CN114310849A - Two-rotation two-movement parallel mechanism - Google Patents

Abstract

The present application belongs to the technical field of mechanical components, and in particular relates to a parallel mechanism with two transfers and two transfers. It includes a branch chain mechanism and a connecting mechanism that are connected to each other. The connecting mechanism includes a fixed base, a support arm connecting plate and a moving platform arranged in sequence. The branch chain mechanism includes a first branch chain, a second branch chain, and a third branch chain. chain and a fourth branch chain; one end of the first branch chain is connected with the fixed base, the other end of the first branch chain is connected with the motion platform, and the first branch chain is connected with the support arm connecting plate One end of the second branch chain is connected to the fixed base, the other end of the second branch chain is connected to the support arm connecting plate, and one end of the third branch chain is connected to the fixed base, so The other end of the third branch chain is connected to the motion platform, one end of the fourth branch chain is connected to the fixed base, and the other end of the fourth branch chain is connected to the motion platform. It can realize forward and horizontal movement and horizontal and vertical swing.

Description

A two-turn and two-shift parallel mechanism

technical field

The present application belongs to the technical field of mechanical components, and in particular relates to a parallel mechanism with two transfers and two transfers.

Background technique

The parallel mechanism is a closed-loop mechanism in which the movable platform and the fixed platform are connected by at least two independent kinematic chains, the mechanism has two or more degrees of freedom, and is driven in parallel.

In recent years, with the continuous deepening of related theoretical research on parallel mechanisms and the continuous expansion of application fields, parallel mechanisms with few degrees of freedom have become a research hotspot in this field. The parallel mechanism with few degrees of freedom has the advantages of high precision, high speed, high rigidity, and small cumulative position error. In the fields of mechanical processing, medical devices, space technology, sensors, etc., more and more attention is paid by the industry and academia, and most of the researches are aimed at Among them, R stands for rotating pair and T stands for parallel mechanism with moving pair motion. There are few relevant literatures on the design and analysis of parallel mechanism with 2R2T motion. However, 2R2T parallel mechanism vibrates in 4-axis parallel machine tools, agriculture and mining industries. Screening, ankle rehabilitation and other medical fields have potential applications.

SUMMARY OF THE INVENTION

1. Technical problems to be solved

There are few relevant literatures based on the current design and analysis of parallel mechanisms with 2R2T motion. However, 2R2T parallel mechanisms have potential applications in 4-axis parallel machine tools, shakers in agriculture and mining, ankle rehabilitation, and other medical fields. The present application provides a parallel mechanism with two transfers and two transfers.

2. Technical solutions

In order to achieve the above purpose, the present application provides a parallel mechanism with two transfers and two shifts, including a branch chain mechanism and a connecting mechanism that are connected to each other. The branched chain mechanism includes a first branched chain, a second branched chain, a third branched chain and a fourth branched chain; one end of the first branched chain is connected to the fixed base, and the other end of the first branched chain is connected to the fixed base. The motion platform is connected, the first branch chain is connected with the support arm connecting plate, one end of the second branch chain is connected with the fixed base, and the other end of the second branch chain is connected with the support arm board connection, one end of the third branch chain is connected to the fixed base, the other end of the third branch chain is connected to the motion platform, one end of the fourth branch chain is connected to the fixed base, the The other end of the fourth branch chain is connected with the motion platform.

Another embodiment provided by the present application is: the first branch chain and the fixed base are connected at a first connection point, the third branch chain and the fixed base are connected at a second connection point, so The fourth branch chain and the fixed base are connected to a third connection point, and the first connection point, the second connection point and the third connection point are three vertices of an isosceles right triangle.

Another embodiment provided in this application is: the first branch chain is connected to the motion platform at a fourth connection point, the third branch chain is connected to the motion platform at a fifth connection point, and the first branch chain is connected to the motion platform at a fifth connection point. The four-branched chain is connected to the motion platform at a sixth connection point, and the fourth connection point, the fifth connection point and the sixth connection point are three vertices of an isosceles right triangle.

Another embodiment provided by the present application is: the first branch chain is connected to the fixed base through a first rotating joint assembly, and the first branch chain is connected to the motion platform through a first universal joint assembly .

Another embodiment provided by the present application is: the second branch chain is connected to the fixed base through a second rotating joint assembly, and the second branch chain is connected to the support arm connecting plate through a third rotating joint assembly connect.

Another embodiment provided by the present application is: the third branch chain is connected to the fixed base through a second universal joint assembly, and the third branch chain is connected to the motion platform through a first ball joint assembly .

Another embodiment provided by the present application is: the fourth branch chain is connected to the fixed base through a third universal joint assembly, and the fourth branch chain is connected to the motion platform through a second ball joint assembly .

Another embodiment provided by the present application is: the first branch chain includes a smooth bar, an end cover, a light shaft seat and a reduction box assembly connected in sequence, the reduction box assembly is connected with the servo motor, and the light bar is connected with The first universal joint assembly is connected, and the reduction box assembly is connected with the first rotary joint assembly.

Another embodiment provided by the present application is: the smooth rod, the positioning ring, the nut, and the lead screw are sequentially connected with the reduction box assembly, the positioning ring is arranged on the outside of the smooth rod, and the nut is arranged on the outside of the screw.

Another embodiment provided by the present application is that: the light bar, the light shaft seat and the reduction box assembly form a moving pair.

3. Beneficial effects

Compared with the prior art, the beneficial effects of the two-transfer and two-shift parallel mechanism provided by the present application are:

The two-transition and two-shift parallel mechanism provided by the present application is a novel parallel mechanism that can realize two-dimensional rotation and two-dimensional translation.

The two-shift, two-shift parallel mechanism provided by this application abandons the configuration of the traditional parallel mechanism in which all the branches are directly connected to the motion platform, and adopts some branches to be connected to other branches to form a closed loop, so that the branches in the closed loop can move. Decoupling, so that the mechanism evolves from a strongly coupled configuration to a weakly coupled two-dimensional rotation and two-dimensional translation mechanism.

The two-transfer, two-shift parallel mechanism provided by the present application can realize forward and horizontal movement and horizontal and vertical swing, and the main branch and the short branch form a closed-loop structure, which can make the short branch and the moving platform move in the forward direction. The motion is decoupled, so that the mechanism becomes a weakly coupled two-transition and two-shift parallel mechanism.

Description of drawings

Fig. 1 is the two-transfer two-shift parallel mechanism structure schematic diagram of the present application;

Fig. 2 is the first partial structural schematic diagram of the two-transfer, two-shift parallel mechanism structure of the present application;

3 is a schematic structural diagram of the first universal joint assembly of the present application;

4 is a schematic structural diagram of the first rotary joint assembly of the present application;

5 is a schematic diagram of the partial structure of the first branch of the present application;

6 is a second partial structural schematic diagram of the two-transfer, two-shift parallel mechanism structure of the present application;

Fig. 7 is the third partial structural schematic diagram of the two-transfer, two-shift parallel mechanism structure of the present application;

8 is a schematic diagram of the fourth part of the two-transfer, two-shift parallel mechanism structure of the present application;

FIG. 9 is a schematic structural diagram of the second universal joint assembly of the present application.

Detailed ways

Hereinafter, specific embodiments of the present application will be described in detail with reference to the accompanying drawings, from which those skilled in the art can clearly understand the present application and be able to implement the present application. Without departing from the principles of the present application, the features of the various embodiments may be combined to obtain new embodiments, or instead of certain features of certain embodiments, to obtain other preferred embodiments.

1 to 9, the present application provides a parallel mechanism with two transfers and two shifts, including a branch chain mechanism and a connecting mechanism that are connected to each other, and the connecting mechanism includes a fixed base 1, a support arm connecting plate 3 and a motion platform arranged in sequence. 2. The branched chain mechanism includes a first branched chain, a second branched chain, a third branched chain and a fourth branched chain; one end of the first branched chain is connected to the fixed base 1, and the first branched chain The other end is connected to the motion platform 2, the first branch is connected to the support arm connecting plate 3, one end of the second branch is connected to the fixed base 1, and the other end of the second branch is connected Connected with the arm connecting plate 3, one end of the third branch is connected to the fixed base 1, the other end of the third branch is connected to the motion platform 2, and one end of the fourth branch is connected to the fixed base 1. The fixed base 1 is connected, and the other end of the fourth branch chain is connected with the moving platform 2 .

Further, the first branch is connected to the fixed base 1 at a first connection point, the third branch is connected to the fixed base 1 at a second connection point, and the fourth branch is connected to The fixed base 1 is connected to a third connection point, and the first connection point, the second connection point and the third connection point are the three vertices of an isosceles right triangle; The motion platform 2 is connected to the fourth connection point, the third branch chain and the motion platform 2 are connected to the fifth connection point, the fourth branch chain and the motion platform 2 are connected to the sixth connection point, The fourth connection point, the fifth connection point and the sixth connection point are three vertices of an isosceles right triangle.

Further, the first branch chain is connected to the fixed base 1 through a first rotating joint assembly 81 , and the first branch chain is connected to the motion platform 2 through a first universal joint assembly 11 . The second branch chain is connected to the fixed base 1 through a second rotating joint assembly 83 , and the second branch chain is connected to the support arm connecting plate 3 through a third rotating joint assembly 84 . The third branch chain is connected to the fixed base through the second universal joint assembly 101 , and the third branch chain is connected to the motion platform 2 through the first ball joint assembly 91 . The fourth branch chain is connected to the fixed base 1 through the third universal joint assembly 102 , and the fourth branch chain is connected to the motion platform 2 through the second ball joint assembly 92 . The third branch chain, the fourth branch chain and the joint components connecting both ends form an unconstrained UPS branch chain, the first branch chain and the joint components at both ends form a 2R2T less-constrained branch chain, and the constraint type determines the entire parallel mechanism. The degree of freedom type, the second branch connects the two on the first branch to form a closed loop to achieve movement decoupling.

Specifically, the structures of the first branch chain, the second branch chain, the third branch chain and the fourth branch chain here are the same, that is, the connection relationship between their constituent parts and the parts is the same, but for the sake of distinction, the first branch chain here The branch is the main branch 4 , the second branch is the short branch 5 , the third branch is the first sub-branch 6 , and the fourth branch is the second sub-branch 7 . The beginning of the main branch chain 4 is connected to the intersection of the base of the isosceles right triangle and the high line of the fixed base 1 through the first rotating joint assembly 81, and the end is connected to the apex of the moving platform 2 through the first universal joint assembly 11; The short branch chain 5 is located directly below the main branch chain 4, the beginning end is connected to the lower end of the equilateral triangle of the fixed base 1 through the second rotating joint assembly 83, and the end is connected to the arm connecting plate 3 through the third rotating joint assembly 84. Connection, the arm connecting plate 3 is connected to the end cover 48 of the optical axis seat of the main branch chain 4; The upper end point of the equilateral triangle of the fixed base 1, the end is connected to the upper end point of the motion platform 2 through the first ball joint assembly 91; The joint assembly 10 is connected to the vertex of the equilateral triangle of the fixed base 1 , and the end is connected to the right end of the motion platform 2 through the second ball joint assembly 92 .

Further, the first branch chain includes a light bar 47, an end cover 48, a light shaft seat 42 and a reduction box assembly 43 connected in sequence, the reduction box assembly 43 is connected with the servo motor 41, and the light bar 47 is connected with all The first universal joint assembly 11 is connected, and the reduction box assembly 43 is connected with the first rotary joint assembly 81 . The smooth rod 47 , the positioning ring 46 , the nut 45 , and the lead screw 44 are sequentially connected to the reduction box assembly 43 , the positioning ring 46 is arranged on the outside of the smooth rod 47 , and the nut 45 is set on the lead screw 44 outside.

Specifically, the servo motor 41 is fixed on the end cover 432 of the reduction box by screws, the output shaft of the servo motor 41 is fixedly connected with the small wheel 434, the small wheel 434 forms a belt transmission with the large wheel 433 through the belt 435, and the large wheel 433 and the wheel shaft 436 The bearing seat 438 is fixed between the gearbox end cover 432 and the optical axis seat 42 through screws, and is sleeved outside the wheel shaft 436, and the bearing seat 438 and the wheel shaft 436 are installed between the bearing 437 and the wheel shaft 436. , the bearing 437 and the bearing seat 438 are coaxial, and the axial movement of the bearing 437 is restricted by the bearing seat nut 439 at one end of the bearing seat 438 to be fixed; the lead screw 44 is fixedly connected with the axle 436 through the screw, The two are concentric, and the lead screw covers the nut 45, and realizes the fixed connection between the nut 45 and the polished rod 47 through the positioning ring 46; the end cover 48 is sleeved on the outside of the polished rod 47 and fixed on one end of the optical axis seat 42 by screws, so that the The optical axis seat 42 seals the inner positioning ring 46, the nut 45 and the lead screw 44, so that the optical axis 47 forms a moving pair with the optical axis seat 42 and the reduction box assembly 43; the reduction box shell 431 is connected with the screw through screws. The end cover 432 of the reduction box is fixedly connected to encapsulate the large wheel 433, the small wheel 434, the belt 435 and the axle 436; the reduction box shell 431 is connected to the bottom edge of the equilateral triangle of the fixed base 1 and the high line through the rotating joint assembly 81. intersection.

The first rotating joint assembly 81 is composed of a double-ear seat 811, a single-ear seat 812, and a short shaft 813. The double-ear seat 811 is fixed on the intersection of the base of the equilateral triangle and the high line of the fixed base 1 by screws. The single-ear seat 812 is fixed on the reduction box housing 431 by screws; the short shaft 813 is connected by a snap spring to form a rotating joint. The first universal joint assembly 11 is composed of a shaft end coupling 111, a shaft end coupling 112, a cross shaft 113 of the main branch chain 1, and a first universal joint connecting piece 114. The shaft end coupling 111 and the light bar 47 Fixed connection, the main branch chain 1 universal joint connector 114 is fixed on the vertex of the motion platform by screws, the shaft end coupling 112 and the main branch chain 1 universal joint connector 114 are fixed by screws, the shaft end coupling 111, The shaft end coupling 112 is connected by the cross shaft 113 of the main branch chain 1 to form a universal joint.

The second rotating joint assembly 83 is the same as the first rotating joint assembly, except that the double ear seat is fixed to the lower end point of the equilateral triangle of the fixed base 1 by screws.

The third rotating joint assembly 84 is the same as the first rotating joint assembly, except that the double-ear seat is fixed under the support arm connecting plate 3 by screws, and the single-ear seat is on the fixed light bar.

The first ball joint assembly 91 is composed of a ball seat 911 and a ball head 912 . The ball seat 911 is connected with the smooth bar through threads, and the ball head 912 is fixed on the vertex of the motion platform 2 . The second ball joint assembly 92 has the same structure as the first ball joint assembly 91, and the related connection relationship is also the same.

The second universal joint assembly 101 is composed of a universal joint double lug seat 1011, a universal joint single lug seat 1012, and a cross shaft 1013. The second universal joint double lug seat 1011 is fixed on the equilateral triangle of the fixed base 1 by screws At the end point, the single lug seat 1012 of the universal joint is fixed on the casing of the reduction gearbox by screws, and the two are connected by the cross shaft 1013 to form a universal joint.

The third universal joint assembly 102 is the same as the second universal joint assembly, except that the double lug seat of the universal joint is fixed to the vertex of the equilateral triangle of the fixed base 1 by screws.

The short axis 813 of the main branch chain 4 and the short axis of the short branch chain 5 are parallel to each other and are parallel to the high line of the isosceles right triangle of the fixed base 1; The axis of the through hole of the double lug seat of the three-cardan joint assembly is always collinear with the stub shaft 813 , and the axis of the through hole of the shaft end coupling 111 on the main branch 4 is always perpendicular to the stub shaft 813 .

The two-transfer, two-transfer parallel mechanism of the present application is applied to vibrating screens in agriculture and mining, ankle rehabilitation and other medical fields.

Although the present application has been described above with reference to specific embodiments, it will be understood by those skilled in the art that many modifications may be made in configuration and detail disclosed herein within the spirit and scope of the present disclosure. The scope of protection of the present application is to be determined by the appended claims, and the claims are intended to cover all modifications encompassed by the literal meaning or scope of equivalents to the technical features in the claims.

Claims (10)

1. A two-rotation two-movement parallel mechanism is characterized in that: the device comprises a branched chain mechanism and a connecting mechanism which are connected with each other, wherein the connecting mechanism comprises a fixed base, a support arm connecting plate and a moving platform which are sequentially arranged, and the branched chain mechanism comprises a first branched chain, a second branched chain, a third branched chain and a fourth branched chain;

the movable support is characterized in that one end of the first branched chain is connected with the fixed base, the other end of the first branched chain is connected with the movable platform, the first branched chain is connected with the support arm connecting plate, one end of the second branched chain is connected with the fixed base, the other end of the second branched chain is connected with the support arm connecting plate, one end of the third branched chain is connected with the fixed base, the other end of the third branched chain is connected with the movable platform, one end of the fourth branched chain is connected with the fixed base, and the other end of the fourth branched chain is connected with the movable platform.

2. The two-turn two-shift parallel mechanism of claim 1, wherein: the first branched chain and the fixed base are connected to a first connection point, the third branched chain and the fixed base are connected to a second connection point, the fourth branched chain and the fixed base are connected to a third connection point, and the first connection point, the second connection point and the third connection point are three vertexes of an isosceles right triangle.

3. The two-turn two-shift parallel mechanism of claim 2, wherein: the first branched chain and the moving platform are connected to a fourth connecting point, the third branched chain and the moving platform are connected to a fifth connecting point, the fourth branched chain and the moving platform are connected to a sixth connecting point, and the fourth connecting point, the fifth connecting point and the sixth connecting point are three vertexes of an isosceles right triangle.

4. The two-rotation two-shift parallel mechanism according to any one of claims 1 to 3, wherein: the first branch chain is connected with the fixed base through a first rotating joint component, and the first branch chain is connected with the moving platform through a first universal joint component.

5. The two-turn two-shift parallel mechanism of claim 4, wherein: the second branched chain is connected with the fixed base through a second rotating joint component, and the second branched chain is connected with the support arm connecting plate through a third rotating joint component.

6. The two-turn two-shift parallel mechanism of claim 4, wherein: the third branched chain is connected with the fixed base through a second universal joint assembly, and the third branched chain is connected with the motion platform through a first ball joint assembly.

7. The two-turn two-shift parallel mechanism of claim 4, wherein: the fourth branched chain is connected with the fixed base through a third universal joint assembly, and the fourth branched chain is connected with the motion platform through a second ball joint assembly.

8. The two-turn two-shift parallel mechanism of claim 4, wherein: the first supporting chain comprises a light bar, an end cover, a light shaft seat and a reduction gearbox assembly which are sequentially connected, the reduction gearbox assembly is connected with the servo motor, the light bar is connected with the first universal joint assembly, and the reduction gearbox assembly is connected with the first rotating joint assembly.

9. The two-turn two-shift parallel mechanism of claim 8, wherein: the feed rod, the locating ring, the nut and the screw rod are sequentially connected with the reduction gearbox assembly, the locating ring is arranged on the outer side of the feed rod, and the nut is arranged on the outer side of the screw rod.

10. The two-turn two-shift parallel mechanism of claim 9, wherein: the polished rod, the optical axis seat and the reduction gearbox component form a moving pair.

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