CN109262592B - Two-translation one-rotation branch incomplete symmetrical parallel mechanism - Google Patents

Abstract

The invention relates to the technical field of parallel mechanisms, in particular to a two-translation one-rotation branch incompletely symmetrical parallel mechanism which comprises a movable platform and a fixed platform, wherein the fixed platform and the movable platform are in transmission connection through a first movable branched chain, a second movable branched chain and a third movable branched chain, and the first movable branched chain and the third movable branched chain are symmetrically arranged. And the mechanism has few joints, the total number of the freedom degrees of the kinematic pairs is only 13, and the problem that the parallel mechanism is easy to bend and deform in torsion due to excessive freedom degrees of the kinematic pairs can be effectively solved.

Description

Incomplete Symmetrical Parallel Mechanism with Two Translation and One Rotation Branches

technical field

The invention relates to a parallel structure, in particular to a two-translation-one-rotation branch incompletely symmetrical parallel mechanism.

Background technique

Compared with the traditional series mechanism, the parallel mechanism has the advantages of high stiffness, high bearing capacity, small cumulative error, and good dynamic performance. But in general, as the number of degrees of freedom increases, the number of branches will also increase accordingly, and the complexity of the control process will also increase accordingly. Therefore, in some occasions, the parallel mechanism with few degrees of freedom has high use value because of the few driving elements, the simple motion model and the low cost.

SUMMARY OF THE INVENTION

Aiming at the deficiencies in the prior art, the purpose of the present invention is to propose a two-translation-one-rotation branch incompletely symmetrical parallel mechanism, which has simple geometric structure, simple branch structure, small number of motion pairs, large working space, and easy control. , Easy to manufacture and assemble, high rigidity, strong bearing capacity, two translations and one rotation, and good movement flexibility.

The technical scheme of the present invention is as follows:

A two-translation-one-rotation branch incompletely symmetrical parallel mechanism, which comprises a moving platform, a fixed platform and three moving branches connecting the two platforms; the three moving branches are respectively a first moving branch and a second moving branch and the third movement branch; each movement branch comprises an upper link and a lower link respectively; each upper link is rotatably connected with its corresponding lower link; the upper link of the first movement branch is connected to the The platform is connected in rotation; the lower link of the first moving branch is hinged with the fixed platform; the upper link of the second moving branch is hinged with the moving platform, and the lower link of the second moving branch is connected The rod is hinged with the fixed platform; the upper link of the third moving branch is rotatably connected with the moving platform, and the lower link of the third moving branch is hinged with the fixed platform.

Preferably, the first end of the upper link in the first moving branch is hinged with the moving platform through a first rotation pair, and the second end of the upper link is connected with the lower link through a second rotation pair The first end of the lower link is hinged, and the second end of the lower link is connected to the fixed platform through a first universal hinge.

Preferably, the first universal hinge includes a rotating pair away from the fixed platform and a rotating pair close to the fixed platform, the axis of the first rotating pair, the axis of the second rotating pair, the The axes of the rotation pairs of the first universal joint away from the fixed platform are all parallel.

Preferably, the first end of the upper link in the second moving branch is connected to the moving platform through a third universal joint, and the second end of the upper link is connected to the lower link through a third rotation pair The first end of the lower link is hinged, and the second end of the lower link is connected to the fixed platform through a second universal hinge.

Preferably, the third universal hinge includes a rotation pair close to the moving platform and a rotation pair away from the moving platform, and the second universal hinge includes a rotation pair close to the fixed platform and a rotation pair away from the moving platform. The rotation pair of the fixed platform; the axis of the third rotation pair, the axis of the second universal hinge away from the fixed platform and the third universal hinge away from the moving platform axes are parallel to each other.

Preferably, the first end of the upper link in the third moving branch is hinged to the moving platform through a fifth rotation pair, and the second end of the upper link is connected to the first link through the fourth rotation pair and the lower link. One end is hinged, and the second end of the lower link is connected with the fixed platform through a fourth universal hinge.

Preferably, the fourth universal hinge includes a rotation pair away from the fixed platform and a rotation pair close to the fixed platform, the axis of the fourth rotation pair, the axis of the fifth rotation pair and the fourth rotation pair The axes of the rotating pairs of the hinges away from the fixed platform are all parallel to each other.

Preferably, the axis of the rotation pair of the third movement branch close to the fixed platform and the axis of the rotation pair of the first movement branch close to the fixed platform, the second movement branch close to the axis of the rotation pair of the fixed platform The axes of the rotating pair of the fixed platform are parallel.

The beneficial effects of the present invention are as follows:

1. The two-translation-one-rotation branch in the present invention is not completely symmetrical, and the kinematic pair of the parallel mechanism is simple in configuration, easy to manufacture and install, high in transmission precision, and low in cost.

2. The two-translation-one-rotation branch incompletely symmetrical parallel mechanism in the present invention belongs to an asymmetric parallel mechanism. Compared with the symmetrical parallel mechanism, the working space is larger and the movement flexibility is good.

3. In the present invention, the two-translation-rotation branch is not completely symmetrical parallel mechanism has few joints, and the total number of degrees of freedom of the kinematic pair is only 13, which can effectively improve the parallel mechanism that is prone to deflection and torsional deformation due to the excessive freedom of the kinematic pair. The problem.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic structural diagram of an incompletely symmetrical parallel mechanism with two translation and one rotation branches according to the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Please refer to FIG. 1 , wherein FIG. 1 is a schematic structural diagram of an incompletely symmetrical parallel mechanism with two translation and one rotation branches of the present invention. The present invention provides an incompletely symmetrical parallel mechanism with two translation and one rotation branches, which includes a moving platform 1 and a fixed platform 2. The fixed platform 2 and the moving platform 1 pass through a first moving branch, a second moving branch and a third moving branch. The transmission is connected, and the first moving branch chain and the third moving branch chain are symmetrically arranged.

One end of the upper link 4 in the first moving branch is hinged with the moving platform 1 through the rotating pair 3, and the other end of the upper link 4 is hinged with one end of the lower link 6 through the rotating pair 5, and the lower link 6 is hinged. The other end is connected to the fixed platform 2 through the first universal hinge 7 . The first universal hinge 7 includes a rotating pair away from the fixed platform 2 and a rotating pair close to the fixed platform 2, the axis of the rotating pair 3, the axis of the rotating pair 5 and the rotating pair of the first universal hinge 7 away from the fixed platform 2. axes are parallel to each other.

One end of the upper link 11 in the second movement branch is connected to the moving platform 1 through the third universal hinge 12, the other end of the upper link 11 is hinged with one end of the lower link 9 through the rotating pair 10, and the lower link 9 The other end is connected with the fixed platform 2 through the second universal hinge 8 . The second universal hinge 8 includes a rotation pair close to the fixed platform 2 and a rotation pair away from the fixed platform 2 , and the third universal hinge 12 includes a rotation pair close to the movable platform 1 and a rotation pair away from the movable platform 1 . The axis of the rotating pair 10 , the axis of the rotating pair of the third universal joint 12 away from the moving platform 1 and the axis of the rotating pair of the second universal hinge 8 away from the fixed platform 2 are all parallel to each other.

One end of the upper link 14 in the third movement branch is hinged with the moving platform 1 through the rotating pair 13 , the other end of the upper link 14 is hinged with one end of the lower link 16 through the rotating pair 15 , and the other end of the lower link 16 is hinged. One end is connected with the fixed platform 2 through the fourth universal hinge 17 . The fourth universal joint 17 includes a rotating pair away from the fixed platform 2 and a rotating pair close to the fixed platform 2 . The axis of the fourth rotating pair 15 , the axis of the fifth rotating pair 13 and the axis of the rotating pair of the fourth universal joint 17 away from the fixed platform 2 are all parallel to each other. The axis of the rotating pair of the third moving branch close to the fixed platform 2 is parallel to the axis of the rotating pair of the first moving branch close to the fixed platform 2 and the axis of the rotating pair of the second moving branch close to the fixed platform 2 .

Specifically, according to the two-translation-rotation branch incomplete symmetrical parallel mechanism of the present invention, the first moving branch chain and the third moving branch chain are symmetrically arranged on both sides of the movable platform 1 and the fixed platform 2 respectively. The second movement branch is located between the first movement branch and the third movement branch.

A first connecting piece is provided on the left side of the edge of the moving platform 1 , and the first connecting piece is integrally formed with the moving platform 1 , and can also be connected to the edge of the moving platform 1 by welding or by fasteners.

The first moving branch includes a first upper link and a first lower link, a second connecting piece is provided at the first end of the first upper link, and the first connecting piece and the second connecting piece are connected, for example, by a pin The shaft is connected so that the first connecting piece and the second connecting piece can rotate relative to each other.

The second end of the first upper connecting rod is provided with a third connecting piece, the first end of the first lower connecting rod is provided with a fourth connecting piece, and between the fourth connecting piece and the third connecting piece, for example, through a pin shaft, The connection is made so that the third connecting piece and the fourth connecting piece can rotate relative to each other.

The second end of the first lower link is provided with a fifth connecting piece, and the left edge of the fixed platform is provided with a sixth connecting piece. The sixth connecting piece is integrally formed with the fixed platform 2, or can be welded or tightened. The firmware is attached to the edge of the fixed platform 2. The fifth connecting piece is connected with the first end of the first universal hinge 7, and the second end of the first universal hinge 7 is connected with the sixth connecting piece.

The middle edge of the moving platform 1 is provided with a seventh connecting piece, and the seventh connecting piece is integrally formed with the moving platform 1 , and can also be connected to the edge of the moving platform 1 by welding or by fasteners.

The second moving branch includes a second upper link and a second lower link, the first end of the second upper link is provided with an eighth connecting piece, and the seventh connecting piece is connected to the first end of the third universal hinge 12 , the second end of the third universal hinge 12 is connected with the eighth connecting piece.

The second end of the second upper link is provided with a ninth connector, and the first end of the second lower link is provided with a tenth connector. Between the ninth connector and the tenth connector, for example, through a pin, The connection is made so that the ninth connecting piece and the tenth connecting piece can rotate relative to each other.

The second end of the second lower connecting rod is provided with an eleventh connector, and the middle edge of the fixed platform 2 is provided with a twelfth connector. The twelfth connector is integrally formed with the fixed platform 2, or it can be welded Or connected to the edge of the fixed platform 2 by fasteners. The eleventh connecting piece is connected with the first end of the second universal hinge 8, and the second end of the second universal hinge 8 is connected with the twelfth connecting piece.

The third kinematic branch is connected in exactly the same way as the first kinematic branch.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. Those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions. It departs from the scope of the technical solutions of the embodiments of the present invention.

Claims (2)

1. an incomplete symmetrical parallel mechanism with two translation and one rotation branches, it is characterized in that, it comprises three movement branches that move platform, fixed platform and connect two platforms; Three movement branches are respectively the first movement branch , the second movement branch chain and the third movement branch chain; each movement branch chain includes an upper link and a lower link respectively; each upper link is respectively connected with its corresponding lower link in rotation; the upper link of the first movement branch The connecting rod is rotatably connected with the moving platform; the lower connecting rod of the first moving branch is hinged with the fixed platform; the upper connecting rod of the second moving branch is hinged with the moving platform, and the second moving branch is hinged with the moving platform. The lower link of the moving branch is hinged to the fixed platform; the upper link of the third moving branch is rotatably connected to the moving platform, and the lower link of the third moving branch is hinged to the fixed platform ; The first end of the upper link in the first moving branch is hinged with the moving platform through the first rotation pair, and the second end of the upper link is connected with the first rotation pair of the lower link through the second rotation pair. The ends are hinged, and the second end of the lower link is connected to the fixed platform through a first universal hinge; The first universal hinge includes a rotating pair away from the fixed platform and a rotating pair close to the fixed platform, the axis of the first rotating pair, the axis of the second rotating pair, the first universal joint The axes of the rotating pairs of the hinges away from the fixed platform are all parallel; The first end of the upper link in the second movement branch is connected to the moving platform through a third universal hinge, and the second end of the upper link is connected to the first end of the lower link through a third rotation pair. The ends are hinged, and the second end of the lower link is connected to the fixed platform through a second universal hinge; The third universal hinge includes a rotation pair close to the movable platform and a rotation pair away from the movable platform, and the second universal hinge includes a rotation pair away from the fixed platform and a rotation pair close to the fixed platform The axis of the third rotation pair, the axis of the second universal hinge away from the fixed platform and the axis of the third universal hinge away from the moving platform are all mutually parallel; The first end of the upper link in the third movement branch is hinged with the moving platform through the fifth rotation pair, and the second end of the upper link is hinged with the first end of the lower link through the fourth rotation pair , the second end of the lower link is connected with the fixed platform through the fourth universal hinge; The fourth universal hinge includes a rotation pair away from the fixed platform and a rotation pair close to the fixed platform, the axis of the fourth rotation pair, the axis of the fifth rotation pair and the distance between the fourth universal hinge The axes of the rotating pairs of the fixed platform are all parallel to each other. 2. The incompletely symmetrical parallel mechanism of two translation and one rotation branches as claimed in claim 1, wherein the axis of the rotation pair of the third moving branch close to the fixed platform and the first moving branch The axis of the rotating pair close to the fixed platform and the axis of the rotating pair of the second movement branch close to the fixed platform are parallel.

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