Six-degree-of-freedom parallel robot driven by lead screw nut pair

Abstract

The utility model discloses a six-degree-of-freedom parallel robot driven by a lead screw nut pair, and relates to the technical field of mechanisms and robots. The six-degree-of-freedom parallel robot is characterized by comprising a machine frame, a movable platform and six movement branch chains connected between the machine frame and the movable platform in parallel; each motion branch chain comprises a motor, a guide rail, a lead screw, a nut, a sliding block, a connecting rod and a connecting plate; the motor is fixedly installed on the connecting plate, an output shaft of the motor is connected with the lead screw, the pair of guide rails are arranged on the two sides of the lead screw in parallel respectively, the nut is in threaded connection with the lead screw and is in sliding fit with the two guide rails, and the top end of the connecting rod is fixedly connected to the nut. The motor drives the lead screw and drives the connecting rod to move through the nut so as to change the posture of the movable platform. The movable platform of the parallel robot should have a large rotation range, can adapt to different machining paths and posture requirements, and is more compact in structure and good in structural rigidity.

Description

Technical Field

[0001] This utility model relates to the fields of mechanics and robotics, specifically a 6-DOF parallel robot driven by a lead screw and nut pair. Background Technology

[0002] Traditional robots have the following shortcomings in machining operations such as drilling and milling:

[0003] 1) In some complex processing tasks, robots need to be able to achieve multi-degree-of-freedom motion to adapt to different processing paths and posture requirements. Traditional robots are difficult to achieve complex motion trajectories due to structural limitations.

[0004] 2) In high-load or high-processing-force applications, the robot needs to have sufficient rigidity; otherwise, structural deformation may lead to a decrease in processing accuracy or equipment damage.

[0005] 3) In some limited spaces, traditional robots may be difficult to install or operate due to their large size, which limits their application scope.

[0006] Therefore, in high-precision machining tasks (such as drilling and milling), traditional robots cannot guarantee machining accuracy due to insufficient transmission accuracy or poor structural rigidity, resulting in unstable machining quality. Utility Model Content

[0007] The purpose of this invention is to address the shortcomings of the existing technology by providing a 6-DOF parallel robot driven by a lead screw and nut pair. The moving platform of this parallel robot should have a large rotation range, be able to adapt to different processing paths and posture requirements, have a more compact structure, and have good structural rigidity.

[0008] The technical solution of this utility model is as follows:

[0009] A 6-DOF parallel robot driven by a lead screw and nut pair is characterized by comprising: a frame, a moving platform, and six motion chains connected in parallel between the frame and the moving platform; each motion chain includes a motor, guide rails, a lead screw, a nut, a slider, a connecting rod, and a connecting plate; the motor is fixedly mounted on the connecting plate, the output shaft of the motor is connected to the lead screw, a pair of guide rails are arranged parallel to each other on both sides of the lead screw, the nut is threaded to the lead screw and slides with the two guide rails, the slider is fixedly connected to the nut, and the two ends of the connecting rod are respectively connected to the slider and the moving platform; the motor drives the lead screw, which in turn drives the connecting rod to move through the nut, thereby changing the posture of the moving platform.

[0010] In the above scheme, the 6-DOF parallel robot achieves complex motion trajectories and attitude adjustments of the moving platform in space through the coordinated control of six kinematic chains. Furthermore, the parallel structure of the six kinematic chains provides higher rigidity, enabling it to withstand greater loads and higher processing forces, thus maintaining robot stability during high-load processing tasks and improving processing efficiency and equipment reliability. In addition, the six kinematic chains are connected in parallel between the frame and the moving platform, resulting in a compact design that occupies little space, facilitating installation and use in limited spaces.

[0011] In the above scheme, the lead screw and nut pair, consisting of a motor, lead screw, guide rail, and nut, has high transmission accuracy and can achieve precise displacement control. The motor precisely drives the lead screw, causing the nut to move axially along the guide rail. The nut then drives the connecting rods to move via a slider. The six connecting rods are connected to the moving platform, thereby precisely controlling the position and attitude of the moving platform and ensuring machining accuracy.

[0012] Furthermore, the frame includes a base, six uprights, and a top cover, with the uprights installed between the top cover and the base. This frame structure design not only provides a stable mounting foundation for the motion chains but also enhances the overall rigidity and stability of the frame through the rationally distributed uprights. This allows it to better withstand various forces and torques generated by the robot during movement, improving the robot's reliability under complex motion conditions.

[0013] Furthermore, both the top cover and the base are composed of three long rods and three short rods connected end to end, with the long and short rods spaced apart. The top cover and the base have essentially the same structure, ensuring the overall stability of the frame. The unique rod layout not only ensures the structural strength of the top cover and the base but also optimizes the mass distribution to a certain extent, making the robot more stable during movement.

[0014] Furthermore, the top of the motion chain is connected to the upper cover via a Hooke's joint, and the bottom of the motion chain is connected to the moving platform via a ball joint. The use of the Hooke's joint and the ball joint further improves the flexibility and precision of the robot's movement, enabling the robot to adapt to various complex processing requirements.

[0015] Furthermore, the upper cover is evenly distributed with three sets of upper bearing supports, each set containing two upper bearing supports installed at 100° intervals. The moving chain is connected to the corresponding upper bearing support via Hooke's joints. This unique layout not only evenly distributes the forces generated by the moving chain during movement, reducing local stress concentration, but also improves the stability of the moving chain.

[0016] Furthermore, the moving platform is evenly distributed with three sets of lower bearing supports, each set containing two parallel lower bearing supports. The connecting rod is connected to the corresponding lower bearing support via ball joints. This layout better adapts to the motion requirements of the moving platform and ensures a stable connection between the connecting rod and the moving platform. The parallel-installed lower bearing supports improve the reliability of the motion chain.

[0017] Furthermore, a drill bit or milling cutter is mounted on the moving platform, and a worktable is provided below the moving platform. A fixture for holding the workpiece is provided on the worktable. During machining, the workpiece to be machined is held by the fixture on the worktable. The drive motor of the drill bit or milling cutter on the moving platform is turned on. By controlling the working state of the six motion chains, the posture of the drill bit or milling cutter on the moving platform is changed to machine the workpiece, thus improving production efficiency and machining accuracy.

[0018] This utility model has a compact structure, ingenious layout, and high transmission precision. Its moving platform can achieve three-dimensional translation and rotation, and its moving platform can achieve a wide range of rotation. It can be used in drilling, milling, assembly, 3D printing and other fields. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 For Figure 1 Top view;

[0021] Figure 3 This is a schematic diagram showing the connection between a certain motion branch and the moving platform in this utility model;

[0022] Figure 4 This is a schematic diagram of the kinematic branch structure in this utility model;

[0023] Figure 5 This is a schematic diagram of the rotation of the 6-DOF parallel robot of this utility model;

[0024] Figure 6 This is a schematic diagram of the processing state of the 6-DOF parallel robot of this utility model;

[0025] In the diagram: 1. Column; 2. Top cover; 3. Base; 4. Hooke's hinge; 5. Motor; 6. Guide rail; 7. Lead screw; 8. Slider; 9. Connecting rod; 10. Ball joint; 11. Moving platform; 12. Upper bearing support; 13. Upper bearing support; 14. Upper bearing support; 15. Upper bearing support; 16. Upper bearing support; 17. Lower bearing support; 18. Lower bearing support; 19. Lower bearing support; 20. Lower bearing support; 21. Lower bearing support; 22. Lower bearing support; 23. Nut; 24. Connecting plate; 25. Drive motor; 26. Milling cutter; 27. Workpiece; 28. Fixture; 29. ​​Worktable; 30. Long rod; 31. Short rod; 32. Detailed Implementation

[0026] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0027] like Figure 1 As shown, a 6-DOF parallel robot driven by a lead screw and nut pair includes a frame, a moving platform 11, and 6 identical kinematic chains connected in parallel between the frame and the moving platform 11.

[0028] The frame includes a top cover 2, six uprights 1, and a base 3, with the uprights installed between the top cover and the base. For example... Figure 2 As shown, the structures of the top cover and the base are basically the same, both consisting of three long rods 31 and three short rods 32 connected end to end, with the long and short rods spaced apart. The top cover 2 has three sets of upper bearing supports (upper bearing supports 17 and 12, upper bearing supports 13 and 14, and upper bearing supports 15 and 16), each set containing two upper bearing supports installed at 100° intervals, such as upper bearing supports 15 and 16 installed at 100° intervals. The top of the motion chain is connected to the upper bearing supports of the top cover via a Hooke hinge 4.

[0029] Each kinematic branch, such as Figure 3 , Figure 4 As shown, the system includes a motor 5, guide rails 6, a lead screw 7, a nut 24, a slider 8, a connecting rod 9, and a connecting plate 24. The motor is fixedly mounted on the connecting plate (the motor, guide rails, and lead screw are all mounted on the connecting plate). The motor's output shaft is connected to the lead screw. A pair of guide rails are arranged parallel to each other on both sides of the lead screw. The nut is threaded to the lead screw and slides with the two guide rails. The slider is fixedly connected to the nut. The two ends of the connecting rod are connected to the slider and the moving platform, respectively. The motor precisely drives the lead screw, causing the nut to move axially along the guide rails. Then, the nut moves the connecting rod through the slider. The six connecting rods are connected to the moving platform, thereby precisely controlling the position and attitude of the moving platform (e.g., ...). Figure 5 (as shown in the figure), thus ensuring machining accuracy.

[0030] like Figure 2 , Figure 3 As shown, the moving platform 11 has three sets of lower bearing supports evenly distributed (lower bearing supports 19 and 20, lower bearing supports 21 and 22, and lower bearing supports 23 and 18). Each set of lower bearing supports includes two lower bearing supports installed in parallel, such as lower bearing supports 23 and 18 installed in parallel. The bottom of the motion chain (connecting rod) is connected to the lower bearing supports of the moving platform through ball joints 10.

[0031] In one embodiment of this utility model, such as Figure 6As shown, a milling cutter 27 is mounted on the moving platform 11, and a worktable 30 is located below the moving platform. A fixture 29 for holding the workpiece 28 is mounted on the worktable. During machining, the workpiece to be machined is held by the fixture on the worktable. The drive motor 26 of the drill or milling cutter on the moving platform is turned on. By controlling the working state of the six motion chains, the posture of the drill or milling cutter on the moving platform is changed to machine the workpiece. In this embodiment, the drive pair is the lead screw and nut pair in each motion chain, and the drive method is motor drive. This parallel robot has six degrees of freedom, enabling the moving platform to rotate and translate in any direction, thus improving machining accuracy.

Claims

1. A 6-DOF parallel robot driven by a lead screw and nut pair, characterized in that, include: The system comprises a frame, a moving platform, and six motion chains connected in parallel between the frame and the moving platform. Each motion chain includes a motor, guide rails, a lead screw, a nut, a slider, a connecting rod, and a connecting plate. The motor is fixedly mounted on the connecting plate, and its output shaft is connected to the lead screw. A pair of guide rails are arranged parallel to each other on both sides of the lead screw. The nut is threaded to the lead screw and slides with the two guide rails. The slider is fixedly connected to the nut, and the two ends of the connecting rod are connected to the slider and the moving platform, respectively. The motor drives the lead screw, which in turn moves the connecting rod through the nut to change the posture of the moving platform.

2. A 6-DOF parallel robot driven by a lead screw and nut pair according to claim 1, characterized in that, The frame includes a base, six columns, and a top cover, with the columns installed between the top cover and the base.

3. A 6-DOF parallel robot driven by a lead screw and nut pair according to claim 2, characterized in that, Both the top cover and the base are composed of three long rods and three short rods connected end to end, with the long rods and short rods spaced apart.

4. A 6-DOF parallel robot driven by a lead screw and nut pair according to claim 3, characterized in that, The top of the motion chain is connected to the top cover via a Hooke hinge, and the bottom of the motion chain is connected to the moving platform via a ball joint.

5. A 6-DOF parallel robot driven by a lead screw and nut pair according to claim 4, characterized in that, The top cover is evenly distributed with three sets of upper bearing supports. Each set of upper bearing supports includes two upper bearing supports installed at 100° intervals. The motion chain is respectively connected to the corresponding upper bearing support via Hooke's joints.

6. A 6-DOF parallel robot driven by a lead screw and nut pair according to claim 5, characterized in that, The moving platform is evenly distributed with three sets of lower bearing supports. Each set of lower bearing supports includes two lower bearing supports installed in parallel. The connecting rod is installed and connected to the corresponding lower bearing support through ball joints.

7. A 6-DOF parallel robot driven by a lead screw and nut pair according to claim 1 or 6, characterized in that, The moving platform is equipped with a drill bit or a milling cutter, and a worktable is provided below the moving platform. The worktable is equipped with a clamp for holding the workpiece.

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