High-precision torsion rope driving mechanism based on segmented retainer

Abstract

The application discloses a high-precision torsion rope driving mechanism based on segmented retainer, which comprises a driving connecting frame and a free end joint, the inner side of the driving connecting frame is fixedly connected with a driving motor, elastic reset members are arranged in an array between the driving motor and the free end joint, retainers are arranged between every two elastic reset members, and a plurality of torsion ropes are further arranged between the driving motor and the free end joint, and the plurality of torsion ropes are radially isolated from each other through the retainers. The high-precision torsion rope driving mechanism based on segmented retainer radially isolates the plurality of torsion ropes through segmented retainers, avoids deformation of the torsion ropes caused by mutual extrusion, determines system transmission relationship by geometric structure, and improves the precision and stability problems caused by nonlinear coupling. Meanwhile, direct friction between the torsion ropes is changed into contact between the torsion ropes and the retainers, friction loss is reduced, and operation stability and service life of the mechanism are improved.

Description

Technical Field

[0001] This invention relates to the field of torsion rope actuator technology, specifically a high-precision torsion rope drive mechanism based on a segmented retainer. Background Technology

[0002] Traditional torsion rope drive systems use a motor to drive ropes to intertwine, converting rotational torque into linear tension. During operation, the ropes come into direct contact and compress against each other, resulting in compression deformation. This deformation varies with the load and torsion angle, causing the system to exhibit complex nonlinear coupling characteristics, affecting transmission accuracy and stability. Furthermore, direct friction between the ropes reduces transmission efficiency and affects service life. Additionally, traditional structures can only achieve contraction and pulling, making it difficult for the ropes to autonomously recover their extended state. Summary of the Invention

[0003] The purpose of this invention is to provide a high-precision torsion rope drive mechanism based on a segmented retainer to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-precision twisted rope drive mechanism based on a segmented retainer, comprising a drive connecting frame and a free end connector. A drive motor is fixedly connected to the inner side of the drive connecting frame. Elastic reset members are arranged in an array between the drive motor and the free end connector. A retainer is provided between every two elastic reset members. Multiple twisted ropes are also provided between the drive motor and the free end connector, and each twisted rope passes through the retainer sequentially. The multiple twisted ropes are radially isolated from each other by the retainer and twist and contract synchronously. The retainer and the elastic reset members are covered with an anti-torsion cover, and the two ends of the anti-torsion cover are fixedly connected to the drive connecting frame and the free end connector, respectively.

[0005] Preferably, a first outer cover connector is sleeved on the outer wall of the drive connecting frame, and a first slot is formed between the first outer cover connector and the drive connecting frame; a second outer cover connector is sleeved on the outer wall of the free end connector, and a second slot is formed between the free end connector and the second outer cover connector; the two ends of the anti-torsion outer cover are respectively inserted into the first slot and the second slot.

[0006] Preferably, the anti-torsion cover is made of rigid material at both ends and nylon braided mesh in the middle.

[0007] Preferably, a first ridge joint is fixedly connected to the output end of the drive motor, and one end of the twisted rope is fixedly connected to the first ridge joint; a second ridge joint is provided on the free end joint, and the second ridge joint is fixedly connected to the other end of the twisted rope.

[0008] Preferably, the retainer has evenly spaced threading holes for the twisted rope to pass through, the threading holes are symmetrically distributed along the circumference of the retainer, and the edges of the threading holes are rounded.

[0009] Preferably, the elastic reset element is a compression spring.

[0010] Preferably, an encoder is provided on the second ridge joint, and a radial magnet is provided on the cage adjacent to the second ridge joint.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This high-precision torsion rope drive mechanism based on a segmented cage radially isolates multiple torsion ropes, preventing deformation caused by mutual compression. This allows the system's transmission relationship to be determined by geometry, improving accuracy and stability issues arising from nonlinear coupling. The anti-torsion outer casing, in conjunction with an elastic reset component, provides a relaxation restoring force, enabling the drive mechanism to reliably return to its extended state, achieving a reliable cycle of contraction and extension. Simultaneously, it transforms the direct friction between the torsion ropes into contact between the torsion ropes and the cage, reducing frictional loss and improving the mechanism's operational stability and service life. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the rope twisting drive mechanism in a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the rope-twisting drive mechanism in a preferred embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of the retainer and the twisted rope in a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the first vertebral joint in a preferred embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the cage and the elastic reset member in a preferred embodiment of the present invention; Figure 6 This is a schematic diagram of the cage structure in a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the second vertebral joint in a preferred embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the free end connector and the second ridge connector in a preferred embodiment of the present invention.

[0013] In the figure: 1. Drive connecting frame, 2. First outer cover connector, 3. Anti-torsion outer cover, 4. Free end connector, 5. Cage, 6. Elastic reset component, 7. Second ridge joint, 8. Twisted rope, 9. First ridge joint, 10. Drive motor, 11. First slot, 12. Second slot, 13. Second outer cover connector. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Please see Figure 1-8 The present invention provides a technical solution: A high-precision twisted rope drive mechanism based on a segmented retainer includes a drive connecting frame 1 and a free end connector 4. A drive motor 10 is fixedly connected to the inner side of the drive connecting frame 1. Elastic reset members 6 are arranged in an array between the drive motor 10 and the free end connector 4 to restore the twisted rope drive mechanism to its extended state. A retainer 5 is provided between every two elastic reset members 6. At least three symmetrically placed twisted ropes 8 are also provided between the drive motor 10 and the free end connector 4, and each twisted rope 8 passes through the retainer 5 sequentially. All twisted ropes 8 are radially isolated from each other by the retainer 5 and twist and contract synchronously. The outer walls of the retainer 5 and the elastic reset members 6 are covered with an anti-torsion cover 3, and the two ends of the anti-torsion cover 3 are fixedly connected to the drive connecting frame 1 and the free end connector 4, respectively.

[0016] By introducing a segmented circular retainer 5, the traditional "twisted rope nonlinear coupling" is transformed into a geometrically determined polygonal mechanism series model.

[0017] According to the equivalent kinematic model, the contraction amount of a single segment The radial distance of the torsion rope depends on the cage limit. Total output length The formula is as follows:

[0018] Traditional TSAs have a shrinkage rate of only 10%-20% before over-winding, while this structure effectively avoids physical interference between the twisted ropes by segmenting constraints, achieving a shrinkage rate of nearly 50% in Matlab simulations and actual measurements.

[0019] Neglecting the higher-order inertial terms of the lightweight torsion rope, the system's Lagrangian mainly consists of the rotational kinetic energy at the input and the elastic potential energy at the output. By differentiating the total contraction with respect to the input angle... The transmission Jacobian matrix of the system can be obtained. Furthermore, output force With input torque The mapping relationship can be represented as: (in (This is the equivalent moment of inertia of the motor rotor and cage system).

[0020] In traditional TSA systems, due to the compression and flattening of the twisted rope, the transmission Jacobian matrix is ​​a nonlinear black box containing random variables. However, the novel TSA structure in this proposal, through piecewise constraints, makes the Jacobian matrix a completely purely geometric deterministic function. At the beginning of the mechanism's contraction action, due to... The system is extremely small, and has a significant torque (tension) gain effect, which theoretically proves the feasibility of the mechanism to output large tension in a very small space.

[0021] Frictional force conversion: Traditional TSA is a "soft-to-soft" friction, with a high coefficient of friction (0.1~0.15) and is prone to generating heat, which leads to fiber thermal shrinkage (about 10%).

[0022] Static friction replacement: The “soft against hard” contact mode is adopted, and the holes of the torsion rope 8 and the cage 5 are relatively stationary, which transforms the sliding friction into static friction that approaches zero, fundamentally blocking the extrusion deformation.

[0023] Improved accuracy: The position dead zone error during commutation is reduced from 2.0mm~5.0mm to 0.1mm~0.5mm.

[0024] Segmented retainer: Lightweight aluminum alloy or engineering plastic (such as PEEK) should be used. The retainer ensures the radial distance of the restraining torsion rope is controlled. The edges of the holes need to be rounded to reduce wear. A spring seat is located at the center of the cage to limit the radial movement of the spring.

[0025] The outer wall of the drive connecting frame 1 is fitted with a first outer cover connector 2, and a first slot 11 is formed between the first outer cover connector 2 and the drive connecting frame 1; the outer wall of the free end connector 4 is fitted with a second outer cover connector 13, and a second slot 12 is formed between the free end connector 4 and the second outer cover connector 13; the two ends of the anti-torsion outer cover 3 are respectively inserted into the first slot 11 and the second slot 12.

[0026] The anti-torsion outer cover 3 is made of rigid material at both ends and nylon braided mesh in the middle. The nylon braided mesh is made of high-strength nylon braided mesh. The original flattened width is 6mm. After being fitted onto a smooth cylinder with a diameter of 16mm, it is shaped by blowing with a 150° hot air gun. This changes the fiber texture of the nylon braid from a near-axial arrangement to a near-transverse arrangement. This reduces the rate of change of the cross-sectional perimeter of the braided mesh during longitudinal shrinkage and enhances its torsional resistance.

[0027] Furthermore, when shortened (muscle contraction), the anti-torsion cover 3 undergoes longitudinal compression. Because the transversely arranged fibers resemble "miniature compression springs," the anti-torsion cover 3 can prevent a section of the free end connector 4 from rotating with the torsion rope 8; when it is necessary to stop the tension (muscle relaxation), the power is cut off or reversed, and the elastic reset member 6 provides an outward relaxation restoring force to the internal "rope + retainer" structure, overcoming the physical limitation of traditional flexible tendons that "can only be pulled but not pushed."

[0028] Ultra-high molecular weight polyethylene (UHMWPE) utilizes its high tensile strength, combined with a cage, to achieve high-precision power transmission.

[0029] A first ridge joint 9 is fixedly connected to the output end of the drive motor 10, and one end of the twisted rope 8 is fixedly connected to the first ridge joint 9; a second ridge joint 7 is provided on the free end joint 4, and the second ridge joint 7 is fixedly connected to the other end of the twisted rope 8.

[0030] This layout directly measures the relative rotation angle between two adjacent cages. Due to the geometric constraints of the mechanism, the torsional angle between each cage segment is theoretically uniformly distributed.

[0031] By measuring local relative angles The state of the entire drive system can be deduced: Let the total number of segments of the mechanism be Then the total rotation angle of the motor drive end relative angles to actual measurements The relationship is: .

[0032] The derived total angle By substituting the geometric dynamics model of this invention, the current muscle output length can be calculated in real time. :

[0033] in, To maintain the radial spacing of the ropes within the frame, This is the initial segment length.

[0034] Because the TSA mechanism physically has a mechanical limit from "maximum expansion" to "maximum contraction", and in the typical application scenario of this invention, the single relative rotation angle of adjacent cages... Restricted to Within (within a single lap).

[0035] Even though the entire drive process involves multiple rotations of the motor, by monitoring the local relative angle After a power outage and restart, the system can function without complex zero-finding operations, and can proceed through the current... The value directly maps to a unique, absolute muscle length value. This eliminates the reliance on expensive, bulky multi-turn encoders, enabling miniaturization and high reliability of the structure.

[0036] The retainer 5 is evenly provided with threading holes for the twisted rope 8 to pass through. The threading holes are symmetrically distributed along the circumference of the retainer 5, and the edges of the threading holes are rounded.

[0037] The elastic reset element 6 uses a compression spring.

[0038] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "one side," "outer," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include at least one of those features.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-precision twisted rope drive mechanism based on a segmented retainer, comprising a drive connecting frame (1) and a free end connector (4), wherein a drive motor (10) is fixedly connected to the inner side of the drive connecting frame (1), characterized in that: Elastic reset members (6) are arranged in an array between the drive motor (10) and the free end connector (4). A retainer (5) is provided between every two elastic reset members (6). Multiple twisted ropes (8) are also provided between the drive motor (10) and the free end connector (4). Each twisted rope (8) passes through the retainer (5) in sequence. The multiple twisted ropes (8) are radially isolated from each other by the retainer (5) and twist and contract synchronously. The outer walls of the retainer (5) and the elastic reset members (6) are covered with anti-torsion covers (3). The two ends of the anti-torsion covers (3) are fixed to the drive connection frame (1) and the free end connector (4) respectively.

2. The high-precision torsion rope drive mechanism based on a segmented retainer according to claim 1, characterized in that: The outer wall of the drive connecting frame (1) is fitted with a first outer cover connector (2), and a first slot (11) is formed between the first outer cover connector (2) and the drive connecting frame (1); the outer wall of the free end connector (4) is fitted with a second outer cover connector (13), and a second slot (12) is formed between the free end connector (4) and the second outer cover connector (13); the two ends of the anti-torsion cover (3) are respectively inserted into the first slot (11) and the second slot (12).

3. The high-precision torsion rope drive mechanism based on a segmented retainer according to claim 1, characterized in that: The anti-torsion cover (3) is made of rigid material at both ends and nylon braided mesh in the middle.

4. The high-precision torsion rope drive mechanism based on a segmented retainer according to claim 1, characterized in that: A first ridge joint (9) is fixedly connected to the output end of the drive motor (10), and one end of the twisted rope (8) is fixedly connected to the first ridge joint (9); a second ridge joint (7) is provided on the free end joint (4), and the second ridge joint (7) is fixedly connected to the other end of the twisted rope (8).

5. A high-precision torsion rope drive mechanism based on a segmented retainer according to claim 1, characterized in that: The retainer (5) is evenly provided with threading holes for the twisted rope (8) to pass through. The threading holes are symmetrically distributed along the circumference of the retainer (5), and the edges of the threading holes are rounded.

6. A high-precision torsion rope drive mechanism based on a segmented retainer according to claim 1, characterized in that: The elastic reset element (6) uses a compression spring.

7. A high-precision torsion rope drive mechanism based on a segmented retainer according to claim 4, characterized in that: An encoder is provided on the second ridge joint (7), and a radial magnet is provided on the cage (5) adjacent to the second ridge joint (7).

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