Active compensation type sealing mechanism, heading machine main drive sealing system and sealing adjusting method

Abstract

The invention discloses an active compensation type sealing mechanism, a heading machine main drive sealing system and a sealing adjustment method. The problems that in the prior art, a sealing device cannot actively adjust the sealing compensation amount and control the temperature, and an abrasion monitoring device is difficult to track the abrasion condition in real time are solved. The active compensation type sealing mechanism comprises an elastic sealing body, a cavity used for containing media is formed in the elastic sealing body, a valve piece is arranged on the elastic sealing body, the elastic sealing body is connected with a medium filling system through the valve piece, and the medium filling system adds or subtracts the media into the cavity through the valve piece. And the elastic sealing body deforms to perform active compensation type sealing. According to the active compensation type sealing mechanism, the sealing compensation amount is actively adjusted through medium charging and discharging, and long-term effective work of the sealing mechanism is achieved. A non-contact type online detection device is adopted, the sealing system is matched with an online monitoring device, and the problems that in the prior art, the machining or mounting coaxiality error is large, the construction distance of complex geology is long, the sealing elasticity is insufficient due to vibration and the like, and the compensation amount is insufficient and compensation cannot be achieved due to sealing elasticity qualification are solved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical seals, and in particular to a seal and a seal adjustment method that can be used for a main drive of a tunneling machine. Background Art

[0002] The tunnel boring machine is a tunnel boring machine, in which the main drive system is called the "heart" of the tunnel boring machine, providing power for the rotation of the cutterhead and is the core component that provides power output for the tunnel boring machine. The main drive seal is used to prevent external impurities such as slag and dust from contacting the main drive, so the main drive seal plays a vital role in the main drive life and tunneling efficiency.

[0003] However, in long-distance construction, complex geological conditions, and vibrations during excavation, the wear of seals and sealing runways will be aggravated, leading to seal failure. At the same time, for large-diameter tunnel boring machines, the coaxiality errors in the processing and installation of their rings can only be passively compensated by existing seals or even cannot be compensated due to their own insufficient elasticity, resulting in poor sealing effect or even seal failure, as well as seal failure caused by abnormal temperature. In addition, existing seal wear monitoring devices or methods are difficult to achieve online wear monitoring of the entire excavation cycle.

[0004] In the prior art, for example, the Chinese patent with publication number CN215410181U designs a high-pressure reinforced main drive seal structure, which adds four single-lip finger seals on the basis of the original conventional single-lip finger VD rubber seal. However, its seal compensation method is passive compensation, which is compensated by the elasticity of the seal itself. However, for large-diameter tunneling machines with large eccentricity, the seal itself is insufficient in elasticity, resulting in failure of the seal when compensation is impossible, and it is impossible to actively intervene to adjust the seal compensation amount.

[0005] The Chinese patent with publication number CN114412994A designs a large main drive sealing structure, which injects grease into the cavity through a grease pressure channel, and at the same time, the second sealing surface is fitted to the surface of the rotating shaft to make it fit. However, its sealing compensation method is still passive sealing. In response to geological changes, large instantaneous impacts, etc., it is easy to cause uneven sealing stress and impurities to enter, causing seal wear. The sealing compensation amount cannot be adjusted according to actual working conditions. In addition, in response to high cold and high heat environments, the temperature control effect cannot be achieved, and abnormal temperature can easily lead to seal failure.

[0006] The Chinese patent with publication number CN115682893 designs a sealing ring wear monitoring device, which wraps and packages the resistance grid component and fixes it on the wear surface of the sealing ring. The seal wear condition is judged by detecting the resistance value constructed by the resistance grid. However, it can only detect when the seal is damaged, and the resistance of the monitoring device will increase instantaneously, which cannot accurately monitor the seal wear during the process.

[0007] Therefore, in the above-mentioned related technologies, the main drive sealing system of the tunnel boring machine has the problem that it is unable to actively adjust the sealing compensation amount, control the temperature, and the wear monitoring device is difficult to track the wear condition in real time. There is currently no effective solution. Therefore, it is necessary to design a main drive sealing system and an online wear monitoring device that can actively adjust the sealing compensation amount and control the sealing temperature. Summary of the invention

[0008] In view of the deficiencies in the above-mentioned background technology, the present invention proposes an active compensating sealing mechanism, a main drive sealing system of a tunnel boring machine and a sealing adjustment method, which solve the problems in the prior art that the sealing device cannot actively adjust the sealing compensation amount, control the temperature, and the wear monitoring device is difficult to track the wear condition in real time.

[0009] The technical solution of the present invention is implemented as follows: an active compensating sealing mechanism includes an elastic sealing body, a cavity for containing a medium is provided in the elastic sealing body, a valve is provided on the elastic sealing body, the elastic sealing body is connected to a medium filling system through the valve, the medium filling system adds or subtracts medium into or out of the cavity through the valve, and the elastic sealing body is deformed to perform active compensating sealing.

[0010] Preferably, a temperature sensor for detecting the medium temperature is provided on the medium filling system and / or the elastic sealing body; the medium filling system, valve components and temperature sensor are all connected to the background controller; a control closed loop can be formed; that is, the medium filling system and valve components can be switched on and off and adjusted according to the temperature sensor to improve the control accuracy.

[0011] Further preferably, the medium filling system includes a pump body, which is connected to the valve member through a pipeline. The background controller controls the opening of the valve member and the flow rate of the medium pumped by the pump body according to the medium temperature detected by the temperature sensor, thereby achieving the purpose of controlling the temperature of the sealing member.

[0012] Further preferably, a mounting groove is provided at the bottom of the cavity, a magnetic metal measured part is fixed in the mounting groove, the magnetic metal measured part corresponds to the eddy current ranging sensor arranged outside the elastic sealing body, and the eddy current ranging sensor is connected to the background controller.

[0013] A main drive sealing system for a tunnel boring machine comprises a grease ring, a sealing runway and the active compensating sealing mechanism, wherein the active compensating sealing mechanism is arranged between the grease ring and the sealing runway.

[0014] Further preferably, the grease ring and the sealing track are divided into several sealing cavities by a sealing spacer ring, and the elastic sealing body is arranged in the corresponding sealing cavity; the elastic sealing body located in the outermost sealing cavity is limited and fixed by a sealing pressure ring; the elastic sealing body is provided with at least one pressure sensor for detecting the pressure in the cavity; according to the pressure value in the elastic sealing body detected by the pressure sensor, the sealing compensation amount can be actively adjusted.

[0015] Further preferably, the pipeline is an oil channel opened in the grease ring or a pipeline arranged in the oil channel, and the oil channel is connected to the sealing cavity; the valve member is a one-way valve, and at least two one-way valves are provided on the elastic sealing body; one can be used as a medium inlet and the other can be used as a medium outlet.

[0016] Further preferably, the eddy current ranging sensor is embedded in a sealed runway, and a non-magnetic cover is provided on the eddy current ranging sensor, and the eddy current ranging sensor is arranged corresponding to the magnetic metal measured part in the elastic sealing body cavity; ensuring that the eddy current ranging sensor can accurately detect the magnetic metal measured part.

[0017] Further preferably, the magnetic metal test piece is an annular piece composed of N segment rings, N≥2, and a gap with different seam widths is left between two adjacent segment rings to form N breakpoints with different break distances; the eddy current ranging sensor outputs a regular periodic signal, and then the sealing detection position can be quickly determined based on the periodic signal.

[0018] A sealing adjustment method for a main drive sealing system of a tunnel boring machine is characterized in that: lubricating oil enters the sealing cavity through an oil passage provided in a grease ring to perform a first-layer sealing; on the premise of ensuring that the first-layer sealing meets the standard, an active compensation sealing method is selected to actively adjust the sealing compensation amount according to the working conditions; an active temperature control method is used to adjust the temperature of the sealing system according to the medium temperature; and a non-contact wear detection method is used to detect the wear of the elastic sealing body online;

[0019] The active compensation sealing method is as follows: assuming that the pressure in the cavity of the elastic sealing body is P0 under the ideal working state, when the pressure sensor on the elastic sealing body used to detect the pressure in the cavity detects that the pressure in the cavity is less than P0, the background controller controls the medium filling system to fill the cavity with medium through pipelines and valves, and the elastic sealing body expands until the pressure in the cavity reaches P0. At this time, the working surfaces of the elastic sealing body abut against the grease ring and the sealing runway respectively; when the pressure sensor on the elastic sealing body used to detect the pressure in the cavity detects that the pressure in the cavity is greater than P0, the background controller controls the medium filling system to extract the medium from the cavity through pipelines and valves, and the elastic sealing body shrinks until the pressure in the cavity reaches P0; the function of actively adjusting the sealing compensation amount is realized;

[0020] The active temperature control method is as follows: assuming that the temperature range of the medium in the cavity of the elastic sealing body under the ideal working state is [t1, t2], and the real-time temperature detected by the temperature sensor for detecting the temperature of the medium is t; if t<t1, the background controller reduces the medium flow rate and increases the medium temperature through the pump body of the medium filling system, so that the temperature of the medium in the cavity is quickly increased to the ideal state; similarly, if t>t2, the background controller increases the medium flow rate and reduces the medium temperature through the pump body of the medium filling system, so that the temperature of the medium in the cavity is quickly reduced to the ideal state.

[0021] The process of online detection of the wear of the elastic seal by the non-contact wear detection method is as follows:

[0022] The magnetic metal test piece is divided into N segment rings along the annular direction, N ≥ 2, and gaps with different seam widths are left between two adjacent segment rings to form N breakpoints with different break distances; the eddy current distance measuring sensor rotates with the sealing runway, and the target sealing point for real-time monitoring can be obtained from the periodic signal output by the eddy current distance measuring sensor;

[0023] Assuming the speed of the sealing runway is ω, the phase of the target sealing point at time t can be calculated by the speed:

[0024]

[0025] Then the detection distance corresponding to the target sealing point is D[φ(t)];

[0026] Assume that under ideal conditions, the distance between the eddy current ranging sensor and the magnetic metal test piece is D0. At this time, D0 is equal to the wall thickness of the working area of ​​the elastic sealing body when the lower boundary of the elastic sealing body is close to the sealing runway; after a period of time, the elastic sealing body is worn to a certain extent, and the change △D[φ(t)]=D[φ(t)]-D0; if △D[φ(t)]<0, it means that the seal is worn, and the seal compensation amount can be actively adjusted or replaced according to the change; if △D[φ(t)]>0, it means that the lower boundary of the elastic sealing body is not close to the sealing runway, and the active compensation sealing method is selected to actively adjust the seal compensation amount according to the change.

[0027] The beneficial effects of the present invention are as follows: compared with the prior art, the active compensation sealing mechanism of the present invention actively adjusts the sealing compensation amount by charging and discharging the medium, thereby realizing the long-term effective operation of the sealing mechanism and further improving the sealing effect. In addition, the present invention adopts a non-contact online detection device, that is, an eddy current ranging sensor is used in conjunction with a built-in magnetic metal test piece. The use of this sealing system in conjunction with the online monitoring device solves the problems in the prior art of large coaxiality errors in processing or installation, long distances in complex geological construction, vibrations, etc., which lead to insufficient sealing elasticity and insufficient compensation and inability to compensate due to the qualitative nature of sealing elasticity.

[0028] The main drive sealing system of the tunnel boring machine of the present invention adopts an active compensation sealing mechanism, which actively adjusts the sealing compensation amount by adjusting the inner cavity pressure of the seal to prevent seal failure. The temperature and flow rate of the medium are adjusted according to the real-time sealing temperature measured by the temperature sensor to achieve the effect of controlling the sealing temperature, and can avoid seal failure caused by abnormal sealing temperature under high temperature and high altitude cold working conditions. Online monitoring is achieved for the seal wear condition, and the pressure in the seal cavity can be adjusted according to the seal wear condition, and active intervention can be made to prevent economic losses caused by seal wear failure, thereby further improving the construction efficiency of the tunnel boring machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0030] Figure 1 It is a schematic diagram of the application state of the active compensating sealing mechanism of the present invention on the main drive of the tunnel boring machine.

[0031] Figure 2 It is a schematic diagram of the structure of the elastic sealing body of the present invention.

[0032] Figure 3 It is a schematic diagram of the structure of the magnetic metal test piece of the present invention.

[0033] Figure 4 It is a schematic cross-sectional view of the elastic sealing body of the present invention.

[0034] Figure 5 It is a schematic diagram of the active temperature control process of the present invention.

[0035] Figure 6 Schematic diagram of the magnetic metal test piece in Example 4 of the present invention.

[0036] Figure 7 This is a schematic diagram of the periodic signal output by the eddy current ranging sensor in Example 4 of the present invention after collecting data from a magnetic metal test piece. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] like Figure 1As shown in Example 1, the technical solution of the present invention is implemented as follows: an active compensating sealing mechanism includes an elastic sealing body 2, wherein a cavity 2-1 for holding a medium is provided in the elastic sealing body 2, and by filling and discharging the medium in the cavity, the elastic sealing body can undergo corresponding deformation to ensure its durable sealing. It should be pointed out that the medium injected into the sealed inner cavity can be a liquid or a gas. Among them, the liquid can be but not limited to hydraulic oil, gear oil, and the gas can be but not limited to high-pressure air. When high-pressure air is used as the medium, the sealing requirements are higher, but compared with hydraulic oil, the acquisition of high-pressure air is simpler and the cost is lower, and once a leak occurs, the high-pressure air will not cause pollution to the environment, which is more environmentally friendly. Of course, whether to use liquid or gas as the medium can be selected according to the actual working conditions. A valve member 4 is provided on the elastic sealing body 2, and the elastic sealing body 2 is connected to the medium filling system through the valve member 4, and the valve member 4 is used to realize the on and off of the flow of the medium. The medium filling system adds and subtracts the medium into the cavity 2-1 through the valve member 4, and the elastic sealing body 2 undergoes deformation to perform active compensating sealing. That is, when medium is added into the cavity 2-1, the elastic sealing body 2 expands and the sealing area is increased; when medium is discharged, the elastic sealing body 2 shrinks and the sealing area is reduced, thereby realizing the function of actively adjusting the sealing compensation amount.

[0039] In this embodiment, the medium filling system and / or the elastic sealing body 2 are provided with a temperature sensor 14 for detecting the medium temperature; the medium filling system, the valve member 4 and the temperature sensor 14 are all connected to the background controller. The medium is injected into the sealing member through the medium filling system, and the upper computer judges and processes the temperature measured by the temperature sensor during the medium circulation process, and adjusts the temperature and flow rate of the medium in real time according to the measured temperature, so as to achieve the effect of controlling the sealing temperature through the heat conduction effect during the medium flow process.

[0040] Embodiment 2, an active compensating sealing mechanism, this embodiment is further improved on the basis of embodiment 1. The medium filling system described in this embodiment includes a pump body 15, and the pump body 15 is connected to the valve member 4 through a pipe 5; in this embodiment, a temperature sensor 14 is arranged on the pipe 5, and the background controller controls the opening of the valve member 4 and the flow rate of the medium pumped by the pump body 15 according to the medium temperature detected by the temperature sensor 14. It should be pointed out that a temperature regulator for physically adjusting the temperature of the medium can be connected to the pipeline; the temperature and flow rate of the medium are adjusted in real time by the temperature measured by the temperature sensor, so that the sealing temperature control can be achieved for high temperature environment and high altitude cold working conditions, and the sealing failure caused by abnormal temperature can be avoided.

[0041] In this embodiment, as a preferred solution, Figure 4As shown, the bottom of the cavity 2-1 is provided with a mounting groove 16, and a magnetic metal test piece 3 is fixedly provided in the mounting groove 16. The setting of the mounting groove can ensure the stability of the magnetic metal test piece 3, and can also enable the eddy current distance sensor 10 to always detect the magnetic metal test piece 3 after the elastic sealing body 2 is deformed. The magnetic metal test piece 3 corresponds to the eddy current distance sensor 10 arranged on the outside of the elastic sealing body 2; the eddy current distance sensor 10 can always detect the distance of the magnetic metal test piece 3, and the eddy current distance sensor 10 is connected to the background controller. The distance of the magnetic metal test piece 3 is detected by the eddy current distance sensor 10 to judge the wear amount of the elastic sealing body 2. If wear occurs, that is, the corresponding wall thickness on the elastic sealing body 2 becomes thinner, then the distance of the magnetic metal test piece 3 relative to the sensor becomes smaller.

[0042] Embodiment 3, as Figure 1 The main drive sealing system of a tunnel boring machine comprises a grease ring 6, a sealing runway 13 and the active compensating sealing mechanism described in Example 1 or 2; the active compensating sealing mechanism is arranged between the grease ring 6 and the sealing runway 13. The grease ring 6 is a main drive fixed ring, and the sealing runway 13 is a main drive moving part; the elastic sealing body 2 serves as the sealing body, and its main body is a cavity structure, and the working surfaces abut the main drive fixed ring and the moving ring respectively; the monitored object, i.e., the magnetic metal measured object 3, is arranged inside, and the detection device, i.e., the eddy current ranging sensor 10, is arranged on the main drive moving ring to monitor the wear of the main drive seal. The medium filling system is placed in the external space of the main drive, and is connected to the grease hole through a pipeline for transmitting the medium.

[0043] There is a gap between the grease ring (outer fixed ring) and the sealing runway (inner moving ring) of the main drive of the tunnel boring machine. In order to prevent the front impurities from entering the gap during the tunneling process, it is necessary to set multiple seals in the gap to ensure the stable operation of the main drive. The upper part of the seal abuts against the outer fixed ring, and the lower part abuts against the inner moving ring. When the seal compensation amount is insufficient, the medium can be injected into the cavity of the seal body through the grease hole to adjust the pressure of the inner cavity of the seal to expand the seal; similarly, when the seal compensation amount is large, the medium in the inner cavity of the seal can be discharged, so that a better sealing effect can be achieved for different working conditions, and external impurities can be blocked from entering. The temperature can be measured by the temperature sensor, and the medium temperature and flow rate can be adjusted by medium heat conduction to achieve a temperature control effect. The online wear monitoring device is arranged on the inner rotating ring. By following the rotation of the inner ring, the online monitoring of the wear of each seal is realized. The online wear monitoring device is used to monitor the wear of the seal located between the structural parts so that the seal maintains the sealing state of the structural parts.

[0044] In this embodiment, as a preference, the grease ring 6 and the sealing runway 13 are divided into several sealing cavities by a sealing spacer ring 1; in this embodiment, three sealing spacers 1 are taken as an example to form four sealing cavities, and four elastic sealing bodies 2 are arranged in the corresponding four sealing cavities. The elastic sealing body 2 in the outermost sealing cavity is fixed by a sealing pressure ring 7; the sealing pressure ring 7 is fixed to the end of the grease ring 6 by a bolt 8. In this embodiment, at least one pressure sensor for detecting the pressure in the cavity 2-1 is provided on the elastic sealing body 2. During operation, the sealing compensation amount is actively adjusted according to the pressure in the cavity 2-1 monitored by the pressure sensor, so as to further improve the adjustment accuracy.

[0045] As an implementation mode, the pipeline 5 in this embodiment is an oil passage 5-1 opened in the grease ring 6 or a pipeline arranged in the oil passage, and the oil passage is connected to the sealing cavity; the valve member 4 is a one-way valve, and at least two one-way valves are arranged on the elastic sealing body 2; the one-way valve on each sealing member ensures that there are one-way valves in both directions of inflow and outflow, such as Figure 2 As shown, the arrangement position and quantity of the one-way valves are not limited to Figure 2 The situation shown. By pumping the medium into the seal cavity through a pump, the function of actively adjusting the seal cavity pressure and the seal compensation amount can be realized. The seal is located between the main drive moving ring and the fixed ring. The seal cavity and the grease hole are connected through a one-way valve. The medium can flow into the seal cavity or the grease hole through the one-way valve. By adjusting the seal cavity pressure, the seal working surface is respectively against the main drive fixed ring and the moving ring, and the function of actively adjusting the seal compensation amount is realized.

[0046] As an implementation method, the eddy current ranging sensor 10 described in this embodiment is embedded in the sealing runway 13 through the mounting base 11, and a non-magnetic cover plate 9 is provided on the eddy current ranging sensor 10, and the eddy current ranging sensor 10 is arranged corresponding to the magnetic metal measured object 3 in the cavity of the elastic sealing body 2. A non-magnetic pressure cover is arranged at the opening of the sensor, and its working principle is to monitor the change of the object, and measure the distance from the sensor monitoring end to the monitored object by converting the change, and then obtain the seal wear condition. At the same time, because the sensor is arranged on the sealing runway, only one sensor needs to be arranged for each seal, and the overall wear condition of the seal can be obtained through the rotation movement of the sealing runway.

[0047] By adjusting the structure of the monitored object, a periodic signal can be obtained from the output. Specifically, Figure 3 As shown, the magnetic metal test piece 3 is a ring-shaped piece composed of N segment rings, N ≥ 2, and gaps with different seam widths are left between two adjacent segment rings; forming N breakpoints with different break distances; Figure 6As shown, there are two separated fault distances in the ab interval and a continuous section in the fault distances at both ends, and the fan angle corresponding to each section is small. Taking the monitored object rotating clockwise as an example and taking any point as the starting point for monitoring, the output result is as follows Figure 7 As shown, the coordinate positions corresponding to point a and point b can be analyzed from the figure, so the seal wear monitoring device rotates with the ring and the output result can be a periodic signal.

[0048] The eddy current ranging sensor 10 transmits the monitored distance signal through the signal acquisition and output module 12. It should be pointed out that the signal acquisition and output module 12 can be embedded in the sealed runway or not; its installation position can be selected at will based on the ability to realize information transmission and processing. In this embodiment, the acquisition and output module 12 is embedded in the sealed runway as an example. Among them, the signal acquisition and output module 12 includes a sensor signal conditioning module, an MCU data processing module, and a ZigBee signal wireless transmission module. The wear monitoring sensor monitors the distance from the monitored object, and the sensor signal is subjected to signal conditioning, A / D conversion, and MCU internal program flow calculation processing. The Zig Bee wireless data module transmits the signal to the host computer, monitors the seal wear in real time, and actively intervenes according to the wear condition to prevent losses caused by seal damage or failure. In the present invention, the wear monitoring sensor converts data into wireless signals for transmission through the wireless communication module, transmits the collected signals to the host computer and processes them, and monitors the seal wear through the host computer. And because the sensor is arranged on the sealing runway, only one sensor is required for each seal to meet the requirement of monitoring the wear of the entire ring seal in actual work. In this solution, different breakpoints are set for the monitored object, i.e., the magnetic metal test piece 3, every 90°, so that a periodic signal output by the sensor can be obtained and the real-time monitoring seal position can be obtained from it. Figure 3 shown.

[0049] Embodiment 4, a sealing adjustment method for the main drive sealing system of a tunnel boring machine as described in Embodiment 3, wherein the lubricating oil enters the sealing cavity through the oil passage 5-1 opened in the grease ring 6 to perform the first layer of sealing; that is, the sealing body is connected to the oil passage of the grease hole through a one-way valve, and a sealing spacer ring is provided between each seal, and the sealing spacer ring is also connected to the grease hole, and grease is injected into each sealing cavity through the grease hole to form a seal; on the premise of ensuring that the first layer of sealing meets the standard, an active compensation sealing method is selected according to the working conditions to actively adjust the sealing compensation amount; an active temperature control method is adopted according to the medium temperature to adjust the temperature of the sealing system; and a non-contact wear detection method is adopted to detect the wear condition of the elastic sealing body 2 online; the three modes of active adjustment of the sealing compensation amount, temperature adjustment and wear condition monitoring can be performed simultaneously or independently in steps.

[0050] The active compensation sealing method is as follows: assuming that the pressure in the cavity of the elastic sealing body 2 is P0 under the ideal working state, when the pressure sensor on the elastic sealing body 2 for detecting the pressure in the cavity 2-1 detects that the pressure in the cavity 2-1 is less than P0, the background controller controls the medium filling system to fill the cavity 2-1 with medium through the pipeline 5 and the valve 4, and the elastic sealing body 2 deforms and expands until the pressure in the cavity 2-1 reaches P0. At this time, the working surfaces of the elastic sealing body 2 are respectively in contact with the grease ring 6 and the sealing runway 13; when the pressure sensor on the elastic sealing body 2 for detecting the pressure in the cavity 2-1 detects that the pressure in the cavity 2-1 is greater than P0, the background controller controls the medium filling system to extract the medium from the cavity 2-1 through the pipeline 5 and the valve 4, and the elastic sealing body 2 deforms and shrinks until the pressure in the cavity 2-1 reaches P0; the function of actively adjusting the sealing compensation amount is realized.

[0051] The above-mentioned active compensation sealing method can actively and efficiently adjust the pressure in the seal inner cavity. As a result, by controlling the pressure in the seal inner cavity, the seal compensation amount is actively adjusted. Therefore, active compensation can be performed for coaxiality errors in long-distance excavation, strong vibration environment, and large-diameter tunnel boring machine ring processing and installation, thereby preventing abnormal wear and failure of the seal in the above-mentioned situations.

[0052] Active temperature control methods are: Figure 5 As shown, the temperature sensor transmits the temperature data to the controller through the A / D converter, and processes it according to the real-time temperature. Specifically, suppose that the temperature range of the medium in the cavity of the elastic sealing body 2 under the ideal working state is [t1, t2], and the real-time temperature detected by the temperature sensor 14 for detecting the temperature of the medium is t; if t<t1, the background controller reduces the medium flow rate and increases the medium temperature through the pump body of the medium filling system, so that the temperature of the medium in the cavity is quickly increased to the ideal state; similarly, if t>t2, the background controller increases the medium flow rate and reduces the medium temperature through the pump body of the medium filling system, so that the temperature of the medium in the cavity is quickly reduced to the ideal state.

[0053] The above active temperature control method can efficiently control the sealing temperature. As a result, the temperature and flow rate of the medium are adjusted in real time by the temperature measured by the temperature sensor. Therefore, the sealing temperature can be controlled in high temperature environments and high altitude cold working conditions to avoid sealing failure caused by abnormal temperature.

[0054] The process of online detection of the wear condition of the elastic sealing body 2 by the non-contact wear detection method is as follows:

[0055] The magnetic metal test piece 3 is divided into N segmented rings along the annular direction, N ≥ 2, and gaps with different seam widths are left between two adjacent segmented rings to form N breakpoints with different break distances; in this embodiment, N = 4 is taken as an example; the eddy current ranging sensor 10 rotates with the sealing runway 13, and the target sealing point for real-time monitoring can be obtained from the periodic signal output by the eddy current ranging sensor 10; Figure 6 As shown, there are two separated fault distances in the ab interval and a continuous section in the fault distances at both ends, and the fan angle corresponding to each section is small. Taking the monitored object rotating clockwise as an example and taking any point as the starting point for monitoring, the output result is as follows Figure 7 As shown, the coordinate positions corresponding to point a and point b can be analyzed from the figure, so the seal wear monitoring device can obtain an output result as a periodic signal as the ring rotates, so as to quickly obtain the wear site information.

[0056] Assuming the speed of the sealing runway is ω, the phase of the target sealing point at time t can be calculated by the speed:

[0057]

[0058] Then the detection distance corresponding to the target sealing point is D[φ(t)];

[0059] Assume that under ideal conditions, the distance between the eddy current ranging sensor 10 and the magnetic metal test piece 3 is D0. At this time, D0 is equal to the wall thickness of the working area of ​​the elastic sealing body 2 when the lower boundary of the elastic sealing body 2 is close to the sealing runway; after a period of time, the elastic sealing body 2 is worn to a certain extent, and the change △D[φ(t)]=D[φ(t)]-D0; if △D[φ(t)]<0, it means that the seal is worn, and the seal compensation amount can be actively adjusted or replaced according to the change; if △D[φ(t)]>0, it means that the lower boundary of the elastic sealing body 2 is not close to the sealing runway, and the active compensation sealing method is selected to actively adjust the seal compensation amount according to the change.

[0060] The present invention adopts the main drive sealing system of the tunnel boring machine, which can realize the functions of actively adjusting the sealing compensation amount and controlling the temperature. The online wear monitoring device can realize online monitoring of the sealing wear condition, effectively avoiding the sealing failure caused by insufficient sealing compensation amount and abnormal temperature, and solving the problem of difficulty in online monitoring of sealing wear.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An active compensating sealing mechanism, characterized in that: The invention comprises an elastic sealing body (2), wherein a cavity (2-1) for containing a medium is provided in the elastic sealing body (2), a valve component (4) is provided on the elastic sealing body (2), the elastic sealing body (2) is connected to a medium filling system via the valve component (4), the medium filling system adds or subtracts medium into or out of the cavity (2-1) via the valve component (4), and the elastic sealing body (2) is deformed to perform active compensatory sealing.

2. The active compensating sealing mechanism according to claim 1, characterized in that: The medium filling system and / or the elastic sealing body (2) are provided with a temperature sensor (14) for detecting the temperature of the medium; the medium filling system, the valve element (4) and the temperature sensor (14) are all connected to a background controller.

3. The active compensating sealing mechanism according to claim 2, characterized in that: The medium filling system comprises a pump body (15), the pump body (15) being connected to a valve member (4) via a pipeline (5), and a background controller controlling the opening of the valve member (4) and the flow rate of the medium pumped by the pump body (15) according to the medium temperature detected by a temperature sensor (14).

4. The active compensating sealing mechanism according to any one of claims 1 to 3, characterized in that: The bottom of the cavity (2-1) is provided with a mounting groove (16), a magnetic metal measured object (3) is fixedly arranged in the mounting groove (16), the magnetic metal measured object (3) corresponds to an eddy current distance measuring sensor (10) arranged outside the elastic sealing body (2), and the eddy current distance measuring sensor (10) is connected to a background controller.

5. A main drive sealing system for a tunnel boring machine, characterized in that: It comprises a grease ring (6), a sealing track (13) and the active compensating sealing mechanism as claimed in claim 4, wherein the active compensating sealing mechanism is arranged between the grease ring (6) and the sealing track (13).

6. The main drive sealing system of the tunnel boring machine according to claim 5, characterized in that: The grease ring (6) and the sealing track (13) are divided into a plurality of sealing cavities by a sealing spacer ring (1), and the elastic sealing body (2) is arranged in the corresponding sealing cavity; the elastic sealing body (2) in the outermost sealing cavity is fixed by a sealing pressure ring (7); and the elastic sealing body (2) is provided with at least one pressure sensor for detecting the pressure in the cavity (2-1).

7. The main drive sealing system of a tunnel boring machine according to claim 6, characterized in that: The pipeline (5) is an oil passage (5-1) opened in the grease ring (6) or a pipeline arranged in the oil passage, and the oil passage is connected with the sealing cavity; the valve element (4) is a one-way valve, and at least two one-way valves are arranged on the elastic sealing body (2).

8. The main drive sealing system of a roadheader according to claim 6 or 7, characterized in that: The eddy current distance measuring sensor (10) is embedded in the sealed runway (13), and a non-magnetic cover plate (9) is provided on the eddy current distance measuring sensor (10). The eddy current distance measuring sensor (10) is arranged corresponding to the magnetic metal measured part (3) in the cavity of the elastic sealing body (2).

9. The main drive sealing system of a roadheader according to claim 8, characterized in that: The magnetic metal test piece (3) is an annular piece composed of N segmented rings, N≥2, and gaps with different seam widths are left between two adjacent segmented rings.

10. A sealing adjustment method for a main drive sealing system of a tunnel boring machine as claimed in claim 9, characterized in that: The lubricating oil enters the sealing cavity through the oil passage (5-1) provided in the grease ring (6) to perform the first layer of sealing; on the premise of ensuring that the first layer of sealing meets the standard, an active compensation sealing method is selected to actively adjust the sealing compensation amount according to the working conditions; an active temperature control method is used to adjust the temperature of the sealing system according to the medium temperature; and a non-contact wear detection method is used to detect the wear condition of the elastic sealing body (2) online; The active compensation sealing method is as follows: assuming that the pressure in the cavity of the elastic sealing body (2) is P0 in an ideal working state, when the pressure sensor on the elastic sealing body (2) for detecting the pressure in the cavity (2-1) detects that the pressure in the cavity (2-1) is less than P0, the background controller controls the medium filling system to fill the cavity (2-1) with medium through the pipeline (5) and the valve component (4), and the elastic sealing body (2) deforms and expands until the pressure in the cavity (2-1) reaches P0. At this time, the working surface of the elastic sealing body (2) abuts against the grease ring (6) and the sealing runway (13) respectively; when the pressure sensor on the elastic sealing body (2) for detecting the pressure in the cavity (2-1) detects that the pressure in the cavity (2-1) is greater than P0, the background controller controls the medium filling system to extract the medium from the cavity (2-1) through the pipeline (5) and the valve component (4), and the elastic sealing body (2) deforms and shrinks until the pressure in the cavity (2-1) reaches P0. Realize the function of actively adjusting the sealing compensation amount; The active temperature control method is as follows: assuming that the temperature range of the medium in the cavity of the elastic sealing body (2) under an ideal working state is [t1, t2], and the real-time temperature detected by the temperature sensor (14) for detecting the temperature of the medium is t; If t<t1, the background controller reduces the medium flow rate and increases the medium temperature through the pump body of the medium filling system, so that the temperature of the medium in the cavity is quickly increased to the ideal state; similarly, if t>t2, the background controller increases the medium flow rate and reduces the medium temperature through the pump body of the medium filling system, so that the temperature of the medium in the cavity is quickly reduced to the ideal state.

11. The sealing adjustment method of the main drive sealing system of a tunnel boring machine according to claim 10, characterized in that: The process of the non-contact wear detection method for online detection of the wear condition of an elastic sealing body (2) is as follows: a magnetic metal test piece (3) is divided into N segmented rings along the circumferential direction, N≥2, and gaps with different seam widths are left between two adjacent segmented rings to form N breakpoints with different break distances; an eddy current distance sensor (10) rotates along a sealing runway (13), and a target sealing point for real-time monitoring can be obtained from a periodic signal output by the eddy current distance sensor (10); Assuming the speed of the sealing runway is ω, the phase of the target sealing point at time t can be calculated by the speed: Then the detection distance corresponding to the target sealing point is D[φ(t)]; Assume that the distance between the eddy current distance measuring sensor (10) and the magnetic metal test piece (3) under an ideal state is D0. At this time, D0 is equal to the wall thickness of the working area of ​​the elastic sealing body (2) when the lower boundary of the elastic sealing body (2) is in close contact with the sealing track. After a period of time, the elastic sealing body (2) is worn to a certain extent, and the change amount △D[φ(t)]=D[φ(t)]-D0. If △D[φ(t)]<0, it means that the seal is worn, and the seal compensation amount can be actively adjusted or replaced according to the change amount. If △D[φ(t)]>0, it means that the lower boundary of the elastic sealing body (2) is not in close contact with the sealing track, and the active compensation sealing method is selected to actively adjust the seal compensation amount according to the change amount.

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