CN210551185U

CN210551185U - Three-degree-of-freedom 2PRU-PSR parallel mechanism

Info

Publication number: CN210551185U
Application number: CN201920749619.0U
Authority: CN
Inventors: 李秦川; 叶伟; 李翔毅; 胡佳鑫; 张佳恒
Original assignee: Zhejiang Sci Tech University ZSTU
Current assignee: Zhejiang Sci Tech University ZSTU
Priority date: 2019-05-23
Filing date: 2019-05-23
Publication date: 2020-05-19
Anticipated expiration: 2029-05-23

Abstract

The utility model belongs to the technical field of the robot. The three-degree-of-freedom 2PRU-PSR parallel mechanism is high in rigidity precision, good in flexibility and high in processing speed and can be used for processing an aluminum alloy structural member. The technical scheme is as follows: a three-degree-of-freedom 2PRU-PSR parallel mechanism comprises a shell-shaped base, a movable platform with an electric main shaft, and a first branched chain, a second branched chain and a third branched chain which are connected in parallel between the shell-shaped base and the movable platform; the first branched chain and the second branched chain have the same structure and sequentially comprise a moving pair, a rotating pair, a connecting rod and a hook hinge which are connected between the shell-shaped base and the moving platform; in each branched chain, the rotation axis of the revolute pair is vertical to the axis of the revolute pair, and the first rotation axis of the Hooke's joint is parallel to the rotation axis of the revolute pair; in the first branched chain and the second branched chain, the second rotating axes of the two hook joints are coaxial, and the rotating axes of the two rotating pairs are parallel to each other.

Description

Three-degree-of-freedom 2PRU-PSR parallel mechanism

Technical Field

The utility model belongs to the technical field of the robot, concretely relates to can be used for processing novel three degree of freedom 2PRU-PSR parallel mechanism of aluminum alloy structure.

Background

At present, most of traditional industrial robots are in a series structure, the structural form is open loop, the joint control forms are independent and are not coupled, and the industrial robot has the high-quality characteristics of simple structural form, easiness in control, large working space, convenience in solving of positive kinematics and the like. Based on the advantages, the serial robot is put on the market in large quantity and the technology is quite mature. However, the structural form of the open chain of the series robot can also lead the deformation amount among all joint components to be mutually accumulated, so that the rigidity of the whole robot is reduced; meanwhile, error factors such as manufacturing errors, assembly errors and transmission errors among all joint components are also cumulatively increased, and the processing precision of the serial robot is limited. Therefore, under the condition that the machine tool field requires more and more precise part machining, the traditional serial robot cannot be adequate for the machining task. In order to break through the technical bottleneck, the parallel robot becomes a key focus topic of researchers and researchers in domestic and foreign countries. In particular, parallel mechanisms with less degrees of freedom are increasingly paid attention and favored by researchers with the research on parallel mechanisms and the continuous development of parallel mechanics. Compared with a fully parallel six-degree-of-freedom mechanism, the less-degree-of-freedom parallel mechanism has the advantages of simple kinematics, weak coupling, easiness in modularization and the like, and some less-degree-of-freedom parallel mechanisms are successfully applied in the industrial field.

The utility model discloses a patent (like CN 101066593A, CN 106903677A, CN 107175654A) of current parallel mechanism utility model, the inside hinge number of mechanism is too much, influences the machining precision, and the structure is complicated, and production and processing are difficult. Therefore, it is necessary to provide a parallel mechanism with less degrees of freedom, which has good processability and is easy to produce and process.

SUMMERY OF THE UTILITY MODEL

The utility model overcomes not enough among the above-mentioned background art, provided a three degree of freedom 2PRU-PSR parallel mechanism that rigidity precision that can be used for processing aluminum alloy structure is high, the flexibility is good, the process velocity is fast.

The utility model provides a technical scheme is:

a three-degree-of-freedom 2PRU-PSR parallel mechanism comprises a shell-shaped base, a movable platform with an electric main shaft, and a first branched chain, a second branched chain and a third branched chain which are connected in parallel between the shell-shaped base and the movable platform;

the first branched chain and the second branched chain have the same structure and sequentially comprise a moving pair, a rotating pair, a connecting rod and a hook hinge which are connected between the shell-shaped base and the moving platform; in each branched chain, the rotation axis of the revolute pair is vertical to the axis of the revolute pair, and the first rotation axis of the Hooke's joint is parallel to the rotation axis of the revolute pair; in the first branched chain and the second branched chain, the second rotating axes of the two hook joints are coaxial, and the rotating axes of the two rotating pairs are parallel to each other;

the third branched chain comprises a third moving pair, a third spherical hinge, a third connecting rod and a third rotating pair which are connected with the mounting base and the moving platform in sequence.

And the rotation axis of a third revolute pair in the third branched chain is parallel to the second rotation axis of two Hooke joints in the first branched chain and the second branched chain.

The first rotating pair axis is vertical and intersected with the first guide rod axis of the first moving pair, and the second rotating pair axis is vertical and intersected with the second guide rod axis of the second moving pair.

The axes of the moving pairs in the three branched chains are parallel to each other.

The moving pairs in the three branched chains are all driving pairs; the input drive is realized by driving a ball screw to drive a sliding pair by a servo motor.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model provides a parallel mechanism can carry out two rotations of space one and remove the motion, has advantages such as rigidity precision is high, the flexibility is good, the process velocity is fast, workspace is big, the kinematics is simple relatively, control is easy.

Drawings

Fig. 1 is a schematic diagram of a PRS-PRU-PUR parallel mechanism according to an embodiment of the present invention.

Fig. 2 is a schematic perspective view of the first branched chain in the parallel mechanism shown in fig. 1.

Fig. 3 is a schematic perspective view of a second branched chain in the parallel mechanism shown in fig. 1.

Fig. 4 is a schematic perspective view of a third branched chain in the parallel mechanism shown in fig. 1.

The figure shows that: 1. the device comprises a first branch chain, a second branch chain, a third branch chain, a shell-shaped base, a 5, an electric spindle, a 6, a movable platform, 11, a first sliding block, 12, a first connecting rod, 13, a first moving pair, 14, a first rotating pair, 15, a first Hooke hinge, 151, a first rotating shaft of the first Hooke hinge, 152, a second rotating shaft of the first Hooke hinge, 21, a second sliding block, 22, a second connecting rod, 23, a second moving pair, 24, a second rotating pair, 25, a second Hooke hinge, 251, a first rotating shaft of the second Hooke hinge, 252, a second rotating shaft of the second Hooke hinge, 31, a third sliding block, 32, a third connecting rod, 33, a third moving pair, 34, a third spherical hinge, 35 and a third rotating pair.

Detailed Description

The invention will be further explained with reference to the following embodiments shown in the drawings.

The three-degree-of-freedom 2PRU-PSR parallel mechanism shown in fig. 1 (where P denotes a kinematic pair, R denotes a revolute pair, U denotes a hooke joint, S denotes a spherical joint, and P denotes that the kinematic pair is an active driving pair) includes: a shell-shaped base 4 (in the figure, the shell-shaped base is simplified into three rod-shaped bases which are connected into a whole for convenience of display), a movable platform 6 with an electric spindle 5, and a first branched chain 1, a second branched chain 2 and a third branched chain 3 which are connected between the shell-shaped base 4 and the movable platform 6; one movement and two rotations of the movable platform can be realized through input drive in the three branched chains, and the axes of guide rods of the moving pairs of the three branched chains are parallel to each other.

As shown in fig. 1, 2 and 3, the first branched chain 1 and the second branched chain 2 have the same structure and are symmetrically distributed in spatial position, and respectively include a first slider 11 and a second slider 21 having the same structure, a first link 12 and a second link 22 having the same structure, and a kinematic pair having the same structure. Three kinematic pairs are arranged on each branched chain; 3 kinematic pairs of the first branched chain, one is a first kinematic pair 13 (including a first guide rod fixed on the shell-shaped base and a first sliding block 11 in sliding fit with the first guide rod) connected between the shell-shaped base 4 and a first rotating pair 14, one is a first rotating pair connected between the first sliding block 11 and a first connecting rod 12, and one is a first hooke hinge 15 connected between the first connecting rod 12 and the movable platform 6, and the branched chain is called as a PRU branched chain; the rotation axis of the first rotating pair 14 is vertical to the axis of the first moving pair 13; the first rotation axis 151 of the first hooke joint 15 is parallel to the rotation axis of the first revolute pair 14. 3 kinematic pairs of a second branched chain, one is a second moving pair 23 (comprising a second guide rod fixed on the shell-shaped base and a second sliding block 21 in sliding fit with the second guide rod) connected between the shell-shaped base and a second revolute pair 24, one is a second revolute pair connected between the second sliding block and a second connecting rod 22, and one is a second hooke joint 25 connected between the second connecting rod and the movable platform, and the branched chain is also called as a PRU branched chain; the rotation axis of the second rotation pair is vertical to the axis of the second moving pair; the first rotation axis 251 of the second hook joint is parallel to the rotation axis of the second revolute pair; in the two PRU branched chains, the second rotation axis 152 of the first hooke joint and the second rotation axis 252 of the second hooke joint are coaxial, and the rotation axes of the two revolute pairs (the first revolute pair and the second revolute pair) are parallel to each other.

Preferably, the rotation axis of the first rotating pair is perpendicular to and intersects with the first guide rod axis of the first moving pair, and the rotation axis of the second rotating pair is perpendicular to and intersects with the second guide rod axis of the second moving pair.

The third branched chain 3 shown in fig. 4 sequentially comprises three kinematic pairs connected to the mounting base 4 and the movable platform 6, a third kinematic pair 33 connected between the shell-shaped base 4 and a third spherical hinge 34 (comprising a third guide rod fixed on the shell-shaped base and a first slide block 31 in sliding fit with the guide rod), a third spherical hinge 34 connected between the third slide block 31 and a third connecting rod 32, and a third revolute pair 35 connected between the third connecting rod 32 and the movable platform 6, and the branched chain is called a PSR branched chain; the rotation axis of the third revolute pair 35 is parallel to the second rotation axes of two hooke joints in the first and second branched chains (i.e. the second rotation axis 152 of the first hooke joint and the second rotation axis 252 of the second hooke joint).

In the utility model, the three moving pairs are active driving pairs, and the ball screw mechanism is driven by the servo motor to realize input driving; when the moving pair moves, the three-degree-of-freedom motion effect that the moving platform 6 in the parallel mechanism rotates and moves in space can be realized.

Claims

1. A three-degree-of-freedom 2PRU-PSR parallel mechanism comprises a shell-shaped base (4), a movable platform (6) with an electric main shaft (5), and a first branched chain (1), a second branched chain (2) and a third branched chain (3) which are connected in parallel between the shell-shaped base and the movable platform;

the third branched chain comprises a third moving pair (33), a third spherical hinge (34), a third connecting rod (32) and a third rotating pair (35) which are connected with the mounting base and the moving platform in sequence.

2. The three degree of freedom 2PRU-PSR parallel mechanism of claim 1, wherein: and the rotating axis of a third rotating pair in the third branched chain is parallel to the second rotating shafts of two hooke joints in the first branched chain and the second branched chain.

3. The three degree of freedom 2PRU-PSR parallel mechanism of claim 2, wherein: the rotating axis of the first rotating pair is vertical to and intersected with the first guide rod axis of the first moving pair, and the rotating axis of the second rotating pair is vertical to and intersected with the second guide rod axis of the second moving pair.

4. The three degree of freedom 2PRU-PSR parallel mechanism of claim 3, wherein: the axes of the moving pairs in the three branched chains are parallel to each other.

5. The three degree of freedom 2PRU-PSR parallel mechanism of claim 4, wherein: the moving pairs in the three branched chains are all active driving pairs; the input drive is realized by driving a ball screw to drive a sliding pair by a servo motor.