Screw shaft sealing device

Abstract

The invention discloses a screw shaft sealing device, which relates to the technical field of shield tunneling construction, and comprises an optical shaft and a smooth shaft section arranged at the middle section of a screw shaft, the cylinder body is sleeved outside the polished shaft, and a slag discharging channel is formed between the cylinder body and the polished shaft; the filling piece is arranged in the cylinder body and can be expanded in the radial direction of the cylinder body to seal the slag discharging channel; and the pressure source is connected with the filling piece to pressurize the filling piece and seal the slag discharging channel. According to the spiral shaft sealing device, spiral blades are not welded to the polished shaft section, muck is not affected by the lead angle on the polished shaft section, the soil plug effect can be formed through passive extrusion on the polished shaft section, and the certain water gushing blocking effect is achieved; when necessary, the space between the filling piece and the barrel is pressurized through the pressure source, the slag discharging channel is closed, the purpose of completely blocking gushing water is achieved, the problem that the internal construction environment of the earth pressure balance shield tunneling machine is polluted by muck gushing in water-rich stratum construction of the earth pressure balance shield tunneling machine can be effectively solved, it is guaranteed that the pressure of an earth bin is stable, and the service life of the earth pressure balance shield tunneling machine is prolonged. And the tunneling safety of equipment is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunneling construction, and in particular to a spiral shaft sealing device. Background Art

[0002] The earth pressure balance shield machine uses an axial or belt screw conveyor to take slag from the bottom of the pressurized soil bin and transfer it to the belt conveyor. However, when the earth pressure balance shield machine passes through water-rich strata, the poor improvement of the slag soil leads to a decrease in water-stopping properties, and a large amount of muddy water and slag gushes out from the slag outlet of the screw conveyor. The slag gushing not only pollutes the internal construction environment of the earth pressure balance shield machine, but also may cause a large-scale decrease in the soil bin pressure, resulting in ground subsidence.

[0003] In the prior art, on the one hand, the technologies of slag improvement, double gates, telescopic function of screw conveyor, pressure-maintaining pump, etc. are widely used, but the effect is not good when dealing with gushing; on the other hand, the technologies of extending the slag discharge path such as double screw conveyor, U-shaped sealed screw machine groove, anti-gushing barrel, etc. are used on a small scale. By adding new devices, the intensity of the gushing can be slowed down or reduced, but the effect is limited for gushing with large water pressure. For example, the patent CN204783040U anti-gushing double screw conveyor, the first-stage screw machine and the second-stage screw machine are connected in series to increase the pitch of the screw shaft, but a new first-stage screw machine needs to be added, the structure is complex, and the anti-gushing effect is limited when facing deep buried water-rich strata. Patent CN110541716B U-shaped sealed screw machine anti-gushing system and anti-gushing method that can separate slag and water, adds a sealing box at the slag outlet, and changes the slag discharge from the large-diameter barrel section to the small-diameter mud and water pipeline, which reduces the slag particle size. Patent CN212173542U is a vacuum water-analysis type anti-gushing screw conveyor and shield machine with a new vacuum cylinder section. When encountering water-rich strata, the vacuum water-analysis mechanism only diverts part of the water, and the slag will block the water-analysis holes, the diversion is limited, and most of the mixed slag and water will still be ejected from the rear slag outlet. Patent CN221196160U is an elastic pressure-stabilizing regulating valve and screw machine anti-gushing system. Although an elastic pressure-stabilizing regulating valve is proposed, the elastic pressure-stabilizing regulating valve is set on the mud pipeline, which solves the emergency drainage problem after the screw conveyor gushes. The mud pipeline and the rear slag outlet are respectively at the tail of the screw conveyor and are independent of each other. The gate of the rear slag outlet must be closed when draining water. At this time, the earth pressure balance shield machine stops excavating, and the screw conveyor stops rotating and discharging slag, affecting construction.

[0004] Therefore, for the construction of shaft screw conveyors in water-rich strata, it is necessary to design an anti-surge screw conveyor with an effectively sealed screw shaft. Summary of the invention

[0005] The object of the present invention is to provide a spiral shaft sealing device, which can effectively deal with the problem of slag gushing during the construction of an earth pressure balance shield machine in a water-rich stratum.

[0006] In order to achieve the above object, a spiral shaft sealing device of the present invention comprises: The optical axis is a smooth shaft section arranged in the middle section of the spiral shaft; A cylinder body is sleeved outside the optical axis, and a slag discharge channel is formed between the cylinder body and the optical axis; A filling member is arranged inside the cylinder and can be expanded radially along the cylinder to close the slag discharge channel; A pressure source is connected to the filling member to pressurize it and close the slag discharge channel.

[0007] Furthermore, the cylinder is provided with an injection hole connected to the pressure source.

[0008] Furthermore, the cylinder is connected to the front section cylinder through a front flange, and to the rear section cylinder through a rear flange, and the front and rear faces of the filling piece are compressed at the connection between the front flange and the rear flange under the action of connecting bolts; or, the front and rear faces of the filling piece are adhered to the inner wall of the cylinder and fixed to the cylinder through bolts; or, the front and rear faces of the filling piece are embedded in the cylinder and fixed to the cylinder through bolts.

[0009] Furthermore, the filling piece adopts a half structure or an integral structure.

[0010] Furthermore, the filling piece is made of a high-strength, deformable material, such as a plastic bag, an airbag, etc.

[0011] Furthermore, the cylinder body adopts a half structure or an integral structure.

[0012] Furthermore, the optical axis adopts a constant diameter axis or a stepped axis.

[0013] Furthermore, the pressure source may be a device for conveying gas or a device for conveying liquid, and the pressure may be air pressure, water pressure, etc.

[0014] The beneficial effects of the present invention are: In the spiral shaft sealing device of the present invention, the middle section of the spiral shaft without welding spiral blades is selected as the smooth shaft section. The slag in the smooth shaft section is not affected by the spiral lead angle and can be passively squeezed in the smooth shaft section to form a soil plug effect, which plays a certain role in blocking water gushing.

[0015] In the spiral shaft sealing device of the present invention, pressure can be continuously injected into the enclosed space between the filling part and the cylinder through a pressure source to close the slag discharge channel, thereby achieving the purpose of completely blocking water gushing. This can not only effectively deal with the problem of slag gushing and polluting the internal construction environment of the earth pressure balance shield machine during construction in water-rich strata, but also ensure the stability of the soil bin pressure, thereby ensuring the safety of equipment excavation.

[0016] In the spiral shaft sealing device of the present invention, the pressure in the filling piece can be adjusted. When the pressure value of the soil plug is greater than the pressure value of the filling piece, the slag discharge channel is opened to discharge slag, and the pressure of the soil bin is dynamically adjusted.

[0017] In the spiral shaft sealing device of the present invention, the slag discharge channel is located on the spiral shaft, and the slag discharge is completed by dynamically adjusting the size of the slag discharge channel. The rear slag discharge port does not need to be closed, and the earth pressure balance shield machine does not need to stop excavation, so continuous construction can be achieved.

[0018] In the spiral shaft sealing device of the present invention, the soil bin excavated by the cutter disc is in a pressurized state. After the slag is transported and depressurized by the screw conveyor, it becomes conveyed at normal pressure. Compared with the continuous spiral blades on the spiral shaft, the spaced spiral blades of the present invention can play a role of step-by-step pressure reduction.

[0019] In the spiral shaft sealing device of the present invention, the size of the parts is small, and it is suitable for the situation where the internal space of the shield is narrow. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the main engine slag discharge system structure of the earth pressure balance shield machine; Figure 2 This is a schematic structural diagram of the spiral shaft sealing device of Example 1; Figure 3 This is a schematic diagram of the structure in which the cylinder and the airbag are both divided into half structures and separated; Figure 4 This is a schematic diagram of the structure in which the cylinder and the airbag of Example 1 are both divided into half structures and connected; Figure 5 This is a schematic diagram of the structure of the airbag pressurization in Example 1; Figure 6 This is a schematic diagram of the structure of Example 1 in which the airbag presses the optical axis and closes the slag discharge channel; Figure 7 This is a schematic diagram of the structure of Example 2 where the airbag is inserted into the cylinder from the injection hole; Figure 8 This is a schematic diagram of the structure in which the optical axis of Example 3 is a stepped axis; Fig. 9 This is a schematic diagram of the structure of Example 4 in which the cylinder and the airbag are both integral structures.

[0021] In the figure: 1-soil bin, 2-partition, 3-shield, 4-slag, 5-slag inlet, 6-screw shaft, 7-sealing part, 8-driving part, 9-slag outlet, 601-front blade segment, 602-middle bladeless segment (optical axis), 603-rear blade segment, 701-front flange, 702-cylinder, 7021-injection hole, 703-rear flange, 704-airbag, 7041-airbag one, 7042-airbag two, 705-half flange, 10-slag outlet channel, 11-front section cylinder, 12-rear section cylinder. DETAILED DESCRIPTION

[0022] The following further describes the structures involved in the present invention or the technical terms used in these descriptions. These descriptions are only used as examples to illustrate how the methods of the present invention are implemented, and cannot constitute any limitation to the present invention.

[0023] In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "lateral", "longitudinal", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limitations of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, unless otherwise clearly specified and limited, "connection", "fixation" and the like should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0025] This embodiment introduces a spiral shaft sealing device, such as Figure 1 As shown, the main slag discharge system of the earth pressure balance shield machine includes a soil bin 1, a partition 2, a shield body 3, slag 4, a slag inlet 5, a screw shaft 6, a sealing part 7, a driving part 8, and a slag outlet 9. The shield machine partition 2 and the tunnel face form a closed soil bin 1 to balance the soil pressure in front and stabilize the stratum. The shaft screw conveyor is installed at the opening at the bottom of the partition 2, takes slag from the pressurized soil bin 1, and continuously reduces it to normal pressure, and sends the slag out from the slag outlet 9 at normal pressure. The shaft screw conveyor includes a screw shaft 6, a sealing part 7, and a driving part 8. The driving part 8 is installed at the tail of the shaft screw conveyor to drive the screw shaft 6 to rotate and take soil from the soil bin 1.

[0026] like Figure 2 As shown, the spiral shaft 6 includes a front blade segment 601, a middle bladeless segment (optical axis) 602, and a rear blade segment 603; the slag 4 can enter from the front blade segment 601, move to the rear under the push of the spiral blades, and form a soil plug in the optical axis segment 602. The middle section of the spiral shaft without welding spiral blades is selected as the optical axis segment 602. The original slag cut by the cutter head is improved to form fluid plastic slag. In the optical axis segment 602, there is no active transportation of spiral blades, and a large amount of slag will accumulate here, eventually forming a soil plug effect, which plays a certain role in blocking water inrush. The slag is still fluid here, the earth pressure balance shield machine is still excavating, the screw conveyor is still continuously conveying slag, and the front of the optical axis segment 602 is still accumulating slag. The front pressure will squeeze the slag at the rear of the optical axis segment into the next section of spiral blades, and then transport it to the slag outlet. Moreover, the soil bin excavated by the cutter disc is in a pressurized state. After the slag is transported and depressurized by the screw conveyor, it becomes transported at normal pressure. Compared with the continuous spiral blades on the spiral shaft, the intermittent spiral blades in this embodiment can play a role in step-by-step pressure reduction.

[0027] like Figure 2 As shown, the sealing part 7 includes a front flange 701, a cylinder 702, a rear flange 703, an airbag 704, and a pressure source. The cylinder 702 is sleeved outside the optical axis 602, and a slag discharge channel 10 is formed between the cylinder 702 and the optical axis 602. The slag discharge is completed by dynamically adjusting the size of the slag discharge channel 10, and the rear slag discharge port does not need to be closed, and the earth pressure balance shield machine does not need to stop excavation, and construction can continue.

[0028] like Figure 2 As shown, the cylinder 702 is connected to the front section cylinder 11 of the shaft screw conveyor through the front flange 701, and is connected to the rear section cylinder 12 of the shaft screw conveyor through the rear flange 702. The front and rear surfaces of the airbag 704 are respectively compressed by the connecting bolts at the connection points of the front flange 701 and the rear flange 703 to form a seal. The cylinder 702 is provided with an injection hole 7021 connected to a pressure source, and gas can be continuously injected into the closed space between the airbag 704 and the cylinder 702 through the pressure source to pressurize the airbag 704.

[0029] like Figure 2 As shown, the optical axis section 602 is a constant diameter axis, which can ensure the passage of large-size slag.

[0030] like Figure 3-4 As shown, the cylinder 702 is a half-structure, connected by a half flange 705, and the airbag 704 is also a half-structure, namely, airbag 1 7041 and airbag 2 7042. The upper and lower connecting parts of airbag 1 7041 and airbag 2 7042 can be tightened under the action of the bolts of the half flange 705.

[0031] The half-structure of the airbag 704 and the cylinder 702 can replace the worn or abnormal airbag under appropriate safety conditions during the excavation of the earth pressure balance shield machine, thereby ensuring the safety and reliability of the sealing part 7.

[0032] In this embodiment, gas can be continuously injected into the enclosed space between the airbag 704 and the cylinder 702 through a pressure source. The airbag 704 continues to expand after being pressurized, and the slag discharge channel 10 is continuously reduced until the airbag 704 is tightly fitted with the optical axis 602. The slag discharge channel 10 can be completely closed, thereby achieving the purpose of completely blocking the gushing water. This can not only effectively deal with the problem of slag gushing and polluting the internal construction environment of the earth pressure balance shield machine during construction in water-rich strata, but also ensure the stability of the soil bin pressure, thereby ensuring the safety of equipment excavation.

[0033] In this embodiment, the pressure in the airbag 704 can be adjusted. When the pressure value of the soil plug is greater than the pressure value of the airbag 704, the slag discharge channel 10 is opened to discharge the slag, and the pressure of the soil bin is dynamically adjusted.

[0034] The working process of the spiral shaft sealing device of this embodiment is as follows: Figure 4-6 As shown: S1: The screw shaft 6 is rotated to remove slag under the action of the rear driving part 8; S2: It is detected that the formation is rich in water, and gas begins to be injected from the injection hole 7021; S3: The airbag 704 expands continuously under the pressure, and continuously closes the slag discharge channel 10; S4: The airbag 704 presses the optical axis 602 under pressure, completely closing the slag discharge channel 10. Example 2

[0035] The difference between this embodiment and embodiment 1 is that the airbag 704 is inserted into the cylinder 702 from the injection hole 7021, and only a reduced space airbag is formed inside. The edge of the airbag 704 is turned outward to the outside of the cylinder 702 and fixed to the cylinder 702 by bolts. An airbag 704 is arranged above and below the cylinder 702. Figure 7 . The rest is the same as Example 1. Example 3

[0036] The difference between this embodiment and embodiment 1 is that the optical axis 602 is a stepped axis, and the diameter of the optical axis 602 is larger than the diameters of the axis segments on both sides thereof, which can improve the strength of the axis. Figure 8 . The rest is the same as Example 1. Example 4

[0037] The difference between this embodiment and embodiment 1 is that the cylinder 702 and the airbag 704 are both integrally structured, with good sealing effect. Fig. 9 . The rest is the same as Example 1.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A spiral shaft sealing device, characterized in that: include: The optical axis is a smooth shaft section arranged in the middle section of the spiral shaft; A cylinder body is sleeved outside the optical axis, and a slag discharge channel is formed between the cylinder body and the optical axis; A filling member is arranged inside the cylinder and can be expanded radially along the cylinder to close the slag discharge channel; A pressure source is connected to the filling member to pressurize it and close the slag discharge channel.

2. The spiral shaft sealing device according to claim 1, characterized in that: The cylinder is provided with an injection hole connected to the pressure source.

3. The spiral shaft sealing device according to claim 2, characterized in that: The cylinder is connected to the front section cylinder through a front flange and to the rear section cylinder through a rear flange. The front and rear faces of the filling piece are compressed at the connection between the front flange and the rear flange under the action of connecting bolts; or the front and rear faces of the filling piece are adhered to the inner wall of the cylinder and fixed to the cylinder through bolts; or the front and rear faces of the filling piece are embedded in the cylinder and fixed to the cylinder through bolts.

4. The spiral shaft sealing device according to claim 3, characterized in that: The filling piece adopts a half structure or an integral structure.

5. The spiral shaft sealing device according to claim 2, characterized in that: The filling piece is inserted into the cylinder from the injection hole, the edge of the filling piece is turned outward to the outside of the cylinder and is fixed to the cylinder by bolts, and a filling piece is arranged at the top and the bottom of the cylinder.

6. The spiral shaft sealing device according to any one of claims 1 to 5, characterized in that: The cylinder body adopts a half structure or an integral structure.

7. The spiral shaft sealing device according to any one of claims 1 to 5, characterized in that: The filling piece is a plastic bag or an air bag.

8. The spiral shaft sealing device according to any one of claims 1 to 5, characterized in that: The optical axis is a constant diameter axis or a stepped axis.

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