Leg structure and robot

Abstract

The utility model relates to a leg structure and a robot, and is applied to the field of robots. The mechanism comprises a thigh driving section, a shank driving section, an execution unit, a crank and a connecting rod, the execution unit is mounted on the thigh driving section and can drive the crank to rotate around an output shaft of the execution unit; the crank is pivotally connected with the connecting rod through a first pivot, the connecting rod is pivotally connected with the shank driving section through a second pivot, the shank driving section is pivotally connected with the thigh driving section through a third pivot, and the thigh driving section is pivotally connected with the crank through a fourth pivot; the distance L1 between the first pivot axis and the fourth pivot axis is smaller than the distance L3 between the second pivot axis and the third pivot axis. The L3 is set to be smaller than the L1, so that the output torque of the motor is smaller, and the load and the power consumption of the motor are reduced. Based on the connecting rod driving scheme with the variable transmission ratio, the requirements for adjusting the speed and torque change are met, and meanwhile the production cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of robots, and in particular to a leg structure and robot. Background Technology

[0002] A key challenge in motion transmission in current robotics technology is effectively regulating changes in input and output speed and torque. To address this, traditional robot designs typically employ gears, timing belts, and cable drives to transmit and regulate power. While these methods offer relatively precise speed and torque control, they also have inherent limitations.

[0003] First, these transmission methods are relatively expensive. The production of precision components such as gears and timing belts requires complex processes and high-quality materials, which directly leads to increased manufacturing costs. Furthermore, the maintenance and replacement of these components incur additional expenses, especially in industrial applications where frequent maintenance and replacement can severely impact production efficiency and economic benefits. Utility Model Content

[0004] Therefore, it is necessary to provide a leg structure and robot to address the problem of high transmission structure costs caused by using transmission methods such as gears, synchronous belts, and rope drives to transmit and regulate power.

[0005] Firstly, this application provides a leg structure, which adopts the following technical solution:

[0006] A leg structure includes at least a thigh drive segment, a lower leg drive segment, an actuator, a crank, and a connecting rod; the actuator is mounted on the thigh drive segment and is capable of driving the crank to rotate about the output shaft of the actuator; the crank and the connecting rod are pivotally connected via a first pivot, the connecting rod is pivotally connected to the lower leg drive segment via a second pivot, the lower leg drive segment is pivotally connected to the thigh drive segment via a third pivot, and the thigh drive segment is pivotally connected to the crank via a fourth pivot; wherein a first distance L1 between the axis of the first pivot and the axis of the fourth pivot is less than a third distance L3 between the axis of the second pivot and the axis of the third pivot.

[0007] In one embodiment, the ratio of the third distance L3 to the first distance L1 is 1.1 to 1.5.

[0008] In one embodiment, the second distance L2 between the axis of the first pivot and the axis of the second pivot is equal to the fourth distance L4 between the axis of the fourth pivot and the third pivot.

[0009] In one embodiment, the third distance L3 between the axis of the second pivot and the axis of the third pivot is greater than the fourth distance L4 between the axis of the fourth pivot and the third pivot.

[0010] In one embodiment, the ratio of the third distance L3 to the fourth distance L4 is 1.1 to 1.5.

[0011] In one embodiment, the second distance L2 between the axis of the first pivot and the axis of the second pivot is equal to the third distance L3 between the axis of the second pivot and the axis of the third pivot.

[0012] In one embodiment, the leg structure further includes a first equivalent transmission unit and a second equivalent transmission unit, and the lower leg drive segment includes a drive unit and an actuator unit; the drive unit is pivotally connected to the link via a second pivot and pivotally connected to the thigh drive segment via a third pivot; the first equivalent transmission unit is pivotally connected to the drive unit via a fifth pivot and pivotally connected to the actuator unit via a sixth pivot; the second equivalent transmission unit is coaxially connected to the thigh drive segment and pivotally connected to the actuator unit via a seventh pivot; wherein, along the longitudinal direction of the drive unit, the fifth pivot is located between the second pivot and the third pivot.

[0013] In one embodiment, the fifth distance L5 between the axis of the third pivot and the axis of the fifth pivot is equal to the sixth distance L6 between the axis of the sixth pivot and the axis of the seventh pivot.

[0014] In one embodiment, the seventh distance L7 between the axis of the fifth pivot and the axis of the sixth pivot is equal to the eighth distance L8 between the axis of the third pivot and the axis of the seventh pivot.

[0015] Secondly, this application provides a robot that adopts the following technical solution:

[0016] A robot includes a body and a plurality of leg structures mounted on the body, the leg structures being the aforementioned leg structures, wherein the thigh drive segments of the leg structures are pivotally connected to the body.

[0017] The aforementioned leg structure utilizes the variable transmission ratio characteristic of the linkage mechanism, designing the transmission ratio variation range within a suitable range. Furthermore, by setting the third distance L3 to be less than the first distance L1, the output torque of the motor is reduced while maintaining the same force at the grounding end of the lower leg drive section, thereby lowering the motor's load and power consumption. Therefore, the linkage drive scheme based on the variable transmission ratio satisfies the requirements for adjusting speed and torque changes while simultaneously reducing production costs. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the leg structure in one embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the leg structure in one embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the transmission principle in one embodiment of this application.

[0021] Figure 4 This is a schematic diagram of the transmission principle in another embodiment of this application.

[0022] Attached image annotations:

[0023] 1. Thigh drive section; 2. Lower leg drive section; 21. Drive unit; 22. Actuator; 31. First actuator; 32. Second actuator; 4. Crank; 5. Connecting rod; 6. First equivalent transmission unit; 7. Second equivalent transmission unit; 8. First pivot; 9. Second pivot; 10. Third pivot; 11. Fourth pivot; 12. Fifth pivot; 13. Sixth pivot; 14. Seventh pivot. Detailed Implementation

[0024] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0026] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying 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 that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0030] A key challenge in motion transmission in current robotics technology is effectively regulating changes in input and output speed and torque. To address this, traditional robot designs typically employ gears, timing belts, and cable drives to transmit and regulate power. While these methods offer relatively precise speed and torque control, they also have inherent limitations.

[0031] First, these transmission methods are relatively expensive. The production of precision components such as gears and timing belts requires complex processes and high-quality materials, which directly leads to increased manufacturing costs. Furthermore, the maintenance and replacement of these components incur additional expenses, especially in industrial applications where frequent maintenance and replacement can severely impact production efficiency and economic benefits.

[0032] To address this issue, this application proposes a linkage transmission scheme based on a variable transmission ratio. The core of this scheme lies in using a linkage mechanism to replace traditional gear and timing belt transmission methods, thereby achieving effective regulation of speed and torque changes.

[0033] The following is in conjunction with the appendix Figure 1-4 The embodiments of this application will be described in further detail.

[0034] See Figure 1 and Figure 2 As shown, Figure 1 A three-dimensional structural diagram of the leg structure in one embodiment of this application is shown. Figure 2 A schematic diagram of a leg structure according to an embodiment of this application is shown. One embodiment of this application provides a leg structure including at least a thigh drive segment 1, a lower leg drive segment 2, an actuator, a crank 4, and a connecting rod 5. The actuator is mounted on the thigh drive segment 1, and the output shaft of the actuator is drive-connected to the crank 4. The crank 4 and the connecting rod 5 are pivotally connected via a first pivot 8. The connecting rod 5 is pivotally connected to the lower leg drive segment 2 via a second pivot 9. The lower leg drive segment 2 is pivotally connected to the thigh drive segment 1 via a third pivot 10. The thigh drive segment 1 is pivotally connected to the crank 4 via a fourth pivot 11.

[0035] Specifically, crank 4 is located on the upper part of the leg structure. Crank 4 is used to fix to the actuator. The other end of crank 4 can be a fixing hole for pivotally connecting crank 4 to connecting rod 5 via first pivot 8. The middle part of crank 4 can be a plate-like structure with lightweight features, such as a hollow design or reinforcing ribs, to ensure rigidity while reducing weight. Crank 4 is used to transmit the rotational force (torque) generated by the actuator to connecting rod 5, causing connecting rod 5 to execute the prescribed motion path.

[0036] Link 5 is located between crank 4 and lower leg drive section 2, extending from crank 4 to lower leg drive section 2. Link 5 is used to convert and transmit the motion generated by crank 4 to lower leg drive section 2, driving the lower half of the leg structure to complete a predetermined movement (such as gait swing or position adjustment). The shape of link 5 is not limited here; it can be set as a long strip or plate-shaped structure, and the cross-section of link 5 can be rectangular, circular, or I-shaped, etc.

[0037] In some embodiments, the execution unit includes a first actuator 31, which is located on the side of the crank 4 away from the connecting rod 5. The output shaft of the first actuator 31 is connected to the crank 4 to provide power to the crank 4, so that the crank 4 moves and drives the connecting rod 5 to move.

[0038] Specifically, the output shaft of the first actuator 31 can be connected to the crank 4 via a linkage mechanism (such as a gear, belt, coupling, etc.), and the first actuator 31 is used to provide a power source for the crank 4. When the first actuator 31 is activated, its power output can drive the crank 4 to rotate. The crank 4 and the connecting rod 5 can be connected via a first pivot 8, so when the first actuator 31 drives the crank 4 to rotate, the connecting rod 5 can move along with the crank 4. The first actuator 31 can be selected from appropriate actuators to provide the necessary power according to actual needs; there are no restrictions on this selection. The first actuator 31 can be an electric motor, a hydraulic cylinder, or a pneumatic drive device, etc.

[0039] In this embodiment, the output shaft of the first actuator 31 is directly connected to the crank 4. Therefore, the output of the first actuator 31 can be adjusted in real time to optimize the movement speed and force of the robotic leg, thereby adapting to different work requirements or environmental changes. The first actuator 31 drives the crank 4 through rotational motion, and then the crank 4 drives the movement of the connecting rod 5. This power transmission method is simple and efficient, avoiding complex mechanical devices, and can directly convert the power of the first actuator 31 into the movement of the connecting rod 5, improving the power utilization efficiency of the system.

[0040] In the previous exemplary embodiment, the first actuator 31 controls the crank 4 to rotate via a gear structure and a motor.

[0041] For example, the first actuator 31 is powered by an electric motor, which transmits power to a gear structure via its output shaft. The gear structure further transmits rotational force to the crank 4, thereby driving the crank 4 to rotate. The function of the gear structure is to adjust the transmitted torque and rotational speed to ensure that the crank 4 can move precisely at the required angle and speed. The electric motor can be an internal rotor motor, an external rotor motor, or an axial magnetic field motor.

[0042] Optionally, the gear structure can consist of a set of gears of different specifications and proportions. Different gear combinations can be used to amplify torque or adjust speed, thereby precisely controlling the movement of crank 4. The motor can be connected to the gear structure via a coupling, enabling the motor to drive the gear structure and, through the action of the gear structure, rotate crank 4.

[0043] In this embodiment, the rotational motion of crank 4 is controlled by the combination of a gear structure and a motor, providing efficient and precise power transmission and optimizing power regulation and transmission efficiency. Specifically, the gear structure efficiently transmits the motor's power to crank 4, ensuring effective power transmission. Furthermore, by adjusting the gear combination within the gear structure, the speed and torque can be adjusted as needed, thereby optimizing the motor's output performance.

[0044] In some embodiments, the leg structure further includes a second actuator 32, which provides power to the thigh drive segment 1 to drive the thigh drive segment 1 to move.

[0045] For example, a second actuator 32 is installed inside or on the side of the thigh drive segment 1. The output shaft of the second actuator 32 is fixedly connected to the leg of the thigh drive segment 1. The second actuator 32 can provide the necessary power to the various components of the thigh drive segment 1 through a drive mechanism (such as an electric motor or hydraulic system) to enable the thigh drive segment 1 to perform precisely controlled movements. The second actuator 32 and the thigh drive segment 1 can be connected by a fixed assembly or mechanical transmission method to ensure that the power of the second actuator 32 can be effectively transmitted to the thigh drive segment 1.

[0046] In this embodiment, the second actuator 32 provides power to the thigh drive segment 1, enabling the thigh drive segment 1 to perform complex flexion, extension, rotation and other movements. Furthermore, through precise control of the second actuator 32, the angle, position and speed of the thigh drive segment 1 can be flexibly adjusted, thereby enhancing the flexibility of the leg structure.

[0047] Combination Figure 3 As shown, Figure 3 The diagram illustrates the linkage transmission principle in one embodiment of this application. In some embodiments, the thigh drive segment 1, the lower leg drive segment 2, the crank 4, and the connecting rod 5 form a four-bar linkage. Optionally, the thigh drive segment 1 is controlled by a second actuator 32, and the movement of the thigh drive segment 1 is mainly powered by the second actuator 32, participating in the entire gait. The thigh drive segment 1, as another moving component, coordinates with the lower leg drive segment 2 in some way within the entire leg structure. The crank 4 is driven by a first actuator 31, and the connection point between the crank 4 and the connecting rod 5 transmits rotational power. Through rotation, the crank 4 causes the connecting rod 5 to shift, thereby driving the lower leg drive segment 2 to move. Through the coordinated action between the first actuator 31 and the second actuator 32, the movements of the thigh, crank 4, connecting rod 5, and lower leg form a synergistic effect.

[0048] In this embodiment, by forming a four-bar linkage between the thigh drive section 1, the lower leg drive section 2, the crank 4, and the connecting rod 5, each component can coordinate with each other during movement to complete specific actions, thus ensuring that the gait of the robotic leg is smooth and efficient.

[0049] In some embodiments, this application also makes a special design on the length ratio between the various components of the four-bar linkage, so as to utilize the variable transmission ratio characteristics of the linkage to design the transmission ratio variation range within a suitable range, thereby reducing the load and power consumption of the actuator of the leg structure during movement.

[0050] Combination Figure 2 and Figure 3 As shown, in some embodiments, the fourth pivot 11 is coaxially arranged with the output axis of the execution unit, and the first distance L1 between the axis of the first pivot 8 and the axis of the fourth pivot 11 is less than the third distance L3 between the axis of the second pivot 9 and the axis of the third pivot 10.

[0051] By setting the third distance L3 to be less than the first distance L1, the output torque of the motor is reduced when the force output at the grounding end of the lower leg drive segment 2 is the same, thereby reducing the motor load and power consumption. Therefore, the linkage 5 drive scheme based on the variable transmission ratio satisfies the requirements for adjusting speed and torque changes while reducing production costs. In this embodiment, the ratio of the third distance L3 to the first distance L1 is 1.1 to 1.5.

[0052] In some embodiments, the second distance L2 between the axis of the first pivot 8 and the axis of the second pivot 9 is equal to the fourth distance L4 between the axis of the fourth pivot 11 and the third pivot 10.

[0053] In some other embodiments, the second distance L2 between the axis of the first pivot 8 and the axis of the second pivot 9 is equal to the third distance L3 between the axis of the second pivot 9 and the axis of the third pivot 10.

[0054] In some embodiments, the third distance L3 between the axis of the second pivot 9 and the axis of the third pivot 10 is greater than the fourth distance L4 between the axis of the fourth pivot 11 and the third pivot 10; the ratio of the third distance L3 to the fourth distance L4 is 1.1 to 1.5.

[0055] Combination Figure 4 As shown, Figure 4 A schematic diagram of the linkage transmission principle is shown in another embodiment of this application. In some embodiments, the lower leg drive segment 2 includes a drive part 21 and an actuator 22 arranged at intervals. The leg structure also includes a first equivalent transmission part 6 and a second equivalent transmission part 7. The actuator 22 is connected to the drive part 21 via the first equivalent transmission part 6 and the second equivalent transmission part 7.

[0056] The drive unit 21 is pivotally connected to the link 5 via the second pivot 9 and pivotally connected to the thigh drive section 1 via the third pivot 10; the first equivalent transmission unit 6 is pivotally connected to the drive unit 21 via the fifth pivot 12 and pivotally connected to the actuator 22 via the sixth pivot 13; the second equivalent transmission unit 7 is coaxially connected to the thigh drive section 1 and pivotally connected to the actuator 22 via the seventh pivot 14; along the longitudinal direction of the drive unit 21, the fifth pivot 12 is located between the second pivot 9 and the third pivot 10.

[0057] By adopting the technical solution shown in the above embodiment, while ensuring that the third distance L3 is greater than the first distance L1, that is, the leg structure has a large transmission ratio and a small load on the drive unit, the transmission structure between the thigh drive section 1 and the calf drive section 2 can be optimized to increase the motion freedom of the actuator 22 driven by the link 5, thereby avoiding the over-constraint phenomenon of the link 5 and improving motion performance.

[0058] Specifically, the fifth distance L5 between the axis of the third pivot 10 and the axis of the fifth pivot 12 is equal to the sixth distance L6 between the axis of the sixth pivot 13 and the axis of the seventh pivot 14. The seventh distance L7 between the axis of the fifth pivot 12 and the axis of the sixth pivot 13 is equal to the eighth distance L8 between the axis of the third pivot 10 and the axis of the seventh pivot 14.

[0059] In this embodiment, the driving segment corresponding to the fifth distance L5, the execution part 22 corresponding to the sixth distance L6, the first equivalent transmission part 6, and the second equivalent transmission part 7 together form a parallelogram-shaped four-bar structure 5 to improve the motion performance of the leg structure.

[0060] In some embodiments, this application also provides a robot (not shown) including a body (not shown) and at least two leg structures mounted on both sides of the body. The leg structures are as shown in any of the above embodiments, and the thigh drive segment 1 of the leg structure is pivotally connected to the body.

[0061] In this application, the robot includes, but is not limited to, semi-mobile robots (e.g., robotic arms, linear coordinate robots, cylindrical coordinate robots, articulated robots, etc.) and mobile robots (e.g., wheeled mobile robots, walking mobile robots, crawling robots, etc.). The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A leg structure, characterized in that, The leg structure includes at least a thigh drive section, a lower leg drive section, an actuator, a crank, and a connecting rod; the actuator is mounted on the thigh drive section and is capable of driving the crank to rotate about the output shaft of the actuator; the crank and the connecting rod are pivotally connected via a first pivot, the connecting rod is pivotally connected to the lower leg drive section via a second pivot, the lower leg drive section is pivotally connected to the thigh drive section via a third pivot, and the thigh drive section is pivotally connected to the crank via a fourth pivot; Wherein, the first distance L1 between the axis of the first pivot and the axis of the fourth pivot is less than the third distance L3 between the axis of the second pivot and the axis of the third pivot.

2. The leg structure according to claim 1, characterized in that, The ratio of the third distance L3 to the first distance L1 is 1.1 to 1.

5.

3. The leg structure according to claim 1, characterized in that, The second distance L2 between the axis of the first pivot and the axis of the second pivot is equal to the fourth distance L4 between the axis of the fourth pivot and the third pivot.

4. The leg structure according to claim 1, characterized in that, The third distance L3 between the axis of the second pivot and the axis of the third pivot is greater than the fourth distance L4 between the axis of the fourth pivot and the third pivot.

5. The leg structure according to claim 4, characterized in that, The ratio of the third distance L3 to the fourth distance L4 is 1.1 to 1.

5.

6. The leg structure according to claim 1, characterized in that, The second distance L2 between the axis of the first pivot and the axis of the second pivot is equal to the third distance L3 between the axis of the second pivot and the axis of the third pivot.

7. The leg structure according to any one of claims 1-6, characterized in that, The leg structure further includes a first equivalent transmission unit and a second equivalent transmission unit. The lower leg drive segment includes a drive unit and an actuator unit. The drive unit is pivotally connected to the connecting rod via a second pivot and pivotally connected to the thigh drive segment via a third pivot. The first equivalent transmission unit is pivotally connected to the drive unit via a fifth pivot and pivotally connected to the actuator unit via a sixth pivot. The second equivalent transmission unit is coaxially connected to the thigh drive segment and pivotally connected to the actuator unit via a seventh pivot. Along the longitudinal direction of the drive unit, the fifth pivot is located between the second pivot and the third pivot.

8. The leg structure according to claim 7, characterized in that, The fifth distance L5 between the axis of the third pivot and the axis of the fifth pivot is equal to the sixth distance L6 between the axis of the sixth pivot and the axis of the seventh pivot.

9. The leg structure according to claim 8, characterized in that, The seventh distance L7 between the axis of the fifth pivot and the axis of the sixth pivot is equal to the eighth distance L8 between the axis of the third pivot and the axis of the seventh pivot.

10. A robot, characterized in that, The device includes a fuselage and a plurality of leg structures mounted on the fuselage, the leg structures being the leg structures as described in any one of claims 1-9, wherein the thigh drive segment of the leg structure is pivotally connected to the fuselage.

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