CN113334423A

CN113334423A - Long-arm unfolding mechanical arm joint in large-magnetic-field high-vacuum strong-radiation environment

Info

Publication number: CN113334423A
Application number: CN202110631225.7A
Authority: CN
Inventors: 黄超; 李鹏远; 王才旺; 罗蓉蓉; 陈辉; 邓华林; 闫腾飞
Original assignee: Southwestern Institute of Physics
Current assignee: Southwestern Institute of Physics
Priority date: 2021-06-07
Filing date: 2021-06-07
Publication date: 2021-09-03
Anticipated expiration: 2041-06-07
Also published as: CN113334423B

Abstract

The invention belongs to the fusion reactor operation and maintenance technology, and particularly relates to a long-arm mechanical arm joint in a large-magnetic-field high-vacuum strong-radiation environment, which comprises a joint arm driven part connected with a shaft connecting plate through a rotating shaft b and a joint arm driving part connected with the shaft connecting plate through a rotating shaft a; the driving part comprises a totally-enclosed cavity, a semi-enclosed cavity, a driver, a driving shaft, a torque sensor and a driving transmission system, wherein the driver, the driving shaft, the torque sensor and the driving transmission system are arranged in the semi-enclosed cavity; the driving transmission system is connected with the shaft connecting plate through a rotating shaft a 8; the driving is moved out of the position of the rotating shaft through the effective transmission mechanism, the driver can obtain larger space, the output torque is improved, more space obtained by the driver can be used for improving the power and increasing the shielding, and the mechanical arm is more resistant to irradiation.

Description

Long-arm unfolding mechanical arm joint in large-magnetic-field high-vacuum strong-radiation environment

Technical Field

The invention belongs to the fusion reactor operation and maintenance technology, and particularly relates to a mechanical arm long arm unfolding mechanical arm joint for maintenance in a cavity.

Background

The operation environment of fusion experimental apparatus and fusion reactor teleoperation robot is very abominable, can produce extremely strong gamma radiation after the shut down, has radioactive dust and gas in the heap, simultaneously in order to keep the efficiency of maintenance and operation, still keep the environment of strong magnetic field and high vacuum after the shut down, the arm that gets into intracavity maintenance just must be in the challenge of the abominable environment such as limited space internal face to strong magnetic field, high vacuum, strong radiation, pollutant are infected with. The existing mechanical arms are all long-arm unfolding mechanical arms, and joints of the mechanical arms are divided into three types due to limited space:

the first is a closed joint with the driver directly at the joint rotating shaft, the driver and the pipeline circuit are completely closed, and the number of the rotating shafts at the joint is 1. The mechanical arm with large load, such as the mechanical arm applied to the JET European combined super-ring, only has the degree of freedom of a horizontal plane, the driver is directly arranged at the joint, the driving power is limited by the size of the joint, the mechanical arm is generally only used for the horizontal motion with small moment, and the motion range of the joint is +/-90 degrees.

The second is an open joint with the actuator outside the joint, and a link mechanism is used to transmit the power in the arm to the joint, but this link mechanism is exposed to the outside, and the number of shafts at the joint is 1. If the mechanical arm is applied to a TFTR U.S. Tokamak fusion test device, the power can not be limited by joint space, but the structure is easy to retain radiation pollutants and is more inconvenient for surface cleaning.

The third is an open joint with the driver outside the joint, where the axis of rotation is 2. The vertical rotation adopts a four-bar mechanism, the horizontal rotation adopts a pulley wire pulling mechanism, the motion range of the AIA mechanical arm joint applied to the European Tore Supra device in the up-down direction is +/-45 degrees, the motion range is +/-90 degrees, the angle range is limited, the internal space of the barrel-shaped connecting bar is very easy to retain radiation pollutants, and the cleaning is not easy.

Open joints are prone to harboring radioactive materials; the driver is directly limited by space at the joint, and the torque is difficult to increase; although the closed joint is not easy to retain radiation pollutants, the rotation range of one rotating shaft is difficult to exceed +/-90 degrees.

Disclosure of Invention

The invention aims to provide a long-arm mechanical arm joint in a large-magnetic-field high-vacuum strong-radiation environment, which can enlarge the joint motion range and improve the power.

The technical scheme of the invention is as follows:

a long-arm mechanical arm joint in a large-magnetic-field high-vacuum strong-radiation environment comprises a joint arm driven part connected with a shaft connecting plate through a rotating shaft b and a joint arm driving part connected with the shaft connecting plate through a rotating shaft a;

the active part comprises a totally-enclosed cavity, a semi-enclosed cavity, a driver, a driving shaft, a torque sensor and a driving transmission system, wherein the driver, the driving shaft, the torque sensor and the driving transmission system are arranged in the semi-enclosed cavity; the driving transmission system is connected with the shaft connecting plate through a rotating shaft a 8;

comprises a rotating shaft connecting force-bearing part which connects the driving part of the driven part of the articulated arm.

The driving transmission system comprises a driving shaft connected with the driving shaft, a driving shaft disc connected with the driving shaft, a lower sliding rod and a lower sliding rod shaft which are connected with the rotating shaft a8 and are installed inside the semi-closed cavity, and an upper sliding rod shaft which are connected with the rotating shaft a8 and are oppositely arranged with the lower sliding rod and the lower sliding rod shaft.

The rotating shaft a is divided into two parts which are respectively connected with the upper and lower sliding rod structures.

The vertical rotation of the driving shaft is changed into horizontal rotation of a rotating shaft a through an upper sliding rod, an upper sliding rod shaft, a lower sliding rod and a lower sliding rod shaft, the rotating shaft a is fixedly connected with the rotating shaft b through a shaft connecting plate, and the rotating shaft a drives a shaft connecting plate to rotate.

The rotating shaft connecting force-bearing part is two external gear wheels, one of which is arranged at the end part of the semi-closed cavity, the other is arranged at the end part of the driven part of the joint arm, and the two are meshed.

The driving transmission system can also be a transmission mechanism consisting of a pair of gears, two gear shafts are vertical to each other, the main gear is arranged on the driving shaft, and the auxiliary gear is arranged on the rotating shaft a.

The gear is a bevel gear, a spiral bevel gear or a straight bevel gear.

The driving transmission system comprises a main transmission shaft, two internal main gears and an internal gear at the end part are arranged on the main transmission shaft; the fully-closed cavity and the semi-closed cavity of the driving part are designed into a driving mechanical arm, a vertical inner gear and a vertical gear at the inner end part are arranged on the inner side wall of the driving mechanical arm, and an external main gear is arranged on the outer side wall of the driving mechanical arm; the driven part is a driven mechanical arm, the rotating shaft b is a rotating shaft b, the rotating shaft a is a rotating shaft a, and the shaft connecting plate is a connecting plate; the rotating shaft connection stressed part comprises an external main gear and an internal gear at the end part; the vertical internal gear is meshed with the two internal main gears at the meshing position of the two internal gears; the end internal gear and the inner end vertical gear are meshed at the meshing position of the end internal gear.

The connecting shaft plate is installed through a rotating shaft a, and an angle sensor or an angular velocity sensor is arranged on the rotating shaft a.

The rotating shaft is connected with the stress part and is a tension belt, and two ends of the rotating shaft are fixedly connected to the end parts of the driving part and the driven part respectively.

The driven part and the driving part of the joint arm are respectively provided with joint cylindrical surfaces at the ends, and the pipeline assemblies in the joint arm are attached to the joint cylindrical surfaces and staggered up and down.

The semi-closed cavity is provided with a pipeline collecting pipe inlet and a pipeline collecting pipe outlet, the pipeline collecting pipe in the joint arm is led out from the fully-closed cavity and is hermetically connected with the fully-closed cavity, penetrates through the semi-closed cavity, is fixedly connected with the semi-closed cavity at the pipeline collecting pipe inlet and outlet, then penetrates out of the pipeline collecting pipe inlet and outlet, and is vertically and crossly connected to a driven part of the mechanical arm;

the pipelines and the lines between the totally-enclosed cavity and the semi-enclosed cavity are hermetically connected;

the gas inlet and outlet of the semi-closed cavity are positioned at the gap between the rotating shaft a and the semi-closed cavity.

The invention has the following remarkable effects:

1. the invention provides a brand-new semi-closed structure joint, wherein arms except the joint are totally closed, a joint rotating part is semi-closed, the semi-closed part has low sealing requirement, and the entrance or the outflow of radioactive substances is reduced under the condition of ensuring the motion range.

2. Due to the semi-closed and compact design of the transmission mechanism joint, the surface is smooth and regular, the protrusion and the depression are few, the retention of radioactive pollutants can be reduced, and the surface pollutants at the later stage of the joint are easy to clean and treat;

3. under the condition of narrow space or small section, the joint moves the drive out of the position of the rotating shaft through an effective transmission mechanism, the driver can obtain larger space, the output torque is improved, more space obtained by the driver can be used for improving the power and increasing the shielding, so that the mechanical arm is more resistant to irradiation;

4. the joint adopts a double-shaft design to ensure that the rotation range theoretically reaches +/-180 degrees, the drive in the joint only needs to rotate +/-90 degrees, the design increases the moving range of the joint, and meanwhile, when the mechanical arm does not work, the joint can be compactly folded;

5. meanwhile, by means of the joint structure, the length of an internal pipeline can be kept unchanged in the follow-up process, only bending deformation occurs, the corrugated pipe is used opportunistically, the tightness of pipeline connection between two arms is guaranteed, and meanwhile, the pipeline is always attached to the surfaces of two cylinders in the motion process, so that the pipeline has hiding performance.

The controller and the driving device are positioned in the totally-enclosed cavity, the driver such as a hydraulic rotary drive is positioned in the semi-enclosed cavity, and a pipeline and a circuit between the controller and the driver are connected through effective sealing. The gas within the semi-sealed chamber leaks away from the axis of rotation a8, where the gap is small, providing effective movement and reducing the influx and efflux of radioactive materials. Considering that the movable part is difficult to seal, and the hydraulic drive has sealing performance, the hydraulic drive is arranged in the semi-closed cavity, so that all key parts are sealed, and effective movement of the movable part can be realized. Meanwhile, when the fully-enclosed cavity is installed and assembled, all the components in the fully-enclosed cavity can be selected from conventional non-vacuum components and convection heat dissipation devices.

Because the outer surfaces of the full-sealed cavity and the semi-sealed cavity are smooth and regular, the whole cross section is square, and the joint connection part is less in protrusion and depression due to the complete built-in transmission mechanism, the hidden space of radioactive substances is effectively reduced, and the whole smooth appearance is convenient for cleaning radioactive pollutants.

By designing a vertical transmission mechanism, namely adopting a gear transmission mechanism and a rotating shaft deflector rod mechanism, hydraulic drive is moved into the arm from the rotating shaft position, and the driving rotating shaft is parallel to the axis of the arm, the arrangement can effectively utilize the space in the arm under the condition that the section of the mechanical arm is limited, the power of the driver is in direct proportion to the volume, so that the torque of the driver can be effectively improved, and the large torque is very important for the long-arm mechanical arm.

The joint arm is divided into a driving part and a driven part which are connected through a gear or a stretching belt, for example, an external meshing gear A is meshed with an external meshing gear B, and a rotating shaft a is fixedly connected with a rotating shaft B through a shaft connecting plate. When the driving shaft rotates +/-90 degrees, the shaft connecting plate also rotates +/-90 degrees, and due to the meshing effect of the external meshing gear, the motion range of the driven part of the joint arm is enlarged to 2 times and rotates +/-180 degrees. Therefore, the driving shaft can rotate +/-180 degrees only by rotating +/-90 degrees, the motion range is effectively improved, and the folding of the mechanical arm is facilitated.

The meshing positions of the joints are tangent, the gathering pipelines are attached to the cylindrical surfaces of the joints, the length of the central line of the gathering pipelines is kept unchanged in the whole motion range, the gathering pipelines are attached to the two cylindrical surfaces of the joints all the time, only bending changes occur, the gathering pipelines and the gathering pipelines in the two paths are staggered up and down, and interference does not occur. The manifold may contain coolant lines for cooling, hydraulic lines for power, lines for control signals, sensor signals and power. For the pipeline with the length unchanged and only bending, a corrugated pipe can be used, and the pipeline can be sealed. The joint cylindrical arm is attached all the time in the whole movement process, and does not protrude, so that the pipeline is hidden in the section of the arm.

Drawings

FIG. 1 is a schematic view of a long-arm extended mechanical arm joint in a large-magnetic-field high-vacuum strong-radiation environment;

FIG. 2 is a schematic view of a transmission system according to embodiment 1;

FIG. 3 is a schematic view of two external gears in embodiment 1;

FIG. 4 is a schematic view of a manifold;

FIG. 5 is a schematic view of the structure of a drive transmission system 7 according to embodiment 3;

FIG. 6 is a schematic drawing of the tension belt of example 4;

in the figure: 1. a totally enclosed cavity; 2. a driver; 3. a semi-enclosed cavity; 4. a drive shaft; 5. a torque sensor; 6. an inlet and an outlet of the pipeline collecting pipe; 7. a transmission system between the driving shaft and the rotating shaft a; 8. a rotating shaft a; 9. the rotating shaft is connected with a stressed part; 10. an articular cylindrical surface; 11. a pipeline manifold; 12. a rotating shaft b; 13. a driven portion of the articulated arm; 14. a shaft connecting plate;

9-1, two external gear wheels;

7-1 of a driving shaft 7-2 of a driving shaft disc 7-3 of an upper sliding rod 7-4 of a lower sliding rod 7-5 of an upper sliding rod shaft 7-6 of a lower sliding rod shaft;

7-21 parts of main transmission shaft 7-22 parts of two internal main gears 7-23 parts of vertical internal gear 7-24 parts of external main gear 7-25 parts of external gear meshing part 7-26 parts of rotating shaft a; 7-27. connecting shaft plate; 7-28. rotating shaft b; 7-29, a driven mechanical arm; 7-30, the meshing position of the two internal gears 7-31, the internal gear at the end part 7-32, the meshing position of the internal gear at the end part 7-33, the vertical gear at the inner end part 7-34, the position of a sensor 7-35, the meshing position of the external gears of the two arms 7-36 and a driving mechanical arm.

9-2, stretching the tension belt.

Detailed Description

The invention is further illustrated by the accompanying drawings and the detailed description.

Example 1

As shown in fig. 1, the robot arm joint includes a joint arm driven part 13 connected to a shaft connection plate 14 through a rotation shaft b12, and a joint arm driving part connected to the shaft connection plate 14 through a rotation shaft a 8;

the active part comprises a totally enclosed cavity 1, a semi-enclosed cavity 3, and a driver 2, a driving shaft 4, a torsion sensor 5 and a driving transmission system 7 which are arranged in the semi-enclosed cavity 3. The drive transmission system 7 is connected with the shaft connecting plate 14 through a rotating shaft a 8;

the driving shaft 4 is positioned on the axis of the driving part, when the driver 2 drives the driving shaft 4 to rotate, the torque sensor 5 transmits rotation data, and the driving shaft 4 rotates to drive the end part to rotate with a driving transmission system 7 connected with the driving shaft;

the pipelines and the lines between the totally-enclosed cavity 1 and the semi-enclosed cavity 3 are hermetically connected;

a pipeline collecting pipe inlet and outlet 6 is processed in the semi-closed cavity 3, the pipeline collecting pipe 11 is led out from the fully-closed cavity 1 and is hermetically connected with the fully-closed cavity, penetrates through the semi-closed cavity 3, is fixedly connected with the semi-closed cavity 3 at the pipeline collecting pipe inlet and outlet 6, then penetrates out of the pipeline collecting pipe inlet and outlet 6, and is vertically and crossly connected to a driven part 13 of the mechanical arm;

the gas inlet and outlet of the semi-closed cavity 3 are positioned at the gap between the rotating shaft a8 and the semi-closed cavity 3;

the pipeline sets 11 connected with the driving part and the driven part are respectively attached to joint cylindrical surfaces 10 designed at the ends of the driving part and the driven part, and are staggered up and down without interference.

The pivot connection receiving member 9 connects the articulated arm driven part 13 and the driving part.

In the embodiment, the rotating shaft connection stress part 9 is selected as two external gear fitting A and B, namely two external gears 9-1;

the external meshing gear B is arranged at the end part of the semi-closed cavity 3; the external engagement gear a is mounted on the end of the articulated arm driven part 13, which are engaged.

When the driving shaft 4 rotates a certain angle, the shaft connecting plate 14 is fixedly connected with the driving transmission system 7 and correspondingly rotates, and due to the meshing effect of the external meshing gear, the driven part 13 of the articulated arm is influenced by the meshing of the shaft connecting plate 14 and the gear, and the movement range is enlarged by 2 times.

For example, when the driving shaft 4 rotates 90 °, the rotating shaft a8 is driven to rotate 90 °, the connecting plate 14 also rotates 90 °, the rotating shaft b12 rotates 90 ° relative to the connecting plate 14 due to the meshing action of the external meshing gears, the driven part 13 of the articulated arm is fixedly connected with the rotating shaft b12, so that the driven part 13 rotates 180 ° relative to the rotating shaft a8, and the movement angle is amplified by 2 times.

As shown in FIG. 2, in the design of the driving transmission system 7, it comprises a driving shaft 7-1 connected with the driving shaft 4, a driving shaft disk 7-2 connected with the driving shaft 7-1, a lower slide bar 7-4 and a lower slide bar shaft 7-6 connected with a rotating shaft a8 and installed inside the semi-enclosed chamber 3, and an upper slide bar 7-3 and an upper slide bar shaft 7-5 connected with a rotating shaft a8 and placed opposite to the lower slide bar 7-4 and the lower slide bar shaft 7-6;

it can be seen that the rotating shaft a8 is divided into two parts, which are respectively connected with the slide bar structures (corresponding slide bars and shafts) on the upper and lower sides;

the sliding rod rocker consists of a driving shaft 7-1, a driving shaft disc 7-2, an upper sliding rod 7-3, a lower sliding rod 7-4, an upper sliding rod shaft 7-5 and a lower sliding rod shaft 7-6, and the combination of the sliding rod shafts and the sliding rods can be 1 or 2 pairs.

The vertical rotation of the driving shaft 7-1 is changed into the horizontal rotation of a rotating shaft a8 through the upper sliding rod 7-3, the upper sliding rod shaft 7-5, the lower sliding rod 7-4 and the lower sliding rod shaft 7-6. The rotating shaft a8 and the rotating shaft b12 are fixedly connected through the shaft connecting plate 14, the rotating shaft a8 rotates to drive the shaft connecting plate 14 to rotate, the left arm and the right arm rotate under the action of the two middle external gears 9-1 (as shown in fig. 3, the rotating shaft connecting stress component 9 in the embodiment is selected to be meshed with the two external gears), the driven part of the joint arm rotates around the rotating shaft b, and the rotating range is increased by 1 time. The rocker arm structure of the sliding rod can move +/-90 degrees, the left arm and the right arm can move +/-180 degrees, and the surface contact between a hole and the rod is kept in the transmission process, so that the transmission of large torque is facilitated; meanwhile, the center position of the movable range is a load maximum position, that is, a 0 ° position, and the driver can provide the maximum torque. As shown in fig. 4, in the whole rotation process, the upper and lower pipeline collecting pipes 11 are always attached to the joint cylindrical surface 10, the total length is unchanged, and only bending change occurs, so that the pipeline sealing design is facilitated, and the pipeline is hidden in a rectangular section.

Example 2

The driving transmission system 7 can also be a transmission mechanism consisting of a pair of gears, the two gear shafts are perpendicular to each other, and the gears are a pair of meshed conical gears or spiral bevel gears or straight bevel gears.

The structure is relatively simple, the size of the transmitted angle can be adjusted according to the transmission ratio of the gear pair, but the transmitted torque is not large. The primary gear is mounted on the primary shaft 7-1 and the secondary gear is mounted on the rotating shaft a 8. The rest of the process was the same as in example 1

Example 3

In this embodiment, the drive transmission system 7 has the following structure in the articulated arm:

as shown in FIG. 5, a main transmission shaft 7-21 is installed in a driving mechanical arm 7-36 (which is equivalent to the cavity of the driving part), two internal main gears 7-22 and end internal gears 7-31 are installed on the main transmission shaft 7-21, a vertical internal gear 7-23 and an internal vertical gear 7-33 are installed on the inner side wall of the driving mechanical arm 7-36, an external main gear 7-24 (which is equivalent to the two external meshing gears 9-1 of embodiment 1) and a coupling plate 7-27 (which is equivalent to the shaft connecting plate 14 in the embodiment) are installed on the outer side wall of the driving mechanical arm 7-36, the connecting shaft plates 7-27 are mounted through rotating shafts a7-26 (corresponding to the rotating shaft a8), and the rotating shafts a7-26 are provided with sensors 7-34 which are angle sensors or angular velocity sensors.

The vertical internal gear 7-23 and the two internal main gears 7-22 are meshed at the meshing part 7-30 of the two internal gears;

the end internal gear 7-31 and the inner end vertical gear 7-33 are meshed at the end internal gear meshing part 7-32;

a rotating shaft b7-28 (corresponding to a rotating shaft b12) is arranged inside the driven mechanical arm 7-29, and a connecting shaft plate 7-27 (corresponding to a shaft connecting plate 14 in the embodiment) positioned outside the driven mechanical arm 7-29 is connected through the rotating shaft b7-28, so that the driven driving mechanical arm is connected, and the gears of the two parts are meshed at the meshing part 7-35 of the external gears of the two arms;

this embodiment is designed to take multiple gear drives and increase the external gear mesh points when the torque requirements are somewhat larger and space is limited. The main drive shaft 7-21 transmits torque to the two inner main gears 7-22 and then to the outer main gear 7-24 via the two inner gears 7-23, the outer main gear 7-24 transmits torque to the rotation axis a7-26 via the outer gear mesh, the rotation axis a7-26 and the rotation axis b7-28 are fixedly connected via the coupling plate 7-27, and since the end of the driven arm 7-29 is engaged via the two arm outer gear mesh 7-35, the rotation of the coupling plate 7-27 will result in double rotation of the driven arm. In addition, the main transmission shaft 7-21 is engaged with the inner end vertical gear 7-33 through the end internal gear 7-31, and transmits the torque to the rotation shaft a7-26 synchronously. The multiple gears are synchronously meshed, so that a passage for transmitting torque is increased, and the torque acting on a single gear is reduced.

Example 4

The rotation shaft connecting force-bearing part 9 may also be in a gear meshing manner, such as the external meshing gear B and the external meshing gear a in embodiment 1, or in a tensioning manner of a tension belt in this embodiment, as shown in fig. 6, two ends of one tension belt are respectively and fixedly connected to the driving part and the driven part, and are attached to the cylindrical surface of the arm, so as to realize the same meshing effect, and this structure can bear a larger interaction force, and the tension belt 9-2 needs to have a bending deformation capability.

Claims

1. The utility model provides a long arm exhibition arm joint under big magnetic field high vacuum strong radiation environment, includes the driven part of articulated arm (13) of being connected through pivot b (12) and hub connection board (14) to and the initiative part of articulated arm of being connected through pivot a (8) and hub connection board (14), its characterized in that:

the active part comprises a totally-enclosed cavity (1), a semi-enclosed cavity (3), a driver (2), a driving shaft (4), a torsion sensor (5) and a driving transmission system (7), wherein the driver (2), the driving shaft (4), the torsion sensor and the driving transmission system are arranged in the semi-enclosed cavity (3); wherein the driving transmission system (7) is connected with the shaft connecting plate (14) through a rotating shaft a (8);

comprises a rotating shaft connection stress part (9) which connects a driven part (13) and a driving part of the joint arm.

2. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the driving transmission system (7) comprises a driving shaft (7-1) connected with the driving shaft (4), a driving shaft disc (7-2) connected with the driving shaft (7-1), a lower sliding rod (7-4) and a lower sliding rod shaft (7-6) which are connected with a rotating shaft a (8) and installed inside the semi-closed cavity (3), and an upper sliding rod (7-3) and an upper sliding rod shaft (7-5) which are connected with the rotating shaft a (8) and are oppositely arranged with the lower sliding rod (7-4) and the lower sliding rod shaft (7-6).

3. The long-arm span mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment as claimed in claim 2, wherein: the rotating shaft a (8) is divided into two parts which are respectively connected with the upper and lower sliding rod structures.

4. The long-arm span mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 3, wherein: the vertical rotation of the driving shaft (7-1) is changed into horizontal rotation of a rotating shaft a (8) through an upper sliding rod (7-3), an upper sliding rod shaft (7-5), a lower sliding rod (7-4) and a lower sliding rod shaft (7-6), the rotating shaft a (8) and a rotating shaft b (12) are fixedly connected through a shaft connecting plate (14), and the rotation of the rotating shaft a (8) drives the shaft connecting plate (14) to rotate.

5. The long-arm span mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 3, wherein: the rotating shaft connecting force-bearing part (9) is two external gear (9-1), one of which is arranged at the end part of the semi-closed cavity (3), and the other is arranged at the end part of the joint arm driven part (13), and the two are meshed.

6. The long-arm span mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 3, wherein: the driving transmission system (7) can also be a transmission mechanism consisting of a pair of gears, two gear shafts are vertical to each other, a main gear is arranged on a driving shaft (7-1), and a pinion is arranged on a rotating shaft a (8).

7. The long-arm span mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 6, wherein: the gear is a bevel gear, a spiral bevel gear or a straight bevel gear.

8. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the driving transmission system (7) comprises a main transmission shaft (7-21) connected with the driving shaft (4), and two internal main gears (7-22) and end internal gears (7-31) are arranged on the main transmission shaft; the fully-closed cavity (1) and the semi-closed cavity (3) of the driving part are designed into driving mechanical arms (7-36), vertical internal gears (7-23) and vertical gears (7-33) at the inner end parts are installed on the inner side walls of the driving mechanical arms (7-36), and external main gears (7-24) are installed on the outer side walls of the driving mechanical arms (7-36); the driven part (13) is a driven mechanical arm (7-29), the rotating shaft a (8) is a rotating shaft a (7-26), the rotating shaft b (12) is a rotating shaft b (7-28), and the shaft connecting plate (14) is a connecting shaft plate (7-27); the rotating shaft connection stress part (9) comprises an external main gear (7-24) and an end internal gear (7-31); the vertical internal gears (7-23) and the two internal main gears (7-22) are meshed at the meshing part (7-30) of the two internal gears; the end internal gear (7-31) and the inner end vertical gear (7-33) are meshed at the meshing part (7-32) of the end internal gear.

9. The long-arm span mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 8, wherein: the connecting shaft plates (7-27) are installed through rotating shafts a (7-26), and angle sensors or angular speed sensors are arranged on the rotating shafts a (7-26).

10. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the rotating shaft connecting stress part (9) is a tension tensioning belt (9-2), and two ends of the rotating shaft connecting stress part are fixedly connected to the end parts of the driving part and the driven part respectively.

11. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the joint arm driven part (13) and the driving part are respectively provided with joint cylindrical surfaces (10) at the ends, and the pipeline assemblies (11) in the joint arm are attached to the joint cylindrical surfaces (10) and staggered up and down.

12. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the semi-closed cavity (3) is provided with a pipeline collecting pipe inlet and outlet (6), the pipeline collecting pipe (11) in the joint arm is led out from the fully-closed cavity (1) and hermetically connected with the fully-closed cavity, penetrates through the semi-closed cavity (3), is fixedly connected with the semi-closed cavity (3) at the pipeline collecting pipe inlet and outlet (6), then penetrates out of the pipeline collecting pipe inlet and outlet (6), and is vertically and crossly connected with a driven part (13) of the mechanical arm.

13. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the pipelines and the lines between the totally-enclosed cavity (1) and the semi-enclosed cavity (3) are hermetically connected.

14. The long-arm mechanical arm joint in the large-magnetic-field high-vacuum strong-radiation environment according to claim 1, wherein: the gas inlet and outlet of the semi-closed cavity (3) are positioned at the gap between the rotating shaft a (8) and the semi-closed cavity (3).