A compact flexible cable-driven robotic arm

Abstract

The present invention relates to a compact flexible cable-driven robotic arm. The joint assembly includes a joint axle bracket, a joint axle seat, a cable-passing flange, and a flexible cable guide ring. Two joint axle seats are respectively hinged to both sides of the joint axle bracket, and the end faces of the adjacent joint axle seats of adjacent joint assemblies are connected by a connecting rod. A cable-passing flange is provided on the joint axle seat, and a flexible cable guide ring is provided on any one of the cable-passing flanges. A flange flexible cable through-hole is provided on the cable-passing flange, and a guide ring flexible cable through-hole is provided on the flexible cable guide ring. The head end of the driving flexible cable passes through the corresponding flange flexible cable through-holes on each cable-passing flange of the corresponding joint assembly, and passes through the corresponding guide ring flexible cable through-hole on the flexible cable guide ring of the last joint assembly. A flexible cable fixing head is provided at the head end of the driving flexible cable, and a positioning seat with a fixing head groove is provided on the joint axle seat, and the head end of the driving flexible cable is buried in the corresponding fixing head groove. The present invention makes the joint structure compact while increasing the distribution radius of the flexible cable, improving the load capacity and flexibility of the robotic arm.

Description

Technical Field

[0001] The present invention relates to the field of special robots, and more specifically to a compact cable-driven robotic arm. Background Art

[0002] In the existing cable-driven robotic arms, since the cable fixing head is coaxially arranged with the driving cable, and the cable fixing head has a certain volume and protrudes from the joint surface, the joint structure is not compact enough. At the same time, there are also the following disadvantages: (1) The distribution radius of the driving cable is relatively small, and the driving force arm of the cable on the joint is small, which is not conducive to power transmission and joint control, and will also result in a relatively small load at the end of the robotic arm; (2) The number of driving cables that can be arranged in the circumferential direction is small, which will lead to a small number of robotic arm axes and low flexibility of the robotic arm; (3) Due to the small distribution radius of the cable, the hollow diameter of the robotic arm is small, which is not conducive to internal wiring. Summary of the Invention

[0003] The purpose of the present invention is to provide a compact cable-driven robotic arm, which makes the joint structure compact while increasing the cable distribution radius, thereby providing a larger cable force arm, improving the load capacity of the robotic arm, and increasing the number of driving cables that can be arranged at the joint, improving the flexibility of the robotic arm.

[0004] The purpose of the present invention is achieved by the following technical solutions:

[0005] A compact cable-driven robotic arm includes a joint assembly, a driving cable, and a connecting rod. The joint assembly includes a joint shaft frame, a joint shaft seat, a rope-passing flange, and a cable guide ring. Two joint shaft seats are respectively hinged on both sides of the joint shaft frame, and the end faces of the adjacent joint shaft seats of adjacent joint assemblies are connected by corresponding connecting rods. Rope-passing flanges are provided on the outer sides of both joint shaft seats, and a cable guide ring is provided on the outer side of one of the rope-passing flanges. Flange cable through holes are evenly distributed on the rope-passing flanges, and guide ring cable through holes are evenly distributed on the cable guide ring. The cable guide rings of adjacent joint assemblies are arranged staggeredly. The head end of the driving cable sequentially passes through the corresponding flange cable through holes on each rope-passing flange of the corresponding joint assemblies, and passes through the corresponding guide ring cable through hole on the cable guide ring of the last joint assembly. A cable fixing head is provided at the head end of the driving cable. A positioning seat is provided on the joint shaft seat, and a fixing head groove and a slot communicating with the corresponding fixing head groove are provided on the positioning seat. The cable fixing head is arranged in the corresponding fixing head groove on the last joint shaft seat, and the head end of the driving cable forms a cable bending part buried between the cable guide ring and the corresponding joint shaft seat and passes through the corresponding slot.

[0006] The joint shaft frame is provided with mounting holes all around, the joint shaft seat includes a disc body, and a positioning seat is provided on one side of the disc body, and an ear plate is provided on the other side. The ear plate is rotatably installed in the mounting holes on the corresponding sides of the joint shaft frame through mounting pins, and the rotation axes of the two joint shaft seats are arranged in a cross.

[0007] Limiting grooves are arranged on both sides of the disk body of the joint shaft seat, and limiting blocks are arranged on both sides of the inner hole of the rope threading flange. The rope threading flange is sleeved on the disk body of the joint shaft seat, and the limiting blocks are clamped in the corresponding limiting grooves.

[0008] The disc body of the joint shaft seat is provided with a plurality of shaft seat pin holes, the flexible cable guide ring includes a ring body and a ring wall arranged on the outer edge of the ring body, and the ring body is provided with a plurality of guide ring pin holes, the shaft seat pin hole is concentric with any guide ring pin hole and is connected by a cylindrical pin.

[0009] The head end of the driving cable passes through the corresponding guide ring cable through hole and is arranged between the ring wall and the outer wall of the positioning seat of the corresponding joint shaft seat to form the cable bending part.

[0010] The pin holes of each shaft seat are evenly distributed along the circumferential direction, and the pin holes of each guide ring are unevenly distributed along the circumferential direction.

[0011] A flexible cable guide seat is provided on the outside of the flexible cable guide ring, a guide groove is provided inside the flexible cable guide seat, and a guide ring flexible cable through hole is provided at the bottom.

[0012] A gasket is provided on the rope threading flange of the joint assembly at a side away from the flexible rope guide ring.

[0013] Each joint assembly is driven by three driving flexible cables distributed along the circumferential direction, and the positioning seat of the joint shaft seat is evenly distributed along the circumferential direction with four fixing head grooves and four slots.

[0014] Both ends of the connecting rod are provided with lead-in holes.

[0015] The advantages and positive effects of the present invention are:

[0016] 1. The present invention inverts the cable fixing head and embeds it in the corresponding joint shaft seat, so that the joint structure is more compact. The cable distribution radius is increased while ensuring that there is no interference between the cable fixing head and the robot arm shell, thereby providing a larger cable force arm and improving the load capacity of the robot arm. In addition, the number of driving cables that can be arranged at the joint is increased, thereby allowing the robot arm as a whole to have more joints and improving the flexibility of the robot arm.

[0017] 2. Through the design of the angles and quantities of the shaft seat pin holes, guide ring pin holes, fixed head grooves, etc., each joint component of the present invention is independently assembled in a similar manner, and the only difference lies in the angle of the flexible cable guide ring. On the one hand, it meets the installation requirements of a relatively large number of driving flexible cables. On the other hand, the present invention has fewer types of parts and high interchangeability, which is convenient for maintenance and repair.

[0018] 3. Since the present invention increases the distribution radius of the flexible cable, the hollow diameter of the robotic arm is increased, and the internal wire routing space is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the overall schematic diagram of the present invention,

[0020] Figure 2 is Figure 1 the schematic diagram of the end of the present invention in

[0021] Figure 3 is Figure 1 the schematic diagram of the middle part of the present invention in

[0022] Figure 4 is Figure 1 the schematic diagram of the driving end of the present invention in

[0023] Figure 5 is Figure 2 the schematic diagram of the joint component and short connecting rod structure in

[0024] Figure 6 is Figure 5 the schematic diagram of the joint component structure in

[0025] Figure 7 is Figure 6 the top view of the joint component in

[0026] Figure 8 is Figure 5 the exploded schematic diagram of the joint component in

[0027] Figure 9 is Figure 8 the schematic diagram of the cross shaft seat structure in

[0028] Figure 10 is Figure 9 the top view of the cross shaft seat in

[0029] Figure 11 is Figure 8 the top view of the rope threading flange in

[0030] Figure 12 is Figure 11 the three-dimensional schematic diagram of the rope threading flange in

[0031] Figure 13 is Figure 8 a schematic diagram of the flexible cable guiding ring structure in

[0032] Figure 14 is Figure 13 a schematic diagram of another angle of the flexible cable guiding ring in

[0033] Figure 15 is Figure 13 a top view of the flexible cable guiding ring in

[0034] Among them, 1 is the joint assembly, 101 is the joint shaft frame, 102 is the joint shaft seat, 1021 is the ear plate, 1022 is the disc body, 1023 is the positioning seat, 1024 is the limiting groove, 1025 is the shaft seat pin hole, 1026 is the slotted opening, 1027 is the fixed head groove, 103 is the rope-passing flange, 1031 is the flexible cable through hole of the flange, 1032 is the limiting block, 104 is the flexible cable guiding ring, 1041 is the flexible cable guiding seat, 1042 is the guiding ring pin hole, 1043 is the flexible cable through hole of the guiding ring, 1044 is the ring body, 1045 is the ring wall, 105 is the gasket ring, 106 is the shaft sleeve, 107 is the mounting pin shaft, 108 is the flexible cable fixed head, 2 is the short connecting rod, 3 is the long connecting rod, 4 is the driving flexible cable, 401 is the flexible cable bending part, 5 is the end flange, and 6 is the lead hole. Specific embodiments

[0035] The present invention will be further described in detail below with reference to the accompanying drawings.

[0036] As Figures 1 to 15 shown, the present invention includes a joint assembly 1, a driving flexible cable 4 and a connecting rod. Among them, as Figures 5 to 15 shown, the joint assembly 1 includes a joint shaft frame 101, a joint shaft seat 102, a rope-passing flange 103, a flexible cable guiding ring 104 and a gasket ring 105. The two joint shaft seats 102 are respectively hinged on both sides of the joint shaft frame 101 to realize joint rotation. And as Figures 1 to 4 shown, the end faces of the adjacent joint shaft seats 102 of the adjacent joint assemblies 1 are connected by corresponding connecting rods. A rope-passing flange 103 is provided on one side of each joint shaft seat 102 away from the joint shaft frame 101. And a flexible cable guiding ring 104 is provided on one side of one of the rope-passing flanges 103 away from the corresponding joint shaft seat 102, and a gasket ring 105 is provided on one side of the other rope-passing flange 103 away from the corresponding joint shaft seat 102. As Figures 11 to 12 shown, flange flexible cable through holes 1031 are evenly distributed along the circumferential direction on the outer edge of the rope-passing flange 103. As Figures 13 to 15 shown, flexible cable guiding seats 1041 are evenly distributed along the circumferential direction on the outer edge of the flexible cable guiding ring 104. And a guiding groove is provided inside the flexible cable guiding seat 1041, and a flexible cable through hole 1043 of the guiding ring is provided at the bottom. As Figures 5 to 8As shown, the driving flexible cable 4 sequentially passes through the corresponding flange flexible cable through-holes 1031 on the cable-passing flanges 103 of each joint assembly 1, and passes through the corresponding guide ring flexible cable through-hole 1043 on the flexible cable guide ring 104 of the last joint assembly 1. A flexible cable fixing head 108 is provided at the head end of the driving flexible cable 4, as Figures 9 to 10 As shown, a positioning seat 1023 is provided on the joint axle seat 102, and fixing head grooves 1027 and slots 1026 are evenly distributed along the circumferential direction on the positioning seat 1023, and the slot 1026 communicates with the corresponding fixing head groove 1027, as Figures 6 to 7 As shown, the flexible cable fixing head 108 lies down and is buried in the corresponding fixing head groove 1027 on the last joint axle seat 102. The head end of the driving flexible cable 4 forms a flexible cable bending part 401 under the limitation of the flexible cable guide ring 104 and the positioning seat 1023 on the corresponding joint axle seat 102, and the flexible cable bending part 401 is buried between the flexible cable guide ring 104 and the corresponding joint axle seat 102 and passes through the corresponding slot 1026.

[0037] In the present invention, the flexible cable fixing head 108 lies down and is placed inside the corresponding joint axle seat 102, so that it no longer protrudes from the joint surface, making the structure more compact. At the same time, on the premise of ensuring that there is no interference between the flexible cable fixing head 108 and the robotic arm housing, the distribution radius of the flexible cable is increased, thereby providing a larger flexible cable force arm, improving the load capacity of the robotic arm. In addition, the number of driving flexible cables 4 that can be arranged at the joint is also increased, so that the robotic arm as a whole can have more joints, improving the flexibility of the robotic arm. As Figures 1 to 4 As shown, a total of 12 sets of joint assemblies 1 are provided in this embodiment. Each joint assembly 1 is driven by three driving flexible cables 4. The entire robotic arm is provided with 36 driving flexible cables. In addition, since the present invention increases the distribution radius of the flexible cable, the hollow diameter of the robotic arm is also increased, and further the internal wiring space is increased.

[0038] As Figures 8 to 9 As shown, mounting holes are provided all around the joint axle frame 101. The joint axle seat 102 includes a disc body 1022. A positioning seat 1023 is provided on one side of the disc body 1022, and an ear plate 1021 is provided on the other side. A through-hole is provided on the ear plate 1021, and the ear plate 1021 is rotatably mounted in the mounting hole on the corresponding side of the joint axle frame 101 through a mounting pin shaft 107. A bushing 106 is sleeved on the mounting pin shaft 107. The rotation axes of the two joint axle seats 102 are arranged in a cross shape, so as to realize the rotation of the entire joint assembly 1.

[0039] As Figures 9 to 10 As shown, limiting grooves 1024 are provided on both sides of the disc body 1022 of the joint axle seat 102, as Figures 11 to 12As shown, on both sides of the inner hole of the rope-passing flange 103, there are limiting blocks 1032. The rope-passing flange 103 is sleeved on the disk body 1022 of the joint shaft seat 102, and the limiting blocks 1032 are clamped in the corresponding limiting grooves 1024 to prevent relative rotation between the rope-passing flange 103 and the joint shaft seat 102.

[0040] As Figures 9 to 10 shown, on the outer edge of the disk body 1022 of the joint shaft seat 102, a plurality of shaft seat pin holes 1025 are evenly distributed along the circumferential direction. As Figures 14 to 15 shown, the flexible cable guiding ring 104 includes a ring body 1044 and a ring wall 1045. A through hole is provided in the middle of the ring body 1044 and is sleeved on the positioning seat 1023 of the corresponding joint shaft seat 102. A plurality of guiding ring pin holes 1042 are unevenly distributed along the circumferential direction on the ring body 1044. A ring wall 1045 is provided on the outer edge of the ring body 1044. The head end of the driving flexible cable 4 passes through the corresponding flexible cable through hole 1043 of the guiding ring and is installed between the ring wall 1045 and the positioning seat 1023 of the corresponding joint shaft seat 102. Flexible cable guiding seats 1041 are evenly distributed on the outside of the ring body 1044. In the present invention, the installation angles of the flexible cable guiding rings 104 of two adjacent joint assemblies 1 differ by 10°, so as to stagger the driving flexible cables 4. As Figure 5 shown, each driving flexible cable 4 only passes through the flexible cable guiding ring 104 of the corresponding most distal joint assembly 1 and is fixed to the corresponding most distal joint shaft seat 102. The driving flexible cable 4 does not pass through the flexible cable guiding rings 104 of other joint assemblies 1, but only passes through the rope-passing flanges 103 of other joint assemblies 1. Therefore, the driving flexible cables 4 need to be staggeredly arranged. In this embodiment, there are 6 evenly distributed shaft seat pin holes 1025 on the disk body 1022, and there are 12 unevenly distributed guiding ring pin holes 1042 on the flexible cable guiding ring 104. The pin hole layout of the flexible cable guiding ring 104 is as Figure 15 shown, the distribution radii of the shaft seat pin holes 1025 and the guiding ring pin holes 1042 are the same. In this way, when the relative angle between the flexible cable guiding ring 104 and the joint shaft seat 102 is a multiple of 10° (0°, 10°... 350°, 360°), there are always two pin holes concentric between the joint shaft seat 102 and the flexible cable guiding ring 104. By inserting cylindrical pins into the two concentric pin holes, relative rotation between the flexible cable guiding ring 104 and the joint shaft seat 102 is prevented.

[0041] As Figures 9 to 10 shown, in this embodiment, four fixed head grooves 1027 and four slots 1026 are evenly distributed along the circumferential direction on the positioning seat 1023 of the joint shaft seat 102. Each joint assembly 1 is driven by three driving flexible cables 4, and the flexible cable fixed head 108 at the head end of the driving flexible cable 3 is finally clamped into one of the four fixed head grooves 1027 on the most distal joint shaft seat 102 for fixation.

[0042] The present invention designs the angles, quantity, layout, etc. of the shaft seat pin hole 1025, the guide ring pin hole 1042, the fixing head groove 1027, etc., so that each joint component 1 is independently assembled in a similar manner, and the only difference is the angle of the cable guide ring 104. This allows the present invention to meet the installation requirements of a large number of driving cables 4, while having a small number of parts and high interchangeability, which is convenient for maintenance and repair.

[0043] like Figures 1 to 4 As shown, the connecting rod of the present invention includes two specifications of short connecting rod 2 and long connecting rod 3, wherein the end face of the outer joint shaft seat 102 on the endmost joint assembly 1 of the present invention is fixedly connected to an end flange 5, the end flange 5 is used to install various actuators, and the two connecting rods adjacent to the end flange 5 are both short connecting rods 2, and the remaining connecting rods are long connecting rods 3. The specific specifications and lengths of the connecting rods can be designed according to actual needs.

[0044] like Figure 5 As shown, both ends of the connecting rod are provided with lead holes 6 for circuits or other lines to pass through.

[0045] like Figure 5 As shown, the rope threading flange 103, the flexible rope guide ring 104, and the gasket 105 are respectively mounted on the corresponding joint shaft seat 102, and both ends of the connecting rod are fixedly connected to the end faces of the positioning seat 1023 on the corresponding side joint shaft seat 102, and one end of the connecting rod is abutted against the flexible rope guide ring 104 on the corresponding side joint shaft seat 102, and the other end is abutted against the gasket 105 on the corresponding side joint shaft seat 102.

[0046] The ends of each driving cable 4 are connected to a cable driving device. The driving cables 4 pull the corresponding joint assembly 1 to rotate, thereby realizing the swing of the entire robotic arm. The cable driving device is a well-known technology in the art.

[0047] The working principle of the present invention is:

[0048] The present invention inverts the flexible cable fixing head 108 and embeds it in the corresponding joint shaft seat 102, so that it no longer protrudes from the joint surface, making the joint structure more compact, while also increasing the flexible cable distribution radius, thereby providing a larger flexible cable force arm, improving the load capacity of the robot arm, and increasing the internal wiring space, and increasing the number of driving flexible cables 4 that can be arranged at the joint, thereby allowing the robot arm as a whole to have more joints and improving the flexibility of the robot arm. In addition, the various joint components 1 of the present invention have the same structure, and only the angle of the flexible cable guide ring 104 is different, which not only meets the installation requirements of a large number of driving flexible cables 4, but also makes the present invention have fewer types of parts and higher interchangeability, which is convenient for maintenance and repair.

[0049] like Figures 1 to 7As shown, the driving flexible cable 4 sequentially passes through the cable-passing flanges 104 on each joint assembly 1, and passes through the corresponding guiding-ring flexible cable through-holes 1043 on the flexible cable guiding rings 104 outside the outermost joint axle seat 102, and then is fixed in the corresponding fixed head grooves 1027 on the outermost joint axle seat 102. When the present invention works, every three driving flexible cables 4 pull the corresponding joint assemblies 1 to achieve swinging of three degrees of freedom, and further achieve swinging of the entire robotic arm.

Claims

1. A compact flexible cable-driven robotic arm, characterized in that: It includes a joint assembly (1), a driving flexible cable (4) and a connecting rod. The joint assembly (1) includes a joint shaft bracket (101), a joint shaft seat (102), a rope-passing flange (103) and a flexible cable guiding ring (104). Two joint shaft seats (102) are respectively hinged to both sides of the joint shaft bracket (101), and the end faces of the adjacent side joint shaft seats (102) of adjacent joint assemblies (1) are connected by corresponding connecting rods. Rope-passing flanges (103) are provided on the outer sides of both joint shaft seats (102), and a flexible cable guiding ring (104) is provided on the outer side of one of the rope-passing flanges (103). Flange flexible cable through holes (1031) are evenly distributed on the rope-passing flange (103), and guiding ring flexible cable through holes (1043) are evenly distributed on the flexible cable guiding ring (104). And the flexible cable guiding rings (104) of adjacent joint assemblies (1) are arranged staggeredly. The head end of the driving flexible cable (4) sequentially passes through the corresponding flange flexible cable through holes (1031) on each rope-passing flange (103) of the corresponding joint assemblies (1), and passes through the corresponding guiding ring flexible cable through hole (1043) on the flexible cable guiding ring (104) of the last joint assembly (1). A flexible cable fixing head (108) is provided at the head end of the driving flexible cable (4). A positioning seat (1023) is provided on the joint shaft seat (102), and a fixing head groove (1027) and a slot (1026) communicating with the corresponding fixing head groove (1027) are provided on the positioning seat (1023). The flexible cable fixing head (108) is arranged in the corresponding fixing head groove (1027) on the last joint shaft seat (102), and a flexible cable bending part (401) is formed at the head end of the driving flexible cable (4) and is buried between the flexible cable guiding ring (104) and the corresponding joint shaft seat (102) and passes through the corresponding slot (1026).

2. The compact flexible cable-driven robotic arm according to claim 1, wherein: Mounting holes are provided all around the joint shaft bracket (101). The joint shaft seat (102) includes a disc body (1022). A positioning seat (1023) is provided on one side of the disc body (1022), and an ear plate (1021) is provided on the other side. The ear plate (1021) is rotatably mounted in the mounting hole on the corresponding side of the joint shaft bracket (101) through a mounting pin shaft (107). The rotation axes of the two joint shaft seats (102) are arranged in a cross shape.

3. The compact flexible cable-driven robotic arm according to claim 2, characterized in that: Limit grooves (1024) are provided on both sides of the disc body (1022) of the joint shaft seat (102). Limit blocks (1032) are provided on both sides of the inner hole of the rope-passing flange (103). The rope-passing flange (103) is sleeved on the disc body (1022) of the joint shaft seat (102), and the limit blocks (1032) are clamped in the corresponding limit grooves (1024).

4. The compact flexible cable-driven robotic arm according to claim 2, wherein: A plurality of pedestal pin holes (1025) are provided on the disk body (1022) of the joint axis pedestal (102). The flexible cable guide ring (104) includes a ring body (1044) and a ring wall (1045) provided on the outer edge of the ring body (1044). The ring body (1044) is provided with a plurality of guide ring pin holes (1042). The pedestal pin holes (1025) are concentric with any one of the guide ring pin holes (1042) and are connected by a cylindrical pin.

5. The compact flexible cable-driven robotic arm according to claim 4, wherein: The head end of the driving flexible cable (4) passes through the corresponding guide ring flexible cable through hole (1043) and is arranged between the ring wall (1045) and the outer wall of the positioning seat (1023) of the corresponding joint axis pedestal (102) to form the flexible cable bending part (401).

6. The compact flexible cable-driven robotic arm according to claim 4, characterized in that: Each of the pedestal pin holes (1025) is uniformly distributed along the circumferential direction, and each of the guide ring pin holes (1042) is non-uniformly distributed along the circumferential direction.

7. The compact flexible cable-driven robotic arm according to claim 1, characterized in that: A flexible cable guide seat (1041) is provided outside the flexible cable guide ring (104). The flexible cable guide seat (1041) is internally provided with a guide groove and a guide ring flexible cable through hole (1043) at the bottom.

8. The compact flexible cable-driven robotic arm according to claim 1, characterized in that: A cushion ring (105) is provided on the rope-passing flange (103) on the side of the joint assembly (1) away from the flexible cable guide ring (104).

9. The compact flexible cable-driven robotic arm according to claim 1, wherein: Each joint assembly (1) is driven by three driving flexible cables (4) distributed along the circumferential direction. Four fixed head grooves (1027) and four slots (1026) are evenly distributed along the circumferential direction on the positioning seat (1023) of the joint axis pedestal (102).

10. The compact flexible cable-driven robotic arm according to claim 1, characterized in that: Lead holes (6) are provided at both ends of the connecting rod.

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