A muscle-like parallel elastic joint

Abstract

This utility model discloses a muscle-inspired parallel elastic joint, comprising a motor reduction mechanism, a parallel flexible mechanism, and a base. The motor reduction mechanism includes a brushless motor and a planetary reducer. The parallel flexible mechanism includes a heart-shaped cam, a flexible rope, a wire-pressing mechanism, and a linear spring with one end connected to the flexible rope. The heart-shaped cam is fixedly connected to the joint spindle screw. The flexible rope is wound around the heart-shaped cam, and one end of the flexible rope is connected to one end of the linear spring. The wire-pressing mechanism is used to prevent the flexible rope from contacting the forearm inside the joint, thereby reducing friction. This utility model is a parallel elastic structure with muscle-inspired characteristics, which can achieve continuous and wide-range variable stiffness of the parallel elastic joint. It can be used as an integrated drive and control module and has the adaptive stiffness characteristics similar to muscles.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical equipment technology, and in particular relates to a robotic arm system with a muscle-inspired parallel elastic joint. Background Technology

[0002] Currently, the "bionic muscles" widely researched and used both domestically and internationally primarily employ pneumatic and hydraulic technologies. While this rigid joint actuation method is technologically mature and has many developmental types, limitations in portability and practicality, coupled with the constraint of high mechanical stiffness, result in weak robustness and adaptability of rigid actuators. This leaves certain shortcomings and deficiencies for robots to achieve compliant movements, adaptive adjustments, and low-energy motion. Therefore, it is necessary to research and improve the existing problems of variable stiffness range and continuity in robot joints. Utility Model Content

[0003] To address the shortcomings of the existing technology, this invention provides a muscle-inspired parallel elastic joint with elastic properties close to those of biological muscle and strong anti-interference capabilities.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] This utility model discloses a muscle-inspired parallel elastic joint, characterized in that it includes a motor reduction mechanism, a parallel flexible mechanism, and a base. The motor reduction mechanism includes a brushless motor and a planetary reducer. The parallel flexible mechanism includes a heart-shaped cam, a flexible rope, a wire pressing mechanism, and a linear spring with one end connected to the flexible rope. The heart-shaped cam is fixedly connected to the joint spindle bolt located on the motor reduction mechanism. The flexible rope is wound around the heart-shaped cam, and one end of the flexible rope passes through the wire pressing mechanism and is connected to one end of the linear spring. The wire pressing mechanism is used to prevent the flexible rope from contacting other components in the joint forearm.

[0006] Furthermore, the brushless motor and the planetary reducer are directly connected in a collimated drive transmission mode, and the output joint spindle drives the forearm to rotate.

[0007] Furthermore, the wire pressing mechanism includes a wire pressing cover and a wire pressing cover connecting block, wherein the wire pressing cover is fixed to the wire pressing cover connecting block on the forearm by screws.

[0008] Furthermore, the brushless motor is connected to a planetary reducer, with one end using a shoulder for axial positioning and the other end capable of automatic positioning.

[0009] Furthermore, the joint spindle is also connected to the magnetic encoder of the forearm via a heart-shaped cam, and the magnetic encoder is used to monitor the rotation angle of the joint spindle in real time.

[0010] Furthermore, the heart-shaped cam is symmetrically and vertically installed inside the forearm.

[0011] Furthermore, the heart-shaped cam is fixed to the joint spindle by screws, and the heart-shaped cam remains stationary during the rotation of the forearm.

[0012] Furthermore, the plane of the heart-shaped cam is parallel to the axis of the linear spring.

[0013] The effect achieved by this invention is as follows: By connecting one end of a linear spring to the forearm and the other end to a flexible rope, which is wound around a heart-shaped cam connected to the joint's main shaft, the elastic restoring torque of the heart-shaped cam with the flexible rope and the driving torque generated by the brushless motor located on the motor reduction mechanism are output in parallel on the joint's main shaft, thus giving the joint the characteristics of a parallel structure. Simultaneously, by using the flexible rope to stretch the linear spring in conjunction with the heart-shaped cam, as the joint's main shaft drives the heart-shaped cam to rotate, the flexible rope on the heart-shaped cam stretches the linear spring, generating a nearly linearly increasing tension. The rotation of the heart-shaped cam causes the tangent point between the flexible rope and the heart-shaped cam to continuously change, thereby causing the lever arm of the linear tension torque to continuously change, generating an upwardly concave elastic restoring torque. This gives the parallel elastic structure elastic characteristics similar to those of biological muscle. In summary, this invention, by setting up a parallel elastic structure with upwardly concave elastic characteristics, allows the force generated by the parallel linear spring to continuously increase from zero during joint rotation. Furthermore, by replacing springs with different stiffnesses, the joint stiffness can be made continuously and within a wide range. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is a schematic diagram of the heart-shaped cam winding device of this utility model;

[0016] Figure 3 This is a detailed view of the transmission mechanism of this utility model.

[0017] In the diagram: 1-Linear spring, 2-Flexible rope, 3-M8 bolt, 4-Base, 5-Brushless motor, 6-M6 screw, 7-M4 screw, 8-Flange shaft, 9-Planetary reducer input shaft, 10-Planetary reducer, 11-Base housing reducer fixing plate, 12-Heart-shaped cam mounting post, 13-Forearm housing, 14-M4 screw, 15-Planetary reducer retaining ring, 16-Forearm positioning post, 17-Joint spindle, 18-Forearm cover plate, 19-Cable pressure cover connecting block, 20-Set screw, 21-Forearm decorative shell, 22-Cable pressure cover, 23-Flexible rope connecting rod, 24-Heart-shaped cam, 25-Base fixing bolt, 26-Forearm housing set screw. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be described in more detail below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. The embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0019] like Figures 1-3 As shown, a muscle-like parallel elastic joint includes a motor reduction mechanism, a parallel flexible mechanism, and a base. The motor reduction mechanism includes a brushless motor 5 and a planetary reducer 10. The parallel flexible mechanism includes a heart-shaped cam 24, a flexible rope 2, a wire pressing mechanism, and a linear spring 1. The heart-shaped cam 24 is connected to the joint spindle 17 by screws. The flexible rope 2 is wound around the heart-shaped cam 24, and one end of the flexible rope 2 passes through the wire pressing mechanism and is connected to one end of the linear spring 1. The other end of the linear spring 1 is connected to the forearm. The wire pressing mechanism is used to prevent the flexible rope 1 from contacting other components in the forearm of the joint.

[0020] The flexible rope 2 is wound around the heart-shaped cam 24 connected to the joint spindle 17, realizing the parallel output of the elastic restoring torque of the heart-shaped cam 24 with the flexible rope 2 wound around it and the driving torque generated by the brushless motor 5 on the joint spindle 17, thus giving the compliant joint the characteristics of a parallel structure. At the same time, the linear spring 1 connected to the flexible rope 2 cooperates with the heart-shaped cam 24. When the joint spindle 17 drives the heart-shaped cam 24 to rotate, the flexible rope 2 on the heart-shaped cam 24 stretches the linear spring 1 to generate a tension force that grows in an approximately linear manner. The rotation of the heart-shaped cam 24 causes the tangent point between the flexible rope 2 and the heart-shaped cam 24 to change continuously, which in turn causes the lever arm of the linear tension torque to change continuously, generating an upward concave elastic restoring torque, so that this parallel elastic joint has elastic characteristics similar to biological muscles.

[0021] The brushless motor 5 on the motor reduction mechanism is directly connected to the planetary reducer 10, and the joint spindle 17 drives the forearm to rotate.

[0022] The wire pressing mechanism includes a wire pressing cover 22 and a wire pressing cover connecting block 19. The wire pressing cover 22 is installed on the wire pressing cover connecting block 19 of the wire pressing mechanism by a set screw 20. The wire pressing cover connecting block 19 is directly fixedly connected to the inside of the forearm. When the flexible rope 2 starts to stretch the linear spring 1 or retracts, it ensures that the flexible rope 2 is in the direction we guide, so that the elastic restoring torque of the heart-shaped cam 24 with the flexible rope 2 is output in parallel with the driving torque generated by the brushless motor 5 on the joint spindle 17, so that the compliant joint has the characteristics of a parallel structure, thereby ensuring that it does not come into contact with other parts.

[0023] The brushless motor 5 is directly connected to the planetary reducer 10, which is directly connected to the joint shaft 17, enabling automatic positioning.

[0024] The joint spindle 17 is connected to a magnetic encoder via a heart-shaped cam 24. The magnetic encoder is used to monitor the rotation angle of the joint spindle 17 in real time.

[0025] The heart-shaped cam 24 is symmetrically and vertically installed inside the forearm.

[0026] The heart-shaped cam 24 is fixed to the joint spindle 17 by screws.

[0027] The plane of the heart-shaped cam 24 is parallel to the axis of the linear spring 1.

[0028] This invention provides a muscle-inspired parallel elastic joint. By setting a parallel elastic structure with upward concave elastic properties, energy conversion is achieved during joint rotation, namely, the mutual conversion of electrical energy and elastic potential energy. When the joint is subjected to an external torque opposite to the direction of rotation, the motor torque interacts with the external force; when subjected to an external torque in the same direction as the rotation, the spring force interacts with the external force, thereby achieving the effect of counteracting external force interference. This solves the problem of balancing energy consumption and anti-interference performance in existing compliant joints. The force generated by the parallel linear springs can continuously increase from zero, and by replacing springs with different stiffnesses, the joint stiffness can be continuously varied over a wide range.

[0029] It should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An artificial muscle parallel elastic joint, characterized by, It includes a motor reduction mechanism, a parallel flexible mechanism, and a base. The motor reduction mechanism includes a brushless motor and a planetary reducer. The parallel flexible mechanism includes a heart-shaped cam, a flexible rope, a wire pressing mechanism, and a linear spring with one end connected to the flexible rope. The heart-shaped cam is fixedly connected to the joint spindle bolt. The flexible rope is wound around the heart-shaped cam, and one end of the flexible rope passes through the wire pressing mechanism and is connected to one end of the linear spring. The wire pressing mechanism is used to prevent the flexible rope from contacting other components inside the joint forearm.

2. The mimetic muscle parallel elastic joint of claim 1, wherein, The brushless motor and planetary reducer are directly connected, using a collimated drive transmission method, and the output joint spindle drives the forearm to rotate.

3. The muscle-like parallel elastic joint according to claim 1, characterized in that, The wire pressing mechanism includes a wire pressing cover and a wire pressing cover connecting block. The wire pressing cover is fixed to the wire pressing cover connecting block on the forearm by screws.

4. The muscle-like parallel elastic joint according to claim 2, characterized in that, The brushless motor is connected to a planetary reducer, with one end using a shoulder for axial positioning and the other end capable of automatic positioning.

5. A muscle-like parallel elastic joint according to claim 1, characterized in that, The joint spindle is connected to the magnetic encoder of the forearm via a heart-shaped cam. The magnetic encoder is used to monitor the rotation angle of the joint spindle in real time.

6. The muscle-like parallel elastic joint according to claim 1, characterized in that, The heart-shaped cam is symmetrically and vertically installed inside the forearm.

7. The muscle-like parallel elastic joint according to claim 1, characterized in that, The heart-shaped cam is fixed to the main shaft of the joint by screws, and the heart-shaped cam remains stationary during the rotation of the forearm.

8. The muscle-like parallel elastic joint according to claim 1, characterized in that, The plane of the heart-shaped cam is parallel to the axis of the linear spring.

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