Wrist joint wire harness structure of six-axis industrial robot

Abstract

The invention belongs to the technical field of industrial robots, and particularly relates to a wrist joint wire harness structure of a six-axis industrial robot. Comprising a forearm, a wrist joint, a wrist joint supporting sleeve, a six-axis motor and a spiral wire harness, the wrist joint supporting sleeve is fixed to the front end of a forearm side plate of the forearm, the wrist joint is rotationally connected with the wrist joint supporting sleeve, the six-axis motor is arranged on the wrist joint, the spiral wire harness is contained in the wrist joint supporting sleeve, the inner side end of the spiral wire harness is fixed to the wrist joint, and the outer side end of the spiral wire harness is fixed to the forearm side plate. The outer side end of the spiral wire harness is fixed to a forearm side plate and connected with a wrist joint cable led out of an inner cavity of the forearm, and the wrist joint rotates to drive the inner side end of the spiral wire harness to rotate forwards or reversely in the spiral direction. The wire harness layout is simple, the cable reliability and the transmission precision are improved, the sealing performance is better, and the efficiency is higher.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial robots, and particularly relates to a wire harness structure for the wrist joint of a six-axis industrial robot. Background Art

[0002] The wrist joint of a six-axis industrial robot is at the end of a serial mechanism and is a link connecting the forearm and the end flange. The wrist joint requires two rotational degrees of freedom with perpendicular axes, and the structure should at least include two reducers and their respective transmission mechanisms. Therefore, the layout is compact and the space is narrow. In addition, the wrist joint is close to the end load of the robot. In order to improve the performance of the robot, it is often necessary to minimize the weight at this location, and certain application scenarios have special requirements for the sealing performance of the wrist joint.

[0003] Based on the above several problems, the following several solutions are commonly used for the wrist joint of a six-axis industrial robot:

[0004] 1. The motors of the fourth, fifth, and sixth axes of a six-axis industrial robot are arranged at the third axis of the robot, that is, above the upper arm and at the root of the forearm. For the fifth and sixth axis reducers at the wrist joint, the power needs to be transmitted through mechanisms such as spur gears, spline shafts, and bevel gears at the motor location. The cables of the fourth, fifth, and sixth axis motors directly pass through the upper arm and are routed to the base. Although this method places the motors at the rear, reducing the influence of the motors on the weight at the wrist joint and eliminating the need for wiring at the wrist joint, there are obvious deficiencies: the transmission chain is long and there are many components, the cumulative error of transmission accuracy is large, the cumulative loss of transmission efficiency is high, the assembly time is long, the maintenance difficulty is large, and due to the complex transmission, the weight of the wrist joint is not effectively reduced.

[0005] 2. In recent years, with the improvement of motor performance and the update and iteration of reducer technology, lighter and smaller motors have been applied to industrial robots, and hollow reducers with wire routing capabilities have emerged. Thus, another improved structural form and wire routing method have appeared. The fifth and sixth axis motors are moved forward from the third axis of the robot and placed inside the forearm. The fifth axis motor transmits power to the fifth axis reducer through a synchronous belt, and the sixth axis motor transmits power to the sixth axis reducer through a synchronous belt, bevel gear, and spur gear. The cables of the fifth and sixth axis motors are fixed inside the forearm and routed through the fourth axis hollow reducer, and then through the upper arm to the base. This method moves the fifth and sixth axis motors forward, shortening the transmission chain and improving the transmission accuracy and reducing the transmission loss to a certain extent, but there are still disadvantages: arranging two motors and transmission structures inside the forearm cavity increases the size of the forearm; the sixth axis still requires a relatively long transmission chain to transmit power.

[0006] 3. On the basis of the previous solution, the sixth axis motor is further moved forward and installed at the wrist joint, and the motor is directly connected to the reducer or connected through a single-stage spur gear transmission. There are three forms of wire routing for the cable of the sixth axis motor in this solution.

[0007] The first type is directly connected into the forearm along the six-axis axis from outside the wrist joint. The forearm is not sealed, and the wrist joint is not sealed either. The cable is externally placed. The wrist joint is only connected to the five-axis reducer on one side, presenting a cantilever structure.

[0008] This method has the simplest structure and easy wire routing, but obvious defects. The cantilever structure has high requirements for the rigidity of the five-axis reducer, which reduces the load capacity and comprehensive performance of the robot end to a certain extent. The forearm and wrist joint are not sealed, and it cannot prevent the influence of the use environment on the inside of the forearm and the five- and six-axis motors. The cable is externally placed and twists in a wave shape as the five-axis rotates, reducing the service life of the cable. Moreover, the movement range of the cable is large, and it is easy to rub against the pipeline package of the robot end equipment, posing a great safety hazard.

[0009] The second type is that one side of the wrist joint is connected to the five-axis reducer, and the other side is connected to the forearm through a hollow support structure coaxial with the five-axis. Both the wrist joint and the forearm are sealed. The six-axis motor cable enters the forearm and is fixed from the hollow support structure.

[0010] This method takes into account the sealing of the wrist joint and the forearm, leaves a hollow wire routing space for the six-axis motor cable, and both sides of the wrist joint are connected to the forearm, so the overall rigidity is better. However, it has not considered the torsional property of the cable itself. When the five-axis rotates, the cable twists back and forth in the hollow structure. Since the six-axis motor cable includes power lines and encoder cables, the combined wire diameter of these two types of lines is relatively thick, and the width of the wire routing space here far cannot meet the distance requirements of the cable of this specification for the torsional fixing points. Therefore, the service life of the cable is greatly affected and it is easy to break due to torsion.

[0011] The third type, on the basis of the second solution, improves the cable form inside the hollow support structure, and uses a cable in the form of a planar coil spring. The overall radius of the cable coil spring changes with the positive and negative rotation of the five-axis.

[0012] Although this method improves the influence of the five-axis movement on the cable, there are still deficiencies: the cable coil spring is arranged in a plane, and the overall radius changes greatly, increasing the occupied space in the radial direction; it is necessary to design parts such as cable protection plates, profiling clamping blocks, gland covers, etc. to fix the cable, and the accessory structure is relatively complex and the cost is high; there is still torsion of the cable at the center of the coil spring, and the combined wire diameter of the power line and the encoder cable is still relatively thick. The reciprocating torsion reduces the cable life and cannot shield the signal of the encoder cable well; during assembly, the cable needs to be coiled according to the designed length, and a slight error will cause wear of the cable during movement. Summary of the Invention

[0013] In view of the above problems, the purpose of the present invention is to provide a wire harness structure for the wrist joint of a six-axis industrial robot, so as to solve the problems existing in the complexity, reliability, transmission accuracy and sealing performance of the existing robot structure. It can simplify the structure of the wrist joint, improve the reliability of the cable and the transmission accuracy, and has better sealing performance.

[0014] To achieve the above purpose, the present invention adopts the following technical solutions:

[0015] A wire harness structure for the wrist joint of a six-axis industrial robot provided by the present invention includes a forearm, a wrist joint, a wrist joint support sleeve, a six-axis motor and a spiral wire harness. The wrist joint support sleeve is fixed at the front end of the forearm side plate of the forearm. The wrist joint is rotatably connected to the wrist joint support sleeve. The six-axis motor is arranged on the wrist joint. The spiral wire harness is accommodated in the wrist joint support sleeve. The inner end of the spiral wire harness is fixed on the wrist joint and is connected to the direct output wire of the six-axis motor of the six-axis motor. The outer end of the spiral wire harness is fixed on the forearm side plate and is connected to the wrist joint cable led out from the inner cavity of the forearm. When the wrist joint rotates, it drives the inner end of the spiral wire harness to rotate in the positive or negative direction of the spiral.

[0016] The spiral wire harness is composed of a code disk cable spiral and a power cable spiral nested inside and outside, and there is a gap between the code disk cable spiral and the power cable spiral.

[0017] The shape of the spiral wire harness includes a spiral part and straight parts I and II at both ends of the spiral part. The spiral part is accommodated in the wrist joint support sleeve. Straight parts I and II are respectively located outside both ends of the wrist joint support sleeve. Straight part I is connected to the wrist joint through an inner spiral wire bracket. Straight part II is connected to the forearm side plate through an outer spiral wire bracket.

[0018] A wrist joint cable routing cavity is provided on the outer side of the forearm side plate. A cable outer bracket is provided in the wrist joint cable routing cavity. A wrist joint cable connector is provided on the cable outer bracket. One end of the wrist joint cable connector is connected to the spiral wire harness through a cable connection section, and the other end is connected to the wrist joint cable.

[0019] A cable inner bracket is provided in the inner cavity of the forearm. The part of the wrist joint cable located in the inner cavity of the forearm is supported by the cable inner bracket.

[0020] The wrist joint is connected to the wrist joint support sleeve through a deep groove ball bearing of the wrist joint support sleeve. The deep groove ball bearing of the wrist joint support sleeve is axially limited by a hole-type snap ring. The wrist joint and the wrist joint support sleeve are sealed through a rotary oil seal of the wrist joint support sleeve. A wrist joint cover is provided at the rear end of the wrist joint.

[0021] A five-axis reducer positioning sleeve is provided on the wrist joint. The wrist joint support sleeve and the five-axis reducer positioning sleeve are respectively located on both sides of the wrist joint, and their axes are collinear. The five-axis reducer positioning sleeve is used to connect with the output shaft of the five-axis reducer installed on the forearm.

[0022] The output shaft of the six-axis motor is sequentially connected to the six-axis reducer and the end flange.

[0023] The advantages and beneficial effects of the present invention are as follows: A wiring harness structure for the wrist joint of a six-axis industrial robot provided by the present invention has a simple wiring harness layout, improves the reliability of the cable and the transmission accuracy, and has better sealing performance and higher efficiency. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of a wiring harness structure for the wrist joint of a six-axis industrial robot of the present invention;

[0025] Figure 2 is Figure 1 a partial enlarged view at A in

[0026] Figure 3 It is a schematic diagram of the structure of the spiral wiring harness in the present invention;

[0027] Figure 4 It is an axonometric view of the wrist joint of a six-axis industrial robot of the present invention;

[0028] Figure 5 It is a front view of the wrist joint of a six-axis industrial robot of the present invention;

[0029] Figure 6 It is a schematic diagram of the initial state of a wiring harness structure for the wrist joint of a six-axis industrial robot of the present invention;

[0030] Figure 7 It is a schematic diagram of the -125° attitude of the five-axis rotation of a wiring harness structure for the wrist joint of a six-axis industrial robot of the present invention;

[0031] Figure 8 It is a schematic diagram of the +125° attitude of the five-axis rotation of a wiring harness structure for the wrist joint of a six-axis industrial robot of the present invention.

[0032] In the figure: 1 - forearm, 2 - forearm side plate, 3 - wrist joint, 4 - wrist joint support sleeve, 5 - O-ring seal for wrist joint support sleeve, 6 - power cable helix, 7 - encoder cable helix, 8 - direct output line of six-axis motor, 9 - cable connection section, 10 - wrist joint cable, 11 - rotary oil seal for wrist joint support sleeve, 12 - circlip for hole, 13 - deep groove ball bearing for wrist joint support sleeve, 14 - wrist joint cover, 15 - wrist joint cable connector, 16 - outer cable support, 17 - right end cover of forearm, 18 - gasket for right end cover of forearm, 19 - gasket for left end cover of forearm, 20 - left end cover of forearm, 21 - inner cable support, 22 - gasket for wrist joint cover, 23 - O-ring seal for five-axis reducer, 24 - five-axis reducer, 25 - positioning sleeve for five-axis reducer, 26 - gasket for input gear of six-axis reducer, 27 - input gear of six-axis reducer, 28 - rotary oil seal for input gear of six-axis reducer, 29 - six-axis motor, 30 - inner helix bracket, 31 - outer helix bracket, 32 - helix cable bundle, 321 - helix part, 322 - straight part Ⅰ, 323 - straight part Ⅱ. Detailed implementation mode

[0033] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] As Figures 1 to 5 shown, the present invention provides a six-axis industrial robot wrist joint cable bundle structure, including a forearm 1, a wrist joint 3, a wrist joint support sleeve 4, a six-axis motor 29 and a helix cable bundle 32. The wrist joint support sleeve 4 is fixed to the front end of the forearm side plate 2 of the forearm 1 and sealed by an O-ring seal 5 for the wrist joint support sleeve. The wrist joint 3 is rotatably connected to the wrist joint support sleeve 4. The six-axis motor 29 is arranged on the wrist joint 3. The helix cable bundle 32 is accommodated in the wrist joint support sleeve 4. The inner end of the helix cable bundle 32 is fixed to the wrist joint 3 and connected to the direct output line 8 of the six-axis motor 29 of the six-axis motor 29. The outer end of the helix cable bundle 32 is fixed to the forearm side plate 2 and connected to the wrist joint cable 10 led out from the inner cavity of the forearm 1. When the wrist joint 3 rotates, it drives the inner end of the helix cable bundle 32 to rotate in the positive or negative helix direction.

[0035] In an embodiment of the present invention, the output shaft of the six-axis motor 29 is sequentially connected to a six-axis reducer and a terminal flange. Specifically, the output shaft of the six-axis motor 29 is connected to the input gear 27 of the six-axis reducer by an inner hexagon screw, and a gasket 26 for the input gear of the six-axis reducer is installed between the inner hexagon screw and the input gear 27 of the six-axis reducer. The six-axis motor 29 and the wrist joint 3 are connected by an inner hexagon screw, and there is a rotary oil seal 28 for the input gear of the six-axis reducer between the input gear 27 of the six-axis reducer and the wrist joint 3. Through the above structure, the six-axis motor 29 is internally installed in the wrist joint 3, achieving the purpose of simplifying the transmission and reducing the weight of the forearm.

[0036] As Figure 3 shown, in the embodiment of the present invention, the spiral wire harness 32 is composed of a code disc cable spiral 7 and a power cable spiral 6 nested inside and outside, and there is a gap between the code disc cable spiral 7 and the power cable spiral 6. The spiral wire harness 32 separates the power cable and the code disc cable through two sets of three-dimensional and nested spiral wires, avoiding signal interference.

[0037] Specifically, as Figure 2 、 Figure 3 shown, in terms of shape, the spiral wire harness 32 includes a spiral part 321 and straight parts Ⅰ 322 and Ⅱ 323 located at both ends of the spiral part 321. The spiral part 321 is accommodated in the wrist joint support sleeve 4, and the straight parts Ⅰ 322 and Ⅱ 323 are respectively located outside both ends of the wrist joint support sleeve 4. The straight part Ⅰ 322 is connected to the wrist joint 3 through the inner spiral wire bracket 30, and the straight part Ⅱ 323 is connected to the small arm side plate 2 through the outer spiral wire bracket 31. The spiral wire harness 32 is fixed at only two points where the spiral part 321 is tangent to the straight part. During the five-axis rotational movement, there is no rubbing between the inner and outer loop cables, no rubbing between the outer loop cable and the surrounding components, and the change range of the loop diameter is very small.

[0038] Furthermore, as Figure 1 shown, there is a wrist joint cable routing cavity on the outer side of the small arm side plate 2. There is a cable outer bracket 16 in the wrist joint cable routing cavity, and a wrist joint cable connector 15 is provided on the cable outer bracket 16. One end of the wrist joint cable connector 15 is connected to the spiral wire harness 32 through the cable connection section 9, and the other end is connected to the wrist joint cable 10. There is a cable inner bracket 21 in the inner cavity of the small arm 1, and the part of the wrist joint cable 10 located in the inner cavity of the small arm 1 is supported by the cable inner bracket 21.

[0039] In the embodiment of the present invention, the wrist joint 3 is connected to the wrist joint support sleeve 4 through the wrist joint support sleeve deep groove ball bearing 13. The wrist joint support sleeve deep groove ball bearing 13 is axially limited by the hole retaining snap ring 12. The wrist joint 3 and the wrist joint support sleeve 4 are sealed through the wrist joint support sleeve rotary oil seal 11. There is a wrist joint cover 14 at the rear end of the wrist joint 3, and it is sealed through the wrist joint cover gasket 22.

[0040] Furthermore, a five-axis reducer positioning sleeve 25 is provided on the wrist joint 3. The wrist joint support sleeve 4 and the five-axis reducer positioning sleeve 25 are respectively located on both sides of the wrist joint 3, and their axes are collinear. The five-axis reducer positioning sleeve 25 is used to position the output shaft of the five-axis reducer 24 installed on the forearm 1. This side serves as the main support side of the wrist joint. On the other side of the wrist joint 3, a deep groove ball bearing 13 for the wrist joint support sleeve, a circlip for hole 12, and a rotary oil seal 11 for the wrist joint support sleeve are installed. The wrist joint support sleeve 4 passes through the lip of the rotary oil seal 11 for the wrist joint support sleeve and is assembled into the inner ring of the deep groove ball bearing 13 for the wrist joint support sleeve. At the same time, the wrist joint support sleeve 4 and the forearm side plate 2 are connected by hexagon socket head cap screws, and an O-ring 5 for the wrist joint support sleeve is installed between them. This side serves as the auxiliary support side of the wrist joint. The forearm 1 and the forearm side plate 2 are connected by hexagon socket head cap screws, and the wrist joint 3 is respectively connected to the forearm 1 and the forearm side plate 2. In this way, there is support on both sides, which effectively improves the rigidity and accuracy of the robot end compared with single-sided cantilever support. As Figure 4 , Figure 5 shown, the two sides of the wrist joint 3 have an asymmetric structure.

[0041] The present invention provides a wiring harness structure for a six-axis industrial robot wrist joint, and its motion principle is:

[0042] The power cable helix 6 and the encoder cable helix 7 are nested and installed together. As Figure 3 shown, both have a helix part and a straight segment part, and a cable running space is reserved between the power cable helix 6 and the encoder cable helix 7. The power cable and the encoder cable of the six-axis motor 29 are connected through the direct output line 8 of the six-axis motor, the power cable helix 6, and the encoder cable helix 7, and at the tangent point of the straight segment and the helix, a cable fixing bracket I 30 is used to fix the cable. On the other side, the wrist joint cable connector 15 is connected to the power cable helix 6 and the encoder cable helix 7 through the cable connection section 9, and at the tangent point of the straight segment and the helix, a cable fixing bracket II 31 is used to fix the cable. The power cable helix 6 and the encoder cable helix 7 pass through the wrist joint support sleeve 4 and only contact the cable fixing bracket I 30 and the cable fixing bracket II 31 at the tangent points on both sides, and a cable running space is reserved between them and the wrist joint support sleeve 4.

[0043] As Figure 6As shown, when the five-axis is in the 0° attitude, it is the initial installation state of the spiral wire harness 32. At this time, there is no resilience inside the spiral wire harness 32. The wire diameter of the power cable spiral 6 is 8.1 mm, the lead is 9.5 mm, the number of turns is 5.5 turns, the total rotation angle is 1980°, the total thickness is 62 mm, and the inner diameter of the coil is 42 mm; the wire diameter of the encoder cable spiral 7 is 6.7 mm, the lead is 8 mm, the number of turns is 6.5 turns, the total rotation angle is 2340°, the total thickness is 60 mm, and the outer diameter of the coil is 36.7 mm; at this time, the wire diameter of the power cable spiral 6, 8.1 mm, is less than the lead of 9.5 mm, and there is no rubbing between adjacent turns of itself; the wire diameter of the encoder cable spiral 7, 6.7 mm, is less than the lead of 8 mm, and there is no rubbing between adjacent turns of itself; the inner diameter of the coil of the power cable spiral 6, 42 mm, is greater than the outer diameter of the coil of the encoder cable spiral 7, 36.7 mm, and there is a certain space between the two, so there is no rubbing either.

[0044] As Figure 7 shown, when the five-axis is in the -125° attitude, it is the negative limit position of the five-axis. At this time, the spiral wire harness 32 rotates inward and tightens. The wire diameter of the power cable spiral 6 remains 8.1 mm, the lead changes to 9.2 mm, the number of turns is 5.85 turns, the total rotation angle is 2105°. Since both sides are fixed to the spiral bracket at the tangent points, the total thickness of 62 mm remains unchanged, and the inner diameter of the coil is 39 mm; the wire diameter of the encoder cable spiral 7 remains 6.7 mm, the lead changes to 7.8 mm, the number of turns is 6.85 turns, the total rotation angle is 2465°. Since both sides are fixed to the spiral bracket at the tangent points, the total thickness of 60 mm remains unchanged, and the outer diameter of the coil is 35.2 mm; at this time, the wire diameter of the power cable spiral 6, 8.1 mm, is less than the lead of 9.2 mm, and there is no rubbing between adjacent turns of itself; the wire diameter of the encoder cable spiral 7, 6.7 mm, is less than the lead of 7.8 mm, and there is no rubbing between adjacent turns of itself; the inner diameter of the coil of the power cable spiral 6, 39 mm, is greater than the outer diameter of the coil of the encoder cable spiral 7, 35.2 mm, and there is a certain space between the two, so there is no rubbing.

[0045] As Figure 8As shown in the figure, when the fifth axis is in the +125° posture, it is the positive limit position of the fifth axis. At this time, the spiral wire harness 32 rotates outward and becomes loose. The wire diameter of the power cable spiral 6 is 8.1 mm and remains unchanged. The lead changes to 10.4 mm, the number of turns is 5.15 turns, and the total rotation angle is 1855°. Since both sides are fixed to the spiral bracket at the tangent points respectively, the total thickness of 62 mm remains unchanged, and the inner diameter of the coil is 45.3 mm; the wire diameter of the encoder cable spiral 7 is 6.7 mm and remains unchanged. The lead changes to 8.7 mm, the number of turns is 6.15 turns, and the total rotation angle is 2215°. Since both sides are fixed to the spiral bracket at the tangent points respectively, the total thickness of 60 mm remains unchanged, and the outer diameter of the coil is 38.3 mm; at this time, the wire diameter of the power cable spiral 6 of 8.1 mm is less than the lead of 10.4 mm, and there is no rubbing between adjacent turns of itself; the wire diameter of the encoder cable spiral 7 of 6.7 mm is less than the lead of 8.7 mm, and there is no rubbing between adjacent turns of itself; the inner diameter of the coil of the power cable spiral 6 of 45.3 mm is greater than the outer diameter of the coil of the encoder cable spiral 7 of 38.3 mm, and there is a certain space between the two, so there is no rubbing.

[0046] The present invention uses a test platform to conduct reciprocating running tests of the wire harness at ±125°, with an interval of 1 s. 3 million tests have been carried out. After the tests, the cables are removed for inspection, and there is no wear. The resistance values of each core in the cables are measured and are all normal.

[0047] Sealing introduction: The motor and wire harness of the present invention are completely arranged in the small arm 1, the small arm side plate 2 and the wrist joint 3, providing a prerequisite for the sealing of the wrist joint. The main sealing of the present invention is ensured by the following items: The six-axis reducer input gear sealing gasket 26 and the six-axis reducer input gear rotary oil seal 28 are used for sealing between the wrist joint 3 and the six-axis motor 29; the five-axis reducer O-ring 23 and end face sealant are used for sealing between the wrist joint 3 and the five-axis reducer 24; the wrist joint support sleeve rotary oil seal 11 is used for sealing between the wrist joint 3 and the wrist joint support sleeve 4; the wrist joint cover gasket 22 is used for sealing between the wrist joint 3 and the wrist joint cover 14; the five-axis reducer 24 and the small arm 1 rely on the built-in sealing ring of the reducer for sealing; the small arm left end cover gasket 19 is used for sealing between the small arm 1 and the small arm left end cover 20; the end face sealant is used for sealing between the small arm 1 and the small arm side plate 2; the small arm right end cover gasket 18 is used for sealing between the small arm side plate 2 and the small arm right end cover 17; the wrist joint support sleeve O-ring 5 is used for sealing between the small arm side plate 2 and the wrist joint support sleeve 4.

[0048] In the present invention, the power cable spiral 6 and the encoder cable spiral 7 are prefabricated in advance according to the wire-making data and are directly fixed on the spiral brackets I 30 and spiral brackets II 31 on both sides, without manual on-site bending and installation. The cables between the spiral and the motor and the small arm are connected using connectors. The maintenance can be carried out by removing the small arm right end cover 17 and the wrist joint cover 14, which is convenient and fast.

[0049] The present invention provides a wire harness structure for the wrist joint of a six-axis industrial robot, which can simplify the structure of the wrist joint, improve the reliability of the cables and the transmission accuracy, and has better sealing performance. The six-axis motor and the six-axis reduction gear are driven by spur gears, the intermediate bevel gear drive form is cancelled, and a three-dimensional and nested spiral is provided at the rotation center of the fifth axis. By using this spiral, the power cable of the six-axis motor and the encoder cable are connected to the cables inside the forearm to complete the routing of the body. This wire harness form has passed 3 million times of reliability tests, and the resistance values of each wire core of the inner and outer circle cables are all normal.

[0050] The wire harness structure for the wrist joint of a six-axis industrial robot provided by the present invention realizes that the six-axis motor is built in the wrist joint, simplifies the structure of the wrist joint, improves the rigidity of the wrist joint, improves the reliability of the cables and the transmission accuracy, ensures the sealing performance of the wrist joint, has a simple assembly process, is convenient for later maintenance, and reduces the product cost.

[0051] The above are only the embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, expansions, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A wiring harness structure for the wrist joint of a six-axis industrial robot, characterized in that, It includes a forearm (1), a wrist joint (3), a wrist joint support sleeve (4), a six-axis motor (29) and a spiral wire harness (32). The wrist joint support sleeve (4) is fixed to the front end of the forearm side plate (2) of the forearm (1). The wrist joint (3) is rotatably connected to the wrist joint support sleeve (4). The six-axis motor (29) is arranged on the wrist joint (3). The spiral wire harness (32) is accommodated in the wrist joint support sleeve (4). The inner end of the spiral wire harness (32) is fixed to the wrist joint (3) and is connected to the six-axis motor direct outgoing wire (8) of the six-axis motor (29). The outer end of the spiral wire harness (32) is fixed to the forearm side plate (2) and is connected to the wrist joint cable (10) led out from the inner cavity of the forearm (1). When the wrist joint (3) rotates, it drives the inner end of the spiral wire harness (32) to rotate in the positive or negative spiral direction.

2. The six-axis industrial robot wrist joint wire harness structure according to claim 1, characterized in that The spiral wire harness (32) is composed of a code disk cable spiral (7) and a power cable spiral (6) nested inside and outside, and there is a gap between the code disk cable spiral (7) and the power cable spiral (6).

3. The six-axis industrial robot wrist joint wire harness structure according to claim 1 or 2, characterized in that, The shape of the spiral wire harness (32) includes a spiral part (321) and straight parts Ⅰ (322) and Ⅱ (323) located at both ends of the spiral part (321). The spiral part (321) is accommodated in the wrist joint support sleeve (4). The straight part Ⅰ (322) and the straight part Ⅱ (323) are respectively located outside both ends of the wrist joint support sleeve (4). The straight part Ⅰ (322) is connected to the wrist joint (3) through an inner spiral wire bracket (30), and the straight part Ⅱ (323) is connected to the forearm side plate (2) through an outer spiral wire bracket (31).

4. The wire harness structure of the six-axis industrial robot wrist joint according to claim 1, characterized in that, A wrist joint cable routing cavity is provided on the outer side of the forearm side plate (2). A cable outer bracket (16) is provided in the wrist joint cable routing cavity. A wrist joint cable connector (15) is provided on the cable outer bracket (16). One end of the wrist joint cable connector (15) is connected to the spiral wire harness (32) through a cable connection section (9), and the other end is connected to the wrist joint cable (10).

5. The six-axis industrial robot wrist joint wire harness structure according to claim 4, characterized in that, A cable inner bracket (21) is provided in the inner cavity of the forearm (1). The part of the wrist joint cable (10) located in the inner cavity of the forearm (1) is supported by the cable inner bracket (21).

6. The six-axis industrial robot wrist joint wire harness structure according to claim 1, wherein The wrist joint (3) is connected to the wrist joint support sleeve (4) through a wrist joint support sleeve deep groove ball bearing (13). The wrist joint support sleeve deep groove ball bearing (13) is axially limited by a hole retaining snap ring (12). A wrist joint support sleeve rotary oil seal (11) is provided between the wrist joint (3) and the wrist joint support sleeve (4). A wrist joint cover (14) is provided at the rear end of the wrist joint (3).

7. The six-axis industrial robot wrist joint wire harness structure according to claim 1, characterized in that, A five-axis reducer positioning sleeve (25) is provided on the wrist joint (3). The wrist joint support sleeve (4) and the five-axis reducer positioning sleeve (25) are respectively located on both sides of the wrist joint (3) and have collinear axes. The five-axis reducer positioning sleeve (25) is used to connect to the output shaft of a five-axis reducer (24) installed on the forearm (1).

8. The six-axis industrial robot wrist joint wire harness structure according to claim 1, characterized in that, The output shaft of the six-axis motor (29) is sequentially connected to a six-axis reducer and an end flange.

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