Robots and their transmission mechanisms

The described transmission mechanism for SCARA robots addresses precision and torque limitations by employing coaxial rotating members and eccentric crankshafts with connecting rods, enhancing performance and reducing size and cost.

JP7805464B2Active Publication Date: 2026-01-23MIDEA GRP (SHANGHAI) CO LTD +1
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Patent Information

Application Number
JP2024539558
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2021-12-31
Filing Date
2022-11-30
Publication Date
2026-01-23
Estimated Expiration
2042-11-30

AI Technical Summary

Technical Problem

Conventional SCARA robots face issues with insufficient transmission precision, torque, and rigidity due to the use of harmonic or RV reducers, which are expensive and increase the size and weight of the machine, affecting overall performance.

Method used

A transmission mechanism with two sets of rotating members, each comprising a first and second rotating member coaxially arranged, connected via eccentric crankshafts and connecting rods, allowing for continuous power transmission without interference and improving precision and torque.

Benefits of technology

The mechanism enhances transmission precision, increases transmittable torque, and improves overall rigidity while reducing the size and cost of the robot by using a parallel drive structure.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

A robot (100) and a transmission mechanism (50). The transmission mechanism (50) includes two sets of rotating members (51), two crankshafts (52), and two first connecting rods (53). Each set of rotating members (51) includes a first rotating member (511) and a second rotating member (512) that are coaxially arranged. Each of the two crankshafts (52) includes a connecting arm (520), and a first shaft body (521) and a second shaft body (522) that are arranged on opposite sides of the connecting arm (520). The first shaft body (521) and the second shaft body (522) are arranged on opposite sides of the connecting arm (520). The axis of the first connecting rod (53) is connected to the first rotating member (511) and is installed eccentrically with respect to the first rotating member (511), the second connecting rod (522) is connected to the second rotating member (512) and is installed eccentrically with respect to the second rotating member (512), and one end of each of the two first connecting rods (53) is rotatably connected to the two first connecting rods (521), and the other end of each of the two first connecting rods (53) is rotatably connected to the two second connecting rods (522).
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Description

[Technical Field]

[0001] The present application relates to the field of robotics, and more particularly to robots and their power transmission mechanisms. [Background technology]

[0002] Currently, conventional SCARA robots generally use a motor and a reducer to form a single-axis and two-axis drive unit, and this method generally uses a harmonic reducer or RV reducer, which is expensive and has limited precision. Furthermore, the conventional overall machine layout uses a two-axis drive unit directly connected to the small arm, which requires a larger output torque for one axis, requiring a larger motor or reducer, which increases the size and weight of the entire machine and affects the overall machine performance.

[0003] Therefore, it has been proposed to move the two-axis drive unit backward and use a timing belt to drive the small arm, which can reduce the weight and size of the entire machine. However, the current timing belt transmission does not have sufficient transmission precision, large transmission torque, or high rigidity, which affects the performance of the entire machine. Summary of the Invention [Problem to be solved by the invention]

[0004] The present application mainly provides a robot and its transmission mechanism, which solves the problems of the conventional transmission mechanism, such as insufficient transmission precision, insufficient transmission torque, and insufficient rigidity. [Means for solving the problem]

[0005] In order to solve the above technical problems, the first technical solution adopted by the present application provides a transmission mechanism, the transmission mechanism includes two sets of rotating members, two crankshafts, and two first connecting rods, the rotating members of each set include a first rotating member and a second rotating member that are coaxially arranged, the two crankshafts each include a connecting arm, and a first shaft and a second shaft that are arranged on opposite sides of the connecting arm, the axis of the first shaft and the axis of the second shaft are not on the same line, the first shaft is connected to the first rotating member and is eccentric with respect to the first rotating member the second shaft is connected to the second rotating member and is installed eccentrically relative to the second rotating member, one end of each of the two first connecting rods is rotatably connected to the two first shafts, and the other end of each of the two first connecting rods is rotatably connected to the two second shafts; when the first rotating member or the second rotating member of one set of rotating members rotates, the crankshaft connected thereto is rotated and driven, and power is transmitted between the two crankshafts via the two first connecting rods, further rotating and driving another set of rotating members.

[0006] In some embodiments, the axis of the first shaft and the axis of the second shaft are parallel.

[0007] In some embodiments, the axis of the first rotating member is taken as a reference line, and the angle at which the axis of the first shaft deviates from the axis of the second shaft is greater than 0° and less than 180°.

[0008] In some embodiments, the connecting arm is rod-shaped, and the first shaft and the second shaft are disposed at opposite ends of the connecting arm.

[0009] In some embodiments, the crankshaft further includes at least one third shaft, the axis of which is parallel to the axis of the first shaft, the connecting arm includes at least two sub-arms, and two adjacent sub-arms are fixedly connected via the third shaft, the transmission mechanism further includes second connecting rods, the number of which is the same as the number of the third shafts, and both ends of the second connecting rod are rotatably connected to the two corresponding third shafts of the two crankshafts.

[0010] In some embodiments, the axis of the first rotating member is used as a reference line, and the angle by which the axis of the first shaft and the axis of the second shaft deviate from the axis of the adjacent third shaft is greater than 0° and less than 180°.

[0011] In some embodiments, the axis of the first rotating member is taken as a reference line, and the offset angle between the axes of two adjacent third shafts is greater than 0° and less than 180°.

[0012] In some embodiments, two adjacent sub-arms are arranged offset from one another.

[0013] In some embodiments, the first connecting rod and the second connecting rod have the same length.

[0014] In some embodiments, the transmission mechanism further includes a first bearing and a second bearing, the first bearing being arranged between the first shaft body and one of the first connecting rods corresponding to the first shaft body, and the second bearing being arranged between the second shaft body and the other of the first connecting rods corresponding to the second shaft body.

[0015] In some embodiments, the first rotating member is provided with a first positioning portion, the first positioning portion is arranged eccentrically relative to the first rotating member, and one end of the first shaft remote from the connecting arm is aligned and connected to the first positioning portion, and the second rotating member is provided with a second positioning portion, the second positioning portion is arranged eccentrically relative to the second rotating member, and one end of the second shaft remote from the connecting arm is aligned and connected to the second positioning portion.

[0016] In some embodiments, the first positioning portion and the second positioning portion are both positioning grooves, the first shaft body and the second shaft body both include a first shaft step portion and a second shaft step portion arranged in a stepped manner, the shaft diameter of the first shaft step portion is larger than the shaft diameter of the second shaft step portion, the first bearing or the second bearing is fitted into the first shaft step portion, the second shaft step portion is inserted into the positioning groove, and the step surface between the first shaft step portion and the second shaft step portion is fastened to the end face of the positioning groove.

[0017] In some embodiments, both the first shaft body and the second shaft body are provided with a first connecting hole and a first positioning hole, the plurality of first positioning holes are arranged surrounding the first connecting hole, the bottom wall of the positioning groove is provided with a second connecting hole and a second positioning hole, the plurality of second positioning holes are arranged surrounding the second connecting hole, the first positioning hole and the second positioning hole are connected via a positioning member, and the first connection hole and the second connection hole are connected via a fastening member.

[0018] In some embodiments, the first shaft and the second shaft are further provided with weight-reducing grooves, the connecting arm is provided with relief holes corresponding to the weight-reducing grooves, and the first connecting hole and the first positioning hole are located on the bottom wall of the weight-reducing grooves.

[0019] In order to solve the above technical problems, another technical solution adopted by the present application provides a robot, the robot including: a main transmission arm, the above-mentioned transmission mechanism, an auxiliary transmission arm, an auxiliary drive mechanism, and a main drive mechanism, the transmission mechanism is disposed within the main transmission arm, the auxiliary transmission arm is rotatably disposed at one end of the main transmission arm and is coaxially fixed to one first rotating member of the transmission mechanism, the auxiliary drive mechanism is coaxially fixed to the other first rotating member of the transmission mechanism so as to rotationally drive the auxiliary transmission arm, the main drive mechanism is connected to the main transmission arm and is used to rotationally drive the main transmission arm, and the main drive mechanism and the auxiliary drive mechanism are both installed at one end of the main transmission arm away from the auxiliary transmission arm and are respectively arranged on two opposite sides of the main transmission arm.

[0020] The beneficial effects of this application are as follows. Unlike the prior art, this application discloses a robot and its transmission mechanism. By arranging two sets of rotating members, each set of rotating members includes a first rotating member and a second rotating member arranged coaxially, and the first rotating member is further used to connect external structural components, thereby achieving power transmission. An eccentric crankshaft is provided between the first rotating member and the second rotating member. Two first connecting rods are rotatably connected to the two crankshafts, and the two first connecting rods are in different rotational planes, do not interfere with each other, and can smoothly pass each other's dead center positions by interlocking with each other, forming continuous full-circle transmission. That is, power transmission between the two sets of rotating members can be achieved through the crankshafts and the first connecting rods, and the double-connecting rod transmission structure further improves transmission precision, increases transmittable torque, and improves overall rigidity. [Brief explanation of the drawings]

[0021] In order to more clearly describe the technical solutions in the embodiments of the present application or the technical solutions in the prior art, the following will briefly describe the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. Those skilled in the art can obtain other drawings from these drawings without any creative efforts. [Figure 1] 1 is a structural schematic diagram of an embodiment of a robot provided by the present application; [Figure 2] 2 is a structural schematic diagram of a main transmission arm and a transmission mechanism in the robot shown in FIG. 1. [Figure 3] FIG. 3 is an exploded structural schematic view of the main transmission arm and the transmission mechanism shown in FIG. 2. [Figure 4] FIG. 3 is a structural schematic diagram of the transmission mechanism shown in FIG. 2. [Figure 5] 5 is a schematic diagram showing an assembly structure of a crankshaft and a first connecting rod of the power transmission mechanism shown in FIG. 4. FIG. [Figure 6] FIG. 6 is a structural schematic diagram of a crankshaft of the power transmission mechanism shown in FIG. 5. [Figure 7] 5 is a schematic top view of a set of rotating members and a crankshaft of the power transmission mechanism shown in FIG. 4. FIG. [Figure 8] 5 is a structural schematic diagram showing an assembly structure of a crankshaft, a first connecting rod, and a second connecting rod in the power transmission mechanism shown in FIG. 4. FIG. [Figure 9] FIG. 9 is a structural schematic diagram of a crankshaft in the power transmission mechanism shown in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the technical solutions of the embodiments of the present application will be clearly and completely described with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of them. Based on the embodiments of the present application, all other embodiments that a person skilled in the art can obtain without inventive efforts fall within the scope of protection of the present application.

[0023] The terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or the number of technical features depicted. Thus, features defined as "first," "second," and "third" can explicitly or implicitly include at least one of these features. In the description of this application, "plurality" means at least two, e.g., two, three, etc., unless otherwise clearly and specifically defined. Additionally, the terms "comprise," "have," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not limited to the recited steps or units, but may optionally include additional steps or units not recited, or may optionally include other steps or units inherent in the process, method, product, or apparatus.

[0024] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described with reference to the embodiment may be included in at least one embodiment of the present application. The appearance of such a combination in various places in the specification does not necessarily refer to the same embodiment, nor does it mean that the embodiments are mutually exclusive, independent, or alternative embodiments. As will be understood by those skilled in the art, both explicitly and implicitly, the embodiments described herein can be combined with other embodiments.

[0025] The present application provides a robot 100. As shown in Figures 1 and 2, Figure 1 is a structural schematic diagram of one embodiment of the robot provided by the present application, and Figure 2 is a structural schematic diagram of the main transmission arm and transmission mechanism in the robot shown in Figure 1.

[0026] The robot 100 includes a main driving mechanism 10, a sub-driving mechanism 20, a sub-transmission arm 30, a main transmission arm 40, and a transmission mechanism 50. The transmission mechanism 50 is installed within the main transmission arm 40, the sub-transmission arm 30 is rotatably installed at one end of the main transmission arm 40, and the sub-transmission arm 30 is transmissionably connected to one end of the transmission mechanism 50, and the sub-driving mechanism 20 is transmissionably connected to the other end of the transmission mechanism 50, so that the sub-driving mechanism 20 rotates the sub-transmission arm 30 relative to the main transmission arm 40 via the transmission mechanism 50, and the main driving mechanism 10 is connected to one end of the main transmission arm 40 remote from the sub-transmission arm 30, so that the main driving mechanism 10 rotates the main transmission arm 40.

[0027] Here, the main driving mechanism 10 and the sub-driving mechanism 20 are both installed at one end of the main transmission arm 40 remote from the sub-transmission arm 30, and are arranged on opposite sides of the main transmission arm 40, respectively.

[0028] In conventional robots, the main driving mechanism 10 and the sub-driving mechanism 20 are generally connected to both ends of the main transmission arm 40, respectively, and there is no need to install any type of transmission mechanism 50 within the main transmission arm 40. The sub-driving mechanism 20 is installed relatively close to the sub-transmission arm 30, and can directly rotate and drive the sub-transmission arm 30.

[0029] Compared to the above embodiment in which the sub-driving mechanism 20 is installed relatively close to the sub-transmission arm 30, in this embodiment, the main driving mechanism 10 and the sub-driving mechanism 20 are both arranged at one end of the main transmission arm 40, away from the sub-transmission arm 30, and are arranged on opposite sides of the main transmission arm 40, respectively. This allows the sub-driving mechanism 20 to be installed at the rear, effectively reducing the moment of inertia on one side of the sub-transmission arm 30 and significantly reducing the required rotational torque provided by the main driving mechanism 10. This is advantageous in that it uses a low-power main driving mechanism 10 to drive the main transmission arm 40, and effectively reduces the cost of the robot 100.

[0030] In other words, compared with the conventional serial structure of the main drive mechanism 10 and the auxiliary drive mechanism 20, in this embodiment, the main drive mechanism 10 and the auxiliary drive mechanism 20 adopt a parallel structure, which effectively reduces the mutual influence between the main drive mechanism 10 and the auxiliary drive mechanism 20, further reduces the torque that the main drive mechanism 10 needs to provide, and is also advantageous in reducing the volume of the main drive mechanism 10.

[0031] Referring to Figures 1 to 5 together, Figure 3 is a schematic diagram of the exploded structure of the main transmission arm and transmission mechanism shown in Figure 2, Figure 4 is a schematic diagram of the structure of the transmission mechanism shown in Figure 2, and Figure 5 is a schematic diagram of the assembled structure of the crankshaft and first connecting rod in the transmission mechanism shown in Figure 4.

[0032] The main transmission arm 40 includes a main arm housing 41 and a main arm cover plate (not shown), and the main arm cover plate is connected to the main arm housing 41 to cover the space within the main arm housing 41 .

[0033] 3 to 5, the transmission mechanism 50 includes two sets of rotating members 51, two crankshafts 52, and two first connecting rods 53. One crankshaft 52 is installed corresponding to one set of rotating members 51, and the two first connecting rods 53 are rotatably connected between the two crankshafts 52.

[0034] Each set of rotating members 51 includes a first rotating member 511 and a second rotating member 512 that are coaxially arranged, and the first rotating member 511 and the second rotating member 512 are spaced apart, and the crankshaft 52 is fixedly connected between the first rotating member 511 and the second rotating member 512. Here, the first rotating member 511 is rotatably mounted on the main arm cover plate, and the second rotating member 512 is rotatably mounted on the main arm housing 41.

[0035] In this embodiment, the first rotating member 511 and the second rotating member 512 are both flanges.

[0036] Optionally, the first rotating member 511 and the second rotating member 512 may further include a rotating shaft and an extension arm installed at one end of the rotating shaft, the extension arm being perpendicular to the axis of the rotating shaft, and the crankshaft 52 being connected to one end of the extension arm away from the rotating shaft.

[0037] 3, bearing mounting portions 411 are provided on both the main arm housing 41 and the main arm cover plate, bearings 412 are mounted on the bearing mounting portions 411, and the first rotating member 511 and the second rotating member 512 are mounted on the inner rings of the corresponding bearings 412, which can further improve the transmission accuracy and transmission efficiency of the first rotating member 511 and the second rotating member 512. In the two sets of rotating members 51, the two first rotating members 511 may have the same or different outer dimensions, and the two second rotating members 512 may have the same or different outer dimensions, which can be adaptively adjusted according to the structural dimensions of the main transmission arm 40.

[0038] 5 and 6, Fig. 6 is a structural schematic diagram of the crankshaft in the transmission mechanism shown in Fig. 5. Each of the two crankshafts 52 includes a connecting arm 520 and a first shaft 521 and a second shaft 522 installed on either side of the connecting arm 520, i.e., the first shaft 521 and the second shaft 522 are located on opposite sides of the connecting arm 520. The axis of the first shaft 521 and the axis of the second shaft 522 are not on the same line; in other words, the axis of the first shaft 521 and the axis of the second shaft 522 may be parallel to or intersect each other, and may not be on the same plane.

[0039] As shown in Figures 3 to 6, the first shaft 521 is connected to the first rotating member 511 and is installed eccentrically relative to the first rotating member 511, and the second shaft 522 is connected to the second rotating member 512 and is installed eccentrically relative to the second rotating member 512, and the eccentric distance of the first shaft 521 from the center of the first rotating member 511 may or may not be equal to the eccentric distance of the second shaft 522 from the center of the second rotating member 512.

[0040] The two first connecting rods 53 are of equal length, and both ends of one first connecting rod 53 are rotatably connected to the two first shafts 521, while both ends of the other first connecting rod 53 are rotatably connected to the two second shafts 522. That is, the two first connecting rods 53 are located on either side of the connecting arm 520, respectively, and in different motion planes. That is, the two first connecting rods 53 do not interfere with each other and can move in conjunction with each other, thereby smoothly passing through each other's dead center positions and forming continuous transmission.

[0041] Here, when the first rotating member 511 or the second rotating member 512 in one set of rotating members 51 rotates, the crankshaft 52 connected thereto is rotated, and the first rotating member 511 and the second rotating member 512 in the set of rotating members 51 are further rotated by the crankshaft 52. The two crankshafts 52 are moved relative to each other by crossing and transmitting power through two first connecting rods 53, and can smoothly pass through each other's dead center positions, further rotating the other set of rotating members 51, i.e., the first rotating member 511 and the second rotating member 512 in the other set of rotating members 51 both rotate.

[0042] In this embodiment, the auxiliary transmission arm 30 is fixed coaxially to one of the first rotating members 511 in the transmission mechanism 50. The auxiliary drive mechanism 20 is fixed coaxially to the other of the first rotating members 511 in the transmission mechanism 50, and drives the auxiliary transmission arm 30 to rotate.

[0043] Alternatively, the auxiliary transmission arm 30 may be fixed coaxially with either one of the first rotating member 511 and the second rotating member 512 in one set of rotating members 51, and the auxiliary drive mechanism 20 may be fixed coaxially with either one of the first rotating member 511 and the second rotating member 512 in another set of rotating members 51.

[0044] The auxiliary drive mechanism 20 rotationally drives the other first rotating member 511, which in turn drives the eccentrically arranged crankshaft 52, transmitting power to the other crankshaft 52 via the first connecting rod 53, and finally rotationally drives the first rotating member 511 in the other set of rotating members 51, thereby rotationally driving the auxiliary transmission arm 30 around the axis of the first rotating member 51, whereupon the second rotating member 512 is used to support the crankshaft 52, thereby releasing the rotation restriction on the crankshaft 52.

[0045] In this embodiment, the axis of the first shaft 521 is parallel to the axis of the second shaft 522, and the two first connecting rods 53 are located in different rotation planes and are installed parallel to each other, so the rotation efficiency of the two first connecting rods 53 is also relatively high.

[0046] Alternatively, the axis of the first shaft 521 and the axis of the second shaft 522 may intersect, and at least one of the first connecting rods 53 may be a multi-link structure, i.e., a plurality of links may be connected in sequence to form the first connecting rod 53, and the multi-link structure may be used to transmit the power of the first shaft 521 or the second shaft 522, which may have a different structure.

[0047] Referring to FIG. 7, FIG. 7 is a schematic top view of a set of rotating members and a crankshaft in the transmission mechanism shown in FIG.

[0048] Furthermore, the axis of first rotating member 511 is taken as a reference line, and the angle at which the axis of first shaft 521 deviates from the axis of second shaft 522 is greater than 0° and less than 180°.

[0049] 7 , in this embodiment, the first rotating member 511 is a rotating member, and the axis of the rotating member is used as a reference line. The axis of the first shaft 521 and the axis of the second shaft 522 are parallel to each other. The angle by which the axis of the first shaft 521 deviates from the axis of the second shaft 522, i.e., the angle between the connecting line L1 and the connecting line L2, is greater than 0° and less than 180°. Here, the connecting line L1 connects the axis of the first rotating member 511 to the axis of the first shaft 521 and is perpendicular to the axis of the first rotating member 511 and the axis of the first shaft 521. The connecting line L2 connects the axis of the first rotating member 511 to the axis of the second shaft 522 and is perpendicular to the axis of the first rotating member 511 and the axis of the first shaft 521. By limiting the included angle between the connecting lines L1 and L2 to greater than 0° and less than 180°, the dead center positions of the two first connecting rods 53 can be prevented from overlapping, thereby enabling the transmission mechanism 50 to transmit power continuously.

[0050] As shown in Figure 6, in crankshaft 52, connecting arm 520 is rod-shaped, first shaft body 521 and second shaft body 522 are provided at both ends of connecting arm 520, and the axis of first shaft body 521 and the axis of second shaft body 522 are parallel to each other.

[0051] Referring to Figures 8 and 9, Figure 8 is a schematic diagram of the assembly structure of the crankshaft, first connecting rod, and second connecting rod in the transmission mechanism shown in Figure 4, and Figure 9 is a schematic diagram of the structure of the crankshaft shown in Figure 8.

[0052] The crankshaft 52 further includes at least one third shaft 523, and the connecting arm 520 includes at least two sub-arms 524, with two adjacent sub-arms 524 fixedly connected via the third shaft 523. The transmission mechanism 50 further includes second connecting rods 54, the number of which is the same as the number of the third shafts 523, and both ends of the second connecting rods 54 are rotatably connected to the two corresponding third shafts 523 in the two sets of crankshafts 52.

[0053] Here, the number of third shafts 523 may be one, two, three, or more, and the number of corresponding sub-arms 524 may be two, three, four, etc. The two sub-arms 524 are both fixedly connected via the third shafts 523, and at least one end of the third shafts 523 is detachably connected to the sub-arms 524, thereby making it easy to attach the second connecting rod 54 to the third shafts 523.

[0054] The first shaft 521 is mounted on the sub-arm 524 closest to the first rotating member 511 and is connected to the first rotating member 511. The second shaft 522 is mounted on the sub-arm 524 closest to the second rotating member 512 and is connected to the second rotating member 512.

[0055] The axial directions of the first shaft 521 and the second shaft 522 are both parallel to the axis of the third shaft 523. When the crankshaft 52 includes at least two third shafts 523, the axes of two adjacent third shafts 523 are also parallel to each other.

[0056] With the axis of the first rotating member 511 as the reference line, the angle by which the axis of the first shaft 521 and the axis of the second shaft 522 deviate from the axis of the adjacent third shaft 523 is greater than 0° and less than 180°, thereby preventing the dead center positions of the first connecting rod 53 and the second connecting rod 54 from overlapping and allowing the first connecting rod 53 and the second connecting rod 54 to drive each other, thereby enabling continuous transmission of power.

[0057] Furthermore, when the crankshaft 52 includes at least two third shafts 523, the axis of the first rotating member 511 is taken as the reference line, and the offset angle between the axes of two adjacent third shafts 523 is greater than 0° and less than 180°, thereby avoiding the dead center positions of multiple second connecting rods 54 from overlapping.

[0058] The two adjacent sub-arms 524 are offset from each other to optimize the transmission efficiency of the first connecting rod 53 and the second connecting rod 54 .

[0059] The lengths of two adjacent sub-arms 524 may or may not be equal. In this embodiment, the lengths of two adjacent sub-arms 524 are equal, and the first shaft 521, the second shaft 522, and the third shaft 523 are all installed at the ends of the sub-arms 524. Here, the connecting lines between the axes of the adjacent first shaft 521, the second shaft 522, and the third shaft 523 form a regular polygon, and the connecting lines are connected to and perpendicular to the axes of the two adjacent shafts, thereby optimizing the transmission efficiency of the transmission mechanism 50, making the transmission efficiency of each connecting rod more balanced, and the transmission more stable.

[0060] In this embodiment, the axis of the third shaft 523 is parallel to the axis of the first shaft 521, and the lengths of the first connecting rod 53 and the second connecting rod 54 are equal, thereby enabling the transmission mechanism 50 to transmit continuously.

[0061] The rotational connection manner of the first connecting rod 53 and the second connecting rod 54 may be the same or different, and is not specifically limited in this application.

[0062] In this embodiment, the connection method in which both ends of the first connecting rod 53 are rotatably connected to the two first shafts 521 or the two second shafts 522 is the same as the connection method in which both ends of the second connecting rod 54 are rotatably connected to the two third shafts 523, and both are rotatably connected via bearings, thereby reducing resistance loss and improving transmission efficiency and transmission accuracy.

[0063] As shown in FIG. 3, specifically, the transmission mechanism 50 further includes a first bearing 551 and a second bearing 552, the first bearing 551 is installed between the first shaft 521 and one corresponding first connecting rod 53, and the second bearing 552 is installed between the second shaft 522 and the other corresponding first connecting rod 53. Gaskets are also provided on both ends of the first bearing 551 and the second bearing 552, thereby fixing the first bearing 551 and the second bearing 552 in the axial direction and preventing the first bearing 551 and the second bearing 552 from moving axially.

[0064] A first positioning portion (not shown) is provided on the first rotating member 511, and the first positioning portion is installed eccentrically relative to the first rotating member 511, and one end of the first shaft 521 remote from the connecting arm 520 is aligned with and connected to the first positioning portion. A second positioning portion 513 is provided on the second rotating member 512, and the second positioning portion 513 is installed eccentrically relative to the second rotating member 512, and one end of the second shaft 522 remote from the connecting arm 520 is aligned with and connected to the second positioning portion 513.

[0065] The first positioning portion and the second positioning portion 513 may be a positioning groove or a positioning protrusion, which makes it easier to align and connect the corresponding first shaft body 521 or second shaft body 522, thereby improving assembly efficiency.

[0066] In this embodiment, the first positioning portion and the second positioning portion 513 are both positioning grooves, and the first shaft 521 and the second shaft 522 both include a first shaft step 525 and a second shaft step 526 that are arranged in a stepped shape. The shaft diameter of the first shaft step 525 is larger than that of the second shaft step 526. The first bearing 551 or the second bearing 552 is fitted into the first shaft step 525, and the second shaft step 526 is inserted into the positioning groove. The stepped surface between the first shaft step 525 and the second shaft step 526 meets the end face of the positioning groove, so that the axial force applied to the first bearing 551 and the second bearing 552 can be released.

[0067] 3 and 6, the first shaft 521 and the second shaft 522 are both provided with a first connecting hole 527 and a first positioning hole 528, with the plurality of first positioning holes 528 surrounding the first connecting hole 527. The bottom wall of the positioning groove is provided with a second connecting hole 515 and a second positioning hole 516, with the plurality of second positioning holes 516 surrounding the second connecting hole 515. The first positioning hole 528 and the second positioning hole 516 are connected via a positioning member, thereby ensuring coaxiality between the crankshaft 52 and the first rotating member 511 and the second rotating member 512 and improving transmission accuracy and efficiency. The first connecting hole 527 and the second connecting hole 515 are connected via a fastening member.

[0068] Here, the positioning member may be a pin or plug member, etc., and the fastening member may be a screw or stud, etc., the first connecting hole is an optical hole (an unthreaded hole with a smooth inner wall and no screws, knurling, or apertures), and the second connecting hole is a threaded hole, the diameter of which is larger than that of the threaded hole, which can eliminate hole processing errors and make installation easier. Specifically, first, the first positioning hole 528 and the second positioning hole 516 are connected via the positioning member, and the first shaft 521 or the second shaft 522 is aligned with the positioning groove, and then the fastening members are used to fasten them.

[0069] In this embodiment, the first shaft 521 and the second shaft 522 are further provided with a weight-reducing groove 529, the connecting arm 520 is provided with a relief hole corresponding to the weight-reducing groove 529, and the first connecting hole 527 and the first positioning hole 528 are located on the bottom wall of the weight-reducing groove 529, which makes the crankshaft 52 lighter, easier to drive, and helps reduce energy loss.

[0070] The first connecting rod 53 and / or the second connecting rod 54 are provided with weight reduction holes, which reduce the weight of the first connecting rod 53 and / or the second connecting rod 54, improve the transmission efficiency, and are advantageous in reducing energy loss.

[0071] Unlike the prior art, this application discloses a robot and its transmission mechanism. By providing two sets of rotating members, each set includes a first rotating member and a second rotating member arranged coaxially. The first rotating member is used to connect to an external structural component, thereby achieving power transmission. An eccentric crankshaft is provided between the first and second rotating members. Two first connecting rods are rotatably connected to the two crankshafts. The two first connecting rods are in different rotational planes, allowing them to move smoothly through each other's dead center positions without interfering with each other, thereby achieving continuous transmission. That is, power transmission between the two sets of rotating members is achieved through the crankshafts and the first connecting rods. The double-connecting rod transmission structure further improves transmission precision, increases transmittable torque, and increases overall rigidity. The transmission mechanism provided by this application has a simple structure, is easy to process and install, and is low-cost.

[0072] The above are embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by utilizing the contents of the specification and drawings of the present application, or any directly or indirectly applicable to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A transmission mechanism including two sets of rotating members, two crankshafts, and two first connecting rods, Each set of the rotary members includes a first rotary member and a second rotary member that are coaxially arranged, Each of the two crankshafts includes a connecting arm and a first shaft and a second shaft disposed on opposite sides of the connecting arm, the axis of the first shaft and the axis of the second shaft being not on the same line, the first shaft being connected to the first rotating member and disposed eccentrically relative to the first rotating member, and the second shaft being connected to the second rotating member and disposed eccentrically relative to the second rotating member, one end of each of the two first connecting rods is rotatably connected to the two first shafts, and the other end of each of the two first connecting rods is rotatably connected to the two second shafts; When the first rotating member or the second rotating member of one set of rotating members rotates, the crankshaft connected thereto is rotated, and power is transmitted between the two crankshafts via the two first connecting rods, thereby rotating another set of rotating members. The connecting arm has a rod shape, the transmission mechanism further includes a first bearing and a second bearing, the first bearing being disposed between the first shaft and one of the first connecting rods corresponding to the first shaft, and the second bearing being disposed between the second shaft and the other of the first connecting rods corresponding to the second shaft; a first positioning portion is provided on the first rotating member, the first positioning portion is eccentrically installed with respect to the first rotating member, and one end of the first shaft remote from the connecting arm is aligned and connected to the first positioning portion; a second positioning portion is provided on the second rotating member, the second positioning portion is eccentrically installed with respect to the second rotating member, and one end of the second shaft remote from the connecting arm is aligned and connected to the second positioning portion; a transmission mechanism in which the first positioning portion and the second positioning portion are both positioning grooves, the first shaft body and the second shaft body both include a first shaft step portion and a second shaft step portion arranged in a stepped manner, the shaft diameter of the first shaft step portion is larger than the shaft diameter of the second shaft step portion, the first bearing or the second bearing is fitted into the first shaft step portion, the second shaft step portion is inserted into the positioning groove, and a step surface between the first shaft step portion and the second shaft step portion is fastened to an end face of the positioning groove.

2. 2. The transmission mechanism according to claim 1, wherein an axis of the first shaft and an axis of the second shaft are parallel to each other.

3. 3. The transmission mechanism according to claim 2, wherein an angle at which the axis of the first shaft deviates from the axis of the second shaft is greater than 0° and less than 180°, with the axis of the first rotating member being a reference line.

4. The transmission mechanism according to claim 3 , wherein the first shaft and the second shaft are installed at opposite ends of the connecting arm.

5. the crankshaft further includes at least one third shaft, an axis of the third shaft being parallel to an axis of the first shaft, the connecting arm includes at least two sub-arms, and two adjacent sub-arms are fixedly connected via the third shaft; 4. The transmission mechanism according to claim 3, further comprising second connecting rods, the number of the second connecting rods being the same as the number of the third shafts, and both ends of the second connecting rod being rotatably connected to two corresponding third shafts of the two crankshafts.

6. 6. The transmission mechanism according to claim 5, wherein the axis of the first rotating member is a reference line, and the angle by which the axis of the first shaft and the axis of the second shaft deviate from the axis of the adjacent third shaft is greater than 0° and less than 180°.

7. 6. The power transmission mechanism according to claim 5, wherein an offset angle between the axes of two adjacent third shafts is greater than 0° and less than 180° when the axis of the first rotating member is used as a reference line.

8. The transmission mechanism according to claim 5 , wherein two adjacent sub-arms are arranged with a stagger.

9. 6. The power transmission mechanism of claim 5, wherein the first connecting rod and the second connecting rod have the same length.

10. The first shaft and the second shaft are each provided with a first connecting hole and a first positioning hole, and a plurality of the first positioning holes are arranged around the first connecting hole; A second connection hole and a second positioning hole are provided on the bottom wall of the positioning groove, and a plurality of the second positioning holes are arranged around the second connection hole; The transmission mechanism according to claim 1 , wherein the first positioning hole and the second positioning hole are connected via a positioning member, and the first connecting hole and the second connecting hole are connected via a fastening member.

11. 11. The transmission mechanism according to claim 10, wherein the first shaft and the second shaft are further provided with weight-reducing grooves, the connecting arm is provided with relief holes corresponding to the weight-reducing grooves, and the first connecting hole and the first positioning hole are located on the bottom wall of the weight-reducing grooves.

12. A robot including a main transmission arm, a transmission mechanism, an auxiliary transmission arm, an auxiliary drive mechanism, and a main drive mechanism, The transmission mechanism is provided in the main transmission arm, and the transmission mechanism is the transmission mechanism according to any one of claims 1 to 11, the auxiliary transmission arm is rotatably disposed at one end of the main transmission arm and is fixed coaxially with the first rotating member of one of the transmission mechanisms, the auxiliary drive mechanism is fixed coaxially with the other first rotating member of the transmission mechanism so as to rotationally drive the auxiliary transmission arm, the main driving mechanism is connected to the main transmission arm and is used to rotationally drive the main transmission arm, and the main driving mechanism and the auxiliary driving mechanism are both installed at one end of the main transmission arm away from the auxiliary transmission arm and are respectively arranged on two opposite sides of the main transmission arm.

Citation Information

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