Sealing elements and submerged pump systems

Abstract

To provide a sealing member and a submerged pump system capable of suppressing leakage of residual gas when raising and lowering a pump.SOLUTION: A sealing member 3 seals an opening end 2a of a pump column 2 and hangs and supports a pump when raising and lowering the pump. The sealing member has a head plate 10 that has a through-hole 11 and is attached to an opening end, a lift shaft 20 that penetrates the through-hole and is raised and lowered between an ascending position and a descending position when raising and lowering the pump, and a bellows member 30 that expands / contracts according to the raising and lowering of the lift shaft. The bellows member is equipped with a bellows cylinder body 31 that covers an outer peripheral surface of a projecting part projecting downward from the head plate in the lift shaft, a first attaching member 32 that is disposed continuously to a lower end 31a of the bellows cylinder body and is attached to a projecting lower part, and a second attaching member 33 that is disposed continuously to an upper end 31b of the bellows cylinder body and is attached to a lower surface 10b of the head plate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sealing member and a submerged pump system. [Background technology]

[0002] Submerged pumping systems are used to extract liquefied gas (such as liquefied natural gas or liquefied ammonia) from a storage tank in which the gas is stored (see, for example, Patent Document 1). The pump (submerged pump) of the submerged pumping system is housed in a pump column that extends from the ceiling of the storage tank into the liquefied gas and is immersed in the liquefied gas. A foot valve that opens under the pump's own weight is attached to the lower end of the pump column. The upper end of the pump column is liquid-tightly sealed by a head plate. A lift shaft that raises and lowers the pump is attached to the head plate and passes through the head plate. The space between the lift shaft and the head plate is liquid-tightly sealed by a sealing material (for example, a gland seal).

[0003] In a submerged pump system, the pump is removed from the storage tank for maintenance, for example. When the pump is stopped, the pump column is filled with residual liquefied gas and vaporized liquefied gas (vaporized gas). If the head plate is removed in this state, there is a technical problem in that the liquefied gas and vaporized gas (hereinafter collectively referred to as "residual gas") leak to the outside. Since most residual gases are flammable and / or toxic, they must be removed before the head plate is removed.

[0004] Residual gas is typically removed by introducing an inert gas, such as nitrogen, into the pump column with the foot valve closed. In this method, the pump is lifted by the lift shaft and the foot valve is closed before the inert gas is introduced. At this time, the lift shaft is raised to close the foot valve, which loosens the sealant beforehand. This weakens the sealant's sealing ability, potentially allowing a small amount of residual gas to leak through gaps in the sealant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-132619 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a sealing member and a submerged pump system that can suppress leakage of residual gas when the pump is raised and lowered. [Means for solving the problem]

[0007] In one embodiment of the present invention, the sealing member seals an open end of a cylindrical pump column that houses a pump that is immersed in pumped liquid, and suspends and supports the pump when the pump is raised and lowered within the pump column, the sealing member comprising: a head plate having a through hole extending in the vertical direction and attached to the open end so as to close the open end; a lift shaft that is disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered; and a bellows member that expands and contracts in the axial direction of the lift shaft in response to the raising and lowering of the lift shaft. a lower housing covering a portion of the bellows member; The bellows member comprises a bellows cylindrical body covering an outer peripheral surface of a protruding lower portion of the lift shaft that protrudes downward from the head plate, a first mounting member disposed contiguous with a lower end of the bellows cylindrical body and attached to the protruding lower portion of the lift shaft, and a second mounting member disposed contiguous with an upper end of the bellows cylindrical body and attached to the lower surface of the head plate. The lower housing includes an inner flange portion facing the lower surface of the first mounting member, covers the outer peripheral surface of the bellows cylindrical body and the outer peripheral surface of the first mounting member, and is attached to the lower surface of the head plate or the lower surface of the second mounting member. .

[0008] One implementation of the present invention Aspects The submerged pump system in the above comprises a pump that is immersed in the pumped liquid, a cylindrical pump column that houses the pump, and the sealing member. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a sealing member and a submerged pump system that can suppress leakage of residual gas when the pump is raised and lowered. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing a first embodiment of a submerged pump system according to the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a sealing member in the first embodiment. [Figure 3] FIG. 3 is a schematic exploded cross-sectional view of the sealing member of FIG. 2. [Figure 4] 3 is a schematic cross-sectional view of the sealing member shown in FIG. 2 when a lift shaft of the sealing member is located at a raised position. [Figure 5] FIG. 4 is a schematic cross-sectional view showing a second embodiment of a submerged pump system according to the present invention. [Figure 6] FIG. 10 is a schematic cross-sectional view showing a sealing member according to a second embodiment. [Figure 7] FIG. 7 is a schematic exploded cross-sectional view of the sealing member of FIG. 6. [Figure 8] 7 is a schematic cross-sectional view of the sealing member shown in FIG. 6 when a lift shaft provided in the sealing member is located at a raised position. [Figure 9] 7(a) is a schematic plan view showing a first modified example of a first mounting member provided in the sealing member of FIG. 6, and FIG. 7(b) is a schematic plan view showing a second modified example of the first mounting member. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a sealing member and a submerged pump system according to the present invention will be described with reference to the drawings. In each drawing, the same members and elements are designated by the same reference numerals, and duplicated explanations will be omitted. In addition, in each drawing, the shape and size of each member are intentionally exaggerated compared to their actual dimensions in order to clarify the configuration of each member.

[0012] In the following description and drawings, "downward" refers to the direction of gravity, and "upward" refers to the opposite direction of downward.

[0013] ●Submerged Pump System(1)● First, an embodiment (first embodiment) of a submerged pump system according to the present invention will be described.

[0014] ●Configuration of Submerged Pump System (1) FIG. 1 is a schematic cross-sectional view showing a first embodiment of a submerged pump system according to the present invention.

[0015] The submerged pump system 1 is attached to a storage tank T in which liquefied gas Lg is stored, and pumps the liquefied gas Lg from the storage tank T to the outside. The submerged pump system 1 includes a pump column 2, a sealing member 3, a support cable 4, a submerged pump (hereinafter referred to as "pump") 5, a foot valve 6, and a collar 7. In this embodiment, the liquefied gas Lg is liquefaction Ammonia. Liquefied ammonia is an example of the handled liquid in the present invention.

[0016] In the present invention, the handled liquid is not limited to liquefied ammonia, and may be, for example, liquefied natural gas.

[0017] The pump column 2 houses the pump 5 and functions as a liquid transport path for the liquefied gas Lg discharged from the pump 5. The pump column 2 is cylindrical in shape. The pump column 2 is disposed so as to penetrate the ceiling T1 of the storage tank T and extends from the ceiling T1 into the liquefied gas Lg. A liquid transport path R1 for the liquefied gas Lg is connected to the outer peripheral surface of the upper part of the pump column 2.

[0018] The sealing member 3 liquid-tightly seals the upper open end 2a of the pump column 2, and also suspends and supports the pump 5 via the support cable 4 when the pump 5 is raised and lowered within the pump column 2. The sealing member 3 is one example of a sealing member according to the present invention, and its specific configuration will be described later.

[0019] The support cable 4 suspends and supports the pump 5 when the pump 5 is raised and lowered within the pump column 2. The support cable 4 is made of, for example, a metal wire. The support cable 4 is connected to the lift shaft 20 (described later) and the pump 5.

[0020] The pump 5 discharges the liquefied gas Lg that has flowed in through the foot valve 6 into the pump column 2. The pump 5 is, for example, a known submerged pump that is composed of a multi-stage centrifugal pump and a motor that drives the multi-stage centrifugal pump. Power for the pump 5 is supplied via a power cable (not shown) that is connected to the sealing member 3. The pump 5 is housed in the lower part of the pump column 2 and is immersed in the liquefied gas Lg.

[0021] The foot valve 6 opens and closes the lower open end 2b of the pump column 2. The foot valve 6 opens due to the weight of the pump 5 when the pump 5 is housed in the lower part of the pump column 2, and closes due to the biasing force of a spring (not shown) when the pump 5 is lifted up.

[0022] The collar 7 fixes the lift shaft 20, which will be described later, in an elevated position, which will be described later. The collar 7 is cylindrically configured with two semi-cylindrical members 7a and 7b. That is, the collar 7 can be disassembled into the two semi-cylindrical members 7a and 7b. The collar 7 is a maintenance member that is used when the pump 5 is removed, and is not used while the pump 5 is in operation. For this reason, the collar 7 is shown in dashed lines in FIGS. 1 and 5.

[0023] ●Configuration of sealing member (1) Next, a specific configuration of the sealing member 3 (the sealing member according to the present invention) will be described.

[0024] FIG. 2 is a schematic cross-sectional view showing the sealing member 3 in the first embodiment. FIG. 3 is a schematic exploded cross-sectional view of the sealing member 3. As shown in FIG. Fig. 2 shows the sealing member 3 when a lift shaft 20 (described later) is in the lowered position. For ease of explanation, Fig. 2 also shows the upper part of the pump column 2. In the following explanation, bolt holes corresponding to bolts B1 to B5 (described later) are well known, and therefore will not be described here. In the following explanation, Fig. 1 will be referenced as appropriate.

[0025] The "lowered position" is a position where the lift shaft 20 is lowered and its downward movement is restricted (the position shown in FIGS. 2 and 6). In this embodiment, the lowered position is a position where the downward movement of the lift shaft 20 is restricted by a lowering restriction member, which will be described later. The "raised position" is a position where the lift shaft 20 is raised and the collar 7 can be attached to the sealing member 3 (the position shown in FIGS. 4 and 6). 8 (The position shown in Figure 1).

[0026] The sealing member 3 includes a head plate 10, a lift shaft 20, a bellows member 30, a first sealing member 40, a second sealing member 50, an upper housing 60, a third sealing member 70, a shaft fixing member 80, a plurality of plate mounting bolts B1, a plurality of bellows mounting bolts B2, a plurality of housing mounting bolts B3, a plurality of lid mounting bolts B4, and a plurality of pressure bolts B5.

[0027] The head plate 10 functions as a lid that closes the upper open end 2a of the pump column 2. The head plate 10 is, for example, disk-shaped. The head plate 10 is made of metal such as stainless steel. The head plate 10 has an insertion hole 11, a seal groove 12, and an insertion portion 13.

[0028] The insertion hole 11 is a through-hole that penetrates the head plate 10 in the up-down direction. That is, the insertion hole 11 extends in the up-down direction in the head plate 10. The insertion hole 11 is disposed in the center of the head plate 10. The insertion hole 11 is an example of a through-hole in the present invention. The insertion hole 11 includes a first hole portion 11a, a second hole portion 11b, and an insertion portion 13.

[0029] The first hole 11a is a circular hole into which the lower part of a first shaft portion 21 (described later) of the lift shaft 20 is inserted when the lift shaft 20 is in the lowered position. The second hole 11b is a circular hole into which a second shaft portion 22 (described later) of the lift shaft 20 is inserted. The first hole 11a is disposed above the second hole 11b and continuous with the second hole 11b. The first hole 11a is disposed concentrically with the second hole 11b. The inner diameter of the first hole 11a is larger than the inner diameter of the second hole 11b.

[0030] The seal groove 12 is a ring-shaped groove in which the second seal member 50 is disposed. The seal groove 12 is disposed concentrically with the first hole portion 11a in the bottom surface 11d of the first hole portion 11a.

[0031] The fitting portion 13 is a recess into which a second mounting member 33 of the bellows member 30, which will be described later, is fitted. The fitting portion 13 is formed by a cylindrical recess in the area of ​​the lower surface 10b of the head plate 10 adjacent to the insertion hole 11, and a ring-shaped recess in the area adjacent to the recess. In other words, the fitting portion 13 is formed by a part of the lower surface 10b, and Insertion hole 11. In the vertical direction, the length (depth) of the cylindrical recess is greater (deeper) than the length (depth) of the ring-shaped recess.

[0032] The lift shaft 20 is raised and lowered between a raised position and a lowered position when the pump 5 is raised and lowered, and supports the pump 5 via the support cable 4. The lift shaft 20 includes a first shaft portion 21, a second shaft portion 22, a first connecting member 23, a second connecting member 24, a first nut member 25, and a second nut member 26.

[0033] The first shaft 21 restricts the lift shaft 20 from moving downward beyond its lowered position. The second shaft 22, together with the second hole 11b of the head plate 10 and a cylindrical portion 33a (described later), guides the lift shaft 20 as it moves up and down. The first shaft 21 and the second shaft 22 are cylindrical and elongated in the vertical direction. The first shaft 21 is disposed above and continuous with the second shaft 22 and is integrally formed with the second shaft 22. That is, the first shaft 21 and the second shaft 22 form a single shaft. The first shaft 21 is disposed concentrically with the second shaft 22. The outer diameter of the first shaft 21 is larger than the outer diameter of the second shaft 22 and slightly smaller than the inner diameter of the first hole 11a. The outer diameter of the second shaft 22 is slightly smaller than the inner diameter of the second hole 11b and the cylindrical portion 33a.

[0034] The first shaft portion 21 has a female screw hole 21a that extends in the vertical direction and opens to an upper end surface 21b of the first shaft portion 21.

[0035] The second shaft portion 22 has a first female screw hole 22a. The first female screw hole 22a extends in the vertical direction and opens to a lower end surface 22b of the second shaft portion 22.

[0036] The first connecting member 23 is a member to which a cable (not shown) from a lift (not shown) is connected when the pump 5 is raised or lowered. The first connecting member 23 includes a ring-shaped connecting portion 23a and a male threaded portion 23b extending downward from the connecting portion 23a. The male threaded portion 23b is threadedly engaged with the female threaded hole 21a, whereby the first connecting member 23 is attached to the upper end of the first shaft portion 21.

[0037] The second connecting member 24 is a member to which the support cable 4 is connected. The second connecting member 24 includes a ring-shaped connecting portion 24a and an externally threaded portion 24b extending upward from the connecting portion 24a. The second connecting member 24 is attached to the lower end of the second shaft portion 22 by threading the externally threaded portion 24b into the first internally threaded hole 22a.

[0038] The first nut member 25 fixes a receiving member 81 (described later) to the upper end surface 21b of the first shaft portion 21. The first nut member 25 is attached to the male thread portion 23b of the first connecting member 23.

[0039] The second nut member 26 presses the first mounting member 32 (described later) against the lower end surface 22b of the second shaft portion 22. The second nut member 26 is attached to the male thread portion 24b of the second connecting member 24.

[0040] The lift shaft 20 is inserted from above into the insertion hole 11 of the head plate 10 and is disposed so as to pass through the insertion hole 11. The lift shaft 20 can be raised and lowered between a lowered position and an raised position when the pump 5 is raised and lowered.

[0041] When the lift shaft 20 is in the lowered position, the lower portion of the first shaft portion 21 is inserted into the first hole portion 11a, and the second shaft portion 22 is inserted through the second hole portion 11b and the cylindrical portion 33a. At this time, the first shaft portion 21 protrudes upward from the head plate 10, and the second shaft portion 22 protrudes downward from the head plate 10 (into the pump column 2). On the other hand, when the lift shaft 20 is in the raised position, the first shaft portion 21 is located above the head plate 10. The second shaft portion 22 is inserted through the first hole portion 11a, the second hole portion 11b, and the cylindrical portion 33a, and protrudes in the vertical direction from the head plate 10.

[0042] The bellows member 30 expands and contracts in the axial direction (vertical direction) of the lift shaft 20 in response to the elevation of the lift shaft 20, and provides a liquid-tight seal between the head plate 10 and the lift shaft 20. The bellows member 30 includes a bellows cylindrical body 31, a first mounting member 32, and a second mounting member 33.

[0043] The bellows cylindrical body 31 expands and contracts in response to the elevation of the lift shaft 20. The bellows cylindrical body 31 is a cylindrical bellows with ring-shaped peaks and valleys that are continuous in the vertical direction. The bellows cylindrical body 31 is made of a metal such as stainless steel. The inner diameter of the bellows cylindrical body 31 (the inner diameter of the valleys) is larger than the outer diameter of the second shaft portion 22 of the lift shaft 20.

[0044] The first mounting member 32 mounts the bellows cylindrical body 31 to the lift shaft 20 (the protruding lower portion described below). The first mounting member 32 is disposed below the bellows cylindrical body 31, continuous with the lower end 31a of the bellows cylindrical body 31. The first mounting member 32 is shaped like a ring plate. The first mounting member 32 has an insertion hole 32a and a seal groove 32b. The outer diameter of the first mounting member 32 is larger than the outer diameter of the bellows cylindrical body 31.

[0045] The insertion hole 32a is a through-hole that passes through the first mounting member 32 in the vertical direction. The insertion hole 32a is disposed in the center of the first mounting member 32. The inner diameter of the insertion hole 32a is smaller than the outer diameter of the second shaft portion 22 and larger than the outer diameter of the male thread portion 24b of the second connecting member 24.

[0046] The seal groove 32b is a ring-shaped groove in which the first seal member 40 is disposed. The seal groove 32b is disposed on the upper surface 32c of the first mounting member 32 concentrically with the insertion hole 32a.

[0047] The second mounting member 33 mounts the bellows cylindrical body 31 to the head plate 10. The second mounting member 33 is disposed above the bellows cylindrical body 31, continuous with the upper end 31b of the bellows cylindrical body 31. The second mounting member 33 includes a cylindrical portion 33a and a flange portion 33b.

[0048] The cylindrical portion 33a has a cylindrical shape. The inner diameter of the cylindrical portion 33a is approximately the same as the inner diameter of the second hole portion 11b. The dimensional tolerance (gap) of the inner diameter of the cylindrical portion 33a relative to the outer diameter of the lift shaft 20 (second shaft portion 22) is smaller than the dimensional tolerance of the inner diameter of the second hole portion 11b. As a result, the second shaft portion 22 is guided by the cylindrical portion 33a, allowing the lift shaft 20 to move up and down smoothly without rattle. In the radial direction of the cylindrical portion 33a, the lower half of the cylindrical portion 33a protrudes outward to form a ring-shaped flange portion 33b. In other words, the cylindrical portion 33a and the flange portion 33b are integrally molded. The outer diameter of the second mounting member 33 (the outer diameters of the cylindrical portion 33a and the flange portion 33b) is approximately the same as the inner diameter of the fitting portion 13 of the head plate 10 (the fitting tolerance is large).

[0049] The lower end 31a of the bellows tubular body 31 is liquid-tight welded to the upper surface 32c of the first mounting member 32 around the entire circumferential circumference of the bellows tubular body 31. The upper end 31b of the bellows tubular body 31 is liquid-tight welded to the lower surface 33c of the second mounting member 33 around the entire circumferential circumference of the bellows tubular body 31. As a result, the bellows tubular body 31, the first mounting member 32, and the second mounting member 33 are integrally configured. In the radial direction of the first mounting member 32, the seal groove 32b is positioned inward of the lower end 31a of the bellows tubular body 31.

[0050] The bellows tubular body 31 is attached to the underside 10b of the head plate 10 by fluid-tightly fitting the second mounting member 33 into the fitting portion 13. The second mounting member 33 is pressed toward the head plate 10 by the bellows mounting bolt B2. The bellows tubular body 31 houses a portion of the lift shaft 20 that protrudes downward from the head plate 10 (hereinafter referred to as the "protruding lower portion") and covers its outer circumferential surface. The protruding lower portion is part of the second shaft portion 22, and its length changes in response to the elevation of the lift shaft 20. A space surrounded by the bellows tubular body 31 (hereinafter referred to as the "bellows internal space S") is formed between the bellows tubular body 31 and the lift shaft 20. The bellows internal space S allows for fluctuations in the inner diameter (outer diameter) of the bellows tubular body 31 as the bellows tubular body 31 expands and contracts.

[0051] The male thread portion 24b of the second connecting member 24 is inserted into the insertion hole 32a. The second nut member 26 and the connecting portion 24a of the second connecting member 24 are disposed below the first mounting member 32. When the second nut member 26, which is in contact with the lower surface 32d of the first mounting member 32, is tightened, the first mounting member 32 is pressed upward (toward the second shaft portion 22) and attached to the lower end surface 22b of the second shaft portion 22 (the protruding lower portion).

[0052] The first seal member 40 is, for example, an O-ring made of fluororesin. The first seal member 40 is disposed in the seal groove 32b of the first mounting member 32. The first seal member 40 is disposed between the lower end surface 22b of the second shaft portion 22 and the upper surface 32c (seal groove 32b) of the first mounting member 32, and provides a liquid-tight seal between them. The sealing performance of the first seal member 40 is determined by the tightening force of the second nut member 26. That is, when the second nut member 26 is loosened, the sealing performance decreases, and when the second nut member 26 is tightened, the sealing performance improves. The first seal member 40 is an example of a bellows seal member according to the present invention.

[0053] The second seal member 50 is, for example, an O-ring made of fluororesin. The second seal member 50 is disposed in the seal groove 12 of the head plate 10. When the lift shaft 20 is in the lowered position, the second seal member 50 is disposed between the bottom surface 11d (seal groove 12) of the first hole portion 11a and the lower end surface 21c of the first shaft portion 21, and provides a liquid-tight seal therebetween. The sealing performance of the second seal member 50 is determined by the tightening force of the pressing bolt B5, which will be described later. That is, when the pressing bolt B5 is loosened, the sealing performance decreases, and when the pressing bolt B5 is tightened, the sealing performance improves. The second seal member 50 is an example of a shaft seal member according to the present invention.

[0054] When the lift shaft 20 is in the lowered position, the upper housing 60 accommodates the portion of the lift shaft 20 that protrudes upward from the head plate 10 (hereinafter referred to as the "protruding upper portion"). The protruding upper portion is the first shaft portion 21. The upper housing 60 includes a cylindrical portion 61, a first flange portion 62, a second flange portion 63, a lid portion 64, and a seal groove 65.

[0055] The cylindrical portion 61 is cylindrical in shape. The inner diameter of the cylindrical portion 61 is larger than the outer diameter of the first shaft portion 21 and smaller than the outer diameter of the collar 7. In the radial direction of the cylindrical portion 61, the upper end of the cylindrical portion 61 protrudes outward to form a ring-shaped first flange portion 62. The lower end of the cylindrical portion 61 protrudes outward to form a ring-shaped second flange portion 63. In other words, the cylindrical portion 61, the first flange portion 62, and the second flange portion 63 are integrally molded.

[0056] The lid portion 64 protects the inside of the cylindrical portion 61 from wind, rain, etc. The lid portion 64 is hat-shaped. The lid portion 64 is fastened to the first flange portion 62 of the cylindrical portion 61 with the lid mounting bolt B4, so that the lid portion 64 covers the upper opening of the cylindrical portion 61.

[0057] The seal groove 65 is a ring-shaped groove in which the third seal member 70 is disposed. The seal groove 65 is disposed concentrically with the cylindrical portion 61 on the lower surface 60a of the upper housing 60 (the lower surfaces of the cylindrical portion 61 and the second flange portion 63).

[0058] The upper housing 60 is attached to the upper surface 10a of the head plate 10 by fastening the second flange portion 63 to the head plate 10 with housing mounting bolts B3. At this time, the cylindrical portion 61 accommodates the protruding upper portion, and a cylindrical space is formed between the cylindrical portion 61 and the protruding upper portion.

[0059] The third seal member 70 is, for example, an O-ring made of fluororesin. The third seal member 70 is disposed in the seal groove 65 of the upper housing 60. The third seal member 70 provides a liquid-tight seal between the upper surface 10a of the head plate 10 and the lower surface 60a (seal groove 65) of the upper housing 60. The sealing performance of the third seal member 70 is determined by the tightening force of the housing mounting bolts B3. That is, when the housing mounting bolts B3 are loosened, the sealing performance decreases, and when the housing mounting bolts B3 are tightened, the sealing performance improves.

[0060] The shaft fixing member 80 fixes the lift shaft 20 in the lowered position when the lift shaft 20 is in the lowered position. The shaft fixing member 80 includes a receiving member 81 and a fixing member 82.

[0061] The receiving member 81 has a ring-shaped plate shape. The outer diameter of the receiving member 81 is larger than the outer diameter of the first shaft portion 21 and the inner diameter of the collar 7, but smaller than the inner diameter of the cylindrical portion 61 and the outer diameter of the collar 7. The receiving member 81 has an insertion hole 81a.

[0062] The insertion hole 81a is a through-hole that passes through the receiving member 81 in the up-down direction. The insertion hole 81a is located in the center of the receiving member 81. The inner diameter of the insertion hole 81a is smaller than the outer diameter of the first shaft portion 21 and larger than the outer diameter of the male thread portion 23b of the first connecting member 23. The male thread portion 23b is inserted into the insertion hole 81a. The first nut member 25 and the connecting portion 23a of the first connecting member 23 are located above the receiving member 81. The receiving member 81 is attached to the upper end surface 21b of the first shaft portion 21 by tightening the first nut member 25, which is in contact with the upper surface 81b of the receiving member 81.

[0063] The fixing member 82 includes a peripheral wall portion 82a and a flange portion 82b.

[0064] The peripheral wall portion 82a is cylindrical. The outer diameter of the peripheral wall portion 82a is smaller than the inner diameter of the cylindrical portion 61. In the radial direction of the peripheral wall portion 82a, the upper end of the peripheral wall portion 82a protrudes outward to form a ring-shaped flange portion 82b. That is, the peripheral wall portion 82a and the flange portion 82b are integrally formed. The peripheral wall portion 82a is inserted into the cylindrical portion 61. When the fixing member 82 is not fastened to the upper housing 60 by the pressing bolt B5, the length of the portion of the peripheral wall portion 82a below the flange portion 82b in the vertical direction is longer than the length between the upper end surface 60b of the upper housing 60 and the upper surface 81b of the receiving member 81. Therefore, the flange portion 82b does not abut against the upper end surface 60b of the upper housing 60.

[0065] The flange portion 82b is fastened to the upper housing 60 by the pressing bolts B5, thereby fastening the fixing member 82 to the upper housing 60. At this time, the flange portion 82b is pressed downward (toward the head plate 10 and lift shaft 20) by the pressing bolts B5. The lower end of the peripheral wall portion 82a is in contact with the upper surface 81b of the receiving member 81. As a result, the receiving member 81 and the fixing member 82 (i.e., the shaft fixing member 80) press the lift shaft 20 toward the head plate 10, fixing it in the lowered position. In this way, when the lift shaft 20 is in the lowered position, the shaft fixing member 80 presses the lift shaft 20 toward the head plate 10, fixing it in the lowered position.

[0066] The sealing member 3 configured in this manner is attached to the upper open end 2a of the pump column 2 by fastening the head plate 10 to the upper open end 2a with plate mounting bolts B1. At this time, a gasket (not shown) is placed between the upper open end 2a and the head plate 10, creating a liquid-tight seal between the head plate 10 and the upper open end 2a.

[0067] ●Sealing structure using sealing material (1) Next, the sealing structure using the sealing member 3 will be described with reference to FIGS. 1 to 3. The sealing member 3 seals the liquefied gas Lg in the pump column 2 and the vaporized liquefied gas Lg (hereinafter referred to as "vaporized gas Vg"). 」 (See Figure 4. Same below.) )and The lift shaft 20 has a sealing structure that prevents the liquefied gas Lg and the vaporized gas Vg from leaking out of the sealing member 3. The sealing structure is made up of the fitting portion 13, the bellows member 30, the first seal member 40, and the second seal member 50. The sealing structure can prevent the liquefied gas Lg and the vaporized gas Vg from leaking out of the sealing member 3 whether the lift shaft 20 is in the lowered position or the raised position.

[0068] Hereinafter, the sealing structure for each position of the lift shaft 20 will be described in relation to the operation of the sealing member 3 (mainly the lift shaft 20).

[0069] While the pump 5 is operating, the liquefied gas Lg discharged from the pump 5 rises inside the pump column 2 and is supplied to the outside of the storage tank T through the liquid supply line R1. The pump column 2 is filled with the liquefied gas Lg, and a discharge pressure (for example, a maximum of 2 MPa) from the pump 5 is applied to the head plate 10, the lift shaft 20, and the bellows member 30. At this time, the lift shaft 20 is pressed downward by the shaft fixing member 80. As a result, the lift shaft 20 is fixed in a lowered position.

[0070] When the lift shaft 20 is in the lowered position, the bellows tubular body 31 is extended downward in accordance with the position of the lower end surface 22b of the second shaft portion 22. At this time, an appropriate tension is applied to the bellows tubular body 31. Therefore, the bellows tubular body 31 can withstand the discharge pressure and is not excessively deformed. Furthermore, as described above, the bellows member 30 is constructed as a single unit, and therefore the bellows member 30 does not have any gaps that would allow leakage of the liquefied gas Lg due to the discharge pressure. Therefore, leakage of the liquefied gas Lg from the bellows member 30 to the bellows internal space S is prevented.

[0071] When the lift shaft 20 is in the lowered position, the liquefied gas Lg is blocked by the bellows member 30 and the first seal member 40 and does not leak into the bellows space S. Furthermore, because the second mounting member 33 is liquid-tightly fitted into the fitting portion 13, the liquefied gas Lg does not leak between the second mounting member 33 and the fitting portion 13 into the insertion hole 11. Furthermore, even if a small amount of liquefied gas Lg leaks into the insertion hole 11 from between the second mounting member 33 and the fitting portion 13 due to discharge pressure, the liquefied gas Lg is blocked by the second seal member 50 and does not leak into the upper housing 60.

[0072] When the lift shaft 20 is in the lowered position, the lower end surface 21c of the first shaft portion 21 abuts against the second seal member 50, thereby restricting the movement of the lift shaft 20 downward from the lowered position. At this time, the first shaft portion 21 functions as a descent restricting member in the present invention. As a result, the bellows tubular body 31 is not excessively stretched, and technical problems such as damage to the bellows member 30 (the bellows tubular body 31 or the welded portions) do not occur.

[0073] Next, while the pump 5 is not operating, liquefied gas Lg remains in the pump column 2 up to the same height as the liquid level of the liquefied gas Lg in the storage tank T. In addition, the space above the liquid level in the pump column 2 is filled with vaporized gas Vg. At this time, the discharge pressure from the pump 5 is not applied to the head plate 10, the lift shaft 20, and the bellows member 30. Even in this state, the vaporized gas Vg does not leak into the bellows space S and the insertion hole 11 due to the sealing structure described above.

[0074] The pump 5 is periodically (for example, every few years) removed from the pump column 2 for maintenance. Removing the pump 5 requires closing the foot valve 6 and removing the residual gas (liquefied gas Lg and vaporized gas Vg) from the pump column 2. As a preparation for this, the lift shaft 20 is raised from the lowered position to the raised position, thereby lifting the pump 5 to a predetermined height within the pump column 2.

[0075] In preparation for lifting the lift shaft 20, the cover portion 64 and the fixing member 82 are removed. As a result, the pressure applied by the pressure bolt B5 is released, and the sealing performance of the second seal member 50 is reduced. At this time, the bellows space S and the insertion hole 11 are still liquid-tightly sealed by the fitting portion 13, the bellows member 30, and the first seal member 40. Therefore, residual gas does not leak from the bellows space S and the insertion hole 11 into the space within the cylindrical portion 61. In this embodiment, the handled liquid is liquefied ammonia, and the vaporized gas Vg is ammonia gas, which is flammable and highly toxic to living organisms. Furthermore, ammonia gas is lighter than air and therefore easily inhaled by maintenance workers. The sealing member 3 according to the present invention has a sealing structure using the bellows member 30, making it applicable to handled liquids that are difficult to handle, such as liquefied ammonia.

[0076] Next, a cable (not shown) from a lift (not shown) is connected to the first connecting member 23 of the lift shaft 20, and the lift shaft 20 is raised to the raised position by the lift. At this time, the pump 5 is lifted up onto the lift shaft 20 via the support cable 4, and the foot valve 6 is closed by the biasing force of a spring (not shown).

[0077] FIG. 4 is a schematic cross-sectional view of the sealing member 3 when the lift shaft 20 is in the raised position.

[0078] When the lift shaft 20 is raised to the raised position, the sealing by the second seal member 50 is released, and the bellows internal space S communicates with the space inside the cylindrical portion 61 through the insertion hole 11. At this time, the bellows cylindrical body 31 is contracted upward following the movement of the lift shaft 20. Therefore, the sealing state of the bellows internal space S and the insertion hole 11 by the fitting portion 13, the bellows member 30, and the first seal member 40 is maintained. Therefore, residual gas does not leak from the bellows internal space S and the insertion hole 11 to the space inside the cylindrical portion 61 and to the outside of the sealing member 3.

[0079] The lift shaft 20 riseWhen the receiving member 81 is in the raised position, the collar 7 can be attached between the receiving member 81 and the first flange portion 62 of the upper housing 60. When the collar 7 is attached between the receiving member 81 and the first flange portion 62, the lift shaft 20 is fixed in the raised position. At this time, the sealing member 3 supports the pump 5 by suspending it.

[0080] When the lift shaft 20 is raised above the raised position, the bellows cylindrical body 31 is contracted upward to its limit, thereby restricting the movement of the lift shaft 20 above the raised position. At this time, the bellows member 30 can function as the lift restriction member of the present invention.

[0081] Next, an inert gas is introduced into the pump column 2, and the remaining gas in the pump column 2 is returned to the storage tank T. The subsequent removal process of the pump 5 is a known process, and therefore a description thereof will be omitted.

[0082] Summary (1) According to the embodiment described above, the sealing member 3 includes a head plate 10, a lift shaft 20, and a bellows member 30. The head plate 10 has an insertion hole 11 extending in the vertical direction, and is attached to the upper open end 2a of the pump column 2 so as to close the upper open end 2a. The lift shaft 20 is disposed so as to pass through the insertion hole 11, and is raised and lowered between a raised position and a lowered position when the pump 5 is raised and lowered. The bellows member 30 expands and contracts in the axial direction (vertical direction) of the lift shaft 20 in response to the raising and lowering of the lift shaft 20. The bellows member 30 includes a bellows cylindrical body 31, a first mounting member 32, and a second mounting member 33. The bellows cylindrical body 31 covers the outer peripheral surface of the protruding lower portion of the lift shaft 20. The first mounting member 32 is disposed contiguous with the lower end 31a of the bellows cylindrical body 31, and is attached to the second axial portion 22. (Protruding lower part) Lower end surface 22 bThe second mounting member 33 is disposed contiguous with the upper end 31b of the bellows cylindrical body 31, and is attached to the underside 10b of the head plate 10. With this configuration, the bellows internal space S is surrounded by the bellows member 30. Therefore, even when the lift shaft 20 moves up and down, the bellows cylindrical body 31 expands and contracts in response to the movement of the lift shaft 20, and the bellows internal space S is sealed by the bellows member 30. In this way, in the sealing member 3, the bellows member 30 prevents leakage of the liquefied gas Lg and residual gas when the pump 5 moves up and down.

[0083] Furthermore, according to the embodiment described above, the insertion hole 11 includes the fitting portion 13 into which the second mounting member 33 is fitted in a liquid-tight manner. With this configuration, the gap between the second mounting member 33 and the fitting portion 13 (the lower surface 10b of the head plate 10) is liquid-tight sealed. As a result, the bellows internal space S and the insertion hole 11 are liquid-tight sealed by the fitting portion 13 and the bellows member 30. Therefore, in the sealing member 3, the fitting portion 13 and the bellows member 30 prevent leakage of the liquefied gas Lg and residual gas when the pump 5 is raised and lowered.

[0084] Furthermore, according to the embodiment described above, the sealing member 3 includes the first seal member 40 disposed between the first mounting member 32 and the lift shaft 20. With this configuration, the bellows space S is liquid-tightly sealed by the bellows member 30 and the first seal member 40. Therefore, in the sealing member 3, the bellows member 30 and the first seal member 40 prevent leakage of the liquefied gas Lg and residual gas when the pump 5 is raised and lowered.

[0085] Furthermore, according to the embodiment described above, the lift shaft 20 includes the first shaft portion 21 and the second shaft portion 22. The second shaft portion 22 has an outer diameter smaller than that of the first shaft portion 21, is positioned below the first shaft portion 21, and is inserted through the second hole portion 11b. The second seal member 50 is disposed between the lower end surface 21c of the first shaft portion 21 and the bottom surface 11d (head plate 10) of the first hole portion 11a. With this configuration, the first shaft portion 21 cannot be inserted through the second hole portion 11b, and movement of the lift shaft 20 below the lowered position is restricted. In other words, the first shaft portion 21 functions as a descent restricting member in the present invention. When the lift shaft 20 is lowered to the lowered position, the operator cannot visually check the state of the bellows member 30. Therefore, if the descent of the lift shaft 20 is not restricted, the bellows tubular body 31 may be excessively stretched, resulting in technical problems such as damage to the bellows member 30. In contrast, with this configuration, the bellows cylindrical body 31 is not excessively stretched, and no technical problems such as damage to the bellows member 30 occur. Furthermore, when the lift shaft 20 is in the lowered position, the gap between the lower end surface 21c of the first shaft portion 21 and the bottom surface 11d of the first hole portion 11a is sealed by the second seal member 50.

[0086] Furthermore, according to the embodiment described above, the sealing member 3 includes a shaft fixing member 80 that fixes the lift shaft 20 in a lowered position. The shaft fixing member 80 presses the lift shaft 20 toward the head plate 10 with a pressure bolt B5. With this configuration, even if discharge pressure is applied to the lift shaft 20, the lift shaft 20 is fixed in the lowered position. Furthermore, since the second seal member 50 is pressed between the lower end surface 21c of the first shaft portion 21 and the bottom surface 11d of the first hole portion 11a, the sealing performance of the second seal member 50 is improved.

[0087] Furthermore, according to the embodiment described above, the sealing member 3 includes the upper housing 60 attached to the upper surface 10a of the head plate 10, and the third seal member 70 disposed between the upper housing 60 and the upper surface 10a. The upper housing 60 houses the protruding upper portion when the lift shaft 20 is in the lowered position. With this configuration, the protruding upper portion is protected from the elements while the pump 5 is in operation. Furthermore, even if a small amount of liquefied gas Lg leaks into the upper housing 60, the upper housing 60 and the third seal member 70 prevent the liquefied gas Lg from leaking outside the sealing member 3.

[0088] Furthermore, according to the embodiment described above, the bellows member 30 functions as an ascent restriction member that restricts the movement of the lift shaft 20 above the elevated position. With this configuration, technical problems such as the lift shaft 20 coming off do not occur.

[0089] ●Submerged Pump System (2)● Next, another embodiment of the submerged pump system according to the present invention (hereinafter referred to as the "second embodiment") will be described, focusing on the differences from the first embodiment described above. The second embodiment differs from the first embodiment in that the sealing member is provided with a lower housing and the bellows member is provided with an ascent restriction member. In the following description, elements common to the first embodiment are given the same reference numerals, and Figures 1 to 3 will be referenced as appropriate, with their description omitted.

[0090] ●Configuration of Submerged Pump System (2) FIG. 5 is a schematic cross-sectional view showing a second embodiment of a submerged pump system according to the present invention.

[0091] The submerged pump system 1A is attached to a storage tank T in which liquefied gas Lg is stored, and pumps the liquefied gas Lg from the storage tank T to the outside. The submerged pump system 1A includes a pump column 2, a sealing member 3A, a support cable 4, a pump 5, a foot valve 6, and a collar 7.

[0092] ●Configuration of sealing member (2) Next, a specific configuration of the sealing member 3A (the sealing member according to the present invention) will be described.

[0093] FIG. 6 is a schematic cross-sectional view showing a sealing member 3A in the second embodiment. FIG. 7 is a schematic exploded cross-sectional view of the sealing member 3A. Figure 6 shows the sealing member 3A when a lift shaft 20A (described later) is in the lowered position. For ease of explanation, Figure 6 also shows the upper part of the pump column 2. In the following explanation, bolt holes corresponding to bolts B1 to B6 (described later) are well known, and therefore will not be described here. In the following explanation, Figure 5 will be referenced as appropriate.

[0094] The sealing member 3A includes a head plate 10A, a lift shaft 20A, a bellows member 30A, a first seal member 40, an upper housing 60, a third seal member 70, a shaft fixing member 80, a lower housing 90, a fourth seal member 100, a fifth seal member 110, a plurality of plate mounting bolts B1, a plurality of bellows mounting bolts B2, a plurality of housing mounting bolts B3, a plurality of lid mounting bolts B4, a plurality of pressure bolts B5, and a plurality of housing mounting bolts B6.

[0095] The functions of head plate 10A, lift shaft 20A, and bellows member 30A are the same as those of head plate 10, lift shaft 20, and bellows member 30 in the first embodiment, respectively.

[0096] The head plate 10A has, for example, a disk shape. The head plate 10A is made of, for example, a metal such as stainless steel. The head plate 10A includes an insertion hole 11A and a fitting portion 13.

[0097] The insertion hole 11A is a through-hole that penetrates the head plate 10A in the vertical direction. That is, the insertion hole 11A extends in the vertical direction in the head plate 10A. The insertion hole 11A is disposed in the center of the head plate 10A. The inner diameter of the insertion hole 11A is slightly larger than the outer diameter of the shaft body 27, which will be described later. The insertion hole 11A is an example of a through-hole in the present invention.

[0098] The lift shaft 20A includes a first connecting member 23, a second connecting member 24A, a first nut member 25, a second nut member 26, and a shaft body 27.

[0099] The second connecting member 24A is a member to which the support cable 4 is connected. The second connecting member 24A includes a ring-shaped connecting portion 24a and a male threaded portion 24c extending upward from the connecting portion 24a. The length of the male threaded portion 24c is longer than the length of the male threaded portion 24b in the first embodiment. The second connecting member 24A is attached to the lower end of the shaft body 27 by threading the male threaded portion 24c into a second female threaded hole 27b, which will be described later.

[0100] The shaft 27 is inserted through the insertion hole 11A of the head plate 10A and the cylindrical portion 33a Together with this, it guides the lift shaft 20A in moving up and down. The shaft body 27 has a cylindrical shape that is long in the vertical direction. The shaft body 27 has a first female screw hole 27a and a second female screw hole 27b.

[0101] The first female screw hole 27a extends in the vertical direction and opens to an upper end surface 27c of the shaft body 27. The second female screw hole 27b extends in the vertical direction and opens to a lower end surface 27d of the shaft body 27.

[0102] The lift shaft 20A is inserted from above into the insertion hole 11A of the head plate 10A and is disposed so as to penetrate the insertion hole 11A. The lift shaft 20A can be raised and lowered between a lowered position and an upper position when the pump 5 is raised and lowered. When the lift shaft 20A is in the upper or lowered position, the shaft body 27 protrudes in the vertical direction beyond the head plate 10A.

[0103] The bellows member 30A includes a bellows cylindrical body 31, a second mounting member 33, and a first mounting member .

[0104] The first mounting member 34 mounts the bellows cylinder body 31 to the lift shaft 20A (the protruding lower portion described below). The first mounting member 34 includes a bottom portion 34a, a wall portion 34b, an insertion hole 34c, and a seal groove 34d.

[0105] The bottom portion 34a is shaped like a ring plate. The bottom portion 34a is disposed adjacent to and below the lower end 31a of the bellows tubular body 31. The outer edge of the bottom portion 34a extends upward to form a cylindrical wall portion 34b. That is, the bottom portion 34a and the wall portion 34b are integrally formed. In the vertical direction, the length of the wall portion 34b is longer than the length of the bellows tubular body 31 when fully contracted. The inner diameter of the wall portion 34b is larger than the outer diameter of the bellows tubular body 31. The outer diameter of the wall portion 34b is smaller than the inner diameter of a tubular portion 91, which will be described later.

[0106] The insertion hole 34c is a through-hole that passes through the bottom portion 34a in the vertical direction. The insertion hole 34c is disposed in the center of the bottom portion 34a. The inner diameter of the insertion hole 34c is larger than the outer diameter of the male thread portion 24b of the second connecting member 24A and smaller than the outer diameter of the shaft body 27.

[0107] The seal groove 34d is a ring-shaped groove in which the first seal member 40 is disposed. The seal groove 34d is disposed concentrically with the insertion hole 34c on the upper surface 34e of the bottom portion 34a.

[0108] The lower end 31a of the bellows cylindrical body 31 is in contact with the upper surface of the bottom portion 34a of the first mounting member 34 over the entire circumferential direction of the bellows cylindrical body 31. 34 The upper end 31b of the bellows tubular body 31 is liquid-tight welded to the lower surface 33c of the second mounting member 33 around the entire circumferential circumference of the bellows tubular body 31. As a result, the bellows tubular body 31, the second mounting member 33, and the first mounting member 34 are integrally formed. In the radial direction of the bottom portion 34a, the seal groove 34d is positioned inward from the lower end 31a of the bellows tubular body 31. The wall portion 34b also covers the outer peripheral surface of the lower part of the bellows tubular body 31.

[0109] The bellows tubular body 31 is attached to the underside 10b of the head plate 10A by fitting the second mounting member 33 liquid-tightly into the fitting portion 13. The second mounting member 33 is pressed toward the head plate 10A by the bellows mounting bolt B2. The bellows tubular body 31 accommodates the protruding lower portion of the lift shaft 20A and covers its outer circumferential surface. The protruding lower portion is the lower half of the shaft body 27, and its length is 1 / 10th that of the lift shaft 20A. A The height changes in response to the elevation of the bellows. A bellows internal space S is formed between the bellows cylindrical body 31 and the lift shaft 20A (shaft body 27).

[0110] The second connecting member 24 is inserted into the insertion hole 34c. A The male threaded portion 24c of the second nut member 26 and the second connecting member 24 are inserted below the bottom portion 34a. A When the second nut member 26, which is in contact with the lower surface 34f of the bottom portion 34a, is tightened, the first mounting member 34 is pressed upward (toward the shaft body 27) and attached to the lower end surface 27d of the shaft body 27 (the protruding lower portion).

[0111] The first seal member 40 is disposed in the seal groove 34d of the first mounting member 34.

[0112] The lower housing 90 covers the outer peripheral surface of the bellows cylindrical body 31 and the outer peripheral surface (the outer peripheral surfaces of the bottom portion 34a and the wall portion 34b) of the first mounting member 34. The lower housing 90 includes a cylindrical portion 91, an inner flange portion 92, an outer flange portion 93, a first seal groove 94, and a second seal groove 95.

[0113] The cylindrical portion 91 has a cylindrical shape. The inner diameter of the cylindrical portion 91 is larger than the outer diameter of the bellows cylindrical body 31 and the outer diameter of the wall portion 34b. In the radial direction of the cylindrical portion 91, the lower end of the cylindrical portion 91 protrudes inward to form a ring-shaped inner flange portion 92. The upper end of the cylindrical portion 91 protrudes outward to form a ring-shaped outer flange portion 93. In other words, the cylindrical portion 91, the inner flange portion 92, and the outer flange portion 93 are integrally formed.

[0114] The first seal groove 94 is a ring-shaped groove in which the fourth seal member 100 is disposed. The first seal groove 94 is disposed on the upper surface 92a of the inner flange portion 92 concentrically with the cylindrical portion 91.

[0115] The second seal groove 95 is a ring-shaped groove in which the fifth seal member 110 is disposed. The second seal groove 95 is disposed on the upper surface 93a of the outer flange portion 93 concentrically with the cylindrical portion 91.

[0116] The lower housing 90 is attached to the lower surface 33c of the second mounting member 33 by fastening the outer flange portion 93 to the second mounting member 33 and the head plate 10A with housing mounting bolts B6. At this time, the tubular portion 91 covers the outer peripheral surfaces of the bellows tubular body 31 and the first mounting member 34. A cylindrical space SA is formed between the bellows tubular body 31 and the tubular portion 91. The upper surface 92a of the inner flange portion 92 faces the lower surface 34f of the first mounting member 34.

[0117] The fourth seal member 100 is, for example, an O-ring made of fluororesin. The fourth seal member 100 is disposed in the first seal groove 94 of the lower housing 90. That is, the fourth seal member 100 is disposed between the lower surface 34f of the bottom portion 34a of the first mounting member 34 and the upper surface 92a of the inner flange portion 92. When the lift shaft 20A is in the lowered position, the fourth seal member 100 abuts against the lower surface 34f and the upper surface 92a, providing a liquid-tight seal therebetween. The sealing performance of the fourth seal member 100 is determined by the tightening force of the pressure bolt B5. That is, when the pressure bolt B5 is loosened, the sealing performance decreases, and when the pressure bolt B5 is tightened, the sealing performance improves. The fourth seal member 100 is an example of a lower seal member defined in the present invention.

[0118] The fifth seal member 110 is, for example, an O-ring made of fluororesin. The fifth seal member 110 is disposed in the second seal groove 95 of the lower housing 90. That is, the fifth seal member 110 is disposed between the lower surface 33c of the second mounting member 33 and the upper surface 93a of the outer flange portion 93, and provides a liquid-tight seal between them. The sealing performance of the fifth seal member 110 is determined by the tightening force of the housing mounting bolt B6. That is, when the housing mounting bolt B6 is loosened, the sealing performance decreases, and when the housing mounting bolt B6 is tightened, the sealing performance improves. The fifth seal member 110 is an example of an upper seal member according to the present invention.

[0119] ●Sealing structure using sealing material (2) Next, the sealing structure of the sealing member 3A will be described with reference to Figures 5 to 7. The sealing member 3A has a sealing structure that prevents the liquefied gas Lg and the vaporized gas Vg (see Figures 4 and 8; the same applies below) in the pump column 2 from leaking out of the sealing member 3A. The sealing structure is made up of the fitting portion 13, the bellows member 30A, the first seal member 40, the lower housing 90, the fourth seal member 100, and the fifth seal member 110. The sealing structure can prevent the liquefied gas Lg and the vaporized gas Vg from leaking out of the sealing member 3A whether the lift shaft 20A is in the lowered position or the raised position.

[0120] Hereinafter, the sealing structure for each position of the lift shaft 20A will be described in relation to the operation of the sealing member 3A (mainly the lift shaft 20A).

[0121] During operation of the pump 5, the discharge pressure from the pump 5 is applied to the head plate 10A, the lift shaft 20A, the second mounting member 33, the first mounting member 34, and the lower housing 90. At this time, the lift shaft 20A is pressed downward by the shaft fixing member 80. As a result, the lift shaft 20A is fixed in the lowered position.

[0122] When lift shaft 20A is in the lowered position, lower surface 34f of bottom portion 34a abuts against fourth seal member 100, thereby liquid-tightly sealing the gap between lower surface 34f and upper surface 92a of inner flange portion 92. Therefore, the space inside cylindrical portion 91 is liquid-tightly sealed by fourth seal member 100 and fifth seal member 110. As a result, the discharge pressure is blocked by lower housing 90 and is not transmitted to bellows cylindrical body 31. Furthermore, bellows internal space S is doubly sealed by lower housing 90 and bellows member 30A.

[0123] When the lift shaft 20A is in the lowered position, the liquefied gas Lg does not leak into the bellows space S and the insertion hole 11A, as in the first embodiment. Even if a small amount of liquefied gas Lg leaks into the insertion hole 11A from between the second mounting member 33 and the fitting portion 13 due to the discharge pressure, the liquefied gas Lg is blocked by the third seal member 70 and does not leak outside the upper housing 60.

[0124] When the lift shaft 20A is in the lowered position, the lower surface 34f of the bottom portion 34a abuts against the fourth seal member 100, thereby restricting the lift shaft 20A from moving downward beyond the lowered position. At this time, the inner flange portion 92 functions as a descent restricting member in the present invention. As a result, the bellows tubular body 31 is not excessively stretched, and technical problems such as damage to the bellows member 30A do not occur.

[0125] Next, while the pump 5 is not operating, the discharge pressure from the pump 5 is not applied to the head plate 10A, the lift shaft 20A, the second mounting member 33, the first mounting member 34, and the lower housing 90. Even in this state, the above-described sealing structure prevents the vaporized gas Vg from leaking into the bellows space S and the insertion hole 11A.

[0126] In preparation for lifting the lift shaft 20A, the cover 64 and the fixing member 82 are removed. As a result, the pressure applied by the pressure bolt B5 is released, and the sealing performance of the fourth seal member 100 is reduced. At this time, residual gas may leak into the space within the cylindrical portion 91. However, the bellows space S and the insertion hole 11 A is still liquid-tightly sealed by the fitting portion 13, the bellows member 30A, and the first seal member 40. Therefore, the residual gas does not leak from the bellows space S and the insertion hole 11A into the space inside the cylindrical portion 61. Because the sealing member 3A according to the present invention has a sealing structure using the bellows member 30A, it is applicable to handling liquids that are difficult to handle, such as liquefied ammonia.

[0127] FIG. 8 is a schematic cross-sectional view of the sealing member 3A when the lift shaft 20A is in the raised position.

[0128] When the lift shaft 20A is raised to the raised position, the sealing by the fourth seal member 100 is released, and the residual gas enters the space within the cylindrical portion 91. At this time, the bellows cylindrical body 31 is contracted upward following the movement of the lift shaft 20A. Therefore, the sealing state of the bellows internal space S and the insertion hole 11A by the bellows member 30A and the first seal member 40 is maintained. Therefore, the residual gas does not leak from the bellows internal space S and the insertion hole 11A to the space within the cylindrical portion 61 or to the outside of the sealing member 3A.

[0129] When the lift shaft 20A is raised to the raised position, the wall portion 34b of the first mounting member 34 abuts against the lower surface 33c of the second mounting member 33, thereby restricting the lift shaft 20A from moving upward beyond the raised position. At this time, the wall portion 34b functions as an elevation restricting member in the present invention. As a result, the bellows tubular body 31 is not excessively contracted, and technical problems such as damage to the bellows member 30A or the lift shaft 20A coming loose do not occur.

[0130] When the lift shaft 20A is in the raised position, the connecting portion 24a of the second connecting member 24A is located vertically below the inner flange portion 92. Therefore, the support cable 4 connected to the connecting portion 24a does not interfere with the lower housing 90.

[0131] Summary (2) According to the embodiment described above, the sealing member 3A includes a head plate 10A, a lift shaft 20A, and a bellows member 30A. The head plate 10A has an insertion hole 11A extending in the vertical direction and is attached to the upper open end 2a of the pump column 2 so as to close the upper open end 2a. The lift shaft 20A is disposed to pass through the insertion hole 11A and is raised and lowered between a raised position and a lowered position when the pump 5 is raised and lowered. The bellows member 30A expands and contracts in the axial direction (vertical direction) of the lift shaft 20A in response to the raising and lowering of the lift shaft 20A. The bellows member 30A includes a bellows cylindrical body 31, a first mounting member 34, and a second mounting member 33. The bellows cylindrical body 31 covers the outer peripheral surface of the protruding lower portion of the lift shaft 20A. The first mounting member 34 is disposed contiguous with the lower end 31a of the bellows cylindrical body 31 and is attached to the shaft 27. (Protruding lower part) Bottom surface 27 dThe second mounting member 33 is disposed contiguous with the upper end 31b of the bellows tubular body 31 and is attached to the underside 10b of the head plate 10A. With this configuration, the bellows internal space S is surrounded by the bellows member 30A. Therefore, even when the lift shaft 20A moves up and down, the bellows tubular body 31 expands and contracts in response to the movement of the lift shaft 20A, and the bellows internal space S is sealed by the bellows member 30A. In this way, with the sealing member 3A, the bellows member 30A prevents leakage of the liquefied gas Lg and residual gas when the pump 5 moves up and down.

[0132] Furthermore, according to the embodiment described above, insertion hole 11A includes fitting portion 13 into which second mounting member 33 is fitted in a liquid-tight manner. With this configuration, the gap between second mounting member 33 and fitting portion 13 (lower surface 10b of head plate 10A) is liquid-tight sealed. As a result, bellows internal space S and insertion hole 11A are liquid-tight sealed by fitting portion 13 and bellows member 30A. Therefore, in sealing member 3A, bellows member 30A prevents leakage of liquefied gas Lg and residual gas when pump 5 is raised and lowered.

[0133] Furthermore, according to the embodiment described above, sealing member 3A includes first seal member 40 disposed between first mounting member 34 and lift shaft 20A. With this configuration, bellows space S is liquid-tightly sealed by bellows member 30A and first seal member 40. Therefore, in sealing member 3A, bellows member 30A and first seal member 40 prevent leakage of liquefied gas Lg and residual gas when pump 5 is raised and lowered.

[0134] Furthermore, the above-described EmbodimentAccording to the present invention, the sealing member 3A includes a lower housing 90. The lower housing 90 includes a cylindrical portion 91 that covers the outer peripheral surface of the bellows cylindrical body 31 and an inner flange portion 92 that faces the lower surface 34f of the first mounting member 34. This configuration restricts downward movement of the lift shaft 20A below the lowered position. That is, the inner flange portion 92 functions as a descent restricting member in the present invention. As a result, the bellows cylindrical body 31 is not excessively stretched, and technical problems such as damage to the bellows member 30A do not occur. Furthermore, this configuration allows the bellows cylindrical body 31 to be covered by the lower housing 90. Therefore, the bellows cylindrical body 31 is not exposed to the flow of the liquefied gas Lg, and the effects of the discharge pressure are suppressed.

[0135] Furthermore, the above-described Embodiment According to the seal member 3A, the seal member 3A includes a fourth seal member 100 and a fifth seal member 110. A is in the lowered position, the fourth seal member 100 is disposed between the lower surface 34f and the upper surface 92a of the inner flange portion 92 and abuts against them. The fifth seal member 110 is disposed between the second mounting member 33 and the lower housing 90. With this configuration, the space within the cylindrical portion 91 is liquid-tightly sealed by the fourth seal member 100 and the fifth seal member 110. As a result, the discharge pressure is blocked by the lower housing 90, the fourth seal member 100, and the fifth seal member 110 and is not transmitted to the bellows cylindrical body 31. Furthermore, the bellows internal space S is doubly sealed by the lower housing 90 and the bellows member 30A.

[0136] Furthermore, according to the embodiment described above, the sealing member 3A includes the shaft fixing member 80 that fixes the lift shaft 20A in the lowered position. With this configuration, even if discharge pressure is applied to the lift shaft 20A, the lift shaft 20A is fixed in the lowered position. Furthermore, since the fourth seal member 100 is pressed between the lower surface 34f and the upper surface 92a, the sealing performance of the fourth seal member 100 is improved.

[0137] Furthermore, according to the embodiment described above, the first mounting member 34 includes a ring-shaped bottom portion 34a adjacent to the lower end 31a of the bellows tubular body 31, and a wall portion 34b extending upward from the outer edge of the bottom portion 34a. With this configuration, the first mounting member 34 functions as an elevation restricting member that restricts movement of the lift shaft 20A above the elevated position. Therefore, the bellows tubular body 31 does not contract excessively, and technical problems such as damage to the bellows member 30A (the bellows tubular body 31 or welded portions) do not occur. Furthermore, technical problems such as the lift shaft 20A coming loose do not occur.

[0138] Furthermore, according to the embodiment described above, the sealing member 3A includes the upper housing 60 attached to the upper surface 10a of the head plate 10A, and the third seal member 70 disposed between the upper housing 60 and the upper surface 10a. The upper housing 60 houses the protruding upper portion when the lift shaft 20A is in the lowered position. With this configuration, the protruding upper portion is protected from exposure to wind and rain while the pump 5 is in operation. Furthermore, even if a small amount of liquefied gas Lg leaks into the upper housing 60, the upper housing 60 and the third seal member 70 prevent the liquefied gas Lg from leaking outside the sealing member 3A.

[0139] ●Other embodiments● In the first embodiment described above, the insertion hole 11 does not necessarily have to include the first hole portion 11a. In this case, for example, the seal groove 12 into which the second seal member 50 is fitted may be disposed on the upper surface 10a of the head plate 10.

[0140] In each of the above-described embodiments, the insertion holes 11, 11A and the tubular portion 33a may have ventilation grooves that bypass the bellows internal space S and the space inside the tubular portion 61. This configuration facilitates the flow of air into the bellows internal space S and the flow of air out of the bellows internal space S. As a result, the bellows tubular body 31 can easily expand and contract.

[0141] Furthermore, in the first embodiment described above, the seal groove 12 may be disposed in the lower end surface 21c of the first shaft portion 21.

[0142] Furthermore, in the present invention, the lift shafts 20, 20A may be fixed by the collars 7 not at the raised position but at a holding position that is lower than the raised position. In this case, the lift shafts 20, 20A are raised to the raised position, and after the collars 7 are placed, they are lowered to the holding position. This configuration makes it easier to place the collars 7.

[0143] Furthermore, in the second embodiment described above, the shaft body 27 includes the first shaft portion 21 and the second shaft portion 22 In this case, for example, the first shaft portion 21 may constitute a part of the protruding lower portion, and the first mounting member 34 may be attached to the lower end surface 21c of the first shaft portion 21. In this case, for example, the sealing member 3A may include a cylindrical collar member that covers the outer peripheral surface of the second shaft portion 22 and is disposed between the first mounting member 34 and the second nut member 26, and the first mounting member 34 may be attached to the lower end surface 21c of the first shaft portion 21 via the collar member. 34 may be pressed upward.

[0144] Furthermore, in the first embodiment described above, the bellows member 30 may include a first mounting member 34 instead of the first mounting member 32. In this configuration, the bellows tubular body 31 does not contract excessively, and technical problems such as damage to the bellows member 30 (the bellows tubular body 31 or the welded portion) do not occur. Furthermore, technical problems such as the lift shaft 20 coming loose do not occur.

[0145] Furthermore, in the second embodiment described above, the bellows member 30A may include the first attachment member 32 instead of the first attachment member .

[0146] Furthermore, in each of the embodiments described above, the bellows tubular body 31 may be molded integrally with the first mounting members 32, 34 and / or the second mounting member 33. This configuration improves the strength of the bellows members 30, 30A.

[0147] Furthermore, in each of the above-described embodiments, the configuration for attaching the first mounting members 32, 34 to the lift shafts 20, 20A is not limited to the present embodiment. That is, for example, the first mounting members 32, 34 may be liquid-tightly attached to the lift shafts 20, 20A by welding. Also, for example, the first mounting member 32 may be liquid-tightly welded to the outer peripheral surface of the second shaft portion 22, and the first mounting member 34 may be liquid-tightly welded to the outer peripheral surface of the shaft body 27. In this case, the second nut member 26 is not necessary.

[0148] Furthermore, in each of the embodiments described above, the seal groove 32b may be arranged in the lower end surface 22b of the second shaft portion 22, and the seal groove 34d may be arranged in the lower end surface 27d of the shaft body 27.

[0149] Furthermore, in each of the embodiments described above, the configuration for sealing the gap between the second mounting member 33 and the head plate 10, 10A is not limited to this embodiment. That is, for example, the second mounting member 33 may be liquid-tightly attached to the head plate 10, 10A by welding. Also, for example, the second mounting member 33 may be disposed in the fitting portion 13 and attached to the head plate 10, 10A by a bellows mounting bolt B2. In this case, a seal member is disposed between the lower surface 10b (fitting portion 13) of the head plate 10, 10A and the second mounting member 33.

[0150] Furthermore, in each of the embodiments described above, the second mounting member 33 may be shaped like a ring plate. In this case, for example, the second hole portion 11b or the insertion hole 11A may have the same function as the cylindrical portion 33a.

[0151] Furthermore, in the second embodiment described above, the shape of the wall portion 34b is not limited to a cylindrical shape. That is, for example, the wall portion 34b may be formed of a plurality of arc-shaped plate-shaped (or plate-shaped, rod-shaped, etc.) members arranged at a distance from each other.

[0152] Furthermore, in the second embodiment described above, the bottom portion 34a may be provided with a plurality of through-holes that pass through the bottom portion 34a in the up-down direction between the lower end 31a of the bellows cylindrical body 31 and the wall portion 34b.

[0153] Figure 9(a) is a schematic plan view showing a first modified example of the first mounting member 34 in the second embodiment, and (b) is a schematic plan view showing a second modified example of the first mounting member 34 in the second embodiment.

[0154] The figure shows the first mounting member 34 as viewed from above. For ease of explanation, the figure also shows the lift shaft 20A and the lower end portion 31a of the bellows tubular body 31 by dashed lines. As shown in FIG. 9(a), the first mounting member 34 in the first modified example has a wall portion 34b made up of four arc-shaped plate-shaped members. In the circumferential direction of the bottom portion 34a, the members making up the wall portion 34b are arranged at equal intervals on the outer edge of the bottom portion 34a. .child In this configuration, when the lift shaft 20A is lifted, the liquefied gas Lg in the space surrounded by the wall portion 34b is removed downward through the gaps between the members.

[0155] 9(b), the first mounting member 34 in the second modified example is disposed on the bottom portion 34a and has four through-holes 34g that penetrate the bottom portion 34a in the vertical direction. The through-holes 34g are disposed at equal intervals in the circumferential direction of the bottom portion 34a between the lower end 31a of the bellows cylindrical body 31 and the wall portion 34b. In this configuration, when the lift shaft 20A is lifted, the liquefied gas Lg in the space surrounded by the wall portion 34b is removed downward through the through-holes 34g. The number of arc-shaped plate-shaped members and through-holes 34g is not limited to four.

[0156] Furthermore, in each of the embodiments described above, a sealing member such as a gasket may be disposed between the second mounting member 33 and the head plate 10, 10A. This configuration improves the sealing performance between the second mounting member 33 and the head plate 10, 10A.

[0157] Furthermore, in each of the above-described embodiments, the materials of the bellows members 30, 30A and the first to fifth seal members 40, 50, 70, 100, 110 may be selected appropriately depending on the pumped fluid, and are not limited to the present embodiment.

[0158] Furthermore, in each of the above-described embodiments, the first to fifth seal members 40, 50, 70, 100, and 110 are not limited to O-rings. That is, for example, the first to fifth seal members 40, 50, 70, 100, and 110 may be ring-shaped gaskets. In this case, the seal grooves 12, 32b, 34d, 65, 94, and 95 are unnecessary.

[0159] Furthermore, in each of the embodiments described above, a female thread portion may be formed on the upper part of the inner peripheral surface of the cylindrical portion 61 of the upper housing 60, and a male thread portion corresponding to the female thread portion may be formed on the outer peripheral surface of the peripheral wall portion 82a of the shaft fixing member 80. According to this configuration, by threading the shaft fixing member 80 into the cylindrical portion 61, the shaft fixing member 80 can press the lift shafts 20, 20A downward.

[0160] Furthermore, in the first embodiment described above, the sealing member 3 does not have to include the second seal member 50. In this configuration, although the sealing performance within the insertion hole 11 is reduced, leakage of the liquefied gas Lg into the bellows space S and the insertion hole 11 is prevented by the fitting portion 13, the bellows member 30, and the first seal member 40. Therefore, the liquefied gas Lg does not leak to the outside of the sealing member 3. Also, in this configuration, the first shaft portion 21 functions as a descent restricting member.

[0161] Furthermore, in each of the above-described embodiments, the sealing members 3, 3A may not be provided with an ascent restriction member and / or a descent restriction member, in which case, for example, the height of the ascent position and / or the descent position may be set in advance.

[0162] Furthermore, in each of the embodiments described above, the configuration of the descent restricting member is not limited to the first shaft portion 21 or the inner flange portion 92. That is, for example, the descent restricting member may be configured with a knock pin or a bolt that is fitted into the protruding upper portion. Also, for example, the descent (ascent) restricting member may be configured with a slide rail with a stopper that is arranged between the first mounting member 32, 34 and the second mounting member 33.

[0163] Furthermore, in each of the embodiments described above, the receiving member 81 may be molded integrally with the fixing member 82.

[0164] Furthermore, in each of the embodiments described above, when the flange portion 82b is fastened to the upper housing 60 by the pressing bolt B5, the flange portion 82b may or may not abut against the upper end surface 60b of the upper housing 60. In the former case, the force (pressing force) with which the fixing member 82 presses the receiving member 81 is uniform in the circumferential direction of the fixing member 82. Furthermore, even if the fixing member 82 is attached and detached multiple times, the pressing force is approximately the same each time the fixing member 82 is attached and detached. On the other hand, in the latter case, the pressing force can be adjusted according to the state of the second seal member 50 or the fourth seal member 100, for example.

[0165] Furthermore, in each of the embodiments described above, the lower housing 90 may be attached to the lower surface 10b of the head plate 10, 10A. In this case, the fifth seal member 110 is disposed between the lower surface 10b and the upper surface 93a of the outer flange portion 93.

[0166] Furthermore, in each of the embodiments described above, the sealing members 3, 3A do not necessarily have to include the bellows mounting bolts B2.

[0167] Furthermore, in each of the embodiments described above, the sealing member 3, 3A may include a gland seal disposed between the lift shaft 20, 20A and the upper housing 60 (cylindrical portion 61).

[0168] ●Embodiments of the present invention● Next, embodiments of the present invention that can be understood from the above-described embodiments will be described below, using the terms and symbols described in the embodiments.

[0169] A first embodiment of the present invention is a sealing member (e.g., sealing member 3, 3A) that seals an open end (e.g., upper open end 2a) of a cylindrical pump column (e.g., pump column 2) in which a pump (e.g., pump 5) immersed in a handled liquid (e.g., liquefied gas Lg) is accommodated, and that suspends and supports the pump when the pump is raised and lowered in the pump column. The sealing member has a through hole (e.g., insertion hole 11, 11A) extending in the vertical direction, and is attached to the open end so as to close the open end. A head plate (e.g., head plate 10, 10A) and a lift shaft (e.g., lift shaft 20, 20A) that is disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered. and a bellows member (e.g., bellows member 30, 30A) that expands and contracts in the axial direction of the lift shaft in response to the raising and lowering of the lift shaft, wherein the bellows member is a sealing member that includes a bellows cylindrical body (e.g., bellows cylindrical body 31) that covers the outer peripheral surface of the protruding lower part of the lift shaft that protrudes downward from the head plate, a first mounting member (e.g., first mounting member 32, 34) that is arranged contiguous with the lower end (e.g., lower end 31a) of the bellows cylindrical body and attached to the protruding lower part (e.g., second shaft portion 22, shaft body 27), and a second mounting member (e.g., second mounting member 33) that is arranged contiguous with the upper end (e.g., upper end 31b) of the bellows cylindrical body and attached to the lower surface (e.g., lower surface 10b) of the head plate. With this configuration, even when the lift shaft moves up and down, the bellows cylindrical body expands and contracts in response to the movement of the lift shaft, and the space inside the bellows can be sealed by the bellows member. As a result, the bellows member can prevent leakage of residual gas when the pump moves up and down. In other words, the sealing performance of the sealing member is improved.

[0170] A second embodiment of the present invention is a sealing member in which, in the first embodiment, the through-hole is provided with a fitting portion (for example, fitting portion 13) into which the second mounting member is fitted. According to this configuration, the space within the bellows and the insertion hole are liquid-tightly sealed by the bellows member.

[0171] A third embodiment of the present invention is a sealing member comprising a bellows seal member (e.g., first seal member 40) disposed between the first mounting member and the protruding lower portion of the lift shaft in the first or second embodiment. According to this configuration, P's The bellows member and the first seal member prevent leakage of liquefied gas and residual gas during lifting and lowering.

[0172] A fourth embodiment of the present invention is any one of the first to third embodiments, further comprising an inner flange portion (e.g., inner flange portion 92) facing a lower surface (e.g., lower surface 34f) of the first mounting member, covering the outer peripheral surface of the bellows tubular body and the outer peripheral surface of the first mounting member, and connecting the lower surface (e.g., lower surface 10b) of the head plate (e.g., head plate 10A) or the lower surface ( For example, the bottom 33c) and has a lower housing (for example, lower housing 90). According to this configuration, the bellows tube body is not excessively stretched, and technical problems such as breakage of the bellows member do not occur. The body , liquefied gas S Not exposed to currents.

[0173] A fifth embodiment of the present invention is a sealing member comprising: a lower sealing member (e.g., fourth sealing member 100) arranged between the lower surface of the first mounting member and the upper surface (e.g., upper surface 92a) of the inner flange portion in the fourth embodiment, and abutting the lower surface of the first mounting member and the upper surface of the inner flange portion when the lift shaft is positioned in the lowered position; and an upper sealing member (e.g., fifth sealing member 110) arranged between the lower surface of the head plate or the lower surface of the second mounting member and the lower housing. According to this configuration, the discharge pressure is not transmitted to the bellows cylindrical body. Furthermore, the space inside the bellows is doubly sealed by the lower housing and the bellows member.

[0174] A sixth embodiment of the present invention is a sealing member (e.g., sealing member 3) in any one of the first to third embodiments, wherein the lift shaft (e.g., lift shaft 20) comprises a first shaft portion (e.g., first shaft portion 21) and a second shaft portion (e.g., second shaft portion 22) having an outer diameter smaller than that of the first shaft portion, positioned below the first shaft portion, and inserted into the through hole, and further comprising a shaft seal member (e.g., second seal member 50) positioned between the head plate and the first shaft portion. With this configuration, the bellows cylindrical body is not stretched excessively, and technical problems such as breakage of the bellows member do not occur.

[0175] A seventh embodiment of the present invention is a sealing member comprising, in the fifth or sixth embodiment, a shaft fixing member (e.g., shaft fixing member 80) that fixes the lift shaft in the lowered position by pressing the lift shaft toward the head plate. With this configuration, even if discharge pressure is applied to the lift shaft, the lift shaft is fixed in the lowered position, and the sealing performance of the second and fourth seal members is improved.

[0176] An eighth embodiment of the present invention is a sealing member (e.g., sealing member 3A) in any of the first to seventh embodiments, which has an ascent restriction member (e.g., wall portion 34b) that restricts movement of the lift shaft upward beyond the elevated position, and the first mounting member (e.g., first mounting member 34) is a sealing member having a ring-shaped bottom portion (e.g., bottom portion 34a) adjacent to the lower end of the bellows cylindrical body and a wall portion (e.g., wall portion 34b) extending upward from the outer edge portion of the bottom portion. According to this configuration, the bellows cylindrical body is not excessively contracted, and technical problems such as damage to the bellows member do not occur, and technical problems such as the lift shaft coming off do not occur.

[0177] A ninth embodiment of the present invention is a submerged pump system comprising a pump immersed in a pumped liquid, a cylindrical pump column accommodating the pump, and a sealing member according to any one of the first to eighth embodiments. According to this configuration, the bellows member can prevent the residual gas from leaking when the pump is raised and lowered. [Explanation of symbols]

[0178] 1 Submerged Pump System 2 Pump column 3 Sealing member 5. Pump 10 Head Plate 10b Bottom side 11 Insertion hole (through hole) 13 Inset part 20 Lift shaft 21 First shaft portion (downward movement restricting member) 22 Second shaft 30 Bellows member 31 Bellows cylinder 31a bottom end 31b top end 32 First mounting member 33 Second mounting member 40 first seal member (bellows seal member) 50 second seal member (shaft seal member) 80 Shaft fixing member Lg liquefied gas (handled liquid) 1A Submerged Pump System 3A Sealing member 10A Head Plate 11A Insertion hole (through hole) 20A Lift Shaft 27 Shaft 30A bellows member 34 First mounting member 34a bottom 34b Wall (rise restriction member) 34f Bottom 90 Lower housing 92 Inner flange portion (downward movement restriction member) 92a Top side 100 fourth seal member (lower seal member) 110 Fifth seal member (upper seal member)

Claims

1. A sealing member that seals an open end of a cylindrical pump column that houses a pump that is immersed in a pumped liquid, and that suspends and supports the pump when the pump is raised and lowered within the pump column, a head plate having a through hole extending in the vertical direction and attached to the opening end so as to close the opening end; a lift shaft disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered; a bellows member that expands and contracts in the axial direction of the lift shaft in response to the lift shaft being raised and lowered; a lower housing covering a portion of the bellows member; and The bellows member is a bellows cylinder covering an outer peripheral surface of a protruding lower portion of the lift shaft that protrudes downward from the head plate; a first mounting member disposed continuously with a lower end of the bellows cylindrical body and attached to the protruding lower portion of the lift shaft; a second mounting member disposed continuously with the upper end of the bellows cylindrical body and attached to the lower surface of the head plate; Equipped with The lower housing includes: an inner flange portion facing the lower surface of the first mounting member; Equipped with covering an outer peripheral surface of the bellows cylindrical body and an outer peripheral surface of the first mounting member; Attached to the lower surface of the head plate or the lower surface of the second attachment member, Sealing member.

2. the head plate includes a fitting portion into which the second mounting member is fitted and which is disposed on the lower surface adjacent to the through hole; The sealing member according to claim 1 .

3. a bellows seal member disposed between the first mounting member and the protruding lower portion of the lift shaft; The sealing member according to claim 1 or 2.

4. a lower seal member disposed between the lower surface of the first mounting member and the upper surface of the inner flange portion, the lower seal member abutting against the lower surface of the first mounting member and the upper surface of the inner flange portion when the lift shaft is in the lowered position; an upper seal member disposed between the lower surface of the head plate or the lower surface of the second mounting member and the lower housing; consisting of The sealing member according to claim 1 .

5. The lift shaft A first shaft portion; a second shaft portion having an outer diameter smaller than an outer diameter of the first shaft portion, disposed below the first shaft portion, and inserted into the through hole; Equipped with a shaft seal member disposed between the head plate and the first shaft portion; The sealing member according to claim 1 .

6. a shaft fixing member that fixes the lift shaft at the lowered position by pressing the lift shaft toward the head plate; The sealing member according to claim 4 or 5.

7. a lift restriction member that restricts the lift shaft from moving upward beyond the lifted position, The first mounting member is a ring-shaped bottom portion adjacent to the lower end of the bellows cylindrical body; a wall portion extending upward from the outer edge of the bottom portion; Equipped with When the lift shaft is raised to the raised position, the wall portion abuts against the lower surface of the head plate, thereby functioning as the lift restriction member. The sealing member according to claim 1 .

8. a pump immersed in the handled liquid; a cylindrical pump column that houses the pump; The sealing member according to any one of claims 1 to 7, consisting of Submerged pump system.

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