CN111805572B

CN111805572B - Robot joint

Info

Publication number: CN111805572B
Application number: CN202010697824.4A
Authority: CN
Inventors: 丁伟; 田坤淼; 蔡国庆; 萧汉标; 黄毅; 齐玉乐; 王星; 何权富; 周文
Original assignee: Borunte Robot Co Ltd
Current assignee: Borunte Robot Co Ltd
Priority date: 2020-07-20
Filing date: 2020-07-20
Publication date: 2021-07-02
Anticipated expiration: 2040-07-20
Also published as: CN111805572A

Abstract

A robot joint comprises a motor, a transmission gear set, a speed reducer and a wire passing shaft; the motor drives the speed reducer to rotate through the transmission gear set; the speed reducer is provided with a wire passing channel connected between the input end and the output end of the speed reducer; the wire passing shaft is provided with a through hole extending along the axis of the wire passing shaft, penetrates through the wire passing channel and is fixed with the output end of the speed reducer. Compared with the prior art, the robot joint has the advantages that the control assembly line passes through the hollow wire passing shaft fixed with the output end of the speed reducer, and the rotating speed of the wire passing shaft is low due to the low speed of the output end of the speed reducer, so that the friction force between the wire passing shaft and the control assembly line is reduced, and the abrasion of the control assembly line is reduced.

Description

Robot joint

Technical Field

The invention relates to the field of robots, in particular to a robot joint.

Background

With the development of industrialization, robots are applied deeply and increasingly demanding. The robot is required to complete various actions in the processing process, so the requirement on the flexibility of the robot joint is higher and higher. Referring to fig. 1, fig. 1 is a schematic diagram illustrating an overall structure of a robot in the prior art, which includes a base 1, a large arm 2, a joint 3, a robot arm 4 and a control assembly (not shown). The large arm 2 is arranged on the base 1, and the base 1 drives the large arm 2, the joint 3 and the mechanical arm 4 to rotate around the axis of the base 1. The joint 3 is connected between the large arm 2 and the mechanical arm 4, and the axes of the large arm 2 and the mechanical arm 4 are perpendicular to each other to realize the change of the motion direction. The large arm 2 swings to drive the joint 3 and the mechanical arm 4 to move. The joint 3 drives the mechanical arm 4 to rotate around the axis of the mechanical arm, and the joint 3 controls the mechanical arm 4 to rotate around the axis of the mechanical arm, so that machining is performed. The control group wires pass through the large arm 2, the joint 3 and the mechanical arm 4 from the base 1 respectively to supply power and control to each part of the robot.

The joint 3 is located between the large arm 2 and the mechanical arm 4 and drives the mechanical arm 4 to rotate, in order to improve the flexibility of the joint, most of the wiring of the robot joint in the current market adopts a hollow wiring mode, a hollow structure is arranged at the position of the robot joint, and the control wiring penetrates through the hollow structure to realize wiring.

Referring to fig. 2, patent application No. 201620436025.0 discloses an internal motor gear structure of a multi-axis robot with a built-in cable, which includes a motor 20, a transmission gear set 30, a transmission shaft 80 and a speed reducer 40. The transmission gear set 30 is provided with a pair of gears which are meshed with each other, the motor 20 is connected with one gear in the transmission gear set 30 through a coupler, and the transmission shaft 80 is arranged on the other gear in the transmission gear set 30 and rotates coaxially with the other gear. The input end of the speed reducer 40 is fixed on the transmission shaft 80 and rotates therewith, so that transmission from the motor 20 to the speed reducer 40 is realized, and the speed reducer 4 drives the mechanical arm and other loads to move. The transmission shaft 80 is a hollow structure, and the control group wire passes through the middle of the transmission shaft 80 to realize wiring.

As can be seen from the above structure, the transmission shaft rotates with the rotation of the motor in the robot joint in the prior art. The rotating speed of the motor is generally high, so that the speed of the transmission shaft is also high, the rotating shaft rotating at high speed generates large friction force for passing through the control group line in the middle of the rotating shaft, the control group line is easy to wear, and the control group line needs to be detected and replaced according to statistics about 6 months generally. Further, the transmission shaft is connected between the motor and the speed reducer as a transmission part, so that the distance between the motor and the speed reducer is increased, the overall size of the joint is increased, and certain energy loss can be brought by a transmission mode through the transmission shaft. In addition, the transmission shaft is required to be made of a rigid material such as stainless steel as a transmission component.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a robot joint capable of reducing wear of a control wire set.

The technical scheme adopted by the invention is as follows:

a robot joint comprises a motor, a transmission gear set, a speed reducer and a wire passing shaft; the motor drives the speed reducer to rotate through the transmission gear set; the speed reducer is provided with a wire passing channel connected between the input end and the output end of the speed reducer; the wire passing shaft is provided with a through hole extending along the axis of the wire passing shaft, penetrates through the wire passing channel and is fixed with the output end of the speed reducer.

Compared with the prior art, the control assembly line in the robot joint passes through the wire passing shaft fixed with the output end of the speed reducer, and the rotating speed of the wire passing shaft is lower due to the low speed of the output end of the speed reducer, so that the friction force between the wire passing shaft and the control assembly line is reduced, and the abrasion of the control assembly line is reduced.

Furthermore, the speed reducer is also provided with a speed reduction gear set and an output flange; the transmission gear set is meshed with the input end of the reduction gear set; the wire passing channel is arranged in the reduction gear set; the output flange is fixed with the output end of the reduction gear set, and one end of the wire passing shaft is fixed on the output flange. The output flange is connected with the mechanical arm in an equal-load mode, and transmission is achieved.

Further, the material of the wire through shaft is self-lubricating nylon, and the inner surface of the wire through shaft is polished. The nylon material with lubricity is soft, and compared with a rigid material, the abrasion of the control group line is further reduced.

The wire fixing pile is fixed on the inner surface of the wire passing shaft. The line fixing pile separates the control line from the inner surface of the wire passing shaft, and friction between the control line and the inner surface of the wire passing shaft is further reduced.

Further, the wire fixing pile is malleable. The ductile wire fixing pile can reduce the friction between the control wire and the wire fixing pile.

Furthermore, the number of the wire fixing piles is more than two so as to support and control the wire assembly. The oppositely arranged wire fixing piles prevent the control wire assembly from shaking in the wire passing shaft.

Further, the seal assembly includes a static seal and a dynamic seal; the static sealing element is sleeved on the wire passing shaft and is fixed between the end surface of the wire passing shaft and the speed reducer; the movable sealing element is sleeved at the other end of the wire passing shaft, and the wire passing shaft rotates relative to the movable sealing element. The dynamic and static matching seal prevents the leakage of the lubricating oil.

Further, the static sealing element is an O-shaped sealing ring; the dynamic sealing element is an oil seal.

Further, the spool is supported by a bearing, and the bearing is located between the static seal and the dynamic seal. The bearing supports the wire passing shaft to prevent the deformation of the wire passing shaft.

Furthermore, a bearing part for mounting the bearing and a dynamic seal matching part for mounting the dynamic seal are arranged on the wire passing shaft; the bearing portion is located beside the dynamic seal matching portion, and the outer diameter of the bearing portion is larger than that of the dynamic seal matching portion. The bearing portion has an outer diameter greater than an outer diameter of the dynamic seal engaging portion to restrict movement of the dynamic seal relative to the spool.

For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of an overall structure of a robot in the prior art;

FIG. 2 is a schematic diagram of a prior art internal motor gear of a multi-axis robot with a built-in cable;

FIG. 3 is a schematic view of the overall structure of the robot joint according to the present invention;

FIG. 4 is a partial enlarged view of a reduction gear of a robot joint according to the present invention;

FIG. 5 is a schematic structural view of a spool according to the present invention;

fig. 6 is a partially enlarged view of a bobbin according to the present invention.

Detailed Description

Referring to fig. 3 and 4, the robot joint of the present invention includes a housing 10, and a motor 20, a transmission gear set 30, a speed reducer 40, and a wire shaft 50 disposed in the housing 10. The motor 20 is fixed in the housing 10 to output rotation. The transmission gear set 30 is provided with a pair of gears which are meshed with each other, one gear in the transmission gear set 30 is fixed at the output end of the motor 20, the other gear is fixed at the input end of the speed reducer 40, and the motor 20 drives the speed reducer 40 to rotate through the transmission gear set 30. The speed reducer 40 is provided with a wire passage 410, an output flange 420 and a reduction gear set 430, the reduction gear set 430 is fixed in the housing 10, the start end of the reduction gear set is used as the input end of the speed reducer 40 and is meshed with the transmission gear set 30, the output flange 420 is installed at the tail end of the reduction gear set 430 and is used as the output end of the speed reducer 40, and loads (not shown) such as mechanical arms and the like are connected with the output flange 420 through screws, so that the output flange 420 drives the loads to rotate. The wire passage 410 is provided in the reduction gear set 430 and communicates its input end with its output end. The wire passing shaft 50 passes through the wire passing channel 410, and one end thereof is fixed to the output end of the speed reducer 40 by a screw or the like. A through hole extending along the axis of the spool 50 is formed in the spool 50, and the control group wire passes through the through hole of the spool 50; preferably, since the load is driven by the output flange, the spool 50 is no longer used as a transmission component, and therefore, the spool can be made of a self-lubricating nylon material with high flexibility and the inner surface of the spool is polished.

Further, in order to reduce the friction between the control wire assembly and the inner surface of the bobbin 50 during operation, a wire fixing pile 60 is arranged, the wire fixing pile 60 is fixed on the inner surface of the bobbin 50 and protrudes, the wire fixing pile 60 is made of a shock absorption material with ductility, such as foam, sponge, rubber and the like, and the control wire assembly passes through the wire fixing pile 60, so that the friction between the control wire assembly and the inner surface of the bobbin 50 during operation is reduced; further, the number of the wire fixing piles 60 is more than two, and the wire fixing piles are uniformly distributed along the inner surface of the wire passing shaft 50; preferably, every two wire fixing piles 60 are oppositely arranged along the radial direction of the wire passing shaft, the control wire assembly is positioned between the two opposite wire fixing piles 60, and the control wire assembly is positioned between the two wire fixing piles 60 so as to reduce the shaking of the control wire assembly; further, more than two wire fixing piles 60 are arranged along the axial direction of the bobbin 50 to support the control wire assembly, and preferably, the wire fixing piles 60 are provided at both ends of the bobbin 50 to further prevent them from contacting the inner surface of the bobbin 50,

further, lubricating oil is often added to the connecting part from the output end of the motor 20 to the output end of the speed reducer 40 to improve the transmission effect and reduce the damage of equipment. In order to prevent the leakage of lubricating oil, the robot joint further comprises a sealing assembly 70, wherein the sealing assembly 70 comprises a static sealing element 710 and a dynamic sealing element 720 which are respectively installed at two ends of the wire passing shaft 50, and the output end of the motor 20 and the output end of the speed reducer 40 are both located between the static sealing element 710 and the dynamic sealing element 720, so that the joint is sealed.

In one embodiment, referring to fig. 4 to 6, the speed reducer 40 is a harmonic speed reducer, and the output flange 420 is sleeved outside the wire passing shaft 50 and the axes thereof are coincident. The spool 50 has a fixing portion 510, a dynamic seal engaging portion 520, and a bearing portion 530. The fixing portion 510 is disposed at an end of the spool 50, an outer diameter of the fixing portion 510 is greater than an outer diameter of a shaft body of the spool 50, and a screw passes through the fixing portion 510 and then is in threaded connection with the output flange 420, so that the spool 50 is fixed to an output end of the speed reducer 40, and the spool 50 and the reduction gear set 430 rotate coaxially. The static sealing element 710 is an O-ring and tightly sleeved on the outer side of the spool 50 and pressed between the fixing portion 510 and the output flange 420, and the static sealing element 710 rotates along with the rotation of the spool 50, i.e., is static relative to the spool 50, thereby achieving static sealing. The dynamic seal matching part 520 is arranged at the other end of the wire passing shaft 50, the dynamic seal 720 is an oil seal, the dynamic seal 720 is sleeved on the outer side of the dynamic seal matching part 520 and is fixed in the shell 10, and the wire passing shaft 50 rotates relative to the dynamic seal 720, so that the rotary seal is realized. The bearing part 530 is disposed between the fixing part 510 and the dynamic seal matching part 520, and a bearing fixed in the housing 10 is sleeved outside the bearing part 530 to support the wire passing shaft 50; preferably, the outer diameter of the bearing part 530 is larger than that of the dynamic seal matching part 520, and the dynamic seal 720 is located beside the bearing part 530, so that a positioning step is formed on the outer side of the bobbin 50 to limit the dynamic seal 720 from moving axially along the bobbin 50. The spool 50 and the seal assembly 70 may be connected to a different type of speed reducer such as an RV speed reducer.

Compared with the prior art, the hollow wire passing shaft of the robot is connected with the output end of the speed reducer and is no longer used as a transmission part, the rotating speed of the wire passing shaft is reduced, the friction force on the control wire assembly is reduced, the abrasion on the control wire assembly is reduced, and the service life of the control wire assembly is prolonged from 6 months to about 2 years due to the arrangement of the wire fixing piles. Meanwhile, the wire passing shaft is arranged in the speed reducer, so that the occupied space can be reduced, and the size of the joint can be compacted. And the transmission mode that the motor is directly connected with the speed reducer to drive the load is simple and direct, and the energy consumption in the transmission process can be reduced. And a sealing assembly is further arranged to prevent the leakage of lubricating oil from the output end of the motor to the output end of the speed reducer. And the sealing effect is guaranteed under the condition that the dynamic and static combined sealing element does not hinder normal operation. In addition, the wire guide tube is supported by the bearing to prevent the wire guide tube from being deformed due to long-term movement. The robot joint is simple in structure, easy to realize and suitable for different types of speed reducers.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims

1. A robot joint is characterized by comprising a motor, a transmission gear set, a speed reducer and a wire passing shaft; the motor drives the speed reducer to rotate through the transmission gear set; the speed reducer is provided with a wire passing channel connected between the input end and the output end of the speed reducer; the wire passing shaft is provided with a through hole extending along the axis of the wire passing shaft, penetrates through the wire passing channel and is fixed with the output end of the speed reducer; the inner surface of the wire passing shaft is provided with a wire fixing pile; the number of the wire fixing piles is more than two, and the wire fixing piles are oppositely arranged along the radial direction of the wire passing shaft, so that the control wire assembly passes through the wire fixing piles.

2. A robot joint according to claim 1, characterized in that the reducer is further provided with a reduction gear set and an output flange; the transmission gear set is meshed with the input end of the reduction gear set; the wire passing channel is arranged in the reduction gear set; the output flange is fixed with the output end of the reduction gear set, and one end of the wire passing shaft is fixed on the output flange.

3. The robot joint of claim 2, wherein the material of the spool is self-lubricating nylon and the inner surface is polished.

4. The robotic joint of claim 3, wherein the wire fixation peg is malleable.

5. The robotic joint of claim 1, further comprising a seal assembly comprising a static seal and a dynamic seal; the static sealing element is sleeved on the wire passing shaft and is fixed between the end surface of the wire passing shaft and the speed reducer; the movable sealing element is sleeved at the other end of the wire passing shaft, and the wire passing shaft rotates relative to the movable sealing element.

6. A robotic joint according to claim 5, wherein the static seal is an O-ring seal; the dynamic sealing element is an oil seal.

7. The robotic joint of claim 6, wherein the spool is supported by a bearing, and the bearing is located between the static seal and the dynamic seal.

8. The robot joint of claim 7, wherein the spool has a bearing portion for mounting the bearing and a dynamic seal engaging portion for mounting the dynamic seal; the bearing portion is located beside the dynamic seal matching portion, and the outer diameter of the bearing portion is larger than that of the dynamic seal matching portion.