 29 are interference-fitted. The torque transmitted by the third servo motor 15 drives the large pulley 16, the tension pulley 27 and the small pulley 18 to move, and then transmits the motion to the tire 22.

[0030] In this embodiment, the output end of the fourth servo motor 26 mounted on the thigh mounting bracket 2 is connected to the cylindrical gear 19. The cylindrical gear 19 meshes with the intermediate gear 20, the intermediate gear 20 meshes with the outer ring of the gear ring 21, the inner ring of the gear ring 21 meshes with the planet gear 23, the planet gear 23 meshes with the sun gear 29, and the other end of the sun gear 29 is connected to the tire 22. The torque output by the fourth servo motor 26 drives the cylindrical gear 19 and the intermediate gear 20, thereby fixing the gear ring 21.

[0031] The specific working states of this invention include a legged working state and a wheeled working state, and the specific implementation is as follows: In wheeled operation: The first servo motor 3 outputs torque to the large pulley 16, which is then transmitted to the tire 22 via the conveyor belt 17, tensioner 27, and small pulley 18. Simultaneously, the fourth servo motor 26 outputs torque to the cylindrical gear 19, which is then transmitted via the intermediate gear 20, gear ring 21, and planetary gears 23, thereby retracting and securing the planetary carrier support leg 24. At the same time, the third servo motor 15 of the hip joint is disabled, and the second servo motor 10 drives the worm gear to output torque to the thigh unit, controlling the height of the thigh unit's center of gravity under complex road conditions.

[0032] In leg-operated mode: The first servo motor 3 outputs torque to the large pulley 16, which is then transmitted to the tire 22 via the conveyor belt 17, tensioner 27, and small pulley 18. Simultaneously, the fourth servo motor 26 outputs torque to the cylindrical gear 19, which is transmitted via the intermediate gear 20, gear ring 21, and planetary gears 23, thereby retracting and fixing the planetary carrier support leg 24. At the same time, the second servo motor 10 at the hip joint is disabled, and the third servo motor 15 outputs torque to the disc connector 4 on the thigh unit, controlling the movement of the thigh unit.

[0033] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0034] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A shock-absorbing dual-mode wheeled mechanical leg, characterized in that: It includes a hip joint, a thigh unit, and a calf unit. The hip joint includes a support mechanism and a first transmission mechanism, a second transmission mechanism, and a third transmission mechanism mounted on the support mechanism. The movement of the hip joint drives the thigh unit and the calf unit to follow the movement. The first transmission mechanism includes a first servo motor (3). The power output end of the first servo motor (3) is connected to one end of the hip shaft (9) through a disc connector (4) and a thrust bearing (5). The thrust bearing (5) is set on the side plate of the first support member (6). The other end of the hip shaft (9) is connected to the third flange bearing (48) on the thrust plate (8) on the first support member (6) which is parallel to the side plate. A spring (7) is also wound on the hip shaft (9). One end of the spring (7) is connected to the spring hole (35) on the disc connector (4), and the other end of the spring (7) is in contact with the thrust plate (8). The second transmission mechanism includes a second servo motor (10) fixed to the first support member (6). The power output end of the second servo motor (10) is connected to one end of the worm (12) through a coupling (11). The other end of the worm (12) is connected to the second support member (49) through a second flange bearing (50). The worm (12) meshes with the worm wheel (13). One side of the worm wheel (13) is connected to the thrust plate (8) through a third flange bearing (48). The other side of the worm wheel (13) is connected to the third flange bearing (51) of the third transmission mechanism. The third transmission mechanism includes a fourth flange bearing (51) disposed at one end of the second sleeve (52), the other end of the second sleeve (52) is connected to one side of the third support member (14) through a fifth flange bearing (53), the other side of the third support member (14) is provided with a fourth support member (54), and a third servo motor (15) is connected between the third support member (14) and the fourth support member (54).

2. The shock-absorbing dual-mode wheel-foot mechanical leg according to claim 1, characterized in that, The thigh unit includes a thigh mounting frame (2) and a thigh shell (1) covering the thigh mounting frame (2); a large pulley (16), a tension pulley (27), a small pulley (18), and a conveyor belt (17) connecting the three are installed in sequence inside the thigh mounting frame (2); a fourth servo motor (26) is also provided on the side of the thigh mounting frame (2) near the hip joint. The power output shaft of the fourth servo motor (26) is connected to a cylindrical gear (19) through a mounting bearing provided in the middle of the thigh mounting frame (2). The cylindrical gear (19) meshes with an intermediate gear (20). The intermediate gear (20) meshes with the outer ring of a gear ring (21). The inner ring of the gear ring (21) meshes with a planetary gear (23). The planetary gear (23) meshes with a sun gear (29). The output end of the sun gear (29) passes through the small pulley (18) and is connected to the tire (22).

3. The shock-absorbing dual-mode wheel-foot mechanical leg according to claim 1, characterized in that, The gear shaft of the sun gear (29) is interference-fitted with the small pulley (18).

4. The shock-absorbing dual-mode wheeled mechanical leg according to claim 1, characterized in that, The lower leg unit includes a planetary carrier leg (24), the end of which is provided with a foot sleeve (30), and the other end of the planetary carrier leg (24) is provided with a planetary gear connection hole (46) and a sun gear connection hole (47). The planetary gear connection hole (46) and the sun gear connection hole (47) are respectively connected to the planetary gear (23) and the sun gear (29) through flange bearings.

5. A shock-absorbing dual-mode wheeled mechanical leg according to claim 2, characterized in that, The thigh shell (1) is provided with a first connecting hole (44), a second connecting hole (43) and a third connecting hole (45) from top to bottom. The power output shaft of the fourth servo motor (26) passes through the first connecting hole (44) and is adapted to connect with the cylindrical gear (19). The axle of the intermediate gear (20) is adapted to connect with the sixth flange bearing (42), the seventh flange bearing (41) and the flange bolt (40) through the second connecting hole (43). The gear ring (21) is connected to the small pulley (18) through the first flange bearing (38) and the first sleeve (39) passing through the third connecting hole (45).

6. A robot or walking device, including any one of the shock-absorbing dual-modal wheeled mechanical legs as described in claims 1 to 5.

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