A two-translational-one-rotational parallel robot mechanism with rotating branched chains

Abstract

The application provides a two-rotation-one-translation parallel robot mechanism containing a rotating branch chain, which can reduce the overall volume of the mechanism, reduce the system complexity and has a wider application scene on the basis of having a larger reachable workspace range. One rotation degree of freedom is realized through two rotation pairs in the rotating branch chain and three universal joints, one rotation degree of freedom is realized through the second rotation pair in the fixed branch chain and the three universal joints, one movement degree of freedom is realized through the three rotation pairs and the three movement pairs, and the movement of the moving platform is ensured to be two-rotation-one-translation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, in particular to a two-rotation one-translation parallel robot mechanism containing a rotating branch chain. BACKGROUND

[0002] The two-rotation one-translation parallel mechanism is not affected by the moving motion of the mechanism in the two rotation directions, and in the initial position and the single rotation position, the axes of the two rotation directions are located on the moving platform. Due to the good posture adjustment capability of the two-rotation one-translation parallel mechanism, it is widely used, and many technical personnel are committed to researching such mechanism. For example, the patent with publication number CN118478345A discloses a PU type parallel robot mechanism without accompanying motion; by setting the universal joint on the sliding of the circular arc guide rail on the first branch chain and the second branch chain, the accompanying motion of the mechanism can be avoided, so that the parallel mechanism of the present application avoids the occurrence of accompanying motion, and improves the motion accuracy of the moving platform. However, it is found in actual use that the driving pair of the mechanism is a moving pair, and the moving pair needs to be based on the guide rail to realize driving when the moving platform moves, resulting in a relatively complex structure, which makes it unsuitable for some scenes. SUMMARY

[0003] In order to solve the problem of complex overall structure of the existing two-rotation one-translation parallel mechanism driven by the moving pair, the present application provides a two-rotation one-translation parallel robot mechanism containing a rotating branch chain, which can reduce the overall volume of the mechanism, reduce the system complexity, and has a wider application scene on the basis of having a larger reachable workspace range.

[0004] The technical scheme of the present application is as follows: a two-rotation one-translation parallel robot mechanism containing a rotating branch chain, comprising: a moving platform, a base and a unit branch chain, the unit branch chain is arranged between the moving platform and the base;

[0005] Characterized in that:

[0006] It further comprises: a rotating connecting plate and a rotating pair one;

[0007] Each unit branch chain comprises: a universal joint, a moving pair and a rotating pair two connected in sequence; the universal joint at the top end of the unit branch chain is connected to the moving platform;

[0008] The unit branch chain is arranged as three, one of which is a fixed branch chain, and the other two constitute a rotating branch chain;

[0009] The rotating pair two at the bottom end of the fixed branch chain is connected to the base;

[0010] The rotating connecting plate and the base constitute the rotating pair one; the rotating shaft of the rotating pair one is perpendicular to the bottom surface of the base; in the rotating branch chain, the rotating shafts of the two rotating pairs two at the bottom of each unit branch chain are parallel to each other and are connected to the rotating connecting plate, and the two rotating pairs two are symmetrically arranged on both sides of the rotating pair one;

[0011] The rotating shafts of the two rotating pairs two at the bottom of each unit branch chain are parallel to the bottom surface of the base;

[0012] The universal pair includes two rotating shafts perpendicular to each other, one of which is parallel to the rotating shaft of the rotating pair two;

[0013] In the rotating branch chain, the two rotating shafts of the universal pair that are not parallel to the rotating shaft of the rotating pair two are collinear;

[0014] The three rotating pairs two are arranged as driving pairs.

[0015] It is further characterized in that:

[0016] The plane formed by the rotating branch chain is perpendicular to the plane of the base;

[0017] The base includes a rotating branch chain base and a fixed branch chain base, both of which are located on the same plane;

[0018] The rotating connecting plate has an Ω-shaped structure, wherein the convex part is shaped to adapt to the shape of the rotating branch chain base, and is sleeved on the rotating branch chain base to form the rotating pair one;

[0019] The moving pair includes a sleeve and a sliding rod, the bottom end of the sleeve is connected to the rotating pair two, and one end of the sliding rod is inserted into the top end of the sleeve, and the other end is connected to the universal pair.

[0020] The application provides a two-rotation-one-movement parallel robot mechanism with a rotating branch chain, which can realize one rotation degree of freedom through three universal pairs and two rotating pairs two in the rotating branch chain, realize one rotation degree of freedom through the rotating pair two in the fixed branch chain and three universal pairs, realize one movement degree of freedom through three rotating pairs two and three moving pairs, and ensure that the moving platform can realize two-rotation-one-movement motion; in the technical scheme, the three rotating pairs two are arranged as driving pairs, without the need for additional auxiliary structures, so that driving can be realized, the complexity of the mechanism is effectively simplified, and the overall weight of the mechanism is reduced; at the same time, the rotating pair one with the rotating shaft perpendicular to the plane of the base is introduced into the parallel mechanism, the rotating branch chain based on the rotating pair one is arranged to realize overall rotation, and the accompanying motion of the mechanism is avoided; the motion precision is improved; and due to the introduction of the rotating branch chain and the rotating pair one, the moving platform still has a two-rotation-one-movement degree of freedom, and due to the large rotation angle of the rotating branch chain, the rotation angle of the moving platform is improved, so that the flexibility of the mechanism is higher.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the overall structure of the two-rotation one-translation parallel robot mechanism with a rotating branch chain in the present application;

[0022] Figure 2 is an example of a moving position of the parallel robot mechanism in the present application;

[0023] Figure 3 is an example of a rotating position of the parallel robot mechanism in the present application 1;

[0024] Figure 4 is an example of a rotating position of the parallel robot mechanism in the present application 2.

[0025] wherein 1, first unit branch chain; 11, first rotating pair two; 12, first moving pair; 13, first universal joint; 14, sleeve; 15, slide rod;

[0026] 2, second unit branch chain; 21, second rotating pair two; 22, second moving pair; 23, second universal joint;

[0027] 3, third unit branch chain; 31, third rotating pair two; 32, third moving pair; 33, third universal joint;

[0028] 4, moving platform; 5, rotating pair one; 6, rotating branch chain base; 7, rotating connecting plate; 8, fixed branch chain base. DETAILED DESCRIPTION

[0029] As shown in Figures 1-4 the present application includes a two-rotation one-translation parallel robot mechanism with a rotating branch chain, which includes a moving platform 4, a base, a rotating connecting plate 7, a rotating pair one 5 and a unit branch chain, the unit branch chain being arranged between the moving platform 4 and the base.

[0030] In specific implementation, the base can be arranged as a complete structure or in a split form. In the present embodiment, the base is arranged in a split form for easy installation. Specifically, the base includes a rotating branch chain base 6 and a fixed branch chain base 8, both of which are located on the same plane.

[0031] The unit branch chain in the present application is arranged as three, specifically a first unit branch chain 1, a second unit branch chain 2 and a third unit branch chain 3. The three unit branch chains have the same structure. Each unit branch chain includes a universal joint, a moving pair and a rotating pair two connected in sequence; the universal joint at the top of each unit branch chain is connected to the moving platform 4. The rotating shaft of the rotating pair two at the bottom of each unit branch chain is parallel to the plane of the base.

[0032] As shown in Figure 1The structure of the unit branch chain is described by taking the first unit branch chain 1 as an example. The first unit branch chain 1 comprises, from top to bottom, a first universal pair 13, a first moving pair 12, and a first rotating pair two 11. The moving pair and the universal pair are implemented based on the structure in the prior art. Figure 1 In the embodiment, the first moving pair 12 comprises a sleeve 14 and a slide rod 15. The bottom end of the sleeve 14 is connected to the first rotating pair two 11, and one end of the slide rod 15 is inserted into the top end of the sleeve 14, and the other end is connected to the first universal pair 13. The rotating shaft m4 of the first rotating pair two 11 is parallel to the plane on which the base is located. The first universal pair 13 is arranged on the bottom end face of the moving platform 4 through a connecting structure.

[0033] In order to simplify the structure of the system and eliminate the accompanying movement, the rotating pair one whose rotating shaft is perpendicular to the plane on which the base is located is introduced into the parallel mechanism, and the rotating branch chain which realizes overall rotation based on the rotating pair one is arranged. One of the three unit branch chains is taken as a fixed branch chain, and the other two unit branch chains jointly constitute a rotating branch chain.

[0034] In the embodiment, the third unit branch chain 3 is taken as the fixed branch chain, and the first unit branch chain 1 and the second unit branch chain 2 jointly constitute the rotating branch chain. The third rotating pair two 32 at the bottom end of the third unit branch chain 3 is connected to the base 8 for the fixed branch chain. The plane constituted by the rotating branch chain is perpendicular to the plane on which the base is located.

[0035] The rotating connecting plate 7 and the base constitute the rotating pair one 5, and the rotating shaft h of the rotating pair one 5 is perpendicular to the bottom plane on which the base is located. In the embodiment, the rotating connecting plate 7 is of an Ω type structure, wherein the convex part shape is adapted to the shape of the rotating branch chain base 6, and is sleeved on the rotating branch chain base 6 to constitute the rotating pair one 5, so as to ensure stable rotation during rotation.

[0036] In the rotating branch chain, the rotating shafts of the two rotating pair twos at the bottom ends of the two unit branch chains are parallel to each other and are respectively connected to the rotating connecting plate 7, and the two rotating pair twos are symmetrically arranged on the two sides of the rotating pair one 5. That is, the first unit branch chain 1 and the second unit branch chain 2 are symmetrically arranged on the rotating connecting plate 7 with the rotating pair one 5 as the center through the first rotating pair two 11 and the second rotating pair two 12 at the bottom ends. The rotating shaft m4 of the first rotating pair two 11 and the rotating shaft m5 of the second rotating pair two 12 are parallel to each other.

[0037] In the present application, the universal pair at the top of each unit branch chain comprises two rotating shafts perpendicular to each other, one of which is parallel to the rotating shaft of the rotating pair two. In the rotating branch chain, the two rotating shafts of the universal pairs of the two unit branch chains which are not parallel to the rotating shaft of the rotating pair two are collinear. That is, as shown in FIG. 1, the rotating shaft m4 of the first rotating pair two 11 and the rotating shaft m5 of the second rotating pair two 12 are parallel to each other, and the rotating shafts of the universal pairs of the first unit branch chain 1 and the second unit branch chain 2 are collinear. Figure 4As shown, the two pivots m1 and n1 of the first universal joint 13 are perpendicular to each other; the two pivots m1 and n2 of the second universal joint 23 are perpendicular to each other; and the two pivots m3 and n3 of the third universal joint 33 are perpendicular to each other. The pivot m4 of the first revolute joint 11 and the pivot m5 of the second revolute joint 21 are parallel to each other. The pivot n4 of the third revolute joint 31 is the pivot of the second revolute joint.

[0038] Rotating shafts m1, m2, m4, and m5 are parallel to each other. Rotating shafts n1 and n2 are collinear, forming a coaxial U. Rotating shafts n4 and n3 are parallel to each other.

[0039] In this application, three revolute joints, namely, the first revolute joint 11, the second revolute joint 21, and the third revolute joint 31, are configured as driving joints. The rotation of these three revolute joints is achieved by a motor (not marked in the figure). The remaining kinematic joints are follower joints and do not require motor drive.

[0040] by Figure 1 In the initial state, the moving platform 4 is horizontal, and the first unit branch 1, the second unit branch 2, and the third unit branch 3 all make the same angle with the horizontal plane. At this time, the plane formed by the rotating branches is perpendicular to the plane of the base, and the plane of the fixed branches is perpendicular to the plane of the rotating branches.

[0041] In this embodiment, the moving platform is triangular, and three unit branches are respectively connected to the three vertices of the moving platform. The first revolute joint 21, the first revolute joint 22, and the third revolute joint 22 are of equal height.

[0042] based on Figure 1 In the initial state, the first rotary joint 11, the second rotary joint 21, and the third rotary joint 31 rotate under the drive of the motor. In this embodiment, the three drive joints rotate synchronously in a direction away from the horizontal plane, the first prismatic joint 12, the second prismatic joint 22, and the third prismatic joint 32 follow suit, and the moving platform 4 moves upward perpendicular to the horizontal direction, reaching... Figure 2 As shown in the diagram, when the first revolute joint 11, the second revolute joint 21, and the third revolute joint 31 rotate synchronously towards the horizontal plane, the moving platform 4 undergoes a downward movement perpendicular to the horizontal direction. That is, the first prismatic joint 12, the second prismatic joint 22, and the third prismatic joint 32, together with the three revolute joints, can achieve one degree of freedom of movement.

[0043] exist Figure 2 Based on this, the third rotary joint 31 remains stationary, while the first rotary joint 11 and the second rotary joint 21 rotate under the drive of the motor. In this embodiment, the first rotary joint 11 moves away from the horizontal plane, and the second rotary joint 21 rotates towards the horizontal plane. The first prismatic joint 12 and the second prismatic joint 22 follow suit, causing the moving platform 4 to rotate in one direction.Figure 3 The rotation axis is a rotation axis m3 of the third universal joint 33. Figure 2 Figure 3 During the movement from the state of The first rotation pair 11 and the second rotation pair 21 remain unchanged, and the third rotation pair 31 rotates under the driving of the motor.

[0044] In the embodiment, the third rotation pair 31 rotates towards the horizontal plane, and the third universal joint 33 rotates towards the horizontal plane. Figure 3 Because the included angle between the first unit branch chain 1 and the second unit branch chain 2 and the base of the fixed branch chain changes, the first moving pair 12, the second moving pair 22 and the third moving pair 32 respectively follow, and the rotation pair 5 also follows, and the moving platform 4 generates a second direction rotation movement.

[0045] The technical scheme of the application improves the existing parallel mechanism, adds a pair of rotatable branch chains, so that the moving platform still has two rotation and one translation degrees of freedom, and because the rotatable angle of the rotating branch chain is large, the rotation angle of the moving platform is increased, and the flexibility of the mechanism is higher.

[0046] Therefore, the two-rotation and one-translation parallel mechanism in the application has the advantages of general two-rotation and one-translation parallel mechanisms, and abandons the shortcomings that the reachable workspace of some mechanisms is small; the two rotatable branch chains are fixed, so that the rigidity of the mechanism as a whole is higher, the movement process is more stable, and the mechanism can better adapt to high-precision working scenes. Moreover, the driving pairs in the mechanism of the application are all rotation pairs, the structure is simple, the overall weight and volume of the mechanism are reduced, and the mechanism avoids occupying a large space.

Claims

1. A parallel robot mechanism with two rotations and one transfer, comprising a rotating branch, wherein: A moving platform, a base, and unit branches, wherein the unit branches are disposed between the moving platform and the base; Its features are: It also includes: a rotating connecting plate and a rotating pair; Each unit branch includes: a universal joint, a prismatic joint, and a revolute joint connected in sequence; the universal joint at the top of the unit branch is connected to the moving platform; The unit branch is configured with 3 branches, one of which is a fixed branch, and the other two unit branches together form a rotating branch. The rotating joint at the bottom end of the fixed branch is connected to the base; The rotating connecting plate and the base constitute the first rotating pair; the axis of rotation of the first rotating pair is perpendicular to the bottom surface of the base; in the rotating chain, the axes of rotation of the second rotating pairs at the bottom of the two unit chains are parallel to each other and are respectively connected to the rotating connecting plate, and the two second rotating pairs are symmetrically arranged on both sides of the first rotating pair. The rotation axis of the rotating joint at the bottom of each unit branch is parallel to the plane of the base; The universal joint includes two mutually perpendicular shafts, one of which is parallel to the shaft of the second revolute joint. In the rotating chain, the two rotating axes of the universal joints of the two unit chains are not parallel to the collinearity of the two rotating axes of the rotating joint; The three revolute joints are configured as driving joints; The third unit branch is used as a fixed branch, and the first unit branch and the second unit branch together form a rotating branch. The two shafts m1 and n1 of the first universal joint are perpendicular to each other; the two shafts m2 and n2 of the second universal joint are perpendicular to each other; the two shafts m3 and n3 of the third universal joint are perpendicular to each other; the shafts m4 and m5 of the second revolute joint are parallel to each other; the shaft of the second revolute joint is n4. Rotating shafts m1, m2, m4, and m5 are parallel to each other; rotating shafts n1 and n2 are collinear, forming a coaxial U; rotating shafts n4 and n3 are parallel to each other.

2. The parallel robot mechanism with a rotating branch and a two-rotation-one-transfer mechanism according to claim 1, characterized in that: The plane formed by the rotating branches is perpendicular to the plane of the base.

3. The parallel robot mechanism with a rotating branch and a two-rotation-one-transfer mechanism according to claim 1, characterized in that: The base includes a rotating branch base and a fixed branch base, both located on the same plane.

4. The parallel robot mechanism with a rotating branch and a transfer mechanism according to claim 3, characterized in that: The rotating connecting plate has an Ω-shaped structure, wherein the shape of the protruding part is adapted to the shape of the rotating support base, and is fitted onto the rotating support base to form the first rotating pair.

5. The parallel robot mechanism with a rotating branch and a transfer mechanism according to claim 1, characterized in that: The movable pair includes: A sleeve and a sliding rod are provided. The bottom end of the sleeve is connected to the second rotating joint, and one end of the sliding rod is inserted from the top end of the sleeve, while the other end is connected to the universal joint.

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