Mechanical spiral shaft sealing device

Abstract

The invention discloses a mechanical spiral 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 spiral 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 sealing 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 gate movably penetrates into the cylinder body to fold and unfold the sealing piece. According to the mechanical spiral shaft sealing device, spiral blades are not welded to the polished shaft section, muck is not affected by a lead angle on the polished shaft section, the muck can be passively extruded on the polished shaft section, the soil plug effect is formed, and a certain water gushing blocking effect is achieved; when necessary, the gate and the deslagging channel can be 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 the water-rich stratum construction of the earth pressure balance shield tunneling machine can be effectively solved, the pressure stability of an earth bin is guaranteed, and then the tunneling safety of equipment is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunneling construction, and in particular to a mechanical 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 mechanical 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 mechanical 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 closing member, arranged inside the cylinder, and capable of being expanded radially along the cylinder to close the slag discharge channel; The gate can be movably inserted into and out of the cylinder to allow the closure to be retracted and extended.

[0007] 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 closure member 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 closure member are embedded in the cylinder and fixed to the cylinder by bolts, or, the front and rear faces of the closure member are adhered to the inner wall of the cylinder and fixed to the cylinder by bolts.

[0008] Furthermore, the cylinder body adopts an integral structure or a half structure.

[0009] Furthermore, the closure is made of a material with high strength, good wear resistance and can be deformed, such as a plastic bag, an air bag, etc. The shape of the closure can be cylindrical, square column, etc.

[0010] Furthermore, the closure member adopts an integral structure or a split-half structure. The structures of the cylinder and the closure member can be in various combinations, including: the cylinder adopts an integral structure and the closure member adopts an integral structure; the cylinder adopts an integral structure and the closure member adopts a split-half structure; the closure member adopts a split-half structure and the cylinder adopts a split-half structure; the cylinder adopts a split-half structure and the closure member adopts an integral structure.

[0011] Furthermore, the gate is made of a high-strength material with a certain thickness and can withstand high-pressure gushing.

[0012] Furthermore, the gates are in two symmetrical groups, and each group of the gates is connected to a pushing device for pushing the gates to move.

[0013] Furthermore, the pushing device comprises a screw, a threaded sleeve and a rotating wheel, wherein the screw is fixed to the gate, the threaded sleeve and the screw form a spiral motion pair, and the rotating wheel is fixed to the threaded sleeve. The rotating wheel can be a manual rotating wheel or an electric rotating wheel.

[0014] Alternatively, the pushing device comprises a transverse plate and two groups of oil cylinders, wherein the transverse plate is fixed to the gate, the oil cylinders are respectively arranged on both sides of the transverse plate, and the ends of the oil cylinder piston rods are fixed to the transverse plate.

[0015] The beneficial effects of the present invention are: In the mechanical 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.

[0016] In the mechanical spiral shaft sealing device of the present invention, the gate can be closed and the slag discharge channel can be sealed to achieve the purpose of completely blocking the water gushing. It 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.

[0017] In the mechanical spiral shaft sealing device of the present invention, the gate can be stopped at any position, so the opening of the slag discharge channel can be quantitatively selected according to needs, the size of the slag discharge channel can be dynamically adjusted, and then the slag discharge particle size can be adjusted to control the soil bin pressure.

[0018] In the mechanical 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 that the construction can be carried out continuously.

[0019] In the mechanical 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 intermittent spiral blades of the present invention can play a role of step-by-step pressure reduction.

[0020] In the mechanical spiral shaft sealing device of the present invention, the gate has strong anti-punch performance, can cope with high-pressure gushing, and is combined with the sealing member to form a strong sealing structure.

[0021] In the mechanical spiral shaft sealing device of the present invention, if the cylinder and the sealing member both adopt a half-structure, the sealing member can be easily replaced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 plastic bag is closely attached to the inner wall of the cylinder in Example 1; Figure 4 This is a schematic diagram of the structure in which the cylinder and the plastic bag are divided into half structures and connected; Figure 5 This is a schematic diagram of the structure of the plastic bag of Example 1 which is a half-structure; Figure 6 This is a schematic diagram of the structure in which the cylinder of Example 1 is a half-structure and separated; Figure 7 This is a schematic diagram of the structure of the pushing device of Example 1; Figure 8 This is a structural schematic diagram of the gate beginning to close in Example 1; Fig. 9 This is a structural schematic diagram of the gate gradually closing in Example 1; Fig.10 This is a schematic diagram of the structure of the gate in Example 1 when it is completely closed; Fig.11 This is a schematic diagram of the structure of the propulsion device using an oil cylinder in Example 2; Fig.12 This is a schematic diagram of the structure of the plastic bag as a whole in Example 3; Fig.13 This is a schematic diagram of the structure of the cylinder and the plastic bag as a whole in Example 3.

[0023] 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-barrel, 703-rear flange, 704-plastic bag, 7041-upper plastic bag, 7042-lower plastic bag, 705-gate, 7051-upper gate, 7052-lower gate, 706-pushing device, 7061-screw, 7062-threaded sleeve, 7063-manual rotating wheel, 707-half flange, 708-cross plate, 709-oil cylinder, 10-slag outlet channel, 11-front section barrel, 12-rear section barrel. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] 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

[0027] This embodiment introduces a mechanical 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 partition 2 of the earth pressure balance shield machine and the tunnel face form a closed soil bin 1, which balances the soil pressure in front and stabilizes 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 screw conveyor, driving the screw shaft 6 to rotate and take soil from the soil bin 1.

[0028] 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.

[0029] like Figure 2-3As shown, the sealing part 7 includes a front flange 701, a cylinder 702, a rear flange 703, a plastic bag 704, a gate 705, and a pushing device 706; 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 plastic bag 704 can be continuously expanded and blocked by the gate 705 under the action of the gate 705. When the gate 705 is completely closed, it is close to the optical axis section 602 to close the slag discharge channel 10. The gate 705 has strong anti-punching performance and can cope with high-pressure gushing. It is combined with the plastic bag 704 to form a strong sealing structure. The position of the slag discharge channel 10 is set on the spiral shaft 6. The slag discharge is completed by dynamically adjusting the size of the slag discharge channel 10. 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 be continued.

[0030] like Figure 3 As shown, the cylinder 702 is connected to the front cylinder section 11 of the axial screw conveyor through the front flange 701, and is connected to the rear cylinder section 12 of the axial screw conveyor through the rear flange 703. The plastic bag 704 is tightly attached to the inner wall of the cylinder 702, and its front and rear faces are compressed at the connection between the front flange 701 and the rear flange 703 by the action of the connecting bolts to form a seal.

[0031] like Figure 4-5 As shown, the cylinder 702 adopts an upper and lower half structure, which is connected by a half flange 707. The plastic bag 704 also adopts an upper and lower half structure, including an upper plastic bag 7041 and a lower plastic bag 7042. The plastic bag 704 is compressed at the connection of the half flange 707 by the action of the connecting bolts to form a closure.

[0032] like Figure 6-7 As shown, the gate 705 is composed of an upper gate 7051 and a lower gate 7052, each gate is provided with a push device 706, the push device 706 includes a screw 7061, a threaded sleeve 7062 and a manual rotating wheel 7063, the threaded sleeve 7062 is fixed to the outer wall of the cylinder 702, the screw 7061 is fixed to the gate, the threaded sleeve 7062 and the screw 7061 form a spiral motion pair, and the manual rotating wheel 7063 is fixed to the threaded sleeve 7062. The cylinder 702 is provided with an opening in the circumference, and the gate 705 passes through the opening to exit the cylinder 702. The area of ​​the two groups of gates 705 is not less than the cross-sectional area of ​​the cylinder 702, that is, the circular area, so that the two groups of gates 705 can completely close the slag discharge channel 10.

[0033] The half-structure of the cylinder 702 and the plastic bag 704 can replace the worn or abnormal plastic bag under appropriate safety conditions during shield machine excavation, thereby ensuring the safety and reliability of the sealing part 7.

[0034] In this embodiment, the manual rotating wheel 708 can be driven by manpower to drive the screw 704 to close the gate 705. The gate 705 continuously tightens the plastic bag 704 until it is completely close to the optical axis 602, closing the slag discharge channel 10, thereby achieving the purpose of completely blocking the 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.

[0035] In this embodiment, the screw conveyor sealing device composed of the gate 707, the plastic bag 704 and the optical axis 602, the plastic bag 704 can be stopped at any position with the gate 705, so the opening of the slag discharge channel 10 can be quantitatively selected according to needs, the size of the slag discharge channel 10 can be dynamically adjusted, and then the slag particle size can be adjusted to control the soil bin pressure.

[0036] The working process of the mechanical spiral shaft sealing device of the present invention is as follows: Figure 8-10 As shown: S1: The screw shaft 6 is rotated to remove slag under the action of the rear driving part 8; S2: rich water in the formation is detected, the rotating wheel 7063 is manually driven, and the gate 705 is closed; S3: The plastic bag 704 continues to expand under the action of the gate 705, and the slag discharge channel 10 continues to shrink; S4: As the gate 705 is completely closed, the plastic bag 704 presses the optical axis 602 to completely close the slag discharge channel 10. Example 2

[0037] The difference from Example 1 is that the pushing device includes a horizontal plate 708 and two sets of oil cylinders 709. The horizontal plate 708 is fixed on the top of the gate 705. The oil cylinders 709 are respectively arranged on both sides of the horizontal plate 708. The ends of the piston rods are fixed to the horizontal plate 708 to drive the gate 705 to close up and down. Fig.11 . The rest is the same as Example 1. Example 3

[0038] The difference from Example 1 is that the cylinder 702 and the plastic bag 704 are both integral structures, see Figure 12-13 . The rest is the same as Example 1.

[0039] 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 mechanical helical 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 closing member, arranged inside the cylinder, which can be expanded radially along the cylinder to close the slag discharge channel; The gate can be movably inserted into and out of the cylinder to allow the closure to be retracted and extended.

2. The mechanical helical shaft sealing device according to claim 1, characterized in that: The cylinder body is connected to the front section cylinder through the front flange and to the rear section cylinder through the rear flange. The front and rear faces of the closure member are compressed at the connection between the front flange and the rear flange under the action of the connecting bolts.

3. The mechanical helical shaft sealing device according to claim 1, characterized in that: The front and rear faces of the closure are embedded in the cylinder and fixed on the cylinder by bolts.

4. The mechanical helical shaft sealing device according to claim 1, characterized in that: The front and rear surfaces of the closure are adhered to the inner wall of the cylinder and fixed to the cylinder by bolts.

5. The mechanical helical shaft sealing device according to claim 1, characterized in that: The cylinder body adopts an integral structure or a half structure.

6. The mechanical helical shaft sealing device according to claim 1, characterized in that: The sealing member is a plastic bag or an air bag.

7. The mechanical helical shaft sealing device according to claim 1, characterized in that: The closure member adopts an integral structure or a half structure.

8. The mechanical helical shaft sealing device according to claim 1, characterized in that: The gates are divided into two symmetrical groups, and each group of gates is connected with a pushing device for pushing the gates to move.

9. The mechanical helical shaft sealing device according to claim 8, characterized in that: The pushing device comprises a screw rod, a threaded sleeve and a rotating wheel. The end of the screw rod is fixed to the gate. The threaded sleeve and the screw rod form a spiral motion pair. The rotating wheel is fixed to the threaded sleeve.

10. The mechanical helical shaft sealing device according to claim 8, characterized in that: The pushing device comprises a transverse plate and two groups of oil cylinders. The transverse plate is fixed to the gate. The oil cylinders are respectively arranged on both sides of the transverse plate. The ends of the oil cylinder piston rods are fixed to the transverse plate.

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