Main drive seal system for a tunnel boring machine

Abstract

The invention relates to a main drive seal system for a drive shaft of a cutting wheel of a tunnel boring machine, comprising at least one pressurization and pressure-control system having at least one electronic controller (80) which comprises: at least one data storage unit; at least one data processing unit; and at least one control command output unit, the electronic controller (80) having a control program which, inter alia, has the following steps: calculating a pressure difference Δpi between the desired value pi-SOLL and the actual value pi-IST, i being the number of the chamber whose actual pressure is being controlled, and checking whether Δpi lies in a range x < 0 < y, x and y being a lower interval limit and an upper interval limit, wherein, if Δpi lies in the range x < 0 < y, the first compressed-air switching valve (21, 21', 31, 41) of the at least one chamber i (P2, P2', P3, P4) and the second compressed-air switching valve (22, 23, 22', 23', 32, 33, 42, 43) of the at least one chamber i (P2, P2', P3, P4) are controlled such that they are in the closed position, wherein, if Δpi is > y, the first compressed-air switching valve (21, 21', 31, 41) of the at least one chamber i (P2, P2', P3, P4) is controlled such that it switches to the open position and the second compressed-air switching valve (22, 23, 22', 23', 32, 33, 42, 43) of the at least one chamber i (P2, P2', P3, P4) is controlled such that it is in the closed position, and wherein, if Δpi is < x, the second compressed-air switching valve (22, 23, 22', 23', 32, 33, 42, 43) of the at least one chamber i (P2, P2', P3, P4) is controlled such that it switches to the open position and the first compressed-air switching valve (21, 21', 31, 41) of the at least one chamber i (P2, P2', P3, P4) is controlled such that it is in the closed position.

Description

[0001] MAIN DRIVE SEALING SYSTEM FOR A TUNNEL BORING MACHINE

[0002] Technical area

[0003] The present application relates to the technical field of tunnel boring machines, in particular to a fluid-supported or earth pressure-supported tunnel boring machine with a cutter wheel. Such tunnel boring machines, in particular, have a main drive shaft sealing system for the drive shaft of the cutter wheel.

[0004] In particular, the present application relates to a main drive sealing system for a drive shaft of a cutting wheel of a tunnel boring machine with at least one chamber with a first pressure behind a cutting wheel, comprising at least one first chamber with a first pressure, wherein the first chamber is preferably a labyrinth chamber filled with a barrier grease (HBW), at least one second chamber with a second pressure, wherein the at least one second chamber is an oil and compressed air sealing chamber, at least one seal between the at least one first chamber and the at least one second chamber, which can withstand a differential pressure ApL1 between the at least one first chamber and the at least one second chamber, at least one compressed air inlet connection, at least one compressed air outlet line,at least one first compressed air switching valve of the at least one second chamber having at least one compressed air inlet and at least one compressed air outlet, wherein the first compressed air switching valve of the at least one second chamber is configured to be switchable between an open and a closed position, at least one second compressed air switching valve of the at least one second chamber having at least one compressed air inlet and at least one compressed air outlet, wherein the second compressed air switching valve of the at least one second chamber is configured to be switchable between an open and a closed position, at least one inlet of the compressed air inlet connection configured to be pneumatically connected to a compressed air source, at least one outlet of the compressed air inlet connection,which is pneumatically connected via a compressed air line to the at least one compressed air inlet of the first compressed air switching valve of the at least one second chamber, wherein the at least one compressed air outlet of the first compressed air switching valve of the at least one second chamber is pneumatically connected to the at least one compressed air inlet of the second compressed air switching valve of the at least one second chamber and the at least one second chamber, and wherein a compressed air outlet of the second compressed air switching valve of the at least one second chamber is pneumatically connected to the compressed air discharge line, as well as a method for regulating the pressure in a main drive sealing system for a tunnel boring machine.

[0005] background

[0006] The construction of tunnels with large cross-sections, great laying depths, high water pressure and over long distances is accompanied by complex and harsh working conditions.

[0007] In conditions involving high water pressure, such as tunneling beneath a body of water such as a river or the sea, a slurry-supported or earth pressure-assisted tunnel boring machine should be used. Currently, a safe and reliable method is the use of an air-assisted tunnel boring machine.

[0008] The main drive is a critical part of a fluid-supported or earth pressure-supported tunnel boring machine. The sealing performance of the main drive directly determines the water and soil pressure bearing capacity of the tunnel boring machine. Currently, a sealing system consisting of rubber lip seals is used for the main drive of the tunnel boring machine. Typically, four sealing lips are provided. Outside the first sealing lip is a labyrinth chamber into which HBW grease is continuously injected as a loss lubrication to prevent the ingress of fluid or soil slurry from the outside. A grease chamber P1 is then provided, formed by the first and second sealing lips. This grease chamber is continuously filled with EP2 grease to loss. This further improves the sealing capacity of the main drive and lubricates sealing lips 1 and 2 to reduce wear.Next comes an oil and compressed air sealing chamber P2, formed by the second and third sealing lips. The oil is used to lubricate seals 2 and 3. When the pressure in the working chamber exceeds a certain value, gear oil and / or air are injected into this chamber to support the sealing lips. The third sealing lip and the fourth sealing lip are generally installed opposite each other to form a leakage detection chamber P3. The fourth sealing lip is primarily configured to seal a gearbox P4 to prevent the internal gear oil from leaking out.

[0009] The load-bearing capacity of a single rubber lip seal is generally about 3 bar. When the water and soil pressure are less than 3 bar, the external water and soil pressure in the excavation chamber can be absorbed by the grease pressure of the P1 grease chamber, ensuring reliable operation of the main drive seal.

[0010] When the water and soil pressure is greater than 3 bar and less than 6 bar, the total pressure provided by the oil and compressed air sealing chamber P2 and the grease chamber P1 as back pressure can also withstand the external water and soil pressure in the mining chamber.

[0011] A system for chamber 1 with HBW and chamber 2 with EP2 is disclosed in CN106223964B. This discloses a method for controlling a sealing pressure of a main bearing of a shield tunneling machine in the HBW chamber and the EP2 chamber of the sealing system. The HBW grease loss lubrication system includes a pneumatic HBW source 1 and an HBW grease injection port 16. The pneumatic HBW source 1 and the HBW grease injection port 16 are connected by the HBW supply line 2. An HBW supply pressure gauge 3, an HBW two-way solenoid valve 4, an HBW filter 5, a preset HBW proportional pressure reducing valve 6, and an HBW pressure sensor 7 are sequentially installed in the HBW supply line 2. The EP2 grease lubrication comprises a pneumatic EP2 source 8 and an EP2 grease injection port 17. The pneumatic EP2 source 8 and the EP2 grease injection port 17 are connected by the EP2 supply line 9.In the HBW supply line 9, an EP2 supply pressure gauge 10, an EP2 two-way solenoid valve 22, an EP2 filter 12, a preset EP2 proportional pressure reducing valve 13 and an HBW pressure sensor 14 as well as an EP2 multi-point lubrication pump 15 are installed one after the other.

[0012] The sealing pressure control procedure includes the steps:

[0013] 1. Input Ap1 and Ap2 into a control program of the tunnel boring machine, where Ap1 and Ap2 are not 0 and Ap1 > Ap2; Ap1 is the pressure difference between the pressure pO of the excavation chamber and the pressure p1 behind the preset HBW proportional pressure reducing valve 6, which is measured by the HBW pressure sensor 7, and Ap2 is the pressure difference between the pressure p2 behind the preset EP2 proportional pressure reducing valve 13, which is measured by the EP2 pressure sensor 14, and the pressure p1 behind the preset HBW proportional pressure reducing valve 6. 2. Detecting PO in the excavation chamber behind the cutting wheel;

[0014] 3. Adjusting the HBW pressure p1 in relation to the pressure pO of the mining chamber, where P1 = PO + Ap1.

[0015] 4. Setting the EP2 pressure p2 in relation to the HBW pressure p1 , where P2 = P1 - Ap2, Thus P2 also depends on PO.

[0016] The pre-set differential pressure control valves allow the discharge pressure in P1 and P2 to be adjusted depending on the tunnel boring machine's control system settings. This provides a closed-loop pressure control system through pressure feedback; this creates a relative pressure setting in the seal by linking the pressure pO of the excavation chamber, the pressure p1 of the HBW grease loss lubrication in the HWB chamber, and the pressure p2 of the EP2 grease lubrication in the EP2 chamber. The sealing capacity of this system ends at 6 bar.

[0017] In a case where the shield machine is operated at great depth and with high water pressure, the water and soil pressure exceeds 6 bar, so that the conventional multi-lip combined seal can hardly withstand the external water pressure, and soil slurry / bentonite slurry / drilling cuttings penetrate the seal and enter the main drive, resulting in the shield machine stoppage and the project delay.

[0018] CN207049619U and CN107401678A disclose a fully mechanical-pneumatic differential pressure control system for a sealing system of a main drive shaft of a tunnel boring machine for the chambers of the sealing system behind the HBW labyrinth seal and the EP2 grease lubrication chamber. This system allows the chambers of the sealing system located behind it to be mechanically and pneumatically pressurized in a differential pressure-controlled manner. It includes a compressed air source 1, a first pressure chamber 5 connected to the oil chamber P2 between the second and third lip seals of the sealing system, and a first mechanical-pneumatic differential pressure valve 3 between the compressed air source 1 and the first pressure chamber 5.Furthermore, a third mechanical-pneumatic differential pressure valve 8 is provided, which is arranged between the compressed air source 1 and a third pressure chamber 12, wherein the third pressure chamber 12 is a chamber between the oppositely arranged fourth lip seal and the gear chamber, which is provided here in an airtight manner. Furthermore, the third mechanical-pneumatic differential pressure valve 8 is connected, parallel to the connection to the third pressure chamber 12, to both a pressure relief valve 7 and a second mechanical-pneumatic differential pressure valve 2. The second mechanical-pneumatic differential pressure valve 2 is connected, opposite the connection to the third mechanical-pneumatic differential pressure valve 8, to a second pressure chamber 11, which is the leakage chamber P3 between the third and fourth lip seals.The pressure relief valve 7 is connected to a silencer 4 as a pneumatic drain opposite the connection to the third differential pressure valve 8. For pressure regulation, a drain throttle 9 is provided between each of the pressure chambers 5, 11, 12 and the mechanically pneumatic differential pressure valves 3, 8 and 2, which continuously release compressed air. The mechanically pneumatic differential pressure valves 3, 8 and 2 and the pressure relief valve 7 are each mechanically adjustable with a pressure difference value Ap, which is or can be different for each valve 2, 3, 7, 8. The pressure relief valve 7 serves as an overpressure drain for the third pressure chamber 12 / P4 and, if necessary, also for the second pressure chamber 11 / P3. Furthermore, a fourth pressure chamber 13 is provided, which represents the compressed air bladder 16 of the cutting wheel 14 of the tunnel boring machine and is connected to the excavation chamber 15 behind the cutting wheel 14.The pressure 22 of the liquid or soil slurry acts on the compressed air bladder in the fourth pressure chamber. The fourth pressure chamber thus serves as the reference pressure for regulating the sealing system.

[0019] The first differential pressure valve 3 is pneumatically connected at its + connection to the fourth pressure chamber 13 / 16 and at its - connection to the first pressure chamber 5 / P2. The second differential pressure valve 2 is pneumatically connected at its + connection to the first pressure chamber 5 / P2 and at its - connection to the second pressure chamber 11 / P3. The third differential pressure valve 8 is pneumatically connected at its + connection to the second pressure chamber 11 / P3 and at its - connection to the third pressure chamber 12 / P4. The pressure relief valve 7 is pneumatically connected at its + connection to the second pressure chamber 11 / P3 and at its - connection to the third pressure chamber 12 / P4. However, the Ap of the third differential pressure valve 8 and the pressure relief valve 7 are different.

[0020] By mechanically adjusting the pressure differential values ​​of the first differential pressure valve 3, the second differential pressure valve 2, the third differential pressure valve 8, and the pressure relief valve 7, the corresponding pressure in the respective pressure chamber is regulated by the respective differential pressure valve and the throttle 9 in the event of a pressure change in the fourth reference pressure vessel 13 / 16. The flow valve is dynamically balanced to ensure that the pressure in each pressure chamber can be regulated and maintained according to the pressure differential values ​​to maintain the pressure differences in the pressure chambers. The pressure relief valve can provide dynamic protection in the event of system overpressure to maintain system stability.

[0021] EP3854990 discloses a solution for a main drive sealing system for a tunnel boring machine, which has a mechanical-pneumatic feedback and follow-up control. The tunnel boring machine has a cutter wheel. The space behind the cutter wheel is fluidly connected to a compressed air bladder in a compressed air chamber ACB. The main drive sealing system comprises an HBW labyrinth seal PO, a grease chamber P1, an oil and compressed air seal chamber P2, a leak detection chamber P3, and a gear chamber P4. The chambers P1, P2, P3, and P4 are separated from each other by lip seals. The chambers P2, P3, and P4 can be pressurized by introducing compressed air via compressed air lines. A compressed air inlet connection is provided for this purpose. To achieve pressure control, mechanical-pneumatic differential pressure control valves 21, 22, 23 are provided in the compressed air lines. An exhaust air line is also provided.The exhaust air line is connected to the chambers P2, P3, P4 via mechanical pneumatic differential pressure control valves 51, 52, 53 in order to release pressure from the chambers in a controlled manner.

[0022] When the pressure difference between the compressed air chamber ACB and the oil and compressed air seal chamber P2 is greater than or equal to a first preset value, the first positive pneumatic differential pressure regulating valve 21 is opened, and the first negative pneumatic differential pressure regulating valve 51 is in a closed state ("in a closed state" means that the valve element is closed at this time or has been closed in advance, the same applies hereinafter); and when the pressure difference between the compressed air chamber and the oil and compressed air seal chamber P2 is less than or equal to a second preset value, the first negative pneumatic differential pressure regulating valve 51 is opened, and the first positive pneumatic differential pressure regulating valve 21 is in a closed state.

[0023] The "first preset value" is set according to the minimum opening value preset in the first positive pneumatic differential pressure control valve 21 (i.e., the first positive pneumatic differential pressure control valve 21 is opened and released when the pressure difference reaches or exceeds this value) and the minimum closing value preset in the first negative pneumatic differential pressure control valve 51 (i.e., the first negative pneumatic differential pressure control valve 51 is closed and sealed when the pressure difference reaches or exceeds this value). Preferably, the first preset value corresponds to the minimum opening value of the first positive pneumatic differential pressure control valve 21 and is greater than or equal to the minimum closing value of the first negative pneumatic differential pressure control valve 51.

[0024] The "second preset value" is set according to the maximum closing value preset in the first positive pneumatic differential pressure control valve 21 (i.e., the first positive pneumatic differential pressure control valve 21 is closed and blocked when the pressure difference reaches or falls below this value) and the maximum opening value preset in the first negative pneumatic differential pressure control valve 51 (i.e., the first negative pneumatic differential pressure control valve 51 is opened and blocked when the pressure difference reaches or falls below this value). Preferably, the second preset value corresponds to the maximum opening value of the first negative pneumatic differential pressure control valve 51 and is less than or equal to the maximum closing value of the first positive pneumatic differential pressure control valve 21.

[0025] Therefore, when the pressure difference between the compressed air chamber ACB and the oil and compressed air seal chamber P2 increases to or exceeds the first preset value, the first positive pneumatic differential pressure regulating valve 21 is opened, and the first negative pneumatic differential pressure regulating valve 51 is closed, and compressed air is charged into the oil and compressed air seal chamber P2 (ie, the oil and compressed air seal reservoir 11) after passing through the compressed air inlet port and the first positive pneumatic differential pressure regulating valve 21. The oil and compressed air seal chamber P2 is continuously filled until the total pressure of the oil and compressed air seal chamber P2 and the grease chamber P1 can balance the external water and soil pressure, so that the main drive seal can reliably hold.and preferably, at this time, the pressure difference between the compressed air chamber ACB and the oil and compressed air seal chamber P2 reaches or is less than an intermediate value (which is less than the first preset value and less than or equal to the rated pressure of the grease chamber P1) preset in the first positive pneumatic differential pressure regulating valve 21, and the first positive pneumatic differential pressure regulating valve 21 is closed (or, in other specific embodiments, the first positive pneumatic differential pressure regulating valve 21 may still be in an open state in which the discharge capacity of the first positive pneumatic differential pressure regulating valve is small to compensate for the leakage). When the pressure in the compressed air chamber ACB decreases, when the pressure difference between the compressed air chamber ACB and the oil and compressed air seal chamber P2 is less than or equal to the second preset value,The first negative pneumatic differential pressure control valve 51 is opened and the first positive pneumatic differential pressure control valve 21 is closed. At this time, the compressed air in the oil and compressed air seal chamber P2 is discharged through the first negative pneumatic differential pressure control valve 51; and the compressed air in the oil and compressed air seal chamber P2 is continuously discharged until the pressure difference between the compressed air chamber ACB and the oil and compressed air seal chamber P2 reaches an intermediate value (greater than the second preset value) set in the first negative pneumatic differential pressure control valve 51, and the first negative pneumatic differential pressure control valve 51 is closed.

[0026] Furthermore, a compressed air path of the main drive sealing system is disclosed, which includes the oil and compressed air sealing chamber P2, a gear P4, a second positive pneumatic differential pressure control valve 22, and a second negative pneumatic differential pressure control valve 52. When the pressure difference between the oil and compressed air sealing chamber P2 and the gear P4 is greater than or equal to a third preset value, the second positive pneumatic differential pressure control valve 22 is opened and the second negative pneumatic differential pressure control valve 52 is closed; and when the pressure difference between the oil and compressed air sealing chamber P2 and the gear P4 is less than or equal to a fourth preset value, the second negative pneumatic differential pressure control valve 52 is opened and the second positive pneumatic differential pressure control valve 22 is closed.

[0027] The "third preset value" is set according to the minimum opening value preset in the second positive pneumatic differential pressure control valve 22 (i.e., the second positive pneumatic differential pressure control valve 22 opens and releases when the pressure difference reaches or exceeds this value) and the minimum closing value preset in the second negative pneumatic differential pressure control valve 52 (i.e., the second negative pneumatic differential pressure control valve 52 closes and seals when the pressure difference reaches or exceeds this value). Preferably, the third preset value corresponds to the minimum opening value of the second positive pneumatic differential pressure control valve 22 and is greater than or equal to the minimum closing value of the second negative pneumatic differential pressure control valve 52.

[0028] The "fourth preset value" is set according to the maximum closing value preset in the second positive pneumatic differential pressure control valve 22 (i.e., the second positive pneumatic control valve 22 is closed and blocked when the pressure difference reaches or falls below this value) and the maximum opening value preset in the second negative pneumatic differential pressure control valve 52 (i.e., the second negative pneumatic differential pressure control valve 52 is opened and blocked when the pressure difference reaches or falls below this value). Preferably, the fourth preset value corresponds to the maximum opening value of the second negative pneumatic differential pressure control valve 52 and is less than or equal to the maximum closing value of the second positive pneumatic differential pressure control valve 22.In order to prevent leakage of the gear oil in the gearbox due to overpressure, when the pressure difference between the oil and compressed air sealing chamber P2 and the gearbox P4 is greater than the third preset value, the second positive pneumatic differential pressure regulating valve 22 is opened and the second negative pneumatic differential pressure regulating valve 52 is in a closed state, and the compressed air is charged into the gearbox P4 after passing through the compressed air inlet and the second positive pneumatic differential pressure regulating valve 22 to charge the gearbox.The transmission P4 is continuously charged until the pressure difference between the oil and compressed air seal chamber P2 and the transmission P4 reaches or falls below an intermediate value (which is smaller than the third preset value) preset in the second positive pneumatic differential pressure control valve 22, and at this time, the second positive pneumatic differential pressure control valve 22 is closed (or, in other specific embodiments, the second positive pneumatic differential pressure control valve 22 may still be in an open state in which the discharge capacity of the second positive pneumatic control valve is small to compensate for leakage).When the pressure in the compressed air chamber ACB drops, the pressure in the oil and compressed air seal chamber P2 also drops. When the pressure difference between the oil and compressed air seal chamber P2 and the gear box P4 is less than or equal to the fourth preset value, the second negative pneumatic differential pressure regulating valve 52 opens and the second positive pneumatic differential pressure regulating valve 52 closes. At this time, the compressed air in the gear box P4 is discharged through the second negative pneumatic differential pressure regulating valve 52. The compressed air in the gear box P4 is continuously discharged until the pressure difference between the oil and compressed air seal chamber P2 and the gear box P4 reaches an intermediate value (greater than the fourth preset value) set in the second negative pneumatic differential pressure regulating valve 52, and the second negative pneumatic differential pressure regulating valve 52 closes.

[0029] Furthermore, a compressed air path of the main drive sealing system is disclosed, which includes the gear P4, a leak detection chamber P3, a third positive pneumatic differential pressure control valve 23, and a third negative pneumatic differential pressure control valve 53. When the pressure difference between the gear P4 and the leak detection chamber P3 is greater than or equal to a fifth preset value, the third positive pneumatic differential pressure control valve 23 is opened and the third negative pneumatic differential pressure control valve 53 is in a closed state; and when the pressure difference between the gear P4 and the leak detection chamber P3 is less than or equal to a sixth preset value, the third negative pneumatic control valve 53 is opened and the third positive pneumatic control valve 23 is in a closed state.

[0030] The "fifth preset value" is set according to the minimum opening value preset in the third positive pneumatic differential pressure control valve 23 (i.e., the third positive pneumatic differential pressure control valve 23 opens and releases when the pressure difference reaches or exceeds this value) and the minimum closing value preset in the third negative pneumatic differential pressure control valve 53 (i.e., the third negative pneumatic differential pressure control valve 53 closes and seals when the pressure difference reaches or exceeds this value). Preferably, the fifth preset value corresponds to the minimum opening value of the third positive pneumatic differential pressure control valve 23 and is greater than or equal to the minimum closing value of the third negative pneumatic differential pressure control valve 53.

[0031] The "sixth preset value" is set according to the maximum closing value preset in the third positive pneumatic differential pressure control valve 23 (i.e., the third positive pneumatic differential pressure control valve 23 is closed and blocked when the pressure difference reaches or falls below this value) and the maximum opening value preset in the third negative pneumatic control valve 53 (i.e., the third negative pneumatic control valve 53 is opened and blocked when the pressure difference reaches or falls below this value). Preferably, the sixth preset value corresponds to the maximum opening value of the third negative pneumatic differential pressure control valve 53 and is less than or equal to the maximum closing value of the third positive pneumatic differential pressure control valve 23.

[0032] When the pressure difference between the gearbox P4 and the leakage detection chamber P3 is greater than or equal to the fifth preset value, the third positive pneumatic differential pressure regulating valve 23 is opened, and the third negative pneumatic differential pressure regulating valve 53 is in a closed state, and the compressed air is charged into the leakage detection chamber P3 after passing through the compressed air inlet port, the second positive pneumatic differential pressure regulating valve 22 and the third positive pneumatic differential pressure regulating valve 23.The leakage detection chamber P3 is continuously pressurized until the total pressure of the leakage detection chamber P3, the oil and compressed air seal chamber P2, and the EP2 grease chamber P1 can balance the external water and ground pressure, so that the main drive seal is reliable, preferably at this time, the pressure difference between the gear P4 and the leakage detection chamber P3 reaches or is smaller than an intermediate value (which is smaller than the fifth preset value) preset in the third positive pneumatic differential pressure regulating valve 23, and the third positive pneumatic differential pressure regulating valve 23 is closed (or, in other specific embodiments, the third positive pneumatic regulating valve 23 may still be in an open state in which the discharge capacity of the third positive pneumatic differential pressure regulating valve is small) to compensate for the leakage.When the pressure in the compressed air chamber ACB drops, the pressure in the leakage detection chamber P3 also drops. When the pressure difference between the gearbox P4 and the leakage detection chamber P3 is less than or equal to the sixth preset value, the third negative pneumatic differential pressure regulating valve 53 opens, and the third positive pneumatic differential pressure regulating valve 53 is closed. At this time, the compressed air in the leakage detection chamber P3 is discharged through the third pneumatic differential pressure regulating valve 53. The compressed air in the leakage detection chamber P3 is continuously discharged until the pressure difference between the gearbox P4 and the leakage detection chamber P3 reaches an intermediate value (greater than the sixth preset value) set in the third negative pneumatic differential pressure regulating valve 53, and the third negative pneumatic differential pressure regulating valve 53 is closed.

[0033] TASK

[0034] The previously described mechanical-pneumatic differential pressure control systems are very complex to install, adjust, and repair. There is a very high risk of errors during installation, which can then lead to damage that is expensive to repair. Furthermore, the systems are complex to adapt to seal wear and changing parameters. Furthermore, the sealing systems exhibit problems in the area of ​​the rear sealing chambers if they are not pressurized due to the system's design. This can easily lead to seal malfunctions, which can then lead to oil leaks from one chamber to the adjacent chamber.

[0035] The object of the invention is to provide a main drive sealing system for a tunnel boring machine which overcomes the aforementioned disadvantages.

[0036] DESCRIPTION OF THE INVENTION

[0037] This object is achieved according to the invention in that at least one electronic controller is provided, which has at least one data storage unit, at least one data processing unit and at least one control command output unit, that at least one control circuit based on the at least one electronic controller is provided for regulating the second pressure in the at least one second chamber, that at least one first pressure detection device is connected to the at least one space or the at least one first chamber in order to measure the pressure in the space or the current pressure in the at least one first chamber, wherein the at least one first pressure detection device is electronically connected to the at least one electronic controller for transmitting the pressure, that at least one second pressure detection device is connected to the at least one second chamber,to measure the current pressure in the at least one second chamber, wherein the at least one second pressure sensing device is electronically connected to the at least one electronic controller for transmitting the pressure, that the at least one first compressed air switching valve of the at least one second chamber is connected to the at least one control device so that the at least one first compressed air switching valve of the at least one second chamber can be electrically switched by the control device, that the at least one second compressed air switching valve of the at least one second chamber is connected to the at least one control device so that the at least one second compressed air switching valve of the at least one second chamber can be electrically switched by the control device, and that the electronic controller has a control program with the following steps:

[0038] Receiving and storing the pressure pO and / or the pressure p1 -IST,

[0039] Determining and storing the differential pressure ApL1-CONTROL, wherein preferably a check step is provided that the ApL1-CONTROL is less than or equal to the pressure difference ApL1;

[0040] Setting and storing a pressure surcharge Ap1 and calculating a pressure p1-SOLL according to the formula p1-SOLL= p0+ Ap1 , wherein preferably a check step is provided that p1-SOLL is greater than p0,

[0041] Setting a reference pressure pREF, where pREF is one of the following pressures: p0+ Ap1 or p1-IST,

[0042] Memory of the pressure p2-IST,

[0043] Calculating a pressure p2-SOLL according to the formula p2-SOLL = pREF - ApL1- CONTROL, whereby a check step is provided that p2-SOLL lies in a range between pREF and pREF- ApL1,

[0044] Receiving and storing the pressure p2-IST of the second chamber,

[0045] Calculate and store a pressure difference Ap2 between p2-TARGET and p2-ACTUAL, and

[0046] Check if Ap2 in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap2 in dem Bereich x<0< y liegt, das erste Druckluftschaltventil der wenigstens einen zweiten Kammer und das zweite Druckluftschaltventil der wenigstens einen zweiten Kammer so von der Steuerung so angesteuert sind, dass das erste Druckluftschaltventil und das zweite Druckluftschaltventil geschlossen sind, wobei, wenn Ap2 > y, the control command output unit sends a signal for opening the first compressed air switching valve of the at least one second chamber to the first compressed air switching valve of the at least one second chamber, wherein the second compressed air switching valve of the at least one second chamber is controlled so that it is closed, and wherein, if Ap2 < x,the control command output unit sends a signal for opening the second compressed air switching valve of the at least one second chamber to the second compressed air switching valve of the at least one second chamber, wherein the first compressed air switching valve of the at least one second chamber is controlled so that it is closed.

[0047] The advantage here is that, despite the reservations of experts that only mechanically pneumatic differential pressure systems are safe, the system according to the invention is cost-effective and space-saving to install and can be easily and error-free assembled, adjusted, maintained and adapted, even by means of a corresponding simple adjustment in the control program.

[0048] The interval limits x, y are switching conditions for the respective first and second compressed air switching valves belonging to the chambers P2, P2', P3, P4. The expert will understand the interval limits x, y as an upper and a lower limit for the pressure differences Ap2, as well as the pressure differences Ap2', Ap3, Ap4 described below as sensible limit values ​​for maintaining the respective desired pressure conditions in the chambers P2, P2', P3, P4, if necessary also depending on the pressure pO in the excavation chamber, x, y lie in ranges from -1 to +1 bar, -0.5 to +0.5 bar, -0.25 to +0.25 bar, -0.1 to +0.1 bar, -0.05 to +0.05 bar, -0.025 to +0.025 bar, -0.01 to +0.01 bar, or smaller - / + pressures. These serve to clarify that x, y are merely values ​​to be set in the control system depending on the respective components of the main drive sealing system and the pressure conditions in which it is used.

[0049] A further solution of the invention provides that at least one further second chamber with a further second pressure is provided following the at least one second chamber, wherein the at least one further second chamber is an oil and compressed air sealing chamber, that at least one seal is provided between the at least one second chamber and the at least one further second chamber, which can withstand a differential pressure ApL2 between the at least one second chamber and the at least one further second chamber, that at least one first compressed air switching valve of the at least one further second chamber is provided with at least one compressed air inlet and at least one compressed air outlet, wherein the first compressed air switching valve of the at least one further second chamber is designed such that it can be switched between an open and a closed position,that at least one second compressed air switching valve of the at least one further second chamber is provided with at least one compressed air inlet and at least one compressed air outlet, wherein the second compressed air switching valve of the at least one further second chamber is configured such that it can be switched between an open and a closed position, that at least one control circuit based on the at least one electronic control is provided for regulating the further second pressure in the at least one further second chamber, that at least one further second pressure sensing device is connected to the at least one further second chamber in order to measure the current pressure in the at least one second chamber, wherein the at least one further second pressure sensing device is electronically connected to the at least one electronic control for transmitting the pressure,that the at least one first compressed air switching valve of the at least one further second chamber is connected to the at least one control device, so that the at least one first compressed air switching valve of the at least one further second chamber can be electrically switched by the control device, that the at least one second compressed air switching valve of the at least one further second chamber is connected to the at least one control device, so that the at least one second compressed air switching valve of the at least one further second chamber can be electrically switched by the control device, that the at least one outlet of the compressed air inlet connection, which is pneumatically connected via a compressed air line to the at least one compressed air inlet of the first compressed air switching valve of the at least one further second chamber,wherein the at least one compressed air outlet of the first compressed air switching valve of the at least one further second chamber is pneumatically connected to the at least one compressed air inlet of the second compressed air switching valve of the at least one further second chamber and the at least one further second chamber, and wherein a compressed air outlet of the second compressed air switching valve of the at least one further second chamber is pneumatically connected to the compressed air discharge line, and that the control program of the electronic control has the following further steps:

[0050] Setting and storing the differential pressure ApL2-CONTROL, with a check step being provided that the ApL2-CONTROL is less than or equal to the pressure difference ApL2;

[0051] Receiving and storing the pressure p2'-IST of the further second chamber,

[0052] Calculating and storing a pressure p2'-TARGET according to the formula p2'-TARGET = p2-ACTUAL - ApL2-CONTROL or according to the formula p2'-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL, whereby a check step is provided that p2'-TARGET lies in a range between p2-ACTUAL and p2-ACTUAL - ApL2,

[0053] Calculate and save a pressure difference Ap2' between p2'-TARGET and p2'-ACTUAL, and check whether Ap2'in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap2‘ in dem Bereich x<0<y liegt, das erste Druckluftschaltventil der wenigstens einen weiteren zweiten Kammer und das zweite Druckluftschaltventil der wenigstens einen weiteren zweiten Kammer so angesteuert sind, dass sie geschlossen sind, wobei, wenn Ap2‘ > y, the control command output unit sends a signal for opening the first compressed air switching valve of the at least one further second chamber to the first compressed air switching valve of the at least one further second chamber, wherein the second compressed air switching valve of the at least one further second chamber is controlled such that it is closed, and wherein, if Ap2' < x,the control command output unit sends a signal for opening the second compressed air switching valve of the at least one further second chamber to the second compressed air switching valve of the at least one further second chamber, wherein the first compressed air switching valve of the at least one further second chamber is controlled such that it is closed.

[0054] The provision of the additional second chamber, which is also designed as an oil and compressed air sealing chamber, has the advantage of providing an additional sealing stage compared to previous systems with EP2 grease lubrication chamber, which is also relevant for pressure dissipation.

[0055] A further solution of the invention provides that at least one third chamber with a third pressure is provided following the at least one second chamber or the at least one further second chamber, wherein the at least one third chamber is a leakage detection chamber, that at least one seal is provided between the at least one second chamber or that at least one seal is provided between the at least one further second chamber and the at least one third chamber, which can withstand a differential pressure ApL2 between the at least one second chamber or which can withstand a differential pressure ApL2' between the at least one further second chamber and the at least one third chamber, that at least one first compressed air switching valve of the at least one third chamber is provided with at least one compressed air inlet and at least one compressed air outlet,wherein the first compressed air switching valve of the at least one third chamber is configured such that it can be switched between an open and a closed position, that at least one second compressed air switching valve of the at least one third chamber is provided with at least one compressed air inlet and at least one compressed air outlet, wherein the second compressed air switching valve of the at least one third chamber is configured such that it can be switched between an open and a closed position, that at least one control circuit based on the at least one electronic control is provided for regulating the third pressure in the at least one third chamber, that at least one third pressure sensing device is connected to the at least one third chamber in order to measure the current pressure in the at least one third chamber,wherein the at least one third pressure detection device is electronically connected to the at least one electronic controller for transmitting the pressure, that the at least one first compressed air switching valve of the at least one third chamber is connected to the at least one control device such that the at least one first compressed air switching valve can be electrically switched by the control device, that the at least one second compressed air switching valve of the at least one third chamber is connected to the at least one control device such that the at least one second of the at least one third chamber can be electrically switched by the control device, that the at least one outlet of the compressed air inlet connection, which is pneumatically connected via a compressed air line to the at least one compressed air inlet of the first compressed air switching valve of the at least one third chamber,wherein the at least one compressed air outlet of the first compressed air switching valve of the at least one third chamber is pneumatically connected to the at least one compressed air inlet of the second compressed air switching valve of the at least one third chamber and the at least one third chamber, and wherein a compressed air outlet of the second compressed air switching valve of the at least one third chamber is pneumatically connected to the compressed air discharge line, and that the control program of the electronic control further comprises the following steps:

[0056] Setting and storing the differential pressure ApL2-CONTROL or the differential pressure ApL2'-CONTROL, wherein a check step is provided that the differential pressure ApL2-CONTROL is less than or equal to the pressure difference ApL2, or that the differential pressure ApL2'-CONTROL is less than or equal to the pressure difference ApL2';

[0057] Receiving and storing the pressure p3-IST of the third chamber,

[0058] Calculating and storing a pressure p3-TARGET according to the formula p3-TARGET = (p2-ACTUAL or p2'-ACTUAL) - (ApL2-CONTROL or ApL2'-CONTROL) or according to the formula p3-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL - ApL2'-CONTROL, whereby a check step is provided in each case to ensure that p3-TARGET lies in a range between p2-ACTUAL and p2-ACTUAL - ApL2 or between p2'-ACTUAL and p2'-ACTUAL - ApL2,

[0059] Calculate and store a pressure difference Ap3 between p3-TARGET and p3-ACTUAL, and

[0060] Check if Ap3 in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap3 in dem Bereich x<0<y liegt, das erste Druckluftschaltventil der wenigstens einen dritten Kammer und das zweite Druckluftschaltventil der wenigstens einen dritten Kammer so angesteuert sind, dass sie geschlossen sind, wobei, wenn Ap3 > y, the control command output unit sends a signal for opening the first compressed air switching valve of the at least one third chamber to the first compressed air switching valve of the at least one third chamber, wherein the second compressed air switching valve of the at least one third chamber is controlled so that it is closed, and wherein, if Ap3 < x, the control command output unit sends a signal for opening the second compressed air switching valve of the at least one third chamber to the second compressed air switching valve of the at least one third chamber,wherein the first compressed air switching valve of the at least one third chamber is controlled so that it is closed.,

[0061] This provides easy control of the pressure in the leak detection chamber.

[0062] A further solution of the invention provides that at least one fourth chamber with a fourth pressure is provided following the at least one third chamber, wherein the at least one fourth chamber is a gear chamber, that at least one seal is provided between the at least one third chamber and the at least one fourth chamber, which seal can withstand a differential pressure ApL3 between the at least one third chamber and that of the at least one fourth chamber, that at least one first compressed air switching valve of the at least one fourth chamber is provided with at least one compressed air inlet and at least one compressed air outlet, wherein the first compressed air switching valve of the at least one fourth chamber is designed such that it can be switched between an open and a closed position,that at least one second compressed air switching valve of the at least one fourth chamber is provided with at least one compressed air inlet and at least one compressed air outlet, wherein the second compressed air switching valve of the at least one fourth chamber is configured such that it can be switched between an open and a closed position, that at least one control circuit based on the at least one electronic controller is provided for regulating the fourth pressure in the at least one fourth chamber, that at least one third pressure sensing device is connected to the at least one fourth chamber in order to measure the current pressure in the at least one third chamber, wherein the at least one fourth pressure sensing device is electronically connected to the at least one electronic controller for transmitting the pressure,that the at least one first compressed air switching valve of the at least one fourth chamber is connected to the at least one control device, so that the at least one first compressed air switching valve of the at least one fourth chamber can be electrically switched by the control device, that the at least one second compressed air switching valve of the at least one fourth chamber is connected to the at least one control device, so that the at least one second compressed air switching valve of the at least one fourth chamber can be electrically switched by the control device, that the at least one outlet of the compressed air inlet connection, which is pneumatically connected via a compressed air line to the at least one compressed air inlet of the first compressed air switching valve of the at least one fourth chamber,wherein the at least one compressed air outlet of the first compressed air switching valve of the at least one fourth chamber is pneumatically connected to the at least one compressed air inlet of the second compressed air switching valve of the at least one fourth chamber and the at least one fourth chamber, and wherein a compressed air outlet of the second compressed air switching valve of the at least one fourth chamber is pneumatically connected to the compressed air discharge line, and that the control program of the electronic control has the following further steps:

[0063] Setting and saving a print surcharge Ap4SUSCHLAG,

[0064] Calculate and save a pressure p4-TARGET according to the formula p4-TARGET = p3-ACTUAL+ Ap4ADD,

[0065] Setting and storing the differential pressure ApL3-CONTROL, with a check step being provided that the ApL3-CONTROL is less than or equal to the pressure difference ApL3;

[0066] Receiving and storing the pressure p4-IST of the fourth chamber,

[0067] Calculate and store a pressure difference Ap4 between p4-TARGET and p4-ACTUAL, and

[0068] Check if Ap4 in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap4 in dem Bereich x<0<y liegt, das erste Druckluftschaltventil der wenigstens einen vierten Kammer und das zweite Druckluftschaltventil der wenigstens einen vierten Kammer so angesteuert sind, dass sie geschlossen sind, wobei, wenn Ap4 > y, the control command output unit sends a signal for opening the first compressed air switching valve of the at least one fourth chamber to the first compressed air switching valve of the at least one fourth chamber, wherein the second compressed air switching valve of the at least one fourth chamber is controlled so that it is closed, and wherein, if Ap4 < x, the control command output unit sends a signal for opening the second compressed air switching valve of the at least one fourth chamber to the second compressed air switching valve of the at least one fourth chamber,wherein the first compressed air switching valve of the at least one fourth chamber is controlled so that it is closed.,

[0069] This provides simple regulation of the pressure in the gear chamber. A further solution of the invention provides that the at least one compressed air outlet of the second compressed air switching valve of the at least one second chamber, the at least one further second chamber, the at least one third chamber and / or the at least one fourth chamber is pneumatically connected to the compressed air discharge line, which is preferably connected to the environment via a silencer, and / or is pneumatically connected to an air extraction line, which is connected to a vacuum pump, wherein the vacuum pump is preferably controllable via the controller. By using the two variants of compressed air delivery, either passively or actively as extraction, it is possible to release the pressure in one or more of the chambers in a targeted manner and with the desired precision.

[0070] A further solution of the invention provides that at least one of the chambers is connected to at least one third compressed air switching valve, which is pneumatically connected with its compressed air outlet to an air extraction line that is connected to a vacuum pump, so that a pressure less than atmospheric pressure can be set in the connected chamber, wherein the vacuum pump is preferably controllable via the controller. The third compressed air switching valve thus enables a second way of reducing the pressure. The reduction is carried out in a controlled manner by the vacuum pump. It has also surprisingly been found that this makes it possible to provide a pressure in one or more chambers that is less than atmospheric pressure. It has surprisingly been found that this can increase the sealing effect in the chambers by sucking the seal onto the shaft to be sealed.

[0071] A further solution of the invention provides that a series of target pressures of the chambers is stored in the control system: pO < p1-TARGET > p2-TARGET > p2'-TARGET > p3-TARGET < p4-TARGET, whereby the additional second chamber and its pressure can be omitted. This prevents lubricant loss, which simplifies operation and makes it more cost-effective and environmentally friendly.

[0072] A further solution of the invention provides that if the target pressure is calculated to be less than atmospheric pressure in at least one of the chambers, the target pressure is set in the control system to atmospheric pressure or to a defined value between 0 bar and atmospheric pressure, which can then be adjusted by switching the third compressed air switching valve of the respective chamber by the control system, the air extraction line and the vacuum pump, wherein the vacuum pump is preferably controllable via the control system. It has surprisingly been found that this makes it possible to provide a pressure in one or more chambers that is less than atmospheric pressure. It has surprisingly been found that this can increase the sealing effect in the chambers by suctioning the seal onto the shaft to be sealed.

[0073] A further solution of the invention provides that, if pO + Ap1 is smaller than ApL1-CONTROL, the target pressures of the chambers in the control system are set to atmospheric pressure or at least one of the target pressures of the chambers in the control system is set to a defined value between 0 bar and atmospheric pressure, which can then be adjusted by switching the third compressed air switching valve of the respective chamber by the control system, the air extraction line and the vacuum pump, wherein preferably the vacuum pump is controllable via the control system.

[0074] A further solution of the invention provides that for at least one of the chambers a circulation pump is provided for the oil located in the chamber, which is fluidly connected via at least one line to at least one suction point of the chamber for sucking the oil out of the chamber and via at least one further line to at least one introduction point of the chamber for introducing the oil into the chamber. It is advantageous if the oil is filtered before or after the circulation pump, or if foreign substances are separated from the oil and / or the quality of the oil is checked. The circulation of the oil in the respective chamber enables a better supply of lubricant in the chamber. Furthermore, it has been shown that this easily achieves better lubrication of the seal(s) of the chambers, particularly in the upper area of ​​the seal.

[0075] A further solution of the invention provides that the air extraction line is connected to at least one vacuum reservoir, which is preferably connected to a pressure sensing device. This makes it easy to dampen the potentially pulsating effect of the vacuum pump and simultaneously temporarily extract air to equalize the pressure without activating the vacuum pump.

[0076] It is also advantageous that the actual pressure p2 of chamber P2 to be regulated is less than or equal to the pressure p1-ACTUAL of chamber P1, that the actual pressure p2' of chamber P2' to be regulated is less than or equal to the pressure p2-ACTUAL of chamber P2, and that the actual pressure p3 of chamber P3 to be regulated is less than or equal to the pressure p2-ACTUAL of chamber P2 or p2'-ACTUAL of chamber P2' and less than or equal to the pressure p4-ACTUAL of chamber P4. This simply prevents the lip seal to the adjacent chamber from opening and a medium in the chamber to be regulated, such as oil, from passing through the respective seal into the adjacent chamber.It is also advantageous that the actual pressure p2 of chamber P2 to be regulated is greater than or equal to the pressure p1-ACTUAL of chamber P1 - the pressure difference ApL1 of the lip seal L1, that the actual pressure p2' of chamber P2' to be regulated is greater than or equal to the pressure p2-ACTUAL of chamber P2 - the pressure difference ApL2' of the lip seal L2', and that the actual pressure p3 of chamber P3 to be regulated is greater than or equal to (the pressure p2-ACTUAL of chamber P2 or p2'-ACTUAL of chamber P2') - (the pressure difference ApL1 of the lip seal L1 or the pressure difference ApL2' of the lip seal L2') and greater than or equal to the pressure p4-ACTUAL of chamber P4 - the pressure difference ApL3 of the lip seal L3. that the lip seal fails because the pressure difference between two chambers is greater than the pressure difference that the lip seal can handle and the seal is therefore damaged.

[0077] Furthermore, the object of the invention is achieved by a method for regulating the pressure in a main drive sealing system in a main drive sealing system for a drive shaft of a cutting wheel of a tunnel boring machine, in particular according to one of the features described above, with at least one chamber PO with a first pressure pO behind a cutting wheel of the tunnel boring machine, wherein the chamber PO is connected to a pressure detection device, and wherein the main drive sealing system has the following features: at least one first chamber P1 with a first pressure p1, wherein the first chamber P1 is preferably a labyrinth chamber filled with a barrier grease (HBW), wherein the first chamber P1 is connected to a pressure detection device, at least one second chamber P2 with a second pressure p2, wherein the at least one second chamber P2 is an oil and compressed air sealing chamber P2,wherein the second chamber P2 is connected to a pressure sensing device, preferably at least one further second chamber P2' with a further second pressure p2', wherein the at least one further second chamber P2' is an oil and compressed air sealing chamber P2', wherein the further second chamber P2' is connected to a pressure sensing device, at least one third chamber P3 with a third pressure p3, wherein the at least one third chamber P3 is a leakage detection chamber, wherein the third chamber P3 is connected to a pressure sensing device, at least one fourth chamber P4 with a fourth pressure p4, wherein the at least one fourth chamber P4 is a transmission chamber, wherein the fourth chamber P4 is connected to a pressure sensing device, in each case at least one lip seal L1, L2, L2', L3 between the chambers P1, P2, P2', P3, P4, each of which is subjected to a differential pressure ApL1, ApL2, ApL2',ApL3 between the adjacent chambers, and at least one electronic control unit having at least one data storage unit, at least one data processing unit and at least one control command output unit, wherein at least one program for providing a control loop based on the at least one electronic control unit for the pressure p2-IST, p2'-IST, p3-IST, p4-IST to be controlled is executed in the control unit, with the method steps:

[0078] Measuring, receiving and storing the pressure pO and / or the pressure p1 -IST,

[0079] Setting and storing a pressure surcharge Ap1 and calculating a pressure p1-SOLL according to the formula p1-SOLL= p0+ Ap1 , wherein preferably a check step is provided that p1-SOLL is greater than p0,

[0080] Calculating a reference pressure pREF, where the reference pressure is the pressure pO in the first space PO + pressure surcharge Ap1 or the pressure p1-IST in the first chamber P1,

[0081] Measuring and receiving at least one actual pressure p2-IST, p2'-IST, p3-IST, p4-IST to be controlled;

[0082] Setting a differential pressure of at least one lip seal ApL1-CONTROL, ApL2-CONTROL, ApL2'-CONTROL, ApL3-CONTROL,

[0083] Setting and saving a pressure surcharge Ap4SUBSTITUTION between the third and fourth chambers P3, P4,

[0084] Calculate a target pressure p2-TARGET, p2'-TARGET, p3-TARGET, p4-TARGET using at least one of the following formulas: 1. p2-TARGET = pREF - ApL1-CONTROL 2. p2'-TARGET = p2-ACTUAL - ApL2-CONTROL or p2'-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL, 3. p3-TARGET = (p2-ACTUAL or p2'-ACTUAL) - (ApL2-CONTROL or ApL2'-CONTROL) or p3-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL - ApL2'-CONTROL, and 4. p4-TARGET = p3-ACTUAL + Ap4ADD or p4-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL - ApL2L2'- CONTROL + Ap4 SURCHARGE,

[0085] Calculate a pressure difference Api between pi-TARGET and pi-ACTUAL, where i is the number of the chamber whose ACTUAL pressure is controlled, and check whether Api is in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Api in dem Bereich x<0<y liegt, das erste Druckluftschaltventil der wenigstens einen Kammer i und das zweite Druckluftschaltventil der wenigstens einen Kammer i so angesteuert werden, dass sie geschlossen sind, wobei, wenn Api > y, the first compressed air switching valve of the at least one chamber i is controlled so that it is opened, wherein the second compressed air switching valve of the at least one chamber i is controlled so that it is closed, and wherein, if Api < x, the second compressed air switching valve of the at least one chamber i is controlled so that it is opened, wherein the first compressed air switching valve of the at least one chamber i is controlled so that it is closed.Furthermore, the main drive sealing systems known to date require improvement in that the sealing effect of the lips should be improved if only atmospheric pressure would have to be applied in the chambers P2 to P4, since then the lip seals L1 to L4 only press against the shaft with a differential pressure of approximately 0.2 bar.

[0086] For the purpose of improvement, a main drive sealing system is therefore provided for a drive shaft of a cutting wheel of a tunnel boring machine, comprising at least one chamber (PO) with a first pressure (pO) behind the cutting wheel, comprising at least one first chamber (P1) with a first pressure (p1), wherein the first chamber (P1) is preferably a labyrinth chamber filled with a barrier grease (HBW), at least one second chamber (P2) with a second pressure (p2), wherein the at least one second chamber (P2) is an oil and compressed air sealing chamber (P2), at least one seal (L1) between the at least one first chamber (P1) and the at least one second chamber (P2), which can withstand a differential pressure ApL1 between the at least one first chamber (P1) and the at least one second chamber (P2),preferably at least one further second chamber (P2') with a further second pressure (p2') following the at least one second chamber (P2), wherein the at least one further second chamber (P2') is an oil and compressed air sealing chamber (P2'), at least one seal (L2) between the at least one second chamber (P2) and the at least one further second chamber (P2') that can withstand a differential pressure ApL2 between the at least one second chamber (P2) and the at least one further second chamber (P2'), at least one third chamber (P3) with a third pressure (p3) following the at least one second chamber (P2) or the at least one further second chamber (P2'), wherein the at least one third chamber (P3) is a leakage detection chamber (P3), at least one seal (L2) between the at least one further second chamber (P2') and the at least one third chamber (P3),which can withstand a differential pressure ApL2 between the at least one further second chamber (P2') and that of the at least one third chamber (P3), at least one fourth chamber (P4) with a fourth pressure (p4) following the at least one third chamber (P3), wherein the at least one fourth chamber (P4) is a gear chamber (P4), at least one seal (L3) between the at least one third chamber (P3) and the at least one fourth chamber (P4) which can withstand a differential pressure ApL3 between the at least one third chamber (P3) and that of the at least one fourth chamber (P4), characterized in that at least one second chamber (P2), at least one further second chamber (P2'), at least one third chamber (P3) and / or at least one fourth chamber (P4) is pneumatically connected to an air extraction line which is pneumatically connected to a vacuum pump,do that a pressure in at least one of the chambers can be set via the vacuum pump which is lower than atmospheric pressure.,

[0087] Surprisingly, it has been shown that it is possible to easily create a pressure in one or more chambers that is less than atmospheric pressure. It has also been surprisingly shown that this can increase the sealing effect in the chambers by sucking the seal onto the shaft to be sealed.

[0088] A further solution of the invention provides that at least one air switching valve and / or at least one throttle is provided in the air extraction line (93) between one of the chambers and the vacuum pump, and that preferably the at least one air switching valve and / or the at least one throttle are electrically switchable. Furthermore, it is advantageous that at least one of the chambers is connected to at least one pressure detection device for detecting an actual pressure of the chamber. A further solution of the invention provides that a controller (80) is provided which is electrically connected to the vacuum pump (95), the at least one air switching valve (23, 23', 33, 43) and / or the at least one throttle (233, 233', 333, 433) and / or the at least one pressure detection device (24, 24', 34, 44).

[0089] It has been shown that these are simple solutions that make it easy to reduce and maintain the pressure below atmospheric pressure in a controlled manner.

[0090] A further solution of the invention provides that a controller (80) is provided which has at least one data storage unit, at least one data processing unit and at least one control command output unit, and that at least one control circuit based on the at least one electronic controller (80) is provided for controlling an actual pressure in one of the chambers (P2, P2', P3, P4), which has a program step:

[0091] Setting a target pressure for one of the chambers (P2, P2', P3, P4), receiving an actual pressure for one of the chambers (P2, P2', P3, P4), calculating a pressure difference Api between pi-target and pi-actual, controlling the vacuum pump (95), the at least one air switching valve (23, 23', 33, 43) and / or the at least one throttle (233, 233', 333, 433) to change pi-actual to pi-target.

[0092] A further solution of the invention provides that a series of the target pressures of the chambers (P1, P2, P2', P3, P4) is stored in the control (80): pO < p1-TARGET > p2-TARGET > p2'-TARGET > p3-TARGET < p4-TARGET, wherein the further second chamber (P2') and its pressure p2'-TARGET can be omitted.

[0093] Furthermore, existing main drive sealing systems may have difficulty providing sufficient lubrication throughout the entire operating life of the tunnel boring machine. Sump lubrication is often used, in which the oil collects at the lowest point of the seal and is then carried upwards by the rotation of the shaft. However, it cannot always be guaranteed that sufficient lubricant is provided at the highest point of the seal.

[0094] For the purpose of improvement, a main drive sealing system is therefore provided for a drive shaft of a cutting wheel of a tunnel boring machine, comprising at least one first chamber P1, wherein the first chamber P1 is preferably a labyrinth chamber filled with a barrier grease (HBW), at least one second chamber P2, wherein the at least one second chamber P2 is an oil and compressed air sealing chamber P2, at least one seal L1 is provided between the at least one first chamber P1 and the at least one second chamber P2, preferably at least one further second chamber P2' is provided following the at least one second chamber P2, wherein the at least one further second chamber P2' is an oil and compressed air sealing chamber P2', at least one third chamber P3 is provided following the at least one second chamber P2 or the at least one further second chamber P2',wherein the at least one third chamber P3 is a leakage detection chamber P3, at least one seal L2 is provided between the at least one second chamber P2 or the at least one further second chamber P2 and the at least one third chamber P3, at least one fourth chamber P4 is provided following the at least one third chamber P3, wherein the at least one fourth chamber (P4) is a gear chamber P4, at least one seal L3 is provided between the at least one third chamber P3 and the at least one fourth chamber P4, characterized in that for at least one of the second, further second, third and / or fourth chambers P2, P2', P4 is connected to a circulation pump for the oil located in the chamber, and that the connection is fluidically connected via at least one line to at least one suction point of the chamber P2, P2', P4 for sucking the oil out of the chamber P2, P2',P4 and is fluidically connected via at least one further line to at least one introduction point of the chamber P2, P2', P4 for introducing the oil into the chamber P2, P2', P4.

[0095] It is advantageous if the oil is filtered before or after the circulation pump, or if foreign matter is separated from the oil and / or the oil quality is tested. Circulating the oil in the respective chamber allows for a better supply of lubricant to the chamber. Furthermore, it has been shown that this method can easily achieve better lubrication of the chamber seal(s), particularly in the upper area of ​​the seal.

[0096] A further solution of the invention provides that a filter for filtering the oil is provided in front of or behind the circulation pump.

[0097] A further solution of the invention provides that a separator for separating solids or liquids in the oil is provided before or after the circulation pump.

[0098] A further solution of the invention provides that a quality control of the oil is carried out during circulation of the oil.

[0099] Furthermore, if the leakage detection chamber P3 is also filled with oil, it can also be equipped with a circulation pump.

[0100] BRIEF DESCRIPTION OF THE DRAWINGS

[0101] To better illustrate the technical solutions of embodiments of the present application or conventional technology, the drawings referred to in describing the embodiments or conventional technology are briefly described below. Obviously, the drawings in the following description are only some examples of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative effort. Herein:

[0102] Fig. 1 is a schematic diagram of the main drive seal for a shield machine according to an embodiment of the present application, Fig. 2 is a schematic representation of an inventive

[0103] Pressurization and pressure control system of the

[0104] Main drive seal structure, and

[0105] Fig. 3 - 6 schematic representations of pressure curves in the main drive seal as a function of an output pressure pO.

[0106] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0107] Fig. 1 shows the basic structure of a main drive sealing system according to the invention. A space PO is provided in front of the main drive sealing system. This space is the space behind the cutter wheel (not shown) of the tunnel boring machine and contains a slurry of loosened soil / rock, water / bentonite suspension, and possibly foam. Fluidically connected to this is the main drive sealing system, which seals the gap between the shaft of the main drive system and the tunnel boring machine. The seal functions both statically and dynamically when the cutter wheel, and thus the shaft, rotates.

[0108] The main drive sealing system is constructed from left to right as follows. First, there is a chamber P1, which is fluidly connected to the chamber PO. Chamber P1 is preferably a so-called labyrinth seal, into which a barrier grease (preferably HBW) is introduced under pressure. This is followed by a second chamber P2. Chamber P1 is separated from chamber P2 by a seal L1.

[0109] Preferably, the seal L1 is an oriented lip seal. The lip seal has an upper body on which a lip is movably arranged via a hinge-like region. The orientation is such that pressure applied in the chamber P1 presses on the lip portion of the seal L1, forcing it against the shaft.

[0110] In the prior art, a lubricating grease, for example, EP2, is usually introduced into chamber two. According to the invention, chamber P2 is an oil and compressed air sealing chamber that can be pressurized with compressed air and is hereinafter referred to synonymously as the first chamber P2, chamber P2, or oil chamber P2.

[0111] An oil and compressed air seal chamber P2' is located on top of chamber P2, which can be pressurized with compressed air and is subsequently referred to synonymously as chamber P2', second chamber P2', or oil chamber P2'. The further chamber P2 is separated from chamber P2 by a seal L2. Preferably, the seal L2 is again a lip seal oriented toward chamber P2. Chamber P2' is also a pressurized oil chamber. If necessary, additional chambers P2' can be provided as oil chambers.

[0112] Shown here, chamber P2' is followed by chamber P3, which is also referred to synonymously as leakage chamber P3 or leakage detection chamber P3 and is separated from chamber P2' by a seal L3. Chamber P3 is a leakage detection chamber. It is usually designed without a lubricant fill. It can be pressurized using compressed air. The orientation of the lip seal L2' between chamber P2' and chamber P3 is aligned with chamber P2'. Chamber P3 is used to detect whether one of the seals has failed by allowing soil slurry / liquid from space PO, lubricating oil from chamber P2 / P2' and / or gear oil from chamber P4 to enter chamber P3.

[0113] Following chamber P3 is chamber P4, which is the transmission chamber. A seal L3 is provided between chamber P3 and chamber P4. Seal L3 is preferably designed as a lip seal and is oriented toward chamber P4, thus opposing seals L1, L2, and L2'. Chamber P4 is also filled with oil—here, transmission oil—and can be pressurized with compressed air.

[0114] A pressure p1 prevails in chamber P1. The pressure p1 is set so that it is greater than the pressure pO, since the chamber P1 is designed as a barrier grease chamber with grease loss. This means that the barrier grease (HBW) is pressed into the chamber P1 under pressure and, since the barrier grease is not a so-called lifetime grease, is pressed forward into the chamber PO through the labyrinth gap. This occurs by pressing in the barrier grease with the pressure p1, which is calculated as pressure pO + a pressure increase Ap1. The pressure increase Ap1 is usually 0.5 bar.

[0115] The seals L1, L2, L2' and L3 are designed to be able to withstand a certain applied pressure until the seal is damaged and thus becomes permeable. In the case of a lip seal, the damage occurs when the lip pressed onto the shaft breaks through. With seals, a distinction is made between the permissible static differential pressure of the seal and the permissible dynamic differential pressure of the seal. The static differential pressure is significantly higher than the dynamic differential pressure. Depending on the type of seal, for example, the static differential pressure can be 12 bar and the dynamic differential pressure 5 bar. For safety reasons, the permissible dynamic differential pressure is not fully used in the design of the sealing system, but a lower differential pressure is used so that a safety buffer is provided.For a dynamic seal with a permissible dynamic differential pressure of, for example, 5 bar, this is preferably 3 bar. This pressure difference is referred to below as ApLi, where "Li" stands for the respective chamber number. To protect the seal, the ApLi can preferably be considered smaller than the previously assumed ApLi. This is referred to below as ApLi CONTROL (ApLi-ST).

[0116] In order for the sealing system to be sealed against the prevailing pressure pO in the space PO, the sealing system must provide a counterpressure to the prevailing pressure pO that is at least as large as the prevailing pressure pO. This is achieved by taking into account the differential pressures of the seals L1 to L3 and the pressurized chambers P1 to P4.

[0117] Surprisingly, it has been found that the lips of the seals L1 to L4 can be pulled closer to the shaft by providing a pressure in a chamber on the back of the seal that is less than atmospheric pressure, and thus the sealing effect of the seal can be improved in the event that atmospheric pressure or a pressure that is only slightly greater than atmospheric pressure prevails on the front of the seal.

[0118] To prevent gear oil from leaking from chamber P4 into leakage detection chamber P3, P4 is still set to a pressure p4 that is greater than the pressure p3 in chamber P3. For this purpose, an Ap4 additional pressure is provided in chamber P to increase the pressure compared to the pressure in chamber P3. This improves the sealing effect of seal L3 and prevents seal L3 from opening if pressure p3 in chamber P3 is greater than pressure p4 without Ap4 additional pressure in chamber P4, which would cause the lip section to lift off the shaft and at the same time allow gear oil to escape from chamber P4 through the opening into chamber P3.

[0119] Fig. 2 shows the schematic structure of the pressurization and pressure control system 10, with which the chambers P2 to P4 can be pressurized. At the same time, the means by which the pressures in the chambers can be adjusted depending on a changing reference pressure are shown. For this purpose, at least one control circuit based on an electronic controller 80 is provided for regulating the pressures p1 to p4 in the respective chambers. Fig. 2 shows a pressurization and pressure control system 10 according to the invention for pressurizing the chambers P2 to P4 of the sealing system and regulating the pressures depending on a possibly changing reference pressure.

[0120] For this purpose, chamber P2 is fluidically connected to a level compensation tank 20. Both chamber P2 and level compensation tank 20 contain lubricating oil. Chamber P2 and level compensation tank 20 are fluidically connected to one another via a line 60 so that the oil levels in level compensation tank 20 and chamber P2 can equalize. At the same time, level compensation tank 20 and chamber P2 are fluidically connected to one another via a compressed air line 61. The pressure originating from level compensation tank 20 in chamber P2 can be equalized via this compressed air line 61. The aforementioned structure also applies to chamber P2', which is fluidly connected to a level compensation tank 20' via an oil line 60 and a compressed air line 61. Furthermore, chamber P4 is also connected to level compensation tank 40 in the same way via an oil line 60 and a compressed air line 61.Gear oil is present in the level compensation tank 40 and the chamber P4.

[0121] Chamber P3 is also connected to the level compensation tank 30 via an oil line 60 and a compressed air line 61. However, the level compensation tank 30 primarily serves as a compressed air tank. The level compensation tank 30 can also be used to determine whether oil or liquid / foreign matter is entering chamber P3, which is normally operated oil-free, either from chamber P2 / P2' or P4 due to a malfunction. To drain this accumulated oil, chamber P3 is connected to a discharge vessel 35 via a line 36, which leads to a drain 37, preferably located in the sump of P3.

[0122] Furthermore, at least one of the chambers P2, P2', and P4 is preferably provided with a circulation pump 25, 25', 45, which is connected via a line 26, 26', 46 to a suction point 27, 27', 47 of the chamber P2, P2', P4 for sucking the oil out of the chamber P2, P2', P4. Furthermore, the circulation pump 25, 25', 45 is fluidly connected via a line 28, 28', 48 to an introduction point 29, 29', 49 of the chamber P2, P2', P4 for introducing the oil into the chamber P2, P2', P4. The circulation of the oil in the respective chamber P2, P2', P4 enables a better supply of lubricant in the chamber P2, P2' and P4 or a better lubrication of their seal L2, L2', L4, especially in the upper area of ​​the seal.

[0123] If, for example, oil lubrication is also to be provided in chamber P3, it would be advantageous to provide a corresponding circulation pump (not shown) in the same way. Additionally, a filter or separator (not shown) for separating foreign matter from the oil can be provided upstream or downstream of the circulation pump 25, 25', 45. Furthermore, a quality control of the oil can preferably be provided to determine any need for oil replacement or the need for oil cleaning.

[0124] Symbolically represented is the space PO behind the excavation chamber, which is connected to a pressure sensing device 4 for measuring the pressure pO. The measurement result is digitally converted and transmitted to the controller 80 connected to the pressure sensing device 4. These measurement data are stored accordingly in the controller 80 and used for further calculation.

[0125] The chambers P1, P2, P2', P3, and P4 are also each connected to a pressure sensing device 14, 24, 24', 34, 44 to measure the respective actual pressure in the chambers P1, P2, P2', P3, P4. These measured actual pressures p1-ACTUAL, p2-ACTUAL, p2'-ACTUAL, p3-ACTUAL, p4-ACTUAL are digitally converted and transmitted to the controller 80 connected to the pressure sensing devices 14, 24, 24', 34, 44. These measurement data are stored accordingly in the controller 80 and used for further calculations.

[0126] The pressure application system 10 further includes a compressed air source 100 connected to an inlet 71 of a compressed air input port 70. The compressed air input port 70 has an outlet 72 connected to a compressed air line 91.

[0127] The compressed air switching valves 21, 2T, 31, 41 are fluidically connected to the compressed air line 91 via their compressed air inlets 211, 2T, 311, 411. On the output side, the compressed air switching valve 21, 2T, 31, 41 has a compressed air outlet 212, 212', 312, 412, which is fluidically connected to the level compensation tank 20, 20', 30, 40. The compressed air switching valves 21, 2T, 31, 41 are connected to the controller 80 in order to receive switching commands from the controller for switching between an open and a closed position and to transmit the switching status to the controller.

[0128] Furthermore, a throttle 213, 213', 313, 413 can be provided upstream of the compressed air inlet 211, 21T, 311, 411 or downstream of the compressed air outlet 212, 212', 312, 412. The throttle can preferably be controllably connected to the controller and be adjustable. With the throttle 213, 213', 313, 413, it is possible to adjust the flow rate of the compressed air upstream or downstream of the compressed air switching valve 21, 2T, 31, 41. This is preferably done via control commands from the controller 80. Furthermore, a pressure relief line 92 is provided, which is open at one end to the environment and thus to atmospheric pressure. A silencer 96 is preferably provided between the environment and the line.

[0129] Furthermore, the pressure relief line 92 is connected to a second compressed air switching valve 22, 22', 32, 42 of the respective chamber P2, P2', P3, P4 via its compressed air outlet 222, 222', 322, 422. The compressed air inlet 221, 221, 321, 421 is fluidly connected to the level compensation tank 20, 20', 30, 40 either directly or to the line between the level compensation tank 20, 20', 30, 40 and the compressed air outlet 212, 212', 312, 412. The compressed air switching valves 22, 22', 32, 42 are connected to the controller 80 in order to receive switching commands from the controller for switching between an open and a closed position and to transmit the switching status to the controller.

[0130] Furthermore, an air extraction line 93 is provided, which is connected to the outlet side of a vacuum pump 95. The vacuum pump 95 has a discharge line to the atmosphere. The air extraction line 93 is connected to a third compressed air switching valve 23, 23', 33, 43 of the respective chamber P2, P2', P3, P4 via its compressed air outlet 232, 232', 332, 432. The compressed air inlet 231, 231', 331, 431 of the third compressed air switching valve 23, 23', 33, 43 is fluidly connected to the level compensation tank 20, 20', 30, 40. The compressed air switching valves 23, 23', 33, 43 are connected to the controller 80 to receive switching commands for switching between an open and a closed position and to transmit the switching status to the controller. The vacuum pump 95 is also connected to the controller 80.

[0131] The first compressed air switching valve 21, 22, 31, 41, the second compressed air switching valve 22, 22', 32, 42, and / or the third compressed air switching valve 23, 23', 33, 43 are each connected to the controller 80. The controller can open and close the compressed air switching valves using appropriate control commands.

[0132] The (pressure) suction line 93 is further preferably connected to a vacuum reservoir 97, which has a pressure sensing device 94. The pressure sensing device 94 is connected to the controller 80 for transmitting the measured values. With the vacuum reservoir 97, it is possible to dampen the potentially pulsating effect of the vacuum pump 95 and, at the same time, to temporarily extract air for pressure equalization without activating the vacuum pump 95. A throttle 223, 223', 323, 423 or 233, 233', 333, 433 can also be provided upstream of the compressed air inlet or compressed air outlet of the second compressed air switching valve 22, 22', 32, 42 and / or third compressed air switching valve 23, 23', 33, 43. This throttle is preferably connected to the controller 80. Furthermore, the throttle 223, 223', 323, 423 or 233, 233', 333, 433 is preferably adjustable so that the flow rate of the compressed air through the compressed air switching valves 22, 22', 32, 42 or 23, 23', 33, 43 is adjustable.

[0133] The electronic controller 80 includes at least one data storage unit, at least one data processing unit, and at least one control command output unit. The units themselves are not shown in Figure 2.

[0134] The pressure application system receives a control loop from the controller 80 for regulating the pressures p2, p2', p3, p4 in the chambers P2, P2', P3, P4. For this purpose, a control program is provided in the controller 80 with the following steps:

[0135] Receiving and storing the pressure pO from the pressure sensing device 4 and / or the pressure p1-IST from the pressure sensing device 14.

[0136] Setting and saving a pressure surcharge Ap1 and calculating the pressure p1-TARGET according to the formula p1-TARGET = pO plus Ap1. The setting is made either directly using a value provided in the program or by an operator entering a value via an input device of the control unit 80. Preferably, a test step is provided in which it is checked that p1-TARGET > pO. Only in this case is it guaranteed that chamber P1 is operated in the buffer grease loss mode. If the pressure p1-TARGET were lower than the pressure pO, there would be an additional risk that soil slurry or liquid contained in the chamber PO could penetrate into the chamber P1.

[0137] A further step in the program is to define and save the differential pressure ApL1-CONTROL (ApL1-ST), ApL2-CONTROL (ApL2-ST), ApL2'-CONTROL (ApL2'- ST), ApL3-CONTROL (ApL3-ST). If seals are not provided in the sealing system, there is no need to define and save the respective differential pressure for this seal. The same applies if additional seals are provided. A corresponding ApL would then also be defined and saved for these. Preferably, a check step is provided during the definition process to ensure that ApLi -CONTROL is less than or equal to the pressure difference ApLi for seal Li. "Li" is the seal number. The definition itself is carried out either by a value specified in the program or by an operator entering it via a control unit.If the ApLi CONTROL is selected to be smaller than the ApLi value specified by the manufacturer, this can be used to reduce the wear of the seal or to increase the safety with regard to the respective seal.

[0138] Another preferred program step is setting a reference pressure pREF, where pREF = pO + Ap1 and / or pREF = p1-ACTUAL. Setting the actual pressure in chamber P1 would be advantageous here, but has the disadvantage that pressures in the barrier grease are difficult to measure accurately due to the friction of the barrier grease and the temperature dependence of the viscosity of the barrier grease. Therefore, pREF PO + Ap1 is preferred as the reference pressure.

[0139] A further program step involves receiving and storing the actual pressure pi of the respective chamber Pi via the respective pressure sensing device 24, 24', 34, 44 of the respective chamber P2, P2', P3, P4. If a pressure pi of a chamber Pi is not to be regulated, the receiving and storing of this actual pressure can be omitted.

[0140] A further planned program step is calculating a pressure p2-TARGET according to the formula p2-TARGET = pREF- ApL1-CONTROL, or calculating a pressure p2'-TARGET according to the formula p2'-TARGET = pREF- ApL1-CONTROL - ApL2-CONTROL or according to the formula p2'-TARGET = p2-ACTUAL - ApL2-CONTROL, calculating a pressure p3-TARGET according to the formula p3-TARGET = pREF- ApL1-CONTROL - ApL2-CONTROL - ApL2'-CONTROL or according to the formula p3-TARGET = p2'-ACTUAL - ApL2'-CONTROL.

[0141] Preferably, a test step is provided for p2-TARGET to ensure that p2-TARGET lies within a range between pREF and pREF-Apl1. If p2-TARGET is greater than pREF, there is a risk that seal L1 will open and allow lubricating oil to enter chamber P1, thereby impairing the sealing effect of the barrier grease. If p2-TARGET is less than pREF-Apl1, the risk of seal L1 failing and, in the worst case, being pushed inward increases.

[0142] Preferably, a test step is provided for p2'-TARGET to ensure that p2'-TARGET lies within a range between p2-ACTUAL and p2-ACTUAL - ApL2. If p2'-TARGET is greater than p2-ACTUAL, there is a risk that seal L2 will open and lubricating oil will enter chamber P2. If p2'-TARGET is less than p2-ACTUAL - ApL2, the risk of seal L2 failing and, in the worst case, being pushed inward increases.

[0143] Preferably, a test step is provided for p3-TARGET, ensuring that p3-TARGET lies within a range between p2'-ACTUAL and p2'-ACTUAL-ApL2', as well as within a range between p4-ACTUAL and p4-ACTUAL-ApL3. If p3-TARGET is greater than p2'-ACTUAL or p4-ACTUAL, there is a risk that seal L2' or seal L3 will open and oil will enter chamber P3. If p3-TARGET is less than p2'-ACTUAL-ApL2' or p4-ACTUAL-ApL3, there is an increased risk that seal L2 or seal L3 will fail and, in the worst case, be pushed inward.

[0144] To control the pressure p2-ACTUAL / p2'-ACTUAL / p3-ACTUAL, the program calculates and saves a pressure difference Ap2 / Ap2' / Ap3 = p2-SETPOINT - p2-ACTUAL / p2'-SETPOINT - p2'-ACTUAL / p3-SETPOINT - p3-ACTUAL and checks whether the pressure difference Ap2 / Ap2' / Ap3 is in a range x<0 <y liegt, wobei x eine untere Intervallgrenze und y eine obere Intervallgrenze darstellen. Das Ansteuern der Druckluftschaltventile 21 , 22, 23 / 2T, 22‘, 23‘ / 31 , 32, 33 zum Regeln des Drucks p2-IST / p2‘-IST / p3-IST in der Kammer P2 / P2‘ / P3 erfolgt dabei nach den nachfolgenden Schritten:

[0145] If Ap2 / Ap2' / Ap3 in a range x<0 <y liegt, dann sind das erste Druckluftschaltventil 21 , 21 ‘, 31 und das zweite Druckluftschaltventil 22, 22‘, 32 sowie gegebenenfalls auch das dritte Druckluftschaltventil 23, 23‘, 33 so von der Steuerung angesteuert, dass sie geschlossen sind.

[0146] If Ap2 / Ap2' / Ap3 > y, the control command output unit of the controller 80 outputs a signal to open the first compressed air switching valve 21, 21', 31 to the first compressed air switching valve 21, 21', 31, wherein the second compressed air switching valve 22, 22', 32 and / or the third compressed air switching valve 23, 23', 33 are controlled to be closed.

[0147] If Ap2 / Ap2' / Ap3 <x ist, gibt die Steuerbefehlausgabeeinheit der Steuerung 80 ein Signal zum Öffnen des zweiten Druckluftschaltventils 22, 22‘, 32 und / oder des dritten Druckluftschaltventils 23, 23‘, 33 an das zweite Druckluftschaltventil 22, 22‘, 32 und / oder das dritte Druckluftschaltventil 23, 23‘, 33, wobei das erste Druckluftschaltventil 21 , 21 ‘, 31 so angesteuert ist, dass es geschlossen ist.

[0148] By opening and closing the compressed air switching valves 21, 22, 23 / 2T, 22', 23' / 31, 32, 33, the pressure p2-IST / p2'-IST / p3-IST is adjusted to the pressure p2-S0LL / p2'-S0LL / p3-S0LL by either adding or draining or sucking off compressed air via the compressed air switching valves 21, 22, 23 / 2T, 22', 23' / 31, 32, 33.

[0149] To regulate the pressure p4 in the chamber P4 (gearbox chamber), the control program of the electronic control system provides the following steps:

[0150] Setting and saving a pressure surcharge Ap4-SUBSTITUTION (Ap4-SUBSTITUTION); Calculating and saving a pressure p4-S0LL according to the formula p4-SOLL = P3-IST + Ap4-SUBSTITUTION;

[0151] Determining and storing the differential pressure ApL3-CONTROL, wherein preferably a check step is provided that ApL3-CONTROL is less than or equal to the pressure difference ApL3 of the seal L3;

[0152] Receiving and storing the pressure p4-ACTUAL and calculating the pressure difference Ap4 between p4-TARGET and p4-ACTUAL, and checking whether the pressure difference Ap4 is in a range x<0 <y liegt, wobei x eine untere Intervallgrenze und y eine obere Intervallgrenze darstellen. Das Ansteuern der Druckluftschaltventile 41 , 42, 43 zum Regeln des Drucks p4-IST in der Kammer P4 erfolgt dabei nach den nachfolgenden Schritten:

[0153] If Ap4 in a range x<0 <y liegt, dann sind das erste Druckluftschaltventil 41 und das zweite Druckluftschaltventil 42 sowie gegebenenfalls auch das dritte Druckluftschaltventil 43 so von der Steuerung angesteuert, dass sie geschlossen sind.

[0154] When Ap4 > y, the control command output unit of the controller 80 outputs a signal for opening the first compressed air switching valve 41 to the first compressed air switching valve 41, wherein the second compressed air switching valve 42 and / or the third compressed air switching valve 43 are controlled to be closed.

[0155] If Ap4 <x ist, gibt die Steuerbefehlausgabeeinheit der Steuerung 80 ein Signal zum Öffnen des zweiten Druckluftschaltventils 42 und / oder des dritten Druckluftschaltventils 43 an das zweite Druckluftschaltventil 42 und / oder das dritte Druckluftschaltventil 43, wobei das erste Druckluftschaltventil 41 so angesteuert ist, dass es geschlossen ist.

[0156] By opening and closing the compressed air switching valves 41, 42, 43, the pressure p4-IST is adjusted to the pressure p4-S0LL by either adding or releasing or sucking off compressed air via the compressed air switching valves 41, 42, 43.

[0157] The pressure is released from a chamber P2 to P4 preferably via the second compressed air switching valve 22, 22', 32, 42 via the compressed air discharge line 92 and the silencer 96 and / or via the third compressed air switching valves 23, 23', 33, 43 and the air extraction line 93 and the vacuum pump 95. If the calculation for a target pressure shows that this is less than or equal to atmospheric pressure, then atmospheric pressure can be applied in the corresponding chamber by the controller 80 opening the second compressed air switching valve 22, 22', 32, 42 and thus, without any further control being necessary, the atmospheric pressure is established in the corresponding chamber via the compressed air discharge line 92.

[0158] The method according to the invention for pressure control is preferably carried out in accordance with the previously described steps of the control program.

[0159] Alternatively, a pressure lower than atmospheric pressure can also be set in the corresponding chamber. For this purpose, the second compressed air switching valve 22, 22', 32, 42 remains closed, and the controller 80 activates the vacuum pump 95 to set the actual pressure in the corresponding chamber P2 to P4 to a pressure lower than atmospheric pressure via the air extraction line 93 after opening the respective third compressed air switching valve 23, 23', 33, 43. The desired pressure is set or calculated accordingly to a required value lower than atmospheric pressure.

[0160] Alternatively, the pressures in the chambers P2 to P4 can also be regulated by opening the first compressed air switching valve 21, 21', 31, 41 by the controller 80 and also opening the second compressed air switching valve 22, 22', 32, 42 and / or the third compressed air switching valve 23, 23', 33, 43. The throttles 213, 223, 233, 213', 223', 233', 313, 323, 333, 413, 423, 433 of the compressed air switching valves 21, 2T, 31, 41, 22, 22', 32, 42, 23, 23', 33, 43 are then adjusted so that in order to maintain the actual pressure in the respective chamber P2-P4, just as much compressed air flows into the respective chamber P2-P4 via the first compressed air switching valve 21, 2T, 31, 41 as flows out via the second compressed air switching valve 22, 22', 32, 42 and / or the third compressed air switching valve 23, 23', 33, 43.If the reference pressure pREF then changes, either the compressed air switching valves are briefly opened or closed in order to change the actual pressure accordingly, or the setting of the throttles is changed accordingly, so that in order to increase the actual pressure in the chamber, more compressed air flows into the chamber via the first compressed air switching valve 21, 2T, 31, 41 than flows out via the second compressed air switching valve 22, 22', 32, 42 and / or the third compressed air switching valve 23, 23', 33, 43, or in order to reduce the actual pressure in the chamber, less compressed air flows into the chamber via the first compressed air switching valve 21, 2T, 31, 41 than via the second compressed air switching valve 22, 22', 32, 42 and / or the third compressed air switching valve 23, 23', 33, 43. The setting of the throttles for increasing / decreasing the pressure is maintained accordingly until the actual pressure of the respective chamber reaches the desired pressure.

[0161] It is also possible to regulate the pressures in the respective chambers of a sealing system using a combination of control valves or throttles. Figures 3-6 show different pressure curves across chambers P1 to P4 and the seals in between in the sealing system. The prevailing pressure is plotted on the y-axis, and the respective chamber and seal on the x-axis. The x-axis itself represents the atmospheric pressure, represented as P-ATMOS.

[0162] Fig. 3 shows a pressure curve in which all chambers P1-P4 are pressurized accordingly in order to provide pressure equilibrium and generate a back pressure for the pressure pO prevailing in the space PO. First, Ap1 is added to the pressure pO, so that a higher pressure value p1 is created. From this, a pressure difference ApL1-ST is removed in the seal L1, so that a pressure p2 is established in the chamber P2 by the control. In the seal L2 between the chambers P2 and P2', the pressure difference ApL2-ST is then removed, so that in order to provide equilibrium in the chamber P2', the pressure p2' must be established. Since the pressure reduction ApL2'-ST in the seal L2' is not sufficient to prevent the chamber P3 from being pressurized, the pressure p3 in the chamber P3 must be provided.In order to increase the sealing effect of the seal L3 and to reduce the risk of the seal L3 opening, the pressure p4 in the chamber P4 is preferably increased by Ap4-ZU.

[0163] The procedure is similar in Fig. 4. Here, however, PO is smaller than in Fig. 3, so that it is possible to set the chamber P2' to atmospheric pressure using Ap1-ST and Ap2-ST. In Fig. 4, the pressure in P3 is then also set to atmospheric pressure. The intrinsic sealing effect of the seal L2' of approx. 0.2 bar, with which the lip seal L2' presses onto the shaft, is sufficient here to prevent the seal L2' from opening and oil from escaping from the chamber P2' into the chamber P3. To prevent the seal L3 from opening and gear oil from escaping from the chamber P4 into the chamber P3, again preferably an Ap4-zu is added to the pressure p3 in chamber P3 in order to set the pressure p4 in chamber P4. The pressure difference Ap4-zu must be smaller than the pressure difference ApL3 that the seal L3 can absorb.

[0164] Fig. 5 shows the same pressure curve as Figure 4 up to chamber P2'. To increase the sealing effect of the seal L2' with respect to chamber P3, a pressure below atmospheric pressure is set in chamber P3 via the vacuum pump 95 and the third compressed air switching valve 33. The pressure difference between the pressure p2' and the pressure p3 must be smaller than the ApL2' of the seal L2'. The pressure p4 is in turn increased with an Ap4-CLOSED compared to the set pressure p3. An overpressure in P4 is shown here. Alternatively, atmospheric pressure can also be present in chamber P4. Fig. 6 shows a pressure curve in which the differential pressure of the lip seal ApL1 is already sufficient to provide sufficient backpressure against PO. In this case, chambers P2 to P4 could all be pressurized to atmospheric pressure.

[0165] However, as shown in Fig. 6, it has been shown that the sealing effect of the lip seals L1 - L3 is correspondingly improved if a negative pressure < atmospheric pressure is provided in the chambers P2 to P3, thus sucking the seals L1 to L3 towards the shaft to reinforce the sealing effect. A corresponding negative pressure compared to atmospheric pressure is shown in Fig. 6 in the chambers P2, P2' and P3. Preferably, fixed values ​​are stored for this purpose in the controller 80. P4 can then again be provided with an additional pressure and set either to atmospheric pressure or to an overpressure or negative pressure in relation to atmospheric pressure. From a control technology perspective, atmospheric pressure is preferable here, since for this only the compressed air switching valve 42 needs to be opened and no further control by opening and closing compressed air switching valves is necessary.

[0166] During control, certain maximum and minimum conditions must be observed for the pressures of the individual chambers P1 to P4.

[0167] The maximum pressure in P1 is established by the pressure increase Ap 1. Higher pressure by injecting the HBW barrier grease is possible, but may not be advisable. The minimum pressure in P1 should be the pressure oO of the chamber PO. If the pressure in chamber P1 is lower than pO, there is a risk that foreign matter from the chamber PO will penetrate the seal.

[0168] To prevent seal L1 from opening due to the pressure in P2, the maximum pressure p2 in chamber P2 must be equal to the actual pressure in P1. The minimum pressure in P2 must not be less than the actual pressure in P1 minus the pressure difference ΔpL1 of seal L1.

[0169] If p2-SOLL is equal to p1-IST - ApL1-ST is less than or equal to the atmospheric pressure, then either the atmospheric pressure or a negative pressure can be set in P2.

[0170] To prevent the seal L2 between P2 and chamber P2' from opening, the maximum pressure P2' must be equal to the actual pressure P2. The minimum pressure P2' in this case is P2-actual - ApPL2, to prevent the seal L2 from failing.

[0171] If the pressure in P2' = P2-ACTUAL - ApL2 is less than or equal to atmospheric pressure, the pressure P2'-SETPOINT can be set to atmospheric pressure or a negative pressure. The maximum actual pressure p3 must not exceed the pressure p2-ACTUAL or p4-ACTUAL to prevent the seals L2' or L3 from opening. To prevent seal failure, p3-ACTUAL must not be less than the difference between p2'-ACTUAL - ApL2' or p4-ACTUAL - ApL3. According to the previously mentioned conditions, the pressure p3 can also be set to atmospheric pressure or a negative pressure. The same applies analogously to p4.

[0172] Overall, pressures must be set in the chambers which, together with the differential pressures of the seals, are able to reach equilibrium with pO.

Claims

Patent claims 1. A main drive sealing system for a drive shaft of a cutting wheel of a tunnel boring machine, comprising at least one chamber (PO) with a first pressure (pO) behind the cutting wheel, comprising at least one first chamber (P1) with a first pressure (p1), wherein the first chamber (P1) is preferably a labyrinth chamber filled with a barrier grease (HBW), at least one second chamber (P2) with a second pressure (p2), wherein the at least one second chamber (P2) is an oil and compressed air sealing chamber (P2), at least one seal (L1) between the at least one first chamber (P1) and the at least one second chamber (P2), which seal can withstand a differential pressure ApL1 between the at least one first chamber (P1) and the at least one second chamber (P2), at least one compressed air inlet connection (70), at least one compressed air outlet line (92, 93),at least one first compressed air switching valve (21) of the at least one second chamber (P2) with at least one compressed air inlet (211) and at least one compressed air outlet (212), wherein the first compressed air switching valve (21) of the at least one second chamber (P2) is configured to be switchable between an open and a closed position, at least one second compressed air switching valve (22, 23) of the at least one second chamber (P2) with at least one compressed air inlet (221, 231) and at least one compressed air outlet (222, 232), wherein the second compressed air switching valve (22, 23) of the at least one second chamber (P2) is configured to be switchable between an open and a closed position, at least one inlet (71) of the compressed air inlet connection (70) which is configured to be pneumatically connected to a compressed air source (100), at least one outlet (72) of the compressed air inlet connection (70), which is pneumatically connected via a compressed air line (91) to the at least one compressed air inlet (211) of the first compressed air switching valve (21) of the at least one second chamber (P2), wherein the at least one compressed air outlet (212) of the first compressed air switching valve (21) of the at least one second chamber (P2) is pneumatically connected to the at least one compressed air inlet (221, 231) of the second compressed air switching valve (22, 23) of the at least one second chamber (P2) and the at least one second chamber (P2), and wherein a compressed air outlet (222, 232) of the second compressed air switching valve (22, 23) of the at least one second chamber (P2) is pneumatically connected to the compressed air discharge line (92, 93), characterized in that at least one electronic control (80) is provided, which has at least one data storage unit,at least one data processing unit and at least one control command output unit, that at least one control circuit based on the at least one electronic controller (80) is provided for regulating the second pressure (p2) in the at least one second chamber (P2), that at least one first pressure sensing device (4, 14) is connected to the at least one space (P0) or the at least one first chamber (P1) in order to measure the pressure (pO) in the space or the current pressure (p1-IST) in the at least one first chamber (P1), wherein the at least one first pressure sensing device (4) is electronically connected to the at least one electronic controller (80) for transmitting the pressure, that at least one second pressure sensing device (24) is connected to the at least one second chamber (P2) in order to measure the current pressure (p2-IST) in the at least one second chamber (P2),wherein the at least one second pressure sensing device (24) is electronically connected to the at least one electronic controller (80) for transmitting the pressure, that the at least one first compressed air switching valve (21) of the at least one second chamber (P2) is connected to the at least one control device (80) so that the at least one first compressed air switching valve (21) of the at least one second chamber (P2) can be electrically switched by the control device (80), that the at least one second compressed air switching valve (22, 23) of the at least one second chamber (P2) is connected to the at least one control device (80) so that the at least one second compressed air switching valve (22, 23) of the at least one second chamber (P2) can be electrically switched by the control device (80), and that the electronic controller (80) has a control program with the following steps: Receiving and storing the pressure pO and / or the pressure p1-IST; Setting and storing the differential pressure ApL1-CONTROL (ApL1-ST), wherein preferably a check step is provided that the ApL1-CONTROL (ApL1-ST) is less than or equal to the pressure difference ApL1; Setting and storing a pressure surcharge Ap1 and calculating a pressure p1-SOLL according to the formula p1-SOLL= p0+ Ap1 , wherein preferably a check step is provided that p1-SOLL is greater than p0, Setting a reference pressure pREF, where pREF is one of the following pressures: p0+ Ap1 or p1 -IST, Receiving and storing the pressure p2-IST of the second chamber (P2), Calculating and storing a pressure p2-SOLL according to the formula p2-SOLL = pREF - ApL1- CONTROL, whereby a check step is provided that p2-SOLL lies in a range between pREF and pREF- ApL1, Calculate and store a pressure difference Ap2 between p2-TARGET and p2-ACTUAL, and Check if Ap2 in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap2 in dem Bereich x<0< y liegt, das erste Druckluftschaltventil (21) der wenigstens einen zweiten Kammer (P2) und das zweite Druckluftschaltventil (22, 23) der wenigstens einen zweiten Kammer (P2) so von der Steuerung so angesteuert sind, dass das erste Druckluftschaltventil (21) und das zweite Druckluftschaltventil (22, 23) geschlossen sind, wobei, wenn Ap2 > y, the control command output unit sends a signal for opening the first compressed air switching valve (21) of the at least one second chamber (P2) to the first compressed air switching valve (21) of the at least one second chamber (P2), wherein the second compressed air switching valve (22, 23) of the at least one second chamber (P2) is controlled so that it is closed, and wherein, if Ap2 < x, the control command output unit sends a signal for opening the second compressed air switching valve (22,23) of the at least one second chamber (P2) to the second compressed air switching valve (22, 23) of the at least one second chamber (P2), wherein the first compressed air switching valve (21) of the at least one second chamber (P2) is controlled so that it is closed., 2. Main drive sealing system for a tunnel boring machine according to claim 1, characterized in that at least one further second chamber (P2') with a further second pressure (p2') is provided following the at least one second chamber (P2), wherein the at least one further second chamber (P2') is an oil and compressed air sealing chamber (P2'), that at least one seal (L2) is provided between the at least one second chamber (P2) and the at least one further second chamber (P2'), which seal is subjected to a differential pressure ApL2 between the at least one second chamber (P2) and the at least one further second chamber (P2'), that at least one first compressed air switching valve (21') of the at least one further second chamber (P2') is provided with at least one compressed air inlet (211') and at least one compressed air outlet (212'), wherein the first compressed air switching valve (21') of the at least one further second chamber (P2') is designed such that it can be switched between an open and a closed position, that at least one second compressed air switching valve (22', 23') of the at least one further second chamber (P2') is provided with at least one compressed air inlet (221', 231') and at least one compressed air outlet (222', 232'), wherein the second compressed air switching valve (22', 23') of the at least one further second chamber (P2') is designed such that it can be switched between an open and a closed position,that at least one control circuit based on the at least one electronic controller (80) is provided for regulating the further second pressure (p2') in the at least one further second chamber (P2'), that at least one further second pressure sensing device (24') is connected to the at least one further second chamber (P2') in order to measure the current pressure (p2'-IST) in the at least one second chamber (P2'), wherein the at least one further second pressure sensing device (24') is electronically connected to the at least one electronic controller (80) for transmitting the pressure, that the at least one first compressed air switching valve (2T) of the at least one further second chamber (P2') is connected to the at least one control device (80), so that the at least one first compressed air switching valve (21') of the at least one further second chamber (P2') can be electrically switched by the control device (80),that the at least one second compressed air switching valve (22', 23') of the at least one further second chamber (P2') is connected to the at least one control device (80), so that the at least one second compressed air switching valve (22', 23') of the at least one further second chamber (P2') can be electrically switched by the control device (80), that the at least one outlet (72) of the compressed air inlet connection (70), which is pneumatically connected via a compressed air line (91) to the at least one compressed air inlet (21T) of the first compressed air switching valve (21') of the at least one further second chamber (P2'), wherein the at least one compressed air outlet (212') of the first compressed air switching valve (21') of the at least one further second chamber (P2') is connected to the at least one compressed air inlet (22T, 231') of the second compressed air switching valve (22',23') of the at least one further second chamber (P2') and the at least one further second chamber (P2') is pneumatically connected, and wherein a compressed air outlet (222', 232') of the second compressed air switching valve (22', 23') of the at least, a further second chamber (P2') is pneumatically connected to the compressed air discharge line (92, 93), and that the control program of the electronic control (80) comprises the following further steps: Setting and storing the differential pressure ApL2-CONTROL, with a check step being provided that the ApL2-CONTROL is less than or equal to the pressure difference ApL2; Receiving and storing the pressure p2'-IST of the further second chamber (P2'), Calculating and storing a pressure p2'-TARGET according to the formula p2'-TARGET = p2-ACTUAL - ApL2-CONTROL or according to the formula p2'-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL, whereby a check step is provided that p2'-TARGET lies in a range between p2-ACTUAL and p2-ACTUAL - ApL2, Calculate and store a pressure difference Ap2' between p2'-TARGET and p2'-ACTUAL, and Check if Ap2'in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap2‘ in dem Bereich x<0<y liegt, das erste Druckluftschaltventil (21 ‘) der wenigstens einen weiteren zweiten Kammer (P2‘) und das zweite Druckluftschaltventil (22‘, 23‘) der wenigstens einen weiteren zweiten Kammer (P2‘) so angesteuert sind, dass sie geschlossen sind, wobei, wenn Ap2‘ > y, the control command output unit sends a signal for opening the first compressed air switching valve (21 ') of the at least one further second chamber (P2') to the first compressed air switching valve (21 ') of the at least one further second chamber (P2'), wherein the second compressed air switching valve (22', 23') of the at least one further second chamber (P2') is controlled such that it is closed, and wherein, if Ap2' < x, the control command output unit sends a signal for opening the second compressed air switching valve (22',23') of the at least one further second chamber (P2') to the second compressed air switching valve (22', 23') of the at least one further second chamber (P2'), wherein the first compressed air switching valve (2T) of the at least one further second chamber (P2') is controlled such that it is closed.

3. Main drive sealing system for a tunnel boring machine according to claim 1 or 2, characterized in that at least one third chamber (P3) with a third pressure (p3) is provided following the at least one second chamber (P2) or the at least one further second chamber (P2'), wherein the at least one third chamber (P3) is a leak detection chamber (P3), that at least one seal (L2) is provided between the at least one second chamber (P2) or that at least one seal (L2') is provided between the at least one further second chamber (P2') and the at least one third chamber (P3), which seal is subjected to a differential pressure ApL2 between the at least one second chamber (P2) or which can withstand a differential pressure ApL2' between the at least one further second chamber (P2') and the at least one third chamber (P3), that at least one first compressed air switching valve (31) of the at least one third chamber (P3) is provided with at least one compressed air inlet (311) and at least one compressed air outlet (312), wherein the first compressed air switching valve (31) of the at least one third chamber (P3) is designed such that it can be switched between an open and a closed position, that at least one second compressed air switching valve (32, 33) of the at least one third chamber (P3) is provided with at least one compressed air inlet (321, 331) and at least one compressed air outlet (322, 323), wherein the second compressed air switching valve (32, 33) of the at least one third chamber (P3) is designed such that it can be switched between an open and a closed position,that at least one control circuit based on the at least one electronic controller (80) is provided for regulating the third pressure (p3) in the at least one third chamber (P3), that at least one third pressure sensing device (34) is connected to the at least one third chamber (P3) in order to measure the current pressure (p3-IST) in the at least one third chamber (P3), wherein the at least one third pressure sensing device (34) is electronically connected to the at least one electronic controller (80) for transmitting the pressure, that the at least one first compressed air switching valve (31) of the at least one third chamber (P3) is connected to the at least one control device (80), so that the at least one first compressed air switching valve (31) can be electrically switched by the control device (80), that the at least one second compressed air switching valve (32,33) of the at least one third chamber (P3) is connected to the at least one control device (80), so that the at least one second compressed air switching valve (32, 33) of the at least one third chamber (P3) can be electrically switched by the control device (80), that the at least one outlet (72) of the compressed air inlet connection (70), which is pneumatically connected via a compressed air line (91) to the at least one compressed air inlet (311) of the first compressed air switching valve (31) of the at least one third chamber (P3), wherein the at least one compressed air outlet (312) of the first compressed air switching valve (31) of the at least one third chamber (P3) is pneumatically connected to the at least one compressed air inlet (321, 331) of the second compressed air switching valve (32, 33) of the at least one third chamber (P3) and the at least one third chamber (P3), and wherein an outlet (322, 332) of the second compressed air switching valve (32,33) of the at least one third chamber (P3) is pneumatically connected to the compressed air discharge line (92, 93), and, that the control program of the electronic control (80) has the following further steps: Setting and storing the differential pressure ApL2-CONTROL or the differential pressure ApL2'-CONTROL, wherein a check step is provided that the differential pressure ApL2-CONTROL is less than or equal to the pressure difference ApL2, or that the differential pressure ApL2'-CONTROL is less than or equal to the pressure difference ApL2'; Receiving and storing the pressure p3-IST of the third chamber (P3), Calculating and storing a pressure p3-TARGET according to the formula p3-TARGET = (p2-ACTUAL or p2'-ACTUAL) - (ApL2-CONTROL or ApL2'-CONTROL) or according to the formula p3-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL - ApL2'-CONTROL, whereby a check step is provided in each case to ensure that p3-TARGET lies in a range between p2-ACTUAL and p2-ACTUAL -ApL2 or between p2'-ACTUAL and p2'-ACTUAL - ApL2, Calculate and store a pressure difference Ap3 between p3-TARGET and p3-ACTUAL, and Check if Ap3 in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap3 in dem Bereich x<0<y liegt, das erste Druckluftschaltventil (31) der wenigstens einen dritten Kammer (P3) und das zweite Druckluftschaltventil (32, 33) der wenigstens einen dritten Kammer (P3) so angesteuert sind, dass sie geschlossen sind, wobei, wenn Ap3 > y, the control command output unit sends a signal for opening the first compressed air switching valve (31) of the at least one third chamber (P3) to the first compressed air switching valve (31) of the at least one third chamber (P3), wherein the second compressed air switching valve (32, 33) of the at least one third chamber (P3) is controlled so that it is closed, and wherein, if Ap3 < x, the control command output unit sends a signal for opening the second compressed air switching valve (32, 33) of the at least one third chamber (P3) to the second compressed air switching valve (32,33) of the at least one third chamber (P3), wherein the first compressed air switching valve (31) of the at least one third chamber (P3) is controlled so that it is closed., 4. Main drive sealing system for a tunnel boring machine according to claim 3, characterized in that at least one fourth chamber (P4) with a fourth pressure (p4) is provided following the at least one third chamber (P3), wherein the at least one fourth chamber (P4) is a gear chamber (P4), that at least one seal (L3) is provided between the at least one third chamber (P3) and the at least one fourth chamber (P4), which can withstand a differential pressure ApL3 between the at least one third chamber (P3) and that of the at least one fourth chamber (P4), that at least one first compressed air switching valve (41) of the at least one fourth chamber (P4) is provided with at least one compressed air inlet (411) and at least one compressed air outlet (412), wherein the first compressed air switching valve (41) of the at least one fourth chamber (P4) is configured such that it can be switched between an open and a closed position, that at least one second compressed air switching valve (42, 43) of the at least one fourth chamber (P4) is provided with at least one compressed air inlet (421, 431) and at least one compressed air outlet (422, 423), wherein the second compressed air switching valve (42, 43) of the at least one fourth chamber (P4) is configured such that it can be switched between an open and a closed position, that at least one control circuit based on the at least one electronic controller (80) is provided for controlling the fourth pressure (p4) in the at least one fourth chamber (P4),that at least one third pressure sensing device (44) is connected to the at least one fourth chamber (P4) in order to measure the current pressure (p4-IST) in the at least one third chamber (P4), wherein the at least one fourth pressure sensing device (44) is electronically connected to the at least one electronic control (80) for transmitting the pressure, that the at least one first compressed air switching valve (41) of the at least one fourth chamber (P4) is connected to the at least one control device (80) so that the at least one first compressed air switching valve (41) of the at least one fourth chamber (P4) can be electrically switched by the control device (80), that the at least one second compressed air switching valve (42, 43) of the at least one fourth chamber (P4) is connected to the at least one control device (80) so that the at least one second compressed air switching valve (42,43) of the at least one fourth chamber (P4) is electrically switchable by the control device (80), that the at least one outlet (72) of the compressed air inlet connection (70), which is pneumatically connected via a compressed air line (91) to the at least one compressed air inlet (411) of the first compressed air switching valve (41) of the at least one fourth chamber (P4), wherein the at least one compressed air outlet (412) of the first compressed air switching valve (41) of the at least one fourth chamber (P4) is pneumatically connected to the at least one compressed air inlet (421, 431) of the second compressed air switching valve (42, 43) of the at least one fourth chamber (P4) and the at least one fourth chamber (P4), and wherein an outlet (422, 432) of the second compressed air switching valve (42, 43) of the at least one fourth chamber (P4) is connected to the compressed air discharge line (92, 93) is pneumatically connected, and that the control program of the electronic control (80) comprises the following further steps: Setting and saving a pressure surcharge Ap4ZUSCH LAG (Ap4ZU), Calculate and save a pressure p4-S0LL according to the formula p4-SOLL = p3-IST+ Ap4ZUSCHLAG (Ap4ZU), Setting and storing the differential pressure ApL3-CONTROL, with a check step being provided that the ApL3-CONTROL is less than or equal to the pressure difference ApL3; Receiving and storing the pressure p4-IST of the fourth chamber (P4), Calculate and save a pressure difference Ap4 between p4-TARGET and p4-ACTUAL, and check whether Ap4 in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Ap4 in dem Bereich x<0<y liegt, das erste Druckluftschaltventil (41) der wenigstens einen vierten Kammer (P4) und das zweite Druckluftschaltventil (42, 43) der wenigstens einen vierten Kammer (P4) so angesteuert sind, dass sie geschlossen sind, wobei, wenn Ap4 > y, the control command output unit sends a signal for opening the first compressed air switching valve (41) of the at least one fourth chamber (P4) to the first compressed air switching valve (41) of the at least one fourth chamber (P4), wherein the second compressed air switching valve (42, 43) of the at least one fourth chamber (P4) is controlled so that it is closed, and wherein, if Ap4 < x, the control command output unit sends a signal for opening the second compressed air switching valve (42,43) of the at least one fourth chamber (P4) to the second compressed air switching valve (42, 43) of the at least one fourth chamber (P4), wherein the first compressed air switching valve (41) of the at least one fourth chamber (P4) is controlled so that it is closed., 5. Main drive sealing system for a tunnel boring machine according to one of claims 1 to 4, characterized in that the at least one compressed air outlet (222, 232, 222', 232', 322, 332, 422, 432) of the second compressed air switching valve (22, 23, 22', 23', 32, 33, 42, 43) of the at least one second chamber (P2), the at least one further second chamber (P2'), the at least one third chamber (P3) and / or the at least one fourth chamber (P4) is pneumatically connected to the compressed air discharge line (92), which is preferably connected to the environment via a silencer (96), and / or is pneumatically connected to an air suction line (93) which is connected to a vacuum pump (95), wherein the vacuum pump (95) is preferably controllable via the controller (80).

6. Main drive sealing system for a tunnel boring machine according to one of claims 1 to 5, characterized in that at least one of the chambers (P2, P2', P3, P4) is connected to at least one third compressed air switching valve (23, 23', 33, 43) which is pneumatically connected with its compressed air outlet (232, 232', 332, 432) to an air suction line (93) which is connected to a Vacuum pump (95) is connected so that a pressure less than atmospheric pressure can be set in the connected chamber, wherein the vacuum pump (95) is preferably controllable via the controller (80).

7. Main drive sealing system for a tunnel boring machine according to one of claims 1 to 6, characterized in that a series of the desired pressures of the chambers (P1, P2, P2', P3, P4) is stored in the controller (80): pO < p1-S0LL > p2-S0LL > p2'-S0LL > p3-S0LL < p4-S0LL, wherein the further second chamber (P2') and its pressure p2'-S0LL can be omitted.

8. Main drive sealing system for a tunnel boring machine according to one of claims 1 to 7, characterized in that, if the target pressure is calculated to be less than atmospheric pressure in at least one of the chambers (P2, P2', P3, P4), the target pressure is set in the control system to 1 bar or to a defined value between 0 bar and atmospheric pressure, which can then be adjusted by switching the third compressed air switching valve (23, 23', 33, 43) of the respective chamber (P2, P2', P3, P4) by the control system (80), the air suction line (93) and the vacuum pump (95), wherein the vacuum pump (95) is preferably controllable via the control system (80).

9. Main drive sealing system for a tunnel boring machine according to one of claims 1 to 8, characterized in that, if pO + Ap1 is smaller than ApL1-CONTROL, the target pressures of the chambers (P2, P2', P3, P4) in the control (80) are set to atmospheric pressure or at least one of the target pressures (p2-TARGET, p2'-TARGET, p3-TARGET, p4-TARGET) of the chambers (P2, P2', P3, P4) in the control (80) is set to a defined value between 0 bar and atmospheric pressure, which can then be adjusted by switching the third compressed air switching valve (23, 23', 33, 43) of the respective chamber (P2, P2', P3, P4) by the control (80), the air extraction line (93) and the vacuum pump (95), wherein preferably the vacuum pump (95) is controlled via the control (80) is controllable.

10. Main drive sealing system for a tunnel boring machine according to one of claims 1 to 9, characterized in that for at least one of the chambers (P2, P2', P4) a circulation pump (25, 25', 45) is provided for the oil located in the chamber, which is fluidically connected via at least one line (26, 26', 46) to at least one suction point (27, 27', 47) of the chamber (P2, P2', P4) for sucking the oil out of the chamber (P2, P2', P4) and via at least one further line (28, 28', 48) to at least one introduction point (29, 29', 49) of the chamber (P2, P2', P4) for introducing the oil into the chamber (P2, P2', P4).

11. Main drive sealing system for a tunnel boring machine according to one of claims 6 to 10, characterized in that the air extraction line (93) is provided with at least one Vacuum reservoir (97) is connected, which is preferably connected to a pressure detection device (94).

12. A method for regulating the pressure in a main drive sealing system for a drive shaft of a cutting wheel of a tunnel boring machine, comprising at least one chamber (PO) with a first pressure (pO) behind the cutting wheel of the tunnel boring machine, in particular according to one of claims 1 to 11, wherein the chamber (PO) is connected to a pressure sensing device (4), and wherein the main drive sealing system has the following features: at least one first chamber (P1) with a first pressure (p1), wherein the first chamber (P1) is preferably a labyrinth chamber filled with a barrier grease (HBW), wherein the first chamber (P1) is connected to a pressure sensing device (4), at least one second chamber (P2) with a second pressure (p2), wherein the at least one second chamber (P2) is an oil and compressed air sealing chamber (P2), wherein the second chamber (P2) is connected to a pressure sensing device (24),preferably at least one further second chamber (P2') with a further second pressure (p2'), wherein the at least one further second chamber (P2') is an oil and compressed air sealing chamber (P2'), wherein the further second chamber (P2') is connected to a pressure sensing device (24'), at least one third chamber (P3) with a third pressure (p3), wherein the at least one third chamber (P3) is a leakage detection chamber (P3), wherein the third chamber (P3) is connected to a pressure sensing device (34), at least one fourth chamber (P4) with a fourth pressure (p4), wherein the at least one fourth chamber (P4) is a transmission chamber (P4), wherein the fourth chamber (P4) is connected to a pressure sensing device (44), in each case at least one lip seal (L1, L2, L2', L3) between the chambers (P1, P2, P2', P3, P4), which each with a differential pressure (ApL1 , ApL2, ApL2',ApL3) between the adjacent chambers, and at least one electronic control (80) having at least one data storage unit, at least one data processing unit and at least one control command output unit, wherein at least one program for providing a control loop based on the at least one electronic control (80) for the pressure to be controlled (p2-IST, p2'-IST, p3-IST, p4-IST) is executed in the control, with the method steps: Measuring, receiving and storing the pressure pO and / or the pressure p1 -IST, Setting and storing a pressure surcharge Ap1 and calculating a pressure p1-S0LL according to the formula p1-S0LL= p0+ Ap1 , wherein preferably a check step is provided that p1-SOLL is greater than p0, Calculating a reference pressure (pREF), where the reference pressure is the pressure pO in the first space (PO) + pressure surcharge Ap1 or the pressure (p1-IST) in the first chamber (P1), Measuring and receiving at least one actual pressure to be controlled (p2-IST, p2'-IST, p3-IST, p4-IST); Setting a differential pressure of at least one lip seal (ApL1-CONTROL, ApL2-CONTROL, ApL2'-CONTROL, ApL3-CONTROL), Setting and saving a pressure surcharge (Ap4SUBSTITUTION) between the third and fourth chambers (P3, P4), Calculate a target pressure (p2-TARGET, p2'-TARGET, p3-TARGET, p4-TARGET) using at least one of the following formulas:

1. p2-TARGET = pREF - ApL1-CONTROL 2. p2'-TARGET = p2-ACTUAL - ApL2-CONTROL or p2'-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL, 3. p3-TARGET = (p2-ACTUAL or p2'-ACTUAL) - (ApL2-CONTROL or ApL2'-CONTROL) or p3-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL - ApL2'-CONTROL, and 4. p4-TARGET = p3-ACTUAL+ Ap4ADD or p4-TARGET = pREF - ApL1-CONTROL - ApL2-CONTROL - ApL2'-CONTROL + Ap4SURCHARGE, Calculate a pressure difference Api between pi-TARGET and pi-ACTUAL, where i is the number of the chamber whose ACTUAL pressure is controlled, and check whether Api is in a range x<0 <y liegt, wobei x, y eine untere Intervallgrenze und eine obere Intervallgrenze sind, wobei, wenn Api in dem Bereich x<0<y liegt, das erste Druckluftschaltventil (21 , 2T, 31 , 41) der wenigstens einen Kammer i (P2, P2‘, P3, P4) und das zweite Druckluftschaltventil (22, 23, 22‘, 23‘, 32, 33, 42, 43) der wenigstens einen Kammer i (P2, P2‘, P3, P4) so angesteuert werden, dass sie geschlossen sind, wobei, wenn Api > y, the first compressed air switching valve (21, 2T, 31, 41) of the at least one chamber i (P2, P2', P3, P4) is controlled so that it is opened, wherein the second compressed air switching valve (22, 23, 22', 23', 32, 33, 42, 43) of the at least one chamber i (P2, P2', P3, P4) is controlled so that it is closed, and wherein, if Api < x, the second compressed air switching valve (22, 23, 22', 23', 32, 33, 42,43) of the at least one chamber i (P2, P2', P3, P4) is controlled so that it is opened, wherein the first compressed air switching valve (21, 2T, 31, 41) of the at least one chamber i (P2, P2', P3, P4) is controlled so that it is closed., 13. Main drive sealing system for a drive shaft of a cutting wheel of a tunnel boring machine, comprising at least one first chamber (P1), wherein the first chamber (P1) is preferably a labyrinth chamber filled with a barrier grease (HBW), at least one second chamber (P2), wherein the at least one second chamber (P2) is an oil and compressed air sealing chamber (P2), at least one seal (L1) is provided between the at least one first chamber (P1) and the at least one second chamber (P2), preferably at least one further second chamber (P2') is provided following the at least one second chamber (P2), wherein the at least one further second chamber (P2') is an oil and compressed air sealing chamber (P2'), at least one third chamber (P3) is provided following the at least one second chamber (P2) or the at least one further second chamber (P2'), wherein the at least one third chamber (P3) is a leakage detection chamber (P3), at least one seal (L2) is provided between the at least one second chamber (P2) or the at least one further second chamber (P2') and the at least one third chamber (P3), at least one fourth chamber (P4) is provided following the at least one third chamber (P3),wherein the at least one fourth chamber (P4) is a gear chamber (P4), at least one seal (L3) is provided between the at least one third chamber (P3) and the at least one fourth chamber (P4), characterized in that for at least one of the second, further second, third and / or fourth chambers (P2, P2', P4) is connected to a circulation pump (25, 25', 45) for the oil located in the chamber, and in that the connection is fluidically connected via at least one line (26, 26', 46) to at least one suction point (27, 27', 47) of the chamber (P2, P2', P4) for sucking the oil out of the chamber (P2, P2', P4) and via at least one further line (28, 28', 48) to at least one introduction point (29, 29', 49) of the chamber (P2, P2', P4) for introduction of the oil into the chamber (P2, P2', P4) is provided., 14. Main drive sealing system for a tunnel boring machine according to claim 13, characterized in that a filter for filtering the oil and / or a separator for separating solids or liquids is provided upstream or downstream of the circulation pump (25, 25', 45).

15. Main drive sealing system for a drive shaft of a cutting wheel of a tunnel boring machine with at least one space (PO) with a first pressure (pO) behind the cutting wheel, comprising at least one first chamber (P1) with a first pressure (p1), wherein the first chamber (P1) is preferably a labyrinth chamber filled with a barrier grease (HBW), at least one second chamber (P2) with a second pressure (p2), wherein the at least one second chamber (P2) is an oil and compressed air sealing chamber (P2), at least one seal (L1) between the at least one first chamber (P1) and the at least one second chamber (P2), which can withstand a differential pressure ApL1 between the at least one first chamber (P1) and the at least one second chamber (P2), preferably at least one further second chamber (P2') with a further second pressure (p2') following the at least one second chamber (P2), wherein the at least one further second chamber (P2') is an oil and compressed air sealing chamber (P2'), at least one seal (L2) between the at least one second chamber (P2) and the at least one further second chamber (P2'), which can withstand a differential pressure ApL2 between the at least one second chamber (P2) and the at least one further second chamber (P2'),at least one third chamber (P3) with a third pressure (p3) following the at least one second chamber (P2) or the at least one further second chamber (P2'), wherein the at least one third chamber (P3) is a leakage detection chamber (P3), at least one seal (L2) between the at least one further second chamber (P2') and the at least one third chamber (P3) that can withstand a differential pressure ApL2 between the at least one further second chamber (P2') and that of the at least one third chamber (P3), at least one fourth chamber (P4) with a fourth pressure (p4) following the at least one third chamber (P3), wherein the at least one fourth chamber (P4) is a transmission chamber (P4), at least one seal (L3) between the at least one third chamber (P3) and the at least one fourth chamber (P4),which can withstand a differential pressure ApL3 between the at least one third chamber (P3) and that of the at least one fourth chamber (P4), characterized in that at least one second chamber (P2), at least one further second chamber (P2'), at least one third chamber (P3) and / or at least one fourth chamber (P4) is pneumatically connected to an air extraction line (93) which is pneumatically connected to a vacuum pump (95), so that a pressure in at least one of the chambers which is lower than atmospheric pressure can be set via the vacuum pump.

16. Main drive sealing system for a tunnel boring machine according to claim 15, characterized in that between one of the chambers (P2, P2', P3, P4) and the vacuum pump (95) and at least one air switching valve (23, 23', 33, 43) and / or at least one throttle (233, 233', 333, 433) is provided in the air suction line (93), and that preferably the at least one air switching valve (23, 23', 33, 43) and / or the at least one throttle (233, 233', 333, 433) are electrically switchable.

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