A six-DOF parallel mechanism for a dual-motion platform containing symmetrical composite drive branches

Abstract

A six-DOF parallel mechanism for a dual-moving platform containing symmetrical composite drive branches. It includes a frame, a second moving platform, connectors, bearings, a first moving platform, first branch I, second branch II, third branch III, and fourth branch IV. The advantages of this invention compared to existing technologies are: firstly, two branches are symmetrical composite drive branches, and the four branches enable the moving platform to achieve six degrees of freedom of motion, reducing interference between branches and increasing the workspace; secondly, the use of linear modules as moving components and electric cylinders as telescopic components increases motion stability and improves load capacity; finally, the overall mechanism is planar symmetrical, with two symmetrical planes and two pairs of identical branches, reducing manufacturing costs.

Description

Technical Field

[0001] This invention belongs to the field of parallel mechanism technology, specifically relating to a six-degree-of-freedom parallel mechanism for a dual-motion platform containing a symmetrical composite drive branch. Background Technology

[0002] Parallel mechanisms are widely used in many fields such as machining and medical treatment because they have advantages such as high motion accuracy, strong load-bearing capacity and high rigidity.

[0003] When a parallel mechanism has six degrees of freedom, it typically requires six active drive branches. An excessive number of drive branches with different structures increases manufacturing costs. To reduce the number of drive branches, a composite drive method is used. The drive branches in a parallel mechanism have identical and symmetrically distributed structures, which reduces manufacturing costs. Therefore, developing a six-degree-of-freedom parallel mechanism for a dual-motion platform containing symmetrical composite drive branches has significant research and application value. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a six-degree-of-freedom parallel mechanism for a dual-motion platform containing a symmetrical composite drive branch.

[0005] To achieve the above objectives, the present invention provides a six-degree-of-freedom parallel mechanism for a dual-moving platform containing symmetrical composite drive branches, comprising a frame, a second moving platform, a connector, bearings, a first moving platform, a first branch I, a second branch II, a third branch III, and a fourth branch IV.

[0006] The frame includes a first branch base, a second branch base, a third branch base, a fourth branch base, and a base plate; the base plate is horizontally arranged; the first branch base and the third branch base are horizontally fixed to the middle of the two sides of the top surface of the base plate in the front-back direction; the second branch base and the fourth branch base are vertically fixed to the middle of the front and back of the top surface of the base plate in a face-to-face manner.

[0007] The first moving platform is symmetrically provided with a first cross hinge support and a second cross hinge support on both sides, and a bearing is installed in the middle; the second moving platform is symmetrically provided with a first ball hinge support and a second ball hinge support on both sides of the bottom surface, and a first hinge support is provided in the middle of the bottom surface; the upper end of the connecting piece is hinged to the first hinge support to form a first rotating pair, and the lower end of the connecting piece is inserted and fixed in the center hole of the bearing to form a second rotating pair.

[0008] The first branch I and the third branch III have the same structure and are symmetrically distributed, each including a first linear module and a first telescopic assembly. The first linear module includes a first slider, a second hinged support, a first lead screw, a first slide rail, and a first motor. The first slide rail is fixed to the top surface of the first branch base or the third branch base of the frame. The first lead screw is arranged parallel to the first slide rail. The first motor is located outside one end of the first slide rail, and its output end is connected to one end of the first lead screw. The first lead screw is connected to the first slider via a lead screw nut. The first slider is also slidably connected to the first slide rail, and a second hinged support is provided on the top surface of the first slider. The first telescopic assembly includes a first electric cylinder, a second motor, and a ball joint. The upper end of the first electric cylinder is connected to the first or second ball joint support on the second moving platform via a ball joint, and the lower end is hinged to the second hinged support to form a third revolute joint. The output end of the second motor is connected to the electric push rod on the first electric cylinder.

[0009] The second branch II and the fourth branch IV have the same structure and are symmetrically distributed, both including a second linear module and a fixed-length rod; the second linear module includes a second lead screw, a second slider, a third hinge support, a second slide rail, and a third motor; the second slide rail is vertically fixed on the inner side of the second branch base or the fourth branch base of the frame; the second lead screw is arranged parallel to the second slide rail; the third motor is located on the outer side of one end of the second slide rail and its output end is connected to one end of the second lead screw; the second lead screw is connected to the second slider through a lead screw nut, and the second slider is simultaneously connected to the second slide rail in a sliding manner, and a third hinge support is provided on the outer side of the second slider; the upper and lower ends of the fixed-length rod are respectively provided with a fourth hinge support and a fifth hinge support; the fourth hinge support and the third hinge support are connected through a first cross hinge; the fifth hinge support is connected to the first cross hinge support or the second cross hinge support on the first moving platform through a second cross hinge.

[0010] The first branch base and the third branch base are symmetrically arranged, and the second branch base and the fourth branch base are symmetrically arranged.

[0011] The first branch base, the second branch base, the third branch base, the fourth branch base, and the base plate are all rectangular plates.

[0012] Compared with the prior art, the advantages of the present invention are:

[0013] 1. There are two symmetrical composite drive branches, and the four branches enable the moving platform to achieve six degrees of freedom of motion, thereby reducing interference between branches and increasing the workspace range.

[0014] 2. The use of linear modules as moving components and electric cylinders as telescopic components increases motion stability and improves load capacity.

[0015] 3. The overall structure is symmetrical with two symmetrical planes, which can reduce manufacturing costs. Attached Figure Description

[0016] Figure 1 A schematic diagram of the overall structure of the six-degree-of-freedom parallel mechanism of the dual-motion platform containing a symmetrical composite drive branch provided by the present invention;

[0017] Figure 2 A schematic diagram of the frame in the six-degree-of-freedom parallel mechanism of a dual-motion platform containing a symmetrical composite drive branch provided by the present invention;

[0018] Figure 3 A schematic diagram of the moving platform in a six-degree-of-freedom parallel mechanism of a dual-moving platform containing a symmetrical composite driving branch provided by the present invention;

[0019] Figure 4 A schematic diagram of the first linear module in the six-degree-of-freedom parallel mechanism of a dual-motion platform containing a symmetrical composite drive branch provided by the present invention;

[0020] Figure 5 A schematic diagram of the first branch in the six-degree-of-freedom parallel mechanism of a dual-motion platform containing a symmetrical composite driving branch provided by the present invention;

[0021] Figure 6 A schematic diagram of the second linear module in the six-degree-of-freedom parallel mechanism of a dual-motion platform containing a symmetrical composite drive branch provided by the present invention;

[0022] Figure 7 A schematic diagram of the second branch in the six-degree-of-freedom parallel mechanism of a dual-motion platform containing a symmetrical composite driving branch provided by the present invention. Detailed Implementation

[0023] 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.

[0024] like Figure 1 — Figure 7 As shown, the six-degree-of-freedom parallel mechanism of a dual-moving platform with symmetrical composite drive branches provided by the present invention includes a frame 1, a second moving platform 2, a connector 4, a bearing 5, a first moving platform 6, a first branch I, a second branch II, a third branch III, and a fourth branch IV.

[0025] The frame 1 includes a first branch base 101, a second branch base 102, a third branch base 103, a fourth branch base 104, and a base plate 105; wherein the base plate 105 is horizontally arranged; the first branch base 101 and the third branch base 103 are horizontally fixed to the middle of both sides of the top surface of the base plate 105 in the front-rear direction; the second branch base 102 and the fourth branch base 104 are vertically fixed to the middle of the front and rear sides of the top surface of the base plate 105 in a face-to-face manner;

[0026] The first moving platform 6 is symmetrically provided with a first cross hinge support 601 and a second cross hinge support 602 on both sides, and a bearing 5 is installed in the middle; the bottom surface of the second moving platform 2 is symmetrically provided with a first ball hinge support 201 and a second ball hinge support 203 on both sides, and a first hinge support 202 is provided in the middle of the bottom surface; the upper end of the connecting piece 4 is hinged to the first hinge support 202 to form a first rotating pair 3, and the lower end of the connecting piece 4 is inserted and fixed in the center hole of the bearing 5 to form a second rotating pair 18.

[0027] The first branch I and the third branch III have the same structure and are symmetrically distributed, each including a first linear module 7 and a first telescopic component 8; wherein the first linear module 7 includes a first slider 701, a second hinge support 702, a first lead screw 703, a first slide rail 704, and a first motor 13; the first slide rail 704 is fixed on the top surface of the first branch base 101 or the third branch base 103 of the frame 1; the first lead screw 703 is arranged parallel to the first slide rail 704; the first motor 13 is located outside one end of the first slide rail 704 and its output end is connected to one end of the first lead screw 703; the first lead screw 701... 03 is connected to the first slider 701 via a lead screw nut. The first slider 701 is also slidably connected to the first slide rail 704. A second hinge support 702 is provided on the top surface of the first slider 701. The first telescopic assembly 8 includes a first electric cylinder 801, a second motor 9, and a ball joint 10. The upper end of the first electric cylinder 801 is connected to the first ball joint support 201 or the second ball joint support 203 on the second moving platform 2 via the ball joint 10. The lower end is hinged to the second hinge support 702 to form a third revolute pair 15. The output end of the second motor 9 is connected to the electric push rod on the first electric cylinder 801.

[0028] The second branch II and the fourth branch IV have the same structure and are symmetrically distributed, both including a second linear module 14 and a fixed-length rod 12; wherein the second linear module 14 includes a second lead screw 1401, a second slider 1402, a third hinge support 1403, a second slide rail 1404 and a third motor 17; the second slide rail 1404 is vertically fixed on the inner side of the second branch base 102 or the fourth branch base 104 of the frame 1; the second lead screw 1401 is arranged parallel to the second slide rail 1404; the third motor 17 is located outside one end of the second slide rail 1404 and its output end is connected to one end of the second lead screw 1401. The second lead screw 1401 is connected to the second slider 1402 via a lead screw nut. The second slider 1402 is also connected to the second slide rail 1404 in a sliding manner. A third hinge support 1403 is provided on the outer side of the second slider 1402. A fourth hinge support 1201 and a fifth hinge support 1202 are respectively provided at the upper and lower ends of the fixed length rod 12. The fourth hinge support 1201 and the third hinge support 1403 are connected via a first cross hinge 16. The fifth hinge support 1202 is connected to the first cross hinge support 601 or the second cross hinge support 602 on the first moving platform 6 via a second cross hinge 11.

[0029] The first branch base 101 and the third branch base 103 are symmetrically arranged, and the second branch base 102 and the fourth branch base 104 are symmetrically arranged.

[0030] The first branch base 101, the second branch base 102, the third branch base 103, the fourth branch base 104 and the base plate 105 are all rectangular plates.

[0031] The working principle of the six-degree-of-freedom parallel mechanism of the dual-moving platform with symmetrical composite drive branches provided by the present invention is described as follows: Taking the axis of the first lead screw 703 as the x-axis, the z-axis perpendicular to the top surface of the frame 1 and upwards, and the y-axis conforming to the right-hand rule, the six-degree-of-freedom parallel mechanism with composite linear modules provided by the present invention selects two first sliders 701, two second sliders 1402, and two first electric cylinders 801 as active pairs, which can realize the control of the second moving platform 2 with three rotations and three translations, totaling six degrees of freedom. Fixing the two first sliders 701 and two second sliders 1402 and causing the two first electric cylinders 801 to extend and retract in opposite directions can realize the degree of freedom of rotation of the second moving platform 2 around the x-axis. Fixing the two first sliders 701 and two first electric cylinders 801 and causing the two second sliders 1402 to move in opposite directions can realize the degree of freedom of rotation of the second moving platform 2 around the y-axis. Degrees of freedom: Fixing two second sliders 1402 and two first electric cylinders 801, and moving the two first sliders 701 in opposite directions, allows the second moving platform 2 to rotate around the z-axis. Fixing two first sliders 701, and moving the two second sliders 1402 and two first electric cylinders 801 in the same direction and at equal distances, allows the second moving platform 2 to move along the z-axis. Fixing two first electric cylinders 801, and moving the two first sliders 701 in the same direction and at equal distances, with the two second sliders 1402 moving in coordination, allows the second moving platform 2 to move along the x-axis. Fixing two first sliders 701, and moving the two first electric cylinders 801 in opposite directions, with the two second sliders 1402 moving in coordination, allows the second moving platform 2 to move along the y-axis. Ultimately, the second moving platform 2 has six degrees of freedom: three rotational and three translational.

[0032] 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 dual-motive platform six-degree-of-freedom parallel mechanism with symmetric compound driven branched chains, characterized in that: The double-movable platform six-degree-of-freedom parallel mechanism comprising symmetric composite driving branch chains comprises a rack (1), a second movable platform (2), a connecting piece (4), a bearing (5), a first movable platform (6), a first branch chain I, a second branch chain II, a third branch chain III and a fourth branch chain IV; The rack (1) comprises a first branch chain base (101), a second branch chain base (102), a third branch chain base (103), a fourth branch chain base (104) and a bottom plate (105); the bottom plate (105) is horizontally arranged; the first branch chain base (101) and the third branch chain base (103) are horizontally fixed at the middle portions of the top surface of the bottom plate (105) on both sides in the front-rear direction; the second branch chain base (102) and the fourth branch chain base (104) are vertically fixed at the front-rear middle portions of the top surface of the bottom plate (105) in a face-to-face manner; The first movable platform (6) is symmetrically provided with a first cross-hinged support (601) and a second cross-hinged support (602) on both sides, and is provided with the bearing (5) at the middle portion; the bottom surface of the second movable platform (2) is symmetrically provided with a first spherical hinge support (201) and a second spherical hinge support (203) on both sides, and is provided with a first hinged support (202) at the middle portion; the upper end of the connecting piece (4) is hinged to the first hinged support (202) to form a first rotary pair (3), and the lower end of the connecting piece (4) is inserted and fixed in the central hole of the bearing (5) to form a second rotary pair (18); The first branch chain I and the third branch chain III are the same in structure and symmetrically distributed, and each comprises a first linear module (7) and a first telescopic assembly (8); the first linear module (7) comprises a first slider (701), a second hinged support (702), a first lead screw (703), a first sliding rail (704) and a first motor (13); the first sliding rail (704) is fixed on the top surface of the first branch chain base (101) or the third branch chain base (103) of the rack (1); the first lead screw (703) is arranged in parallel with the first sliding rail (704); the first motor (13) is arranged outside one end of the first sliding rail (704) and the output end thereof is connected with one end of the first lead screw (703); the first lead screw (703) is connected with the first slider (701) through a lead screw nut, the first slider (701) is connected with the first sliding rail (704) in a sliding manner, and the second hinged support (702) is arranged on the top surface of the first slider (701); the first telescopic assembly (8) comprises a first electric cylinder (801), a second motor (9) and a spherical hinge (10); the upper end of the first electric cylinder (801) is connected with the first spherical hinge support (201) or the second spherical hinge support (203) on the second movable platform (2) through the spherical hinge (10), and the lower end thereof is hinged to the second hinged support (702) to form a third rotary pair (15); the output end of the second motor (9) is connected with an electric push rod on the first electric cylinder (801); The second branch chain II and the fourth branch chain IV are identical in structure and symmetrically distributed, and both include a second linear module (14) and a fixed-length rod (12); the second linear module (14) includes a second lead screw (1401), a second sliding block (1402), a third hinged support (1403), a second sliding rail (1404) and a third motor (17); the second sliding rail (1404) is vertically fixed on the inner side surface of the second branch chain base (102) or the fourth branch chain base (104) of the rack (1); the second lead screw (1401) is arranged in parallel with the second sliding rail (1404); the third motor (17) is arranged on the outer side of one end of the second sliding rail (1404) and the output end thereof is connected with one end of the second lead screw (1401); the second lead screw (1401) is connected with the second sliding block (1402) through a lead screw nut, the second sliding block (1402) is connected with the second sliding rail (1404) in a sliding mode, and the outer side surface of the second sliding block (1402) is provided with the third hinged support (1403); the upper and lower ends of the fixed-length rod (12) are respectively provided with a fourth hinged support (1201) and a fifth hinged support (1202); the fourth hinged support (1201) is connected with the third hinged support (1403) through a first cross hinge (16); and the fifth hinged support (1202) is connected with the first cross hinged support (601) or the second cross hinged support (602) on the first moving platform (6) through a second cross hinge (11).

2. The dual-actuated platform 6-DOF parallel mechanism with symmetric compound driven branch chains according to claim 1, characterized in that: The first branch chain base (101) and the third branch chain base (103) are symmetrically arranged, and the second branch chain base (102) and the fourth branch chain base (104) are symmetrically arranged.

3. The dual-actuated platform 6-DOF parallel mechanism with symmetric compound driven branch chains according to claim 1, characterized in that: The first branch chain base (101), the second branch chain base (102), the third branch chain base (103), the fourth branch chain base (104) and the bottom plate (105) are all rectangular plates.

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