Two-branch-chain high-speed parallel manipulator with gear and rack structure

Abstract

The invention relates to a high-speed parallel manipulator with two branched chains provided with gear and rack structures, which comprises two bases and two branched chains, the bases are arranged in parallel, and the branched chains are arranged between the bases; the end, away from the base, of each branch chain is provided with a movable platform. The base is a U-shaped frame, a lead screw is arranged on the inner side of the base, and a first motor in transmission with the lead screw is arranged on the outer wall of the base. A movable plate is arranged on the outer wall of the lead screw, and a nut base matched with the lead screw is arranged on the side wall of the movable plate. Based on linkage of the branched chains, multi-degree-of-freedom displacement, including up-down, front-back, left-right and rotation directions, of the movable platform in a three-dimensional space can be achieved; the movable platform is small in size, convenient to install and high in rotation precision; through the structural configuration that the first motor and the coupler are matched with the second motor and the speed reducer, high-acceleration and high-acceleration displacement driving can be achieved, and therefore the dynamic performance of the mechanical arm is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-speed manipulators, and in particular to a high-speed parallel manipulator with a two-link belt gear-rack structure. Background Art

[0002] Due to the fact that the end of a high-speed parallel robot mechanism can achieve high speed and high acceleration, and can meet operations such as the handling of spatial objects, it has been widely used in high-speed and light-load handling operations on automated production lines in fields such as food and medicine, modern logistics, and electronic information.

[0003] The most famous of such robots is the spatial three-dimensional translational Delta robot invented by Clavel. Its end effector's three-dimensional translation is achieved through the driving of the outer rotating pair of the active arm and the parallelogram structure of the driven arm. The rotation of the end effector is achieved by adding a set of UPU links between the static and moving platforms. However, due to the limitation of the transmission chain structure of the added links, the angular accuracy is low and it is prone to wear during long-term operation.

[0004] In addition, the developed H4 manipulator. This manipulator consists of four symmetric moving links and a rotatable moving platform. The four moving links drive the moving platform, and through gear meshing or belt drive, etc., the rotation angle of the end effector is several times the relative displacement angle of the platforms.

[0005] Although it has three translational degrees of freedom and one rotational degree of freedom, due to the poor stability and large inertia of the moving platform during operation, its sorting operation accuracy is low. At the same time, due to the large mass and complex structure of the end moving components, it is also not conducive to improving the dynamic performance of the mechanism and reducing the cost of the mechanism. Summary of the Invention

[0006] Technical Problems to be Solved by the Invention Although the current manipulator has three translational degrees of freedom and one rotational degree of freedom, due to the poor stability and large inertia of the moving platform during operation, its sorting operation accuracy is low. At the same time, due to the large mass and complex structure of the end moving components, it is also not conducive to improving the dynamic performance of the mechanism and reducing the cost of the mechanism.

[0007] Technical Solutions for Solving the Technical Problems Other advantageous and to some extent creatively implemented embodiments and extended designs of the present invention are described in the following description.

[0008] A high-speed parallel manipulator with a two-link belt gear-rack structure, comprising a base and links. Both the base and the links are provided in two, the bases are arranged in parallel, and the links are arranged between the bases; A moving platform is provided at the end of each link away from the base; The base is set as a "U"-shaped frame, a lead screw is arranged inside it, and a first motor for driving the lead screw is arranged on the outer wall of the base; A moving plate is arranged on the outer wall of the lead screw, and a nut seat matching the lead screw is arranged on the side wall of the moving plate.

[0009] Preferably, the branch chain includes: Two elbow brackets, a transmission rod is arranged between the elbow brackets; The number of the transmission rods is set to two, and they are located at the upper and lower parts between the elbow brackets; A driving arm, one end of which is rotatably connected to the top end of the moving plate, and the other end is rotatably connected to the outer wall of the transmission rod above the elbow bracket; A second motor is installed on the outer wall of the moving plate, and its output end is in transmission connection with the driving arm; A first driven arm, one end of which is rotatably connected to the outer wall of the moving plate, and the other end is rotatably connected to the outer wall of the transmission rod below the elbow bracket; A second driven arm is rotatably connected to the outer wall of the transmission rod below the elbow bracket; A moving platform is installed at the free end of the second driven arm.

[0010] Preferably, the numbers of the driving arm, the first driven arm, and the second driven arm are all set to two, forming a symmetrical layout of double branch chains, canceling the inertial couple, reducing the end jitter, improving the motion smoothness, and using lightweight materials to centrally optimize the key arm rods to reduce the cost; In the vertical direction of the moving plate, the first driven arm is located below the driving arm; In the axial direction of the transmission rod, the second driven arm is located outside the first driven arm.

[0011] Preferably, the second motor and the driving arm are in transmission connection through a speed reducer to amplify the torque, reduce the inertia of the motor, and improve the response speed.

[0012] Preferably, the moving platform and the free end of the second driven arm are rotatably connected through a connecting rod.

[0013] Preferably, the moving platforms connected by the two branch chains are limited by a limiting frame; A limiting block is arranged at one end of the moving platform close to the limiting frame; A gear is arranged between the two moving platforms, and a matching transmission tooth is arranged on the side wall of the moving platform close to the gear.

[0014] Preferably, a pointer is arranged on the upper part of the limiting frame; The pointer and the gear are fixedly connected through a shaft penetrating the limiting frame.

[0015] Preferably, a suction cup is provided on the end face of the gear away from the pointer; A clamping jaw is provided on the end face of the gear away from the pointer; An electromagnet is provided on the end face of the gear away from the pointer.

[0016] Preferably, the first motor and the lead screw are driven by a coupling.

[0017] Preferably, a guide rod penetrating the moving plate is provided inside the base and below the lead screw, and a limiting hole matching the guide rod is provided on the moving plate.

[0018] Effects of the Invention It can realize the multi-degree-of-freedom displacement of the moving platform in three-dimensional space, including up and down, front and back, left and right, and rotational directions; The moving platform is small in size, convenient to install, and has high rotation accuracy; 3. Through the structural configuration of the first motor, coupling, second motor, and reducer, high-acceleration and high-acceleration displacement driving can be achieved, thereby improving the dynamic performance of the manipulator. Description of the Drawings

[0019] The embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings: Figure 1 is the first structural view of the present invention; Figure 2 is the second structural view of the present invention; Figure 3 is the top view of the present invention; Figure 4 is the first structural view of one set of the chain links and the base included in the present invention; Figure 5 is the second structural view of one set of the chain links and the base included in the present invention; Figure 6 is the cross-sectional view of the moving platform included in the present invention; Figure 7 is the first side view of the present invention; Figure 8 is the first working state schematic diagram of the present invention; Figure 9 is the second side view of the present invention; Figure 10 is the first working state schematic diagram of the present invention; Figure 11 is the bottom view of the present invention.

[0020] Description of the Reference Numerals 1. Base; 101. Guide rod; 2. First motor; 201. Lead screw; 202. Moving plate; 3. Second motor; 301. Driving arm; 302. Elbow bracket; 303. First driven arm; 304. Second driven arm; 305. Transmission rod; 4. Link; 4-1. Moving platform; 401. Transmission gear; 402. Gear; 5. Suction cup; 501. Pointer; 6. Limit frame; 6-1. Limit block. Detailed implementation mode

[0021] Hereinafter, a high-speed parallel manipulator with a two-link belt gear-rack structure, which is an embodiment of the present invention, will be described with reference to the accompanying drawings.

[0022] Please refer to Figures 1 - 11 As shown, a high-speed parallel manipulator with a two-link belt gear 402-rack structure includes a base 1 and a link. The number of the base 1 and the link is set to two, and a moving platform 4-1 is provided at the end of each link away from the base 1; Specifically, the two bases 1 are symmetrically arranged, and the links are arranged between the bases 1; The base 1 is set as a "U"-shaped frame, and a first motor 2 is provided on the outer wall of the base 1; A lead screw 201 is rotatably installed inside the base 1; Specifically, the lead screw 201 is linked with the output end of the first motor 2 through a coupling; A moving plate 202 is provided outside the lead screw 201; Specifically, a through hole is provided through the moving plate 202, and a nut seat is provided on the side wall of the moving plate 202 corresponding to the through hole, and the nut seat matches the lead screw 201; A guide rod 101 is provided inside the base 1 and below the lead screw 201; Specifically, the guide rod 101 is parallel to the lead screw 201, and a limit hole matching the guide rod 101 is provided through the moving plate 202; That is, in the use state, the guide rod 101 limits the rotation of the moving plate 202, and the transmission is realized through the lead screw 201 at the output end of the first motor 2 and the nut seat on the outer wall of the moving plate 202, and the moving plate 202 reciprocates axially along the axis of the lead screw 201 inside the base 1; Regarding the link, it includes: Elbow brackets 302, the number of which is two, for carrying the rods included in the link; Transmission rods 305, the number of which is two, and are rotatably installed between the two elbow brackets 302; Specifically, the two transmission rods 305 are respectively located at the upper and lower parts inside the two elbow brackets 302; A driving arm 301, one end of which is rotatably connected to the top end of the moving plate 202, and the other end is rotatably connected to the outer wall of the transmission rod 305; Specifically, the number of active arms 301 is set to at least two; The second motor 3 is installed at the top end of the outer wall of the moving plate 202 and is arranged corresponding to the active arm 301; Specifically, the second motor 3 is driven by a speed reducer to the active arm 301; One end of the first driven arm 303 is rotatably connected to the outer wall of the moving plate 202, and the other end is rotatably connected to the outer wall of the transmission rod 305 below the elbow bracket 302; That is, in the use state, the active arm 301, the first driven arm 303, the transmission rod 305, the moving plate 202 and the elbow bracket 302 form a parallelogram linkage group, which can transmit the output power of the second motor 3; The second driven arm 304 is rotatably connected to the outer wall of the transmission rod 305 below the elbow bracket 302, and the number of the second driven arms is 2 and they are located on both sides of the first driven arm 303; The moving platform 4-1 is installed between the free ends of the two second driven arms 304; Specifically, the moving platform 4-1 is rotatably connected to the second driven arm 304 through a connecting rod 4; The moving platforms 4-1 arranged at the free ends of the two groups of link chains are slidably limited by a limiting frame 6; A gear 402 is arranged between the two moving platforms 4-1; The side walls of the two moving platforms 4-1 close to the gear 402 are provided with transmission teeth 401 matching the gear 402; One side of the two moving platforms 4-1 close to the limiting frame 6 is provided with a limiting block 6-1 matching the limiting frame 6; Specifically, the two moving platforms 4-1 are relatively slidably limited by the limiting frame 6 and the limiting block 6-1; A pointer 501 is arranged on the upper part of the limiting frame 6; Specifically, the pointer 501 and the gear 402 are fixedly connected by a rotating shaft penetrating the limiting frame 6; A suction cup 5 is arranged on the end face of the gear 402 far from the pointer 501; Specifically, the suction cup 5 is used as a grasping mechanism, and the staff can replace it with a gripper or an electromagnet according to the use scenario.

[0023] Normal use state The staff installs the two groups of bases 1, the guide rods 101, the first motor 2, the lead screws 201, and the moving plates 202 in parallel, and installs the link chains, the moving platforms 4-1 and the gear 402. Among them, the moving platforms 4-1 and the gear 402 are limited by the limiting frame 6 and the limiting block 6-1; In the use state: The above structure has 2 driving joints: First, the transmission is carried out through the first motor 2, the coupling, the lead screw 201, the moving plate 202, and the nut seat set on the moving plate 202. The lead screw 201 and the nut drive away, driving the moving plate 202 to move back and forth along the axis of the lead screw 201, reducing the elastic deformation in the transmission chain, supporting high acceleration movement, and improving dynamics. The lead screw drive directly converts the rotational motion into linear motion, reducing the number of parts and assembly complexity, and reducing the manufacturing cost. Second, the two sets of branch chains are rigidly constrained by the limit frame 6, the limit block 6-1, the moving platform 4-1, the connecting rod 4 and the gear 402 to ensure that the moving platform does not deviate or vibrate during the movement, thereby improving stability. The active arm 301 is driven to rotate by the second motor 3 and the reducer, and then the driven arm is driven to perform two-dimensional translation in the normal plane of the screw 201. The movement in the X-axis direction is realized by the parallelogram mechanism of the branch chain, and the movement in the Z-axis direction is indirectly realized by the gear rack structure, which reduces the cost of motor and servo control. The two are independently controllable, reduce motion coupling, and improve the dynamic performance of the mechanism.

[0024] Thirdly, when the movement directions of the above-mentioned "one" step realized by the two first motors 2 are opposite, the two sets of branch chains are displaced along the direction of the line parallel to the axis of the lead screw 201, and the gear 402 rack structure composed of the transmission teeth 401 and the gear 402 located on the side wall of the moving platform 4-1 is highly rigidly engaged and directly drives the suction cup 5 to rotate, thereby reducing motion coupling, simplifying the mechanical structure, eliminating the need for additional rotating branch chains, and reducing manufacturing and maintenance costs.

[0025] Combining the above three steps, multi-degree-of-freedom displacement of the suction cup 5 can be achieved, including up and down (realized by the second motor 3 driving the two groups of branch chains to perform the same displacement stroke), left and right (realized by the first motor 2 driving the two moving plates 202 to perform synchronous displacement), front and back (realized by the second motor 3 driving the two groups of branch chains to perform different displacement strokes), and rotation direction (realized by the first motor 2 driving the two moving plates 202 to perform asynchronous displacement and cooperating with the rack structure of the gear 402).

[0026] Compared with the prior art, this application has the following characteristics: The moving platform 4-1 can be moved in multiple degrees of freedom in three-dimensional space, including up and down, front and back, left and right, and rotation directions; The moving platform 4-1 is small in size, easy to install, and has high rotation accuracy; Through the structural configuration of the first motor 2, the coupling, the second motor 3, and the reducer, high acceleration and high acceleration displacement drive can be achieved, thereby improving the dynamic performance of the manipulator.

[0027] Two chains are arranged in parallel and are connected to an independent moving platform 4-1. Coordinated movement is achieved through the limit frame 6 and the gear 402 to improve movement accuracy.

[0028] The present invention is not limited to the embodiments, and various modifications can be implemented as long as they do not violate its gist.

Claims

1. A high-speed parallel manipulator with a two-branch belt and gear-rack structure, comprising a base and a branch chain, characterized in that: The base and the branch chains are both provided in two numbers. The bases are arranged in parallel, and the branch chains are arranged between the bases; A moving platform is provided at the end of each branch chain away from the base; The base is arranged as a "U"-shaped frame, and a lead screw is arranged inside it. A first motor for driving the lead screw is arranged on the outer wall of the base; A moving plate is arranged on the outer wall of the lead screw, and a nut seat matching the lead screw is arranged on the side wall of the moving plate.

2. The high-speed parallel manipulator with two-chain-belt gear-rack structure according to claim 1, wherein: The branch chain includes: Two elbow brackets, and a transmission rod is arranged between the elbow brackets; The number of the transmission rods is two, and they are located at the upper and lower parts between the elbow brackets; A driving arm, one end of which is rotatably connected to the top end of the moving plate, and the other end is rotatably connected to the outer wall of the transmission rod above the elbow bracket; A second motor is installed on the outer wall of the moving plate, and its output end is in transmission with the driving arm; A first driven arm, one end of which is rotatably connected to the outer wall of the moving plate, and the other end is rotatably connected to the outer wall of the transmission rod below the elbow bracket; A second driven arm is rotatably connected to the outer wall of the transmission rod below the elbow bracket; The moving platform is installed at the free end of the second driven arm.

3. The high-speed parallel manipulator with a two-branch belt gear-rack structure according to claim 2, characterized in that: The numbers of the driving arm, the first driven arm, and the second driven arm are all two; In the vertical direction of the moving plate, the first driven arm is located below the driving arm; In the axial direction of the transmission rod, the second driven arm is located outside the first driven arm.

4. The high-speed parallel manipulator with a two-link belt gear-rack structure according to claim 3, wherein: The second motor and the driving arm are in transmission through a speed reducer.

5. The high-speed parallel manipulator with two-chain belt gear-rack structure according to claim 2, characterized in that: The moving platform and the free end of the second driven arm are rotatably connected through a connecting rod.

6. The high-speed parallel manipulator with two-chain belt gear-rack structure according to claim 2, characterized in that: The moving platforms connected by the two branch chains are limited by a limiting frame; A limiting block is arranged at one end of the moving platform close to the limiting frame; A gear is arranged between the two moving platforms, and a matching transmission tooth is arranged on the side wall of the moving platform close to the gear.

7. The high-speed parallel manipulator with a two-branch belt gear-rack structure according to claim 6, characterized in that: A pointer is arranged on the upper part of the limiting frame; The pointer and the gear are fixedly connected by a shaft passing through the limiting frame.

8. The high-speed parallel manipulator with two-chain belt gear-rack structure according to claim 7, characterized in that: A suction cup is arranged on the end face of the gear away from the pointer; A clamping jaw is arranged on the end face of the gear away from the pointer; An electromagnet is arranged on the end face of the gear away from the pointer.

9. The high-speed parallel manipulator with a two-branch belt gear-rack structure according to claim 1, wherein: The first motor and the lead screw are in transmission through a coupling.

10. The two-chain-belt gear-rack structure high-speed parallel manipulator according to claim 9, characterized in that: A guide rod passing through the moving plate is arranged inside the base and below the lead screw, and a limiting hole matching the guide rod is arranged on the moving plate.

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