Constraint redundant two-rotation two-movement four-freedom-degree parallel mechanismTechnical Field
The utility model relates to an industrial robot field specifically is a four degree of freedom parallel mechanism are removed to two rotations of restraint redundancy.
Background
The parallel mechanism is a space multi-closed-loop mechanism, the fixed platform and the movable platform are connected in parallel by two or more branches, and the position and the posture of the movable platform are changed by driving the branches, so that multi-degree-of-freedom output is realized. Compared with the traditional serial mechanism, the parallel mechanism has the advantages of good integral rigidity, high precision, strong load capacity, good dynamic performance and the like, obtains wide attention and application in the academic and industrial fields, and is used for material carrying and sorting, welding and spraying, curved surface polishing and the like.
In the configuration of the parallel mechanism with less degrees of freedom, the parallel mechanism with three degrees of freedom is mostly adopted, for example, a two-rotation one-movement parallel mechanism with three degrees of freedom (for example, a Z3 parallel spindle head) can form a five-degree-of-freedom series-parallel processing robot by combining two series-connection moving guide rails or two-degree-of-freedom series-connection swing angle heads, and the robot is used for the fields of processing and polishing of aviation structural parts and the like. Compared with a three-degree-of-freedom parallel mechanism, the two-rotation two-movement four-degree-of-freedom parallel mechanism has less related configuration design, can be used in the fields of material handling, part processing and the like, and can also form a five-degree-of-freedom series-parallel processing robot by combining a single-degree-of-freedom moving guide rail. In addition, a constraint redundant two-rotation two-movement four-freedom-degree parallel mechanism can be designed through the configuration, so that the bearing capacity can be improved, and some singular position types can be avoided. Therefore, it is necessary to design a constraint redundant two-rotation two-movement four-freedom parallel mechanism.
SUMMERY OF THE UTILITY MODEL
The utility model aims at overcoming not enough among the above-mentioned background art, provide a restraint redundant two and rotate two and remove four degree of freedom parallel mechanism, this parallel mechanism has precision/rigidity height, operating speed is fast, dynamic property is good, bearing capacity is big advantage.
The utility model provides a technical scheme is:
a constraint redundant two-rotation two-movement four-freedom-degree parallel mechanism is characterized in that: the parallel mechanism comprises a rack, a movable platform, two first branches and two second branches, wherein the two first branches and the two second branches are connected between the rack and the movable platform in parallel;
the first branch comprises a first moving pair, a first spherical hinge, a first connecting rod and a second spherical hinge which are sequentially connected between the rack and the moving platform;
the second branch comprises a second moving pair, a first rotating pair, a second connecting rod and a first hook hinge which are sequentially connected between the rack and the moving platform; in the second branch: and a second rotating shaft axis of the first hook joint connected with the second connecting rod is parallel to the first rotating pair axis and is vertical to the second moving pair moving axis.
The two first branches are arranged symmetrically to the second branches, and the two second branches are arranged symmetrically to the first branches; two second branches: the axes of the first rotating shafts of the two first hooke joints are overlapped; the second rotating shaft axes of the two first hooke joints are parallel to each other.
The first sliding pair comprises a first sliding pair guide rail connected with the rack and a first sliding pair sliding block which is connected with the first spherical hinge and is in sliding fit with the first sliding pair guide rail; the second sliding pair comprises a second sliding pair guide rail connected with the rack and a second sliding pair sliding block connected with the first rotating pair and in sliding fit with the second sliding pair guide rail.
The first moving pair guide rail axis and the second moving pair guide rail axis are both arranged perpendicular to the horizontal plane.
The first moving pair and the second moving pair are driving pairs; and the driving mechanisms of the first moving pair and the second moving pair are ball screw mechanisms driven by a motor.
A constraint redundant two-rotation two-movement four-freedom-degree parallel mechanism is characterized in that: the parallel mechanism comprises a rack, a movable platform, two first branches and two second branches, wherein the two first branches and the two second branches are connected between the rack and the movable platform in parallel;
the first branch comprises a first bearing seat, a second bearing seat, a third hook hinge, a third moving pair and a third spherical hinge which are sequentially connected between the rack and the moving platform; the first rotating shaft of the third hook joint is matched with the first bearing seat and the second bearing seat which are arranged on the rack to form a rotating pair; the third sliding pair sliding block is matched with the third sliding pair connecting rod to form a third sliding pair; a second rotating shaft of the third hook joint is connected with a third moving pair sliding block; the second rotating shaft axis of the third hook joint is vertical to the third moving pair axis;
the second branch comprises a rack revolute pair, a fourth revolute pair and a fourth hooke joint which are sequentially connected between the rack and the movable platform; the frame revolute pair is formed by a third bearing seat and a fourth bearing seat which are arranged on the frame and matched with a rotating shaft connected with a fourth sliding pair sliding block; the fourth sliding pair is formed by a fourth sliding pair sliding block and a fourth sliding pair connecting rod connected with a fourth hook joint in a matched mode; and the second rotating shaft axis of the fourth Hooke hinge connected with the fourth moving pair connecting rod is parallel to the frame rotating pair axis and is vertical to the fourth moving pair axis.
The two first branches are arranged symmetrically to the two second branches; two first branches: the first rotating shaft axes of the two third hook joints connected with the rack are overlapped, and the second rotating shaft axes of the two third hook joints are parallel; the two second branches are arranged symmetrically to the two first branches; two second branches: the first rotating shaft axes of the two fourth hooke joints connected with the movable platform are overlapped, and the second rotating shaft axes of the two fourth hooke joints are parallel.
The third moving auxiliary connecting rod is connected with a third spherical hinge; the fourth sliding pair sliding block is connected with a rotating shaft of a rack rotating pair.
The third moving pair and the fourth moving pair are driving pairs; and the driving mechanisms of the third moving pair and the fourth moving pair are ball screw mechanisms driven by a motor.
The utility model has the advantages that:
the utility model provides a parallel mechanism is a two of restraint redundancy and rotates two and remove four degree of freedom parallel mechanism, has advantages such as rigidity/precision height, dynamic response performance are good, bearing capacity is big, can be used to fields such as burnishing and polishing processing, material letter sorting transport of complicated curved surface.
Drawings
Fig. 1 is a schematic perspective view of a first embodiment of the present invention.
Fig. 2 is a schematic perspective view of the first branch in fig. 1.
Fig. 3 is a schematic perspective view of the second branch in fig. 1.
Fig. 4 is a schematic perspective view of a second embodiment of the present invention.
Fig. 5 is a schematic perspective view of the first branch in fig. 4.
Fig. 6 is a schematic perspective view of the second branch in fig. 4.
Detailed Description
The present invention will be further described with reference to the following embodiments shown in the drawings, but the present invention is not limited to the following embodiments.
Example one
As shown in fig. 1, 2 and 3, a constraint redundant two-rotation two-movement four-degree-of-freedom parallel mechanism comprises a frame (omitted in the figure), amovable platform 1, and two first branches and two second branches connected between the frame and the movable platform in parallel.
The first branch comprises a first movingpair guide rail 11, a first moving pair sliding block 12 (the first moving pair guide rail and the first moving pair sliding block are matched to form a first moving pair), a firstspherical hinge 13, a first connectingrod 14 and a secondspherical hinge 15 which are sequentially connected between the rack and the moving platform; in the first branch: the first spherical hinge is connected between the first connecting rod and the first moving pair, and the second spherical hinge is connected between the first connecting rod and the moving platform.
The second branch comprises a second movingpair guide rail 21, a second moving pair sliding block 22 (the second moving pair guide rail and the second moving pair sliding block are matched to form a second moving pair), a firstrotating pair 23, a second connectingrod 24 and afirst hook joint 25 which are sequentially connected between the rack and the moving platform; in the second branch: and a second rotating shaft axis of the first hook joint connected with the second connecting rod is parallel to the first rotating pair axis and is vertical to the second moving pair moving axis.
The two first branches are arranged symmetrically to the second branches, which are arranged symmetrically to the first branches. Two second branches: the axes of the first rotating shafts of the two first hooke joints are overlapped; the second rotating shaft axes of the two first hooke joints are parallel to each other.
In this embodiment, the first moving pair guide rail and the second moving pair guide rail are both arranged perpendicular to the horizontal plane.
In this embodiment, the driving pair is a moving pair in the first branch and the second branch, and the driving mechanism can be a roller screw (omitted in the figure) driven by a motor; when the driving pair moves, the parallel mechanism can do two-rotation two-movement four-freedom-degree motion. The two rotations are respectively rotation around the axes of the first rotating shafts of the two first hooke joints and rotation around the central connecting line of the two second spherical joints, and the two movements are respectively movement along the direction of the two secondary moving guide rails and movement along the direction vertical to the plane of the two secondary moving guide rails.
Example two
As shown in fig. 4, 5 and 6, a constraint redundant two-rotation two-movement four-degree-of-freedom parallel mechanism comprises a frame (omitted in the figure), amovable platform 1 and two first branches and two second branches connected between the frame and the movable platform in parallel.
The first branch comprises a first bearingseat 31 and a second bearing seat 32 (the rotating axes of the two bearing seats are coaxial), athird hook joint 33, a third movingpair sliding block 34, a third moving pair connecting rod 35 (the third moving pair sliding block and the third moving pair connecting rod are matched to form a third moving pair) and athird ball joint 36 which are sequentially connected between the frame and the moving platform; the first bearing seat and the second bearing seat are arranged on the rack and are matched with the first rotating shaft of the third hook joint to form a rotating pair; the third moving pair sliding block is connected with a second rotatingshaft 37 of a third hook hinge, and the third moving pair connecting rod is connected with a third spherical hinge; and a second rotating shaft axis of the third hook joint (namely the rotating shaft axis of the third hook joint connected with the third moving pair sliding block) is perpendicular to the rotating pair axis and the third moving pair axis.
The second branch comprises a third bearingseat 41 and a fourth bearing seat 42 (the rotating axes of the two bearing seats are coaxial), a fourthsliding pair slider 43, a fourth sliding pair connecting rod 44 (the fourth sliding pair slider and the fourth sliding pair connecting rod are matched to form a second sliding pair) and afourth hooke joint 45 which are sequentially connected between the rack and the moving platform; the third bearing seat and the fourth bearing seat are arranged on the frame, and a rotatingshaft 46 connected with the fourth sliding pair sliding block is matched with the third bearing seat and the fourth bearing seat to form a frame rotating pair; the fourth sliding pair sliding block is connected with arotating shaft 46 of a rack rotating pair; the second rotating shaft axis of the fourth hook joint (namely the rotating shaft axis of the fourth hook joint connected with the fourth moving pair connecting rod) is parallel to the rotating pair axis of the rack and is perpendicular to the fourth moving pair axis.
The two first branches are arranged symmetrically to the two second branches; two first branches: the axes of the first rotating shafts of the two third hooke joints connected with the rack are overlapped; the second rotating shaft axes of the two third Hooke's joints are parallel. The two second branches are arranged symmetrically to the two first branches; two second branches: the axes of the first rotating shafts of the two fourth hooke joints connected with the movable platform are overlapped; the axes of the second rotating shafts of the two fourth hooke joints are parallel to each other.
In this embodiment, the driving pair is a moving pair in the first branch and the second branch, and the driving mechanism can be a roller screw (omitted in the figure) driven by a motor; when the driving pair moves, the parallel mechanism can do two-rotation two-movement four-freedom-degree motion. The two rotations are respectively rotation around the axes of the first rotating shafts of the two fourth Hooke joints and rotation around the central connecting line of the two third spherical joints, and the two movements are respectively movement perpendicular to a plane formed by the central lines of the shaft holes of the four bearing seats and movement along the central connecting line of the two fourth sliding pair sliding blocks.