Transmission structure of mechanical arm

Abstract

According to the transmission structure of the mechanical arm, output shafts of a fourth shaft motor, a fifth shaft motor and a sixth shaft motor of the mechanical arm are located on the same straight line; the transmission structure comprises a transmission structure between the fourth shaft motor and the fourth shaft speed reducer, a transmission structure between the fifth shaft motor and the fifth shaft speed reducer, and a transmission structure between the sixth shaft motor and the sixth shaft speed reducer; according to the transmission structure, the output of each motor is transmitted to the speed reducer of each moving shaft of the mechanical arm, the overall structure is compact, and compared with an existing structure, the equipment weight is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of manipulators, and in particular relates to a transmission structure of a manipulator arm. The transmission structure is all or a part of the transmission structure of the manipulator arm. Background Art

[0002] The robotic arm is an important automation device that appeared in the late 1950s and has developed rapidly in recent years. It has now become an important means of realizing industrial automation. Although the robotic arm is not as flexible as human hands at present, it has the characteristics of being able to repeat work and labor continuously, being tireless, not afraid of danger, and having greater strength to lift heavy objects than human hands. Therefore, the robotic arm has been paid attention to by many departments and enterprises and has been used more and more widely.

[0003] For a six-axis robotic arm, existing technology sets three motors at the input end of the fourth axis. The transmission structure inside the robotic arm transmits the outputs of the three motors to the fourth-axis reducer, the fifth-axis reducer and the sixth-axis reducer. The overall structure of the equipment is too large, resulting in an increase in the weight of the equipment. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present application provides a transmission structure of a robotic arm.

[0005] In the transmission structure of the robotic arm provided in the present invention, the output shafts of the fourth axis motor, the fifth axis motor and the sixth axis motor (123) of the robotic arm are located on the same straight line. The output of each motor is transmitted to the reducer of each moving axis of the robotic arm through the transmission structure provided by the present application. The overall structure is compact and the weight of the equipment is reduced compared to the existing structure.

[0006] Furthermore, the transmission structure of the robot arm provided in the present application adopts gears instead of belts, so as to reduce the need to disassemble the equipment for maintenance and replacement of belts due to severe belt wear during use;

[0007] In the transmission process, in order to solve the problem that the motor needs to output high torque under the use requirement of large load and the external meshing method using a gear set with a large reduction ratio will make the overall equipment too large, the transmission structure provided by the present application uses an internal meshing method for transmission, which effectively reduces the space volume;

[0008] In addition, the bevel gear in the present application adopts an integrated bevel gear shaft, which can reduce the force and damage to the fastening screws caused by vibration and improper displacement during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of the external structure of the transmission structure of the mechanical arm provided in Example 1;

[0010] Figure 2 A schematic diagram of the internal structure of the transmission structure of the mechanical arm provided in Example 1;

[0011] Figure 3 This is an enlarged schematic diagram of a part of the transmission structure of the mechanical arm provided in Example 1;

[0012] Figure 4 An enlarged schematic diagram of another part of the transmission structure of the robot arm provided in Example 1;

[0013] Figure 5 This is a schematic diagram of an enlarged structure of the fifth-axis and sixth-axis reducer parts included in the transmission structure of the robotic arm provided in Example 1. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] Example 1

[0016] This embodiment provides a transmission structure of a robot arm for use on the fourth axis, fifth axis and sixth axis of a six-axis robot arm, through which the motion and torque output by the motor 12 are transmitted to the joints of the fourth axis, fifth axis and sixth axis of the robot arm. Figure 1 and Figure 2 The fourth axis connecting rod 1 of the robot arm is used to install the fourth axis reducer 13, the third axis reducer 11 and the third axis motor 10. The fourth axis motor 121, the fifth axis motor 122 and the sixth axis motor 123 are also installed on the fourth axis connecting rod 1 through the three-axis fixing plate 9 and are located at the leftmost end (relative to Figure 1 direction in the middle).

[0017] One end of the connecting rod 3 of the robot arm is connected to the fourth axis connecting rod 1 through the adapter flange 2, and the other end is connected to the fourth axis connecting rod 4 and assembled with the fifth and sixth axis components.

[0018] The external structure of the five-sixth axis assembly includes a four-axis connecting rod 4, a six-axis structural component 5, a six-axis structural component end cover 6, a sixth-axis reducer and end 7, and a fifth-axis reducer 8.

[0019] In this embodiment, refer to Figure 1 and Figure 2 , the output shafts of the fourth axis motor 121, the fifth axis motor 122 and the sixth axis motor 123 of the robot arm are located on the same straight line;

[0020] Combination Figure 3 The transmission structure between the fourth-axis motor 121 and the fourth-axis reducer 13 includes:

[0021] The fourth-axis cylindrical spur gear 16 is connected to the output shaft of the fourth-axis motor 121;

[0022] The fourth shaft cylindrical internal gear 17, the inner ring of which is meshed with the fourth shaft cylindrical spur gear 16, and the fourth shaft reducer 13 is coaxially connected with the fourth shaft cylindrical internal gear 17;

[0023] In this embodiment, the fourth shaft reducer 13 and the fourth shaft cylindrical internal gear 17 are transmitted via the fourth shaft transmission spur gear shaft 18 .

[0024] The transmission structure between the fourth-axis motor 121 and the fourth-axis reducer 13 uses internal meshing for transmission, which solves the problem that when the motor needs to output high torque and use a gear set with a large reduction ratio under heavy load requirements, the external meshing method will make the overall device too large.

[0025] Reference Figure 2 In the present embodiment, the fourth shaft transmission spur gear shaft 18 transmits power to the front end and then transmits torque to the fourth shaft reducer 13 through the fourth shaft reducer input driven gear 19 meshing therewith.

[0026] Combination Figure 4 The transmission structure between the fifth-axis motor 122 and the fifth-axis reducer 8 includes:

[0027] The fifth-axis cylindrical spur gear 14 is connected to the output shaft of the fifth-axis motor 122;

[0028] The fifth shaft transmission shaft 20 comprises a first end and a second end. The first end of the fifth shaft transmission shaft 20 is driven to rotate by the fifth shaft cylindrical spur gear 14 through a set of intermediate gear sets; the second end of the fifth shaft transmission shaft 20 is connected to the first end of the fifth shaft transmission tube 23 through a spline;

[0029] A fifth shaft transmission tube 23, comprising a first end and a second end, wherein the second end of the fifth shaft transmission tube 23 is connected to the fifth shaft bevel gear 24;

[0030] The fifth-shaft bevel gear shaft 27 is meshed with the fifth-shaft bevel gear 24 , and the fifth-shaft reducer 8 is coaxially connected with the fifth-shaft bevel gear shaft 27 ; the fifth-shaft bevel gear shaft 27 and the central axis of the fifth-shaft bevel gear 24 are perpendicular to each other.

[0031] Combination Figure 5 The transmission structure between the sixth-axis motor 123 and the sixth-axis reducer 7 includes:

[0032] The sixth shaft transmission shaft 21 comprises a first end 15 and a second end, wherein the first end 15 of the sixth shaft transmission shaft 21 is connected to the output shaft of the sixth shaft motor 123, and the second end of the sixth shaft transmission shaft 21 is connected to the first sixth shaft arc bevel gear shaft 22 via a spline;

[0033] The second six-axis arc bevel gear shaft 25 is meshed with the first six-axis arc bevel gear shaft 22 ; and the central axes of the second six-axis arc bevel gear shaft 25 and the first six-axis arc bevel gear shaft 22 are perpendicular to each other.

[0034] The third six-axis arc bevel gear shaft 28 is meshed with the second six-axis arc bevel gear shaft 25, and the central axes of the third six-axis arc bevel gear shaft 28 and the second six-axis arc bevel gear shaft 25 are perpendicular to each other, and the sixth-axis reducer 7 is coaxially connected to the third six-axis arc bevel gear shaft 28.

[0035] In this embodiment, the fifth-axis transmission shaft 20 is a hollow shaft, the sixth-axis transmission shaft 21 is arranged in the inner cavity of the fifth-axis transmission shaft 20, and the axes of the sixth-axis transmission shaft 21 and the fifth-axis transmission shaft 20 are parallel to each other. The above technical solution reduces the weight of the transmission shaft, facilitates installation and processing, and can reduce the dead weight of the equipment and the load and motion inertia of the motion joints during use.

[0036] The transmission shaft of the transmission device uses a hollow shaft. The maximum torque that a hollow shaft and a solid shaft of the same diameter can withstand is the same, but the hollow shaft can obviously save materials. In actual use, the shaft often needs to be heat treated, and the surface of the material is often strengthened more than the core. Only the outer surface of the solid shaft is strengthened, while the hollow shaft is strengthened on both the inside and outside, so the hollow shaft of the same diameter has higher strength.

[0037] In this embodiment, a spline connection is used to replace the existing coupling connection in the split part of the transmission shaft, which has the following advantages: 1) The spline has a more uniform connection force; 2) The stress concentration at the root of the tooth is smaller, and the strength of the shaft and the hub is less weakened; 3) The number of teeth is large, the total contact area is large, and a larger load can be sustained; 4) The parts on the shaft have good concentricity with the shaft; the guiding property is better; 5) The processing accuracy and connection quality can be improved by cutting.

[0038] Combination Figure 5 In this embodiment, two second six-axis arc bevel gear shafts 25 are arranged, and the two second six-axis arc bevel gear shafts 25 are driven by spur gears 26. One of the second six-axis arc bevel gear shafts 25 is meshed with the first six-axis arc bevel gear shaft 22, and the other second six-axis arc bevel gear shaft 25 is meshed with the third six-axis arc bevel gear shaft 28. The power is transmitted to the sixth-axis reducer 7 through the above structure.

[0039] In a preferred embodiment, the tail end of the fifth-shaft bevel gear shaft 27 is provided with an external thread, and a nut is configured to be connected to the external thread at the tail end of the fifth-shaft bevel gear shaft 27; and / or

[0040] The tail end of the second six-axis arc bevel gear shaft 25 is provided with an external thread, and a nut is configured to be connected to the external thread at the tail end of the fifth-axis bevel gear shaft 27 .

[0041] In this embodiment, the tail end of the fifth-shaft bevel gear shaft 27 is provided with an external thread, and a nut is configured to be connected to the external thread at the tail end of the fifth-shaft bevel gear shaft 27; and

[0042] The tail end of the second six-axis arc bevel gear shaft 25 is provided with an external thread, and a nut is configured to be connected to the external thread at the tail end of the fifth-axis bevel gear shaft 27 .

[0043] The first six-axis arc bevel gear shaft 22 and the five-axis transmission tube 23 are installed on the four-axis connecting rod 4. The two second six-axis arc bevel gears 25 are respectively installed on the first six-axis bearing seat 31 and the second six-axis bearing seat 32 through tapered roller bearings. The end of the second six-axis arc bevel gear 25 is a threaded structure. Because the tapered roller bearing has a certain amount of clearance in the axial direction, the axial position of the second six-axis arc bevel gear 25 can be adjusted by screwing the round nut 29, thereby ensuring the meshing distance with the six-axis arc bevel gear shaft 22 and the third six-axis arc bevel gear 28. After the adjustment is completed, the round nut 29 is fixed with a locking washer 30 to prevent the round nut 29 from loosening due to vibration and other reasons during use.

[0044] At the transmission position of the fifth and sixth axes, an integrated bevel gear shaft is used, and the contact of the bevel gear shaft is adjusted by utilizing the axial clearance of the tapered roller bearing and the threaded locking method at the end of the bevel gear shaft. The integrated bevel gear shaft can reduce the force and damage to the fastening screws caused by vibration and improper displacement during use; in this embodiment, the threaded fastening method at the end of the tapered roller bearing and the bevel gear shaft can ensure that the meshing between the two bevel gears can be ensured by adjusting the axial position of the bevel gear shaft when there is a certain deviation in processing and installation.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The transmission structure of the robot arm is characterized by: The output shafts of the fourth axis motor (121), the fifth axis motor (122) and the sixth axis motor (123) of the mechanical arm are located on the same straight line; The transmission structure between the fourth-axis motor (121) and the fourth-axis reducer (13) comprises: A fourth-axis cylindrical spur gear (16), connected to the output shaft of the fourth-axis motor 121; A fourth shaft cylindrical internal gear (17), the inner ring of which is meshed with the fourth shaft cylindrical spur gear (16), and the fourth shaft reducer (13) is coaxially connected with the fourth shaft cylindrical internal gear (17); The transmission structure between the fifth-axis motor (122) and the fifth-axis reducer (8) comprises: A fifth-axis cylindrical spur gear (14), connected to the output shaft of the fifth-axis motor 122; A fifth shaft transmission shaft (20) comprises a first end and a second end, wherein the first end of the fifth shaft transmission shaft (20) is driven to rotate by the fifth shaft cylindrical spur gear (14) via a set of intermediate gear sets; the second end of the fifth shaft transmission shaft (20) is connected to the first end of the fifth shaft transmission tube (23); A fifth shaft transmission tube (23) comprises a first end and a second end, wherein the second end of the fifth shaft transmission tube (23) is connected to a fifth shaft bevel gear (24); A fifth-shaft bevel gear shaft (27) meshes with the fifth-shaft bevel gear (24), and the fifth-shaft reducer 8 is coaxially connected to the fifth-shaft bevel gear shaft (27); The transmission structure between the sixth-axis motor (123) and the sixth-axis reducer (7) comprises: A sixth-axis transmission shaft (21), comprising a first end and a second end, wherein the first end of the sixth-axis transmission shaft (21) is connected to the output shaft of the sixth-axis motor (123), and the second end of the sixth-axis transmission shaft (21) is connected to the first sixth-axis arc bevel gear shaft (22); A second six-axis arc bevel gear shaft (25) meshing with the first six-axis arc bevel gear shaft (22); The third six-axis arc bevel gear shaft (28) is meshed with the second six-axis arc bevel gear shaft (25); the sixth-axis reducer (7) is coaxially connected with the third six-axis arc bevel gear shaft (28).

2. The transmission structure according to claim 1, characterized in that: The fourth shaft reducer (13) and the fourth shaft cylindrical internal gear (17) are transmitted via a fourth shaft transmission spur gear shaft (18).

3. The transmission structure according to claim 1, characterized in that: The second end of the fifth shaft transmission shaft (20) is connected to the fifth shaft transmission tube (23) via a spline.

4. The transmission structure according to claim 1, characterized in that: The fifth-shaft bevel gear shaft (27) and the central axis of the fifth-shaft bevel gear (24) are perpendicular to each other.

5. The transmission structure according to claim 1, characterized in that: The fifth shaft transmission shaft (20) is in the shape of a hollow shaft, the sixth shaft transmission shaft (21) is arranged in the inner cavity of the fifth shaft transmission shaft (20), and the axes of the sixth shaft transmission shaft (21) and the fifth shaft transmission shaft (20) are parallel to each other.

6. The transmission structure according to claim 1, characterized in that: The second end of the sixth-axis transmission shaft (21) is connected to the first sixth-axis arc bevel gear shaft (22) via a spline.

7. The transmission structure according to claim 1, characterized in that: The central axis of the second six-axis arc-shaped bevel gear shaft (25) and the central axis of the first six-axis arc-shaped bevel gear shaft (22) are perpendicular to each other.

8. The transmission structure according to claim 1, characterized in that: The central axes of the third six-axis arc-shaped bevel gear shaft (28) and the second six-axis arc-shaped bevel gear shaft (25) are perpendicular to each other.

9. The transmission structure according to claim 1, characterized in that: Two second six-axis arc bevel gear shafts (25) are provided, and the two second six-axis arc bevel gear shafts (25) are driven by spur gears (26), wherein one of the second six-axis arc bevel gear shafts (25) is meshed with the first six-axis arc bevel gear shaft (22), and the other second six-axis arc bevel gear shaft (25) is meshed with the third six-axis arc bevel gear shaft (28).

10. The transmission structure according to claim 1, characterized in that: The tail end of the fifth-shaft bevel gear shaft (27) is provided with an external thread, and a nut is configured to be connected to the external thread at the tail end of the fifth-shaft bevel gear shaft (27); and / or The tail end of the second six-axis arc bevel gear shaft (25) is provided with an external thread, and a nut is configured to be connected to the external thread at the tail end of the fifth-axis bevel gear shaft (27).

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