CN201573206U - A four-degree-of-freedom space parallel mechanism with two movements and two rotations - Google Patents

Abstract

The utility model discloses a four-degree-of-freedom space parallel mechanism with two movements and two rotations, including a static platform, a dynamic platform, and four branches connecting the static platform and the dynamic platform. Rotating pair a, moving pair a and universal hinge a connected in sequence, the second branch includes rotating pair b, moving pair b and universal hinge b sequentially connected from the static platform to the moving platform, the third branch includes Spherical pair a, moving pair c and spherical pair b are sequentially connected from the static platform to the moving platform, and the fourth branch includes spherical pair c, moving pair d and spherical pair d sequentially connected from the static platform to the moving platform. In the parallel mechanism of the utility model, the moving platform has two-dimensional movement and two-dimensional rotation output, and the undesired output motion is constant, the structure is compact, the rigidity is high, and the force characteristic is good. It can be used as a parallel robot, a virtual axis parallel machine tool, and a virtual axis coordinate measurement. Optional models for machine, joystick controls.

Description

A four-degree-of-freedom space parallel mechanism with two movements and two rotations

technical field

The utility model belongs to the technical field of robots and machine tools, in particular to a four-degree-of-freedom space parallel mechanism with two movements and two rotations.

Background technique

The parallel mechanism is composed of a dynamic platform, a static platform and 2-6 branches connecting the two platforms. Compared with the series mechanism, the parallel mechanism has the advantages of high rigidity, strong bearing capacity, high precision, and small self-weight-to-load ratio. Compared with the parallel mechanism with 6 degrees of freedom, the parallel mechanism with few degrees of freedom (less than 6 degrees of freedom) has the characteristics of simple structure, low cost, and relatively simple kinematics solution. Therefore, the parallel mechanism with few degrees of freedom has broad application prospects in industries such as industrial robots, virtual axis CNC parallel machine tools, coordinate measuring machines, motion simulators, and medical robots.

Among the existing four-degree-of-freedom parallel mechanisms, most of them are three-movement-rotation parallel mechanisms, which cannot meet wider application requirements, such as four-degree-of-freedom operations that realize two-dimensional rotation and two-dimensional translation.

Utility model content

The purpose of this utility model is to provide a four-degree-of-freedom space parallel mechanism with two movements and two rotations, which can be used as an optional model for a parallel robot, a virtual axis parallel machine tool, a virtual axis coordinate measuring machine, and a joystick control device. The existing four-degree-of-freedom mechanism with two movements and two rotations is insufficient.

The technical solution adopted by the utility model is a four-degree-of-freedom space parallel mechanism with two movements and two rotations, including a static platform, a dynamic platform and four branches connecting the static platform and the dynamic platform. The rotating joint a, moving joint a and universal hinge a connected in sequence from the static platform to the moving platform, the second branch includes the rotating joint b, moving joint b and universal joint b connected sequentially from the static platform to the moving platform, the first The three branches include spherical pair a, moving pair c and spherical pair b connected sequentially from the static platform to the moving platform, and the fourth branch includes spherical pair c, moving pair d and ball pair connected sequentially from the static platform to the moving platform. Auxiliary d, the axis a of the universal hinge a in the first branch and the axis c of the universal hinge b in the second branch are coaxial, and the first branch and the second branch form a planar circuit.

The utility model is also characterized in that,

The axis b of the universal hinge a in the first branch, the axis d of the universal hinge b in the second branch, the axis of the rotating pair a in the first branch and the rotating pair in the second branch The axes of b are parallel to each other and perpendicular to the planar circuit formed by the first branch and the second branch.

The beneficial effects of the utility model are:

(1) The mechanism has compact structure and high rigidity;

(2) The moving platform in this mechanism has two-dimensional movement and two-dimensional rotation output, and the undesired output motion is constant;

(3) The mechanism has good stress characteristics.

In summary, the technical solution of the utility model has high practical value and broad application prospects, and provides a new model for the technical fields of parallel robots, numerically controlled parallel machine tools, and coordinate measuring machines.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of the utility model having a four-degree-of-freedom space parallel mechanism with two movements and two rotations;

Fig. 2 is a structural schematic diagram of another embodiment of the utility model with a four-degree-of-freedom space parallel mechanism with two movements and two rotations.

In the figure, 1. Static platform, 2. Dynamic platform, 3. Rotating pair a, 4. Moving pair a, 5. Universal hinge a, 6. Rotating pair b, 7. Moving pair b, 8. Universal hinge b , 9. Ball pair a, 10. Moving pair c, 11. Ball pair b, 12. Ball pair c, 13. Moving pair d, 14. Ball pair d, 15. Axis a, 16. Axis b, 17. Axis c, 18. axis d.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The utility model has an embodiment of a four-degree-of-freedom space parallel mechanism with two movements and two rotations. As shown in Figure 1, it includes a static platform 1, a dynamic platform 2 and four branches connecting the static platform 1 and the dynamic platform 2. One branch includes rotating pair a3, moving pair a4 and universal joint a5 connected sequentially from static platform 1 to moving platform 2, and the second branch includes rotating pair b6, moving pair connected sequentially from static platform 1 to moving platform 2 The moving pair b7 and the universal joint b8, the third branch includes the ball pair a9, the moving pair c10 and the ball pair b11 which are sequentially connected from the static platform 1 to the moving platform 2, and the fourth branch includes the connection from the static platform 1 to the moving platform The ball pair c12, the moving pair d13 and the ball pair d14 connected in turn by the platform 2, the first branch and the second branch are set on the same side. Among them, the first branch and the second branch form a planar circuit, the axis a15 of the universal hinge a5 in the first branch is coaxial with the axis c17 of the universal hinge b8 in the second branch, and the first branch The axis b16 of the universal hinge a5 in the branch, the axis d18 of the universal hinge b8 in the second branch, the axis of the rotating pair a3 in the first branch and the axis of the rotating pair b6 in the second branch are parallel to each other And perpendicular to the plane formed by the first branch and the second branch.

The utility model has another embodiment of a four-degree-of-freedom space parallel mechanism with two movements and two rotations, as shown in Figure 2, including a static platform 1, a dynamic platform 2 and four branches connecting the static platform 1 and the dynamic platform 2, The first branch includes the rotating pair a3, the moving pair a4, and the universal hinge a5 that are sequentially connected from the static platform 1 to the moving platform 2, and the second branch includes the rotating pair b6 that is sequentially connected from the static platform 1 to the moving platform 2 , the moving pair b7 and the universal joint b8, the third branch includes the ball pair a9, the moving pair c10 and the ball pair b11 which are sequentially connected from the static platform 1 to the moving platform 2, and the fourth branch includes the connection from the static platform 1 to the moving platform 2 The moving platform 2 is sequentially connected with the ball pair c12, the moving pair d13 and the ball pair d14, and the first branch and the second branch are arranged along the diagonal. Among them, the first branch and the second branch form a planar circuit, the axis a15 of the universal hinge a5 in the first branch is coaxial with the axis c17 of the universal hinge b8 in the second branch, and the first branch The axis b16 of the universal hinge a5 in the branch, the axis d18 of the universal hinge b8 in the second branch, the axis of the rotating pair a3 in the first branch and the axis of the rotating pair b6 in the second branch are parallel to each other And perpendicular to the plane formed by the first branch and the second branch.

The working process of the utility model is to control the input of the moving pair a4, the moving pair b7, the moving pair c10 and the moving pair d13 on the four branches, and the moving platform 2 can realize two moving and two rotating outputs, wherein two moving degrees of freedom The moving platform 2 can move on the plane formed by the first branch and the second branch, and the two degrees of freedom of rotation are in the plane where the moving platform 2 can revolve around the axis a15 and the axis b16 of the universal joint a5 Any straight line turns as the axis of rotation. The moving pair of each branch described in this mechanism is driven by hydraulic pressure, and the tool or operator is installed on the moving platform, which can be used as the end effector of CNC machine tools, robots and measuring machines.

Claims (2)

1. A four-degree-of-freedom space parallel mechanism with two movements and two rotations is characterized in that it comprises a static platform (1), a dynamic platform (2) and four branches connecting the static platform (1) and the dynamic platform (2) , the first branch includes the rotary joint a(3), the moving joint a(4) and the universal joint a(5), which are sequentially connected from the static platform (1) to the moving platform (2), and the second branch includes The rotating pair b(6), moving pair b(7) and universal joint b(8) are connected sequentially from the static platform (1) to the moving platform (2), and the third branch includes from the static platform (1) to The moving platform (2) is sequentially connected to the ball pair a (9), the moving pair c (10) and the ball pair b (11), and the fourth branch includes the sequential connection from the static platform (1) to the moving platform (2). Ball pair c (12), moving pair d (13) and ball pair d (14), the axis a (15) of the universal joint a (5) in the first branch and the second branch The axis c (17) of the universal hinge b (8) is coaxial, and the first branch and the second branch form a planar circuit. 2. The four-degree-of-freedom space parallel mechanism with two movements and two rotations according to claim 1, characterized in that, the axis b (16) of the universal joint a (5) in the first branch, the second The axis d(18) of the universal joint b(8) in the two branches, the axis of the rotating pair a(3) in the first branch and the axis of the rotating pair b(6) in the second branch are parallel to each other And perpendicular to the planar circuit formed by the first branch and the second branch.

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