RPR plane three-degree-of-freedom parallel mechanism driven by moving pair P

Abstract

The invention discloses an RPR plane three-degree-of-freedom parallel mechanism driven by a moving pair P. The RPR plane three-degree-of-freedom parallel mechanism comprises a movable platform, the moving pair P, a fixed platform and RPR moving branch chains, each RPR moving branch chain comprises a connecting shaft, a sliding block, a lead screw sliding block, a lead screw, a lead screw supporting piece, a servo motor, a coupler and a connecting support, and the lead screw sliding block, the lead screw and the lead screw supporting piece form the moving pair P; the movable platform and the sliding block are connected through a bearing on the connecting shaft to form a driven end rotating pair. The sliding block and the lead screw form a lead screw module through a lead screw sliding block to serve as a driving end moving pair. The lead screw is connected with the lead screw supporting piece through a bearing, the lead screw is connected with the servo motor through a coupler, the servo motor drives the lead screw to move, and the three-degree-of-freedom planar motion of the whole mechanism is further pushed. According to the parallel mechanism, the whole mechanism is driven through the lead screw module, so that the mechanism has large driving force, and a larger load can be driven.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical manufacturing, and in particular to an RPR planar three-degree-of-freedom parallel mechanism driven by a moving pair P. Background Art

[0002] In the field of mechanical manufacturing technology, a new type of configuration that has attracted much attention and has been widely studied in recent decades is the parallel mechanism, which has been widely used in aerospace, industrial equipment, and precision positioning. The parallel mechanism is a form of robot that has a higher load-bearing capacity than a serial robot. In addition, the parallel mechanism has high end precision and high structural rigidity, but its scope in practical application is limited due to its small working space. Through clever design, the advantages of the parallel mechanism in high-precision positioning control in a small working space can be fully utilized to achieve excellent positioning effects, and the parallel mechanism driven by the moving pair P can provide a greater driving force to achieve a higher load of the parallel mechanism.

[0003] Traditional planar three-degree-of-freedom parallel mechanisms mostly use a parallel mechanism configuration driven by a rotating R pair. Under the same working space and rod size ratio conditions, the driving joint using a mobile pair P will have a greater driving force than the rotating pair R. Under the same conditions, the parallel mechanism of the present invention can drive a higher load by using the mobile pair P as the driving joint. At the same time, the parallel mechanism adopts a stacking structure design to facilitate the assembly of the mechanism. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, an object of the present invention is to provide an RPR planar three-degree-of-freedom parallel mechanism driven by a movable pair P.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] An RPR planar three-degree-of-freedom parallel mechanism driven by a moving pair P, comprising a moving platform, a moving pair P, a fixed platform and an RPR motion branch chain, each of the RPR motion branch chains comprising a connecting shaft, a slider, a lead screw slider, a lead screw, a lead screw support, a servo motor, a coupling and a connecting bracket, and the lead screw slider, the lead screw and the lead screw support constitute the moving pair P;

[0007] The moving platform and the slider are connected via bearings on the connecting shaft to form a driven end rotating pair;

[0008] The slider forms a screw module through the screw slider and the screw as a driving end moving pair;

[0009] The lead screw is connected to the lead screw support through a bearing, and the lead screw is connected to the servo motor through a coupling. The servo motor drives the lead screw to move, further promoting the three-degree-of-freedom planar motion of the overall mechanism.

[0010] Furthermore, the screw module also includes a screw module base plate, and the screw module base plate is connected to the fixed platform through the bearing on the stepped shaft to form a rotating pair.

[0011] Furthermore, the screw module base plate is slidably connected to the fixed platform via a pulley to provide support for the parallel mechanism.

[0012] Furthermore, the movable platform and the fixed platform are both in the shape of a rotationally symmetrical triangle, and their corner points are rounded.

[0013] Furthermore, the fixed platform is provided with a slide groove for connecting with the pulley.

[0014] Furthermore, when the fixed platform is located at the origin, the entire parallel mechanism presents a rotationally symmetrical structure.

[0015] Furthermore, the origin position refers to the position where the center point of the moving platform coincides with the center point of the fixed platform.

[0016] Furthermore, there are three RPR motion branches, and the three RPR motion branches are evenly distributed on the same circumference of the fixed platform.

[0017] Furthermore, the overall parallel mechanism adopts a layered stacking configuration, which is specifically divided into three layers. The fixed platform of the first layer provides support and rotation for the screw slider module of the second layer. The screw slider module of the second layer rotates through the rotating joint formed by the stepped shaft and the bearings on the shaft, driving the rotating joint formed by the connecting shaft and the bearings on the third layer, thereby further promoting the movement of the moving platform.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] The present invention introduces a novel planar three-degree-of-freedom parallel mechanism configuration RPR, which uses a moving pair P as the main driving element. Under the same working space and rod size ratio conditions, compared with the revolute pair R, using the moving pair P as the driving joint can provide a greater driving force. Under the same conditions, choosing the moving pair P as the driving joint can achieve a higher load drive.

[0020] At the same time, the parallel mechanism also adopts a stacking structure design to facilitate the easy assembly of the mechanism. This innovative design not only improves the load capacity of the mechanism, but also enhances its assembly efficiency, bringing a more flexible and efficient solution to the field of planar motion control. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 yes Figure 1 Top view of the . DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0024] like Figure 1 and Figure 2 As shown, an RPR planar three-degree-of-freedom parallel mechanism driven by a moving pair P has a large working space and driving force and can drive a higher load. The parallel mechanism consists of a fixed platform 10, a moving platform 1, a moving pair P, an RPR motion branch chain, etc. The fixed platform 10 is in the shape of a rotationally symmetrical triangle, and its corners are rounded. A slide groove is provided on the fixed platform 10 to support the rotational movement of the moving pair P. The moving platform 1 also has a rotationally symmetrical triangular shape, and its corners are rounded.

[0025] The moving platform has three degrees of freedom, including two translational degrees of freedom within the plane where it is located and a rotational degree of freedom perpendicular to the plane where it is located.

[0026] The three RPR motion branches are evenly distributed at intervals of 120° on the same circumference of the fixed platform 10. Each RPR motion branch has the same structure, including a connecting shaft 2, a slider 3, a screw slider 4, a screw 5, a screw support 6, a servo motor 9, a coupling 8, a connecting bracket 11 and a screw module bottom plate 14.

[0027] The screw slider 4, the screw 5 and the screw support 6 constitute a moving pair P.

[0028] The moving platform 1 and the slider 3 are connected via a bearing on the connecting shaft to form a driven end rotating pair.

[0029] The slider 3 forms a screw module through the screw slider 4 and the screw 5 as a driving end moving pair.

[0030] In this mechanism, the moving pair serves as the driving end, and three identical moving pairs P drive the mechanism to perform three-degree-of-freedom planar motion.

[0031] The specific connection method is as follows:

[0032] The screw rod 5 is fixedly connected to the screw rod support 6 through a bearing, and the screw rod 4 is connected to the servo motor 9 through a coupling 8. The servo motor 9 drives the screw rod 5 to move, thereby promoting the movement of the entire mechanism. The servo motor 9 is fixedly connected to the screw rod support 6 through a connecting bracket 11. The screw rod module base plate 14 is connected to the fixed platform 10 through the bearing 13 on the stepped shaft 12 to form a rotating pair. In order to increase the rigidity of the overall mechanism, the screw rod module base plate and the fixed platform 10 are slidably connected through a pulley 7 to provide certain support. When the fixed platform is at the origin, the overall mechanism presents a rotationally symmetrical configuration. The overall mechanism provides a driving force through the servo motor 9 to push the screw rod 5 to move, thereby realizing the movement of the moving pair P.

[0033] To further explain, the origin position refers to the position where the center point of the moving platform coincides with the center point of the fixed platform, that is, the initial position of the moving platform of the mechanism.

[0034] To further explain, there are two connections between the screw module base plate and the fixed platform, one is a rotation connection and the other is a pulley-groove connection.

[0035] The overall structure of the platform adopts a layered stacking configuration. The first layer is mainly composed of a fixed platform 10, which provides support and a rotating joint for the second layer of the screw slider module. The screw slider module of the second layer rotates through the rotating joint formed by the stepped shaft 12 and the shaft bearing, driving the rotating joint formed by the connecting shaft 2 and the shaft bearing in the third layer to push the moving platform 1 to move. This structural design makes the overall mechanism have higher rigidity and stability, and can adapt to larger working space and load requirements.

[0036] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An RPR planar three-degree-of-freedom parallel mechanism driven by a moving pair P, characterized in that: It includes a moving platform, a moving pair P, a fixed platform and an RPR motion branch chain, each of which includes a connecting shaft, a slider, a lead screw slider, a lead screw, a lead screw support, a servo motor, a coupling and a connecting bracket, and the lead screw slider, the lead screw and the lead screw support constitute the moving pair P; The moving platform and the slider are connected via bearings on the connecting shaft to form a driven end rotating pair; The slider forms a screw module through the screw slider and the screw as a driving end moving pair; The lead screw is connected to the lead screw support through a bearing, and the lead screw is connected to the servo motor through a coupling. The servo motor drives the lead screw to move, further promoting the three-degree-of-freedom planar motion of the overall mechanism.

2. The RPR planar three-degree-of-freedom parallel mechanism according to claim 1, characterized in that: The lead screw module also includes a lead screw module bottom plate, and the lead screw module bottom plate is connected with the fixed platform through the bearing on the stepped shaft to form a rotating pair.

3. The RPR planar three-degree-of-freedom parallel mechanism according to claim 2, characterized in that: The screw module base plate is slidably connected to the fixed platform via a pulley to provide support for the parallel mechanism.

4. The RPR planar three-degree-of-freedom parallel mechanism according to claim 1, characterized in that: The movable platform and the fixed platform are both in the shape of a rotationally symmetrical triangle, and their corner points are rounded.

5. The RPR planar three-degree-of-freedom parallel mechanism according to claim 3, characterized in that: The fixed platform is provided with a slide groove for connecting with the pulley.

6. The RPR planar three-degree-of-freedom parallel mechanism according to any one of claims 1 to 5, characterized in that: When the fixed platform is located at the origin, the entire parallel mechanism presents a rotationally symmetrical structure.

7. The RPR planar three-degree-of-freedom parallel mechanism according to claim 6, characterized in that: The origin position refers to the position where the center point of the moving platform coincides with the center point of the fixed platform.

8. The RPR planar three-degree-of-freedom parallel mechanism according to claim 1, characterized in that: There are three RPR motion branches, and the three RPR motion branches are evenly distributed on the same circumference of the fixed platform.

9. The RPR planar three-degree-of-freedom parallel mechanism according to claim 1, characterized in that: The overall parallel mechanism adopts a layered stacking configuration, which is specifically divided into three layers. The fixed platform of the first layer provides support and rotation for the screw slider module of the second layer. The screw slider module of the second layer rotates through the rotating joint composed of the stepped shaft and the bearing on the shaft, driving the rotating joint composed of the connecting shaft and the bearing on the shaft of the third layer, further promoting the movement of the moving platform.

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