Robot finger driving mechanism
By combining guide wheels and traction wheels, the problem of cable wear in chord drive is solved, improving the stability of the cable and the durability of the finger components, making it suitable for robot finger structures.
Patent Information
- Application Number
- CN202520409892.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-03-10
AI Technical Summary
In the chord-driven mode, the chords are prone to wear during movement, affecting the lifespan and stability of the robot's fingers.
The guide wheel and traction wheel combination structure ensures that the pull rope always maintains rolling friction and is fixed to the traction wheel by the locking part. The pull rope is decomposed into multiple sections to increase axial stiffness and reduce wear and deformation.
It improves the stability and lifespan of the pull cord, ensures the stability and durability of the finger component movement, and enables the gripping of heavier objects.
Smart Images
Figure CN223933645U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of robotics, and in particular to a robotic finger structure. Background Technology
[0002] There are various methods for driving robot fingers, including motor-gear drive, pneumatic or hydraulic drive, chord drive, and electromagnetic drive. Among them, chord drive mimics the working principle of human tendons, achieving finger bending and extension by pulling ropes or cables connected to the finger joints. Because this type of drive structure is simple, flexible, and can better simulate human hand movements, it is widely used in the field of robotics.
[0003] However, when the tendon cable is driven, repeated friction occurs during the pulling motion, which can easily lead to wear and tear on the cable, thus affecting its overall service life. Utility Model Content
[0004] In order to solve the problems existing in the prior art, this utility model provides a robot finger drive mechanism with flexible finger component bending and stable and wear-resistant pull rope.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A robotic finger drive mechanism includes a finger assembly rotatably connected to a palm assembly. The finger assembly includes a first phalanx, a second phalanx, and a third phalanx. The first and second phalanxes are rotatably connected via a first pivot, and the second and third phalanxes are rotatably connected via a second pivot. The third phalanx is rotatably connected to the palm assembly via a third pivot. The second phalanx has a first traction wheel, and the third phalanx has a second traction wheel. The second phalanx has a first guide wheel located between the first traction wheel and the first pivot, and the third phalanx has a second guide wheel located between the second traction wheel and the second pivot. The palm assembly contains a third guide wheel. The finger assembly contains a pull rope, the outer end of which is fixedly connected to the first phalanx, and the inner end of which passes through the first guide wheel, the first traction wheel, the second guide wheel, the second traction wheel, and the third guide wheel. The palm assembly contains a traction mechanism connected to and driving the inner end of the pull rope to extend and retract. The finger assembly contains an elastic reset component that drives the finger assembly to reset.
[0007] By adopting the above technical solution, the path that the pull rope travels along is respectively through the first guide wheel, the first traction wheel, the second guide wheel, the second traction wheel, and the third guide wheel. That is, the pull rope and the wheels always maintain rolling friction, the pull rope is not easy to wear or jam, the movement of the pull rope is more stable, and thus the movement of the finger component is also more stable.
[0008] Preferably, the first traction wheel is provided with a first locking part for locking the pull rope to the first traction wheel, and the second traction wheel is provided with a second locking part for locking the pull rope to the second traction wheel; when the finger assembly is in any state, the two ends of the pull rope that contact the first traction wheel are always tangent to the first traction wheel, and the two ends of the pull rope that contact the second traction wheel are always tangent to the second traction wheel. The pull rope is fixed to the first traction wheel via the first locking part and to the second traction wheel via the second locking part. This serves two purposes: firstly, it prevents the pull rope from undergoing elastic deformation under tension and moving relative to the first and second traction wheels, thus further preventing rope wear; secondly, fixing the pull rope to the first and second traction wheels via the first and second locking parts is equivalent to dividing the pull rope into three independent segments, each with a significantly shorter length. This increases the axial stiffness k value of the pull rope (k=EA / L, where E is the elastic modulus, L is the length of the pull rope, and A is the cross-sectional area of the pull rope), meaning the rigidity of the pull rope increases. Therefore, the absolute deformation ΔL produced under the same tension F is smaller (ΔL = FL / EA). Consequently, under dynamic or vibrational loads, the shorter rope is less prone to deformation or vibration, further improving the stability of the pull rope.
[0009] Preferably, the first locking part is configured as a first pressure block, which presses the pull rope onto the first traction wheel and locks it with bolts; the second locking part is configured as a second pressure block, which presses the pull rope onto the second traction wheel and locks it with bolts.
[0010] Preferably, when the finger assembly is in the extended state, the pull cord between the first phalanx and the first guide wheel is located on the side of the first pivot facing the fingertip, the pull cord between the first traction wheel and the second guide wheel is located on the side of the second pivot facing the fingertip, and the pull cord between the second traction wheel and the third guide wheel is located on the side of the third pivot facing the fingertip. This ensures that when the pull cord is pulled, each phalanx can stably bend towards the side of the fingertip.
[0011] Preferably, when the finger assembly is in the extended state, the lower end of the back of the first phalanx abuts against the upper end of the back of the second phalanx, the lower end of the back of the second phalanx abuts against the upper end of the back of the third phalanx, and the lower end of the back of the third phalanx abuts against the palm assembly. This arrangement ensures that the finger assembly has a unique state when extended, that is, ensures that the initial state of the finger assembly is unique, which facilitates control.
[0012] Preferably, the traction mechanism includes a movable pulley, a traction rope, and a traction power source. The movable pulley is rotatably mounted within a wheel seat. The inner end of the traction rope is fixedly connected to the wheel seat. One end of the traction rope passes over the movable pulley and connects to the hand assembly, while the other end of the traction rope is connected to the traction power source. The traction power source causes the inner end of the traction rope to extend and retract, thereby enabling the finger assembly to bend and extend. The traction rope, in conjunction with the movable pulley, reduces the load on the traction power source to half the tension of the traction rope, thus allowing this finger structure to grasp heavier objects.
[0013] Preferably, the elastic reset component is configured as an elastic cable assembly, the traction power is configured as a double-acting linear actuator, the palm assembly has a fixed pulley, and the other end of the traction rope passes over the fixed pulley and is connected to one end of the double-acting linear actuator; the elastic cable assembly is located on the back of the finger of the finger assembly, the outer end of the elastic cable assembly is fixedly connected to the first phalanx, and the inner end of the elastic cable assembly is connected to the other end of the double-acting linear actuator.
[0014] Preferably, the elastic reset component is configured as an elastic cable component, with the outer end of the elastic cable component fixedly connected to the first phalanx and the inner end of the elastic cable component fixedly connected to the palm component.
[0015] Preferably, the elastic reset component is configured as a plurality of elastic cable components, wherein the first phalanx, the second phalanx, and the third phalanx are each connected to the palm component through an independent elastic cable component.
[0016] Preferably, the elastic reset component is configured as several tension springs between the backs of adjacent phalanges, and a tension spring is also provided between the third phalanx and the palm assembly. Tension springs with different stiffness coefficients can be configured according to actual needs to meet the reset requirements of phalanges in different locations.
[0017] Therefore, the present invention has the following beneficial effects: (1) The pull rope always maintains rolling friction during the movement process, the pull rope is not easy to wear and has a long service life; (2) The pull rope is locked on the first traction wheel and the second traction wheel respectively, on the one hand, to prevent the pull rope from moving relative to the first traction wheel and the second traction wheel due to axial deformation, and further to prevent the pull rope from wearing; on the other hand, a long pull rope is decomposed into three short pull ropes, which improves the axial stiffness of the pull rope, reduces the absolute deformation of the pull rope, and further improves the overall stability. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of one structure of the present utility model.
[0019] Figure 2 for Figure 1 Another perspective view.
[0020] Figure 3 This is a schematic diagram of the bent state of the finger component.
[0021] Figure 4 for Figure 1 Exploded view.
[0022] Figure 5 This is a schematic diagram of the finger component in an upright position.
[0023] Figure 6 This is a schematic diagram showing the state of the finger assembly during the bending process.
[0024] Figure 7 This is a schematic diagram of the finger assembly in a fully bent state.
[0025] Figure 8 This is the second connection method for the elastic cable assembly.
[0026] Figure 9 This is the third connection method for elastic cable assemblies.
[0027] Figure 10 A connection diagram showing the elastic reset element configured as a tension spring. Detailed Implementation
[0028] To make the technical problem to be solved, the technical solution, and the beneficial technical effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the scope of protection of the present utility model.
[0029] It should be understood that the terms "first," "second," etc., used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may expressly or implicitly indicate that at least one of those features is included.
[0030] like Figures 1-7The illustrated robotic finger drive mechanism includes a finger assembly 20 rotatably connected to a palm assembly 10. The finger assembly 20 includes a first phalanx 200, a second phalanx 201, and a third phalanx 202. The first phalanx 200 and the second phalanx 201 are rotatably connected via a first pivot 30, the second phalanx 201 and the third phalanx 202 are rotatably connected via a second pivot 31, and the third phalanx 202 is rotatably connected to the palm assembly 10 via a third pivot 32. A first traction wheel 40 is provided on the second phalanx 201, and a second traction wheel 41 is provided on the third phalanx 202. The second phalanx 201 is positioned between the first traction wheel 40 and the first pivot 30. The hand assembly 10 is equipped with a first guide wheel 50, and the third finger joint 202 is equipped with a second guide wheel 51 located between the second traction wheel 41 and the second pivot 31. The palm assembly 10 is equipped with a third guide wheel 52. The finger assembly 20 is equipped with a pull rope 21. The outer end of the pull rope 21 is fixedly connected to the first finger joint 200, and the inner end of the pull rope 21 passes through the first guide wheel 50, the first traction wheel 40, the second guide wheel 51, the second traction wheel 41, and the third guide wheel 52. The palm assembly 10 is equipped with a traction mechanism 60 that is connected to the inner end of the pull rope 21 and drives the inner end of the pull rope 21 to extend and retract. The finger assembly 20 is equipped with an elastic reset component 70 that drives the finger assembly 20 to reset.
[0031] like Figure 1 As shown, the first traction wheel 40 is provided with a first locking part 400 for locking the pull rope 21 to the first traction wheel 40, and the second traction wheel 41 is provided with a second locking part 410 for locking the pull rope 21 to the second traction wheel 41. When the finger assembly 20 is in any state, the two ends of the pull rope 21 that contact the first traction wheel 40 are always tangent to the first traction wheel 40, and the two ends of the pull rope 21 that contact the second traction wheel 41 are always tangent to the second traction wheel 41. In some embodiments, snap-fit grooves are directly provided on the first traction wheel 40 and the second traction wheel 41 to secure the pull rope; in other embodiments, the pull rope is directly welded to the first traction wheel and the second traction wheel. In this embodiment, as shown... Figure 4 As shown, the first locking part 400 is configured as a first pressure block 401, which presses the pull rope 21 onto the first traction wheel 40 and locks it with bolts; the second locking part 410 is configured as a second pressure block 411, which presses the pull rope 21 onto the second traction wheel 41 and locks it with bolts.
[0032] like Figure 5As shown, when the finger assembly 20 is in the extended state, the lower end of the back of the first phalanx 200 abuts against the upper end of the back of the second phalanx 201, the lower end of the back of the second phalanx 201 abuts against the upper end of the back of the third phalanx 202, and the lower end of the back of the third phalanx 202 abuts against the palm assembly 10. In the extended state, the pull cord 21 between the first phalanx 200 and the first guide wheel 50 is located on the side of the first pivot 30 facing the fingertip, the pull cord 21 between the first traction wheel 40 and the second guide wheel 51 is located on the side of the second pivot 31 facing the fingertip, and the pull cord 21 between the second traction wheel 41 and the third guide wheel 52 is located on the side of the third pivot 32 facing the fingertip. This allows a stable torque to be generated when the pull cord is tightened, causing the finger assembly to bend towards the fingertip.
[0033] like Figure 4 and Figure 5 As shown, the traction mechanism 60 includes a movable pulley 600, a traction rope 601, and a traction power source 602. The movable pulley 600 is rotatably mounted inside a wheel seat 603. The inner end of the traction rope 21 is fixedly connected to the wheel seat 603. One end of the traction rope 601 passes around the movable pulley 600 and is connected to the hand assembly 10. The other end of the traction rope 601 is connected to the traction power source 602. In some embodiments, the traction power source 602 is configured as any one of an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder.
[0034] The elastic reset component 70 is configured as an elastic cable assembly 700, and the traction power 602 is configured as a double-acting linear actuator. A fixed pulley 604 is provided inside the palm assembly 10, and the other end of the traction rope 601 passes over the fixed pulley 604 and is connected to one end of the double-acting linear actuator. The elastic cable assembly 700 is located on the back of the finger of the finger assembly 20, with its outer end fixedly connected to the first phalanx 200 and its inner end connected to the other end of the double-acting linear actuator. In some embodiments, the double-acting linear actuator is either a double-headed screw motor or a double-headed cylinder; in this embodiment, a double-headed screw motor is used.
[0035] like Figure 8 The second connection method of the elastic cable assembly is shown. Specifically, the elastic reset assembly 70 is configured as an elastic cable assembly 700. The outer end of the elastic cable assembly 700 is fixedly connected to the first phalanx 200, and the inner end of the elastic cable assembly 700 is fixedly connected to the palm assembly 10.
[0036] like Figure 9 The third connection method of the elastic cable assembly is shown. Specifically, the elastic reset assembly 70 is configured as a plurality of elastic cable assemblies 700. The first phalanx 200, the second phalanx 201, and the third phalanx 202 are all connected to the palm assembly 10 through independent elastic cable assemblies 700.
[0037] The elastic cable assembly 700 can be made of a single elastic cable, a single spring, or a combination of spring and cable (which can be elastic or non-elastic).
[0038] like Figure 10 The diagram shows a connection of elastic reset components configured as tension springs. Specifically, the elastic reset component 70 is configured as several tension springs 701 located between the backs of adjacent phalanges, and tension springs 701 are also located between the third phalanx 202 and the palm component 10.
[0039] Referring to the accompanying drawings, the principle of this utility model is as follows: Figure 5-7 As shown, the pull rope maintains rolling friction with the first guide wheel 50, the first traction wheel 40, the second guide wheel 51, the second traction wheel 41, and the third guide wheel 52 throughout the tightening and releasing process, ensuring smooth movement and minimal wear. Furthermore, regardless of the finger assembly's position, the pull rope remains in contact with all four wheels, preventing separation. Therefore, vibration during pull rope movement is minimal and negligible, enhancing its stability. Because the pull rope interacts with the first and second traction wheels... Since it is in a fixed state, even if the rope undergoes slight elastic deformation when tightened, it will not rub against the first and second traction wheels, further reducing rope wear. Simultaneously, the rope is fixed to the first and second traction wheels via the first and second locking parts, effectively dividing the rope into three independent segments. The length of each segment is significantly shortened, thereby increasing the axial stiffness k value of the rope, k=EA / L, where E is the elastic modulus, L is the rope length, and A is the rope cross-sectional area. This means the rope's rigidity is increased, resulting in a smaller absolute deformation ΔL under the same tension F, ΔL = FL / EA. Consequently, under dynamic or vibrational loads, this type of rope is less prone to deformation or vibration, further improving its stability.
[0040] In the description of this utility model, it should be understood that the directions or positional relationships indicated by up, down, left, right, inner end, outer end, one end, and the other end are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of more clearly describing the technical solution of this utility model, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as a limitation of this utility model.
[0041] Although specific embodiments of the present invention are described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the present invention. Various substitutions, alterations, and modifications may be conceived without departing from the spirit and scope of the present invention.
Claims
1. A robotic finger drive mechanism, comprising a finger assembly (20) rotatably connected to a palm assembly (10), characterized in that, The finger assembly (20) includes a first phalanx (200), a second phalanx (201), and a third phalanx (202). The first phalanx (200) and the second phalanx (201) are rotatably connected by a first pivot (30), the second phalanx (201) and the third phalanx (202) are rotatably connected by a second pivot (31), and the third phalanx (202) is rotatably connected to the palm assembly (10) by a third pivot (32). The second phalanx (201) is provided with a first traction wheel (40), the third phalanx (202) is provided with a second traction wheel (41), the second phalanx (201) is provided with a first guide wheel (50) located between the first traction wheel (40) and the first pivot (30), the third phalanx (202) is provided with a second guide wheel (51) located between the second traction wheel (41) and the second pivot (31), and the palm assembly (10) is provided with a third guide wheel (52). The finger assembly (20) is provided with a pull rope (21), the outer end of which is fixedly connected to the first phalanx (200), and the inner end of which passes through the first guide wheel (50), the first traction wheel (40), the second guide wheel (51), the second traction wheel (41), and the third guide wheel (52); the palm assembly (10) is provided with a traction mechanism (60) that is connected to the inner end of the pull rope (21) and drives the inner end of the pull rope (21) to extend and retract; the finger assembly (20) is provided with an elastic reset assembly (70) that drives the finger assembly (20) to reset.
2. The robot finger driving mechanism according to claim 1, characterized in that, The first traction wheel (40) is provided with a first locking part (400) for locking the pull rope (21) to the first traction wheel (40), and the second traction wheel (41) is provided with a second locking part (410) for locking the pull rope (21) to the second traction wheel (41). When the finger assembly (20) is in any state, the two ends of the pull rope (21) that are in contact with the first traction wheel (40) are always tangent to the first traction wheel (40), and the two ends of the pull rope (21) that are in contact with the second traction wheel (41) are always tangent to the second traction wheel (41).
3. The robot finger driving mechanism according to claim 2, characterized in that, The first locking part (400) is configured as a first pressure block (401), which presses the pull rope (21) onto the first traction wheel (40) and locks it with bolts; the second locking part (410) is configured as a second pressure block (411), which presses the pull rope (21) onto the second traction wheel (41) and locks it with bolts.
4. A robot finger driving mechanism according to claim 1, 2, or 3, characterized in that, When the finger assembly (20) is in the extended state, the pull cord (21) between the first knuckle (200) and the first guide wheel (50) is located on the side of the first pivot (30) facing the fingertip, the pull cord (21) between the first traction wheel (40) and the second guide wheel (51) is located on the side of the second pivot (31) facing the fingertip, and the pull cord (21) between the second traction wheel (41) and the third guide wheel (52) is located on the side of the third pivot (32) facing the fingertip.
5. A robot finger driving mechanism according to claim 4, characterized in that, When the finger assembly (20) is in an extended state, the lower end of the back of the first phalanx (200) abuts against the upper end of the back of the second phalanx (201), the lower end of the back of the second phalanx (201) abuts against the upper end of the back of the third phalanx (202), and the lower end of the back of the third phalanx (202) abuts against the palm assembly (10).
6. A robotic finger driving mechanism according to claim 1 or 2, characterized in that, The traction mechanism (60) includes a movable pulley (600), a traction rope (601), and a traction power (602). The movable pulley (600) is rotatably mounted inside a wheel seat (603). The inner end of the pull rope (21) is fixedly connected to the wheel seat (603). One end of the traction rope (601) passes around the movable pulley (600) and is connected to the hand assembly (10). The other end of the traction rope (601) is connected to the traction power (602).
7. A robot finger driving mechanism according to claim 6, characterized in that, The elastic reset component (70) is configured as an elastic cable component (700), the traction power (602) is configured as a double-acting linear actuator, the palm component (10) is provided with a fixed pulley (604), and the other end of the traction rope (601) passes around the fixed pulley (604) and is connected to one end of the double-acting linear actuator; The elastic cable assembly (700) is disposed on the back of the finger of the finger assembly (20). The outer end of the elastic cable assembly (700) is fixedly connected to the first phalanx (200), and the inner end of the elastic cable assembly (700) is connected to the other end of the double-acting linear actuator.
8. A robot finger driving mechanism according to claim 1 or 2, characterized in that, The elastic reset component (70) is configured as an elastic cable component (700), the outer end of which is fixedly connected to the first phalanx (200), and the inner end of which is fixedly connected to the palm component (10).
9. A robot finger driving mechanism according to claim 1 or 2, characterized in that, The elastic reset component (70) is configured as a plurality of elastic cable components (700), wherein the first phalanx (200), the second phalanx (201), and the third phalanx (202) are all connected to the palm component (10) through independent elastic cable components (700).
10. A robot finger driving mechanism according to claim 1 or 2, characterized in that, The elastic reset component (70) is configured as a plurality of tension springs (701) between the backs of adjacent phalanges, and a tension spring (701) is also provided between the third phalanx (202) and the palm component (10).