CN114083517A

CN114083517A - Parallel mechanism

Info

Publication number: CN114083517A
Application number: CN202111417066.7A
Authority: CN
Inventors: 孙月海
Original assignee: Institute Of Medical Robot And Intelligent System Tianjin University
Current assignee: Institute Of Medical Robot And Intelligent System Tianjin University
Priority date: 2021-11-25
Filing date: 2021-11-25
Publication date: 2022-02-25

Abstract

The present disclosure provides a parallel mechanism, comprising: the fixed platform, the shaft seat part, the supporting chain part, the supporting arm and the movable platform; the shaft seat part is arranged on the fixed platform; the two branch chain parts are symmetrically arranged; the first end of the branch chain part is connected with the shaft seat part, and the second end of the branch chain part is connected with the movable platform; the first end of the supporting arm is connected with the shaft seat, and the second end of the supporting arm is connected with the movable platform. The movable platform has 2 degrees of freedom in space and rotates around a first shaft and a second shaft respectively; wherein the first axis and the second axis are perpendicular.

Description

Parallel mechanism

Technical Field

The disclosure relates to the field of medical robots, in particular to a parallel mechanism.

Background

The parallel mechanism generally refers to a motion mechanism of a multi-closed-loop motion chain with 2-6 degrees of freedom. Compared with a series mechanism, the mechanical arm has the characteristics of large rigidity/mass ratio, convenience for modular design and the like, and is widely applied to various aspects such as industrial robots, numerical control machines, motion simulators, medical robots, precision positioning devices in microelectronic manufacturing and the like.

Disclosure of Invention

Technical problem to be solved

The present disclosure provides a parallel mechanism to solve the technical problems set forth above.

(II) technical scheme

According to an aspect of the present disclosure, there is provided a parallel mechanism including:

the shaft seat part is arranged on the fixed platform;

the first ends of the branch chain parts are connected with the shaft seat part, and the two branch chain parts are symmetrically arranged;

the first end of the supporting arm is connected with the shaft seat part;

the movable platform is connected with the second end of the supporting chain part and the second end of the supporting arm and rotates around a first shaft and a second shaft respectively; wherein the first axis and the second axis are perpendicular.

In some embodiments of the present disclosure, the shaft seating portion includes:

the first shaft seat is connected with the supporting arm;

the second shaft seat and the third shaft seat are respectively connected with the first end of one branched chain part;

the first shaft seat, the second shaft seat and the third shaft seat are arranged on the fixed platform; the rotating shafts of the second shaft seat and the third shaft seat are symmetrically arranged relative to the rotating shaft of the first shaft seat, and the rotating shafts of the first shaft seat, the second shaft seat and the third shaft seat are intersected at a central point.

In some embodiments of the present disclosure, the support arm is an L-shaped structure, the support arm comprising:

the shaft hole is formed in the first end of the supporting arm;

the first end of the first cross shaft is in pivot connection with the shaft hole, and the second end of the first cross shaft is in pivot connection with the shaft seat.

In some embodiments of the present disclosure, the branched moiety comprises:

the first end of the first arm is coaxially connected with the shaft seat part;

a second arm, the first arm sidewall pivotally connected to the second arm first end; the rotating shafts at two ends of the first arm are vertical and intersected;

a third arm, the second arm second end pivotally connected to the third arm first end; rotating shafts at two ends of the second arm are arranged in parallel;

a fourth arm, a second end of the third arm pivotally connected to a first end of the fourth arm by a second cross; the second end of the fourth arm is rotatably connected with the movable platform; and rotating shafts at two ends of the third arm are vertically arranged.

In some embodiments of the present disclosure, further comprising: and the external equipment is connected with any two of the first shaft seat, the second shaft seat and the third shaft seat.

In some embodiments of the present disclosure, the external device is a drive motor and/or a motion sensor.

In some embodiments of the present disclosure, when the movable platform is driven passively, the external device is respectively installed at the second shaft seat and the third shaft seat, and is configured to drive the branch chain portion to rotate around the second shaft seat or the third shaft seat.

In some embodiments of the present disclosure, when the movable platform is driven passively, the driving device is installed at a position of the pivotal connection in the branched portion.

In some embodiments of the present disclosure, when the movable platform is actively driven, at least one of the external devices is installed at the first shaft seat.

(III) advantageous effects

According to the technical scheme, the parallel mechanism disclosed by the invention has at least one or part of the following beneficial effects:

the parallel mechanism provided by the disclosure has 2 degrees of freedom in space, and two virtual restraint branch chain parts are arranged, so that greater load capacity is provided for the movable platform.

Drawings

Fig. 1 is a schematic diagram of a parallel mechanism according to an embodiment of the disclosure.

Fig. 2 is a schematic diagram of the rotation axes of the first shaft seat, the second shaft seat and the third shaft seat in fig. 1 meeting at a central point.

Fig. 3 is a schematic diagram of a motion characteristic of a parallel mechanism according to an embodiment of the disclosure.

Fig. 4 is a schematic diagram of a parallel mechanism support arm according to an embodiment of the disclosure.

FIG. 5 is a schematic diagram of a branched chain portion of a parallel linkage according to an embodiment of the disclosure.

Fig. 6 is a schematic diagram of an external device installation manner of the parallel mechanism according to the embodiment of the disclosure.

Fig. 7 is a schematic view of another external device installation manner of the parallel mechanism according to the embodiment of the disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is illustrative only and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.

Where a convention analogous to "at least one of A, B and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B and C" would include but not be limited to systems that have a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.). Where a convention analogous to "A, B or at least one of C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B or C" would include but not be limited to systems that have a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.).

The present disclosure provides a parallel mechanism, comprising: the fixed platform, the shaft seat part, the supporting chain part, the supporting arm and the movable platform; the shaft seat part is arranged on the fixed platform; the two branch chain parts are symmetrically arranged; the first end of the branch chain part is connected with the shaft seat part, and the second end of the branch chain part is connected with the movable platform; the first end of the supporting arm is connected with the shaft seat, and the second end of the supporting arm is connected with the movable platform; the movable platform rotates around a first shaft and a second shaft respectively; wherein the first axis and the second axis are perpendicular.

Fig. 1 is a schematic diagram of a parallel mechanism according to an embodiment of the disclosure. As shown in fig. 1, the present embodiment provides a parallel mechanism including: a fixed platform 01, a movable platform 02, a branch chain part and the like. For the sake of convenience of distinction, the two branched portions are respectively shown as a first branched portion 03, a second branched portion 04, and the like. The fixed platform 01 is used for mounting all parts of the parallel structure, and three shaft seats, namely a first shaft seat 05, a second shaft seat 06 and a third shaft seat 07 are mounted above the fixed platform. The second shaft holder 06 and the third shaft holder 07 are symmetrically arranged with the rotation shaft of the first shaft holder 05 as a symmetry axis. The three-axis base rotating shaft intersects at a point O, as shown in figure 2.

Fig. 3 is a schematic diagram of a motion characteristic of a parallel mechanism according to an embodiment of the disclosure. As shown in fig. 3, the movable platform 02 has 2 degrees of freedom in space, which are respectively rotation around the x-axis (i.e., the first axis) and rotation around the y-axis (i.e., the second axis) as shown in the coordinate system on the figure.

Fig. 4 is a schematic diagram of a parallel mechanism support arm according to an embodiment of the disclosure. As shown in fig. 4, a support arm 08 is fixedly mounted below the movable platform 02, a shaft hole 09 for mounting a rotating shaft is provided in the support arm 08, a first shaft a of the first cross 10 is mounted in the shaft hole 09, a second shaft b of the first cross 10 is mounted in the shaft hole of the first boss 05, and the first cross 10 is rotatable in the shaft hole 09. The movable platform 02 is further provided with a first branched shaft hole 11 and a second branched shaft hole 12 for mounting the first branched part 03 and the second branched part 04, respectively.

FIG. 5 is a schematic diagram of a branched chain portion of a parallel linkage according to an embodiment of the disclosure. As shown in fig. 5, the first branch 03 includes: a first arm 13, a second arm 14, a third arm 15, a second cross-shaped shaft 16 and a fourth arm 17. One end of the first arm 13 is connected with the shaft hole of the second shaft seat 06, and the first arm 13 can rotate on the second shaft seat 06. The other end of the first arm 13 is connected to a second arm 14, and the second arm 14 is rotatable on the first arm 13. The two rotation shafts arranged on the first arm 13 are perpendicular to each other and intersect at one point. The other end of the second arm 14 is rotatably connected with the third arm 15, and the axes of the rotating shafts at the two ends of the second arm 14 are arranged in parallel. The other end of the third arm 15 is connected with a fourth arm 17 through a second cross 16, the axes of the rotating shafts at the two ends of the third arm 15 are vertically arranged, and the fourth arm 17 has the same structure as the first arm 13. The other end of the fourth arm 17 is connected with the shaft hole 11 on the movable platform 02, and the fourth arm 17 can rotate on the movable platform 02.

The second branch 04 has the same structure as the first branch portion 03. One end of the second branched chain 04 is connected with the third shaft seat 07, the other end of the second branched chain 04 is connected with the shaft hole 12 on the movable platform 02, the connection mode is the same as that of the first branched chain part 03, and details are not repeated here.

Referring to fig. 1, the present embodiment provides a parallel mechanism with 2 degrees of freedom in space. The first branched chain portion 03 and the second branched chain portion 04 have no influence on the motion of the movable platform 02, and the two branched chain portions are virtual constraint branched chains and aim to provide a larger load capacity for the movable platform 02. Meanwhile, the number of interactions required by the parallel mechanism for determining movement is 2, and as shown in fig. 1, 3 supporting points for supporting the parallel mechanism, namely a first shaft seat 05, a second shaft seat 06 and a third shaft seat 07, are arranged on a fixed platform 01, and 2 mounting positions of external equipment can be selected from the supporting points. The external device is, for example, a drive motor or a motion sensor. If two branch chain parts are removed, only the first shaft seat 05 can be used for installing a driving motor or a sensor, the installation space is limited, and the realization of motion control of the movable platform 02 is not facilitated.

Fig. 6 is a schematic diagram of an external device installation manner of the parallel mechanism according to the embodiment of the disclosure. As shown in fig. 6, when the movable platform 02 is used as a passive moving member, two members can be selected as active members from the first branched chain portion 03 and the second branched chain portion 04, for example, two driving motors 18 are respectively installed at the second shaft seat 06 and the third shaft seat 07 to respectively drive the first arm 13 of the first branched chain portion 03 to rotate around the second shaft seat 06 and the first arm 13 of the second branched chain portion 04 to rotate around the third shaft seat 07.

Fig. 7 is a schematic view of another external device installation manner of the parallel mechanism according to the embodiment of the disclosure. As shown in fig. 7, two driving motors 18 are respectively installed at the hinge point of the second arm and the third arm in the two branched portions, and drive the third arm 15 in the branched portion to rotate around the second arm 14.

When the movable platform 02 is an active moving component, at least one external device is typically mounted on the first pedestal 05. At this time, the driving motor 18 may be replaced with a motion sensor, that is, a motion output parameter of the movable platform 02 may be detected.

The embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in the embodiments cannot be used in advantageous combination. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the present disclosure, and such alternatives and modifications are intended to be within the scope of the present disclosure.

Claims

1. A parallel mechanism, comprising:

the shaft seat part is arranged on the fixed platform;

the first end of the supporting arm is connected with the shaft seat part;

2. The parallel mechanism of claim 1, wherein the shaft seat comprises:

the first shaft seat is connected with the supporting arm;

3. The parallel mechanism of claim 1, wherein the support arm is an L-shaped structure, the support arm comprising:

the shaft hole is formed in the first end of the supporting arm;

the first cross shaft is in pivot connection with the shaft hole, and the second cross shaft is in pivot connection with the shaft seat.

4. The parallel mechanism of claim 1, wherein the branched chain portion comprises:

the first end of the first arm is coaxially connected with the shaft seat part;

5. The parallel mechanism of claim 2, further comprising: and the external equipment is connected with any two of the first shaft seat, the second shaft seat and the third shaft seat.

6. Parallel mechanism according to claim 5, wherein the external device is a drive motor and/or a motion sensor.

7. The parallel mechanism according to claim 5, wherein when the movable platform is driven passively, the external devices are respectively installed at the second shaft seat and the third shaft seat for driving the branch chain portion to rotate around the second shaft seat or the third shaft seat.

8. The parallel mechanism of claim 5, wherein the drive device is mounted in a position pivotally connected to the branched portion when the movable platform is driven passively.

9. The parallel mechanism of claim 5, wherein at least one of the external devices is mounted at the first hub when the movable platform is actively driven.