Sealing structure and sealing condition monitoring method

Abstract

The application discloses a sealing structure and a sealing state monitoring method. The sealing structure comprises at least one first groove arranged between a support ring and a wear-resistant band, and a sealing layer filled in the first groove; at least one second groove arranged between the support ring and the wear-resistant band, and a sealing starting layer arranged in the second groove, wherein the sealing starting layer comprises an oil-soluble outer membrane, and the oil-soluble outer membrane is filled with a preset liquid. When a gap is generated between the support ring and the wear-resistant band and grease leaks, the leaked grease can dissolve the oil-soluble outer membrane of the sealing starting layer in the second groove, and the preset liquid in the oil-soluble outer membrane can flow into the first groove, so that the sealing layer is expanded to realize sealing, thereby blocking the grease leakage channel between the support ring and the wear-resistant band, and the grease cannot leak out, thereby avoiding the problem that the sealing system of the main drive is difficult to build pressure and cannot normally operate, and the failure state of the sealing structure can be known in time, so that the sealing structure can be processed in time.

Description

Technical Field

[0001] This invention relates to the field of sealing technology, and in particular, to a sealing structure and a method for monitoring the sealing status. Background Technology

[0002] During operation, the tunnel boring machine (TBM) experiences complex working conditions, which can lead to sand, gravel, mud, and water entering the sealing cavity, causing significant wear on the runway. This results in high maintenance costs and long construction periods. To reduce runway wear, the current measure is to install wear-resistant steel strips on the support rings. However, due to insufficient roundness at the weld joints of the wear-resistant steel strips, they cannot fit tightly against the support rings, leading to poor sealing of the main drive and oil leakage. Furthermore, because the wear-resistant steel strips exhibit significant thermal expansion and contraction, friction between the sealing structure and the wear-resistant steel strips during tunneling generates heat, causing the wear-resistant steel strips to expand and creating gaps between them and the support rings. This results in grease leakage, making it difficult for the main drive's sealing system to build up pressure, preventing the grease from being properly extruded, and hindering its ability to prevent foreign matter from entering the slurry chamber.

[0003] Currently, the only way to solve the problem of grease leakage in the gap between the wear-resistant steel belt and the support ring of the tunnel boring machine is to apply sealant to fill the gap and prevent grease leakage. However, the sealing is not timely and the sealing effect is not obvious, so the oil leakage problem cannot be completely solved. Summary of the Invention

[0004] The purpose of this invention is to provide a sealing structure and a sealing status monitoring method to solve the technical problem of grease leakage caused by gaps easily generated between the wear-resistant steel belt of the main drive and the support ring of the tunnel boring machine.

[0005] The above-mentioned objectives of the present invention can be achieved by the following technical solutions:

[0006] This invention provides a sealing structure, comprising: at least one first groove disposed between a support ring and a wear-resistant strip, the first groove being filled with a sealing layer; and at least one second groove disposed between the support ring and the wear-resistant strip, the second groove being provided with a sealing activation layer, the sealing activation layer comprising an oil-soluble outer membrane, the oil-soluble outer membrane containing a preset liquid; wherein the oil-soluble outer membrane can be dissolved by leaked grease, causing the preset liquid inside it to flow into the first groove, thereby causing the sealing layer to expand and achieve a seal.

[0007] In embodiments of the present invention, the sealing structure further includes a sealing status monitoring structure, which is used to monitor the force between the support ring and the wear-resistant strip and monitor the sealing status of the sealing structure according to the change of the force.

[0008] In an embodiment of the present invention, the sealing condition monitoring structure includes a force detection module, which is disposed between the support ring and the wear-resistant belt and is located near the first groove.

[0009] In an embodiment of the present invention, the sealing condition monitoring structure further includes an early warning module, which is signal-connected to the force detection module. The early warning module is used to determine that the sealing structure is in a failure state and issue an early warning when the applied force is greater than a preset value.

[0010] In an embodiment of the present invention, the stress detection module includes a plurality of strain gauges, a sealant layer is laid between the support ring and the wear-resistant belt, and the plurality of strain gauges are bonded and fixed to both sides of the first groove by the sealant layer.

[0011] In embodiments of the present invention, there are multiple second grooves, and at least one second groove is provided on each side of the first groove.

[0012] In embodiments of the present invention, the material of the sealing layer includes a polyurethane prepolymer, the preset liquid includes water, and the polyurethane prepolymer expands upon contact with water to form polyurethane foam.

[0013] In embodiments of the present invention, there are multiple sealing structures, and the multiple sealing structures are arranged at intervals along the axial direction of the support ring.

[0014] The present invention also includes a sealing condition monitoring method for monitoring the sealing condition of the above-mentioned sealing structure, comprising the following steps: monitoring the force between the support ring and the wear-resistant strip; when the force is lower than a preset value, determining that the sealing structure is in a failure state.

[0015] In embodiments of the present invention, the method further includes: when the applied force is a first stable value, determining that the sealing structure is in an unactivated state; when the applied force decreases from the first stable value to a second stable value, and the second stable value is greater than the preset value, determining that the sealing structure is in a sealed state.

[0016] The features and advantages of this invention are:

[0017] In the sealing structure of this invention, when a gap is generated between the support ring and the wear-resistant belt and grease leaks, the leaked grease can dissolve the oil-soluble outer film of the sealing activation layer in the second groove, causing the preset liquid inside to flow into the first groove. This causes the sealing layer in the first groove to expand and achieve a seal, thereby blocking the grease leakage channel between the support ring and the wear-resistant belt. Grease cannot leak out, thus avoiding the problem of grease leakage causing the main drive sealing system to have difficulty building pressure and to malfunction.

[0018] The sealing condition monitoring method of the present invention can determine that the sealing structure is in a failure state when the force between the support ring and the wear-resistant strip changes before and after the sealing layer expands. This is because the force between the support ring and the wear-resistant strip changes before and after the expansion of the sealing layer. This allows for timely handling of the issue. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the sealing structure of the present invention.

[0021] Figure 2 This is a diagram showing the arrangement of the multiple sealing structures of the present invention.

[0022] In the picture:

[0023] 1. Support ring; 2. Wear-resistant belt; 3. Sealing structure; 31. First groove; 32. Sealing layer; 33. Second groove; 34. Sealing start layer; 35. Oil-soluble outer membrane; 36. Preset liquid; 37. Stress detection module; 38. Strain gauge; 39. Sealing adhesive layer. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Implementation Method 1

[0026] like Figure 1 As shown, the present invention provides a sealing structure, comprising: at least one first groove 31 disposed between a support ring 1 and a wear-resistant belt 2, wherein the first groove 31 is filled with a sealing layer 32; at least one second groove 33 disposed between the support ring 1 and the wear-resistant belt 2, wherein the second groove 33 is provided with a sealing activation layer 34, the sealing activation layer 34 comprising an oil-soluble outer membrane 35, wherein the oil-soluble outer membrane 35 is filled with a preset liquid 36; wherein the oil-soluble outer membrane 35 can be dissolved by leaked grease, causing the preset liquid 36 inside it to flow into the first groove 31, thereby causing the sealing layer 32 to expand and achieve a seal.

[0027] In the sealing structure of the present invention, when a gap is generated between the support ring 1 and the wear-resistant belt 2 and grease leaks, the leaked grease can dissolve the oil-soluble outer film 35 of the sealing activation layer 34 in the second groove 33, causing the preset liquid 36 inside to flow into the first groove 31, causing the sealing layer 32 in the first groove 31 to expand and achieve a seal, thereby blocking the grease leakage channel between the support ring 1 and the wear-resistant belt 2, preventing grease from leaking out, and thus avoiding the problem of grease leakage causing the main drive sealing system to have difficulty building pressure and failing to operate normally.

[0028] Specifically, such as Figure 1 As shown, the inner circumferential surface of the support ring 1 is sealed to the outer circumferential surface of the wear-resistant belt 2. The first groove 31 and the second groove 33 can be annular grooves formed on the inner circumferential surface of the support ring 1, or annular grooves formed on the outer circumferential surface of the wear-resistant belt 2, or annular grooves on the outer wall of the wear-resistant belt 2 and annular grooves on the support ring 1 can be formed by their relative fit. When a gap is formed between the support ring 1 and the wear-resistant belt 2, the gap will form a grease leakage channel, and the leaked grease will flow along the grease leakage channel to the second groove 33, causing the oil-soluble outer membrane 35 of the sealing activation layer 34 to be dissolved, and the internal preset liquid 36 to flow out, and then also flow along the grease leakage channel to the first groove 31, causing the sealing layer 32 in the first groove 31 to react with the preset liquid 36 and expand, thereby blocking the grease leakage channel. In this embodiment, the material of the sealing layer 32 is polyurethane prepolymer, and the preset liquid 36 is water. The polyurethane prepolymer expands when it comes into contact with water to form polyurethane foam. Of course, the material of the sealing layer 32 can also be other expandable sealing materials in the prior art, such as water-swellable rubber. The preset liquid 36 can also be selected from other liquids that cannot dissolve the oil-soluble outer membrane 35 but can cause the sealing layer 32 to expand. The oil-soluble outer membrane 35 can be a thin film made of resin that is soluble in grease but insoluble in water, as is currently available in the art. In addition, the preset liquid 36 can be injected into the second groove 33 and then covered with the oil-soluble outer membrane 35 for encapsulation, thereby forming the sealing activation layer 34. Alternatively, the preset liquid 36 can be coated with the oil-soluble outer membrane 35 to form beads, and then multiple beads can be filled into the second groove 33.

[0029] The sealing layer 32 expands due to the reaction with the preset liquid 36, achieving a seal. This allows for a significant change in the force between the support ring 1 and the wear-resistant belt 2. Utilizing this characteristic, such as... Figure 1As shown, in an embodiment of the present invention, the sealing structure further includes a sealing state monitoring structure. This structure monitors the force between the support ring 1 and the wear-resistant belt 2 and monitors the sealing state of the sealing structure based on changes in the force. When the force between the support ring 1 and the wear-resistant belt 2 stabilizes at a first stable value, it indicates that the sealing layer 32 has not expanded, thus indicating that no grease leakage has occurred and the sealing structure is in an inactive state. When the force between the support ring 1 and the wear-resistant belt 2 decreases from the first stable value to a second stable value, and this second stable value is greater than a preset value, it indicates that the sealing layer 32 has expanded, thus indicating that grease leakage has occurred, but the sealing structure remains sealed, and the grease leakage channel is blocked by the sealing layer 32. Furthermore, since the degree of expansion and sealing of the sealing layer 32 is limited, if the temperature of the wear-resistant belt 2 gradually increases and it further deforms, causing the gap between the support ring 1 and the wear-resistant belt 2 to further increase, the force between the support ring 1 and the wear-resistant belt 2 will decrease from the second stable value and fall below the preset value, indicating that the gap between the support ring 1 and the wear-resistant belt 2 is large, and grease has passed through the sealing layer 32, thus indicating that the sealing structure is in a failed state. In this embodiment, a sealant layer 39 is laid between the support ring 1 and the wear-resistant belt 2. The stress detection module 37 includes multiple strain gauges 38, which are bonded and fixed to both sides of the first groove 31 by the sealant layer 39. By setting the sealant layer 39, the sealing performance between the support ring 1 and the wear-resistant belt 2 can be improved, and the strain gauges 38 can be fixed.

[0030] like Figure 1 As shown, the sealing condition monitoring structure includes a force detection module 37, which is located between the support ring 1 and the wear-resistant strip 2, and close to the first groove 31. By positioning the force detection module 37 close to the first groove 31, the change in force between the support ring 1 and the wear-resistant strip 2 before and after the expansion of the sealing layer 32 can be detected more accurately and promptly. Specifically, the distance between the first groove 31 and the second groove 33 is preferably, but not limited to, 7 mm. The distance between the force detection module 37 and the first groove 31 is preferably, but not limited to, 3 mm.

[0031] like Figure 1 As shown, the sealing condition monitoring structure also includes an early warning module, which is signal-connected to the force detection module 37. The early warning module is used to determine that the sealing structure is in a failure state and issue an early warning when the applied force is less than a preset value. When the sealing structure fails, the early warning module can issue an early warning in a timely manner, thus enabling timely handling.

[0032] like Figure 1In the embodiments of the present invention, there are multiple second grooves 33, and at least one second groove 33 is provided on both sides of the first groove 31. Regardless of which side of the first groove 31 experiences grease leakage, the pre-set liquid 36 inside the sealing activation layer 34 can first leak out by flowing into the second groove 33, and then flow into the second groove 33 to activate the sealing layer 32 to expand and seal.

[0033] Furthermore, in order to form multiple seals and further improve the reliability of the seal, such as... Figure 2 As shown, in the embodiment of the present invention, there are multiple sealing structures 3, which are arranged at intervals along the axial direction of the support ring 1. Specifically, each sealing structure 3 includes a first groove 31, a second groove 33 located on both sides of the first groove 31, and a strain gauge 38 located between the first groove 31 and the second groove 33 and close to the first groove 31. Based on the change in the force between the support ring 1 and the wear-resistant band 2 detected by the strain gauge 38 in each sealing structure 3, the state of each sealing structure 3 can be detected, and the location of grease leakage and the location of seal failure can be analyzed. When the warning modules of all sealing structures 3 issue warnings, it indicates that all sealing structures 3 are in a failed state.

[0034] Implementation Method 2

[0035] like Figure 1 As shown, the present invention also provides a sealing state monitoring method for monitoring the sealing state of the sealing structure 3, comprising the following steps: monitoring the force between the support ring 1 and the wear-resistant belt 2; when the force is lower than a preset value, determining that the sealing structure 3 is in a failure state. The sealing structure 3 in this embodiment is the same as the sealing structure 3 in embodiment one in terms of specific structure, working principle and beneficial effects, and will not be described again here.

[0036] In embodiments of the present invention, the method further includes: determining that the sealing structure 3 is in an unactivated state when the applied force is at a first stable value; and determining that the sealing structure 3 is in a sealed state when the applied force decreases from the first stable value to a second stable value, and the second stable value is greater than a preset value. The first and second stable values ​​are not limited to any specific value but are values ​​that fluctuate less and tend to be stable.

[0037] The sealing condition monitoring method of the present invention can determine that the sealing structure 3 is in a failure state when the force between the support ring 1 and the wear-resistant belt 2 changes before and after the expansion of the sealing layer 32. By monitoring the force between the support ring 1 and the wear-resistant belt 2, the sealing structure 3 can be judged to be in a failure state when the force between the support ring 1 and the wear-resistant belt 2 is lower than a preset value, so that timely processing can be carried out.

[0038] The above descriptions are merely a few embodiments of the present invention. Those skilled in the art can make various modifications or variations to the embodiments of the present invention based on the content disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A sealing structure, characterized in that, include: At least one first groove is provided between the support ring and the wear-resistant belt, and the first groove is filled with a sealing layer; A second groove is provided between the support ring and the wear-resistant belt. A sealing start-up layer is provided in the second groove. The sealing start-up layer includes an oil-soluble outer membrane, and the oil-soluble outer membrane is filled with a preset liquid. The oil-soluble outer membrane can be dissolved by leaked grease, causing the preset liquid inside to flow along the grease leakage channel into the first groove, thereby causing the sealing layer to expand and achieve a seal. The number of second grooves is multiple, and at least one second groove is provided on each side of the first groove; The sealing layer is made of polyurethane prepolymer, and the preset liquid is water. The polyurethane prepolymer expands upon contact with water to form polyurethane foam.

2. The sealing structure according to claim 1, characterized in that, The sealing structure also includes a sealing status monitoring structure, which is used to monitor the force between the support ring and the wear-resistant strip and monitor the sealing status of the sealing structure according to the change of the force.

3. The sealing structure according to claim 2, characterized in that, The sealing condition monitoring structure includes a stress detection module, which is located between the support ring and the wear-resistant belt, and close to the first groove.

4. The sealing structure according to claim 3, characterized in that, The sealing condition monitoring structure also includes an early warning module, which is signal-connected to the force detection module. The early warning module is used to determine that the sealing structure is in a failure state and issue an early warning when the applied force is lower than a preset value.

5. The sealing structure according to claim 3, characterized in that, The stress detection module includes multiple strain gauges. A sealant layer is laid between the support ring and the wear-resistant belt. The multiple strain gauges are bonded and fixed to both sides of the first groove through the sealant layer.

6. The sealing structure according to claim 1, characterized in that, The number of sealing structures is multiple, and the multiple sealing structures are arranged at intervals along the axial direction of the support ring.

7. A method for monitoring the sealing status, characterized in that, The method for monitoring the sealing status of the sealing structure according to any one of claims 1-6 includes the following steps: Monitor the force between the support ring and the wear-resistant belt; When the applied force is lower than a preset value, the sealing structure is determined to be in a failed state.

8. The sealing condition monitoring method according to claim 7, characterized in that, Also includes: When the applied force is at the first stable value, the sealing structure is determined to be in an inactive state. When the applied force decreases from the first stable value to the second stable value, and the second stable value is greater than the preset value, the sealing structure is determined to be in a sealed state.

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