CN111376303A

CN111376303A - Three-degree-of-freedom rope wheel driving joint and mechanical arm

Info

Publication number: CN111376303A
Application number: CN201811616374.0A
Authority: CN
Inventors: 徐方; 李学威; 何元一; 李加平; 武桐; 邵伟翔
Original assignee: Shenyang Siasun Robot and Automation Co Ltd
Current assignee: Shenyang Siasun Robot and Automation Co Ltd
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2020-07-07
Anticipated expiration: 2038-12-27
Also published as: CN111376303B

Abstract

The application discloses three degree of freedom rope sheave drive joints include: the method comprises the following steps: elbow joint, I level drive mechanism, II level drive mechanism, III level drive mechanism and IV level drive mechanism, I level drive mechanism includes: i level flange that is connected with elbow joint installs J2 wrist pitch driving motor and J1 wrist gyration driving motor on I level flange, and II level drive mechanism includes: a J2-II grade driving wheel and a J1-II grade driving wheel which are fixedly connected with the I grade connecting flange, the J2-I grade driven wheel and the J1-I grade driven wheel respectively; the III-stage transmission mechanism comprises: a grade III connecting flange, a grade J2-III driving wheel and a grade J1-III driving wheel which are respectively connected with the grade J1-II driven wheel and the grade J2-II driven wheel. The motor directly links with the line wheel in this application, does not decelerate through the speed reducer, directly utilizes the rope sheave to realize from power end to terminal power take off and the speed reduction process, has thoroughly avoided because of the absolute error and the return stroke difference that multistage transmission system produced.

Description

Three-degree-of-freedom rope wheel driving joint and mechanical arm

Technical Field

The application relates to the technical field of mechanical arms, in particular to a three-degree-of-freedom rope wheel driving joint and a mechanical arm.

Background

At present, most widely used robots adopt a driving mode of direct driving of gears and shafts or motor accelerators, and a driving force on joints is transmitted to a transmission system required by the tail ends of the joints, so that the weight of an arm body structure is increased, and the efficiency in a power transmission process is reduced. The driving mode of directly integrating power on the joint applies the weight of the motor and the speed reducer on the moving joint, and greatly increases the motion inertia of the joint. Meanwhile, the motion clearances exist in the existing transmission systems such as gear transmission, belt wheel transmission, lead screw transmission and the like, so that motion idle stroke and return stroke difference are inevitable to be generated, and the motion precision of the robot is influenced. The existing rope wheel driving robots are mostly in parallel connection type due to the complexity of a transmission structure, and the series rope wheel driving robots are quite rare. At present, similar products are not available in China, and development records of the mechanical arm driven by the full rope pulley are not available.

Content of application

The application aims to overcome the defects in the prior art, and provides the following technical scheme:

this application first aspect provides a three degree of freedom rope sheave drive joint, is applied to in the arm, includes: the elbow joint, the I-stage transmission mechanism, the II-stage transmission mechanism, the III-stage transmission mechanism and the IV-stage transmission mechanism;

the class I transmission mechanism comprises: the I-grade connecting flange is connected with the elbow joint, and the J2 wrist pitching driving motor and the J1 wrist revolving driving motor are arranged on the I-grade connecting flange; the J2-I grade driving wheel and the J1-I grade driving wheel respectively form transmission with the J2-I grade driving wheel and the J1-I grade driving wheel through steel wire ropes and generate a J2-I grade driven wheel and a J1-I grade driven wheel with reduction ratios; bearings are mounted at the ends of the output wheels, so that an I-stage transmission machine integrating transmission and speed reduction is formed;

the II-stage transmission mechanism comprises: the J2-II driving wheel and the J1-II driving wheel form transmission with the J1-II driven wheel and the J2-II driven wheel respectively through steel wire ropes and generate a certain reduction ratio;

the class III transmission comprises: the J2-III driving wheel and the J1-III driving wheel are respectively in transmission with the J1-III driven wheel and the J2-III driven wheel through steel wire ropes and generate a certain reduction ratio;

the IV stage transmission mechanism comprises: the J2-IV stage driven wheel and the J2-IV stage driving wheel are arranged at a right angle, the steel wire rope is wound in an upper layer and a lower layer, and the J2-IV stage driven wheel is connected with a J3 wrist joint in the mechanical arm so as to realize pitching motion of the wrist joint.

Optionally, the elbow joint is connected with the class I connecting flange by screws.

Optionally, the J2-I stage driving wheel and the J1-I stage driving wheel are respectively in transmission with the J2-I stage driven wheel and the J1-I stage driven wheel through a 0.6mm steel wire rope and generate a reduction ratio of 10: 3.

Optionally, the J2-II stage driving wheel and the J1-II stage driving wheel form transmission with the J1-II stage driven wheel and the J2-II stage driven wheel respectively through a 0.8mm steel wire rope and generate a reduction ratio of 4: 1.

Optionally, the J2-III driving wheel and the J1-III driving wheel are respectively in transmission with the J1-III driven wheel and the J2-III driven wheel through 1.2mm steel ropes and generate a reduction ratio of 4: 1.

Optionally, the steel wire rope is fixed at one end of the driving wheel through a driving wheel steel wire rope fixing part, and the tensioning of the rope end is achieved at one end of the driven wheel through a driven wheel tensioning screw.

Optionally, the driven J1-III gears and the driven J2-III gears in the III gear are axially aligned.

A second aspect of the embodiments of the present application provides a mechanical arm, where the mechanical arm includes any one of the three-degree-of-freedom rope pulley drive joints, a wrist joint connected to the three-degree-of-freedom rope pulley drive joint, and a front end revolute joint.

Optionally, the mechanical arm includes an aluminum hollow flange, and the three-degree-of-freedom sheave driving joint is disposed at a proper position of the aluminum hollow flange.

Optionally, the wrist joint and the front end revolute joint include: j3 wrist joint flange, J2-III driven wheel tensioning piece, J3 rotary joint driven wheel, J3 rotary bearing fixing flange, tail end output flange, J3 wrist joint, J2-IV driven wheel, J1 rotary flange, J3 wrist connecting flange, J3 rotary joint driving wheel, J3 joint reducer, J2 wrist pitching flange, J3 joint driving motor and J2-IV driving wheel;

wherein: the J3 joint driving motor is fixed on a J3 wrist joint, and transmits power to a J3 rotary joint driving wheel after being decelerated by a J3 joint decelerator; the J3 rotary joint driving wheel and the J3 rotary joint driven wheel form transmission through a 0.8mm steel wire rope and generate a reduction ratio of 2: 1.

The technical effects of this application: the three-degree-of-freedom rope wheel driving joint in the application realizes a high-precision joint which is driven by a motor to move and a tail end load by using a full-province wheel driving mode. Compare in current rope wheel drive arm, the motor directly links with the line wheel in this application, does not slow down through the speed reducer, directly utilizes the rope sheave to realize from power end to terminal power take off and the process of slowing down, has thoroughly avoided because of the absolute error and the return stroke difference that multistage transmission system produced. Meanwhile, due to the superiority of rope wheel driving, the motor can be directly arranged at the joint, and the transmission distance is adjusted by the steel wire rope, so that the problem of large self weight of a transmission system caused by long transmission distance is solved. Because the rope pulley transmission belongs to flexible transmission, the rigid collision with a barrier or a human body can be effectively avoided in the operation process of the mechanical arm, and the mechanical arm is more suitable for the work of human-computer interaction and the like. The robot can be integrated on a mobile device and used for grabbing objects or assisting the old with mobility disorder and the like. Meanwhile, the multi-joint integration can be realized to form a multi-freedom-degree mechanical arm, and the multi-freedom-degree mechanical arm is applied to the work of desktop-level man-machine interaction, cooperation, teaching and the like. Due to the adoption of the layered modular design, different assembly modes can be adopted according to different use environments and loads, and the assembly requirement of the rope wheel drive is low, so that the assembly difficulty is greatly reduced, and the application range of the rope wheel drive is effectively expanded.

Drawings

Fig. 1 is a schematic overall structure diagram of a three-degree-of-freedom sheave drive joint according to an embodiment of the present application;

fig. 2 is a structural diagram of a three-degree-of-freedom rope pulley driving joint provided in an embodiment of the present application;

fig. 3 is a supplementary structure diagram of a three-degree-of-freedom rope pulley drive joint provided in the embodiment of the present application;

fig. 4 is a detailed schematic view of an I-stage transmission mechanism in a three-degree-of-freedom sheave drive joint according to an embodiment of the present disclosure;

fig. 5 is a detailed schematic view of a II-stage transmission mechanism in a three-degree-of-freedom sheave drive joint according to an embodiment of the present application;

fig. 6 is a detailed schematic view of a class III transmission mechanism in a three-degree-of-freedom sheave drive joint according to an embodiment of the present application;

fig. 7 is a detailed schematic view of an IV-stage transmission mechanism in a three-degree-of-freedom sheave drive joint according to an embodiment of the present application;

FIG. 8 is a detailed view of the transmission design of the wrist joint in the robot arm according to the embodiment of the present application;

fig. 9 is an exploded view of an overall assembly wire frame of a three-degree-of-freedom rope pulley drive joint provided in an embodiment of the present application;

FIG. 10 is an exploded view of a wrist of a robotic arm provided in an embodiment of the present application;

FIG. 11 is a structural view of an IV stage transmission provided by embodiments of the present application;

FIG. 12 is a structural view of a class III drive provided by an embodiment of the present application;

FIG. 13 is a structural view of a class II drive mechanism provided in an embodiment of the present application;

FIG. 14 is a structural view of a stage I transmission provided by an embodiment of the present application;

fig. 15 is a structural view of a three-degree-of-freedom rope sheave drive joint after a steel wire rope is added according to an embodiment of the present application.

The reference numbers related to the embodiments of the present application are as follows: 1. elbow joint, 2, I-grade connecting flange, 3, J2 wrist pitching driving motor, 4, J2-I-grade driven wheel, 5, driving wheel wire rope fixing piece, 6, J2-I-grade driving wheel, 7, III-grade connecting flange, 8, J2-II-grade driving wheel, 9, IV-grade connecting flange, 10, J1-III-grade driven wheel, 11, J2-III-grade driven wheel, 12, J3 wrist joint flange, 13, J2-III-grade driven wheel tensioning piece, 14, J3 rotary joint driven wheel, 15, J3 rotary bearing fixing flange, 16, tail end output flange, 17, J3 wrist joint, 18, J2-IV-grade driven wheel, 19, J1 rotary flange, 20, J1-III-grade driving wheel, 21, J1-II-grade driven wheel, 22, J1-II-grade driving wheel, 23, driven wheel tensioning screw, 24, II-grade connecting flange, 25. the device comprises a J1-I stage driven wheel, 26, J1-I stage driving wheels, 27, an elbow joint small bearing fixing flange, 28, J3 wrist connecting flange, 29, J3 rotary joint driving wheels, 30, J3 joint speed reducers, 31, J2 wrist pitching flanges, 32, J3 joint driving motors, 33, J2-IV stage driving wheels, 34, J2-III stage driving wheels, 35, J2-II stage driven wheels, 36, J1 wrist rotary driving motors, 37 and an elbow joint large bearing fixing wheel.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the application and do not constitute a limitation on the application.

The application provides a novel arm. The whole arm mainly comprises a J1 wrist rotary joint, a J2 wrist pitching hanging joint and a J3 front end rotary joint, wherein each joint is composed of an aluminum alloy flange structure, a wire wheel and a steel wire rope transmission mechanism. Wherein the driving elements of the J1 and J2 joints are arranged in 4 stages in an arm consisting of aluminum hollowed flanges, namely a stage I power input unit, a stage II reduction transmission unit, a stage III transmission reduction unit and a stage IV transmission unit.

The I-stage power input unit comprises: the wrist joint fixing device comprises an elbow joint, an I-grade connecting flange, a J2 wrist pitching driving motor, a J1 wrist revolving driving motor, an elbow joint small bearing fixing flange and an elbow joint large bearing fixing wheel; the II-stage reduction transmission unit mainly comprises: the device comprises a J2-I grade driven wheel, a driving wheel steel wire rope fixing piece, a J2-I grade driving wheel, a II grade connecting flange, a J1-I grade driven wheel and a J1-I grade driving wheel; the III-grade transmission speed reducing unit mainly comprises: a III-grade connecting flange, a J2-II-grade driving wheel, a J1-II-grade driven wheel, a J1-II-grade driving wheel, a driven wheel tensioning screw and a J2-II-grade driven wheel; the IV-stage transmission unit mainly comprises: the driving device comprises a level IV connecting flange, a level J1-III driven wheel, a level J2-III driven wheel, a level J1-III driving wheel and a level J1-III driving wheel; the wrist joint and the front end rotary joint mainly comprise: j3 wrist joint flange, J2-III driven wheel tensioning piece, J3 rotary joint driven wheel, J3 rotary bearing fixing flange, tail end output flange, J3 wrist joint, J2-IV driven wheel, J1 rotary flange, J3 wrist connecting flange, J3 rotary joint driving wheel, J3 joint reducer, J2 wrist pitching flange, J3 joint driving motor and J2-IV driving wheel.

The front end rotary joint of the J3 is decelerated by a speed reducer through a motor and then is decelerated through a first-stage rope pulley, and is output to the front end rotary flange, and the front end rotary joint is matched with the joints J1 and J2 to realize the motion with 3 degrees of freedom. The wrist joint is connected with the arm through a wrist rotary flange and a bearing to realize coaxial rotation. Meanwhile, the IV-level driving rope wheel and the IV driven rope wheel are vertically arranged, the IV-level driving rope wheel and the arm coaxially rotate to drive the IV driven rope wheel to rotate, and the IV driven rope wheel is connected with the wrist joint, so that the conversion of the power direction is realized. Each stage of transmission element is fixed in each stage of aluminum hollowed-out flange, so that the difficulty of assembly and maintenance is effectively reduced. The aluminum flanges of each stage are connected through screws to form the body structure of the arm. The tensioning mechanism is designed on the aluminum alloy rope pulley to preload the tensioning force, so that the elastic deformation of the steel wire rope is further reduced, and the movement precision of the robot is increased. Meanwhile, a gear reducer is not adopted in the whole structure, so that unnecessary return stroke difference caused by a multi-stage reducer is avoided, and the assembly difficulty is further reduced. In addition, the last stage of transmission rope wheel is directly and rigidly connected with the output shaft, so that a loaded transmission mechanism is effectively avoided, the weight of the robot is reduced, the friction loss caused by transmission is reduced, and the transmission efficiency of the robot is improved.

Fig. 1 to 15 show a three-degree-of-freedom sheave drive joint according to another embodiment of the present application. The three-degree-of-freedom rope wheel driving joint comprises: the elbow joint 1 is connected with the I-stage connecting flange 2 through screws, so that the whole front section rotates along with the rotation of the elbow joint; the J2 wrist pitching driving motor 3 and the J1 wrist revolving driving motor 36 are arranged on the I-grade connecting flange 2 and respectively drive the J2-I-grade driving wheel 6 and the J1-I-grade driving wheel 26 to rotate so as to realize the output of power; meanwhile, the J2-I grade driving wheel 6 and the J1-I grade driving wheel 26 form transmission with the J2-I grade driven wheel 4 and the J1-I grade driven wheel 25 through a steel wire rope with the diameter of 0.6mm and generate a speed reduction ratio of 10: 3, the steel wire rope is fixed at the end of the driving wheel through a driving wheel steel wire rope fixing piece 5, and the tensioning of the rope end is realized at the end of the driven wheel through a driven wheel tensioning screw 23; meanwhile, the stage I connecting flange 2 and the stage II connecting flange 24 are fixed by screws, and bearings are mounted at each output wheel end, so that a stage I transmission mechanism integrating transmission and speed reduction is formed (details are shown in fig. 4 and 14).

The II-stage transmission mechanism is similar to the I-stage transmission mechanism, and the J2-II-stage driving wheel 8 and the J1-II-stage driving wheel 22 are respectively connected with the J2-I-stage driven wheel 4 and the J1-I-stage driven wheel 25 through set screws at the wheel ends to form coaxial and same-speed rotation; meanwhile, the J2-II level driving wheel 8 and the J1-II level driving wheel 22 respectively form transmission with the J1-II level driven wheel 21 and the J2-II level driven wheel 35 through 0.8mm steel wire ropes and generate a speed reduction ratio of 4: 1, the steel wire ropes are fixed at the driving wheel end through a driving wheel steel wire rope fixing piece 5, and the tensioning of the rope end is realized at the driven wheel end through a driven wheel tensioning screw 23; meanwhile, the stage III connecting flange 7 and the stage IV connecting flange 7 are fixed by screws, and the top end of the connecting flange of each stage is provided with a coaxial straight port to ensure the coaxiality of transmission (details are shown in fig. 5 and 13).

The III-stage transmission mechanism is similar to the II-stage transmission mechanism, and only the driven wheels are changed from a radial distribution type to an axial distribution type; the J2-III driving wheel 34 and the J1-III driving wheel 20 are respectively connected with the J1-II driven wheel 21 and the J2-II driven wheel 35 through set screws at the wheel ends to form coaxial and same-speed rotation; meanwhile, the J2-III driving wheel 34 and the J1-III driving wheel 20 respectively form transmission with the J1-III driven wheel 10 and the J2-III driven wheel 11 through 1.2mm steel wire ropes and generate a reduction ratio of 4: 1, the steel wire ropes are also fixed at the driving wheel end through a driving wheel steel wire rope fixing piece 5, and the tensioning of the rope end is realized at the driven wheel end through a driven wheel tensioning screw 23 (details are shown in figures 6 and 12).

The IV-level transmission mechanism is different from the previous mode, mainly the J2-IV-level driven wheel 18 and the J2-IV-level driving wheel 33 are arranged at a right angle, and a steel wire rope is wound in an upper layer and a lower layer in a winding manner, so that the power transmission direction is changed; the J2-IV stage driven wheel 18 is connected with the J3 wrist joint 17 through screws, so that the pitching motion of the wrist joint is realized; the J1-III driven wheel 10 is connected with the J1 rotary flange 19 through screws, so that the same-speed rotation is realized; the J2-IV grade transmission steel wire rope realizes push-pull type tensioning adjustment through a tensioning piece 13 in a J2-IV grade driven wheel 18; the J1 rotary flange 19 is connected with the IV-level connecting flange 9 through a bearing to ensure coaxial rotation (details are shown in fig. 7 and 11).

Fig. 10 is an exploded view of a wrist in a robot arm according to an embodiment of the present invention, a rotary joint at a front end of the wrist in the robot arm is different from a previous layered power transmission manner, and since the rotary joint is only used for realizing the rotation of the end flange 16, there is no high requirement for absolute accuracy and return difference, and therefore, a first-stage speed reducer is added to realize the power transmission of a non-full sheave type. The J3 joint driving motor 32 is fixed on the J3 wrist joint 17, and transmits power to the J3 rotary joint driving wheel 29 after being decelerated by the J3 joint decelerator 30; the J3 rotary joint driving wheel 29 and the J3 rotary joint driven wheel 14 form transmission through a 0.8mm steel wire rope and generate a reduction ratio of 2: 1; the steel wire rope is fixed on the J3 rotary joint driving wheel 29 through a screw, and is tensioned at the wheel end of the J3 rotary joint driving wheel 29 through a screw; the top end of the J3 rotary joint driven wheel 14 is connected with the tail end output flange 16 through screws to realize the same-speed rotation, and a bearing is arranged in the middle to reduce the friction loss of transmission (the details are shown in figure 8).

According to the application, by means of the design of the speed reduction and driving system of the whole rope wheel, flexible transmission is realized, the precision of the robot is improved, and the return stroke difference is avoided, so that accurate pose and moment feedback can be realized more easily; the layered assembly structure and the arrangement of the symmetrical rope wheels effectively reduce the assembly difficulty and inhibit the mechanical vibration; the motor is arranged at the head end of the joint in a rope wheel driving mode, power is transmitted to the tail end of the joint through rope wheels at all levels, the requirement of transmission machinery on space is reduced through the flexibility of the steel wire rope, and the requirement of assembly precision is reduced.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

The above-described embodiments of the present application do not limit the scope of the present application. Any other corresponding changes and modifications made according to the technical idea of the present application should be included in the protection scope of the claims of the present application.

Claims

1. The utility model provides a three degree of freedom rope sheave drive joint which characterized in that is applied to in the arm, includes: the elbow joint, the I-stage transmission mechanism, the II-stage transmission mechanism, the III-stage transmission mechanism and the IV-stage transmission mechanism;

2. The three degree of freedom sheave drive joint of claim 1, characterized in that the elbow joint is connected with the class I connecting flange by screws.

3. The three-degree-of-freedom rope wheel driving joint as claimed in claim 1, wherein the J2-I stage driving wheel and the J1-I stage driving wheel are respectively in transmission with the J2-I stage driven wheel and the J1-I stage driven wheel through 0.6mm steel wire ropes and generate a reduction ratio of 10: 3.

4. The three-degree-of-freedom rope wheel driving joint as claimed in claim 3, wherein the J2-II driving wheel and the J1-II driving wheel form transmission with the J1-II driven wheel and the J2-II driven wheel respectively through a 0.8mm steel wire rope and generate a reduction ratio of 4: 1.

5. The three-degree-of-freedom rope wheel drive joint as claimed in claim 4, wherein the J2-III driving wheel and the J1-III driving wheel are respectively in transmission with the J1-III driven wheel and the J2-III driven wheel through 1.2mm steel wire ropes and generate a reduction ratio of 4: 1.

6. The three-degree-of-freedom rope pulley drive joint according to any one of claims 1 to 5, wherein the steel wire rope is fixed at one end of the driving wheel through a steel wire rope fixing piece of the driving wheel, and the tensioning of the rope end is realized at one end of the driven wheel through a tensioning screw of the driven wheel.

7. The three-degree-of-freedom rope wheel drive joint as recited in claim 1, wherein the J1-III driven wheel and the J2-III driven wheel in the III-level transmission mechanism are axially arranged.

8. A mechanical arm is characterized by comprising the three-degree-of-freedom rope wheel driving joint, a wrist joint connected with the three-degree-of-freedom rope wheel driving joint and a front end rotary joint, wherein the three-degree-of-freedom rope wheel driving joint is any one of 1 to 7.

9. The mechanical arm as claimed in claim 8, wherein the mechanical arm comprises an aluminum hollow flange, and the three-degree-of-freedom rope wheel drive joint is arranged at a proper position of the aluminum hollow flange.

10. A robotic arm as claimed in claim 8, in which the wrist and nose revolute joints comprise: j3 wrist joint flange, J2-III driven wheel tensioning piece, J3 rotary joint driven wheel, J3 rotary bearing fixing flange, tail end output flange, J3 wrist joint, J2-IV driven wheel, J1 rotary flange, J3 wrist connecting flange, J3 rotary joint driving wheel, J3 joint reducer, J2 wrist pitching flange, J3 joint driving motor and J2-IV driving wheel;