An adaptive rope-driven joint

Abstract

The application discloses a self-adaptive rope driving joint, which comprises a support, a driving mechanism, a swing assembly, a tensioning mechanism and a movable platform. The driving mechanism is composed of a motor, a driving rope, a pulley and a support base, is fixedly installed at the bottom of the support, is connected with the movable platform through the driving rope, and makes the movable platform rotate by adjusting the length of the driving rope through the motor. The swing assembly is rotatably installed on the support and is rotatably connected with the movable platform. The tensioning mechanism is composed of springs, fixed pulleys, pulley seats and tensioning ropes, has two groups, is symmetrically arranged on the two sides of the support, and is connected with the swing assembly at the end of the tensioning rope, so that the driving rope is kept tensioned at all times. The movable platform and the support are provided with bolt connection installation holes, so that the joint is convenient to install and maintain. The application has the advantages of no gap, small rotational inertia, simple and compact structure, large load self-weight ratio, good safety performance and the like, provides a novel joint configuration for the design of a humanoid robot arm, and has a wide application scenario.

Description

Technical Field

[0001] The present invention relates to the field of humanoid robotic arms, and in particular to an adaptive rope-driven joint. Background Art

[0002] Service robotic arms are widely used in the field of intelligent nursing due to their excellent interactive capabilities. In this scenario of frequent human-machine interaction, the safety of the robotic arm has become a major concern. The safety of the robotic arm depends largely on the design of its joints. Currently, robotic arm joints are mainly divided into two categories: rigid and flexible. Rigid joints are widely used in various fields due to their high stability, high precision and long life, but their safety is relatively low. In emergency situations, they may cause impact and cause harm to people or equipment. In comparison, adaptive flexible joints, a research hotspot in recent years, stand out for their excellent safety, high load-to-weight ratio and high flexibility, but they still lack the stability, precision and load-bearing capacity of rigid joints. Summary of the Invention

[0003] In response to the above-mentioned prior art, the present invention provides an adaptive rope-driven joint. This joint features advantages such as zero backlash, low rotational inertia, a simple and compact structure, a high load-to-weight ratio, and excellent safety performance, making it suitable for robotic arms with high safety requirements. With its advantages of zero backlash, low rotational inertia, simple and compact structure, high load-to-weight ratio, and excellent safety performance, the adaptive rope-driven joint proposed in the present invention better meets the safety requirements of service robotic arms and presents broad application prospects.

[0004] In order to solve the above technical problems, the present invention proposes an adaptive rope-driven joint, comprising a bracket and a moving platform, a swing assembly and a driving mechanism provided between the moving platform and the bracket; the bracket comprises a base plate and two parallel side plates arranged on the base plate, the driving mechanism comprises a support fixed to the base plate, a motor and a pulley are fixed on the support, and a driving rope is wound around the output shaft of the motor; the swing assembly comprises a first rocker arm, a second rocker arm, a long pin shaft, a stud and a pin shaft; a through hole is provided in the middle of the moving platform with a clearance fit with the long pin shaft, the long pin shaft passes through the through hole, the first rocker arm and the second rocker arm are connected to form a rocker arm of an integrated structure by the stud shaft, and one end of the rocker arm is rotatably connected to the moving platform through the long pin shaft; The other end of the rocker arm is rotatably connected to the bracket through the pin shaft; one side of the moving platform is recorded as side A, and the other side of the moving platform is recorded as side B. One end of the driving rope is connected to the A side of the moving platform after passing through the pulley, and the other end of the driving rope is connected to the B side of the moving platform; a group of tensioning mechanisms are symmetrically arranged between the first rocker arm and the base plate and between the second rocker arm and the base plate, respectively, and the tensioning mechanism includes a pulley seat fixed on the side plate and located on the A side of the moving platform, a fixed pulley is installed on the pulley seat, and a tensioning rope is wound around the fixed pulley, one end of the tensioning rope is connected to a fixed point on the rocker arm located on the A side of the moving platform, and the other end of the tensioning rope is connected to one end of a spring fixed to the base plate.

[0005] Furthermore, the adaptive rope-driven joint of the present invention, wherein:

[0006] The first rocker arm and the second rocker arm are arranged in parallel.

[0007] An adjustment structure is provided between the tensioning rope and the spring, and the adjustment structure includes a lifting eye nut and a bolt. The bolt is connected to the tensioning rope, and the spring is hung on the lifting eye nut. By adjusting the length of the spiral connection between the lifting eye nut and the bolt, the elongation of the spring is changed, thereby adjusting the tension of the tensioning rope.

[0008] The connection structure between the drive rope and the motor output shaft is that the output shaft is designed as a hollow shaft, which is provided with two radial through holes with consistent axial positions and coaxial alignment. The drive rope is provided with a knot, and the knot is embedded in the hollow shaft. The two ends of the drive rope respectively pass through the two radial through holes and then wrap around the motor output shaft in opposite directions for several turns, and then are connected to both sides of the moving platform.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] (1) Due to the combined effects of the driving mechanism, swing assembly, and tensioning mechanism of the present invention, the dynamic platform can automatically adjust its posture according to changes in the driving angle and external force. The present invention has the characteristic of self-adaptation.

[0011] (2) Since the tensioning mechanism of the present invention introduces an elastic element, the joint mechanism and structure have an automatic tensioning platform, eliminating the mechanism gap and improving the bearing capacity of the joint.

[0012] (3) The present invention adopts single-motor rope drive technology. This design reduces the joint mass, reduces the rotational inertia of the moving platform, and makes the structure more compact while maintaining good adaptability.

[0013] (4) The present invention uses modular components such as supports, pulley seats, and rocker arms to replace traditional integrated complex components, which can effectively reduce manufacturing costs, improve positioning accuracy, optimize component stress conditions, and significantly reduce joint size.

[0014] (5) The adjustment mechanism of the present invention can flexibly adjust the elongation of the spring, and thus adjust the tension of the rope to adapt to different load requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of the adaptive rope-driven joint of the present invention;

[0016] Figure 2 For oneself Figure 1 A cross-sectional view of the structure cut through the side panel at the front;

[0017] Figure 3 for Figure 1 A schematic diagram of the structure of the driving mechanism shown in FIG;

[0018] Figure 4 For oneself Figure 3 A cross-sectional view of the motor output shaft and the pulley from the rear side after the cross section is cut;

[0019] Figure 5 for Figure 1 Schematic diagram of the structure of the swing assembly and tensioning mechanism shown in.

[0020] In the picture:

[0021] 1- bracket 11- bottom plate 12- side plate 2- driving mechanism

[0022] 21-motor 22-drive rope 23-pulley 24-support

[0023] 25-knot 3-swing assembly 31-first swing rod 32-second swing rod

[0024] 33-long pin 34-stud 35-pin 36-fixing point

[0025] 4-Tensioning mechanism 41-Spring 42-Eye nut 43-Bolt

[0026] 44- tensioning rope 45- fixed pulley 46- pulley seat 5- moving platform DETAILED DESCRIPTION

[0027] The design concept of an adaptive rope-driven joint proposed in this invention is as follows: the joint primarily comprises a bracket, a drive mechanism, a swing assembly, a tensioning mechanism, and a moving platform. To reduce the rotational inertia of the joint's moving platform, the drive mechanism consists of a motor, a drive rope, a pulley, and a support. The motor rotates the moving platform by adjusting the length of the drive rope, which is connected to the moving platform at both ends. To ensure support for the moving platform, a swing assembly and a tensioning mechanism are arranged on the bracket. The swing assembly is pivotally connected to the bracket's side plate at one end and to the moving platform at the other end, providing support for the platform. The tensioning mechanism consists of two sets of springs, a fixed pulley, a pulley seat, and tensioning ropes, symmetrically arranged on either side of the bracket. The ends of the tensioning ropes are connected to the swing assembly, transmitting the tensioning force to the swing assembly. To facilitate joint installation and subsequent maintenance, bolt connection holes are machined into the moving platform and bracket. The above structures collectively achieve the adaptive rope-driven joint's numerous advantages, including seamless transmission, reduced rotational inertia, a simple and compact structure, a high load-to-weight ratio, and excellent safety performance. These characteristics make it a new type of joint configuration in humanoid robotic arm design, and it has a wide range of application scenarios and can meet the needs of different fields for high-precision and high-reliability joints.

[0028] In the description of the present invention, it should be noted that the terms "upper", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "first" and "second" do not indicate the degree of importance, but are intended to distinguish different identical structures. The terms "connected" and "connected" should be understood in a broad sense. For example, they can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0030] like Figure 1 and Figure 2As shown, the present invention proposes an adaptive rope-driven joint, which includes a bracket 1 and a moving platform 5, a swing component 3 and a driving mechanism 2 are provided between the moving platform 5 and the bracket 1, and a group of tensioning mechanisms 4 are symmetrically arranged between the swing component 3 and the bracket 1.

[0031] The bracket 1 includes a bottom plate 11 and two parallel side plates 12 arranged on the bottom plate 11. Figure 2 The driving mechanism 2 includes a support 24 fixed on the base plate 11, and a motor 21 and a pulley 23 are fixed on the support 24. In the present invention, the motor 21 and the pulley 23 are installed and positioned by the support 1, which can improve positioning accuracy and reduce manufacturing costs. A driving rope 22 is wound around the output shaft of the motor 21. Figure 3 and Figure 4 As shown, in the present invention, the connection structure between the driving rope 22 and the output shaft of the motor 21 is as follows: Figure 4 As shown, the output shaft is designed as a hollow shaft, which is provided with two radial through holes with consistent axial positions and coaxial alignment. A knot 25 is provided on the driving rope 22, and the knot 25 is embedded in the hollow shaft. The two ends of the driving rope 22 respectively pass through the two radial through holes and then go around the output shaft of the motor 21 in opposite directions for several turns, and then are connected to both sides of the moving platform 5.

[0032] like Figure 1 、 Figure 2 and Figure 5As shown, in order to improve the force of the swing assembly, in the present invention, two groups of rocker arms, namely a first rocker arm 31 and a second rocker arm 32, are symmetrically arranged on both sides of the moving platform 5. The swing assembly 3 in the present invention includes a first rocker arm 31, a second rocker arm 32, a long pin shaft 33, a stud 34 and a pin shaft 35. A through hole is provided in the middle of the moving platform 5, which is clearance-matched with the long pin shaft 33. The long pin shaft 33 passes through the through hole, and the first rocker arm 31 and the second rocker arm 32 are arranged in parallel. In order to improve the force condition of the swing assembly 3, the stud 34 and other connecting parts are used to fix the first rocker arm 31 and the second rocker arm 32 to form a rocker arm of an integrated structure. One end of the rocker arm is rotatably connected to the moving platform 5 through the long pin shaft 33; the other end of the rocker arm is provided with a pin shaft 35. Pin holes corresponding to the positions of the pin shafts are provided on the two side plates 12 of the bracket 1. The rocker arm is rotatably connected to the bracket 1 through the cooperation of the pin shaft 35 and the pin hole. In the present invention, one side of the movable platform 5 is designated as side A, and the other side of the movable platform 5 is designated as side B. One end of the drive rope 22 passes over the pulley 23 and is connected to side A of the movable platform 5, while the other end of the drive rope 22 is connected to side B of the movable platform 5. The motor 21 drives the output shaft to rotate, changing the length of the drive ropes 22 connected to both sides of the movable platform 5, thereby driving the movable platform 5 to rotate. The rope drive method designed in the present invention allows the movable platform 5 to be driven by only one motor 21, reducing the number of motors and effectively reducing the mass of the adaptive rope-driven joint. Furthermore, the relative position of the drive rope 22 and the movable platform 5 is changed by the pulley 23, improving the force applied to the movable platform 5.

[0033] like Figure 4 As shown, in order to improve the stress of the tensioning mechanism and increase the carrying capacity of the moving platform 5, in the present invention, two sets of tensioning mechanisms 4 with the same structure are symmetrically installed on both sides of the moving platform 5, and the tensioning mechanism 4 includes a pulley seat 46 fixed on the side plate 12 and located on the A side of the moving platform 5. A fixed pulley 45 is installed on the pulley seat 46, and the fixed pulley 45 is connected to the pulley seat 46 by supporting on both sides, which can improve the stress of the fixed pulley; a tensioning rope 44 is wound around the fixed pulley 45, and one end of the tensioning rope 44 is connected to a fixed point 36 on the rocker arm located on the A side of the moving platform 5, and the other end of the tensioning rope 44 is directly connected to one end of the spring 41 fixed on the bottom plate 11 or is connected through an adjustment structure. By changing the tension direction of the spring 41 through the fixed pulley 45, the external dimensions of the rope-driven joint can be significantly reduced. In order to improve the stress, two sets of identical tensioning mechanisms can be symmetrically arranged on both sides of the moving platform. As shown Figure 5As shown, the adjustment structure includes a lifting nut 42 and a bolt 43, and the bolt 43 is connected to the tensioning rope 44. The spring 41 is hung on the lifting nut 42. By adjusting the length of the spiral connection between the lifting nut 42 and the bolt 43, the elongation of the spring 41 is changed, and the tension of the tensioning rope 44 is adjusted.

[0034] In the present invention, a plurality of mounting holes are provided on the moving platform 5 and the bracket 1 to facilitate the installation and maintenance of the joints and other parts of the robotic arm.

[0035] In summary, the present invention has the advantages of no gap, small rotational inertia, simple and compact structure, large load-to-weight ratio, and good safety performance. It is suitable for high-speed motion robot arm joints with high safety performance requirements.

[0036] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many improvements and changes without departing from the purpose of the present invention, which are all protected by the present invention.

Claims

1. An adaptive rope-driven joint, comprising a bracket (1) and a movable platform (5), wherein a swing assembly (3) and a drive mechanism (2) are provided between the movable platform (5) and the bracket (1); the bracket (1) comprises a bottom plate (11) and two parallel side plates (12) arranged on the bottom plate (11), characterized in that: The driving mechanism (2) comprises a support (24) fixed on the base plate (11), a motor (21) and a pulley (23) are fixed on the support (24), and a driving rope (22) is wound around the output shaft of the motor (21); The swing assembly (3) comprises a first swing rod (31), a second swing rod (32), a long pin (33), a stud (34) and a pin (35); A through hole is provided in the middle of the movable platform (5) and is clearance-matched with the long pin shaft (33). The long pin shaft (33) passes through the through hole. The first rocker arm (31) and the second rocker arm (32) are connected to form a rocker arm of an integrated structure via the stud (34). One end of the rocker arm is rotationally connected to the movable platform (5) via the long pin shaft (33); the other end of the rocker arm is rotationally connected to the bracket (1) via the pin shaft (35). One side of the moving platform (5) is marked as side A, and the other side of the moving platform (5) is marked as side B. One end of the driving rope (22) passes around the pulley (23) and is connected to side A of the moving platform (5), and the other end of the driving rope (22) is connected to side B of the moving platform (5); A group of tensioning mechanisms (4) are symmetrically arranged between the first rocker (31) and the base plate (11) and between the second rocker (32) and the base plate (11). The tensioning mechanism (4) includes a pulley seat (46) fixed on the side plate (12) and located on the A side of the movable platform (5). A fixed pulley (45) is installed on the pulley seat (46). A tensioning rope (44) is wound around the fixed pulley (45). One end of the tensioning rope (44) is connected to a fixed point (36) on the rocker located on the A side of the movable platform (5), and the other end of the tensioning rope (44) is connected to one end of a spring (41) fixed on the base plate (11).

2. The adaptive rope-driven joint according to claim 1, characterized in that The first rocker (31) and the second rocker (32) are parallel.

3. The adaptive rope-driven joint according to claim 1, characterized in that An adjustment structure is provided between the tensioning rope (44) and the spring (41), and the adjustment structure includes a lifting nut (42) and a bolt (43). The bolt (43) is connected to the tensioning rope (44), and the spring (41) is hung on the lifting nut (42). By adjusting the length of the spiral connection between the lifting nut (42) and the bolt (43), the elongation of the spring (41) is changed, thereby adjusting the tension of the tensioning rope (44).

4. The adaptive rope-driven joint according to claim 1, characterized in that The connection structure between the driving rope (22) and the output shaft of the motor (21) is that the output shaft is designed as a hollow shaft, and the hollow shaft is provided with two radial through holes with consistent axial positions and coaxial alignment. The driving rope (22) is provided with a knot (25), and the knot (25) is embedded in the hollow shaft. The two ends of the driving rope (22) respectively pass through the two radial through holes and then pass around the output shaft of the motor (21) in opposite directions for several turns, and then are connected to the two sides of the moving platform (5).

Images