Three-degree-of-freedom parallel robot comprising planar four-bar mechanism

Abstract

The invention discloses a three-degree-of-freedom parallel robot comprising a planar four-bar mechanism. A first horizontal rotating shaft, a first vertical rotating shaft, a first connecting rod, a second connecting rod, a first core shaft, a first linear feeding device, a first connecting plate and a first motor form a first motion branch chain; the second movement branch chain, the third movement branch chain and the first movement branch chain are the same in structure. The first linear feeding device is connected with the static platform through a first connecting plate; the first mandrel is connected to the first saddle through a hinge, and the two ends of the first mandrel are connected to one end of the first connecting rod and one end of the second connecting rod through hinges respectively. The two ends of the first vertical rotating shaft are connected to the other ends of the first connecting rod and the second connecting rod through hinges correspondingly. The other end of the first vertical rotating shaft is connected to the first horizontal rotating shaft through a hinge; the two sides of the first horizontal rotating shaft are connected to the movable platform through hinges. A special-shaped connecting rod can be effectively avoided, and the manufacturing difficulty and cost are reduced.

Description

Technical Field

[0001] The present invention relates to the field of robots, and particularly to a three-degree-of-freedom parallel robot with a planar four-bar mechanism. Technical Background

[0002] At present, three-degree-of-freedom parallel robots with two rotational degrees of freedom and one translational degree of freedom are a very important type in the parallel mechanisms with few degrees of freedom. Such parallel mechanisms have the advantages of a large stiffness-to-mass ratio, strong load capacity, and compact structure, and can more effectively save the costs of system design, manufacturing, and control in machining applications such as metal cutting.

[0003] The parallel mechanism disclosed in the US Patent US6431802B1 is a three-degree-of-freedom parallel robot, which is installed in a barrel-shaped spindle box. Three mutually parallel linear drive devices are radially arranged. The moving platform is connected to the linear drive devices through connecting rods. One end of the connecting rod is connected to a linear feed device composed of a saddle, a guide rail slider pair, and a ball screw pair through a saddle, and the other end is connected to the moving platform through a spherical hinge pair. An electric spindle is installed on the moving platform. However, one end of the connecting rod of this robot is directly connected to the saddle through a rotating pair, making it difficult to achieve lightweight design for the connecting rod. And to avoid interference, it is usually designed as a special-shaped connecting rod, which is difficult to machine. At the same time, the spherical hinge pair is composed of three rotating pairs with mutually orthogonal and intersecting rotation axes at one point, making the rotating pair connected to the connecting rod part a cantilever beam structure, with a complex structure and difficult to ensure the overall machine stiffness and assembly accuracy. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a three-degree-of-freedom parallel robot with a planar four-bar mechanism.

[0005] The technical solution adopted by the present invention is: a three-degree-of-freedom parallel robot with a planar four-bar mechanism, including a first horizontal rotating shaft, a first vertical rotating shaft, a first connecting rod, a second connecting rod, a first core shaft, a first linear feed device, a first connecting plate, and a first motor to form a first motion branch chain. The first linear feed device is composed of a first saddle, a first guide rail slider pair, and a first ball screw nut pair; a second horizontal rotating shaft, a second vertical rotating shaft, a third connecting rod, a fourth connecting rod, a second core shaft, a second linear feed device, a second connecting plate, and a second motor form a second motion branch chain. The second linear feed device is composed of a second saddle, a second guide rail slider pair, and a second ball screw nut pair; a third horizontal rotating shaft, a third vertical rotating shaft, a fifth connecting rod, a sixth connecting rod, a third core shaft, a third linear feed device, a third connecting plate, and a third motor form a third motion branch chain. The third linear feed device is composed of a third saddle, a third guide rail slider pair, and a third ball screw nut pair; the first motion branch chain, the second motion branch chain, and the third motion branch chain have the same structure.

[0006] The first linear feed device (second linear feed device / third linear feed device) is connected to the static platform through the first connecting plate (second connecting plate / third connecting plate); the first mandrel (second mandrel / third mandrel) is connected to the first saddle (second saddle / third saddle) through a hinge with one rotational degree of freedom, and the two ends are respectively connected to one end of the first connecting rod (third connecting rod / fifth connecting rod) and the second connecting rod (fourth connecting rod / sixth connecting rod) through hinges with one rotational degree of freedom; the two ends of the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft) are respectively connected to the other ends of the first connecting rod (third connecting rod / fifth connecting rod) and the second connecting rod (fourth connecting rod / sixth connecting rod) through hinges with one rotational degree of freedom; the other end of the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft) is connected to the first horizontal rotating shaft (second horizontal rotating shaft / third horizontal rotating shaft) through a hinge with one rotational degree of freedom; both sides of the first horizontal rotating shaft (second horizontal rotating shaft / third horizontal rotating shaft) are connected to the moving platform through hinges with one rotational degree of freedom.

[0007] The two rotational axes connecting the first mandrel (second mandrel / third mandrel) to the first connecting rod (third connecting rod / fifth connecting rod) and the second connecting rod (fourth connecting rod / sixth connecting rod) are parallel to each other; the rotational axis connecting the first mandrel (second mandrel / third mandrel) to the first saddle (second saddle / third saddle) and the rotational axis connecting the first mandrel (second mandrel / third mandrel) to the first connecting rod (third connecting rod / fifth connecting rod) are perpendicular and intersect; the moving planes of the first mandrel (second mandrel / third mandrel), the first connecting rod (third connecting rod / fifth connecting rod), the second connecting rod (fourth connecting rod / sixth connecting rod), and the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft) are in the same plane; the rotational axis connecting the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft) to the first connecting rod (third connecting rod / fifth connecting rod) and the second connecting rod (fourth connecting rod / sixth connecting rod) and the rotational axis connecting the first horizontal rotating shaft (second horizontal rotating shaft / third horizontal rotating shaft) and the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft) are perpendicular but do not intersect; the rotational axis connecting the first horizontal rotating shaft (second horizontal rotating shaft / third horizontal rotating shaft) and the moving platform and the rotational axis connecting the first horizontal rotating shaft (second horizontal rotating shaft / third horizontal rotating shaft) and the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft) are perpendicular and intersect.

[0008] The linear drive devices formed by the first linear feed device and the first connecting plate, the second linear feed device and the second connecting plate, and the third linear feed device and the third connecting plate include the following linear drive forms: motor screw, pneumatic or hydraulic device.

[0009] The three-degree-of-freedom parallel robot with a planar four-bar mechanism of the present invention has the following advantages and positive effects:

[0010] 1. Compared with the mechanism disclosed in Patent US6431802B1, the planar four-bar mechanism composed of the first core shaft (second core shaft / third core shaft), the first connecting rod (third connecting rod / fifth connecting rod), and the second connecting rod (fourth connecting rod / sixth connecting rod) can effectively avoid special-shaped connecting rods, reduce the manufacturing difficulty and cost, and is beneficial to realizing the lightweight design of the mechanism, thereby improving the machining performance of the machine tool.

[0011] 2. The mounting holes on the horizontal rotating shaft and the vertical rotating shaft are both in the horizontal or vertical direction, having good manufacturing and assembly process performance.

[0012] 3. The four-bar structure formed between the first horizontal rotating shaft (second horizontal rotating shaft / third horizontal rotating shaft), the first vertical rotating shaft (second vertical rotating shaft / third vertical rotating shaft), the first connecting rod (third connecting rod / fifth connecting rod), and the second connecting rod (fourth connecting rod / sixth connecting rod) avoids the connection method between the moving platform through a cantilever structure, which is beneficial to improving the machining performance of the mechanism. Brief Description of the Drawings

[0013] Figure 1 is one of the structural schematic diagrams of the present invention;

[0014] Figure 2 is the structural schematic diagram of the branch chain of the three-degree-of-freedom parallel robot with a planar four-bar mechanism of the present invention;

[0015] Figure 3 is an embodiment of the present invention. Detailed Description of the Invention

[0016] The three-degree-of-freedom parallel robot with a planar four-bar mechanism of the present invention will be described in more detail in combination with the embodiments and the drawings.

[0017] As Figures 1-3As shown in the figure, a three-degree-of-freedom parallel robot includes a first horizontal rotating shaft 11, a first vertical rotating shaft 12, a first connecting rod 13, a second connecting rod 24, a first core shaft 15, a first saddle 16, a first guide rail slider pair 17, a first lead screw nut pair 18, a first connecting plate 19, a first motor 10, a second horizontal rotating shaft 21, a second vertical rotating shaft 22, a third connecting rod 33, a fourth connecting rod 44, a second core shaft 25, a second saddle 26, a second guide rail slider pair 27, a second lead screw nut pair 28, a second connecting plate 29, a second motor 20, a third horizontal rotating shaft 31, a third vertical rotating shaft 32, a fifth connecting rod 53, a sixth connecting rod 64, a third core shaft 35, a third saddle 36, a third guide rail slider pair 37, a third lead screw nut pair 38, a third connecting plate 39 and a third motor 30;

[0018] The first horizontal rotating shaft 11, the first vertical rotating shaft 12, the first connecting rod 13, the second connecting rod 24, the first core shaft 15, the first saddle 16, the first guide rail slider pair 17, the first lead screw nut pair 18, the first connecting plate 19 and the first motor 10 form a first kinematic chain; the second horizontal rotating shaft 21, the second vertical rotating shaft 22, the third connecting rod 33, the fourth connecting rod 44, the second core shaft 25, the second saddle 26, the second guide rail slider pair 27, the second lead screw nut pair 28, the second connecting plate 29 and the second motor 20 form a second kinematic chain; the third horizontal rotating shaft 31, the third vertical rotating shaft 32, the fifth connecting rod 53, the sixth connecting rod 64, the third core shaft 35, the third saddle 36, the third guide rail slider pair 37, the third lead screw nut pair 38, the third connecting plate 39 and the third motor 30 form a third kinematic chain; the first kinematic chain, the second kinematic chain and the third kinematic chain have the same structure; the first saddle 16, the first guide rail slider pair 17 and the first lead screw nut pair 18 form a first feeding device; the second saddle 26, the second guide rail slider pair 27 and the second lead screw nut pair 28 form a second feeding device; the third saddle 36, the third guide rail slider pair 37 and the third lead screw nut pair 38 form a third feeding device.

[0019] The first linear feed device (the second linear feed device / the third linear feed device) is connected to the static platform 1 through the first connecting plate 19 (the second connecting plate 29 / the third connecting plate 39); the first mandrel 15 (the second mandrel 25 / the third mandrel 35) is connected to the first saddle 16 (the second saddle 26 / the third saddle 36) through a hinge with one rotational degree of freedom, and both ends are respectively connected to one end of the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53) and the second connecting rod 24 (the fourth connecting rod 44 / the sixth connecting rod 64) through hinges with one rotational degree of freedom; the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) is respectively connected to the other ends of the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53) and the second connecting rod 24 (the fourth connecting rod 44 / the sixth connecting rod 64) through hinges with one rotational degree of freedom; the other end of the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) is connected to the first horizontal rotating shaft 11 (the second horizontal rotating shaft 21 / the third horizontal rotating shaft 31) through a hinge with one rotational degree of freedom; both sides of the first horizontal rotating shaft 11 (the second horizontal rotating shaft 21 / the third horizontal rotating shaft 31) are connected to the moving platform 2 through hinges with one rotational degree of freedom.

[0020] The two rotational axes connecting the first mandrel 15 (the second mandrel 25 / the third mandrel 35) to the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53) and the second connecting rod 24 (the fourth connecting rod 44 / the sixth connecting rod 64) and the two rotational axes connecting the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) to the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53) and the second connecting rod 24 (the fourth connecting rod 44 / the sixth connecting rod 64) are parallel to each other; the rotational axis connecting the first mandrel 15 (the second mandrel 25 / the third mandrel 35) to the first saddle 16 (the second saddle 26 / the third saddle 36) and the rotational axis connecting the first mandrel 15 (the second mandrel 25 / the third mandrel 35) to the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53) are perpendicular and intersect; the moving planes of the first mandrel 15 (the second mandrel 25 / the third mandrel 35), the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53), the second connecting rod 24 (the fourth connecting rod 44 / the sixth connecting rod 64) and the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) are in the same plane; the rotational axis connecting the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) to the first connecting rod 13 (the third connecting rod 33 / the fifth connecting rod 53) and the second connecting rod 24 (the fourth connecting rod 44 / the sixth connecting rod 64) and the rotational axis connecting the first horizontal rotating shaft 11 (the second horizontal rotating shaft 21 / the third horizontal rotating shaft 31) and the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) are perpendicular but do not intersect; the rotational axis connecting the first horizontal rotating shaft 11 (the second horizontal rotating shaft 21 / the third horizontal rotating shaft 31) and the moving platform 2 and the rotational axis connecting the first horizontal rotating shaft 11 (the second horizontal rotating shaft 21 / the third horizontal rotating shaft 31) and the first vertical rotating shaft 12 (the second vertical rotating shaft 22 / the third vertical rotating shaft 32) are perpendicular and intersect;

[0021] The linear drive device formed by the first linear feed device and the first connecting plate 19, the second linear feed device and the second connecting plate 29, and the third linear feed device and the third connecting plate 39 includes the following linear drive forms: motor screw, pneumatic or hydraulic device.

[0022] Embodiment: Install the three-degree-of-freedom parallel robot module with the planar four-bar mechanism on the linear guide rail to form a robot workstation as shown Figure 3 in the figure.

[0023] Although the present invention has been described in detail above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit of the present invention and the scope protected by the claims. These all belong to the protection scope of the present invention.

Claims

1. A three-degree-of-freedom parallel robot with a planar four-bar mechanism, comprising a static platform (1) and a dynamic platform (2); characterized in that: The first horizontal rotating shaft (11), the first vertical rotating shaft (12), the first connecting rod (13), the second connecting rod (24), the first core shaft (15), the first linear feed device, the first connecting plate (19), and the first motor (10) form a first motion branch chain, wherein the first linear feed device is composed of a first slide saddle (16), a first guide rail slider pair (17) and a first lead screw nut pair (18); the second horizontal rotating shaft (21), the second vertical rotating shaft (22), the third connecting rod (33), and the fourth connecting rod (44) The second motion branch chain is composed of a second spindle (25), a second linear feed device, a second connecting plate (29), and a second motor (20), wherein the second linear feed device is composed of a second slide saddle (26), a second guide rail slider pair (27), and a second lead screw nut pair (28); the third horizontal rotating shaft (31), the third vertical rotating shaft (32), a fifth connecting rod (53), a sixth connecting rod (64), a third spindle (35), a third linear feed device, a third connecting plate (39), and a third motor (30) The third motion branch chain, the third linear feed device is composed of a third slide saddle (36), a third guide rail slider pair (37) and a third screw nut pair (38); the first motion branch chain, the second motion branch chain and the third motion branch chain have the same structure; the first linear feed device is connected to the static platform (1) through a first connecting plate (19); the first core shaft (15) is connected to the first slide saddle (16) through a hinge with a rotational freedom, and the two ends of the first core shaft are respectively connected to one end of the first connecting rod (13) and the second connecting rod (24) through a hinge with a rotational freedom; one axial side of the first vertical rotating shaft (12) is respectively connected to the other end of the first connecting rod (13) and the second connecting rod (24) through a hinge with a rotational freedom; the other axial side of the first vertical rotating shaft (12) is connected to the first horizontal rotating shaft (11) through a hinge with a rotational freedom; both sides of the first horizontal rotating shaft (11) are connected to the moving platform (2) through hinges with a rotational freedom; The two rotation axes connecting the first core shaft (15) with the first connecting rod (13) and the second connecting rod (24) and the two rotation axes connecting the first vertical rotating shaft (12) with the first connecting rod (13) and the second connecting rod (24) are parallel to each other; the rotation axis connecting the first core shaft (15) with the first sliding saddle (16) and the rotation axis connecting the first core shaft (15) with the first connecting rod (13) are perpendicular to and intersect with each other; the movement planes of the first core shaft (15), the first connecting rod (13), the second connecting rod (24) and the first vertical rotating shaft (12) are the same plane; the rotation axis connecting the first vertical rotating shaft (12) with the first connecting rod (13) and the second connecting rod (24) are perpendicular to but do not intersect with the rotation axis connecting the first horizontal rotating shaft (11) and the first vertical rotating shaft (12); the rotation axis connecting the first horizontal rotating shaft (11) and the movable platform (2) are perpendicular to and intersect with the rotation axis connecting the first horizontal rotating shaft (11) and the first vertical rotating shaft (12).

2. The three-degree-of-freedom parallel robot with a planar four-bar mechanism according to claim 1, characterized in that: The linear drive device formed by the first linear feed device and the first connecting plate (19), the second linear feed device and the second connecting plate (29), and the third linear feed device and the third connecting plate (39) includes the following linear drive forms: motor screw, pneumatic or hydraulic device.

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