Robot arm with controllable damping

Abstract

The invention relates to a controllable damping mechanical arm, in particular to a controllable damping robot arm. The technical problem to be solved is to provide a robot arm with controllable damping. According to the technical scheme, the robot arm with the controllable damping comprises a base; a first joint is arranged on the base, the magnetorheological fluid damper is arranged in the first joint, the first joint is connected with a second joint through the magnetorheological fluid damper, a magnet exciting coil is arranged in the magnetorheological fluid damper, a cavity of the magnetorheological fluid damper is filled with magnetorheological fluid, and after the magnet exciting coil is powered on, the shear yield strength of a magnetic material changes. And continuous adjustment of the damping force is achieved. According to the magnetorheological fluid damper, the size of the damping piece in the cavity of the magnetorheological fluid damper can be mechanically adjusted, so that the damping area is increased or decreased, and the function of partially mechanically adjusting the damping precision is achieved.

Description

Technical Field

[0001] This invention relates to a controllable damping robotic arm, and more particularly to a controllable damping robotic arm. Background Technology

[0002] Existing robots mainly use damping methods by adding linear hydraulic balance bars or spring cylinders at the joints of the robotic arm, while better ones use linear magnetorheological fluid dampers.

[0003] Linear magnetorheological fluid dampers primarily achieve their damping effect through the control current.

[0004] The linear magnetorheological fluid damper is installed between two robotic arms with movable connections at both ends. This connection method provides only slightly better damping effect than ordinary dampers on the robotic arms. Its vibration control and stability still have certain defects. Furthermore, the internal components of the damper cannot be adjusted according to the operating precision of the robotic arms, resulting in poor adaptability. Summary of the Invention

[0005] To overcome the shortcomings of linear magnetorheological fluid dampers installed between two robotic arms with movable connections at both ends, which only provide slightly better damping than ordinary dampers and have certain defects in vibration control and stability, and whose internal components cannot be adjusted according to the precision of the robotic arm, a controllable damping robotic arm is provided.

[0006] The technical implementation of the present invention is as follows: a controllable damping robotic arm, the robotic arm including a base, a first joint provided on the base, a magnetorheological fluid damper disposed in the first joint, the first joint being connected to a second joint through the magnetorheological fluid damper, an excitation coil being provided inside the magnetorheological fluid damper, the cavity of the magnetorheological fluid damper being filled with magnetorheological fluid, after the excitation coil is energized, the shear yield strength of the magnetic material changes, thereby realizing continuous adjustment of the damping force.

[0007] Furthermore, the magnetorheological fluid damper includes a housing, a first closed loop, an excitation coil, a second closed loop, an end cover, a rotating shaft, a bushing, and a damping adjustment structure. The first closed loop and the second closed loop are provided inside the housing. The excitation coil is provided between the housing and the first closed loop. The housing is sealed by the end cover. The rotating shaft passes through the middle of the housing and the end cover. The bushing is provided on the rotating shaft, and the damping adjustment structure is provided on the bushing.

[0008] Furthermore, the robotic arm is equipped with multiple joints, and each joint is equipped with a magnetorheological fluid damper.

[0009] Furthermore, magnetorheological fluid is provided in the cavities of the first closed ring and the second closed ring, and magnetorheological fluid is provided between the second closed ring and the bushing. The second closed ring is provided with a second through hole for mutual circulation of magnetorheological fluid, and a first through hole is provided on the housing. The first through hole of the housing is sealed by screws.

[0010] Furthermore, the damping adjustment structure includes a damping shell, damping blocks, adjusting blocks, a small bevel gear, and a rotating block. The damping shell is fixedly connected to the bushing. The damping shell contains damping blocks and adjusting blocks. The two damping blocks are slidably connected to the damping shell. The adjusting block is located between the two damping blocks and is slidably connected to the two damping blocks. A rotating block is fixed on the bushing. The threaded rod on the small bevel gear passes through the bushing and is rotatably connected to the rotating block. The threaded rod is threadedly connected to the adjusting block. The adjusting block is wedge-shaped. When the adjusting block moves downward through the threaded rod on the small bevel gear, the two damping blocks move to both sides of the damping shell.

[0011] Furthermore, damping grooves are provided on the damping housing.

[0012] Furthermore, the damping adjustment structure also includes an adjustment shaft, a large bevel gear, and an inner bearing. One end of the adjustment shaft is connected to the large bevel gear, which meshes with the small bevel gear. The adjustment shaft is rotatably connected to the inner side of the bushing through the inner bearing. The adjustment shaft and the large bevel gear are sleeved on the outer ring of the rotating shaft.

[0013] Furthermore, it also includes a cover and a first sealing bearing. The end cover is connected to the cover, the rotating shaft is connected to the cover through the first sealing bearing, and the rotating shaft is connected to the housing and the end cover through the second sealing bearing.

[0014] Furthermore, the protruding part of the rotating shaft is provided with a protrusion, and a keyway is provided on the inner side of the bushing. The rotating shaft is connected to the keyway on the inner side of the bushing through the protrusion.

[0015] Furthermore, it also includes a second spur gear, a motor mounting plate, a servo motor, and a first spur gear. The end of the adjusting shaft is connected to the second spur gear, and an opening is provided on the cover. The servo motor is mounted in the first joint through the motor mounting plate, and the first spur gear is mounted on the output shaft of the servo motor. The first spur gear meshes with the second spur gear.

[0016] Compared with the prior art, the present invention has the following advantages: The magnetorheological fluid damper of the present invention is installed in the joint of the robotic arm, making the robotic arm more aesthetically pleasing. The damping element in the magnetorheological fluid damper of the present invention can be mechanically adjusted in size within the cavity of the magnetorheological fluid damper, thereby increasing or decreasing the damping area and realizing the function of partially adjusting the damping precision. The combination of mechanically adjusted damping and electrically controlled magnetorheological fluid damper allows its damping effect to be adjusted according to the needs of the robotic arm. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the three-dimensional structure of the robot of the present invention.

[0018] Figure 2 This is a three-dimensional structural diagram of the robot base and the first joint of the present invention.

[0019] Figure 3 This is a frontal three-dimensional structural diagram of the magnetorheological fluid damper of the present invention.

[0020] Figure 4 This is a three-dimensional structural diagram of the back of the magnetorheological fluid damper of the present invention.

[0021] Figure 5 This is a three-dimensional exploded structural diagram of the magnetorheological fluid damper of the present invention.

[0022] Figure 6 This is a schematic diagram of the internal three-dimensional structure of the magnetorheological fluid damper housing of the present invention.

[0023] Figure 7 This is a three-dimensional structural diagram of the damping adjustment structure of the present invention.

[0024] Figure 8 This is an exploded three-dimensional structural diagram of the damping adjustment structure of the present invention.

[0025] Figure 9 This is an exploded three-dimensional structural diagram of the damping adjustment structure of the present invention.

[0026] Figure 10 This is a three-dimensional structural diagram of the adjusting shaft of the present invention.

[0027] The above-mentioned figures include the following reference numerals: 1. Base, 2. First joint, 3. Second joint, 4. Third joint, 5. Cover, 6. Motor mounting plate, 7. Servo motor, 8. First spur gear, 9. Housing, 901. First through hole, 902. First closed loop, 903. Excitation coil, 904. Second closed loop, 905. Second through hole, 10. End cover, 11. Sealing cover, 12. First sealed bearing, 13. Rotating shaft, 131. Protrusion, 14. Second sealed bearing, 15. Bushing, 151. Keyway, 16. Damping housing, 17. Damping block, 18. Adjusting block, 19. Small bevel gear, 20. Rotating block, 21. Adjusting shaft, 22. Large bevel gear, 23. Inner bearing, 24. Second spur gear. Detailed Implementation

[0028] The preferred technical solution of the present invention will be described in detail below with reference to the accompanying drawings. Example

[0029] A robotic arm with controllable damping, such as Figure 1-10As shown, the robot arm includes a base 1, a first joint 2 on the base 1, a cavity for installing a magnetorheological fluid damper in the first joint 2, the cavity on the first joint 2 is closed by a cover 5, a second joint 3 is connected to the first joint 2, a third joint 4 is connected to the second joint 3, and a magnetorheological fluid damper is installed on each joint of the robot arm.

[0030] The magnetorheological fluid damper includes a housing 9, a first closed loop 902, an excitation coil 903, a second closed loop 904, an end cap 10, a rotating shaft 13, a bushing 15, and a damping adjustment structure. The first closed loop 902 and the second closed loop 904 are provided inside the housing 9. The excitation coil 903 is provided between the housing 9 and the first closed loop 902. The housing 9 is sealed by the end cap 10. The rotating shaft 13 passes through the middle of the housing 9 and the end cap 10. The bushing 15 is provided on the rotating shaft 13. The protruding part of the rotating shaft 13 is provided with a protrusion 131. The bushing 15 has a keyway 151 on its inner side. The rotating shaft 13 is connected to the keyway 151 on the inner side of the bushing 15 through the protrusion 131. The bushing 15 is provided with a damping adjustment structure.

[0031] Magnetorheological fluid is provided in the cavity between the first closed loop 902 and the second closed loop 904. Magnetorheological fluid is also provided between the second closed loop 904 and the bushing 15. The second closed loop 904 has a second through hole 905 for mutual flow of magnetorheological fluid. The housing 9 has a first through hole 901, which is sealed by screws. The magnetorheological fluid flows in the cavity between the first closed loop 902 and the second closed loop 904 and the cavity between the second closed loop 904 and the bushing 15. The magnetorheological fluid in the two cavities exchanges through the first through hole 901.

[0032] The damping adjustment structure includes a damping housing 16, damping blocks 17, adjusting blocks 18, a small bevel gear 19, a rotating block 20, an adjusting shaft 21, a large bevel gear 22, an inner bearing 23, a cover 11, a first sealed bearing 12, a second spur gear 24, a motor mounting plate 6, a servo motor 7, and a first spur gear 8. The damping housing 16 is fixedly connected to the bushing 15. The damping housing 16 has a damping groove. The damping housing 16 contains damping blocks 17 and adjusting blocks 18. The two damping blocks 17 are slidably connected to the damping housing 16. The adjusting block 18 is located between the two damping blocks 17 and is slidably connected to the two damping blocks 17. A rotating block 20 is fixed on the bushing 15. The threaded rod on the small bevel gear 19 passes through the bushing 15 and is rotatably connected to the rotating block 20. The threaded rod is connected to the adjusting block 18, which is wedge-shaped. One end of the adjusting shaft 21 is connected to a large bevel gear 22, and the other end is connected to a second spur gear 24. The adjusting shaft 21 is rotatably connected to the inner side of the bushing 15 through the inner bearing 23. The adjusting shaft 21 and the large bevel gear 22 are sleeved on the outer ring of the rotating shaft 13. The large bevel gear 22 meshes with the small bevel gear 19. The end cover 10 is connected to the sealing cover 11. The rotating shaft 13 is connected to the sealing cover 11 through the first sealing bearing 12. The rotating shaft 13 is connected to the housing 9 and the end cover 10 through the second sealing bearing 14. The sealing cover 11 has an opening. The servo motor 7 is set in the first joint 2 through the motor mounting plate 6. The output shaft of the servo motor 7 is equipped with a first spur gear 8, which meshes with the second spur gear 24.

[0033] When the excitation coil 903 of the magnetorheological fluid damper is energized, a magnetic field is generated. The magnetorheological fluid is subjected to this magnetic field within the sealed cavity of the magnetorheological rotary damper, transforming from a Newtonian fluid without a magnetic field to a Bingham fluid under a strong magnetic field. The suspended particles in the magnetorheological fluid change from magnetic neutrality to strong magnetism, interacting with each other and transforming into a macroscopic columnar structure. This causes the fluid to instantly change from a liquid to a viscoplastic substance, resulting in a change in its rheological properties and exhibiting mechanical properties similar to those of a solid. The magnetorheological fluid undergoes shear flow, causing the damping adjustment structure on the shaft sleeve 15 of the rotating shaft 13 to generate a damping force.

[0034] By adjusting the movement of the damping block 17 to both sides, the friction area of ​​the damping adjustment structure within the cavity of the magnetorheological fluid damper can be adjusted, thereby achieving a more efficient and precise damping effect.

[0035] The damping adjustment structure is adjusted by the servo motor 7 driving the first spur gear 8 and the second spur gear 24 to rotate, thereby driving the adjustment shaft 21 and the large bevel gear 22 to rotate. The large bevel gear 22 drives the small bevel gear to rotate, and the screw on the small bevel gear drives the adjustment block 18 to move. The adjustment block 18 is wedge-shaped, and the adjustment block 18 together with the slider causes the damping block 17 to move, thereby realizing the adjustment function.

[0036] The technical principles of the embodiments of the present invention have been described above with reference to specific examples. These descriptions are merely for explaining the principles of the embodiments of the present invention and should not be construed as limiting the scope of protection of the embodiments of the present invention in any way. Based on the explanation herein, those skilled in the art can conceive of other specific embodiments of the present invention without creative effort, and these embodiments will all fall within the scope of protection of the embodiments of the present invention.

Claims

1. A robotic arm with controllable damping, characterized in that: The robotic arm includes a base with a first joint on the base. A magnetorheological fluid damper is installed inside the first joint. The first joint is connected to a second joint through the magnetorheological fluid damper. An excitation coil is installed inside the magnetorheological fluid damper. The cavity of the magnetorheological fluid damper is filled with magnetorheological fluid. When the excitation coil is energized, the shear yield strength of the magnetic material changes, thereby realizing continuous adjustment of the damping force.

2. The controllable damping robotic arm according to claim 1, characterized in that: The magnetorheological fluid damper includes a housing, a first closed loop, an excitation coil, a second closed loop, an end cover, a rotating shaft, a bushing, and a damping adjustment structure. The first closed loop and the second closed loop are provided inside the housing. The excitation coil is provided between the housing and the first closed loop. The housing is sealed by the end cover. The rotating shaft passes through the middle of the housing and the end cover. The bushing is provided on the rotating shaft, and the damping adjustment structure is provided on the bushing.

3. The controllable damping robotic arm according to claim 2, characterized in that: The robotic arm has multiple joints, and each joint is equipped with a magnetorheological fluid damper.

4. The controllable damping robotic arm according to claim 2, characterized in that: Magnetorheological fluid is provided in the cavities of the first and second closed loops. Magnetorheological fluid is also provided between the second closed loop and the bushing. The second closed loop has a second through hole for mutual flow of magnetorheological fluid. The housing has a first through hole, which is sealed by screws.

5. A controllable damping robotic arm according to claim 2, characterized in that: The damping adjustment structure includes a damping shell, damping blocks, adjusting blocks, a small bevel gear, and a rotating block. The damping shell is fixedly connected to the bushing. The damping blocks and adjusting blocks are provided inside the damping shell. The two damping blocks are slidably connected to the damping shell. The adjusting block is located between the two damping blocks and is slidably connected to the two damping blocks. A rotating block is fixed on the bushing. The threaded rod on the small bevel gear passes through the bushing and is rotatably connected to the rotating block. The threaded rod is threadedly connected to the adjusting block. The adjusting block is wedge-shaped. When the adjusting block moves downward through the threaded rod on the small bevel gear, the two damping blocks move to both sides of the damping shell.

6. The controllable damping robotic arm according to claim 5, characterized in that: The damping housing has damping grooves.

7. A controllable damping robotic arm according to claim 5, characterized in that: The damping adjustment structure also includes an adjustment shaft, a large bevel gear, and an inner bearing. One end of the adjustment shaft is connected to the large bevel gear, which meshes with the small bevel gear. The adjustment shaft is rotatably connected to the inner side of the bushing through the inner bearing. The adjustment shaft and the large bevel gear are sleeved on the outer ring of the rotating shaft.

8. A controllable damping robotic arm according to claim 7, characterized in that: It also includes a cover and a first sealing bearing. The end cover is connected to the cover, the shaft is connected to the cover through the first sealing bearing, and the shaft is connected to the housing and the end cover through the second sealing bearing.

9. A controllable damping robotic arm according to claim 7, characterized in that: The protruding part of the shaft is provided with a protrusion, and a keyway is provided on the inner side of the bushing. The shaft is connected to the keyway on the inner side of the bushing through the protrusion.

10. A controllable damping robotic arm according to claim 7, characterized in that: It also includes a second spur gear, a motor mounting plate, a servo motor, and a first spur gear. The end of the adjusting shaft is connected to the second spur gear. An opening is provided on the cover. The servo motor is mounted in the first joint through the motor mounting plate. The first spur gear is mounted on the output shaft of the servo motor and meshes with the second spur gear.

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