CN203092550U - Three-translation freedom degree robot mechanism with near support parallelogram and far support paralleling rod - Google Patents

Abstract

The utility model discloses a three-translation freedom degree robot mechanism with a near support parallelogram and a far support paralleling rod and belongs to the technical field of robots. The robot mechanism comprises a machine frame, a movable platform and three branched chains in the same structural mode, the three branched chains are jointly connected with the machine frame and the movable platform, each branched chain is composed of a driving arm, an auxiliary driving arm, a double-lining frame joint, a first Hooke spherical hinge, the far support paralleling rod and a second Hooke spherical hinge, the three branched chains are evenly distributed, and the three branched chains are respectively provided with a driving device fixed on the machine frame, and the driving devices are connected with the driving arm. A branched chain structure with the near support parallelogram and the far support paralleling rod is adopted by the three-translation freedom degree robot mechanism to limit rotation freedom degree of the movable platform, a structural mode of the near support parallelogram and the far support paralleling rod guarantees that the whole mechanism has big stiffness, attitude errors caused by elasticity of a steel wire are effectively avoided, and the three-translation freedom degree robot mechanism is simple in manufacturing, convenient to install and debug and low in mechanism manufacturing cost.

Description

A three-translational degree-of-freedom robot mechanism with near-frame parallelogram-far frame juxtaposed rods

technical field

The utility model belongs to the technical field of robots, and in particular relates to a robot mechanism with three translational degrees of freedom comprising a parallelogram of a near frame and parallelograms of a far frame.

Background technique

US Patent No. 4,976,572 discloses a spatially symmetrical three-translational parallel mechanism, which includes three active branch chains, and each branch chain includes two parts: a driving arm and a driven arm. There are two types of branch chains of this kind of mechanism. One is that the main arm and the driven arm are both in the form of a single rod, and the two ends of the driven arm are respectively connected with the main arm and the moving platform through the Hooke hinge; The arm is a single rod, while the slave arm is a double rod, and the double rod slave arm forms a parallelogram. The two ends of each rod are respectively connected with the active arm and the dynamic platform through ball joints, and one end of the active arm has only one movement relative to the static platform. Or rotation degree of freedom, the other end is connected with one end of the follower arm through a ball joint, thereby limiting the three rotation degrees of freedom of the movable platform relative to the fixed frame. There are no standard parts for the hinge of this type of mechanism, the manufacturing cycle is long, and the installation is complicated. Chinese patent 200510015750 discloses a space three-translational parallel mechanism with a parallelogram branch chain structure containing steel wires. The mechanism is composed of a fixed frame, a moving platform, and three branch chains with the same structure that are arranged axisymmetrically and evenly between the fixed frame and the moving platform; the branch chains are fixed on the fixed frame The drive device, one end connected to the output end of the drive device, the other end of which is fixedly connected to the connecting block, and the far frame rod whose one end is hinged to the connecting block ball and the other end is hinged to the moving platform ball , Two steel wires parallel to the two steel wires are arranged symmetrically on both sides of the remote support rod, and the two ends of the steel wires are respectively hinged to the connecting block and the moving platform ball. The disadvantage of this type of mechanism is that since the steel wire is a flexible unit, its length also changes when the degree of tightness is different, resulting in changes in the attitude of the moving platform, making it difficult to guarantee the attitude accuracy of the moving platform.

Contents of the invention

The purpose of this utility model is to overcome the deficiencies in the above-mentioned prior art, to provide a three-level platform with a short manufacturing period, convenient installation, high posture accuracy of the dynamic platform, and large overall rigidity, which contains near-frame parallelograms and far-frame juxtaposed rods. Freedom robot mechanism.

In order to solve the above-mentioned technical problems, the basic concept of the present invention is: three uniformly distributed branch chains with identical structures ensure the accuracy of the pose of the robot mechanism, and the structural form of the near frame parallelogram and the far frame side-by-side rods in the branch chains Ensure that the whole has greater rigidity.

The utility model provides a three-translational degree of freedom robot mechanism containing parallelogram-far frame parallelograms, including a frame, a moving platform, and three branch chains with the same structure, and the three branch chains are jointly connected to the Frame and moving platform; one of the three branch chains with the same structure is composed of active arm, auxiliary active arm, double bush joint, first Hooke spherical hinge, far frame parallel rod, and second Hooke spherical hinge ; The double lining joint includes a first lining, a second lining, and a central axis of rotation, and the first lining and the second lining are respectively hinged with the central axis of rotation; the joint of the double lining is connected The active arm, the sub-active arm and the first Hooke spherical joint; one end of the active arm is connected through a planar slewing pair and a double bush joint, and the other end is connected to the output shaft of the driving device fixedly connected to the frame key connection; one end of the auxiliary active arm is connected to the joint of the double lining frame through a ball joint, and the other end is connected to the frame through a ball joint; Form a near-frame parallelogram structure; the Hooke ball joint is made up of a central cross shaft, a first plane slewing pair, a second plane slewing pair, a first ball hinge, and a second ball hinge; Two follower arms of equal length are formed; one end of the parallel bar of the far frame is fixedly connected to the first Hooke ball hinge, and the other end is fixedly connected to the second Hooke ball hinge; A Hooke spherical joint and double lining frame joints are connected by a plane revolving pair; the second Hooke spherical joint and the moving platform are connected by a plane revolving pair; the three branch chains are evenly arranged, and all have fixed The driving device on the frame is connected with the active arm.

The driving device adopts a servo motor-reducer structure.

The utility model is composed of the parallelogram of the near frame and the parallel rods of the far frame. The common constraint effect of the three branch chains uniformly distributed in space restricts the three degrees of freedom of the moving platform, so that the moving platform has only three translational freedoms relative to the frame. The degree ensures the stable attitude of the robot mechanism. The motion drive provided by the three sets of driving devices makes the robot mechanism with three translational degrees of freedom have definite motion and ensures the precise position of the mechanism. The rigidity of the single branch chain of the robot mechanism is high, and further, the parallel structure of the three branch chains ensures that the whole mechanism has greater rigidity.

The utility model has the following characteristics:

1. The structural form of the near-frame parallelogram and the far-frame parallel rods is used as the constraint to limit the degree of freedom of rotation;

2. The structural characteristics of the Hooke spherical joint make the center drift small and the angular range of motion is large. With the structure of the double-liner joint, the robot mechanism has a large working space;

3. The robot mechanism has precise pose and high rigidity;

4. The structure of the Hooke ball joint and the connection method with the parallel rods of the far frame can ensure that the two driven arms of the robot mechanism are evenly stressed, reducing the wear of the kinematic pair, thereby improving the life of the mechanism;

5. The Hooke ball hinge composed of general standard parts can fully realize the functions of the traditional Hooke hinge. In addition, standard ball hinges are used in many parts of the mechanism, which is convenient for shortening the manufacturing cycle and quick replacement of parts after use.

The utility model adopts the branch chain structure of the near frame parallelogram and the far frame parallel rods to limit the rotation freedom of the stop platform, and the structure form of the near frame parallelogram and the far frame parallel rods ensures that the whole has greater rigidity. The beneficial effect of the mechanism is that the attitude error caused by the elasticity of the steel wire is effectively avoided, the manufacture is simple, the installation and debugging are convenient, and the manufacturing cost of the mechanism is relatively low.

Description of drawings:

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a structural representation of one of branched chains of the same structural form of the present utility model;

Figure 3 is an enlarged view of part I of Figure 2;

Figure 4 is an enlarged view of Part II of Figure 2;

Fig. 5 is a structural schematic diagram of a double lining joint;

Figure 6 is a schematic diagram of the structure of the Hooke spherical hinge;

Figure 7 is a schematic diagram of the connection between the Hooke spherical hinge and the moving platform.

In the figure: 1: Rack, 2: Active arm, 3: Secondary active arm, 4: Double bushing joint, 5: Slave arm, 6: Moving platform, 7: Driving device, 8: The first Hooke ball joint , 9: The second Hooker ball joint, 4-1: The first bushing, 4-2: The second bushing, 4-3: The center shaft of the main arm rotation, 4-4: The center shaft of the slave arm rotation, 8 -1: central cross axis, 8-2: first plane rotary pair, 8-3: second plane rotary pair, 8-4: first ball hinge, 8-5: second ball hinge.

Detailed ways:

Below in conjunction with accompanying drawing, the utility model will be further described:

As shown in Figures 1 to 7, a robot mechanism with three translational degrees of freedom containing parallelograms near the frame and parallelograms on the far frame includes a frame 1 and a moving platform 6, which are evenly arranged between the frame 1 and the moving platform 6 Three branch chains with the same structure form connect the frame 1 and the moving platform 6, and the branch chains include a near-frame parallelogram and a far-frame parallel rod assembly structure, which can limit the three rotational degrees of freedom of the moving platform 6.

As shown in Figure 1 and Figure 2, one of the three branch chains with the same structure is composed of the active arm 2, the auxiliary active arm 3, the double bush joint 4, the first Hooke ball joint 8, and the far frame parallel rod 5. , The second Hooke spherical hinge 9 is formed. the

As shown in Fig. 5, the described double lining frame joint 4 is composed of the first lining frame 4-1, the second lining frame 4-2, the central axis of rotation of the active arm 4-3, and the central axis of rotation of the driven arm 4-4. Composition, the first bushing 4-1 and the second bushing 4-2 are respectively hinged to the central axis of rotation of the active arm 4-3 and the central axis of rotation of the driven arm 4-4. As shown in Figure 3, one end of the active arm 2 is connected to the active arm rotation central axis 4-3 of the double-row lining frame 4 through a plane rotary pair, the center of rotation of which is point B, and the other end is connected to the machine The output shaft of the driving device 7 on the frame 1 is keyed, and its center of rotation is point A; one end of the auxiliary main arm 3 is connected with the rotation center axis 4-4 of the auxiliary main arm of the double bush joint 4 through a ball joint , its center of rotation is point C, and the other end is connected to the frame 1 through a ball joint, and its center of rotation is point D; the structure and design ensure that the distance between A and B is equal to the distance between C and D, and the distance between A and D The distance is equal to the distance of B and C. In this way, the active arm 2, auxiliary active arm 3, and double lining joint 4 are connected by kinematic pairs to form a parallelogram structure in form, which can make the mechanism maintain The posture of the double bushing joint 4 remains unchanged.

The first Hooke spherical hinge 8 and the second Hooke spherical hinge 9 have the same structure, and for the present invention, they are named differently only because of their different positions in the branch chain. As shown in Figure 6, the first Hooke ball hinge 8 is composed of a central cross shaft 8-1, a first plane rotary pair 8-2, a second plane rotary pair 8-3, a first ball hinge 8-4, The second ball hinge 8-5 is formed. The parallel rod 5 of the far frame is composed of two follower arms 5 with equal lengths. The connection mode of the first Hooke ball hinge 8, the second Hooke ball hinge 9, and the far frame parallel rod 5 in the branch chain is as follows: as shown in Figure 4 and Figure 7, the far frame parallel rod 5 One end is affixed to the first Hooke ball hinge 8, and the other end is affixed to the second Hooke ball hinge 9; the first Hooke ball hinge 8 and the double bushing joint 4 rotate through the plane Auxiliary connection; the second Hooke spherical joint 9 and the moving platform 6 are connected through a plane revolving pair. Through this connection method, the Hooke ball hinge 8 , the Hooke ball hinge 9 , and the remote frame parallel rod 5 are combined to form a parallelogram structure, and the Hooke ball hinge can only rotate in two directions around the axis of the cross axis.

The three branch chains are evenly arranged, and are all connected to the active arm 2 by the driving device 7 .

The drive device 7 is fixedly connected to the frame 1, so that its output can provide a degree of freedom of movement or rotation for the moving platform 6 connected to it; The active arm 2 provides a rotational degree of freedom. To achieve the same purpose, a torque motor can also be used to provide a rotational degree of freedom for the active arm 2 connected thereto. In certain application conditions, a linear motor driving method may also be used to provide a degree of freedom of movement for the active arm 2 connected thereto. Of course, in actual implementation, any other structural form that can realize the same motion function can be used as the driving method.

Claims (2)

1. three-translational freedom robot mechanism that contains nearly frame parallelogram-frame parallel rod far away, it is characterized in that this robot mechanism comprises frame, moving platform, three side chains that version is identical, common described frame and the moving platform of connecting of described three side chains; One of side chain that described three versions are identical is made up of master arm, secondary master arm, two lining framves joint, the first Hooke ball pivot, frame parallel rod far away, the second Hooke ball pivot; Described pair of lining framves joint comprises the first lining frame, the second lining frame, rotary middle spindle, and it is hinged with rotary middle spindle respectively that the described first lining frame, second serves as a contrast frame; Described two lining framves joint connects described master arm, secondary master arm and the first Hooke ball pivot; Described master arm one end is connected by the secondary and two lining frame of plane rotation joint, and the other end is connected with the output axle key of the drive unit that is fixed on described frame; Described secondary master arm one end is connected with two lining framves joint by ball pivot, and the other end is connected with frame by ball pivot; Described master arm, secondary master arm, two lining framves joint form nearly frame parallelogram sturcutre by the connection of kinematic pair; Described Hooke ball pivot is made up of central cross axle, the first plane rotation pair, the second plane rotation pair, first spherical hinge, second spherical hinge; Described frame parallel rod far away is made up of the slave arm of two equal in length; Described frame parallel rod one end far away and the described first Hooke ball pivot are affixed, and the other end and the described second Hooke ball pivot are affixed; The described first Hooke ball pivot is connected by the plane revolute pair with two lining framves joint; The described second Hooke ball pivot is connected by the plane revolute pair with described moving platform; Described three side chains are evenly arranged, and are all had the drive unit that is fixed on the described frame to be connected with master arm.

2. a kind of three-translational freedom robot mechanism that contains nearly frame parallelogram-frame parallel rod far away according to claim 1, it is characterized in that: described drive unit adopts servomotor-reducer structure.

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