Pressure relief sealing system of slurry balance shield tunneling machine

Abstract

Compared with the prior art, the pressure relief sealing system of the slurry balance shield tunneling machine comprises a labyrinth pressing ring which is installed on a driving disc and used for sealing a gap between the driving disc and a driving box. The sealing body structure is mounted on the inner side of the driving box, and a sealing cavity is formed between the sealing body structure and the driving disc; the first finger-shaped seal, the second finger-shaped seal and the lip-shaped seal are sequentially mounted on the driving disc, and the first finger-shaped seal, the second finger-shaped seal and the lip-shaped seal sequentially divide a sealing cavity into a pressure relief cavity, a first grease cavity and a second grease cavity; the pressure relief channel is communicated with the pressure relief cavity; a grease filling channel; a labyrinth structure is formed between the labyrinth pressing ring and the driving box and is communicated with the pressure relief cavity; according to the scheme, the problem that a sealing system of a main drive consumes a large amount of lubricating grease when the shield tunneling machine works in a high-pressure muddy water environment is solved, the service life of a finger-shaped seal and a lip-shaped seal of the main drive when the shield tunneling machine works in the high-pressure muddy water environment is prolonged, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of shield machines, in particular to a pressure relief sealing system for a slurry balance shield machine. Background Art

[0002] With the rapid development of tunnel construction technology and theory in my country and the increasing level of construction mechanization, the number of tunnel projects constructed using shield machines has increased rapidly. Among them, slurry shield machines have the advantages of high automation, high construction efficiency, and low labor intensity. They are widely used in various large-section tunnel projects, especially in tunnel projects that cross rivers, cross seas, and have high requirements for settlement.

[0003] The main drive seal of the slurry shield machine is mainly installed with a sealing system, which is mainly used to isolate external mud and water. The mud and water pressure can reach 10Bar. The sealing effect is critical to the normal operation of the slurry shield machine. If the sealing system fails, mud and water will enter the inside of the shield machine, which will cause the shield machine to stop working at the least, and the entire tunnel will be flooded with mud at the worst. In the prior art, the main drive sealing system of the current slurry shield machine is divided into an external seal and an internal seal. The more commonly used structure is mainly composed of two finger seals, a lip seal, and three lubricating greases. In order to prevent external pressure mud and water, the lubricating grease must be injected under pressure, and the lubricating grease must be consumed in large quantities. In the prior art, the pressure of the mud and water is relatively high and the lubricating grease is injected under pressure, which greatly affects the service life of the finger seal and the lip seal. That is, the sealing system in the prior art consumes a large amount of lubricating grease, and the service life of the finger seal and the lip seal is relatively low, and the cost of use is high.

[0004] Therefore, how to provide a slurry shield machine pressure relief sealing system that can overcome the technical problems in the prior art, relatively extend the relatively low service life of finger seals and lip seals, and reduce the cost of use has become a technical problem that needs to be urgently solved by technical personnel in this field. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a slurry shield machine pressure relief sealing system, which can solve the problem of large amount of lubricating grease consumption in the main drive sealing system of the slurry shield machine, and can extend the service life of the main drive seal of the slurry shield machine and reduce the cost of use.

[0006] The technical solution provided by the utility model is as follows:

[0007] The utility model provides a pressure relief sealing system for a slurry balance shield machine, comprising: a drive box,

[0008] A drive disk disposed at a port of the drive box;

[0009] A labyrinth pressure ring installed on the driving disc and used to seal the gap between the driving disc and the driving box;

[0010] A sealing body structure installed inside the drive box, wherein a sealing cavity is formed between the sealing body structure and the drive disc;

[0011] A first finger seal, a second finger seal, and a lip seal are sequentially installed on the driving disk, wherein the first finger seal, the second finger seal, and the lip seal sequentially divide the sealing cavity into a pressure relief cavity, a first grease cavity, and a second grease cavity;

[0012] A pressure relief passage provided on the sealing body structure and communicating with the pressure relief chamber;

[0013] A grease filling channel is provided on the sealing body structure and is used to fill grease into the sealing cavity.

[0014] Wherein, a labyrinth structure is formed between the labyrinth pressure ring and the driving box, and the labyrinth structure is connected to the pressure relief chamber.

[0015] Among them, the maze structure is the first pressure relief sealing structure, the pressure relief chamber and the pressure relief channel are filled with grease to form the second pressure relief sealing structure, the first finger seal and the first grease chamber are filled with grease to form the third pressure relief sealing structure, and the second finger seal and the second grease chamber are filled with grease to form the fourth pressure relief sealing structure.

[0016] Further, in a preferred embodiment of the present invention, the first finger seal is installed on the driving disk in the following manner: the first finger seal is pressed and installed on the driving disk by a first finger seal pressing plate and a second finger seal pressing plate;

[0017] The second finger seal is installed on the driving disc specifically as follows: the second finger seal is pressed and fixed on the driving disc by a third finger seal pressing plate and a fourth finger seal pressing plate.

[0018] Furthermore, in a preferred embodiment of the present invention, the lip seal is installed on the drive disc in the following manner: the lip seal is pressed and fixed on the drive disc by a fourth finger-shaped seal pressure plate and a lip seal pressure plate.

[0019] Further, in a preferred embodiment of the present invention, the sealing body structure comprises: a sealing ring disposed inside the driving box;

[0020] A wear-resistant pressure plate disposed at the end of the sealing ring, the wear-resistant pressure plate being used to cooperate with the first finger seal;

[0021] a first wear-resistant ring plate disposed inside the sealing ring, the first wear-resistant ring plate being used to cooperate with the second finger seal;

[0022] A second wear-resistant ring plate is arranged on the inner side of the sealing ring, and the second wear-resistant ring plate is used to cooperate with the lip seal.

[0023] Furthermore, in a preferred embodiment of the present invention, the sealing structure further comprises:

[0024] A first O-ring and a second O-ring installed in the O-ring groove on the end surface of the sealing ring;

[0025] a third O-ring installed in the O-ring groove on the side of the sealing ring;

[0026] The first O-ring and the second O-ring are pressed tightly in the end surface O-ring groove of the sealing ring by the wear-resistant pressure plate.

[0027] Furthermore, in a preferred embodiment of the utility model, it also includes: an internal cooling circulating water channel provided between the drive box and the drive disc.

[0028] Furthermore, in a preferred embodiment of the present invention, the inner cooling circulating water channel comprises:

[0029] A first circulating cooling water channel for dissipating heat for the wear-resistant pressure plate through internal circulating cooling water; a second circulating cooling water channel for dissipating heat for the first wear-resistant ring plate through internal circulating cooling water; and a third circulating cooling water channel for dissipating heat for the second wear-resistant ring plate through internal circulating cooling water.

[0030] Furthermore, in a preferred embodiment of the present invention, the grease filling channel includes:

[0031] A first grease filling channel disposed on the sealing body structure and communicating with the first grease chamber;

[0032] A second grease filling channel is provided on the sealing body structure and communicated with the second grease cavity.

[0033] Furthermore, in a preferred embodiment of the present invention, the pressure relief channel is connected to a pressure relief pump or a slurry discharge pump of the mud and water circulation system.

[0034] Furthermore, in a preferred embodiment of the present invention, it further comprises: a pressure sensor disposed in the pressure relief chamber.

[0035] The utility model provides a pressure relief sealing system for a slurry shield machine, which, compared with the prior art, comprises: a drive box, a drive disc arranged at a port of the drive box; a labyrinth pressure ring installed on the drive disc and used to seal the gap between the drive disc and the drive box; a sealing body structure installed on the inner side of the drive box, a sealing cavity being formed between the sealing body structure and the drive disc; a first finger seal, a second finger seal, and a lip seal which are sequentially installed on the drive disc, the first finger seal, the second finger seal, and the lip seal sequentially dividing the sealing cavity into a pressure relief cavity, a first grease cavity, and a second grease cavity; a pressure relief channel which is arranged on the sealing body structure and communicates with the pressure relief cavity; and a grease filling channel which is arranged on the sealing body structure and is used to fill grease into the sealing cavity. Among them, the labyrinth pressure ring and the drive box form a labyrinth structure, and the labyrinth structure is connected to the pressure relief chamber. Compared with the prior art, the pressure relief sealing system of the mud water balance shield provided by the utility model reduces the mud water pressure reaching the finger seal to or close to the natural state pressure by adding a pressure relief chamber and a pressure relief channel, thereby reducing the filling pressure of grease and reducing the consumption of grease, solving the problem of large consumption of lubricating grease by the main drive sealing system of the shield machine working in a high-pressure mud water environment. At the same time, the reduction of the pressure of the use environment of the finger seal and the lip seal can effectively extend their service life, thereby extending the service life of the finger seal and the lip seal of the main drive of the shield machine working in a high-pressure mud water environment and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic diagram of a slurry shield machine pressure relief sealing system provided in an embodiment of the utility model installed between a drive box and a drive disc.

[0038] Figure 2 A cross-sectional view of the pressure relief sealing system of the slurry shield machine provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solutions in the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the utility model.

[0040] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0041] It should be understood that the terms "length", "width", "up", "down", "front", "back", "first", "second", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" and "several" is two or more, unless otherwise clearly and specifically defined.

[0043] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present utility model can be implemented, so they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical contents disclosed in the present utility model without affecting the effects and purposes that can be achieved by the present utility model.

[0044] like Figure 1 to Figure 2As shown, the pressure relief sealing system of a slurry shield machine provided by an embodiment of the utility model includes: a drive box 1, a drive disk 8 arranged at the port of the drive box 1; a labyrinth pressure ring 2 installed on the drive disk 8 and used to seal the gap between the drive disk 8 and the drive box 1; a sealing body structure installed on the inner side of the drive box 1, and a sealed cavity is formed between the sealing body structure and the drive disk 8; a first finger seal 5, a second finger seal 11, and a lip seal 13 installed on the drive disk 8 in sequence, and the first finger seal 5, the second finger seal 11, and the lip seal 13 divide the sealed cavity into a pressure relief cavity 18, a first grease cavity 21, and a second grease cavity 24 in sequence; a pressure relief channel 19 arranged on the sealing body structure and connected to the pressure relief cavity 18; a grease filling channel arranged on the sealing body structure and used for filling grease into the sealed cavity.

[0045] The utility model provides a pressure relief sealing system for a slurry shield machine, which, compared with the prior art, comprises: a drive box 1, a drive disk 8 arranged at a port of the drive box 1; a labyrinth pressure ring 2 installed on the drive disk 8 and used for sealing a gap between the drive disk 8 and the drive box 1; a sealing body structure installed on the inner side of the drive box 1, a sealing cavity is formed between the sealing body structure and the drive disk 8; a first finger seal 5, a second finger seal 11, and a lip seal 13 installed on the drive disk 8 in sequence, the first finger seal 5, the second finger seal 11, and the lip seal 13 divide the sealing cavity into a pressure relief cavity 18, a first grease cavity 21, and a second grease cavity 24 in sequence; a pressure relief channel 19 arranged on the sealing body structure and connected to the pressure relief cavity 18; and a grease filling channel arranged on the sealing body structure and used for filling grease into the sealing cavity. Among them, the labyrinth pressure ring 2 and the drive box 1 form a labyrinth structure 17, and the labyrinth structure 17 is connected to the pressure relief chamber 18. Compared with the prior art, the pressure relief sealing system of the mud water balance shield provided by the utility model reduces the mud water pressure reaching the finger seal to or close to the natural state pressure by adding a pressure relief chamber and a pressure relief channel, thereby reducing the filling pressure of grease and reducing the consumption of grease, solving the problem of large consumption of lubricating grease by the main drive sealing system of the shield machine working in a high-pressure mud water environment. At the same time, the reduction of the pressure of the use environment of the finger seal and the lip seal can effectively extend their service life, thereby extending the service life of the finger seal and the lip seal of the main drive of the shield machine working in a high-pressure mud water environment and reducing costs.

[0046] The technical solution of the utility model is described in detail below in conjunction with specific embodiments:

[0047] Specifically, in a specific embodiment of the present utility model, the first finger seal 5 is installed on the driving disk 8 specifically as follows: the first finger seal 5 is pressed and installed on the driving disk 8 by the first finger seal pressing plate 4 and the second finger seal pressing plate 7;

[0048] The second finger seal 11 is installed on the driving disc 8 specifically as follows: the second finger seal 11 is pressed and fixed on the driving disc 8 by a third finger seal pressing plate 10 and a fourth finger seal pressing plate 12 .

[0049] In a specific embodiment of the utility model, the labyrinth pressure ring can be installed at the entrance or exit of the labyrinth sealing chamber in contact with the external environment, which can prevent the intrusion of external media such as mud and water. At the same time, the compression effect of the labyrinth pressure ring can effectively reduce the risk of leakage at this location.

[0050] Specifically, in a specific embodiment of the present utility model, the lip seal 13 is installed on the drive disk 8 in the following manner: the lip seal 13 is pressed and fixed on the drive disk 8 by the fourth finger-shaped seal pressure plate 12 and the lip seal pressure plate 14 .

[0051] Specifically, in a specific embodiment of the present utility model, the sealing body structure includes: a sealing ring 15 arranged on the inner side of the driving box 1;

[0052] A wear-resistant pressure plate 9 provided at the end of the sealing ring 15, wherein the wear-resistant pressure plate 9 is used for sealingly cooperating with the first finger seal 5;

[0053] A first wear-resistant ring plate disposed inside the sealing ring 15, the first wear-resistant ring plate being used for sealingly cooperating with the second finger seal 11;

[0054] A second wear-resistant ring plate is arranged inside the sealing ring 15 , and the second wear-resistant ring plate is used for sealingly cooperating with the lip seal 13 .

[0055] Specifically, in a specific embodiment of the present utility model, the sealing body structure further includes:

[0056] A first O-ring 3 and a second O-ring 6 installed in the O-ring groove on the end surface of the sealing ring 15;

[0057] A third O-ring 16 installed in the O-ring groove on the side of the sealing ring 15;

[0058] The first O-ring 3 and the second O-ring 6 are pressed tightly into the end surface O-ring groove of the sealing ring 15 by the wear-resistant pressure plate 9 .

[0059] Specifically, in a specific embodiment of the utility model, it also includes: an internal cooling circulating water channel provided between the drive box 1 and the drive disc 8.

[0060] Specifically, in a specific embodiment of the utility model, the inner cooling circulating water channel includes:

[0061] A first circulating cooling water channel 20 for dissipating heat for the wear-resistant pressure plate 9 through internal circulating cooling water; a second circulating cooling water channel 23 for dissipating heat for the first wear-resistant ring plate through internal circulating cooling water; and a third circulating cooling water channel 26 for dissipating heat for the second wear-resistant ring plate through internal circulating cooling water.

[0062] Specifically, in a specific embodiment of the utility model, the grease filling channel includes:

[0063] A first grease filling channel 22 disposed on the sealing body structure and communicating with the first grease chamber 21;

[0064] A second grease filling passage 25 is provided on the sealing body structure and communicated with the second grease chamber 24 .

[0065] Specifically, in a specific embodiment of the present utility model, the pressure relief channel 19 is connected to a pressure relief pump or a slurry discharge pump of the mud and water circulation system.

[0066] Specifically, in a specific embodiment of the present utility model, it also includes: a pressure sensor disposed in the pressure relief chamber 18 .

[0067] In the embodiment of the utility model, by adding a pressure relief chamber and a pressure relief channel, the muddy water pressure reaching the finger seal is reduced to or close to the natural pressure to reduce the filling pressure of grease, reduce the consumption of grease, and solve the problem of large consumption of lubricating grease by the sealing system of the main drive of the shield machine when working in a high-pressure muddy water environment. At the same time, the reduction of the operating environment pressure of the finger seal and the lip seal can effectively extend their service life. In this way, the service life of the finger seal and the lip seal of the main drive of the shield machine when working in a high-pressure muddy water environment can be extended and the equipment use cost can be reduced.

[0068] To elaborate more specifically, with the rapid development of tunnel construction technology and theoretical level in my country and the increasing level of construction mechanization, the number of tunnel engineering projects constructed by shield machines has increased rapidly. Among them, slurry shield machines have the advantages of high degree of automation, high construction efficiency, and low labor intensity of workers. They are widely used in various large-section tunnel projects, especially in tunnel projects across rivers, across seas, and with high requirements for settlement. The main drive seal of the slurry shield machine is mainly installed with a sealing system, which is mainly used to isolate external mud and water. The mud and water pressure can reach 10Bar. The sealing effect is critical to the normal operation of the slurry shield machine. If the sealing system fails, mud and water will enter the shield machine, which will cause the shield machine to stop working at the least, and the entire tunnel will be flooded with mud at the worst. At present, the main drive sealing system of the slurry shield machine is divided into external seal and internal seal. The more commonly used structure is mainly composed of two finger seals, one lip seal, and three lubricating greases. In order to prevent external pressure mud and water, lubricating grease must be injected under pressure, and the lubricating grease must be consumed in large quantities. Since the pressure of muddy water is relatively high and lubricating grease is injected under pressure, the service life of finger seal and lip seal is greatly affected. In summary, the sealing system in the prior art consumes a large amount of lubricating grease, the service life of finger seal and lip seal is relatively short, and the use cost is high.

[0069] The technical solution involved in the embodiment of the utility model can solve the problem that the main drive sealing system of the slurry shield machine consumes a large amount of lubricating grease, and can extend the service life of the main drive sealing of the slurry shield machine. Specifically, according to Figure 1 , Figure 2As shown, the pressure relief sealing system is mainly installed between the drive box 1 and the drive disc 8, and specifically includes: a labyrinth pressure ring 2, a first O-ring 3, a first finger-shaped sealing pressure plate 4, a first finger seal 5, a second O-ring 6, a second finger-shaped sealing pressure plate 7, a wear-resistant pressure plate 9, a third finger-shaped sealing pressure plate 10, a second finger seal 11, a fourth finger-shaped sealing pressure plate 12, a lip seal 13, a lip seal pressure plate 14, a sealing ring 15 and a third O-ring 16. Among them, the labyrinth pressure ring 2, the first finger-shaped sealing pressure plate 4, the second finger-shaped sealing pressure plate 7, the third finger-shaped sealing pressure plate 10, the fourth finger-shaped sealing pressure plate 12, and the lip-shaped sealing pressure plate 14 are installed on the driving disk 8 by screws, the first finger-shaped seal 5 is pressed and fixed on the driving disk 8 by the first finger-shaped sealing pressure plate 4 and the second finger-shaped sealing pressure plate 7, the second finger-shaped seal 11 is pressed and fixed on the driving disk 8 by the third finger-shaped sealing pressure plate 10 and the fourth finger-shaped sealing pressure plate 12, the lip-shaped seal 13 is pressed and fixed on the driving disk 8 by the fourth finger-shaped sealing pressure plate 12 and the lip-shaped sealing pressure plate 14, the first O-ring 3 and the second O-ring 6 are installed in the O-ring groove on the end face of the sealing ring 15, and are pressed by the wear-resistant pressure plate 9. The third O-ring 16 is installed in the O-ring groove on the side of the sealing ring 15. The labyrinth structure 17 is the first seal of the pressure relief sealing system, the pressure relief chamber 18 and the pressure relief channel 19 form the second seal of the pressure relief sealing system, the pressure relief chamber 18 is equipped with a pressure sensor, the first first finger seal 5 and the first grease chamber 21 are filled with grease to form the third seal of the pressure relief sealing system, the second second finger seal 11 and the second grease chamber 24 are filled with grease to form the fourth seal of the pressure relief sealing system, and the lip seal 13 is the fifth seal of the pressure relief sealing system. The first circulating cooling water channel 20, the second circulating cooling water channel 223 and the third circulating cooling water channel 26 dissipate heat to the sealing system through internal circulating cooling water.

[0070] In the embodiment of the utility model, the mud water pressure of the working environment of the mud water balance shield machine is P0 which can reach 10Bar. The mud water passes through the maze structure 17 and its pressure decays to P1 and reaches the pressure relief chamber 18. The pressure is relieved through the pressure relief channel 19 to reduce the mud water pressure to or close to the natural state pressure P2. The pressure relief channel 19 is connected to the pressure relief pump or to the slurry pump of the mud water circulation system. The pressure P2 of the mud water reaching the first finger seal 5 is much lower than P0, so the filling grease pressure P3 of the first grease filling channel 22 is much lower than the filling grease pressure of other sealing systems, P4=P3+P Δ， P Δ The finger seal passing pressure, so the grease filling pressure P4 of the second grease filling channel 25 is much lower than the grease filling pressure of other sealing systems, P4 = P3 + P Δ .

[0071] In summary, the design of the new main drive pressure relief sealing system of the slurry shield machine involved in the embodiment of the utility model reduces the pressure of the slurry reaching the finger seal to or close to the natural pressure by adding a pressure relief chamber and a pressure relief channel, thereby reducing the filling pressure of grease and reducing the consumption of grease, solving the problem of the main drive sealing system consuming a large amount of lubricating grease when the shield machine works in a high-pressure slurry environment. At the same time, the reduction of the pressure of the use environment of the finger seal and the lip seal can effectively extend their service life, thereby extending the service life of the main drive finger seal and the lip seal of the shield machine working in a high-pressure slurry environment and reducing costs, which has significant technical effects.

[0072] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A slurry shield machine pressure relief sealing system, characterized in that: include: Drive box (1), A drive disk (8) disposed at a port of the drive box (1); A labyrinth pressure ring (2) mounted on the driving disk (8) and used to seal a gap between the driving disk (8) and the driving box (1); A sealing body structure installed inside the drive box (1), wherein a sealed cavity is formed between the sealing body structure and the drive disc (8); A first finger seal (5), a second finger seal (11), and a lip seal (13) are sequentially mounted on the drive disk (8), wherein the first finger seal (5), the second finger seal (11), and the lip seal (13) sequentially divide the sealing cavity into a pressure relief cavity (18), a first grease cavity (21), and a second grease cavity (24); a pressure relief passage (19) disposed on the sealing body structure and communicating with the pressure relief chamber (18); A grease filling channel provided on the sealing body structure and used for filling grease into the sealing cavity; A labyrinth structure (17) is formed between the labyrinth pressure ring (2) and the drive box (1), and the labyrinth structure (17) is in communication with the pressure relief chamber (18).

2. The slurry shield machine pressure relief sealing system according to claim 1, characterized in that: The first finger-shaped seal (5) is installed on the driving disk (8) in the following manner: the first finger-shaped seal (5) is installed on the driving disk (8) by being pressed by a first finger-shaped seal pressing plate (4) and a second finger-shaped seal pressing plate (7); The second finger-shaped seal (11) is installed on the driving disc (8) in the following manner: the second finger-shaped seal (11) is pressed and fixed on the driving disc (8) by a third finger-shaped seal pressing plate (10) and a fourth finger-shaped seal pressing plate (12).

3. The pressure relief sealing system of a slurry shield machine according to claim 2, characterized in that: The lip seal (13) is installed on the drive disc (8) in the following manner: the lip seal (13) is pressed and fixed on the drive disc (8) by a fourth finger seal pressure plate (12) and a lip seal pressure plate (14).

4. The slurry shield machine pressure relief sealing system according to claim 1, characterized in that: The sealing body structure comprises: a sealing ring (15) arranged on the inner side of the driving box (1); a wear-resistant pressure plate (9) disposed at the end of the sealing ring (15), the wear-resistant pressure plate (9) being used for sealingly cooperating with the first finger seal (5); a first wear-resistant ring plate arranged on the inner side of the sealing ring (15), the first wear-resistant ring plate being used for sealingly cooperating with the second finger seal (11); A second wear-resistant ring plate is arranged on the inner side of the sealing ring (15), and the second wear-resistant ring plate is used for sealingly cooperating with the lip seal (13).

5. The slurry shield machine pressure relief sealing system according to claim 4, characterized in that: The sealing structure further comprises: A first O-ring (3) and a second O-ring (6) installed in the O-ring groove on the end surface of the sealing ring (15); A third O-ring (16) installed in the O-ring groove on the side of the sealing ring (15); The first O-ring (3) and the second O-ring (6) are pressed tightly into the O-ring groove on the end surface of the sealing ring (15) by the wear-resistant pressure plate (9).

6. The slurry shield machine pressure relief sealing system according to claim 4, characterized in that: Also includes: An internal cooling circulating water channel is provided between the drive box (1) and the drive disc (8).

7. The pressure relief sealing system for a slurry shield machine according to claim 6, characterized in that: The inner cooling circulating water channel comprises: a first circulating cooling water channel (20) for dissipating heat for the wear-resistant pressure plate (9) via internal circulating cooling water; a second circulating cooling water channel (23) for dissipating heat for the first wear-resistant ring plate via internal circulating cooling water; and a third circulating cooling water channel (26) for dissipating heat for the second wear-resistant ring plate via internal circulating cooling water.

8. The pressure relief sealing system for a slurry shield machine according to claim 1, characterized in that: The grease filling channel comprises: A first grease filling channel (22) disposed on the sealing body structure and communicating with the first grease chamber (21); A second grease filling channel (25) is provided on the sealing body structure and communicates with the second grease chamber (24).

9. The slurry shield machine pressure relief sealing system according to claim 1, characterized in that: The pressure relief channel (19) is connected to a pressure relief pump or a slurry discharge pump of the mud and water circulation system.

10. The pressure relief sealing system of a slurry shield machine according to any one of claims 1 to 9, characterized in that: Also includes: A pressure sensor is arranged in the pressure relief chamber (18).

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