CN112128491A - Ring groove sealed rotary joint - Google Patents

Abstract

The application discloses a ring groove sealing type rotary joint which comprises a mandrel, a rotating body and a fixing body; the rotating body comprises an upper ring groove and an upper connecting pipe, the upper ring groove is of an annular groove body structure with a downward opening and forms a first circulation cavity in the upper ring groove, and one end of the upper connecting pipe is connected to the outer side of the upper ring groove; the fixing body comprises a lower ring groove and a lower connecting pipe, the lower ring groove is of an annular groove body structure with an upward opening and forms a second circulation cavity inside, and one end of the lower connecting pipe is connected to the outer side of the lower ring groove; the lower end of the upper ring groove is hermetically connected with the upper end of the lower ring groove, the first circulation cavity is communicated with the second circulation cavity, and the upper ring groove and the lower ring groove can rotate relatively; the mandrel passes through the holes at the centers of the upper ring groove and the lower ring groove, the fixed body is fixedly connected to the mandrel, and the rotating body is rotatably connected to the mandrel. The invention can improve the transmission flow of the rotary joint without increasing the height of the rotary joint, and the whole weight of the rotary joint is lighter, so the rotary joint is suitable for main body equipment which requires light weight and has limited height space.

Description

Ring groove sealed rotary joint

Technical Field

The application belongs to the technical field of rotary joints, and particularly relates to a ring groove sealing type rotary joint.

Background

Rotary joints are commonly used in heavy machinery such as metallurgical equipment to convey fluid media, so that rigid pipes fixed to the main equipment can rotate relatively and bear certain fluid pressure. The rotary joint has the characteristics of large conveying flow and high bearing pressure, and is suitable for high-temperature and dusty working environments.

A rotary joint in heavy machinery such as metallurgical equipment is generally of a rotary body spindle type and is mainly configured as shown in fig. 1. A first bearing 100 and a second bearing 107 are arranged between the rotor 102 and the mandrel 109, so that the rotor and the mandrel can rotate relatively; two groups of sealing rings 108 are arranged between the rotating body 102 and the mandrel 109 to ensure sealing; the end cover 103 is closed on the shaft shoulder of the mandrel 109, and the middle of the end cover is provided with a gasket group 104 for adjusting the gap of the second bearing 107; plug 105 is a passage process plug for mandrel 109; the first adapter 101 and the second adapter 106 are connected to the rotor 102 and the spindle 109, respectively. The first joint 101 and the second joint 106 are respectively connected with a rigid pipeline on the main body equipment; mandrel 109 is fixed to the part of the apparatus where the rigid conduit connected to joint 106 is located; when the two parts of the equipment rotate mutually, the rigid pipeline conveys fluid through the rotary joint, so that a hose can be prevented from being used at the movable connection part of the main equipment, and the operation is reliable.

However, the existing rotary joint has the following problems: the rotor 102 and the spindle 109 are made of a large amount of material, thus resulting in a heavy weight of the rotary joint; the rotary joint needs to be provided with mounting structures for the two groups of sealing rings 108, the second bearing 107 and the first bearing 100, so that the overall height is high; when the flow of the rotary joint is increased, the height of the rotary joint is increased, and the rotary joint is not suitable for main equipment which requires light weight and limited height space.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide a circular groove sealed rotary joint, which can improve the transmission flow of the rotary joint without increasing the height of the rotary joint, thereby saving the materials used for the components and making the whole rotary joint lighter in weight; therefore, the rotary joint can be applied to main body equipment which requires light weight and limited height space.

In order to solve the technical problem, the embodiment of the invention adopts the technical scheme that: a ring groove sealed rotary joint comprises a mandrel, a rotating body and a fixing body;

the rotating body comprises an upper ring groove and an upper connecting pipe, the upper ring groove is of an annular groove body structure with a downward opening and forms a first circulation cavity in the upper ring groove, and one end of the upper connecting pipe is connected to the outer side of the upper ring groove and communicated with the first circulation cavity;

the fixing body comprises a lower ring groove and a lower connecting pipe, the lower ring groove is of an annular groove body structure with an upward opening and a second circulation cavity is formed in the lower ring groove, and one end of the lower connecting pipe is connected to the outer side of the lower ring groove and communicated with the second circulation cavity;

the lower end of the upper ring groove is connected with the upper end of the lower ring groove in a sealing mode, the first circulation cavity is communicated with the second circulation cavity, and the upper ring groove and the lower ring groove can rotate relatively;

the dabber passes go up the annular with the hole at lower annular center, the rotor rotate connect in the dabber, the fixed body fixed connection in the dabber.

Further, the upper ring groove comprises an upper sealing plate, an upper inner ring body and an upper outer ring body which are both of annular structures;

the upper outer ring body is sleeved outside the upper inner ring body, the top of the upper inner ring body and the top of the upper outer ring body are both connected to the upper sealing plate, and the upper outer ring body, the upper inner ring body and the upper sealing plate enclose the first flow-through cavity; the end part of the upper connecting pipe is connected with the outer wall of the upper outer ring body;

the lower ring groove comprises a lower sealing plate, a lower inner ring body and a lower outer ring body which are both of annular structures;

the lower outer ring body is sleeved outside the lower inner ring body, the bottom of the lower inner ring body and the bottom of the lower outer ring body are both connected to the lower sealing plate, and the lower outer ring body, the lower inner ring body and the lower sealing plate enclose the second flow-through cavity; the end part of the lower connecting pipe is connected with the outer wall of the lower outer ring body.

Further, the upper inner ring body is sleeved on the lower inner ring body, and the upper outer ring body is sleeved on the lower outer ring body.

Further, an upper sealing groove is formed in the part, matched with the lower inner ring body, of the upper inner ring body, and an inner sealing element is installed in the upper sealing groove, so that the upper inner ring body and the lower inner ring body are connected in a sealing mode through the inner sealing element;

and the part of the upper outer ring body, which is matched with the lower outer ring body, is provided with a lower sealing groove, and an outer sealing element is arranged in the lower sealing groove, so that the upper outer ring body and the lower outer ring body are connected in a sealing manner through the outer sealing element.

Further, a radial annular boss is arranged on the side wall of the upper inner ring body, and a self-lubricating bearing is arranged between the mandrel and the upper inner ring body;

the lower end face of the self-lubricating bearing is abutted against the top face of the lower inner ring body, and the upper end face of the self-lubricating bearing is abutted against the lower end face of the radial annular boss.

Further, the annular groove sealed type rotary joint also comprises an end cover and a support ring;

the upper end of the mandrel penetrates through the upper inner ring body and then is connected with the end cover;

the support ring is sleeved outside the mandrel and is positioned between the radial annular boss and the end cover.

Furthermore, a labyrinth seal is arranged between the upper ring groove and the end cover, and comprises an axial annular boss and an annular groove;

the annular groove is arranged on the lower surface of the end cover, the axial annular boss is arranged on the upper surface of the upper ring groove, and the axial annular boss is located in the annular groove.

Furthermore, a gasket set is arranged between the bottom of the end cover and the end face of the mandrel, and the gasket set comprises a plurality of stacked gaskets.

Furthermore, the annular groove sealed type rotary joint also comprises a base and a bottom plate;

the bottom end of the mandrel is connected to the bottom plate, the bottom plate is fixed to the base, and the lower surface of the lower sealing plate is abutted to the upper surface of the bottom plate.

Further, the annular groove sealing type rotary joint also comprises a lower joint and an upper joint;

the lower joint is connected with one end, far away from the lower annular, of the lower connecting pipe, and the upper joint is connected with one end, far away from the upper annular, of the upper connecting pipe.

Compared with the prior art, the invention has the following advantages:

the invention can improve the transmission flow of the rotary joint by increasing the widths of the groove bodies of the upper ring groove and the lower ring groove and the pipe diameters of the upper connecting pipe and the lower connecting pipe under the condition of not increasing the height of the rotary joint, thereby saving the materials used by the parts and ensuring that the whole weight of the rotary joint is lighter; the volume of the mandrel and the rotating body is obviously reduced, and the materials used by the mandrel and the rotating body are less, so that the rotary joint of the embodiment has lighter overall weight, and therefore, the rotary joint can be suitable for main equipment which requires light weight and has limited height space.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural view of a conventional rotary joint.

Fig. 2 is a top view of fig. 1.

Fig. 3 is a schematic view of a ring groove seal type rotary joint structure according to an embodiment of the present invention.

Fig. 4 is a top view of fig. 3.

Fig. 5 is an enlarged view of fig. 3 at a.

Fig. 6 is a schematic structural diagram of a fixing body according to an embodiment of the present invention.

Fig. 7 is a schematic structural diagram of a rotating body according to an embodiment of the present invention.

Description of reference numerals:

1, a mandrel;

2-a rotor; 21-upper ring groove; 211 — upper inner ring;

212 — upper outer ring body; 213-upper closing plate; 214-radial annular boss;

215-axial annular boss; 22-upper connecting pipe;

3-a stationary body; 31-lower ring groove; 311-lower inner ring body;

312 — lower outer ring body; 313-a lower seal plate; 32-lower connecting pipe;

4-lower joint; 5, upper joint; 6-inner seal;

7-outer seal; 8-self-lubricating bearing;

9-end cover; 91-an annular groove;

10-supporting ring; 11-shim set; 12-a base;

13 — a first flow-through chamber; 14 — a second flow-through chamber; 15-a base plate;

100 — a first bearing; 101 — a first joint; 102-a rotor;

103-end cap; 104-shim group; 105-plug;

106 — a second joint; 107 — second bearing; 108-a sealing ring;

109-mandrel.

Detailed Description

As shown in fig. 3 to 7, the ring groove sealing type rotary joint according to the embodiment of the present invention includes a mandrel 1, a rotating body 2, and a fixing body 3.

The rotating body 2 includes an upper ring groove 21 and an upper connecting pipe 22, the upper ring groove 21 is an annular groove body structure with a downward opening and forms a first circulation cavity 13 inside, and one end of the upper connecting pipe 22 is connected to the outer side of the upper ring groove 21 and communicated with the first circulation cavity 13.

The fixing body 3 includes a lower ring groove 31 and a lower connection pipe 32, the lower ring groove 31 is an annular groove structure with an upward opening and forms a second circulation chamber 14 inside, and one end of the lower connection pipe 32 is connected to the outer side of the lower ring groove 31 and is communicated with the second circulation chamber 14.

The lower end of the upper ring groove 21 is connected with the upper end of the lower ring groove 31 in a sealing mode, the first circulation cavity 13 is communicated with the second circulation cavity 14, and the upper ring groove 21 and the lower ring groove 31 can rotate relatively.

The core shaft 1 penetrates through the holes at the centers of the upper ring groove 21 and the lower ring groove 31, the rotating body 2 is rotatably connected to the core shaft 1, and the fixing body 3 is fixedly connected to the core shaft 1.

When the ring groove sealing type rotary joint of the embodiment is used, the rotary joint is installed on main equipment, the end parts of the upper connecting pipe 22 and the lower connecting pipe 32 are connected into two rigid pipelines which rotate mutually, and the first circulation cavity 13 and the second circulation cavity 14 are communicated to form a fluid conveying channel; the upper ring groove 21 and the lower ring groove 31 of the embodiment are in dynamic sealing connection, so that when the rotating body 2 and the fixed body 3 rotate relatively, the sealing performance of a conveying channel formed by the first circulating cavity 13 and the second circulating cavity 14 can be ensured, the fluid seepage of the conveying channel is avoided, and therefore when the two parts of the main body equipment rotate mutually, the rigid pipeline can convey fluid through the rotary joint.

The rotary joint of this embodiment can reduce the height of rotary joint through increasing the cell body width of upper ring groove 2 and lower ring groove 4 and the pipe diameter of upper connecting pipe 3 and lower connecting pipe 5 under the condition of equal fluid transmission capacity, consequently has also saved the used material of part for rotary joint whole weight is lighter.

Compared with the prior art, the size of the mandrel 1 and the rotor 2 is obviously reduced, and the materials used by the mandrel 1 and the rotor 2 are less, so that the whole weight of the rotary joint is lighter, and the rotary joint can be suitable for main equipment which requires light weight and is limited in height space.

As shown in fig. 3, 6 and 7, in the present embodiment, the upper ring groove 21 includes an upper closing plate 213, and an upper inner ring body 211 and an upper outer ring body 212, both of which are of a ring structure. The upper outer ring body 212 is sleeved outside the upper inner ring body 211, the top of the upper inner ring body 211 and the top of the upper outer ring body 212 are both connected to the upper sealing plate 213, and the upper outer ring body 212, the upper inner ring body 211 and the upper sealing plate 213 enclose a first flow-through cavity 13; the end of the upper connection pipe 22 is connected to the outer wall of the upper outer ring body 212.

The lower ring groove 31 includes a lower closing plate 313, and a lower inner ring body 311 and a lower outer ring body 312 both having a ring structure. The lower outer ring body 312 is sleeved outside the lower inner ring body 311, the bottom of the lower inner ring body 311 and the bottom of the lower outer ring body 312 are both connected to the lower sealing plate 313, and the lower outer ring body 312, the lower inner ring body 311 and the lower sealing plate 313 enclose a second flow-through cavity 14; the end of the lower connection pipe 32 is connected to the outer wall of the lower outer ring body 312.

As shown in fig. 6 and 7, the upper cover plate 213 and the lower cover plate 313 are both circular surfaces.

The end of the upper connection pipe 22 is fixed to the outer wall of the upper outer ring body 212, and the end of the lower connection pipe 32 is fixed to the outer wall of the lower outer ring body 312, so that the height of the rotary joint can be reduced, and the problem that the height of the rotary joint is high because the ends of the upper connection pipe 22 and the lower connection pipe 32 are fixed to the upper sealing plate 213 and the lower sealing plate 313, respectively, is avoided.

In this embodiment, the upper inner ring 211 is sleeved on the lower inner ring 311, and the upper outer ring 212 is sleeved on the lower outer ring 312.

Since the upper ring groove 21 and the lower ring groove 31 are connected by insertion, the upper ring groove 21 and the lower ring groove 31 can have an overlapping structure in the axial direction, and the joint length of the upper ring groove 21 and the lower ring groove 31 can be increased to further reduce the height of the rotary joint.

The sleeving manner of the embodiment can facilitate the sealing connection structure of the upper ring groove 21 and the lower ring groove 31, and meanwhile, the installation and fixation of the rotating body 2 are facilitated.

As shown in fig. 3, in this embodiment, an upper sealing groove is disposed at a position of the upper inner ring 211, which is matched with the lower inner ring 311, and an inner sealing element 6 is installed in the upper sealing groove, so that the upper inner ring 211 and the lower inner ring 311 are hermetically connected by the inner sealing element 6. The upper outer ring body 212 is provided with a lower sealing groove at a position matched with the lower outer ring body 312, and an outer sealing element 7 is installed in the lower sealing groove, so that the upper outer ring body 212 and the lower outer ring body 312 are connected in a sealing manner through the outer sealing element 7.

In this embodiment, the inner seal 6 and the outer seal 7 are located at the same height. Wherein the inner seal 6 and the outer seal 7 may also be located at similar heights.

The inner seal 6 and the outer seal 7 may be dynamic seal rubber seals.

The inner sealing piece 6 and the outer sealing piece 7 are positioned at the same height, so that the height of a sealing piece mounting structure is reduced, and the problem that the rotary joint is high due to the fact that the two sealing pieces are arranged at different heights in the prior art is solved.

With reference to fig. 3, in this embodiment, a radial annular boss 214 is disposed on a side wall of the upper inner ring 211, and a self-lubricating bearing 8 is disposed between the mandrel 1 and the upper inner ring 211; the lower end surface of the self-lubricating bearing 8 abuts against the top surface of the lower inner ring 311, and the upper end surface of the self-lubricating bearing 8 abuts against the lower end surface of the radial annular boss 214.

Self-lubricating bearing 8 sets up between the radial annular boss 23 of lower inner ring 41 and upper inner ring 21, makes upper inner ring 21 can support on lower inner ring 41 through self-lubricating bearing 8 to rotor 2 can rotate on stationary body 3 with less resistance under self-lubricating bearing 8's effect.

The end of the upper connecting pipe 22 is fixed on the outer wall of the upper outer ring body 212, so that the self-lubricating bearing 8 and the upper connecting pipe 22 of the embodiment are located at the same height, the height of the rotary joint can be further reduced, and the problem that the rotary joint is high due to the fact that the joint and the bearing in the prior art are arranged at different heights is avoided.

Referring to fig. 5, the rotary joint of the present embodiment further includes an end cap 9 and a support ring 10. Wherein, the upper end of the mandrel 1 is connected with the end cover 9 after passing through the upper inner ring body 211. The support ring 10 is sleeved outside the mandrel 1, and the support ring 10 is located between the radial annular boss 214 and the end cover 9.

It should be noted that, the support ring 10 is made of copper and has a circular ring structure, and the support ring 10 can avoid friction between the end cover 9 and the upper ring groove 21.

The upper end of the mandrel 1 of the embodiment is connected with the end cover 9 through a bolt, and the bolt penetrates through the end cover 9 and then is screwed into a threaded hole formed in the upper end of the mandrel 1.

The end cap 9 can fix the rotor 2 on the spindle 1, preventing the rotor 2 from being detached from the spindle 1. The support ring 10 reduces the resistance between the end cap 9 and the upper ring channel 21, thus ensuring that the rotor 2 can rotate on the stator 3.

Further, a labyrinth seal is provided between the upper ring groove 21 and the end cover 9, the labyrinth seal comprising an axial annular boss 215 and an annular groove 91. An annular groove 91 is provided in the lower surface of the end cap 9, an axial annular boss 215 is provided on the upper surface of the upper ring groove 21, and the axial annular boss 215 is located in the annular groove 91.

The labyrinth seal can ensure that a proper gap is reserved between the upper ring groove 21 and the end cover 9 when the upper ring groove 21 and the end cover 9 move relatively, so that the reliability of the rotary joint in operation is ensured. The labyrinth seal also prevents dust from entering the rotating clearance between the upper ring groove 21, the support ring 10 and the mandrel 9. When the rotary joint is in actual use, dry oil can be smeared at the labyrinth seal, and then a better protection effect can be realized.

With further reference to fig. 5, a shim pack 11 is provided between the bottom of the end cap 9 and the end face of the mandrel 1, and the shim pack 11 comprises a plurality of stacked shims. The user can adjust the installation gap between the support ring 10 and the radial annular boss 214 by adjusting the number of the spacers in the spacer set 11, and the size of the gap is not too large. Too large a gap will cause the upper ring groove 21 to move upwards, and too small a gap will cause the upper ring groove 21 to be unable to rotate.

The rotary joint of the present embodiment further includes a base 12 and a bottom plate 15; the bottom end of the mandrel 1 is connected to the bottom plate 15, the bottom plate 15 is fixed to the base 12, and the lower surface of the lower sealing plate 313 abuts against the upper surface of the bottom plate 15.

It should be noted that the base plate 15 and the base 12 are used to support the rotating member 1 and the fixing member 2, and the base 12 can fixedly mount the rotating joint.

As shown in fig. 3 and 4, the rotary joint of the present embodiment further includes a lower connector 4 and an upper connector 5. The lower joint 4 is connected to one end of the lower connection pipe 32 far from the lower ring groove 31, and the upper joint 5 is connected to one end of the upper connection pipe 22 far from the upper ring groove 21.

The swivel can be connected to the rigid tubing of the main unit by means of an upper joint 5 and a lower joint 4.

The above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiments according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. The utility model provides a ring groove sealed rotary joint which characterized in that: comprises a mandrel (1), a rotating body (2) and a fixed body (3);

the rotating body (2) comprises an upper ring groove (21) and an upper connecting pipe (22), the upper ring groove (21) is of an annular groove body structure with a downward opening and forms a first circulation cavity (13) inside, and one end of the upper connecting pipe (22) is connected to the outer side of the upper ring groove (21) and communicated with the first circulation cavity (13);

the fixing body (3) comprises a lower ring groove (31) and a lower connecting pipe (32), the lower ring groove (31) is of an annular groove body structure with an upward opening and forms a second circulation cavity (14) inside, and one end of the lower connecting pipe (32) is connected to the outer side of the lower ring groove (31) and communicated with the second circulation cavity (14);

the lower end of the upper ring groove (21) is connected with the upper end of the lower ring groove (31) in a sealing mode, the first circulation cavity (13) is communicated with the second circulation cavity (14), and the upper ring groove (21) and the lower ring groove (31) can rotate relatively;

dabber (1) pass go up annular (21) with the hole at lower annular (31) center, rotor (2) rotate connect in dabber (1), fixed body (3) fixed connection in dabber (1).

2. A ring groove sealed swivel joint as claimed in claim 1, wherein: the upper ring groove (21) comprises an upper closing plate (213), an upper inner ring body (211) and an upper outer ring body (212), wherein the upper inner ring body and the upper outer ring body are both of annular structures;

the upper outer ring body (212) is sleeved outside the upper inner ring body (211), the top of the upper inner ring body (211) and the top of the upper outer ring body (212) are both connected to the upper sealing plate (213), and the upper outer ring body (212), the upper inner ring body (211) and the upper sealing plate (213) enclose the first flow-through cavity (13); the end part of the upper connecting pipe (22) is connected with the outer wall of the upper outer ring body (212);

the lower ring groove (31) comprises a lower closing plate (313), a lower inner ring body (311) and a lower outer ring body (312), wherein the lower inner ring body and the lower outer ring body are both of annular structures;

the lower outer ring body (312) is sleeved outside the lower inner ring body (311), the bottom of the lower inner ring body (311) and the bottom of the lower outer ring body (312) are both connected to the lower sealing plate (313), and the lower outer ring body (312), the lower inner ring body (311) and the lower sealing plate (313) enclose the second flow-through cavity (14); the end of the lower connection pipe (32) is connected to the outer wall of the lower outer ring body (312).

3. A ring groove sealed swivel joint as claimed in claim 2, wherein: the upper inner ring body (211) is sleeved on the lower inner ring body (311), and the upper outer ring body (212) is sleeved on the lower outer ring body (312).

4. A ring groove sealed swivel joint as claimed in claim 3, wherein: an upper sealing groove is formed in the part, matched with the lower inner ring (311), of the upper inner ring (211), and an inner sealing element (6) is installed in the upper sealing groove, so that the upper inner ring (211) is in sealing connection with the lower inner ring (311) through the inner sealing element (6);

the upper outer ring body (212) and the lower outer ring body (312) are matched with each other, a lower sealing groove is formed in the position, matched with the lower outer ring body (312), of the upper outer ring body, and an outer sealing element (7) is installed in the lower sealing groove, so that the upper outer ring body (212) and the lower outer ring body (312) are connected in a sealing mode through the outer sealing element (7).

5. A ring groove sealed swivel joint as claimed in claim 2, wherein: a radial annular boss (214) is arranged on the side wall of the upper inner ring body (211), and a self-lubricating bearing (8) is arranged between the mandrel (1) and the upper inner ring body (211);

the lower end face of the self-lubricating bearing (8) is abutted against the top face of the lower inner ring body (311), and the upper end face of the self-lubricating bearing (8) is abutted against the lower end face of the radial annular boss (214).

6. A ring groove sealed swivel joint as claimed in claim 5, wherein: the device also comprises an end cover (9) and a supporting ring (10);

the upper end of the mandrel (1) penetrates through the upper inner ring body (211) and then is connected with the end cover (9);

the support ring (10) is sleeved outside the mandrel (1), and the support ring (10) is located between the radial annular boss (214) and the end cover (9).

7. A ring groove sealed swivel joint as claimed in claim 6, wherein: a labyrinth seal is arranged between the upper ring groove (21) and the end cover (9), and comprises an axial annular boss (215) and an annular groove (91);

annular groove (91) sets up the lower surface of end cover (9), axial annular boss (215) set up go up the upper surface of annular groove (21), axial annular boss (215) are located in annular groove (91).

8. A ring groove sealed swivel joint as claimed in claim 6, wherein: a gasket group (11) is arranged between the bottom of the end cover (9) and the end face of the mandrel (1), and the gasket group (11) comprises a plurality of stacked gaskets.

9. A ring groove sealed swivel joint as claimed in claim 2, wherein: also comprises a base (12) and a bottom plate (15);

the bottom end of the mandrel (1) is connected to the bottom plate (15), the bottom plate (15) is fixed to the base (12), and the lower surface of the lower sealing plate (313) is abutted to the upper surface of the bottom plate (15).

10. A ring groove sealed swivel joint as claimed in claim 1, wherein: the device also comprises a lower joint (4) and an upper joint (5);

the lower joint (4) is connected to one end, far away from the lower annular groove (31), of the lower connecting pipe (32), and the upper joint (5) is connected to one end, far away from the upper annular groove (21), of the upper connecting pipe (22).

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