An anthropomorphic robot and a four-degree-of-freedom robotic arm that mimics the shoulder-elbow joint of a human

Abstract

The application discloses an anthropomorphic robot and a four-degree-of-freedom mechanical arm simulating a human shoulder and elbow joint. The four-degree-of-freedom mechanical arm comprises a joint module, a shoulder two-joint module, a shoulder three-joint module, a large arm module and a small arm module, and the modules are sequentially connected. The shoulder one-joint module realizes the pitch freedom of the shoulder, the shoulder two-joint module realizes the roll freedom of the shoulder, the shoulder three-joint module realizes the yaw freedom of the shoulder, and the pitch freedom of the elbow is realized through a fourth joint installed in the large arm module and connected with the small arm module. The first joint in the shoulder one-joint module, the second joint in the shoulder two-joint module, the third joint in the shoulder three-joint module and the fourth joint are respectively controlled by an external driver and an industrial computer, so that the three-degree-of-freedom motion of the shoulder and the one-degree-of-freedom motion of the elbow of the mechanical arm are realized. The application has the characteristics of high bionics, inertia moving up and module integration, can meet the basic motion requirements of the upper limbs of the anthropomorphic robot, and is convenient to control, has less energy consumption and is convenient to disassemble.

Description

Technical Field

[0001] The invention belongs to the field of robots, and in particular relates to a four-degree-of-freedom robotic arm that imitates human shoulder and elbow joints. Background Art

[0002] A compact and reasonable humanoid robot upper limb mechanical structure design is the basis for humanoid robots to perform various operations and complete various tasks. The design of the humanoid robot upper limb mechanical structure has three key points: first, high degree of bionics. The upper limb structure evolved by humans over tens of thousands of years of evolution is sufficient to cope with most task scenarios. Therefore, the humanoid robot upper limb should imitate the degree of freedom configuration of human upper limbs. Second, upward inertia. Whether performing precision operations or withstanding the impact of falls, a robotic arm with upward inertia always brings convenience to control and reduces energy consumption. Third, modular integration. A robotic arm constructed with highly integrated modules has huge advantages in parts procurement and processing, parts upgrades and iterations, and assembly and disassembly of the entire machine. The shortcomings of existing humanoid robot upper limb mechanical structure designs are mainly low inertia and low integration, which lead to relatively high energy consumption and inconvenient assembly and disassembly. Summary of the Invention

[0003] In view of the shortcomings in the prior art, the present invention provides a four-degree-of-freedom robotic arm that imitates the human shoulder and elbow joints.

[0004] The present invention achieves the above technical objectives through the following technical means.

[0005] A four-degree-of-freedom robotic arm that mimics the human shoulder and elbow joints, comprising a shoulder-1 joint module, a shoulder-2 joint module, a shoulder-3 joint module, an upper arm module, and a lower arm module. The shoulder-1 joint module is connected to the shoulder-2 joint module, the shoulder-2 joint module is connected to the shoulder-3 joint module, the shoulder-3 joint module is connected to the upper arm module, and the upper arm module is connected to the lower arm module. The shoulder-1 joint module realizes the shoulder pitch degree of freedom, the shoulder-2 joint module realizes the shoulder roll degree of freedom, and the shoulder-3 joint module realizes the shoulder yaw degree of freedom. The elbow pitch degree of freedom is realized by an integrated linear joint installed in the upper arm module and connected to the lower arm module.

[0006] The boom module includes a fourth joint, a boom sleeve, a deep groove ball bearing support shaft, a fourth joint main shaft and a fourth joint secondary shaft, and the fourth joint is located inside the boom sleeve; the output end sleeve of the fourth joint is fixedly connected to the fourth joint secondary shaft by a flat head bolt and a bolt washer, the fixed end sleeve of the fourth joint is fixedly connected to one end of the deep groove ball bearing support shaft, and the other end of the deep groove ball bearing support shaft is buckled with the deep groove ball bearing inner retaining ring, a fixed deep groove ball bearing is sleeved on one end of the deep groove ball bearing support shaft close to the deep groove ball bearing inner retaining ring, a deep groove ball bearing outer support is sleeved on the outer side of the deep groove ball bearing, and the deep groove ball bearing outer support is buckled with the upper through hole of the boom sleeve; the thrust bearing outer support buckled with the lower through hole of the boom sleeve, on the one hand, fixes the outer ring of the thrust bearing, and on the other hand, cooperates with the inner ring of the thrust bearing to fix the fourth joint main shaft;

[0007] The forearm module includes a forearm sleeve and a carbon fiber tube; the main shaft sleeve of the forearm sleeve fixes the needle roller bearing and the loose ring outer ring of the thrust bearing on the fourth joint main shaft in sequence, and then is inserted into the fourth joint main shaft; the secondary shaft sleeve of the forearm sleeve fixes the needle roller bearing on the fourth joint secondary shaft, and then is inserted into the fourth joint secondary shaft; the carbon fiber tube is fixed in the tube sleeve of the forearm sleeve.

[0008] In the above technical solution, the shoulder-joint module includes a first joint, a first cross-roller bearing and a first U-shaped frame; the output inner ring of the first joint is fixedly connected to the radial side of the first U-shaped frame through a first output flange, and the fixed outer ring of the first joint is fixedly connected to the arm ring through a first fixed adapter flange; the first cross-roller bearing is located between the first joint and the first U-shaped frame, and the outer ring of the first cross-roller bearing is fixed through the first fixed adapter flange and the groove of the outer retaining ring of the first cross-roller bearing, and the inner ring of the first cross-roller bearing is fixed through the first output flange and the shoulder on the radial side of the first U-shaped frame.

[0009] In the above technical solution, the outer retaining ring of the first cross roller bearing is made of steel.

[0010] In the above technical solution, the shoulder joint module includes a second joint, a second U-shaped frame and a second cross roller bearing; the output inner ring of the second joint is fixedly connected to the axial side of the second U-shaped frame through the second output flange, the fixed outer ring of the second joint is fixedly connected to the axial side of the first U-shaped frame, and the second U-shaped frame is located inside the first U-shaped frame; the outer ring of the second cross roller bearing is fixed by the groove of the outer retaining ring of the second cross roller bearing on the other axial side of the second U-shaped frame, the inner ring of the second cross roller bearing is fixed by the second fixed adapter flange and the shoulder of the inner support of the second cross roller bearing, and the second fixed adapter flange is installed on the other axial side of the first U-shaped frame.

[0011] In the above technical solution, the shoulder three-joint module includes a third joint and a third cross-roller bearing; the output inner ring of the third joint is fixedly connected to the third output adapter flange through the third output flange, and the fixed outer ring of the third joint is fixedly connected to the radial side of the second U-shaped frame through the third fixed adapter flange; the outer ring of the third cross-roller bearing is fixed through the radial side of the second U-shaped frame and the groove of the outer retaining ring of the third cross-roller bearing, and the inner ring of the third cross-roller bearing is fixed through the third output flange and the shoulder of the third output adapter flange, and the outer retaining ring of the third cross-roller bearing is fixed to the radial side of the second U-shaped frame; the bottom of the third output adapter flange is connected to the top of the arm sleeve by screws.

[0012] In the above technical solution, the outer retaining ring of the third cross roller bearing, the deep groove ball bearing support shaft, the fourth joint main shaft and the fourth joint secondary shaft are all made of steel.

[0013] In the above technical solution, the screws on the third output adapter flange are aligned with the recessed portion at the bottom of the second U-shaped frame.

[0014] In the above technical solution, when the fixed end sleeve of the fourth joint is fixedly connected to one end of the deep groove ball bearing support shaft, a compensation gasket is used.

[0015] In the above technical solution, a protrusion is provided on the deep groove ball bearing support shaft, and the protrusion and the inner retaining ring of the deep groove ball bearing respectively fix the two sides of the inner ring of the deep groove ball bearing.

[0016] A humanoid robot comprises the above-mentioned four-degree-of-freedom robotic arm that imitates the human shoulder and elbow joints.

[0017] The beneficial effects of the present invention are:

[0018] (1) The design of the shoulder-joint module in the present invention allows the entire robotic arm, except for the first joint and the first fixed adapter flange, to be pre-assembled and then installed as a whole on the arm ring; this eliminates the need for most assembly processes on the entire robot, bringing great convenience.

[0019] (2) The double U-shaped frame design of the shoulder joint module 1 and the shoulder joint module 2 in the present invention allows the position of the third joint to be as high as possible, reaching a height that is almost flush with the first joint and the second joint, which cannot be achieved by the existing structure. In this way, the inertia is shifted upward, which makes control more convenient and reduces energy consumption.

[0020] (3) The connection design between the shoulder three-joint module and the upper arm module in the present invention allows the upper arm module and the shoulder three-joint module to be freely installed and disassembled, which brings great convenience.

[0021] (4) The fourth joint of the upper arm module in the present invention is an integrated linear joint. Such a design can not only realize the upward shift of inertia, but also adjust the side length of the push rod triangle (composed of the upper arm sleeve, the lower arm sleeve and the fourth joint) by changing the size of the upper arm sleeve and the lower arm sleeve, thereby changing the achievable working range and the maximum torque that can be borne by the elbow pitch freedom.

[0022] (5) The four degrees of freedom of the entire robotic arm of the present invention are all achieved through integrated joints. The number of designed connectors is streamlined, and they have good portability and high integration characteristics, which facilitates the procurement and processing of parts, the upgrading and iteration of parts, and the assembly and disassembly of the entire machine. To replace different types of integrated joints, only the size of the corresponding connectors needs to be adjusted. In addition, the end of the forearm of the present invention can be fixedly connected to various integrated robotic arms through a simple pipe-sleeve connector to perform different operational tasks. The modularization greatly facilitates subsequent structural iteration and expansion design. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a cross-sectional view of the shoulder joint 1, shoulder joint 3 and upper arm module of the present invention;

[0024] Figure 2 This is a cross-sectional view of the shoulder joint 1 and shoulder joint 2 modules of the present invention;

[0025] Figure 3 This is a cross-sectional view of the fourth joint secondary axis of the present invention;

[0026] Figure 4 Exploded view of the assembly of the shoulder joint 1, shoulder joint 2 and shoulder joint 3 modules of the present invention;

[0027] Figure 5 This is an exploded view of the assembly of the boom and arm modules of the present invention;

[0028] Figure 6 This is the overall structure diagram of the four-degree-of-freedom robotic arm that mimics the human shoulder and elbow joints of the present invention;

[0029] In the figure: 0-arm ring, 11-first joint, 12-first output flange, 13-first fixed adapter flange, 14-first cross roller bearing, 15-first cross roller bearing outer retaining ring, 16-first U-shaped frame, 21-second joint, 22-second output flange, 23-second U-shaped frame, 24-second cross roller bearing outer retaining ring, 25-second cross roller bearing, 26-second fixed adapter flange, 27-second cross roller bearing inner support, 31-third joint, 32-third fixed adapter flange, 33-third output flange, 34-third cross roller bearing, 35 -Outer retaining ring of the third cross roller bearing, 36-Third output adapter flange, 41-Fourth joint, 42-Arm sleeve, 43-Deep groove ball bearing outer support, 44-Deep groove ball bearing, 45-Deep groove ball bearing inner retaining ring, 46-Deep groove ball bearing support shaft, 47-Compensating gasket, 48-Thrust bearing outer support, 49-Fourth joint main shaft, 410-Thrust bearing, 411-Fourth joint secondary shaft, 412-Flat head bolt, 413-Bolt washer, 51-Forearm sleeve, 52-Needle roller bearing on the fourth joint main shaft, 53-Needle roller bearing on the fourth joint secondary shaft, 54-Carbon fiber tube. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0031] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 As shown, a four-degree-of-freedom robotic arm that mimics the human shoulder and elbow joints includes a shoulder 1 joint module, a shoulder 2 joint module, a shoulder 3 joint module, a boom module, and a forearm module. The shoulder pitch degree of freedom is achieved through the shoulder 1 joint module, the shoulder roll degree of freedom is achieved through the shoulder 2 joint module, the shoulder yaw degree of freedom is achieved through the shoulder 3 joint module, and the elbow pitch degree of freedom is achieved through an integrated linear joint (i.e., the fourth joint 41) installed in the boom module and connected to the forearm module.

[0032] The shoulder-joint module includes a first joint 11, a first output flange 12, a first fixed adapter flange 13, a first cross-roller bearing 14, a first cross-roller bearing outer retaining ring 15, and a first U-shaped frame 16. First joint 11 is an integrated rotary joint, integrating a motor, reducer, encoder, and other components. Its output inner ring is fixedly connected to the radial side of the first U-shaped frame 16 via the first output flange 12, and a cylindrical pin is driven in to eliminate output backlash. Its fixed outer ring is fixedly connected to the arm ring 0 via the first fixed adapter flange 13, and the arm ring 0 is fixed to the robot's thorax. The first cross-roller bearing 14 is located between the first joint 11 and the first U-shaped frame 16. Its outer ring is secured by grooves in the first fixed adapter flange 13 and the first cross-roller bearing outer retaining ring 15, while its inner ring is secured by the first output flange 12 and the radial shoulder of the first U-shaped frame 16, ensuring the four corners of the cross-roller bearing are fixed. The first fixed adapter flange 13 and the first cross roller bearing outer ring 15 are further fixedly connected by screws, and the first output flange 12 is fixed to the first U-shaped frame 16. The first cross roller bearing outer ring 15 is made of steel to ensure strength.

[0033] The specific installation process of the shoulder joint module is as follows: first, put the first cross roller bearing outer retaining ring 15 on the corresponding part of the first U-shaped frame 16, then press in the first cross roller bearing 14, and install the first output flange 12; after the entire robotic arm except the first joint 11 and the first fixed adapter flange 13 is installed, first install the first fixed adapter flange 13 and the first joint 11 on the arm ring 0, and then lock it with screws through the first cross roller bearing outer retaining ring 15.

[0034] The shoulder joint module includes a second joint 21, a second output flange 22, a second U-shaped frame 23, a second cross-roller bearing outer retaining ring 24, a second cross-roller bearing 25, a second fixed adapter flange 26, and a second cross-roller bearing inner support 27. The second joint 21 is an integrated rotary joint, integrating a motor, reducer, encoder, and other components. Its output inner ring is axially connected to one side of the second U-shaped frame 23 via the second output flange 22, with a cylindrical pin driven into it to eliminate output backlash. Its fixed outer ring is axially connected to one side of the first U-shaped frame 16; the second U-shaped frame 23 is located inside the first U-shaped frame 16. For the second cross roller bearing 25, its outer ring is fixed by the groove of the second cross roller bearing outer retaining ring 24 on the other axial side of the second U-shaped frame 23, and its inner ring is fixed by the second fixed adapter flange 26 and the shoulder of the second cross roller bearing inner support 27 to ensure that the four corners of the cross roller bearing are fixed; the other axial side of the second U-shaped frame 23 is fixedly connected to the second cross roller bearing outer retaining ring 24, the second fixed adapter flange 26 is fixedly connected to the second cross roller bearing inner support 27, and the second fixed adapter flange 26 is installed on the other axial side of the first U-shaped frame 16.

[0035] The specific installation process of the shoulder joint module is as follows: first press the second cross roller bearing 25 onto the second U-shaped frame 23, install the second cross roller bearing outer retaining ring 24, fit the first U-shaped frame 16 and the second U-shaped frame 23, install the second joint 21 and the second output flange 22, then install the second fixed adapter flange 26, and finally lock the second cross roller bearing inner support 27 with screws.

[0036] The shoulder triple joint module includes a third joint 31, a third fixed adapter flange 32, a third output flange 33, a third crossed roller bearing 34, a third crossed roller bearing outer ring 35, and a third output adapter flange 36. The third joint 31 is an integrated rotary joint, integrating a motor, reducer, encoder, and other components. Its output inner ring is fixedly connected to the third output adapter flange 36 via the third output flange 33, with cylindrical pins driven in to eliminate output backlash. Its fixed outer ring is fixedly connected to the radial side of the second U-shaped frame 23 via the third fixed adapter flange 32. The outer ring of the third crossed roller bearing 34 is secured by grooves on the radial side of the second U-shaped frame 23 and in the third crossed roller bearing outer ring 35. Its inner ring is secured by the third output flange 33 and the shoulder of the third output adapter flange 36, ensuring the cross roller bearing is secure at all four corners. The third crossed roller bearing outer ring 35 is fixedly connected to the radial side of the second U-shaped frame 23. The third crossed roller bearing outer ring 35 is made of steel to ensure strength.

[0037] The specific installation process of the shoulder three-joint module is: first, fix the third joint 31 with the third fixed adapter flange 32, then install the whole on the second U-shaped frame 23, use screws to lock the third output flange 33 and the third cross roller bearing 34 through the third cross roller bearing outer retaining ring 35, and finally install the third output adapter flange 36.

[0038] The upper arm module includes a fourth joint 41, an upper arm sleeve 42, a deep groove ball bearing outer support 43, a deep groove ball bearing 44, a deep groove ball bearing inner retaining ring 45, a deep groove ball bearing support shaft 46, a compensation gasket 47, a thrust bearing outer support 48, a fourth joint main shaft 49, a thrust bearing 410, a fourth joint secondary shaft 411, a flat head bolt 412, and a bolt gasket 413. Among them, the number of the deep groove ball bearing outer support 43, the deep groove ball bearing 44, the deep groove ball bearing inner retaining ring 45, the deep groove ball bearing support shaft 46, the compensation gasket 47, the thrust bearing outer support 48, the thrust bearing 410, the flat head bolt 412, and the bolt gasket 413 is 2. The fourth joint 41 is an integrated linear joint, which integrates a motor, encoder, lead screw and its nut, etc. Its output end sleeve is fixedly connected to the fourth joint secondary shaft 411 by a flat head bolt 412 and a bolt washer 413. Its fixed end sleeve is fixedly connected to one end of the deep groove ball bearing support shaft 46. The other end of the deep groove ball bearing support shaft 46 is buckled with the deep groove ball bearing inner retaining ring 45. When the fixed end sleeve of the fourth joint 41 is fixedly connected to one end of the deep groove ball bearing support shaft 46, the compensation washer 47 is used. , ensuring that the relative position of the fourth joint 41 and the boom sleeve 42 meets the required motion precision. A deep groove ball bearing 44 is mounted on the end of the deep groove ball bearing support shaft 46 near the deep groove ball bearing inner retaining ring 45. A protrusion is provided on the deep groove ball bearing support shaft 46, which, together with the deep groove ball bearing inner retaining ring 45, secures the inner ring of the deep groove ball bearing 44 on either side. A deep groove ball bearing outer support 43 is mounted on the outer side of the deep groove ball bearing 44, which engages with the upper through-hole of the boom sleeve 42. The fourth joint 41 is located within the boom sleeve 42, with the top of the boom sleeve 42 connected to the bottom of the third output adapter flange 36 via screws. A thrust bearing outer support 48, which engages with the lower through-hole of the boom sleeve 42, secures the outer ring of the thrust bearing 410 and, in conjunction with the inner ring of the thrust bearing 410, secures the fourth joint main shaft 49. The deep groove ball bearing support shaft 46, the fourth joint main shaft 49, and the fourth joint secondary shaft 411 are made of steel to ensure strength. The radial length of the second U-shaped frame 23 is close to the length of the shorter side of the boom sleeve 42, making it difficult to disassemble the boom sleeve 42 from the third output adapter flange 36. Therefore, aligning the screws on the third output adapter flange 36 with the flower-shaped recessed portion at the bottom of the second U-shaped frame 23 allows for easy installation and removal of the shoulder three-joint module and the boom module.

[0039] The forearm module includes a forearm sleeve 51, a needle roller bearing 52 on the fourth joint main shaft, a needle roller bearing 53 on the fourth joint secondary shaft, and a carbon fiber tube 54. The number of the needle roller bearings 52 on the fourth joint main shaft and the needle roller bearings 53 on the fourth joint secondary shaft are both 2. The main shaft sleeve of the forearm sleeve 51 fixes the needle roller bearing 52 on the fourth joint main shaft and the loose ring outer ring of the thrust bearing 410 in sequence, and then is inserted into the fourth joint main shaft 49. The secondary shaft sleeve of the forearm sleeve 51 fixes the needle roller bearing 53 on the fourth joint secondary shaft, and then is inserted into the fourth joint secondary shaft 411. The carbon fiber tube 54 is inserted into the tube sleeve of the forearm sleeve 51 and locked with 4 screws.

[0040] The specific installation process of the upper arm module and the lower arm module is as follows: first, place the fourth joint 41 into the upper arm sleeve 42, press in the deep groove ball bearing support shaft 46 and compensation washer 47, then use screws to lock the deep groove ball bearing 44 through the deep groove ball bearing outer support 43, and then buckle the deep groove ball bearing inner retaining ring 45. After pressing the needle roller bearing 52 on the fourth joint main shaft and the needle roller bearing 53 on the fourth joint secondary shaft into the lower arm sleeve 51, insert the fourth joint main shaft 49, and use screws through the thrust bearing outer support 48 to simultaneously lock the fourth joint main shaft 49 and thrust bearing 410. Finally, insert the fourth joint secondary shaft 411, tighten it with flat head bolts 412 through bolt washers 413, and then insert the carbon fiber tube 54 and tighten it with screws.

[0041] The working principle of the four-degree-of-freedom robotic arm that imitates the human shoulder and elbow joints of the present invention is: through an external driver and an industrial computer, the first joint 11, the second joint 21, the third joint 31 and the fourth joint 41 are controlled respectively to realize the three-degree-of-freedom movement of the shoulder of the robotic arm (including pitch, roll and yaw degrees of freedom) and the one-degree-of-freedom movement of the elbow (i.e., the pitch degree of freedom of the elbow).

[0042] The embodiments described are preferred implementations of the present invention, but the present invention is not limited to the above implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the scope of protection of the present invention.

Claims

1. A four-degree-of-freedom robotic arm that mimics the human shoulder and elbow joints, characterized in that: It includes a shoulder joint module, a shoulder joint module, a shoulder joint module, an upper arm module and a lower arm module. The shoulder joint module is connected to the shoulder joint module, the shoulder joint module is connected to the shoulder joint module, the shoulder joint module is connected to the upper arm module, and the upper arm module is connected to the lower arm module. The shoulder joint module realizes the pitch freedom of the shoulder, the shoulder joint module realizes the roll freedom of the shoulder, and the shoulder joint module realizes the yaw freedom of the shoulder. The elbow pitch freedom is realized by an integrated linear joint installed in the upper arm module and connected to the lower arm module. The arm module comprises a fourth joint (41), an arm sleeve (42), a deep groove ball bearing support shaft (46), a fourth joint main shaft (49) and a fourth joint secondary shaft (411), wherein the fourth joint (41) is located inside the arm sleeve (42); the output end sleeve of the fourth joint (41) is fixedly connected to the fourth joint secondary shaft (411) by a flat head bolt (412) and a bolt washer (413); the fixed end sleeve of the fourth joint (41) is fixedly connected to one end of the deep groove ball bearing support shaft (46); the other end of the deep groove ball bearing support shaft (46) is fixedly connected to the deep groove ball bearing inner retaining ring ( 45) is buckled, a fixed deep groove ball bearing (44) is sleeved on one end of the deep groove ball bearing support shaft (46) close to the deep groove ball bearing inner retaining ring (45), a deep groove ball bearing outer support (43) is sleeved on the outer side of the deep groove ball bearing (44), and the deep groove ball bearing outer support (43) is buckled with the upper through hole of the upper arm sleeve (42); the thrust bearing outer support (48) is buckled with the lower through hole of the upper arm sleeve (42), on the one hand, fixes the outer ring of the thrust bearing (410), and on the other hand, cooperates with the inner ring of the thrust bearing (410) to fix the fourth joint main shaft (49); The forearm module comprises a forearm sleeve (51) and a carbon fiber tube (54); the main shaft sleeve of the forearm sleeve (51) sequentially fixes the needle roller bearing (52) on the fourth joint main shaft and the loose ring outer ring of the thrust bearing (410), and then is inserted into the fourth joint main shaft (49); the secondary shaft sleeve of the forearm sleeve (51) fixes the needle roller bearing (53) on the fourth joint secondary shaft, and then is inserted into the fourth joint secondary shaft (411); the carbon fiber tube (54) is fixed in the sleeve sleeve of the forearm sleeve (51); The shoulder-joint module comprises a first joint (11), a first cross roller bearing (14) and a first U-shaped frame (16); the output inner ring of the first joint (11) is fixedly connected to a radial side of the first U-shaped frame (16) through a first output flange (12), and the fixed outer ring of the first joint (11) is fixedly connected to the arm ring (0) through a first fixed adapter flange (13); the first cross roller bearing (14) is located between the first joint (11) and the first U-shaped frame (16), and the outer ring of the first cross roller bearing (14) is fixed through the first fixed adapter flange (13) and the groove of the first cross roller bearing outer retaining ring (15), and the inner ring of the first cross roller bearing (14) is fixed through the first output flange (12) and the shoulder on a radial side of the first U-shaped frame (16).

2. The four-degree-of-freedom robotic arm that simulates the human shoulder and elbow joint according to claim 1, characterized in that: The first cross roller bearing outer retaining ring (15) is made of steel.

3. The four-degree-of-freedom robotic arm that simulates human shoulder and elbow joints according to claim 1, characterized in that: The shoulder joint module includes a second joint (21), a second U-shaped frame (23) and a second cross roller bearing (25); the output inner ring of the second joint (21) is fixedly connected to the axial side of the second U-shaped frame (23) through the second output flange (22), the fixed outer ring of the second joint (21) is fixedly connected to the axial side of the first U-shaped frame (16), and the second U-shaped frame (23) is located inside the first U-shaped frame (16); the outer ring of the second cross roller bearing (25) is fixed by the groove of the second cross roller bearing outer retaining ring (24) on the axial other side of the second U-shaped frame (23), the inner ring of the second cross roller bearing (25) is fixed by the second fixed adapter flange (26) and the shaft shoulder of the second cross roller bearing inner support (27), and the second fixed adapter flange (26) is installed on the axial other side of the first U-shaped frame (16).

4. The four-degree-of-freedom robotic arm that simulates human shoulder and elbow joints according to claim 3, characterized in that: The shoulder three-joint module includes a third joint (31) and a third cross roller bearing (34); the output inner ring of the third joint (31) is fixedly connected to the third output adapter flange (36) through the third output flange (33), and the fixed outer ring of the third joint (31) is fixedly connected to the radial side of the second U-shaped frame (23) through the third fixed adapter flange (32); the outer ring of the third cross roller bearing (34) is fixed through the radial side of the second U-shaped frame (23) and the groove of the third cross roller bearing outer retaining ring (35), the inner ring of the third cross roller bearing (34) is fixed through the third output flange (33) and the shaft shoulder of the third output adapter flange (36), and the third cross roller bearing outer retaining ring (35) is fixedly connected to the radial side of the second U-shaped frame (23); the bottom of the third output adapter flange (36) is connected to the top of the arm sleeve (42) through screws.

5. The four-degree-of-freedom robotic arm that simulates human shoulder and elbow joints according to claim 4, characterized in that: The third cross roller bearing outer retaining ring (35), the deep groove ball bearing support shaft (46), the fourth joint main shaft (49) and the fourth joint secondary shaft (411) are all made of steel.

6. The four-degree-of-freedom robotic arm that simulates human shoulder and elbow joints according to claim 4, characterized in that: The screws on the third output adapter flange (36) are aligned with the recessed portion at the bottom of the second U-shaped frame (23).

7. The four-degree-of-freedom robotic arm that simulates human shoulder and elbow joints according to claim 1, characterized in that: When the fixed end sleeve of the fourth joint (41) is fixedly connected to one end of the deep groove ball bearing support shaft (46), a compensation washer (47) is used.

8. The four-degree-of-freedom robotic arm that simulates human shoulder and elbow joints according to claim 1, characterized in that: The deep groove ball bearing support shaft (46) is provided with a protrusion, and the protrusion and the deep groove ball bearing inner retaining ring (45) respectively fix two sides of the inner ring of the deep groove ball bearing (44).

9. A humanoid robot, characterized in that: A four-degree-of-freedom robotic arm that imitates the human shoulder and elbow joint as described in any one of claims 1 to 8.

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