CN103286777B - A kind of Novel spatial three-freedom-degreeparallel parallel connection mechanism - Google Patents

Abstract

The invention discloses a novel space three-degree-of-freedom parallel mechanism, which includes a frame, and a moving platform is arranged above the frame, and the frame is symmetrically arranged in an equilateral triangle. Each triangular side is provided with a guide rail, and the first, second, and third active branch chain spaces are three-symmetrically distributed between the frame and the moving platform. The first, second, and third The three active branch chains have the same structure, and each active branch chain includes a sliding saddle that is connected with a guide slide rail to form a linear movement pair. A hinge with rotational degrees of freedom is connected to the moving platform. The parallel mechanism of the present invention has simple structure, is convenient to manufacture and install, has strong attitude capability and good dynamic performance.

Description

A new type of parallel mechanism with three degrees of freedom in space

technical field

The invention relates to a parallel mechanism, in particular to a parallel mechanism capable of realizing three-rotation operation in space.

Background technique

According to patents ZL200910054381, ZL201210182195.7, etc., the existing three-degree-of-freedom parallel mechanism in space mainly has two realization forms: first, two (or three) unconstrained motion branch chains and A three-degree-of-freedom just-constrained branch chain is connected, and driving devices are installed on the branch chains. Each branch chain can move independently under the drive of the driving device, so that the moving platform generates three rotations in space relative to the frame; One-degree parallel mechanism and one-degree-of-freedom rotor connected in series.

The shortcomings of this type of mechanism are: the structure of each branch chain is complex, the arrangement of the kinematic pairs in the branch chain is difficult, the requirements for processing and assembly are harsh, the manufacturing cost is high, the inertia of the end effector is large, and the unconstrained branch chain and precise The loads of the constrained branch chains vary greatly, which affects the dynamic performance of the mechanism.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a novel space three-degree-of-freedom parallel mechanism with simple structure, convenient installation, high bearing capacity and large working space, which can realize three rotations of the end effector space.

A novel space three-degree-of-freedom parallel mechanism of the present invention comprises a frame, a moving platform is arranged above the frame, and the frame is symmetrically arranged in an equilateral triangle. Each triangular side is provided with a guide rail, and the first, second, and third active branch chains are space-symmetrically distributed between the frame and the moving platform. The first, second, and third active The branch chains have the same structure, and each active branch chain includes a sliding saddle that is connected with the guide slide rail to form a linear movement pair. The directions of the corresponding guide rails are the same, and the other end of the connecting rod is connected with the moving platform through a hinge with three rotational degrees of freedom.

A novel space three-degree-of-freedom parallel mechanism of the present invention comprises a frame, a moving platform is arranged above the frame, and the frame is symmetrically arranged in an equilateral triangle. Each triangular side is provided with a guide rail, and the first, second, and third active branch chains are space-symmetrically distributed between the frame and the moving platform. The first, second, and third active The branch chains have the same structure. Each active branch chain includes a sliding saddle connected with a guide slide rail to form a linear movement pair. A sliding rail is fixedly connected to the sliding saddle. One end of the connecting rod is a slider. The slider and the slide rail are slidably connected to form the first moving pair, the moving axis of the slider is in line with the axis of the connecting rod, and the other end of the connecting rod is connected with the moving platform through a hinge with three rotational degrees of freedom.

The beneficial effects of the space three-degree-of-freedom parallel mechanism of the present invention are: modular structure design, simple structure, easy manufacture and installation, strong posture capability and good dynamic performance. When the driving device drives the first, second and third active branch chains to produce the same movement, the moving platform realizes the coupling movement of rotation and translation perpendicular to the normal direction of the moving platform. When the driving device drives the three active branch chains to produce different When input, the moving platform can realize the rotation around the other two directions.

Description of drawings

Fig. 1 is a structural representation of a novel space three-degree-of-freedom parallel mechanism of the present invention;

Fig. 2 is a schematic diagram of the working structure of the parallel mechanism shown in Fig. 1;

Fig. 3 is a partial schematic diagram of the driving device in the working structure of the parallel mechanism shown in Fig. 2 .

Detailed ways

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

As shown in the figure, a new type of space three-degree-of-freedom parallel mechanism of the present invention includes a frame 7, a moving platform 1 is arranged above the frame, and the frame is arranged symmetrically in an equilateral triangle. Each triangular side of the frame is provided with a guide rail, and the first, second, and third active branch chains are spatially symmetrical, that is, they are spatially symmetrically distributed between the frame and the moving platform. , the first, second, and third active branch chains have the same structure, and each active branch chain includes a sliding saddle connected with a guide rail to form a linear movement pair, and the sliding saddle is movably connected with one end of the connecting rod , the other end of the connecting rod is connected with the moving platform through a hinge with three rotational degrees of freedom.

Preferably, the saddle is connected to one end of the connecting rod through a turning pair, and the axis of the turning pair is in the same direction as the guide rail corresponding to the turning pair. Of course, a slide rail can also be fixedly connected to the saddle, and one end of the connecting rod is a slide block, and the slide block is slidably connected with the slide rail to form the first moving pair, and the moving axis of the slide block is collinear with the axis of the connecting rod. , the three-dimensional rotation of the end effector can also be realized.

Preferably, the hinge with three rotational degrees of freedom is a ball hinge.

The present invention is described in detail below again in conjunction with each figure:

In Fig. 1, the frame 7 is arranged symmetrically in an equilateral triangle, and the first active branch chain, the second active branch chain, and the third active branch chain are spatially symmetrically distributed between the frame 7 and the moving platform 1, so that The frame 7 is connected with the first active branch chain, the second active branch chain and the third active branch chain through a linear movement pair. The linear moving pair can adopt the guide rail slider structure shown in the accompanying drawings, that is, the guide rail is fixedly connected to the frame 7, and one end of the active branch chain is provided with a saddle, and the guide rail cooperates with the saddle to form a linear movement. vice. The linear moving pair can adopt the forms of linear motor, screw nut structure and the like.

The first active branch chain, the second active branch chain, and the third active branch chain have the same mechanical structure, and are all composed of a sliding saddle, a rotating pair, a connecting rod, and a ball hinge. The ball hinge can also adopt other hinge forms with three rotation capabilities, such as a hinge composed of three two-by-two orthogonal rotation pairs.

The first active branch chain is composed of a first sliding saddle 6A, a first rotating pair 5A, a first connecting rod 4A, and a first ball hinge 3A. The first saddle 6A and the frame guide rail constitute a linear movement pair, the first saddle 6A is connected to one end of the first connecting rod 4A through the first rotation pair 5A, and the axis of the first rotation pair 5A is in the same direction as the corresponding linear movement pair , the other end of the first connecting rod 4A is connected with the moving platform 1 through the first ball joint 3A.

The second active branch chain is composed of a second sliding saddle 6B, a second rotating pair 5B, a second connecting rod 4B, and a second ball hinge. The second sliding saddle 6B and the frame guide slide rail constitute a linear movement pair, the second sliding saddle 6B is connected with one end of the second connecting rod 4B through the second rotating pair 5B, and the axis of the second rotating pair 5B is in the same direction as the corresponding linear moving pair , the other end of the second connecting rod 4B is connected with the moving platform 1 through the second ball joint.

The third active branch chain is composed of a third saddle 6C, a third rotating pair 5C, a third connecting rod 4C, and a third ball hinge 3C. The third saddle 6C and the rack guide rail constitute a linear movement pair, the third saddle 6C is connected with one end of the third connecting rod 4C through the third rotation pair 5C, and the axis of the third rotation pair 5C is in the same direction as the corresponding linear movement pair , the other end of the third connecting rod 4C is connected with the moving platform 1 through the third ball joint 3C.

The movement process of this device is:

As shown in Figures 2 and 3, the linear moving pair is used as the driving device of the mechanism, and the three-rotation parallel mechanism in this space adopts the driving mode of a servo motor plus a screw nut. The first lead screw nut 10A is connected with the saddle, the servo motor 8 transmits the rotation to the first lead screw nut 10A via the first lead screw 9A, and the first lead screw nut 10A drives the slide saddle to move in translation, and then the first lead screw nut 10A is transmitted to the first saddle 6A, thereby realizing the driving of the first active branch chain. In the same manner, the driving of the second active branch chain and the third active branch chain can be realized.

The linear moving pair is used as the driving device of the mechanism. When the driving device drives the first active branch chain, the second active branch chain, and the third active branch chain to generate the same input, the moving platform 1 realizes the normal direction of the orbiting platform. The rotation of the Z axis is coupled with the translational motion along the Z axis. When the driving device drives the three active branch chains to generate different inputs, the moving platform can realize the rotation around the X and Y axes, so the mechanism of the present invention It has three rotational degrees of freedom in space.

The above description of the present invention is only illustrative rather than restrictive, so the embodiments of the present invention are not limited to the above-mentioned specific embodiments. If a person of ordinary skill in the art is inspired by it, without departing from the gist of the present invention and the protection scope of the claims, other changes or modifications are made, all of which belong to the protection scope of the present invention.

Claims (4)

1. A novel space three-degree-of-freedom parallel mechanism, which comprises a frame, a moving platform is arranged above the frame, it is characterized in that: the frame is arranged symmetrically in an equilateral triangle, and the Each triangular side of the frame is provided with a guide rail, and the first, second, and third active branch chains are space-symmetrically distributed between the frame and the moving platform. The third active branch chain has the same structure, and each active branch chain includes a sliding saddle connected with the guide slide rail to form a linear movement pair, and the saddle is connected with one end of the connecting rod through a rotating pair, and the axis of the rotating pair is connected to the The directions of the guide rails corresponding to the swivel pair are in the same direction, and the other end of the connecting rod is connected with the moving platform through a hinge with three rotational degrees of freedom. 2. The novel space three-degree-of-freedom parallel mechanism according to claim 1, characterized in that: the hinge with three rotational degrees of freedom is a ball hinge. 3. A new type of three-degree-of-freedom parallel mechanism in space, which includes a frame, and a moving platform is arranged above the frame, characterized in that: the frame is arranged symmetrically in an equilateral triangle. Each triangular side of the frame is provided with a guide rail, and the first, second, and third active branch chains are space-symmetrically distributed between the frame and the moving platform. The third active branch chain has the same structure, and each active branch chain includes a sliding saddle connected with a guide slide rail to form a linear movement pair. A sliding rail is fixedly connected to the sliding saddle, and one end of the connecting rod is a slider , the slider is slidably connected with the slide rail to form a first moving pair, the moving axis of the slider is collinear with the axis of the connecting rod, and the other end of the connecting rod is connected to the moving pair through a hinge with three rotational degrees of freedom. The platform is connected. 4. The novel space three-degree-of-freedom parallel mechanism according to claim 2, characterized in that: the hinge with three rotational degrees of freedom is a ball hinge.