A three-degree-of-freedom parallel mechanism with two-movement and one-screw motion mode

Abstract

The present invention discloses a three-degree-of-freedom parallel mechanism with two-movement-one-spiral motion modes, belonging to the field of robot technology. The parallel mechanism comprises: a fixed platform and a moving platform; a first branch chain, a second branch chain and a third branch chain are connected between the fixed platform and the moving platform; the first branch chain comprises: a rotating pair R11, a first connecting rod, a rotating pair R12 and a spiral pair H16, the rotating pair R11 and the rotating pair R12 are connected to the fixed platform, the rotating pair R11 is connected to the second connecting rod, the rotating pair R12 is connected to the third connecting rod, the spiral pair H16 is connected to the moving platform, the spiral pair H16 is connected to the fourth connecting rod, the first connecting rod is Y-shaped, and a moving pair P15 is movably connected to one of the branches of the first connecting rod, and the moving pair P15 is connected to the fourth connecting rod. The parallel mechanism of the present invention has two two-movement-one-spiral motion modes, which can realize the change of the working space of the moving platform by changing the motion mode without disassembling the mechanism, so that different performances are obtained in the common working space of the two same motion modes.

Description

Technical Field

[0001] The invention relates to the field of robot technology, and in particular to a three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes. Background Art

[0002] The parallel robot mechanism is a multi-loop closed chain with multiple degrees of freedom in space. Since the 1980s, the parallel mechanism has been widely used in industries such as virtual axis machine tools, micro-motion operation tables, motion simulators, and multi-dimensional force sensors due to its high rigidity, large load-bearing capacity, small cumulative error, good dynamic characteristics, and compact structure.

[0003] Currently, the working space of common multi-mode parallel mechanisms cannot be changed, and thus the performance of the mechanism cannot be changed within the working space. Summary of the invention

[0004] In order to solve the problems of the prior art, the present invention provides a three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes. The parallel mechanism comprises: a fixed platform and a moving platform;

[0005] A first branch chain, a second branch chain and a third branch chain are connected between the fixed platform and the movable platform;

[0006] The first branch chain includes: a revolute pair R11, a first connecting rod, a revolute pair R12 and a helical pair H16,

[0007] The revolving pair R11 and the revolving pair R12 are connected to the fixed platform, the revolving pair R11 is connected to a second connecting rod, the revolving pair R12 is connected to a third connecting rod, the helical pair H16 is connected to the moving platform, the helical pair H16 is connected to a fourth connecting rod,

[0008] The first connecting rod is Y-shaped, one of the branches of the first connecting rod is movably connected with a moving pair P15, the moving pair P15 is connected to the fourth connecting rod, and the other two branches of the first connecting rod are respectively connected to the second connecting rod and the third connecting rod through a rotating pair R13 and a rotating pair R14.

[0009] The second branch chain includes: a spiral pair H31 and a spiral pair H33, the spiral pair H31 is connected to the fixed platform, the spiral pair H33 is connected to the movable platform, the spiral pair H31 is connected to a fifth connecting rod, the fifth connecting rod is movably connected to a moving pair P32, the spiral pair H33 is connected to a sixth connecting rod, and the moving pair P32 is connected to the sixth connecting rod;

[0010] The third branch chain includes: a spiral pair H21 and a spiral pair H23, the spiral pair H21 is connected to the fixed platform, the spiral pair H23 is connected to the movable platform, the spiral pair H21 is connected to the seventh connecting rod, the seventh connecting rod is movably connected to the moving pair P22, the spiral pair H23 is connected to the eighth connecting rod, and the moving pair P22 is connected to the eighth connecting rod.

[0011] Furthermore, the axes of the revolving pairs R11, R12, R13 and R14 are parallel to the Z-axis direction.

[0012] Furthermore, the axis of the helical pair H16 is parallel to the Z-axis direction, and the moving direction of the moving pair P15 is perpendicular to the Z-axis.

[0013] Further, the distance from the axis of the revolving pair R11 to the axis of the revolving pair R13 is the same as the distance from the axis of the revolving pair R12 to the axis of the revolving pair R14;

[0014] The distance between the axis of the revolving pair R11 and the axis of the revolving pair R12 is the same as the distance between the axis of the revolving pair R13 and the axis of the revolving pair R14;

[0015] The distance from the axis of the revolving pair R11 to the axis of the revolving pair R13 is different from the distance from the axis of the revolving pair R11 to the axis of the revolving pair R12.

[0016] Furthermore, the axes of the helical pair H21 and the helical pair H23 are parallel to the Z-axis direction, and the moving direction of the moving pair P22 is perpendicular to the Z-axis.

[0017] Furthermore, the axes of the helical pair H31 and the helical pair H33 are parallel to the Z-axis direction, and the moving direction of the moving pair P32 is perpendicular to the Z-axis.

[0018] Furthermore, the spiral direction and pitch of the spiral pair H16, the spiral pair H21, the spiral pair H33, the spiral pair H31 and the spiral pair H23 are all the same.

[0019] Furthermore, the moving pair P15, the moving pair P32 and the moving pair P22 are connected with motors as moving driving pairs.

[0020] Furthermore, a motor is connected to the rotating pair R12 as an auxiliary rotating driving pair.

[0021] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention are as follows: the parallel mechanism of the present invention has two two-movement and one-spiral motion modes, namely two movements (movement in the XOY plane) and one spiral (the axis of the spiral motion is along the Z axis), which can achieve the change of the working space of the moving platform by changing the motion mode without disassembling the mechanism, thereby having different performances in the common working space of two identical motion modes; secondly, after the mechanism motion mode is switched, it can work in different working spaces, thereby increasing the working space of the mechanism; in addition, the working spaces of the two modes of the mechanism in the present invention are different, and their singular configurations are also different. Therefore, by realizing the transformation of the mechanism motion mode, the performance of the mechanism in some configurations when the working spaces of the two motion modes overlap can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a schematic diagram of a three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes provided by the present invention in a motion transformation mode;

[0024] Figure 2 It is a schematic diagram of a three-degree-of-freedom parallel mechanism with two-movement-one-screw motion modes provided by the present invention in a first two-movement-one-screw motion mode;

[0025] Figure 3 It is a schematic diagram of a three-degree-of-freedom parallel mechanism with two movements and one spiral motion mode provided by the present invention in a second two movements and one spiral motion mode.

[0026] Figure numerals: 1-fixed platform; 2-second connecting rod; 3-first connecting rod; 4-fourth connecting rod; 5-movable platform; 6-fifth connecting rod; 7-sixth connecting rod; 8-eighth connecting rod; 9-seventh connecting rod; 10-third connecting rod. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] A three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes comprises: a fixed platform 1 and a moving platform 5; a first branch chain, a second branch chain and a third branch chain are connected between the fixed platform 1 and the moving platform 5.

[0029] The first branch chain includes: a rotating pair R11, a first connecting rod 3, a rotating pair R12 and a helical pair H16, the rotating pair R11 and the rotating pair R12 are connected to the fixed platform 1, the rotating pair R11 is connected to the second connecting rod 2, the rotating pair R12 is connected to the third connecting rod 10, the helical pair H16 is connected to the moving platform 5, the helical pair H16 is connected to the fourth connecting rod 4, the first connecting rod 3 is Y-shaped, one of the branches of the first connecting rod 3 is movably connected to a mobile pair P15, the mobile pair P15 is connected to the fourth connecting rod 4, and the other two branches of the first connecting rod 3 are connected to the second connecting rod 2 and the third connecting rod 10 through the rotating pair R13 and the rotating pair R14 respectively; the rotating pair R11, The axes of the rotating pairs R12, R13 and R14 are parallel to the Z-axis direction, the axis of the helical pair H16 is parallel to the Z-axis direction, and the direction of movement of the movable pair P15 is perpendicular to the Z-axis; the distance from the axis of the rotating pair R11 to the axis of the rotating pair R13 is the same as the distance from the axis of the rotating pair R12 to the axis of the rotating pair R14, the distance from the axis of the rotating pair R11 to the axis of the rotating pair R12 is the same as the distance from the axis of the rotating pair R13 to the axis of the rotating pair R14, and the distance from the axis of the rotating pair R11 to the axis of the rotating pair R13 is different from the distance from the axis of the rotating pair R11 to the axis of the rotating pair R12; a motor is connected to the rotating pair R12 as an auxiliary rotating drive pair.

[0030] The second branch chain includes: a helical pair H31 and a helical pair H33, the helical pair H31 is connected to the fixed platform 1, the helical pair H33 is connected to the moving platform 5, the helical pair H31 is connected to the fifth connecting rod 6, the fifth connecting rod 6 is movably connected to the moving pair P32, the helical pair H33 is connected to the sixth connecting rod 7, the moving pair P32 is connected to the sixth connecting rod 7, the axes of the helical pair H31 and the helical pair H33 are parallel to the Z-axis direction, and the moving direction of the moving pair P32 is perpendicular to the Z-axis.

[0031] The third branch chain includes: a helical pair H21 and a helical pair H23, the helical pair H21 is connected to the fixed platform 1, the helical pair H23 is connected to the moving platform 5, the helical pair H21 is connected to the seventh connecting rod 9, the seventh connecting rod 9 is movably connected to the mobile pair P22, the helical pair H23 is connected to the eighth connecting rod 8, and the mobile pair P22 is connected to the eighth connecting rod 8; the axes of the helical pair H21 and the helical pair H23 are parallel to the Z-axis direction, and the moving direction of the mobile pair P22 is perpendicular to the Z-axis; the spiral rotation direction and pitch of the helical pair H16, the helical pair H21, the helical pair H33, the helical pair H31 and the helical pair H23 are the same, and the mobile pair P15, the mobile pair P32 and the mobile pair P22 are connected to motors as mobile drive pairs.

[0032] It should be noted that the two-movement-one-screw three-degree-of-freedom parallel mechanism of the present invention is Figure 1In the shown configuration, the mechanism moves into two modes of two-movement and one-screw motion, where the two movement motions are in the XOY plane and one screw motion is a rotation around the Z axis accompanied by a movement motion along the Z axis. Figure 1 The mechanism shown is in a constrained singular configuration, controlling the moving pair P15 in the first branch, the moving pair P22 in the second branch, the moving pair P32 in the third branch, and the auxiliary rotation drive pair R12, so that the moving platform 5 moves along the XOY plane. After the spiral motion around the Z axis, the moving platform 5 has two degrees of freedom of movement along the XOY plane and one degree of freedom of spiral motion around the Z axis. At this time, the mechanism is in Figure 2 In the configuration shown, the plane where the axes of the rotating pairs R11 and R13 are located is parallel to the plane where the axes of the rotating pairs R12 and R14 are located, and the plane where the axes of the movable pairs R13 and R14 are located does not coincide with the plane where the axes of the rotating pairs R11 and R12 are located. At this time, the parallel mechanism has three degrees of freedom, and the movable pair P15 in the first branch, the movable pair P22 in the third branch, and the movable pair P32 in the second branch can be controlled to control the parallel mechanism in the above-mentioned motion mode.

[0033] Figure 1 The mechanism shown is in a constrained singular configuration, controlling the moving pair P15 in the first branch, the moving pair P22 in the second branch, the moving pair P32 in the third branch, and the auxiliary rotation drive pair R12, so that the moving platform 5 moves along the XOY plane. After the spiral motion around the Z axis, the moving platform 5 has two degrees of freedom of movement along the XOY plane and one degree of freedom of spiral motion around the Z axis. At this time, the mechanism is in Figure 3 In the configuration shown, the second link 2 and the third link 10 are not in the same plane; at this time, the parallel mechanism has three degrees of freedom, which controls the moving pair P15 in the first branch, the moving pair P22 in the third branch, and the moving pair P32 in the second branch, and can control the parallel mechanism in the above motion mode. In addition, the parallel mechanism can be applied to the fields of motion simulation, machine assembly, sorting and grasping, parallel machine tools, etc.

[0034] It is worth mentioning that the parallel mechanism of the present invention has two two-movement and one-spiral motion modes, namely two movements (movement in the XOY plane) and one spiral (the axis of the spiral motion is along the Z axis), which can realize the change of the working space of the moving platform by changing the motion mode without disassembling the mechanism, thereby having different performances in the common working space of two identical motion modes; secondly, after the mechanism motion mode is switched, it can work in different working spaces, thereby increasing the working space of the mechanism; in addition, the working spaces of the two modes of the mechanism in the present invention are different, and their singular configurations are also different. Therefore, the performance of the mechanism in some configurations when the working spaces of the two motion modes overlap can be improved by realizing the transformation of the mechanism motion mode.

[0035] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes, characterized in that: The parallel mechanism comprises: a fixed platform (1) and a movable platform (5); A first branch chain, a second branch chain and a third branch chain are connected between the fixed platform (1) and the movable platform (5); The first branch chain comprises: a revolving pair R11, a first connecting rod (3), a revolving pair R12 and a helical pair H16, The revolving pair R11 and the revolving pair R12 are connected to the fixed platform (1), the revolving pair R11 is connected to a second connecting rod (2), the revolving pair R12 is connected to a third connecting rod (10), the helical pair H16 is connected to the moving platform (5), the helical pair H16 is connected to a fourth connecting rod (4), The first connecting rod (3) is Y-shaped, one of the branches of the first connecting rod (3) is movably connected with a movable pair P15, the movable pair P15 is connected to the fourth connecting rod (4), and the other two branches of the first connecting rod (3) are respectively connected to the second connecting rod (2) and the third connecting rod (10) through a rotating pair R13 and a rotating pair R14. The second branch chain comprises: a helical pair H31 and a helical pair H33, the helical pair H31 is connected to the fixed platform (1), the helical pair H33 is connected to the movable platform (5), the helical pair H31 is connected to a fifth connecting rod (6), the fifth connecting rod (6) is movably connected to a movable pair P32, the helical pair H33 is connected to a sixth connecting rod (7), and the movable pair P32 is connected to the sixth connecting rod (7); The third branch chain comprises: a helical pair H21 and a helical pair H23, the helical pair H21 is connected to the fixed platform (1), the helical pair H23 is connected to the movable platform (5), the helical pair H21 is connected to a seventh connecting rod (9), the seventh connecting rod (9) is movably connected to a movable pair P22, the helical pair H23 is connected to an eighth connecting rod (8), and the movable pair P22 is connected to the eighth connecting rod (8).

2. A three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes according to claim 1, characterized in that: The axes of the revolving pairs R11, R12, R13 and R14 are parallel to the Z-axis direction.

3. The three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes according to claim 1, characterized in that: The axis of the helical pair H16 is parallel to the Z-axis direction, and the moving direction of the moving pair P15 is perpendicular to the Z-axis.

4. The three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes according to claim 1, characterized in that: The distance between the axis of the revolving pair R11 and the axis of the revolving pair R13 is the same as the distance between the axis of the revolving pair R12 and the axis of the revolving pair R14; The distance between the axis of the revolving pair R11 and the axis of the revolving pair R12 is the same as the distance between the axis of the revolving pair R13 and the axis of the revolving pair R14; The distance from the axis of the revolving pair R11 to the axis of the revolving pair R13 is different from the distance from the axis of the revolving pair R11 to the axis of the revolving pair R12.

5. The three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes according to claim 1, characterized in that: The axes of the helical pair H21 and the helical pair H23 are parallel to the Z-axis direction, and the moving direction of the moving pair P22 is perpendicular to the Z-axis.

6. The three-degree-of-freedom parallel mechanism with two-movement-one-screw motion mode according to claim 1, characterized in that: The axes of the helical pair H31 and the helical pair H33 are parallel to the Z-axis direction, and the moving direction of the moving pair P32 is perpendicular to the Z-axis.

7. The three-degree-of-freedom parallel mechanism with two-movement-one-screw motion mode according to claim 1, characterized in that: The spiral direction and pitch of the spiral pair H16, the spiral pair H21, the spiral pair H33, the spiral pair H31 and the spiral pair H23 are all the same.

8. The three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes according to claim 1, characterized in that: The moving pair P15, the moving pair P32 and the moving pair P22 are connected with motors as moving driving pairs.

9. The three-degree-of-freedom parallel mechanism with two-movement and one-screw motion modes according to claim 1, characterized in that: The rotating pair R12 is connected to a motor as an auxiliary rotating driving pair.

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