Foot type robot and motor transmission structure and driving assembly thereof

Abstract

The utility model provides a foot type robot and a motor transmission structure and a driving assembly thereof. The motor transmission structure of the foot type robot comprises a driving shaft and a gear. Three outer arc-shaped curved surfaces are arranged on the peripheral side wall of the driving shaft, the three outer arc-shaped curved surfaces are uniformly arranged around the driving shaft, and an outer fillet is formed at the joint of any two adjacent outer arc-shaped curved surfaces; a shaft hole is formed in the gear, three inner fillets are formed on the inner wall of the shaft hole, at least part of the driving shaft penetrates through the shaft hole, the outer arc-shaped curved surface abuts against the inner wall of the shaft hole, and the outer fillets abut against the inner fillets correspondingly. According to the motor transmission structure of the foot type robot, through the design of the outer arc-shaped curved surface and the outer circular bead, the driving shaft and the shaft hole of the gear are more convenient to machine, the machining precision is improved, the concentricity is high, stress concentration is avoided, and the service life is prolonged. And the torque transmission requirement and the structural stability requirement are met while the sizes of the driving shaft and the shaft hole are reduced.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, specifically to a legged robot and its motor transmission structure and drive components. Background Technology

[0002] Legged robots are dexterous and maneuverable, capable of autonomous operation, and have a wide range of applications, including aerospace, industry, and civilian fields. They are gradually becoming a landmark research hotspot for the next generation of intelligent mobile robots.

[0003] Legged robots typically consist of a body, several joint modules, a thigh assembly hinged to the body, and a lower leg assembly hinged to the thigh assembly. The joint modules drive the thigh or lower leg assembly to move. Each joint module usually includes a motor and gears. The motor's drive shaft is connected to the gear. Because the joint module has a relatively large output torque, the motor's drive shaft cannot be interference-fitted with the gear's shaft hole to achieve circumferential positioning between them. Therefore, the motor's drive shaft is usually equipped with a spline or flat key structure. The spline or flat key structure passes through the gear's shaft hole, enabling circumferential positioning between the joint motor's drive shaft and the gear. However, the spline is complex to machine, which also increases the machining difficulty of the gear's shaft hole. Moreover, the stress of the spline is mainly concentrated at the tooth root, making the tooth root prone to breakage. On the other hand, the stress of the flat key is concentrated at the sharp corner, resulting in a small stress-bearing area. Furthermore, the sharp corner inside the gear's shaft hole is difficult to form through machining processes. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies in the existing technology and to provide a legged robot and its motor transmission structure and drive components.

[0005] One embodiment of this utility model provides a motor transmission structure for a legged robot, including: a drive shaft and gears;

[0006] The outer peripheral sidewall of the drive shaft is provided with three outer arc-shaped curved surfaces, which are arranged around the drive shaft. Any two adjacent outer arc-shaped curved surfaces are connected to each other, and an outer fillet is formed at the connection point of any two adjacent outer arc-shaped curved surfaces.

[0007] The gear is provided with a shaft hole, the inner wall of the shaft hole is formed with three inner rounded corners, at least a portion of the drive shaft passes through the shaft hole, at least a portion of the outer arc-shaped surface abuts against the inner wall of the shaft hole, and the outer rounded corner abuts against the inner rounded corner.

[0008] In some optional embodiments, the inner wall of the shaft hole is formed with three inner arc-shaped surfaces, the three inner arc-shaped surfaces are arranged around the shaft hole, any two adjacent inner arc-shaped surfaces are connected to each other, and an outer fillet is formed at the connection of any two adjacent inner arc-shaped surfaces.

[0009] The inner arc-shaped surface and the outer arc-shaped surface abut against each other.

[0010] In some alternative embodiments, a first positioning stage is provided on the drive shaft, and the end of the first positioning stage engages with the gear positioning to position the gear relative to the drive shaft.

[0011] In some optional embodiments, the motor transmission structure of the legged robot further includes a flange, one side of which is provided with the drive shaft, and the other side of which is connected to the output end of the motor. The drive shaft and the flange are provided with weight reduction holes, and the weight reduction holes of the drive shaft and the flange are interconnected.

[0012] In some alternative embodiments, the radii and angles corresponding to each of the outer arcuate surfaces are the same on the radial cross-section of the drive shaft.

[0013] Another embodiment of this utility model provides a drive component for a legged robot, including: a motor and a motor transmission structure for a legged robot as described above, wherein the output end of the motor is connected to the drive shaft.

[0014] In some alternative embodiments, a positioning groove is provided on the output end, and a second positioning stage is provided on the drive shaft. The second positioning stage is positioned and engaged with the positioning groove to limit the radial position of the drive shaft relative to the output end.

[0015] In some optional embodiments, the inner wall of the positioning groove is provided with a plurality of recesses arranged sequentially along the circumference of the output end, and the side of the second positioning platform is provided with a plurality of protrusions, which are correspondingly arranged in the recesses to limit the circumferential position of the second positioning platform relative to the output end.

[0016] In some optional embodiments, the motor drive structure of the legged robot further includes a flange, the second positioning platform and the drive shaft are respectively disposed on both sides of the flange, the side of the flange facing the second positioning platform is connected to the output end of the motor, the flange is provided with a plurality of first flange holes and a plurality of locking elements, the plurality of first flange holes are arranged around the second positioning platform, the flange is provided with a plurality of second flange holes, the second flange holes are arranged corresponding to the first flange holes, and the locking elements pass through the first flange holes and the second flange holes to lock the flange onto the output end.

[0017] Another embodiment of this utility model provides a legged robot, including: a drive assembly for a legged robot as described above.

[0018] Compared with the prior art, the motor transmission structure of the legged robot of this utility model, through the design of the outer arc surface and outer rounded corners, makes the machining of the shaft hole of the drive shaft and gear more convenient, improves the machining accuracy, and has high concentricity. When the motor outputs torque to the gear through the drive shaft, the large contact area of ​​the outer rounded corner and inner rounded corner helps to disperse stress, thereby avoiding stress concentration. This helps to meet the torque transmission requirements and structural stability requirements while reducing the size of the drive shaft and shaft hole.

[0019] To provide a clearer understanding of this invention, the specific embodiments of the invention will be described below in conjunction with the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the drive assembly of a legged robot according to an embodiment of the present invention;

[0021] Figure 2 An exploded view of the drive assembly of a legged robot according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of one side of the drive shaft according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of a gear according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the other side of the drive shaft according to one embodiment of the present invention;

[0025] Figure 6 This is a cross-sectional view of the drive shaft according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 10. Motor; 11. Output end; 111. Second flange hole; 112. Positioning groove; 1121. Recess; 20. Drive shaft; 21. Outer arc surface; 22. Outer fillet; 23. First positioning platform; 24. Second positioning platform; 241. Protrusion; 25. Weight reduction hole; 30. Gear; 31. Shaft hole; 311. Inner fillet; 312. Inner arc surface; 40. Flange; 41. First flange hole. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model. In the description of the present utility model, unless otherwise stated, "a plurality of" means two or more, and "a number" means one or more. In addition, unless otherwise stated, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0029] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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.

[0030] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] In the description of this utility model, references to terms such as "one embodiment," "some alternative implementations," or "some optional embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] In existing technologies, the joint modules of legged robots typically include motors and gears. The motor's drive shaft is connected to the gear. Due to the relatively large output torque of the joint module, the motor's drive shaft cannot be interference-fitted with the gear's shaft hole to achieve circumferential positioning between them. Therefore, the motor's drive shaft is usually equipped with a spline or flat key structure, which passes through the gear's shaft hole, enabling circumferential positioning between the joint motor's drive shaft and the gear. However, the complex machining of splines also increases the machining difficulty of the gear's shaft hole. Moreover, the stress of splines is mainly concentrated at the tooth root, making the tooth root prone to breakage. Flat keys, on the other hand, have stress concentrated at sharp corners, resulting in a small stress-bearing area. Furthermore, the sharp corners inside the gear's shaft hole are difficult to form through machining processes. It should be noted that in machining processes, machining is usually performed by rotating the tool or workpiece. Machining curved structures is relatively convenient and precise, but sharp corners are difficult to machine accurately, especially internal sharp corners, which are difficult for the tool to machine through machining processes.

[0033] In this invention, the outer circumferential surface of the drive shaft is composed of arc-shaped curved surfaces, and the shape of the shaft hole is matched with the shape of the drive shaft. Therefore, the drive shaft and shaft hole are easier to process, shortening the processing time and avoiding stress concentration. The high concentricity of the drive shaft and shaft hole allows the drive shaft and shaft hole to be designed to be relatively small while still meeting the requirements of large torque transmission and maintaining structural stability.

[0034] Please see Figure 1 One embodiment of the present invention provides a driving component for a legged robot, including: a motor 10 and a motor transmission structure for the legged robot.

[0035] The motor transmission structure of the legged robot includes: a drive shaft 20 and a gear 30.

[0036] Please see Figure 2 and Figure 3The outer peripheral sidewall of the drive shaft 20 is provided with three outer arc-shaped curved surfaces 21, which are arranged around the drive shaft 20. Any two adjacent outer arc-shaped curved surfaces 21 are connected to each other, and an outer fillet 22 is formed at the connection of any two adjacent outer arc-shaped curved surfaces 21. The gear 30 is provided with a shaft hole 31, and the inner wall of the shaft hole 31 is formed with three inner fillets 311. At least a part of the drive shaft 20 passes through the shaft hole 31, and at least a part of the outer arc-shaped curved surfaces 21 abuts against the inner wall of the shaft hole 31. The outer fillets 22 and the inner fillets 311 abut against each other.

[0037] The output end 11 of the motor 10 is connected to the drive shaft 20, and the output end 11 of the motor 10 drives the gear 30 to rotate through the drive shaft 20. It should be noted that the output end 11 of the motor 10 can be the rotor end of the motor 10, or it can be a structure connected to the rotor of the motor 10. For example, in this embodiment, the rotor of the motor 10 is connected to a reducer, the output end 11 is the planetary disk of the reducer, and the drive shaft 20 is connected to the planetary carrier of the reducer.

[0038] Both the outer fillet 22 and the inner fillet 311 have curved surfaces, resulting in a large contact area. This avoids stress concentration, allowing the drive shaft 20 and shaft hole 31 to be designed to be relatively small while still meeting the requirements for high torque transmission and maintaining structural stability. This is beneficial for miniaturization and simplification of the structure.

[0039] In addition, the design of the outer arc surface 21, outer fillet 22, and inner fillet 311 makes the machining of the shaft hole 31 of the drive shaft 20 and gear 30 more convenient, reduces the machining difficulty, improves the machining accuracy, shortens the machining time, and improves the production efficiency.

[0040] Please see Figure 3 and Figure 4In some optional embodiments, the inner wall of the shaft hole 31 is formed with three inner arc-shaped curved surfaces 312, which are arranged around the shaft hole 31. Any two adjacent inner arc-shaped curved surfaces 312 are connected to each other, and an outer fillet 22 is formed at the connection between any two adjacent inner arc-shaped curved surfaces 312. The inner arc-shaped curved surfaces 312 and the outer arc-shaped curved surfaces 21 are in corresponding contact. Since the inner wall of the shaft hole 31 is also formed with inner arc-shaped curved surfaces 312, the inner arc-shaped curved surfaces 312 and the outer arc-shaped curved surfaces 21 are in surface contact, which makes the shaft hole 31 and the drive shaft 20 fit more closely, improves the assembly accuracy, and improves the concentricity of the shaft hole 31 and the drive shaft 20, thereby making the force between the inner arc-shaped curved surfaces 312 and the outer arc-shaped curved surfaces 21 more uniform. Of course, in other embodiments, other types of curved surface structures can also be designed between adjacent inner rounded corners 311, so that the outer arc-shaped curved surface 21 only partially fits the inner wall of the shaft hole 31, thereby meeting the design layout needs of other structures. For example, a groove structure located between two adjacent inner rounded corners 311 can also be provided on the inner wall of the shaft hole 31.

[0041] Please see Figure 2 In some optional embodiments, a first positioning platform 23 is provided on the drive shaft 20. The drive shaft 20 is located at the end of the first positioning platform 23. The end of the first positioning platform 23 is positioned and engaged with the gear 30 to position the axial position of the gear 30 relative to the drive shaft 20, thereby maintaining a certain distance between the drive shaft 20 and the gear 30, so that the position of the gear 30 is stable and meets the requirements.

[0042] Please see Figure 3 In some optional embodiments, the radii and angles corresponding to each outer arc-shaped surface 21 on the radial cross-section of the drive shaft 20 are the same, making the positions of each outer arc-shaped surface 21 relative to the axis of the drive shaft 20 the same. This is more conducive to centering the drive shaft 20 when it passes through the shaft hole 31 of the gear 30, improving the concentricity between the shaft hole 31 and the drive shaft 20. Of course, in other embodiments, the radii corresponding to different outer arc-shaped surfaces 21 may also be different.

[0043] Please see Figure 2 and Figure 5 In some optional embodiments, a positioning groove 112 is provided on the output end 11, and a second positioning platform 24 is provided on the drive shaft 20. The second positioning platform 24 is located on the side of the drive shaft 20 close to the positioning groove 112. The second positioning platform 24 and the positioning groove 112 are matched to limit the radial position of the drive shaft 20 relative to the output end 11, thereby improving the stability between the output end 11 and the drive shaft 20. Moreover, when the drive shaft 20 is connected to the output end 11, the second positioning platform 24 and the positioning groove 112 play a role in pre-positioning, which facilitates production and assembly.

[0044] In some embodiments, the motor 10 transmission structure of the legged robot further includes a flange 40, with a drive shaft 20 on one side of the flange 40 and the other side of the flange 40 connected to the output end 11 of the motor 10. Alternatively, the motor transmission structure of the legged robot may not include the flange 40, and the drive shaft 20 can be directly connected to the output end 11 of the motor without the flange 40. Of course, in other embodiments, the drive shaft 20 is not limited to being connected to the output end 11 of the motor via the flange 40; the drive shaft 20 can also be connected to the output end 11 of the motor via other connection structures. In this embodiment, a first positioning boss 22 and a second positioning platform 24 are disposed on the flange 40, and the second positioning platform 24 and the first positioning boss 22 are respectively located on opposite sides of the flange 40. The drive shaft 20 is located on the side of the first positioning boss 22 away from the flange 40, and the side of the flange 40 closest to the second positioning boss 24 is connected to the output end 20 of the motor 10.

[0045] Please see Figure 2 The connection method between the flange 40 and the output end 11 can be selected according to actual needs. For example, in this embodiment, the flange 40 is provided with a plurality of first flange holes 41 and a plurality of locking elements (not shown). The plurality of first flange holes 41 are arranged around the second positioning boss 24. The output end 11 is provided with a plurality of second flange holes 111, which are arranged correspondingly to the first flange holes 41. The locking elements pass through the first flange holes 41 and the second flange holes 111 to lock the flange 40 onto the output end 11. The locking elements can be threaded parts, pins, etc. In one embodiment, the locking element is a bolt. The bolt passes through the first flange hole 41 and then engages with the second flange hole 111 by thread, so that the flange 40 is locked onto the output end 11. In addition, during the installation process, the second positioning platform 24 and the positioning groove 112 mentioned above can cooperate to play a pre-positioning role, which can prevent the first flange holes 41 and the second flange holes 111 from radially offset relative to the output end 11, and facilitate the alignment of the first flange holes 41 and the second flange holes 111.

[0046] Please see Figure 2 and Figure 5In some optional embodiments, the inner wall of the positioning groove 112 is provided with a plurality of recesses 1121 arranged sequentially along the circumference of the output end 11, and the side of the second positioning platform 24 is provided with a plurality of protrusions 241, which are correspondingly arranged in the recesses 1121 to limit the circumferential position of the second positioning platform 24 relative to the output end 11, thereby improving the stability between the output end 11 and the drive shaft 20. Moreover, when the drive shaft 20 is connected to the output end 11, the recesses 1121 and the protrusions 241 play a pre-positioning role, which facilitates production assembly. For example, in this embodiment, the recesses 1121 and the protrusions 241 play a pre-positioning role, which can prevent the first flange hole 41 and the second flange hole 111 from shifting upward in the circumferential direction relative to the output end 11, and facilitate the alignment of the first flange hole 41 and the second flange hole 111.

[0047] In addition, in this embodiment, the recessed portion 1121 and the protruding portion 241 can also cooperate to transmit torque, avoid stress concentration on the bolts passing through the first flange hole 41 and the second flange hole 111, and improve the stability of the structure.

[0048] Please see Figure 5 and Figure 6 In some optional embodiments, the second positioning table 24, flange 40, first positioning table 23, and drive shaft 20 are all provided with weight-reducing holes 25. The weight-reducing holes 25 of the second positioning table 24, flange 40, first positioning table 23, and drive shaft 20 are sequentially connected. The weight-reducing holes 25 correspondingly reduce the weight of the second positioning table 24, flange 40, first positioning table 23, and drive shaft 20, making the structure lighter and saving materials. Moreover, the interconnectedness of the various weight-reducing holes 25 facilitates processing. Of course, in other embodiments, for example, when the first positioning platform 23 is not provided, weight reduction holes 25 are provided on the second positioning platform 24, the flange 40, and the drive shaft 20, and the weight reduction holes 25 of the second positioning platform 24, the flange 40, and the drive shaft 20 are connected in sequence; or, when the second positioning platform 24 is not provided, weight reduction holes 25 are provided on the flange 40, the first positioning platform 23, and the drive shaft 20, and the weight reduction holes 25 of the flange 40, the first positioning platform 23, and the drive shaft 20 are connected in sequence; or, when the first positioning platform 23 and the second positioning platform 24 are not provided, weight reduction holes 25 are provided on the flange 40 and the drive shaft 20, and the weight reduction holes 25 of the flange 40 and the drive shaft 20 are connected in sequence.

[0049] The aforementioned driving component for a legged robot can be applied to a legged robot, which includes: the driving component for a legged robot as described above.

[0050] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A motor transmission structure for a legged robot, characterized in that, include: Drive shaft (20) and gear (30); The outer peripheral sidewall of the drive shaft (20) is provided with three outer arc-shaped curved surfaces (21). The three outer arc-shaped curved surfaces (21) are arranged around the drive shaft (20). Any two adjacent outer arc-shaped curved surfaces (21) are connected to each other, and an outer fillet (22) is formed at the connection of any two adjacent outer arc-shaped curved surfaces (21). The gear (30) is provided with a shaft hole (31), and the inner wall of the shaft hole (31) is formed with three inner rounded corners (311). At least a portion of the drive shaft (20) passes through the shaft hole (31), and at least a portion of the outer arc-shaped surface (21) abuts against the inner wall of the shaft hole (31). The outer rounded corner (22) abuts against the inner rounded corner (311) respectively.

2. The motor transmission structure for a legged robot according to claim 1, characterized in that: The inner wall of the shaft hole (31) is formed with three inner arc-shaped curved surfaces (312). The three inner arc-shaped curved surfaces (312) are arranged around the shaft hole (31). Any two adjacent inner arc-shaped curved surfaces (312) are connected to each other, and an outer fillet (22) is formed at the connection of any two adjacent inner arc-shaped curved surfaces (312). The inner arc-shaped surface (312) and the outer arc-shaped surface (21) are in contact with each other.

3. The motor transmission structure for a legged robot according to claim 1, characterized in that: A first positioning platform (23) is provided on the drive shaft (20), and the end of the first positioning platform (23) is positioned and engaged with the gear (30) to position the gear (30) relative to the drive shaft (20).

4. The motor transmission structure for a legged robot according to claim 1, characterized in that: The motor transmission structure of the legged robot also includes a flange (40), on one side of which is the drive shaft (20), and on the other side of which is connected to the output end of the motor. The drive shaft (20) and the flange (40) are provided with weight reduction holes (25), and the weight reduction holes (25) of the drive shaft (20) and the weight reduction holes (25) of the flange (40) are interconnected.

5. The motor transmission structure for a legged robot according to any one of claims 1 to 4, characterized in that: On the radial section of the drive shaft (20), the radii and angles corresponding to each of the outer arc surfaces (21) are the same.

6. A drive assembly for a legged robot, characterized in that, include: The motor (10) and the motor drive structure of a legged robot as described in any one of claims 1 to 5, wherein the output end (11) of the motor (10) is connected to the drive shaft (20).

7. The driving assembly for a legged robot according to claim 6, characterized in that: The output end (11) is provided with a positioning groove (112), and the drive shaft (20) is provided with a second positioning platform (24). The second positioning platform (24) is positioned and cooperates with the positioning groove (112) to limit the radial position of the drive shaft (20) relative to the output end (11).

8. The driving assembly for a legged robot according to claim 7, characterized in that: The inner wall of the positioning groove (112) is provided with a plurality of recesses (1121) arranged sequentially along the circumference of the output end (11), and the side of the second positioning platform (24) is provided with a plurality of protrusions (241), which are correspondingly arranged in the recesses (1121) to limit the circumferential position of the second positioning platform (24) relative to the output end (11).

9. The driving assembly for a legged robot according to claim 7, characterized in that: The motor drive structure of the legged robot also includes a flange (40). The second positioning platform (24) and the drive shaft (20) are respectively disposed on both sides of the flange (40). The side of the flange (40) facing the second positioning platform (24) is connected to the output end (11) of the motor (10). The flange (40) is provided with a plurality of first flange holes (41) and a plurality of locking elements. The plurality of first flange holes (41) are arranged around the second positioning platform (24). The flange (40) is provided with a plurality of second flange holes (111). The second flange holes (111) are arranged corresponding to the first flange holes (41). The locking elements are inserted through the first flange holes (41) and the second flange holes (111) to lock the flange (40) onto the output end (11).

10. A legged robot, characterized in that, include: A drive assembly for a legged robot as described in any one of claims 5 to 9.

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