CN114131645A

CN114131645A - Variable-rigidity flexible joint based on through shaft

Info

Publication number: CN114131645A
Application number: CN202111477615.XA
Authority: CN
Inventors: 陈令凯; 张兰; 黄冠宇; 孔令雨; 蔡建东; 谢安桓; 张丹
Original assignee: Zhejiang Lab
Current assignee: Zhejiang Lab
Priority date: 2021-12-06
Filing date: 2021-12-06
Publication date: 2022-03-04
Anticipated expiration: 2041-12-06
Also published as: CN114131645B

Abstract

The invention discloses a variable-rigidity flexible joint based on a through shaft, which solves the problems of complexity and large size of a flexible joint rigidity adjusting mechanism and adopts the technical scheme that the variable-rigidity flexible joint comprises a joint motor and an adjustable-rigidity mechanism, wherein the adjustable-rigidity mechanism comprises a rigidity adjusting motor, a driving shaft, a rigidity adjusting mechanism, an elastic piece and a joint output end, the joint motor is provided with the through shaft for accommodating the driving shaft and a motor output end for outputting the torque of the joint motor, the rigidity adjusting motor is fixedly arranged on a tail shell of the joint motor, the rigidity adjusting mechanism is arranged between the joint output end and the motor output end, two ends of the driving shaft are respectively and fixedly connected with the rigidity adjusting motor and the rigidity adjusting mechanism, the driving shaft is coaxial with the joint motor, and the elastic piece is connected with the rigidity adjusting mechanism and the joint output end, so that the radial size of the variable-rigidity flexible joint is reduced by fully utilizing the through shaft of the joint motor .

Description

Variable-rigidity flexible joint based on through shaft

Technical Field

The invention relates to the field of flexible joints of robots, in particular to a variable-rigidity flexible joint based on a through shaft.

Background

Compared with the traditional flexible joint, the variable-rigidity flexible joint can realize the change of the joint rigidity of the robot in different working states through a certain control strategy, has similar characteristics with human muscles, namely keeps higher rigidity in a common working state, can generate certain flexibility when collision occurs, relieves collision impact, and prevents further damage to a contact object. In addition, due to the introduction of the elastic element, the joint can store energy during collision, and the utilization efficiency of the energy is improved to a certain extent, so that due to the introduction of the flexible joint with variable rigidity, the robot has environmental safety while the movement performance of the joint is ensured, and has wide application background and important research significance under the large backgrounds of 'industry 4.0' and 'Chinese manufacturing 2025' in the current mechanical industry.

The invention patent with the patent number of 201721547542.6 discloses a flexible joint with variable rigidity based on a lever mechanism, which comprises a joint driving end, a rigidity adjusting mechanism and a joint output end, wherein the joint driving end is used for providing power required by driving the joint to move; the two ends of the rigidity adjusting mechanism are respectively and rigidly connected with the joint driving end and the joint output end, the joint output end is connected with the joint load, and the joint output end is provided with an output encoder; the joint driving end comprises a joint support, a harmonic reducer and a joint driving motor provided with an encoder. The rigidity adjusting motor is arranged at the output end of the joint motor, so that the rigidity adjusting motor is required to be small in size, the axial size of the rigidity adjusting mechanism is increased, and the installation of the joint motor is not facilitated.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a variable-rigidity flexible joint based on a through shaft.

In order to realize the purpose of the invention, the invention adopts the following technical scheme: a variable-rigidity flexible joint based on a through shaft comprises a joint motor and an adjustable rigidity mechanism, wherein the adjustable rigidity mechanism comprises a rigidity adjusting motor, a rigidity adjusting mechanism, an elastic piece and a joint output end; the joint motor is provided with a through shaft; the rigidity adjusting motor is connected with the joint motor; a driving shaft of the rigidity adjusting motor is fixedly connected with the rigidity adjusting mechanism; the rigidity adjusting mechanism is connected with the output end of the joint motor; one end of the elastic piece is connected with the rigidity adjusting mechanism, and the other end of the elastic piece is connected with the joint output end.

Further, the joint motor and the rigidity adjusting motor are coaxially arranged; and the through shaft of the joint motor is used for placing a driving shaft of the rigidity adjusting motor.

Further, the elastic element is a spring or a reed.

Further, the output end of the joint motor and the joint output end are coaxially arranged.

Furthermore, the joint output end is correspondingly provided with a joint output end constraint mechanism for ensuring that the joint output end rotates around the axis.

Compared with the prior art, the variable-rigidity flexible joint based on the through shaft has the following beneficial effects that:

1. by adopting the variable-rigidity flexible joint based on the through shaft, the radial size of the variable-rigidity flexible joint is reduced, the variable-rigidity flexible joint and a common integrated joint can share a mounting surface, so that interchange is realized, and the modular design and use of the variable-rigidity flexible joint are facilitated;

2. by adopting the variable-rigidity flexible joint based on the through shaft, the hollow shaft of the joint motor is fully expanded and utilized, and the installation space including the installation space of the variable-rigidity flexible joint and the installation space of the rigidity adjusting motor is saved to the maximum extent.

3. By adopting the variable-rigidity flexible joint based on the through shaft, the appearance of the variable-rigidity flexible joint can be closer to a mature integrated product without adding extra space by adjusting the overall dimensions of the joint motor and the rigidity adjusting motor, rather than stacking two functional modules.

4. By adopting the rigidity-adjustable flexible joint based on the through shaft, the axial size of the rigidity-adjustable mechanism is smaller, so that the joint motor is closer to the mounting plate, the stress condition of the motor is favorably improved, and the layout is more reasonable.

Drawings

FIG. 1 is a schematic cross-sectional structural view of an embodiment of a variable stiffness flexible joint based on a through shaft according to the present invention;

FIG. 2 is a schematic view of a partial cross-sectional structure of an embodiment of a through-axis-based variable stiffness flexible joint of the present invention.

Reference numerals: 1. a joint motor; 11. a through shaft; 12. a motor output end; 13. a motor tail shell; 21. a stiffness adjustment motor; 22. a drive shaft; 23. a stiffness adjustment mechanism; 24. an elastic member; 25. a joint output end; 26. a cavity; 27 output end restraining means.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The through shaft-based variable-stiffness flexible joint shown in fig. 1 and 2 comprises a joint motor 1 and an adjustable stiffness mechanism, wherein the adjustable stiffness mechanism 2 comprises a stiffness adjusting motor 21, a driving shaft 22, a stiffness adjusting mechanism 23, an elastic piece 24 and a joint output end 25. The joint motor 1 and the rigidity adjustable mechanism 2 are coaxially arranged. The joint motor 1 is provided with a through shaft 11 for accommodating the driving shaft 22 and a motor output end 12 for outputting a joint motor torque. The rigidity adjusting motor 21 is connected with the joint motor 1 and is fixedly arranged on a motor tail shell 13 of the joint motor. The end of the driving shaft 22 of the stiffness adjusting motor 21 is fixedly connected with the stiffness adjusting mechanism 23, that is, the driving shaft 22 drives the stiffness adjusting mechanism 23 to rotate around the shaft. The rigidity adjusting mechanism 23 is arranged between the joint output end 25 and the motor output end 12, and the rigidity adjusting mechanism 23 is connected with the output end 12 of the joint motor 1; one end of the elastic piece 24 is connected with the rigidity adjusting mechanism 23, and the other end is connected with the joint output end 25. The joint output end 25 is of a cover-shaped structure, and the rigidity adjusting mechanism 23 and the elastic piece 24 are located in the cover-shaped structure of the joint output end 25. And a cover opening of the cover-shaped structure of the joint output end 25 is provided with a circular inward protruding structure serving as a joint output end constraint mechanism 27 for ensuring that the joint output end 25 rotates around the axis. A cavity 26 is formed between the stiffness adjustment mechanism 23 and the joint output 25. The joint output end restriction mechanism 27 is rotatably connected with the motor output end 25.

Further, the through shaft of the joint motor can be divided into two or three sections according to whether the hollow shaft section of the joint motor corresponding to the rotor part is integrated with the central through hole of the joint output end 12. Wherein, the through shaft of joint motor can be by three sections constitutions, specifically is: the tail part of the rigidity adjusting motor is arranged in a tail hole on the axis of the joint motor, and a hollow shaft and a joint output end which correspond to a rotor part of the middle joint motor are arranged in a through hole on the axis of the joint motor. The through shaft of the joint motor can be composed of two sections, specifically: the tail part of the rigidity adjusting motor is arranged in a tail hole on the axis of the joint motor, and the joint output end and the extension shaft thereof are arranged in a through hole on the axis of the joint motor.

In conclusion, the variable-rigidity flexible joint based on the through shaft provided by the invention reduces the radial size of the variable-rigidity flexible joint, fully expands the hollow shaft using the joint motor, saves the installation space to the maximum extent, reduces the radial size of the variable-rigidity flexible joint, not only can the variable-rigidity flexible joint and a common integrated joint share the installation surface, but also realizes interchange, and is more beneficial to the modular design and use of the variable-rigidity flexible joint; the motor stress condition is improved, and the layout is more reasonable.

The foregoing is a preferred embodiment of the present invention, and it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.

Claims

1. The variable-rigidity flexible joint based on the through shaft is characterized by comprising a joint motor (1) and an adjustable rigidity mechanism, wherein the adjustable rigidity mechanism comprises a rigidity adjusting motor (21), a rigidity adjusting mechanism (23), an elastic piece (24) and a joint output end (25); the joint motor (1) and the rigidity-adjustable mechanism (2) are coaxially arranged; the joint motor (1) is provided with a through shaft (11); the rigidity adjusting motor is positioned at the rear end of the joint motor (1); a driving shaft (22) of the rigidity adjusting motor (21) penetrates through the through shaft (11) and is fixedly connected with the rigidity adjusting mechanism (23); the rigidity adjusting mechanism (23) is connected with the output end (12) of the joint motor (1); one end of the elastic piece (24) is connected with the rigidity adjusting mechanism (23), and the other end of the elastic piece is connected with the joint output end (25).

2. Through-shaft based variable stiffness flexible joint according to claim 1, characterized in that the joint motor (1) is arranged coaxially with a stiffness adjustment motor (21).

3. Through-shaft based variable stiffness flexible joint according to claim 1, characterized in that the joint output (25) is a cap like structure, the stiffness adjustment mechanism (23) and the elastic member (24) being located within the cap like structure of the joint output (25).

4. Through-shaft based variable stiffness flexible joint according to claim 1, characterized in that the elastic member (24) is a spring or a reed.

5. Through-shaft based variable stiffness flexible joint according to claim 1, characterized in that the output (12) of the joint motor (1) is arranged coaxially with the joint output (25).

6. The through-shaft-based variable-stiffness flexible joint according to claim 1, wherein the joint output end (25) is correspondingly provided with a joint output end constraint mechanism (27) for ensuring that the joint output end (25) rotates around the shaft center.