Multi-degree-of-freedom transmission device and robot

Abstract

The multi-degree-of-freedom transmission device (1) includes a first platform (10), a second platform (20), a fixed platform (30), a first branch chain (40), a second branch chain (50), and a transmission assembly (60). The first branch chain (40), the first platform (10), and the fixed platform (30) form a first multi-degree-of-freedom parallel mechanism having an output end (80). The second branch chain (50), the second platform (20), and the fixed platform (30) form a second multi-degree-of-freedom parallel mechanism having an input end (90). The structure of the second branch chain (50) is similar to that of the first branch chain (40), and the size of the second branch chain is scaled proportionally to the first branch chain (40). The transmission assembly (60) is configured to couple the output end (80) to the input end (90).

Description

Technical Field

[0001] The present invention relates to the technical field of transmission devices, and particularly to multi-degree-of-freedom transmission devices and robots.

Background Art

[0002] In many industrial scenarios, there is a demand to increase the output force and torque. For example, in order to achieve the production process of a product, by implementing force and torque amplification technologies and devices, it is possible to provide relatively small forces and torques at the input end. In the prior art, in order to increase the output force and torque, a reduction gearbox or a torque converter is usually used. However, the methods for increasing the above-mentioned output force and torque are limited to only one spatial degree of freedom. In the industry, the use of parallel robots for operations such as gripping and moving workpieces in a three-dimensional space is increasing. Existing parallel robots cannot increase the force and torque output with multiple degrees of freedom. Therefore, when gripping and moving a workpiece, in order to complete the above operations, it is necessary to apply sufficient force and torque to the stress part of the parallel robot, and the application of the parallel robot will undoubtedly be limited.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, there is a need to provide a multi-degree-of-freedom transmission device and robot that solves the problem of not being able to increase the output of force and torque at multiple degrees of freedom, as is the case with conventional technology. [Means for solving the problem]

[0005] A multi-degree-of-freedom transmission device comprising a first platform, a second platform, a fixed platform installed between the first platform and the second platform, a plurality of first branch chains, a plurality of second branch chains, and a plurality of transmission assemblies, wherein the plurality of first branch chains are arranged in a sequence between the first platform and the fixed platform, the plurality of first branch chains, the first platform, and the fixed platform constitute a first multi-degree-of-freedom parallel mechanism, and the plurality of second branch chains are arranged in a sequence between the second platform The plurality of second branch chains, the second platform, and the fixed platform are arranged in a sequence between the M and the fixed platform, and the plurality of second branch chains, the second platform, and the fixed platform constitute a second multi-degree-of-freedom parallel mechanism, the structure of the second branch chain being similar to the structure of the first branch chain, the size of the second branch chain being proportionally larger or smaller than the size of the first branch chain, and the plurality of transmission assemblies being coupled between the plurality of first branch chains and the plurality of second branch chains, and configured to couple the output terminal of the first multi-degree-of-freedom parallel mechanism to the input terminal of the second multi-degree-of-freedom parallel mechanism.

[0006] In one embodiment, the plurality of transmission assemblies connect the output terminal of the first multi-degree-of-freedom parallel mechanism to the input terminal of the second multi-degree-of-freedom parallel mechanism at a speed ratio of 1:1.

[0007] In one embodiment, the plurality of first branch chains includes three first branch chains, the plurality of second branch chains includes three second branch chains, the three first branch chains, the first platform, and the fixed platform constitute a first 3-RRRS parallel mechanism, and the three second branch chains, the second platform, and the fixed platform constitute a second 3-RRRS parallel mechanism.

[0008] In one embodiment, any of the plurality of first branch chains includes, in order, a first ball pair, a first rotation pair, a second rotation pair, and a third rotation pair, the first ball pair being connected to the first platform, the third rotation pair being connected to the fixed platform, and the first and second rotation pairs being the output terminals of the first multi-degree-of-freedom parallel mechanism. Any of the second branch chains includes, in order, a second ball pair, a fourth rotation pair, a fifth rotation pair, and a sixth rotation pair, the second ball pair being connected to the second platform, the fourth rotation pair being connected to the fixed platform, and the fifth and sixth rotation pairs being the input terminals of the second multi-degree-of-freedom parallel mechanism.

[0009] In one embodiment, any of the plurality of transmission assemblies includes a first bevel gear connected to the first pair of rotations, a second bevel gear connected to the second pair of rotations, a third bevel gear connected to the fifth pair of rotations, a fourth bevel gear connected to the sixth pair of rotations, and a linkage assembly, wherein the linkage assembly is configured to transmit the rotation of the first bevel gear to the third bevel gear and the rotation of the second bevel gear to the fourth bevel gear.

[0010] In one embodiment, the linkage assembly includes a first group of transmission shafts, a second group of transmission shafts, and a third group of transmission shafts, each of the first group of transmission shafts, the second group of transmission shafts, and the third group of transmission shafts each includes a first shaft and a second shaft rotatably housed in the first shaft, the ends of the first group of transmission shafts are located on both sides of the fixed platform, the second group of transmission shafts and the third group of transmission shafts are located on one side of the fixed platform, the first group of transmission shafts and the third group of transmission shafts are connected perpendicularly to both ends of the second group of transmission shafts, each second shaft is covered with a fifth bevel gear, and each first shaft is covered with a sixth bevel gear, and the first The fifth and sixth bevel gears located at the ends of the transmission shaft group adjacent to the first branch chain mesh with the first and second bevel gears, respectively; the fifth and sixth bevel gears located at the ends of the third transmission shaft group adjacent to the second branch chain mesh with the third and fourth bevel gears, respectively; the fifth and sixth bevel gears located at both ends of the second transmission shaft group mesh with the fifth and sixth bevel gears located at the ends of the first transmission shaft group away from the first branch chain, respectively, and mesh with the fifth and sixth bevel gears located at the ends of the third transmission shaft group away from the second branch chain.

[0011] In one embodiment, the fixed platform further includes a plurality of support plates fixed to the side of the fixed platform on which the second group of transmission shafts and the third group of transmission shafts are located, each of the plurality of support plates having a group of support holes, and each of the second group of transmission shafts is rotatably housed in the group of support holes.

[0012] In one embodiment, the fixed platform includes a fixed plate, three first connecting frames, and three second connecting frames, wherein the fixed plate includes a central portion and three positioning portions arranged at equal intervals around the central portion, the three first connecting frames each fixed to the ends of the three positioning portions away from the central portion and located on the side of the fixed plate facing the first platform, and the three second connecting frames each fixed to the ends of the three positioning portions adjacent to the central portion and located on the side of the fixed plate facing the second platform.

[0013] In one embodiment, a first through hole is provided at the end of each positioning portion away from the central portion, and the first connecting frame includes two first fixing pieces fixed perpendicularly to the fixing plate and a first pressure receiving piece perpendicularly connected between the two first fixing pieces, the first pressure receiving piece having a first positioning hole corresponding to the first through hole, and a part of the transmission assembly is rotatably housed in the first through hole and the first positioning hole.

[0014] A robot comprising the multi-degree-of-freedom transmission device described above, wherein the first platform is a force input platform and the second platform is a force output platform.

[0015] According to the multi-degree-of-freedom transmission device and robot of this disclosure, when a platform connected to the larger of the first and second branch chains functions as a force input platform, the force and / or torque received by the force input platform is transmitted to a force output platform connected to the smaller of the first and second branch chains via two multi-degree-of-freedom parallel mechanisms located on both sides of the fixed platform. This increases the multi-degree-of-freedom force and / or torque output to the platform connected to the smaller branch chain and decreases the displacement output to the platform. Alternatively, when a platform connected to the smaller of the first and second branch chains functions as a force input platform, the force and / or torque received by the force input platform is transmitted to a force output platform connected to the larger of the first and second branch chains via two multi-degree-of-freedom parallel mechanisms located on both sides of the fixed platform. This decreases the multi-degree-of-freedom force and / or torque output to the platform connected to the larger branch chain and increases the displacement output to the platform. In this way, the force / torque at multiple degrees of freedom output can be increased or decreased as needed, or the displacement at multiple degrees of freedom output can be increased or decreased.

[0016] The above and other objectives, advantages, purposes and features of this disclosure will become apparent from the description herein and the accompanying drawings.

[0017] Hereinafter, technical means according to embodiments of the present invention or prior art will be described with reference to the drawings. Note that the accompanying drawings in the following description only show a part of the embodiments of the present invention, and it will be apparent to those skilled in the art that other drawings can be derived from these accompanying drawings. [Brief explanation of the drawing]

[0018] [Figure 1] This is a perspective view of a multi-degree-of-freedom transmission device according to one embodiment of the present disclosure.

[0019] [Figure 2] It is a front view of the multi-degree-of-freedom transmission device shown in FIG. 1.

[0020] [Figure 3] It is a perspective view of a first branch chain, a transmission assembly, and a second branch chain according to an embodiment of the present disclosure.

[0021] [Figure 4] It is a front view of the first branch chain, the transmission assembly, and the second branch chain shown in FIG. 3.

[0022] [Figure 5] It is a perspective view of a first linkage assembly according to an embodiment of the present disclosure.

[0023] [Figure 6] It is a perspective view of a first transmission shaft group according to an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0024] Next, in order to make the object, technical form, and advantages of the present disclosure clearer, the present disclosure will be described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described in this specification are only for explaining the present disclosure and are not intended to limit the present disclosure. The components of the embodiments of the invention generally described and illustrated in the drawings of this specification can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the protection scope of the present disclosure, but only shows preferred embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work also belong to the protection scope of the present disclosure.

[0026] In the following diagrams, the same symbols indicate the same items. Therefore, once an item is defined in one diagram, no further definition or explanation is needed in subsequent diagrams.

[0027] In the descriptions of the embodiments of this disclosure, terms such as "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," and "outside" are used for the convenience of describing this disclosure and to simplify the description, and do not express or suggest that the devices or elements being referred to must operate in a particular orientation. Rather, they indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, orientations and positional relationships in which the product is normally placed when in use, or orientations and positional relationships as normally understood by a person skilled in the art, and do not constitute a restrictive interpretation of this disclosure.

[0028] Furthermore, terms such as "first," "second," etc., are used merely to distinguish between explanations and should not be interpreted as explicitly or implicitly indicating relative importance.

[0029] The invention described herein will be explained below in conjunction with the attached drawings.

[0030] Referring to Figures 1-2, one embodiment provides a multi-degree-of-freedom transmission device configured to transmit force and torque in multiple directions. The multi-degree-of-freedom transmission device 1 includes a first platform 10, a second platform 20, a fixed platform 30, a plurality of first branch chains 40, a plurality of second branch chains 50, and a plurality of transmission assemblies 60.

[0031] The first platform 10 and the second platform 20 are movable platforms. One of the first platform 10 and the second platform 20 is a platform that receives external loads, i.e., a force input platform, and the other is a platform that outputs force, i.e., a force output platform. The fixed platform 30 is located between the first platform 10 and the second platform 20 and is fixedly installed, for example, by being fixed to a machining tool (not shown) or by being fixed to a bracket fixed to the ground.

[0032] Multiple first branch chains 40 are arranged in a sequence between the first platform 10 and the fixed platform 30. The multiple first branch chains 40, the first platform 10, and the fixed platform 30 constitute a first multi-degree-of-freedom parallel mechanism, enabling the first platform 10 to receive or output forces and torques in multiple directions.

[0033] Multiple second branch chains 50 are arranged between the second platform 20 and the fixed platform 30. The multiple second branch chains 50, the second platform 20, and the fixed platform 30 constitute a second multi-degree-of-freedom parallel mechanism, enabling the second platform 20 to receive or output multi-directional forces and torques. The fixed platform 30 may be a platform shared by the first multi-degree-of-freedom parallel mechanism and the second multi-degree-of-freedom parallel mechanism. Alternatively, the fixed platform 30 may be formed by connecting the stationary platform of the first multi-degree-of-freedom parallel mechanism to the stationary platform of the second multi-degree-of-freedom parallel mechanism. The structure of the second branch chains 50 is similar to that of the first branch chains 40, and the size of the second branch chains 50 is proportionally larger or smaller than that of the first branch chains 40. Specifically, the arrangement of multiple second branch chains 50 relative to the fixed platform 30 is basically the same as the arrangement of multiple first branch chains 40 relative to the fixed platform 30. The components of the second branch chain 50 and their connection order are essentially the same as those of the first branch chain 40, except that the size of the components of the second branch chain 50 is proportionally increased or decreased to that of the components of the first branch chain 40.

[0034] Multiple transmission assemblies 60 are coupled between multiple first branch chains 40 and multiple second branch chains 50, and are configured to couple the output end 80 of the first multi-degree-of-freedom parallel mechanism (see Figure 3) to the input end 90 of the second multi-degree-of-freedom parallel mechanism (see Figure 3). In one embodiment, the multiple transmission assemblies 60 couple the output end 80 of the first multi-degree-of-freedom parallel mechanism to the input end 90 of the second multi-degree-of-freedom parallel mechanism at a 1:1 speed ratio. In this embodiment, since the force, torque and / or displacement output by the output end 80 of the first multi-degree-of-freedom parallel mechanism is the same as the force, torque and / or displacement obtained by the input end 90 of the second multi-degree-of-freedom parallel mechanism, the rotation angle of the output end 80 of the first multi-degree-of-freedom parallel mechanism is the same as the rotation angle of the input end 90 of the second multi-degree-of-freedom parallel mechanism. When an external force received by the first platform 10 or the second platform 20, which acts as a force input platform, is transmitted to the second platform 20 or the first platform 10, which acts as a force output platform, the magnitude of the force and / or torque and displacement output by the force output platform in multiple spatial degrees of freedom can be adjusted by the size ratio of the first branch chain 40 and the second branch chain 50.

[0035] The multi-degree-of-freedom transmission device 1 includes two multi-degree-of-freedom parallel mechanisms located on both sides of the fixed platform 30. Therefore, any force and / or torque applied to the first platform 10 in any direction (in this case, the first platform 10 functions as a force input platform) is transmitted to the transmission assembly 60 via the first branch chain 40, to the second branch chain 50 via the transmission assembly 60, and finally to the second platform 20 via the second branch chain 50 (in this case, the second platform 20 functions as a force output platform). In this way, multi-degree-of-freedom forces and / or torques on the first platform 10 are transmitted to the execution terminals of the second platform 20, and multi-degree-of-freedom displacements on the first platform 10 are transmitted to the execution terminals of the second platform 20.

[0036] Since the first platform 10 and the second platform 20 are movable platforms and the fixed platform 30 is a fixed platform, the first branch chain 40 and the second branch chain 50 correspond to the force arms of levers on either side of the support point. Furthermore, since the size of the components of the second branch chain 50 expands or contracts in the same preset proportion to the size of the corresponding components of the first branch chain 40, when the force and / or torque received by the first platform 10 is transmitted through the multi-degree-of-freedom transmission device 1, the reduced or increased force and / or torque is obtained on the second platform 20, reducing or increasing the force and / or torque applied to the execution terminal of the second platform 20. In other embodiments, it should be noted that the second platform 20 can be configured to receive torque and the first platform 10 to output torque, i.e., the second platform 20 functions as a force input platform and the first platform 10 functions as a force output platform. If the device is configured to increase force and / or torque, pre-programmed operations that the execution terminal of the force output platform needs to perform, such as gripping a workpiece, can be achieved by applying small forces and / or torque to the force input platform, thus making it easier to grip the workpiece. If the device is configured to decrease force and / or torque, it is possible to prevent the object being worked on by the execution terminal of the force output platform from being damaged by large forces and / or torque.

[0037] In the embodiment shown in Figure 1, the size of each component of the second branch chain 50 is reduced in a 2:1 ratio to the size of the corresponding component of the first branch chain 40. When the first platform 10 is used as a force input platform and the second platform 20 is used as a force output platform, it is possible to obtain increased force and / or torque and decreased displacement on the second platform 20. In this way, the function of increasing output force / torque and decreasing displacement over multiple spatial degrees of freedom from the first platform 10 to the second platform 20 is realized. When the second platform 20 is used as a force input platform and the first platform 10 is used as a force output platform, it is possible to obtain decreased force and / or torque and increased displacement on the first platform 10. In this way, the function of decreasing output force / torque and increasing displacement over multiple spatial degrees of freedom from the second platform 20 to the first platform 10 is realized.

[0038] In one embodiment, as shown in Figures 1 and 4, the fixed platform 30 is formed in a roughly Y shape. The fixed platform 30 includes a fixed plate 31, three first connecting frames 32, and three second connecting frames 33. The fixed plate 31 includes a central portion 311 and three positioning portions 312 connected to the central portion 311. The three positioning portions 312 extend outward from the central portion 311 at equal intervals, and the angle between two adjacent positioning portions 312 is approximately 120°. A first through hole 313 is provided at the end of each positioning portion 312 away from the central portion 311. One of the three first connecting frames 32 is fixed to the end of the three positioning portions 312 away from the central portion 311. In this embodiment, the three first connecting frames 32 are located on the side of the fixed plate 31 facing the first platform 10. The first connecting frame 32 includes two first fixing pieces 321 fixed perpendicularly to the fixing plate 31, and a first pressure-receiving piece 322 perpendicularly connected between the two first fixing pieces 321. The first pressure-receiving piece 322 is provided with a first positioning hole 323 corresponding to a first through hole 313, and a portion of the transmission assembly 60 is rotatably housed in the first through hole 313 and the first positioning hole 323. Three second connecting frames 33 are fixed to the ends of the three positioning sections 312 adjacent to the central section 311, and are located on the side of the fixing plate 31 facing the second platform 20. The structure of the second connecting frame 33 is similar to that of the first connecting frame 32, and includes two second fixing pieces 331 fixed perpendicularly to the fixing plate 31, and a second pressure-receiving piece 332 perpendicularly connected between the two second fixing pieces 331. The second pressure-receiving piece 332 is provided with a second positioning hole 333 for rotatably accommodating the other parts of the transmission assembly 60.

[0039] In some embodiments, there are three first branch chains 40 and three second branch chains 50. The three first branch chains 40 are evenly distributed between the first platform 10 and the three first connecting frames 32 and connected to one end of the three transmission assemblies 60 so that movement between the transmission assemblies 60 and the first branch chains 40 is transmitted. In some embodiments, the three first branch chains 40, the first platform 10, and the fixed platform 30 constitute a first 3-RRRS parallel mechanism (RRRS stands for motion pairs consisting of three rotational pairs (R) and one spherical pair (S)). The three second branch chains 50 are evenly distributed between the second platform 20 and the three second connecting frames 33 and connected to the other end of the transmission assemblies 60 so that movement between the transmission assemblies 60 and the second branch chains 50 can be transmitted. Three second branch chains 50, a second platform 20, and a fixed platform 30 constitute a second 3-RRRS parallel mechanism. A definition of a 3-RRRS parallel mechanism can be found by referring to prior art such as Patent Documents 1, 2, and 3, the entirety of which is incorporated into this disclosure. The movable platforms of the 3-RRRS parallel mechanism have six spatial degrees of freedom, and since the two movable platforms of the two 3-RRRS parallel mechanisms are used as the input platform and output platform of the multi-degree-of-freedom transmission device 1, movement of the six spatial degrees of freedom can be transmitted from the first platform 10 to the second platform 20. It should be understood that the first branch chains 40 and the second branch chains 50 described above are merely one embodiment of a 6-degree-of-freedom parallel mechanism. In other embodiments, the structure of the first branch chains 40 and the second branch chains 50 may be that of other 6-degree-of-freedom parallel mechanisms. The first branch chain 40 and the second branch chain 50 may be other multi-degree-of-freedom parallel mechanisms, such as a three-degree-of-freedom parallel mechanism capable of achieving three spatial degrees of freedom movement between the first platform 10 and the second platform 20.

[0040] As shown in Figure 1, in some embodiments, the first branching chain 40 includes a first ball pair 41, a first rotational pair 44, a second rotational pair 45, and a third rotational pair 46, which are connected in sequence. The first ball pair 41 is connected to the first platform 10, and the third rotational pair 46 is connected to the fixed platform 30. The first rotational pair 44 and the second rotational pair 45 are the output ends 80 of the first multi-degree-of-freedom parallel mechanism and are connected to one end of the transmission assembly 60. The first rotational pair 44 and the second rotational pair 45 are connected to the first ball pair 41, and the rotation axis of the first rotational pair 44 is parallel to or coincides with the rotation axis of the second rotational pair 45. The third rotational pair 46 is rotatably connected to the first rotational pair 44 and the second rotational pair 45, and the axis of rotation of the third rotational pair 46 is perpendicular to the axes of rotation of the first rotational pair 44 and the second rotational pair 45. When the first platform 10 is subjected to force and / or torque as a force input platform, the force and / or torque is transmitted to the first rotational pair 44 and the second rotational pair 45 via the first ball pair 41, then to the transmission assembly 60 connected to the first rotational pair 44 and the second rotational pair 45, and further to the second platform 20 via the transmission assembly 60 and the second branch chain 50. When the movement is transmitted to the transmission assembly 60 by the first rotation pair 44 and the second rotation pair 45, the rotation of the first rotation pair 44 and the second rotation pair 45 relative to the fixed platform 30 can be achieved via the third rotation pair 46, thereby avoiding distortion of the first rotation pair 44 and the second rotation pair 45 during rotation.

[0041] Specifically, referring to Figure 5, the first ball pair 41 includes a cross-axis universal joint 411, a first rotating rod 412 connected to one end of the cross-axis universal joint 411, a second rotating rod 413 connected to the other end of the cross-axis universal joint 411, and a first linkage assembly 414. The first rotating rod 412 is rotatably connected to the first platform 10, and the second rotating rod 413 is rotatably connected to the first linkage assembly 414. In this embodiment, the first platform 10 is roughly circular, and three fixed blocks 417 are fixed to the edge of the first platform 10. Each fixed block 417 is fitted with a first bearing 418, and one end of the first rotating rod 412 away from the second rotating rod 413 is rotatably housed in the first bearing 418, thereby realizing a rotational connection between the first rotating rod 412 and the first platform 10. The axis of rotation of the first rotating rod 412 is the central axis of the first rotating rod 412. The first linkage assembly 414 includes two first connecting rods 415. A second bearing 425 is fixed between the two first connecting rods 421, and the second rotating rod 413 is rotatably connected to a second bearing 416, thereby realizing a rotational connection between the second rotating rod 413 and the first linkage assembly 42. The axis of rotation of the second rotating rod 413 is the central axis of the second rotating rod 413.

[0042] Referring to Figure 3, the first rotational pair 44 includes a second connecting rod 441, a third connecting rod 442, and a first rotating shaft 443. One end of the second connecting rod 441 is rotatably connected perpendicularly to the two first connecting rods 415 of the first linkage assembly 414, the other end of the second connecting rod 441 is fixed perpendicularly to one end of the third connecting rod 442, and the first rotating shaft 443 is fixedly connected to the end of the third connecting rod 442 away from the second connecting rod 441 and rotatably connected to the third rotational pair 46. The first rotating shaft 443 and the second connecting rod 441 are located on the same side of the third connecting rod 442.

[0043] The second rotational pair 45 includes a fourth linkage rod 451, a fifth linkage rod 452, a sixth linkage rod 453, and a second rotational shaft 454. One end of the fourth linkage rod 451 is rotatably connected perpendicularly to two first linkage rods 415 of the first linkage assembly 414 and is positioned further away from the second rotational rod 413 than the second linkage rod 441. The other end of the fourth linkage rod 451 is fixed perpendicularly to one end of the fifth linkage rod 452, and the other end of the fifth linkage rod 452 is rotatably connected to one end of the sixth linkage rod 453. The sixth linkage rod 453 and the fourth linkage rod 451 are located on the same side of the fifth linkage rod 452. The second rotating shaft 454 is fixedly connected to the other end of the sixth connecting rod 453 and is rotatably connected to the third rotating pair 46.

[0044] The third rotational pair 46 includes a first bracket 461 and a third rotational shaft 462. The first rotational shaft 443 and the second rotational shaft 454 are rotatably connected to the first bracket 461. The third rotational shaft 462 is connected to the first bracket 461 and is rotatably connected to the fixed platform 30, thereby achieving rotational connection between the third rotational pair 46 and the fixed platform 30.

[0045] Specifically, referring to Figure 1, the first bracket 461 includes two parallel first vertical plates 463, a first horizontal plate 464 perpendicularly connected between the two first vertical plates 463, and a third rotating shaft 462 connected to the first horizontal plate 464. The third connecting rod 442 and the sixth connecting rod 453 are located outside the two first vertical plates 463. Each first vertical plate 463 is provided with a first transverse hole 465 parallel to the fixed platform 30, and the first rotating shaft 443 and the second rotating shaft 454 each rotatably extend through the first transverse hole 465, thereby realizing rotational connections between the first rotating pair 44, the second rotating pair 45, and the third rotating pair 46. The first horizontal plate 464 is provided with a first vertical hole 466 aligned with the first positioning hole 323, and a portion of the transmission assembly 60 is rotatably housed in the first through hole 313, the first positioning hole 323, and the first vertical hole 466. In one embodiment, the third rotating shaft 462 is provided with a limiting hole (not shown) coaxial with the first positioning hole 323 and the first vertical hole 466, and the transmission assembly 60 is rotatably housed in the first through hole 313, the first positioning hole 323, the first vertical hole 466, and the limiting hole.

[0046] The second branch chain 50 includes, in order, a second ball pair 51, a fourth rotation pair 56, a fifth rotation pair 54, and a sixth rotation pair 55. The second ball pair 51 is connected to the second platform 20, the fourth rotation pair 56 is connected to the fixed platform 30, and the fifth rotation pair 54 and the sixth rotation pair 55 are the input ends 90 of the second multi-degree-of-freedom parallel mechanism and are connected to the other ends of the transmission assembly 60. The structure and connection relationships of the second ball pair 51, the fourth rotation pair 56, the fifth rotation pair 54, and the sixth rotation pair 55 are the same as those of the first ball pair 41, the first rotation pair 44, and the second rotation pair, and will not be repeated here. The sizes of the second ball pair 51, the fourth rotation pair 56, the fifth rotation pair 54, and the sixth rotation pair 55 are proportionally larger or smaller than those of the first ball pair 41, the first rotation pair 44, the second rotation pair 45, and the third rotation pair 46. The fourth rotation pair 56 is rotatably connected to the second pressure receiving piece 332 of the fixed platform 30. The fifth rotation pair 54 and the sixth rotation pair 55 are rotatably connected to the fourth rotation pair, and the rotation axis of the fifth rotation pair 54 is parallel to or coincides with the rotation axis of the sixth rotation pair 55. The rotation axis of the fourth rotation pair 56 is perpendicular to the rotation axes of the fifth rotation pair 54 and the sixth rotation pair 55. When the torque received by the first rotation pair 44 and the second rotation pair 45 is transmitted to the transmission assembly 60, the torque can be transmitted through the transmission assembly 60 to the fifth rotation pair 54 and the sixth rotation pair 55, and then to the second platform 20 via the second ball pair 51. When the torque received by the first rotation pair 44 and the second rotation pair 45 is transmitted through the transmission assembly 60 to the fifth rotation pair 54 and the sixth rotation pair 55, the fifth rotation pair 54 and the sixth rotation pair 55 can rotate relative to the fixed platform 30 via the fourth rotation pair 56, thereby avoiding distortion of the fifth rotation pair 54 and the sixth rotation pair 55.

[0047] The first multi-degree-of-freedom parallel mechanism and the second multi-degree-of-freedom parallel mechanism are not limited to the 3-RRRS parallel mechanism described above, but may be other parallel mechanisms capable of realizing a multi-degree-of-freedom parallel mechanism, such as a 3-URS parallel mechanism (URS meaning a pair of motions in a branching chain consisting of one universal pair (U), one rotational pair (R), and one spherical pair (S)). For example, if both the first multi-degree-of-freedom parallel mechanism and the second multi-degree-of-freedom parallel mechanism are 3-degree-of-freedom parallel mechanisms, the multi-degree-of-freedom transmission device 1 can transmit motion of three spatial degrees of freedom.

[0048] Referring to Figures 2, 3, and 6, the transmission assembly 60 includes a first bevel gear 61 connected to a first rotational pair 44, a second bevel gear 62 connected to a second rotational pair 45, a third bevel gear 63 connected to a fifth rotational pair 54, a fourth bevel gear 64 connected to a sixth rotational pair 55, and a linkage assembly 65. The diameter of the pitch circle of the first bevel gear 61 is smaller than the diameter of the pitch circle of the second bevel gear 62, and the diameter of the pitch circle of the third bevel gear 63 is smaller than the diameter of the pitch circle of the fourth bevel gear 64. The linkage assembly 65 is configured to transmit the rotation of the first bevel gear 61 to the third bevel gear 63 and the rotation of the second bevel gear 62 to the fourth bevel gear 64.

[0049] The linkage assembly 65 includes a first group of transmission shafts 66, a second group of transmission shafts 67, and a third group of transmission shafts 68, all rotatably connected to the fixed platform 30. The first group of transmission shafts 66 is rotatably housed in a first through hole 313, a first positioning hole 323, and a first vertical hole 466, with both ends of the first group of transmission shafts 66 located on opposite sides of the fixed platform 30. The second group of transmission shafts 67 and the third group of transmission shafts 68 are located on one side of the fixed platform 30, and the first group of transmission shafts 66 and the third group of transmission shafts 68 are perpendicularly connected to both ends of the second group of transmission shafts 67. Multiple support plates 34 are fixed to the side of the fixed platform 30 where the second group of transmission shafts 67 and the third group of transmission shafts 68 are located. Each support plate 34 is provided with a coaxial group of support holes 35, the central axis of the support hole group 35 is parallel to the fixed platform 30, and each second group of transmission shafts 67 is rotatably housed in the support hole group 35. The third group of transmission shafts 68 is rotatably housed in a hole corresponding to the second positioning hole 333 and the first vertical hole 466 of the fourth rotation pair 56.

[0050] The first drive shaft group 66, the second drive shaft group 67, and the third drive shaft group 68 each include a first shaft 69 and a second shaft 70 rotatably housed in the first shaft 69. A fifth bevel gear 71 is fitted to each end of the second shaft 70, and a sixth bevel gear 72 is fitted to each end of the first shaft 69. The fifth bevel gear 71 and the sixth bevel gear 72 located at the ends of the first drive shaft group 66 adjacent to the first branch chain 40 mesh with the first bevel gear 61 and the second bevel gear 62, respectively. The fifth bevel gear 71 and the sixth bevel gear 72 located at the ends of the third drive shaft group 68 adjacent to the second branch chain 40 mesh with the third bevel gear 63 and the fourth bevel gear 64, respectively. The fifth bevel gear 71 and the sixth bevel gear 72, located at both ends of the second drive shaft group 67, mesh with the fifth bevel gear 71 and the sixth bevel gear 72 located at the ends of the first drive shaft group 66 away from the first branch chain 40, and with the fifth bevel gear 71 and the sixth bevel gear 72 located at the ends of the third drive shaft group 68 away from the second branch chain 50, respectively. In this way, the movement between the first bevel gear 61, the second bevel gear 62, the third bevel gear 63, and the fourth bevel gear 64 is transmitted via the fifth bevel gear 71 located at both ends of the second shaft 70 and the sixth bevel gear 72 located at both ends of the first shaft 69.

[0051] In one embodiment, the structure and size of the first bevel gear 61, the third bevel gear 63, and the fifth bevel gear 71 are the same, and the structure and size of the second bevel gear 62, the fourth bevel gear 64, and the sixth bevel gear are the same, so the transmission assembly 60 transmits the torque from the output end 80 (first rotational pair 44 and second rotational pair 45) of the first multi-degree-of-freedom parallel mechanism to the input end 90 (fifth rotational pair 54 and sixth rotational pair 55) of the second multi-degree-of-freedom parallel mechanism at a speed ratio of 1:1.

[0052] The transmission assembly 66 is not limited to the bevel gear transmission structure described above, but may be any other transmission mechanism capable of transmitting motion between two multi-degree-of-freedom parallel mechanisms, such as a worm gear transmission structure.

[0053] This disclosure further provides a robot including the multi-degree-of-freedom transmission device 1 described above. A first platform 10 is a force input platform used to receive a loaded force and / or torque, and a second platform 20 is a force output platform configured to process or transfer products via execution terminals on the force output platform.

[0054] According to the multi-degree-of-freedom transmission device 1 and robot, on the one hand, when the platform connected to the larger of the first branch chain 40 and the second branch chain 50 functions as a force input platform, the force and / or torque received by the force input platform is transmitted to the force output platform connected to the smaller of the first branch chain 40 and the second branch chain 50 via two multi-degree-of-freedom parallel mechanisms located on both sides of the fixed platform 30. This increases the multi-degree-of-freedom force and / or torque output to the platform connected to the smaller branch chain and decreases the displacement output to the platform. On the other hand, when the platform connected to the smaller of the first branch chain 40 and the second branch chain 50 functions as a force input platform, the force and / or torque received by the force input platform is transmitted to the force output platform connected to the larger of the first branch chain 40 and the second branch chain 50 via two multi-degree-of-freedom parallel mechanisms located on both sides of the fixed platform 30. This increases the multi-degree-of-freedom force and / or torque output to the platform connected to the larger branch chain and decreases the displacement output to the platform. In this way, the output multi-degree-of-freedom force / torque or multi-degree-of-freedom displacement can be increased or decreased as needed.

[0055] The above description is merely a specific embodiment of the present invention and does not limit the scope of protection of the present invention. All modifications and substitutions that are easily conceivable by those skilled in the art within the scope of the art disclosed herein shall fall within the scope of protection of the present invention.

[0056] The above embodiments do not limit the scope of protection of the present invention. Modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments are also included within the scope of protection of the present invention.

Claims

1. A multi-degree-of-freedom transmission device, It includes a first platform, a second platform, a fixed platform installed between the first platform and the second platform, a plurality of first branch chains, a plurality of second branch chains, and a plurality of transmission assemblies. The plurality of first branch chains are arranged between the first platform and the fixed platform, and the plurality of first branch chains, the first platform, and the fixed platform constitute a first multi-degree-of-freedom parallel mechanism. The plurality of second branch chains are arranged between the second platform and the fixed platform, and the plurality of second branch chains, the second platform, and the fixed platform constitute a second multi-degree-of-freedom parallel mechanism, the structure of the second branch chain is similar to the structure of the first branch chain, and the size of the second branch chain is proportionally increased or decreased to the size of the first branch chain. The plurality of transmission assemblies are coupled between the plurality of first branch chains and the plurality of second branch chains, and are configured to couple the output terminal of the first multi-degree-of-freedom parallel mechanism to the input terminal of the second multi-degree-of-freedom parallel mechanism. The plurality of first branch chains include three first branch chains, the plurality of second branch chains include three second branch chains, the three first branch chains, the first platform, and the fixed platform constitute a first 3-RRRS parallel mechanism, the three second branch chains, the second platform, and the fixed platform constitute a second 3-RRRS parallel mechanism. Each of the plurality of first branching chains includes, in order, a first ball pair, a first rotational pair, a second rotational pair, and a third rotational pair. The first ball pair is connected to the first platform, the third rotation pair is connected to the fixed platform, and the first rotation pair and the second rotation pair are the output terminals of the first multi-degree-of-freedom parallel mechanism. Each of the second branching chains includes, in order, a second ball pair, a fourth rotational pair, a fifth rotational pair, and a sixth rotational pair. The second ball pair is connected to the second platform, the fourth rotation pair is connected to the fixed platform, and the fifth and sixth rotation pairs are the input terminals of the second multi-degree-of-freedom parallel mechanism. When motion is transmitted to the transmission assembly by the first and second pairs of rotations, the rotation of the first and second pairs of rotations relative to the fixed platform is achieved via the third pair of rotations, thereby avoiding distortion of the first and second pairs of rotations during rotation. A multi-degree-of-freedom transmission device characterized in that, when the torque received by the first and second rotational pairs is transmitted to the fifth and sixth rotational pairs via the transmission assembly, the relative rotation of the fifth and sixth rotational pairs with respect to the fixed platform is achieved via the fourth rotational pair, thereby avoiding distortion of the fifth and sixth rotational pairs.

2. The multi-degree-of-freedom transmission device according to claim 1, characterized in that the plurality of transmission assemblies connect the output terminal of the first multi-degree-of-freedom parallel mechanism to the input terminal of the second multi-degree-of-freedom parallel mechanism at a speed ratio of 1:

1.

3. Any of the plurality of transmission assemblies includes a first bevel gear connected to the first pair of rotations, a second bevel gear connected to the second pair of rotations, a third bevel gear connected to the fifth pair of rotations, a fourth bevel gear connected to the sixth pair of rotations, and a linkage assembly. The multi-degree-of-freedom transmission device according to claim 1, characterized in that the linkage assembly is configured to transmit the rotation of the first bevel gear to the third bevel gear and the rotation of the second bevel gear to the fourth bevel gear.

4. The linkage assembly includes a first group of transmission shafts, a second group of transmission shafts, and a third group of transmission shafts, which are rotatably connected to the fixed platform. Each of the first group of transmission shafts, the second group of transmission shafts, and the third group of transmission shafts includes a first shaft and a second shaft rotatably housed in the first shaft. The ends of the first transmission shaft group are located on both sides of the fixed platform, the second and third transmission shaft groups are located on one side of the fixed platform, and the first and third transmission shaft groups are connected perpendicularly to both ends of the second transmission shaft group. Each of the two second shafts is fitted with a fifth bevel gear, and each of the two first shafts is fitted with a sixth bevel gear. The fifth bevel gear and the sixth bevel gear, located at the end of the first transmission shaft group adjacent to the first branch chain, mesh with the first bevel gear and the second bevel gear, respectively. The fifth and sixth bevel gears, located at the ends of the third drive shaft group adjacent to the second branch chain, mesh with the third and fourth bevel gears, respectively. The multi-degree-of-freedom transmission device according to claim 3, characterized in that the fifth bevel gear and the sixth bevel gear located at both ends of the second transmission shaft group mesh with the fifth bevel gear and the sixth bevel gear located at the end of the first transmission shaft group away from the first branch chain, and mesh with the fifth bevel gear and the sixth bevel gear located at the end of the third transmission shaft group away from the second branch chain.

5. The multi-degree-of-freedom transmission device according to claim 4, wherein the fixed platform further includes a plurality of support plates fixed to the side surface of the fixed platform on which the second group of transmission shafts and the third group of transmission shafts are located, each of the plurality of support plates having a group of support holes, and each of the second group of transmission shafts is rotatably housed in the group of support holes.

6. The multi-degree-of-freedom transmission device according to claim 1, wherein the fixed platform includes a fixed plate, three first connecting frames, and three second connecting frames, the fixed plate includes a central portion and three positioning portions arranged at equal intervals around the central portion, the three first connecting frames are each fixed to the ends of the three positioning portions away from the central portion and are located on the side of the fixed plate facing the first platform, and the three second connecting frames are each fixed to the ends of the three positioning portions adjacent to the central portion and are located on the side of the fixed plate facing the second platform.

7. A first through hole is provided at the end of each positioning portion away from the central portion, and the first connecting frame includes two first fixing pieces fixed perpendicularly to the fixing plate and a first pressure receiving piece perpendicularly connected between the two first fixing pieces, the first pressure receiving piece having a first positioning hole corresponding to the first through hole, and a part of the transmission assembly is rotatably housed in the first through hole and the first positioning hole, as described in claim 6.

8. It is a robot, A robot comprising a multi-degree-of-freedom transmission device according to any one of claims 1 to 7, wherein the first platform is a force input platform and the second platform is a force output platform.

Images