Speed reducer applied to robot joint

Abstract

The invention provides a speed reducer applied to a robot joint. An input shaft is fixedly connected with a first-stage sun gear, the first-stage sun gear is in meshed connection with a plurality of first planet gears, the first planet gears are meshed with an inner gear box, the inner walls of the first planet gears are rotationally connected with first roller pin shafts, and the first roller pin shafts are rotationally connected with first-stage planet carriers; a first bearing is arranged between the input shaft and the first-stage planet carrier, a second bearing is arranged between the first-stage planet carrier and the inner gear box, the first bearing is located in the second bearing, the end of the first-stage planet carrier is fixedly connected with a second-stage sun gear, and the tooth portion of the second-stage sun gear is connected with a second planet gear in a meshed mode. A second roller pin shaft is fixedly connected to the inner wall of the second planet wheel, a second-stage planet carrier is rotationally connected to the second roller pin shaft, the second planet wheel is meshed with the inner gear box, and the second-stage planet carrier is connected with the output shaft, so that the overall length is shortened, the structure is more compact, and the trend requirements of miniaturization and light weight of the robot are met.

Description

Technical Field

[0001] The invention relates to the field of robot accessories, in particular to a reducer applied to a robot joint. Background Art

[0002] Robots are the key direction of future development in the mechanical field.

[0003] The joints of a robot are usually driven by a motor and a reducer to rotate, so that the joints have a large rotational torque and are easy to adjust the rotation angle of the joints.

[0004] At present, a Chinese patent with authorization announcement number CN203779520U discloses an industrial robot joint reducer, including a fixed seat, a bearing seat, a No. 1 A-type flat key, a transmission shaft, a harmonic reducer and a cross-roller bearing. The harmonic reducer includes a wave generator, a flexible wheel and a steel wheel. The No. 1 A-type flat key is arranged at the head end of the transmission shaft, and the end of the transmission shaft transmits the rotational power to the wave generator through the No. 2 A-type flat key. When the wave generator rotates, the flexible wheel is meshed with the steel wheel. The flexible wheel is connected to the inner ring of the cross-roller bearing through the outer bearing pressure plate arranged on the bearing seat, and the outer ring of the cross-roller bearing is fixed to the fixed seat through the front bearing sleeve.

[0005] This industrial robot joint reducer organically combines the harmonic reducer and the crossed roller bearing. By optimizing the external mounting dimensions, it can directly replace the imported reducer for use in the terminal joints of industrial robots. It has the advantages of large speed ratio, high transmission efficiency, good rigidity, small backlash, small size and low cost.

[0006] However, the overall length of this type of industrial robot joint reducer is relatively long, which cannot adapt to the trend of robot miniaturization, especially the arm joints of humanoid robots. Summary of the invention

[0007] In view of this, an object of the present invention is to provide a reducer applied to robot joints, which shortens the overall length and has a more compact structure to meet the trend of miniaturization and lightweight of robots.

[0008] In order to solve the above technical problems, the technical solution of the present invention is: a reducer applied to a robot joint, comprising an internal gear box, an output shaft, an input connecting flange and an input shaft, the input shaft is fixed to the inner wall of the input connecting flange, a primary sun gear is fixedly connected to the input shaft, the primary sun gear is meshedly connected to a plurality of first planetary gears, the first planetary gears are meshed with the internal gear box, a first needle roller shaft is rotatably connected to the inner wall of the first planetary gear, a primary planetary carrier is rotatably connected to the first needle roller shaft, a first bearing is arranged between the input shaft and the primary planetary carrier, a second bearing is arranged between the primary planetary carrier and the internal gear box, the first bearing is located inside the second bearing, a secondary sun gear is fixedly connected to the end of the primary planetary carrier, the tooth portion of the secondary sun gear is meshedly connected to the second planetary gear, a second needle roller shaft is fixedly connected to the inner wall of the second planetary gear, a secondary planetary carrier is rotatably connected to the second needle roller shaft, the second planetary gear is meshed with the internal gear box, and the secondary planetary carrier is connected to the output shaft.

[0009] To implement the above technical solution, the input shaft and the input connecting flange rotate synchronously, the input shaft drives the first-stage sun gear to rotate, and the first-stage sun gear drives the first planetary gear to rotate, while the first planetary gear and the first needle roller shaft move along the axis of the first-stage planetary carrier, the first-stage planetary carrier rotates, and the first-stage planetary carrier drives the second-stage sun gear to rotate. The first-stage planetary carrier is fixedly connected to the second-stage sun gear, thereby further shortening the length, and the second-stage sun gear rotates the second planetary gear and makes the second planetary gear rotate along the axis of the second-stage sun gear, and the second-stage planetary carrier rotates synchronously with the second planetary gear, so that the output shaft rotates with the second-stage planetary carrier. At this time, the output shaft has a slower rotation speed and a greater torque, and the first bearing is located inside the second bearing, so that the overall length can be greatly shortened, and the structure is more compact, which meets the trend of miniaturization of robots.

[0010] As a preferred solution of the present invention, a mounting plate is fixedly connected to the outer wall of the inner gear box, a cross roller bearing is arranged inside the mounting plate, an output flange is connected to the outer wall of the secondary planetary carrier, the output flange is connected to the cross roller bearing, and the secondary sun gear and the second planetary gear are both located inside the cross roller bearing.

[0011] To implement the above technical solution, the mounting plate is used to facilitate fixing on the robot, and the cross roller bearing enables the secondary planetary carrier to rotate smoothly with lower noise; since the secondary sun gear is located inside, the structure is more compact.

[0012] As a preferred solution of the present invention, an outer pressure plate is fixedly connected to the end of the mounting plate, and the outer pressure plate is used to press against the side wall of the cross roller bearing.

[0013] Implementing the above technical solution makes the placement of the crossed roller bearing more stable.

[0014] As a preferred solution of the present invention, a limiting sleeve is provided on the outer wall of the mounting plate, a limiting groove for placing cables is opened on the inner wall of the limiting sleeve, the length direction of the limiting groove is parallel to the axial direction of the limiting sleeve, and the limiting sleeve is connected to the outer wall of the output shaft through a connecting rod.

[0015] To implement the above technical solution, a limit groove is opened on the inner wall of the limit sleeve, and the cable is inserted into the limit groove. During the rotation of the output shaft, the limit sleeve rotates synchronously with the output shaft, making it difficult for the cable to get tangled, minimizing cable torsion and bending, and improving the life and reliability of the cable.

[0016] As a preferred solution of the present invention, a sliding groove is provided on the inner wall of the limiting groove, the sliding groove is close to the end of the limiting groove, a support shaft is slidably connected in the sliding groove, a limiting wheel is rotatably connected to the support shaft, an annular groove for interfering with the outer wall of the cable is provided on the outer circular surface of the limiting wheel, and a first elastic member is connected between the support shaft and the inner wall of the sliding groove.

[0017] To implement the above technical solution, the cable is passed through the limiting sleeve and embedded in the limiting groove. The outer wall of the cable contacts the annular groove on the limiting wheel. When the cable moves along the length direction of the limiting groove, the wear of the cable is reduced. The elastic force of the first elastic member makes it difficult for the limiting wheel and the cable to separate.

[0018] As a preferred solution of the present invention, a storage groove for placing cables is provided on the inner wall of the limiting sleeve, the storage groove is connected to the middle part of the limiting groove, a baffle is fixedly connected to the side of the storage groove facing the mounting plate, an installation cavity opposite to the storage groove is provided on the inner wall of the limiting groove, a sliding rod for pushing the cable into the storage groove is slidably connected to the inner wall of the mounting cavity, a second elastic member is connected between the sliding rod and the inner wall of the mounting cavity, and a linkage component for interfering with the sliding rod is provided on the outer wall of the mounting plate.

[0019] To implement the above technical solution, during the process of joint extension, relative rotation occurs between the limit sleeve and the mounting disk, the linkage assembly contacts the slide rod, causing the slide rod to move along its own length direction, and causing the slide rod to push some excess cables into the storage slot, so that there are more cables in the limit sleeve, making the cables more compact on the robot to enhance the protection of the cables; during the process of joint folding, relative rotation occurs between the limit sleeve and the mounting disk, causing the linkage assembly to separate from the slide rod, and the slide rod is reset by the elastic force of the second elastic member, so that excess cables can be moved out of the limit sleeve to avoid the cables being broken.

[0020] As a preferred solution of the present invention, the linkage assembly includes a telescopic rod, a pressure wheel, a straight groove, an anti-slip rod, a first inclined surface and a second inclined surface. The telescopic rod is fixed to the outer wall of the mounting plate, the pressure wheel is rotatably connected to the telescopic rod, the straight groove is opened on the inner wall of the limiting sleeve and is connected to the mounting cavity, the anti-slip rod is slidably connected to the straight groove, the first inclined surface is opened at the end of the sliding rod, the second inclined surface is opened at the end of the anti-slip rod, the first inclined surface is maintained in conflict with the second inclined surface, and the pressure wheel is rollingly connected to the inner wall of the limiting sleeve or rollingly connected to the end of the anti-slip rod away from the second inclined surface.

[0021] To implement the above technical solution, the limiting sleeve rotates with the output shaft, and relative rotation occurs between the limiting sleeve and the mounting plate. The pressure wheel presses on the anti-slip rod, and the anti-slip rod moves along the length direction of the straight groove. The guiding effect of the first inclined surface and the second inclined surface makes the slide bar move along its own length direction, so that the slide bar pushes the cable to move, so that the excess cable can be moved into the storage groove; after the pressure wheel is separated from the anti-slip rod, the slide bar is reset by the elastic force of the second elastic member, and the anti-slip rod is reset by the guiding effect of the first inclined surface and the second inclined surface. At this time, the slide bar cannot exert pressure on the cable, so that the excess cable can be moved out of the limiting sleeve.

[0022] As a preferred solution of the present invention, the side wall of the limiting wheel is provided with an oil storage cavity for storing lubricating oil, the side wall of the oil storage cavity is provided with an oil outlet hole connected with the annular groove, a plunger is provided on the oil outlet hole, and the plunger blocks the oil outlet hole by a tension spring. When the limiting wheel rotates, the lubricating oil is discharged from the oil outlet hole by the action of centrifugal force and then coated on the outer wall of the cable.

[0023] To implement the above technical solution, when the cable drives the limiting wheel to roll due to the friction force, the plunger is separated from the oil outlet hole due to the action of centrifugal force, and a small amount of lubricating oil is discharged from the oil outlet hole and coated on the outer wall of the cable, thereby reducing cable wear and enhancing the protection of the cable; when the cable stops driving the limiting wheel to rotate, and when the limiting wheel rotates at a slow speed, the plunger blocks the oil outlet hole due to the elastic force of the tension spring, so as to save the use of lubricating oil.

[0024] In summary, the present invention has the following beneficial effects: 1. Combine the bearing seat with the internal gear box to make the structure more compact and reasonable to meet the needs; 2. Insert the cables into the limit grooves. During the rotation of the joint, the limit sleeves rotate synchronously with the joints, so that multiple cables move synchronously. Thus, it is not easy for multiple cables to get tangled or entangled, thereby improving the protection of the cables. 3. During the joint extension process, the output shaft rotates, and the limit sleeve and the mounting plate rotate relative to each other. The excessively long cable is pressed into the storage slot by the slide rod, shortening the cable length outside the limit sleeve; during the joint folding process, when the joint is folded, the pressure wheel is separated from the anti-drop rod, and the second elastic member pushes the slide rod to reset, and the excess cable can be released from the storage slot; thereby, the cables are prevented from accumulating near the joint, or even entangled with other cables or robot structures, causing chaos; loose cables may swing during the joint movement, collide or interfere with the robot itself or other objects, and affect the normal movement of the robot. Cable retraction and release can effectively avoid the occurrence of such problems, making the structure more compact and reasonable; 4. When the cable is pushed into the storage tank and pulled out from the storage tank, the cable drives the limiting wheel to rotate through the action of friction, and the plunger is separated from the oil outlet hole through the action of centrifugal force. The lubricating oil is discharged from the oil outlet hole and coated on the outer wall of the cable to further reduce the wear on the cable; when the limiting wheel rotates slowly or stops rotating, the plunger blocks the oil outlet hole through the elastic force of the tension spring to save the use of lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional schematic diagram of the internal gear box; Figure 2 This is a schematic diagram of the front structure of the input connection flange; Figure 3 It is the front structural diagram of the output shaft; Figure 4 It is a structural schematic diagram of the limit sleeve; Figure 5 for Figure 4 A magnified view of; Figure 6 A schematic diagram showing the location of the storage tank; Figure 7 A schematic diagram showing the position of the anti-drop rod; Figure 8 A schematic cross-sectional view showing an anti-drop rod; Fig. 9 A schematic cross-sectional view showing a telescopic rod; Fig.10 It is a structural schematic diagram of the sliding bar; Fig.11 is a schematic cross-sectional view of a limiting wheel; Fig.12 It is a schematic diagram of the longitudinal section of the limiting wheel.

[0026] Figure numerals: 10, internal gear box; 11, input connecting flange; 13, primary sun gear; 14, first bearing; 15, primary planet carrier; 16, second bearing; 17, first planet gear; 18, first needle roller shaft; 2, secondary reduction assembly; 21, secondary planet carrier; 22, secondary sun gear; 23, second planet gear; 24, output shaft; 25, second needle roller shaft; 3, mounting plate; 31, cross roller bearing; 32, outer pressure plate; 33, output flange; 34, inner pressure plate; 4, limiting sleeve; 41, connecting rod; 5, limiting groove; 51, slide groove; 52, slider; 53, support shaft; 54, first An elastic member; 55, a limiting wheel; 56, an annular groove; 6, an elastic plate; 7, a storage groove; 71, a baffle; 8, a mounting cavity; 81, a sliding rod; 811, an arc-shaped groove; 82, a second elastic member; 83, a T-shaped rod; 9, a linkage assembly; 91, a telescopic rod; 911, a sleeve; 912, an inner rod; 913, a third elastic member; 92, a pressure wheel; 93, a straight groove; 94, an anti-slip rod; 95, a first inclined plane; 96, a second inclined plane; 100, a cable; 200, an oil storage cavity; 201, a cover plate; 202, an oil outlet hole; 203, a plunger; 204, a support rod; 205, an anti-slip sheet; 206, a tension spring. DETAILED DESCRIPTION

[0027] The specific implementation modes of the present invention are further described below in conjunction with the accompanying drawings to make the technical solutions of the present invention easier to understand and grasp.

[0028] A reducer applied to a robot joint comprises an internal gear box 10, an output shaft 24, an input connection flange 11 and an input shaft. The input shaft is fixed to the inner wall of the input connection flange 11, and the input shaft and the input connection flange 11 are fixedly connected.

[0029] A primary sun gear 13 is fixedly connected to the outer wall of the input shaft, and the primary sun gear 13 extends into the inner part of the internal gear box 10. The primary sun gear 13 is meshed with a first planetary gear 17, and three first planetary gears 17 are evenly distributed along the axis of the primary sun gear 13. The first planetary gear 17 meshes with the inner gear ring of the internal gear box 10.

[0030] The first needle roller shaft 18 is rotatably connected to the inner wall of the first planetary gear 17, and the first needle roller shaft 18 is coaxially arranged with the first planetary gear 17. The first needle roller shaft 18 is rotatably connected to the primary planet carrier 15, and the primary planet carrier 15 is connected to the output shaft 24 through the secondary reduction assembly 2. The output shaft 24 is located outside the inner gear box 10.

[0031] A first bearing 14 is connected between the input shaft and the primary planet carrier 15, and a second bearing 16 is connected between the primary planet carrier 15 and the internal gear box 10. The first bearing 14 is located inside the second bearing 16. Both the first bearing 14 and the second bearing 16 are deep groove ball bearings.

[0032] The secondary reduction assembly 2 includes a secondary planet carrier 21, a secondary sun gear 22 and three second planetary gears 23. The end of the primary planet carrier 15 is fixedly connected to the end of the secondary sun gear 22, and the primary planet carrier 15 is coaxially arranged with the secondary sun gear 22. The tooth portion of the secondary sun gear 22 is meshed with the second planetary gear 23, and a second needle roller shaft 25 is fixedly connected to the inner wall of the second planetary gear 23, and the second needle roller shaft 25 is rotatably connected to the secondary planet carrier 21, and the second planetary gear 23 is meshed with the inner gear ring of the internal gear box 10. The secondary planet carrier 21 is fixedly connected to the output shaft 24 and the secondary planet carrier 21 is coaxially arranged with the output shaft 24.

[0033] The mounting plate 3 is fixedly connected to the outer wall of the inner gear box 10 by bolts, a cross roller bearing 31 is arranged on the inner wall of the mounting plate 3, and an output flange 33 is fixedly connected to the outer wall of the secondary planet carrier 21, and the output flange 33 is connected to the cross roller bearing 31. In order to make the cross roller bearing 31 more stably placed, the output flange 33 is fixedly connected to the inner pressure plate 34 by bolts, and the inner pressure plate 34 is connected to the cross roller bearing 31. The inner pressure plate 34 is located inside the mounting plate 3.

[0034] An outer pressure plate 32 is fixedly connected to the end of the mounting plate 3, and the outer pressure plate 32 is used to press against the side wall of the cross roller bearing 31 to achieve complete fixation of the cross roller bearing 31. An oil seal is provided between the outer pressure plate 32, the cross roller bearing 31 and the output flange 33.

[0035] A limiting sleeve 4 is provided on the outer wall of the mounting plate 3, and a cavity is provided between the limiting sleeve 4 and the mounting plate 3. A limiting groove 5 for placing the cable 100 is provided on the inner wall of the limiting sleeve 4, and the length direction of the limiting groove 5 is parallel to the axial direction of the limiting sleeve 4. The limiting sleeve 4 is connected to the outer wall of the output shaft 24 through a connecting rod 41. During the rotation of the output shaft 24, the limiting sleeve 4 is caused to rotate synchronously with the output shaft 24 through the connecting rod 41.

[0036] A slide groove 51 is provided on the inner wall of the limiting groove 5. The slide groove 51 is close to the end of the limiting groove 5. A slider 52 is slidably connected in the slide groove 51. A cylindrical straight rod is fixedly connected to the inner wall of the slide groove 51. The straight rod is slidably connected to the slider 52 so that the slider 52 slides along the length direction of the slide groove 51. A support shaft 53 is fixedly connected to the slider 52. A limiting wheel 55 is rotatably connected to the support shaft 53. An annular groove 56 for contacting the outer wall of the cable 100 is provided on the outer circumferential surface of the limiting wheel 55.

[0037] Heat dissipation grooves are provided on both sides of the slide groove 51 .

[0038] A first elastic member 54 is connected between the slider 52 and the inner wall of the slide slot 51. The first elastic member 54 is a spring.

[0039] The cable 100 is passed through the limiting sleeve 4, and the cable 100 is passed between the two limiting wheels 55 along the limiting groove 5, and the limiting wheels 55 move toward the direction close to the slide groove 51. The cable 100 corresponds to the annular groove 56, and the elastic force of the first elastic member 54 causes the outer wall of the cable 100 to contact the inner wall of the annular groove 56, thereby reducing the wear of the cable 100 in the limiting groove 5, improving the protection of the cable 100, and at the same time, making it difficult for the cable 100 to fall out of the limiting groove 5.

[0040] An elastic plate 6 made of rubber is fixedly connected to the end of the limiting groove 5 . The elastic plate 6 is used to contact the cable 100 to enhance the protection of the cable 100 .

[0041] At the joints of the robot, the cables 100 are usually too long, especially when they need to match the folded length of the robot joints. When the joints are extended from the folded state, the cables 100 originally designed for the folded length will appear too long. If the excess cables 100 are not handled properly, a series of problems will arise: 1. The overlong cables 100 will become loose and easily accumulate near the joints, or even get entangled with other cables 100 or the robot structure, causing chaos. 2. The loose cables 100 may swing during the joint movement, collide with or interfere with the robot itself or other objects, and affect the normal movement of the robot.

[0042] Therefore, it is necessary to store the overlong cables. The cable 100 is a highly flexible cable to prevent the cable from being easily broken during bending.

[0043] A storage slot 7 for placing the cable 100 is provided on the inner wall of the limiting sleeve 4. The storage slot 7 is connected to the middle of the limiting slot 5, and the two ends of the storage slot 7 are respectively close to the two limiting wheels 55. A baffle 71 is fixedly connected to the side of the storage slot 7 facing the mounting plate 3 to prevent the cable 100 from escaping from the storage slot 7. A sponge layer (not shown in the figure) is fixedly connected to the inner wall of the storage slot 7 and the inner wall of the baffle 71. A protective arc surface is provided on the inner wall of the storage slot 7 near the end of the limiting wheel 55 to ensure that the bending radius of the cable 100 is greater than the minimum bending radius specified by the manufacturer of the cable 100.

[0044] An installation cavity 8 is provided on the inner wall of the limiting groove 5. The installation cavity 8 is arranged opposite to the storage groove 7. The installation cavity 8 is connected to the storage groove 7 through the limiting groove 5. A slide bar 81 for pushing the cable 100 into the storage groove 7 is slidably connected in the installation cavity 8. A second elastic member 82 is connected between the slide bar 81 and the inner wall of the installation cavity 8. The second elastic member 82 is a spring. In order to make the slide bar 81 move along its own length direction, a T-shaped rod 83 is fixedly connected to the outer wall of the slide bar 81. The length direction of the T-shaped rod 83 is parallel to the length direction of the slide bar 81. A T-shaped groove is provided on the inner wall of the installation cavity 8. The T-shaped rod 83 is slidably connected in the T-shaped groove. The end of the slide bar 81 has an arc-shaped groove 811. The inner wall of the arc-shaped groove 811 is always in contact with the outer wall of the cable 100, so that the cable 100 maintains a certain tension.

[0045] The outer wall of the mounting plate 3 is provided with a linkage assembly 9 for contacting the slide bar 81. The limiting sleeve 4 and the mounting plate 3 rotate relative to each other, and the slide bar 81 moves along its length direction through the linkage assembly 9, and the slide bar 81 pushes the cable 100, so that the redundant cable 100 is located in the storage groove 7.

[0046] The linkage assembly 9 includes a telescopic rod 91, a pressure wheel 92, a straight groove 93, an anti-slip rod 94, a first inclined surface 95 and a second inclined surface 96. The telescopic rod 91 is fixed to the outer wall of the mounting plate 3, and the length direction of the telescopic rod 91 is parallel to the radial direction of the mounting plate 3. The pressure wheel 92 is rotatably connected to the end of the telescopic rod 91 away from the mounting plate 3. The telescopic rod 91 includes a sleeve 911, an inner rod 912 and a third elastic member 913. The third elastic member 913 is a spring. The sleeve 911 is fixed to the outer wall of the mounting plate 3, and the inner rod 912 is slidably connected to the sleeve 911. There is a step on the side wall of the inner rod 912, and a fixing plate is welded to the end of the sleeve 911 to prevent the inner rod 912 from falling out of the sleeve 911. The inner rod 912 is rotatably connected to the pressure wheel 92.

[0047] The straight groove 93 is formed on the inner wall of the limit sleeve 4, and the straight groove 93 is connected to the storage groove 7 through the installation cavity 8 and the limit groove 5. The anti-slip rod 94 is slidably connected in the straight groove 93, the first inclined surface 95 is formed at the end of the slide bar 81, and the second inclined surface 96 is formed at the end of the anti-slip rod 94. The first inclined surface 95 is adapted to the second inclined surface 96 to guide the slide bar 81 to slide when the anti-slip rod 94 moves. The anti-slip rod 94 is L-shaped and is formed by gluing the upper and lower parts together. The anti-slip rod 94 is partially located in the installation cavity 8.

[0048] The pressure wheel 92 is rollingly connected to the inner wall of the limiting sleeve 4 or to the end of the anti-dropping rod 94 away from the second inclined surface 96 .

[0049] One end of the anti-drop rod 94 away from the second inclined surface 96 is hemispherical.

[0050] During the robot joint extension process, the limit sleeve 4 rotates with the output shaft 24, and the limit sleeve 4 and the mounting plate 3 rotate relative to each other, so that the pressure wheel 92 presses on the anti-slip rod 94, and the anti-slip rod 94 moves along the length direction of the straight groove 93. The first inclined surface 95 and the second inclined surface 96 guide the slide bar 81 to move along its own length direction, so that the slide bar 81 crosses the limit groove 5 and pushes the cable 100 to move, so that the excess cable 100 can be moved into the storage groove 7. When the pressure wheel 92 presses on the anti-slip rod 94, it is the limit of joint extension.

[0051] During the folding process of the joint, the pressure wheel 92 is separated from the anti-detachment rod 94, and the sliding rod 81 is quickly reset by the elastic force of the second elastic member 82. The anti-detachment rod 94 is reset by the guiding effect of the first inclined surface 95 and the second inclined surface 96. At this time, the sliding rod 81 cannot apply pressure to the cable 100, so that the excess cable 100 can be removed from the limiting sleeve 4.

[0052] The turning angle of the joint of the robot is less than 180 degrees, that is, the rotation angle of the output shaft 24 is less than 180 degrees.

[0053] An oil storage chamber 200 for storing lubricating oil is provided on the side wall of the limiting wheel 55, and the opening of the oil storage chamber 200 is fixed by a cover plate 201 with threads. An oil outlet hole 202 communicating with the annular groove 56 is provided on the side wall of the oil storage chamber 200. A plunger 203 made of rubber is provided on the oil outlet hole 202, and the plunger 203 blocks the oil outlet hole 202 through a tension spring 206. A support rod 204 with a T-shaped cross section is fixedly connected to the inner wall of the oil outlet hole 202, and the plunger 203 is slidably connected to the support rod 204. An anti-slip sheet 205 is fixedly connected to the support rod 204 to prevent the plunger 203 from detaching from the support rod 204.

[0054] When the limiting wheel 55 rotates, the lubricating oil is discharged from the oil outlet 202 by the centrifugal force and then coated on the outer wall of the cable 100 .

[0055] Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A reducer for a robot joint, comprising an internal gear box (10), an output shaft (24), an input connecting flange (11) and an input shaft, wherein the input shaft is fixed to the inner wall of the input connecting flange (11), and is characterized in that: The input shaft is fixedly connected with a primary sun gear (13), the primary sun gear (13) is meshedly connected with a plurality of first planetary gears (17), the first planetary gears (17) are meshed with the internal gear box (10), the inner wall of the first planetary gear (17) is rotatably connected with a first needle roller shaft (18), the first needle roller shaft (18) is rotatably connected with a primary planetary carrier (15), a first bearing (14) is arranged between the input shaft and the primary planetary carrier (15), and a second bearing (15) is arranged between the primary planetary carrier (15) and the internal gear box (10). 6), the first bearing (14) is located inside the second bearing (16), the end of the first-stage planet carrier (15) is fixedly connected to the second-stage sun gear (22), the tooth portion of the second-stage sun gear (22) is meshingly connected to the second planet gear (23), the inner wall of the second planet gear (23) is fixedly connected to the second needle roller shaft (25), the second needle roller shaft (25) is rotatably connected to the second planet carrier (21), the second planet gear (23) is meshing with the internal gear box (10), and the second-stage planet carrier (21) is connected to the output shaft (24).

2. The reducer applied to a robot joint according to claim 1, characterized in that: A mounting plate (3) is fixedly connected to the outer wall of the inner gear box (10), a cross roller bearing (31) is arranged inside the mounting plate (3), an output flange (33) is connected to the outer wall of the secondary planet carrier (21), the output flange (33) is connected to the cross roller bearing (31), and the secondary sun gear (22) and the second planet gear (23) are both located inside the cross roller bearing (31).

3. The reducer applied to a robot joint according to claim 2, characterized in that: An outer pressure plate (32) is fixedly connected to the end of the mounting plate (3), and the outer pressure plate (32) is used to press against the side wall of the cross roller bearing (31).

4. The reducer applied to a robot joint according to claim 2, characterized in that: A limiting sleeve (4) is arranged on the outer wall of the installation plate (3); a limiting groove (5) for placing the cable (100) is opened on the inner wall of the limiting sleeve (4); the length direction of the limiting groove (5) is parallel to the axial direction of the limiting sleeve (4); and the limiting sleeve (4) is connected to the outer wall of the output shaft (24) via a connecting rod (41).

5. The reducer applied to a robot joint according to claim 4 is characterized in that: A slide groove (51) is provided on the inner wall of the limiting groove (5), and the slide groove (51) is close to the end of the limiting groove (5). A support shaft (53) is slidably connected in the slide groove (51), and a limiting wheel (55) is rotatably connected to the support shaft (53). An annular groove (56) for contacting with the outer wall of the cable (100) is provided on the outer circumferential surface of the limiting wheel (55), and a first elastic member (54) is connected between the support shaft (53) and the inner wall of the slide groove (51).

6. The reducer applied to a robot joint according to claim 5, characterized in that: The inner wall of the limiting sleeve (4) is provided with a storage groove (7) for placing the cable (100), the storage groove (7) is communicated with the middle part of the limiting groove (5), a baffle (71) is fixedly connected to the side of the storage groove (7) facing the mounting plate (3), the inner wall of the limiting groove (5) is provided with an installation cavity (8) opposite to the storage groove (7), a slide rod (81) for pushing the cable (100) into the storage groove (7) is slidably connected to the inner wall of the mounting cavity (8), a second elastic member (82) is connected between the slide rod (81) and the inner wall of the mounting cavity (8), and a linkage component (9) for contacting the slide rod (81) is provided on the outer wall of the mounting plate (3).

7. The reducer applied to a robot joint according to claim 6, characterized in that: The linkage assembly (9) comprises a telescopic rod (91), a pressure wheel (92), a straight groove (93), an anti-slip rod (94), a first inclined surface (95) and a second inclined surface (96). The telescopic rod (91) is fixed on the outer wall of the mounting plate (3). The pressure wheel (92) is rotatably connected to the telescopic rod (91). The straight groove (93) is provided on the inner wall of the limiting sleeve (4) and is connected to the mounting cavity (8). The anti-slip rod (94) is slidably connected to the straight groove (93). The first inclined surface (95) is provided at the end of the sliding rod (81). The second inclined surface (96) is provided at the end of the anti-slip rod (94). The first inclined surface (95) and the second inclined surface (96) are kept in contact with each other. The pressure wheel (92) is rollingly connected to the inner wall of the limiting sleeve (4) or rollingly connected to the end of the anti-slip rod (94) away from the second inclined surface (96).

8. The reducer applied to a robot joint according to claim 7 is characterized in that: The side wall of the limiting wheel (55) is provided with an oil storage cavity (200) for storing lubricating oil. The side wall of the oil storage cavity (200) is provided with an oil outlet hole (202) connected to the annular groove (56). The oil outlet hole (202) is provided with a plunger (203). The plunger (203) blocks the oil outlet hole (202) through a tension spring (206). When the limiting wheel (55) rotates, the lubricating oil is discharged from the oil outlet hole (202) by the action of centrifugal force and then coated on the outer wall of the cable (100).

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