WO2021134987A1

WO2021134987A1 - Airbag sealing device for side suction port of trailing suction hopper dredger

Info

Publication number: WO2021134987A1
Application number: PCT/CN2020/086164
Authority: WO
Inventors: 张春; 芮迪文; 李小波; 彭陵生; 李志朋; 陈康; 陆小霞; 王坤; 林海; 王成革; 汪英明; 徐景欣; 吕德永; 丁媛媛; 朱文博; 刘奇; 孔华杰; 汪开华; 杨涛; 王立东
Original assignee: 长江南京航道工程局
Priority date: 2019-12-30
Filing date: 2020-04-22
Publication date: 2021-07-08
Also published as: CN110939170A; CN110939170B

Abstract

The present invention relates to the technical field of dredging engineering machinery, and provides an airbag sealing device for a side suction port of a trailing suction hopper dredger, comprising a slider body, an airbag cavity, a tongue, a pressing plate, a reverse thrust spring, and an airbag. The airbag cavity is disposed on the side of the slider body towards the hull; the tongue is located in the airbag cavity; a protrusion at the top of the tongue is towards the hull; an elastic ring is fixed on the protrusion; the pressing plate is fixed to the slider and presses two sides of the protrusion of the tongue; the reverse thrust spring is located between the inner side of the pressing plate and the tongue; the airbag is located in a cavity between the tongue and the airbag cavity. The present invention has the following advantages: the elastic ring has a certain thickness and sufficient piston stroke compensation margin, can reduce abrasion, and can adapt to the relative movement between sealing surfaces and slight inclination, thereby maintaining good sealing performance; the airbag does not directly rub against a mud suction pipe, thereby avoiding the risk of machinery damage, reducing the incidence of failures, and prolonging the service life of the airbag; the airbag directly presses against the tongue, thereby ensuring the expansion and contraction reliability of the tongue.

Description

Airbag sealing device for side suction port of trailing suction dredger

Technical field

The invention belongs to the technical field of dredging engineering machinery, and specifically relates to a side suction airbag sealing device of a trailing suction dredger.

Background technique

The existing trailing suction dredger is a large self-propelled trailing suction dredger equipped with drag head excavators and hydraulic suction devices. When dredging, move the raking suction pipe along the ship’s side, and move the sliding block installed on the upper end of the raking suction pipe to the side of the suction pipe to connect with the suction port of the hull. The lower end of the raking suction pipe falls on the river/sea bed and is being dragged by the ship. The river/sea bed is broken by the weight of the drag head, and a sealed space is formed inside the drag head for mud mixing. The vacuum effect of the mud pump in the cabin is used to absorb the mud from the river/seabed through the drag head and suction pipe into the dredger. In the mud silo. However, this kind of mud suction method of the mud pump in the cabin has problems such as excessively long pipelines, high-power mud pumps, large equipment investment, high operating costs, and limited suction depth.

In order to solve the above problems, the method of putting the mud pump in front is adopted, that is, installing the mud pump in the middle section of the trailing suction pipe, so that the distance between the mud pump and the trailing head can be shortened, the construction efficiency can be improved, and the working depth of the dredger can be increased. However, when the mud pump in the cabin is used, the negative pressure between the trailing suction pipe slider and the suction port of the hull is always in a negative pressure state, and there is no problem of mud water leakage; and the mud pump is placed in front of the trailing suction pipe, and the trailing suction pipe is connected to the suction pipe. It is always under positive pressure. If there is no good sealing device to seal the interface, mud water leakage will occur. Since the interface is deep underwater and needs to be sealed after docking, the engineering is difficult and the control requirements are high. Due to the impact of the assembly gap between the slider and the side slide, the moment the drag head hits the ground, there is an instant relative movement between the slider and the suction buckle, and when the ship is dragging the rake straw, the river/seabed fluctuates, and The softness and hardness of the different areas at the bottom of the river/sea bed are also inconsistent. When the trailing suction head passes by, there is movement in the up and down, left and right directions, so that there is a relative movement between the slider and the suction port of the hull. At present, the slider sealing devices designed both internationally and domestically are of airbag type. The device is equipped with an annular airbag on the slider, and the airbag is inflated after docking, and the airbag is inflated and sealed. However, it was found in actual use that the airbag is extremely easy to damage, has a short service life, and is frequently replaced. The main causes of damage are friction damage, improper inflation pressure, and improper installation. Due to the relative movement between the slider and the mud suction port, it will rub against the inflated airbag; if the airbag inflation pressure is too small, the airbag will not have a sealing effect. When the pressure is too high, the airbag will be fatigued for a long time and shorten the service life, and no matter the air pressure is too high If it is too small, it will accelerate the wear of the airbag; because the airbag is an elastic part and lacks support, when it is installed in the slider, if it is installed improperly, it is easy to cause a small part of the airbag to protrude from the slider, which will cause damage when it is launched into the water. At present, many design units and shipyards in the industry are dealing with the issue of public relations, which has not been resolved.

Summary of the invention

In order to overcome the above technical problems, the present invention provides a side suction airbag sealing device of a trailing suction dredger.

In order to achieve the above objective, the present invention is achieved through the following technical solutions.

A trailing suction dredger's side suction airbag sealing device, which is characterized in that it comprises a slider body, an airbag cavity, a top tongue, a pressure plate, a reverse thrust spring, and an airbag;

The airbag cavity is an annular groove with an irregular rectangular cross section, which is arranged on the side of the slider body facing the hull. The opening direction of the annular groove faces the hull, and its diameter matches the diameter of the mud suction pipe of the hull. There is an opening; the airbag is ring-shaped, located in the cavity between the top tongue and the airbag cavity, and the air inlet tube of the airbag extends from the opening at the bottom of the airbag cavity;

The top tongue is a ring-shaped sliding block with a wide section at the bottom and a boss on the top to form a "convex" shape; the bottom of the top tongue is located in the airbag cavity, and the top boss of the top tongue faces the hull, and an elastic ring is fixed on the boss , The inner diameter, outer diameter and thickness of the bottom of the top tongue are matched with the air bag cavity;

The pressure plate is divided into an inner pressure plate and an outer pressure plate. The inner and outer pressure plates are both circular and connected with the slider body. The outside of the inner pressure plate presses the inner part of the top tongue boss, and the inside of the outer pressure plate presses the outer part of the top tongue boss. , The gap between the inner and outer pressure plates matches the width of the top tongue boss;

There are multiple sets of the reverse thrust springs evenly distributed along the circumference of the pressure plate, and there are two reverse thrust springs in each group, which are installed in the pressure plate and act on the end faces on both sides of the top tongue boss;

The pressure plate has a through hole at the place where the reverse thrust spring is provided, the bottom of the through hole is provided with a step, the top of the through hole is provided with a cover, and the cover is bolted to the pressure plate; the reverse thrust spring includes a top pin, a spring, and a circlip , The top pin is "T" shaped and divided into a pin rod and a pin seat. The diameter of the pin rod matches the through hole, the diameter of the pin seat matches the step, the pin rod passes through the through hole, the top of the pin rod is provided with a circlip, and the pin seat is tightly attached The top tongue and the spring are sleeved on the pin rod and located between the pin seat and the step.

The principle is: after the raking straw slider is docked with the suction port of the hull, compressed air is introduced through the air intake pipe to expand the airbag and push the top tongue out, and the elastic ring on the top of the top tongue squeezes the suction port buckle to form a seal . Since the airbag pushes the top tongue, there is no sliding friction between the airbag and the top tongue, which prolongs the service life of the airbag. When the operation is over, the air intake pipe stops passing compressed air, the airbag shrinks, and the top tongue retracts into the airbag cavity under the action of the reverse thrust spring to release the seal. The pressure plate not only acts as the force point of the reverse thrust spring, but also serves as the stopper of the top tongue. No matter how much the airbag expands, the change of the stroke of the top tongue will not damage the sealing plate of the disc spring assembly. The elastic ring has a certain thickness. Even if the abutting surface of the suction buckle ring and the slider is not completely parallel, a complete seal can be achieved by squeezing the elastic ring, and a good seal can be maintained even when the elastic material is worn to the limit thickness.

Further, the elastic ring adopts a self-lubricating polymer elastic ring. Due to the irregular shaking of the raking suction pipe, the elastic ring and the suction nozzle are in slight sliding friction, which will wear the elastic ring to a certain extent. Therefore, the use of the elastic ring made of self-lubricating polymer material can greatly reduce the degree of wear. Extend the maintenance cycle. The elastic ring has a certain thickness and sufficient compensation margin, and the wear within the stroke range of the piston does not affect the sealing effect. The polymer elastic material is selected from one of ultra-high molecular weight polyethylene, polytetrafluoroethylene, and nylon.

Further, an inner frame seal is provided between the inner pressure plate and the bosses, an inner ring groove is provided on the inner pressure plate, and an inner stop baffle is installed in the inner ring groove, and the inner stop baffle is close to the outer side of the inner frame seal An outer frame seal is provided between the outer pressure plate and the top tongue boss, an outer ring groove is provided on the outer pressure plate, and an outer stop baffle is installed in the outer ring groove, and the outer stop baffle is tightly attached to the outer frame to seal Outside. The muddy water needs to withstand the impact of the internal pressure plate and the boss. The pressure of the muddy water is relatively large, and it must rush into the gap between the internal pressure plate and the boss, which will adversely affect the reverse thrust spring. Therefore, a skeleton seal is provided between the inner pressure plate and the boss to prevent muddy water from entering. In order to fix the skeleton seal, an annular groove is provided on the pressure plate, and a stop baffle similar to a circlip is installed in the annular groove. Although there is no high-pressure muddy water between the outer pressure plate and the boss, only the water pressure at the location of the suction pipe, but considering the requirement of balanced friction on both sides of the boss, a skeleton seal is also set between the outer end cover and the boss.

Further, an inner airbag cavity skeleton seal is provided between the inner side of the top tongue bottom and the airbag cavity, and an outer airbag cavity skeleton seal is provided between the outer side of the top tongue bottom and the airbag cavity. Further reduce the chance of muddy water entering.

Further, there are two inner airbag cavity frame seals, and an inner spacer ring is arranged between the two inner airbag cavity frame seals; the outer airbag cavity frame seals have two, and the outer airbag cavity frame seals are located between the two outer airbag cavity frame seals. With external fixed distance ring. In view of the fact that in order to better seal the intrusion of muddy water, a double-frame seal is used. In order to make the double-frame seal work cooperatively and not interfere with each other, a distance ring is arranged between the two airbag cavity frame seals.

Furthermore, the airbag cavity is provided with two symmetrical stopping steps, the distance between the edge of the stopping step and the bottom of the airbag cavity is greater than the opening diameter, and the distance between the two stopping steps is smaller than the width of the bottom of the top tongue. When the top tongue moves underwater, excessive retraction of the top tongue will cause water to enter the airbag cavity and affect the life of the airbag cavity; secondly, the top tongue will squeeze the airbag and affect the life of the airbag; thirdly, the reverse spring may shift and cause failure. Therefore, the stroke of the top tongue should be limited.

Furthermore, wear-bearing rings are provided on the friction surfaces of the airbag cavity and the top tongue, and the pressure plate and the top tongue. Reduce the wear of the friction surface of the top tongue and prolong the service life.

Beneficial effects: Compared with the prior art, the advantages of the present invention are:

1) The self-lubricating polymer elastic ring on the top of the top tongue can effectively reduce the wear and tear, and can adapt to the relative movement between the slider and the mud suction port to maintain a good seal;

2) The airbag does not directly rub against the mud suction pipe, which prolongs the service life of the airbag;

3) The airbag directly pushes the top tongue to ensure the reliability of the expansion and contraction of the top tongue;

4) The piston stroke is much larger than the gap between the slider and the suction buckle ring, and the elastic ring has a certain thickness, and the compensation margin is sufficient, which greatly extends the service life of the sealing device.

Description of the drawings

Figure 1 is a schematic diagram of the position of the airbag sealing device in the slider;

Figure 2 is a schematic diagram of the airbag sealing device when the slider is docked with the mud suction port;

Figure 3 is a partial enlarged schematic view of the cross section of the airbag sealing device;

Figure 4 is a partial enlarged schematic view of the pressure plate in the airbag sealing device;

Figure 5 is a partial enlarged schematic view of the outer pressure plate of the airbag sealing device;

Among them, 11. Slider, 12. Airbag sealing device, 13. Suction pipe, 14. Hull, 21. Airbag cavity, 22. Stop step, 23. Airbag, 24. Air intake pipe, 31. Top tongue, 32. Elasticity Ring, 41. Internal pressure plate, 42. External pressure plate, 43. Cover, 51. Top pin, 52. Disc spring, 53. Circlip, 61. Wear ring, 71. Internal frame seal, 72. Internal stopper Plate, 73. Outer frame seal, 74. Outer stop baffle, 75. Inner airbag cavity frame seal, 76. Inner spacer ring, 77. Outer airbag cavity frame seal, 78. Outer spacer ring.

Detailed ways

The present invention will be further described in detail below in conjunction with examples. The raw materials used in the present invention are all commercially available products.

Example 1

A side suction airbag sealing device 12 of a trailing suction dredger includes a slider 11 body, an airbag cavity 21, a top tongue 31, a pressure plate, a reverse thrust spring, and an airbag 23.

The airbag cavity 21 is an annular groove with a rectangular cross-section. It is provided on the side of the slider 11 facing the hull 14. The opening direction of the annular groove faces the hull 14, and its diameter matches with the mouth of the mud suction pipe 13 of the hull 14. 21 has an opening at the bottom.

The top tongue 31 is an annular sliding block with a wide section at the bottom and a boss on the top to form a "convex" shape; the bottom of the top tongue 31 is located in the airbag cavity 21, and the top boss of the top tongue 31 faces the hull 14 and is fixed on the boss There is a self-lubricating polymer elastic ring 32, and the inner diameter, outer diameter, and thickness of the bottom of the top tongue 31 match the airbag cavity 21. The airbag 23 has a ring shape and is located in the cavity between the top tongue 31 and the airbag cavity 21. The air inlet tube 24 of the airbag 23 protrudes from the bottom opening of the airbag cavity 21. The pressure plate is divided into an inner pressure plate 41 and an outer pressure plate 42. The inner and outer pressure plates 42 are both circular. The inner side of the inner pressure plate 41 and the outer side of the outer pressure plate 42 are connected to the body of the slider 11, and the outer side of the inner pressure plate 41 presses the boss of the top tongue 31 In the inner part, the inner side of the outer pressure plate 42 presses the outer part of the boss of the top tongue 31, and the gap between the inner and outer pressure plates 42 matches the width of the boss of the top tongue 31. There are multiple sets of reverse thrust springs evenly distributed along the circumference of the pressure plate. The number of reverse thrust springs matches the diameter of the suction pipe 13 of the hull 14; there are two reverse thrust springs in each group, which are located on the inner and outer pressure plates 42 and the top tongue 31. Between the bottom; the pressure plate is provided with a through hole where the reverse thrust spring is provided, the bottom of the through hole is provided with a step, the top of the through hole is provided with a cover 43, the cover 43 is connected with the pressure plate by bolts; the reverse thrust spring includes a top pin 51, a disc The spring 52, the circlip 53, and the top pin 51 are in a "T" shape and are divided into a pin rod and a pin seat. The diameter of the pin rod matches the through hole, the diameter of the pin seat matches the step, the pin rod passes through the through hole, and the top of the pin rod is set The circlip 53, the pin seat is close to the top tongue 31, and the four disc springs 52 are sleeved on the pin rod in a face-to-face installation manner and are located between the pin seat and the step. The disc spring bears a great load in a small space. Compared with a spring, the deformation energy per unit volume is larger, and it has a good cushioning and shock absorption capacity. A wear ring 61 is provided on the friction surface of the airbag cavity 21 and the top tongue 31 and the pressure plate and the top tongue 31. The body of the slider 11 and the outer surface of the pressure plate are in the same plane, and the projecting distance of the top tongue 31 is greater than the distance between the body of the slider 11 and the mouth of the suction pipe 13 of the hull 14. The smoothness of the surface of the slider 11 is ensured and remains smooth during the sliding process.

Example 2

The airbag cavity 21 is an annular groove with a rectangular cross-section. It is provided on the side of the slider 11 facing the hull 14. The opening direction of the annular groove faces the hull 14, and its diameter matches with the mouth of the mud suction pipe 13 of the hull 14. 21 is provided with an opening at the bottom; the bottom of the airbag cavity 21 is provided with a stop step 22 above the opening, and the spacing of the stop steps 22 is smaller than the width of the bottom of the top tongue 31. The top tongue 31 is an annular sliding block with a wide section at the bottom and a boss on the top to form a "convex" shape; the bottom of the top tongue 31 is located in the airbag cavity 21, and the top boss of the top tongue 31 faces the hull 14 and is fixed on the boss There is a self-lubricating polymer elastic ring 32, and the inner diameter, outer diameter, and thickness of the bottom of the top tongue 31 match the airbag cavity 21. The airbag 23 has a ring shape and is located in the cavity between the top tongue 31 and the airbag cavity 21. The air inlet tube 24 of the airbag 23 protrudes from the bottom opening of the airbag cavity 21. The pressure plate is divided into an inner pressure plate 41 and an outer pressure plate 42. The inner and outer pressure plates 42 are both circular. The inner side of the inner pressure plate 41 and the outer side of the outer pressure plate 42 are connected to the body of the slider 11, and the outer side of the inner pressure plate 41 presses the boss of the top tongue 31 In the inner part, the inner side of the outer pressure plate 42 presses the outer part of the boss of the top tongue 31, and the gap between the inner and outer pressure plates 42 matches the width of the boss of the top tongue 31; the inner pressure plate 41 is provided with an inner skeleton seal 71 between the bosses , The inner pressure plate 41 is provided with an inner annular groove, an inner stop baffle 72 is installed in the inner annular groove, and the inner stop baffle 72 is close to the outside of the inner frame seal 71; an outer frame is provided between the outer pressure plate 42 and the bosses Seal 73, the outer pressure plate 42 is provided with an outer annular groove, an outer stop baffle 74 is installed in the outer annular groove, and the outer stop baffle 74 is close to the outside of the outer frame seal 73. There are multiple sets of reverse thrust springs evenly distributed along the circumference of the pressure plate. The number of reverse thrust springs matches the diameter of the suction pipe 13 of the hull 14; there are two reverse thrust springs in each group, which are located on the inner and outer pressure plates 42 and the top tongue 31. Between the bottom; the pressure plate is provided with a through hole where the reverse thrust spring is provided, the bottom of the through hole is provided with a step, the top of the through hole is provided with a cover 43, the cover 43 is connected with the pressure plate by bolts; the reverse thrust spring includes a top pin 51, a disc The spring 52, the circlip 53, and the top pin 51 are in a "T" shape and are divided into a pin rod and a pin seat. The diameter of the pin rod matches the through hole, the diameter of the pin seat matches the step, the pin rod passes through the through hole, and the top of the pin rod is set The circlip 53, the pin seat is close to the top tongue 31, and the four disc springs 52 are sleeved on the pin rod in a face-to-face installation manner and are located between the pin seat and the step. A wear ring 61 is provided on the friction surface of the airbag cavity 21 and the top tongue 31 and the pressure plate and the top tongue 31. The body of the slider 11 and the outer surface of the pressure plate are in the same plane, and the projecting distance of the top tongue 31 is greater than the distance between the body of the slider 11 and the mouth of the suction pipe 13 of the hull 14.

Example 3

As shown in Figures 1 to 5, a trailing suction dredger side suction airbag sealing device 12 includes a slider 11 body, an airbag cavity 21, a top tongue 31, a pressure plate, a reverse thrust spring, and an airbag 23.

The airbag cavity 21 is an annular groove with a rectangular cross-section. It is provided on the side of the slider 11 facing the hull 14. The opening direction of the annular groove faces the hull 14, and its diameter matches with the mouth of the mud suction pipe 13 of the hull 14. 21 is provided with an opening at the bottom; the bottom of the airbag cavity 21 is provided with a stop step 22 above the opening, and the spacing of the stop steps 22 is smaller than the width of the bottom of the top tongue 31. The top tongue 31 is an annular sliding block with a wide section at the bottom and a boss on the top to form a "convex" shape; the bottom of the top tongue 31 is located in the airbag cavity 21, and the top boss of the top tongue 31 faces the hull 14 and is fixed on the boss There is a self-lubricating polymer elastic ring 32, and the inner diameter, outer diameter, and thickness of the bottom of the top tongue 31 match the airbag cavity 21. The airbag 23 has a ring shape and is located in the cavity between the top tongue 31 and the airbag cavity 21. The air inlet tube 24 of the airbag 23 protrudes from the bottom opening of the airbag cavity 21. An inner airbag cavity skeleton seal 75 is provided between the bottom inner side of the top tongue 31 and the airbag cavity 21, and an outer airbag cavity skeleton seal 77 is provided between the bottom outer side of the top tongue 31 and the airbag cavity 21. There are two inner airbag cavity skeleton seals 75, and an inner spacer ring 76 is provided between the two inner airbag cavity skeleton seals 75; there are two outer airbag cavity skeleton seals 77, which are provided between the two outer airbag cavity skeleton seals 77 There is an outer fixed distance ring 78. The pressure plate is divided into an inner pressure plate 41 and an outer pressure plate 42. The inner and outer pressure plates 42 are both circular. The inner side of the inner pressure plate 41 and the outer side of the outer pressure plate 42 are connected to the body of the slider 11, and the outer side of the inner pressure plate 41 presses the boss of the top tongue 31 In the inner part, the inner side of the outer pressure plate 42 presses the outer part of the boss of the top tongue 31, and the gap between the inner and outer pressure plates 42 matches the width of the boss of the top tongue 31. The inner pressure plate 41 is provided with an inner frame seal 71 between the bosses, an inner ring groove is provided on the inner pressure plate 41, an inner stop baffle 72 is installed in the inner ring groove, and the inner stop baffle 72 is close to the inner frame seal 71 outside; the outer frame seal 73 is provided between the outer pressure plate 42 and the boss, the outer pressure plate 42 is provided with an outer annular groove, and an outer stop baffle 74 is installed in the outer ring groove, and the outer stop baffle 74 is close to the outside The frame seal 73 outside. There are multiple sets of reverse thrust springs evenly distributed along the circumference of the pressure plate. The number of reverse thrust springs matches the diameter of the suction pipe 13 of the hull 14; there are two reverse thrust springs in each group, which are located on the inner and outer pressure plates 42 and the top tongue 31. Between the bottom. The pressure plate has a through hole at the place where the reverse thrust spring is provided, the bottom of the through hole is provided with a step, and the top of the through hole is provided with a cover 43, which is connected with the pressure plate by bolts; the reverse thrust spring includes a top pin 51, a disc spring 52, and a clamp. The spring 53 and the top pin 51 are in a "T" shape and are divided into a pin rod and a pin seat. The diameter of the pin rod matches the through hole, and the diameter of the pin seat matches the step. The pin rod passes through the through hole, and a circlip 53 is set on the top of the pin rod. The pin seat is close to the top tongue 31, and the four disc springs 52 are sleeved on the pin rod in a face-to-face installation manner and are located between the pin seat and the step. A wear ring 61 is provided on the friction surface of the airbag cavity 21 and the top tongue 31 and the pressure plate and the top tongue 31. The body of the slider 11 and the outer surface of the pressure plate are in the same plane, and the projecting distance of the top tongue 31 is greater than the distance between the body of the slider 11 and the mouth of the suction pipe 13 of the hull 14.

The present invention has been described in accordance with the above-mentioned embodiments. It should be understood that the above-mentioned embodiments do not limit the present invention in any form, and all technical solutions obtained by equivalent substitutions or equivalent transformations fall within the protection scope of the present invention.

Claims

A trailing suction dredger's side suction airbag sealing device, which is characterized in that it comprises a slider body, an airbag cavity, a top tongue, a pressure plate, a reverse thrust spring, and an airbag;

The airbag cavity is an annular groove with an irregular rectangular cross section, which is arranged on the side of the slider body facing the hull. The opening direction of the annular groove faces the hull, and its diameter matches the diameter of the mud suction pipe of the hull. There is an opening; the airbag is ring-shaped, located in the cavity between the top tongue and the airbag cavity, and the air inlet tube of the airbag extends from the opening at the bottom of the airbag cavity;

The top tongue is a ring-shaped sliding block with a wide section at the bottom and a boss on the top to form a "convex" shape; the bottom of the top tongue is located in the airbag cavity, and the top boss of the top tongue faces the hull, and an elastic ring is fixed on the boss , The inner diameter, outer diameter and thickness of the bottom of the top tongue are matched with the air bag cavity;

The pressure plate is divided into an inner pressure plate and an outer pressure plate. The inner and outer pressure plates are both circular and connected with the slider body. The outside of the inner pressure plate presses the inner part of the top tongue boss, and the inside of the outer pressure plate presses the outer part of the top tongue boss. , The gap between the inner and outer pressure plates matches the width of the top tongue boss;

There are multiple sets of the reverse thrust springs evenly distributed along the circumference of the pressure plate, and there are two reverse thrust springs in each group, which are installed in the pressure plate and act on the end faces on both sides of the top tongue boss;

The pressure plate has a through hole at the place where the reverse thrust spring is provided, the bottom of the through hole is provided with a step, the top of the through hole is provided with a cover, and the cover is bolted to the pressure plate; the reverse thrust spring includes a top pin, a spring, and a circlip , The top pin is "T" shaped and divided into a pin rod and a pin seat. The diameter of the pin rod matches the through hole, the diameter of the pin seat matches the step, the pin rod passes through the through hole, the top of the pin rod is provided with a circlip, and the pin seat is tightly attached The top tongue and the spring are sleeved on the pin rod and located between the pin seat and the step.
The side suction airbag sealing device of a trailing suction dredger according to claim 1, wherein the elastic ring is a self-lubricating polymer elastic ring.
The side suction airbag sealing device of a trailing suction dredger according to claim 1, wherein an inner frame seal is provided between the inner pressure plate and the top tongue boss, and an inner ring is provided on the inner pressure plate. Groove, an inner stop baffle is installed in the inner annular groove, and the inner stop baffle is close to the outside of the inner frame seal; an outer frame seal is provided between the outer pressure plate and the top tongue boss, and the outer pressure plate is provided with an outer frame seal. An annular groove, an outer stop baffle is installed in the outer annular groove, and the outer stop baffle is close to the outside of the outer frame seal.
The side suction airbag sealing device of a trailing suction dredger according to claim 1, wherein an inner airbag cavity skeleton seal is provided between the inner side of the bottom of the top tongue and the airbag cavity, and the top tongue An outer airbag cavity frame seal is arranged between the outer side of the bottom and the airbag cavity.
The side suction airbag sealing device of a trailing suction dredger according to claim 4, wherein there are two inner airbag cavity frame seals, and an internal fixed distance is provided between the two inner airbag cavity frame seals. Ring; There are two outer air bag cavity frame seals, and an outer distance ring is provided between the two outer air bag cavity frame seals.
The side suction airbag sealing device of a trailing suction dredger according to claim 1, wherein the airbag cavity is provided with two symmetrical stop steps, and the edge of the stop step is away from the bottom of the airbag cavity. The distance is larger than the opening diameter, and the distance between the two stop steps is smaller than the width of the bottom of the top tongue.
The side suction airbag sealing device of a trailing suction dredger according to claim 1, wherein a wear bearing ring is provided on the friction surface between the airbag cavity and the top tongue, and the pressure plate and the top tongue.