A robot rotary joint with a buffering structure

Abstract

The utility model discloses a kind of robot rotary joints with buffer structure belong to robot joint technical field, for the problem that existing robot rotary joint for machine tool parts conveying is mostly complex multi-joint structure, high cost. The joint includes pedestal, the top of the pedestal is provided with rectangular chute, rack is slidably arranged in the rectangular chute, the side of the pedestal is fixed with mounting plate I by bolt, the inner wall of the mounting plate I is rotatably installed with transmission gear by bearing, the transmission gear is engaged with rack, the other side of the transmission gear is fixedly provided with L type connecting frame, rotatable rotating rod is rotatably installed on the L type connecting frame by bearing, the top of the rotating rod is fixedly installed with pneumatic gripper. The utility model can complete translation and rotation compound motion by single cylinder, which is beneficial to reduce precision joint components, thereby reducing manufacturing cost.

Description

Technical Field

[0001] This utility model relates to the field of robot joint technology, and in particular to a robot rotary joint with a buffer structure. Background Technology

[0002] When transferring and unloading parts between automatic machine tools, it is often necessary to use the robot's rotating joints to drive the grippers to complete the gripping and handling of parts.

[0003] Many existing operations of this type use the rotary joint structure of multi-joint robots. This type of structure contains a large number of precision joint components and is complex, resulting in high manufacturing costs. Furthermore, the rotary joints of multi-joint robots usually require multiple drive components to control the movement of different joints, which can easily lead to the accumulation of backlash during transmission.

[0004] To address the aforementioned problems, this utility model proposes a robot rotary joint with a buffer structure. Utility Model Content

[0005] This invention provides a robot rotary joint with a buffer structure, which solves the shortcomings of existing robot rotary joints used for transporting machine tool parts, which are mostly complex multi-joint structures and have high costs.

[0006] This utility model provides the following technical solution: A robot rotary joint with a buffer structure includes a base, a rectangular groove on the top of the base, a rack slidably disposed within the rectangular groove, a mounting plate I fixed to one side of the base by bolts, a transmission gear rotatably mounted on the inner wall of the mounting plate I via bearings, the transmission gear meshing with the rack, an L-shaped connecting frame fixed to the other side of the transmission gear, a rotatable rotating rod rotatably mounted on the L-shaped connecting frame via bearings, and a pneumatic gripper fixedly mounted at the top of the rotating rod.

[0007] Preferably, an L-shaped mounting bracket is fixed to one side of the base by bolts, and a cylinder for driving the rack is fixedly installed on the outer wall of the L-shaped mounting bracket. The output shaft of the cylinder passes through the inner wall of the L-shaped mounting bracket and is fixedly connected to one end of the rack.

[0008] Preferably, a mounting plate II is fixed to one side of the base by bolts, a bevel gear I is fixedly installed on the outer wall of the mounting plate II, and the bottom end of the rotating rod passes through the inner wall of the L-shaped connecting frame and is fixedly installed with a bevel gear II, wherein the bevel gear I and the bevel gear II mesh.

[0009] Preferably, the number of teeth of bevel gear I and bevel gear II is the same.

[0010] Preferably, a rectangular card holder is fixedly provided on the top of the base, and a buffer pad for supporting the side wall of the L-shaped connecting frame after rotation is snapped into the cavity in the center of the rectangular card holder.

[0011] Preferably, a reinforcing plate is welded and fixed to the bottom of the base, and each of the four corners of the reinforcing plate is provided with a strip-shaped mounting hole for bolts to pass through.

[0012] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the present invention.

[0013] The working principle and usage process of this technical solution are as follows: In use, the cylinder fixed to the L-shaped mounting bracket is activated. The cylinder output shaft extends or retracts, causing the rack fixedly connected to it to slide horizontally in a rectangular groove on the top of the base. The direction of the rack's movement is determined by the extension and retraction direction of the cylinder output shaft. The rack then drives the L-shaped connecting bracket to revolve around the transmission gear. The rack meshes with the transmission gear on mounting plate I, converting the rack's linear motion into the rotational motion of the transmission gear. Because the L-shaped connecting bracket is fixedly connected to the transmission gear, the rotation of the transmission gear causes the L-shaped connecting bracket to revolve around the axis of the transmission gear. The body rotates around the center of the transmission gear, and then drives the rotating rod to rotate through the meshing transmission of bevel gears. The bottom end of the rotating rod on the L-shaped connecting frame is fixed with bevel gear II, and bevel gear II is always meshed with bevel gear I fixed on the mounting plate II on the base. Since the position of bevel gear I is fixed, when the L-shaped connecting frame revolves, bevel gear II will roll around the axis of bevel gear I. Through the meshing relationship of bevel gears, the rotating rod is driven to rotate around its own axis. The pneumatic gripper fixed at the top of the rotating rod moves synchronously with the rotating rod, and finally realizes the coordinated action of the revolution around the axis of the transmission gear and the rotation around the axis of the rotating rod. The pneumatic gripper opens and closes through an independent air circuit or solenoid valve to grip, transport, or load / unload parts. Through linear drive of the cylinder and angular coupling of bevel gear transmission, the pneumatic gripper can achieve a composite motion of translation and rotation without the need for multiple joints. Since bevel gear I and bevel gear II have the same number of teeth, the gripper's rotation angle and revolution angle are equal, which helps to ensure a stable and controllable motion trajectory. For example, the posture of the parts can be precisely adjusted during transport. When the L-shaped connecting frame revolves to a specific position, such as the end point of loading / unloading the parts, its side wall will contact the buffer pad in the rectangular card holder at the top of the base. The buffer pad absorbs the impact energy through its own deformation, avoiding rigid collision damage to the parts.

[0014] This utility model has the following beneficial effects: 1. This utility model does not require a complex multi-joint robot structure. It can achieve the coupling mechanism of gear rotation and revolution through a simple transmission combination of cylinder, rack and pinion and gear (transmission gear and bevel gear). It can achieve multi-degree-of-freedom motion with only a single cylinder drive, replacing the complex serial structure of traditional multi-joint robots. This helps to reduce the number of precision joint components, thereby reducing the equipment manufacturing cost. 2. In this utility model, the meshing transmission of rack and pinion and transmission gear achieves revolution, and the meshing transmission of bevel gear I (fixed) and bevel gear II (follower) achieves rotation. The transmission gap is small, and the number of teeth of bevel gear I and II is the same, which helps to ensure that the rotation angle of the gripper is completely matched with the revolution angle, thereby avoiding posture deviation caused by transmission error. 3. The buffer pad inside the rectangular card holder in this utility model can directly bear the impact when the L-shaped connecting frame rotates, avoiding wear or damage caused by rigid collision, which helps to extend the component replacement cycle. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram provided for an embodiment of the present utility model; Figure 2 This is a schematic diagram of another structural perspective provided for an embodiment of the present utility model; Figure 3 This is a schematic diagram of the rotating rod in a horizontal position according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the shell structure provided in an embodiment of the present utility model; Figure 5 This utility model Figure 4 Enlarged view of part A in the image.

[0016] Reference numerals: 1. Base; 2. Reinforcing plate; 3. Strip mounting hole; 4. Rack; 5. Rectangular slide; 6. Mounting plate I; 7. Transmission gear; 8. L-shaped mounting bracket; 9. Cylinder; 10. L-shaped connecting bracket; 11. Rotating rod; 12. Pneumatic gripper; 13. Mounting plate II; 14. Bevel gear I; 15. Bevel gear II; 16. Rectangular bracket; 17. Buffer pad. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0018] In the description of this utility model, it should be understood that the terms "opening", "upper", "middle", "length", "inner", etc., which indicate orientation or positional relationship, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0019] To keep the following description of the embodiments of this utility model clear and concise, detailed descriptions of known functions and known components are omitted.

[0020] In Example 1: Please refer to Figures 1-5 A robot rotary joint with a buffer structure includes a base 1, a rectangular groove 5 machined on the top of the base 1, a rack 4 slidably mounted inside the rectangular groove 5, the length of the rack 4 being less than the length of the rectangular groove 5, a mounting plate I6 fixed to one side of the base 1 by bolts, the mounting plate I6 being arranged vertically, a transmission gear 7 being rotatably mounted on its inner wall by a deep groove ball bearing, the teeth of the transmission gear 7 being fully meshed with the teeth of the rack 4, the meshing clearance being controlled within 0.02mm, ensuring that the rack 4 can drive the transmission gear 7 to rotate stably when it moves, avoiding transmission slippage or jamming.

[0021] On the other side of the transmission gear 7, an L-shaped connecting frame 10 is fixedly mounted via a flat key. The horizontal section of the L-shaped connecting frame 10 fits against the end face of the transmission gear 7 and is further reinforced with bolts to ensure that the L-shaped connecting frame 10 can move synchronously with the rotation of the transmission gear 7. A rotating rod 11 is rotatably mounted on the vertical section of the L-shaped connecting frame 10 via a thrust ball bearing. The axis of the rotating rod 11 is perpendicular to the vertical section of the L-shaped connecting frame 10, and the rotating rod 11 can rotate freely around its own axis with low friction during rotation. A pneumatic gripper 12 is fixedly mounted on the top of the rotating rod 11 via a thread. Its opening and closing action is controlled by an independent air circuit and a solenoid valve. One end of the air circuit is connected to an external air source, and the other end is connected to the air inlet of the pneumatic gripper 12. The solenoid valve is installed on the air circuit pipeline and controls the air circuit opening and closing via an electrical signal to realize the opening and closing of the pneumatic gripper 12. The pneumatic gripper 12 has two symmetrical drive chambers, a piston push rod, and two sets of grippers inside. The two sets of grippers are respectively connected to the opposite drive chamber. The piston push rod is hinged, and the drive chamber has independent air inlets and outlets at both ends. It is connected to an external air source and a solenoid valve through an air pipe. The solenoid valve controls the opening and closing of the air path and switches through an electrical signal. When a part needs to be gripped, the solenoid valve receives the control signal and introduces compressed air from the external air source into the drive chamber near the closing direction of the gripper 12. The compressed air pushes the piston in the drive chamber to move in the closing direction of the gripper. The piston drives the piston push rod to move synchronously. The piston push rod pulls the two sets of grippers closer together through the hinge structure until the grippers are in contact with the surface of the part. When a part needs to be released, the solenoid valve switches the air path and introduces compressed air into the drive chamber near the opening direction of the gripper 12. At the same time, the gas in the drive chamber in the closing direction is discharged through the outlet. The compressed air pushes the piston to move in the opening direction of the gripper. The piston drives the piston push rod to move in the opposite direction. The piston push rod pushes the two sets of grippers to separate to both sides, completing the release of the part.

[0022] One side of the base 1 is also fixed with an L-shaped mounting bracket 8 by bolts. The cylinder 9 is fixedly mounted on the outer wall of the L-shaped mounting bracket 8 by bolts. The model of the cylinder 9 is selected according to the required driving force. The output shaft axis of the cylinder 9 is consistent with the axis of the rack 4. After the output shaft of the cylinder 9 passes through the inner wall of the L-shaped mounting bracket 8, it is fixedly connected to one end of the rack 4 by a coupling. The coupling adopts an elastic coupling, which can compensate for the coaxiality error between the cylinder output shaft and the rack 4, ensuring that when the cylinder 9 is started, the extension or retraction of the output shaft can directly drive the rack 4 to slide horizontally in the rectangular slide groove 5.

[0023] Mounting plate II13 is fixed to the other side of base 1 by bolts. Mounting plate II13 and mounting plate I6 are located on different sides of base 1. Bevel gear I14 is fixed to the outer wall of mounting plate II13 by set screws. The position of bevel gear I14 remains fixed and does not move with other parts. After the bottom end of rotating rod 11 passes through the inner wall of L-shaped connecting frame 10, bevel gear II15 is fixed to it by flat key. The teeth of bevel gear II15 are fully meshed with the teeth of bevel gear I14. The number of teeth of bevel gear I14 and bevel gear II15 is the same, both with 20 teeth, to ensure that the rotation angle and revolution angle of the two are equal when they are transmitting, so as to achieve precise matching of motion angle.

[0024] The top of the base 1 is near the movement trajectory of the L-shaped connecting frame 10. A rectangular bracket 16 is fixedly mounted on it by bolts. The height of the rectangular bracket 16 matches the height of the side wall of the L-shaped connecting frame 10. A buffer pad 17 is fitted into the cavity in the center of the rectangular bracket 16. The buffer pad 17 is made of polyurethane material with a Shore hardness of 50D. It has good elasticity and wear resistance. When the L-shaped connecting frame 10 rotates to a specific position, its side wall can fully contact the buffer pad 17.

[0025] When using this robot's rotary joint for automated parts transport and loading / unloading between machine tools, first connect the external air and power sources. Set the stroke of cylinder 9 and the opening / closing time of pneumatic gripper 12 via the control panel. After starting the equipment, first control the pneumatic gripper 12 to open via the solenoid valve. At this time, the pneumatic gripper 12 is in a ready-to-grab state. Then, start cylinder 9. The output shaft of cylinder 9 extends or retracts according to the set stroke, driving rack 4 to slide horizontally within rectangular slide groove 5. When rack 4 slides, its teeth drive the meshing transmission gear 7 to rotate. During the rotation of transmission gear 7, it drives the L-shaped connecting frame 10 fixed on it to revolve around the axis of transmission gear 7. The revolution trajectory of the L-shaped connecting frame 10 is circular, and the revolution radius is determined by the radius of the L-shaped connecting frame 10. The length determines that when the L-shaped connecting frame 10 revolves, the rotating rod 11 driven by it moves synchronously. The bevel gear II 15 at the bottom of the rotating rod 11 moves around the axis of the transmission gear 7 together with the rotating rod 11. At the same time, since the bevel gear II 15 is meshed with the fixed bevel gear I 14, the bevel gear II 15 will rotate around its own axis during the movement around the axis of the transmission gear 7. In turn, it will drive the rotating rod 11 to rotate around its own axis through the flat key. The pneumatic gripper 12 at the top of the rotating rod 11 moves synchronously with the rotating rod 11. Finally, the combined motion of revolving around the axis of the transmission gear 7 and rotating around the axis of the rotating rod 11 is realized. The trajectory of the combined motion is adjusted according to the stroke of the cylinder 9 and the length of the L-shaped connecting frame 10, which can cover the loading and unloading stations of the automatic machine tool. When the pneumatic gripper 12 moves to the position of the part to be gripped, the solenoid valve controls the pneumatic gripper 12 to close, and the gripper is in contact with the surface of the part. The part is clamped by the set clamping force. The clamping force is controlled by adjusting the air pressure to avoid the part being damaged by excessive clamping force or falling off due to insufficient clamping force. Then the cylinder 9 continues to drive, driving the rack 4 to move, and then the pneumatic gripper 12 carries the part to the workstation of the target machine tool through the transmission system. When the L-shaped connecting frame 10 revolves to the position corresponding to the target workstation, that is, the end point of part loading and unloading, the side wall of the L-shaped connecting frame 10 contacts the buffer pad 17 in the rectangular clamp 16. The buffer pad 17 deforms after being pressured by the L-shaped connecting frame 10. During the deformation process, it absorbs the impact energy and avoids the L-shaped connecting frame 10 from rigidly colliding with other fixed parts. At this time, the solenoid valve controls the pneumatic gripper 12 to open and place the part on the tooling fixture of the target machine tool to complete the part loading and unloading operation. After the loading and unloading operation is completed, the cylinder 9 drives the output shaft to move in the opposite direction, which drives the rack 4 to reset. The rack 4 drives the transmission gear 7 to rotate in the opposite direction, which in turn drives the L-shaped connecting frame 10, the rotating rod 11 and the pneumatic gripper 12 back to their initial positions, ready for the next part gripping and handling operation. During the entire operation, the movement rhythm of each component is coordinated by the PLC control system to ensure that the opening and closing of the pneumatic gripper 12 and the extension and retraction of the cylinder 9 match the processing rhythm of the machine tool, so as to realize continuous automated operation. In daily use, it is necessary to regularly add grease to the output shaft of the cylinder 9 and the bearing parts of the rotating rod 11. Lithium-based grease is used to ensure smooth movement of the components.

[0026] This application can be used for robot rotary joints, or for other fields applicable to this application.

[0027] In Example 2: A robot rotary joint with a buffer structure is used in the field of robot joints. Please refer to Figure 1 The base 1 is welded to the bottom of the reinforcing plate 2. The four corners of the reinforcing plate 2 are machined with strip-shaped mounting holes 3 for bolts to pass through. During actual installation, the position of the bolts in the strip-shaped mounting holes 3 can be adjusted to adapt to the installation spacing of various models of automatic machine tools.

[0028] However, as is well known to those skilled in the art, the working principles and wiring methods of cylinder 9 and pneumatic gripper 12 are conventional means or common knowledge, and will not be elaborated here. Those skilled in the art can make any selections according to their needs or convenience.

[0029] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0030] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. In the absence of conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A robot rotary joint with a buffer structure, characterized in that, The base (1) includes a base (1), a rectangular groove (5) is provided on the top of the base (1), a rack (4) is slidably arranged in the rectangular groove (5), a mounting plate I (6) is fixed to one side of the base (1) by bolts, a transmission gear (7) is rotatably mounted on the inner wall of the mounting plate I (6) by bearings, the transmission gear (7) meshes with the rack (4), an L-shaped connecting frame (10) is fixedly arranged on the other side of the transmission gear (7), a rotatable rotating rod (11) is rotatably mounted on the L-shaped connecting frame (10) by bearings, and a pneumatic gripper (12) is fixedly mounted on the top of the rotating rod (11).

2. A robot rotary joint with a buffer structure according to claim 1, characterized in that, An L-shaped mounting bracket (8) is fixed to one side of the base (1) by bolts. A cylinder (9) for driving the rack (4) to move is fixedly installed on the outer wall of the L-shaped mounting bracket (8). The output shaft of the cylinder (9) passes through the inner wall of the L-shaped mounting bracket (8) and is fixedly connected to one end of the rack (4).

3. A robot rotary joint with a buffer structure according to claim 1, characterized in that, One side of the base (1) is fixed with a mounting plate II (13) by bolts. A bevel gear I (14) is fixed on the outer wall of the mounting plate II (13). The bottom end of the rotating rod (11) passes through the inner wall of the L-shaped connecting frame (10) and is fixed with a bevel gear II (15). The bevel gear I (14) and the bevel gear II (15) mesh.

4. A robot rotary joint with a buffer structure according to claim 3, characterized in that, The number of teeth of bevel gear I (14) and bevel gear II (15) is the same.

5. A robot rotary joint with a buffer structure according to claim 1, characterized in that, A rectangular card holder (16) is fixedly installed on the top of the base (1), and a buffer pad (17) for bearing the side wall of the L-shaped connecting frame (10) after rotation is snapped into the cavity in the center of the rectangular card holder (16).

6. A robot rotary joint with a buffer structure according to claim 1, characterized in that, The base (1) is welded and fixed to the bottom of a reinforcing plate (2), and each of the four corners of the reinforcing plate (2) is provided with a strip-shaped mounting hole (3) for bolts to pass through.

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