Heavy-load robot joint structure

Abstract

A heavy-load robot joint structure, comprising a base (1), a screw hole (11), a rotary seat (12), a mounting frame (13), an upper arm (14), a lower arm (15) and first spring balance cylinders (16), wherein the screw hole (11) is provided in the surface of the base (1); the rotary seat (12) is movably mounted on the top of the base (1); the mounting frame (13) is fixedly mounted on the upper surface of the rotary seat (12); the upper arm (14) is movably mounted on the inner side of the mounting frame (13); the lower arm (15) is movably mounted on the upper arm (14), and a robotic gripper is mounted at an outward extending end of the lower arm; and two first spring balance cylinders (16) are provided. In the heavy-load robot joint structure, a second spring balance cylinder (26) can move with the lower arm (15) by means of a following assembly, thereby reducing the extension stroke of the second spring balance cylinder (26) caused by the lower arm (15), preventing a spring in the second spring balance cylinder (26) from being excessively stretched, and also reducing a driving torque. When the lower arm (15) grips and lifts a workpiece, the center of gravity of a robot can also be adjusted by means of a counterweight assembly.

Description

A joint structure for a high-load robot Technical Field

[0001] This invention relates to the field of robotics, specifically to a joint structure for a high-load robot. Background Technology

[0002] The robotic arm is the earliest industrial robot and also the earliest modern robot. It can mimic certain movements of the human hand and arm to grasp, move objects or operate tools according to a fixed program. In order to reduce the driving torque of the robot and increase its motion balance, balancing devices are often set at the joints of the robot's upper arm and forearm, thereby reducing the load on the robot during use and improving its balance. Among the existing balancing technologies, mass balancing, spring balancing, pneumatic or hydraulic balancing methods are commonly used.

[0003] One method is the spring balancing method, which uses stretched or compressed springs to balance the robot arm. When the robot is not grasping an object, the spring stretches to maintain the robot arm's balance. When the robot grasps an object, the spring continues to stretch to maintain the robot's balance, thereby reducing or offsetting the load generated by the robot grasping the object. However, the elastic force of the spring is uncontrollable. Within the elastic limit, the elastic force of the spring is proportional to the amount of spring elongation. Once the elastic limit is exceeded, it will lead to spring fatigue, damage to the spring, and thus affect the robot's balancing effect and reduce its operational stability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-load robot joint structure that solves the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-load robot joint structure, comprising a base, screw holes, a rotating base, a mounting frame, a large arm, a small arm, and a first spring balance cylinder. The screw holes are located on the surface of the base. The rotating base is movably mounted on the top of the base. The mounting frame is fixedly mounted on the upper surface of the rotating base. The large arm is movably mounted inside the mounting frame. The small arm is movably mounted on the large arm, and a robotic claw is mounted on one of its outwardly extending ends. There are two first spring balance cylinders located on both sides of the large arm. A first rotating shaft is fixedly mounted on one side of the top of the connecting rod of the first spring balance cylinder. The first rotating shaft is movably mounted to the large arm. The bottom of the first spring balance cylinder is movably mounted to the mounting frame. A following component is provided on the rotating base. The following component includes a servo motor, and the servo motor is fixedly mounted on the bottom of the rotating base.

[0006] A lead screw is fixedly installed on the output shaft of the servo motor. A screw sleeve is helically connected to the outer surface of the lead screw. A slider is fixedly installed on both sides of the screw sleeve. A slide is movably installed on the outer surface of the slider. The slide is fixedly connected to the rotary seat.

[0007] A counterweight is fixedly installed on one side of the screw sleeve. A second spring balance cylinder is movably connected to the upper surface of the counterweight. A hydraulic rod is installed inside the second spring balance cylinder. A connector is movably installed on the output shaft of the hydraulic rod. The end of the connector away from the hydraulic rod is fixedly connected to the forearm.

[0008] The rotary table is equipped with a load balancing component, which is used to improve the robot's load-bearing capacity.

[0009] Optionally, the load balancing assembly includes a fixing frame, and there are two fixing frames, which are respectively located on both sides of the boom. One end of the fixing frame is fixedly connected to the upper surface of the rotatable seat, and the other end is fixedly connected to a running rail.

[0010] A first balance spring is fixedly connected to one end of the inner cavity of the track, and a power block is fixedly connected to the other end of the first balance spring. The power block is movably installed in the inner cavity of the track. An electric push rod is fixedly connected to the top of the first spring balance cylinder connecting rod on the side away from the first rotating shaft. The output shaft of the electric push rod corresponds to the initial position of the power block.

[0011] Optionally, the servo motor is provided with a counterweight assembly, the counterweight assembly including a first wheel, the first wheel being fixedly sleeved on the outer surface of the servo motor output shaft, the outer surface of the first wheel being connected to a transmission belt, and the side of the transmission belt away from the first wheel being connected to a second wheel.

[0012] A gear is fixedly installed at the bottom of the second rotating wheel. The gear is movably installed on the upper surface of the rotating base. A gear ring meshes with one side of the gear. The gear ring is movably installed on the upper surface of the rotating base.

[0013] A balance block is fixedly installed on the surface of the gear ring. The surface of the balance block is provided with an adapter groove, which is adapted to the rotating base and is movably installed between the adapter groove and the rotating base.

[0014] Optionally, a second rotating shaft is movably mounted on both sides of the slide. A stress member is fixedly sleeved on the outer surface of the second rotating shaft. A second balance spring is fixedly connected to the top of the stress member. A connecting plate is fixedly connected to the end of the second balance spring away from the stress member. The connecting plate is fixedly connected to the counterweight.

[0015] Optionally, the initial position of the balance block is located in the middle of the side of the rotary seat, and the initial position of the screw sleeve is located in the middle of the lead screw.

[0016] Optionally, the travel rail is arc-shaped, and the inner cavity of the travel rail is adapted to the working trajectory of the boom.

[0017] Optionally, the power block has a socket hole on the side near the electric push rod that is adapted to the output shaft of the electric push rod.

[0018] Optionally, a sliding groove is provided on the inner side of the carriage, and the sliding groove is adapted to the carriage.

[0019] This invention provides a joint structure for a high-load robot, which has the following advantages:

[0020] 1. The joint structure of this high-load robot, through the following component, enables the second spring balance cylinder to follow the movement of the forearm, thereby reducing the stretching stroke of the forearm drive on the second spring balance cylinder, avoiding excessive stretching of the spring in the second spring balance cylinder, reducing the driving torque, and adjusting the robot's center of gravity when the forearm grips and lifts the workpiece, thus improving the robot's stability.

[0021] 2. The joint structure of this large-load robot, through the load balancing component, enables the power block to follow the drive of the upper arm and stretch the first balancing spring. After the forearm grasps the large-load workpiece, the tension of the first balancing spring is used to balance the load generated by the large-load workpiece, thereby achieving additional balance for the upper arm. By activating the hydraulic rod to pull the connecting piece, the end of the forearm away from the workpiece is pulled, thereby achieving additional balance for the forearm and thus reducing the additional driving torque after grasping the workpiece.

[0022] 3. The joint structure of this high-load robot, through the counterweight component, can flexibly adjust the position of the balance block during the forearm's gripping and lifting of the workpiece, thereby adjusting the robot's center of gravity and further improving the robot's stability. In conjunction with the stress component and the second balance spring, the stress component can press down on the base during the gripping of the workpiece, reducing the stress between the base and the fixing screws in the screw holes, and reducing the wear on the base. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the structure of the present invention;

[0024] Figure 2 is a schematic diagram of the structure of the present invention;

[0025] Figure 3 is a schematic diagram of the structure of the present invention;

[0026] Figure 4 is a schematic diagram of the positional relationship between the counterweight component and the following component of the present invention;

[0027] Figure 5 is a schematic diagram of the load balancing component of the present invention;

[0028] Figure 6 is a partially enlarged structural schematic diagram of point A in Figure 4 of this invention.

[0029] In the diagram: 1. Base; 11. Screw hole; 12. Rotary seat; 13. Mounting bracket; 14. Main arm; 15. Forearm; 16. First spring balance cylinder; 17. First rotating shaft; 2. Servo motor; 21. Lead screw; 22. Screw sleeve; 23. Slider; 24. Carriage; 25. Counterweight; 26. Second spring balance cylinder; 27. Hydraulic rod; 28. Connector; 29. ​​Slide groove; 3. Fixing frame; 31. Traveling rail; 32. First balance spring; 33. Power block; 34. Electric push rod; 4. First rotating wheel; 41. Transmission belt; 42. Second rotating wheel; 43. Gear; 44. Gear ring; 45. Balance block; 46. Adaptor groove; 5. Second rotating shaft; 51. Stress component; 52. Second balance spring; 53. Connecting plate. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Example 1: Please refer to Figures 1 to 4. The present invention provides a technical solution: a large-load robot joint structure, including a base 1, screw holes 11, a rotating seat 12, a mounting frame 13, a large arm 14, a small arm 15, and a first spring balance cylinder 16. The screw holes 11 are opened on the surface of the base 1. The rotating seat 12 is movably installed on the top of the base 1. The mounting frame 13 is fixedly installed on the upper surface of the rotating seat 12. The large arm 14 is movably installed on the inner side of the mounting frame 13. The small arm 15 is movably installed on the large arm 14, and a robotic claw is installed at one of its outwardly extending ends. There are two first spring balance cylinders 16, which are located on both sides of the large arm 14. A first rotating shaft 17 is fixedly installed on one side of the top of the connecting rod of the first spring balance cylinder 16. The first rotating shaft 17 is movably installed between the large arm 14 and the bottom of the first spring balance cylinder 16 is movably installed between the mounting frame 13 and the rotating seat 12. A following component is provided on the rotating seat 12. The following component includes a servo motor 2, which is fixedly installed on the bottom of the rotating seat 12.

[0032] A lead screw 21 is fixedly mounted on the output shaft of the servo motor 2. A screw sleeve 22 is screwed to the outer surface of the lead screw 21. A slider 23 is fixedly mounted on both sides of the screw sleeve 22. A slide 24 is movably mounted on the outer surface of the slider 23. The slide 24 is fixedly connected to the rotary seat 12.

[0033] The inner side of the carriage 24 is provided with a slide groove 29, which is adapted to the carriage 24;

[0034] A counterweight 25 is fixedly installed on one side of the screw sleeve 22. A second spring balance cylinder 26 is movably connected to the upper surface of the counterweight 25. A hydraulic rod 27 is installed inside the second spring balance cylinder 26. A connector 28 is movably installed on the output shaft of the hydraulic rod 27. The end of the connector 28 away from the hydraulic rod 27 is fixedly connected to the forearm 15.

[0035] The rotary table 12 is equipped with a load balancing component, which is used to improve the robot's load-bearing capacity.

[0036] Specifically, during use, the base 1 needs to be fixed to the base through the screw hole 11 using fixing screws to complete the robot installation. When the robot is in a balanced state, the load of the forearm 15 is balanced by the pulling force provided by the second spring balance cylinder 26. When the robot starts working, the direction is first adjusted by the swivel 12, and then the upper arm 14 starts to rotate. When the upper arm 14 rotates counterclockwise, its own balance is broken, but at the same time, it will pull the connecting rod on the first spring balance cylinder 16, causing the connecting rod to stretch the spring, thereby using the spring's pulling force to balance the load of the upper arm 14 during operation, thereby reducing the driving torque.

[0037] When the upper arm 14 rotates, the lower arm 15 begins to rotate counterclockwise to grip the workpiece. After the upper arm 14 rotates, the lower arm 15 will also rotate. At this time, the spring in the second spring balance cylinder 26 is in a re-stretched state. When the lower arm 15 rotates, the spring in the second spring balance cylinder 26 will be stretched again, which may exceed the stretching limit, causing spring fatigue and affecting the performance of the second spring balance cylinder 26. At the same time, during the driving process of the lower arm 15, the driving torque also needs to overcome the spring tension of the second spring balance cylinder 26, resulting in an increase in driving torque.

[0038] At this time, after the forearm 15 drives for one to two seconds, the spring in the second spring balance cylinder 26 is stretched a certain distance. Then, the servo motor 2 is started by the system to drive the lead screw 21 to rotate, so that the lead screw 21 drives the screw sleeve 22, which in turn drives the counterweight 25 to rise. This causes the second spring balance cylinder 26 to move with the forearm 15, thereby reducing the stretching stroke of the forearm 15 on the second spring balance cylinder 26, preventing the spring in the second spring balance cylinder 26 from being overstretched, and reducing the driving torque.

[0039] Furthermore, when the forearm 15 resets, the elastic force generated by the spring reset in the second spring balance cylinder 26 can assist the forearm 15 in resetting. When the forearm 15 resets to the position before the second spring balance cylinder 26 is stretched again, the servo motor 2 is started again to reset the second spring balance cylinder 26. When the forearm 15 also resets, the forearm 15 returns to balance.

[0040] Furthermore, when the forearm 15 needs to be lifted upwards, the driving torque needs to overcome the gravity of the forearm 15. Before the forearm 15 returns to balance, the power of the servo motor 2 needs to be increased so that the descent speed of the second spring balance cylinder 26 is faster than the lifting speed of the forearm 15. This causes the spring inside the second spring balance cylinder 26 to stretch again, and the tension provided by the spring reduces the driving torque for lifting the forearm 15 again. It should be noted that the stretching distance of the spring inside the second spring balance cylinder 26 must be controlled to avoid exceeding the stretching limit.

[0041] More specifically, when the forearm 15 grips the workpiece and rotates downwards, and when the forearm 15 lifts the workpiece and moves upwards, the robot's center of gravity will decrease and increase accordingly. The counterweight 25 moves in the opposite direction to balance the robot's center of gravity and improve the robot's stability.

[0042] Example 2: Please refer to Figures 1 to 5. The load balancing assembly includes a fixed frame 3. There are two fixed frames 3, which are located on both sides of the boom 14. One end of the fixed frame 3 is fixedly connected to the upper surface of the rotatable seat 12, and the other end is fixedly connected to the running rail 31.

[0043] One end of the inner cavity of the track 31 is fixedly connected to a first balance spring 32, and the other end of the first balance spring 32 is fixedly connected to a power block 33. The power block 33 is movably installed in the inner cavity of the track 31. An electric push rod 34 is fixedly connected to the top of the first spring balance cylinder 16 on the side away from the first rotating shaft 17. The output shaft of the electric push rod 34 corresponds to the initial position of the power block 33.

[0044] The shape of the travel rail 31 is arc-shaped, and the inner cavity of the travel rail 31 is adapted to the working trajectory of the boom 14;

[0045] The power block 33 has a socket hole on the side near the electric push rod 34 that is adapted to the output shaft of the electric push rod 34.

[0046] Based on Example 1, when the forearm 15 grips a heavy-load workpiece, the balance between the upper arm 14 and the forearm 15 will be further disrupted, resulting in an increase in driving torque.

[0047] To reduce the torque of the boom 14, the workpiece load can be determined first. If a large-load workpiece is to be gripped, the electric push rod 34 can be started before the boom 14 is driven. The electric push rod 34 is inserted into the power block 33 and locked with screws. When the boom 14 is started, it will drive the first spring balance cylinder 16 to rotate, which in turn drives the electric push rod 34 to rotate. The power block 33 can slide in the track 31 and stretch the first balance spring 32. In this way, after the forearm 15 grips the large-load workpiece, the tension of the first balance spring 32 can balance the load generated by the large-load workpiece on the boom 14.

[0048] The portion of the increase in driving torque due to the stretching of the first balance spring 32 will be offset by the first balance spring 32 when the upper arm 14 returns to its original position, thus keeping the overall torque generated by the stretching of the first balance spring 32 unchanged.

[0049] In order to reduce the torque of the forearm 15, the present invention replaces the connecting rod on the second spring balance cylinder 26 with a hydraulic rod 27. When the forearm 15 grabs a heavy load workpiece, the hydraulic rod 27 is activated to pull the connecting piece 28, thereby pulling the end of the forearm 15 away from the workpiece, thereby achieving additional balance of the forearm 15 and thus reducing the driving torque.

[0050] Example 3: Please refer to Figures 1 and 6. A counterweight assembly is provided on the servo motor 2. The counterweight assembly includes a first wheel 4. The first wheel 4 is fixedly sleeved on the outer surface of the output shaft of the servo motor 2. A transmission belt 41 is connected to the outer surface of the first wheel 4. A second wheel 42 is connected to the side of the transmission belt 41 away from the first wheel 4.

[0051] A gear 43 is fixedly installed at the bottom of the second rotating wheel 42. The gear 43 is movably installed on the upper surface of the rotating base 12. A gear ring 44 meshes with one side of the gear 43. The gear ring 44 is movably installed on the upper surface of the rotating base 12.

[0052] A balance block 45 is fixedly mounted on the surface of the gear ring 44. The surface of the balance block 45 is provided with an adapter groove 46, which is adapted to the rotary seat 12 and is movably installed between the adapter groove 46 and the rotary seat 12.

[0053] The initial position of the balance block 45 is in the middle of the side of the rotary seat 12, and the initial position of the screw sleeve 22 is in the middle of the lead screw 21.

[0054] Based on the above embodiments, when the forearm 15 grasps the load, due to the tilt of the upper arm 14 and the forearm 15, plus the weight of the load, the robot's center of gravity will shift towards the side that grasps the workpiece, thereby increasing the stress between the side of the base 1 away from the workpiece and the fixing screw in the screw hole 11, thus affecting the fixed position of the base 1.

[0055] During the gripping process of the forearm 15, the start of the servo motor 2 will simultaneously drive the first rotating wheel 4 to rotate, which in turn drives the transmission belt 41 to rotate the second rotating wheel 42. The second rotating wheel 42 can drive the gear 43 to rotate, which in turn drives the gear ring 44 to rotate. The gear ring 44 can drive the balance block 45 to rotate, so that the balance block 45 rotates to the side of the rotating base 12 away from the workpiece, thereby balancing the robot's center of gravity and reducing the wear on the fixed position of the base 1.

[0056] Similarly, when the forearm 15 is raised, the balance block 45 will rotate to the side of the turntable 12 closer to the workpiece, so as to flexibly adjust the center of gravity when the workpiece grasped by the forearm 15 is in different positions.

[0057] Example 4: Please refer to Figures 1 to 4. A second rotating shaft 5 is movably installed on both sides of the slide 24. A stress member 51 is fixedly sleeved on the outer surface of the second rotating shaft 5. A second balance spring 52 is fixedly connected to the top of the stress member 51. A connecting plate 53 is fixedly connected to the end of the second balance spring 52 away from the stress member 51. The connecting plate 53 is fixedly connected to the counterweight block 25.

[0058] Based on embodiment 3, when the forearm 15 grips the workpiece, the second spring balance cylinder 26 will rise. When the second spring balance cylinder 26 rises, it will pull the second balance spring 52, causing the second balance spring 52 to pull the upper end of the stress member 51 upward, thereby causing the lower end of the stress member 51 to move downward and then contact the base 1, and press down on the base 1, further reducing the stress between the base 1 and the fixing screw in the screw hole 11, and reducing the wear on the base 1.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-load robot joint structure, comprising a base (1), screw holes (11), a rotating base (12), a mounting bracket (13), a large arm (14), a small arm (15), and a first spring balance cylinder (16), wherein the screw holes (11) are formed on the surface of the base (1), the rotating base (12) is movably mounted on the top of the base (1), the mounting bracket (13) is fixedly mounted on the upper surface of the rotating base (12), the large arm (14) is movably mounted inside the mounting bracket (13), the small arm (15) is movably mounted on the large arm (14), and a robotic claw is mounted on one of its outwardly extending ends, and there are two first spring balance cylinders (16) located on both sides of the large arm (14), characterized in that: A first rotating shaft (17) is fixedly installed on one side of the top of the connecting rod of the first spring balance cylinder (16). The first rotating shaft (17) is movably installed between the first rotating shaft (17) and the upper arm (14). The bottom of the first spring balance cylinder (16) is movably installed between the bottom of the first spring balance cylinder (16) and the mounting bracket (13). A following component is provided on the rotating base (12). The following component includes a servo motor (2). The servo motor (2) is fixedly installed on the bottom of the rotating base (12). A lead screw (21) is fixedly installed on the output shaft of the servo motor (2). A screw sleeve (22) is spirally connected to the outer surface of the lead screw (21). A slider (23) is fixedly installed on both sides of the screw sleeve (22). A slide (24) is movably installed on the outer surface of the slider (23). The slide (24) is fixedly connected to the rotary seat (12). A counterweight (25) is fixedly installed on one side of the screw sleeve (22). A second spring balance cylinder (26) is movably connected to the upper surface of the counterweight (25). A hydraulic rod (27) is installed inside the second spring balance cylinder (26). A connector (28) is movably installed on the output shaft of the hydraulic rod (27). The end of the connector (28) away from the hydraulic rod (27) is fixedly connected to the forearm (15). The rotating base (12) is provided with a load balancing component, which is used to improve the robot's load-bearing performance.

2. The high-load robot joint structure according to claim 1, characterized in that: The load balancing assembly includes a fixed frame (3), there are two fixed frames (3), and they are located on both sides of the boom (14). One end of the fixed frame (3) is fixedly connected to the upper surface of the rotator (12), and the other end is fixedly connected to the running rail (31). One end of the inner cavity of the track (31) is fixedly connected to a first balance spring (32), and the other end of the first balance spring (32) is fixedly connected to a power block (33). The power block (33) is movably installed in the inner cavity of the track (31). An electric push rod (34) is fixedly connected to the top of the first spring balance cylinder (16) on the side away from the first rotating shaft (17). The output shaft of the electric push rod (34) corresponds to the initial position of the power block (33).

3. The high-load robot joint structure according to claim 2, characterized in that: The servo motor (2) is provided with a counterweight assembly, which includes a first wheel (4). The first wheel (4) is fixedly sleeved on the outer surface of the output shaft of the servo motor (2). A transmission belt (41) is connected to the outer surface of the first wheel (4). A second wheel (42) is connected to the side of the transmission belt (41) away from the first wheel (4). A gear (43) is fixedly installed at the bottom of the second rotating wheel (42). The gear (43) is movably installed on the upper surface of the rotating base (12). A gear ring (44) meshes on one side of the gear (43). The gear ring (44) is movably installed on the upper surface of the rotating base (12). A balance block (45) is fixedly installed on the surface of the gear ring (44). An adapter groove (46) is provided on the surface of the balance block (45). The adapter groove (46) is adapted to the rotating seat (12), and the adapter groove (46) and the rotating seat (12) are movably installed together.

4. The high-load robot joint structure according to claim 3, characterized in that: The slide (24) is movably mounted on both sides of a second rotating shaft (5). A stress member (51) is fixedly sleeved on the outer surface of the second rotating shaft (5). A second balance spring (52) is fixedly connected to the top of the stress member (51). A connecting plate (53) is fixedly connected to the end of the second balance spring (52) away from the stress member (51). The connecting plate (53) is fixedly connected to the counterweight (25).

5. The high-load robot joint structure according to claim 4, characterized in that: The initial position of the balance block (45) is in the middle of the side of the rotary seat (12), and the initial position of the screw sleeve (22) is in the middle of the lead screw (21).

6. The high-load robot joint structure according to claim 5, characterized in that: The shape of the track (31) is arc-shaped, and the inner cavity track of the track (31) is adapted to the working trajectory of the boom (14).

7. A high-load robot joint structure according to claim 6, characterized in that: The power block (33) has a socket hole on the side near the electric push rod (34) that is adapted to the output shaft of the electric push rod (34).

8. A high-load robot joint structure according to claim 7, characterized in that: The inner side of the slide (24) is provided with a slide groove (29), which is adapted to the slide (24).

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