A robot leg transmission crank structure and leg assembly

Abstract

The utility model discloses a kind of robot leg transmission crank structure and leg assembly, including split first crank member and second crank member, the material strength of first crank member is higher than second crank member material strength, second crank member is connected with the motor output shaft of robot leg by fastener;Second crank member has the mounting surface connected with motor output shaft, the limit receiving groove is structured on the mounting surface;The first crank member is arranged in the limit receiving groove, first crank member is connected with motor output shaft, and the part groove wall of first crank member side wall and limit receiving groove is abutted.From the premise that the strength is not affected, the crank is designed by split structure, so that the effect of weight reduction is achieved;In addition, the crank fixed on motor output shaft is designed in split, increase the contact area of output shaft and crank, reduce the shear stress generated to crank in movement process, so that the structure is good in fracture resistance.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, and in particular to a robot leg transmission crank structure and leg assembly. Background Technology

[0002] Quadruped robots, as an important branch of robotics technology, have been widely used in various scenarios such as industrial inspection, disaster relief, and scientific research due to their excellent terrain adaptability and mobility. The leg transmission structure is the core component for quadruped robots to achieve posture adjustment and motion execution, and the crank, as a key force-bearing component in the leg transmission system, is one of the parts in quadruped robots that suffers the most wear and tear. For example, taking the parallelogram transmission scheme commonly used in the leg transmission structure of current quadruped robots as an example, the movement of the crank in this parallelogram transmission requires a large amount of power. Furthermore, due to the increasingly diverse applications of quadruped robots, there are varying degrees of demand on the robot's weight and load capacity in complex scenarios such as high load and high mobility. Higher loads place higher demands on the strength of the crank during movement. Therefore, current cranks can only achieve this high strength requirement by using high-strength materials throughout, but this significantly increases the weight of the crank, thus increasing the robot's overall weight. Summary of the Invention

[0003] This utility model addresses the shortcomings of existing technologies by providing a robot leg transmission crank structure, comprising a separate first crank component and a second crank component. The material strength of the first crank component is higher than that of the second crank component, and the second crank component is connected to the motor output shaft of the robot leg via fasteners. The second crank component has a mounting surface that connects to the motor output shaft, and a limiting receiving groove is formed on the mounting surface; The first crank component is arranged in the limiting receiving groove, the first crank component is connected to the motor output shaft, and the side wall of the first crank component abuts against part of the groove wall of the limiting receiving groove.

[0004] Preferably, the first crank component has a mounting hole, and the motor output shaft has a pin, which is connected to the first crank component through the mounting hole.

[0005] Preferably, the first crank component includes a connecting portion and a plurality of abutting portions, the plurality of abutting portions being connected to the periphery of the connecting portion respectively, the abutting portions having mounting holes for connection with pins; the abutting portions having abutting surfaces that contact the wall of the limiting receiving groove.

[0006] Preferably, the abutting parts are distributed at equal intervals around the connecting part, and the abutting parts can be pressed against the wall of the limiting receiving groove after receiving the rotational torque of the motor output shaft.

[0007] Preferably, the limiting receiving groove includes a receiving groove and a plurality of abutting grooves corresponding to the abutting part, the receiving groove and the abutting groove are in communication, the connecting part is installed in the receiving groove, and the abutting part is installed in the corresponding abutting groove; Two abutting surfaces are provided on both sides of the abutting part, and the two abutting surfaces respectively contact the two groove walls of the abutting groove.

[0008] Preferably, the second crank component includes a shaft connector, and the shaft connector has a plurality of identical crank mounting holes on the side facing the motor output shaft, with each crank mounting hole arranged circumferentially along the shaft connector; The crank mounting hole is connected to the motor output shaft via fasteners; The fastener is also provided with a double-layered self-locking washer. The fastener passes through the double-layered self-locking washer and the crank mounting hole in sequence and is then connected to the motor output shaft.

[0009] Preferably, there are three abutting parts, which are distributed at equal intervals around the connecting part. The connecting part includes a central part and three transition parts. Each abutting part is connected to the central part through a transition part, and the width of the abutting part is greater than the width of the transition part.

[0010] Preferably, the abutting surface has an angle with the circumferential side centered on and perpendicular to the motor output shaft axis.

[0011] Preferably, the second crank assembly also has a connecting rod connecting seat on the side away from the first crank assembly, the connecting rod connecting seat having a connecting groove, and shaft holes being respectively formed on both sides of the connecting groove.

[0012] This utility model also discloses a leg assembly, including a leg motor for a robot, a connecting rod, a movable part, and a robot leg transmission crank structure as described above. The motor output shaft of the leg motor is connected to a first crank and a second crank respectively. One end of the connecting rod is connected to the shaft holes on both sides of the connecting groove through an output pin, and the other end of the connecting rod is connected to the movable part. The leg motor can drive the connecting rod to move the movable part by rotating the motor output shaft.

[0013] This utility model discloses a robot leg transmission crank structure and leg assembly. The leg transmission crank structure adopts a split structure, dividing the crank structure into a first crank component with higher material strength and a second crank component with lower material strength. The second crank component is connected to the output shaft of the robot leg motor via fasteners. The first crank component is arranged in a receiving space formed by the motor output shaft and the limiting receiving groove of the second crank component. The first crank component is connected to the motor output shaft, and its side wall abuts against part of the groove wall. Thus, through the split structure design, the crank is divided into two parts made of different materials, achieving weight reduction without affecting the strength of the crank. In addition, the split design of the crank fixed to the motor output shaft increases the contact area between the output shaft and the crank, reduces the shear stress generated on the crank during movement, and makes the structure more resistant to breakage.

[0014] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0015] 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 drawings described below are only some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0016] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0017] Figure 1 This is a schematic diagram of the robot leg transmission crank structure disclosed in one embodiment of this application.

[0018] Figure 2 This is an exploded schematic diagram of the robot leg transmission crank structure disclosed in an embodiment of this application.

[0019] Figure 3-5 This is a schematic diagram showing the connection between the robot leg transmission crank structure and the motor output shaft disclosed in an embodiment of this application.

[0020] Figure 6 This is a schematic diagram of the specific structure of the first crank component disclosed in an embodiment of this application.

[0021] Figure 7 This is a schematic diagram of the installation of the first crank component and the leg motor disclosed in an embodiment of this application.

[0022] Figure label: 1. First crank assembly, 11. Mounting hole, 12. Connecting part, 13. Abutting part, 131 Abutting surface, 121. Center part, 122. Transition part; 2. Second crank assembly, 21. Fastener, 211. Double-layered self-locking washer, 22. Mounting surface, 221. Limiting receiving groove, 2211. Receiving groove, 2212. Abutting groove, 23. Shaft connector, 231. Crank mounting hole, 2311. Through hole, 24. Connecting rod connecting seat, 241. Connecting groove, 2411. Shaft hole; 100. Output pin, 200. Connecting rod, 300. Small leg motor, 301. Pin. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 utility model according to the specific circumstances.

[0026] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0027] The present invention discloses the following embodiments, specifically, as follows: Figure 1-7 As shown, a robot leg transmission crank structure is disclosed, including a split first crank component 1 and a second crank component 2. The material strength of the first crank component 1 is higher than that of the second crank component 2. The second crank component 2 is connected to the motor output shaft of the robot leg by a fastener 21. The second crank component 2 has a mounting surface 22 connected to the motor output shaft. A limiting receiving groove 221 is constructed on the mounting surface 22. The limiting receiving groove 221 and the motor output shaft surround to form a receiving space. The first crank component 1 is arranged in the limiting receiving groove 221. The first crank component 1 is connected to the motor output shaft, and the side wall of the first crank component 1 abuts against a portion of the groove wall of the limiting receiving groove 221. Specifically, the first crank component 1 can be made of high-strength materials such as structural steel, which can withstand the impact load and large stress during the robot's high-load movement, ensuring the structural rigidity of the core stress-bearing parts of the crank and avoiding the risk of breakage. The second crank component 2 can be made of lightweight materials such as aluminum alloy, which significantly reduces the overall component weight without participating in the transmission of high core stress, thereby reducing the motor drive load and improving the robot's mobility efficiency. The second crank component 2 is fixed to the motor output shaft by fasteners 21, which can ensure the stable connection between the crank assembly and the motor and avoid relative displacement during movement. In addition, when the second crank component 2 is in contact with the motor output shaft through the mounting surface 22, the limiting receiving groove 221 on the mounting surface 22 will together with the outer wall of the motor output shaft to form a receiving space. Through the abutment between the side wall of the first crank component and the inner wall of the limiting receiving groove, the area for force transmission between the crank assembly and the leg motor 300 is increased, and the shear stress is reduced, thus reducing the risk of crank breakage during movement. By splitting the crank into two parts made of different materials, the crank can be reduced in weight without affecting its strength. In addition, the split design of the crank is fixed on the motor output shaft, which increases the contact area between the output shaft and the crank, reduces the shear stress generated on the crank during operation, and makes the structure more resistant to breakage.

[0028] In this embodiment, the first crank component 1 has a mounting hole 11, and the motor output shaft has a pin 301. The pin connects to the first crank component 1 through the mounting hole 11. Specifically, the first crank component 1 is made of high-strength materials such as structural steel, and its mounting hole 11 is precisely matched with the pin of the motor output shaft. During assembly, the pin is fully inserted into the mounting hole 11 to form surface contact. When the calf motor starts and outputs torque, the power is transmitted from the motor output shaft to the pin, to the wall of the mounting hole 11, and then to the first crank component 1. Compared with the traditional point contact or line contact method, this fit greatly increases the contact area for power transmission, so that the torque is distributed across the entire wall of the mounting hole 11, effectively reducing local shear stress and preventing the first crank component 1 from breaking due to stress concentration during high-load operation.

[0029] In this embodiment, the first crank component 1 includes a connecting portion 12 and a plurality of abutting portions 13. The plurality of abutting portions 13 are respectively connected to the periphery of the connecting portion 12. The abutting portion 13 is provided with a mounting hole 11 for connecting to the pin 301. The abutting portion 13 is provided with an abutting surface 131 that contacts the groove wall of the limiting receiving groove 221.

[0030] Specifically, the connecting part 12, as the core support structure of the first crank component 1, integrates multiple abutment parts 13 into one unit. The mounting hole 11 is provided on the abutment part 13 so that the force on the pin shaft can be directly transmitted through the abutment part 13. When the first crank component 1 is installed in the limiting receiving groove 221 of the second crank component 2, the abutment surface 131 of the abutment part 13 is in close contact with the groove wall of the limiting receiving groove 221. When the calf motor outputs power, the torque of the first crank component 1 is transmitted through the mounting hole 11 on the one hand, and on the other hand, pressure is applied to the groove wall of the limiting receiving groove 221 through the multiple abutment surfaces 131, distributing part of the force to the second crank component 2, avoiding the first crank component 1 bearing the entire load alone, enhancing the connection stability of the two crank components, and preventing relative displacement during movement.

[0031] In this embodiment, the abutting parts 13 are distributed at equal intervals around the connecting part 12. After receiving the torque of the motor output shaft, the abutting parts 13 can be pressed against the wall of the limiting receiving groove 221 through the abutting surface 131.

[0032] Specifically, the abutment parts 13 are distributed at equal intervals, which makes the force points around the connecting part 12 symmetrically distributed. When the motor output shaft drives the first crank component 1 to rotate, the rotational torque is converted into the pressing force of the abutment surface 131 on the wall of the limiting receiving groove 221. Since the abutment parts 13 are evenly spaced, the pressing force is evenly distributed at different positions on the wall of the limiting receiving groove 221, and there will be no situation of excessive local pressure. This symmetrical force structure makes the cooperative force of the first crank component 1 and the second crank component 2 more stable. Even under high load and high mobility scenarios, it can avoid deformation or damage of a single abutment part due to overload, thus ensuring the overall rigidity of the crank assembly.

[0033] In this embodiment, the limiting receiving groove 221 includes a receiving groove 2211 and a plurality of abutting grooves 2212 corresponding to the abutting parts. The receiving groove 2211 and the abutting grooves 2212 are in communication. The connecting part 12 is installed in the receiving groove 2211, and the abutting part 13 is installed in the corresponding abutting groove 2212. Two abutting surfaces 131 are provided on both sides of the abutting part 13, and the two abutting surfaces 131 respectively contact the two groove walls of the abutting groove 2212.

[0034] Specifically, the receiving groove 2211 is designed specifically for the connecting part 12, which can form a wrap-around limit on the core part of the first crank component 1 to ensure that there is no radial displacement during assembly; multiple abutment grooves 2212 correspond one-to-one with the abutment part 13, further improving the assembly accuracy of the two crank components. After installation, the abutment surfaces 131 on both sides of the abutment part 13 form bidirectional contact with the two groove walls of the abutment groove 2212. When the first crank component 1 transmits torque, the compressive force acts on the groove wall of the abutment groove 2212 simultaneously through the abutment surfaces 131 on both sides. The contact area is doubled compared to single-sided contact, and the shear stress is further dispersed. At the same time, the bidirectional contact can limit the lateral sway of the abutment part 13, making the power transmission more stable.

[0035] In this embodiment, the second crank component 2 includes a shaft connector 23. The shaft connector 23 has multiple identical crank mounting holes 231 on the side facing the motor output shaft. Each crank mounting hole 231 is arranged circumferentially along the shaft connector. The inner sidewall of each crank mounting hole 231 forms a receiving groove 2211, and the opposite sides of adjacent crank mounting holes 231 form an abutment groove 2212. Each crank mounting hole 231 has a through hole 2311. The crank mounting hole 231 is connected to the motor output shaft via a fastener 21. The fastener 21 is also provided with a double-layered self-locking washer 211. The fastener passes through the double-layered self-locking washer and the crank mounting hole 231 in sequence and is then connected to the motor output shaft.

[0036] Specifically, the multiple crank mounting holes 231 of the shaft connector 23 are integrally formed by an enclosing method, which not only forms a receiving groove 2211 and abutment groove 2212 to fit the first crank part 1, but also eliminates the need for additional positioning components, making the structure of the second crank part 2 more compact and lighter. During assembly, the fastener 21 passes through the through hole 2311 of the crank mounting hole 231 and is threaded to the motor output shaft. The double-layered self-locking washer 211 can form a reliable fixation between the crank mounting hole 231 and the motor output shaft, increasing friction and preventing loosening. When the motor outputs power, the crank mounting hole 231 receives the compressive force of the first crank part 1 through the enclosing groove wall, and then transmits the force to the motor output shaft through the fastener 21, forming an integrated fixing-force transmission structure, improving the overall transmission efficiency.

[0037] In this embodiment, there are three abutting parts 13, which are distributed at the same interval around the connecting part 12. The connecting part 12 includes a central part 121 and three transition parts 122. Each abutting part 13 is connected to the central part 121 through the transition part 122. The width of the abutting part 13 is greater than the width of the transition part 122.

[0038] Specifically, the three abutment portions 13 are distributed at 120° intervals, forming the most stable triangular force-bearing structure, ensuring that the torque of the first crank component 1 during rotation is evenly transmitted to the abutment surfaces 131 in three directions. The width of the transition portion 122 is smaller than that of the abutment portions 13. While ensuring that the abutment portions 13 have sufficient width to bear the load and increasing the contact area, the material usage of the transition portion 122 is reduced, achieving a weight reduction effect. When the motor outputs torque, the central portion 121 receives the power and smoothly transmits it to each abutment portion 13 through the transition portion 122. The wide abutment portion 13 can effectively disperse stress and avoid local overload, while the narrow transition portion 122 does not add too much weight, so that the first crank component 1 achieves an optimal balance between strength and lightweight.

[0039] In this embodiment, the abutment surface 131 forms an angle with the circumferential side centered on and perpendicular to the motor output shaft axis. Specifically, the abutment surface 131 is not parallel to the circumferential side, but forms a certain angle, making the contact between the abutment surface 131 and the groove wall of the abutment groove 2213 oblique. When the first crank component 1 rotates under the drive of the motor, the compressive force converted from torque is transmitted obliquely along the abutment surface 131 to the groove wall of the abutment groove 2213. This oblique force can be decomposed into radial force and circumferential force. The radial force enhances the tightness of the contact between the two crank components, while the circumferential force directly drives the second crank component 2 to rotate synchronously, improving the power transmission efficiency. At the same time, the oblique contact method increases the friction between the abutment surface 131 and the groove wall, effectively preventing relative sliding under high load or high frequency vibration and avoiding transmission slippage.

[0040] In this embodiment, the second crank assembly 2 also has a connecting rod connecting seat 24 on the side away from the first crank assembly 1. The connecting rod connecting seat 24 has a connecting groove 241, and shaft holes 2411 are respectively formed on both sides of the connecting groove 241. Specifically, the connecting rod connecting seat 24 is the connecting bridge between the second crank assembly 2 and the connecting rod. The connecting groove 241 is used to accommodate the end of the connecting rod, and the output pins 100 can be inserted into the shaft holes 2411 on both sides, so that the connecting rod and the connecting rod connecting seat 24 form a rotatable hinge structure. When the leg motor drives the crank assembly to rotate, the power of the second crank assembly 2 is transmitted to the connecting rod through the connecting rod connecting seat 24. The connecting groove 241 limits the end of the connecting rod to prevent it from deviating during movement. The cooperation between the shaft holes 2411 and the output pin ensures that the connecting rod can swing flexibly, realizing the extension and swinging movements of the quadruped robot's legs.

[0041] In another embodiment, a leg assembly is also disclosed, including a leg motor for a robot, a linkage, a movable component, and a robot leg transmission crank structure as described above. The motor output shaft of the leg motor is connected to a first crank and a second crank respectively. One end of the linkage is connected to the shaft holes on both sides of the connecting groove through an output pin, and the other end of the linkage is connected to the movable component. The leg motor can drive the linkage to move the movable component by rotating the motor output shaft.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

[0043] In summary, the above description is only a preferred embodiment of the present utility model. All equivalent changes and modifications made within the scope of the patent application of the present utility model shall fall within the scope of the patent of the present utility model.

Claims

1. A crank structure for transmission in a robot leg, characterized in that: It includes a separate first crank component and a second crank component. The material strength of the first crank component is higher than that of the second crank component. The second crank component is connected to the motor output shaft of the robot leg by fasteners. The second crank component has a mounting surface that connects to the motor output shaft, and a limiting receiving groove is formed on the mounting surface; The first crank component is arranged in the limiting receiving groove, the first crank component is connected to the motor output shaft, and the side wall of the first crank component abuts against part of the groove wall of the limiting receiving groove.

2. The robot leg transmission crank structure according to claim 1, characterized in that: The first crank component has a mounting hole, and the motor output shaft has a pin, which is connected to the first crank component through the mounting hole.

3. The robot leg transmission crank structure according to claim 2, characterized in that: The first crank component includes a connecting part and a plurality of abutting parts, the plurality of abutting parts being connected to the periphery of the connecting part respectively, the abutting parts having mounting holes for connecting to pins; the abutting parts having abutting surfaces that contact the wall of the limiting receiving groove.

4. The robot leg transmission crank structure according to claim 3, characterized in that: The abutting parts are distributed at equal intervals around the connecting part. After receiving the torque of the motor output shaft, the abutting parts can press against the wall of the limiting receiving groove through the abutting surfaces.

5. The robot leg transmission crank structure according to claim 3, characterized in that: The limiting receiving groove includes a receiving groove and a plurality of abutting grooves corresponding to the abutting part. The receiving groove and the abutting groove are connected. The connecting part is installed in the receiving groove, and the abutting part is installed in the corresponding abutting groove. Two abutting surfaces are provided on both sides of the abutting part, and the two abutting surfaces respectively contact the two groove walls of the abutting groove.

6. The robot leg transmission crank structure according to claim 5, characterized in that: The second crank assembly includes a shaft connector, which has multiple identical crank mounting holes on the side facing the motor output shaft, with each crank mounting hole arranged circumferentially along the shaft connector. The crank mounting hole is connected to the motor output shaft via fasteners; The fastener is also provided with a double-layered self-locking washer. The fastener passes through the double-layered self-locking washer and the crank mounting hole in sequence and is then connected to the motor output shaft.

7. The robot leg transmission crank structure according to any one of claims 3-6, characterized in that: There are three abutting parts, which are distributed at equal intervals around the connecting part. The connecting part includes a central part and three transition parts. Each abutting part is connected to the central part through the transition parts. The width of the abutting part is greater than the width of the transition parts.

8. The robot leg transmission crank structure according to any one of claims 3-6, characterized in that: The abutting surface forms an angle with the circumferential side that is centered on and perpendicular to the motor output shaft axis.

9. The robot leg transmission crank structure according to claim 8, characterized in that: The second crank assembly also has a connecting rod connecting seat on the side away from the first crank assembly. The connecting rod connecting seat has a connecting groove, and shaft holes are respectively formed on both sides of the connecting groove.

10. A leg assembly, characterized in that, The invention includes a leg motor, a linkage, a movable component, and a robot leg transmission crank structure as described in any one of claims 1-9. The motor output shaft of the leg motor is connected to a first crank and a second crank respectively. One end of the linkage is connected to the shaft holes on both sides of the connecting groove via an output pin, and the other end of the linkage is connected to the movable component. The leg motor can drive the linkage to move the movable component by rotating the motor output shaft.

Images