Mechanical hand driving structure

Abstract

The utility model relates to a kind of mechanical hand driving structure, including arm and palm, arm outside is provided with palm, palm is connected with multiple knuckles, the junction of arm and palm is equipped with lateral stabilizing layer, palm front side is equipped with extensor layer, flexor layer is connected between palm and knuckle, the position of arm close to palm is equipped with lever structure, pulley block is built-in in lever structure.The utility model is provided with asymmetric lever mechanism in palm near palm, shape memory alloy wire is connected in short arm end, driving steel wire is connected in long arm end, lever principle is used, shape memory alloy wire tiny original contraction displacement is effectively enlarged, the demand that knuckle is bent substantially is met;And pulley block is built-in in lever structure, effectively change transmission path and reduce the friction loss of steel wire, improve energy transmission efficiency from driver to joint.

Description

Technical Field

[0001] This utility model belongs to the field of robotic arm technology, specifically relating to a robotic arm drive structure. Background Technology

[0002] Currently, SMA-based mechanical finger driving solutions are mainly divided into two categories: direct implantation and wire-pulling.

[0003] The direct implantation method involves fixing SMA wires directly to the joints of the finger. They are usually arranged parallel to the phalanges as "artificial muscles". When the SMA is heated by electricity, it undergoes an austenitic phase transformation, resulting in contraction and deformation, which directly pulls the joint to bend. After the power is turned off and the finger is cooled, the finger straightens by the restoring force of passive elastic elements (such as springs or flexible materials).

[0004] The cable-driven method borrows from the traditional tendon cable transmission concept, placing SMA wires as actuators in the palm or forearm. The contraction of the wires pulls the tendon cables, thereby driving the movement of the distal finger joints.

[0005] In practical applications, the intrinsic recoverable strain of NiTi SMA filaments is typically only 4% to 8%. For finger joints that require large rotation angles, this small stroke is severely insufficient. Furthermore, SMA filaments will experience fatigue failure under repeated thermal cycling, greatly reducing their service life. At the same time, the operating frequency of the actuator is limited by its cooling rate. The slow cooling process will directly cause sluggish finger movements, limiting the robot's dynamic operation performance and making it difficult for it to complete fast and continuous grasping tasks. Utility Model Content

[0006] The purpose of this invention is to provide a robotic arm drive structure to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a robotic hand drive structure, comprising an arm and a palm, wherein the palm is rotatably provided on the outer side of the arm, and the palm is connected to multiple finger joints, characterized in that a lateral stabilizing layer is provided at the connection between the arm and the palm, an extensor muscle layer is provided on the front side of the palm, a flexor muscle layer is connected between the palm and the finger joints, and a lever structure is provided on the arm near the palm, wherein the lever structure has a built-in pulley assembly.

[0008] Preferably, the lever structure has a long arm and a short arm, the long arm being connected to the flexor muscle layer.

[0009] Preferably, the arm is provided with a base, and a Ni Ti-SMA wire is connected to the base, with the other end of the Ni Ti-SMA wire connected to the short arm.

[0010] Preferably, the surface of the NiTi-SMA filament is coated with a highly thermally conductive material.

[0011] Preferably, the flexor layer, extensor layer, and lateral stabilizing layer are all made of steel wire.

[0012] Preferably, a driver is provided on the arm at a position on one side of the base, and a communication interface is provided on the rear side of the driver.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This invention features an asymmetric lever mechanism near the palm, connecting the Ni Ti-SMA wire to the short arm and the drive wire to the long arm. By utilizing the lever principle, the small original contraction displacement of the Ni Ti-SMA wire is effectively amplified to meet the needs of the finger joints for large-amplitude bending movements.

[0015] Furthermore, the built-in pulley system in the lever structure effectively changes the transmission path and reduces the friction loss of the steel wire, thereby improving the energy transfer efficiency from the actuator to the joint.

[0016] This invention involves directly attaching a high thermal conductivity material to the surface of a NiTi-SMA filament to improve its heat dissipation efficiency and shorten its cooling and reset time, thereby increasing the driving frequency and movement speed of the entire finger and enhancing the dynamic performance of the robot in performing fast and continuous grasping tasks.

[0017] In this invention, the heavy and heat sources, such as Ni Ti-SMA wire and driver, are concentrated in the arm part, while the transmission mechanism is distributed in the palm and fingers. This effectively reduces the weight and inertia of the hand body, making the finger movement lighter and more flexible, and also avoids interference from the driver to the grasping operation. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 This is a partial sectional view of the present invention;

[0020] Figure 3 This is a partial three-dimensional structural schematic diagram of the present invention;

[0021] Figure 4 This is a three-dimensional structural diagram of the driver in this utility model.

[0022] Numbering in the diagram: 1-arm, 2-palm, 3-finger joint, 4-lateral stabilizing layer, 5-extensor layer, 6-flexor layer, 7-lever structure, 71-long arm, 72-short arm, 8-pulley system, 9-base, 10-Ni Ti SMA wire, 11-interface, 12-driver, 13-communication interface. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example 1

[0025] like Figures 1 to 4 The illustrated robotic hand drive structure includes an arm 1 and a hand 2. The hand 2 is rotatably mounted on the outer side of the arm 1, and the hand 2 is connected to multiple finger joints 3. A lateral stabilizing layer 4 is provided at the connection between the arm 1 and the hand 2. An extensor muscle layer 5 is provided on the front side of the hand 2, and a flexor muscle layer 6 is connected between the hand 2 and the finger joints 3. The lateral stabilizing layer 4 and the extensor muscle layer 5 converge at the flexor muscle layer 6. A lever structure 7 is provided on the arm 1 near the hand 2, and a pulley assembly 8 is built into the lever structure 7. The lever structure 7 has a long arm 71 and a short arm 72, and the long arm 71 is connected to the flexor muscle layer 6. A base 9 is provided on the arm 1, and a NiTi-SMA wire 10 is connected to the base 9. The other end of the NiTi-SMA wire 10 is connected to the short arm 72. A high thermal conductivity material is attached to the surface of the NiTi-SMA wire 10. The flexor muscle layer 6, the extensor muscle layer 5, and the lateral stabilizing layer 4 are all made of steel wire. An actuator 12 is provided on the arm 1 on one side of the base 9, and a communication interface 13 is provided on the rear side of the actuator 12.

[0026] This invention features an asymmetric lever mechanism near the palm of the hand 2, connecting a NiTi-SMA wire 10 to the short arm 72 and a drive wire to the long arm 71. Utilizing the lever principle, the small, inherent contraction displacement of the NiTi-SMA wire 10 is effectively amplified to meet the demands of the finger joint 3 for large-amplitude bending movements. Furthermore, a pulley system 8 is built into the lever structure 7, effectively altering the transmission path and reducing frictional loss of the wire, thereby improving the energy transfer efficiency from the actuator 12 to the joint. This invention also directly attaches a high thermal conductivity material to the surface of the NiTi-SMA wire 10 to enhance its heat dissipation efficiency and shorten its cooling and reset time, thus increasing the driving frequency and movement speed of the entire finger and enhancing the robot's dynamic performance in performing rapid, continuous grasping tasks. In this invention, NiTi-SMA wire 10 is used to... The heavy and heat sources, such as the Ti-SMA wire 10 and the actuator 12, are concentrated in the arm 1 part, while the transmission mechanism is distributed in the palm 2 and fingers. This effectively reduces the weight and inertia of the hand body, making the finger movement lighter and more flexible, and also avoids interference of the actuator 12 with the grasping operation.

[0027] Example 2

[0028] like Figures 1 to 4 The illustrated robotic hand drive structure includes an arm 1 and a hand 2. The outer side of the arm 1 is connected to the hand 2 via a revolute joint. Multiple finger joints extend from the front end of the hand 2, forming a complete robotic finger. During operation, the user can control the arm 1, hand 2, and each finger joint through the drive system to complete multi-degree-of-freedom coordinated movements, achieving various dexterous operations such as grasping, holding, and releasing.

[0029] In this embodiment, a lateral stabilizing layer 4 is specially provided at the connection between the arm 1 and the palm 2 to resist non-axial loads. An extensor layer 5 is arranged on the front side of the palm 2, while the palm 2 and the finger joint 3 are connected by a flexor layer 6. The steel wires of the lateral stabilizing layer 4 and the extensor layer 5 converge in the region of the flexor layer 6.

[0030] All three layers are made of high-strength steel wire and achieve coordinated movement through precise tension control: when the flexor layer 6 steel wire is pulled, the fingers bend to complete the grasping task; when the stretcher layer 5 steel wire is pulled, the fingers straighten and return to their original position to release the object; while the lateral stabilizing layer 4 can effectively suppress the lateral swing and torsion of the finger joints 3 when subjected to force, ensuring the accuracy of the operation.

[0031] The arm 1 is equipped with shape memory alloy (Ni Ti-SMA) wire. A lever structure 7 designed near the palm of the arm 1 converts the small displacement output of the Ni Ti-SMA wire 10 into a large displacement that meets the movement requirements of the finger joints 3. Specifically, the lever structure 7 adopts an asymmetrical design with a short arm 72 and a long arm 71. The short arm 72 is connected to the Ni Ti-SMA wire 10, while the long arm 71 is connected to the flexor layer 6 wire. When the Ni Ti-SMA wire 10 contracts due to heat, the lever principle amplifies the minute displacement, thereby enabling the fingers to complete the required bending angle. Simultaneously, a terminal block is provided on the base 9. One end of the Ni Ti-SMA wire 10 is fixed to this terminal block via a threaded conductive clip, while the other end is connected to the short arm 72 of the lever structure via a quick-release clip, allowing for convenient replacement of the Ni Ti-SMA wire.

[0032] To further optimize transmission performance, a pulley block 8 is also built between the lever mechanism and the Ni Ti-SMA wire 10. The pulley block 8 can not only change the direction of force transmission, but also significantly reduce the friction loss between the steel wire and the structural components, thereby improving energy transmission efficiency.

[0033] Furthermore, the Ni Ti-SMA wire 10 needs to be heated by electricity to trigger the martensitic phase transformation and thus shrink. The reset after shrinkage requires sufficient heat dissipation. Therefore, a layer of highly thermally conductive material, such as a graphene film or a copper alloy heat sink, is attached to the surface of the Ni Ti-SMA wire 10. The above materials can significantly accelerate the heat dissipation speed of the Ni Ti-SMA wire 10, thereby increasing the driving frequency and making finger movements faster.

[0034] Example 3

[0035] like Figures 1 to 4 The robotic arm drive structure shown has a standardized interface 11 on the side of the arm 1 base. The modular driver 12 can be quickly installed through the interface 11. The interface 11 adopts a quick-release ring connection method, and the driver 12 can be locked or released by simply rotating a certain angle, so as to realize the quick replacement and maintenance of the drive unit.

[0036] Once the driver 12 is installed, its output shaft automatically maintains precise alignment with the Ni Ti-SMA wire 10, ensuring the linearity of power transmission. Furthermore, in this embodiment, the two drive sources, the Ni Ti-SMA wire 10 and the driver 12, are concentrated in the arm 1 part, while the transmission components such as levers and layers of steel wires are distributed in the palm 2 and finger joints 3. This can reduce the weight and volume of the hand body, making finger movements lighter and faster, and preventing the driver 12 from hindering operation when grasping.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A robotic hand drive structure, comprising an arm and a hand, wherein the hand is rotatably mounted on the outer side of the arm, and the hand is connected to a plurality of finger joints, characterized in that, A lateral stabilizing layer is provided at the connection between the arm and the palm, an extensor layer is provided on the front side of the palm, a flexor layer is provided between the palm and the finger joints, and a lever structure is provided on the arm near the palm, with a pulley assembly built into the lever structure.

2. The robotic arm drive structure according to claim 1, characterized in that, The lever structure has a long arm and a short arm, with the long arm connected to the flexor muscle layer.

3. The robotic arm drive structure according to claim 2, characterized in that, The arm is provided with a base, and a Ni Ti-SMA wire is connected to the base. The other end of the Ni Ti-SMA wire is connected to the short arm.

4. The robotic arm drive structure according to claim 3, characterized in that, The surface of the NiTi-SMA wire is coated with a highly thermally conductive material.

5. The robotic arm drive structure according to claim 1, characterized in that, The flexor layer, extensor layer, and lateral stabilizing layer are all made of steel wire.

6. The robotic arm drive structure according to claim 3, characterized in that, A driver is provided on one side of the base on the arm, and a communication interface is provided on the rear side of the driver.

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