Gravity compensation type mechanical arm driven by pneumatic motor

Abstract

The invention discloses a gravity compensation type mechanical arm driven by a pneumatic motor, and relates to the field of mechanical arms, a single-section mechanical arm comprises a pitching joint, an air cylinder compensation system, a yawing joint and a synchronous belt type parallel arm rod, and pitching and rotation two-degree-of-freedom motion can be completed; the mechanical arm adopts an air cylinder type active compensation technology, gas pressure is converted into compensation torque through an air cylinder and a connecting rod mechanism, and the driving torque needed by pitching motion is reduced; and the mass of the mechanical arm is reduced. The multi-joint super-long mechanical arm can be composed of multiple sections of similar single-section mechanical arms, and has the functions of being large in working space, low in energy consumption, multiple in motion freedom degree, capable of achieving large-space continuous operation, complex-space obstacle avoidance and the like.

Description

Technical Field

[0001] This invention relates to the field of robotic arms, and in particular to a gravity-compensated robotic arm driven by a pneumatic motor. Background Technology

[0002] The application of anti-corrosion coatings to the interior of a ship is a crucial process for ensuring the durability and safety of the ship's structure. Traditional manual spraying requires operators to wear heavy protective gear and be exposed to high concentrations of volatile organic compounds (VOCs) for extended periods in confined ship cabins, resulting in significant occupational health risks, low spraying efficiency, and poor coating uniformity. With the development of industrial automation technology, robotic arms, due to their programmability, high repeatability, and strong operational stability, are gradually becoming the ideal solution to replace manual spraying.

[0003] Currently, industrial robotic arms are primarily driven by electric drives, including AC servo motors, DC motors, and stepper motors. However, in specific application scenarios such as spraying anti-corrosion coatings inside ship hulls, traditional electrically driven robotic arms have significant technical limitations: electric drive systems require auxiliary components such as reducers, encoders, and drivers, resulting in a large overall size and weight of the robotic arm, making it difficult to deploy flexibly among complex structures (such as stiffeners and longitudinal girder) within the ship's cabin; at the same time, the continuous operation of the motor consumes a lot of energy, requiring an external high-voltage power supply or a large-capacity battery pack, further limiting its applicability in environments without power or in flammable environments. The concentration of explosive gas mixtures formed by the volatilization of paint inside the ship's hull is usually within the lower explosive limit. However, the electrically driven robotic arm may cause deflagration accidents during operation due to the following factors: When the end effector of the robotic arm encounters an obstacle (such as a weld protrusion or supporting structure), the sudden increase in motor load can easily lead to stall, and the rotor windings will rapidly heat up to above the ignition point under low speed and high current conditions; Electric sparks may be generated: friction between the motor commutator and brushes, contactor opening and closing, or cable insulation damage can all generate electric sparks, which can become ignition sources in an explosive gas environment; When the electric drive system is running, friction between the robotic arm body and the paint delivery pipeline may generate static electricity. If an effective grounding device is not provided, the electrostatic discharge energy can reach the millijoule level, which is enough to ignite low flash point paint vapors. The high temperature and humidity environment inside the ship's cabin will accelerate the aging of the motor insulation materials and reduce the reliability of the drive system. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a gravity-compensated robotic arm driven by a pneumatic motor, so as to further solve the safety hazards of electric drive of robotic arms.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A pneumatically driven gravity-compensated robotic arm includes a robotic arm base, a first robotic arm at the upper end of the robotic arm base, a second robotic arm at one side of the upper end face of the first robotic arm, and a third robotic arm at one side of the upper end face of the second robotic arm. The upper end face of the third robotic arm is provided with an end pneumatic rotary nozzle. The first, second, and third robotic arms are all single-section robotic arms. Each single-section robotic arm includes a pitch joint, a cylinder compensation system, a yaw joint, and a synchronous belt parallel arm.

[0007] Preferably, the end pneumatic rotary nozzle includes a pneumatic motor, which includes a housing, a rotor, and an elastic hose. The rotor is disposed inside the housing, and the elastic hose is fixedly connected to the inner wall of the housing. The two ends of the elastic hose extend through the housing to the outside, and the two ends of the elastic hose are fixedly connected to a drive air pipe.

[0008] Preferably, the rotor includes a shaft and rollers; the shaft is rotatably mounted on the housing, the rollers are rotatably mounted on the shaft, and the axis of the rollers is parallel to the axis of the shaft; a plurality of rollers are distributed along the circumference of the shaft, the plurality of distribution positions are evenly distributed along the circumference of the shaft, a spray nozzle is fixedly connected to the front end of the shaft, a rotary joint is threaded to the rear end of the shaft, and a paint spraying pipe is inserted into the rear end of the rotary joint.

[0009] Preferably, the synchronous belt parallel boom has pitch joints at both ends, and the inner wall of the synchronous belt parallel boom is provided with a cylinder compensation system.

[0010] Preferably, the pitch joint includes a pitch output arm, a driven arm, and a pitch drive mechanism. The pitch output arm and the driven arm are respectively inserted into the inner walls of the synchronous belt parallel arm. Screws are provided on the outer sides of both ends of the synchronous belt parallel arm. The screws pass through the synchronous belt parallel arm and are threadedly connected to the pitch output arm and the driven arm. The pitch output arm is provided with a top frame platform, and the pitch drive mechanism is provided inside the top frame platform. The driven arm is hinged to a bottom frame platform.

[0011] Preferably, the top frame platform is provided with a yaw joint, the yaw joint includes a yaw motor, the yaw motor is fixedly connected to the inner surface of the top frame platform, the output end of the yaw motor passes through the top frame platform and is fixedly connected to the yaw joint drive gear, the upper surface of the top frame platform is fixedly connected to the yaw joint spindle pull plate, the upper surface of the yaw joint spindle pull plate is fixedly connected to a first deep groove ball bearing, the upper end of the first deep groove ball bearing is fixedly connected to a yaw joint bearing cover plate, the upper surface of the yaw joint bearing cover plate is fixedly connected to a yaw joint driven gear, and the yaw joint driven gear meshes with the yaw joint drive gear.

[0012] Preferably, the pitch drive mechanism includes a pitch motor, a pitch motor is fixedly connected to the inner surface of the top frame platform, a pitch motor connecting bracket is provided on one side of the pitch motor and fixedly connected to the top frame platform, one end face of the pitch motor is fixedly connected to the inner surface of the pitch motor connecting bracket, a pitch joint drive gear is fixedly connected to one side of the pitch motor through the pitch motor connecting bracket, a pitch joint driven gear is fixedly connected to the outer end face of the pitch output arm, a second deep groove ball bearing is fixedly connected to the outer side of the main shaft of the pitch joint driven gear, the side surface of the second deep groove ball bearing is fixedly connected to the inner surface of the bottom frame platform, and a pitch driven gear bearing cover plate is fixedly connected to the inner end face of the pitch output arm.

[0013] Preferably, both sides of the top frame platform and the bottom frame platform are rotatably connected to synchronous pulleys, and the synchronous pulleys located on the same side of the parallel arm are engaged with a synchronous belt. The main shaft of the pitch joint passive gear passes through one side wall of the bottom frame platform and is fixedly connected to the synchronous pulley on that side.

[0014] Preferably, the cylinder compensation system includes a cylinder, the outer wall of the cylinder is fixedly connected to the inner wall of the synchronous belt parallel boom, the cylinder output end is fixedly connected to a cylinder connector, both the front and rear end faces of the cylinder connector are fixedly connected to pulleys, the pulleys are slidably engaged with the pitch output end boom, the front end of the cylinder connector is hinged to a connecting rod, and the free end of the connecting rod is hinged to the bottom frame platform.

[0015] Preferably, a connecting platform is fixedly connected to the upper surface of the base, and a yaw joint is fixedly connected inside the connecting platform. The yaw joint passive gear of the yaw joint is fixedly connected to the lower surface of the bottom frame platform on the first robotic arm. The upper surface of the yaw joint passive gear on the first robotic arm is fixedly connected to the lower surface of the bottom frame platform on the second robotic arm. The upper surface of the yaw joint passive gear on the second robotic arm is fixedly connected to the lower surface of the bottom frame platform on the third robotic arm. A nozzle connecting bracket is fixedly connected to the upper surface of the yaw joint passive gear on the third robotic arm. The front end face of the nozzle connecting bracket is fixedly connected to the rear end face of the housing.

[0016] The present invention has the following beneficial effects:

[0017] Completely solves the safety hazards of electric drives: This robotic arm is driven by a pneumatic motor, and the entire arm has no electronic components. In many industrial environments, electronic components may malfunction due to various factors (such as humidity, dust, electromagnetic interference, etc.), even causing safety hazards such as short circuits and fires. Because this robotic arm has no electronic components, it fundamentally avoids these potential safety hazards associated with electric drives, thus improving operational safety.

[0018] Larger workspace, smaller size and weight, and lower energy consumption: Thanks to its gravity compensation system, this new cylinder-type gravity-compensated ultra-long robotic arm offers numerous advantages over traditional industrial robotic arms. Traditional robotic arms, limited by their structure and operating principles, often have relatively small workspaces and, to ensure performance, are typically large in size and weight, resulting in higher energy consumption. This robotic arm's gravity compensation system allows for more flexible posture adjustments during operation, expanding its workspace; simultaneously, its optimized structure results in smaller size and weight, requiring less energy during operation and improving energy efficiency.

[0019] Without significantly increasing the size and mass of the robotic arm, and enabling variable end-effector load: Compared to existing spring-force compensated and counterweight compensated robotic arms, this new cylinder-type gravity-compensated ultra-long robotic arm utilizes compressed air pressure energy compensation. The compression equipment and compressed air can be placed and supplied independently of the robotic arm, meaning that unlike spring-force compensated and counterweight compensated arms, there is no need to install numerous additional compensation components on the robotic arm itself, thus avoiding excessive increases in the robotic arm's size and mass. Furthermore, by adjusting the compensation air pressure value at any time, the compensation torque can be changed, thereby enabling variable end-effector load. This allows the robotic arm to adapt to more diverse load requirements in various work scenarios, improving its versatility and flexibility. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the first embodiment of the present invention.

[0022] Figure 2 This is a partial view of the nozzle and piping of the first embodiment of the present invention.

[0023] Figure 3 This is a view of the first embodiment of the present invention after removing the pneumatic motor stator and drive pipeline.

[0024] Figure 4 for Figure 3 Cross-sectional view.

[0025] Figure 5 This is a schematic diagram of the component structure according to the first embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the overall structure of Example 2.

[0027] Figure 7 This is a schematic diagram of the internal structure of Example 2.

[0028] Figure 8 This is a cross-sectional view of the internal structure of Embodiment 2.

[0029] Figure 9 This is a schematic diagram of the pitch drive mechanism in Embodiment 2.

[0030] Figure 10 This is a schematic diagram of the yaw drive mechanism in Embodiment 2.

[0031] Figure 11 This is a schematic diagram of the connection between the two robotic arms in Embodiment 2.

[0032] In the diagram: A. First robotic arm; B. Second robotic arm; C. Third robotic arm; D. End-effector pneumatic rotary nozzle; E. Robotic arm base; 1. Nozzle; 2. Rotary joint; 3. Paint spraying line; 4. Housing; 5. Shaft; 6. Roller; 7. Flexible hose; 8. Synchronous belt parallel arm; 9. Drive air pipe; 101. Yaw motor; 102. Pitch motor; 103. Pitch output arm; 104. Driven arm; 105. First deep groove ball bearing; 106. Connecting platform; 107. Pitch joint driven gear 108. Pitch joint drive gear; 109. Yaw joint drive gear; 110. Yaw joint driven gear; 11. Top frame platform; 12. Bottom frame platform; 13. Synchronous belt pulley; 14. Synchronous belt; 15. Pulley; 16. Cylinder; 17. Cylinder connector; 18. Connecting rod; 19. Pitch driven gear bearing cover plate; 20. Pitch motor connecting bracket; 21. Nozzle connecting bracket; 201. Yaw joint bearing cover plate; 202. Second deep groove ball bearing; 203. Yaw joint main shaft pull plate; Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figures 1 to 5As shown, the pneumatically driven gravity-compensated robotic arm of this embodiment includes a robotic arm base E, a first robotic arm A on the upper end of the robotic arm base E, a second robotic arm B on one side of the upper end face of the first robotic arm A, a third robotic arm C on one side of the upper end face of the second robotic arm B, and an end pneumatic rotary nozzle D on the upper end face of the third robotic arm C. The first robotic arm A, the second robotic arm B and the third robotic arm C are all single-section robotic arms. Each single-section robotic arm includes a pitch joint, a cylinder compensation system, a yaw joint and a synchronous belt parallel arm 8.

[0036] The end pneumatic rotary nozzle D includes a pneumatic motor, which includes a housing 4, a rotor, and an elastic hose 7. The housing 4 contains a rotor, and the inner wall of the housing 4 is fixedly connected to the elastic hose 7. The two ends of the elastic hose 7 pass through the housing 4 and extend to the outside. The two ends of the elastic hose 7 are fixedly connected to a drive air pipe 9.

[0037] The rotor includes a rotating shaft 5 and rollers 6; the rotating shaft 5 is rotatably mounted on the housing 4, and the rollers 6 are rotatably mounted on the rotating shaft 5, with the axis of the rollers 6 parallel to the axis of the rotating shaft 5; multiple rollers 6 are distributed along the circumference of the rotating shaft 5, and the multiple distribution positions are evenly distributed along the circumference of the rotating shaft 5; a spray nozzle 1 is fixedly connected to the front end of the rotating shaft 5, and a rotary joint 2 is threadedly connected to the rear end of the rotating shaft 5, with a paint spraying pipe 3 inserted into the rear end of the rotary joint 2.

[0038] like Figures 1 to 5 As shown, during use, compressed air enters the flexible hose 7 of the pneumatic motor through the drive air pipe 9. The flexible hose 7 is fixed to the inner wall of the housing 4, and its two ends are connected to the external drive air pipe 9 to provide a power source for the pneumatic motor. The compressed air entering the flexible hose 7 exerts a force on the rotor. The rotor consists of a rotating shaft 5 and rollers 6. The rollers 6 are rotatably mounted on the rotating shaft 5, and their axes are parallel to the axis of the rotating shaft 5. Multiple rollers 6 are evenly distributed along the circumference of the rotating shaft 5. The compressed air acts on the rollers 6, causing the rotor to experience a torque, thereby driving the rotating shaft 5 to rotate around its own axis within the housing 4. A nozzle 1 is fixedly connected to the front end of the rotating shaft 5. As the rotating shaft 5 rotates, the nozzle 1 also rotates. A rotary joint 2 is threaded to the rear end of the rotating shaft 5. A paint spraying pipe 3 is inserted into the rear end of the rotary joint 2. The paint material is delivered to the nozzle 1 through the paint spraying pipe 3 and the rotary joint 2. The nozzle 1 has an opening at its front end. After the paint in the paint spraying pipe 3 is pressurized, it can achieve uniform painting during the rotation of the nozzle 1.

[0039] Example 2

[0040] like Figures 6 to 11 As shown, based on Embodiment 1, the synchronous belt parallel boom 8 has pitch joints at both ends, and the inner wall of the synchronous belt parallel boom 8 is provided with a cylinder compensation system.

[0041] The pitch joint includes a pitch output arm 103, a driven arm 104, and a pitch drive mechanism. The pitch output arm and the driven arm 104 are respectively inserted into the two ends of the inner wall of the synchronous belt parallel arm 8. Screws are provided on the outer side of both ends of the synchronous belt parallel arm 8. The screws pass through the synchronous belt parallel arm 8 and are threadedly connected to the pitch output arm and the driven arm 104. The pitch output arm is provided with a top frame platform 11, and the pitch drive mechanism is provided inside the top frame platform 11. The driven arm 104 is hinged to a bottom frame platform 12.

[0042] The top frame platform 11 is equipped with a yaw joint, which includes a yaw motor 101. The yaw motor 101 is fixedly connected to the inner surface of the top frame platform 11. The output end of the yaw motor 101 passes through the top frame platform 11 and is fixedly connected to the yaw joint drive gear 109. The top end of the top frame platform 11 is fixedly connected to the yaw joint spindle pull plate 203. The top end of the yaw joint spindle pull plate 203 is fixedly connected to the upper end of the yaw joint spindle pull plate 203. The first deep groove ball bearing 105 is fixedly connected to the upper end of the first deep groove ball bearing 105. The yaw joint bearing cover plate 201 is fixedly connected to the upper end of the yaw joint bearing cover plate 201. The yaw joint driven gear 110 is fixedly connected to the upper end of the yaw joint drive gear 109.

[0043] The pitch drive mechanism includes a pitch motor 102. The pitch motor 102 is fixedly connected to the inner surface of the top frame platform 11. A pitch motor connecting bracket 20 is provided on one side of the pitch motor 102 and fixedly connected to the top frame platform 11. One end face of the pitch motor 102 is fixedly connected to the inner surface of the pitch motor connecting bracket 20. A pitch joint drive gear 108 is fixedly connected to one side of the pitch motor connecting bracket 20 through the pitch motor 102. A pitch joint driven gear 107 is fixedly connected to the outer end face of the pitch output arm 103. A second deep groove ball bearing 202 is fixedly connected to the outer side of the main shaft of the pitch joint driven gear 107. The side surface of the second deep groove ball bearing 202 is fixedly connected to the inner surface of the bottom frame platform 12. A pitch driven gear bearing cover plate 19 is fixedly connected to the inner end face of the pitch output arm 103.

[0044] Both sides of the top frame platform 11 and the bottom frame platform 12 are rotatably connected to synchronous pulleys 13. The synchronous pulleys 13 located on the same side of the parallel arm mesh with the synchronous belt 14. The main shaft of the pitch joint passive gear 107 passes through one side wall of the bottom frame platform 12 and is fixedly connected to the synchronous pulley 13 on that side.

[0045] A connecting platform 106 is fixedly connected to the upper surface of the base. A yaw joint is fixedly connected inside the connecting platform 106. The yaw joint passive gear 110 of the yaw joint is fixedly connected to the lower surface of the bottom frame platform 12 on the first robotic arm A. The upper surface of the yaw joint passive gear 110 on the first robotic arm A is fixedly connected to the lower surface of the bottom frame platform 12 on the second robotic arm B. The upper surface of the yaw joint passive gear 110 on the second robotic arm B is fixedly connected to the lower surface of the bottom frame platform 12 on the third robotic arm C. A nozzle connecting bracket 21 is fixedly connected to the upper surface of the yaw joint passive gear 110 on the third robotic arm C. The front end of the nozzle connecting bracket 21 is fixedly connected to the rear end of the housing 4.

[0046] like Figures 6 to 11 As shown, during use, the pitch motor 102 in the pitch drive mechanism is fixed to the inner surface of the top frame platform 11 and further secured by the pitch motor connecting bracket 20. After the pitch motor 102 is started, its output end drives the pitch joint drive gear 108 to rotate. Since the pitch joint driven gear 107 meshes with the pitch joint drive gear 108, according to the gear transmission principle, the pitch joint driven gear 107 will rotate accordingly. The pitch joint driven gear 107 is fixed to the outer end face of the pitch output arm 103, and its rotation will drive the pitch output arm 103 to rotate around the axis. The pitch output arm 103 is inserted into one end of the inner wall of the synchronous belt parallel arm 8 and is fixedly connected to the synchronous belt parallel arm 8 by screws. Therefore, the rotation of the pitch output arm 103 will cause the relevant parts of the entire robotic arm to produce a pitching motion. Meanwhile, the main shaft of the pitch joint driven gear 107 passes through one side wall of the bottom frame platform 12 and is fixedly connected to the synchronous pulley 13 on that side. When the pitch joint driven gear 107 rotates, it drives the synchronous pulley 13 to rotate, which in turn drives another synchronous pulley 13 located on the same side of the parallel arm to rotate through the synchronous belt 14, realizing the synchronous transmission of motion and making the pitch movement of the robotic arm more stable. The driven arm 104 is inserted into the other end of the inner wall of the synchronous belt parallel arm 8 and fixed with screws. The driven arm 104 is hinged to the bottom frame platform 12, providing a stable support structure for the pitch movement, ensuring that the robotic arm will not sway or deviate during the pitch process, ensuring the accuracy of the movement, and also facilitating disassembly.

[0047] like Figures 1 to 5As shown, during use, the top frame platform 11 has a yaw joint inside, and the yaw motor 101 is fixed to the inner surface of the top frame platform 11. Its output end passes through the top frame platform 11 and is fixedly connected to the yaw joint drive gear 109. After the yaw motor 101 is started, it drives the yaw joint drive gear 109 to rotate. The yaw joint driven gear 110 meshes with the yaw joint drive gear 109, and the yaw joint driven gear 110 is fixed to the top frame platform 11 through structures such as the yaw joint bearing cover plate 201, the first deep groove ball bearing 105, and the yaw joint main shaft pull plate 203. Therefore, the yaw joint driven gear 110 will rotate around its own axis, thereby realizing the yaw motion of the robotic arm in the horizontal direction. A yaw joint is fixedly connected within the connecting platform 106 on the upper surface of the base. The yaw joint passive gear 110 of this yaw joint is fixedly connected to the lower surface of the bottom frame platform 12 on the first robotic arm A. The upper surface of the yaw joint passive gear 110 on the first robotic arm A is fixedly connected to the lower surface of the bottom frame platform 12 on the second robotic arm B. The upper surface of the yaw joint passive gear 110 on the second robotic arm B is fixedly connected to the lower surface of the bottom frame platform 12 on the third robotic arm C. This connection method enables a linkage between the robotic arms at each level. When the top yaw joint rotates, the entire robotic arm system can achieve synchronous yaw motion through the connection and transmission of the passive gears 110 at each level, thus expanding the working range and flexibility of the robotic arm. The third robotic arm C has a yaw joint passive gear 110 with a nozzle connecting bracket 21 fixedly connected to its upper end face. The front end face of the nozzle connecting bracket 21 is fixedly connected to the rear end face of the housing 4, which ultimately transmits the yaw motion to the pneumatic rotating nozzle D at the end, so that the nozzle can be adjusted in the horizontal direction to meet the needs of different painting positions.

[0048] Example 3

[0049] like Figures 6 to 11 As shown, based on Embodiment 1 and Embodiment 2, the cylinder compensation system includes a cylinder 16. The outer wall of the cylinder 16 is fixedly connected to the inner wall of the synchronous belt parallel arm 8. A cylinder connector 17 is fixedly connected to the output end of the cylinder 16. Pulleys 15 are fixedly connected to both the front and rear ends of the cylinder connector 17. The pulleys 15 are slidably engaged with the pitch output arm 103. A connecting rod 18 is hinged to the front end of the cylinder connector 16. The free end of the connecting rod 18 is hinged to the bottom frame platform 12.

[0050] like Figures 6 to 11As shown, during use, the outer wall of cylinder 16 in the cylinder compensation system is fixedly connected to the inner wall of the synchronous belt parallel arm 8, and cylinder 16 provides pressure energy through compressed air. When the robotic arm is in different postures, the output end of cylinder 16 will extend or retract as needed, generating a compensating force opposite to the direction of gravity of the robotic arm. A cylinder connector 17 is fixedly connected to the output end of cylinder 16. The pulleys 15 on the front and rear end faces of cylinder connector 17 slide in cooperation with the pitch output arm 103, allowing cylinder connector 17 to move smoothly relative to the pitch output arm 103. A connecting rod 18 is hinged to the front end of cylinder connector 17, and the free end of connecting rod 18 is hinged to the bottom frame platform 12. When the output end of cylinder 16 extends or retracts, the force is transmitted to the bottom frame platform 12 through cylinder connector 17 and connecting rod 18, thereby balancing part or all of the weight of the robotic arm. This reduces the influence of gravity on the robotic arm's pitch and other movements, allowing the robotic arm to perform various actions more easily and flexibly. It also reduces energy consumption and does not excessively increase the size and mass of the robotic arm like spring force compensation and counterweight compensation. Furthermore, by adjusting the air pressure within cylinder 16, the magnitude of the compensation force can be changed, enabling variable load at the end of the robotic arm and improving its versatility and adaptability.

[0051] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A gravity-compensated robotic arm driven by a pneumatic motor, characterized in that: The system includes a robotic arm base (E), a first robotic arm (A) on the upper end of the robotic arm base (E), a second robotic arm (B) on one side of the upper end face of the first robotic arm (A), a third robotic arm (C) on one side of the upper end face of the second robotic arm (B), and an end pneumatic rotary nozzle (D) on the upper end face of the third robotic arm (C). The first robotic arm (A), the second robotic arm (B), and the third robotic arm (C) are all single-section robotic arms. Each single-section robotic arm includes a pitch joint, a cylinder compensation system, a yaw joint, and a synchronous belt parallel boom (8).

2. The pneumatically driven gravity-compensated robotic arm according to claim 1, characterized in that: The terminal pneumatic rotary nozzle (D) includes a pneumatic motor, which includes a housing (4), a rotor, and an elastic hose (7). The housing (4) contains a rotor, and the inner wall of the housing (4) is fixedly connected to the elastic hose (7). The two ends of the elastic hose (7) extend through the housing (4) to the outside. The two ends of the elastic hose (7) are fixedly connected to a drive air pipe (9).

3. A pneumatically driven gravity-compensated robotic arm according to claim 2, characterized in that: The rotor includes a rotating shaft (5) and rollers (6); the rotating shaft (5) is rotatably mounted on the housing (4), and the rollers (6) are rotatably mounted on the rotating shaft (5). The axis of the rollers (6) is parallel to the axis of the rotating shaft (5). Along the circumferential direction of the rotating shaft (5), there are multiple distribution positions of the rollers (6), and the multiple distribution positions are evenly distributed along the circumferential direction of the rotating shaft (5). A spray nozzle (1) is fixedly connected to the front end of the rotating shaft (5), and a rotary joint (2) is threadedly connected to the rear end of the rotating shaft (5). A paint spraying pipe (3) is inserted into the rear end of the rotary joint (2).

4. The pneumatically driven gravity-compensated robotic arm according to claim 1, characterized in that: The synchronous belt parallel boom (8) is provided with pitch joints at both ends, and the inner wall of the synchronous belt parallel boom (8) is provided with a cylinder compensation system.

5. A pneumatically driven gravity-compensated robotic arm according to claim 3, characterized in that: The pitch joint includes a pitch output arm (103), a driven arm (104), and a pitch drive mechanism. The pitch output arm and the driven arm (104) are respectively inserted into the two ends of the inner wall of the synchronous belt parallel arm (8). Screws are provided on the outer side of both ends of the synchronous belt parallel arm (8). The screws pass through the synchronous belt parallel arm (8) and are threadedly connected to the pitch output arm and the driven arm (104). The pitch output arm is provided with a top frame platform (11). The pitch drive mechanism is provided inside the top frame platform (11). The driven arm (104) is hinged to a bottom frame platform (12).

6. A pneumatically driven gravity-compensated robotic arm according to claim 5, characterized in that: The top frame platform (11) is equipped with a yaw joint, which includes a yaw motor (101). The yaw motor (101) is fixedly connected to the inner surface of the top frame platform (11). The output end of the yaw motor (101) passes through the top frame platform (11) and is fixedly connected to a yaw joint drive gear (109). The top end face of the top frame platform (11) is fixedly connected to a yaw joint spindle pull plate (203). The top end face of the yaw joint spindle pull plate (203) is fixedly connected to a first deep groove ball bearing (105). The top end of the first deep groove ball bearing (105) is fixedly connected to a yaw joint bearing cover plate (201). The top end face of the yaw joint bearing cover plate (201) is fixedly connected to a yaw joint driven gear (110). The yaw joint driven gear (110) meshes with the yaw joint drive gear (109).

7. A pneumatically driven gravity-compensated robotic arm according to claim 5, characterized in that: The pitch drive mechanism includes a pitch motor (102). The pitch motor (102) is fixedly connected to the inner surface of the top frame platform (11). A pitch motor connecting bracket (20) fixedly connected to the top frame platform (11) is provided on one side of the pitch motor (102). One end face of the pitch motor (102) is fixedly connected to the inner surface of the pitch motor connecting bracket (20). A pitch joint drive gear (108) is fixedly connected to one side of the pitch motor connecting bracket (20) through the pitch motor (102). A pitch joint driven gear (107) is fixedly connected to the outer end face of the pitch output arm (103). A second deep groove ball bearing (202) is fixedly connected to the outer side of the main shaft of the pitch joint driven gear (107). The side surface of the second deep groove ball bearing (202) is fixedly connected to the inner surface of the bottom frame platform (12). A pitch driven gear bearing cover plate (19) is fixedly connected to the inner end face of the pitch output arm (103).

8. A pneumatically driven gravity-compensated robotic arm according to claim 7, characterized in that: Both sides of the top frame platform (11) and the bottom frame platform (12) are rotatably connected to synchronous pulleys (13). The synchronous pulleys (13) located on the same side of the parallel arm are meshed with a synchronous belt (14). The main shaft of the pitch joint passive gear (107) passes through one side wall of the bottom frame platform (12) and is fixedly connected to the synchronous pulley (13) on that side.

9. A pneumatically driven gravity-compensated robotic arm according to claim 4, characterized in that: The cylinder compensation system includes a cylinder (16), the outer wall of the cylinder (16) is fixedly connected to the inner wall of the synchronous belt parallel arm (8), the output end of the cylinder (16) is fixedly connected to a cylinder connector (17), the front and rear end faces of the cylinder connector (17) are fixedly connected to pulleys (15), the pulleys (15) are slidably engaged with the pitch output arm (103), the front end of the cylinder (16) connector is hinged to a connecting rod (18), the free end of the connecting rod (18) is hinged to the bottom frame platform (12).

10. A pneumatically driven gravity-compensated robotic arm according to claim 1, characterized in that: A connecting platform (106) is fixedly connected to the upper surface of the base. A yaw joint is fixedly connected inside the connecting platform (106). The yaw joint passive gear (110) of the yaw joint is fixedly connected to the lower surface of the bottom frame platform (12) provided on the first robotic arm (A). The upper surface of the yaw joint passive gear (110) provided on the first robotic arm (A) is fixedly connected to the lower surface of the bottom frame platform (12) provided on the second robotic arm (B). The upper surface of the yaw joint passive gear (110) provided on the second robotic arm (B) is fixedly connected to the lower surface of the bottom frame platform (12) provided on the third robotic arm (C). A nozzle connecting bracket (21) is fixedly connected to the upper surface of the yaw joint passive gear (110) provided on the third robotic arm (C). The front end of the nozzle connecting bracket (21) is fixedly connected to the rear end of the housing (4).

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