A three-degree-of-freedom wrist joint structure for a rope-driven manipulator

Abstract

The present invention relates to the field of rope-driven mechanical arms. The technical solution is: a three-degree-of-freedom wrist joint structure for rope-driven mechanical arms, characterized in that: the structure includes three motor wheels arranged on a base, a rotary base rotatably positioned on the base, a plurality of pulleys fixed in the base, a transmission shaft rotatably positioned on the rotary base around a horizontal axis, a first winding wheel sleeved and fixed on the rotary shaft, a second winding wheel and a third winding wheel rotatably sleeved on the rotary shaft, a first output wheel and two winding wheels sleeved and fixed on the transmission shaft, a second output wheel rotatably sleeved on the transmission shaft, an end platform connected to a rocker, two winding rings rotatably sleeved on the first rotating shaft of a universal joint, two support rods sleeved on the second rotating shaft of a universal joint, two transmission ropes driving the rotary base, a plurality of transmission ropes driving the rocker, and the remaining plurality of transmission ropes driving the end platform. The present invention can increase the operable space of the mechanical arm.

Description

Technical Field

[0001] The invention relates to the field of rope-driven mechanical arms, and in particular to a three-degree-of-freedom wrist joint structure for rope-driven mechanical arms. Background Art

[0002] In robotics, rope drive is mainly used in the transmission of parallel mechanisms and robot grippers. Rope drive can achieve long-distance transmission, effectively reduce the weight of joints, and achieve lightweight robotic arms. Therefore, research on rope-driven robotic arm technology has received more and more attention and concern.

[0003] In robotics, joints are essential components that connect the robot's hands, arms, body, legs, and feet. Most joints move in rotation or short-distance translation. Among all kinds of joints, the wrist joint has the most complex movement and the most degrees of freedom. In existing rope-driven robotic arm technology, wrist joints are basically two degrees of freedom, and the operating space is limited; therefore, for robots that need to perform continuous operations on curved surfaces in space, such as welding, painting, and concrete spraying in tunneling projects, it is absolutely necessary to have a wrist joint with at least three degrees of rotational freedom. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the above-mentioned background technology and to propose a three-degree-of-freedom wrist joint structure for a rope-driven manipulator to increase the operable space of the manipulator.

[0005] The technical solution adopted by the present invention is:

[0006] A three-degree-of-freedom wrist joint structure for a rope-driven manipulator, characterized in that the structure comprises three motor wheels arranged on a base and driven one by one by motors, a slewing base rotatably positioned on the base through a vertically arranged slewing shaft, a plurality of pulleys fixed one by one in the base through a plurality of mounting plates, a transmission shaft rotatably positioned on the slewing base around a horizontal axis through a bearing seat, a first winding wheel sleeved and fixed on the slewing shaft, a second winding wheel and a third winding wheel rotatably sleeved on the slewing shaft, a first output wheel sleeved and fixed on the transmission shaft, and Two winding wheels, a second output wheel rotatably mounted on the transmission shaft and fixed to the rocker, an end platform connected to the rocker through a universal joint, two winding rings rotatably mounted on the first rotating shaft of the universal joint, two support rods mounted on the second rotating shaft of the universal joint and respectively fixed to the end platform, two transmission ropes wound on the first motor wheel and guided by the pulley and then wound with the first winding wheel to drive the rotating base, a plurality of transmission ropes driven by the second motor wheel to drive the rocker, and the remaining plurality of transmission ropes driven by the third motor wheel to drive the end platform.

[0007] The two winding wheels are respectively the fourth winding wheel and the fifth winding wheel.

[0008] The two transmission ropes driving the rotary base are a first transmission rope and a second transmission rope.

[0009] The method of driving the rocker is as follows: the ninth transmission rope and the tenth transmission rope are respectively wound around the second motor wheel and are respectively wound around the third winding wheel after passing through the pulley; the eleventh transmission rope and the twelfth transmission rope are respectively wound around the third winding wheel and are respectively wound around the second output wheel after passing through the pulley, thereby causing the rocker to swing under the drive of the motor wheel driven by the motor.

[0010] The method of driving the terminal platform is as follows: the third transmission rope and the fourth transmission rope are respectively wound on the third motor wheel and are respectively wound on the second winding wheel after passing through the pulley; the fifth transmission rope and the sixth transmission rope are respectively wound on the second winding wheel and are respectively wound on the first output wheel after passing through the pulley; the seventh transmission rope wound on the fourth winding wheel is wound around the first winding ring and then wound around the first support rod; the eighth transmission rope wound on the fifth winding wheel is wound around the second winding ring and then wound around the second support rod; thereby the driving of the terminal platform is realized.

[0011] The invention has the advantages that, on the basis of the original two-degree-of-freedom wrist joint of the mechanical arm, one more degree of freedom can be added, thereby increasing the operable space of the mechanical arm and enabling the wrist joint to complete all flexion, extension, expansion, retraction and a certain degree of rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is one of the three-dimensional structural schematic diagrams of the present invention.

[0013] Figure 2 The second schematic diagram of the three-dimensional structure of the present invention (relative to Figure 1 rotated 90 degrees).

[0014] Figure 3 for Figure 2 Schematic diagram of the structure from a top-down perspective.

[0015] Figure 4 This is one of the perspective structural diagrams of the interior of the rotating base (after removing the rotating base).

[0016] Figure 5 This is the second perspective structural diagram of the interior of the rotary base ( Figure 1 After removing the swivel base).

[0017] Figure 6 This is the third perspective structural diagram of the interior of the rotary base ( Figure 1 After removing the swivel base).

[0018] Figure 7This is a schematic diagram of the winding structure of one of the motor wheels and the transmission rope at the bottom of the base (the motor is omitted in the figure).

[0019] Numbers in the figure: rotating shaft 1, bottom plate 2, rotating base 3, first transmission rope 4, second transmission rope 5, third transmission rope 6, fourth transmission rope 7, mounting plate 8, fifth transmission rope 9, sixth transmission rope 10, seventh transmission rope 11, first winding ring 12, first support rod 13, eighth transmission rope 14, second winding ring 15, second support rod 16, ninth transmission rope 17, tenth transmission rope 18, eleventh transmission rope 19, twelfth transmission rope 20, rocker 21, transmission shaft 22, bearing cover 23, base 24, end platform 25, universal joint 26, bearing seat 27, fastening retaining ring 28, key 29, bearing 30, motor wheel 31, first winding wheel I, second winding wheel II, third winding wheel III, fourth winding wheel IV, fifth winding wheel V, first output wheel i, second output wheel ii. DETAILED DESCRIPTION

[0020] The present invention is further described below with reference to the embodiments described in the accompanying drawings; however, the present invention is not limited to the following embodiments.

[0021] like Figure 4 , Figure 5 , Figure 6 As shown, the bottom plate 2 is mounted on the inner ring of the bearing 30, the rotary base 3 is mounted on the outer ring of the bearing 30, the bottom is fixed by the bearing cover 23, and the whole is placed on the base 24, and the bottom of the base 24 is equipped with a motor wheel driven by a motor (such as Figure 7 as shown; the motor is omitted in the figure).

[0022] like Figure 7 As shown, the first transmission rope 4 and the second transmission rope 5 are wound in pairs on the motor wheel in the base 24, wherein the first transmission rope 4 is wound on the motor wheel in the forward direction, and the second transmission rope 5 is wound on the motor wheel in the reverse direction (the two transmission ropes are actually one rope connected end to end to form a loop; for the convenience of description, it is divided into two ropes. The same applies hereinafter), and the other two pairs of transmission ropes (the second transmission rope 6 and the third transmission rope 7, the ninth transmission rope 17 and the tenth transmission rope 18) are also wound on the other two motor wheels in the base 24 in the same way (so the other two motor wheels are omitted in the figure).

[0023] like Figure 1 , Figure 2 , Figure 3As shown, a through groove is opened on the rotating base 1 to allow the transmission rope to pass through, the bearing seat 27 is installed on the upper part of the rotating base 3 by screws, and the transmission shaft 22 is installed between the bearing seats 27; the first output wheel i, the fourth winding wheel IV and the fifth winding wheel V are fixedly installed on the transmission shaft 22, and the second output wheel ii is fixedly connected to the rocker 21 and loosely sleeved on the transmission shaft 22; the upper part of the rocker is connected to the first support rod 13 and the second rod support 16 of the terminal platform through a universal joint 26 (the first winding ring 12 and the second winding 15 are sleeved at both ends of the second rotating shaft of the universal joint and are fixed to the first support rod and the second rod support respectively; the upper part of the rocker is hinged to the first rotating shaft of the universal joint 26), and then connected to the terminal platform 25; wherein, the seventh transmission rope wound on the fourth winding wheel can be wound around the first winding ring 12 and then wound around the first support rod 13; similarly, the eighth transmission rope wound on the fifth winding wheel can be wound around the second winding ring 15 and then wound around the second support rod 16.

[0024] like Figure 4 , Figure 5 , Figure 6 As shown, the top end of the rotating shaft 1 is fixed to the upper part of the rotating base 3 by a key 29 and a fastening retaining ring 11; the first winding wheel (I) (omitted in the figure) is fixedly mounted on the rotating shaft 2 and rotates synchronously with the rotating shaft; the second winding wheel (II) and the third winding wheel (III) are loosely mounted on the rotating shaft 2 and are independent of the rotation of the rotating shaft; a plurality of matching pulleys are mounted one by one on the inner wall of the rotating base through a plurality of mounting plates 8 (the bottom of each mounting plate is fixed to the rotating base, and a rotatable pulley is mounted on the top of each mounting plate).

[0025] like Figure 6 , Figure 7 As shown, the first transmission rope 4 and the second transmission rope 5 led out from the first motor wheel are wound on the first winding wheel I (the winding directions of the two ropes are opposite, which are used to realize the forward and reverse rotation of the first winding wheel. Generally, the first transmission rope 4 is wound counterclockwise and the second transmission rope 5 is wound clockwise); after the motor is started, it drives the winding wheel on the motor wheel to rotate, and then drives the rotating shaft 1 to rotate, and the rotating base 3 is rotated through the two transmission ropes.

[0026] like Figure 4As shown, the ninth transmission rope 17 and the tenth transmission rope 18 led out from the second motor wheel respectively pass around the pulleys installed on the mounting plate 8, and then are wound around the third winding wheel III (the ninth transmission rope 17 is wound counterclockwise, and the tenth transmission rope 18 is wound clockwise; as mentioned above, these two ropes are actually connected end to end to form a loop); the eleventh transmission rope 19 led out from the third winding wheel III counterclockwise first passes around the pulley fixed on the rotating base 3, and is wound around the second output wheel ii counterclockwise; then the twelfth transmission rope 20 led out from the third winding wheel III clockwise (as mentioned above, the eleventh transmission rope 19 and the twelfth transmission rope 20 are actually connected end to end to form a loop), successively passes around the pulleys fixed on the rotating base 3, and is wound around the second output wheel ii clockwise; driven by the motor wheel driven by the motor, the second output wheel is driven to rotate, and then the rocker 21 is rotated.

[0027] like Figure 5 , Figure 6 As shown, the third transmission rope 6 and the fourth transmission rope 7 are respectively passed around the pulley fixed on the mounting plate 8, and are wound around the second winding wheel II (the winding directions of the two ropes are opposite; as mentioned above, the two ropes are actually connected end to end to form a loop); then, the fifth transmission rope 9 and the sixth transmission rope 10 are led out from the second winding wheel II (the winding directions of the two ropes are opposite; as mentioned above, the two ropes are actually connected end to end to form a loop), and are respectively passed around the pulley fixed on the rotating base 1, and are wound around the first output wheel i. The winding wheel is still driven by the motor wheel driven by the motor, driving the first output wheel i to rotate.

[0028] like Figure 5 , Figure 6 As shown, the seventh transmission rope 11 led out counterclockwise from the fourth winding wheel IV passes around the first winding ring 12 and is then wound around the first support rod 13; the eighth transmission rope 14 led out clockwise from the fifth winding wheel V passes around the second winding ring 15 and is then wound around the second support rod 16; after the first output wheel i rotates, the fourth winding wheel and the fifth winding wheel are synchronously caused to rotate, thereby driving the first support rod 13 and the second support rod 16 to rotate, causing the end platform 25 to swing around the second rotating shaft of the universal joint.

Claims

1. A three-degree-of-freedom wrist joint structure for a rope-driven manipulator, characterized in that: The structure comprises three motor wheels (31) arranged on a base (24) and driven by motors respectively, a slewing base (1) rotatably positioned on the base via a vertically arranged slewing shaft (2), a plurality of pulleys respectively fixed in the base via a plurality of mounting plates (8), a transmission shaft (22) rotatably positioned on the slewing base around a horizontal axis via a bearing seat (27), a first winding wheel (I) sleeved and fixed on the slewing shaft, a second winding wheel (II) and a third winding wheel (III) rotatably sleeved on the slewing shaft, a first output wheel (i) sleeved and fixed on the transmission shaft, and two a winding wheel, a second output wheel (ii) rotatably mounted on the transmission shaft and fixed to the rocker (21), an end platform (25) connected to the rocker via a universal joint (26), two winding rings rotatably mounted on the first rotating shaft of the universal joint, two support rods mounted on the second rotating shaft of the universal joint and respectively fixed to the end platform, two transmission ropes wound around the first motor wheel and guided by the pulley and then wound around the first winding wheel to cooperate with the driving base, a plurality of transmission ropes driven by the second motor wheel to drive the rocker, and a plurality of other transmission ropes driven by the third motor wheel to drive the end platform; The two winding wheels are respectively a fourth winding wheel (IV) and a fifth winding wheel (V); The two transmission ropes driving the rotary base are a first transmission rope (4) and a second transmission rope (5); The driving method of the rocker is as follows: the ninth transmission rope (17) and the tenth transmission rope (18) are respectively wound around the second motor wheel and are respectively wound around the third winding wheel (III) after passing through the pulley; the eleventh transmission rope (19) and the twelfth transmission rope (20) are respectively wound around the third winding wheel and are respectively wound around the second output wheel (ii) after passing through the pulley, so that the rocker swings under the driving of the motor wheel driven by the motor; The method of driving the terminal platform is as follows: the third transmission rope (6) and the fourth transmission rope (7) are respectively wound around the third motor wheel and are respectively wound around the second winding wheel (II) after passing through the pulley; the fifth transmission rope (9) and the sixth transmission rope (10) are respectively wound around the second winding wheel and are respectively wound around the first output wheel (i) after passing through the pulley; the seventh transmission rope (11) wound around the fourth winding wheel (IV) is wound around the first winding ring (12) and is then wound around the first support rod (13); the eighth transmission rope (14) wound around the fifth winding wheel (V) is wound around the second winding ring (15) and is then wound around the second support rod (16); thereby driving the terminal platform is achieved.

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