CN111409058A - A parallel mechanism with two-dimensional translation - Google Patents

Abstract

The invention discloses a parallel mechanism with two-dimensional translation, which comprises a fixed frame and a movable platform, wherein three telescopic branched chains with the same structure are connected between the fixed frame and the movable platform; the telescopic branched chain comprises a conical gear pair, a driven synchronous belt pulley, a connecting shaft and a screw pair consisting of a nut and a screw rod, wherein the nut is coaxially and fixedly connected with a driven gear in the conical gear pair, and the driven synchronous belt pulley is coaxially and fixedly connected with a driving gear in the conical gear pair; the telescopic branched chains on one side are driven by a first motor, and the other two telescopic branched chains are driven by a second motor; the axis of the telescopic branch on one side is coplanar or parallel to the plane formed by the axes of the other two telescopic branches; when three telescopic branched chains of two motors are controlled to realize telescopic motion, the movable platform can be driven to realize two-dimensional translation. The invention utilizes the characteristics of the bevel gear pair to drive the nut to rotate so that the screw rod can swing while moving linearly, thereby realizing two-dimensional translation of the movable platform, and the mechanism has fewer components, high rigidity and high flexibility.

Description

A parallel mechanism with two-dimensional translation

technical field

The invention relates to a novel robot, in particular to a parallel mechanism with two-dimensional translation of the robot.

Background technique

According to patents CN101244557A and US4976572 (or WO7703527), the existing parallel mechanism capable of realizing two-dimensional translation includes three groups of active branch chains and a moving platform, and each group of branch chains includes a connecting rod. One end of the connecting rod has only one rotational degree of freedom relative to the fixed frame, and the other end is connected to the moving platform through a hinge with only two rotational degrees of freedom, thereby ensuring two-dimensional translation of the moving platform. The limitation of the above mechanism is that the overall flexibility of the mechanism is poor, and it is only suitable for handling heavy objects.

SUMMARY OF THE INVENTION

In view of the above-mentioned prior art, the present invention proposes to provide a modular two-dimensional translation parallel mechanism with high flexibility and large working space.

In order to solve the above technical problems, a parallel mechanism with two-dimensional translation proposed by the present invention includes a fixed frame and a moving platform, and three retractable branch chains with the same structure are connected between the fixed frame and the moving platform; The retractable branch chain includes a bevel gear pair, a passive synchronous pulley, a connecting shaft and a screw pair composed of a nut and a lead screw. The nut and the passive gear in the bevel gear pair are coaxially fixed, and the connection One end of the shaft is a support shaft segment, the other end of the connecting shaft is a sleeve, the axis of the sleeve and the support shaft segment are perpendicular to each other, and the support shaft segment and the fixed frame are connected by a rotating pair; The sleeve is sleeved on the hub of the driven gear to form a rotating pair, and the passive synchronous pulley is fixed coaxially with the driving gear in the bevel gear pair; one end of the lead screw is connected to the moving platform. Among the three telescopic branches, the telescopic branch on one side is recorded as the right telescopic branch, the telescopic branch in the middle is recorded as the first telescopic branch on the left, and the other one is the first telescopic branch on the left. The side retractable branch is recorded as the second left retractable branch; the axis of the right retractable branch is formed by the axis of the first left retractable branch and the axis of the second left retractable branch. The planes are coplanar or parallel; the passive synchronous pulley in the right telescopic branch is driven by the first motor and through the belt drive; the first telescopic branch on the left and the second telescopic branch on the left The passive synchronous pulleys are all driven by the second motor and through the belt drive; driven by the first motor and the second motor, the right telescopic branch chain, the left first telescopic branch chain and the left second telescopic branch While the chain realizes telescopic motion, the moving platform realizes two-dimensional translation.

Further, in the parallel mechanism with two-dimensional translation according to the present invention, the driving gear in each telescopic branch chain is connected with the fixed frame through a rotating pair.

In the left first telescopic branch chain and the left second telescopic branch chain: the axes of the two passive synchronous pulleys are parallel; the axes of the rotating pair between the two lead screws and the moving platform are parallel. The center distance of the two axes is A; the axes of the two driven gears are parallel, and the center distance of the two driven gears is A.

Both the first motor and the second motor are fixedly connected to the fixing frame; the output shaft of the first motor is provided with a first active synchronous pulley, and the first active synchronous pulley is connected to the right A first synchronous belt is connected between the passive synchronous pulleys in the side retractable branch chain; a second active synchronous pulley is arranged on the output shaft of the second motor, and the second active synchronous pulley is connected to the left A second synchronous belt is connected between the passive synchronous pulley in the side first telescopic branch chain and the passive synchronous pulley in the left second telescopic branch chain.

Compared with the prior art, the beneficial effects of the present invention are:

In the invention, the principle that one bevel gear of the bevel gear pair can rotate and revolve is used to realize that the lead screw can swing around the connecting shaft while synchronously expanding and contracting in the nut bevel gear, thereby realizing the two-dimensional translation of the moving platform, and the branch chain is only Under tension and compression load, the structure is simple and compact, which increases the flexibility of the mechanism and reduces the overall quality of the mechanism.

Description of drawings

Fig. 1 is the front view of the parallel mechanism with two-dimensional translation of the present invention;

Fig. 2 is the top view of the parallel mechanism shown in Fig. 1;

Fig. 3 is the axonometric view of the parallel mechanism shown in Fig. 1;

Figure 4 is a sectional view of the structure of a telescopic branch chain in the present invention.

In the picture:

1-Fixed frame 2-Moving platform 31-First motor

32-Second motor 41-First drive synchronous pulley 42-Second drive synchronous pulley

51-First timing belt 52-Second timing belt 6-Right telescopic branch chain

7- The first telescopic branch on the left side 8- The second telescopic branch on the left side 9- Lead screw

10-nut 11-bevel gear pair 12-passive synchronous pulley

13-connecting shaft 14-passive gear 15-drive gear

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments do not limit the present invention by any means.

As shown in FIG. 1 , FIG. 2 and FIG. 3 , a parallel mechanism with two-dimensional translation proposed by the present invention includes a fixed frame 1 and a moving platform 2 , and the fixed frame 1 and the moving platform 2 are connected There are three stretchable branches of the same structure.

The retractable branch chain includes a bevel gear pair 11 , a passive synchronous pulley 12 , a connecting shaft 13 and a screw pair composed of a nut 10 and a lead screw 9 , the nut 10 and the bevel gear pair 11 The driven gear 14 Coaxially fixed, one end of the connecting shaft 13 is a support shaft section, the other end of the connecting shaft 13 is a sleeve, the axis of the sleeve and the support shaft section are perpendicular to each other, and the support shaft section is perpendicular to the axis of the support shaft section. The fixed frame 1 is connected by a rotating pair; the sleeve is sleeved on the hub of the driven gear 14 to form a rotating pair, and the driven synchronous pulley 12 is coaxial with the driving gear 15 in the bevel gear pair 11 Fixed connection, the driving gear 15 in each retractable branch chain is connected with the fixed frame 1 through a rotating pair.

The other ends of the three telescopic branch chains are connected with the moving platform 2 through a rotating pair, that is, one end of the lead screw 11 and the moving platform 2 are connected by a rotating pair.

For the convenience of description, the telescopic branch on one side of the three telescopic branches is denoted as the right telescopic branch 6, the telescopic branch in the middle position is denoted as the left first telescopic branch 7, and the other The retractable branch chain on the side is marked as the second retractable branch chain on the left side 8; The planes formed by the axes are coplanar or parallel.

The left first telescopic branch 7 and the left second telescopic branch 8 are parallel to the axis of rotation of the fixed frame, and the left first telescopic branch 7 and the left second telescopic branch are The chain 8 is parallel to the axis of rotation of the moving platform, and the center lines of the bevel gears in the first telescopic branch chain 7 on the left side and the second telescopic branch chain on the left side 8 are parallel and equal to the two on the left side. The connecting line of the rotating sub-center connecting the retractable branch chain and the moving platform. Specifically, as shown in FIG. 2 , in the left first telescopic branch chain 7 and the left second telescopic branch chain 8: the axes of the two passive synchronous pulleys 12 are parallel; The axes of the rotating pair between the moving platforms 2 are parallel, and the center distance of the two axes is A; the axes of the two driven gears 14 are parallel, and the center distance of the two driven gears 14 is A.

The passive synchronous pulley in the right telescopic branch chain 6 is driven by the first motor 31 and driven by the belt; the passive synchronous belt in the first left telescopic branch 7 and the left second telescopic branch 8 The wheels are driven by the second motor 32 and driven by the belt; that is, the first motor 31 and the second motor 32 are fixedly connected to the fixing frame 1 ; the output shaft of the first motor 31 is provided with The first active synchronous pulley 41, a first synchronous belt 51 is connected between the first active synchronous pulley 41 and the passive synchronous pulley 12 in the right telescopic branch chain 6; the second motor 32 The output shaft is provided with a second active synchronous pulley 42, the second active synchronous pulley 42 and the passive synchronous pulley 12 in the first telescopic branch chain 7 on the left side and the second adjustable pulley on the left side. A second synchronous belt 52 is connected between the passive synchronous pulleys 12 in the telescopic branch chain 8 .

By controlling the first motor 31 and the second motor 32, the telescopic motion of the three telescopic branches can be realized. Driven by the first motor 31 and the second motor 32, the right telescopic The telescopic branch chain 7 and the second telescopic branch chain 8 on the left side realize the telescopic movement and simultaneously drive the moving platform 2 to move up and down and left and right, so that the moving platform 2 can realize two-dimensional translation.

To sum up, in the parallel mechanism of the present invention, using the meshing characteristics of the bevel gear pair, the drive nut rotates so that the lead screw can swing while moving linearly, realizing two-dimensional translation of the moving platform, and the mechanism has few components, high rigidity and high flexibility. .

Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the inspiration of the present invention, many modifications can be made without departing from the spirit of the present invention, which all belong to the protection of the present invention.

Claims (4)

1. A parallel mechanism with two-dimensional translation comprises a fixed frame (1) and a movable platform (2), and is characterized in that three telescopic branched chains with the same structure are connected between the fixed frame (1) and the movable platform (2);

the telescopic branched chain comprises a bevel gear pair (11), a driven synchronous pulley (12), a connecting shaft (13) and a screw pair consisting of a nut (10) and a lead screw (9), wherein the nut (10) is coaxially and fixedly connected with a driven gear (14) in the bevel gear pair (11), one end of the connecting shaft (13) is a supporting shaft section, the other end of the connecting shaft (13) is a sleeve, the sleeve is perpendicular to the axis of the supporting shaft section, and the supporting shaft section is connected with the fixed frame (1) through a rotating pair; the sleeve is sleeved on a hub of the driven gear (14) to form a rotating pair, and the driven synchronous belt wheel (12) is coaxially and fixedly connected with a driving gear (15) in the bevel gear pair (11);

one end of the lead screw (11) is connected with the movable platform (2) through a revolute pair;

among the three telescopic branched chains, the telescopic branched chain at one side is marked as a right telescopic branched chain (6), the telescopic branched chain at the middle position is marked as a left first telescopic branched chain (7), and the telescopic branched chain at the other side is marked as a left second telescopic branched chain (8); the axis of the right telescopic branch (6) is coplanar or parallel to the plane formed by the axis of the left first telescopic branch (7) and the axis of the left second telescopic branch (8); a driven synchronous belt wheel in the right telescopic branched chain (6) is driven by a first motor (31) through belt transmission; the driven synchronous belt wheels in the left first telescopic branched chain (7) and the left second telescopic branched chain (8) are driven by a second motor (32) through belt transmission;

under the driving of a first motor (31) and a second motor (32), the right telescopic branched chain (6), the left first telescopic branched chain (7) and the left second telescopic branched chain (8) realize telescopic motion, and meanwhile, the movable platform (2) realizes two-dimensional translation.

2. Parallel mechanism with two-dimensional translational motion according to claim 1, characterized in that the driving gear (15) of each telescopic branch is connected to the fixed frame (1) through a revolute pair.

3. Parallel mechanism with two-dimensional translation according to claim 1, characterized in that, of said first (7) and second (8) branches:

the axes of the two driven synchronous pulleys (12) are parallel;

the two screw rods (9) are parallel to the axis of the revolute pair between the movable platform (2), and the center distance of the two axes is A;

the axes of the two driven gears (14) are parallel, and the center distance of the two driven gears (14) is A.

4. The parallel mechanism with two-dimensional translation according to claim 1, wherein the first motor (31) and the second motor (32) are both fixedly connected with the fixing frame (1);

a first driving synchronous belt wheel (41) is arranged on an output shaft of the first motor (31), and a first synchronous belt (51) is connected between the first driving synchronous belt wheel (41) and a driven synchronous belt wheel (12) in the right telescopic branched chain (6);

a second driving synchronous belt wheel (42) is arranged on an output shaft of the second motor (32), and a second synchronous belt (52) is connected between the second driving synchronous belt wheel (42) and a driven synchronous belt wheel (12) in the left first telescopic branched chain (7) and a driven synchronous belt wheel (12) in the left second telescopic branched chain (8).

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